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A History Of Castles

Stand on a beach and draw a magic circle around you in the sand, and you have a castle. Visit the Imperial War Museum London and you will see copies of Cold War era publications Protect And Survive, and Domestic Nuclear Shelters . Both books have a logo showing a family within a circle. In the face of nuclear war where little can be done to protect most people, we need as much magical protection as we can get. The circle design on Protect And Survive harks back to the earliest attempts by people to find security.

5000 years ago it seems that life in what is now Britain became more difficult. Geoffrey Wainwright in his book The Henge Monuments suggests that during those desperate days formerly cultivated land in Norfolk, Suffolk and Wessex became infested with weeds and scrub. It is possible that a preceding period of success in agriculture had led to soil exhaustion. Fighting over scarce resources became more common, and in some areas it seems a new trend in castle building began, by surrounding hilltops with ditches and banks. In other areas a different approach was taken. At places like Stonehenge and Avebury sacred sites were constructed, consisting, once again, of circular earth banks and ditches, often with representational circles of wooden uprights or standing stones. Many interpretations of these mysterious structures have been attempted, but thinking about them as part of the history of castles might, I suggest, be instructive. These spiritual sites sought security just as powerfully as castles. This is true even though symbolic circles of standing stones or ditches offered little more physical security than the circle on the cover of Protect and Survive. So many aspects of ritual sites mimicked castle sites. They both used circular banks and ditches. Castles would often have a palisade of wooden uprights on top of their earth banks. Ritual sites would mimic these uprights in their own symbolic wooden, or later stone, uprights.

The hill on which fortifications were built was also important in a religious sense. Hills had long been associated with refuge in times of crisis. They had also been long seen as spiritual shrines. The Hindus had their mythic Mount Meru, the Japanese revered the goddess Fujiyama, who dominated the landscape from Mount Fuji. And the Christians had Mount Sinai where Moses was given the ten commandments. With hills and mountains being spiritual places, it made sense to build artificial hills to celebrate the gods. The Egyptians did this with their pyramids, the people of Mesopotamia with their ziggurat, and the Maya with their temples at Uxmal and Chichen Itza. In England neolithic people built their own ritual hills, and a dramatic example can be seen as a huge mound built close to Avebury stone circle, known as Silbury Hill. Silbury mimicked hilltop fortifications in being nothing less than a hill itself in a stylised form. The close relationship of a ritual hill and a hilltop castle was demonstrated millennia after Silbury Hill's construction by its use during Saxon times as a fortification. Post holes on the top of the hill indicate that this stylised fort actually took the short step towards becoming an actual fort.

The final way in which ancient religious monuments mimicked castles was in the provision of processional ways leading towards them. Processional ways can be seen at Stonehenge and Avebury. In the words of walking historians Nicholas Rudd-Jones and David Stewart, the act of walking in a large group of people towards a monument would have been an "expression of togetherness and resolution" ( Pathways P31). What this really means is that the procession mimics an army on the move.

Maiden Castle

As circular sacred sites were developed and embellished, so the similar hilltop castles became more elaborate. This is particularly true of the Iron Age, around 500BC, when the advent of iron resulted in production of more formidable weaponry. Maiden Castle in Dorset, which began its history in the Neolithic period, became a huge castle in the Iron Age, and is a remarkable survivor from this time. It was at Maiden Castle that ancient Britons made one of their last stands against Roman invaders. And it was the Romans who were to change castle architecture, with their expertise in the use of masonry. One of the most impressive remains of a Roman Castle can be seen at Pevensey in East Sussex. But even after this great change the parallel between physical and spiritual security in castle building remained. The Romans established their first city in Britain at Colchester in Essex, and a vast Temple of Claudius was built there. During Boudicca's rebellion against Roman rule in AD60 the Roman population of Colchester barricaded itself inside the Temple of Claudius and used it as a castle. They held out for two days before their defences were overwhelmed.

Exeter Cathedral, with its castle-like towers and battlements

Once Christianity came to Britain, first during the later Roman period, and then after 597AD with the arrival of St Augustine, church architecture continued to take its lead from castle architecture. Early Saxon churches were built within the confines of Roman castles at Reculver and Richborough. In appearance the new Christian churches were nothing less than stylised castles. Have a look at virtually any church, and you will see towers, battlements, slit windows in the shape of a cross, through which people seeking spiritual security could fire their metaphorical arrows. Following on from the Saxons, the next great castle builders in Britain would be the Normans, who built castles all over Britain following their invasion in 1066. Initially there were strong echoes of the past in Norman castle design. Working quickly the Normans threw up huge mounds, called a motte, with a wooden fortification on top. The entrance at the bottom of the mound was defended by its own wooden fortification, called a bailey - echoes of Silbury Hill and the hilltop forts here. Norman mounds can still be seen, at Tonbridge, Oxford, Old Sarum, Arundel and Windsor amongst many others. The original wooden fortifications have of course gone, but an example has been recreated at Mountfitchet in Suffolk. A few of the earliest Norman castles were built in stone, such as Chepstow and Monmouth. And it wasn't long before the original wooden motte and bailey castles were all replaced by stronger stone structures. Interestingly some of the most important builders of castles at this time were also builders of churches and cathedrals. Bishops often played major military roles. Bishop Gundulf of Rochester, known to his contemporaries as "very competent and skillful in building in stone," built the royal castle at Rochester in Kent, beside the river Medway. He also built neighbouring Rochester Cathedral. Possibily Gundulf was also builder of the White Tower at the Tower of London, and the massive Colchester Castle in Essex, built, fittingly on foundations of the Temple of Claudius where Colchester's Roman inhabitants made their last stand against Boudicca in AD60.

Bodiam Castle, East Sussex

Castles then became more sophisticated. The late thirteenth and early fourteenth century king Edward I brought many dark secrets of effective castle building back from the Holy Land where he had been on Crusade. Edward built a number of castles in north Wales during his campaign to subdue the Welsh, and these were among the most advanced of their time. Some, such as Harlech were built as efficient fighting machines, whereas others, such as Caernarvon, were more symbolic in nature, demonstrating the impressiveness of Edward's power. It wasn't long before this symbolic impressiveness took over, to a large degree, from the actual military value of castles. Only a few decades after Edward I's death, castles were generally being built for their looks. Leeds Castle was valued for its beauty, and rather than being involved in any unpleasant fighting was given as a gift to a succession of medieval queens. In a similar vein, Sir Edward Dalyrigge, a soldier and a statesman, wanted an impressive house to reflect his status. As a loyal supporter of Richard II he was given permission to fortify his manor house at Bodiam in East Sussex. Once he'd got this permission, Sir Edward decided to build a completely new house down the hill from his old mansion, and this building became Bodiam Castle, completed in 1385. It was designed primarily to look beautiful and impressive, and it is rather like the gated, fortified mansions of today's Hollywood stars. Meanwhile further north the powerful Neville family had built lovely Raby Castle in County Durham. Raby was not a fighting castle, but a symbol of the family's power and wealth. This wealth was gained mainly in wars against the Scots. Fortifications involved in the actual business of warfare were utilitarian pele towers built further north. Raby is far too beautiful to have battles spoiling its romantic peace. As usual with castles there is an ambivalence about Raby. Religious buildings still shared architectural features with castles, and the peaceful, spiritual purpose of a church is not very far from the emotions that a beautiful castle like Raby can evoke. The similarities between the earliest circular ditch and earth bank castles, and the earliest ditch and earth bank religious sites, are still with us in castles like Raby.

Walmer Castle

Then into Tudor times in the fifteenth and sixteenth centuries the military, symbolic and religious nature of castles became ferociously intertwined. These were years of religious strife. To allow his divorce from Catherine of Aragon, Henry VIII had switched the religion of England from Catholicism to Protestantism. This led to short lived fears of invasion from catholic France and Spain. Although the threat of invasion was short lived, a huge building programme of shore line defence began in 1539. A chain of forts built along the south coast included Camber Castle in East Sussex, Walmer Castle, and Sandown Castle in Kent, Southsea Castle at Portsmouth, Hurst Castle and Portland Castle in Dorset, Calshott Castle at Southampton, Yarmouth Castle on the Isle of Wight and the sister fortifications of Pendennis Castle and St Mawes Castle in Cornwall. The functional appearance of these castles belies their largely symbolic role. The threat of invasion was brief, but the effect of changing a religion was explosive, and indeed aftershocks remain with us today, most clearly in Northern Ireland. Religions are designed to hold people together and maintain hierarchy and discipline. With a change of religion and the possibility of division, England needed to feel itself pulled together by the illusion of imminent invasion, which apparently could only be countered by building huge forts. The symbolism was taken further in the way stone from demolished monasteries was used to build Henry VIII's forts. The solid walls of these forts, almost all of which survive, is the physical manifestation of a struggle of ideas and beliefs. The south coast castles were not really built to face an external enemy. Instead they were designed to create a symbolism that would prevent religious divisions appearing from within.

Corfe Castle

Castles were also important in the next great age of national division, during the seventeenth century. The seventeenth century saw civil war as Parliament took on the royalist supporters of Charles I. Following the Civil War Parliament went to great lengths to destroy many castles. They did this because of what castles stood for, as much as to neutralise any military threat they now posed. Castles were the symbol of an old world of divinely appointed monarchs, which had now apparently passed. Windsor Castle was saved by only a single vote in Parliament, while beautiful castles such as Corfe in Dorset were systematically destroyed with explosives. And in many ways the age of the castle had passed. The rich were no longer building castles as symbols of their power. Since the reign of Elizabeth I society had been sufficiently stable for rich men to spend their money on beautiful houses, such as Longleat. Castle technology now seemed to have moved to the utilitarian. During Charles II's reign a huge fort was built at Tilbury beside the Thames east of London. And yet even in this rather bleakly utilitarian fortification there are same strange echoes of ancient spiritual sites where we started this journey: Most of the fortifications at Tilbury consist of earth banks.

Castle Drogo

Then as we come towards the modern age, with the concrete gun emplacements of twentieth century wars, we find even this type of architecture reflected in the fairy tale sentiment of castles. It is often said that the last castle to be built in Britain was Castle Drogo on Dartmoor. Castle Drogo was built not to protect any territory, but as a home for Julius Drewe, who retired a very wealthy man after running the Home and Colonial Stores. He wanted a castle to reflect his wealth, and hired a reluctant Edwin Lutyens to design it for him. Lutyens wanted to build a house, but Drewe insisted on a castle. So in 1910 land was purchased and work began. The design included traditional elements of castle design, such as towers and battlements; but it also included some modern concrete bunker chic, as can be seen in this photograph. Castle Drogo of course had no use as a military building, and was simply a show piece. But this was nothing new in castle design. Castles have always existed on a spectrum from functional fortification, to fairy tale kingdom. From the earliest castles symbolism has been as important as physical presence. Fascinatingly the "last castle in Britain" stands across a Dartmoor gorge from one of the very first castles in Britain. Drewe is supposed to have looked at the earth banks and ditches of the Iron Age Cranbrook Castle on Dartmoor, and decided that it should have a sister castle on the other side of the gorge. In this way he decided on his site for Castle Drogo. Ever since Cranbrook Castle was built thousands of years ago, castles have been contradictory structures. They have been places of war, and yet their architecture is reflected in the peaceful places we design in seeking spiritual security. Cathedrals have borrowed from their architecture. Bishops have found themselves building both cathedrals and castles. People have taken refuge in cathedrals, using their symbolic security, in just the same way that others have taken refuge in castles. Castle Drogo is no less a real castle in simply appearing as one.

View of the entrance to Dover Harbour from Admiralty Casement beneath Dover Castle

Seemingly castles are no longer useful to us. In the face of modern war their symbolism, and their physical defensive capabilities, seem pointless. During the twentieth century politicians and leaders began to take cover underground in hidden bunkers, such as the Cabinet War Rooms in London, or Scotland's Secret Bunker near St Andrews. At Dover Castle, a site of fortification since Roman times, an underground Cold War command centre was built. The rest of us meanwhile have had to make do with silly government publications with a cover picture showing a family inside a circle. And yet we still value castles. We visit them, feel romantic about them, spend money maintaining them. This is because, like churches, castles are spiritual symbols. The oldest building at Edinburgh Castle is not the huge castle building, which has been destroyed and rebuilt a number of times, but tiny St Margaret's Chapel. This nine hundred year old building was protected by its symbolism, expressed in tiny, stylised battlements on each end of its roof. The chapel used the symbolic power of the magic circle, and outlasted impressive castles around it. This might be reassuring for that poor little family in their circle on the front of Protect And Survive. And in the end, as we saw with St Margaret's Chapel, symbolism has a power that outlasts simple physical security. Perhaps I shouldn't feel so bad that while VIPs bury themselves in underground bunkers, I have a magic circle.

©2007-2009 InfoBritain


Liver cancer

Primary liver cancer is separated into:

  • Hepatocellular carcinoma – HCC (90 %)
  • Intrahepatic cholangiocarcinoma – IHCC (10 %)

Liver - Essential facts

HCC is is one of the most common cancer diseases on a global basis. HCC occurs most commonly among men. IHCC is not as common as HCC, however the frequency is increasing. Liver and intrahepatic cholangiocarcinoma represents 2.3% of all new cancer cases in the United States. In 2016, it is estimated that there will be 39,230 new cases of liver and intrahepatic cholangiocarcinoma in the United States. (10)

Age-specific incidence of liver cancer, 2009–2013.

Source: Cancer Registry of Norway

Incidence of liver cancer, 1954–2013.

Source: Cancer Registry of Norway


Fight or Flight Causes “Mental Illness”

“Fight-or-flight” is a concept I discuss in depth in “Pack Leader Psychology,” because I believe this primal fear response is key to understanding human behavior. This natural survival instinct is also a powerful driver of human emotions and interactions, yet psychiatrists and psychologists seem to have ignored this important fact when developing diagnostic and intervention theories.

I believe we in the profession and in the general public should talk more directly about the fear response. As a psychotherapist, I believe that if we more routinely label these behaviors people will not only begin to understand them, but the behaviors will be normalized. By calmly and clearly explaining a behavior, such as anxiety or depression, as a normal, primal response, perhaps some of the mystery about human behavior and psychology will be removed. It should not abrogate responsibility for these behaviors, especially the violent, abusive behavior that often accompanies the “fight” response, but at least it will increase awareness.

I believe the psychology profession has, for too long, used obscure, confusing terminology. What could be more primal and clear than “avoidance, freeze, flight and fight?” These are behaviors that every animal understands at the level of the survival instinct and to label these reactions as “mental illnesses” is incorrect, stigmatizing and may reduce the effectiveness of therapy.

I routinely explain the “fight-or-fight” response to clients in therapy and many have heard of it, but never applied it to their own behavior.

In “Pack Leader Psychology” I also add new layers of understanding to this concept, explaining why people today are so quick to flip into a fear response in today’s world and how to stop this behavior.

Fear is not a Mental Disorder: Or What is Really Wrong with the DSM

As the American Psychiatric Association (APA) prepares to publish the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in May 2013, there has been considerable debate about the changes in this document. Client advocacy groups and professional interest groups have stated many objections to DSM-5, with most complaints focusing on specific changes in diagnostic criteria, on placement of diagnostic categories, or on inclusion of diagnostic categories or criteria. Specific complaints about the diagnostic categories include:

  • Asperger’s syndrome should not be on the autism spectrum
  • the addition of disruptive mood dysregulation disorder (DMDD) may pathologize normal childhood temper tantrums
  • the definition of major depressive disorder should not be broadened to include normal bereavement

In addition, more broad-based, theoretical concerns have been expressed by such groups as the American Psychological Association’s Division 32: Society of Humanistic Psychology. In a thorough and thought-provoking letter to the APA in 2011, the group stated that, “it is time for psychiatry and psychology collaboratively to explore the possibility of developing an alternative approach to the conceptualization of emotional distress.”

The controversies surrounding DSM-5 have once again brought up a debate in the profession that the entire atheoretical construct of the DSM should be reconsidered from the ground up. Given the well-documented shortcomings of the DSM, I wholeheartedly concur and have written an essay titled Fear is Not a Mental Disorder The profession needs to move beyond arguing about minor reshuffling of diagnostic categories. These complaints may certainly be justified, but actually are just a rearrangement of the deckchairs on a poorly designed, poorly constructed, and doomed Titanic. The psychology profession must lead an effort to develop a new, improved, and fact-based diagnostic system that is more accurate, clinically useable, beneficial to clients, and provides an effective therapeutic framework.

I am a practicing clinical psychologist who for years has believed that the DSM is inaccurate and misleading in fundamental ways and could even be considered harmful to clients. The mythology of the DSM has for decades hindered therapeutic treatment of clients, and generally complicated what are very simple, understandable concepts that underlie human behavior.

I am not going join the argument of whether Asperger’s is or is not on the autism spectrum, or whether children who throw temper tantrums should be diagnosed with DMDD. Rather, this essay will take a broad, philosophical look at concerns about the DSM. I believe, as many do, that the time is right to completely re-conceptualize diagnostic strategies from the ground up, with the goal of developing a replacement for the DSM.

In Fear is Not a Mental Disorder, I present a powerful and concise theoretical framework to use when diagnosing human behavioral and emotional distresses. This new paradigm called Natural Psychology is explained in depth in my book Pack Leader Psychology. This paradigm offers numerous benefits not found in the DSM, corrects many of the theoretical errors in the DSM, and provides an effective diagnostic and therapeutic solution. And it does so in far less than the 943 pages of the DSM-IV-TR.

Natural Psychology is based on indisputable facts, not the unscientific, confusing, and complex “system” of “diagnostics” of the DSM. Most important, the Natural Psychology model brings numerous benefits to clients, whom we in the psychology profession are ethically bound to protect and help. Where the DSM pathologizes human behaviors as illnesses and disorders, Natural Psychology offers an innovative paradigm that explains these behaviors as normal, natural responses to perceived or real threats and fears. Natural Psychology is a more positive, optimistic, and straightforward framework that strips away harmful, judgmental labels and de-stigmatizes “mental illness” in a profound and fundamental way.

Quite simply, Natural Psychology is based on this concept:

The majority of “mental disorders” that people experience are due to the primal fear response. Fear is not a disorder, but a normal, adaptive human reaction.

I realize that criticizing the “bible” of the psychiatric profession may be sacrilegious to many, but I believe the psychology profession has a duty to serve clients. Keep an open mind as you read this essay. Remember that just because the DSM has an aura of scientific precision, does not prove that its ideas are valid. The DSM is published by a major medical organization and is loaded with technical language, complex numbering systems, obscure terminology, and weighs an intimidating three pounds, but that does not make its precedence unchallengeable.

The publication of the DSM-5 may the tipping point in a history of over-reaching and misinformation by the American Psychiatric Association, forcing the psychology profession to take action.

In Fear is Not a Mental Disorder I will discuss:

1. What is the DSM?

2. How the DSM ignores major psychological facts and concepts

3. A new diagnostic paradigm called Natural Psychology

4. 10 reasons why Natural Psychology should replace the DSM

I recognize these ideas are controversial, but please keep an open mind, click on the link to open the PDF and read the entire essay.   Then join me in a discussion about the DSM-5 and mental health diagnostics in general. I would LOVE to hear your comments.

PDF of Essay:  Fear is Not a Mental Disorder


Tech News

‘Ladies in SaaS’ gains momentum in Indianapolis

Building and sustaining a professional network is challenging, but it’s twice as hard when the kind of group you’re looking for simply doesn’t exist. That’s how Kristen Hamerstadt and Robyn Miley ended up starting Ladies in SaaS, a casual, community networking group for professional women in tech and software-as-a-service. More opportunity for everyone Kristen was

IoT: Convenience at the expense of privacy and security?

We live in a connected world. So connected that we have to schedule vacations specifically to escape the noise of constant advertising, work emails, group texts, friend requests, and countless other distractions vying for our attention. Still, being accessible is a double-edged sword: despite the nuisance of nearly ubiquitous attachment to technology and media, connectivity

Appirio accelerating growth, doubling hiring in Indianapolis

Biggest Tech Announcements and Trends of 2016

10 Most Viewed Stories of 2016

Each week, TechPoint shares news and stories that highlight Indiana tech companies and the people who start, build and support them. In 2016, we shared 229 local and national media stories to our Latest in Tech feed and published 196 original stories to our website, proving that our community is innovating, developing and building a lot worth

Healthcare CRM collecting awards, growth and momentum

When we last wrote about a year ago, the leading cloud-based healthcare relationship management software company was focused on explaining the value of healthcare CRM (customer relationship management) in a post-Affordable Care Act (ACA) healthcare marketplace. As the company that literally coined the phrase and invented the first healthcare relationship management platform, it’s a

Indy’s new scale-up focused tech campus impresses

Tech companies at every stage have been known to create office space where form and function are one in the same. Young startups may choose open coworking spaces that allow for flexibility in use and increase team collaboration. Enterprise tech companies have the ability to build out an office building that suits their needs from

Hanna Bennett puts down roots at Pondurance

For many Millennials, the opportunity to work remotely and travel the country is not an unreachable dream. Hanna Bennett considers herself an adventurer and is constantly looking for new places to visit and explore. She always wanted to move away from her hometown, a small city outside of Detroit, where most people are born, raised and


Genome wide predictions of miRNA regulation by transcription factors

Matthew Ruffalo and Ziv Bar-Joseph

Reconstructing regulatory networks from expression and interaction data is a major goal of systems biology. While much work has focused on trying to experimentally and computationally determine the set of transcription-factors (TFs) and microRNAs (miRNAs) that regulate genes in these networks, relatively little work has focused on inferring the regulation of miRNAs by TFs. Such regulation can play an important role in several biological processes including development and disease. The main challenge for predicting such interactions is the very small positive training set currently available. Another challenge is the fact that a large fraction of miRNAs are encoded within genes making it hard to determine the specific way in which they are regulated.

To enable genome wide predictions of TF--miRNA interactions, we extended semi-supervised machine learning approaches to integrate a large set of different types of data including sequence, expression, ChiP-Seq, and epigenetic data. As we show, the methods we develop achieve good performance on both, a labeled test set, and on when analyzing general co-expression networks. We next analyze mRNA and miRNA cancer expression data demonstrating the advantage of using the predicted set of interactions for identifying more coherent and relevant modules, genes and miRNAs. The complete set of predictions is available on the supporting website and can be used by any method that combines miRNAs, genes and TFs.

Genome-wide predictions of TF regulation of miRNAs, for 202 TFs and 2588 miRNAs


Author(s): Ken Willette. Published on November 2, 2015.

The Thin Purple Line

How the fire service is increasingly partnering with law enforcement. BY KEN WILLETTE

RECENTLY, A NUMBER OF SHOOTINGS of police officers have underscored the dangers of serving in law enforcement. As with firefighting, unforeseen events can turn an incident from routine to deadly. In their aftermath, we are reminded of the critical role played by law enforcement, the thin blue line standing between society and those who would do it harm.

Increasingly, that barrier is becoming a thin purple line, as the blue of law enforcement is joined by the red of the fire service in a variety of incident responses. Firefighting, emergency medical care, and technical rescue activities are being performed under the armed protection of police—a practice highlighted by instances where firefighters responding to fires have been targeted by shooters and, in some cases, killed or wounded.

NFPA has always had a strong bond with the fire service and has supported it through an extensive library of standards focused on equipment, training, and health and safety. But considering the risks all responders face today—as well as that necessary blurring of the blue line into purple, where fire and law enforcement work together as a unified resource—NFPA is seeking to better serve the needs of law enforcement and reduce the risk of line-of-duty deaths and injuries.
We’re doing this in a variety of ways. NFPA is an active member of the Interagency Board, a federal advisory board comprised of a variety of first responders, including law enforcement. For several years, there has been a law enforcement presence on NFPA’s technical committees, notably the Technical Committee on Hazardous Materials Response. Law enforcement members have also assisted as technical advisors to our Alternative Fuel Vehicle Responder Safety Program.

Two years ago, NFPA approved a new standard addressing utilization of self-contained breathing apparatus (SCBA) for non-firefighting activities, such as tactical response teams and response to drug lab incidents. A new technical committee with strong law enforcement representation was established, and today the proposed document NFPA 1986, Respiratory Protection Equipment for Technical and Tactical Operations, is accepting public comments until February.

NFPA’s Standards Council recently approved a new project to develop a standard for dual-purpose breathing apparatus. This equipment can provide the respiratory protection of SCBA when required, but can also function as a purifying air-powered respirator when operating in a less hazardous atmosphere. This was requested by the law enforcement community to address its needs for sustained respiratory protection during events where the level of risk can change. The Standards Council has also approved a new technical committee to develop selection, care, and maintenance criteria for tactical cameras and video equipment (think body and helmet cameras).

Lastly, a request to develop a standard for the training of canine arson accelerant detection dogs has been under extensive review to determine if there is a need to expand beyond the language found in NFPA 921, Guide for Fire and Explosion Investigations.

NFPA is ready and able to draw on its areas of proven expertise to assist law enforcement. Where responders go, NFPA goes, strengthening that thin purple line.


How do you define South Asian?
South Asia contains varied linguistic, social and historical landscapes. Over the course of the last century, the subcontinent went from the hands of European colonisers (English, French, Dutch and Portuguese) and locally ruled princely states to form the current day independent nations of Afghanistan, India, Pakistan, Sri Lanka, Nepal, Bangladesh, Bhutan, Myanmar, the Maldives and Tibet. While colonization by European nations significantly altered these regions, it is neither the beginning nor the end of their histories. Rather than being directed by the binaries of cultural “difference” or “sameness”, SAVAC seeks to look at South Asia as a polycultural space. The region has a shared history and culture in some parts; in many other ways it lacks coherent definition because it contains over 2000 identified ethnic groups who speak over 200 languages.

SAVAC maintains an open and inclusive definition of South Asian that is based in the complexities within the region itself, amongst the various diasporic communities in places like the Caribbean, Africa and South East Asia, and within diasporic populations in the South Asian region. Within the diaspora, notions of home and identity become as blurred and complicated as the concept of South Asia itself.

Given the complexity of South Asia, SAVAC is not limited by political boundaries drawn onto maps and resists the temptation of overdefining and being overdetermined by an a land mass whose borders have been persistently renegotiated. Instead, SAVAC prioritizes themes that relate to the historical and lived realities that South Asian people have encountered over time.

Is SAVAC a gallery?
No. SAVAC is an artist-run centre which operates without a gallery space and collaborates with other artist-run centres, public galleries, universities and museums for exhibitions.
What is an artist-run centre?
An artist-run centre is a non-profit organization started and managed by artists. Artist-run centres emphasize a non-commercial approach to operating by not charging admission fees and by remaining uninvolved with the sale of artwork. ARCs work with professional artists, with a focus on contemporary art. Exhibition programming is often complemented by public screenings, artist talks, panel discussions and publications.

Canada has a unique history of artist-run culture, which began in the 1960s. For more information please check out the following resources:

When did SAVAC change its name to South Asian Visual Arts Centre from South Asian Visual Arts Collective?
SAVAC formally changed its name from SAVAC (South Asian Visual Arts Collective) to SAVAC (South Asian Visual Arts Centre) in February 2008. The name change more accurately reflects the organization’s structure as an artist-run centre: including our membership, being under Board mandate and receiving operational funding.
Can SAVAC sell my artwork?
No. SAVAC is a non-profit artist-run centre, and we operate on a model that is not commercial.
Do I need to identify as South Asian to be a member?
No. SAVAC serves artists who come from various regions and localities in the world, not simply geopolitically-categorized South Asia. SAVAC encourages artists who touch on themes of political/personal, location/identity, assimilation/resistance, architecture/space, city/suburbs, and above all, transnationality as a historical and contemporary force that shapes each individual work and each individual artist.

SAVAC Members don’t necessarily produce work that is solely influenced by fixed entities such as the nations and geographical regions from which their ancestors hailed, or by the ones in which they were born. Similarly, they don’t necessarily adhere to circumscribed notions of “culture” within their own communities or in society at large. The strength and vibrancy of their art lays in the multitude of individual histories–journeys that destabilize, and interrogate fixed notions of culture and identity.

Can I pay for membership fees or publications by credit card?
Credit card payments can only be made online. The membership page, and individual program pages will have the appropriate links to pay online (where applicable). If you wish to pay for membership, a workshop, or a publication using cheque or cash please mail or drop off your payment in person.
What is Member News?
“Member News” is SAVAC’s monthly email newsletter, which includes information about SAVAC’s upcoming programming, member exhibitions and activities, calls for submissions and job opportunities. “Member News” is sent out around the 15th of each month. Members in good standing may send information about exhibitions or other activities, for inclusion in member news. If you are a member and are not receiving the newsletter, please contact us!


Abstract: In this paper we presents a visual system for monitoring children entering and leaving the school bus. It enhances the safety of children during their daily transportation in school bus. The system contains two parts, entry monitoring and exit monitoring. The basic idea is to detect each child using real time face detection algorithms and subsequently utilize face recognition algorithms to determine the actual identification of children when they enter into and leaves the bus. Hence the system identifies the child who fail to get down from the bus. This information will be communicated to his/her parents by issuing an alert message. The system is mainly useful in situation where air conditioned buses are used, that when the bus comes to a halt the temperature inside the bus will rise and when small children forget to get down from the bus it may lead to death. A complete prototype of the proposed system was implemented and tested to validate the system functionality. The results show that the system is promising for daily transportation safety.

Keywords: Face detection, Face Recognition, Principal Component Analysis (PCA), AT commands.


Upgrading to new edition

I have the ebook Hadoop: The Definitive Guide - Third Edition. I see that the Fourth Edition is out as Early Release. There are significant additions, Spark, etc. How do I obtain the new edition? Is it a free upgrade?
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Drüpon Lama Karma

Venerable retreat master (drüpon) Lama Karma was born in eastern Bhutan and joined the Long-Nying Chöling Monastery at a young age. His root teacher was Lama Naljorpa, the great yogi of mahamudra and Dzogchen, from whom he received numerous vows, empowerments, instructions and oral transmissions, including the Chöd Rinchen Threngwa and the Chöd practice of Laughter of the Dakinis from the Longchen Nyingtik Tradition. A heart student of Terton Pedgyal Lingpa Rinpoche, he served as the scribe for the entirety of Pedgyal Lingpa’s Kusum Gongdü treasure cycle. Drüpon Lama Karma studied with other great teachers, including H.H. Dodrupchen Rinpoche, H.H. Penor Rinpoche, H.H. Taklung Tsetrul Rinpoche, H.H Dilgo Kyentse Rinpoche, H.H. Dudjom Rinpoche, and the 16th and 17th Karmapas. He has spent over 13 years in strict meditation retreats. Drüpon is renowned as a genuine retreat master throughout Bhutan and has been one of the most important Bhutanese lamas to disseminate the teachings and maintain the tradition of Terton Pedgyal Lingpa.

Events with Drüpon Lama Karma

Tibetan Healing Chöd
July 18, 2017

The Chöd tradition includes numerous healing rituals and practices to cure illnesses, promote good health, remove obstructions and clear karmic patterns. In this unique retreat, Lama Karma will teach three such practices: 1. Changbu Gyatsa, the “100 handprint” torma ritual; 2. Jungzhi Zerba, a stand-alone sadhana involving torma offerings to…

Dentog Chigma: Chöd Retreat
August 30, 2017

Dentog Chigma is the main sadhana practice within the Rinchen Trengwa (‘The Mala of Jewels’), the collection of practices in Machig’s Kama (oral) lineage compiled by Karmapa Rangjung Dorje and Karma Chakme. Dentog Chigma literally means ‘Liberation on One Seat.’ This marvelous practice is sung with a melody and accompanied…


VOICES Voices Icon Ideas and Insight From Explorers

Kittens-Sighting Is a Big Leap for Florida Panther Conservation

We just learned that at least two Florida panther kittens were found north of Caloosahatchee River for first time in decades. This is groundbreaking news for the recovery of an endangered big cat species and a clear cause for optimism.

1Frame4Nature | Esther Horvath

The mission aboard the 1942 DC3 aircraft is aimed at measuring ice thickness and changes in the Arctic Ocean. Lead scientist, Dr. Thomas Krumpen, has been overseeing the campaign called TIFAX since 2010, covering the same polar region, including Fram Streight and above Northern Greenland towards Nord Pole each year in July -August. During the three weeks campaign in 2016, the team flew a total of fifty hours during 10 survey flights, surveying 2300 miles/3700 km of ice surface. Findings from the campaign revealed surprisingly low summer ice thickness measurements. Since 2010, the Arctic summer ice thickness has reduced by 42%, presumably due to both rising atmospheric and sea temperatures.

Experts say marine protected areas are great but could be better with more staff and funding

A new study suggests many marine protected areas suffer from a lack of adequate staffing and funding–and that’s holding these areas back from reaching their full potential as protective areas for marine life.

Tiger Cubs: A Sign of Hope in Thailand

By Chris Hallam MSc Monitoring Advisor Every success in the conservation world is worth celebrating—no matter what species, location or size of impact. But some feel more significant than others… and the recent news out of Thailand is a perfect example. In Thailand, Panthera has partnered with the Thai Department of National Parks, Wildlife and Plant…

Sudan Border Walk: Pottery Shards Suggest Ancient Bantu Settlements

The slave-raiding here continued well into the beginning of the 20th Century. Cherry saw first-hand, just before the turn of the century, the devastation of villages, and slavers on raids. He witnessed cannibalism on a large scale, of the people who were not considered to be fit to be slaves. So these bits of pottery here are the remnants of one of those villages that may have gotten raided. It was nestled deep in the hills. Further to the north here I have seen entire alternate villages built into the rocky hills for protection from the raiders.

Sudan Border Walk Day 16: First Day Without Someone Being Sick

We reached the river at our target around noon. The water has also come up here. Took an afternoon stroll and saw fresh waterbuck tracks. In the evening, when the sun is going down and it starts to cool off, I am struck by four things: the beauty, the enormity, the thought of all this habitat that is intact (yet empty), and a mixed feeling of desperation and sadness that not more has been done to protect this gem on Earth.

Bhutan: Ecological Heart of the Eastern Himalaya

For a region as rich in biodiversity as the Eastern Himalaya, Bhutan’s healthy population of wild cats, including snow leopard in the north and tiger elsewhere, can serve to repopulate adjoining landscapes as long as the habitats are protected. Bhutan can function as the ecological heart of the Eastern Himalaya, sustaining rural people as well as unique species of wild cats in this large mountainous landscape. For these reasons, investing in Bhutan’s conservation efforts is beneficial to the world!

Sudan Border Walk: A Landscape Ready for Rewilding

As we cross the landscape, I am snapping pictures of the various vegetation types, and thinking about restoring this place. Compared to endless places around the world, I thought this place is like a city for animals that is completely equipped: the water and lights work, the buildings are in place, it just lacks the wildlife. I think about old sheep farms in South Africa, where they remove the sheep, restore the vegetation and watersheds, and bring back every species of large mammal that existed there before. Here, compared to the millions of hectares already restored in South Africa, this place is a piece of cake. The savanna, its forest, grass cover, creeks and rivers, and the remnants of fauna are all here.

The Time I Helped a Sloth to Cross the Road

It was my first day on the southern Caribbean coast of Costa Rica, and I was cycling along the thick forested road on my way to the Manzanillo National Wildlife Refuge, when I came across a strange animal crawling very slowly across the road. When I stopped to take a closer look, I realised it…

Sudan Border Walk: Camping on a Beach at the Chinko River

Hokulea Visits the Pitcairn Islands

The Grekos: A success story in the crackdown on illegal fishing

The battle for the survival of the forest elephant can be won

Top 25 Wild Bird Photographs of the Week #80


“The original home was like a barracks,” recalls architect Jacob Albert of the site, with its falling-down house that resembled a 1960s motor lodge, plus a few charming but run-down old farm sheds. The house had to be torn down, but the sheds remained: The spaces between them and the house site formed appealing courtyard spots worth keeping. The aim, says Albert, was to make a new home “that didn’t look like it was trying to be some old farm house.” The end result was a home with a rambling, relaxed quality, and one that incorporated the refurbished sheds, which are linked to the new house and serve as garage, workshop, storage, and hangout.

The house wears its influences well: The shingles say eastern seacoast, and the gambrel roof is a reminder that a farm was once here. There’s an Arts and Crafts influence, too, with oversized roof brackets that add a playful flourish and details such as the staircase that’s built in a tower the same height as the rest of the house. On the inside, corner windows let light pour into the stairwell while wainscoting adds depth and definition. The stair rail is made of poplar, a hard wood that takes paint well. The rail’s cutouts add lightness and help daylight travel through the stairwell. It’s also a simple way of giving dimension and gracefulness to a staircase without the kind of elaborate carving you’d find in a more formal house. The interior actually has a fair bit of wood trim, but like the stair rail, it’s all accomplished with an impressively light hand.


Why Is There No 13th Floor On Elevators

Why Is There No 13th Floor On Elevators some hotels avoid the number 13 and go directly to 14 when numbering floorings. This holds true for other high structures too. It is since of the condition triskaidekaphobia and a basic dislike of or superstitious notion concerning the number 13. This practice and a few of the beliefs surrounding it have been around given that designers have actually can including that numerous floorings to a structure.

Triskaidekaphobia is an extreme worry of the number 13 As a fear, it is more than simply a moderate pain. Individuals with this condition show signs of intense stress and anxiety when they discover or challenge the item of their worry. Signs consist of queasiness, throwing up, trouble breathing, fast heart beat, sweating and sensations of panic. Avoiding flooring 13 in hotels conserves customers who might experience this condition the pain of remaining in elevators with a 13th flooring or from having space on such a flooring.
View more information: Laminate Flooring Water Damage that You need to Know

Superstitious notion and 13.

Typical understanding has it that worry of the number 13 goes back to among the earliest composed texts-- the Code of Hammurabi. The story goes that the authors of the code neglected the 13th law on the list. Nevertheless, the list has no numbers. However, a superstitious worry of the number 13 did emerge. The number 13 might have been bad in early faiths. Some state Loki was the 13th Norse god. Judas was the 13th to sit for The Last Dinner. Nevertheless, the superstitious notion was not outright till the 17th century.

Why Is There No 13th Floor On Elevators

The primary location where you will see the distinction when it concerns omission of the 13th flooring remains in the elevator. You might likewise observe it in stairwells. These are, for the many parts, the only concrete distinctions. For that reason, hotels are not excluding the 13th flooring. Hotels are merely identifying the flooring in a different way in a couple of locations where these organizations identify the levels. Inning accordance with Otis elevators, approximately 85 percent of elevator panels leave out the number 13.

Why Is There No 13th Floor On Elevators the routine of excluding the 13th flooring in high hotels is a reasonably brand-new one. Skyscrapers did not happen up until 1885. Even then, the very first high-rise building-- the House Insurance coverage Structure-- was just 12 stories high. The custom appears to have started as in fact leaving out the 13th flooring and whatever above it, as critics thought such high high-rise buildings would cast unseemly shadows.


Revolution - Back to the Future

A speech given by Larimer County (CO) Sheriff, Jim Alderden
on July 4th, 2009, in Estes Park, CO

I have a copy because things like this tend to "disappear",
and this is more than "worth reading".

Revolution.  The word has several meanings.

As I use the word today, just in case there are any federal authorities monitoring this gathering and composing a potential terrorist watch list, I mean a sweeping change in the direction government is headed.

I place economy among the first and most important virtues, and public debt as the greatest of dangers.... We must make our choice between economy and liberty, or profusion and servitude.

These are the words of our third President, one of our Founding Fathers and the author of our Declaration of Independence: Thomas Jefferson.

As I speak today about our heritage and foundation and contrast that with where we are and where we appear to be headed I hope you'll forgive me for borrowing liberally from Jefferson and others who were true visionaries and much brighter than me.   Over two hundred years after they were uttered, the words of our Paternal Patriots are just as relevant today as they were then.

Some critics have denounced the attendees of these Tea Parties as Tea-baggers and nothing more than ignorant racists.   I prefer to think of us as Patriots with deep respect for the principles on which this great Republic was founded.

America has been the country that champions individual freedom, not the land of government control leading us like a pack of Lemmings into the sea of self destruction.

America was founded as the land of opportunity - opportunity for all regardless of race, color, creed or religion.  Opportunity to succeed or fail - depending on one's ability and initiative.  The land of opportunity, not the land of entitlement.

The over-reaching of our federal government today can only be described as revolting.

We live in troubling times, a time when complacency has led to unrecognized or ignored danger.  We must be vigilant from threats, threats both from abroad and  within.    We who are gathered here  understand this and are willing to take a stand and be heard, just as the citizens of Massachusetts were in 1773 when they dumped 342 chests of tea from three ships docked at Griffin's Wharf into Boston Harbor.

If there is one thing we should have learned by now, it's that history does repeat itself.

What prompted the original Tea Party?  It wasn't that the colonials didn't like tea.  Indeed, tea was the coffee of the day and colonials drank an estimated six and a half million pounds of tea each year.  The Governor of Massachusetts was appointed by the King and his pay linked to the tax on tea.  One of the largest financial institutions in England at the time was the East India Company, second only to the Bank of England, but it was close to bankruptcy.  To help the failing company, Parliament changed the law on how tea was sold and shipped, basically under-cutting American traders like John Hancock and creating an East India monopoly that benefited a very small group in Boston that included the Governor's two sons and a son-in-law.

Government interference with free enterprise.  Disproportionate taxation!   Back to the future!

As dramatic as the events of that December night were, what is more relevant were the meetings which took place prior to the Tea Party and the efforts to have the tea returned to England.  When the first ship to arrive had docked, posters went up urging citizens to gather at Faneuil Hall the next morning.   As reported in the book Patriots: The Men Who Started the American Revolution by A.J. Langguth, a crowd of over 6,000 gathered there in violation of the government restriction which limited the size of Town Meetings.  The men gathered said that even though they didn't own enough property to qualify to vote, their sons someday would and that they were entitled to protect their children's future.  --  So are we!   Not only entitled to protect their future, but bound to.

So, why we are gathered here today?  Join me in being heard!

The following frequently used quotation is attributed to Scottish history professor Alexander Tytler.   He made his observation shortly after the Revolutionary War, about the same time the Constitutional Convention was being held in Philadelphia.

Back to the future!   Dr. Tytler continued:

The accuracy and source of this quote have been debated, but the observations  seem to conform to our history.  It does appear that history repeats itself.  If you recall one of the definitions of "revolution" as a circular movement around a point, it does appear that we've come nearly full circle:
from the figurative bondage of the oppressive taxes and duties imposed by various acts of the British Parliament
to the spiritual faith and courage shown by the Son's of Liberty
to the Declaration of Independence and freedoms guaranteed under our Bill of Rights
to the abundance our great nation enjoyed through much of the 20th century
to the complacency and apathy that has slowly permeated our society over the past few decades
and finally, to the dependency we see today.

I have a great deal of respect and admiration for our Founding Fathers - for what they accomplished and the risks they took to win our independence.  Let me share with you some of their thoughts on democracy.

Thomas Jefferson expressed the same concern as Dr. Tytler but did so much more succinctly, stating:

John Adams observed:

The question for us is this:

Is it possible to move from this stage of dependence, by-passing the stage of figurative bondage and move back in time to a new era of spiritual faith, great courage, liberty and independence?

I would argue and pray that it is possible - that it isn't too late - because our government is not a pure democracy.  Our Founding Fathers understood the inherent dangers of a pure democracy, where strict majority rule threatens the inalienable rights of the individual.  They understood the fundamental difference between a pure democracy which is equated to mob rule, and a Republic which is a representative form of government - operating under a Constitution that places limits on the authority of government and ensures the sovereignty of the individual.

As noted by Jefferson,

An elective despotism is not what we fought for -

It appears to me that our hope for the future lies in the fact that we are a Republic.  But the path back won't be easy and there is no quick fix.  Our Founding Fathers fought for independence - risking everything.   We who are gathered today can do no less.

So, what do we need to do to get back on track?

The first step is to recognize how we got here.  We didn't get here overnight.  It was a slow and incremental deterioration fueled by a liberal media and by a liberal educational system.  We need to restore balance to both.

We need to support media outlets that aren't beholden to the government and which present all sides of an issue.  We need to vigorously oppose such things as the -so-called- Fairness Doctrine.

We need to take back our educational system, from the elementary schools to the universities, holding teachers and administrators responsible for educating our children, not imposing their ideology.  If our public institutions of learning can't do that, then we need to home school our youth or enroll them in select charter or private schools.

WE - need to instill our values in our children, not cede this important responsibility to the schools or media.

Second, we need to stand up, shout and be heard.   We need to continue to gather in protest instead of wallowing in apathy.

We need to actively push for a return to our national foundation - with an emphasis on our individual God-given rights and respect for State rights over federalism.

Third, we need to get politically active - not just by casting a vote on election day - but in working on campaigns of candidates who uphold our ideals.

We need to ensure that all of our elected officials know, understand and uphold our founding principles - from the school board members to the city councilman, from the county commissioner to the mayor, from the sheriff to the governor, from the state and federal legislators to the President.

Leaders who understand and honor the Declaration of Independence,   the United State Constitution and the Bill of Rights.  Leaders who will govern based on our founding principles, not polls.

Leaders who understand their responsibility under a Republic.  Representatives who will truly represent us and our country - not their self interest.  Leaders who aren't in it for the money or to satisfy their ego.

I can't let a speech on the Fourth of July go by without quoting my favorite actor.  In closing, this is from John Wayne playing Davy Crockett in The Alamo:

Republic.  I like the sound of the word.  It means people can live free, talk free, go or come, buy or sell, be drunk or sober, however they choose.  Some words give you a feeling.  Republic is one of those words that  makes me tight in the throat - the same tightness a man gets when his  baby takes his first step or his first baby shaves and makes his first sound like a man.  Some words can give you a feeling that make your heart warm.  Republic is one of those words. Select 07/08/2009.
Video of the speech

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Travel Checklist Part 1 - Things to unravel before you travel

Well! You have taken care of the holy trinity of travelling .i.e. Airfare, Visa procedures, and Hotel accommodation, but is that enough? Travelling abroad can really be a daunting task. You don’t really want to spend a fortune and suffer a below par experience. Would you enjoy a hassle-free trip where everything is well organized? (Who wouldn’t?). Then, it is essential to sort important tasks such as researching about activities at your destination, managing your finances and keeping important things handy. Hence, we present to you a comprehensive list of things to take care off before you leave your home.

1. Travel insurance: It shouldn’t come across as a big surprise. You wouldn’t want to go through the harrowing experience of losing your passport or luggage, missing your connecting flight, or falling miserably sick in a foreign country. Therefore, it’s absolutely imperative to have good travel insurance with you before you start your trip. It’s even more significant if you are a senior citizen, but don’t worry! There are quite a few companies out there offering senior citizen travel insurance tailored to your requirements.

2. Taking care of your finances: Calculate how much money you are willing to spend on your trip and keep close to 30% on you in cash.  You don’t want to be hunting for ATMs in a foreign location where people speak another language altogether. Moreover, you can save on ATM fees for transacting on a bank other than your own. Lastly, don’t expect that the local stalls or stands can provide the convenience of card transactions. So, make sure you have cash or local currency handy. Keeping a mixture of cash, debit cards and credit card is your best bet.

3. Keep a copy of all the details on you: Keep scanned copies of your passport, travel insurance policy, visa (if required), itinerary, and Hotel receipts on your email. Mail a copy to your friends (just in case). You never know when you need these details.

4. Research on your trips: Make sure you do a thorough research on your destination right from weather, culture, transport and so on. You never know where you find hidden gems. For instance, Udaipur offers tourists to travel rural India on cycles; you can enjoy a plethora of water sports just 550 kms from Mumbai Who knew?

5. Take care of anything expensive: It’s always a good practice to keep your expensive phone, camera, tablet etc. at home to enjoy your trip thoroughly. You don’t really want to keep an eye on them throughout your trip and worry about them getting stolen. In case, you think they are an absolute necessity, make sure you keep them in a separate bag and carry it everywhere you go.

Stay tuned for the next part for more enthralling travel trips.


David Cameron’s realised: career development of young people matters

Why not read our latest blog post, Industrial Strategy Boosting Technical Skills?

Surveying Their FutureDavid Cameron, in visiting a training academy in Buckinghamshire, has finally realised: the careers of young people are key to the Country’s future.  The Prime Minister sees the same twin-track career choice as Tony Blair.  It was the Blair government that introduced the idea that 50% of the population would go to university and the other 50% would not.  Now Mr Cameron has added that those not destined for academic learning should join an apprenticeship.  Laudable perhaps but just how does a young person make the choice?  And how does the wider social context affect career development of young people?

Mr Cameron went on to suggest that the UK should “emulate Germany, where the majority of teenagers either go to university or into an apprenticeship after they finish their exams”.

TimelessTime has written extensively on this subject, comparing UK’s skills with those of Germany and USA.  You can read more here and here.

A report from the Centre for Economics and Business Research predicts that completed apprenticeships over the next 10 years could contribute up to £3.4bn a year to the UK economy by 2022 through increased productivity.  This recognises the basic relationship between enhanced skills and knowledge and output.

Read TimelessTime’s latest research on the matter in our White Paper.  This paper discusses how young people make career choices both at the critical stage when leaving secondary school and later in life as they chart their way through the maze of options after tertiary education or apprenticeships.

Managing people is complex. Get specialist help.

Call Us Today


Proven 4 Essential Oils Anti-anxiety Remedies

If you suffer from anxiety disorder or occasionally experience panic attacks, you might want to consider 4 natural remedies that have been found to be effective in treating these conditions, without the side effects of anti-anxiety drugs.

Bergamot Essential Oil

In a study published in the medical journal, Phytotherapy Research, scientists found that inhaling the essential oil of bergamot had a pronounced anti-anxiety effect in rats. According to their research, bergamot seemed to work by reducing the body’s stress hormone production. Excessively high levels of stress hormones are contributing factors in anxiety. Additionally, bergamot was found to increase levels of gamma-aminobutyric acid (GABA) in the brain.

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  Ball Don't Lie: Making a Case for Core Stability

Fonti, Fabio; Maoret, Massimo

Soccer fans: Real Madrid or Atlético Madrid? Basketball fans: Lakers or Celtics? IESE's Massimo Maoret, professor of strategic management and 2014 recipient of a European Commission Marie Curie research fellowship, argues that these are not simply questions of sport allegiances, but rather fundamental strategic dilemmas faced by every firm. "These teams strategize about their human resource management in very different ways," Maoret says. Human resources are arguably the most overlooked aspect in business strategy nowadays, but they can be the key to unlock competitive advantage.

Take the comparison between Madrid's two winning teams. Their staffing decisions highlight a fundamental trade-off between stability and change. Stable working relationships form the building blocks of social capital -- a resource embedded in firms' networks that breeds efficient routines, trust and cognitive alignment. Social capital is found in abundance on Atlético's winning team. On the other hand, firms often face the dilemma of breaking up relationships to bring in new talent, what economists call human capital. Real Madrid is known for its human capital -- i.e., the field's superstars. A dilemma thus follows: Should I improve my firm's talent pool but sacrifice the stability of its internal network? Or, should I pass on the new star to keep the core of my team intact?

An article forthcoming in the Strategic Management Journal, by Fabio Fonti of ESC Rennes School of Business and Maoret, aims to inform this dilemma. And to do so, the co-authors took it to the basketball floor.

Human and Social Capital: An Odd Couple
While previous studies have found social capital important to software developers and surgeons, Fonti and Maoret looked at the National Basketball Association (NBA) in the United States for their research. Much like firms that compete in markets, they found highly interdependent coworkers aiming to shoot, score and win.

"To better understand the interplays between human and social capital, talent and networks, we needed to find an empirical setting that allowed us to answer a set of important questions," Maoret explains. "First, is human or social capital more important for performance? Second, how does social capital impact performance? And third, when are these two forms of capital rivals, and when are they mutually reinforcing?"

The authors found that, on average, social capital is as important as human capital for determining performance. However, not only are stable working relationships -- the building blocks of social capital -- important in and of themselves, but the positions of these relationships in a social network also matter to organizational performance. For a more nuanced view of social capital at work, the coauthors insist that not all relationships are the same: there are core and peripheral players in an organization's social networks. "Organizational cores are where highly interdependent activities occur -- for instance, your R&D units," Maoret explains.

On the basketball court, the co-authors find clear examples of core and peripheral players. And they also find the NBA has a trove of team data. Specifically, they look at 48 years of statistics on wins, scores, passes and blocks for the world's most competitive basketball league.

In Fonti and Maoret's study, core and peripheral positions in a social network were determined by how much time players interacted together on the court. Based on this principle, the internal collaboration network of the 2009/10 Boston Celtics looked like this:

The data point to five core Celtics players and nine peripheral ones. While in this case the network core overlapped with the Celtics' starting five, in other cases the size of the core varied between three and eight players. The head coach was also considered part of the core.

Three (or Four) Pointers for Managers
The NBA data were analyzed to help determine if social capital matters more at the core than it does at the periphery, controlling for certain variables. The basic answer is yes, but with diminishing returns over time. In other words, relational stability among core players has an immediate, strong impact on performance, but such an effect then plateaus quite quickly. Perhaps that is because the competition is able to study the core players and adjust their own strategies accordingly.

The co-authors also analyze how human capital (players' individual talent) interacts with social capital and its location. Here, looking at the periphery, the study finds that social capital with peripheral teammates can actually hinder the positive effect that human capital brings to performance.

Yet, overall, "stable work relationships among employees generate trust, more efficient work routines, common understanding and thus higher organizational performance," the co-authors summarize, validating results found in previous research.

In the "managerial implications" of this research, executives can find tips for strategic human resource management that may be especially relevant to highly interdependent workplaces. They are:

1. Create structural stability. Focus on creating the conditions for stability by giving employees time to get to know and to adjust to each other. To this end, tolerate short-term inefficiencies of new hires with an eye to long-term results.

2. Avoid temporary workers when possible. While offering short-term, non-guaranteed contracts can allow managers to adjust more quickly to demand fluctuations, the practice undermines the accumulation of social capital.

3. "The war for talent" can generate underwhelming results. Poaching a field's top stars might not be the best solution if done at the expense of team stability, when social capital is lost.

4. Pay more attention to the location of social capital. In hiring decisions, as in real estate, location matters. "Hiring talented core employees is particularly beneficial when social capital is also present in the organizational core, while benefits might be offset by the presence of stable ties outside it," the co-authors explain.

In the end, NBA play can help managers realize that social capital plays a complex role -- on the court and off it. And the showdown between Real Madrid's human capital and Atlético's social capital may yield even more food for thought for strategic management.
This article is based on:  The Direct and Indirect Effects of Core and Peripheral Social Capital on Organizational Performance
Publisher:  John Wiley & Sons
Year:  2016
Language:  English
Go to source


The Cat Food Diet

I go grocery shopping about once a week. I wouldn’t call it a hassle, but it’s certainly not super convenient. Even with a specific list, I often spend 60 minutes wandering the aisles, trying to figure out what to cook. I usually spend $100 per visit, so it adds up to about $400 a month.

There’s always one part of my grocery shopping that’s super simple: Buying cat food. I buy a big bag of hard kibble ($10) and three cases of canned food. Total monthly cost: $20. And that’s for two cats.

Now, I’m hesitant to admit this to myself, but I actually like the smell of cat food. The dry food smells like cookies and the wet food smells like brownie batter. It’s one of the best parts about feeding my cats–inhaling that sweet aroma.

fancy-feast-B0012KH08MAbout a month ago, curiosity got the best of me. Instead of just smelling the cat food like I normally do, I took a spoon to the wet food and tried a bite. I expected it to be terrible, but…it was actually pretty good. Kind of like souffle.

So I tried the dry food, just a few pieces. It may have smelled like cookies, but a more accurate description of the taste is dry cereal.

At first I thought I’d leave it at that. Experiment over. But the next day, I found myself wanting a mid-afternoon snack, and I didn’t want a piece of candy like I usually do. Rather, I wanted cat food. So I scooped some kibble into a napkin and munched away while watching a clip from The Tonight Show on YouTube.

A few days later, I realized that the sandwich I was going to eat for lunch had gotten moldy, and I didn’t have anything else in the fridge. So I really didn’t even think twice about opening a can of cat food. By itself it wasn’t quite enough to insatiate me, but after adding a glass of milk, I was full.

At this point I started to think I was really on to something. I checked the nutrition labels and found that cat food is chock full of the same nutrients and vitamins humans need. I Googled, “Can humans eat cat food?” and I found all these blogs that not only confirmed that cat food is perfectly healthy, but they even encouraged it. There’s a whole movement of people who eat cat food–there’s even a restaurant in Queens that serves gourmet cat food hor d’oeuvres.

In fact, one of the things holding me back was the idea that I like to cook. It hadn’t even occurred to me that I could cook with cat food. So I started experimenting with things like deep fried cat food, cat food burgers on the grill, and cat food stir fry. I loved the variety of textures and flavors.

plated-wet-cat-foodNow, I’m sure you’re wondering at this point: What do my cats think about all this? Well, that’s kind of a silly question, as I have no idea what my cats are thinking. As long as I didn’t eat out of their bowls, they seemed completely unaware of my new diet (though they hang out on the kitchen counter a lot more now when I’m cooking).

Over the last few weeks, 90% of what I’ve eaten has been cat food. I’ve gone out to eat a few times and had regular food, but I found it was disruptive to my digestive system. My monthly food budget has dropped from $100 a week to $15 (though I’m sure that will fluctuate up and down–I’m still trying to figure out the best brand for me). I’ve also lost 10 pounds, and I swear that my sense of smell and night vision have improved. It doesn’t seem possible in such a short amount of time, so maybe it’s just psychological.

I’m not one to impose my lifestyle on others, so I’m not here to advocate the cat food diet (there are other sites like this one that do a much better job of that). All I can say is that it’s a great fit for me, and if you’re “as curious as a cat,” I encourage you to give it a try.


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Presentation on theme: "CHAPTER SIX: DESIGN OF CHANNELS AND IRRIGATION STRUCTURES."— Presentation transcript:

3 6.1 DESIGN OF CHANNELS FOR STEADY UNIFORM FLOW Channels are very important in Engineering projects especially in Irrigation and, Drainage. Channels used for irrigation are normally called canals Channels used for drainage are normally called drains.

4 6.1.1 ESTIMATION OF CANAL DESIGN FLOWS (Q) For Irrigation Canals, Design Flows are estimated Using the Peak Gross Irrigation Requirement For Example, in a Location with the Peak Gross Irrigation Requirement of 7.69 mm/day. Peak flow (Q) = 7.69/1000 m x 10000 x 1/3600 x 1/24 x 1000 = 0.89 L/s/ha For a canal serving an area of 1000 ha, canal design flow is then 890 L/s or 0.89 m 3 /s. Typically, for humid areas, magnitude of discharges are in the range of 0.5 to 1.0 L/s/ha.

5 6.1.2 Dimensions of Channels and Definitions

6 Definitions a) Freeboard: Vertical distance between the highest water level anticipated in the design and the top of the retaining banks. It is a safety factor to prevent the overtopping of structures. b) Side Slope (Z): The ratio of the horizontal to vertical distance of the sides of the channel. Z = e/d = e’/D

7 Table 6.1: Maximum Canal Side Slopes (Z) Sand, Soft Clay3: 1 (Horizontal: Vertical) Sandy Clay, Silt Loam, Sandy Loam 2:1 Fine Clay, Clay Loam1.5:1 Heavy Clay1:1 Stiff Clay with Concrete Lining 0.5 to 1:1 Lined Canals1.5:1

8 6.1.3 Estimation of Velocity in Channels The most prominent Equation used in the design is the Manning formula described in 6.1.3. Values of Manning's n can be found in standard texts (See Hudson's Field Engineering). 6.1.4 Design of Channels Design of open channels can be sub-divided into 2: a) For Non-Erodible Channels (lined) b) Erodible Channels carrying clean water

10 Design of Non-Erodible Channels When a channel conveying clear water is to be lined, or the earth used for its construction is non-erodible in the normal range of canal velocities, Manning's equation is used. We are not interested about maximum velocity in design. Manning's equation is: ` Q and S are basic requirements of canal determined from crop water needs. The slope of the channels follows the natural channel. Manning's n can also be got from Tables or estimated using the Strickler equation: n = 0.038 d 1/6, d is the particle size diameter (m)

11 Design of Non-Erodible Channels Contd. LHS of equation (1) can be calculated in terms of A R 2/3 termed section factor. For a trapezoidal section: A = b d + Z d 2 ; P = b + 2 d (1 + Z) 1/2 The value of Z is decided (see Table 6.1) and the value of b is chosen based on the material for the construction of the channel. The only unknown d is obtained by trial and error to contain the design flow. Check flow velocity and add freeboard.

12 Example 6.1 Design a Non-Erodible Channel to convey 10 m 3 /s flow, the slope is 0.00015 and the mean particle diameter of the soil is 5 mm. The side slope is 2 : 1. Solution: Q = 1/n AR 2/3 S 1/2 ….. (1) With particle diameter, d being 5 mm, Using Strickler Equation, n = 0.038 d 1/6 = 0.038 x 0.005 1/6 = 0.016

13 Solution of Example Contd. Z = 2. Choose a value of 1.5 m for 'b‘ For a trapezoidal channel, A = b d + Z d 2 = 1.5 d + 2 d 2 P = b + 2 d (Z 2 + 1) 1/2 = 1.5 + 2 d 5 1/2 = 1.5 + 4.5 d Try different values of d to contain the design flow of 10 m 3 /s

14 Soln of Example 6.1 Contd. d(m)A(m 2 ) P(m) R(m)R 2/3 Q(m 3 /s) Comment 2.011.0 8.74 Small flow 2.5 16.25 12.751.271.18 14.71 Too big 2.212.98 11.401.141.09 10.90 slightly big 2.111.97 10.951.091.06 9.78 slightly small 2.1312.27 10.11 O.K. The design parameters are then d = 2.13 m and b = 1.5 m Check Velocity : Velocity = Q/A = 10/12.27 = 0.81 m/s Note: For earth channels, it is advisable that Velocity should be above 0.8 m/s to inhibit weed growth but this may be impracticable for small channels. Assuming freeboard of 0.2 d ie. 0.43 m, Final design parameters are: D = 2.5 m and b = 1.51 m

15 Final Design Diagram d = 2.13 m Z = 2:1 D = 2.5 m b = 1.5 m T = 11.5 m T = b + 2 Z d = 1.5 + 2 x2 x 2.5 = 11.5 m

16 Design of Erodible Channels Carrying Clean Water The problem here is to find the velocity at which scour is initiated and to keep safely below it. Different procedures and thresholds are involved including maximum permissible velocity and tractive force criteria. Maximum Permissible Velocities: The maximum permissible velocities for different earth materials can be found in text books e.g. Hudson's Field Engineering, Table 8.2.

17 Procedure For Design i) Determine the maximum permissible velocity from tables. ii) With the permissible velocity equal to Q/A, determine A. iii) With permissible velocity = 1/n S 1/2 R 2/3 Slope, s and n are normally given. iv) R = A/P, so determine P as A/R v) Then A = b d + Z d and P = b+ 2 d (Z 2 + 1) 1/2, Solve and obtain values of b and d

18 Example 6.2: From previo From previous example, design the channel using the maximum permissible velocity method. Solution: Given: Q = 10 m 3 /s, Slope = 0.00015, n = 0.016, Z = 2 : 1 i) From permissible velocity table, velocity = 0.75 m/s ii)A = Q/V = 10/0.75 = 13.33 m iii) ` iv) P = A/R = 13.33/0.97 = 13.74 m v) A = b d + Z d 2 = b d + 2 d 2 P = b + 2 d (Z 2 + 1) 1/2 = b + 2 d 5 1/2 = b + 4.5 d ie. b d + 2 d 2 = 13.33 m 2........(1) b + 4.5 d = 13.74 m........ (2)

19 Solution of Equation 6.2 Contd. From (2), b = 13.74 - 4.5 d.......(3) Substitute (3) into (1), (13.74 - 4.5 d)d + 2 d 2 = 13.33 13.74 d - 4.5 d 2 + 2 d = 13.33 13.74 d - 2.5 d 2 = 13.33 ie. 2.5 d 2 - 13.74 d + 13.33 = 0 Recall the quadratic equation formula: d = 1.26 m is more practicable From (3), b = 13.74 - (4.5 x 1.26) = 8.07 m Adding 20% freeboard, Final Dimensions are depth = 1.5 m and width = 8.07 m

20 6.1.5Classification of Canals Based on Capacity: Canals can be classified as: (a) Main Canal: It is the principal channel of a canal system taking off from the headworks or a reservoir or tail of a feeder. It is a large capacity channel and usually there is no direct irrigation from it. Small capacity ditch distributaries running parallel to the canal are taken off from the main canal to irrigate adjoining areas. Main canals deliver supply to branch canal and main distributaries.

21 Canals Contd. (b) Branch or Secondary Canal: Branch canals take their supply from the main canal and convey to the distributaries. Very little direct irrigation is done from the branch canals. Sub-branch is a canal, which takes off from the branch canal but has capacity higher than a distributary.

22 Canals Contd. (c) Major Distributary: It is a distributing channel, which may take off from a main canal, branch canal or sub- branch and has discharge capacity less than that of a branch canal. It supplies water to another distributary. Distributaries and minors take off from it. Irrigation is done through outlets fixed along it.

23 Canals Contd. (d) Distributary: It is a channel receiving supply from branch canal or major distributary and has discharge less than that of major distributary. Minors take off from it, besides irrigation is done from it through outlets.

24 IRRIGATION STRUCTURES Structures are widely used in Irrigation, water conservation, flood alleviation, river works where water level and discharge regulation are required. These are hydraulic structures that are used to regulate, measure, and/or transport water in open channels. These structures are called control structures when there is a fixed relationship between the water surface elevation upstream or downstream of the structure and the flow rate through the structure. Hydraulic structures can be grouped into three categories:

26 Hydraulic Structures Contd. (i) Flow measuring structures, such as weirs (ii) Regulation structures such as gates and (iii) Discharge structures such as culverts.

27 Weirs Weirs: Weirs are elevated structures in open channels that are used to measure flow and/or control outflow elevations from basins and channels. There are two types of weirs in common use: Sharp-crested weirs and the broad-crested weirs. The sharp-crested weirs are commonly used in irrigation practice

28 Sharp-Crested Weirs Sharp-Crested Weirs Sharp-crested or thin plate, weirs consist of a plastic or metal plate that is set vertically across the width of the channel. The main types of sharp-crested weirs are rectangular, V-notches and the Cipolletti or the Trapezoidal weirs. The amount of discharge flowing through the opening is non-linearly related to the width of the opening and the depth of the water level in the approach section above the height of the weir crest.

29 Sharp Crested Weirs Contd. Weirs can be classified as being contracted or suppressed depending on whether or not the nappe is constrained by the edges of the channel. If the nappe is open to the atmosphere at the edges, it is said to be contracted because the flow contracts as it passes through the flow section and the width of the nappe is slightly less than the width of the weir crest (see figure). If the sides of the channel are also the sides of the weir opening, the streamlines of flow are parallel to the walls of the channel and there is no contraction of flow.

30 Figure 6.2: Rectangular Weirs (a) Suppressed Weir (b) Unsuppressed Weir (Contracted)

32 Sharp Crested Weirs Contd. In this case, the weir is said to be suppressed. Some type of air vent must be installed in a suppressed weir so air at atmospheric pressure is free to circulate beneath the nappe. (See Figure 6.2 for suppressed and unsuppressed weirs).

33 Sharp Crested Weirs Contd. The discharge, Q (m 3 /s) over a rectangular suppressed weir can be derived as: Where: C d is the discharge coefficient, b is the width of the weir crest, m (see Figure 6.2 above) and H is the head of water (m) above weir crest. According to Rouse (1946) and Blevins( 1984), ………………..(2) Where: H w is the height of the crest of the weir above the bottom of the channel.

34 Weirs Contd This equation is valid when H/H w <5, and is approximated up to H/H w = 10. If H/Hw < 0.4, Cd can be approximated as 0. 62 and equation (1) reduces to: Q = 1.83 b H 1.5 ………. (3) This equation is normally used to compute flow over a rectangular suppressed weir over the usual operating range. It is recommended that the upstream head, H be measured between 4H and 5H upstream of the weir. For the unsuppressed (contracted) weir, the air beneath the nappe is in contact with the atmosphere and venting is not necessary. The effect of side contractions is to reduce the effective width of the nappe by 0.1 H and that flow rate over the weir, Q is estimated as: Q = 1.83 (b – 0.2 H) H 1.5 ………………… (4) This equation is acceptable as long as b is longer than 3 H

35 Cipoletti Weir A type of contracted weir which is related to the rectangular sharp-crested weir is the Cipoletti weir (see Figure 6.3 below) which has a trapezoidal cross- section with side slopes 1:4 (H:V). The advantage of a Cipolletti weir is that corrections for end contractions are not necessary.

36 Cipolletti Weir Contd. The discharge formula can be written as: Q = 1.859 b H 1.5 …………….. (5) Where: b is the bottom width of the Cipolletti weir. The minimum head on standard rectangular and Cipolletti weirs is 6 mm and at heads less than 6 mm, the nappe does not spring free of the crest. Figure 6.3: A Trapezoidal of Cipolletti Weir

37 Example 6.3 A weir is be installed to measure flows in the range of 0.5 to 1.0 m 3 /s. If the maximum depth of water that can be accommodated at the weir is 1 m and the width of the channel is 4 m, determine the height of a suppressed weir that should be used to measure the flow rate.

38 Solution to Example 6.3 The flow over the weir is shown in the Figure 6.4 below. The height of water is H w and the flow rate is Q. The height of water over the crest of the weir, H is given by: H = 1 – H w Assuming that H/Hw, 0.4, then Q is related to H by equation (3), where: Q = 1.83 b H 1.5 Figure 6.4: Weir Flow

39 Solution to Example 6.3 Concluded Taking b = 0.4 m, Q = 1m 3 /s (the maximum flow rate will give the maximum head, H), then: The height of the weir, H w is therefore given by: H w = 1 – 0.265 = 0.735 m And H/H w = 0.265/0.735 = 0.36 The initial assumption that H/H w < 0.4 is therefore validated, and the height of the weir should be 0.735 m.

40 V-Notch Weir A V-notch weir is a sharp-crested weir that has a V-shaped opening instead of a rectangular-shaped opening. These weirs, also called triangular weirs, are typically used instead of rectangular weirs under low-flow conditions ( mainly < 0.28 m 3 /s), where rectangular weirs tend to be less accurate. It can be derived that the flow rate, Q over the weir is given by:

41 V-Notch Weirs Contd.

42 Parshall Flume Although weirs are the simplest structures for measuring the discharge in open channels, the high head losses caused by weirs and the tendency for suspended particles to accumulate behind weirs may be important limitations. The Parshall flume provides an alternative to the weir for measuring flow rates in open channels where high head losses and sediment accumulation are of concern. Such cases include flow measurement in irrigation channels. The Parshall flume (see Figures 6.7 and 6.8 below) consists of a converging section that causes critical flow conditions, followed by a steep throat section that provides for a transition to supercritical flow.

43 Parshall Flume

44 Parshall Flumes

45 Parshall Flume Contd. The unique relationship between the depth of flow and the flow rate under critical flow conditions is the basic principle on which the Parshall flume operates. The transition from supercritical flow to subcritical flow at the exit of the flume usually occurs via a hydraulic jump, but under high tail water conditions the jump is sometimes submerged.

46 Parshall Flume Contd Within the flume structure, water depths are measured at two locations, one in the converging section, H a and the other at the throat section, H b. The flow depth in the throat section is measured relative to the bottom of the converging section as illustrated in the figure below. If the hydraulic jump at the exit of the Parshall flume is not submerged, then the discharge through the flume is related to the measured flow depth in the converging section, H a by the empirical discharge relations given in Table 6.2, where Q is the discharge in ft 3 /s, W is the width of the throat in ft, and H a is measured in ft.

47 Parshall Flume Contd Submergence of the hydraulic jump is determined by the ratio of the flow depth in the throat, H b, to the flow depth in the converging section, H a, and critical values for the H b /H a are given in Table 6.3. Whenever, the ratio exceeds the critical values in the table, the hydraulic jump is submerged and the discharge is reduced from the values given by the equations in Table 6.2. Corrections to the theoretical flow rates as a function of H a and the percentage of submergence, H b /H a are given in the Figures 6.8 and 6.9 below for throat widths of 1 ft and 10 ft.

48 Parshall Flumes Contd.

49 Flow corrections for the 1 ft flume are applied to larger flumes by multiplying the correction for the 1 ft flume by a factor corresponding to the flume size given in Table 6.4. Similarly, flow corrections for flume sizes greater than 10 ft. are applied to larger flumes by multiplying the correction for the 10 ft flume by a factor corresponding to the flume size given in Table 6.5. Parshall flumes do not reliably measure flow rates when the submergence ratio, H b /H a exceeds 0.95.

50 Parshall Flume Correction

51 Tables For Parshall Flume Correction

52 Example 6.4 Example 6.4: Flow is being measured by a Parshall flume that has a throat width of 2 ft. Determine the flow rate through the flume when the water depth in the converging section is 2.00 ft and the depth in the throat section is 1.70ft.

53 Solution to Example 6.4 From the given data: W = 2 ft, H a = 2 ft, and H b = 1.7 ft. According to Table 6.2, Q is given by: In this case: H b /H a = 1.7/2 = 0.85 Therefore, according to Table 6.3, the flow is submerged. Figure 6.8 gives the flow rate correction for a 1 ft flume as 2ft 3 /s, and Table 6.4 gives the correction factor for a 2 ft flume as 1.8. The flow rate correction, dQ for a 2 ft flume is therefore given by: DQ = 2 x 1.8 = 3.6 ft 3 /s And the flow rate through the Parshall flume is Q – dQ, where Q – dQ = 23.4 – 3.6 = 29.8 ft 3 /s

54 Gates Gates are used to regulate the flow in open channels. They are designed for either over-flow or underflow operation, with overflow operation appropriate for channels in which there is a significant amount of floating debris. The common types of gates are vertical and radial (Tainter) gates, which are illustrated below. Vertical gates are supported by vertical guides with roller wheels, and large hydrostatic forces usually induce significant frictional resistance to raise and lower the gate

55 Diagrams of Gates

57 Gates Contd. Flow, Q through a gate could be established to be: C c = C c = coefficient of contraction, = y 2 /y g = 0.61 for most vertical gates. ` For For Tainter gates, C c is generally greater than 0.61 and is commonly expressed as a function of the angle (degrees) shown in the diagram above.

59 Gates Concluded It can be expressed as: This equation applies as long as the angle is least than 90 0. All the equations apply where there is free flow through the gates. See texts for situations where the flows through the gates are submerged.

60 Drop Structures: Drop structures, typically constructed out of concrete, can accommodate a sudden change in elevation of the channel bottom while maintaining control of the flow. Drop structures are used in channels, which must be laid along relatively steep gradients to allow for dissipation of energy without causing scour in the channel itself. In such applications, the drop structure allows the main channel to be laid on subcritical slope while the excess potential energy of the flow due to the steep topography is absorbed in the drop structure. See Figure 6.12 of a drop structure below

61 Diagram of Drop Structure

62 Example 6.5 An irrigation channel with a design discharge of 2.265 m 3 /s is to be laid along a terrain having an average slope of 0.005 m/m. To maintain subcritical flow in the channel section, the bottom of the channel must be limited to 0.001 m/m. The extra fall is to be absorbed by drop structures such as the one shown above in the diagram having a width of 3.048 m. Compute the number of structures required in a 16.09 km length of line if the drop height (dZ) is equal to 1.829 m.

63 Solution of Example 6.5 Solution: The total drop to be absorbed by structures, Z T = (S t - S o ) L Where S t is the terrain slope, L is total distance, and S o is the slope of the channel. Z T = ( 0.005 m/m - 0.001 m/m ) 16.09 km = 64.36 The number of drop structures required, N = Z T /dZ = 64.36/1.829 = 36 Structures.

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