Sunday, July 29, 2012

[282] Annotations on Lift Devices

El articulo previo discutia los stairwells, un invento puramente hindu para almacenar grandes cantidades de agua generadas durante los monzones y asi tener agua en todo el periodo seco.  Es particular de esta zona dadas las pobres condiciones del terreno, que no soporta el dise/no usual de charcas con liners. 

Dije en aquel articulo que lo realmente fascinante es como estas opciones se alimentaban con condiciones de baja tecnologia, que no dependian directamente de un motor electrico.  Bueno, desarrollando un poco mas en esa teoria les incluyo este link de la FAO, que establece estos tipos de equipos llamadas 'lift devices' o aparatos que le dan un cabezal de elevacion al agua.

http://www.fao.org/docrep/010/ah810e/AH810E05.htm

Repasando un poco la teoria, debemos conservar la energia.  La energia termal siempre fluye del lado mas caliente al mas frio, lo concentrado hacia lo diluido, y dado la fuerza de gravedad, lo que esta arriba siempre busca bajar.  Un poco mas teorico, la ecuacion de Bernoulli:

Velocity Head + Elevation Head + Pressure Head + Friction Losses = Work Required

Para no entrar en un curso de mecanica de fluidos solo digamos que para poder llevar el agua de un punto bajo a un punto alto necesitamos suplir trabajo (o energia) para poder llevarlo al punto alto.  Esa energia debe ser suficiente para poder vencer las perdidas causadas por todos los factores de la ecuacion.

Los romanos tenian sistemas basados en pistones para subir el agua de sus acueductos.  A su vez los persas hiceron muchas mejoras en sistemas tan eficientes que aun se usan hoy en dia.  Todos estos sistemas se basaban en aplicar esfuerzo (un hombre operando una palanca para subir la cubeta es la mas facil de ver. una ristra de caballos girando un disco con una polea llena de cubos que suben el agua es algo mas complejo pero el mismo concepto.  alguien aplica el trabajo.)

egun FAO:
Water may be moved by the application of any one (or any combination) of six different mechanical principles, which are largely independent, i.e. by:
  1. direct liftthis involves physically lifting water in a container
  2. displacementthis involves utilizing the fact that water is (effectively)incompressible and can therefore be "pushed" or displaced
  3. creating a velocity headwhen water is propelled to a high speed, the momentum can be used either to create a flow or to create a pressure
  4. using the buoyancy of a gasair (or other gas) bubbled through water will lift a proportion of the water
  5. gravitywater flows downward under the influence of gravity

Algunos ejemplos del articulo:
Claro esta, la tecnologia ha avanzado mucho pero estos nuevos sistemas requieren bombas:
Ejemplo mas moderno con molinos de viento:
http://www.ironmanwindmill.com/windmill-history.htm

Inventos adicionales como el tornillo de arquimides:

http://www.hp-gramatke.net/history/english/page0600.htm

Algo de Qanats y Acueductos Romanos:
http://www.facstaff.bucknell.edu/mvigeant/univ270_05/jake_aq/aqueducts.htm
http://www.pbs.org/wgbh/nova/ancient/roman-aqueducts.html
http://www.cais-soas.com/CAIS/Science/aqueducts_iran.htm

Un poco de cisternas.  Un ejemplo fotografiado en Istanbul:
http://seattlestravels.com/underground-cisterns-fish-and-medusa-heads-in-istanbul/

Sobre las preocupaciones del mantenimiento de estos sistemas seguire en otro momento.  Discusiones previas en la Alcantarilla:
http://alcantarillaalquimica.blogspot.com/2011/05/178-introduccion-al-problema-de-los.html
http://alcantarillaalquimica.blogspot.com/2011/03/planificacion-necesaria-tema-3-manejo.html
http://alcantarillaalquimica.blogspot.com/2009/12/necesitamos-empezar-reusar-agua.html

Wednesday, July 25, 2012

[281] Chutes and Stairwells

Interesante sugerencia hecha por Antigonum que decidi indagar, aprovechando el dia medio feriado de hoy, tecnicamente es feriado en una oficina y regular en la otra (pero como la otra me debe todo un fin de semana trabajando we are even).

La sugerencia fue en el articulo [279]: http://alcantarillaalquimica.blogspot.com/2012/07/279-curiosidades-web.html

Y abunda sobre un viejo articulo relacionado a la arquitectura persa y su manejo de sistemas de agua.  En aquel articulo: http://alcantarillaalquimica.blogspot.com/2010/02/los-qanat-en-el-medio-oriente.html
Exponia que los persas eran sumamente ingeniosos y usaban sistemas de ventilacion e irrigacion naturales para sus sistemas.  Quise entrar en un poco mas de detalle sobre ejemplos de esos sistemas y encontre un buen resumen aqui de tres ejemplos de gran relevancia para edificios verdes:


http://www.yellowbluedesigns.com/2012/03/05/3-beautiful-ancient-passive-cooling-techniques-in-modern-architecture/
O sea, la arquitectura moderna comienza a visualizar la simpleza y funcionalidad de estos dise/nos milenarios.  Entre ellos:
[1] Stepwells como el mostrado arriba que sirven de embalse, area de esparcimiento y acceso al nivel freatico por seco que este arriba.
[2] Estructuras para colectar los vientos superficiales para asi ventilar naturalmente los pasillos y estructuras debajo.  Si combinamos esto con un stepwell o un qanat tenemos un sistema de air chiller natural.  O sea aire acondicionado naturalmente.
[3] El uso de quiebrasoles combinados con pasillos de 4 pies de ancho cerrados con quiebrasoles permite la creacion de brisa natural a la vez que estratifica el aire del pasillo del del resto de las estructuras.  Al calentar el quiebrasol en vez del edificio se logra un edificio con un interior mucho mas fresco.

Este articulo enfocara mas en los stepwells.  EL pie forzado para este articulo comienza aqui:
http://jardinssansfrontiers.blogspot.com/2011/03/step-well-back-in-jodhpur-to-enjoy-this.html

Step wells (known locally as bawdi or baoli) are unique to the Western Indian states - a form of water management dating back to the 6th century - conceived to overcome extreme weather conditions in Rajasthan and Gujarat, where there is monsoon for three months of the year, followed by nine months of drought. Construction involved the digging of huge trenches, lined with stone blocks and steps, allowing access to the falling water table throughout the dry months.
The 3,500 Escher style steps at Abhaneri step well descend 13 stories to access water in the dry season

There are step wells throughout India's Western states and one of the finest is found at Abhaneri (above) near Jaipur, where 3500 Escher-style steps descend 13 stories to access the water below. This baori incorporates a temple, and would have served not just as a functional building, but also a meeting place and somewhere to worship, given the scarcity of water in the long, dry months.
 
Este articulo debajo enfoca en los aspectos de insalubridad que trajeron los ingleses a este tipo de cisterna.  Su argumento era que al a/nadir ofrendas de alimentos, flores, aceites, etc. y no tener manera de decantarlos contamina la fuente de agua, por lo que optaron por prohibirlos y sustituirlos por estaciones mecanicas de bombeo.  Sin embargo, entiendo que eso se resolvia con un sistema combinado de filtracion.
http://books.google.com.pr/books?id=KoVCliqcmIIC&pg=PA163&lpg=PA163&dq=stepwells+outside+india&source=bl&ots=pfp7qj61YP&sig=rHNA1rFLVatwBzfey63V7B2HFmM&hl=en&sa=X&ei=gAcQUNrGBIay8QSf0YCgCQ&redir_esc=y#v=onepage&q=stepwells%20outside%20india&f=false
 
Mas temas genericos de Stepwells aqui:
One of the earliest existing stepwells was built in the 11th century in Gujarat and is known as the Mata Bhavani's vav. A long flight of steps leads to the water below a sequence of multi-story open pavilions positioned along the east/west axis. The elaborate ornamentation of the columns, brackets and beams are a prime example of how stepwells were used as a form of art.[8]
The British rule of the Indian subcontinent of that time was not satisfied with the quality of hygiene that existed in these stepwells and instead installed pipes and pumps to replace their purpose. In fact, even the invasion by Mughal rulers did disrupt in the culture practiced in these stepwells. As a matter of fact, they encouraged the building of many stepwells. It was strictly the British that forced abandonment of the wells. Consequentially, the social and religious activity taken place in these places were lost to the authority of the British.[9]
The importance of water to the locations in which they were found have been realized in the past decade now that many communities in the area are scarcity of rain and water. The construction of these wells encouraged the incorporation of water into the culture where they were popular. These stepwells were even proven to be well built after withstanding earthquakes in the range of 7.6 on the Richter scale.[10]


In the northern Indian states of Rajasthan and Gujarat, the problem of water is a profound one. At the edge of the Thar desert, the area sees torrential seasonal monsoons, and then watches the water disappear almost immediately. With summers routinely over 100 degrees, and silty soil that would not hold water in ponds, a practical solution was needed for locals and travelers along the local trade routes.
In the first century AD, the slippery shores of the major rivers were tamed by the construction of ghats, long, shallow sets of stairs and landings. The same approach was applied to the construction of a new kind of well.
The earliest stepwells most likely date to about 550 AD, but the most famous were built in medieval times. It is estimated that over 3000 stepwells were built in the two northern states. Although many have fallen into disrepair, were silted in in antiquity, or were filled in with trash in the modern era, hundreds of wells still exist. In New Delhi alone, there are more than 30.
Water plays a special part in Hindu mythology, as a boundary between heaven and earth known as tirtha. As man-made tirtha, the stepwells became not only sources of drinking water, but cool sanctuaries for bathing, prayer and meditation.
The wells are called by many names. In Hindu they are baori, baoli, baudi, bawdi or bavadi. In Gujarati, spoken in Gujarat, they are commonly called vav.
The architecture of the wells varies by type and by location, and when they were built. Two common types are a step pond, with a large open top and graduated sides meeting at a relatively shallow depth. The step well type usually incorporates a narrow shaft, protected from direct sunlight by a full or partial roof, ending in a deeper, rounded well-end. Temples and resting areas with beautiful carvings are built into many of the wells. In their prime, many of them were painted in bright colors of lime-based paint, and now traces of ancient colors cling to dark corners.
The use and conditions of stepwells began to decline in the years of the British Raj, who were horrified by the unsanitary conditions of these drinking water bathing spots. They began to install pumps and pipes, and eventually outlawed the use of stepwells in some places.
The remaining stepwells are in varying states of preservation, and some have gone dry. Local kids seem to find the ones with water to be terrific diving spots, which seems insanely hazardous.


http://thinkinginsomniac.wordpress.com/2011/02/24/architecture-sketch-stepwells-vavs-in-gujarat-india/

Me llamo la atencion este analisis humanista del proposito de estos stairwells:
http://www.the-utopian.org/post/2340612672/stepwells-and-civilization
The user of the well — when it was still operational — could throw a bucket down into the shaft directly, or be social and walk down the steps to the source. The walk wasn’t necessarily arduous; in the rainy season water could rise as much as three stories, subtracting more than a handful of stairs. Now the steps were damp and mossy, as they are for much of the year, and the water was little more than a rain-fed puddle at the heart of the temple. The Rudabai Stepwell, rejected first by the British for fear of breeding ringworm, and then cheated by water-tables that sank past its reach, is desiccated and defunct — like most stepwells. In 1982, water came up to the second landing of the structure; in 1995, to the fourth; now, unless the rain is stupendous, it refuses to rise at all. The groundwater is too depleted. The first structure in sight as you exit into a dusty courtyard is a monstrous water tank shaped like an upturned drum. This is the community’s source of sustainence.
But the religious purpose of the stepwell still persists. On one hand, the Rudabai Stepwell has been co-opted completely by Hindus — a small, squat, whitewashed temple, built a half-century ago, brashly shares its wall with the southern end of the vav — and on the other, it offers up its sandstone ledges as a sort of museum of cross-religious borrowings. Hindu and Muslim motifs abound and interact. The panels of half-lotuses and flowers running along the walls and the voluptuous inner-leaf vines framed in tiny shrines are patently Islamic in their austerity; the friezes and niches are Hindu. Stepping from platform to platform, I came upon a carving of erotic girls churning butter; a conch of Shiva pressed into the ground; and a few freshly-bathed devotees praying to a shrine of Bhageshwari Devi, the 500 year-old statue freshened with dabs of vermillion powder and curlicues of incense-smoke.
Such secular style is highly unusual, particularly when examined in the glare of Gujarat’s troubled communal history. Cleaved by history and politics, Hindus and Muslims have always lived in an uneasy truce here, but since the anti-Muslim riots of March 2002, the truce has begun to feel more and more like an ambush. The Hindu nationalist Government accused of directing the pogrom is still in power and is presiding over great prosperity. The ills of the state are blamed on Muslims, who are said to reproduce at terrific rates. How do the people of Gujarat live with the thousands of lives that were lost and ruined? The caretaker said, “Outsiders did it. Vajpayee” — the then Prime Minister of India — “did it.” Then he pointed across the top of the stepwell to a man who was squatting over its edge, and said, “Look, he’s a Muslim, and he’s my friend. The riots are a city problem. In villages it was never a problem.” And so it was. Other people I met made rote gestures of communal harmony; a few dipped with evident pain into accounts of mutilations; the majority were consumed by the recent spate of bomb blasts by home-bred Islamic militants. But for most the past remained debatable; everyone was too overwhelmed by the present to mourn.

Cierro diciendo lo interesante de como estas antiguas estructuras no eran para ser temporeras sino para pasar de generacion tras generacion...
 

Tuesday, July 24, 2012

[280] Some Book of Kells

Como he indicado en mis articulos previos, estoy en una especie de sabatica autoimpuesta, dadas mis multiples tareas en muchos flancos a la vez.  Mis comunicaciones con mi hijo son mas frecuente ya que nos comunicamos por los chats, donde le he seguido desarrollando su habilidad para desarrollar patrones y dibujar en la computadora.  Por ejemplo, les incluyo dos imagenes demostrando lo facil que es desarrollar patrones en office.

El primer ejemplo es esencialmente un grupo de pentagonos girados y cambiados de colores.  El segundo es jugando con los efectos de letras, aunque la gallina asesina fue rellenando poligonos sencillos.

Obviamente ese no es el tema de hoy.  La obsesion mas reciente de mi hijo consiste en desarrollar patrones celtas y como buen padre le apunto direcciones que lo desarrollen, le gusta investigar las cosas que le dejo en el inbox.

Como estas:
http://www.elfwood.com/farp/theart/nooyknots/nooyknots.html
http://gwydir.demon.co.uk/jo/knots/index.htm

Que le ense/nan a dibujarlas a su nivel.  Tiene tal fiebre que esta forrando libretas con sus dise/nos.  Es mas, voy a poner par de muestras:





Dios Mio!  Si hubiesen inventado las computadoras para mi epoca la verdad que estuviese haciendo cada cosa!

Anyway, el tema es el Book of Kells.  El Book of Kells es considerado un clasico de los documentos ilustrados irlandeses.  Y lo curioso es la originalidad del trabajo que mezcla el rico arte folclorico irlandes con la norma catolica de la era.  Un poco de wikipedia:
http://en.wikipedia.org/wiki/Book_of_Kells

http://employees.oneonta.edu/farberas/arth/arth212/book_of_kells.html
http://youtu.be/SkAmCwEgsRE

Un libro realmente fascinante, como ilustra la coleccion de arriba.
El Chi Rho, representando el nombre del Chiristos, en alta resolucion:
http://www.uni-due.de/DI/Chi_Rho.htm

Sobre la historia, se hizo una version animada recientemente, la primera pelicula animada de largometraje irlandesa.  Aqui una escena presentando la invasion de la ciudad de Kells.  Animacion sencilla pero respetando el estilo de los folios y un gran timing.  Les dejo la escena:



Tiene un buen soundtrack con ritmos celtas new age:
Cierro con este curioso giro a la historia de la Caperucita Roja:

Thursday, July 12, 2012

[279] Curiosidades Web

Otro gran corto de Cartoon Brew http://www.cartoonbrew.com/shorts/all-consuming-love-man-in-a-cat-by-louis-hudson.html ...Twisted Ending.
Me recordo este video de Black Crowes Sigo en mil y un menesteres. Entre la residencia y mis labores me voy a desquiciar... Seguiremos informando.

Monday, July 2, 2012

[278] Trentemoller - Intermedio



seguire posteando luego.  sigo sumamente ocupado con multiples tareas.
Sigo super ocupado pero les dejo este video de Tom and Jerry. Este es particularmente cinico con el reloj, las escaleras al cielo y firmar un waiver para entrar al cielo.

Y creo que no explique el cinismo del ultimo video.  Estoy enfermo de facebook y su amistad sintetica.  Todo el mundo cree que postear una foto de un ni/no con sindrome de down o de una mujer sobreviviente de cancer los hace mejor persona.  Es en realidad pura hipocresia.  Pero no vale la pena ni mencionarlo.

Es mas, les dejo con Security, uno de mis albums favoritos de Peter Gabriel.  Link al disco completo aqui:
http://youtu.be/cYxvEvBkjfM
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