dimarts, 24 de febrer del 2009
MARQUETRY SAW
Marquetry saw is a tool whose function is to cut or saw, mainly wood or plywood, but is also used for cutting sheet metal or even plaster moldings.
In the mountains of arc using manual and mechanical cutting action alternative in the leaf, which is mounted to toggle (reciprocate) in a horizontal plane. The movement is cut perpendicular to the plane of the workpiece, which is mounted in a vise. The breakthrough occurs with the vertical motion of the saw blade arc, with hydraulic or mechanical.
It's called hand saw to cut a hand tool which is composed of two distinct elements. Is a part of the arch or frame which is fixed by screws tensors the saw blade and the other part is the saw blade provided by the court.
Solar energy is the radiant light and heat from the Sun that has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation along with secondary solar resources such as wind and wave power, hydroelectricity and biomass account for most of the available renewable energy on Earth. Only a minuscule fraction of the available solar energy is used.
Solar power technologies provide electrical generation by means of heat engines or photovoltaics. Once converted its uses are only limited by human ingenuity. A partial list of solar applications includes space heating and cooling through solar architecture, potable water via distillation and disinfection, daylighting, hot water, thermal energy for cooking, and high temperature process heat for industrial purposes.
Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute sunlight. Active solar techniques include the use of photovoltaic panels, solar thermal collectors, with electrical or mechanical equipment, to convert sunlight into useful outputs. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.
dilluns, 16 de febrer del 2009
A good place for a holiday
My First Day of Secondary School
I only knew some students in the class. I waited for the group list opposite the door.We are walked into to the theatre, there we listened the headteacher. Then the teacher gave us the time table.The morning was very short.
dimecres, 4 de febrer del 2009
Charles Darwin
At Edinburgh University Darwin neglected medica.
l studies to investigate marine invertebrates, then the University of Cambridge encouraged a passion for natural science.
He was writing up his theory in 1858 when Alfred Russel Wallace sent him an essay which described the same idea, prompting immediate joint publication of both of their theories.
When the Beagle returned on 2 October 1836, Darwin was already a celebrity in scientific circles as in December 1835 Henslow had fostered his former pupil’s reputation by giving selected naturalists a pamphlet of Darwin’s geological letters. Darwin visited his home in Shrewsbury and saw relatives, then hurried to Cambridge to see Henslow, who advised on finding naturalists available to catalogue the collections and agreed to take on the botanical specimens. Darwin’s father organised investments, enabling his son to be a self-funded gentleman scientist, and an excited Darwin went round the London institutions being fêted and seeking experts to describe the collections. Zoologists had a huge backlog of work, and there was a danger of specimens just being left in storage.
Charles Lyell eagerly met Darwin for the first time on 29 October and soon introduced him to the up-and-coming anatomist Richard Owen, who had the facilities of the Royal College of Surgeons to work on the fossil bones collected by Darwin. Owen’s surprising results included gigantic extinct sloths, a near complete skeleton of the unknown Scelidotherium and a hippopotamus-sized rodent-like skull named Toxodon resembling a giant capybara. The armour fragments were from the Glyptodon, a huge armadillo as Darwin had initially thought. These extinct creatures were closely related to living species in South America.
dilluns, 2 de febrer del 2009
My diary
On Monday I get up at half past seven. I have breakfast and go to school. At a quarter to two I have lunch. In the evening I go training table tennis. I study at five.
On Tuesday I get up at half past seven and go to school. At a quarter to two I have lunch. In the evening I study at six o'clock and at seven I training table tennis.
On Friday I get up at half past seven and go to school. I go to breakfast and go to school. At a quarter to two I have lunch. I study at five.
On Thursday I get up half past seven and go to school. At a quarter to two I have lunch. In the evening I study at six and at seven I go to trainer at table tennis.
On Friday I up to the bed and go to school. At a quarter to two I have lunch. I study at five.
On Saturday I up to the bed. I go to breakfast. At a quarter to two I have lunch. I play to table tennis at five.
On Sunday I up to the bed. I go to breakfast. At a quarter to two I have lunch. I play to table tennis at ten. In the evening I do my homework and study.