hi!

Sports day

2008-02-04T00:05:00.000-08:00

Sports day is round the corner. It is on Valentine's day, 14 February. Sports day is a meaningful and is a event to let pupils to show off their sports talents, for example like, running and others.
Well, for me, I am going for the 4 x 100 run event. That is my second time to run for the event. I did not run for last year as I am injured. Never mind, I will just try to win.

The Mighty Sun

2007-09-23T22:49:00.000-07:00

The Sun

The Sun is the star at the center of the Solar System. The Earth and other matter (including other planets, asteroids, meteoroids, comets and dust) orbit the Sun, which by itself accounts for about 99.8% of the solar system's mass. Energy from the Sun—in the form of sunlight—supports almost all life on Earth via photosynthesis, and drives the Earth's climate and weather.

The Sun is composed of hydrogen (about 74% of its mass, or 92% of its volume), helium (about 25% of mass, 7% of volume), and trace quantities of other elements. The Sun has a spectral class of G2V. G2 implies that it has a surface temperature of approximately 5,780 K (or approximately 5,515 degrees Celsius / 9,940 Fahrenheit), giving it a white color which, because of atmospheric scattering, appears yellow as seen from the surface of the Earth. This is a subtractive effect, as the preferential scattering of blue photons (causing the sky color) removes enough blue light to leave a residual reddishness that is perceived as yellow. (When low enough in the sky, the Sun appears orange or red, due to this scattering.)

Its spectrum contains lines of ionized and neutral metals as well as very weak hydrogen lines. The V (Roman five) suffix indicates that the Sun, like most stars, is a main sequence star. This means that it generates its energy by nuclear fusion of hydrogen nuclei into helium and is in a state of hydrostatic equilibrium, neither contracting nor expanding over time. There are more than 100 million G2 class stars in our galaxy. Because of logarithmic size distribution, the Sun is actually brighter than 85% of the stars in the galaxy, most of which are red dwarfs.[1]

The Sun orbits the center of the Milky Way galaxy at a distance of approximately 26,000 light-years from the galactic center, completing one revolution in about 225–250 million years. The orbital speed is 217 km/s (135 mi/s), equivalent to one light-year every 1,400 years, and one AU every 8 days.[2]

It is currently travelling through the Local Interstellar Cloud in the low-density Local Bubble zone of diffuse high-temperature gas, in the inner rim of the Orion Arm of the Milky Way Galaxy, between the larger Perseus and Sagittarius arms of the galaxy. Of the 50 nearest stellar systems within 17 light years from the Earth, the sun ranks 4th in absolute magnitude as a fourth magnitude star (M=4.83).

we can use solar power

2007-08-19T23:23:00.000-07:00

Solar power
Solar power (also known as solar energy) uses Solar Radiation emitted from our sun. Solar power, a renewable energy source, has been used in many traditional technologies for centuries, and is in widespread use where other power supplies are absent, such as in remote locations and in space.
Solar radiation reaches the Earth's upper atmosphere at a rate of 1366 watts.
Solar radiation is reflected and 16% is absorbed resulting in a peak irradiance at the equator of 1,020 W/m².[2] Average atmospheric conditions (clouds, dust, pollutants) further reduce insolation by 20% through reflection and 3% through absorption.[3] Atmospheric conditions not only reduce the quantity of insolation reaching the Earth's surface but also affect the quality of insolation by diffusing incoming light and altering its spectrum.
After passing through the Earth's atmosphere, most of the sun's energy is in the form of visible and Infrared radiations. Plants use solar energy to create chemical energy through photosynthesis. Humans regularly use this energy burning wood or fossil fuels, or when simply eating the plants.
A recent concern is global dimming, an effect of pollution that is allowing less sunlight to reach the Earth's surface. It is intricately linked with pollution particles and global warming, and it is mostly of concern for issues of global climate change, but is also of concern to proponents of solar power because of the existing and potential future decreases in available solar energy. The order of magnitude is about 4% less solar energy available at sea level over the timeframe of 1961–90, mostly from increased reflection from clouds back into outer space.
Many technologies have been developed to make use of solar radiation. Some of these technologies make direct use of the solar energy (e.g. to provide light, heat, etc.), while others produce electricity.
Solar design in architecture involves the use of appropriate solar technologies to maintain a building’s environment at a comfortable temperature through the sun's daily and annual cycles. It may do this by storing solar energy as heat in the walls of a building, which then acts to heat the building at night. Another approach is to keep the interior cool during a hot day by designing in natural convection through the building’s interior.

Solar hot water systems use sunlight to heat water. Solar hot water systems were used extensively in the United States up to the 1920s until replaced by relatively cheap and more reliable conventional heating fuels. The economic advantage of conventional heating fuels has varied over time resulting in periodic interest in solar hot water; however, solar hot water and heating technologies have yet to show the sustained momentum they lost in the 1920s. That being said, the recent spikes and erratic availability of conventional fuels has resulted in a renewed interest in solar heating technologies.
On a technical level, solar water heating is particularly appropriate for low temperature applications (100-150F). This advantage has been successfully applied to heating swimming pools where solar water heating can economically increase pool use. Solar water heating is also used in stand alone or hybrid domestic water heating systems. Solar cells, also referred to as photovoltaic cells, are devices or banks of devices that use the photovoltaic effect of semiconductors to generate electricity directly from sunlight. Until recently, their use has been limited because of high manufacturing costs. One cost effective use has been in very low-power devices such as calculators with LCDs. Another use has been in remote applications such as roadside emergency telephones, remote sensing, cathodic protection of pipe lines, and limited "off grid" home power applications. A third use has been in powering orbiting satellites and spacecraft.
To take advantage of the incoming electromagnetic radiation from the sun, solar panels can be attached to each house or building. The panels should be mounted perpendicular to the arc of the sun to maximize usefulness. The easiest way to use this electricity is by connecting the solar panels to a grid tie inverter. However, these solar panels may also be used to charge batteries or other energy storage device. Solar panels produce more power during summer months because they receive more sunlight. The cost payback time may take over 10 years depending on the cost of grid electricity and tax rebates.
Total peak power of installed PV is around 3,700 MW as of the end of 2005. This is only one part of solar-generated electric power.
Declining manufacturing costs (dropping at 3 to 5% a year in recent years) are expanding the range of cost-effective uses. The average lowest retail cost of a large photovoltaic array declined from $7.50 to $4 per watt between 1990 and 2005. With many jurisdictions now giving tax and rebate incentives, solar electric power can now pay for itself in five to ten years in many places. "Grid-connected" systems - those systems that use an inverter to connect to the utility grid instead of relying on batteries - now make up the largest part of the market.
In 2003, worldwide production of solar cells increased by 32%.Between 2000 and 2004, the increase in worldwide solar energy capacity was an annualized 60%. 2005 was expected to see large growth again, but shortages of refined silicon have been hampering production worldwide since late 2004. Analysts have predicted similar supply problems for 2006 and 2007。
The first solar "cars" were actually tricycles or quadricycles built with bicycle technology. The solar array consists of hundreds of photovoltaic solar cells converting sunlight into electricity. The cells are wired together into strings while strings are often wired together to form a panel. Panels normally have voltages close to the nominal battery voltage. The main aim is to get as many cells in as small a space as possible. Designers encapsulate the cells to protect them from the weather and breakage.
Designing a solar array is more than just stringing bunch of cells together. A solar array acts like a lot of very small batteries all hooked together in series. The total voltage produced is the sum of all cell voltages. The problem is that if a single cell is in shadow it acts like a diode, blocking the flow of current for the entire string of cells. To correct against this, array designers use by-pass diodes in parallel with smaller segments of the string of cells, allowing current to flow around the non-functioning cell(s). Another consideration is that the battery itself can force current backwards through the array unless there are blocking diodes put at the end of each panel.
The power produced by the solar array depends on the weather conditions, the position of the sun and the capacity of the array. At noon on a bright day, a good array can produce over 2 kilowatts (2.6 hp).Some cars have employed free standing or integrated sails to harness wind energy.

Short description of me

2007-08-13T02:54:00.000-07:00

My name is Wu Shao Yang.I am studying in Rulang ,class 5U.My teacher is Mr Loo .As I said before,he is not fierce at all.Friends around me are very kind and helpful.Now I am playing piano,grade 6.

Our School Logo

2007-08-13T02:47:00.000-07:00

This is our school logo.Very Nice is't it?

About Rulang

2007-08-13T02:19:00.000-07:00

Rulang Primary School was founded in a shophouses, Jurong Road in year 1930 with Yak Woh Hoon as the head of the school. Rulang Primary was originally known as Joo Long Public School, before it was 'pinyinized' to 'Rulang' when the school converted into a government school in year 1984. Our school stood through the Japanese Occupation, though lessons were suspended then. A new school was built at Upper Jurong Road in year 1950. Our school was given new facilities in year 1985, and then upgraded under the Programme for Rebuilding and Existing schools (PRIME) in year 2003.
It is currently headed by Mrs Cheryl Lim as the principal of our school.

Things you can do to RELAX

2007-08-13T00:03:00.000-07:00

The List: sleeping
swimming
reading
computer games... ...maybe
snacking
play piano... ... if you learn piano and you have the piano
drawing
play basketball... ...if you have basketball
movies
ice-skating
play soccer