Sodium Vapour Lamp

Sodium Vapour Lamp consists of a discharge tube made from a heat resistant glass, containing a small amount of metallic sodium, neon gas and two electrodes, Neon gas is added to start the discharge and to develop enough heat to vaporize the sodium. Because of law pressure inside the tube, a sufficiently long tube required to obtain more light. To reduce the overall dimension of the lamp, this tube is generally bent into U-shape. The light produced by this lamp is yellowish which is produced at its optimum pressure of about 0.004mm of mercury. This pressure is obtained at a temperature of about 280 C and so it becomes necessary to maintain this temperature. For this purpose the U-tube is enclosed in a double walled flask to prevent lose of heat. The double walled flask is interchangeable and can be fitted on to another U-tube. While replacing the inner U-tube one must be very careful because if it is broken and sodium comes in contact with moisture, it may result in fire. All electric discharge lamps require a higher voltage at the time of starting and low voltage during operation. Generally, sodium vapour lamps are operated by a high leakage reactance transformer. At starting a high voltage of about 450 volts is applied across the lamp which is sufficient to start the discharge. When the lamp is fully operative after 10 - 15 minutes, the voltage across it falls to about 150 volts. Because of the high reactance of circuit, the power factor is low and hence a p.f improvement capacitor is connected. The efficiency of a low pressure sodium vapour lamp is very high (about 40 - 50 lumens/watt) and it produces a light of particular wavelength having yellow color. Sodium lamps are mainly employed for street, high way and airfield lighting where color distinction is not so necessary.

5 Quick Gardening Tips to Save You Money

It's easy to spend a fortune every year creating a beautiful yard. These five tips can help save you money in both this, and future gardening seasons.

1.) Plan your vegetable garden according to what your neighbors are planting so you can share your vegetables when they're ready for eating.

2.) Select perennials rather than annuals for your flowerbeds. As they multiply each year, cut them back and exchange with your friends so you both have lovely gardens and save money at the same time.

3.) Compost your kitchen scraps, as well as your coffee grounds. The end result is much better than any potting soil you can ever get buy from a nursery or hardware store. The price is right, and this is definitely recycling!

4.) Instead of using mulch, try pebbles or small rocks in your garden as ground cover. This will save you lots of cash since you won't need to buy mulch in the spring and fall of every year.

5.) Spend more money now by purchasing better quality gardening tools and you will save in the long run. They will last for years, saving you dollars because you don't need to replace them every planting season. The same goes for gardening gloves- make sure you buy the best you can afford so they last all season.

Chocolate: The Answer To Hydrogen Fuel Supplies?

Mention hydrogen as a fuel source and politicians, scientists and techies get that glassed over look in their eyes. Simply put, hydrogen is a perfect fuel. It can be combined with oxygen to produce electricity. Hydrogen is the most comment element on our planet. When used as an energy source, it produces no greenhouse gases or other pollutants. Sounds great, right? 

There is just one problem with the idea of using hydrogen as the solution to all of our energy problems. While hydrogen is the most common element on our planet, it is rarely found in a usable form. Instead, hydrogen tends to cling to other elements such as oxygen, which gives us H2O, water. The power required to separate hydrogen from these other elements is shockingly large.

In the United States, Honda has a number of hydrogen vehicles it is testing on the road via some families. The cars work well. Powering them, however, is the problem. The families must take the cars to a specific station at a Honda facility. There, they will find a few hundred feet of solar panels and a hydrogen tank. It takes the system roughly two to three weeks to create enough usable hydrogen for one full tank for the car. Given the fact there are millions of cars on the road, you can see the problem. Yes, there are more efficient methods for conversion than solar power, but nothing remotely efficient enough to create enough usable hydrogen.

In a humorous turn, scientists in the UK have discovered that hydrogen can be produced from the wastes of creating confectionaries such as chocolate. The waste is treated with e-coli bacteria. Yes, e-coli. The bacteria then process the food material and produces gas. Guess what kind of gas is produced? Yes, hydrogen.

Could it be that chocolate will play a fundamental role in a hydrogen fuel future? Could we really be that lucky?

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Grandfather Clocks

Among the most revered of all clocks are the majestic grandfather clocks that have been seen throughout older homes and also in places of high regal nature. These clocks have been replicated, but the replicas lack the history that has made the antique grandfather clocks so respected in most circles. These have been something that has been sought after by many collectors and people that have a strong attraction to antiques.

Many people have associated them with a link to their ancestors and this creates a desire to have one in their homes. They may have heard one of these antique grandfather clocks chiming the hours away when they visited their grandparents as a child. Owning one allows them to constantly relive those childhood memories.

One of the areas that most people don't think about when they get one is that they have special needs. They need to be wound up or have their chains pulled to keep the clock running. Some antique grandfather clocks that have been allowed to stop are a challenge to get the pendulum started as they are so old that the gears are tight.

Many that are still in use have usually been in a family for generations and are a reflection of the heritage of the people within the family. There are some people that have never gotten used to the ticking of the clock or the constant chiming that comes with one of these clocks. They tend to have their antique grandfather clocks at the opposite end of the house from the bedrooms to help make it possible for them to sleep.

This is something that many of the people of old may have been wise to as the most popular place for the clocks tended to be in the parlor or some form of formal room on the ground floor while the bedrooms were usually in the upper levels of the homes. This was not always the case, but many times this was the goal that was strived for when there was one of these antique grandfather clocks within the home.

Some individuals have held onto these huge pendulum clocks, yet have had to pay a pretty penny to have them moved and to be preserved. Many times a special person must be contacted to have the antique grandfather clocks maintained to help ensure that they are kept running and in a good state of condition.

Whether you have one in your home is strictly a matter of personal preference. What some families have done with antique grandfather clocks they have inherited is to display them without having them operational. This saves them having to worry about the noise or the cost of maintenance while allowing them the joy of sharing the beauty with their guests. It's a great compromise that is ideal for some.

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Growing Tomatoes

Though most people love to start growing their tomatoes from starter plants, they can be started early inside the house. This is the hard way to do it though, and the starter plants you can buy are much easier to deal with. Either way, they should be a certain size before planted outside or they may not grow correctly. These are easy to transplant, but they should be given a lot of space. Each plant will spread as they grow and they need room to get the sunlight they need. 

Though most like to have a large garden when growing tomatoes, it can be done in a window box for those who do not have a yard. This might mean only planting one or two plants, but they can still produce a good number of tomatoes for personal use. When growing tomatoes, they have to be watched very carefully. Then they reach a certain size they must be staked. This means a stake or a fence must be put near the plant to hold it up. It might very well grow up the fence. This keeps the tomatoes up out of the soil.

When growing tomatoes, a good fertilizer should be used to ensure the plants remain healthy and that the fruits grow as large as they can. Much like any other type of plant, they should be free from nearby growing weeds, and watered when necessary. Though some use to claim watering during the day would cause sun damage, this is not always true. If a person feels this might be a problem they can water the growing tomatoes after the sun goes down each night. Tomatoes do not have to be red before they are picked, but some prefer to let them ripen on the vine. They can be picked when they begin to turn yellow or orange and then brought in to ripen on the window sill. They taste better if they are not refrigerated.

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Life of Leonardo da Vinci

Leonardo da Vinci was a painter, sculptor, architect, cartographer, engineer, scientist and inventor in the 15th century. Yet, despite his genius, he referred to himself as "senza lettere" (the illiterate, the man without letters). Until late in life, he was unable to read, or write, Latin, the language used by virtually all other Renaissance intellectuals, the lingua franca, akin to English today. Nor was he acquainted with mathematics until he was 30.

Leonardo was born out of wedlock but was raised by his real father, a wealthy Florentine notary. He served at least ten years (1466-1476) as an apprentice to Andrea del Verrocchio and painted details in Verrocchio's canvasses. Only in 1478, when he was 26, did he become independent.

He was not off to an auspicious start. He never executed his first commission (an altarpiece in the chapel of the Palazzo Vecchio della Signoria, Florence's town hall). His first large paintings were left unfinished ("The Adoration of the Magi" and "Saint Jerome", both 1481). 

Most of the sketches and studies for Leonardo's works of art and engineering are found on his shopping lists, personal notes, and personal expenditure ledgers.

No one was allowed to enter Leonardo's den, where he kept, a number of green and other kinds of lizards, crickets, serpents, butterflies, locusts, hats, and various strange creatures of this nature.

Leonardo's clients were often dissatisfied with his glacial pace, lack of professional discipline, and inability to conclude his assignments. He was frequently involved in litigation. The Confraternity of the Immaculate Conception sued him when he failed to produce the Virgin on the Rocks, an altarpiece they commissioned from him in 1483. The court proceedings lasted 10 years. The head of Jesus in "The Last Supper" was left blank because Leonardo did not dare to paint a human model, nor did he trust his imagination sufficiently. Leonardo worked four years on the Mona Lisa but never completed it, either. He carried it with him wherever he went.

Leonardo's terra cota model for a colossal bronze sculpture of the father of his benefactor and employer, Ludovico Sforza, was used for target practice by invading French soldiers in 1499. The metal which was supposed to go into this work of art was molded into cannon balls.

Leonardo was a member of the commission which deliberated where to place Michelangelo's magnificent statue of David. His cartographic work was so ahead of its time, that the express highway from Florence to the sea - built in the 20th century - follows precisely the route of a canal he envisioned. His scientific investigations - in anatomy, hydraulics, mechanics, ornithology, botany - are considered valuable to this very day. Bill Gates owns some his notebooks containing scientific data and observations (known as the Codex Hammer).

But Leonardo's loyalties were fickle. He switched sides to the conquering French and in 1506 returned to Milan to work for its French governor, Charles D'Amboise. Later, he became court painter for King Louis XII of France who, at the time, resided in Milan. In 1516, he relocated to France, to serve King Francis I and there he died.

Leonardo summed up the lessons of his art in a series of missives to his students, probably in Milan. These were later (1542) collected by his close associate, Francesco Melzi, as "A Treatise on Painting" and published in print (1651, 1817).

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Conservation In Your Life

Perhaps one of our societies biggest downfalls, is that we are wasteful. Incredibly wasteful actually. Our lives are spent wasting time, energy, and emotion on people and activities that do nothing for us. Everyone is guilty of wasting, and therefore everyone needs to add an important concept to many areas of their life: conservation.

Our first thoughts about conservation probably take us to picturing a rain forest somewhere in the jungle whose trees are being quickly cut down, or to a village in Africa whose meager water supply is wasted on unnecessary things. These are both situations that could rightly learn from the concept of conservation.

Any true change in the world will only happen when individuals start to change their own lives. So let's begin thinking about conservation as it relates only to our individual lives. Think about the most valuable resources you have at your disposal. Some of the most valuable resources we have are time, energy, mind, and health. It is only as we begin to see our lives as full of natural resource that we can begin the process of conservation and protection of these resources.

If time is one our greatest assets, then we must think about the ways you spend or use that resource. We can practice conservation by looking for ways to use our time more efficiently and wisely. We must also look for ways to practice conservation of our energy. This can be done by taking time for exercise, proper sleep, and relaxing activities. The great resource of the mind needs to be conserved by taking time to enrich it through reading, studying and even writing. We should consider your most valuable resources and look for ways to practice the conservation of each of them.

When you are committed to practicing conservation in your own life, you can begin to look outside yourself and see resources in your neighborhood or city that can be conserved as well.

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