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 Garzone (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, as Giorgio Vasari in “Lives of the Artists”, describes: “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 Cofraternity 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).

Life of Leonardo da Vinci is a post from: Reference Education Center

STAGE 1 – MINING
The diamonds that made it to the surface were forced up volcanically, through kimberlite pipes. A typical pipe mine consists of a large vertical shaft with tunnels running from the main pipe. The deepest mine runs about 3,500 feet down into the earth. More than 200 tons of rock, gravel and sand need to be blasted, crushed and processed to yield just one carat of gem quality diamonds. Finding diamonds and getting them out of the ground may require the use of jet engines to thaw the frozen ground or to endure the sweltering desert heat. Only about 20% of all rough diamonds are suitable for polishing; the rest are used for industrial purposes. Once the rough is found the diamond’s journey begins.

STAGE 2 – ROUGH REACHES THE MARKET
A large proportion of the world’s rough supply finds its way to De Beers’ Central Selling Organization (CSO). The rough the CSO buys is sorted into more than 5,000 different categories. Once the rough is sorted and priced, it is sold to manufacturers at sights. There are ten sights a year, each lasting a week. The chosen few afforded the chance to purchase at these sights are called sight holders. The balance of the world’s rough supply is sold to private buyers, and some through private auctions.

STAGE 3 – MANUFACTURING THE DIAMOND
Regardless of the source, all rough eventually finds its way to the cutting centers. Today, the major cutting centers are Antwerp, Israel, Bombay, Johannesburg, and New York. Upon reaching its destination the rough is carefully examined to decide how it should be cut to yield the greatest value. After the stone’s shape and size are determined, taking into consideration the rough’s shape, as well as the number and position of its internal inclusions, the stone is marked and usually sawed or cleaved.
The stone then goes through a series of cutters who each have their own specialty. Finally the diamond is polished and ready for sale.

STAGE 4 – THE FINAL JOURNEY
After a diamond is manufactured it needs to be sold. For decades diamond manufacturers have sold their cut diamonds to jewelry manufacturers and diamond wholesalers who in turn, sell to jewelry wholesalers and to retail jewelry stores. Today’s technology is changing the diamond pipeline. Diamond manufacturers now have a direct link to the final customer.

By learning the 4C’s and buying only certified diamonds it is possible to purchase the same quality diamond for a significantly lower price, over the internet.

Learn More about Diamonds is a post from: Reference Education Center

I haven’t honestly thought that much about earth science since I took a class in it in junior high school. At that time I hated everything to do with science and so I didn’t give much thought one way or another to earth science. I dreadfully made it through that class learning only the basics enough to get by (not the least of which I can remember now).

I’m not quite sure what inspired me to attempt to discover facts about earth science. I guess I began to become more interested in earth science as I had children and they grew up asking question after question. I could barely take them on walks at night without them asking me questions about the ground, the soil, the trees or the sun. I would fumble through answers and try to change the subject quickly as I admitted to myself that I really did not know much. So on my next trip to the library I picked up a few general books on earth science and began learning with my kids.

I have found that learning with my kids has become one of the best ways to grow in knowledge. I utilize their curiosity and take every chance I can at learning with them. It has been a great way for me to learn more about earth science and other things. I never knew how much motherhood would affect me, but I certainly didn’t know how much I would learn because of my children’s hunger for knowledge.

I have learned many things about earth science since our studies have begun. One of the biggest things I have learned is a deeper sense of appreciation for the world I live in. I have grown in amazement and wonder about the way the world works and about my small and insignificant place. I simply am astounded by the intricacies and details of our earth. Earth science has made me even more curious about the world around me.

If you have a craving to learn more about the world you live in, then start with grabbing a few books on earth science. You’ll love learning so much that you won’t be able to stop.

Learn From Earth Science is a post from: Reference Education Center

Over the centuries as organic matter is converted to coal, methane, also known as CH4 and the primary constituent in natural gas, is produced during this process and stored in pockets within a coal seam. For every ton of coal produced, during the coalification process, more than 5000 cubic feet of methane is created. Coal mining releases this methane into the atmosphere. Over 90 percent of methane emissions come from underground coal mining. Because gas content is greater with depth, safety hazards increase during the underground coal mining process. Degasifying coal mines has been proven to help make those underground coal mines safer for miners.

Volatile gases produced during the coal mining process reportedly kill more than 15 miners every day in China, about 80 percent of the worlds coal mining deaths. Prime Minister Wen Jiabao, a mining engineer by training, has demanded China improve conditions for Chinese coal miners. Critics, such as the Chinaworker.org, say the underlying cause is a lack of investment in degasification equipment. The website claims, Managers calculate that its cheaper to pay out meager death benefits to miners families than (to) raise investment. The Economist magazine reported that Chinese coal miners make as little as $60/monthly.

China is also concerned about its air emissions from coal mining. Worldwide, the coal mining industry released over 436 million metric tons of carbon dioxide equivalents in 2000. That accounted for about 8 percent of the total industrial methane emissions that year. China, Russia, Poland and the United States account for over 77 percent of coal mining methane emissions. Through the year 2020, Chinas share of worldwide emissions will jump to 45 percent. These emissions could be severely reduced if Chinese coal mines captured the methane gas for use in meeting its soaring energy needs, rather than vented into the atmosphere each time a new coal tunnel is opened.

One of the major draws at the Guiyang Pre-Mining Degasification Symposium were presentations about the latest coalbed methane drilling innovation by Tunaye Sai, Director of China Operations for Pacific Asia China Energy (TSX: PCE; Other OTC: PCEEF), and Nathan Mitchell of Mitchell Drilling Company (MDC) in Brisbane, Australia. Coal mining companies opened discussions with PCE after their presentation. Executives from fifty mines showed interest in the Dymaxion drilling technology to improve mining safety, said Tunaye Sai. All of them showed interest? All of them, responded Tunaye Sai. PCE reported in a news release on Wednesday, The PACE-MDC joint venture group is currently preparing a business plan for the immediate development of this new strategy in order to address the demand, which arose from the attendees at this symposium.

They are having problems in their mines, explained Tunaye Sai, who is also a member of the Canadian Institute of Mining, Metallurgy and Petroleum. Because they have not been able to effectively degasify their mines, four of the attending Chinese coal mining companies immediately approached Tunaye Sai and Mitchell about using this state-of-the-art drilling technology. Earlier this year, PCE and MDC announced they were forming a joint venture to offer MDCs proprietary Dymaxion drilling technology to companies in China, to help degasify their coal mines. MDC is Australias largest privately owned drilling company, and their Dymaxion technology has been widely discussed by coal mining insiders. The PCE and MDC joint venture company has the exclusive rights to use the Dymaxion technology in China.

In a tape-recorded interview, Tunaye Sai told StockInterview, The combination of a horizontal and vertical intersection draws the methane gas from the coal seam and captures it at the surface. Australian newspapers have been exuberant over the Dymaxion technique, calling it revolutionary and radical. In its headline, one Australian newspaper called MDCs state-of-the-art G-55 drill rig the Lamborghini of drill rigs, and remarked how their drill rigs offered improved flexibility and cost efficiency.

The Dymaxion surface to in-seam (SIS) drilling method uses modified multipurpose mineral drill rigs, specially designed bottom-hole assemblies and specially trained personnel. The technique involves drilling a 60 to 90 degree hole from the surface and steering it through a medium radius bend to enter the target coal seam horizontally. The 96mm hole is then steered for up to 1200 meters in the seam towards a previously drilled vertical production well. A homing device, lowered down the vertical well to the target seam, aids the intersection with the vertical well. The vertical well is also equipped with a suitable pump to dewater the seam. After the hydrostatic head has been sufficiently lowered, the methane gas will flow to the surface. Newspaper reports also say this technique allows for significant savings over alternate underground gas drainage drilling methods.

The Dymaxion technology obviously turned heads at the recent Gasification Symposium. One of the companies is a big company, mining 10 million tons of coal per year, said Tunaye Sai. Last December, 12 people died in one of the coal mining companys tunnels. He explained that when coal miners are opening a tunnel, the gas comes out sometimes explosively. By using the Dymaxion technique, they can let the gas out before they begin mining a tunnel, he added.

Discussions with the Chinese coal companies are in the initial stages. They want to give us a block not one that is being mined now, but one that may be mined in a few years, said Tunaye Sai. Were working on an arrangement right now because they are very interested. He explained that the relationship would involve a continuous process. We wouldnt just drill it and then abandon it, he added. We will be making sure that the gas will come out continuously and monitoring it.

Tunaye Sai said that Pacific Asia China Energy was targeting the larger mines. Among them, about ten companies mine about four million tons per year or more. Those are the ones we are talking to. PCE has ordered the drilling equipment, and it should arrive in China around October. As soon as it is there, we can implement our plan, maybe in November or December. He told us, They have been asking us to demonstrate the equipment for them. This may be an unexpected revenue surprise for Pacific Asia China Energy, and a blessing for Chinese coal miners whose lives may be spared, thanks to this latest technology transfer to China.

Latest Technology Transfer Could Reduce Chinese Coal Mining Deaths is a post from: Reference Education Center

Undercorrection this occurs when the expected vision correction falls short of the desired outcome. This occurs more commonly with patients who have a high degree of nearsightedness (only objects close up are clear), farsightedness (only objects far away are clear) or astigmatism (images both far and near are distorted). Why? There is more laser corneal sculpting that needs to occur with patients having higher degrees of vision imperfection. When choosing your Lasik eye surgeon, its important to ask them what percentage of their patients need retreatment for undercorrection. This should be something that they are willing to freely discuss with you. If not, walk away! This is not to be confused with a planned slight undercorrection for nearsighted patients over forty years old which aids their reading vision. But this is something that you and your Lasik eye surgeon would have discussed before your surgery.

Overcorrection this complication occurs less frequently than undercorrection and results when the amount of correction (corneal laser sculpting) exceeds what is planned. Slight overcorrection can be temporary and may resolve itself in the first month following Lasik eye surgery. Patients can manage slight overcorrections by wearing glasses until their vision resolves. Some patients with overcorrection may need additional Lasik eye surgery 3 to 6 months following their first surgery.

Dry Eye many Lasik eye surgery patients may experience the feeling of grittiness in their eyes following surgery. This condition usually resolves itself in 3 to 6 months and may be helped by using lubricating eye drops. Patients using birth control pills and patients going through menopause may experience this condition more often. If dry eye continues beyond 6 months, your Lasik eye surgeon may recommend blocking your tear ducts with tiny silicon plugs to prevent tears from draining away too quickly.

Corneal abrasion a small percentage of Lasik eye surgery patients may develop a small corneal abrasion (scrape) caused by the microkeratome (instrument used to create corneal flap) used during surgery. This abrasion is generally not serious and will heal quickly. Your Lasik eye surgeon may temporarily place a thin bandage contact lens on your eye to promote healing. While your abrasion is healing, your vision will be blurry.

Night glare this annoying condition may not affect your vision clarity but patients may see halos or ghosting of images at night during the first month following surgery. Night glare generally improves in 3 months and often disappears within 6 months. Patients with large pupils and more severe vision impairment may be more prone to night glare.

Corneal flap complication this occurs when the corneal flap is too small, too thin or is an irregular shape. In some cases the corneal flap may shift slightly following surgery if a patient rubs their eyes during the first 6 hours after surgery. If the flap does shift, wrinkles can form causing distorted vision. A second procedure may be necessary to smooth out the wrinkles and improve vision.

Infection although this is the most feared complication of Lasik eye surgery patients, it is extremely rare. If your eye is going to become infected, chances are it will happen in the first 72 hours following surgery and will be treated with antibiotic eye drops. For this reason it is very important to avoid eye makeup, hot tubs and swimming pools for at least the first week following Lasik eye surgery.

The risks of Lasik eye surgery are low with an experienced Lasik eye surgeon but you need to be aware of possible complications prior to surgery. Your Lasik eye surgeon should freely discuss all possible complications of Lasik eye surgery prior to surgery. Do everything you can to put your eyes in the best possible hands.

Lasik Eye Surgery Complications is a post from: Reference Education Center

LASIK is a method of refractive surgery that is a regular procedure, often used for treating nearsightedness. Its popularity is due to the improvement of vision, without the major side effects that other eye surgery methods may produce.

With the eye being one of the most sensitive areas of the body, it might be somewhat surprising to learn that the LASIK procedure is relatively simple. In fact it’s not uncommon for those patients that have undergone the procedure to be working again the following day.

The eye is firstly washed out with a solution to numb the area. The next step is to hold the eyelids open using clamps. This will prevent blinking. After the solution begins to take effect, the surgeon will make an incision in the cornea. Once enough tissue is removed using the laser, the surgeon can then close where the incision is made, and the procedure is complete.

The benefits of LASIK eye surgery is there for all to see (excuse the pun!). Thousands of people have undergone the procedure, but for some the apprehension to go through with eye surgery may be attributed to the main benefits not being made clear, which are mainly two-fold:

1) The possibility to live life without the need for glasses or contact lenses.

2) An increase in the quality of vision.

The cost of having LASIK eye surgery performed can vary. The price depends on factors such as the equipment used for the surgery and also the testing carried out before the procedure. You may find that different providers will perform different levels of testing, so ensure that you research into different providers and find out what is included in the price. Of course you cannot put a price on your vision, but there is certainly no harm in discovering which provider offers the required features in the quoted price. One point that must be considered though is to find a surgeon that has experience with the procedure. Do not simply opt for the cheapest as they may not necessarily be the best.

LASIK Eye Surgery and the Benefits of the Procedure is a post from: Reference Education Center

The sun power that is used to operate a solar charger is a great way for people at the beach to keep their electrical devices running. Because solar chargers are meant to be used outside, they are naturally waterproof. They are made to withstand rain and other natural weather that may occur around them.

Weatherproof solar chargers are easy to find, the actual concern is more for the devices you are going to be charging with your solar energy charger. Most electrical devices that you will be charging with your charger are not weatherproof or waterproof at all. So even though your solar charger may be able to withstand a little water being splashed on it, that does not mean that your cell phone will be equally capable of operating in those watery conditions.

It is extremely important to keep all your electrical devices out of any water. Most devices will be ruined with very little water coming into contact with them. For those people who like to use their solar chargers at the beach, this can present a huge dilemma. They want to use a solar charger while relaxing at the beach, but they do not want to risk ruining their expensive electrical devices.

A simple solution is to remain far enough away from the water that you will not risk getting your device wet. You can also use an umbrella or other shading device to keep your electronics out of the weather in case it suddenly starts to rain. Just remember if you are using an umbrella to make sure and put your solar charger in the sunlight. If your charger is not in full sunlight, it will take much longer to charger your batteries or other devices.

Another solution for people who are afraid of water getting to their electrical devices is that they can put them in a plastic bag and only have the cord of the solar charger coming in through a small opening. This will protect the electronic device while still allowing it to be charged. This is a great option for sitting around the pool or at the beach. If the weather gets really bad, you should consider just packing everything up and heading for cover.

Solar chargers are very durable and can withstand most weather related conditions. It may still be necessary to remove your portable solar chargers from the weather if it is very stormy or windy out. A little rain should not bother them. Just make sure you have taken care of the devices you were charging because they are much more susceptible to rain and water damage than a solar charger is.

Is There a Waterproof Solar Charger? is a post from: Reference Education Center

However, when President Bush introduced The Biofuels Initiative during his 2006 state of the nation address, he moved this native prairie grass use as an energy crop to the forefront.

The Biofuels Initiative is a critical part of the presidents advanced energy initiatives. It seeks to reduce the countrys dependence on foreign oil suppliers by more than 75% of oil imports by 2025.

The aim is to accomplish this with the use of non-food based biomass, such as agricultural waste, trees, forest residues, and perennial grasses specifically switchgrass to produce energy fuels.

When distilled switchgrass produces ethanol, an alcohol that fuels vehicles. Currently ethanol is blended at a ratio of 15 percent to 85 percent of gasoline and sold as E-85.

Switchgrass or Tall Panic Grass is a short rhizomatous plant. It is highly adaptable for it can be planted in different parts of the country of varying climate conditions. It is also drought resistant.

From planting to care and harvesting, it costs less energy to produce biofuel from switchgrass.

Harvest semi-annually
Switch is a perennial crop, which means it can be harvested twice a year for close to 10 years, before the crop has to be replanted. It also grows fast, absorbs the solar energy, and turns this energy into cellulose. Ethanol is extracted from the cellulose by means of distillation.

High yield per acre
Results from among 19 BFDP (Bioenergy Feedstock Development Program) research sites on both the Eastern and Central United States have shown that switchgrass can be harvested at 15 tons an acre. When distilled into ethanol, this yields 1,500 gallons of ethanol an acre. When averaged on a six-year basis, this means a yield of 115,000 of gallons of ethanol from each acre.

Cost efficient
Results from a study undertaken by the University of California Berkeley, has found out that it takes more energy to produce gasoline than it does to produce ethanol.

Multiple uses
Expected advances in gasification technologies will yield other useful fuels: diesel fuel, methane gas, and methanol.

Environmentally Friendly
Switchgrass poses no danger to the soils fertility as it even adds organic matter.

Switchgrass has an intricate system of stems and roots. This system reaches into the deeper parts of the soil to hold on to it, stopping soil erosion.

Switchgrass are reliable buffers. Farmers plant these grasses along wetlands and steambanks to filter out pesticides and to prevent these dangerous chemicals from entering the water supply.

Switchgrass removes carbon dioxide (CO2) from the air and puts these back in the soil. Fossil fuels, on the other hand release huge amounts of CO2 into the atmosphere, increasing air pollution and worsening the greenhouse gas effects.

Financially rewarding
It costs less to grow switchgrass. When you add government tax incentives and grants raising switchgrass will be as profitable as extracting fossil fuels.

These are the present disadvantages of using switchgrass as the main source of biofuels.

The need to improve pretreatment technologies
Current technologies are not efficient in extracting higher yields from switchgrass. R&D efforts should correct this.

The need to allocate land for switchgrass
Is there available agricultural land to plant switchgrass? A system must be set in place to ensure there is land for both switchgrass and food crops.

The use of switchgrass as an energy crop is decidedly viable from the economic, production, and environmental aspects.

However, the success of switchgrass as an energy crop will depend on these key factors: government policies and funding, R&D efforts, technological innovations and vehicle efficiency.

Is Switchgrass a Viable Energy Crop? is a post from: Reference Education Center

All in all, we must accept the fact that we will not be able to have our gas and eat our corn muffins too. There are also other crops which can be used to derive the Ethanol fuel, such as soybeans, sugar beet, raw sugarcane, etc.. The fact still remains…the choice will be gas for our automobiles and along with this will eventually come a vast depletion of one or more of our key domestic and export crops. It does not mean that this scenario will eventually come to be, but without other renewable energy fuels developed in tandem, such as the Hydrogen based fuel cell to assist the Ethanol fuel approach, this could lend itself to some key food staple shortages. The final question may be…”Do we prefer wheels beneath
our feet, or food in our stomachs.” Common sense tells us that at this point in time, we must proceed with great caution. Granted, the very large south American country of Brazil has embarked on their Ethanol program for approximately a decade now, with fairly good results and have enjoyed the weaning from foreign oil. Will it ever be 100% remains to be seen.

Solar energy is one possible approach being tinkered with to produce Hydrogen in order to power our future power plants and it is hoped that electricity, which now helps to deplete our fossil fuels will help us to deliver the fuel needed to produce power for advanced “Fuel Cells” being developed to power the automobiles and trucks, etc. of the future.
Unfortunately, producing Hydrogen by using solar energy electricity is very inefficient. This being said, solar energy is fully renewable and therefore must be considered. Along with the Hydrogen fuel from Solar approach comes recent announcements of some breakthroughs holding great promise using Solar to economically produce the hydrogen needed for fuel cells for both the automobile and our industrial needs and not using up all of our food resources in the process.

Is Solar Power The Immediate Answer To Our Energy Woes ? is a post from: Reference Education Center

Is Passive Solar A Viable Home Heating Option In Cold Areas?

Passive solar can be used to heat a home in colder areas, but you have to go into it with reasonable expectations. While the cold climate is a hurdle, the real issue is going to be the length of time the sun beats down upon your property. If your home receives only four or five hours of direct sunlight a day, forget it. You will never produce enough energy to keep the home warm for sufficient periods of time.

Passive solar design is very popular in warm to mild climates because it is more or less a free method for warming a home. The manipulation of the position of the home and placement of large windows in the south facing wall is typical strategies for dealing with the issue. Obviously, large windows in a cold climate are going to result in significant heat loss regardless of the quality with which they are built. So, what can you do?

There are two primary approaches to creating a passive solar design that works in the winter. One is the use of a large Trombe Wall and the other is the greenhouse approach. Lets take a look.

Trombe Walls are popular in passive solar designs because they effectively convert sunlight to heat and are interesting from an aesthetic view point. Typically, a Trombe Wall is 8 to 12 feet in length on the south facing wall of a home. In significantly colder areas, the wall is going to need to be much larger, perhaps the full length of the home depending upon energy analysis and the cold weather expected. An energy audit of the home is the only to arrive at a definitive answer.

You are also going to have to incorporate a flip strategy for the heat. As the sun enters the glass plate and heats up the masonry of the wall, you risk losing vast amounts of it through the glass surface. This means you need to create an air circulation method whereby you draw the hot air into a secondary space behind the wall. This can simply be a closed off room or a space intended for the purpose. The circulation should be done on a timer similar to the solar thermostats used on solar hot water panels. The point is to keep the built up heat from escaping back into the environment.

The greenhouse approach simplifies matters. The essential idea is to build an insulated greenhouse to collect and store the heat of the sun during the day. Often called a sunspace, the greenhouse is similar to those used for plants. Even in cold climates, the sun will produce a magnificent amount of heat. Again, the problem is keeping the heat from escaping once it has built up. Since the sun has to come in through a transparent surface, you inevitably have the problem of the heat escaping through the same. The best option is to use a controlled timer to blow the air through to the house once certain temperatures are reached. It is not very efficient, but you have little choice.

An alternative to passive solar heating in very cold areas is biomass. Corn burning furnaces are popular. They are a much cheaper solution as are the corn kernels. This biomass energy is also much more reliable and, personally, it is the way I would go.

Is Passive Solar A Viable Home Heating Option In Cold Areas? is a post from: Reference Education Center