cars Essay -- essays research papers

History of Cars By Kenny Carroll Motor car, road vehicle which first appeared in the 19th Century. The steam propelled the first cars, but such vehicles were not a success and the age of the motor car really dates from the introduction of the petrol-driven horseless carriages of Gottfrield Daimler and Karl Benz (1885-86). The internal combustion engine for these cars had been developed earlier by several engineers, most notably by the German, Nickolaus Otto, in 1876. The main components of a motor car, from then till now, are a body or chassis to which are attached all other parts - including the engine or power plant, the transmission system for transferring the drive to the wheels, and the steering, braking and suspension mechanisms for guiding, stopping and supporting the car. A few experts assembled the first cars, but Henry Ford and R. E. Olds in the USA began modern mass-production in the early 1900s. By this means, the cost of a car was drastically reduced, and more people could afford done. In most modern ca r factories component parts are put together on assembly lines - slow-moving conveyor belts. Each worker usually has a specific task, example fitting doors or crankshafts. Bodies and engines are constructed on separate assembly lines, which converge when the engine is installed. Overhead rail conveyors move heavy components to and along the assembly lines, and lower them into position. At a later stage on the assembly line such items as lamps are fitted, and electrical, braking and control systems are tested. The fully assembled car is road tested before sale. The automobile was not invented overnight. It took shape from an accumulation of technical advances that resulted in a light and efficient engine. The accepted "fathers of the modern motor car" are two Germans, Karl Benz (1844-1929) and Gottfried Daimler (1834-1900), who built their first petrol-fuelled motor vehicles within a few months of each other (1885-6). More than a hundred years earlier, the first self-propelled road vehicle had rumbled through the streets of Paris at nearly 5km/h (3mph) when Nicolas Cugnot (1725-1804) demonstrated his steam-driven wagon. The German Nikolas Otto (1832-91) made the first four-stroke internal-combustion engine in 1876 and in 1885 Daimler had installed a small four-stroke engine in a cycle frame. He drove his first four-wheeled petrol-dr... ... the advantage somewhat. Diesel engines offer economies in fuel consumption at the expense of a loss in performance; they are particularly suited to frequent stop and start duties, and as a result are widely used in taxis, buses and lorries. The gas turbine, a completely different kind of engine, was first devised at the beginning of the twentieth century (1900s) and perfected in the 1930s. It usually has a single shaft carrying a series of propeller-like fans divided into two groups, the compressor and the turbine. In an operating gas turbine air is drawn in the compressor fans and its pressure increased. The compressed air is mixed with fuel and ignition takes place, further increasing temperatures and pressures. The burned mixture leaves the engine through the turbine, driving the blades round. The compressor, which is often driven directly by the turbine, takes up much of the power produced, but enough is left to make the gas turbine exceedingly powerful form of engine. Efficiencies are not high, but the good power-to-weight ratio of a gas turbine makes it suitable for aircraft propulsion. A gas turbine is about three times as powerful as a piston engine of the same weight.

My Childhood Days Essay

It was a green world where I was born. I was born and raised in a small town which could almost know as countryside. Now, the small town has already collapsed and turned into a developing-city. It is so sad that I can only recall my childhood days in my mind instead of visiting the small town. It was a small town with warm-hearted villagers. We were all friends and always share our foods and games. Mak Kwan had the most famous cooking while En. Chong could fly the kite highest. Hmm†¦ I could still smell the curry in the air! My brother and I, we used to rush to Mak Kwan’s home and asked for curry when we smell it. Mak Kwan never decline and always offers us a big bowl of curry to share with our family. The satisfaction is so hard to describe. In my childhood days, I loved to fish in the rivers. Especially hand-fishing! I never like to fish with the rods because it is too messy. Although I like to fish, I am not good at it. So, it was always a big surprise for me when I succeeded to catch a fish. It made me smile all the day because I was over the moon! I usually went fishing with my brother. Not like me, he was good at hand-fishing. He could always catch a basket-full of fish. But, we only chose a fish to bring home and let the others go. Brother said that this was to make sure that there are always fishes in the rivers. One day, I watched â€Å"Recess† and I was so impressed by the tree-house. I asked for permission to build a tree-house, and my father promised to make me one! God is so good to me! My dad said that it was his dream when he was small too, so, he tried to make his and my dream came true. Then, we started to proceed. First, we selected a tree which was suitable to build a tree-house. After that, we drew a simple blue-print of the tree-house. We chopped down some trees and cut them into boards (it was not encouraged to cut down trees at that time, but no one stopped us because everyone was excited to see the tree-house). After three months, it was done! Not as luxurious as the one in â€Å"Recess†, but it was pretty good. At that time, I thought that I would become a good architect because I could design and build. Now, I learned that I was naive and stupid. In my childhood days, it was not only my playground, but also my safe haven when I was scolded by my parents. It use d to be my home to home. In the small town I lived, there was a small jungle. My brother and I enjoyed jungle trekking and explored some new things in the jungle. We had an album named ‘Jungle Diary’. We wrote down all the interesting incident during the exploration. We also collected the unique leaves, sticked it in the album and did some notes. We also liked to observe the animals’ lifestyle. We had an old digital camera, we shot the photos of the birds and wrote down the characteristics. It was fun. One time, we followed a deer along and accidentally went in too far into the jungle. We got lost! It was a terrible incident, I absolutely don’t want to recall it. In my childhood days, all the children in the village loved to fly kites. As I said before, En. Chong could fly the kites highest. So, he taught us how to fly the kites high in the sky. It was all about control. If the string is too tight, It breaks, but if it is too loose, it can’t go high. Just like our life. In a windy season, we organized a small kite-flying competition. Although it was small, everyone took it seriously. Because the design and beauty of the kites would be judged, we had to do it on our own. No shop would sell the kites at that time to prevent us from cheating. Of course, En. Chong was the busiest person because everyone asked for his help to make sure the kites could fly. En. Chong is a selfless person, he never declined to teach. He said that he was happy that many people tried to learn the way of making a good kite. It was not easy as what we thought, I failed three times before I got it. It was a big day, the competition. I didn’t win the first p lace, but it was a very memorable incident. I am not going to forget it. There were else more funny and wonderful memories in my childhood days. Unfortunately, kid nowadays can’t experience these funny things anymore. In the city now, people don’t even bother to know their neighbour’s name. The river is polluted, the tree with tree-house is gone, no more jungle for us to explore, and how often can we see the kites in the sky? They said it is the inevitable price for the modernization and industrialization. Yes, thanks to the development, and the pollution. I am glad that I was born in the 90s. Shame for the 00s, all they have is the internet. In the time comes, we will learn that how much hurts we had brought to our Mother Earth.

Volumetric Flask Definition in Chemistry

A volumetric flask is a type of laboratory glassware used to prepare solutions. A volumetric flask is a flat bottomed bulb with a elongated neck calibrated to hold a set volume at a mark on the neck. The flask may also be called a graduated flask or measuring flask because its mark specifies a precise volume measurement. The mark on the flask neck indicates the volume contained. When emptied, some portion of liquid may remain in the container, so the mark (unlike for a pipette) does not indicate the amount to be dispensed. It should be noted volumetric flasks are calibrated for a particular temperature (usually  20  Ã‚ °C), which is indicated on the label. Most volumetric flasks are either transparent glass or plastic, although some flasks are amber-colored for the preparation of light-sensitive solutions. The mouth of the flask may have either a joint to accommodate a stopper or a screw cap. Volumetric Flask Standards All volumetric flasks are not created equal! There are higher and lower precision flasks. A volumetric flask made to conform to a high standard is a Class A or Class 1 flask. Its tolerance, temperature, precision, and volume will be indicated on the glassware. A Class B flask does not conform to as high a standard and may not include all of this information. Class A flasks are used for analytical chemistry work, while Class B flasks are suitable for most educational and qualitative work.