Zinc
Zinc, number 30 on the periodic table and a bluish-white metallic element, exists naturally in air, water and soil. It is present everywhere in the environment. All life on earth has evolved in the presence of zinc. Natural processes such as erosion, forest fires, aerosol formation above the seas and volcanic eruptions continuously transport Zinc. Zinc melts at about 420° C and boils at about 907° C. Zinc is efficient for plants.
The ZnO crystallizes in a few forms which are wurtzite, zinc blende and rocksalt as shown in Figure 2.4. The wurtzite structure is the most thermodynamically stable phase under ambient temperature and also very common. The zinc blende ZnO geometry can be stabilized only by growth on cubic lattice substrates and the rocksalt structure (NaCl structure) can be obtained at relatively high pressures using ultrasonic wave velocity measurements of up to 10 GPa. (Morkoc).
Metals are currently in high demand by society. A high percentage of common everyday items you use and see utilises a form of metal. That wooden table in a common kitchen that looks like it is made completely of wood. Metals are still used in that "completely wooden table" as the screws used to hold it together are made of metals. Many commonly used metals such as iron, aluminium, and/or copper are all found from ores. An ore is a mixture in the form of a rock that is mined. For example, bauxite is an ore that contains a high percentage of pure aluminium. That pure aluminium is then extracted, refined, and crafted in to many everyday items such as cars, foil, and ladders. Chemists are continuously researching an innovative approach to extract and refine pure metals from ores while using fewer amounts of energy. Society's requirement of metals is increasing by the year as science and technology advances.
Through the years, the process of turning raw materials into useful materials is a tradition that hasn’t changed over hundreds of years. The general process of turning metal to blades, silicon to magic mirrors or computers and ceramics to pottery or circuits. If we examine the past we can learn much about our future because all technological advancements need is to look to our ancient ancestors and examine how they dealt with the problems of their time.
The first known source of silver is believed to be the mines around Anatolia, now known as Turkey, in 4000 BC. This supplied the flourishing cultures around Greece, Crete, and the Near East. Around 2500 BC the Chaldeyans developed a process called “cupellation” to extract silver from silver-lead ores. During the rise and fall of civilizations around Europe and Asia Minor, silver value remains high, with major silver sources moving from Laurium (near Athens, and produced the largest amount of silver during this era), Asia Minor, Sardinia, Asia, Spain, Germany, and Austria-Hungary.
The preservation of modern architecture itself challenges some of the fundamental concepts of preservation of historic buildings. As the time scale of buildings shrink, these challenges need to be addressed taking into consideration the burgeoning new modes and materials of construction.
Gustave Eiffel was an influential architect and civil engineer who helped primarily in the construction of magnificent iron works around the world. These works are still considered to be timeless masterpieces, and can be found in France, Germany, Peru, the United States, and many other countries across the globe. One cannot understand the works of Eiffel before understanding his background in architecture and the life that inspired his pieces. This analysis will comprise a brief biography of Gustave Eiffel and the type of work he was involved with, followed by a discussion of Eiffel’s achievement in timeless quality with his most prominent works. His most significant works include (but are certainly not limited to) the Statue of Liberty, the Maria Pia Bridge, and the Eiffel tower.
By adding up to 2%,of carbon it makes the steel tough and strong. Although it’s tough and strong, it is able to bend. To make sure that the metal doesn’t rust, it has a zinc coating on it. Iron is 26 on the periodic table,and considered an “transition metal,” meaning that it is ductile and malleable, and conduct electricity and heat. ... “Some other elements that are similar to iron are cobalt and nickel. They are the only elements known to produce a magnetic field.” Zinc is 30 on the periodic table and it is also a transition metal like iron. “The first iron used by humans is likely to have come from meteorites.” A meteorite is a meteor that survives its passage through the earth's atmosphere such that part of it strikes the ground. More than 90 percent of meteorites are of rock, while the remainder consist wholly or partly of iron and nickel. Meteors are believed to have been from the asteroid belt of Mars and
During the past few hundred years, zinc has been known to be the vital mineral and catalytic of a lot of proteins and a signalling messenger who is released by neural activity. (choi & koh, 1998) Since zinc has been discovered by raulin in 1869 to be needed as a grower of aspergillus niger which is type of fungus and one of the most common species of the genus aspergillus, this fungus is common contaminant of food and cause black mould on certain food. Beside the cause of contaminated food, zinc has been admitted as important for human in modern times.(Prasad, 1984) (Hambidge , 2000) (Vallee & Auld, 1990)
However, the success of the building schemes relied on the construction methods and innovations that are now attributed as bei...