The transformation temperature is strongly influenced: by the interstitial elements oxygen, nitrogen, and carbon (alpha stabilizers), which raise the transformation temperature; by hydrogen (beta stabilizer), which lowers the transformation temperature; and by metallic impurity or alloying elements, which may either, raise or, lower the transformation temperature…
HARDNESS Hardness of a material is most commonly defined as the measure of its resistance to penentration by an indenter.Hardness is also measure of strength and often has the units of stress .The indenter is often fabricated from a hard material such as diamond or hardened steel.The tips of the indenters may be conical,pyramidal,or spherical in shape.The indenter tips may also be relatively small(nano-or micro-indenters) or very large(macroindenters).Since indentation tests are relatively easy…
THEORY Injection molding is the most commonly used manufacturing process for the fabrication of plastic parts. A wide variety of products are manufactured using injection molding, which vary greatly in their size, complexity, and application. The injection molding process required the use of an injection molding machine, raw plastic material, and a mold. The plastic is melted in the injection molding machine and then injected into the mold, where it cools and solidifies into the final part.…
Polymer - A word, which is connote for large molecules (that a molecule made from simple repeating units called monomers). The monomers are main building block of polymers. Polymers play an essential and ubiquitous role in everyday human life because of the extraordinary range of properties. Polymers are among the most widely used and important type of materials today. Polymers have been with us from the beginning of time; they form the very basis (building blocks) of life. Animals, plants all…
gently for 5 minutes. Allow the mixture to cool slightly and filter by gentle suction and wash it 3-4 times with CCl4. Recrystallize it from the boiling water. Mechanism: The Reaction involves: Nucleophilic attack of NH2 of glucine on the carbonyl carbon of benzoyl chloride Rearrangment and deprotonation (elimination of HCl molecule) to give benzoyl glycine Step II: Preparation of 4-Benzylidine-2-phenyl-oxazol-5-one from benzoyl…
a) Heckel equation In 1961, Heckel proposed the most widely used equation describing pharmaceutical powder behavior in compaction. It was initially used to study the densification of ceramics and its correlation with pressure. It a first order process where powder pores elimination rate is correlated to the number of pores present. The rate of volume reduction increases as the number of pores decrease. Heckel equation relates the density, pressure and the pore fraction of the powder [16],.…
Schiff Bases: Schiff bases are amongst the important class of drugs containing imine or azoethine (-C=N-) moiety,have been obtained by the condensation of primary amines and carbonyl compounds.It was first time presented by the Hugo schiff (Cimerman et al, 2000). Schiff bases are one of the most important class of organic drugs widely used in variety of different fields such as analytical, biological, and inorganic chemistry.The schiff bases heve been designed to synthesize more and more novel…
In this work we have prepared ceramic-polybenzoxazine composites based on poly(P-ddm) as matrix reinforced by 0, 3, 5, 7, 10, 15, and 20 wt.% of GX-540 silane-treated nano-Cr2O3 filler via a solution blending method in THF. These nanocomposites are used as new organic coating materials. The effect Cr2O3 nanofillers inclusion on the viscoelastic properties of poly(P-ddm) is studied using dynamic mechanical analysis (DMA). Figure 76 illustrates the change in the storage modulus at 50oC and…
spacecraft carbon nanotubes are expected to used. Rocket propulsion, of course, includes combustion. Combustion is where a substance reacts with oxygen and gives off heat. The source of oxygen is called an oxidizer…
the essay is carbon 14 isotope. Carbon is found in all living things and is the building block for organic material, there is carbon 12, 13 and 14 and they all have different properties. This isotope was discovered on February 27, 1940 by Martin Karmen and Sam Ruben and is the most radioactive out of all carbon isotopes. The relative abundance of it is >0.1% (trace amount) and its relative mass is 14.003241. It has 6 protons and 8 neutrons. This particular isotope is found in all carbon…