spectroscopy. The presence of glycidyl units in these resins enhances the processability but reduces thermal resistance. The most widely used curing agents for epoxy resins are primary and secondary amines. The overall reaction rate of an amine with an epoxide is influenced by the steric hindrance and the electron withdrawing or electron donating groups present in the amine 1. Epoxy groups are rearranged and form direct linkages between themselves. 2. Aromatic and aliphatic -OHs link up to the epoxy groups
Table 1 provides the results from this experiment by showing which halides did react with the 1% ethanolic silver nitrate solution and which ones did not react. Through the evaluation of the precipitate, 2-chloro-2-methylpropane reacted instantly with the silver nitrate solution. This reaction occurred instantaneously due to the fact that SN1 reactions favor steric hindrance and the leaving group, chlorine, was a tertiary substrate. On the other hand, the two substrates that had secondary leaving
The metabolism of carfilzomib consists of two pathways peptidase cleavage and epoxide hydrolysis, that were found in peptide pieces with the diol metabolite in carfilzomib. The drug has a half-life of less than one hour and is excreted by biliary and renal excretion, less than one percent of the drug remains complete [7]. All drugs
industrial products via the synthetically versatile epoxy function . In this paper, a synthesis of Jacobsen's catalyst is performed (Scheme 1). The synthesized catalyst is then reacted with an unfunctional alkene (dihydronaphthalene) to form an epoxide that is highly enantiomerically enriched, as well as an oxidized byproduct. Jacobsen's work is important because it presents both a reagent and a method to selectively guide an enantiomeric catalytic reaction of industrial and pharmacological
Normally, emulsified water is generally present in crude oil as a result of the mixing occurring during production operations and referred to as oil field emulsion. This emulsion can be encountered at numerous stages include during drilling, producing, transporting and processing of crude oil. However, the formation of emulsion creates problems in oil field industry. They might increase the cost of production and also transportation; accumulate in the refinery tank age, pipeline corrosion, equipment
Memorial for Unborn Children The loss of a child is one of those experiences in life that I hope and pray I never have to endure. In life, there are various ways in which a mother could lose her child. For example, One way that I’m sure doesn’t really cross the minds of most of society is that of those who have had an abortion. Nonetheless, the overall the choice to have an abortion is a mother’s choice and her choice alone. Correspondingly, it does still come with a price and in most cases; a woman
Hardness test In this study hardness was determined using standard Rockwell A. The tests were conducted at room temperature and under ambient humidity conditions. Hardness testing machine (Avery Denison 6407 150Kgf) was used in the test. Tension test Tension tests were carried out on the various silica, alumina and carbon nanophased epoxy specimens according to DIN 53457 [15]. The test specimens were cut into strips of 170 mm length, 15 mm width and 3 mm thickness. Tension tests were carried out
Bioaffinity chromatography is a type of affinity chromatography in which biological compounds such as immunoglobulin-binding proteins, enzymes, lectins, carbohydrates, avidin/biotin system and antibodies are used as ligands (Hage, 2006). Immunoglobulin-binding proteins, namely protein A which is produced by Staphylococcus aureus and protein G which is produced by streptococci, are the ligands that are used in the vast majority of bioaffinity chromatographic applications (Tetala and van Beek, 2010)
2.3 Graphene Oxide Graphene Oxide is single sheets containing defect sites arising from partial oxidation of the edge and basal plane and graphene is an atomically flat single layer of C-atoms with outstanding electrical, mechanical and photonic properties. Figure 1 below shows the structure of graphene oxide. Figure 1: Structure of Graphene Oxide (Gao et al., 2009) Graphene oxide is an amorphous with an sp2 hybridised carbon (graphene) base littered with oxygen groups a C/O ratio of between
Composite materials is also called composition materials or shortened to composites. They may be selected to give unusual combinations of weight, stiffness, high temperature performance, strength, corrosion resistance, conductivity, or hardness. They are materials made from two or more constituent materials with significantly different physical or chemical properties. When combined, they produce a material with different characteristics from the individual components. The individual components will
Introduction This assignment is to address the issue of product marketing. Marketing is defined as the activity, set of institutions and processes for creativity, communicating, delivery and exchanging offerings that have value for customers. It has become crucial to success in our modern competitive economic. Volterman wallet was created and introduced recently to the world market to overcome the loss of wallet which has become a common problem. To enhance its popularity, the Volterman wallet has
I.ZnO/Eugenol based sealers: This group of sealers encompasses a large number of products, they have relatively the same composition, but with some additives to improve the properties of the sealer. The composition of ZOE sealers: Sealer Powder Liquid Rickert's sealer Zinc oxide (41.2 parts) Precipitated silver (30 parts) White resin (16 parts) Thymol iodide (12.8 parts) Oil of clove (78 parts) Canada balsam (22 parts) Grossman's Sealer Zinc oxide reagent (42 parts) Staybelite resin (27 parts) Bismuth
The Chemical Synthesis of Oligonucleotides and the Phosphoramidite Method By Klaus D. Linse The study of nucleic acids has now become a fruitful and dynamic scientific enterprise. Nucleic acids are of unique importance in biological systems. Genes are made up of deoxyribonucleic acid or DNA, and each gene is a linear segment, or polymer, of a long DNA molecule. A DNA polymer, or DNA oligonucleotide, contains a linear arrangement of subunits called nucleotides. There are four types of nucleotides
In a healthy human being, the body is able to prevent excessive bleeding. This prevention occurs through the action of plasma and this specific action causes the plasma to become sticky and form clots. Clots are composed at the place where the injury occurs to stop excessive bleeding due to possible wounds in the area and potentially causing death. Clotting takes place naturally and it relies on many chemical reactions occurring in the body so a substance called thrombin can be produced. However
Cancer is a genetic disease because it can be traced to alteration within specific genes, but in most cases, it is not an inherited disease. The genetic alterations that lead to most cancers arise in the deoxyribonucleic acid (DNA) of a somatic cell during the lifetime of affected individual. Because of these genetic changes, cancer cells proliferate uncontrollably, producing malignant tumour that invade surrounding healthy tissue. As long as the growth of tumour remains localized, the disease can
Certificate in Minor Oral Surgery Cohort 3 2014-15 Formative Assignment 1 Anticoagulant therapy is a relatively common long term treatment in UK medicine. Outline what medical conditions might indicate its use. Outline the different types of agents which have and are used and how they affect the physiology of the blood clotting mechanism. Using an evidence base how should patients in this category be managed in primary and secondary care when undergoing different oral surgical procedures.