...covalently attach anions or cations onto it. Solute ions of the opposite charge in the mobile liquid phase are attracted to the resin by electrostatic forces. Molecular Exclusion Chromatography Also known as gel permeation or gel filtration, this type of chromatography lacks an attractive interaction between the stationary phase and solute. The liquid or gaseous phase passes through a porous gel which separates the molecules according to its size. The pores are normally small and exclude the larger solute molecules, but allows smaller molecules to enter the gel, causing them to flow through a larger volume. This causes the larger molecules to pass through the column at a faster rate than the smaller ones. Affinity Chromatography This is the most selective type of chromatography employed. It utilizes the specific interaction between one kind of solute molecule and a second molecule that is immobilized on a stationary phase. For example, the immobilized molecule may be an antibody to some specific protein. When solute containing a mixture of proteins are passed by this molecule, only the specific protein is reacted to this antibody, binding it to the stationary phase. This...
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...Extraction of DNA from an Onion Molecular biologists and biochemists are involved with research in finding out as much as possible about the DNA in plants and animals. Although DNA was discovered in the 1950’s, there still remains a lot to be known about it, especially how it is used to determine the physical traits that we all have, and how it regulates the workings of the body. We should always remember that DNA is just a chemical named deoxyribonucleic acid. Because it is a chemical, we can do reactions with it just like we can work with any other chemical. In this lab, we will use the chemical properties of DNA to extract it from the cells of onions. Experiment: Note: You should write all observations from this lab in the observation section on the third page of this lab. These observations will account for a large part of your grade, so be neat and complete! 1) Prepare a buffer solution by pouring the following into a clean 250 mL Erlenmeyer flask: - 120 mL of water (distilled water, if available) - 1.5 grams of sodium chloride (table salt) - 5.0 grams of baking soda (sodium hydrogen carbonate) - 5.0 mL of shampoo or liquid laundry detergent What buffer solutions are used for: This buffer solution is used in this lab for several reasons. First of all, the saltiness and acidity (pH) of the solution is very close to that in living things; as a result, the DNA will like to dissolve into this solution. Secondly...
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...Unit 2 Research Paper 1: Global Warming During the last fifty years, two environmental issues have received significant attention: global warming and the hole in the ozone layer. As scientists have investigated these two environmental phenomena some have made some effort to show that these two effects are somehow related. In this research paper I will further elaborate on their relationship. Ozone high in the atmosphere absorbs ultraviolet radiation from the sun, thereby protecting living organisms below from this dangerous radiation. The term ‘ozone hole’ refers to recent depletion of this protective layer over Earth's Polar Regions. People, plants, and animals living under the ozone hole are harmed by the solar radiation now reaching the Earth's surface—where it causes health problems from eye damage to skin cancer. In the 1980s, scientists discovered that the ozone layer was thinning in the lower stratosphere, with particularly dramatic ozone loss known as the ozone hole in the Antarctic springtime. This is caused by increasing concentrations of ozone-depleting chemicals in the stratosphere that come from spray cans and refrigerants. These long-lived chlorofluorocarbons or CFCs (chemical compounds with chlorine and/or fluorine attached to carbon) remain in the atmosphere for decades to over a century depending on the CFC. At the poles CFCs attach to ice particles. When the sun comes out again in the polar spring, the ice particles melt, releasing the ozone-depleting molecules...
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...suitable products The two bonds of ethylene are not identical. The second bond (pi-bond) is weaker than the first bond (sigma-bond). Thus, only a small amount of energy is needed to enter the system in order to convert a double bond into a single bond. This results in ethylene’s high reactivity. 4) Identify that ethylene serves as a monomer from which polymers are made • • • Ethylene is polymerised to polyethylene High pressures produce soft, low density polyethylene, consisting of tangled chains (with molecular masses 100,000) 5) Identify polyethylene as an addition polymer and explain the meaning of the term Addition polymerisation: a process in which many identical small molecules combine to form one large molecule, with no by-products. The small molecules are called monomers, while the large molecule is called a polymer. H C C H H H C H C H n H H n In addition polymerisation, no other products are formed. 6) Outline the...
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...The Long Road to Direct Factor Xa Inhibitors: A History of Anticoagulation Marjorie Burnsworth Tacoma Community College July 24, 2014 Abstract This paper explores the history of the chemical research and development of anticoagulant medications over the years and how this has lead to the development of direct factor Xa inhibitors (fXa inhibitors). Since ancient doctors first used leeches to treat their patients, people have been aware of the properties of anticoagulants and anti-thrombolytics, but the development of Heparin almost 100 years ago signified the start of a century of chemical discovery and development in the field of anticoagulation that has peaked in the last 25 years. Following the development of Heparin, scientists next developed Vitamin K Antagonists (VKA's), such as Coumadin, which gave an oral option for anticoagulation but they were not without side effects. Nearly 30 years passed before chemists came up with the next step forward in anticoagulation, low-molecular-weight-heparin (LMWH). It was LMWH that first opened scientists eyes to factor Xa and the possibility of considering it as a possible target for future anticoagulation. In order to proceed with development, however, they had to look back to the past. Back to leeches and heparin, as these would prove hold the keys to the future development of direct factor Xa inhibitors. The Long Road to Direct Factor Xa Inhibitors: A History of Anticoagulation ...
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...and flows easily through another gas. In a liquid , attractions are stronger because the particles are touching, but they have enough kinetic energy to move randomly around each other.Thus, a liquid conforms to the shape of its container but has a surface ; It resists an applied force and thus compresses very slightly ; and it flows, but much more slowly than gases. In a solid, the attractions dominate the motion so much that the particles are fixed in position relative to one another, just jiggling in place. Thus, a solid has its own shape, compresses even less than liquids, and does not flow significantly. Each phase change has a name and an associated entalphy change : Gas to liquid, and vice versa. As the temperature drops, the molecules in the gas come together and form a liquid in the process, changing from a liquid to gas, is vaporization. Liquid to solid, and vice versa. As the temperature drops further, the particles move slower and become fixed in position in the process of freezing ; In common speech, freezing implies low temperature because we thin of water. Gas to solid, and vice versa. All three states of water are familiar because they are stable under ordinary conditions. At ordinary condition, solid CO2 changes directly to gas, a process called sublimation. The heat of sublimation is the enthalpy change when 1 mole of a substance sublimes, and the negative of this value is the...
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...University of Phoenix [COM 220- 08 March 2009] Have you ever watched a television program, or read an article about Global warming? A person would be hard pressed to find someone who hasn’t. The news is hard to ignore since the information that is given to us comes from scientists or experts in the field of global warming. We are continually bombarded with information that the Earth is experiencing a warming trend, and human activity is to blame. The pollution that man creates is adding to the earth’s greenhouse gases. The resulting affect of global warming is triggering warmer temperatures around the world, and ecosystems are taking the toll. One of the most publicized looming catastrophes is the plight of the polar bears. Once the glaciers are gone, the polar bear will be extinct in the wild. Although, scientists say it is caused by the pollution that humans are creating, global warming is a natural phenomenon. Snow capped mountains are a wondrous sight to behold, and can be found on every continent. But, these massive ice shelf’s have a purpose that many people take for granted. Many people do not realize that glaciers are responsible for part of the world’s water supply. Revkin (2003) states “The melting is likely to threaten water supplies in places like Peru and Nepal” (¶ 19). The result from the melting glaciers will raise water levels and potentially create devastating floods over time. The eventual outcome that these countries will face once the...
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...Minnesota, Twin Cities THE INTEGRATION of microelectromechanical systems(MEMS) sensors and actuators with other classes of microcomponents—electronic, optical, and fluidic—onto a single substrate has the potential to create powerful and complex microsystems. To increase device performance and thus realize the potential of microsystems, it is now accepted that the integration must occur at the micro scale. There are two possible routes: either the micro-components are fabricated at their desired locations in a single process, or they are fabricated separately and then positioned using micro assembly techniques. Since many classes of micro components cannot be co-fabricated effectively due to materials and process incompatibilities, several research groups are developing micro assembly approaches. In the micro assembly route, different classes of micro components are fabricated in separate processes, removed from their substrates, and assembled onto a target substrate of choice. For most applications, sub micrometer positioning and methods for establishing high-quality mechanical and electrical connections to the substrate are required. As in co fabrication, small-area electrical connections are desirable as they provide interfaces with low parasitic capacitances, resulting in greater measurement sensitivity of the devices. One advantage of using micro assembly, rather than pursuing co-fabrication, is the fabrication process for each micro component can be optimized separately. Secondly...
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...Molecules 2010, 15, 6008-6018; doi: 10.3390/molecules15096008 OPEN ACCESS molecules ISSN 1420-3049 www.mdpi.com/journal/molecules Article Assessment of Euphorbia hirta L. Leaf, Flower, Stem and Root Extracts for Their Antibacterial and Antifungal Activity and Brine Shrimp Lethality Mohammad Abu Basma Rajeh 1, Zakaria Zuraini 1, Sreenivasan Sasidharan 2, Lachimanan Yoga Latha 2 and Santhanam Amutha 2,3,* 1 2 3 School of Distance Education, Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia; E-Mail: zuraini@usm.my (Z.Z) Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia; E-Mail: srisasidharan@yahoo.com (S.S) School of Biotechnology, Madurai Kamaraj University, Madurai 625021, India * Author to whom correspondence should be addressed; E-Mail: amutha_santhanam@yahoo.com; Tel.: 00604-6534818; Fax: 00604-6534803. Received: 25 July 2010; in revised form: 7 August 2010 / Accepted: 20 August 2010 / Published: 31 August 2010 Abstract: The antimicrobial activities of the methanolic extracts of Euphorbia hirta L leaves, flowers, stems and roots were evaluated against some medically important bacteria and yeast using the agar disc diffusion method. Four Gram positive (Staphylococcus aureus, Micrococcus sp., Bacillus subtilis and Bacillus thuringensis), four Gram negative (Escherichia coli, Klebsiella pneumonia, Salmonella typhi and P. mirabilis) and one yeast (Candida albicans) species were screened...
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...Polycaprolactam Student Name: Syed Ali Shahid, ID Number # 20595181; email: sashahid@uwaterloo.ca 1. Introduction and Applications Polycaprolactam or PA 6 is a synthetic polyamide commonly recognized by its trade name Nylon 6. Polyamides or nylons are polymers characterized by the amide group –CONH-as recurring part of their polymer chain. The original nylon was first made in a laboratory in DuPont, USA in 1935 by Wallace Carothers. It was recognized as the first semicrsytalline polymer, the first engineering thermoplastic, and the first synthetic fiber .Amongst various variants of polyamide, polycaprolactam is particularly different in that it is made from only 1 kind of monomer- caprolactam which will be discussed in this paper in further detail from various aspects. Schalak while working on polyamides in IG Fabraen laboratory synthesized polycaprolactam through ring opening polymerization of caprolactom. He heated caprrolactam in a flask to about 250oC with about 5-10% water which hydrolyzed a few percent of the caprolactam to aminocaproic acid. The NH2 group of the aminocaproic acid acted as ring opening initiator for polycaprolactam followed by a polycondensation reaction of the NH2 and COOH group of the low molecular weight product of the ring opening polymerization reaction resulting in a high molecular weight product-Polycaprolactam. The key properties of polycaprolactam that have made them suitable for a variety of industrial applications are toughness, fatigue...
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...CHAPTER I INTRODUCTION 1.1 RESEARCH BACKGROUND This research is about the extraction of keratin protein from chicken feathers using strong fluid extraction process. This extraction procedure utilized a dissolvable as lessening specialists to separate salt linkages, disulphide bond and hydrogen bond of the keratin fiber to break down into protein. Thus, it will likewise diminish the steadiness of keratin strands in the strong structure found in feathers. Proteins are polymer formed by one or more long chains of amino acid residues that are capable of promoting intra- and inter-molecular bonds so that it allows the resultant materials to have a large variation in their functional properties. Amino acids linked together by peptide bonds, form a polypeptide chain. Polypeptides are made of amino acids arranged in a linear chain and folded into a globular form. There are two...
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...CHAPTER I INTRODUCTION RESEARCH BACKGROUND This research is about the extraction of keratin protein from chicken feathers using strong fluid extraction process. This extraction procedure utilized a dissolvable as lessening specialists to separate salt linkages, disulphide bond and hydrogen bond of the keratin fiber to break down into protein. Thus, it will likewise diminish the steadiness of keratin strands in the strong structure found in feathers. Proteins are polymer formed by one or more long chains of amino acid residues that are capable of promoting intra- and inter-molecular bonds so that it allows the resultant materials to have a large variation in their functional properties. Amino acids linked together by peptide bonds,...
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...Contextual Outline Humans have always exploited their natural environment for all their needs including food, clothing and shelter. As the cultural development of humans continued, they looked for a greater variety of materials to cater for their needs. The twentieth century saw an explosion in both the use of traditional materials and in the research for development of a wider range of materials to satisfy technological developments. Added to this was a reduction in availability of the traditional resources to supply the increasing world population. Chemists and chemical engineers continue to play a pivotal role in the search for new sources of traditional materials such as those from the petrochemical industry. As the fossil organic reserves dwindle, new sources of the organic chemicals presently used have to be found. In addition, chemists are continually searching for compounds to be used in the design and production of new materials to replace those that have been deemed no longer satisfactory for needs. This module increases students’ understanding of the implications of chemistry for society and the environment and the current issues, research and developments in chemistry. 1.1 Construct word and balanced formulae equations of all chemical reactions as they are encountered in this module: • Acid reactions: o acid (aq) + base (aq) salt (aq) + water (l) o acid (aq) + active metal (s) salt (aq) + hydrogen (g) o acid (aq) + metal carbonate (s) salt (aq) + water (l) + carbon...
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...Fully formatted PDF and full text (HTML) versions will be made available soon. Polar extracts from (Tunisian) Acacia salicina 'Lindl. Study of the antimicrobial and antigenotoxic activities BMC Complementary and Alternative Medicine 2012, 12:37 doi:10.1186/1472-6882-12-37 Jihed Boubaker (jihed.boubaker@yahoo.fr) Hedi Ben Mansour (hedi.mansour@hotmail.fr) Kamel Ghedira (kamel.ghedira@gmail.com) Leila Chekir-Ghedira (leila.chekir@laposte.net) ISSN Article type Submission date Acceptance date Publication date Article URL 1472-6882 Research article 3 September 2011 10 April 2012 10 April 2012 http://www.biomedcentral.com/1472-6882/12/37 Like all articles in BMC journals, this peer-reviewed article was published immediately upon acceptance. It can be downloaded, printed and distributed freely for any purposes (see copyright notice below). Articles in BMC journals are listed in PubMed and archived at PubMed Central. For information about publishing your research in BMC journals or any BioMed Central journal, go to http://www.biomedcentral.com/info/authors/ © 2012 Boubaker et al. ; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Polar extracts from (Tunisian) Acacia salicina ‘Lindl. Study of the antimicrobial and...
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...J Polym Res (2012) 19:16 DOI 10.1007/s10965-012-0016-1 ORIGINAL PAPER Influence of matrices chemical nature on the dynamic mechanical and dielectric properties of rubber composites comprising conductive carbon black Omar A. Al-Hartomy & Ahmed A. Al-Ghamdi & Falleh Al-Solamy & Nikolay Dishovsky & Mihail Mihaylov & Milcho Ivanov & Farid El-Tantawy Received: 14 February 2012 / Accepted: 22 October 2012 # Springer Science+Business Media Dordrecht 2012 Abstract The study presents the effect that elastomeric matrices different in their chemical nature (a non-polar and crystallizing natural rubber and a polar and non-crystallizing acrylonitrile-butadiene rubber) have upon the dynamic mechanical and dielectric properties of the composites comprising different amounts of conductive carbon black. Dynamic mechanical thermal analysis (DMTA) and Dielectric thermal analysis (DETA) are the techniques used for studying the structure-properties relationships of the composites. The experimental results show that the matrices studied and their specific properties have a great impact O. A. Al-Hartomy : A. A. Al-Ghamdi Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia O. A. Al-Hartomy Department of Physics, Faculty of Science, University of Tabuk, Tabuk 71491, Saudi Arabia F. Al-Solamy Department of Mathematics, Faculty of Science, University of Tabuk, Tabuk 71491, Saudi Arabia F. Al-Solamy Department of Physics, Faculty of Science, King Abdulaziz...
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