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Your search returned over 400 essays for "polymers"
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Understanding Polymers - Polymers are always been around everywhere we go and have been increasing as time goes on. From its inception until today, polymers have enhanced our quality of life. The common questions asked here are usually what they are, where can I find them, where did they come from, how they are made, and what are some future possibilities. The first thing you might want to know about polymers is what they are. Polymers can be very complicated and you can do into great depth to what they are. “Polymers are molecules which consist of a long, repeating chain of smaller units called monomers.” The next question would be what monomers are....   [tags: Polymers]
:: 7 Works Cited
1066 words
(3 pages)
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Natural Polymers in Our Body - ... Cellulose is use as the forerunner to ethanol production. Then what happens subsequently is glucose is fermented by yeast to make ethanol. Ethanol is a major product because it is use in alcoholic beverages, and it is used as an antiseptic and a fuel stabilizer in gasoline. According to how it is treated, cellulose can be used to make paper, explosives, plastics, and cotton, is produced by the cotton plant: it is dyed and used as a fabric, which is used to make clothes. Many plants also make starch, for instance potatoes, corn, and grains....   [tags: linkage, natural, toxins polymers]
:: 2 Works Cited
615 words
(1.8 pages)
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Chemistry: New Era for Organic Semiconducting Polymers - ... Metal-catalyzed cross-coupling polymerizations resulted polythiophenes with high molecular weights as well as reasonably high electrical conductivities.16-20 These PATs consist of 2,5-coupling and lack 2,4-coupling due to the steric hindrance caused by the alkyl groups substituted at the 3-position. In 1992 Yamamoto et al. reported the synthesis of PATs from 2,5-diiodo-3-alkylthiophenes using Ni(0) as the catalyst, and claimed that diiodothiophenes are more active monomers towards the catalyst in comparison to dibromothiophenes.21 Kaeriyama and co-workers undertook electrochemical polymerization of 3-methylthiophene and 3-ethylthiophene to produce a series of poly(3-alkylthiophenes)...   [tags: Semiconducting Polymers, Polythiophenes] 2600 words
(7.4 pages)
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The Combustion of Polymers - Introduction The history of polymers stretch back millions of years. These “primitive” polymers were created by nature to fulfill the needs of information storage, energy storage and information reproduction. Human made polymers are a more recent invention, of the last two hundred years or so. These polymers are general made of highly flammable hydrocarbons and their derivatives. Fires caused by a combination of human careless and the physical properties of hydrocarbons have caused millions of dollars in property damage and claimed an untold number of human lives....   [tags: flame, retardancy, reaction, polymer] 1568 words
(4.5 pages)
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The Imporance of Polymers Today - ... With the use of polymers scientist were able to create an effective and cost efficient substitute for metals and ivory, which we used to use for making common items such as handles, pool balls, and game pieces. They were all made of ivory and since ivory is very rare and hard to obtain it raises the prices of all items made of this material. With out plastics plates, cups and silverware would still be being made of metals or other expensive material. But eventually people started replacing these things with plastic....   [tags: history of chemistry] 644 words
(1.8 pages)
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Chemistry and Tissue Engineering: Synthetic Polymers - ... In addition to the fast and efficient polymerization process, PVA hydrogels can be tailored to produce materials with mechanical properties appropriate for a desired application (Jiang, Liu and Feng, 2011). Further, the numerous pendent hydroxyl groups provide sites for the attachment of bioactive molecules, such as peptides, to signal cell attachment, proliferation, differentiation, or migration (Stephens‐Altus et al., 2011; Ranjha and Khan, 2013). Schmedlen et al., reported photoactive polyvinyl alcohol hydrogels (PVA) for use as tissue engineering scaffolds (Schmedlen et al., 2002)....   [tags: PEG, natural pymers, ] 1340 words
(3.8 pages)
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Taking a Look at Polylactic Acid Polymers - ... corn, sugar cane, etc.) [2]. It is an adaptable polymer, as above mentioned it is easily recyclable and compostable, but also possesses properties such as high transparency, and high molecular weight, it is also easy to manipulate and possesses great water solubility resistance. Depending on its ratio of L-lactide/D-lactide enantiomers, PLA’s molecular structure can vary significantly from semi-crystalline to amorphous, with the amorphous structure being more easily processed through thermoforming [1]....   [tags: green packaging solutions] 1523 words
(4.4 pages)
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Aspects of Polymers - Aspects of Polymers Plastics are polymers. A simple definition of a polymer is something made of many units. Each link of the chain is the -mer or basic unit that is usually made of carbon, hydrogen, oxygen and or silicon. To make the chain, many links or -mers are polymerized together. Many of the common class of polymers are composed of hydrocarbons. Examples of polymers made up of only hydrogen and carbon are polypropylene, polybutylene, polystyrene and polymethylpentene. Polyvinyl chloride (PVC) contains chlorine....   [tags: Papers] 641 words
(1.8 pages)
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Structural Control in ATRP Synthesis of Star Polymers - Structural Control in ATRP Synthesis of Star Polymers Using the Arm-First Method and their Applications to the Medical Field Introduction Polymers are large molecules composed of small repeating units called monomers. There is a unique type of polymer called star polymers because of their shape.1 They consist of a central core with attaching monomer arms that can form branches.1 Interest in the synthesis of star-shaped polymers began in the 1950’s because of living anionic polymerization.1 By living I mean that the polymers ability to terminate has been removed....   [tags: Arm First Method, Applications, Medical Field]
:: 2 Works Cited
1915 words
(5.5 pages)
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Electro-Active Polymers in Finite Deformation - Characterization and Analysis - Abstract This work deals with electroactive polymers (EAP), materials that can undergo large deformations when subjected to electric field. This property attracted in the last decade the academic and the industrial communities, who try to utilize these materials as actuators and sensors. Electroactive materials are elastic, can undergo large deformations and possess fast response time. However, their wide-spread use was hindered by their limitations: the need for large electric field, small forces and low energy density....   [tags: Engineering] 2064 words
(5.9 pages)
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polymers - Cornstarch is an example of a polymer. Polymers are long strains of molecules that keep repeating and have different properties of the original single molecule group. A single section of a polymer is called a monomer. It resembles the simplest form of the repeating portion of the entire polymer. These polymers may get stretched when you make a mixture such as cornstarch and water. This mixture behaves a certain way. There are many theories on why this may occur. One theory is because the strands get tangled, making it hard for them to slide against each other....   [tags: essays research papers] 889 words
(2.5 pages)
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Using Polymers to Replace Absorption Glass Mats - This report outlines the evaluation for replacing an absorption glass mat (AGM) with a polymer mat to be used in a valve regulated lead acid (VRLA) battery. AGMs are expensive and exhibit low tensile strength, so polymers were investigated to both decrease cost and improve the properties of the mat. Initially the important properties of the mat were assumed to be chemical inertness in aqueous acid, stability towards oxidation and heat, wettability and contact angle, porosity, and tensile strength....   [tags: Materials Engineering] 677 words
(1.9 pages)
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Structural Suitability and Modelling of Glass Fiber Reinforced Polymers - ... The viscoelastic behaviour of a stiff material such as GFRP can be recorded in a stress-relaxation test, by subjecting the test specimen to a sudden strain and keeping this strain constant for the duration of the test. This was done in the second test which was based on ASTM E328-02(2008), ‘Standard Test Methods for Stress Relaxation Tests for Materials and Structures [16], and returned the Young’s modulus of the material as a function of time, E(t). A static axial clip-on extensometer of 25 mm gauge length and ±0.125mm accuracy (at gauge length) was used in both tests to measure the change in length parallel to the direction of the load applied....   [tags: GFRP in structural design]
:: 26 Works Cited
3854 words
(11 pages)
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Advantages and Disadvantages of Synthetic and Natural Fibers - Synthetic and natural fibers are the most essential part in clothes manufacturing. They make up the clothing we wear everyday. Fibers are made up of polymers, which are an arrangement of large molecules that are then made up of groups of even smaller molecules that are linked together to form a large chain structure. The smaller molecules are called monomers, and when they join together larger molecules are produced, making macromolecules (Bailey). Synthetic fibers are made up of polymers giving them more unique abilities while still being an affordable alternative to natural fabrics....   [tags: clothes, fibers, polymers, nylon] 846 words
(2.4 pages)
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Reliability Based Multi-Objective Optimization of RC Beams Shear Strengthened with CFRP Wraps - ... Furthermore shear fractures of RC beams are brittle and catastrophic in comparison of flexural mode and shear capacity of RC beam can dictate its critical strength. When shear capacity of a structural member is lower than its flexural capacity, the shear strengthening could be necessary [2ar-2book].Because flexural mode allows stress redistribution in plastic hinges and provides warning to occupants. Therefore the cost of applying FRP for shear strengthening of RC beams is very repetitive in a FRP rehabilitation project and it is so expensive and development a little cost saving of applying FRPs for shear strengthening can make a rehabilitation project so economical....   [tags: fiber reinforced polymers] 830 words
(2.4 pages)
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The First Dental Adhesive Resins - ... Hence microfilled composites aren’t used in posterior restorations and not commonly used today. Hybrid Composites are made up of resin matrix and 60% or more composes of different composition and size of glass particles which range from 0.6-1µm and also containing colloidal shaped silica particles with 0.04µm diameter. Hybrid composites reduced polymerisation shrinkage, low water absorption, similar wear and thermal expansion co efficient to tooth structures, it has good polishability and also able to mimic tooth structure in terms of opacity and colour....   [tags: microfilled composites, polymers] 800 words
(2.3 pages)
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3D-Printing Polymer Research and Development - In the current age of technology the demand for innovations and renovations to existing 3D-technology, has drastically increased. 3D-printing is being used in a wide variety of fields, and this is due, in part, to an increase in the efficiency and capabilities of these printers. With this increased efficiency however, comes the questions of what polymer is the best one to use in 3D-printing. Here following, the focus is on 3D-printing polymers that can be used in the medical field. And how may these polymers be produced at a reasonable price....   [tags: innovations, renovations, printing revolution]
:: 18 Works Cited
1406 words
(4 pages)
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A Brief Look into Polymer Processing - 1. Introduction Polymeric materials play a functional role in every aspect of daily life, from clothing to infrastructure. Polymers differ greatly from other materials, such as ceramics or metals, based upon the types of bonding. Metals bond metallically, creating a sea of electrons, and ceramics generally bond ionically, strongly tying electrons to lattice points. Polymers bond covalently in carbon chains, which (in general) make their properties more variable due to the possibilities of arrangement in bond length, angle, and molecular configuration....   [tags: polymeric materials, chemistry, bonds]
:: 6 Works Cited
2553 words
(7.3 pages)
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Conduction Mechanism of Polymer Electrolyte - ... The conductivity together with amorphous nature of polymer blend (reduction in crystallinity with increasing amorphousity) increased gradually with increasing in salt content and reach the optimum value at 20 wt.% of NH4Br as proven in Cole-cole plot study (Figure 1). Figure 2: Salts content dependence of CMC/CS-NH4Br electrolyte film at selected temperature Besides that, the conductivity of 20 wt.% NH4Br seems to increase from 2.12 x 10-5 Scm-1 to 3.51 x 10-5 Scm-1 at higher temperature applied....   [tags: conductivity, polymer electrolyte, frequency] 1389 words
(4 pages)
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Application of Polymer Scaffold in Tissue Engineering - ... Poly-lactic acid is a semi crystalline compound and chiral compound which contains three isomeric forms which are D (-), L (+) and racemic (D, L) polymer. Chiral compound contains an asymmetric center and has a non-superposable mirror image. Poly-L-lactic acid [PLLA] is about 37% crystallinity, the glass transition temperature is between 60 to 65 degree℃ and the melting point is between 175 to 178 degrees℃ ompared with PGA, the degradation time of PLLA is much slower as it takes about two to five years for full resorption in human body....   [tags: biology, dna, biomaterial] 1898 words
(5.4 pages)
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Manufacturing Polymer Components - ... A softer polymer was used for the lens case and switch while the reflector underwent an additional process of polishing with aluminum to increase its reflective capabilities. Bulb assembly The light used within the torch is an incandescent bulb which consists of a metal filament sealed within a glass globe which is heated and so glows releasing light. The incandescent bulb is manufactured by welding the filament to copper wires which pass through holes in the cylindrical glass base. This glass base is then placed within a fixture and the exposed filament is encased with a cylindrical glass envelope....   [tags: injection molding, ]
:: 6 Works Cited
937 words
(2.7 pages)
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Practical Applications of Polymer Electrospinning Technology - Electrospinning is a method for the generation of nanofibers. It uses an electrical charge to produce fibers from a polymer solution or melt. It’s a process that has been around for some time. The first recordable observation of electrospraying, a similar process, was made by William Gilbert in the late 1500s. Electrospinning as we know it today was described in a 1902 patent (US 62631) by J. F. Cooley [1]. His patent was entitled “Apparatus for Electrically Dispersing Fibers”. Since the early 1990s interest in Electrospinning has increased substantially as evident by the rapidly increasing number of publications [2]....   [tags: science, nanofibers]
:: 10 Works Cited
1390 words
(4 pages)
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Development of a Polymer-Based Matrix Tablet - ... The results of in vitro drug release studies were treated with zero order, first order kinetics, Higuchi, Hixon-Crowell and Korsemeyer‐Peppas model. In our experiments, the in‐vitro release profiles of drug from all the formulations could be best expressed by Higuchi’s equation, as the plots showed high linearity (r2= 0.972 to 0.999 ) to confirm the diffusion mechanism. The data were fitted into Korsemeyer‐Peppas model. All formulations F1 to F6 showed high linearity (r2= 0.969 to 0.998), with slope (n) values ranging from 0.383 to 0.683....   [tags: producing dosage form of Acebrophylline] 614 words
(1.8 pages)
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Biodegradable Nanoparticles for Drug Delivery - ... However, it is not only imperative to deliver a therapeutic agent to into a specific tissue but also to transport it within a specific cellular compartment [30]. One of the biggest obstacles intracellular trafficking is the penetration of the cell membrane, low convenience of the drug within cell, degradation of the drug in specific cell compartments or cytotoxicity caused by the within undesired to exposure of the drug and/or the delivery system to different cellular organelles [30], [31]. The prevention of membrane transport institiuted by the efflux transporters or membrane bound p-glycoprotein in tumor cells requires unique innovations in the localized delivery within the cells by by...   [tags: polymer science] 2179 words
(6.2 pages)
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Controlling Excess Water Production during Oil and Gas Recovery - ... Starch hydrocolloids have not been effective alternatives to partially hydrolyzed polyacrylamide, copolymers and xanthan gum polymers as water shut-off agents in fractures and in matrix flow configurations in the past years. Meanwhile, nowadays, the demands of the oil and gas drilling industry have led to the development of new drilling with improved functionality. Polymer flooding is very important method to increase oil recovery and reduce water production. Polymer and cross-linker are mixed at the surface first before being injected into the reservoir rock through a production well....   [tags: use of polymer gels] 538 words
(1.5 pages)
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Developments to Hydrogels Made From 2-Hydroxyethyl Methacrylate - ... Proteins, such as sodium caseinate, are the most commonly used emulsifier in food industry [1]. Polysaccharides and their mixtures are widely employed to control the rheological properties of oil-in-water-emulsions, thus also contributing to emulsion stability due to their texturing properties. The main stabilizers employed in food emulsions are xanthan gum, galactomannans, and native or modified starch since they are good thickening agents of aqueous solutions [2]. They have the efficiency for enhancing both the viscosity and the stability of emulsion depend on the polymeric concentration and structure [3]....   [tags: polymer, xanthan gum, biomaterials] 708 words
(2 pages)
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Polyethylene and Polyterephthalate are Outdated - Poly(ethylene terephthalate) Outdated: Is the World Ready for a New Plastic. Abstract: This paper explains the structure of polymer poly(ethylene terephthalate) also known as PET. It states the properties of the plastic as well recycling methods. My goal was to find out what makes PET the number one plastic, both in consumption as well as the most recycled. I also searched for new polymers that are being created by scientists and compare them to PET to see if there was a plastic out there that is better for the environment....   [tags: Polymer PET Plastic]
:: 4 Works Cited
1462 words
(4.2 pages)
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Polyethylene - German Chemist Hans von Pechmann first synthesized Polyethylene by accident in 1898 by heating diazomethane. His colleagues characterized the waxy substance polyethylene due to the fact that they recognized that it consisted of long ethene chains. It was then first industrially synthesized by accident in 1933 by applying extremely high pressure to ethylene and benzaldehyde. Over the years, development of polyethylene has increased due to the additions of catalyst. This makes ethylene polymerization possible at lower temperatures and pressures.1 Polyethylene is a polymer that is made of a long chain of CH2 monomers bonded together....   [tags: Polymer Plastic]
:: 8 Works Cited
1414 words
(4 pages)
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Stephanie Kwolek's Discovery of Kevlar - ... Nylon and polyester became available for human production of fibers in the late 20th century. They used to trim the fiber at its edge back in their time, but they need to reach a maximum of strength and an initial value. In order for that to achieve, the Kevlar molecules should have an extended set of figures and almost supreme clear order. With these bendable molecules such as nylon, this can only be made by mechanically pulled after the rotation process. Scientist discovered, in the 1965 at Du Pont, a new way of making nearly perfect longer polymer chain....   [tags: molecules, polymer, hardness] 681 words
(1.9 pages)
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Developing Microcapsules Controlled Release Delivery System - ... Best fitted Higuchi’s model assured the potential controlled gefitinib release form the microcapsules.SEM image of microcapsules was spherical. This preliminary study indicated controlled release of drug for prolong period of time. However, this study could be substantiated by the performance of in vivo. Keywords: gefitinib, poly-e-caprolactone, microcapsules, desirability, controlled release. Gefitinib is an anilinoquinazoline under the chemical name 4-Quinazolinamine, N-(3-chloro-4-fluorophenyl)-7-methoxy-6-[3-4-morpholin) propoxy] and available as IRESSA® a film-coated tablet containing 250 mg of gefitinib for daily oral administration [1]....   [tags: concentration, polymer, gefitinib] 695 words
(2 pages)
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Mechanical Properties of Carbon Nanotubes - ... First experimental attempt to measure the Young's modulus Treacy et al made use of transmission electron microscopy (TEM) to measure the mean square vibration amplitudes. The CNTs in this work were synthesized by arc discharge method. The approach of using TEM to measure the thermal oscillation amplitude has been extended to single wall as well as multi wall carbon nanotubes. Treacy et al calculated the value of Young's modulus to be of the order of 1.3 TPa. J.P. Salvetat et al made use of atomic force microscopy (AFM) to experimentally measure the Young's modulus....   [tags: polymer, strength, aircraft] 590 words
(1.7 pages)
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The Art of Water-Based Sculpting - ... After the details, I thought I was done. Regardless, the head had no hair. And so, I began adding rectangular and coned shaped strips of clay to the bare head. When I stepped back, it still felt like there was something missing; the hair was too smooth. I added more strips and snakes of clay and smoothed and blended them out, then brushing the entire head with water, leaving a smooth finish, and my very first portrait was done. I felt achieved, but not proud. The head still has many errors and could be better....   [tags: polymer clay, tools, time]
:: 16 Works Cited
1584 words
(4.5 pages)
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Polylactide - Polylactide: A New Perspective In the past decades, many polymers are non-biodegradable and require an excessive and strenuous recycling process. However one polymer, polylactide, is renovating the roles of commonly known polymers as time passes by. Polylactide has led to the introduction of other possible ways to create plastics that are more environmental friendly to the community. With this sole introduction, polymers in petrochemical-derived products are greatly affected in that they are no longer an extreme threat to the atmosphere, which is something very crucial for a future healthy planet environment....   [tags: Polymer Plastic Environment Biodegradable]
:: 3 Works Cited
1613 words
(4.6 pages)
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Helping Adult Hypertenstive Patients with Difficulty Swallowing - ... The results: The mean production yield of BH-SDs was 93.50 ± 0.39 %. The tablets demonstrated a hardness of 2-5 N, friability 0.04-0.56% and disintegration time of 67 ± 1.54 sec. The formulations were subjected to accelerated stability study as per ICH guidelines and were found to be stable after three weeks at 60 °C and 75 % R.H. Conclusion: Based on The present study; the suggested FDTs (Ta1) which delivers a solid dispersions' 10 mg BH using HPMC and EC in 1:1 ratio showed an extended effect in lowering the blood pressure and decrease the disintegrating time lesser than commercial oral tablets....   [tags: disintegrating tablets, polymer, blood pressure] 549 words
(1.6 pages)
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Chemistry of PNA Peptide Nucleic Acid - Abstract For this report I chose to study PNA, or peptide nucleic acid, a biological polymer that was related to the biomedical field of research. I was very interested in this synthesized molecule because of its inimitable and remarkable properties, comparatively to other nucleic acids such as the more commonly known DNA, or deoxyribonucleic acid, and RNA, or ribonucleic acid. I also wanted to understand its uses and possible uses in everyday life. My main goal was to learn about the structure, significance, and clinical applications of PNA....   [tags: Biology Polymer Medical Biomedical]
:: 9 Works Cited
1435 words
(4.1 pages)
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Natural and Sythetic Fibers in Clothing - ... Cellulose is found often times in the stems and leaves in plants. It is very sturdy in clothes because of the way it bonds. What makes cellulose so strong is the hydrogen-oxygen bonds, called hydrogen bonding. The hydrogen and the oxygen act as either end of a magnet, attracting each other ("Cellulose"). They can be stretched and pulled but they also join back together ("Polymers in Textile Fibers"). Examples of natural fibers containing cellulose that are often used in clothing are cotton and flax....   [tags: cellulose, molecular structure, environment] 1142 words
(3.3 pages)
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Biopolymers As a Contemporary Packaging Materials - INTRODUCTION In conditions of lack of natural enemies, also as exponential scientific, technical and technological growth, some problems occurred that human kind wasn’t face earlier. With some actions that are taken, humans have succeeded to affect the ecosystem, unfortunately this effect was basically negative, and is manifested trough the climate changes or a nonrenewable resource waste. All the needs of contemporary society, such as food, fuel, energy and materials, mostly depends on energy sources produced from nonrenewable resources that originates from fossil fuels, while the same time a total quantity of waste, that jeopardizes an ecosystem, increases (Sudesh & Iwata, 2008)....   [tags: Sustainable Development, Technological Growth]
:: 12 Works Cited
1514 words
(4.3 pages)
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Polymerization of Soybean Oil with Superacids - ... Protonic acids were investigated as to their role in polymerization. The mech-anism of the polymerization termination and its specification is disclosed in the article. Principles of Polymerization (16) provide a necessary insight into the general pro-cess of the polymerization. The work discloses different variants of the practical use of polymeric structures in industry, household, and many other spheres of human life. Moreover, the polymer chemistry is reviewed from the perspective of innovations, since it is stated that modern application of the polymers is far from complete....   [tags: dimer acids, dimer esters] 808 words
(2.3 pages)
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Taking a Look at DaunoXome - ... 2. Local chemotherapy The drug becomes more effective when targeted directly to or near around , its targeted tissue and much higher local drug concentrations can be achieved at the target. Polymers like polyanhydrides in the form of wafers are used to deliver drugs like carmustine (BCNU) for treating brain cancer. In this system of treatment, the maximum possible portion of tumor is resected by the polymer drug and wafer is placed at the position of tumor resection cavity. The remaining tumor is destroyed by the drug slowly in about three months....   [tags: medical drug analysis] 789 words
(2.3 pages)
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High Technology Swimwear - High Technology Swimwear Product application: How does a swimmer improve the speed in the water. The answer may be that do more practice. However with the development of the technology, there is one thing that has totally changed that mindset forever, that is the high-technology swimwear. The high-technology swimwear is designed and manufactured for swimmers to swim faster in high competitive swimming sports. Some studies showed that wearing high-technology swimsuit can reduce the drag up to 4% and even increase the speed by 3% to 7%....   [tags: fastskin wear, material]
:: 4 Works Cited
933 words
(2.7 pages)
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Polystyrene - The Present and Future of Polystyrene Last year, the curbside recycling in my hometown made several changes to their program. Such changes included an increase in the amount of recycled materials each household could put every week, as well an increase in the frequency of collections. Perhaps the most welcome change for my family was the new ability to recycle all plastics. Although we had never produced a titanic amount of plastic waste, we still felt as though this allowed us to better do our part for the environment....   [tags: Polymer Plastic Environment Biodegradable]
:: 4 Works Cited
1350 words
(3.9 pages)
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Radiation Pressure Effect on Polymerization Reactions - A laser trap, or an optical trap, is created by tightly focusing a laser beam with an objective lens of high numerical aperture (NA).1 The trap is formed at the focal point of the objective, which is able to hold a small particle at its center. In other words, a dielectric particle near the focus will experience a force due to the transfer of momentum from the scattering of incident photons. The resulting optical force has two components: a scattering force in the direction of light propagation and a gradient force in the direction of the spatial light gradient....   [tags: Laser Beams, Chemistry, Molecules]
:: 16 Works Cited
2123 words
(6.1 pages)
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Drying Paint: Latex Paint - This report deals with the drying of paint, with the main focus on latex paint. Evaporation and polymerisation are the two main processes in drying paint. These are described and the effects that the environment has on evaporation is discussed. Furthermore, an attempt was made to create a theoretical model to predict the evaporation of paint and an experiment was carried out to test this model. Several plates were prepared with different mixtures and two were coated in paint. The experimental data of the evaporation of water agrees with the theoretical model....   [tags: physical, chemical drying]
:: 5 Works Cited
1106 words
(3.2 pages)
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Industrial Production of PTFE - PTFE or Telfron is a common commercial organic fluoropolymer which is obtained by the polymerization of tetrafluoroethylene. It was first synthesized by Roy Plunkett accidentally in New Jersey in 1938 (Plunkett, R. J., 1987). It gradually becomes as an important industrial material for its extraordinary properties of high corrosion resistance, good electrical insulation, good heat insulation and low frictional coefficient. Due to those properties it is widely used as seals in chemical processing sector, and tubing or piping for laboratory uses....   [tags: Chemistry Science]
:: 21 Works Cited
1984 words
(5.7 pages)
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Effect of monomer modification on the physico-chemical properties, degradation and in vitro biocompatibility of polyester bioelastomers - A careful selection of monomers for biomaterial syntheses is essential for determining and controlling the functionality and biocompatibility of the biomaterials to be produced. Synthetic polyester elastomers based on molecules that are endogenous to the human metabolism have been designed [1]. In earlier studies, several investigators have reported elastic polyesters based on citric acid, in particular polyoctanediol citrate (POC) [2], poly(alkenylene maleate citrate) [3], poly(xylitol-co-citrate) [4] and poly(mannitol citric dicarboxylate) [5]....   [tags: Copolyesters, synthesized, Research]
:: 24 Works Cited
2036 words
(5.8 pages)
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The Chemistry of Painting Cars - The Chemistry of Painting Cars It is necessary to paint cars because the paint protects the steel of the car from corrosion, paint fills and smooths out any imperfections in the steel surface and it provides a durable, decorative, glossy appearance. If rusting continually takes place the car becomes unsafe. When water and oxygen come in contact with the metal of the car surface, several redox reactions happen. The oxygen is reduced to hydroxide ions and iron is oxidized to Fe2+ ions which pass into solution....   [tags: Papers] 1045 words
(3 pages)
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Organic Polymeric Materials Used in Implants - Polymers are made of large molecules that consist of a many monomers fused together through chemical bonds to make a strong material. Certain polymers are made of different chemical compositions of different molecular weights, crystallization, different degrees of hydrophobic characteristics, and heating transformations. Polymer materials are utilized for their slow degradable capabilities, ability to influence new formation of bone tissue, and contain porosity for cells to latch onto and utilize....   [tags: Physics ]
:: 1 Works Cited
2362 words
(6.7 pages)
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The Future of Biomaterials - The field of biomaterials has been growing forever. It has become more and more advanced over the years, and it is just going to keep growing. There are many uses for it now, such as creating fake skin, making new forms of contact lenses, creating stronger valves that come in and out of the heart, etc. This is an area where so much can be done in the years to come, such as making lives better for some people, finding a cure for devastating diseases like cancer, and most importantly saving people’s lives....   [tags: engineering, organ, tissue, market]
:: 6 Works Cited
1322 words
(3.8 pages)
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Does the Use of Fur in Fashion Need to Stop, or Does the Fur Trade Serve a Need? - ... There is an another way to wear fur. That another way is fake fur. Fake fur; a type of textile fabric fashioned to simulate genuine animal fur. Fake fur is made out of varies of raw materials, the fibers are composed of polymers, including acrylics, mod acrylics, blends of polymers. These acrylic polymers are made from chemicals derived from coal, air, water, petroleum, and limestone. These variety of raw materials in theses fur are very useful against attraction of insects, and have a very low moisture making it o dry up very quickly....   [tags: PETA, faut fur, fashion industry]
:: 4 Works Cited
972 words
(2.8 pages)
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Replacing Synthetic Plastic With Bacterial Polyhydroxyalkanote - Bacterial polyhydroxyalkanote (PHA) is a good candidate to replace synthetic plastic due to its biodegradability. The main factor that hampered the commercialization of PHA is the high production cost with the recovery processes accounting for the most. The present study suggests a novel biological recovery method of polyhydroxybutyrate (PHB) from Cupriavidus necator H16. The PHA granules have been extracted without the help of any solvent or chemicals. The lyophilized cells were used protein source for the laboratory rats and simultaneously recovered the PHB granules excreted in the faeces....   [tags: Biotechnology] 2359 words
(6.7 pages)
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Oil and Plastics: The Use of Fractional Distillation in Oil Refinery - ... They can be reused much more efficiency, which gives them a much more clear advantage. Biodegradable plastics are made from biomass, which is very renewable resource. Biomass includes grass, trees and all organic material that decomposes. This probably includes animal fat, meat and some tissues. Biodegradable plastics take much less time to break down after being used, if they haven’t been recycled, of course. this means that it will get absorbed into the earth and there will no longer be plastics dominating landscapes....   [tags: chemico-technical products, manufacture] 1590 words
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Utilizing Supramolecular Interactions Toward the Design of New Stimuli-Responsive Materials - The ability to utilize supramolecular interactions1 toward the design of new stimuli-responsive materials has gained a great amount of interest in recent years.2 For example, main-chain supramolecular polymers, whose polymer backbone consists of both covalent bonds and non-covalent interactions, can result in large (e.g. mechanical) responses to small changes in the environment. 3 Reversible metal–ligand coordination is one class of non-covalent interaction that has been widely utilized to access main-chain supramolecular polymers.4 Most of these metallosupramolecular polymers rely on ligand coordination with transition metal ions....   [tags: Engineering] 1159 words
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Crude Oil and Hydrocarbons - Crude Oil and Hydrocarbons Petroleum, also known as crude oil is formed from fossilized remains of marine plants and animals that settled on the sea floor millions of years ago. Petroleum consists of a complex mixture of hydrocarbons molecules including parrafins, aromatics, napthenes/ cycloalkanes, alkenes and alkynes. Hydrocarbons are molecules that contain hydrogen and carbon atoms that form various structures from straight chains to branching chains and rings. Hydrocarbons with low molecular weights, such as propane (C3H8) are in a gaseous form....   [tags: Environment, fossil fuels]
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Oil & Plastics and Sustainability - How is this method used to help produce chemico-technical products (fuels,solvents, etc). The fractional distillation is when the crude oil get separated to a different parts, called fractions. The fractionating column is used to separate the crude oil, at the beginning the crude oil is heated at the bottom, that makes the hydrocarbon molecules to act very fast and separates from each other. Because the fractionating column have different boiling points, the consist in the crude oil allows to be separated using fractional distillation....   [tags: biodegradable plastic,PVC,fractional distillation]
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Application Essay for the Ph.D Program in Chemistry - ... (more) How did you get interested in your field. Throughout my life I have always been curious about the world around me and I strove to understand it at a deeper level. Driven by my curiosity, I took college accredited science courses in high school, and I enjoyed the hands-on work in my chemistry class and was drawn to how fundamental it is to my everyday life. For much of my undergraduate career I have participated in research, and though the work was challenging, I enjoyed the diversity of the work and furthering my understanding....   [tags: education, chemistry, undergraduate] 825 words
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Tissue Engineering or Regnerative Medicine - ... Scaffolding usually provides one of the following (Berthiaume et al., 2011): a. Cell attachment and possibly migration b. Retention and presentation of biochemical factors c. Porous environment for diffusion of nutrients, metabolic by products and waste d. Mechanical rigidity or flexibility Some methods used in regenerative medicine do not involve utilising living cells prior to implantation of the scaffold/material. These methods rely on the host cells to migrate into the scaffolds. Cells exhibit the ability for directional migration, and this is dependent on the concentration gradient of bioactive signalling molecules present....   [tags: bone, biomedical factors, synthetic] 704 words
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The Melt Flow Rate of Different Polymeric Materials - ... 17) Step 1-14 was repeated for other polymeric materials. Results: Table 1.1: Condition set for each polymeric material Table 1.2: MFR for each polymeric materials in actual and weighted reading Polymeric materials Melt flow rate (g/10 min) Weight of the plastic material (g/min) g/10 min 1st 2nd 3rd Average 1st 2nd 3rd Average Polyethylene (PE) 1.34 1.375 1.359 1.358 0.1005 0.1065 0.0875 0.0982 0.982 Polypropylene (PP) 3.998 3.935 3.994 3.976 0.4102 0.4113 0.4077 0.4097 4.097 Polystyrene (PS) 4.233 4.315 4.315 4.288 0.3728 0.3688 0.3739 0.3718 3.718 PMMA 0.996 0.995 1.039 1.01 0.1056 0.0987 0.099 0.1011 1.011 PP + 10% fibre 2.076 2.098 2.119 2.098 0.2113 0.2035 0.2006 0.2051 2.051 Ta...   [tags: operating procedure, melt flow index]
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Formulating Nitrite Butadiene Rubber High Density Polyethylene Blends by Using Industrial Blends and Compatibilized Chloroprene Rubber - ... Eventually, when mixing finished, the compounds were kept at room temperature for as minimum 24 hours before their cure characteristics were measured. Test specimens were obtained by compression moulding at 160° C and a pressure of 20 MPa for the respective optimum cure time (t90) obtained from rheographs. After curing, the vulcanized sheet was taken out of the mold and immediately cooled under tap to stop further curing. All samples were cured at this temperature and stored in a cool dark place for 24 hours....   [tags: mechanical properties, thermal ageing] 2453 words
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Plastics - I want to say one word to you. Yes sir. Are you listening . Yes sir, I am. PLASTICS . - The Graduate (1967) 1. Definition of Plastics Plastics can be defined as used materials which are primarily based on two materials, polymers and prepolymers (Elias, 1993). However, the previously mentioned definition suffers from a serious weakness as it does not explain the basic method of how plastics are made. A better definition of plastics is that they are “synthetic materials composed of a series or chain of molecules which, when heat or pressure is applied, can be formed into desired shapes” (Lincoln et al....   [tags: Conservation ] 2461 words
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The Structure and Function of Carbohydrates - The Structure and Function of Carbohydrates Large biological molecules are called macromolecules, there are giant molecules (polymers) made up of repeating units (monomers). Carbohydrates are one of the main classes of biological molecules. Macromolecule units (monomers) are joined together by condensation reactions and hydrolysis reactions split macromolecules down into their individual units. Carbohydrates are molecules that contain elements of carbon, hydrogen, and oxygen. Carbohydrates have a 2:1 hydrogen to oxygen ratio, there are twice as many hydrogen atoms as oxygen atoms (the same proportion as in water)....   [tags: Papers] 590 words
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Percutaneous Transluminal Coronary Angioplasty - Introduction In 1977, percutaneous transluminal coronary angioplasty (PTCA) was introduced to dilate narrow coronary arteries. Over the years, the development of the procedure knocked down major anatomical obstacles. Typically the procedure involves a small incision into the leg, a catheter is inserted through the groin vein and is then steered to the blocked coronary vessel via a guide wire. On the tip of the catheter is a deflated balloon. Once at the congested region of the artery the balloon is inflated, causing plaque to compress against the artery wall, dilating the artery and restoring blood to flow [1]....   [tags: Anatomy, Coronary Arteries] 2255 words
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Transmissible Spongiform Encephalopathies (TSEs) - ... PrPC expression is indispensable for prion-induced neurotoxicity, implying PrPC could be a receptor for prions to trigger detrimental signaling. The scenario could be broader. It is reported that PrPC transducers the synaptic toxicity of amyloid-β (Aβ) oligomers in vitro and in Aβ transgenic mice. Moreover, different anti-PrP antibodies or their antigen-binding fragments that disrupt the PrP–Aβ interaction were able to block the Aβ-mediated disruption of synaptic plasticity. These findings were deemed exciting because they suggest the involvement of PrPC in Alzheimer's disease (AD) pathogenesis....   [tags: prion, disease, disorders, loss, response] 1094 words
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Flame-Retardant Compounds Increase Smoke Production - ... It is important to understand that the species formed during pyrolysis are a major factor in smoke formation. The smoke production is dependent on the burning conditions, the amount and chemical structure of polymeric material burnt. In general, polymers that are largely aliphatic and contain oxygen have a tendency of low smoke production [47]. On the other hand, polymers containing aromatic groups generate high amount of smoke on decomposition. Poly (vinyl chloride) and poly (vinylidene chloride) are exceptions, although they contain aromatic groups resulting in little smoke formation on decomposition....   [tags: combustion, cotton, decomposition] 561 words
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Clay Loading and Dispersion Effects on the Rheological Properties of Unsaturated Polyester Nanocomposites - Clay Loading and Dispersion Effects on the Rheological Properties of Unsaturated Polyester Nanocomposites The objective of this work is to characterize the influence of clay loading and dispersion effects on the rheological properties of unsaturated polyester composites. Toughened unsaturated polyester (UPE) composites were synthesized by the blending of delaminated clay with unsaturated polyester. Rheological behavior is shown to be strongly influenced by clay loading and the extent of clay dispersion in the polymer matrix....   [tags: essays research papers] 2008 words
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Common Use of Ceramics in Dental and Orthopaedic Applications - ... Carbons were chosen due to their resistance to degradation and low wear rate (Helmus et al, 2008). Pyrolytic carbon is used preferably in this application rather than other carbons because pyrolytic carbon is highly resistant to blood clotting, biocompatible in that it causes little damage to blood cells, strong, durable and has low wear rates. All of these mechanical properties are due to the unique microstructure of this specific carbon which is similar but subtly different to graphite. Graphite has hexagonal arrays of stacked carbon atoms and atoms in every other layer are coincident and bonded by Van-der-Waals bonds....   [tags: dentures, prosthesis, metals ] 1498 words
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A Model-Based Methodology for Spray Drying Process Development - A Model- Based Methodology for Spray Drying Process Development Journal of Pharmaceutical Innovation September 2009 Volume 4 Issue 3 This paper describes a novel methodology based on fundamental engineering models as well as process characterization techniques to ensure that the spray drying process is efficient and requires minimal time and API. Spray drying methods use rapid drying kinetics to produce solid amorphous dispersions, excipients, and encapsulation. Spray drying dispersions are used to increase bioavailability of poorly soluble APIs....   [tags: engineering models, process techniques]
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Malnutrition is Caused by an Unbalanced Diet - A balanced diet is when you eat a range of food and drinks from all the different groups but at the same time maintaining and taking care of what you eat. Especially staying away as much as possible from salt, trans fats etc. Malnutrition is caused by an unbalanced diet due to having too much or too little nutrients (PubMedHealth.com). Under nutrition is when the body isn’t given enough calories, due to the person’s diet, and because they don’t utilize the food properly as they should. Over nutrition, is when the person consumes a lot more proteins and calories then they should....   [tags: energy, body mass index]
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Protecting Those at War: The Bulletproof Vest - ... They would have to cower away from their enemy or die. Today we see just the opposite. The first bulletproof vest was made in the United States was of silk material. The project came to attention after the assassination of President McKinley in 1901. The vests were effective against low-velocity bullets, but not against the new generation of ammunition. This, along with the high price of the silk material made the new invention hard to manufacture. The next type of bulletproof vest was used during World War II with ballistic nylon the vest was known as a flack jacket....   [tags: chemistry contributing to warfare] 863 words
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Commonly Used Composites and Their Characteristics - ... This adjustment is done by tweaking the microstructure of the materials by changing the state, shape, amount and distribution of the filling, which is also called as the reinforcing phase. Instead of restricting this tweaking process within a certain material class, the idea is being implementing in cross-material classes as well. Ceramics powder can be added to plastics to make hard and fireproof polymers. Ceramic powder when mixed with metals, gives cermets, which are used in tips of metal cutting tools....   [tags: material, fibrous, construction] 705 words
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The Progession of Man-Made Organs - Beginning in 1980, scientists have been trying to find a solution to the progressing problem of organ transplants. Many concerns come with transplanting an organ into the body; the two major issues are a lack of donors and a high rejection rate. A proposed solution to the rising issue is growing artificial organs in a lab. As technology advances, researchers are becoming increasingly closer to successfully growing a functioning organ that can be transplanted into a human body. When researchers first began the climb to successfully grow internal organs in a lab, many barriers needed to be overcome; the first being growing ticker tissues....   [tags: Medical Innovation, 3D Printing]
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Biology Answers to Quiz: Cells - ... Osmosis is when something crosses a permeable membrane from areas of low concentration to high concentration. This usually involves water of some sort. Active Transport is when a substance uses energy to move across a semi permeable membrane with the help of a protein. The function of the kidneys uses each of these processes it uses active transport to absorb amino acids and salts by the nephron in the kidney. The kidney also uses osmosis to absorb water into the tubules in the nephron. Finally, the kidney uses diffusion in the ascending portion of the loop of henle to let out salts....   [tags: Cellulose, Difussion, ATP] 532 words
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Thermography: How Does It Work? - ... This technology can even be used to detect poor connections and internal damage in circuits, which can potentially lead to a fire starting. Furthermore this technique has a number of applications in condition assessment of structures, locating the source of distress, identifying moisture ingress and flow through pipes and assessment of damage potential in concrete and masonry structures. Thermal images are also widely used in computer systems where it can be used to locate components of excessive heat generation....   [tags: anomalies in machines, infrared cameras] 586 words
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Bisphenol A - In society, Bisphenol A is also known as BPA it’s important and relevant in some areas like in cars and medical equipments and not so important for the human body. BPA is mostly link to metal cans. The purpose of this paper is to discuss the molecular process, the real world applications, and the advantages and disadvantages of Bisphenol A. Bisphenol A has deep connection in the can making industry, in the NACAR business and the history of Bisphenol A. Bisphenol A is a chemical building block that is used primarily to make polycarbonate plastics and epoxy resins....   [tags: Chemistry, Polycarbonate Plastics] 1986 words
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ft.lauderdale high AP bio project - 2) LEVEL 1 - Cells Are the basic unit of structure and function in living things.May serve a specific function within the organism Examples- blood cells, nerve cells, bone cells, etc. tissue LEVEL 2 - Tissues Made up of cells that are similar in structure and function and which work together to perform a specific activity Examples - blood, nervous, bone, etc. Humans have 4 basic tissues: connective, epithelial, muscle, and nerve. LEVEL 3 - Organs Made up of tissues that work together to perform a specific activity Examples - heart, brain, skin, etc....   [tags: essays research papers] 2086 words
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Replacement of Damaged Human Bone - ... Generally, a perfect tissue-engineered composite should assure several necessary criteria. It should be: biocompatible with biomimetic nanosurface structure and chemistry to minimize the local tissue response while maximizing cell growth and tissue integration; porous to allow cell passage and well-organized exchange of nutrients and wastes; biodegradable with a favorable degradation rate, allowing the composite to provide structural support for initial cell growth and then gradually degrade after new tissue formation; and possess appropriate mechanical properties to support tissue growth under native mechanical loads.[2,5–7]....   [tags: nanotechnology, tissue, organic] 637 words
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Characteristic of Organic Compounds - What are organic compounds, you may ask. Well organic compounds are compounds that always contain carbon, or any compound that contains a carbon atom. But some describe organic compounds as any of a large class of chemical compounds in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly are hydrogen, oxygen, and nitrogen. But there are a few exceptions to this organic rule, which are carbon monoxide, carbonates, carbon dioxide, cyanides, cyanates, carbides, and thyocyanates, which are all considered inorganic....   [tags: Carbon Atoms, Chemical Compounds]
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Oceanic Gyres and Its Effect on the Environment - ... The answer is simple, in the ocean. Charles Moore claims “Eighty percent of mid-ocean flotsams has originally been discarded on land” ( Weisman.) Moore estimated that the “Great Pacific Garbage Patch” alone has roughly three million tons of plastic waste in it, and has grown by 100 percent over the past 40 years. It’s crazy to think we are polluting the only home humans have; filling the oceans of the world carelessly with waste. Plastics are a product that was intended to stay on land; although they have been entering oceans at a startling rate, affecting the environment dramatically....   [tags: currents, earth, rotates, sun, wind, temperatures] 863 words
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History of Plastics - ... The results of the survey show that many try their best to be environmentally conscious but did not always realise that their actions were not reflecting their intentions and could potentially be doing more harm than good. Chemistry Connections Polymers are molecules consisting of many smaller repeating monomer units. Plastic such as plastic water bottles are made from a simple addition polymer, polyethene (van Kessel et al., 2003). There are many types of addition polymers such as polyethene terephthalate or PET and polypropene....   [tags: biodegradeable, economy, environment] 1286 words
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An Exploration of Molding - DEFINITION Molding can be defined as the process of manufacturing by giving a particular shape to a liquid or a pliable raw material using a rigid frame called a mould. A mould is a hollow box which is made from a pattern. While working a mould is filled with raw material like plastic ,glass, metal etc. The liquid cools down into the mould and gets harder adopting its shape. TYPES OF MOLDING • Injection molding • Foam molding • Extrusion molding • Compression molding • Blow molding • Matrix molding • Plastic molding Vacuum plus assist molding INJECTION MOLDING DEFINITION It is a process for giving a particular image to a pliable raw...   [tags: Injection molding process]
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The Body Worlds Exhibition by Gunther von Hagens - The Body Worlds Exhibition by Gunther von Hagens "A quite extraordinary experience, slightly unnerving, but I do feel an enormous respect now for our bodies and the way they function. Thank you!" "I am now able to understand my body in a much better way. Congratulations on such a sensational exhibition and a very enlightening tour. I hope that this exhibition will gain more acceptance." These are two opinions about the Body Worlds exhibition, which is currently in London....   [tags: Papers] 1303 words
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