Bulletproof Vests/shields Prepared From Composite Material Based On Strong Polyamide Fibers And Epoxy Resin

Fiber Reinforced Plastics (FRP) have arisen as a main class of tactual materials having high strength and light weight implemented in a large scale of different applications. This study performs a comparison between the enhanced propidines of Kevlar 49 fiber and Twaron CT 704 reinforced with epoxy resin to obtain an efficient, light weight and slim body m o r capable of resisting high speed projectiles (9 mm bullets). Reinforcing the fabrics adds extra strength to the fabrics instead of using several unreinforced fabrics which increases the weight thickness and the cost of the final product. The response of the prepared composite material based on the two different fibers was studied by using a test barrel for the penetration test. In addition. indentation test is also au lied to compare between the mechanical properties of both laminates and determine which fabric is better for life protection application. The final results showed that using the technique of reinforcing the fabrics specially Twaron is much better where the final bulletproof shield has a smaller number of layers and was found lighter by 40% than those made by Kevlar

Synthesis and Characterization of Chitosan Based Catalyst for Catalysis Applications

In this research, chitosan-based catalyst synthesis and characterization was investigated for different application in catalysis as chitosan-based catalyst was combined with metal oxides in order to be used in dye removal of methyl orange (MO). Diluted acetic acid was used to dissolve chitosan then different percentages for metallic ions were mixed with diluted chitosan and then, 500 µL were added to the sample to reduce the metal salts then, microwave was used to heat the mixture for 5 minutes and then dried at 80-100 °C. Finally, X- ray diffraction was used to confirm the catalyst prepared. The aim of this research is to investigate and explore the feasibility of chitosan/metallic ions composite for removing MO from aqueous solutions. The influence of several operating parameters for adsorption of MO, such as contact time, temperature and ph

Water Absorption Enhancement Of Sodium Poly Acrylate And Poly(2-Acrylamido-2-Methylpropane Sulphonic Acid) Based Hydrogel Mixtures

Introduction: Hydrogels are hydrophilic polymers which are cross-linked to form three-dimensional structures, which can absorb, swell and retain huge amounts of water or aqueous fluids. Objective: This paper reports the preparation and characterization of Poly (2-Acrylamido-2-Methylpropane Sulphonic Acid) (PAMPS) hydrogel with different crosslinking intensities. Methodology: 2-Acrylamido-2-methylpropane sulfonic acid (AMPS) monomer was purchased from Alfa Aesar Company as reagent grade. It was used as received (\u3e98% purity) without any further purification. PAMPS hydrogel was prepared by free radical crosslinking solution polymerization of AMPS in water at room temperature under a nitrogen blanket in cylindrical glass tubes. The characteristics of the obtained PAMPS hydrogel were compared with those of commercial sodium polyacrylates hydrogel. Results: It was found that decreasing the crosslinker weight improved the absorbance capacity but to a limit. The suggested reasons were discussed. The mixture showed higher absorbance rate than PAMPS, and bigger absorbance capacity than sodium polyacrylates. Conclusion: This paper investigates the effect of crosslinker ratio on the swelling capacity of PAMPS. It was found that as the crosslinking ratio decreases, the porosity of the hydrogel increases, thus improving the swelling capacity

Mechanical characteristics for different composite materials based on commercial epoxy resins and different fillers

In this research, different compositions of composite materials based on epoxy resin and four different fillers were prepared and all mechanical characteristics were investigated to reach a composite material having high resistance to impact by high kinetics energy projectiles which is required in the production of bulletproof jackets and also in cassette shields of explosive reactive armors to protect tanks. This composite material is usually applied as layers with other polymeric fibers such as carbon fibers and Kevlar (polyamide) sheets. The used epoxy consists of Epon as linear epoxy and tertiary amine as hardener. The used fillers are carbon black, magnesium carbonate, wood flour and sand. The pure thermoset epoxy (without filler) which gives the highest different mechanical properties is based on 10:5 by weight (linear Epon/Hardener). The composition which gave the highest resistance to impact by high kinetics energy projectiles was epoxy resin containing 15% by weight wood floor where the resistance to impact was increased by 32% when compared with the pure epoxy

Synthesis And Characterization Of PVP Based Catalysts For Selected Application In Catalysis

This research aims to study the catalyst activity in specific reactions and the characteristics of the catalyst in order to optimize its performance. This research investigates PVP based catalysts and their properties and applications. PVP was prepared in combination with different metal oxides in order to be tested for different catalytic applications including dye removal. Methyl orange was used as a dye and different concentrations were tested against different metallic ions in order to optimize the catalyst for being used in dye removal applications. Spectrophotometer was used to calculate the concentration of the dye before and after catalyst exposure and investigate the relation between contact time and concentrations. Applying different contact time to the same weight percent of PVP based catalyst with metallic ions revealed that increasing the contact time with a good shaking lead to decrease in the concentration of the dye mixed with the sample. The tests showed that the mixture between PVP and Nickel has the best dye removal within the other metal ions (copper and ferric) as well it showed that ferric has the least effect on dye removal. Wide angle x-ray diffraction (WA-XRD) was applied to different sample copper with PVP and ferric with PVP

Microwave Assisted Synthesis Of Binary Metallic Oxides For Catalysis Applications

Herein, versatile, and reproducible method to prepare binary metal oxides via microwave assisted synthesis. Catalysts are substances that basically speeds up chemical reactions. Ideally, bonds are formed between the catalysts and the reactants. Also, catalysts permit formation of products from the reactants. These formed products, splits off the catalyst without affecting or changing it. Catalytic kinetics studies the correlate chemical reaction rate with some properties of reactants and/or products for instance, temperature, concentration and pressure. The aim of the project is to prepare pure and bi-metal iron-based catalyst by co-precipitation method and to characterize the prepared sample using X-ray diffraction. Metal oxides nanoparticles is a field of interest in catalysis, such that these oxides are used to oxidize carbon monoxide. The samples were prepared through co-precipitation method in laboratory scale. The metals used was copper, iron and cobalt. After preparing pure sample of each metal a mix of two metals were introduced in different ratios. The samples were characterized via X-ray diffraction (XRD) and then the results were compared to exist data introduced from others research, the prepared samples XRD was having a great matching with the data retrieved from internet and we found that the metal could exist in two form of oxides and even could exist as pure metal. Each peak in the XRD figure could indicate one or more phase of the metal

Novel ethyl 1,5-disubstituted-1H-pyrazole-3-carboxylates as a new class of antimicrobial agents

A series of pyrazole derivatives 9-22 were designed and synthesized. All the newly synthesized compounds were assayed for their antimicrobial activity against the Gram-positive bacteria Staphyllococcus aureus and Bacillius subtilis and the Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa, in addition to the fungi organisms, Candida albicans, C. parapsilosis and C. tropicalis. Ethyl 5-(2,5-dimethylthiophen-3-yl)-1-phenyl-1H-pyrazole-3-carboxylate (21) (MICE.coli =0.038 µmol mL–1, MICP. aerug = 0.067 µmol mL–1) is nearly as active as ampicillin (MIC = 0.033 and 0.067 µmol mL–1, respectively). Ethyl 5-(4-bromo-2-chlorophenyl)-1-phenyl-1H-pyrazole-3-carboxylate (16) (MIC = 0.015 µmol mL–1) is more active than fluconazole (0.020 µmol mL–1) as a reference drug against C. parapsilosis

Phytochemical composition and antimicrobial properties of Markhamia platycalyx (Baker) Sprague leaf

Purpose: To isolate new antimicrobial agents from the leaves of Markhamia platycalyx (Baker) Sprague and assess their phytochemical characteristics and antimicrobial activity. Methods: Different chromatographic and spectroscopic techniques (NMR and ESI-MS) were applied for the identification of antimicrobial compounds. Agar-well diffusion technique was used for determination of antimicrobial activity. Anti-HCV effects were investigated using VITROS Anti-HCV assay. Results: Eighteen compounds were isolated for the first time from this genus. These were phytol, noctacosanoic acid (OCTA), tormentic acid and β-sitosterol-3-O-(6'-O-heptadecanoyl)-β-Dglucopyranoside. The other compounds were β-sitosterol, ursolic acid (URSA), oleanolic acids, pomolic acid (POMA), 2-epi-tormentic and β-sitosterol-3-O-β-D-glucopyranoside. However, stigmasterol and acteoside, which were seen in previous studies, were also present. Total ethanol extract (TEE) was the most effective against Escherichia coli, with the lowest minimum inhibitory concentration (MIC) of 1.0 µg/mL. Acteoside, URSA and 2-epi-tormentic acid showed the highest antibacterial effect on Pseudomonas aeruginosa while 2-epi-tormentic acid and acteoside produced the least MIC on Candida glabrata. These effects were superior to those produced by standard antibiotics. However, 2-epitormentic acid and β-sitosterol-3-O-β-D-glucopyranoside had no anti-HCV effects. Conclusion: Due to the good antimicrobial properties of Markhamia platycalyx, it is a potential source of new antimicrobial drugs

An efficient green ionic liquid for the corrosion inhibition of reinforcement steel in neutral and alkaline highly saline simulated concrete pore solutions

The effect of the green ionic liquid compound, Quaternium-32 (Q-32), on the corrosion inhibition performance of reinforcement steel, in a simulated concrete pore solution, was investigated at different temperatures and pH values, using electrochemical impedance spectroscopy (EIS). The inhibition efficiency was improved as the concentration of Q-32 and pH values were increased. However, it decreased as the temperature was raised. A Q-32 concentration of 20 µmol L–1 exhibited a 94% inhibition efficiency at 20 °C. The adsorption isotherm was evaluated using EIS measurements, and it was found to obey the Langmuir isotherm. The surface topography was examined using an atomic force microscope and scanning electron microscope. The effect of the Q-32 concentration with the highest corrosion efficiency on the mechanical properties of the mortars was also explained by flexure and compression techniques.The authors express their gratitude to the Center for Advanced Materials at Qatar University for technical support. Additionally, the authors are grateful to Qatar University for funding this work through the QUCG-CAM-20/21-2 Grant. The publication of this article was funded by the Qatar National Library

Electrochemical and thermodynamic study on the corrosion performance of API X120 steel in 3.5% NaCl solution

The present work studied the effect of temperature on the corrosion behavior of API X120 steel in a saline solution saturated with CO2 in absence and presence of polyethyleneimine (PEI) as an environmentally safe green inhibitor. The effect of PEI on the corrosion behavior of API X120 steel was investigated using destructive and non-destructive electrochemical techniques. The overall results revealed that PEI significantly decreases the corrosion rate of API X120 steel with inhibition efficiency of 94% at a concentration of 100 μmol L−1. The adsorption isotherm, activation energy and the thermodynamic parameters were deduced from the electrochemical results. It is revealed that the adsorption of PEI on API X120 steel surface follows Langmuir adsorption isotherm adopting a Physi-chemisorption mechanism. Finally, the samples were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques to elucidate the effect of aggressiveness of corrosive media on the surface morphology and the corrosion performance of API X120 steel. The surface topography result indicates that the API X120 steel interface in PEI presence is smoother than CO2 with Cl− ions or Cl− ions only. This is attributed to the compact protective film limits the aggressive ions transfer towards the metallic surface and reduces the corrosion rate. Moreover, PEI inhibition mechanism is based on its CO2 capturing ability and the PEI adsorption on the steel surface beside the siderite layer which give the PEI molecules the ability to reduce the scale formation and increase the corrosion protection due to capturing the CO2 from the brine solution