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Influence of alkaline treatment and fiber loading on the physical and mechanical properties of kenaf/polypropylene composites for variety of applications

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Progress in natural Science:Materials International 2016年第6期26卷 657-664页

作者： Majid niaz Akhtar Abu Bakar Sulong M.K.Fadzly Radzi n.F.Ismail M.R.Raza norhamidi Muhamad Muhammad Azhar Khan Department of Physics COMSATS Institute of Information Technology Department of Mechanical and Materials Engineering Faculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia Department of Basic Sciences and Humanities Muhammad Nawaz Sharief University of Engineering and Technology(MNSUET) Department of Mechanical Engineering COMSATS Institute of Information Technology Department of Physics The Islamia University of Bahawalpur

Due to current trend and increasing interest towards natural based fiber products, Kenaf(Hibiscus cannabinus)fibers have been used for the developments of many products. Therefore, Kenaf fiber-reinforced composites have been widely used in engineering and industrial applications. The present work deals with the fabricating and characterization of untreated and treated kenaf/polypropylene(PP)-reinforced composites. Composites of PP reinforced with treated and untreated kenaf fibers were fabricated using the injection molding *** fiber loadings of 10, 20, 30, 40, 50 wt% treated and untreated kenaf composites were also prepared. Xray diffraction(XRD), scanning electron microscopy(SEM), Fourier transform infrared(FTIR) spectroscopy and thermo gravimetric analysis(TGA) were performed on the treated, untreated kenaf fibers and kenaf/PP composites. Moreover, the alkaline-treated kenaf composites exhibit better physical, morphological, and mechanical properties because of the compatibility of kenaf with PP. However, variations in tensile and flexural properties depend on treatment and kenaf fiber contents. The percentage increase in the mechanical properties of the treated kenaf/PP composites relative to that of PP was also measured. In addition, 40 wt%kenaf fiber loading resulted in higher mechanical properties. By contrast, kenaf/PP composite with 50% fiber loading was not successfully prepared because of improper mixing and the burning of kenaf fibers in the PP matrix. To conclude, 40% kenaf/PP composites with superior physical and mechanical properties may be used in variety of applications such as automotive, sports, construction, animal bedding, and mass production industries.

关键词： Kenaf composites Microstructures Physical properties Mechanical Testing Injection-molding

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numerical Solution of System of Fractional Delay Differential Equations Using Polynomial Spline Functions

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Applied Mathematics 2016年第6期7卷 518-526页

作者： Mahmoud n. Sherif Mathematics Department Faculty of Science and Education Taif University Al-Khurmah Branch Taif Saudi Arabia Mathematics Department Faculty of Science Menoufia University Shebeen ElKoom Egypt

The aim of this paper is to approximate the solution of system of fractional delay differential equations. Our technique relies on the use of suitable spline functions of polynomial form. We introduce the description of the proposed approximation method. The error analysis and stability of the method are theoretically investigated. numerical example is given to illustrate the applicability, accuracy and stability of the proposed method.

关键词： Fractional Differential Equation Spline Functions Taylor Expansion Stability

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Kinetic study and kinetic parameters of lipase-catalyzed glycerolysis of sardine oil in a homogeneous medium

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Chinese Journal of Catalysis 2016年第4期37卷 596-606页

作者： Angela García Solaesa María Teresa Sanz Sagrario Beltrán Rodrigo Melgosa 布尔戈斯大学生物技术与食品科学系(化学工程部) 西班牙布尔戈斯09001

The production of polyunsaturated fatty acids （PUFAs） concentrates by enzymatic catalysis has gained interest due to their stereospecificity and the milder conditions employed compared to the use of inorganic catalysts. The enzymatic glycerolysis of sardine oil by Lipozymeò435 to get PUFA concentrates in the forms of di‐and monoacylglycerols （DAGs, MAGs） in an optimized amount of tert‐butanol as the organic solvent was studied. First, mass transfer limitation of the reaction sys‐tem was analyzed. The effects of different operating variables such as lipase loading, temperature and feed composition were investigated. A semi‐empirical kinetic model based on the reversible elementary reactions of glycerolysis and hydrolysis of the glycerides was employed to correlate the experimental kinetic data. A molar ratio glycerol：oil of 3：1 was the optimum, which produced more than 84 wt%of MAG at 323 K. A comparison with other glycerolysis systems was performed using MAG yield, reaction rate and significance of kinetic parameters.

关键词： Lipase Glycerolysis Tert-butanol Mass transfer Kinetic model

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Antibiotic Susceptibility Patterns of Isolated Bacteria from Otitis Media in Children at Mohamed Aden Sheikh Children Teaching Hospital in Hargeisa, Somaliland

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Journal of Biosciences and Medicines 2023年第6期11卷 57-70页

作者： Saed n. Ahmed Departments of Health Services and Public Health Ministry of Health Development Hargeisa Somaliland

Background: Otitis media (OM) is a group of inflammatory diseases of the middle ear. OM is a prevailing problem among children in Hargeisa. The antibiotic susceptibility of etiologic bacteria is not investigated in Somaliland which hinders the effective treatment of OM cases in children. Objective: This study aimed at determining the etiologic bacteria and its antibiotic susceptibilities in children presenting with OM to a pediatric referral hospital in Hargeisa for the period March 2013-May 2017. Methods: A cross-sectional retrospective study was conducted on a random sample of 270 children with OM. The laboratory used standard microbiological techniques for bacterial isolation and Kirby Bauer disk diffusion method for antibiotic susceptibility testing. Data were entered and analyzed using Epi Info 7 and any associations among the study variables tested with Chi2 test with confidence level of 95% and p value of Results: The rate of bacterial isolation was 96.3%. The predominant bacterial isolate was S. aureus (31.48%) followed by P. aeruginosa (24.81%) and P. mirabilis (15.93%) respectively while the least prevalent isolates were coagulase negative Staphylococcus (1.48%), S. pyogenes (0.74%) and Enterobacter spp. (0.37%) in descending order. Age group 0 - 3, χ2 (143,270 = 223.245, p = 0.000) showed highest bacterial isolation. There was no significant relationship between bacterial isolate and gender, χ2 (11,270 = 9.2283, p = 0.6008). S. aureus showed highest sensitivity towards ciprofloxacin (85.7%), amikacin (76.5%), and gentamicin (73.8%). All isolates showed mixed resistance pattern. Conclusion: S. aureus, P. aeruginosa and P. mirabilis were the leading causative pathogens of otitis media. no association was established between isolate distribution and gender. Both the isolated gram-positive and gram-negative bacteria showed greatest sensitivity towards ciprofloxacin while the highest resistance was observed to penicillins, tetracyclines a

关键词： Otitis Media Children Etiologic Bacteria Antibiotic Susceptibility Treatment

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Fabrication and Photostability of Rhodamine-6G Gold nanoparticle Doped Polymer Optical Fiber

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Chinese Physics Letters 2013年第11期30卷 180-183页

作者： Suneetha Sebastian Ajina C C.P.G Vallabhan V.P.n.nampoori P.Radhakrishnan M.Kailasnath International School of Photonics Cochin University of Science and TechnologyCochin 22India

We report on fabrication of a rhodamine-6G-gold-nanoparticle doped polymer optical *** gold nanoparticle is synthesized directly into the monomer solution of the polymer using laser ablation synthesis in *** size of the particle is found from the transmission electron ***-6G is then mixed with the nanoparticle-monomer solution and optical characterization of the solution is *** is found that there is a pronounced quenching of fluorescence of rhodamine 6G due to fluorescence resonance energy *** monomer solution containing rhodamine 6G and gold nanoparticles is now made into a cylindrical rod and drawn into a polymer optical ***,the photostability is calculated with respect to the pure dye doped polymer optical fiber.

关键词： stability particle Rhodamine

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Life Origin in the Milky Way Galaxy: III. Spatial Distribution of Overheated Stars in the Solar neighborhood

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Journal of High Energy Physics, Gravitation and Cosmology 2024年第2期10卷 693-709页

作者： Alexander n. Safronov Obukhov Institute of Atmospheric Physics Russian Academy of Sciences Moscow Russia

A concept of ensemble averaged stellar reactors is developed to study the dynamics of processes occurring in stars, allocated in the ~200 pc solar neighborhood. According to the effective temperature value, four stellar classes are identified, for which the correlation coefficients and standard deviation are counted. The theory of the buoyancy terrestial elements is generalized to stellar systems. It was suggested that stars are over-heated due to the shift parameters of the nuclear processes occurring inside the stars, which leads to the synthesis of transuranium elements until the achievement of a critical nuclear mass and star explosion. The heavy transuranium elements sink downward and are concentrated in the stellar depth layers. The physical explanation of the existence of the critical Chandrasekhar star limit has been offered. Based on the spatial analysis of overheated stars, it was suggested that the withdrawal of the stellar reactor from the equilibrium state is a consequence of extragalactic compression inside the galaxy arm due to the arm spirality (not to be confused with the spirality of the galaxy itself).

关键词： Stellar nucleogenesis Ensemble-Averaged Stellar Reactor Overheated Stars Chandrasekhar Stellar Limit Arm Spirality

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An Accurate numerical Solution for the Modified Equal Width Wave Equation Using the Fourier Pseudo-Spectral Method

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Journal of Applied Mathematics and Physics 2016年第6期4卷 1054-1067页

作者： Hany n. Hassan Department of Basic Engineering Sciences Benha Faculty of Engineering Benha University Benha Egypt

In this study, the numerical solution for the Modified Equal Width Wave (MEW) equation is presented using Fourier spectral method that use to discretize the space variable and Leap-frog method scheme for time dependence. Test problems including the single soliton wave motion, interaction of two solitary waves and interaction of three solitary waves will use to validate the proposed method. The three invariants of the motion are evaluated to determine the conservation properties of the generated scheme. Finally, a Maxwellian initial condition pulse is then studied. The L2 and L∞ error norms are computed to study the accuracy and the simplicity of the presented method.

关键词： The Modified Equal Width Wave Equation Fourier Pseudo-Spectral Method Solitary Waves Fast Fourier Transform

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Blocking Translation of Oncogenic mRnA

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Journal of Cancer Therapy 2023年第6期14卷 233-256页

作者： Kelvin n. Christie Long Island University Post Campus Brookville USA

Double-stranded RnA-mediated interference (RnAi), antisense oligonucleotides (ASO), and ribozymes have excellent specificity to their target oncogenic mRnA. They also seem to show great promise when it comes to treating cancer. The problem is that RnAi, ASO, and ribozymes have poor stability and are constantly being degraded by nucleases. Researchers have made some efforts to increase antisense oligonucleotides’ stability by creating phospharimidate and Phosphorothioate. Currently, ribozymes, antisense oligonucleotides, and (RnAi) are the three main methods used to target RnA. These methods are currently undergoing clinical trials for the purpose of focusing on specific RnAs involved in disorders like cancer and neurodegeneration. In fact, ASOs that target amyotrophic lateral sclerosis and spinal muscular atrophy have produced promising results in clinical trials. The formation of chemical alterations that boost affinity and selectivity while reducing noxiousness owing to off-target impacts are two benefits of ASOs. Another benefit is increased affinity. With a focus on RnAi and ASOs, this review illustrated the main therapeutic strategies of RnA therapy now in use.

关键词： Antisense Oligonucleotides Ribozymes Phosphorothioate Double-Stranded RnA-Mediated Interference nucleases

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The Effect of a Monatomic Layer on a Surface on the Transition Radiation

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Journal of High Energy Physics, Gravitation and Cosmology 2024年第2期10卷 710-723页

作者： Alexander n. Safronov Obukhov Institute of Atmospheric Physics Russian Academy of Sciences Moscow Russia

The transition radiation of a charged particle crossing the interface of two media having a monatomic impurity layer is investigated. It is shown that at sliding angles of incidence of a particle on the boundary of the media, the transition radiation is mainly determined by the properties of the surface layer. The possibility of using transition radiation to study the surface of substances is discussed. In addition, due to the hard radiation present in space, this research may be important for the use of light monoatomic layers as a material for satellite antennas, “solar sails” and cover layers in a future space (interstellar) mission.

关键词： Relativistic Charged Particle Transition Radiation Monatomic Layer Spectral Angular Distribution of Radiation Sliding Angle Investigation of Thin Films Interstellar Mission

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Dichloro-Diphenyl-Trichloroethane (DDT) and Endosulfan in Sediments of Sabancuy Lagoon, Campeche, Mexico

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Open Journal of Ecology 2016年第1期6卷 22-31页

作者： Miguel Angel Ramírez-Elías Atl Victor Córdova-Quiroz Julia Griselda Cerón-Bretón Rosa María Cerón-Bretón Jaime Rendón-von Osten Javier Hipólito Cortés-Simón Facultad de Química Universidad Autónoma del Carmen Ciudad del Carmen México Centro de Ecología Pesquerías y Oceanografía del Golfo de México (EPOMEX) Universidad Autónoma de Campeche Campeche México Secretaria de Marina V Zona Naval Estación de Investigación Oceanográfica Cd del Carmen Campeche México

DDT and Endosulfan are persistent organic compounds which have been prohibited and their use has been limited in agricultural activities due to their toxicity, persistence and bioaccumulation potential. The use of DDT in fumigation campaigns against endemic diseases transmitted by vectors of malaria and dengue was prohibited in Carmen Island, Campeche, Mexico since 1995. In the surroundings of Sabancuy Lagoon, many and diverse agricultural activities are carried out and it is a common practice to use organ-chlorine pesticides as endosulfan. In order to know the levels of these compounds in this area, a sediment sampling campaign was carried out in ten sampling points randomly located within the Sabancuy Lagoon, Campeche and considering one reference sampling point located 2 km away from Sabancuy Lagoon within the Mexican Gulf. Three metabolites were identified in sediments samples belonging to DDT’s family: (4,4’-DDD;4,4’-DDE;4,4’- DDT) and Endosulfan’s family (Endosulfan I, Endosulfan II y Endosulfan sulfate). Higher concentrations in DDT’s family were found for 4,4’-DDD, followed by 4,4’-DDE and 4,4’-DDT. Endosulfan’s family, showed the following order for concentrations: Endosulfan II > Endosulfan I > Endosulfan sulfate. Mean concentration for S-DDT and S-Endosulfan in Sabancuy Lagoon sediments was twice higher than those found in other studies carried out in Términos Lagoon, Campeche, Mexico in 2002.

关键词： Organochlorine Pesticides Pollution Sabancuy Coastal Lagoons

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