Military Academy

About: Military Academy is a based out in . It is known for research contribution in the topics: Population & Context (language use). The organization has 2478 authors who have published 3003 publications receiving 33188 citations.

Strength changes of moulded polyamide composite caused by thermal oxidation

Abstract: Rolling-bearing cages (separators) which were made by injection moulding from polyamide 66 filled with short glass fibres were tested before and after exposures in hot air at temperatures 120, 140, 160, and 180°C at various times ranging from a few hours to three weeks. The cages were loaded in tension and the changes of maximum force corresponding to ultimate tensile stress were studied. A very simple degradation mechanism containing the main features of the real degradation processes was proposed and its kinetic equations were derived. On the basis of the assumption that the changes of properties during ageing are proportional to the changes of chemical composition and structure a regression function was proposed. It was used for the fitting of the measured results and for the construction of predictive curves which describe the temporal and temperature dependence of strength for working temperatures and long times.

Silver-Protein Nanocomposites as Antimicrobial Agents.

Abstract: The use of nanomaterials alone or in composites with proteins is a promising alternative to inhibit pathogenic bacteria. In this regard, this study used seed proteins from both fenugreek (Trigonella foenum-graecum L.) (FNP) and mung bean (Viga radiate) (MNP), with silver nanoparticles (Ag-NPs) and nanocomposites of either Ag-NPs plus FNP (Ag-FNP) or Ag-NPs plus MNP (Ag-MNP) as inhibitory agents against pathogenic bacteria. FNP and MNP were isolated from fenugreek seeds and mung bean seeds, respectively, and fractionated using Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis (SDS–PAGE). Both FNP and MNP were immobilized with Ag-NPs to synthesize the nanocomposites Ag-FNP and Ag-MNP, respectively. The physicochemical characteristics of Ag-NPs and their composites with proteins were studied by X-ray Diffraction (XRD), dynamic light scattering (DLS), the zeta potential, Scanning and Transmission Electron Microscopy (SEM and TEM, respectively), Atomic Force Microscopy (AFM), and the Brunauer–Emmett–Teller isotherm (BET), elucidating their structural parameters, size distribution, size charges, size surface morphology, particle shape, dimensional forms of particles, and specific surface area, respectively. The sole proteins, Ag-NPs, and their nanocomposites inhibited pathogenic Gram-positive and Gram-negative bacteria. The inhibitory activities of both nanocomposites (Ag-FNP and Ag-MNP) were more than those obtained by either Ag-NPs or proteins (FNP, MNP). Minimum inhibitory concentrations (MICs) of Ag-FNP were very low (20 and 10 µg mL−1) against Salmonellatyphimurium and Pseudomonasaerugenosa, respectively, but higher (162 µg mL−1) against E. coli and Listeriamonocytogenes. MICs of Ag-MNP were also very low (20 µg mL−1) against Staphylococcusaureus but higher (325 µg mL−1) against Listeriamonocytogenes. TEM images of Staphylococcusaureus and Salmonellatyphimurium, treated with Ag-FNP and Ag-MNP, at their MIC values, showed asymmetric, wrinkled exterior surfaces, cell deformations, cell depressions, and diminished cell numbers.

Counting Balanced Boolean Functions in n Variables with Bounded Degree

Abstract: We consider the problem of obtaining good upper and lower bounds on the number of balanced Boolean functions in n variables with degree less than or equal to k. This is the same as the problem of finding bounds on the number of codewords of weight 2n-1 in the Reed–Muller code of length 2n and order k. We state several conjectures and use them to obtain good bounds. We believe that the conjectures will be highly useful for further research.

Batch and column adsorption of cations, oxyanions and dyes on a magnetite modified cellulose-based membrane

Abstract: An optimized method is presented to make magnetite (MG) modified cellulose membrane (Cell-MG) from 3-aminopropyltriethoxysilane and diethylenetriaminepentaacetic acid dianhydride functionalized waste cell fibers; (Cell-NH2 and Cell-DTPA), and amino-modified diatomite. Functionalized Cell-NH2, Cell-DTPA fibers, and diatomite were structurally and morphologically characterized using FT-IR, Raman, and FE-SEM analysis. Amino and carboxyl group content was determined via standard volumetric methods. Response surface method was applied to rationalize the number of experiments related to Cell-MG synthesis and heavy metal ions column adsorption experiments. The effects of pH, contact time, temperature, and initial concentration of pollutants on adsorption and kinetics were studied in a batch, while initial concentration and flow rate were studied in a flow system. The calculated capacities of 88.2, 100.7, 95.8 and 78.2 mg g−1 for Ni2+, Pb2+, Cr(VI) and As(V) ions, respectively, were obtained from Langmuir model fitting. Intra-particle diffusion as a rate-limiting step was evaluated from pseudo-second-order and Weber–Morris model fitting. Thermodynamic parameters indicated spontaneous and low endothermic processes. The results from reusability study, wastewater purification and fixed-bed column study proved the high applicability of Cell-MG. Additionally, high removal capacity of four dyes together with density functional theory and molecular interaction fields, help in the establishment of relation between the adsorption performances and contribution of non-specific and specific interactions at adsorbate/adsorbent interface.