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71.
Khaled Safi Samer Mohammed Inke Marie Albertsen Eric Delechelle Yacine Amirat Mohamad Khalil Jean-Michel Gracies Emilie Hutin 《Signal, Image and Video Processing》2017,11(6):1081-1088
The present study proposes a new approach for the assessment of the human balance control. This approach is based on the decomposition of the center of pressure displacement using empirical mode decomposition (EMD) that provides an effective time-frequency analysis of non-stationary signals. Twenty-eight healthy subjects performed quiet standing in four conditions—feet apart/together with respect to eyes open/closed—while recording the stabilometric signals in the anteroposterior (AP) and mediolateral (ML) directions. The EMD method decomposes each stabilometric signal into several subsignals called intrinsic mode functions (IMFs). Stabilogram-diffusion analysis technique is applied to generate the diffusion curve of each IMF signal. Each diffusion curve is modeled as a second-order system and provides representative features, such as the gain parameter. Analysis of the gain parameter shows the major effect of visual input and feet conditions on the strategy to control/stabilize the balance. Significant differences were found between young and elderly, and between women and men. In addition, the impact of feet position seems to be higher in ML direction than in AP direction. 相似文献
72.
The Quantitative Strategic Planning Matrix (QSPM) is a useful tool to prioritize strategies at any level including corporate, business and functional. The ratings and attractive scores used in QSPM, however, require judgmental decisions and should be based on expert's opinion to ensure the applicability of chosen strategies. Application of a fuzzy multi-criteria decision making method is proposed in this paper with the goal of improving the output of conventional QSPM by allowing the experts to employ linguistic terms (qualitative data) in their judgments. Namely, a multi-criteria decision making index via the technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is adapted to the fuzzy QSPM in finding the sum total attractive scores of strategies. As a case study, the proposed method has been applied for strategy prioritization in a Tile Company. The results have been verified with expert knowledge and showed an improvement compared to the non-fuzzy QSPM. 相似文献
73.
Abolghasem Nourmohammadi Saeid Jalali Asadabadi Mohammad Hasan Yousefi Majid Ghasemzadeh 《Nanoscale research letters》2012,7(1):689
The photoluminescence emission of nanoporous anodic aluminum oxide films formed in phosphoric acid is studied in order to explore their defect-based subband electronic structure. Different excitation wavelengths are used to identify most of the details of the subband states. The films are produced under different anodizing conditions to optimize their emission in the visible range. Scanning electron microscopy investigations confirm pore formation in the produced layers. Gaussian analysis of the emission data indicates that subband states change with anodizing parameters, and various point defects can be formed both in the bulk and on the surface of these nanoporous layers during anodizing. 相似文献
74.
Hasan Yildirim Mansur Sümer Veysel Akyüncü Emrah Gürbüz 《Construction and Building Materials》2011,25(6):2939-2947
Fly ashes are obtained from thermal power plants and they are pozzolanic materials, which can act as partial replacement material for both portland cement and fine aggregate. With their economical advantages and potential for improving fresh and hardened concrete performance, they have some benefits for using in concrete industry. In this study, the objective was to find the efficiency factors of Turkish C and F-type fly ashes and to compare their properties. Three different cement dosages were used (260, 320, 400 kg/m3), two different ratios (10% and 17%) of cement reduced from the control concretes and three different ratios (depending on cement reduction ratio) of fly ash were added into the mixtures. At the ages of 28 and 90 days, compressive strength, modulus of elasticity and ultrasound velocity tests were carried out. From the compressive strength results, the k efficiency factors of C and F-type fly ashes were obtained. As a result, it is seen that efficiency factors of the concrete produced by the replacement of F and C type fly ashes with cement increase with the increase in cement dosage and concrete age. 相似文献
75.
In this study, L-cystein modified bentonite-cellulose (cellu/cys-bent) nanocomposite was synthesized and characterized by XRD, FTIR, SEM with EDS, TGA, and TEM techniques. In order to optimize the process the effect of various operational parameters such as pH, adsorbent dosage, contact time, and temperature were also investigated. The adsorption experiments were carried out in initial concentrations range of 20-100 mg L?1and the adsorbent affinity for metal ions was found to be in order of Cu2+ > Pb2+ > Cd2+. The optimum pH for adsorption of Cu2+ and Cd2+ was observed at 5 while for Pb2+ it was pH 6. Based on the Langmuir model, the maximum adsorption capacity of Cu2+, Pb2+, and Cd2+ at 50?C was found to be 32.36, 18.52, and 16.12 mg g?1, respectively. The Langmuir isotherm and pseudo-second order model were found to be better fitted than the other isotherms and kinetic models. The results of thermodynamic parameters confirmed the process to be endothermic and spontaneous in nature. 相似文献
76.
Melt spun matrix fibers of toughened polypropylene copolymers modified by high energy electrons 下载免费PDF全文
Binary blends of polypropylene (PP) and ethylene‐octene copolymer (EOC) are prepared by continuous electron‐induced reactive processing at various mass ratios of the blend components and various doses without adding of any grafting agents. The influence of mass ratio and dose is investigated in order to get the optimum processing behavior of toughened PP as well as optimum properties of resulting fibers. It is found that toughened PP with a PP/EOC blend ratio of 97.5–2.5 mass % can be used advantageously as a matrix component for the process of online spinning of glass fiber/toughened PP hybrid yarns. Such hybrid yarns belong to one of the most advanced production methods for the manufacturing of fiber reinforced thermoplastic composites with an increased mechanical performance. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44011. 相似文献
77.
Mohammad Tajul Islam Shahadat Hossain Khan Md Mahadi Hasan 《Coloration Technology》2016,132(3):255-264
An attempt was made to print cotton fabric with pigments using a new thickening agent based on Aloe vera gel in combination with sodium alginate. The results were compared with the standard conventional printing recipe containing synthetic thickener, and a favourable effect of Aloe vera introduction was achieved. The results show that the properties of the printed fabric (sharpness, colour yield, overall fastness properties, softness, and water vapour transmission) are dependent on the percentage of Aloe vera gel in the thickener combination, the concentration of printing auxiliaries, and the curing conditions. Optimal printing properties were achieved by using a printing paste containing 80% Aloe vera/20% sodium alginate (700 g kg?1), pigment (50 g kg?1), binder (145 g kg?1), fixer (10 g kg?1), and ammonium sulfate (5 g kg?1), followed by drying at 85 °C for 5 min and curing at 150 °C for 3 min. The sample printed with the new recipe showed superior rubbing fastness and handle properties, with a slightly lower colour yield, when compared with the sample printed with synthetic thickener. Finally, economic issues arising from synthetic thickener substitution are highlighted. 相似文献
78.
Shaikh A. Ali Shamsuddeen A. Haladu Mohammad A. J. Mazumder Hasan A. Al-Muallem 《Iranian Polymer Journal》2016,25(9):747-756
An aqueous solution of diallylammonium salts (CH2 = CHCH2)2NH+(CH2)3A? having A? as: CO2 ? (I), PO3H2 Cl? (II) and SO3 ? (III) in 1:1:1 mol ratio underwent ammonium persulfate-initiated ter cyclopolymerization to yield pH-responsive zwitterionic polymer IV with random placements of the monomers in the same ratio. During dialysis, PO3H2Cl? of the incorporated monomer units of II upon depletion of HCl became PO3H?. Likewise, azobisisobutyronitrile-initiated cyclopolymerization of I, II, III, and SO2 in a mole ratio of 1:1:1:3 provided pH-responsive tetrapolymer V in over 90 % yield with random and alternative placements of I–III and SO2 units, respectively, in the same ratio as the feed. Polyzwitterions (PZs) IV and V were insoluble in salt-free water but soluble in the presence of salts. The critical salt concentrations required to promote water solubility of PZ IV were determined to be 0.356 M NaCl, 0.237 M NaBr and 0.128 M NaI, whereas for PZ V the corresponding values were found to be 2.25, 1.26 and 0.862 M, respectively. PZs IV and V were converted into anionic polyelectrolytes VI and VII upon basification with NaOH. The viscosity and antiscalant behaviors of VI and VII were examined. The polymers demonstrated remarkable scale inhibition efficacies; at a dose of 10 ppm, both IV (+NaOH) and V (+NaOH) delayed the precipitation of CaSO4 from its supersaturated solution up to 920 and over 4000 min, respectively. For a small concentration of 5 ppm of polymer V, a scale inhibition of 100 % over 100 min verified it to be a potential effective antiscalant additive in reverse osmosis plants. 相似文献
79.
Nana Achile Alomayri Thamer Salman Venyite Paul Kaze Rodrigue C. Assaedi Hasan Suliman Nobouassia Christelle Bewa Sontia Jordan Valdès Metekong Ngouné Jean Kamseu Elie Leonelli Cristina 《SILICON》2022,14(1):263-274
Silicon - The synthesis, mechanical behaviour, and microstructure of metakaolin-based geopolymer mortar reinforced with quartz sand are presented in this investigation. Fine sand (quartz sand)... 相似文献
80.
Hasan Kouchakzadeh Seyed Abbas Shojaosadati Fazel Shokri 《Chemical Engineering Research and Design》2014
Herein, the poorly water-soluble drug, Tamoxifen (Tmx), was loaded in the amphipathic matrix of human serum albumin (HSA) nanoparticles by a modified desolvation method. In order to enhance the drug loading (DL) and drug entrapment efficiency (DEE) (<2% and 10%, respectively), ultrasonication of Tmx-HSA mixture was performed prior to desolvation process. Tmx loading and entrapment efficiency were optimized by employment of the response surface methodology (RSM)-central composite design (CCD) of experiments. Under the optimum conditions of 1.59 mg Tmx/ml concentration, 7.76 pH and 5 h incubation of HSA-Tmx, the DL of 6.7% and DEE of 74% are achievable. Particles with the average size of 195 nm, zeta potential of −21 mV and polydispersity index of 0.09 were produced under these conditions. A more sustained Tmx release behavior was observed from polyethylene glycol (PEG) conjugated nanoparticles in comparison to the non-PEGylated ones. The short-term stability investigation showed no alteration in physicochemical properties of nanoparticles at 4 and 37 °C, but small increase in nanoparticles size was observed after three months of storage at room temperature. This is the first report for efficient production of a Tmx delivery system based on HSA nanoparticles. 相似文献