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641.
Power reclamation efficiency of a miniature energy‐harvesting device using external fluid flows 下载免费PDF全文
This study represents experimental results related to the energy‐harvesting capability of a miniature power reclamation device based on external liquid flows. The device's reclamation principle depends on the conversion of mechanical energy into electrical energy. The mechanical energy in the device was generated by capturing vibrations caused by external liquid flows via the device's tails, which were designed by taking inspiration from the body shape of the black ghost knife fish, Apteronotus albifrons. The reclaimed power was obtained through magnetic polarization, which was generated by rotating circular waterproof magnet structures as a result of rotating movements of the mentioned tails and is transferred to 3.76 V (Ni‐Mg) batteries. Power reclamation was also simulated using COMSOL 4.2a software in order to compare the maximum reclaimable theoretical energy‐harvesting capacity with the experimental results. Experimental tests were performed within a range of flow velocities (1.0 ~ 5.0 m/s) for various fluid densities (plain water, low‐salt water and high‐salt water) in order to obtain extensive experimental data related to the device in response to external fluid flows. According to experimental results, the device could generate powers up to 17.2 W. On the other hand, the maximum reclaimable power was obtained at 25.7 W from COMSOL Multiphysics 4.2a simulations. Promising energy harvesting results imply that the output from this device could be used as a power source in many applications such as in lighting and global positioning system (GPS) devices. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
642.
The purpose of this paper is to examine Islamic perspectives on conflict management within project managed environments. Existing research does not reveal any study that examines empirically the Islamic viewpoint on conflict management in contemporary organisational contexts but does indicate that conflict in Islam is considered to be inevitable and a part of human nature, and, if managed properly, is positive and constructive. This paper aims to address this gap, by presenting an empirical analysis of Islamic models of conflict management. It is argued that the three Islamic models discussed, are partially and covertly in existence in environments not traditional to their own. Consequently, the paper finds that there is scope for investigating explicit applied aspects to these Islamic models. The paper concludes that existence of Islamic models for conflict management is visible and has potential for application by project managers without limitation. 相似文献
643.
Chemical treatment of sludge: in-depth study on toxic metal removal efficiency, dewatering ability and fertilizing property preservation 总被引:1,自引:0,他引:1
The presence of toxic metals in municipal sewage sludge restricts the application of this biomass in agricultural area. A chemical leaching process using a combination of inorganic acid and two oxidants has been developed for sludge decontamination. The present study investigated the effects of the concentrations of sulphuric acid (H2SO4), hydrogen peroxide and ferric chloride on metal solubilization from sewage sludge, as well as preservation of fertilizing properties (nutrient content) and dewatering ability of the treated sludge. The analysis of the results from batch leaching tests has allowed to define the optimal conditions for the reagent concentrations, which are 56 kg Fe3+ tonne(-1) of dry sludge solids (tds), 8 kg H2O2 tds(-1), and enough H2SO4 to reach a pH between 2.0 and 2.5 but less than 142 kg H2SO4 tds(-1). Finally, under these conditions, oxidoreduction potential values are found to be between 450 and 475 mV. 相似文献
644.
A complete analysis of the off-south oriented, simple flat plate collector, augmented by flat sheet specular reflector, is developed. The enhancement of heat flux absorbed by solar collector due to the use of reflector is calculated as a funciton of solar altitude and azimuth angles, off-south orientation angle of collector and relative sizes and tilt angles of both collector. The shading effect due to the presence of the reflector is considered in the analysis. The collector and reflector variables are optimized for maximum solar energy flux absorbed by the collector during a pre-specified period of time. The Hooke and Jeeves optimization technique has been used in the analysis. 相似文献
645.
S. Sadi W.D. Loveland 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(24):3230-3232
Radiation damage caused by fission fragments to metal surfaces is an important research topic. Thin titanium foils were irradiated with a continuous wave beam of 132 MeV 132Xe+29 at the current intensity of 2 pnA. Pre- and post-irradiated surface topologies were investigated using atomic force microscopy and the observed defects were quantified by root mean square roughness, depth profile of the disordered zones, size and areal density of the voids, and discussed as a function of the applied fluencies (1-9) × 1013 Xe/cm2. The first ellipsoidal dislocation loops appeared at the fluence of 3.0 × 1013 Xe/cm2 with the areal density of 1.56 × 106/cm2 that increased to 2.0 × 107 cm−2 when the dose rose to 9.0 × 1013 Xe/cm2. At this point also the first dislocation lines with the density of 1.3 × 107 cm−2 were seen. Our results suggest that the fission fragments might maximize large voids and dislocations and increase the degradation in depth resolution. 相似文献
646.
In this study, we investigated the draping behavior of jute woven fabric to study the feasibility of using natural fabrics in place of synthetic glass‐fiber fabrics. Draping behavior describes the in‐mold deformation of fabrics, which is vital for the end appearance and performance of polymer composites. The draping coefficient was determined with a common drapemeter for fabrics with densities of 228–765 g/m2 and thread counts under different humidity and static dynamic conditions. The results were compared to glass‐fiber fabrics with close areal densities. Characterization of the jute fabrics was carried out to fill the knowledge gap about natural‐fiber fabrics and to ease their modeling. The tensile and bending stiffnesses and the shear coupling were also characterized for a plain woven jute fabric with a tensile machine, Shirley bending tester, and picture frame, respectively. As a case study, the draping and resin‐transfer molding of the jute fabric over a complex asymmetric form was performed to measure the geometrical conformance. The adoption of natural fibers as a substitute for synthetic fibers, where the strength requirements are satisfied, would thus require no special considerations for tool design or common practices. However, the use of natural fibers would lead to weight and cost reductions. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1453–1465, 2013 相似文献
647.
FTIR evaluation of functional groups involved in the formation of haloacetic acids during the chlorination of raw water 总被引:6,自引:0,他引:6
Kanokkantapong V Marhaba TF Panyapinyophol B Pavasant P 《Journal of hazardous materials》2006,136(2):188-196
This work investigated the formation potential of haloacetic acid (HAA) compounds in the raw water for the Bangkhen water treatment plant (Bangkok, Thailand). The resin adsorption technique (with three different types of resins, i.e. DAX-8, AG-MP-50 and WA-10) was employed to characterize the organic content in the raw water into six fractions, i.e. hydrophobic neutral (HPON), hydrophobic acid (HPOA), hydrophobic base (HPOB), hydrophilic neutral (HPIN), hydrophilic acid (HPIA) and hydrophilic base (HPIB). Hydrophilic species appeared to be the predominant organic species in this water source (approximately 60%) with the neutral fraction being the most abundant (approximately 40%). Hydrophobic species, on the other hand, played the most important role in the formation of haloacetic acids as they contributed to as much as approximately 56% of total HAA formation potential. Among the three hydrophobic species, the hydrophobic base exhibited the highest specific HAA formation with 208mugHAAs/mg of dissolved organic carbon (DOC). Each organic fraction was examined for its associated functional groups by Fourier transform infrared (FTIR). The investigation of the formation of HAAs was achieved by tracking the changes in the FTIR results of the same water sample before and after the chlorination reaction. Based on the results obtained from this study, carboxylic acids, ketone, amide, amino acids and aromatic characteristic organics seemed to be the main precursors to HAA formation. 相似文献
648.
Sadi AY Shokrgozar MA Homaeigohar SSh Hosseinalipour M Khavandi A Javadpour J 《Journal of materials science. Materials in medicine》2006,17(5):407-412
The effect of partially stabilized zirconia (PSZ) on the biological properties of the hyroxyapatite - high density polyethylene
(HA/HDPE) composites was studied by investigating the simultaneous effect of hydroxyapatite and PSZ volume fractions on the
in vitro response of human osteoblast cells. The biocompatibility of composite samples with different volume fraction of HA and PSZ
powders was assessed by proliferation, alkaline phosphatase (ALP) and cell attachment assays on the osteoblast cell line (G-292)
in different time periods. The effect of composites on the behavior of G-292 cells was compared with those of HDPE and TPS
(Tissue Culture Poly Styrene as negative control) samples. Results showed a higher proliferation rate of G-292 cells in the
presence of composite samples as compared to the HDPE sample after 7 and 14 days of incubation period. ALP production rate
in all composite samples was higher than HDPE and TPS samples. The number of adhered cells on the composite samples was higher
than the number adhered on the HDPE and TPS samples after the above mentioned incubation periods. These findings indicates
that the addition of PSZ does not have any adverse affect on the biocompatibility of HA/HDPE composites. In fact in some experiments
PSZ added HA/HDPE composites performed better in proliferation, differentiation and attachment of osteoblastic cells. 相似文献
649.
Zahari Taha Khusnun Widiyati 《The International Journal of Advanced Manufacturing Technology》2010,50(1-4):289-296
Neural networks have been widely used for many applications. One of the applications is forecasting. Many studies have proven that neural networks can provide good accuracy on forecasting future data with over than 80% accuracy. In this study, neural network is used to predict bearing defects. Two learning tasks, function approximation and pattern recognition, were used for detection and monitoring of defects in ball bearing. Given five categories of bearing defect, the neural networks have successfully proven the ability to distinguish one defect over the other with high accuracy. Acoustic emission (AE) was used as a measurement in this study. AE is defined as transient waves generated from a rapid release of strain energy by deformation or damage or on the surface of a material (1–3). The AE waves can provide information about bearing condition. Maximum amplitude and AE counts were used as the basis for detection. 相似文献
650.
Sobhan Mosayebidorcheh Taha Mosayebidorcheh 《International Journal of Heat and Mass Transfer》2012,55(23-24):6589-6594
In this study, differential transform method (DTM) is used to evaluate the analytical solution of the nonlinear fin problem with temperature dependent thermal conductivity. Results are presented for the dimensionless temperature distribution and fin efficiency for a range of values of the problem parameters. Using DTM, the differential equation and related boundary conditions are transformed into a recurrence set of equations and finally, the coefficients of power series are obtained based on the solution of this set of equations. Results of this method are compared with the variational iteration method (VIM) and numerical solutions. Here, it is shown that the results of DTM are more accurate than the VIM with lesser calculation cost, which is the main innovation of the current study. 相似文献