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排序方式: 共有385条查询结果,搜索用时 46 毫秒
1.
Sarband Ebrahim Mokallaf Araghinejad Shahab Attari Jalal 《Water Resources Management》2020,34(2):447-462
Water Resources Management - In water resource management, assessing water resource allocation scenarios (WRASs) is an important multi-attribute decision making (MADM) problem. It involves... 相似文献
2.
Majid Alizadeh Moghadam Reza Mohammadi Ehsan Sadeghi Mohammad Amin Mohammadifar Mohammad Nejatian Maryam Fallah Milad Rouhi 《应用聚合物科学杂志》2021,138(28):50672
The effects of gum tragacanth obtained from two species of Astragalus Gossypinus (GT-G) and A. Parrowianus (GT-P) at two levels of 10% and 30% combined with cellulose nanofibers (CNF; 5%) on the physico-mechanical and structural properties of polyvinyl alcohol (PVA) nanocomposite film were investigated in this study. The water solubility and water vapor permeability of the films decreased with increasing the content of both gums, especially in the film containing 30% GT-P. The highest values of the tensile strength (39.3 MPa) and elongation at break (445%) belonged to the treatment containing 10% GT-P (90/10P/0). The FTIR and DSC analyses confirmed good interactions between GT and PVA in the 90/10P/0 treatment. SEM images indicated the dense structure of this film as the optimum treatment. Although the presence of CNF in the films containing GT-G improved some properties, especially the Young modulus, it impaired all the functional properties of nanocomposite GT-P film. 相似文献
3.
Leila Rezaei Somee Parinaz Ghadam Ahya AbdiAli Soudabeh Fallah Ghodratollah Panahi 《IET nanobiotechnology / IET》2018,12(6):764
Silver nanoparticles (AgNPs) have attracted the attention of researchers due to their properties. Biological synthesis of AgNPs is eco‐friendly and cost‐effective preferred to physical and chemical methods, which utilize environmentally harmful agents and large amounts of energy. Microorganisms have been explored as potential biofactories to synthesize AgNPs. Bacterial NP synthesis is affected by Ag salt concentration, pH, temperature and bacterial species. In this study, Bacillus spp., isolated from soil, were screened for AgNP synthesis at pH 12 with 5 mM Ag nitrate (AgNO3) final concentration at room temperature. The isolate with fastest color change and the best ultraviolet‐visible spectrum in width and height were chosen as premier one. AgNO3 and citrate salts were compared in terms of their influence on NP synthesis. Spherical Ag chloride (AgCl) NPs with a size range of 35–40 nm were synthesized in 1.5 mM Ag citrate solution. Fourier transform infrared analysis demonstrated that protein and carbohydrates were capping agents for NPs. In this study, antimicrobial and antitumor properties of the AgNP were investigated. The resulting AgCl NPs had bacteriostatic activity against four standard spp. And multi‐drug resistant strain of Pseudomonas aeruginosa. These NPs are also cytotoxic to cancer cell lines MCF‐7, U87MG and T293.Inspec keywords: silver compounds, nanoparticles, nanomedicine, nanofabrication, particle size, biomedical materials, microorganisms, ultraviolet spectra, visible spectra, Fourier transform infrared spectra, proteins, macromolecules, antibacterial activity, tumours, cancer, cellular biophysics, toxicologyOther keywords: citrate salts, spherical Ag chloride, particle size, Ag citrate solution, Fourier transform infrared analysis, protein, carbohydrates, capping agents, antitumour properties, bacteriostatic activity, Pseudomonas aeruginosa, multidrug resistant strain, cancer cell lines MCF‐7,U87MG, size 35 nm to 40 nm, temperature 293 K to 298 K, AgCl, ultraviolet‐visible spectrum, colour change, room temperature, Ag nitrate final concentration, soil, bacterial species, temperature effect, pH, Ag salt concentration, biofactories, microorganisms, environmentally harmful agents, chemical methods, physical methods, antibacterial properties, electrical properties, mechanical properties, silver nanoparticles, multidrug resistant bacteria, antibiofilm effects, antibacterial effects, cytotoxic activity, Bacillus sp. 1/11, biosynthesised AgCl NPs 相似文献
4.
Tsung-Liang Wu Chaw-Wu Tseng Chen-Chi Lin Shahab Hatam-Tabrizi I. Y. Shen 《Microsystem Technologies》2010,16(1-2):9-17
This paper is to study how stray magnetic forces encountered in a long seeking process affect position errors of a hard disk drive after it finishes the seek and settles. The study consists of three parts: analysis of stray magnetic forces, numerical modeling, and analysis of numerical results. In the analysis of stray magnetic forces, we lump the stray magnetic forces into three components D1, D2 and D4. Specifically, D1 is a pair of stray magnetic forces in the plane of the voice coil. The two forces act on the two equal legs of the voice coil. In addition, the two forces point to and away from the pivot center, respectively. D2 is a pair of stray magnetic forces out of the plane of the voice coil. The two forces are equal in magnitudes but opposite in directions. The two force components also act on the two equal legs of the voice coil. D4 is identical to D2, except that the two force components in D4 act in the same direction. In the numerical study, we adopt a numerical model that includes a spinning spindle motor, a spinning disk pack with multiple disks, a stationary base plate with a top cover, and a slewing head-stack assembly. Moreover, multiple bearings are present in the model to connect the multiple components. In particular, fluid-dynamic bearings connect the rotating spindle and disk pack with the base plate, pivot bearings connect the base plate with the head-stack assembly, and air bearings connect the spinning disk pack with head sliders located at the tip of the slewing head-stack assembly. Also, the numerical model assumes that the head-stack assembly seeks according to a user-specified seeking profile. Numerical simulations show two major conclusions. First, stray magnetic force component D1 does not lead to significant position errors when the head-stack assembly settles. Stray magnetic force components D2 and D4, however, can affect the position errors by significantly exciting torsion and bending modes of the head-stack assembly. Second, a flex cable can significantly increase position errors below 1 kHz during settling. 相似文献
5.
Alireza Shamsi Amir Shamloo Negar Mohammadaliha Hassan Hajghassem Jalil Fallah Mehrabadi Masoumeh Bazzaz 《Microsystem Technologies》2016,22(10):2447-2454
Since plasma is rich in many biomarkers used in clinical diagnostic experiments, microscale blood plasma separation is a primitive step in most of microfluidic analytical chips. In this paper, a passive microfluidic device for on-chip blood plasma separation based on Zweifach–Fung effect and plasma skimming was designed and fabricated by hot embossing of microchannels on a PMMA substrate and thermal bonding process. Human blood was diluted in various times and injected into the device. The main novelty of the proposed microfluidic device is the design of diffuser-shaped daughter channels. Our results demonstrated that this design exerted a considerable positive influence on the separation efficiency of the passive separator device, and the separation efficiency of 66.6 % was achieved. The optimum purity efficiency of 70 % was achieved for 1:100 dilution times. 相似文献
6.
7.
Reza Ramezanian Sahar Fallah Sanami Mohsen Shafiei Nikabadi 《The International Journal of Advanced Manufacturing Technology》2017,88(9-12):2389-2403
The aim of this paper is to study a simultaneous lot-sizing and scheduling in multi-product, multi-period flexible flow shop environments. A new mixed integer programming (MIP) model is proposed to formulate the problem. The objective function includes the total cost of production, inventory, and external supply. In this study, in case of not meeting the demand of customers, this demand should be met by foreign suppliers in higher price. Due to the high computational complexity of the studied problem, a rolling horizon heuristic (RHH) and particle swarm optimization algorithm (PSO) are implemented to solve the problem. These algorithms find a feasible and near-optimal from production planning and scheduling. Additionally, Taguchi method is conducted to calibrate the parameters of the PSO algorithm and select the optimal levels of the influential factors. The computational results show that the algorithms are capable of achieving results with good quality in a reasonable time and PSO has better objective values in comparison with RHH. Also, the real case study for tile industry with real features is applied. Sensitivity analysis is used to evaluate the performance of the model. 相似文献
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9.
Theoretical calculation simulation studies of ABV nuclear reactor coupled with desalination system
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Salah Ud‐Din Khan Syed Noman Danish Sajjad Haider Shahab Ud‐Din Khan 《国际能源研究杂志》2015,39(11):1554-1563
In this paper, research has been conducted on the floating type nuclear power plant named as ABV reactor which is designed for district heating, power, and sea water desalination by OKBM facility at Russia. This reactor was tested under different thermal loads during the designing phase, and three modules have been investigated. Theoretical calculations and simulation studies have been performed on these three modules having specifications as ABV‐6M with 47MWth, ABV‐6 with 38MWth, and ABV‐3 with 18MWth.The results obtained from these modules have been calculated mathematically and verified by simulation. We have compared the originally derived data of ABV desalination system with our theoretical and simulation analysis. The results from two desalination techniques including RO and RO + MED have been calculated and are presented in this paper with details. The results obtained from both analysis show that the efficiency of ABV nuclear reactor desalination system increases with the decrease in corresponding water cost ratio. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
10.
In this paper, a novel system has been developed for plasma disruption conditions followed by downward vertical displacement. During the disruption, size and orientation of plasma decreases, which gives the halo current circulated around each contacting point in radial as well as in poloidal directions. Therefore, a new mathematical model has been developed, which gives the interaction forces of halo current, vertical, and radial plasma dynamical behavior (linear and nonlinear). This theoretical approach showed that the tokamak plasma has two connecting points in order to distinguish between the stable and unstable position. This model can particularly give the magnetic field change points and changing of flux, which are more convenient in order to discuss the static and tilting position of plasma behavior. Numerical techniques have been calculated in terms of plasma dynamical behavior, that is, Electromagnetic/plasma, Vertical Displacement Event (VDE) stages, and initial interaction between the forces under specific time interval. The objective of the research is to developed theoretical and computational model in order to investigate the dynamical behavior of plasma under disruption conditions. This is the novel method, and no work has been reported so far. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献