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101.
Wireless Networks - In most websites, the online rating system provides the ratings of products and services to users. Lack of trust in data integrity and its manipulation has hindered fulfilling... 相似文献
102.
A desulfurization process for model oil and real oil was investigated based on the chemical oxidation of mixed sulfur containing compounds in the presence of nitrogen compounds (indole and quinoline) using hydrogen peroxide as oxidizing agent and dodecamolibdophosphoric acid (H3PMo12O40) encapsulated in a kind of metal-organic framework (HKUST-1) as PMo@HKUST-1. The effect of isopropanol, ethanol and acetonitrile as extractive solvent and 1-ring (toluene, xylene and mesitylene) and 2-ring (naphthalene) aromatic hydrocarbons in desulfurization of model oil was studied. The desulfurization of sulfur-containing compounds was accelerated in the presence of aromatic hydrocarbons. In fact, a higher desulfurization efficiency of the heterogeneous catalyst could be achieved with system containing a polar solvent in contact with an aromatic hydrocarbon. Quinoline had no effect on oxidative desulfurization (ODS) reaction, whereas indole had a slightly negative effect. Presence of aromatic compounds had slightly positive effect on ODS reaction. 相似文献
103.
Application of Taguchi approach in describing the mechanical properties and thermal decomposition behavior of poly(vinyl chloride)/clay nanocomposites: Highlighting the Role of organic modifier
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Elnaz Esmizadeh Mehdi Moghri Mohammad Reza Saeb Mohsen Mohsen Nia Narges Nobakht Nakul Prabhakar Bende 《乙烯基与添加剂工艺杂志》2016,22(3):182-190
Mechanical and thermal properties of poly(vinyl chloride) (PVC)/nanoclay (NC) composites prepared via melt‐blending in a single‐screw extruder were investigated. The effects of NC type, NC content, and K‐value of PVC were evaluated by using L9 orthogonal array of the Taguchi approach. The most influential variables and significance of interactive effects were examined for the highest values of Young's modulus and hardness. Scanning electron micrographs and X‐ray diffraction patterns revealed the formation of exfoliated/intercalated structures. Although the K‐value has a minor individual effect on mechanical characteristics, the interaction of the K‐value with NC type and NC content is significant. The composites were also characterized and tested by using analysis by thermal gravimetry, differential thermogravimetry, and differential scanning calorimetry methods. The results of the thermal studies indicated that decomposition of the organic modifier of NCs has a catalytic effect on the dehydrochlorination of PVC. This finding justifies the rather low mechanical properties of PVC/organoclay nanocomposites. Fourier‐transform infrared spectra of the samples were indicative of accelerated degradation reactions, which provided support for above observations. J. VINYL ADDIT. TECHNOL., 22:182–190, 2016. © 2014 Society of Plastics Engineers 相似文献
104.
FinFET technology is one of the most promising candidates in replacing planar MOSFET beyond the 22 nm technology node. However, the complexity of FinFET manufacturing process has caused challenges in reliable device testing. Gate oxide short (GOS) is one of the dominant defects that has significant impact on circuit reliability. In this paper, we present a GOS defect model for FinFETs by introducing the defect as a pinhole in the gate oxide of a triangular fin shape structure. The pinholes are represented by small cuboid cuts of various sizes on the fin top and sidewalls along the channel. The 3D Sentaurus TCAD simulation results in the development of an analytical GOS defect model that can be used in circuit-level fault modeling, which leads to generating more realistic test patterns. 相似文献
105.
While niobium can significantly improve the yield strength of microalloyed steels, such additions frequently result in low toughness and heat-affected-zone embrittlement. A direct correlation between fracture surface appearance, fracture profile, microstructure and precipitation behavior may be used to explain differences in toughness as a function of niobium content in steels containing 0.03, 0.06 and 0.21 wt.% niobium. 相似文献
106.
In recent decades, researchers have always considered the production of modified bitumen that could perform suitably in both high and low temperatures. One bitumen modifier is styrene butadiene styrene (SBS) polymer. Because bitumen modified with styrene butadiene styrene polymer does not show expected field performance in high and low temperatures largely due to phase separation of bitumen and polymer, the present research study is an attempt to use the composite of nano-SiO2 and styrene butadiene styrene polymer in modification of bitumen and analyze its high-temperature performance. The study revealed that adding nano-SiO2 to bitumen modified with SBS polymer resulted to an improvement of complex modulus, phase angle, resistance potential against rutting, storage modulus, loss modulus, and high-temperature functional performance in general. Additionally, the study uncovered that adding nano-SiO2 with 3% and 4% of bitumen weight, compared with other composites, considerably improved the high-temperature functional performance of bitumen modified with styrene butadiene styrene polymer. As 4.5%SBS+4%nano-SiO2 could not estimate less than 3 Pa.sec rotational viscosity in 135°C, 4.5%SBS+3%nano-SiO2 is offered as the optimal composite. The study is the first one in its own type in the world and is, therefore, innovative. 相似文献
107.
Yadollahi Milad Shams Taleghani Arash Esfahanian Vahid 《The Journal of supercomputing》2022,78(7):9065-9078
The Journal of Supercomputing - An object-oriented PIC-DSMC numerical code using the C++ programing language was developed to predict the grid erosion and lifetime of the multi-grid and, in... 相似文献
108.
A.S. Abouhaswa Hesham M.H. Zakaly Shams A.M. Issa M. Rashad Maria Pyshkina H.O. Tekin R. El-Mallawany Mostafa Y.A. Mostafa 《Ceramics International》2021,47(1):185-204
A series of bismo-borate (50-x)B2O3-xTiO2-15Na2O–30Bi2O3 glass samples (where x = 0, 2.5, 5, 7.5, and 10 wt%) doped with TiO2 were fabricated via the melt-quenching technique. The gamma and neutron shielding, physical, optical, and mechanical properties of the prepared samples were investigated. The experimental results were measured using an HPGe detector. 152Eu, 133Ba, 137Cs, and 60Co radioactive sources were used with energies in the range of 81–1408 keV. The experimental results were compared with both the FLUKA code and the XCOM database. The addition of TiO2 increased the density of the glass samples and decreased their molar volume. The mass attenuation coefficient (MAC) decreased as photon energy decreased, while it increased as TiO2 concentration increased. The half value layer (HVL) and mean free path (MFP) of the glass samples increased when the photon energy increased and decreased as the TiO2 concentration increased. The absorbance of the present samples is enhanced by using TiO2, meaning they can be used to protect humans from UV light. Both direct and indirect band gaps decreased as TiO2 content increased from 0 to 10 wt %. Moreover, the electronic transition between localized states is valid in the present samples. The radiation shielding, optical, physical, and mechanical properties of the fabricated glass samples demonstrate their utility for diagnostic gamma shielding. 相似文献
109.
Mona Nobakht Maryam S. Sakhaeifar David Newcomb Shane Underwood 《International Journal of Pavement Engineering》2018,19(8):675-684
A well-planned rehabilitation approach helps agencies to optimise the allocation of annual investment in pavement rehabilitation programs. Currently, many agencies are struggling with the selection of an optimal time-based and cost-effective rehabilitation solution to address the long-term needs of pavements. This study offers the use of a mechanistic-empirical methodology to develop a series of time-based rehabilitation strategies for high traffic volume flexible pavements located in Oklahoma. Six different pavement family groups are identified in the state, and comprehensive evaluation of existing pavements are conducted through analysis of falling weight deflectometer data and performance measures available in Oklahoma Pavement Management System database. The inadequacy of performance measures to fully characterise the condition of existing pavements are indicated, and damage factor determined from FWD data are suggested as trigger factor to select rehabilitation candidates. Three levels of rehabilitation activities including light, medium and heavy are considered as potential alternatives for rehabilitation candidates. A mechanistic-empirical methodology is employed to obtain an estimate of the performance of rehabilitation and extension in service lives of pavements. Also, an assessment output matrix is developed, which can be served as a supplemental tool to help the decision-makers in the highway agency with the rehabilitation related decision-making process. Cost-effectiveness of rehabilitation alternatives is determined through life cycle cost analysis, and three time-based renewal solutions are developed for pavement family groups that are in need of rehabilitation. 相似文献
110.
In this paper, a multi-product multi-machine serial production line operated under a constant-work-in-process protocol is considered. A mathematical model for the system is first presented, and then an artificial bee colony optimization algorithm is applied to simultaneously find the optimal work-in-process inventory level as well as job sequence order in order to minimize the overall makespan time. Unlike many existing approaches, which are based on deterministic search algorithms such as nonlinear programming and mixed integer programming, the proposed method does not use a linearized or simplified model of the system. A production line simulator implemented on MATLAB is, instead, employed to model the highly nonlinear dynamics of the production line and is used to evaluate the candidate solutions. The efficiency of the proposed approach, even for systems of large sizes, is validated via numerical simulations. 相似文献