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排序方式: 共有906条查询结果,搜索用时 31 毫秒
831.
Manish Aggarwal 《国际智能系统杂志》2018,33(4):879-898
The compensation capabilities of Choquet integral are augmented to consider the complex attitudinal character of a decision maker. The resulting operator is termed as attitudinal Choquet integral (ACI). The proposed ACI is further extended as induced ACI. The special cases of ACI are investigated. The usefulness of ACI is shown through a case study. 相似文献
832.
Epoxy resins are a very versatile class of compounds. They have excellent mechanical properties and are easily processable; however, their major drawback is their brittleness. An attempt was made to improve the impact strength of the epoxy without decreasing its other properties. In the present study a commonly used epoxy resin, diglycidyl ether of Bisphenol‐A, was modified by the addition of bismaleimide (BMI) and diallyl phthalate (DAP) and was cured with diaminodiphenylmethane and benzoyl peroxide. The composition incorporating 5 phr BMI showed maximum heat deflection temperature (HDT) and flexural strength with impact properties remaining almost unaffected. Further addition of BMI reduced the HDT and flexural properties but increased the impact strength. For epoxy‐DAP systems the maximum HDT and flexural strength were observed on addition of 5 phr DAP. Further addition of DAP lead to a decrease in all properties except impact strength, which was observed to increase. Incorporation of both BMI and DAP, simultaneously, into the epoxy resin resulted in improvement in mechanical properties for most of the compositions. However, the HDT was found to be less than that for unmodified epoxy. POLYM. ENG. SCI., 47:1881–1888, 2007. © 2007 Society of Plastics Engineers 相似文献
833.
Sarbjit Kaur Raymond A. Cutler Dinesh K. Shetty 《Journal of the American Ceramic Society》2009,92(1):179-185
The fracture toughness of four different silicon carbides was measured using single-edge precracked beam (SEPB) and indentation/strength techniques. Two were development grades with similar microstructures and chemistries, and yet exhibited different fracture modes. The grade that exhibited a predominantly intergranular fracture had an SEPB fracture toughness (6.4 MPa√m) 88% higher than the one that showed primarily a transgranular fracture (3.4 MPa√m). The higher fracture toughness was associated with a modest increase in average strength (25%), although there was a significant increase in the Weibull modulus (11–32). Fracture toughness at short crack lengths was assessed by an indentation method that used fracture strengths, crack lengths at fracture, and a new method of estimating the constant δ that characterizes the residual driving force of the plastic zones based on the stable growth of the indentation cracks from the initial ( c 0 ) to the instability ( c * ) lengths. The results showed a rising crack-growth-resistance behavior for the grade exhibiting intergranular fracture, while the grade showing transgranular fracture had a flat crack-growth resistance. Tests on two commercial grades of silicon carbide showed similar behaviors associated with the respective fracture modes. 相似文献
834.
Yusheng Feng David Fuentes Andrea Hawkins Jon Bass Marissa Nichole Rylander Andrew Elliott Anil Shetty R. Jason Stafford J. Tinsley Oden 《Engineering with Computers》2009,25(1):3-13
Laser surgery, or laser-induced thermal therapy, is a minimally invasive alternative or adjuvant to surgical resection in
treating tumors embedded in vital organs with poorly defined boundaries. Its use, however, is limited due to the lack of precise
control of heating and slow rate of thermal diffusion in the tissue. Nanoparticles, such as nanoshells, can act as intense
heat absorbers when they are injected into tumors. These nanoshells can enhance thermal energy deposition into target regions
to improve the ability for destroying larger cancerous tissue volumes with lower thermal doses. The goal of this paper is
to present an integrated computer model using a so-called nested-block optimization algorithm to simulate laser surgery and
provide transient temperature field predictions. In particular, this algorithm aims to capture changes in optical and thermal
properties due to nanoshell inclusion and tissue property variation during laser surgery. Numerical results show that this
model is able to characterize variation of tissue properties for laser surgical procedures and predict transient temperature
fields comparable to those measured by in vivo magnetic resonance temperature imaging techniques. Note that the computational
approach presented in the study is quite general and can be applied to other types of nanoparticle inclusions. 相似文献
835.
Design and theory of a new compact ultrafine particle sizing instrument, called the miniature electrical-mobility aerosol spectrometer (MEAS), was recently introduced [Ranjan, M., & Dhaniyala, S. (2007). A new miniature electrical spectrometer: Theory and design. Journal of Aerosol Science, 39, 950–963]. In the MEAS, electrostatic precipitation technique is used for both generation of sheath flow and classification of particles based on their electrical mobility. An electrometer-array, connected to the collection electrodes in the classifier section, is used to measure the number of particles collected in the different mobility channels, and these data are inverted using MEAS transfer functions to obtain particle number size distributions. Design of a prototype MEAS and the experimental approach to validate the performance of the individual components of the instrument are presented. Particle size distributions obtained from MEAS measurements compare well with those obtained using a scanning mobility particle sizer (SMPS; TSI 3936), validating theoretical calculations of instrument transfer functions. The operational limits of MEAS are determined from the calculation of error in the inverted size distribution as a function of total particle concentration. This analysis suggests that the designed MEAS can be used for applications such as personal and ambient monitoring under conditions of moderate to high particle concentrations. 相似文献
836.
M. S. Roy Y. S. Deol Yojana Janu A. K. Gautam Manish Kumar P. Balraju G. D. Sharma 《Journal of Materials Science: Materials in Electronics》2009,20(10):984-995
The effect of nitration on the optical, structural, charge-transport and photovoltaic properties of tin (II) phthalocyanine
(SnPc) is investigated in the form of thin film sandwiched devices, by analyzing its electrical, optical and cyclic voltametric
behavior. Further, the effect of nitration on SnPc is described in terms of decrease in HOMO–LUMO position, widening of CT
band in absorption spectra and shifting in characteristics metal sensitive Raman peak contributed by C–N–C bridge bond resulting
rearrangement in molecular stacking. Charge conduction mechanism has been discussed by evaluating charge carrier concentration,
their mobility and the nature of the localized trapping states. The AFM image has been recorded to understand the morphological
change in thin film material in terms of alteration in crystalline nature. The devices show p-type semi conducting behavior
of SnPc as it forms a Schottky barrier with low work function Al electrode (4.28 eV) and Ohmic contact with high work function
ITO electrodes (4.8 eV), respectively. 相似文献
837.
Summary A superswelling poly [N-vinyl pyrrolidone/2-(methacryloyloxyethyl)trimethyl ammonium chloride], poly(NVP/METAC) hydrogels
were prepared by free radical polymerization using ethylene glycol dimethacrylate as crosslinker. The hydrogels were characterized
by FT-IR spectroscopy and their surface morphology was determined using Scanning Electron Microscope (SEM). The influence
of feed composition of both the monomers and crosslinker on equilibrium swelling and dye adsorption properties of the hydrogels
were examined. The equilibrium swelling ratio and binding ratio of the hydrogel/dye systems greatly depends on the METAC and
crosslinker concentration in the gels. The effects of pH of the medium and initial dye concentration on the adsorption were
also studied. The binding ratio of the hydrogel/dye system increases in the following order: OR-II>RO-14>RO-13. 相似文献
838.
Krithi Shetty Shihuai Zhao Wei Cao Upali Siriwardane Naidu V. Seetala Debasish Kuila 《Journal of power sources》2007
Nanoscale Co and Ni catalysts in silica were synthesized using sol–gel method for hydrogen production from steam reforming of methanol (SRM) in silicon microreactors with 50 μm channels. Silica sol–gel support with porous structure gives specific surface area of 452.35 m2 g−1 for Ni/SiO2 and 337.72 m2 g−1 for Co/SiO2. TEM images show the particles size of Ni and Co catalysts to be <10 nm. The EDX results indicate Co and Ni loadings of 5–6 wt.% in silica which is lower than the intended loading of 12 wt.%. The DTA and XRD data suggest that 450 °C is an optimum temperature for catalyst calcination when most of the metal hydroxides are converted to metal oxides without significant particle aggregation to form larger crystallites. SRM reactions show 53% methanol conversion with 74% hydrogen selectivity at 5 μL min−1 and 200 °C for Ni/SiO2 catalyst, which is higher than that for Co/SiO2. The activity of the metal catalysts decrease significantly after SRM reactions over 10 h, and it is consistent with the magnetization (VSM) results indicating that ∼90% of Co and ∼85% of Ni become non-ferromagnetic after 10 h. 相似文献
839.
Chaganti Subba Rao Thadikamala Sathish Brahamaiah Pendyala Thella Prathap Kumar Reddy Shetty Prakasham 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2009,84(2):302-307
BACKGROUND: An unstructured mathematical model was developed to understand information on the relationship between Bacillus circulans growth and metabolism‐related protease production (using logistic and Luedeking–Piret equations respectively) in a batch reactor with respect to glucose consumption and fermentation time. The objective was to develop an indispensable tool for the optimisation, control, design and analysis of alkaline protease production. RESULTS: Biomass growth and enzyme production titres changed with a change in substrate concentration. Modelling analysis of biomass and enzyme production titres at different substrate concentrations revealed significant accuracy in terms of statistical consistency and robustness with respect to fermentation kinetic profiles. CONCLUSION: With the B. circulans strain used, an economic protease yield (2837 × 103 U g?1) with respect to biomass and glucose ratio was achieved at low substrate concentration (10 g L?1). The developed model could be effectively utilised for designing, controlling and up‐scaling the protease production process in high‐density fermentation in selected bioreactors with statistical consistency. Copyright © 2008 Society of Chemical Industry 相似文献
840.
Manish M Paradkar Rekha S Singhal Pushpa R Kulkarni 《International Journal of Dairy Technology》2001,54(1):34-35
A high-performance thin layer chromatography (HPTLC) method for the detection of groundnut oil and palm oil, the main constituents of synthetic milk, was developed. The minimum detectable level of the oils was 80 mg/100 ml. The rosolic acid qualitative test was found to be sensitive enough to detect levels as low as 20 mg/100 ml sodium bicarbonate in milk. 相似文献