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排序方式: 共有369条查询结果,搜索用时 31 毫秒
31.
Nezu Arthur M.; Nezu Christine Maguth; Jain Diwakar 《Canadian Metallurgical Quarterly》2008,27(6):829
Objective: The present study tested the hypothesis that social problem solving (SPS) served to mediate the relationship between preceived stress and noncardiac chest pain (NCCP). Design: Adults undergoing stress myocardial perfusion imaging (MPI) to determine the presence of underlying cardiovascular disease related to the experience of chest pain were recruited prior to stress testing to complete a series of self-report inventories. Main Outcome Measures: MPI results were used to identify individuals with NCCP (N = 166; 91 men, 75 women; mean age = 53.92 years, SD = 11.98). Measures included perceived stress, SPS, and chest pain frequency and intensity. Results: In direct tests of the mediational effects of SPS, it was found that two problem-solving dimensions, negative problem orientation and rational problem solving, each served as significant mediators of the effects of stress on both NCCP intensity and frequency. Conclusion: These results support a mediational analysis of NCCP that includes stress and SPS. As such, it identifies SPS as a potentially important clinical target to consider when developing future psychosocial-based therapy protocols for treating individuals with NCCP. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
32.
Bastihalli Tukaram Diwakar Pinto Kumar Dutta Belur Ramaswamy Lokesh Kamatham Akhilender Naidu 《Journal of the American Oil Chemists' Society》2010,87(5):539-548
Garden cress (Lepidium sativum L.) is an edible, underutilised herb, grown mainly for its seeds in India. Physicochemical properties, minor components (unsaponifiable
matter, tocopherols, carotenoids), fatty acid composition and storage stability of garden cress seed oil (GCO) were studied.
Cold press, solvent and supercritical CO2 extraction methods were employed to extract the oil. The total oil content of garden cress (GC) seeds was 21.54, 18.15 and
12.60% respectively by solvent, supercritical CO2 and cold press methods. The physical properties of GCO extracted by the above methods were similar in terms of refractive
index, specific gravity and viscosity. However, cold pressed oil showed low PV and FFA compared to the oil extracted by other
methods. α-Linolenic acid (34%) was the major fatty acid in GCO followed by oleic (22%), linoleic (11.8%), eicosanoic (12%),
palmitic (10.1%) erucic (4.4%), arachidic (3.4%) and stearic acids (2.9%). Oleic acid (39.9%) and α-linolenic acid (42.1%)
were the predominant fatty acids at the sn-2 position. The total tocopherol and carotenoid content of GCO was 327.42 and 1.0 μmol/100 g oil, respectively. The oil was
stable up to 4 months at 4 °C. Tocopherol and BHT offered the least protection, while ascorbyl palmitate (200 ppm) offered
the maximum protection to the oil, when subjected to the accelerated oxidative stability test. Thus GCO can be considered
as a fairly stable oil with a high content of α-linolenic acid. 相似文献
33.
Wenbo Wang Jitendra Paliwal 《Sensing and Instrumentation for Food Quality and Safety》2007,1(4):193-207
Over the last two decades, near-infrared spectroscopy (NIRS) has established itself as a non-destructive analytical technique
in a variety of disciplines. However, recent technological advancements in hardware design and data mining techniques have
unleashed the potential of NIRS to become a tool of choice for routine analyses of agricultural products. The current paper
synthesizes the status of NIRS in the agri-food industry in terms of hardware and software development as well as the direction
in which the NIRS research is headed. An extensive review of literature reveals that the emphasis on hardware development
is focused on developing compact, robust, and portable spectrometers and hyperspectral imaging (HSI) systems. The software
development on the other hand is geared towards developing better preprocessing, analyses, and modeling techniques using chemometrics,
support vector machines, and artificial neural networks. The four main agri-food sectors identified to be the beneficiaries
of this research revolution are grain quality monitoring; post-harvest handling of fruits and vegetables; identification of
contaminants in animal produce and feed; and food safety and authenticity. Apart from discussing the aforementioned topics,
the paper also provides food scientists some working knowledge on parameters crucial to the performance of spectral and imaging
systems. It is expected that further development of NIRS will help agricultural and food scientists to enhance the quality
and safety of our food. 相似文献
34.
In this mathematical presentation, we examined the significance of Hall current on MHD buoyancy-driven boundary layer flow of a Ti6Al4V-H2O based nanofluid past a vertical surface implanted in a uniform permeable region. The vertical surface is considered to be magnetized and induced magnetic field (IMF) impacts are also considered. The nondimensional flow model is solved with the assistance of the two-term perturbation scheme. Various results are obtained by numerical computation for different significant parameters. These results are presented and analyzed in graphical and tabular form. In the boundary layer domain, the transpiration velocity across the surface tends to diminish the main flow, IMF along the main flow, fluid temperature, and concentration. It is remarkably noted that IMF along the main flow grows for incrementing values of volume fraction coefficient of nanofluid. In the magnetic boundary layer domain, the main flow and IMF along the main flow grow with Hall current. Furthermore, it is seen that for the progressing values of magnetic Prandtl number, the main flow reduces while normal flow and IMF along the main flow is induced in the boundary layer domain. 相似文献
35.
The key objective in this study is to examine the heat and mass transport behavior of magnetohydrodynamic elastic-viscous fluid flow over a vertically oriented magnetized surface placed in a uniform permeable regime with magnetic and thermo diffusions. The fluid is partially ionized and permeated to flow in the presence of a strong magnetic field domain. Hence the Hall current effect is considered in this investigation. The significance of rotation and induced magnetic field on the flowing nature are also scrutinized in this study. The mathematical model of the problem is converted to a similar model by introducing suitable nondimensional variables. To obtain the closed-form solutions of the flow leading equations, the regular perturbation analysis is utilized. For the exhibition of results, figures and tables are generated with the assistance of scientific computation software MATHEMATICA. Computed results are validated with the existing result in the limiting case. Such an investigation is important in evaluating the flow characteristics of low magnetic diffusive viscoelastic fluid. A noteworthy result seen is that magnetic diffusion significantly controls the fluid flow by altering the magnetic drag force. Mass diffusion factor brings an increase in the fluid velocity. Furthermore, we observed that the surface current density along the principal flow direction is significantly reduced by magnetic diffusion and mass diffusion factor. 相似文献
36.
37.
Aqueous sodium and potassium carbonates have been photoreduced in the presence of Toluidine Blue solution (which is also the photocatalyst). The photocatalytic formation of formic acid and formaldehyde was measured spectrophotometrically using Nash reagent. The effect of variation of various parameters like pH, amount of photocatalyst (Toluidine Blue concentration), concentration of Na2CO3 and K2CO3, light intensity, etc., on the yield of photoproducts was also investigated. A tentative mechanism for this reduction has been proposed. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
38.
39.
In this paper, a fault direction estimation algorithm is proposed for a double-circuit line with thyristor controlled series capacitor (TCSC) using principal component analysis (PCA)-based technique. In case of PCA, an orthogonal transformation is used to convert correlated variables into linearly uncorrelated variables called principal components. Fault in such a compensated line leads to voltage inversion, current inversion, and subsynchronous resonance situations, which affect the performance of the conventional direction estimation process. Transients associated with metal oxide varistor (MOV) operation and control action associated with TCSC, further modulate equivalent impedance of TCSC and MOV combination. In the proposed approach, PCA of angles between positive and negative sequence components of voltage current has been carried out to extract the pattern and to declare the fault direction accurately. The double-circuit line with TCSC is simulated using PSCAD/EMTDC software. The performance of the proposed technique is tested for numerous test cases, and it was found to be accurate. 相似文献
40.