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排序方式: 共有454条查询结果,搜索用时 31 毫秒
61.
Golam Rasul Abid Hussain Bidhubhusan Mahapatra Narendra Dangol 《Journal of the science of food and agriculture》2018,98(2):429-438
The status of food and nutrition security and its underlying factors in the Hindu‐Kush Himalayan (HKH) region is investigated. In this region, one third to a half of children (<5 years of age) suffer from stunting, with the incidence of wasting and under‐weight also being very high. The prevalence of stunting, wasting and under‐weight in children is particularly high in some mountain areas such as Meghalaya state in India, the western mountains and far‐western hills of Nepal, Balochistan province in Pakistan, eastern Afghanistan, and Chin state in Myanmar. Food habits in the HKH region are changing. This has led to a deterioration in traditional mountain food systems with a decline in agrobiodiversity. Factors such as high poverty and low dietary energy intakes, a lack of hygienic environments, inadequate nutritional knowledge, and climate change and environmental degradation are also influencing food and nutrition security in the HKH region. To achieve sustainable food and nutrition security in the mountains, this study suggests a multi‐sectoral integrated approach with consideration of nutritional aspects in all development processes dealing with economic, social, agricultural and public health issues. © 2017 Society of Chemical Industry 相似文献
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In this paper we propose a concept and report experimental results based on a circular array of Piezoelectric Wafer Active Sensors (PWASs) for rapid localization and parametric identification of corrosion type damage in metallic plates. Implementation of this circular array of PWASs combines the use of ultrasonic Lamb wave propagation technique and an algorithm based on symmetry breaking in the signal pattern to locate and monitor the growth of a corrosion pit on a metallic plate. Wavelet time-frequency maps of the sensor signals are employed to obtain an insight regarding the effect of corrosion growth on the Lamb wave transmission in time-frequency scale. We present here a method to eliminate the time scale, which helps in identifying easily the signature of damage in the measured signals. The proposed method becomes useful in determining the approximate location of the damage with respect to the location of three neighboring sensors in the circular array. A cumulative damage index is computed from the wavelet coefficients for varying damage sizes and the results appear promising. Damage index is plotted against the damage parameters for frequency sweep of the excitation signal (a windowed sine signal). Results of corrosion damage are compared with circular holes of various sizes to demonstrate the applicability of present method to different types of damage. 相似文献
65.
Raghunath R Tripathi RM Mahapatra S Sadasivan S 《The Science of the total environment》2002,285(1-3):21-27
Selenium (Se) levels in whole blood, serum, urine, muscle and saliva of Mumbai adults have been estimated by differential pulse cathodic stripping voltammetry (DPCSV); the detection limit of Se is 0.05 ng ml(-1). The reliability of estimation is further assessed through the analysis of Standard Reference Materials. The Se levels in whole blood (n = 35) and blood serum (n = 201) of the Mumbai adult population is 99.6 and 100 ng ml(-1); approximately 34.8% of the population have serum Se levels between 80 and 100 ng ml(-1). The blood serum levels of Se for Mumbai adults are comparable to those of whole blood. The mean concentration of Se in urine on a 24-h basis is 5.2 ng ml(-1). Muscle and saliva of the Mumbai adult population contain 195.4 ng g(-1) and 2 ng ml(-1) of Se, respectively. A good correlation between serum Se and dietary Se is observed with a correlation coefficient of 0.89. 相似文献
66.
R. B. Mahapatra J. K. Brimacombe I. V. Samarasekera 《Metallurgical and Materials Transactions B》1991,22(6):875-888
Axial heat-flux profiles have been determined quantitatively from temperature measurements conducted on a slab mold under
routine operating conditions. As in earlier studies, the heat flux was observed to have a maximum value at the meniscus and
to decline with increasing distance down the mold. The mold heat flux increased with increasing casting speed and was greater
with a mold powder having lower viscosity and melting point being applied as lubricant. The heat extraction was largest while
casting 0.29 pet carbon steel and least for a 0.09 pet carbon grade; reducing the depth of the submerged entry nozzle increased
the heat flux slightly in the upper region of the mold. Most significant was the higher heat flux observed at the meniscus
of the outside-radius face, attributable to the locally greater copper plate thickness compared to that of the opposite broad
face. All of the measurements can be explained straightforwardly by heat flow in the vicinity of the meniscus and the resulting
behavior of the so-called slag rim adjacent to the mold wall. It is postulated that the difference in copper plate thickness
between the two broad faces at the meniscus causes the slag rim to be smaller on the outside-radius face which gives rise
to shallower oscillation marks, as observed, higher heat transfer, and a slightly thicker solid shell. The dissimilar behavior
has implications for quality because the inside-radius shell, experiencing reduced heat extraction, cools and shrinks less
than the outside-radius shell. Thus, for a given end-plate taper, the narrow face of the slab adjacent to the inside radius
can push against the end plate, accelerating copper wear, and, owing to squeezing of the broad face, cause an off-corner depression
and subsurface crack toward the mold exit. If this is correct, maintenance of the same copper plate thickness at the meniscus
is fundamental to preventing such an occurrence. Moreover, adjustment of the heat extraction at the meniscus should be achievable
by changing copper plate thickness, mold coating thickness/conductivity, cooling water velocity, cooling channel configuration,
and mold flux composition for a given steel grade.
Formerly Graduate Student, Centre for Metallurgical Process Engineering, The University of British Columbia, 相似文献
67.
R. B. Mahapatra J. K. Brimacombe I. V. Samarasekera N. Walker E. A. Paterson J. D. Young 《Metallurgical and Materials Transactions B》1991,22(6):861-874
An extensive study has been conducted to elucidate mold behavior and its influence on quality during the continuous casting
of slabs. The study combined industrial measurements, mathe matical modeling, and metallographic examination of cast slab
samples. The industrial mea surements involved instrumenting an operating slab mold with 114 thermocouples in order to determine
the axial mold wall temperature profiles for a wide range of casting conditions. A three-dimensional (3-D) heat-flow model
of the mold wall was developed to characterize the heat fluxes in the mold quantitatively from the measured mold temperature
data. Furthermore, heat-flow models were developed to examine steel solidification phenomena and mold flux behavior at the
meniscus. Slab samples collected during the industrial trials were examined metallographically to evaluate the cast structure
and defects. Owing to the length of the study, it is presented in two parts, the first of which describes the experimental
techniques employed in the instrumentation of the mold together with the details of the industrial trials and mold temperature
measurements. Also, the mathematical modeling technique applied to determine the axial heat-flux profiles from the measured
mold temperature data is presented. It is shown that a fully 3-D model of the mold wall is needed to convert the measured
temperatures to heat-flux profiles properly.
Formerly Graduate Student, Centre for Metallurgical Process Engineering, The University of British Columbia
Formerly with Research and Development, Stelco Inc. 相似文献
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69.
X Zhang D Piatier-Tonneau C Auffray R Murali A Mahapatra F Zhang CC Maier H Saragovi MI Greene 《Canadian Metallurgical Quarterly》1996,14(4):472-475
We have developed peptide analogs to analyze precise human CD4 substructures involved in MHC class II binding. Forms of the complementarity determining-like regions (CDRs) of the D1 domain of human CD4 were reproduced as synthetic aromatically modified exocyclic (AME) analogs and tested for their ability to block CD4-MHC II interactions and T cell activation. The exocyclic derived from CDR3 (residues 82-89) of human CD4, which specifically associated with CD4 on the T cell surface to create a heteromeric CD4 complex, blocked IL-2 production and antagonized the normal function of the CD4 receptor. The approach of creating novel synthetic antagonistic receptor complexes may represent a new receptor specific pharmaceutical approach to modulate biological function. 相似文献
70.
印度JSW钢铁公司是一家年产钢700万t的联合钢铁企业,其炼铁单元由2座COREX和3座高炉组成。COREX和高炉用球团由一个年产420万t的带式焙烧机球团厂供给。作为一项重要的冶金性能指标,球团的还原粉化指数(RDI)要求满足COREX和高炉冶炼的要求。通过建立神经元网络模型和敏感度分析,研究了给料率、料层高度、焙烧温度、干透点温度、COREX煤气单耗、膨润土的添加量、生球水分、生球碳含量、以及成品球的MgO、Al2O3含量和碱度等12个因素对球团RDI指标的影响,并对焙烧机生产球团的RDI(-6.3mm)和RDI(-0.5mm)进行了预测。结果表明,球团中MgO、CaO/SiO2,生球碳含量和Al2O3含量对球团RDI指标影响较大。预测结果与实际的数据误差低于4%。研究得出:①生球的MgO、氧化铝和碳含量以及二元碱度对球团RDI有重要影响。②随着球团MgO含量和球团二元碱度的升高,球团RDI(-6.3mm)和RDI(-0.5mm)得到改善。③随着生球中氧化铝含量的增加,球团RDI升高,因此应尽量使用低氧化铝含量的铁矿粉来降低球团中的氧化铝。随着生球中氧化铝和碳含量的增加,球团RDI(-6.3mm)和RDI(-0.5mm)有所降低。④提高球团二元碱度和MgO含量的同时,降低生球碳含量可以改善球团的RDI。因此需要对它们的配比进行优化。⑤二元碱度0.50~0.55,MgO质量分数0.35%~0.45%,生球碳质量分数1.15%~1.20%,焙烧球氧化铝质量分数低于2.5%,FeO质量分数低于0.60%时,可望得到较低的RDI。⑥相对于球团中的碳和CaO含量,最优的焙烧温度可以改善球团的RDI(-6.3mm)和RDI(-0.5mm)。⑦高给料率和较高的料层高度会使球团的RDI(-6.3mm)和RDI(-0.5mm)升高。 相似文献