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171.
A new cone pressuremeter has been developed at the University of Engineering and Technology, Lahore-Pakistan. The new device is called the Akbar Pressuremeter (APMT). This paper is based on the APMT testing of a cohesive soil deposit comprised of low plastic lean clay (CL) to sandy silty clay (CL-ML). The APMT testing, using a full-displacement technique, standard penetration tests and undisturbed samples, was carried out at two locations. The soil strength and type were determined using the undisturbed samples. The applied pressure-cavity strain curves of the APMT tests performed at different levels were analysed to determine soil strength and stiffness. The undrained shear strength of the undisturbed samples was determined in the laboratory by unconfined compression tests. This paper provides a comparison of the parameters interpreted from the pressuremeter and those determined from other field and laboratory methods. 相似文献
172.
Image analysis is an interesting research area with a large variety of challenging applications. Researchers have worked from
decades on this topic, as witnessed by the scientific literature. However, document image analysis is the special case in
image analysis as their spatial properties are different from natural images. Therefore, the main focus of this paper is to
describe image denoising issues in general and document image issues in particular. Since the field of document processing
is relatively new, it is also dynamic, so current methods have room for improvement and innovations are still being made.
Several algorithms proposed in the literature are described. Critical discussions are reported about the current status of
the field and open problems are highlighted. It is also demonstrated that, there are rarely definitive techniques for all
cases of a certain problem. We surveyed the state of art, analyzed recent trends and tried to identify challenges for future
research in this field. 相似文献
173.
Mitja Uršič Matjaž Leskovar 《International Journal of Heat and Mass Transfer》2012,55(19-20):5350-5356
To improve the determination of heat and mass transfer in fuel-coolant interaction codes appropriate knowledge of the conditions inside the melt droplets is needed. A simplified mathematical model for the determination of the melt droplet conditions is introduced, considering the material physical properties of the melt droplet. Since the computational demand of the mathematical model would significantly increase the overall computational time of the fuel-coolant interaction codes, a simplification based on the temperature profile approach is presented. Finally, a physically-based approach, which is simple enough to be practical for the implementation into computer codes and complex enough to consider adequately the material properties, is proposed and validated. 相似文献
174.
Spark plasma sintering (SPS) is a high current, low voltage process. Nevertheless, the system voltage (3–10 V) can be large enough to produce significant fields across a thin, insulating sample. A lumped circuit model is analyzed to estimate the magnitude of this field in terms of the die geometry. Normalizing the sample voltage with respect to the system voltage, and the die wall thickness to the punch radius preserves generality of the results. It is predicted that if the latter ranges from 0.15 to 0.25, then 30% of the system voltage may be expressed across the sample. Thus, a sample thickness of about 1–2 mm may experience a field of 10–30 V/cm, which would be large enough to induce field‐assisted sintering in yttria‐stabilized zirconia. The results are corroborated with finite element analysis. The contact resistance is assumed to be negligible; finite values of the contact resistance would lead to fields that are higher than predicted. 相似文献
175.
Mahfoozur Rehman Basem A.J.A. Abu Izneid Mohd Zaid Abdullah Mohd Rizal Arshad 《International Journal of Food Science & Technology》2011,46(6):1303-1309
This study deals with the development of a nondestructive impedance spectroscopic technique that may assess the conditions of the fruits to pluck them with the help of robotic arms. Preliminary investigations are made with the help of two‐terminal probe and an accurate LCR meter. The bulk impedance of mango has been measured to characterise raw and ripe fruits. Effective resistance and effective capacitance vs. frequency characteristics have been determined. The bulk effective resistances, of the ripe fruits, are found to be more than those of the raw fruits, in the frequency range of 1–6 kHz. In the same frequency range, effective capacitances of the raw fruits are found more than those of the ripe fruits. In the light of the data obtained, it can be said that the effective resistance may be used to differentiate between raw and ripe fruits in the frequency range of 1–6 kHz. 相似文献
176.
石勉 《武汉工程大学学报》2010,32(10)
专项审计调查主要是针对行业、部门、资金等宏观事项中存在的突出问题,在一定范围内展开调查,较之一般意义上的审计具有更强的灵活性,文章就专项审计调查的特点、原则和4种组织类型进行了分析。专项审计调查对拓宽审计工作视野,提高审计工作的影响力和整体水平发挥了重要作用。 相似文献
177.
H. Uršič M. Hrovat J. Holc J. Tellier S. Drnovšek N. Guiblin B. Dkhil M. Kosec 《Journal of the European Ceramic Society》2010,30(10):2081-2092
Thick films with the nominal composition 0.65Pb(Mg1/3Nb2/3)O3–0.35PbTiO3 (0.65PMN–0.35PT) were produced by screen-printing and firing paste prepared from an organic vehicle and pre-reacted powder. The films were fired for 2 h at 950 °C on alumina (Al2O3), platinum (Pt), aluminium nitride (AlN) and 0.65PMN–0.35PT substrates. The films were then characterized using scanning electron microscopy, X-ray diffraction and dielectric constant measurements. The X-ray analysis did not detect the presence of any undesirable pyrochlore phase, and the differences in the phase compositions were determined with a Rietveld refinement. The variations of the cell parameters vs. the temperature for the monoclinic and tetragonal phases were calculated. It was demonstrated that under similar processing conditions the microstructures, phase compositions and dielectric properties strongly depended on the stress in the thick films due to the different temperature expansion coefficients of the thick films and the substrates. The 0.65PMN–0.35PT thick films under compressive stresses (for the case of the Al2O3 and Pt substrates) exhibited a tetragonal phase in addition to the monoclinic one. The films were sintered to a high density and with a coarse microstructure. These microstructures favour a high dielectric constant. In contrast, for the films under a tensile stress, like the films on AlN substrates, the films were sintered to a lower density and the microstructure consisted of smaller grains. The X-ray analysis showed mainly a monoclinic phase, while the tetragonal phase was not detected. These results indicate the importance of the stresses in 0.65PMN–0.35PT thick films and their influence on the structural and electrical characteristics of the films. 相似文献
178.
179.
兴城气田砂砾岩储层岩性测井解释方法研究 总被引:2,自引:0,他引:2
兴城气田是我国特大气田之一,是目前天然气勘探开发的主要领域。兴城气田储层主要以砂砾岩为主,具有多种岩性并存,成分复杂等特点,在缺少成像及取心资料的情况下,对于砂砾岩储层的识别存在很多困难。本文通过对比各种岩性的测井反映特征,总结了常规测井资料在泥岩,砂岩,砾岩沉积体中反映出的特殊响应特征,对测井曲线进行多种数据变换,建立了岩性与测井曲线值的对应关系图版,应用该图版到该区的其它井取得了较好的效果。 相似文献
180.
Riaz ur Rehman Bakhtawar Khan Tehmina Aziz Faiza Zareen Gul Syeda Nasreen Muhammad Zia 《IET nanobiotechnology / IET》2020,14(5):423
Due to unique physiochemical properties, nanoparticles (NPs) have acquired substantial attention in the field of research. However, threats of ecotoxicity and phytotoxicity have limited their biological applications. In this study in vivo experiments were performed to determine the effect of CuO (12.5, 25 and 50 mg/kg) and ZnO (200, 400 and 600 mg/kg) NPs on growth, and antioxidant activities of Brassica nigra. The results showed that CuO NPs did not affect the seed germination while presence of ZnO NPs in the soil generated an inhibitory effect. Both CuO and ZnO NPs positively influenced the growth of stem and other physiological parameters i.e. stem height increased (23%) at 50 mg/kg CuO while root length decreased (up to 44%) with an increase in the concentration of NPs. Phytochemical screening of apical, middle and basal leaves showed elevated phenolic and flavonoid contents in the range of 15.3–59 μg Gallic Acid Equivalent (GAE)/mg Dry Weight (DW) and 10–35 μg Querceitin Equivalent (QE)/mg DW, respectively, in NPs‐treated plants. Antioxidant activity was higher in CuO NPs‐treated plants as compared to ZnO and control plants. Results conclude that CuO and ZnO NPs at low concentrations can be exploited as nanofertilisers in agriculture fields.Inspec keywords: biochemistry, enzymes, renewable materials, crops, nanoparticles, soil, nanofabrication, zinc compounds, organic compounds, agricultural products, toxicology, nanobiotechnologyOther keywords: antioxidative response, ZnO nanoparticles exposure, soil conditions, unique physiochemical properties, germination, antioxidant activities, brassica nigra plant, antioxidant activity, CuO NP‐treated plants, control plants, ZnO NPs effect, mass 15.3 mug to 59.0 mug, mass 10.0 mug to 35.0 mug, CuO, ZnO 相似文献