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91.
Lubricant films containing colloidal overbased calcium salts have particular effects on detergency and on the wear process. The mechanical properties of such boundary films are very dependent on the process conditions, and are essentially a result of physico-chemical transformations of the colloid. Three types of films were compared: a film obtained by the drying of the base solvent, a film due to the compaction of the colloid between two steel surfaces, and a friction film obtained with this type of lubricant. Adsorption, compaction, and shear transformations induce a solid film. The pressure effect on the frictional behaviour of these colloidal films has been investigated using a surface force apparatus for low contact pressure (104 to 106 Pa), and using tribometers supporting heavy loads for the analysis of the high pressure domain. Above a critical pressure, evaluated at 106 Pa, the colloidal film does not flow, but forms a compacted mattress sliding on the surface plane and squeezing a molecular layer of lubricant. 相似文献
92.
Vincent Nicolas Fernanda Vanin David Grenier Tiphaine Lucas Christophe Doursat Denis Flick 《American Institute of Chemical Engineers》2016,62(11):3847-3863
A two dimensional model of bread baking was developed including, for the first time, the dependence of dough viscosity on both temperature and moisture content, the carbon dioxide dissolved from liquid water together with gas generation from yeast at the beginning of baking and the shrinkage due to dough drying. Particular attention was paid to experimental validation of both overall and local variables such as local temperature, overall mass loss, and local moisture content, overall CO2 released into the oven, and overall deformation and local expansion or shrinkage. Sensitivity studies on generation of carbon dioxide, gravity, and shrinkage are presented to discuss their influences on bread geometry, porosity (reflecting the alveolar structure) and gas pressure. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3847–3863, 2016 相似文献
93.
Modelling of flocculation using a population balance equation 总被引:1,自引:0,他引:1
Carole Coufort Denis Bouyer Alain Lin Benoît Haut 《Chemical Engineering and Processing: Process Intensification》2007,46(12):1264-1273
In this paper, a model based on a population balance equation (PBE) is developed. It aims at reproducing experimental floc size distributions obtained at steady state in a jar-test. The objective is to develop a simple model, based on physical phenomena, and that does not contain any adjustable parameters. Floc size distributions obtained using a part of a particle image velocimetry (PIV) device and image analysis are used to develop mathematical expressions for the aggregation and breakage kernels. A critical volume beyond which breakage is of significant importance is identified and related to the hydrodynamics. Hydrodynamic sequencing allows the distribution of the daughter particles resulting from a breakage event to be established. The model is finally successfully validated against experimental results. 相似文献
94.
Oleg A. Kazantsev Dmitry V. Orekhov Denis M. Kamorin Maria V. Savinova 《Designed Monomers and Polymers》2017,20(1):136-143
Concentration effects in the base-catalyzed hydrolysis of water-soluble methacrylates (3-(N,N-dimethylaminoethyl) methacrylate (DMAEMA), 2-hydroxyethyl methacrylate (HEMA) and oligo(ethylene glycol) methacrylates (OEGMAs)) have been studied. These monomers are rapidly hydrolyzed in the presence of bases at the room temperature in dilute aqueous solutions, but the reaction rate decreases sharply in highly concentrated solutions. A clear correlation was found between a form of the viscosity isotherm for DMAEMA solutions and the concentration dependence of the autocatalytic hydrolysis rate which indicates the connection of process kinetics with the structure of solutions. These data should be considered when carrying out homo- and copolymerization of the previously mentioned monomers in aqueous solutions. 相似文献
95.
电卡效应是极性材料中极化强度和温度的相互作用, 具有电卡效应的铁电陶瓷材料在高效固态制冷领域有很好的应用前景。本研究以Pb0.3CaxSr0.7-xTiO3 [PCST(x), x = 0.00, 0.05, 0.10, 0.15]陶瓷为对象, 系统研究了在电场作用下Ca含量对材料介电性能和铁电性能的影响, 并通过间接法计算了不同温度下材料的电卡温变。研究结果显示: Ca含量可显著调控PCST陶瓷的弥散相变特性, PCST(0.05)的相变弥散因子随外加电场的增大而增大, 可利用弥散相变在较宽温度区间内获得较大的电卡效应。经计算可得: PCST(0.05)在室温下可产生1.71 K的温变。当电场为8 kV/mm时, PCST(0.05)陶瓷在5~70 ℃的温度范围内, 绝热温变均大于1 K, 表现出优异的电卡效应。 相似文献
96.
M. S. Maharajan T. Abirami Irina V. Pustokhina Denis A. Pustokhin K. Shankar 《计算机、材料和连续体(英文)》2021,68(3):2995-3013
Wireless Sensor Networks (WSN) started gaining attention due to its wide application in the fields of data collection and information processing. The recent advancements in multimedia sensors demand the Quality of Service (QoS) be maintained up to certain standards. The restrictions and requirements in QoS management completely depend upon the nature of target application. Some of the major QoS parameters in WSN are energy efficiency, network lifetime, delay and throughput. In this scenario, clustering and routing are considered as the most effective techniques to meet the demands of QoS. Since they are treated as NP (Non-deterministic Polynomial-time) hard problem, Swarm Intelligence (SI) techniques can be implemented. The current research work introduces a new QoS aware Clustering and Routing-based technique using Swarm Intelligence (QoSCRSI) algorithm. The proposed QoSCRSI technique performs two-level clustering and proficient routing. Initially, the fuzzy is hybridized with Glowworm Swarm Optimization (GSO)-based clustering (HFGSOC) technique for optimal selection of Cluster Heads (CHs). Here, Quantum Salp Swarm optimization Algorithm (QSSA)-based routing technique (QSSAR) is utilized to select the possible routes in the network. In order to evaluate the performance of the proposed QoSCRSI technique, the authors conducted extensive simulation analysis with varying node counts. The experimental outcomes, obtained from the proposed QoSCRSI technique, apparently proved that the technique is better compared to other state-of-the-art techniques in terms of energy efficiency, network lifetime, overhead, throughput, and delay. 相似文献
97.
This paper summarizes the present status of a computer code that describes some of the main phenomena occurring in a nuclear fuel rod throughout its life. Temperature distribution, thermal expansion, elastic and plastic strains, creep, mechanical interaction between pellet and cladding, fission gas release, gas mixing, swelling, and densification are modeled. The modular structure of the code allows for the incorporation of models to simulate different phenomena and material properties. Collapsible rods can be also simulated.The code is bidimensional, assumes cylindrical symmetry for the rod and uses the finite element method to integrate the differential equations. The stress–strain and heat conduction problems are nonlinear due to plasticity and to the temperature dependence of the thermal conductivity. The fission gas inventory is calculated with a diffusion model, assuming spherical grains and using a one-dimensional finite element scheme. Pressure increase, swelling and densification are coupled with the stress field.Good results are obtained for the simulation of the irradiation tests of the first argentine prototypes of MOX fuels, where the bamboo effect is clearly observed, and of the FUMEX series for the fuel centerline temperature, the inside rod pressure and the fractional gas release. 相似文献
98.
Iskandar Abdullaev Alexander Platonov Denis Sorokin 《The International journal of environmental studies》2013,70(1):151-168
Contemporary water management decisions use many sources and forms of data. The paper discusses the implementation results of data management activities in the water sector carried out in five countries of the Central Asia region. Geoinformation systems, remote sensing tools and databases have been applied worldwide for improving water resources management with differing levels of success. Water management organisations, equipped with data management tools will have better capacities to adapt their decision-making in the changing availability and scarcity of water resources. Application of data management tools for improving collection, storage and processing of data and information are a first step towards improved water governance. 相似文献
99.
S. O. Denis Russell 《Civil Engineering and Environmental Systems》2013,30(1):9-12
The drive to develop expert systems is forcing would-be developers to examine and make explicit the mental processes which experts use. Much of what an expert actually does is carried out intuitively and without any conscious thought. The procedures and mental processes used in civil engineering design involve a ‘creative phase’, where the design first takes shape and then ‘evolves’, and a ‘checking phase’ to ensure that it will be satisfactory. Experience and judgement play large roles in both phases. In this paper, the role of experience and how it is gained are examined. Defining experience is important not only for expert systems designers but also for the education and training of future design engineers. 相似文献
100.
Liu Jingjing Fallah-Mehrjardi Ata Shishin Denis Jak Evgueni Dorreen Mark Taylor Mark 《Metallurgical and Materials Transactions B》2017,48(6):3185-3195
Metallurgical and Materials Transactions B - In an aluminum electrolysis cell, the side ledge forms on side walls to protect it from the corrosive cryolitic bath. In this study, a series of... 相似文献