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1.
Investigation on the miniaturized parallel multichannel-based devices packed with glass beads to improve the mass exchange execution is the critical focal point of the current study. One of the essential parameters to specify the miniaturized devices' flow distribution is the residence time distribution (RTD). In the present context, the RTDs of a liquid tracer were investigated for the air-water multiphase flows (concurrent) across the multichannel-based miniaturized devices (comprising of 11 similar dimensional parallel channels). The devices were variable in height and packed with glass beads. The conductivity estimations generated the RTD curves and were addressed by the axial dispersion model (ADM). The fluid-flow rates differed within the range of 5–23 ml min−1. The axial dispersion coefficients and the rate of the specific energy dispersion were investigated. The effects of pressure difference and geometry on the hydrodynamic attributes and mixing properties were well-illustrated, and the new correlations were suggested. 相似文献
2.
In this present work, Ca-alginate-biochar adsorbent has been synthesized, characterized and tested its effectiveness in the removal of aqueous phase Zn2+ metal. The removal efficiency was studied under various physicochemical process parameters. External mass transfer model, intraparticle diffusion model and pseudo-first-order and pseudo-second-order models were used to fit the experimental Zn2+ adoption kinetic results and to identify the mechanism of adsorption. The desorption studies indicate the possibilities of ion-exchange and physical–chemical adsorption of Zn2+. The adsorption was best described by Langmuir isotherm model. Thermodynamic parameters suggested that the adsorption process becomes spontaneous, endothermic and irreversible in nature. 相似文献
3.
In the present study, oil palm wood flour (OPWF) particles with less than 250 μm sizes have been used as filler materials
in the woven-glass-fiber reinforced epoxy composite. The hybrid composites were fabricated using a hand lay-up method and
cured at room temperature under a compressive load of 196 N (20 kg). The OPWF of 2.5 to 10 parts per hundred (pph) by weight
was used to evaluate its effect on impact strength of the hybrid composites at a range of temperature from −50 to 50 °C. The
impact strength, evaluated using V-notch Charpy method, showed reduction with increasing filler content up to 5 pph and then
the strength increment in those composites containing more than 5 pph OPWF. More severe damages were found in specimens with
higher filler contents resulting higher energy absorption during impact. The composites with a large amount of OPWF particles
deflected crack propagation paths or created obstacles at the crack tips and increased toughness of the composites. The impact
strength was found to decrease when the samples fractured at subzero temperatures and this happened because of the reduction
of the matrix ductility at lower temperatures. 相似文献
4.
Glaucio H. Paulino Ivan F. M. Menezes Marcelo Gattass Subrata Mukherjee 《International journal for numerical methods in engineering》1994,37(9):1511-1530
A Finite Element Graph (FEG) is defined here as a nodal graph (G), a dual graph (G*), or a communication graph (G˙) associated with a generic finite element mesh. The Laplacian matrix ( L (G), L (G*) or L (G˙)), used for the study of spectral properties of an FEG, is constructed from usual vertex and edge connectivities of a graph. An automatic algorithm, based on spectral properties of an FEG (G, G* or G˙), is proposed to reorder the nodes and/or elements of the associated finite element mesh. The new algorithm is called Spectral PEG Resequencing (SFR). This algorithm uses global information in the graph, it does not depend on a pseudoperipheral vertex in the resequencing process, and it does not use any kind of level structure of the graph. Moreover, the SFR algorithm is of special advantage in computing environments with vector and parallel processing capabilities. Nodes or elements in the mesh can be reordered depending on the use of an adequate graph representation associated with the mesh. If G is used, then the nodes in the mesh are properly reordered for achieving profile and wavefront reduction of the finite element stiffness matrix. If either G* or G˙ is used, then the elements in the mesh are suitably reordered for a finite element frontai solver, A unified approach involving FEGs and finite element concepts is presented. Conclusions are inferred and possible extensions of this research are pointed out. In Part II of this work,1 the computational implementation of the SFR algorithm is described and several numerical examples are presented. The examples emphasize important theoretical, numerical and practical aspects of the new resequencing method. 相似文献
5.
Energy efficiency for gas liquid mixing in a modified downflow bubble column reactor has been analyzed in this paper. Efficiencies of the different parts of the bubble column have been assessed on the basis of energy dissipation. Prediction of the energy dissipation coefficient as well as energy utilization efficiency due to gas‐liquid mixing as a function of different physical, geometric and dynamic variables of the system has been done by correlation method. The distribution of energy utilization in the different zones of the column has also been analyzed. Experiments were carried out with air‐water and air‐aqueous solutions of carboxy methyl cellulose with different concentrations. 相似文献
6.
Data-driven next-generation smart grid towards sustainable energy evolution: techniques and technology review 下载免费PDF全文
Faiaz Ahsan Nazia Hasan Dan Subrata K. Sarker Li Li S. M. Muyeen Md. Firoj Ali Zinat Tasneem Md. Mehedi Hasan Sarafat Hussain Abhi Md. Robiul Islam Md. Hafz Ahame Md. Manirul Islam Sajal K. Das Md. Faisal R. Badal Prangon Das 《电力系统保护与控制》2023,8(3):696-737
Meteorological changes urge engineering communities to look for sustainable and clean energy technologies to keep the environment safe by reducing CO2 emissions. The structure of these technologies relies on the deep integration of advanced data-driven techniques which can ensure efcient energy generation, transmission, and distribution. After conducting thorough research for more than a decade, the concept of the smart grid (SG) has emerged, and its practice around the world paves the ways for efcient use of reliable energy technology. However, many developing features evoke keen interest and their improvements can be regarded as the next-generation smart grid (NGSG). Also, to deal with the non-linearity and uncertainty, the emergence of data-driven NGSG technology can
become a great initiative to reduce the diverse impact of non-linearity. This paper exhibits the conceptual framework of NGSG by enabling some intelligent technical features to ensure its reliable operation, including intelligent control, agent-based energy conversion, edge computing for energy management, internet of things (IoT) enabled inverter, agent-oriented demand side management, etc. Also, a study on the development of data-driven NGSG is discussed to facilitate the use of emerging data-driven techniques (DDTs) for the sustainable operation of the SG. The prospects of DDTs in the NGSG and their adaptation challenges in real-time are also explored in this paper from various points of view including engineering, technology, et al. Finally, the trends of DDTs towards securing sustainable and clean energy evolution from the NGSG technology in order to keep the environment safe is also studied, while some major future issues are highlighted. This paper can ofer extended support for engineers and researchers in the context of data-driven technology and the SG. 相似文献
7.
An object-oriented framework in essence defines an architecture for a family of applications or subsystems in a given domain. Every application in the family obeys these architectural restrictions. Such frameworks are typically delivered as collections of inter-dependent abstract classes, together with their concrete subclasses. The abstract classes and their interdependencies implicitly realize the architecture. Developing a new application reusing classes of a framework requires a thorough understanding of the framework architecture.We introduce an approach called Design by Framework Completion, in which an exemplar (an executable visual model for a minimal instantiation of the architecture) is used for documenting frameworks. We propose exploration of exemplars as a means for learning the architecture, following which new applications can be built by replacing selected pieces of the exemplar. For the piece to be replaced, the inheritance lattice around its class provides the space of alternatives, one of these classes may be suitably adapted (say, by sub-classing) to create the new replacement.Design by Framework Completion proposes a paradigm shift when designing in presence of reusable components: It enables a much simpler top-down approach for creating applications, as opposed to the prevalent search for components and assemble them bottom-up strategy. We believe that this paradigm shift is essential because components can only be fitted together if they all obey the same architectural rules that govern the framework. 相似文献
8.
In this article, free space capacitance of dielectric‐coated conducting curvilinear surfaces is obtained using method of moments (MOM). The surfaces are discretized using triangular subsections. The curvilinear surfaces are represented by quadratic parametric elements. The MOM based on the pulse basis function and point matching is used. The integrand is divided into a regular and a singular part. The regular part of the integral is numerically evaluated by using the Gaussian quadrature algorithm for triangles. The Duffy transformation is used to evaluate the singular part of the integrals. Computed results are given for the capacitance of the dielectric‐coated conducting cylinder of finite axial length and truncated cone, and compared with the previously published results. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010. 相似文献
9.
Our study illustrates the development of a microfluidics (MF) platform combining fluorescence microscopy and femtosecond/picosecond-resolved spectroscopy to investigate ultrafast chemical processes in liquid-phase diffusion-controlled reactions. By controlling the flow rates of two reactants in a specially designed MF chip, sub-100 ns time resolution for the exploration of chemical intermediates of the reaction in the MF channel has been achieved. Our system clearly rules out the possibility of formation of any intermediate reaction product in a so-called fast ionic reaction between sodium hydroxide and phenolphthalein, and reveals a microsecond time scale associated with the formation of the reaction product. We have also used the developed system for the investigation of intermediate states in the molecular recognition of various macromolecular self-assemblies (micelles) and genomic DNA by small organic ligands (Hoechst 33258 and ethidium bromide). We propose our MF-based system to be an alternative to the existing millisecond-resolved "stopped-flow" technique for a broad range of time-resolved (sub-100 ns to minutes) experiments on complex chemical∕biological systems. 相似文献
10.
Cladding is the process of depositing a superior built-up layer by fusion on a substrate. In blown powder laser cladding process, the powder travels across the laser path, gets heated up by absorbing laser energy, and finally melts on the substrate under the intense laser beam; as the substrate moves away this melt pool solidifies to form a continuous built-up layer. The laser energy is partly absorbed by the solid powder during its flight path (termed preheating) and partly by the top surface of the melt pool. In the present study a two-dimensional conduction heat transfer equation has been solved using finite-volume method to model the cladding process. It is observed that preheating allows higher scanning speed resulting in thin clad layer with low dilution. Preheating also permits high powder feed rate resulting in thick cladding with low dilution. 相似文献