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Shilpa Sivashankar Sumeyra Agambayev Yousof Mashraei Er Qiang Li Sigurdur T. Thoroddsen Khaled Nabil Salama 《Biomicrofluidics》2016,10(3)
This paper proposes a new “twisted” 3D microfluidic mixer fabricated by a laser writing/microfabrication technique. Effective and efficient mixing using the twisted micromixers can be obtained by combining two general chaotic mixing mechanisms: splitting/recombining and chaotic advection. The lamination of mixer units provides the splitting and recombination mechanism when the quadrant of circles is arranged in a two-layered serial arrangement of mixing units. The overall 3D path of the microchannel introduces the advection. An experimental investigation using chemical solutions revealed that these novel 3D passive microfluidic mixers were stable and could be operated at a wide range of flow rates. This micromixer finds application in the manipulation of tiny volumes of liquids that are crucial in diagnostics. The mixing performance was evaluated by dye visualization, and using a pH test that determined the chemical reaction of the solutions. A comparison of the tornado-mixer with this twisted micromixer was made to evaluate the efficiency of mixing. The efficiency of mixing was calculated within the channel by acquiring intensities using ImageJ software. Results suggested that efficient mixing can be obtained when more than 3 units were consecutively placed. The geometry of the device, which has a length of 30 mm, enables the device to be integrated with micro total analysis systems and other lab-on-chip devices. 相似文献
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This article presents a new approach to modeling information flows within today's information systems environments characterized by electronic commerce. We treat information as a resource whose value is fundamentally multidimensional in nature. In this article we consider the economic and psychological dimensions of the value of information. It is argued that it is meaningless to model the value of information in isolation away from the context and the specific parties between which this information is exchanged. We therefore focus exclusively on modeling information flows rather than information itself. To achieve this, we propose a formal framework for describing transactions involving information flows. The framework consists of a generalized model for representing information transactions and for defining a set of fundamental properties of multiparty transactions. These properties are fairness, constructiveness, and monopoly. Where applicable, they are defined for individuals, transactions, and a system of transactions. The proposed model reveals the nature of individual transactions and markets, and consequently has important implications for simulation of market scenarios and to help arrive at effective policies for pricing and market regulations. 相似文献
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A parametric study on the contact stress of half toroidal continuously variable transmission 总被引：2，自引：0，他引：2
Nabil Abdulla Atti QIN Datong SHI Wankai LI Huaying The State Key Laboratory of Mechanical Transmission Chongqing University Chongqing P.R. China Faculty of Engineering Helwan University Matari Egypt College of Agricultural Engineeri 《重庆大学学报(英文版)》2003,2(2)
1. Introduction A toroidal continuously variable transmission (CVT) that uses a traction drive to transmit torque has a vastly larger torque capacity than a conventional CVT. This transmission technology has attracted considerable interest owing to its capability in substantially improving vehicle fuel economy and power performance [1]. The half toroidal CVT transmits torque by means of shear resistance of the traction fluid film taking advantage of the property of the fluid solidificatio… 相似文献
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Aqilah Nawwarah H.A. Rajak Dk. Nurul Najiah Pg Abu Bakar Nur Dina Azyyati Lajim Nurul Hikmatull Su’aidah Haji Kamarulzaman Siti Nur Fakhrinah Haji Karim Mohammad Nabil Almunawar 《Education and Information Technologies》2018,23(6):2341-2361
This research studies on the e-learning services acceptance in higher education institutions in Brunei Darussalam. This research has seven hypotheses, relating to independent, intermediary, and dependent variables. The independent variables include lecturer’s characteristics, design of learning contents, teaching materials, and playfulness; while the intermediary variables are perceived benefits and perceived ease of use. On the other hand, the dependent variable in this research is the intention to use e-learning. Multiple regression analysis were conducted to test the hypotheses proposed. Data analysis from this research has confirmed that the lecturer’s characteristics, teaching materials, perceived ease of use and the intention to use e-learning corresponds to the perceived benefits. Meanwhile, the design of learning content and the intention to use e-learning are positively related to the perceived ease of use and lastly, the variable playfulness is positively related to the intention to use e-learning. 相似文献
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The purpose of this paper is to gain a better understanding of the processes involved in transferring knowledge into action. Obviously an interesting subject of research, it is worthwhile delving into the role played by knowledge brokers in bridging the gap between research and practice. This paper investigates the relationship between organizational climate and brokers’ knowledge transfer activities. The structural equation model was tested, using survey data from 301 respondents who primarily carry out their professional activities in health services, such as knowledge brokers. The results suggest two major findings: first, that the organizational climate as a multidimensional concept has a direct positive impact on the brokers’ knowledge transfer activities; secondly, that the organizational climate, characterized by the autonomy granted to brokers and a cooperative climate play an indirect role in affecting the knowledge transfer activities through the mediation of the organizational support provided to brokers. 相似文献
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How do knowledge-intensive business services (KIBS) protect their inventions from imitation by rival firms when choosing among various protection mechanisms? Data from the 2003 Statistics Canada Innovation Survey on services are used to investigate this issue by looking into complementarities, substitution and independence among eight protection mechanisms. A Multivariate Probit (MVP) model is estimated to take into account the fact that KIBS simultaneously consider many alternative intellectual property (IP) protection methods when they attempt to protect their innovations. Results show that patents, registration of design patterns, trademarks, secrecy and lead-time advantages over competitors constitute legal and informal methods that are used jointly. These complementarities suggest that IP protection mechanisms that are interdependent and reinforce each other to protect innovations from imitation by rival firms constitute a pattern on which firms rely to protect their innovations from imitation. A second pattern is based on the fact that KIBS rely on patents and complexity of designs as substitutes, and tend to use registration of design patterns and complexity of designs as substitutes in protecting their innovations from imitation. A third emerging pattern concerns protection mechanisms that are independent from each other and exhibit no synergy, and do not reinforce each other to protect innovations from imitation by other firms. 相似文献
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This paper addresses a crucial question: Which factors explain the choices of institutional structures made by university researchers? The main findings of the study point to the central importance of publication assets, coordination costs, additional funding, and membership in the disciplines of engineering, natural sciences and health sciences as factors affecting the choices of institutional structures university researchers make when they become involved in collaborative research projects. On the other hand, the number of years researchers have been involved in collaborative research, the capture of additional publications linked to involvement in collaborative research, the importance of administrative burdens and the time required to coordinate collaborative research were demonstrated to be unimportant in explaining these choices. 相似文献
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Three groups of college students were given instructions using different testing techniques to determine whether the superior performance obtained with Programmed Student Achievement (PA) was due to a Hawthorne Effect. PA students, operating under the consequence of failing the course if they failed to evidence criterion performance (100% mastery) on weekly quizzes, exhibited superior performance, relative to control groups, on the weekly quizzes and on an unannounced retention test. The results seem to preclude any attempt to interpret the effectiveness of Programmed Student Achievement on the basis of a Hawthorne Effect. 相似文献
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ALIAmirIbrahim QINDa-tong ATTIANabilAbdulla 《重庆大学学报(英文版)》2004,3(2):38-42
In recent years, the sustainable development of automatic manual transmissions (AMTs) control in vehicles is conspicuous. The control applications have grown fast and steadily due to the tremendous progress in power electronics components and the control software that enhance the requirements for delivering higher vehicles performance. AMTs control strategies achieve a reduction in the driveline dynamic oscillations behavior during gear shifting and clutch starting up processes. AMTs future expectations are an increase of torque capacity, more speed ratios and the development of advanced and efficient electronic control systems. This paper concerns with the progressing view of AMTs in the past, today and future, gives an overview of the potential dynamic problems concerned with AMTs and some control strategies used to solve those problems. 相似文献