Assessment of an active-cooling micro-channel heat sink device,using electro-osmotic flow

Non-uniform heat flux generated by microchips causes “hot spots” in very small areas on the microchip surface. These hot spots are generated by the logic blocks in the microchip bay; however, memory blocks generate lower heat flux on contrast. The goal of this research is to design, fabricate, and test an active cooling micro-channel heat sink device that can operate under atmospheric pressure while achieving high-heat dissipation rate with a reduced chip-backside volume, particularly for spot cooling applications. An experimental setup was assembled and electro-osmotic flow (EOF) was used thus eliminating high pressure pumping system. A flow rate of 82 μL/min was achieved at 400 V of applied EOF voltage. An increase in the cooling fluid (buffer) temperature of 9.6 °C, 29.9 °C, 54.3 °C, and 80.1 °C was achieved for 0.4 W, 1.2 W, 2.1 W, and 4 W of heating powers, respectively. The substrate temperature at the middle of the microchannel was below 80.5 °C for all input power values. The maximum increase in the cooling fluid temperature due to the joule heating was 4.5 °C for 400 V of applied EOF voltage. Numerical calculations of temperatures and flow were conducted and the results were compared to experimental data. Nusselt number (Nu) for the 4 W case reached a maximum of 5.48 at the channel entrance and decreased to reach 4.56 for the rest of the channel. Nu number for EOF was about 10% higher when compared to the pressure driven flow. It was found that using a shorter channel length and an EOF voltage in the range of 400–600 V allows application of a heat flux in the order of 10⁴ W/m², applicable to spot cooling. For elevated voltages, the velocity due to EOF increased, leading to an increase in total heat transfer for a fixed duration of time; however, the joule heating also got elevated with increase in voltage.     

Solar electric powered reverse osmosis water desalination system for the rural village,Al Maleh: design and simulation

Desalination of brackish water by using reverse osmosis (RO) system powered by solar PV has not been tried and examined in Palestine until now. This paper proposes rural village Al Maleh for erection and testing of the first PV-powered RO system. Al Maleh is highly qualified for testing of such systems since it has a lot of mineral hot water springs of about 3400?ppm salinity. Based on the climate conditions in Al Maleh, the paper presents the design of the PV-powered RO water desalination system. The obtained design results can be used for an economic feasibility study of this technology [Mahmoud, M. Techno-economic feasibility of PV-powered water desalination in Palestine. Special Case: Al Maleh Village (to be published).]. The performance of the designed system is investigated by software simulation. The obtained results show that a daily production of 1?m³ from the brackish water in Al Maleh would require about 820 peak watt of PV generator.     

Enhancing Value Engineering Process by Incorporating Inventive Problem-Solving Techniques

The creativity phase is critical to the success of a value engineering exercise, in which the brainstorming technique is deployed to generate ideas. One shortcoming of the brainstorming technique is its lack of direction in problem solving, and consequently the efficiency is low in generating innovative and useful ideas. To overcome this shortcoming, this paper has explored the possibility of incorporating the theory of inventive problem solving (TRIZ) into the workshop session of the value engineering exercise by initiating three new procedures in this session: (1) an initial design procedure to examine the functions of a proposed project; (2) a function trimming procedure to fully utilize existing resources and ensure low life-cycle cost and sustainability of the proposed project; and (3) an interaction analysis procedure to assess the proposed project in a broad perspective with social, economic, and environmental awareness. A case study has indicated the workability of the modified workshop procedures and the usefulness of TRIZ tools and techniques in efficiently and effectively creating innovative ideas.     

Experimental study on the compressive resistance of stress-relieved solid round steel members

The Canadian Standard for Antenna Towers and Antenna Supporting Structures, CSA-S37-01, specifies expressions for the compressive resistance of solid rounds based on the Structural Stability Research Council (SSRC) Column Curves for non-solid-round members and the results from experimental investigations on the compressive resistance of solid rounds carried out back to 1965. Similar Standard in USA (TIA/EIA-222-G.0) specifies design criteria for such members as derived from the superseded AISC-LRFD-94 Standard, which is independent of the shape of the member cross-section. The European Standard, Eurocode 3, provides column curves for the compressive resistance of various structural steel members, and assumes the applicability of one of them to solid rounds. As such, it is necessary to conduct an experimental study on solid round stress-relieved steel members to refine the available design equations for such members. This paper provides a summary of the literature review on solid rounds as well as a recent test program conducted on stress-relieved steel solid rounds. Correlation between the results from these tests and the current practice for the design of solid rounds is investigated. The paper concludes with a proposed compressive resistance equation for economical design of such members.     

Parenting and psychological adjustment of adolescent immigrants in Israel.

Parental and familial factors and their association with adolescents’ mental health were examined among former Soviet Union (FSU) immigrants and nonimmigrants in Israel. Questionnaires regarding parental control, inconsistency, and rejection, in addition to adolescent–family connectedness and psychological disorders, were administered to 83 FSU immigrants and 106 nonimmigrant adolescents. According to the results, FSU adolescents are less connected to their families, experience their parents as less warm and more inconsistent in their childrearing behavior, report that their mothers subject them to a higher level of control, and the psychological disorders among them are more widespread than among nonimmigrant adolescents. Maternal control, maternal temporal inconsistency, and maternal and paternal rejection were associated with psychological disorders only among nonimmigrant adolescents. No such association was found among FSU adolescents, suggesting that FSU mental health problems are associated with immigration and cultural and social factors, rather than parental and familial factors. A comprehensive intervention program is required to provide support and assistance to help immigrants overcome their psychological distresses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

I-Media: An integrated Media server and Media database as a basic component of a cross Media publishing system

The publication of the same information on different media, the so-called Cross Media Publishing (CMP), is becoming one of the central aspects in today's publishing industry. CMP centers on a media independent document definition and an efficient integrated publishing on different media: e.g. as a paper document, as an online document in the World Wide Web, and as an offline (CD-ROM based) multimedia presentation. The aim of CMP is to get these different media at the same stage, while—and that is important—spending an acceptable amount of additional effort (in time and money) for production. In this paper we present a solution for a key problem of Cross Media Publishing, the handling of media data (images, audio, video, etc.) by using a combined approach of server and database systems functionality. The integrated multimedia server and database i-Media and its role in a complete CMP solution will be presented.