899 research outputs found
Energy Efficient Service Delivery in Clouds in Compliance with the Kyoto Protocol
Cloud computing is revolutionizing the ICT landscape by providing scalable
and efficient computing resources on demand. The ICT industry - especially data
centers, are responsible for considerable amounts of CO2 emissions and will
very soon be faced with legislative restrictions, such as the Kyoto protocol,
defining caps at different organizational levels (country, industry branch
etc.) A lot has been done around energy efficient data centers, yet there is
very little work done in defining flexible models considering CO2. In this
paper we present a first attempt of modeling data centers in compliance with
the Kyoto protocol. We discuss a novel approach for trading credits for
emission reductions across data centers to comply with their constraints. CO2
caps can be integrated with Service Level Agreements and juxtaposed to other
computing commodities (e.g. computational power, storage), setting a foundation
for implementing next-generation schedulers and pricing models that support
Kyoto-compliant CO2 trading schemes
Nonlinear Dynamics of Energy Harvester Based on Flow Induced Vibration
AbstractIn this present work, a vertical cantilever piezoelectric energy harvester is proposed that exploits wind energy for vibration. The vertical cantilever is attached with a torsional spring at the base and a tip mass. A square bluff body is attached at the end of the cantilever so that the wind energy could be exploited effectively. The governing nonlinear electromechanical equations of motion for the system are developed using Lagrange principle and were discretized to the temporal form by using generalized Galerkin's method. The equations are solved using method of multiple scales and also using numerical methods. The responses of the system are determined for different wind speeds and load resistances. Time response and phase portraits are plotted to study the system response and influence of different system parameters on voltage generation
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Analysis of Initial Flow Data from MG-T/DOE Amoco Fee No. 1 Well
Analysis of buildup data from the Initial Flow Test indicates that the MG-T/DOE Amoco Fee No. 1 Well penetrates a zone of relatively high permeability (approx. 150 md); this high permeability zone, however, extends to a radius of only about 200 ft from the wellbore. The far field permeability (i.e., for r > 200 ft) appears to be rather low (approx. 11 md). No reservoir boundaries can be identified from the Initial Flow Test. Tthe reservoir simulator MUSHRM together with the formation parameters inferred from the buildup data were employed to history match the observed drawdown/buildup pressures and flow data. The calculated buildup pressures closely agree with the measured values; the rather poor agreement between the measured and calculated drawdown pressures is ascribed to the uncertainties in the flow rate data
Prevalence of Mental Distress and Addiction Habits among Medical Undergraduates
Introduction: Medical education across the globe is perceived as being inherently stressful leading to mental distress in medical undergraduates. Among all psychological problems, stress is one of the common problems faced by medical students. Stress is a situation that leads to tension, pressure or negative emotions such as anxiety, depression and anger. Exposure to chronic stress can lead to both physical and mental illnesses. The stressors among medical students are academic, social, personal and financial. Psychological distress among students reduces their self-esteem, quality of life and academic performance. They may engage in potentially harmful methods of coping with stress such as tobacco, alcohol and substance abuse. Objective: The present study was conducted to determine the prevalence of stressrelated problems among medical undergraduates using DASS 21 scale and also to find prevalence of addiction habits in relation to stress. Methods: It was a cross-sectional study done among medical undergraduate students. Prevalence of psychological mood disorders was assessed by using DASS-21. A pretested and predesigned questionnaire was also prepared assessing correlation of mental distress with sociodemographic characteristics and addiction habits among medical undergraduates. Results: Prevalence of depression, anxiety and stress was found to be very high among medical undergraduates with prevalence being more in females as compared to males. Hostellers were found to have more mental distress as compared to day scholars. As compared to females, males were more engaged in addiction habits mostly consumption of alcohol. Conclusion: Family support, counselling lessons and various other methods of stress management should be given to the medical students to decrease the stress level and make them aware of healthy ways of living
Predictive Modelling and Surface Analysis for Optimization of Production of Biofuel as A Renewable Energy Resource:Proposition of Artificial Neural Network Search
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A Study of Production/Injection Data from Slim Holes and Production Wells at the Oguni Geothermal Field, Japan
Production and injection data from slim holes and large-diameter wells at the Oguni Geothermal Field, Japan, were examined in an effort to establish relationships (1) between productivity of large-diameter wells and slim holes, (2) between injectivity and productivity indices and (3) between productivity index and borehole diameter. The production data from Oguni boreholes imply that the mass production from large-diameter wells may be estimated based on data from slim holes. Test data from both large- and small-diameter boreholes indicate that to first order the productivity and the injectivity indices are equal. Somewhat surprisingly, the productivity index was found to be a strong function of borehole diameter; the cause for this phenomenon is not understood at this time
STUDIES ON CONTINUOUS GRINDING PROCESS FOR DRIED WATER CHESTNUT KERNEL
Grinding is a unit operation to break big solid material into smaller pieces. As far as process of grinding is concerned, power consumption, specific energy consumption and particle size distribution and mill capacity are main considerations from engineering point of view. The experiments were conducted to study the effect of speed of mill, sieve size, feed rate and time of grinding on power consumption and average particle diameter of water chestnut in continuous grinding process. Power consumption was measured for a constant feed rate of 1 and 2 kg/h at different speed of the mill varied from 800 to 1200 rpm for the sieve openings of 0.5 mm, 1.0 mm and 2.0 mm. For all the sieve sizes and feed rates, it was observed that as the speed of the mill increases, there is an increase in power consumption and found significantly low for higher sieve size and lower feed rate. The size distribution of the water chestnut kernel for different speeds and sieve sizes at constant feed rate were obtained by sieve analysis. The milling speed has no significant effect on particle size distribution of ground product and mass fraction was minimum at lower feed rate and higher sieve size. Harris model was found best suitable to describe the size distribution in continuous grinding process. Fineness modulus decreases with increase of milling speed for experimental sieve size and feed rate
Cloudbus Toolkit for Market-Oriented Cloud Computing
This keynote paper: (1) presents the 21st century vision of computing and
identifies various IT paradigms promising to deliver computing as a utility;
(2) defines the architecture for creating market-oriented Clouds and computing
atmosphere by leveraging technologies such as virtual machines; (3) provides
thoughts on market-based resource management strategies that encompass both
customer-driven service management and computational risk management to sustain
SLA-oriented resource allocation; (4) presents the work carried out as part of
our new Cloud Computing initiative, called Cloudbus: (i) Aneka, a Platform as a
Service software system containing SDK (Software Development Kit) for
construction of Cloud applications and deployment on private or public Clouds,
in addition to supporting market-oriented resource management; (ii)
internetworking of Clouds for dynamic creation of federated computing
environments for scaling of elastic applications; (iii) creation of 3rd party
Cloud brokering services for building content delivery networks and e-Science
applications and their deployment on capabilities of IaaS providers such as
Amazon along with Grid mashups; (iv) CloudSim supporting modelling and
simulation of Clouds for performance studies; (v) Energy Efficient Resource
Allocation Mechanisms and Techniques for creation and management of Green
Clouds; and (vi) pathways for future research.Comment: 21 pages, 6 figures, 2 tables, Conference pape
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A Study of Production/Injection Data from Slim Holes and Large-Diameter Wells at the Takigami Geothermal Field, Kyushu, Japan
Production and injection data from nine slim holes and sixteen large-diameter wells at the Takigami Geothermal Field, Kyushu, Japan were analyzed in order to establish relationships (1) between injectivity and productivity indices, (2) between productivity/injectivity index and borehole diameter, and (3) between discharge capacity of slim holes and large-diameter wells. Results are compared with those from the Oguni and Sumikawa fields. A numerical simulator (WELBOR) was used to model the available discharge rate from Takigami boreholes. The results of numerical modeling indicate that the flow rate of large-diameter geothermal production wells with liquid feedzones can be predicted using data from slim holes. These results also indicate the importance of proper well design
Prognostic importance of exercise brain natriuretic peptide in asymptomatic chronic organic mitral regurgitation
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