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Reference Case (reference + case)
Selected AbstractsAlgorithm for determining optimum sequestration depth of CO2 trapped by residual gas and solubility trapping mechanisms in a deep saline formationGEOFLUIDS (ELECTRONIC), Issue 4 2008C. K. LIN Abstract An algorithm is proposed here for determining the optimum sequestration depth (in terms of depth corresponding to maximum net income per unit rock volume) in a saline formation for CO2 trapped by residual gas and solubility trapping mechanisms. The Peng,Robinson equation of state was used to determine the density and fugacity of sequestered CO2 and the compression energy required for CO2 injection. Geochemist's Workbench®, a commercial geochemical software package, was used to estimate CO2 solubility in groundwater. Operational costs and CO2 emissions due to compression energy consumption were estimated. A hypothetical reference case was constructed to illustrate the proposed algorithm, assuming constant values of geothermal gradient, hydrostatic pressure gradient, sweep efficiency and initial groundwater chemistry, with a depth-dependent porosity and porosity-dependent saturation of residual gas. In general, the algorithm was illustrated successfully for the hypothetical reference case and produced the following results. The depth corresponding to maximum trapping capacity was approximately 3000 m, but the depth representing maximum net income was approximately 1300 m. CO2 emissions due to compression energy consumption per unit mass of CO2 sequestration cannot be ignored, but may be <0.15, even down to a depth of 7000 m. Both the trapping capacity and net income of CO2 sequestration decreased with geothermal gradient, but the corresponding optimum depths increased with geothermal gradient. [source] Development of an optimization model for energy systems planning in the Region of WaterlooINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 11 2008Y. P. Cai Abstract In this study, a large-scale dynamic optimization model (University of Regina Energy Model, UREM) has been developed for supporting long-term energy systems planning in the Region of Waterloo. The model can describe energy management systems as networks of a series of energy flows, transferring extracted/imported energy resources to end users through a variety of conversion and transmission technologies over a number of periods. It can successfully incorporate optimization models, scenario development and policy analysis within a general framework. Complexities in energy management systems can be systematically reflected; thus, the applicability of the modeling process can be highly enhanced. Four scenarios (including a reference case) are considered based on different energy management policies and sustainable development strategies for in-depth analysis of interactions existing among energy, socio-economy and environment in the Region. Useful solutions for the planning of energy management systems have been generated, reflecting trade-offs among energy-related, environmental and economic considerations. They are helpful for supporting (a) adjustment or justification of the existing allocation patterns of energy resources and services, (b) allocations of renewable energy resources, (c) formulation of local policies regarding energy consumption, economic development and energy structure, and (d) analysis of interactions among economic cost, system efficiency, emission mitigation and energy-supply security. Results also indicate that UREM can help tackle dynamic and interactive characteristics of the energy management system in the Region of Waterloo and can address issues concerning cost-effective allocation of energy resources and services. Thus, it can be used by decision makers as an effective technique in examining and visualizing impacts of energy and environmental policies, regional/community development strategies and emission reduction measures within an integrated and dynamic framework. Copyright © 2008 John Wiley & Sons, Ltd. [source] Active measurements of a mimo WiMAX-OFDM based system in reverberation chambersMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 10 2010Adil Belhouji Abstract Electromagnetic reverberation chambers can be used for multiple-input multiple-output (MIMO) systems testing.Currently, the tests focus on parameters such as correlation, diversity gain, efficiency, etc., by using a vector network analyzer. In contrast with these passive tests, a novel way of MIMO systems characterization is described in this article. It consists on evaluating bit error rate (BER) levels of a MIMO WiMAX-OFDM system according to the Signal-to-Noise Ratio (SNR) by establishing an active link between the transmitter and the receiver. The measurement process is set up in a reverberation chamber, where multipath frequency selective channels are emulated. The obtained results are compared to a reference case with single-input single-output (SISO) to evaluate the real improvements made by the studied system. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2347,2352, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25465 [source] Oil demand in North America: 1980-2020OPEC ENERGY REVIEW, Issue 4 2001Salman Saif Ghouri This paper first analyses price and income elasticity of oil demand in the United States, Canada and Mexico for the period 1980-99. Economic activity is the main driving force that influences oil consumption in each country. Changes in oil consumption generally lagged by a few years before the full impact of changes in oil prices was realized. Consumers in the short run are constrained by technological and other barriers and, therefore, less sensitive to changes in oil prices; however, they are more responsive in the long run , though response is still inelastic. The use of advanced technology facilitated these countries to use less oil over time. The paper then looks at demand over the next 20 years. The best-fitting model predicts that, by the end of 2020 (reference case), the USA, Canada and Mexico will respectively consume 24,900, 2,596 and 2,321 thousand barrels daily, compared with 19,519, 1,943 and 1,970 thousand b/d in 1999. The model forecasts economic slowdown during 2000/2002. The USA and Canada are expected to recover quickly, while Mexico will take longer. [source] Toward a Consensus Model of the hERG Potassium ChannelCHEMMEDCHEM, Issue 3 2010Anna Stary Dr. Abstract Malfunction of hERG potassium channels, due to inherited mutations or inhibition by drugs, can cause long QT syndrome, which can lead to life-threatening arrhythmias. A three-dimensional structure of hERG is a prerequisite to understand the molecular basis of hERG malfunction. To achieve a consensus model, we carried out an extensive analysis of hERG models based on various alignments of helix,S5. We analyzed seven models using a combination of conventional geometry/packing/normality validation methods as well as molecular dynamics simulations and molecular docking. A synthetic test set with the X-ray crystal structure of Kv1.2 with artificially shifted S5 sequences modeled into the structure served as a reference case. We docked the known hERG inhibitors (+)-cisapride, (S)-terfenadine, and MK-499 into the hERG models and simulation snapshots. None of the single analyses unambiguously identified a preferred model, but the combination of all three revealed that there is only one model that fulfils all quality criteria. This model is confirmed by a recent mutation scanning experiment (P. Ju, G. Pages, R.,P. Riek, P.,C. Chen, A.,M. Torres, P.,S. Bansal, S. Kuyucak, P.,W. Kuchel, J.,I. Vandenberg, J. Biol. Chem. 2009, 284, 1000,1008).1We expect the modeled structure to be useful as a basis both for computational studies of channel function and kinetics as well as the design of experiments. [source] A mode II weight function for subsurface cracks in a two-dimensional half-spaceFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 10 2002A. MAZZŮ ABSTRACT The general properties of a mode II Weight Function for a subsurface crack in a two-dimensional half-space are discussed. A general form for the WF is proposed, and its analytical expression is deduced from the asymptotic properties of the displacements field near the crack tips and from some reference cases obtained by finite elements models. Although the WF has general validity, the main interest is on its application to the study of rolling contact fatigue: its properties are explored for a crack depth range within which the most common failure phenomena in rolling contact are experimentally observed, and for a crack length range within the field of short cracks. The accuracy is estimated by comparison with several results obtained by FEM models, and its validity in the crack depth range explored is shown. [source] Assessment of a protocol for prophylactic antibiotics to prevent perioperative infection in urological surgery: A preliminary studyINTERNATIONAL JOURNAL OF UROLOGY, Issue 6 2004SOJUN KANAMARU Abstract Background: The aim of the present study was to assess the usability and efficacy of our new protocol of prophylactic antibiotic use to prevent perioperative infection in urological surgery. Methods: We prospectively investigated 339 cases of typical urological surgery in our department between April 2001 and March 2002 (group I). We classified surgical procedures into four categories by invasiveness and contamination levels: category A, clean less invasive or endoscopic surgery; category B, clean invasive or clean contaminated surgery; category C, urinary tract diversion using the intestine; and category D, infected surgery. Antibiotics were administrated intravenously according to our protocol: category A, first or second generation cephems or penicillins during the operative day only; category B, first and second generation cephems or penicillins for 3 days; and category C, second or third generation cephems for 4 days. Category D was excluded from the analysis. To judge perioperative infections, the wound condition and general conditions were evaluated in terms of the surgical site infection (SSI) as well as remote infection (RI) up to postoperative day (POD) 14. We retrospectively reviewed 308 patients who underwent urological surgery between April 2000 and March 2001 (group II) as reference cases that were administered antibiotics without any restriction. Results: Perioperative infection rates (SSI + RI) in group I and group II were 25 of 339 (7.4%) and 35 of 308 (11.4%), respectively. Surgical site infection rates of categories A, B, and C in group I were 1.8%, 7.6%, and 30.0%, respectively, while those in group II were 2.0%, 7.4%, and 46.2%, respectively. There was no significant difference in infection rates in terms of RI and SSI between group I and group II. The amounts, as well as the prices, for intravenously administrated antibiotics and oral antibiotics decreased to approximately half and one-fifth, respectively. Conclusion: Our protocol effectively decreased the amount of antibiotics used without increasing perioperative infection rates. Thus, our protocol of prophylactic antibiotic therapy would be recommended as an appropriate method for preventing perioperative infection in urological surgery. [source] Modeling of Polymerization Kinetics and Molecular Weight Development in the Microwave-Activated Nitroxide-Mediated Radical Polymerization of StyreneMACROMOLECULAR REACTION ENGINEERING, Issue 2-3 2009Jorge J. Hernández-Meza Abstract Calculations of the polymerization rate and molecular weight development in the nitroxide-mediated radical polymerization (NMRP) of styrene (STY), using hydroxyl-TEMPO and dibenzoyl peroxide (BPO), and activated by microwave irradiation (MI), are presented. The calculations are based on a kinetic model developed in our group. Microwave activation is modeled by three approaches: microwave-activated production of free radicals from monomer molecules, microwave-enhanced thermal initiation, and microwave-enhanced dormant polymer activation. The results obtained are compared against experimental data from the literature. The first approach is the most adequate. The NMRP of STY using TEMPO, BPO, and conductive heating, and the NMRP of STY activated by MI, without initiator, are also analyzed as reference cases. [source] Identification of a small supernumerary marker chromosome, r(2)(p10q11.2), and the problem of determining prognosisPRENATAL DIAGNOSIS, Issue 10 2001N. Villa Abstract The identification of small supernumerary marker chromosomes (SMCs) and the elucidation of their clinical significance remain two of the problems in classical human cytogenetics. We observed a small supernumerary ring in amniotic fluid cell cultures and identified its origin as r(2)(p10q11.2) and its extent by means of fluorescent in situ hybridisation (FISH). Uniparental disomy (UPD) was excluded by microsatellite analysis using polymorphic markers localised in the same region. On the basis of normal ultrasonographic checks, the patient decided to continue the pregnancy. A normal female was delivered at term and subsequent neonatal follow-ups confirmed the normal phenotype and development. In the present case, genetic counselling was not helpful because of the absence of reference cases. Detailed characterisation made it possible to correlate the normal baby phenotype with the trisomic 2p10-2q11.2 genomic region. Further molecular cytogenetic investigations of SMCs classified by DNA content and pregnancy outcome data should improve genetic counselling and risk evaluation. Copyright © 2001 John Wiley & Sons, Ltd. [source] | |||||||||||||