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Battery algorithm verification and development using hardware-in-the-loop testingJournal of Power Sources, Volume 195, Issue 9, 1 May 2010, Pages 2969-2974Yongsheng He, Wei Liu, Brain J. KochShow preview| Related articles|Related reference work articles Purchase$ 41.95313Modelling and simulation of a pumping system fed by photovoltaic generator within the Matlab/Simulink programming environmentOriginal Research ArticleDesalination, Volume 209, Issues 1-3, 30 April 2007, Pages 23-30M. Arrouf, S. GhabrourClose preview| Related articles|Related reference work articles AbstractAbstract | ReferencesReferences AbstractIn spite of poor efficiency of the photovoltaic systems developed up to date and the high cost of the installations of the equipment of this kind of station of solar energy conversion into electric power, this did not stop the researchers to continue to make efforts in this field in order to minimize the expenses of installation of equipment and to increase the output efficiency of the photovoltaic systems. In order to make solar energy competitive with the other forms of renewable energies, a better exploitation of its advantages especially environmental side, this will be possible only with the development of the less expensive and high output efficiency systems. The objective of this work is to bring a contribution to the study of the behaviours of the photovoltaic generators and converters used to feed a well defined load, in our case an asynchronous machine actuating a centrifugal pump, this through modelling and simulation of the various stages that constitute the overall system.Purchase$ 37.95314A novel method for preparation of macroposous lithium nickel manganese oxygen as cathode material for lithium ion batteriesOriginal Research ArticleElectrochimica Acta, In Press, Corrected Proof, Available online 18 February 2011Xiaoya Wang, Hao Hao, Jiali Liu, Tao Huang, Aishui YuClose preview| Related articles|Related reference work articles AbstractAbstract | Figures/TablesFigures/Tables | ReferencesReferences AbstractA simple one-step route using gas template method is applied to synthesize macroporous LiNi0.5Mn0.5O2 which is characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), BrunauerEmmettTelle (BET) surface area, chargedischarge tests and electrochemical impedance spectroscopy (EIS) measurements. The as-synthesized material shows pure crystalline phase of LiNi0.5Mn0.5O2, while the microstructure is comprised of macrospores ranging from 0.2 to 0.5m. The first discharge capacity is of 174mAhg1 at 0.1C rate, which is much higher than that of the material synthesized by the conventional solid state reaction method. Furthermore, the macroporous LiNi0.5Mn0.5O2 material shows remarkable rate capacity and cycle stability, which may be attributed to the shorter lithium ion diffusion distance and better electrolyte penetration.Article Outline1. Introduction2. Experimental 2.1. Preparation of LiNi0.5Mn0.5O22.2. Characterizations2.3. Electrochemical measurement3. Results and discussion 3.1. Structure characterization3.2. Morphology characterization3.3. Electrochemical characterization3.4. Lithium ion diffusion coefficient calculation4. ConclusionsAcknowledgementsReferencesPurchase$ 31.50Research highlights The intrinsic poor electronic conductivity of layered LiNi0.5Mn0.5O2 cathode material limits its wide application. In this study, pure phase, well-crystallized macroporous LiNi0.5Mn0.5O2 was prepared by a simple one-step route using gas template. The as-synthesized LiNi0.5Mn0.5O2 has much higher first discharge capacity than the material synthesized by conventional solid state reaction method. Furthermore, the macroporous LiNi0.5Mn0.5O2 material also possesses remarkable rate capacity and cycle stability.315Model-Based Cost-Effectiveness Analyses for the Treatment of Acute Stroke Events: A Review and Summary of ChallengesOriginal Research ArticleValue in Health, Volume 12, Issue 4, June 2009, Pages 507-520Stephanie R. Earnshaw, Michele Wilson, Josephine Mauskopf, Ashish V. JoshiClose preview| PDF (129 K) | Related articles|Related reference work articles AbstractAbstract | ReferencesReferences AbstractObjectiveTo summarize the methodological approaches used in published decision-analytic models evaluating interventions for acute stroke treatment, to highlight key components of decision-analytic models of stroke treatment, and to discuss challenges for developing stroke decision models. MethodsA review of the published literature was performed using Medline, to identify studies involving mathematical decision models to evaluate interventions for acute stroke treatment. Articles were analyzed to determine key components of a stroke model and to note areas in which data are lacking. ResultsWe identified 13 published models of acute stroke treatment. These models typically possessed a short-term treatment module and a long-term post-treatment module. The following aspects of economic modeling were found to be relevant for developing a stroke model: modeling approach and health state; health state transition probabilities; estimation of short-term, long-term, and indirect costs; health state utilities; poststroke mortality; time horizon; model validation; and estimation of parameter uncertainty. ConclusionsData gaps have limited the development of economic models in stroke to date. In order to more accurately assess the long-term incremental impact of a new treatment of stroke, future research is needed to address these data gaps. We recommend that the complexity of models for examining the cost-effectiveness of an acute stroke treatment be kept to a minimum such that it can incorporate the currently available data without making a large number of assumptions around the data.316Virtues of simple hydro-economic optimization: Baja California, MexicoOriginal Research ArticleJournal of Environmental Management, Volume 90, Issue 11, August 2009, Pages 3470-3478J. Medelln-Azuara, L.G. Mendoza-Espinosa, J.R. Lund, J.J. Harou, R.E. HowittClose preview| Related articles|Related reference work articles AbstractAbstract | Figures/TablesFigures/Tables | ReferencesReferences AbstractThis paper uses simple hydro-economic optimization to investigate a wide range of regional water system management options for northern Baja California, Mexico. Hydro-economic optimization models, even with parsimonious model formulations, enable investigation of promising water management portfolios for supplying water to agricultural, environmental and urban users. CALVIN, a generalized hydro-economic model, is used in a case study of Baja California. This drought-prone region faces significant challenges to supply water to agriculture and its fast growing border cities. Water management portfolios include water markets, wastewater reuse, seawater desalination and infrastructure expansions. Water markets provide the flexibility to meet future urban demands; however conveyance capacity limits their use. Wastewater reuse and conveyance expansions are economically promising. At current costs desalination is currently uneconomical for Baja California compared to other alternatives. Even simple hydro-economic models suggest ways to increase efficiency of water management in water scarce areas, and provide an economic basis for evaluating long-term water management solutions.Article Outline1. Introduction 1.1. Hydro-economic optimization of regional water resource networks1.2. Case study: Baja California Mexico2. Methods 2.1. Urban water demand2.2. Agricultural water demand model2.3. Hydrology and model calibration2.4. Water management portfolios and modeling approach3. Results and discussion 3.1. Water management portfolios3.2. Worthwhile infrastructure expansions3.3. Sensitivity analysis3.4. Model limitations4. ConclusionsAcknowledgementsReferencesPurchase$ 41.95317Statistical modeling of land-cover changes based on key socio-economic indicatorsOriginal Research ArticleEcological Economics, Volume 62, Issues 3-4, 15 May 2007, Pages 496-507Elke Hietel, Rainer Waldhardt, Annette OtteClose preview| Related articles|Related reference work articles AbstractAbstract | Figures/TablesFigures/Tables | ReferencesReferences AbstractLandscapes are complex humanenvironment systems operating at spatio-temporal scales. Time is just as important as space when researching landscape changes. These changes are influenced by both environmental and socio-economic factors. However, correlations between environmental landscape attributes and land-cover patterns/changes are weakened by human activities such as intensification of agriculture eliminating the constraints of water and nutrient availability. Relations between changes in socio-economic organisation and land cover become apparent only over a longer period of time. Thus, in our study, we focused on socio-economic factors and their long-term effects on land cover. We present a method to (i) differentiate types of land-cover changes at district level, (ii) model correlations between socio-economic factors and land cover changes and (iii) identify key socio-economic indicators of land-cover changes between 1945 and 1999 in a German marginal rural landscape. We employed agricultural land-cover data gained from the interpretation of multi-temporal aerial photographs. Based on these data, we differentiated types of land-cover changes, characterising different directions of agricultural land-cover changes in the observation time period. Various socio-economic aspects were considered by introducing data representing factors of demography, employment, economy, infrastructure, agricultural structure and policy. The relations between time series of land-cover data and of socio-economic data were modeled with the help of redundancy analysis. Correlation coefficients were used to identify key socio-economic indicators of land-cover changes. The results showed that a relatively high percentage of variance in land-cover data can be explained by socio-economic factors. The types of land-cover changes can be characterised by combinations of key socio-economic indicators. The indicators can be helpful to reconstruct land-cover changes in other regions. Thus, they provide a basis for the development of sustainable land-cover management systems.Article Outline1. Introduction2. Study area3. Methods 3.1. Data collection 3.1.1. Land-cover data3.1.2. Socio-economic data3.2. Modeling the relations between socio-economics and land cover 3.2.1. Model inputs3.2.2. Selecting significant socio-economic variables3.2.3. RDA model4. Results 4.1. Classifying types of land-cover changes 1945994.2. Significant socio-economic variables4.3. Modeling land cover in relation to socio-economic variables4.4. Identifying key socio-economic indicators of land-cover changes5. Discussion 5.1. Land-cover and socio-economic data5.2. Land-cover changes as a function of combined socio-economic indicators6. ConclusionAcknowledgementsReferencesPurchase$ 41.95318A stochastic dynamic model for optimal timing of investments in new generation capacity in restructured power systemsOriginal Research ArticleInternational Journal of Electrical Power & Energy Systems, Volume 29, Issue 2, February 2007, Pages 163-174Audun Botterud, Magnus KorpsClose preview| Related articles|Related reference work articles AbstractAbstract | Figures/TablesFigures/Tables | ReferencesReferences AbstractIn this paper we formulate the power generation investment problem for a decentralised and profit-maximising investor operating in a restructured and competitive power system. In particular, we look at how uncertainty influences the optimal timing of investments in new power generation capacity. A real options approach is used to take long-term uncertainty in load growth, and its influence on future electricity prices, into account in the investment optimisation. In order to value the operational flexibility of a new power plant we use an electricity price model, where the spot price is a function of load level and installed generation capacity, in addition to short-term uncertainties and temporal fluctuations in the market. The investors income from a capacity payment, which also can depend on the systems total capacity balance, can also be represented. Hence, with the optimisation model we can analyse power plant profitability and optimal timing of new investments under different market designs. In a case study from the Nordic electricity market we analyse the effect of uncertainty on optimal investment timing. We also examine how a fixed or variable capacity payment would influence the investment decision, and discuss the system consequences of the resulting investment strategies.Article Outline1. Introduction2. Power generation investments under uncertainty 2.1. Real options theory2.2. Existing real option models for investments in power generation plants2.3. The model concept in this paper3. A stochastic dynamic investment model 3.1. Mathematical description of the investment problem3.2. Profit from the electricity spot market3.3. Profit from capacity payments3.4. Representation of other investors3.5. Optimal investment thresholds4. Case study from the Nordic electricity market 4.1. Assumptions in case study4.2. Scenario 1: Energy only market, no investment incentive4.3. Scenario 2 and 3: Fixed and variable capacity payments4.4. System consequences4.5. Discussion5. ConclusionAcknowledgementsReferencesPurchase$ 41.95319A multivariate causality test of carbon dioxide emissions, energy consumption and economic growth in ChinaOriginal Research ArticleApplied Energy, Volume 87, Issue 11, November 2010, Pages 3533-3537Ching-Chih ChangClose preview| Related articles|Related reference work articles AbstractAbstract | Figures/TablesFigures/Tables | ReferencesReferences AbstractThis paper uses multivariate co-integration Granger causality tests to investigate the correlations between carbon dioxide emissions, energy consumption and economic growth in China. Some researchers have argued that the adoption of a reduction in carbon dioxide emissions and energy consumption as a long term policy goal will result in a closed-form relationship, to the detriment of the economy. Therefore, a perspective that can make allowances for the fact that the exclusive pursuit of economic growth will increase energy consumption and CO2 emissions is required; to the extent that such growth will have adverse effects with regard to global climate change.Article Outline1. Introduction2. Methodology3. Multivariate co-integration test 3.1. Vector error correction model4. Empirical analysis 4.1. Data analysis4.2. Unit roots4.3. Co-integration test and Vector error correction model4.4. Intensity of carbon dioxide emissions and energy consumption5. ConclusionsReferencesPurchase$ 41.95320Effect of partial replacement of sand with dry oyster shell on the long-term performance of concreteOriginal Research ArticleConstruction and Building Materials, Volume 24, Issue 5, May 2010, Pages 758-765Eun-Ik Yang, Myung-Yu Kim, Hae-Geun Park, Seong-Tae YiClose preview| Related articles|Related reference work articles AbstractAbstract | Figures/TablesFigures/Tables | ReferencesReferences AbstractTo evaluate the practical application of crushed oyster shells (OS) as construction materials, an experimental study was performed based on equal materials proportion and the partial replacement of saturated-surface-dry (SSD) sand with dry oyster shell. More specifically, the long-term mechanical properties and durability of concrete with OS partially substituted for fine aggregate were investigated. Test results indicate that long-term strength of concrete with 10% OS replacement is almost identical to that of normal concrete. However, the long-term strength of concrete with 20% OS replacement is appreciably lower than that of normal concrete. Therefore, higher OS substitution has the possibility of negatively influencing the concrete long-term strength increment. Elastic modulus of concrete with OS replacement decreases as the substitution mixture ratio increases. Specifically, the modulus is reduced by approximately 1015% when OS are used for 20% of the fine aggregate. The drying shrinkage strain increases as the substitution ratio (SR) of OS is increased. In addition, the existing model code for drying shrinkage and creep does not coincide with the test results of the present study. A prediction equation for drying shrinkage has been developed. The utilization of OS as a fine aggregate in concrete has a positive effect on freezing and thawing resistance and water permeability is also considerably improved. However, OS has no apparent effect on carbonation and chemical attack of concrete. Finally, it is noted that the strength, elastic modulus, drying shrinkage, freezing and thawing resistance, and permeability are significantly affected by increased OS substitution, particularly for long-term performance, while other properties such as creep and carbonation, as well as chemical attack test results, were not substantially affected.Article OutlineNomenclature1. Introduction2. Experimental program 2.1. Material properties2.2. Mixture proportioning and test variables2.3. Main test items and test procedure3. Test result