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Abstract A novel multi-scale domain overlapping coupling methodology designed to couple a computational fluid dynamics (CFD) code with a system thermal hydraulic (STH) code was developed and its performance was investigated. The methodology has been implemented in the coupling infrastructure code Janus, developed at the University of Michigan, providing methods for the on-the-fly data transfer through memory between the commercial CFD code STAR-CCM+ and the US NRC best-estimate thermal hydraulic system code TRACE. Coupling between these two software packages is motivated by the desire to extend the range of applicability of TRACE to scenarios in which local momentum and energy transfer are important, such as three-dimensional mixing of localized slugs of deborated or cold water in the downcomer and lower plenum of a reactor pressure vessel. The intra-fluid shear forces necessary to correctly capture these effects are neglected in the TRACE equations of motion, but are readily calculated from CFD solutions. CFD/STH coupling implementations therefore have applications in reactor transients such as boron dilution scenarios, Anticipated Transient Without SCRAM (ATWS) and Main Steam Line Break (MSLB). The proposed method is based on aliasing all spatial sources and sinks of momentum in the CFD domain as frictional losses in the system code domain. The internal velocity fields and, consequently, the inertial component of the pressure field are maintained consistent between the CFD and STH domains through a complementary velocity-matching interface. In this paper, coupled simulations are performed on Cartesian and cylindrical geometry with emphasis on consistency, convergence, and stability during transient scenarios. Results show that the presented domain overlapping coupling method is capable of adjusting pressure and velocity profiles of multi-dimensional system code solutions to match CFD solutions accurately. Important characteristics of transient simulations were found to include the background flow rate, specifically the stabilizing effect of viscous forces, as well as the time derivative of the flow rate. Under certain adverse conditions, the basic coupling method is found to produce unstable behavior. A stabilization method for adjusting CFD data is laid out and found to significantly improve the method’s performance under the most challenging conditions. Recommendations are laid out for further improving the coupling via advanced time stepping methods.

New zinc phthalocyanine (ZnPc-TDA), peripherally functionalized with donor-acceptor conjugates was synthesized, and its optical, thermal, electrochemical, and photovoltaic properties were studied. The black ZnPc-TDA exhibited both excellent solubility in common organic solvents, and broad absorption covering the range 300-900 nm. The photovoltaic devices with the configuration of ITO/PEDOT-PSS/ZnPc-TDA:PCBM/LiF/Al produced short circuit current densities of 2.26 mA/cm(2), the open circuit voltage of 0.68 V and power conversion efficiency of 0.4% under AM1.5G illumination. (C) 2010 Elsevier B.V. All rights reserved.

Abstract We demonstrate the importance of stock turnover on industrial energy efficiency through a literature review and a case study of energy-intensive equipment, i.e. the electric arc furnace in the US steel industry. We describe the common methods for assessing stock turnover. We have found that both stock turnover and retrofit are important elements to explain the energy efficiency improvement rates. We investigated the development of electricity use in electric arc furnaces in the United States by tracking the development of individual furnaces over the period 1990–2002. This provides a detailed picture of changes in the stock or fleet of furnaces through turnover and/or retrofit. Our results confirm the results of other empirical studies that there is no clear lifetime of equipment. However, retired furnaces are distinctly less efficient than furnaces remaining in the stock, while new furnaces are distinctly more efficient than the average stock. We found an annual average improvement in specific electricity consumption of 1.3%/year over the studied period, of which 0.7%/year was due to stock turnover and 0.5%/year due to retrofit of stock in service throughout the period.

From its inception, the Nuclear Energy Agency (NEA), which is part of the broader Organisation for Economic Co-operation and Development, has contributed to the development of international radiological protection norms and standards. This continues today, in the form of studies and workshops to assist radiological protection policy makers, regulators and practitioners to develop concepts and approaches to help the international system of radiological protection, as recommended by the International Commission on Radiological Protection (ICRP), to evolve to better serve societal needs. The NEA's Committee on Radiation Protection and Public Health (CRPPH), in providing this support, has collaborated closely with the ICRP and strongly supports the current ICRP recommendation development process. In particular, active dialogue with a broad range of stakeholders is contributing to the evolution of concepts towards consensus on new ICRP recommendations. The CRPPH, as a body of ICRP recommendation practitioners, feels that the public, workers and the environment are well protected by the current radiological protection system, but agrees that a new consolidation and clarification of ICRP recommendations would be of value. The intent of the CRPPH in collaborating with ICRP is to develop a system of radiological protection that is simplified, more coherent, firmly based upon science and more clearly presented than the current system. This paper summarises the more detailed views of the CRPPH on the evolution of the system of radiological protection.

Abstract Electricity markets, for the purpose of dispatch, approximate non-linear generator dynamics by a constant ramp rate R MW/10 min. The scalar R enables generator serving entity (GSE) to submit convex energy bids. Given the high penetration of renewable energy resources in US utilities, particularly California and Mid-West Independent System Operators (ISO), hard-to-predict wind ramps within the operating hour necessitate frequent ramping of generators, also known as load-following. A generator’s non-linear energy conversion dynamics varies widely over the operating hour. Consequently, the assumption of a constant rate R is often violated under fast changing operating conditions. In this paper, we propose a smart local automation on a non-linear energy conversion model of a coal-fired steam turbine. The proposed controller enables an improved and a near-linear dynamic response, ensuring fulfillment of convex bids.

To meet the increasing challenges on global warming and customer demands, the current hierarchical structure of electric power grid is undergoing a rapid change by focusing on high efficiency, reliability and flexibility. To address such challenges, the new concept of smart grid with a sophisticated communication infrastructure has emerged. While power grid systems are based on traditional information architectures at present, the evolving smart grid has a strong need on communication connections among a huge amount of distributed elements, such as generators, substations, monitoring sensors and customers. However, the power industry is facing dilemma that communication resources are limited due to the lack of wireless spectrum resources and the restrictions of wired applications. This paper firstly provides the architecture of the wide-area monitoring system for smart grid by applying a spectrum sensing and sharing technique of cognitive radio, based on an overview of the current communication technologies. Afterwards, the paper presents the feasible application of cognitive communication architecture on the existing power quality monitoring system by combining long-term and short-term monitoring approaches.

Abstract Many energy-related investments are made without a clear financial understanding of their values, risks, and volatilities. In the face of this uncertainty, the investor—such as a building owner or an energy service company—will often choose to implement only the most certain and thus limited energy-efficiency measures. Conversely, commodities traders and other sophisticated investors accustomed to evaluating investments on a value, risk, and volatility basis often overlook energy-efficiency investments because risk and volatility information are not provided. Fortunately, energy-efficiency investments easily lend themselves to such analysis using tools similar to those applied to supply side risk management. Accurate and robust analysis demands a high level of understanding of the physical aspects of energy-efficiency, which enables the translation of physical performance data into the language of investment. With a risk management analysis framework in place, the two groups—energy-efficiency experts and investment decision-makers—can exchange the information they need to expand investment in demand-side energy projects. In this article, we first present the case for financial risk analysis in energy efficiency in the buildings sector. We then describe techniques and examples of how to identify, quantify, and manage risk. Finally, we describe emerging market-based opportunities in risk management for energy efficiency.

Abstract Commercial potential in developing countries has always received a great attention from international investors, but this is not the case in Waste-to-Energy sector. Waste-to-Energy is bound up with various uncertainties rooted in its long-term nature therefore incorporating risks regarding political matters in developing countries makes it more complex. The present study substantiates the incompatibility of classic valuation methods in risky projects. Consequently, to deal with the riskiness of Waste-to-Energy investment in less developed countries, the combination of binomial tree analysis and Decoupled NPV is proposed. The hybrid approach is deployed to value a Waste-to-Energy project in Iran, and all evidence attest to the robustness of the method. The contribution of this paper can open up new vistas for investing in Waste-to-Energy industry, thus abating the catastrophic effects of landfill gas emissions.

Abstract Economically harvesting energy from a microbial fuel cell (MFC), increasing its electrical power production, and developing its role as a practical energy supply, needs a low-cost and high-performance design of the MFC compartments. According to this strategy, a novel monolithic membrane electrode assembly (MEA) was fabricated and evaluated as an air–cathode in a single-chamber MFC (SCMFC). The MEA was made of bacterial cellulose (BC), conductive multi-walled carbon nanotubes (CNT), and nano-zycosil (NZ). BC, as a nano-celluloses with oxygen barrier property, can maintain anaerobic conditions for the anode compartment. Binder-less CNT coating on BC avoids costly binders such as poly-tetra fluoro ethylene (PTFE) and Nafion and decreases the MEA charge transfer resistance. NZ, as a very cheap modifier, not only prevents the anolyte leakage but also provides more MEA’s active sites for the oxygen reduction reaction (ORR). The electrochemical performance of the MEA was compared to a PTFE- based gas diffusion electrode (GDE) in the SCMFC. The MEA cell provided a pulse power density of 1790 mW/m2, roughly twice as high as the pulse power density of GDE (920 mW/m2). SCMFC’s internal resistance decreased from 1.84 KΩ (with GDE) to 0.8 KΩ (with MEA). Also, the cell’s columbic efficiency increased from 4.2% (with GDE) to11.7% (with MEA). Additionally, the capacitance of the MEA (65 mF) was much higher than the value for GDE (0.73 mF). Thus, the MEA compared to the GDE showed higher performance in the SCMFC for electricity generation and wastewater treatment at a lower cost.