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Although lithium-ion batteries (LIBs) have many advantages, they cannot satisfy the demands of numerous large energy storage industries owing to their high cost, low security, and low resource richness. Aqueous zinc-ion batteries (ZIBs) with low cost, high safety, and high synergistic efficiency have attracted an increasing amount of attention and are considered a promising choice to replace LIBs. However, the existing cathode materials for ZIBs have many shortcomings, such as poor electron and zinc ion conductivity and complex energy storage mechanisms. Thus, it is crucial to identify a cathode material with a stable structure, substantial limit, and suitability for ZIBs. In this review, several typical cathode materials for ZIBs employed in recent years and their detailed energy storage mechanisms are summarized, and various methods to enhance the electrochemical properties of ZIBs are briefly introduced. Finally, the existing problems and expected development directions of ZIBs are discussed.

The electricity enterprise is one of the most vital infrastructure industries in every state, which is of tremendous importance because of capital intensity, growing efficiency, and productivity. Considering its importance, this observed and compared regional electricity businesses’ performance in Iran for the primary time by supplying a combined organizational ambidexterity model and grid records envelopment analysis. Ambidexterity is one of the newest subjects in the field of organizational and management fields, which may be described because of the company’s capacity to awareness on Exploitation (use of present capabilities) and exploration (discovery of recent competencies). in this investigation, with the help of information envelopment evaluation grid models, the inner approaches of 16 regional power corporations inside the form of two ranges of layout, improvement, and operation in 2016 were analyzed, and the ambidexterity and performance of organizations had been Calculated. The outcomes suggest that the nearby power agencies of Tehran, Semnan, and Kerman in both levels of labor have a single performance and are added as ambidextrous businesses. Also, the West regional energy business enterprise has the bottom ambidexterity rating.

III–V quantum dot systems are widely studied to implement the promising intermediate band solar cell concept. However, current performances are quite lower than theoretical expectations, and severa...

In order to increase the exploitation of the renewable energy sources, the diffusion of the distributed generation systems is grown, leading to an increase in the complexity of the electrical, thermal, cooling and fuel energy distribution networks. With the main purpose of improving the overall energy conversion efficiency and reducing the greenhouse gas emissions associated to fossil fuel based production systems, the design and the management of these complex energy grids play a key role. In this context, an in-house developed software, called COMBO, presented and validated in the Part I of this study, has been applied to a case study in order to define the optimal scheduling of each generation system connected to a complex energy network. The software is based on a non-heuristic technique which considers all the possible combination of solutions, elaborating the optimal scheduling for each energy system by minimizing an objective function based on the evaluation of the total energy production cost and energy systems environmental impact. In particular, the software COMBO is applied to a case study represented by an existing small-scale complex energy network, with the main objective of optimizing the energy production mix and the complex energy networks yearly operation depending on the energy demand of the users. The electrical, thermal and cooling needs of the users are satisfied with a centralized energy production, by means of internal combustion engines, natural gas boilers, heat pumps, compression and absorption chillers. The optimal energy systems operation evaluated by the software COMBO will be compared to a Reference Case, representative of the current energy systems set-up, in order to highlight the environmental and economic benefits achievable with the proposed strategy.

This paper concerns the difficult, somewhat circular, problem of managing complex interconnected dynamical systems. This generally must be done by avoiding complexity and the needs for fast fail-prone communications and having only a limited number of measurements. We illustrate this problem on a typical complex energy management for cooling systems. We first derive conditions for decomposition into subsystems modeled in terms of their own internal dynamics and output measurements on the interfaces with other components. We then use these decomposed models to illustrate how well distributed estimation can be done. The accuracy of parameter estimation is demonstrated using a real-world commercial cooling system.

The growing diffusion of the distributed generation systems, due to the European and national legislations which impose the fossil fuel and greenhouse gas emissions reduction and the renewable sources exploitation, have led to an increase in the complexity of the existing energy networks. The main issue of the complex energy grids is their management, which consists in the resolution and optimization of the load allocation problem by minimizing the primary energy consumption and, thus, improving the overall efficiency. In this context, the aim of this paper is to develop and validate a non-linear algorithm suitable for the resolution of the load allocation problem. In detail, the software COMBO, which has been developed by the University of Bologna, is based on a non-heuristic algorithm and allows to optimize a complex energy network — characterized by electrical, thermal, cooling and fuel fluxes — by evaluating all the possible combinations of solutions. The objective function of the software consists in the minimization of the total cost of energy production, including not only the variable costs, but also the costs related to the environmental impact of the energy systems. In this paper the mathematical model of the algorithm at the basis of the software COMBO is presented and described in detail. Furthermore, the software has been validated by its application to a case study and comparing the results with the ones obtained with a previously developed software based on a genetic algorithm (heuristic non-linear method).

This year replete with so many anniversaries related to the energy sector sees the centenary celebration of the GOELRO Plan. This event is remarkable for energy studies: a complex energy method that backed up the Plan development half a century later became one of the preconditions for the development of the methodology of systems analysis of the energy development. The groundwork of this methodology was laid at SEI/ESI SB RAS (Siberian Energy Institute. Melentiev Energy Systems Institute of the Siberian Branch of the Russian Academy of Sciences) founded by Academician L.A. Melentiev; the institute celebrates its 60th anniversary this year. Half a century ago, an 'off-site' department of the SEI was established in Moscow and 15 years later it was reorganized into ERI RAS (Energy Research Institute of the Russian Academy of Sciences) and GKNT (State Committee for Science and Technology). The paper focuses on the background of the development of the theory and methods of systems analysis of energy development, covers its main theoretical and applied contributions in two stages of social and economic development of the country, discusses evolution of this research area and its possible adoption in the alternative (mobilization-type and liberal) concepts of shaping 'the information society’ of the future.

Strongly correlated materials possess a complex energy landscape and host many interesting physical phenomena, including charge density waves (CDWs). CDWs have been observed and extensively studied in many materials since their first discovery in 1972. Yet, they present ample opportunities for discovery. Here, we report a large tunability in the optical response of a quasi-2D CDW material, 1T-TaS$_2$, upon incoherent light illumination at room temperature. We show that the observed tunability is a consequence of light-induced rearrangement of CDW stacking across the layers of 1T-TaS$_2$. Our model, based on this hypothesis, agrees reasonably well with experiments suggesting that the interdomain CDW interaction is a vital knob to control the phase of strongly correlated materials., 16 pages, 4 figures

This paper describes how the scientific contributions of Prof. Szargut and his co-workers have inspired the academic activities of the Exergy Team of the Laboratory of Environmental and Thermal Engineering (LETE) of the Polytechnic School of the University of Sao Paulo. The work of Prof. Szargut was at first used for preparing a course on Exergy Analysis, which has been taught since 1992 to MSc and Ph.D. students of the graduate program in Mechanical Engineering of the Polytechnic School of the University of Sao Paulo. Since then, the methods and concepts established by Prof. Szargut have played an important role in the development of the various research lines at LETE for the past fifteen years. Complex thermodynamic systems, such as petroleum production and refining plants, biofuel production routes, combined production of ethanol and electricity technologies, aircraft systems, environmental impact mitigation processes, CO2 capture units, ammonia production facilities, and the human body and its systems were analyzed using the concepts and tools suggested by Prof Szargut. The present article illustrates how the application of exergy analysis, thermoeconomic and environmental performance indicators, cumulative exergy consumption, definition of reference environment and chemical exergy can serve different purposes when evaluating thermodynamic systems.

Industrial processes with applications such as pasteurization, drying and distillation have heat demand at a temperature between 100–125 °C. Industries with large amounts of waste heat and cooling demand will benefit from the development of high temperature heat pumps (HTHPs) which can replace conventional heating and waste heat disposal systems. This potentially saves both investment and operational cost of a boiler and a cooling tower with a single more efficient and less complex energy system. At the same time, the environmental footprint is reduced. The working fluids for these high temperature heat pumps using the vapour compression technology are often constrained by their high compressor suction and discharge temperature as well as the safety and environmental impact of the fluids. Within these limits, this paper conducts a theoretical analysis to evaluate available and potential fluids with thermodynamic properties that are applicable for HTHPs. The evaluations show that certain hydrocarbons and halocarbons are the most promising fluid candidates for waste heat upgrade from low temperatures to high temperatures, up to 125 °C.

By employing an online social survey in a prefecture that is home to a nuclear power plant and a prefecture that consumes a large amount of energy, this paper investigates the following elements: levels of desire to understand the issues relevant to complex energy and environmental policies, their willingness to talk about such issues in a random sample at the national and prefectural levels, and the relationship between these two elements. Results found that 70–85% of respondents showed a moderate or strong willingness to learn about 14 relevant issues ranging from nuclear waste management to policy transition periods. Moreover, 35% of respondents indicated a moderate or strong willingness to participate in a national- or prefectural-level random sampling citizen dialogue on energy and environmental policy. A stronger desire to learn about the issues is directly associated with a greater willingness to participate in public discussions. The Japanese government produces and disseminates pertinent information reflecting the results of public dialogue, which shows citizens’ increasing willingness to participate in debates at the national level, particularly for those who are more inclined to pay for renewable energy. This survey shows the propensity of Japanese citizens to engage in talks on energy and environmental policy.

Environmental considerations have imposed new restrictions in the planning and management of energy systems. This research aims at describing the necessity and application of a new concept in environmental responsibility accounting. The method is based on physical quantities to overcome the weaknesses of already developed allocation approaches, and to internalize the external environmental damages using the exergy concept. The proposed method is a modification of the exergoenvironmental analysis in order to take into account the effect of non-energy streams in a macro-level energy system. In the proposed method, environmental responsibilities are to be calculated based on the exergy destruction within the system. As a case study, the method is applied to a complex energy system. It is shown that the derived environmental responsibilities are representative of the units’ role in total emissions and corresponding contributions to an integrated environmental management. Comparison of the results shows that the responsibilities are higher than the emission reduction limits for service consuming units, while they are less for service providing units. The differences between the responsibilities and permits could represent the non-internalized external damage costs.

This article shows a real ongoing project called RenoActive, which is financed by company Velux. In cooperation with the company mentioned above an old single-family house was chosen to renovate. Three energy alternatives had been calculated: Standard, Comfort and Deluxe. The thermal insulation system of the building is almost the same in all three alternatives. The alternatives mostly appear in the building services systems. This article evaluates the energy consumption and investment differences between the alternatives.

Complex energy systems can effectively integrate renewable energy sources such as wind and solar power into the information network and coordinate the operation of renewable energy sources to ensure its reliability. In the voltage source converter-based high voltage direct current system, the traditional vector control strategy faces some challenges, such as difficulty in PI parameters tuning and multiobjective optimizations. To overcome these issues, a finite control set model predictive control-based advanced control strategy is proposed. Based on the discrete mathematical model of the grid-side voltage source converter, the proposed strategy optimizes a value function with errors of current magnitudes to predict switching status of the grid-side converter. Moreover, the abilities of the system in resisting disturbances and fault recovery are enhanced by compensating delay and introducing weight coefficients. The complex energy system in which the wind power is delivered by the voltage source converter-based high voltage direct current system is modeled by Simulink and simulation results show that the proposed strategy is superior to the tradition PI control strategy under various situations, such as wind power fluctuation and fault occurrences.

Exergy analysis is a powerful thermodynamic technique for assessing the performance of complex energy systems and optimizing their efficiency. A lot of research has been performed on exergy analysis of building energy systems, but there is still a real need to evaluate the practical application of low-exergy approaches on a building scale. One of the challenges that one faces when evaluating building energy systems from an exergy point of view is a lack of a suitable approach for a meaningful comparison of buildings with different types of energy supplier. This paper proposed three approaches, namely Inner boundary of the system, Comparative exergy efficiency and Potential solar exergy efficiency for a fair exergetic comparison of renewable and non-renewable building energy systems. To demonstrate the applicability of the suggested solutions, two case studies using a renewable and a non-renewable system are considered. A solar assisted boiler system and a conventional boiler system are used as representatives of renewable and non-renewable energy systems, respectively, and analysed based on the presented approaches. The results of the analysis show that the proposed approaches are applicable and they enable an exergetic comparison between renewable and non-renewable building energy systems to be made fairly.

The development of GIS technologies and the availability of a wide range of geodatasets provide great potential for modeling physiographic objects, in particular, river systems. The adequate automatic method of river network digitizing was developed and tested using the digital elevation model based on applying the Complex Energy Index (CEI); the results are presented. The index form includes the independent parameterization of main geomorphologic and climatic factors of the first-order stream generation. The method testing proved that it is efficient and the results of its use can be reliably interpreted. The software was developed on the basis of ArcGIS tools. It implements the full algorithm of the automatic digitizing of river network using the digital elevation model. It also allows advancing studies on this issue, and could be used for solving applied problems.

Aim The aim of this paper is to determine simple inexpensive interventions to manage obesity using environmental factors and complexity theory. The work intends to explore new methods of resolving the complexity of body energy balance and thereby manage obesity. Method The complex energy balance system is examined through literature analysis to determine if common environmental factors could be effective in obesity management. The methods of action of selected factors are then analysed to determine their suitability for use in combination in an intervention for obesity. Results Vitamin C, vitamin D and secondary plant metabolites appear to be applicable in a complex systems approach to obesity management. In operation, vitamin D is a vital substance with a significant role in metabolism, plant secondary metabolites demonstrate broad energy management properties and vitamin C exhibits significant effects on plasma glucose and accordingly weight management. A virtual deficiency state can be demonstrated for each of these substances that may significantly contribute to obesity. Conclusion Due to their multiple effects, vitamin C, vitamin D and plant secondary metabolites, could form an effective intervention in a complex systems approach to obesity management for home use.

Energy hubs is an integrated system which is capable of transporting, transforming, and storing several types of energy. A number of hubs can be combined as a network and achieve higher efficiency by exchanging information and energy with each other. A decision-making framework for optimal integration of independent small-scale distributed energy systems and traditional large scale combined heating and power (CHP) plants is presented, and an energy supply system with renewable energy resources in Shanghai is cited as a case study. A performance simulation model of this energy network is proposed based on energy hub concept and energy flow between its elements. Furthermore, a novel optimization method named Whales optimization algorithm (WOA) is presented for 24 h operational optimization. A case study is undertaken on a seven-node energy system, including four energy hubs and three load hubs. The results of the case study show that the proposed model and optimization method can improve energy utilization efficiency and reduce system operating costs, even under a system contingency condition.

When complex energy systems are analyzed and when a large number of their components is observed, the destruction of exergy related to a single component is dependent on its own properties, but also on the characteristics of other components. The advanced exergy analysis is useful for providing supplementary information on the interaction between the components. It also exposes the real improvement potential related to each component of a system, but also of a system as a whole. In this paper, an existing complex industrial plant with 33 components and 70 streams is analyzed using the first and second level of exergy destruction splitting for the boiler, as a main plant component from the aspect of destroying the useful work. From the total unavoidable exergy destruction 97.28% comes from the internal irreversibility, 2.72% comes from the irreversibilities of other components, while 95.26% of the unavoidable exergy destruction (186.49 kW) comes from the internal irreversibility, and 4.74% from the external irreversibility. The final result of the advanced exergy analysis for the steam generator is the total value of the avoidable exergy destruction as a real potential that can be avoided. It is 16.19% of the total exergy destruction of the component. That is less than the data obtained in the first decomposition level (186.49 kW) merely due to the existence of mexogenous exergy destruction.

In the context of modern integrated energy supply systems of Ukraine, it is advisable to perform an analysis of the features of their operation, which provide integration of self-organizing electricity and heat supply systems, taking into account available sources of dispersed generation. The possibility of using a model of power hubs that combine heterogeneous sources of thermal and electric energy generation is considered. Simulation of energy consumption and energy supply for a residential complex was performed. The obtained results of optimal energy consumption planning testify to the effectiveness of the proposed approach and point the ways to optimize the structure of integrated energy supply systems operating in the conditions of the energy market of Ukraine.

Many smartphone applications suffer from energy inefficiency problems, but locating these problems is quite difficult and labor-intensive. Automated tools for detecting energy inefficiency bugs have been shown to be effective. Existing approaches generally consist of two parts, namely the simulation part and the monitor part. The simulation part explores an application's state space guided by an application execution model, and the monitor part checks for occurrences of energy inefficiency patterns. However, existing approaches might miss energy inefficiency bugs due to their imprecise application execution models and oversimplified energy inefficiency diagnosis policies. In this paper, we proposed NavyDroid, an approach to diagnosing energy inefficiency problems more effectively. We summarized a comprehensive application execution model from Android specifications and expressed it as a state machine. By considering multiple patterns of wake lock misuses, our approach is able to detect more complex energy bugs caused by wake lock misuses. We implemented NavyDroidon top of Java Pathfinder (JPF) and applied it to real-world applications. We evaluated NavyDroid with 17 real-world Android applications, and NavyDroid located more energy inefficiency bugs in these applications than the existing work E-GreenDroid did. The results of our experiments demonstrate that our approach can effectively locate real energy inefficiency bugs in Android applications, suggesting its effectiveness.

The next generation of electrical distribution systems (EDSs), with increasing penetration of distributed generation resources (DERs), represent complex energy systems with multiple functionalities. One of those functionalities is to improve the resiliency through formation of a microgrid. An ideal microgrid is capable of seamless transition from grid-tied to island state of operation. However, microgrid protection is one of the challenges faced by utilities. Since each EDS may have unique characteristics, overcoming this challenge requires an accurate modeling and simulation tool. In this paper an analytical tool is presented to assist utilities protection engineers in investigating the effectiveness of microgrid protection schemes. The tool uses raw data from utilities' existing database and generate accurate model of the EDS. The model can be used as a plug-and-play platform for different types of protection analysis. Simulation results of a real case study show the accuracy and functionality of the tool.

We now live surrounded by sensors, we create information continuously and we leave constantly computer traces of our activities. The processing and analysis of this huge volume data, so called Big Data, offer innumerable and still largely unexplored: health (epidemiology, genomics complex energy networks, intelligent cities, forecasting and management of environmental risks, etc. Big Data has, and will increasingly, a very significant impact at the societal economic and commercial levels. Many interesting Big Data problems can be modeled as problems on graphs/networks.

In general, the modeling and simulation of complex energy systems is a challenging task as it requires expert knowledge in modeling as well as in the behavior of the real systems. As an example of a complex energy system, this paper considers a combined solar and heat pump (SHP) system for the efficient energy supply of buildings. The challenges in designing new models within the simulation environment TRNSYS are described. As an alternative to the complex and lengthy general modeling process, a TRNSYS-based stand-alone tool (SHP-SIMFRAME) is presented which enables users to analyze different predefined SHP concepts with hardly any knowledge in modeling and simulation itself.

A solid oxide fuel cell (SOFC) system involves phenomena that take place at different scales. The electrochemical active cell—a multicomposite structure that consists of different microscopic layers made of different materials—is thus at the center of a broader and complex energy system, whose efficient and durable performance much depends on several other integrated subsystems and auxiliaries which both provide reactants to the fuel cell and extract exhausts from the same. This is the reason energy analysis focuses on the overall plant behavior and not only on cell and stack performance. This chapter will review modeling tools and approaches for system performance evaluation.

The article discusses the problem of the transmission of reliable monitoring and control signals through communication channels of complex energy supply of industrial objects control systems. Mathematically justified mismatch concept “accuracy of information” with “protected information from the noise in the communication channel.” The principles of the combined code, providing a high level of reliability of energy management systems.

In this paper, a method based on the thermo-economics structure theories and the prospect diagnosis will apply in the 630MW power plants. To make use of thermodynamic simulation establish system of the thermo-economics produce model. The thermo-economic model and the exergy cost model for the plant based on the Fuel-Product concept have been defined to quantify the productive interaction between different devices. The paper analyses the 3VWO and 4VWO conditions and the effects of the operating parameters on the exergy cost of each component have been studied. The results showed that the Structure Theory is a powerful and effective tool, which can make up the insufficiencies of the conventional thermodynamic methods and can be used for the cost-effective operation analysis and optimization in thermal power plants and other complex energy system.

As the demonstration of eco-communities, energy planning becomes more and more important for university campus. However, insufficient energy use data accumulation has been a significant barrier against fully understanding of energy use characteristics, and demand load features of campus buildings, which usually provide the basic support for energy planning from the demand side. A methodology to reveal the features of demand load and energy use of campus building was developed for this purpose. As a case study, both the long-term and real-time data of the electricity, heating, and water usage of a Norwegian university campus were analyzed by the descriptive statistics. On this base, coincidence characteristics of energy and water usage of the entire campus were analyzed, and individual coincidental rates to the campus were also quantified accordingly. The coincidence factors were calculated to be at high levels, which implied that the campus buildings’ usage of energy was quite similar to that of water. Finally, the individual coincidental contribution to total campus energy use was analyzed by the cluster analysis, to identify those buildings with the large potential of operation optimization. The results from this study could be used for the energy planning of cities and other urban energy systems. This is the authors' manuscript to the article (preprint).

In this paper, a development of agent-based IEDs(Intelligent electronic devices) for integration control of building microgrid in smart green building are proposed. To manage and control this complex energy system of smart green buildings, multi-agent system based networks is needed. Thus, several IEDs for utilizing multi-agent system are developed and modified for the their verification of performance as agent modules functions in the integrated experimental equipment. The good performance of these IED agents are verified from experimental results obtained from seamless bi-directional communication by SOAP/XML protocol between PC agent and IED agent.

A double-blind trial in 600 patients with grade I, II, and III chronic cerebral ischemia demonstrated the high clinical efficacy of Cytoflavin, an antioxidant and energy corrector, at a dose of two tablets twice daily for 25 days, as compared with a placebo. Patients receiving Cytoflavin showed reductions in the severity of the main symptoms, improvements in balance and gait functions, decreases in the severity of both asthenic and neurotic syndromes, and improvements in cognitive functions. Cytoflavin had positive effects on sleep quality and all aspects of patient’s activities of daily living.

A common characteristic of large-scale, complex energy conversion, generation, and processing systems, such as fossil fuel/thermoelectric power plants, gas processing facilities, off-shore rigs, and high-capacity compressor and pumping stations, is that large amounts of potentially flammable, combustible, or pressurized materials are concentrated and processed in single sites under the centralized control of a few operators (working in a control-room environment). The effects of human error in these facilities are often neither observable nor reversible; therefore, error recovery is either too late or impossible. Catastrophic breakdowns of these systems, created by man-made and natural causes, pose serious threats and long-lasting health and environmental consequences for workers in the facility, for the local public, and possibly for the neighboring region and the whole country. For the foreseeable future, despite increasing levels of computerization and automation, human operators will remain i...

This report documents the results of a Laboratory Directed Research and Development (LDRD) effort enti tled "Classifier - Guided Sampling for Complex Energy System Optimization" that was conducted during FY 2014 and FY 2015. The goal of this proj ect was to develop, implement, and test major improvements to the classifier - guided sampling (CGS) algorithm. CGS is type of evolutionary algorithm for perform ing search and optimization over a set of discrete design variables in the face of one or more objective functions. E xisting evolutionary algorithms, such as genetic algorithms , may require a large number of o bjecti ve function evaluations to identify optimal or near - optimal solutions . Reducing the number of evaluations can result in significant time savings, especially if the objective function is computationally expensive. CGS reduce s the evaluation count by us ing a Bayesian network classifier to filter out non - promising candidate designs , prior to evaluation, based on their posterior probabilit ies . In this project, b oth the single - objective and multi - objective version s of the CGS are developed and tested on a set of benchm ark problems. As a domain - specific case study,more » CGS is used to design a microgrid for use in islanded mode during an extended bulk power grid outage.« less

Ultrathin endoscopes, such as transnasal endo-scopes, have been developed to alleviate discomfort during diagnosis and therapy. However, their application to optional diagnostics is limited since many optional diagnostic instruments are designed to fit through larger side channels. The aim of this study was to develop a smart endoscope that can obtain various diagnoses based on photoacoustic spectroscopy. The photoacoustic process comprises complex energy conversions involving optical, thermal, and elastic processes. This work focused on the scaling potential of photoacoustic sensors. Photoacoustic sensors with two different volumes were developed, and the amplitudes and frequency responses of the photoacoustic signals for silicone rubbers with six different Young's moduli were investigated. The results showed that photoacoustic signals can be enhanced by reducing the volumes of the sensors. Embedding a miniaturized photoacoustic sensor in an endoscope was confirmed to improve the sensitivity.

Coated thermoelectric refrigeration is a means of infrared stealth for target. The study on the infrared characteristic of target that coated with thermoelectric refrigeration is the foundation for infrared stealth technology coated with thermoelectric refrigeration. The infrared characteristic model of target coated with thermoelectric refrigeration was established considering of complex energy exchange of target on the sea and the structure and transfer character of thermoelectric refrigeration. Analyze the effect of current and hot-side transfer coefficient on the surface temperature of target by making corresponding program. Depending on the target and background temperature consistent standard, ideal current in a day was designed.

The first ever NATO Advanced Study Institute devoted to `Thermodynamics and the Optimization of Complex Energy Systems' was held in July 1998 in Neptun, Romania. The ASI unified the field by bringing together leading researchers from engineering and physics, and from West and East. This note outlines the objectives and proceedings of the Institute, which reviewed the most recent advances in exergy analysis, entropy-generation minimization and thermoeconomics. Directions for future developments (e.g. constructal theory) are also outlined.

A new approach to time-frequency analysis of fetal heart rate (FHR) variability is the matching pursuit (MP) method. MP analysis is proposed as away to capture complex energy structures ranging from burst-type to continuous activity in the time-frequency plane that other methods such as power-spectrum analysis and wavelet transforms may not detect. This article summarizes previous FHR analysis techniques, presents the MP algorithm, and shows the advantages of the MP method over other methods of FHR analysis.

A simple cogeneration system consisting of a regenerative gasturbine system and a heat-recovery steam generator serves as an example to illustrate the application of exergoeconomic methods for evaluating and optimizing complex energy systems. We discuss various exergycosting approaches, the exergoeconomic variables, and the procedures used in evaluating and optimizing energy systems.

This study presents a comparison of an in-house developed tool called Artificial Neural Network Model Developer (ANNMD) and commercial software for modeling with Artificial Neural Networks (ANNs). The development of ANNMD is based on initiatives from previous experiences in ANN modeling of complex energy systems which require extensive examination of measured parameters in order to obtain reliable ANN models. The ANNMD is a generic tool the main idea of which is to perform fast, user-friendly modeling and with automated sensitivity analysis (SA) in conjunction with parameters that are important in every ANN modeling. In addition, commercial software for ANN modeling - which has been present on the market for more than a decade - was used. The comparison was established on the same basis with respect to network configuration, main training settings and data used, hence enabling as objective analysis as possible. Modeling time, number of trainings and model's accuracy obtained by the two tools were the measures for the comparison.

The number of office buildings with highly fenestrated facades is currently increasing in Lithuania and neighboring countries. Highly fenestrated facades reduce energy consumption for lighting and simultaneously increase energy consumption for heating, cooling, air conveying and may cause thermal and visual discomfort. Pursuing to reduce negative effects of the highly glazed facade, special glasses are frequently used. However, such windows usually increase demand for lighting energy. Therefore, when making early decisions about glazing the building, it is important to have a complex evaluation of energy demand related to the specific case. The paper presents the results of analysis made using energy simulation tools. The obtained results have shown that when shading is not applied, the north is the most energy efficient orientation to glazing for an air conditioned office building in cool climate zones like Lithuania. The most energy efficient window‐to‐wall ratios (WWR) for the south, east and west oriented façade are 20%, whereas for the north it makes 20–40%. However, such WWR values do not satisfy standard requirements for day lighting. Santrauka Pastaraisiais metais Lietuvoje ir kaimyninese šalyse daugeja administracines paskirties pastatu, kuriu dauguma išoriniu atitvaru yra skaidrios. Didesnis istiklinimo plotas lemia mažesnius energijos poreikius apšvietimui, tačiau didina šildymo ir vesinimo sistemu energijos poreikius, sukelia šilumini bei vizualini diskomforta. Neigiamai dideliu skaidriu atitvaru itakai sumažinti naudojami tamsinti ir kitu specialiu charakteristiku stiklai, tačiau tai savo ruožtu didina energijos poreiki apšvietimui. Todel, priimant sprendimus del pastato istiklinimo, svarbu prieš tai kompleksiškai išnagrineti konkretaus sprendimo itaka pastato energijos poreikiams. Straipsnyje pateikiama modeliuojant gautu rezultatu analize. Rezultatai parode, kad vesaus klimato šalyse, kurioms priklauso ir Lietuva, kondicionuojamu administraciniu pastatu fasadu, kai nenaudojamos apsaugos nuo saules priemones, energiškai efektyviausias istiklinimas yra i šiaures puse. Energiškai efektyviausias santykinis fasado istiklinimo plotas pietines, rytines ir vakarines orientacijos fasadams yra 20 %, o šiaurines ‐ 20–40 %. Tačiau tokie istiklinimo plotai neatitinka norminiu natūralaus apšvietimo reikalavimu. Reikšminiai žodžiai: administracinis pastatas, istiklinimas, šildymas, vesinimas, apšvietimas, energijos poreikiai, mode‐liavimas

In response to a request by Picatinny Arsenal, the Pacific Northwest National Laboratory (PNNL) was asked by the Army to conduct an energy audit of the Arsenal’s 3000 Area Laboratory Complex. The objective of the audit was to identify life-cycle cost-effective measures that the Arsenal could implement to reduce energy costs. A “walk-through” audit of the facilities was conducted on December 7-8, 2009. Findings and recommendations are included in this document.

The relationship between the commonly used definitions for a resonance referring either to the asymptotic features of the scattering (real energy) or to the Gamow-Siegert (complex energy) wavefunctions is studied. In a one-channel model this can be achieved by analytical continuation of the scattering amplitude, asymptotic phase shift and collisional time delay functions in the complex energy plane. A separate study of the real and imaginary parts of the scattering functions brings new and unexpected features which, particularly in the near resonanceregion, can be used as keys of a more accurate determination of resonance characteristics,i.e. energy and lifetime. In addition, in the close vicinity of the resonance the predictions of the model go beyond an isolated resonance approximation including background and overlapping resonances.

The new Modelica library FluidFlow is being developed for the thermo-hydraulic simulation of complex energy supply systems. This library includes standard hydraulic model classes and specialized components for HVAC-systems and solar thermal systems. Most of these Modelica classes are modelled with equations of the 1Dtransient energy transport. The validation of the library takes place both by measuring values from test stations and by comparing with detailed CFD models. A first complex use case of the library represents the simulations-based design of a complex thermal energy supply system of a residential area, as a part of a newly built city in Iran.

Locating the causes of malfunctions in complex energy systems is an extremely difficult task, since more than one fault mode may produce similar and possibly undistinguishable patterns of effects. This paper shows how fuzzy expert systems can exploit the available measurements from the data acquisition system to identify different component and sensor fault modes. Real sensor data (mass flow rates, pressures, temperatures, and key operating parameters) are compared with the expected values of the same quantities that are calculated using numerical models of local subsystems. This comparison simply determines if the differences between measured and expected values are “negative,” “zero,” or “positive” in fuzzy logic terms. The final objective is to verify the existence of some patterns of these attributes that univocally identify the considered fault modes. These patterns are then implemented as the set of rules forming the knowledge base of a fuzzy expert system. The proposed diagnostic methodology is tested on the gas section of a real combined-cycle cogeneration plant, and the effect of measurement noise is also discussed.

To overcome future stringent regulations on pollutant emissions and to decrease CO emissions and fuel consumption, hybrid vehicles seem to be one of the near future most promising technologies. This type of car uses complex energy management and control strategy. Simulation can be very useful for the development of such a control system. This paper highlights a new library developed under the AMESim software that enables the simulation of complex interactive systems in vehicles. In addition, the possibility to combine with other AMESim modules, allows the users to add more complexity to any of the sub-components of the vehicle. As an illustration of this new tool capability, we propose in this paper a simulation example of the Prius, the most known hybrid vehicle which was the first commercial vehicle in 1997 and selected as the 2004 Car of the Year in Europe. Comparisons between measurements and simulations of the response of different components are presented on different driving cycles.

This paper presents a summary of our most recent advances in Thermoeconomic Diagnosis, developed during the last three years, and how they can be integrated in a zooming strategy oriented toward the operational diagnosis of complex systems. In fact, this paper can be considered a continuation of the work presented at the International Conference ECOS’99 in which the concepts of malfunction (intrinsic and induced) and dysfunction were analyzed in detail. These concepts greatly facilitate and simplify the analysis, the understanding, and the quantification of how the presence of an anomaly, or malfunction, affects the behavior of the other plant devices and of the whole system. However, what remains unresolved is the so-called inverse problem of diagnosing, i.e., given two states of the plant (actual and reference operating conditions), find the causes of deviation of the actual conditions with respect to the reference conditions. The present paper tackles this problem and describes significant advances in addressing how to locate the actual causes of malfunctions, based on the application of procedures for filtering induced effects that hide the real causes of degradation. In this paper a progressive zooming thermoeconomic diagnosis procedure, which allows one to concentrate the analysis in an ever more specific zone is described and applied to a combined cycle. In an accompanying paper the accuracy of the diagnosis results is discussed, depending on choice of the thermoeconomic model.

The Raman amplitude when extended into the complex energy plane can have zeros in the right-half plane. Minimum phase approaches to invert the Raman excitation profile (REP) to recover the Raman amplitude are valid only for the case where the Raman amplitude does not admit zeros in the right-half plane. A minimum phase algorithm applied to a REP gives a unique amplitude, but this amplitude and its corresponding cross-correlation function are wrong if the REP corresponds to a nonminimum phase problem. The minimum phase treatment therefore does not carry all possible physical information for a nonminimum phase REP.

Diagnosis of energy systems mainly consists of detecting and locating anomalies that cause reduction in the system efficiency or can cause major failures. This is an important task due to its economic implications. The attention is here focused on the anomalies that affect the system efficiency. The problem of their location is not easy to solve, due to some ‘disturbs’ that make propagate the effects of an anomaly throughout the system. These effects are caused by the dependence of the components’ behavior on their operating conditions. Moreover they can be amplified by the intervention of the control system and the variations in ambient conditions, fuel quality and plant load. A technique for highly complex system has been proposed in [1]. This procedure, based on the hypothesis of small malfunctions, consists of the progressive elimination of the disturbs, so that the anomalies could be more clearly highlighted. In this paper, a procedure particularly suitable for the application to operating plants is adopted to overcome the hypothesis of small malfunction. It consists of a combination of two techniques: 1) the use of neural networks for the elimination of the malfunctions [2] induced by the dependence of efficiency of components on the operating conditions and 2) the successive application of the analysis to several operating conditions selected within the plant case history.Copyright © 2003 by ASME