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Solar cell modelling primarily involves the formulation of the non-linear current versus voltage (I-V) curve. Determination of parameters plays an important role in solar cell accurate modelling. This paper presents an application of the hybrid Nelder-Mead simplex search method and modified Particle Swarm Optimization technique for identifying the parameters of solar cell and photovoltaic module models. The proposed technique is used to identify the unknown model parameters, namely, the generated photocurrent, saturation current, series resistance, shunt resistance, and ideality factor that govern the current-voltage relationship of a solar cell. A measurement data of 57mm diameter commercial (R.T.C. France) silicon solar cell and a module consisting of 36 polycrystalline silicon cells (Photowatt-PWP 201) are used to test and verify the consistency of accurately estimating various parameters. Comparative study among different parameter estimation techniques is presented to demonstrate the effectiveness of the proposed approach. Furthermore, to verify the accurateness of the proposed technique, an experimental test bench unit is built using 72 mono-crystalline silicon cells (HIP-210NKHB5-2 module) on different environment conditions. [ABSTRACT FROM AUTHOR]

An electric vehicles aggregator is in fact an intermediate between electric vehicles and the operator of the power grid. The Electric Vehicles (EVs) aggregator is responsible for the management of EVs in order to supply the owners with their orders and also for maximizing the profit of the power grid in the electricity market. In this study, an optimization model was developed for the operation of the EVs aggregator with an energy storage system in the reserve services market of the distribution network. In the proposed model, the reserve services market was formed after termination of the energy market. In this paper, the markets were created 24 h earlier. [ABSTRACT FROM AUTHOR]

Energy efficiency applications have great importance for facilities that utilize large amount of electrical and heat energy. Cogeneration (so called Combined Heat and Power; abbreviated as CHP) plants with gas engines are capable of generating both electrical and heat energy simultaneously using a single fuel input. In recent years, the realization of license exemption for facilities willing to produce electricity just for their energy demands by ensuring the condition of 80% total efficiency, low carbon emission of systems contain gas engines, rapid operation for synchronization and shortness of payback periods make cogeneration and trigeneration (so called Combined Cooling, Heat and Power; abbreviated as CCHP) plants more popular. This paper (i) briefly reviews cogeneration and trigeneration plants and their advantages, (ii) presents a novel methodology to determine the optimal capacity ratings for the plants by using the energy consumption profile, (iii) illustrates the calculation procedures including economic profit, thermal efficiency, and electricity generation of the selected system, and (iv) suggests the optimal capacity, plant placement and configuration for a medium-scale hospital. The energy savings potential at the university hospital is estimated as 19.66% and 19.52% with the use of natural gas based cogeneration and trigeneration plant, respectively. [ABSTRACT FROM AUTHOR]

Driven by the need to reduce the power consumption of mobile devices, and servers/data centers, and yet continue to deliver improved performance and experience by the end consumer of digital data, the semiconductor industry is looking for new technologies for manufacturing integrated circuits (ICs). In this quest, power consumed in transferring data over copper interconnects is a sizeable portion that needs to be addressed now and continuing over the next few decades. 2.5D Through-Si-Interposer (TSI) is a strong candidate to deliver improved performance while consuming lower power than in previous generations of servers/data centers and mobile devices. These low-power/high-performance advantages are realized through achievement of high interconnect densities on the TSI (higher than ever seen on Printed Circuit Boards (PCBs) or organic substrates), and enabling heterogeneous integration on the TSI platform where individual ICs are assembled at close proximity (<1mm separation) compared with several centimeters on a typical PCB. In this paper, we have outlined the benefits of adopting 2.5D TSI technology and also highlighted the current day approaches to implement this technology in Si fabrication facilities, and in assembly/packaging factories. While the systems and devices that power the mobile society benefit from exploiting advantages of 2.5D integration on TSI, there do exist surmountable challenges that need to be addressed for this relatively new technology to be used in high volume production of next generation semiconductor devices. The key areas of focus and challenges include: Technology planning and design-execution that are necessary for harnessing 2.5D TSI for building systems, processing flow for the fabrication of 100 μm thick TSI at acceptable costs, manufacturing flow for assembling multiple ICs on a 100 μm thick TSI in a repeatable, and reliable manner, thermo-mechanical analysis and optimization for addressing warpage issues, and thermal management for addressing heat dissipation. We have outlined design, manufacturing methodologies, and challenges, along with solutions to the challenges associated with taking 2.5D TSI technology to high volume production within the next few years. [ABSTRACT FROM AUTHOR]

The inertia plays a significant role in the response of a system undergoing flowinduced vibrations, which has been extensively investigated by previous researchers. However, the inertial effects of an energy harvester employing the mechanism of flow-induced vibrations have attracted little attention. This paper concentrates on a semi-passive energy extraction system considering its inertial effects. The incompressible Navier-Stokes equations are solved using a finite-volume based numerical solver with a moving grid technique. A partitioned method is used to couple the fluid and structure motions with the sub-iteration technique and an Aitken relaxation, which guarantees a strong fluid-structure coupling. In addition, a fictitious mass is added to resolve the numerical instability aroused by low density ratios. First, at a fixed mass ratio of r = 1, we identify an optimal set of parameters, at which a maximum efficiency of η = 34% is achieved. Further studies with r ranging from 0.125 to 100 are performed around the optimal parameters. The results show that for the semi-passive flapping energy harvester, the energy harvesting efficiency decreases monotonically with increasing mass ratio. We also notice that the total power extraction stays at a high level with little variation for r < 10; therefore, if we concern more about the amount of power extraction rather than its efficiency, the inertial effects can be neglectable for r < 10. Moreover, since one degree of freedom is released for the semi-passive system, it is possible for the system to automatically determine its optimal operational parameters. We note that the optimal phase difference ɸ = 82° has been well determined, which leads to a good timing of vortex-foil interactions. We note two different trends on phase difference for the effects of reduced frequency and mass ratio, respectively. By varying the reduced frequency ƒ *, an optimal ƒ* is identified, at which the minimum phase difference is achieved. While the relationship between phase difference and mass ratio is monotonic, a maximum phase difference is achieved at the nearly zero mass ratio. Nevertheless, both trends point to the same optimal phase difference, i.e., ɸ = 82° at θ0 = 75°. Furthermore, the relationship between the leading edge vortex and the phase difference is systematically investigated, accounting for the physical reason of existence of the optimal phase difference. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the Cauchy problem for the incompressible resistive Hall-magnetohydrodynamic equations with horizontal dissipation. By using very delicate energy estimate, we establish a blow-up criterion for the classical solutions and show the global-in-time existence of the classical solution for small initial data. [ABSTRACT FROM AUTHOR]

Effects of the secondary electron emission (SEE) phenomenon of metal surface on the multipactor analysis of microwave components are investigated numerically and experimentally in this paper. Both the secondary electron yield (SEY) and the emitted energy spectrum measurements are performed on silver plated samples for accurate description of the SEE phenomenon. A phenomenological probabilistic model based on SEE physics is utilized and fitted accurately to the measured SEY and emitted energy spectrum of the conditioned surface material of microwave components. Specially, the phenomenological probabilistic model is extended to the low primary energy end lower than 20 eV mathematically, since no accurate measurement data can be obtained. Embedding the phenomenological probabilistic model into the Electromagnetic Particle-In-Cell (EMPIC) method, the electronic resonant multipacting in microwave components can be tracked and hence the multipactor threshold can be predicted. The threshold prediction error of the transformer and the coaxial filter is 0.12 dB and 1.5 dB, respectively. Simulation results demonstrate that the discharge threshold is strongly dependent on the SEYs and its energy spectrum in the low energy end (lower than 50 eV). Multipacting simulation results agree quite well with experiments in practical components, while the phenomenological probabilistic model fit both the SEY and the emission energy spectrum better than the traditionally used model and distribution. The EM-PIC simulation method with the phenomenological probabilistic model for the surface collision simulation has been demonstrated for predicting the multipactor threshold in metal components for space application. [ABSTRACT FROM AUTHOR]

The spherical torus or spherical tokamak (ST) is a member of the tokamak family with its aspect ratio (A=R0/a) reduced to A~1.5, well below the normal tokamak operating range of A≥2.5. As the aspect ratio is reduced, the ideal tokamak beta β (radio of plasma to magnetic pressure) stability limit increases rapidly, approximately as β~1/A. The plasma current it can sustain for a given edge safety factor q-95 also increases rapidly. Because of the above, as well as the natural elongation κ, which makes its plasma shape appear spherical, the ST configuration can yield exceptionally high tokamak performance in a compact geometry. Due to its compactness and high performance, the ST configuration has various near term applications, including a compact fusion neutron source with low tritium consumption, in addition to its longer term goal of an attractive fusion energy power source. Since the start of the two mega-ampere class ST facilities in 2000, the National Spherical Torus Experiment in the United States and Mega Ampere Spherical Tokamak in UK, active ST research has been conducted worldwide. More than 16 ST research facilities operating during this period have achieved remarkable advances in all fusion science areas, involving fundamental fusion energy science as well as innovation. These results suggest exciting future prospects for ST research both near term and longer term. The present paper reviews the scientific progress made by the worldwide ST research community during this new mega-ampere-ST era. [ABSTRACT FROM AUTHOR]

Urban areas are the key drivers of energy usage and the associated carbon emissions. Due to the rapid economic development and urbanization process, China has faced increasing pressure on energy supply and carbon emission issues. It is urgent for China to change from the current coal-based high carbon intensity power supply structure. In this context, China has planned to utilize an undeveloped area in Shenzhen to become a low-carbon development demonstration project. The purpose of this paper is to propose the best combination of technology for electricity generation, involving a mix of renewable energy resources, to satisfy electrical needs and, at the same time, minimize carbon emissions from power generation in the low carbon demonstration area. The optimal renewable energy system configuration was determined based on the Hybrid Optimization Model for Electric Renewable model. The simulation results show that costs of energy for the three scenarios considered are $0.187/kW h, $0.128/kW h, and $0.150/kW h, respectively; annual carbon emissions for the three scenarios are 96 702 tons, 89 836 tons, and 78 065 tons, respectively. Given the economic advantage, scenario 2 is a suitable choice for the first phase of the international low carbon city (ILCC). With reinforced carbon emissions controls and a rising carbon allowance price, scenario 3 can be adopted in the second and third phase of the ILCC construction. [ABSTRACT FROM AUTHOR]

This paper applies the hybrid meta-frontier data envelopment analysis model to estimate the energy efficiency of the eastern, central, western, and northeastern regions in China as well as all Chinese provinces during 2003-2012. We further compare the energy efficiency under the regional frontier and the meta-frontier for different provinces and then examine the convergence situation among these four regions in China as well as the national energy efficiency. The results show the evidence of big gaps in the energy efficiency between the provinces under both the regional frontier and the national meta-frontier. In general, the highest energy efficiency lies in eastern China, followed by western China and then northeastern China, with the lowest in central China. Using the technology gap ratio, the findings present that eastern China achieves the national potential optimized production technology, whereas the central, western, and northeastern regions are still some distance away from their own national potential optimized production technology with considerable room for improvement. As for the variation trends of energy efficiency, those of the central and northeastern regions have a convergence tendency, whereas the energy efficiencies of eastern and western China show the characteristics of slight divergence. Moreover, the convergence tendency of energy efficiency for the whole country has not yet been formed. Based on the above research conclusions, we propose a number of energy policy recommendations for China's government in order to improve energy efficiency. [ABSTRACT FROM AUTHOR]

Energy is essential for the development of a city. The energy structure of China, dominated by coal, has caused serious problems, such as resource depletion, environmental pollution, and climate change. These problems have posed severe challenges to the sustainable development of mega--cities such as Shanghai. In order to ensure security of energy supply and alleviate the corresponding environmental pollution, these cities should effectively restructure their energy supply. This paper quantitatively analyzed the future energy consumption demand in Shanghai and its effects on environmental quality based on the MARKAL model with the aim of providing theoretical support for the government decision regarding energy policy, energy technology, adjustment of energy supply structure, etc. Different scenarios have been set up in light of the natural gas distributed supply system, clean and efficient coal-fired power technologies, energy-saving of industrial boilers technologies, Integrated Gasification Combined Cycle (advanced power generation technology), and wind power technologies. The results obtained by the MARKAL model show that total consumption of the whole society energy in Shanghai will reach 143 572 700 tons of standard coal in 2015, and 199 645 800 tons of standard coal in 2020. Thus, the future demand for energy consumption is huge astronomical, with about an average annual growth rate of 4%. The consumption of coal and other primary energy could decline by improving the energy efficiency and increasing renewable energy use, which would reduce pollutants emissions. At the same time, Shanghai should continue research on carbon dioxide emissions technology and its application in response to climate change. [ABSTRACT FROM AUTHOR]

The paper deals with a comparative analysis (in terms of energetic efficiency) between the mono-axis and dual-axis tracking solutions implemented on a photovoltaic (PV) string. The study reveals which solution is more efficient in the geographical area of Braşov, and under which conditions. The tracking efficiencies of the mono-axis and dual-axis systems are compared considering two orientation programs: seasonal and annual. Taking into account the technical and economical aspects, besides the energy gain of the dual-axis system, it was concluded that a mono-axis tracking system is preferred for the studied geographical area. The study is performed by using the virtual prototype of the PV tracking system, which is approached in mechatronic concept. An algorithm for the optimal design of the step-by-step tracking law is also developed, the maximization of the energetic efficiency of the PV string with solar tracker being the optimization goal. Finally, experimental data are used to validate the simulation results. [ABSTRACT FROM AUTHOR]

Given the rapid increase of residential energy consumption in Beijing, the question of how to promote residential energy-saving behavior is an emerging topic that is increasingly engaging the attention of scholars. To address this issue, this paper provides an empirical analysis that identifies and explores the determinants of an energy-saving behavioral intention among residents from the perspective of the theory of planned behavior (TPB). A theoretical model was constructed by refining and extending the classic TPB model according to the scope and requirements of this study and the existing situation in China. Survey data collected from 276 residents in Beijing were analyzed, and hypothesized relationships in the model were then verified using a structural equation model. The results show that subjective norms, environmental attitudes, information publicity, lifestyles, and perceived behavioral control significantly influence residents' energy-saving behavior, while demographic factors, such as educational background, household income, and age, had no obvious effects on behavioral intentions. Although knowledge regarding energy did not exert a direct influence on residents' energy-saving behavioral intentions, it did exert an indirect influence via environmental attitudes. Our results indicate that the role of households in saving energy expenditure should be emphasized, and financial incentives could be adopted to help promote environmental awareness among Beijing's residents. In addition, environment-friendly and energy-saving habits should also be inculcated. [ABSTRACT FROM AUTHOR]

To compensate for the limitation of the energy intensity indicator and to constrain energy consumption growth more directly and severely, China had decided to implement the Total Energy Consumption Control (TECC) policy during the 12th Five-Year Plan (FYP). This paper analyzes the situation of energy consumption in 3 scenarios based on the energy consumption trend during the 11th FYP, the energy intensity reduction target during the 12th FYP, and the TECC policy. The Energy Conservation Comprehensive Evaluation System (ECCES) which includes 5 indicators reflecting energy conservation responsibility and 3 indicators reflecting energy conservation difficulty has been built, and Analytic Hierarchy Process (AHP) and Entropy methods are used to determine the weights of 8 basic indicators. According to the ranking of comprehensive evaluation scores of ECCES, 30 provinces are divided into 5 clusters, which are assigned 3%, 3.5%, 4.2%, 5.5%, and 6.8% of controlled energy consumption growth rate, respectively. By comparing and analyzing energy consumption situations in 3 scenarios, we find that the TECC policy has the strongest constraint effect, and can achieve unification of provincial and national energy conservation goals. The provincial decomposition result of energy consumption controlled target of TECC policy roughly remains consistent with the current economic and energy development layout of China that the provinces in southeast coastal developed areas are assigned lower controlled energy consumption growth rate while the backward inland provinces are assigned higher growth rates. [ABSTRACT FROM AUTHOR]

Microwave applicators are widely employed for materials heating in scientific research and industrial applications, such as food processing, wood drying, ceramic sintering, chemical synthesis, waste treatment, and insect control. For the majority of microwave applicators, materials are heated in the standing waves of a resonant cavity, which can be highly efficient in energy consumption, but often lacks the field uniformity and controllability required for a scientific study. Here, we report a microwave applicator for rapid heating of small samples by highly uniform irradiation. It features an anechoic chamber, a 24-GHz microwave source, and a linear-to-circular polarization converter. With a rather low energy efficiency, such an applicator functions mainly as a research tool. This paper discusses the significance of its special features and describes the structure, in situ diagnostic tools, calculated and measured field patterns, and a preliminary heating test of the overall system. [ABSTRACT FROM AUTHOR]

This paper presents a load shifting algorithm for optimizing consumption patterns by taking preferences of customers and electricity costs into account. A load shifting cost component is introduced for recording inconvenience experienced by customers while load shifting. Load shifting cost reflects the reluctance of customers for their inconvenience where the customers are unique in terms of their preferences and costs. The proposed algorithm would allow demand side management to be conducted in a decentralized manner, where no problem of load synchronization exists. Multi-agent system based simulation studies were carried out on three types of customers namely, residential, commercial, and industrial customers to verify this algorithm. The simulation results show that substantial load levelling is achieved by the proposed algorithm. This study is further extended to examine the effects of incentives that encourage customers to participate in load shifting. However, this does not lead to a better load levelling perhaps due to the small sample sized simulation systems. Instead, incentives could be used as a short-term measure for customers to know that how the mechanism would work for them. [ABSTRACT FROM AUTHOR]

To make renewable Micro-Grid (MG) systems work as a sustainable set, one confronts a multi-objective, multi-constraint problem. To optimally operate these hybrid energy systems, one should consider the problems due to huge amount of raw data achieved through several measuring systems in different sections in a MG. In this paper, a new Smart Energy Management System (SEMS) is proposed and tested via simulation studies. The proposed SEMS performs some critical tasks such as data acquisition, data processing, and determining control signals for the MG. Two objective functions are defined for the SEMS to minimize the total operating cost and the net emission of the fossil fueled Distributed Generators with respect to some technical and reliability (Expected Energy Not Supplied index) constraints for the MG. The simulation results show a promising performance of the proposed SEMS for smart micro-grids. [ABSTRACT FROM AUTHOR]

Incandescent radiation sources are widely used as mid-infrared emitters owing to the lack of alternative for compact and low cost sources. A drawback of miniature hot systems such as membranes is their low efficiency, e.g., for battery powered systems. For targeted narrow-band applications such as gas spectroscopy, the efficiency is even lower. In this paper, we introduce design rules valid for very generic membranes demonstrating that their energy efficiency for use as incandescent infrared sources can be increased by two orders of magnitude. [ABSTRACT FROM AUTHOR]

Biomass (straw) gasification with oxygen-enriched air was studied in a lab-scale entrained-flow gasifier. Effects of oxygen concentration (OC), equivalence ratio (ER), and reactor temperature on the produced gas composition, gasification index and tar yield were investigated. Compared with air, oxygen-enriched air as gasifying agent was beneficial to increase the H2 content, H2/CO ratio, and lower heating value (LHV) of the gas, and decrease the yield of tar contained in the flue gas. The H2/CO reached 1 when OC was 50%, which was an optimal value for dimethyl ether, methanol, and higher alcohol production in the process of alcohols synthesis. A reference value of OC was given approximately to 40% according to economic consideration. A reference value of ER was given around 0.25 when OC was 40%, achieved a relatively high LHV of 8.2 MJ/Nm3 and low tar yield of 2.6 mg/g. In addition, high reaction temperature could improve both gas quality and gasification indexes significantly. The better gasification performance achieved in the paper verified that the oxygen-enriched gasification was a good option for the improvement of direct air gasification. [ABSTRACT FROM AUTHOR]

Microalgae are considered a promising biofuel resource to fix carbon dioxide (CO2), which can support social development and environmental improvement in the future. In this paper, characteristics of microalgae growth with two parameters of solar radiation and ambient temperature are investigated based on industrial-scale microalgae bulk growth model of Quinn et al. By using this model, the potential biomass production of microalgae in China is estimated based on data of the available untilled lands and the weather to be 7.38 × 109 tonnes. This is 2.4 times larger than China's energy consumption of 3.08 × 109 tonnes standard coal equivalent in 2010, and satisfies that predicted with an exponentially increasing trend for 2020, and 89% of the amount predicted for 2030. The annual total CO2 emissions reduced is estimated to be 13.5 × 109 tonnes, which can improve the natural environment besides supplying sustainable production in China. [ABSTRACT FROM AUTHOR]

The control strategy applied to the oscillating system of the wave energy converters largely determines the overall system efficiency and thus the energy production. One of the first proposed control strategies for this type of device is the passive control. This type of control continues currently to be considered because it can be implemented in a simple way: short-term predictions about the performance of the wave are not needed when passive control is applied. Moreover, the power flow is unidirectional, and the extraction system is subjected to moderate peak powers so that costs and dimensions of the wave energy converter components can be reduced. The main disadvantage of passive loading control is the low energy production compared with other control strategies, such as the so-called reactive control which requires bidirectional power flow between the oscillating system and the generator. This way, the device can extract more energy from the waves, but the global system requires large energy exchanges between the oscillating device and the generator. These energy exchanges cause high losses, and thus the overall system efficiency significantly decreases. Furthermore, the reactive control system involves high oscillating excursions that can become unacceptable. In this paper, a point absorber converter that uses a linear direct-drive generator and power electronics converters jointly is considered. This article presents a passive control strategy that optimizes the power transferred from the generator to the power electronic converter considering the copper losses in the electric generator. Applying this approach, the generation system efficiency increases significantly, and similar values of the oscillating system's heave excursions and the peak-to-average power ratio for both the conventional and the proposed passive loading are found. The formulation of the proposed method is presented as well as time domain wave-to-wire simulations in both regular and irregular waves. [ABSTRACT FROM AUTHOR]

This paper presents economic and environmental effects by using monitoring data collected over a 2-yr period in geothermal heating and cooling facilities in Jungwon University, Korea. The facility has heating capacity of 7045 kW and cooling capacity of 5947 kW. Such monitoring data are rarely reported in the literature; thus, the evaluation based on long-term operational data will contribute greatly to the objective assessment of the geothermal heat pump system (GHPS) as a renewable energy resource. The effects of relative energy cost saving and reductions in CO2 emission were predicted for comparison with conventional heating and cooling systems. The GHPS was estimated to reduce energy costs by 76.4%-85.3% and yield a reduction of CO2 emission of 398-595 tons annually. We also conducted an economic analysis using the benefit/cost ratio (BCR) method according to scenarios in which the lifespan and discount rate for the GHPS were varied. Since the BCR for the GHPS was in the range of 1.99-3.58 (case 1) and 1.67-3.01 (case 2), GHPS is considered to be more economic than other types of heating and cooling systems. These results provide evidentiary data to help overcome skepticism over the applicability of large-scale GHPSs. [ABSTRACT FROM AUTHOR]

Chile is facing important challenges to develop its energy sector. Estimations demonstrate that in its electricity consumption Chile will grow at an annual rate of 4.6% until 2030, despite ongoing efficiency improvements. To satisfy this demand in a sustainable way, the national energy policy promotes the integration of novel and clean power generation into the national power mix, with special emphasis on concentrated solar power (CSP). The present paper assesses the development of solar-based electricity generation in Chile by CSP, achieved by a Solar Power Tower plant (SPT) using molten salt as heat carrier and store. Such SPTs can be installed at different locations in Chile, and connected to the main national grid. Results show that each SPT plant can generate around 76 GWhel of net electricity, when considering solar irradiation as the sole energy source and at a 16% overall efficiency of the SPT process. For operation in a continuous mode, a hybrid configuration with integrated gas backup system increases the generating potential of each SPT to 135 GWhel. A preliminary Levelized Energy Cost (LEC) calculation provides LEC values between 0.15 and 0.18 $/kWh, as function of the overall process efficiency and estimated investment cost. Chile's solar irradiation favors the implementation of SPT plants. [ABSTRACT FROM AUTHOR]

Nowadays, an increasing number of applications require high-performance analytical instruments capable to detect the temporal trend of weak and fast light signals with picosecond time resolution. The Time-Correlated Single-Photon Counting (TCSPC) technique is currently one of the preferable solutions when such critical optical signals have to be analyzed and it is fully exploited in biomedical and chemical research fields, as well as in security and space applications. Recent progress in the field of single-photon detector arrays is pushing research towards the development of high performance multichannel TCSPC systems, opening the way to modern time-resolved multi-dimensional optical analysis. In this paper we describe a new 8-channel high-performance TCSPC acquisition system, designed to be compact and versatile, to be used in modern TCSPC measurement setups. We designed a novel integrated circuit including a multichannel Time-to-Amplitude Converter with variable full-scale range, a D/A converter, and a parallel adder stage. The latter is used to adapt each converter output to the input dynamic range of a commercial 8-channel Analog-to-Digital Converter, while the integrated DAC implements the dithering technique with as small as possible area occupation. The use of this monolithic circuit made the design of a scalable system of very small dimensions (95 × 40 mm) and low power consumption (6 W) possible. Data acquired from the TCSPC measurement are digitally processed and stored inside an FPGA (Field-Programmable Gate Array), while a USB transceiver allows real-time transmission of up to eight TCSPC histograms to a remote PC. Eventually, the experimental results demonstrate that the acquisition system performs TCSPC measurements with high conversion rate (up to 5 MHz/channel), extremely low differential nonlinearity (<0.04 peak-to-peak of the time bin width), high time resolution (down to 20 ps Full-Width Half-Maximum), and very low crosstalk between channels. [ABSTRACT FROM AUTHOR]

Currently, energy-saving and carbon dioxide reduction are the most critical issues faced by the globe. Therefore, solar energy should be used as much as possible. A possible use is to illuminate a solar cell so as to transform light energy directly into electricity. However, due to its low efficiency and high cost, the solar cell is not presently economically feasible. Utilization of solar energy, which is considered one of the most important renewable energy sources, not only reduces consumption of fossil fuel but also slows down the pace of global warming. In addition to the use of solar cells, daylight illumination is also an important access to solar energy. Our team has developed a technique that can guide the natural light to the interior for indoor illumination. It is called the 'Natural Light Guiding System.' Our system can guide sunlight to the interior, but the distribution of light at the exit of the system is disordered. To solve this problem, we have proposed an optical coupling transmission structure with right-angled prism collecting modules. We analyzed the mathematical model of coupling transmission. And, we also analyzed the efficiency of this cascade structure at the exit surface of the concentrator. In this paper, we provide a high efficiency new concentrator coupled to a transmission device. We save 75% of the optical fiber cable expense usage and we improve efficiency by 47.46% when we add an optical coupling transmission structure to our static lighting concentrator. It is better than the original cascade prism static concentrator. Taking the fiber cost into consideration, we defined a key performance index-it is a ratio of luminous flux on an illuminated area. Our system can provide more powerful light for indoor illumination than existing methods The optical coupling can provide high transmission efficiency and provide parallel light beams at the export from the optical coupling module. We used optical simulation tools to design and simulate the efficiency of the active module. We can use this system as an ecological illumination system to offer steady illumination in indoor space to provide healthy illumination, save energy, and meet safety requirements. [ABSTRACT FROM AUTHOR]

Jatropha curcas has been widely considered as a potential feedstock for production of biodiesel in several tropical countries. Globally biodiesel is gaining importance because of its environmental advantages. This paper deals with the energy consumption for the biodiesel production from J. curcas. Two plantation models of Jatropha, perennial and annual harvesting and their energy benefits are considered. In perennial plantation, the biodiesel yield is more than the annual harvesting. On the other hand, overall energy output from the annual harvesting system is almost twice than that of perennial system. The energy benefits of Jatropha cultivation on two different types of soil (poor and normal soils) were evaluated with and without irrigation. The energy balance is also calculated on the basis of rainfall and different water level depth. The study estimated the net energy balance and net energy ratio for both the models and found that the energy values were high for both the systems. [ABSTRACT FROM AUTHOR]

This paper presents the dynamic optimization of a pseudo-azimuthal tracking system for photovoltaic modules regarding the growth of energetic efficiency. The study targets on the one hand the optimization of the mechanical device of the tracking mechanism (developed with the mbs software solution adams), and on the other hand the optimization of the control system model (conceived with the dfc software easy5). The main aspect consists of using the same optimization techniques (optimal parametric design) for both major components of the mechatronic tracking system (the mechanical device and the control system). The optimization of the mechanical device is focused on the minimization of the motor force generated by the driving actuator (minimizing in this way the energy consumption for tracking), while the optimization of the control system leads to the maximization of the incident solar radiation gain by minimizing the tracking errors. [ABSTRACT FROM AUTHOR]

Very stable and reliable instruments with high accuracy are required in field measurements for continuous monitoring local geodynamic processes, such as tectonic movements, ground motions in landslide prone areas, etc. A sensitive borehole wire extensometer with low energy consumption was developed in the Geodetic and Geophysical Research Institute of the Hungarian Academy of Sciences to observe very small vertical movements (in the order of a few millimeters) of the upper layer of the soil due to hydrological, meteorological and biological processes. The newly developed instrument eliminates the disadvantages of the borehole wire extensometers which are presently used. Its sensitivity and stability are much higher than these parameters of the previous instruments. The instrument is able to measure distance variations without instrumental drift in a range of 0-4 mm with a resolution of better than 1 μm. Since the effect of the yearly temperature variations can be easily removed from the extensometric data record, the compensation for the short-periodic (daily) thermal effects on the instrument was of high priority during the design of the instrument. This paper describes the construction and calibration of the extensometer. The extensometer was installed for monitoring vertical ground movements due to hydro-meteorological processes on the high loess wall of the Danube River at Dunaföldvár, Hungary. The efficiency of the temperature compensation of the instrument was investigated in detail on the basis of the measured data series. [ABSTRACT FROM AUTHOR]

This paper begins with the recognition that climate zones influence nonprocess energy use in industrial buildings. Nonprocess energies are heating, cooling, lighting, and ventilation. Nonprocess energy data have been collected from the literature (about 68 buildings) across a wide range of climate zones. The hypothesis tested in this research is: if an industrial building has a characteristic nonprocess energy related to physical dimensions and desired comfort level, then using cooling degrees day (CDD) and heating degrees day (HDD) factors can normalize the measured nonprocess temperature control data for the climate zone differences. That is, do measured nonprocess energy intensities (W/m2), if corrected for climate zone differences, within each building category become more similar and hence reflecting the basic building temperature control energy use? The five U.S. climate zones and the location for each facility in this study were identified. To investigate how the location influences the amount of heating and cooling at each facility, a baseline analysis of five representative cities in each zone was done to obtain the 5-year average CDD and HDD. The reported values of heating and cooling for each facility were then adjusted using this baseline and the climate zones of that facility, so that each facility was then referenced to zone 3; that is, as if all manufacturing facilities were in the same zone 3. The mean, median, standard deviation, and total nonprocess energies for current and zone-adjusted nonprocess energy for each facility in this study were calculated. The mean values of current and adjusted heating and cooling remained close to each other and the standard deviation was not reduced by these adjustments. Thus, the hypothesis of using CDD/HDD to quantitatively account for and hence to adjust for different climate zones appears to not be valid. The absence of improvement (reducing the standard deviation) by normalizing heating and cooling energy using adjustment for climate factors using the concept of CDD/HDD implies that some other correction principles are needed for evaluating fundamental needs for industrial building heating and cooling. The inability to reduce the geographic (that is, climate zone) effects of industrial plant nonprocess energy intensities supports the de-emphasis of this tool in the ASHRAE Handbook. [ABSTRACT FROM AUTHOR]

In this paper, we analyze the possibility of using daylight as the main source of light for learning and teaching activities in a classroom building of the Universidade Tecnológica Federal do Paraná, in Curitiba, Brazil. Beginning with a survey on light bulb and luminaire types used in the building and on the potential of daylighting in such environments, six different classroom types with different solar orientations were selected for analysis. The research methods included the estimation of daylighting potential from obtained daylight coefficients (DCs) for periods of the year and sky conditions, other than those of the onsite measurements; the evaluation of conformity of the lighting system to the Brazilian RTQ Code (Regulamento Técnico de Qualidade), an energy consumption rating system, aimed at reducing electric energy consumption in office buildings; the estimation of electric energy demand for a combined use of daylighting and lighting system; the proposal of an efficient lighting system; and cost assessment using payback analysis. Results suggest energy savings of up to 94% when integrating daylight with the artificial lighting system, a payback within the range of 22-60 months for a complete substitution of the existing lighting system for a more efficient one. [ABSTRACT FROM AUTHOR]

Solar energy, which is inexhaustible and abundant, has become an economically viable and environmentally preferable alternative to fossil fuels. There is the inherent advantage of solar energy in mitigation of climate change, generation of employment, and reduction of poverty, as well as increased energy security and supply. It is therefore important to continue to evaluate the global solar radiation levels in countries such as Nigeria with considerably high solar energy potential. In this paper, we report such evaluation for southern Nigeria; in particular, the correlations of meteorological estimates from National Aeronautics and Space Administration (NASA) and calculated Hargreaves estimates for this region of Nigeria (latitude of 4.75°-7.77°N and longitude of 3.33°-8.32°E) are carried out and the results show a good agreement in all the sites, thereby strengthening the case we make for decentralized renewable energy investments in the region. [ABSTRACT FROM AUTHOR]

This paper describes a 4.596 GHz frequency synthesis based on a 2.1 GHz solid mounted resonator (SMR) voltage-controlled oscillator (VCO). The SMR oscillator presents a chip size lower than 2 mm2, a power consumption of 18.2 mW, and exhibits a phase noise of -89 dBc/Hz and -131 dBc/Hz at 2 kHz and 100 kHz offset frequencies, respectively. The VCO temperature-frequency dependence is measured to be -14 ppm/°C over a range of -20 ○C to 60 ○C. From this source, a low noise frequency synthesizer is developed to generate a 4.596 GHz signal (half of the Cs atom hyperfine transition frequency) with a phase noise of -81 dBc/Hz and -120 dBc/Hz at 2 kHz and 100 kHz from the carrier. The frequency synthesis output is used as a local oscillator in a Cs vapor microcell-based compact atomic clock. Preliminary results are reported and discussed. To the authors knowledge, this is the first development of a SMR-oscillator-based frequency synthesizer for miniature atomic clocks applications. [ABSTRACT FROM AUTHOR]

The challenges associated with the development of innovative energy efficient technology require a new generation of skilled and creative scientists and engineers. Moreover, it is vital that they possess the ability to communicate their expertise to the general public and to serve as advisors and participants in the development of science policy. This paper describes a curriculum for a course in optics that. investigates the physical principles and policy aspects of solid state lighting. Recent legislation places stringent efficiency and reliability requirements on lighting, promoting the development of new commercial lighting options. The physics of solid state lighting fits naturally into the undergraduate optics curriculum, and the policy aspects provide students with an engaging connection between science and society. [ABSTRACT FROM AUTHOR]

Faster consumption of hydrocarbon fuel in the transport sector is posing global threat of depletion of fossil fuel reserves. Studies are being extensively done to search for an alternative energy source and/or to find out appropriate energy conversion system. Among various alternatives, the use of compressed atmospheric air in air turbine is an attractive option provided the atmospheric air is compressed by natural sources such as sun energy, wind energy, etc. It has the capability to produce shaft work with almost zero pollution in the environment. This paper details the mathematical modeling of a small capacity compressed air driven multivane air turbine. The effect of having different vane angles and inlet pressure on shaft work output has been studied and analyzed here. The study shows that the flow work has significant contribution in total work output and varies from 1.5% to 16.3% at different pressures, 2–6 bars, and injection angles, 30°–60°. The total shaft work is found to be maximum at vane angle θ=36° (ten vanes) when injection angle is kept at 60°, and it reduces at vane angle θ=45° (eight vanes) when injection angle is kept at 45° and further goes down at vane angle θ=60° (six vanes) when injection angle is 30°, if injection pressure is maintained at 6 bars and speed of rotation at 2500 rpm. [ABSTRACT FROM AUTHOR]

In this paper we draw up future roadmaps for technologies, policies, and optimal investment timing toward the achievement of a low-carbon society (LCS) in Japan by 2050. Future pathways for Japan to follow are calculated using an analytical model based on a backcasting methodology. Early actions can lead to pathways for minimizing the costs toward a LCS in Japan. However, to take early actions, large investments will be needed at the initial stages. The investment requirements for the residential and commercial sector and transportation sector will be especially costly: The former reaching 2.5 trillion JPY annually from 2010 to 2025 and the latter reaching 2.5 trillion JPY annually from 2010 to 2015. There are four main advantages to early actions. (1) Technologies have learning-by-doing effects: The additional cost of reducing CO2 emissions will fall as the technologies spread. (2) If actions are delayed, learning-by-doing effects may fail to work sufficiently, resulting in higher total investment requirements for achieving a LCS. (3) No infrastructure can be built immediately; hence it would be difficult to switch suddenly to a LCS in the years just before 2050. (4) Future technological development has several uncertainties. If the development of one of the currently dominant technologies falls behind schedule, it will fail to spread as expected and CO2 emission targets will not be met. Early actions will open up new opportunities for the spread of alternative actions toward the LCS should a dominant technology fail in some way. [ABSTRACT FROM AUTHOR]

Cities are responsible for nearly 75% of the world’s energy consumption; expectedly, about 90% of future growth will occur in urban areas. However, we consider that cities will be at the forefront of implementing groundbreaking technologies and policies, as evidenced in the initiatives taken by many cities here and worldwide to resolve issues in energy and climate change. In addition to affording energy and environmental benefits, investments in energy efficient and renewable technologies have huge potential to boost local economies, as demonstrated by the recent federal allocation of stimulus funding. Inclined to give priority to stopgap measures, many cities tend to regard comprehensive long-term planning as secondary. However, such solutions would bring multiple benefits to the community. The paper showcases an energy and environment systems model to provide a quantitative vision of technology and management strategy options for effectively deploying energy efficiency and renewable energy for reducing the carbon footprint, while sustainably maintaining the energy demands of the community and the servicing environmental infrastructure. We provide results of a case study completed for New York City, to showcase usefulness of long-term planning for achieving low carbon cities. Combined with appropriate stakeholder participation, such a technology explicit bottom-up approach holds the promise of influencing the current energy planning, environmental regulatory regime, including multimedia aspects of carbon control for cities locally and internationally. [ABSTRACT FROM AUTHOR]

Mid- and long-term energy requirements and greenhouse gas emission scenarios for China were presented by using the Integrated Policy Assessment Model of China. Technologies are the key component to reach a low carbon future. Technologies are identified with the scenario analysis. In order to realize the low carbon future, a technology roadmap was presented to reach the emission reduction up to 2050 in China. Twenty-eight key technologies are given in the paper for the technology roadmap, presenting learning curves. With full adoption of these key technologies, we do see ample opportunities for China to make the emission stable after 2020, without a large increase, and even start to have a deep reduction after 2030. [ABSTRACT FROM AUTHOR]

The aim of this paper is to define low carbon society (LCS) based on the phase diagram with the variables from the IPAT [Human Impact (I) on the environment equals the product of population (P) affluence (A) and technology (T)], starting from the problem definitions: (1) Economy is not everything for LCS and (2) it is not clear if speed on the constraint is more important than liberation from it. To tackle these problems, two research questions are set: (1) What are the basic indicators, objects, and constraints to shape the argument of LCSs and (2) what are the historical paths of several countries and what can be said for their future paths toward carbon societies? Time series data from 1900 or before are used, while the phase diagram with the variables from the IPAT equation is used as the core methodology. In addition to the IPAT variables, the importance of land per capita shall be considered as another basic indicator for LCS related to the carrying capacity. The three different kinds of objects [i.e., total gross domestic product (GDP), GDP per capita, and social indicator] and the two constraints (i.e., total emission and emission per capita) are considered, and it is shown that the combination of these objects and constraints strongly affects the argument of the carrying capacity of climate and land, development of economic system and economic man, and other human developments. Among the four cases analyzed in the phase diagram, the case where GDP per capita is object and total emission is constraint is given the most attention and requires the further research in the future since it does not contradict with a definition of LCS. It is also suggested that if changing the direction of the path with low carbon technology development takes time and cost, institutional arrangement would be additionally necessary in addition to market mechanism where optimal solutions are found on constraint. [ABSTRACT FROM AUTHOR]

Both the energy efficiency and correlation characteristics are important in airborne sonar systems to realize multichannel ultrasonic transducers working together. High energy efficiency can increase echo energy and measurement range, and sharp autocorrelation and flat cross correlation can help eliminate cross-talk among multichannel transducers. This paper addresses energy efficiency optimization under the premise that cross-talk between different sonar transducers can be avoided. The nondominated sorting genetic algorithm-II is applied to optimize both the spectrum and correlation characteristics of the excitation sequence. The central idea of the spectrum optimization is to distribute most of the energy of the excitation sequence within the frequency band of the sonar transducer; thus, less energy is filtered out by the transducers. Real experiments show that a sonar system consisting of eight-channel Polaroid 600 series electrostatic transducers excited with 2 ms optimized pulse-position-modulation sequences can work together without cross-talk and can measure distances up to 650 cm with maximal 1% relative error. [ABSTRACT FROM AUTHOR]

Globally, buildings are responsible for approximately 40% of the total world annual energy consumption. Most of this energy is for the provision of lighting, heating, cooling, and air conditioning. Increasing awareness of the environmental impact of CO2 and NOx emissions and chlorofluorocarbons triggered a renewed interest in environmentally friendly cooling and heating technologies. Under the 1997 Montreal Protocol, governments agreed to phase out chemicals used as refrigerants that have the potential to destroy stratospheric ozone. It was therefore considered desirable to reduce energy consumption and decrease the rate of depletion of world energy reserves and pollution of the environment. One way of reducing building energy consumption is to design buildings that are more economical in their use of energy for heating, lighting, cooling, ventilation, and hot water supply. Passive measures, particularly natural or hybrid ventilation rather than air conditioning, can dramatically reduce primary energy consumption. However, exploitation of renewable energy in buildings and agricultural greenhouses can also significantly contribute toward reducing dependency on fossil fuels. Therefore, promoting innovative renewable applications and reinforcing the renewable energy market will contribute to preservation of the ecosystem by reducing emissions at local and global levels. This will also contribute to the amelioration of environmental conditions by replacing conventional fuels with renewable energies that produce no air pollution or greenhouse gases. The provision of good indoor environmental quality (IEQ) while achieving energy and cost efficient operation of the heating, ventilating, and air-conditioning plants in buildings represents a multivariant problem. The comfort of building occupants is dependent on many environmental parameters including air speed, temperature, relative humidity, and quality in addition to lighting and noise. The overall objective is to provide a high level of building performance, which can be defined as IEQ, energy efficiency (EE), and cost efficiency (CE). IEQ is the perceived condition of comfort that building occupants experience due to the physical and psychological conditions to which they are exposed by their surroundings. The main physical parameters affecting IEQ are air speed, temperature, relative humidity, and quality. EE is related to the provision of the desired environmental conditions while consuming the minimal quantity of energy. CE is the financial expenditure on energy relative to the level of environmental comfort and productivity that the building occupants attained. The overall CE can be improved by improving the IEQ and the EE of a building. The increased availability of reliable and efficient energy services stimulates new development alternatives. Anticipated patterns of future energy use and consequent environmental impacts (acid precipitation, ozone depletion, and greenhouse effect or global warming) are comprehensively discussed in this paper. Throughout the theme several issues relating to renewable energies, environment, and sustainable development are exam-ined from both current and future perspectives. It is concluded that renewable environmentally friendly energy must be encouraged, promoted, implemented, and demonstrated by full-scale plant especially for use in remote rural areas. [ABSTRACT FROM AUTHOR]

This paper compares the use of sugar cane and corn for the production of ethanol, with a focus on global warming and the current international debate about land use competition for food and biofuel production. The indicators used to compare the products are CO2 emissions, energy consumption, sugar cane coproducts, and deforestation. The life cycle emission inventory as a methodological tool is taken into account. The sustainability of socioeconomic development and the developing countries’ need to overcome barriers form the background against which the Brazilian government energy plans are analyzed. [ABSTRACT FROM AUTHOR]

This paper presents the evaluation of properties of straight vegetable cotton seed oil (CSO) and its blends with diesel fuel in various proportions to evaluate the performance and emission characteristics of a single cylinder compression ignition (CI) engine at constant speed of 1500 rev/min. Diesel and CSO oil fuel blends (10%, 30%, 50%, and 70%) were used to conduct engine performance and smoke emission tests at varying loads of 0%, 20%, 40%, 60%, 80%, and 100% of full load in addition to their straight CSO and diesel fuel. The performance parameters of brake specific energy consumption (BSFC), brake thermal efficiency (BTE), mechanical efficiency (ME), exhaust gas temperature (EGT), and exhaust emission (smoke) were evaluated to find the optimum CSO and diesel fuel blend. From the experimental results, the CSO10D90 blend fuel showed 3.7% reduction in BSFC, 1.7% increase in BTE, 6.7% increase in ME, and 21.7% reduction in the smoke emissions in comparison with conventional diesel operated engine. Finally, it is concluded that CSO10D90 can be used straight away in CI engines without any major modifications to the engine as it showed good performance and improved emission compared to all other fuels tested for the entire range of engine operation in comparison with diesel. [ABSTRACT FROM AUTHOR]

In this paper, we present a numerical study on the thermocapillary migration of drops. The Navier–Stokes equations coupled with the energy conservation equation are solved by the finite-difference front-tracking scheme. The axisymmetric model is adopted in our simulations, and the drops are assumed to be perfectly spherical and nondeformable. The benchmark simulation starts from the classical initial condition with a uniform temperature gradient. The detailed discussions and physical explanations of migration phenomena are presented for the different values of (1) the Marangoni numbers and Reynolds numbers of continuous phases and drops and (2) the ratios of drop densities and specific heats to those of continuous phases. It is found that fairly large Marangoni numbers may lead to fluctuations in drop velocities at the beginning part of simulations. Finally, we also discuss the influence of initial conditions on the thermocapillary migrations. [ABSTRACT FROM AUTHOR]

We revisit a series of papers on science and society issues by David Hafemeister in the 1970s and 1980s. The emphasis in the present work is on world oil production limits and some consequences of various possible scenarios for the near future. Some of the data and scenarios used by Hafemeister are updated for U.S. oil production in the past two decades, and extended to an analysis of a peak in world oil production in the future. We discuss some simple scenarios for future energy use patterns and look at the consequence of these scenarios as world oil production begins to decline. We also provide a list of resources for critical investigations of natural resource extraction and depletion patterns. [ABSTRACT FROM AUTHOR]

This paper is concerned with the study of the Cauchy problem associated with an n-dimensional generalized Benney-Luke equation, utt-mΔu-Δutt+Δ2u+α(2∇u·∇ut+utΔu)+β∇(|∇u|p∇u)=0, where n=1,2,3,4. We prove the existence and the uniqueness of the global solution of the Cauchy problem for the β≼0 case by using energy conservation law and give the existence and the nonexistence of the global solution of the Cauchy problem for the β>0 case by constructing the stable set and the unstable set. [ABSTRACT FROM AUTHOR]

Since China's economic reforms and opening-up policy in 1980, China has experienced significant urbanization. This rapid urbanization has stimulated the growth of energy consumption. To investigate the impacts of urbanization on Chinese households' energy consumption, this paper analyzed the changes in households' direct energy consumption (DEC) and calculated households' indirect energy consumption (IEC) based on an energy input-output model. By applying an input-output structure decomposition analysis model, this paper quantitatively measured the impacts of urbanization on the direct and indirect energy consumption of households in China. We found that the amount of China's urban households' DEC gradually increased from 48.7 million tons of oil equivalent to 185.2 million tons of oil equivalent. In 2012, the proportion of coal products in urban households' DEC decreased from 91.4% in 1980 to 24.3%, while the proportion of petroleum products, natural gas, and electricity in urban households' DEC increased. During 1980 to 2012, China's rural households' DEC increased from 36.7 million tons of oil equivalent to 121.5 million tons of oil equivalent. However, the proportion of coal products was still greater than 50% in 2012. Chinese households' IEC increased from 302.8 million tons of oil equivalent in 1987 to 769.9 million tons of oil equivalent in 2010. In addition, China's urban households' IEC had a faster growth rate than China's rural households' IEC. Urban households' IEC increased from 139.0 million tons in 1987 to 599.8 million tons in 2010, while rural households' IEC fluctuated during the same period, with 163.8 million tons in 1987, 132.2 million tons in 2000, and 170.1 million tons in 2010. Among the impact factors of households' DEC, which include the population, urbanization rate, urban/rural households' DEC per capita and urban/rural households' DEC structure, China's total population has a positive effect on households' DEC growth. The urbanization rate is the other important factor constantly stimulating China's households' DEC growth. For households' IEC, the urbanization rate and per capita consumption had positive effects on the increase in households' IEC. Except for the period from 2002 to 2005, direct energy intensity had a negative effect on the increase in households' IEC in other periods. The Leontief effect on households' IEC was positive from 2000 to 2005 and negative in other subperiods. The results indicate that China needs to integrate energy efficiency, ecological conservation, and social fairness in its “new-type urbanization” planning. Green lifestyles within the household and low-carbon city construction should be encouraged. [ABSTRACT FROM AUTHOR]

The formation and development of the energy internet through energy hubs enhance energy efficiency and improve system operating flexibility to accommodate more renewable energy sources (RESs) under the pressure of energy crisis. To further tap the potential of energy complementary and optimize the total operating cost in an operational model of multi-energy hubs, an improved energy management system model for the energy conversions of flexibility-based energy hubs using the linearized coupling relationship is proposed in this paper, which could realize regional coordination optimization and high proportion of RES consumption. Furthermore, an algorithm, which combines a Linear Weighted Sum algorithm and the Kuhn-Tucker condition, is presented to utilize surplus energy among the different energy hubs rationally and solve the optimal energy management problem of the constrained nonlinear multi-objective dispatch model. Finally, the results of the simulation indicate that the total operating cost of multi-energy hubs participating in energy complementary is reduced by nearly 15.23% in summer and approximately 8.56% in winter, and the proposed approach can successfully reduce the waste of RES. [ABSTRACT FROM AUTHOR]

This paper proposes a hybrid autonomous electricity supply system for monasteries as a specific type of load. Chilandar monastery (Mount Athos, Greece) was presented as a case study. Taking into consideration specific location, historical significance, present and future needs of the monastery, and peculiar life style of its inhabitants, a new hybrid system for 400 kWh daily energy consumption and 80 kW peak load have been designed, proposed and elaborated here. It is based on combined use of three new diesel aggregates and a field of photovoltaic panels. Paper further outlines the methodology for selection and sizing up of power generating sources and other equipment. The primary goal for the new system was the reduction of diesel fuel and operational costs. Finally, cost-benefit analysis results of the proposed hybrid system are presented as well. [ABSTRACT FROM AUTHOR]

The article presents an updated transportation statistics for automobile and light truck usage in the U.S. in continuation to statistics presented in the paper titled "A Physicist's View of the Automobile Engine." Topics discussed include factors involved in data analysis such as average miles per gallon of automobiles, number of light trucks, and gasoline usage, classification of sport utility vehicles and minivans as light trucks, and increasing trends of using automobiles by students.

The article lists questions related to physics including which uses more energy from car and house, and is a plastic bag thicker than single coat of paint.