The contact condition influence on stability and energy efficiency of quadruped robot

NASA Astrophysics Data System (ADS)

Lei, Jingtao; Wang, Tianmiao; Gao, Feng

2008-10-01

Quadruped robot has attribute of serial and parallel manipulator with multi-loop mechanism, with more DOF of each leg and intermittent contact with ground during walking, the trot gait of quadruped robot belongs to dynamic waking, compared to the crawl gait, the walking speed is higher, but the robot becomes unstable, it is difficult to keep dynamically stable walking. In this paper, we mainly analyze the condition for the quadruped robot to realize dynamically stable walking, establish centroid orbit equation based on ZMP (Zero Moment Point) stability theory, on the other hand , we study contact impact and friction influence on stability and energy efficiency. Because of the periodic contact between foots and ground, the contact impact and friction are considered to establish spring-damp nonlinear dynamics model. Robot need to be controlled to meet ZMP stability condition and contact constraint condition. Based on the virtual prototyping model, we study control algorithm considering contact condition, the contact compensator and friction compensator are adopted. The contact force and the influence of different contact conditions on the energy efficiency during whole gait cycle are obtained.

Key Drivers of Marines Willingness to Adopt Energy-Efficient Technologies

DTIC Science & Technology

2013-12-01

influences the rate of adoption. Communication is “the process by which participants create and share information with one another in order to reach a...more likely to assess the value of the innovation themselves rather than the value of the implementer’s market . Kleijnen, Lee, and Wetzels (2009...willingness to ucc (~pt energy cftid(’nt technologil~. The adaptation of energy efficient technologies will significantly reduce fossil fuel der>endency

Energy Conservation

ERIC Educational Resources Information Center

Abelson, Philip H.

1972-01-01

Comments on The Potential for Energy Conservation,'' a study by the Office of Emergency Preparedness, emphasizing the coming dependence on foreign oil, and presses for government influence to encourage development of more efficient cars. (AL)

Warm Body Temperature Facilitates Energy Efficient Cortical Action Potentials

PubMed Central

Yu, Yuguo; Hill, Adam P.; McCormick, David A.

2012-01-01

The energy efficiency of neural signal transmission is important not only as a limiting factor in brain architecture, but it also influences the interpretation of functional brain imaging signals. Action potential generation in mammalian, versus invertebrate, axons is remarkably energy efficient. Here we demonstrate that this increase in energy efficiency is due largely to a warmer body temperature. Increases in temperature result in an exponential increase in energy efficiency for single action potentials by increasing the rate of Na+ channel inactivation, resulting in a marked reduction in overlap of the inward Na+, and outward K+, currents and a shortening of action potential duration. This increase in single spike efficiency is, however, counterbalanced by a temperature-dependent decrease in the amplitude and duration of the spike afterhyperpolarization, resulting in a nonlinear increase in the spike firing rate, particularly at temperatures above approximately 35°C. Interestingly, the total energy cost, as measured by the multiplication of total Na+ entry per spike and average firing rate in response to a constant input, reaches a global minimum between 37–42°C. Our results indicate that increases in temperature result in an unexpected increase in energy efficiency, especially near normal body temperature, thus allowing the brain to utilize an energy efficient neural code. PMID:22511855

Words vs. deeds: Americans' energy concerns and implementation of green energy policies

NASA Astrophysics Data System (ADS)

Brinker, Garrett C.

As the effects of climate change become increasingly clear, nations, international organizations, and corporations are working together to help mitigate these negative effects before they become irreversible. The United States, as the world's largest emitter per capita, has a responsibility to take quick and decisive action to decrease carbon emissions. And while an overwhelming majority of Americans believe that green energy policies are the right step forward, few have taken meaningful steps to actually implement these policies. Green and energy efficient technologies such as hybrid and electric cars, smart meters, and solar panels---technologies that would reduce our carbon footprint---are currently purchased or used by very few households. There is a clear gap between our words and deeds. Using the University of Texas at Austin Energy Poll dataset, this paper examines this gap and analyzes how income may influence what people say, versus how they act, seeking to better understand how income influences peoples' energy behaviors. Previous literature suggests that income has proven to be an inconsistent measure of concern for energy use. Through two OLS models, this paper finds that income is negatively correlated with Americans' concern for energy usage, while finding that there is a positive correlation between income and Americans' implementation of energy efficient technologies. Further, there is a nonlinear relationship between income groups and how Americans both think about their energy usage and actually implement more energy efficient measures.

The influence of mechanical gear on the efficiency of small hydropower

NASA Astrophysics Data System (ADS)

Ferenc, Zbigniew; Sambor, Aleksandra

2017-11-01

Pursuant to the "Strategy of development of renewable energy", an increase in the share of renewable energy sources in the national fuel-energy balance up to 14% by 2020 is planned in the structure of usage of primary energy carriers. The change in the participation of the clean energy in the energy balance may be done not only by the erection of new and renovation of the already existing plants, but also through an improvement of their energetic efficiency. The study presents the influence of the mechanical gear used on the quantity of energy produced by a small hydropower on the basis of SHP Rzepcze in Opole province in 2005-2010. The primary kinematic system was composed of a Francis turbine of a vertical axis, a toothed intersecting axis gear of 1:1 ratio, a belt gear of a double ratio. After a modernization the system was simplified by means of reducing the intersecting axis gear and the double ratio of the belt gear. The new kinematic system utilized a single-ratio belt gear of a vertical axis. After the kinematic system was rearranged, a significant improvement of efficiency of the small hydropower was concluded, which translates into an increase of the amount of energy produced.

Quantum-Carnot engine for particle confined to cubic potential

NASA Astrophysics Data System (ADS)

Sutantyo, Trengginas Eka P.; Belfaqih, Idrus H.; Prayitno, T. B.

2015-09-01

Carnot cycle consists of isothermal and adiabatic processes which are reversible. Using analogy in quantum mechanics, these processes can be well explained by replacing variables in classical process with a quantum system. Quantum system which is shown in this paper is a particle that moves under the influence of a cubic potential which is restricted only to the state of the two energy levels. At the end, the efficiency of the system is shown as a function of the width ratio between the initial conditions and the farthest wall while expanding. Furthermore, the system efficiency will be considered 1D and 2D cases. The providing efficiencies are different due to the influence of the degeneration of energy and the degrees of freedom of the system.

Factors Affecting the Corporate Decision-Making Process of Air Transport Manufacturers

NASA Technical Reports Server (NTRS)

Ollila, R. G.; Hill, J. D.; Noton, B. R.; Duffy, M. A.; Epstein, M. M.

1976-01-01

Fuel economy is a pivotal question influencing the future sale and utilization of commercial aircraft. The NASA Aircraft Energy Efficiency (ACEE) Program Office has a program intended to accelerate the readiness of advanced technologies for energy efficient aircraft. Because the decision to develop a new airframe or engine is a major financial hazard for manufacturers, it is important to know what factors influence the decision making process. A method is described for identifying and ranking individuals and organizations involved at each stage of commercial air transport development, and the barriers that must be overcome in adopting new technologies.

Static vs. mobile sink: The influence of basic parameters on energy efficiency in wireless sensor networks.

PubMed

Khan, Majid I; Gansterer, Wilfried N; Haring, Guenter

2013-05-15

Over the last decade a large number of routing protocols has been designed for achieving energy efficiency in data collecting wireless sensor networks. The drawbacks of using a static sink are well known. It has been argued in the literature that a mobile sink may improve the energy dissipation compared to a static one. Some authors focus on minimizing Emax , the maximum energy dissipation of any single node in the network, while others aim at minimizing Ebar , the average energy dissipation over all nodes. In our paper we take a more holistic view, considering both Emax and Ebar . The main contribution of this paper is to provide a simulation-based analysis of the energy efficiency of WSNs with static and mobile sinks. The focus is on two important configuration parameters: mobility path of the sink and duty cycling value of the nodes. On the one hand, it is well known that in the case of a mobile sink with fixed trajectory the choice of the mobility path influences energy efficiency. On the other hand, in some types of applications sensor nodes spend a rather large fraction of their total lifetime in idle mode, and therefore higher energy efficiency can be achieved by using the concept of reduced duty cycles. In particular, we quantitatively analyze the influence of duty cycling and the mobility radius of the sink as well as their interrelationship in terms of energy consumption for a well-defined model scenario. The analysis starts from general load considerations and is refined into a geometrical model. This model is validated by simulations which are more realistic in terms of duty cycling than previous work. It is illustrated that over all possible configuration scenarios in terms of duty cycle and mobility radius of the sink the energy dissipation in the WSN can vary up to a factor of nine in terms of Emax and up to a factor of 17 in terms of Ebar. It turns out that in general the choice of the duty cycle value is more important for achieving energy efficiency than the choice of the mobility radius of the sink. Moreover, for small values of the duty cycle, a static sink turns out to be optimal in terms of both Emax and Ebar . For larger values of the duty cycle, a mobile sink has advantages over a static sink, especially in terms of Emax . These insights into the basic interrelationship between duty cycle value and mobility radius of a mobile sink are relevant for energy efficient operation of homogeneous WSNs beyond our model scenario.

Energy efficiency analysis of the manipulation process by the industrial objects with the use of Bernoulli gripping devices

NASA Astrophysics Data System (ADS)

Savkiv, Volodymyr; Mykhailyshyn, Roman; Duchon, Frantisek; Mikhalishin, Mykhailo

2017-11-01

The article deals with the topical issue of reducing energy consumption for transportation of industrial objects. The energy efficiency of the process of objects manipulation with the use of the orientation optimization method while gripping with the help of different methods has been studied. The analysis of the influence of the constituent parts of inertial forces, that affect the object of manipulation, on the necessary force characteristics and energy consumption of Bernoulli gripping device has been proposed. The economic efficiency of the use of the optimal orientation of Bernoulli gripping device while transporting the object of manipulation in comparison to the transportation without re-orientation has been proved.

An energy efficient distance-aware routing algorithm with multiple mobile sinks for wireless sensor networks.

PubMed

Wang, Jin; Li, Bin; Xia, Feng; Kim, Chang-Seob; Kim, Jeong-Uk

2014-08-18

Traffic patterns in wireless sensor networks (WSNs) usually follow a many-to-one model. Sensor nodes close to static sinks will deplete their limited energy more rapidly than other sensors, since they will have more data to forward during multihop transmission. This will cause network partition, isolated nodes and much shortened network lifetime. Thus, how to balance energy consumption for sensor nodes is an important research issue. In recent years, exploiting sink mobility technology in WSNs has attracted much research attention because it can not only improve energy efficiency, but prolong network lifetime. In this paper, we propose an energy efficient distance-aware routing algorithm with multiple mobile sink for WSNs, where sink nodes will move with a certain speed along the network boundary to collect monitored data. We study the influence of multiple mobile sink nodes on energy consumption and network lifetime, and we mainly focus on the selection of mobile sink node number and the selection of parking positions, as well as their impact on performance metrics above. We can see that both mobile sink node number and the selection of parking position have important influence on network performance. Simulation results show that our proposed routing algorithm has better performance than traditional routing ones in terms of energy consumption.

An Energy Efficient Distance-Aware Routing Algorithm with Multiple Mobile Sinks for Wireless Sensor Networks

PubMed Central

Wang, Jin; Li, Bin; Xia, Feng; Kim, Chang-Seob; Kim, Jeong-Uk

2014-01-01

Traffic patterns in wireless sensor networks (WSNs) usually follow a many-to-one model. Sensor nodes close to static sinks will deplete their limited energy more rapidly than other sensors, since they will have more data to forward during multihop transmission. This will cause network partition, isolated nodes and much shortened network lifetime. Thus, how to balance energy consumption for sensor nodes is an important research issue. In recent years, exploiting sink mobility technology in WSNs has attracted much research attention because it can not only improve energy efficiency, but prolong network lifetime. In this paper, we propose an energy efficient distance-aware routing algorithm with multiple mobile sink for WSNs, where sink nodes will move with a certain speed along the network boundary to collect monitored data. We study the influence of multiple mobile sink nodes on energy consumption and network lifetime, and we mainly focus on the selection of mobile sink node number and the selection of parking positions, as well as their impact on performance metrics above. We can see that both mobile sink node number and the selection of parking position have important influence on network performance. Simulation results show that our proposed routing algorithm has better performance than traditional routing ones in terms of energy consumption. PMID:25196015

Influence of Energy Input on the Flow Past Hypersonic Aircraft X-43

NASA Astrophysics Data System (ADS)

Khankhasaeva, Ya V.; E Borisov, V.; E Lutsky, A.

2017-02-01

This paper deals with a numerical study of the influence of energy sources on the flow past hypersonic aircraft X-43. Flight mode with M = 6 and angle of attack α = 0°, 4° with energy deposition in areas around various parts of HA was considered. It is shown that energy input in front of the bow of the HA leads to a significant weakening of the bow shock wave and an increase in aerodynamic efficiency of the vehicle. The results of studies on the impact of energy input in the scramjet intake are also presented.

Comfort, Energy Efficiency and Adoption of Personal Cooling Systems in Warm Environments: A Field Experimental Study.

PubMed

He, Yingdong; Li, Nianping; Wang, Xiang; He, Meiling; He, De

2017-11-17

It is well known that personal cooling improves thermal comfort and save energy. This study aims to: (1) compare different personal cooling systems and (2) understand what influences users' willingness to adopt them. A series of experiments on several types of personal cooling systems, which included physical measurements, questionnaires and feedback, was conducted in a real office environment. The obtained results showed that personal cooling improved comfort of participants in warm environments. Then an improved index was proposed and used to compare different types of personal cooling systems in terms of comfort and energy efficiency simultaneously. According to the improved index, desk fans were highly energy-efficient, while the hybrid personal cooling (the combination of radiant cooling desk and desk fan) consumed more energy but showed advantages of extending the comfortable temperature range. Moreover, if personal cooling was free, most participants were willing to adopt it and the effectiveness was the main factor influencing their willingness, whereas if participants had to pay, they probably refused to adopt it due to the cost and the availability of conventional air conditioners. Thus, providing effective and free personal cooling systems should be regarded as a better way for its wider application.

Research on the influencing factors of reverse logistics carbon footprint under sustainable development.

PubMed

Sun, Qiang

2017-10-01

With the concerns of ecological and circular economy along with sustainable development, reverse logistics has attracted the attention of enterprise. How to achieve sustainable development of reverse logistics has important practical significance of enhancing low carbon competitiveness. In this paper, the system boundary of reverse logistics carbon footprint is presented. Following the measurement of reverse logistics carbon footprint and reverse logistics carbon capacity is provided. The influencing factors of reverse logistics carbon footprint are classified into five parts such as intensity of reverse logistics, energy structure, energy efficiency, reverse logistics output, and product remanufacturing rate. The quantitative research methodology using ADF test, Johansen co-integration test, and impulse response is utilized to interpret the relationship between reverse logistics carbon footprint and the influencing factors more accurately. This research finds that energy efficiency, energy structure, and product remanufacturing rate are more capable of inhibiting reverse logistics carbon footprint. The statistical approaches will help practitioners in this field to structure their reverse logistics activities and also help academics in developing better decision models to reduce reverse logistics carbon footprint.

Maintaining energy efficiency in the deregulated electricity market

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aho-Mantila, J.

1995-12-31

The positive attitudes of Finns to energy saving are influenced by the view that results are easily attained. The propagated saving measures - like efficiency enhancement in lighting by CFL`s - are not considered to be any remarkable nuisance in one`s everyday living. Normal, necessary everyday energy use is further not felt to be any energy wasting. A kind of simple {open_quotes}I would not bother{close_quotes} or feeling of convenience is found to be the main reason to explain why energy conservation doesn`t take wind under wings. Information campaigns and voluntary actions are the preferred means instead of energy price increasesmore » how people like to be guided in the future. The transition to competitive electricity market is likely to reduce the electricity sellers ability to actively promote energy efficiency - unless their customers would like to pay for it in a way or other.« less

Optimal size of stochastic Hodgkin-Huxley neuronal systems for maximal energy efficiency in coding pulse signals

NASA Astrophysics Data System (ADS)

Yu, Lianchun; Liu, Liwei

2014-03-01

The generation and conduction of action potentials (APs) represents a fundamental means of communication in the nervous system and is a metabolically expensive process. In this paper, we investigate the energy efficiency of neural systems in transferring pulse signals with APs. By analytically solving a bistable neuron model that mimics the AP generation with a particle crossing the barrier of a double well, we find the optimal number of ion channels that maximizes the energy efficiency of a neuron. We also investigate the energy efficiency of a neuron population in which the input pulse signals are represented with synchronized spikes and read out with a downstream coincidence detector neuron. We find an optimal number of neurons in neuron population, as well as the number of ion channels in each neuron that maximizes the energy efficiency. The energy efficiency also depends on the characters of the input signals, e.g., the pulse strength and the interpulse intervals. These results are confirmed by computer simulation of the stochastic Hodgkin-Huxley model with a detailed description of the ion channel random gating. We argue that the tradeoff between signal transmission reliability and energy cost may influence the size of the neural systems when energy use is constrained.

Optimal size of stochastic Hodgkin-Huxley neuronal systems for maximal energy efficiency in coding pulse signals.

PubMed

Yu, Lianchun; Liu, Liwei

2014-03-01

The generation and conduction of action potentials (APs) represents a fundamental means of communication in the nervous system and is a metabolically expensive process. In this paper, we investigate the energy efficiency of neural systems in transferring pulse signals with APs. By analytically solving a bistable neuron model that mimics the AP generation with a particle crossing the barrier of a double well, we find the optimal number of ion channels that maximizes the energy efficiency of a neuron. We also investigate the energy efficiency of a neuron population in which the input pulse signals are represented with synchronized spikes and read out with a downstream coincidence detector neuron. We find an optimal number of neurons in neuron population, as well as the number of ion channels in each neuron that maximizes the energy efficiency. The energy efficiency also depends on the characters of the input signals, e.g., the pulse strength and the interpulse intervals. These results are confirmed by computer simulation of the stochastic Hodgkin-Huxley model with a detailed description of the ion channel random gating. We argue that the tradeoff between signal transmission reliability and energy cost may influence the size of the neural systems when energy use is constrained.

A critical review on factors influencing fermentative hydrogen production.

PubMed

Kothari, Richa; Kumar, Virendra; Pathak, Vinayak V; Ahmad, Shamshad; Aoyi, Ochieng; Tyagi, V V

2017-03-01

Biohydrogen production by dark fermentation of different waste materials is a promising approach to produce bio-energy in terms of renewable energy exploration. This communication has reviewed various influencing factors of dark fermentation process with detailed account of determinants in biohydrogen production. It has also focused on different factors such as improved bacterial strain, reactor design, metabolic engineering and two stage processes to enhance the bioenergy productivity from substrate. The study also suggest that complete utilization of substrates for biological hydrogen production requires the concentrated research and development for efficient functioning of microorganism with integrated application for energy production and bioremediation. Various studies have been taken into account here, to show the comparative efficiency of different substrates and operating conditions with inhibitory factors and pretreatment option for biohydrogen production. The study reveals that an extensive research is needed to observe field efficiency of process using low cost substrates and integration of dark and photo fermentation process. Integrated approach of fermentation process will surely compete with conventional hydrogen process and replace it completely in future.

The Role of Values, Moral Norms, and Descriptive Norms in Building Occupant Responses to an Energy-Efficiency Pilot Program and to Framing of Related Messages

ERIC Educational Resources Information Center

Arpan, Laura M.; Barooah, Prabir; Subramany, Rahul

2015-01-01

This study examined building occupants' responses associated with an occupant-based energy-efficiency pilot in a university building. The influence of occupants' values and norms as well as effects of two educational message frames (descriptive vs. moral norms cues) on program support were tested. Occupants' personal moral norm to conserve energy…

Influence of Voltage Rise Time for Oxidation Treatment of NO in Simulated Exhausted Gas by Polarity-Reversed Pulse Discharge

NASA Astrophysics Data System (ADS)

Shinmoto, Kazuya; Kadowaki, Kazunori; Nishimoto, Sakae; Kitani, Isamu

This paper describes experimental study on NO removal from a simulated exhausted-gas using repetitive surface discharge on a glass barrier subjected to polarity-reversed voltage pulses. The very fast polarity-reversal with a rise time of 20ns is caused by direct grounding of a charged coaxial cable of 10m in length. Influence of voltage rise time on energy efficiency for NO removal is studied. Results of NO removal using a barrier-type plasma reactor with screw-plane electrode system indicates that the energy efficiency for the very fast polarity reversal caused by direct grounding becomes higher than that for the slower polarity reversal caused by grounding through an inductor at the cable end. The energy efficiency for the direct grounding is about 80g/kWh for 50% NO removal ratio and is about 60g/kWh for 100% NO removal ratio. Very intense discharge light is observed at the initial time of 10ns for the fast polarity reversal, whereas the intensity in the initial discharge light for the slower polarity reversal is relatively small. To confirm the effectiveness of the polarity-reversed pulse application, comparison of the energy efficiency between the polarity-reversed voltage pulse and ac 60Hz voltage will be presented.

Wideband piezoelectric energy harvester for low-frequency application with plucking mechanism

NASA Astrophysics Data System (ADS)

Hiraki, Yasuhiro; Masuda, Arata; Ikeda, Naoto; Katsumura, Hidenori; Kagata, Hiroshi; Okumura, Hidenori

2015-04-01

Wireless sensor networks need energy harvesting from vibrational environment for their power supply. The conventional resonance type vibration energy harvesters, however, are not always effective for low frequency application. The purpose of this paper is to propose a high efficiency energy harvester for low frequency application by utilizing plucking and SSHI techniques, and to investigate the effects of applying those techniques in terms of the energy harvesting efficiency. First, we derived an approximate formulation of energy harvesting efficiency of the plucking device by theoretical analysis. Next, it was confirmed that the improved efficiency agreed with numerical and experimental results. Also, a parallel SSHI, a switching circuit technique to improve the performance of the harvester was introduced and examined by numerical simulations and experiments. Contrary to the simulated results in which the efficiency was improved from 13.1% to 22.6% by introducing the SSHI circuit, the efficiency obtained in the experiment was only 7.43%. This would due to the internal resistance of the inductors and photo MOS relays on the switching circuit and the simulation including this factor revealed large negative influence of it. This result suggested that the reduction of the switching resistance was significantly important to the implementation of SSHI.

Leveraging Human-environment Systems in Residential Buildings for Aggregate Energy Efficiency and Sustainability

NASA Astrophysics Data System (ADS)

Xu, Xiaoqi

Reducing the energy consumed in the built environment is a key objective in many sustainability initiatives. Existing energy saving methods have consisted of physical interventions to buildings and/or behavioral modifications of occupants. However, such methods may not only suffer from their own disadvantages, e.g. high cost and transient effect, but also lose aggregate energy saving potential due to the oftentimes-associated single-building-focused view and an isolated examination of occupant behaviors. This dissertation attempts to overcome the limitations of traditional energy saving research and practical approaches, and enhance residential building energy efficiency and sustainability by proposing innovative energy strategies from a holistic perspective of the aggregate human-environment systems. This holistic perspective features: (1) viewing buildings as mutual influences in the built environment, (2) leveraging both the individual and contextualized social aspects of occupant behaviors, and (3) incorporating interactions between the built environment and human behaviors. First, I integrate three interlinked components: buildings, residents, and the surrounding neighborhood, and quantify the potential energy savings to be gained from renovating buildings at the inter-building level and leveraging neighborhood-contextualized occupant social networks. Following the confirmation of both the inter-building effect among buildings and occupants' interpersonal influence on energy conservation, I extend the research further by examining the synergy that may exist at the intersection between these "engineered" building networks and "social" peer networks, focusing specifically on the additional energy saving potential that could result from interactions between the two components. Finally, I seek to reach an alignment of the human and building environment subsystems by matching the thermostat preferences of each household with the thermal conditions within their apartment, and develop the Energy Saving Alignment Strategy to be considered in public housing assignment policy. This strategy and the inter-building level energy management strategies developed in my preceding research possess large-scale cost-effectiveness and may engender long-lasting influence compared with existing energy saving approaches. Building from the holistic framework of coupled human-environment systems, the findings of this research will advance knowledge of energy efficiency in the built environment and lead to the development of novel strategies to conserve energy in residential buildings.

Stable continuous-wave single-frequency Nd:YAG blue laser at 473 nm considering the influence of the energy-transfer upconversion.

PubMed

Wang, Yaoting; Liu, Jianli; Liu, Qin; Li, Yuanji; Zhang, Kuanshou

2010-06-07

We report a continuous-wave (cw) single frequency Nd:YAG blue laser at 473 nm end-pumped by a laser diode. A ring laser resonator was designed, the frequency doubling efficiency and the length of nonlinear crystal were optimized based on the investigation of the influence of the frequency doubling efficiency on the thermal lensing effect induced by energy-transfer upconversion. By intracavity frequency doubling with PPKTP crystal, an output power of 1 W all-solid-state cw blue laser of single-frequency operation was achieved. The stability of the blue output power was better than +/- 1.8% in the given four hours.

Carbon-free hydrogen production from low rank coal

NASA Astrophysics Data System (ADS)

Aziz, Muhammad; Oda, Takuya; Kashiwagi, Takao

2018-02-01

Novel carbon-free integrated system of hydrogen production and storage from low rank coal is proposed and evaluated. To measure the optimum energy efficiency, two different systems employing different chemical looping technologies are modeled. The first integrated system consists of coal drying, gasification, syngas chemical looping, and hydrogenation. On the other hand, the second system combines coal drying, coal direct chemical looping, and hydrogenation. In addition, in order to cover the consumed electricity and recover the energy, combined cycle is adopted as addition module for power generation. The objective of the study is to find the best system having the highest performance in terms of total energy efficiency, including hydrogen production efficiency and power generation efficiency. To achieve a thorough energy/heat circulation throughout each module and the whole integrated system, enhanced process integration technology is employed. It basically incorporates two core basic technologies: exergy recovery and process integration. Several operating parameters including target moisture content in drying module, operating pressure in chemical looping module, are observed in terms of their influence to energy efficiency. From process modeling and calculation, two integrated systems can realize high total energy efficiency, higher than 60%. However, the system employing coal direct chemical looping represents higher energy efficiency, including hydrogen production and power generation, which is about 83%. In addition, optimum target moisture content in drying and operating pressure in chemical looping also have been defined.

Simultaneous Enhancement of Efficiency and Stability of Phosphorescent OLEDs Based on Efficient Förster Energy Transfer from Interface Exciplex.

PubMed

Zhang, Dongdong; Cai, Minghan; Zhang, Yunge; Bin, Zhengyang; Zhang, Deqiang; Duan, Lian

2016-02-17

Exciplex forming cohosts have been widely adopted in phosphorescent organic light-emitting diodes (PHOLEDs), achieving high efficiency with low roll-off and low driving voltage. However, the influence of the exciplex-forming hosts on the lifetimes of the devices, which is one of the essential characteristics, remains unclear. Here, we compare the influence of the bulk exciplex and interface exciplex on the performances of the devices, demonstrating highly efficient orange PHOLEDs with long lifetime at low dopant concentration by efficient Förster energy transfer from the interface exciplex. A bipolar host, (3'-(4,6-diphenyl-1,3,5-triazin-2-yl)-(1,1'-biphenyl)-3-yl)-9-carbazole (CzTrz), was adopted to combine with a donor molecule, tris(4-(9H-carbazol-9-yl)phenyl)amine (TCTA), to form exciplex. Devices with energy transfer from the interface exciplex achieve lifetime almost 2 orders of magnitude higher than the ones based on bulk exciplex as the host by avoiding the formation of the donor excited states. Moreover, a highest EQE of 27% was obtained at the dopant concentration as low as 3 wt % for a device with interface exciplex, which is favorable for reducing the cost of fabrication. We believe that our work may shed light on future development of ideal OLEDs with high efficiency, long-lifetime, low roll-off and low cost simultaneously.

Efficiency of photochemical stages of photosynthesis in purple bacteria (a critical survey).

PubMed

Borisov, A Yu

2014-03-01

Based on currently available data, the energy transfer efficiency in the successive photophysical and photochemical stages has been analyzed for purple bacteria. This analysis covers the stages starting from migration of the light-induced electronic excitations from the bulk antenna pigments to the reaction centers up to irreversible stage of the electron transport along the transmembrane chain of cofactors-carriers. Some natural factors are revealed that significantly increase the rates of efficient processes in these stages. The influence on their efficiency by the "bottleneck" in the energy migration chain is established. The overall quantum yield of photosynthesis in these stages is determined.

Leveraging organizational dynamics in buildings to change behavior

NASA Astrophysics Data System (ADS)

Hewitt, Elizabeth L.

Buildings may be stationary, but they are not static; they are dynamic and active collectives of agents and actors, and play an important cultural and social role in shaping norms and influencing outcomes in the built environment. This research develops and applies a unique framework that conceptualizes the urban multifamily residential building as an organization, and seeks to use this lens to better understand the role of organizational characteristics in influencing energy efficiency in buildings. This work finds that an organizational analogy is a fruitful approach for understanding buildings, and that buildings in many ways can and do function successfully as organizations. In particular, eight organizational characteristics are explored here that extend well to buildings. These eight organizational characteristics are also explored more deeply to support an argument that some buildings have an organizational advantage that well positions them to undertake energy efficiency initiatives. One organizational characteristic -- the ownership type of the building -- is determined to be particularly important in driving energy outcomes in multifamily buildings in New York City. In particular, it was found that cooperative buildings in the New York City housing market consume less energy citywide than other types of multifamily properties, holding all else equal. Conversely, it was also found that rental buildings tend to consume more energy citywide. Subsequent qualitative case study work in a small Brooklyn cooperative building offers a deeper understanding of organizational decentralization and its role in driving decision-making and outcomes in the building. Additional comparative work in two rental properties -- one high-income and one low-income -- adds additional context and understanding to economic considerations such as the influence of income in overriding centralized efforts to operate the building efficiently. Ultimately, this research develops an analogy of buildings-as-organizations -- a conceptual framework -- to better understand tangible built space. It posits that all buildings can function as organizations, and extends this framework to the urban multifamily building to advance knowledge of energy efficiency.

Using qualitative methods to understand non-technological aspects of domestic energy efficiency

NASA Astrophysics Data System (ADS)

Ambrose, Aimee Rebecca

The overall aim of the collected published works is to investigate how different policy interventions in the field of energy efficiency (including zero carbon homes, low carbon heat networks, and domestic energy efficiency schemes) are experienced and made sense of by a range of key actors. A further aim is to understand these interventions in the context of existing theories within the field of domestic energy efficiency including socio-technical theory and Actor Network Theory. More specifically, this research advances existing knowledge in the following areas: The nature of the socio-technical challenges encountered in the introduction of more energy efficient buildings, and the importance of achieving a balance between socially acceptable and technically optimal environments. (Papers 2, 3, 4, 6 and 8). The value of qualitative research in gaining a more nuanced understanding of our relationship with the home and the implications of this for domestic energy efficiency interventions and the design of low energy buildings (all papers). The influence of tenure as determinant of access to a more energy efficient home and in particular, the stubborn and complex barriers to achieving higher standards of energy performance within the private rented sector. (Papers 1, 2, 3 and 4). The significance of identity, setting and notions of home in the context of domestic energy efficiency interventions. (Papers 1 and 4). As these themes suggest, this PhD is not just concerned with carbon reduction and energy saving as technical objects, but as a way of life. More specifically, it considers the interactions between the two and contends that technical or policy instruments, no matter how sophisticated, cannot succeed if they are not compatible with our ways of life (and ways of doing businesss) or if our ways of life cannot be reasonably adapted to acoomodate them.

Motivating the Skeptical and Unconcerned: Considering Values, Worldviews, and Norms When Planning Messages Encouraging Energy Conservation and Efficiency Behaviors

ERIC Educational Resources Information Center

Arpan, Laura M.; Opel, Andrew R.; Lu, Jia

2013-01-01

The current study examined the association of personal values or worldviews with individual motivations for reduced energy use and energy-use-related risk perceptions. We also investigated how perceptions of others' energy use influenced motivation to reduce use among those with high, versus low, risk perceptions. The perception that others were…

Research on efficiency evaluation model of integrated energy system based on hybrid multi-attribute decision-making.

PubMed

Li, Yan

2017-05-25

The efficiency evaluation model of integrated energy system, involving many influencing factors, and the attribute values are heterogeneous and non-deterministic, usually cannot give specific numerical or accurate probability distribution characteristics, making the final evaluation result deviation. According to the characteristics of the integrated energy system, a hybrid multi-attribute decision-making model is constructed. The evaluation model considers the decision maker's risk preference. In the evaluation of the efficiency of the integrated energy system, the evaluation value of some evaluation indexes is linguistic value, or the evaluation value of the evaluation experts is not consistent. These reasons lead to ambiguity in the decision information, usually in the form of uncertain linguistic values and numerical interval values. In this paper, the risk preference of decision maker is considered when constructing the evaluation model. Interval-valued multiple-attribute decision-making method and fuzzy linguistic multiple-attribute decision-making model are proposed. Finally, the mathematical model of efficiency evaluation of integrated energy system is constructed.

Eco Assist Techniques through Real-time Monitoring of BEV Energy Usage Efficiency

PubMed Central

Kim, Younsun; Lee, Ingeol; Kang, Sungho

2015-01-01

Energy efficiency enhancement has become an increasingly important issue for battery electric vehicles. Even if it can be improved in many ways, the driver’s driving pattern strongly influences the battery energy consumption of a vehicle. In this paper, eco assist techniques to simply implement an energy-efficient driving assistant system are introduced, including eco guide, eco control and eco monitoring methods. The eco guide is provided to control the vehicle speed and accelerator pedal stroke, and eco control is suggested to limit the output power of the battery. For eco monitoring, the eco indicator and eco report are suggested to teach eco-friendly driving habits. The vehicle test, which is done in four ways, consists of federal test procedure (FTP)-75, new european driving cycle (NEDC), city and highway cycles, and visual feedback with audible warnings is provided to attract the driver’s voluntary participation. The vehicle test result shows that the energy usage efficiency can be increased up to 19.41%. PMID:26121611

Development of a Prototype Low-Voltage Electron Beam Freeform Fabrication System

NASA Technical Reports Server (NTRS)

Watson, J. K.; Taminger, K. M.; Hafley, R. A.; Petersen, D. D.

2002-01-01

NASA's Langley Research Center and Johnson Space Center are developing a solid freeform fabrication system utilizing an electron beam energy source and wire feedstock. This system will serve as a testbed for exploring the influence of gravitational acceleration on the deposition process and will be a simplified prototype for future systems that may be deployed during long-duration space missions for assembly, fabrication, and production of structural and mechanical replacement components. Critical attributes for this system are compactness, minimal mass, efficiency in use of feedstock material, energy use efficiency, and safety. The use of a low-voltage (less than 15kV) electron beam energy source will reduce radiation so that massive shielding is not required to protect adjacent personnel. Feedstock efficiency will be optimized by use of wire, and energy use efficiency will be achieved by use of the electron beam energy source. This system will be evaluated in a microgravity environment using the NASA KC-135A aircraft.

Analysis of the impact path on factors of China's energy-related CO2 emissions: a path analysis with latent variables.

PubMed

Chen, Wenhui; Lei, Yalin

2017-02-01

Identifying the impact path on factors of CO 2 emissions is crucial for the government to take effective measures to reduce carbon emissions. The most existing research focuses on the total influence of factors on CO 2 emissions without differentiating between the direct and indirect influence. Moreover, scholars have addressed the relationships among energy consumption, economic growth, and CO 2 emissions rather than estimating all the causal relationships simultaneously. To fill this research gaps and explore overall driving factors' influence mechanism on CO 2 emissions, this paper utilizes a path analysis model with latent variables (PA-LV) to estimate the direct and indirect effect of factors on China's energy-related carbon emissions and to investigate the causal relationships among variables. Three key findings emanate from the analysis: (1) The change in the economic growth pattern inhibits the growth rate of CO 2 emissions by reducing the energy intensity; (2) adjustment of industrial structure contributes to energy conservation and CO 2 emission reduction by raising the proportion of the tertiary industry; and (3) the growth of CO 2 emissions impacts energy consumption and energy intensity negatively, which results in a negative impact indirectly on itself. To further control CO 2 emissions, the Chinese government should (1) adjust the industrial structure and actively develop its tertiary industry to improve energy efficiency and develop low-carbon economy, (2) optimize population shifts to avoid excessive population growth and reduce energy consumption, and (3) promote urbanization steadily to avoid high energy consumption and low energy efficiency.

Energy saving technologies of the decentralized ventilation of buildings

NASA Astrophysics Data System (ADS)

Mansurov, R. Sh; Rafalskaya, T. A.

2017-11-01

The growing aspiration to energy saving and efficiency of energy leads to necessity to build tight enough buildings. As a result of this the quantity of infiltration air appears insufficient for realization of necessary air exchange in. One of decisions of the given problem is development and application for ventilation of premises of the decentralized forced-air and exhaust systems (DFAES) with recuperative or regenerative heat-exchangers. For an estimation of efficiency of DFAES following basic parameters have been certain: factor of energy saving; factor of efficiency of energy; factor of a heat transfer; factor of an effective utilization of a surface of heat exchange. Were estimated temperature of forced air; actual speed of an air jet on an entrance in a served zone; actual noise level; the charge of external air. Tests of DFAES were spent in natural conditions at which DFAES influenced all set of factors both an external climate, and an internal microclimate of a premise, and also the arrangement on a wind side or behind wind side of a building, influence of surrounding building, fluctuation of temperature of external air is considered. Proceeding from results and the analysis of the lead researches recommendations have been developed for development and manufacture of new sample of DFAES.

Comfort, Energy Efficiency and Adoption of Personal Cooling Systems in Warm Environments: A Field Experimental Study

PubMed Central

He, Yingdong; Li, Nianping; Wang, Xiang; He, Meiling; He, De

2017-01-01

It is well known that personal cooling improves thermal comfort and save energy. This study aims to: (1) compare different personal cooling systems and (2) understand what influences users’ willingness to adopt them. A series of experiments on several types of personal cooling systems, which included physical measurements, questionnaires and feedback, was conducted in a real office environment. The obtained results showed that personal cooling improved comfort of participants in warm environments. Then an improved index was proposed and used to compare different types of personal cooling systems in terms of comfort and energy efficiency simultaneously. According to the improved index, desk fans were highly energy-efficient, while the hybrid personal cooling (the combination of radiant cooling desk and desk fan) consumed more energy but showed advantages of extending the comfortable temperature range. Moreover, if personal cooling was free, most participants were willing to adopt it and the effectiveness was the main factor influencing their willingness, whereas if participants had to pay, they probably refused to adopt it due to the cost and the availability of conventional air conditioners. Thus, providing effective and free personal cooling systems should be regarded as a better way for its wider application. PMID:29149078

Transmission of energy-saving efficiency from obese parents to their offspring: the Korean National Health and Nutrition Examination Survey 2007-2011.

PubMed

Kim, Y; Kim, H; Hong, Y-C

2016-04-01

Concerns of a growing obesity epidemic have increased since the association between obesity in parents and that in offspring was reported. However, the evidence regarding whether the energy-saving efficiency of obese parents is conveyed to their offspring and the duration of the expression of such transmitted efficiency is limited. We included 7647 matching sets of parent-offspring trios from South Korea. Multiple linear regression models were performed to estimate the energy-saving efficiency, as assessed by the associations between energy intake and obesity-related indices (waist-to-height ratio, waist circumference and body mass index z-score), and to compare the energy-saving efficiency of offspring of obese and non-obese parents. All analyses were based on a complex sample design and were stratified by gender and age. We identified a parental influence on obesity, that is, the more obese the parent, the higher the obesity-related indices of their offspring, in both genders and all age groups. The energy-saving efficiency of child offspring was highest when both parents were obese and lowest when both were non-obese; this difference was significant (P<0.05) with regard to the energy-saving efficiency of all types of intake studied, except fat. However, the energy-saving efficiency of obese and non-obese parents did not differ when their offspring were adolescents and adults. The critical window for transmission of energy-saving efficiency is limited to childhood. These findings suggest that children of obese parents should be more emphatically advised to maintain a balanced diet and to engage in regular physical activity.

Placement and efficiency effects on radiative forcing of solar installations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burg, Brian R.; Ruch, Patrick; Paredes, Stephan

2015-09-28

The promise for harnessing solar energy being hampered by cost, triggered efforts to reduce them. As a consequence low-efficiency, low-cost photovoltaics (PV) panels prevail. Conversely, in the traditional energy sector efficiency is extremely important due to the direct costs associated to fuels. This also affects solar energy due to the radiative forcing caused by the dark solar panels. In this paper we extend the concept of energy payback time by including the effect of albedo change, which gives a better assessment of the system sustainability. We present an analysis on the short and medium term climate forcing effects of differentmore » solar collectors in Riyadh, Saudi Arabia and demonstrate that efficiency is important to reduce the collector area and cost. This also influences the embodied energy and the global warming potential. We show that a placement of a high concentration photovoltaic thermal solar power station outside of the city using a district cooling system has a double beneficial effect since it improves the solar conversion efficiency and reduces the energy demand for cooling in the city. We also explain the mechanisms of the current economic development of solar technologies and anticipate changes.« less

Influence of the nozzle angle on refrigeration performance of a gas wave refrigerator

NASA Astrophysics Data System (ADS)

Liu, P.; Zhu, Y.; Wang, H.; Zhu, C.; Zou, J.; Wu, J.; Hu, D.

2017-05-01

A gas wave refrigerator (GWR) is a novel refrigerating device that refrigerates a medium by shock waves and expansion waves generated by gas pressure energy. In a typical GWR, the injection energy losses between the nozzle and the expansion tube are essential factors which influence the refrigeration efficiency. In this study, numerical simulations are used to analyze the underlying mechanism of the injection energy losses. The results of simulations show that the vortex loss, mixing energy loss, and oblique shock wave reflection loss are the main factors contributing to the injection energy losses in the expansion tube. Furthermore, the jet angle of the gas is found to dominate the injection energy losses. Therefore, the optimum jet angle is theoretically calculated based on the velocity triangle method. The value of the optimum jet angle is found to be 4^{circ }, 8^{circ }, and 12^{circ } when the refrigeration efficiency is the first-order, second-order, and third-order maximum value over all working ranges of jet frequency, respectively. Finally, a series of experiments are conducted with the jet angle ranging from -4^{circ } to 12^{circ } at a constant expansion ratio. The results indicate the optimal jet angle obtained by the experiments is in good agreement with the calculated value. The isentropic refrigeration efficiency increased by about 4 % after the jet angle was optimized.

Global Energy Trade and the Joint Expeditionary Force: Supporting Friends and Influencing Others on the New Silk Road

DTIC Science & Technology

2009-05-27

of old. In general, world energy consumption is discussed in five categories: coal, oil, gas, hydro- electric , and nuclear. The aforementioned...price volatility brought about by demography, geology, and geopolitics. The costs of gas for cars and SUVs, diesel fuel that allow truck drivers...efficient car that was three times more fuel efficient than anything currently in production by 2004.12 Nevertheless, amid a global economic slowdown

Energy-Efficient Control with Harvesting Predictions for Solar-Powered Wireless Sensor Networks.

PubMed

Zou, Tengyue; Lin, Shouying; Feng, Qijie; Chen, Yanlian

2016-01-04

Wireless sensor networks equipped with rechargeable batteries are useful for outdoor environmental monitoring. However, the severe energy constraints of the sensor nodes present major challenges for long-term applications. To achieve sustainability, solar cells can be used to acquire energy from the environment. Unfortunately, the energy supplied by the harvesting system is generally intermittent and considerably influenced by the weather. To improve the energy efficiency and extend the lifetime of the networks, we propose algorithms for harvested energy prediction using environmental shadow detection. Thus, the sensor nodes can adjust their scheduling plans accordingly to best suit their energy production and residual battery levels. Furthermore, we introduce clustering and routing selection methods to optimize the data transmission, and a Bayesian network is used for warning notifications of bottlenecks along the path. The entire system is implemented on a real-time Texas Instruments CC2530 embedded platform, and the experimental results indicate that these mechanisms sustain the networks' activities in an uninterrupted and efficient manner.

Energy-Efficient Control with Harvesting Predictions for Solar-Powered Wireless Sensor Networks

PubMed Central

Zou, Tengyue; Lin, Shouying; Feng, Qijie; Chen, Yanlian

2016-01-01

Wireless sensor networks equipped with rechargeable batteries are useful for outdoor environmental monitoring. However, the severe energy constraints of the sensor nodes present major challenges for long-term applications. To achieve sustainability, solar cells can be used to acquire energy from the environment. Unfortunately, the energy supplied by the harvesting system is generally intermittent and considerably influenced by the weather. To improve the energy efficiency and extend the lifetime of the networks, we propose algorithms for harvested energy prediction using environmental shadow detection. Thus, the sensor nodes can adjust their scheduling plans accordingly to best suit their energy production and residual battery levels. Furthermore, we introduce clustering and routing selection methods to optimize the data transmission, and a Bayesian network is used for warning notifications of bottlenecks along the path. The entire system is implemented on a real-time Texas Instruments CC2530 embedded platform, and the experimental results indicate that these mechanisms sustain the networks’ activities in an uninterrupted and efficient manner. PMID:26742042

Impact of the circulation system on the energy balance of the building

NASA Astrophysics Data System (ADS)

Polarczyk, Iwona; Fijewski, Michał

2017-11-01

The efficiency of the hot water system is one of the factors necessary to determine the overall efficiency of the building. From the calculative point of view, it is easy to make. The article presents how working of the circulation system has an influence on the efficiency of domestic hot water system. The differences in the results was presented and based on calculations of various methods, the measurements results was also taken into account. The attention was especially paid to the possibility of using ultrasonic flowmeter for measuring the flow and energy.

Performance analysis of hybrid vibrational energy harvesters with experimental verification

NASA Astrophysics Data System (ADS)

Sriramdas, Rammohan; Pratap, Rudra

2018-07-01

In the present work, performance indices for a hybrid energy harvester (HEH) that is composed of piezoelectric and electrodynamic or electromagnetic mechanisms of energy conversion are analyzed. Performance of a HEH is defined in terms of Q-normalized power factor and efficiency of conversion. They are observed to acutely depend on coupling strength or figures of merit in both piezoelectric and electrodynamic domains. The influence of figures of merit on the Q-normalized power factor, and the limits of conversion efficiency are explored. Based on the studies, a suitable range for figures of merit that would maximize both Q-normalized power factor and conversion efficiency in hybrid harvesters is proposed. The proposed idea is verified experimentally for the appropriate values of figures of merit and efficiencies by fabricating and testing four experimental models of the HEHs.

Genome wide association analyses based on a multiple trait approach for modeling feed efficiency

USDA-ARS?s Scientific Manuscript database

Genome wide association (GWA) of feed efficiency (FE) could help target important genomic regions influencing FE. Data provided by an international dairy FE research consortium consisted of phenotypic records on dry matter intakes (DMI), milk energy (MILKE), and metabolic body weight (MBW) on 6,937 ...

Design of multi-energy Helds coupling testing system of vertical axis wind power system

NASA Astrophysics Data System (ADS)

Chen, Q.; Yang, Z. X.; Li, G. S.; Song, L.; Ma, C.

2016-08-01

The conversion efficiency of wind energy is the focus of researches and concerns as one of the renewable energy. The present methods of enhancing the conversion efficiency are mostly improving the wind rotor structure, optimizing the generator parameters and energy storage controller and so on. Because the conversion process involves in energy conversion of multi-energy fields such as wind energy, mechanical energy and electrical energy, the coupling effect between them will influence the overall conversion efficiency. In this paper, using system integration analysis technology, a testing system based on multi-energy field coupling (MEFC) of vertical axis wind power system is proposed. When the maximum efficiency of wind rotor is satisfied, it can match to the generator function parameters according to the output performance of wind rotor. The voltage controller can transform the unstable electric power to the battery on the basis of optimizing the parameters such as charging times, charging voltage. Through the communication connection and regulation of the upper computer system (UCS), it can make the coupling parameters configure to an optimal state, and it improves the overall conversion efficiency. This method can test the whole wind turbine (WT) performance systematically and evaluate the design parameters effectively. It not only provides a testing method for system structure design and parameter optimization of wind rotor, generator and voltage controller, but also provides a new testing method for the whole performance optimization of vertical axis wind energy conversion system (WECS).

Influence of intra-pigment vibrations on dynamics of photosynthetic exciton.

PubMed

Sato, Yoshihiro; Doolittle, Brian

2014-11-14

We have numerically investigated the effect of an underdamped intra-pigment vibrational mode on an exciton's quantum coherence and energy transfer efficiency. Our model describes a bacteriochlorophyll a pigment-protein dimer under the conditions at which photosynthetic energy transfer occurs. The dimer is modeled using a theoretical treatment of a vibronic exciton, and its dynamics are numerically analyzed using a non-Markovian and non-perturbative method. We examined the system's response to various values of the Huang-Rhys factor, site energy difference, reorganization energy, and reorganization energy difference. We found that the inclusion of the intra-pigment vibronic mode allows for long-lived oscillatory quantum coherences to occur. This excitonic coherence is robust against static site-energy disorder. The vibrational mode also promotes exciton transfer along the site-energy landscape thus improving the overall energy transfer efficiency.

Foldover effect and energy output from a nonlinear pseudo-maglev harvester

NASA Astrophysics Data System (ADS)

Kecik, Krzysztof; Mitura, Andrzej; Warminski, Jerzy; Lenci, Stefano

2018-01-01

Dynamics analysis and energy harvesting of a nonlinear magnetic pseudo-levitation (pseudo-maglev) harvester under harmonic excitation is presented in this paper. The system, for selected parameters, has two stable possible solutions with different corresponding energy outputs. The main goal is to analyse the influence of resistance load on the multi-stability zones and energy recovery which can help to tune the system to improve the energy harvesting efficiency.

An insight into actual energy use and its drivers in high-performance buildings

DOE PAGES

Li, Cheng; Hong, Tianzhen; Yan, Da

2014-07-12

Using portfolio analysis and individual detailed case studies, we studied the energy performance and drivers of energy use in 51 high-performance office buildings in the U.S., Europe, China, and other parts of Asia. Portfolio analyses revealed that actual site energy use intensity (EUI) of the study buildings varied by a factor of as much as 11, indicating significant variation in real energy use in HPBs worldwide. Nearly half of the buildings did not meet the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) Standard 90.1-2004 energy target, raising questions about whether a building’s certification as high performing accuratelymore » indicates that a building is energy efficient and suggesting that improvement in the design and operation of HPBs is needed to realize their energy-saving potential. We studied the influence of climate, building size, and building technologies on building energy performance and found that although all are important, none are decisive factors in building energy use. EUIs were widely scattered in all climate zones. There was a trend toward low energy use in small buildings, but the correlation was not absolute; some small HPBs exhibited high energy use, and some large HPBs exhibited low energy use. We were unable to identify a set of efficient technologies that correlated directly to low EUIs. In two case studies, we investigated the influence of occupant behavior as well as operation and maintenance on energy performance and found that both play significant roles in realizing energy savings. We conclude that no single factor determines the actual energy performance of HPBs, and adding multiple efficient technologies does not necessarily improve building energy performance; therefore, an integrated design approach that takes account of climate, technology, occupant behavior, and operations and maintenance practices should be implemented to maximize energy savings in HPBs. As a result, these findings are intended to help architects, engineers, operators, and policy makers improve the design and operation of HPBs.« less

An analysis of partial efficiencies of energy utilisation of different macronutrients by barramundi (Lates calcarifer) shows that starch restricts protein utilisation in carnivorous fish.

PubMed

Glencross, Brett D; Blyth, David; Bourne, Nicholas; Cheers, Susan; Irvin, Simon; Wade, Nicholas M

2017-02-01

This study examined the effect of including different dietary proportions of starch, protein and lipid, in diets balanced for digestible energy, on the utilisation efficiencies of dietary energy by barramundi (Lates calcarifer). Each diet was fed at one of three ration levels (satiety, 80 % of initial satiety and 60 % of initial satiety) for a 42-d period. Fish performance measures (weight gain, feed intake and feed conversion ratio) were all affected by dietary energy source. The efficiency of energy utilisation was significantly reduced in fish fed the starch diet relative to the other diets, but there were no significant effects between the other macronutrients. This reduction in efficiency of utilisation was derived from a multifactorial change in both protein and lipid utilisation. The rate of protein utilisation deteriorated as the amount of starch included in the diet increased. Lipid utilisation was most dramatically affected by inclusion levels of lipid in the diet, with diets low in lipid producing component lipid utilisation rates well above 1·3, which indicates substantial lipid synthesis from other energy sources. However, the energetic cost of lipid gain was as low as 0·65 kJ per kJ of lipid deposited, indicating that barramundi very efficiently store energy in the form of lipid, particularly from dietary starch energy. This study defines how the utilisation efficiency of dietary digestible energy by barramundi is influenced by the macronutrient source providing that energy, and that the inclusion of starch causes problems with protein utilisation in this species.

Greens, suits, and bureaucrats: A sociological study of dynamic organizational relationships in energy efficient appliance policy

NASA Astrophysics Data System (ADS)

Shwom-Evelich, Rachael Leah

In this dissertation I develop an approach to understanding dynamic organizational relations and the processes of environmental degradation and reform. To do this, I draw on environmental and organizational sociology to inform an empirical study of interorganizational relationships in defining and promoting energy efficient appliances in the United States (US). The dissertation follows a three paper approach which involves (a) an overall introduction to the substantive issue of appliance energy efficiency in the US; (b) producing three separate and stand alone articles of publishable quality to be submitted to professional journals; and (c) an overall conclusion. The three articles are as follows: (1) a synthetic literature review identifying five lessons that organizational sociology and environmental sociology can learn from each other to advance our sociological understanding of organizations, energy issues, and climate change (2) a qualitative case study of the changing relationships between business, government and environmental and energy advocacy organizations around mandatory appliance efficiency standards supporting the development of a context-dependent theory of ecological modernization and treadmill of production theories in environmental sociology and (3) a network analysis of public government, business and energy efficiency advocate's interorganizational relationships and its influence on subsequent organizational behaviors in the appliance energy efficiency field. The second and third articles are based on extensive archival research on organizational negotiations of public record over defining energy efficient appliances in both regulatory and voluntary settings. Finally I will provide an overall conclusion that brings together the most significant findings of each individual article in anticipation of a synthetic approach to the study of organizations in environmental reform.

Evaluation energy efficiency of bioconversion knot rejects to ethanol in comparison to other thermochemically pretreated biomass.

PubMed

Wang, Zhaojiang; Qin, Menghua; Zhu, J Y; Tian, Guoyu; Li, Zongquan

2013-02-01

Rejects from sulfite pulp mill that otherwise would be disposed of by incineration were converted to ethanol by a combined physical-biological process that was comprised of physical refining and simultaneous saccharification and fermentation (SSF). The energy efficiency was evaluated with comparison to thermochemically pretreated biomass, such as those pretreated by dilute acid (DA) and sulfite pretreatment to overcome recalcitrance of lignocelluloses (SPORL). It was observed that the structure deconstruction of rejects by physical refining was indispensable to effective bioconversion but more energy intensive than that of thermochemically pretreated biomass. Fortunately, the energy consumption was compensated by the reduced enzyme dosage and the elevated ethanol yield. Furthermore, adjustment of disk-plates gap led to reduction in energy consumption with negligible influence on ethanol yield. In this context, energy efficiency up to 717.7% was achieved for rejects, much higher than that of SPORL sample (283.7%) and DA sample (152.8%). Copyright © 2012 Elsevier Ltd. All rights reserved.

Public policies, private choices: Consumer desire and the practice of energy efficiency

NASA Astrophysics Data System (ADS)

Deumling, Reuben Alexander

Refrigerator energy consumption has been the subject of regulatory attention in the US for some thirty years. Federal product standards, energy labels, and a variety of programs to get consumers to discard their existing refrigerators sooner and buy new, more energy efficient ones have transformed the refrigerator landscape and changed how many of us think about refrigerators. The results of these policies are celebrated as a successful model for how to combine regulatory objectives and consumer preferences in pursuit of environmental outcomes where everyone wins. Yet per capita refrigerator energy consumption today remains (much) higher in the US than anywhere else, in part because energy efficiency overlooks the ways behavior, habit, emulation, social norms, advertising, and energy efficiency policies themselves shape energy consumption patterns. To understand these dynamics I investigate how people replacing their refrigerators through a state-sponsored energy efficiency program make sense of the choices facing them, and how various types of information designed to aid in this process (Consumer Reports tests, Energy Guide labels, rebate programs) frame the issue of responsible refrigerator consumption. Using interviews and archival research I examine how this information is used to script the choice of a refrigerator, whose priorities shape the form and content of these cues, and what the social meanings generated by and through encounters with refrigerators and energy efficiency are. I also helped build a model for estimating historic refrigerator energy consumption in the US, to measure the repercussions of refrigerator energy inefficiency. My focus in this dissertation is on the ways the pursuit of energy efficiency improvements for domestic refrigerators intersects with and sometimes reinforces escalating demand for energy. My research suggests that the practice of pursuing energy efficiency improvements in refrigerators subordinates the issue of refrigerator energy consumption---what factors influence it, how and why it fluctuated historically, how to take it seriously---in pursuit of increased sales. The a priori assumption that consumers desire certain styles of refrigerator has become a compulsion to trade up. In evaluating the results of energy policies celebrating technical achievements without paying attention to the social dynamics which these regulations encounter is insufficient.

Variable cross-section windings for efficiency improvement of electric machines

NASA Astrophysics Data System (ADS)

Grachev, P. Yu; Bazarov, A. A.; Tabachinskiy, A. S.

2018-02-01

Implementation of energy-saving technologies in industry is impossible without efficiency improvement of electric machines. The article considers the ways of efficiency improvement and mass and dimensions reduction of electric machines with electronic control. Features of compact winding design for stators and armatures are described. Influence of compact winding on thermal and electrical process is given. Finite element method was used in computer simulation.

Investigation of operating parameters on CO2 splitting by dielectric barrier discharge plasma

NASA Astrophysics Data System (ADS)

Pan, CHEN; Jun, SHEN; Tangchun, RAN; Tao, YANG; Yongxiang, YIN

2017-12-01

Experiments of CO2 splitting by dielectric barrier discharge (DBD) plasma were carried out, and the influence of CO2 flow rate, plasma power, discharge voltage, discharge frequency on CO2 conversion and process energy efficiency were investigated. It was shown that the absolute quantity of CO2 decomposed was only proportional to the amount of conductive electrons across the discharge gap, and the electron amount was proportional to the discharge power; the energy efficiency of CO2 conversion was almost a constant at a lower level, which was limited by CO2 inherent discharge character that determined a constant gap electric field strength. This was the main reason why CO2 conversion rate decreased as the CO2 flow rate increase and process energy efficiency was decreased a little as applied frequency increased. Therefore, one can improve the CO2 conversion by less feed flow rate or larger discharge power in DBD plasma, but the energy efficiency is difficult to improve.

Effect of Shoes on Stiffness and Energy Efficiency of Ankle-Foot Orthosis: Bench Testing Analysis.

PubMed

Kobayashi, Toshiki; Gao, Fan; LeCursi, Nicholas; Foreman, K Bo; Orendurff, Michael S

2017-12-01

Understanding the mechanical properties of ankle-foot orthoses (AFOs) is important to maximize their benefit for those with movement disorders during gait. Though mechanical properties such as stiffness and/or energy efficiency of AFOs have been extensively studied, it remains unknown how and to what extent shoes influence their properties. The aim of this study was to investigate the effect of shoes on stiffness and energy efficiency of an AFO using a custom mechanical testing device. Stiffness and energy efficiency of the AFO were measured in the plantar flexion and dorsiflexion range, respectively, under AFO-alone and AFO-Shoe combination conditions. The results of this study demonstrated that the stiffness of the AFO-Shoe combination was significantly decreased compared to the AFO-alone condition, but no significant differences were found in energy efficiency. From the results, we recommend that shoes used with AFOs should be carefully selected not only based on their effect on alignment of the lower limb, but also their effects on overall mechanical properties of the AFO-Shoe combination. Further study is needed to clarify the effects of differences in shoe designs on AFO-Shoe combination mechanical properties.

Frequency-dependent ultrasound-induced transformation in E. coli.

PubMed

Deeks, Jeremy; Windmill, James; Agbeze-Onuma, Maduka; Kalin, Robert M; Argondizza, Peter; Knapp, Charles W

2014-12-01

Ultrasound-enhanced gene transfer (UEGT) is continuing to gain interest across many disciplines; however, very few studies investigate UEGT efficiency across a range of frequencies. Using a variable frequency generator, UEGT was tested in E. coli at six ultrasonic frequencies. Results indicate frequency can significantly influence UEGT efficiency positively and negatively. A frequency of 61 kHz improved UEGT efficiency by ~70 % higher, but 99 kHz impeded UEGT to an extent worse than no ultrasound exposure. The other four frequencies (26, 133, 174, and 190 kHz) enhanced transformation compared to no ultrasound, but efficiencies did not vary. The influence of frequency on UEGT efficiency was observed across a range of operating frequencies. It is plausible that frequency-dependent dynamics of mechanical and chemical energies released during cavitational-bubble collapse (CBC) are responsible for observed UEGT efficiencies.

Efficiency Assessment of the Power Supply System of an Industrial Enterprise Through the Assessment of the Modes of Electric Power Consumption

NASA Astrophysics Data System (ADS)

Miatishkin, Gennadii V.; Filinova, Anastasiia S.

2018-01-01

The paper reviews the terms of the rational consumption and distribution of the energy resources at an enterprise. The authors analyze the significance and the effect of the change of the profile of the energy consumption per hour by the enterprise. The text explores the factors influencing the discipline of the planned electricity and power consumption. The authors present a calculation of the weighted average deviations for consumers and the terms of their assessment. The authors make conclusions concerning the rationality of the means of defining the energy efficiency system through the assessment of the modes of electric energy consumption of an industrial enterprise.

The influence of opening windows and doors on the natural ventilation rate of a residential building

EPA Science Inventory

Increased building energy efficiency is important in reducing national energy use and greenhouse gas emissions. An analysis of air change rates due to door and window openings in a research test house located in a residential environment are presented. These data inform developme...

Numerical study of hydrodynamic behavior and conversion efficiency of a two-buoy wave energy converter

NASA Astrophysics Data System (ADS)

Yang, Cen; Zhang, Yong-liang

2018-04-01

In this paper we propose a two-buoy wave energy converter composed of a heaving semi-submerged cylindrical buoy, a fixed submerged cylindrical buoy and a power take-off (PTO) system, and investigate the effect of the fixed submerged buoy on the hydrodynamics of the heaving semi-submerged buoy based on the three-dimensional potential theory. And the dynamic response of the semi-submerged buoy and the wave energy conversion efficiency of the converter are analyzed. The difference of the hydrodynamics and the wave energy conversion efficiency of a semi-submerged buoy converter with and without a fixed submerged buoy is discussed. It is revealed that the influence of the fixed submerged buoy on the exciting wave force, the added mass, the radiation damping coefficient and the wave energy conversion efficiency can be significant with a considerable variation, depending on the vertical distance between the heaving semi-submerged buoy and the fixed submerged buoy, the diameter ratio of the fixed submerged buoy to the heaving semi-submerged buoy and the water depth.

Influences of Excess Oscillation of Voltage Pulse and Discharge Mode on NO Removal Using Barrier-Type Plasma Reactor

NASA Astrophysics Data System (ADS)

Kadowaki, Kazunori; Suzuki, Yoshiaki; Ihori, Haruo; Kitani, Isamu

This paper presents experimental results of NO removal from a simulated exhausted-gas using a barrier type reactor with screw electrodes subjected to polarity-reversed voltage pulses. The polarity-reversed pulse was produced by direct grounding of a charged coaxial cable because a traveling wave voltage was negatively reflected at the grounding end with a change in its polarity and then it propagated to the plasma reactor at the opposite end. Influence of cable length on NO removal was studied for two kinds of cable connection, single-connected cable and parallel-connected cables. NO removal ratio for a 50m-long cable was lower than that for much shorter cables in both single and parallel connections when the applied voltage became high. Energy efficiency for NO removal also increased with decreasing the cable length. This was because excess discharges during the voltage oscillation caused by the large stored energy in the long cable resulted in reproduction of NO molecules. Energy efficiency was further improved by changing the discharge mode from dielectric barrier discharge (DBD) to surface discharge (SD). Energy efficiency was up to 110g/kWh with 55% NO removal ratio and 34g/kWh with 100% NO removal ratio by using a single 10m-long cable in SD mode.

Efficiency of energy recovery from municipal solid waste and the resultant effect on the greenhouse gas balance.

PubMed

Gohlke, Oliver

2009-11-01

Global warming is a focus of political interest and life-cycle assessment of waste management systems reveals that energy recovery from municipal solid waste is a key issue. This paper demonstrates how the greenhouse gas effects of waste treatment processes can be described in a simplified manner by considering energy efficiency indicators. For evaluation to be consistent, it is necessary to use reasonable system boundaries and to take the generation of electricity and the use of heat into account. The new European R1 efficiency criterion will lead to the development and implementation of optimized processes/systems with increased energy efficiency which, in turn, will exert an influence on the greenhouse gas effects of waste management in Europe. Promising technologies are: the increase of steam parameters, reduction of in-plant energy consumption, and the combined use of heat and power. Plants in Brescia and Amsterdam are current examples of good performance with highly efficient electricity generation. Other examples of particularly high heat recovery rates are the energy-from-waste (EfW) plants in Malmö and Gothenburg. To achieve the full potential of greenhouse gas reduction in waste management, it is necessary to avoid landfilling combustible wastes, for example, by means of landfill taxes and by putting incentives in place for increasing the efficiency of EfW systems.

Process Performances of 2 ns Pulsed Discharge Plasma

NASA Astrophysics Data System (ADS)

Matsumoto, Takao; Wang, Douyan; Namihira, Takao; Akiyama, Hidenori

2011-08-01

Pulsed discharge plasmas have been used to treat exhaust gases. Since pulse duration and the rise time of applied voltage to the discharge electrode has a strong influence on the energy efficiency of pollutant removal, the development of a short-pulse generator is of paramount importance for practical applications. In this work, it is demonstrated that the non thermal plasma produced by the 2 ns pulsed discharge has a higher energy efficiency than the 5 ns pulsed discharge plasma for NO removal and ozone generation. Typically, the NO removal efficiency was 1.0 mol kW-1 h-1 for 70% NO removal (initial NO concentration = 200 ppm, gas flow = 10 L/min). Meanwhile, the ozone yield was 500 g kW-1 h-1 for 20 g/m3 ozone concentration in the case of oxygen feeding. These energy efficiencies are the highest in the literature.

Exergy analysis on industrial boiler energy conservation and emission evaluation applications

NASA Astrophysics Data System (ADS)

Li, Henan

2017-06-01

Industrial boiler is one of the most energy-consuming equipments in china, the annual consumption of energy accounts for about one-third of the national energy consumption. Industrial boilers in service at present have several severe problems such as small capacity, low efficiency, high energy consumption and causing severe pollution on environment. In recent years, our country in the big scope, long time serious fog weather, with coal-fired industrial boilers is closely related to the regional characteristics of high strength and low emissions [1]. The energy-efficient and emission-reducing of industry boiler is of great significance to improve China’s energy usage efficiency and environmental protection. Difference in thermal equilibrium theory is widely used in boiler design, exergy analysis method is established on the basis of the first law and second law of thermodynamics, by studying the cycle of the effect of energy conversion and utilization, to analyze its influencing factors, to reveal the exergy loss of location, distribution and size, find out the weak links, and a method of mining system of the boiler energy saving potential. Exergy analysis method is used for layer combustion boiler efficiency and pollutant emission characteristics analysis and evaluation, and can more objectively and accurately the energy conserving potential of the mining system of the boiler, find out the weak link of energy consumption, and improve equipment performance to improve the industrial boiler environmental friendliness.

Efficient Coding and Energy Efficiency Are Promoted by Balanced Excitatory and Inhibitory Synaptic Currents in Neuronal Network

PubMed Central

Yu, Lianchun; Shen, Zhou; Wang, Chen; Yu, Yuguo

2018-01-01

Selective pressure may drive neural systems to process as much information as possible with the lowest energy cost. Recent experiment evidence revealed that the ratio between synaptic excitation and inhibition (E/I) in local cortex is generally maintained at a certain value which may influence the efficiency of energy consumption and information transmission of neural networks. To understand this issue deeply, we constructed a typical recurrent Hodgkin-Huxley network model and studied the general principles that governs the relationship among the E/I synaptic current ratio, the energy cost and total amount of information transmission. We observed in such a network that there exists an optimal E/I synaptic current ratio in the network by which the information transmission achieves the maximum with relatively low energy cost. The coding energy efficiency which is defined as the mutual information divided by the energy cost, achieved the maximum with the balanced synaptic current. Although background noise degrades information transmission and imposes an additional energy cost, we find an optimal noise intensity that yields the largest information transmission and energy efficiency at this optimal E/I synaptic transmission ratio. The maximization of energy efficiency also requires a certain part of energy cost associated with spontaneous spiking and synaptic activities. We further proved this finding with analytical solution based on the response function of bistable neurons, and demonstrated that optimal net synaptic currents are capable of maximizing both the mutual information and energy efficiency. These results revealed that the development of E/I synaptic current balance could lead a cortical network to operate at a highly efficient information transmission rate at a relatively low energy cost. The generality of neuronal models and the recurrent network configuration used here suggest that the existence of an optimal E/I cell ratio for highly efficient energy costs and information maximization is a potential principle for cortical circuit networks. Summary We conducted numerical simulations and mathematical analysis to examine the energy efficiency of neural information transmission in a recurrent network as a function of the ratio of excitatory and inhibitory synaptic connections. We obtained a general solution showing that there exists an optimal E/I synaptic ratio in a recurrent network at which the information transmission as well as the energy efficiency of this network achieves a global maximum. These results reflect general mechanisms for sensory coding processes, which may give insight into the energy efficiency of neural communication and coding. PMID:29773979

Efficient Coding and Energy Efficiency Are Promoted by Balanced Excitatory and Inhibitory Synaptic Currents in Neuronal Network.

PubMed

Yu, Lianchun; Shen, Zhou; Wang, Chen; Yu, Yuguo

2018-01-01

Selective pressure may drive neural systems to process as much information as possible with the lowest energy cost. Recent experiment evidence revealed that the ratio between synaptic excitation and inhibition (E/I) in local cortex is generally maintained at a certain value which may influence the efficiency of energy consumption and information transmission of neural networks. To understand this issue deeply, we constructed a typical recurrent Hodgkin-Huxley network model and studied the general principles that governs the relationship among the E/I synaptic current ratio, the energy cost and total amount of information transmission. We observed in such a network that there exists an optimal E/I synaptic current ratio in the network by which the information transmission achieves the maximum with relatively low energy cost. The coding energy efficiency which is defined as the mutual information divided by the energy cost, achieved the maximum with the balanced synaptic current. Although background noise degrades information transmission and imposes an additional energy cost, we find an optimal noise intensity that yields the largest information transmission and energy efficiency at this optimal E/I synaptic transmission ratio. The maximization of energy efficiency also requires a certain part of energy cost associated with spontaneous spiking and synaptic activities. We further proved this finding with analytical solution based on the response function of bistable neurons, and demonstrated that optimal net synaptic currents are capable of maximizing both the mutual information and energy efficiency. These results revealed that the development of E/I synaptic current balance could lead a cortical network to operate at a highly efficient information transmission rate at a relatively low energy cost. The generality of neuronal models and the recurrent network configuration used here suggest that the existence of an optimal E/I cell ratio for highly efficient energy costs and information maximization is a potential principle for cortical circuit networks. We conducted numerical simulations and mathematical analysis to examine the energy efficiency of neural information transmission in a recurrent network as a function of the ratio of excitatory and inhibitory synaptic connections. We obtained a general solution showing that there exists an optimal E/I synaptic ratio in a recurrent network at which the information transmission as well as the energy efficiency of this network achieves a global maximum. These results reflect general mechanisms for sensory coding processes, which may give insight into the energy efficiency of neural communication and coding.

Numerical investigation of output beam quality in efficient broadband optical parametric chirped pulse amplification

NASA Astrophysics Data System (ADS)

Liu, Xiao-Di; Xu, Lu; Liang, Xiao-Yan

2017-01-01

We theoretically analyzed output beam quality of broad bandwidth non-collinear optical parametric chirped pulse amplification (NOPCPA) in LiB3O5 (LBO) centered at 800 nm. With a three-dimensional numerical model, the influence of the pump intensity, pump and signal spatial modulations, and the walk-off effect on the OPCPA output beam quality are presented, together with conversion efficiency and the gain spectrum. The pump modulation is a dominant factor that affects the output beam quality. Comparatively, the influence of signal modulation is insignificant. For a low-energy system with small beam sizes, walk-off effect has to be considered. Pump modulation and walk-off effect lead to asymmetric output beam profile with increased modulation. A special pump modulation type is found to optimize output beam quality and efficiency. For a high-energy system with large beam sizes, the walk-off effect can be neglected, certain back conversion is beneficial to reduce the output modulation. A trade-off must be made between the output beam quality and the conversion efficiency, especially when the pump modulation is large since. A relatively high conversion efficiency and a low output modulation are both achievable by controlling the pump modulation and intensity.

Energy-saving management modelling and optimization for lead-acid battery formation process

NASA Astrophysics Data System (ADS)

Wang, T.; Chen, Z.; Xu, J. Y.; Wang, F. Y.; Liu, H. M.

2017-11-01

In this context, a typical lead-acid battery producing process is introduced. Based on the formation process, an efficiency management method is proposed. An optimization model with the objective to minimize the formation electricity cost in a single period is established. This optimization model considers several related constraints, together with two influencing factors including the transformation efficiency of IGBT charge-and-discharge machine and the time-of-use price. An example simulation is shown using PSO algorithm to solve this mathematic model, and the proposed optimization strategy is proved to be effective and learnable for energy-saving and efficiency optimization in battery producing industries.

Fuzzy-Logic Based Distributed Energy-Efficient Clustering Algorithm for Wireless Sensor Networks.

PubMed

Zhang, Ying; Wang, Jun; Han, Dezhi; Wu, Huafeng; Zhou, Rundong

2017-07-03

Due to the high-energy efficiency and scalability, the clustering routing algorithm has been widely used in wireless sensor networks (WSNs). In order to gather information more efficiently, each sensor node transmits data to its Cluster Head (CH) to which it belongs, by multi-hop communication. However, the multi-hop communication in the cluster brings the problem of excessive energy consumption of the relay nodes which are closer to the CH. These nodes' energy will be consumed more quickly than the farther nodes, which brings the negative influence on load balance for the whole networks. Therefore, we propose an energy-efficient distributed clustering algorithm based on fuzzy approach with non-uniform distribution (EEDCF). During CHs' election, we take nodes' energies, nodes' degree and neighbor nodes' residual energies into consideration as the input parameters. In addition, we take advantage of Takagi, Sugeno and Kang (TSK) fuzzy model instead of traditional method as our inference system to guarantee the quantitative analysis more reasonable. In our scheme, each sensor node calculates the probability of being as CH with the help of fuzzy inference system in a distributed way. The experimental results indicate EEDCF algorithm is better than some current representative methods in aspects of data transmission, energy consumption and lifetime of networks.

Spectral Monte Carlo simulation of collimated solar irradiation transfer in a water-filled prismatic louver.

PubMed

Cai, Yaomin; Guo, Zhixiong

2018-04-20

The Monte Carlo model was developed to simulate the collimated solar irradiation transfer and energy harvest in a hollow louver made of silica glass and filled with water. The full solar spectrum from the air mass 1.5 database was adopted and divided into various discrete bands for spectral calculations. The band-averaged spectral properties for the silica glass and water were obtained. Ray tracing was employed to find the solar energy harvested by the louver. Computational efficiency and accuracy were examined through intensive comparisons of different band partition approaches, various photon numbers, and element divisions. The influence of irradiation direction on the solar energy harvest efficiency was scrutinized. It was found that within a 15° polar angle of incidence, the harvested solar energy in the louver was high, and the total absorption efficiency reached 61.2% under normal incidence for the current louver geometry.

Energy distribution analysis in boosted HCCI-like / LTGC engines – Understanding the trade-offs to maximize the thermal efficiency

DOE PAGES

Dernotte, Jeremie; Dec, John E.; Ji, Chunsheng

2015-04-14

A detailed understanding of the various factors affecting the trends in gross-indicated thermal efficiency with changes in key operating parameters has been carried out, applied to a one-liter displacement single-cylinder boosted Low-Temperature Gasoline Combustion (LTGC) engine. This work systematically investigates how the supplied fuel energy splits into the following four energy pathways: gross-indicated thermal efficiency, combustion inefficiency, heat transfer and exhaust losses, and how this split changes with operating conditions. Additional analysis is performed to determine the influence of variations in the ratio of specific heat capacities (γ) and the effective expansion ratio, related to the combustion-phasing retard (CA50), onmore » the energy split. Heat transfer and exhaust losses are computed using multiple standard cycle analysis techniques. Furthermore, the various methods are evaluated in order to validate the trends.« less

Numerical prediction of the energy efficiency of the three-dimensional fish school using the discretized Adomian decomposition method

NASA Astrophysics Data System (ADS)

Lin, Yinwei

2018-06-01

A three-dimensional modeling of fish school performed by a modified Adomian decomposition method (ADM) discretized by the finite difference method is proposed. To our knowledge, few studies of the fish school are documented due to expensive cost of numerical computing and tedious three-dimensional data analysis. Here, we propose a simple model replied on the Adomian decomposition method to estimate the efficiency of energy saving of the flow motion of the fish school. First, the analytic solutions of Navier-Stokes equations are used for numerical validation. The influences of the distance between the side-by-side two fishes are studied on the energy efficiency of the fish school. In addition, the complete error analysis for this method is presented.

An energy efficient multiple mobile sinks based routing algorithm for wireless sensor networks

NASA Astrophysics Data System (ADS)

Zhong, Peijun; Ruan, Feng

2018-03-01

With the fast development of wireless sensor networks (WSNs), more and more energy efficient routing algorithms have been proposed. However, one of the research challenges is how to alleviate the hot spot problem since nodes close to static sink (or base station) tend to die earlier than other sensors. The introduction of mobile sink node can effectively alleviate this problem since sink node can move along certain trajectories, causing hot spot nodes more evenly distributed. In this paper, we mainly study the energy efficient routing method with multiple mobile sinks support. We divide the whole network into several clusters and study the influence of mobile sink number on network lifetime. Simulation results show that the best network performance appears when mobile sink number is about 3 under our simulation environment.

Statistical properties of proportional residual energy intake as a new measure of energetic efficiency.

PubMed

Zamani, Pouya

2017-08-01

Traditional ratio measures of efficiency, including feed conversion ratio (FCR), gross milk efficiency (GME), gross energy efficiency (GEE) and net energy efficiency (NEE) may have some statistical problems including high correlations with milk yield. Residual energy intake (REI) or residual feed intake (RFI) is another criterion, proposed to overcome the problems attributed to the traditional ratio criteria, but it does not account for production or intake levels. For example, the same REI value could be considerable for low producing and negligible for high producing cows. The aim of this study was to propose a new measure of efficiency to overcome the problems attributed to the previous criteria. A total of 1478 monthly records of 268 lactating Holstein cows were used for this study. In addition to FCR, GME, GEE, NEE and REI, a new criterion called proportional residual energy intake (PREI) was calculated as REI to net energy intake ratio and defined as proportion of net energy intake lost as REI. The PREI had an average of -0·02 and range of -0·36 to 0·27, meaning that the least efficient cow lost 0·27 of her net energy intake as REI, while the most efficient animal saved 0·36 of her net energy intake as less REI. Traditional ratio criteria (FCR, GME, GEE and NEE) had high correlations with milk and fat corrected milk yields (absolute values from 0·469 to 0·816), while the REI and PREI had low correlations (0·000 to 0·069) with milk production. The results showed that the traditional ratio criteria (FCR, GME, GEE and NEE) are highly influenced by production traits, while the REI and PREI are independent of production level. Moreover, the PREI adjusts the REI magnitude for intake level. It seems that the PREI could be considered as a worthwhile measure of efficiency for future studies.

An assessment of energy efficiency based on environmental constraints and its influencing factors in China.

PubMed

Chen, Yao; Xu, Jing-Ting

2018-05-03

The super-efficiency directional distance function (DDF) with data envelopment analysis (DEA) model (SEDDF-DEA) is more facilitative than to increase traditional method as a rise of energy efficiency in China, which is currently important energy development from Asia-pacific region countries. SEDDF-DEA is promoted as sustained total-factor energy efficiency (TFEE), value added outputs, and Malmquist-Luenberger productivity index (MLPI) to otherwise thorny environmental energy productivity problems with environmental constraint to concrete the means of regression model. This paper assesses the energy efficiency under environmental constraints using panel data covering the years of 2000-2015 in China. Considering the environmental constraints, the results showed that the average TFEE of the whole country followed an upward trend after 2006. The average MLPI score for the whole country increased by 10.57% during 2005-2010, which was mainly due to the progress made in developing and applying environmental technologies. The TFEE of the whole nation was promoted by the accumulation of capital stock, while it was suppressed by excessive production in secondary industries and foreign investment. The primary challenge for the northeast of China is to strengthen industrial transformation and upgrade traditional industries, as well as adjusting the economy and energy structure. The eastern and central regions of the country need to exploit clean- or low-energy industry to improve inefficiencies due to excessive consumption. The western region of China needs to implement renewable energy strategies to promote regional development.

Improving the accuracy of energy baseline models for commercial buildings with occupancy data

DOE PAGES

Liang, Xin; Hong, Tianzhen; Shen, Geoffrey Qiping

2016-07-07

More than 80% of energy is consumed during operation phase of a building's life cycle, so energy efficiency retrofit for existing buildings is considered a promising way to reduce energy use in buildings. The investment strategies of retrofit depend on the ability to quantify energy savings by “measurement and verification” (M&V), which compares actual energy consumption to how much energy would have been used without retrofit (called the “baseline” of energy use). Although numerous models exist for predicting baseline of energy use, a critical limitation is that occupancy has not been included as a variable. However, occupancy rate is essentialmore » for energy consumption and was emphasized by previous studies. This study develops a new baseline model which is built upon the Lawrence Berkeley National Laboratory (LBNL) model but includes the use of building occupancy data. The study also proposes metrics to quantify the accuracy of prediction and the impacts of variables. However, the results show that including occupancy data does not significantly improve the accuracy of the baseline model, especially for HVAC load. The reasons are discussed further. In addition, sensitivity analysis is conducted to show the influence of parameters in baseline models. To conclude, the results from this study can help us understand the influence of occupancy on energy use, improve energy baseline prediction by including the occupancy factor, reduce risks of M&V and facilitate investment strategies of energy efficiency retrofit.« less

Factors affecting energy and nitrogen efficiency of dairy cows: a meta-analysis.

PubMed

Phuong, H N; Friggens, N C; de Boer, I J M; Schmidely, P

2013-01-01

A meta-analysis was performed to explore the correlation between energy and nitrogen efficiency of dairy cows, and to study nutritional and animal factors that influence these efficiencies, as well as their relationship. Treatment mean values were extracted from 68 peer-reviewed studies, including 306 feeding trials. The main criterion for inclusion of a study in the meta-analysis was that it reported, or permitted calculation of, energy efficiency (Eeff; energy in milk/digestible energy intake) and nitrogen efficiency (Neff; nitrogen in milk/digestible nitrogen intake) at the digestible level (digestible energy or digestible protein). The effect of nutritional and animal variables, including neutral detergent fiber, acid detergent fiber (ADF), digestible energy, digestible protein, proportion of concentrate (PCO), dry matter intake, milk yield, days in milk, and body weight, on Eeff, Neff, and the Neff:Eeff ratio was analyzed using mixed models. The interstudy correlation between Eeff and Neff was 0.62, whereas the intrastudy correlation was 0.30. The higher interstudy correlation was partly due to milk yield and dry matter intake being present in both Eeff and Neff. We, therefore, also explored the Neff:Eeff ratio. Energy efficiency was negatively associated with ADF and PCO, whereas Neff was negatively associated with ADF and digestible energy. The Neff:Eeff ratio was affected by ADF and PCO only. In conclusion, the results indicate a possibility to maximize feed efficiency in terms of both energy and nitrogen at the same time. In other words, an improvement in Eeff would also mean an improvement in Neff. The current study also shows that these types of transverse data are not sufficient to study the effect of animal factors, such as days in milk, on feed efficiency. Longitudinal measurements per animal would probably be more appropriate. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Understanding biorefining efficiency--the case of agrifood waste.

PubMed

Kuisma, Miia; Kahiluoto, Helena; Havukainen, Jouni; Lehtonen, Eeva; Luoranen, Mika; Myllymaa, Tuuli; Grönroos, Juha; Horttanainen, Mika

2013-05-01

The aim of this study was to determine biorefining efficiency according to the choices made in the entire value chain. The importance of the share of biomass volume biorefined or products substituted was investigated. Agrifood-waste-based biorefining represented the case. Anticipatory scenarios were designed for contrasting targets and compared with the current situation in two Finnish regions. Biorefining increases nutrient and energy efficiency in comparison with current use of waste. System boundaries decisively influence the relative efficiency of biorefining designs. For nutrient efficiency, full exploitation of biomass potential and anaerobic digestion increase nutrient efficiency, but the main determinant is efficient substitution for mineral fertilisers. For energy efficiency, combustion and location of biorefining close to heat demand are crucial. Regional differences in agricultural structure, the extent of the food industry and population density have a major impact on biorefining. High degrees of exploitation of feedstock potential and substitution efficiency are the keys. Copyright © 2012 Elsevier Ltd. All rights reserved.

Application of acoustic agglomeration to enhance air filtration efficiency in air-conditioning and mechanical ventilation (ACMV) systems.

PubMed

Ng, Bing Feng; Xiong, Jin Wen; Wan, Man Pun

2017-01-01

The recent episodes of haze in Southeast Asia have caused some of the worst regional atmospheric pollution ever recorded in history. In order to control the levels of airborne fine particulate matters (PM) indoors, filtration systems providing high PM capturing efficiency are often sought, which inadvertently also results in high airflow resistance (or pressure drop) that increases the energy consumption for air distribution. A pre-conditioning mechanism promoting the formation of particle clusters to enhance PM capturing efficiency without adding flow resistance in the air distribution ductwork could provide an energy-efficient solution. This pre-conditioning mechanism can be fulfilled by acoustic agglomeration, which is a phenomenon that promotes the coagulation of suspended particles by acoustic waves propagating in the fluid medium. This paper discusses the basic mechanisms of acoustic agglomeration along with influencing factors that could affect the agglomeration efficiency. The feasibility to apply acoustic agglomeration to improve filtration in air-conditioning and mechanical ventilation (ACMV) systems is investigated experimentally in a small-scale wind tunnel. Experimental results indicate that this novel application of acoustic pre-conditioning improves the PM2.5 filtration efficiency of the test filters by up to 10% without introducing additional pressure drop. The fan energy savings from not having to switch to a high capturing efficiency filter largely outstrip the additional energy consumed by the acoustics system. This, as a whole, demonstrates potential energy savings from the combined acoustic-enhanced filtration system without compromising on PM capturing efficiency.

Application of acoustic agglomeration to enhance air filtration efficiency in air-conditioning and mechanical ventilation (ACMV) systems

PubMed Central

Xiong, Jin Wen; Wan, Man Pun

2017-01-01

The recent episodes of haze in Southeast Asia have caused some of the worst regional atmospheric pollution ever recorded in history. In order to control the levels of airborne fine particulate matters (PM) indoors, filtration systems providing high PM capturing efficiency are often sought, which inadvertently also results in high airflow resistance (or pressure drop) that increases the energy consumption for air distribution. A pre-conditioning mechanism promoting the formation of particle clusters to enhance PM capturing efficiency without adding flow resistance in the air distribution ductwork could provide an energy-efficient solution. This pre-conditioning mechanism can be fulfilled by acoustic agglomeration, which is a phenomenon that promotes the coagulation of suspended particles by acoustic waves propagating in the fluid medium. This paper discusses the basic mechanisms of acoustic agglomeration along with influencing factors that could affect the agglomeration efficiency. The feasibility to apply acoustic agglomeration to improve filtration in air-conditioning and mechanical ventilation (ACMV) systems is investigated experimentally in a small-scale wind tunnel. Experimental results indicate that this novel application of acoustic pre-conditioning improves the PM2.5 filtration efficiency of the test filters by up to 10% without introducing additional pressure drop. The fan energy savings from not having to switch to a high capturing efficiency filter largely outstrip the additional energy consumed by the acoustics system. This, as a whole, demonstrates potential energy savings from the combined acoustic-enhanced filtration system without compromising on PM capturing efficiency. PMID:28594862

Environmental sustainability of bioethanol produced from sweet sorghum stem on saline-alkali land.

PubMed

Wang, Mingxin; Pan, Xinxing; Xia, Xunfeng; Xi, Beidou; Wang, Lijun

2015-01-01

Life cycle assessment was conducted to evaluate the energy efficiency and environmental impacts of a bioethanol production system that uses sweet sorghum stem on saline-alkali land as feedstock. The system comprises a plant cultivation unit, a feedstock transport unit, and a bioethanol conversion unit, with 1000L of bioethanol as a functional unit. The net energy ratio is 3.84, and the net energy gain is 17.21MJ/L. Agrochemical production consumes 76.58% of the life cycle fossil energy. The category with the most significant impact on the environment is eutrophication, followed by acidification, fresh water aquatic ecotoxicity, human toxicity, and global warming. Allocation method, waste recycling approach, and soil salinity significantly influence the results. Using vinasse to produce pellet fuel for steam generation significantly improves energy efficiency and decreases negative environmental impacts. Promoting reasonable management practices to alleviate saline stress and increasing agrochemical utilization efficiency can further improve environmental sustainability. Copyright © 2015 Elsevier Ltd. All rights reserved.

Aspect ratio dependence of auger recombination and carrier multiplication in PbSe nanorods.

PubMed

Padilha, Lazaro A; Stewart, John T; Sandberg, Richard L; Bae, Wan Ki; Koh, Weon-Kyu; Pietryga, Jeffrey M; Klimov, Victor I

2013-03-13

Nanomaterials with efficient carrier multiplication (CM), that is, generation of multiple electron-hole pairs by single photons, have been the object of intense scientific interest as potential enablers of high efficiency generation-III photovoltaics. In this work, we explore nanocrystal shape control as a means for enhancing CM. Specifically, we investigate the influence of aspect ratio (ρ) of PbSe nanorods (NRs) on both CM and the inverse of this process, Auger recombination. We observe that Auger lifetimes in NRs increase with increasing particle volume and for a fixed cross-sectional size follow a linear dependence on the NR length. For a given band gap energy, the CM efficiency in NRs shows a significant dependence on aspect ratio and exhibits a maximum at ρ ∼ 6-7 for which the multiexciton yields are a factor of ca. 2 higher than those in quantum dots with a similar bandgap energy. To rationalize our experimental observations, we analyze the influence of dimensionality on both CM and non-CM energy-loss mechanisms and offer possible explanations for the seemingly divergent effects the transition from zero- to one-dimensional confinement has on the closely related processes of Auger recombination and CM.

Enhancement of the efficiency of dye-sensitized solar cell with multi-wall carbon nanotubes/polypyrrole composite counter electrodes prepared by electrophoresis/electrochemical polymerization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Jun; Niu, Hai-jun; Wen, Hai-lin

2013-03-15

Graphical abstract: The overall energy conversion efficiency of the DSSC employing the MWCNT/PPy CE reached 3.78%. Compared with a reference DSSC using single MWCNT film CE with efficiency of 2.68%, the energy conversion efficiency was increased by 41.04%. Highlights: ► MWCNT/PPy composite film prepared by electrodeposition layer by layer was used as counter electrode in DSSC. ► The overall energy conversion efficiency of the DSSC was 3.78% by employing the composite film. ► The energy conversion efficiency increased by 41.04% compared with efficiency of 2.68% by using the single MWCNT film. ► We analyzed the mechanism and influence factor ofmore » electron transfer in the composite electrode by EIS. - Abstract: For the purpose of replacing the precious Pt counter electrode in dye-sensitized solar cells (DSSCs) with higher energy conversion efficiency, multi-wall carbon nanotube (MWCNT)/polypyrrole (PPy) double layers film counter electrode (CE) was fabricated by electrophoresis and cyclic voltammetry (CV) layer by layer. Atom force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscope (TEM) demonstrated the morphologies of the composite electrode and Raman spectroscopy verified the PPy had come into being. The overall energy conversion efficiency of the DSSC employing the MWCNT/PPy CE reached 3.78%. Compared with a reference DSSC using single MWCNT film CE with efficiency of 2.68%, the energy conversion efficiency was increased by 41.04%. The result of impedance showed that the charge transfer resistance R{sub ct} of the MWCNT/PPy CE had the lowest value compared to that of MWCNT or PPy electrode. These results indicate that the composite film with high conductivity, high active surface area, and good catalytic properties for I{sub 3}{sup −} reduction can potentially be used as the CE in a high-performance DSSC.« less

Butanol production from food waste: a novel process for producing sustainable energy and reducing environmental pollution

USDA-ARS?s Scientific Manuscript database

Efficient utilization of food waste for fuel and chemical production can positively influence both the energy and environmental sustainability. In these studies we investigated use of food waste to produce butanol by Clostridium beijerinckii P260. In control fermentation, 40.5 g/L of glucose (initia...

Collective acceleration of ions in a system with an insulated anode

NASA Astrophysics Data System (ADS)

Bystritskii, V. M.; Didenko, A. N.; Krasik, Ya. E.; Lopatin, V. S.; Podkatov, V. I.

1980-11-01

An investigation was made of the processes of collective acceleration of protons in vacuum in a system with an insulated anode and trans-anode electrodes, which were insulated or grounded, in high-current Tonus and Vera electron accelerators. The influence of external conditions and parameters of the electron beam on the efficiency of acceleration processes was investigated. Experiments were carried out in which protons were accelerated in a system with trans-anode electrodes. A study was made of the influence of a charge prepulse and of the number of trans-anode electrodes on the energy of the accelerated electrons. A system with a single anode produced Np=1014 protons of 2Ee < Ep < 3Ee energy. Suppression of a charge prepulse increased the proton energy to (6 8)Ee and the yield was then 1013. The maximum proton energy of 14Ee was obtained in a system with three trans-anode electrodes. A possible mechanism of proton acceleration was analyzed. The results obtained were compared with those of other investigations. Ways of increasing the efficiency of this acceleration method were considered.

Forecast and analysis of the ratio of electric energy to terminal energy consumption for global energy internet

NASA Astrophysics Data System (ADS)

Wang, Wei; Zhong, Ming; Cheng, Ling; Jin, Lu; Shen, Si

2018-02-01

In the background of building global energy internet, it has both theoretical and realistic significance for forecasting and analysing the ratio of electric energy to terminal energy consumption. This paper firstly analysed the influencing factors of the ratio of electric energy to terminal energy and then used combination method to forecast and analyse the global proportion of electric energy. And then, construct the cointegration model for the proportion of electric energy by using influence factor such as electricity price index, GDP, economic structure, energy use efficiency and total population level. At last, this paper got prediction map of the proportion of electric energy by using the combination-forecasting model based on multiple linear regression method, trend analysis method, and variance-covariance method. This map describes the development trend of the proportion of electric energy in 2017-2050 and the proportion of electric energy in 2050 was analysed in detail using scenario analysis.

Design and experimental investigation of an ejector in an air-conditioning and refrigeration system

DOE Office of Scientific and Technical Information (OSTI.GOV)

AL-Khalidy, N.; Zayonia, A.

1995-12-31

This paper discusses the conservation of energy in a refrigerant ejector refrigerating machine using heat driven from the concentrator collectors. The working refrigerant was R-113. The design of an ejector operating in an air-conditioning and refrigerating system with a low thermal source (70 C to 100 C) is presented. The influence of three major parameters--boiler, condenser, and evaporator temperature--on ejector efficiency is discussed. Experimental results show that the condenser temperature is the major influence at a low evaporator temperature. The maximum ejector efficiency was 31%.

Factors influencing the life cycle burdens of the recovery of energy from residual municipal waste.

PubMed

Burnley, Stephen; Coleman, Terry; Peirce, Adam

2015-05-01

A life cycle assessment was carried out to assess a selection of the factors influencing the environmental impacts and benefits of incinerating the fraction of municipal waste remaining after source-separation for reuse, recycling, composting or anaerobic digestion. The factors investigated were the extent of any metal and aggregate recovery from the bottom ash, the thermal efficiency of the process, and the conventional fuel for electricity generation displaced by the power generated. The results demonstrate that incineration has significant advantages over landfill with lower impacts from climate change, resource depletion, acidification, eutrophication human toxicity and aquatic ecotoxicity. To maximise the benefits of energy recovery, metals, particularly aluminium, should be reclaimed from the residual bottom ash and the energy recovery stage of the process should be as efficient as possible. The overall environmental benefits/burdens of energy from waste also strongly depend on the source of the power displaced by the energy from waste, with coal giving the greatest benefits and combined cycle turbines fuelled by natural gas the lowest of those considered. Regardless of the conventional power displaced incineration presents a lower environmental burden than landfill. Copyright © 2015 Elsevier Ltd. All rights reserved.

The JPL space photovoltaic program. [energy efficient so1 silicon solar cells for space applications

NASA Technical Reports Server (NTRS)

Scott-Monck, J. A.

1979-01-01

The development of energy efficient solar cells for space applications is discussed. The electrical performance of solar cells as a function of temperature and solar intensity and the influence of radiation and subsequent thermal annealing on the electrical behavior of cells are among the factors studied. Progress in GaAs solar cell development is reported with emphasis on improvement of output power and radiation resistance to demonstrate a solar cell array to meet the specific power and stability requirements of solar power satellites.

Drivers of grazing livestock efficiency: how physiology, metabolism, experience, and adaptability influence productivity

USDA-ARS?s Scientific Manuscript database

Beef cow efficiency, a century’s old debate, on what the criteria, certain phenotypic traits, and definition of an “efficient” cow really should be. However, we do know that energy utilization by the cow herd is proportionally large compared to the rest of the sector. This requirement accounts up to...

Drivers of grazing livestock efficiency: how physiology, metabolism, experience and adaptability influence productivity

USDA-ARS?s Scientific Manuscript database

Beef cow efficiency, a century’s old debate, on what the criteria, certain phenotypic traits, and definition of an “efficient” cow really should be. However, we do know that energy utilization by the cow herd is proportionally large compared to the rest of the sector. This requirement accounts up to...

The effect of early berthing prospects on the energy efficiency operational index in oil tanker vessels

NASA Astrophysics Data System (ADS)

Acomi, N.; Acomi, O. C.

2016-08-01

Marine pollution is one of the main concerns of our society. In order to reduce air pollution produced by ships, the International Maritime Organization has developed technical, operational and management measures. Part of the operational measures refers to CO2 emissions that contribute to the energy efficiency of the vessel. The difficulty in assessing the energy efficiency of the vessel rests with the diversity of voyage parameters, including quantity of cargo, distance and type of fuel in use. Assessing the energy efficiency of the vessel is thus not a matter of determining the absolute value of the CO2, but of providing a meaningful construct to enable tracking performance trends over time, for the same ship, a fleet of ships or across the industry. This concept is the Energy Efficiency Operational Index, EEOI. The purpose of this study is to analyse the influence of a well predicted voyage on the EEOI value. The method used consists in a comparative analysis of two situations regarding berthing prospects: the real passage plan and an early prediction that supposes the vessel to arrive on time as required. The results of the study represent a monitoring tool for the ship owners to assess the EEOI from the early stage of designing the berthing prospects.

Space-planning and structural solutions of low-rise buildings: Optimal selection methods

NASA Astrophysics Data System (ADS)

Gusakova, Natalya; Minaev, Nikolay; Filushina, Kristina; Dobrynina, Olga; Gusakov, Alexander

2017-11-01

The present study is devoted to elaboration of methodology used to select appropriately the space-planning and structural solutions in low-rise buildings. Objective of the study is working out the system of criteria influencing the selection of space-planning and structural solutions which are most suitable for low-rise buildings and structures. Application of the defined criteria in practice aim to enhance the efficiency of capital investments, energy and resource saving, create comfortable conditions for the population considering climatic zoning of the construction site. Developments of the project can be applied while implementing investment-construction projects of low-rise housing at different kinds of territories based on the local building materials. The system of criteria influencing the optimal selection of space-planning and structural solutions of low-rise buildings has been developed. Methodological basis has been also elaborated to assess optimal selection of space-planning and structural solutions of low-rise buildings satisfying the requirements of energy-efficiency, comfort and safety, and economical efficiency. Elaborated methodology enables to intensify the processes of low-rise construction development for different types of territories taking into account climatic zoning of the construction site. Stimulation of low-rise construction processes should be based on the system of approaches which are scientifically justified; thus it allows enhancing energy efficiency, comfort, safety and economical effectiveness of low-rise buildings.

Efficiency analysis of betavoltaic elements

NASA Astrophysics Data System (ADS)

Sachenko, A. V.; Shkrebtii, A. I.; Korkishko, R. M.; Kostylyov, V. P.; Kulish, M. R.; Sokolovskyi, I. O.

2015-09-01

The conversion of energy of electrons produced by a radioactive β-source into electricity in a Si and SiC p- n junctions is modeled. The features of the generation function that describes the electron-hole pair production by an electron flux and the emergence of a "dead layer" are discussed. The collection efficiency Q that describes the rate of electron-hole pair production by incident beta particles, is calculated taking into account the presence of the dead layer. It is shown that in the case of high-grade Si p- n junctions, the collection efficiency of electron-hole pairs created by a high-energy electrons flux (such as, e.g., Pm-147 beta flux) is close or equal to unity in a wide range of electron energies. For SiC p-n junctions, Q is near unity only for electrons with relatively low energies of about 5 keV (produced, e.g., by a tritium source) and decreases rapidly with further increase of electron energy. The conditions, under which the influence of the dead layer on the collection efficiency is negligible, are determined. The open-circuit voltage is calculated for realistic values of the minority carriers' diffusion coefficients and lifetimes in Si and SiC p- n junctions, irradiated by a high-energy electrons flux. Our calculations allow to estimate the attainable efficiency of betavoltaic elements.

System Dynamics Modeling of Households' Electricity Consumption and Cost-Income Ratio: a Case Study of Latvia

NASA Astrophysics Data System (ADS)

Bariss, Uldis; Bazbauers, Gatis; Blumberga, Andra; Blumberga, Dagnija

2017-11-01

Increased energy efficiency of the building sector is high on the list of priorities for energy policy since better energy efficiency would help to reduce impact on climate change and increase security of energy supply. One aim of the present study was to find a relative effect of growth of demand for energy services due to changes in income, energy consumption per unit of demand due to technological development, changes in electricity price and household income on household electricity consumption in Latvia. The method applied included system dynamics modeling and data from a household survey regarding the relationship between electricity saving activities and the electricity cost-income ratio. The results revealed that, in direct contrast to the expected, a potential reduction of the electricity consumption is rather insensitive to electricity price and electricity cost-income ratio, and that the efficiency of technologies could be the main drivers for future electricity savings. The results suggest that support to advancement of technologies and faster replacement of inefficient ones rather than influencing the energy price could be effective energy policy measures. The model, developed in the study could be used in similar assessments in other countries.

Environmental policy and technological change: The effects of economic incentives and direct regulation on energy-saving innovation

NASA Astrophysics Data System (ADS)

Newell, Richard G., Jr.

Over the long run, the impacts of environmental policies will be greatly affected by the influence these policies have on the rate and direction of technological change. In particular, the roles played by energy prices and product regulation in energy-saving technology innovation are exceptionally important considerations in modeling climate change and evaluating alternative policy options. We analyze the effects of energy prices and energy-efficiency regulations on the menu of air conditioner and water heater models available on the market over a period of more than three decades, measuring their innovation in terms of improvements in the products' underlying characteristics. Through estimation of a series of "characteristics transformation surfaces," we find that during less than four decades, substantial innovation in these products reduced the total capital and operating costs of air conditioning by one-half and water heating by more than one-fifth. Although the overall rate of innovation in these products appears to be independent of energy prices and regulations, the evidence suggests that the direction of innovation may be responsive to energy price changes. This would imply that energy price increases induced innovation in a direction that lowered the capital cost tradeoffs inherent in producing more energy-efficient products. The evidence supporting "regulation-induced" changes in these tradeoffs is much weaker. Our estimates indicate that about one- to two-fifths of the energy-efficiency improvements in these products from 1973 to 1993 were associated with historical changes in energy prices. We also find that this responsiveness to price changes increased substantially after product labeling requirements came into effect, and that minimum efficiency standards had a significant positive effect on average efficiency levels. Nonetheless, a sizeable portion of historical efficiency improvements in these technologies is associated with the products' overall rate of innovation. Looking forward, we estimate that energy taxes of 10 to 30 percent of retail prices could significantly increase the energy efficiency of the product menu. We predict that such taxes would lead to additional efficiency increases in air conditioners of 6 to 26 percent. We conclude that the price-induced component of energy-efficiency innovation should not be ignored when assessing alternative climate change policies.

Heat rejection efficiency research of new energy automobile radiators

NASA Astrophysics Data System (ADS)

Ma, W. S.; Shen, W. X.; Zhang, L. W.

2018-03-01

The driving system of new energy vehicle has larger heat load than conventional engine. How to ensure the heat dissipation performance of the cooling system is the focus of the design of new energy vehicle thermal management system. In this paper, the heat dissipation efficiency of the radiator of the hybrid electric vehicle is taken as the research object, the heat dissipation efficiency of the radiator of the new energy vehicle is studied through the multi-working-condition enthalpy difference test. In this paper, the test method in the current standard QC/T 468-2010 “automobile radiator” is taken, but not limited to the test conditions specified in the standard, 5 types of automobile radiator are chosen, each of them is tested 20 times in simulated condition of different wind speed and engine inlet temperature. Finally, regression analysis is carried out for the test results, and regression equation describing the relationship of radiator heat dissipation heat dissipation efficiency air side flow rate cooling medium velocity and inlet air temperature is obtained, and the influence rule is systematically discussed.

An Assessment of Energy-Related Career Paths of Senior Industrial Assessment Center Program Alumni

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, M.A.

2003-10-20

The purpose of this study was to assess the career paths of alumni from the U.S. Department of Energy's Industrial Assessment Center (IAC) program. IAC was originally named the Energy Analysis and Diagnostic Center (EADC) program when it began in association with four schools in 1976. The current IAC program provides funding to 26 engineering colleges, located in centers across the United States, to conduct energy, waste, and productivity assessments for small- to medium-sized manufacturing establishments within their respective regions. Through part-time employment with the university, students receive training and in turn conduct assessments for local manufacturers, under the directmore » supervision of engineering faculty. Annually, IAC participants conduct over 700 assessments, and each assessment generates recommendations for energy savings, energy cost savings, and waste and productivity cost savings customized for individual clients. An earlier study determined that energy savings could be attributed to alumni of the IAC program who take their IAC experiences with them to the professional workplace. During their careers, the alumni conduct additional energy assessments as well as influence energy efficiency through design, teaching and training, and other activities. Indeed, a significant level of program benefits can be attributed to the alumni. This project addressed such specific questions as: How many years after graduation are IAC alumni involved in energy-efficiency activities? What different methods do they use to influence energy-efficiency decisions? To answer these questions, the University of Tennessee, Knoxville (UT) surveyed IAC senior alumni, defined as those who graduated in 1995 or earlier. Section 2 describes the survey used in this research. The actual survey can be found in Appendix A. Section 3 describes our approach to data collection. Section 4 presents descriptive statistics about the senior alumni who responded to the survey. Section 5 begins with the presentation of two frameworks used to help analyze the data about alumni career paths and then presents the career path results. Section 6 offers concluding remarks.« less

Numerical analysis of flow interaction of turbine system in two-stage turbocharger of internal combustion engine

NASA Astrophysics Data System (ADS)

Liu, Y. B.; Zhuge, W. L.; Zhang, Y. J.; Zhang, S. Y.

2016-05-01

To reach the goal of energy conservation and emission reduction, high intake pressure is needed to meet the demand of high power density and high EGR rate for internal combustion engine. Present power density of diesel engine has reached 90KW/L and intake pressure ratio needed is over 5. Two-stage turbocharging system is an effective way to realize high compression ratio. Because turbocharging system compression work derives from exhaust gas energy. Efficiency of exhaust gas energy influenced by design and matching of turbine system is important to performance of high supercharging engine. Conventional turbine system is assembled by single-stage turbocharger turbines and turbine matching is based on turbine MAP measured on test rig. Flow between turbine system is assumed uniform and value of outlet physical quantities of turbine are regarded as the same as ambient value. However, there are three-dimension flow field distortion and outlet physical quantities value change which will influence performance of turbine system as were demonstrated by some studies. For engine equipped with two-stage turbocharging system, optimization of turbine system design will increase efficiency of exhaust gas energy and thereby increase engine power density. However flow interaction of turbine system will change flow in turbine and influence turbine performance. To recognize the interaction characteristics between high pressure turbine and low pressure turbine, flow in turbine system is modeled and simulated numerically. The calculation results suggested that static pressure field at inlet to low pressure turbine increases back pressure of high pressure turbine, however efficiency of high pressure turbine changes little; distorted velocity field at outlet to high pressure turbine results in swirl at inlet to low pressure turbine. Clockwise swirl results in large negative angle of attack at inlet to rotor which causes flow loss in turbine impeller passages and decreases turbine efficiency. However negative angle of attack decreases when inlet swirl is anti-clockwise and efficiency of low pressure turbine can be increased by 3% compared to inlet condition of clockwise swirl. Consequently flow simulation and analysis are able to aid in figuring out interaction mechanism of turbine system and optimizing turbine system design.

Airport Analyses Informing New Mobility Shifts: Opportunities to Adapt Energy-Efficient Mobility Services and Infrastructure: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henao, Alejandro; Sperling, Joshua; Young, Stanley E

An airport is one of the most important assets for a region's economic development and connectivity with the rest of the nation and world. Key aspects for investigation of energy efficient mobility at airports is ground transportation including factors ranging from the infrastructure, mobility services, and associated revenues. Data is critical to understand the maturity of new mobility services that can inform both cities and airports on how to respond, approach, manage, and adapt to the challenges, opportunities, and uncertainties associated with shifts in new mobility that influence human behavior, energy-efficiency and sustainability strategies. One key question identified in thismore » article is how quickly we are adapting to new mobility options - such as app-based ride-hailing and 'pooling' services - that may provide an opportunity to influence energy efficiency of ground transportation to and from airports. By starting with airports in the regions of four smart city finalists in the U.S. DOT Smart City Challenge, this paper focuses on key observability aspects of new modes and the rate of shifts in mobility patterns across San Francisco, Portland, Denver, and Kansas City. With the emerging megatrend of rising urbanization and rising air travel demand (a predicted doubling in demand by 2035), airports are expected to increasingly be on the front lines of adaptation to new transportation technology and services in terms of infrastructure investments, policies, and revenues. As airports have demonstrated the most potential and capability of any public institution to implement fees for new ride-hailing services, they are also a prime resource for collecting important data to help understand smart mobility transitions. Results focused on the shifts in revenues for ground transportation at airports offer one vantage point into the pace of transitions and adaptations in the new emerging mobility landscape, and present an opportunity to analyze how future adaptations could support more energy-efficient scenarios.« less

Building America Case Study: New Town Builders' Power of Zero Energy Center, Denver, Colorado (Brochure)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

New Town Builders, a builder of energy efficient homes in Denver, Colorado, offers a zero energy option for all the homes it builds. To attract a wide range of potential homebuyers to its energy efficient homes, New Town Builders created a 'Power of Zero Energy Center' linked to its model home in the Stapleton community of Denver. This case study presents New Town Builders' marketing approach, which is targeted to appeal to homebuyers' emotions rather than overwhelming homebuyers with scientific details about the technology. The exhibits in the Power of Zero Energy Center focus on reduced energy expenses for themore » homeowner, improved occupant comfort, the reputation of the builder, and the lack of sacrificing the homebuyers' desired design features to achieve zero net energy in the home. The case study also contains customer and realtor testimonials related to the effectiveness of the Center in influencing homebuyers to purchase a zero energy home.« less

New Whole-House Solutions Case Study: New Town Builders' Power of Zero Energy Center - Denver, Colorado

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

New Town Builders, a builder of energy efficient homes in Denver, Colorado, offers a zero energy option for all the homes it builds. To attract a wide range of potential homebuyers to its energy efficient homes, New Town Builders created a "Power of Zero Energy Center" linked to its model home in the Stapleton community. This case study presents New Town Builders' marketing approach, which is targeted to appeal to homebuyers' emotions rather than overwhelming homebuyers with scientific details about the technology. The exhibits in the Power of Zero Energy Center focus on reduced energy expenses for the homeowner, improvedmore » occupant comfort, the reputation of the builder, and the lack of sacrificing the homebuyers' desired design features to achieve zero net energy in the home. This case study also contains customer and realtor testimonials related to the effectiveness of the Center in influencing homebuyers to purchase a zero energy home.« less

Energy demand and thermal comfort of HVAC systems with thermally activated building systems as a function of user profile

NASA Astrophysics Data System (ADS)

Pałaszyńska, Katarzyna; Bandurski, Karol; Porowski, Mieczysław

2017-11-01

Thermally Activated Building Systems (TABS) are a way to use building structure as a thermal energy storage. As a result, renewable energy sources may be used more efficiently. The paper presents numerical analysis of a HVAC system with TABS energy demand and indoor thermal comfort of a representative room in a non-residential building (governmental, commercial, educational). The purpose of analysis is to investigate the influence of a user profile on system performance. The time span of the analysis is one year - a typical meteorological year. The model was prepared using a generally accepted simulation tool - TRNSYS 17. The results help to better understand the interaction of a user profile with TABS. Therefore they are important for the development of optimal control algorithms for energy efficient buildings equipped with such systems.

Flapping wing applied to wind generators

NASA Astrophysics Data System (ADS)

Colidiuc, Alexandra; Galetuse, Stelian; Suatean, Bogdan

2012-11-01

The new conditions at the international level for energy source distributions and the continuous increasing of energy consumption must lead to a new alternative resource with the condition of keeping the environment clean. This paper offers a new approach for a wind generator and is based on the theoretical aerodynamic model. This new model of wind generator helped me to test what influences would be if there will be a bird airfoil instead of a normal wind generator airfoil. The aim is to calculate the efficiency for the new model of wind generator. A representative direction for using the renewable energy is referred to the transformation of wind energy into electrical energy, with the help of wind turbines; the development of such systems lead to new solutions based on high efficiency, reduced costs and suitable to the implementation conditions.

Energy intensity modeling for wastewater treatment technologies.

PubMed

Molinos-Senante, María; Sala-Garrido, Ramón; Iftimi, Adina

2018-07-15

Wastewater treatment plants (WWTPs) are energy intensive facilities; therefore increased pressure has been placed on managers and policy makers to reduce the facilities' energy use. Several studies were conducted to compare the energy intensity (EI) of WWTPs, which showed large dispersion in EI among the facilities. In the present study, the degree EI influenced WWTPs was tested using a set of technical variables by modeling the EI of a 305 WWTP sample grouped into five secondary treatment technologies. Results indicated the following two major findings: i) WWTPs using conventional activated sludge, extended aeration, trickling biofilters, and biodisks exhibited significant economies of scale in energy use; and ii) pollutant removal efficiency demonstrated low impacts on WWTP EI. The methodology and results of this study are of value to policy makers in planning new WWTPs and developing management plans to improve energy efficiency of wastewater treatment. Copyright © 2018. Published by Elsevier B.V.

IEA EBC annex 53: Total energy use in buildings—Analysis and evaluation methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoshino, Hiroshi; Hong, Tianzhen; Nord, Natasa

One of the most significant barriers to achieving deep building energy efficiency is a lack of knowledge about the factors determining energy use. In fact, there is often a significant discrepancy between designed and real energy use in buildings, which is poorly understood but are believed to have more to do with the role of human behavior than building design. Building energy use is mainly influenced by six factors: climate, building envelope, building services and energy systems, building operation and maintenance, occupants’ activities and behavior, and indoor environmental quality. In the past, much research focused on the first three factors.more » However, the next three human-related factors can have an influence as significant as the first three. Annex 53 employed an interdisciplinary approach, integrating building science, architectural engineering, computer modeling and simulation, and social and behavioral science to develop and apply methods to analyze and evaluate the real energy use in buildings considering the six influencing factors. Finally, outcomes from Annex 53 improved understanding and strengthen knowledge regarding the robust prediction of total energy use in buildings, enabling reliable quantitative assessment of energy-savings measures, policies, and techniques.« less

IEA EBC annex 53: Total energy use in buildings—Analysis and evaluation methods

DOE PAGES

Yoshino, Hiroshi; Hong, Tianzhen; Nord, Natasa

2017-07-18

One of the most significant barriers to achieving deep building energy efficiency is a lack of knowledge about the factors determining energy use. In fact, there is often a significant discrepancy between designed and real energy use in buildings, which is poorly understood but are believed to have more to do with the role of human behavior than building design. Building energy use is mainly influenced by six factors: climate, building envelope, building services and energy systems, building operation and maintenance, occupants’ activities and behavior, and indoor environmental quality. In the past, much research focused on the first three factors.more » However, the next three human-related factors can have an influence as significant as the first three. Annex 53 employed an interdisciplinary approach, integrating building science, architectural engineering, computer modeling and simulation, and social and behavioral science to develop and apply methods to analyze and evaluate the real energy use in buildings considering the six influencing factors. Finally, outcomes from Annex 53 improved understanding and strengthen knowledge regarding the robust prediction of total energy use in buildings, enabling reliable quantitative assessment of energy-savings measures, policies, and techniques.« less

Nanocrystal Size-Dependent Efficiency of Quantum Dot Sensitized Solar Cells in the Strongly Coupled CdSe Nanocrystals/TiO2 System.

PubMed

Yun, Hyeong Jin; Paik, Taejong; Diroll, Benjamin; Edley, Michael E; Baxter, Jason B; Murray, Christopher B

2016-06-15

Light absorption and electron injection are important criteria determining solar energy conversion efficiency. In this research, monodisperse CdSe quantum dots (QDs) are synthesized with five different diameters, and the size-dependent solar energy conversion efficiency of CdSe quantum dot sensitized solar cell (QDSSCs) is investigated by employing the atomic inorganic ligand, S(2-). Absorbance measurements and transmission electron microscopy show that the diameters of the uniform CdSe QDs are 2.5, 3.2, 4.2, 6.4, and 7.8 nm. Larger CdSe QDs generate a larger amount of charge under the irradiation of long wavelength photons, as verified by the absorbance results and the measurements of the external quantum efficiencies. However, the smaller QDs exhibit faster electron injection kinetics from CdSe QDs to TiO2 because of the high energy level of CBCdSe, as verified by time-resolved photoluminescence and internal quantum efficiency results. Importantly, the S(2-) ligand significantly enhances the electronic coupling between the CdSe QDs and TiO2, yielding an enhancement of the charge transfer rate at the interfacial region. As a result, the S(2-) ligand helps improve the new size-dependent solar energy conversion efficiency, showing best performance with 4.2-nm CdSe QDs, whereas conventional ligand, mercaptopropionic acid, does not show any differences in efficiency according to the size of the CdSe QDs. The findings reported herein suggest that the atomic inorganic ligand reinforces the influence of quantum confinement on the solar energy conversion efficiency of QDSSCs.

Division of energy biosciences: Annual report and summaries of FY 1995 activities

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-04-01

The mission of the Division of Energy Biosciences is to support research that advances the fundamental knowledge necessary for the future development of biotechnologies related to the Department of Energy`s mission. The departmental civilian objectives include effective and efficient energy production, energy conservation, environmental restoration, and waste management. The Energy Biosciences program emphasizes research in the microbiological and plant sciences, as these understudied areas offer numerous scientific opportunities to dramatically influence environmentally sensible energy production and conservation. The research supported is focused on the basic mechanisms affecting plant productivity, conversion of biomass and other organic materials into fuels and chemicalsmore » by microbial systems, and the ability of biological systems to replace energy-intensive or pollutant-producing processes. The Division also addresses the increasing number of new opportunities arising at the interface of biology with other basic energy-related sciences such as biosynthesis of novel materials and the influence of soil organisms on geological processes.« less

Boosting Photovoltaic Performance of Dye-Sensitized Solar Cells Using Silver Nanoparticle-Decorated N,S-Co-Doped-TiO2 Photoanode

PubMed Central

Lim, Su Pei; Pandikumar, Alagarsamy; Lim, Hong Ngee; Ramaraj, Ramasamy; Huang, Nay Ming

2015-01-01

A silver nanoparticle-decorated N,S-co-doped TiO2 nanocomposite was successfully prepared and used as an efficient photoanode in high-performance dye-sensitized solar cells (DSSCs) with N719 dye. The DSSCs assembled with the N,S-TiO2@Ag-modified photoanode demonstrated an enhanced solar-to-electrical energy conversion efficiency of 8.22%, which was better than that of a DSSC photoanode composed of unmodified TiO2 (2.57%) under full sunlight illumination (100 mWcm−2, AM 1.5 G). This enhanced efficiency was mainly attributed to the reduced band gap energy, improved interfacial charge transfer, and retarded charge recombination process. The influence of the Ag content on the overall efficiency was also investigated, and the optimum Ag content with N,S-TiO2 was found to be 20 wt%. Because of the enhanced solar energy conversion efficiency of the N,S-TiO2@Ag nanocomposite, it should be considered as a potential photoanode for high-performance DSSCs. PMID:26146362

Comparative Study Between Wind and Photovoltaic (PV) Systems

NASA Astrophysics Data System (ADS)

Taha, Wesam

This paper reviews two renewable energy systems; wind and photovoltaic (PV) systems. The common debate between the two of them is to conclude which one is better, in terms of cost and efficiency. Therefore, comparative study, in terms of cost and efficiency, is attempted. Regarding total cost of both, wind and PV systems, many parameters must be taken into consideration such as availability of energy (either wind or solar), operation and maintenance, availability of costumers, political influence, and the components used in building the system. The main components and parameters that play major role in determining the overall efficiency of wind systems are the wind turbine generator (WTG), gearbox and control technologies such as power, and speed control. On the other hand, in grid-connected PV systems (GCPVS), converter architecture along with maximum power point tracking (MPPT) algorithm and inverter topologies are the issues that affects the efficiency significantly. Cost and efficiency analyses of both systems have been carried out based on the statistics available till today and would be useful in the progress of renewable energy penetration throughout the world.

Design of experiment analysis of CO2 dielectric barrier discharge conditions on CO production

NASA Astrophysics Data System (ADS)

Becker, Markus; Ponduri, Srinath; Engeln, Richard; van de Sanden, Richard; Loffhagen, Detlef

2016-09-01

Dielectric barrier discharges (DBD) are frequently used for the generation of CO from CO2 which is of particular interest for syngas production. It has been found by means of fluid modelling in that the CO2 conversion frequency in a CO2 DBD depends linearly on the specific energy input (SEI) while the energy efficiency of CO production is only weakly dependent on the SEI. Here, the same numerical model as in is applied to study systematically the influence of gas pressure, applied voltage amplitude and frequency on the CO2 conversion frequency and the energy efficiency of CO production based on a 2-level 3-factor full factorial experimental design. It is found that the operating conditions of the CO2 DBD for CO production can be chosen to either have an optimal throughput or a better energy efficiency. This work was partly supported by the German Research Foundation within the Collaborative Research Centre Transregio 24.

Analysis of recovery efficiency in high-temperature aquifer thermal energy storage: a Rayleigh-based method

NASA Astrophysics Data System (ADS)

Schout, Gilian; Drijver, Benno; Gutierrez-Neri, Mariene; Schotting, Ruud

2014-01-01

High-temperature aquifer thermal energy storage (HT-ATES) is an important technique for energy conservation. A controlling factor for the economic feasibility of HT-ATES is the recovery efficiency. Due to the effects of density-driven flow (free convection), HT-ATES systems applied in permeable aquifers typically have lower recovery efficiencies than conventional (low-temperature) ATES systems. For a reliable estimation of the recovery efficiency it is, therefore, important to take the effect of density-driven flow into account. A numerical evaluation of the prime factors influencing the recovery efficiency of HT-ATES systems is presented. Sensitivity runs evaluating the effects of aquifer properties, as well as operational variables, were performed to deduce the most important factors that control the recovery efficiency. A correlation was found between the dimensionless Rayleigh number (a measure of the relative strength of free convection) and the calculated recovery efficiencies. Based on a modified Rayleigh number, two simple analytical solutions are proposed to calculate the recovery efficiency, each one covering a different range of aquifer thicknesses. The analytical solutions accurately reproduce all numerically modeled scenarios with an average error of less than 3 %. The proposed method can be of practical use when considering or designing an HT-ATES system.

ARTICLES: Physical laws governing the interaction of pulse-periodic CO2 laser radiation with metals

NASA Astrophysics Data System (ADS)

Vedenov, A. A.; Gladush, G. G.; Drobyazko, S. V.; Pavlovich, Yu V.; Senatorov, Yu M.

1985-01-01

It is shown theoretically and experimentally that the efficiency of welding metals with a pulse-periodic CO2 laser beam of low duty ratio, at low velocities, can exceed that of welding with cw lasers and with electron beams. For the first time an investigation was made of the influence of the laser radiation parameters (energy and frequency) and of the welding velocity on the characteristics of the weld and on the shape of the weldpool. The influence of the laser radiation polarization on the efficiency of deep penetration was analyzed.

Effects of laser source parameters on the generation of narrow band and directed laser ultrasound

NASA Technical Reports Server (NTRS)

Spicer, James B.; Deaton, John B., Jr.; Wagner, James W.

1992-01-01

Predictive and prescriptive modeling of laser arrays is performed to demonstrate the effects of the extension of array elements on laser array performance. For a repetitively pulsed laser source (the temporal laser array), efficient frequency compression is best achieved by detecting longitudinal waves off-epicenter in plates where the source size and shape directly influence the longitudinal wave shape and duration; the longitudinal array may be tailored for a given repetition frequency to yield efficient overtone energy compression into the fundamental frequency band. For phased arrays, apparent array directivity is heavily influenced by array element size.

Numerical Simulation of Energy Conversion Mechanism in Electric Explosion

NASA Astrophysics Data System (ADS)

Wanjun, Wang; Junjun, Lv; Mingshui, Zhu; Qiubo, Fu; EFIs Integration R&D Group Team

2017-06-01

Electric explosion happens when micron-scale metal films such as copper film is stimulated by short-time current pulse, while generating high temperature and high pressure plasma. The expansion process of the plasma plays an important role in the study of the generation of shock waves and the study of the EOS of matter under high pressure. In this paper, the electric explosion process is divided into two stages: the energy deposition stage and the quasi-isentropic expansion stage, and a dynamic EOS of plasma considering the energy replenishment is established. On this basis, flyer driven by plasma is studied numerically, the pressure and the internal energy of plasma in the energy deposition stage and the quasi - isentropic expansion stage are obtained by comparing the velocity history of the flyer with the experimental results. An energy conversion model is established, and the energy conversion efficiency of each process is obtained, and the influence of impedance matching relationship between flyer and metal plasma on the energy conversion efficiency is proposed in this paper.

Energy Harvesting with a Liquid-Metal Microfluidic Influence Machine

NASA Astrophysics Data System (ADS)

Conner, Christopher; de Visser, Tim; Loessberg, Joshua; Sherman, Sam; Smith, Andrew; Ma, Shuo; Napoli, Maria Teresa; Pennathur, Sumita; Weld, David

2018-04-01

We describe and demonstrate an alternative energy-harvesting technology based on a microfluidic realization of a Wimshurst influence machine. The prototype device converts the mechanical energy of a pressure-driven flow into electrical energy, using a multiphase system composed of droplets of liquid mercury surrounded by insulating oil. Electrostatic induction between adjacent metal droplets drives charge through external electrode paths, resulting in continuous charge amplification and collection. We demonstrate a power output of 4 nW from the initial prototype and present calculations suggesting that straightforward device optimization could increase the power output by more than 3 orders of magnitude. At that level, the power efficiency of this energy-harvesting mechanism, limited by viscous dissipation, could exceed 90%. The microfluidic context enables straightforward scaling and parallelization, as well as hydraulic matching to a variety of ambient mechanical energy sources, such as human locomotion.

Tapping the Potential for Energy Efficiency: The Role of ESCOs in the Czech Republic, Ukraine and Russia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, Meredydd

2000-12-31

Energy service companies have played a significant role in stimulating energy efficiency in many industrialized countries, including the United States. Many policymakers and development experts consider energy performance contracting an important mechanism for boosting energy efficiency in other countries as well. The experience of ESCOs in transition economies, however, is decidedly mixed. The Czech Republic has been able to foster a thriving ESCO industry with numerous players competing for business, although ESCOs have encountered problems along the way. In Russia and Ukraine, ESCOs have developed slowly, and few true performance contracts exist. This paper reviews the experience of ESCOs inmore » the Czech Republic, Ukraine and Russia and then explores the factors shaping the diverse trends in these countries. The paper draws on the experience of the national energy efficiency centers, development banks, bilateral assistance organizations and individual ESCOs in promoting ESCO industries. Factors that have influenced ESCOs to date include the economy, the price of energy, the financial situation of potential clients, the legislative basis for ESCO activities, the business experience of ESCO staff and access to information about the ESCO concept. Financing has also proven to be a critical factor in developing ESCOs. Lack of project financing and guarantees, for example, is a major problem in the former Soviet Union. The paper concludes by drawing recommendations for policymakers and industry on promoting ESCOs.« less

Scale model performance test investigation of exhaust system mixers for an Energy Efficient Engine /E3/ propulsion system

NASA Technical Reports Server (NTRS)

Kuchar, A. P.; Chamberlin, R.

1980-01-01

A scale model performance test was conducted as part of the NASA Energy Efficient Engine (E3) Program, to investigate the geometric variables that influence the aerodynamic design of exhaust system mixers for high-bypass, mixed-flow engines. Mixer configuration variables included lobe number, penetration and perimeter, as well as several cutback mixer geometries. Mixing effectiveness and mixer pressure loss were determined using measured thrust and nozzle exit total pressure and temperature surveys. Results provide a data base to aid the analysis and design development of the E3 mixed-flow exhaust system.

Time- and energy-efficient solution combustion synthesis of binary metal tungstate nanoparticles with enhanced photocatalytic activity.

PubMed

Thomas, Abegayl; Janáky, Csaba; Samu, Gergely F; Huda, Muhammad N; Sarker, Pranab; Liu, J Ping; van Nguyen, Vuong; Wang, Evelyn H; Schug, Kevin A; Rajeshwar, Krishnan

2015-05-22

In the search for stable and efficient photocatalysts beyond TiO2 , the tungsten-based oxide semiconductors silver tungstate (Ag2 WO4 ), copper tungstate (CuWO4 ), and zinc tungstate (ZnWO4 ) were prepared using solution combustion synthesis (SCS). The tungsten precursor's influence on the product was of particular relevance to this study, and the most significant effects are highlighted. Each sample's photocatalytic activity towards methyl orange degradation was studied and benchmarked against their respective commercial oxide sample obtained by solid-state ceramic synthesis. Based on the results herein, we conclude that SCS is a time- and energy-efficient method to synthesize crystalline binary tungstate nanomaterials even without additional excessive heat treatment. As many of these photocatalysts possess excellent photocatalytic activity, the discussed synthetic strategy may open sustainable materials chemistry avenues to solar energy conversion and environmental remediation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Definition of Static Voltage Characteristics of the Motor Load for the Purpose of Increase in Energy Efficiency of Coal Mines of Kuzbass

NASA Astrophysics Data System (ADS)

Nepsha, Fedor; Efremenko, Vladimir

2017-11-01

The task of determining the static load characteristics is one of the most important tasks, the solution of which is necessary for the correct development of measures to increase the energy efficiency of the Kuzbass coal mines. At present, the influence of electric receivers on the level of consumption of active and reactive power is not taken into account, therefore, the proposed measures to increase the energy efficiency are not optimal. The article analyzes the L-shaped and T-shaped circuit for the replacement of an asynchronous motor (AM), according to the results of which it is determined that the T-shaped replacement scheme is the most accurate for determination of static load characteristics. The authors proposed and implemented in the MATLAB Simulink environment an algorithm for determining the static voltage characteristics of the motor load.

Extinction cross-section suppression and active acoustic invisibility cloaking

NASA Astrophysics Data System (ADS)

Mitri, F. G.

2017-10-01

Invisibility in its canonical form requires rendering a zero extinction cross-section (or energy efficiency) from an active or a passive object. This work demonstrates the successful theoretical realization of this physical effect for an active cylindrically radiating acoustic body, undergoing periodic axisymmetric harmonic vibrations near a flat rigid boundary. Radiating, amplification and extinction cross-sections of the active source are defined. Assuming monopole and dipole modal oscillations of the circular source, conditions are found where the extinction energy efficiency factor of the active source vanishes, achieving total invisibility with minimal influence of the source size. It also takes positive or negative values, depending on its size and distance from the boundary. Moreover, the amplification energy efficiency factor is negative for the acoustically-active source. These effects also occur for higher-order modal oscillations of the active source. The results find potential applications in the development of acoustic cloaking devices and invisibility.

Comparison of the influence of age on cycling efficiency and the energy cost of running in well-trained triathletes.

PubMed

Peiffer, Jeremiah; Abbiss, Chris R; Sultana, Frederic; Bernard, Thierry; Brisswalter, Jeanick

2016-01-01

Locomotive efficiency is cited as an important component to endurance performance; however, inconsistent observations of age-related changes in efficiency question its influence in the performance of masters athletes. This study examined locomotive efficiency in young and masters triathletes during both a run and cycle test. Twenty young (28.5 ± 2.6 years) and 20 masters (59.8 ± 1.3 years) triathletes completed an incremental cycling and running test to determine maximal aerobic consumption (VO2max) and the first ventilatory threshold (VT1). Participants then completed 10-min submaximal running and cycling tests at VT1 during which locomotive efficiency was calculated from expired ventilation. Additionally, body fat percentage was determined using skin-fold assessment. During the cycle and run, VO2max was lower in the masters (48.3 ± 5.4 and 49.6 ± 4.8 ml kg(-1) min(-1), respectively) compared with young (61.6 ± 5.7 and 62.4 ± 5.2 ml kg(-1) min(-1), respectively) cohort. Maximal running speed and the cycling power output corresponding to VO2max were also lower in the masters (15.1 ± 0.8 km h(-1) and 318.6 ± 26.0 W) compared with the young (19.5 ± 1.3 km h(-1) and 383.6 ± 35.0 W) cohort. Cycling efficiency was lower (-11.2%) in the masters compared with young cohort. Similar results were observed for the energy cost of running (+10.8%); however, when scaled to lean body mass, changes were more pronounced during the run (+22.1%). Within trained triathletes, ageing can influence efficiency in both the run and cycle discipline. While disregarded in the past, efficiency should be considered in research examining performance in ageing athletes.

Protein Hydration Thermodynamics: The Influence of Flexibility and Salt on Hydrophobin II Hydration.

PubMed

Remsing, Richard C; Xi, Erte; Patel, Amish J

2018-04-05

The solubility of proteins and other macromolecular solutes plays an important role in numerous biological, chemical, and medicinal processes. An important determinant of protein solubility is the solvation free energy of the protein, which quantifies the overall strength of the interactions between the protein and the aqueous solution that surrounds it. Here we present an all-atom explicit-solvent computational framework for the rapid estimation of protein solvation free energies. Using this framework, we estimate the hydration free energy of hydrophobin II, an amphiphilic fungal protein, in a computationally efficient manner. We further explore how the protein hydration free energy is influenced by enhancing flexibility and by the addition of sodium chloride, and find that it increases in both cases, making protein hydration less favorable.

Secondary ion emission from arachidic acid LB-layers under Ar +, Xe +, Ga + and SF 5+ primary ion bombardment

NASA Astrophysics Data System (ADS)

Stapel, D.; Brox, O.; Benninghoven, A.

1999-02-01

The influence of primary ion energy, mass and composition on sputtering and secondary ion emission of arachidic acid Langmuir-Blodgett mono- and multilayers, deposited on gold substrates, has been investigated. Ga +, Ar +, 129Xe+ and SF 5+ in the energy range 5-25 keV were used as primary ions. Yields Y, damage cross-sections σ, and ion formation efficiencies E have been determined for selected secondary ions, characterizing the molecular overlayer, the overlayer substrate interface and the substrate. We found a strong influence of layer thickness and of primary ion energy, mass and composition on Y, σ and E. Information depth increases with increasing ion energy and decreasing mass of primary ions, being higher for SF 5+ than for Xe +. Y, σ and E increase with increasing primary ion mass. They are considerably higher for a molecular (SF 5+) than for atomic ions of comparable mass ( 129Xe+). The experimental results supply information on the extension of impact cascades, generated in different substrate materials by different primary ion species and different energies. They demonstrate that in analytical SIMS application information depths can be minimized and yields and ion formation efficiencies can be maximized by the use of molecular primary ions.

Towards explaining the health impacts of residential energy efficiency interventions - A realist review. Part 1: Pathways.

PubMed

Willand, Nicola; Ridley, Ian; Maller, Cecily

2015-05-01

This paper is Part 1 of a realist review that tries to explain the impacts of residential energy efficiency interventions (REEIs) on householder health. According to recent systematic reviews residential energy efficiency interventions may benefit health. It is argued that home energy improvement are complex interventions and that a better understanding of the latent mechanisms and contextual issues that may shape the outcome of interventions is needed for effective intervention design. This realist review synthesises the results of 28 energy efficiency improvement programmes. This first part provides a review of the explanatory factors of the three key pathways, namely warmth in the home, affordability of fuel and psycho-social factors, and the pitfall of inadequate indoor air quality. The review revealed that REEIs improved winter warmth and lowered relative humidity with benefits for cardiovascular and respiratory health. In addition, residential energy efficiency improvements consolidated the meaning of the home as a safe haven, strengthened the householder's perceived autonomy and enhanced social status. Although satisfaction with the home proved to be an important explanation for positive mental health outcomes, financial considerations seemed to have played a secondary role. Evidence for negative impacts was rare but the risk should not be dismissed. Comprehensive refurbishments were not necessarily more effective than thermal retrofits or upgrades. A common protocol for the quantitative and qualitative evaluation of interventions would facilitate the synthesis of future studies. Householder and contextual influences are addressed in Part 2. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mathematical Modeling of Radiofrequency Ablation for Varicose Veins

PubMed Central

Choi, Sun Young; Kwak, Byung Kook

2014-01-01

We present a three-dimensional mathematical model for the study of radiofrequency ablation (RFA) with blood flow for varicose vein. The model designed to analyze temperature distribution heated by radiofrequency energy and cooled by blood flow includes a cylindrically symmetric blood vessel with a homogeneous vein wall. The simulated blood velocity conditions are U = 0, 1, 2.5, 5, 10, 20, and 40 mm/s. The lower the blood velocity, the higher the temperature in the vein wall and the greater the tissue damage. The region that is influenced by temperature in the case of the stagnant flow occupies approximately 28.5% of the whole geometry, while the region that is influenced by temperature in the case of continuously moving electrode against the flow direction is about 50%. The generated RF energy induces a temperature rise of the blood in the lumen and leads to an occlusion of the blood vessel. The result of the study demonstrated that higher blood velocity led to smaller thermal region and lower ablation efficiency. Since the peak temperature along the venous wall depends on the blood velocity and pullback velocity, the temperature distribution in the model influences ablation efficiency. The vein wall absorbs more energy in the low pullback velocity than in the high one. PMID:25587351

Simulation of the outdoor energy efficiency of an autonomous solar kit based on meteorological data for a site in Central Europa

NASA Astrophysics Data System (ADS)

Bouzaki, Mohammed Moustafa; Chadel, Meriem; Benyoucef, Boumediene; Petit, Pierre; Aillerie, Michel

2016-07-01

This contribution analyzes the energy provided by a solar kit dedicated to autonomous usage and installed in Central Europa (Longitude 6.10°; Latitude 49.21° and Altitude 160 m) by using the simulation software PVSYST. We focused the analysis on the effect of temperature and solar irradiation on the I-V characteristic of a commercial PV panel. We also consider in this study the influence of charging and discharging the battery on the generator efficiency. Meteorological data are integrated into the simulation software. As expected, the solar kit provides an energy varying all along the year with a minimum in December. In the proposed approach, we consider this minimum as the lowest acceptable energy level to satisfy the use. Thus for the other months, a lost in the available renewable energy exists if no storage system is associated.

Research on Factors Influencing Individual's Behavior of Energy Management

NASA Astrophysics Data System (ADS)

Fan, Yanfeng

With the rapid rise of distributed generation, Internet of Things, and mobile Internet, both U.S. and European smart home manufacturers have developed energy management solutions for individual usage. These applications help people manage their energy consumption more efficiently. Domestic manufacturers have also launched similar products. This paper focuses on the factors influencing Energy Management Behaviour (EMB) at the individual level. By reviewing academic literature, conducting surveys in Beijing, Shanghai and Guangzhou, the author builds an integrated behavioural energy management model of the Chinese energy consumers. This paper takes the vague term of EMB and redefines it as a function of two separate behavioural concepts: Energy Management Intention (EMI), and the traditional Energy Saving Intention (ESI). Secondly, the author conducts statistical analyses on these two behavioural concepts. EMI is the main driver behind an individual's EMB. EMI is affected by Behavioural Attitudes, Subjective Norms, and Perceived Behavioural Control (PBC). Among these three key factors, PBC exerts the strongest influence. This implies that the promotion of the energy management concept is mainly driven by good application user experience (UX). The traditional ESI also demonstrates positive influence on EMB, but its impact is weaker than the impacts arising under EMI's three factors. In other words, the government and manufacturers may not be able to change an individual's energy management behaviour if they rely solely on their traditional promotion strategies. In addition, the study finds that the government may achieve better promotional results by launching subsidies to the manufacturers of these kinds of applications and smart appliances.

Feed efficiency of diets with different energy and protein concentrations supplemented with methionine in laying quails

NASA Astrophysics Data System (ADS)

Ratriyanto, A.; Indreswari, R.; Nuhriawangsa, A. M. P.; Purwanti, E.

2018-03-01

The study was conducted to evaluate the feed efficiency of quail diets containing different concentrations of metabolizable energy (ME) and crude protein (CP) with constant ratio and supplemented with methionine. Four hundred laying quails (Coturnix coturnix japonica) were randomly assigned to four experimental diets in a 2×2 factorial arrangement. Each dietary treatment used 5 replicates of 20 quails. Two basal diets were formulated to contain 2,800 kcal kg-1 ME and 18.7% CP (High ME-CP) and 2,600 kcal kg-1 ME and 17.3% CP (Low ME-CP). Each basal diet was supplemented with 0 and 0.12% methionine. The High ME-CP diets generated lower feed consumption but higher egg mass and feed efficiency (P<0.01) compared with the Low ME-CP. Furthermore, supplementation of methionine increased egg mass, feed efficiency, energy efficiency ratio and protein efficiency ratio (P<0.01). The High ME-CP supplemented with methionine resulted the highest feed efficiency followed by the Low ME-CP supplemented with methionine, while both High ME-CP and Low ME-CP without methionine supplementation resulted the lowest feed efficiency (P<0.05). In addition, ME and CP consumption of the birds were not influenced by the treatments. Thus, feeding High ME-CP supplemented with 0.12% methionine provided benefit to improve the feed efficiency in laying quails.

An assessment of the influence of macronutrients on growth performance and nutrient utilisation in broiler chickens by nutritional geometry.

PubMed

Liu, Sonia Y; Selle, Peter H; Raubenheimer, David; Cadogan, David J; Simpson, Stephen J; Cowieson, Aaron J

2016-12-01

The right-angled triangle mixture experiment was designed to include fourteen diets with different concentrations of starch, protein and lipid. Experimental diets were offered to male Ross 308 broiler chickens from 10 to 23 d after hatching, and response curves and surfaces were generated to illustrate the influence of macronutrients on growth performance and nutrient utilisations. Despite the primary function of macronutrients, especially protein, may not be providing energy, macronutrients were expressed as energy derived from starch, protein and fat for statistical purposes in the mixture design. Energy derived from lipid had a greater impact on feed intake than energy derived from starch and protein. When we compared the influence of starch and protein on feed intake, 'equal distance rule' was observed, which means the animal consumes feed to the point on its respective nutritional rails where the shortage of starch exactly equals the surplus of consumed protein. Increasing the protein-derived energy intake increased weight gain in broiler chickens, whereas energy intake derived from starch and lipid had little impact on weight gain. Feed conversion ratio (FCR) may be reduced by either increasing protein energy intake or decreasing starch energy intake. As the slope of the contours was less than 1, the influence of starch energy intakes on FCR exceeded that of protein energy intakes. In conclusion, energy derived from protein is more important than non-protein energy in terms of weight gain, and a balance between protein and energy supplies is required for efficient muscle protein deposition.

The roles of users in shaping transitions to new energy systems

NASA Astrophysics Data System (ADS)

Schot, Johan; Kanger, Laur; Verbong, Geert

2016-05-01

Current government information policies and market-based instruments aimed at influencing the energy choices of consumers often ignore the fact that consumer behaviour is not fully reducible to individuals making rational conscious decisions all the time. The decisions of consumers are largely configured by shared routines embedded in socio-technical systems. To achieve a transition towards a decarbonized and energy-efficient system, an approach that goes beyond individual consumer choice and puts shared routines and system change at its centre is needed. Here, adopting a transitions perspective, we argue that consumers should be reconceptualized as users who are important stakeholders in the innovation process shaping new routines and enacting system change. We review the role of users in shifts to new decarbonized and energy-efficient systems and provide a typology of user roles.

Energy Savings Through Thermally Efficient Crucible Technology: Fundamentals, Process Modeling, and Applications

NASA Astrophysics Data System (ADS)

Shi, Wenwu; Pinto, Brian

2017-12-01

Melting and holding molten metals within crucibles accounts for a large portion of total energy demand in the resource-intensive nonferrous foundry industry. Multivariate mathematical modeling aided by detailed material characterization and advancements in crucible technologies can make a significant impact in the areas of cost-efficiency and carbon footprint reduction. Key thermal properties such as conductivity and specific heat capacity were studied to understand their influence on crucible furnace energy consumption during melting and holding processes. The effects of conductivity on thermal stresses and longevity of crucibles were also evaluated. With this information, accurate theoretical models using finite element analysis were developed to study total energy consumption and melting time. By applying these findings to recent crucible developments, considerable improvements in field performance were reported and documented as case studies in applications such as aluminum melting and holding.

Use of Energy-Efficient Technologies: U.S. Marine Corps Perceptions to Adoption

DTIC Science & Technology

2013-12-01

Hierarchy ..............................18 E. COMMONALITIES IN THEORIES ..........................................................20 F. WATKINS ...111 ix LIST OF FIGURES Figure 1. Influence Campaigns (from Watkins , 2003...Figure 6. Research Framework (after Watkins , 2003) ....................................................22 Figure 7. Focus Group Participant Demographic

Opening Up New Possibilities.

ERIC Educational Resources Information Center

Kennedy, Mike

2001-01-01

Discusses technology's impact on educational facilities and operations. Technology's influence on a school's ability to streamline their business operations and manage their facilities more efficiency is examined, and how Baylor University (Waco, TX) used technology to cut energy costs is highlighted. (GR)

Modelling the link amongst fine-pore diffuser fouling, oxygen transfer efficiency, and aeration energy intensity.

PubMed

Garrido-Baserba, Manel; Sobhani, Reza; Asvapathanagul, Pitiporn; McCarthy, Graham W; Olson, Betty H; Odize, Victory; Al-Omari, Ahmed; Murthy, Sudhir; Nifong, Andrea; Godwin, Johnnie; Bott, Charles B; Stenstrom, Michael K; Shaw, Andrew R; Rosso, Diego

2017-03-15

This research systematically studied the behavior of aeration diffuser efficiency over time, and its relation to the energy usage per diffuser. Twelve diffusers were selected for a one year fouling study. Comprehensive aeration efficiency projections were carried out in two WRRFs with different influent rates, and the influence of operating conditions on aeration diffusers' performance was demonstrated. This study showed that the initial energy use, during the first year of operation, of those aeration diffusers located in high rate systems (with solids retention time - SRT-less than 2 days) increased more than 20% in comparison to the conventional systems (2 > SRT). Diffusers operating for three years in conventional systems presented the same fouling characteristics as those deployed in high rate processes for less than 15 months. A new procedure was developed to accurately project energy consumption on aeration diffusers; including the impacts of operation conditions, such SRT and organic loading rate, on specific aeration diffusers materials (i.e. silicone, polyurethane, EPDM, ceramic). Furthermore, it considers the microbial colonization dynamics, which successfully correlated with the increase of energy consumption (r 2 :0.82 ± 7). The presented energy model projected the energy costs and the potential savings for the diffusers after three years in operation in different operating conditions. Whereas the most efficient diffusers provided potential costs spanning from 4900 USD/Month for a small plant (20 MGD, or 74,500 m 3 /d) up to 24,500 USD/Month for a large plant (100 MGD, or 375,000 m 3 /d), other diffusers presenting less efficiency provided spans from 18,000USD/Month for a small plant to 90,000 USD/Month for large plants. The aim of this methodology is to help utilities gain more insight into process mechanisms and design better energy efficiency strategies at existing facilities to reduce energy consumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

Underground Pumped Storage Hydropower using abandoned open pit mines: influence of groundwater seepage on the system efficiency

NASA Astrophysics Data System (ADS)

Pujades, Estanislao; Bodeux, Sarah; Orban, Philippe; Dassargues, Alain

2016-04-01

Pumped Storage Hydropower (PSH) plants can be used to manage the production of electrical energy according to the demand. These plants allow storing and generating electricity during low and high demand energy periods, respectively. Nevertheless, PSH plants require a determined topography because two reservoirs located at different heights are needed. At sites where PSH plants cannot be constructed due to topography requirements (flat regions), Underground Pumped Storage Hydropower (UPSH) plants can be used to adjust the electricity production. These plants consist in two reservoirs, the upper one is located at the surface (or at shallow depth) while the lower one is underground (or deeper). Abandoned open pit mines can be used as lower reservoirs but these are rarely isolated. As a consequence, UPSH plants will interact with surrounding aquifers exchanging groundwater. Groundwater seepage will modify hydraulic head inside the underground reservoir affecting global efficiency of the UPSH plant. The influence on the plant efficiency caused by the interaction between UPSH plants and aquifers will depend on the aquifer parameters, underground reservoir properties and pumping and injection characteristics. The alteration of the efficiency produced by the groundwater exchanges, which has not been previously considered, is now studied numerically. A set of numerical simulations are performed to establish in terms of efficiency the effects of groundwater exchanges and the optimum conditions to locate an UPSH plant.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christensen, C.; Horowitz, S.

In subdivisions, house orientations are largely determined by street layout. The resulting house orientations affect energy consumption (annual and on-peak) for heating and cooling, depending on window area distributions and shading from neighboring houses. House orientations also affect energy production (annual and on-peak) from solar thermal and photovoltaic systems, depending on available roof surfaces. Therefore, house orientations fundamentally influence both energy consumption and production, and an appropriate street layout is a prerequisite for taking full advantage of energy efficiency and renewable energy opportunities. The potential influence of street layout on solar performance is often acknowledged, but solar and energy issuesmore » must compete with many other criteria and constraints that influence subdivision street layout. When only general guidelines regarding energy are available, these factors may be ignored or have limited effect. Also, typical guidelines are often not site-specific and do not account for local parameters such as climate and the time value of energy. For energy to be given its due consideration in subdivision design, energy impacts need to be accurately quantified and displayed interactively to facilitate analysis of design alternatives. This paper describes a new computerized Subdivision Energy Analysis Tool being developed to allow users to interactively design subdivision street layouts while receiving feedback about energy impacts based on user-specified building design variants and availability of roof surfaces for photovoltaic and solar water heating systems.« less

GHG Effect on Surface Temperature in Indonesia

NASA Astrophysics Data System (ADS)

Cahyono, W. E.

The increasing of green house gas emissons into the atmosphere could influence the Climate and Earth Ecosystem. The increasing CO_2 emmision in developed countries and developing countries are influenced by economic growth factor, cheaped price fuel without tax and there is not regulation yet for making arrangement energy efficiency. The result of inventarisation CO_2 emmision related to energy sector between 1990 until 2000 in Indonesia are having increased trend, and the CO_2 emmision percapita is still lower then OECD countries. The green house gas concentrations are measured continously in Bandung, Jakarta, and the others place. The CO_2 and CH_4 concentration ever had results higher than globally mean. The fluctuation of green house gas concentrations are influenced by activities of surounding research location.

Editorial: Photovoltaic Materials and Devices 2014

DOE PAGES

Sopori, Bhushan; Rupnowski, Peter; Shet, Sudhakar; ...

2014-12-22

An ever increasing demand on energy has fostered many new generation technologies, which include photovoltaics. In recent years, photovoltaic industry has grown very rapidly. The installed capacity of PV for 2013 was about 37 GW and 2014 sales are expected to be around 45 GW. However, there has been excess production for last several years, which is responsible in part for the low prices (about 60 c/W). To lower the PV energy costs further, a major strategy appears to be going to high efficiency solar cells. This approach is favored (over lower cost/lower efficiency) because cell efficiency has a verymore » large influence on the acceptable manufacturing cost of a PV module. Hence, the PV industry is moving toward developing processes and equipment to manufacture solar cells that can yield efficiencies >20%. Therefore, further research is needed within existing technologies to accomplish these objectives. Likewise, research will continue to seek new materials and devices.« less

Integrated application of combined cooling, heating and power poly-generation PV radiant panel system of zero energy buildings

NASA Astrophysics Data System (ADS)

Yin, Baoquan

2018-02-01

A new type of combined cooling, heating and power of photovoltaic radiant panel (PV/R) module was proposed, and applied in the zero energy buildings in this paper. The energy system of this building is composed of PV/R module, low temperature difference terminal, energy storage, multi-source heat pump, energy balance control system. Radiant panel is attached on the backside of the PV module for cooling the PV, which is called PV/R module. During the daytime, the PV module was cooled down with the radiant panel, as the temperature coefficient influence, the power efficiency was increased by 8% to 14%, the radiant panel solar heat collecting efficiency was about 45%. Through the nocturnal radiant cooling, the PV/R cooling capacity could be 50 W/m2. For the multifunction energy device, the system shows the versatility during the heating, cooling and power used of building utilization all year round.

Manned Mars Landing Missions Using Electric Propulsion

DTIC Science & Technology

1966-01-01

U 77= 2 eV 21qý 1200 1+ io 2(I X 9.80665) > 1000 _---where S800- -- 7 thrustor efficiency 600 _ u fraction of propellant ionized -oo - -eV/ion energy ...terminated at escape energy rather than at the sphere of influence. For some of the higher accelera- tions, escape energy is reached some distance inside the...error being about 5 percent of the initial mass. Most doubtful at this time are the accuracies of the planet approach velocity and peri- helion radius

Theoretical investigations of energy harvesting efficiency from structural vibrations using piezoelectric and electromagnetic oscillators.

PubMed

Harne, Ryan L

2012-07-01

Conversion of ambient vibrational energy into electric power has been the impetus of much modern research. The traditional analysis has focused on absolute electrical power output from the harvesting devices and efficiency defined as the convertibility of an infinite resource of vibration excitation into power. This perspective has limited extensibility when applying resonant harvesters to host resonant structures when the inertial influence of the harvester is more significant. Instead, this work pursues a fundamental understanding of the coupled dynamics of a main mass-spring-damper system to which an electromagnetic or piezoelectric mass-spring-damper is attached. The governing equations are derived, a metric of efficiency is presented, and analysis is undertaken. It is found that electromagnetic energy harvesting efficiency and maximum power output is limited by the strength of the coupling such that no split system resonances are induced for a given mass ratio. For piezoelectric harvesters, only the coupling strength and certain design requirements dictate maximum power and efficiency achievable. Since the harvesting circuitry must "follow" the split resonances as the piezoelectric harvesters become more massive, the optimum design of piezoelectric harvesters appears to be more involved than for electromagnetic devices.

Ecological conversion efficiency and its influencers in twelve species of fish in the Yellow Sea Ecosystem

NASA Astrophysics Data System (ADS)

Tang, Qisheng; Guo, Xuewu; Sun, Yao; Zhang, Bo

2007-09-01

The ecological conversion efficiencies in twelve species of fish in the Yellow Sea Ecosystem, i.e., anchovy ( Engraulis japonicus), rednose anchovy ( Thrissa kammalensis), chub mackerel ( Scomber japonicus), halfbeak ( Hyporhamphus sajori), gizzard shad ( Konosirus punctatus), sand lance ( Ammodytes personatus), red seabream ( Pagrus major), black porgy ( Acanthopagrus schlegeli), black rockfish ( Sebastes schlegeli), finespot goby ( Chaeturichthys stigmatias), tiger puffer ( Takifugu rubripes), and fat greenling ( Hexagrammos otakii), were estimated through experiments conducted either in situ or in a laboratory. The ecological conversion efficiencies were significantly different among these species. As indicated, the food conversion efficiencies and the energy conversion efficiencies varied from 12.9% to 42.1% and from 12.7% to 43.0%, respectively. Water temperature and ration level are the main factors influencing the ecological conversion efficiencies of marine fish. The higher conversion efficiency of a given species in a natural ecosystem is acquired only under the moderate environment conditions. A negative relationship between ecological conversion efficiency and trophic level among ten species was observed. Such a relationship indicates that the ecological efficiency in the upper trophic levels would increase after fishing down marine food web in the Yellow Sea ecosystem.

Raising Public Awareness: The Role of the Household Sector in Mitigating Climate Change

PubMed Central

Lin, Shis-Ping

2015-01-01

In addition to greenhouse gas emissions from the industrial, transportation and commercial sectors, emissions from the household sector also contribute to global warming. By examining residents of Taiwan (N = 236), this study aims to reveal the factors that influence households’ intention to purchase energy-efficient appliances. The assessment in this study is based on the theory of planned behavior (TPB), and perceived benefit or cost (BOC) is introduced as an independent variable in the proposed efficiency action toward climate change (ECC) model. According to structural equation modeling, most of the indicators presented a good fit to the corresponding ECC model constructs. The analysis indicated that BOC is a good complementary variable to the TPB, as the ECC model explained 61.9% of the variation in intention to purchase energy-efficient appliances, which was higher than that explained by the TPB (58.4%). This result indicates that the ECC model is superior to the TPB. Thus, the strategy of promoting energy-efficient appliances in the household sector should emphasize global warming and include the concept of BOC. PMID:26492262

Raising Public Awareness: The Role of the Household Sector in Mitigating Climate Change.

PubMed

Lin, Shis-Ping

2015-10-20

In addition to greenhouse gas emissions from the industrial, transportation and commercial sectors, emissions from the household sector also contribute to global warming. By examining residents of Taiwan (N = 236), this study aims to reveal the factors that influence households' intention to purchase energy-efficient appliances. The assessment in this study is based on the theory of planned behavior (TPB), and perceived benefit or cost (BOC) is introduced as an independent variable in the proposed efficiency action toward climate change (ECC) model. According to structural equation modeling, most of the indicators presented a good fit to the corresponding ECC model constructs. The analysis indicated that BOC is a good complementary variable to the TPB, as the ECC model explained 61.9% of the variation in intention to purchase energy-efficient appliances, which was higher than that explained by the TPB (58.4%). This result indicates that the ECC model is superior to the TPB. Thus, the strategy of promoting energy-efficient appliances in the household sector should emphasize global warming and include the concept of BOC.

Energy release for the actuation and deployment of muscle-inspired asymmetrically multistable chains

NASA Astrophysics Data System (ADS)

Kidambi, Narayanan; Zheng, Yisheng; Harne, Ryan L.; Wang, K. W.

2018-03-01

Animal locomotion and movement requires energy, and the elastic potential energy stored in skeletal muscle can facilitate movements that are otherwise energetically infeasible. A significant proportion of this energy is captured and stored in the micro- and nano-scale constituents of muscle near the point of instability between asymmetric equilibrium states. This energy may be quickly released to enable explosive macroscopic motions or to reduce the metabolic cost of cyclic movements. Inspired by these behaviors, this research explores modular metastructures of bistable element chains and develops methods to release the energy stored in higher-potential system configurations. Quasi-static investigations reveal the role of state-transition pathways on the overall efficiency of the deployment event. It is shown that sequential, local release of energy from the bistable elements is more efficient than concurrent energy release achieved by applying a force at the free end of the structure. From dynamic analyses and experiments, it is shown that that the energy released from one bistable element can be used to activate the release of energy from subsequent links, reducing the actuation energy required to extend or deploy the chain below that required for quasi-static deployment. This phenomenon is influenced by the level of asymmetry in the bistable constituents and the location of the impulse that initiates the deployment of the structure. The results provide insight into the design and behavior of asymmetrically multistable chains that can leverage stored potential energy to enable efficient and effective system deployment and length change.

Role of surface energy and nano-roughness in the removal efficiency of bacterial contamination by nonwoven wipes from frequently touched surfaces

NASA Astrophysics Data System (ADS)

Edwards, Nicholas W. M.; Best, Emma L.; Connell, Simon D.; Goswami, Parikshit; Carr, Chris M.; Wilcox, Mark H.; Russell, Stephen J.

2017-12-01

Healthcare associated infections (HCAIs) are responsible for substantial patient morbidity, mortality and economic cost. Infection control strategies for reducing rates of transmission include the use of nonwoven wipes to remove pathogenic bacteria from frequently touched surfaces. Wiping is a dynamic process that involves physicochemical mechanisms to detach and transfer bacteria to fibre surfaces within the wipe. The purpose of this study was to determine the extent to which systematic changes in fibre surface energy and nano-roughness influence removal of bacteria from an abiotic polymer surface in dry wiping conditions, without liquid detergents or disinfectants. Nonwoven wipe substrates composed of two commonly used fibre types, lyocell (cellulosic) and polypropylene, with different surface energies and nano-roughnesses, were manufactured using pilot-scale nonwoven facilities to produce samples of comparable structure and dimensional properties. The surface energy and nano-roughness of some lyocell substrates were further adjusted by either oxygen (O2) or hexafluoroethane (C2F6) gas plasma treatment. Static adpression wiping of an inoculated surface under dry conditions produced removal efficiencies of between 9.4% and 15.7%, with no significant difference (p < 0.05) in the relative removal efficiencies of Escherichia coli, Staphylococcus aureus or Enterococcus faecalis. However, dynamic wiping markedly increased peak wiping efficiencies to over 50%, with a minimum increase in removal efficiency of 12.5% and a maximum increase in removal efficiency of 37.9% (all significant at p < 0.05) compared with static wiping, depending on fibre type and bacterium. In dry, dynamic wiping conditions, nonwoven wipe substrates with a surface energy closest to that of the contaminated surface produced the highest E. coli removal efficiency, while the associated increase in fibre nano-roughness abrogated this trend with S. aureus and E. faecalis.

Slow-light-enhanced energy efficiency for graphene microheaters on silicon photonic crystal waveguides

PubMed Central

Yan, Siqi; Zhu, Xiaolong; Frandsen, Lars Hagedorn; Xiao, Sanshui; Mortensen, N. Asger; Dong, Jianji; Ding, Yunhong

2017-01-01

Slow light has been widely utilized to obtain enhanced nonlinearities, enhanced spontaneous emissions and increased phase shifts owing to its ability to promote light–matter interactions. By incorporating a graphene on a slow-light silicon photonic crystal waveguide, here we experimentally demonstrate an energy-efficient graphene microheater with a tuning efficiency of 1.07 nmmW−1 and power consumption per free spectral range of 3.99 mW. The rise and decay times (10–90%) are only 750 and 525 ns, which, to the best of our knowledge, are the fastest reported response times for microheaters in silicon photonics. The corresponding figure of merit of the device is 2.543 nW s, one order of magnitude better than results reported in previous studies. The influence of the length and shape of the graphene heater to the tuning efficiency is further investigated, providing valuable guidelines for enhancing the tuning efficiency of the graphene microheater. PMID:28181531

Assessing National Employment Impacts of Investment in Residential and Commercial Sector Energy Efficiency: Review and Example Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, David M.; Belzer, David B.; Livingston, Olga V.

Pacific Northwest National Laboratory (PNNL) modeled the employment impacts of a major national initiative to accelerate energy efficiency trends at one of two levels: • 15 percent savings by 2030. In this scenario, efficiency activities save about 15 percent of the Annual Energy Outlook (AEO) Reference Case electricity consumption by 2030. It is assumed that additional energy savings in both the residential and commercial sectors begin in 2015 at zero, and then increase in an S-shaped market penetration curve, with the level of savings equal to about 7.0 percent of the AEO 2014 U.S. national residential and commercial electricity consumptionmore » saved by 2020, 14.8 percent by 2025, and 15 percent by 2030. • 10 percent savings by 2030. In this scenario, additional savings begin at zero in 2015, increase to 3.8 percent in 2020, 9.8 percent by 2025, and 10 percent of the AEO reference case value by 2030. The analysis of the 15 percent case indicates that by 2030 more than 300,000 new jobs would likely result from such policies, including an annual average of more than 60,000 jobs directly supporting the installation and maintenance of energy efficiency measures and practices. These are new jobs resulting initially from the investment associated with the construction of more energy-efficient new buildings or the retrofit of existing buildings and would be sustained for as long as the investment continues. Based on what is known about the current level of building-sector energy efficiency jobs, this would represent an increase of more than 10 percent from the current estimated level of over 450,000 such jobs. The more significant and longer-lasting effect comes from the redirection of energy bill savings toward the purchase of other goods and services in the general economy, with its attendant influence on increasing the total number of jobs. This example analysis utilized PNNL’s ImSET model, a modeling framework that PNNL has used over the past two decades to assess the economic impacts of the U.S. Department of Energy’s (DOE’s) energy efficiency programs in the buildings sector.« less

Influence of temperature and electrolyte on the performance of activated-carbon supercapacitors

NASA Astrophysics Data System (ADS)

Liu, Ping; Verbrugge, Mark; Soukiazian, Souren

For hybrid electric vehicle traction applications, energy storage devices with high power density and energy efficiency are required. A primary attribute of supercapacitors is that they retain their high power density and energy efficiency even at -30 °C, the lowest temperature at which unassisted starting must be provided to customers. More abuse-tolerant electrolytes are preferred to the high-conductivity acetonitrile-based systems commonly employed. Propylene carbonate based electrolytes are a promising alternative. In this work, we compare the electrochemical performance of two high-power density electrical double layer supercapacitors employing acetonitrile and propylene carbonate as solvents. From this study, we are able to elucidate phenomena that control the resistance of supercapacitor at lower temperatures, and quantify the difference in performance associated with the two electrolytes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dernotte, Jeremie; Dec, John E.; Ji, Chunsheng

A detailed understanding of the various factors affecting the trends in gross-indicated thermal efficiency with changes in key operating parameters has been carried out, applied to a one-liter displacement single-cylinder boosted Low-Temperature Gasoline Combustion (LTGC) engine. This work systematically investigates how the supplied fuel energy splits into the following four energy pathways: gross-indicated thermal efficiency, combustion inefficiency, heat transfer and exhaust losses, and how this split changes with operating conditions. Additional analysis is performed to determine the influence of variations in the ratio of specific heat capacities (γ) and the effective expansion ratio, related to the combustion-phasing retard (CA50), onmore » the energy split. Heat transfer and exhaust losses are computed using multiple standard cycle analysis techniques. Furthermore, the various methods are evaluated in order to validate the trends.« less

Free energy calculations: an efficient adaptive biasing potential method.

PubMed

Dickson, Bradley M; Legoll, Frédéric; Lelièvre, Tony; Stoltz, Gabriel; Fleurat-Lessard, Paul

2010-05-06

We develop an efficient sampling and free energy calculation technique within the adaptive biasing potential (ABP) framework. By mollifying the density of states we obtain an approximate free energy and an adaptive bias potential that is computed directly from the population along the coordinates of the free energy. Because of the mollifier, the bias potential is "nonlocal", and its gradient admits a simple analytic expression. A single observation of the reaction coordinate can thus be used to update the approximate free energy at every point within a neighborhood of the observation. This greatly reduces the equilibration time of the adaptive bias potential. This approximation introduces two parameters: strength of mollification and the zero of energy of the bias potential. While we observe that the approximate free energy is a very good estimate of the actual free energy for a large range of mollification strength, we demonstrate that the errors associated with the mollification may be removed via deconvolution. The zero of energy of the bias potential, which is easy to choose, influences the speed of convergence but not the limiting accuracy. This method is simple to apply to free energy or mean force computation in multiple dimensions and does not involve second derivatives of the reaction coordinates, matrix manipulations nor on-the-fly adaptation of parameters. For the alanine dipeptide test case, the new method is found to gain as much as a factor of 10 in efficiency as compared to two basic implementations of the adaptive biasing force methods, and it is shown to be as efficient as well-tempered metadynamics with the postprocess deconvolution giving a clear advantage to the mollified density of states method.

Exchange-correlation energies of atoms from efficient density functionals: influence of the electron density

DOE PAGES

Tao, Jianmin; Ye, Lin -Hui; Duan, Yuhua

2017-11-20

The primary goal of Kohn–Sham density functional theory is to evaluate the exchange-correlation contribution to electronic properties. However, the accuracy of a density functional can be affected by the electron density. Here we apply the nonempirical Tao–Mo (TM) semilocal functional to study the influence of the electron density on the exchange and correlation energies of atoms and ions, and compare the results with the commonly used nonempirical semilocal functionals local spin-density approximation (LSDA), Perdew–Burke–Ernzerhof (PBE), Tao–Perdew–Staroverov–Scuseria (TPSS), and hybrid functional PBE0. We find that the spin-restricted Hartree–Fock density yields the exchange and correlation energies in good agreement with the Optimizedmore » Effective Potential method, particularly for spherical atoms and ions. However, the errors of these semilocal and hybrid functionals become larger for self-consistent densities. We further find that the quality of the electron density have greater effect on the exchange-correlation energies of kinetic energy density-dependent meta-GGA functionals TPSS and TM than on those of the LSDA and GGA, and therefore, should have greater influence on the performance of meta-GGA functionals. Lastly, we show that the influence of the density quality on PBE0 is slightly reduced, compared to that of PBE, due to the exact mixing.« less

Exchange-correlation energies of atoms from efficient density functionals: influence of the electron density

NASA Astrophysics Data System (ADS)

Tao, Jianmin; Ye, Lin-Hui; Duan, Yuhua

2017-12-01

The primary goal of Kohn-Sham density functional theory is to evaluate the exchange-correlation contribution to electronic properties. However, the accuracy of a density functional can be affected by the electron density. Here we apply the nonempirical Tao-Mo (TM) semilocal functional to study the influence of the electron density on the exchange and correlation energies of atoms and ions, and compare the results with the commonly used nonempirical semilocal functionals local spin-density approximation (LSDA), Perdew-Burke-Ernzerhof (PBE), Tao-Perdew-Staroverov-Scuseria (TPSS), and hybrid functional PBE0. We find that the spin-restricted Hartree-Fock density yields the exchange and correlation energies in good agreement with the Optimized Effective Potential method, particularly for spherical atoms and ions. However, the errors of these semilocal and hybrid functionals become larger for self-consistent densities. We further find that the quality of the electron density have greater effect on the exchange-correlation energies of kinetic energy density-dependent meta-GGA functionals TPSS and TM than on those of the LSDA and GGA, and therefore, should have greater influence on the performance of meta-GGA functionals. Finally, we show that the influence of the density quality on PBE0 is slightly reduced, compared to that of PBE, due to the exact mixing.

Exchange-correlation energies of atoms from efficient density functionals: influence of the electron density

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tao, Jianmin; Ye, Lin -Hui; Duan, Yuhua

The primary goal of Kohn–Sham density functional theory is to evaluate the exchange-correlation contribution to electronic properties. However, the accuracy of a density functional can be affected by the electron density. Here we apply the nonempirical Tao–Mo (TM) semilocal functional to study the influence of the electron density on the exchange and correlation energies of atoms and ions, and compare the results with the commonly used nonempirical semilocal functionals local spin-density approximation (LSDA), Perdew–Burke–Ernzerhof (PBE), Tao–Perdew–Staroverov–Scuseria (TPSS), and hybrid functional PBE0. We find that the spin-restricted Hartree–Fock density yields the exchange and correlation energies in good agreement with the Optimizedmore » Effective Potential method, particularly for spherical atoms and ions. However, the errors of these semilocal and hybrid functionals become larger for self-consistent densities. We further find that the quality of the electron density have greater effect on the exchange-correlation energies of kinetic energy density-dependent meta-GGA functionals TPSS and TM than on those of the LSDA and GGA, and therefore, should have greater influence on the performance of meta-GGA functionals. Lastly, we show that the influence of the density quality on PBE0 is slightly reduced, compared to that of PBE, due to the exact mixing.« less

Influence of silver nanoparticles on relaxation processes and efficiency of dipole – dipole energy transfer between dye molecules in polymethylmethacrylate films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryukhanov, V V; Borkunov, R Yu; Tsarkov, M V

The fluorescence and phosphorescence of dyes in thin polymethylmethacrylate (PMMA) films in the presence of ablated silver nanoparticles has been investigated in a wide temperature range by methods of femtosecond and picosecond laser photoexcitation. The fluorescence and phosphorescence times, as well as spectral and kinetic characteristics of rhodamine 6G (R6G) molecules in PMMA films are measured in a temperature range of 80 – 330 K. The temperature quenching activation energy of the fluorescence of R6G molecules in the presence of ablated silver nanoparticles is found. The vibrational relaxation rate of R6G in PMMA films is estimated, the efficiency of themore » dipole – dipole electron energy transfer between R6G and brilliant green molecules (enhanced by plasmonic interaction with ablated silver nanoparticles) is analysed, and the constants of this energy transfer are determined. (nanophotonics)« less

Plant-microbe genomic systems optimization for energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hazen, Samuel P.

The overall objective of this project was to identify genetic variation within grasses that results in increased biomass yield and biofuel conversion efficiency. Improving energy crops hinges on identifying the genetic mechanisms underlying traits that benefit energy production. The exploitation of natural variation in plant species is an ideal approach to identify both the traits and the genes of interest in the production of biofuels. The specific goals of this project were to (1) quantify relevant genetic diversity for biofuel feedstock bioconversion efficiency and biomass accumulation, (2) identify genetic loci that control these traits, and (3) characterize genes for improvedmore » energy crop systems. Determining the key genetic contributors influencing biofuel traits is required in order to determine the viability of these traits as targets for improvement; only then will we be able to apply modern breeding practices and genetic engineering for the rapid improvement of feedstocks.« less

The Effects of Triggering Mechanisms on the Energy Absorption Capability of Circular Jute/Epoxy Composite Tubes under Quasi-Static Axial Loading

NASA Astrophysics Data System (ADS)

Sivagurunathan, Rubentheran; Lau Tze Way, Saijod; Sivagurunathan, Linkesvaran; Yaakob, Mohd. Yuhazri

2018-01-01

The usage of composite materials have been improving over the years due to its superior mechanical properties such as high tensile strength, high energy absorption capability, and corrosion resistance. In this present study, the energy absorption capability of circular jute/epoxy composite tubes were tested and evaluated. To induce the progressive crushing of the composite tubes, four different types of triggering mechanisms were used which were the non-trigger, single chamfered trigger, double chamfered trigger and tulip trigger. Quasi-static axial loading test was carried out to understand the deformation patterns and the load-displacement characteristics for each composite tube. Besides that, the influence of energy absorption, crush force efficiency, peak load, mean load and load-displacement history were examined and discussed. The primary results displayed a significant influence on the energy absorption capability provided that stable progressive crushing occurred mostly in the triggered tubes compared to the non-triggered tubes. Overall, the tulip trigger configuration attributed the highest energy absorption.

Influence of the chemical surface structure on the nanoscale friction in plasma nitrided and post-oxidized ferrous alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freislebem, Márcia; Menezes, Caren M.; Cemin, Felipe

2014-09-15

Friction is a ubiquitous phenomenon in everyday activities spanning from vehicles where efficient brakes are mandatory up to mechanical devices where its minimum effects are pursued for energy efficiency issues. Recently, theoretical models succeed correlating the friction behavior with energy transference via phonons between sliding surfaces. Therefore, considering that the energy losses by friction are prompted through phonons, the chemical surface structure between sliding surfaces is very important to determine the friction phenomenon. In this work, we address the issue of friction between a conical diamond tip sliding on different functionalized flat steel surfaces by focusing the influence of themore » chemical bonds in the outermost layers on the sliding resistance. This geometry allows probing the coupling of the sharp tip with terminator species on the top and underneath material surface at in-depth friction measurements from 20 to 200 nm. Experimentally, the friction coefficient decreases when nitrogen atoms are substituted for oxygen in the iron network. This effect is interpreted as due to energy losses through phonons whilst lower vibrational frequency excitation modes imply lower friction coefficients and a more accurate adjustment is obtained when a theoretical model with longitudinal adsorbate vibration is used.« less

Software augmented buildings: Exploiting existing infrastructure to improve energy efficiency and comfort in commercial buildings

NASA Astrophysics Data System (ADS)

Balaji, Bharathan

Commercial buildings consume 19% of energy in the US as of 2010, and traditionally, their energy use has been optimized through improved equipment efficiency and retrofits. Beyond improved hardware and infrastructure, there exists a tremendous potential in reducing energy use through better monitoring and operation. We present several applications that we developed and deployed to support our thesis that building energy use can be reduced through sensing, monitoring and optimization software that modulates use of building subsystems including HVAC. We focus on HVAC systems as these constitute 48-55% of building energy use. Specifically, in case of sensing, we describe an energy apportionment system that enables us to estimate real-time zonal HVAC power consumption by analyzing existing sensor information. With this energy breakdown, we can measure effectiveness of optimization solutions and identify inefficiencies. Central to energy efficiency improvement is determination of human occupancy in buildings. But this information is often unavailable or expensive to obtain using wide scale sensor deployment. We present our system that infers room level occupancy inexpensively by leveraging existing WiFi infrastructure. Occupancy information can be used not only to directly control HVAC but also to infer state of the building for predictive control. Building energy use is strongly influenced by human behaviors, and timely feedback mechanisms can encourage energy saving behavior. Occupants interact with HVAC using thermostats which has shown to be inadequate for thermal comfort. Building managers are responsible for incorporating energy efficiency measures, but our interviews reveal that they struggle to maintain efficiency due to lack of analytical tools and contextual information. We present our software services that provide energy feedback to occupants and building managers, improves comfort with personalized control and identifies energy wasting faults. For wide scale deployment of such energy saving software, they need to be portable across multiple buildings. However, buildings consist of heterogeneous equipment and use inconsistent naming schema, and developers need extensive domain knowledge to map sensor information to a standard format. To enable portability, we present an active learning algorithm that automates mapping building sensor metadata to a standard naming schema.

Dynamics of ultrasonic additive manufacturing.

PubMed

Hehr, Adam; Dapino, Marcelo J

2017-01-01

Ultrasonic additive manufacturing (UAM) is a solid-state technology for joining similar and dissimilar metal foils near room temperature by scrubbing them together with ultrasonic vibrations under pressure. Structural dynamics of the welding assembly and work piece influence how energy is transferred during the process and ultimately, part quality. To understand the effect of structural dynamics during UAM, a linear time-invariant model is proposed to relate the inputs of shear force and electric current to resultant welder velocity and voltage. Measured frequency response and operating performance of the welder under no load is used to identify model parameters. Using this model and in-situ measurements, shear force and welder efficiency are estimated to be near 2000N and 80% when welding Al 6061-H18 weld foil, respectively. Shear force and welder efficiency have never been estimated before in UAM. The influence of processing conditions, i.e., welder amplitude, normal force, and weld speed, on shear force and welder efficiency are investigated. Welder velocity was found to strongly influence the shear force magnitude and efficiency while normal force and weld speed showed little to no influence. The proposed model is used to describe high frequency harmonic content in the velocity response of the welder during welding operations and coupling of the UAM build with the welder. Copyright © 2016 Elsevier B.V. All rights reserved.

Electrokinetic energy conversion efficiency of viscoelastic fluids in a polyelectrolyte-grafted nanochannel.

PubMed

Jian, Yongjun; Li, Fengqin; Liu, Yongbo; Chang, Long; Liu, Quansheng; Yang, Liangui

2017-08-01

In order to conduct extensive investigation of energy harvesting capabilities of nanofluidic devices, we provide analytical solutions for streaming potential and electrokinetic energy conversion (EKEC) efficiency through taking the combined consequences of soft nanochannel, a rigid nanochannel whose surface is covered by charged polyelectrolyte layer, and viscoelastic rheology into account. The viscoelasticity of the fluid is considered by employing the Maxwell constitutive model when the forcing frequency of an oscillatory driving pressure flow matches with the inverse of the relaxation time scale of a typical viscoelastic fluid. We compare the streaming potential and EKEC efficiency with those of a rigid nanochannel, having zeta potential equal to the electrostatic potential at the solid-polyelectrolyte interface of the soft nanochannels. Within the present selected parameter ranges, it is shown that the different peaks of maximal streaming potential and EKEC efficiency for the rigid nanochannel are larger than those for the soft nanochannel when forcing frequencies of the driving pressure gradient are close to resonating frequencies. However, more enhanced streaming potential and EKEC efficiency for a soft nanochannel can be found in most of the regions away from these resonant frequencies. Moreover, the influence of several dimensionless parameters on EKEC efficiency is discussed in detail. Finally, within the given parametric regions, the maximum efficiency at some resonant frequency obtained in present analysis is about 25%. Copyright © 2017 Elsevier B.V. All rights reserved.

Integrated thermal and energy management of plug-in hybrid electric vehicles

NASA Astrophysics Data System (ADS)

Shams-Zahraei, Mojtaba; Kouzani, Abbas Z.; Kutter, Steffen; Bäker, Bernard

2012-10-01

In plug-in hybrid electric vehicles (PHEVs), the engine temperature declines due to reduced engine load and extended engine off period. It is proven that the engine efficiency and emissions depend on the engine temperature. Also, temperature influences the vehicle air-conditioner and the cabin heater loads. Particularly, while the engine is cold, the power demand of the cabin heater needs to be provided by the batteries instead of the waste heat of engine coolant. The existing energy management strategies (EMS) of PHEVs focus on the improvement of fuel efficiency based on hot engine characteristics neglecting the effect of temperature on the engine performance and the vehicle power demand. This paper presents a new EMS incorporating an engine thermal management method which derives the global optimal battery charge depletion trajectories. A dynamic programming-based algorithm is developed to enforce the charge depletion boundaries, while optimizing a fuel consumption cost function by controlling the engine power. The optimal control problem formulates the cost function based on two state variables: battery charge and engine internal temperature. Simulation results demonstrate that temperature and the cabin heater/air-conditioner power demand can significantly influence the optimal solution for the EMS, and accordingly fuel efficiency and emissions of PHEVs.

[Copper recovery from artificial bioleaching lixivium of waste printed circuit boards].

PubMed

Cheng, Dan; Zhu, Neng-Wu; Wu, Ping-Xiao; Zou, Ding-Hui; Xing, Yi-Jia

2014-04-01

The key step to realize metal recovery from bioleaching solutions is the recovery of copper from bioleaching lixivium of waste printed circuit boards in high-grade form. The influences of cathode material, current density, initial pH and initial copper ion concentration on the efficiency and energy consumption of copper recovery from artificial bioleaching lixivium under condition of constant current were investigated using an electro-deposition approach. The results showed that the larger specific surface area of the cathode material (carbon felt) led to the higher copper recovery efficiency (the recovery efficiencies of the anode and the cathode chambers were 96.56% and 99.25%, respectively) and the smaller the total and unit mass product energy consumption (the total and unit mass product energy consumptions were 0.022 kW x h and 15.71 kW x h x kg(-1), respectively). The copper recovery efficiency and energy consumption increased with the increase of current density. When the current density was 155.56 mA x cm(-2), the highest copper recovery efficiencies in the anode and cathode chambers reached 98.51% and 99.37%, respectively. Accordingly, the highest total and unit mass product energy consumptions were 0.037 kW x h and 24.34 kW x h x kg(-1), respectively. The copper recovery efficiency was also significantly affected by the initial copper ion concentration. The increase of the initial copper ion concentration would lead to faster decrease of copper ion concentration, higher total energy consumption, and lower unit mass product consumption. However, the initial pH had no significant effect on the copper recovery efficiency. Under the optimal conditions (carbon felt for cathode materials, current density of 111.11 mA x cm(-2), initial pH of 2.0, and initial copper ion concentration of 10 g x L(-1)), the copper recovery efficiencies of the anode and cathode chambers were 96.75% and 99.35%, and the total and unit mass product energy consumptions were 0.021 kW x h and 14.61 kW x h x kg(-1), respectively. The deposited copper on the cathode material was fascicularly distributed and no oxygen was detected.

Energy disclosure, market behavior, and the building data ecosystem.

PubMed

Kontokosta, Constantine E

2013-08-01

Energy disclosure laws represent one of the most promising public policy tools to accelerate market transformation around building energy efficiency. For this type of information to have an impact on market behavior, it must be collected, analyzed, and disseminated to support the decision-making processes of each end user and influence both the producers and consumers of building performance data. This paper explores the significance of energy disclosure requirements and outlines a framework for utilizing these new sources of transparent, publicly available information. It presents the mechanisms by which information can alter market behavior in the commercial real estate sector and develops a wiring diagram for the flows of information through the building data ecosystem. It concludes with a discussion of the motivations, metrics, and constraints faced by the various stakeholders in the ecosystem and how these factors influence investment decision models. © 2013 New York Academy of Sciences.

Energy level alignment at planar organic heterojunctions: influence of contact doping and molecular orientation.

PubMed

Opitz, Andreas

2017-04-05

Planar organic heterojunctions are widely used in photovoltaic cells, light-emitting diodes, and bilayer field-effect transistors. The energy level alignment in the devices plays an important role in obtaining the aspired gap arrangement. Additionally, the π-orbital overlap between the involved molecules defines e.g. the charge-separation efficiency in solar cells due to charge-transfer effects. To account for both aspects, direct/inverse photoemission spectroscopy and near edge x-ray absorption fine structure spectroscopy were used to determine the energy level landscape and the molecular orientation at prototypical planar organic heterojunctions. The combined experimental approach results in a comprehensive model for the electronic and morphological characteristics of the interface between the two investigated molecular semiconductors. Following an introduction on heterojunctions used in devices and on energy levels of organic materials, the energy level alignment of planar organic heterojunctions will be discussed. The observed energy landscape is always determined by the individual arrangement between the energy levels of the molecules and the work function of the electrode. This might result in contact doping due to Fermi level pinning at the electrode for donor/acceptor heterojunctions, which also improves the solar cell efficiency. This pinning behaviour can be observed across an unpinned interlayer and results in charge accumulation at the donor/acceptor interface, depending on the transport levels of the respective organic semiconductors. Moreover, molecular orientation will affect the energy levels because of the anisotropy in ionisation energy and electron affinity and is influenced by the structural compatibility of the involved molecules at the heterojunction. High structural compatibility leads to π-orbital stacking between different molecules at a heterojunction, which is of additional interest for photovoltaic active interfaces and for ground-state charge-transfer.

Milk production and energy efficiency of Holstein and Jersey-Holstein crossbred dairy cows offered diets containing grass silage.

PubMed

Xue, B; Yan, T; Ferris, C F; Mayne, C S

2011-03-01

Eight Holstein and 8 Jersey-Holstein crossbred dairy cows (all primiparous) were used in a repeated 2 (genotype) × 2 (concentrate level) factorial design study involving a total of 4 periods (each of 6-wk duration), designed to examine the effect of cross-breeding on the efficiency of milk production and energy use. The 4 periods began at 5, 11, 27, and 33 wk of lactation, respectively. Animals were offered a completely mixed diet containing grass silage and concentrates, with the level of concentrate in the diet either 30 or 70% of dry matter (DM). During the final 10 d of each period, ration digestibility and energy use was measured, the latter in indirect open-circuit respiration calorimeters. No significant interaction existed between cow genotype and dietary concentrate level for feed intake, milk production, or any of the energy use parameters measured. Across the 2 genotypes, total DM intake, milk yield, and milk protein and lactose concentrations increased with increasing dietary concentrate level. Thus, cows offered the high-concentrate diet had a higher gross energy (GE) intake, and a higher energy output in feces, urine, milk as heat, and a higher metabolizable energy (ME) intake as a proportion of GE intake and as a proportion of digestible energy intake. Across the 2 levels of concentrates, the Jersey-Holstein cows had a significantly higher total DM intake and body condition score, and produced milk with higher fat, protein, and energy concentrations, compared with those of the Holstein cows. In addition, the Jersey-Holstein cows had a significantly higher GE intake and energy output in urine, methane, and milk. However, crossbreeding had no significant effect on energy digestibility or metabolizability, energy partitioning between milk and body tissue, or the efficiency of ME use for lactation. Relating ME intake to milk energy output and heat production indicated that crossbreeding did not influence ME requirement for maintenance or energy efficiencies. The energy metabolism data were also used to compare energy efficiencies between "early" (data pooled for the first 2 periods) and "late" (data pooled for the second 2 periods) stages of lactation. Stage of lactation had no effect on energy digestibility or metabolizability, whereas increasing stage of lactation increased the rate of energy partitioning into body tissue and reduced the rate of energy partitioning into milk, irrespective of cow genotype. In conclusion, crossbreeding of Holstein dams with Jersey sires had no adverse effects on the overall production efficiency of Holstein dairy cows in terms of milk production, efficiency of ME use for lactation, and energy partitioning between milk and body tissue. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Residual energy level based clustering routing protocol for wireless sensor networks

NASA Astrophysics Data System (ADS)

Yuan, Xu; Zhong, Fangming; Chen, Zhikui; Yang, Deli

2015-12-01

The wireless sensor networks, which nodes prone to premature death, with unbalanced energy consumption and a short life time, influenced the promotion and application of this technology in internet of things in agriculture. This paper proposes a clustering routing protocol based on the residual energy level (RELCP). RELCP includes three stages: the selection of cluster head, establishment of cluster and data transmission. RELCP considers the remaining energy level and distance to base station, while election of cluster head nodes and data transmitting. Simulation results demonstrate that the protocol can efficiently balance the energy dissipation of all nodes, and prolong the network lifetime.

Gold-silver@TiO2 nanocomposite-modified plasmonic photoanodes for higher efficiency dye-sensitized solar cells.

PubMed

Lim, Su Pei; Lim, Yee Seng; Pandikumar, Alagarsamy; Lim, Hong Ngee; Ng, Yun Hau; Ramaraj, Ramasamy; Bien, Daniel Chia Sheng; Abou-Zied, Osama K; Huang, Nay Ming

2017-01-04

In the present investigation, gold-silver@titania (Au-Ag@TiO 2 ) plasmonic nanocomposite materials with different Au and Ag compositions were prepared using a simple one-step chemical reduction method and used as photoanodes in high-efficiency dye-sensitized solar cells (DSSCs). The Au-Ag incorporated TiO 2 photoanode demonstrated an enhanced solar-to-electrical energy conversion efficiency of 7.33%, which is ∼230% higher than the unmodified TiO 2 photoanode (2.22%) under full sunlight illumination (100 mW cm -2 , AM 1.5G). This superior solar energy conversion efficiency was mainly due to the synergistic effect between the Au and Ag, and their surface plasmon resonance effect, which improved the optical absorption and interfacial charge transfer by minimizing the charge recombination process. The influence of the Au-Ag composition on the overall energy conversion efficiency was also explored, and the optimized composition with TiO 2 was found to be Au 75 -Ag 25 . This was reflected in the femtosecond transient absorption dynamics in which the electron-phonon interaction in the Au nanoparticles was measured to be 6.14 ps in TiO 2 /Au 75 :Ag 25 , compared to 2.38 ps for free Au and 4.02 ps for TiO 2 /Au 100 :Ag 0 . The slower dynamics indicates a more efficient electron-hole separation in TiO 2 /Au 75 :Ag 25 that is attributed to the formation of a Schottky barrier at the interface between TiO 2 and the noble metal(s) that acts as an electron sink. The significant boost in the solar energy conversion efficiency with the Au-Ag@TiO 2 plasmonic nanocomposite showed its potential as a photoanode for high-efficiency DSSCs.

Defect Chemistry of Oxides for Energy Applications.

PubMed

Schweke, Danielle; Mordehovitz, Yuval; Halabi, Mahdi; Shelly, Lee; Hayun, Shmuel

2018-05-31

Oxides are widely used for energy applications, as solid electrolytes in various solid oxide fuel cell devices or as catalysts (often associated with noble metal particles) for numerous reactions involving oxidation or reduction. Defects are the major factors governing the efficiency of a given oxide for the above applications. In this paper, the common defects in oxide systems and external factors influencing the defect concentration and distribution are presented, with special emphasis on ceria (CeO 2 ) based materials. It is shown that the behavior of a variety of oxide systems with respect to properties relevant for energy applications (conductivity and catalytic activity) can be rationalized by general considerations about the type and concentration of defects in the specific system. A new method based on transmission electron microscopy (TEM), recently reported by the authors for mapping space charge defects and measuring space charge potentials, is shown to be of potential importance for understanding conductivity mechanisms in oxides. The influence of defects on gas-surface reactions is exemplified on the interaction of CO 2 and H 2 O with ceria, by correlating between the defect distribution in the material and its adsorption capacity or splitting efficiency. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental investigation of a small solar chimney in the south of Algeria

NASA Astrophysics Data System (ADS)

Hadj, Achouri El; Noureddine, Settou; Mabrouk, Drid Momamed; Belkhir, Negrou; Soumia, Rahmouni

2018-05-01

The solar chimney power plant (SCPP) is an economical device for the production of solar electricity. Among the parameters influencing the efficiency of the solar chimney are the dimensions, namely: Height and diameter of the chimney and diameter and height of the collector. In order to give our contribution we have established a prototype of a solar chimney which allows us to take a real vision on the influence of the geometrical parameters on the air flow under the collector and next the production efficiency of the solar chimney in the south of Algeria. In this study, we take different values of the height and diameter of the tower and of the height of the collector entrance. The results obtained show the remarkable influence of the geometrical parameters on the flow velocity afterwards on the energy produced.

How can we tackle energy efficiency in IoT based smart buildings?

PubMed

Moreno, M Victoria; Úbeda, Benito; Skarmeta, Antonio F; Zamora, Miguel A

2014-05-30

Nowadays, buildings are increasingly expected to meet higher and more complex performance requirements. Among these requirements, energy efficiency is recognized as an international goal to promote energy sustainability of the planet. Different approaches have been adopted to address this goal, the most recent relating consumption patterns with human occupancy. In this work, we analyze what are the main parameters that should be considered to be included in any building energy management. The goal of this analysis is to help designers to select the most relevant parameters to control the energy consumption of buildings according to their context, selecting them as input data of the management system. Following this approach, we select three reference smart buildings with different contexts, and where our automation platform for energy monitoring is deployed. We carry out some experiments in these buildings to demonstrate the influence of the parameters identified as relevant in the energy consumption of the buildings. Then, in two of these buildings are applied different control strategies to save electrical energy. We describe the experiments performed and analyze the results. The first stages of this evaluation have already resulted in energy savings of about 23% in a real scenario.

How can We Tackle Energy Efficiency in IoT Based Smart Buildings?

PubMed Central

Moreno, M. Victoria; Úbeda, Benito; Skarmeta, Antonio F.; Zamora, Miguel A.

2014-01-01

Nowadays, buildings are increasingly expected to meet higher and more complex performance requirements. Among these requirements, energy efficiency is recognized as an international goal to promote energy sustainability of the planet. Different approaches have been adopted to address this goal, the most recent relating consumption patterns with human occupancy. In this work, we analyze what are the main parameters that should be considered to be included in any building energy management. The goal of this analysis is to help designers to select the most relevant parameters to control the energy consumption of buildings according to their context, selecting them as input data of the management system. Following this approach, we select three reference smart buildings with different contexts, and where our automation platform for energy monitoring is deployed. We carry out some experiments in these buildings to demonstrate the influence of the parameters identified as relevant in the energy consumption of the buildings. Then, in two of these buildings are applied different control strategies to save electrical energy. We describe the experiments performed and analyze the results. The first stages of this evaluation have already resulted in energy savings of about 23% in a real scenario. PMID:24887040

Correlation of Hydrogen-Atom Abstraction Reaction Efficiencies for Aryl Radicals with their Vertical Electron Affinities and the Vertical Ionization Energies of the Hydrogen Atom Donors

PubMed Central

Jing, Linhong; Nash, John J.

2009-01-01

The factors that control the reactivities of aryl radicals toward hydrogen-atom donors were studied by using a dual-cell Fourier-transform ion cyclotron resonance mass spectrometer (FT – ICR). Hydrogen-atom abstraction reaction efficiencies for two substrates, cyclohexane and isopropanol, were measured for twenty-three structurally different, positively-charged aryl radicals, which included dehydrobenzenes, dehydronaphthalenes, dehydropyridines, and dehydro(iso)quinolines. A logarithmic correlation was found between the hydrogen-atom abstraction reaction efficiencies and the (calculated) vertical electron affinities (EA) of the aryl radicals. Transition state energies calculated for three of the aryl radicals with isopropanol were found to correlate linearly with their (calculated) EAs. No correlation was found between the hydrogen-atom abstraction reaction efficiencies and the (calculated) enthalpy changes for the reactions. Measurement of the reaction efficiencies for the reactions of several different hydrogen-atom donors with a few selected aryl radicals revealed a logarithmic correlation between the hydrogen-atom abstraction reaction efficiencies and the vertical ionization energies (IE) of the hydrogen-atom donors, but not the lowest homolytic X – H (X = heavy atom) bond dissociation energies of the hydrogen-atom donors. Examination of the hydrogen-atom abstraction reactions of twenty-nine different aryl radicals and eighteen different hydrogen-atom donors showed that the reaction efficiency increases (logarithmically) as the difference between the IE of the hydrogen-atom donor and the EA of the aryl radical decreases. This dependence is likely to result from the increasing polarization, and concomitant stabilization, of the transition state as the energy difference between the neutral and ionic reactants decreases. Thus, the hydrogen-atom abstraction reaction efficiency for an aryl radical can be “tuned” by structural changes that influence either the vertical EA of the aryl radical or the vertical IE of the hydrogen atom donor. PMID:19061320

Energy Systems Integration Facility | NREL

Science.gov Websites

influence how electric power systems operate far into the future. LEARN MORE Sharing Knowledge Recent 2017 Journal Article Wind and Solar Resource Data Sets Technical Report Innovation Incubator , Liquid Submerged Server for High-Efficiency Data Centers News and Announcements News More News News

Energy efficiency : potential fuel savings generated by a national speed limit would be influenced by many other factors.

DOT National Transportation Integrated Search

2008-11-07

"Congress expressed interest in obtaining information on using a national speed limit to reduce fuel consumption. In response to the request, we reviewed existing literature and consulted knowledgeable stakeholders on the following: (1) What is the r...

A theoretical investigation of the influence of gold nanosphere size on the decay and energy transfer rates and efficiencies of quantum emitters.

PubMed

Marocico, Cristian A; Zhang, Xia; Bradley, A Louise

2016-01-14

We present in this contribution a comprehensive investigation of the effect of the size of gold nanospheres on the decay and energy transfer rates of quantum systems placed close to these nanospheres. These phenomena have been investigated before, theoretically and experimentally, but no comprehensive study of the influence of the nanoparticle size on important dependences of the decay and energy transfer rates, such as the dependence on the donor-acceptor spectral overlap and the relative positions of the donor, acceptor, and nanoparticle, exists. As such, different accounts of the energy transfer mechanism have been presented in the literature. We perform an investigation of the energy transfer mechanisms between emitters and gold nanospheres and between donor-acceptor pairs in the presence of the gold nanospheres using a Green's tensor formalism, experimentally verified in our lab. We find that the energy transfer rate to small nanospheres is greatly enhanced, leading to a strong quenching of the emission of the emitter. When the nanosphere size is increased, it acts as an antenna, increasing the emission of the emitter. We also investigate the emission wavelength and intrinsic quantum yield dependence of the energy transfer to the nanosphere. As evidenced from the literature, the energy transfer process between the quantum system and the nanosphere can have a complicated distance dependence, with a r(-6) regime, characteristic of the Förster energy transfer mechanism, but also exhibiting other distance dependences. In the case of a donor-acceptor pair of quantum systems in the presence of a gold nanosphere, when the donor couples strongly to the nanosphere, acting as an enhanced dipole; the donor-acceptor energy transfer rate then follows a Förster trend, with an increased Förster radius. The coupling of the acceptor to the nanosphere has a different distance dependence. The angular dependence of the energy transfer efficiency between donor and acceptor exhibits a strong focusing effect and the same enhanced donor-dipole character in different angular arrangements. The spectral overlap of the donor emission and acceptor absorption spectra shows that the energy transfer follows the near-field scattering efficiency, with a red-shift from the localized surface plasmon peak for small sphere sizes.

Influence of quantum dot's quantum yield to chemiluminescent resonance energy transfer.

PubMed

Wang, Hai-Qiao; Li, Yong-Qiang; Wang, Jian-Hao; Xu, Qiao; Li, Xiu-Qing; Zhao, Yuan-Di

2008-03-03

The resonance energy transfer between chemiluminescence donor (luminol-H2O2 system) and quantum dots (QDs, emission at 593 nm) acceptors (CRET) was investigated. The resonance energy transfer efficiencies were compared while the oil soluble QDs, water soluble QDs (modified with thioglycolate) and QD-HRP conjugates were used as acceptor. The fluorescence of QD can be observed in the three cases, indicating that the CRET occurs while QD acceptor in different status was used. The highest CRET efficiency (10.7%) was obtained in the case of oil soluble QDs, and the lowest CRET efficiency (2.7%) was observed in the QD-HRP conjugates case. This result is coincident with the quantum yields of the acceptors (18.3% and 0.4%). The same result was observed in another similar set of experiment, in which the amphiphilic polymer modified QDs (emission at 675 nm) were used. It suggests that the quantum yield of the QD in different status is the crucial factor to the CRET efficiency. Furthermore, the multiplexed CRET between luminol donor and three different sizes QD acceptors was observed simultaneously. This work will offer useful support for improving the CRET studies based on quantum dots.

Study on key technologies of optimization of big data for thermal power plant performance

NASA Astrophysics Data System (ADS)

Mao, Mingyang; Xiao, Hong

2018-06-01

Thermal power generation accounts for 70% of China's power generation, the pollutants accounted for 40% of the same kind of emissions, thermal power efficiency optimization needs to monitor and understand the whole process of coal combustion and pollutant migration, power system performance data show explosive growth trend, The purpose is to study the integration of numerical simulation of big data technology, the development of thermal power plant efficiency data optimization platform and nitrogen oxide emission reduction system for the thermal power plant to improve efficiency, energy saving and emission reduction to provide reliable technical support. The method is big data technology represented by "multi-source heterogeneous data integration", "large data distributed storage" and "high-performance real-time and off-line computing", can greatly enhance the energy consumption capacity of thermal power plants and the level of intelligent decision-making, and then use the data mining algorithm to establish the boiler combustion mathematical model, mining power plant boiler efficiency data, combined with numerical simulation technology to find the boiler combustion and pollutant generation rules and combustion parameters of boiler combustion and pollutant generation Influence. The result is to optimize the boiler combustion parameters, which can achieve energy saving.

The impact of state energy programs and other contextual factors on U.S. buildings energy consumption

NASA Astrophysics Data System (ADS)

Ofori-Boadu, Andrea N. Y. A.

High energy consumption in the United States has been influenced by populations, climates, income and other contextual factors. In the past decades, U.S. energy policies have pursued energy efficiency as a national strategy for reducing U.S. environmental degradation and dependence on foreign oils. The quest for improved energy efficiency has led to the development of energy efficient technologies and programs. The implementation of energy programs in the complex U.S. socio-technical environment is believed to promote the diffusion of energy efficiency technologies. However, opponents doubt the fact that these programs have the capacity to significantly reduce U.S. energy consumption. In order to contribute to the ongoing discussion, this quantitative study investigated the relationships existing among electricity consumption/ intensity, energy programs and contextual factors in the U.S. buildings sector. Specifically, this study sought to identify the significant predictors of electricity consumption and intensity, as well as estimate the overall impact of selected energy programs on electricity consumption and intensity. Using state-level secondary data for 51 U.S. states from 2006 to 2009, seven random effects panel data regression models confirmed the existence of significant relationships among some energy programs, contextual factors, and electricity consumption/intensity. The most significant predictors of improved electricity efficiency included the price of electricity, public benefits funds program, building energy codes program, financial and informational incentives program and the Leadership in Energy and Environmental Design (LEED) program. Consistently, the Southern region of the U.S. was associated with high electricity consumption and intensity; while the U.S. commercial sector was the greater benefactor from energy programs. On the average, energy programs were responsible for approximately 7% of the variation observed in electricity consumption and intensity, over and above the variation associated with the contextual factors. This study also had implications in program implementation theory, and revealed that resource availability, stringency and adherence had significant impacts on program outcomes. Using seven classification tables, this study categorized and matched the predictors of electricity consumption and intensity with the specific energy sectors in which they demonstrated significance. Project developers, energy advocates, policy makers, program administrators, building occupants and other stakeholders could use study findings in conjunction with other empirical findings, to make informed decisions regarding the adoption, continuation or discontinuation of energy programs, while taking contextual factors into consideration. The adoption and efficient implementation of the most significant programs could reduce U.S. electricity consumption, and in the long term, probably reduce U.S. energy waste, environmental degradation, energy imports, energy prices, and demands for expanding energy generation and distribution infrastructure.

Efficiency of food utilization by pregnant and lactating sows. 2. The influence of isocaloric diets with different protein levels on pregnancy and lactation.

PubMed

Burlacu, G; Iliescu, M; Cărămidă, P

1986-09-01

The efficiency of utilization of feed energy as digestible, metabolizable and net energy is similar in pregnant and lactating sows irrespective of the stage of these physiological conditions. This efficiency with the value of about 71% resembles the one found in the growing and fattening pigs, which enables us to use, for this category of animals, the same system offered evaluation and of the energy requirements based on fat nutritive units. The maintenance energy requirement expressed in ME varies from 467 kJ/kg 0.75 in pregnant sows to 512 kJ/kg 0.75 in lactating sows, for the suckling piglets having intermediary value of 498 kJ/kg 0.75. The efficiency of utilization of diets protein for maintenance and for synthesis is also similar for these categories of pigs, varying from 71% in lactating sows to 75-76% in pregnant sows. In suckling piglets we had recorded an efficiency of DCP utilization which varies parabolically with size of the ingesta and therefore with that of weight gain. The DCP maintenance requirement expressed in g N dig./kg 0.75 varies within narrow limits between 0.345 g N in suckling piglets 0.380 g N in pregnant sows; In lactating sows we have detected an intermediary value of 0.355 g N. Based on these experimental data and also using recent experimental results obtained by Schiemann and Beyer (1984) regarding the energy and N content of the foetuses, of the organs of reproductions and of milk, we could calculate the energy and protein requirements. These requirements when compared with the values used in our country show us higher values of energy in pregnant and lactating sows and lower values of protein for the same categories, including the piglets, where we have also found lower values for the energy too.

Divergent genetic selection for residual feed intake impacts mitochondria reactive oxygen species production in pigs.

PubMed

Grubbs, J K; Fritchen, A N; Huff-Lonergan, E; Dekkers, J C M; Gabler, N K; Lonergan, S M

2013-05-01

The objective of this study was to determine the extent to which genetic selection for residual feed intake (RFI) impacts electron leakage and reactive oxygen species (ROS) production in mitochondria from muscle and liver tissue. Understanding how genetic selection for RFI impacts animal physiology and growth efficiency is of the utmost importance as the world population increases. Production efficiency is tied directly to energy use. Mitochondria were used in this study because they produce 90% of the ATP in the body and use a large majority of dietary energy. Mitochondria were isolated from both muscle and liver tissue from pigs genetically selected for RFI (n = 8 per RFI line; 34 ± 4 kg). A 2,7-dichlorofluorscein diacetate assay was used to detect differences in hydrogen peroxide production between the more efficient low RFI line and the less efficient high RFI line. Our hypothesis was that greater efficiency would be linked to less ROS production from the mitochondria. There was less ROS production in mitochondria from the white portion of the semitendinosus in the low RFI line compared with the high RFI line, when both NADH and Flavin Adenine Dinucleotide (FADH2) energy substrates were used (glutamate and succinate, respectively). Additionally, mitochondria from the red portion of the semitendinosus in the low RFI line had less ROS production when succinate was used as an energy substrate (P < 0.05). A positive correlation was observed between RFI and ROS in mitochondria from the LM. These data indicate genetic selection for RFI may influence mitochondrial ROS production and efficiency of pork production.

Three Essays on National Oil Company Efficiency, Energy Demand and Transportation

NASA Astrophysics Data System (ADS)

Eller, Stacy L.

This dissertation is composed of three separate essays in the field of energy economics. In the first paper, both data envelopment analysis and stochastic production frontier estimation are employed to provide empirical evidence on the revenue efficiency of national oil companies (NOCs) and private international oil companies (IOCs). Using a panel of 80 oil producing firms, the analysis suggests that NOCs are generally less efficient at generating revenue from a given resource base than IOCs, with some exceptions. Due to differing firm objectives, however, structural and institutional features may help explain much of the inefficiency. The second paper analyzes the relationship between economic development and the demand for energy. Energy consumption is modeled using panel data from 1990 to 2004 for 50 countries spanning all levels of development. We find the relationship between energy consumption and economic development corresponds to the structure of aggregate output and the nature of derived demand for electricity and direct-use fuels in each sector. Notably, the evidence of non-constant income elasticity of demand is much greater for electricity demand than for direct-use fuel consumption. In addition, we show that during periods of rapid economic development, one in which the short-term growth rate exceeds the long-run average, an increase in aggregate output is met by less energy-efficient capital. This is a result of capital being fixed in the short-term. As additional, more efficient capital stock is added to the production process, the short-term increase in energy intensity will diminish. In the third essay, we develop a system of equations to estimate a model of motor vehicle fuel consumption, vehicle miles traveled and implied fuel efficiency for the 67 counties of the State of Florida from 2001 to 2008. This procedure allows us to decompose the factors of fuel demand into elasticities of vehicle driving demand and fuel efficiency. Particular attention is paid to the influence of the price of fuel, the sale of goods and services, vehicle ownership and population density on each component of our model.

Impact of Feed Efficiency and Diet on Adaptive Variations in the Bacterial Community in the Rumen Fluid of Cattle

PubMed Central

Hernandez-Sanabria, Emma; Goonewardene, Laksiri A.; Wang, Zhiquan; Durunna, Obioha N.; Moore, Stephen S.

2012-01-01

Limited knowledge of the structure and activities of the ruminal bacterial community prevents the understanding of the effect of population dynamics on functional bacterial groups and on host productivity. This study aimed to identify particular bacteria associated with host feed efficiency in steers with differing diets and residual feed intake (RFI) using culture-independent methods: PCR-denaturing gradient gel electrophoresis (DGGE) and quantitative real-time PCR analysis. PCR-DGGE profiles were generated from the ruminal fluid of 55 steers fed a low-energy-density diet and then switched to a high-energy-density diet. Bacterial profile comparisons by multivariate statistical analysis showed a trend only for RFI-related clusters on the high-energy diet. When steers (n = 19) belonging to the same RFI group under both diets were used to identify specific bacterial phylotypes related to feed efficiency traits, correlations were detected between dry matter intake, average daily gain, and copy numbers of the 16S rRNA gene of Succinivibrio sp. in low-RFI (efficient) steers, whereas correlations between Robinsoniella sp. and RFI (P < 0.05) were observed for high-RFI (inefficient) animals. Eubacterium sp. differed significantly (P < 0.05) between RFI groups that were only on the high-energy diet. Our work provides a comprehensive framework to understand how particular bacterial phylotypes contribute to differences in feed efficiency and ultimately influence host productivity, which may either depend on or be independent from diet factors. PMID:22156428

Millimeter Wave Radar for Atmospheric Turbulence Characterization and Wind Profiling for Improved Naval Operations

DTIC Science & Technology

2016-12-29

airflows surrounding ships can be used to determine operational envelopes, more efficiently space incoming aircraft, and can be used in conjunction with...aircraft, and can be used in conjunction with simulations to inform and influence ship design. Another application is for high-energy laser propagation

Numerical Study of a 10 K Two Stage Pulse Tube Cryocooler with Precooling Inside the Pulse Tube

NASA Astrophysics Data System (ADS)

Xiaomin, Pang; Xiaotao, Wang; Wei, Dai; Jianyin, Hu; Ercang, Luo

2017-02-01

High efficiency cryocoolers working below 10 K have many applications such as cryo-pump, superconductor cooling and cryogenic electronics. This paper presents a thermally coupled two-stage pulse tube cryocooler system and its numeric analysis. The simulation results indicate that temperature distribution in the pulse tube has a significant impact on the system performance. So a precooling heat exchanger is put inside the second stage pulse tube for a deep investigation on its influence on the system performance. The influences of operating parameters such as precooling temperature, location of the precooling heat exchanger are discussed. Comparison of energy losses apparently show the advantages of the configuration which leads to an improvement on the efficiency. Finally, the cryocooler is predicted to be able to reach a relative Carnot efficiency of 10.7% at 10 K temperature.

Preparation of reflective CsI photocathodes with reproducible high quantum efficiency

NASA Astrophysics Data System (ADS)

Maier-Komor, P.; Bauer, B. B.; Friese, J.; Gernhäuser, R.; Kienle, P.; Körner, H. J.; Montermann, G.; Zeitelhack, K.

1995-02-01

CsI as a solid UV-photocathode material has many promising applications in fast gaseous photon detectors. They are proposed in large area Ring Imaging CHerenkov (RICH) devices in forthcoming experiments at various high-energy particle accelerators. A high photon-to-electron conversion efficiency is a basic requirement for the successful operation of these devices. High reproducible quantum efficiencies could be achieved with CsI layers prepared by electron beam evaporation from a water-cooled copper crucible. CsI films were deposited in the thickness range of 30 to 500 μg/cm 2. Absorption coefficients and quantum efficiencies were measured in the wavelength region of 150 nm to 250 nm. The influence of various evaporation parameters on the quantum efficiency were investigated.

SU-F-T-376: The Efficiency of Calculating Photonuclear Reaction On High-Energy Photon Therapy by Monte Carlo Method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirayama, S; Fujibuchi, T

Purpose: Secondary-neutrons having harmful influences to a human body are generated by photonuclear reaction on high-energy photon therapy. Their characteristics are not known in detail since the calculation to evaluate them takes very long time. PHITS(Particle and Heavy Ion Transport code System) Monte Carlo code since versions 2.80 has the new parameter “pnimul” raising the probability of occurring photonuclear reaction forcibly to make the efficiency of calculation. We investigated the optimum value of “pnimul” on high-energy photon therapy. Methods: The geometry of accelerator head based on the specification of a Varian Clinac 21EX was used for PHITS ver. 2.80. Themore » phantom (30 cm * 30 cm * 30 cm) filled the composition defined by ICRU(International Commission on Radiation Units) was placed at source-surface distance 100 cm. We calculated the neutron energy spectra in the surface of ICRU phantom with “pnimal” setting 1, 10, 100, 1000, 10000 and compared the total calculation time and the behavior of photon using PDD(Percentage Depth Dose) and OCR(Off-Center Ratio). Next, the cutoff energy of photon, electron and positron were investigated for the calculation efficiency with 4, 5, 6 and 7 MeV. Results: The calculation total time until the errors of neutron fluence become within 1% decreased as increasing “pnimul”. PDD and OCR showed no differences by the parameter. The calculation time setting the cutoff energy like 4, 5, 6 and 7 MeV decreased as increasing the cutoff energy. However, the errors of photon become within 1% did not decrease by the cutoff energy. Conclusion: The optimum values of “pnimul” and the cutoff energy were investigated on high-energy photon therapy. It is suggest that using the optimum “pnimul” makes the calculation efficiency. The study of the cutoff energy need more investigation.« less

Mechanical excitation of rodlike particles by a vibrating plate.

PubMed

Trittel, Torsten; Harth, Kirsten; Stannarius, Ralf

2017-06-01

The experimental realization and investigation of granular gases usually require an initial or permanent excitation of ensembles of particles, either mechanically or electromagnetically. One typical method is the energy supply by a vibrating plate or container wall. We study the efficiency of such an excitation of cylindrical particles by a sinusoidally oscillating wall and characterize the distribution of kinetic energies of excited particles over their degrees of freedom. The influences of excitation frequency and amplitude are analyzed.

A logistic regression approach to model the willingness of consumers to adopt renewable energy sources

NASA Astrophysics Data System (ADS)

Ulkhaq, M. M.; Widodo, A. K.; Yulianto, M. F. A.; Widhiyaningrum; Mustikasari, A.; Akshinta, P. Y.

2018-03-01

The implementation of renewable energy in this globalization era is inevitable since the non-renewable energy leads to climate change and global warming; hence, it does harm the environment and human life. However, in the developing countries, such as Indonesia, the implementation of the renewable energy sources does face technical and social problems. For the latter, renewable energy sources implementation is only effective if the public is aware of its benefits. This research tried to identify the determinants that influence consumers’ intention in adopting renewable energy sources. In addition, this research also tried to predict the consumers who are willing to apply the renewable energy sources in their houses using a logistic regression approach. A case study was conducted in Semarang, Indonesia. The result showed that only eight variables (from fifteen) that are significant statistically, i.e., educational background, employment status, income per month, average electricity cost per month, certainty about the efficiency of renewable energy project, relatives’ influence to adopt the renewable energy sources, energy tax deduction, and the condition of the price of the non-renewable energy sources. The finding of this study could be used as a basis for the government to set up a policy towards an implementation of the renewable energy sources.

Atomic Layer-Deposited Molybdenum Oxide/Carbon Nanotube Hybrid Electrodes: The Influence of Crystal Structure on Lithium-Ion Capacitor Performance.

PubMed

Fleischmann, Simon; Zeiger, Marco; Quade, Antje; Kruth, Angela; Presser, Volker

2018-06-06

Merging of supercapacitors and batteries promises the creation of electrochemical energy storage devices that combine high specific energy, power, and cycling stability. For that purpose, lithium-ion capacitors (LICs) that store energy by lithiation reactions at the negative electrode and double-layer formation at the positive electrode are currently investigated. In this study, we explore the suitability of molybdenum oxide as a negative electrode material in LICs for the first time. Molybdenum oxide-carbon nanotube hybrid materials were synthesized via atomic layer deposition, and different crystal structures and morphologies were obtained by post-deposition annealing. These model materials are first structurally characterized and electrochemically evaluated in half-cells. Benchmarking in LIC full-cells revealed the influences of crystal structure, half-cell capacity, and rate handling on the actual device level performance metrics. The energy efficiency, specific energy, and power are mainly influenced by the overpotential and kinetics of the lithiation reaction during charging. Optimized LIC cells show a maximum specific energy of about 70 W·h·kg -1 and a high specific power of 4 kW·kg -1 at 34 W·h·kg -1 . The longevity of the LIC cells is drastically increased without significantly reducing the energy by preventing a deep cell discharge, hindering the negative electrode from crossing its anodic potential limit.

Nonlinear pyroelectric energy harvesting from relaxor single crystals.

PubMed

Khodayari, Akram; Pruvost, Sebastien; Sebald, Gael; Guyomar, Daniel; Mohammadi, Saber

2009-04-01

Energy harvesting from temperature variations in a Pb(Zn(1/3)Nb(2/3))(0.955)Ti(0.045)O(3) single crystal was studied and evaluated using the Ericsson thermodynamic cycle. The efficiency of this cycle related to Carnot cycle is 100 times higher than direct pyroelectric energy harvesting, and it can be as high as 5.5% for a 10 degrees C temperature variation and 2 kV/mm electric field. The amount of harvested energy for a 60 degrees C temperature variation and 2 kV/mm electric field is 242.7 mJ x cm(-3). The influence of ferroelectric phase transitions on the energy harvesting performance is discussed and illustrated with experimental results.

Influence of other rare earth ions on the optical refrigeration efficiency in Yb:YLF crystals.

PubMed

Di Lieto, Alberto; Sottile, Alberto; Volpi, Azzurra; Zhang, Zhonghan; Seletskiy, Denis V; Tonelli, Mauro

2014-11-17

We investigated the effect of rare earth impurities on the cooling efficiency of Yb³⁺:LiYF₄ (Yb:YLF). The refrigeration performance of two single crystals, doped with 5%-at. Yb and with identical history but with different amount of contaminations, have been compared by measuring the cooling efficiency curves. Spectroscopic and elemental analyses of the samples have been carried out to identify the contaminants, to quantify their concentrations and to understand their effect on the cooling efficiencies. A model of energy transfer processes between Yb and other rare earth ions is suggested, identifying Erbium and Holmium as elements that produce a detrimental effect on the cooling performance.

Rational design of efficient electrode–electrolyte interfaces for solid-state energy storage using ion soft landing

DOE PAGES

Prabhakaran, Venkateshkumar; Mehdi, B. Layla; Ditto, Jeffrey J.; ...

2016-04-21

Here, the rational design of improved electrode-electrolyte interfaces (EEI) for energy storage is critically dependent on a molecular-level understanding of ionic interactions and nanoscale phenomena. The presence of non-redox active species at EEI has been shown to strongly influence Faradaic efficiency and long-term operational stability during energy storage processes. Herein, we achieve substantially higher performance and long-term stability of EEI prepared with highly-dispersed discrete redox-active cluster anions (50 ng of pure ~0.7 nm size molybdenum polyoxometalate anions (POM) anions on 25 mg (≈ 0.2 wt%) carbon nanotube (CNT) electrodes) by complete elimination of strongly coordinating non-redox species through ion soft-landingmore » (SL). For the first time, electron microscopy provides atomically-resolved images of individual POM species directly on complex technologically relevant CNT electrodes. In this context, SL is established as a versatile approach for the controlled design of novel surfaces for both fundamental and applied research in energy storage.« less

Research on natural lighting in reading spaces of university libraries in Jinan under the perspective of energy-efficiency

NASA Astrophysics Data System (ADS)

Yang, Zengzhang

2017-11-01

The natural lighting design in the reading spaces of university libraries not only influences physical and mental health of readers but also concerns the energy consumption of the libraries. The scientific and rational design of natural lighting is the key to the design of energy saving for physical environment of the reading space. The paper elaborates the present situation and existed problems of natural lighting in reading spaces of university libraries across Jinan region based on characteristics of light climate of Jinan region and concrete utilization of reading spaces in university libraries, and combining field measurement, survey, research and data analysis of reading spaces in Shandong Women’s University’s library. The paper, under the perspective of energy-efficiency, puts forward proposals to improve natural lighting in the reading spaces of university libraries from five aspects, such as adjustment of interior layout, optimization of outer windows design, employment of the reflector panel, design lighting windows on inner walls and utilization of adjustable sun shading facilities.

Influence of sward maturity and pre-conditioning temperature on the energy production from grass silage through the integrated generation of solid fuel and biogas from biomass (IFBB): 2. Properties of energy carriers and energy yield.

PubMed

Richter, F; Fricke, T; Wachendorf, M

2011-04-01

In order to determine influencing parameters on energy production of the IFBB process, herbage from a lowland hay meadow (Arrhenaterion) was sampled and ensiled at eight dates between 27 April and 21 June 2007. The silage from each date was processed in six IFBB treatments with and without hydrothermal conditioning at different temperatures. Methane yields and higher heating values were determined and an energy balance was calculated with whole-crop digestion (WCD) of the silage as reference system. Maximum net energy yields were 10.2 MWh ha(-1) for the IFBB treatment without hydrothermal conditioning and 9.0 MWh ha(-1) for the treatment with hydrothermal conditioning at 50 °C. WCD achieved a maximum net energy yield of 3.7 MWh ha(-1). Energy conversion efficiency ranged from 0.24 to 0.54 and was predicted with high accuracy by temperature of hydrothermal conditioning as well as concentration of neutral detergent fibre and dry matter in the silage (R(2)=0.90). Copyright © 2011 Elsevier Ltd. All rights reserved.

Cross Layer Design for Optimizing Transmission Reliability, Energy Efficiency, and Lifetime in Body Sensor Networks.

PubMed

Chen, Xi; Xu, Yixuan; Liu, Anfeng

2017-04-19

High transmission reliability, energy efficiency, and long lifetime are pivotal issues for wireless body area networks (WBANs. However, these performance metrics are not independent of each other, making it hard to obtain overall improvements through optimizing one single aspect. Therefore, a Cross Layer Design Optimal (CLDO) scheme is proposed to simultaneously optimize transmission reliability, energy efficiency, and lifetime of WBANs from several layers. Firstly, due to the fact that the transmission power of nodes directly influences the reliability of links, the optimized transmission power of different nodes is deduced, which is able to maximize energy efficiency in theory under the premise that requirements on delay and jitter are fulfilled. Secondly, a relay decision algorithm is proposed to choose optimized relay nodes. Using this algorithm, nodes will choose relay nodes that ensure a balance of network energy consumption, provided that all nodes transmit with optimized transmission power and the same packet size. Thirdly, the energy consumption of nodes is still unbalanced even with optimized transmission power because of their different locations in the topology of the network. In addition, packet size also has an impact on final performance metrics. Therefore, a synthesized cross layer method for optimization is proposed. With this method, the transmission power of nodes with more residual energy will be enhanced while suitable packet size is determined for different links in the network, leading to further improvements in the WBAN system. Both our comprehensive theoretical analysis and experimental results indicate that the performance of our proposed scheme is better than reported in previous studies. Relative to the relay selection and power control game (RSPCG) scheme, the CLDO scheme can enhance transmission reliability by more than 44.6% and prolong the lifetime by as much as 33.2%.

Cross Layer Design for Optimizing Transmission Reliability, Energy Efficiency, and Lifetime in Body Sensor Networks

PubMed Central

Chen, Xi; Xu, Yixuan; Liu, Anfeng

2017-01-01

High transmission reliability, energy efficiency, and long lifetime are pivotal issues for wireless body area networks (WBANs). However, these performance metrics are not independent of each other, making it hard to obtain overall improvements through optimizing one single aspect. Therefore, a Cross Layer Design Optimal (CLDO) scheme is proposed to simultaneously optimize transmission reliability, energy efficiency, and lifetime of WBANs from several layers. Firstly, due to the fact that the transmission power of nodes directly influences the reliability of links, the optimized transmission power of different nodes is deduced, which is able to maximize energy efficiency in theory under the premise that requirements on delay and jitter are fulfilled. Secondly, a relay decision algorithm is proposed to choose optimized relay nodes. Using this algorithm, nodes will choose relay nodes that ensure a balance of network energy consumption, provided that all nodes transmit with optimized transmission power and the same packet size. Thirdly, the energy consumption of nodes is still unbalanced even with optimized transmission power because of their different locations in the topology of the network. In addition, packet size also has an impact on final performance metrics. Therefore, a synthesized cross layer method for optimization is proposed. With this method, the transmission power of nodes with more residual energy will be enhanced while suitable packet size is determined for different links in the network, leading to further improvements in the WBAN system. Both our comprehensive theoretical analysis and experimental results indicate that the performance of our proposed scheme is better than reported in previous studies. Relative to the relay selection and power control game (RSPCG) scheme, the CLDO scheme can enhance transmission reliability by more than 44.6% and prolong the lifetime by as much as 33.2%. PMID:28422062

Impact of fouling on the decline of aeration efficiency under different operational conditions at WRRFs.

PubMed

Garrido-Baserba, Manel; Asvapathanagul, Pitiporn; Park, Hee-Deung; Kim, Taek-Seung; Baquero-Rodriguez, G Andres; Olson, Betty H; Rosso, Diego

2018-10-15

Biofilm formation influences the most energy-demanding process in the waste water treatment cycle. Biofilm growth on the surface of wastewater aeration diffusers in water resource recovery facilities (WRRFs) can increase the energy requirements up to 50% in less than 2 years. The impact of biofilms in aeration diffusers was quantified and assessed for first time using molecular tools (i.e., Energy-dispersive X-ray, Ra and RMS and Pyrosequencing) and state-of-the-art techniques (i.e., EPS quantification, Hydrophobicity and DNA quantification). To provide a better understanding and quantitative connections between biological activity and aeration energy efficiency, two replicates of the most common diffusers were installed and tested in two different operational conditions (higher and lower organic loading rate processes) during 15 months. Different scenarios and conditions provided for first time comprehensive understanding of the major factors contributing to diffuser fouling. The array of analysis suggested that higher loading conditions can promote specialized microbial populations to halve aeration efficiency parameters (i.e., αF) in comparison to lower loading conditions. Biofilms adapted to certain operational conditions can trigger changes in diffuser membrane properties (i.e., biological enhanced roughness and hydrophobicity) and enhance EPS growth rates. Improved understanding of the effects of scaling, biofouling, aging and microbial population shifts on the decrease in aeration efficiency is provided. Copyright © 2018 Elsevier B.V. All rights reserved.

Efficient Sky-Blue Perovskite Light-Emitting Devices Based on Ethylammonium Bromide Induced Layered Perovskites.

PubMed

Wang, Qi; Ren, Jie; Peng, Xue-Feng; Ji, Xia-Xia; Yang, Xiao-Hui

2017-09-06

Low-dimensional organometallic halide perovskites are actively studied for the light-emitting applications due to their properties such as solution processability, high luminescence quantum yield, large exciton binding energy, and tunable band gap. Introduction of large-group ammonium halides not only serves as a convenient and versatile method to obtain layered perovskites but also allows the exploitation of the energy-funneling process to achieve a high-efficiency light emission. Herein, we investigate the influence of the addition of ethylammonium bromide on the morphology, crystallite structure, and optical properties of the resultant perovskite materials and report that the phase transition from bulk to layered perovskite occurs in the presence of excess ethylammonium bromide. On the basis of this strategy, we report green perovskite light-emitting devices with the maximum external quantum efficiency of ca. 3% and power efficiency of 9.3 lm/W. Notably, blue layered perovskite light-emitting devices with the Commission Internationale de I'Eclairage coordinates of (0.16, 0.23) exhibit the maximum external quantum efficiency of 2.6% and power efficiency of 1 lm/W at 100 cd/m 2 , representing a large improvement over the previously reported analogous devices.

The contribution of bends and constrictions of a superconducting film to the photon detection by a single-photon superconducting detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zotova, A. N., E-mail: zotova@imp.sci-nnov.ru

2016-05-15

The contribution of bends and constrictions by a superconducting film to the detection by a single photon superconducting detector is investigated. It has been shown that, for currents smaller than the minimal detection current of a straight film, the detection efficiency of a film with a constriction attains saturation upon an increase in the current, which coincides qualitatively with the behavior of this dependence observed in the experiment. It has also been found that the effect of bends in the film and the external magnetic field on the detection efficiency for low-energy photons is essential, while for high-energy photons nomore » such influence is observed.« less

Creep feeding nursing beef calves.

PubMed

Lardy, Gregory P; Maddock, Travis D

2007-03-01

Creep feeding can be used to increase calf weaning weights. However, the gain efficiency of free-choice, energy-based creep feeds is relatively poor. Generally, limit-feeding, high-protein creep feeds are more efficient, and gains may be similar to those produced by creep feeds offered free choice. Creep feeding can increase total organic matter intake and improve the overall energy status of the animal. Creep-fed calves tend to acclimate to the feedlot more smoothly than unsupplemented calves. Furthermore, provision of a high-starch creep feed may have a positive influence on subsequent carcass quality traits. Creep feeding can be applied to numerous environmental situations to maximize calf performance; however, beef cattle producers should consider their individual situations carefully before making the decision to creep feed.

Scale model performance test investigation of mixed flow exhaust systems for an energy efficient engine /E3/ propulsion system

NASA Technical Reports Server (NTRS)

Kuchar, A. P.; Chamberlin, R.

1983-01-01

As part of the NASA Energy Efficient Engine program, scale-model performance tests of a mixed flow exhaust system were conducted. The tests were used to evaluate the performance of exhaust system mixers for high-bypass, mixed-flow turbofan engines. The tests indicated that: (1) mixer penetration has the most significant affect on both mixing effectiveness and mixer pressure loss; (2) mixing/tailpipe length improves mixing effectiveness; (3) gap reduction between the mixer and centerbody increases high mixing effectiveness; (4) mixer cross-sectional shape influences mixing effectiveness; (5) lobe number affects mixing degree; and (6) mixer aerodynamic pressure losses are a function of secondary flows inherent to the lobed mixer concept.

Neutron Transport Models and Methods for HZETRN and Coupling to Low Energy Light Ion Transport

NASA Technical Reports Server (NTRS)

Blattnig, S.R.; Slaba, T.C.; Heinbockel, J.H.

2008-01-01

Exposure estimates inside space vehicles, surface habitats, and high altitude aircraft exposed to space radiation are highly influenced by secondary neutron production. The deterministic transport code HZETRN has been identified as a reliable and efficient tool for such studies, but improvements to the underlying transport models and numerical methods are still necessary. In this paper, the forward-backward (FB) and directionally coupled forward-backward (DC) neutron transport models are derived, numerical methods for the FB model are reviewed, and a computationally efficient numerical solution is presented for the DC model. Both models are compared to the Monte Carlo codes HETCHEDS and FLUKA, and the DC model is shown to agree closely with the Monte Carlo results. Finally, it is found in the development of either model that the decoupling of low energy neutrons from the light ion (A<4) transport procedure adversely affects low energy light ion fluence spectra and exposure quantities. A first order correction is presented to resolve the problem, and it is shown to be both accurate and efficient.

Perfect quantum excitation energy transport via single edge perturbation in a complete network

NASA Astrophysics Data System (ADS)

Bassereh, Hassan; Salari, Vahid; Shahbazi, Farhad; Ala-Nissila, Tapio

2017-06-01

We consider quantum excitation energy transport (EET) in a network of two-state nodes in the Markovian approximation by employing the Lindblad formulation. We find that EET from an initial site, where the excitation is inserted to the sink, is generally inefficient due to the inhibition of transport by localization of the excitation wave packet in a symmetric, fully-connected network. We demonstrate that the EET efficiency can be significantly increased up to ≈100% by perturbing hopping transport between the initial node and the one connected directly to the sink, while the rate of energy transport is highest at a finite value of the hopping parameter. We also show that prohibiting hopping between the other nodes which are not directly linked to the sink does not improve the efficiency. We show that external dephasing noise in the network plays a constructive role for EET in the presence of localization in the network, while in the absence of localization it reduces the efficiency of EET. We also consider the influence of off-diagonal disorder in the hopping parameters of the network.

The efficiency of the heat pump water heater, during DHW tapping cycle

NASA Astrophysics Data System (ADS)

Gużda, Arkadiusz; Szmolke, Norbert

2017-10-01

This paper discusses one of the most effective systems for domestic hot water (DHW) production based on air-source heat pump with an integrated tank. The operating principle of the heat pump is described in detail. Moreover, there is an account of experimental set-up and results of the measurements. In the experimental part, measurements were conducted with the aim of determining the energy parameters and measures of the economic efficiency related to the presented solution. The measurements that were conducted are based on the tapping cycle that is similar to the recommended one in EN-16147 standard. The efficiency of the air source heat pump during the duration of the experiment was 2.43. In the end of paper, authors conducted a simplified ecological analysis in order to determine the influence of operation of air-source heat pump with integrated tank on the environment. Moreover the compression with the different source of energy (gas boiler with closed combustion chamber and boiler fired by the coal) was conducted. The heat pump is the ecological friendly source of the energy.

The Influence of Shape on the Output Potential of ZnO Nanostructures: Sensitivity to Parallel versus Perpendicular Forces.

PubMed

Cardoso, José; Oliveira, Filipe F; Proenca, Mariana P; Ventura, João

2018-05-22

With the consistent shrinking of devices, micro-systems are, nowadays, widely used in areas such as biomedics, electronics, automobiles, and measurement devices. As devices shrunk, so too did their energy consumptions, opening the way for the use of nanogenerators (NGs) as power sources. In particular, to harvest energy from an object's motion (mechanical vibrations, torsional forces, or pressure), present NGs are mainly composed of piezoelectric materials in which, upon an applied compressive or strain force, an electrical field is produced that can be used to power a device. The focus of this work is to simulate the piezoelectric effect in different ZnO nanostructures to optimize the output potential generated by a nanodevice. In these simulations, cylindrical nanowires, nanomushrooms, and nanotrees were created, and the influence of the nanostructures' shape on the output potential was studied as a function of applied parallel and perpendicular forces. The obtained results demonstrated that the output potential is linearly proportional to the applied force and that perpendicular forces are more efficient in all structures. However, nanotrees were found to have an increased sensitivity to parallel applied forces, which resulted in a large enhancement of the output efficiency. These results could then open a new path to increase the efficiency of piezoelectric nanogenerators.

Analysis of Consequences of Using Gas Fuels for Running Auxiliary Ship Boilers in the Light of Contemporary Environmental Protection Requirements

NASA Astrophysics Data System (ADS)

Adamkiewicz, Andrzej; Bartoszewski, Marek; Kendra, Martin

2016-09-01

The article justifies the application of gas fuels for supplying auxiliary ship boilers. It presents legal regulations on maritime environmental protection areas and their requirements which are in power. It shows the chronology of introduced limitations on sulphur and nitrogen dioxide emissions and thresholds of carbon dioxide emission reduction expressed by EEDI (Energy Efficiency Design Indicator) and EEOI (Energy Efficiency Operational Indicator). Ways to decrease the values of EEDI and EEOI in the ship energy effectiveness management have been shown. Consequences of replacing marine fuels with LNG for running auxiliary ship boilers have been considered thoroughly, taking into account ecological, constructional, operational, procedural and logistic limitations as well as economic consequences. The summary shows the influence of particular consequences of using LNG for running boilers on the methods of maintenance of auxiliary boilers.

Analysis of exergy efficiency of a super-critical compressed carbon dioxide energy-storage system based on the orthogonal method.

PubMed

He, Qing; Hao, Yinping; Liu, Hui; Liu, Wenyi

2018-01-01

Super-critical carbon dioxide energy-storage (SC-CCES) technology is a new type of gas energy-storage technology. This paper used orthogonal method and variance analysis to make significant analysis on the factors which would affect the thermodynamics characteristics of the SC-CCES system and obtained the significant factors and interactions in the energy-storage process, the energy-release process and the whole energy-storage system. Results have shown that the interactions in the components have little influence on the energy-storage process, the energy-release process and the whole energy-storage process of the SC-CCES system, the significant factors are mainly on the characteristics of the system component itself, which will provide reference for the optimization of the thermal properties of the energy-storage system.

Analysis of exergy efficiency of a super-critical compressed carbon dioxide energy-storage system based on the orthogonal method

PubMed Central

He, Qing; Liu, Hui; Liu, Wenyi

2018-01-01

Super-critical carbon dioxide energy-storage (SC-CCES) technology is a new type of gas energy-storage technology. This paper used orthogonal method and variance analysis to make significant analysis on the factors which would affect the thermodynamics characteristics of the SC-CCES system and obtained the significant factors and interactions in the energy-storage process, the energy-release process and the whole energy-storage system. Results have shown that the interactions in the components have little influence on the energy-storage process, the energy-release process and the whole energy-storage process of the SC-CCES system, the significant factors are mainly on the characteristics of the system component itself, which will provide reference for the optimization of the thermal properties of the energy-storage system. PMID:29634742

Design of a hybrid power system based on solar cell and vibration energy harvester

NASA Astrophysics Data System (ADS)

Zhang, Bin; Li, Mingxue; Zhong, Shaoxuan; He, Zhichao; Zhang, Yufeng

2018-03-01

Power source has become a serious restriction of wireless sensor network. High efficiency, self-energized and long-life renewable source is the optimum solution for unmanned sensor network applications. However, single renewable power source can be easily affected by ambient environment, which influences stability of the system. In this work, a hybrid power system consists of a solar panel, a vibration energy harvester and a lithium battery is demonstrated. The system is able to harvest multiple types of ambient energy, which extends its applicability and feasibility. Experiments have been conducted to verify performance of the system.

School meals: a nutritional and environmental perspective.

PubMed

Demas, Antonia; Kindermann, Dana; Pimentel, David

2010-01-01

In light of the rise in childhood obesity rates and the influence of the food system on fossil fuel use, this article analyzes current school meals in Baltimore and makes suggestions for school meal reform based on both childhood nutrition and environmental resource use. The nutrient content and estimated energy costs of a typical school lunch are compared with a proposed alternate meal. The study indicates that healthier meals can significantly limit fossil fuel energy inputs for harvesting, production, processing, packaging, and transportation. The authors also provide strategies for developing menus that are both more nutritious and more energy efficient.

Experimental Evaluation of Balance Prediction Models for Sit-to-Stand Movement in the Sagittal Plane

PubMed Central

Pena Cabra, Oscar David; Watanabe, Takashi

2013-01-01

Evaluation of balance control ability would become important in the rehabilitation training. In this paper, in order to make clear usefulness and limitation of a traditional simple inverted pendulum model in balance prediction in sit-to-stand movements, the traditional simple model was compared to an inertia (rotational radius) variable inverted pendulum model including multiple-joint influence in the balance predictions. The predictions were tested upon experimentation with six healthy subjects. The evaluation showed that the multiple-joint influence model is more accurate in predicting balance under demanding sit-to-stand conditions. On the other hand, the evaluation also showed that the traditionally used simple inverted pendulum model is still reliable in predicting balance during sit-to-stand movement under non-demanding (normal) condition. Especially, the simple model was shown to be effective for sit-to-stand movements with low center of mass velocity at the seat-off. Moreover, almost all trajectories under the normal condition seemed to follow the same control strategy, in which the subjects used extra energy than the minimum one necessary for standing up. This suggests that the safety considerations come first than the energy efficiency considerations during a sit to stand, since the most energy efficient trajectory is close to the backward fall boundary. PMID:24187580

Defects with deep levels in a semiconductor structure of a photoelectric converter of solar energy with an antireflection film of porous silicon

NASA Astrophysics Data System (ADS)

Tregulov, V. V.; Litvinov, V. G.; Ermachikhin, A. V.

2017-11-01

Defects in a semiconductor structure of a photoelectric converter of solar energy based on a p-n junction with an antireflection film of porous silicon on the front surface have been studied by current deeplevel transient spectroscopy. An explanation of the influence of thickness of a porous-silicon film formed by electrochemical etching on the character of transformation of defects with deep levels and efficiency of solarenergy conversion is proposed.

Experiences of a grid connected solar array energy production

NASA Astrophysics Data System (ADS)

Hagymássy, Zoltán; Vántus, András

2015-04-01

Solar energy possibilities of Hungary are higher than in Central Europe generally. The Institute for Land Utilisation, Technology and Regional Development of the University of Debrecen installed a photovoltaic (PV) system. The PV system is structured into 3 subsystems (fields). The first subsystem has 24 pieces of Kyocera KC 120 W type modules, the second subsystem has 72 pieces of Siemens ST 40W, and the remaining has 72 pieces of Dunasolar DS 40W In order to be operable independently of each other three inverter modules (SB 2500) had been installed. The recorder can be connected directly to a desktop PC. Operating and meteorological dates are recorded by MS Excel every 15 minutes. The power plant is connected to a weather station, which contents a PT 100 type temperature and humidity combined measuring instrument, a CM 11 pyranometer, and a wind speed measuring instrument. The produced DC, and AC power, together with the produced energy are as well, and the efficiency can be determined for each used PV technology. The measured operating and meteorological dates are collected by Sunny Boy Control, produced by the SMA. The energy productions of the subsystems are measured continually and the subsystems are measured separately. As an expected, the produced energy of polycrystalline -Si PV module and monocrystalline -Si PV was higher than amorphous-Si PV module. It is well known that energy analysis is more suitable for energy balance when we design a system. The air temperature and the temperature of the panels and the global irradiation conditions were measured. In summertime the panel temperature reaches 60-80 degrees in a sunny day. The panel temperatures are in a spring sunny day approximately 30-40 degrees. It can be concluded that the global irradiation is a major impact feature to influence the amount of energy produced. The efficiency depends on several parameters (spectral distribution of the incoming light, temperature values, etc.). The energy efficiency of a PV system in general can be defined as the ratio of the output energy of the system to the input energy received on the photovoltaic surface. As an expected, the energy efficiencies of polycrystalline -Si PV module and monocrystalline -Si PV was higher than amorphous-Si PV module. Based on our study, in general it can be concluded that the energy efficiency is lower than theoretical.

U.S. energy sector impacts of technology innovation, fuel price, and electric sector CO 2 policy: Results from the EMF 32 model intercomparison study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hodson, Elke L.; Brown, Maxwell; Cohen, Stuart

We study the impact of achieving technology innovation goals, representing significant technology cost reductions and performance improvements, in both the electric power and end-use sectors by comparing outputs from four energy-economic models through the year 2050. We harmonize model input assumptions and then compare results in scenarios that vary natural gas prices, technology cost and performance metrics, and the implementation of a representative national electricity sector carbon dioxide (CO 2) policy. Achieving the representative technology innovation goals decreases CO 2 emissions in all models, regardless of natural gas price, due to increased energy efficiency and low-carbon generation becoming more costmore » competitive. For the models that include domestic natural gas markets, achieving the technology innovation goals lowers wholesale electricity prices, but this effect diminishes as projected natural gas prices increase. Higher natural gas prices lead to higher wholesale electricity prices but fewer coal capacity retirements. Some of the models include energy efficiency improvements as part of achieving the high-technology goals. Absent these energy efficiency improvements, low-cost electricity facilitates greater electricity consumption. The effect of implementing a representative electricity sector CO 2 policy differs considerably depending on the cost and performance of generating and end-use technologies. The CO 2 policy influences electric sector evolution in the cases with reference technology assumptions but has little to no influence in the cases that achieve the technology innovation goals. This outcome implies that meeting the representative technology innovation goals achieves a generation mix with similar CO 2 emissions to the representative CO 2 policy but with smaller increases to wholesale electricity prices. Finally, higher natural gas prices, achieving the representative technology innovation goals, and the combination of the two, increases the amount of renewable generation that is cost-effective to build and operate while slowing the growth of natural-gas fired generation, which is the predominant generation type in 2050 under reference conditions.« less

Experimental investigation of a packed bed thermal energy storage system

NASA Astrophysics Data System (ADS)

Cascetta, Mario; Cau, Giorgio; Puddu, Pierpaolo; Serra, Fabio

2015-11-01

In this work experimental investigations on a thermal energy storage system with a solid material as storage media and air as heat transfer fluid will be presented. The experimental test rig, installed at the DIMCM of the University of Cagliari, consists of a carbon steel tank filled with freely poured alumina beads that allows investigations of heat transfer phenomena in packed beds. The aim of this work is to show the influence of the operating conditions and physical parameters on thermocline formation and, in particular, the thermal behaviour of the thermal energy storage for repeated charging and discharging cycles. Better charging efficiency is obtained for lower values of mass flow rate and maximum air temperature and for increasing aspect ratio. A decreasing influence of the metal wall with continuous operation is also highlighted. In conclusion, the analysis focuses on the thermal hysteresis phenomenon, which causes degradation of the thermocline and the reduction of the energy that can be stored by the accumulator as the repeated number of cycles increases.

Barriers to electric energy efficiency in Ghana

NASA Astrophysics Data System (ADS)

Berko, Joseph Kofi, Jr.

Development advocates argue that sustainable development strategies are the best means to permanently improve living standards in developing countries. Advocates' arguments are based on the technical, financial, and environmental advantages of sustainable development. However, they have not addressed the organizational and administrative decision-making issues which are key to successful implementation of sustainable development in developing countries. Using the Ghanaian electricity industry as a case study, this dissertation identifies and analyzes organizational structures, administrative mechanisms, and decision-maker viewpoints that critically affect the success of adoption and implementation of energy efficiency within a sustainable development framework. Utilizing semi-structured interviews in field research, decision-makers' perceptions of the pattern of the industry's development, causes of the electricity supply shortfall, and barriers to electricity-use efficiency were identified. Based on the initial findings, the study formulated a set of policy initiatives to establish support for energy use efficiency. In a second set of interviews, these policy suggestions were presented to some of the top decision-makers to elicit their reactions. According to the decision-makers, the electricity supply shortfall is due to rapid urbanization and increased industrial consumption as a result of the structural adjustment program, rural electrification, and the sudden release of suppressed loads. The study found a lack of initiative and collaboration among industry decision-makers, and a related divergence in decision-makers' concerns and viewpoints. Also, lacking are institutional support systems and knowledge of proven energy efficiency strategies and technologies. As a result, planning, and even the range of perceived solutions to choose from are supply-side oriented. The final chapter of the study presents implications of its findings and proposes that any implementation strategy will have to address the different decision-makers' concerns and viewpoints. These include the need for national policies to promote electric energy efficiency and institutional development to provide support, guidance and direction to an energy efficiency effort. It also proposes structural changes within the industry to reduce government influence by creating an independent regulatory board. Finally, it proposes the adoption of integrated resource planning strategies and changes in the supply-side dominated culture within the electric utilities.

Cooperative Game-Based Energy Efficiency Management over Ultra-Dense Wireless Cellular Networks

PubMed Central

Li, Ming; Chen, Pengpeng; Gao, Shouwan

2016-01-01

Ultra-dense wireless cellular networks have been envisioned as a promising technique for handling the explosive increase of wireless traffic volume. With the extensive deployment of small cells in wireless cellular networks, the network spectral efficiency (SE) is improved with the use of limited frequency. However, the mutual inter-tier and intra-tier interference between or among small cells and macro cells becomes serious. On the other hand, more chances for potential cooperation among different cells are introduced. Energy efficiency (EE) has become one of the most important problems for future wireless networks. This paper proposes a cooperative bargaining game-based method for comprehensive EE management in an ultra-dense wireless cellular network, which highlights the complicated interference influence on energy-saving challenges and the power-coordination process among small cells and macro cells. Especially, a unified EE utility with the consideration of the interference mitigation is proposed to jointly address the SE, the deployment efficiency (DE), and the EE. In particular, closed-form power-coordination solutions for the optimal EE are derived to show the convergence property of the algorithm. Moreover, a simplified algorithm is presented to reduce the complexity of the signaling overhead, which is significant for ultra-dense small cells. Finally, numerical simulations are provided to illustrate the efficiency of the proposed cooperative bargaining game-based and simplified schemes. PMID:27649170

Cooperative Game-Based Energy Efficiency Management over Ultra-Dense Wireless Cellular Networks.

PubMed

Li, Ming; Chen, Pengpeng; Gao, Shouwan

2016-09-13

Ultra-dense wireless cellular networks have been envisioned as a promising technique for handling the explosive increase of wireless traffic volume. With the extensive deployment of small cells in wireless cellular networks, the network spectral efficiency (SE) is improved with the use of limited frequency. However, the mutual inter-tier and intra-tier interference between or among small cells and macro cells becomes serious. On the other hand, more chances for potential cooperation among different cells are introduced. Energy efficiency (EE) has become one of the most important problems for future wireless networks. This paper proposes a cooperative bargaining game-based method for comprehensive EE management in an ultra-dense wireless cellular network, which highlights the complicated interference influence on energy-saving challenges and the power-coordination process among small cells and macro cells. Especially, a unified EE utility with the consideration of the interference mitigation is proposed to jointly address the SE, the deployment efficiency (DE), and the EE. In particular, closed-form power-coordination solutions for the optimal EE are derived to show the convergence property of the algorithm. Moreover, a simplified algorithm is presented to reduce the complexity of the signaling overhead, which is significant for ultra-dense small cells. Finally, numerical simulations are provided to illustrate the efficiency of the proposed cooperative bargaining game-based and simplified schemes.

High Energy Conversion Efficiency with 3-D Micro-Patterned Photoanode for Enhancement Diffusivity and Modification of Photon Distribution in Dye-Sensitized Solar Cells.

PubMed

Yun, Min Ju; Sim, Yeon Hyang; Cha, Seung I; Seo, Seon Hee; Lee, Dong Y

2017-11-08

Dye sensitize solar cells (DSSCs) have been considered as the promising alternatives silicon based solar cell with their characteristics including high efficiency under weak illumination and insensitive power output to incident angle. Therefore, many researches have been studied to improve the energy conversion efficiency of DSSCs. However the efficiency of DSSCs are still trapped at the around 10%. In this study, micro-scale hexagonal shape patterned photoanode have proposed to modify light distribution of photon. In the patterned electrode, the appearance efficiency have been obtained from 7.1% to 7.8% considered active area and the efficiency of 12.7% have been obtained based on the photoanode area. Enhancing diffusion of electrons and modification of photon distribution utilizing the morphology of the electrode are major factors to improving the performance of patterned electrode. Also, finite element method analyses of photon distributions were conducted to estimate morphological effect that influence on the photon distribution and current density. From our proposed study, it is expecting that patterned electrode is one of the solution to overcome the stagnant efficiency and one of the optimized geometry of electrode to modify photon distribution. Process of inter-patterning in photoanode has been minimized.

Broadband down-conversion based near infrared quantum cutting in Eu{sup 2+}–Yb{sup 3+} co-doped SrAl{sub 2}O{sub 4} for crystalline silicon solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tai, Yuping, E-mail: yupingtai@126.com; Zheng, Guojun, E-mail: zhengguojun88@126.com; Wang, Hui, E-mail: huiwang@nwu.edu.cn

2015-03-15

Near infrared (NIR) quantum cutting involving the down conversion of an absorbed visible photon to emission of two NIR photons was achieved in SrAl{sub 2}O{sub 4}:0.01Eu{sup 2+}, xYb{sup 3+} (x=0, 1, 2, 5, 10, 20, 30 mol%) samples. The photoluminescence properties of samples in visible and NIR regions were measured to verify the energy transfer (ET) from Eu{sup 2+} to Yb{sup 3+}. The results demonstrated that Eu{sup 2+} was an efficient sensitizer for Yb{sup 3+} in the SrAl{sub 2}O{sub 4} host lattice. According to Gaussian fitting analysis and temperature-dependent luminescence experiments, the conclusion was drawn that the cooperative energy transfermore » (CET) process dominated the ET process and the influence of charge transfer state (CTS) of Yb{sup 3+} could be negligible. As a result, the high energy transfer efficiency (ETE) and quantum yield (QY) have been acquired, the maximum value approached 73.68% and 147.36%, respectively. Therefore, this down-conversion material has potential application in crystalline silicon solar cells to improve conversion efficiency. - Graphical abstract: Near infrared quantum cutting was achieved in Eu{sup 2+}–Yb{sup 3+} co-doped SrAl{sub 2}O{sub 4} samples. The cooperative energy transfer process dominated energy transfer process and high energy transfer efficiency was acquired. - Highlights: • The absorption spectrum of Eu{sup 2+} ion is strong in intensity and broad in bandwidth. • The spectra of Eu{sup 2+} in SrAl{sub 2}O{sub 4} lies in the strongest region of solar spectrum. • The cooperative energy transfer (CET) dominated the energy transfer process. • The domination of CET is confirmed by experimental analysis. • SrAl{sub 2}O{sub 4}:Eu{sup 2+},Yb{sup 3+} show high energy transfer efficiency and long lifetime.« less

Barriers to Building Energy Efficiency (BEE) promotion: A transaction costs perspective

NASA Astrophysics Data System (ADS)

Qian Kun, Queena

Worldwide, buildings account for a surprisingly high 40% of global energy consumption, and the resulting carbon footprint significantly exceeds that of all forms of transportation combined. Large and attractive opportunities exist to reduce buildings' energy use at lower costs and higher returns than in other sectors. This thesis analyzes the concerns of the market stakeholders, mainly real estate developers and end-users, in terms of transaction costs as they make decisions about investing in Building Energy Efficiency (BEE). It provides a detailed analysis of the current situation and future prospects for BEE adoption by the market's stakeholders. It delineates the market and lays out the economic and institutional barriers to the large-scale deployment of energy-efficient building techniques. The aim of this research is to investigate the barriers raised by transaction costs that hinder market stakeholders from investing in BEES. It explains interactions among stakeholders in general and in the specific case of Hong Kong as they consider transaction costs. It focuses on the influence of transaction costs on the decision-making of the stakeholders during the entire process of real estate development. The objectives are: 1) To establish an analytical framework for understanding the barriers to BEE investment with consideration of transaction costs; 2) To build a theoretical game model of decision making among the BEE market stakeholders; 3) To study the empirical data from questionnaire surveys of building designers and from focused interviews with real estate developers in Hong Kong; 4) To triangulate the study's empirical findings with those of the theoretical model and analytical framework. The study shows that a coherent institutional framework needs to be established to ensure that the design and implementation of BEE policies acknowledge the concerns of market stakeholders by taking transaction costs into consideration. Regulatory and incentive options should be integrated into BEE policies to minimize efficiency gaps and to realize a sizeable increase in the number of energy-efficient buildings in the next decades. Specifically, the analysis shows that a thorough understanding of the transaction costs borne by particular stakeholders could improve the energy efficiency of buildings, even without improvements in currently available technology.

Energy Consumption and Greenhouse Gas Emission of Korean Offshore Fisheries

NASA Astrophysics Data System (ADS)

Lee, Jihoon; Kim, Taeho; Ellingsen, Harald; Hognes, Erik Skontorp; Hwang, Bokyu

2018-06-01

This paper presents the energy and greenhouse gas (GHG) emission assessments of Korean offshore fisheries. The consumption of energy by fisheries is a significant concern because of its attendant environmental effect, as well as the cost of the fuel consumed in fishing industry. With the global attention of reducing GHG emission and increasing energy efficiency of fuel, the seafood industry needs to further understand its energy use and reduce its GHG emission. In the present study, the amount of energy consumed and the GHG emission of Korean offshore fisheries in a period from 2009 to 2013 were examined. Offshore fisheries accounted for 24% of Korean production in 2013 and 60% of fuel consumption related GHG emission. Whereas the total GHG emission intensity of this sector improved slightly between 2009 and 2012; as such emission decreased by approximately 1.9%, which increased again in 2013. The average amount of total GHG emission in this five years period was 1.78 × 106 tons of carbon dioxide equivalent/year (t CO2 eq. y-1). Active fishing gear was found to consume 20% more fuel than passive gear. However, the production from passive gear was 28%, lower than 72% from active gear. The reason for this is that less abundant stationary resources are harvested using passive gear. Furthermore, the consumption of fuel was significantly influenced by the fishing method. Implementation and development of new fishing technologies and methods are important for improving energy efficiency and reducing the climate impact on fisheries. To realize these purposes, the fishery management system needs to be established by centralizing on energy efficiency and climate effect.

An efficient low frequency horizontal diamagnetic levitation mechanism based vibration energy harvester

NASA Astrophysics Data System (ADS)

Palagummi, S.; Yuan, F. G.

2016-04-01

This article identifies and studies key parameters that characterize a horizontal diamagnetic levitation (HDL) mechanism based low frequency vibration energy harvester with the aim of enhancing performance metrics such as efficiency and volume figure of merit (FoMv). The HDL mechanism comprises of three permanent magnets and two diamagnetic plates. Two of the magnets, aka lifting magnets, are placed co-axially at a distance such that each attract a centrally located magnet, aka floating magnet, to balance its weight. This floating magnet is flanked closely by two diamagnetic plates which stabilize the levitation in the axial direction. The influence of the geometry of the floating magnet, the lifting magnet and the diamagnetic plate are parametrically studied to quantify their effects on the size, stability of the levitation mechanism and the resonant frequency of the floating magnet. For vibration energy harvesting using the HDL mechanism, a coil geometry and eddy current damping are critically discussed. Based on the analysis, an efficient experimental system is setup which showed a softening frequency response with an average system efficiency of 25.8% and a FoMv of 0.23% when excited at a root mean square acceleration of 0.0546 m/s2 and at frequency of 1.9 Hz.

Towards greener environment: Energy efficient pathways for the transportation sector in Malaysia

NASA Astrophysics Data System (ADS)

Indati, M. S.; Ghate, A. T.; Leong, Y. P.

2013-06-01

Transportation sector is the second most energy consuming sector after industrial sector, accounting for 40% of total energy consumption in Malaysia. The transportation sector is one of the most energy intensive sectors in the country and relies primarily on petroleum products, which in total account for nearly 98% of the total consumption in the sector. Since it is heavily reliant on petroleum based fuels, the sector contributes significantly to the greenhouse gas (GHG) emissions. The need to reduce the greenhouse gas emission is paramount as Malaysia at Conference of the Parties (COP15) pledged to reduce its carbon intensity by 40% by 2020 from 2005 level subject to availability of technology and finance. Transport sector will be among the first sectors that need to be addressed to achieve this goal, as two-thirds of the emissions come from fuel combustion in transport sector. This paper will analyse the factors influencing the transport sector's growth and energy consumption trends and discuss the key issues and challenges for greener environment and sustainable transportation in Malaysia. The paper will also discuss the policy and strategic options aimed towards energy efficient pathways in Malaysia.

Estimating the neutrally buoyant energy density of a Rankine-cycle/fuel-cell underwater propulsion system

NASA Astrophysics Data System (ADS)

Waters, Daniel F.; Cadou, Christopher P.

2014-02-01

A unique requirement of underwater vehicles' power/energy systems is that they remain neutrally buoyant over the course of a mission. Previous work published in the Journal of Power Sources reported gross as opposed to neutrally-buoyant energy densities of an integrated solid oxide fuel cell/Rankine-cycle based power system based on the exothermic reaction of aluminum with seawater. This paper corrects this shortcoming by presenting a model for estimating system mass and using it to update the key findings of the original paper in the context of the neutral buoyancy requirement. It also presents an expanded sensitivity analysis to illustrate the influence of various design and modeling assumptions. While energy density is very sensitive to turbine efficiency (sensitivity coefficient in excess of 0.60), it is relatively insensitive to all other major design parameters (sensitivity coefficients < 0.15) like compressor efficiency, inlet water temperature, scaling methodology, etc. The neutral buoyancy requirement introduces a significant (∼15%) energy density penalty but overall the system still appears to offer factors of five to eight improvements in energy density (i.e., vehicle range/endurance) over present battery-based technologies.

Chapter 17: Residential Behavior Evaluation Protocol. The Uniform Methods Project: Methods for Determining Energy Efficiency Savings for Specific Measures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurnik, Charles W.; Stewart, James; Todd, Annika

Residential behavior-based (BB) programs use strategies grounded in the behavioral and social sciences to influence household energy use. These may include providing households with real-time or delayed feedback about their energy use; supplying energy efficiency education and tips; rewarding households for reducing their energy use; comparing households to their peers; and establishing games, tournaments, and competitions. BB programs often target multiple energy end uses and encourage energy savings, demand savings, or both. Savings from BB programs are usually a small percentage of energy use, typically less than 5 percent. Utilities will continue to implement residential BB programs as large-scale, randomizedmore » control trials (RCTs); however, some are now experimenting with alternative program designs that are smaller scale; involve new communication channels such as the web, social media, and text messaging; or that employ novel strategies for encouraging behavior change (for example, Facebook competitions). These programs will create new evaluation challenges and may require different evaluation methods than those currently employed to verify any savings they generate. Quasi-experimental methods, however, require stronger assumptions to yield valid savings estimates and may not measure savings with the same degree of validity and accuracy as randomized experiments.« less

Influence of a direct-fed microbial and xylanase enzyme on the dietary energy uptake efficiency and performance of broiler chickens.

PubMed

Murugesan, Ganapathi Raj; Persia, Michael E

2015-09-01

Efficacy of a multi-strain direct-fed microbial product (PoultryStar(®) ME; PS) and a xylanase enzyme product on the dietary energy utilization efficiency and resulting performance in broiler chickens was evaluated. Apart from performance parameters, cecal and serum metabolites and activities of hepatic enzymes involved in energy metabolism were also determined. Ross 308 chicks were fed one of four experimental diets [control (CON), CON + PS, CON + xylanase and CON + PS + xylanase] using a 2 × 2 factorial arrangement from 1-21 days of age. Cecal proportions of propionate and butyrate, as well as total short-chain fatty acid concentration were increased (P <0.01) by PS suggesting increased fermentation of dietary fiber. Both additives reduced (P <0.01) serum non-esterified free fatty acids, while PS reduced (P <0.01) serum triglyceride. Hepatic glycogen concentration was increased (P <0.01) by both additives. Changes in these serum metabolites and hepatic glycogen indicate the influence of additives in swiftly transitioning the birds from fasting to feeding metabolism. The activity of hepatic glucose-6-phosphate dehydrogenase (G6PDH) was increased (P <0.01) by PS. Elevated hepatic glycogen and G6PDH activity indicate increased glucose-sparing potential. Feed conversion ratio (FCR) was lowered by both additives, while the magnitude of reduction was higher with the combination. The combination worked synergistically, compared to their individual effects, to increase dietary energy uptake and hepatic energy retention. The combination additively increased the FCR, suggesting involvement of synergistic modes of actions. © 2014 Society of Chemical Industry.

Scale-up of a Luminescent Solar Concentrator-Based Photomicroreactor via Numbering-up.

PubMed

Zhao, Fang; Cambié, Dario; Janse, Jeroen; Wieland, Eric W; Kuijpers, Koen P L; Hessel, Volker; Debije, Michael G; Noël, Timothy

2018-01-02

The use of solar energy to power chemical reactions is a long-standing dream of the chemical community. Recently, visible-light-mediated photoredox catalysis has been recognized as the ideal catalytic transformation to convert solar energy into chemical bonds. However, scaling photochemical transformations has been extremely challenging due to Bouguer-Lambert-Beer law. Recently, we have pioneered the development of luminescent solar concentrator photomicroreactors (LSC-PMs), which display an excellent energy efficiency. These devices harvest solar energy, convert the broad solar energy spectrum to a narrow-wavelength region, and subsequently waveguide the re-emitted photons to the reaction channels. Herein, we report on the scalability of such LSC-PMs via a numbering-up strategy. Paramount in our work was the use of molds that were fabricated via 3D printing. This allowed us to rapidly produce many different prototypes and to optimize experimentally key design aspects in a time-efficient fashion. Reactors up to 32 parallel channels have been fabricated that display an excellent flow distribution using a bifurcated flow distributor (standard deviations below 10%). This excellent flow distribution was crucial to scale up a model reaction efficiently, displaying yields comparable to those obtained in a single-channel device. We also found that interchannel spacing is an important and unique design parameter for numbered-up LSC-PMs, which influences greatly the photon flux experienced within the reaction channels.

Modeling the resiliency of energy-efficient retrofits in low-income multifamily housing.

PubMed

Underhill, L J; Fabian, M P; Vermeer, K; Sandel, M; Adamkiewicz, G; Leibler, J H; Levy, J I

2018-05-01

Residential energy efficiency and ventilation retrofits (eg, building weatherization, local exhaust ventilation, HVAC filtration) can influence indoor air quality (IAQ) and occupant health, but these measures' impact varies by occupant activity. In this study, we used the multizone airflow and IAQ analysis program CONTAM to simulate the impacts of energy retrofits on indoor concentrations of PM 2.5 and NO 2 in a low-income multifamily housing complex in Boston, Massachusetts (USA). We evaluated the differential impact of residential activities, such as low- and high-emission cooking, cigarette smoking, and window opening, on IAQ across two seasons. We found that a comprehensive package of energy and ventilation retrofits was resilient to a range of occupant activities, while less holistic approaches without ventilation improvements led to increases in indoor PM 2.5 or NO 2 for some populations. In general, homes with simulated concentration increases included those with heavy cooking and no local exhaust ventilation, and smoking homes without HVAC filtration. Our analytical framework can be used to identify energy-efficient home interventions with indoor retrofit resiliency (ie, those that provide IAQ benefits regardless of occupant activity), as well as less resilient retrofits that can be coupled with behavioral interventions (eg, smoking cessation) to provide cost-effective, widespread benefits. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Scale-up of a Luminescent Solar Concentrator-Based Photomicroreactor via Numbering-up

PubMed Central

2017-01-01

The use of solar energy to power chemical reactions is a long-standing dream of the chemical community. Recently, visible-light-mediated photoredox catalysis has been recognized as the ideal catalytic transformation to convert solar energy into chemical bonds. However, scaling photochemical transformations has been extremely challenging due to Bouguer–Lambert–Beer law. Recently, we have pioneered the development of luminescent solar concentrator photomicroreactors (LSC-PMs), which display an excellent energy efficiency. These devices harvest solar energy, convert the broad solar energy spectrum to a narrow-wavelength region, and subsequently waveguide the re-emitted photons to the reaction channels. Herein, we report on the scalability of such LSC-PMs via a numbering-up strategy. Paramount in our work was the use of molds that were fabricated via 3D printing. This allowed us to rapidly produce many different prototypes and to optimize experimentally key design aspects in a time-efficient fashion. Reactors up to 32 parallel channels have been fabricated that display an excellent flow distribution using a bifurcated flow distributor (standard deviations below 10%). This excellent flow distribution was crucial to scale up a model reaction efficiently, displaying yields comparable to those obtained in a single-channel device. We also found that interchannel spacing is an important and unique design parameter for numbered-up LSC-PMs, which influences greatly the photon flux experienced within the reaction channels. PMID:29333350

Night ventilation control strategies in office buildings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhaojun; Yi, Lingli; Gao, Fusheng

2009-10-15

In moderate climates night ventilation is an effective and energy-efficient approach to improve the indoor thermal environment for office buildings during the summer months, especially for heavyweight construction. However, is night ventilation a suitable strategy for office buildings with lightweight construction located in cold climates? In order to answer this question, the whole energy-consumption analysis software EnergyPlus was used to simulate the indoor thermal environment and energy consumption in typical office buildings with night mechanical ventilation in three cities in northern China. The summer outdoor climate data was analyzed, and three typical design days were chosen. The most important factorsmore » influencing night ventilation performance such as ventilation rates, ventilation duration, building mass and climatic conditions were evaluated. When night ventilation operation time is closer to active cooling time, the efficiency of night ventilation is higher. With night ventilation rate of 10 ach, the mean radiant temperature of the indoor surface decreased by up to 3.9 C. The longer the duration of operation, the more efficient the night ventilation strategy becomes. The control strategies for three locations are given in the paper. Based on the optimized strategies, the operation consumption and fees are calculated. The results show that more energy is saved in office buildings cooled by a night ventilation system in northern China than ones that do not employ this strategy. (author)« less

A study of Ground Source Heat Pump based on a heat infiltrates coupling model established with FEFLOW

NASA Astrophysics Data System (ADS)

Chen, H.; Hu, C.; Chen, G.; Zhang, Q.

2017-12-01

Geothermal heat is a viable source of energy and its environmental impact in terms of CO2 emissions is significantly lower than conventional fossil fuels. it is vital that engineers acquire a proper understanding about the Ground Source Heat Pump (GSHP). In this study, the model of the borehole exchanger under conduction manners and heat infiltrates coupling manners was established with FEFLOW. The energy efficiency, heat transfer endurance and heat transfer in the unit depth were introduced to quantify the energy efficient and the endurance period. The performance of a the Borehole Exchanger (BHE) in soil with and without groundwater seepage was analyzed of heat transfer process between the soil and the working fluid. Basing on the model, the varied regularity of energy efficiency performance an heat transfer endurance with the conditions including the different configuration of the BHE, the soil properties, thermal load characteristic were discussed. Focus on the heat transfer process in multi-layer soil which one layer exist groundwater flow. And an investigation about thermal dispersivity was also analyzed its influence on heat transfer performance. The final result proves that the model of heat infiltrates coupling model established in this context is reasonable, which can be applied to engineering design.

Reducing domestic heating demand: Managing the impact of behavior-changing feedback devices via marketing.

PubMed

Jensen, Thorben; Chappin, Émile J L

2017-07-15

Feedback devices can be used to inform households about their energy-consumption behavior. This may persuade them to practice energy conservation. The use of feedback devices can also-via word of mouth-spread among households and thereby support the spread of the incentivized behavior, e.g. energy-efficient heating behavior. This study investigates how to manage the impact of these environmental innovations via marketing. Marketing activities can support the diffusion of devices. This study aims to identify the most effective strategies of marketing feedback devices. We did this by adapting an agent-based model to simulate the roll-out of a novel feedback technology and heating behavior within households in a virtual city. The most promising marketing strategies were simulated and their impacts were analyzed. We found it particularly effective to lend out feedback devices to consumers, followed by leveraging the social influence of well-connected individuals, and giving away the first few feedback devices for free. Making households aware of the possibility of purchasing feedback devices was found to be least effective. However, making households aware proved to be most cost-efficient. This study shows that actively managing the roll-out of feedback devices can increase their impacts on energy-conservation both effectively and cost-efficiently. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pyridinium molten salts as co-adsorbents in dye-sensitized solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Jui-Cheng; Sun, I-Wen; Yang, Cheng-Hsien

2011-01-15

The influence of using pyridinium molten salts as co-adsorbents to modify the monolayer of a TiO{sub 2} semiconductor on the performance of a dye-sensitized solar cell is studied. The current-voltage characteristics are measured under AM 1.5 (100 mW cm{sup -2}). The pyridinium molten salts significantly enhance the open-circuit photovoltage (V{sub oc}), the short circuit photocurrent density (J{sub sc}) as well as the solar energy conversion efficiency ({eta}). 1-Ethyl-3-carboxypyridinium iodide ([ECP][I]) is applied successfully to prepare an insulating molecular layer with N719, and achieve high energy conversion efficiency as high as 4.49% at 100 mW cm{sup -2} and AM 1.5. Themore » resulting efficiency is 20% higher than that of a non-additive device. This enhancement of conversion efficiency is attributed to the negative shift of the conduction band (CB) edge and the abundant concentration of I{sup -} on the surface of the electrode when using [ECP][I] as the co-adsorbent. (author)« less

Modeling recombination processes and predicting energy conversion efficiency of dye sensitized solar cells from first principles

NASA Astrophysics Data System (ADS)

Ma, Wei; Meng, Sheng

2014-03-01

We present a set of algorithms based on solo first principles calculations, to accurately calculate key properties of a DSC device including sunlight harvest, electron injection, electron-hole recombination, and open circuit voltages. Two series of D- π-A dyes are adopted as sample dyes. The short circuit current can be predicted by calculating the dyes' photo absorption, and the electron injection and recombination lifetime using real-time time-dependent density functional theory (TDDFT) simulations. Open circuit voltage can be reproduced by calculating energy difference between the quasi-Fermi level of electrons in the semiconductor and the electrolyte redox potential, considering the influence of electron recombination. Based on timescales obtained from real time TDDFT dynamics for excited states, the estimated power conversion efficiency of DSC fits nicely with the experiment, with deviation below 1-2%. Light harvesting efficiency, incident photon-to-electron conversion efficiency and the current-voltage characteristics can also be well reproduced. The predicted efficiency can serve as either an ideal limit for optimizing photovoltaic performance of a given dye, or a virtual device that closely mimicking the performance of a real device under different experimental settings.

Stack developments in a kW class all vanadium mixed acid redox flow battery at the Pacific Northwest National Laboratory

DOE PAGES

Reed, David M.; Thomsen, Edwin C.; Li, Bin; ...

2015-11-21

Over the past several years, efforts have been focused on improving the performance of kW class stacks with increasing current density. The influence of the Nafion membrane resistance, an interdigitated design to reduce the pressure drop in the electrolyte circuit, the temperature of the electrolyte, and the electrode structure will be discussed and correlated to the electrical performance. Furthermore, improvements to the stack energy efficiency and how those translate to the overall system efficiency will also be discussed.

Induced innovation, energy prices, and the environment

NASA Astrophysics Data System (ADS)

Popp, David Clifford

The process of developing new technologies is a central question for economic theory as well as for public policy in many areas. For example, the development of cleaner, more efficient energy technologies will play an important role in reducing the threat of global warming. To study how technology evolves over time, this dissertation uses patent data on energy innovations from 1970 to 1991 to examine the impact of energy prices on energy-efficient innovations. Before this can be done, however, information on supply-side factors which influence innovation is also needed. In the case of innovation, supply-side factors are the usefulness of the existing base of scientific knowledge. Patent citations are used for this purpose. Subsequent citations to patents granted each year since 1970 are used to show that the returns to research and development (R&D) fall over time for most of the technologies studied. These estimates are then combined with data on demand-side factors, such as energy prices, to estimate a model of induced innovation in energy technologies. Both energy prices and the supply of knowledge are found to have strongly significant positive effects on innovation. Next, the Yale Technology Concordance (YTC), which maps patents to the industries in which they are used, is employed to construct a stock of energy-related knowledge for 14 energy intensive industries. The effect of changes in this stock on energy consumption in these industries is estimated. On average, the present value of energy savings resulting from a new patent is eight million dollars, with the maximum savings coming about five years after the initial patent application. Finally, the results of each regression are combined to simulate the impact of a ten percent energy tax. Initially, simple factor substitution due to the price change has the largest effect. However, because of the cumulative nature of R&D, induced innovation has a much larger effect than factor substitution in the long run. The evidence in this dissertation suggests that prices play an important role in influencing technological change, and that policy-makers can use this to their advantage in designing appropriate environmental policies.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reed, David; Thomsen, Edwin; Li, Bin

Three flow designs were operated in a 3-cell 1 kW class all vanadium mixed acid redox flow battery. The influence of electrode surface area and flow rate on the coulombic, voltage, and energy efficiency and the pressure drop in the flow circuit will be discussed and correlated to the flow design. Material cost associated with each flow design will also be discussed.

Biogas - the calculable energy

NASA Astrophysics Data System (ADS)

Kith, Károly; Nagy, Orsolya; Balla, Zoltán; Tamás, András

2015-04-01

EU actions against climate change are rising energy prices, both have emphasized the use of renewable energy,increase investments and energy efficiency. A number of objectives formulated in the EC decree no. 29/2009 by 2020. This document is based on the share of renewable energies in energy consumption should be increased to 20% (EC, 2009). The EU average is 20% but the share of renewables vary from one member state to another. In Hungary in 2020, 14.65% renewable energy share is planned to be achieved. According to the latest Eurostat data, the share of renewable energy in energy consumption of the EU average was 14.1%, while in Hungary, this share was 9.6% in 2012. (EUROSTAT, 2014). The use of renewable energy plant level is influenced by several factors. The most important of these is the cost savings and efficiency gains. Hungarian investments in renewable energy production usually have high associated costs and the payback period is substantially more than five years, depending on the support rate. For example, the payback period is also influenced by the green electricity generated feed prices, which is one of the lowest in Hungary compared the Member States of the European Union. Consequently, it is important to increase the production of green energy. Nowadays, predictable biogas energy is an outstanding type of decentralized energy production. It follows directly that agricultural by-products can be used to produce energy and they also create jobs by the construction of a biogas plant. It is important to dispose of and destroy hazardous and noxious substances in energy production. It follows from this that the construction of biogas plants have a positive impact, in addition to green energy which is prepared to reduce the load on the environment. The production of biogas and green electricity is one of the most environment friendly forms of energy production. Biogas production also has other important ecological effects, such as the substitution of fertilizers, reducing its use in agriculture, which protects groundwater and surface water conditions and reduces the amount of greenhouse gases in the atmosphere. In the future more emphasis should be given to increase the effectiveness of existing technologies and other types of innovation could be expanded in energy production. It can be concluded that green energy investments can be rewarding if accurate planning is carried out before the investment.

Mechanical energy transfers across lower limb segments during stair ascent and descent in young and healthy older adults.

PubMed

Novak, Alison C; Li, Qingguo; Yang, Shuozhi; Brouwer, Brenda

2011-07-01

Older adults present with altered movement patterns during stair negotiation although the extent to which modifications in pattern and speed influence mechanical efficiency is unknown. This study evaluated mechanical energy transfers attributed to active force production during stair negotiation in young and older adults to provide insight into age-related changes in mechanical efficiency. Secondary analysis on data obtained from 23 young (23.7±3.0 years) and 32 older adults (67.0±8.2 years) during self-paced stair ascent and descent was conducted. Mechanical energy expenditures (MEE) during concentric transfer, eccentric transfer and no-transfer phases were determined for the ankle, knee and hip power profiles in the sagittal plane. Mechanical energy compensations (MEC) were also determined at each joint. During ascent, MEEs were similar for young and older adults although older adults compensated ankle muscles to a lesser extent during concentric muscle action. Controlling for cadence eliminated this difference. During descent, older adults demonstrated lower energy expenditures at the ankle and hip and similar expenditures at the knee compared to young adults. Changes in joint MEE in the older group resulted in reduced energy compensation at the ankle during concentric and eccentric activity and at the knee during eccentric activity. These age-related differences in mechanical energy transfers and related adjustments in MEC were not a function of the slower cadence in older adults and suggest a loss in mechanical efficiency. These results provide a benchmark against which physical impairments in older adults may be explored. Copyright © 2011 Elsevier B.V. All rights reserved.

Investigations of fluid-strain interaction using Plate Boundary Observatory borehole data

NASA Astrophysics Data System (ADS)

Boyd, Jeffrey Michael

Software has a great impact on the energy efficiency of any computing system--it can manage the components of a system efficiently or inefficiently. The impact of software is amplified in the context of a wearable computing system used for activity recognition. The design space this platform opens up is immense and encompasses sensors, feature calculations, activity classification algorithms, sleep schedules, and transmission protocols. Design choices in each of these areas impact energy use, overall accuracy, and usefulness of the system. This thesis explores methods software can influence the trade-off between energy consumption and system accuracy. In general the more energy a system consumes the more accurate will be. We explore how finding the transitions between human activities is able to reduce the energy consumption of such systems without reducing much accuracy. We introduce the Log-likelihood Ratio Test as a method to detect transitions, and explore how choices of sensor, feature calculations, and parameters concerning time segmentation affect the accuracy of this method. We discovered an approximate 5X increase in energy efficiency could be achieved with only a 5% decrease in accuracy. We also address how a system's sleep mode, in which the processor enters a low-power state and sensors are turned off, affects a wearable computing platform that does activity recognition. We discuss the energy trade-offs in each stage of the activity recognition process. We find that careful analysis of these parameters can result in great increases in energy efficiency if small compromises in overall accuracy can be tolerated. We call this the ``Great Compromise.'' We found a 6X increase in efficiency with a 7% decrease in accuracy. We then consider how wireless transmission of data affects the overall energy efficiency of a wearable computing platform. We find that design decisions such as feature calculations and grouping size have a great impact on the energy consumption of the system because of the amount of data that is stored and transmitted. For example, storing and transmitting vector-based features such as FFT or DCT do not compress the signal and would use more energy than storing and transmitting the raw signal. The effect of grouping size on energy consumption depends on the feature. For scalar features energy consumption is proportional in the inverse of grouping size, so it's reduced as grouping size goes up. For features that depend on the grouping size, such as FFT, energy increases with the logarithm of grouping size, so energy consumption increases slowly as grouping size increases. We find that compressing data through activity classification and transition detection significantly reduces energy consumption and that the energy consumed for the classification overhead is negligible compared to the energy savings from data compression. We provide mathematical models of energy usage and data generation, and test our ideas using a mobile computing platform, the Texas Instruments Chronos watch.

Influence of the Grain Size on the Properties of CH3NH3PbI3 Thin Films.

PubMed

Shargaieva, Oleksandra; Lang, Felix; Rappich, Jörg; Dittrich, Thomas; Klaus, Manuela; Meixner, Matthias; Genzel, Christoph; Nickel, Norbert H

2017-11-08

Hybrid perovskites have already shown a huge success as an absorber in solar cells, resulting in the skyrocketing rise in the power conversion efficiency to more than η = 22%. Recently, it has been established that the crystal quality is one of the most important parameters to obtain devices with high efficiencies. However, the influence of the crystal quality on the material properties is not fully understood. Here, the influence of the morphology on electronic properties of CH 3 NH 3 PbI 3 thin films is investigated. Postannealing was used to vary the average grain size continuously from ≈150 to ≈1000 nm. Secondary grain growth is thermally activated with an activation energy of E a = 0.16 eV. The increase in the grain size leads to an enhancement of the photoluminescence, indicating an improvement in the material quality. According to surface photovoltage measurements, the charge-carrier transport length exhibits a linear increase with increasing grain size. The charge-carrier diffusion length is limited by grain boundaries. Moreover, an improved morphology leads to a drastic increase in power conversion efficiency of the devices.

Understanding the human dimensions of a sustainable energy transition.

PubMed

Steg, Linda; Perlaviciute, Goda; van der Werff, Ellen

2015-01-01

Global climate change threatens the health, economic prospects, and basic food and water sources of people. A wide range of changes in household energy behavior is needed to realize a sustainable energy transition. We propose a general framework to understand and encourage sustainable energy behaviors, comprising four key issues. First, we need to identify which behaviors need to be changed. A sustainable energy transition involves changes in a wide range of energy behaviors, including the adoption of sustainable energy sources and energy-efficient technology, investments in energy efficiency measures in buildings, and changes in direct and indirect energy use behavior. Second, we need to understand which factors underlie these different types of sustainable energy behaviors. We discuss three main factors that influence sustainable energy behaviors: knowledge, motivations, and contextual factors. Third, we need to test the effects of interventions aimed to promote sustainable energy behaviors. Interventions can be aimed at changing the actual costs and benefits of behavior, or at changing people's perceptions and evaluations of different costs and benefits of behavioral options. Fourth, it is important to understand which factors affect the acceptability of energy policies and energy systems changes. We discuss important findings from psychological studies on these four topics, and propose a research agenda to further explore these topics. We emphasize the need of an integrated approach in studying the human dimensions of a sustainable energy transition that increases our understanding of which general factors affect a wide range of energy behaviors as well as the acceptability of different energy policies and energy system changes.

Understanding the human dimensions of a sustainable energy transition

PubMed Central

Steg, Linda; Perlaviciute, Goda; van der Werff, Ellen

2015-01-01

Global climate change threatens the health, economic prospects, and basic food and water sources of people. A wide range of changes in household energy behavior is needed to realize a sustainable energy transition. We propose a general framework to understand and encourage sustainable energy behaviors, comprising four key issues. First, we need to identify which behaviors need to be changed. A sustainable energy transition involves changes in a wide range of energy behaviors, including the adoption of sustainable energy sources and energy-efficient technology, investments in energy efficiency measures in buildings, and changes in direct and indirect energy use behavior. Second, we need to understand which factors underlie these different types of sustainable energy behaviors. We discuss three main factors that influence sustainable energy behaviors: knowledge, motivations, and contextual factors. Third, we need to test the effects of interventions aimed to promote sustainable energy behaviors. Interventions can be aimed at changing the actual costs and benefits of behavior, or at changing people’s perceptions and evaluations of different costs and benefits of behavioral options. Fourth, it is important to understand which factors affect the acceptability of energy policies and energy systems changes. We discuss important findings from psychological studies on these four topics, and propose a research agenda to further explore these topics. We emphasize the need of an integrated approach in studying the human dimensions of a sustainable energy transition that increases our understanding of which general factors affect a wide range of energy behaviors as well as the acceptability of different energy policies and energy system changes. PMID:26136705

Influence of power supply on the generation of ozone and degradation of phenol in a surface discharge reactor

NASA Astrophysics Data System (ADS)

Zhao, Yan; Shang, Kefeng; Duan, Lijuan; Li, Yue; An, Jiutao; Zhang, Chunyang; Lu, Na; Li, Jie; Wu, Yan

2013-03-01

A surface Dielectric Barrier Discharge (DBD) reactor was utilized to degrade phenol in water. Different power supplies applied to the DBD reactor affect the discharge modes, the formation of chemically active species and thus the removal efficiency of pollutants. It is thus important to select an optimized power supply for the DBD reactor. In this paper, the influence of the types of power supplies including alternate current (AC) and bipolar pulsed power supply on the ozone generation in a surface discharge reactor was measured. It was found that compared with bipolar pulsed power supply, higher energy efficiency of O3 generation was obtained when DBD reactor was supplied with 50Hz AC power supply. The highest O3 generation was approximate 4 mg kJ-1 moreover, COD removal efficiency of phenol wastewater reached 52.3% after 3 h treatment under an AC peak voltage of 2.6 kV.

Research status and evaluation system of heat source evaluation method for central heating

NASA Astrophysics Data System (ADS)

Sun, Yutong; Qi, Junfeng; Cao, Yi

2018-02-01

The central heating boiler room is a regional heat source heating center. It is also a kind of the urban environment pollution, it is an important section of building energy efficiency. This article through to the evaluation method of central heating boiler room and overviews of the researches during domestic and overseas, summarized the main influence factors affecting energy consumption of industrial boiler under the condition of stable operation. According to the principle of establishing evaluation index system. We can find that is great significance in energy saving and environmental protection for the content of the evaluation index system of the centralized heating system.

Oxidation of aqueous pharmaceuticals by pulsed corona discharge.

PubMed

Panorel, Iris; Preis, Sergei; Kornev, Iakov; Hatakka, Henry; Louhi-Kultanen, Marjatta

2013-01-01

Oxidation of aromatic compounds of phenolic (paracetamol, beta-oestradiol and salicylic acid) and carboxylic (indomethacin and ibuprofen) structure used in pharmaceutics was studied. Aqueous solutions were treated with pulsed corona discharge (PCD) as a means for advanced oxidation. Pulse repetition frequency, delivered energy dose and oxidation media were the main parameters studied for their influence on the process energy efficiency. The PCD treatment appeared to be effective in oxidation of the target compounds: complete degradation of pollutant together with partial mineralization was achieved at moderate energy consumption; oxidation proceeds faster in alkaline media. Low-molecular carboxylic acids were identified as ultimate oxidation by-products formed in the reaction.

Scattering of water from the glycerol liquid-vacuum interface

NASA Technical Reports Server (NTRS)

Benjamin, I.; Wilson, M. A.; Pohorille, A.; Nathanson, G. M.

1995-01-01

Molecular dynamics calculations of the scattering of D2O from the glycerol surface at different collision energies are reported. The results for the trapping probabilities and energy transfer are in good agreement with experiments. The calculations demonstrate that the strong attractive forces between these two strongly hydrogen bonding molecules have only a minor effect on the initial collision dynamics. The trapping probability is influenced to a significant extent by the repulsive hard sphere-like initial encounter with the corrugated surface and, only at a later stage, by the efficiency of energy flow in the multiple interactions between the water and the surface molecules.

7 CFR 1710.255 - Energy efficiency work plans-energy efficiency borrowers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 11 2014-01-01 2014-01-01 false Energy efficiency work plans-energy efficiency... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.255 Energy efficiency work plans—energy efficiency borrowers. (a) All energy efficiency borrowers must maintain a...

[Lethal effect after transmutation of 33P incorporated into bacteriophage S 13 and mechanisms of DNA double helix rupture].

PubMed

Apelgot, S

1980-04-01

The experiments show the lethal effect of the beta decay of 33P incorporated in DNA of bacteriophage S 13. The lethal efficiency is high, 0.72 at 0 degrees C and 0.55 at--197 degrees C. The presence of a radical scavenger like AET has no influence. It was found previously that for such phages with single-stranded DNA, the lethal efficiency of 32P decay is unity, and that the lethal event is a DNA single-strand break, owing to the high energy of the nucleogenic 32S atom. As the recoil energy of the 33S atom is too low to account for such a break, it is suggested that the reorganization of the phosphate molecule into sulphate is able to bring about a DNA single-strand break with an efficiency as high as 0.7, at 0 degrees C. A model for the DNA double-strand-break produced by a transmutation processes is suggested.

Enhanced Locomotion Efficiency of a Bio-inspired Walking Robot using Contact Surfaces with Frictional Anisotropy

NASA Astrophysics Data System (ADS)

Manoonpong, Poramate; Petersen, Dennis; Kovalev, Alexander; Wörgötter, Florentin; Gorb, Stanislav N.; Spinner, Marlene; Heepe, Lars

2016-12-01

Based on the principles of morphological computation, we propose a novel approach that exploits the interaction between a passive anisotropic scale-like material (e.g., shark skin) and a non-smooth substrate to enhance locomotion efficiency of a robot walking on inclines. Real robot experiments show that passive tribologically-enhanced surfaces of the robot belly or foot allow the robot to grip on specific surfaces and move effectively with reduced energy consumption. Supplementing the robot experiments, we investigated tribological properties of the shark skin as well as its mechanical stability. It shows high frictional anisotropy due to an array of sloped denticles. The orientation of the denticles to the underlying collagenous material also strongly influences their mechanical interlocking with the substrate. This study not only opens up a new way of achieving energy-efficient legged robot locomotion but also provides a better understanding of the functionalities and mechanical properties of anisotropic surfaces. That understanding will assist developing new types of material for other real-world applications.

Enhanced Locomotion Efficiency of a Bio-inspired Walking Robot using Contact Surfaces with Frictional Anisotropy

PubMed Central

Manoonpong, Poramate; Petersen, Dennis; Kovalev, Alexander; Wörgötter, Florentin; Gorb, Stanislav N.; Spinner, Marlene; Heepe, Lars

2016-01-01

Based on the principles of morphological computation, we propose a novel approach that exploits the interaction between a passive anisotropic scale-like material (e.g., shark skin) and a non-smooth substrate to enhance locomotion efficiency of a robot walking on inclines. Real robot experiments show that passive tribologically-enhanced surfaces of the robot belly or foot allow the robot to grip on specific surfaces and move effectively with reduced energy consumption. Supplementing the robot experiments, we investigated tribological properties of the shark skin as well as its mechanical stability. It shows high frictional anisotropy due to an array of sloped denticles. The orientation of the denticles to the underlying collagenous material also strongly influences their mechanical interlocking with the substrate. This study not only opens up a new way of achieving energy-efficient legged robot locomotion but also provides a better understanding of the functionalities and mechanical properties of anisotropic surfaces. That understanding will assist developing new types of material for other real-world applications. PMID:28008936

Coupled Neutron Transport for HZETRN

NASA Technical Reports Server (NTRS)

Slaba, Tony C.; Blattnig, Steve R.

2009-01-01

Exposure estimates inside space vehicles, surface habitats, and high altitude aircrafts exposed to space radiation are highly influenced by secondary neutron production. The deterministic transport code HZETRN has been identified as a reliable and efficient tool for such studies, but improvements to the underlying transport models and numerical methods are still necessary. In this paper, the forward-backward (FB) and directionally coupled forward-backward (DC) neutron transport models are derived, numerical methods for the FB model are reviewed, and a computationally efficient numerical solution is presented for the DC model. Both models are compared to the Monte Carlo codes HETC-HEDS, FLUKA, and MCNPX, and the DC model is shown to agree closely with the Monte Carlo results. Finally, it is found in the development of either model that the decoupling of low energy neutrons from the light particle transport procedure adversely affects low energy light ion fluence spectra and exposure quantities. A first order correction is presented to resolve the problem, and it is shown to be both accurate and efficient.

Foam flow and liquid films motion: role of the surfactants properties

NASA Astrophysics Data System (ADS)

Cantat, Isabelle

2011-11-01

Liquid foams absorb energy in a much more efficient way than each of its constituents, taken separately. However, the local process at the origin of the energy dissipation is not entirely elucidated yet, and several models may apply, thus making worth local studies on simpler systems. We investigate the motion through a wet tube of transverse soap films, or lamellae, combining local thickness and velocity measurements in the wetting film. For foaming solution with a high dilatational surface modulus, we reveal a zone of several centimeters in length, the dynamic wetting film, which is significantly influenced by a moving lamella. The dependence of this influence length on lamella velocity and wetting film thickness provides an accurate discrimination among several possible surfactants models. In collaboration with B. Dollet.

The Nasal Geometry of the Reindeer Gives Energy-Efficient Respiration

NASA Astrophysics Data System (ADS)

Magnanelli, Elisa; Wilhelmsen, Øivind; Acquarone, Mario; Folkow, Lars P.; Kjelstrup, Signe

2017-01-01

Reindeer in the arctic region live under very harsh conditions and may face temperatures below 233 K. Therefore, efficient conservation of body heat and water is important for their survival. Alongside their insulating fur, the reindeer nasal mechanism for heat and mass exchange during respiration plays a fundamental role. We present a dynamic model to describe the heat and mass transport that takes place inside the reindeer nose, where we account for the complicated geometrical structure of the subsystems that are part of the nose. The model correctly captures the trend in experimental data for the temperature, heat and water recovery in the reindeer nose during respiration. As a reference case, we model a nose with a simple cylindrical-like geometry, where the total volume and contact area are the same as those determined in the reindeer nose. A comparison of the reindeer nose with the reference case shows that the nose geometry has a large influence on the velocity, temperature and water content of the air inside the nose. For all investigated cases, we find that the total entropy production during a breathing cycle is lower for the reindeer nose than for the reference case. The same trend is observed for the total energy consumption. The reduction in the total entropy production caused by the complicated geometry is higher (up to -20 %) at more extreme ambient conditions, when energy efficiency is presumably more important for the maintenance of energy balance in the animal. In the literature, a hypothesis has been proposed, which states that the most energy-efficient design of a system is characterized by equipartition of the entropy production. In agreement with this hypothesis, we find that the local entropy production during a breathing cycle is significantly more uniform for the reindeer nose than for the reference case. This suggests that natural selection has favored designs that give uniform entropy production when energy efficiency is an issue. Animals living in the harsh arctic climate, such as the reindeer, can therefore serve as inspiration for a novel industrial design with increased efficiency.

Energy conservation and efficiency in manufacturing: Employee decisions and actions

NASA Astrophysics Data System (ADS)

Corson, Marla D.

Energy conservation and intensity reduction efforts are becoming increasingly more prevalent and ultimately necessary, especially for energy-intensive manufacturing companies in particular to stay in business. Typical actions are to change technology, and thus, realize an energy cost savings in overall utilities. However, in today's competitive market, with climate change and other environmental impacts as well, it is necessary for the cost of energy to be valued as a cost of making a product, and thus, managed at the same level as the cost of labor or materials. This research assessed human behavior at the individual and organizational levels both at work and at home that either prompted or prohibited employees from taking daily action to conserve energy or develop greater energy efficient practices. Ultimately, the questions began with questions regarding employee views and knowledge of energy at work and at home and what drives both behaviors toward conservation or efficiency. And, the contribution identifies the key drivers, barriers, and/or incentives that affect those behaviors. The results of this study show that the key driver and motivator for energy conservation both at home and work is cost savings. The study showed that to further motivate individuals to conserve energy at home and work, more knowledge of the impact their actions have or could have as well as tools would be needed. The most poinient aspect of the research was the level of importance placed on energy conservation and the desire to conserve. The feedback given to the open ended questions was quite impressive regarding what employees have done and continue to do particularly within their homes to conserve energy. These findings brought about final recommendations that were in fact not expected but could significantly influence an increase in energy conservation at work by leveraging the existing desire to conserve which is a key component to decision making.

Influence of oxygen on the chemical stage of radiobiological mechanism

NASA Astrophysics Data System (ADS)

Barilla, Jiří; Lokajíček, Miloš V.; Pisaková, Hana; Simr, Pavel

2016-07-01

The simulation of the chemical stage of radiobiological mechanism may be very helpful in studying the radiobiological effect of ionizing radiation when the water radical clusters formed by the densely ionizing ends of primary or secondary charged particle may form DSBs damaging DNA molecules in living cells. It is possible to study not only the efficiency of individual radicals but also the influence of other species or radiomodifiers (mainly oxygen) being present in water medium during irradiation. The mathematical model based on Continuous Petri nets (proposed by us recently) will be described. It makes it possible to analyze two main processes running at the same time: chemical radical reactions and the diffusion of radical clusters formed during energy transfer. One may study the time change of radical concentrations due to the chemical reactions running during diffusion process. Some orientation results concerning the efficiency of individual radicals in DSB formation (in the case of Co60 radiation) will be presented; the influence of oxygen present in water medium during irradiation will be shown, too.

Division of Energy Biosciences annual report and summaries of FY 1996 activities

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-04-01

The mission of the Division of Energy Biosciences is to support research that advances the fundamental knowledge necessary for the future development of biotechnologies related to the Department of Energy`s mission. The departmental civilian objectives include effective and efficient energy production, energy conservation, environmental restoration, and waste management. The Energy Biosciences program emphasizes research in the microbiological and plant sciences, as these understudied areas offer numerous scientific opportunities to dramatically influence environmentally sensible energy production and conservation. The research supported is focused on the basic mechanism affecting plant productivity, conversion of biomass and other organic materials into fuels and chemicalsmore » by microbial systems, and the ability of biological systems to replace energy-intensive or pollutant-producing processes. The Division also addresses the increasing number of new opportunities arising at the interface of biology with other basic energy-related sciences such as biosynthesis of novel materials and the influence of soil organisms on geological processes. This report gives summaries on 225 projects on photosynthesis, membrane or ion transport, plant metabolism and biosynthesis, carbohydrate metabolism lipid metabolism, plant growth and development, plant genetic regulation and genetic mechanisms, plant cell wall development, lignin-polysaccharide breakdown, nitrogen fixation and plant-microbial symbiosis, mechanism for plant adaptation, fermentative microbial metabolism, one and two carbon microbial metabolism, extremophilic microbes, microbial respiration, nutrition and metal metabolism, and materials biosynthesis.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamashita, G.; Nagai, M., E-mail: mnagai@mp.es.osaka-u.ac.jp, E-mail: ashida@mp.es.osaka-u.ac.jp; Ashida, M., E-mail: mnagai@mp.es.osaka-u.ac.jp, E-mail: ashida@mp.es.osaka-u.ac.jp

We estimated the carrier multiplication efficiency in the most common solar-cell material, Si, by using optical-pump/terahertz-probe spectroscopy. Through close analysis of time-resolved data, we extracted the exact number of photoexcited carriers from the sheet carrier density 10 ps after photoexcitation, excluding the influences of spatial diffusion and surface recombination in the time domain. For incident photon energies greater than 4.0 eV, we observed enhanced internal quantum efficiency due to carrier multiplication. The evaluated value of internal quantum efficiency agrees well with the results of photocurrent measurements. This optical method allows us to estimate the carrier multiplication and surface recombination of carriersmore » quantitatively, which are crucial for the design of the solar cells.« less

Power maximization of a point absorber wave energy converter using improved model predictive control

NASA Astrophysics Data System (ADS)

Milani, Farideh; Moghaddam, Reihaneh Kardehi

2017-08-01

This paper considers controlling and maximizing the absorbed power of wave energy converters for irregular waves. With respect to physical constraints of the system, a model predictive control is applied. Irregular waves' behavior is predicted by Kalman filter method. Owing to the great influence of controller parameters on the absorbed power, these parameters are optimized by imperialist competitive algorithm. The results illustrate the method's efficiency in maximizing the extracted power in the presence of unknown excitation force which should be predicted by Kalman filter.

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The report is an overview of electric energy efficiency programs. It takes a concise look at what states are doing to encourage energy efficiency and how it impacts electric utilities. Energy efficiency programs began to be offered by utilities as a response to the energy crises of the 1970s. These regulatory-driven programs peaked in the early-1990s and then tapered off as deregulation took hold. Today, rising electricity prices, environmental concerns, and national security issues have renewed interest in increasing energy efficiency as an alternative to additional supply. In response, new methods for administering, managing, and delivering energy efficiency programs aremore » being implemented. Topics covered in the report include: Analysis of the benefits of energy efficiency and key methods for achieving energy efficiency; evaluation of the business drivers spurring increased energy efficiency; Discussion of the major barriers to expanding energy efficiency programs; evaluation of the economic impacts of energy efficiency; discussion of the history of electric utility energy efficiency efforts; analysis of the impact of energy efficiency on utility profits and methods for protecting profitability; Discussion of non-utility management of energy efficiency programs; evaluation of major methods to spur energy efficiency - systems benefit charges, resource planning, and resource standards; and, analysis of the alternatives for encouraging customer participation in energy efficiency programs.« less

Post-recombination early Universe cooling by translation-internal inter-conversion: The role of minor constituents.

PubMed

McCaffery, Anthony J

2015-09-14

Little is known of the mechanism by which H and H2, the principal constituents of the post-re-combination early Universe, cooled sufficiently to permit cluster formation, nucleosynthesis, and, eventually, the formation of structured objects. Radiative decay primarily cools the internal modes of H2, as Δj = - 2 jumps accompany quadrupolar emission. This, however, would be a self-limiting mechanism. In this work, a translational energy cooling mechanism based on collision-induced, translation-to-internal mode conversion, is extended, following an earlier study [A. J. McCaffery and R. J. Marsh, J. Chem. Phys. 139, 234310 (2013)] of ensembles comprising H2 in a H atom bath gas. Here, the possible influence of minor species, such as HD, on this cooling mechanism is investigated. Results suggest that the influence of HD is small but not insignificant. Conversion is very rapid and an overall translation-to-internal energy conversion efficiency of some 5% could be expected. This finding may be of use in the further development of models of this complex phase of early Universe evolution. An unexpected finding in this study was that H2 + HD ensembles are capable of very rapid translation-to-internal conversion with efficiencies of >40% and relaxation rates that appear to be relatively slow. This may have potential as an energy storage mechanism.

Post-recombination early Universe cooling by translation–internal inter-conversion: The role of minor constituents

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCaffery, Anthony J., E-mail: A.J.McCaffery@sussex.ac.uk

Little is known of the mechanism by which H and H{sub 2}, the principal constituents of the post-re-combination early Universe, cooled sufficiently to permit cluster formation, nucleosynthesis, and, eventually, the formation of structured objects. Radiative decay primarily cools the internal modes of H{sub 2}, as Δj = − 2 jumps accompany quadrupolar emission. This, however, would be a self-limiting mechanism. In this work, a translational energy cooling mechanism based on collision-induced, translation-to-internal mode conversion, is extended, following an earlier study [A. J. McCaffery and R. J. Marsh, J. Chem. Phys. 139, 234310 (2013)] of ensembles comprising H{sub 2} in amore » H atom bath gas. Here, the possible influence of minor species, such as HD, on this cooling mechanism is investigated. Results suggest that the influence of HD is small but not insignificant. Conversion is very rapid and an overall translation-to-internal energy conversion efficiency of some 5% could be expected. This finding may be of use in the further development of models of this complex phase of early Universe evolution. An unexpected finding in this study was that H{sub 2} + HD ensembles are capable of very rapid translation-to-internal conversion with efficiencies of >40% and relaxation rates that appear to be relatively slow. This may have potential as an energy storage mechanism.« less

Evaluation of a pilot-scale sewage biogas powered 2.8 kWe Solid Oxide Fuel Cell: Assessment of heat-to-power ratio and influence of oxygen content

NASA Astrophysics Data System (ADS)

de Arespacochaga, N.; Valderrama, C.; Peregrina, C.; Mesa, C.; Bouchy, L.; Cortina, J. L.

2015-12-01

Biogas from anaerobic digestion of organic matter is a promising renewable energy source and fuel cells appear as a breakthrough technology to improve the performance of the biogas-to-energy valorisation chain. The vast majority of studies addressing biogas energy recovery through Solid Oxide Fuel Cells published in recent years correspond to simulations and lab-scale performance with synthetic biogas. This paper assesses the pilot performance of a 2.8 kWe SOFC unit powered with cleaned sewage biogas for around 700 h in a Wastewater Treatment Plant. The biogas thorough treatment consisting of a biological desulphurisation with a biotrickling filter followed by a deep cleaning step based on adsorption is successful for removing sulphur compounds, siloxanes and hydrocarbons. The influence of the heat-to-power ratio on fuel cell performance is investigated operating the system at O/C ratio of 2, reforming temperature of 550 °C, stack temperature of 800 °C and at a constant voltage of 43 V. At optimized conditions for electrical production satisfying heat demand in the WWTP, system electrical and thermal efficiencies account for 34% and 28%. Cogeneration efficiency remains constant at around 59-62% for all the heat-to-power ratios tested. Furthermore, the impact of the oxygen content in the biogas is also studied.

Energy-efficient pulse-coupled synchronization strategy design for wireless sensor networks through reduced idle listening

PubMed Central

Wang, Yongqiang; Núñez, Felipe; Doyle, Francis J.

2013-01-01

Synchronization is crucial to wireless sensor networks due to their decentralized structure. We propose an energy-efficient pulse-coupled synchronization strategy to achieve this goal. The basic idea is to reduce idle listening by intentionally introducing a large refractory period in the sensors’ cooperation. The large refractory period greatly reduces idle listening in each oscillation period, and is analytically proven to have no influence on the time to synchronization. Hence, it significantly reduces the total energy consumption in a synchronization process. A topology control approach tailored for pulse-coupled synchronization is given to guarantee a k-edge strongly connected interaction topology, which is tolerant to communication-link failures. The topology control approach is totally decentralized and needs no information exchange among sensors, and it is applicable to dynamic network topologies as well. This facilitates a completely decentralized implementation of the synchronization strategy. The strategy is applicable to mobile sensor networks, too. QualNet case studies confirm the effectiveness of the synchronization strategy. PMID:24307831

The energetics of fish growth and how it constrains food-web trophic structure.

PubMed

Barneche, Diego R; Allen, Andrew P

2018-06-01

The allocation of metabolic energy to growth fundamentally influences all levels of biological organisation. Here we use a first-principles theoretical model to characterise the energetics of fish growth at distinct ontogenetic stages and in distinct thermal regimes. Empirically, we show that the mass scaling of growth rates follows that of metabolic rate, and is somewhat steeper at earlier ontogenetic stages. We also demonstrate that the cost of growth, E m , varies substantially among fishes, and that it may increase with temperature, trophic level and level of activity. Theoretically, we show that E m is a primary determinant of the efficiency of energy transfer across trophic levels, and that energy is transferred more efficiently between trophic levels if the prey are young and sedentary. Overall, our study demonstrates the importance of characterising the energetics of individual growth in order to understand constraints on the structure of food webs and ecosystems. © 2018 John Wiley & Sons Ltd/CNRS.

Birth weight predicted baseline muscular efficiency, but not response of energy expenditure to calorie restriction: An empirical test of the predictive adaptive response hypothesis.

PubMed

Workman, Megan; Baker, Jack; Lancaster, Jane B; Mermier, Christine; Alcock, Joe

2016-07-01

Aiming to test the evolutionary significance of relationships linking prenatal growth conditions to adult phenotypes, this study examined whether birth size predicts energetic savings during fasting. We specifically tested a Predictive Adaptive Response (PAR) model that predicts greater energetic saving among adults who were born small. Data were collected from a convenience sample of young adults living in Albuquerque, NM (n = 34). Indirect calorimetry quantified changes in resting energy expenditure (REE) and active muscular efficiency that occurred in response to a 29-h fast. Multiple regression analyses linked birth weight to baseline and postfast metabolic values while controlling for appropriate confounders (e.g., sex, body mass). Birth weight did not moderate the relationship between body size and energy expenditure, nor did it predict the magnitude change in REE or muscular efficiency observed from baseline to after fasting. Alternative indicators of birth size were also examined (e.g., low v. normal birth weight, comparison of tertiles), with no effects found. However, baseline muscular efficiency improved by 1.1% per 725 g (S.D.) increase in birth weight (P = 0.037). Birth size did not influence the sensitivity of metabolic demands to fasting-neither at rest nor during activity. Moreover, small birth size predicted a reduction in the efficiency with which muscles convert energy expended into work accomplished. These results do not support the ascription of adaptive function to phenotypes associated with small birth size. © 2015 Wiley Periodicals, Inc. Am. J. Hum. Biol. 28:484-492, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

A model study of assisted adiabatic transfer of population in the presence of collisional dephasing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masuda, Shumpei, E-mail: shumpei.masuda@aalto.fi; Rice, Stuart A., E-mail: s-rice@uchicago.edu

2015-06-28

Previous studies have demonstrated that when experimental conditions generate non-adiabatic dynamics that prevents highly efficient population transfer between states of an isolated system by stimulated Raman adiabatic passage (STIRAP), the addition of an auxiliary counter-diabatic field (CDF) can restore most or all of that efficiency. This paper examines whether that strategy is also successful in a non-isolated system in which the energies of the states fluctuate, e.g., when a solute is subject to collisions with solvent. We study population transfer in two model systems: (i) the three-state system used by Demirplak and Rice [J. Chem. Phys. 116, 8028 (2002)] andmore » (ii) a four-state system, derived from the simulation studies of Demirplak and Rice [J. Chem. Phys. 125, 194517 (2006)], that mimics HCl in liquid Ar. Simulation studies of the vibrational manifold of HCl in dense fluid Ar show that the collision induced vibrational energy level fluctuations have asymmetric distributions. Representations of these asymmetric energy level fluctuation distributions are used in both models (i) and (ii). We identify three sources of degradation of the efficiency of STIRAP generated selective population transfer in model (ii): too small pulse areas of the laser fields, unwanted interference arising from use of strong fields, and the vibrational detuning. For both models (i) and (ii), our examination of the efficiency of STIRAP + CDF population transfer under the influence of the asymmetric distribution of the vibrational energy fluctuations shows that there is a range of field strengths and pulse durations under which STIRAP + CDF control of population transfer has greater efficiency than does STIRAP generated population transfer.« less

Impact of Groundwater Flow and Energy Load on Multiple Borehole Heat Exchangers.

PubMed

Dehkordi, S Emad; Schincariol, Robert A; Olofsson, Bo

2015-01-01

The effect of array configuration, that is, number, layout, and spacing, on the performance of multiple borehole heat exchangers (BHEs) is generally known under the assumption of fully conductive transport. The effect of groundwater flow on BHE performance is also well established, but most commonly for single BHEs. In multiple-BHE systems the effect of groundwater advection can be more complicated due to the induced thermal interference between the boreholes. To ascertain the influence of groundwater flow and borehole arrangement, this study investigates single- and multi-BHE systems of various configurations. Moreover, the influence of energy load balance is also examined. The results from corresponding cases with and without groundwater flow as well as balanced and unbalanced energy loads are cross-compared. The groundwater flux value, 10(-7) m/s, is chosen based on the findings of previous studies on groundwater flow interaction with BHEs and thermal response tests. It is observed that multi-BHE systems with balanced loads are less sensitive to array configuration attributes and groundwater flow, in the long-term. Conversely, multi-BHE systems with unbalanced loads are influenced by borehole array configuration as well as groundwater flow; these effects become more pronounced with time, unlike when the load is balanced. Groundwater flow has more influence on stabilizing loop temperatures, compared to array characteristics. Although borehole thermal energy storage (BTES) systems have a balanced energy load function, preliminary investigation on their efficiency shows a negative impact by groundwater which is due to their dependency on high temperature gradients between the boreholes and surroundings. © 2014, National Ground Water Association.

Energy Pooling Upconversion in Free Space and Optical Cavities

NASA Astrophysics Data System (ADS)

LaCount, Michael D.

The ability to efficiently convert the wavelength of light has value in a wide range of disciplines that include the fields of photovoltaics, plant growth, optics and medicine. The processes by which such transformations are carried out are known as upconversions and downconversions. There are several ways to up/down convert light, each with its own attributes, issues, and competing mechanisms. Most are associated with one-body or two-body processes. Three-body dynamics are also possible though, going by the names of quantum cutting (downconversion) and energy pooling (upconversion). These use virtual excited electronic states to mediate conversions as has been experimentally realized using lanthanide ions embedded in wide bandgap materials. The use of lanthanides to convert light is not ideal due to their relative scarcity, toxicity, and the limited range of light frequencies that can be absorbed and emitted. Organic molecules, on the other hand, are typically non-toxic, are made up of abundant elements, and can be designed with tailored spectral properties. At issue is whether or not they can be used to carry out efficient energy pooling, the central question to be answered in this thesis. The research presented here draws on a perturbative quantum electrodynamics framework previously established for generic energy pooling. It was used to develop a computational methodology for determining the rate of energy pooling and its competing processes. This, in turn, draws on a combination of time-dependent density functional theory, quantum electrodynamics, and perturbation theory to generate the requisite material property data. This computational model was applied to two test systems consisting of stilbene-fluorescein and hexabenzocoronene-oligothiophene. The stilbene-fluorescein system was found to have a maximum energy pooling rate efficiency (as compared to competing processes) of 17% and the hexabenzocoronene-oligothiophene system was found to have a maximum energy pooling rate efficiency of 99%. This demonstrates that the energy pooling rate can be made faster than its competing processes. Based on the results of this study, a set of design rules was developed to optimize the rate efficiency of energy pooling. Prior to this research, no attempt had been made to determine if energy pooling could be made to out-pace competing processes--i.e. whether or not a molecular system could be designed to utilize energy pooling as an efficient means of upconversion. This initial investigation was part of a larger effort involving a team of researchers at the University of Colorado, Boulder and at the National Renewable Energy Laboratory. After establishing our computational proof-of-concept, we collectively used the new design rules to select an improved system for energy pooling. This consisted of rhodamine 6G and stilbene-420. These molecules were fabricated into a thin film, and the maximum internal quantum yield was measured to be 36% under sufficiently high intensity light. To further increase the efficiency of energy pooling, encapsulation within optical cavities was considered as a way of changing the rate of processes characterized by electric dipole-dipole coupling. This was carried out using a combination of classical electromagnetism, quantum electrodynamics, and perturbation theory. It was found that, in the near field, if the distance of the energy transfer is smaller than the distance from the energy transfer site and the cavity wall, then the electric dipole-dipole coupling tensor is not influenced by the cavity environment and the rates of energy transfer processes are the same as those in free space. Any increase in energy transfer efficiencies that are experimentally measured must therefore be caused by changing the rate of light absorption and emission. This is an important finding because earlier, less rigorous studies had concluded otherwise. It has been previously demonstrated that an optical cavity can be used to inhibit the spontaneous emission of atoms or molecules placed within it. This too was examined as a possible means of increasing energy pooling efficiency. Using first-principles methods, quantum electrodynamics, perturbation theory, and a kinetic model, the efficiency of energy pooling upconversion within a tuned rectangular cavity was found to be significantly larger than in free space. A model system with a free-space energy pooling upconversion efficiency of 23% was found to increase to 47% when placed in a tuned rectangular cavity.

Neuromodulation and Synaptic Plasticity for the Control of Fast Periodic Movement: Energy Efficiency in Coupled Compliant Joints via PCA.

PubMed

Stratmann, Philipp; Lakatos, Dominic; Albu-Schäffer, Alin

2016-01-01

There are multiple indications that the nervous system of animals tunes muscle output to exploit natural dynamics of the elastic locomotor system and the environment. This is an advantageous strategy especially in fast periodic movements, since the elastic elements store energy and increase energy efficiency and movement speed. Experimental evidence suggests that coordination among joints involves proprioceptive input and neuromodulatory influence originating in the brain stem. However, the neural strategies underlying the coordination of fast periodic movements remain poorly understood. Based on robotics control theory, we suggest that the nervous system implements a mechanism to accomplish coordination between joints by a linear coordinate transformation from the multi-dimensional space representing proprioceptive input at the joint level into a one-dimensional controller space. In this one-dimensional subspace, the movements of a whole limb can be driven by a single oscillating unit as simple as a reflex interneuron. The output of the oscillating unit is transformed back to joint space via the same transformation. The transformation weights correspond to the dominant principal component of the movement. In this study, we propose a biologically plausible neural network to exemplify that the central nervous system (CNS) may encode our controller design. Using theoretical considerations and computer simulations, we demonstrate that spike-timing-dependent plasticity (STDP) for the input mapping and serotonergic neuromodulation for the output mapping can extract the dominant principal component of sensory signals. Our simulations show that our network can reliably control mechanical systems of different complexity and increase the energy efficiency of ongoing cyclic movements. The proposed network is simple and consistent with previous biologic experiments. Thus, our controller could serve as a candidate to describe the neural control of fast, energy-efficient, periodic movements involving multiple coupled joints.

Neuromodulation and Synaptic Plasticity for the Control of Fast Periodic Movement: Energy Efficiency in Coupled Compliant Joints via PCA

PubMed Central

Stratmann, Philipp; Lakatos, Dominic; Albu-Schäffer, Alin

2016-01-01

There are multiple indications that the nervous system of animals tunes muscle output to exploit natural dynamics of the elastic locomotor system and the environment. This is an advantageous strategy especially in fast periodic movements, since the elastic elements store energy and increase energy efficiency and movement speed. Experimental evidence suggests that coordination among joints involves proprioceptive input and neuromodulatory influence originating in the brain stem. However, the neural strategies underlying the coordination of fast periodic movements remain poorly understood. Based on robotics control theory, we suggest that the nervous system implements a mechanism to accomplish coordination between joints by a linear coordinate transformation from the multi-dimensional space representing proprioceptive input at the joint level into a one-dimensional controller space. In this one-dimensional subspace, the movements of a whole limb can be driven by a single oscillating unit as simple as a reflex interneuron. The output of the oscillating unit is transformed back to joint space via the same transformation. The transformation weights correspond to the dominant principal component of the movement. In this study, we propose a biologically plausible neural network to exemplify that the central nervous system (CNS) may encode our controller design. Using theoretical considerations and computer simulations, we demonstrate that spike-timing-dependent plasticity (STDP) for the input mapping and serotonergic neuromodulation for the output mapping can extract the dominant principal component of sensory signals. Our simulations show that our network can reliably control mechanical systems of different complexity and increase the energy efficiency of ongoing cyclic movements. The proposed network is simple and consistent with previous biologic experiments. Thus, our controller could serve as a candidate to describe the neural control of fast, energy-efficient, periodic movements involving multiple coupled joints. PMID:27014051

A comprehensive framework to assess, model, and enhance the human role in conserving energy in commercial buildings

NASA Astrophysics Data System (ADS)

Azar, Elie

Energy conservation and sustainability are subjects of great interest today, especially in the commercial building sector which is witnessing a very high and growing demand for energy. Traditionally, efforts to reduce energy consumption in this sector consisted of researching and developing energy efficient building technologies and systems. On the other hand, recent studies indicate that human actions are major determinants of building energy performance and can lead to excessive energy use even in advanced low-energy buildings. As a result, it is essential to determine if the approach to future energy reduction initiatives should remain solely technology-focused, or if a human-focused approach is also needed to complement advancements in technology and improve building operation and performance. In practice, while technology-focused solutions have been extensively researched, promoted, and adopted in commercial buildings, research efforts on the role of human actions and energy use behaviors in energy conservation remain very limited. This study fills the missing gap in literature by presenting a comprehensive framework to (1) understand and quantify the influence of human actions on building energy performance, (2) model building occupants' energy use behaviors and account for potential changes in these behaviors over time, and (3) test and optimize different human-focused energy reduction interventions to increase their adoption in commercial buildings. Results are significant and prove that human actions have a major role to play in reducing the energy intensity of the commercial building sector. This sheds the light on the need for a shift in how people currently use and control different buildings systems, as this is crucial to ensure efficient building operation and to maximize the return on investment in energy-efficient technologies. Furthermore, this study proposes methods and tools that can be applied on any individual or groups of commercial buildings to evaluate the human impact on their energy performance. This is expected to boost research on the topic and promote the integration of human-focused interventions in large-scale energy reduction initiatives and policies. Finally, this dissertation presents a roadmap for the future challenges to energy conservation and the steps to take towards a more sustainable building sector and society.

The influence of the waterjet propulsion system on the ships' energy consumption and emissions inventories.

PubMed

Durán-Grados, Vanesa; Mejías, Javier; Musina, Liliya; Moreno-Gutiérrez, Juan

2018-08-01

In this study we consider the problems associated with calculating ships' energy and emission inventories. Various related uncertainties are described in many similar studies published in the last decade, and applying to Europe, the USA and Canada. However, none of them have taken into account the performance of ships' propulsion systems. On the one hand, when a ship uses its propellers, there is no unanimous agreement on the equations used to calculate the main engines load factor and, on the other, the performance of waterjet propulsion systems (for which this variable depends on the speed of the ship) has not been taken into account in any previous studies. This paper proposes that the efficiency of the propulsion system should be included as a new parameter in the equation that defines the actual power delivered by a ship's main engines, as applied to calculate energy consumption and emissions in maritime transport. To highlight the influence of the propulsion system on calculated energy consumption and emissions, the bottom-up method has been applied using data from eight fast ferries operating across the Strait of Gibraltar over the course of one year. This study shows that the uncertainty about the efficiency of the propulsion system should be added as one more uncertainty in the energy and emission inventories for maritime transport as currently prepared. After comparing four methods for this calculation, the authors propose a new method for eight cases. For the calculation of the Main Engine's fuel oil consumption, differences up to 22% between some methods were obtained at low loads. Copyright © 2018 Elsevier B.V. All rights reserved.

Experimental and Computational Mechanistic Studies Guiding the Rational Design of Molecular Electrocatalysts for Production and Oxidation of Hydrogen.

PubMed

Raugei, Simone; Helm, Monte L; Hammes-Schiffer, Sharon; Appel, Aaron M; O'Hagan, Molly; Wiedner, Eric S; Bullock, R Morris

2016-01-19

Understanding how to control the movement of protons and electrons is crucial to the design of fast, efficient electrocatalysts for H2 production and oxidation based on earth-abundant metals. Our work seeks to address fundamental questions about proton movement. We have demonstrated that incorporating a pendant amine functioning as a proton relay in the second coordination sphere of a metal complex helps proton mobility, resulting in faster and more energy-efficient catalysts. Proton-transfer reactions can be rate-limiting and are influenced by several factors, such as pKa values, steric effects, hydrogen bonding, and solvation/desolvation of the exogenous base and acid employed. The presence of multiple protonation sites introduces branching points along the catalytic cycle, making less productive pathways accessible or leading to the formation of stable off-cycle species. Using ligands with only one pendant amine mitigates this problem and results in catalysts with high rates for production of H2, although generally at higher overpotentials. For H2 oxidation catalysts, iron complexes with a high H2 binding affinity were developed. However, these iron complexes had a pKa mismatch between the protonated metal center and the protonated pendant amine, and consequently intramolecular proton movement was slow. Taken altogether, our results demonstrate the necessity of optimizing the entire catalytic cycle because optimization of a specific catalytic step can negatively influence another step and not necessarily lead to a better catalytic performance. We discuss a general procedure, based on thermodynamic arguments, which allows the simultaneous minimization of the free-energy change of each catalytic step, yielding a nearly flat free-energy surface, with no large barriers due to energy mismatches from either high- or low-energy intermediates.

Acoustic measurement of sediment dynamics in the coastal zones using wireless sensor networks

NASA Astrophysics Data System (ADS)

Sudhakaran, A., II; Paramasivam, A.; Seshachalam, S.; A, C.

2014-12-01

Analyzing of the impact of constructive or low energy waves and deconstructive or high energy waves in the ocean are very much significant since they deform the geometry of seashore. The deformation may lead to productive result and also to the end of deteriorate damage. Constructive waves results deposition of sediment which widens the beach where as deconstructive waves results erosion which narrows the beach. Validation of historic sediment transportation and prediction of the direction of movement of seashore is essential to prevent unrecoverable damages by incorporating precautionary measurements to identify the factors that influence sediment transportation if feasible. The objective of this study is to propose a more reliable and energy efficient Information and communication system to model the Coastal Sediment Dynamics. Various factors influencing the sediment drift at a particular region is identified. Consequence of source depth and frequency dependencies of spread pattern in the presence of sediments is modeled. Property of source depth and frequency on sensitivity to values of model parameters are determined. Fundamental physical reasons for these sediment interaction effects are given. Shallow to deep water and internal and external wave model of ocean is obtained intended to get acoustic data assimilation (ADA). Signal processing algorithms are used over the observed data to form a full field acoustic propagation model and construct sound speed profile (SSP). The inversions of data due to uncertainties at various depths are compared. The impact of sediment drift over acoustic data is identified. An energy efficient multipath routing scheme Wireless sensor networks (WSN) is deployed for the well-organized communication of data. The WSN is designed considering increased life time, decreased power consumption, free of threats and attacks. The practical data obtained from the efficient system to model the ocean sediment dynamics are evaluated with remote sensing data and the reasons of deviations and uncertainties are unbiased. The probability of changes and impact of sediment drift over ocean dynamic model over the long running of years is estimated.

Inlet Diameter and Flow Volume Effects on Separation and Energy Efficiency of Hydrocyclones

NASA Astrophysics Data System (ADS)

Erikli, Ş.; Olcay, A. B.

2015-08-01

This study investigates hydrocyclone performance of an oil injected screw compressor. Especially, the oil separation efficiency of a screw compressor plays a significant role for air quality and non-stop working hour of compressors has become an important issue when the efficiency in energy is considered. In this study, two separation efficiency parameters were selected to be hydrocyclone inlet diameter and flow volume height between oil reservoir surface and top of the hydrocyclone. Nine different cases were studied in which cyclone inlet diameter and flow volume height between oil reservoir surface and top were investigated in regards to separation and energy performance aspects and the effect of the parameters on the general performance appears to be causing powerful influence. Flow inside the hydrocyclone geometry was modelled by Reynolds Stress Model (RSM) and hydro particles were tracked by Discrete Phase Model (DPM). Besides, particle break up was modelled by the Taylor Analogy Breakup (TAB) model. The reversed vortex generation was observed at different planes. The upper limit of the inlet diameter of the cyclone yields the centrifugal force on particles to decrease while the flow becomes slower; and the larger diameter implies slower flow. On the contrary, the lower limit is increment in speed causes breakup problems that the particle diameters become smaller; consequently, it is harder to separate them from gas.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Razhev, A M; Kargapol'tsev, E S; Churkin, D S

Results of an experimental study of the influence of a gas mixture (laser active medium) composition on an output energy and total efficiency of gas-discharge excimer lasers on ArF* (193 nm), KrCl* (222 nm), KrF* (248 nm) and XeCl* (308 nm) molecules operating without a buffer gas are presented. The optimal ratios of gas components (from the viewpoint of a maximum output energy) of an active medium are found, which provide an efficient operation of laser sources. It is experimentally confirmed that for gas-discharge excimer lasers on halogenides of inert gases the presence of a buffer gas in an activemore » medium is not a necessary condition for efficient operation. For the first time, in two-component gas mixtures of repetitively pulsed gas-discharge excimer lasers on electron transitions of excimer molecules ArF*, KrCl*, KrF* and XeCl*, the pulsed energy of laser radiation obtained under pumping by a transverse volume electric discharge in a low-pressure gas mixture without a buffer gas reached up to 170 mJ and a high pulsed output power (of up to 24 MW) was obtained at a FWHM duration of the KrF-laser pulse of 7 ns. The maximal total efficiency obtained in the experiment with two-component gas mixtures of KrF and XeCl lasers was 0.8%. (lasers)« less

Response of evapotranspiration to changes in land use and land cover and climate in China during 2001–2013

Treesearch

Gen Li; Fangmin Zhang; Yuanshu Jing; Yibo Liu; Ge Sun

2017-01-01

Land surface evapotranspiration (ET) is a central component of the Earth's global energy balance and water cycle. Understanding ET is important in quantifying the impacts of human influences on the hydrological cycle and thus helps improving water use efficiency and strengthening water use planning and watershed management. China has experienced tremendous land...

Influence of laser irradiation on deposition characteristics of cold sprayed Stellite-6 coatings

NASA Astrophysics Data System (ADS)

Li, Bo; Jin, Yan; Yao, Jianhua; Li, Zhihong; Zhang, Qunli; Zhang, Xin

2018-03-01

Depositing hard materials such as Stellite-6 solely by cold spray (CS) is challengeable due to limited ability of plastic deformation. In this study, the deposition of Stellite-6 powder was achieved by supersonic laser deposition (SLD) which combines CS with synchronous laser irradiation. The surface morphology, deposition efficiency, track shape of Stellite-6 coatings produced over a range of laser irradiation temperatures were examined so as to reveal the effects of varying laser energy inputting on the deposition process of high strength material. The microstructure, phase composition and wear/corrosion resistant properties of the as-deposited Stellite-6 coatings were also investigated. The experimental results demonstrate that the surface flatness and deposition efficiency increase with laser irradiation temperature due to the softening effect induced by laser heating. The as-deposited Stellite-6 tracks show asymmetric shapes which are influenced by the relative configuration of powder stream and laser beam. The SLD coatings can preserve the original microstructure and phase of the feedstock material due to relatively low laser energy inputting, which result in the superior wear/corrosion resistant properties as compared to the counterpart prepared by laser cladding.

A high temperature drop-tube and packed-bed solar reactor for continuous biomass gasification

NASA Astrophysics Data System (ADS)

Bellouard, Quentin; Abanades, Stéphane; Rodat, Sylvain; Dupassieux, Nathalie

2017-06-01

Biomass gasification is an attractive process to produce high-value syngas. Utilization of concentrated solar energy as the heat source for driving reactions increases the energy conversion efficiency, saves biomass resource, and eliminates the needs for gas cleaning and separation. A high-temperature tubular solar reactor combining drop tube and packed bed concepts was used for continuous solar-driven gasification of biomass. This 1 kW reactor was experimentally tested with biomass feeding under real solar irradiation conditions at the focus of a 2 m-diameter parabolic solar concentrator. Experiments were conducted at temperatures ranging from 1000°C to 1400°C using wood composed of a mix of pine and spruce (bark included) as biomass feedstock. The aim of this study was to demonstrate the feasibility of syngas production in this reactor concept and to prove the reliability of continuous biomass gasification processing using solar energy. The study first consisted of a parametric study of the gasification conditions to obtain an optimal gas yield. The influence of temperature and oxidizing agent (H2O or CO2) on the product gas composition was investigated. The study then focused on solar gasification during continuous biomass particle injection for demonstrating the feasibility of a continuous process. Regarding the energy conversion efficiency of the lab scale reactor, energy upgrade factor of 1.21 and solar-to-fuel thermochemical efficiency up to 28% were achieved using wood heated up to 1400°C.

75 FR 34657 - Energy Efficiency and Sustainable Design Standards for New Federal Buildings

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-18

... Efficiency and Sustainable Design Standards for New Federal Buildings AGENCY: Office of Energy Efficiency and....S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Federal Energy Management... June 11, 2010. Cathy Zoi, Assistant Secretary, Energy Efficiency and Renewable Energy. [FR Doc. 2010...

48 CFR 23.203 - Energy-efficient products.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Energy-efficient products... SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 23.203 Energy-efficient...

48 CFR 23.203 - Energy-efficient products.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Energy-efficient products... SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 23.203 Energy-efficient...

48 CFR 23.203 - Energy-efficient products.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Energy-efficient products... SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 23.203 Energy-efficient...

48 CFR 23.203 - Energy-efficient products.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Energy-efficient products... SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 23.203 Energy-efficient...

48 CFR 23.203 - Energy-efficient products.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Energy-efficient products... SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 23.203 Energy-efficient...

Urban household energy use in Thailand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyler, S.R.

Changes in household fuel and electricity use that accompany urbanization in Third World countries bear large economic and environmental costs. The processes driving the fuel transition, and the policy mechanisms by which it can be influenced, need to be better understood for the sake of forecasting and planning, especially in the case of electricity demand. This study examines patterns of household fuel use and electrical appliance utilization in Bangkok, Chieng Mai and Ayutthaya, Thailand, based on the results of a household energy survey. Survey data are statistically analyzed using a variety of multiple regression techniques to evaluate the relative influencemore » of various household and fuel characteristics on fuel and appliance choice. Results suggest that changes to the value of women's time in urban households, as women become increasingly active in the labor force, have a major influence on patterns of household energy use. The use of the home for small-scale commercial activities, particularly food preparation, also has a significant influence on fuel choice. In general, household income does not prove to be an important factor in fuel and appliance selection in these cities, although income is closely related to total electricity use. The electricity use of individual household appliances is also analyzed using statistical techniques as well as limited direct metering. The technology of appliance production in Thailand is evaluated through interviews with manufacturers and comparisons of product performance. These data are used to develop policy recommendations for improving the efficiency of electrical appliances in Thailand by relying principally on the dynamism of the consumer goods market, rather than direct regulation. The annual electricity savings from the recommended program for fostering rapid adoption of efficient technologies are estimated to reach 1800 GWh by the year 2005 for urban households alone.« less

Simulation of deterministic energy-balance particle agglomeration in turbulent liquid-solid flows

NASA Astrophysics Data System (ADS)

Njobuenwu, Derrick O.; Fairweather, Michael

2017-08-01

An efficient technique to simulate turbulent particle-laden flow at high mass loadings within the four-way coupled simulation regime is presented. The technique implements large-eddy simulation, discrete particle simulation, a deterministic treatment of inter-particle collisions, and an energy-balanced particle agglomeration model. The algorithm to detect inter-particle collisions is such that the computational costs scale linearly with the number of particles present in the computational domain. On detection of a collision, particle agglomeration is tested based on the pre-collision kinetic energy, restitution coefficient, and van der Waals' interactions. The performance of the technique developed is tested by performing parametric studies on the influence of the restitution coefficient (en = 0.2, 0.4, 0.6, and 0.8), particle size (dp = 60, 120, 200, and 316 μm), Reynolds number (Reτ = 150, 300, and 590), and particle concentration (αp = 5.0 × 10-4, 1.0 × 10-3, and 5.0 × 10-3) on particle-particle interaction events (collision and agglomeration). The results demonstrate that the collision frequency shows a linear dependency on the restitution coefficient, while the agglomeration rate shows an inverse dependence. Collisions among smaller particles are more frequent and efficient in forming agglomerates than those of coarser particles. The particle-particle interaction events show a strong dependency on the shear Reynolds number Reτ, while increasing the particle concentration effectively enhances particle collision and agglomeration whilst having only a minor influence on the agglomeration rate. Overall, the sensitivity of the particle-particle interaction events to the selected simulation parameters is found to influence the population and distribution of the primary particles and agglomerates formed.

Beam efflux measurements

NASA Technical Reports Server (NTRS)

Komatsu, G. K.; Stellen, J. M., Jr.

1976-01-01

Measurements have been made of the high energy thrust ions, (Group I), high angle/high energy ions (Group II), and high angle/low energy ions (Group IV) of a mercury electron bombardment thruster in the angular divergence range from 0 deg to greater than 90 deg. The measurements have been made as a function of thrust ion current, propellant utilization efficiency, bombardment discharge voltage, screen and accelerator grid potential (accel-decel ratio) and neutralizer keeper potential. The shape of the Group IV (charge exchange) ion plume has remained essentially fixed within the range of variation of the engine operation parameters. The magnitude of the charge exchange ion flux scales with thrust ion current, for good propellant utilization conditions. For fixed thrust ion current, charge exchange ion flux increases for diminishing propellant utilization efficiency. Facility effects influence experimental accuracies within the range of propellant utilization efficiency used in the experiments. The flux of high angle/high energy Group II ions is significantly diminished by the use of minimum decel voltages on the accelerator grid. A computer model of charge exchange ion production and motion has been developed. The program allows computation of charge exchange ion volume production rate, total production rate, and charge exchange ion trajectories for "genuine" and "facilities effects" particles. In the computed flux deposition patterns, the Group I and Group IV ion plumes exhibit a counter motion.

Gravity Waves and Wind-Farm Efficiency in Neutral and Stable Conditions

NASA Astrophysics Data System (ADS)

Allaerts, Dries; Meyers, Johan

2018-02-01

We use large-eddy simulations (LES) to investigate the impact of stable stratification on gravity-wave excitation and energy extraction in a large wind farm. To this end, the development of an equilibrium conventionally neutral boundary layer into a stable boundary layer over a period of 8 h is considered, using two different cooling rates. We find that turbulence decay has considerable influence on the energy extraction at the beginning of the boundary-layer transition, but afterwards, energy extraction is dominated by geometrical and jet effects induced by an inertial oscillation. It is further shown that the inertial oscillation enhances gravity-wave excitation. By comparing LES results with a simple one-dimensional model, we show that this is related to an interplay between wind-farm drag, variations in the Froude number and the dispersive effects of vertically-propagating gravity waves. We further find that the pressure gradients induced by gravity waves lead to significant upstream flow deceleration, reducing the average turbine output compared to a turbine in isolated operation. This leads us to the definition of a non-local wind-farm efficiency, next to a more standard wind-farm wake efficiency, and we show that both can be of the same order of magnitude. Finally, an energy flux analysis is performed to further elucidate the effect of gravity waves on the flow in the wind farm.

The influence of the structural orientation of amide linkers on the serum compatibility and lung transfection properties of cationic amphiphiles.

PubMed

Srujan, Marepally; Chandrashekhar, Voshavar; Reddy, Rakesh C; Prabhakar, Rairala; Sreedhar, Bojja; Chaudhuri, Arabinda

2011-08-01

Understanding the structural parameters of cationic amphiphiles which can influence gene transfer efficiencies of cationic amphiphiles continues to remain important for designing efficient liposomal gene delivery reagents. Previously we demonstrated the influence of structural orientation of the ester linker (widely used in covalently tethering the polar head and the non-polar tails) in modulating in vitro gene transfer efficiencies of cationic amphiphiles. However, our previously described cationic amphiphiles with ester linkers failed to deliver genes under in vivo conditions. Herein we report on the development of a highly serum compatible cationic amphiphile with circulation stable amide linker which shows remarkable selectivity in transfecting mouse lung. We also demonstrate that reversing structural orientation of the amide linker adversely affects both serum compatibility and the lung selective gene transfer property. Dynamic laser light scattering and atomic force microscopic studies revealed smaller average hydrodynamic sizes of the liposomes of transfection efficient lipid than those for the liposomes of transfection incompetent analog (148 ± 1 nm vs 214 ± 4 nm). Average surface potential of the liposomes of transfection competent amphiphiles were found to be significantly higher than that for the liposomes of transfection incompetent analog (10.7 ± 5.4 mV vs 2.8 ± 1.3 mV, respectively). Findings in fluorescence resonance energy transfer and dye entrapment experiments support lower rigidity and higher biomembrane fusogenicity of the liposomes of the transfection efficient amphiphiles. Importantly, cationic lipoplexes of the novel amide-linker based amphiphile exhibited higher mouse lung selective gene transfer properties than DOTAP, one of the widely used commercially available liposomal lung transfection kits. In summary, the present findings demonstrate for the first time that amide linker structural orientation profoundly influences the serum compatibility and lung transfection efficiencies of cationic amphiphiles. Copyright © 2011 Elsevier Ltd. All rights reserved.

Camouflage target reconnaissance based on hyperspectral imaging technology

NASA Astrophysics Data System (ADS)

Hua, Wenshen; Guo, Tong; Liu, Xun

2015-08-01

Efficient camouflaged target reconnaissance technology makes great influence on modern warfare. Hyperspectral images can provide large spectral range and high spectral resolution, which are invaluable in discriminating between camouflaged targets and backgrounds. Hyperspectral target detection and classification technology are utilized to achieve single class and multi-class camouflaged targets reconnaissance respectively. Constrained energy minimization (CEM), a widely used algorithm in hyperspectral target detection, is employed to achieve one class camouflage target reconnaissance. Then, support vector machine (SVM), a classification method, is proposed to achieve multi-class camouflage target reconnaissance. Experiments have been conducted to demonstrate the efficiency of the proposed method.

Excitation of plasma waves by nonlinear currents induced by a high-frequency electromagnetic pulse

NASA Astrophysics Data System (ADS)

Grishkov, V. E.; Uryupin, S. A.

2017-03-01

Excitation of plasma waves by nonlinear currents induced by a high-frequency electromagnetic pulse is analyzed within the kinetic approach. It is shown that the most efficient source of plasma waves is the nonlinear current arising due to the gradient of the energy density of the high-frequency field. Generation of plasma waves by the drag current is usually less efficient but not negligibly small at relatively high frequencies of electron-ion collisions. The influence of electron collisions on the excitation of plasma waves by pulses of different duration is described quantitatively.

Enhanced solar evaporation of water from porous media, through capillary mediated forces and surface treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Canbazoglu, F. M.; Fan, B.; Kargar, A.

2016-08-15

The relative influence of the capillary, Marangoni, and hydrophobic forces in mediating the evaporation of water from carbon foam based porous media, in response to incident solar radiation, are investigated. It is indicated that inducing hydrophilic interactions on the surface, through nitric acid treatment of the foams, has a similar effect to reduced pore diameter and the ensuing capillary forces. The efficiency of water evaporation may be parameterized through the Capillary number (Ca), with a lower Ca being preferred. The proposed study is of much relevance to efficient solar energy utilization.

Excitation of plasma waves by nonlinear currents induced by a high-frequency electromagnetic pulse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grishkov, V. E.; Uryupin, S. A., E-mail: uryupin@sci.lebedev.ru

Excitation of plasma waves by nonlinear currents induced by a high-frequency electromagnetic pulse is analyzed within the kinetic approach. It is shown that the most efficient source of plasma waves is the nonlinear current arising due to the gradient of the energy density of the high-frequency field. Generation of plasma waves by the drag current is usually less efficient but not negligibly small at relatively high frequencies of electron–ion collisions. The influence of electron collisions on the excitation of plasma waves by pulses of different duration is described quantitatively.

10 CFR 431.16 - Test procedures for the measurement of energy efficiency.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 3 2011-01-01 2011-01-01 false Test procedures for the measurement of energy efficiency. 431.16 Section 431.16 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR... Methods of Determining Efficiency § 431.16 Test procedures for the measurement of energy efficiency. For...

10 CFR 431.16 - Test procedures for the measurement of energy efficiency.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Test procedures for the measurement of energy efficiency. 431.16 Section 431.16 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR... Methods of Determining Efficiency § 431.16 Test procedures for the measurement of energy efficiency. For...

Effect of voltage waveform on dielectric barrier discharge ozone production efficiency

NASA Astrophysics Data System (ADS)

Mericam-Bourdet, N.; Kirkpatrick, M. J.; Tuvache, F.; Frochot, D.; Odic, E.

2012-03-01

Dielectric barrier discharges (DBDs) are commonly used for gas effluent cleanup and ozone generation. For these applications, the energy efficiency of the discharge is a major concern. This paper reports on investigations carried out on the voltage shape applied to DBD reactor electrodes, aiming to evaluate a possible energy efficiency improvement for ozone production. Two DBD reactor geometries were used: pin-to-pin and cylinder-to-cylinder, both driven either by a bi-directional power supply (voltage rise rate 1 kV/μs) or by a pulsed power supply (voltage rise rate 1 kV/ns). Ozone formed in dry air was measured at the reactor outlet. Special attention was paid to discharge input power evaluation using different methods including instantaneous current-voltage product and transferred charge-applied voltage figures. The charge transferred by the discharges was also correlated to the ozone production. It is shown that, in the case of the DBD reactors under investigation, the applied voltage shape has no influence on the ozone production efficiency. For the considered voltage rise rate, the charge deposit on the dielectric inserted inside the discharge gap is the important factor (as opposed to the voltage shape) governing the efficiency of the discharge - it does this by tailoring the duration of the current peak into the tens of nanosecond range.

75 FR 69655 - Energy Efficiency and Renewable Energy Advisory Committee (ERAC)

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-15

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy Energy Efficiency and Renewable Energy Advisory Committee (ERAC) AGENCY: Department of Energy, Office of Energy Efficiency and Renewable Energy. ACTION: Notice of open meeting. SUMMARY: This notice announces the first meeting of the...

76 FR 6605 - Energy Efficiency and Renewable Energy Advisory Committee (ERAC)

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-07

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy Energy Efficiency and Renewable Energy Advisory Committee (ERAC) AGENCY: Department of Energy, Office of Energy Efficiency and Renewable Energy. ACTION: Notice of open meeting. SUMMARY: The purpose of the ERAC is to provide advice and...

77 FR 32531 - Renewable Energy and Energy Efficiency Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-01

... DEPARTMENT OF COMMERCE International Trade Administration Renewable Energy and Energy Efficiency... of an Open Meeting. SUMMARY: The Renewable Energy and Energy Efficiency Advisory Committee (RE&EEAC... energy and energy efficiency industries, including specific challenges associated with exporting. The...

Advanced oxidation technology for H2S odor gas using non-thermal plasma

NASA Astrophysics Data System (ADS)

Tao, ZHU; Ruonan, WANG; Wenjing, BIAN; Yang, CHEN; Weidong, JING

2018-05-01

Non-thermal plasma technology is a new type of odor treatment processing. We deal with H2S from waste gas emission using non-thermal plasma generated by dielectric barrier discharge. On the basis of two criteria, removal efficiency and absolute removal amount, we deeply investigate the changes in electrical parameters and process parameters, and the reaction process of the influence of ozone on H2S gas removal. The experimental results show that H2S removal efficiency is proportional to the voltage, frequency, power, residence time and energy efficiency, while it is inversely proportional to the initial concentration of H2S gas, and ozone concentration. This study lays the foundations of non-thermal plasma technology for further commercial application.

Energy and Water Efficiency on Campus | NREL

Science.gov Websites

Energy and Water Efficiency on Campus Energy and Water Efficiency on Campus NREL ensures the resiliency of our future energy and water systems through energy efficiency strategies and technologies , renewable energy, and water efficiency on the NREL campus. FY17 Energy Intensity. The South Table Mountain

76 FR 80355 - Energy Efficiency and Renewable Energy Advisory Committee (ERAC)

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-23

... DEPARTMENT OF ENERGY Energy Efficiency and Renewable Energy Advisory Committee (ERAC) AGENCY: Department of Energy, Office of Energy Efficiency and Renewable Energy. ACTION: Notice of open teleconference... efficiency and renewable energy. The Federal Advisory Committee Act, Public Law 92- 463, 86 Stat. 770...

76 FR 54224 - Energy Efficiency and Renewable Energy Advisory Committee (ERAC)

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-31

... DEPARTMENT OF ENERGY Energy Efficiency and Renewable Energy Advisory Committee (ERAC) AGENCY: Department of Energy, Office of Energy Efficiency and Renewable Energy. ACTION: Notice of open meeting... efficiency and renewable energy. The Federal Advisory Committee Act, Public Law 92-463, 86 Stat. 770...

Conformational free energy modeling of druglike molecules by metadynamics in the WHIM space.

PubMed

Spiwok, Vojtěch; Hlat-Glembová, Katarína; Tvaroška, Igor; Králová, Blanka

2012-03-26

Protein-ligand affinities can be significantly influenced not only by the interaction itself but also by conformational equilibrium of both binding partners, free ligand and free protein. Identification of important conformational families of a ligand and prediction of their thermodynamics is important for efficient ligand design. Here we report conformational free energy modeling of nine small-molecule drugs in explicitly modeled water by metadynamics with a bias potential applied in the space of weighted holistic invariant molecular (WHIM) descriptors. Application of metadynamics enhances conformational sampling compared to unbiased molecular dynamics simulation and allows to predict relative free energies of key conformations. Selected free energy minima and one example of transition state were tested by a series of unbiased molecular dynamics simulation. Comparison of free energy surfaces of free and target-bound Imatinib provides an estimate of free energy penalty of conformational change induced by its binding to the target. © 2012 American Chemical Society

76 FR 71312 - Renewable Energy and Energy Efficiency Advisory Committee Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-17

... DEPARTMENT OF COMMERCE International Trade Administration Renewable Energy and Energy Efficiency...: Notice of an Open Meeting. SUMMARY: The Renewable Energy and Energy Efficiency Advisory Committee (RE... competitiveness of the U.S. renewable energy and energy efficiency industries, including specific challenges...

78 FR 78340 - Renewable Energy and Energy Efficiency Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-26

... DEPARTMENT OF COMMERCE International Trade Administration Renewable Energy and Energy Efficiency... of an Open Meeting. SUMMARY: The Renewable Energy and Energy Efficiency Advisory Committee (RE&EEAC... affecting U.S. competitiveness in exporting renewable energy and energy efficiency (RE&EE) products and...

76 FR 54431 - Renewable Energy and Energy Efficiency Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-01

... DEPARTMENT OF COMMERCE International Trade Administration Renewable Energy and Energy Efficiency... of an Open Meeting. SUMMARY: The Renewable Energy and Energy Efficiency Advisory Committee (RE&EEAC... competitiveness of the U.S. renewable energy and energy efficiency industries, including specific challenges...

Effective sulfur and energy recovery from hydrogen sulfide through incorporating an air-cathode fuel cell into chelated-iron process.

PubMed

Sun, Min; Song, Wei; Zhai, Lin-Feng; Cui, Yu-Zhi

2013-12-15

The chelated-iron process is among the most promising techniques for the hydrogen sulfide (H2S) removal due to its double advantage of waste minimization and resource recovery. However, this technology has encountered the problem of chelate degradation which made it difficult to ensure reliable and economical operation. This work aims to develop a novel fuel-cell-assisted chelated-iron process which employs an air-cathode fuel cell for the catalyst regeneration. By using such a process, sulfur and electricity were effectively recovered from H2S and the problem of chelate degradation was well controlled. Experiment on a synthetic sulfide solution showed the fuel-cell-assisted chelated-iron process could maintain high sulfur recovery efficiencies generally above 90.0%. The EDTA was preferable to NTA as the chelating agent for electricity generation, given the Coulombic efficiencies (CEs) of 17.8 ± 0.5% to 75.1 ± 0.5% for the EDTA-chelated process versus 9.6 ± 0.8% to 51.1 ± 2.7% for the NTA-chelated process in the pH range of 4.0-10.0. The Fe (III)/S(2-) ratio exhibited notable influence on the electricity generation, with the CEs improved by more than 25% as the Fe (III)/S(2-) molar ratio increased from 2.5:1 to 3.5:1. Application of this novel process in treating a H2S-containing biogas stream achieved 99% of H2S removal efficiency, 78% of sulfur recovery efficiency, and 78.6% of energy recovery efficiency, suggesting the fuel-cell-assisted chelated-iron process was effective to remove the H2S from gas streams with favorable sulfur and energy recovery efficiencies. Copyright © 2013 Elsevier B.V. All rights reserved.

Measuring energy efficiency in economics: Shadow value approach

NASA Astrophysics Data System (ADS)

Khademvatani, Asgar

For decades, academic scholars and policy makers have commonly applied a simple average measure, energy intensity, for studying energy efficiency. In contrast, we introduce a distinctive marginal measure called energy shadow value (SV) for modeling energy efficiency drawn on economic theory. This thesis demonstrates energy SV advantages, conceptually and empirically, over the average measure recognizing marginal technical energy efficiency and unveiling allocative energy efficiency (energy SV to energy price). Using a dual profit function, the study illustrates how treating energy as quasi-fixed factor called quasi-fixed approach offers modeling advantages and is appropriate in developing an explicit model for energy efficiency. We address fallacies and misleading results using average measure and demonstrate energy SV advantage in inter- and intra-country energy efficiency comparison. Energy efficiency dynamics and determination of efficient allocation of energy use are shown through factors impacting energy SV: capital, technology, and environmental obligations. To validate the energy SV, we applied a dual restricted cost model using KLEM dataset for the 35 US sectors stretching from 1958 to 2000 and selected a sample of the four sectors. Following the empirical results, predicted wedges between energy price and the SV growth indicate a misallocation of energy use in stone, clay and glass (SCG) and communications (Com) sectors with more evidence in the SCG compared to the Com sector, showing overshoot in energy use relative to optimal paths and cost increases from sub-optimal energy use. The results show that energy productivity is a measure of technical efficiency and is void of information on the economic efficiency of energy use. Decomposing energy SV reveals that energy, capital and technology played key roles in energy SV increases helping to consider and analyze policy implications of energy efficiency improvement. Applying the marginal measure, we also contributed to energy efficiency convergence analysis employing the delta-convergence and unconditional & conditional beta-convergence concepts, investigating economic energy efficiency differences across the four US sectors using panel data models. The results show that, in terms of technical and allocative energy efficiency, the energy-intensive sectors, SCG and textile mill products, tend to catch the energy extensive sectors, the Com and furniture & fixtures, being conditional on sector-specific characteristics. Conditional convergence results indicate that technology, capital and energy are crucial factors in determining energy efficiency differences across the US sectors, implying that environmental or energy policies, and technological changes should be industry specific across the US sectors. The main finding is that the marginal value measure conveys information on both technical and allocative energy efficiency and accounts for all costs and benefits of energy consumption including environmental and externality costs.

An empirical analysis of financial development and energy demand: establishing the role of globalization.

PubMed

Saud, Shah; Danish; Chen, Songsheng

2018-06-14

The rapid mode of globalization is experienced in the last few years. The acceleration in globalization expands economic activities through a share of knowledge and transfer of technology which influence energy demand. So, the objective of this empirical work is to explore the impact of financial development on energy demand incorporating globalization. The empirical finding is based on autoregressive distributed lag (ARDL) bound testing approach from 1980 to 2016 in case of China. Overall, we infer that financial development increases energy demand in China. Furthermore, the finding shows that globalization has a negative and significant impact on energy demand. The additional determinants, such as economic growth, and urbanization stimulate energy consumption. Besides, energy consumption granger cause financial development in the long-run path. Similarly, unidirectional causality is detected between globalization and energy consumption. The result gives direction to policymakers to preserve as well as to enhance efficient energy consumption and sustain economic growth in China with acceleration in globalization.

Controlled supercontinua via spatial beam shaping

NASA Astrophysics Data System (ADS)

Zhdanova, Alexandra A.; Shen, Yujie; Thompson, Jonathan V.; Scully, Marlan O.; Yakovlev, Vladislav V.; Sokolov, Alexei V.

2018-06-01

Recently, optimization techniques have had a significant impact in a variety of fields, leading to a higher signal-to-noise and more streamlined techniques. We consider the possibility for using programmable phase-only spatial optimization of the pump beam to influence the supercontinuum generation process. Preliminary results show that significant broadening and rough control of the supercontinuum spectrum in the visible region are possible without loss of input energy. This serves as a proof-of-concept demonstration that spatial effects can controllably influence the supercontinuum spectrum, leading to possibilities for utilizing supercontinuum power more efficiently and achieving excellent spectral control.

75 FR 35450 - Establishment of the Energy Efficiency and Renewable Energy Advisory Committee and Request for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-22

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy Establishment of the Energy Efficiency and Renewable Energy Advisory Committee and Request for Member Nominations AGENCY: Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy. ACTION: Notice of Intent to Establish...

78 FR 29749 - Office of Energy Efficiency and Renewable Energy; Agency Information Collection Extension

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-21

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy; Agency Information Collection Extension AGENCY: Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy (DOE..., DC 20503 And to Mr. Dana O'Hara, Office of Energy Efficiency and Renewable Energy (EE- 2G), U.S...

77 FR 4999 - Decision and Order Granting a Waiver to LG From the Department of Energy Clothes Washer Test...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-01

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy [Case No. CW-022] Decision...: Office of Energy Efficiency and Renewable Energy, Department of Energy. ACTION: Decision and Order.... Hogan, Deputy Assistant Secretary for Energy Efficiency, Energy Efficiency and Renewable Energy...

Seeking Energy System Pathways to Reduce Ozone Damage to Ecosystems through Adjoint-based Sensitivity Analysis

NASA Astrophysics Data System (ADS)

Capps, S. L.; Pinder, R. W.; Loughlin, D. H.; Bash, J. O.; Turner, M. D.; Henze, D. K.; Percell, P.; Zhao, S.; Russell, M. G.; Hakami, A.

2014-12-01

Tropospheric ozone (O3) affects the productivity of ecosystems in addition to degrading human health. Concentrations of this pollutant are significantly influenced by precursor gas emissions, many of which emanate from energy production and use processes. Energy system optimization models could inform policy decisions that are intended to reduce these harmful effects if the contribution of precursor gas emissions to human health and ecosystem degradation could be elucidated. Nevertheless, determining the degree to which precursor gas emissions harm ecosystems and human health is challenging because of the photochemical production of ozone and the distinct mechanisms by which ozone causes harm to different crops, tree species, and humans. Here, the adjoint of a regional chemical transport model is employed to efficiently calculate the relative influences of ozone precursor gas emissions on ecosystem and human health degradation, which informs an energy system optimization. Specifically, for the summer of 2007 the Community Multiscale Air Quality (CMAQ) model adjoint is used to calculate the location- and sector-specific influences of precursor gas emissions on potential productivity losses for the major crops and sensitive tree species as well as human mortality attributable to chronic ozone exposure in the continental U.S. The atmospheric concentrations are evaluated with 12-km horizontal resolution with crop production and timber biomass data gridded similarly. These location-specific factors inform the energy production and use technologies selected in the MARKet ALlocation (MARKAL) model.

Elastic layer under axisymmetric indentation and surface energy effects

NASA Astrophysics Data System (ADS)

Intarit, Pong-in; Senjuntichai, Teerapong; Rungamornrat, Jaroon

2018-04-01

In this paper, a continuum-based approach is adopted to investigate the contact problem of an elastic layer with finite thickness and rigid base subjected to axisymmetric indentation with the consideration of surface energy effects. A complete Gurtin-Murdoch surface elasticity is employed to consider the influence of surface stresses. The indentation problem of a rigid frictionless punch with arbitrary axisymmetric profiles is formulated by employing the displacement Green's functions, derived with the aid of Hankel integral transform technique. The problem is solved by assuming the contact pressure distribution in terms of a linear combination of admissible functions and undetermined coefficients. Those coefficients are then obtained by employing a collocation technique and an efficient numerical quadrature scheme. The accuracy of proposed solution technique is verified by comparing with existing solutions for rigid indentation on an elastic half-space. Selected numerical results for the indenters with flat-ended cylindrical and paraboloidal punch profiles are presented to portray the influence of surface energy effects on elastic fields of the finite layer. It is found that the presence of surface stresses renders the layer stiffer, and the size-dependent behavior of elastic fields is observed in the present solutions. In addition, the surface energy effects become more pronounced with smaller contact area; thus, the influence of surface energy cannot be ignored in the analysis of indentation problem especially when the indenter size is very small such as in the case of nanoindentation.

Numerical simulations of dielectric barrier discharges

NASA Astrophysics Data System (ADS)

Martens, Tom

A plasma or gas discharge is a state of matter which can be described as a gas containing ionized atoms and molecules. This ionized gas exhibits a collective behaviour under influence of an electric or a magnetic field, which are responsible for unique properties which make all new kinds of technology possible. The most important motivation behind the research is finding more efficient ways to produce a low-temperature plasma. In order to achieve this different reactor geometries are studied, it is investigated which is the most suitable power source and the influence of small contaminations of the operating gas is assessed. The studied plasmas are mainly operated at atmospheric pressure. Working at this pressure is cheaper and it makes it possible to develop assembly line treatments. Such plasmas are most easily generated in very small geometries, although energetic derailment of the discharge becomes a substantial risk. This is avoided when the electrodes are electrically insulated. In such setup the insulators accumulate charges which compensate the governing electric field, which keeps the energy transfer to the discharge limited. By studying these discharges using computer models, the changes in the plasma chemistry in time and also under the influence of different levels of impurities were characterized in great detail. Moreover, it was also determined how these chemical changes determine the electrical characteristics of the plasma. Finally, the insights in the charging and discharging effects of the insulators were used to make predictions on which type of power source is the most efficient in using the potential energy stored on the insulator surface to generate the plasma. The most important conclusions are that molecular impurities of the order of only one part per million already dominate the ionic particle distributions in the plasma and that a well-designed alteration in the applied voltage profile leads to a plasma generation with a more than three times more efficient use of consumed energy. This way the research contributes to the insight in the operation and forms the base for new and improved applications and technologies.

77 FR 23224 - Renewable Energy and Energy Efficiency Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-18

... DEPARTMENT OF COMMERCE International Trade Administration Renewable Energy and Energy Efficiency... of an open meeting. SUMMARY: The Renewable Energy and Energy Efficiency Advisory Committee (RE&EEAC.... competitiveness in exporting renewable energy and energy efficiency (RE&EE) products and services, such as access...

10 CFR 435.4 - Energy efficiency performance standard.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Energy efficiency performance standard. 435.4 Section 435.4 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise Residential...

10 CFR 435.4 - Energy efficiency performance standard.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Energy efficiency performance standard. 435.4 Section 435.4 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise Residential...

10 CFR 435.4 - Energy efficiency performance standard.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 3 2013-01-01 2013-01-01 false Energy efficiency performance standard. 435.4 Section 435.4 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise Residential...

10 CFR 435.4 - Energy efficiency performance standard.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Energy efficiency performance standard. 435.4 Section 435.4 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise Residential...

10 CFR 433.7 - Water used to achieve energy efficiency. [Reserved

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Water used to achieve energy efficiency. [Reserved] 433.7 Section 433.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR THE DESIGN... Water used to achieve energy efficiency. [Reserved] ...

10 CFR 435.4 - Energy efficiency performance standard.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 3 2011-01-01 2011-01-01 false Energy efficiency performance standard. 435.4 Section 435.4 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise Residential...

10 CFR 433.7 - Water used to achieve energy efficiency. [Reserved

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 3 2011-01-01 2011-01-01 false Water used to achieve energy efficiency. [Reserved] 433.7 Section 433.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR THE DESIGN... Water used to achieve energy efficiency. [Reserved] ...

Gas pollutants removal in a single- and two-stage ejector-venturi scrubber.

PubMed

Gamisans, Xavier; Sarrà, Montserrrat; Lafuente, F Javier

2002-03-29

The absorption of SO(2) and NH(3) from the flue gas into NaOH and H(2)SO(4) solutions, respectively has been studied using an industrial scale ejector-venturi scrubber. A statistical methodology is presented to characterise the performance of the scrubber by varying several factors such as gas pollutant concentration, air flowrate and absorbing solution flowrate. Some types of venturi tube constructions were assessed, including the use of a two-stage venturi tube. The results showed a strong influence of the liquid scrubbing flowrate on pollutant removal efficiency. The initial pollutant concentration and the gas flowrate had a slight influence. The use of a two-stage venturi tube considerably improved the absorption efficiency, although it increased energy consumption. The results of this study will be applicable to the optimal design of venturi-based absorbers for gaseous pollution control or chemical reactors.

Comparative evaluation of surface and downhole steam-generation techniques

NASA Astrophysics Data System (ADS)

Hart, C.

The application of heat to reservoirs containing high API gravity oils can substantially improve recovery. Although steam injection is currently the principal thermal recovery method, heat transmission losses associated with delivery of the steam from the surface generators to the oil bearing formation has limited conventional steam injection to shallow reservoirs. The objective of the Department of Energy's Project DEEP STEAM is to develop the technology required to economically produce heavy oil from deep reservoirs. The tasks included in this effort are the development and evaluation of thermally efficient delivery systems and downhole steam generation systems. The technical and economic performance of conventional surface steam drives, which are strongly influenced by heat losses are compared. The selection of a preferred technology based upon either total efficiency or cost is found to be strongly influenced by reservoir depth, steam mass flow rate, and sandface steam quality.

Thermogravimetric characterization and gasification of pecan nut shells.

PubMed

Aldana, Hugo; Lozano, Francisco J; Acevedo, Joaquín; Mendoza, Alberto

2015-12-01

This study focuses on the evaluation of pecan nut shells as an alternative source of energy through pyrolysis and gasification. The physicochemical characteristics of the selected biomass that can influence the process efficiency, consumption rates, and the product yield, as well as create operational problems, were determined. In addition, the thermal decomposition kinetics necessary for prediction of consumption rates and yields were determined. Finally, the performance of a downdraft gasifier fed with pecan nut shells was analyzed in terms of process efficiency and exit gas characteristics. It was found that the pyrolytic decomposition of the nut shells can be modeled adequately using a single equation considering two independent parallel reactions. The performance of the gasification process can be influenced by the particle size and air flow rate, requiring a proper combination of these parameters for reliable operation and production of a valuable syngas. Copyright © 2015 Elsevier Ltd. All rights reserved.

Survey of ion plating sources. [conferences

NASA Technical Reports Server (NTRS)

Spalvins, T.

1979-01-01

Based on the type of evaporation source, gaseous media and mode of transport, the following is discussed: resistance, electron beam, sputtering, reactive and ion beam evaporation. Ionization efficiencies and ion energies in the glow discharge determine the percentage of atoms which are ionized under typical ion plating conditions. The plating flux consists of a small number of energetic ions and a large number of energetic neutrals. The energy distribution ranges from thermal energies up to a maximum energy of the discharge. The various reaction mechanisms which contribute to the exceptionally strong adherence - formation of a graded sustrate/coating interface are not fully understood, however the controlling factors are evaluated. The influence of process variables on the nucleation and growth characteristics are illustrated in terms of morphological changes which affect the mechanical and tribological properties of the coating.

EFFECTS OF LASER RADIATION ON MATTER: Influence of the ambient air pressure on short-wavelength radiation from a laser plasma

NASA Astrophysics Data System (ADS)

Golovin, A. F.; Zemtsov, S. S.; Fedyushin, B. T.

1991-12-01

A detailed experimental investigation was made of the radiation from a plasma created on an aluminum target by a pulsed CO2 laser at different ambient gas pressures. Measurements were made of the energy and angular distribution of the radiation and of the efficiency of conversion of laser energy into reemitted plasma radiation. The intensity of this radiation was found to exhibit pressure-dependent pulsations. The maximum reflection of the laser radiation from the plasma was recorded at a pressure of ~ 40 Torr. An interpretation is given of the experimental data.

78 FR 2952 - Renewable Energy and Energy Efficiency Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-15

... DEPARTMENT OF COMMERCE International Trade Administration Renewable Energy and Energy Efficiency... of an open meeting. SUMMARY: The Renewable Energy and Energy Efficiency Advisory Committee (RE&EEAC... competitiveness of U.S. renewable energy and energy efficiency exports. The meeting is open to the public and the...

10 CFR 433.4 - Energy efficiency performance standard.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Energy efficiency performance standard. 433.4 Section 433.4 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL BUILDINGS § 433.4 Energy efficiency performance standard...

10 CFR 433.4 - Energy efficiency performance standard.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Energy efficiency performance standard. 433.4 Section 433.4 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL BUILDINGS § 433.4 Energy efficiency performance standard...

10 CFR 433.4 - Energy efficiency performance standard.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 3 2013-01-01 2013-01-01 false Energy efficiency performance standard. 433.4 Section 433.4 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL BUILDINGS § 433.4 Energy efficiency performance standard...

Electrical energy per order and current efficiency for electrochemical oxidation of p-chlorobenzoic acid with boron-doped diamond anode.

PubMed

Lanzarini-Lopes, Mariana; Garcia-Segura, Sergi; Hristovski, Kiril; Westerhoff, Paul

2017-12-01

Electrochemical oxidation (EO) is an advanced oxidation process for water treatment to mineralize organic contaminants. While proven to degrade a range of emerging pollutants in water, less attention has been given to quantify the effect of operational variables such applied current density and pollutant concentration on efficiency and energy requirements. Particular figures of merit were mineralization current efficiency (MCE) and electrical energy per order (E EO ). Linear increases of applied current exponentially decreased the MCE due to the enhancement of undesired parasitic reactions that consumed generated hydroxyl radical. E EO values ranged from 39.3 to 331.8 kW h m -3 order -1 . Increasing the applied current also enhanced the E EO due to the transition from kinetics limited by current to kinetics limited by mass transfer. Further increases in current did not influence the removal rate, but it raised the E EO requirement. The E EO requirement diminished when decreasing initial pollutant loading with the increase of the apparent kinetic rate because of the relative availability of oxidant per pollutant molecule in solution at a defined current. Oxidation by-products released were identified, and a plausible degradative pathway has been suggested. Copyright © 2017. Published by Elsevier Ltd.

Zr-doped TiO2 as a thermostabilizer in plasmon-enhanced dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Pasche, Anastasia; Grohe, Bernd; Mittler, Silvia; Charpentier, Paul A.

2017-07-01

Harvesting solar energy is a promising solution toward meeting the world's ever-growing energy demand. Dye-sensitized solar cells (DSSCs) are hybrid organic-inorganic solar cells with tremendous potential for commercial application, but they are plagued by inefficiency due to their poor sunlight absorption. Plasmonic silver nanoparticles (AgNPs) have been shown to enhance the absorptive properties of DSSCs, but their plasmonic resonance can cause thermal damage resulting in cell deterioration. Hence, the influence of Zr-doped TiO2 on the efficiency of plasmon-enhanced DSSCs was studied, showing that 5 mol.% Zr-doping of the photoactive TiO2 material can improve the photovoltaic performance of DSSCs by 44%. By examining three different DSSC designs, it became clear that the efficiency enhancing effect of Zr strongly depends on the proximity of the Zr-doped material to the plasmonic AgNPs.

A molecular theory for optimal blue energy extraction by electrical double layer expansion

DOE PAGES

Kong, Xian; Gallegos, Alejandro; Lu, Diannan; ...

2015-08-19

We proposed the electrical double layer expansion (CDLE) as a promising alternative to reverse electrodialysis (RED) and pressure retarded osmosis (PRO) processes for extracting osmotic power generated by the salinity difference between freshwater and seawater. The performance of the CDLE process is sensitive to the configuration of porous electrodes and operation parameters for ion extraction and release cycles. In our work, we use a classical density functional theory (CDFT) to examine how the electrode pore size and charging/discharging potentials influence the thermodynamic efficiency of the CDLE cycle. The existence of an optimal charging potential that maximizes the energy output formore » a given pore configuration is predicted, which varies substantially with the pore size, especially when it is smaller than 2 nm. Finally, the thermodynamic efficiency is maximized when the electrode has a pore size about twice the ion diameter.« less

Tin-Doped Inorganic Amorphous Films for Use as Transparent Monolithic Phosphors.

PubMed

Masai, Hirokazu; Miyata, Hiroki; Yamada, Yasuhiro; Okumura, Shun; Yanagida, Takayuki; Kanemitsu, Yoshihiko

2015-06-10

Although inorganic crystalline phosphors can exhibit high quantum efficiency, their use in phosphor films has been limited by a reliance on organic binders that have poor durability when exposed to high-power and/or high excitation energy light sources. To address this problem, Sn(2+)-doped transparent phosphate films measuring several micrometers in thickness have been successfully prepared through heat treatment and a subsequent single dip-coating process. The resulting monolithic inorganic amorphous film exhibited an internal quantum efficiency of over 60% and can potentially utilize transmitted light. Analysis of the film's emissivity revealed that its color can be tuned by changing the amount of Mn and Sn added to influence the energy transfer from Sn(2+) to Mn(2+). It is therefore concluded that amorphous films containing such emission centers can provide a novel and viable alternative to conventional amorphous films containing crystalline phosphors in light-emitting devices.

Tin-Doped Inorganic Amorphous Films for Use as Transparent Monolithic Phosphors

PubMed Central

Masai, Hirokazu; Miyata, Hiroki; Yamada, Yasuhiro; Okumura, Shun; Yanagida, Takayuki; Kanemitsu, Yoshihiko

2015-01-01

Although inorganic crystalline phosphors can exhibit high quantum efficiency, their use in phosphor films has been limited by a reliance on organic binders that have poor durability when exposed to high-power and/or high excitation energy light sources. To address this problem, Sn2+ -doped transparent phosphate films measuring several micrometers in thickness have been successfully prepared through heat treatment and a subsequent single dip-coating process. The resulting monolithic inorganic amorphous film exhibited an internal quantum efficiency of over 60% and can potentially utilize transmitted light. Analysis of the film’s emissivity revealed that its color can be tuned by changing the amount of Mn and Sn added to influence the energy transfer from Sn2+ to Mn2+. It is therefore concluded that amorphous films containing such emission centers can provide a novel and viable alternative to conventional amorphous films containing crystalline phosphors in light-emitting devices. PMID:26061744

77 FR 75428 - Decision and Order Granting a Waiver to Samsung From the Department of Energy Residential...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-20

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy [Case No. RF-021] Decision... Refrigerator-Freezer Test Procedures AGENCY: Office of Energy Efficiency and Renewable Energy, Department of... Assistant Secretary for Energy Efficiency, Energy Efficiency and Renewable Energy. Decision and Order In the...

78 FR 53374 - Energy Conservation Program for Consumer Products: Test Procedures for Refrigerators...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-29

... Freezers AGENCY: Office of Energy Efficiency and Renewable Energy, Department of Energy. ACTION: Extension... INFORMATION CONTACT: Mr. Lucas Adin, U.S. Department of Energy, Office of Energy Efficiency and Renewable... Energy Efficiency, Energy Efficiency and Renewable Energy. [FR Doc. 2013-21115 Filed 8-28-13; 8:45 am...

The influence of multifamily apartment building occupants on energy and water consumption - the preliminary results of monitoring and survey campaign

NASA Astrophysics Data System (ADS)

Bandurski, Karol; Hamerla, Miłosz; Szulc, Jowita; Koczyk, Halina

2017-11-01

Occupants' attitudes and behavior have a significant influence on energy and water consumption in buildings. To provide more robust solutions, energy efficient applications should consider occupant-building interaction. However, there is a question to be answered: which aspects of lodging and occupant behavior cause the most substantial increase in consumption of these mediums. Thus, the aim of this study is to investigate the influence of household characteristics and occupants' behavior on level and variability in utilities consumption. The study uses the results of a measuring campaign and the questionnaire. The measuring campaign was carried out to monitor the consumption of energy used for space heating and domestic hot water, as well as electricity, gas and water. The questionnaire specifically focused on household characteristics and occupants' behavior. The research was carried out in four apartment buildings, all consisting of more than 100 apartments. Data from approximately 100 households was gathered and analyzed; the survey's respond rate was almost 50%. A quantitative analysis of the results confirms the assumption that both household characteristics and occupants' behavior (e.g. the use of heating control) are important factors for utilities consumption. Further work with the obtained data is planned in terms of including of greater number of apartments, assessment of ventilation effectiveness, as well as analysis of heat transfer between the apartments.

Experimental investigations of hybrid PV/Spiral flow thermal collector system performance using Al2O3/water nanofluid

NASA Astrophysics Data System (ADS)

Gangadevi, R.; Vinayagam, B. K.; Senthilraja, S.

2017-05-01

In this paper, the PV/T (Photovoltaic thermal unit) system is investigated experimentally to examine the thermal, electrical and overall efficiency by circulating Al2O3/water nanofluid of 1wt% and 2wt% with an optimum flow rate of 40L/H. The overall efficiency of PVT system is largely influenced by various factors such as heat due to photovoltaic action; energy radiated at the infrared wavelength of the solar spectrum, solar irradiance, mounting structure, tilt angle, wind speed direction, Ambient temperature and panel material composition. However, the major factor is considered in this study to extract the heat generated in the PV panel by using nanofluid as a coolant to increase the overall system efficiency. Therefore, the result shows that by using 2 wt% Al2O3/water nanofluid the electrical efficiency, thermal efficiency and overall efficiency of the PVT system enhanced by 13%, 45%, and 58% respectively compared with water.

77 FR 14509 - State Energy Program and Energy Efficiency and Conservation Block Grant (EECBG) Program; Request...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-12

... DEPARTMENT OF ENERGY [Docket No. EESEP0216] State Energy Program and Energy Efficiency and Conservation Block Grant (EECBG) Program; Request for Information AGENCY: Office of Energy Efficiency and... (SEP) and Energy Efficiency and Conservation Block Grant (EECBG) program, in support of energy...

10 CFR 435.7 - Water used to achieve energy efficiency. [Reserved

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 3 2011-01-01 2011-01-01 false Water used to achieve energy efficiency. [Reserved] 435.7 Section 435.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise Residential...

10 CFR 431.97 - Energy efficiency standards and their effective dates.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 3 2011-01-01 2011-01-01 false Energy efficiency standards and their effective dates. 431.97 Section 431.97 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Air Conditioners and Heat Pumps Energy Efficiency...

10 CFR 435.7 - Water used to achieve energy efficiency. [Reserved

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Water used to achieve energy efficiency. [Reserved] 435.7 Section 435.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise Residential...

10 CFR 431.97 - Energy efficiency standards and their compliance dates.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 3 2013-01-01 2013-01-01 false Energy efficiency standards and their compliance dates. 431.97 Section 431.97 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Air Conditioners and Heat Pumps Energy Efficiency...

10 CFR 431.97 - Energy efficiency standards and their effective dates.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Energy efficiency standards and their effective dates. 431.97 Section 431.97 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Air Conditioners and Heat Pumps Energy Efficiency...

10 CFR 435.7 - Water used to achieve energy efficiency. [Reserved

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Water used to achieve energy efficiency. [Reserved] 435.7 Section 435.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise Residential...

10 CFR 431.97 - Energy efficiency standards and their compliance dates.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Energy efficiency standards and their compliance dates. 431.97 Section 431.97 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Air Conditioners and Heat Pumps Energy Efficiency...

10 CFR 435.7 - Water used to achieve energy efficiency. [Reserved

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Water used to achieve energy efficiency. [Reserved] 435.7 Section 435.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise Residential...

10 CFR 431.97 - Energy efficiency standards and their effective dates.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Energy efficiency standards and their effective dates. 431.97 Section 431.97 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Air Conditioners and Heat Pumps Energy Efficiency...

Use of ultrasound in leather processing industry: effect of sonication on substrate and substances--new insights.

PubMed

Sivakumar, Venkatasubramanian; Swaminathan, Gopalaraman; Rao, Paruchuri Gangadhar; Muralidharan, Chellappa; Mandal, Asit Baran; Ramasami, Thirumalachari

2010-08-01

Influence of ultrasound (US) on various unit operations in leather processing has been studied with the aim to improve the process efficiency, quality, reduce process time and achieve near-zero discharge levels in effluent streams as a cleaner option. Effect of US on substrate (skin/leather) matrix as well as substances used in different unit operations have been studied and found to be useful in the processing. Absorption of US energy by leather in process vessel at different distances from US source has been measured and found to be significant. Effect of particle-size of different substances due to sonication indicates positive influence on the diffusion through the matrix. Our experimental results suggest that US effect is better realized for the cases with pronounced diffusion hindrance. Influence of US on bioprocessing of leather has been studied and found beneficial. Attempts have also been made to improve the US aided processing using external aids. Operating US in pulse mode operation could be useful in order to reduce the electrical energy consumption. Use of US has also been studied in the preparation of leather auxiliaries involving mass-transfer resistance. Preliminary cost analysis carried out for ultrasound-assisted leather-dyeing process indicates scale-up possibility. Therefore, US application provide improvement in process efficiency as well as making cleaner production methods feasible. Hence, overall results suggest that use of US in leather industry is imminent and potential viable option in near future. Copyright 2009 Elsevier B.V. All rights reserved.

Theoretical Study of Methods for Improving the Energy Efficiency of NOx Removal from Diesel Exhaust Gases by Silent Discharge

NASA Astrophysics Data System (ADS)

Shoyama, Taiji; Yoshioka, Yoshio

To improve the NO removal performance in silent discharge process, we investigated the influence of the physical parameters such as current density, channel radius and pulse duration of the one micro discharge under the constant reduced electric field strength. And influence of the micro discharges occurrence locations were also discussed. In order to analyze the NO removal process, we assumed that the pulse micro discharges occur repeatedly at the same location in static gas and that the chemical reactions induced by micro discharge forms many radicals, which react with pollutants and by-products. The conclusions we obtained are that lower current density, smaller discharge radius and shorter discharge duration improve NO removal efficiency. These results also mean that the lower discharge energy of the one micro discharge and the larger number of parallel micro discharges increase the NO removal performance. Therefore, to make the area of one micro discharge small is a desirable way to improve the NO removal performance. So we think that the glow like discharge might be more effective than the streamer like discharge mode. Next, using the two-dimensional model, which considered the influence of gas flow, we obtained a conclusion that the repeated micro discharges at different positions are very effective to increase the De-NOx performance. The reason is that the reaction of NO2+O→NO+O2 and ozone dissociation reactions are suppressed by the movement of the location of micro discharges.

Efficient Double Auction Mechanisms in the Energy Grid with Connected and Islanded Microgrids

NASA Astrophysics Data System (ADS)

Faqiry, Mohammad Nazif

The future energy grid is expected to operate in a decentralized fashion as a network of autonomous microgrids that are coordinated by a Distribution System Operator (DSO), which should allocate energy to them in an efficient manner. Each microgrid operating in either islanded or grid-connected mode may be considered to manage its own resources. This can take place through auctions with individual units of the microgrid as the agents. This research proposes efficient auction mechanisms for the energy grid, with is-landed and connected microgrids. The microgrid level auction is carried out by means of an intermediate agent called an aggregator. The individual consumer and producer units are modeled as selfish agents. With the microgrid in islanded mode, two aggregator-level auction classes are analyzed: (i) price-heterogeneous, and (ii) price homogeneous. Under the price heterogeneity paradigm, this research extends earlier work on the well-known, single-sided Kelly mechanism to double auctions. As in Kelly auctions, the proposed algorithm implements the bidding without using any agent level private infor-mation (i.e. generation capacity and utility functions). The proposed auction is shown to be an efficient mechanism that maximizes the social welfare, i.e. the sum of the utilities of all the agents. Furthermore, the research considers the situation where a subset of agents act as a coalition to redistribute the allocated energy and price using any other specific fairness criterion. The price homogeneous double auction algorithm proposed in this research ad-dresses the problem of price-anticipation, where each agent tries to influence the equilibri-um price of energy by placing strategic bids. As a result of this behavior, the auction's efficiency is lowered. This research proposes a novel approach that is implemented by the aggregator, called virtual bidding, where the efficiency can be asymptotically maximized, even in the presence of price anticipatory bidders. Next, an auction mechanism for the energy grid, with multiple connected mi-crogrids is considered. A globally efficient bi-level auction algorithm is proposed. At the upper-level, the algorithm takes into account physical grid constraints in allocating energy to the microgrids. It is implemented by the DSO as a linear objective quadratic constraint problem that allows price heterogeneity across the aggregators. In parallel, each aggrega-tor implements its own lower-level price homogeneous auction with virtual bidding. The research concludes with a preliminary study on extending the DSO level auc-tion to multi-period day-ahead scheduling. It takes into account storage units and conven-tional generators that are present in the grid by formulating the auction as a mixed inte-ger linear programming problem.

Energy Efficiency Roadmap for Uganda, Making Energy Efficiency Count. Executive Summary

DOE Office of Scientific and Technical Information (OSTI.GOV)

de la Rue du Can, Stephane; Pudleiner, David; Jones, David

Like many countries in Sub-Saharan Africa, Uganda has focused its energy sector investments largely on increasing energy access by increasing energy supply. The links between energy efficiency and energy access, the importance of energy efficiency in new energy supply, and the multiple benefits of energy efficiency for the level and quality of energy available, have been largely overlooked. Implementing energy efficiency in parallel with expanding both the electricity grid and new clean energy generation reduces electricity demand and helps optimize the power supply so that it can serve more customers reliably at minimum cost. Ensuring efficient appliances are incorporated intomore » energy access efforts provides improved energy services to customers. Energy efficiency is an important contributor to access to modern energy. This Energy Efficiency Roadmap for Uganda (Roadmap) is a response to the important role that electrical energy efficiency can play in meeting Uganda’s energy goals. Power Africa and the United Nations Sustainable Energy for All (SEforALL) initiatives collaborated with more than 24 stakeholders in Uganda to develop this document. The document estimates that if the most efficient technologies on the market were adopted, 2,224 gigawatt hours could be saved in 2030 across all sectors, representing 31% of the projected load. This translates into 341 megawatts of peak demand reductions, energy access to an additional 6 million rural customers and reduction of carbon dioxide emissions by 10.6 million tonnes in 2030. The Roadmap also finds that 91% of this technical potential is cost-effective, and 47% is achievable under conservative assumptions. The Roadmap prioritizes recommendations for implementing energy efficiency and maximizing benefits to meet the goals and priorities established in Uganda’s 2015 SEforALL Action Agenda. One important step is to create and increase demand for efficiency through long-term enabling policies and financial incentives combined with development of technical expertise in the labor force to allow for the promotion of new business models, such as energy service companies. A combination of enabling policies, financial schemes, regulations, enforcement, and skill development are needed to open the energy efficiency market.« less

Materialism, Altruism, Environmental Values, Learning Strategies and Sustainable Claim on Purchase Intention of Energy Efficient Vehicle (EEV) - A Literature Review

NASA Astrophysics Data System (ADS)

Syakir Shukor, Muhamad; Sulaiman, Zuraidah; Chin, Thoo Ai; Zakuan, Norhayati; Merlinda Muharam, Farrah

2017-06-01

One of the toughest challenges in social marketing is behaviour intervention. Previous research have developed various models and theories to simultaneously examine behaviour changes and their effects. Due to resources scarcity and global warming, automakers have come out with an innovative idea of Energy Efficient Vehicle (EEV) which has been a great improvement in the automotive industry. This invention targets for behavioral change or behavioral adoption for consumers to adjust their preferences from conventional vehicle to EEV. High market growth in automotive industry have encouraged social marketers, policymakers, governments and academics to propose suitable intervention approach in motivating preferences toward EEV. This study will explore the causal model of Environmental Responsible Behaviour (ERB) in measuring the purchase intention of EEV in Malaysia. In specific, this study focuses on two types of EEV - hybrid car and fuel efficient car. This study will hopefully add onto the body of knowledge for value orientation that influences green behaviour. From the practical perspective, this study may provide insights in assisting the stakeholders and automotive industry players on promoting the pro-behaviour toward EEV.

Enhancing the thermoelectric performance of gamma-graphyne nanoribbons by introducing edge disorder.

PubMed

Cui, Xiao; Ouyang, Tao; Li, Jin; He, Chaoyu; Tang, Chao; Zhong, Jianxin

2018-03-07

Structure disorder especially edge disorder is unavoidable during the fabrication of nanomaterials. In this paper, using the non-equilibrium Green's function method, we investigate the influence of edge disorder on the thermoelectric performance of gamma(γ)-graphyne nanoribbons (GYNRs). Our results show that the high Seebeck coefficient in pristine γ-GYNR could still be preserved although edge disorder is introduced into the structure. Meanwhile, in these edge-disordered nanoribbons the suppression of thermal conductance including electronic and phononic contributions outweighs the reduction of electronic conductance. These two positive effects combine together, and finally boost the thermoelectric conversion efficiency of γ-GYNRs. The thermoelectric figure of merit ZT in the edge-disordered γ-GYNRs (the length and width are about 55.68 and 1.41 nm) could approach 2.5 at room temperature, and can even reach as high as 4.0 at 700 K, which is comparable to the efficiency of conventional energy conversion methods. The findings in this paper indicate that the edge-disordered γ-GYNRs are a promising candidate for efficient thermoelectric energy conversion and thermal management of nanodevices.

Analysis of novel low specific speed pump designs

NASA Astrophysics Data System (ADS)

Klas, R.; Pochylý, F.; Rudolf, P.

2014-03-01

Centrifugal pumps with very low specific speed present significant design challenges. Narrow blade channels, large surface area of hub and shroud discs relative to the blade area, and the presence of significant of blade channel vortices are typical features linked with the difficulty to achieve head and efficiency requirements for such designs. This paper presents an investigation of two novel designs of very low specific speed impellers: impeller having blades with very thick trailing edges and impeller with thick trailing edges and recirculating channels, which are bored along the impeller circumference. Numerical simulations and experimental measurements were used to study the flow dynamics of those new designs. It was shown that thick trailing edges suppress local eddies in the blade channels and decrease energy dissipation due to excessive swirling. Furthermore the recirculating channels will increase the circumferential velocity component on impeller outlet thus increasing the specific energy, albeit adversely affecting the hydraulic efficiency. Analysis of the energy dissipation in the volute showed that the number of the recirculating channels, their geometry and location, all have significant impact on the magnitude of dissipated energy and its distribution which in turn influences the shape of the head curve and the stability of the pump operation. Energy dissipation within whole pump interior (blade channels, volute, rotor- stator gaps) was also studied.

A Framework to Improve Energy Efficient Behaviour at Home through Activity and Context Monitoring

PubMed Central

García, Óscar; Alonso, Ricardo S.; Corchado, Juan M.

2017-01-01

Real-time Localization Systems have been postulated as one of the most appropriated technologies for the development of applications that provide customized services. These systems provide us with the ability to locate and trace users and, among other features, they help identify behavioural patterns and habits. Moreover, the implementation of policies that will foster energy saving in homes is a complex task that involves the use of this type of systems. Although there are multiple proposals in this area, the implementation of frameworks that combine technologies and use Social Computing to influence user behaviour have not yet reached any significant savings in terms of energy. In this work, the CAFCLA framework (Context-Aware Framework for Collaborative Learning Applications) is used to develop a recommendation system for home users. The proposed system integrates a Real-Time Localization System and Wireless Sensor Networks, making it possible to develop applications that work under the umbrella of Social Computing. The implementation of an experimental use case aided efficient energy use, achieving savings of 17%. Moreover, the conducted case study pointed to the possibility of attaining good energy consumption habits in the long term. This can be done thanks to the system’s real time and historical localization, tracking and contextual data, based on which customized recommendations are generated. PMID:28758987

Towards designing polymers for photovoltaic applications: A DFT and experimental study of polyazomethines with various chemical structures

NASA Astrophysics Data System (ADS)

Wojtkiewicz, Jacek; Iwan, Agnieszka; Pilch, Marek; Boharewicz, Bartosz; Wójcik, Kamil; Tazbir, Igor; Kaminska, Maria

2017-06-01

Theoretical studies of polyazomethines (PAZs) with various chemical structures designated for photovoltaic applications are presented. PAZ energy levels and optical properties were calculated within density-functional theory (DFT and TDDFT) framework for 28 oligomers (monomer, dimer and trimer) of PAZs. The correlations between chemical structure of PAZ and location of its highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels were examined. It turned out that the presence of triaminophenylene, dimethoxydiphenylene and fluorine group raises the orbital energies. As a consequence, it is a factor which improves the photovoltaic efficiency of solar cell built on the base of the corresponding PAZ and [6,6]-phenyl C61 butyric acid methyl ester (PCBM). On the contrary, quinone, 1,3,5-triazine and perfluorophenylene groups lower orbital energies and have negative influence on the photovoltaic efficiency. Moreover, calculations for methyl, ethyl and butyl analogs of P3HT as well as polythiophenes were performed and compared with the results obtained for PAZs. In addition experimental data are presented, which cover optical, electrochemical and electrical transport properties of the studied PAZs, allowing to determine HOMO and LUMO energies of the polymers and their conductivity. Finally, comparison between calculated and experimental results were made and discussed.

77 FR 31756 - Energy Conservation Program: Alternative Efficiency Determination Methods and Alternative Rating...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-30

...-AC46 Energy Conservation Program: Alternative Efficiency Determination Methods and Alternative Rating Methods: Public Meeting AGENCY: Office of Energy Efficiency and Renewable Energy, Department of Energy... regulations authorizing the use of alternative methods of determining energy efficiency or energy consumption...

Evaluation of Different Holder Devices for Freeze-Drying in Dual-Chamber Cartridges With a Focus on Energy Transfer.

PubMed

Korpus, Christoph; Friess, Wolfgang

2017-04-01

For freeze-drying in dual-chamber cartridges, a holder device to enable handling and safe positioning in the freeze-dryer is necessary. The aim of this study was to analyze 4 different types of holder devices and to define the best system based on energy transfer. The main criteria were drying homogeneity, ability to minimize the influence of atypical radiation on product temperatures, and heat transfer effectiveness. The shell holder reduced the influence of atypical radiation by almost 60% compared to a block system and yielded the most homogenous sublimation rates. Besides the most efficient heat transfer with values of 1.58E-4 ± 2.06E-6 cal/(s*cm 2 *K) at 60 mTorr to 3.63E-4 ± 1.85E-5 cal/(s*cm 2 *K) at 200 mTorr for K tot , reaction times to shelf temperature changes were up to 4 times shorter compared to the other holder systems and even faster than for vials. The flexible holder provided a comparable shielding against atypical radiation as the shell but introduced a third barrier against energy transfer. Block and guardrail holder were the least efficient system tested. Hence, the shell holder provided the best radiation shielding, enhanced the transferability of the results to a larger scale, and improved the homogeneity between the dual-chamber cartridges. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Efficient cold outflows driven by cosmic rays in high-redshift galaxies and their global effects on the IGM

NASA Astrophysics Data System (ADS)

Samui, Saumyadip; Subramanian, Kandaswamy; Srianand, Raghunathan

2018-05-01

We present semi-analytical models of galactic outflows in high-redshift galaxies driven by both hot thermal gas and non-thermal cosmic rays. Thermal pressure alone may not sustain a large-scale outflow in low-mass galaxies (i.e. M ˜ 108 M⊙), in the presence of supernovae feedback with large mass loading. We show that inclusion of cosmic ray pressure allows outflow solutions even in these galaxies. In massive galaxies for the same energy efficiency, cosmic ray-driven winds can propagate to larger distances compared to pure thermally driven winds. On an average gas in the cosmic ray-driven winds has a lower temperature which could aid detecting it through absorption lines in the spectra of background sources. Using our constrained semi-analytical models of galaxy formation (that explains the observed ultraviolet luminosity functions of galaxies), we study the influence of cosmic ray-driven winds on the properties of the intergalactic medium (IGM) at different redshifts. In particular, we study the volume filling factor, average metallicity, cosmic ray and magnetic field energy densities for models invoking atomic cooled and molecular cooled haloes. We show that the cosmic rays in the IGM could have enough energy that can be transferred to the thermal gas in presence of magnetic fields to influence the thermal history of the IGM. The significant volume filling and resulting strength of IGM magnetic fields can also account for recent γ-ray observations of blazars.

Energy capture and storage in asymmetrically multistable modular structures inspired by skeletal muscle

NASA Astrophysics Data System (ADS)

Kidambi, Narayanan; Harne, Ryan L.; Wang, K. W.

2017-08-01

The remarkable versatility and adaptability of skeletal muscle that arises from the assembly of its nanoscale cross-bridges into micro-scale assemblies known as sarcomeres provides great inspiration for the development of advanced adaptive structures and material systems. Motivated by the capability of cross-bridges to capture elastic strain energy to improve the energetic efficiency of sudden movements and repeated motions, and by models of cross-bridge power stroke motions and sarcomere contractile behaviors that incorporate asymmetric, bistable potential energy landscapes, this research develops and studies modular mechanical structures that trap and store energy in higher-energy configurations. Modules exhibiting tailorable asymmetric bistability are first designed and fabricated, revealing how geometric parameters influence the asymmetry of the resulting double-well energy landscapes. These experimentally-observed characteristics are then investigated with numerical and analytical methods to characterize the dynamics of asymmetrically bistable modules. The assembly of such modules into greater structures generates complex, multi-well energy landscapes with stable system configurations exhibiting different quantities of stored elastic potential energy. Dynamic analyses illustrate the ability of these structures to capture a portion of the initial kinetic energy due to impulsive excitations as recoverable strain potential energy, and reveal how stiffness parameters, damping, and the presence of thermal noise in micro- and nano-scale applications influence energy capture behaviors. The insights gained could foster the development of advanced structural/material systems inspired by skeletal muscle, including actuators that effectively capture, store, and release energy, as well as adaptive, robust, and reusable armors and protective devices.

Energy efficiency of mobile soft robots.

PubMed

Shui, Langquan; Zhu, Liangliang; Yang, Zhe; Liu, Yilun; Chen, Xi

2017-11-15

The performance of mobile soft robots is usually characterized by their locomotion/velocity efficiency, whereas the energy efficiency is a more intrinsic and fundamental criterion for the performance evaluation of independent or integrated soft robots. In this work, a general framework is established to evaluate the energy efficiency of mobile soft robots by considering the efficiency of the energy source, actuator and locomotion, and some insights for improving the efficiency of soft robotic systems are presented. Proposed as the ratio of the desired locomotion kinetic energy to the input mechanical energy, the energy efficiency of locomotion is found to play a critical role in determining the overall energy efficiency of soft robots. Four key factors related to the locomotion energy efficiency are identified, that is, the locomotion modes, material properties, geometric sizes, and actuation states. It is found that the energy efficiency of most mobile soft robots reported in the literature is surprisingly low (mostly below 0.1%), due to the inefficient mechanical energy that essentially does not contribute to the desired locomotion. A comparison of the locomotion energy efficiency for several representative locomotion modes in the literature is presented, showing a descending ranking as: jumping ≫ fish-like swimming > snake-like slithering > rolling > rising/turning over > inchworm-like inching > quadruped gait > earthworm-like squirming. Besides, considering the same locomotion mode, soft robots with lower stiffness, higher density and larger size tend to have higher locomotion energy efficiency. Moreover, a periodic pulse actuation instead of a continuous actuation mode may significantly reduce the input mechanical energy, thus improving the locomotion energy efficiency, especially when the pulse actuation matches the resonant states of the soft robots. The results presented herein indicate a large and necessary space for improving the locomotion energy efficiency, which is of practical significance for the future development and application of soft robots.

Tidal energy extraction: renewable, sustainable and predictable.

PubMed

Nicholls-Lee, R F; Turnock, S R

2008-01-01

The tidal flow of sea water induced by planetary motion is a potential source of energy if suitable systems can be designed and operated in a cost-effective manner This paper examines the physical origins of the tides and how the local currents are influenced by the depth of the seabed and presence of land mass and associated coastal features. The available methods of extracting energy from tidal movement are classified into devices that store and release potential energy and those that capture kinetic energy directly. A survey is made of candidate designs and, for the most promising, the likely efficiency of energy conversion and methods of installing them are considered. Overall, the need to reduce CO2 emissions, a likely continued rise in fossil fuel cost will result in a significantly increased use of tidal energy. What is still required, especially for kinetic energy devices, is a much greater understanding of how they can be designed to withstand long-term immersion in the marine environment.

77 FR 5001 - Publication of the Petition for Waiver From Empire Comfort Systems From the Department of Energy...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-01

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy [Case No. VHE-001... Heating Equipment Test Procedure AGENCY: Office of Energy Efficiency and Renewable Energy, Department of... Energy Efficiency, Energy Efficiency and Renewable Energy. [FR Doc. 2012-2181 Filed 1-31-12; 8:45 am...

Influence of peak power in ablation rate of dental hard tissues: mathematical model

NASA Astrophysics Data System (ADS)

Colojoara, Carmen; Gabay, Shimon; van der Meulen, Freerk W.; van Gemert, Martin J. C.

1996-12-01

Pulsed Er:YAG and CO2 lasers should be suitable instruments for dentin and enamel ablation because both tissues have absorption peaks for radiation at 2.9 and 9.6 micrometers wavelengths. This is the context of our research that emphasizes the way in which the diameter and the depth of the crater made in enamel and dentin with the laser Er:YAG and CO2 is influenced in quantity and quality. Freshly extracted human third molar were used for this experiment. The laser source is Er:YAG Kavo Key dental model 1240 and CO2 Laser Sonics LS 860. The dimensions of the obtained craters were measured using the optical microscopy method. The obtained results were modelled experimentally with programs: GRAPHER and STATGRAPHICS. After the mathematical processing to the results what we obtain is relevant regarding the influence of the key parameters in the efficiency of the ablation according to the type of laser. On the whole, from our research results that both lasers ablate efficiently the dentin when the laser energy is between 200 and 300 mJ.

Collaborative Emission Reduction Model Based on Multi-Objective Optimization for Greenhouse Gases and Air Pollutants.

PubMed

Meng, Qing-chun; Rong, Xiao-xia; Zhang, Yi-min; Wan, Xiao-le; Liu, Yuan-yuan; Wang, Yu-zhi

2016-01-01

CO2 emission influences not only global climate change but also international economic and political situations. Thus, reducing the emission of CO2, a major greenhouse gas, has become a major issue in China and around the world as regards preserving the environmental ecology. Energy consumption from coal, oil, and natural gas is primarily responsible for the production of greenhouse gases and air pollutants such as SO2 and NOX, which are the main air pollutants in China. In this study, a mathematical multi-objective optimization method was adopted to analyze the collaborative emission reduction of three kinds of gases on the basis of their common restraints in different ways of energy consumption to develop an economic, clean, and efficient scheme for energy distribution. The first part introduces the background research, the collaborative emission reduction for three kinds of gases, the multi-objective optimization, the main mathematical modeling, and the optimization method. The second part discusses the four mathematical tools utilized in this study, which include the Granger causality test to analyze the causality between air quality and pollutant emission, a function analysis to determine the quantitative relation between energy consumption and pollutant emission, a multi-objective optimization to set up the collaborative optimization model that considers energy consumption, and an optimality condition analysis for the multi-objective optimization model to design the optimal-pole algorithm and obtain an efficient collaborative reduction scheme. In the empirical analysis, the data of pollutant emission and final consumption of energies of Tianjin in 1996-2012 was employed to verify the effectiveness of the model and analyze the efficient solution and the corresponding dominant set. In the last part, several suggestions for collaborative reduction are recommended and the drawn conclusions are stated.

Collaborative Emission Reduction Model Based on Multi-Objective Optimization for Greenhouse Gases and Air Pollutants

PubMed Central

Zhang, Yi-min; Wan, Xiao-le; Liu, Yuan-yuan; Wang, Yu-zhi

2016-01-01

CO2 emission influences not only global climate change but also international economic and political situations. Thus, reducing the emission of CO2, a major greenhouse gas, has become a major issue in China and around the world as regards preserving the environmental ecology. Energy consumption from coal, oil, and natural gas is primarily responsible for the production of greenhouse gases and air pollutants such as SO2 and NOX, which are the main air pollutants in China. In this study, a mathematical multi-objective optimization method was adopted to analyze the collaborative emission reduction of three kinds of gases on the basis of their common restraints in different ways of energy consumption to develop an economic, clean, and efficient scheme for energy distribution. The first part introduces the background research, the collaborative emission reduction for three kinds of gases, the multi-objective optimization, the main mathematical modeling, and the optimization method. The second part discusses the four mathematical tools utilized in this study, which include the Granger causality test to analyze the causality between air quality and pollutant emission, a function analysis to determine the quantitative relation between energy consumption and pollutant emission, a multi-objective optimization to set up the collaborative optimization model that considers energy consumption, and an optimality condition analysis for the multi-objective optimization model to design the optimal-pole algorithm and obtain an efficient collaborative reduction scheme. In the empirical analysis, the data of pollutant emission and final consumption of energies of Tianjin in 1996–2012 was employed to verify the effectiveness of the model and analyze the efficient solution and the corresponding dominant set. In the last part, several suggestions for collaborative reduction are recommended and the drawn conclusions are stated. PMID:27010658

10 CFR 431.444 - Test procedures for the measurement of energy efficiency.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 3 2011-01-01 2011-01-01 false Test procedures for the measurement of energy efficiency. 431.444 Section 431.444 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR... procedures for the measurement of energy efficiency. (a) Scope. Pursuant to section 346(b)(1) of EPCA, this...

10 CFR 431.444 - Test procedures for the measurement of energy efficiency.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Test procedures for the measurement of energy efficiency. 431.444 Section 431.444 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR... procedures for the measurement of energy efficiency. (a) Scope. Pursuant to section 346(b)(1) of EPCA, this...

75 FR 31323 - Energy Efficiency Program: Energy Conservation Standards Furnace Fans: Public Meeting and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-03

.... EERE-2010-BT-STD-0011] RIN 1904-AC22 Energy Efficiency Program: Energy Conservation Standards Furnace Fans: Public Meeting and Availability of the Framework Document AGENCY: Office of Energy Efficiency and... Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies, EE-2J, 1000 Independence...

10 CFR 433.7 - Water used to achieve energy efficiency. [Reserved

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Water used to achieve energy efficiency. [Reserved] 433.7 Section 433.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL BUILDINGS § 433.7 Water used to achieve energy efficiency...

10 CFR 433.7 - Water used to achieve energy efficiency. [Reserved

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Water used to achieve energy efficiency. [Reserved] 433.7 Section 433.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL BUILDINGS § 433.7 Water used to achieve energy efficiency...

Data Center Energy Efficiency Standards in India: Preliminary Findings from Global Practices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raje, Sanyukta; Maan, Hermant; Ganguly, Suprotim

Global data center energy consumption is growing rapidly. In India, information technology industry growth, fossil-fuel generation, and rising energy prices add significant operational costs and carbon emissions from energy-intensive data centers. Adoption of energy-efficient practices can improve the global competitiveness and sustainability of data centers in India. Previous studies have concluded that advancement of energy efficiency standards through policy and regulatory mechanisms is the fastest path to accelerate the adoption of energy-efficient practices in the Indian data centers. In this study, we reviewed data center energy efficiency practices in the United States, Europe, and Asia. Using evaluation metrics, we identifiedmore » an initial set of energy efficiency standards applicable to the Indian context using the existing policy mechanisms. These preliminary findings support next steps to recommend energy efficiency standards and inform policy makers on strategies to adopt energy-efficient technologies and practices in Indian data centers.« less

Dynamics of CO2 scattering off a perfluorinated self-assembled monolayer. Influence of the incident collision energy, mass effects, and use of different surface models.

PubMed

Nogueira, Juan J; Vázquez, Saulo A; Mazyar, Oleg A; Hase, William L; Perkins, Bradford G; Nesbitt, David J; Martínez-Núñez, Emilio

2009-04-23

The dynamics of collisions of CO2 with a perfluorinated alkanethiol self-assembled monolayer (F-SAM) on gold were investigated by classical trajectory calculations using explicit atom (EA) and united atom (UA) models to represent the F-SAM surface. The CO2 molecule was directed perpendicularly to the surface at initial collision energies of 1.6, 4.7, 7.7, and 10.6 kcal/mol. Rotational distributions of the scattered CO2 molecules are in agreement with experimental distributions determined for collisions of CO2 with liquid surfaces of perfluoropolyether. The agreement is especially good for the EA model. The role of the mass in the efficiency of the energy transfer was investigated in separate simulations in which the mass of the F atoms was replaced by either that of hydrogen or chlorine, while keeping the potential energy function unchanged. The calculations predict the observed trend that less energy is transferred to the surface as the mass of the alkyl chains increases. Significant discrepancies were found between results obtained with the EA and UA models. The UA surface leads to an enhancement of the energy transfer efficiency in comparison with the EA surface. The reason for this is in the softer structure of the UA surface, which facilitates transfer from translation to interchain vibrational modes.

Competition--supporting or preventing an increased use of bioenergy?

PubMed

Thrän, Daniela; Kaltschmitt, Martin

2007-12-01

The intensified use of biomass as an energy source is an often-repeated goal of the German and European climate protection policy. Therefore, framework conditions have been created in recent years, which allow for a wider use of biomass within the energy system especially for a provision of electricity and fuels. Due to this policy, Germany, for example, has emerged as the leading producer of biogas from energy crops and fatty methyl ester (FAME) in Europe. However, due to the high energy price level, the use of biomass for heating purposes and as a renewable raw material have increased at the same time. To supply the obviously increased demand for biomass or biobased energy carriers cost efficiently, nationwide and to some extend even global markets are under development at present. As the demand for biomass is expected to continue to increase strongly, it is feared that an increasing competition with the use for food and fodder as well as a raw material might occur in the years to come. Against this background we have analyzed the competitions that can be expected, and the influence that they may have on the further expansion of the use of biomass for energy production. Experiences from Germany are provided exemplarily. Based on this, it is concluded that measures need to be taken to support an efficient and sustainable use of bioenergy in the future.

Infrared Dielectric Screening Determines the Low Exciton Binding Energy of Metal-Halide Perovskites.

PubMed

Umari, Paolo; Mosconi, Edoardo; De Angelis, Filippo

2018-02-01

The performance of lead-halide perovskites in optoelectronic devices is due to a unique combination of factors, including highly efficient generation, transport, and collection of photogenerated charge carriers. The mechanism behind efficient charge generation in lead-halide perovskites is still largely unknown. Here, we investigate the factors that influence the exciton binding energy (E b ) in a series of metal-halide perovskites using accurate first-principles calculations based on solution of the Bethe-Salpeter equation, coupled to ab initio molecular dynamics simulations. We find that E b is strongly modulated by screening from low-energy phonons, which account for a factor ∼2 E b reduction, while dynamic disorder and rotational motion of the organic cations play a minor role. We calculate E b = 15 meV for MAPbI 3 , in excellent agreement with recent experimental estimates. We then explore how different material combinations (e.g., replacing Pb → Pb:Sn→ Sn; and MA → FA → Cs) may lead to different E b values and highlight the mechanisms underlying E b tuning.

On the Stability of NaO2 in Na-O2 Batteries.

PubMed

Liu, Chenjuan; Carboni, Marco; Brant, William R; Pan, Ruijun; Hedman, Jonas; Zhu, Jiefang; Gustafsson, Torbjörn; Younesi, Reza

2018-04-25

Na-O 2 batteries are regarded as promising candidates for energy storage. They have higher energy efficiency, rate capability, and chemical reversibility than Li-O 2 batteries; in addition, sodium is cheaper and more abundant compared to lithium. However, inconsistent observations and instability of discharge products have inhibited the understanding of the working mechanism of this technology. In this work, we have investigated a number of factors that influence the stability of the discharge products. By means of in operando powder X-ray diffraction study, the influence of oxygen, sodium anode, salt, solvent, and carbon cathode were investigated. The Na metal anode and an ether-based solvent are the main factors that lead to the instability and decomposition of NaO 2 in the cell environment. This fundamental insight brings new information on the working mechanism of Na-O 2 batteries.

Investigation on the influence of electrode geometry on characteristics of coaxial dielectric barrier discharge reactor driven by an oscillating microsecond pulsed power supply

NASA Astrophysics Data System (ADS)

Miao, Chuanrun; Liu, Feng; Wang, Qian; Cai, Meiling; Fang, Zhi

2018-03-01

In this paper, an oscillating microsecond pulsed power supply with rise time of several tens of nanosecond (ns) is used to excite a coaxial DBD with double layer dielectric barriers. The effects of various electrode geometries by changing the size of inner quartz tube (different electrode gaps) on the discharge uniformity, power deposition, energy efficiency, and operation temperature are investigated by electrical, optical, and temperature diagnostics. The electrical parameters of the coaxial DBD are obtained from the measured applied voltage and current using an equivalent electrical model. The energy efficiency and the power deposition in air gap of coaxial DBD with various electrode geometries are also obtained with the obtained electrical parameters, and the heat loss and operation temperature are analyzed by a heat conduction model. It is found that at the same applied voltage, with the increasing of the air gap, the discharge uniformity becomes worse and the discharge power deposition and the energy efficiency decrease. At 2.5 mm air gap and 24 kV applied voltage, the energy efficiency of the coaxial DBD reaches the maximum value of 68.4%, and the power deposition in air gap is 23.6 W and the discharge uniformity is the best at this case. The corresponding operation temperature of the coaxial DBD reaches 64.3 °C after 900 s operation and the temperature of the inner dielectric barrier is 114.4 °C under thermal balance. The experimental results provide important experimental references and are important to optimize the design and the performance of coaxial DBD reactor.

Hydrogen production by sodium borohydride in NaOH aqueous solution

NASA Astrophysics Data System (ADS)

Wang, Q.; Zhang, L. F.; Zhao, Z. G.

2018-01-01

The kinetics of hydrolysis reaction of NaBH4 in NaOH aqueous solution is studied. The influence of pH of the NaOH aqueous solution on the rate of hydrogen production and the hydrogen production efficiency are studied for the hydrolysis reaction of NaBH4. The results show that the activation energy of hydrolysis reaction of NaBH4 increased with the increase of the initial pH of NaOH aqueous solution.With the increasing of the initial pH of NaOH aqueous solution, the rate of hydrogen production and hydrogen production efficiency of NaBH4 hydrolysis decrease.

Magnetic Field-Controlled Lithium Polysulfide Semiliquid Battery with Ferrofluidic Properties.

PubMed

Li, Weiyang; Liang, Zheng; Lu, Zhenda; Tao, Xinyong; Liu, Kai; Yao, Hongbin; Cui, Yi

2015-11-11

Large-scale energy storage systems are of critical importance for electric grids, especially with the rapid increasing deployment of intermittent renewable energy sources such as wind and solar. New cost-effective systems that can deliver high energy density and efficiency for such storage often involve the flow of redox molecules and particles. Enhancing the mass and electron transport is critical for efficient battery operation in these systems. Herein, we report the design and characterization of a novel proof-of-concept magnetic field-controlled flow battery using lithium metal-polysulfide semiliquid battery as an example. A biphasic magnetic solution containing lithium polysulfide and magnetic nanoparticles is used as catholyte, and lithium metal is used as anode. The catholyte is composed of two phases of polysulfide with different concentrations, in which most of the polysulfide molecules and the superparamagnetic iron oxide nanoparticles can be extracted together to form a high-concentration polysulfide phase, in close contact with the current collector under the influence of applied magnetic field. This unique feature can help to maximize the utilization of the polysulfide and minimize the polysulfide shuttle effect, contributing to enhanced energy density and Coulombic efficiency. Additionally, owing to the effect of the superparamagnetic nanoparticles, the concentrated polysulfide phase shows the behavior of a ferrofluid that is flowable with the control of magnetic field, which can be used for a hybrid flow battery without the employment of any pumps. Our innovative design provides new insight for a broad range of flow battery chemistries and systems.

75 FR 32177 - Energy Efficiency Program for Consumer Products: Commonwealth of Massachusetts Petition for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-07

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy [Docket Number EERE-BT-PET-0024] Energy Efficiency Program for Consumer Products: Commonwealth of Massachusetts Petition for Exemption From Federal Preemption of Massachusetts' Energy Efficiency Standard for Residential Non...

10 CFR 431.383 - Enforcement process for electric motors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 431.383 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN... not be in compliance with the applicable energy efficiency standard, or upon undertaking to ascertain... its labeled efficiency, or the applicable energy efficiency standard, shall be based on the testing...

Thermodynamic analysis of fuels in gas phase: ethanol, gasoline and ethanol - gasoline predicted by DFT method.

PubMed

Neto, A F G; Lopes, F S; Carvalho, E V; Huda, M N; Neto, A M J C; Machado, N T

2015-10-01

This paper presents a theoretical study using density functional theory to calculate thermodynamics properties of major molecules compounds at gas phase of fuels like gasoline, ethanol, and gasoline-ethanol mixture in thermal equilibrium on temperature range up to 1500 K. We simulated a composition of gasoline mixture with ethanol for a thorough study of thermal energy, enthalpy, Gibbs free energy, entropy, heat capacity at constant pressure with respect to temperature in order to study the influence caused by ethanol as an additive to gasoline. We used semi-empirical computational methods as well in order to know the efficiency of other methods to simulate fuels through this methodology. In addition, the ethanol influence through the changes in percentage fractions of chemical energy released in combustion reaction and the variations on thermal properties for autoignition temperatures of fuels was analyzed. We verified how ethanol reduces the chemical energy released by gasoline combustion and how at low temperatures the gas phase fuels in thermal equilibrium have similar thermodynamic behavior. Theoretical results were compared with experimental data, when available, and showed agreement. Graphical Abstract Thermodynamic analysis of fuels in gas phase.

Micro-gun based on laser pulse propulsion.

PubMed

Yu, Haichao; Li, Hanyang; Cui, Lugui; Liu, Shuangqiang; Yang, Jun

2017-11-24

This paper proposes a novel "micro-gun" structure for laser pulse propulsion. The "micro-bullets" (glass microspheres) are irradiated by a laser pulse with a 10 ns duration in a dynamic process. Experimental parameters such as the microsphere diameter and the laser pulse energy are varied to investigate their influence on laser pulse propulsion. The energy field and spatial intensity distribution in the capillary tube were simulated using a three-dimensional finite-difference time-domain method. The experimental results demonstrate that the propulsion efficiency is dependent on the laser pulse energy and the microsphere size. The propulsion modes and sources of the propelling force were confirmed through direct observation and theoretical calculation. Waves also generated by light-pressure and thermal expansions assisted the propulsion.

Technical Analysis Feasibility Study on Smart Microgrid System in Sekolah Tinggi Teknik PLN

NASA Astrophysics Data System (ADS)

Suyanto, Heri

2018-02-01

Nowadays application of new and renewable energy as main resource of power plant has greatly increased. High penetration of renewable energy into the grid will influence the quality and reliability of the electricity system, due to the intermittent characteristic of new and renewable energy resources. Smart grid or microgrid technology has the ability to deal with this intermittent characteristic especially if these renewable energy resources integrated to grid in large scale, so it can improve the reliability and efficiency of the grid. We plan to implement smart microgrid system at Sekolah Tinggi Teknik PLN as a pilot project. Before the pilot project start, the feasibility study must be conducted. In this feasibility study, the renewable energy resources and load characteristic at the site will be measured. Then the technical aspect of this feasibility study will be analyzed. This paper explains that analysis of ths feasibility study.

Energy economy in the actomyosin interaction: lessons from simple models.

PubMed

Lehman, Steven L

2010-01-01

The energy economy of the actomyosin interaction in skeletal muscle is both scientifically fascinating and practically important. This chapter demonstrates how simple cross-bridge models have guided research regarding the energy economy of skeletal muscle. Parameter variation on a very simple two-state strain-dependent model shows that early events in the actomyosin interaction strongly influence energy efficiency, and late events determine maximum shortening velocity. Addition of a weakly-bound state preceding force production allows weak coupling of cross-bridge mechanics and ATP turnover, so that a simple three-state model can simulate the velocity-dependence of ATP turnover. Consideration of the limitations of this model leads to a review of recent evidence regarding the relationship between ligand binding states, conformational states, and macromolecular structures of myosin cross-bridges. Investigation of the fine structure of the actomyosin interaction during the working stroke continues to inform fundamental research regarding the energy economy of striated muscle.

Concerning the sound insulation of building elements made up of light concretes. [acoustic absorption efficiency calculations

NASA Technical Reports Server (NTRS)

Giurgiu, I. I.

1974-01-01

The sound insulating capacity of building elements made up of light concretes is considered. Analyzing differentially the behavior of light concrete building elements under the influence of incident acoustic energy and on the basis of experimental measurements, coefficients of correction are introduced into the basic formulas for calculating the sound insulating capacity for the 100-3,2000 Hz frequency band.

X-Ray Radiography Measurements of the Thermal Energy in Spark Ignition Plasma at Variable Ambient Conditions

DOE PAGES

Matusik, Katarzyna E.; Duke, Daniel J.; Kastengren, Alan L.; ...

2017-04-09

The sparking behavior in an internal combustion engine affects the fuel efficiency, engine-out emissions, and general drivability of a vehicle. As emissions regulations become progressively stringent, combustion strategies, including exhaust gas recirculation (EGR), lean-burn, and turbocharging are receiving increasing attention as models of higher efficiency advanced combustion engines with reduced emissions levels. Because these new strategies affect the working environment of the spark plug, ongoing research strives to understand the influence of external factors on the spark ignition process. Due to the short time and length scales involved and the harsh environment, experimental quantification of the deposited energy from themore » sparking event is difficult to obtain. We present the results of x-ray radiography measurements of spark ignition plasma generated by a conventional spark plug. Our measurements were performed at the 7-BM beamline of the Advanced Photon Source at Argonne National Laboratory. The synchrotron x-ray source enables time-resolved measurements of the density change due to glow discharge in the spark gap with 153 ns temporal and 5 μm spatial resolutions. We also explore the effects of charging time, EGR-relevant gas compositions, and gas pressure on the sparking behavior. We also quantify the influence of the measurement technique on the obtained results.« less

Did Adult Diurnal Activity Influence the Evolution of Wing Morphology in Opoptera Butterflies?

PubMed

Penz, C M; Heine, K B

2016-02-01

The butterfly genus Opoptera includes eight species, three of which have diurnal habits while the others are crepuscular (the usual activity period for members of the tribe Brassolini). Although never measured in the field, it is presumed that diurnal Opoptera species potentially spend more time flying than their crepuscular relatives. If a shift to diurnal habits potentially leads to a higher level of activity and energy expenditure during flight, then selection should operate on increased aerodynamic and energetic efficiency, leading to changes in wing shape. Accordingly, we ask whether diurnal habits have influenced the evolution of wing morphology in Opoptera. Using phylogenetically independent contrasts and Wilcoxon rank sum tests, we confirmed our expectation that the wings of diurnal species have higher aspect ratios (ARs) and lower wing centroids (WCs) than crepuscular congeners. These wing shape characteristics are known to promote energy efficiency during flight. Three Opoptera wing morphotypes established a priori significantly differed in AR and WC values. The crepuscular, cloud forest dweller Opoptera staudingeri (Godman & Salvin) was exceptional in having an extended forewing tip and the highest AR and lowest WC within Opoptera, possibly to facilitate flight in a cooler environment. Our study is the first to investigate how butterfly wing morphology might evolve as a response to a behavioral shift in adult time of activity.

76 FR 25683 - State Energy Advisory Board (STEAB); Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-05

... DEPARTMENT OF ENERGY Energy Efficiency and Renewable Energy State Energy Advisory Board (STEAB); Meeting AGENCY: Energy Efficiency and Renewable Energy, Department of Energy. ACTION: Notice of Open... Energy Efficiency and Renewable Energy, 1000 Independence Avenue, SW., Washington DC 20585; or e-mail...

Energy Efficiency and Conservation Attitudes: An Exploration of a Landscape of Choices

NASA Astrophysics Data System (ADS)

McClaren, Mersiha Spahic

This study explored energy-related attitudes and energy-saving behaviors that are no- or low-cost and relatively simple to perform. This study relied on two data sources: a longitudinal but cross-sectional survey of 4,102 U.S. residents (five biennial waves of this survey were conducted from 2002 to 2010) and a 2010 cross-sectional survey of 2,000 California residents. These two surveys contained data on two no- and low-cost behaviors: changing thermostat setting to save energy (no-cost behavior) and CFL installation behavior (low-cost behavior). In terms of attitudes, two attitudinal measures emerged from these data following a Cronbach's alpha and Confirmatory Factor Analysis (CFA): the pro-environmental attitude and concern for the energy use in the U.S. society. These two attitudes, along with other socio-demographic and external factors (home ownership, weather, price of energy, etc.), were examined to assess whether attitude-behavior relationships persisted over time, were more prominent across certain groups, or were constrained by income or other socio-demographic factors. Three theoretical viewpoints of how attitudes may relate to behavior guided the analysis on how attitudes and contextual factors may inter-relate either directly or through a moderator variable to affect thermostat-setting and CFL installation behavior. Results from these analyses revealed four important patterns. First, a relationship between the pro-environmental attitude and the two behaviors (thermostat-setting and CFL installation behavior) was weak but persistent across time. Second, financial factors such as income moderated the pro-environmental attitude and CFL installation relationship, indicating that the pro-environmental attitude could influence the behavior in those situations where financial resources are sufficient to comfortably allow the consumer to participate. Third, this study documented that most people reported changing thermostat settings to save energy or having one or more CFLs in their homes. This finding suggests that organizations, policy makers, or energy efficiency program administrators may want to assess whether they should pursue these two behaviors further, since they appear to be very common in the U.S. population. Last, this study showed that thermostat-setting and CFL installation behavior have multi-factorial influences; many factors in addition to attitudes were significantly associated with these behaviors, and all these factors together explained no more than 16% of behavioral variance. This suggested that if energy-saving behaviors are a function of many different variables, of which none appear to be the "silver bullet" in explaining the behaviors (as noted in this study), then policy analysis should explore a broader number of causal pathways and entertain a wider range of interventions to influence consumers to save energy.

Efficiency of a hybrid-type plasma-assisted fuel reformation system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matveev, I.B.; Serbin, S.I.; Lux, S.M.

2008-12-15

The major advantages of a new plasma-assisted fuel reformation system are its cost effectiveness and technical efficiency. Applied Plasma Technologies has proposed its new highly efficient hybrid-type plasma-assisted system for organic fuel combustion and gasification. The system operates as a multimode multipurpose reactor in a wide range of plasma feedstock gases and turndown ratios. This system also has convenient and simultaneous feeding of several reagents in the reaction zone such as liquid fuels, coal, steam, and air. A special methodology has been developed for such a system in terms of heat balance evaluation and optimization. This methodology considers all existingmore » and possible energy streams, which could influence the system's efficiency. The developed hybrid-type plasma system could be suitable for combustion applications, mobile and autonomous small- to mid-size liquid fuel and coal gasification modules, hydrogen-rich gas generators, waste-processing facilities, and plasma chemical reactors.« less

A new method for evaluating radon and thoron alpha-activities per unit volume inside and outside various natural material samples by calculating SSNTD detection efficiencies for the emitted alpha-particles and measuring the resulting track densities.

PubMed

Misdaq, M A; Aitnouh, F; Khajmi, H; Ezzahery, H; Berrazzouk, S

2001-08-01

A Monte Carlo computer code for determining detection efficiencies of the CR-39 and LR-115 II solid-state nuclear track detectors (SSNTD) for alpha-particles emitted by the uranium and thorium series inside different natural material samples was developed. The influence of the alpha-particle initial energy on the SSNTD detection efficiencies was investigated. Radon (222Rn) and thoron (220Rn) alpha-activities per unit volume were evaluated inside and outside the natural material samples by exploiting data obtained for the detection efficiencies of the SSNTD utilized for the emitted alpha-particles, and measuring the resulting track densities. Results obtained were compared to those obtained by other methods. Radon emanation coefficients have been determined for some of the considered material samples.

76 FR 30143 - Agency Information Collection Extension

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-24

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy Agency Information..., Buy American Coordinator, Office of Energy Efficiency and Renewable Energy (EERE), Department of... Energy Efficiency and Renewable Energy (EERE), Department of Energy, 1000 Independence Avenue, SW...

[Research on carbon reduction potential of electric vehicles for low-carbon transportation and its influencing factors].

PubMed

Shi, Xiao-Qing; Li, Xiao-Nuo; Yang, Jian-Xin

2013-01-01

Transportation is the key industry of urban energy consumption and carbon emissions. The transformation of conventional gasoline vehicles to new energy vehicles is an important initiative to realize the goal of developing low-carbon city through energy saving and emissions reduction, while electric vehicles (EV) will play an important role in this transition due to their advantage in energy saving and lower carbon emissions. After reviewing the existing researches on energy saving and emissions reduction of electric vehicles, this paper analyzed the factors affecting carbon emissions reduction. Combining with electric vehicles promotion program in Beijing, the paper analyzed carbon emissions and reduction potential of electric vehicles in six scenarios using the optimized energy consumption related carbon emissions model from the perspective of fuel life cycle. The scenarios included power energy structure, fuel type (energy consumption per 100 km), car type (CO2 emission factor of fuel), urban traffic conditions (speed), coal-power technologies and battery type (weight, energy efficiency). The results showed that the optimized model was able to estimate carbon emissions caused by fuel consumption more reasonably; electric vehicles had an obvious restrictive carbon reduction potential with the fluctuation of 57%-81.2% in the analysis of six influencing factors, while power energy structure and coal-power technologies play decisive roles in life-cycle carbon emissions of electric vehicles with the reduction potential of 78.1% and 81.2%, respectively. Finally, some optimized measures were proposed to reduce transport energy consumption and carbon emissions during electric vehicles promotion including improving energy structure and coal technology, popularizing energy saving technologies and electric vehicles, accelerating the battery R&D and so on. The research provides scientific basis and methods for the policy development for the transition of new energy vehicles in low-carbon transport.

Energy Efficiency Resources to Support State Energy Planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Office of Strategic Programs, Strategic Priorities and Impact Analysis Team

An early step for most energy efficiency planning is to identify and quantify energy savings opportunities, and then to understand how to access this potential. The U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy offers resources that can help with both of these steps. This fact sheet presents those resources. The resources are also available on the DOE State and Local Solution Center on the "Energy Efficiency: Savings Opportunities and Benefits" page: https://energy.gov/eere/slsc/energy-efficiency-savings-opportunities-and-benefits.

A detailed evaluation of heating processes in the middle atmosphere

NASA Technical Reports Server (NTRS)

Mlynczak, Martin; Solomon, Susan

1994-01-01

A fundamental problem in the study of the terrestrial middle atmosphere is to calculate accurately the local heating due to the absorption of solar radiation. Knowledge of the heat budget is essential to understanding the atmospheric thermal structure, atmospheric motions, atmospheric chemistry, and their coupling. The evaluation of heating rates is complicated (especially above the stratopause) by the fact that the heating is not a simple one-step process. That is, the absorbed solar energy does not all immediately appear as heat. Rather, substantial portions of the incident energy may appear as internal energy of excited photolysis products (e.g., O(1D) or O2(1 delta)) or as chemical potential energy of product species such as atomic oxygen. The ultimate disposition of the internal and chemical energy possessed by the photolysis products determines the efficiency and thus the rate at which the middle atmosphere is heated. In studies of the heat budget, it is also vitally important to consider transport of long lived chemical species such as atomic oxygen above approximately 80 km. In such cases, the chemical potential energy may be transported great distances (horizontally or vertically) before undergoing a reaction to release the heat. Atomic oxygen influences the heating not only by reactions with itself and with O2 but also by reactions with odd-hydrogen species, especially those involving OH (Mlynczak and Solomon, 1991a). Consequently, absorbed solar energy may finally by converted to heat a long time after and at a location far from the original deposition. The purpose of this paper is to examine the solar and chemical heating processes and to present parameterizations for the heating efficiencies readily applicable for use in numerical models and heat budget studies. In the next two sections the processes relevant to the heating efficiencies for ozone and molecular oxygen will be reviewed. In section 4 the processes for the exothermic reactions will be reviewed and parameterizations for the heating efficiencies for both the solar and chemical processes will be presented in Section 5.

Energy efficiency public service advertising campaign

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gibson-Grant, Amanda

The Advertising Council (“the Ad Council”) and The United States Department of Energy (DOE) created and launched a national public service advertising campaign designed to promote energy efficiency. The objective of the Energy Efficiency campaign was to redefine how consumers approach energy efficiency by showing that saving energy can save homeowners money.

13 CFR 101.500 - Small Business Energy Efficiency Program.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Small Business Energy Efficiency... ADMINISTRATION Small Business Energy Efficiency § 101.500 Small Business Energy Efficiency Program. (a) The.../energy, building on the Energy Star for Small Business Program, to assist small business concerns in...

13 CFR 101.500 - Small Business Energy Efficiency Program.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Small Business Energy Efficiency... ADMINISTRATION Small Business Energy Efficiency § 101.500 Small Business Energy Efficiency Program. (a) The.../energy, building on the Energy Star for Small Business Program, to assist small business concerns in...

13 CFR 101.500 - Small Business Energy Efficiency Program.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Small Business Energy Efficiency... ADMINISTRATION Small Business Energy Efficiency § 101.500 Small Business Energy Efficiency Program. (a) The.../energy, building on the Energy Star for Small Business Program, to assist small business concerns in...

13 CFR 101.500 - Small Business Energy Efficiency Program.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Small Business Energy Efficiency... ADMINISTRATION Small Business Energy Efficiency § 101.500 Small Business Energy Efficiency Program. (a) The.../energy, building on the Energy Star for Small Business Program, to assist small business concerns in...

13 CFR 101.500 - Small Business Energy Efficiency Program.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Small Business Energy Efficiency... ADMINISTRATION Small Business Energy Efficiency § 101.500 Small Business Energy Efficiency Program. (a) The.../energy, building on the Energy Star for Small Business Program, to assist small business concerns in...

Measuring and explaining eco-efficiencies of wastewater treatment plants in China: An uncertainty analysis perspective.

PubMed

Dong, Xin; Zhang, Xinyi; Zeng, Siyu

2017-04-01

In the context of sustainable development, there has been an increasing requirement for an eco-efficiency assessment of wastewater treatment plants (WWTPs). Data envelopment analysis (DEA), a technique that is widely applied for relative efficiency assessment, is used in combination with the tolerances approach to handle WWTPs' multiple inputs and outputs as well as their uncertainty. The economic cost, energy consumption, contaminant removal, and global warming effect during the treatment processes are integrated to interpret the eco-efficiency of WWTPs. A total of 736 sample plants from across China are assessed, and large sensitivities to variations in inputs and outputs are observed for most samples, with only three WWTPs identified as being stably efficient. Size of plant, overcapacity, climate type, and influent characteristics are proven to have a significant influence on both the mean efficiency and performance sensitivity of WWTPs, while no clear relationships were found between eco-efficiency and technology under the framework of uncertainty analysis. The incorporation of uncertainty quantification and environmental impact consideration has improved the liability and applicability of the assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

State Energy Efficiency Benefits and Opportunities

EPA Pesticide Factsheets

Describes the benefits of energy efficiency and how to assess its potential for your state. Also, find details on energy efficiency policies, programs, and resources available for furthering energy efficiency goals.

Influence of Particle Size Distribution on the Performance of Ionic Liquid-based Electrochemical Double Layer Capacitors

PubMed Central

Rennie, Anthony J. R.; Martins, Vitor L.; Smith, Rachel M.; Hall, Peter J.

2016-01-01

Electrochemical double layer capacitors (EDLCs) employing ionic liquid electrolytes are the subject of much research as they promise increased operating potentials, and hence energy densities, when compared with currently available devices. Herein we report on the influence of the particle size distribution of activated carbon material on the performance of ionic liquid based EDLCs. Mesoporous activated carbon was ball-milled for increasing durations and the resultant powders characterized physically (using laser diffraction, nitrogen sorption and SEM) and investigated electrochemically in the form of composite EDLC electrodes. A bi-modal particle size distribution was found for all materials demonstrating an increasing fraction of smaller particles with increased milling duration. In general, cell capacitance decreased with increased milling duration over a wide range of rates using CV and galvanostatic cycling. Reduced coulombic efficiency is observed at low rates (<25 mVs−1) and the efficiency decreases as the volume fraction of the smaller particles increases. Efficiency loss was attributed to side reactions, particularly electrolyte decomposition, arising from interactions with the smaller particles. The effect of reduced efficiency is confirmed by cycling for over 15,000 cycles, which has the important implication that diminished performance and reduced cycle life is caused by the presence of submicron-sized particles. PMID:26911531

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bouzaki, Mohammed Moustafa, E-mail: bouzaki-physique1@yahoo.fr; Chadel, Meriem; Université de Lorraine, LMOPS, EA 4423, 57070 Metz

This contribution analyzes the energy provided by a solar kit dedicated to autonomous usage and installed in Central Europe (Longitude 6.10°; Latitude 49.21° and Altitude 160 m) by using the simulation software PVSYST. We focused the analysis on the effect of temperature and solar irradiation on the I-V characteristic of a commercial PV panel. We also consider in this study the influence of charging and discharging the battery on the generator efficiency. Meteorological data are integrated into the simulation software. As expected, the solar kit provides an energy varying all along the year with a minimum in December. In themore » proposed approach, we consider this minimum as the lowest acceptable energy level to satisfy the use. Thus for the other months, a lost in the available renewable energy exists if no storage system is associated.« less

Linking biofilm growth to fouling and aeration performance of fine-pore diffuser in activated sludge.

PubMed

Garrido-Baserba, Manel; Asvapathanagul, Pitiporn; McCarthy, Graham W; Gocke, Thomas E; Olson, Betty H; Park, Hee-Deung; Al-Omari, Ahmed; Murthy, Sudhir; Bott, Charles B; Wett, Bernhard; Smeraldi, Joshua D; Shaw, Andrew R; Rosso, Diego

2016-03-01

Aeration is commonly identified as the largest contributor to process energy needs in the treatment of wastewater and therefore garners significant focus in reducing energy use. Fine-pore diffusers are the most common aeration system in municipal wastewater treatment. These diffusers are subject to fouling and scaling, resulting in loss in transfer efficiency as biofilms form and change material properties producing larger bubbles, hindering mass transfer and contributing to increased plant energy costs. This research establishes a direct correlation and apparent mechanistic link between biofilm DNA concentration and reduced aeration efficiency caused by biofilm fouling. Although the connection between biofilm growth and fouling has been implicit in discussions of diffuser fouling for many years, this research provides measured quantitative connection between the extent of biofouling and reduced diffuser efficiency. This was clearly established by studying systematically the deterioration of aeration diffusers efficiency during a 1.5 year period, concurrently with the microbiological study of the biofilm fouling in order to understand the major factors contributing to diffuser fouling. The six different diffuser technologies analyzed in this paper included four different materials which were ethylene-propylene-diene monomer (EPDM), polyurethane, silicone and ceramic. While all diffusers foul eventually, some novel materials exhibited fouling resistance. The material type played a major role in determining the biofilm characteristics (i.e., growth rate, composition, and microbial density) which directly affected the rate and intensity at what the diffusers were fouled, whereas diffuser geometry exerted little influence. Overall, a high correlation between the increase in biofilm DNA and the decrease in αF was evident (CV < 14.0 ± 2.0%). By linking bacterial growth with aeration efficiency, the research was able to show quantitatively the causal connection between bacterial fouling and energy wastage during aeration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Assessing global resource utilization efficiency in the industrial sector.

PubMed

Rosen, Marc A

2013-09-01

Designing efficient energy systems, which also meet economic, environmental and other objectives and constraints, is a significant challenge. In a world with finite natural resources and large energy demands, it is important to understand not just actual efficiencies, but also limits to efficiency, as the latter identify margins for efficiency improvement. Energy analysis alone is inadequate, e.g., it yields energy efficiencies that do not provide limits to efficiency. To obtain meaningful and useful efficiencies for energy systems, and to clarify losses, exergy analysis is a beneficial and useful tool. Here, the global industrial sector and industries within it are assessed by using energy and exergy methods. The objective is to improve the understanding of the efficiency of global resource use in the industrial sector and, with this information, to facilitate the development, prioritization and ultimate implementation of rational improvement options. Global energy and exergy flow diagrams for the industrial sector are developed and overall efficiencies for the global industrial sector evaluated as 51% based on energy and 30% based on exergy. Consequently, exergy analysis indicates a less efficient picture of energy use in the global industrial sector than does energy analysis. A larger margin for improvement exists from an exergy perspective, compared to the overly optimistic margin indicated by energy. Copyright © 2012 Elsevier B.V. All rights reserved.

Building Energy Asset Score for Utilities and Energy Efficiency Program Administrators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Building Technologies Office

2015-01-01

The Building Energy Asset Score is a national standardized tool for evaluating the physical and structural energy efficiency of commercial and multifamily residential buildings. The Asset Score generates a simple energy efficiency rating that enables comparison among buildings, and identifies opportunities for users to invest in energy efficiency upgrades. It is web-based and free to use. This fact sheet discusses the value of the score for utilities and energy efficiency program administrators.

Carbon dioxide emissions and the overshoot ratio change resulting from the implementation of 2nd Energy Master Plan in South Korea

NASA Astrophysics Data System (ADS)

Yeo, M. J.; Kim, Y. P.

2015-12-01

The direction of the energy policies of the country is important in the projection of environmental impacts of the country. The greenhouse gases (GHGs) emission of the energy sector in South Korea is very huge, about 600 MtCO2e in 2011. Also the carbon footprint due to the energy consumption contributes to the ecological footprint is also large, more than 60%. Based on the official plans (the national greenhouse gases emission reduction target for 2030 (GHG target for 2030) and the 2nd Energy Master Plan (2nd EMP)), several scenarios were proposed and the sensitivity of the GHG emission amount and 'overshoot ratio' which is the ratio of ecological footprint to biocapacity were estimated. It was found that to meet the GHG target for 2030 the ratio of non-emission energy for power generation should be over 71% which would be very difficult. We also found that the overshoot ratio would increase from 5.9 in 2009 to 7.6 in 2035. Thus, additional efforts are required to reduce the environmental burdens in addition to optimize the power mix configuration. One example is the conversion efficiency in power generation. If the conversion efficiency in power generation rises up 50% from the current level, 40%, the energy demand and resultant carbon dioxide emissions would decrease about 10%. Also the influence on the environment through changes in consumption behavior, for example, the diet choice is expected to be meaningful.

Building technolgies program. 1994 annual report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Selkowitz, S.E.

1995-04-01

The objective of the Building Technologies program is to assist the U.S. building industry in achieving substantial reductions in building sector energy use and associated greenhouse gas emissions while improving comfort, amenity, health, and productivity in the building sector. We have focused our past efforts on two major building systems, windows and lighting, and on the simulation tools needed by researchers and designers to integrate the full range of energy efficiency solutions into achievable, cost-effective design solutions for new and existing buildings. In addition, we are now taking more of an integrated systems and life cycle perspective to create cost-effectivemore » solutions for more energy efficient, comfortable, and productive work and living environments. More than 30% of all energy use in buildings is attributable to two sources: windows and lighting. Together they account for annual consumer energy expenditures of more than $50 billion. Each affects not only energy use by other major building systems, but also comfort and productivity-factors that influence building economics far more than does direct energy consumption alone. Windows play a unique role in the building envelope, physically separating the conditioned space from the world outside without sacrificing vital visual contact. Throughout every space in a building, lighting systems facilitate a variety of tasks associated with a wide range of visual requirements while defining the luminous qualities of the indoor environment. Window and lighting systems are thus essential components of any comprehensive building science program.« less

What China can learn from international policy experiences to improve industrial energy efficiency and reduce CO 2 emissions?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Xu; Shen, Bo; Price, Lynn

China’s industrial sector dominates the country’s total energy consumption and energy efficiency in the industry sector is crucial to help China reach its energy and CO 2 emissions reduction goals. There are many energy efficiency policies in China, but the motivation and willingness of enterprises to improve energy efficiency has weakened. This report first identifies barriers that enterprises face to be self-motivated to implement energy efficiency measures. Then, this report reviews international policies and programs to improve energy efficiency and evaluates how these policies helped to address the identified barriers. Lastly, this report draws conclusions and provides recommendations to Chinamore » in developing policies and programs to motivate enterprises to improve energy efficiency.« less

Influence of ionic conductivity in bioelectricity production from saline domestic sewage sludge in microbial fuel cells.

PubMed

Karthikeyan, Rengasamy; Selvam, Ammayaippan; Cheng, Ka Yu; Wong, Jonathan Woon-Chung

2016-01-01

This study aimed at manipulating ionic conductivity (EC) to harvest the maximum electrical energy from seawater-based domestic wastewater sewage sludge (SWS), unique to only a few cities, through microbial fuel cell (MFC). SWS has never been investigated as a MFC substrate before, and thus the influence of high in-situ EC on the energy recovery was unknown. In this study, the EC of the SWS was reduced through mixing it with fresh water-based domestic wastewater sewage sludge (FWS) or diluted 50% using deionized water while FWS and SWS were individually served as reference treatments. SWS:FWS mix (1:1) exhibited a maximum Coulombic efficiency of 28.6±0.5% at a COD removal of 59±3% while the peak power density was 20-fold higher than FWS. The improved performance was due to the lower ohmic internal resistance (36.8±4.2Ω) and optimal conductivity (12.8±0.2mScm(-1)). Therefore, dilution with FWS could enhance energy recovery from SWS. Copyright © 2015 Elsevier Ltd. All rights reserved.

Improving domestic wastewater treatment efficiency with constructed wetland microbial fuel cells: Influence of anode material and external resistance.

PubMed

Corbella, Clara; Puigagut, Jaume

2018-08-01

For the past few years, there has been an increasing interest in the operation of constructed wetlands as microbial fuel cells (CW-MFCs) for both the improvement of wastewater treatment efficiency and the production of energy. However, there is still scarce information on design and operation aspects to maximize CW-MFCs efficiency, especially for the treatment of real domestic wastewater. The aim of this study was to quantify the extent of treatment efficiency improvement carried out by membrane-less MFCs simulating a core of a shallow un-planted horizontal subsurface flow constructed wetland. The influence of the external resistance (50, 220, 402, 604 and 1000Ω) and the anode material (graphite and gravel) on treatment efficiency improvement were addressed. To this purpose, 6 lab-scale membrane-less MFCs were set-up and loaded in batch mode with domestic wastewater for 13weeks. Results showed that 220Ω was the best operation condition for maximising MFCs treatment efficiency, regardless the anode material employed. Gravel-based anode MFCs operated at closed circuit showed ca. 18%, 15%, 31% and 25% lower effluent concentration than unconnected MFCs to the COD, TOC, PO 4 -3 and NH 4 + -N, respectively. Main conclusion of the present work is that constructed wetlands operated as MFCs is a promising strategy to improve domestic wastewater treatment efficiency. However, further studies at pilot scale under more realistic conditions (such as planted systems operated under continuous mode) shall be performed to confirm the findings here reported. Copyright © 2018 Elsevier B.V. All rights reserved.

10 CFR 429.70 - Alternative methods for determining energy efficiency or energy use.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Alternative methods for determining energy efficiency or energy use. 429.70 Section 429.70 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION CERTIFICATION....70 Alternative methods for determining energy efficiency or energy use. (a) General. A manufacturer...

10 CFR 429.70 - Alternative methods for determining energy efficiency or energy use.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Alternative methods for determining energy efficiency or energy use. 429.70 Section 429.70 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION CERTIFICATION....70 Alternative methods for determining energy efficiency or energy use. Link to an amendment...

Characterization of a spray torch and analysis of process parameters

NASA Astrophysics Data System (ADS)

Ramasamy, R.; Selvarajan, V.

1999-07-01

Anode for a non-transferred DC plasma spray torch was designed to improve electrothermal efficiency. A theoretical calculation was made for the electrothermal efficiency in a DC plasma torch operating with argon at atmospheric pressure with power level in the range of 5.2 20 kW using energy balance equations. ANOVA for the two level factorial design was done. Plasma gas flow rate, current intensity, nozzle diameter and length were found to influence the efficiency. The efficiency was found to decrease with increase in current intensity and nozzle length and to increase with increase in nozzle diameter and gas flow rate. The overall energy balance calculations showed that the heat transfer to the plasma-forming gas decreases with increase in arc current and the same was more significant at higher flow rates. Plasma jet velocity for different flow rates, input to the torch and nozzle dimensions was calculated from the gas enthalpy. It was found that the velocity increased with increase in the power input to the torch and gas flow rate and decreased with increase in nozzle length and diameter. The current voltage characteristics of the torch operating with argon gas were studied for different gas flow rates. The Nottingham coefficients were calculated using least square method.

A Robust, Water-Based, Functional Binder Framework for High-Energy Lithium-Sulfur Batteries.

PubMed

Lacey, Matthew J; Österlund, Viking; Bergfelt, Andreas; Jeschull, Fabian; Bowden, Tim; Brandell, Daniel

2017-07-10

We report here a water-based functional binder framework for the lithium-sulfur battery systems, based on the general combination of a polyether and an amide-containing polymer. These binders are applied to positive electrodes optimised towards high-energy electrochemical performance based only on commercially available materials. Electrodes with up to 4 mAh cm -2 capacity and 97-98 % coulombic efficiency are achievable in electrodes with a 65 % total sulfur content and a poly(ethylene oxide):poly(vinylpyrrolidone) (PEO:PVP) binder system. Exchange of either binder component for a different polymer with similar functionality preserves the high capacity and coulombic efficiency. The improvement in coulombic efficiency from the inclusion of the coordinating amide group was also observed in electrodes where pyrrolidone moieties were covalently grafted to the carbon black, indicating the role of this functionality in facilitating polysulfide adsorption to the electrode surface. The mechanical properties of the electrodes appear not to significantly influence sulfur utilisation or coulombic efficiency in the short term but rather determine retention of these properties over extended cycling. These results demonstrate the robustness of this very straightforward approach, as well as the considerable scope for designing binder materials with targeted properties. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Technology computer aided design of 29.5% efficient perovskite/interdigitated back contact silicon heterojunction mechanically stacked tandem solar cell for energy-efficient applications

NASA Astrophysics Data System (ADS)

Pandey, Rahul; Chaujar, Rishu

2017-04-01

A 29.5% efficient perovskite/SiC passivated interdigitated back contact silicon heterojunction (IBC-SiHJ) mechanically stacked tandem solar cell device has been designed and simulated. This is a substantial improvement of 40% and 15%, respectively, compared to the transparent perovskite solar cell (21.1%) and Si solar cell (25.6%) operated individually. The perovskite solar cell has been used as a top subcell, whereas 250- and 25-μm-thick IBC-SiHJ solar cells have been used as bottom subcells. The realistic technology computer aided design analysis has been performed to understand the physical processes in the device and to make reliable predictions of the behavior. The performance of the top subcell has been obtained for different acceptor densities and hole mobility in Spiro-MeOTAD along with the impact of counter electrode work function. To incorporate the effect of material quality, the influence of carrier lifetimes has also been studied for perovskite top and IBC-SiHJ bottom subcells. The optical and electrical behavior of the devices has been obtained for both standalone as well as tandem configuration. Results reported in this study reveal that the proposed four-terminal tandem device may open a new door for cost-effective and energy-efficient applications.

Flagellum motion in 2-D: Work rate and efficiency of the non-sinusoidal approach

NASA Astrophysics Data System (ADS)

Viridi, Sparisoma; Nuraini, Nuning; Stephanie, Monica; Rifqi, Ainur; Christina, Dina; Thania, Elsa; Sihite, Erland

2018-03-01

Today microorganisms have been widely used to support human life. Some examples include foodstuffs (Spirulina.sp), to help with medical needs, for mining purposes and more. On the other hand, the development of technology is also very big influence on human life. The combination of technology and health science will be very useful if we can develop it. One is the cancer treatment by utilizing the movement of the flagella to be made a nanorobot used as a carrier of cancer drugs. Movement of flagella that resembles the shape of the arc and straight line can be searched formulation and then applied to the manufacture of nanorobot tail. Then the nanorobot will carry a cancer drug that leads directly to the cancer cells. So hopefully with this nanorobot, can minimize the death of healthy cells around cancer cells. From the results of research and analysis of the movement of flagella, it can be concluded that the smaller the mass of the flagella, the greater the efficiency will be or will be more efficient. So, the energy needed nanorobot will be smaller. Model with non-sinusoidal approach (Brokaw, 1965) is discussed in this work and formulation to get the energy efficiency is proposed and analyzed. Unfortunately, there is a negative value in the formulation.

Influence of dehydrated nanotubed titanic acid on charge transport and luminescent properties of polymer light-emitting diodes with fluorescent dye

NASA Astrophysics Data System (ADS)

Qian, Lei; Bera, Debasis; Jin, Zhen-Sheng; Du, Zu-Liang; Xu, Zheng; Teng, Feng; Liu, Wei

2007-09-01

In this paper, we discuss the influence of dehydrated nanotubed titanic acid (DNTA) on charge transport and luminescent properties of polymer light-emitting diodes (PLEDs) doped with fluorescent dye. Photoluminescence results confirm the efficient energy transfer from PVK to 4-(dicyanom-ethylene)-2- t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) and tris-(8-hydroxtquinoline) aluminum (Alq 3) in a DNTA-doped device. The device showed lower turn-on voltages and higher charge current by doping with DNTA, which also caused a shift in the exciton's recombination region.

Elevating the triplet energy levels of dibenzofuran-based ambipolar phosphine oxide hosts for ultralow-voltage-driven efficient blue electrophosphorescence: from D-A to D-π-A systems.

PubMed

Han, Chunmiao; Zhang, Zhensong; Xu, Hui; Li, Jing; Zhao, Yi; Yan, Pengfei; Liu, Shiyong

2013-01-21

A series of donor (D)-π-acceptor (A)-type phosphine-oxide hosts (DBF(x) POPhCz(n)), which were composed of phenylcarbazole, dibenzofuran (DBF), and diphenylphosphine-oxide (DPPO) moieties, were designed and synthesized. Phenyl π-spacer groups were inserted between the carbazolyl and DBF groups, which effectively weakened the charge transfer and triplet-excited-state extension. As the result, the first triplet energy levels (T(1)) of DBF(x)POPhCz(n) are elevated to about 3.0 eV, 0.1 eV higher than their D-A-type analogues. Nevertheless, the electrochemical analysis and DFT calculations demonstrated the ambipolar characteristics of DBF(x)POPhCz(n). The phenyl π spacers hardly influenced the frontier molecular orbital (FMO) energy levels and the carrier-transporting ability of the materials. Therefore, these D-π-A systems are endowed with higher T(1) states, as well as comparable electrical properties to D-A systems. Phosphorescent blue-light-emitting diodes (PHOLEDs) that were based on DBF(x)POPhCz(n) not only inherited the ultralow driving voltages (2.4 V for onset, about 2.8 V at 200 cd m(-2), and <3.4 V at 1000 cd m(-2)) but also had much-improved efficiencies, including about 26 cd A(-1) for current efficiency, 30 Lm W(-1) for power efficiency, and 13% for external quantum efficiency, which were more than twice the values of devices that are based on conventional unipolar host materials. This performance makes DBFDPOPhCz(n) among the best hosts for ultralow-voltage-driven blue PHOLEDs reported so far. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

10 CFR 431.96 - Uniform test method for the measurement of energy efficiency of small, large, and very large...

Code of Federal Regulations, 2010 CFR

2010-01-01

... DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL... measurement of energy efficiency of small, large, and very large commercial package air conditioning and... section contains test procedures for measuring, pursuant to EPCA, the energy efficiency of any small...

Effect of the coefficient of friction and tightening speed on the preload induced at the dental implant complex with the finite element method.

PubMed

Bulaqi, Haddad Arabi; Mousavi Mashhadi, Mahmoud; Geramipanah, Farideh; Safari, Hamed; Paknejad, Mojgan

2015-05-01

To prevent screw loosening, a clear understanding of the factors influencing secure preload is necessary. The purpose of this study was to investigate the effect of coefficient of friction and tightening speed on screw tightening based on energy distribution method with exact geometric modeling and finite element analysis. To simulate the proper boundary conditions of the screw tightening process, the supporting bone of an implant was considered. The exact geometry of the implant complex, including the Straumann dental implant, direct crown attachment, and abutment screw were modeled with Solidworks software. Abutment screw/implant and implant/bone interfaces were designed as spiral thread helixes. The screw-tightening process was simulated with Abaqus software, and to achieve the target torque, an angular displacement was applied to the abutment screw head at different coefficients of friction and tightening speeds. The values of torque, preload, energy distribution, elastic energy, and efficiency were obtained at the target torque of 35 Ncm. Additionally, the torque distribution ratio and preload simulated values were compared to theoretically predicted values. Upon reducing the coefficient of friction and enhancing the tightening speed, the angle of turn increased at the target torque. As the angle of turn increased, the elastic energy and preload also increased. Additionally, by increasing the coefficient of friction, the frictional dissipation energy increased but the efficiency decreased, whereas the increase in tightening speed insignificantly affected efficiency. The results of this study indicate that the coefficient of friction is the most influential factor on efficiency. Increasing the tightening speed lowered the response rate to the frictional resistance, thus diminishing the coefficient of friction and slightly increasing the preload. Increasing the tightening speed has the same result as reducing the coefficient of friction. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

75 FR 17700 - Energy Efficient Building Systems Regional Innovation Cluster Initiative-Joint Federal Funding...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-07

... economically dynamic regional innovation cluster focused on energy efficient buildings technologies and systems... DEPARTMENT OF ENERGY Energy Efficient Building Systems Regional Innovation Cluster Initiative... February 8, 2010, titled the Energy Efficient Building Systems Regional Innovation Cluster Initiative. A...

Empirical Study on Total Factor Productive Energy Efficiency in Beijing-Tianjin-Hebei Region-Analysis based on Malmquist Index and Window Model

NASA Astrophysics Data System (ADS)

Xu, Qiang; Ding, Shuai; An, Jingwen

2017-12-01

This paper studies the energy efficiency of Beijing-Tianjin-Hebei region and to finds out the trend of energy efficiency in order to improve the economic development quality of Beijing-Tianjin-Hebei region. Based on Malmquist index and window analysis model, this paper estimates the total factor energy efficiency in Beijing-Tianjin-Hebei region empirically by using panel data in this region from 1991 to 2014, and provides the corresponding political recommendations. The empirical result shows that, the total factor energy efficiency in Beijing-Tianjin-Hebei region increased from 1991 to 2014, mainly relies on advances in energy technology or innovation, and obvious regional differences in energy efficiency to exist. Throughout the window period of 24 years, the regional differences of energy efficiency in Beijing-Tianjin-Hebei region shrank. There has been significant convergent trend in energy efficiency after 2000, mainly depends on the diffusion and spillover of energy technologies.

78 FR 20896 - Renewable Energy and Energy Efficiency Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-08

... DEPARTMENT OF COMMERCE International Trade Administration Renewable Energy and Energy Efficiency... of an Open Meeting. SUMMARY: The Renewable Energy and Energy Efficiency Advisory Committee (RE&EEAC...: Ryan Mulholland, Office of Energy and Environmental Industries (OEEI), International Trade...

Choice of optimal working fluid for binary power plants at extremely low temperature brine

NASA Astrophysics Data System (ADS)

Tomarov, G. V.; Shipkov, A. A.; Sorokina, E. V.

2016-12-01

The geothermal energy development problems based on using binary power plants utilizing lowpotential geothermal resources are considered. It is shown that one of the possible ways of increasing the efficiency of heat utilization of geothermal brine in a wide temperature range is the use of multistage power systems with series-connected binary power plants based on incremental primary energy conversion. Some practically significant results of design-analytical investigations of physicochemical properties of various organic substances and their influence on the main parameters of the flowsheet and the technical and operational characteristics of heat-mechanical and heat-exchange equipment for binary power plant operating on extremely-low temperature geothermal brine (70°C) are presented. The calculation results of geothermal brine specific flow rate, capacity (net), and other operation characteristics of binary power plants with the capacity of 2.5 MW at using various organic substances are a practical interest. It is shown that the working fluid selection significantly influences on the parameters of the flowsheet and the operational characteristics of the binary power plant, and the problem of selection of working fluid is in the search for compromise based on the priorities in the field of efficiency, safety, and ecology criteria of a binary power plant. It is proposed in the investigations on the working fluid selection of the binary plant to use the plotting method of multiaxis complex diagrams of relative parameters and characteristic of binary power plants. Some examples of plotting and analyzing these diagrams intended to choose the working fluid provided that the efficiency of geothermal brine is taken as main priority.

Energy Efficiency and Sustainability of Different Building Structures in Latvian Climate

NASA Astrophysics Data System (ADS)

Jakovičs, A.; Gendelis, S.; Bandeniece, L.

2015-11-01

Five experimental test buildings have been built in Riga, Latvia. They are identical except external walls for which different mainly regional building materials are used. Calculated U-values of the other walls, floor and ceiling are the same for each test building. Initial moisture influences the relative humidity of indoor air, which can be higher in the initial time period; as a result, heat transmittances are also very different and cause different heating/cooling energy consumption. Overheating risk in summer exists for test buildings with the smallest thermal inertia. Both summer and heating seasons have been analysed and differences between five test houses have been discussed in details.

Electron transmission through a steel capillary

NASA Astrophysics Data System (ADS)

Maljković, J. B.; Borka, D.; Ranković, M. Lj.; Marinković, B. P.; Milosavljević, A. R.; Lemell, C.; Tőkési, K.

2018-05-01

The transmission of low-energy electrons through a macroscopic steel capillary has been investigated both experimentally and theoretically. The length of the steel capillary was L = 19.5 mm and the inner diameter was d = 0.9 mm. The kinetic energy distribution of electrons transmitted through the steel capillary was recorded for a tilt angle of ψ = 2.6 ° of the incident electron beam with respect to the capillary axis. Accompanying simulations based on classical transport theory reproduce the experimental data to a high degree of agreement. Transmission for other tilt angles has also been simulated to investigate the influence of the tilt angle on the guiding efficiency.

Transportation energy efficiency trends in the 1990s

DOT National Transportation Integrated Search

2003-04-01

In the 1990s : The transportation sector showed little increase : in energy efficiency as transportation activity and : energy use continued to grow. : Passenger travel energy-efficiency levels : improved slightly, mainly due to efficiency ga...

76 FR 44576 - Renewable Energy and Energy Efficiency Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-26

... DEPARTMENT OF COMMERCE International Trade Administration Renewable Energy and Energy Efficiency... of an Open Meeting. SUMMARY: The Renewable Energy and Energy Efficiency Advisory Committee (RE&EEAC... administration of programs and policies to expand the competitiveness of the U.S. renewable energy and energy...

78 FR 55245 - Activities and Methodology for Assessing Compliance With Building Energy Codes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-10

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy [Docket No. EERE-2013-BT-BC... Energy Efficiency and Renewable Energy, Department of Energy. ACTION: Notice of reopening of public..., Office of Energy Efficiency and Renewable Energy, Building Technologies Program, Mailstop EE-2J, 1000...

75 FR 69653 - Energy Conservation Program for Consumer Products: Decision and Order Granting a Waiver to...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-15

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy [Case No. CW-015] Energy... November 4, 2010. Cathy Zoi, Assistant Secretary, Energy Efficiency and Renewable Energy. Decision and...)(1)(iii). The Assistant Secretary for Energy Efficiency and Renewable Energy (the Assistant Secretary...

77 FR 50489 - Office of Energy Efficiency and Renewable Energy

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-21

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy Wind and Water Power Program AGENCY: Office of Energy Efficiency and Renewable Energy, Department of Energy. ACTION: Notice of public meeting. SUMMARY: The Department of Energy (DOE) Wind and Water Power Program (WWPP) is planning a...

77 FR 6783 - Renewable Energy and Energy Efficiency Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-09

... DEPARTMENT OF COMMERCE International Trade Administration Renewable Energy and Energy Efficiency... of an open meeting. SUMMARY: The Renewable Energy and Energy Efficiency Advisory Committee (RE&EEAC... competitiveness of U.S. renewable [[Page 6784

75 FR 7464 - Energy Efficient Building Systems Regional Innovation Cluster Initiative-Joint Federal Funding...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-19

... DEPARTMENT OF ENERGY Energy Efficient Building Systems Regional Innovation Cluster Initiative... Energy Efficient Building Systems Regional Innovation Cluster Initiative. A single proposal submitted by... systems design. The DOE funded Energy Efficient Building Systems Design Hub (the ``Hub'') will serve as a...

Design of China Leading Energy Efficiency Program (LEP) for equipment and appliances and comparative study of international experience on super-efficient products

NASA Astrophysics Data System (ADS)

Liang, Xiuying; Zhu, Chunyan

2017-11-01

With rising global emphasizes on climate change and sustainable development, how to accelerate the transformation of energy efficiency has become an important question. Designing and implementing energy-efficiency policies for super-efficient products represents an important direction to achieve breakthroughs in the field of energy conservation. On December 31, 2014, China’s National Development and Reform Commission (NDRC) jointly six other ministerial agencies launched China Leading Energy Efficiency Program (LEP), which identifies top efficiency models for selected product categories. LEP sets the highest energy efficiency benchmark. Design of LEP took into consideration of how to best motivate manufacturers to accelerate technical innovation, promote high efficiency products. This paper explains core elements of LEP, such as objectives, selection criteria, implementation method and supportive policies. It also proposes recommendations to further improve LEP through international policy comparison with Japan’s Top Runner Program, U.S. Energy Star Most Efficient, and SEAD Global Efficiency Medal.

76 FR 11233 - Energy Conservation Program for Consumer Products: Decision and Order Granting a Waiver to LG...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-01

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy [Case No. CW-016] Energy... Energy Residential Clothes Washer Test Procedure AGENCY: Office of Energy Efficiency and Renewable Energy... 23, 2011. Cathy Zoi, Assistant Secretary, Energy Efficiency and Renewable Energy. Decision and Order...

78 FR 69370 - Renewable Energy and Energy Efficiency Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-19

... DEPARTMENT OF COMMERCE International Trade Administration Renewable Energy and Energy Efficiency... of an open meeting. SUMMARY: The Renewable Energy and Energy Efficiency Advisory Committee (RE&EEAC... INFORMATION CONTACT: Ryan Mulholland, Office of Energy and Environmental Industries (OEEI), International...

75 FR 70214 - Renewable Energy and Energy Efficiency Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-17

... DEPARTMENT OF COMMERCE International Trade Administration Renewable Energy and Energy Efficiency... of an open meeting. SUMMARY: The Renewable Energy and Energy Efficiency Advisory Committee (RE&EEAC... INFORMATION CONTACT: Brian O'Hanlon, Office of Energy and Environmental Technologies Industries (OEEI...

10 CFR 431.324 - Uniform test method for the measurement of energy efficiency of metal halide ballasts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... efficiency of metal halide ballasts. 431.324 Section 431.324 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Metal Halide Lamp Ballasts and Fixtures Test Procedures § 431.324 Uniform test method for the measurement of energy efficiency of metal...

Contracting for Efficiency. A Best Practices Guide for Energy-Efficient Product Procurement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bunch, Saralyn; Payne, Christopher

2016-04-01

The requirement to buy energy- and water-efficient products applies to federal purchases made through any procurement pathway (e.g., purchase cards, e-retailers, and solicitations) and to a wide variety of federal projects. The Federal Energy Management Program’s (FEMP's) Buy Energy-Efficient Products buyer overview fact sheet and Contracting for Efficiency best practices guide for product procurement are designed to support federal buyers in the purchase of energy- and water-efficient products.

Contracting for Efficiency: A Best Practices Guide for Energy Efficient Product Procurement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bunch, Saralyn; Payne, Christopher

The requirement to buy energy- and water-efficient products applies to federal purchases made through any procurement pathway (e.g., purchase cards, e-retailers, and solicitations) and to a wide variety of federal projects. The Federal Energy Management Program’s (FEMP's) Buy Energy-Efficient Products buyer overview fact sheet and Contracting for Efficiency best practices guide for product procurement are designed to support federal buyers in the purchase of energy- and water-efficient products.

77 FR 64112 - Office of Energy Efficiency and Renewable Energy

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-18

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy Nationwide Categorical Waivers of the American Recovery and Reinvestment Act AGENCY: Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy (DOE). ACTION: Notice of Amended Limited Waivers. SUMMARY: The U.S...

48 CFR 23.000 - Scope.

Code of Federal Regulations, 2012 CFR

2012-10-01

... ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE... reducing energy and water use in Government facilities; (c) Using renewable energy and renewable energy technologies; (d) Acquiring energy-efficient and water-efficient products and services, environmentally...

48 CFR 23.000 - Scope.

Code of Federal Regulations, 2011 CFR

2011-10-01

... ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE... reducing energy and water use in Government facilities; (c) Using renewable energy and renewable energy technologies; (d) Acquiring energy-efficient and water-efficient products and services, environmentally...

48 CFR 23.000 - Scope.

Code of Federal Regulations, 2014 CFR

2014-10-01

... ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE... reducing energy and water use in Government facilities; (c) Using renewable energy and renewable energy technologies; (d) Acquiring energy-efficient and water-efficient products and services, environmentally...

48 CFR 23.000 - Scope.

Code of Federal Regulations, 2013 CFR

2013-10-01

... ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE... reducing energy and water use in Government facilities; (c) Using renewable energy and renewable energy technologies; (d) Acquiring energy-efficient and water-efficient products and services, environmentally...

Interactions between Energy Efficiency Programs funded under the Recovery Act and Utility Customer-Funded Energy Efficiency Programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldman, Charles A.; Stuart, Elizabeth; Hoffman, Ian

2011-02-25

Since the spring of 2009, billions of federal dollars have been allocated to state and local governments as grants for energy efficiency and renewable energy projects and programs. The scale of this American Reinvestment and Recovery Act (ARRA) funding, focused on 'shovel-ready' projects to create and retain jobs, is unprecedented. Thousands of newly funded players - cities, counties, states, and tribes - and thousands of programs and projects are entering the existing landscape of energy efficiency programs for the first time or expanding their reach. The nation's experience base with energy efficiency is growing enormously, fed by federal dollars andmore » driven by broader objectives than saving energy alone. State and local officials made countless choices in developing portfolios of ARRA-funded energy efficiency programs and deciding how their programs would relate to existing efficiency programs funded by utility customers. Those choices are worth examining as bellwethers of a future world where there may be multiple program administrators and funding sources in many states. What are the opportunities and challenges of this new environment? What short- and long-term impacts will this large, infusion of funds have on utility customer-funded programs; for example, on infrastructure for delivering energy efficiency services or on customer willingness to invest in energy efficiency? To what extent has the attribution of energy savings been a critical issue, especially where administrators of utility customer-funded energy efficiency programs have performance or shareholder incentives? Do the new ARRA-funded energy efficiency programs provide insights on roles or activities that are particularly well-suited to state and local program administrators vs. administrators or implementers of utility customer-funded programs? The answers could have important implications for the future of U.S. energy efficiency. This report focuses on a selected set of ARRA-funded energy efficiency programs administered by state energy offices: the State Energy Program (SEP) formula grants, the portion of Energy Efficiency and Conservation Block Grant (EECBG) formula funds administered directly by states, and the State Energy Efficient Appliance Rebate Program (SEEARP). Since these ARRA programs devote significant monies to energy efficiency and serve similar markets as utility customer-funded programs, there are frequent interactions between programs. We exclude the DOE low-income weatherization program and EECBG funding awarded directly to the over 2,200 cities, counties and tribes from our study to keep its scope manageable. We summarize the energy efficiency program design and funding choices made by the 50 state energy offices, 5 territories and the District of Columbia. We then focus on the specific choices made in 12 case study states. These states were selected based on the level of utility customer program funding, diversity of program administrator models, and geographic diversity. Based on interviews with more than 80 energy efficiency actors in those 12 states, we draw observations about states strategies for use of Recovery Act funds. We examine interactions between ARRA programs and utility customer-funded energy efficiency programs in terms of program planning, program design and implementation, policy issues, and potential long-term impacts. We consider how the existing regulatory policy framework and energy efficiency programs in these 12 states may have impacted development of these selected ARRA programs. Finally, we summarize key trends and highlight issues that evaluators of these ARRA programs may want to examine in more depth in their process and impact evaluations.« less

76 FR 35199 - Proposed Agency Information Collection

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-16

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy Proposed Agency Information Collection AGENCY: Office of Energy Efficiency and Renewable Energy, Department of Energy. ACTION: Notice and.... Issued in Washington, DC, on June 9, 2011. Henry Kelly, Acting Assistant Secretary, Energy Efficiency and...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reed, David M.; Thomsen, Edwin C.; Wang, Wei

Three Nafion membranes of similar composition but different thicknesses were operated in a 3-cell 1kW class all vanadium mixed acid redox flow battery. The influence of current density on the charge/discharge characteristics, coulombic and energy efficiency, capacity fade, operating temperature and pressure drop in the flow circuit will be discussed and correlated to the Nafion membrane thickness. Material costs associated with the Nafion membranes, ease of handling the membranes, and performance impacts will also be discussed.

Polarization of the induced THz emission of donors in silicon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kovalevsky, K. A., E-mail: atan4@yandex.ru; Zhukavin, R. Kh.; Tsyplenkov, V. V.

2016-12-15

The polarization of the terahertz (4.9–6.4 THz) stimulated emission of Group-V (Sb, P, As, Bi) donors in single-crystal silicon under pumping (photoionization) by a CO{sub 2} laser (photon energy 117 meV), depending on the uniaxial compressive deformation of the crystal along the [100] axis, is experimentally investigated. The influence of the field direction of the pump wave on its efficiency is discussed.

Microwave drying remediation of petroleum-contaminated drill cuttings.

PubMed

Júnior, Irineu Petri; Martins, André Leibsohn; Ataíde, Carlos H; Duarte, Cláudio R

2017-07-01

The oil reservoir drilling phase generates contaminated cuttings with oil formation itself. These cuttings must be subjected to a decontamination process before being disposed of in the environment. Several technologies are cited in literature for the remediation of soil contaminated with oil or diesel, but none have been reported to remedy drill cuttings contaminated with oil from reservoir. The reservoir drill cuttings are a problem because its discharge is not allowed. The drying technology using microwave has shown promise in the decontamination of cuttings with non-aqueous base drilling fluid, conciliating good robustness and high removal efficiency. Considering the aspects mentioned previously, the application of heating and drying technology using microwave in the remediation of oil contaminated cuttings from well drill was studied. The influence of temperature, specific energy and initial content of water in the drying operation of the reservoir cuttings and of the drilling cuttings artificially contaminated with oil were analyzed. The results showed an influence of temperature in the drying of the cuttings, being necessary to reach the boiling temperature of heavier hydrocarbons to reach an efficient removal in the operation. The specific energy has a strong influence, reaching a total decontamination using 2.67 kWh/kg. The initial water content was effective in removing oil, reducing the residual level of oil with the increase of initial content of water. It also modifies the temperature profiles of the kinetic-warming of the contaminated cuttings. Both the technology and the equipment used proved effective for obtaining total decontamination of oil from the cuttings. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modelling the energy costs of the wastewater treatment process: The influence of the aging factor.

PubMed

Castellet-Viciano, Lledó; Hernández-Chover, Vicent; Hernández-Sancho, Francesc

2018-06-01

Wastewater treatment plants (WWTPs) are aging and its effects on the process are more evident as time goes by. Due to the deterioration of the facilities, the efficiency of the treatment process decreases gradually. Within this framework, this paper proves the increase in the energy consumption of the WWTPs with time, and finds differences among facilities size. Accordingly, the paper aims to develop a dynamic energy cost function capable of predicting the energy cost of the process in the future. The time variable is used to introduce the aging effects on the energy cost estimation in order to increase the accuracy of the estimation. For this purpose, the evolution of energy costs will be assessed and modelled for a group of WWTPs using the methodology of cost functions. The results will be useful for the managers of the facilities in the decision making process. Copyright © 2017 Elsevier B.V. All rights reserved.

Use of Ultrasonic Energy in Assessing Microbial Contamination on Surfaces

PubMed Central

Puleo, John R.; Favero, Martin S.; Petersen, Norman J.

1967-01-01

Ultrasonic tanks were evaluated for their ability to remove viable microorganisms from various surfaces for subsequent enumeration. Test surfaces were polished stainless steel, smooth glass, frosted glass, and electronic components. The position of contaminated surfaces in relation to the ultrasonic energy source, distance of the ultrasonic source from the test surfaces, and temperature of the rinse fluid were some of the factors which influenced recovery. Experimental systems included both naturally occurring microbial contamination and artificial contamination with spores of Bacillus subtilis var. niger. The results showed that ultrasonic energy was more reliable and efficient than mechanical agitation for recovering surface contaminants. Conditions which increased the number and percentage of microorganisms recovered by ultrasonic energy were: using a cold rinse fluid, placing the sample bottle on the bottom of the ultrasonic tank, and facing the contaminated surfaces toward the energy source. It was also demonstrated that ultrasonic energy could be effectively used for eluting microorganisms from cotton swabs. PMID:16349743

78 FR 33838 - DOE Participation in Development of the International Energy Conservation Code

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-05

... DEPARTMENT OF ENERGY Office of Energy Efficiency and Renewable Energy [Docket No. EERE-2012-BT-BC... Energy Efficiency and Renewable Energy, Department of Energy. ACTION: Notice and request for comment... Efficiency and Renewable Energy, Building Technologies Office, Mailstop EE-2J, 1000 Independence Avenue SW...

75 FR 29993 - Department of Commerce: Trade Promotion Coordinating Committee Renewable Energy and Energy...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-28

... Coordinating Committee Renewable Energy and Energy Efficiency Export Strategy To Support the National Export... Trade Promotion Coordinating Committee's (TPCC) Renewable Energy and Energy Efficiency Working Group is developing a U.S. Renewable Energy and Energy Efficiency Export Strategy (the Strategy) to guide U.S...

10 CFR 433.4 - Energy efficiency performance standard.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Energy efficiency performance standard. 433.4 Section 433.4 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR THE DESIGN AND CONSTRUCTION OF NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL BUILDINGS § 433.4 Energy...

10 CFR 433.4 - Energy efficiency performance standard.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 3 2011-01-01 2011-01-01 false Energy efficiency performance standard. 433.4 Section 433.4 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR THE DESIGN AND CONSTRUCTION OF NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH-RISE RESIDENTIAL BUILDINGS § 433.4 Energy...

10 CFR 905.17 - What are the requirements for the energy efficiency and/or renewable energy report (EE/RE report...

Code of Federal Regulations, 2013 CFR

2013-01-01

... renewable energy report (EE/RE report) alternative? 905.17 Section 905.17 Energy DEPARTMENT OF ENERGY ENERGY... energy efficiency and/or renewable energy report (EE/RE report) alternative? (a) Requests to submit an EE..., including any requirements for documenting customer energy efficiency and renewable energy activities. (b...

10 CFR 905.17 - What are the requirements for the energy efficiency and/or renewable energy report (EE/RE report...

Code of Federal Regulations, 2011 CFR

2011-01-01

... renewable energy report (EE/RE report) alternative? 905.17 Section 905.17 Energy DEPARTMENT OF ENERGY ENERGY... energy efficiency and/or renewable energy report (EE/RE report) alternative? (a) Requests to submit an EE..., including any requirements for documenting customer energy efficiency and renewable energy activities. (b...

10 CFR 905.17 - What are the requirements for the energy efficiency and/or renewable energy report (EE/RE report...

Code of Federal Regulations, 2014 CFR

2014-01-01

... renewable energy report (EE/RE report) alternative? 905.17 Section 905.17 Energy DEPARTMENT OF ENERGY ENERGY... energy efficiency and/or renewable energy report (EE/RE report) alternative? (a) Requests to submit an EE..., including any requirements for documenting customer energy efficiency and renewable energy activities. (b...

10 CFR 905.17 - What are the requirements for the energy efficiency and/or renewable energy report (EE/RE report...

Code of Federal Regulations, 2012 CFR

2012-01-01

... renewable energy report (EE/RE report) alternative? 905.17 Section 905.17 Energy DEPARTMENT OF ENERGY ENERGY... energy efficiency and/or renewable energy report (EE/RE report) alternative? (a) Requests to submit an EE..., including any requirements for documenting customer energy efficiency and renewable energy activities. (b...

The evaluation model of the enterprise energy efficiency based on DPSR.

PubMed

Wei, Jin-Yu; Zhao, Xiao-Yu; Sun, Xue-Shan

2017-05-08

The reasonable evaluation of the enterprise energy efficiency is an important work in order to reduce the energy consumption. In this paper, an effective energy efficiency evaluation index system is proposed based on DPSR (Driving forces-Pressure-State-Response) with the consideration of the actual situation of enterprises. This index system which covers multi-dimensional indexes of the enterprise energy efficiency can reveal the complete causal chain which includes the "driver forces" and "pressure" of the enterprise energy efficiency "state" caused by the internal and external environment, and the ultimate enterprise energy-saving "response" measures. Furthermore, the ANP (Analytic Network Process) and cloud model are used to calculate the weight of each index and evaluate the energy efficiency level. The analysis of BL Company verifies the feasibility of this index system and also provides an effective way to improve the energy efficiency at last.

Characterizing Synergistic Water and Energy Efficiency at the Residential Scale Using a Cost Abatement Curve Approach

NASA Astrophysics Data System (ADS)

Stillwell, A. S.; Chini, C. M.; Schreiber, K. L.; Barker, Z. A.

2015-12-01

Energy and water are two increasingly correlated resources. Electricity generation at thermoelectric power plants requires cooling such that large water withdrawal and consumption rates are associated with electricity consumption. Drinking water and wastewater treatment require significant electricity inputs to clean, disinfect, and pump water. Due to this energy-water nexus, energy efficiency measures might be a cost-effective approach to reducing water use and water efficiency measures might support energy savings as well. This research characterizes the cost-effectiveness of different efficiency approaches in households by quantifying the direct and indirect water and energy savings that could be realized through efficiency measures, such as low-flow fixtures, energy and water efficient appliances, distributed generation, and solar water heating. Potential energy and water savings from these efficiency measures was analyzed in a product-lifetime adjusted economic model comparing efficiency measures to conventional counterparts. Results were displayed as cost abatement curves indicating the most economical measures to implement for a target reduction in water and/or energy consumption. These cost abatement curves are useful in supporting market innovation and investment in residential-scale efficiency.

Application of heterogeneous blading systems is the way for improving efficiency of centrifugal energy pumps

NASA Astrophysics Data System (ADS)

Pochylý, F.; Haluza, M.; Fialová, S.; Dobšáková, L.; Volkov, A. V.; Parygin, A. G.; Naumov, A. V.; Vikhlyantsev, A. A.; Druzhinin, A. A.

2017-11-01

The results of independent research implemented by the teams of authors representing the Brno University of technology (Czech Republic) and Moscow Power Engineering Institute National Research University (Russia) are presented and compared. The possibilities for improving the energy efficiency of slow-speed centrifugal pumps (with a specific speed coefficient n s < 80) widely used in power engineering—in thermal power stations, in heat electric-power stations, in nuclear power plants, and in boiler rooms—were investigated. These are supply pumps, condensate pumps, precharge pumps, etc. The pumps with such values of n s are widely used in some technological cycles of oil-and-gas and chemical industries too. The research was focused on achieving the shape of the pump efficiency characteristics providing a significant extension of its effective working zone and increasing its integrated efficiency. The results were obtained based on new approaches to the formation of a blading system of an impeller of a slow-speed centrifugal pump different from the traditional blading system. The analytical dependences illustrating the influence of individual geometry of a blading system on the efficiency were presented. The possibilities of purposeful changing of its structure were demonstrated. It was experimentally confirmed that use of the innovative blading system makes it possible to increase the pump efficiency by 1-4% (in the experiments for the pumps with n s = 33 and 55) and to extend its efficient working zone approximately by 15-20% (in the experiment for the pumps with n s = 33 and 66). The latter is especially important for the supply pumps of NPP power units. The experimental results for all investigated pumps are presented in comparison with the characteristics of the efficiency provided by the blading systems designed by traditional methods.

Energy Efficiency Programs in K-12 Schools: A Guide to Developing and Implementing Greenhouse Gas Reduction Programs. Local Government Climate and Energy Strategy Series

ERIC Educational Resources Information Center

US Environmental Protection Agency, 2011

2011-01-01

Saving energy through energy efficiency improvements can cost less than generating, transmitting, and distributing energy from power plants, and provides multiple economic and environmental benefits. Local governments can promote energy efficiency in their jurisdictions by developing and implementing strategies that improve the efficiency of…