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1

Thermohydraulic Analysis of the Z-Pinch Power Plant Primary Cycle  

Microsoft Academic Search

In this paper, we investigate the thermohydraulic characteristics of the Z-pinch power plant (ZIFE) primary cycle. The generation of electric energy using a power cycle is possible only if a minimum operating temperature is achieved and maintained in the primary cycle. Many energy losses are associated with the operation of the primary cycle. These thermal and pressure losses have a

M. A. Modesto; C. W. Morrow; E. R. Lindgren; V. L. Vigil

2005-01-01

2

Life cycle air emissions impacts and ownership costs of light-duty vehicles using natural gas as a primary energy source.  

PubMed

This paper aims to comprehensively distinguish among the merits of different vehicles using a common primary energy source. In this study, we consider compressed natural gas (CNG) use directly in conventional vehicles (CV) and hybrid electric vehicles (HEV), and natural gas-derived electricity (NG-e) use in plug-in battery electric vehicles (BEV). This study evaluates the incremental life cycle air emissions (climate change and human health) impacts and life cycle ownership costs of non-plug-in (CV and HEV) and plug-in light-duty vehicles. Replacing a gasoline CV with a CNG CV, or a CNG CV with a CNG HEV, can provide life cycle air emissions impact benefits without increasing ownership costs; however, the NG-e BEV will likely increase costs (90% confidence interval: $1000 to $31?000 incremental cost per vehicle lifetime). Furthermore, eliminating HEV tailpipe emissions via plug-in vehicles has an insignificant incremental benefit, due to high uncertainties, with emissions cost benefits between -$1000 and $2000. Vehicle criteria air contaminants are a relatively minor contributor to life cycle air emissions impacts because of strict vehicle emissions standards. Therefore, policies should focus on adoption of plug-in vehicles in nonattainment regions, because CNG vehicles are likely more cost-effective at providing overall life cycle air emissions impact benefits. PMID:25825338

Luk, Jason M; Saville, Bradley A; MacLean, Heather L

2015-04-21

3

Interfacing primary heat sources and cycles for thermochemical hydrogen production  

SciTech Connect

Advantages cited for hydrogen production from water by coupling thermochemical cycles with primary heat include the possibility of high efficiencies. These can be realized only if the cycle approximates the criteria required to match the characteristics of the heat source. Different types of cycles may be necessary for fission reactors, for fusion reactors or for solar furnaces. Very high temperature processes based on decomposition of gaseous H/sub 2/O or CO/sub 2/ appear impractical even for projected solar technology. Cycles based on CdO decomposition are potentially quite efficient and require isothermal heat at temperatures that may be available from solar furnaces of fusion reactors. Sulfuric acid and solid sulfate cycles are potentially useful at temperatures available from each heat source. Solid sulfate cycles offer advantages for isothermal heat sources. All cycles under development include concentration and drying steps. Novel methods for improving such operations would be beneficial.

Bowman, M.G.

1980-01-01

4

Energy Cycle in Living Things  

NSDL National Science Digital Library

This diagram shows how energy from the sun cycles through plants and animals. Plants create sugars through photosynthesis which animals can then use for energy. ATP, glucose, and the mitochondria are also explained. Many key terms are hyperlinked to provide more detailed definitions.

2012-06-19

5

II. An ecosystem's energy budget depends on primary productivity  

E-print Network

Introduction of Exotic Species B. Habitat Destruction and the Biodiversity Crisis IX. The Sustainable Biosphere Initiative is reorienting ecological research OBJECTIVES After reading this chapter and attending lecture, the student should be able to: 1. Explain the importance of autotrophic organisms with respect to energy flow and nutrient cycling in ecosystems. 2. List and describe the importance of the four consumer levels found in an ecosystem. 3. Explain how gross primary productivity is allocated by the plants in an ecosystem. 4. List the factors that can limit productivity of an ecosystem. 5. Explain why productivity declines at each trophic level. 6. Distinguish between energy pyramids and biomass pyramids. 7. Describe the hydrologic (water) cycle. 8. Describe the carbon cycle and explain why it is said to result from the reciprocal processes of photosynthesis and cellular respiration. 9. Describe the nitrogen cycle and explain the importance

6

NEED Project: Primary Science of Energy Infobook  

NSDL National Science Digital Library

This free infobook provides an overview of energy forms and sources for Grades 2-4, along with hands-on activities, graphics, and classroom presentation materials for teaching an entire unit. Students will first be introduced to energy as a physical science concept before being exposed to sources of energy. Using this sequence can help learners differentiate energy forms (thermal, motion, wave, chemical) from energy sources (fossil fuels, wind, geothermal, hydroelectric). For the companion Student Guide with printable data guides and activities, Primary%20Science%20of%20Energy%20Student%20Guide.pdf" target="_blank">Primary Science of Energy-Student Guide. The NEED Project is a national initiative to bring innovative curriculum materials in energy education to teachers and learners from the primary grades through college.

2013-04-03

7

Photosynthesis – Life's Primary Energy Source  

NSDL National Science Digital Library

This lesson covers the process of photosynthesis and the related plant cell functions of transpiration and cellular respiration. Students will learn how engineers can use the natural process of photosynthesis as an exemplary model of a complex — yet efficient — process for converting solar energy to chemical energy or distributing water throughout a system.

Integrated Teaching and Learning Program,

8

Free Energy and Internal Combustion Engine Cycles  

E-print Network

The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.

William D. Harris

2012-01-11

9

Free Energy and Internal Combustion Engine Cycles  

E-print Network

The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.

Harris, William D

2012-01-01

10

Perceptions of the Water Cycle among Primary School Children in Botswana.  

ERIC Educational Resources Information Center

Describes qualitative and quantitative methods used to elucidate the nature of the perception of the water cycle held by Botswana primary-grade pupils in three different geographic areas. Concludes that the students' perception of the water cycle was positively influenced by schooling but negatively impacted upon, to some extent, by the untutored…

Taiwo, A. A.; Motswiri, M. J.; Masene, R.

1999-01-01

11

SQUIDSIMS is a useful approach to uncover primary signals in the Archean sulfur cycle  

E-print Network

SQUID­SIMS is a useful approach to uncover primary signals in the Archean sulfur cycle Woodward W 10, 2014 (received for review December 4, 2013) Many aspects of Earth's early sulfur cycle, from) microscopy and sec- ondary ion mass spectrometry (SIMS) of sulfur isotopes (32 S, 33 S, and 34 S), we

Fischer, Woodward

12

The Sun: Earth's Primary Energy Source  

NSDL National Science Digital Library

This article provides elementary school teachers with background knowledge about science concepts needed to understand the first of seven essential principles of climate literacy--the sun is the primary source of energy for our climate system. Graphs, diagrams, and oneline resources provide more background for the teacher. The article appears in a free online magazine that focuses on the seven essential princples of the climate sciences.

Kimberly Lightle

13

Influence of local and external processes on the annual nitrogen cycle and primary productivity on Georges Bank: A 3-D  

E-print Network

Influence of local and external processes on the annual nitrogen cycle and primary productivity.V. All rights reserved. Keywords: Nitrogen cycle; Phytoplankton productivity; Modeling; Biological., Influence of local and external processes on the annual nitrogen cycle and primary productivity on Georges

Chen, Changsheng

14

Great Lakes Ice Cycle Primary Investigator: Raymond Assel -NOAA GLERL (Emeritus)  

E-print Network

Great Lakes Ice Cycle Primary Investigator: Raymond Assel - NOAA GLERL (Emeritus) Co Board The formation, duration, and extent of ice cover on the Great Lakes has a major impact and chemistry of the lakes. The significance of reduced ice cover on the biota of the Great Lakes includes

15

MICROPLASTICITY AND ENERGY DISSIPATION IN VERY HIGH CYCLE FATIGUE  

E-print Network

1 of 3 MICROPLASTICITY AND ENERGY DISSIPATION IN VERY HIGH CYCLE FATIGUE Véronique Favier, Ngoc Lam ("Microplasticity and energy dissipation in very high cycle fatigue") is an ongoing French project financially

Boyer, Edmond

16

Pre-Service Primary Teachers' Attitudes towards Energy Conservation  

ERIC Educational Resources Information Center

This study aims to examine the pre-service primary teachers' attitudes towards energy conservation. In order to reach this main aim following research questions are formulated: (1) What are the attitude levels of pre-service primary teachers in terms of energy conservation? (2) Do pre-service primary teachers' attitudes towards energy conservation…

Tekbiyik, Ahmet; Ipek, Cemalettin

2008-01-01

17

NCESR Energy Research Grants Cycle 7 RFP Released: April 11, 2012 1 Energy Research Grants  

E-print Network

, wind energy, geothermal energy and biomass energy; and new or advanced technologies to improve energy NCESR Energy Research Grants Cycle 7 RFP ­ Released: April 11, 2012 1 Energy Research Grants Cycle 7 REQUEST FOR PROPOSAL Issue Date

Farritor, Shane

18

Energy Analysis of the Corn-Ethanol Biofuel Cycle  

E-print Network

Energy Analysis of the Corn-Ethanol Biofuel Cycle First Draft Tad W. Patzek Department of Civil legitimately ask: Why do the various energy balances of the corn-ethanol cycle still differ so much? Why do some authors claim that the corn-ethanol cycle has a positive net energy balance (Wang et al., 1997

Patzek, Tadeusz W.

19

Long-term shifts in life-cycle energy efficiency and carbon intensity.  

PubMed

The quantity of primary energy needed to support global human activity is in large part determined by how efficiently that energy is converted to a useful form. We estimate the system-level life-cycle energy efficiency (EF) and carbon intensity (CI) across primary resources for 2005-2100. Our results underscore that although technological improvements at each energy conversion process will improve technology efficiency and lead to important reductions in primary energy use, market mediated effects and structural shifts toward less efficient pathways and pathways with multiple stages of conversion will dampen these efficiency gains. System-level life-cycle efficiency may decrease as mitigation efforts intensify, since low-efficiency renewable systems with high output have much lower GHG emissions than some high-efficiency fossil fuel systems. Climate policies accelerate both improvements in EF and the adoption of renewable technologies, resulting in considerably lower primary energy demand and GHG emissions. Life-cycle EF and CI of useful energy provide a useful metric for understanding dynamics of implementing climate policies. The approaches developed here reiterate the necessity of a combination of policies that target efficiency and decarbonized energy technologies. We also examine life-cycle exergy efficiency (ExF) and find that nearly all of the qualitative results hold regardless of whether we use ExF or EF. PMID:23409918

Yeh, Sonia; Mishra, Gouri Shankar; Morrison, Geoff; Teter, Jacob; Quiceno, Raul; Gillingham, Kenneth; Riera-Palou, Xavier

2013-03-19

20

Earth's Changing Energy and Water Cycles  

NASA Astrophysics Data System (ADS)

A new assessment of the flows of energy through the climate system will be presented. It features an imbalance at the top-of-atmosphere owing to an enhanced greenhouse effect that produces global warming. Most of the surplus energy trapped increases ocean heat content. Large upwards surface thermal radiation is offset by back radiation from greenhouse gases and clouds in the atmosphere. At the surface, the net losses of energy are greatest through evapotranspiration, followed closely by net radiation, while sensible heat losses are much smaller. This highlights the vital role of the hydrological cycle and why direct changes in the water cycle are a consequence of climate change. Nonetheless, net changes in surface evaporation are fairly modest and a much larger percentage change occurs in the water-holding capacity as atmospheric temperatures increase (4% per °F). A consequence is increased water vapor in the atmosphere which feeds all storms and thus leads to more intense precipitation; increased water vapor, heavier rains and stronger storms are already observed to be happening. However, the disparity between modestly enhanced evaporation and heavier rains means decreases in frequency of precipitation and enhanced droughts. With more precipitation per unit of upward motion in the atmosphere, the atmospheric circulation weakens, causing monsoons to falter. Observed changes in Atlantic hurricanes will be used to illustrate some of these aspects. Understanding these profound consequences of climate change is especially important for water managers. In reality that includes everyone.

Trenberth, K. E.

2008-05-01

21

Life cycle assessment of high temperature electrolysis for hydrogen production via nuclear energy  

Microsoft Academic Search

A life cycle assessment (LCA) of one proposed method of hydrogen production—the high temperature electrolysis of water vapor—is presented in this paper. High temperature electrolysis offers an advantage of higher energy efficiency over the conventional low-temperature alkaline electrolysis due to reduced cell potential and consequent electrical energy requirements. The primary energy source for the electrolysis will be advanced nuclear reactors

V. Utgikar; T. Thiesen

2006-01-01

22

The Global Energy and Water Cycle Experiment (GEWEX) and Mountain Hydroclimatology  

Microsoft Academic Search

The contribution of mountains to the world's water supply is a primary motivator for research related to the effects of mountains on the distribution of moisture in the form of precipitation and runoff. The Global Energy and Water Cycle Experiment (GEWEX) places considerable emphasis on understanding and modeling terrestrial and atmospheric processes occurring in areas of complex terrain. GEWEX addresses

R. G. Lawford

2005-01-01

23

FULL FUEL CYCLE ASSESSMENT WELL TO TANK ENERGY INPUTS,  

E-print Network

FULL FUEL CYCLE ASSESSMENT WELL TO TANK ENERGY INPUTS, EMISSIONS, AND WATER IMPACTS Prepared For material increases in air or water pollution. To ensure that fair comparisons are made between the various alternative fuels, emissions from the full fuel cycle need to be considered. The full fuel cycle analysis can

24

FULL FUEL CYCLE ASSESSMENT WELL TO WHEELS ENERGY INPUTS,  

E-print Network

FULL FUEL CYCLE ASSESSMENT WELL TO WHEELS ENERGY INPUTS, EMISSIONS, AND WATER IMPACTS Preparation on a full fuel cycle basis for alternative-fueled vehicles is important when assessing the overall production are a significant portion of the total GHG emissions attributable to the full fuel cycle. Also

25

FULL FUEL CYCLE ASSESSMENT: WELL-TO-WHEELS ENERGY INPUTS,  

E-print Network

FULL FUEL CYCLE ASSESSMENT: WELL-TO-WHEELS ENERGY INPUTS, EMISSIONS, AND WATER IMPACTS STATE PLAN Waterland Stefan Unnasch FULL FUEL CYCLE ANALYSIS PEER REVIEWERS Argonne National Laboratory Michael Wang organizations were given an opportunity to review and comment on the AB 1007 full fuel cycle analysis. Comments

26

Pennsylvania's Energy Curriculum for the Primary Grades.  

ERIC Educational Resources Information Center

Presented are approximately 100 energy-related lessons for elementary school students. Among the topics addressed are the importance of energy, future energy sources, energy conservation, forms of energy, and electricity. Most activities relate to science and/or social studies and include illustrated handouts to duplicate for students. Listed in…

Pennsylvania State Dept. of Education, Harrisburg.

27

The seasonal cycle of terrestrial fluorescence and its relationship to global primary productivity (GPP)  

NASA Astrophysics Data System (ADS)

Global mapping of terrestrial vegetation fluorescence from space has recently been accomplished with the Japanese Greenhouse gases Observing SATellite (GOSAT) and other satellite sensors. These data can potentially provide global information related to the functional status of vegetation including gross primary productivity (GPP). In particular, the remotely-sensed signals may provide estimates of the length of the growing season that is potentially useful for global carbon cycle modeling. Here, we compare a satellite-derived additive signal, presumably due primarily to chlorophyll fluorescence, at 866 nm from the SCIAMACHY satellite instrument directly with a diverse set of tower-based estimates of GPP from the FluxNet and AmeriFlux networks. For some vegetation types, the SCIAMACHY signal when fluorescence is detectable at 866 nm, captures the seasonal cycle of photosynthesis. In contrast, GPP estimated with models that rely on satellite reflectance-based vegetation parameters overestimates the length of the growing season for some biomes. Satellite fluorescence measurements therefore show potential for improving model GPP estimates. Correlation between monthly-mean SCIAMACHY signal and tower GPP. Boxes show approximate averaging area of satellite data and for nearby towers are offset for clarity. Solid(dashed) outlines around boxes indicates that the primary vegetation type (IGBP) covers approximately 75-100%(50-75%) of the box; Symbols show dominant type for the box; +: Mixed Forest (MF); *: Croplands (CRO); x: Grasslands; diamond: Deciduous Broadleaf Forest (DBF)t; triangle: Evergreen Needleleaf Forest; square: savannas (including woody); circle: shrublands (open and closed). Summary of onset of photosynthetic activity for sites that are relatively homogeneous in terms of vegetation type within the satellite average area and where SCIAMACHY shows a distinct seasonal cycle.

Joiner, J.; Yoshida, Y.; Vasilkov, A. P.; Middleton, E.; Huemmrich, K. F.; Campbell, P. K.; Garrity, S. R.; Meyers, T. P.; Corp, L.; Gu, L.; Yoshida, Y.; Kuze, A.

2012-12-01

28

Open cycle ocean thermal energy conversion system  

DOEpatents

An improved open cycle ocean thermal energy conversion system including a flash evaporator for vaporizing relatively warm ocean surface water and an axial flow, elastic fluid turbine having a vertical shaft and axis of rotation. The warm ocean water is transmitted to the evaporator through a first prestressed concrete skirt-conduit structure circumferentially situated about the axis of rotation. The unflashed warm ocean water exits the evaporator through a second prestressed concrete skirt-conduit structure located circumferentially about and radially within the first skirt-conduit structure. The radially inner surface of the second skirt conduit structure constitutes a cylinder which functions as the turbine's outer casing and obviates the need for a conventional outer housing. The turbine includes a radially enlarged disc element attached to the shaft for supporting at least one axial row of radially directed blades through which the steam is expanded. A prestressed concrete inner casing structure of the turbine has upstream and downstream portions respectively situated upstream and downstream from the disc element. The radially outer surfaces of the inner casing portions and radially outer periphery of the axially interposed disc cooperatively form a downwardly radially inwardly tapered surface. An annular steam flowpath of increasing flow area in the downward axial direction is radially bounded by the inner and outer prestressed concrete casing structures. The inner casing portions each include a transversely situated prestressed concrete circular wall for rotatably supporting the turbine shaft and associated structure. The turbine blades are substantially radially coextensive with the steam flowpath and receive steam from the evaporator through an annular array of prestressed concrete stationary vanes which extend between the inner and outer casings to provide structural support therefor and impart a desired flow direction to the steam.

Wittig, J. Michael (West Goshen, PA)

1980-01-01

29

Family Life Cycle and Deforestation in Amazonia: Combining Remotely Sensed Information with Primary Data  

NASA Technical Reports Server (NTRS)

This paper examines the relationships between the socio-demographic characteristics of small settlers in the Brazilian Amazon and the life cycle hypothesis in the process of deforestation. The analysis was conducted combining remote sensing and geographic data with primary data of 153 small settlers along the TransAmazon Highway. Regression analyses and spatial autocorrelation tests were conducted. The results from the empirical model indicate that socio-demographic characteristics of households as well as institutional and market factors, affect the land use decision. Although remotely sensed information is not very popular among Brazilian social scientists, these results confirm that they can be very useful for this kind of study. Furthermore, the research presented by this paper strongly indicates that family and socio-demographic data, as well as market data, may result in misspecification problems. The same applies to models that do not incorporate spatial analysis.

Caldas, M.; Walker, R. T.; Shirota, R.; Perz, S.; Skole, D.

2003-01-01

30

Investigation of Energy Dissipation in an Ejector Refrigeration Cycle  

Microsoft Academic Search

The presented work focuses on the differences in en- ergy dissipation in each cycle component compared to the energy dissipation of the whole ejector refrigera- tion cycle. With help of this analysis, improvement of energetic efficiency by using an ejector can be set in relation to the potential improvement in efficiency of other components such as heat exchangers. Informa- tion

Christian Tischendorf; Denise Janotte; Ricardo Fiorenzano; Wilhelm Tegethoff

2009-01-01

31

Dynamic life cycle assessment (LCA) of renewable energy technologies  

Microsoft Academic Search

Before new technologies enter the market, their environmental superiority over competing options must be asserted based on a life cycle approach. However, when applying the prevailing status-quo Life Cycle Assessment (LCA) approach to future renewable energy systems, one does not distinguish between impacts which are ‘imported’ into the system due to the ‘background system’ (e.g. due to supply of materials

Martin Pehnt

2006-01-01

32

Nuclear energy center site survey: fuel cycle studies  

SciTech Connect

Background information for the Nuclear Regulatory Commission Nuclear Energy Center Site Survey is presented in the following task areas: economics of integrated vs. dispersed nuclear fuel cycle facilities, plutonium fungibility, fuel cycle industry model, production controls and failure contingencies, environmental impact, waste management, emergency response capability, and feasibility evaluations. (DG)

Not Available

1976-05-01

33

The Primary and Secondary Production of Germanium: A Life-Cycle Assessment of Different Process Alternatives  

NASA Astrophysics Data System (ADS)

Germanium is a semiconducting metalloid element used in optical fibers, catalysis, infrared optics, solar cells, and light-emitting diodes. The need for Ge in these markets is considered to increase by a steady ~1% on a yearly basis. Its economic importance, coupled with the identified supply risks, has led to the classification of germanium as a critical raw material within Europe. Since the early 1950s, Umicore Electro-Optic Materials has supplied germanium-based materials solutions to its markets around the world. Umicore extracts germanium from a wide range of refining and recycling feeds. The main objectives of this study were to quantify the potential environmental impacts of the production of germanium from production scraps from the photovoltaic industry and to compare them with the potential impacts of the primary production of germanium from coal. The data related to the secondary production are Umicore-specific data. Environmental impact scores have been calculated for the impact categories recommended by the International reference life cycle data system. The comparison of the primary and secondary production highlights the benefit linked to the recycling of metals.

Robertz, Benedicte; Verhelle, Jensen; Schurmans, Maarten

2015-02-01

34

GEWEX: The Global Energy and Water Cycle Experiment  

NASA Technical Reports Server (NTRS)

GEWEX is one of the world's largest global change research programs. Its purpose is to observe and understand the hydrological cycle and energy fluxes in the atmosphere, at land surfaces and in the upper oceans.

Chahine, M.; Vane, D.

1994-01-01

35

Gallery Walk Questions about Energy and Material Cycles  

NSDL National Science Digital Library

created by Mark Francek, Central Michigan University The following are potential questions that could be used in a gallery walk activity about energy and material cycles. The questions are organized according to ...

36

Primary energy: Present status and future perspectives  

NASA Astrophysics Data System (ADS)

A survey of the base-load energy sources available to humans is presented, starting from the point of view that all energy used is ultimately derived from nuclear processes within the sun. Specific note is made of European energy options, noting the large dependence on imported oil. Detailed exploration of available nuclear fuel resources is carried out, with attention given to fission, fusion, and breeder reactor plants and to the state-of-the-art and technology for each. The problems of nuclear waste disposal are discussed, and long term burial in salt domes is outlined as a satisfactory method of containing the materials for acceptable periods of time. The CO2-greenhouse effect hazards caused by increased usage of coal-derived fuels are considered and precautions to be taken on a global scale to ameliorate the warming effects are recommended. The limitations to hydropower are examined, as are those of tidal power. Solar cells are projected to be produced in GW quantities by the year 2000, while wind-derived electricity is predicted to provide a minimum of 5% of the world energy needs in the future.

Thielheim, K. O.

37

Energy analysis of electric vehicles using batteries or fuel cells through well-to-wheel driving cycle simulations  

Microsoft Academic Search

This work presents a study of the energy and environmental balances for electric vehicles using batteries or fuel cells, through the methodology of the well to wheel (WTW) analysis, applied to ECE-EUDC driving cycle simulations.Well to wheel balances are carried out considering different scenarios for the primary energy supply. The fuel cell electric vehicles (FCEV) are based on the polymer

Stefano Campanari; Giampaolo Manzolini; Fernando Garcia de la Iglesia

2009-01-01

38

Life cycle energy impacts of automotive liftgate inner  

Microsoft Academic Search

This paper compares the life cycle energy use of a cast-aluminum, rear liftgate inner and a conventional, stamped steel liftgate inner used in a minivan. Using the best available aggregate life cycle inventory data and a simple spreadsheet-level analysis, energy comparisons were made at both the single-vehicle and vehicle-fleet levels. Since the product manufacture and use are distributed over long

Sujit Das

2005-01-01

39

Cycle-accurate simulation of energy consumption in embedded systems  

Microsoft Academic Search

This paper presents a methodology for cycle-accurate simulationof energy dissipation in embedded systems. TheARM Ltd. [1] instruction-level cycle-accurate simulator isextended with energy models for the processor, the L2 cache,the memory, the interconnect and the DC-DC converter. ASmartBadge, which can be seen as an embedded system consistingof StrongARM-1100 processor, memory and the DCDCconverter, is used to evaluate the methodology with theDhrystone

Tajana Šimuni?; Luca Benini; Giovanni De Micheli

1999-01-01

40

On the free energy of the solar cycles  

Microsoft Academic Search

The free energy transformations leading to the observed solar cycle variations of the total solar irradiance are not known. The energy of magnetic fields and their dissipation related to the solar activity manifestations in large scale structures on the Sun do not look to be sufficient energy reservoirs and channels for producing the total solar radiation variations with the relative

I. S Veselovsky

2004-01-01

41

Sharp knee phenomenon of primary cosmic ray energy spectrum  

NASA Astrophysics Data System (ADS)

Primary energy spectral models are tested in the energy range of 1-200 PeV using standardized extensive air shower responses from BASJE-MAS, Tibet, GAMMA and KASCADE scintillation shower arrays. Results point toward the two-component origin of observed cosmic ray energy spectra in the knee region consisting of a pulsar component superimposed upon rigidity-dependent power law diffuse Galactic flux. The two-component energy spectral model accounts for both the sharp knee shower spectral phenomenon and observed irregularity of all-particle energy spectrum in the region of 50-100 PeV. Alternatively, tested multipopulation primary energy spectra predicted by nonlinear diffusive shock acceleration models describe observed shower spectra in the knee region provided that the cutoff magnetic rigidities of accelerating particles are 6±0.3 and 45±2 PV for the first two populations, respectively. Both tested spectral models confirm the predominant H-He primary nuclei origin of observed shower spectral knee. The parameters of tested energy spectra are evaluated using solutions of the inverse problem on the basis of the corresponding parameterizations of energy spectra for primary H, He, O-like and Fe-like nuclei, standardized shower size spectral responses in the 550-1085 g/cm2 atmospheric slant depth range and near vertical muon truncated size spectra detected by the GAMMA array.

Ter-Antonyan, Samvel

2014-06-01

42

EFFECT OF ARSENICALS ON THE EXPRESSION OF CELL CYCLE PROTEINS AND EARLY SIGNALING EVENTS IN PRIMARY HUMAN KERATINOCYTES.  

EPA Science Inventory

Effect of Arsenicals on the Expression of Cell Cycle Proteins and Early Signaling Events in Primary Human Keratinocytes. Mudipalli, A, Owen R. D. and R. J. Preston, Environmental Carcinogenesis Division, USEPA, RTP, NC 27711. Environmental exposure to arsenic is a m...

43

Performance analysis and modeling of energy from waste combined cycles  

Microsoft Academic Search

Municipal solid waste (MSW) is produced in a substantial amount with minimal fluctuations throughout the year. The analysis of carbon neutrality of MSW on a life cycle basis shows that MSW is about 67% carbon-neutral, suggesting that only 33% of the CO2 emissions from incinerating MSW are of fossil origin. The waste constitutes a “renewable biofuel” energy resource and energy

K. Qiu; A. C. S. Hayden

2009-01-01

44

Energy Demand in China (Carbon Cycle 2.0)  

SciTech Connect

Lynn Price, LBNL scientist, speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 2, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

Price, Lynn

2010-02-02

45

Energy Demand in China (Carbon Cycle 2.0)  

ScienceCinema

Lynn Price, LBNL scientist, speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 2, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

Price, Lynn

2011-06-08

46

Life Cycle Energy and Environmental Assessment of Aluminum-Intensive Vehicle Design  

SciTech Connect

Advanced lightweight materials are increasingly being incorporated into new vehicle designs by automakers to enhance performance and assist in complying with increasing requirements of corporate average fuel economy standards. To assess the primary energy and carbon dioxide equivalent (CO2e) implications of vehicle designs utilizing these materials, this study examines the potential life cycle impacts of two lightweight material alternative vehicle designs, i.e., steel and aluminum of a typical passenger vehicle operated today in North America. LCA for three common alternative lightweight vehicle designs are evaluated: current production ( Baseline ), an advanced high strength steel and aluminum design ( LWSV ), and an aluminum-intensive design (AIV). This study focuses on body-in-white and closures since these are the largest automotive systems by weight accounting for approximately 40% of total curb weight of a typical passenger vehicle. Secondary mass savings resulting from body lightweighting are considered for the vehicles engine, driveline and suspension. A cradle-to-cradle life cycle assessment (LCA) was conducted for these three vehicle material alternatives. LCA methodology for this study included material production, mill semi-fabrication, vehicle use phase operation, and end-of-life recycling. This study followed international standards ISO 14040:2006 [1] and ISO 14044:2006 [2], consistent with the automotive LCA guidance document currently being developed [3]. Vehicle use phase mass reduction was found to account for over 90% of total vehicle life cycle energy and CO2e emissions. The AIV design achieved mass reduction of 25% (versus baseline) resulting in reductions in total life cycle primary energy consumption by 20% and CO2e emissions by 17%. Overall, the AIV design showed the best breakeven vehicle mileage from both primary energy consumption and climate change perspectives.

Das, Sujit [ORNL

2014-01-01

47

Determining the life cycle energy efficiency of six biofuel systems in China: a Data Envelopment Analysis.  

PubMed

This aim of this study was to use Data Envelopment Analysis (DEA) to assess the life cycle energy efficiency of six biofuels in China. DEA can differentiate efficient and non-efficient scenarios, and it can identify wasteful energy losses in biofuel production. More specifically, the study has examined the efficiency of six approaches for bioethanol production involving a sample of wheat, corn, cassava, and sweet potatoes as feedstocks and "old," "new," "wet," and "dry" processes. For each of these six bioethanol production pathways, the users can determine energy inputs such as the embodied energy for seed, machinery, fertilizer, diesel, chemicals and primary energy utilized for manufacturing, and outputs such as the energy content of the bioethanol and byproducts. The results indicate that DEA is a novel and feasible method for finding efficient bioethanol production scenarios and suggest that sweet potatoes may be the most energy-efficient form of ethanol production for China. PMID:24727398

Ren, Jingzheng; Tan, Shiyu; Dong, Lichun; Mazzi, Anna; Scipioni, Antonio; Sovacool, Benjamin K

2014-06-01

48

The Flow of Energy: Primary Production to Higher Trophic Levels  

NSDL National Science Digital Library

Today we will explore some of the multiple topics related to the flow of energy in ecosystems. Energy is used up and lost as heat as it moves through ecosystems, and new energy is continually added to the earth in the form of solar radiation. As we learned in the last lecture, the earth is an open system in regard to energy.Nutrients and other materials, on the other hand, are continually recirculated within and among ecosystems, and by and large there are no new inputs or losses from the planet. In terms of materials, then, the earth is a closed system. Both energy and materials are essential to ecosystem structure, function, and composition. You have already been exposed to the basic concepts of nutrient cycles; in this lecture we focus on energy. Note that in terms of the cycling of carbon, "materials" and energy can be inter-converted. For example, we know how many calories (a measure of energy) a gram of certain carbon compounds materials such as fats or carbohydrates contain.

Klink, George

49

Isoprene emissions track the seasonal cycle of canopy temperature, not primary production: evidence from remote sensing  

NASA Astrophysics Data System (ADS)

Isoprene is important in atmospheric chemistry, but its seasonal emission pattern - especially in the tropics, where most isoprene is emitted - is incompletely understood. We set out to discover generalized relationships applicable across many biomes between large-scale isoprene emission and a series of potential predictor variables, including both observed and model-estimated variables related to gross primary production (GPP) and canopy temperature. We used remotely sensed atmospheric concentrations of formaldehyde, an intermediate oxidation product of isoprene, as a proxy for isoprene emission in 22 regions selected to span high to low latitudes, to sample major biomes, and to minimize interference from pyrogenic sources of volatile organic compounds that could interfere with the isoprene signal. Formaldehyde concentrations showed the highest average seasonal correlations with remotely sensed (r = 0.85) and model-estimated (r = 0.80) canopy temperatures. Both variables predicted formaldehyde concentrations better than air temperature (r= 0.56) and a "reference" isoprene model that combines GPP and an exponential function of temperature (r = 0.49), and far better than either remotely sensed green vegetation cover, fPAR (r = 0.25) or model-estimated GPP (r = 0.14). Gross primary production in tropical regions was anti-correlated with formaldehyde concentration (r = -0.30), which peaks during the dry season. Our results were most reliable in the tropics, where formaldehyde observational errors were the least. The tropics are of particular interest because they are the greatest source of isoprene emission as well as the region where previous modelling attempts have been least successful. We conjecture that positive correlations of isoprene emission with GPP and air temperature (as found in temperate forests) may arise simply because both covary with canopy temperature, peaking during the relatively short growing season. The lack of a general correlation between GPP and formaldehyde concentration in the seasonal cycle is consistent with experimental evidence that isoprene emission rates are largely decoupled from photosynthetic rates, and with the likely adaptive significance of isoprene emission in protecting leaves against heat damage and oxidative stress.

Foster, P. N.; Prentice, I. C.; Morfopoulos, C.; Siddall, M.; van Weele, M.

2014-07-01

50

Isoprene emissions track the seasonal cycle of canopy temperature, not primary production: evidence from remote sensing  

NASA Astrophysics Data System (ADS)

Isoprene is important in atmospheric chemistry, but its seasonal emission pattern - especially in the tropics, where most isoprene is emitted - is incompletely understood. We set out to discover general, biome-independent relationships between large-scale isoprene emission and a series of potential predictor variables, including both observed and model-estimated variables related to gross primary production (GPP) and canopy temperature. To this end we used remotely sensed atmospheric concentrations of formaldehyde, an intermediate oxidation product of isoprene, as a proxy for isoprene emission in 22 regions selected to span high to low latitudes, to sample major biomes, and to minimize interference from pyrogenic sources of volatile organic compounds that could interfere with the isoprene signal. Formaldehyde concentrations showed the highest average seasonal correlations with remotely sensed (r = 0.85) and model-estimated (r = 0.80) canopy temperatures. Both variables predicted formaldehyde concentrations better than air temperature (r = 0.56) and a "reference" isoprene model that includes both temperature and GPP (r = 0.49), and far better than either remotely sensed green vegetation cover (r = 0.25) or model-estimated GPP (r = 0.14). GPP in tropical regions was anti-correlated with formaldehyde concentration (r = -0.30), which peaks during the dry season. We conjecture that the positive correlations of isoprene emission with primary production, and with air temperature, found in temperate forest regions arise simply because all three peak during the relatively short growing season. In most tropical regions, where the seasonal cycles of GPP and canopy temperature are very different, isoprene emission is revealed to depend on canopy temperature but not at all on GPP. The lack of a general correlation between GPP and formaldehyde concentration is consistent with experimental evidence that isoprene emission is decoupled from photosynthesis, and with the likely adaptive significance of isoprene emission in protecting leaves against heat damage and oxidative stress. In contrast, the high correlation between canopy temperature and formaldehyde concentration indicates the importance of including canopy temperature explicitly in large-scale models.

Foster, P. N.; Prentice, I. C.; Morfopoulos, C.; Siddall, M.; van Weele, M.

2013-12-01

51

Sharp knee phenomenon of primary cosmic ray energy spectrum  

E-print Network

Primary energy spectral models are tested in the energy range of 1-200 PeV using standardized extensive air shower responses from BASJE-MAS, Tibet, GAMMA and KASCADE scintillation shower arrays. Results point towards the two-component origin of observed cosmic ray energy spectra in the knee region (GAPS spectral model) consisting of a pulsar component superimposed upon rigidity-dependent power law diffuse galactic flux. The two-component energy spectral model accounts for both the sharp knee shower spectral phenomenon and observed irregularity of all-particle energy spectrum in the region of 50-100 PeV. Alternatively, tested multi-population primary energy spectra predicted by non-linear diffusive shock acceleration (DSA) models describe observed shower spectra in the knee region provided that the cutoff magnetic rigidities of accelerating particles are 6.0+/-0.3 PV and 45+/-2 PV for the first two populations respectively. Both tested spectral models confirm the predominant H-He primary nuclei origin of obser...

Ter-Antonyan, Samvel

2014-01-01

52

A combined power cycle using refuse incineration and LNG cold energy  

Microsoft Academic Search

The objectives of this paper are to develop a combined power generation cycle using refuse incineration and LNG cold energy, and to conduct parametric analysis to investigate the effects of key parameters on the thermal and exergy efficiencies. The combined cycle consists of an ammonia–water Rankine cycle with refuse incinerator and a LNG cold energy cycle. The combined cycle is

T Miyazaki; Y. T Kang; A Akisawa; T Kashiwagi

2000-01-01

53

Consideration of black carbon and primary organic carbon emissions in life-cycle analysis of Greenhouse gas emissions of vehicle systems and fuels.  

PubMed

The climate impact assessment of vehicle/fuel systems may be incomplete without considering short-lived climate forcers of black carbon (BC) and primary organic carbon (POC). We quantified life-cycle BC and POC emissions of a large variety of vehicle/fuel systems with an expanded Greenhouse gases, Regulated Emissions, and Energy use in Transportation model developed at Argonne National Laboratory. Life-cycle BC and POC emissions have small impacts on life-cycle greenhouse gas (GHG) emissions of gasoline, diesel, and other fuel vehicles, but would add 34, 16, and 16 g CO2 equivalent (CO2e)/mile, or 125, 56, and 56 g CO2e/mile with the 100 or 20 year Global Warming Potentials of BC and POC emissions, respectively, for vehicles fueled with corn stover-, willow tree-, and Brazilian sugarcane-derived ethanol, mostly due to BC- and POC-intensive biomass-fired boilers in cellulosic and sugarcane ethanol plants for steam and electricity production, biomass open burning in sugarcane fields, and diesel-powered agricultural equipment for biomass feedstock production/harvest. As a result, life-cycle GHG emission reduction potentials of these ethanol types, though still significant, are reduced from those without considering BC and POC emissions. These findings, together with a newly expanded GREET version, help quantify the previously unknown impacts of BC and POC emissions on life-cycle GHG emissions of U.S. vehicle/fuel systems. PMID:25259852

Cai, Hao; Wang, Michael Q

2014-10-21

54

A Satellite View of Global Water and Energy Cycling  

NASA Astrophysics Data System (ADS)

The global water cycle describes liquid, solid and vapor water dynamics as it moves through the atmosphere, oceans and land. Life exists because of water, and civilization depends on adapting to the constraints imposed by water availability. The carbon, water and energy cycles are strongly interdependent - energy is moved through evaporation and condensation, and photosynthesis is closely related to transpiration. There are significant knowledge gaps about water storage, fluxes and dynamics - we currently do not really know how much water is stored in snowpacks, groundwater or reservoirs. The view from space offers a vision for water science advancement. This vision includes observation, understanding, and prediction advancements that will improve water management and to inform water-related infrastructure that planning to provide for human needs and to protect the natural environment. The water cycle science challenge is to deploy a series of coordinated earth observation satellites, and to integrate in situ and space-borne observations to quantify the key water-cycle state variables and fluxes. The accompanying societal challenge is to integrate this information along with water cycle physics, and ecosystems and societal considerations as a basis for enlightened water resource management and to protect life and property from effects of water cycle extremes. Better regional to global scale water-cycle observations and predictions need to be readily available to reduce loss of life and property caused by water-related hazards. To this end, the NASA Energy and Water cycle Study (NEWS) has been documenting the satellite view of the water cycle with a goal of enabling improved, observationally based, predictions of water and energy cycle consequences of Earth system variability and change. NEWS has fostered broad interdisciplinary collaborations to study experimental and operational satellite observations and has developed analysis tools for characterizing air/sea fluxes, ocean circulation, atmospheric states, radiative balances, land surface states, sub-surface hydrology, snow and ice. This presentation will feature an overview of recent progress towards this challenge, and lay out the plan for coordination with complementary international efforts.

Houser, P. R.

2012-12-01

55

SQUID-SIMS is a useful approach to uncover primary signals in the Archean sulfur cycle.  

PubMed

Many aspects of Earth's early sulfur cycle, from the origin of mass-anomalous fractionations to the degree of biological participation, remain poorly understood--in part due to complications from postdepositional diagenetic and metamorphic processes. Using a combination of scanning high-resolution magnetic superconducting quantum interference device (SQUID) microscopy and secondary ion mass spectrometry (SIMS) of sulfur isotopes ((32)S, (33)S, and (34)S), we examined drill core samples from slope and basinal environments adjacent to a major Late Archean (?2.6-2.5 Ga) marine carbonate platform from South Africa. Coupled with petrography, these techniques can untangle the complex history of mineralization in samples containing diverse sulfur-bearing phases. We focused on pyrite nodules, precipitated in shallow sediments. These textures record systematic spatial differences in both mass-dependent and mass-anomalous sulfur-isotopic composition over length scales of even a few hundred microns. Petrography and magnetic imaging demonstrate that mass-anomalous fractionations were acquired before burial and compaction, but also show evidence of postdepositional alteration 500 million y after deposition. Using magnetic imaging to screen for primary phases, we observed large spatial gradients in ?(33)S (>4‰) in nodules, pointing to substantial environmental heterogeneity and dynamic mixing of sulfur pools on geologically rapid timescales. In other nodules, large systematic radial ?(34)S gradients (>20‰) were observed, from low values near their centers increasing to high values near their rims. These fractionations support hypotheses that microbial sulfate reduction was an important metabolism in organic-rich Archean environments--even in an Archean ocean basin dominated by iron chemistry. PMID:24706767

Fischer, Woodward W; Fike, David A; Johnson, Jena E; Raub, Timothy D; Guan, Yunbin; Kirschvink, Joseph L; Eiler, John M

2014-04-15

56

SQUID–SIMS is a useful approach to uncover primary signals in the Archean sulfur cycle  

PubMed Central

Many aspects of Earth’s early sulfur cycle, from the origin of mass-anomalous fractionations to the degree of biological participation, remain poorly understood—in part due to complications from postdepositional diagenetic and metamorphic processes. Using a combination of scanning high-resolution magnetic superconducting quantum interference device (SQUID) microscopy and secondary ion mass spectrometry (SIMS) of sulfur isotopes (32S, 33S, and 34S), we examined drill core samples from slope and basinal environments adjacent to a major Late Archean (?2.6–2.5 Ga) marine carbonate platform from South Africa. Coupled with petrography, these techniques can untangle the complex history of mineralization in samples containing diverse sulfur-bearing phases. We focused on pyrite nodules, precipitated in shallow sediments. These textures record systematic spatial differences in both mass-dependent and mass-anomalous sulfur-isotopic composition over length scales of even a few hundred microns. Petrography and magnetic imaging demonstrate that mass-anomalous fractionations were acquired before burial and compaction, but also show evidence of postdepositional alteration 500 million y after deposition. Using magnetic imaging to screen for primary phases, we observed large spatial gradients in ?33S (>4‰) in nodules, pointing to substantial environmental heterogeneity and dynamic mixing of sulfur pools on geologically rapid timescales. In other nodules, large systematic radial ?34S gradients (>20‰) were observed, from low values near their centers increasing to high values near their rims. These fractionations support hypotheses that microbial sulfate reduction was an important metabolism in organic-rich Archean environments—even in an Archean ocean basin dominated by iron chemistry. PMID:24706767

Fischer, Woodward W.; Fike, David A.; Johnson, Jena E.; Raub, Timothy D.; Guan, Yunbin; Kirschvink, Joseph L.; Eiler, John M.

2014-01-01

57

Life cycle analysis of energy systems: Methods and experience  

SciTech Connect

Fuel-cycle analysis if not the same as life-cycle analysis, although the focus on defining a comprehensive system for analysis leads toward the same path. This approach was the basis of the Brookhaven Reference Energy System. It provided a framework for summing total effects over an explicitly defined fuel cycle. This concept was computerized and coupled with an extensive data base in ESNS -- the Energy Systems Network Simulator. As an example, ESNS was the analytical basis for a comparison of health and environmental effects of several coal conversion technologies. With advances in computer systems and methods, however, ESNS has not been maintained at Brookhaven. The RES approach was one of the bases of the OECD COMPASS Project and the UNEP comparative assessment of environmental impacts of energy sources. An RES model alone has limitations in analyzing complex energy systems, e.g., it is difficult to handle feedback in the network. The most recent version of a series of optimization models is MARKAL, a dynamic linear programming model now used to assess strategies to reduce greenhouse gas emissions from the energy system. MARKAL creates an optimal set of reference energy systems over multiple time periods, automatically incorporating dynamic feedback and allowing fuel switching and end-use conservation to meet useful energy demands.

Morris, S.C.

1992-01-01

58

Life cycle analysis of energy systems: Methods and experience  

SciTech Connect

Fuel-cycle analysis if not the same as life-cycle analysis, although the focus on defining a comprehensive system for analysis leads toward the same path. This approach was the basis of the Brookhaven Reference Energy System. It provided a framework for summing total effects over an explicitly defined fuel cycle. This concept was computerized and coupled with an extensive data base in ESNS -- the Energy Systems Network Simulator. As an example, ESNS was the analytical basis for a comparison of health and environmental effects of several coal conversion technologies. With advances in computer systems and methods, however, ESNS has not been maintained at Brookhaven. The RES approach was one of the bases of the OECD COMPASS Project and the UNEP comparative assessment of environmental impacts of energy sources. An RES model alone has limitations in analyzing complex energy systems, e.g., it is difficult to handle feedback in the network. The most recent version of a series of optimization models is MARKAL, a dynamic linear programming model now used to assess strategies to reduce greenhouse gas emissions from the energy system. MARKAL creates an optimal set of reference energy systems over multiple time periods, automatically incorporating dynamic feedback and allowing fuel switching and end-use conservation to meet useful energy demands.

Morris, S.C.

1992-08-01

59

Life-cycle energy and greenhouse gas emission benefits of lightweighting in automobiles: review and harmonization.  

PubMed

Replacing conventional materials (steel and iron) with lighter alternatives (e.g., aluminum, magnesium, and composites) decreases energy consumption and greenhouse gas (GHG) emissions during vehicle use but may increase energy consumption and GHG emissions during vehicle production. There have been many life cycle assessment (LCA) studies on the benefits of vehicle lightweighting, but the wide variety of assumptions used makes it difficult to compare results from the studies. To clarify the benefits of vehicle lightweighting we have reviewed the available literature (43 studies). The GHG emissions and primary energy results from 33 studies that passed a screening process were harmonized using a common set of assumptions (lifetime distance traveled, fuel-mass coefficient, secondary weight reduction factor, fuel consumption allocation, recycling rate, and energy intensity of materials). After harmonization, all studies indicate that using aluminum, glass-fiber reinforced plastic, and high strength steel to replace conventional steel decreases the vehicle life cycle energy use and GHG emissions. Given the flexibility in options implied by the variety of materials available and consensus that these materials have substantial energy and emissions benefits, it seems likely that lightweighting will be used increasingly to improve fuel economy and reduce life cycle GHG emissions from vehicles. PMID:23668335

Kim, Hyung Chul; Wallington, Timothy J

2013-06-18

60

Energy spectra and composition of primary cosmic rays  

NASA Astrophysics Data System (ADS)

New results are described on the energy spectra and relative abundances of primary cosmic ray nuclei from carbon to iron. The measurement was performed on the Spacelab-2 mission of the Space Shuttle Challenger in 1985, and extends to energies beyond 1 TeV per amu. The data indicate that the cosmic ray flux arriving near earth becomes enriched with heavier nuclei, most notably iron, as energy increases. Extrapolating to the source, with a simple leaky box model of galactic propagation with rigidity-dependent containment time, relative abundances of the elements are obtained that are quite similar to those reported at lower energy. In particular, the depletion of elements with high first ionization potential relative to the local galactic abundances, seems to persist in the cosmic ray source well up to TeV energies. A single power-law energy spectrum about E exp -2.1 provides a good description of the observed spectra of most elemental species.

Mueller, Dietrich; Swordy, Simon P.; Meyer, Peter; L'Heureux, Jacques; Grunsfeld, John M.

1991-06-01

61

Carbon Cycle 2.0: Nitash Balsara: Energy Storage  

SciTech Connect

Feb. 4, 2010: Humanity emits more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future.

Nitash Balsara

2010-02-16

62

Carbon Cycle 2.0: Nitash Balsara: Energy Storage  

ScienceCinema

Feb. 4, 2010: Humanity emits more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future.

Nitash Balsara

2010-09-01

63

GEWEX: The Global Energy and Water Cycle Experiment  

Microsoft Academic Search

The need for better quantitative understanding of energy fluxes and water exchanges is basic to all climate studies, yet our quantitative knowledge of the global hydrological cycle remains surprisingly poor. Evaporation minus precipitation or, similarly, the net flow of water from land to oceans and the net advection of moisture from the marine atmosphere to the terrestrial atmosphere is known

Moustafa T. Chahine

1992-01-01

64

Solar energy powered Rankine cycle using supercritical CO 2  

Microsoft Academic Search

A solar energy powered Rankine cycle using supercritical CO2 for combined production of electricity and thermal energy is proposed. The proposed system consists of evacuated solar collectors, power generating turbine, high-temperature heat recovery system, low-temperature heat recovery system, and feed pump. The system utilizes evacuated solar collectors to convert CO2 into high-temperature supercritical state, used to drive a turbine and

H. Yamaguchi; X. R. Zhang; K. Fujima; M. Enomoto; N. Sawada

2006-01-01

65

A novel thermomechanical energy conversion cycle Ian M. McKinley, Felix Y. Lee, Laurent Pilon  

E-print Network

, refrigeration, and heat pump cycles, according to the second law of thermodynamics [2]. In fact, many sourcesA novel thermomechanical energy conversion cycle Ian M. McKinley, Felix Y. Lee, Laurent Pilon of a novel cycle converting thermal and mechanical energy directly into electrical energy. The new cycle

Pilon, Laurent

66

Life cycle energy requirements and greenhouse gas emissions from large scale energy storage systems  

Microsoft Academic Search

Using life cycle assessment, metrics for calculation of the input energy requirements and greenhouse gas emissions from utility scale energy storage systems have been developed and applied to three storage technologies: pumped hydro storage (PHS), compressed air energy storage (CAES) and advanced battery energy storage (BES) using vanadium and sodium polysulphide electrolytes. In general, the use of energy storage with

Paul Denholm; Gerald L. Kulcinski

2004-01-01

67

Low Cost Solar Energy Conversion (Carbon Cycle 2.0)  

SciTech Connect

Ramamoorthy Ramesh from LBNL's Materials Science Division speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 2, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

Ramesh, Ramamoorthy

2010-02-04

68

Low Cost Solar Energy Conversion (Carbon Cycle 2.0)  

ScienceCinema

Ramamoorthy Ramesh from LBNL's Materials Science Division speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 2, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

Ramesh, Ramamoorthy

2011-06-08

69

Carbon nanofiber polymer composites: evaluation of life cycle energy use.  

PubMed

Holistic evaluation of emerging nanotechnologies using systems analysis is pivotal for guiding their safe and sustainable development. While toxicity studies of engineered nanomaterials are essential, understanding of the potential large scale impacts of nanotechnology is also critical for developing sustainable nanoproducts. This work evaluates the life cycle energetic impact associated with the production and use of carbon nanofiber (CNF) reinforced polymer nanocomposites (PNC). Specifically, both simple CNF and carbon nanofiber-glass fiber (CNF-GF) hybrid PNCs are evaluated and compared with steel for equal stiffness design. Life cycle inventory is developed based on published literature and best available engineering information. A cradle-to-gate comparison suggests that for equal stiffness design, CNF reinforced PNCs are 1.6-12 times more energy intensive than steel. It is anticipated that the product use phase may strongly influence whether any net savings in life cycle energy consumption can be realized. A case study involving the use of CNF and CNF-GF reinforced PNCs in the body panels of automobiles highlights that the use of PNCs with lower CNF loading ratios has the potential for net life cycle energy savings relative to steel owing to improved fuel economy benefits. Other factors such as cost, toxicity impact of CNF, and end-of-life issues specific to CNFs need to be considered to evaluate the final economic and environmental performance of CNF reinforced PNC materials. PMID:19368217

Khanna, Vikas; Bakshi, Bhavik R

2009-03-15

70

Battery energy storage systems life cycle costs case studies  

SciTech Connect

This report presents a comparison of life cycle costs between battery energy storage systems and alternative mature technologies that could serve the same utility-scale applications. Two of the battery energy storage systems presented in this report are located on the supply side, providing spinning reserve and system stability benefits. These systems are compared with the alternative technologies of oil-fired combustion turbines and diesel generators. The other two battery energy storage systems are located on the demand side for use in power quality applications. These are compared with available uninterruptible power supply technologies.

Swaminathan, S.; Miller, N.F.; Sen, R.K. [SENTECH, Inc., Bethesda, MD (United States)

1998-08-01

71

High energy primary electron spectrum observed by the emulsion chamber  

NASA Technical Reports Server (NTRS)

A detector of the emulsion chamber type is used to measure the energy spectrum of cosmic-ray electrons. Two large emulsion chambers, each having an area of 40 by 50 sq cm, are exposed for about 25.5 hr at an average pressure altitude of 3.9 mbar. About 500 high-energy cascades (no less than about 600 GeV) are detected by searching for dark spots on the X-ray films. A power-law energy dependence formula is derived for the spectrum of primary cosmic-ray electrons in the energy region over 100 GeV. The results are in good agreement with the transition curves obtained previously by theoretical and Monte Carlo calculations.

Nishimura, J.; Fujii, M.; Aizu, H.; Hiraiwa, N.; Taira, T.; Kobayashi, T.; Niu, K.; Koss, T. A.; Lord, J. J.; Golden, R. L.

1978-01-01

72

Composition of Primary Cosmic-Ray Nuclei at High Energies  

E-print Network

The TRACER instrument (``Transition Radiation Array for Cosmic Energetic Radiation'') has been developed for direct measurements of the heavier primary cosmic-ray nuclei at high energies. The instrument had a successful long-duration balloon flight in Antarctica in 2003. The detector system and measurement process are described, details of the data analysis are discussed, and the individual energy spectra of the elements O, Ne, Mg, Si, S, Ar, Ca, and Fe (nuclear charge Z=8 to 26) are presented. The large geometric factor of TRACER and the use of a transition radiation detector make it possible to determine the spectra up to energies in excess of 10$^{14}$ eV per particle. A power-law fit to the individual energy spectra above 20 GeV per amu exhibits nearly the same spectral index ($\\sim$ 2.65 $\\pm$ 0.05) for all elements, without noticeable dependence on the elemental charge Z.

M. Ave; P. J. Boyle; F. Gahbauer; C. Hoppner; J. R. Horandel; M. Ichimura; D. Muller; A. Romero-Wolf

2008-01-03

73

Renewable energy from the sea - organic Rankine Cycle using ocean thermal energy conversion  

Microsoft Academic Search

Rankine cycles using refrigerant- and benzene-series fluids as working fluids in converting low-grade energy from renewable energy resources such as solar energy and ocean thermal energy were investigated in this study. The main purpose is to verify the feasibility of utilizing ocean energy (i.e., ocean thermal energy conversion, OTEC) which can also be combined with solar energy in an organic

S. K. Wang; T. C. Hung

2010-01-01

74

Wood energy fuel cycle optimization in beech and spruce forests  

NASA Astrophysics Data System (ADS)

A novel synergistic approach to reducing emissions from residential wood combustion (RWC) is presented. Wood energy fuel cycle optimization (FCO) aims to provide cleaner burning fuels through optimization of forestry and renewable energy management practices. In this work, beech and spruce forests of average and high quality were modelled and analysed to determine the volume of fuel wood and its associated bark fraction produced during typical forestry cycles. Two separate fuel wood bark production regimes were observed for beech trees, while only one production regime was observed for spruce. The single tree and stand models were combined with existing thinning parameters to replicate existing management practices. Utilizing estimates of initial seedling numbers and existing thinning patterns a dynamic model was formed that responded to changes in thinning practices. By varying the thinning parameters, this model enabled optimization of the forestry practices for the reduction of bark impurities in the fuel wood supply chain. Beech forestry cycles responded well to fuel cycle optimization with volume reductions of bark from fuel wood of between ˜10% and ˜20% for average and high quality forest stands. Spruce, on the other hand, was fairly insensitive to FCO with bark reductions of 0-5%. The responsiveness of beech to FCO further supports its status as the preferred RWC fuel in Switzerland. FCO could easily be extended beyond Switzerland and applied across continental Europe and North America.

Meyer, Nickolas K.; Mina, Marco

2012-03-01

75

Energy and wate cycles in the climate system  

SciTech Connect

This report is volume 5 in the NATO ASI Series 1: Global Environmental Change. It is specifically aimed at addressing research status and goals of GEWEX (Global Energy and Water Cycle Experiment) and represents presentations made to the NATO Advanced Study Institute at meetings held in Glucksburg, Germany, in September-October 1991. The volume is organized around 15 chapters presented by authors located primarily at western European research institutes and universities. Although this is not explicitly stated, the book is organized around three identifiable themes. Theme one comprises eight chapters and is generally concerned with the global scale. Theme two includes four chapters dealing with the role of oceans in the global energy and water cycle. The third theme, covering three chapters, treats the terrestrial environment. There are also two appendices, the first discussing databases for GEWEX and the second a summary of contributions to the conference made in poster sessions.

Raschke, E.; Jacob, D. (eds.)

1993-01-01

76

Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 2: Advanced energy conversion systems. Part 1: Open-cycle gas turbines  

NASA Technical Reports Server (NTRS)

Ten energy conversion systems are defined and analyzed in terms of efficiency. These include: open-cycle gas turbine recuperative; open-cycle gas turbine; closed-cycle gas turbine; supercritical CO2 cycle; advanced steam cycle; liquid metal topping cycle; open-cycle MHD; closed-cycle inert gas MHD; closed-cycle liquid metal MHD; and fuel cells. Results are presented.

Brown, D. H.; Corman, J. C.

1976-01-01

77

Energy recovery system using an organic rankine cycle  

DOEpatents

A thermodynamic system for waste heat recovery, using an organic rankine cycle is provided which employs a single organic heat transferring fluid to recover heat energy from two waste heat streams having differing waste heat temperatures. Separate high and low temperature boilers provide high and low pressure vapor streams that are routed into an integrated turbine assembly having dual turbines mounted on a common shaft. Each turbine is appropriately sized for the pressure ratio of each stream.

Ernst, Timothy C

2013-10-01

78

Indonesian residential high rise buildings: A life cycle energy assessment  

Microsoft Academic Search

This study evaluates the effect of building envelopes on the life cycle energy consumption of high rise residential buildings in Jakarta, Indonesia. For high rise residential buildings, the enclosures contribute 10–50% of the total building cost, 14–17% of the total material mass and 20–30% of the total heat gain. The direct as well as indirect influence of the envelope materials

Agya Utama; Shabbir H. Gheewala

2009-01-01

79

Outflow of low-energy ions and the solar cycle  

NASA Astrophysics Data System (ADS)

Magnetospheric ions with energies less than tens of eV originate from the ionosphere. Positive low-energy ions are complicated to detect onboard sunlit spacecraft at higher altitudes, which often become positively charged to several tens of volts. We use two Cluster spacecraft and study low-energy ions with a technique based on the detection of the wake behind a charged spacecraft in a supersonic ion flow. We find that low-energy ions usually dominate the density and the outward flux in the geomagnetic tail lobes during all parts of the solar cycle. The global outflow is of the order of 1026 ions/s and often dominates over the outflow at higher energies. The outflow increases by a factor of 2 with increasing solar EUV flux during a solar cycle. This increase is mainly due to the increased density of the outflowing population, while the outflow velocity does not vary much. Thus, the outflow is limited by the available density in the ionospheric source rather than by the energy available in the magnetosphere to increase the velocity.

André, M.; Li, K.; Eriksson, A. I.

2015-02-01

80

Life-cycle energy analyses of electric vehicle storage batteries  

NASA Astrophysics Data System (ADS)

Nickel-zinc, lead-acid, nickel-iron, zinc-chlorine, sodium-sulfur (glass electrolyte), sodium-sulfur (ceramic electrolyte), lithium-metal sulfide, and aluminum-air batteries were studied in order to evaluate the energy used to produce the raw materials and to manufacture the battery, the energy consumed by the battery during its operational life, and the energy that could be saved from the recycling of battery materials into new raw materials. The value of the life cycle analysis approach is that it includes the various penalties and credits associated with battery production and recycling, which enables a more accurate determination of the system's ability to reduce the consumption of scarce fuels. Battery component materials, the energy requirements for battery production, and credits for recycling are described. The operational energy for an electric vehicle and the procedures used to determine it are discussed.

Sullivan, D.; Morse, T.; Patel, P.; Patel, S.; Bondar, J.; Taylor, L.

1980-12-01

81

Dosimetric impact evaluation of primary coolant chemistry of the internal tritium breeding cycle of a fusion reactor DEMO  

SciTech Connect

Tritium will be responsible for a large fraction of the environmental impact of the first generation of DT fusion reactors. Today, the efforts of conceptual development of the tritium cycle for DEMO are mainly centred in the so called Inner Breeding Tritium Cycle, conceived as guarantee of reactor fuel self-sufficiency. The EU Fusion Programme develops for the short term of fusion power technology two breeding blanket conceptual designs both helium cooled. One uses Li-ceramic material (HCPB, Helium-Cooled Pebble Bed) and the other a liquid metal eutectic alloy (Pb15.7Li) (HCLL, Helium-Cooled Lithium Lead). Both are Li-6 enriched materials. At a proper scale designs will be tested as Test Blanket Modules in ITER. The tritium cycles linked to both blanket concepts are similar, with some different characteristics. The tritium is recovered from the He purge gas in the case of HCPB, and directly from the breeding alloy through a carrier gas in HCLL. For a 3 GWth self-sufficient fusion reactor the tritium breeding need is few hundred grams of tritium per day. Safety and environmental impact are today the top priority design criteria. Dose impact limits should determine the key margins and parameters in its conception. Today, transfer from the cycle to the environment is conservatively assumed to be operating in a 1-enclosure scheme through the tritium plant power conversion system (intermediate heat exchangers and helium blowers). Tritium loss is caused by HT and T{sub 2} permeation and simultaneous primary coolant leakage through steam generators. Primary coolant chemistry appears to be the most natural way to control tritium permeation from the breeder into primary coolant and from primary coolant through SG by H{sub 2} tritium flux isotopic swamping or steel (EUROFER/INCOLOY) oxidation. A primary coolant chemistry optimization is proposed. Dynamic flow process diagrams of tritium fluxes are developed ad-hoc and coupled with tritiated effluents dose impact evaluations. Dose assessments are obtained from the use of appropriate numeric tools (NORMTRI). (authors)

Velarde, M. [Instituto de Fusion Nuclear (DENIM), ETSII, Universidad Politecnica Madrid UPM, J. Gutierrez Abascal 2, Madrid 28006 (Spain); Sedano, L. A. [Asociacion Euratom-Ciematpara Fusion, Av. Complutense 22, 28040 Madrid (Spain); Perlado, J. M. [Instituto de Fusion Nuclear (DENIM), ETSII, Universidad Politecnica Madrid UPM, J. Gutierrez Abascal 2, Madrid 28006 (Spain)

2008-07-15

82

ECUT energy data reference series: Otto cycle engines in transportation  

SciTech Connect

Information that describes the use of the Otto cycle engines in transportation is summarized. The transportation modes discussed in this report include the following: automobiles, light trucks, heavy trucks, marine, recreational vehicles, motorcycles, buses, aircraft, and snowmobiles. These modes account for nearly 100% of the gasoline and LPG consumed in transportation engines. The information provided on each of these modes includes descriptions of the average energy conversion efficiency of the engine, the capital stock, the amount of energy used, and the activity level as measured in ton-miles. Estimates are provided for the years 1980 and 2000.

Hane, G.J.; Johnson, D.R.

1984-07-01

83

Consumption dynamics of primary-energy sources: The century of alternative energies  

Microsoft Academic Search

The present article characterizes economically and socially the two past centuries, focusing the consumption development of several primary-energy sources, linking it with this century's reality. The main objective is to demonstrate the relationship between the substitution process of primary-energy sources and the socio-economic development. Our analysis focuses on four technological transformations that have already occurred, emphasizing some aspects of present

João Carlos de Oliveira Matias; Tessaleno Campos Devezas

2009-01-01

84

Consumption dynamics of primary-energy sources: The century of alternative energies  

Microsoft Academic Search

The present article characterizes economically and socially the two past centuries, focusing the consumption development of several primary-energy sources, linking it with this century’s reality. The main objective is to demonstrate the relationship between the substitution process of primary-energy sources and the socio-economic development. Our analysis focuses on four technological transformations that have already occurred, emphasizing some aspects of present

João Carlos de Oliveira Matias; Tessaleno Campos Devezas

2007-01-01

85

Energy life cycle cost analysis: Guidelines for public agencies  

SciTech Connect

The State of Washington encourages energy-efficient building designs for public agencies. The Washington State Energy Office (WSEO) supports this goal by identifying advances in building technology and sharing this information with the design community and public administrators responsible for major construction projects. Many proven technologies can reduce operating costs-and save energy-to an extent that justifies some increases in construction costs. WSEO prepared these Energy Life Cycle Cost Analysis (ELCCA) guidelines for the individuals who are responsible for preparing ELCCA submittals for public buildings. Key terms and abbreviations are provided in Appendix A. Chapters 1 and 2 serve as an overview-providing background, defining energy life cycle cost analysis, explaining which agencies and projects are affected by the ELCCA requirements, and identifying changes to the guidelines that have been made since 1990. They explain {open_quotes}what needs to happen{close_quotes} and {open_quotes}why it needs to happen.{close_quotes} Chapters 3 to 7 provide the {open_quotes}how to,{close_quotes} the instructions and forms needed to prepare ELCCA submittals.

NONE

1995-03-01

86

Energy spectra and composition of primary cosmic rays  

SciTech Connect

New results are described on the energy spectra and relative abundances of primary cosmic ray nuclei from carbon to iron. The measurement was performed on the Spacelab-2 mission of the Space Shuttle Challenger in 1985, and extends to energies beyond 1 TeV per amu. The data indicate that the cosmic ray flux arriving near earth becomes enriched with heavier nuclei, most notably iron, as energy increases. Extrapolating to the source, with a simple leaky box model of galactic propagation with rigidity-dependent containment time, relative abundances of the elements are obtained that are quite similar to those reported at lower energy. In particular, the depletion of elements with high first ionization potential relative to the local galactic abundances, seems to persist in the cosmic ray source well up to TeV energies. A single power-law energy spectrum about E exp {minus}2.1 provides a good description of the observed spectra of most elemental species. 33 refs.

Mueller, D.; Swordy, S.P.; Meyer, P.; L'heureux, J.; Grunsfeld, J.M. (Chicago, University, IL (USA))

1991-06-01

87

Analysis and optimization of a cascading power cycle with liquefied natural gas (LNG) cold energy recovery  

Microsoft Academic Search

The effective utilization of the cryogenic energy associated with LNG vaporization is quite important. In this paper a cascading power cycle with LNG directly expanding consisting of a Rankine cycle with ammonia–water as working fluid and a power cycle of combustion gas is proposed to recover cryogenic energy of LNG. Energy equilibrium equations and exergy equilibrium equations of each equipment

T. Lu

2009-01-01

88

Hydrological consistency using multi-sensor remote sensing data for water and energy cycle studies  

E-print Network

Hydrological consistency using multi-sensor remote sensing data for water and energy cycle studies-sensor/multi-platform approach to water and energy cycle prediction is demonstrated in an effort to understand the variability to an improved understanding of water and energy cycles within the NAME region and providing a novel framework

Pan, Ming

89

Radiative energy receiver for high performance energy conversion cycles  

NASA Technical Reports Server (NTRS)

An analysis of gas dynamic processes pertinent to the functioning of earth-based and space-based solar electric power plants is presented, with attention given to potassium vapor as the working fluid. A device is described which features focused photon absorption by a nontransparent flowing gas. The feed flow is effected around the outside walls of a cavity receiver to raise efficiencies by trapping reemitted energy. A theoretical study of the interaction of a photon flux with a coaxial particle flux was performed, with the receiver flow treated as a Graetz flow. The critical parameters were defined, including a figure of merit as the gas enthalpy increase to absorbable energy ratio. A small-scale laboratory model was tested in comparison with the theoretically obtained values. Less than 15% of the absorbed energy was lost through dissipation while an 80% conversion efficiency was attained.

Rault, D.; Hertzberg, A.

1982-01-01

90

Energy and Water Cycles in a High-Latitude, North-Flowing River System.  

NASA Astrophysics Data System (ADS)

The MacKenzie Global Energy and Water Cycle Experiment (GEWEX) Study, Phase 1, seeks to improve understanding of energy and water cycling in the Mackenzie River basin (MRB) and to initiate and test atmospheric, hydrologic, and coupled models that will project the sensitivity of these cycles to climate change and to human activities. Major findings from the study are outlined in this paper. Absorbed solar radiation is a primary driving force of energy and water, and shows dramatic temporal and spatial variability. Cloud amounts feature large diurnal, seasonal, and interannual fluctuations. Seasonality in moisture inputs and outputs is pronounced. Winter in the northern MRB features deep thermal inversions. Snow hydrological processes are very significant in this high-latitude environment and are being successfully modeled for various landscapes. Runoff processes are distinctive in the major terrain units, which is important to overall water cycling. Lakes and wetlands compose much of MRB and are prominent as hydrologic storage systems that must be incorporated into models. Additionally, they are very efficient and variable evaporating systems that are highly sensitive to climate variability. Mountainous high-latitude subbasins comprise a mosaic of land surfaces with distinct hydrological attributes that act as variable source areas for runoff generation. They also promote leeward cyclonic storm generation. The hard rock terrain of the Canadian Shield exhibits a distinctive energy flux regimen and hydrologic regime. The MRB has been warming dramatically recently, and ice breakup and spring outflow into the Polar Sea has been occurring progressively earlier. This paper presents initial results from coupled atmospheric-hydrologic modeling and delineates distinctive cold region inputs needed for developments in regional and global climate modeling.

Rouse, W. R.; Blyth, E. M.; Crawford, R. W.; Gyakum, J. R.; Janowicz, J. R.; Kochtubajda, B.; Leighton, H. G.; Marsh, P.; Martz, L.; Pietroniro, A.; Ritchie, H.; Schertzer, W. M.; Soulis, E. D.; Stewart, R. E.; Strong, G. S.; Woo, M. K.

2003-01-01

91

Long-term global nuclear energy and fuel cycle strategies  

SciTech Connect

The Global Nuclear Vision Project is examining, using scenario building techniques, a range of long-term nuclear energy futures. The exploration and assessment of optimal nuclear fuel-cycle and material strategies is an essential element of the study. To this end, an established global E{sup 3} (energy/economics/environmental) model has been adopted and modified with a simplified, but comprehensive and multi-regional, nuclear energy module. Consistent nuclear energy scenarios are constructed using this multi-regional E{sup 3} model, wherein future demands for nuclear power are projected in price competition with other energy sources under a wide range of long-term demographic (population, workforce size and productivity), economic (price-, population-, and income-determined demand for energy services, price- and population-modified GNP, resource depletion, world-market fossil energy prices), policy (taxes, tariffs, sanctions), and top-level technological (energy intensity and end-use efficiency improvements) drivers. Using the framework provided by the global E{sup 3} model, the impacts of both external and internal drivers are investigated. The ability to connect external and internal drivers through this modeling framework allows the study of impacts and tradeoffs between fossil- versus nuclear-fuel burning, that includes interactions between cost, environmental, proliferation, resource, and policy issues.

Krakowski, R.A. [Los Alamos National Lab., NM (United States). Technology and Safety Assessment Div.

1997-09-24

92

Understanding the Spatial and Temporal Patterns of Wetland Evapotranspiration, Primary Production, and Nutrient Cycling  

E-print Network

Understanding the Spatial and Temporal Patterns of Wetland Evapotranspiration, Primary Production the biogeochemical budgets and evapotranspiration in California wetlands are poorly understood. We propose research the CO2 exchange (FCO2) and evapotranspiration (E) between the atmosphere and the San Joaquin Marsh. Eddy

Goulden, Michael L.

93

A Didactic Model of the Seasonal Cycle in Energy Fluxes and Climate  

NASA Astrophysics Data System (ADS)

In the annual mean, the polar regions receive a deficit of solar insolation relative to the global average. The local energy budget is balanced primarily by atmospheric heat transport into the region, with smaller contributions from ocean heat transport and anomalously low outgoing longwave radiation (relative to the global average). In contrast, the annual cycle features large seasonal anomalies (departures from the local annual average) in solar insolation in the polar regions that are primarily balanced by ocean heat storage anomalies; changes in meridional heat transport, emitted long wave radiation, and atmospheric heat storage play a decreasingly important role in the seasonal energy balance. Land-ocean contrasts also have a large impact on the seasonal energetics of the polar climate system. Over the ocean, zonal heat transport from the land domain is maximized during the summer, and the sum of the insolation and zonal heat transport anomalies is balanced by ocean heat storage. In contrast, over the land, the primary summertime balance is excess solar insolation balanced by an enhanced zonal heat export. In this study we examine the global scale climate and the aforementioned seasonal cycle of energy fluxes using an aquaplanet atmospheric general circulation model coupled to a slab ocean and a simplified energy balance model that interacts with the underlying ocean. The gross climate and seasonal energetics in both models are highly sensitive to the specification of ocean mixed layer depth. The observed seasonal cycle of energy fluxes and the land and ocean temperatures are also replicated in a simplified energy balance model that includes land-ocean contrast and the hemispheric differences in fractional land area. The sensitivity of the seasonal cycle in climate (atmosphere and ocean temperatures) - and in the gross partitioning of the mix of energy flux processes that determine the climate - to the fractional land area is further explored in an ensemble of energy balance model integrations. In both the aquaplanet and land-ocean contrast energy balance models, the partitioning of energy fluxes amongst different physical processes can be understood in terms of the sensitivity of those processes to temperature perturbations. These experiments collectively demonstrate the effect of ocean mixed layer depth and fractional land area on climate and the seasonal partitioning of the various energy flux processes.

Donohoe, A.; Battisti, D.

2009-12-01

94

Wogonin induces cell cycle arrest and erythroid differentiation in imatinib-resistant K562 cells and primary CML cells  

PubMed Central

Wogonin, a flavonoid derived from Scutellaria baicalensis Georgi, has been demonstrated to be highly effective in treating hematologic malignancies. In this study, we investigated the anticancer effects of wogonin on K562 cells, K562 imatinib-resistant cells, and primary patient-derived CML cells. Wogonin up-regulated transcription factor GATA-1 and enhanced binding between GATA-1 and FOG-1, thereby increasing expression of erythroid-differentiation genes. Wogonin also up-regulated the expression of p21 and induced cell cycle arrest. Studies employing benzidine staining and analyses of cell surface markers glycophorin A (GPA) and CD71 indicated that wogonin promoted differentiation of K562, imatinib-resistant K562, and primary patient-derived CML cells. Wogonin also enhanced binding between GATA-1 and MEK, resulting in inhibition of the growth of CML cells. Additionally, in vivo studies showed that wogonin decreased the number of CML cells and prolonged survival of NOD/SCID mice injected with K562 and imatinib-resistant K562 cells. These data suggested that wogonin induces cycle arrest and erythroid differentiation in vitro and inhibits proliferation in vivo. PMID:25149543

Wang, Qian; Li, Hui; Zhao, Kai; Zhou, Yuxin; Zhu, Yu; Wang, Xiaotang; You, Qidong; Guo, Qinglong; Lu, Na

2014-01-01

95

Recovered Energy Generation Using an Organic Rankine Cycle System  

SciTech Connect

This paper describes the results of a project demonstrating the technical and economic feasibility of capturing thermal energy from a 35,000 hp (27 MW) gas turbine driving a natural gas pipeline compressor with a Recovered Energy Generation (REG) system to produce 5.5 MW of electricity with no additional fuel and near-zero emissions. The REG is based on a modified Organic Rankine Cycle (ORC). Other major system elements include a waste-heat-to-oil heat exchanger with bypass, oil-to-pentane heat exchanger with preheater, recuperator, condenser, pentane turbine, generator and synchronizing breaker and all power and control systems required for the automatic operation of the REG. When operating at design heat input available from the gas turbine exhaust, the REG system consistently delivered 5.5 MW or more output to the grid at up to 15 percent heat conversion efficiency. The REG system improved the overall energy efficiency by 28%, from 32% simple cycle efficiency to 41% for the combined system. Significant lessons learned from this project are discussed as well as measured performance and economic considerations.

Leslie, Neil [Gas Technology Institute] [Gas Technology Institute; Sweetser, Richard [Exergy Partners Corp.] [Exergy Partners Corp.; Zimron, Ohad [Ormat] [Ormat; Stovall, Therese K [ORNL] [ORNL

2009-01-01

96

The NASA Energy and Water Cycle Extreme (NEWSE) Integration Project  

NASA Technical Reports Server (NTRS)

Skillful predictions of water and energy cycle extremes (flood and drought) are elusive. To better understand the mechanisms responsible for water and energy extremes, and to make decisive progress in predicting these extremes, the collaborative NASA Energy and Water cycle Extremes (NEWSE) Integration Project, is studying these extremes in the U.S. Southern Great Plains (SGP) during 2006-2007, including their relationships with continental and global scale processes, and assessment of their predictability on multiple space and time scales. It is our hypothesis that an integrative analysis of observed extremes which reflects the current understanding of the role of SST and soil moisture variability influences on atmospheric heating and forcing of planetary waves, incorporating recently available global and regional hydro- meteorological datasets (i.e., precipitation, water vapor, clouds, etc.) in conjunction with advances in data assimilation, can lead to new insights into the factors that lead to persistent drought and flooding. We will show initial results of this project, whose goals are to provide an improved definition, attribution and prediction on sub-seasonal to interannual time scales, improved understanding of the mechanisms of decadal drought and its predictability, including the impacts of SST variability and deep soil moisture variability, and improved monitoring/attributions, with transition to applications; a bridging of the gap between hydrological forecasts and stakeholders (utilization of probabilistic forecasts, education, forecast interpretation for different sectors, assessment of uncertainties for different sectors, etc.).

House, P. R.; Lapenta, W.; Schiffer, R.

2008-01-01

97

Fuel cycle analysis for fossil energy systems: Coal combustion  

NASA Astrophysics Data System (ADS)

Elements of the fuel cycle for coal combustion in power generation are examined; and information on economics, technological status, energy efficiencies, and environmental issues is reviewed. Overall background information is provided for guidance in identifying issues and establishing needs and priorities for engineering research, development, and demonstration. The elements treated include mining, transportation, coal preparation, direct combustion, and environmental control technology. The treatment used differs from that of usual compendiums in its emphasis on integrated examination and presentation directed primarily toward providing bases for general assessment and for guidance in program development. Emphasis is on program identification as opposed to advocacy.

Greenstreet, W. L.; Carmichael, R. L.

1981-02-01

98

Life Cycle Assessment Projection of Photovoltaic Cells: A Case Study on Energy Demand of Quantum Wire Based Photovoltaic Technology Research  

NASA Astrophysics Data System (ADS)

With increasing clean-energy demand, photovoltaic (PV) technologies have gained attention as potential long-term alternative to fossil fuel energy. However, PV research and manufacture still utilize fossil fuel-powered grid electricity. With continuous enhancement of solar conversion efficiency, it is imperative to assess whether overall life cycle efficiency is also being enhanced. Many new-material PV technologies are still in their research phase, and life cycle analyses of these technologies have not yet been performed. For best results, grid dependency must be minimized for PV research, and this can be accomplished by an analytical instrument called Life Cycle Assessment (LCA). LCA is the study of environmental impacts of a product throughout its life cycle. While there are some non-recoverable costs of research, energy is precious, and the PV research community should be aware of its energy consumption. LCA can help identify options for energy conservation through process optimization. A case study was conducted on the energy demand of a test-bed emerging PV technology using life cycle assessment methodology. The test-bed system chosen for this study was a new-material PV cell. The objective was to quantify the total energy demand for the research phase of the test-bed solar cell's life cycle. The objective was accomplished by collecting primary data on energy consumption for each process in the development of this solar cell. It was found that 937 kWh of energy was consumed for performing research on a single sample of the solar cell. For comparison, this energy consumption is 83% of Arkansas's average monthly residential electricity consumption. Life cycle inventory analysis showed that heating, ventilation, and air conditioning consumed the bulk of the energy of research. It is to be noted that the processes studied as part of the solar cell test-bed system are representative of a research process only. Life cycle thinking can identify energy hot-spots and help a new lab be set up in a more energy-efficient way. Proactive action based on the results can lead to higher energy return on investment, making emerging PV technologies truly energy-competitive.

Mukherjee, Shilpi

99

The Urban Water Cycle and how it Modulates the Microclimate and the Energy Cycle  

NASA Astrophysics Data System (ADS)

Urbanization is the land-use modification with the largest and most manifest impacts on hydrologic storage and fluxes. This perturbation of the water cycle also has considerable ramifications on the surface energy budget and the microclimatology in built terrain: reducing the potential for water storage and subsequent evaporation reduces the fraction of incoming radiative energy dissipated through surface evaporation, and consequently increases the sensible heating of the urban atmosphere and solid surfaces (buildings, roads, …). However, the complexity of the involved physical processes and their interactions have so far been oversimplified, leading to considerable biases in model output when compared to observations. Using novel sensing techniques that include wireless sensor networks, this study seeks to build a better understanding of the Urban Water Cycle. Our findings indicate that "impervious surfaces" in urban area are not really impervious and not always dry. The role of evaporation from gravel-covered roofs and from concrete, brick, stone and asphalt surfaces can be considerable, leading to lower sensible heating. In addition, the different thermal properties of the various urban materials lead to extreme spatial heterogeneity in surface conditions that is much higher than over natural terrain. Building on this understanding, an improved urban canopy model is developed that includes much better representation of surface heterogeneity and of hydrological and thermal storage and transport processes, including analytical solutions of the heat equation and numerical solutions of the Richards equation in the urban surface. The model development will be detailed and applications focusing on the role of evaporation in mitigating summer building cooling needs and urban heat island effects will be presented.

Bou-Zeid, E.; Wang, Z.; Ramamurthy, P.; Li, D.; Sun, T.; Smith, J. A.

2012-12-01

100

Toward Describing the Effects of Ozone Depletion on Marine Primary Productivity and Carbon Cycling  

NASA Technical Reports Server (NTRS)

This project was aimed at improved predictions of the effects of UVB and ozone depletion on marine primary productivity and carbon flux. A principal objective was to incorporate a new analytical description of photosynthesis as a function of UV and photosynthetically available radiation (Cullen et. al., Science 258:646) into a general oceanographic model. We made significant progress: new insights into the kinetics of photoinhibition were used in the analysis of experiments on Antarctic phytoplankton to generate a general model of UV-induced photoinhibition under the influence of ozone depletion and vertical mixing. The way has been paved for general models on a global scale.

Cullen, John J.

1995-01-01

101

Decision-making of nuclear energy policy: application of environmental management tool to nuclear fuel cycle  

Microsoft Academic Search

This study aims to evaluate and estimate the environmental impacts of nuclear fuel cycles and to support the decision-making of nuclear energy policy, relating to a selection of environmentally preferred nuclear fuel cycle for the environmentally sound and sustainable development of nuclear energy. To achieve this objective, life cycle assessment (LCA) as an environmental management tool is applied to the

Young Eal Lee; Kyoo-Kun Koh

2002-01-01

102

Outflow of Low-Energy Ions and the Solar Cycle  

NASA Astrophysics Data System (ADS)

Non-thermal escape of ions from the upper Terrestrial atmosphere has been observed by spacecraft and radars for decades. Typical total upflow rates are 1025 to 1026 ions/s, mainly H+ and O+varying with solar and magnetospheric magnetic activity. Recent findings show that the escape, and the plasma in the magnetosphere, often is dominated by low-energy (below about 10 eV) ions. These ions often cannot be detected onboard sunlit spacecraft, which often become positively charged to tens of volts. We discuss how a supersonic flow of low-energy ions cause a wake behind a charged spacecraft and how this can be used to detect the ions. We use the wake method and observations by two Cluster spacecraft, covering most of a solar cycle (2001 to 2010). We find that often (more than 50% of the time) low-energy ions dominate the magnetosphere. We also find a clear variation of the outflow of low-energy ions with the solar EUV flux.

Andre, Mats; Li, Kun; Eriksson, Anders

2014-05-01

103

Biomass Stove Pollution Sam Beck ATOC-3500 Biomass energy accounts for about 15% of the world's primary energy consumption and  

E-print Network

Biomass Stove Pollution Sam Beck ATOC-3500 Biomass energy accounts for about 15% of the world. Furthermore, biomass often accounts for more than 90% of the total rural energy supplies in developing's primary energy consumption and about 38% of the primary energy consumption in developing countries

Toohey, Darin W.

104

Implications of incorporating N cycling and N limitations on primary production in an individual-based dynamic vegetation model  

NASA Astrophysics Data System (ADS)

The LPJ-GUESS dynamic vegetation model uniquely combines an individual- and patch-based representation of vegetation dynamics with ecosystem biogeochemical cycling from regional to global scales. We present an updated version that includes plant and soil N dynamics, analysing the implications of accounting for C-N interactions on predictions and performance of the model. Stand structural dynamics and allometric scaling of tree growth suggested by global databases of forest stand structure and development were well reproduced by the model in comparison to an earlier multi-model study. Accounting for N cycle dynamics improved the goodness of fit for broadleaved forests. N limitation associated with low N-mineralisation rates reduces productivity of cold-climate and dry-climate ecosystems relative to mesic temperate and tropical ecosystems. In a model experiment emulating free-air CO2 enrichment (FACE) treatment for forests globally, N limitation associated with low N-mineralisation rates of colder soils reduces CO2 enhancement of net primary production (NPP) for boreal forests, while some temperate and tropical forests exhibit increased NPP enhancement. Under a business-as-usual future climate and emissions scenario, ecosystem C storage globally was projected to increase by ca. 10%; additional N requirements to match this increasing ecosystem C were within the high N supply limit estimated on stoichiometric grounds in an earlier study. Our results highlight the importance of accounting for C-N interactions in studies of global terrestrial N cycling, and as a basis for understanding mechanisms on local scales and in different regional contexts.

Smith, B.; Wårlind, D.; Arneth, A.; Hickler, T.; Leadley, P.; Siltberg, J.; Zaehle, S.

2014-04-01

105

Energy harvesting measurements from stall flutter limit cycle oscillations  

NASA Astrophysics Data System (ADS)

Results from experiments using a two-degree-of-freedom airfoil system are presented. Air speeds of the airfoil are determined at which dynamic flutter can be initiated and where limit cycle oscillations (LCO) can be excited by initial (pitch or plunge) displacements. LCO's with large pitch angle displacements attributed to stall flutter behavior are measured. The LCO oscillations are converted into electric power by an electromagnetic-inductor device. The energy harvester consists of three magnets in which one magnet floats between two fixed magnets. The force-displacement relationship of the harvester is best described by a fifth-order polynomial. The integration of the harvester into the airfoil system introduces nonlinear stiffness into the vertical (plunge) direction. When the LCO has been initiated, displacement amplitudes and resulting power generation are measured.

Chen, Jasper; Dhanushkodi, Adit; Lee, Christopher L.

2014-04-01

106

Appraisal of the remineralizing potential of child formula dentifrices on primary teeth: An in vitro pH cycling model  

PubMed Central

Aim: To evaluate the remineralizing potential of child formula dentifrices on primary teeth using an in vitro 7 days pH cycling model. Materials and Methods: Twenty-one primary teeth were placed in demineralizing solution for 96 h to produce artificial carious lesions; then cut longitudinally into 100–150 ?m thick sections and randomly assigned to three groups. Sections in Group A were treated with dentifrice containing 458 ppm monofluorophosphate (MFP) and sections in Group B with 500 ppm sodium fluoride (NaF). Group C sections were treated with a nonfluoridated dentifrice. Results: Group A (458 ppm MFP) and Group B (500 ppm NaF) showed significant decrease in lesion depth, whereas Group C (non F) showed a significant increase in depth (P ? 0.05, paired t-test). Conclusion: Though dentifrices containing 458 ppm MFP and 500 ppm NaF demonstrated remineralization of carious lesions, it was not complete. Therefore, it is also important to emphasize on other preventive methods in the prevention and/or reversal of carious lesions.

Kiranmayi, M.; Nirmala, S. V. S. G.; Nuvvula, Sivakumar

2015-01-01

107

Molecular mechanism of transforming growth factor ?–mediated cell-cycle modulation in primary human CD34+ progenitors  

PubMed Central

The mechanisms by which transforming growth factor ? (TGF-?) exerts a negative effect on cell-cycle entry in primary human hematopoietic stem/progenitor cells were examined at the molecular and cellular levels. After treatment of primary human CD34+ progenitors with TGF-? there was a decrease in the levels of cyclin D2 protein and an increase in levels of the cyclin-dependent kinase inhibitor (CDKI) p15 as compared to the levels in untreated cells. The converse was true after addition of neutralizing anti–TGF-? antibody. Administration of TGF-? to CD34+ cells in the presence of cytokines prevented retinoblastoma protein (pRb) phosphorylation, which occurred in the same cells treated with cytokines alone or cytokines and anti–TGF-? antibody. Neutralization of TGF-? during 24 to 48 hours of culture with cytokines significantly increased the number of colony-forming progenitors, but did not modulate the human stem cell pool, as measured in 6- to 12-month xenotransplantation assays. Equivalent numbers of human B, T, and myeloid cells were obtained after transplantation of cells treated with or without neutralization of TGF-?. PMID:11781230

Dao, Mo A.; Hwa, Joseph; Nolta, Jan A.

2015-01-01

108

Critical role for the kinesin KIF3A in the HIV life cycle in primary human macrophages.  

PubMed

Macrophages are long-lived target cells for HIV infection and are considered viral reservoirs. HIV assembly in macrophages occurs in virus-containing compartments (VCCs) in which virions accumulate and are stored. The regulation of the trafficking and release of these VCCs remains unknown. Using high resolution light and electron microscopy of HIV-1-infected primary human macrophages, we show that the spatial distribution of VCCs depended on the microtubule network and that VCC-limiting membrane was closely associated with KIF3A+ microtubules. Silencing KIF3A strongly decreased virus release from HIV-1-infected macrophages, leading to VCC accumulation intracellularly. Time-lapse microscopy further suggested that VCCs and associated KIF3A move together along microtubules. Importantly, KIF3A does not play a role in HIV release from T cells that do not possess VCCs. These results reveal that HIV-1 requires the molecular motor KIF3 to complete its cycle in primary macrophages. Targeting this step may lead to novel strategies to eliminate this viral reservoir. PMID:23091068

Gaudin, Raphaël; de Alencar, Bruna Cunha; Jouve, Mabel; Bèrre, Stefano; Le Bouder, Emmanuel; Schindler, Michael; Varthaman, Aditi; Gobert, François-Xavier; Benaroch, Philippe

2012-10-29

109

Single Cycle of Arsenic Trioxide–Based Consolidation Chemotherapy Spares Anthracycline Exposure in the Primary Management of Acute Promyelocytic Leukemia  

PubMed Central

Purpose Event-free survival following all-trans-retinoic acid (ATRA) –based therapy for acute promyelocytic leukemia (APL) averages 70% at 5 years. While arsenic trioxide (ATO) can induce remissions in 95% of relapsed patients, few studies have addressed the integration of ATO into the primary management of APL. This study examines the efficacy of a single cycle of ATO-based consolidation therapy in a treatment regimen designed to decrease exposure to other cytotoxic agents. Patients and Methods After induction with ATRA and daunorubicin (DRN), untreated patients with APL received 3 days of cytarabine and DRN followed by 30 doses of ATO beginning on day 8. Molecular remitters received 2 years of risk-based maintenance therapy. Results Forty-one of 45 patients receiving induction therapy achieved remission; four patients died (one before treatment was initiated). Thirty-seven patients received consolidation and maintenance; of these one patient relapsed (CNS) and one died in remission during maintenance therapy (hepatic sickle cell crisis). With a median follow-up of 2.7 years, estimated disease-free survival was 90%; overall survival for all patients was 88%. Despite a total anthracycline dose of only 360 mg/m2, cardiac ejection fraction decreased by ? 20% in 20% of patients. Conclusion These data, combined with other recent studies using ATO in the primary management of APL, demonstrate the important role that ATO can play in the primary management of this curable disease. Future studies should continue to focus on reducing the toxicity of treatment without increasing the relapse rate. PMID:20085935

Gore, Steven D.; Gojo, Ivana; Sekeres, Mikkael A.; Morris, Lawrence; Devetten, Marcel; Jamieson, Katarzyna; Redner, Robert L.; Arceci, Robert; Owoeye, Ibitayo; Dauses, Tianna; Schachter-Tokarz, Esther; Gallagher, Robert E.

2010-01-01

110

Primary Energy Production via Light Reactions With Humic Substances.  

NASA Astrophysics Data System (ADS)

Humic substances (HS) represent a ubiquitous and structurally diverse form of complex organic matter in the environment. Often considered recalcitrant to microbial degradation, HS nevertheless support both oxidative and reductive energy-generating microbial respiratory reactions. For example, microorganisms can oxidize reduced functional groups within HS (such as hydroquinones) providing electrons capable of supporting anaerobic respiratory processes. In this study we investigated the ability of HS to mediate the capture of light energy and its subsequent conversion into bioavailable chemical energy that can be used to support microbial growth. Aged acid iron mine drainage systems were used as a model environment for this metabolic scheme. Acidic solutions containing 5mM concentrations of the model humic quinone 2,6-anthraquinone disulfonate (AQDS) and ferric chloride were illuminated with both UV and visible light. Illumination led to the production of Fe(II) beyond that observed in either dark controls or in illuminated controls lacking AQDS. Likewise, HS isolated from marine, swamp, and lake sources were capable of enhancing Fe(II) production under the same illumination conditions. Fe(II) generated in these co-illuminated photoreactions was readily oxidized by the aerobic Fe(II)-oxidizing archeon, Ferroplasma acidarmanus Fer1T, indicating the bioavailability of photogenerated Fe(II). No oxidation of Fe(II) was observed in the absence of cells. Cell counts indicated that the oxidation of approximately 2.0mM photo-produced Fe(II) by Fer1T was coupled with cell growth. Oxic and anoxic illumination of 5mM AQDS solutions alone with UV or visible light led to the production of reduced organic species, whose reducing equivalents could be scavenged as Fe(II) in a subsequent dark reaction by the addition of Fe(III). Likewise, HS from a variety of environments could be converted to more reduced species via UV illumination under anoxic conditions or even by exposure to the radioactive decay products of a Cs-137 source (gamma rays and beta particles). Fe(II) produced from dark reactions with the photoreduced HS or AQDS products was also bioavailable, and could be rapidly oxidized under aerobic conditions by Fer1T. Again, no Fe(II) oxidation occurred in the absence of cells. Alternatively, the photoreduced AQDS could be directly oxidized as an electron donor in the absence of the iron shuttle by model denitrifying microorganisms under anoxic conditions. These data suggest that light interactions with HS support primary production by converting light energy into bioavailable reducing equivalents such as reduced humic material and Fe(II) that can be used to support microbial chemotrophic growth.

van Trump, J. I.; Coates, J. D.

2008-12-01

111

The role of organic ligands in iron cycling and primary productivity in the Antarctic Peninsula: A modeling study  

NASA Astrophysics Data System (ADS)

Iron (Fe) is the limiting nutrient for primary productivity in the Southern Ocean, with much of the dissolved iron (dFe) bound to organic ligands or colloids. A Fe model for the Southern Ocean (SOFe) is developed to understand the role of bacteria and organic ligands in controlling Fe cycling and productivity. The model resolves the classical food web and microbial loop, including three types of nutrients (N, Si, Fe) and two types of Fe ligands. Simulations of the zero-dimensional (0-D) model are calibrated with detailed results of shipboard grow-out incubation experiments conducted with Antarctic Peninsula phytoplankton communities during winter 2006 to provide the best estimate of key biological parameters. Then a one-dimensional (1-D) model is developed by coupling the biological model with the Regional Oceanic Modeling System (ROMS) for a site on the Antarctic Peninsula shelf, and the model parameters are further calibrated with data collected from two surveys (summer 2004 and winter 2006) in the area. The results of the numerical simulations agree reasonably well with observations. An analysis of the 1-D model results suggests that bacteria and organic ligands may play an important role in Fe cycling, which can be categorized into a relatively fast mode within the euphotic zone dominated by photo-reactions (summer d Fe residence time about 600 days) and complexation and a slow mode below with most of the dFe biologically complexed (summer dFe residence time >10 years). The dFe removal from the euphotic zone is dominated by colloidal formation and further aggregations with additional contribution from biological uptake, and an increase of organic ligands would reduce Fe export. The decrease of Fe removal rate over depth is due to the continuous dissolution and remineralization of particulate Fe. A number of sensitivity experiments are carried out for both 0-D and 1-D models to understand the importance of photo-reactive processes in primary productivity, bacterial activity, Fe speciation, and dFe residence time within the euphotic zone. The bio-availability of ligand-bound Fe (FeL) is critical to modeled high primary productivity, which is consistent with both shipboard measurements and field observations. In addition, model productivity is sensitive to photoreaction rates if FeL is not directly available for phytoplankton uptake.

Jiang, Mingshun; Barbeau, Katherine A.; Selph, Karen E.; Measures, Christopher I.; Buck, Kristen N.; Azam, Farooq; Greg Mitchell, B.; Zhou, Meng

2013-06-01

112

Evaluation of high-energy lithium thionyl chloride primary cells  

NASA Technical Reports Server (NTRS)

An advanced commercial primary lithium cell (LiSoCl2) was evaluated in order to establish baseline data for improved lithium batteries for aerospace applications. The cell tested had nominal capacity of 6 Ah. Maximum energy density at low rates (less than C/30, where C is the cell capacity in amp-hrs and 30 corresponds to a 30 hr discharge time) was found to be near 300 Wh/kg. An equation which predicts the operating voltage of these cells as a function of current and state of charge is presented. Heat generation rates of these cells were determined as a function of current in a calorimeter. It was found that heat rates could be theoretically predicted with some degree of accuracy at currents less than 1 amp or the C/6 rate. No explosions were observed in the cells during the condition of overdischarge or reversal nor during high rate discharge. It was found, however, that the cells can vent when overdischarge currents are greater than C/30 and when discharge rates are greater than 1.5C.

Frank, H. A.

1980-01-01

113

The Path to Sustainable Nuclear Energy. Basic and Applied Research Opportunities for Advanced Fuel Cycles  

Microsoft Academic Search

The objective of this report is to identify new basic science that will be the foundation for advances in nuclear fuel-cycle technology in the near term, and for changing the nature of fuel cycles and of the nuclear energy industry in the long term. The goals are to enhance the development of nuclear energy, to maximize energy production in nuclear

P. Finck; N. Edelstein; T. Allen; C. Burns; M. Chadwick; M. Corradini; D. Dixon; M. Goff; J. Laidler; K. McCarthy; B. Moyer; K. Nash; A. Navrotsky; P. Oblozinsky; K. Pasamehmetoglu; P. Peterson; J. Sackett; K. E. Sickafus; J. Tulenko; W. Weber; L. Morss; G. Henry

2005-01-01

114

Life cycle assessment of a solar thermal collector: sensitivity analysis, energy and environmental balances  

Microsoft Academic Search

Starting from the results of a life cycle assessment of solar thermal collector for sanitary warm water, an energy balance between the employed energy during the collector life cycle and the energy saved thanks to the collector use has been investigated. A sensitivity analysis for estimating the effects of the chosen methods and data on the outcome of the study

Fulvio Ardente; Giorgio Beccali; Maurizio Cellura; Valerio Lo Brano

2005-01-01

115

Open cycle ocean thermal energy conversion system structure  

DOEpatents

A generally mushroom-shaped, open cycle OTEC system and distilled water producer which has a skirt-conduit structure extending from the enlarged portion of the mushroom to the ocean. The enlarged part of the mushroom houses a toroidal casing flash evaporator which produces steam which expands through a vertical rotor turbine, partially situated in the center of the blossom portion and partially situated in the mushroom's stem portion. Upon expansion through the turbine, the motive steam enters a shell and tube condenser annularly disposed about the rotor axis and axially situated beneath the turbine in the stem portion. Relatively warm ocean water is circulated up through the radially outer skirt-conduit structure entering the evaporator through a radially outer portion thereof, flashing a portion thereof into motive steam, and draining the unflashed portion from the evaporator through a radially inner skirt-conduit structure. Relatively cold cooling water enters the annular condenser through the radially inner edge and travels radially outwardly into a channel situated along the radially outer edge of the condenser. The channel is also included in the radially inner skirt-conduit structure. The cooling water is segregated from the potable, motive steam condensate which can be used for human consumption or other processes requiring high purity water. The expansion energy of the motive steam is partially converted into rotational mechanical energy of the turbine rotor when the steam is expanded through the shaft attached blades. Such mechanical energy drives a generator also included in the enlarged mushroom portion for producing electrical energy. Such power generation equipment arrangement provides a compact power system from which additional benefits may be obtained by fabricating the enclosing equipment, housings and component casings from low density materials, such as prestressed concrete, to permit those casings and housings to also function as a floating support vessel.

Wittig, J. Michael (West Goshen, PA)

1980-01-01

116

Titan's Methane Cycle and the Surface Energy Budget  

NASA Astrophysics Data System (ADS)

The atmosphere of Titan holds and transports a large reservoir of methane. Previous general circulation models (GCMs) show a divergence of methane from the equatorial regions resulting from seasonal changes in the circulation of the atmosphere. However, previous GCMs used to study the methane cycle have employed simplified radiative transfer that does not accurately capture the distribution of surface insolation. Titan's seasonal convective clouds, which occur despite the atmosphere's huge thermal inertia, result from exchanges of heat and moisture with the surface; thus, the surface energy balance is important for the methane transport. The surface energy budget in equilibrium is a balance between net surface radiation and turbulent surface fluxes of latent and sensible energy. Our GCM simulations, including nongray radiation transfer that uses optical properties derived from Cassini/Huygens data, show that maximum surface insolation, and therefore destabilizing surface energy fluxes, oscillate seasonally between midlatitudes. The GCM produces rain at latitudes and seasons where clouds have been observed, and at the same time produces a buildup of polar surface liquids. Furthermore, we find no buildup of midlatitude surface methane, in contrast to previous work. The upwelling branch of the mean meridional circulation tracks with the maximum sensible heat flux from the surface, and when evaporation is significant at low latitudes, this translates into an abrupt transition of the upwelling across the equator during equinoxes. On the other hand, the latitudinal migration of precipitation is less abrupt than in the case where evaporation is negligible near the equator (in which case precipitation can also be more temporally sporadic). Additionally, the latitudinal extent of the upwelling branch of the mean meridional circulation and the asymmetry in the latitudinal distribution of surface liquids appear to be diagnostic of the amount of methane available to the atmosphere from the surface reservoir.

Lora, J. M.; Russell, J. L.; Lunine, J. I.

2013-12-01

117

Present and future status of thermochemical cycles applied to fusion energy sources  

SciTech Connect

This paper reviews the status of current research on thermochemical hydrogen production cycles and identifies the needs for advanced cycles and materials research. The Los Alamos Scientific Laboratory (LASL) bismuth sulfate thermochemical cycle is characterized, and fusion reactor blanket concepts for both inertial and magnetic confinement schemes are presented as thermal energy sources for process heat applications.

Booth, L.A.; Cox, K.E.; Krakowski, R.A.; Pendergrass, J.H.

1980-01-01

118

Global Energy and Water Cycle Experiment mate models appear to systematically under-predict  

E-print Network

5May 2009 Global Energy and Water Cycle Experiment mate models appear to systematically under characteristics of the water cycle variables that control the design and reliability of water resource systems design; and understanding the apparent under-persistence in water cycle variable time series generated

Colorado at Boulder, University of

119

Proceedings of GLOBAL 2013: International Nuclear Fuel Cycle Conference - Nuclear Energy at a Crossroads  

SciTech Connect

The Global conference is a forum for the discussion of the scientific, technical, social and regulatory aspects of the nuclear fuel cycle. Relevant topics include global utilization of nuclear energy, current fuel cycle technologies, advanced reactors, advanced fuel cycles, nuclear nonproliferation and public acceptance.

NONE

2013-07-01

120

Transporting carbon dioxide recovered from fossil-energy cycles  

SciTech Connect

Transportation of carbon dioxide (CO{sub 2}) for enhanced oil recovery is a mature technology, with operating experience dating from the mid-1980s. Because of this maturity, recent sequestration studies for the US Department of Energy's National Energy Technology Laboratory have been able to incorporate transportation into overall energy-cycle economics with reasonable certainty. For these studies, two different coal-fueled plants are considered; the first collects CO{sub 2} from a 456-MW integrated coal gasification combined-cycle plant, while the second employs a 353-MW pulverized-coal boiler plant retrofitted for flue-gas recycling (Doctor et al. 1999; MacDonald and Palkes 1999). The pulverized-coal plant fires a mixture of coal in a 33% O{sub 2} atmosphere, the bulk of the inert gas being made up to CO{sub 2} to the greatest extent practical. If one power plant with one pipe feeds one sequestration reservoir, projected costs for a 500-km delivery pipeline are problematic, because when supplying one reservoir both plant availability issues and useful pipeline life heavily influence capital recovery costs. The transportation system proposed here refines the sequestration scheme into a network of three distinctive pipelines: (1) 80-km collection pipelines for a 330-MW pulverized-coal power plant with 100% CO{sub 2} recovery; (2) a main CO{sub 2} transportation trunk of 320 km that aggregates the CO{sub 2} from four such plants; and (3) an 80-km distribution network. A 25-year life is assumed for the first two segments, but only half that for the distribution to the reservoir. Projected costs for a 500-km delivery pipeline, assuming an infrastructure, are $7.82/tonne ($17.22/10{sup 3} Nm{sub 3} CO{sub 2} or $0.49/10{sup 3} scf CO{sub 2}), a savings of nearly 60% with respect to base-case estimates with no infrastructure. These costs are consistent only with conditioned CO{sub 2} having low oxygen and sulfur content; they do not include CO{sub 2} recovery, drying, and compression.

Doctor, R. D.; Molburg, J. C.; Brockmeier, J. F.

2000-07-24

121

The NASA Energy and Water cycle Extreme (NEWSE) Integration Project  

NASA Astrophysics Data System (ADS)

Skillful predictions of water and energy cycle extremes (flood and drought) are elusive. To better understand the mechanisms responsible for water and energy extremes, and to make decisive progress in predicting these extremes, the collaborative NASA Energy and Water cycle Extremes (NEWSE) Integration Project, is studying these extremes in the U.S. Southern Great Plains (SGP) during 2006-2007, including their relationships with continental and global scale processes, and assessment of their predictability on multiple space and time scales. It is our hypothesis that an integrative analysis of observed extremes which reflects the current understanding of the role of SST and soil moisture variability influences on atmospheric heating and forcing of planetary waves, incorporating recently available global and regional hydro- meteorological datasets (i.e., precipitation, water vapor, clouds, etc.) in conjunction with advances in data assimilation, can lead to new insights into the factors that lead to persistent drought and flooding. We will show initial results of this project, whose goals are toprovide an improved definition, attribution and prediction on sub-seasonal to interannual time scales, improved understanding of the mechanisms of decadal drought and its predictability, including the impacts of SST variability and deep soil moisture variability, and improved monitoring/attributions, with transition to applications; a bridging of the gap between hydrological forecasts and stakeholders (utilization of probabilistic forecasts, education, forecast interpretation for different sectors, assessment of uncertainties for different sectors, etc.). *The NEWSE Team is: Romanou, Anastasiam, Columbia U.; Brian Soden, U. Miami; William Lapenta, NASA- MSFC; Megan Larko, CREW; Bing Lin, NASA-LaRC; Christa Peters-Lidard, NASA-GSFC; Xiquan Dong, U. North Dakota; Debbie Belvedere, CREW; Mathew Sapiano, U. Maryland; Duane Waliser, NASA-JPL; Eni Njoku, NASA/JPL; Eric Fetzer, NASA-JPL; Eyal Amitai, NASA-GSFC; Xiaogang Gao, U. California, Irvine; George Huffman, NASA-GSFC & SSAI; Jared Entin, NASA; Joseph Santanello, NASA-GSFC; John Roads, UCSD; W. Timothy Liu, NASA-JPL; Lixin Lu, Colorado State U.; Zhengzhao Luo, Colorado State U.; Michael Bosilovich, NASA-GSFC; Michael Jasinski, NASA-GSFC; William Olson, NASA-GSFC & UMBC-GEST; Pete Robertson, NASA-MSFC; Phil Arkin, U. Maryland; Paul Houser, CREW & GMU; Ralph Ferraro, NOAA; Pete Robertson, NASA-MSFC; Robert Schiffer; UMBC-GEST; Sujay Kumar, NASA-GSFC; Joseph A. Santanello, NASA-GSFC; Tristan L'Ecuyer, Colorado State U.; Wei-Kuo Tao; NASA-GSFC; Xia Feng; George Mason U.

Houser, P. R.; Lapenta, W.; Schiffer, R.

2008-05-01

122

LIFE CYCLE ANALYSIS OF HIGH-PERFORMANCE MONOCRYSTALLINE SILICON PHOTOVOLTAIC SYSTEMS: ENERGY PAYBACK TIMES AND NET ENERGY PRODUCTION VALUE  

E-print Network

LIFE CYCLE ANALYSIS OF HIGH-PERFORMANCE MONOCRYSTALLINE SILICON PHOTOVOLTAIC SYSTEMS: ENERGY performance, energy rating, c-Si, cost reduction 1 INTRODUCTION Life Cycle Analysis (LCA) is a framework for transparent and well-balanced LCA of all PV technologies, under the auspices of the International Energy

123

Large Scale Duty Cycle (LSDC) Project: Tractive Energy Analysis Methodology and Results from Long-Haul Truck Drive Cycle Evaluations  

SciTech Connect

This report addresses the approach that will be used in the Large Scale Duty Cycle (LSDC) project to evaluate the fuel savings potential of various truck efficiency technologies. The methods and equations used for performing the tractive energy evaluations are presented and the calculation approach is described. Several representative results for individual duty cycle segments are presented to demonstrate the approach and the significance of this analysis for the project. The report is divided into four sections, including an initial brief overview of the LSDC project and its current status. In the second section of the report, the concepts that form the basis of the analysis are presented through a discussion of basic principles pertaining to tractive energy and the role of tractive energy in relation to other losses on the vehicle. In the third section, the approach used for the analysis is formalized and the equations used in the analysis are presented. In the fourth section, results from the analysis for a set of individual duty cycle measurements are presented and different types of drive cycles are discussed relative to the fuel savings potential that specific technologies could bring if these drive cycles were representative of the use of a given vehicle or trucking application. Additionally, the calculation of vehicle mass from measured torque and speed data is presented and the accuracy of the approach is demonstrated.

LaClair, Tim J [ORNL

2011-05-01

124

Retrofitting conventional primary clarifiers to activated primary clarifiers to enhance nutrient removal and energy conservation in WWTPs in Beijing, China.  

PubMed

Biological nutrient removal requires sufficient carbon source. Meanwhile, the removal of organic matter in wastewater requires energy consumption in the aeration tank. Carbon source for nutrient removal in most wastewater treatment plants with conventional primary clarifier (CPC) is generally insufficient in China. In order to increase carbon source and to save energy, a part of the CPC may be retrofitted as an activated primary clarifier (APC). In this paper, a pilot scale experiment was conducted to examine the performance of primary sludge fermentation and its effect on nitrogen and phosphorus removal. Results show that the primary sludge fermentation in APC has produced a similar VFA/TP ratio but a higher BOD5/TN ratio compared with those in the CPC effluent, and the TN concentrations in the secondary effluent are at 8.0, 10.8, and 17.4 mg/L, while TP is at 0.45, 1.10, and 2.28 mg/L when the pilot test system was fed with (1) the APC effluent, (2) 50% from the APC effluent and 50% from the CPC effluent, and (3) the CPC effluent, respectively. Results also indicate that the BOD5/TN ratio is a more sensitive factor than the VFA/TP ratio for nutrient removal and energy conservation for the APC fermentation. PMID:21508549

Wang, Jia-wei; Zhang, Tian-zhu; Chen, Ji-ning; Hu, Zhi-rong

2011-01-01

125

Response Surface Energy Modeling of an Electric Vehicle over a Reduced Composite Drive Cycle  

SciTech Connect

Response surface methodology (RSM) techniques were applied to develop a predictive model of electric vehicle (EV) energy consumption over the Environmental Protection Agency's (EPA) standardized drive cycles. The model is based on measurements from a synthetic composite drive cycle. The synthetic drive cycle is a minimized statistical composite of the standardized urban (UDDS), highway (HWFET), and US06 cycles. The composite synthetic drive cycle is 20 minutes in length thereby reducing testing time of the three standard EPA cycles by over 55%. Vehicle speed and acceleration were used as model inputs for a third order least squared regression model predicting vehicle battery power output as a function of the drive cycle. The approach reduced three cycles and 46 minutes of drive time to a single test of 20 minutes. Application of response surface modeling to the synthetic drive cycle is shown to predict energy consumption of the three EPA cycles within 2.6% of the actual measured values. Additionally, the response model may be used to predict energy consumption of any cycle within the speed/acceleration envelope of the synthetic cycle. This technique results in reducing test time, which additionally provides a model that may be used to expand the analysis and understanding of the vehicle under consideration.

Jehlik, Forrest [Argonne National Laboratory (ANL)] [Argonne National Laboratory (ANL); LaClair, Tim J [ORNL] [ORNL

2014-01-01

126

A general ecosystem model for applications to primary productivity and carbon cycle studies in the global oceans  

NASA Astrophysics Data System (ADS)

We have developed a general 1-D multi-component ecosystem model that incorporates a skillful upper ocean mixed layer model based on second moment closure of turbulence. The model is intended for eventual incorporation into coupled 3-D physical-biogeochemical ocean models with potential applications to modeling and studying primary productivity and carbon cycling in the global oceans as well as to promote the use of chlorophyll concentrations, in concert with satellite-sensed ocean color, as a diagnostic tool to delineate circulation features in numerical circulation models. The model is nitrogen-based and the design is deliberately general enough and modular to enable many of the existing ecosystem model formulations to be simulated and hence model-to-model comparisons rendered feasible. In its more general form (GEM10), the model solves for nitrate, ammonium, dissolved nitrogen, bacteria and two size categories of phytoplankton, zooplankton and detritus, in addition to solving for dissolved inorganic carbon and total alkalinity to enable estimation of the carbon dioxide flux at the air-sea interface. Dissolved oxygen is another prognostic variable enabling air-sea exchange of oxygen to be calculated. For potential applications to HNLC regions where productivity is constrained by the availability of a trace constituent such as iron, the model carries the trace constituent as an additional prognostic variable. Here we present 1-D model simulations for the Black Sea, Station PAPA and the BATS site. The Black Sea simulations assimilate seasonal monthly SST, SSS and surface chlorophyll, and the seasonal modulations compare favorably with earlier work. Station PAPA simulations for 1975-1977 with GEM5 assimilating observed SST and a plausible seasonal modulation of surface chlorophyll concentration also compare favorably with earlier work and with the limited observations on nitrate and pCO 2 available. Finally, GEM5 simulations at BATS for 1985-1997 are consistent with the available time series. The simulations suggest that while it is generally desirable to employ a comprehensive ecosystem model with a large number of components when accurate depiction of the entire ecosystem is desirable, as is the prevailing practice, a simpler formulation such as GEM5 (N 2PZD model) combined with assimilation of remotely sensed SST and chlorophyll concentrations may suffice for incorporation into 3-D prediction models of primary productivity, upper ocean optical clarity and carbon cycling.

Kantha, Lakshmi H.

127

Building aggressively duty-cycled platforms to achieve energy efficiency  

NASA Astrophysics Data System (ADS)

Managing power consumption and improving energy efficiency is a key driver in the design of computing devices today. This is true for both battery-powered mobile devices as well as mains-powered desktop PCs and servers. In case of mobile devices, the focus of optimization is on energy efficiency to maximize battery lifetime. In case of mains-powered devices, we seek to optimize power consumption to reduce energy costs, thermal and environmental concerns. Traditionally, there are two main mechanisms to improve energy efficiency in systems: slowdown techniques that seek to reduce processor speed or radio power against the rate of work done, and shutdown techniques that seek to shut down specific components or subsystems -- such as processor, radio, memory -- to reduce power used by these components when not in use. The adverse effect of using these techniques is either reduced performance (e.g., increase in latency) and/or usability or loss of functionality. The thesis behind this dissertation is that improved energy efficiency can be achieved through system architectures that seek to design and exploit "collaboration" among heterogeneous but functionally similar subsystems. For instance, multiple radio interfaces with different power/performance characteristics can collaborate to provide an energy-efficient wireless communication subsystem. Furthermore, we show that in systems where such heterogeneity is not naturally present, we can introduce heterogeneous components to improve overall energy efficiency. We show that using collaboration, individual subsystems and even entire platforms can be shut down more aggressively to reduce energy consumption, while reducing adverse impacts on performance or usability. We have used collaboration to do energy efficient operation in several contexts. For battery powered mobile devices we show that wireless radios are the dominant power consumers, and then describe several techniques that use various heterogeneous radios present on these devices in a collaborative manner to improve their battery lifetime substantially, on average by two to three times and in some cases up to 8 times. First we present "Cell2Notify", a technique in which a lower power radio is used purely to wakeup a higher power radio. Next, we present "CoolSpots" and "SwitchR", systems that build a hierarchy of collaborative radios to choose the most appropriate radio interface, taking into account application characteristics as well as various energy and performance metrics. In the case of wall-powered desktop and laptop Personal Computers (PCs) we show that the dominant power consumers are the processors themselves. We then describe "Somniloquy", an architecture that augments a PC with a separate low power secondary processor that can perform some of the functions of the host PC on its behalf. We show that by using the primary processor (i.e. the PC) collaboratively with the secondary processor we can shut down PCs opportunistically, and as a result reduce the overall energy consumption by up to 80% in most cases.

Agarwal, Yuvraj

128

Cromer Cycle Air Conditioner: A Unique Air-Conditioner Desiccant Cycle to Enhance Dehumidification and Save Energy  

E-print Network

The Cromer cycle uses a desiccant to move moisture from the saturated air leaving an air conditioning (AC) cooling coil to the air returning to the AC unit from the conditioned space. This has the thermodynamic effect of reducing the overall energy...

Cromer, C. J.

2000-01-01

129

Open-cycle ocean thermal energy conversion surface-condenser design analysis and computer program  

NASA Astrophysics Data System (ADS)

This report documents a computer program for designing a surface condenser that condenses low-pressure steam in an ocean thermal energy conversion (OTEC) power plant. The primary emphasis is on the open-cycle (OC) OTEC power system, although the same condenser design can be used for conventional and hybrid cycles because of their highly similar operating conditions. In an OC-OTEC system, the pressure level is very low (deep vacuums), temperature differences are small, and the inlet noncondensable gas concentrations are high. Because current condenser designs, such as the shell-and-tube, are not adequate for such conditions, a plate-fin configuration is selected. This design can be implemented in aluminum, which makes it very cost-effective when compared with other state-of-the-art vacuum steam condenser designs. Support for selecting a plate-fin heat exchanger for OC-OTEC steam condensation can be found in the sizing (geometric details) and rating (heat transfer and pressure drop) calculations presented. These calculations are then used in a computer program to obtain all the necessary thermal performance details for developing design specifications for a plate-fin steam condenser.

Panchal, C. B.; Rabas, T. J.

1991-05-01

130

Life-cycle energy and environmental analysis of bioethanol production from cassava in Thailand  

Microsoft Academic Search

In this study, the life-cycle energy and environmental assessment was conducted for bioethanol production from cassava in Thailand. The scope covered all stages in the life cycle of bioethanol production including cultivating, chip processing, transportation and bioethanol conversion. The input–output data were collected at plantation sites and ethanol plants which included materials usage, energy consumption, and all emissions. From the

Seksan Papong; Pomthong Malakul

2010-01-01

131

A combined power cycle utilizing low-temperature waste heat and LNG cold energy  

Microsoft Academic Search

This paper has proposed a combined power system, in which low-temperature waste heat can be efficiently recovered and cold energy of liquefied natural gas (LNG) can be fully utilized as well. This system consists of an ammonia–water mixture Rankine cycle and an LNG power generation cycle, and it is modelled by considering mass, energy and species balances for every component

Xiaojun Shi; Defu Che

2009-01-01

132

Environmental Life-cycle Assessment of Passenger Transportation: A Detailed Methodology for Energy,  

E-print Network

Environmental Life-cycle Assessment of Passenger Transportation: A Detailed Methodology for Energy-Cycle Assessment of Passenger Transportation A Detailed Methodology for Energy, Greenhouse Gas, and Criteria of California, Berkeley Department of Civil and Environmental Engineering Institute of Transportation Studies

California at Berkeley, University of

133

Comparison of energy-based indicators used in life cycle assessment tools for buildings  

EPA Science Inventory

Traditionally, building rating systems focused on, among others, energy used during operational stage. Recently, there is a strong push by these rating systems to include the life cycle energy use of buildings, particularly using Life Cycle Assessment (LCA), by offering credits t...

134

Life-cycle energy analyses of electric vehicle storage batteries. Final report  

Microsoft Academic Search

The results of several life-cycle energy analyses of prospective electric vehicle batteries are presented. The batteries analyzed were: Nickel-zinc; Lead-acid; Nickel-iron; Zinc-chlorine; Sodium-sulfur (glass electrolyte); Sodium-sulfur (ceramic electrolyte); Lithium-metal sulfide; and Aluminum-air. A life-cycle energy analysis consists of evaluating the energy use of all phases of the battery's life, including the energy to build it, operate it, and any credits

D. Sullivan; T. Morse; P. Patel; S. Patel; J. Bondar; L. Taylor

1980-01-01

135

Survey and appraisal of primary future energy sources  

Microsoft Academic Search

Some rough estimates of the potential size of the following domestic alternative energy sources are calculated: Group 1 - wind power, water power, low-temperature solar energy, solar power through photosynthesis, tidal power, geothermal energy, and nuclear fission without breeders; Group 2 - nuclear fission with breeders, solar electric generation, and coal. The major conclusion is that the energy sources of

D. H. Root

1978-01-01

136

The Global Hydrologic and Energy Cycles: Suggestions for Studies in the Pre-Global Energy and Water Cycle Experiment (GEWEX) Period  

Microsoft Academic Search

Given the importance of a quantitative understanding of the way in which water and energy are moved from place to place and from component to component of the earth's climate system, it is necessary to obtain reliable estimates of the hydrologic and energy cycles in the global atmosphere. While a number of observing platforms designed to address this problem are

J. L. Kinter; J. Shukla

1990-01-01

137

Absorption Cycle Fundamentals and Applications Guidelines for Distillation Energy Savings  

E-print Network

The absorption cycle offers one of the most economic and widely applicable technologies for waste heat upgrading. It can use off-the-shelf hardware that is available now, at any required capacity rating. Fractional distillations, as a class...

Erickson, D. C.; Davidson, W. F.

1984-01-01

138

Red waters of Myrionecta rubra are biogeochemical hotspots for the Columbia River estuary with impacts on primary/secondary productions and nutrient cycles  

SciTech Connect

The localized impact of blooms of the mixotrophic ciliate Myrionecta rubra in the Columbia River estuary during 2007-2010 was evaluated with biogeochemical, light microscopy, physiological and molecular data. M. rubra affected surrounding estuarine nutrient cycles, as indicated by high and low concentrations of organic nutrients and inorganic nitrogen, respectively, associated with red waters. M. rubra blooms also altered the energy transfer pattern in patches of the estuarine water that contain the ciliate by creating areas characterized by high primary production and elevated levels of fresh autochthonous particulate organic matter, therefore shifting the trophic status in emergent red water areas of the estuary from net heterotrophy towards autotrophy. The pelagic estuarine bacterial community structure was unaffected by M. rubra abundance, but red waters of the ciliate do offer a possible link between autotrophic and heterotrophic processes since they were associated with elevated dissolved organic matter and enhanced microbial secondary production. Taken together these findings suggest that M. rubra red waters are biogeochemical hotspots of the Columbia River estuary.

Herfort, Lydie; Peterson, Tawnya D.; Prahl, Fredrick G.; McCue, Lee Ann; Needoba, Joe A.; Crump, Byron C.; Roegner, G. Curtis; Campbell, Victoria; Zuber, Peter A.

2012-02-29

139

Prospects for Nuclear Electric Propulsion Using Closed-Cycle Magnetohydrodynamic Energy Conversion  

NASA Technical Reports Server (NTRS)

Nuclear electric propulsion (NEP) has long been recognized as a major enabling technology for scientific and human exploration of the solar system, and it may conceivably form the basis of a cost-effective space transportation system suitable for space commerce. The chief technical obstacles to realizing this vision are the development of efficient, high-power (megawatt-class) electric thrusters and the development of low specific mass (less than 1 kg/kWe) power plants. Furthermore, comprehensive system analyses of multimegawatt class NEP systems are needed in order to critically assess mission capability and cost attributes. This Technical Publication addresses some of these concerns through a systematic examination of multimegawatt space power installations in which a gas-cooled nuclear reactor is used to drive a magnetohydrodynamic (MHD) generator in a closed-loop Brayton cycle. The primary motivation for considering MHD energy conversion is the ability to transfer energy out of a gas that is simply too hot for contact with any solid material. This has several intrinsic advantages including the ability to achieve high thermal efficiency and power density and the ability to reject heat at elevated temperatures. These attributes lead to a reduction in system specific mass below that obtainable with turbine-based systems, which have definite solid temperature limits for reliable operation. Here, the results of a thermodynamic cycle analysis are placed in context with a preliminary system analysis in order to converge on a design space that optimizes performance while remaining clearly within established bounds of engineering feasibility. MHD technology issues are discussed including the conceptual design of a nonequilibrium disk generator and opportunities for exploiting neutron-induced ionization mechanisms as a means of increasing electrical conductivity and enhancing performance and reliability. The results are then used to make a cursory examination of piloted Mars missions during the 2018 opportunity.

Litchford, R. J.; Bitteker, L. J.; Jones, J. E.

2001-01-01

140

Prognostic Utility of Cell Cycle Progression Score in Men With Prostate Cancer After Primary External Beam Radiation Therapy  

SciTech Connect

Purpose: To evaluate the prognostic utility of the cell cycle progression (CCP) score, a RNA signature based on the average expression level of 31 CCP genes, for predicting biochemical recurrence (BCR) in men with prostate cancer treated with external beam radiation therapy (EBRT) as their primary curative therapy. Methods and Materials: The CCP score was derived retrospectively from diagnostic biopsy specimens of men diagnosed with prostate cancer from 1991 to 2006 (n=141). All patients were treated with definitive EBRT; approximately half of the cohort was African American. Outcome was time from EBRT to BCR using the Phoenix definition. Median follow-up for patients without BCR was 4.8 years. Association with outcome was evaluated by Cox proportional hazards survival analysis and likelihood ratio tests. Results: Of 141 patients, 19 (13%) had BCR. The median CCP score for patient samples was 0.12. In univariable analysis, CCP score significantly predicted BCR (P=.0017). The hazard ratio for BCR was 2.55 for 1-unit increase in CCP score (equivalent to a doubling of gene expression). In a multivariable analysis that included Gleason score, prostate-specific antigen, percent positive cores, and androgen deprivation therapy, the hazard ratio for CCP changed only marginally and remained significant (P=.034), indicating that CCP provides prognostic information that is not provided by standard clinical parameters. With 10-year censoring, the CCP score was associated with prostate cancer-specific mortality (P=.013). There was no evidence for interaction between CCP and any clinical variable, including ethnicity. Conclusions: Among men treated with EBRT, the CCP score significantly predicted outcome and provided greater prognostic information than was available with clinical parameters. If validated in a larger cohort, CCP score could identify high-risk men undergoing EBRT who may need more aggressive therapy.

Freedland, Stephen J., E-mail: steve.freedland@duke.edu [Department of Surgery, Durham VA Medical Center, Durham, North Carolina (United States); Department of Surgery (Urology), Duke University School of Medicine, Durham, North Carolina (United States); Department of Pathology, Duke University School of Medicine, Durham, North Carolina (United States); Gerber, Leah [Department of Surgery, Durham VA Medical Center, Durham, North Carolina (United States); Department of Surgery (Urology), Duke University School of Medicine, Durham, North Carolina (United States); Department of Pathology, Duke University School of Medicine, Durham, North Carolina (United States); Reid, Julia; Welbourn, William; Tikishvili, Eliso; Park, Jimmy; Younus, Adib; Gutin, Alexander; Sangale, Zaina; Lanchbury, Jerry S. [Myriad Genetics, Inc, Salt Lake City, Utah (United States); Salama, Joseph K. [Department of Radiation Oncology, Durham VA Medical Center, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University School of Medicine, Durham, North Carolina (United States); Stone, Steven [Myriad Genetics, Inc, Salt Lake City, Utah (United States)

2013-08-01

141

Primary Photosynthetic Energy Conversion in Bacterial Reaction Centers  

NASA Astrophysics Data System (ADS)

The development of human societies is strongly influenced by the available energetic resources. In a period where the limitations of conventional fossil energy carriers become as evident as the often uncontrollable dangers of nuclear energy, one has to reconsider regenerative energy resources. Here photovoltaic or photochemical use of solar energy is an important approach. Since the early days of evolution some two billion years ago, the dominant energetic input into the life system on earth occurs via the conversion of solar energy performed in photosynthetic organisms. The fossil energy carriers that we use and waste today have been produced by photosynthesis over millions of years. In the race for an extended and versatile use of solar energy, semiconductorbased photovoltaic devices have been developed. However, even after decades of intense engineering they cannot serve as a competitive alternative to fossil energy. Under these circumstances new alternatives are required. One line of scientific development may use the operational principles of photosynthesis since photosynthesis is still our main energy source. In this respect, we will present results on the basic concepts of energy conversion in photosynthetic bacteria, which could be used as a guideline to alternative light energy conversion systems.

Zinth, Wolfgang; Wachtveitl, J.

142

Life-Cycle Greenhouse Gas and Energy Analyses of Algae Biofuels Production  

E-print Network

Life-Cycle Greenhouse Gas and Energy Analyses of Algae Biofuels Production Transportation Energy The Issue Algae biofuels directly address the Energy Commission's Public Interest Energy Research that both reduce oil dependency and reduce climate change. While algae fuels will minimize land use

143

Life cycle energy and environmental benefits of generating electricity from willow biomass  

Microsoft Academic Search

Biomass is a key renewable energy source expected to play an important role in US electricity production under stricter emission regulations and renewable portfolio standards. Willow energy crops are being developed in the northeast US as a fuel source for increasing biomass energy and bioproduct demands. A life cycle inventory is presented that characterizes the full cradle-to-grave energy and environmental

Martin C. Heller; Gregory A Keoleian; Margaret K. Mann; Timothy A. Volk

2004-01-01

144

Analysis on Correlation Relationship Between Life Cycle Greenhouse Gas Emission and Life Cycle Cost of Electricity Generation System for Energy Resources  

Microsoft Academic Search

\\u000a In this work, we analysed correlations between life cycle greenhouse gas (GHG) emissions and life cycle cost of energy resources.\\u000a Energy resources studied in this paper include coal, natural gas, nuclear power, hydropower, geothermal energy, wind power,\\u000a solar thermal energy, and solar photovoltaic energy, and all of them are used to generate electricity. We calculated the mean\\u000a values, ranges of

Heetae Kim; Tae Kyu Ahn

145

Life cycle cost-based risk model for energy performance contracting retrofits  

NASA Astrophysics Data System (ADS)

Buildings account for 41% of the primary energy consumption in the United States, nearly half of which is accounted for by commercial buildings. Among the greatest energy users are those in the municipalities, universities, schools, and hospitals (MUSH) market. Correctional facilities are in the upper half of all commercial building types for energy intensity. Public agencies have experienced reduced capital budgets to fund retrofits; this has led to the increased use of energy performance contracts (EPC), which are implemented by energy services companies (ESCOs). These companies guarantee a minimum amount of energy savings resulting from the retrofit activities, which in essence transfers performance risk from the owner to the contractor. Building retrofits in the MUSH market, especially correctional facilities, are well-suited to EPC, yet despite this potential and their high energy intensities, efficiency improvements lag behind that of other public building types. Complexities in project execution, lack of support for data requests and sub-metering, and conflicting project objectives have been cited as reasons for this lag effect. As a result, project-level risks must be understood in order to support wider adoption of retrofits in the public market, in particular the correctional facility sub-market. The goal of this research is to understand risks related to the execution of energy efficiency retrofits delivered via EPC in the MUSH market. To achieve this goal, in-depth analysis and improved understanding was sought with regard to ESCO risks that are unique to EPC in this market. The proposed work contributes to this understanding by developing a life cycle cost-based risk model to improve project decision making with regard to risk control and reduction. The specific objectives of the research are: (1) to perform an exploratory analysis of the EPC retrofit process and identify key areas of performance risk requiring in-depth analysis; (2) to construct a framework describing the sources of and mitigation strategies employed for assessing key risks in EPC retrofits; (3) to develop a strategy for analyzing and evaluating risks for EPC retrofits focused on managing expected costs throughout the project life cycle, and use data collected through this strategy to develop and parameterize a risk model; and (4) to demonstrate the applicability of the proposed life cost-based risk model through a pilot application to a case study site. Five major contributions to the body of knowledge resulting from the research include: (1) a consensus-based assessment of ESCO risk management; (2) characterization of EPC retrofit risks borne by ESCOs; (3) an empirical evaluation of scenario failure mode and effects analysis and its application to this domain; (4) development and pilot application of a life cycle cost-based risk model; and (5) future expansion of the research approach to other domains. The researcher envisions that full implementation of the research will further encourage the growth of the energy services industry, and support focused retrofits in complex building types that typically can benefit the most from such work. Ultimately, this will reduce the energy consumption of public sector buildings to levels that are more fitting with the global principles of sustainability and responsible management of constrained resources.

Berghorn, George H.

146

Development and use of the GREET model to estimate fuel-cycle energy use and emissions of various transportation technologies and fuels  

SciTech Connect

This report documents the development and use of the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The model, developed in a spreadsheet format, estimates the full fuel- cycle emissions and energy use associated with various transportation fuels for light-duty vehicles. The model calculates fuel-cycle emissions of five criteria pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides, sulfur oxides, and particulate matter measuring 10 microns or less) and three greenhouse gases (carbon dioxide, methane, and nitrous oxide). The model also calculates the total fuel-cycle energy consumption, fossil fuel consumption, and petroleum consumption using various transportation fuels. The GREET model includes 17 fuel cycles: petroleum to conventional gasoline, reformulated gasoline, clean diesel, liquefied petroleum gas, and electricity via residual oil; natural gas to compressed natural gas, liquefied petroleum gas, methanol, hydrogen, and electricity; coal to electricity; uranium to electricity; renewable energy (hydrogen, solar energy, and wind) to electricity; corn, woody biomass, and herbaceous biomass to ethanol; and landfill gases to methanol. This report presents fuel-cycle energy use and emissions for a 2000 model-year car powered by each of the fuels that are produced from the primary energy sources considered in the study.

Wang, M.Q.

1996-03-01

147

ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION  

SciTech Connect

A recuperative bayonet reactor design for the high-temperature sulfuric acid decomposition step in sulfur-based thermochemical hydrogen cycles was evaluated using pinch analysis in conjunction with statistical methods. The objective was to establish the minimum energy requirement. Taking hydrogen production via alkaline electrolysis with nuclear power as the benchmark, the acid decomposition step can consume no more than 450 kJ/mol SO{sub 2} for sulfur cycles to be competitive. The lowest value of the minimum heating target, 320.9 kJ/mol SO{sub 2}, was found at the highest pressure (90 bar) and peak process temperature (900 C) considered, and at a feed concentration of 42.5 mol% H{sub 2}SO{sub 4}. This should be low enough for a practical water-splitting process, even including the additional energy required to concentrate the acid feed. Lower temperatures consistently gave higher minimum heating targets. The lowest peak process temperature that could meet the 450-kJ/mol SO{sub 2} benchmark was 750 C. If the decomposition reactor were to be heated indirectly by an advanced gas-cooled reactor heat source (50 C temperature difference between primary and secondary coolants, 25 C minimum temperature difference between the secondary coolant and the process), then sulfur cycles using this concept could be competitive with alkaline electrolysis provided the primary heat source temperature is at least 825 C. The bayonet design will not be practical if the (primary heat source) reactor outlet temperature is below 825 C.

Gorensek, M.; Edwards, T.

2009-06-11

148

Off-design performance of integrated waste-to-energy, combined cycle plants  

Microsoft Academic Search

This paper focuses on the off-design operation of plants where a waste-to-energy (WTE) system fed with municipal solid waste (MSW) is integrated with a natural gas-fired combined cycle (CC). Integration is accomplished by sharing the steam cycle: saturated steam generated in a MSW grate combustor is exported to the heat recovery steam generator (HRSG) of the combined cycle, where it

Stefano Consonni; Paolo Silva

2007-01-01

149

Thermodynamics of greenhouse systems for the northern latitudes: analysis, evaluation and prospects for primary energy saving.  

PubMed

In Flanders and the Netherlands greenhouse production systems produce economically important quantities of vegetables, fruit and ornamentals. Indoor environmental control has resulted in high primary energy use. Until now, the research on saving primary energy in greenhouse systems has been mainly based on analysis of energy balances. However, according to the thermodynamic theory, an analysis based on the concept of exergy (free energy) and energy can result in new insights and primary energy savings. Therefore in this paper, we analyse the exergy and energy of various processes, inputs and outputs of a general greenhouse system. Also a total system analysis is then performed by linking the exergy analysis with a dynamic greenhouse climate growth simulation model. The exergy analysis indicates that some processes ("Sources") lie at the origin of several other processes, both destroying the exergy of primary energy inputs. The exergy destruction of these Sources is caused primarily by heat and vapour loss. Their impact can be compensated by exergy input from heating, solar radiation, or both. If the exergy destruction of these Sources is reduced, the necessary compensation can also be reduced. This can be accomplished through insulating the greenhouse and making the building more airtight. Other necessary Sources, namely transpiration and loss of CO2, have a low exergy destruction compared to the other Sources. They are therefore the best candidate for "pump" technologies ("vapour heat pump" and "CO2 pump") designed to have a low primary energy use. The combination of these proposed technologies results in an exergy efficient greenhouse with the highest primary energy savings. It can be concluded that exergy analyses add additional information compared to only energy analyses and it supports the development of primary energy efficient greenhouse systems. PMID:23474336

Bronchart, Filip; De Paepe, Michel; Dewulf, Jo; Schrevens, Eddie; Demeyer, Peter

2013-04-15

150

NASA Contributions to Improve Understanding of Extreme Events in the Global Energy and Water Cycle  

NASA Technical Reports Server (NTRS)

The U.S. Climate Change Science Program (CCSP) has established the water cycle goals of the Nation's climate change program. Accomplishing these goals will require, in part, an accurate accounting of the key reservoirs and fluxes associated with the global water and energy cycle, including their spatial and temporal variability. through integration of all necessary observations and research tools, To this end, in conjunction with NASA's Earth science research strategy, the overarching long-term NASA Energy and Water Cycle Study (NEWS) grand challenge can he summarized as documenting and enabling improved, observationally based, predictions of water and energy cycle consequences of Earth system variability and change. This challenge requires documenting and predicting trends in the rate of the Earth's water and energy cycling that corresponds to climate change and changes in the frequency and intensity of naturally occurring related meteorological and hydrologic events, which may vary as climate may vary in the future. The cycling of water and energy has obvious and significant implications for the health and prosperity of our society. The importance of documenting and predicting water and energy cycle variations and extremes is necessary to accomplish this benefit to society.

Lapenta, William M.

2008-01-01

151

[Life cycle assessment of energy consumption and greenhouse gas emissions of cellulosic ethanol from corn stover].  

PubMed

Life Cycle Assessment (LCA) is the only standardized tool currently used to assess environmental loads of products and processes. The life cycle analysis, as a part of LCA, is a useful and powerful methodology for studying life cycle energy efficiency and life cycle GHG emission. To quantitatively explain the potential of energy saving and greenhouse gas (GHG) emissions reduction of corn stover-based ethanol, we analyzed life cycle energy consumption and GHG emissions of corn stover-based ethanol by the method of life cycle analysis. The processes are dilute acid prehydrolysis and enzymatic hydrolysis. The functional unit was defined as 1 km distance driven by the vehicle. Results indicated: compared with gasoline, the corn stover-based E100 (100% ethanol) and E10 (a blend of 10% ethanol and 90% gasoline by volume) could reduce life cycle fossil energy consumption by 79.63% and 6.25% respectively, as well as GHG emissions by 53.98% and 6.69%; the fossil energy consumed by biomass stage was 68.3% of total fossil energy input, N-fertilizer and diesel were the main factors which contributed 45.78% and 33.26% to biomass stage; electricity production process contributed 42.06% to the net GHG emissions, the improvement of technology might reduce emissions markedly. PMID:21650036

Tian, Wang; Liao, Cuiping; Li, Li; Zhao, Daiqing

2011-03-01

152

Developing Primary School Children's Understanding of Energy Waste.  

ERIC Educational Resources Information Center

Studies 34 elementary school children's understanding of five aspects of energy waste and the ways in which these conceptions develop following teaching. Concludes that the children had good prior awareness of some behaviors that save energy, but their reasons for thinking this were based largely on everyday intuitive ideas that involved…

Kruger, Colin; Summers, Mike

2000-01-01

153

Life cycle model of alternative fuel vehicles: emissions, energy, and cost trade-offs  

Microsoft Academic Search

This paper describes a life cycle model for performing level-playing field comparisons of the emissions, costs, and energy efficiency trade-offs of alternative fuel vehicles (AFV) through the fuel production chain and over a vehicle lifetime. The model is an improvement over previous models because it includes the full life cycle of the fuels and vehicles, free of the distorting effects

Jeremy Hackney; Richard de Neufville

2001-01-01

154

[Comment on ``GEWEX: The Global Energy and Water Cycle Experiment''] Global water balance uncertainty  

Microsoft Academic Search

I am surprised by the opening remarks of Moustafa T. Chahine in his article, ``GEWEX: The Global Energy and Water Cycle Experiment'' (Eos, January 14, 1992, p. 9), which stated that ``our quantitative knowledge of the global hydrological cycle remains surprisingly poor. Evaporation minus precipitation or, similarly, the net flow of water from land to oceans and the net advection

Turgot Dincer

1992-01-01

155

The Role of the Global Energy and Water Cycle EXperiment (GEWEX) in Advancing Hydrologic Sciences  

Microsoft Academic Search

The NRC study which resulted in the 1991 ``Opportunities in the Hydrologic Sciences'' report, discussed the importance of integrated and comprehensive programs that addressed data, modeling, and process studies of the components of the hydrologic process cycle. Simultaneously, an international effort was being organized that became known as the Global Energy and Water Cycle EXperiment (GEWEX), an initiative of the

S. Sorooshian; M. T. Chahine; T. P. Ackerman; R. G. Lawford; P. D. Try; P. J. van Oevelen

2009-01-01

156

Cathode for use in high energy primary thionyl chloride cell systems and high energy primary thionyl chloride cell systems including the cathode  

NASA Astrophysics Data System (ADS)

A cathode is provided for use in high energy primary lithium-thionyl chloride cell systems or calcium-thionyl chloride cell systems. The cathode comprises an expanded metallic current collector screen into which has been pasted a mixture of a low surface area conductive carbon black and a high surface area conductive carbon black previously mixed with a binder.

Walker, C. W., Jr.; Wade, W. L., Jr.; Binder, M.; Gilman, S.

1985-08-01

157

Results of the Collaborative Energy and Water Cycle Information Services (CEWIS) Workshop on Heterogeneous Dataset Analysis Preparation  

Microsoft Academic Search

In support of the NASA Energy and Water Cycle Study (NEWS), the Collaborative Energy and Water Cycle Information Services (CEWIS), sponsored by NEWS Program Manager Jared Entin, was initiated to develop an evolving set of community-based data and information services that would facilitate users to locate, access, and bring together multiple distributed heterogeneous energy and water cycle datasets. The CEWIS

S. J. Kempler; W. L. Teng; J. G. Acker; D. R. Belvedere; Z. Liu; G. G. Leptoukh

2010-01-01

158

Comparison of Life Cycle Emissions and Energy Consumption for  

E-print Network

maintenance and disposal/treatment systems can be expensive. Research suggests that the life cycle costs of MWF systems can range from 4-16% of metals manufacturing costs (3). Water-based MWFs have been widely/or deliver minimum quantities of lubricant in gas rather than water, with the former strategy being more

Clarens, Andres

159

GEWEX - The Global Energy and Water Cycle Experiment  

Microsoft Academic Search

GEWEX, which is part of the World Climate Research Program, has as its goal an order-of-magnitude improvement in the ability to model global precipitation and evaporation and furnish an accurate assessment of the sensitivity of atmospheric radiation and clouds. Attention will also be given to the response of the hydrological cycle and water resources to climate change. GEWEX employs a

M. T. Chahine

1992-01-01

160

Energy and Water Cycle Components in Regional Forecasts Final Report  

Microsoft Academic Search

For the first period of the special project we investigated the characteristics of the water cycle com- ponents simulated with the regional model REMO. For the second period our studies focussed on the high resolution regional model HRM. REMO is based on the former Europamodell of the Ger- man Weather Service (DWD), whereas HRM is a regional version of the

Burkhardt Rockel

161

The tropical water and energy cycles in a cumulus ensemble model. Part 1: Equilibrium climate  

NASA Technical Reports Server (NTRS)

A cumulus ensemble model is used to study the tropical water and energy cycles and their role in the climate system. The model includes cloud dynamics, radiative processes, and microphysics that incorporate all important production and conversion processes among water vapor and five species of hydrometeors. Radiative transfer in clouds is parameterized based on cloud contents and size distributions of each bulk hydrometeor. Several model integrations have been carried out under a variety of imposed boundary and large-scale conditions. In Part 1 of this paper, the primary focus is on the water and heat budgets of the control experiment, which is designed to simulate the convective - radiative equilibrium response of the model to an imposed vertical velocity and a fixed sea surface temperature at 28 C. The simulated atmosphere is conditionally unstable below the freezing level and close to neutral above the freezing level. The equilibrium water budget shows that the total moisture source, M(sub s), which is contributed by surface evaporation (0.24 M(sub s)) and the large-scale advection (0.76 M(sub s)), all converts to mean surface precipitation bar-P(sub s). Most of M(sub s) is transported verticaly in convective regions where much of the condensate is generated and falls to surface (0.68 bar-P(sub s)). The remaining condensate detrains at a rate of 0.48 bar-P(sub s) and constitutes 65% of the source for stratiform clouds above the melting level. The upper-level stratiform cloud dissipates into clear environment at a rate of 0.14 bar-P(sub s), which is a significant moisture source comparable to the detrained water vapor (0.15 bar-P(sub s)) to the upper troposphere from convective clouds. In the lower troposphere, stratiform clouds evaporate at a rate of 0.41 bar-P(sub s), which is a more dominant moisture source than surface evaporation (0.22 bar-P(sub s)). The precipitation falling to the surface in the stratiform region is about 0.32 bar-P(sub s). The associated latent heating in the water cycle is the dominant source in the heat budget that generates a net upward motion in convective regions, upper stratiform regions (above the freezing level), and a downward motion in the lower stratiform regions. The budgets reveal a cycle of water and energy resulted from radiation-dynamic-convection interactions that maintain equilibrium of the atmosphere.

Sui, C. H.; Lau, K. M.; Tao, W. K.; Simpson, J.

1994-01-01

162

BCR targets cyclin D2 via Btk and the p85? subunit of PI3-K to induce cell cycle progression in primary mouse B cells  

Microsoft Academic Search

The p85? subunit of PI3-K and Btk are two crucial components of the B-cell receptor (BCR) signalling pathway. In the present study, we showed that primary splenic B cells from p85? null and xid (Btk-deficient) mice fail to induce cyclin D2 expression and enter early G1, but not S phase of the cell cycle in response to BCR engagement. Furthermore,

Janet Glassford; Inês Soeiro; Sara M Skarell; Lolita Banerji; Mary Holman; Gerry G B Klaus; Takashi Kadowaki; Shigeo Koyasu; Eric W-F Lam; EW-F Lam

2003-01-01

163

Global Energy and Water Cycle Experiment (GEWEX) and the Continental-scale International Project (GCIP)  

NASA Technical Reports Server (NTRS)

A discussion of the objectives of the Global Energy and Water Cycle Experiment (GEWEX) and the Continental-scale International Project (GCIP) is presented in vugraph form. The objectives of GEWEX are as follows: determine the hydrological cycle by global measurements; model the global hydrological cycle; improve observations and data assimilation; and predict response to environmental change. The objectives of GCIP are as follows: determine the time/space variability of the hydrological cycle over a continental-scale region; develop macro-scale hydrologic models that are coupled to atmospheric models; develop information retrieval schemes; and support regional climate change impact assessment.

Vane, Deborah

1993-01-01

164

CAESCAP: A computer code for compressed-air energy-storage-plant cycle analysis  

NASA Astrophysics Data System (ADS)

The analysis code, CAESCAP, was developed as an aid in comparing and evaluating proposed compressed air energy storage (CAES) cycles. Input consists of component parameters and working fluid conditions at points along a cycle. The code calculates thermodynamic properties at each point and then calculates overall cycle performance. Working fluid capabilities include steam, air, nitrogen, and parahydrogen. The CAESCAP code was used to analyze a variety of CAES cycles. The combination of straightforward input and flexible design make the code easy and inexpensive to use.

Fort, J. A.

1982-10-01

165

Life-cycle energy analyses of electric vehicle storage batteries. Final report  

SciTech Connect

The results of several life-cycle energy analyses of prospective electric vehicle batteries are presented. The batteries analyzed were: Nickel-zinc; Lead-acid; Nickel-iron; Zinc-chlorine; Sodium-sulfur (glass electrolyte); Sodium-sulfur (ceramic electrolyte); Lithium-metal sulfide; and Aluminum-air. A life-cycle energy analysis consists of evaluating the energy use of all phases of the battery's life, including the energy to build it, operate it, and any credits that may result from recycling of the materials in it. The analysis is based on the determination of three major energy components in the battery life cycle: Investment energy, i.e., The energy used to produce raw materials and to manufacture the battery; operational energy i.e., The energy consumed by the battery during its operational life. In the case of an electric vehicle battery, this energy is the energy required (as delivered to the vehicle's charging circuit) to power the vehicle for 100,000 miles; and recycling credit, i.e., The energy that could be saved from the recycling of battery materials into new raw materials. The value of the life-cycle analysis approach is that it includes the various penalties and credits associated with battery production and recycling, which enables a more accurate determination of the system's ability to reduce the consumption of scarce fuels. The analysis of the life-cycle energy requirements consists of identifying the materials from which each battery is made, evaluating the energy needed to produce these materials, evaluating the operational energy requirements, and evaluating the amount of materials that could be recycled and the energy that would be saved through recycling. Detailed descriptions of battery component materials, the energy requirements for battery production, and credits for recycling, and the operational energy for an electric vehicle, and the procedures used to determine it are discussed.

Sullivan, D; Morse, T; Patel, P; Patel, S; Bondar, J; Taylor, L

1980-12-01

166

Generation of available potential energy and the energy cycle during the global weather experiment  

NASA Technical Reports Server (NTRS)

Two major themes were pursued during this research period. The first of these involved examining the impacts of satellite-based data and the forecast model used by the Goddard Laboratory for Atmospheres (GLA) on general circulation statistics. For the other major topic, the diabatic heating fields produced by GLA were examined for one month during the FGGE First Special Observing Period. As part of that effort, the three-dimensional distribution of the four component heating fields were studied, namely those due to shortwave radiation, Q sub SW, longwave radiation, Q sub LW, sensible heating, Q sub S, and latent heating, Q sub L. These components were calculated as part of the GLA analysis/forecast system and archived every quarter day; from these archives cross products with temperature were computed to enable the direct calculation of certain terms of the large-scale atmospheric energy cycle, namely those involving the generation of available potential energy (APE). The decision to archive the diabatic heating components separately has enabled researchers to study the role of the various processes that drive the energy cycle of the atmosphere.

Salstein, D. A.; Rosen, R. D.

1986-01-01

167

Evaluating energy dissipation during expansion in a refrigeration cycle using flue pipe acoustic resonators  

E-print Network

This research evaluates the feasibility of using a flue pipe acoustic resonator to dissipate energy from a refrigerant stream in order to achieve greater cooling power from a cryorefrigeration cycle. Two models of the ...

Luckyanova, Maria N. (Maria Nickolayevna)

2008-01-01

168

Mutually compensative pseudo solutions of primary energy spectra in the knee region  

E-print Network

The problem of the uniqueness of solutions during the evaluation of primary energy spectra in the knee region using an extensive air shower (EAS) data set and the EAS inverse approach is investigated. It is shown that the unfolding of primary energy spectra in the knee region leads to mutually compensative pseudo solutions. These solutions may be the reason for the observed disagreements in the elementary energy spectra of cosmic rays in the 1-100 PeV energy range obtained from different experiments.

S. V. Ter-Antonyan

2007-06-27

169

Energy consumption at business cycle horizons: The case of the United States  

Microsoft Academic Search

In this paper, we propose a simple extension to a Keynesian type macro model by augmenting it with energy consumption. We show the relationship between energy consumption and output in a macroeconomic setting and ask the question: Do permanent shocks dominate changes in energy consumption and output at business cycle horizons for the United States? To achieve the goal of

Paresh Kumar Narayan; Seema Narayan; Russell Smyth

2011-01-01

170

Adaptive Control of Duty Cycling in Energy-Harvesting Wireless Sensor Networks  

E-print Network

Adaptive Control of Duty Cycling in Energy-Harvesting Wireless Sensor Networks Christopher M wireless sensor network deployments are using harvested environmental energy to extend system lifetime. Because the temporal profiles of such energy sources exhibit great variability due to dynamic weather

Massachusetts at Amherst, University of

171

Electron showers of high primary energy in lead.  

NASA Technical Reports Server (NTRS)

The development of electron cascade showers in a lead-scintillator sandwich of 8 plastic scintillators in about 20 radiation lengths of lead has been investigated. This detector, which was used for cosmic-ray studies, has been calibrated with electrons with energies from 2 to 15 GeV at SLAC. Measured shower profiles are presented, and expressions are given which allow an extrapolation of the measured data up to energies around 1000 GeV. The results are compared with analytical shower theories and Monte Carlo calculations.

Mueller, D.

1972-01-01

172

Life-cycle energy and environmental analysis of bioethanol production from cassava in Thailand.  

PubMed

In this study, the life-cycle energy and environmental assessment was conducted for bioethanol production from cassava in Thailand. The scope covered all stages in the life cycle of bioethanol production including cultivating, chip processing, transportation and bioethanol conversion. The input-output data were collected at plantation sites and ethanol plants which included materials usage, energy consumption, and all emissions. From the energy analysis, the results show that cassava-based bioethanol has a negative net energy value with an energy ratio was less than 1, indicating a net energy loss. For the environmental performance, the results show that throughout the life cycle of bioethanol, the conversion stage contributes most to the environmental impacts which is due to the use of coal for power and steam production in the bioethanol plants. It is suggested that a partial substitution of coal with biogas produced from existing wastewater treatment could lead to a significant reduction in the environmental impact. PMID:19766487

Papong, Seksan; Malakul, Pomthong

2010-01-01

173

Life-cycle energy savings potential from aluminum-intensive vehicles  

Microsoft Academic Search

The life-cycle energy and fuel-use impacts of US-produced aluminum-intensive passenger cars and passenger trucks are assessed. The energy analysis includes vehicle fuel consumption, material production energy, and recycling energy. A model that stimulates market dynamics was used to project aluminum-intensive vehicle market shares and national energy savings potential for the period between 2005 and 2030. We conclude that there is

F. Stodolsky; A. Vyas; R. Cuenca; L. Gaines

1995-01-01

174

Sorting through the many total-energy-cycle pathways possible with early plug-in hybrids  

Microsoft Academic Search

Using the 'total energy cycle' methodology, we compare U.S. near term (to 2015) alternative pathways for converting energy to light-duty vehicle kilometers of travel (VKT) in plug-in hybrids (PHEVs), hybrids (HEVs), and conventional vehicles (CVs). For PHEVs, we present total energy-per-unit-of-VKT information two ways (1) energy from the grid during charge depletion (CD); (2) energy from stored on-board fossil fuel

L. Gaines; A. Burnham; A. Rousseau; D. Santini

2008-01-01

175

Optimal cycling time trial position models: aerodynamics versus power output and metabolic energy.  

PubMed

The aerodynamic drag of a cyclist in time trial (TT) position is strongly influenced by the torso angle. While decreasing the torso angle reduces the drag, it limits the physiological functioning of the cyclist. Therefore the aims of this study were to predict the optimal TT cycling position as function of the cycling speed and to determine at which speed the aerodynamic power losses start to dominate. Two models were developed to determine the optimal torso angle: a 'Metabolic Energy Model' and a 'Power Output Model'. The Metabolic Energy Model minimised the required cycling energy expenditure, while the Power Output Model maximised the cyclists? power output. The input parameters were experimentally collected from 19 TT cyclists at different torso angle positions (0-24°). The results showed that for both models, the optimal torso angle depends strongly on the cycling speed, with decreasing torso angles at increasing speeds. The aerodynamic losses outweigh the power losses at cycling speeds above 46km/h. However, a fully horizontal torso is not optimal. For speeds below 30km/h, it is beneficial to ride in a more upright TT position. The two model outputs were not completely similar, due to the different model approaches. The Metabolic Energy Model could be applied for endurance events, while the Power Output Model is more suitable in sprinting or in variable conditions (wind, undulating course, etc.). It is suggested that despite some limitations, the models give valuable information about improving the cycling performance by optimising the TT cycling position. PMID:24726654

Fintelman, D M; Sterling, M; Hemida, H; Li, F-X

2014-06-01

176

Energy from CO2 using capacitive electrodes - a model for energy extraction cycles.  

PubMed

A model is presented for the process of harvesting electrical energy from CO2 emissions using capacitive cells. The principle consists of controlling the mixing process of a concentrated CO2 gas stream with a dilute CO2 gas stream (as, for example, exhaust gas and air), thereby converting part of the released mixing energy into electrical energy. The model describes the transient reactive transport of CO2 gas absorbed in water or in monoethanolamine (MEA) solutions, under the assumption of local chemical equilibrium. The model combines the selective transport of ions through ion-exchange membranes, the accumulation of charge in the porous carbon electrodes and the coupling between the ionic current and the produced electrical current and power. We demonstrate that the model can be used to calculate the energy that can be extracted by mixing concentrated and dilute CO2 containing gas streams. Our calculation results for the process using MEA solutions have various counterintuitive features, including: 1. When dynamic equilibrium is reached in the cyclical process, the electrical charge in the anode is negative both during charging and discharging; 2. Placing an anion-exchange membrane (AEM) in the system is not required, the energy per cycle is just as large with or without an AEM. PMID:25525977

Paz-Garcia, J M; Dykstra, J E; Biesheuvel, P M; Hamelers, H V M

2015-03-15

177

The U.S. Department of Energy`s integrated gasification combined cycle research, development and demonstration program  

SciTech Connect

Historically, coal has played a major role as a fuel source for power generation both domestically and abroad. Despite increasingly stringent environmental constraints and affordable natural gas, coal will remain one of the primary fuels for producing electricity. This is due to its abundance throughout the world, low price, ease of transport an export, decreasing capital cost for coal-based systems, and the need to maintain fuel diversity. Recognizing the role coal will continue to play, the US Department of Energy (DOE) is working in partnership with industry to develop ways to use this abundant fuel resource in a manner that is more economical, more efficient and environmentally superior to conventional means to burn coal. The most promising of these technologies is integrated gasification combined cycle (IGCC) systems. Although IGCC systems offer many advantages, there are still several hurdles that must be overcome before the technology achieves widespread commercial acceptance. The major hurdles to commercialization include reducing capital and operating costs, reducing technical risk, demonstrating environmental and technical performance at commercial scale, and demonstrating system reliability and operability. Overcoming these hurdles, as well as continued progress in improving system efficiency, are the goals of the DOE IGCC research, development and demonstrate (RD and D) program. This paper provides an overview of this integrated RD and D program and describes fundamental areas of technology development, key research projects and their related demonstration scale activities.

Brdar, R.D.; Cicero, D.C.

1996-07-01

178

The photoenzymatic cycle of NADPH: protochlorophyllide oxidoreductase in primary bean leaves ( Phaseolus vulgaris ) during the first days of photoperiodic growth  

Microsoft Academic Search

The photoenzymatic cycle of the light-dependent NADPH:protochlorophyllide oxidoreductase (LPOR) was investigated in situ during\\u000a early stages of development of bean leaves under light-dark cycles (LDC). In the experimental system used in this study, prolamellar\\u000a bodies developed during night periods and disappeared during light periods. This was accompanied by changes in the photoactive\\u000a to non-photoactive Pchlide ratio, which was higher at the

Benoît Schoefs; Fabrice Franck

2008-01-01

179

GEWEX - The Global Energy and Water Cycle Experiment  

SciTech Connect

GEWEX, which is part of the World Climate Research Program, has as its goal an order-of-magnitude improvement in the ability to model global precipitation and evaporation and furnish an accurate assessment of the sensitivity of atmospheric radiation and clouds. Attention will also be given to the response of the hydrological cycle and water resources to climate change. GEWEX employs a single program to coordinate all aspects of climatology from model development to the deployment and operation of observational systems. GEWEX will operate over the next two decades. 5 refs.

Chahine, M.T. (JPL, Pasadena, CA (United States))

1992-01-01

180

GEWEX - The Global Energy and Water Cycle Experiment  

NASA Technical Reports Server (NTRS)

GEWEX, which is part of the World Climate Research Program, has as its goal an order-of-magnitude improvement in the ability to model global precipitation and evaporation and furnish an accurate assessment of the sensitivity of atmospheric radiation and clouds. Attention will also be given to the response of the hydrological cycle and water resources to climate change. GEWEX employs a single program to coordinate all aspects of climatology from model development to the deployment and operation of observational systems. GEWEX will operate over the next two decades.

Chahine, Moustafa T.

1992-01-01

181

A Feasibility Study of CO2-Based Rankine Cycle Powered by Solar Energy  

NASA Astrophysics Data System (ADS)

An experiment study was carried out in order to investigate feasibility of CO2-based Rankine cycle powered by solar energy. The proposed cycle is to achieve a cogeneration of heat and power, which consists of evacuated solar tube collectors, power generating turbine, heat recovery system, and feed pump. The Rankine cycle of the system utilizes solar collectors to convert CO2 into high-temperature supercritical state, used to drive a turbine and produce electrical power. The cycle also recovers thermal energy, which can be used for absorption refrigerator, air conditioning, hot water supply so on for a building. A set of experimental set-up was constructed to investigate the performance of the CO2-based Rankine cycle. The results show the cycle can achieve production of heat and power with reasonable thermodynamics efficiency and has a great potential of the application of the CO2-based Rankine cycle powered by solar energy. In addition, some research interests related to the present study will also be discussed in this paper.

Zhang, Xin-Rong; Yamaguchi, Hiroshi; Fujima, Katsumi; Enomoto, Masatoshi; Sawada, Noboru

182

Standard levels of energy losses in primary distribution circuits for SCADA application  

Microsoft Academic Search

The reduction of energy losses in distribution systems is an important issue during planning and operation with important technical and economical implications. The standard or normal level of energy losses in primary distribution circuits is an important indicator for the planning and operation of electrical distribution circuits. It depends upon a number of parameters and variables, such as the nominal

H. M. Khodr; J. Molea; I. Garcia; C. Hidalgo; P. C. Paiva; J. M. Yusta; Alberto J. Urdaneta

2002-01-01

183

Life-cycle energy analyses of electric vehicle storage batteries  

Microsoft Academic Search

Nickel-zinc, lead-acid, nickel-iron, zinc-chlorine, sodium-sulfur (glass electrolyte), sodium-sulfur (ceramic electrolyte), lithium-metal sulfide, and aluminum-air batteries were studied in order to evaluate the energy used to produce the raw materials and to manufacture the battery, the energy consumed by the battery during its operational life, and the energy that could be saved from the recycling of battery materials into new raw

D. Sullivan; T. Morse; P. Patel; S. Patel; J. Bondar; L. Taylor

1980-01-01

184

Carbon Cycles  

NSDL National Science Digital Library

Students are introduced to the concept of energy cycles by learning about the carbon cycle. They learn how carbon atoms travel through the geological (ancient) carbon cycle and the biological/physical carbon cycle. They consider how human activities disturb the carbon cycle by emitting carbon dioxide into the atmosphere. They discuss how engineers and scientists are working to reduce carbon dioxide emissions. Lastly, students consider how they can help the world through simple energy conservation measures.

2014-09-18

185

Sustainable Energy Solutions Task 3.0:Life-Cycle Database for Wind Energy Systems  

SciTech Connect

EXECUTIVE SUMMARY The benefits of wind energy had previously been captured in the literature at an overview level with relatively low transparency or ability to understand the basis for that information. This has limited improvement and decision-making to larger questions such as wind versus other electrical sources (such as coal-fired plants). This research project has established a substantially different approach which is to add modular, high granularity life cycle inventory (lci) information that can be used by a wide range of decision-makers, seeking environmental improvement. Results from this project have expanded the understanding and evaluation of the underlying factors that can improve both manufacturing processes and specifically wind generators. The use of life cycle inventory techniques has provided a uniform framework to understand and compare the full range of environmental improvement in manufacturing, hence the concept of green manufacturing. In this project, the focus is on 1. the manufacturing steps that transform materials and chemicals into functioning products 2. the supply chain and end-of-life influences of materials and chemicals used in industry Results have been applied to wind generators, but also impact the larger U.S. product manufacturing base. For chemicals and materials, this project has provided a standard format for each lci that contains an overview and description, a process flow diagram, detailed mass balances, detailed energy of unit processes, and an executive summary. This is suitable for integration into other life cycle databases (such as that at NREL), so that broad use can be achieved. The use of representative processes allows unrestricted use of project results. With the framework refined in this project, information gathering was initiated for chemicals and materials in wind generation. Since manufacturing is one of the most significant parts of the environmental domain for wind generation improvement, this project research has developed a fundamental approach. The emphasis was place on individual unit processes as an organizing framework to understand the life cycle of manufactured products. The rearrangement of unit processes provides an efficient and versatile means of understanding improved manufactured products such as wind generators. The taxonomy and structure of unit process lci were developed in this project. A series of ten unit process lci were developed to sample the major segments of the manufacturing unit process taxonomy. Technical and economic effectiveness has been a focus of the project research in Task three. The use of repeatable modules for the organization of information on environmental improvement has a long term impact. The information developed can be used and reused in a variety of manufacturing plants and for a range of wind generator sizes and designs. Such a modular approach will lower the cost of life cycle analysis, that is often asked questions of carbon footprint, environmental impact, and sustainability. The use of a website for dissemination, linked to NREL, adds to the economic benefit as more users have access to the lci information. Benefit to the public has been achieved by a well-attended WSU conference, as well as presentations for the Kansas Wind Energy Commission. Attendees represented public interests, land owners, wind farm developers, those interested in green jobs, and industry. Another benefit to the public is the start of information flow from manufacturers that can inform individuals about products.

Janet M Twomey, PhD

2010-04-30

186

Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 3: Energy conversion subsystems and components. Part 1: Bottoming cycles and materials of construction  

NASA Technical Reports Server (NTRS)

Energy conversion subsystems and components were evaluated in terms of advanced energy conversion systems. Results of the bottoming cycles and materials of construction studies are presented and discussed.

Shah, R. P.; Solomon, H. D.

1976-01-01

187

Material and energy recovery in integrated waste management systems. An evaluation based on life cycle assessment  

SciTech Connect

This paper reports the environmental results, integrated with those arising from mass and energy balances, of a research project on the comparative analysis of strategies for material and energy recovery from waste, funded by the Italian Ministry of Education, University and Research. The project, involving the cooperation of five University research groups, was devoted to the optimisation of material and energy recovery activities within integrated municipal solid waste (MSW) management systems. Four scenarios of separate collection (overall value of 35%, 50% without the collection of food waste, 50% including the collection of food waste, 65%) were defined for the implementation of energetic, environmental and economic balances. Two sizes of integrated MSW management system (IWMS) were considered: a metropolitan area, with a gross MSW production of 750,000 t/year and an average province, with a gross MSW production of 150,000 t/year. The environmental analysis was conducted using Life Cycle Assessment methodology (LCA), for both material and energy recovery activities. In order to avoid allocation we have used the technique of the expansion of the system boundaries. This means taking into consideration the impact on the environment related to the waste management activities in comparison with the avoided impacts related to the saving of raw materials and primary energy. Under the hypotheses of the study, both for the large and for the small IWMS, the energetic and environmental benefits are higher than the energetic and environmental impacts for all the scenarios analysed in terms of all the indicators considered: the scenario with 50% separate collection in a drop-off scheme excluding food waste shows the most promising perspectives, mainly arising from the highest collection (and recycling) of all the packaging materials, which is the activity giving the biggest energetic and environmental benefits. Main conclusions of the study in the general field of the assessment of the environmental performance of any integrated waste management scheme address the importance of properly defining, beyond the design value assumed for the separate collection as a whole, also the yields of each material recovered; particular significance is finally related to the amount of residues deriving from material recovery activities, resulting on average in the order of 20% of the collected materials.

Giugliano, Michele; Cernuschi, Stefano [Politecnico di Milano - DIIAR, Environmental Section, P.zza Leonardo da Vinci, 32, 20133 Milano (Italy); Grosso, Mario, E-mail: mario.grosso@polimi.it [Politecnico di Milano - DIIAR, Environmental Section, P.zza Leonardo da Vinci, 32, 20133 Milano (Italy); Rigamonti, Lucia [Politecnico di Milano - DIIAR, Environmental Section, P.zza Leonardo da Vinci, 32, 20133 Milano (Italy)

2011-09-15

188

A System Dynamics Study of Carbon Cycling and Electricity Generation from Energy Crops  

E-print Network

1 A System Dynamics Study of Carbon Cycling and Electricity Generation from Energy Crops Hilary. This paper describes a system dynamics model of the carbon impacts from a dedicated energy crop. The work relies on another carbon accounting model, GORCAM, which uses spreadsheet modeling to investigate various

Ford, Andrew

189

Life-cycle greenhouse gas emissions and energy balances of sugarcane ethanol production in Mexico  

Microsoft Academic Search

The purpose of this work was to estimate GHG emissions and energy balances for the future expansion of sugarcane ethanol fuel production in Mexico with one current and four possible future modalities. We used the life cycle methodology that is recommended by the European Renewable Energy Directive (RED), which distinguished the following five system phases: direct Land Use Change (LUC);

Carlos A. García; Alfredo Fuentes; Anna Hennecke; Enrique Riegelhaupt; Fabio Manzini; Omar Masera

2011-01-01

190

Analysis of a Combined Cycle Recovering Pressure Energy of Natural Gas  

Microsoft Academic Search

With the development of economy and the pressure of environment pollution, natural gas industry have been developing as fast as well in recent years in China. Because of the unbalance distribution of natural gas resources in China, transportation pipelines have been developing quickly. There is huge pressure energy stored in the pipeline networks. A gas-steam combined cycle recovering pressure energy

Zhikun Wang; Zheng Zhang

2009-01-01

191

Unconventional working fluids in organic Rankine-cycles for waste energy recovery systems  

Microsoft Academic Search

This paper investigates the thermodynamic and physical properties of some unconventional fluids for use in organic Rankine-cycles supplied by waste energy sources. Energy requirement and recovery system performances are analyzed using realistic design operating conditions. Thermodynamic efficiencies and other useful results have been calculated by varying some recovery system operating parameters at various reference temperatures. With reference to proposed application,

V. Maizza; A. Maizza

2001-01-01

192

Potential Energy Savings from Optimized Schedule and Economizer Cycles in the Moody Library at UTMB  

E-print Network

by $27,700 for chilled water and $18,800 for steam. The total potential savings is $46,500/yr, which is 24% of the annual building energy cost, or 29% of the chilled water and steam energy costs. Table 5 shows that the economizer cycle can reduce...

Liu, M.; Athar, A.; Reddy, T. A.; Claridge, D. E.; Haberl, J. S.

1993-01-01

193

Red waters of Myrionecta rubra are biogeochemical hotspots for the Columbia River estuary with impacts on primary\\/secondary productions and nutrient cycles  

Microsoft Academic Search

The localized impact of blooms of the mixotrophic ciliate Myrionecta rubra in the Columbia River estuary during 2007-2010 was evaluated with biogeochemical, light microscopy, physiological and molecular data. M. rubra affected surrounding estuarine nutrient cycles, as indicated by high and low concentrations of organic nutrients and inorganic nitrogen, respectively, associated with red waters. M. rubra blooms also altered the energy

Lydie Herfort; Tawnya D. Peterson; Fredrick G. Prahl; Lee Ann McCue; Joe A. Needoba; Byron C. Crump; G. Curtis Roegner; Victoria Campbell; Peter A. Zuber

2012-01-01

194

High-energy sub-cycle optical waveform synthesizer  

E-print Network

Over the last decade, the control of atomic-scale electronic motion by optical fields strong enough to mitigate the atomic Coulomb potential, has broken tremendous new ground with the advent of phase controlled high-energy ...

Huang, Shu-Wei, Ph. D. Massachusetts Institute of Technology

2012-01-01

195

Energy Storage: Breakthrough in Battery Technologies (Carbon Cycle 2.0)  

SciTech Connect

Nitash Balsara speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 2, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

Balsara, Nitash

2010-02-04

196

Comparative energy and exergy analysis of R744, R404A and R290 refrigeration cycles  

Microsoft Academic Search

A detailed energy and exergy analysis of the low global warming potential refrigerants R744 and R290 was preformed and compared against the commercial refrigerant R404A in a single-stage vapour compression cycle and R744 in a two-stage vapour compression cycle with an internal heat exchanger. Copyright The Author 2009. Published by Oxford University Press. All rights reserved. For Permissions, please email:

J. A. Shilliday; S. A. Tassou; N. Shilliday

2009-01-01

197

Energy Storage: Breakthrough in Battery Technologies (Carbon Cycle 2.0)  

ScienceCinema

Nitash Balsara speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 2, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

Balsara, Nitash

2011-06-03

198

Cycle Evaluations of Reversible Chemical Reactions for Solar Thermochemical Energy Storage in Support of Concentrating Solar Power Generation Systems  

SciTech Connect

The production and storage of thermochemical energy is a possible route to increase capacity factors and reduce the Levelized Cost of Electricity from concentrated solar power generation systems. In this paper, we present the results of cycle evaluations for various thermochemical cycles, including a well-documented ammonia closed-cycle along with open- and closed-cycle versions of hydrocarbon chemical reactions. Among the available reversible hydrocarbon chemical reactions, catalytic reforming-methanation cycles are considered; specifically, various methane-steam reforming cycles are compared to the ammonia cycle. In some cases, the production of an intermediate chemical, methanol, is also included with some benefit being realized. The best case, based on overall power generation efficiency and overall plant capacity factor, was found to be an open cycle including methane-steam reforming, using concentrated solar energy to increase the chemical energy content of the reacting stream, followed by combustion to generate heat for the heat engine.

Krishnan, Shankar; Palo, Daniel R.; Wegeng, Robert S.

2010-07-25

199

Life Cycle Assessment for Energy Payback of Spherical Tokamak Reactors  

NASA Astrophysics Data System (ADS)

The energy payback ratio (EPR) is the index evaluating how a power plant produces the higher output energy effectively from the lower input energy. We used the system code and evaluated the EPRs of three reactor models; spherical tokamak (NC-ST), low aspect ratio tokamak reactor (LATR), and standard tokamak reactor (TR). The NC-ST and LATR systems have no center solenoid at the inboard side of plasma. In the case of NC-ST, normal conducting coils (NC) are used for toroidal field system. In LATR and TR superconducting coils (SC) are adopted. After we studied the relationship between the EPR of each fusion reactor and the aspect ratio in the range from 1.2 to 4.0, we evaluated the EPR of three typical models; ARIES-ST like, VECTOR like, and ARIES-RS like. The input parameters of aspect ratio, elongation, and normalized beta are as same as those of each original reactor. It was found that the EPR of LATR is the highest. Since LATR has no power loss due to ohmic-heating of normal conducting coils, the input energy of construction, operation and replacement is the lowest.

Ban, Kanae; Yamazaki, Kozo; Arimoto, Hideki; Oishi, Tetsutarou; Shoji, Tatsuo

200

The potential of solar energy use in desiccant cooling cycles  

Microsoft Academic Search

The use of heat produced by solar thermal collectors is an interesting option for thermal driven air conditioning processes. A thermal driven cooling technique which fits well to non-tracking solar collectors is the desiccant cooling technique. Recently several projects have been carried out which focus on the connection of desiccant cooling systems with solar thermal energy for regeneration of the

H-M Henning; T Erpenbeck; C Hindenburg; I. S Santamaria

2001-01-01

201

Converting chemical energy into electricity through a functionally cooperating device with diving-surfacing cycles.  

PubMed

A smart device that can dive or surface in aqueous medium has been developed by combining a pH-responsive surface with acid-responsive magnesium. The diving-surfacing cycles can be used to convert chemical energy into electricity. During the diving-surfacing motion, the smart device cuts magnetic flux lines and produces a current, demonstrating that motional energy can be realized by consuming chemical energy of magnesium, thus producing electricity. PMID:25146589

Song, Mengmeng; Cheng, Mengjiao; Ju, Guannan; Zhang, Yajun; Shi, Feng

2014-11-01

202

Assessment of energy performance in the life-cycle of biogas production  

Microsoft Academic Search

Energy balances are analysed from a life-cycle perspective for biogas systems based on 8 different raw materials. The analysis is based on published data and relates to Swedish conditions. The results show that the energy input into biogas systems (i.e. large-scale biogas plants) overall corresponds to 20–40% (on average approximately 30%) of the energy content in the biogas produced. The

Maria Berglund; Pål Börjesson

2006-01-01

203

An Improved Methodology to Estimate Terrestrial Net Primary Productivity by Integrating MODIS-LAI to Ecosystem Model SimCYCLE  

Microsoft Academic Search

Net Primary Productivity (NPP) is the difference between total photosynthesis and total plant respiration in an ecosystem. Estimating terrestrial NPP accurately is important as world's forest plays a vital role in the global carbon budget and overall environmental sustainability. Existing ecosystem models synthesize disparate time\\/space data into single coherent analysis of terrestrial carbon fluxes by incorporating known parameterizations of different

P. J. Baruah; A. Ito; Y. Yasuoka; D. Dye; A. Sumi

2007-01-01

204

Body Parts, the Water Cycle, Plants, and Dolphins: Adventures in Primary-Grade Whole-Class Composing  

ERIC Educational Resources Information Center

This article describes the author's personal experiences leading primary grades in whole-class composing. Together they created songs inspired by topics the students were exploring in their homeroom classes. The author systematically describes the songwriting process they employed, identifying specific challenges encountered along the way. The…

Bolden, Benjamin

2009-01-01

205

Impact of agricultural landscape structure on energy flow and water cycling  

Microsoft Academic Search

In long term studies the following climatological characteristics were measured or calculated: air and soil temperature, sunshine, wind speed, vapor pressure, saturation deficit, precipitation, humidity, incoming and reflected solar energy, energy emitted by active surfaces and primary production. Taking into account the relationships between climatological characteristics, the growth stages of vegetation, and relations between heat balance components, the fluxes of

L. Ryszkowski; A. K?dziora

1987-01-01

206

Life cycle assessment of biofuels: energy and greenhouse gas balances.  

PubMed

The promotion of biofuels as energy for transportation in the industrialized countries is mainly driven by the perspective of oil depletion, the concerns about energy security and global warming. However due to sustainability constraints, biofuels will replace only 10 to 15% of fossil liquid fuels in the transport sector. Several governments have defined a minimum target of GHG emissions reduction for those biofuels that will be eligible to public incentives, for example a 35% emissions reduction in case of biofuels in Members States of the European Union. This article points out the significant biases in estimating GHG balances of biofuels stemming from modelling choices about system definition and boundaries, functional unit, reference systems and allocation methods. The extent to which these choices influence the results is investigated. After performing a comparison and constructive criticism of various modelling choices, the LCA of wheat-to-bioethanol is used as an illustrative case where bioethanol is blended with gasoline at various percentages (E5, E10 and E85). The performance of these substitution options is evaluated as well. The results show a large difference in the reduction of the GHG emissions with a high sensitivity to the following factors: the method used to allocate the impacts between the co-products, the type of reference systems, the choice of the functional unit and the type of blend. The authors come out with some recommendations for basing the estimation of energy and GHG balances of biofuels on principles such as transparency, consistency and accuracy. PMID:19553106

Gnansounou, E; Dauriat, A; Villegas, J; Panichelli, L

2009-11-01

207

Thermal energy storage for an integrated coal gasification combined-cycle power plant  

SciTech Connect

This study investigates the use of molten nitrate salt thermal energy storage in an integrated gasification combined-cycle power plant allowing the facility to economically provide peak- and intermediate-load electric power. The results of the study show that an integrated gasification combined-cycle power plant with thermal energy storage can reduce the cost of coal-fired peak- or intermediate-load electric power by between 5% and 20% depending on the plants operating schedule. The use of direct-contact salt heating can further improve the economic attractiveness of the concept. 12 refs., 1 fig., 5 tabs.

Drost, K.; Antoniak, Z.; Brown, D.; Somasundaram, S.

1991-10-01

208

Life cycle assessment of an intensive sewage treatment plant in Barcelona (Spain) with focus on energy aspects.  

PubMed

Life Cycle Assessment was used to evaluate environmental impacts associated to a full-scale wastewater treatment plant (WWTP) in Barcelona Metropolitan Area, with a treatment capacity of 2 million population equivalent, focussing on energy aspects and resources consumption. The wastewater line includes conventional pre-treatment, primary settler, activated sludge with nitrogen removal, and tertiary treatment; and the sludge line consists of thickening, anaerobic digestion, cogeneration, dewatering and thermal drying. Real site data were preferably included in the inventory. Environmental impacts of the resulting impact categories were determined by the CLM 2 baseline method. According to the results, the combustion of natural gas in the cogeneration engine is responsible for the main impact on Climate Change and Depletion of Abiotic Resources, while the combustion of biogas in the cogeneration unit accounts for a minor part. The results suggest that the environmental performance of the WWTP would be enhanced by increasing biogas production through improved anaerobic digestion of sewage sludge. PMID:22097019

Bravo, L; Ferrer, I

2011-01-01

209

Wave properties of light Light is energy whose wavelength is the distance traveled in order to complete one cycle.  

E-print Network

Wave properties of light Light is energy whose wavelength is the distance traveled in order to complete one cycle. The frequency of light refers to the number of cycles in one second. Low-energy light has a long wavelength and a low frequency. High-energy light has a short wavelength and a high

Zworski, Maciej

210

Chlorine as a primary radical: evaluation of methods to understand its role in initiation of oxidative cycles  

NASA Astrophysics Data System (ADS)

The role of chlorine atoms (Cl) in atmospheric oxidation has been traditionally thought to be limited to the marine boundary layer, where they are produced through heterogeneous reactions involving sea salt. However, recent observation of photolytic Cl precursors (ClNO2 and Cl2) formed from anthropogenic pollution has expanded the potential importance of Cl to include coastal and continental urban areas. Measurements of ClNO2 in Los Angeles during CalNex (California Nexus - Research at the Nexus of Air Quality and Climate Change) showed it to be an important primary (first generation) radical source. Evolution of ratios of volatile organic compounds (VOCs) has been proposed as a method to quantify Cl oxidation, but we find no evidence from this approach for a significant role of Cl oxidation in Los Angeles. We use a box model with the Master Chemical Mechanism (MCM v3.2) chemistry scheme, constrained by observations in Los Angeles, to examine the Cl sensitivity of commonly used VOC ratios as a function of NOx and secondary radical production. Model results indicate VOC tracer ratios could not detect the influence of Cl unless the ratio of [OH] to [Cl] was less than 200 for at least a day. However, the model results also show that secondary (second generation) OH production resulting from Cl oxidation of VOCs is strongly influenced by NOx, and that this effect obscures the importance of Cl as a primary oxidant. Calculated concentrations of Cl showed a maximum in mid-morning due to a photolytic source from ClNO2 and loss primarily to reactions with VOCs. The [OH] to [Cl] ratio was below 200 for approximately 3 h in the morning, but Cl oxidation was not evident from the measured ratios of VOCs. Instead, model simulations show that secondary OH production causes VOC ratio evolution to follow that expected for OH oxidation, despite the significant input of primary Cl from ClNO2 photolysis in the morning. Even though OH is by far the dominant oxidant in Los Angeles, Cl atoms do play an important role in photochemistry there, constituting 9% of the primary radical source. Furthermore, Cl-VOC reactivity differs from that of OH, being more than an order of magnitude larger and dominated by VOCs, such as alkanes, that are less reactive toward OH. Primary Cl is also slightly more effective as a radical source than primary OH due to its greater propensity to initiate radical propagation chains via VOC reactions relative to chain termination via reaction with nitrogen oxides.

Young, C. J.; Washenfelder, R. A.; Edwards, P. M.; Parrish, D. D.; Gilman, J. B.; Kuster, W. C.; Mielke, L. H.; Osthoff, H. D.; Tsai, C.; Pikelnaya, O.; Stutz, J.; Veres, P. R.; Roberts, J. M.; Griffith, S.; Dusanter, S.; Stevens, P. S.; Flynn, J.; Grossberg, N.; Lefer, B.; Holloway, J. S.; Peischl, J.; Ryerson, T. B.; Atlas, E. L.; Blake, D. R.; Brown, S. S.

2014-04-01

211

Life-cycle energy efficiency and environmental impacts of bioethanol production from sweet potato.  

PubMed

Life-cycle assessment (LCA) was used to evaluate the energy efficiency and environmental impacts of sweet potato-based bioethanol production. The scope covered all stages in the life cycle of bioethanol production, including the cultivation and treatment, transport, as well as bioethanol conversion of sweet potato. Results show that the net energy ratio of sweet potato-based bioethanol is 1.48 and the net energy gain is 6.55 MJ/L. Eutrophication is identified as the most significant environmental impact category, followed by acidification, global warming, human toxicity, and photochemical oxidation. Sensitivity analysis reveals that steam consumption during bioethanol conversion exerts the most effect on the results, followed by sweet potato yields and fertilizers input. It is suggested that substituting coal with cleaner energy for steam generation in bioethanol conversion stage and promotion of better management practices in sweet potato cultivation stage could lead to a significant improvement of energy and environmental performance. PMID:23434804

Wang, Mingxin; Shi, Yu; Xia, Xunfeng; Li, Dinglong; Chen, Qun

2013-04-01

212

Climate sensitivity with a seasonal cycle energy balance model  

NASA Technical Reports Server (NTRS)

The sensitivity of climate which may have a local maximum as the ice cap passes through a midlatitude region where the atmosphere's transport efficiency varies strongly with latitude is examined. This behavior, found in a two level primitive equations climate model forced with annual mean insolation, was reproduced in an energy balance model (EBM) by making the diffusion coefficient a function of latitude. The two level seasonally varying EBM was applied and the global mean surface temperature vs. solar constant for this model are shown and two regions of enhanced sensitivity appear. The snowcover distributions around the year for three cases are shown.

Suarez, M. J.

1984-01-01

213

ENVIRONMENTAL CONSIDERATIONS OF SELECTED ENERGY CONSERVING MANUFACTURING PROCESS OPTIONS: VOLUME XIV. PRIMARY COPPER INDUSTRY REPORT  

EPA Science Inventory

This study assesses the likelihood of new process technology and new practices being introduced by energy intensive industries and explores the environmental impacts of such changes. Volume 14 deals with the primary copper industry and examines six alternatives: (1) Outokumpu fla...

214

Studies of low-energy Galactic cosmic-ray composition at 22 AU. I - Secondary/primary ratios  

NASA Technical Reports Server (NTRS)

Data from the High Energy Telescope of the CRS experiment on Voyager 2 have been used to measure the intensity, spectra, and elemental abundances of Galactic cosmic rays from Be to Ni at about 100 MeV/n. The charge resolution of this telescope varies from sigma = 0.034 for oxygen to sigma = 0.11 for iron. The solar modulation deceleration parameter Phi relevant for these data is estimated to be around 300 MV (Phi = 150 MeV/n for particles with A/Z = 2), an unprecedently low level for such measurements. This low modulation parameter is a result of the measurements being made in the outer heliosphere at a heliocentric distance of 22 AU, and centered on the solar minimum period of cycle 21. The results on secondary/primary ratios are used to test the Leaky-Box model of cosmic ray propagation, using the most recent cross sections data in hydrogen and helium, and taking into account the effects of the ionized fraction of the interstellar medium. It is found that all the secondary/primary ratios up to P/S are completely consistent with an exponential pathlength distribution (PLD). This PLD shape also accounts for the Sc-V/Fe ratio.

Ferrando, P.; Lal, N.; Mcdonald, F. B.; Webber, W. R.

1991-01-01

215

ENERGY SPECTRA OF PRIMARY AND SECONDARY COSMIC-RAY NUCLEI MEASURED WITH TRACER  

SciTech Connect

The Transition Radiation Array for Cosmic Energetic Radiation (TRACER) cosmic-ray detector, first flown on long-duration balloon (LDB) in 2003 for observations of the major primary cosmic-ray nuclei from oxygen (Z = 8) to iron (Z = 26), has been upgraded to also measure the energies of the lighter nuclei, including the secondary species boron (Z = 5). The instrument was used in another LDB flight in 2006. The properties and performance of the modified detector system are described, and the analysis of the data from the 2006 flight is discussed. The energy spectra of the primary nuclei carbon (Z = 6), oxygen, and iron over the range from 1 GeV amu{sup -1} to 2 TeV amu{sup -1} are reported. The data for oxygen and iron are found to be in good agreement with the results of the previous TRACER flight. The measurement of the energy spectrum of boron also extends into the TeV amu{sup -1} region. The relative abundances of the primary nuclei, such as carbon, oxygen, and iron, above {approx}10 GeV amu{sup -1} are independent of energy, while the boron abundance, i.e., the B/C abundance ratio, decreases with energy as expected. However, there is an indication that the previously reported E {sup -0.6} dependence of the B/C ratio does not continue to the highest energies.

Obermeier, A.; Ave, M.; Boyle, P.; Hoeppner, Ch.; Mueller, D. [Enrico Fermi Institute, University of Chicago, Chicago, IL 60637 (United States); Hoerandel, J., E-mail: a.obermeier@astro.ru.nl [Department of Astrophysics, Radboud University Nijmegen, 6525 HP Nijmegen (Netherlands)

2011-11-20

216

Implications of incorporating N cycling and N limitations on primary production in an individual-based dynamic vegetation model  

NASA Astrophysics Data System (ADS)

The LPJ-GUESS dynamic vegetation model uniquely combines an individual- and patch-based representation of vegetation dynamics with ecosystem biogeochemical cycling from regional to global scales. We present an updated version that includes plant and soil N dynamics, analysing the implications of accounting for C-N interactions on predictions and performance of the model. Stand structural dynamics and allometric scaling of tree growth suggested by global databases of forest stand structure and development were well-reproduced by the model in comparison to an earlier multi-model study. Accounting for N cycle dynamics improved the goodness-of-fit for broadleaved forests. N limitation associated with low N mineralisation rates reduces productivity of cold-climate and dry-climate ecosystems relative to mesic temperate and tropical ecosystems. In a model experiment emulating free-air CO2 enrichment (FACE) treatment for forests globally, N-limitation associated with low N mineralisation rates of colder soils reduces CO2-enhancement of NPP for boreal forests, while some temperate and tropical forests exhibit increased NPP enhancement. Under a business-as-usual future climate and emissions scenario, ecosystem C storage globally was projected to increase by c. 10%; additional N requirements to match this increasing ecosystem C were within the high N supply limit estimated on stoichiometric grounds in an earlier study. Our results highlight the importance of accounting for C-N interactions not only in studies of global terrestrial C cycling, but to understand underlying mechanisms on local scales and in different regional contexts.

Smith, B.; Wårlind, D.; Arneth, A.; Hickler, T.; Leadley, P.; Siltberg, J.; Zaehle, S.

2013-11-01

217

Thermodynamic analysis of five compressed-air energy-storage cycles  

NASA Astrophysics Data System (ADS)

One important aspect of the compressed air energy storage (CAES) program is the evaluation of alternative CAES plant designs. The thermodynamic performance of the various configurations is critical to the successful demonstration of CAES as an economically feasible energy storage option. A computer code, the compressed air energy storage cycle analysis program (CAESCAP), was developed. This code was designed to calculate overall thermodynamic performance of proposed CAES system configurations. The results of applying this code to the analysis of five CAES plant designs are presented. The designs analyzed are conventional CAES; adiabatic CAES; hybrid CAES; pressurized fluidized bed CAES; and direct coupled steam CAES. Data were used to diagram the availability and energy flow for each of the five cycles. The resulting diagrams graphically illustrate the overall thermodynamic performance inherent in each plant configuration, and enable a more accurate and complete understanding of each design.

Fort, J. A.

1983-03-01

218

The Energy-Cycle Analysis of the Interactions Between Shallow and Deep Atmospheric Convection  

E-print Network

The Energy-Cycle Analysis of the Interactions Between Shallow and Deep Atmospheric Convection´et´eo-France and CNRS, 31057 Toulouse Cedex, France Abstract Interactions between different convection modes can investigates this system by taking a limit of two modes: shallow and deep convection. Shallow convection

Plant, Robert

219

Gas desorption from seawater in open-cycle ocean thermal energy conversion barometric upcomers  

Microsoft Academic Search

Gas desorption from warm and cold seawater under open-cycle ocean thermal energy conversion (OC-OTEC) conditions is addressed in this paper. The desorption process of dissolved Oâ, Nâ, and COâ in the barometric upcomers of an OTEC plant is simulated mathematically. The model considers the growth of bubbles originating in the ocean and bubbles formed in the upcomers. Bubble growth is

S. M. Ghiaasiaan; A. T. Wassel; A. A. Pesaran

1990-01-01

220

Assessing total and renewable energy in Brazilian automotive fuels. A life cycle inventory (LCI) approach  

Microsoft Academic Search

This article uses a first approach LCI procedure to evaluate total and renewable energy and CO2 emissions in Brazilian automotive fuels life cycle (LC). The LC model is structured and modular, capable of being successively refined if necessary. The procedure is applied to passenger car use in urban traffic, comparing three fuels used in Brazil (gasoline with 25% ethanol, pure

Márcio de Almeida D’Agosto; Suzana Kahn Ribeiro

2009-01-01

221

November 2009Vol. 19, No. 4 Global Energy and Water Cycle Experiment  

E-print Network

International GEWEX Science Conference and Joint GEWEX/iLEAPS Sessions Melbourne, Australia, 24­28 August 2009 and Water Cycle Meeting/Workshop Reports: - GEWEX Atmospheric Boundary Layer Study (GABLS) Workshop - Third GEWEX/WCRP Calendar 2 3 4 4 5 6 7 8 9 11 13 15 17 18 19 20 #12;2 November 2009 Global Energy and Water

Ribes, Aurélien

222

Use of solar energy for direct and two-step water decomposition cycles  

Microsoft Academic Search

The feasibility of using concentrated solar energy at high temperatures to decompose water is experimentally demonstrated. Preliminary studies show that direct decomposition of water at 2000-2500 C is possible and that the main development should be directed toward reactor design and the separation of product gases. On the other hand, it is shown that two-step thermochemical cycles for hydrogen production

E. Bilgen; M. Ducarroir; M. Foex; F. Sibieude; F. Trombe

1977-01-01

223

The Mackenzie GEWEX Study: The Water and Energy Cycles of a Major North American River Basin  

Microsoft Academic Search

The Mackenzie River is the largest North American source of freshwater for the Arctic Ocean. This basin is subjected to wide fluctuations in its climate and it is currently experiencing a pronounced warming trend. As a major Canadian contribution to the Global Energy and Water Cycle Experiment (GEWEX), the Mackenzie GEWEX Study (MAGS) is focusing on understanding and modeling the

R. E. Stewart; R. W. Crawford; H. G. Leighton; P. Marsh; G. S. Strong; G. W. K. Moore; H. Ritchie; W. R. Rouse; E. D. Soulis; B. Kochtubajda

1998-01-01

224

The Global Energy and Water Cycle Experiment: Applying Planetary Science to Global and Regional Water Issues  

Microsoft Academic Search

The Global Energy and Water Cycle Experiment (GEWEX) was initiated in 1988 under the auspices of the World Climate Research Programme. The first phase of GEWEX has now come to a successful conclusion and work is progressing on the Phase II objectives and goals. During Phase I, efforts were directed at the development of data bases at global and regional

R. G. Lawford

2004-01-01

225

Standard mechanical energy analyses do not correlate with muscle work in cycling  

Microsoft Academic Search

The goal of this study was to assess the utility of experimental methods to quantify mechanical energy expenditure (MEE) in human movement. To achieve this goal, a theoretical model of steady-state cycling driven by individual muscle actuators was used to produce two distinct pedal simulations. The simulations yielded the same pedaling rate and power output, but one reduced the MEE

R. R. Neptune; A. J. van den Bogert

1998-01-01

226

Life Cycle Energy and GHG Analysis of Hydroelectric Power Development in India  

Microsoft Academic Search

This study presents the results of a life cycle assessment of energy usage and greenhouse gas (GHG) emissions from electricity generation by small hydroelectric projects for understanding the characteristics of these systems from the perspective of global warming. Two types of hydropower schemes, viz. canal-based and dam-toe schemes, have been analyzed. The energy pay-back time for canal-based scheme is found

Varun; Ravi Prakash; I. K. Bhat

2010-01-01

227

Solar thermal power cycle with integration of methanol decomposition and middle-temperature solar thermal energy  

Microsoft Academic Search

In this paper, we have proposed a new solar thermal power cycle which integrates methanol decomposition and middle-temperature solar thermal energy, and investigated its features based on the principle of the cascade utilization of chemical exergy. Also, the methanol decomposition with a catalyst was experimentally studied at temperatures of 150–300°C and under atmospheric pressure. The chemical energy released by methanol

Hui Hong; Hongguang Jin; Jun Ji; Zhifeng Wang; Ruixian Cai

2005-01-01

228

Second Law Analysis for Process and Energy Engineering: Use in a Steam/Power Cycle  

E-print Network

Second Law Analysis for Process and Energy Engineering: Use in a Steam/Power Cycle I Dominick Sama Richard Gaggloli Daniel Finkenthal William Cooley Unlverlsty of Lowell Introduction The objective of this paper Is to demonstrate how the use... playa part in the foregoing case study. Acknowledgement ThIs wQrk was supported In part by the Center for Producl!vlty Enhancement, University of Lowell. References ASME Vol. AES I, Analysis of Energy Systems: Design! and Operation, 1985 (A...

Sama, D.; Sanhong, Q.

229

Comparative energy life-cycle analyses of microalgal biomass production in open ponds and photobioreactors  

Microsoft Academic Search

An analysis of the energy life-cycle for production of biomass using the oil-rich microalgae Nannochloropsis sp. was performed, which included both raceway ponds, tubular and flat-plate photobioreactors for algal cultivation. The net energy ratio (NER) for each process was calculated. The results showed that the use of horizontal tubular photobioreactors (PBRs) is not economically feasible ([NER]<1) and that the estimated

Orlando Jorquera; Asher Kiperstok; Emerson A. Sales; Marcelo Embiruçu; Maria L. Ghirardi

2010-01-01

230

Effects of Fuel Ethanol Use on Fuel-Cycle Energy and Greenhouse Gas Emissions  

Microsoft Academic Search

We estimated the effects on per-vehicle-mile fuel-cycle petroleum use, greenhouse gas (GHG) emissions, and energy use of using ethanol blended with gasoline in a mid-size passenger car, compared with the effects of using gasoline in the same car. Our analysis includes petroleum use, energy use, and emissions associated with chemicals manufacturing, farming of corn and biomass, ethanol production, and ethanol

C. Saricks; D. Santini; M. Wang

1999-01-01

231

Modeling Energy Recovery Using Thermoelectric Conversion Integrated with an Organic Rankine Bottoming Cycle  

SciTech Connect

Hot engine exhaust represents a resource that is often rejected to the environment without further utilization. This resource is most prevalent in the transportation sector, but stationary engine-generator systems also typically do not utilize this resource. Engine exhaust is a source of high grade thermal energy that can potentially be utilized by various approaches to produce electricity or to drive heating and cooling systems. This paper describes a model system that employs thermoelectric conversion as a topping cycle integrated with an organic Rankine bottoming cycle for waste heat utilization. This approach is being developed to fully utilize the thermal energy contained in hot exhaust streams. The model is composed of a high temperature heat exchanger which extracts thermal energy for driving the thermoelectric conversion elements. However, substantial sensible heat remains in the exhaust stream after emerging from the heat exchanger. The model incorporates a closely integrated bottoming cycle to utilize this remaining thermal energy in the exhaust stream. The model has many interacting parameters that define combined system quantities such as overall output power, efficiency, and total energy utilization factors. In addition, the model identifies a maximum power operating point for the system. That is, the model can identify the optimal amount of heat to remove from the exhaust flow to run through the thermoelectric elements. Removing too much or too little heat from the exhaust stream in this stage will reduce overall cycle performance. The model has been developed such that heat exchanger UAh values, thermal resistances, ZT values, and multiple thermoelectric elements can be investigated in the context of system operation. The model also has the ability to simultaneously determine the effect of each cycle design parameter on the performance of the overall system, thus giving the ability to utilize as much waste heat as possible. Key analysis results are presented showing the impact of critical design parameters on power output, system performance and inter-relationships between design parameters in governing performance.

Miller, Erik W.; Hendricks, Terry J.; Peterson, Richard B.

2009-07-01

232

Scatter correction using a primary modulator for dual energy digital radiography: A Monte Carlo simulation study  

NASA Astrophysics Data System (ADS)

In conventional digital radiography (DR) using a dual energy subtraction technique, a significant fraction of the detected photons are scattered within the body, making up the scatter component. Scattered radiation can significantly deteriorate image quality in diagnostic X-ray imaging systems. Various methods of scatter correction, including both measurement- and non-measurement-based methods, have been proposed in the past. Both methods can reduce scatter artifacts in images. However, non-measurement-based methods require a homogeneous object and have insufficient scatter component correction. Therefore, we employed a measurement-based method to correct for the scatter component of inhomogeneous objects from dual energy DR (DEDR) images. We performed a simulation study using a Monte Carlo simulation with a primary modulator, which is a measurement-based method for the DEDR system. The primary modulator, which has a checkerboard pattern, was used to modulate the primary radiation. Cylindrical phantoms of variable size were used to quantify the imaging performance. For scatter estimates, we used discrete Fourier transform filtering, e.g., a Gaussian low-high pass filter with a cut-off frequency. The primary modulation method was evaluated using a cylindrical phantom in the DEDR system. The scatter components were accurately removed using a primary modulator. When the results acquired with scatter correction and without scatter correction were compared, the average contrast-to-noise ratio (CNR) with the correction was 1.35 times higher than that obtained without the correction, and the average root mean square error (RMSE) with the correction was 38.00% better than that without the correction. In the subtraction study, the average CNR with the correction was 2.04 (aluminum subtraction) and 1.38 (polymethyl methacrylate (PMMA) subtraction) times higher than that obtained without the correction. The analysis demonstrated the accuracy of the scatter correction and the improvement of image quality that could be obtained by using a primary modulator and showed the feasibility of introducing the primary modulation technique into dual energy subtraction. Therefore, we suggest that the scatter correction method with a primary modulator will be useful for use with the DEDR system.

Jo, Byung-Du; Lee, Young-Jin; Kim, Dae-Hong; Kim, Hee-Joung

2014-08-01

233

18 CFR 2.400 - Statement of interpretation of waste concerning natural gas as the primary energy source for...  

Code of Federal Regulations, 2011 CFR

...18 Conservation of Power and Water Resources 1 2011-04-01...concerning natural gas as the primary energy source for qualifying small power...400 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION,...

2011-04-01

234

18 CFR 2.400 - Statement of interpretation of waste concerning natural gas as the primary energy source for...  

Code of Federal Regulations, 2014 CFR

...18 Conservation of Power and Water Resources 1 2014-04-01...concerning natural gas as the primary energy source for qualifying small power...400 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION,...

2014-04-01

235

18 CFR 2.400 - Statement of interpretation of waste concerning natural gas as the primary energy source for...  

Code of Federal Regulations, 2013 CFR

...18 Conservation of Power and Water Resources 1 2013-04-01...concerning natural gas as the primary energy source for qualifying small power...400 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION,...

2013-04-01

236

18 CFR 2.400 - Statement of interpretation of waste concerning natural gas as the primary energy source for...  

Code of Federal Regulations, 2012 CFR

...18 Conservation of Power and Water Resources 1 2012-04-01...concerning natural gas as the primary energy source for qualifying small power...400 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION,...

2012-04-01

237

An Experimental Study on Thermal Energy Storage Based Reverse Cycle Defrosting Method Using Subcooling Energy of Refrigerant for Air Source Heat Pump: Characteristics of Thermal Energy Storage Operation  

Microsoft Academic Search

the introduction introduction of the the system of thermal energy storage torage (TES) based reverse cycle defrosting method using sub-cooling energy of refrigerant for air Source heat eat p pump (ASHP) is given firstly. And And then the the characteristic of TES TES using sub-cooling energy of refrigerant in in heating is experimentally researched. The results results show that that

Dong Jiankai; Qu Minglu; Jiang Yiqiang; Yao Yang; Deng Shiming; Wang Honglei

2011-01-01

238

Energy spectra of primary and secondary cosmic-ray nuclei measured with TRACER  

E-print Network

The TRACER cosmic-ray detector, first flown on long-duration balloon (LDB) in 2003 for observations of the major primary cosmic-ray nuclei from oxygen (Z=8) to iron (Z=26), has been upgraded to also measure the energies of the lighter nuclei, including the secondary species boron (Z=5). The instrument was used in another LDB flight in 2006. The properties and performance of the modified detector system are described, and the analysis of the data from the 2006 flight is discussed. The energy spectra of the primary nuclei carbon (Z=6), oxygen, and iron over the range from 1 GeV amu$^{-1}$ to 2 TeV amu$^{-1}$ are reported. The data for oxygen and iron are found to be in good agreement with the results of the previous TRACER flight. The measurement of the energy spectrum of boron also extends into the TeV amu$^{-1}$ region. The relative abundances of the primary nuclei, such as carbon, oxygen, and iron, above $\\sim10$ GeV amu$^{-1}$ are independent of energy, while the boron abundance, i.e. the B/C abundance rati...

Obermeier, A; Boyle, P; Höppner, Ch; Hörandel, J; Müller, D

2011-01-01

239

Vacuum thermal cycle life testing of high temperature thermal energy storage  

NASA Astrophysics Data System (ADS)

Three fluoride-eutectic mixtures having 1000 K melting points and heats of fusion above 750 kJ/kg have been tested by an experimental program investigating the corrosion compatibility of high temperature thermal energy storage (TES) salts with their Inconel-617 containers. Electron beam-welded TES capsules were placed in a furnace for continuous thermal cycle life testing; the capsules have successfully undergone 4000 hrs and 10,000 cycles of testing, thereby representing the longest TES corrosion compatibility data record. Careful processing and proper welding are the keys to a long-life TES system.

Ponnappan, Rengasamy; Beam, Jerry E.

240

Optimal energy-harvesting cycles for load-driven dielectric generators in plane strain  

E-print Network

The performances of energy harvesting generators based on dielectric elastomers are investigated. The configuration is of a thin dielectric film coated by stretchable electrodes at both sides. The film is first stretched, then charged and subsequently, afterwards it is released, and finally the charge is harvested at a higher electric potential. The amount of energy extracted by this cycle is bounded by the electric breakdown and the ultimate stretch ratio of the film as well as by structural instabilities due to loss of tension. To identify the optimal cycle that complies with these limits we formulate a constraint optimization problem and solve it with a dedicated solver for two typical classes of elastic dielectrics. As anticipated, we find that the performance of the generator depends critically on the ultimate stretch ratio of the film. However, more surprising is our finding of a universal limit on the dielectric strength of the film beyond which the optimal cycle is independent of this parameter. Thus, we reveal that, regardless of how large the dielectric strength of the material is, there is an upper bound on the amount of harvested energy that depends only on the ultimate stretch ratio. We conclude the work with detailed calculations of the optimal cycles for two commercially available elastic dielectrics.

R. Springhetti; E. Bortot; G. deBotton; M. Gei

2014-03-13

241

Impact of the menstrual cycle on determinants of energy balance: a putative role in weight loss attempts  

Microsoft Academic Search

Women's weight and body composition is significantly influenced by the female sex-steroid hormones. Levels of these hormones fluctuate in a defined manner throughout the menstrual cycle and interact to modulate energy homeostasis. This paper reviews the scientific literature on the relationship between hormonal changes across the menstrual cycle and components of energy balance, with the aim of clarifying whether this

L Davidsen; B Vistisen; A Astrup

2007-01-01

242

Functional unit, technological dynamics, and scaling properties for the life cycle energy of residences.  

PubMed

Prior LCA studies take the operational phase to include all energy use within a residence, implying a functional unit of all household activities, but then exclude related supply chains such as production of food, appliances, and household chemicals. We argue that bounding the functional unit to provision of a climate controlled space better focuses the LCA on the building, rather than activities that occur within a building. The second issue explored in this article is how technological change in the operational phase affects life cycle energy. Heating and cooling equipment is replaced at least several times over the lifetime of a residence; improved efficiency of newer equipment affects life cycle energy use. The third objective is to construct parametric models to describe LCA results for a family of related products. We explore these three issues through a case study of energy use of residences: one-story and two-story detached homes, 1,500-3,500 square feet in area, located in Phoenix, Arizona, built in 2002 and retired in 2051. With a restricted functional unit and accounting for technological progress, approximately 30% of a building's life cycle energy can be attributed to materials and construction, compared to 0.4-11% in previous studies. PMID:22192002

Frijia, Stephane; Guhathakurta, Subhrajit; Williams, Eric

2012-02-01

243

Energy conservation in the primary aluminum and chlor-alkali industries  

SciTech Connect

The primary aluminum and chlor-alkali industries together use nearly 13% of the electrical energy consumed by US industry. As part of its mission to promote energy conservation in basic US industries, the DOE surveys the present technological status of the major electrochemical industries and evaluates promising technological innovations that may lead to reduced energy requirements. This study provides technical and economic analyses in support of a government program of research and development in advanced electrolytic technology. This program is intended to supplement the development efforts directed toward energy savings by private industry. Sections II and III of this report cover aluminum and chlorine production processes only, since these two industries represent over 90% of the electrical energy requirements of all electrolytic industries in the United States. Section IV examines barriers to accelerated research and development by the electrolytic industries, and makes suggestions for government actions to overcome these barriers.

Not Available

1980-10-01

244

TYPES OF FLOODING IN AUSTRALIA Floods are part of the natural water cycle or a "Hydrologic Cycle". In this natural cycle, the energy of the sun causes  

E-print Network

TYPES OF FLOODING IN AUSTRALIA Floods are part of the natural water cycle or a "Hydrologic Cycle into the soil to later form groundwater flow. Floods happen when the capacity of the rivers is not enough quite regularly is called a floodplain. Floods are caused by prolonged or heavy rainfall. Cyclones bring

Greenslade, Diana

245

Shifting primary energy source and NOx emission location with plug-in hybrid vehicles  

Microsoft Academic Search

Plug-in hybrid vehicles (PHEVs) present an interesting technological opportunity for using non-fossil primary energy in light duty passenger vehicles, with the associated potential for reducing air pollutant and greenhouse gas emissions, to the extent that the electric power grid is fed by non-fossil sources. This perspective, accompanying the article by Thompson et al (2011) in this issue, will touch on

Deniz Karman

2011-01-01

246

National Survey of Energy Balance-related Care among Primary Care Physicians  

Cancer.gov

This survey, one of several physician surveys conducted by the Applied Research Program, is designed to obtain current, nationally representative data on primary care physicians' (PCPs') characteristics, knowledge, attitudes, and practices related to services for diet, physical activity, and weight control. The goal is to develop a national baseline on the use of energy balance risk assessment, counseling and referral services in physician practice and to identify the characteristics of physicians who routinely incorporate these activities in patient care.

247

The IEA Model of Short-Term Energy Security (MOSES): Primary Energy Sources and Secondary Fuels  

Microsoft Academic Search

Ensuring energy security has been at the centre of the IEA mission since its inception, following the oil crises of the early 1970s. While the security of oil supplies remains important, contemporary energy security policies must address all energy sources and cover a a comprehensive range of natural, economic and political risks that affect energy sources, infrastructures and services. In

Jessica Jewell

2011-01-01

248

High-energy half-cycle cutoffs in high harmonic and rescattered electron spectra using waveform-controlled few-cycle infrared pulses  

NASA Astrophysics Data System (ADS)

We developed a few-cycle waveform-controlled light source for infrared pulses at 1.6 ? m that is based on optical chirped-pulse amplification in Bi{{B}3}{{O}6} (BIBO) crystals pumped by Ti:sapphire lasers. Using this source, we observe soft x-ray high harmonics that extend up to a photon energy of ? 320 eV, as well as high-energy photoelectrons up to ? 1 keV. The spectra of the high harmonics and photoelectrons have clear signatures of half-cycle cutoffs that can be used to extract electronic and molecular dynamics on an attosecond time scale.

Geiseler, H.; Ishii, N.; Kaneshima, K.; Kitano, K.; Kanai, T.; Itatani, J.

2014-10-01

249

Total energy cycle assessment of electric and conventional vehicles: an energy and environmental analysis. Volume 1: technical report  

SciTech Connect

This report compares the energy use, oil use and emissions of electric vehicles (EVs) with those of conventional, gasoline-powered vehicles (CVs) over the total life cycle of the vehicles. The various stages included in the vehicles` life cycles include vehicle manufacture, fuel production, and vehicle operation. Disposal is not included. An inventory of the air emissions associated with each stage of the life cycle is estimated. Water pollutants and solid wastes are reported for individual processes, but no comprehensive inventory is developed. Volume I contains the major results, a discussion of the conceptual framework of the study, and summaries of the vehicle, utility, fuel production, and manufacturing analyses. It also contains summaries of comments provided by external peer reviewers and brief responses to these comments.

Cuenca, R.; Formento, J.; Gaines, L.; Marr, B.; Santini, D.; Wang, M. [Argonne National Lab., IL (United States); Adelman, S.; Kline, D.; Mark, J.; Ohi, J.; Rau, N. [National Renewable Energy Lab., Golden, CO (United States); Freeman, S.; Humphreys, K.; Placet, M. [Pacific Northwest National Lab., Richland, WA (United States)

1998-01-01

250

Optimal selection of biological tissue using the energy dissipated in the first loading cycle.  

PubMed

Calf pericardium, similar to that used in the manufacturing of prosthetic valve cusps, was fatigue tested. After six batches of 100 cycles of 1 MPa of loading pressure, half of the samples broke. The mean energy dissipated in the first cycle by the surviving samples was 0.16 J, which is lower than the 0.28 J dissipated by the specimens that broke (p = 0.005). The hysteresis of the first cycle was characteristic and different from the following ones and correlated superbly with fatigue resistance. Setting a threshold value for the energy of the first cycle of 0.20 J, the performance index (the percentage of true predictions) was almost 80%, and the area under the ROC curve was 0.823 (maximum value is 1). When including the mean thickness in the selection parameters, as an indirect measure of the specimen mass, the performance index grew over 95%, meaning that the error of the predictions was less than 5%. Combining both parameters in one, a high performance index is maintained at 87.5% and the area under the ROC curve increases to 0.917. This non-destructive method should help optical methods in the process of selecting the most appropriate and homogenous biological material. PMID:20878926

Rojo, Francisco J; García Páez, José M; Jorge-Herrero, Eduardo; Atienza, José M; Millán, Isabel; Rocha, Aurora; Fernández de Córdova, Alfonso Hoyos; Guinea, Gustavo V

2010-11-01

251

Thermochemical cycles for energy storage: Thermal decomposition of ZnCO sub 4 systems  

SciTech Connect

The overall objective of our research has been to develop thermochemical cycles that can be used for energy storage. A specific cycle involving ammonium hydrogen sulfate (NH{sub 4}HSO{sub 4}) has been proposed. Each reaction in the proposed cycle has been examined experimentally. Emphasis has been placed on the basic chemistry of these reactions. In the concluding phase of this research, reported herein, we have shown that when NH{sub 4}HSO{sub 4} is mixed with ZnO and decomposed, the resulting products can be released stepwise (H{sub 2}A{sub (g)} at {approximately}163{degrees}C, NH{sub 3(g)} at 365--418{degrees}C, and a mixture of SO{sub 2(g)} and SO{sub 3(g)} at {approximately}900{degrees}C) and separated by controlling the reaction temperature. Side reactions do not appear to be significant and the respective yields are high as would be required for the successful use of this energy storage reaction in the proposed cycle. Thermodynamic, kinetic, and other reaction parameters have been measured for the various steps of the reaction. Finally we have completed a detailed investigation of one particular reaction: the thermal decomposition of zinc sulfate (ZnSO{sub 4}). We have demonstrated that this reaction can be accelerated and the temperature required reduced by the addition of excess ZnO, V{sub 2}A{sub 5} and possibly other metal oxides.

Wentworth, W.E. (Houston Univ., TX (United States))

1992-04-01

252

Sorting through the many total-energy-cycle pathways possible with early plug-in hybrids.  

SciTech Connect

Using the 'total energy cycle' methodology, we compare U.S. near term (to {approx}2015) alternative pathways for converting energy to light-duty vehicle kilometers of travel (VKT) in plug-in hybrids (PHEVs), hybrids (HEVs), and conventional vehicles (CVs). For PHEVs, we present total energy-per-unit-of-VKT information two ways (1) energy from the grid during charge depletion (CD); (2) energy from stored on-board fossil fuel when charge sustaining (CS). We examine 'incremental sources of supply of liquid fuel such as (a) oil sands from Canada, (b) Fischer-Tropsch diesel via natural gas imported by LNG tanker, and (c) ethanol from cellulosic biomass. We compare such fuel pathways to various possible power converters producing electricity, including (i) new coal boilers, (ii) new integrated, gasified coal combined cycle (IGCC), (iii) existing natural gas fueled combined cycle (NGCC), (iv) existing natural gas combustion turbines, (v) wood-to-electricity, and (vi) wind/solar. We simulate a fuel cell HEV and also consider the possibility of a plug-in hybrid fuel cell vehicle (FCV). For the simulated FCV our results address the merits of converting some fuels to hydrogen to power the fuel cell vs. conversion of those same fuels to electricity to charge the PHEV battery. The investigation is confined to a U.S. compact sized car (i.e. a world passenger car). Where most other studies have focused on emissions (greenhouse gases and conventional air pollutants), this study focuses on identification of the pathway providing the most vehicle kilometers from each of five feedstocks examined. The GREET 1.7 fuel cycle model and the new GREET 2.7 vehicle cycle model were used as the foundation for this study. Total energy, energy by fuel type, total greenhouse gases (GHGs), volatile organic compounds (VOC), carbon monoxide (CO), nitrogen oxides (NO{sub x}), fine particulate (PM2.5) and sulfur oxides (SO{sub x}) values are presented. We also isolate the PHEV emissions contribution from varying kWh storage capability of battery packs in HEVs and PHEVs from {approx}16 to 64 km of charge depleting distance. Sensitivity analysis is conducted with respect to the effect of replacing the battery once during the vehicle's life. The paper includes one appendix that examines several recent studies of interactions of PHEVs with patterns of electric generation and one that provides definitions, acronyms, and fuel consumption estimation steps.

Gaines, L.; Burnham, A.; Rousseau, A.; Santini, D.; Energy Systems

2008-01-01

253

The effect of a caffeinated energy drink on various psychological measures during submaximal cycling.  

PubMed

Caffeine containing energy drinks is commonly consumed in the belief that it will enhance the quality of an exercise session and enhance mood. However, studies examining their efficacy are sparse. The aim of this study was to examine the effect of a caffeinated energy drink on leg pain perception, perceived exertion, mood state and readiness to invest effort pre, during and post 60 min cycling exercise. Fourteen active individuals (7 males, 7 females, mean age ± S.D.=23.5 ± 3.5 years), completed two 60 min cycling trials at an intensity of 60% VO2 max preceded by ingestion of solutions containing either a caffeinated energy drink or placebo using a double-blind, deceptive, crossover design. During exercise, RPE (6-20 scale), leg pain (0-10 scale), heart rate (HR) and blood lactate (Bla) were recorded. Participants also completed measures of mood state and readiness to invest physical effort (RTIPE) pre- and post-exercise. Repeated measures analysis of variance was used to assess differences in all variables and across time and treatments, with gender used as a between subjects variable. Results indicate that HR was significantly higher (P=.002) from 30 to 60 min and RPE (P=.0001) and pain perception (P=.0001) were significantly lower from 20 to 60 min in the energy drink condition compared to placebo. Bla was significantly higher (P=.021) in the last 15 min of the energy drink trial and RTIPE (P=.001) increased significantly more from pre-ingestion to pre-exercise post-ingestion in the energy drink condition compared to placebo. No gender differences were evident (P>.05). The data revealed positive effects of energy drink ingestion on perception of exertion, leg muscle pain perception and readiness to invest effort during submaximal cycling in active adults. PMID:23542532

Duncan, Michael J; Hankey, Joanne

2013-05-27

254

Energy Conservation Activities for Elementary Grades (Or: How to Help Slim Down the Energy Monster). Iowa Developed Energy Activities Sampler, Primary K-2.  

ERIC Educational Resources Information Center

The revised Iowa Developed Energy Activity Sampler (IDEAS) was compiled using the original IDEAS program and the Energy Conservation Activity Packets (ECAPS). This booklet provides activities for teachers to use in the primary elementary grades (K-2). The activities are organized into nine units, with units I through VIII containing three…

Iowa State Dept. of Education, Des Moines. Div. of Instructional Services.

255

Energy Conservation Activities for Elementary Grades (Or: How To Help Slim Down the Energy Monster). Iowa Developed Energy Activities Sampler, Primary K-2. Revised.  

ERIC Educational Resources Information Center

The revised Iowa Developed Energy Activity Sampler (IDEAS) was compiled using the original IDEAS program and the Energy Conservation Activity Packets (ECAPS). This booklet provides activities for teachers to use in the primary elementary grades (K-2). The activities are organized into nine units, with units 1 through 8 containing three activities…

Iowa State Dept. of Education, Des Moines.

256

Seawater Test Results of Open-Cycle Ocean Thermal Energy Conversion [OC-OTEC] Components  

Microsoft Academic Search

Key components of open-cycle ocean thermal energy conversion (OC-OTEC) systems—the flash evaporator, mist eliminator, passive predeaerator, two surface condenser stages, and mo direct-contact condenser stages—have been tested using seawater. These components operate at lower steam pressures and higher inlet noncondensable gas concentrations than do conventional power plant heat exchangers. The rate of heat exchanged between the evaporator and the condenser

F. Zangrando; D. Bharathan; H. Link; C. B. Panchal

1990-01-01

257

Screening of water-splitting thermochemical cycles potentially attractive for hydrogen production by concentrated solar energy  

Microsoft Academic Search

Hydrogen, a promising and clean energy carrier, could potentially replace the use of fossil fuels in the transportation sector. Currently, no environmentally attractive, large-scale, low-cost and high-efficiency hydrogen production process is available for commercialization. Solar-driven water-splitting thermochemical cycles may constitute one of the ultimate options for CO2-free production of hydrogen. The method is environmentally friendly since it uses only water

Stéphane Abanades; Patrice Charvin; Gilles Flamant; Pierre Neveu

2006-01-01

258

Vacuum thermal cycle life testing of high temperature thermal energy storage  

Microsoft Academic Search

Three fluoride-eutectic mixtures having 1000 K melting points and heats of fusion above 750 kJ\\/kg have been tested by an experimental program investigating the corrosion compatibility of high temperature thermal energy storage (TES) salts with their Inconel-617 containers. Electron beam-welded TES capsules were placed in a furnace for continuous thermal cycle life testing; the capsules have successfully undergone 4000 hrs

Rengasamy Ponnappan; Jerry E. Beam

1991-01-01

259

Numerical modelling of the energy and water cycle of the Baltic Sea  

Microsoft Academic Search

Summary   This paper will introduce the Baltex research programme and summarize associated numerical modelling work which has been\\u000a undertaken during the last five years. The research has broadly managed to clarify the main mechanisms determining the water\\u000a and energy cycle in the Baltic region, such as the strong dependence upon the large scale atmospheric circulation. It has\\u000a further been shown

L. Bengtsson

2001-01-01

260

Life cycle water use of energy production and its environmental impacts in China.  

PubMed

The energy sector is a major user of fresh water resources in China. We investigate the life cycle water withdrawals, consumptive water use, and wastewater discharge of China's energy sectors and their water-consumption-related environmental impacts, using a mixed-unit multiregional input-output (MRIO) model and life cycle impact assessment method (LCIA) based on the Eco-indicator 99 framework. Energy production is responsible for 61.4 billion m(3) water withdrawals, 10.8 billion m(3) water consumption, and 5.0 billion m(3) wastewater discharges in China, which are equivalent to 12.3%, 4.1% and 8.3% of the national totals, respectively. The most important feature of the energy-water nexus in China is the significantly uneven spatial distribution of consumptive water use and its corresponding environmental impacts caused by the geological discrepancy among fossil fuel resources, fresh water resources, and energy demand. More than half of energy-related water withdrawals occur in the east and south coastal regions. However, the arid north and northwest regions have much larger water consumption than the water abundant south region, and bear almost all environmental damages caused by consumptive water use. PMID:24125477

Zhang, Chao; Anadon, Laura Diaz

2013-12-17

261

Air Evaporation closed cycle water recovery technology - Advanced energy saving designs  

NASA Technical Reports Server (NTRS)

The Air Evaporation water recovery system is a visible candidate for Space Station application. A four-man Air Evaporation open cycle system has been successfully demonstrated for waste water recovery in manned chamber tests. The design improvements described in this paper greatly enhance the system operation and energy efficiency of the air evaporation process. A state-of-the-art wick feed design which results in reduced logistics requirements is presented. In addition, several design concepts that incorporate regenerative features to minimize the energy input to the system are discussed. These include a recuperative heat exchanger, a heat pump for energy transfer to the air heater, and solar collectors for evaporative heat. The addition of the energy recovery devices will result in an energy reduction of more than 80 percent over the systems used in earlier manned chamber tests.

Morasko, Gwyndolyn; Putnam, David F.; Bagdigian, Robert

1986-01-01

262

Life cycle comparison of waste-to-energy alternatives for municipal waste treatment in Chilean Patagonia.  

PubMed

The energy system in the Region of Aysén, Chile, is characterized by a strong dependence on fossil fuels, which account for up to 51% of the installed capacity. Although the implementation of waste-to-energy concepts in municipal waste management systems could support the establishment of a more fossil-independent energy system for the region, previous studies have concluded that energy recovery systems are not suitable from an economic perspective in Chile. Therefore, this work intends to evaluate these technical options from an environmental perspective, using life cycle assessment as a tool for a comparative analysis, considering Coyhaique city as a case study. Three technical alternatives were evaluated: (i) landfill gas recovery and flaring without energy recovery; (ii) landfill gas recovery and energy use; and (iii) the implementation of an anaerobic digestion system for the organic waste fraction coupled with energy recovery from the biogas produced. Mass and energy balances of the three analyzed alternatives have been modeled. The comparative LCA considered global warming potential, abiotic depletion and ozone layer depletion as impact categories, as well as required raw energy and produced energy as comparative regional-specific indicators. According to the results, the use of the recovered landfill gas as an energy source can be identified as the most environmentally appropriate solution for Coyhaique, especially when taking into consideration the global impact categories. PMID:23988463

Bezama, Alberto; Douglas, Carla; Méndez, Jacqueline; Szarka, Nóra; Muñoz, Edmundo; Navia, Rodrigo; Schock, Steffen; Konrad, Odorico; Ulloa, Claudia

2013-10-01

263

One-year monitoring of reproductive and energy reserve cycles in transplanted zebra mussels (Dreissena polymorpha).  

PubMed

A 12-month active biomonitoring study was performed in 2008-2009 on a northern French river system using the freshwater mussel Dreissena polymorpha as a sentinel species. Allochtonous mussels originating from a reference site (Commercy) were caged at four sites (Bouy, Sept-Saulx, Fismes, Ardre) within the Vesle River basin. The main objective of the study was to characterize the influence of biotic (sex, food availability) and abiotic (temperature, chemicals) factors on the reproductive and energy reserve (glycogen, lipids) cycles of exposed mussels. Both cycles were markedly disturbed at the Bouy and Sept-Saulx sites where the lowest chlorophyll a levels were recorded during the study. At these sites, mussels obviously faced a negative energy balance, as confirmed by the impairment of their physiological state and byssal attachment. At other exposure sites, reproductive and energy reserves cycles were less impacted but were still dependent on the nutritional state of mussels. The latter appeared as a significant natural confounding factor in ecotoxicological survey performed in low polluted areas. PMID:21345479

Palais, F; Mouneyrac, C; Dedourge-Geffard, O; Giambérini, L; Biagianti-Risbourg, S; Geffard, A

2011-05-01

264

Ideal energy harvesting cycle using a phase transformation in ferroelectric crystals  

NASA Astrophysics Data System (ADS)

A near ideal mechanical-to-electrical energy harvesting cycle that takes advantage of a stress driven ferroelectric–ferroelectric phase transformation was demonstrated in ?ft[ 011 \\right] oriented Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT). The cycle involves loading and unloading the material between two compressive stress loads under open-circuit conditions. The compressive stress loads exceed the coercive stresses required to drive the forward and reverse phase transformation; however, open-circuit conditions result in the surface charge on the electrodes producing an electric field that hinders the phase transformation. The crystal is then discharged through a shunt resistor at constant stress. The phase transformation takes place during the discharge and results in a charge output that is significantly greater than that of a linear piezoelectric material. An output electrical energy density of 6.22 kJ m?3 per cycle was demonstrated for a stress loading interval from ?14 to ?25 MPa and the peak efficiency was measured to be 36% for a stress loading interval of ?16.5 to ?22.5 MPa. Although electrical output increases with the stress loading interval, charge leakage at high electric fields occurred for large stress intervals. This placed a limit on the maximum energy density achievable.

Dong, Wen D.; Gallagher, John A.; Lynch, Christopher S.

2014-12-01

265

Energy and carbon dioxide (CO2) balance of logging residues as alternative energy resources: system analysis based on the method of a life cycle inventory (LCI) analysis  

Microsoft Academic Search

Using the method of a life cycle inventory (LCI) analysis, the energy balance and the carbon dioxide (CO2) emission of logging residues from Japanese conventional forestry as alternative energy resources were analyzed over the entire life cycle of the residues. The fuel consumption for forestry machines was measured in field experiments for harvesting and transporting logging residues at forestry operating

Takuyuki Yoshioka; Kazuhiro Aruga; Toshio Nitami; Hiroshi Kobayashi; Hideo Sakai

2005-01-01

266

Open-cycle Ocean Thermal Energy Conversion (OTEC): Status and potential  

NASA Astrophysics Data System (ADS)

Tropical oceans with a 20 C or more temperature difference between surface and deep water represent a vast resource of renewable thermal energy. One of the methods of harnessing this resource is an open-cycle Ocean Thermal Energy Conversion (OTEC) system utilizing steam evaporated from the surface water for powering the turbine. In this paper, the state of the art of research and component development, as related to heat and mass transfer processes, power production, noncondensable gas handling, and seawater flow hydraulics, are described through an illustrated preliminary design study of a 1-MW facility.

Bharathan, D.

1984-08-01

267

Approximation Algorithms for Minimum Energy Transmission in Rate and Duty-Cycle Constrained Wireless Networks  

Microsoft Academic Search

Abstract—We,consider,a,constrained,energy,optimization problem for wireless networks, where the constraints arise because,of interference between,wireless nodes,that limits their transmission,rates along with load and,duty-cycle (on-off) re- strictions. Since traditional optimization,methods,using Lagrange multipliers do not work,well and,are computationally,expensive given the non-convex constraints, we develop fully polynomial approximation,schemes,(FPAS) for finding the optimal (minimum energy) transmission,schedule,by discretizing power,levels over the interference channel. For any > 0, we

Rajgopal Kannan; Vasu Chakravarthy; Wright-Patterson AFB; Murali Rangaswamy

268

Life-cycle energy savings potential from aluminum-intensive vehicles  

SciTech Connect

The life-cycle energy and fuel-use impacts of US-produced aluminum-intensive passenger cars and passenger trucks are assessed. The energy analysis includes vehicle fuel consumption, material production energy, and recycling energy. A model that stimulates market dynamics was used to project aluminum-intensive vehicle market shares and national energy savings potential for the period between 2005 and 2030. We conclude that there is a net energy savings with the use of aluminum-intensive vehicles. Manufacturing costs must be reduced to achieve significant market penetration of aluminum-intensive vehicles. The petroleum energy saved from improved fuel efficiency offsets the additional energy needed to manufacture aluminum compared to steel. The energy needed to make aluminum can be reduced further if wrought aluminum is recycled back to wrought aluminum. We find that oil use is displaced by additional use of natural gas and nonfossil energy, but use of coal is lower. Many of the results are not necessarily applicable to vehicles built outside of the United States, but others could be used with caution.

Stodolsky, F.; Vyas, A.; Cuenca, R.; Gaines, L.

1995-07-01

269

Technology for Bayton-cycle powerplants using solar and nuclear energy  

NASA Technical Reports Server (NTRS)

Brayton cycle gas turbines have the potential to use either solar heat or nuclear reactors for generating from tens of kilowatts to tens of megawatts of power in space, all this from a single technology for the power generating system. Their development for solar energy dynamic power generation for the space station could be the first step in an evolution of such powerplants for a very wide range of applications. At the low power level of only 10 kWe, a power generating system has already demonstrated overall efficiency of 0.29 and operated 38 000 hr. Tests of improved components show that these components would raise that efficiency to 0.32, a value twice that demonstrated by any alternate concept. Because of this high efficiency, solar Brayton cycle power generators offer the potential to increase power per unit of solar collector area to levels exceeding four times that from photovoltaic powerplants using present technology for silicon solar cells. The technologies for solar mirrors and heat receivers are reviewed and assessed. This Brayton technology for solar powerplants is equally suitable for use with the nuclear reactors. The available long time creep data on the tantalum alloy ASTAR-811C show that such Brayton cycles can evolve to cycle peak temperatures of 1500 K (2240 F). And this same technology can be extended to generate 10 to 100 MW in space by exploiting existing technology for terrestrial gas turbines in the fields of both aircraft propulsion and stationary power generation.

English, R. E.

1986-01-01

270

High Temperature Fusion Reactor Cooling Using Brayton Cycle Based Partial Energy Conversion  

NASA Technical Reports Server (NTRS)

For some future space power systems using high temperature nuclear heat sources most of the output energy will be used in other than electrical form, and only a fraction of the total thermal energy generated will need to be converted to electrical work. The paper describes the conceptual design of such a partial energy conversion system, consisting of a high temperature fusion reactor operating in series with a high temperature radiator and in parallel with dual closed cycle gas turbine (CCGT) power systems, also referred to as closed Brayton cycle (CBC) systems, which are supplied with a fraction of the reactor thermal energy for conversion to electric power. Most of the fusion reactor's output is in the form of charged plasma which is expanded through a magnetic nozzle of the interplanetary propulsion system. Reactor heat energy is ducted to the high temperature series radiator utilizing the electric power generated to drive a helium gas circulation fan. In addition to discussing the thermodynamic aspects of the system design the authors include a brief overview of the gas turbine and fan rotor-dynamics and proposed bearing support technology along with performance characteristics of the three phase AC electric power generator and fan drive motor.

Juhasz, Albert J.; Sawicki, Jerzy T.

2003-01-01

271

High Temperature Fusion Reactor Cooling Using Brayton Cycle Based Partial Energy Conversion  

NASA Astrophysics Data System (ADS)

For some future space power systems using high temperature nuclear heat sources most of the output energy will be used in other than electrical form, and only a fraction of the total thermal energy generated will need to be converted to electrical work. The paper describes the conceptual design of such a ``partial energy conversion'' system, consisting of a high temperature fusion reactor operating in series with a high temperature radiator and in parallel with dual closed cycle gas turbine (CCGT) power systems, also referred to as closed Brayton cycle (CBC) systems, which are supplied with a fraction of the reactor thermal energy for conversion to electric power. Most of the fusion reactor's output is in the form of charged plasma which is expanded through a magnetic nozzle of the interplanetary propulsion system. Reactor heat energy is ducted to the high temperature series radiator utilizing the electric power generated to drive a helium gas circulation fan. In addition to discussing the thermodynamic aspects of the system design the authors include a brief overview of the gas turbine and fan rotor-dynamics and proposed bearing support technology along with performance characteristics of the three phase AC electric power generator and fan drive motor.

Juhasz, Albert J.; Sawicki, Jerzy T.

2004-02-01

272

Life cycle assessment of energy from waste via anaerobic digestion: a UK case study.  

PubMed

Particularly in the UK, there is potential for use of large-scale anaerobic digestion (AD) plants to treat food waste, possibly along with other organic wastes, to produce biogas. This paper presents the results of a life cycle assessment to compare the environmental impacts of AD with energy and organic fertiliser production against two alternative approaches: incineration with energy production by CHP and landfill with electricity production. In particular the paper investigates the dependency of the results on some specific assumptions and key process parameters. The input Life Cycle Inventory data are specific to the Greater London area, UK. Anaerobic digestion emerges as the best treatment option in terms of total CO2 and total SO2 saved, when energy and organic fertiliser substitute non-renewable electricity, heat and inorganic fertiliser. For photochemical ozone and nutrient enrichment potentials, AD is the second option while incineration is shown to be the most environmentally friendly solution. The robustness of the model is investigated with a sensitivity analysis. The most critical assumption concerns the quantity and quality of the energy substituted by the biogas production. Two key issues affect the development and deployment of future anaerobic digestion plants: maximising the electricity produced by the CHP unit fuelled by biogas and to defining the future energy scenario in which the plant will be embedded. PMID:24112851

Evangelisti, Sara; Lettieri, Paola; Borello, Domenico; Clift, Roland

2014-01-01

273

Comparing Life-Cycle Costs of ESPCs and Appropriations-Funded Energy Projects: An Update to the 2002 Report  

SciTech Connect

A study was sponsored by FEMP in 2001 - 2002 to develop methods to compare life-cycle costs of federal energy conservation projects carried out through energy savings performance contracts (ESPCs) and projects that are directly funded by appropriations. The study described in this report follows up on the original work, taking advantage of new pricing data on equipment and on $500 million worth of Super ESPC projects awarded since the end of FY 2001. The methods developed to compare life-cycle costs of ESPCs and directly funded energy projects are based on the following tasks: (1) Verify the parity of equipment prices in ESPC vs. directly funded projects; (2) Develop a representative energy conservation project; (3) Determine representative cycle times for both ESPCs and appropriations-funded projects; (4) Model the representative energy project implemented through an ESPC and through appropriations funding; and (5) Calculate the life-cycle costs for each project.

Shonder, John A [ORNL; Hughes, Patrick [ORNL; Atkin, Erica [ORNL

2006-11-01

274

Analyzing the Life Cycle Energy Savings of DOE Supported Buildings Technologies  

SciTech Connect

This report examines the factors that would potentially help determine an appropriate analytical timeframe for measuring the U.S. Department of Energy's Building Technology (BT) benefits and presents a summary-level analysis of the life cycle savings for BT’s Commercial Buildings Integration (CBI) R&D program. The energy savings for three hypothetical building designs are projected over a 100-year period using Building Energy Analysis and Modeling System (BEAMS) to illustrate the resulting energy and carbon savings associated with the hypothetical aging buildings. The report identifies the tasks required to develop a long-term analytical and modeling framework, and discusses the potential analytical gains and losses by extending an analysis into the “long-term.”

Cort, Katherine A.; Hostick, Donna J.; Dirks, James A.; Elliott, Douglas B.

2009-08-31

275

Life-cycle energy consumption and greenhouse gas emissions for electricity generation and supply in China  

Microsoft Academic Search

The Well-to-Meter (WTM) analysis module in the Tsinghua-CA3EM model has been used to examine the primary fossil energy consumption (PFEC) and greenhouse gas (GHG) emissions for electricity generation and supply in China. The results show that (1) the WTM PFEC and GHG emission intensities for the 2007 Chinese electricity mix are 3.247MJ\\/MJ and 297.688g carbon dioxide of equivalent (gCO2,e)\\/MJ, respectively;

Xunmin Ou; Yan Xiaoyu; Xiliang Zhang

2011-01-01

276

Proceeding of Energy Week 1996, ASME APPLICATION OF THE U.S. HIGH CYCLE FATIGUE DATA BASE  

E-print Network

Proceeding of Energy Week 1996, ASME APPLICATION OF THE U.S. HIGH CYCLE FATIGUE DATA BASE TO WIND the service lifetime of wind turbine blades using the high-cycle fatigue data base for typical U.S. blade (composed primarily of data obtained from specialized, relatively small coupons) with fatigue data from

277

A Life-Cycle Assessment of Biofuels: Tracing Energy and Carbon through a Fuel-Production System  

ERIC Educational Resources Information Center

A life-cycle assessment (LCA) is a tool used by engineers to make measurements of net energy, greenhouse gas production, water consumption, and other items of concern. This article describes an activity designed to walk students through the qualitative part of an LCA. It asks them to consider the life-cycle costs of ethanol production, in terms of…

Krauskopf, Sara

2010-01-01

278

Review of cooperative research on thorium fuel cycle as a promising energy source in the next century  

Microsoft Academic Search

Aiming at building up the scientific and technical foundation for the development of the thorium fuel cycle, we carried out a cooperative fundamental study on this cycle as a promising energy source in and after the next century by the support of Grant-in-Aid for Scientific Research by the Ministry of Education, Science and Culture of Japanese Government from April 1988

I Kimura

1995-01-01

279

A Cumulative Energy Demand indicator (CED), life cycle based, for industrial waste management decision making  

SciTech Connect

Highlights: • We developed a methodology useful to environmentally compare industrial waste management options. • The methodology uses a Net Energy Demand indicator which is life cycle based. • The method was simplified to be widely used, thus avoiding cost driven decisions. • This methodology is useful for governments to promote the best environmental options. • This methodology can be widely used by other countries or regions around the world. - Abstract: Life cycle thinking is a good approach to be used for environmental decision-support, although the complexity of the Life Cycle Assessment (LCA) studies sometimes prevents their wide use. The purpose of this paper is to show how LCA methodology can be simplified to be more useful for certain applications. In order to improve waste management in Catalonia (Spain), a Cumulative Energy Demand indicator (LCA-based) has been used to obtain four mathematical models to help the government in the decision of preventing or allowing a specific waste from going out of the borders. The conceptual equations and all the subsequent developments and assumptions made to obtain the simplified models are presented. One of the four models is discussed in detail, presenting the final simplified equation to be subsequently used by the government in decision making. The resulting model has been found to be scientifically robust, simple to implement and, above all, fulfilling its purpose: the limitation of waste transport out of Catalonia unless the waste recovery operations are significantly better and justify this transport.

Puig, Rita, E-mail: rita.puig@eei.upc.edu [Escola d’Enginyeria d’Igualada (EEI), Universitat Politècnica de Catalunya (UPC), Plaça del Rei, 15, 08700 Igualada (Spain); Fullana-i-Palmer, Pere [UNESCO Chair in Life Cycle and Climate Change, Escola Superior de Comerç Internacional, Universitat Pompeu Fabra (UPF), c/Passeig Pujades, 1, 08003 Barcelona (Spain); Baquero, Grau; Riba, Jordi-Roger [Escola d’Enginyeria d’Igualada (EEI), Universitat Politècnica de Catalunya (UPC), Plaça del Rei, 15, 08700 Igualada (Spain); Bala, Alba [UNESCO Chair in Life Cycle and Climate Change, Escola Superior de Comerç Internacional, Universitat Pompeu Fabra (UPF), c/Passeig Pujades, 1, 08003 Barcelona (Spain)

2013-12-15

280

Strengthening of the hydrological cycle in future scenarios: atmospheric energy and water balance perspective  

NASA Astrophysics Data System (ADS)

Future climate scenarios experiencing global warming are expected to strengthen hydrological cycle during 21st century by comparison with the last decades of 20th century. We analyze strengthening of the global-scale increase in precipitation from the perspective of changes in whole atmospheric water and energy balances. Furthermore, by combining energy and water equations for the whole atmosphere we profitably obtain constraints for the changes in surface fluxes and for the partitioning at the surface between sensible and latent components. Above approach is applied to investigate difference in strengthening of hydrological cycle in two scenario centennial simulations performed with an Earth System model forced with specified atmospheric concentration pathways. Alongside the medium-high non-mitigation scenario SRES A1B, we considered a new aggressive-mitigation scenario (E1) with reduced fossil fuel use for energy production aimed at stabilizing global warming below 2 K. Quite unexpectedly, mitigation scenario is shown to strengthen hydrological cycle more than SRES A1B till around 2070. Our analysis shows that this is mostly a consequence of the larger increase in the negative radiative imbalance of atmosphere in E1 compared to A1B. This appears to be primarily related to the abated aerosol concentration in E1, which considerably reduces atmospheric absorption of solar radiation compared to A1B. In contrast, last decades of 21st century (21C) show marked increase of global precipitation in A1B compared to E1, despite the fact that the two scenarios display almost same overall increase of radiative imbalance with respect to 20th century. Our results show that radiative cooling is weakly effective in A1B throughout all 21C, so that two distinct mechanisms characterize the diverse strengthening of hydrological cycle in mid and end 21C. It is only through a very large perturbation of surface fluxes that A1B achieves larger increase of global precipitation in the last decades of 21C. Our energy/water budget analysis shows that this behavior is ultimately due to a bifurcation in the Bowen ratios change between the two scenarios. This work warns that mitigation policies, by abating aerosols, may lead to unexpected stronger intensification of hydrological cycle and associated changes that may last for decades after that global warming is effectively mitigated. On the other hand, it is here suggested that predictable components of the radiative forcing by aerosols may have the potential to effectively contribute to the decadal-scale predictability of changes in the hydrological strength.

Alessandri, A.; Fogli, P. G.; Vichi, M.; Zeng, N.

2012-07-01

281

Towards Robust Energy Systems Modeling: Examinging Uncertainty in Fossil Fuel-Based Life Cycle Assessment Approaches  

NASA Astrophysics Data System (ADS)

Increasing concerns about the environmental impacts of fossil fuels used in the U.S. transportation and electricity sectors have spurred interest in alternate energy sources, such as natural gas and biofuels. Life cycle assessment (LCA) methods can be used to estimate the environmental impacts of incumbent energy sources and potential impact reductions achievable through the use of alternate energy sources. Some recent U.S. climate policies have used the results of LCAs to encourage the use of low carbon fuels to meet future energy demands in the U.S. However, the LCA methods used to estimate potential reductions in environmental impact have some drawbacks. First, the LCAs are predominantly based on deterministic approaches that do not account for any uncertainty inherent in life cycle data and methods. Such methods overstate the accuracy of the point estimate results, which could in turn lead to incorrect and (consequent) expensive decision-making. Second, system boundaries considered by most LCA studies tend to be limited (considered a manifestation of uncertainty in LCA). Although LCAs can estimate the benefits of transitioning to energy systems of lower environmental impact, they may not be able to characterize real world systems perfectly. Improved modeling of energy systems mechanisms can provide more accurate representations of reality and define more likely limits on potential environmental impact reductions. This dissertation quantitatively and qualitatively examines the limitations in LCA studies outlined previously. The first three research chapters address the uncertainty in life cycle greenhouse gas (GHG) emissions associated with petroleum-based fuels, natural gas and coal consumed in the U.S. The uncertainty in life cycle GHG emissions from fossil fuels was found to range between 13 and 18% of their respective mean values. For instance, the 90% confidence interval of the life cycle GHG emissions of average natural gas consumed in the U.S was found to range between -8 to 9% (17%) of the mean value of 66 g CO2e/MJ. Results indicate that uncertainty affects the conclusions of comparative life cycle assessments, especially when differences in average environmental impacts between two competing fuels/products are small. In the final two research chapters of this thesis, system boundary limitations in LCA are addressed. Simplified economic dispatch models for are developed to examine changes in regional power plant dispatch that occur when coal power plants are retired and when natural gas prices drop. These models better reflect reality by estimating the order in which existing power plants are dispatched to meet electricity demand based on short-run marginal costs. Results indicate that the reduction in air emissions are lower than suggested by LCA studies, since they generally do not include the complexity of regional electricity grids, predominantly driven by comparative fuel prices. For instance, comparison, this study estimates 7-15% reductions in emissions with low natural gas prices. Although this is a significant reduction in itself, it is still lower than the benefits reported in traditional life cycle comparisons of coal and natural gas-based power (close to 50%), mainly due to the effects of plant dispatch.

Venkatesh, Aranya

282

Life-cycle costs for the Department of Energy Waste Management Programmatic Environmental Impact Statement  

SciTech Connect

The US Department of Energy (DOE) Office of Environmental Management has produced a Programmatic Environmental Impact Statement (PEIS) in order to assess the potential consequences resulting from a cross section of possible waste management strategies for the DOE complex. The PEIS has been prepared in compliance with the NEPA and includes evaluations of a variety of alternatives. The analysis performed for the PEIS included the development of life-cycle cost estimates for the different waste management alternatives being considered. These cost estimates were used in the PEIS to support the identification and evaluation of economic impacts. Information developed during the preparation of the life-cycle cost estimates was also used to support risk and socioeconomic analyses performed for each of the alternatives. This technical report provides an overview of the methodology used to develop the life-cycle cost estimates for the PEIS alternatives. The methodology that was applied made use of the Waste Management Facility Cost Information Reports, which provided a consistent approach and estimating basis for the PEIS cost evaluations. By maintaining consistency throughout the cost analyses, life-cycle costs of the various alternatives can be compared and evaluated on a relative basis. This technical report also includes the life-cycle cost estimate results for each of the PEIS alternatives evaluated. Summary graphs showing the results for each waste type are provided and tables showing different breakdowns of the cost estimates are provided. Appendix E contains PEIS cost information that was developed using an approach different than the standard methodology described in this report. Specifically, costs for high-level waste are found in this section, as well as supplemental costs for additional low-level waste and hazardous waste alternatives.

Sherick, M.J.; Shropshire, D.E.; Hsu, K.M.

1996-09-01

283

Thermal energy storage for low grade heat in the organic Rankine cycle  

NASA Astrophysics Data System (ADS)

Limits of efficiencies cause immense amounts of thermal energy in the form of waste heat to be vented to the atmosphere. Up to 60% of unrecovered waste heat is classified as low or ultra-low quality, making recovery difficult or inefficient. The organic Rankine cycle can be used to generate mechanical power and electricity from these low temperatures where other thermal cycles are impractical. A variety of organic working fluids are available to optimize the ORC for any target temperature range. San Diego State University has one such experimental ORC using R245fa, and has been experimenting with multiple expanders. One limitation of recovering waste heat is the sporadic or cyclical nature common to its production. This inconsistency makes sizing heat recovery ORC systems difficult for a variety of reasons including off-design-point efficiency loss, increased attrition from varying loads, unreliable outputs, and overall system costs. Thermal energy storage systems can address all of these issues by smoothing the thermal input to a constant and reliable level and providing back-up capacity for times when the thermal input is deactivated. Multiple types of thermal energy storage have been explored including sensible, latent, and thermochemical. Latent heat storage involves storing thermal energy in the reversible phase change of a phase change material, or PCM, and can have several advantages over other modalities including energy storage density, cost, simplicity, reliability, relatively constant temperature output, and temperature customizability. The largest obstacles to using latent heat storage include heat transfer rates, thermal cycling stability, and potentially corrosive PCMs. Targeting 86°C, the operating temperature of SDSU's experimental ORC, multiple potential materials were explored and tested as potential PCMs including Magnesium Chloride Hexahydrate (MgCl2?6H2O), Magnesium Nitrate Hexahydrate (Mg(NO3)2?6H 2O), montan wax, and carnauba wax. The addition of graphite to augment heat transfer rates was also tested. Melting and solidification temperatures largely matched predictions. The magnesium salts were found to be less stable under thermal cycling than the waxes. Graphite was only soluble in the waxes. Mixtures of magnesium salts and waxes yielded a layered composite with the less dense waxes creating a sealing layer over the salt layer that significantly increased the stability of the magnesium salts. Research into optimum heat exchangers and storage vessels for these applications indicates that horizontally oriented aluminum pipes with vertically oriented aluminum fins would be the best method of storing and retrieving energy. Fin spacing can be predicted by an equation based on target temperatures and PCM characteristics.

Soda, Michael John

284

Resonance Raman Analysis of the Mechanism of Energy Storage and Chromophore Distortion in the Primary Visual Photoproduct  

E-print Network

Resonance Raman Analysis of the Mechanism of Energy Storage and Chromophore Distortion modes and their relation to energy storage in the primary photoproduct. Low-temperature (77 K) resonance interactions of the 9- and 13-methyl groups with surrounding residues. This distortion stores light energy

Chang, Belinda

285

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

PubMed

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. PMID:25758908

Burnley, Stephen; Coleman, Terry; Peirce, Adam

2015-05-01

286

Comparison of life-cycle energy and emissions footprints of passenger transportation in metropolitan regions  

NASA Astrophysics Data System (ADS)

A comparative life-cycle energy and emissions (greenhouse gas, CO, NO X, SO 2, PM 10, and VOCs) inventory is created for three U.S. metropolitan regions (San Francisco, Chicago, and New York City). The inventory captures both vehicle operation (direct fuel or electricity consumption) and non-operation components (e.g., vehicle manufacturing, roadway maintenance, infrastructure operation, and material production among others). While urban transportation inventories have been continually improved, little information exists identifying the particular characteristics of metropolitan passenger transportation and why one region may differ from the next. Using travel surveys and recently developed transportation life-cycle inventories, metropolitan inventories are constructed and compared. Automobiles dominate total regional performance accounting for 86-96% of energy consumption and emissions. Comparing system-wide averages, New York City shows the lowest end-use energy and greenhouse gas footprint compared to San Francisco and Chicago and is influenced by the larger share of transit ridership. While automobile fuel combustion is a large component of emissions, diesel rail, electric rail, and ferry service can also have strong contributions. Additionally, the inclusion of life-cycle processes necessary for any transportation mode results in significant increases (as large as 20 times that of vehicle operation) for the region. In particular, emissions of CO 2 from cement production used in concrete throughout infrastructure, SO 2 from electricity generation in non-operational components (vehicle manufacturing, electricity for infrastructure materials, and fuel refining), PM 10 in fugitive dust releases in roadway construction, and VOCs from asphalt result in significant additional inventory. Private and public transportation are disaggregated as well as off-peak and peak travel times. Furthermore, emissions are joined with healthcare and greenhouse gas monetized externalities to evaluate the societal costs of passenger transportation in each region. Results are validated against existing studies. The dominating contribution of automobile end-use energy consumption and emissions is discussed and strategies for improving regional performance given private travel's disproportionate share are identified.

Chester, Mikhail V.; Horvath, Arpad; Madanat, Samer

2010-03-01

287

Energy Landscape Reveals That the Budding Yeast Cell Cycle Is a Robust and Adaptive Multi-stage Process.  

PubMed

Quantitatively understanding the robustness, adaptivity and efficiency of cell cycle dynamics under the influence of noise is a fundamental but difficult question to answer for most eukaryotic organisms. Using a simplified budding yeast cell cycle model perturbed by intrinsic noise, we systematically explore these issues from an energy landscape point of view by constructing an energy landscape for the considered system based on large deviation theory. Analysis shows that the cell cycle trajectory is sharply confined by the ambient energy barrier, and the landscape along this trajectory exhibits a generally flat shape. We explain the evolution of the system on this flat path by incorporating its non-gradient nature. Furthermore, we illustrate how this global landscape changes in response to external signals, observing a nice transformation of the landscapes as the excitable system approaches a limit cycle system when nutrients are sufficient, as well as the formation of additional energy wells when the DNA replication checkpoint is activated. By taking into account the finite volume effect, we find additional pits along the flat cycle path in the landscape associated with the checkpoint mechanism of the cell cycle. The difference between the landscapes induced by intrinsic and extrinsic noise is also discussed. In our opinion, this meticulous structure of the energy landscape for our simplified model is of general interest to other cell cycle dynamics, and the proposed methods can be applied to study similar biological systems. PMID:25794282

Lv, Cheng; Li, Xiaoguang; Li, Fangting; Li, Tiejun

2015-03-01

288

Energy Landscape Reveals That the Budding Yeast Cell Cycle Is a Robust and Adaptive Multi-stage Process  

PubMed Central

Quantitatively understanding the robustness, adaptivity and efficiency of cell cycle dynamics under the influence of noise is a fundamental but difficult question to answer for most eukaryotic organisms. Using a simplified budding yeast cell cycle model perturbed by intrinsic noise, we systematically explore these issues from an energy landscape point of view by constructing an energy landscape for the considered system based on large deviation theory. Analysis shows that the cell cycle trajectory is sharply confined by the ambient energy barrier, and the landscape along this trajectory exhibits a generally flat shape. We explain the evolution of the system on this flat path by incorporating its non-gradient nature. Furthermore, we illustrate how this global landscape changes in response to external signals, observing a nice transformation of the landscapes as the excitable system approaches a limit cycle system when nutrients are sufficient, as well as the formation of additional energy wells when the DNA replication checkpoint is activated. By taking into account the finite volume effect, we find additional pits along the flat cycle path in the landscape associated with the checkpoint mechanism of the cell cycle. The difference between the landscapes induced by intrinsic and extrinsic noise is also discussed. In our opinion, this meticulous structure of the energy landscape for our simplified model is of general interest to other cell cycle dynamics, and the proposed methods can be applied to study similar biological systems. PMID:25794282

Lv, Cheng; Li, Xiaoguang; Li, Fangting; Li, Tiejun

2015-01-01

289

Deep Horizons - Implications of the deep carbon cycle for life, energy, and the environment (Invited)  

NASA Astrophysics Data System (ADS)

B. Sherwood Lollar1, C.J. Ballentine2, E. Shock3 1Dept. of Geology, University of Toronto, Toronto, Ontario, Canada M5S 3B1 email bslollar@chem.utoronto.ca 2School of Earth, Atmospheric & Environ. Sci., Univ. of Manchester, UK M13 9PL 3School of Earth & Space Exploration, Arizona State Univ., Tempe, AZ 85287-1404 While well-developed models exist regarding surface biogeochemical carbon cycles on short-, medium- and long-term scales over geologic time, major unknowns persist concerning the deep carbon cycle, including the pathways and flux of carbon exchange between the surface and deep interior of the planet; the nature of microbial life in the Earth's deep subsurface; and the implications of the deep carbon cycle for energy resources and the environment. Major research questions include: What is the distribution, form and abundance of carbon in the deep crust and mantle? What is the nature of deep carbon flux and the timescale and mechanisms of recycling? Do the lower crust and mantle contribute biologically available carbon to the shallow subsurface and surface? To what extent does the deep carbon cycle support microbial ecosystems in the deep marine and/or deep terrestrial biosphere? What is the volume and depth of the Earth's habitable zone and what are the implications of this for the search for life on other planets and moons? What is the role of the deep carbon cycle in sustaining abiotic organic synthesis and what potential contribution might such chemical organic synthesis have made to the origin of life and the sustainability of deep microbial ecosystems? How does our understanding of the deep carbon cycle impact on emerging global issues such as climate change, energy and carbon sequestration? While fundamental to our understanding of the origin and evolution of life and the planet - these questions are also relevant to the major practical challenges facing science and society as we struggle with the implications of still increasing fossil fuel dependence, and with the challenges and consequences of exploration and extraction of deeper hydrocarbon reserves. Management of remaining hydrocarbon resources, possibilities for subsurface carbon storage, the search for cleaner fuels, and solutions to rising levels of atmospheric carbon dioxide all urgently require a better understanding of deep carbon.

Sherwood Lollar, B.; Ballentine, C. J.; Shock, E.

2010-12-01

290

Experimental reconstruction of excitation energies of primary hot isotopes in heavy ion collisions near the Fermi energy  

NASA Astrophysics Data System (ADS)

The excitation energies of the primary hot isotopes in multifragmentation events are experimentally reconstructed in the reaction system 64Zn + 112Sn at 40 MeV/nucleon. A kinematical focusing method is employed to evaluate the multiplicities of the evaporated light particles associated with isotopically identified fragments with 3?Z?14. Angular distributions of the velocity spectra of light charged particles and neutrons associated with trigger isotopes are examined. A moving source fit is used to separate the kinematically correlated particles, evaporated from the parents of the detected isotopes, from the uncorrelated particles originating from other sources. The latter are evaluated experimentally relative to those in coincidence with the Li isotopes. A parameter, k, is used to adjust the yield of the uncorrelated particles for different trigger isotopes. For each experimentally detected isotope, the multiplicities, apparent temperatures, and k values for n, p, d, t, and ? particles are extracted. Using the extracted values, the excitation energies of the primary hot isotopes are reconstructed employing a Monte Carlo method. The extracted excitation energies are in the range of 1 to 4 MeV/nucleon but show a significant decreasing trend as a function of A for a given Z of the isotopes. The results are compared with those of antisymmetrized molecular dynamics (AMD) and statistical multifragmentation model (SMM) simulations. While some of the experimental characteristics are predicted partially by each model, neither simulation reproduces the overall characteristics of the experimental results.

Rodrigues, M. R. D.; Lin, W.; Liu, X.; Huang, M.; Zhang, S.; Chen, Z.; Wang, J.; Wada, R.; Kowalski, S.; Keutgen, T.; Hagel, K.; Barbui, M.; Bottosso, C.; Bonasera, A.; Natowitz, J. B.; Materna, T.; Qin, L.; Sahu, P. K.; Schmidt, K. J.

2013-09-01

291

Rankine cycle condenser pressure control using an energy conversion device bypass valve  

DOEpatents

The disclosure provides a waste heat recovery system and method in which pressure in a Rankine cycle (RC) system of the WHR system is regulated by diverting working fluid from entering an inlet of an energy conversion device of the RC system. In the system, an inlet of a controllable bypass valve is fluidly coupled to a working fluid path upstream of an energy conversion device of the RC system, and an outlet of the bypass valve is fluidly coupled to the working fluid path upstream of the condenser of the RC system such that working fluid passing through the bypass valve bypasses the energy conversion device and increases the pressure in a condenser. A controller determines the temperature and pressure of the working fluid and controls the bypass valve to regulate pressure in the condenser.

Ernst, Timothy C; Nelson, Christopher R; Zigan, James A

2014-04-01

292

Cost and energy consumption estimates for the aluminum-air battery anode fuel cycle  

SciTech Connect

At the request of DOE's Office of Energy Storage and Distribution (OESD), Pacific Northwest Laboratory (PNL) conducted a study to generate estimates of the energy use and costs associated with the aluminum anode fuel cycle of the aluminum-air (Al-air) battery. The results of this analysis indicate that the cost and energy consumption characteristics of the mechanically rechargeable Al-air battery system are not as attractive as some other electrically rechargeable electric vehicle battery systems being developed by OESD. However, there are distinct advantages to mechanically rechargeable batteries, which may make the Al-air battery (or other mechanically rechargeable batteries) attractive for other uses, such as stand-alone applications. Fuel cells, such as the proton exchange membrane (PEM), and advanced secondary batteries may be better suited to electric vehicle applications. 26 refs., 3 figs., 25 tabs.

Humphreys, K.K.; Brown, D.R.

1990-01-01

293

On the nonlinear feedback loop and energy cycle of the non-dissipative Lorenz model  

NASA Astrophysics Data System (ADS)

In this study, we discuss the role of the nonlinear terms and linear (heating) term in the energy cycle of the three-dimensional (X-Y-Z) non-dissipative Lorenz model (3D-NLM). (X, Y, Z) represent the solutions in the phase space. We first present the closed-form solution to the nonlinear equation d2 X/d?2+ (X2/2)X = 0, ? is a non-dimensional time, which was never documented in the literature. As the solution is oscillatory (wave-like) and the nonlinear term (X2) is associated with the nonlinear feedback loop, it is suggested that the nonlinear feedback loop may act as a restoring force. We then show that the competing impact of nonlinear restoring force and linear (heating) force determines the partitions of the averaged available potential energy from Y and Z modes, respectively, denoted as APEY and APEZ. Based on the energy analysis, an energy cycle with four different regimes is identified with the following four points: A(X, Y) = (0,0), B = (Xt, Yt), C = (Xm, Ym), and D = (Xt, -Yt). Point A is a saddle point. The initial perturbation (X, Y, Z) = (0, 1, 0) gives (Xt, Yt) = ( 2?r , r) and (Xm, Ym) = (2 ?r , 0). ? is the Prandtl number, and r is the normalized Rayleigh number. The energy cycle starts at (near) point A, A+ = (0, 0+) to be specific, goes through B, C, and D, and returns back to A, i.e., A- = (0,0-). From point A to point B, denoted as Leg A-B, where the linear (heating) force dominates, the solution X grows gradually with { KE↑, APEY↓, APEZ↓}. KE is the averaged kinetic energy. We use the upper arrow (↑) and down arrow (↓) to indicate an increase and decrease, respectively. In Leg B-C (or C-D) where nonlinear restoring force becomes dominant, the solution X increases (or decreases) rapidly with KE↑, APEY↑, APEZ↓ (or KE↓, APEY↓, APEZ↑). In Leg D-A, the solution X decreases slowly with {KE↓, APEY↑, APEZ↑ }. As point A is a saddle point, the aforementioned cycle may be only half of a "big" cycle, displaying the wing pattern of a glasswinged butterfly, and the other half cycle is antisymmetric with respect to the origin, namely B = (-Xt, -Yt), C = (-Xm, 0), and D = (-Xt, Yt).

Shen, B.-W.

2014-04-01

294

Primary energy implications of end-use energy efficiency measures in district heated buildings  

Microsoft Academic Search

In this study we explore the effects of end-use energy efficiency measures on different district heat production systems with combined heat and power (CHP) plants for base load production and heat-only boilers for peak and medium load productions. We model four minimum cost district heat production systems based on four environmental taxation scenarios, plus a reference district heat system used

L. Gustavsson; A. Dodoo; N. L. Truong; I. Danielski

2011-01-01

295

RENEWABLE ENERGY AND THE PROCESS OF THE PRIMARY ENERGY SOURCE CHOICE  

Microsoft Academic Search

The paper deals with the most important technical, economic and legislative aspects of the integration of renewable energy sources into conventional power systems. Above all, it describes the specific situation in the power industry in new EU member states, but most of the conclusions are applicable generally. In the first part of the paper the need for the development of

ZDENEK ANDRLIK

296

Reduction of Thermal Energy Loss in Cyclic Operation of Refrigeration Cycle  

NASA Astrophysics Data System (ADS)

Investigation of thermal energy loss in cyclic operation of refrigeration cycle in a refrigerator-freezer were made. The energy loss was found to consist of three parts ; hot gas-refrigerant entering loss, cooling lag loss, and evaporator superheat loss. Hot gas-refrigerant entering loss is occured when high temperature gaseous refrigerant in a condenser flows into an evaporator to heat up the refrigerant in it. Main results are as follows ; 1) Hot gas-refrigerant entering loss, which was the most dominant, was found to be from 7.6 to 12.3% (for reciprocationg compressor) and from 11.9 to 17.4% (for rotary compressor) of the cooling load, respectively. 2) The thermal energy loss was confirmed to be able to be reduced when hot gas-refrigerant was restricted to flow in the evaporator with control valves. It follows to reduce electrical power consumption by 10 and 15%, in the case of reciprocating compressor and of rotary compressor, respectively. 3) Cycle frequency was made to be optimized theoretically and experimentally in the case of with and without valves.

Gommori, Masahiko; Kogure, Hiroshi; Hara, Toshitsugu

297

Experimental Performance Analysis of Supercritical CO2 Thermodynamic Cycle Powered by Solar Energy  

NASA Astrophysics Data System (ADS)

The interests in using carbon dioxide as working fluid increase since the Montreal and Kyoto Protocols were made. In this paper, a complete effort was made to study the performance of CO2 Rankine cycle powered by solar energy experimentally. The system utilizes evacuated solar collectors to convert CO2 into high-temperature supercritical state, used to produce electrical energy and thermal energy, which could be used for air conditioning and hot water supply and so on. The system performances were tested not only in summer, but also in winter; not only in sunny day, but also in cloudy day. The interest of the paper is the solar collector efficiency, because the absorbed heat quantity in the collector can be utilized for power generation and heat supply and other useful outputs. The results show that annually-averaged solar collector efficiency was measured at about 60.4%. The study shows the potential of the application of the solar powered CO2 cycle as a distributed power/heat generation system.

Zhang, X. R.; Yamaguchi, H.; Fujima, K.; Enomoto, M.; Sawada, N.

2006-05-01

298

Earth Observations of the Water and Energy Cycle and the GEWEX Regional Hydroclimate Projects  

NASA Astrophysics Data System (ADS)

In order to predict and manage changes in our environment it is necessary to make accurate observations of the energy and water cycle at various scales. Changes will have direct impacts on our natural and social environment e.g. for our water resources. Within GEWEX, the Global Energy and Water Cycle Experiment of the World Climate Research Programme (WCRP), the global energy and water cycle is a main focus of attention. Changes at the global scale will have consequences at the regional scale and vice versa. To better discern the various processes over the entire range of spatial and temporal scales the Regional Hydroclimate Projects (RHP's) are established as the part of the GEWEX Hydroclimatology Panel that links the regional observations and process understanding to the global scale. This is done through exchange of observations, data, modeling, transferability studies etc. In this presentation an overview is given of the various RHP's, the reasons for their establishment and how they are likely to evolve in the future. Each of the RHP's is a collection of individual researchers, research institutes, academia and national agencies which have a common goal related to our environment and in which association with GEWEX helps to reach that goal. In the next few years the emphasis will be placed on stronger collaboration between the various RHP's as well as the intercomparison and evaluation of the GEWEX global datasets with the regional data sets. Crucial to success in this endeavor is the linkage between in-situ observations, modeling data and earth observational data.

Benedict, S.; van Oevelen, P. J.

2012-12-01

299

Global Change Research Related in the Earth's Energy and Hydrologic Cycle  

NASA Technical Reports Server (NTRS)

The mission of the Global Change Research Related to the Earth's Energy and Hydrologic Cycle is to enhance the scientific knowledge and educational benefits obtained from NASA's Earth Science Enterprise and the U.S. Global Change Research Program, University of Alabama in Huntsville (UAH). This paper presents the final technical report on this collaborative effort. Various appendices include: A) Staff Travel Activities years one through three; B) Publications and Presentations years one through three; C) Education Activities; D) Students year one through three; E) Seminars year one through three; and F) Center for Applied Optics Projects.

Berry, Linda R.

2002-01-01

300

The seasonal CO2 cycle on Mars - An application of an energy balance climate model  

NASA Technical Reports Server (NTRS)

Energy balance climate models of the Budyko-Sellers variety are applied to the carbon-dioxide cycle on Mars. Recent data available from the Viking mission, in particular the seasonal pressure variations measured by Viking landers, are used to constrain the models. No set of parameters was found for which a one-dimensional model parameterized in terms of ground temperature gave an adequate fit to the observed pressure variations. A modified, two-dimensional model including the effects of dust storms and the polar hood reasonably reproduces the pressure curve, however. The implications of these results for Martian climate changes are discussed.

James, P. B.; North, G. R.

1982-01-01

301

Quantifying power output during cycling through measuring strain energy in a bicycle frame.  

PubMed

Quantifying power output is becoming more popular in training and competition for cycling. This popularity comes from the fact that power is a direct means of measuring intensity, which is considered by many to be the most important variable in a successful training program. Although other methods are available for measuring power output, there is no frame that is available that uses strain to quantify power output. Using a frame may prove superior to currently available products. Additionally, strain may prove useful for cycling technique analysis, another critical factor for success. In this study, a cyclocross bicycle frame was instrumented with six strain gages to determine if strain energy in the frame correlates with power output. For pilot data, an 85 kg subject rode the bike on rollers with a fork stand at 250 watts and a cadence of 90 rpm. Although more data needs to be collected and analyzed to find a correlation with power output, initial pilot data shows that the strain in the frame is cyclic in nature when pedaling and has a corresponding frequency with the pedaling cadence. It is hypothesized that the strain in the frame will have a high correlation with power output. While this application is specific to cycling, correlating strain to power output may prove useful in other applications. PMID:12085643

Watt, Jonathan B; Reiser, Raoul F; Peterson, M L; Walrath, D E

2002-01-01

302

Thermodynamic systems analysis of open-cycle Ocean Thermal Energy Conversion (OTEC)  

NASA Astrophysics Data System (ADS)

This report describes an updated thermal-hydraulic systems analysis program called OTECSYS that studies the integrated performance of an open-cycle ocean thermal energy conversion (OTEC) plant, specifically, the effects of component performance, design parameters, and site specific resource data on the total system performance and plant size. OTECSYS can size the various open-cycle power cycle and hydraulic components. Models for the evaporator, mist eliminator, turbine-generator diffuser, direct-contact condenser, exhaust compressors, seawater pumps, and seawater piping are included, as are evaluations of the pressure drops associated with the intercomponent connections. It can also determine the required steam, cold seawater, and warm seawater flow rates. OTECSYS uses an approach similar to earlier work and integrates the most up-to-date developments in component performance and configuration. The program format allows the user to examine subsystem concepts not currently included by creating new component models. It will be useful to the OTEC plant designer who wants to quantify the design point sizing, performance, and power production using site-specific resource data. Detailed design trade-offs are easily evaluated, and several examples of these types of investigations are presented using plant size and power as criteria.

Parsons, B. K.; Bharathan, D.; Althof, J. A.

1985-09-01

303

Vacuum thermal cycle life testing of high temperature thermal energy storage  

NASA Astrophysics Data System (ADS)

An experimental program to investigate the corrosion compatibility of the high temperature thermal energy storage (TES) salts with Inconel-617 container was initiated at the Thermal Laboratory of the Wright Research and Development Center (WRDC) in 1985. Three fluoride eutectic mixtures: LiF-MgF2-KF, LiF-MgF2-NaF, and LiF-MgF2 having melting points in the neighborhood of 1000 K and heats of fusion above 750 kJ/kg were chosen. High purity analytical grade component salts were processed in oxygen and moisture-free inert atmosphere, and melted in situ in the Inconel-617 containers. The containers were sealed by electron beam-welding of the end caps thereby evacuating the void volume. The TES capsules thus formed were placed in a tubular vacuum furnace for continuous thermal cycle life testing by cycling them ±100 K from the eutectic temperature every 2 hours. The capsules have successfully undergone 40,000 hours and 10,000 cycles of testing as of April 1990 and continuing on the test. This is believed to be the longest record available on the TES corrosion compatibility data. The present results clearly indicate that careful processing and proper welding are key factors in obtaining a longlife TES salt-containment system.

Ponnappan, Rengasamy; Beam, Jerry E.

1991-01-01

304

Vacuum thermal cycle life testing of high temperature thermal energy storage  

SciTech Connect

An experimental program to investigate the corrosion compatibility of the high temperature thermal energy storage (TES) salts with Inconel-617 container was initiated at the Thermal Laboratory of the Wright Research and Development Center (WRDC) in 1985. Three fluoride eutectic mixtures: LiF-MgF{sub 2}-KF, LiF-MgF{sub 2}-NaF, and LiF-MgF{sub 2} having melting points in the neighborhood of 1000 K and heats of fusion above 750 kJ/kg were chosen. High purity analytical grade component salts were processed in oxygen and moisture-free inert atmosphere, and melted {ital in} {ital situ} in the Inconel-617 containers. The containers were sealed by electron beam-welding of the end caps thereby evacuating the void volume. The TES capsules thus formed were placed in a tubular vacuum furnace for continuous thermal cycle life testing by cycling them {plus minus}100 K from the eutectic temperature every 2 hours. The capsules have successfully undergone 40,000 hours and 10,000 cycles of testing as of April 1990 and continuing on the test. This is believed to be the longest record available on the TES corrosion compatibility data. The present results clearly indicate that careful processing and proper welding are key factors in obtaining a longlife TES salt-containment system.

Ponnappan, R. (Universal Energy Systems, Inc., 4401 Dayton-Xenia Road, Dayton, Ohio 45432-1894 (USA)); Beam, J.E. (Aero Propulsion and Power Laboratory, Wright Research and Development Center, Wright-Patterson AFB, Ohio 45433-6563 (USA))

1991-01-01

305

Global Change Research Related to the Earth's Energy and Hydrologic Cycle  

NASA Technical Reports Server (NTRS)

The Institute for Global Change Research and Education (IGCRE) is a joint initiative of the Universities Space Research Association (USRA) and the University of Alabama in Huntsville (UAH) for coordinating and facilitating research and education relevant to global environmental change. Created in 1992 with primary support from the National Aeronautics and Space Administration (NASA), IGCRE fosters participation by university, private sector and government scientists who seek to develop long-term collaborative research in global change science, focusing on the role of water and energy in the Earth's atmosphere and physical climate system. IGCRE is also chartered to address educational needs of Earth system and global change science, including the preparation of future scientists and training of primary and secondary education teachers.

1998-01-01

306

Rock Cycle: Cycling  

NSDL National Science Digital Library

This Science Object is the third of four Science Objects in the Rocks SciPack. It explores the variables that contribute to rock transformation and the continuous processes of rock formation that constitute the rock cycle. The rock cycle provides an example of the transfer of energy and mass in the Earth system. Earth is a closed system containing essentially a fixed amount of each element. Movement of matter is driven by the Earth's internal and external sources of energy, and is often accompanied by changes in the physical and chemical properties of the matter. Minerals are made, dissolved, and remade--on the Earth's surface, in the oceans, and in the hot, high-pressure layers beneath the crust. The total amount of material stays the same as its forms change. Learning Outcomes:? Recognize the formation and transformation processes as part of a continuing cycle.? Identify that while the form and location of different rocks change over time, the amount of material and the distribution among the elements remains constant.? Explain the different processes or paths that each type of rock may take in the rock cycle.

National Science Teachers Association (NSTA)

2006-11-01

307

Estimation of vertical sea level muon energy spectra from the latest primary cosmic ray elemental spectra  

NASA Astrophysics Data System (ADS)

The directly measured elemental spectra of primary cosmic rays obtained from Webber et al., Seo et al., Menn et al., Ryan et al. and experiments like JACEE, CRN, SOKOL, RICH on P, He, CNO, Ne-S and Fe have been considered to estimate the vertical sea level muon energy spectra. The primary elemental energy spectra of P, He, CNO, Ne-S and Fe available from the different experimental data duly fitted by power law are given by Np(E)dE = 1.2216E-2.68 dE [cm2 .s.sr.GeV/n]-1 NHe(E)dE = 0.0424E-2.59 dE [cm2 .s.sr.GeV/n]-1 NCNO(E)dE = 0.0026E-2.57 dE[cm2 .s.sr.GeV/n]-1 NNe-S(E)dE = 0.00066E-2.57 dE [cm2 .s.sr.GeV/n]-1 NF e(E)dE = 0.0056E-2.55 dE [cm2 .s.sr.GeV/n]-1 Using the conventional superposition model the all nucleon primary cosmic ray spectrum has been derived which is of the form N(E)dE = 1.42E-2.66 dE [cm2 .s.sr.GeV/n]-1 We have considered all these spectra separately as parents of the secondary mesons and finallty the sea level muon fluxes at 00 from each species have been derived. To evaluate the meson spectra which are the initial air shower interaction products initiated by the primary nucleon air collisions, the hadronic energy moments have been calculated from the CERN LEBCEHS data for pp collisions and FNAL data for ?p collisions. Pion production by secondary pions have been taken into account and the final total muon spectrum has been derived from pp rightarrow?± x, pp ? K± x, ?p ? ?± x channels. The Z-factors have been corrected for p-air collisions. We have adopted the constant values of ?p-air and ??-air crosssections which are 273 mb and 213 mb, respectively. The adopted inelastic cross-sections for pp and ?p interactions are 35 mb and 22 mb, respectively. The Q-G plasma correction of Z-factors have also been incorporated in the final form. The solution to the standard differential equation for mesons is considered for muon flux estimation from Ngenerations of the parent mesons. By this formulation vertical muon spectra from each element along with the total primary nucleon spectrum have been derived. We wanted to observe the different shape of the muon spectra evaluated from different elemental spectra and to make a comparative study of that. In this energy range (102 - 104 ) GeV we have observed that the majority of the total muon flux is coming from the proton spectra. The contribution from the other elemental spectra to the total muon flux is not at all comparable with that of proton spectra.

Mitra, M.; Molla, N. H.; Bhattacharyya, D. P.

308

Annual cycle of the global-mean energy budget in a mechanistic middle atmosphere GCM  

NASA Astrophysics Data System (ADS)

A new mechanistic climate model from the surface to the lower thermosphere is presented. The model is based on a standard spectral dynamical core and includes an idealized radiation scheme with continuous computation of energy fluxes. The surface energy budget is fully taken into account by means of a slap ocean with prescribed lateral oceanic heat-flux convergence. The moisture budget is based on a new transport scheme and simple parameterizations of condensation and convection. Subgrid-scale parameterizations include gravity waves and turbulent diffusion. Each parameterized process is formulated in an energy conserving fashion such that the resulting numerical error of the net radiation at the top of the atmosphere (RTOA) is about 0.2 W/m/m. The model shows a pronounced annual cycle of the RTOA of several W/m/m, with the minimum occurring in late NH winter. On a seasonal timescale this variation is synchronous with an equally strong imbalance at the surface. The annual cycle of the RTOA results from the hemispheric differences in the distribution of land and ocean surfaces, which are characterized by different heat capacities and albedos. While the absorbed solar radiation (ASR) is dominated by a semi-annual component associated with maximum absorption at the surface during the equinoxes, the global-mean surface temperature is governed by an annual component with a minimum during late NH winter. The reason is a smaller surface heat capacity in the NH, giving rise to global-mean cooling particularly during early NH winter. The annual cycle in the surface temperature then implies a corresponding behavior in the outgoing long-wave radiation (OLR), which gives the main contribution to the annual component of the RTOA. These mechanistic model results are supported by existing observational analyses. Analysing the global-mean energy budget as a function of height, the residual circulation is found to account for a downward dynamical energy flux from the stratosphere into the troposphere of about 1 W/m/m, which is consistently balanced in the model by a net upward radiation flux between about 300 and 10 hPa. The implications of this study are that 1) an imbalance in the RTOA may contain significant contributions from natural oceanic variability and 2) the dynamical energy flux from the middle into the lower atmosphere requires to include a realistic stratosphere in climate models.

Becker, Erich; Knoepfel, Rahel

2014-05-01

309

Life cycle assessment of thermal Waste-to-Energy technologies: Review and recommendations.  

PubMed

Life cycle assessment (LCA) has been used extensively within the recent decade to evaluate the environmental performance of thermal Waste-to-Energy (WtE) technologies: incineration, co-combustion, pyrolysis and gasification. A critical review was carried out involving 250 individual case-studies published in 136 peer-reviewed journal articles within 1995 and 2013. The studies were evaluated with respect to critical aspects such as: (i) goal and scope definitions (e.g. functional units, system boundaries, temporal and geographic scopes), (ii) detailed technology parameters (e.g. related to waste composition, technology, gas cleaning, energy recovery, residue management, and inventory data), and (iii) modeling principles (e.g. energy/mass calculation principles, energy substitution, inclusion of capital goods and uncertainty evaluation). Very few of the published studies provided full and transparent descriptions of all these aspects, in many cases preventing an evaluation of the validity of results, and limiting applicability of data and results in other contexts. The review clearly suggests that the quality of LCA studies of WtE technologies and systems including energy recovery can be significantly improved. Based on the review, a detailed overview of assumptions and modeling choices in existing literature is provided in conjunction with practical recommendations for state-of-the-art LCA of Waste-to-Energy. PMID:25052337

Astrup, Thomas Fruergaard; Tonini, Davide; Turconi, Roberto; Boldrin, Alessio

2015-03-01

310

Energy harvesting based on piezoelectric Ericsson cycles in a piezoceramic material  

NASA Astrophysics Data System (ADS)

The possibility of recycling ambient energies with electric generators instead of using batteries with limited life spans has stimulated important research efforts over the past years. The integration of such generators into mainly autonomous low-power systems, for various industrial or domestic applications is envisioned. In particular, the present work deals with energy harvesting from mechanical vibrations. It is shown here that direct piezoelectric energy harvesting (short circuiting on an adapted resistance, for example) leads to relatively weak energy levels that are insufficient for an industrial development. By coupling an electric field and mechanical excitation on Ericsson-based cycles, the amplitude of the harvested energy can be highly increased, and can reach a maximum close to 100 times its initial value. To obtain such a gain, one needs to employ high electrical field levels (high amplitude, high frequency), which induce a non-linearity through the piezoceramic. A special dynamic hysteresis model has been developed to correctly take into account the material properties, and to provide a real estimation of the harvested energy. A large number of theoretical predictions and experimental results have been compared and are discussed herein, in order to validate the proposed solution.

Zhang, B.; Ducharne, B.; Guyomar, D.; Sebald, G.

2013-09-01

311

Life cycle energy and greenhouse gas emissions of nuclear energy: A review  

Microsoft Academic Search

The increased urgency of dealing with mitigation of the looming climate change has sparked renewed interest in the nuclear energy option. There exists a substantial stream of research on the amount of embodied energy and greenhouse gas emissions associated with nuclear generated electricity. While conventional fossil fuelled power plants cause emissions almost exclusively from the plant site, the majority of

Manfred Lenzen

2008-01-01

312

Cycle-accurate Energy Measurement and High-Level Energy Characterization of FPGAs  

Microsoft Academic Search

Field programmable gate arrays (FPGAs) play many important roles, ranging from small glue logic replacement to System-on- Chip designs. Nevertheless, FPGA vendors can not accurately specify the energy consumption information of their products on the device data sheets because the energy consumption of FPGAs is strongly dependent on target circuit including resource utilization, logic partitioning, mapping, placement and route. While

Hyung Gyu Lee; Sungyuep Nam; Naehyuck Chang

2003-01-01

313

Operating Conditions of a Three-stage Combined Power Cycle using Cold Energy for Maximizing Exergetic Efficiency  

NASA Astrophysics Data System (ADS)

Waste heat utilization is a fundamental approach to end-use energy savings. Medium or low temperature waste heat is not usable unless its temperature level matches the demand. From this standpoint, power generation from medium or low temperature waste heat is beneficial because it improves the availability of the energy by converting waste heat into electricity or mechanical work. Conventional waste heat driven power generation cycles, such as the Kalina cycle, attain relatively low thermal efficiencies because of the low exergy in medium or low temperature heat. This paper proposes a three-stage combined power cycle using cold energy for power generation from medium temperature (?200°C)waste heat. The system consists of an ammonia-water Rankine cycle, an ethane-propane Rankine cycle and a liquefied natural gas direct expansion cycle. A cycle simulation of the system is executed, and the operating conditions where the exergetic efficiency is maximized are presented in this article. It is found that the exergetic efficiency reaches 31% under these operating conditions.

Miyazaki, Takahiko; Akisawa, Atsushi; Kashiwagi, Takao

314

Shifting primary energy source and NOx emission location with plug-in hybrid vehicles  

NASA Astrophysics Data System (ADS)

Plug-in hybrid vehicles (PHEVs) present an interesting technological opportunity for using non-fossil primary energy in light duty passenger vehicles, with the associated potential for reducing air pollutant and greenhouse gas emissions, to the extent that the electric power grid is fed by non-fossil sources. This perspective, accompanying the article by Thompson et al (2011) in this issue, will touch on two other studies that are directly related: the Argonne study (Elgowainy et al 2010) and a PhD thesis from Utrecht (van Vliet 2010). Thompson et al (2011) have examined air quality effects in a case where the grid is predominantly fossil fed. They estimate a reduction of 7.42 tons/day of NOx from motor vehicles as a result of substituting electric VMTs for 20% of the light duty gasoline vehicle miles traveled. To estimate the impact of this reduction on air quality they also consider the increases in NOx emissions due to the increased load on electricity generating units. The NOx emission increases are estimated as 4.0, 5.5 and 6.3 tons for the Convenience, Battery and Night charging scenarios respectively. The net reductions are thus in the 1.1-3.4 tons/day range. The air quality modelling results presented show that the air quality impact from a ground-level ozone perspective is favorable overall, and while the effect is stronger in some localities, the difference between the three scenarios is small. This is quite significant and suggests that localization of the NOx emissions to point sources has a more pronounced effect than the absolute reductions achieved. Furthermore it demonstrates that localization of NOx emissions to electricity generating units by using PHEVs in vehicle traffic has beneficial effects for air quality not only by minimizing direct human exposure to motor vehicle emissions, but also due to reduced exposure to secondary pollutants (i.e. ozone). In an electric power grid with a smaller share of fossil fired generating units, the beneficial effects would be more pronounced. In such a case, it would also be possible to realize reductions in greenhouse gas emissions. The significance of the electric power generation mix for plug-in hybrid vehicles and battery electric vehicles is a key aspect of Argonne National Laboratories' well-to-wheel study which focuses on petroleum use and greenhouse gas emissions (Elgowainy et al 2010). The study evaluates possible reductions in petroleum use and GHG emissions in the electric power systems in four major regions of the United States as well as the US average generation mix, using Argonne's GREET life-cycle analysis model. Two PHEV designs are investigated through a Powertrain System Analysis Toolkit (PSAT) model: the power-split configuration (e.g. the current Toyota Prius model with Hymotion conversion), and a future series configuration where the engine powers a generator, which charges a battery that is used by the electric motor to propel the vehicle. Since the petroleum share is small in the electricity generation mix for most regions in the United States, it is possible to achieve significant reductions in petroleum use by PHEVs. However, GHG reduction is another story. In one of the cases in the study, PHEVs in the charge depleting mode and recharging from a mix with a large share of coal generation (e.g., Illinois marginal mix) produce GHG emissions comparable to those of baseline gasoline internal combustion engine vehicles (with a range from -15% to +10%) but significantly higher than those of gasoline hybrid electric vehicles (with a range from +20% to +60%). In what is called the unconstrained charging scenario where investments in new generation capacity with high efficiency and low carbon intensity are envisaged, it becomes possible to achieve significant reductions in both petroleum use and GHG emissions. In a PhD dissertation at Utrecht University, van Vliet (2010) presents a comprehensive analysis of alternatives to gasoline and diesel by looking at various fuel and vehicle technologies. Three chapters are of particular interest from the pers

Karman, Deniz

2011-06-01

315

Life cycle inventory of recycling portable nickel–cadmium batteries  

Microsoft Academic Search

In this study, the environmental impact of recycling portable nickel–cadmium (NiCd) batteries in Sweden is evaluated. A life cycle assessment approach was used to identify life cycle activities with significant impact, the influence of different recycling rates and different time boundaries for emissions of landfilled metals. Excluding the user phase of the battery, 65% of the primary energy is used

Carl Johan Rydh; Magnus Karlström

2002-01-01

316

LIFE CYCLE DESIGN OF AMORPHOUS SILICON PHOTOVOLTAIC MODULES  

EPA Science Inventory

The life cycle design framework was applied to photovoltaic module design. The primary objective of this project was to develop and evaluate design metrics for assessing and guiding the Improvement of PV product systems. Two metrics were used to assess life cycle energy perform...

317

Life cycle assessment modelling of waste-to-energy incineration in Spain and Portugal.  

PubMed

In recent years, waste management systems have been evaluated using a life cycle assessment (LCA) approach. A main shortcoming of prior studies was the focus on a mixture of waste with different characteristics. The estimation of emissions and consumptions associated with each waste fraction in these studies presented allocation problems. Waste-to-energy (WTE) incineration is a clear example in which municipal solid waste (MSW), comprising many types of materials, is processed to produce several outputs. This paper investigates an approach to better understand incineration processes in Spain and Portugal by applying a multi-input/output allocation model. The application of this model enabled predictions of WTE inputs and outputs, including the consumption of ancillary materials and combustibles, air emissions, solid wastes, and the energy produced during the combustion of each waste fraction. PMID:24951550

Margallo, M; Aldaco, R; Irabien, A; Carrillo, V; Fischer, M; Bala, A; Fullana, P

2014-06-18

318

Controlling and maximizing effective thermal properties by manipulating transient behaviors during energy-system cycles  

E-print Network

Transient processes generally constitute part of energy-system cycles. If skillfully manipulated, they actually are capable of assisting systems to behave beneficially to suit designers' needs. In the present study, behaviors related to both thermal conductivities ($\\kappa$) and heat capacities ($c_{v}$) are analyzed. Along with solutions of the temperature and the flow velocity obtained by means of theories and simulations, three findings are reported herein: $(1)$ effective $\\kappa$ and effective $c_{v}$ can be controlled to vary from their intrinsic material-property values to a few orders of magnitude larger; $(2)$ a parameter, tentatively named as "nonlinear thermal bias", is identified and can be used as a criterion in estimating energies transferred into the system during heating processes and effective operating ranges of system temperatures; $(3)$ When a body of water, such as the immense ocean, is subject to the boundary condition of cold bottom and hot top, it may be feasible to manipulate transien...

Gao, Z J; Merlitz, H; Pagni, P J; Chen, Z

2014-01-01

319

Systems analysis techniques for annual cycle thermal energy storage solar systems  

SciTech Connect

Community-scale annual cycle thermal energy storage (ACTES) solar systems are promising options for building heat and cooling. A variety of approaches are feasible in modeling ACTES solar systems. The key parameter in such efforts, average collector efficiency, is first examined, followed by several approaches for simple and effective modeling. Methods are also examined for modeling building loads for structures based on both conventional and passive architectural designs. Two simulation models for sizing solar heating systems with annual storage are presented next. Validation is presented by comparison with the results of a study of seasonal storage systems based on SOLANSIM, an hour-by-hour simulation. These models are presently being used to examine the economic trade-off between collector field area and storage capacity. Finally, programs in the US Department of Energy directed toward developing either other system components such as improved tanks and solar ponds or design tools for ACTES solar systems are examined.

Baylin, F.; Sillman, S.

1980-07-01

320

Study on fission blanket fuel cycling of a fusion-fission hybrid energy generation system  

NASA Astrophysics Data System (ADS)

This paper presents a preliminary study on neutron physics characteristics of a light water cooled fission blanket for a new type subcritical fusion-fission hybrid reactor aiming at electric power generation with low technical limits of fission fuel. The major objective is to study the fission fuel cycling performance in the blanket, which may possess significant impacts on the feasibility of the new concept of fusion-fission hybrid reactor with a high energy gain (M) and tritium breeding ratio (TBR). The COUPLE2 code developed by the Institute of Nuclear and New Energy Technology of Tsinghua University is employed to simulate the neutronic behaviour in the blanket. COUPLE2 combines the particle transport code MCNPX with the fuel depletion code ORIGEN2. The code calculation results show that soft neutron spectrum can yield M > 20 while maintaining TBR >1.15 and the conversion ratio of fissile materials CR > 1 in a reasonably long refuelling cycle (>five years). The preliminary results also indicate that it is rather promising to design a high-performance light water cooled fission blanket of fusion-fission hybrid reactor for electric power generation by directly loading natural or depleted uranium if an ITER-scale tokamak fusion neutron source is achievable.

Zhou, Z.; Yang, Y.; Xu, H.

2011-10-01

321

Innovative turbine concepts for open-cycle OTEC (Ocean Thermal Energy Conversion)  

NASA Astrophysics Data System (ADS)

The results are summarized of preliminary studies conducted to identify and evaluate three innovative concepts for an open cycle ocean thermal energy conversion (OTEC) steam turbine that could significantly reduce the cost of OTEC electrical power plants. The three concepts are: (1) a crossflow turbine, (2) a vertical axis, axial flow turbine, and (3) a double flow, radial inflow turbine with mixed flow blading. In all cases, the innovation involves the use of lightweight, composite plastic blading and a physical geometry that facilitates efficient fluid flow to and from the other major system components and reduces the structural requirements for both the turbine or the system vacuum enclosure, or both. The performance, mechanical design, and cost of each of the concepts are developed to varying degrees but in sufficient detail to show that the potential exists for cost reductions to the goals established in the U.S. Department of Energy's planning documents. Specifically, results showed that an axial turbine operating with 33 percent higher steam throughput and 7 percent lower efficiency than the most efficient configuration provides the most cost effective open-cycle OTEC system. The vacuum enclosure can be significantly modified to reduce costs by establishing better interfaces with the system.

1989-12-01

322

Extent of partial ice cover due to carbon cycle feedback in a zonal energy balance model Hydrology and Earth System Sciences, 7(2), 213219 (2003) EGU  

E-print Network

Extent of partial ice cover due to carbon cycle feedback in a zonal energy balance model 213 for corresponding author: chg@ceh.ac.uk Abstract A global carbon cycle is introduced into a zonally averaged energy, it is found that inclusion of a closed carbon cycle reduces the range of insolation over which stable partial

Boyer, Edmond

323

Ocean Thermal Energy Conversion Life Cycle Cost Assessment, Final Technical Report, 30 May 2012  

SciTech Connect

The Ocean Thermal Energy Conversion (OTEC) Life Cycle Cost Assessment (OLCCA) is a study performed by members of the Lockheed Martin (LM) OTEC Team under funding from the Department of Energy (DOE), Award No. DE-EE0002663, dated 01/01/2010. OLCCA objectives are to estimate procurement, operations and maintenance, and overhaul costs for two types of OTEC plants: -Plants moored to the sea floor where the electricity produced by the OTEC plant is directly connected to the grid ashore via a marine power cable (Grid Connected OTEC plants) -Open-ocean grazing OTEC plant-ships producing an energy carrier that is transported to designated ports (Energy Carrier OTEC plants) Costs are developed using the concept of levelized cost of energy established by DOE for use in comparing electricity costs from various generating systems. One area of system costs that had not been developed in detail prior to this analysis was the operations and sustainment (O&S) cost for both types of OTEC plants. Procurement costs, generally referred to as capital expense and O&S costs (operations and maintenance (O&M) costs plus overhaul and replacement costs), are assessed over the 30 year operational life of the plants and an annual annuity calculated to achieve a levelized cost (constant across entire plant life). Dividing this levelized cost by the average annual energy production results in a levelized cost of electricity, or LCOE, for the OTEC plants. Technical and production efficiency enhancements that could result in a lower value of the OTEC LCOE were also explored. The thermal OTEC resource for Oahu, Hawai�¢����i and projected build out plan were developed. The estimate of the OTEC resource and LCOE values for the planned OTEC systems enable this information to be displayed as energy supplied versus levelized cost of the supplied energy; this curve is referred to as an Energy Supply Curve. The Oahu Energy Supply Curve represents initial OTEC deployment starting in 2018 and demonstrates the predicted economies of scale as technology and efficiency improvements are realized and larger more economical plants deployed. Utilizing global high resolution OTEC resource assessment from the Ocean Thermal Extractable Energy Visualization (OTEEV) project (an independent DOE project), Global Energy Supply Curves were generated for Grid Connected and Energy Carrier OTEC plants deployed in 2045 when the predicted technology and efficiencies improvements are fully realized. The Global Energy Supply Curves present the LCOE versus capacity in ascending order with the richest, lowest cost resource locations being harvested first. These curves demonstrate the vast ocean thermal resource and potential OTEC capacity that can be harvested with little change in LCOE.

Martel, Laura; Smith, Paul; Rizea, Steven; Van Ryzin, Joe; Morgan, Charles; Noland, Gary; Pavlosky, Rick; Thomas, Michael

2012-06-30

324

Thermal energy storage for integrated gasification combined-cycle power plants  

SciTech Connect

There are increasingly strong indications that the United States will face widespread electrical power generating capacity constraints in the 1990s; most regions of the country could experience capacity shortages by the year 2000. The demand for new generating capacity occurs at a time when there is increasing emphasis on environmental concerns. The integrated gasification combined-cycle (IGCC) power plant is an example of an advanced coal-fired technology that will soon be commercially available. The IGCC concept has proved to be efficient and cost-effective while meeting all current environmental regulations on emissions; however, the operating characteristics of the IGCC system have limited it to base load applications. The integration of thermal energy storage (TES) into an IGCC plant would allow it to meet cyclic loads while avoiding undesirable operating characteristics such as poor turn-down capability, impaired part-load performance, and long startup times. In an IGCC plant with TES, a continuously operated gasifier supplies medium-Btu fuel gas to a continuously operated gas turbine. The thermal energy from the fuel gas coolers and the gas turbine exhaust is stored as sensible heat in molten nitrate salt; heat is extracted during peak demand periods to produce electric power in a Rankine steam power cycle. The study documented in this report was conducted by Pacific Northwest Laboratory (PNL) and consists of a review of the technical and economic feasibility of using TES in an IGCC power plant to produce intermediate and peak load power. The study was done for the US Department of Energy's (DOE) Office of Energy Storage and Distribution. 11 refs., 5 figs., 18 tabs.

Drost, M.K.; Antoniak, Z.I.; Brown, D.R.; Somasundaram, S.

1990-07-01

325

An RF energy harvesting power management circuit for appropriate duty-cycled operation  

NASA Astrophysics Data System (ADS)

In this study, we present an RF energy harvesting power management unit (PMU) for battery-less wireless sensor devices (WSDs). The proposed PMU realizes a duty-cycled operation that is divided into the energy charging time and discharging time. The proposed PMU detects two types of timing, thus, the appropriate timing for the activation can be recognized. The activation of WSDs at the proper timing leads to energy efficient operation and stable wireless communication. The proposed PMU includes a hysteresis comparator (H-CMP) and an RF signal detector (RF-SD) to detect the timings. The proposed RF-SD can operate without the degradation of charge efficiency by reusing the RF energy harvester (RF-EH) and H-CMP. The PMU fabricated in a 180 nm Si CMOS demonstrated the charge operation using the RF signal at 915 MHz and the two types of timing detection with less than 124 nW in the charge phase. Furthermore, in the active phase, the PMU generates a 0.5 V regulated power supply from the charged energy.

Shirane, Atsushi; Ito, Hiroyuki; Ishihara, Noboru; Masu, Kazuya

2015-04-01

326

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

NASA Astrophysics Data System (ADS)

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.

Waters, Daniel F.; Cadou, Christopher P.

2014-02-01

327

Cell type and transfection reagent-dependent effects on viability, cell content, cell cycle and inflammation of RNAi in human primary mesenchymal cells.  

PubMed

The application of RNA interference (RNAi) has great therapeutic potential for degenerative diseases of cartilaginous tissues by means of fine tuning the phenotype of cells used for regeneration. However, possible non-specific effects of transfection per se might be relevant for future clinical application. In the current study, we selected two synthetic transfection reagents, a cationic lipid-based commercial reagent Lipofectamine RNAiMAX and polyethylenimine (PEI), and two naturally-derived transfection reagents, namely the polysaccharides chitosan (98% deacetylation) and hyaluronic acid (20% amidation), for siRNA delivery into primary mesenchymal cells including nucleus pulposus cells, articular chondrocytes and mesenchymal stem cells (MSCs). Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as an endogenous model gene to evaluate the extent of silencing by 20 nM or 200 nM siRNA at day 3 and day 6 post-transfection. In addition to silencing efficiency, non-specific effects such as cytotoxicity, change in DNA content and differentiation potential of cells were evaluated. Among the four transfection reagents, the commercial liposome-based agent was the most efficient reagent for siRNA delivery at 20 nM siRNA, followed by chitosan. Transfection using cationic liposomes, chitosan and PEI showed some decrease in viability and DNA content to varying degrees that was dependent on the siRNA dose and cell type evaluated, but independent of GAPDH knockdown. Some effects on DNA content were not accompanied by concomitant changes in viability. However, changes in expression of marker genes for cell cycle inhibition or progression, such as p21 and PCNA, could not explain the changes in DNA content. Interestingly, aspecific upregulation of GAPDH activity was found, which was limited to cartilaginous cells. In conclusion, non-specific effects should not be overlooked in the application of RNAi for mesenchymal cell transfection and may need to be overcome for its effective therapeutic application. PMID:24345796

Yang, Hsiao-yin; Vonk, Lucienne A; Licht, Ruud; van Boxtel, Antonetta M G; Bekkers, Joris E J; Kragten, Angela H M; Hein, San; Varghese, Oommen P; Howard, Kenneth A; Öner, F Cumhur; Dhert, Wouter J A; Creemers, Laura B

2014-03-12

328

Life-cycle costing manual for the Federal energy management program: a guide for evaluating the cost effectiveness of energy conservation and renewable energy projects for new and existing Federally owned and leased buildings and facilities. Final report  

Microsoft Academic Search

This manual is a guide to understanding the life-cycle costing method and an aid to calculating the measures required for evaluating energy conservation and renewable energy investments in all Federal buildings. It expands upon life-cycle costing criteria contained in the Program Rules of the Federal Energy Management Program (Subpart A of Part 436, Title 10, US Code of Federal Regulations)

Ruegg

1980-01-01

329

Strengthening of the hydrological cycle in future scenarios: atmospheric energy and water balance perspective  

NASA Astrophysics Data System (ADS)

Future climate scenarios experiencing global warming are expected to strengthen the hydrological cycle during the 21st century (21C). We analyze the strengthening of the global-scale increase in precipitation from the perspective of changes in whole atmospheric water and energy balances. By combining energy and water equations for the whole atmosphere, we obtain constraints for the changes in surface fluxes and partitioning at the surface between sensible and latent components. We investigate the differences in the strengthening of the hydrological cycle in two centennial simulations performed with an Earth system model forced with specified atmospheric concentration pathways. Alongside the Special Report on Emissions Scenario (SRES) A1B, which is a medium-high non-mitigation scenario, we consider a new aggressive-mitigation scenario (E1) with reduced fossil fuel use for energy production aimed at stabilizing global warming below 2 K. Our results show that the mitigation scenario effectively constrains the global warming with a stabilization below 2 K with respect to the 1950-2000 historical period. On the other hand, the E1 precipitation does not follow the temperature field toward a stabilization path but continues to increase over the mitigation period. Quite unexpectedly, the mitigation scenario is shown to strengthen the hydrological cycle even more than SRES A1B till around 2070. We show that this is mostly a consequence of the larger increase in the negative radiative imbalance of atmosphere in E1 compared to A1B. This appears to be primarily related to decreased sulfate aerosol concentration in E1, which considerably reduces atmospheric absorption of solar radiation compared to A1B. The last decades of the 21C show a marked increase in global precipitation in A1B compared to E1, despite the fact that the two scenarios display almost the same overall increase of radiative imbalance with respect to the 20th century. Our results show that radiative cooling is weakly effective in A1B throughout the 21C. Two distinct mechanisms characterize the diverse strengthening of the hydrological cycle in the middle and end- 21C. It is only through a very large perturbation of surface fluxes that A1B achieves a larger increase in global precipitation in the last decades of the 21C. Our energy/water budget analysis shows that this behavior is ultimately due to a bifurcation in the Bowen ratio change between the two scenarios. This work warns that mitigation policies that promote aerosol abatement, may lead to an unexpected stronger intensification of the hydrological cycle and associated changes that may last for decades after global warming is effectively mitigated. On the other hand, it is also suggested that predictable components of the radiative forcing by aerosols may have the potential to effectively contribute to the decadal-scale predictability of changes in the hydrological strength.

Alessandri, A.; Fogli, P. G.; Vichi, M.; Zeng, N.

2012-11-01

330

A Finite Element Model Of Self-Resonating Bimorph Microcantilever For Fast Temperature Cycling In A Pyroelectric Energy Harvester  

SciTech Connect

A self resonating bimorph cantilever structure for fast temperature cycling in a pyroelectric energy harvester has been modeled using a finite element method. The effect of constituting material properties and system parameters on the frequency and magnitude of temperature cycling and the efficiency of energy recycling using the proposed structure has been investigated. Results show that thermal contact conductance and heat source temperature play a key role in dominating the cycling frequency and efficiency of energy recycling. An optimal solution for the most efficient energy scavenging process has been sought by studying the performance trend with different variable parameters such as thermal contact conductance, heat source temperature, device aspect ratio and constituent materials of varying thermal conductivity and expansion coefficients.

Mostafa, Salwa [ORNL; Lavrik, Nickolay V [ORNL; Bannuru, Thirumalesh [ORNL; Rajic, Slobodan [ORNL; Islam, Syed K [ORNL; Datskos, Panos G [ORNL; Hunter, Scott Robert [ORNL

2011-01-01

331

The energy of the ocean thermal resource and the second-law efficiency of idealized ocean thermal energy conversion power cycles  

NASA Astrophysics Data System (ADS)

A formula is developed to compute the maximum amount of work which can be extracted from a given combined mass of warm and cold ocean water (a quantity called the energy of the ocean thermal resources). Second it compares the second-law efficiencies of various proposed ocean thermal energy conversion power cycles to determine which best utilizes the energy of the ocean thermal resource. The second-law efficiencies of the multicomponent working fluid cycle, the Beck cycle, and the open and closed single- and multiple-stage Rankine cycles are compared. These types of OTEC power plants are analyzed in a consistent manner which assumes that all deviations from a plant making use of all the energy (one with a second-law efficiency of 100%) occurs because of irreversible transfer of heat across a finite temperature difference. Conversion of thermal energy to other forms is assumed to occur reversibly. The comparison of second-law efficiencies of various OTEC power cycles shows that the multistage Rankine open cycle with just three stages has the potential of best using the energy of the ocean thermal resource.

Johnson, D. H.

1982-09-01

332

FEASIBILITY OF HYDROGEN PRODUCTION USING LASER INERTIAL FUSION AS THE PRIMARY ENERGY SOURCE  

SciTech Connect

The High Average Power Laser (HAPL) program is developing technology for Laser IFE with the goal of producing electricity from the heat generated by the implosion of deuterium-tritium (DT) targets. Alternatively, the Laser IFE device could be coupled to a hydrogen generation system where the heat would be used as input to a water-splitting process to produce hydrogen and oxygen. The production of hydrogen in addition to electricity would allow fusion energy plants to address a much wider segment of energy needs, including transportation. Water-splitting processes involving direct and hybrid thermochemical cycles and high temperature electrolysis are currently being developed as means to produce hydrogen from high temperature nuclear fission reactors and solar central receivers. This paper explores the feasibility of this concept for integration with a Laser IFE plant, and it looks at potential modifications to make this approach more attractive. Of particular interest are: (1) the determination of the advantages of Laser IFE hydrogen production compared to other hydrogen production concepts, and (2) whether a facility of the size of FTF would be suitable for hydrogen production.

Gorensek, M

2006-11-03

333

Planning for hybrid-cycle OTEC experiments using the HMTSTA test facility at the Natural Energy Laboratory of Hawaii  

NASA Astrophysics Data System (ADS)

The U.S. Department of Energy has built an experimental apparatus for studying the open-cycle Ocean Thermal Energy Conversion (OC-OTEC) system. Experiments using warm and cold seawater are currently underway to validate the performance predictions for an OC-TEC flash evaporator, surface condenser, and direct-contact condenser. The hybrid cycle is another OTEC option that produces both power and desalinated water, it is comparable in capital cost to OC-OTEC, and it eliminates the problems associated with the large steam turbine. Means are presented or modifying the existing apparatus to conduct similar experiments on hybrid-cycle OTEC heat exchangers. These data are required to validate predictive methods of the components and for the system integration that were identified in an earlier study of hybrid-cycle OTEC power plants.

Panchal, C.; Rabas, T.; Genens, L.

334

Life-Cycle Analysis of Energy and Greenhouse Gas Emissions from Anaerobic Biodegradation of Municipal Solid Waste  

Microsoft Academic Search

Energy requirements and greenhouse gas GHG emissions for current landfilling of municipal solid waste MSW was compared to potential biodegradation of MSW in anaerobic digesters AD throughout the United States. A hybrid life-cycle analysis was completed to assess the potential for anaerobic biodegradation of MSW to methane, a valuable energy source. Conversion of MSW to methane in AD would generate

Thomas D. DiStefano

2009-01-01

335

A toolkit for primary HVAC system energy calculation. Part 2: Reciprocating chiller models  

SciTech Connect

This is the second in a series of papers presenting the fundamentals of a new simulation tool kit developed by ASHRAE TC 4.7 The modeling used in this tool kit is oriented toward simple solutions with a minimum number of parameters that are accurate enough for annual energy calculations of whole building systems. Quasi-static models, which are generally sufficient for such applications, allow the user to deal with the part-load regime. The chiller model is developed and documented on the basis of the following elements: an information flow diagram in which a selection of input and output variables and parameters is proposed, three conceptual schemes in which the main physical hypotheses are expressed, and a set of equations derived from the conceptual schemas. The actual refrigerant cycle is taken into account. Heat exchangers and reciprocating compressors are modeled with some realism. This approach is easy to understand for most engineers and can be easily updated at any time. Practical possibilities of parameter identification (on the basis of catalog data, for example) are provided, and some information about auxiliary consumption is also given. Two alternatives are available for the compressor model: with and without the addition of a fictitious exhaust nozzle intended to produce an effect equivalent to valve pressure drops. Two alternatives are also proposed for parameter identification: looking to the compressor alone or to the whole chiller (i.e., including condenser and evaporator characteristics). Part-load is presumed to be realized by cylinder unloading and cycling between two unloading levels or between the ON and OFF regimes.

Bourdouxhe, J.P.H.; Grodent, M.; Silva, K.L.; Lebrun, J.J. [Univ. of Liege (Belgium). Lab. of Thermodynamics; Saavedra, C. [Univ. of Concepcion (Chile). Dept. of Mechanical Engineering

1994-12-31

336

Life-cycle energy and greenhouse gas emission impacts of different corn ethanol plant types.  

SciTech Connect

Since the United States began a program to develop ethanol as a transportation fuel, its use has increased from 175 million gallons in 1980 to 4.9 billion gallons in 2006. Virtually all of the ethanol used for transportation has been produced from corn. During the period of fuel ethanol growth, corn farming productivity has increased dramatically, and energy use in ethanol plants has been reduced by almost by half. The majority of corn ethanol plants are powered by natural gas. However, as natural gas prices have skyrocketed over the last several years, efforts have been made to further reduce the energy used in ethanol plants or to switch from natural gas to other fuels, such as coal and wood chips. In this paper, we examine nine corn ethanol plant types--categorized according to the type of process fuels employed, use of combined heat and power, and production of wet distiller grains and solubles. We found that these ethanol plant types can have distinctly different energy and greenhouse gas emission effects on a full fuel-cycle basis. In particular, greenhouse gas emission impacts can vary significantly--from a 3% increase if coal is the process fuel to a 52% reduction if wood chips are used. Our results show that, in order to achieve energy and greenhouse gas emission benefits, researchers need to closely examine and differentiate among the types of plants used to produce corn ethanol so that corn ethanol production would move towards a more sustainable path.

Wang, M.; Wu, M.; Huo, H.; Energy Systems

2007-04-01

337

The PCA and IOA approaches for life-cycle analysis of greenhouse gas emissions from Thai commodities and energy consumption  

Microsoft Academic Search

Suksuntornsiri, P. and Limmeechokchai, B. The PCA and IOA approaches for life-cycle analysis of greenhouse gas emissions from Thai commodities and energy consumption Songklanakarin J. Sci. Technol., 2005, 27(1) : 177-189 The use of more substitutable commodities, selected by their total greenhouse gas (GHG) emissions would highly contribute to mitigating the effects of global warming. Life-cycle analysis (LCA) is a

Pawinee Suksuntornsiri; Bundit Limmeechokchai

338

Effects Of Urbanization On Interconnected Water Cycle, Microclimate And Energy Usage In Semi-Arid Regions  

NASA Astrophysics Data System (ADS)

Landscape changes induced by urbanization have been found to influence urban water cycle components including evapotranspiration (ET), runoff and water use. For instance, residential areas in semi-arid regions with vegetation subjected to lawn watering have higher ET rates when compared to the other areas in an urban environment. This increase associated with lawn irrigation can contribute to water scarcity problems. Conversely, development of more built surfaces with reduced vegetation leads to increased temperatures and Urban Heat Islands. This increase in temperature, can lead to an increase in energy usage. In order, to quantify the relationship of interconnected landscape, water cycle, microclimate and energy usage there is a need for a modeling system to represent landscape and surface characteristics specific to location and time. A methodology capable of modeling the interconnected urban scenario via a three-step process is presented in this paper. To account for the variability of urban form, the roughness length variation should be represented. An approach to estimate roughness length from Synthetic Aperture Radar (SAR) data has been introduced and the results are included in this paper. The effect of varying urban form and lawn irrigation practices on latent and sensible heat fluxes is represented and modeled by the Urban Heat Flux Model introduced in this paper. The Urban Heat Flux (UHFL) model has the capability to model the sensible and latent heat fluxes spatially and temporally by being able to represent varying conditions of roughness length, surface resistance and lawn irrigation patterns (soil moisture). The UHFL model has an advantage over the existing models by being driven by easily acquirable meteorological data and remote sensing data (which are available for all regions). The overall modeling framework consists of three sub-models: UHFL, the urban climate model (to simulate urban microclimate) and the energy and water usage simulation modules. The modeling system works by interconnecting the outputs of the sub-models thereby inter-connecting landscape, water use, urban microclimate and energy usage. The proposed modeling system has an advantage being spatially explicit through integration into a geographic information system and being driven by easily available remote sensing data and meteorological data. The model has been applied to study the effects of different development styles on the interconnected factors of landscape, water use, urban microclimate and energy usage in a residential neighborhood in the Salt Lake City metropolitan region. Two specific model runs were executed with normal residential lawns and xeriscape yards. The xeriscape style was found to reduce the latent heat fluxes and increase the air temperature and corresponding energy usage when compared to the normal residential lawns. Hence, the outdoor water usage in semi arid regions exerts an influence on the microclimate and energy usage which needs to be studied in further depth. The modeling system presented in this paper brings forth the use of remote sensing to model and predict the effects of urbanization on water cycle components, urban microclimate and energy usage.

Jeyachandran, I.; Burian, S. J.; Pardyjak, E.

2008-12-01

339

Algal Photosynthesis as the Primary Driver for a Sustainable Development in Energy, Feed, and Food Production  

PubMed Central

High oil prices and global warming that accompany the use of fossil fuels are an incentive to find alternative forms of energy supply. Photosynthetic biofuel production represents one of these since for this, one uses renewable resources. Sunlight is used for the conversion of water and CO2 into biomass. Two strategies are used in parallel: plant-based production via sugar fermentation into ethanol and biodiesel production through transesterification. Both, however, exacerbate other problems, including regional nutrient balancing and the world's food supply, and suffer from the modest efficiency of photosynthesis. Maximizing the efficiency of natural and engineered photosynthesis is therefore of utmost importance. Algal photosynthesis is the system of choice for this particularly for energy applications. Complete conversion of CO2 into biomass is not necessary for this. Innovative methods of synthetic biology allow one to combine photosynthetic and fermentative metabolism via the so-called Photanol approach to form biofuel directly from Calvin cycle intermediates through use of the naturally transformable cyanobacterium Synechocystis sp. PCC 6803. Beyond providing transport energy and chemical feedstocks, photosynthesis will continue to be used for food and feed applications. Also for this application, arguments of efficiency will become more and more important as the size of the world population continues to increase. Photosynthetic cells can be used for food applications in various innovative forms, e.g., as a substitute for the fish proteins in the diet supplied to carnivorous fish or perhaps—after acid hydrolysis—as a complex, animal-free serum for growth of mammalian cells in vitro. PMID:20640935

Anemaet, Ida G.; Bekker, Martijn

2010-01-01

340

Intensity of primary cosmic-ray electrons of energy exceeding 8 GeV  

NASA Technical Reports Server (NTRS)

Results are reported for measurement of the intensity and energy spectrum of primary cosmic-ray electrons with a spark-chamber-counter-emulsion detector flown at a mean altitude of 3 g/sq cm residual atmosphere. A least-squares fit to the flight data yields an electron spectrum from 8 to 80 GeV of approximately 93E to the -2.91 power electrons/sq m/sec per sr/GeV. The results are compared with those of previous experiments as well as with the spectrum obtained for galactic nonthermal radiation. It is concluded that a 'clumpy' magnetic field proportional to the square root of matter density is consistent with measurements of high-energy electrons and synchrotron radiation toward the center of the Galaxy, that a gradual steepening of the electron spectrum relative to the proton spectrum is consistent with an electron lifetime of 1 million years, and that the density of cosmic-ray nucleons and electrons should be essentially uniform throughout the Galaxy if the nucleons have the same lifetime as the electrons and if they traversed 4 to 5 g/sq cm in that lifetime.

Freier, P.; Gilman, C.; Waddington, C. J.

1977-01-01

341

A cumulative energy demand indicator (CED), life cycle based, for industrial waste management decision making.  

PubMed

Life cycle thinking is a good approach to be used for environmental decision-support, although the complexity of the Life Cycle Assessment (LCA) studies sometimes prevents their wide use. The purpose of this paper is to show how LCA methodology can be simplified to be more useful for certain applications. In order to improve waste management in Catalonia (Spain), a Cumulative Energy Demand indicator (LCA-based) has been used to obtain four mathematical models to help the government in the decision of preventing or allowing a specific waste from going out of the borders. The conceptual equations and all the subsequent developments and assumptions made to obtain the simplified models are presented. One of the four models is discussed in detail, presenting the final simplified equation to be subsequently used by the government in decision making. The resulting model has been found to be scientifically robust, simple to implement and, above all, fulfilling its purpose: the limitation of waste transport out of Catalonia unless the waste recovery operations are significantly better and justify this transport. PMID:24045171

Puig, Rita; Fullana-I-Palmer, Pere; Baquero, Grau; Riba, Jordi-Roger; Bala, Alba

2013-12-01

342

Life-Cycle Thinking and the LEED Rating System: Global Perspective on Building Energy Use and Environmental Impacts.  

PubMed

This research investigates the relationship between energy use, geographic location, life cycle environmental impacts, and Leadership in Energy and Environmental Design (LEED). The researchers studied worldwide variations in building energy use and associated life cycle impacts in relation to the LEED rating systems. A Building Information Modeling (BIM) of a reference 43?000 ft(2) office building was developed and situated in 400 locations worldwide while making relevant changes to the energy model to meet reference codes, such as ASHRAE 90.1. Then life cycle environmental and human health impacts from the buildings' energy consumption were calculated. The results revealed considerable variations between sites in the U.S. and international locations (ranging from 394 ton CO2 equiv to 911 ton CO2 equiv, respectively). The variations indicate that location specific results, when paired with life cycle assessment, can be an effective means to achieve a better understanding of possible adverse environmental impacts as a result of building energy consumption in the context of green building rating systems. Looking at these factors in combination and using a systems approach may allow rating systems like LEED to continue to drive market transformation toward sustainable development, while taking into consideration both energy sources and building efficiency. PMID:25706229

Al-Ghamdi, Sami G; Bilec, Melissa M

2015-04-01

343

The sustainable water-energy nexus: Life-cycle impacts and feasibility of regional energy and water supply scenarios  

NASA Astrophysics Data System (ADS)

Water and energy are critical, interdependent, and regional resources, and effective planning and policies around which sources to use requires combining information on environmental impacts, cost, and availability. Questions around shifting energy and water sources towards more renewable options, as well as the potential role of natural gas from shale formations are under intense discussion. Decisions on these issues will be made in the shadow of climate change, which will both impact and be impacted by energy and water supplies. This work developed a model for calculating the life-cycle environmental impacts of regional energy and water supply scenarios (REWSS). The model was used to discuss future energy pathways in Pennsylvania, future electricity impacts in Brazil, and future water pathways in Arizona. To examine energy in Pennsylvania, this work also developed the first process-based life-cycle assessment (LCA) of shale gas, focusing on greenhouse gas (GHG) emissions, energy consumption, and water consumption. This LCA confirmed results that shale gas is similar to conventional gas in GHG emissions, though potentially has a lower net energy due to a wide range of production rates for wells. Brazil's electricity-related impacts will rise as development continues. GHG emissions are shown to double by 2020 due to expanded natural gas (NG) and coal usage, with a rise of 390% by 2040 posssible with tropical hydropower reservoirs. While uncertainty around reservoir impacts is large, Brazil's low GHG emissions intensity and future carbon emissions targets are threatened by likely electricity scenarios. Pennsylvania's energy-related impacts are likely to hinge on whether NG is used as a replacement for coal, allowing GHG emissions to drop and then plateau at 93% of 2010 values; or as a transition fuel to expanded renewable energy sources, showing a steady decrease to 86% in 2035. Increased use of biofuels will dominate land occupation and may dominate water consumption impacts, depending on irrigation -- water consumption for energy rises from 7% to 18% under the base case. Arizona is further from major shale basins, but aims to reduce unsustainable groundwater usage. Desalination by itself will increase annual impacts by at least 2% in all impact categories by 2035, and prioritizing renewable energy sources along with desalination was found to lower GHGs by 1% from BAU, but increase 2035 impacts in all other categories by at least 10% from new construction or operation. In both PA and AZ, changes in impacts and shifting sources have interconnected tradeoffs, making the water-enegy nexus a key part of managing environmental problems such as climate change. Future energy and water supplies are also likely to show higher interdependencies, which may or may not improve regional sustainability. This work offers a way to combine four important sets of information to enable the generation of answers to key regional planning questions around these two key resources.

Dale, Alexander T.

344

Technology for Brayton-cycle space powerplants using solar and nuclear energy  

SciTech Connect

Brayton-cycle gas turbines have the potential to use either solar heat or nuclear reactors to generate from tens of kilowatts to tens of megawatts of power in space, all this from a single technology for the power-generating system. Their development for solar-energy dynamic power generation for the space station could be the first step in an evolution of such powerplants for a very wide range of applications. At the low power level of only 10 kWe, a power-generating system has already demonstrated overall efficiency of 0.29 and operated for 38,000 hr. Tests of improved components show that, if installed in the power-generating system, these components would raise that efficiency to 0.32; this efficiency is twice that so far demonstrated by any alternate concept, a characteristic especially important for solar power systems. Because of this high efficiency, solar-heat Brayton-cycle power generators offer the potential to increase power per unit of solar-collector area to levels exceeding four times that from photovoltaic powerplants based on present technology for silicon solar cells. For the heat source, paraboloidal mirrors have been assembled from sectors here on Earth. One mirror, 1.5-m diameter, had a standard error for its surface of only 1 arc-min and a specific mass of only 1.3 kg/m 2. A heavier mirror (nearly 5 kg/m{sup 2}), assembled from 12 sectors, had a standard surface error of 3 arc-min but was 6 m in diameter. Either of these mirrors is sufficiently accurate for use with the Brayton cycle, but the techniques for actually assembling large mirrors in space must yet be worked out. For use during the shadow period of a low Earth orbit (LEO), heat could be stored in LiF, a salt that melts at 1121 K (1558{degrees}F) and whose latent heat of fusion exceeds 1 MJ/kg. Because of the prior experience with its fabrication and of its tolerance of the thermal cycling in LEO, Nb-1Zr was selected to contain the LiF.

English, R.E.

1986-02-01

345

Study of hydraulic air compression for Ocean Thermal Energy Conversion open-cycle application  

NASA Astrophysics Data System (ADS)

A hydraulic air compressor, which requires no mechanical moving parts and operates in a nearly isothermal mode, can be an alternative for the noncondensible gas disposal of an Ocean Thermal Energy Conversion (OTEC) open-cycle power system. The compressor requires only a downward flow of water to accomplish air compression. An air compressor test loop was assembled and operated to obtain test data that would lead to the design of an OTEC hydraulic air compressor. A one dimensional, hydraulic gas compressor, computer model was employed to simulate the laboratory experiments, and it was tuned to fit the test results. A sensitivity study that shows the effects of various parameters on the applied head of the hydraulic air compression is presented.

Golshani, A.; Chen, F. C.

1983-01-01

346

Seawater test results of Open-Cycle Ocean Thermal Energy Conversion (OC-OTEC) components  

NASA Astrophysics Data System (ADS)

Key components of open-cycle ocean thermal energy conversion systems- the flash evaporator, mist eliminator, passive predeaerator, two surface condenser stages, and two direct-contact condenser stages- have been tested using seawater. These components operate at lower steam pressures and higher inlet noncondensable gas concentrations than do conventional power plant heat exchangers. The rate of heat exchanged between the evaporator and the condenser is on the order of 1.25MW-thermal, requiring a warm seawater flow of about 0.1 cu m/s; the cold seawater flow is on the order of half the warm water flow. In addition to characterizing the performance of the various components, the system has produced potable water from condensation of the steam produced in the evaporator. The information obtained in these tests is being used to design a larger scale experiment in which net power production is expected to be demonstrate for the first time using OC-OTEC technology.

Zangrando, F.; Bharathan, D.; Link, H.; Panchal, C. B.

347

Recurrence of flare energy releases in solar active regions (Cycle 23)  

NASA Astrophysics Data System (ADS)

The following results have been achieved in this work. The distribution of the recurrence times of solar flare events is generally lognormal. The typical flare recurrence times at the cycle 23 minimum and maximum are different: the average times (100-200 min) are most typical of the maximum; at the same time, the minimum is simultaneously characterized by short (several tens of seconds) and long (from several hundreds to a thousand of minutes). The minimal flare recurrence time tends to decrease in an active region with increasing sunspot group area in this region. The average flare recurrence times in an active region have typical values of 120m, 210m, 300m, 400m, and 530m, which is close to the typical periods of long-period sunspot oscillations. The total number of flares in an active region depends on the sunspot area in this region and the flare energy release rate.

Nagovitsyn, Yu. A.; Kuleshova, A. I.

2013-12-01

348

Thermodynamic Analysis of a Rankine Cycle Powered Vapor Compression Ice Maker Using Solar Energy  

PubMed Central

To develop the organic Rankine-vapor compression ice maker driven by solar energy, a thermodynamic model was developed and the effects of generation temperature, condensation temperature, and working fluid types on the system performance were analyzed. The results show that the cooling power per square meter collector and ice production per square meter collector per day depend largely on generation temperature and condensation temperature and they increase firstly and then decrease with increasing generation temperature. For every working fluid there is an optimal generation temperature at which organic Rankine efficiency achieves the maximum value. The cooling power per square meter collector and ice production per square meter collector per day are, respectively, 126.44?W?m?2 and 7.61?kg?m?2?day?1 at the generation temperature of 140°C for working fluid of R245fa, which demonstrates the feasibility of organic Rankine cycle powered vapor compression ice maker. PMID:25202735

Hu, Bing; Bu, Xianbiao; Ma, Weibin

2014-01-01

349

Wild Skylarks Seasonally Modulate Energy Budgets but Maintain Energetically Costly Inflammatory Immune Responses throughout the Annual Cycle  

PubMed Central

A central hypothesis of ecological immunology is that immune defences are traded off against competing physiological and behavioural processes. During energetically demanding periods, birds are predicted to switch from expensive inflammatory responses to less costly immune responses. Acute phase responses (APRs) are a particularly costly form of immune defence, and, hence, seasonal modulations in APRs are expected. Yet, hypotheses about APR modulation remain untested in free-living organisms throughout a complete annual cycle. We studied seasonal modulations in the APRs and in the energy budgets of skylarks Alauda arvensis, a partial migrant bird from temperate zones that experiences substantial ecological changes during its annual cycle. We characterized throughout the annual cycle changes in their energy budgets by measuring basal metabolic rate (BMR) and body mass. We quantified APRs by measuring the effects of a lipopolysaccharide injection on metabolic rate, body mass, body temperature, and concentrations of glucose and ketone. Body mass and BMR were lowest during breeding, highest during winter and intermediate during spring migration, moult and autumn migration. Despite this variation in energy budgets, the magnitude of the APR, as measured by all variables, was similar in all annual cycle stages. Thus, while we find evidence that some annual cycle stages are relatively more energetically constrained, we find no support for the hypothesis that during these annual cycle stages birds compromise an immune defence that is itself energetically costly. We suggest that the ability to mount an APR may be so essential to survival in every annual cycle stage that skylarks do not trade off this costly form of defence with other annual cycle demands. PMID:22570706

Hegemann, Arne; Matson, Kevin D.; Versteegh, Maaike A.; Tieleman, B. Irene

2012-01-01

350

Energy and greenhouse gas profiles of polyhydroxybutyrates derived from corn grain: a life cycle perspective.  

PubMed

Polyhydroxybutyrates (PHB) are well-known biopolymers derived from sugars orvegetable oils. Cradle-to-gate environmental performance of PHB derived from corn grain is evaluated through life cycle assessment (LCA), particularly nonrenewable energy consumption and greenhouse gas emissions. Site-specific process information on the corn wet milling and PHB fermentation and recovery processes was obtained from Telles. Most of energy used in the corn wet milling and PHB fermentation and recovery processes is generated in a cogeneration power plant in which corn stover, assumed to be representative of a variety of biomass sources that could be used, is burned to generate electricity and steam. County level agricultural information is used in estimating the environmental burdens associated with both corn grain and corn stover production. Results show that PHB derived from corn grain offers environmental advantages over petroleum-derived polymers in terms of nonrenewable energy consumption and greenhouse gas emissions. Furthermore, PHB provides greenhouse gas credits, and thus PHB use reduces greenhouse gas emissions compared to petroleum-derived polymers. Corn cultivation is one of the environmentally sensitive areas in the PHB production system. More sustainable practices in corn cultivation (e.g., using no-tillage and winter cover crops) could reduce the environmental impacts of PHB by up to 72%. PMID:18983094

Kim, Seungdo; Dale, Bruce E

2008-10-15

351

Life Cycle Assessment of Thermal Energy Storage: Two-Tank Indirect and Thermocline  

SciTech Connect

In the United States, concentrating solar power (CSP) is one of the most promising renewable energy (RE) technologies for reduction of electric sector greenhouse gas (GHG) emissions and for rapid capacity expansion. It is also one of the most price-competitive RE technologies, thanks in large measure to decades of field experience and consistent improvements in design. One of the key design features that makes CSP more attractive than many other RE technologies, like solar photovoltaics and wind, is the potential for including relatively low-cost and efficient thermal energy storage (TES), which can smooth the daily fluctuation of electricity production and extend its duration into the evening peak hours or longer. Because operational environmental burdens are typically small for RE technologies, life cycle assessment (LCA) is recognized as the most appropriate analytical approach for determining their environmental impacts of these technologies, including CSP. An LCA accounts for impacts from all stages in the development, operation, and decommissioning of a CSP plant, including such upstream stages as the extraction of raw materials used in system components, manufacturing of those components, and construction of the plant. The National Renewable Energy Laboratory (NREL) is undertaking an LCA of modern CSP plants, starting with those of parabolic trough design.

Heath, G.; Turchi, C.; Burkhardt, J.; Kutscher, C.; Decker, T.

2009-07-01

352

Dynamic hybrid life cycle assessment of energy and carbon of multicrystalline silicon photovoltaic systems.  

PubMed

This paper advances the life cycle assessment (LCA) of photovoltaic systems by expanding the boundary of the included processes using hybrid LCA and accounting for the technology-driven dynamics of embodied energy and carbon emissions. Hybrid LCA is an extended method that combines bottom-up process-sum and top-down economic input-output (EIO) methods. In 2007, the embodied energy was 4354 MJ/m(2) and the energy payback time (EPBT) was 2.2 years for a multicrystalline silicon PV system under 1700 kWh/m(2)/yr of solar radiation. These results are higher than those of process-sum LCA by approximately 60%, indicating that processes excluded in process-sum LCA, such as transportation, are significant. Even though PV is a low-carbon technology, the difference between hybrid and process-sum results for 10% penetration of PV in the U.S. electrical grid is 0.13% of total current grid emissions. Extending LCA from the process-sum to hybrid analysis makes a significant difference. Dynamics are characterized through a retrospective analysis and future outlook for PV manufacturing from 2001 to 2011. During this decade, the embodied carbon fell substantially, from 60 g CO(2)/kWh in 2001 to 21 g/kWh in 2011, indicating that technological progress is realizing reductions in embodied environmental impacts as well as lower module price. PMID:20860380

Zhai, Pei; Williams, Eric D

2010-10-15

353

Life cycle energy, environment and economic assessment of soybean-based biodiesel as an alternative automotive fuel in China  

Microsoft Academic Search

Life cycle energy, environment and economic assessment for conventional diesel (CD) and soybean-based biodiesel (SB) in China was carried out in this paper. The results of the assessment have shown that compared with CD, SB has similar source-to-tank (StT) total energy consumption, 76% lower StT fossil energy consumption, 79% higher source-to-wheel (StW) nitrogen oxides (NOX) emissions, 31%, 44%, 36%, 29%,

Zhiyuan Hu; Piqiang Tan; Xiaoyu Yan; Diming Lou

2008-01-01

354

A new control method depending on primary phase angle of transcutaneous energy transmission system for artificial heart.  

PubMed

A new control method for stabilizing output voltage of the transcutaneous energy transmission system for artificial heart is proposed. This method is primary side, is outside of the body, which is not depending on a signal transmission system from the implanted device. The impedance observed from primary side changes from inductive to capacitive and the output voltage decreases drastically when the output current is large and the coupling factor is higher than that of the optimal condition. In this case, the driving frequency should be changed to higher so that the phase angle of the primary impedance is zero degree. The preliminary examination showed that this control method can enhance the output voltage limit to twice and the feasibility of the primary side control. PMID:24111037

Miura, H; Saito, I; Sato, F; Shiraishi, Y; Yambe, T; Matsuki, H

2013-01-01

355

Combined heat and power systems for commercial buildings: investigating cost, emissions, and primary energy reduction based on system components  

NASA Astrophysics Data System (ADS)

Combined heat and power (CHP) systems produce electricity and useful heat from fuel. When power is produced near a building which consumes power, transmission losses are averted, and heat which is a byproduct of power production may be useful to the building. That thermal energy can be used for hot water or space heating, among other applications. This dissertation focuses on CHP systems using natural gas, a common fuel, and systems serving commercial buildings in the United States. First, the necessary price difference between purchased electricity and purchased fuel is analyzed in terms of the efficiencies of system components by comparing CHP with a conventional separate heat and power (SHP) configuration, where power is purchased from the electrical grid and heat is provided by a gas boiler. Similarly, the relationship between CDE due to electricity purchases and due to fuel purchases is analyzed as well as the relationship between primary energy conversion factors for electricity and fuel. The primary energy conversion factor indicates the quantity of source energy necessary to produce the energy purchased at the site. Next, greenhouse gas emissions are investigated for a variety of commercial buildings using CHP or SHP. The relationship between the magnitude of the reduction in emissions and the parameters of the CHP system is explored. The cost savings and reduction in primary energy consumption are evaluated for the same buildings. Finally, a CHP system is analyzed with the addition of a thermal energy storage (TES) component, which can store excess thermal energy and deliver it later if necessary. The potential for CHP with TES to reduce cost, emissions, and primary energy consumption is investigated for a variety of buildings. A case study is developed for one building for which TES does provide additional benefits over a CHP system alone, and the requirements for a water tank TES device are examined.

Smith, Amanda D.

356

Environmental & economic life cycle assessment of current & future sewage sludge to energy technologies.  

PubMed

The UK Water Industry currently generates approximately 800GWh pa of electrical energy from sewage sludge. Traditionally energy recovery from sewage sludge features Anaerobic Digestion (AD) with biogas utilisation in combined heat and power (CHP) systems. However, the industry is evolving and a number of developments that extract more energy from sludge are either being implemented or are nearing full scale demonstration. This study compared five technology configurations: 1 - conventional AD with CHP, 2 - Thermal Hydrolysis Process (THP) AD with CHP, 3 - THP AD with bio-methane grid injection, 4 - THP AD with CHP followed by drying of digested sludge for solid fuel production, 5 - THP AD followed by drying, pyrolysis of the digested sludge and use of the both the biogas and the pyrolysis gas in a CHP. The economic and environmental Life Cycle Assessment (LCA) found that both the post AD drying options performed well but the option used to create a solid fuel to displace coal (configuration 4) was the most sustainable solution economically and environmentally, closely followed by the pyrolysis configuration (5). Application of THP improves the financial and environmental performance compared with conventional AD. Producing bio-methane for grid injection (configuration 3) is attractive financially but has the worst environmental impact of all the scenarios, suggesting that the current UK financial incentive policy for bio-methane is not driving best environmental practice. It is clear that new and improving processes and technologies are enabling significant opportunities for further energy recovery from sludge; LCA provides tools for determining the best overall options for particular situations and allows innovation resources and investment to be focused accordingly. PMID:24060290

Mills, N; Pearce, P; Farrow, J; Thorpe, R B; Kirkby, N F

2014-01-01

357

Revised Energy Spectra for Primary Elements, H - Si, above 50 GeV from the ATIC-2 Science Flight  

NASA Technical Reports Server (NTRS)

The Advanced Thin Ionization Calorimeter (ATIC) long duration balloon experiment had a successful science flight accumulating 18 days of data (12/02 - 1/03) during a single circumnavigation in Antarctica. ATIC measures the energy spectra of elements from H to Fe in primary cosmic rays using a fully active Bismuth Germanate calorimeter preceded by a carbon target, with embedded scintillator hodoscopes, and a silicon matrix charge detector at the top. Preliminary results from ATIC have been reported in previous conferences. The revised results reported here are derived from a new analysis of the data with improved charge resolution, lower background and revised energy calibration. The raw energy deposit spectra are de-convolved into primary energy spectra and extrapolated to the top of the atmosphere. We compare these revised results to previous data and comment upon the astrophysical interpretation of the results.

Wefel, J. P.; Adams, J. H., Jr.; Ahn, H. S.; Bashindzhagyan, G. L.; Chang, J.; Christl, M.; Fazely, A. R.; Ganel, O.; Gunashingha, R. M.; Guzik, T. G.; Isbert, J.; Kim, K. C.; Kouznetsov, E. N.; Panasyuk, M. I.; Panov, A. D.; Schmidt, W. K. H.; Seo, E. S.; Sokolskaya, N. V.; Watts, J. W.; Wu, J.; Zatsepin, V. I.

2007-01-01

358

Total energy cycle assessment of electric and conventional vehicles: an energy and environmental analysis. Volume 2: appendices A-D to technical report  

SciTech Connect

This report compares the energy use, oil use and emissions of electric vehicles (EVs) with those of conventional, gasoline- powered vehicles (CVs) over the total life cycle of the vehicles. The various stages included in the vehicles` life cycles include vehicle manufacture, fuel production, and vehicle operation. Disposal is not included. An inventory of the air emissions associated with each stage of the life cycle is estimated. Water pollutants and solid wastes are reported for individual processes, but no comprehensive inventory is developed. Volume II contains additional details on the vehicle, utility, and materials analyses and discusses several details of the methodology.

NONE

1998-01-01

359

A Practical Approach to a Closed Nuclear Fuel Cycle and Sustained Nuclear Energy - 12383  

SciTech Connect

Recent systems analysis studies at Oak Ridge National Laboratory (ORNL) have shown that sufficient information is available from previous research and development (R and D), industrial experience, and current studies to make rational decisions on a practical approach to a closed nuclear fuel cycle in the United States. These studies show that a near-term decision is needed to recycle used nuclear fuel (UNF) in the United States, to encourage public recognition that a practical solution to disposal of nuclear energy wastes, primarily UNF, is achievable, and to ensure a focus on essential near-term actions and future R and D. Recognition of the importance of time factors is essential, including the multi-decade time period required to implement industrial-scale fuel recycle at the capacity needed, and the effects of radioactive decay on proliferation resistance, recycling complexity, radioactive emissions, and high-level-waste storage, disposal form development, and eventual emplacement in a geologic repository. Analysis of time factors led to identification of the benefits of processing older fuel and an 'optimum decay storage time'. Further benefits of focused R and D can ensure more complete recycling of UNF components and minimize wastes requiring disposal. Analysis of recycling costs and nonproliferation requirements, which are often cited as reasons for delaying a decision to recycle, shows that (1) the differences in costs of nuclear energy with open or closed fuel cycles are insignificant and (2) nonproliferation requirements can be met by a combination of 'safeguards-by-design' co-location of back-end fuel cycle facilities, and applied engineered safeguards and monitoring. The study shows why different methods of separating and recycling used fuel components do not have a significant effect on nonproliferation requirements and can be selected on other bases, such as process efficiency, maturity, and cost-effectiveness. Finally, the study concludes that continued storage of UNF without a decision to recycle is not a solution to the problem of nuclear waste disposal, but can be a deterrent to public confidence in nuclear energy. In summary, our studies have shown, in contrast to findings of the more prominent studies, that today we do have sufficient knowledge to make informed choices for the values and essential methods of UNF recycling, based on previous research, industrial experience, and current analyses. We have shown the significant importance of time factors, including the benefits of an optimum decay storage time on deploying effective nonproliferation safeguards, enabling reduced recycling complexity and environmental emissions, and optimizing waste management and disposal. Together with the multi-decade time required to implement industrial-scale UNF recycle at the capacity needed to match generation rate, our conclusion is that a near-term decision to recycle as many UNF components as possible is vitally needed. Further indecision and procrastination can lead to a loss of public confidence and favorable perception of nuclear energy. With no near-term decision, the path forward for UNF disposal will remain uncertain, with many diverse technologies being considered and no possible focus on a practical solution to the problem. However, a near-term decision to recycle UNF fuel and to take advantage of processing UNF and surface storing HLW, together with development and incorporation of more-complete recycling of UNF components, can provide the focus needed for a practical solution to the problem of nuclear waste disposal. (authors)

Collins, Emory D.; Del Cul, Guillermo D.; Spencer, Barry B.; Williams, Kent A. [Oak Ridge National Laboratory, P.O. Box 2008, MS-6152, Oak Ridge TN 37831 (United States)

2012-07-01

360

Determining the primary cosmic ray energy from the total flux of Cherenkov light measured at the Yakutsk EAS array  

SciTech Connect

We present a method for determining the energy of the primary particle that generates an extensive air shower (EAS) of comic rays based on measuring the total flux of Cherenkov light from the shower. Applying this method to Cherenkov light measurements at the Yakutsk EAS array has allowed us to construct the cosmic ray energy spectrum in the range 10{sup 15} - 3 x 10{sup 19} eV.

Ivanov, A. A., E-mail: ivanov@ikfia.ysn.ru; Knurenko, S. P.; Sleptsov, I. E. [Shafer Institute for Cosmophysical Research and Aeronomy (Russian Federation)

2007-06-15

361

Biomass pyrolysis for biochar or energy applications? A life cycle assessment.  

PubMed

The application of biochar as a soil amendment is a potential strategy for carbon sequestration. In this paper, a slow pyrolysis system for generating heat and biochar from lignocellulosic energy crops is simulated and its life-cycle performance compared with that of direct biomass combustion. The use of the char as biochar is also contrasted with alternative use options: cofiring in coal power plants, use as charcoal, and use as a fuel for heat generation. Additionally, the influence on the results of the long-term stability of the biochar in the soil, as well as of biochar effects on biomass yield, is evaluated. Negative greenhouse gas emissions are obtained for the biochar system, indicating a significant carbon abatement potential. However, this is achieved at the expense of lower energy efficiency and higher impacts in the other assessed categories when compared to direct biomass combustion. When comparing the different use options of the pyrolysis char, the most favorable result is obtained for char cofiring substituting fossil coal, even assuming high long-term stability of the char. Nevertheless, a high sensitivity to biomass yield increase is found for biochar systems. In this sense, biochar application to low-quality soils where high yield increases are expected would show a more favorable performance in terms of global warming. PMID:25830564

Peters, Jens F; Iribarren, Diego; Dufour, Javier

2015-04-21

362

Changes in the Water and Energy Cycles of the American Midwest  

NASA Astrophysics Data System (ADS)

Prediction and understanding of the regional impact of climate change in the American Midwest is of critical importance to agriculture, economy, and society. In particular, predicting the sign and magnitude of the future change in soil moisture conditions is a significant research challenge. During the summer, the input of water to the regional soil moisture (rainfall) is significantly smaller than the output from the same system (evaporation plus surface runoff). This deficit is currently supplied by drawing from the stored soil water in the saturated and unsaturated zones. Therefore, the fundamental research question raised is what will happen to the magnitude of this deficit in the coming decades? If this deficit increases significantly, e.g. due to a significant increase in evaporation, dry soil moisture conditions would develop every year at the end of the summer season. Predicting the magnitude of this deficit under climate change scenarios would require the use of models that are capable of simulating not only the right current climatology of rainfall, evaporation, and runoff, but also the right sign and magnitude of the sensitivity of these processes to climate change. Observations of the water cycle and surface energy balance from the Illinois State Water Survey and FLUXNET will be used to characterize the current climatology in Illinois and examine the sensitivity of latent heat flux to changes in available energy. Implications of the results from regional climate model simulations will be discussed in the context of global climate change and future agricultural productivity.

Eltahir, E. A.; Winter, J. M.

2008-05-01

363

Fuel-cycle energy and emissions impacts of tripled fuel-economy vehicles  

SciTech Connect

This paper presents estimates of the fill fuel-cycle energy and emissions impacts of light-duty vehicles with tripled fuel economy (3X vehicles) as currently being developed by the Partnership for a New Generation of Vehicles (PNGV). Seven engine and fuel combinations were analyzed: reformulated gasoline, methanol, and ethanol in spark-ignition, direct-injection engines; low-sulfur diesel and dimethyl ether in compression-ignition, direct-injection engines; and hydrogen and methanol in fuel-cell vehicles. Results were obtained for three scenarios: a Reference Scenario without PNGVs, a High Market Share Scenario in which PNGVs account for 60% of new light-duty vehicle sales by 2030, and a Low Market Share Scenario in which PNGVs account for half as many sales by 2030. Under the higher of these two, the fuel-efficiency gain by 3X vehicles translated directly into a nearly 50% reduction in total energy demand, petroleum demand, and carbon dioxide emissions. The combination of fuel substitution and fuel efficiency resulted in substantial reductions in emissions of nitrogen oxide (NO{sub x}), carbon monoxide (CO), volatile organic compounds (VOCs), sulfur oxide, (SO{sub x}), and particulate matter smaller than 10 microns (PM{sub 10}) for most of the engine-fuel combinations examined. The key exceptions were diesel- and ethanol-fueled vehicles for which PM{sub 10} emissions increased.

Mintz, M. M.; Vyas, A. D.; Wang, M. Q.

1997-12-18

364

Hormonal changes and energy substrate availability during the hibernation cycle of Syrian hamsters.  

PubMed

Animals have to adapt to seasonal variations in food resources and temperature. Hibernation is one of the most efficient means used by animals to cope with harsh winter conditions, wherein survival is achieved through a significant decrease in energy expenditure. The hibernation period is constituted by a succession of torpor bouts (hypometabolism and decrease in body temperature) and periodic arousals (eumetabolism and euthermia). Some species feed during these periodic arousals, and thus show different metabolic adaptations to fat-storing species that fast throughout the hibernation period. Our study aims to define these metabolic adaptations, including hormone (insulin, glucagon, leptin, adiponectin, GLP-1, GiP) and metabolite (glucose, free fatty acids, triglycerides, urea) profiles together with body composition adjustments. Syrian hamsters were exposed to varied photoperiod and temperature conditions mimicking different phases of the hibernation cycle: a long photoperiod at 20 °C (LP20 group), a short photoperiod at 20 °C (SP20 group), and a short photoperiod at 8 °C (SP8). SP8 animals were sampled either at the beginning of a torpor bout (Torpor group) or at the beginning of a periodic arousal (Arousal group). We show that fat store mobilization in hamsters during torpor bouts is associated with decreased circulating levels of glucagon, insulin, leptin, and an increase in adiponectin. Refeeding during periodic arousals results in a decreased free fatty acid plasma concentration and an increase in glycemia and plasma incretin concentrations. Reduced incretin and increased adiponectin levels are therefore in accordance with the changes in nutrient availability and feeding behavior observed during the hibernation cycle of Syrian hamsters. PMID:24005184

Weitten, Mathieu; Robin, Jean-Patrice; Oudart, Hugues; Pévet, Paul; Habold, Caroline

2013-09-01

365

Transitions in the surface energy balance during the life cycle of a monsoon season  

NASA Astrophysics Data System (ADS)

In this observational/diagnostic study, we illustrate the time history of some important parameters of the surface energy balance during the life cycle of a single monsoon season. This chronology of the surface energy balance portrays the differential equilibrium state from the preonset phase to the withdrawal phase. This includes an analysis of the time history of base variables such as soil moisture, ground temperature, cloud cover, precipitation and humidity. This is followed by an analysis of the components of the surface energy balance where we note subtle changes in the overall balances as we proceed from one epoch of the monsoon to the next. Of interest here is the transition sequence: preonset, onset, break, revival, break, revival and withdrawal during the year 2001. Computations are all illustrated for a box over central India where the coastal effects were small, data coverage was not sparse and where the semi-arid land mass changes drastically to a lush green area. This region exhibited large changes in the components of surface energy balance. The principal results pertain to what balances the difference among the incoming short wave radiation (at the earth’s surface) and the long wave radiation exhibited by the ground. That difference is balanced by a dominant sensible heat flux and the reflected short wave radiation in the preonset stage. A sudden change in the Bowen ratio going from>1 to <1 is noted soon after the onset of monsoon. Thereafter the latent heat flux from the land surface takes an important role and the sensible heat flux acquires a diminishing role. We also examine the subtle changes that occur in the components of surface energy balance between the break and the active phases. The break phases are seen to be quite different from the preonset phases. This study is aimed to illustrate the major importance of moisture and clouds in the radiative transfer computations that are central to the surface energy balance during each epoch. These sensitivities (of moisture and clouds) have major consequences for weather and climate forecasts

Krishnamurti, T. N.; Biswas, Mrinal K.

2006-04-01

366

High-Energy-Density, Low-Temperature Li/CFx Primary Cells  

NASA Technical Reports Server (NTRS)

High-energy-density primary (nonrechargeable) electrochemical cells capable of relatively high discharge currents at temperatures as low as -40 C have been developed through modification of the chemistry of commercial Li/CFx cells and batteries. The commercial Li/CFx units are not suitable for high-current and low-temperature applications because they are current limited and their maximum discharge rates decrease with decreasing temperature. The term "Li/CFx" refers to an anode made of lithium and a cathode made of a fluorinated carbonaceous material (typically graphite). In commercial cells, x typically ranges from 1.05 to 1.1. This cell composition makes it possible to attain specific energies up to 800 Wh/kg, but in order to prevent cell polarization and the consequent large loss of cell capacity, it is typically necessary to keep discharge currents below C/50 (where C is numerically equal to the current that, flowing during a charge or discharge time of one hour, would integrate to the nominal charge or discharge capacity of a cell). This limitation has been attributed to the low electronic conductivity of CFx for x approx. 1. To some extent, the limitation might be overcome by making cathodes thinner, and some battery manufacturers have obtained promising results using thin cathode structures in spiral configurations. The present approach includes not only making cathodes relatively thin [.2 mils (.0.051 mm)] but also using sub-fluorinated CFx cathode materials (x < 1) in conjunction with electrolytes formulated for use at low temperatures. The reason for choosing sub-fluorinated CFx cathode materials is that their electronic conductivities are high, relative to those for which x > 1. It was known from recent prior research that cells containing sub-fluorinated CFx cathodes (x between 0.33 and 0.66) are capable of retaining substantial portions of their nominal low-current specific energies when discharged at rates as high as 5C at room temperature. However, until experimental cells were fabricated following the present approach and tested, it was not known whether or to what extent low-temperature performance would be improved.

Whitacre, Jay; Bugga, Ratnakumar; Smart, Marshall; Prakash, G.; Yazami, Rachid

2007-01-01

367

Students' Understanding of Energy Flow and Matter Cycling in the Context of the Food Chain, Photosynthesis, and Respiration  

ERIC Educational Resources Information Center

The research focus on children's science has recently shifted from separate concepts to more comprehensive and complex topics. This study addressed pupils' understanding of the complex topic of energy flow and matter cycling. A scoring system with three categories and six concepts was developed and used by four biology teachers to analyze 106…

Lin, Chen-Yung; Hu, Reping

2003-01-01

368

The land cover and carbon cycle consequences of large-scale utilizations of biomass as an energy source  

Microsoft Academic Search

The use of modern biomass for energy generation has been considered in many studies as a possible measure for reducing or stabilizing global carbon dioxide (CO2) emissions. In this paper we assess the impacts of large-scale global utilization of biomass on regional and grid scale land cover, greenhouse gas emissions, and carbon cycle. We have implemented in the global environmental

Rik Leemans; André van Amstel; Coos Battjes; Eric Kreileman; Sander Toet

1996-01-01

369

A comprehensive life cycle analysis of cofiring algae in a coal power plant as a solution for achieving sustainable energy  

Microsoft Academic Search

Algae cofiring scenarios in a 360 MW coal power plant were studied utilizing an ecologically based hybrid life cycle assessment methodology. The impacts on the ecological system were calculated in terms of cumulative mass, energy, industrial exergy, and ecological exergy. The environmental performance metrics, including efficiency, loading, and renewability ratios were also quantified to assess the sustainability of cofiring scenarios from

Murat Kucukvar; Omer Tatari

2011-01-01

370

The Global-Energy and Water Cycle Experiment (GEWEX) Continental-Scale International Project (GCIP): An overview  

Microsoft Academic Search

This paper provides a brief historical overview of the Global Energy and Water Cycle Experiment (GEWEX) Continental-Scale International Project (GCIP), the basis for selecting the principal site for this experiment, the scientific objectives, and the strategic planning that has been brought to bear in preparing for the implementation of the project. It also provides a summary of the 25 papers

Michael Coughlan; Roni Avissar

1996-01-01

371

Recycling revisited—life cycle comparisons of global warming impact and total energy use of waste management strategies  

Microsoft Academic Search

Recycling of waste materials has been analysed from a life cycle perspective in a number of studies over the past 10–15 years. Publications comparing the global warming impact and total energy use of recycling versus incineration and landfilling were reviewed in order to find out to what extent they agree or contradict each other, and whether there are generally applicable

Anna Björklund; Göran Finnveden

2005-01-01

372

Life cycle assessment of processes for the treatment of wastewater urban sludge: energy and global warming analysis  

Microsoft Academic Search

This study compares six wastewater sludge treatment scenarios applied to a 300,000 equivalent-inhabitant (eq. inh) wastewater treatment plant: agricultural spreading, fluidised bed incineration, wet oxidation, pyrolysis, incineration in cement kilns and landfill. The study focuses on energy and emissions contributing to global warming over the whole treatment life cycle. As a result, avoided burdens by coproducts are very important in

G. Houillon; O. Jolliet

2005-01-01

373

Life cycle assessment of urban waste management: Energy performances and environmental impacts. The case of Rome, Italy  

Microsoft Academic Search

Landfilling is nowadays the most common practice of waste management in Italy in spite of enforced regulations aimed at increasing waste pre-sorting as well as energy and material recovery. In this work we analyse selected alternative scenarios aimed at minimizing the unused material fraction to be delivered to the landfill. The methodological framework of the analysis is the life cycle

Francesco Cherubini; Silvia Bargigli; Sergio Ulgiati

2008-01-01

374

Data collection and management for Global Energy and Water Cycle Experiment (GEWEX) Continental-Scale International Project (GCIP)  

Microsoft Academic Search

The Global Energy and Water Cycle Experiment (GEWEX) Continental-Scale International Project (GCIP) was focused on the Mississippi River basin to take advantage of the existing meteorological and hydrological networks that were upgraded with new Doppler radars, wind profilers, and automatic weather stations together with an upgraded version of the Geostationary Operational Environmental Satellites (GOES) operated by the United States. The

J. Leese; S. Williams; R. Jenne; A. Ritchie

2003-01-01

375

Life cycle assessment and evaluation of energy payback time on high-concentration photovoltaic power generation system  

Microsoft Academic Search

In this study, the environmental load of photovoltaic power generation system (PV) during its life cycle and energy payback time (EPT) are evaluated by LCA scheme. Two hypothetical case studies in Toyohashi, Japan and Gobi dessert in China have been carried out to investigate the influence of installation location and PV type on environmental load and EPT. The environmental load

A. Nishimura; Y. Hayashi; K. Tanaka; M. Hirota; S. Kato; M. Ito; K. Araki; E. J. Hu

2010-01-01

376

Life cycle inventory of energy production in ArcelorMittal steel power plant Poland S.A. in Krakow, Poland  

Microsoft Academic Search

Purpose  The goal of this paper is to describe the life cycle inventory (LCI) approach of energy produced by ArcelorMittal Steel Power\\u000a Plant Poland (AMSPPP) in Krakow, Poland. The present LCI is representative for the reference year 2005 by application of ISO\\u000a 14040: 2006. The system boundaries were labeled as gate-to-gate (it covered full process chain for energy production). Background\\u000a data

Boguslaw Bieda

2011-01-01

377

Determination of primary and secondary amines in foodstuffs using gas chromatography and chemiluminescence detection with a modified thermal energy analyser.  

PubMed

A simple method is described for the determination of primary and secondary amines in foodstuffs by gas chromatography with a modified thermal energy analyser, operated in the nitrogen mode. Food samples were subjected to mineral oil vacuum distillation and the isolated amines were derivatized with benzenesulphonyl chloride to form the corresponding sulphonamides, which were fractionated to yield primary and secondary amine derivatives using a modified Hinsberg procedure. The detection limit for individual amines using a 10-g food sample was 10 micrograms/kg (ppb) and recoveries were in excess of 80%. PMID:2013610

Pfundstein, B; Tricker, A R; Preussmann, R

1991-02-01

378

Plasma-based generation and control of a single few-cycle high-energy ultrahigh-intensity laser pulse.  

PubMed

A laser-boosted relativistic solid-density paraboloidal foil is known to efficiently reflect and focus a counterpropagating laser pulse. Here we show that in the case of an ultrarelativistic counterpropagating pulse, a high-energy and ultrahigh-intensity reflected pulse can be more effectively generated by a relatively slow and heavy foil than by a fast and light one. This counterintuitive result is explained with the larger reflectivity of a heavy foil, which compensates for its lower relativistic Doppler factor. Moreover, since the counterpropagating pulse is ultrarelativistic, the foil is abruptly dispersed and only the first few cycles of the counterpropagating pulse are reflected. Our multidimensional particle-in-cell simulations show that even few-cycle counterpropagating laser pulses can be further shortened (both temporally and in the number of laser cycles) with pulse amplification. A single few-cycle, multipetawatt laser pulse with several joules of energy and with a peak intensity exceeding 10(23)??W/cm(2) can be generated already employing next-generation high-power laser systems. In addition, the carrier-envelope phase of the generated few-cycle pulse can be tuned provided that the carrier-envelope phase of the initial counterpropagating pulse is controlled. PMID:25062199

Tamburini, M; Di Piazza, A; Liseykina, T V; Keitel, C H

2014-07-11

379

PSTAR: Primary and secondary terms analysis and renormalization: A unified approach to building energy simulations and short-term monitoring  

SciTech Connect

This report presents a unified method of hourly simulation of a building and analysis of performance data. The method is called Primary and Secondary Terms Analysis and Renormalization (PSTAR). In the PSTAR method, renormalized parameters are introduced for the primary terms such that the renormalized energy balance equation is best satisfied in the least squares sense, hence, the name PSTAR. PSTAR allows extraction of building characteristics from short-term tests on a small number of data channels. These can be used for long-term performance prediction (''ratings''), diagnostics, and control of heating, ventilating, and air conditioning systems (HVAC), comparison of design versus actual performance, etc. By combining realistic building models, simple test procedures, and analysis involving linear equations, PSTAR provides a powerful tool for analyzing building energy as well as testing and monitoring. It forms the basis for the Short-Term Energy Monitoring (STEM) project at SERI.

Subbarao, K.

1988-09-01

380

A high-rate and long cycle life aqueous electrolyte battery for grid-scale energy storage.  

PubMed

New types of energy storage are needed in conjunction with the deployment of solar, wind and other volatile renewable energy sources and their integration with the electric grid. No existing energy storage technology can economically provide the power, cycle life and energy efficiency needed to respond to the costly short-term transients that arise from renewables and other aspects of grid operation. Here we demonstrate a new type of safe, fast, inexpensive, long-life aqueous electrolyte battery, which relies on the insertion of potassium ions into a copper hexacyanoferrate cathode and a novel activated carbon/polypyrrole hybrid anode. The cathode reacts rapidly with very little hysteresis. The hybrid anode uses an electrochemically active additive to tune its potential. This high-rate, high-efficiency cell has a 95% round-trip energy efficiency when cycled at a 5C rate, and a 79% energy efficiency at 50C. It also has zero-capacity loss after 1,000 deep-discharge cycles. PMID:23093186

Pasta, Mauro; Wessells, Colin D; Huggins, Robert A; Cui, Yi

2012-01-01

381

Energy conservation through hybrid air-conditioning cycles: computer modeling studies  

Microsoft Academic Search

In this paper the authors have presented a review, analysis and computer modelling of desiccant based hybrid air-conditioning (A\\/C) cycles for typical hot and humid conditions. Three hybrid cycles based on solid desiccant dehumidifier (viz. ventilation\\/condenser, recirculation\\/condenser and ventilation\\/heat exchanger cycles) have been evaluated and compared in performance with a conventional vapour compression A\\/C system. Computer modelling and analysis is

M. Singh; S. Jain; S. C. Kaushik

1997-01-01

382

Interactive Video Game Cycling Leads to Higher Energy Expenditure and Is More Enjoyable than Conventional Exercise in Adults  

PubMed Central

Background Despite the widely accepted health benefits of regular physical activity, only a small percentage of the population meets the current recommendations. The reasons include a wide use of technology and a lack of enjoyment while exercising. The purpose of this study was to compare the physiological, perceptual and enjoyment responses between a single bout of (I) conventional cycling and (II) interactive cycling video game at a matched workload. Methods A cross-sectional study in 34 healthy participants was performed. Initially, participants completed an incremental maximal cycling test to measure peak oxygen uptake and to determine ventilatory threshold. In random order, participants carried out a 30 min interactive cycling trial and a 30 min conventional cycling trial at 55% of peak power output. During the trials, oxygen uptake and energy expenditure were measured by open-circuit spirometry and heart rate was measured by radiotelemetry. RPE and enjoyment were measured every 10 minutes with Borg scale and a modified PACES scale. Results Interactive cycling resulted in a significantly greater %V?O2Reserve (68.2% ± 9.2% vs 64.7% ± 8.1%), rate of energy expenditure (505.8±75.2 vs 487.4±81.2 j·kg-1·min-1), and enjoyment (63.4% ± 17 vs 42% ± 13.6), P<0.05. Participants were working at a higher intensity in relation to the individual’s ventilatory threshold during the interactive cycling video game trial (M = 11.86, SE = 3.08) than during the Conventional cycling trial (M = 7.55, SE = 3.16, t(33) = -2.69, P<0.05, r = .42). No significant differences were found for heart rate reserve (72.5 ± 10.4 vs 71.4±10.1%) and RPE (13.1 ± 1.8 vs 13.2 ± 1.7). Conclusion Interactive cycling games can be a valid alternative to conventional exercise as they result in a higher exercise intensity than conventional cycling and a distraction from aversive cognitive and physiological states at and above the ventilatory threshold. PMID:25738290

Monedero, Javier; Lyons, Elizabeth J.; O’Gorman, Donal J.

2015-01-01

383

Homology-mediated end-capping as a primary step of sister chromatid fusion in the breakage-fusion-bridge cycles  

PubMed Central

Breakage-fusion-bridge (BFB) cycle is a series of chromosome breaks and duplications that could lead to the increased copy number of a genomic segment (gene amplification). A critical step of BFB cycles leading to gene amplification is a palindromic fusion of sister chromatids following the rupture of a dicentric chromosome during mitosis. It is currently unknown how sister chromatid fusion is produced from a mitotic break. To delineate the process, we took an integrated genomic, cytogenetic and molecular approach for the recurrent MCL1 amplicon at chromosome 1 in human tumor cells. A newly developed next-generation sequencing-based approach identified a cluster of palindromic fusions within the amplicon at ?50-kb intervals, indicating a series of breaks and fusions by BFB cycles. The physical location of the amplicon (at the end of a broken chromosome) further indicated BFB cycles as underlying processes. Three palindromic fusions were mediated by the homologies between two nearby inverted Alu repeats, whereas the other two fusions exhibited microhomology-mediated events. Such breakpoint sequences indicate that homology-mediated fold-back capping of broken ends followed by DNA replication is an underlying mechanism of sister chromatid fusion. Our results elucidate nucleotide-level events during BFB cycles and end processing for naturally occurring mitotic breaks. PMID:23975201

Marotta, Michael; Chen, Xiongfong; Watanabe, Takaaki; Faber, Pieter W.; Diede, Scott J.; Tapscott, Stephen; Tubbs, Raymond; Kondratova, Anna; Stephens, Robert; Tanaka, Hisashi

2013-01-01

384

Environmental performance of renewable energy systems with the application of life-cycle assessment: a multi-Si photovoltaic module case study  

Microsoft Academic Search

Life-cycle thinking significantly affects the assessment of the environmental performance of a system. In this study, the life-cycle assessment of a multi-Si photovoltaic (PV) module was conducted in order to examine the environmental burden throughout its life cycle and benchmark it with the environmental burden of the identical conventional energy produced with the energy mix of Greece and supplied by

G. Gaidajis; K. Angelakoglou

2012-01-01

385

Evidence for Solar Cycle Influence on the Infrared Energy Budget and Radiative Cooling of the Thermosphere  

NASA Technical Reports Server (NTRS)

We present direct observational evidence for solar cycle influence on the infrared energy budget and radiative cooling of the thermosphere. By analyzing nearly five years of data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, we show that the annual mean infrared power radiated by the nitric oxide (NO) molecule at 5.3 m has decreased by a factor of 2.9. This decrease is correlated (r = 0.96) with the decrease in the annual mean F10.7 solar index. Despite the sharp decrease in radiated power (which is equivalent to a decrease in the vertical integrated radiative cooling rate), the variability of the power as given in the standard deviation of the annual means remains approximately constant. A simple relationship is shown to exist between the infrared power radiated by NO and the F10.7 index, thus providing a fundamental relationship between solar activity and the thermospheric cooling rate for use in thermospheric models. The change in NO radiated power is also consistent with changes in absorbed ultraviolet radiation over the same time period.

Mlynczak, Martin G.; Martin-Torres, F. Javier; Marshall, B. Thomas; Thompson, R. Earl; Williams, Joshua; Turpin, TImothy; Kratz, D. P.; Russell, James M.; Woods, Tom; Gordley, Larry L.

2007-01-01

386

Improving the actinides recycling in closed fuel cycles, a major step towards nuclear energy sustainability  

SciTech Connect

Increasing the sustainability of nuclear energy is a longstanding road that requires a stepwise approach to successively tackle the following 3 objectives. First of all, optimize the consumption of natural resource to preserve them for future generations and hence guarantee the energetic independence of the countries (no uranium ore is needed anymore). The current twice-through cycle of Pu implemented by France, UK, Japan and soon China is a first step in this direction and already allows the development and optimization of the relevant industrial processes. It also allows a major improvement regarding the conditioning of the ultimate waste in a durable and robust nuclear glass. Secondly, the recycling of americium could be an interesting option for the future with the deployment of FR fleet to save the repository resource and optimize its use by allowing a denser disposal. It would limit the burden towards the future generations and the need for additional repositories before several centuries. Thirdly, the recycling of the whole minor actinides inventory could be an interesting option for the far-future for strongly decreasing the waste long-term toxicity, down to a few centuries. It would bring the waste issue back within the human history, which should promote its acceptance by the social opinion.

Poinssot, C.; Grandjean, S.; Masson, M. [RadioChemistry and Processes Department, CEA Marcoule, 30207 Bagnols sur Ceze (France); Bouillis, B.; Warin, D. [Innovation and Industrial Support Direction, CEA Saclay, F-91191 Gif-sur-Yvette (France)

2013-07-01

387

Effect of Energy Expenditure and Training Status on Leptin Response to Sub-Maximal Cycling  

PubMed Central

We examined the leptin response and related hormones during and after two sub-maximal exercise protocols in trained and untrained subjects. During this study, plasma concentrations of leptin [Lep], insulin [I], cortisol [C], growth hormone [GH], glucose [G] and lactate [La] were measured. 7 elite volleyball trained players (TR) and 7 untrained (UTR) subjects (percent body fat: 13.2 ± 1.8 versus 15.7 ± 1.0, p < 0.01, respectively) were examined after short and prolonged sub-maximal cycling exercise protocols (SP and PP). Venous blood samples were collected before each protocol, during, at the end, and after 2 and 24 h of recovery. SP and PP energy expenditures ranged from 470 ± 60 to 740 ± 90 kcal for TR and from 450 ± 60 to 710 ± 90 kcal for UTR, respectively. [Lep] was related to body fat percentage and body fat mass in TR (r = 0. 84, p < 0.05 and r = 0.93, p < 0.01) and in UTR (r = 0.89, p < 0.01 and r = 0.92, p < 0. 01, respectively). [Lep] did not change significantly during both protocols for both groups but was lower (p < 0.05) in all sampling in TR when compared to UTR. Plasma [I] decreased (p < 0.01) and [GH] increased (p < 0.01) significantly during both SP and PP and these hormones remained lower (I: p < 0.01) and higher (GH: p < 0.01) than pre-exercise levels after a 2-h recovery period, returning to base-line at 24-h recovery. Plasma [La] increased (p < 0.01) during both protocols for TR and UTR. There was no significant change in [C] and [G] during and after both protocols for all subjects. It is concluded that 1) leptin is not sensitive to acute short or prolonged sub-maximal exercises (with energy expenditure under 800 kcal) in volleyball/ anaerobically trained athletes as in untrained subjects, 2) volleyball athletes showed significantly lower resting and exercise leptin response with respect to untrained subjects and 3) it appears that in these anaerobically trained athletes leptin response to exercise is more sensitive to the level of energy expenditure than hormonal or metabolic modifications induced by acute exercise. Key points Trials concerning acute exercise and leptin indicated discrepant results. Acute exercise with energy expenditure higher than 800 kcal can decrease leptinemia. Elite volleyball players presented decreased leptin levels than untrained subjects. PMID:24149525

Bouassida, Anissa; Chatard, Jean-Claude; Chamari, Karim; Zaouali, Monia; Feki, Youssef; Gharbi, Najoua; Zbidi, Abdelkarim; Tabka, Zouhaïr

2009-01-01

388

A possible correlation between the high-energy electron spectrum and the cosmic ray secondary-to-primary ratios  

NASA Astrophysics Data System (ADS)

Recent observations of high-energy cosmic ray electrons by the Fermi-Large Area Telescope (LAT) and the High Energy Stereoscopic System (HESS) experiments between 20 GeV and 5 TeV have found that the energy spectrum closely follows a broken power law with a break at around 1 TeV. On the other hand, measurements of cosmic ray secondary-to-primary ratios like the boron-to-carbon ratio seem to indicate a possible change in the slope at energies around 100 GeV n-1. In this paper, we discuss one possible explanation for the observed break in the electron spectrum and its possible correlation with the flattening in the secondary-to-primary ratios at higher energies. In our model, we assume that cosmic rays after acceleration by supernova remnant shock waves, escape downstream of the shock and remain confined within the remnant until the shock slows down. During this time, the high-energy electrons suffer from radiative energy losses and the cosmic ray nuclei undergo nuclear fragmentations due to their interactions with the matter. Once the cosmic rays are released from the supernova remnants, they follow diffusive propagation in the Galaxy where they further suffer from radiative or fragmentation losses.

Thoudam, Satyendra; Hörandel, Jörg R.

2011-06-01

389

Development and use of the GREET model to estimate fuel-cycle energy use and emissions of various transportation technologies and fuels  

Microsoft Academic Search

This report documents the development and use of the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The model, developed in a spreadsheet format, estimates the full fuel- cycle emissions and energy use associated with various transportation fuels for light-duty vehicles. The model calculates fuel-cycle emissions of five criteria pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides,

1996-01-01

390

A novel thermally biased mechanical energy conversion cycle Ian M. McKinley, Sam Goljahi, Christopher S. Lynch, and Laurent Pilona)  

E-print Network

in the form of low grade waste heat.1 Methods for harvesting low grade waste heat include Stirling engines,2 organic Rankine cycles,3 and thermoelectric devices.4,5 Stirling engines and organic Rankine cycles convert thermal energy into mechanical energy. Thermoelectric devices make use of the Seebeck effect

Pilon, Laurent

391

The Baltic Sea Experiment (BALTEX): A European Contribution to the Investigation of the Energy and Water Cycle over a Large Drainage Basin  

Microsoft Academic Search

The Baltic Sea Experiment (BALTEX) is one of the five continental-scale experiments of the Global Energy and Water Cycle Experiment (GEWEX). More than 50 research groups from 14 European countries are participating in this project to measure and model the energy and water cycle over the large drainage basin of the Baltic Sea in northern Europe. BALTEX aims to provide

E. Raschke; J. Meywerk; K. Warrach; U. Andrea; S. Bergström; F. Beyrich; F. Bosveld; K. Bumke; C. Fortelius; L. P. Graham; S.-E. Gryning; S. Halldin; L. Hasse; M. Heikinheimo; H.-J. Isemer; D. Jacob; I. Jauja; K.-G. Karlsson; S. Keevallik; J. Koistinen; A. van Lammeren; U. Lass; J. Launianen; A. Lehmann; B. Liljebladh; M. Lobmeyr; W. Matthäus; T. Mengelkamp; D. B. Michelson; J. Napiórkowski; A. Omstedt; J. Piechura; B. Rockel; F. Rubel; E. Ruprecht; A.-S. Smedman; A. Stigebrandt

2001-01-01

392

A novel determination of density, temperature and symmetry energy for nuclear multi-fragmentation through primary fragment yield reconstruction  

E-print Network

For the first time primary hot isotope distributions are experimentally reconstructed in intermediate heavy ion collisions and used with antisymmetrized molecular dynamics (AMD) calculations to determine density, temperature and symmetry energy coefficient in a self-consistent manner. A kinematical focusing method is employed to reconstruct the primary hot fragment yield distributions for multifragmentation events observed in the reaction system $^{64}$Zn + $^{112}$Sn at 40 MeV/nucleon. The reconstructed yield distributions are in good agreement with the primary isotope distributions of AMD simulations. The experimentally extracted values of the symmetry energy coefficient relative to the temperature, $a_{sym}/T$, are compared with those of the AMD simulations with different density dependence of the symmetry energy term. The calculated $a_{sym}/T$ values changes according to the different interactions. By comparison of the experimental values of $a_{sym}/T$ with those of calculations, the density of the source at fragment formation was determined to be $\\rho /\\rho_{0} = (0.63 \\pm 0.03 )$. Using this density, the symmetry energy coefficient and the temperature are determined in a self-consistent manner as $a_{sym} = (24.7 \\pm 1.9) MeV$ and $T=(4.9 \\pm 0.2)$ MeV

W. Lin; X. Liu; M. R. D. Rodrigues; S. Kowalski; R. Wada; M. Huang; S. Zhang; Z. Chen; J. Wang; G. Q. Xiao; R. Han; Z. Jin; J. Liu; F. Shi; T. Keutgen; K. Hagel; M. Barbui; C. Bottosso; A. Bonasera; J. B. Natowitz; E. J. Kim; T. Materna; L. Qin; P. K. Sahu; K. J. Schmidt; S. Wuenschel; H. Zheng

2014-02-17

393

The University of Minnesota aquifer thermal energy storage (ATES) field test facility -- system description, aquifer characterization, and results of short-term test cycles  

SciTech Connect

Phase 1 of the Aquifer Thermal Energy Storage (ATES) Project at the University of Minnesota was to test the feasibility, and model, the ATES concept at temperatures above 100{degrees}C using a confined aquifer for the storage and recovery of hot water. Phase 1 included design, construction, and operation of a 5-MW thermal input/output field test facility (FTF) for four short-term ATES cycles (8 days each of heat injection, storage, and heat recover). Phase 1 was conducted from May 1980 to December 1983. This report describes the FTF, the Franconia-Ironton-Galesville (FIG) aquifer used for the test, and the four short-term ATES cycles. Heat recovery; operational experience; and thermal, chemical, hydrologic, and geologic effects are all included. The FTF consists of monitoring wells and the source and storage well doublet completed in the FIG aquifer with heat exchangers and a fixed-bed precipitator between the wells of the doublet. The FIG aquifer is highly layered and a really anisotropic. The upper Franconia and Ironton-Galesville parts of the aquifer, those parts screened, have hydraulic conductivities of {approximately}0.6 and {approximately}1.0 m/d, respectively. Primary ions in the ambient ground water are calcium and magnesium bicarbonate. Ambient temperature FIG ground water is saturated with respect to calcium/magnesium bicarbonate. Heating the ground water caused most of the dissolved calcium to precipitate out as calcium carbonate in the heat exchanger and precipitator. Silica, calcium, and magnesium were significantly higher in recovered water than in injected water, suggesting dissolution of some constituents of the aquifer during the cycles. Further work on the ground water chemistry is required to understand water-rock interactions.

Walton, M.; Hoyer, M.C.; Eisenreich, S.J.; Holm, N.L.; Holm, T.R.; Kanivetsky, R.; Jirsa, M.A.; Lee, H.C.; Lauer, J.L.; Miller, R.T.; Norton, J.L.; Runke, H. (Minnesota Geological Survey, St. Paul, MN (United States))

1991-06-01

394

A Sustainable Nuclear Fuel Cycle Based on Laser Inertial Fusion Energy  

SciTech Connect

The National Ignition Facility (NIF), a laser-based Inertial Confinement Fusion (ICF) experiment designed to achieve thermonuclear fusion ignition and burn in the laboratory, will soon be completed at the Lawrence Livermore National Laboratory. Experiments designed to accomplish the NIF's goal will commence in 2010, using laser energies of 1 to 1.3 MJ. Fusion yields of the order of 10 to 35 MJ are expected soon thereafter. They propose that a laser system capable of generating fusion yields of 35 to 75 MJ at 10 to 15 Hz (i.e., {approx} 350- to 1000-MW fusion and {approx} 1.3 to 3.6 x 10{sup 20} n/s), coupled to a compact subdritical fission blanket, could be used to generate several GW of thermal power (GWth) while avoiding carbon dioxide emissions, mitigating nuclear proliferation concerns and minimizing the concerns associated with nuclear safety and long-term nuclear waste disposition. this Laser Inertial Fusion Energy (LIFE) based system is a logical extension of the NIF laser and the yields expec ted from the early ignition experiments on NIF. The LIFE concept is a once-through,s elf-contained closed fuel cycle and would have the following characteristics: (1) eliminate the need for spent fuel chemical separation facilities; (4) maintain the fission blanket subcritical at all times (k{sub eff} < 0.90); and (5) minimize future requirements for deep underground geological waste repositories and minimize actinide content in the end-of-life nuclear waste below the Department of Energy's (DOE's) attractiveness Level E (the lowest). Options to burn natural or depleted U, Th, U/Th mixtures, Spent Nuclear Fuel (SNF) without chemical separations of weapons-attractive actinide streams, and excess weapons Pu or highly enriched U (HEU) are possible and under consideration. Because the fission blanket is always subcritical and decay heat removal is possible via passive mechanisms, the technology is inherently safe. Many technical challenges must be met, but a LIFE solution could provide a sustainable path for worldwide growth of nuclear powr for electricity production and hydrogen generation.

Moses, E; Diaz de la Rubia, T; Storm, E; Latkowski, J; Farmer, J; Abbott, R; Kramer, K; Peterson, P; Shaw, H; Lehman II, R

2009-05-22

395

Characterization of the new free-air primary standard for low-energy X-rays at CMI  

NASA Astrophysics Data System (ADS)

In 2011 a decision was made by Czech Metrology Institute to build a free-air ionization chamber (FAC) intended to be used as a primary standard of air kerma rate for low-energy X-rays (photon energy below 50 keV, including mammography X-ray qualities) in order to replace the currently used secondary ionization chamber and to decrease the uncertainty of air kerma reference value. In the period 2011-2012, the FAC has been designed, manufactured and put into operation. Its performance was tested using a calibrated secondary chamber and then by an informal comparison with a national primary standard of BEV (Austria). Physical characteristics of the FAC are described and individual correction factors are discussed focusing on computational methods utilized in their estimation. Summary of the correction factors with the uncertainty budget is presented.

Šolc, Jaroslav; Sochor, Vladimír

2014-11-01

396

Transient energy exchange between a primary structure and a set of oscillators: return time and apparent damping.  

PubMed

In this paper we examine the conditions that influence the return time, the time it takes before energy returns from a set of satellite oscillators attached to a primary structure. Two methods are presented to estimate the return time. One estimate is based on an analysis of the reaction force on a rigid base by a finite number of oscillators as compared with an infinite number of continuously distributed oscillators. The result gives a lower-bound estimate for the return time. A more accurate estimation results from considering the dynamic behavior of a set of oscillators as waves in a waveguide. Such an analogy explains energy flow between a primary structure and the oscillators in terms of pseudowaves and shows that a nonlinear frequency distribution of the oscillators leads to pseudodispersive waves. The resulting approximate expressions show the influence of the natural frequency distribution within the set of oscillators, and of their number, on the return time as compared with the asymptotic case of a continuous set with infinite oscillators. In the paper we also introduce a new method based on a Hilbert envelope to estimate the apparent damping loss factor of the primary structure during the return time considering transient energy flow from the primary structure before any energy reflects back from the attached oscillators. The expressions developed for return time and damping factor show close agreement with direct numerical simulations. The paper concludes with a discussion of the return time and its relation to apparent damping and optimum frequency distribution within a set of oscillators that maximize these quantities. PMID:15000181

Carcaterra, Antonio; Akay, Adnan

2004-02-01

397

Pipe break testing of primary loop piping similar to the Department of Energy's new production reactor-heavy water reactor  

Microsoft Academic Search

This paper provides information about and results from specific tests completed at Oak Ridge National Laboratory (ORNL) in support of the Department of Energy's (DOE's) new production reactor-heavy water reactor (NPR-HWR) program. The paper also provides detailed analytical studies completed by Battelle Columbus Laboratory. All of this information is presented in a demonstration that the primary piping of the NPR-HWR,

A. B. Poole; J. A. Clinard; R. L. Battiste; W. R. Hendrich

1995-01-01

398

Charge composition of high energy heavy primary cosmic ray nuclei. Ph.D. Thesis - Catholic Univ. of Am.  

NASA Technical Reports Server (NTRS)

A detailed study of the charge composition of primary cosmic radiation for about 5000 charged nuclei from neon to iron with energies greater than 1.16 GeV/nucleon is presented. Values are obtained after corrections were made for detector dependences, atmospheric attenuation, and solar modulation. New values of 38.5, 32.4, 23.7, and 16.8 g/sq cm for the attenuation mean free paths in air for the same charge groups are presented.

Price, R. D.

1974-01-01

399

Life-cycle fossil energy consumption and greenhouse gas emissions of bioderived chemicals and their conventional counterparts.  

PubMed

Biomass-derived chemical products may offer reduced environmental impacts compared to their fossil-derived counterparts and could improve profit margins at biorefineries when coproduced with higher-volume, lower-profit margin biofuels. It is important to assess on a life-cycle basis the energy and environmental impacts of these bioproducts as compared to conventional, fossil-derived products. We undertook a life-cycle analysis of eight bioproducts produced from either algal-derived glycerol or corn stover-derived sugars. Selected on the basis of technology readiness and market potential, the bioproducts are propylene glycol, 1,3-propanediol, 3-hydroxypropionic acid, acrylic acid, polyethylene, succinic acid, isobutanol, and 1,4-butanediol. We developed process simulations to obtain energy and material flows in the production of each bioproduct and examined sensitivity of these flows to process design assumptions. Conversion process data for fossil-derived products were based on the literature. Conversion process data were combined with upstream parameters in the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model to generate life-cycle greenhouse gas (GHG) emissions and fossil energy consumption (FEC) for each bioproduct and its corresponding petroleum-derived product. The bioproducts uniformly offer GHG emissions reductions compared to their fossil counterparts ranging from 39 to 86% on a cradle-to-grave basis. Similarly, FEC was lower for bioproducts than for conventional products. PMID:25380298

Adom, Felix; Dunn, Jennifer B; Han, Jeongwoo; Sather, Norm

2014-12-16

400

Arabidopsis mutants define a central role for the xanthophyll cycle in the regulation of photosynthetic energy conversion.  

PubMed Central

A conserved regulatory mechanism protects plants against the potentially damaging effects of excessive light. Nearly all photosynthetic eukaryotes are able to dissipate excess absorbed light energy in a process that involves xanthophyll pigments. To dissect the role of xanthophylls in photoprotective energy dissipation in vivo, we isolated Arabidopsis xanthophyll cycle mutants by screening for altered nonphotochemical quenching of chlorophyll fluorescence. The npq1 mutants are unable to convert violaxanthin to zeaxanthin in excessive light, whereas the npq2 mutants accumulate zeaxanthin constitutively. The npq2 mutants are new alleles of aba1, the zeaxanthin epoxidase gene. The high levels of zeaxanthin in npq2 affected the kinetics of induction and relaxation but not the extent of nonphotochemical quenching. Genetic mapping, DNA sequencing, and complementation of npq1 demonstrated that this mutation affects the structural gene encoding violaxanthin deepoxidase. The npq1 mutant exhibited greatly reduced nonphotochemical quenching, demonstrating that violaxanthin deepoxidation is required for the bulk of rapidly reversible nonphotochemical quenching in Arabidopsis. Altered regulation of photosynthetic energy conversion in npq1 was associated with increased sensitivity to photoinhibition. These results, in conjunction with the analysis of npq mutants of Chlamydomonas, suggest that the role of the xanthophyll cycle in nonphotochemical quenching has been conserved, although different photosynthetic eukaryotes rely on the xanthophyll cycle to different extents for the dissipation of excess absorbed light energy. PMID:9668132

Niyogi, K K; Grossman, A R; Björkman, O

1998-01-01

401

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 5: Combined gas-steam turbine cycles. [energy conversion efficiency in electric power plants  

NASA Technical Reports Server (NTRS)

The energy conversion efficiency of gas-steam turbine cycles was investigated for selected combined cycle power plants. Results indicate that it is possible for combined cycle gas-steam turbine power plants to have efficiencies several point higher than conventional steam plants. Induction of low pressure steam into the steam turbine is shown to improve the plant efficiency. Post firing of the boiler of a high temperature combined cycle plant is found to increase net power but to worsen efficiency. A gas turbine pressure ratio of 12 to 1 was found to be close to optimum at all gas turbine inlet temperatures that were studied. The coal using combined cycle plant with an integrated low-Btu gasifier was calculated to have a plant efficiency of 43.6%, a capitalization of $497/kW, and a cost of electricity of 6.75 mills/MJ (24.3 mills/kwh). This combined cycle plant should be considered for base load power generation.

Amos, D. J.; Foster-Pegg, R. W.; Lee, R. M.

1976-01-01

402

Recapitulation of the Sexual Cycle of the Primary Fungal Pathogen Cryptococcus neoformans var. gattii: Implications for an Outbreak on Vancouver Island, Canada  

Microsoft Academic Search

Cryptococcus neoformans is a human fungal pathogen that exists as three distinct varieties or sibling species: the predominantly opportunistic pathogens C. neoformans var. neoformans (serotype D) and C. neoformans var. grubii (serotype A) and the primary pathogen C. neoformans var. gattii (serotypes B and C). While serotypes A and D are cosmopolitan, serotypes B and C are typically restricted to

James A. Fraser; Ryan L. Subaran; Connie B. Nichols; Joseph Heitman

2003-01-01

403

77 FR 18272 - Uranium Enrichment Fuel Cycle Facility Inspection Reports Regarding Louisiana Energy Services LLC...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Docket No. 70-3103; NRC-2010-0264] Uranium Enrichment Fuel Cycle Facility Inspection...1954, as amended. The introduction of uranium hexafluoride into any module of the...Commission. Brian W. Smith, Chief, Uranium Enrichment Branch, Division of Fuel...

2012-03-27

404

78 FR 23312 - Uranium Enrichment Fuel Cycle Inspection Reports Regarding Louisiana Energy Services, National...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Docket No. 70-3103; NRC-2010-0264] Uranium Enrichment Fuel Cycle Inspection Reports...and has authorized the introduction of uranium hexafluoride (UF 6 ) into cascades...Commission. Brian W. Smith, Chief, Uranium Enrichment Branch, Division of Fuel...

2013-04-18

405

Life cycle energy and greenhouse gas emissions for an ethanol production process based on blue-green algae.  

PubMed

Ethanol can be produced via an intracellular photosynthetic process in cyanobacteria (blue-green algae), excreted through the cell walls, collected from closed photobioreactors as a dilute ethanol-in-water solution, and purified to fuel grade ethanol. This sequence forms the basis for a biofuel production process that is currently being examined for its commercial potential. In this paper, we calculate the life cycle energy and greenhouse gas emissions for three different system scenarios for this proposed ethanol production process, using process simulations and thermodynamic calculations. The energy required for ethanol separation increases rapidly for low initial concentrations of ethanol, and, unlike other biofuel systems, there is little waste biomass available to provide process heat and electricity to offset those energy requirements. The ethanol purification process is a major consumer of energy and a significant contributor to the carbon footprint. With a lead scenario based on a natural-gas-fueled combined heat and power system to provide process electricity and extra heat and conservative assumptions around the ethanol separation process, the net life cycle energy consumption, excluding photosynthesis, ranges from 0.55 MJ/MJ(EtOH) down to 0.20 MJ/ MJ(EtOH), and the net life cycle greenhouse gas emissions range from 29.8 g CO?e/MJ(EtOH) down to 12.3 g CO?e/MJ(EtOH) for initial ethanol concentrations from 0.5 wt % to 5 wt %. In comparison to gasoline, these predicted values represent 67% and 87% reductions in the carbon footprint for this ethanol fuel on a energy equivalent basis. Energy consumption and greenhouse gas emissions can be further reduced via employment of higher efficiency heat exchangers in ethanol purification and/ or with use of solar thermal for some of the process heat. PMID:20968295

Luo, Dexin; Hu, Zushou; Choi, Dong Gu; Thomas, Valerie M; Realff, Matthew J; Chance, Ronald R

2010-11-15

406

Energy and exergy analysis of an efficient organic Rankine cycle for low temperature power generation  

Microsoft Academic Search

This paper presents and discusses the performance of an advanced Organic Rankine Cycle (ORC) using a heated chemical instead of steam as found in the typical Rankine Cycle. Chemicals used are the new quaternary refrigerant mixtures that are environmentally-friendly and have efficient thermodynamic properties at low and medium waste heat temperatures compared to other organic and non-organic fluids.This mixture boils

S. M. Sami

2008-01-01

407

Energy And Glucose Pathways In Thiamine Deficient Primary Rat Brain Microvascular Endothelial Cells  

Microsoft Academic Search

Thiamine deficiency (TD) results in lactate acidosis, which is associated with neurodegeneration. The aim of this study was to investigate this alteration in primary rat brain endothelia. Spectrophotometric analysis of culture media re- vealed that only a higher concentration of pyrithiamine, which accelerates the in- tracellular blocking of thiamine, significantly elevated the lactate level and lactate dehydrogenase activity within 7

D. Ham; B. Karska-Wysocki

408

On the Low Energy Decrease in Galactic Cosmic Ray Secondary/Primary Ratios  

E-print Network

/primary ratios such as B/C and (Sc+Ti+V)/Fe are commonly used to determine the mean amount of interstellar material through which cosmic rays travel before escaping from the Galaxy (esc). These ratios are observed acceleration of cosmic rays as they pass through the interstellar medium. We consider two possible explanations

Davis, Andrew J.

409

A new one-dimensional simple energy balance and carbon cycle coupled model for global warming simulation  

Microsoft Academic Search

Global warming and accompanying climate change may be caused by an increase in atmospheric greenhouse gasses generated by\\u000a anthropogenic activities. In order to supply such a mechanism of global warming with a quantitative underpinning, we need\\u000a to understand the multifaceted roles of the Earth's energy balance and material cycles. In this study, we propose a new one-dimensional\\u000a simple Earth system

Kazutaka Murakami; Takahiro Sasai; Yasushi Yamaguchi

2010-01-01

410

Analysis of a novel solar energy-powered Rankine cycle for combined power and heat generation using supercritical carbon dioxide  

Microsoft Academic Search

Theoretical analysis of a solar energy-powered Rankine thermodynamic cycle utilizing an innovative new concept, which uses supercritical carbon dioxide as a working fluid, is presented. In this system, a truly ‘natural’ working fluid, carbon dioxide, is utilized to generate firstly electricity power and secondly high-grade heat power and low-grade heat power. The uniqueness of the system is in the way

X. R. Zhang; H. Yamaguchi; D. Uneno; K. Fujima; M. Enomoto; N. Sawada

2006-01-01

411

Comparative Life Cycle Assessments of Lignocellulosic and Algae Biomass Conversion to Various Energy Products through Different Pathways  

Microsoft Academic Search

Bioenergy has the potential to reduce the world's dependence on fossil fuels, and to decrease the CO2 emissions due to fossil combustion. Lignocellulosic and algae biomass have been presented as promising feedstocks for bioenergy production.\\u000aIn this study, a comparative Life Cycle Assessment (LCA) has been developed to evaluate the environmental impacts associated with different energy products via different routes

Maria Juliana Pinilla

2011-01-01

412

Biogeochemical cycling of carbon, water, energy, trace gases, and aerosols in Amazonia: The LBA-EUSTACH experiments  

Microsoft Academic Search

The biogeochemical cycling of carbon, water, energy, aerosols, and trace gases in the Amazon Basin was investigated in the project European Studies on Trace Gases and Atmospheric Chemistry as a Contribution to the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA-EUSTACH). We present an overview of the design of the project, the measurement sites and methods, and the meteorological conditions during the

M. O. Andreae; P. Artaxo; C. Brandão; F. E. Carswell; P. Ciccioli; A. L. da Costa; A. D. Culf; J. L. Esteves; J. H. C. Gash; J. Grace; P. Kabat; J. Lelieveld; Y. Malhi; A. O. Manzi; F. X. Meixner; A. D. Nobre; C. A. Nobre; M. d. L. P. Ruivo; M. A. F. da Silva-Dias; P. Stefani; R. Valentini; J. von Jouanne; M. J. Waterloo

2002-01-01

413

Life-Cycle Assessment of Energy Use and Greenhouse Gas Emissions of Soybean-Derived Biodiesel and Renewable Fuels  

SciTech Connect

In this study, we used Argonne National Laboratory's Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model to assess the life-cycle energy and greenhouse gas (GHG) emission impacts of four soybean-derived fuels: biodiesel fuel produced via transesterification, two renewable diesel fuels (I and II) produced from different hydrogenation processes, and renewable gasoline produced from catalytic cracking. Five approaches were employed to allocate the coproducts: a displacement approach; two allocation approaches, one based on the energy value and the other based on the market value; and two hybrid approaches that integrated the displacement and allocation methods. The relative rankings of soybean-based fuels in terms of energy and environmental impacts were different under the different approaches, and the reasons were analyzed. Results from the five allocation approaches showed that although the production and combustion of soybean-based fuels might increase total energy use, they could have significant benefits in reducing fossil energy use (>52%), petroleum use (>88%), and GHG emissions (>57%) relative to petroleum fuels. This study emphasized the importance of the methods used to deal with coproduct issues and provided a comprehensive solution for conducting a life-cycle assessment of fuel pathways with multiple coproducts.

Huo, H.; Wang, M.; Bloyd, C.; Putsche, V.

2009-01-01

414

Simulations of Water and Energy Cycles over the Congo and Upper Blue Nile basins by IPCC GCMs  

NASA Astrophysics Data System (ADS)

The simulations of the hydrological cycle in general circulation models (GCMs) are characterized by a significant degree of uncertainty. This uncertainty is reflected in the wide range of IPCC (Intergovernmental Panel on Climate Change) GCMs predictions of future changes in the hydrological cycle, particularly over major African basins. Here, we explore the relations between the surface radiation and hydrological cycle within 17 of the IPCC GCMs over the Congo and Upper Blue Nile (UBN) basins. Most GCMs overestimate the hydrological cycle over the basins compared to observations. This overestimation is associated with excess net surface radiation, attributed to an overestimation of downward shortwave radiation and an underestimation of upward longwave radiation at the surface compared to observations. In order to verify if the overestimation of the net radiation is a systematic problem in these models for other regions, the net surface radiation over the Sahara Desert is also investigated. Although the Sahara Desert has a different climatic conditions compared to the studied basins, but the persistent overestimation of the net surface radiation for all models over this region suggests that models tend to overestimate the net surface radiation at least over the majority of the African continent. Our results also show that the increase in horizontal resolution of GCMs results in a better simulations of the hydrological cycle. In addition, the absence of the radiation effects of mineral aerosols, biomass burning and low negative cloud feedback for most of the models can be responsible of the overestimation of both the energy and hydrological cycles over the studied regions.

Eltahir, E. A.; Siam, M.

2012-12-01

415

Rock Cycle  

NSDL National Science Digital Library

The Rock Cycle SciPack explores different kinds and categories of rocks, the major processes through which they form and the cyclical nature of the formation and transformation of rock materials. The focus is on topics supporting Standards and Benchmarks related to the rock cycle as part of the transfer and transformation of matter and energy in Earth's system as well as a sense of the time scales involved and how rocks provide information about their own development and the history of Earth.In addition to comprehensive inquiry-based learning materials tied to Science Education Standards and Benchmarks, the SciPack includes the following additional components:? Pedagogical Implications section addressing common misconceptions, teaching resources and strand maps linking grade band appropriate content to standards. ? Access to one-on-one support via e-mail to content "Wizards".? Final Assessment which can be used to certify mastery of the concepts.Learning Outcomes:Rock Cycle: Categories by Process? List the three different types of rock. ? Make appropriate observations about rocks (e.g. describe rock composition and texture).? Make appropriate observations about the general environments in which the rocks formed.Rock Cycle: Environments of Formation? Realize that different rocks have specific origins, and that they are the product of any number of processes.? Identify the processes through which igneous, sedimentary, and metamorphic rock form.? Explain the role of intermediary materials such as sediment and magma in the formation of different kinds of rock.? Provide an overarching description of the steps in the rock cycle, the formation of sedimentary rock, the re-forming of rock by heat and pressure, and the process by which re-formed rock can return to the surface.Rock Cycle: Cycling? Recognize the formation and transformation processes as part of a continuing cycle.? Identify that while the form and location of different rocks change over time, the amount of material and the distribution among the elements remains constant.? Explain the different processes or paths that each type of rock may take in the rock cycle.Rock Cycle: Earth's Autobiography? State the amount of time over which the rock cycle has been in operation (4 billion years rather than 40 million or 400 million).? Recognize that the processes at work in the present are the same as those at work in the distant past.? Describe how rock formations and characteristics can be used to determine how different rock formed, making appropriate interpretations about the source of the rock, history and processes, and the environment of formation.? Describe how rocks provide a history of the changing surface of Earth and its lifeforms.

National Science Teachers Association (NSTA)

2007-03-21

416

Sensitivity of YAC to measure the light-component spectrum of primary cosmic rays at the ‘knee’ energies  

NASA Astrophysics Data System (ADS)

A new air-shower core-detector array (YAC: Yangbajing air-shower Core-detector array) has been developed to measure the primary cosmic-ray composition at the ‘knee’ energies in Tibet, China, focusing mainly on the light components. The prototype experiment (YAC-I) consisting of 16 detectors has been constructed and operated at Yangbajing (4300 m a.s.l.) in Tibet since May 2009. YAC-I is installed in the Tibet-III AS array and operates together. In this paper, we performed a Monte Carlo simulation to check the sensitivity of the YAC-I+Tibet-III array to the cosmic-ray light component of cosmic rays around the knee energies, taking account of the observation conditions of the actual YAC-I+Tibet-III array. The selection of light component from others was made by use of an artificial neural network. The simulation shows that the light-component spectrum estimated by our methods can well reproduce the input ones within 10% error, and there will be about 30% systematic errors mostly induced by the primary and interaction models used. It is found that the full-scale YAC and the Tibet-III array is powerful to study the cosmic-ray composition, in particular, to obtain the energy spectra of protons and helium nuclei around the knee energies.

Zhai, L. M.; Huang, J.; Chen, D.; Shibata, M.; Katayose, Y.; Zhang, Ying; Liu, J. S.; Chen, Xu; Hu, X. B.; Lin, Y. H.

2015-04-01

417

Dynamic responses and mitigation of limit cycle oscillations in Van der Pol-Duffing oscillator with nonlinear energy sink  

NASA Astrophysics Data System (ADS)

The paper considers dynamics of Van der Pol-Duffing (VdPD) oscillator with attached nonlinear energy sink. Due to a cubic nonlinearity of the VdPD oscillator, a frequency of oscillations near the unstable origin strongly differs from the frequency of limit cycle oscillations (LCO). The paper demonstrates that, despite the strong nonlinearity of the model system, one can efficiently describe the dynamics with a combination of averaging and multiple scales methods. Global structure of possible response regimes is revealed. It is also demonstrated that the nonlinear energy sink can efficiently control and mitigate the undesired LCOs in this system.

Domany, E.; Gendelman, O. V.

2013-10-01

418

Development of energy performance benchmarks and building energy ratings for non-domestic buildings: An example for Irish primary schools  

Microsoft Academic Search

The EU Member States are in the process of implementing energy rating procedures for buildings. For non-domestic buildings in particular, devising a robust and cost effective energy rating method is not a simple task. The situation becomes more complicated where countries do not have a tradition of performing energy calculations or undertaking energy measurements in buildings.This paper outlines a methodology

Patxi Hernandez; Kevin Burke; J. Owen Lewis

2008-01-01

419

The Oxygen Cycle.  

ERIC Educational Resources Information Center

Produced for primary grades, this booklet provides study of the oxygen-carbon dioxide cycle in nature. Line drawings, a minimum amount of narrative, and a glossary of terms make up its content. The booklet is designed to be used as reading material, a coloring book, or for dramatic arts with students acting out parts of the cycle. This work was…

Swant, Gary D.

420

Power Plant Cycling Costs  

SciTech Connect

This report provides a detailed review of the most up to date data available on power plant cycling costs. The primary objective of this report is to increase awareness of power plant cycling cost, the use of these costs in renewable integration studies and to stimulate debate between policymakers, system dispatchers, plant personnel and power utilities.

Kumar, N.; Besuner, P.; Lefton, S.; Agan, D.; Hilleman, D.

2012-07-01

421

Nuclear energy in Europe: uranium flow modeling and fuel cycle scenario trade-offs from a sustainability perspective.  

PubMed

The European nuclear fuel cycle (covering the EU-27, Switzerland and Ukraine) was modeled using material flow analysis (MFA).The analysis was based on publicly available data from nuclear energy agencies and industries, national trade offices, and nongovernmental organizations. Military uranium was not considered due to lack of accessible data. Nuclear fuel cycle scenarios varying spent fuel reprocessing, depleted uranium re-enrichment, enrichment assays, and use of fast neutron reactors, were established. They were then assessed according to environmental, economic and social criteria such as resource depletion, waste production, chemical and radiation emissions, costs, and proliferation risks. The most preferable scenario in the short term is a combination of reduced tails assay and enrichment grade, allowing a 17.9% reduction of uranium demand without significantly increasing environmental, economic, or social risks. In the long term, fast reactors could theoretically achieve a 99.4% decrease in uranium demand and nuclear waste production. However, this involves important costs and proliferation risks. Increasing material efficiency is not systematically correlated with the reduction of other risks. This suggests that an overall optimization of the nuclear fuel cycle is difficult to obtain. Therefore, criteria must be weighted according to stakeholder interests in order to determine the most sustainable solution. This paper models the flows of uranium and associated materials in Europe, and provides a decision support tool for identifying the trade-offs of the alternative nuclear fuel cycles considered. PMID:21275398

Tendall, Danielle M; Binder, Claudia R

2011-03-15

422

Life cycle assessment of energy self-sufficiency systems based on agricultural residues for organic arable farms.  

PubMed

The agricultural industry today consumes large amounts of fossil fuels. This study used consequential life cycle assessment (LCA) to analyse two potential energy self-sufficient systems for organic arable farms, based on agricultural residues. The analysis focused on energy balance, resource use and greenhouse gas (GHG) emissions. A scenario based on straw was found to require straw harvest from 25% of the farm area; 45% of the total energy produced from the straw was required for energy carrier production and GHG emissions were reduced by 9% compared with a fossil fuel-based reference scenario. In a scenario based on anaerobic digestion of ley, the corresponding figures were 13%, 24% and 35%. The final result was sensitive to assumptions regarding, e.g., soil carbon content and handling of by-products. PMID:20970998

Kimming, M; Sundberg, C; Nordberg, A; Baky, A; Bernesson, S; Norén, O; Hansson, P-A

2011-01-01

423

Energy efficiency and environmental performance of bioethanol production from sweet sorghum stem based on life cycle analysis.  

PubMed

Life cycle analysis method was used to evaluate the energy efficiency and environmental performance of bioethanol production from sweet sorghum stem in China. The scope covers three units, including plant cultivation, feedstock transport, and bioethanol conversion. Results show that the net energy ratio was 1.56 and the net energy gain was 8.37 MJ/L. Human toxicity was identified as the most significant negative environmental impact, followed by eutrophication and acidification. Steam generation in the bioethanol conversion unit contributed 82.28% and 48.26% to total human toxicity and acidification potential, respectively. Fertilizers loss from farmland represented 67.23% of total eutrophication potential. The results were significantly affected by the inventory allocation methods, vinasse reusing approaches, and feedstock yields. Reusing vinasse as fuel for steam generation and better cultivation practice to control fertilizer loss could significantly contribute to enhance the energy efficiency and environmental performance of bioethanol production from sweet sorghum stem. PMID:24787319

Wang, Mingxin; Chen, Yahui; Xia, Xunfeng; Li, Jun; Liu, Jianguo

2014-07-01

424

Research in Support of the Use of Rankine Cycle Energy Conversion Systems for Space Power and Propulsion  

NASA Technical Reports Server (NTRS)

This is the report of a Scientific Working Group (SWG) formed by NASA to determine the feasibility of using a liquid metal cooled nuclear reactor and Rankine energy conversion cycle for dual purpose power and propulsion in space. This is a high level technical report which is intended for use by NASA management in program planning. The SWG was composed of a team of specialists in nuclear energy and multiphase flow and heat transfer technology from academia, national laboratories, NASA and industry. The SWG has identified the key technology issues that need to be addressed and have recommended an integrated short term (approx. 2 years) and a long term (approx. 10 year) research and development (R&D) program to qualify a Rankine cycle power plant for use in space. This research is ultimately intended to give NASA and its contractors the ability to reliably predict both steady and transient multiphase flow and heat transfer phenomena at reduced gravity, so they can analyze and optimize designs and scale-up experimental data on Rankine cycle components and systems. In addition, some of these results should also be useful for the analysis and design of various multiphase life support and thermal management systems being considered by NASA.

Lahey, Richard T., Jr.; Dhir, Vijay

2004-01-01

425

Optimal Life Cycle Cost Design for an Energy Efficient Manufacturing Facility  

E-print Network

Over the past twelve years, Texas Instruments has developed extensive energy management programs that have enabled them to reduce energy usage by 42%. Typically, these reductions have been a result of the application of microprocessor based energy...

Thompson, C. T.; Beach, W. P.

1985-01-01

426

Altered energy status of primary cerebellar granule neuronal cultures from rats exposed to lead in the pre- and neonatal period.  

PubMed

This paper examines the effect of pre- and neonatal exposure of rats to lead (0.1% lead acetate in drinking water, resulting in rat offspring whole blood lead concentration (Pb-B) 4?g/dL) on the energy status of neuronal mitochondria by measuring changes in ATP, ADP, AMP, adenosine, TAN concentration, adenylate energy charge value (AEC) and mitochondrial membrane potential in primary cerebellar granule neurons (CGC) in dissociated cultures. Fluorescence studies were performed to imaging and evaluate mitochondria mass, mitochondrial membrane potential, intracellular and mitochondrial reactive oxygen species (ROS) production. The Na(+)/K(+) ATPase activity in intact CGC was measured spectrophotometrically. Our data shows that pre- and neonatal exposure of rats to Pb, even below the threshold of whole blood Pb value considered safe for people, affects the energy status of cultured primary cerebellar granule neurons through a decrease in ATP and TAN concentrations and AEC value, inhibition of Na(+)/K(+) ATPase, and increase in intracellular and mitochondrial ROS concentration. These observations suggest that even these low levels of Pb are likely to induce important alterations in neuronal function that could play a role in neurodegeneration. PMID:21108985

Baranowska-Bosiacka, I; Gutowska, I; Marchetti, C; Rutkowska, M; Marchlewicz, M; Kolasa, A; Prokopowicz, A; Wiernicki, I; Piotrowska, K; Ba?kiewicz, M; Safranow, K; Wiszniewska, B; Chlubek, D

2011-02-01

427

HOW THE LEED VENTILATION CREDIT IMPACTS ENERGY CONSUMPTION OF GSHP SYSTEMS A CASE STUDY FOR PRIMARY SCHOOLS  

SciTech Connect

This paper presents a study on the impacts of increased outdoor air (OA) ventilation on the performance of ground-source heat pump (GSHP) systems that heat and cool typical primary schools. Four locations Phoenix, Miami, Seattle, and Chicago are selected in this study to represent different climate zones in the United States. eQUEST, an integrated building and HVAC system energy analysis program, is used to simulate a typical primary school and the GSHP system at the four locations with minimum and 30% more than minimum OA ventilation. The simulation results show that, without an energy recovery ventilator, the 30% more OA ventilation results in an 8.0 13.3% increase in total GSHP system energy consumption at the four locations. The peak heating and cooling loads increase by 20.2 30% and 14.9 18.4%, respectively, at the four locations. The load imbalance of the ground heat exchanger is increased in hot climates but reduced in mild and cold climates.

Liu, Xiaobing [ORNL] [ORNL

2011-01-01

428

The Organic Rankine Cycle System, Its Application to Extract Energy From Low Temperature Waste Heat  

E-print Network

expanded System is useless if that condition is never realized 4 vapor (Btu/Lb) in operation or its availability is low. 2 = dimensional constant = .1852 (Bt~ 1!L) REFERENCES K 1 ft Lb ( 1) Adrian W. McAnneny, "Binary Cycle Gas Fired .~p...

Sawyer, R. H.; Ichikawa, S.

1980-01-01