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1

Life Cycle Primary Energy and Carbon Analysis of Recovering ...  

Treesearch

Source: In: Proceedings , Instruments for Green Futures Markets, American Center for Life ... wood for reuse in a new house affects energy and greenhouse gas emissions. ... GWP increased by two to four times when including biogenic CO2.

2

Annual Cycle Energy System.  

National Technical Information Service (NTIS)

The design, operation, and performance of the Annual Cycle Energy System (ACES) which provides space heating and cooling and hot water for an experimental house in Knoxville, TN are described. ACES is basically an assisted heat pump with energy storage in...

R. E. Minturn

1979-01-01

3

A Solar Energy Cycle  

NSDL National Science Digital Library

In sixth grade, students understand that Earth gets visible light from the Sun, but studentsmay also believe the Earth gets heat from the Sun. This last part is incorrect because the Sun is too far from the Earth to heat it directly. So, how does the Sun heat the Earth? When light strikes an object, it can be reflected or absorbed. Absorbed light usually increases the energy in an object, which causes the object to heat up. The following solar energy learning cycle (Exploration, Term Introduction, and Concept Application) was developed to help sixth-grade students better understand the concept. This learning cycle also facilitates technology integration and provides students opportunities to construct and generate experiments with scientifically testable questions. The cycle takes six 50-minute periods.

Childs, Gregory

2007-03-01

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.

2012-01-01

5

NEED Project: Primary Energy Activities  

NSDL National Science Digital Library

This free activity booklet for Grades 2-4 accompanies the NEED Project's Primary Science of Energy curriculum materials. It contains an array of multisensory games, songs, graphics, and seat activities to accompany the energy instructional unit outlined in the NEED Teacher's Guide for Primary Energy. You'll also find printable assessments with answer keys and a student self-evaluation. The NEED energy curriculum is noteworthy because students are first 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). See Related Materials for a link to the Teacher's Guide for this unit. 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.

2013-04-04

6

The NASA Energy and Water cycle Study  

NASA Astrophysics Data System (ADS)

In 2003 NASA established the NASA Energy and Water-cycle Study (NEWS), whose long-term grand challenge is to document and enable improved, observationally based, predictions of water and energy cycle consequences of Earth system variability and change. Over the past two years, the NEWS team has been working on how to refine its approach to science integration . To this end, NEWS has created four working groups that identify integration needs and make the needed connections to partner and coordinate with water & energy cycle research and application activities going on at other organizations within NASA, nationally, and internationally. The four groups are: (1) Drought & Flood Extremes- including water and energy aspects of abrupt climate change, (2) Evaporation & Latent Heating - including both land and ocean, (3) Water and Energy Cycle Climatology - to exploit and influence evolving observing systems, and (4) Modeling & Water Cycle Prediction - foster interaction with the global modeling community. The first phase of NEWS focuses on the first coordinated attempt to describe the complete global energy and water cycle using existing and forthcoming satellite and ground based observations, and laying the foundation for essential NEWS developments in model representations of atmospheric energy and water exchange processes. This comprehensive energy and water data analysis program must exploit crucial datasets, some still requiring complete re-processing, and new satellite measurements. These data products will then be evaluated for accuracy and consistency, in part by using them in the first diagnosis of the weather-scale (space and time) variations of the global energy and water cycle over the past one-two decades. The primary objective is to ensure that results of this analysis effort serve as a recognized data basis to compare with corresponding climate statistics produced by existing climate models, quantify systematic deficiencies, and identify needed improvements. The data records to be produced through these efforts are mandatory for developing and validating models that meet NEWS scientific requirements. At the same time, NEWS implementation calls for the development of radically new model representations of energy and water exchange processes that resolve significant process scales and spatial variability in ground boundary conditions. Such process-resolving models may be first constructed as independent stand-alone modules that can be tested against ad hoc field measurements and systematic observations at selected experimental sites. At a later stage, the codes may be simplified through statistical sampling of process-scale variables or otherwise reduced to generate integrated fluxes representative of each grid-element in a climate model. Finally, the implementation plan calls for broad exploration of potential new observing techniques concerning all aspects of the energy and water cycle, and initiating relevant technical feasibility and scientific benefit studies.

Houser, P. R.; Entin, J. K.; Schiffer, R. A.; Belvedere, D. R.

2010-12-01

7

SAFE gas turbine cycle primary heat exchangers  

NASA Astrophysics Data System (ADS)

Los Alamos National Laboratory and Marshall Space Flight Center are jointly developing two modular heat pipe heat exchangers, collectively named FIGMENT (Fission Inert Gas Metal Exchanger for Non-nuclear Testing). The FIGMENT heat exchangers are designed to transfer power from the SAFE nuclear reactor cores to gas turbine energy converters. A stainless steel prototype heat exchanger will be built during 2002 in preparation for the construction of a larger refractory metal version. Two promising FIGMENT stainless steel heat exchanger concepts are reviewed here. .

Reid, Robert S.; Kapernick, Richard J.

2002-01-01

8

NEED Project: Primary Energy Carnival  

NSDL National Science Digital Library

This free booklet for Grades 2-5 provides nine games designed to reinforce learning about the ten major energy sources, renewable vs. nonrenewable energy, and ways we use resources to power human activities. Kids will play Energy Bingo, Energy Pictionary, matching and memory games, and solve energy-related math problems to earn Energy Bucks. It's completely turn-key -- just print and mount on cardboard. This resource accompanies the NEED Project's Primary Science of Energy curriculum materials. See Related Materials for a link to the Teacher's Guide that accompanies this resource. 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.

2013-04-05

9

Adaptive duty cycling for energy harvesting systems  

Microsoft Academic Search

Harvesting energy from the environment is feasible in many applications to ameliorate the energy limitations in sensor networks. In this paper, we present an adaptive duty cycling algorithm that allows energy harvesting sensor nodes to autonomously adjust their duty cycle according to the energy availability in the environment. The algorithm has three objectives, namely (a) achieving energy neutral operation, i.e.,

Jason Hsu; Sadaf Zahedi; Aman Kansal; Mani B. Srivastava; Vijay Raghunathan

2006-01-01

10

Optimizing the dielectric elastomer energy harvesting cycles  

Microsoft Academic Search

From an electrical point of view dielectric elastomers are variable capacitors, which are frequently used as generators. The focus of this paper is to show, how the maximum energy gain can be realized by realizing an innovative current waveform to charge and discharge the polymer. Several energy harvesting cycles are introduced and their energy output compared. The most promising cycle

Rick van Kessel; B. Czech; P. Bauer; J. A. Ferreira

2010-01-01

11

Comparison of the dielectric electroactive polymer generator energy harvesting cycles  

NASA Astrophysics Data System (ADS)

The Dielectric ElectroActive Polymer (DEAP) generator energy harvesting cycles have been in the spotlight of the scientific interest for the past few years. Indeed, several articles have demonstrated thorough and comprehensive comparisons of the generator fundamental energy harvesting cycles, namely Constant Charge (CC), Constant Voltage (CV) and Constant E-field (CE), based on average theoretical models. Yet, it has not been possible until present to validate the outcome of those comparisons via respective experimental results. In this paper, all three primary energy harvesting cycles are experimentally compared, based upon the coupling of a DEAP generator with a bidirectional non-isolated power electronic converter, by means of energy gain, energy harvesting efficiency and energy conversion efficiency.

Dimopoulos, Emmanouil; Trintis, Ionut; Munk-Nielsen, Stig

2013-04-01

12

Cell cycle analysis of primary sponge cell cultures.  

PubMed

Proliferation of sponge cells is generally measured via cell counts or viability assays. However, more insight into the proliferative state of a sponge cell population can be obtained from the distribution of the cells over the different phases of the cell cycle. Cell cycle distribution of sponge cells was measured via flow cytometry after staining the DNA with propidium iodide. The five sponges studied in this paper all showed a large fraction of cells in G1/G0 compared to G2/M and S, indicating that cells were not actively dividing. In addition, some sponges also showed a large apoptotic fraction, indicating cell death. Additional apoptosis measurements, based on caspase activity, showed that harvesting and dissociation of sponge tissue to initiate a primary cell culture was directly correlated with an increase in apoptotic cells. This indicates that for the development of cell cultures, more attention should be given to harvesting, dissociation, and quality of starting material. Finally, cultivation conditions used were ineffective for proliferation, since after 2 d of cultivating Haliclona oculata cells, most cells shifted towards the apoptotic fraction, indicating that cells were dying. For development of in vitro sponge cell cultures, flow cytometric cell cycle analysis is a useful method to assess the proliferative state of a sponge cell culture and can be used to validate improvements in harvesting and dissociation, to select sponges with good proliferative capacities and to study the influence of culture conditions for stimulating cell growth. PMID:21416188

Schippers, Klaske J; Martens, Dirk E; Pomponi, Shirley A; Wijffels, René H

2011-03-17

13

Life-Cycle Evaluation of Domestic Energy Systems  

NASA Astrophysics Data System (ADS)

Among the growing number of environmental issues, the global warming due to the increasing emission of greenhouse gases, such as carbon dioxide CO2, is the most serious one. In order to reduce CO2 emissions in energy use, it is necessary to reduce primary energy consumption, and to replace energy sources with alternatives that emit less CO2.One option of such ideas is to replace fossil gas for water heating with electricity generated by nuclear power, hydraulic power, and other methods with low CO2 emission. It is also important to use energy efficiently and to reduce waste heat. Co-generation system is one of the applications to be able to use waste heat from a generator as much as possible. The CO2 heat pump water heaters, the polymer electrolyte fuel cells, and the micro gas turbines have high potential for domestic energy systems. In the present study, the life-cycle cost, the life-cycle consumption of primary energy and the life-cycle emission of CO2 of these domestic energy systems are compare. The result shows that the CO2 heat pump water heaters have an ability to reduce CO2 emission by 10%, and the co-generation systems also have another ability to reduce primary energy consumption by 20%.

Bando, Shigeru; Hihara, Eiji

14

Energy Activities for the Primary Classroom. Revised.  

ERIC Educational Resources Information Center

|An energy education program at the primary level should help students to understand the nature and importance of energy, consider different energy sources, learn about energy conservation, prepare for energy related careers, and become energy conscious in other career fields. The activities charts, readings, and experiments provided in this…

Tierney, Blue, Comp.

15

Cell cycle progression by the repression of primary cilia formation in proliferating cells.  

PubMed

In most cell types, primary cilia protrude from the cell surface and act as major hubs for cell signaling, cell differentiation, and cell polarity. With the exception of some cells ciliated during cell proliferation, most cells begin to disassemble their primary cilia at cell cycle re-entry. Although the role of primary cilia disassembly on cell cycle progression is still under debate, recent data have emerged to support the idea that primary cilia exert influence on cell cycle progression. In this review, we emphasize a non-mitotic role of Aurora-A not only in the ciliary resorption at cell cycle re-entry but also in continuous suppression of cilia regeneration during cell proliferation. We also summarize recent new findings indicating that forced induction/suppression of primary cilia can affect cell cycle progression, in particular the transition from G0/G1 to S phase. In addition, we speculate how (de)ciliation affects cell cycle progression. PMID:23475109

Goto, Hidemasa; Inoko, Akihito; Inagaki, Masaki

2013-03-09

16

Phase Relationships Between the CME-Energy Cycle, the Sunspot-Area Cycle and the Flare-Index Cycle  

NASA Astrophysics Data System (ADS)

We study the phase relationships between the coronal-mass-ejection (CME) energy cycle, the sunspot-area cycle, and the flare-index cycle from 1996 to 2010. The results show the following: i) The activity cycle of the flare index significantly leads the activity cycle of the sunspot area. ii) The activity cycle of the CME energy is inferred to be almost in phase with the activity cycle of the sunspot area; the activity cycle of the CME energy at low latitudes slightly leads the activity cycle of the sunspot area; the CME energy at high latitudes is shown to significantly lag behind the sunspot area. iii) The CME energy is shown to significantly lag behind the flare index; the CME energy at low latitudes is shown to slightly lag behind the flare index; the CME energy at high latitudes is shown to significantly lag behind the flare index.

Gao, P. X.; Xie, J. L.; Zhong, J.

2013-10-01

17

Methodology for estimating saving of primary energy with membrane operations in industrial processes  

Microsoft Academic Search

Membrane separation processes can realize significant savings of direct energy (e.g., oil, gas, coal) and indirect energy (intrinsically contained in the materials recovered and\\/or recycled). The methodology of the energy analysis in various industrial cycles is described, and the benefits of these operations, based principally on electrical energy consumption, are evaluated using the definition of “substitution coefficient” (primary energy saved

Raffaele Molinari; Roberto Gagliardi; Enrico Drioli

1995-01-01

18

Comparing Primary Energy Attributed to Renewable Energy with Primary Energy Equivalent to Determine Carbon Abatement in a National Context  

Microsoft Academic Search

The current conventional approach to determining the primary energy associated with non-combustible renewable energy (RE) sources such as wind energy and hydro power is to equate the electricity generated from these sources with the primary energy supply. This paper compares this with an approach that was formerly used by the IEA, in which the primary energy equivalent attributed to renewable

BRIAN P. Ó GALLACHÓIR; FERGAL OLEARY; MORGAN BAZILIAN; MARTIN HOWLEY; EAMON J. MCKEOGH

2006-01-01

19

North American water and energy cycles  

NASA Astrophysics Data System (ADS)

Closure of the water and energy cycles for North America has been improved by combining several new data sets to provide an integrated view from 1979 to 2010. We use new global atmospheric reanalyses, top-of-atmosphere radiation, surface fluxes including evaporation E and precipitation P, streamflow and river discharge, and Gravity Recovery and Climate Experiment estimates of water storage and its tendency. The atmospheric moisture budget provides more reliable estimates and reproducible time series of E-P than separate estimates of E and P. The excess of P over E is greatest in winter largely because of changing evapotranspiration, whereas precipitation is largest in summer. The annual mean loss of energy to space of 33 W m-2 is compensated for nearly equally by transports of dry static energy and latent energy onto land. The annual cycle (amplitude of ~20 W m-2) of implied downward surface flux corresponds to changes in surface and soil temperatures and seasonal snowmelt.

Trenberth, Kevin E.; Fasullo, John T.

2013-01-01

20

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 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.

21

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

22

The effect of social interactions in the primary consumption life cycle of motion pictures  

NASA Astrophysics Data System (ADS)

We develop a 'basic principles' model which accounts for the primary life cycle consumption of films as a social coordination problem in which information transmission is governed by word of mouth. We fit the analytical solution of such a model to aggregated consumption data from the film industry and derive a quantitative estimator of its quality based on the structure of the life cycle.

Hidalgo R, César A.; Castro, Alejandra; Rodriguez-Sickert, Carlos

2006-04-01

23

Gravitational energy, solar radius and solar cycle  

NASA Astrophysics Data System (ADS)

A self-consistent approach is used. From the change (1.2 W/m2) in the solar constant (1367 W/m2) during a solar cycle we deduced a relation between the change in solar radius ?R and the depth d = (1-?)R in the convection zone where the expansion starts. A second relation is obtained by equating the gravitational energy required for the expansion and the decrease in luminosity during half a solar cycle. This yields values for ?R ? 8 km, d ? 0.96R (super-granular region) and for the change in gravitational energy ?E ? 1032J. Similar considerations are made for the Maunder Minimum yielding ?R ? 60 km, d ? 0.94R and ?E ? 1033J. There is some change, say 40 per cent, if we use a quadratic expansion instead of a linear one. Moreover this theory suits a qualitative explanation why the Sun expands during a minimum of the magnetic activity.

Callebaut, Dirk K.; Makarov, Valentine I.; Tlatov, Andrej G.

2002-03-01

24

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

2013-03-01

25

Cell Cycle Modulation in the Response of the Primary Root of Arabidopsis to Salt Stress1  

Microsoft Academic Search

Salt stress inhibits plant growth and development. We investigated the importance of cell cycle regulation in mediating the primary root growth response of Arabidopsis to salt stress. When seedlings were transferred to media with increasing concentrations of NaCl, root growth rate was progressively reduced. At day 3 after transfer of seedlings to growth medium containing 0.5% NaCl the primary roots

Gerrit West; Dirk Inze ´; Gerrit T. S. Beemster

26

Comparing primary energy attributed to renewable energy with primary energy equivalent to determine carbon abatement in a national context.  

PubMed

The current conventional approach to determining the primary energy associated with non-combustible renewable energy (RE) sources such as wind energy and hydro power is to equate the electricity generated from these sources with the primary energy supply. This paper compares this with an approach that was formerly used by the IEA, in which the primary energy equivalent attributed to renewable energy was equated with the fossil fuel energy it displaces. Difficulties with implementing this approach in a meaningful way for international comparisons lead to most international organisations abandoning the primary energy equivalent methodology. It has recently re-emerged in prominence however, as efforts grow to develop baseline procedures for quantifying the greenhouse gas (GHG) emissions avoided by renewable energy within the context of the Kyoto Protocol credit trading mechanisms. This paper discusses the primary energy equivalent approach and in particular the distinctions between displacing fossil fuel energy in existing plant or in new plant. The approach is then extended provide insight into future primary energy displacement by renewable energy and to quantify the amount of CO2 emissions avoided by renewable energy. The usefulness of this approach in quantifying the benefits of renewable energy is also discussed in an energy policy context, with regard to increasing security of energy supply as well as reducing energy-related GHG (and other) emissions. The approach is applied in a national context and Ireland is case study country selected for this research. The choice of Ireland is interesting in two respects. The first relates to the high proportion of electricity only fossil fuel plants in Ireland resulting in a significant variation between primary energy and primary energy equivalent. The second concerns Ireland's poor performance to date in limiting GHG emissions in line with its Kyoto target and points to the need for techniques to quantify the potential contribution of renewable energy in achieving the target set. PMID:16702067

Gallachóir, Brian P O; O'Leary, Fergal; Bazilian, Morgan; Howley, Martin; McKeogh, Eamon J

2006-01-01

27

Low-Cycle Fatigue Tests on Primary Coolant Piping System Components of Fast Reactors.  

National Technical Information Service (NTIS)

The primary objectives of this series of tests are as follows: to assess the validity of the design method provided by Section III of ASME Boiler and Pressure Vessel Code with emphasis placed on low-cycle fatigue design; to make observations of propagatio...

A. Imazu

1980-01-01

28

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

29

Combined cycle energy production: Overview of worldwide utilization and techniques  

NASA Astrophysics Data System (ADS)

The worldwide distribution of combined cycle generators using simple recuperation, supercharged boilers, post combustion, and parallel combustion and complex cycles is summarized. Clean energy, fuel oil, coal, fluidized bed, and gasification based processes are discussed. With clean energy systems, up to 46% efficiency is achieved using a single recuperation - double evaporation cycle. Using gas turbine output to feed a higher power steam turbine is also economically attractive, but no one system is an obvious choice. Around 100 combined generators are now operating.

Roche, M.

1982-06-01

30

Phosphorus cycling in primary and secondary seasonally dry tropical forests in Mexico  

Microsoft Academic Search

– \\u000a \\u000a • Primary forests in the seasonally dry tropical regions of Mexico are disappearing under land-use pressure, creating a mosaic\\u000a of secondary forests of different ages.\\u000a \\u000a \\u000a \\u000a \\u000a – \\u000a \\u000a • In this study we measured the aboveground litterfall phosphorus (P) fluxes, litter-layer and soil P pools to compare the\\u000a P cycles in primary and secondary seasonally dry tropical forests. Our hypothesis was

Patricia Valdespino; Rigoberto Romualdo; Laura Cadenazzi; Julio Campo

2009-01-01

31

Open cycle ocean thermal energy conversion system  

SciTech Connect

An improved open cycle ocean thermal energy conversion system includes 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 flow path 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 flow path 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 there for and impart a desired flow direction to the steam. 10 figs.

Wittig, J.M.

1980-02-19

32

Open cycle ocean thermal energy conversion system  

SciTech Connect

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

33

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

34

Life-cycle energy analysis of buildings: a case study  

Microsoft Academic Search

Energy use is a widely used measure of the environmental impact of buildings. Recent studies have high­ lighted the importance of both the operational and embodied energy attributable to buildings over their life­ time. The method of assessing lifetime building energy is known as life-cycle energy analysis. With Kyoto target obligations necessitating the quantification of greenhouse gas emissions at the

Roger Fay; Graham Treloar; Usha Iyer-Raniga

35

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

36

Hybrid life cycle energy assessment of commercial LED lamps  

Microsoft Academic Search

This work uses hybrid life cycle assessment methods to determine the overall energy use of a commercial LED lamp. Life cycle inventory (LCI) data is built up using industry data for a GaN-based white LED lamp designed to replace conventional incandescent bulbs. Appropriate data are also taken from generic processes in the semiconductor manufacturing sector. By considering the entire life

Matthew J. Eckelman

2009-01-01

37

A Learning Cycle on Exponential Growth and the Energy Crises.  

ERIC Educational Resources Information Center

Describes nature and logistics of a learning cycle approach to teaching exponential growth and the energy crisis. Used with both science and nonscience majors, the cycle uses no algebra, never mentions the terms exponential or logarithmic, and requires a calculator. Instructions for obtaining student and instructor materials are provided.…

Dykstra, D. I., Jr.

1982-01-01

38

Energy life-cycle assessment of soybean biodiesel revisited  

Technology Transfer Automated Retrieval System (TEKTRAN)

A life-cycle assessment (LCA) was conducted to quantify the energy flows associated with biodiesel production. A similar study conducted previously (Sheehan et al., Life Cycle Inventory of Biodiesel and Petroleum Diesel for Use in an Urban Bus, Publication NREL/SR-580-24089, National Renewable Ener...

39

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 ...

40

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

41

Developing Primary School Children's Understanding of Energy Waste  

Microsoft Academic Search

This was an interview study of 34 primary school children's understanding of five aspects of energy waste, and the ways in which these conceptions develop following teaching. The aspects covered were: (i) saving energy by `using less'; (ii) saving energy by using `just enough'; (iii) energy waste through unintended transfers; (iv) energy waste in a household device; and (v) the

Colin Kruger; Mike Summers

2000-01-01

42

Net primary productivity and nutrient cycling across a mesic to wet precipitation gradient in Hawaiian montane forest  

Microsoft Academic Search

Variation in rainfall in humid tropical forests has the potential to alter patterns of primary productivity andnutrient cycling. Net primary productivity (NPP) and nutrient cycling were measured at six sites similar in temperature regime, parent material, ecosystem age, vegetation and topographical relief, while mean annual precipitation (MAP) varied from 2,200 toover 5,000 mm\\/year. Aboveground NPP declined by a factor of

Edward A. G. Schuur; Pamela A. Matson

2001-01-01

43

Energy cycling and hypothetical organisms in Europa's ocean.  

PubMed

While Europa has emerged as a leading candidate for harboring extraterrestrial life, the apparent lack of a source of free energy for sustaining living systems has been argued. In this theoretical analysis, we have quantified the amount of energy that could in principle be obtained from chemical cycling, heat, osmotic gradients, kinetic motion, magnetic fields, and gravity in Europa's subsurface ocean. Using reasonable assumptions based on known organisms on Earth, our calculations suggest that chemical oxidation-reduction cycles in Europa's subsurface ocean could support life. Osmotic and thermal gradients, as well as the kinetic energy of convection currents, also represent plausible alternative sources of energy for living systems at Europa. Organisms thriving on these gradients could interact with each other to form the complex energy cycling necessary for establishing a stable ecosystem. PMID:12449859

Schulze-Makuch, Dirk; Irwin, Louis N

2002-01-01

44

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

45

SWECS Cost of Energy Based on Life Cycle Costing.  

National Technical Information Service (NTIS)

Various Small Wind Energy Conversion Systems (SWECS) being developed under contract to Rocky Flats were subjected to a life cycle costing (LCC) analysis to project the cost of energy available from these systems. SWECS sizes considered were 1-2 kW, 8 kW, ...

W. R. Briggs

1980-01-01

46

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

47

Gas fired combined cycle plant in Singapore: energy use, GWP and cost—a life cycle approach  

Microsoft Academic Search

A life cycle assessment was performed to quantify the non-renewable (fossil) energy use and global warming potential (GWP) in electricity generation from a typical gas fired combined cycle power plant in Singapore. The cost of electricity generation was estimated using a life cycle cost analysis (LCCA) tool. The life cycle assessment (LCA) of a 367.5MW gas fired combined cycle power

R. Kannan; K. C. Leong; Ramli Osman; H. K. Ho; C. P. Tso

2005-01-01

48

Long-term global nuclear energy and fuel cycle strategies  

Microsoft Academic Search

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 E³ (energy\\/economics\\/environmental) model has been adopted and modified with a simplified, but comprehensive and multi-regional, nuclear energy module.

Krakowski

1997-01-01

49

Alternate energy dissipation? Phenolic metabolites and the xanthophyll cycle.  

PubMed

The dynamics of phenolic galloylglucoses (di-, tri-, tetra- and penta-galloylglucose), flavonoids (quercitin and quercitin glycosides) and sideroxylonal were compared with that of xanthophyll cycle-dependent energy dissipation during rapid induction of chilling-dependent photo-inhibition. Pre-dawn xanthophyll cycle engagement of seedlings of Eucalyptus nitens transferred from mild nursery conditions to a low temperature controlled environment increased logarithmically during eight days of treatment. Photochemical efficiency and flavonoids decreased after four days of treatment and non-photochemical quenching after two days of treatment. Galloylglucoses and sideroxylonal decreased linearly during treatment. These results demonstrate that rapid changes in foliar phenolic levels are associated with abrupt changes in the plant environment. It is argued that under these growth-chamber conditions, the xanthophyll cycle facilitated dissipation of excess light energy, lessening the requirement for the dissipation of energy or antioxidant activity through phenolic metabolites. PMID:12756924

Close, Dugald C; Beadle, Chris L

2003-04-01

50

Life cycle optimization model for integrated cogeneration and energy systems applications in buildings  

NASA Astrophysics Data System (ADS)

Energy use in commercial buildings constitutes a major proportion of the energy consumption and anthropogenic emissions in the USA. Cogeneration systems offer an opportunity to meet a building's electrical and thermal demands from a single energy source. To answer the question of what is the most beneficial and cost effective energy source(s) that can be used to meet the energy demands of the building, optimizations techniques have been implemented in some studies to find the optimum energy system based on reducing cost and maximizing revenues. Due to the significant environmental impacts that can result from meeting the energy demands in buildings, building design should incorporate environmental criteria in the decision making criteria. The objective of this research is to develop a framework and model to optimize a building's operation by integrating congregation systems and utility systems in order to meet the electrical, heating, and cooling demand by considering the potential life cycle environmental impact that might result from meeting those demands as well as the economical implications. Two LCA Optimization models have been developed within a framework that uses hourly building energy data, life cycle assessment (LCA), and mixed-integer linear programming (MILP). The objective functions that are used in the formulation of the problems include: (1) Minimizing life cycle primary energy consumption, (2) Minimizing global warming potential, (3) Minimizing tropospheric ozone precursor potential, (4) Minimizing acidification potential, (5) Minimizing NOx, SO 2 and CO2, and (6) Minimizing life cycle costs, considering a study period of ten years and the lifetime of equipment. The two LCA optimization models can be used for: (a) long term planning and operational analysis in buildings by analyzing the hourly energy use of a building during a day and (b) design and quick analysis of building operation based on periodic analysis of energy use of a building in a year. A Pareto-optimal frontier is also derived, which defines the minimum cost required to achieve any level of environmental emission or primary energy usage value or inversely the minimum environmental indicator and primary energy usage value that can be achieved and the cost required to achieve that value.

Osman, Ayat E.

51

Quantitative Model of Cell Cycle Arrest and Cellular Senescence in Primary Human Fibroblasts  

PubMed Central

Primary human fibroblasts in tissue culture undergo a limited number of cell divisions before entering a non-replicative “senescent” state. At early population doublings (PD), fibroblasts are proliferation-competent displaying exponential growth. During further cell passaging, an increasing number of cells become cell cycle arrested and finally senescent. This transition from proliferating to senescent cells is driven by a number of endogenous and exogenous stress factors. Here, we have developed a new quantitative model for the stepwise transition from proliferating human fibroblasts (P) via reversibly cell cycle arrested (C) to irreversibly arrested senescent cells (S). In this model, the transition from P to C and to S is driven by a stress function ? and a cellular stress response function F which describes the time-delayed cellular response to experimentally induced irradiation stress. The application of this model based on senescence marker quantification at the single-cell level allowed to discriminate between the cellular states P, C, and S and delivers the transition rates between the P, C and S states for different human fibroblast cell types. Model-derived quantification unexpectedly revealed significant differences in the stress response of different fibroblast cell lines. Evaluating marker specificity, we found that SA-?-Gal is a good quantitative marker for cellular senescence in WI-38 and BJ cells, however much less so in MRC-5 cells. Furthermore we found that WI-38 cells are more sensitive to stress than BJ and MRC-5 cells. Thus, the explicit separation of stress induction from the cellular stress response, and the differentiation between three cellular states P, C and S allows for the first time to quantitatively assess the response of primary human fibroblasts towards endogenous and exogenous stress during cellular ageing.

Schauble, Sascha; Klement, Karolin; Marthandan, Shiva; Munch, Sandra; Heiland, Ines; Schuster, Stefan; Hemmerich, Peter; Diekmann, Stephan

2012-01-01

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

Photosynthesis â 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 â yet efficient â process for converting solar energy to chemical energy or distributing water throughout a system.

Integrated Teaching And Learning Program

54

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

55

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

56

The Atmospheric Energy and Hydrological Cycles in ECMWF Reanalyses  

NASA Astrophysics Data System (ADS)

Analysing the long term time averaged atmospheric energy and hydrological cycles in atmospheric datasets provides a simple means of measuring the consistency and quality of these datasets. For the energy cycle, we assume that the long term change in storage of the total energy of the atmosphere is small. Energy is absorbed at the TOA at low latitudes, some of which is lost to the surface while the remainder is transported to high latitudes and then, augmented by energy from the surface, is lost to space. The net energy gain to the atmosphere at low latitudes should match the transport from low to high latitudes which, in turn, should match the net energy lost from the atmosphere at high latitudes. For the purposes of this study, we have defined the low latitudes to be between 40N and 40S with the high latitudes encompassing the remainder of the planet, which includes the higher latitudes of both hemispheres. For the hydrological cycle, we assume that the long term change in storage of the total column water vapour of the atmosphere is small. The excess of evaporation compared to precipitation over ocean should match the transport from ocean to land which, in turn, should match the excess of precipitation compared to evaporation over land. Here, we study these cycles as depicted by the ECMWF Interim Reanalysis (ERA-Interim) and ERA-40 for the 20 year period 1989-2008. Although better than in ERA-40, the transport of energy in ERA-Interim does not agree well with the net gain of energy at low latitudes and the net loss of energy at high latitudes unless various corrections are made to the data. These corrections consist of constraining the TOA global energy balance and the surface oceanic energy balance to be zero, constraining the surface energy balance everywhere over land to be zero and mass adjusting the energy transports. The result is an energy transport of 9.5 PW. However, the meridional gradient of the TOA energy balance in ERA-Interim is weaker than in CERES data, so either these transports are at least 10% too weak or the meridional gradient of the energy balance at the surface is too weak. The oceanic E-P and P-E over land are about 15% larger than the 1.1 Tg/s transport of water vapour from ocean to land.

Berrisford, P.; Kallberg, P.; Kobayashi, S.; Dee, D.; Uppala, S.; Simmons, A. J.; Poli, P.; Sato, H.

2012-04-01

57

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.

58

Analysis of cooling cycles with clathrate energy storage  

Microsoft Academic Search

A prototype is presented of a thermal energy storage facility, with an appropriate storage medium, that can be applicable in environmental control of residential and commercial buildings. A simulated heat pump cooling system which utilizes a refrigerant gas hydrate as a storage medium was experimentally and theoretically analyzed. Numerous closed loop cycles using a clathrate in direct contact heat transfer

Gadalla

1988-01-01

59

Open cycle ocean thermal energy conversion system structure  

Microsoft Academic Search

An open cycle, ocean thermal energy conversion system is described, comprising: an axial flow turbine having a substantially vertical rotatable shaft about which at least one axial row of radial blades is disposed, an annular steam inlet structure through which motive steam is supplied to said turbine blades, and a steam outlet structure through which motive steam is exhausted after

Wittig

1980-01-01

60

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

61

Life cycle inventory for electric energy system in Brazil  

Microsoft Academic Search

Goal, Scope and Background  The goal of this paper is to present the modeling of life cycle inventory (LCI) for electric energy production and delivery\\u000a in Brazil for the reference year 2000 by application of ISO 14040. Site specific data along with sector production data have\\u000a been combined to construct an energy production model, which has been applied to emissions estimation.

Leda Coltro; Eloísa E. C. Garcia; Guilherme de C. Queiroz

2003-01-01

62

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

2013-05-28

63

Influence of the El Niño-La Niña cycle on satellite-derived primary production in the California Current  

Microsoft Academic Search

Time series of phytoplankton net primary production (NPP) for the California Current were derived using satellite data and the VGPM primary productivity model for a 5-year period (1997-2001) including the 1997-98 El Niño. NPP had a strong annual periodicity correlated with the El Niño-La Niña cycle. The most obvious effects of the El Niño on NPP were 100-300 km off

Mati Kahru; B. Greg Mitchell

2002-01-01

64

Influence of the El Niño-La Niña cycle on satellite-derived primary production in the California Current  

Microsoft Academic Search

Time series of phytoplankton net primary production (NPP) for the California Current were derived using satellite data and the VGPM primary productivity model for a 5-year period (1997–2001) including the 1997–98 El Niño. NPP had a strong annual periodicity correlated with the El Niño-La Niña cycle. The most obvious effects of the El Niño on NPP were 100-300 km off

Mati Kahru; B. Greg Mitchell

2002-01-01

65

Carbon dioxide release from ocean thermal energy conversion (OTEC) cycles  

SciTech Connect

This paper presents the results of recent measurements of CO{sub 2} release from an open-cycle ocean thermal energy conversion (OTEC) experiment. Based on these data, the rate of short-term CO{sub 2} release from future open-cycle OTEC plants is projected to be 15 to 25 times smaller than that from fossil-fueled electric power plants. OTEC system that incorporate subsurface mixed discharge are expected to result in no long-term release. OTEC plants can significantly reduce CO{sub 2} emissions when substituted for fossil-fueled power generation. 12 refs., 4 figs., 3 tabs.

Green, H.J. (Solar Energy Research Inst., Golden, CO (USA)); Guenther, P.R. (Scripps Institution of Oceanography, La Jolla, CA (USA))

1990-09-01

66

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

67

Energy and Materials Flows in the Production of Primary Aluminum.  

National Technical Information Service (NTIS)

The primary aluminum industry is one of the top five industrial energy users in the United States consuming about one quad annually. In 1980, for each ton of aluminum produced, an average smelting operation used about 157 million Btu of direct energy and ...

S. Y. Shen

1981-01-01

68

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

69

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...

70

The Development Strategies of Energy Service Companies in China Based on the Industry Life Cycle  

Microsoft Academic Search

As a vehicle for promoting energy efficiency, energy service companies play an important role in achieving China's goal in energy conservation. Based on the industry life cycle theory, the paper studies the energy service industry's life cycle in China. And according to the relationship between the industry life cycle and the enterprise development strategies, the paper draws the conclusion that

Xiaoping Tian

2011-01-01

71

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

72

Thermal energy storage in a confined aquifer: Second cycle  

Microsoft Academic Search

During the first 6-month injection-storage-recovery cycle of the Auburn University Aquifer Thermal Energy Storage Project, water pumped from an upper supply aquifer was heated to an average temperature of 55°C with an oil-fired boiler and then injected into a lower storage aquifer. Injection and recovery temperatures, flow rates, and temperatures at six depths in 10 observation wells and hydraulic heads

F. J. Molz; A. D. Parr; P. F. Andersen

1981-01-01

73

Energy and latency control in low duty cycle MAC protocols  

Microsoft Academic Search

Recently, several MAC protocols, such as S-MAC and T-MAC, have exploited scheduled sleep\\/wakeup cycles to conserve energy in sensor networks. Until now, most protocols have assumed all nodes in the network were configured to follow the same schedule, or have assumed border nodes would follow multiple schedules, but those cases have not been evaluated. The paper develops two new algorithms

Yuan Li; Wei Ye; John Heidemann

2005-01-01

74

Energy balance during two days of continuous stationary cycling  

Microsoft Academic Search

This study examined the capabilities of an ultraendurance athlete to self-regulate their diet during an attempt on the record for the longest period of stationary cycling. The attempt required the athlete to complete at least 20 km\\/hr, with a 15 minute break allowed every eight hours. Laboratory tests determined a heart rate-oxygen consumption regression equation enabling calculation of energy expenditure

Ian B Stewart; Kelly L Stewart

2007-01-01

75

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

2010-04-08

76

Cinematographic observations of growth cycles of Chlamydia trachomatis in primary cultures of human amniotic cells.  

PubMed Central

Time-lapse cinematography was used to study the growth cycle of Chlamydia trachomatis in primary cell cultures of human amnion. Twelve preterm and twelve term placentas were obtained within 8 h of delivery, and epithelial cells were dissociated from the amniotic membranes by trypsinization and grown in Rose chambers. The epithelial nature of the cultured cells was documented by morphology and by immunofluorescence staining for cytoskeletal proteins, which matched the staining of intact amnion. With regular feedings, uninfected cultures remained healthy for up to 30 days. Confluent cultures (7 to 10 days) were infected with a genital strain (E/UW-5/CX) of C. trachomatis at 10(5) infectious units per chamber. Infections were done in culture medium without cycloheximide, which is often used to induce susceptibility of the cells. Between 66 and 90% of the cells were infected. Intracytoplasmic inclusions were visible by 18 h post infection (p.i.) and grew larger as the organisms inside multiplied. By 72 h p.i., the inclusions occupied the entire cytoplasm of the host cells. Further growth of the inclusions overdistended and ruptured the host cells on days 3 to 7. Cells not infected by the original inoculum became infected on day 5 or 6 p.i. by the chlamydial particles released from the ruptured cells. No amniotic cell was ever observed to survive the infection. The data presented support the hypothesis that amniotic epithelium is susceptible to infection and damage by C. trachomatis. This culture system provided detailed and dynamic observations of chlamydial infection under conditions more nearly physiologic than previously reported. Images

Neeper, I D; Patton, D L; Kuo, C C

1990-01-01

77

The NASA Energy and Water Cycle Climatology (NEWCC) Integration Project  

NASA Astrophysics Data System (ADS)

To date, a truly self-consistent, quantitative description of the Earth's global water and energy cycles, based on the highest quality, independently-observed pieces of information that decipher each of the key storage terms, fluxes, and pathways has been elusive. Such a data compilation of adequate climate quality is of vital interest and an ultimate scientific need of the global observation, modeling, and prediction community. To meet this need, we present results from the first phase of a NASA Energy and Water Cycle Climatology (NEWCC) Integration Project, a collaborative effort whose aim is to construct a defensible, self-consistent, long-term climatology of the global energy and water cycles. Our working hypothesis is that an observationally-based estimate of water and energy fluxes and storages, derived from focused and independently observed components of these cycles, can be balanced and provide useful characterizations and evaluation data for climate prediction and predictability studies. The NEWCC team members are actively involved in key facets of this observational arena, and thus for the first phase of NEWCC, we bring together state-of-the-art, (predominantly) satellite-based observations that include: precipitation, ocean and land evaporation, runoff, atmospheric water storage, ocean and land storage changes, atmospheric transport, radiation, latent and sensible heat fluxes, and subsequently hope to include explicit snow/ice information, such as snow water equivalent and ice mass changes. Our current efforts focus on the period spanning the years 2003 to 2005, for which the most recent and highest-quality satellite-based information is available for all the aforementioned quantities. We present an assessment of the ability of these observational datasets to satisfy the water and energy budgets and the degree to which they show consistency in their mean annual cycles as well as geospatial variability. In doing so, we will highlight, where possible, the most egregious areas of imbalance and inconsistency while also providing a quantification of measurement errors to identify which algorithms and/or measurements hold the most promise for improvement.

Schlosser, C. A.; Lin, B.; NEWCC Team

2008-05-01

78

Solar power satellite life-cycle energy recovery consideration  

SciTech Connect

The construction, in-orbit installation and maintenance of a solar power satellite (SPS) will demand large amounts of energy. As a minimum requirement for an energy effective power satellite it is asked that this amount of energy be recovered. The energy effectiveness in this sense resulting in a positive net energy balance is a prerequisite for cost-effective power satellite. This paper concentrates on life-cycle energy recovery instead on monetary aspects. The trade-offs between various power generation systems (different types of solar cells, solar dynamic), various construction and installation strategies (using terrestrial or extra-terrestrial resources) and the expected/required lifetime of the SPS are reviewed. The presented work is based on a 2-year study performed at the Technical University of Munich. The study showed that the main energy which is needed to make a solar power satellite a reality is required for the production of the solar power components (up to 65%), especially for the solar cell production. Whereas transport into orbit accounts in the order of 20% and the receiving station on earth (rectenna) requires about 15% of the total energy investment. The energetic amortization time, i.e. the time the SPS has to be operational to give back the amount of energy which was needed for its production installation and operation, is about two years.

Weingartner, S.; Blumenberg, J. [Deutsche Aerospace AG, Munich (Germany)]|[Technical Univ. of Munich, Munich (Germany)

1994-12-31

79

Solar energy demand (SED) of commodity life cycles.  

PubMed

The solar energy demand (SED) of the extraction of 232 atmospheric, biotic, fossil, land, metal, mineral, nuclear, and water resources was quantified and compared with other energy- and exergy-based indicators. SED represents the direct and indirect solar energy required by a product or service during its life cycle. SED scores were calculated for 3865 processes, as implemented in the Ecoinvent database, version 2.1. The results showed that nonrenewable resources, and in particular minerals, formed the dominant contribution to SED. This large share is due to the indirect solar energy required to produce these resource inputs. Compared with other energy- and exergy-based indicators, SED assigns higher impact factors to minerals and metals and smaller impact factors to fossil energetic resources, land use, and nuclear energy. The highest differences were observed for biobased and renewable energy generation processes, whose relative contribution of renewable resources such as water, biomass, and land occupation was much lower in SED than in energy- and exergy-based indicators. PMID:21545085

Rugani, Benedetto; Huijbregts, Mark A J; Mutel, Christopher; Bastianoni, Simone; Hellweg, Stefanie

2011-05-05

80

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

81

Thermodynamic Optimisation of the Otto \\/ Stirling Combined Cycle  

Microsoft Academic Search

Combined cycle systems are an established method for increasing primary energy efficiency of power generation systems. Some ongoing research is concerned with investigating the novel combined cycle system involving the Otto and Stirling thermodynamic cycles. The Otto cycle is to act as the topping cycle, with the Stirling cycle acting to recover heat from the exhaust for the purpose of

Barry Cullen; Michel Feidt; Jim McGovern; Stoian Petrescu

2010-01-01

82

IRF-1 Is an Essential Mediator in IFN-?-Induced Cell Cycle Arrest and Apoptosis of Primary Cultured Hepatocytes  

Microsoft Academic Search

IFN-? induces cell cycle arrest and p53-independent apoptosis in primary cultured hepatocytes. However, it is not yet understood what molecules regulate the mechanism. We report here that interferon regulatory factor 1 (IRF-1) is an essential molecule in these phenomena. Hepatocytes from IRF-1-deficient mice were completely resistant to IFN-? in apoptosis indicated by three different hallmarks such as LDH release, DNA

Arihiro Kano; Takahiro Haruyama; Toshihiro Akaike; Yoshifumi Watanabe

1999-01-01

83

Nuclear Primary Energy Carriers. Pt. 2. Energy from Nuclear Fusion.  

National Technical Information Service (NTIS)

A very brief presentation of the elementary fusion reactions, the energies delivered by them and the most basic energy balances leading to Lawson-type diagrams are given. The report estimates reserves and cost of lithium and deuterium, gives estimates of ...

1978-01-01

84

CTLA-4 regulates cell cycle progression during a primary immune response.  

PubMed

Engagement of CTLA-4 is critical for inhibiting T cell immune responses. Recent studies have shown that CTLA-4 plays a key role in regulating peripheral T cell tolerance. It has been suggested that one mechanism by which CTLA-4 performs this function is by regulating cell cycle progression. Here, we investigate in depth the role of CTLA-4 in regulating cell cycle progression in naive T cells by comparing the immune responses in the absence or presence of CTLA-4. In the absence of CLTA-4, T cells exhibit marked increases in T cell proliferation, IL-2 mRNA and protein secretion, and cells cycling in the S and G2-M phase. Analyses of cyclins, cyclin-dependent kinases, and cell cycle inhibitors involved in the transition from the G1 to S phase reveal that cell cycle progression is prolonged in the absence of CTLA-4. This is due to the early exit from the G1 phase, entry into the S phase, and prolonged S phase period. Re-expression of the cell cycle inhibitor p27(kip1) is delayed in the absence of CTLA-4. These studies demonstrate that the B7 : CTLA-4 pathway exerts its major effects on T cell immune responses via regulation of the cell cycle. PMID:11807776

Greenwald, Rebecca J; Oosterwegel, Mariette A; van der Woude, Diane; Kubal, Anup; Mandelbrot, Didier A; Boussiotis, Vassiliki A; Sharpe, Arlene H

2002-02-01

85

Influence of Neutron Energy Spectrum on Primary Damage Formation  

SciTech Connect

Displacement cascade formation in iron has been investigated by the method of molecular dynamics (MD) for cascade energies up to 40 keV. The results of these simulations have been used to obtain effective, energy-dependent cross sections for two measures of primary damage production: (1) the number of surviving point defects expressed as a fraction of the those predicted by the standard secondary displacement model by Norgett, Robinson, and Torrens (NRT),and (2) the fraction of the surviving interstitials contained in clusters that formed during the cascade event. The primary knockon atom spectra for iron obtained from the SPECTER code have been used to weight these MD-based damage production cross sections in order to obtain spectrally-averaged values for several locations in commercial fission reactors, materials test reactors, a DT fusion reactor first wall, and a pulsed spallation neutron source. An evaluation of these results indicates that neutron energy spectrum differences between the various environments do not lead to significant differences between the average primary damage formation parameters. This conclusion implies that the displacement damage component of radiation damage produced in a high energy spallation neutron source should be well simulated by irradiation in a fission reactor neutron spectrum, and that differences in nuclear transmutation production may be a greater source of uncertainty in the prediction of material performance in the planned National Spallation Neutron Source.

Stoller, R.E. [Oak Ridge National Lab., TN (United States) Metals and Ceramics Div.], Greenwood, L.R. [Pacific Northwest National Lab., Richland, WA (United States) Materials and Chemistry Div.

1997-12-31

86

Life cycle assessment of primary magnesium production using the Pidgeon process in China  

Microsoft Academic Search

Background, aims, and scope  China has been the largest primary magnesium producer in the world since year 2000 and is an important part of the global\\u000a magnesium supply chain. Almost all of the primary magnesium in China is produced using the Pidgeon process invented in the\\u000a 1940s in Canada. The environmental problems of the primary magnesium production with the Pidgeon process

Feng Gao; Zuoren Nie; Zhihong Wang; Xianzheng Gong; Tieyong Zuo

2009-01-01

87

Life cycle cost and energy analysis of a Net Zero Energy House with solar combisystem  

Microsoft Academic Search

The Net Zero Energy House (NZEH) presented in this paper is an energy efficient house that uses available solar technologies to generate at least as much primary energy as the house uses over the course of the year. The computer simulation results show that it is technically feasible to reach the goal of NZEH in the cold climate of Montreal.

Mitchell Leckner; Radu Zmeureanu

2011-01-01

88

Energy use in the life cycle of conventional and low-energy buildings: A review article  

Microsoft Academic Search

A literature survey on buildings’ life cycle energy use was performed, resulting in a total of 60 cases from nine countries. The cases included both residential and non-residential units. Despite climate and other background differences, the study revealed a linear relation between operating and total energy valid through all the cases. Case studies on buildings built according to different design

I. Sartori; A. G. Hestnes

2007-01-01

89

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

90

Primary defect production by high energy displacement cascades in molybdenum  

NASA Astrophysics Data System (ADS)

We report molecular dynamics simulations of primary damage in molybdenum produced by high energy displacement cascades on the femto- to pico-second and Angstrom to nanometer scales. Clustering directly occurred for both interstitials and vacancies in the 1-50 keV cascade energy range explored. Point defect survival efficiency and partitioning probabilities into different sized clusters were quantified. The results will provide an important reference for kinetic models to describe the microstructural evolution in Mo under ion or neutron irradiations over much longer time and length scales.

Selby, Aaron P.; Xu, Donghua; Juslin, Niklas; Capps, Nathan A.; Wirth, Brian D.

2013-06-01

91

Energy management in a closed-cycle high-energy laser  

NASA Astrophysics Data System (ADS)

PULSAR is a subscale closed-cycle, high-energy, pulsed, Electric Discharge Laser (EDL) fabricated at the Air Force Weapons Lab (AFWL) for the purpose of studying technology issues related to closed-cycle laser operation. A computer code has been written for PULSAR that describes the thermodynamic and fluid transient performance of the gas loop. A description of the PULSAR loop is presented, together with steady-state and transient performance predictions. Experimental data is compared to predicted performance parameters, and a description of the code is presented to illustrate generalized techniques which can be applied to other closed-cycle systems.

Kunstadt, E.; White, E.

1980-07-01

92

Nuclear energy as a primary energy source for hydrogen production  

Microsoft Academic Search

Work currently under way in West Germany on the development of nuclear reactors to supply high-temperature (300-1000 C) process heat for coal liquefaction and gasification and the production of hydrogen to meet future energy demands is reviewed. The AVR reactor in Juelich, which has been supplying heat at a maximum temperature of 950 C since 1975, is described, with consideration

R. Schulten

1979-01-01

93

Life-cycle assessments: Linking energy, economics, and the environment. Paper No. 571.  

National Technical Information Service (NTIS)

The Pacific Northwest Laboratory has been involved in a number of life-cycle assessment (LCA) projects that assess the complete lifetime energy, economic, and environmental impacts of alternative technology options. Life-cycle assessments offer one-stop s...

S. A. Shankle

1994-01-01

94

Do lightweight materials really save energy. [Automobile, life cycle energy use (LCEU)  

SciTech Connect

The concept of life cycle energy use (LCEU) has been developed because of serious concerns over energy crises during recent years. This approach to energy conservation is based on the premise that the product consuming least energy in terms of manufacture and end use is preferred. Suppliers of aluminum and plastics are challenging the automobile industry on LCEU. One of their major tenets is that the high energy consumption needed for aluminum or plastic components is justified by the petroleum fuel savings of a lighter car during its lifetime. Four scenarios are considered representative of the life cycle energy position of lightweight materials substitution: high strength steel replacing conventional steel, aluminum replacing steel body sheet, plastic replacing steel body sheet, and aluminum castings replacing iron ones.

Not Available

1982-03-01

95

Estimate of the energy spread in a booster cycle via the bunch length measurement  

SciTech Connect

It is important for us to obtain the information of energy spread vs. time in a Booster cycle via the same beam event, for the purpose of minimizing the error caused by the cycle-to-cycle fluctuation. The bunch length (BL) can be extracted from the resistive wall signal (RWS) at different times of a Booster cycle, and from which the energy spread can be estimated.

Yang, Xi; /Fermilab

2004-11-01

96

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

97

Life-Cycle Costing Manual for the Federal Energy Management Program. 1995 Edition.  

National Technical Information Service (NTIS)

Handbook 135 is a guide to understanding the life-cycle cost (LCC) methodology and criteria established by the Federal Energy Management Program (FEMP) for the economic evaluation of energy and water conservation projects and renewable energy projects in ...

S. K. Fuller S. R. Petersen

1996-01-01

98

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

99

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

100

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

101

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

102

Primary Structure and Phylogeny of the Calvin Cycle Enzymes Transketolase and Fructosebisphosphate Aldolase of Xanthobacter flavus  

Microsoft Academic Search

Xanthobacter flavus, a gram-negative facultatively autotrophic bacterium, employs the Calvin cycle for the fixation of carbon dioxide. Cells grown under autotrophic growth conditions possess an Fe2+-dependent fructosebisphosphate (FBP) aldolase (class II) in addition to a class I FBP aldolase. By nucleotide sequencing and heterologous expression in Escherichia coli, genes encoding transketolase (EC 2.2.1.1.; CbbT) and class II FBP aldolase (EC

S. C. Baker; R. J. Raggers; P. Terpstra; E. C. Woudstra; L. Dijkhuizen; W. G. Meijer

1996-01-01

103

High primary productivity and nitrogen cycling after the Paleoproterozoic phosphogenic event in the Aravalli Supergroup, India  

Microsoft Academic Search

The causes of atmospheric oxygenation in the Paleoproterozoic are multifaceted yet poorly understood. An increase in the level of primary productivity however may have been an important factor in producing large amounts of oxygen in the atmosphere. A likely environmental consequence of atmospheric oxygenation is an increased abundance of seawater nitrate, which would have resulted in a fundamental change from

Dominic Papineau; Ritesh Purohit; Tatiana Goldberg; Daohui Pi; Graham A. Shields; Harsh Bhu; Andrew Steele; Marilyn L. Fogel

2009-01-01

104

Open cycle ocean thermal energy conversion system structure  

SciTech Connect

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

105

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

106

Energy system feasibility study of an Otto cycle\\/Stirling cycle hybrid automotive engine  

Microsoft Academic Search

The aim of this study was to investigate the feasibility of utilising a Stirling cycle engine as an exhaust gas waste heat recovery device for an Otto cycle internal combustion engine (ICE) in the context of an automotive power plant. The hybrid arrangement would produce increased brake power output for a given fuel consumption rate when compared to an ICE

Barry Cullen; Jim McGovern

2010-01-01

107

Energy intake and energy expenditure during the menstrual cycle in short-term smoking cessation  

Microsoft Academic Search

The effect of short-term smoking abstinence on energy intake and expenditure parameters was investigated for women in different phases of the menstrual cycle (follicular or late luteal) in a rigorous inpatient laboratory setting. Twenty-one participants were randomized to a continued smoking (n = 5) or a smoking abstinence (n = 16) group and admitted for 2 7-day inpatient periods during

Sharon S Allen; Dorothy Hatsukami; Darcy Christianson; Scott Brown

2000-01-01

108

An application-specific duty cycle adjustment MAC protocol for energy conserving over wireless sensor networks  

Microsoft Academic Search

Wireless sensors are battery-powered sensing and computing devices. Comparing with wired sensors, wireless sensors have limited battery life that restricts the communication rage and working time of sensor nodes. Duty cycle adjustment affects the energy consumption and data transmission of wireless sensors. The long duty cycle makes the sensors can have more time to transmit data, and low duty cycle

Tz-heng Hsu; Jyun-sian Wu

2008-01-01

109

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

110

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

111

Insolation cycles as a major control of equatorial indian ocean primary production  

PubMed

Analysis of a continuous sedimentary record taken in the Maldives indicates that strong primary production fluctuations (70 to 390 grams of carbon per square meter per year) have occurred in the equatorial Indian Ocean during the past 910,000 years. The record of primary production is coherent and in phase with the February equatorial insolation, whereas it shows diverse phase behavior with delta18O, depending on the orbital frequency (eccentricity, obliquity, or precession) examined. These observations imply a direct control of productivity in the equatorial oceanic system by insolation. In the equatorial Indian Ocean, productivity is driven by the wind intensity of westerlies, which is related to the Southern Oscillation; therefore, it is suggested that a precession forcing on the Southern Oscillation is responsible for the observed paleoproductivity dynamics. PMID:9367955

Beaufort; Lancelot; Camberlin; Cayre; Vincent; Bassinot; Labeyrie

1997-11-21

112

Energy life cycle assessment of rice straw bio-energy derived from potential gasification technologies.  

PubMed

To be a viable alternative, a biofuel should provide a net energy gain and be capable of being produced in large quantities without reducing food supplies. Amounts of agricultural waste are produced and require treatment, with rice straw contributing the greatest source of such potential bio-fuel in Taiwan. Through life-cycle accounting, several energy indicators and four potential gasification technologies (PGT) were evaluated. The input energy steps for the energy life cycle assessment (ELCA) include collection, generator, torrefaction, crushing, briquetting, transportation, energy production, condensation, air pollution control and distribution of biofuels to the point of end use. Every PGT has a positive energy benefit. The input of energy required for the transportation and pre-treatment are major steps in the ELCA. On-site briquetting of refused-derived fuel (RDF) provides an alternative means of reducing transportation energy requirements. Bio-energy sources, such as waste rice straw, provide an ideal material for the bio-fuel plant. PMID:21507625

Shie, Je-Lueng; Chang, Ching-Yuan; Chen, Ci-Syuan; Shaw, Dai-Gee; Chen, Yi-Hung; Kuan, Wen-Hui; Ma, Hsiao-Kan

2011-04-02

113

New global observations of the terrestrial carbon cycle from GOSAT: Patterns of plant fluorescence with gross primary productivity  

NASA Astrophysics Data System (ADS)

Our ability to close the Earth's carbon budget and predict feedbacks in a warming climate depends critically on knowing where, when and how carbon dioxide is exchanged between the land and atmosphere. Terrestrial gross primary production (GPP) constitutes the largest flux component in the global carbon budget, however significant uncertainties remain in GPP estimates and its seasonality. Empirically, we show that global spaceborne observations of solar induced chlorophyll fluorescence - occurring during photosynthesis - exhibit a strong linear correlation with GPP. We found that the fluorescence emission even without any additional climatic or model information has the same or better predictive skill in estimating GPP as those derived from traditional remotely-sensed vegetation indices using ancillary data and model assumptions. In boreal summer the generally strong linear correlation between fluorescence and GPP models weakens, attributable to discrepancies in savannas/croplands (18-48% higher fluorescence-based GPP derived by simple linear scaling), and high-latitude needleleaf forests (28-32% lower fluorescence). Our results demonstrate that retrievals of chlorophyll fluorescence provide direct global observational constraints for GPP and open an entirely new viewpoint on the global carbon cycle. We anticipate that global fluorescence data in combination with consolidated plant physiological fluorescence models will be a step-change in carbon cycle research and enable an unprecedented robustness in the understanding of the current and future carbon cycle.

Frankenberg, Christian; Fisher, Joshua B.; Worden, John; Badgley, Grayson; Saatchi, Sassan S.; Lee, Jung-Eun; Toon, Geoffrey C.; Butz, André; Jung, Martin; Kuze, Akihiko; Yokota, Tatsuya

2011-09-01

114

Disturbance of sandflats by thin terrigenous sediment deposits: consequences for primary production and nutrient cycling.  

PubMed

The contributions of biodiversity to ecosystem functioning are increasingly recognized by ecologists, with biodiversity loss considered a significant threat to the maintenance of life-supporting ecosystem goods and services. Although ecologists have increased the amount of realism in biodiversity-ecosystem functioning (BEF) experiments, effects on functioning are rarely investigated in the field in conjunction with disturbances that affect biodiversity. Here, effects on functioning were investigated in situ following experimental disturbance of a realistic type and magnitude. Experimental deposits of terrigenous sediment (5 mm thickness) were applied at three intertidal sites in Whangapoua Harbour (Coromandel Peninsula, New Zealand), where soil erosion associated with logging is a serious problem. Experimental disturbance by terrigenous sediment impacted macrofaunal abundance and community composition (suspension and deposit feeders), and there were coincident shifts in ecosystem functioning at all three sites. Relative to controls, sediment-treated plots had higher rates of ammonium efflux (despite 50% fewer macrofaunal individuals) and lower rates of gross primary production and photosynthetic efficiency (despite similar sediment chlorophyll a concentrations). Judging from nutrient ratios in sediment pore water, microphyte primary producers living on the sediment surface in control plots were likely nitrogen limited (the normal situation for marine waters), whereas microphytes in sediment-treated plots were likely phosphate limited. Gross primary production and photosynthetic efficiency were significantly and positively correlated with ammonium uptake in control plots (r2 = 0.463 and 0.856, respectively) but not in treated plots (P > 0.05, r2 < 0.3). We suggest that the higher content of charged particles (clay) in the experimental deposits bound up phosphate, limiting its bio-availability, and shifted functional relationships between sandflat macrofauna and sediment primary productivity. PMID:21563573

Rodil, Iván F; Lohrer, Andrew M; Chiaroni, Luca D; Hewitt, Judi E; Thrush, Simon F

2011-03-01

115

Life cycle management of energy-consuming products in companies using IO-LCA  

Microsoft Academic Search

Background, aim, and scope  Today, the effective integration of life cycle thinking into existing business routines is argued to be the most critical\\u000a step for more sustainable business models. The study tests the suitability of an input–output life cycle assessment (IO-LCA)\\u000a approach in screening life cycle impacts of energy-using products in companies. It estimates the life cycle impacts of three\\u000a products

Seppo Junnila

2008-01-01

116

Waste recycling primary source of energy in deep ocean  

NASA Astrophysics Data System (ADS)

In the dark reaches of the deep ocean, far from the photosynthesizing plants and plankton that fuel life in the surface waters, ecosystems survive on chemical energy. Decades of research on the life that clusters around deep-sea hydrothermal vents has hinted at the importance of light-free food webs, but a recent analysis by Middelburg suggests that another system—waste recycling—could be the dominant pillar of life on the abyssal plains. The realization was a result of the author's attempt to calculate the importance of chemoautotrophy to the carbon cycles of different ocean regions. levels increase rates of denitrification and methanogenesis, thus increasing gas production rates. The authors also found that methane bubbles surpass diffused nitrous oxide in terms of global warming potential, which they suggest could warrant a rethinking of the importance of streams and rivers to global warming. (Journal of Geophysical Research-Biogeosciences, doi:10.1029/2011JG001656, 2011)

Schultz, Colin

2012-02-01

117

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

118

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

Code of Federal Regulations, 2010 CFR

...concerning natural gas as the primary energy source for qualifying small power production...concerning natural gas as the primary energy source for qualifying small power production...considered as waste as the primary energy source pursuant to §...

2010-04-01

119

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

Code of Federal Regulations, 2010 CFR

...concerning natural gas as the primary energy source for qualifying small power production...concerning natural gas as the primary energy source for qualifying small power production...considered as waste as the primary energy source pursuant to §...

2009-04-01

120

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

Code of Federal Regulations, 2013 CFR

...concerning natural gas as the primary energy source for qualifying small power production...concerning natural gas as the primary energy source for qualifying small power production...considered as waste as the primary energy source pursuant to §...

2013-04-01

121

Energy Basis of Disasters and the Cycles of Order and Disorder.  

National Technical Information Service (NTIS)

A quantitative theory of cycles order and disorder was applied to the earth and evaluated to form an energy basis for the global cycles, surges, and disasters. Energy circuit language was used to diagram the world system and show a common pattern in the o...

J. F. Alexander

1978-01-01

122

Life Cycle Assessment of electricity production from poplar energy crops compared with conventional fossil fuels  

Microsoft Academic Search

The environmental impact of electric power production through an Integrated Gasification Combined Cycle (IGCC) fired by dedicated energy crops (poplar Short Rotation Forestry (SRF)) is analysed by a Life Cycle Assessment approach. The results are compared with the alternative option of producing power by conventional fossil fueled power plants. The energy and raw materials consumption and polluting emissions data both

Angelantonio Rafaschieri; Mario Rapaccini; Giampaolo Manfrida

1999-01-01

123

Sustainability Indicators for Open-Cycle Thorium-Fuelled Nuclear Energy  

Microsoft Academic Search

The potential for countries which currently have a nominal nuclear energy infrastructure to adopt thorium-uranium-fuelled nuclear energy systems, using a once-through “open” nuclear fuel cycle, has been presented by the International Atomic Energy Agency. This paper highlights Generation III and III+ nuclear energy technologies that could potentially adopt an open thorium-uranium fuel cycle and qualitatively highlights the main differences between

S. F. Ashley; R. A. Fenner; W. J. Nuttall

2012-01-01

124

Raw materials cycles and energy use - Anthropogenic loading and the limits to carrying capacity  

NASA Astrophysics Data System (ADS)

The interrelation of raw materials cycles with energy use and environmental degradation is explored. The earth's energy balance, the nitrogen and carbon cycles, the various pollutants such as sulfur dioxide, oxides of nitrogen, and particulates and their sources are discussed. Techniques of industrial production of copper that will save energy, conserve raw materials, and reduce pollution, yet retain current levels or even increase output, are described. The effect that increased use of solar energy can have on such trends is quantitatively investigated.

Sinn, H.

125

Nitrogen cycling in an integrated biomass for energy system  

SciTech Connect

A series of experiments was conducted to evaluate N cycling in three components of an integrated biomass for energy system, i.e. water hyacinth production, anaerobic digestion in hyacinth biomass, and recycling of digester effluent and sludge. Plants assimilated 50 to 90% of added N in hyacinth production systems. Up to 28% of the total plant N was contained in hyacinth detritus. Nitrogen loading as plant detritus into hyacinth ponds was 92 to 148 kg N ha/sup -1/ yr/sup -1/. Net mineralization of plant organic /sup 15/N during anaerobic digestion was 35 and 70% for water hyacinth plants with low and high N content, respectively. Approximately 20% of the /sup 15/N was recovered in the digested sludge while the remaining /sup 15/N was recovered in the effluent. Water hyacinth growth in digester effluents was affected by electrical conductivity and /sup 15/NH/sub 4//sup +/-N concentration. Addition of water hyacinth biomass to soil resulted in decomposition of 39 to 50% of added C for fresh plant biomass and 19 to 23% of added C for digested biomass sludge. Only 8% of added /sup 15/N in digested sludges was mineralized to /sup 15/NO/sub 3//sup -/-N despite differences in initial N content. In contrast, 3 and 33% of added /sup 15/N in fresh biomass with low and high N content, respectively, was recovered as /sup 15/NO/sub 3//sup -/-N. Total /sup 15/N recovery after anaerobic digestion ranged from 70 to 100% of the initial plant biomass /sup 15/N. Total N recovery by sludge and effluent recycling in the integrated biomass for energy system was 48 to 60% of the initial plant biomass /sup 15/N.

Moorhead, K.K.

1986-01-01

126

Energy intake and energy expenditure during the menstrual cycle in short-term smoking cessation.  

PubMed

The effect of short-term smoking abstinence on energy intake and expenditure parameters was investigated for women in different phases of the menstrual cycle (follicular or late luteal) in a rigorous inpatient laboratory setting. Twenty-one participants were randomized to a continued smoking (n = 5) or a smoking abstinence (n = 16) group and admitted for 2 7-day inpatient periods during alternate cycle phases. The smoking abstinence group experienced 2 days of baseline smoking and 5 days of smoking abstinence. Measurements included caloric intake (kcal/24 hours), energy expenditure (by indirect calorimetry), and weight. Results of within-subject analyses indicated no smoking abstinence effect on mean daily total kilocalorie intake, sweet kilocalorie intake, or resting metabolic rate. However, a significant cycle phase effect was observed, with increased kilocalorie intake and expenditure-as well as minor weight gain-occurring during the late luteal phase when premenstrual symptoms are highest. In light of this phase effect, women smokers might benefit by attempting to quit smoking during the follicular phase of their cycle. PMID:10972447

Allen, S S; Hatsukami, D; Christianson, D; Brown, S

127

Impact of Nuclear Energy Futures on Advanced Fuel Cycle Options  

SciTech Connect

The Nuclear Waste Policy Act requires the Secretary of Energy to inform Congress before 2010 on the need for a second geologic repository for spent nuclear fuel. By that time, the spent fuel discharged from current commercial reactors will exceed the statutory limit of the first repository (63,000 MTiHM commercial, 7,000 MT non-commercial). There are several approaches to eliminate the need for another repository in this century. This paper presents a high-level analysis of these spent fuel management options in the context of a full range of possible nuclear energy futures. The analysis indicates the best option to implement varies depending on the nuclear energy future selected. The first step in understanding the need for different spent fuel management approaches is to understand the size of potential spent fuel inventories. A full range of potential futures for domestic commercial nuclear energy is considered. These energy futures are as follows: 1. Existing License Completion - Based on existing spent fuel inventories plus extrapolation of future plant-by-plant discharges until the end of each operating license, including known license extensions. 2. Extended License Completion - Based on existing spent fuel inventories plus a plant-by-plant extrapolation of future discharges assuming on all operating plants having one 20-year extension. 3. Continuing Level Energy Generation - Based on extension of the current ~100 GWe installed commercial base and average spent fuel discharge of 2100 MT/yr through the year 2100. 4. Continuing Market Share Generation – Based on a 1.8% compounded growth of the electricity market through the year 2100, matched by growing nuclear capacity and associated spent fuel discharge. 5. Growing Market Share Generation - Extension of current nuclear capacity and associated spent fuel discharge through 2100 with 3.2% growth representing 1.5% market growth (all energy, not just electricity) and 1.7% share growth. Share growth results in tripling market share by 2100 from the current 8.4% to 25%, equivalent to continuing the average market growth of last 50 years for an additional 100 years. Five primary spent fuel management strategies are assessed against each of the energy futures to determine the number of geological repositories needed and how the first repository would be used. The geological repository site at Yucca Mountain, Nevada, has the physical potential to accommodate all the spent fuel that will be generated by the current fleet of domestic commercial nuclear reactors, even with license extensions. If new nuclear plants are built in the future as replacements or additions, the United States will need to adopt spent fuel treatment to extend the life of the repository. Should a significant number of new nuclear plants be built, advanced fuel recycling will be needed to fully manage the spent fuel within a single repository. The analysis also considers the timeframe for most efficient implementation of new spent fuel management strategies. The mix of unprocessed spent fuel and processed high level waste in Yucca Mountain varies with each future and strategy. Either recycling must start before there is too much unprocessed waste emplaced or unprocessed waste will have to be retrieved later with corresponding costs. For each case, the latest date to implement reprocessing without subsequent retrieval is determined.

Brent W. Dixon; Steven J. Piet

2004-10-01

128

Environmental Emissions From Energy Technology Systems: The Total Fuel Cycle  

SciTech Connect

This is a summary report that compares emissions during the entire project life cycle for a number of fossil-fueled and renewable electric power systems, including geothermal steam (probably modeled after The Geysers). The life cycle is broken into Fuel Extraction, Construction, and Operation. The only emission covered is carbon dioxide. (DJE 2005)

San Martin, Robert L.

1989-04-01

129

A fuel cycle assessment guide for utility and state energy planners  

SciTech Connect

This guide, one in a series of documents designed to help assess fuel cycles, is a framework for setting parameters, collecting data, and analyzing fuel cycles for supply-side and demand-side management. It provides an automated tool for entering comparative fuel cycle data that are meaningful to state and utility integrated resource planning, collaborative, and regional energy planning activities. It outlines an extensive range of energy technology characteristics and environmental, social, and economic considerations within each stage of a fuel cycle. The guide permits users to focus on specific stages or effects that are relevant to the technology being evaluated and that meet the user`s planning requirements.

Not Available

1994-07-01

130

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

2012-10-22

131

Development of a Thermal Rankine-Cycle Energy System.  

National Technical Information Service (NTIS)

The development of an implantable Rankine-cycle power system which actuates a left ventricular assist pump is summarized. Although the prototype employs electrical power transmission, the system has been designed within the constraints of utilizing a radi...

F. N. Huffman

1970-01-01

132

University of Minnesota aquifer thermal energy storage (ATES) project report on the second long-term cycle  

SciTech Connect

The technical feasibility of high-temperature (>100{degrees}C (>212{degrees}F)) aquifer thermal energy storage (ATES) in a deep, confined aquifer was tested in a series of experimental cycles at the University of Minnesota's St. Paul field test facility (FTF). This report describes the second long-term cycle (LT2), which was conducted from October 1986 through April 1987. Heat recovery; operational experience; and thermal, chemical, hydrologic, and geologic effects are reported. Approximately 61% of the 9.21 GWh of energy added to the 9.38 {times} 10{sup 4} m{sup 3} of ground water stored during LT2 was recovered. Temperatures of the water stored and recovered averaged 118{degrees}C (244{degrees}F) and 85{degrees}C (185{degrees}F), respectively. Results agreed with previous cycles conducted at the FTF. System operation during LT2 was nearly as planned. Operational experience from previous cycles at the FTF was extremely helpful. Ion-exchange softening of the heated and stored aquifer water prevented scaling in the system heat exchangers and the storage well, and changed the major-ion chemistry of the stored water. Sodium bicarbonate replaced magnesium and calcium bicarbonate as primary ions in the softened water. Water recovered form storage was approximately at equilibrium with respect to dissolved ions. Silica, calcium, and magnesium were significantly higher in recovered water than in injected water. Sodium was significantly lower in water recovered than in water stored.

Hoyer, M.C.; Hallgren, J.P.; Lauer, J.L.; Walton, M.; Eisenreich, S.J.; Howe, J.T.; Splettstoesser, J.F. (Minnesota Geological Survey, St. Paul, MN (United States))

1991-12-01

133

University of Minnesota aquifer thermal energy storage (ATES) project report on the second long-term cycle  

SciTech Connect

The technical feasibility of high-temperature [>100{degrees}C (>212{degrees}F)] aquifer thermal energy storage (ATES) in a deep, confined aquifer was tested in a series of experimental cycles at the University of Minnesota`s St. Paul field test facility (FTF). This report describes the second long-term cycle (LT2), which was conducted from October 1986 through April 1987. Heat recovery; operational experience; and thermal, chemical, hydrologic, and geologic effects are reported. Approximately 61% of the 9.21 GWh of energy added to the 9.38 {times} 10{sup 4} m{sup 3} of ground water stored during LT2 was recovered. Temperatures of the water stored and recovered averaged 118{degrees}C (244{degrees}F) and 85{degrees}C (185{degrees}F), respectively. Results agreed with previous cycles conducted at the FTF. System operation during LT2 was nearly as planned. Operational experience from previous cycles at the FTF was extremely helpful. Ion-exchange softening of the heated and stored aquifer water prevented scaling in the system heat exchangers and the storage well, and changed the major-ion chemistry of the stored water. Sodium bicarbonate replaced magnesium and calcium bicarbonate as primary ions in the softened water. Water recovered form storage was approximately at equilibrium with respect to dissolved ions. Silica, calcium, and magnesium were significantly higher in recovered water than in injected water. Sodium was significantly lower in water recovered than in water stored.

Hoyer, M.C.; Hallgren, J.P.; Lauer, J.L.; Walton, M.; Eisenreich, S.J.; Howe, J.T.; Splettstoesser, J.F. [Minnesota Geological Survey, St. Paul, MN (United States)

1991-12-01

134

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

135

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

136

Solar power satellite life-cycle energy recovery consideration  

Microsoft Academic Search

The construction, in-orbit installation and maintenance of a solar power satellite (SPS) will demand large amounts of energy. As a minimum requirement for an energy effective power satellite it is asked that this amount of energy be recovered. The energy effectiveness in this sense resulting in a positive net energy balance is a prerequisite for cost-effective power satellite. This paper

S. Weingartner; J. Blumenberg

1994-01-01

137

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

138

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

139

Open cycle-ocean thermal energy conversion: Experimental study of flash evaporation  

Microsoft Academic Search

France's Ocean Thermal Energy Conversion program has shown the feasibility and competitiveness of open or closed cycle systems for plants generating less than 20 MWe. The design of a 5 MWe shore-based pilot plant for Tahiti began in 1982. The second stage of the program now in progress will select the most effective cycle for the Tahiti plant. This paper

Thierry Fournier

1985-01-01

140

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

141

Vacuum Deaeration for Ocean Thermal-Energy-Conversion Open-Cycle Applications.  

National Technical Information Service (NTIS)

Seawater deaeration is a process affecting almost all proposed Ocean Thermal Energy Conversion (OTEC) open-cycle power systems. If the noncondensable dissolved air is not removed from a power system, it will accumulate in the condenser, reduce the effecti...

A. Golshani F. C. Chen

1981-01-01

142

78 FR 63518 - Uranium Enrichment Fuel Cycle Inspection Reports Regarding Louisiana Energy Services, National...  

Federal Register 2010, 2011, 2012, 2013

...Uranium Enrichment Fuel Cycle Inspection Reports Regarding Louisiana Energy Services...National Enrichment Facility, Eunice, New Mexico, Prior to the Commencement...NRC staff has prepared inspection reports documenting its findings in...

2013-10-24

143

Life-Cycle Cost Analysis Highlights Hydrogen's Potential for Electrical Energy Storage (Fact Sheet)  

SciTech Connect

This fact sheet describes NREL's accomplishments in analyzing life-cycle costs for hydrogen storage in comparison with other energy storage technologies. Work was performed by the Hydrogen Technologies and Systems Center.

Not Available

2010-11-01

144

New global observations of the terrestrial carbon cycle from GOSAT: Patterns of vegetation fluorescence with gross primary productivity  

NASA Astrophysics Data System (ADS)

Our ability to close the Earth's carbon budget and predict feedbacks in a warming climate depends critically on knowing where, when and how carbon dioxide is exchanged between the land and atmosphere. Terrestrial gross primary production (GPP) constitutes the largest flux component in the global carbon budget, however significant uncertainties remain in GPP estimates and its seasonality. Solar-induced chlorophyll fluorescence is a powerful proxy for assessing biomass photosynthetic activity since photosynthesis and fluorescence are directly coupled processes. This gives rise to re-emission of light between approximately 670 and 780 nm. Passive methods to quantify the fluorescence signal are mainly based on the filling-in of highly saturated O2 absorption structures. This method, however, was mostly applied in field-based measurements and is not directly applicable to space-borne retrievals. We show that variability of aerosols in the atmosphere load and surface pressure cannot be unequivocally disentangled from fluorescence since all these factor impact the absorption depths of O2 lines. This gives rise to biases in the retrieved scattering properties in typical multi-spectral XCO2 retrievals when using the O2 A band but not when focussing solely of solar Fraunhofer lines. We will a) present our retrieval method based on an iterative, non-linear least-squares fitting of Fraunhofer lines, b) discuss the potential impact on XCO2 retrievals and c) show recent fluorescence results from more than one year of GOSAT data. Empirically, we show that global spaceborne observations of solar induced chlorophyll fluorescence exhibit a strong linear correlation with GPP. We found that the fluorescence emission even without any additional meteorological, vegetation type or model information has the same or better predictive skill in estimating GPP as those derived from traditional remotely-sensed vegetation indices using ancillary data and model assumptions. Our results demonstrate that retrievals of chlorophyll fluorescence provide direct global observational constraints for GPP and open an entirely new viewpoint on the global carbon cycle. We anticipate that global fluorescence data in combination with consolidated plant physiological fluorescence models will be a step-change in carbon cycle research and enable an unprecedented robustness in the understanding of the current and future carbon cycle.

Frankenberg, C.; Fisher, J. B.; Lee, J.; Guanter, L.; Van der Tol, C.; Toon, G. C.; kuze, A.; Yokota, T.; Badgley, G. M.; Butz, A.; Jung, M.; Saatchi, S. S.; Worden, J.

2011-12-01

145

The influence of light on nitrogen cycling and the primary nitrite maximum in a seasonally stratified sea  

NASA Astrophysics Data System (ADS)

In the seasonally stratified Gulf of Aqaba Red Sea, both NO2- release by phytoplankton and NH4+ oxidation by nitrifying microbes contributed to the formation of a primary nitrite maximum (PNM) over different seasons and depths in the water column. In the winter and during the days immediately following spring stratification, NO2- formation was strongly correlated (R2 = 0.99) with decreasing irradiance and chlorophyll, suggesting that incomplete NO3- reduction by light limited phytoplankton was a major source of NO2-. However, as stratification progressed, NO2- continued to be generated below the euphotic depth by microbial NH4+ oxidation, likely due to differential photoinhibition of NH4+ and NO2- oxidizing populations. Natural abundance stable nitrogen isotope analyses revealed a decoupling of the ?15N and ?18O in the combined NO3- and NO2- pool, suggesting that assimilation and nitrification were co-occurring in surface waters. As stratification progressed, the ?15N of particulate N below the euphotic depth increased from -5‰ to up to +20‰.N uptake rates were also influenced by light; based on 15N tracer experiments, assimilation of NO3-, NO2-, and urea was more rapid in the light (434 ± 24, 94 ± 17, and 1194 ± 48 nmol N L-1 day-1 respectively) than in the dark (58 ± 14, 29 ± 14, and 476 ± 31 nmol N L-1 day-1 respectively). Dark NH4+ assimilation was 314 ± 31 nmol N L-1 day-1, while light NH4+ assimilation was much faster, resulting in complete consumption of the 15N spike in less than 7 h from spike addition. The overall rate of coupled urea mineralization and NH4+ oxidation (14.1 ± 7.6 nmol N L-1 day-1) was similar to that of NH4+ oxidation alone (16.4 ± 8.1 nmol N L-1 day-1), suggesting that mineralization of labile dissolved organic N compounds like urea was not a rate limiting step for nitrification. Our results suggest that assimilation and nitrification compete for NH4+ and that N transformation rates throughout the water column are influenced by light over diel and seasonal cycles, allowing phytoplankton and nitrifying microbes to contribute jointly to PNM formation. We identify important factors that influence the N cycle throughout the year, including light intensity, substrate availability, and microbial community structure. These processes could be relevant to other regions worldwide where seasonal variability in mixing depth and stratification influence the contributions of phytoplankton and non-photosynthetic microbes to the N cycle.

Mackey, Katherine R. M.; Bristow, Laura; Parks, David R.; Altabet, Mark A.; Post, Anton F.; Paytan, Adina

2011-12-01

146

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

Microsoft Academic Search

Increasingly many 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 patterns, an important problem is de- signing an adaptive duty-cycling mechanism that allows sensor nodes to maintain their power supply at sufficient levels (energy neutral operation) by adapting to changing

Christopher M. Vigorito; Deepak Ganesan; Andrew G. Barto

2007-01-01

147

Energy-Efficient Measures and Life Cycle Costing of a Residential Building in Hong Kong  

Microsoft Academic Search

Energy simulations have been carried out for a residential block of flats. Energy-efficient measures such as using tinted and reflective glass, external shading and wall insulation have been studied. Life cycle cost analysis has been applied to these measures to find out the cost effectiveness. Discounting technique has been used to calculate the present value of energy cost over a

Joseph C. Lam

1993-01-01

148

Integrating occupant preference and life cycle energy evaluation: a simplified method  

Microsoft Academic Search

Building energy evaluation and assessment methods have evolved over the last decades towards sophisticated tools, which can support designers in minimizing building energy use. However, the majority of building energy performance evaluation methods and tools generally do not include a life cycle perspective, choosing to ignore the use of resources associated with the additional materials and systems employed to reduce

Patxi Hernandez; Paul Kenny

2010-01-01

149

Thermodynamic analysis of five compressed-air energy-storage cycles  

Microsoft Academic Search

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

J. A. Fort

1983-01-01

150

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

151

Generation of Energy Optimal Complete Gait Cycles for Biped Robots  

Microsoft Academic Search

Abstract: In this paper we address the problem of energyoptimalgait generation for biped robots. Using a simplied robot dynamics that ignores the eoeects of centripetalforces, we obtain unconstrained optimal trajectoriesgenerated by piecewise constant inputs. Westudy a complete gait cycle comprising single support,double support and the transition phases. The energyoptimal gaits for dioeerent step lengths and velocitiesare compared with natural human

L. Roussel; Carlos Canudas De Wit; Ambarish Goswami

1998-01-01

152

Alternate Cycles Applied to Ocean Thermal Energy Conversion.  

National Technical Information Service (NTIS)

Four open cycle OTEC concepts are described. These are: (1) single, vertical-axis turbine; (2) multiple, horizontal-axis turbines; (3) foam lift/hydraulic turbine; and (4) mist lift/hydraulic turbine. A preliminary assessment of achievable performance is ...

B. Shelpuk A. Lewandowski

1979-01-01

153

Open cycle ocean thermal energy conversion system structure  

Microsoft Academic Search

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

Wittig; J. Michael

1980-01-01

154

ECUT energy data reference series: Otto cycle engines in transportation  

Microsoft Academic Search

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

G. J. Hane; D. R. Johnson

1984-01-01

155

Solar power satellite—Life-cycle energy recovery considerations  

Microsoft Academic Search

The construction, in-orbit installation and maintenance of a solar power satellite (SPS) will demand large amounts of energy. As a minimum requirement for an energy effective power satellite it is asked that this amount of energy be recovered. The energy effectiveness in this sense resulting in a positive net energy balance is a prerequisite for a cost-effective power satellite.This paper

J. Blumenberg

1995-01-01

156

A life cycle impact of the natural gas used in the energy sector in Romania  

Microsoft Academic Search

The world's natural gas consumption continues to grow, increasing its market share of total primary energy consumption. Among the major fuels, natural gas is expected to provide the greatest increase in energy consumption in the world energy sector, due to its relatively low environmental impact and high thermodynamic quality. Natural gas plays a significant role in the energy sector because

Cristian Dinca; Patrick Rousseaux; Adrian Badea

2007-01-01

157

Low-grade geothermal energy conversion by organic Rankine cycle turbine generator  

Microsoft Academic Search

Results of a demonstration project which helped determine the feasibility of converting low-grade thermal energy in 49 C water into electrical energy via an organic Rankine cycle 2500 watt (electrical) turbine-generator are presented. The geothermal source which supplied the water is located in a rural Alaskan village. The reasons an organic Rankine cycle turbine-generator was investigated as a possible source

J. P. Zarling; J. D. Aspnes

1983-01-01

158

Life cycle assessment of electrical and thermal energy systems for commercial buildings  

Microsoft Academic Search

Background, Aim and Scope  The objective of this life cycle assessment (LCA) study is to develop LCA models for energy systems in order to assess the\\u000a potential environmental impacts that might result from meeting energy demands in buildings. The scope of the study includes\\u000a LCA models of the average electricity generation mix in the USA, a natural gas combined cycle (NGCC)

Ayat Osman; Robert Ries

2007-01-01

159

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

160

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

Microsoft Academic Search

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

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

2001-01-01

161

The industrial life cycle of wind energy electrical power generation  

Microsoft Academic Search

This innovation assessment addresses the factors that have influenced the exceptionally lengthy industrial technology life cycle of wind electrical power generation since its inception in the late 19th Century. It then applies the recently developed Accelerated Radical Innovation (ARI) Model to understand the dynamics of this innovation compared to those of other major 18th–20th Century innovations.Despite market pull in the

John P. Dismukes; Lawrence K. Miller; John A. Bers

2009-01-01

162

Total energy-cycle energy and emissions impacts of hybrid electric vehicles  

SciTech Connect

Argonne National Laboratory has begun an analysis of the energy and air emission impacts of hybrid electric vehicles (HEVs) over the entire energy cycle, including manufacturing, operating, and recycling the vehicles and producing their fuel. Phase 1 evaluates series HEVs using lead acid and nickel metal hydride batteries, operating independent of the electricity grid and connected to it, and compares them to conventional ICE vehicles. With efficient electric components, both grid-dependent and grid-independent vehicles are more efficient than their conventional counterpart, though most of the efficiency advantage is gained in slow, lower power operation (e.g., on the federal urban driving schedule). The grid-independent HEV is not clearly superior if it operates part of each day with grid electricity. Finally, estimates of lead emissions for the lead acid battery-powered HEV are significantly lower than suggested elsewhere.

Wang, M.Q.; Plotkin, S.; Santini, D.J.; He, J.; Gaines, L. [Argonne National Lab., IL (United States). Center for Transportation Research; Patterson, P. [Dept. of Energy, Washington, DC (United States). Office of Transportation Technologies

1997-09-17

163

Differences in oxygen uptake but equivalent energy expenditure between a brief bout of cycling and running  

PubMed Central

Background We examined aerobic and anaerobic exercise energy expenditure and excess post-exercise oxygen consumption (EPOC) between a 250 Watt, 1-minute bout of cycling and uphill treadmill running. Methods Fourteen active to well-trained subjects volunteered for the investigation (VO2 max: 57.0 ± 12.9 ml·kg·min-1 cycle; 59.3 ± 13.7 ml·kg·min-1 run; p = 0.44). Anaerobic energy expenditure was estimated from ?blood lactate. Statistical analysis was completed using a paired t-test (mean ± SD). Results Perceived exertion did not differ between exercise bouts (14.0 ± 2.3 cycle; 13.2 ± 2.1 run; p = 0.29). Exercise oxygen uptake was significantly greater for running (41.4 ± 6.9 kJ) compared to cycling (31.7 ± 7.7 kJ) (p = 0.0001). EPOC was not different between cycling and running (p = 0.21) so that exercise oxygen uptake + EPOC was greater for running (103.0 ± 13.5 kJ) as compared to cycling (85.4 ± 20.2 kJ; p = 0.008). Anaerobic energy expenditure was significantly greater for cycling (32.7 ± 8.9 kJ) versus running (22.5 ± 11.1 kJ) (p = 0.009). Aerobic + anaerobic exercise energy expenditure (cycle 64.3 ± 12.2 kJ; run 63.9 ± 10.1 kJ) (p = 0.90) and total energy expenditure (including EPOC; cycle 118.0 ± 21.8 kJ; run 125.4 ± 19.1 kJ; p = 0.36) were similar for cycling and running. Conclusion Oxygen-only measures reveal discrepancy in energy expenditure between cycling and uphill running. Measurements of exercise oxygen uptake, ?blood lactate and a modified EPOC promote the hypothesis of a similarity in exercise and total energy expenditure between 1-minute work-equivalent bouts of cycling and uphill running.

Scott, Christopher B; Littlefield, Nathanael D; Chason, Jeffrey D; Bunker, Michael P; Asselin, Elizabeth M

2006-01-01

164

Energy Expenditure and Plasma F2-Isoprostanes across the Menstrual Cycle  

PubMed Central

Introduction Habitual energy expenditure appears to favorably alter oxidant/antioxidant balance. Sparse evidence suggests that hormones that fluctuate during the menstrual cycle, particularly estrogens, may influence concentrations of oxidative biomarkers and their relation to energy expenditure. Methods We investigated the relation between energy expenditure and plasma free F2-isoprostane concentrations in 259 healthy, regularly menstruating 18 to 44 year old participants of the BioCycle Study. Habitual energy expenditure was measured using a baseline International Physical Activity Questionnaire and categorized as low, moderate, or high. Women were followed for one or two subsequent menstrual cycles. Past-week and past-day physical activity were measured during follow-up using questionnaires and diaries, respectively. F2-isoprostane concentrations were measured in blood samples collected at both menses (approximate cycle day 2; low serum estradiol concentration) and the late follicular phase (approximate cycle day 12; peak estradiol concentration). Generalized estimating equations were used to model the energy expenditure/isoprostane association, adjusting for confounders. Results Habitual energy expenditure was positively associated with F2-isoprostane concentration (adjusted difference in median F2-isoprostane, high versus low energy expenditure: 17.4%; 95% confidence interval [CI] 3.3, 31.4%). This association was not modified by cycle phase (interaction p=0.61) or differences in peak estradiol concentration across women (interaction p=0.20). Past-week and past-day physical activity measures were not associated with F2-isoprostane concentration (category trend p-values 0.50 and 0.18, respectively). Conclusion These results suggest that higher habitual energy expenditure may be associated with higher concentration of F2-isoprostanes in healthy reproductive-aged women. Estradiol concentration changes during the menstrual cycle do not appear to influence this relationship.

Rudra, Carole B.; Wactawski-Wende, Jean; Hovey, Kathleen M.; Browne, Richard W.; Zhang, Cuilin; Hediger, Mary L.; Schisterman, Enrique F.

2011-01-01

165

Low-temperature thermodynamic bottoming cycles for fusion reactors  

Microsoft Academic Search

Possible application of thermodynamic bottoming cycles to fusion reactors is examined. Thermodynamic and cost data for many possible working fluids are incomplete. Geothermal research is the primary source of fluid data. Bottoming cycles should be fully integrated into the energy conversion system to achieve maximum effectiveness. Scavenging by a bottoming cycle of low-level energy may be possible but not attractive

Hansborough

1976-01-01

166

Balloons, Solar Energy and Dyes: An Approach to Primary Science.  

ERIC Educational Resources Information Center

|Presented is a glimpse into how one school has developed and implemented a policy for a primary science program which is wide-ranging with purposeful investigations, frequently of an interdisciplinary nature, crossing subject boundaries. (Author/KC)|

Ashton, Arthur

1980-01-01

167

The design and use of simplepower: a cycle-accurate energy estimation tool  

Microsoft Academic Search

In this paper, we presen t the design and use of a comprehensiv e framework, SimplePower, for ev aluating the effect of high-level algorithmic, architectural, and compilation trade-offs on energy. An execution-driven, cycle-accurate RT lev el energy estimation tool that uses transition sensitive energy models forms the cornerstone of this framework. SimplePower also pro vides the energy consumed in the

Wu Ye; Narayanan Vijaykrishnan; Mahmut T. Kandemir; Mary Jane Irwin

2000-01-01

168

Life cycle inventory energy consumption and emissions for biodiesel versus petroleum diesel fueled construction vehicles.  

PubMed

Substitution of soy-based biodiesel fuels for petroleum diesel will alter life cycle emissions for construction vehicles. A life cycle inventory was used to estimate fuel cycle energy consumption and emissions of selected pollutants and greenhouse gases. Real-world measurements using a portable emission measurement system (PEMS) were made forfive backhoes, four front-end loaders, and six motor graders on both fuels from which fuel consumption and tailpipe emission factors of CO, HC, NO(x), and PM were estimated. Life cycle fossil energy reductions are estimated it 9% for B20 and 42% for B100 versus petroleum diesel based on the current national energy mix. Fuel cycle emissions will contribute a larger share of total life cycle emissions as new engines enter the in-use fleet. The average differences in life cycle emissions for B20 versus diesel are: 3.5% higher for NO(x); 11.8% lower for PM, 1.6% higher for HC, and 4.1% lower for CO. Local urban tailpipe emissions are estimated to be 24% lower for HC, 20% lower for CO, 17% lower for PM, and 0.9% lower for NO(x). Thus, there are environmental trade-offs such as for rural vs urban areas. The key sources of uncertainty in the B20 LCI are vehicle emission factors. PMID:19746743

Pang, Shih-Hao; Frey, H Christopher; Rasdorf, William J

2009-08-15

169

SWECS cost of energy based on life cycle costing  

Microsoft Academic Search

The Small Wind Energy Conversion Systems (SWECS) sizes considered were 1-2 kW, 8 kW, and 40 kW units. Systems costs were based on an assumed sales of 1000 units of each SWECS per year. The results of the LCC analysis show SWECS cost of energy to be competitive with grid electricity costs of energy over the projected lifetimes of the

W. R. Briggs

1980-01-01

170

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

171

Primary energy consumption analysis of residential central air conditioning systems  

Microsoft Academic Search

Energy saving potential in the AC (air conditioning) system is the focus of the researchers all over the world. In China, the main problems in AC systems are the high consumption and low utilization of energy. Enormous energy is consumed by the air conditioning systems of residential buildings, which makes the energy conservation more important. Currently many kinds of central

Wei Bing; Yang Huayi; Wei Zhe

2010-01-01

172

Nuclear Fuel Cycle Information System. An International Directory of Nuclear Fuel Cycle Facilities Prepared at the International Atomic Energy Agency.  

National Technical Information Service (NTIS)

The Nuclear Fuel Cycle Information System (NFCIS) is an international directory of civilian nuclear fuel cycle facilities. Its purpose is to identify existing and planned nuclear fuel cycle facilities throughout the world and to indicate their main parame...

1987-01-01

173

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

174

Simultaneous Detection of High Energy Phosphates and Metabolites of Glycolysis and the Krebs Cycle by HPLC  

Microsoft Academic Search

For the detailed analysis of energy metabolism, a HPLC method is described allowing the single-run separation and quantification of most metabolites from glycolysis and the Krebs cycle including the high energy phosphates. With a detection limit in the picomolar range this method is even applicable when only small sample sizes of tissue are obtained.

Achim M. Vogt; Cordula Ackermann; Tanja Noe; Detlef Jensen; Wolfgang Kübler

1998-01-01

175

Life Cycle Assessment of fossil energy use and greenhouse gas emissions in Chinese pear production  

Microsoft Academic Search

A Life Cycle Assessment (LCA) was performed to analyze environmental consequences of different pear production chains in terms of fossil energy use and greenhouse gas (GHG) emission in China. The assessment identified hotspots that contributed significantly to the environmental impacts of pear production from the cradle to the point of sale. The results showed that GHG emissions and fossil energy

Yuexian Liu; Vibeke Langer; Henning Høgh-Jensen; Henrik Egelyng

2010-01-01

176

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

177

Stoichiometry in Producer-Grazer Systems: Linking Energy Flow with Element Cycling  

Microsoft Academic Search

All organisms are composed of multiple chemical elements such as carbon, nitrogen and phosphorus. While energy flow and element cycling are two fundamental and unifying principles in ecosystem theory, population models usually ignore the latter. Such models implicitly assume chemical homogeneity of all trophic levels by concentrating on a single constituent, generally an equivalent of energy. In this paper, we

Irakli Loladze; Yang Kuang; James J. Elser

2000-01-01

178

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

179

Impact of Nuclear Energy Futures on Advanced Fuel Cycle Options  

SciTech Connect

The Nuclear Waste Policy Act requires the Secretary of Energy to inform Congress before 2010 on the need for a second geologic repository for spent nuclear fuel. By that time, the spent fuel discharged from current commercial reactors will exceed the statutory limit of the first repository. There are several approaches to eliminate the need for another repository in this century. This paper presents a high-level analysis of these spent fuel management options in the context of a full range of possible nuclear energy futures. The analysis indicates the best option to implement varies depending on the nuclear energy future selected.

Dixon, B.W.; Piet, S.J.

2004-10-03

180

Life-Cycle Energy and GHG Emissions for New and Recovered ...  

Treesearch

Description: Within the green building fields is a growing movement to recover and ... This study quantifies the primary energy and greenhouse gas (GHG) ... of wood recovered from an old house and from new wood harvested from the forest  ...

181

Low-grade geothermal energy conversion by organic Rankine cycle turbine generator  

NASA Astrophysics Data System (ADS)

Results of a demonstration project which helped determine the feasibility of converting low-grade thermal energy in 49 C water into electrical energy via an organic Rankine cycle 2500 watt (electrical) turbine-generator are presented. The geothermal source which supplied the water is located in a rural Alaskan village. The reasons an organic Rankine cycle turbine-generator was investigated as a possible source of electric power in rural Alaska are: (1) high cost of operating diesel-electric units and their poor long-term reliability when high-quality maintenance is unavailable and (2) the extremely high level of long-term reliability reportedly attained by commercially available organic Rankine cycle turbines. Data is provided on the thermal and electrical operating characteristics of an experimental organic Rankine cycle turbine-generator operating at a uniquely low vaporizer temperature.

Zarling, J. P.; Aspnes, J. D.

182

A life-cycle cost optimization model with environmental impact assessment for energy management of service buildings  

Microsoft Academic Search

A life-cycle optimization model is presented that minimizes the life-cycle costs of meeting the energy demand of a service building by means of a combination of cogeneration, solar and conventional energy systems. The model output provides optimal operation levels and investment planning as well as the corresponding life-cycle environmental impacts for different operational strategies. The life-cycle impact assessment results of

Amir Safaei; Fausto Freire; Carlos Henggeler Antunes

2012-01-01

183

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

184

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

185

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

PubMed

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. PMID:21482096

Giugliano, Michele; Cernuschi, Stefano; Grosso, Mario; Rigamonti, Lucia

2011-04-08

186

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

187

Analysis of solar-powered absorption cycle heat pumps with internal/external energy storages  

NASA Astrophysics Data System (ADS)

System diagrams and performance equations are presented for solar-powered water-lithium bromide absorption cycle heat pump systems utilizing two different modes of energy storage. In the ETS system the collector is coupled to the absorption cycle generator through a thermal energy storage external to the other elements of the system. In the ILES system the collector is coupled directly to the absorption cycle generator with latent energy storage internal to the cycle itself. Discrete-time computer models of the systems are constructed to enable operational and parameter studies to be carried out. Generalized weather functions are used to represent insolation and building load demands to the systems. Operating strategies to minimize auxiliary energy requirements and to maximize the utilization of solar energy are described for each system. Parameter studies were carried out in terms of system cost and solar energy supply fraction versus storage size and insolation to load ratio (collector area). Comparisons between the ETS and ILES systems show that the greater capital cost of the ILES system is offset by higher solar energy utilization.

Harris, A. W.; Shen, C. N.

188

Energy harvesting based on Ericsson pyroelectric cycles in a relaxor ferroelectric ceramic  

NASA Astrophysics Data System (ADS)

This work deals with energy harvesting from temperature variations. It is shown here that direct pyroelectric energy harvesting (connecting an adapted resistance, for example) is not effective, whereas Ericsson-based cycles give energy 100 times higher. The principle and experimental validation of the Ericsson cycle are shown with the example of 0.90Pb(Mg1/3Nb2/3)O3-0.10PbTiO3 ceramic. Harvested energy reached 186 mJ cm-3 for 50 °C temperature variation and electric field cycle of 3.5 kV mm-1. A correlation between the electrocaloric effect and pyroelectric energy harvesting is then shown. Harvested electric energy with Ericsson cycles can be simply expressed as electrocaloric heat multiplied by Carnot efficiency. Several examples are then given from materials with the highest known electrocaloric effect. This leads to energies of hundreds of mJ cm-3 for a limited 10 °C temperature variation. Compared to Carnot's efficiency, this is much higher than the best thermoelectric materials based on the Seebeck effect.

Sebald, Gael; Pruvost, Sebastien; Guyomar, Daniel

2008-02-01

189

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.

190

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

Microsoft Academic Search

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

K. K. Humphreys; D. R. Brown

1990-01-01

191

Experimental Energy Balance During the First Cycles of Cyclically Loaded Specimens Under the Conventional Yield Stress  

Microsoft Academic Search

This paper, as an extension of Maquin and Pierron (Mech Mater 41(8):928–942, 2009), presents an experimental procedure developed to macroscopically estimate the energy balance during the very first cycles\\u000a of a uniaxially loaded metallic specimen at low stress levels. This energy balance is performed by simultaneously measuring\\u000a the plastic input energy using a load cell and a strain gauge, and

N. Connesson; F. Maquin; F. Pierron

2011-01-01

192

A Bluetooth Radio Energy Consumption Model for Low-Duty-Cycle Applications  

Microsoft Academic Search

This paper presents a realistic model of the radio energy consumption for Bluetooth-equipped sensor nodes used in a low-duty-cycle network. The model is based on empirical energy consumption measurements of Bluetooth modules. This model will give users the possibility to optimize their radio communication with respect to energy consumption while sustaining the data rate. This paper shows that transmission power

Martin C. Ekstrom; Marcus Bergblomma; Maria Linden; Mats Bjorkman; Mikael Ekstrom

2012-01-01

193

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

194

Thermodynamic analysis of five compressed-air energy-storage cycles. [Using CAESCAP computer code  

Microsoft Academic Search

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 particularly 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 in 1982 at the Pacific Northwest Laboratory. This code was

Fort

1983-01-01

195

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

196

Impact of Nuclear Energy Futures on Advanced Fuel Cycle Options.  

National Technical Information Service (NTIS)

The Nuclear Waste Policy Act requires the Secretary of Energy to inform Congress before 2010 on the need for a second geologic repository for spent nuclear fuel. By that time, the spent fuel discharged from current commercial reactors will exceed the stat...

B. W. Dixon S. J. Piet

2004-01-01

197

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

198

Mass and energy balances of the switchgrass-ethanol cycle  

Microsoft Academic Search

The switchgrass process for producing ethanol has received much popular attention. However, a realistic analysis of this process indicates three serious limitations: (a) If switch- grass planted on 130 million hectares (the entire area of active US cropland) were used as feedstock and energy source for ethanol production, the net ethanol yield would replace only about 10% of today's gasoline

Tad W. Patzek

2008-01-01

199

Thermodynamic analysis of five compressed-air energy-storage cycles. [Using CAESCAP computer code  

SciTech Connect

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 particularly 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 in 1982 at the Pacific Northwest Laboratory. This code was designed specifically 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 in this report. The designs analyzed were: conventional CAES; adiabatic CAES; hybrid CAES; pressurized fluidized-bed CAES; and direct coupled steam-CAES. Inputs to the code were based on published reports describing each plant cycle. For each cycle analyzed, CAESCAP calculated the thermodynamic station conditions and individual-component efficiencies, as well as overall cycle-performance-parameter values. These data were then 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

200

Solar wind cross-helicity and residual energy during different solar cycles  

NASA Astrophysics Data System (ADS)

The minimum of solar cycle 23 exhibited anomalous characteristics with respect to its predecessors. Other than differences in the standard indicators of activity, such as sunspots, polar magnetic fields were also found to be different. These differences have a range of effects in the solar wind. In this work we investigate the behavior of the cross-helicity, i.e., the Alfvenicity, and of the residual energy, i.e., the balance between kinetic and magnetic energy, of the magnetic field fluctuations during two fast latitude scans from the solar minima in cycles 22 and 23 using Ulysses data. We find that the differences between the minima are mainly related to the greater prominence of convected structures in the broader equatorial region in cycle 23. For comparison, we have calculated the same parameters at different phases of the solar cycle and in a diverse range of solar wind regimes. We have found that the residual energy is independent of the phase of the solar cycle. We also highlight a dependence of cross-helicity and residual energy on different timescales from ~10 minutes to 10 hours.

Perri, S.; Balogh, A.

2010-12-01

201

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

202

Biologically enhanced energy and carbon cycling on Titan?  

PubMed

With the Cassini-Huygens Mission in orbit around Saturn, the large moon Titan, with its reducing atmosphere, rich organic chemistry, and heterogeneous surface, moves into the astrobiological spotlight. Environmental conditions on Titan and Earth were similar in many respects 4 billion years ago, the approximate time when life originated on Earth. Life may have originated on Titan during its warmer early history and then developed adaptation strategies to cope with the increasingly cold conditions. If organisms originated and persisted, metabolic strategies could exist that would provide sufficient energy for life to persist, even today. Metabolic reactions might include the catalytic hydrogenation of photochemically produced acetylene, or involve the recombination of radicals created in the atmosphere by ultraviolet radiation. Metabolic activity may even contribute to the apparent youth, smoothness, and high activity of Titan's surface via biothermal energy. PMID:16078872

Schulze-Makuch, Dirk; Grinspoon, David H

2005-08-01

203

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

204

Impact of Nuclear Energy Futures on Advanced Fuel Cycle Options  

Microsoft Academic Search

The Nuclear Waste Policy Act requires the Secretary of Energy to inform Congress before 2010 on the need for a second geologic repository for spent nuclear fuel. By that time, the spent fuel discharged from current commercial reactors will exceed the statutory limit of the first repository (63,000 MTiHM commercial, 7,000 MT non-commercial). There are several approaches to eliminate the

Brent W. Dixon; Steven J. Piet

2004-01-01

205

Physics Teaching Technology Resource: Learning Cycle on Energy  

NSDL National Science Digital Library

This video-based experiment employs a pendulum to promote understanding of conservation of mechanical energy. Students explore qualitative ideas in the first video, then expand those ideas through analysis of a second, longer video of a stopped pendulum system. Each video includes learning goal and post-experiment questions. This material is from a collection of similar resources designed to have students mirror the activities of scientists to construct and apply knowledge.

Etkina, Eugenia

2011-11-18

206

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

2013-01-30

207

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

2009-06-23

208

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

209

Energy evaluation of steam-water cycle operation with mathematical modelling application  

NASA Astrophysics Data System (ADS)

In recent years, we can observe the development of the thermal diagnosis and operating control systems based on measuring techniques and mathematical modelling of processes improvement. Evaluation of the actual operating state is insufficient to make an optimal operating decisions. Thus, information about the influence of the operating parameters' deviations from the reference state on indicators describing energy consumption of the process (for example specific heat consumption or specific energy consumption) is also necessary. The paper presents methods for generation the information about the influence of the steam-water cycle operating parameters on specific heat consumption in a turbine's cycle. A mathematical model of steam-water cycle for a CHP (Cogeneration - also Combined Heat and Power) unit is being worked out. Methods for calculation of operating deviations with the application of correction curves and a mathematical model are described. Exemplary calculation results are presented.

Rusinowski, Henryk; Szapajko, Grzegorz

2011-12-01

210

Promoting Knowledge Creation Discourse in an Asian Primary Five Classroom: Results from an Inquiry into Life Cycles  

ERIC Educational Resources Information Center

|The phrase "knowledge creation" refers to the practices by which a community advances its collective knowledge. Experience with a model of knowledge creation could help students to learn about the nature of science. This research examined how much progress a teacher and 16 Primary Five (Grade 4) students in the International Baccalaureate Primary

van Aalst, Jan; Truong, Mya Sioux

2011-01-01

211

Life cycle assessment as a decision support tool for landfill gas-to energy projects  

Microsoft Academic Search

The greenhouse gas (GHG) emissions from MSW landfill, and control methods to eliminate or minimize these impacts including energy recovery from landfill gas (LFG) of MSW landfill in Thailand have been evaluated. Life Cycle Assessment (LCA) is used as the analytical tool to evaluate the environmental consequences of landfilling holistically. The economic implications of the control methods are also briefly

Wanida Wanichpongpan; Shabbir H. Gheewala

2007-01-01

212

Life-cycle assessment of desalination technologies integrated with energy production systems  

Microsoft Academic Search

Desalination technologies require high energy consumption. As a consequence, the environmental load associated with the operating stage is much higher (more than 90%) than that associated to plant construction, maintenance and final disposal. This paper analyzes the evolution of environmental impact by means of the Life-Cycle Assessment (LCA) technique, caused by the most common commercial desalination technologies used worldwide -

R. G. Raluy; L. Serra; J. Uche; A. Valero

2004-01-01

213

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

National Technical Information Service (NTIS)

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 anal...

M. Wang C. Saricks D. Santini

1999-01-01

214

Thermal-cycling tests for a compressed-air energy storage recuperator: Final report  

Microsoft Academic Search

The purpose of this investigation was to validate empirically an analytical procedure used to assess the fatigue life of compressed-air energy storage (CAES) recuperators when subjected to thermal cycling. A previous EPRI research project investigated the problem of thermal fatigue in CAES recuperators using finite-element analysis. This empirical investigation was performed to validate the results of that investigation. A scale

1987-01-01

215

Open cycle solar energy system utilizing buoyancy as a conversion force  

Microsoft Academic Search

An open cycle energy conversion system is described adaptable for use with, inter alia, solar collectors and other sources of available heat for increasing the temperature of a moving gas and employing a substantially vertically positioned gas expanding column comprising an endless arrangement of cups journaled for movement in a closed path in a liquid medium in the column for

Shaw

1977-01-01

216

Falling jet flash evaporators for open cycle ocean thermal energy conversion  

Microsoft Academic Search

Evaporation from falling superheated water jets for application to open cycle ocean thermal energy conversion is considered. Analyses are performed to show that the interfacial resistance is of no importance to evaporator design and that evaporation is liquid side controlled. The heat exchanger performance is presented in terms of its effectiveness and change of bulk temperature. Unbroken planar and round

A. T. Wassel; S. M. Ghiaasiaan

1985-01-01

217

Integration of high temperature thermal energy storage into a solar thermal Brayton cycle power plant  

Microsoft Academic Search

Analytical methods have been developed to support the design and analysis of thermal energy storage (TES) systems for solar thermal power plants employing high temperature Brayton, closed cycle thermal engines with helium or air as the heat transport fluid. System level studies have been undertaken to assess the impact of storage on plant performance, to establish storage system design and

W. D. Beverly; W. W. Engle; F. O. Mahony

1977-01-01

218

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

219

Fan cycling strategies and heat pipe heat exchangers provide energy efficient dehumidification  

Microsoft Academic Search

This article describes two methods to reduce energy consumption and peak demand in buildings that require humidity control that were demonstrated at the Salvador Dali Museum in St. Petersburg, Florida. The first method centered on alternative indoor fan cycling strategies and the second method involved the use of heat pipe heat exchangers. Both approaches increased the dehumidification performance of the

Shirey

1995-01-01

220

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

1997-01-01

221

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

222

Development of silver-zinc cells of improved cycle life and energy density. Final report  

Microsoft Academic Search

This document describes a Small Business Innovative Research (SBIR) Phase II program. The research was designed to improve the cycle life and energy density of silver zinc cells, particularly those used in naval propulsion systems, by advancing the state of the art of the negative electrode and the separator, which are responsible for most of the shortcomings of this electrochemical

Serenyi

1996-01-01

223

Development of silver-zinc cells of improved cycle life and energy density  

Microsoft Academic Search

Substantial increases in the cost effectiveness and range of naval underwater vehicles are possible by virtue of advances made, in this program, to silver-zinc, vehicle propulsion batteries. To improve battery cycle life and energy density, electropermeable membranes (EPM's) were used as additives and\\/or as coatings for the negative electrodes and as coatings for conventional separator materials. Also, bismuth oxide was

Roberto Serenyi; Stanley D. James

1994-01-01

224

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

225

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

226

The Tropical Water and Energy Cycles in a Cumulus Ensemble Model. Part I: Equilibrium Climate  

Microsoft Academic Search

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

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

1994-01-01

227

Energy and Exergy Analyses of a Micro-Steam CCHP Cycle for a Residential Building  

Microsoft Academic Search

In this paper, a CCHP cycle that operates on a micro-steam turbine is introduced to provide the energy requirements of a residential building. The heating and cooling systems are a steam and air heat exchanger (SAHE), and a steam ejector condenser (SEC), respectively. A parametric study is presented to observe the effect of some parameters such as the turbine inlet

Masood Ebrahimi; Ali Keshavarz; Arash Jamali

228

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

229

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

230

An Experimental Project on Energy Education for Rural Women, Primary School Children and Teachers Report.  

ERIC Educational Resources Information Center

One of the University of Baroda's (India) Rural/Tribal Block Placement Program's major aims during the year 1988-89 was to develop energy consciousness in women, primary school children and teachers. An experimental project was designed for a rural Indian village. The objectives were to obtain information on rural energy resources; assess the role…

Pathak, Yogini; Mankodi, Hina

231

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

232

Compressed air energy storage turbomachinery cycle with compression heat recovery, storage, steam generation and utilization during power generation  

Microsoft Academic Search

This patent describes a compressed Air Energy Storage (CAES) plant cycle which utilizes otherwise wasted compression heat by storing such heat in a thermal energy storage (TES) device for subsequent use for steam generation and injection into compressed air flow before entering a high pressure combustion which expands such compressed air to produce additional power. The cycle consists of the

Nakhamkin

1988-01-01

233

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.

234

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

2012-01-18

235

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

SciTech Connect

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 combustion for ethanol; and petroleum use, energy use, and emissions associated with petroleum recovery, petroleum refining, and gasoline combustion for gasoline. For corn-based ethanol, the key factors in determining energy and emissions impacts include energy and chemical usage intensity of corn farming, energy intensity of the ethanol plant, and the method used to estimate energy and emissions credits for co-products of corn ethanol. The key factors in determining the impacts of cellulosic ethanol are energy and chemical usage intensity of biomass farming, ethanol yield per dry ton of biomass, and electricity credits in cellulosic ethanol plants. The results of our fuel-cycle analysis for fuel ethanol are listed below. Note that, in the first half of this summary, the reductions cited are per-vehicle-mile traveled using the specified ethanol/gasoline blend instead of conventional (not reformulated) gasoline. The second half of the summary presents estimated changes per gallon of ethanol used in ethanol blends. GHG emissions are global warming potential (GWP)-weighted, carbon dioxide (CO2)-equivalent emissions of CO2, methane (CH4), and nitrous oxide (N2O).

C. Saricks; D. Santini; M. Wang

1999-02-08

236

Energy spectra of protons and nuclei of primary cosmic rays at energies exceeding 10 TeV  

NASA Astrophysics Data System (ADS)

A nuclear-emulsion technique for determining the chemical composition of primary cosmic rays in the stratosphere is described, and results on protons and nuclei at energies exceeding 10 TeV are reported. Integrated and differential energy spectra of cascades are presented. It is shown that a significant change in the chemical composition of primary cosmic rays at energies exceeding 10 TeV/nucleon results from a sharp increase in the inclination of the proton spectrum as the spectrum of the nuclear component remains unchanged.

Abulova, V. G.; Varkovitskaia, A. Ia.; Zamchalova, E. A.; Zatsepin, V. I.; Mandritskaia, K. V.; Rakobolskaia, I. V.; Sokolskaia, N. V.

1984-11-01

237

Life-cycle energy production and emissions mitigation by comprehensive biogas-digestate utilization.  

PubMed

In the context of global energy shortages and climate change, developing biogas plants with links to agricultural system has become an important strategy for cleaner rural energy and renewable agriculture. In this study, a life-cycle energy and environmental assessment was performed for a biogas-digestate utilization system in China. The results suggest that biogas utilization (heating, illumination, and fuel) and comprehensive digestate reuse are of equal importance in the total energy production of the system, and they also play an important role in systemic greenhouse gas mitigation. Improvement can be achieved in both energy production and emissions mitigation when the ratio of the current three biogas utilization pathways is adjusted. Regarding digestate reuse, a tradeoff between energy and environmental performance can be obtained by focusing on the substitution for top-dressing, base fertilizers, and the application to seed soaking. PMID:22513252

Chen, Shaoqing; Chen, Bin; Song, Dan

2012-04-02

238

Study of the primary cosmic ray composition around the knee of the energy spectrum  

Microsoft Academic Search

A study of the primary cosmic ray composition in the energy range 5s˙1014-5s˙1015 eV is performed through the analysis of the deep underground muons and of the e.m. component of Extensive Air Showers detected in coincidence by the MACRO and EAS-TOP experiments at the Gran Sasso Laboratory. We conclude that: a) pure proton and Iron primary beams are excluded by

M. Aglietta; B. Alessandro; P. Antonioli; F. Arneodo; L. Bergamasco; M. Bertaina; A. Campos Fauth; C. Castagnoli; A. Castellina; C. Cattadori; A. Chiavassa; G. Cini; B. D'Ettorre Piazzoli; G. di Sciascio; W. Fulgione; P. Galeotti; P. L. Ghia; M. Iacovacci; G. Mannocchi; C. Melagrana; C. Morello; G. Navarra; L. Riccati; O. Saavedra; G. C. Trinchero; P. Vallania; S. Vernetto; S. Ahlen; M. Ambrosio; R. Antolini; G. Auriemma; R. Baker; A. Baldini; G. C. Barbarino; B. C. Barish; G. Battistoni; R. Bellotti; C. Bemporad; P. Bernardini; H. Bilokon; V. Bisi; C. Bloise; C. Bower; S. Bussino; F. Cafagna; M. Calicchio; D. Campana; M. Carboni; S. Cecchini; F. Cei; V. Chiarella; R. Cormack; A. Corona; S. Coutu; G. Decataldo; H. Dekhissi; C. Demarzo; M. de Mitri; M. de Vincenzi; A. di Credico; E. Diehl; O. Erriquez; C. Favuzzi; D. Ficenec; C. Forti; P. Fusco; G. Giacomelli; G. Giannini; N. Giglietto; M. Goretti; M. Grassi; P. Green; A. Grillo; F. Guarino; P. Guarnaccia; C. Gustavino; A. Habig; K. Hanson; R. Heinz; J. T. Hong; E. Iarocci; E. Katsavounidis; E. Kearns; S. Klein; S. Kyriazopoulou; E. Lamanna; D. S. Levin; P. Lipari; G. Liu; R. Liu; M. J. Longo; Y. Lu; G. Ludlam; G. Mancarella; G. Mandrioli; A. Margiotta-Neri; A. Marin; A. Marini; D. Martello; A. Marzari Chiesa; P. Matteuzzi; M. N. Mazziotta; D. G. Michael; S. Mikheyev; L. Miller; M. Mittelbrun; P. Monacelli; T. Montaruli; M. Monteno; S. Mufson; J. Musser; D. Nicoló; R. Nolty; S. Nutter; C. Okada; G. Osteria; O. Palamara; S. Parlati; V. Patera; L. Patrizii; B. Pavesi; R. Pazzi; C. W. Peck; J. Petrakis; S. Petrera; N. D. Pignatano; P. Pistilli; A. Rainó; J. Reynoldson; F. Ronga; G. Sanzani; A. Sanzgiri; F. Sartogo; C. Satriano; L. Satta; E. Scapparone; K. Scholberg; A. Sciubba; P. Serra Lugaresi; M. Severi; M. Sitta; P. Spinelli; M. Spinetti; M. Spurio; J. Steele; R. Steinberg; J. L. Stone; L. R. Sulak; A. Surdo; G. Tarlé; V. Togo; V. Valente; C. W. Walter; R. Webb; W. Worstell

1994-01-01

239

Limit Cycle Oscillations of a Nonlinear Piezo-magneto-elastic Structure for Broadband Vibration Energy Harvesting  

Microsoft Academic Search

\\u000a Vibration-based energy harvesting has been investigated by several researchers over the last decade. Typically, devices employing\\u000a piezoelectric, electromagnetic, electrostatic and magnetostrictive transductions have been designed in order to convert ambient\\u000a vibrations into electricity under resonance excitation. Regardless of the transduction mechanism, a primary issue in resonant\\u000a energy harvesters is that the best performance of the device is limited to resonance

A. Erturk; J. Hoffmann; D. J. Inman

240

[Effects of swimming with a wet suit on energy expenditure during subsequent cycling].  

PubMed

The aim of this study was to investigate the effects of swimming with a wetsuit on energy expenditure during subsequent cycling. Nine well-trained triathletes underwent three submaximal trials. The first trial (SC) consisted of a 750-m swim realised at a competition pace, followed by a 10-min cycling exercise at a power output corresponding to the ventilatory threshold . The two other trials were composed of the same cycling exercise, preceded either by a 750-m swim with a wetsuit (WSC) or by a cycling warm-up (Ctrl). The main results are that the WSC trial was characterised by significantly lower swimming cadence (-14%), heart rate (-11%), and lactate values (-47%) compared to the SC trial, p < 0.05. Moreover, cycling efficiency was significantly higher in the WSC trial compared to the SC trial (12.1% difference, p < 0.05). The lower relative intensity observed during swimming with a wetsuit suggest the relative importance of swimming condition on the total performance in a sprint triathlon. PMID:12955864

Delextrat, Anne; Bernard, Thierry; Hausswirth, Christophe; Vercruyssen, Fabrice; Brisswalter, Jeanick

2003-06-01

241

Conceptual Design for Lower-Energy Primary Aluminum  

NASA Astrophysics Data System (ADS)

Operating parameters have been identified such that slag melts typical of other carbothermic aluminum processes are thermodynamically unstable. This facilitates the direct reaction of carbon in carbon-saturated aluminum with alumina under dispersed-contact high-intensity conditions. A conceptual design for one million tonnes per annum (1 Mtpa) aluminum production from Bayer alumina is developed. Freestanding graphite reactors and an ancillary plant encapsulated by inert gas are totally unconstrained within refractory-lined shells. Electrical conductive heating and melt circulation in closed loops, employing a 10 vol pct dispersion of fine carbon particles in aluminum (slurry), transports sensible heat to a single pressurized metal-producing reactor (MPR) to satisfy the endothermicity. In the proposed plant, an MPR at 0.28 MPa (2.8 bar) and 2433 K (2160 °C) with a hearth 2-m-wide × 190-m-long leads the melt via a barometric leg back to essentially atmospheric pressure, for further in-line processing. The impeller-stirred assimilation of fine carbon particles is followed by multistage gas-lift pumping to provide a 5.4-m total head, as required by two parallel straight-line melt-conductive heaters 1 m in diameter × 226 m in length. Overall energy-consumption figures 28.7 pct lower than today’s more recently installed Hall Heroult electrolytic plants are predicted, with 51.3 pct less purchased electricity, supplemented with 1.10 times the stoichiometric elemental carbon.

Warner, N. A.

2008-04-01

242

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

243

Thermochemical cycles for energy storage: Thermal decomposition of ZnSO4 systems  

NASA Astrophysics Data System (ADS)

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 (NH4HSO4) 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, we have shown that when NH4HSO4 is mixed with ZnO and decomposed, the resulting products can be released stepwise (H2O (gaseous) at approximately 163 C, NH3 (gaseous) at 365-418 C, and a mixture of SO2 (gaseous) and SO3 (gaseous) at approximately 900 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 (ZnSO4). We have demonstrated that this reaction can be accelerated and the temperature required reduced by the addition of excess ZnO, V2A5, and possibly other metal oxides.

Wentworth, W. E.

1992-04-01

244

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

NASA Astrophysics Data System (ADS)

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 World Climate Research Program (WCRP). The NRC report, on page 245, highlighted this new initiative as one of the important elements of advancing hydrologic sciences. The four scientific objectives defined for the program at the time were: 1. Determine the hydrological cycle and energy fluxes by global measurements of observable atmospheric and surface properties; 2. Model the hydrological cycle and its effects on the atmosphere, oceans and land surfaces; 3. Develop the ability to predict variation of global and regional hydrological processes and water resources, and their response to environmental change; 4. Advance the development of observing techniques, data management and assimilation systems for operational applications to long-range weather forecasting, hydrologic and climate predictions. It is nearly twenty years since the launch of the GEWEX project. This presentation summarizes the achievements of GEWEX to date and the challenges it faces in the future.

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

2009-12-01

245

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

246

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

2013-03-29

247

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

2013-08-29

248

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

249

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

250

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

251

Life cycle assessment of two emerging sewage sludge-to-energy systems: evaluating energy and greenhouse gas emissions implications.  

PubMed

A "cradle-to-grave" life cycle assessment was conducted to examine the energy and greenhouse gas (GHG) emission footprints of two emerging sludge-to-energy systems. One system employs a combination of anaerobic digestion (AD) and fast pyrolysis for bioenergy conversion, while the other excludes AD. Each system was divided into five process phases: plant construction, sludge pretreatment, sludge-to-bioenergy conversion, bioenergy utilizations and biochar management. Both systems achieved energy and GHG emission benefits, and the AD-involving system performed better than the AD-excluding system (5.30 vs. 0.63 GJ/t sludge in net energy gain and 0.63 vs. 0.47 t CO(2)eq/t sludge in emission credit for base case). Detailed contribution and sensitivity analyses were conducted to identify how and to what degree the different life-cycle phases are responsible for the energy and emission impacts. The energy and emission performances were significantly affected by variations in bioenergy production, energy requirement for sludge drying and end use of bioenergy. PMID:23131626

Cao, Yucheng; Paw?owski, Artur

2012-10-08

252

Life-cycle cost analysis of energy efficiency design options for residential furnaces and boilers  

SciTech Connect

In 2001, the U.S. Department of Energy (DOE) initiated a rulemaking process to consider whether to amend the existing energy efficiency standards for furnaces and boilers. A key factor in DOE's consideration of new standards is the economic impacts on consumers of possible revisions to energy-efficiency standards. Determining cost-effectiveness requires an appropriate comparison of the additional first cost of energy efficiency design options with the savings in operating costs. DOE's preferred approach involves comparing the total life-cycle cost (LCC) of owning and operating a more efficient appliance with the LCC for a baseline design. This study describes the method used to conduct the LCC analysis and presents the estimated change in LCC associated with more energy-efficient equipment. The results indicate that efficiency improvement relative to the baseline design can reduce the LCC in each of the product classes considered.

Lutz, James; Lekov, Alex; Whitehead, Camilla Dunham; Chan, Peter; Meyers,Steve; McMahon, James

2004-01-20

253

Energy and life-cycle cost analysis of a six-story office building  

NASA Astrophysics Data System (ADS)

An energy analysis computer program, DOE-2, was used to compute annual energy use for a typical office building as originally designed and with several energy conserving design modifications. The largest energy use reductions were obtained with the incorporation of daylighting techniques, the use of double pane windows, night temperature setback, and the reduction of artificial lighting levels. A life-cycle cost model was developed to assess the cost-effectiveness of the design modifications discussed. The model incorporates such features as inclusion of taxes, depreciation, and financing of conservation investments. The energy conserving strategies are ranked according to economic criteria such as net present benefit, discounted payback period, and benefit to cost ratio.

Turiel, I.

1981-10-01

254

Hydrogenases and H(+)-reduction in primary energy conservation.  

PubMed

Hydrogenases are metalloenzymes subdivided into two classes that contain iron-sulfur clusters and catalyze the reversible oxidation of hydrogen gas (H(2)[Symbol: see text]left arrow over right arrow[Symbol: see text]2H(+)[Symbol: see text]+[Symbol: see text]2e(-)). Two metal atoms are present at their active center: either a Ni and an Fe atom in the [NiFe]hydrogenases, or two Fe atoms in the [FeFe]hydrogenases. They are phylogenetically distinct classes of proteins. The catalytic core of [NiFe]hydrogenases is a heterodimeric protein associated with additional subunits in many of these enzymes. The catalytic core of [FeFe]hydrogenases is a domain of about 350 residues that accommodates the active site (H cluster). Many [FeFe]hydrogenases are monomeric but possess additional domains that contain redox centers, mostly Fe-S clusters. A third class of hydrogenase, characterized by a specific iron-containing cofactor and by the absence of Fe-S cluster, is found in some methanogenic archaea; this Hmd hydrogenase has catalytic properties different from those of [NiFe]- and [FeFe]hydrogenases. The [NiFe]hydrogenases can be subdivided into four subgroups: (1) the H(2) uptake [NiFe]hydrogenases (group 1); (2) the cyanobacterial uptake hydrogenases and the cytoplasmic H(2) sensors (group 2); (3) the bidirectional cytoplasmic hydrogenases able to bind soluble cofactors (group 3); and (4) the membrane-associated, energy-converting, H(2) evolving hydrogenases (group 4). Unlike the [NiFe]hydrogenases, the [FeFe]hydrogenases form a homogeneous group and are primarily involved in H(2) evolution. This review recapitulates the classification of hydrogenases based on phylogenetic analysis and the correlation with hydrogenase function of the different phylogenetic groupings, discusses the possible role of the [FeFe]hydrogenases in the genesis of the eukaryotic cell, and emphasizes the structural and functional relationships of hydrogenase subunits with those of complex I of the respiratory electron transport chain. PMID:18500479

Vignais, Paulette M

2008-01-01

255

Water Loss Control Using Pressure Management: Life-cycle Energy and Air Emission Effects.  

PubMed

Pressure management is one cost-effective and efficient strategy for controlling water distribution losses. This paper evaluates the life-cycle energy use and emissions for pressure management zones in Philadelphia, Pennsylvania, and Halifax, Nova Scotia. It compares water savings using fixed-outlet and flow-modulated pressure control to performance without pressure control, considering the embedded electricity and chemical consumption in the lost water, manufacture of pipe and fittings to repair breaks caused by excess pressure, and pressure management. The resulting energy and emissions savings are significant. The Philadelphia and Halifax utilities both avoid approximately 130 million liters in water losses annually using flow-modulated pressure management. The conserved energy was 780 GJ and 1900 GJ while avoided greenhouse gas emissions were 50 Mg and 170 Mg a year by Philadelphia and Halifax, respectively. The life-cycle financial and environmental performance of pressure management systems compares favorably to the traditional demand management strategy of installing low-flow toilets. The energy savings may also translate to cost-effective greenhouse gas emission reductions depending on the energy mix used, an important advantage in areas where water and energy are constrained and/or expensive and greenhouse gas emissions are regulated as in California, for example. PMID:23869434

Stokes, Jennifer R; Horvath, Arpad; Sturm, Reinhard

2013-08-08

256

Apparatus for realization of rock exploitation method based on thermodynamic cycles utilizing in situ energy source  

Microsoft Academic Search

An apparatus for the realization of a rock-exploitation method based on thermodynamic cycles utilizing an in-situ energy source including a well with a casing sunk at least as far down as a producing horizon, a string of exploitation pipes having at least one opening at the fluid outlet, and means for varying the heat content of the heat-carrying agent in

I. T. Aladiev; V. K. Fardzinov; G. P. Gukov; E. V. Saperov; K. D. Voskresensky

1980-01-01

257

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

Microsoft Academic Search

A comparative life-cycle energy and emissions (greenhouse gas, CO, NOX, SO2, PM10, 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

Mikhail V. Chester; Arpad Horvath; Samer Madanat

2010-01-01

258

Parking infrastructure: energy, emissions, and automobile life-cycle environmental accounting  

NASA Astrophysics Data System (ADS)

The US parking infrastructure is vast and little is known about its scale and environmental impacts. The few parking space inventories that exist are typically regionalized and no known environmental assessment has been performed to determine the energy and emissions from providing this infrastructure. A better understanding of the scale of US parking is necessary to properly value the total costs of automobile travel. Energy and emissions from constructing and maintaining the parking infrastructure should be considered when assessing the total human health and environmental impacts of vehicle travel. We develop five parking space inventory scenarios and from these estimate the range of infrastructure provided in the US to be between 105 million and 2 billion spaces. Using these estimates, a life-cycle environmental inventory is performed to capture the energy consumption and emissions of greenhouse gases, CO, SO2, NOX, VOC (volatile organic compounds), and PM10 (PM: particulate matter) from raw material extraction, transport, asphalt and concrete production, and placement (including direct, indirect, and supply chain processes) of space construction and maintenance. The environmental assessment is then evaluated within the life-cycle performance of sedans, SUVs (sports utility vehicles), and pickups. Depending on the scenario and vehicle type, the inclusion of parking within the overall life-cycle inventory increases energy consumption from 3.1 to 4.8 MJ by 0.1-0.3 MJ and greenhouse gas emissions from 230 to 380 g CO2e by 6-23 g CO2e per passenger kilometer traveled. Life-cycle automobile SO2 and PM10 emissions show some of the largest increases, by as much as 24% and 89% from the baseline inventory. The environmental consequences of providing the parking spaces are discussed as well as the uncertainty in allocating paved area between parking and roadways.

Chester, Mikhail; Horvath, Arpad; Madanat, Samer

2010-07-01

259

Intercomparison of the seasonal cycle in 200 hPa kinetic energy in AMIP GCM simulations  

SciTech Connect

The 200 hPa kinetic energy is represented by means of the spherical harmonic components for the Atmospheric Model Intercomparison Project (AMIP) simulations, the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis and the European Centre for Medium Range Weather Forecast Reanalysis (ERA). The data used are the monthly mean wind fields from 1979 to 1988. The kinetic energy is decomposed into the divergent (DKE) and rotational (RKE) components and emphasis is placed on examining the former. The two reanalysis data sets show reasonable agreement that is best for the rotational kinetic energy. The largest difference in the divergent kinetic energy occurs during the northern summer. As might be expected, the two analyses are closet in regions where there are sufficient observations such that the effect of the model used in the assimilation cycle are minimized. The observed RKE show only a slight seasonal cycle with a maximum occuring during the northern winter. The DKE, on the other hand, has a very pronounced seasonal cycle with maxima at the solsticial seasons and minima during the equinoctial seasons. The model results show a very large spread in the magnitudes of the RKE and DKE although the models all evince a seasonal variation in phase with that observed. The median values of the seasonal cycle of RKE and DKE for the models are usually superior to those of any individual model. Results are also presented for simulation following the AMIP protocol but using updated versions of the original AMIP entries. In most cases these new integrations show better agreement with the observations.

Boyle, J.S.

1996-10-01

260

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

Microsoft Academic Search

A multi-sensor\\/multi-platform approach to water and energy cycle prediction is demonstrated in an effort to understand the variability and feedback of land surface and atmospheric processes over large space and time scales. Remote sensing-based variables including soil moisture (from AMSR-E), surface heat fluxes (from MODIS) and precipitation rates (from TRMM) are combined with North American Regional Reanalysis derived atmospheric components

M. F. McCabe; E. F. Wood; R. Wójcik; M. Pan; J. Sheffield; H. Gao; H. Su

2008-01-01

261

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

262

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

2011-02-22

263

COMPREHENSIVE ANALYSIS OF CORONAL MASS EJECTION MASS AND ENERGY PROPERTIES OVER A FULL SOLAR CYCLE  

SciTech Connect

The LASCO coronagraphs, in continuous operation since 1995, have observed the evolution of the solar corona and coronal mass ejections (CMEs) over a full solar cycle with high-quality images and regular cadence. This is the first time that such a data set becomes available and constitutes a unique resource for the study of CMEs. In this paper, we present a comprehensive investigation of the solar cycle dependence on the CME mass and energy over a full solar cycle (1996-2009) including the first in-depth discussion of the mass and energy analysis methods and their associated errors. Our analysis provides several results worthy of further studies. It demonstrates the possible existence of two event classes: 'normal' CMEs reaching constant mass for >10 R{sub sun} and {sup p}seudo{sup -}CMEs which disappear in the C3 field of view. It shows that the mass and energy properties of CME reach constant levels and therefore should be measured only above {approx}10 R{sub sun}. The mass density (g/R {sup 2}{sub sun}) of CMEs varies relatively little (< order of magnitude) suggesting that the majority of the mass originates from a small range in coronal heights. We find a sudden reduction in the CME mass in mid-2003 which may be related to a change in the electron content of the large-scale corona and we uncover the presence of a 6 month periodicity in the ejected mass from 2003 onward.

Vourlidas, A.; Howard, R. A. [Naval Research Laboratory, Code 7663, Washington, DC (United States); Esfandiari, E. [Adnet Systems Inc., Rockville, MD (United States); Patsourakos, S. [Department of Physics, Section of Astrogeophysics, University of Ioannina, Ioannina (Greece); Yashiro, S. [Center for Solar and Space Weather, Catholic University of America, Washington, DC (United States); Michalek, G. [Astronomical Observatory of Jagiellonian University, Cracow (Poland)

2010-10-20

264

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

265

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

SciTech Connect

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 reactor parks, and to minimize radioactive wastes, other environmental impacts, and proliferation risks. The limitations of the once-through fuel cycle can be overcome by adopting a closed fuel cycle, in which the irradiated fuel is reprocessed and its components are separated into streams that are recycled into a reactor or disposed of in appropriate waste forms. The recycled fuel is irradiated in a reactor, where certain constituents are partially transmuted into heavier isotopes via neutron capture or into lighter isotopes via fission. Fast reactors are required to complete the transmutation of long-lived isotopes. Closed fuel cycles are encompassed by the Department of Energy?s Advanced Fuel Cycle Initiative (AFCI), to which basic scientific research can contribute. Two nuclear reactor system architectures can meet the AFCI objectives: a ?single-tier? system or a ?dual-tier? system. Both begin with light water reactors and incorporate fast reactors. The ?dual-tier? systems transmute some plutonium and neptunium in light water reactors and all remaining transuranic elements (TRUs) in a closed-cycle fast reactor. Basic science initiatives are needed in two broad areas: ? Near-term impacts that can enhance the development of either ?single-tier? or ?dual-tier? AFCI systems, primarily within the next 20 years, through basic research. Examples: Dissolution of spent fuel, separations of elements for TRU recycling and transmutation Design, synthesis, and testing of inert matrix nuclear fuels and non-oxide fuels Invention and development of accurate on-line monitoring systems for chemical and nuclear species in the nuclear fuel cycle Development of advanced tools for designing reactors with reduced margins and lower costs ? Long-term nuclear reactor development requires basic science breakthroughs: Understanding of materials behavior under extreme environmental conditions Creation of new, efficient, environmentally benign chemical separations methods Modeling and simulation to improve nuclear reaction cross-section data, design new materials and separation system, and propagate uncertainties within the fuel cycle Improvement of proliferation resistance by strengthening safeguards technologies and decreasing the attractiveness of nuclear materials A series of translational tools is proposed to advance the AFCI objectives and to bring the basic science concepts and processes promptly into the technological sphere. These tools have the potential to revolutionize the approach to nuclear engineering R&D by replacing lengthy experimental campaigns with a rigorous approach based on modeling, key fundamental experiments, and advanced simulations.

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

2005-09-01

266

Role of primary sedimentation on plant-wide energy recovery and carbon footprint.  

PubMed

The goal of this paper is to show the effect of primary sedimentation on the chemical oxygen demand (COD) and solids fractionation and consequently on the carbonaceous and energy footprints of wastewater treatment processes. Using a simple rational procedure for COD and solids fraction quantification, we quantify the effects of varying fractions on CO2 and CO2-equivalent mass flows, process energy demand and energy recovery. Then we analysed two treatment plants with similar biological nutrient removal processes in two different climatic regions and quantified the net benefit of gravity separation before biological treatment. In the cases analysed, primary settling increases the solid fraction of COD that is processed in anaerobic digestion, with an associated increase in biogas production and energy recovery, and a reduction in overall emissions of CO2 and CO2-equivalent from power importation. PMID:23985518

Gori, Riccardo; Giaccherini, Francesca; Jiang, Lu-Man; Sobhani, Reza; Rosso, Diego

2013-01-01

267

An evaluation on the life cycle of photovoltaic energy system considering production energy of off-grade silicon  

Microsoft Academic Search

In this study, single-crystalline silicon (c-Si) photovoltaic (PV) cells and residential PV systems using off-grade silicon supplied from semiconductor industries were evaluated from a life cycle point of view. Energy payback time (EPT) of the residential PV system with the c-Si PV cells made of the off-grade silicon was estimated at 15.5 years and indirect CO2 emission per unit electrical

Kazuhiko Kato; Akinobu Murata; Koichi Sakuta

1997-01-01

268

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

269

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

270

University of Minnesota Aquifer Thermal Energy Storage (ATES) project report on the first long-term cycle  

Microsoft Academic Search

The technical feasibility of high-temperature (greater than 100 C) aquifer thermal energy storage (IOTAS) in a deep, confined aquifer was tested in a series of experimental cycles at the University of Minnesota's St. Paul field test facility (FTF). This report describes the additions to the FTF for the long-term cycles and the details of the first long-term cycle (LT1) that

M. Walton; J. P. Hallgren; J. L. Lauer; S. J. Eisenreich; J. T. Howe; J. F. Splettstoesser

1991-01-01

271

Iron-dependent changes in cellular energy metabolism: influence on citric acid cycle and oxidative phosphorylation.  

PubMed

Iron modulates the expression of the critical citric acid cycle enzyme aconitase via a translational mechanism involving iron regulatory proteins. Thus, the present study was undertaken to investigate the consequences of iron perturbation on citric acid cycle activity, oxidative phosphorylation and mitochondrial respiration in the human cell line K-562. In agreement with previous data iron increases the activity of mitochondrial aconitase while it is reduced upon addition of the iron chelator desferrioxamine (DFO). Interestingly, iron also positively affects three other citric acid cycle enzymes, namely citrate synthase, isocitric dehydrogenase, and succinate dehydrogenase, while DFO decreases the activity of these enzymes. Consequently, iron supplementation results in increased formation of reducing equivalents (NADH) by the citric acid cycle, and thus in increased mitochondrial oxygen consumption and ATP formation via oxidative phosphorylation as shown herein. This in turn leads to downregulation of glucose utilization. In contrast, all these metabolic pathways are reduced upon iron depletion, and thus glycolysis and lactate formation are significantly increased in order to compensate for the decrease in ATP production via oxidative phosphorylation in the presence of DFO. Our results point to a complex interaction between iron homeostasis, oxygen supply and cellular energy metabolism in human cells. PMID:10556622

Oexle, H; Gnaiger, E; Weiss, G

1999-11-10

272

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

273

Fuel cycle framework for evaluating greenhouse gas emission reduction technology.  

National Technical Information Service (NTIS)

Energy-related greenhouse gas (GHG) emissions arise from a number of fossil fuels, processes and equipment types throughout the full cycle from primary fuel production to end-use. Many technology alternatives are available for reducing emissions based on ...

W. B. Ashton D. W. Barns R. A. Bradley

1990-01-01

274

Determination for dry layer resistance of sucrose under various primary drying conditions using a novel simulation program for designing pharmaceutical lyophilization cycle.  

PubMed

Dry layer resistance, which is the resistance of dried cake against water vapor flow generated from sublimation, is one of the important parameters to predict maximum product temperature and drying time during primary drying in lyophilization. The purpose of this study was to develop the predictive model of dry layer resistance under various primary drying conditions using the dry layer resistance obtained from a preliminary lyophilization run. When the maximum dry layer resistance was modified under the assumption that the chamber pressure is zero, the modified dry layer resistance, which is defined as specific dry layer resistance, correlated well with the sublimation rate. From this correlation, the novel predictive model including the empirical formula of sublimation rate and specific dry layer resistance is proposed. In this model, the dry layer resistance under various conditions of shelf temperature and chamber pressure was successfully predicted based on the relationship of the sublimation rate and specific dry layer resistance of the edge and center vials obtained from the product temperature in one preliminary cycle run. It is expected that this predictive model could be a practical and useful tool to predict product temperature during primary drying. PMID:23684561

Kodama, Tatsuhiro; Sawada, Hiroyuki; Hosomi, Hiroshi; Takeuchi, Masahito; Wakiyama, Naoki; Yonemochi, Etsuo; Terada, Katsuhide

2013-05-15

275

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…

Krauskopf, Sara

2010-01-01

276

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

277

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

278

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

279

Quantitative evaluation of closed-cycle Ocean Thermal Energy Conversion (OTEC) technology in central station applications  

SciTech Connect

The results of an independent quantitative evaluation by Rand of Ocean Thermal Energy Conversion (OTEC) for central station applications are summarized. The methodology developed and implemented for the quantitative analysis of cost sensitivities and engineering uncertainties provides the Office of Energy Research (OER) with the capability for evaluating the effects of alternative OTEC R and D strategies. The analysis also provides a general quantitative approach to assess advanced energy technologies. This study focuses on closed-cycle OTEC for delivery of electric power to the United States. Performance and costs of complete commercial OTEC systems are analyzed at the system level using inputs from component analyses and thermal-resource data for sites in the Gulf of Mexico. Such sites could feed the Gulf Coast from the west coast of Florida to the New Orleans areas. In this evaluation, the energy conversion analysis, i.e., the study of the power system, is based on a thermodynamic analysis of the complete system, which includes allowances for losses in all circuits. A cost-minimization scheme is used to ensure that the cycle component choices are near optimal. To make these cost-minimization calculations, cost algorithms are developed for the principal components. Off-design operations are of great importance in the Gulf of Mexico because of significant seasonal surface temperature variations and the quite large resulting variations of output power. These effects are accounted for in this study by calculating the off-design performance of the power systems and by selecting the cycle that maximizes the average power over the year. Capital cost estimates are made for the complete system. (WHK)

Gritton, E.C.; Pei, R.Y.; Aroesty, J.; Balaban, M.M.; Gazley, C.; Hess, R.W.; Krase, W.H.

1980-05-01

280

Development of silver-zinc cells of improved cycle life and energy density. Final report  

SciTech Connect

This document describes a Small Business Innovative Research (SBIR) Phase II program. The research was designed to improve the cycle life and energy density of silver zinc cells, particularly those used in naval propulsion systems, by advancing the state of the art of the negative electrode and the separator, which are responsible for most of the shortcomings of this electrochemical couple. Yardney relied on a new class of materials, known as Electro-Permeable Membranes, which were used as additives and/or coatings for the negative electrodes and also as coatings for conventional separator materials, such as cellophane and Celgard (microporous polypropylene). In addition, the use of bismuth oxide in conjunction with other additives to the negative electrode was shown to have a beneficial effect on cycle life and to reduce the hydrogen gassing of charged cells by up to 70%.

Serenyi, R.

1996-04-01

281

Eddy Flux Tower in Ankasa Park : a new facility for the study of the carbon cycle of primary tropical forests in Africa  

Microsoft Academic Search

An Eddy Covariance station for the monitoring of CO2 and energy fluxes over a primary tropical forest in Ghana is operative as part of the CarboAfrica eddy covariance network. The facility, located in the Ankasa Conservation area (05° 16' 11.2''N; 02° 41' 41.55'' W), includes a 65 m tall steel tower equipped with a system enabling the measurements of fluxes

P. Stefani; L. Belelli Marchesini; C. Consalvo; A. Forgione; A. Bombelli; E. Grieco; F. Mazzenga; E. Vittorini; D. Papale; R. Valentini

2009-01-01

282

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

283

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

NASA Astrophysics Data System (ADS)

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.

1990-01-01

284

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

285

Studies of slow-positron production using low-energy primary electron beams.  

SciTech Connect

Slow-positron beams produced from negative-work-function solid-state moderators have found numerous applications in condensed matter physics. There are potential advantages in using low-energy primary electron beams for positron production, including reduced radiation damage to single-crystal moderators and reduced activation of nearby components. We present numerical calculations of positron yields and other beam parameters for various target-moderator configurations using the Argonne Wakefield Accelerator (AWA) [1] and Advanced Photon Source (APS) [2] electron linacs [3] as examples of sources for the primary electron beams. The status of experiments at these facilities is reviewed.

Lessner, E.

1999-04-20

286

Dynamical Cycles in Charge and Energy for Iron Ions Accelerated in a Hot Plasma  

NASA Astrophysics Data System (ADS)

We consider a unified model of Fe ion acceleration in the solar corona. The model comprises charge-changing processes, Coulomb energy losses, and both regular and stochastic acceleration. At a given acceleration scenario, the type of acceleration is found to have a minor effect on the mean charge states, but the shapes of the charge-state distributions produced by regular acceleration and by stochastic acceleration are different. During a continual acceleration at coronal temperatures, iron ions typically follow rising trajectories on the charge-energy plane. These trajectories are situated below the mean equilibrium charge curve defined from the balance of ionization and recombination at fixed energy. During stopping, the iron ions cross the equilibrium charge curve and run through a series of charge states above the mean equilibrium charge at current energy, because the Coulomb deceleration rate significantly exceeds the rate of the ion recombination in a hot plasma. As a result, the variety of possible trajectories on the ion charge-energy plane turns out to be much wider than would be expected based on the equilibrium charge-state approximation. In particular, we find dynamical cycles in charge and energy, so that accelerated and highly stripped ions may reappear at low energies. We also find that the equilibrium charge curve cannot be reproduced without strong reduction in the total number of accelerated particles. This implies that the observed iron charge-state distributions essentially depend on the scenario of their acceleration and transport.

Kocharov, L.; Kovaltsov, G. A.; Torsti, J.

2001-08-01

287

Effect of solar wind structure on magnetospheric energy supply during solar cycle 20  

SciTech Connect

The energy supplied to the magnetosphere by the solar wind has been estimated by computing the incremental energy build up in a simple magnetotail model as a result of magnetic flux transfer from the dayside via reconnection. A method utilizing the auroral AL index as a quantitative measure of the flux transfer process and, hence, the magnetospheric energy supply is presented. In this way the available AL records are examined for the purpose of determining the variation in energy input from the solar wind and its relationship to interplanetary conditions during 9 years of solar cycle 20 (1966--1974). The principal feature discerned on shorter time scales was a large modulation of the input energy with sector structure, while in the annual averages enhancements were observed in 1968, 1973, and 1974 of 19%, 33%, and 60% over the 1966--1972 mean of 3 x 10/sup 25/ ergs/yr. Interpreting these results as being due to variations in the time history of the dawn-dusk component of the interplanetary electric field in magnetospheric coordinates, B/sub z//sup -/V, leads to the conclusion that while on shorter intervals the energy supply is dominated by variations in B/sub z//sup -/, associated with both the IMF and the orientation of the terrestrial dipole, on the time scale of years B/sub z//sup -/ changes are small compared with the solar cycle variation in V which clearly produced the increase in 1973--1974 as has been concluded in other studies using techniques different from the one employed here.

Holzer, R.E.; Slavin, J.A.

1981-02-01

288

Forest productivity under elevated CO? and O?: positive feedbacks to soil N cycling sustain decade-long net primary productivity enhancement by CO?.  

PubMed

The accumulation of anthropogenic CO? in the Earth's atmosphere, and hence the rate of climate warming, is sensitive to stimulation of plant growth by higher concentrations of atmospheric CO?. Here, we synthesise data from a field experiment in which three developing northern forest communities have been exposed to factorial combinations of elevated CO? and O?. Enhanced net primary productivity (NPP) (c. 26% increase) under elevated CO? was sustained by greater root exploration of soil for growth-limiting N, as well as more rapid rates of litter decomposition and microbial N release during decay. Despite initial declines in forest productivity under elevated O?, compensatory growth of O? -tolerant individuals resulted in equivalent NPP under ambient and elevated O?. After a decade, NPP has remained enhanced under elevated CO? and has recovered under elevated O? by mechanisms that remain un-calibrated or not considered in coupled climate-biogeochemical models simulating interactions between the global C cycle and climate warming. PMID:21981597

Zak, Donald R; Pregitzer, Kurt S; Kubiske, Mark E; Burton, Andrew J

2011-10-10

289

Energy spectra of proton and nuclei of primary cosmic rays in energy region 10 TeV/particle  

NASA Astrophysics Data System (ADS)

To investigate the chemical composition of primary cosmic rays, several emulsion chambers were exposed at a 10.8 g/sq cm. depth in the stratosphere. Each chamber has the area of 0.92x0.46 sq m. and the depth of 14 c.u. The exposure time of chambers processed by now is 260 hours. The detecting layers were X-ray films and nuclear emulsions, which allowed to measure an energy of cascade and a type of primary particle. Results and techniques are described.

Mandritskaya, K. V.; Sazhina, G. P.; Sokolskaya, N. V.; Varkovitskaya, A. Y.; Zamchalova, E. A.; Zatsepin, V. I.

1985-08-01

290

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

291

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

292

Reducing MCM levels in human primary T cells during the G0->G1 transition causes genomic instability during the first cell cycle  

PubMed Central

DNA replication is tightly regulated, but paradoxically there is reported to be an excess of MCM DNA replication proteins over the number of replication origins. Here, we show that MCM levels in primary human T cells are induced during the G0?G1 transition and are not in excess in proliferating cells. The level of induction is critical as we show that a 50% reduction leads to increased centromere separation, premature chromatid separation (PCS) and gross chromosomal abnormalities typical of genomic instability syndromes. We investigated the mechanisms involved and show that a reduction in MCM levels causes dose-dependent DNA damage involving activation of ATR & ATM and Chk1 & Chk2. There is increased DNA mis-repair by non-homologous end joining (NHEJ) and both NHEJ and homologous recombination are necessary for Mcm7-depleted cells to progress to metaphase. Therefore, a simple reduction in MCM loading onto DNA, which occurs in cancers as a result of aberrant cell cycle control, is sufficient to cause PCS and gross genomic instability within one cell cycle.

Orr, SJ; Gaymes, T; Ladon, D; Chronis, C; Czepulkowski, B; Wang, R; Mufti, GJ; Marcotte, EM; Thomas, NSB

2012-01-01

293

A novel role for Fanconi anemia (FA) pathway effector protein FANCD2 in cell cycle progression of untransformed primary human cells.  

PubMed

Fanconi Anemia (FA) is a cancer-susceptibility syndrome characterized by cellular sensitivity to DNA inter-strand cross-link (ICL)-inducing agents. The Fanconia Anemia D2 (FANCD2) protein is implicated in repair of various forms of DNA damage including ICLs. Studies with replicating extracts from Xenopus eggs indicate a role for FANCD2 in processing and repair of DNA replication-associated double stranded breaks (DSB). We have investigated the role of FANCD2 in cell cycle progression of cultured human cells. Similar to Xenopus cell-free extracts, we show that chromatin association of FANCD2 in human cells is coupled to ongoing DNA replication. siRNA depletion experiments demonstrate that FANCD2 is necessary for efficient DNA synthesis. However, in contrast with Xenopus extracts, FANCD2-deficiency does not elicit a DNA damage response, and does not affect the elongation phase of DNA synthesis, suggesting that FANCD2 is dispensable for repair of replication-associated DNA damage. Using synchronized cultures of primary untransformed human dermal fibroblasts we demonstrate that FANCD2 is necessary for efficient initiation of DNA synthesis. Taken together, our results suggest a novel role for the FA pathway in regulation of DNA synthesis and cell cycle progression. Inefficient DNA replication may contribute to the genome instability and cancer-propensity of FA patients. PMID:20519958

Song, Ihn Young; Barkley, Laura R; Day, Tovah A; Weiss, Robert S; Vaziri, Cyrus

2010-06-15

294

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

295

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

296

Development of silver-zinc cells of improved cycle life and energy density  

NASA Astrophysics Data System (ADS)

Substantial increases in the cost effectiveness and range of naval underwater vehicles are possible by virtue of advances made, in this program, to silver-zinc, vehicle propulsion batteries. To improve battery cycle life and energy density, electropermeable membranes (EPM's) were used as additives and/or as coatings for the negative electrodes and as coatings for conventional separator materials. Also, bismuth oxide was tested as an additive to the negative electrodes and P2291-40/20, a radiation-grafted polyethylene film, as a separator used in conjunction with silver-treated cellophane. EPM's used as negative electrode additives and also as coatings for Celgard 2500 microporous polypropylene greatly improved cells. Cells with EPM's used as coatings for the negative electrodes failed rapidly because of an error in formulation. Cells with 10 percent bismuth oxide in the negative electrodes exhibited substantially lower capacity than the standard cells and were removed from the test. Cells with radiation-grafted polyethylene separators provided fewer cycles than the standard cells, with 5 percent higher capacity and 6 percent lower utilization of active materials by cycle 60. However, the slightly better capacity of these cells, realized due to the additional space available for active materials, does not compensate for their generally unimpressive performance.

Serenyi, Roberto; James, Stanley D.

1994-03-01

297

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

298

Feedbacks between Vegetation and the Water and Energy Cycles in Semiarid Regions  

NASA Astrophysics Data System (ADS)

Despite their large presence on the Earth's surface, semiarid ecosystems are poorly represented in land-surface models. This is primarily because the vegetation dynamics in these models were developed from an understanding of energy-limited ecosystems richer in biomass. Only recently have scientific and modeling communities pushed for emphasis on semiarid ecosystems to better predict the behavior and functioning of these ecosystems under global environmental change and to enhance our understanding of their contribution to global water and energy cycling. In semiarid regions worldwide, coupled biosphere-atmosphere models have demonstrated how interactions between vegetation and the atmosphere can influence climate variability at the macro-scale. Additionally, micro-scale variability in vegetation can exert a strong influence on macro-scale processes. Positive feedbacks between vegetation and the water and energy cycles at the micro-scale may have the ability to elicit responses with important macro-scale consequences. Integrating these feedbacks at different scales remains a challenge in semiarid ecohydrology. Previous research argues for the importance of deep soil moisture (> 20 cm) in dryland ecosystems. Land-surface models often view soil moisture in one "bucket", where the moisture is uniformly distributed throughout the bucket. If deep soil moisture is the critical driver of water and energy dynamics in semiarid ecosystems, the vertical distribution of soil moisture must be captured to accurately represent what is occurring in the ecosystems. Therefore, we have developed a paradigm for environmental controls on water and energy cycling in semiarid ecosystems based on the presence or absence of moisture in two soil layers: a surface layer: 0 - 20 cm, and a deep layer: 20 - 60 cm. These two soil zones can be used to divide soil moisture into four cases. In Case 1, both the surface layer and the deep layer are dry, as after extended periods without rain. In Case 2, the surface layer is wet and the deep layer is dry, as after small storms. In Case 3, the surface layer is wet and the deep layer is wet, as immediately after a series of large storms. In Case 4, the surface layer is dry and the deep layer is wet, as the shallow soil dries a few days following a large storm. These cases are meant to be simple and serve as a framework for the development of hypotheses. This is the framework used to guide the data collection, data analysis and modeling approach for this study. Our work integrates field observations and modeling to test hypotheses regarding the feedbacks between vegetation and the water and energy cycles at the micro-scale. Findings from field observations are used to develop a two-layer ecohydrological bucket model and then couple it with a cellular automata model to explore synergies between micro- and macro-scale feedbacks between vegetation and the water and energy cycles. Here, we address two main questions: (1) what is the influence of the vertical distribution of soil moisture on evapotranspiration dynamics in semiarid regions? (2) what is the influence of the vertical distribution of soil moisture on albedo in semiarid regions?

Papuga, S. A.; Sanchez-Mejia, Z. M.; Neal, A. L.

2011-12-01

299

Energy spectrum of cosmic ray primaries at super high energies estimated from the recent balloon-borne calorimeter measurements  

NASA Astrophysics Data System (ADS)

The energy spectrum of primary cosmic ray particles is determined from the analysis of the chemical composition data of high energy cosmic rays using data obtained by the Japanese American cooperative emulsion experiments for proton and helium intensities and the Goddard Space Flight Center measurements for cosmic ray nuclei. The results indicate that no pronounced changes in the abundance ratios occur at high energies. The total primary spectrum in the range 2-300 TeV is calculated and follows the form N(E)dE = 2.24 x 10 to the 4th (E to the -2.7th)dE, where E is the energy expressed in GeV nucleons and N(E) is the intensity expressed in 1/(sq m s sr GeV/nucleon). The sea level proton and neutron spectra are estimated from this primary spectrum as the source of nucleons near the top of the atmosphere using the Feynman scaling hypothesis and the conventional nucleon-atmospheric diffusion equation. It is found that the derived spectra are in accord with previously measured proton and neutron spectra.

Bhattacharyya, D. P.

1983-03-01

300

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

301

High energy cosmic ray physics with underground muons in MACRO. II. Primary spectra and composition  

Microsoft Academic Search

Multimuon data from the MACRO experiment at Gran Sasso have been analyzed using a new method, which allows one to estimate the primary cosmic ray fluxes. The estimated all-particle spectrum is higher and flatter than the one obtained from direct measurements but is consistent with EAS array measurements. The spectral indexes of the fitted energy spectrum are 2.56+\\/-0.05 for E5000

M. Ambrosio; R. Antolini; G. Auriemma; R. Baker; A. Baldini; G. C. Barbarino; B. C. Barish; G. Battistoni; R. Bellotti; C. Bemporad; P. Bernardini; H. Bilokon; V. Bisi; C. Bloise; T. Bosio; C. Bower; S. Bussino; F. Cafagna; M. Calicchio; D. Campana; M. Carboni; M. Castellano; S. Cecchini; F. Cei; V. Chiarella; A. Corona; S. Coutu; G. De Cataldo; H. Dekhissi; C. De Marzo; I. De Mitri; M. De Vincenzi; A. Di Credico; O. Erriquez; R. Fantini; C. Favuzzi; C. Forti; P. Fusco; G. Giacomelli; G. Giannini; N. Giglietto; M. Goretti; M. Grassi; A. Grillo; F. Guarino; P. Guarnaccia; C. Gustavino; A. Habig; K. Hanson; A. Hawthorne; R. Heinz; J. T. Hong; E. Iarocci; E. Katsavounidis; E. Kearns; S. Kyriazopoulou; E. Lamanna; D. S. Levin; P. Lipari; N. P. Longley; M. J. Longo; G. Mancarella; A. Margiotta-Neri; A. Margiotta-Neri; D. Martello; A. Marzari-Chiesa; M. N. Mazziotta; D. G. Michael; S. Mikheyev; L. Miller; P. Monacelli; T. Montaruli; M. Monteno; S. Mufson; J. Musser; D. Nicolo; R. Nolty; C. Okada; C. Okada; G. Osteria; O. Palamara; S. Parlati; V. Patera; L. Patrizii; R. Pazzi; C. W. Peck; S. Petrera; P. Pistilli; V. Popa; A. Raino; J. Reynoldson; M. Ricciardi; F. Ronga; U. Rubizzo; A. Sanzgiri; F. Sartogo; C. Satriano; L. Satta; E. Scapparone; K. Scholberg; A. Sciubba; P. Serra-Lugaresi; M. Severi; M. Severi; P. Spinelli; M. Spinetti; M. Spinetti; R. Steinberg; J. L. Stone; J. L. Stone; A. Surdo; G. Tarle; V. Valente; C. W. Walter; R. Webb

1997-01-01

302

US nonrenewable conventional primary energy resources as of year-end 1982  

SciTech Connect

Estimates are made of the remaining amounts of US nonrenewable conventional primary energy resources as of the end of 1982. Tables present the holdings in the area of natural gas, crude oil, coal, and uranium. Attention is also given to those potentially additional supplies of natural gas and natural gas liquids and additional crude oil. A final table projects the life expectancy of US fossil fuels at various demand rates. 7 tables.

Not Available

1983-11-07

303

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

304

Seasonality and seasonal affective disorder (SAD): an evolutionary viewpoint tied to energy conservation and reproductive cycles.  

PubMed

The characteristic symptoms of SAD, including hypersomnia and weight gain, might reflect a genetically programmed attempt to conserve energy during historically predictable periods of dwindling food supply. While this basic hypothesis has obvious conceptual appeal, few authors have considered the specific positive selection pressures that might have contributed to such a process. The goal of the current paper is to further develop an evolutionary model of SAD with a focus on energy conservation in the context of seasonal reproductive cycles. To accomplish this, seasonal data on birth rates are considered from an evolutionary viewpoint. There is considerable indirect evidence that in temperate climates, the symptoms of SAD reflect a predisposition for conception to occur in late spring/early summer to ensure a peak of births in the late winter/early spring. The adaptive value of such a pattern, and its putative role in natural selection in humans, is also discussed. PMID:15927269

Davis, Caroline; Levitan, Robert D

2005-07-01

305

Consequences of the cultivation of energy crops for the global nitrogen cycle.  

PubMed

In this paper, we assess the global consequences of implementing first- and second-generation bioenergy in the coming five decades, focusing on the nitrogen cycle. We use a climate mitigation scenario from the Organization for Economic Cooperation and Development's (OECD) Environmental Outlook, in which a carbon tax is introduced to stimulate production of biofuels from energy crops. In this scenario, the area of energy crops will increase from 8 Mha in the year 2000 to 270 Mha (14% of total cropland) and producing 5.6 Pg dry matter per year (12% of energy use) in 2050. This production requires an additional annual 19 Tg of N fertilizer in 2050 (15% of total), and this causes a global emission of 0.7 Tg of N2O-N (8% of agricultural emissions), 0.2 Tg NO-N (6%), and 2.2 Tg of NH3-N (5%). In addition, we project that 2.6 Tg of NO3(-)-N will leach from fields under energy crops. The emissions of N2O may be an important term in the greenhouse gas balance of biofuels produced from energy crops. PMID:20349833

Bouwman, A F; Van Grinsven, J J M; Eickhout, B

2010-01-01

306

Trigeneration primary energy saving evaluation for energy planning and policy development  

Microsoft Academic Search

Trigeneration or combined heat, cooling and power (CHCP) is becoming an increasingly important energy option, particularly on a small-scale basis (below 1MWe), with several alternatives nowadays available for the cooling power production and the coupling to cogeneration systems. This paper deals with the introduction of a suitable framework for assessing the energy saving performance of trigeneration alternatives, orientated towards energy

Gianfranco Chicco; Pierluigi Mancarella

2007-01-01

307

Federal Financial Interventions and Subsidies in Energy Markets 1999: Primary Energy.  

National Technical Information Service (NTIS)

In May 1999, the Office of Policy, U.S. Department of Energy (DOE), asked the Energy Information Administration (EIA) to prepare an update of EIA's 1992 Service Report on Federal energy subsidies, using a more specific definition of subsidies provided by ...

1999-01-01

308

Understanding and Predicting Water and Energy Cycle Changes in NOAA Climate Program  

NASA Astrophysics Data System (ADS)

The NOAA Climate Program leads and coordinates climate activities across all line offices in NOAA. The objectives of NOAA Climate Program are: 1) to describe and understand the state of the climate system through integrated observations, monitoring, and data management, 2) to understand and predict climate variability and change from weeks to decades to a century, and 3) to improve the ability of society to plan for and respond to climate variability and change. The NOAA Climate Program consists of three major programs: Climate Observation and Monitoring, Climate Research and Modeling and Climate Service Development. Understanding and predicting water & energy cycle variability and changes and their consequences to the society have been major undertaking within NOAA Climate Program. Climate variability and change profoundly influence the health, prosperity, and well-being of the people of the United States, as well as all other nations of the world, with vital global economic and security implications. NOAA Climate Program is currently working on a new strategy to develop an improved capability and better climate services to plan for and adapt to climate variability and change. Understanding and predicting water & energy cycle variability and changes will be an important component in NOAA's new strategy for improved climate services. NOAA is willing to work with national and international partners to improve climate services in the changing climate.

Koblinsky, C. J.

2008-05-01

309

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

310

Energy price indices and discount factors for life-cycle cost analysis 1995. Annual supplement to NIST handbook 135 and NBS special publication 709. (Revised)  

Microsoft Academic Search

This is the 1995 annual edition of energy price indices and discount factors for performing life-cycle cost analyses of energy conservation and renewable energy projects. It supports the Federal life-cycle costing methodology by updating the energy price projections and discount factors that are described, explained, and illustrated in the National Institute of Standards and Technology (NIST) Handbook 135 (HB 135).

1994-01-01

311

Arabidopsis Mutants Define a Central Role for the Xanthophyll Cycle in the Regulation of Photosynthetic Energy Conversion  

Microsoft Academic Search

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.

Krishna K. Niyogi; Arthur R. Grossman; Olle Björkman

1998-01-01

312

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

313

Life Cycle Inventories for the Nuclear and Natural Gas Energy Systems, and Examples of Uncertainty Analysis (14 pp)  

Microsoft Academic Search

Goal, Scope and Background. The energy systems included in the ecoinvent database v1.1 describe the situation around year 2000 of Swiss and Western European power plants and boilers with the associated energy chains. The addressed nuclear sys- tems concern Light Water Reactors (LWR) with mix of open and closed fuel cycles. The system model 'Natural Gas' describes production, distribution, and

Roberto Dones; Thomas Heck; Mireille Faist Emmenegger; Niels Jungbluth

2005-01-01

314

Energy price indices and discount factors for life-cycle cost analysis 1997. Annual supplement to NIST handbook 135 and NBS special publication 709. (Revised)  

Microsoft Academic Search

This report is the FY 1997 edition of energy price indices and discount factors for performing life-cycle cost analyses of energy and water conservation and renewable energy projects in federal facilities. It supports the federal life-cycle costing methodology by updating the energy price projections and discount factors that are described, explained, and illustrated in NIST Handbook 135 (HB 135, Life-Cycle

1996-01-01

315

Energy price indices and discount factors for life-cycle cost analysis 1996. Annual supplement to NIST handbook 135 and NBS special publication 709. (Revised)  

Microsoft Academic Search

This is the 1996 annual edition of energy price indices and discount factors for performing life-cycle cost analyses of energy and water conservation and renewable energy projects. It supports the federal life-cycle costing methodology by updating the energy price projections and discount factors that are described, explained, and illustrated in NIST Handbook 135 (HB 135). It supports private-sector life-cycle cost

1995-01-01

316

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

317

Mechanisms of energy restriction: effects of corticosterone on cell growth, cell cycle machinery, and apoptosis.  

PubMed

The restriction of energy intake has documented beneficial effects on numerous diseases including cancer, yet the mechanism(s) that accounts for these effects is unknown. Recently, we showed that the inhibitory activity against mammary carcinogenesis mediated by energy restriction (ER) is accompanied by an increase in the secretion of adrenal cortical steroids. However, ER caused a concomitant reduction in circulating levels of insulin-like growth factor-1, which also may be involved in inhibiting carcinogenesis. To determine what cellular and molecular effects may be because of corticosterone per se, detailed mechanistic studies were performed in vitro using a mouse mammary hyperplastic cell line (TM10). The following questions were addressed: (a) is corticosterone-mediated growth inhibition accounted for by disruption of cell cycle machinery; (b) is growth inhibition accompanied by the induction of apoptosis; and (c) is growth inhibition reversible? At doses of corticosterone (50-200 micro M for 24-72 h) that resulted in inhibition (up to 76%; P < 0.001) of growth, a dose- and time-dependent G(1) arrest in cell cycle progression was observed. In the studies analyzing cell cycle regulatory molecules, corticosterone treatment of cells resulted in a strong induction (up to approximately 10-fold over control; P < 0.01) of KIP1/P27 together with a decrease (up to 98%; P < 0.01) in cyclin-dependent kinase 4 (CDK4) and cyclin D1 protein levels. Cells treated with corticosterone also showed an increased binding (up to 2.6-fold over control; P < 0.01) of KIP1/P27 with CDK4, together with a strong decrease (up to 89%; P < 0.01) in the kinase activity of the CDK4-cyclin D1 complex. Treatment of cells with KIP1/P27 antisense oligonucleotides reversed the growth inhibitory effects of corticosterone. Treatment of cells with RU 486, a glucocorticoid receptor blocker, reversed the effects of corticosterone on cell growth and KIP/P27 protein levels suggesting the involvement of the glucocorticoid receptor in accounting for these effects. Additional studies assessing the biological fate of cells after corticosterone treatment showed that corticosterone exerted reversible growth inhibitory effects with limited apoptotic cell death. Together, these findings show a reversible cytostatic effect of corticosterone via perturbations in cell cycle regulators causing a G(1) arrest in the absence of increased levels of apoptosis. These data provide evidence for a role of corticosterone on some but not all of the cellular activities associated with ER-mediated inhibition of mammary carcinogenesis. PMID:12234997

Jiang, Weiqin; Zhu, Zongjian; Bhatia, Neehar; Agarwal, Rajesh; Thompson, Henry J

2002-09-15

318

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

319

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

SciTech Connect

The US 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 uderway 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 in this paper for 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. 7 refs., 4 figs., 2 tabs.

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

1989-01-01

320

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.

321

Identifying energy and carbon footprint optimization potentials of a sludge treatment line with Life Cycle Assessment.  

PubMed

This study exemplifies the use of Life Cycle Assessment (LCA) as a tool to quantify the environmental impacts of processes for wastewater treatment. In a case study, the sludge treatment line of a large wastewater treatment plant (WWTP) is analysed in terms of cumulative energy demand and the emission of greenhouse gases (carbon footprint). Sludge treatment consists of anaerobic digestion, dewatering, drying, and disposal of stabilized sludge in mono- or co-incineration in power plants or cement kilns. All relevant forms of energy demand (electricity, heat, chemicals, fossil fuels, transport) and greenhouse gas emissions (fossil CO(2), CH(4), N(2)O) are accounted in the assessment, including the treatment of return liquor from dewatering in the WWTP. Results show that the existing process is positive in energy balance (-162 MJ/PE(COD) * a) and carbon footprint (-11.6 kg CO(2)-eq/PE(COD) * a) by supplying secondary products such as electricity from biogas production or mono-incineration and substituting fossil fuels in co-incineration. However, disposal routes for stabilized sludge differ considerably in their energy and greenhouse gas profiles. In total, LCA proves to be a suitable tool to support future investment decisions with information of environmental relevance on the impact of wastewater treatment, but also urban water systems in general. PMID:23128622

Remy, C; Lesjean, B; Waschnewski, J

2013-01-01

322

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

NASA Astrophysics Data System (ADS)

Since the United States began a programme 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, Michael; Wu, May; Huo, Hong

2007-04-01

323

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

324

Ketogenesis in isolated rat liver mitochondria I. Relationships with the citric acid cycle and with the mitochondrial energy state  

Microsoft Academic Search

1. A method is described to calculate the distribution of acetyl-CoA over the citric acid cycle and ketogenesis during the oxidation of fatty acids in the presence of added malate.\\u000a\\u000a2. Increasing concentrations of added Krebs cycle intermediates lower the rate of ketogenesis both in the low-energy state (State 3; in the presence of glucose and hexokinase (EC 2.7.1.1)) and

M. Lopes-Cardozo; S. G. van den Bergh

1972-01-01

325

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

326

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

327

Renewable Energy from Willow Biomass Crops: Life Cycle Energy, Environmental and Economic Performance  

Microsoft Academic Search

Short-rotation woody crops (SRWC) along with other woody biomass feedstocks will play a significant role in a more secure and sustainable energy future for the United States and around the world. In temperate regions, shrub willows are being developed as a SRWC because of their potential for high biomass production in short time periods, ease of vegetative propagation, broad genetic

Gregory A. Keoleian; Timothy A. Volk

2005-01-01

328

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...

329

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

2013-09-14

330

Thermal-cycling tests for a compressed-air energy storage recuperator: Final report  

SciTech Connect

The purpose of this investigation was to validate empirically an analytical procedure used to assess the fatigue life of compressed-air energy storage (CAES) recuperators when subjected to thermal cycling. A previous EPRI research project investigated the problem of thermal fatigue in CAES recuperators using finite-element analysis. This empirical investigation was performed to validate the results of that investigation. A scale model of a particular CAES recupertor tube-to-tubesheet joint was constructed. This model was subjected to thermal cycles representative of those expected in a CAES recuperator. Strains and temperature were measured and correlated with the strains and temperatures predicted by finite-element analysis. Visual and dye-penetrant inspections were performed on a periodic basis to detect the formation of fatigue cracks. In adition, periodic leak checks were performed to detect the propagation of crack growth through the depth of the tube-to-tubesheet-joint weld. Several cracks were detected, two of which penetrated the full weld depth before the desired useful life of CAES would be expended. Stress concentrations were calculated which correlate with those used in the finite-element analysis. Recommendations are given for the design of a tube-to-tubesheet joint for a CAES recuperator which should provide the desired fatigue life. 6 refs., 57 figs., 4 tabs.

Montgomery, M.E.

1987-12-01

331

Study of the ultrahigh-energy primary-cosmic-ray composition with the MACRO experiment  

SciTech Connect

We present the analysis of multiple-muon events collected with one supermodule (1013 h live time) and two supermodules (1195 h live time) of the MACRO detector at Gran Sasso, Italy. Multimuon rates are shown to be sensitive to primary-cosmic-ray energies between {similar to}50 TeV and several thousand TeV. Experimental data are compared with the expected rates from two composition models: a light (i.e., proton-rich) and a heavy (i.e., Fe-rich) composition. The predictions are based on a Monte Carlo simulation of the hadronic interactions of cosmic-ray nuclei, followed by a detailed tracking of the muons through the rock and the experimental apparatus. The results show good sensitivity of the MACRO detector to primary composition. The data exhibit a preference towards the light composition model.

Ahlen, S.; Ambrosio, M.; Antolini, R.; Auriemma, G.; Baldini, A.; Bam, B.B.; Barbarino, G.C.; Barish, B.C.; Battistoni, G.; Bellotti, R.; Bemporad, C.; Bernardini, P.; Bilokon, H.; Bisi, V.; Bloise, C.; Bussino, S.; Cafagna, F.; Calicchio, M.; Campana, P.; Campana, D.; Carboni, M.; Cecchini, S.; Cei, F.; Chiarella, V.; Chiera, C.; Cobis, A.; Cormack, R.; Corona, A.; Coutu, S.; DeCataldo, G.; DeMarzo, C.; De Vincenzi, M.; Di Credico, A.; Diehl, E.; Erriquez, O.; Favuzzi, C.; Ficenec, D.; Forti, C.; Foti, L.; Fusco, P.; Giacomelli, G.; Giannini, G.; Giglietto, N.; Giubellino, P.; Grassi, M.; Green, P.; Grillo, A.; Guarino, F.; Gustavino, C.; Habig, A.; Heinz, R.; Hong, J.T.; Iarocci, E.; Katsavounidis, E.; Kearns, E.; Klein, S.; Kyriazopoulou, S.; Lamanna, E.; Lane, C.; Lee, C.; Levin, D.; Lipari, P.; Liu, G.; Liu, R.; Longo, M.J.; Ludlam, G.; Mancarella, G.; Mandrioli, G.; Margiotta-Neri, A.; Marin, A.; Marini, A.; Martello, D.; Martellotti, G.; Marzari Chiesa, A.; Masera, M.; Matteuzzi; (MACRO Collaboration)

1992-08-01

332

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

333

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

Microsoft Academic Search

EXECUTIVE SUMMARY ;\\u000a\\u0009The 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

Janet M Twomey

2010-01-01

334

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.

335

Material and energy recovery in integrated waste management systems: A life-cycle costing approach  

SciTech Connect

Highlights: > The study aims at assessing economic performance of alternative scenarios of MSW. > The approach is the life-cycle costing (LCC). > Waste technologies must be considered as complementary into an integrated strategy. - Abstract: A critical assumption of studies assessing comparatively waste management options concerns the constant average cost for selective collection regardless the source separation level (SSL) reached, and the neglect of the mass constraint. The present study compares alternative waste management scenarios through the development of a desktop model that tries to remove the above assumption. Several alternative scenarios based on different combinations of energy and materials recovery are applied to two imaginary areas modelled in order to represent a typical Northern Italian setting. External costs and benefits implied by scenarios are also considered. Scenarios are compared on the base of the full cost for treating the total waste generated in the area. The model investigates the factors that influence the relative convenience of alternative scenarios.

Massarutto, Antonio [University of Udine, Udine (Italy); IEFE, Bocconi University, Milan (Italy); Carli, Alessandro de, E-mail: alessandro.decarli@unibocconi.it [IEFE, Bocconi University, Milan (Italy); Graffi, Matteo [University of Udine, Udine (Italy); IEFE, Bocconi University, Milan (Italy)

2011-09-15

336

Life Cycle Assessment of a Wastewater Treatment Plant Focused on Material and Energy Flows  

NASA Astrophysics Data System (ADS)

Life cycle assessment (LCA) was applied to analyze a food-processing wastewater treatment plant and investigate the economic and environmental effects of the plant. With the long-term operational data of this plant, an inventory of relative inputs, e.g., flow rate, chemical oxygen demand (COD), and suspended solids, etc., and outputs of the plant, e.g., effluent COD and suspended solids, methane production, etc., was compiled. The potential environmental effects associated with those inputs and outputs were evaluated, and the results of the inventory analysis and impact assessment phases of the plant were interpreted. One feature of this study was the assessment of the treatment plant based on both energy and material flows. Another feature was the establishment of an assessment model with an integration of plant operating parameters, system recognition and grey relation. The analytical results are helpful for the design and operation of wastewater treatment plants.

Wu, Jian-Guang; Meng, Xiang-Yu; Liu, Xiao-Meng; Liu, Xian-Wei; Zheng, Zhi-Xia; Xu, De-Qian; Sheng, Guo-Ping; Yu, Han-Qing

2010-10-01

337

Open cycle ocean thermal energy conversion steam control and bypass system  

SciTech Connect

A description is given of an open cycle ocean thermal energy conversion system comprising: an axial flow turbine having a rotor whose axis of rotation is vertical and radially inner and outer casing structures which therebetween define an annular motive fluid path, said rotor including an annular array of radial blades extending across said fluid path; a condenser in fluid communication with said annular motive fluid flow path for condensing the motive fluid expanded through the turbine blades; a flash evaporator disposed about the turbine's axis of rotation, said evaporator having a generally toroidal-shaped casing, the interior of said casing being in fluid communication with said condenser both through and in bypassing relationship with said turbine blades; first means for regulating motive fluid flow from said evaporator to said condenser through said turbine blades; and second means for regulating bypass motive fluid flow from said evaporator to said condenser.

Jennings, S.; Wittig, J.

1980-07-01

338

Thermal analysis in a solar pumped laser for Mg energy cycle  

NASA Astrophysics Data System (ADS)

Thermal analysis of a high-power cw solar-pumped laser under development as a magnesium energy cycle driver has been conducted experimentally and analytically. The laser system is equipped with a Fresnel lens and a cone-shaped secondary mirror chamber (SMC). The SMC realizes a hybrid-pumping scheme combining axial- and side-pumping configurations to enhance solar light absorption to a rod-shaped laser medium. A non-uniform temperature profile was obtained during experiments due to combination of volumetric heating and surface cooling, which leads to a nonuniform variation of index of refraction in the laser medium. The thermal lensing and thermal stress-induced birefringence are analyzed.

Bagheri, Behgol; Uchidat, Shgeaki

2012-10-01

339

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

340

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.

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

2012-01-01

341

Investigation of design space for freeze-drying: use of modeling for primary drying segment of a freeze-drying cycle.  

PubMed

In this work, we explore the idea of using mathematical models to build design space for the primary drying portion of freeze-drying process. We start by defining design space for freeze-drying, followed by defining critical quality attributes and critical process parameters. Then using mathematical model, we build an insilico design space. Input parameters to the model (heat transfer coefficient and mass transfer resistance) were obtained from separate experimental runs. Two lyophilization runs are conducted to verify the model predictions. This confirmation of the model predictions with experimental results added to the confidence in the insilico design space. This simple step-by-step approach allowed us to minimize the number of experimental runs (preliminary runs to calculate heat transfer coefficient and mass transfer resistance plus two additional experimental runs to verify model predictions) required to define the design space. The established design space can then be used to understand the influence of critical process parameters on the critical quality attributes for all future cycles. PMID:21710335

Koganti, Venkat Rao; Shalaev, Evgenyi Y; Berry, Mark R; Osterberg, Thomas; Youssef, Maickel; Hiebert, David N; Kanka, Frank A; Nolan, Martin; Barrett, Rosemary; Scalzo, Gioval; Fitzpatrick, Gillian; Fitzgibbon, Niall; Luthra, Sumit; Zhang, Liling

2011-06-28

342

Measurement of Changes in High-Energy Phosphates in the Cardiac Cycle by Using Gated 31P Nuclear Magnetic Resonance  

NASA Astrophysics Data System (ADS)

Levels of the high-energy phosphate-containing compounds, ATP and creatine phosphate, and of inorganic phosphate (Pi) were measured as a function of position in the cardiac cycle. Measurements were made on isolated, perfused, working rat hearts through the use of gated 31P nuclear magnetic resonance spectroscopy. Levels of ATP and creatine phosphate were found to vary during the cardiac cycle and were maximal at minimal aortic pressure and minimal at maximal aortic pressure. Pi varied inversely with the high-energy phosphates.

Fossel, Eric T.; Morgan, Howard E.; Ingwall, Joanne S.

1980-06-01

343

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

344

78 FR 43870 - Hydrogen Energy California's Integrated Gasification Combined Cycle Project; Preliminary Staff...  

Federal Register 2010, 2011, 2012, 2013

...combined cycle power block; manufacture...capacity, the plant is expected to...The combined power block consists...of low-carbon electricity. This combined-cycle...of its multiple production capabilities, the plant is referred...

2013-07-22

345

SYNTHESIS OF A MODEL SYSTEM FOR THE PRIMARY ENERGY CONVERSION REACTIONS IN PHOTOSYNTHESIS*  

PubMed Central

A model system is constructed which, like the photosynthetic apparatus of green plants, can convert light to chemical free energy through pigment-sensitized photooxidation of water. The system has two light-harvesting subunits connected electrically in series. Each subunit is made of a multimolecular layer of Zn(II)-tetraphenylporphyrin deposited on a clean aluminum surface and immersed in an aqueous mixture of potassium ferri- and ferrocyanide. Upon illumination by amber light, charge transfer takes place across more than 70 molecular layers of the pigment with a photoelectromotive force of 1.1 to 1.3 volts per subunit. With NADP as the electron acceptor and NADP-reductase as a mediator, the system can photooxidize water to oxygen gas. With these model experiments as a guide, a molecular mechanism for the primary energy conversion reactions in photosynthesis is formulated that offers a unified interpretation of most of the relevant observations reported in the literature.

Wang, Jui H.

1969-01-01

346

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

347

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

348

Total energy cycle assessment of electric and conventional vehicles: an energy and environmental analysis. Volume 4: peer review comments on 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 IV includes copies of all the external peer review comments on the report distributed for review in July 1997.

NONE

1998-01-01

349

Modeling and analysis of energy conservation scheme based on duty cycling in wireless ad hoc sensor network.  

PubMed

In sensor network, energy conservation is one of the most critical issues since sensor nodes should perform a sensing task for a long time (e.g., lasting a few years) but the battery of them cannot be replaced in most practical situations. For this purpose, numerous energy conservation schemes have been proposed and duty cycling scheme is considered the most suitable power conservation technique, where sensor nodes alternate between states having different levels of power consumption. In order to analyze the energy consumption of energy conservation scheme based on duty cycling, it is essential to obtain the probability of each state. In this paper, we analytically derive steady state probability of sensor node states, i.e., sleep, listen, and active states, based on traffic characteristics and timer values, i.e., sleep timer, listen timer, and active timer. The effect of traffic characteristics and timer values on the steady state probability and energy consumption is analyzed in detail. Our work can provide sensor network operators guideline for selecting appropriate timer values for efficient energy conservation. The analytical methodology developed in this paper can be extended to other energy conservation schemes based on duty cycling with different sensor node states, without much difficulty. PMID:22219676

Chung, Yun Won; Hwang, Ho Young

2010-06-03

350

Modeling and Analysis of Energy Conservation Scheme Based on Duty Cycling in Wireless Ad Hoc Sensor Network  

PubMed Central

In sensor network, energy conservation is one of the most critical issues since sensor nodes should perform a sensing task for a long time (e.g., lasting a few years) but the battery of them cannot be replaced in most practical situations. For this purpose, numerous energy conservation schemes have been proposed and duty cycling scheme is considered the most suitable power conservation technique, where sensor nodes alternate between states having different levels of power consumption. In order to analyze the energy consumption of energy conservation scheme based on duty cycling, it is essential to obtain the probability of each state. In this paper, we analytically derive steady state probability of sensor node states, i.e., sleep, listen, and active states, based on traffic characteristics and timer values, i.e., sleep timer, listen timer, and active timer. The effect of traffic characteristics and timer values on the steady state probability and energy consumption is analyzed in detail. Our work can provide sensor network operators guideline for selecting appropriate timer values for efficient energy conservation. The analytical methodology developed in this paper can be extended to other energy conservation schemes based on duty cycling with different sensor node states, without much difficulty.

Chung, Yun Won; Hwang, Ho Young

2010-01-01

351

Primary charge separation and energy transfer in the photosystem I reaction center of higher plants  

SciTech Connect

Using low intensity femtosecond duration laser pulses at 708 nm, we have observed absorption transients associated with electron transfer through the primary electron acceptor A{sub 0} in the photosystem I (PSI) reaction center from spinach under nonreducing conditions. At this wavelength the electron donor P{sub 700} is excited directly, although some antenna chlorophylls are also excited. Using a nanosecond duration preflash of 690 nm to oxidize P{sub 700}, and then measuring the absorption transients from the antenna alone, it is possible by subtraction to isolate the absorption transients arising from electron transfer. We discuss this method critically. Th spectrum of A{sub 0}{sup -}-A{sub 0} does not appear promptly but takes nearly 3 ps to reach maximum intensity and resembles those spectra previously obtained from higher plants, with a maximum bleaching at 685{+-}2 nm and a shoulder in the region 670-675 nm. The decay time of the primary radical pair P{sub 700}{sup +}A{sub 0}{sup -} is calculated as 20 ps. Analysis of absorption transients indicates that the intrinsic rate constant forming the primary radical pair P{sub 700}{sup +}A{sub 0}{sup -} cannot be measured directly because energy migration in the antenna is fast and quenching is approaching `trap limited` behavior. With use of a detailed model of the antenna energy migration based on the X-ray structure, the intrinsic rate constant for electron transfer is estimated as k{sub 1} nearly equals 0.7 ps{sup -1}. 81 refs., 15 figs., 1 tab.

White, N.T.H.; Beddard, G.S.; Thorne J.R.G.; Feehan, T.M.; Keyes, T.E. [Univ. of Manchester (United Kingdom); Heathcote, P. [Queen Mary and Westfield College, London (United Kingdom)

1996-07-18

352

Hydrogen cycling by enzymes: electrocatalysis and implications for future energy technology.  

PubMed

Hydrogenases provide an inspiration for future energy technologies. The active sites of these microbial enzymes contain Fe or Ni and Fe coordinated by CO and CN ligands: yet they have activities for hydrogen cycling that compare with Pt catalysts. Is there a future for enzymes in technological H2 cycling? There are obviously going to be disadvantages, perhaps overwhelming, as enzymes are notoriously fragile; yet what are the positive aspects and can we learn any chemistry that might be applied to produce the electrolytic and fuel cell catalysts of the future? We have developed a suite of novel electrochemical experiments to probe the chemistry of hydrogenases. The reactions are controlled and monitored at the surface of a small electrode, and characteristic catalytic properties are discernible from tiny amounts of sample material, so this approach can be used to search the microbial world for the best catalysts. Although electrochemistry does not provide structural information directly, it does give a "road map" by which to navigate the pathways and conditions that lead to particular states of the enzymes. This has prompted many interdisciplinary collaborations with other scientists who have provided microbiological, spectroscopic and structural contexts for this work. This article describes how these electrochemical experiments are set up, the data are analysed, and the results interpreted. We have determined mechanisms of catalysis, electron transfer, activation and inactivation, and defined important properties such as O2 tolerance and CO resistance in physical terms. Using an O2-tolerant hydrogenase, we have demonstrated a "proof of concept" miniature fuel cell that will run on a mixed H2/O2 feed in aqueous solution. PMID:16234917

Vincent, Kylie A; Cracknell, James A; Parkin, Alison; Armstrong, Fraser A

2005-09-21

353

The chemical composition of primary cosmic rays in the energy range ~1015 eV from muon energy spectrum with the Okayama muon telescope  

NASA Astrophysics Data System (ADS)

The chemical composition of primary cosmic rays in the energy range ~1015 eV are going to be examined from muon energy spectra using the AIRES simulation program. The muon energy spectra observed by the compact extensive air shower array and the solid iron magnet spectrometer are compared with simulation result.

Matsumoto, H.; Iyono, A.; Masuda, M.; et al.

354

Energy Spectra, Composition, and Other Properties of Ground-Level Events During Solar Cycle 23  

NASA Astrophysics Data System (ADS)

We report spacecraft measurements of the energy spectra of solar protons and other solar energetic particle properties during the 16 Ground Level Events (GLEs) of Solar Cycle 23. The measurements were made by eight instruments on the ACE, GOES, SAMPEX, and STEREO spacecraft and extend from ˜0.1 to ˜500-700 MeV. All of the proton spectra exhibit spectral breaks at energies ranging from ˜2 to ˜46 MeV and all are well fit by a double power-law shape. A comparison of GLE events with a larger sample of other solar energetic particle (SEP) events shows that the typical spectral indices are harder in GLE events, with a mean slope of -3.18 at >40 MeV/nuc. In the energy range 45 to 80 MeV/nucleon about ˜50 % of GLE events have properties in common with impulsive 3He-rich SEP events, including enrichments in Ne/O, Fe/O, 22Ne/20Ne, and elevated mean charge states of Fe. These 3He-rich events contribute to the seed population accelerated by CME-driven shocks. An analysis is presented of whether highly-ionized Fe ions observed in five events could be due to electron stripping during shock acceleration in the low corona. Making use of stripping calculations by others and a coronal density model, we can account for events with mean Fe charge states of < Q Fe>?+20 if the acceleration starts at ˜1.24-1.6 solar radii, consistent with recent comparisons of CME trajectories and type-II radio bursts. In addition, we suggest that gradual stripping of remnant ions from earlier large SEP events may also contribute a highly-ionized suprathermal seed population. We also discuss how observed SEP spectral slopes relate to the energetics of particle acceleration in GLE and other large SEP events.

Mewaldt, R. A.; Looper, M. D.; Cohen, C. M. S.; Haggerty, D. K.; Labrador, A. W.; Leske, R. A.; Mason, G. M.; Mazur, J. E.; von Rosenvinge, T. T.

2012-10-01

355

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

356

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

357

Ocean thermal energy conversion gas desorption studies. Volume 1. Design of experiments. [Open-cycle power systems  

Microsoft Academic Search

Seawater deaeration is a process affecting almost all proposed Ocean Thermal Energy Conversion (OTEC) open-cycle power systems. If the noncondensable dissolved air is not removed from a power system, it will accumulate in thecondenser, reduce the effectiveness of condensation, and result in deterioration of system performance. A gas desorption study is being conducted at Oak Ridge National Laboratory (ORNL) with

A. Golshani; F. C. Chen

1980-01-01

358

Transportation versus perishability in life cycle energy consumption: A case study of the temperature-controlled food product supply chain  

Microsoft Academic Search

Moving goods from the point of production to markets involves energy use and can have adverse environmental effects. But from the supply chain management perspective, the control of the supply chain, with short time cycles between production and sale to customer, can benefit the environment by closely tailoring production to consumption, and by minimizing the amount of “perishability” in the

Francis Vanek; Yao Sun

2008-01-01

359

Evaluation of Surface Water and Energy Cycles in the Met Office Global NWP Model Using CEOP Data  

Microsoft Academic Search

Components of the surface water and energy balance are evaluated in the Met Office global Numerical Weather Prediction (NWP) 00-36 hour forecasts using (i) GEWEX Continental Scale Experiment (CSE) reference site data provided by the Coordinated Enhanced Observing Period (CEOP) project and (ii) other earth observing datasets from satellites and in-situ measurements. The global hydrological cycle in the model is

Sean F. MILTON; P. EARNSHAW

2007-01-01

360

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

361

Life cycle greenhouse gas emissions, fossil fuel demand and solar energy conversion efficiency in European bioethanol production for automotive purposes  

Microsoft Academic Search

Crop derived biofuels such as (bio)ethanol are increasingly applied for automotive purposes. They have, however, a relatively low efficiency in converting solar energy into automotive power. The outcome of life cycle studies concerning ethanol as to fossil fuel inputs and greenhouse gas emissions associated with such inputs depend strongly on the assumptions made regarding e.g. allocation, inclusion of upstream processes

L. Reijnders; M. A. J. Huijbregts

2007-01-01

362

Quantifying the mean, variability, and trends in the water and energy cycles across NEESPI through modeling and observations  

Microsoft Academic Search

Determining the mean, variability and trends of the terrestrial water and energy cycles across northern Eurasia is challenging, in part because in situ observations are spatially sparse with varying temporal coverage. Remote sensing shows promise in providing large scale measurements, but in general it does not have a long historical record and is subject to its own limitations and uncertainties.

T. J. Troy; E. F. Wood; J. Sheffield

2008-01-01

363

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

364

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

365

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

366

Heat loss as a percentage of fuel’s energy in air standard Otto and Diesel cycles  

Microsoft Academic Search

The heat addition process for an air standard Otto (or Diesel) cycle has been widely described in the literature e.g. as subtraction from the fuel’s chemical energy of an arbitrary heat loss parameter times the average temperature of heat the adding period. The heat leakage parameter and the fuel’s energy depend on each other. Their valid ranges given in the

Osman A. Ozsoysal

2006-01-01

367

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.

368

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

369

Emulsion experiment for study on energy spectra of protons and nuclei of primary cosmic radiation in the energy range greater than 10 TeV per particle  

NASA Astrophysics Data System (ADS)

Development of the emulsion chamber method to study the energy spectrum of protons and nuclei of primary cosmic radiation is described; the results obtained in long-term exposure of emulsion chambers in the stratospere are presented.

Varkovitskaya, A. Ya.; Zamchalova, E. A.; Zatsepin, V. I.; Sazhina, G. P.; Sokolskaya, N. V.

370

Analysis of a Helium Brayton Power Cycle for a Direct-Drive Inertial Fusion Energy Power Reactor  

NASA Astrophysics Data System (ADS)

Presented is a thermodynamic model analysis and optimization of a helium Brayton power cycle for direct-drive inertial fusion energy (IFE) reactor. Preliminary reactor design goals include production of 2GW of thermal power and an estimated 700MW of electricity using a tertiary indirect helium Brayton cycle. A thermodynamic analysis of the proposed helium Brayton cycle is performed using baseline technology specifications and generalized thermodynamic assumptions. Analytic equations are developed using first and second law analysis. The model constraints are the turbine inlet temperature and pressure set by the reactor temperature of ˜700^oC and current turbine specifications of 7MPa, respectively. Optimization of this model is then performed using iterative numerical programming for key variables. Previous analysis shows a 51% cycle efficiency using current technology; best estimates of near-term technology increase the cycle efficiency to 64%. Results will be presented. R. Schleicher, A. R. Raffray, C. P. Wong, ``An Assessment of the Brayton Cycle for High Performance Power Plant,'' Fusion Technology, 39 (2), 823-827, March 2001.

Wagner, Scott; Gentile, Charles; Parsells, Robert; Priniski, Craig

2008-11-01

371

The INCA project for satellite studies of primary cosmic rays in the energy range 1015 - 1016eV  

Microsoft Academic Search

The basic goal of the project is determination of the nuclear composition and the energy spectrum of primary cosmic radiation within the energy range 1015 - 1016eV (the knee region). To solve this problem, the authors propose, using a detector of a new type, the so called Ionization Neutron Calorimeter (INCA) combined with the Particle Charge Detector (PCD) installed on

A. P. Chubenko; G. A. Bazilevskaya; A. N. Kvashnin; G. I. Merzon; N. M. Nesterova; V. P. Pavlyuchenko; V. S. Puchkov; V. A. Ryabov; V. I. Rubtsov; Yu. I. Stozhkov; S. A. Slavatinskij; V. S. Starkov; V. A. Tsarev; G. B. Zhdanov; G. I. Dement'ev; R. A. Mukhamedshin; N. M. Sobolevskij; G. T. Zatsepin; V. V. Ammosov; T. Saito; H. Sasaki

1999-01-01

372

Effect of Ash in Coal on the Performance of Coal Fired Thermal Power Plants. Part I: Primary Energy Effects  

Microsoft Academic Search

This article reports the effect of ash content in raw coal on the energy performance of coal fired thermal power plants of capacity range 30–500 MW. The focus is on primary energy effects—combustion, heat transfer, and flow hydrodynamics. The effects of variation of ash in coal from 6% (taken as standard) up to 75% on component performance are studied and

M. Siddhartha Bhatt

2006-01-01

373

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

374

Performance analysis of an air-standard Miller cycle with considerations of heat loss as a percentage of fuel's energy, friction and variable specific heats of working fluid  

Microsoft Academic Search

This study is aimed at examining the effects of heat loss characterized by a percentage of fuel's energy, friction and variable specific heats of working fluid on the performance of an air-standard Miller cycle under the restriction of maximum cycle temperature. A more realistic and precise relationship between the fuel's chemical energy and the heat leakage that is constituted on

Jiann-Chang Lin; Shuhn-Shyurng Hou

2008-01-01

375

Effects of heat loss as percentage of fuel’s energy, friction and variable specific heats of working fluid on performance of air standard Otto cycle  

Microsoft Academic Search

The objective of this study is to analyze the effects of heat loss characterized by a percentage of the fuel’s energy, friction and variable specific heats of working fluid on the performance of an air standard Otto cycle with a restriction of maximum cycle temperature. A more realistic and precise relationship between the fuel’s chemical energy and the heat leakage

Jiann-Chang Lin; Shuhn-Shyurng Hou

2008-01-01

376

Seawater test results of open-cycle ocean thermal energy conversion (OC-OTEC) components  

SciTech Connect

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 m[sup 3]/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. (National Renewable Energy Lab., Golden, CO (United States)); Panchal, C.B. (Argonne National Lab., IL (United States))

1994-01-01

377

Experiments on oxygen desorption from surface warm seawater under open-cycle ocean thermal energy conversion  

SciTech Connect

This paper presents the results of scoping deaeration experiments conducted with warm surface seawater under open-cycle ocean thermal energy conversion (OC-OTEC) conditions. Concentrations of dissolved oxygen in seawater at three locations (in the supply water, water leaving the predeaerator, and discharge water from an evaporator) were measured and used to estimate oxygen desorption levels. The results suggest that 7 percent to 60 percent of the dissolved oxygen in the supply water was desorbed from seawater in the predeaerator for pressures ranging from 35 to 9 kPa. Bubble injection in the upcomer increased the oxygen desorption rate by 20 percent to 60 percent. The data also indicated that at typical OC-OTEC evaporator pressures, when flash evaporation in the evaporator occurred, 75 percent to 95 percent of the dissolved oxygen was desorbed overall from the warm seawater. The results were used to find the impact of a single-stage predeaeration scheme on the power to remove noncondensable gases in an OC-OTEC plant.

Pesaran, A.A. (Solar Energy Research Inst., Golden, CO (United States))

1992-11-01

378

Seawater test results of open-cycle ocean thermal energy conversion (OC-OTEC) components  

SciTech Connect

Key components of open-cycle ocean thermal energy conversion (OC-OTEC) 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 1.25 MW (thermal), requiring a warm seawater flow of about 0.1 m{sub 3}/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 demonstrated for the first time using OC-OTEC technology.

Zangrando, F.; Bharathan, D.; Link, H. (Solar Energy Research Inst., Golden, CO (USA)); Panchal, C.B. (Argonne National Lab., IL (USA))

1990-01-01

379

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

380

Introduction to combined cycles  

Microsoft Academic Search

Ideas and concepts underlying the technology of combined cycles including the scientific principles involved and the reasons these cycles are in fashion at the present time, are presented. A cycle is a steady flow process for conversion of heat energy into work, in which a working medium passes through a range of states, returning to its original state. Cycles for

M. J. Moore

1993-01-01

381

AB 1007 Full Fuel Cycle Analysis (FFCA) Peer Review  

SciTech Connect

LLNL is a participant of California's Advanced Energy Pathways (AEP) team funded by DOE (NETL). At the AEP technical review meeting on November 9, 2006. The AB 1007 FFCA team (Appendix A) requested LLNL participate in a peer review of the FFCA reports. The primary contact at the CEC was McKinley Addy. The following reports/presentations were received by LLNL: (1) Full Fuel Cycle Energy and Emissions Assumptions dated September 2006, TIAX; (2) Full Fuel cycle Assessment-Well to Tank Energy Inputs, Emissions, and Water Impacts dated December 2006, TIAX; and (3) Full Fuel Cycle Analysis Assessment dated October 12, 2006, TIAX.

Rice, D; Armstrong, D; Campbell, C; Lamont, A; Gallegos, G; Stewart, J; Upadhye, R

2007-01-19

382

Algal photosynthesis as the primary driver for a sustainable development in energy, feed, and food production.  

PubMed

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 CO? 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 CO? 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; Hellingwerf, Klaas J

2010-07-20

383

Research and development efforts at the Department of Energy (DOE) supporting integrated gasification combined cycle (IGCC) demonstrations  

SciTech Connect

One of the most energy efficient systems meeting the needs of industrial and utility groups in the US in increasing numbers is the gas-turbine-based combined cycle, due large in part to the availability of relatively inexpensive natural gas. One advantage of this type of combined-cycle system is its flexibility to be readily converted into a coal-based system by converting the coal under pressure into a gaseous form that can readily be cleaned of nearly all sulfur and most nitrogen compounds originally present in the coal. Integrating and optimizing aspects of the gas-turbine and steam-turbine power generation cycle with the coal gasification process give overall efficiencies with coal that are not dramatically lower than those available with natural gas. Efforts at DOE are focused on simplifying aspects of the integration that lower the overall capital and operating costs of the IGCC without compromising environmental performance.

Rath, L.K.; Bedick, R.C.

1992-01-01

384

Improved cycling stability of silicon thin film electrodes through patterning for high energy density lithium batteries  

Microsoft Academic Search

The mechanical degradation of electrodes caused by lithiation and delithiation is one of the main factors responsible for the short cycle life of lithium-based batteries employing high capacity electrodes. In this report, we introduced a simple patterning approach to improve the cycling stability of silicon electrode, which is considered as the next generation negative electrode due to its high Coulombic

X. Xiao; P. Liu; M. W. Verbrugge; H. Haftbaradaran; H. Gao

2011-01-01

385

Iron-dependent changes in cellular energy metabolism: influence on citric acid cycle and oxidative phosphorylation  

Microsoft Academic Search

Iron modulates the expression of the critical citric acid cycle enzyme aconitase via a translational mechanism involving iron regulatory proteins. Thus, the present study was undertaken to investigate the consequences of iron perturbation on citric acid cycle activity, oxidative phosphorylation and mitochondrial respiration in the human cell line K-562. In agreement with previous data iron increases the activity of mitochondrial

Horst Oexle; Erich Gnaiger; Günter Weiss

1999-01-01

386

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

387

Sensitivity analysis of an Ocean Carbon Cycle Model in the North Atlantic: an investigation of parameters affecting the air-sea CO2 flux, primary production and export of detritus  

Microsoft Academic Search

The sensitivity of the biological parameters in a nutrient-phytoplankton-zooplankton-detritus (NPZD) model in the calculation of the air-sea CO2 flux, primary production and detrital export is analysed. The NPZD model is the Hadley Centre Ocean Carbon Cycle model (HadOCC) from the UK Met Office, used in the Hadley Centre Coupled Model 3 (HadCM3) and FAst Met Office and Universities Simulator (FAMOUS)

V. Scott; H. Kettle; C. J. Merchant

2010-01-01

388

Net primary production and nutrient cycling in an apple orchard–annual crop system in the Loess Plateau, China: a comparison of Qinguan apple, Fuji apple, corn and millet production subsystems  

Microsoft Academic Search

In this study, we investigated net primary production (NPP) and nutrient cycling in an apple orchard–annual crop system located\\u000a in the Hill and Gully Region of the Loess Plateau, which included four production subsystems: Qinguan apple, Fuji apple, corn\\u000a and millet. The results showed that NPP of corn (Zea\\u000a mays L.) was two to three times greater than for millet

Wu Faqi; Liu Haibin; Sun Baosheng; Wang Jian; William J. Gale

2008-01-01

389

ELECTRICITY SCENARIOS FOR THE BALTIC STATES AND MARGINAL ENERGY TECHNOLOGY IN LIFE CYCLE ASSESSMENTS - A CASE STUDY OF ENERGY PRODUCTION FROM MUNICIPAL WASTE INCINERATION  

Microsoft Academic Search

In the present study two different sets of assumptions for future power pro- duction scenarios, one based on conventional technologies and another assuming a more sustainable energy oriented electricity production, for the Baltic States are analysed to identify the possible marginal electricity sources which could be used in consequential Life Cycle Assessment (LCA) studies in these countries. The environmental impacts

H. MOORA; V LAHTVEE

2009-01-01

390

Design and Application of an Advanced Industrial Waste-to-Energy Rankine-Cycle Power System : Final Report.  

SciTech Connect

The advanced, industrial, waste-to-energy, Rankine-cycle system was designed to convert wood processing residue, a renewable resource, to electrical energy and steam. The system consists of an advanced tube-in-bed, fluidized-bed boiler, designed to burn a wide variety of wood wastes, combined with a high efficiency, radial-inflow, back pressure steam turbine. The turbine drives a generator to supply electrical power for the mill while the exhaust steam is utilized for process requirements such as driers. This report consists of the following tasks: investigation of environmental effects and their mitigation; and development of an investment figure of merit, based on a comprehensive life-cycle costing analysis, by which to quantify the techno-economic merit of Rankine-cycle system; identification of potential demonstration sites based on the criteria developed in Task 1; preliminary design of the complete advanced Rankine-cycle system, including boiler, turbine, and principal ancillary items, and development of economic scenarios for the system, based on the economic analysis methods developed earlier; development of a site screening matrix for 25 potential installation sites, based on the procedures developed in Task 2 and augmented by extensive discussions with mill operators; and determination of the specific set of terms and conditions on which at least one potential investor would be prepared to invest.

Mechanical Technology Incorporated.

1986-10-01

391

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

392

High energy muon spectra at zenith angles 0° and 89° derived from the single indexed primary nucleon spectrum.  

NASA Astrophysics Data System (ADS)

The muon energy spectra at zenith angles 0° and 89° have been estimated from the single indexed primary cosmic ray nucleon spectrum of the form N(E)dE = 2.75 E-2.37dE (cm2 s sr GeV)-1 based on latest primary flux measurements surveyed by Swordy (1993) using the Z-factor for hadron-hadron collisions from the FNAL data after Brenner et al (1982). The calculated total differential muon energy spectrum from the decay of non-prompt and prompt mesons has been found comparable with the earlier experimental results available from direct magnetic spectrograph and indirect range spectrograph measurements.

Battacharyya, D. P.; Mitra, M.; Pal, P.

1997-04-01

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

Life-cycle assessment of energy use and greenhouse gas emissions of soybean-derived biodiesel and renewable fuels.  

PubMed

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. PMID:19245012

Huo, Hong; Wang, Michael; Bloyd, Cary; Putsche, Vicky

2009-02-01

395

University of Minnesota aquifer thermal energy storage (ATES) project report on the third long-term cycle  

Microsoft Academic Search

The University of Minnesota aquifer thermal energy storage (ATES) system has been operated as a field test facility (FTF) since 1982. The objectives were to design, construct, and operate the facility to study the feasibility of high-temperature ATES in a confined aquifer. Four short-term and two long-term cycles were previously conducted, which provided a greatly increased understanding of the efficiency

M. C. Hoyer; J. P. Hallgren; M. H. Uebel; G. N. Delin; S. J. Eisenreich; R. L. Sterling

1994-01-01

396

Ghrelin neutralization during fasting-refeeding cycle impairs the recuperation of body weight and alters hepatic energy metabolism  

Microsoft Academic Search

Ghrelin, a hormone whose levels increase during food deprivation, plays a pivotal role in the regulation of food intake, energy metabolism and storage, as well as in insulin sensitivity. Here, we investigated the effects of acyl-ghrelin neutralization with the acyl-ghrelin-binding compound NOX-B11(2) during the fasting-refeeding cycle. Our data demonstrate that ghrelin neutralization with NOX-B11(2) impairs recuperation of lost body weight

Susana Sangiao-Alvarellos; Steffen Helmling; María J. Vázquez; Sven Klussmann; Fernando Cordido

2011-01-01

397

Hydrogen\\/methanol production by sulfur–iodine thermochemical cycle powered by combined solar\\/fossil energy  

Microsoft Academic Search

Hydrogen production from water using the sulfur–iodine (S–I) thermochemical cycle, powered by combined solar and fossil heat sources, has been investigated. This combined energy supply was conceived in order to operate the chemical process continuously: a solar concentrator plant with a large-scale heat storage supplies thermal load for services at medium temperatures (550?C), while a fossil fuel furnace provides heat

A. Giaconia; R. Grena; M. Lanchi; R. Liberatore; P. Tarquini

2007-01-01

398

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

399

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

400

CO 2 capture efficiency and energy requirement analysis of power plant using modified calcium-based sorbent looping cycle  

Microsoft Academic Search

This paper examines the average carbonation conversion, CO2 capture efficiency and energy requirement for post-combustion CO2 capture system during the modified calcium-based sorbent looping cycle. The limestone modified with acetic acid solution, i.e. calcium acetate is taken as an example of the modified calcium-based sorbents. The modified limestone exhibits much higher average carbonation conversion than the natural sorbent under the

Yingjie Li; Changsui Zhao; Huichao Chen; Qiangqiang Ren; Lunbo Duan

2011-01-01

401

Environmental Assessmental, Geothermal Energy, Heber Geothermal Binary-Cycle Demonstration Project: Imperial County, California.  

National Technical Information Service (NTIS)

The proposed design, construction, and operation of a commercial-scale (45 MWe net) binary-cycle geothermal demonstration power plant are described using the liquid-dominated geothermal resource at Heber, Imperial County, California. The following are inc...

1980-01-01

402

78 FR 23312 - Uranium Enrichment Fuel Cycle Inspection Reports Regarding Louisiana Energy Services, National...  

Federal Register 2010, 2011, 2012, 2013

...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

403

Life cycle environmental and economic analyses of a hydrogen station with wind energy  

Microsoft Academic Search

This study aimed to identify the environmental and economic aspects of the wind-hydrogen system using life cycle assessment (LCA) and life cycle costing (LCC) methodologies. The target H2 pathways are the H2 pathway of water electrolysis (WE) with wind power (WE[Wind]) and the H2 pathway of WE by Korean electricity mix (WE[KEM]). Conventional fuels (gasoline and diesel) are also included

Ji-Yong Lee; Sanghyuk An; Kyounghoon Cha; Tak Hur

2010-01-01

404

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

405

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

2013-07-01

406

A new sustainer with primary sided integrated of DC\\/DC converter and energy recovery circuit for AC-PDP  

Microsoft Academic Search

A new Sustainer with Primary sided Integration of DC\\/DC converter and Energy Recovery circuit (SPIDER) is proposed. The proposed circuit operates as a DC\\/DC converter during address period and energy recovery circuit during sustain period. Therefore, the conventional three electronic circuits composed of the power supply, X-driver, and Y-driver can be reduced to one circuit. As a result, it has

Jae-Sung Park; Yong-Saeng Shin; Sung-Soo Hong; Sang-Kyoo Han; Dong-Sung Oh; Chung-Wook Roh

2011-01-01

407

Construction of Direction Selectivity through Local Energy Computations in Primary Visual Cortex  

PubMed Central

Despite detailed knowledge about the anatomy and physiology of neurons in primary visual cortex (V1), the large numbers of inputs onto a given V1 neuron make it difficult to relate them to the neuron’s functional properties. For example, models of direction selectivity (DS), such as the Energy Model, can successfully describe the computation of phase-invariant DS at a conceptual level, while leaving it unclear how such computations are implemented by cortical circuits. Here, we use statistical modeling to derive a description of DS computation for both simple and complex cells, based on physiologically plausible operations on their inputs. We present a new method that infers the selectivity of a neuron’s inputs using extracellular recordings in macaque in the context of random bar stimuli and natural movies in cat. Our results suggest that DS is initially constructed in V1 simple cells through summation and thresholding of non-DS inputs with appropriate spatiotemporal relationships. However, this de novo construction of DS is rare, and a majority of DS simple cells, and all complex cells, appear to receive both excitatory and suppressive inputs that are already DS. For complex cells, these numerous DS inputs typically span a fraction of their overall receptive fields and have similar spatiotemporal tuning but different phase and spatial positions, suggesting an elaboration to the Energy Model that incorporates spatially localized computation. Furthermore, we demonstrate how these computations might be constructed from biologically realizable components, and describe a statistical model consistent with the feed-forward framework suggested by Hubel and Wiesel.

Lochmann, Timm; Blanche, Timothy J.; Butts, Daniel A.

2013-01-01

408

Carrier-envelope phase stability of hollow fibers used for high-energy few-cycle pulse generation.  

PubMed

We investigated the carrier-envelope phase (CEP) stability of hollow-fiber compression for high-energy few-cycle pulse generation. Saturation of the output pulse energy is observed at 0.6 mJ for a 260 ?m inner-diameter, 1 m long fiber, statically filled with neon. The pressure is adjusted to achieve output spectra supporting sub-4-fs pulses. The maximum output pulse energy can be increased to 0.8 mJ by either differential pumping (DP) or circularly polarized input pulses. We observe the onset of an ionization-induced CEP instability, which saturates beyond input pulse energies of 1.25 mJ. There is no significant difference in the CEP stability with DP compared to static-fill. PMID:24081088

Okell, William A; Witting, Tobias; Fabris, Davide; Austin, Dane; Bocoum, Maïmouna; Frank, Felix; Ricci, Aurélien; Jullien, Aurélie; Walke, Daniel; Marangos, Jonathan P; Lopez-Martens, Rodrigo; Tisch, John W G

2013-10-01

409

The influence of the rotational energy of a flywheel on the load pulse sum during pedalling on a cycle ergometer.  

PubMed

Employing seven male subjects, the influence of four different ergometer flywheels with the moments of inertia at the crankshaft (J') = 5.5, 10.5, 16.5, and 19.5 kg.m2 on 6-min load pulse sum (LPS), the heart rate integrated over 6-min was investigated. The J' was demonstrated to influence LPS at each of the corresponding rotational energies of the flywheels (75, 144, 226 and 276 J at 50 rev.min-1) in the four work-load steps (50, 100, 150 and 200 W). Between the values J' = 5.5 kg.m2 and 10.5 kg.m2 the LPS decreases, to rise again in the range J' = 10.5 kg.m2-19.5 kg.m2. For equal work-loads the minimum LPS was reached at a J' of 10.5 kg.m2. For the workloads of 100, 150 and 200 W it was possible to show statistically significant differences. The moment of inertia of ergometer flywheels J has a smoothing effect on the fluctuations of the rotational speed which are unavoidable during work on a cycle ergometer. The flywheel stores the leg forces acting on the pedals as rotational energy and opposes any rotational acceleration. If the J used is too small, equalization of the fluctuations of the rotational speed remains unsatisfactory. Flywheels with larger J require larger torques at the crankshaft for acceleration. For the most effective delivery of work to a cycle ergometer, an optimal rotational energy of the flywheel was found. For equal physical work, smaller or larger rotational energies require a larger expenditure of biological energy. A J' = 11 +/- 2 kg.m2 was incorporated into the draft for the German standard DIN 13,405 -- cycle-type ergometers. PMID:2737187

Voigt, B; von Kiparski, R

1989-01-01

410

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

2011-01-28

411

Thermal-economic analysis of organic Rankine combined cycle cogeneration. ITT Energy management report TR-82-3  

SciTech Connect

This study presents an evaluation of Organic Rankine Cycles (ORC) as combined with topping cycles incorporating gas turbines or diesel engines, and with subsequent waste heat utilization. The potential benefit of the proposed organic-Rankine-combined-cycle cogeneration of useful heat and electricity is more flexibility in meeting demands for the two products, by varying the mode of operation of the system. A thermal-economic analysis is developed and illustrated with cost and performance data for commercially available equipment, and with general economic parameters reflecting current regulations and market conditions. The performance of the ORC and of the entire combined cycle is described. Equations are presented for evaluating the various thermodynamic and economic parameters, and the resultant cash flows. Criteria are developed in order to assess whether or not the addition of an ORC to a cogeneration system without ORC is viable based on rate of return on incremental investment. Examples are given to illustrate how the method may be applied, namely to serve proposed commercial energy facilities for the North Loop Project and for Illinois Center, in Chicago. While results indicate that the proposed system is potentially viable, it is not viable under conditions prevailing in Chicago for the selected case studies.

Porter, R.W.

1982-12-01

412

Impact of food availability on energy storage and defense related hemocyte parameters of the Pacific oyster Crassostrea gigas during an experimental reproductive cycle  

Microsoft Academic Search

The aim of this study was to test the effect of food quantity on energy storage and defense capacities of oysters during a reproductive cycle. One-year-old Crassostrea gigas oysters were fed two different dietary rations (4% and 12% of oyster dry weight in algal dry weight per day) in controlled experimental conditions over an annual cycle. Oyster dry weights, carbohydrate

Maryse Delaporte; Philippe Soudant; Christophe Lambert; Jeanne Moal; Stéphane Pouvreaua; Jean-François Samaina

2006-01-01

413

Composition of primary cosmic rays at energies ~1015 eV from data on high-energy muons in extensive air showers  

NASA Astrophysics Data System (ADS)

A critical analysis of experimental data on high-energy muons in air showers is carried out to derive information about the composition of primary cosmic rays near the bend in the energy spectrum at ~1015 eV. A set of Monte Carlo simulated air showers from different elemental species have been used to study expectations for three different experiments: the Tien Shan study of muons with energy above 5 GeV at an altitude of 690 g/cm2, the Moscow State University experiment for muons with energy above 10 GeV at sea level, and the Kolar-gold-field experiment for muons with energy above 220 GeV at 930 g/cm2. The results show that when showers are grouped according to shower size the sensitivity of the total number of high-energy muons to primary composition is greatly reduced. In fact, it is found that the data cannot discriminate between models which assume energy-independent low-energy composition and those which assume energy spectra which steepen above some value of rigidity cutoff around 1014 eV/nucleon. In order to make a compositionsensitive measurement of the high-energy muon component it is necessary to make these measurements at fixed energy rather than at fixed shower size.

Yodh, G. B.; Goodman, J. A.; Tonwar, S. C.; Ellsworth, R. W.

1984-03-01

414

Formulating energy policies related to fossil fuel use: Critical uncertainties in the global carbon cycle  

SciTech Connect

The global carbon cycle is the dynamic interaction among the earth's carbon sources and sinks. Four reservoirs can be identified, including the atmosphere, terrestrial biosphere, oceans, and sediments. Atmospheric CO{sub 2} concentration is determined by characteristics of carbon fluxes among major reservoirs of the global carbon cycle. The objective of this paper is to document the knowns, and unknowns and uncertainties associated with key questions that if answered will increase the understanding of the portion of past, present, and future atmospheric CO{sub 2} attributable to fossil fuel burning. Documented atmospheric increases in CO{sub 2} levels are thought to result primarily from fossil fuel use and, perhaps, deforestation. However, the observed atmospheric CO{sub 2} increase is less than expected from current understanding of the global carbon cycle because of poorly understood interactions among the major carbon reservoirs. 87 refs.

Post, W.M.; Dale, V.H.; DeAngelis, D.L.; Mann, L.K.; Mulholland, P.J.; O'Neill, R.V.; Peng, T.-H.; Farrell, M.P.

1990-01-01

415

Global Water Cycle.  

National Technical Information Service (NTIS)

This research is the MSFC component of a joint MSFC/Pennsylvania State University Eos Interdisciplinary Investigation on the global water cycle extension across the earth sciences. The primary long-term objective of this investigation is to determine the ...

F. Robertson S. J. Goodman J. R. Christy D. E. Fitzjarrald S. Chou

1993-01-01

416

Life cycle energy use and greenhouse gas emission analysis for a water resource recovery facility in India.  

PubMed

This paper quantifies life cycle energy use and greenhouse gas (GHG) emissions associated with water resource recovery facilities (WRRFs) in India versus water quality improvements achieved from infrastructure investments. A first such analysis is conducted using operating data for a WRRF, which employs upflow anaerobic sludge blanket (UASB) reactors and oxidation. On-site operations energy use, process GHG emissions, and embodied energy in infrastructure were quantified. The analysis showed energy use and GHG emissions of 0.2 watt-hours (Wh) and 0.3 gram carbon dioxide (CO2) equivalents per liter (gCO2e/L) wastewater treated, and 1.3 Wh and 2.1 gCO2e/gBOD removed, achieving 81% biochemical oxygen demand (BOD) and 999% fecal coliform removal annually. Process emissions of WRRFs contributed 44% of life cycle GHG emissions, similar in magnitude to those from electricity (46%), whereas infrastructure contributed 10%. Average WRRF-associated GHG emissions (0.9gCO2e/L) were lower than those expected if untreated wastewater was released to the river. Investments made by WRRFs in developing world cities improve water quality and may mitigate overall GHG emissions. PMID:23944144

Miller-Robbie, Leslie; Ramaswami, Anu; Kumar, Prasanna

2013-07-01

417

Energy and exergy analysis of a micro-compressed air energy storage and air cycle heating and cooling system  

Microsoft Academic Search

Energy storage systems are becoming more important for load leveling, especially for widespread use of intermittent renewable energy. Compressed air energy storage (CAES) is a promising method for energy storage, but large scale CAES is dependent on suitable underground geology. Micro-CAES with man-made air vessels is a more adaptable solution for distributed future power networks. In this paper, energy and

Y. M. Kim; D. Favrat

2010-01-01

418

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

419

A quantitative evaluation of closed-cycle ocean thermal energy conversion (OTEC) technology in central station applications  

NASA Astrophysics Data System (ADS)

An evaluation of a closed cycle Ocean Thermal Energy Conversion (OTEC) system for delivery of electric power to the United States is presented. Performance and costs of complete commercial OTEC systems are analyzed at the system level using inputs from component analyses and thermal resource data in the Gulf of Mexico. Such sites could feed the Gulf Coast from the west coast of Florida to the New Orleans area. By exploiting the temperature difference between warm surface waters and cold water from the depths to operate a thermodynamic cycle to generate electricity, OTEC acts as a heat engine that taps the surface waters of tropical and subtropical oceans as a heat source and the cold water originating in the polar regions as a heat sink. Results of the engineering analysis indicate that the system and platform appear to be within the state-of-the-art.

Gritton, E. C.; Pei, R. Y.; Aroesty, J.; Balaban, M. M.; Gazley, C.; Hess, R. W.; Krase, W. H.

1980-05-01

420

Life-cycle cost analysis of energy efficiency design options for residential furnaces and boilers  

Microsoft Academic Search

In 2001, the US Department of Energy (DOE) initiated a rulemaking process to consider whether to amend the existing energy efficiency standards for furnaces and boilers. A key factor in DOE's consideration of new standards is the economic impacts on consumers of possible revisions to energy-efficiency standards. Determining cost-effectiveness requires an appropriate comparison of the additional first cost of energy

James Lutz; Alex Lekov; Peter Chan; Camilla Dunham Whitehead; Steve Meyers; James McMahon

2006-01-01

421

Electricity from Geothermal Energy with the Kalina Cycle An Exergy Approach  

Microsoft Academic Search

The geothermal energy that is stored in the earth is so vast that could supply all the energy needed by humanity. The difficulty in tapping this energy lies in its diffusivity. The geothermal energy in regions close to volcanoes is close to the surface and easy to use economically. In this paper a vapor dominated system will be examined. The

Christopher J. Koroneos; Dimitrios C. Rovas

2007-01-01

422

Multi-parametric study of the effect of materials substitution on life cycle energy use and waste generation of passenger car structures  

Microsoft Academic Search

Aluminium and fibre reinforced plastics have been put forward as alternatives for steel to reduce passenger car weight and save energy during use. Often-reported drawbacks are increased energy for production and reduced recyclability, and hence, increased waste generation. This study considers the merits of the alternatives by making a multi-parametric comparison of the life cycle energy use and waste generation

E. Tempelman

2011-01-01

423

On the ability of some cyclic plasticity models to predict the evolution of stored energy in a type 304L stainless steel submitted to high cycle fatigue  

Microsoft Academic Search

Fatigue analyses of materials are generally based on a so-called stabilized cycle, on which plastic strain amplitude, plastic energy, maximum shear stress and so on are determined. The part of plastic energy which is dissipated in heat cannot be used to accumulate damage and it should be worthwhile extracting only the part of plastic energy which is stored in material

Ludovic Vincent

2008-01-01

424

University of Minnesota Aquifer Thermal Energy Storage (ATES) project report on the first long-term cycle  

NASA Astrophysics Data System (ADS)

The technical feasibility of high-temperature (greater than 100 C) aquifer thermal energy storage (IOTAS) in a deep, confined aquifer was tested in a series of experimental cycles at the University of Minnesota's St. Paul field test facility (FTF). This report describes the additions to the FTF for the long-term cycles and the details of the first long-term cycle (LT1) that was conducted from November 1984 through May 1985. Heat recovery; operational experience; and thermal, chemical, hydrologic, and geologic aspects of LT1 are reported. The permits for long-term cycles required the addition of a monitoring well 30.5 m from the storage well for monitoring near the edge of the thermally affected area and allowed the addition of a cation-exchange water softener to enable continuous operation during the injection phase. Approximately 62 percent of the 9.47 GWh of energy added to the 9.21 x 10(exp 4) cu m of ground water stored in the aquifer LT1 was recovered. Ion-exchange water softening of the heated and stored ground water prevented scaling in the system heat exchangers and the storage well and changed the major-ion chemistry of the stored water. Temperatures at the storage horizons in site monitoring wells reached as high as 108 C during the injection phase of LT1. Following heat recovery, temperatures were less than 30 C at the same locations. Less permeable horizons underwent slow temperature changes. No thermal or chemical effects were observed at the remote monitoring site.

Walton, M.

1991-10-01

425

University of Minnesota Aquifer Thermal Energy Storage (ATES) project report on the first long-term cycle  

SciTech Connect

The technical feasibility of high-temperature (>100{degrees}C) aquifer thermal energy storage (IOTAS) in a deep, confined aquifer was tested in a series of experimental cycles at the University of Minnesota`s St. Paul field test facility (FTF). This report describes the additions to the FTF for the long-term cycles and the details of the first long-term cycle (LT1) that was conducted from November 1984 through May 1985. Heat recovery; operational experience; and thermal, chemical, hydrologic, and geologic aspects of LT1 are reported. The permits for long-term cycles required the addition of a monitoring well 30.5 m from the storage well for monitoring near the edge of the thermally affected area and allowed the addition of a cation-exchange water softener to enable continuous operation during the injection phase. Approximately 62% of the 9.47 GWh of energy added to the 9.21 {times} 10{sup 4} m{sup 3} of ground water stored in the aquifer LT1 was recovered. Ion-exchange water softening of the heated and stored ground water prevented scaling in the system heat exchangers and the storage well and changed the major-ion chemistry of the stored water. Temperatures at the storage horizons in site monitoring wells reached as high as 108{degrees}C during the injection phase of LT1. Following heat recovery, temperatures were <30{degrees}C at the same locations. Less permeable horizons underwent slow temperature changes. No thermal or chemical effects were observed at the remote monitoring site. 25 refs.

Walton, M. [Minnesota Geological Survey, St. Paul, MN (United States)

1991-10-01

426

University of Minnesota Aquifer Thermal Energy Storage (ATES) project report on the first long-term cycle  

SciTech Connect

The technical feasibility of high-temperature (>100{degrees}C) aquifer thermal energy storage (IOTAS) in a deep, confined aquifer was tested in a series of experimental cycles at the University of Minnesota's St. Paul field test facility (FTF). This report describes the additions to the FTF for the long-term cycles and the details of the first long-term cycle (LT1) that was conducted from November 1984 through May 1985. Heat recovery; operational experience; and thermal, chemical, hydrologic, and geologic aspects of LT1 are reported. The permits for long-term cycles required the addition of a monitoring well 30.5 m from the storage well for monitoring near the edge of the thermally affected area and allowed the addition of a cation-exchange water softener to enable continuous operation during the injection phase. Approximately 62% of the 9.47 GWh of energy added to the 9.21 {times} 10{sup 4} m{sup 3} of ground water stored in the aquifer LT1 was recovered. Ion-exchange water softening of the heated and stored ground water prevented scaling in the system heat exchangers and the storage well and changed the major-ion chemistry of the stored water. Temperatures at the storage horizons in site monitoring wells reached as high as 108{degrees}C during the injection phase of LT1. Following heat recovery, temperatures were <30{degrees}C at the same locations. Less permeable horizons underwent slow temperature changes. No thermal or chemical effects were observed at the remote monitoring site. 25 refs.

Walton, M. (Minnesota Geological Survey, St. Paul, MN (United States))

1991-10-01

427

Comparative Analysis of the Life-Cycle Costs of Residential Energy Supply Technologies  

Microsoft Academic Search

Long-term experiences from the residential use of micro- cogeneration systems are not yet available. The evaluation of the economic viability of these systems therefore calls for feasibility studies and the development of computational models that accommodate uncertainties. In this paper, we review uncertainties related to the life- cycle costs of residential heating systems and present a comparative analysis, in order

Kari Alanne; Arto Saari; Ahti Salo

2007-01-01

428

Time-budgeting by starlings Sturnus vulgaris : Time minimizing, energy maximizing and the annual cycle organization  

Microsoft Academic Search

In seasonal environments, time often constrains the timing and duration of processes in annual cycles of animals both on the diel and annual basis. Therefore, the allocation of time e.g. to foraging, resting and breeding behaviours should be true adaptations to the particular circumstances the animals experience.

Per Lundberg

1985-01-01

429

Fuel cycle strategies for the sustainable development of nuclear energy: The role of accelerator driven systems  

Microsoft Academic Search

The paper summarizes fuel cycle strategies which can call for the development of accelerator driven systems (ADS) and shows how an ADS-based transmutation strategy can be envisaged in a regional context. Finally, a path towards the demonstration of the ADS concept will be proposed, which accounts for the need of developing a consistent strategy of dedicated fuel development and validation

Massimo Salvatores

2006-01-01

430

Cycling performance of the iron-chromium redox energy storage system  

NASA Astrophysics Data System (ADS)

Extended charge-discharge cycling of this electrochemical storage system at 65 C was performed on 14.5 sq cm single cells and a four cell, 867 sq cm bipolar stack. Both the anolyte and catholyte reactant fluids contained 1 molar concentrations of iron and chromium chlorides in hydrochloric acid and were separated by a low-selectivity, cation-exchange membrane. The effect of cycling on the chromium electrode and the cation-exchange membrane was determined. Bismuth and bismuth-lead catalyzed chromium electrodes and a radiation-grafted polyethylene membrane were evaluated by cycling between 5 and 85 percent state-of-charge at 80 mA/sq cm and by periodic charge-discharge polarization measurements to 140 mA/sq cm. Gradual performance losses were observed during cycling but were recoverable by completely discharging the system. Good scale-up to the 867 sq cm stack was achieved. The only difference appeared to be an unexplained resistive-type loss which resulted in a 75 percent W-hr efficiency (at 80 mA/sq cm versus 81 percent for the 14.5 sq cm cell). A new rebalance cell was developed to maintain reactant ionic balance. The cell successfully reduced ferric ions in the iron reactant stream to ferrous ions while chloride ions were oxidized to chlorine gas.

Gahn, R. F.; Hagedorn, N. H.; Johnson, J. A.

1985-01-01

431

Cycling performance of the iron-chromium redox energy storage system  

NASA Astrophysics Data System (ADS)

Extended charge-discharge cycling of this electrochemical storage system at 65 C was performed on 14.5 sq cm single cells and a four cell, 867 sq cm bipolar stack. Both the anolyte and catholyte reactant fluids contained 1 molar concentrations of iron and chromium chlorides in hydrochloric acid and were separated by a low-selectivity, cation-exchange membrane. The effect of cycling on the chromium electrode and the cation-exchange membrane was determined. Bismuth and bismuth-lead catalyzed chromium electrodes and a radiation-grafted polyethylene membrane were evaluated by cycling between 5 and 85 percent state-of-charge at 80 mA/sq cm and by periodic charge-discharge polarization measurements to 140 mA/sq cm. Gradual performance losses were observed during cycling but were recoverable by completely discharging the system. Good scale-up to the 867 sq cm stack was achieved. The only difference appeared to be an unexplained resistive-type loss which resulted in a 75 percent W-hr efficiency (at 80 mA/sq cm versus 81 percent for the 14.5 sq cm cell). A new rebalance cell was developed to maintain reactant ionic balance. The cell successfully reduced ferric ions in the iron reactant stream to ferrous ions while chloride ions were oxidized to chlorine gas.

Gahn, R. F.; Hagedorn, N. H.; Johnson, J. A.

1985-12-01

432

Life cycle assessment of energy from solid waste—part 1: general methodology and results  

Microsoft Academic Search

The overall goal of the present study is to evaluate different strategies for treatment of solid waste in Sweden based on a life cycle perspective. Important goals are to identify advantages and disadvantages of different methods for treatment of solid waste, and to identify critical factors in the systems, including the background systems, which may significantly influence the results. Included

Göran Finnveden; Jessica Johansson; Per Lind; Åsa Moberg

2005-01-01

433

Users' Requirements for Environmental Effects From Innovative Nuclear Energy Systems and Their Fuel Cycles  

Microsoft Academic Search

The objective of the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) is to support the safe, sustainable, economic and proliferation resistant use of nuclear technology to meet the needs of the 21. century. The first part of the project focusses on the development of an understanding of the requirements of possible users of innovative concepts for reactors

M. Carreter; M. Gray; E. Falck; A. Bonne; M. Bell

2002-01-01

434

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

Microsoft Academic Search

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.

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

2008-01-01

435

77 FR 65729 - Uranium Enrichment Fuel Cycle Facility Inspection Reports Regarding Louisiana Energy Services LLC...  

Federal Register 2010, 2011, 2012, 2013

...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 National...Regulatory Commission Brian W. Smith, Chief, Uranium Enrichment Branch, Division of Fuel...

2012-10-30

436

Energy 3: Fossil Fuel Use and its Consequences - The Carbon Cycle  

NSDL National Science Digital Library

This video goes through the carbon cycle and describes how using fossil fuels threatens the foundation of the aquatic global food chain. This video is part of the Sustainability Learning Suites, made possible in part by a grant from the National Science Foundation. See 'Learn more about this resource' for Learning Objectives and Activities.

Vanasupa, Linda

437

Energy from waste\\/gas turbine hybrid combined cycles and their potential for GHG emissions reduction  

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 life cycle basis shows that about 33% of the total CO2 emissions from incineration of the waste are of fossil origin, which implies that MSW is 67% carbon-neutral. The waste constitutes a \\

K. Qiu; A. C. S. Hayden; P. Sears

2006-01-01

438

Comprehensive Analysis of Coronal Mass Ejection Mass and Energy Properties Over a Full Solar Cycle.  

National Technical Information Service (NTIS)

The LASCO coronagraphs, in continuous operation since 1995, have observed the evolution of the solar corona and coronal mass ejections (CMEs) over a full solar cycle with high quality images and regular cadence. This is the first time that such a dataset ...

A. Vourlidas E. Esfandiari R. A. Howard S. Patsourakos S. Yashiro

2010-01-01