These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Life cycle primary energy implication of retrofitting a wood-framed apartment building to passive house standard  

Microsoft Academic Search

Here we analyze the life cycle primary energy implication of retrofitting a four-storey wood-frame apartment building to the energy use of a passive house. The initial building has an annual final energy use of 110kWh\\/m2 for space and tap water heating. We model improved thermal envelope insulation, ventilation heat recovery, and efficient hot water taps. We follow the building life

Ambrose Dodoo; Leif Gustavsson; Roger Sathre

2010-01-01

2

Cell cycle perturbations and genotoxic effects in human primary fibroblasts induced by low-energy protons and X/gamma-rays.  

PubMed

The effect of graded doses of high-linear energy transfer (LET) low-energy protons to induce cycle perturbations and genotoxic damage was investigated in normal human fibroblasts. Furthermore, such effects were compared with those produced by low-LET radiations. HFFF2, human primary fibroblasts were exposed to either protons (LET = 28.5 keV/microm) or X/gamma-rays, and endpoints related to cell cycle kinetics and DNA damage analysed. Following both type of irradiations, unsynchronized cells suffered an inhibition to entry into S-phase for doses of 1-4 Gy and remained arrested in the G(1)-phase for several days. The levels of induction of regulator proteins, such as TP53 and CDKN1A showed a clear LET-dependence. DSB induction and repair as measured by scoring for gamma-H2AX foci indicated that protons, with respect to X-rays, yielded a lower number of DSBs per Gy, which showed a slower kinetics of disappearance. Such result was in agreement with the extent of MN induction in binucleated cells after X-irradiation. No significant differences between the two types of radiations were observed with the clonogenic assay, resulting anyway the slope of gamma-ray curve higher than that the proton one. In conclusion, in normal human primary fibroblasts cell cycle arrest at the G(1)/S transition can be triggered shortly after irradiation and maintained for several hours post-irradiation of both protons and X-rays. DNA damage produced by protons appears less amenable to be repaired and could be transformed in cytogenetic damage in the form of MN. PMID:19755805

Antoccia, Antonio; Sgura, Antonella; Berardinelli, Francesco; Cavinato, Maria; Cherubini, Roberto; Gerardi, Silvia; Tanzarella, Caterina

2009-09-01

3

Annual cycle energy system  

Microsoft Academic Search

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 an ice-water bin. Solar panels are used to replenish the stored energy. The bin must be large enough to

Minturn

1979-01-01

4

Annual cycle energy system  

Microsoft Academic Search

The annual cycle energy system (ACES) program which incorporates in a practical system the outstanding energy conservation potential that exists when the unidirectional heat pump and the interseasonal storage of energy are combined to provide heating, cooling, and domestic hot water to buildings is described. Information on the system, its applicability to different geographic areas, and the methodology for designing

R. E. Minturn

1981-01-01

5

The annual cycle energy system  

Microsoft Academic Search

The annual cycle energy system (ACES) obtains heat by freezing water during the heating season. A one-direction heat pump is used to deliver the heat to the building. The ice is used to provide air conditioning during the summer. The cycle is repeated each year and the only major energy expenses are related to the cost of operating the heat

H. C. Fischer

1975-01-01

6

Other primary energy resources  

Microsoft Academic Search

Approaches for the utilization of geothermal energy are discussed along with possibilities to employ tidal energy, wind energy, the energy of waves on the surface of the sea, and the energy of glaciers. Attention is also given to installations which use the temperature difference between the water at the surface of the sea and the water at a greater depth

A. Voss; V. Bundschuh; M. Meliss; D. Oesterwind

1974-01-01

7

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

8

Interfacing primary heat sources and cycles for thermochemical hydrogen production  

SciTech Connect

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

Bowman, M.G.

1980-01-01

9

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

10

The Energy Strategy Cycle  

E-print Network

Effective long-range energy planning begins with a reflective analysis that encompasses the complexity of today's energy reality and sets a course for activity to achieve long-range continuing advancement. This strategy approach involves...

Korich, R. D.

1983-01-01

11

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

12

Annual Cycle Energy System (ACES)  

Microsoft Academic Search

A single family residence near Knoxville, Tennessee, is being used to demonstrate the energy conserving features of the annual cycle energy system (ACES), an integrated heating and cooling system that utilizes a unidirectional heat pump and low temperature thermal storage. A second house, the control house, is being used to compare the performance of the ACES with that of an

A. S. Holman; L. A. Abbatiello

1980-01-01

13

Day/Night Cycle: Mental Models of Primary School Children  

ERIC Educational Resources Information Center

The study investigated the mental models of primary school children related to the day/night cycle. Semi-structure interviews were conducted with 40 fourth-grade and 40 sixth-grade children. Qualitative and quantitative analysis of the data indicated that the majority of the children were classified as having geocentric models. The results also…

Chiras, Andreas

2008-01-01

14

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

15

Open cycle traveling wave thermoacoustics: Energy fluxes and thermodynamics  

Microsoft Academic Search

In an open cycle traveling wave thermoacoustic engine, hot gas steadily flows into the hot side of the regenerator, replacing the hot heat exchanger as the primary energy source for the engine. In such an engine, interactions between the acoustic, convective, conductive and thermoacoustic energy fluxes facilitate conversion of the input thermal energy into acoustic energy. This study describes the

Nathan T. Weiland; Ben T. Zinn

2004-01-01

16

Modified annual cycle energy system  

Microsoft Academic Search

The Annual Cycle Energy System (ACES) is a system that provides domestic hot water heating, space heating and space cooling for buildings. This system uses a unidirectional heat pump and a large water\\/ice storage tank to make ice during the heating season that is used to cool the building during the summer. The ACES uses a concrete water\\/ice storage tank

Sills

1984-01-01

17

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

18

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.

19

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

20

Free Energy and Internal Combustion Engine Cycles  

E-print Network

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

William D. Harris

2012-01-11

21

Free Energy and Internal Combustion Engine Cycles  

E-print Network

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

Harris, William D

2012-01-01

22

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). Confusing these fundamentally different concepts is a documented roadblock to future understanding of energy in the context of science. 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.

2013-04-03

23

Control of annual cycle energy systems  

Microsoft Academic Search

A technique is described for controlling and monitoring the Annual Cycle Energy System (ACES) for the seasonal storage of thermal energy. The system combines a computer-based choice of air or stored heat sources, ice inventory control, solar heat, and daytime use of nighttime refrigeration to provide the lowest annual cost for heating and cooling. Several operating modes are described that

Spethmann

1979-01-01

24

Annual cycle energy system concept and application  

Microsoft Academic Search

The Annual Cycle Energy System (ACES), under development at ERDA's Oak Ridge National Laboratory, promises to provide space heating, air conditioning, and water heating at a significantly lower expenditure of energy than conventional space conditioning and water heating systems. The ACES embodies heat pumping, thermal storage and, where climate dictates, solar assistance. The concept is described, along with variations in

J. C. Moyers; E. C. Hise

1977-01-01

25

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

26

Primary vacuum pumps for the fusion reactor fuel cycle  

Microsoft Academic Search

The primary vacuum system for a tokamak-type controlled thermonuclear reactor with 1-GW thermal output is analyzed. The need for recovery, purification, and recycling of deuterium--tritium (D--T) fuel to the reactor leads to the following basic requirements for vacuum pumps at the reactor exhaust: effective pumping speed approx.250 m³ s⁻¹; inlet pressure approx.0.1 Pa; outlet pressure greater than or equal to10

J. L. Hemmerich

1988-01-01

27

Annual cycle energy system: Initial investigations  

Microsoft Academic Search

Initial analytical and experimental investigations were conducted to establish data and design procedures prior to a demonstration of the Annual Cycle Energy System (ACES) in an actual building. ACES is an integrated system for supplying space heating and cooling, and domestic hot water to a building through the use of a heat pump, a thermal storage unit, and an outdoor

H. C. Fischer; J. C. Christian; E. C. Hise; A. S. Holman; A. J. Miller; W. R. Mixon; J. C. Moyers; E. A. Nephew

1976-01-01

28

Primary urban energy-management-planning methodology  

SciTech Connect

Metropolitan Dade County, Florida, developed a pragmatic, transferable methodology to assist local governments in attempts to develop and implement energy management plans. A summary of that work is presented and suggestions are provided to guide the application and refinement of a Primary Urban Energy Management Planning Methodology. The methodology provides local governments with the systematic approach for dealing with short and intermediate-term urban energy management problems while at the same time laying the groundwork for the formulation of long-term energy management activities. The five tasks of the methodology summarized are: organizing for the PEP process; performing an energy use and supply inventory; formulating energy management goals and objectives; developing strategies to achieve the energy management objectives; and monitoring and evaluation. (MCW)

None

1980-11-01

29

The Sun: Earth's Primary Energy Source  

NSDL National Science Digital Library

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

Lightle, Kimberly

2011-02-01

30

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

E-print Network

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

Farritor, Shane

31

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

32

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

E-print Network

SQUID­SIMS is a useful approach to uncover primary signals in the Archean sulfur cycle Woodward W examined drill core samples from slope and basinal environments adjacent to a major Late Archean (2-rich Archean environments--even in an Archean ocean ba- sin dominated by iron chemistry. mass independent

Fischer, Woodward

33

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

E-print Network

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

34

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

PubMed

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

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

2013-03-19

35

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

36

MICROPLASTICITY AND ENERGY DISSIPATION IN VERY HIGH CYCLE FATIGUE  

E-print Network

1 of 3 MICROPLASTICITY AND ENERGY DISSIPATION IN VERY HIGH CYCLE FATIGUE Véronique Favier, Ngoc Lam in metals and alloys in Very High Cycle Fatigue (VHCF). In contrast to conventional fatigue tests, detecting ("Microplasticity and energy dissipation in very high cycle fatigue") is an ongoing French project financially

Boyer, Edmond

37

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

Microsoft Academic Search

This report documents a computer program for designing a surface condenser that condenses low-pressure steam in an ocean thermal energy conversion (OTEC) power plant. The primary emphasis is on the open-cycle (OC) OTEC power system, although the same condenser design can be used for conventional and hybrid cycles because of their highly similar operating conditions. In an OC-OTEC system, the

C. B. Panchal; T. J. Rabas

1991-01-01

38

Total energy cycle energy use and emissions of electric vehicles.  

SciTech Connect

A total energy cycle analysis (TECA) of electric vehicles (EV) was recently completed. The EV energy cycle includes production and transport of fuels used in power plants to generate electricity, electricity generation, EV operation, and vehicle and battery manufacture. This paper summarizes the key assumptions and results of the EVTECA. The total energy requirements of EVS me estimated to be 24-35% lower than those of the conventional, gasoline-fueled vehicles they replace, while the reductions in total oil use are even greater: 55-85%. Greenhouse gases (GHG) are 24-37% lower with EVs. EVs reduce total emissions of several criteria air pollutants (VOC, CO, and NO{sub x}) but increase total emissions of others (SO{sub x}, TSP, and lead) over the total energy cycle. Regional emissions are generally reduced with EVs, except possibly SO{sub x}. The limitations of the EVTECA are discussed, and its results are compared with those of other evaluations of EVs. In general, many of the results (particularly the oil use, GHG, VOC, CO, SO{sub x}, and lead results) of the analysis are consistent with those of other evaluations.

Singh, M. K.

1999-04-29

39

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

Microsoft Academic Search

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

V. Utgikar; T. Thiesen

2006-01-01

40

Relationship between masticatory cycle morphology and unilateral crossbite in the primary dentition.  

PubMed

Occlusion is an important factor that affects chewing. Unilateral posterior crossbites (UPXBs) have been reported to be one of the most prevalent malocclusions in the primary dentition and patients with UPXBs show abnormal condylar motion on the crossbite side in the mediolateral direction during mastication. The aims of this study were to investigate the characteristics of common chewing cycles in the primary dentition in children with UPXBs, when chewing gum on the UPXB side and on the non-UPXB side, and to compare the average chewing pattern with a group of children with a normal buccal relationship. Twenty children in the primary dentition with a UPXB (6 boys, mean age 5.3 ± 1.2 years, and 14 girls, 4.8 ± 1.3 years of age; 9 with a left and 11 with a right UPXB) and 10 children with a normal occlusion were randomly selected. Chewing movements were recorded with the Sirognathograph computer analysing system (COSIG II). All children were asked to chew gum on both sides. The chewing patterns were averaged and analysed in two projection planes and compared using a Student's t-test with respect to the relationship between chewing pattern and occlusion. Significance was set at P ? 0.05. Children with a UPXB showed a difference between the chewing pattern on the UPXB and non-UPXB sides. Greater lateral deviation in the chewing cycle was observed on the working side when chewing on the non-UPXB side. The closing angle was found to be more pronounced towards the non-working side when chewing on the UPXB side and the time spent in maximal intercuspation showed reduced values when chewing on the same side. Children with a UPXB opened their mouths wider and showed greater chewing cycles in the sagittal and horizontal projection planes while chewing on the UPXB side and also in the frontal projection while chewing on both the UPXB and the non-UPXB sides in comparison with the control group, P ? 0.05. Children with a UPXB produced chewing cycles with a shorter rest position and more frequently in a reverse direction when chewing on the UPXB side in comparison with children with a normal occlusion and with the non-UPXB side. Based on the results of this study, early treatment is recommended to normalize the masticatory chewing cycle pattern to ensure normal growth and development of the orofacial system. PMID:21118909

Sever, Ecijo; Marion, Ljubo; Ovsenik, Maja

2011-12-01

41

CONTINUOUS pH AND CONDUCTIVITY MEASURING OF DISTILLED WATER IN PRIMARY CYCLE OF CZECHOSLOVAK NUCLEAR REACTOR  

Microsoft Academic Search

The development of pH and conductivity measurements of water in primary ; cycle of an experimental reactor of the Czechoslovak Academy of Sciences is ; described. The experience gained during operation, and results of measurements, ; are reported as well. (auth);

F. Vozenilek; J. Vojta

1962-01-01

42

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

43

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

44

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

45

NCESR -Energy Research Grants Cycle 6 RFP Released: June 1, 20111 Energy Research Grants  

E-print Network

NCESR - Energy Research Grants Cycle 6 RFP ­ Released: June 1, 20111 Energy Research Grants Cycle 6 (RFP) includes the following: A. 2011 Focus Areas . . . . . . . . . . . . . . . . . . . . . 2 B . . . . . . . . . . . . . . . . . . . . . . 6 #12;NCESR - Energy Research Grants Cycle 6 RFP ­ Released: June 1, 20112 A. 2011 FOCUS AREAS

Farritor, Shane

46

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

47

A regional evaluation of the annual cycle energy system  

Microsoft Academic Search

The Solar Assisted Annual Cycle Energy System (ACES) is evaluated by means of a dynamic computer simulation. The operational concept of the ACES is discussed and the methodology used in evaluating the system is presented. Annual energy consumption and associated costs are investigated for the full, minimum and cost-optimized ACES in a variety of US climates. The energy and economic

J. W. MacArthur; D. W. Finn-Carlson; K. H. Nguyen

1980-01-01

48

A regional evaluation of the annual cycle energy system  

Microsoft Academic Search

The Solar Assisted Annual Cycle Energy System (ACES) is evaluated by means of a dynamic computer simulation. The operational concept of the ACES is discussed and the methodology used in evaluating the system is presented. Annual energy consumption and associated costs are investigated for the full, minimum and cos-topimised ACES in a variety of US climates. The energy and economic

J. Ward MacArthur; Dean W. Finn-Carlson; K. H. Nguyen

1980-01-01

49

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

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

50

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

51

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

52

Determining the intensity and energy expenditure during commuter cycling  

PubMed Central

Objectives To determine the intensity and energy expenditure during commuter cycling, and to investigate whether cycling to work at a self?chosen intensity corresponds to recommendations of the Centers for Disease Control and Prevention (CDC) and American College of Sports Medicine (ACSM) for health improvement and ACSM recommendations for fitness improvement. Methods 18 healthy, untrained middle?aged people, who did not cycle to work, underwent two maximal exercise tests (MT and MT2) in order to measure their maximal heart rate and oxygen consumption (VO2). MT2 was performed 24?weeks after MT. Participants were asked to cycle at least three times a week to their workplace over a one?way minimum distance of 2?km. Data on cycling were recorded in a diary. 12?weeks after MT, a field test was conducted, where participants had to cycle to or from their workplace. The same measurements were taken as during MT as markers of exercise intensity. Metabolic equivalents (METs) and energy expenditure were calculated. Results The intensity during the field test was >75% of their maximal aerobic capacity. The mean (SD) MET value was 6.8 (1.9). The energy expenditure during the field test was 220 (115)?kcal or 540 (139)?kcal/h and 1539 (892)?kcal/week. Men consumed significantly (p<0.01) more energy per hour than women. Conclusion Commuter cycling at a self?selected intensity meets the CDC and ACSM recommendations for health improvement and the ACSM recommendations for improvement of cardiorespiratory fitness. However, as the participants cycled faster during the field test than during daily cycling, the results should be interpreted with caution. PMID:17021003

de Geus, B; De Smet, S; Nijs, J; Meeusen, R

2007-01-01

53

Collaboration essential for an energy neutral urban water cycle.  

PubMed

Two Dutch water boards prepared a Master Plan with measures to substantially reduce their energy use by 2027. In total, more than 100 measures were identified such as bubble aeration and heat recovery from effluent. Together these measures result in a 90-95% reduction in energy use at the water boards. However, for the whole urban water cycle, thus including the energy required for warm water use in households, the total energy reduction from these measures at the water boards is only 5-6%. To attain the objective to have an energy neutral urban water cycle, collaboration with other sectors such as housing, energy, agriculture and industry will be essential. Active collaboration of the water boards through the incorporation of energy efficient water measures as part of the carbon neutral effort of cities is recognized to be a promising strategy. PMID:23676381

Frijns, Jos; Mulder, Mirabella; Roorda, Jelle; Schepman, Hans; Voskamp, Tom

2013-01-01

54

Energy Demand in China (Carbon Cycle 2.0)  

ScienceCinema

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

Price, Lynn

2011-06-08

55

Energy Demand in China (Carbon Cycle 2.0)  

SciTech Connect

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

Price, Lynn

2010-02-02

56

Energy use in the production of primary aluminum  

Microsoft Academic Search

As a part of a study of the possibilities of using alternate energy systems in industry, a review of the processes used in the production of primary aluminum from bauxite was carried out. An overview of the aluminum industry and a detailed process analysis with particular emphasis on the energy requirements is followed by a brief look at future possibilities.

Boercker

1978-01-01

57

Lifecycle primary energy analysis of conventional and passive houses  

Microsoft Academic Search

In this study we analyse the primary energy implications of thermal envelope designs and construction systems, for a 4-storey apartment building, including the full lifecycle phases and the entire energy chains. We maintain the architectural design of the reference building, and alter the thermal properties of the envelope components and include heat recovery of ventilation air to achieve buildings with

Ambrose Dodoo; Leif Gustavsson; Roger Sathre

2012-01-01

58

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

PubMed

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

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

2014-06-01

59

A Satellite View of Global Water and Energy Cycling  

NASA Astrophysics Data System (ADS)

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

Houser, P. R.

2012-12-01

60

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

61

Carbon Cycle 2.0: Nitash Balsara: Energy Storage  

ScienceCinema

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

Nitash Balsara

2010-09-01

62

Carbon Cycle 2.0: Nitash Balsara: Energy Storage  

SciTech Connect

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

Nitash Balsara

2010-02-16

63

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

64

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

PubMed

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

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

2014-04-15

65

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

PubMed Central

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

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

2014-01-01

66

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

PubMed

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

Cai, Hao; Wang, Michael Q

2014-10-21

67

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

68

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

Microsoft Academic Search

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

Paul Denholm; Gerald L. Kulcinski

2004-01-01

69

Sharp knee phenomenon of primary cosmic ray energy spectrum  

E-print Network

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

Ter-Antonyan, Samvel

2014-01-01

70

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

71

Wood energy fuel cycle optimization in beech and spruce forests  

NASA Astrophysics Data System (ADS)

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

Meyer, Nickolas K.; Mina, Marco

2012-03-01

72

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

73

Conversion of ocean thermal energy with the salt cycle  

SciTech Connect

A temperature gradient exists between the top and the depths of oceans, the Salt Cycle is targeted at converting this thermal energy. The phases of certain solutions (liquid-liquid or solid-liquid) separate out at lower temperatures enabling the separation of the solute. By placing the solute behind a semipermeable membrane, at a higher temperature, an osmotic pressure can be developed. The pressure released into a turbine can generate power or may be put to other uses like desalination.

Saikia, S.

1997-07-01

74

Energy recovery system using an organic rankine cycle  

DOEpatents

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

Ernst, Timothy C

2013-10-01

75

A study of dynamic energy equations for Stirling cycle analysis  

NASA Technical Reports Server (NTRS)

An analytical and computer study of the dynamic energy equations that describe the physical phenomena that occurs in a Stirling cycle engine. The basic problem is set up in terms of a set o hyperbolic partial differential equations. The characteristic lines are determined. The equations are then transformed to ordinary differential equations that are valid along characteristic lines. Computer programs to solve the differential equations and to plot pertinent factors are described.

Larson, V. H.

1983-01-01

76

Energy use in the production of primary aluminum  

Microsoft Academic Search

An overview of the aluminum industry is followed by an energy analysis of the processes used in the production of primary aluminum from bauxite. Calcining of alumina at about 1150°C, electrolytic reduction of alumina to aluminum metal (approx. 950°C) requiring about 15,600 kWh\\/ton Al, and anode baking at 1100°C are identified as the most-demanding processes. This analysis shows that present

Boercker

1979-01-01

77

Energy life cycle cost analysis: Guidelines for public agencies  

SciTech Connect

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

NONE

1995-03-01

78

Alterations of cell cycle regulatory genes in primary (de novo) and secondary glioblastomas  

Microsoft Academic Search

Primary glioblastomas develop rapidly de novo through a genetic pathway characterized by amplification\\/overexpression of EGFR and of MDM2 genes. Secondary glioblastomas develop more slowly through progression from low grade or anaplastic astrocytoma and show\\u000a a high incidence of a p53 mutation. In the present study, primary and secondary glioblastomas were analyzed for p16 deletions and CDK4 amplification by differential PCR

Wojciech Biernat; Yasuo Tohma; Yasuhiro Yonekawa; Paul Kleihues; Hiroko Ohgaki

1997-01-01

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

2011-06-15

80

Long-term global nuclear energy and fuel cycle strategies  

SciTech Connect

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

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

1997-09-24

81

Modeling fossil energy demands of primary nonferrous metal production: the case of copper.  

PubMed

The methodologies for life cycle impact assessment (LCIA) of metal resources are rather diverse. Some LCIA methods are based on ore grade changes, but they typically do not consider the impact of changes in primary metal extraction technology. To characterize the impact of technology changes for copper, we modeled and analyzed energy demand, expressed in fossil energy equivalents (FEE) per kilogram of primary copper, taking into account the applied mining method and processing technology. The model was able to capture variations in reported energy demands of selected mining sites (FEE: 0.07 to 0.84 MJ-eq/kg ore) with deviations of 1 to 30%. Applying the model to a database containing global mine production data resulted in energy demand median values of around 50 MJ/kg Cu irrespective of the processing route, even though median values of ore demands varied between processing routes from ca. 35 (underground, conventional processing) to 200 kg ore/kg Cu (open pit, solvent-extraction, and electrowinning), as high specific ore demands are typically associated with less energy intensive extraction technologies and vice versa. Thus, only considering ore grade in LCIA methods without making any differentiation with regard to employed technology can produce misleading results. PMID:24266773

Swart, Pilar; Dewulf, Jo

2013-12-17

82

Nitrogen cycling networks of coastal ecosystems: influence of trophic status and primary producer form  

Microsoft Academic Search

We have used ecological network analysis to compare nitrogen cycles from five well-researched coastal ecosystems. These included a representative ricefield and two lagoons (Tancada and Encanysada lagoons) in the Ebro River delta, Spain; a region of the Sacca di Goro, a lagoon at the mouth of the Po River, Italy; and a drowned river estuary in North Carolina, USA, the

Robert R. Christian; Elisenda Forés; Francisco Comin; Pierluigi Viaroli; Mariachiara Naldi; Ireneo Ferrari

1996-01-01

83

Recovered Energy Generation Using an Organic Rankine Cycle System  

SciTech Connect

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

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

2009-01-01

84

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

Microsoft Academic Search

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

João Carlos de Oliveira Matias; Tessaleno Campos Devezas

2007-01-01

85

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

86

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

87

The contribution of GABA to glutamate/glutamine cycling and energy metabolism in the rat cortex in vivo  

PubMed Central

Previous studies have shown that the glutamate/glutamine (Glu/Gln) neurotransmitter cycle and neuronal glucose oxidation are proportional (1:1), with increasing neuronal activity above isoelectricity. GABA, a product of Glu metabolism, is synthesized from astroglial Gln and contributes to total Glu/Gln neurotransmitter cycling, although the fraction contributed by GABA is unknown. In the present study, we used 13C NMR spectroscopy together with i.v. infusions of [1,6-13C2]glucose and [2-13C]acetate to separately determine rates of Glu/Gln and GABA/Gln cycling and their respective tricarboxylic acid cycles in the rat cortex under conditions of halothane anesthesia and pentobarbital-induced isoelectricity. Under 1% halothane anesthesia, GABA/Gln cycle flux comprised 23% of total (Glu plus GABA) neurotransmitter cycling and 18% of total neuronal tricarboxylic acid cycle flux. In isoelectric cortex, glucose oxidation was reduced >3-fold in glutamatergic and GABAergic neurons, and neurotransmitter cycling was below detection. Hence, in both cell types, the primary energetic costs are associated with neurotransmission, which increase together as cortical activity is increased. The contribution of GABAergic neurons and inhibition to cortical energy metabolism has broad implications for the interpretation of functional imaging signals. PMID:15809416

Patel, Anant B.; de Graaf, Robin A.; Mason, Graeme F.; Rothman, Douglas L.; Shulman, Robert G.; Behar, Kevin L.

2005-01-01

88

Modeling the Q-cycle mechanism of transmembrane energy conversion  

E-print Network

The Q-cycle mechanism plays an important role in the conversion of the redox energy into the energy of the proton electrochemical gradient across the biomembrane. The bifurcated electron transfer reaction, which is built into this mechanism, recycles one electron, thus, allowing to translocate two protons per one electron moving to the high-potential redox chain. We study a kinetic model of the Q-cycle mechanism in an artificial system which mimics the bf complex of plants and cyanobacteria in the regime of ferredoxin-dependent cyclic electron flow. Using methods of condensed matter physics, we derive a set of master equations and describe a time sequence of electron and proton transfer reactions in the complex. We find energetic conditions when the bifurcation of the electron pathways at the positive side of the membrane occurs naturally, without any additional gates. For reasonable parameter values, we show that this system is able to translocate more than 1.8 protons, on average, per one electron, with a thermodynamic efficiency of the order of 32% or higher.

Anatoly Yu. Smirnov; Franco Nori

2011-06-29

89

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

Microsoft Academic Search

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

M. Q. Wang; S. Plotkin; D. J. Santini; J. He; L. Gaines; P. Patterson

1997-01-01

90

Gopher mounds decrease nutrient cycling rates and increase adjacent vegetation in volcanic primary succession.  

PubMed

Fossorial mammals may affect nutrient dynamics and vegetation in recently initiated primary successional ecosystems differently than in more developed systems because of strong C and N limitation to primary productivity and microbial communities. We investigated northern pocket gopher (Thomomys talpoides) effects on soil nutrient dynamics, soil physical properties, and plant communities on surfaces created by Mount St. Helens' 1980 eruption. For comparison to later successional systems, we summarized published studies on gopher effects on soil C and N and plant communities. In 2010, 18 years after gopher colonization, we found that gophers were active in ~2.5 % of the study area and formed ~328 mounds ha(-1). Mounds exhibited decreased species density compared to undisturbed areas, while plant abundance on mound margins increased 77 %. Plant burial increased total soil carbon (TC) by 13 % and nitrogen (TN) by 11 %, compared to undisturbed soils. Mound crusts decreased water infiltration, likely explaining the lack of detectable increases in rates of NO3-N, NH4-N or PO4-P leaching out of the rooting zone or in CO2 flux rates. We concluded that plant burial and reduced infiltration on gopher mounds may accelerate soil carbon accumulation, facilitate vegetation development at mound edges through resource concentration and competitive release, and increase small-scale heterogeneity of soils and communities across substantial sections of the primary successional landscape. Our review indicated that increases in TC, TN and plant density at mound margins contrasted with later successional systems, likely due to differences in physical effects and microbial resources between primary successional and older systems. PMID:25260998

Yurkewycz, Raymond P; Bishop, John G; Crisafulli, Charles M; Harrison, John A; Gill, Richard A

2014-12-01

91

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

92

A biogeochemical model for phosphorus and nitrogen cycling in the Eastern Mediterranean Sea. Part 2. Response of nutrient cycles and primary production to anthropogenic forcing: 1950-2000  

NASA Astrophysics Data System (ADS)

Anthropogenic inputs of nutrient phosphorus (P) and nitrogen (N) to the Eastern Mediterranean Sea (EMS) increased significantly after 1950. Nonetheless, the EMS remained ultra-oligotrophic, with eutrophication only affecting a restricted number of nearshore areas. To better understand this apparent contradiction, we reconstructed the external inputs of reactive P and N to the EMS for the period 1950 to 2000. Although the inputs associated with atmospheric deposition and river discharge more than doubled, the inflow of surface water from the Western Mediterranean Sea (WMS) remained the dominant source of nutrient P and N to the EMS during the second half of the 20th century. The combined external input of reactive P rose by 24% from 1950 to 1985, followed by a slight decline. In contrast, the external reactive N input increased continuously from 1950 to 2000, with a 62% higher input in 2000 compared to 1950. When imposing the reconstructed inputs to the dynamic model of P and N cycling in the EMS developed in the companion paper, a maximum increase of primary production of only 16% is predicted. According to the model, integrated over the period 1950-2000, outflow of Levantine Intermediate Water (LIW) to the WMS exported the equivalent of about one third of the P supplied in excess of the 1950 input, while another one third was translocated to the Eastern Mediterranean Deep Water (EMDW). Together, both mechanisms efficiently counteracted enhanced P input to the EMS, by drawing nutrient P away from primary producers in the surface waters. Furthermore, between 1950 and 2000, inorganic and organic dissolved N:P ratios increased in all water masses. Thus, the EMS became even more P limited because of anthropogenic nutrient inputs. A model simulation incorporating the circulation changes accompanying the Eastern Mediterranean Transient (EMT) between 1987 and 2000 yielded a 4% increase of EMS primary productivity relative to the baseline scenario.

Powley, H. R.; Krom, M. D.; Emeis, K.-C.; Van Cappellen, P.

2014-11-01

93

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

PubMed Central

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

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

2014-01-01

94

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

PubMed

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

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

2014-09-30

95

Vol. 16, No. 2 May 2006Global Energy and Water Cycle Experiment World Climate Research Programme  

E-print Network

's climate system is an energy cycle that converts absorbed solar radiation into heat and associated by the exchanges of energy and water. Although some statistics of these varia- tions may be static, the energyNEWSNEWS Vol. 16, No. 2 May 2006Global Energy and Water Cycle Experiment World Climate Research

96

Primary cosmic-ray energy spectrum around the knee energy region measured by the Tibet hybrid  

E-print Network

Primary cosmic-ray energy spectrum around the knee energy region measured by the Tibet hybrid Academy of Sciences, Beijing 100080, China #12;Proton spectrum by Tibet hybrid experiment 2 16 Advanced Media Network Center, Utsunomiya University, Utsunomiya 321-8585, Japan 17 National Institute

97

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

NASA Technical Reports Server (NTRS)

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

Cullen, John J.

1995-01-01

98

Energy harvesting measurements from stall flutter limit cycle oscillations  

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

99

The Organic Rankine Cycle System, Its Application to Extract Energy From Low Temperature Waste Heat  

E-print Network

THE ORGANIC RANKINE CYCLE SYSTEM, ITS APPLICATION TO EXTRACT ENERGY FROM LOW TEMPERATURE WASTE HEAT Robert H. Sawyer Shoji Ichikawa AFI Energy Systems AFI Energy Systems Livingston, New Jersey Livingston, New Jersey ABSTRACT The conservation...THE ORGANIC RANKINE CYCLE SYSTEM, ITS APPLICATION TO EXTRACT ENERGY FROM LOW TEMPERATURE WASTE HEAT Robert H. Sawyer Shoji Ichikawa AFI Energy Systems AFI Energy Systems Livingston, New Jersey Livingston, New Jersey ABSTRACT The conservation...

Sawyer, R. H.; Ichikawa, S.

1980-01-01

100

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

101

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

102

Continuous energy variation during the seizure cycle: towards an on-line accumulated energy  

PubMed Central

Objective Increases in accumulated energy on intracranial EEG are associated with oncoming seizures in retrospective studies, supporting the idea that seizures are generated over time. Published seizure prediction methods require comparison to ‘baseline’ data, sleep staging, and selecting seizures that are not clustered closely in time. In this study, we attempt to remove these constraints by using a continuously adapting energy threshold, and to identify stereotyped energy variations through the seizure cycle (inter-, pre-, post- and ictal periods). Methods Accumulated energy was approximated by using moving averages of signal energy, computed for window lengths of 1 and 20 min, and an adaptive decision threshold. Predictions occurred when energy within the shorter running window exceeded the decision threshold. Results Predictions for time horizons of less than 3 h did not achieve statistical significance in the data sets analyzed that had an average inter-seizure interval ranging from 2.9 to 8.6 h. 51.6% of seizures across all patients exhibited stereotyped pre-ictal energy bursting and quiet periods. Conclusions Accumulating energy alone is not sufficient for predicting seizures using a 20 min running baseline for comparison. Stereotyped energy patterns through the seizure cycle may provide clues to mechanisms underlying seizure generation. Significance Energy-based seizure prediction will require fusion of multiple complimentary features and perhaps longer running averages to compensate for post-ictal and sleep-induced energy changes. PMID:15721065

Esteller, Rosana; Echauz, Javier; D'Alessandro, Maryann; Worrell, Greg; Cranstoun, Steve; Vachtsevanos, George; Litt, Brian

2010-01-01

103

Pareto Ant Colony Algorithm for Building Life Cycle Energy Consumption Optimization  

Microsoft Academic Search

\\u000a This article aims at realizing optimal building energy consumption in its whole life cycle, and develops building life cycle\\u000a energy consumption model (BLCECM), as well as optimizes the model by Ant Colony Algorithm (ACA). Aiming at the complexity\\u000a and multi-objective principle of building life cycle energy consumption, this research tries to modify Pareto Ant Colony Algorithm\\u000a (PACA), making it fit

Yan Yuan; Jingling Yuan; Hongfu Du; Li Li

104

Life Cycles  

NSDL National Science Digital Library

Students extend their knowledge of matter and energy cycles in organisms to engineering life cycle assessment of products. They learn about product life cycle assessment and the flow of energy through the cycle, comparing it to the flow of nutrients and energy in the life cycles of organisms.

Integrated Teaching And Learning Program

105

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

Microsoft Academic Search

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 (NHâHSOâ) 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,

Wentworth

1992-01-01

106

Thermochemical cycles for energy storage: Thermal decomposition of ZnSO4 systems  

Microsoft Academic Search

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

W. E. Wentworth

1992-01-01

107

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

SciTech Connect

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

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

1980-01-01

108

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

PubMed Central

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, Raphael; Cunha de Alencar, Bruna; Jouve, Mabel; Berre, Stefano; Le Bouder, Emmanuel; Schindler, Michael; Varthaman, Aditi; Gobert, Francois-Xavier

2012-01-01

109

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] [ORNL

2011-05-01

110

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

PubMed

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 2.2 with increased MAP across the precipitation gradient. Increased water availability in excess of plant demand is likely to have decreased the other resources for plant growth. Patterns of nutrient cycling and other factors that affect plant growth suggest that increased nutrient limitation in wetter sites could be the direct cause of the decline in NPP. Foliar nitrogen (N) and soil N availability decreased with increased precipitation, corresponding with the decrease in forest growth. In contrast, patterns of foliar and soil phosphorus (P) did not correspond with the decrease in growth; P availability was highest at either end of the precipitation gradient and lowest across the middle. Natural abundance of ?(15)N in foliage and soils decreased with increased precipitation, further supporting the idea that N availability declined. Decreased N availability was associated with a decrease in soil reduction-oxidation potentials. Oxygen limitation in soil microsites was a factor at all sites, but became increasingly widespread at higher MAP regimes. There was no strong evidence that soil oxygen availability, expressed in foliar ?(13)C values, directly limited plant growth. In addition foliar micronutrients either showed no change (Ca, Mg) or declined (Al, Fe) with increased MAP while soil pH was low but constant, suggesting that toxic elements in the soil solution were also not direct factors in decreased plant growth across the gradient. Thus, the decline in NPP with associated MAP appeared to be most directly associated with decreased N availability in these humid forests. Fluctuating anaerobic conditions that increased in intensity and duration with increased rainfall could be a mechanism that slows decomposition and N mineralization while concurrently increasing P solubility from soil mineral-bound pools. PMID:24549913

Schuur, E A; Matson, P A

2001-08-01

111

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

112

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

2011-06-01

113

Evaluation of high-energy lithium thionyl chloride primary cells  

NASA Technical Reports Server (NTRS)

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

Frank, H. A.

1980-01-01

114

Demonstrated fossil-fuel-free energy cycle using magnesium and laser  

NASA Astrophysics Data System (ADS)

The authors propose an energy cycle based on a renewable fuel. Magnesium is chosen as an energy carrier and is combusted with water to retrieve energy using many power devices. MgO, the combustion residue, is reduced back to Mg by laser radiation generated from solar and other renewable energy sources. They have achieved an energy recovery efficiency of 42.5% for converting MgO to magnesium, using a laser. Combined with a demonstrated 38% efficiency for converting an artificial sunlight source (metal halide lamp) into laser output energy indicates that the proposed energy cycle is already in a feasible range for practical use.

Yabe, T.; Uchida, S.; Ikuta, K.; Yoshida, K.; Baasandash, C.; Mohamed, M. S.; Sakurai, Y.; Ogata, Y.; Tuji, M.; Mori, Y.; Satoh, Y.; Ohkubo, T.; Murahara, M.; Ikesue, A.; Nakatsuka, M.; Saiki, T.; Motokoshi, S.; Yamanaka, C.

2006-12-01

115

Absorption Cycle Fundamentals and Applications Guidelines for Distillation Energy Savings  

E-print Network

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

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

1984-01-01

116

Energy harvesting, reuse and upgrade to reduce primary energy usage in the USA  

Microsoft Academic Search

Two-thirds of input energy for electricity generation in the USA is lost as heat during conversion processes. Additionally, 12.5% of primary fuel and 20.3% of electricity are employed for space heating, water heating, and refrigeration where low-grade heat could suffice. The potential for harnessing waste heat from power generation and thermal processes to perform such tasks is assessed. By matching

Alexander S. Rattner; Srinivas Garimella

2011-01-01

117

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

118

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

119

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

E-print Network

Life-Cycle Greenhouse Gas and Energy Analyses of Algae Biofuels Production Transportation Energy The Issue Algae biofuels directly address the Energy Commission's Public Interest Energy Research the sustainability of algae biofuels suggests that the lifecycle performance of these fuels is a critical

120

Life cycle inventory and energy analysis of cassava-based Fuel ethanol in China  

Microsoft Academic Search

The Chinese government is developing biomass ethanol as one of its automobile fuels for energy security and environmental improvement reasons. The cassava is an alternative feedstock to produce this ethanol fuel. Its performance of environmental impacts and energy efficiency is the critical issue. Life cycle assessment has been used to identify and quantify the environment emissions, energy consumption and energy

Rubo Leng; Chengtao Wang; Cheng Zhang; Du Dai; Gengqiang Pu

2008-01-01

121

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

NASA Technical Reports Server (NTRS)

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

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

2001-01-01

122

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

NASA Astrophysics Data System (ADS)

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

Berghorn, George H.

123

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

124

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

125

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

SciTech Connect

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

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

2012-02-29

126

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

SciTech Connect

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

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

2013-08-01

127

Delay and Energy Models for Polling Based MAC Protocols with Sleep-Wake Cycles  

E-print Network

of sleep-wake cycles have been studied extensively in literature [1], [2]. The performanceDelay and Energy Models for Polling Based MAC Protocols with Sleep-Wake Cycles Haiming Yang, are particularly suitable for centralized, polling based MAC protocols though their performance with sleep

Sikdar, Biplab

128

Life Cycle and Green Cost Analysis of Energy-Efficient Lighting for Hotels  

Microsoft Academic Search

About 20% of the electricity use in Hong Kong's hotel operations is for electric lighting. Life cycle cost technique was used in the analysis ofreplacing general lighting service (GLS) lamps with energy saving light bulbs in hotel corridors. Discounting approach was adopted to compute the net present value of electricity cost over a life cycle of five years. Two city

Joseph C. Lam; Wilco W. Chan

2001-01-01

129

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

130

Life-cycle assessment in the renewable energy sector  

Microsoft Academic Search

The Polish energy industry is facing challenges regarding energetic safety, competitiveness, improvement of domestic companies and environmental protection. Ecological guidelines concern the elimination of detrimental solutions, and effective energy management, which will form the basis for sustainable development. The Polish power industry is required to systematically increase the share of energy taken from renewable sources in the total energy sold

Ma?gorzata Góralczyk

2003-01-01

131

Comparison of Life Cycle Emissions and Energy Consumption for  

E-print Network

of environmentally adapted lubricants have been proposed in response to the environmental and health impacts prevalent than the latter. A comparative life cycle assessment of water- and gas- based systems has shown the health and environmental advantages of air-based systems. Although delivery conditions were found

Clarens, Andres

132

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

133

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

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

134

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

E-print Network

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

Massachusetts at Amherst, University of

135

Analysis of energy consumption and powertrain parameters optimization of BEV based on running cycle  

Microsoft Academic Search

Through the analysis of Running cycle of Changsha City, and according to the automobile running equation, the minimal energy of driving and braking under the sampling points of 0.1 second interval is analyzed and summed, the recycle of braking energy of motor is analyzed, two formulas for calculating the energy consumption of BEV are derived based on the running and

Zhou Bing; Jiang Qinghua; Yang Yi; Wang Jisheng

2010-01-01

136

Energy and CO 2 life-cycle analyses of wind turbines—review and applications  

Microsoft Academic Search

Despite the fact that the structure and technology of most modern wind turbines differs little over a wide range of power ratings, results from existing life-cycle assessments of their energy and CO2 intensity show considerable variations. While the range of energy intensities reflects economies of scale, their scatter is due to discrepancies in the energy contents of materials and the

Manfred Lenzen; Jesper Munksgaard

2002-01-01

137

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.

138

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

NASA Astrophysics Data System (ADS)

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 at the top of the structure, of CO2, air temperature and humidity along a vertical profile and of relevant physical parameters of the forest ecosystem. The Ankasa flux tower is the first in the African continent collecting data on CO2 exchanges over a tropical primary forest, and from its activity a breakthrough in the understanding of the carbon cycling in this kind of environment is expected. Moreover the knowledge gained on the carbon balance of this primary forest can be used as a reference to thoroughly evaluate the impacts of deforestation, beyond the decrease of carbon stocks. The analysis of preliminary data collected in the first week of August 2008 shows a daily uptake of 1.33±0.73 gC m-2 d-1 (mean±s.e.) and highlights the large magnitude of the storage of CO2 within the canopy space causing a discrepancy between the CO2 flux observed at the top of the tower (Fc) and the overall net ecosystem exchange (NEE). During night-time NEE reveals a respiration rate up to 4 times higher than Fc while in the first hours after dawn assimilation of CO2 in the canopy space is sensed at the top level of measurement with about 3 hours of delay. Associated to the tower site, a field campaign to estimate biomass and biodiversity was carried out. Two transects were demarcated for a total surface of 2 ha. Each transect measuring 1000 m x 10 m, they were divided into 10 subplots and intersected each other at the centre and they were perpendicular to one another. The point of intersection is located on the tower where they are located all the instrumentation for monitoring carbon fluxes. All the data is still being processed but the first analysis has already highlighted the high biodiversity that characterizes Ankasa forest.

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

2009-04-01

139

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

Microsoft Academic Search

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

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

2008-01-01

140

Life-cycle carbon and cost analysis of energy efficiency measures in new commercial buildings  

Microsoft Academic Search

Energy efficiency in new building construction has become a key target to lower nation-wide energy use. The goals of this paper are to estimate life-cycle energy savings, carbon emission reduction, and cost-effectiveness of energy efficiency measures in new commercial buildings using an integrated design approach, and estimate the implications from a cost on energy-based carbon emissions. A total of 576

Joshua Kneifel

2010-01-01

141

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

PubMed

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

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

2013-04-15

142

Optimizing the electrical energy conversion cycle of dielectric elastomer generators.  

PubMed

A strategy to control the electrical charge is developed to achieve high energy density of soft dielectric elastomer generators for energy harvesting. The strategy is analytically shown and experimentally demonstrated to produce the highest energy density ever reported for a soft generator. PMID:25113278

Shian, Samuel; Huang, Jiangshui; Zhu, Shijie; Clarke, David R

2014-10-01

143

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

144

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

145

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

Microsoft Academic Search

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

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

2003-01-01

146

Coupling of two multistep catalytic cycles for the one-pot synthesis of propargylamines from alcohols and primary amines on a nanoparticulated gold catalyst.  

PubMed

A one-pot reaction was performed with a nanoparticulated gold catalyst. A secondary amine is formed through N-monoalkylation of a primary amine with an alcohol by a borrowing hydrogen methodology in a three-step reaction. The secondary amine formed enters into a second A(3)-coupling cycle to give propargylamines. The multistep reaction requires a gold species formed and stabilized on a ceria surface. PMID:22996294

Corma, Avelino; Navas, Javier; Sabater, María J

2012-10-29

147

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. PMID:20881883

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

2011-01-01

148

The coupling between primary and secondary cosmic-ray muon variations at high energies  

Microsoft Academic Search

The muon sea-level integral multiplicity and the coefficients of coupling between primary and secondary muon variations were derived as functions of primary energy for various absorber thicknesses and zenith angles using the Cocconi-Koester-Perkins interaction model. The calculated multiplicities were found to agree at low energies with those derived from geomagnetic data and to be in general accordance with those obtained

F. El Bedewi; A. Goned

1971-01-01

149

FULL FUEL CYCLE ASSESSMENT WELL TO TANK ENERGY INPUTS,  

E-print Network

: Energy Commission Air Resources Board iii #12;ABSTRACT Pursuant to AB1007, the California Energy Commission and California Air Resources Board are developing a "State Plan to Increase the Use of Alternative material increases in air or water pollution. To ensure that fair comparisons are made between the various

150

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

E-print Network

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

S. V. Ter-Antonyan

2007-06-27

151

Carbon Cycles  

NSDL National Science Digital Library

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

Integrated Teaching And Learning Program

152

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

SciTech Connect

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 shopping answers to the total energy and environmental implications of alternative technologies, as well as providing employment and income consequences. In one recently completed study, the lifetime impacts of scenarios involving the production and use of biomass ethanol transportation fuels were assessed. In an ongoing study, the lifetime impacts of electric-powered vehicles versus conventional fuels are being assessed. In a proposed study, the impacts of recycled office paper versus office paper from virgin sources would be assessed. A LCA proceeds by developing mass and energy inventories during all phases of the life-cycle. Special attention is given to energy consumption and environmental releases. Economics are incorporated by evaluating the macroeconomic impacts of the alternative policies, such as employment, wages, and output. Economics can also be incorporated by attempting to place values on the damages imposed by the environmental releases associated with alternative scenarios. This paper discusses life-cycle assessment techniques and their application to building energy issues. Life-cycle assessments show great promise for analysis of buildings energy policy questions.

Shankle, S.A.

1994-08-01

153

Energy life-cycle analysis modeling and decision support tool  

SciTech Connect

As one of DOE`s five multi-program national laboratories, Pacific Northwest Laboratory (PNL) develops and deploys technology for national missions in energy and the environment. The Energy Information Systems Group, within the Laboratory`s Computer Sciences Department, focuses on the development of the computational and data communications infrastructure and automated tools for the Transmission and Distribution energy sector and for advanced process engineering applications. The energy industry is being forced to operate in new ways and under new constraints. It is in a reactive mode, reacting to policies and politics, and to economics and environmental pressures. The transmission and distribution sectors are being forced to find new ways to maximize the use of their existing infrastructure, increase energy efficiency, and minimize environmental impacts, while continuing to meet the demands of an ever increasing population. The creation of a sustainable energy future will be a challenge for both the soft and hard sciences. It will require that we as creators of our future be bold in the way we think about our energy future and aggressive in its development. The development of tools to help bring about a sustainable future will not be simple either. The development of ELCAM, for example, represents a stretch for the computational sciences as well as for each of the domain sciences such as economics, which will have to be team members.

Hoza, M.; White, M.E.

1993-06-01

154

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

NASA Technical Reports Server (NTRS)

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

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

1976-01-01

155

Co-utilization of biomass and natural gas in combined cycles through primary steam reforming of the natural gas  

Microsoft Academic Search

Power production from biomass can occur through external combustion (e.g. steam cycles, organic Rankine cycles, Stirling engines), or internal combustion after gasification or pyrolysis (e.g. gas engines, IGCC). External combustion has the disadvantage of delivering limited conversion efficiencies (max 30–35%). Internal combustion has the potential of high efficiencies, but it always needs a severe and mostly problematic gas cleaning.The present

J. De Ruyck; F. Delattin; S. Bram

2007-01-01

156

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

National Technical Information Service (NTIS)

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) bat...

K. K. Humphreys, D. R. Brown

1990-01-01

157

Modulation of Adenylate Energy Charge During the Swarmer Cycle of Hyphomicrobium neptunium  

PubMed Central

Adenylate energy charge was measured in the budding bacterium Hyphomicrobium neptunium through the course of the swarmer cycle. The energy charge was modulated, being low in swarm cells (0.64) and in cells initiating bud formation (0.57), an event which coincides with a round of DNA replication. PMID:6826528

Emala, Mary A.; Weiner, Ronald M.

1983-01-01

158

Estimation of life cycle energy consumption and CO 2 emission of office buildings in Japan  

Microsoft Academic Search

The purpose of this study is to quantify the total amount of energy consumption and CO2 emission caused by the construction, operation, maintenance, and renovation of office buildings in Japan. In order to quantify the life cycle energy consumption and CO2 emission of a building, it is necessary to obtain an estimate of the total quantity of domestic products and

Michiya Suzuki; Tatsuo Oka

1998-01-01

159

Sources of Business Cycles in Energy Producing Economies – The case of Norway and United Kingdom  

Microsoft Academic Search

This paper analyses the sources of business cycles in economies that have an important energy producing sector. Especially, I investigate the effects of oil and gas extractions (energy booms) on the manufacturing sector, and analyse whether there is any evidence of a \\

Hilde Christiane Bjørnland

1996-01-01

160

A comparative life cycle energy cost analysis of photovoltaic and fuel generator for load shedding application  

Microsoft Academic Search

Comparative life cycle energy cost analysis for different electricity generators (photovoltaic generator, kerosene generator and diesel generator) used during load shedding is presented. The parameters considered for calculation of the unit cost of energy are: the discount rate, inflation rate, IREDA loan facility to promote PV, operation and maintenance cost of PV and fuel generator (FG) set and the associated

P. K Koner; V Dutta; K. L Chopra

2000-01-01

161

Life Cycle Energy Demand and Greenhouse Gas Emissions from an Amonix High Concentrator Photovoltaic System  

Microsoft Academic Search

With a growing demand for renewable energy, attention is drawn to concentrator photovoltaic (PV) systems, which require minimal amount of high efficiency solar cell materials. We investigate select life cycle environmental metrics for the 24 kW Amonix concentrator PV system. The results show that this system pays back the initial energy investment for its production in 1.3 yrs and generates

H. C. Kim; V. M. Fthenakis

2006-01-01

162

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

Microsoft Academic Search

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

V. Maizza; A. Maizza

2001-01-01

163

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

Microsoft Academic Search

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

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

2011-01-01

164

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

165

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

166

High-energy sub-cycle optical waveform synthesizer  

E-print Network

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

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

2012-01-01

167

Recovered Energy Generation Using an Organic Rankine Cycle System  

Microsoft Academic Search

This paper describes the results of a project demonstrating the technical and economic feasibility of capturing thermal energy from a 35,000 hp (27 MW) gas turbine driving a natural gas pipeline compressor with a Recovered Energy Generation (REG) system to produce 5.5 MW of electricity with no additional fuel and near-zero emissions. The REG is based on a modified Organic

Neil Leslie; Richard Sweetser; Ohad Zimron; Therese K Stovall

2009-01-01

168

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

169

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

170

Daily cycle of the surface energy balance in Antarctica and the influence of clouds  

Microsoft Academic Search

We present the summertime daily cycle of the Antarctic surface energy balance (SEB) and its sensitivity to cloud cover.\\u000aWe use data of automatic weather stations (AWS) located in four major Antarctic climate zones: the coastal ice shelf, the\\u000acoastal and interior katabatic wind zone and the interior plateau. Absorbed short wave radiation drives the daily cycle of\\u000athe SEB,

Michiel Van Den Broeke; Carleen Reijmer; Dirk Van As; Wim Boot

2006-01-01

171

Fast-cycling superconducting synchrotrons and possible path to the future of US experimental high-energy particle physics  

SciTech Connect

The authors outline primary physics motivation, present proposed new arrangement for Fermilab accelerator complex, and then discuss possible long-range application of fast-cycling superconducting synchrotrons at Fermilab.

Piekarz, Henryk; /Fermilab

2008-02-01

172

Boom and Bust Cycles in Wind Energy Diffusion Due to Inconsistency and Short-term Bias in National Energy Policies  

Microsoft Academic Search

Common knowledge in the wind industry pinpoints inconsistent policy, such as the production- tax credit scheme in the US, as a key source for boom and bust cycles in the wind energy industry. This paper looks at the sources of the industry boom and bust via a system dynamics model for diffusion of wind energy technology. A model is developed

Katherine L. Dykes; John D. Sterman

173

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

174

The energy dependence of the secondary to primary ratio. [in cosmic rays  

NASA Technical Reports Server (NTRS)

The energy dependence of the secondary to primary ratios in the Cosmic Rays can be explained by a model accounting for the scattering of the particles by self-generated Alfven waves. This model predicts an energy-dependent truncation of the pathlength distribution.

Margolis, S. H.; Bussard, R. W.

1983-01-01

175

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

176

Energy and nutrient cycling in pig production systems  

NASA Astrophysics Data System (ADS)

United States pig production is centered in Iowa and is a major influence on the economic and ecological condition of that community. A pig production system includes buildings, equipment, production of feed ingredients, feed processing, and nutrient management. Although feed is the largest single input into a pig production system, nearly 30% of the non-solar energy use of a conventional--mechanically ventilated buildings with liquid manure handling--pig production system is associated with constructing and operating the pig facility. Using bedded hoop barns for gestating sows and grow-finish pigs reduces construction resource use and construction costs of pig production systems. The hoop based systems also requires approximately 40% less non-solar energy to operate as the conventional system although hoop barn-based systems may require more feed. The total non-solar energy input associated with one 136 kg pig produced in a conventional farrow-to-finish system in Iowa and fed a typical corn-soybean meal diet that includes synthetic lysine and exogenous phytase is 967.9 MJ. Consuming the non-solar energy results in emissions of 79.8 kg CO2 equivalents. Alternatively producing the same pig in a system using bedded hoop barns for gestating sows and grow-finish pigs requires 939.8 MJ/pig and results in emission of 70.2 kg CO2 equivalents, a reduction of 3 and 12% respectively. Hoop barn-based swine production systems can be managed to use similar or less resources than conventional confinement systems. As we strive to optimally allocate non-solar energy reserves and limited resources, support for examining and improving alternative systems is warranted.

Lammers, Peter J.

177

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

178

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

179

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

180

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

181

From Cycling Between Coupled Reactions to the Cross-Bridge Cycle: Mechanical Power Output as an Integral Part of Energy Metabolism  

PubMed Central

ATP delivery and its usage are achieved by cycling of respective intermediates through interconnected coupled reactions. At steady state, cycling between coupled reactions always occurs at zero resistance of the whole cycle without dissipation of free energy. The cross-bridge cycle can also be described by a system of coupled reactions: one energising reaction, which energises myosin heads by coupled ATP splitting, and one de-energising reaction, which transduces free energy from myosin heads to coupled actin movement. The whole cycle of myosin heads via cross-bridge formation and dissociation proceeds at zero resistance. Dissipation of free energy from coupled reactions occurs whenever the input potential overcomes the counteracting output potential. In addition, dissipation is produced by uncoupling. This is brought about by a load dependent shortening of the cross-bridge stroke to zero, which allows isometric force generation without mechanical power output. The occurrence of maximal efficiency is caused by uncoupling. Under coupled conditions, Hill’s equation (velocity as a function of load) is fulfilled. In addition, force and shortening velocity both depend on [Ca2+]. Muscular fatigue is triggered when ATP consumption overcomes ATP delivery. As a result, the substrate of the cycle, [MgATP2?], is reduced. This leads to a switch off of cycling and ATP consumption, so that a recovery of [ATP] is possible. In this way a potentially harmful, persistent low energy state of the cell can be avoided. PMID:24957757

Diederichs, Frank

2012-01-01

182

Theory and design of an Annual Cycle Energy System (ACES) for residences  

NASA Astrophysics Data System (ADS)

The basic concept of the Annual Cycle Energy System (ACES), and integrated system for supplying space heating, hot water, and air conditioning to a building, and the theory underlying its design and operation are described. Practical procedures for designing an ACES for a single family residence, together with recommended guidelines for the construction and installation of system components, are presented. Methods are discussed for estimating the life cycle cost, component sizes, and annual energy consumption of the system for residential applications in different climatic regions of the US.

Nephew, E. A.; Abbatiello, L. A.; Ballou, M. L.

1980-05-01

183

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

184

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

PubMed

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

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

2013-04-01

185

Reducing Life Cycle Cost By Energy Saving in Pump Systems  

E-print Network

will be larger to cover the end of curve run out condition. The motor will run at partial load and be less efficient as well as increasing the purchase price and placement cost. A "good" efficiency for a pump will vary from 90% down to 40% or possibly lower... to system demand. AUXILIARY SERVICES Auxiliary services; cooling, heating, quench liquids barrier fluids, etc. are often essential for the safe and reliable operation of the pump, but the energy costs associated with them can be substantial. Ways...

Bower, J. R.

186

Light harvesting, energy transfer and electron cycling of a native photosynthetic membrane adsorbed onto a gold surface.  

PubMed

Photosynthetic membranes comprise a network of light harvesting and reaction center pigment-protein complexes responsible for the primary photoconversion reactions: light absorption, energy transfer and electron cycling. The structural organization of membranes of the purple bacterial species Rb. sphaeroides has been elucidated in most detail by means of polarized light spectroscopy and atomic force microscopy. Here we report a functional characterization of native and untreated membranes of the same species adsorbed onto a gold surface. Employing fluorescence confocal spectroscopy and light-induced electrochemistry we show that adsorbed membranes maintain their energy and electron transferring functionality. Gold-adsorbed membranes are shown to generate a steady high photocurrent of 10 microA/cm(2) for several minutes and to maintain activity for up to three days while continuously illuminated. The surface-adsorbed membranes exhibit a remarkable functionality under aerobic conditions, even when exposed to light intensities well above that of direct solar irradiation. The component at the interface of light harvesting and electron cycling, the LH1 complex, displays exceptional stability, likely contributing to the robustness of the membranes. Peripheral light harvesting LH2 complexes show a light intensity dependent decoupling from photoconversion. LH2 can act as a reversible switch at low-light, an increased emitter at medium light and photobleaches at high light. PMID:20036635

Magis, Gerhard J; den Hollander, Mart-Jan; Onderwaater, Willem G; Olsen, John D; Hunter, C Neil; Aartsma, Thijs J; Frese, Raoul N

2010-03-01

187

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

Code of Federal Regulations, 2011 CFR

...Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES GENERAL POLICY AND INTERPRETATIONS...Public Utility Regulatory Policies Act of 1978 § 2.400...natural gas as the primary energy source for...

2011-04-01

188

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

189

Energy flow and nutrient cycling in salamander populations in the Hubbard Brook Experimental Forest, New Hampshire  

Microsoft Academic Search

Energy flow through salamander populations in the Hubbard Brook Ecosystem is about 11,000 kcal\\/ha yr (=46,000 kJ\\/ha yr). This is approx. = 0.02% of the net primary productivity, and is approx. = 20% of the energy flow through bird and mammal populations. Salamanders are efficient (60%) at converting ingested energy into new tissue and produce more new tissue annually than

T. M. Burton; G. E. Likens

1975-01-01

190

Scatter correction method with primary modulator for dual energy digital radiography: a preliminary study  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

191

Accounting for the energies and entropies of kinesin's catalytic cycle  

NASA Astrophysics Data System (ADS)

When the processive motor protein kinesin walks along the biopolymer microtubule it can occasionally make a backward step. Recent single molecule experiments on moving kinesin have revealed that the forward-to-backward step ratio decreases exponentially with the load force. Carter and Cross (Nature 435, 308-312, 2005) found that this ratio tightly followed 802 × exp[-0.95 F], where F is the load force in piconewtons. A straightforward analysis of a Brownian step leads to L/(2 k B T) as the factor in front of the load force, where L is the 8 nm stepsize, k B is the Boltzmann constant, and T is the temperature. The factor L/(2 k B T) does indeed equal 0.95 pN-1. The same analysis shows how the 802 prefactor derives from the power stroke energy G as exp[ G/(2 k B T)]. There are indications that the power stroke derives from the entropically driven coiling of the 30 amino acid neck linker that connects the two kinesin heads. This idea is examined and consequences are deduced.

Bier, M.

2008-10-01

192

Differences in expression of proliferation-associated genes and RANKL across the menstrual cycle in estrogen receptor-positive primary breast cancer.  

PubMed

The purpose of this study is to determine if there are differences in the expression of estrogen-regulated genes (ERGs), proliferation-associated genes and the progesterone effector RANKL, in premenopausal ER+ breast cancer as a result of the major changes in hormone levels that occur through the menstrual cycle. Primary ER+ tumours from 174 patients were assigned to one of three menstrual cycle windows: W1 (days 27-35 + 1-6), W2 (days 7-16) and W3 (days 17-26). RNA expression of 42 genes, including 24 putative genes associated with plasma E2 levels, seven proliferation genes and RANKL was measured. Expression of PGR, TFF1, GREB1 and PDZK1 followed the previously reported pattern: a higher level in W2 compared to W1 while W3 had an intermediate value, mirroring changes in plasma estradiol. Of the other 20 ERGs, four (RUNX1, AGR2, SERPINA3 and SERPINA5) showed significant differences (p = 0.009-0.049) in expression across the menstrual cycle. The expression of six of seven proliferation-associated genes varied across the cycle but differently from the ERGs, being 20-35 % lower in W3 compared to W1 and W2 (p = 0.004-0.031). Expression of RANKL was 2.5 to 3-fold highest in W3 (p = 0.0001) and negatively correlated to the expression of the proliferation-associated genes (r = -0.37; p < 0.0001). Expression of proliferation-associated genes and RANKL in ER+ breast tumours varies across the menstrual cycle showing a different rhythm to that of ERGs. This may affect the interpretation of gene expression profiles but may be exploitable as an endogenous test of endocrine responsiveness. PMID:25367875

Haynes, Ben P; Viale, Giuseppe; Galimberti, Viviana; Rotmensz, Nicole; Gibelli, Bianca; Smith, Ian E; Dowsett, Mitch

2014-11-01

193

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

194

Theory and design of an Annual Cycle Energy System (ACES) for residences  

Microsoft Academic Search

The basic concept of the Annual Cycle Energy System (ACES), and integrated system for supplying space heating, hot water, and air conditioning to a building, and the theory underlying its design and operation are described. Practical procedures for designing an ACES for a single family residence, together with recommended guidelines for the construction and installation of system components, are presented.

E. A. Nephew; L. A. Abbatiello; M. L. Ballou

1980-01-01

195

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

196

Optimal household refrigerator replacement policy for life cycle energy, greenhouse gas emissions, and cost  

Microsoft Academic Search

Although the last decade witnessed dramatic progress in refrigerator efficiencies, inefficient, outdated refrigerators are still in operation, sometimes consuming more than twice as much electricity per year compared with modern, efficient models. Replacing old refrigerators before their designed lifetime could be a useful policy to conserve electric energy and greenhouse gas emissions. However, from a life cycle perspective, product replacement

Hyung Chul Kim; Gregory A. Keoleian; Yuhta A. Horie

2006-01-01

197

Annual cycle of energy balance of Zongo Glacier, Cordillera Real, Bolivia  

Microsoft Academic Search

An 18-month meteorological data set recorded at 5150 m above sea level (asl) on Zongo Glacier, in the tropical Andes of Bolivia, is used to derive the annual cycle of the local energy balance and to compare it to the local mass balance. The roughness parameters needed to calculate the turbulent fluxes over the surface are deduced from direct sublimation

Patrick Wagnon; Pierre Ribstein; Bernard Francou; Bernard Pouyaud

1999-01-01

198

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

Microsoft Academic Search

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

Márcio de Almeida D’Agosto; Suzana Kahn Ribeiro

2009-01-01

199

Technology for Brayton-cycle powerplants using solar and nuclear energy  

Microsoft Academic Search

Brayton cycle gas turbines have the potential to use either solar heat or nuclear reactors for generating from tens of kilowatts to tens of megawatts of power in space, all this from a single technology for the power generating system. Their development for solar energy dynamic power generation for the space station could be the first step in an evolution

1986-01-01

200

Adaptive GPS Duty Cycling and Radio Ranging for Energy-efficient Localization  

E-print Network

Adaptive GPS Duty Cycling and Radio Ranging for Energy-efficient Localization Raja Jurdak CSIRO ICT and localization performance in a mobile sensor network application. The focus is on augmenting GPS loca- tion node lifetime. We use empirical GPS and radio contact data from a large- scale animal tracking

Paris-Sud XI, Université de

201

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

202

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

203

Seasonal cycles of Antarctic surface energy balance from automatic weather stations  

Microsoft Academic Search

We present the seasonal cycle of the Antarctic surface energy balance (SEB) using 4 years (1998 2001) of automatic weather station (AWS) data. The four AWSs are situated on an ice shelf, in the coastal and inland katabatic wind zone and the interior plateau of Dronning Maud Land. To calculate surface temperature we use a SEB closure assumption for a

Michiel van den Broeke; Carleen Reijmer; Dirk van As; Roderik van de Wal; J. Oerlemans

2005-01-01

204

Seasonal cycles of Antarctic surface energy balance from automatic weather stations  

Microsoft Academic Search

We present the seasonal cycle of the Antarctic surface energy balance (SEB) using 4 years (1998-2001) of automatic weather station (AWS) data. The four AWSs are situated on an ice shelf, in the coastal and inland katabatic wind zone and the interior plateau of Dronning Maud Land. To calculate surface temperature we use a SEB closure assumption for a surface

Michiel Van den Broeke; Carleen Reijmer; As van Dirk; Roderik Van de Wal; J. Oerlemans

2005-01-01

205

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

Microsoft Academic Search

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

Varun; Ravi Prakash; I. K. Bhat

2010-01-01

206

Annual cycle energy system (ACES). Performance report, November 1977September 1978  

Microsoft Academic Search

A single-family residence near Knoxville, Tennessee, is being used to demonstrate the energy-conserving features of the annual cycle energy system (ACES), an integrated heating and cooling system that utilizes a unidirectional heat pump and low-temperature thermal storage. A second house, the control house, is being used to compare the performance of the ACES with that of an electric-resistance heating and

A. S. Holman; L. A. Abbatiello

1980-01-01

207

A performance and economic evaluation of annual cycle energy storage \\/ACES  

Microsoft Academic Search

The performance of a residential annual energy storage scheme utilizing ice storage and a three-coil heat pump is evaluated for a range of climates and storage sizes. Comparisons are made with conventional electric resistance heat with central air conditioning or an electric air-to-air heat pump. Economic evaluations are made with payback and with present value life-cycle costing. Annual energy storage

R. S. Miller

1980-01-01

208

A performance and economic evaluation of annual cycle energy storage /ACES/  

NASA Astrophysics Data System (ADS)

The performance of a residential annual energy storage scheme utilizing ice storage and a three-coil heat pump is evaluated for a range of climates and storage sizes. Comparisons are made with conventional electric resistance heat with central air conditioning or an electric air-to-air heat pump. Economic evaluations are made with payback and with present value life-cycle costing. Annual energy storage is found to be uneconomical.

Miller, R. S.

1980-02-01

209

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

Microsoft Academic Search

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

C. Saricks; D. Santini; M. Wang

1999-01-01

210

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

211

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

Microsoft Academic Search

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

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

2010-01-01

212

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

SciTech Connect

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

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

2009-07-01

213

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

Microsoft Academic Search

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

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

2011-01-01

214

Ice and water: annual cycle energy system offers savings in heating, cooling. [Potential of 70 percent savings in energy  

Microsoft Academic Search

The annual cycle energy system (ACES) offers an inexpensive means of providing heat from the latent heat of fusion of water. Heat is obtained by freezing water to remove the heat of fusion (144 Btu\\/lb). The heat thus obtained is pumped by a one-direction heat pump to deliver heat to the building. The ice frozen during the heating season is

1976-01-01

215

Hydrodynamics of a new concept of primary containment by energy absorption  

NASA Technical Reports Server (NTRS)

Fluid dynamical analysis for idealized reactors system with spherical symmetry determines the effect which the destructive component of a nuclear accident produces on primary containment structures. Steel strands surrounding the reactor cavity in the biological shield exhibit plastic deformation to achieve the energy absorption.

Fistedis, S. H.; Sorensen, H. C.

1969-01-01

216

An equilibrium zonal energy balance climate model that incorporates a global carbon cycle  

NASA Astrophysics Data System (ADS)

We have combined a global carbon cycle with a zonally averaged energy balance climate model, and examined how this interacts with the ice-albedo feedback to change the possible steady state solutions. The introduction of the global carbon cycle reduces the range of insolation values over which stable partial ice-cover solutions exists. The results also suggest that the effect of increasing the total carbon in the system (as would happen in fossil fuel burning scenarios) is to decrease, or eliminate, the safety margin that separates us from an ice-free world.

Huntingford, C.; Hargreaves, J. C.; Lenton, T. M.; Annan, J. D.

2003-04-01

217

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

218

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

E-print Network

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

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

2014-03-13

219

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

220

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

E-print Network

to complete one cycle. The frequency of light refers to the number of cycles in one second. Low-energy light a small portion of the light encountered in every day life. Low energy radio, TV, and microwave signals The light emitted by a lightbulb or a star is formed from a continuum of different wavelengths. But how

Zworski, Maciej

221

Energy and Nutrient Intakes during Different Phases of the Menstrual Cycle in Females in the United Arab Emirates  

Microsoft Academic Search

Background\\/Aims: Evidence related to the influence of the menstrual cycle on energy and nutrient intakes is inconclusive. The purpose of the present study was to investigate energy and nutrient intakes during different phases of the menstrual cycle in adult females in the United Arab Emirates. Methods: Forty-three females, aged between 18 and 30 years, were recruited to the study. Subjects

Leila I. Cheikh Ismail; Huda Al-Hourani; Helen J. Lightowler; Ayesha S. Aldhaheri; C. Jeya K. Henry

2009-01-01

222

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

223

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

224

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

225

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

SciTech Connect

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

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

2008-01-01

226

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

PubMed

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

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

2013-10-01

227

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

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

228

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

229

MY NASA DATA Lesson Plan: Earth's Energy Budget-Seasonal Cycles in Net Radiative Flux  

NSDL National Science Digital Library

This lesson plan uses Clouds and Earth's Radiant Energy System (CERES) radiation data to understand seasonal variations in the pattern of net energy input to the Earth system. The net amount of energy received by different parts of the Earth at different times of year determines the type of weather and climate they will experience. The net radiative flux shows the combined effect of the Sun's location and the conditions in the Earth system. The two primary components of the Earth system that affect the net radiative flux are: 1) the type of surface and 2) clouds. This lesson will allow students to explore these variations.

2006-01-01

230

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

2013-10-01

231

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

PubMed

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

Zhang, Chao; Anadon, Laura Diaz

2013-12-17

232

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

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

233

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

234

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

Microsoft Academic Search

Brayton-cycle gas turbines have the potential to use either solar heat or nuclear reactors to generate from tens of kilowatts to tens of megawatts of power in space, all this from a single technology for the power-generating system. Their development for solar-energy dynamic power generation for the space station could be the first step in an evolution of such powerplants

1986-01-01

235

Energy and environmental analysis of the lead--acid battery life cycle. Final report  

Microsoft Academic Search

The lead-acid battery is evaluated to determine its life cycle energy and environmental impacts when applied to the electric-utility load-leveling mission. A ''traction'' type battery cell, the C and D model C75-15, was selected as representative of the typical industrial lead--acid storage battery. At the present time, this is the closest type of battery in life and performance characteristics to

C. Lee; M. Mendis; D. Sullivan

1978-01-01

236

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

237

Antenna entropy in plant photosystems does not reduce the free energy for primary charge separation.  

PubMed

We have investigated the concept of the so-called "antenna entropy" of higher plant photosystems. Several interesting points emerge: 1. In the case of a photosystemwhich harbours an excited state, the “antenna entropy” is equivalent to the configurational (mixing) entropy of a thermodynamic canonical ensemble. The energy associated with this parameter has been calculated for a hypothetical isoenergetic photosystem, photosystem I and photosystem II, and comes out in the range of 3.5 - 8% of the photon energy considering 680 nm. 2. The “antenna entropy” seems to be a rather unique thermodynamic phenomenon, in as much as it does not modify the free energy available for primary photochemistry, as has been previously suggested. 3. It is underlined that this configurational (mixing) entropy, unlike heat dispersal in a thermal system, does not involve energy dilution. This points out an important difference between thermal and electronic energy dispersal. PMID:25190479

Jennings, Robert C; Zucchelli, Giuseppe

2014-12-01

238

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

239

Thermal energy storage for organic Rankine cycle solar dynamic space power systems  

NASA Astrophysics Data System (ADS)

An organic Rankine cycle-solar dynamic power system (ORC-SDPS) comprises a concentrator, a radiator, a power conversion unit, and a receiver with a thermal energy storage (TES) subsystem which charges and discharges energy to meet power demands during orbital insolation and eclipse periods. Attention is presently given to the criteria used in designing and evaluating an ORC-SDPS TES, as well as the automated test facility employed. It is found that a substantial data base exists for the design of an ORC-SDPS TES subsystem.

Heidenreich, G. R.; Parekh, M. B.

240

Energy impacts of controlling carbon dioxide emissions from an integrated gasification/combined-cycle system  

SciTech Connect

This paper presents results from a study of the impacts associated with CO{sub 2} recovery in integrated gasification/combined-cycle (IGCC) systems which is being conducted for the Morgantown Energy Technology Center by Argonne National Laboratory. The objective of the study is to compare, on a consistent systems-oriented basis, the energy and economic impacts of adding CO{sub 2} capture and sequestration to an IGCC system. The research reported here has emphasized commercial technologies for capturing CO{sub 2}, but ongoing work is also addressing advanced technologies under development and alternate power-system configurations that may enhance system efficiency.

Livengood, C.D.; Doctor, R.D.; Molburg, J.C.; Thimmapuram, P.

1994-08-01

241

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

242

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

NASA Technical Reports Server (NTRS)

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

Juhasz, Albert J.; Sawicki, Jerzy T.

2003-01-01

243

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

PubMed

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

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

2014-01-01

244

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

Microsoft Academic Search

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

Deniz Karman

2011-01-01

245

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

Microsoft Academic Search

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 ~50 TeV and several thousand TeV. Experimental data are compared with the expected rates from two composition models: a

S. Ahlen; M. Ambrosio; R. Antolini; G. Auriemma; A. Baldini; B. B. Bam; G.C. Barbarino; B.C. Barish; G. Battistoni; R. Bellotti; C. Bemporad; P. Bernardini; H. Bilokon; V. Bisi; C. Bloise; S. Bussino; F. Cafagna; M. Calicchio; P. Campana; D. Campana; M. Carboni; S. Cecchini; F. Cei; V. Chiarella; C. Chiera; A. Cobis; R. Cormack; A. Corona; S. Coutu; G. Decataldo; C. Demarzo; M. De Vincenzi; A. Di Credico; E. Diehl; O. Erriquez; C. Favuzzi; D. Ficenec; C. Forti; L. Foti; P. Fusco; G. Giacomelli; G. Giannini; N. Giglietto; P. Giubellino; M. Grassi; P. Green; A. Grillo; F. Guarino; C. Gustavino; A. Habig; R. Heinz; J.T. Hong; E. Iarocci; E. Katsavounidis; E. Kearns; S. Klein; S. Kyriazopoulou; E. Lamanna; C. Lane; D. Levin; P. Lipari; G. Liu; R. Liu; M. Longo; G. Ludlam; G. Mancarella; A. Margiotta-Neri; A. Margiotta-Neri; A. Marin; D. Martello; G. Martellotti; A. Chiesa; M. Masera; P. Matteuzzi; D. Michael; L. Miller; P. Monacelli; M. Monteno; S. Mufson; J. Musser; S. Nutter; C. Okada; G. Osteria; O. Palamara; S. Parlati; V. Patera; L. Patrizii; R. Pazzi; C. Peck; J. Petrakis; S. Petrera; N. Pignatano; P. Pistilli; F. Predieri; L. Ramello; J. Reynoldson; F. Ronga; G. Rosa; C. Satriano; L. Satta; E. Scapparone; K. Scholberg; A. Sciubba; P. Lugaresi; M. Severi; M. Severi; P. Spinelli; M. Spinetti; M. Spinetti; J. Steele; R. Steinberg; J. Stone; J. L. Stone; A. Surdo; G. Tarlé; V. Valente; G. Verdone; C. Walter; R. Webb; C. W. Walter

1992-01-01

246

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

247

Technology for Bayton-cycle powerplants using solar and nuclear energy  

NASA Technical Reports Server (NTRS)

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

English, R. E.

1986-01-01

248

The energy dependence of the ratios of secondary to primary elements in the cosmic radiation  

NASA Technical Reports Server (NTRS)

The secondary to primary ratios B/C, N/O and (Sc-Mn)/Fe in the galactic cosmic rays have been measured in the overall energy interval 30-180 MeV/n with the University of Chicago cosmic ray telescope on board the satellite IMP-8 during the period 1974-1978. These results, together with the values of the same ratios measured at higher energies, have been compared to the results of cosmic ray propagation calculations using different pathlength distributions (PLD) and different levels of solar modulation, in order to select a single set of parameters consistent with all the measured ratios.

Garcia-Munoz, M.; Margolis, S. H.; Simpson, J. A.; Wefel, J. P.

1980-01-01

249

Primary electron energy dependent flashover in surface polarity on Au films  

NASA Astrophysics Data System (ADS)

Primary electron energy (Ep) dependent change in target current was studied on a grounded Au film in the range of 40 to 3500 eV. The current jumped suddenly from a negative to a positive value at ˜650 eV with increasing Ep, while it disappeared in reverse sweep and with increasing substrate temperature. Detailed analysis suggests that Ep dependent surface charging plays a pivotal role in flashover. Prior to critical Ep in the forward sweep, a gradual shift of a double peak-like structure towards high kinetic energy region in the secondary electron spectra also confirms surface charging effect.

Catalfano, M.; Kanjilal, A.; Al-Ajlony, A.; Harilal, S. S.; Hassanein, A.

2013-05-01

250

Proton and helium energy spectra above 1 TeV for primary cosmic rays  

SciTech Connect

Energy spectra of protons and helium nuclei in the primary cosmic rays were measured above 1 TeV in a series of balloon flights of emulsion chambers. Differential spectra may be represented by power laws of indices -2.81 +- 0.13 and -2.83 +- 0.20 for protons and He, respectively. No index change was observed for either species over the energy ranges 5--500 TeV for protons and 2--50 TeV/nucleon for He. Intensities were consistent with extrapolations of previously published data below 1 TeV/nucleon.

Burnett, T.H.; Dake, S.; Fuki, M.; Gregory, J.C.; Hayashi, T.; Holynski, R.; Huggett, R.W.; Hunter, S.D.; Iwai, J.; Jones, W.V.

1983-09-12

251

Photon and helium energy spectra above 1 TeV for primary cosmic rays  

NASA Technical Reports Server (NTRS)

Energy spectra of protons and helium nuclei in primary cosmic rays were measured above 1 TeV in a series of balloon flights carrying emulsion chambers. Differential spectra may be represented by power laws of indices -2.81 + or - 0.13 and -2.83 + or - 0.20 for protons and He, respectively. No index change was observed for either species over the energy ranges 5-500 TeV for protons and 2-50 TeV/nucleon for He. Intensities were consistent with extrapolations of previously published data below 1 TeV/nucleon.

Burnett, T. H.; Dake, S.; Fuki, M.; Gregory, J. C.; Hayashi, T.; Holynski, R.; Huggett, R. W.; Hunter, S. D.; Iwai, J.; Jones, W. V.

1983-01-01

252

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

ERIC Educational Resources Information Center

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

Iowa State Dept. of Education, Des Moines.

253

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

ERIC Educational Resources Information Center

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

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

254

Methods of Determination of the Energy and Mass of Primary Cosmic Ray Particles at Extensive Air Shower Energies  

E-print Network

Measurements of cosmic ray particles at energies above E = 5 x 10^{14} eV are performed by large area ground based air shower experiments. Only they provide the collection power required for obtaining sufficient statistics at the low flux levels involved. In this review we briefly outline the physics and astrophysics interests of such measurements and discuss in more detail various experimental techniques applied for reconstructing the energy and mass of the primary particles. These include surface arrays of particle detectors as well as observations of Cherenkov- and of fluorescence light. A large variety of air shower observables is then reconstructed from such data and used to infer the properties of the primary particles via comparisons to air shower simulations. Advantages, limitations, and systematic uncertainties of different approaches will be critically discussed.

Karl-Heinz Kampert

2001-01-17

255

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

ERIC Educational Resources Information Center

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

Krauskopf, Sara

2010-01-01

256

Fuel-Cycle Fossil Energy Use and Greenhouse Gas Emissions of Fuel Ethanol Produced from U.S. Midwest Corn  

E-print Network

#12;Fuel-Cycle Fossil Energy Use and Greenhouse Gas Emissions of Fuel Ethanol Produced from U on a mass emission per travel mile basis, the corn-to-ethanol fuel cycle for Midwest-produced ethanol% of total domestic ethanol production. That is, while the model still covers all alternative fuels and five

Patzek, Tadeusz W.

257

Thermal design of a solar hydrogen plant with a copper–chlorine cycle and molten salt energy storage  

Microsoft Academic Search

In this paper, the operating temperature ranges of various solar thermal energy technologies are analyzed, with respect to their compatibility with solar hydrogen production via thermochemical cycles. It is found that the maximum temperature of 530°C required by the oxygen production step in the Cu–Cl cycle can be supplied by current solar thermal technologies. The heat requirements are examined for

Z. Wang; G. F. Naterer; K. S. Gabriel; E. Secnik; R. Gravelsins; V. Daggupati

2011-01-01

258

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

259

Life-cycle-assessment of fuel-cells-based landfill-gas energy conversion technologies  

NASA Astrophysics Data System (ADS)

Landfill-gas (LFG) is produced as result of the biological reaction of municipal solid waste (MSW). This gas contains about 50% of methane, therefore it cannot be released into the atmosphere as it is because of its greenhouse effect consequences. The high percentage of methane encouraged researchers to find solutions to recover the related energy content for electric energy production. The most common technologies used at the present time are internal combustion reciprocating engines and gas turbines. High conversion efficiency guaranteed by fuel cells (FCs) enable to enhance the energy recovery process and to reduce emissions to air, such as NO x and CO. In any case, in order to investigate the environmental advantages associated with the electric energy generation using fuel cells, it is imperative to consider the whole "life cycle" of the system, "from cradle-to-grave". In fact, fuel cells are considered to be zero-emission devices, but, for example, emissions associated with their manufacture or for hydrogen production must be considered in order to evaluate all impacts on the environment. In the present work a molten carbonate fuel cell (MCFC) system for LFG recovery is considered and a life cycle assessment (LCA) is conducted for an evaluation of environmental consequences and to provide a guide for further environmental impact reduction.

Lunghi, P.; Bove, R.; Desideri, U.

260

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

261

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

E-print Network

. This work reports on a test at ARI conditions (95 deg. F outside, 80 deg F, 51% RH inside). The test unit (10 year old, 5 ton Bryant Air Conditioner) without the Cromer cycle, averaged an EER of 7.93 at a latent ratio of 26.2 % (SHR = 0.738). With the Cromer...

Cromer, C. J.

2000-01-01

262

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

263

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

264

Carbon capture and utilization: Preliminary life cycle CO 2, energy, and cost results of potential mineral carbonation  

Microsoft Academic Search

Mineral carbonation has been identified as a potentially suitable means of CO2 sequestration in Singapore due to the nation’s lack of land for geological or deep ocean storage of CO2. In this article, the total energy, CO2 emissions and costs of mineral carbonation are investigated using a life cycle assessment (LCA) approach. The life cycle investigation took into account energy

H. H. Khoo; J. Bu; R. L. Wong; S. Y. Kuan; P. N. Sharratt

2011-01-01

265

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

266

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

NASA Astrophysics Data System (ADS)

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

Shen, B.-W.

2014-04-01

267

Energy metabolism and glutamate-glutamine cycle in the brain: a stoichiometric modeling perspective  

PubMed Central

Background The energetics of cerebral activity critically relies on the functional and metabolic interactions between neurons and astrocytes. Important open questions include the relation between neuronal versus astrocytic energy demand, glucose uptake and intercellular lactate transfer, as well as their dependence on the level of activity. Results We have developed a large-scale, constraint-based network model of the metabolic partnership between astrocytes and glutamatergic neurons that allows for a quantitative appraisal of the extent to which stoichiometry alone drives the energetics of the system. We find that the velocity of the glutamate-glutamine cycle (Vcyc) explains part of the uncoupling between glucose and oxygen utilization at increasing Vcyc levels. Thus, we are able to characterize different activation states in terms of the tissue oxygen-glucose index (OGI). Calculations show that glucose is taken up and metabolized according to cellular energy requirements, and that partitioning of the sugar between different cell types is not significantly affected by Vcyc. Furthermore, both the direction and magnitude of the lactate shuttle between neurons and astrocytes turn out to depend on the relative cell glucose uptake while being roughly independent of Vcyc. Conclusions These findings suggest that, in absence of ad hoc activity-related constraints on neuronal and astrocytic metabolism, the glutamate-glutamine cycle does not control the relative energy demand of neurons and astrocytes, and hence their glucose uptake and lactate exchange. PMID:24112710

2013-01-01

268

Rock Cycle: Cycling  

NSDL National Science Digital Library

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

National Science Teachers Association (NSTA)

2006-11-01

269

Solar energy system for heating and cooling of buildings utilizing moist air cycles  

SciTech Connect

An integrated system is presented for the collection, storage, and utilization of solar energy in the heating and cooling of buildings utilizing a moist air cycle involving evaporation and condensation of water vapor at constant pressure to obtain the advantages of high heat capacity, resulting from phase change, and low mass flow rate. Subersaturated moist air is circulated through solar collectors where evaporation takes place; the coolant leaving the solar collectors in a saturated condition and returning to a hot storage tank. There the coolant flows across the surface of hot stored water where condensation takes place, and thereafter leaves the hot storage tank in a saturated condition and at a temperature only slightly above that of the stored water. The hot storage tank further includes floating heat exchanger means for heating water in the portable water supply system. Upon leaving the hot storage tank the coolant is passed through a novel humidifying device which restores exactly the amount of moisture that was lost by condensation. This device withdraws water from the hot storage tank by means of a pump and introduces the water into the moist air stream in the form of a fog and very fine mist by the process of high pressure atomization. The supersaturated mixture is then returned to the solar collectors to repeat the cycle. Suitable controls modulate both the air and water flow rates in response to the rate at which solar energy is being collected. The system also includes means for using the solar equipment at night to dissipate thermal energy with the moist air cycle and thus chill water in a second tank to create a heat sink. Another salient feature of this system is means for heating and cooling a space or a building by circulating conditioned air through building cavities, creating a thermal envelope and utilizing the radiant effect of large surfaces such as walls and/or ceilings and floors to heat and cool the space.

Holbrook, E.M.; Wallace, J.J.

1980-01-08

270

Effects of 5-fluorouracil in nuclear and cellular morphology, proliferation, cell cycle, apoptosis, cytoskeletal and caveolar distribution in primary cultures of smooth muscle cells.  

PubMed

Colon cancer is one of the most prevalent types of cancer in the world and is one of the leading causes of cancer death. The anti-metabolite 5- fluorouracil (5-FU) is widely used in the treatment of patients with colon cancer and other cancer types. 5-FU-based chemotherapy has been shown to be very efficient in the improvement of overall survival of the patients and for the eradication of the disease. Unfortunately, common side effects of 5-FU include severe alterations in the motility of the gastrointestinal tissues. Nevertheless, the molecular and cellular effects of 5-FU in smooth muscle cells are poorly understood. Primary smooth muscle cell cultures are an important tool for studies of the biological consequences of 5-FU at the cellular level. The avian gizzard is one of the most robust organs of smooth muscle cells. Here we studied the molecular and cellular effects of the chemotherapic drug 5-FU in a primary culture of chick gizzard smooth muscle cells. We found that treatment of smooth muscle cells with 5-FU inhibits cell proliferation by the arrest of cells in the G1 phase of cell cycle and induce apoptosis. 5-FU induced a decrease in the percentage of histone H3-positive cells. Treatment of cells with 5-FU induced changes in cellular and nuclear morphology, a decrease in the number of stress fibers and a major decrease in the number of caveolin-3 positive cells. Our results suggest that the disorganization of the actin cytoskeleton and the reduction of caveolin-3 expression could explain the alterations in contractility observed in patients treated with 5-FU. These findings might have an impact in the understanding of the cellular effects of 5-FU in smooth muscle tissues and might help the improvement of new therapeutic protocols for the treatment of colon cancer. PMID:23646193

Filgueiras, Marcelo de Carvalho; Morrot, Alexandre; Soares, Pedro Marcos Gomes; Costa, Manoel Luis; Mermelstein, Cláudia

2013-01-01

271

Effects of 5-Fluorouracil in Nuclear and Cellular Morphology, Proliferation, Cell Cycle, Apoptosis, Cytoskeletal and Caveolar Distribution in Primary Cultures of Smooth Muscle Cells  

PubMed Central

Colon cancer is one of the most prevalent types of cancer in the world and is one of the leading causes of cancer death. The anti-metabolite 5- fluorouracil (5-FU) is widely used in the treatment of patients with colon cancer and other cancer types. 5-FU-based chemotherapy has been shown to be very efficient in the improvement of overall survival of the patients and for the eradication of the disease. Unfortunately, common side effects of 5-FU include severe alterations in the motility of the gastrointestinal tissues. Nevertheless, the molecular and cellular effects of 5-FU in smooth muscle cells are poorly understood. Primary smooth muscle cell cultures are an important tool for studies of the biological consequences of 5-FU at the cellular level. The avian gizzard is one of the most robust organs of smooth muscle cells. Here we studied the molecular and cellular effects of the chemotherapic drug 5-FU in a primary culture of chick gizzard smooth muscle cells. We found that treatment of smooth muscle cells with 5-FU inhibits cell proliferation by the arrest of cells in the G1 phase of cell cycle and induce apoptosis. 5-FU induced a decrease in the percentage of histone H3-positive cells. Treatment of cells with 5-FU induced changes in cellular and nuclear morphology, a decrease in the number of stress fibers and a major decrease in the number of caveolin-3 positive cells. Our results suggest that the disorganization of the actin cytoskeleton and the reduction of caveolin-3 expression could explain the alterations in contractility observed in patients treated with 5-FU. These findings might have an impact in the understanding of the cellular effects of 5-FU in smooth muscle tissues and might help the improvement of new therapeutic protocols for the treatment of colon cancer. PMID:23646193

Filgueiras, Marcelo de Carvalho; Morrot, Alexandre; Soares, Pedro Marcos Gomes; Costa, Manoel Luis; Mermelstein, Claudia

2013-01-01

272

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

NASA Technical Reports Server (NTRS)

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

Berry, Linda R.

2002-01-01

273

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

274

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

275

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

276

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

NASA Astrophysics Data System (ADS)

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

Becker, Erich; Knoepfel, Rahel

2014-05-01

277

Experimental Investigation of the Nature of the Knee in the Primary Cosmic Ray Energy Spectrum with the GAMMA experiment  

E-print Network

We present preliminary results obtained by a novel difference method for the study of the nature of the knee in the energy spectrum of the primary cosmic radiation. We have applied this method to data from the GAMMA experiment in Armenia. The analysis provides evidence for the possible existence of a nearby source of primary cosmic rays in the Southern hemisphere.

Pavlyuchenko, V P; Nikolskaya, N M; Erlykin, A D; Babayan, H A; Garyaka, A P; Vardanyan, H S; Jones, L W; Kempa, J; Pattison, B; Procureur, J

2014-01-01

278

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

279

Systems analysis techniques for annual cycle thermal energy storage solar systems  

SciTech Connect

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

Baylin, F.; Sillman, S.

1980-07-01

280

Energy metabolism and glutamate-glutamine cycle in the brain: a stoichiometric modeling perspective  

E-print Network

The energetics of cerebral activity critically relies on the functional and metabolic interactions between neurons and astrocytes. Important open questions include the relation between neuronal versus astrocytic energy demand, glucose uptake and intercellular lactate transfer, as well as their dependence on the level of activity. We have developed a large-scale, constraint-based network model of the metabolic partnership between astrocytes and glutamatergic neurons that allows for a quantitative appraisal of the extent to which stoichiometry alone drives the energetics of the system. We find that the velocity of the glutamate-glutamine cycle ($V_{cyc}$) explains part of the uncoupling between glucose and oxygen utilization at increasing $V_{cyc}$ levels. Thus, we are able to characterize different activation states in terms of the tissue oxygen-glucose index (OGI). Calculations show that glucose is taken up and metabolized according to cellular energy requirements, and that partitioning of the sugar between d...

Massucci, Francesco Alessandro; Giove, Federico; Maraviglia, Bruno; Castillo, Isaac Perez; Marinari, Enzo; De Martino, Andrea

2013-01-01

281

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

E-print Network

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

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

2014-01-01

282

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

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

283

Solar energy system for heating and cooling of buildings utilizing moist air cycles  

SciTech Connect

An integrated system for the collection, storage, and utilization of solar energy in the heating and cooling of buildings utilizing a moist air cycle involving evaporation and condensation of water vapor at constant pressure to obtain the advantages of high heat capacity, resulting from phase change, and low mass flow rate. Supersaturated moist air is circulated through solar collectors where evaporation takes place; the coolant leaving the solar collectors in a saturated condition and returning to a hot storage tank. There the coolant flows across the surface of hot stored water where condensation takes place, and thereafter leaves the hot storage tank in a saturated condition and at a temperature only slightly above that of the stored water. The hot storage tank further includes floating heat exchanger means for heating water in the portable water supply system. Upon leaving the hot storage tank the coolant is passed through a novel humidifying device which restores exactly the amount of moisture that was lost by condensation. This device withdraws water from the hot storage tank by means of a pump and introduces the water into the moist air stream in the form of a fog and very fine mist by the process of high pressure atomization. The supersaturated mixture is then returned to the solar collectors to repeat the cycle. Suitable controls modulate both the air and water flow rates in response to the rate at which solar energy is being collected.

Holbrook, E.M.; Wallace, J.J.

1982-12-28

284

Life cycle energy and CO2 analysis of microalgae-to-biodiesel: preliminary results and comparisons.  

PubMed

Despite claims that microalgal biofuels are environmentally friendlier alternatives to conventional fuels, debate surrounding its ecological benefits or drawbacks still exists. LCA is used to analyze various biofuel production technologies from 'cradle to gate'. Energy and CO(2) balances are carried out for a hypothetical integrated PBR-raceway microalgae-to-biodiesel production in Singapore. Based on a functional unit of 1 MJ biofuel, the total energy demands are 4.44 MJ with 13% from biomass production, 85% from lipid extraction, and 2% from biodiesel production. Sensitivity analysis was carried out for adjustments in energy requirements, percentage lipid contents, and lower/higher heating product value. An 'Optimistic Case' was projected with estimates of: 45% lipid content; reduced energy needs for lipid extraction (1.3 MJ per MJ biodiesel); and heating value of biodiesel (42 MJ/kg). The life cycle energy requirements dropped significantly by about 60%. The results are compared with other published case studies from other countries. PMID:21435867

Khoo, H H; Sharratt, P N; Das, P; Balasubramanian, R K; Naraharisetti, P K; Shaik, S

2011-05-01

285

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

NASA Astrophysics Data System (ADS)

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

Waters, Daniel F.; Cadou, Christopher P.

2014-02-01

286

Heat recovery from a thermal energy storage based on the Ca(OH) 2\\/CaO cycle  

Microsoft Academic Search

Thermal energy storage is very important in many applications related to the use of waste heat from industrial processes, renewable energies or from other sources. Thermochemical storage is very interesting for long-term storage as it can be carried out at room temperature with no energy losses.Dehydration\\/hydration cycle of Ca(OH)2\\/CaO has been applied for thermal energy storage in two types of

M. N. Azpiazu; J. M. Morquillas; A. Vazquez

2003-01-01

287

Summary of annual cycle energy system workshop I held October 29--30, 1975, at Oak Ridge, Tennessee  

Microsoft Academic Search

The Annual Cycle Energy System (ACES) concept provides space heating, air conditioning, and water heating by means of a heat pump and an energy storage tank. Heat is removed in winter from the water in the tank and is added during the following summer. A workshop was held on October 29-30, 1975 in Oak Ridge, Tenn. to disseminate information on

H. C. Fischer; J. C. Moyers; E. C. Hise; E. A. Nephew

1976-01-01

288

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

289

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

290

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

291

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.

292

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

293

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

294

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

295

Importance of light scattering properties of cloud particles on calculating the earth energy cycle  

NASA Astrophysics Data System (ADS)

The Earth is an open system, and the energy cycle of the Earth is not always a certain amount. In other words, the energy cycle in the nature is imbalance. A better understanding of the earth energy cycle is very important to study global climate change. the IPCC-AR4 reported that the cloud in the atmosphere are still characterized by large uncertainties in the estimation of their effects on energy sysle of the Earth's atmosphere. There are two types of cloud in the atmosphere, which are Cirrus and warm water cloud. In order to strongly reflect visible wavelength from sun light, thick water cloud has the effect of cooling the earth surface. When Cirrus is compared to water cloud, temperature is almost lower. Thus, there is a feature that Cirrus is easy to absorb long-wave radiation than warm water cloud. However, in order to quantitatively evaluate the reflection and absorption characteristics of cloud on remote senssing application and energy cycle of the imbalance of nature, it is necessary to obtain the scattering properties of cloud particles. Since the shapes of the water cloud particle are close to spherical, scattering properties of the particles can be calculated accurately by the Mie theory. However, Cirrus particles have a complex shape, including hexagonal, plate, and other non- spherical shapes. Different from warm water cloud partical, it is required to use several different light scattering methods when calculating the light scattering properties of the non-spherical Cirrus cloud particals. Ishimoto et al. [2010, 2012] and Masuda et al. [2012] developed the Finite-Difference Time Domain method (FDTD) and Improved Geometrical-Optics Method (IGOM) for the solution of light scattering by non-spherical particles. Nakajima et al [1997,2009] developed the LIght Scattering solver for Arbitral Shape particle (Lisas)-Geometrical-Optics Method (GOM) and Surface Integral Equations Method of Müller-type (SIEMM) to calculate the light scattering properties for hexagonal ice crystals. Lisas/GOM and IGOM methods are efficient for calculating the single scattering properties of the ice crystal when size parameter is large enough, while exact solution such as FDTD and Lisas/SIEMM methods are efficient for calculating the light scattering properties of the non-spherical partical when size parameter is small. However, to develop the compact light scattering database for satellite remote sensing application, it is important to optimize the scattering database based on the specification of the satellite sensor. Letu et al. (2012) optimized the ice crystal scattering database for Cirrus cloud remote sensing of the GCOM-C/SGLI satellite mission of JAXA, Japan and radiative transfer calculation in earth atmospheric system. Based on the above optimization results, we developed the ice crystal scattering database for GCOM-C/SGLI satellite mission with hexagonal, plate and aggregate shapes determined by in-situ observation for radiative transfer calculation and satellite remote sensing retrieval. Futuermore, radiance flux, alculated by RSTAR radiative transfer code with scattering database of the water cloud and the Cirrus particle is compared both at the earth surface and at the top of atmosphere. Furthermore, calculation uncertainty caused by different cloud particle scattering database was discussed.

Letu, H.; Nakajima, T. Y.; Nagao, T. M.; Ishimoto, H.

2013-12-01

296

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

PubMed

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

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

2014-03-12

297

The energy sector is comprised of a wide range of businesses involved in the exploration, extraction, production, refining, distribution, and sale of energy. The primary  

E-print Network

, extraction, production, refining, distribution, and sale of energy. The primary industries within this sector are its business practices affected by climate change, but energy production and use also play a dominantOVERVIEW The energy sector is comprised of a wide range of businesses involved in the exploration

298

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

NASA Astrophysics Data System (ADS)

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

Karman, Deniz

2011-06-01

299

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

PubMed Central

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

Hu, Bing; Bu, Xianbiao; Ma, Weibin

2014-01-01

300

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

301

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

SciTech Connect

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

English, R.E.

1986-02-01

302

A comparison of muscular mechanical energy expenditure and internal work in cycling.  

PubMed

The hypothesis that the sum of the absolute changes in mechanical energy (internal work) is correlated with the muscular mechanical energy expenditure (MMEE) was tested using two elliptical chainrings, one that reduced and one that increased the internal work (compared to circular). Upper and lower bounds were put on the extra MMEE (work done by net joint torques in excess of the external work) with respect to the effect of intercompensation between joint torques due to biarticular muscles. This was done by having two measures of MMEE, one that allowed no intercompensation and one that allowed complete intercompensation between joints spanned by biarticular muscles. Energy analysis showed no correlation between internal work and the two measures of MMEE. When compared to circular, the chainring that reduced internal work increased MMEE, and phases of increased crank velocity associated with the elliptical shape resulted in increased power absorbed by the upstroke leg as it was accelerated against gravity. The resulting negative work necessitated additional positive work. Thus, the hypothesis that the internal work is correlated with MMEE was found to be invalid, and the total mechanical work done cannot be estimated by summing the internal and external work. Changes in the dynamics of cycling caused by a non-circular chainring may affect performance and must be considered during the non-circular chainring design process. PMID:7806553

Kautz, S A; Hull, M L; Neptune, R R

1994-12-01

303

Energy-efficient low duty cycle MAC protocol for wireless body area networks.  

PubMed

This paper presents an energy-efficient medium access control protocol suitable for communication in a wireless body area network for remote monitoring of physiological signals such as EEG and ECG. The protocol takes advantage of the static nature of the body area network to implement the effective time-division multiple access (TDMA) strategy with very little amount of overhead and almost no idle listening (by static, we refer to the fixed topology of the network investigated). The main goal is to develop energy-efficient and reliable communication protocol to support streaming of large amount of data. TDMA synchronization problems are discussed and solutions are presented. Equations for duty cycle calculation are also derived for power consumption and battery life predictions. The power consumption model was also validated through measurements. Our results show that the protocol is energy efficient for streaming communication as well as sending short bursts of data, and thus can be used for different types of physiological signals with different sample rates. The protocol is implemented on the analog devices ADF7020 RF transceivers. PMID:19846380

Marinkovi?, Stevan Jovica; Popovici, Emanuel Mihai; Spagnol, Christian; Faul, Stephen; Marnane, William Peter

2009-11-01

304

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

305

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

PubMed Central

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

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

2012-01-01

306

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

307

Progress in Photovoltaics Research and Applications, 14:179-190, 2006 Energy Pay-Back and Life Cycle CO2 Emissions of the BOS in an  

E-print Network

eliminating the need for concrete foundations. The estimate of the life-cycle energy requirements embodied installation where the life-cycle energy requirements are drastically lower than Progress in Photovoltaics Research and Applications, 14:179-190, 2006 Energy Pay-Back and Life

308

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

PubMed

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

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

2014-01-01

309

Hepatitis B virus X protein increases expression of p21 Cip-1\\/WAF1\\/MDA6 and p27 Kip1 in primary mouse hepatocytes, leading to reduced cell cycle progression  

Microsoft Academic Search

Previously, we have linked prolonged intense mitogen-activated protein kinase (MAP kinase; MAPK) signaling in hepatocytes to increased expression of p21Cip-1\\/WAF1\\/MDA6 (p21) and p16INK4a (p16), that leads to a p21-dependent growth arrest. In this study, we investigated the impact of hepatitis B virus X protein (pX) expression on MAPK-modulated cell cycle progression in primary mouse hepatocytes. In hepatocytes, expression of pX

Liang Qiao; Kevin Leach; Robert McKinstry; Donna Gilfor; Adly Yacoub; Jong Sung Park; Steven Grant; Philip B. Hylemon; Paul B. Fisher; Paul Dent

2001-01-01

310

Thermochemical cycles for energy storage: Thermal decomposition of ZnCOâ systems. Final topical report, January 1, 1982December 31, 1984  

Microsoft Academic Search

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 (NHâHSOâ) 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,

Wentworth

1992-01-01

311

Abstract--MAC layer duty-cycling is widely used to reduce idling listening, which is energy-intensive in wireless sensor  

E-print Network

1 Abstract--MAC layer duty-cycling is widely used to reduce idling listening, which is energy-intensive in wireless sensor networks. Among duty-cycling MAC protocols, asynchronous protocols generally have higher model to analyze the throughput of X-MAC, an asynchronous duty-cycled MAC protocol for wireless sensor

Heinzelman, Wendi

312

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

SciTech Connect

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

NONE

1998-01-01

313

Bioenergy co-products derived from microalgae biomass via thermochemical conversion--life cycle energy balances and CO2 emissions.  

PubMed

An investigation of the potential to efficiently convert lipid-depleted residual microalgae biomass using thermochemical (gasification at 850 °C, pyrolysis at 550 °C, and torrefaction at 300 °C) processes to produce bioenergy derivatives was made. Energy indicators are established to account for the amount of energy inputs that have to be supplied to the system in order to gain 1 MJ of bio-energy output. The paper seeks to address the difference between net energy input-output balances based on a life cycle approach, from "cradle-to-bioenergy co-products", vs. thermochemical processes alone. The experimental results showed the lowest results of Net Energy Balances (NEB) to be 0.57 MJ/MJ bio-oil via pyrolysis, and highest, 6.48 MJ/MJ for gas derived via torrefaction. With the complete life cycle process chain factored in, the energy balances of NEBLCA increased to 1.67 MJ/MJ (bio-oil) and 7.01 MJ/MJ (gas). Energy efficiencies and the life cycle CO2 emissions were also calculated. PMID:23810951

Khoo, H H; Koh, C Y; Shaik, M S; Sharratt, P N

2013-09-01

314

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

NASA Technical Reports Server (NTRS)

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, SAMPBX, and STEREO spacecraft and extend from approximately 0.1 to approximately 500-700 MeV. All of the proton spectra exhibit spectral breaks at energies ranging from approximately 2 to approximately 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 greater than 40 MeV/nuc. In the energy range 45 to 80 MeV/nucleon about approximately 50% of GLE events have properties in common with impulsive He-3-rich SEP events, including enrichments in Ne/O, Fe/O, Ne-22/Ne-20, and elevated mean charge states of Fe. These He-3 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(sub Fe) is approximately equal to +20 if the acceleration starts at approximately 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.; COhen, C. M. S.; Labrador, A. W.; Leske, R. A.; Looper, M. D.; Haggerty, D. K.; Mason, G. M.; Mazur, J. E.; vonRosenvinge, T. T.

2012-01-01

315

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

316

Analysis of community solar systems for combined space and domestic hot water heating using annual cycle thermal energy storage  

Microsoft Academic Search

A simplified design procedure was examined for estimating the storage capacity and collector area for annual-cycle-storage, community solar heating systems in which 100% of the annual space heating energy demand is provided from the solar source for the typical meteorological year. Hourly computer simulations of the performance of these systems were carried out for 10 cities in the United States

F. C. Hooper; J. D. McClenahan; J. D. Cook; F. Baylin; R. Monte; S. Sillman

1980-01-01

317

The storm tracks and the energy cycle of the Southern Hemisphere: sensitivity to sea-ice boundary conditions  

E-print Network

The storm tracks and the energy cycle of the Southern Hemisphere: sensitivity to sea-ice boundary. The eect of sea-ice on various aspects of the Southern Hemisphere (SH) extratropical climate is examined. Two simulations using the LMD GCM are performed: a control run with the observed sea-ice distribution

Paris-Sud XI, Université de

318

Life cycle assessment of urban waste management: Energy performances and environmental impacts. The case of Rome, Italy  

Microsoft Academic Search

Landfilling is nowadays the most common practice of waste management in Italy in spite of enforced regulations aimed at increasing waste pre-sorting as well as energy and material recovery. In this work we analyse selected alternative scenarios aimed at minimizing the unused material fraction to be delivered to the landfill. The methodological framework of the analysis is the life cycle

Francesco Cherubini; Silvia Bargigli; Sergio Ulgiati

2008-01-01

319

A load-aware energy-efficient and throughput-maximized asynchronous duty cycle MAC for wireless sensor networks  

Microsoft Academic Search

Being a pivotal resource, conservation of energy has been considered as the most striking issue in the wireless sensor network\\u000a research. Several works have been performed in the last years to devise duty cycle based MAC protocols which optimize energy\\u000a conservation emphasizing low traffic load scenario. In contrast, considering the high traffic situation, another research\\u000a trend has been continuing to

Muhammad Mostafa Monowar; Muhammad Mahbub Alam; Choong Seon Hong; Sungwon Lee

2010-01-01

320

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

321

An approximate energy cycle for inter-member variability in ensemble simulations of a regional climate model  

NASA Astrophysics Data System (ADS)

The presence of internal variability (IV) in ensembles of nested regional climate model (RCM) simulations is now widely acknowledged in the community working on dynamical downscaling. IV is defined as the inter-member spread between members in an ensemble of simulations performed by a given RCM driven by identical lateral boundary conditions (LBC), where different members are being initialised at different times. The physical mechanisms responsible for the time variations and structure of such IV have only recently begun to receive attention. Recent studies have shown empirical evidence of a close parallel between the energy conversions associated with the time fluctuations of IV in ensemble simulations of RCM and the energy conversions taking place in weather systems. Inspired by the classical work on global energetics of weather systems, we sought a formulation of an energy cycle for IV that would be applicable for limited-area domain. We develop here a novel formalism based on local energetics that can be applied to further our understanding IV. Prognostic equations for ensemble-mean kinetic energy and available enthalpy are decomposed into contributions due to ensemble-mean variables (EM) and those due to deviations from the ensemble mean (IV). Together these equations constitute an energy cycle for IV in ensemble simulations of RCM. Although the energy cycle for IV was developed in a context entirely different from that of energetics of weather systems, the exchange terms between the various reservoirs have a rather similar mathematical form, which facilitates some interpretations of their physical meaning.

Nikiéma, Oumarou; Laprise, René

2013-08-01

322

Plasma-Based Generation and Control of a Single Few-Cycle High-Energy Ultrahigh-Intensity Laser Pulse  

NASA Astrophysics Data System (ADS)

A laser-boosted relativistic solid-density paraboloidal foil is known to efficiently reflect and focus a counterpropagating laser pulse. Here we show that in the case of an ultrarelativistic counterpropagating pulse, a high-energy and ultrahigh-intensity reflected pulse can be more effectively generated by a relatively slow and heavy foil than by a fast and light one. This counterintuitive result is explained with the larger reflectivity of a heavy foil, which compensates for its lower relativistic Doppler factor. Moreover, since the counterpropagating pulse is ultrarelativistic, the foil is abruptly dispersed and only the first few cycles of the counterpropagating pulse are reflected. Our multidimensional particle-in-cell simulations show that even few-cycle counterpropagating laser pulses can be further shortened (both temporally and in the number of laser cycles) with pulse amplification. A single few-cycle, multipetawatt laser pulse with several joules of energy and with a peak intensity exceeding 1023 W/cm2 can be generated already employing next-generation high-power laser systems. In addition, the carrier-envelope phase of the generated few-cycle pulse can be tuned provided that the carrier-envelope phase of the initial counterpropagating pulse is controlled.

Tamburini, M.; Di Piazza, A.; Liseykina, T. V.; Keitel, C. H.

2014-07-01

323

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

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

324

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

SciTech Connect

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 O{sub 2}, N{sub 2}, and CO{sub 2} 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 induced by gas mass transfer and water evaporation at the bubble-liquid interface, as well as by the decreasing hydrostatic pressure. Heterogeneous nucleation at pipe wall crevices and on suspended particles in the water stream is also modeled. Bubble coalescence due to turbulent shear and differential buoyancy is simulated. The results generated show the deaeration efficiency as a function of flow and geometric parameters. The calculations show that gas desorption in the barometric upcomers can be appreciable. Such desorption is enhanced by increasing the concentration of the incoming and/or the heterogeneously formed bubbles. Results of existing experiments are discussed and predictions are shown for the selected test conditions.

Ghiaasiaan, S.M.; Wassel, A.T. (Science Applications International Corporation, Torrance, CA (US)); Pesaran, A.A. (Solar Energy Research Inst., Golden, CO (USA))

1990-08-01

325

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

326

Evidence for Solar Cycle Influence on the Infrared Energy Budget and Radiative Cooling of the Thermosphere  

NASA Technical Reports Server (NTRS)

We present direct observational evidence for solar cycle influence on the infrared energy budget and radiative cooling of the thermosphere. By analyzing nearly five years of data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, we show that the annual mean infrared power radiated by the nitric oxide (NO) molecule at 5.3 m has decreased by a factor of 2.9. This decrease is correlated (r = 0.96) with the decrease in the annual mean F10.7 solar index. Despite the sharp decrease in radiated power (which is equivalent to a decrease in the vertical integrated radiative cooling rate), the variability of the power as given in the standard deviation of the annual means remains approximately constant. A simple relationship is shown to exist between the infrared power radiated by NO and the F10.7 index, thus providing a fundamental relationship between solar activity and the thermospheric cooling rate for use in thermospheric models. The change in NO radiated power is also consistent with changes in absorbed ultraviolet radiation over the same time period.

Mlynczak, Martin G.; Martin-Torres, F. Javier; Marshall, B. Thomas; Thompson, R. Earl; Williams, Joshua; Turpin, TImothy; Kratz, D. P.; Russell, James M.; Woods, Tom; Gordley, Larry L.

2007-01-01

327

Climate change mitigation by recovery of energy from the water cycle: a new challenge for water management.  

PubMed

Waternet is responsible for drinking water treatment and distribution, wastewater collection and treatment, and surface water management and control (quality and quantity) in and around Amsterdam. Waternet has the ambition to operate climate neutral in 2020. To realise this ambition, measures are required to compensate for the emission of 53,000 ton CO(2)-eq/year. Energy recovery from the water cycle looks very promising. First, calculations reveal that energy recovery from the water cycle in and around Amsterdam may contribute to a total reduction in greenhouse gas emissions up to 148,000 ton CO(2)-eq/year. The challenge for the coming years is to choose combinations of all the possibilities to fulfil the energy demand as much as possible. Only then the use of fossil fuel can be minimized and inevitable greenhouse gas emissions can be compensated, supporting the target to operate climate neutral in 2020. PMID:22173417

van der Hoek, J P

2012-01-01

328

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

Microsoft Academic Search

This report documents the development and use of the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The model, developed in a spreadsheet format, estimates the full fuel- cycle emissions and energy use associated with various transportation fuels for light-duty vehicles. The model calculates fuel-cycle emissions of five criteria pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides,

1996-01-01

329

An integrated life cycle assessment model: Energy and greenhouse gas performance of residential heritage buildings, and the influence of retrofit strategies in the state of Victoria in Australia  

Microsoft Academic Search

Heritage buildings are of significant cultural importance to Australia. They are at risk of becoming obsolete under the stringent building energy efficiency regulations being introduced currently. This article develops an integrated framework combining building energy efficiency simulation and appliance characteristic components, with a five stage life cycle assessment framework. The life cycle performance of eight residential heritage buildings in Victoria

Deepak Sivaraman

330

Catalyst Needs for Thermochemical Hydrogen Production Cycles  

SciTech Connect

Thermochemical cycles can be used to split water through a series of chemical reactions where the net result is the production of hydrogen and oxygen at much lower temperatures than direct thermal decomposition. All chemicals within the cycle are fully recycled and the heat to drive the reactions, which tend to be endothermic, must be provided by a primary energy source. When the primary energy driver is nuclear heat, hydrogen can be generated without producing green-house gases, and can provide independence from our dwindling supplies of fossil fuels. A number of thermochemical cycles can be driven by the primary heat of nuclear reactors, especially a very high temperature reactor (VHTR). The sulfur-based family of thermochemical cycles, including the Sulfur- Iodine cycle (S-I), the Hybrid Sulfur cycle, and the Sulfur-Bromine Hybrid cycle, appears promising for producing hydrogen using nuclear heat. These cycles employ a high-temperature sulfuric acid decomposition reaction step. The reaction produces oxygen and generates SO{sub 2}, which is used in other reaction steps of the cycles. The reaction takes place from 750 to 900 deg. C, or higher, and is facilitated by heterogeneous catalysts. The S-I cycle produces hydrogen by the catalytic decomposition of HI. The calcium-bromine cycle is also being considered as a nuclear powered thermochemical cycle. The various cycles all present requirements of high temperatures and harsh chemical reaction conditions which present significantly challenging environments for catalytic materials. This work will focus on the catalyst needs of thermochemical cycles that are candidates for being powered by nuclear reactors. Specific catalyst activity and stability testing results will be provided for the decomposition of sulfuric acid for the production of oxygen in the sulfur-based family of cycles and for the catalytic decomposition of hydro-iodic acid for the production of hydrogen in the S-I process. Sulfuric acid decomposition results will focus primarily on platinum group metal catalyst while HI decomposition results will be presented mainly on activated carbon catalysts. (authors)

Ginosar, Daniel M.; Petkovic, Lucia M.; Rollins, Harry W.; Burch, Kyle C. [Idaho National Laboratory, Chemical Sciences, P.O. Box 1625, Idaho Falls, ID 83415-2208 (United States)

2007-07-01

331

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

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

332

Homology-mediated end-capping as a primary step of sister chromatid fusion in the breakage-fusion-bridge cycles  

PubMed Central

Breakage-fusion-bridge (BFB) cycle is a series of chromosome breaks and duplications that could lead to the increased copy number of a genomic segment (gene amplification). A critical step of BFB cycles leading to gene amplification is a palindromic fusion of sister chromatids following the rupture of a dicentric chromosome during mitosis. It is currently unknown how sister chromatid fusion is produced from a mitotic break. To delineate the process, we took an integrated genomic, cytogenetic and molecular approach for the recurrent MCL1 amplicon at chromosome 1 in human tumor cells. A newly developed next-generation sequencing-based approach identified a cluster of palindromic fusions within the amplicon at ?50-kb intervals, indicating a series of breaks and fusions by BFB cycles. The physical location of the amplicon (at the end of a broken chromosome) further indicated BFB cycles as underlying processes. Three palindromic fusions were mediated by the homologies between two nearby inverted Alu repeats, whereas the other two fusions exhibited microhomology-mediated events. Such breakpoint sequences indicate that homology-mediated fold-back capping of broken ends followed by DNA replication is an underlying mechanism of sister chromatid fusion. Our results elucidate nucleotide-level events during BFB cycles and end processing for naturally occurring mitotic breaks. PMID:23975201

Marotta, Michael; Chen, Xiongfong; Watanabe, Takaaki; Faber, Pieter W.; Diede, Scott J.; Tapscott, Stephen; Tubbs, Raymond; Kondratova, Anna; Stephens, Robert; Tanaka, Hisashi

2013-01-01

333

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

334

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

335

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

336

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 5: Combined gas-steam turbine cycles. [energy conversion efficiency in electric power plants  

NASA Technical Reports Server (NTRS)

The energy conversion efficiency of gas-steam turbine cycles was investigated for selected combined cycle power plants. Results indicate that it is possible for combined cycle gas-steam turbine power plants to have efficiencies several point higher than conventional steam plants. Induction of low pressure steam into the steam turbine is shown to improve the plant efficiency. Post firing of the boiler of a high temperature combined cycle plant is found to increase net power but to worsen efficiency. A gas turbine pressure ratio of 12 to 1 was found to be close to optimum at all gas turbine inlet temperatures that were studied. The coal using combined cycle plant with an integrated low-Btu gasifier was calculated to have a plant efficiency of 43.6%, a capitalization of $497/kW, and a cost of electricity of 6.75 mills/MJ (24.3 mills/kwh). This combined cycle plant should be considered for base load power generation.

Amos, D. J.; Foster-Pegg, R. W.; Lee, R. M.

1976-01-01

337

Life-Cycle Assessment of Energy Use and Greenhouse Gas Emissions of Soybean-Derived Biodiesel and Renewable Fuels  

SciTech Connect

In this study, we used Argonne National Laboratory's Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model to assess the life-cycle energy and greenhouse gas (GHG) emission impacts of four soybean-derived fuels: biodiesel fuel produced via transesterification, two renewable diesel fuels (I and II) produced from different hydrogenation processes, and renewable gasoline produced from catalytic cracking. Five approaches were employed to allocate the coproducts: a displacement approach; two allocation approaches, one based on the energy value and the other based on the market value; and two hybrid approaches that integrated the displacement and allocation methods. The relative rankings of soybean-based fuels in terms of energy and environmental impacts were different under the different approaches, and the reasons were analyzed. Results from the five allocation approaches showed that although the production and combustion of soybean-based fuels might increase total energy use, they could have significant benefits in reducing fossil energy use (>52%), petroleum use (>88%), and GHG emissions (>57%) relative to petroleum fuels. This study emphasized the importance of the methods used to deal with coproduct issues and provided a comprehensive solution for conducting a life-cycle assessment of fuel pathways with multiple coproducts.

Huo, H.; Wang, M.; Bloyd, C.; Putsche, V.

2009-01-01

338

A novel determination of density, temperature and symmetry energy for nuclear multi-fragmentation through primary fragment yield reconstruction  

E-print Network

For the first time primary hot isotope distributions are experimentally reconstructed in intermediate heavy ion collisions and used with antisymmetrized molecular dynamics (AMD) calculations to determine density, temperature and symmetry energy coefficient in a self-consistent manner. A kinematical focusing method is employed to reconstruct the primary hot fragment yield distributions for multifragmentation events observed in the reaction system $^{64}$Zn + $^{112}$Sn at 40 MeV/nucleon. The reconstructed yield distributions are in good agreement with the primary isotope distributions of AMD simulations. The experimentally extracted values of the symmetry energy coefficient relative to the temperature, $a_{sym}/T$, are compared with those of the AMD simulations with different density dependence of the symmetry energy term. The calculated $a_{sym}/T$ values changes according to the different interactions. By comparison of the experimental values of $a_{sym}/T$ with those of calculations, the density of the source at fragment formation was determined to be $\\rho /\\rho_{0} = (0.63 \\pm 0.03 )$. Using this density, the symmetry energy coefficient and the temperature are determined in a self-consistent manner as $a_{sym} = (24.7 \\pm 1.9) MeV$ and $T=(4.9 \\pm 0.2)$ MeV

W. Lin; X. Liu; M. R. D. Rodrigues; S. Kowalski; R. Wada; M. Huang; S. Zhang; Z. Chen; J. Wang; G. Q. Xiao; R. Han; Z. Jin; J. Liu; F. Shi; T. Keutgen; K. Hagel; M. Barbui; C. Bottosso; A. Bonasera; J. B. Natowitz; E. J. Kim; T. Materna; L. Qin; P. K. Sahu; K. J. Schmidt; S. Wuenschel; H. Zheng

2014-01-02

339

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

340

Comparative Life Cycle Assessments of Lignocellulosic and Algae Biomass Conversion to Various Energy Products through Different Pathways  

Microsoft Academic Search

Bioenergy has the potential to reduce the world's dependence on fossil fuels, and to decrease the CO2 emissions due to fossil combustion. Lignocellulosic and algae biomass have been presented as promising feedstocks for bioenergy production.\\u000aIn this study, a comparative Life Cycle Assessment (LCA) has been developed to evaluate the environmental impacts associated with different energy products via different routes

Maria Juliana Pinilla

2011-01-01

341

Alternative fuel buses currently in use in China: Life-cycle fossil energy use, GHG emissions and policy recommendations  

Microsoft Academic Search

The Chinese government has enacted policies to promote alternative vehicle fuels (AVFs) and alternative fuel vehicles (AFVs), including city bus fleets. The life cycle (LC), energy savings (ES) and GHG reduction (GR) profiles of AVFs\\/AFVs are critical to those policy decisions. The well-to-wheels module of the Tsinghua-CA3EM model is employed to investigate actual performance data. Compared with conventional buses, AFVs

Xunmin Ou; Xiliang Zhang; Shiyan Chang

2010-01-01

342

A new one-dimensional simple energy balance and carbon cycle coupled model for global warming simulation  

Microsoft Academic Search

Global warming and accompanying climate change may be caused by an increase in atmospheric greenhouse gasses generated by\\u000a anthropogenic activities. In order to supply such a mechanism of global warming with a quantitative underpinning, we need\\u000a to understand the multifaceted roles of the Earth's energy balance and material cycles. In this study, we propose a new one-dimensional\\u000a simple Earth system

Kazutaka Murakami; Takahiro Sasai; Yasushi Yamaguchi

2010-01-01

343

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

344

Energy-based approach for the evaluation of low cycle fatigue behaviour of 2.25Cr–1Mo steel at elevated temperature  

Microsoft Academic Search

The energy-based approach for the evaluation of low cycle fatigue behaviour of 2.25Cr–1Mo steel at elevated temperature has been investigated and detailed analyses discussed. Plastic strain energy was determined per cycle and found to characterise both crack initiation and propagation to failure regimes. At cyclic stabilisation, average plastic strain energy may be used as a suitable damage parameter and correlations

M. D. Callaghan; S. R. Humphries; M. Law; M. Ho; P. Bendeich; H. Li; W. Y. Yeung

2010-01-01

345

Characterization of the new free-air primary standard for low-energy X-rays at CMI  

NASA Astrophysics Data System (ADS)

In 2011 a decision was made by Czech Metrology Institute to build a free-air ionization chamber (FAC) intended to be used as a primary standard of air kerma rate for low-energy X-rays (photon energy below 50 keV, including mammography X-ray qualities) in order to replace the currently used secondary ionization chamber and to decrease the uncertainty of air kerma reference value. In the period 2011-2012, the FAC has been designed, manufactured and put into operation. Its performance was tested using a calibrated secondary chamber and then by an informal comparison with a national primary standard of BEV (Austria). Physical characteristics of the FAC are described and individual correction factors are discussed focusing on computational methods utilized in their estimation. Summary of the correction factors with the uncertainty budget is presented.

Šolc, Jaroslav; Sochor, Vladimír

2014-11-01

346

Low-energy primary knock on atom damage distributions near MeV proton beams focused to nanometre dimensions  

NASA Astrophysics Data System (ADS)

In this preliminary study, the spatial extent of the defects introduced in Si by a normally incident 1 MeV H + nanobeam was investigated using a hybrid approach. First, the standard SRIM code was employed to calculate the angular and energy distributions of Primary Knock-on Atoms (PKA) using the Binary Collision Approximation (BCA). The long mean free path and the kinematics of scattering in a screened Coulomb potential resulted in an anisotropic PKA distribution that was mainly directed perpendicular to the primary ion trajectories. The PKA energy E dependence was close to 1/ En with 1.5 < n < 2 such that the vast majority of PKAs had low energies (?40 eV) close to the threshold displacement energy. Subsequently, the low energy PKA data was used as input to a Molecular Dynamics (MD) code that was used to follow the recoil cascades. The force field resulting from Si-Si atom interactions was represented in the MD calculations by the Environmental-Dependant Interaction Potential (EDIP). Finally, the spatial distribution of Self Interstitial Atoms (SIA) and vacancies was characterised using the Pixel Mapping (PM) method. The results revealed that the low energy PKA's resulted in localised damaged regions with Si Self-Interstitial Atoms (SIA) and associated vacancies concentrated within a few nm of the ion track. Although some clustering occurred, the majority of SIA were present as monomers. This is in agreement with previous work on low energy B + implanted Si. The contribution from the spatial distribution of displacements from high energy (>40 eV) PKAs was investigated using SRIM. It was found that within the maximum region of the SIA concentration (1-2 nm radius of the ion track) the contribution from high energy PKA's is relatively unimportant (˜5%).

Whitlow, Harry J.; Nakagawa, Sachiko T.

2007-07-01

347

Energy efficiency and environmental performance of bioethanol production from sweet sorghum stem based on life cycle analysis.  

PubMed

Life cycle analysis method was used to evaluate the energy efficiency and environmental performance of bioethanol production from sweet sorghum stem in China. The scope covers three units, including plant cultivation, feedstock transport, and bioethanol conversion. Results show that the net energy ratio was 1.56 and the net energy gain was 8.37 MJ/L. Human toxicity was identified as the most significant negative environmental impact, followed by eutrophication and acidification. Steam generation in the bioethanol conversion unit contributed 82.28% and 48.26% to total human toxicity and acidification potential, respectively. Fertilizers loss from farmland represented 67.23% of total eutrophication potential. The results were significantly affected by the inventory allocation methods, vinasse reusing approaches, and feedstock yields. Reusing vinasse as fuel for steam generation and better cultivation practice to control fertilizer loss could significantly contribute to enhance the energy efficiency and environmental performance of bioethanol production from sweet sorghum stem. PMID:24787319

Wang, Mingxin; Chen, Yahui; Xia, Xunfeng; Li, Jun; Liu, Jianguo

2014-07-01

348

Nuclear energy in Europe: uranium flow modeling and fuel cycle scenario trade-offs from a sustainability perspective.  

PubMed

The European nuclear fuel cycle (covering the EU-27, Switzerland and Ukraine) was modeled using material flow analysis (MFA).The analysis was based on publicly available data from nuclear energy agencies and industries, national trade offices, and nongovernmental organizations. Military uranium was not considered due to lack of accessible data. Nuclear fuel cycle scenarios varying spent fuel reprocessing, depleted uranium re-enrichment, enrichment assays, and use of fast neutron reactors, were established. They were then assessed according to environmental, economic and social criteria such as resource depletion, waste production, chemical and radiation emissions, costs, and proliferation risks. The most preferable scenario in the short term is a combination of reduced tails assay and enrichment grade, allowing a 17.9% reduction of uranium demand without significantly increasing environmental, economic, or social risks. In the long term, fast reactors could theoretically achieve a 99.4% decrease in uranium demand and nuclear waste production. However, this involves important costs and proliferation risks. Increasing material efficiency is not systematically correlated with the reduction of other risks. This suggests that an overall optimization of the nuclear fuel cycle is difficult to obtain. Therefore, criteria must be weighted according to stakeholder interests in order to determine the most sustainable solution. This paper models the flows of uranium and associated materials in Europe, and provides a decision support tool for identifying the trade-offs of the alternative nuclear fuel cycles considered. PMID:21275398

Tendall, Danielle M; Binder, Claudia R

2011-03-15

349

Energy spectra of secondary particles in ?-families and their sensitivity to the primary cosmic ray (PCR) spectrum  

NASA Astrophysics Data System (ADS)

Spectra of secondary particles in gamma-families, detected at the Pamirs level in X-ray emulsion chambers, are analyzed. This analysis showed that secondary particle spectra change their slope at the particle energy equal to the summary particle energy at which we select gamma-families. Above this bend the secondary particle slope is sensitive to the PCR spectrum slope and composition. The slopes of secondary particle spectra in the Experiment PAMIR are close to the slopes in the variants of the MC0 model, in which the fraction of primary protons is not less than 25% after the knee.

Denisova, V. G.; Guseva, Z. M.; Kanevskaya, E. A.; Maximenko, V. M.; Morozov, A. E.; Puchkov, V. S.; Mukhamedshin, R. A.

2009-12-01

350

Optimal Life Cycle Cost Design for an Energy Efficient Manufacturing Facility  

E-print Network

Over the past twelve years, Texas Instruments has developed extensive energy management programs that have enabled them to reduce energy usage by 42%. Typically, these reductions have been a result of the application of microprocessor based energy...

Thompson, C. T.; Beach, W. P.

1985-01-01

351

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

352

Energy Spectra of Abundant Nuclei of Primary Cosmic Rays from the Data of ATIC-2 Experiment: Final Results  

E-print Network

The final results of processing the data from the balloon-born experiment ATIC-2 (Antarctica, 2002-2003) for the energy spectra of protons and He, C, O, Ne, Mg, Si, and Fe nuclei, the spectrum of all particles, and the mean logarithm of atomic weight of primary cosmic rays as a function of energy are presented. The final results are based on improvement of the methods used earlier, in particular, considerably increased resolution of the charge spectrum. The preliminary conclusions on the significant difference in the spectra of protons and helium nuclei (the proton spectrum is steeper) and the non-power character of the spectra of protons and heavier nuclei (flattening of carbon spectrum at energies above 10 TeV) are confirmed. A complex structure of the energy dependence of the mean logarithm of atomic weight is found.

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

2011-01-01

353

Microstructure-sensitive weighted probability approach for modeling surface to bulk transition of high cycle fatigue failures dominated by primary inclusions  

NASA Astrophysics Data System (ADS)

The mechanical alloying and casting processes used to make polycrystalline metallic materials often introduce undesirable non-metallic inclusions and pores. These are often the dominant sites of fatigue failure origination at the low stress amplitudes that correspond to the high cycle fatigue (HCF) and very high cycle fatigue (VHCF) regimes, in which the number of cycles to crack initiation is more than 106. HCF and VHCF experiments on some advanced metallic alloys, such as powder metallurgy Ni-base superalloys, titanium alloys, and high-strength steels have shown that the critical inclusions and pores can appear on the surface as well as in the bulk of the specimen. Fatigue lives have been much higher for specimens that fail from a bulk site. The relative number of bulk initiations increases as the stress amplitude decreases such that just below the traditional HCF limit, fatigue life data appears to be evenly scattered between two datasets corresponding to surface and bulk initiations. This is often referred to as surface to bulk transition in the VHCF regime. Below this transition stress, the likelihood of surface versus bulk initiation significantly impacts the low failure probability estimate of fatigue life. Under these circumstances, a large number of very costly experiments need to be conducted to obtain a statistically representative distribution of fatigue life and to predict the surface versus bulk initiation probability. In this thesis, we pursue a simulation-based approach whereby microstructure-sensitive finite element simulations are performed within a statistical construct to examine the VHCF life variability and assess the surface initiation probability. The methodology introduced in this thesis lends itself as a cost-effective platform for development of microstructure-property relations to support design of new or modified alloys, or to more efficiently predict the properties of existing alloys.

Salajegheh, Nima

354

Research in Support of the Use of Rankine Cycle Energy Conversion Systems for Space Power and Propulsion  

NASA Technical Reports Server (NTRS)

This is the report of a Scientific Working Group (SWG) formed by NASA to determine the feasibility of using a liquid metal cooled nuclear reactor and Rankine energy conversion cycle for dual purpose power and propulsion in space. This is a high level technical report which is intended for use by NASA management in program planning. The SWG was composed of a team of specialists in nuclear energy and multiphase flow and heat transfer technology from academia, national laboratories, NASA and industry. The SWG has identified the key technology issues that need to be addressed and have recommended an integrated short term (approx. 2 years) and a long term (approx. 10 year) research and development (R&D) program to qualify a Rankine cycle power plant for use in space. This research is ultimately intended to give NASA and its contractors the ability to reliably predict both steady and transient multiphase flow and heat transfer phenomena at reduced gravity, so they can analyze and optimize designs and scale-up experimental data on Rankine cycle components and systems. In addition, some of these results should also be useful for the analysis and design of various multiphase life support and thermal management systems being considered by NASA.

Lahey, Richard T., Jr.; Dhir, Vijay

2004-01-01

355

The Oxygen Cycle.  

ERIC Educational Resources Information Center

Produced for primary grades, this booklet provides study of the oxygen-carbon dioxide cycle in nature. Line drawings, a minimum amount of narrative, and a glossary of terms make up its content. The booklet is designed to be used as reading material, a coloring book, or for dramatic arts with students acting out parts of the cycle. This work was…

Swant, Gary D.

356

Power Plant Cycling Costs  

SciTech Connect

This report provides a detailed review of the most up to date data available on power plant cycling costs. The primary objective of this report is to increase awareness of power plant cycling cost, the use of these costs in renewable integration studies and to stimulate debate between policymakers, system dispatchers, plant personnel and power utilities.

Kumar, N.; Besuner, P.; Lefton, S.; Agan, D.; Hilleman, D.

2012-07-01

357

Navigating wastewater energy recovery strategies: a life cycle comparison of anaerobic membrane bioreactor and conventional treatment systems with anaerobic digestion.  

PubMed

The objective of this study was to evaluate emerging anaerobic membrane bioreactor (AnMBR) technology in comparison with conventional wastewater energy recovery technologies. Wastewater treatment process modeling and systems analyses were combined to evaluate the conditions under which AnMBR may produce more net energy and have lower life cycle environmental emissions than high rate activated sludge with anaerobic digestion (HRAS+AD), conventional activated sludge with anaerobic digestion (CAS+AD), and an aerobic membrane bioreactor with anaerobic digestion (AeMBR+AD). For medium strength domestic wastewater treatment under baseline assumptions at 15 °C, AnMBR recovered 49% more energy as biogas than HRAS+AD, the most energy positive conventional technology considered, but had significantly higher energy demands and environmental emissions. Global warming impacts associated with AnMBR were largely due to emissions of effluent dissolved methane. For high strength domestic wastewater treatment, AnMBR recovered 15% more net energy than HRAS+AD, and the environmental emissions gap between the two systems was reduced. Future developments of AnMBR technology in low energy fouling control, increased flux, and management of effluent methane emissions would make AnMBR competitive with HRAS+AD. Rapid advancements in AnMBR technology must continue to achieve its full economic and environmental potential as an energy recovery strategy for domestic wastewater. PMID:24742289

Smith, Adam L; Stadler, Lauren B; Cao, Ling; Love, Nancy G; Raskin, Lutgarde; Skerlos, Steven J

2014-05-20

358

Determination of primary energy in nucleus-nucleus collisions and the high P(sub)T tail of alpha-particles  

NASA Astrophysics Data System (ADS)

A determination of primary energy is required in order to study the energy dependence of meson multiplicity in A-A collisions in cosmic rays. Various procedures which estimate the energy of a primary nucleus from its interaction were investigated. An average of two methods were used, one using the pions and wounded protons and the other using spectator protons and alpha particles. The high PT tail observed for Z = 2 fragments requires a modification of the latter method.

Freier, P. S.; Atwater, T. W.

1985-08-01

359

Wind Energy Electrical Power Generation: Industrial Life Cycle of a Radical Innovation  

Microsoft Academic Search

This study addresses past, current and future development of the wind electrical power industry, that began prior to 1890 in Cleveland, Ohio and Askov, Denmark... Overcoming technological, business, societal and political hurdles required approximately 120 years of exploration to establish wind electricity generation as a radical innovation entering the acceleration stage of the industrial technology life cycle. Further growth and

J. P. Dismukes; L. K. Miller; A. Solocha; S. Jagani; J. A. Bers

2007-01-01

360

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

361

Cycling performance of the iron-chromium redox energy storage system  

NASA Technical Reports Server (NTRS)

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

362

Cycling Performance of the Iron-Chromium Redox Energy Storage System  

NASA Technical Reports Server (NTRS)

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

363

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

364

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

365

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

366

Solar wind-magnetosphere energy coupling efficiency and partitioning: HILDCAAs and preceding CIR storms during solar cycle 23  

NASA Astrophysics Data System (ADS)

quantitative study on the energetics of the solar wind-magnetosphere-ionosphere system during High-Intensity, Long-Duration, Continuous AE Activity (HILDCAA) events for solar cycle 23 (from 1995 through 2008) is presented. For all HILDCAAs, the average energy transferred to the magnetospheric/ionospheric system was ~6.3 ×1016 J, and the ram kinetic energy of the incident solar wind was ~7.1 ×1018 J. For individual HILDCAA events the coupling efficiency, defined as the ratio of the solar wind energy input to the solar wind kinetic energy, varied between 0.3% and 2.8%, with an average value of ~0.9%. The solar wind coupling efficiency for corotating interaction region (CIR)-driven storms prior to the HILDCAA events was found to vary from ~1% to 5%, with an average value of ~2%. Both of these values are lower than the> 5% coupling efficiency noted for interplanetary coronal mass ejection (and sheath)-driven magnetic storms. During HILDCAAs, ~67% of the solar wind energy input went into Joule heating, ~22% into auroral precipitation, and ~11% into the ring current energy. The CIR-storm Joule heating (~49%) was noticeably less than that during HILDCAAs, while the ring current energies were comparable for the two. Joule dissipation was higher for HILDCAAs that followed CIR-storms (88%) than for isolated HILDCAAs (~60%). Possible physical interpretations for the statistical results obtained in this paper are discussed.

Hajra, Rajkumar; Echer, Ezequiel; Tsurutani, Bruce T.; Gonzalez, Walter D.

2014-04-01

367

Effects of prolactin on the luteinizing hormone response to gonadotropin- releasing hormone in primary pituitary cell cultures during the ovine annual reproductive cycle.  

PubMed

In the sheep pituitary, the localization of prolactin (PRL) receptors in gonadotrophs and the existence of gonadotroph-lactotroph associations have provided morphological evidence for possible direct effects of PRL on gonadotropin secretion. Here, we investigated whether PRL can readily modify the LH response to GnRH throughout the ovine annual reproductive cycle. Cell populations were obtained from sheep pituitaries during the breeding season (BS) and the nonbreeding season (NBS), plated to monolayer cultures for 7 days, and assigned to receive one of the following treatments: 1) nil (control), 2) acute (90- min) bromocriptine (ABr), 3) chronic (7-day) bromocriptine (CBr), 4) ABr and PRL, 5) CBr and PRL, 6) PRL alone, or 7) thyrotropin-releasing hormone. Cells were treated as described above, with the aim of decreasing or increasing the concentrations of PRL in the culture, and simultaneously treated with GnRH for 90 min. The LH concentrations in the medium were then determined by RIA. GnRH stimulated LH in a dose-dependent manner during both stages of the annual reproductive cycle. During the NBS, single treatments did not significantly affect the LH response to GnRH. However, when PRL was combined with bromocriptine, either acutely or chronically, GnRH failed to stimulate LH release at all doses tested (P < 0.01). In contrast, during the BS, the LH response to GnRH was not affected by any of the experimental treatments. These results reveal no apparent effects of PRL alone, but an interaction between PRL and dopamine in the regulation of LH secretion within the pituitary gland, and a seasonal modulation of this mechanism. PMID:14695904

Gregory, Susan J; Townsend, Julie; McNeilly, Alan S; Tortonese, Domingo J

2004-05-01

368

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

E-print Network

PAYBACK TIMES AND NET ENERGY PRODUCTION VALUE Vasilis Fthenakis1,2 , Rick Betita2 , Mark Shields3 , Rob the metric of Net Energy Production Value (NEPV), which shows the solar electricity production after of LCA is the cumulative energy demand, encompassing all energy used in the production and the other

369

The Energy Return on Energy Investment (EROI) of Photovoltaics: Methodology and Comparisons with Fossil Fuel Life Cycles  

E-print Network

with Fossil Fuel Life Cycles Marco Raugei*1,2 , Pere Fullana-i-Palmer1 and Vasilis Fthenakis2,3 1 UNESCO Chair-term viability. The EROI of conventional thermal electricity from fossil fuels has been viewed as being much and present updated EROI values for a range of modern PV systems, in comparison to conventional fossil-fuel

370

Solar cycle 23 analysis  

Microsoft Academic Search

Here we analyse the solar cycle (SC) 23 behavior and we also make a comparison with some previous cycles and present a few aspects concerning the forecasts made for SC 23 maximum. As regards the following cycle, in accordance to other early predictions, our empirical method, based on observing the flare energy release during the descendant phase of the precedent

Georgeta Maris; Miruna Daniela Popescu; Diana Besliu

2004-01-01

371

Primary proton spectrum in the energy range $5-10^3$ TeV from the sea level muon spectrum  

E-print Network

Primary proton spectrum in the energy range $5-10^3$ TeV is reconstructed from the sea level muon spectrum with the use of QGSJET01 and SYBILL2.1 interaction models. Heavier nuclei are taken in accordance with the direct measurements data, 100% uncertainty in helium flux is accounted for. The obtained proton intensity strongly contradicts to the available data of balloon experiments, exceeding them at the least by 100% for QGSJET01. This discrepancy is due to the combined effect of primary nucleon flux underestimation in the direct measurements and incorrect description of extensive air shower development. In the latter case it is required earlier shower development and harder spectra of secondary pions and kaons in comparison with QGSJET01. This conclusion is in agreement with the obtained by the KASCADE group on the basis of events rate study.

Lagutin, A A; Yushkov, A V

2005-01-01

372

Primary proton spectrum in the energy range $5-10^3$ TeV from the sea level muon spectrum  

E-print Network

Primary proton spectrum in the energy range $5-10^3$ TeV is reconstructed from the sea level muon spectrum with the use of QGSJET01 and SYBILL2.1 interaction models. Heavier nuclei are taken in accordance with the direct measurements data, 100% uncertainty in helium flux is accounted for. The obtained proton intensity strongly contradicts to the available data of balloon experiments, exceeding them at the least by 100% for QGSJET01. This discrepancy is due to the combined effect of primary nucleon flux underestimation in the direct measurements and incorrect description of extensive air shower development. In the latter case it is required earlier shower development and harder spectra of secondary pions and kaons in comparison with QGSJET01. This conclusion is in agreement with the obtained by the KASCADE group on the basis of events rate study.

A. A. Lagutin; A. G. Tyumentsev; A. V. Yushkov

2005-07-01

373

Energy transfer in the primary stages of the photosynthetic process investigated by picosecond time resolved fluorescence spectroscopy  

NASA Astrophysics Data System (ADS)

The fate of the absorbed light energy in the primary stages of the photosynthetic process was studied. In particular, the energy transfer in the accessory pigment complex consisting of carotenoids, Chl. a and Chl. b in higher green plants and phycobiliproteins in blue-green algae were investigated. These accessory pigments are responsible for the highly efficient transfer of the excitation energy to the photochemically active reaction center traps. The risetime, decay time, fluorescence depolarization, temperature and intensity dependence of the fluoresence emission from higher green plant and algal photosystems were directly measured. Excitation was provided by single picosecond laser pulses, as well as a train of pulses at 530 nm, within an intensity range of 10 to the 12th power to 10 to the 16th power photons/sq cm per pulse.

Pellegrino, F.

374

Application of a Tractive Energy Analysis to Quantify the Benefits of Advanced Efficiency Technologies Using Characteristic Drive Cycle Data  

SciTech Connect

Accurately predicting the fuel savings that can be achieved with the implementation of various technologies developed for fuel efficiency can be very challenging, particularly when considering combinations of technologies. Differences in the usage of highway vehicles can strongly influence the benefits realized with any given technology, which makes generalizations about fuel savings inappropriate for different vehicle applications. A model has been developed to estimate the potential for reducing fuel consumption when advanced efficiency technologies, or combinations of these technologies, are employed on highway vehicles, particularly medium- and heavy-duty trucks. The approach is based on a tractive energy analysis applied to drive cycles representative of the vehicle usage, and the analysis specifically accounts for individual energy loss factors that characterize the technologies of interest. This tractive energy evaluation is demonstrated by analyzing measured drive cycles from a long-haul trucking fleet and the results of an assessment of the fuel savings potential for combinations of technologies are presented. The results of this research will enable more reliable estimates of the fuel savings benefits that can be realized with particular technologies and technology combinations for individual trucking applications so that decision makers can make informed investment decisions for the implementation of advanced efficiency technologies.

LaClair, Tim J [ORNL

2012-01-01

375

On the charge and energy spectrum of heavy primaries in cosmic radiation  

Microsoft Academic Search

Summary  529 tracks of heavy primaries in the cosmic radiation have been studied. Charge measurements have been carried out on all\\u000a tracks with a photometric method, and independent checks with gap counting have been performed on Boron and Carbon tracks.\\u000a All tracks have been followed through and a total of 331 nuclear collisions observed. From the analysis of these interactions,\\u000a the

R. Cester; A. Debenedetti; C. M. Garelli; B. Quassiati; L. Tallone; M. Vigone

1958-01-01

376

Rhabdomyosarcoma cells show an energy producing anabolic metabolic phenotype compared with primary myocytes  

Microsoft Academic Search

BACKGROUND: The functional status of a cell is expressed in its metabolic activity. We have applied stable isotope tracing methods to determine the differences in metabolic pathways in proliferating Rhabdomysarcoma cells (Rh30) and human primary myocytes in culture. Uniformly 13C-labeled glucose was used as a source molecule to follow the incorporation of 13C into more than 40 marker metabolites using

Teresa WM Fan; Magda Kucia; Kacper Jankowski; Richard M Higashi; Janina Ratajczak; Marius Z Ratajczak

2008-01-01

377

Recent world fossil fuel and primary energy production and consumption trends  

Microsoft Academic Search

This compilation of worldwide fossil-fuel and primary-electricity production statistics for 1972, 1976-79, and 1980-81 is based on the data published by several agencies. The total production for all the fuels showed no tendency to level off or decline until recently; preliminary data indicate a 7-8% drop in crude-oil production in 1981 from 1980. Data for other fuels in 1981 are

1982-01-01

378

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

Microsoft Academic Search

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

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

2010-01-01

379

Burnup calculation of fusion–fission hybrid energy system with thorium cycle  

Microsoft Academic Search

A fusion–fission hybrid reactor which is a fusion reactor with a blanket region containing nuclear fuel. In our group, a calculation system for analysis of fusion–fission hybrid reactor has been developed and various transport and burnup calculations were carried out for hybrid systems with U–Pu fuel cycle and ITER model so far. It was confirmed that such system is feasible

M. Matsunaka; S. Shido; K. Kondo; H. Miyamaru; I. Murata

2007-01-01

380

Ambient-RF-Energy-Harvesting Sensor Node with Capacitor-Leakage-Aware Duty Cycle Control  

E-print Network

methods for energy harvesting are discussing solar panels, wind power, and piezoelectric devices of the operation reliability and leakage reduction. I. INTRODUCTION Energy harvesting technologies such as solar panels, piezoelectric devices, thermocouples, and RF energy scavengers are attracting a great deal

Tentzeris, Manos

381

Specification and implementation of IFC based performance metrics to support building life cycle assessment of hybrid energy systems  

SciTech Connect

Minimizing building life cycle energy consumption is becoming of paramount importance. Performance metrics tracking offers a clear and concise manner of relating design intent in a quantitative form. A methodology is discussed for storage and utilization of these performance metrics through an Industry Foundation Classes (IFC) instantiated Building Information Model (BIM). The paper focuses on storage of three sets of performance data from three distinct sources. An example of a performance metrics programming hierarchy is displayed for a heat pump and a solar array. Utilizing the sets of performance data, two discrete performance effectiveness ratios may be computed, thus offering an accurate method of quantitatively assessing building performance.

Morrissey, Elmer; O'Donnell, James; Keane, Marcus; Bazjanac, Vladimir

2004-03-29

382

Life Cycle Assessment of the Energy Independence and Security Act of 2007: Ethanol - Global Warming Potential and Environmental Emissions  

SciTech Connect

The objective of this study is to use life cycle assessment (LCA) to evaluate the global warming potential (GWP), water use, and net energy value (NEV) associated with the EISA-mandated 16 bgy cellulosic biofuels target, which is assumed in this study to be met by cellulosic-based ethanol, and the EISA-mandated 15 bgy conventional corn ethanol target. Specifically, this study compares, on a per-kilometer-driven basis, the GWP, water use, and NEV for the year 2022 for several biomass feedstocks.

Heath, G. A.; Hsu, D. D.; Inman, D.; Aden, A.; Mann, M. K.

2009-07-01

383

Evaluating the species energy relationship with the newest measures of ecosystem energy: NDVI versus MODIS primary production  

Microsoft Academic Search

article i nfo Ecosystem energy has been shown to be a strong correlate with biological diversity at continental scales. Early efforts to characterize this association used the normalized difference vegetation index (NDVI) to represent ecosystem energy. While this spectral vegetation index covaries with measures of ecosystem energy such as netprimaryproduction,thecovariation isknowntodegradeinareasofverylowvegetationorinareasofdense forest. Two of the new vegetation products from the

Linda B. Phillips; Andrew J. Hansen; Curtis H. Flather

2008-01-01

384

Energy analysis of conventional and source-separation systems for urban wastewater management using Life Cycle Assessment.  

PubMed

This study investigates the cumulative energy demand (CED) of different systems for the management of urban wastewater, following the methodology of Life Cycle Assessment. In a hypothetical case study for an urban area (5,000 inhabitants), all relevant processes for wastewater collection and treatment and the construction of infrastructure are described in a substance flow model. The conventional system requires 1,250 MJ/(pe*a), with the operation contributing 45%, the infrastructure 7%, and the system expansion (production of mineral fertilizer and electricity) 48% to the total CED. The separation systems have a CED of 930-1,182 MJ/(pe*a) depending on their configuration. Results of the impact assessment show that recovering energy from the organic matter of toilet wastewater and household biowaste in a digestion process can decrease the cumulative energy demand by 13-26%. Energetic benefits of mineral fertilizer substitution are relatively small compared to the energy recovered from organic matter. Decisive parameters for the energy analysis are the amount of biowaste which is co-digested with toilet wastewater and the energy demand of the vacuum plant. PMID:22173404

Remy, C; Jekel, M

2012-01-01

385

Fuel-Cycle energy and emission impacts of ethanol-diesel blends in urban buses and farming tractors.  

SciTech Connect

About 2.1 billion gallons of fuel ethanol was used in the United States in 2002, mainly in the form of gasoline blends containing up to 10% ethanol (E10). Ethanol use has the potential to increase in the U.S. blended gasoline market because methyl tertiary butyl ether (MTBE), formerly the most popular oxygenate blendstock, may be phased out owing to concerns about MTBE contamination of the water supply. Ethanol would remain the only viable near-term option as an oxygenate in reformulated gasoline production and to meet a potential federal renewable fuels standard (RFS) for transportation fuels. Ethanol may also be blended with additives (co-solvents) into diesel fuels for applications in which oxygenation may improve diesel engine emission performance. Numerous studies have been conducted to evaluate the fuel-cycle energy and greenhouse gas (GHG) emission effects of ethanol-gasoline blends relative to those of gasoline for applications in spark-ignition engine vehicles (see Wang et al. 1997; Wang et al. 1999; Levelton Engineering et al. 1999; Shapouri et al. 2002; Graboski 2002). Those studies did not address the energy and emission effects of ethanol-diesel (E-diesel or ED) blends relative to those of petroleum diesel fuel in diesel engine vehicles. The energy and emission effects of E-diesel could be very different from those of ethanol-gasoline blends because (1) the energy use and emissions generated during diesel production (so-called ''upstream'' effects) are different from those generated during gasoline production; and (2) the energy and emission performance of E-diesel and petroleum diesel fuel in diesel compression-ignition engines differs from that of ethanol-gasoline blends in spark-ignition (Otto-cycle-type) engine vehicles. The Illinois Department of Commerce and Community Affairs (DCCA) commissioned Argonne National Laboratory to conduct a full fuel-cycle analysis of the energy and emission effects of E-diesel blends relative to those of petroleum diesel when used in the types of diesel engines that will likely be targeted first in the marketplace. This report documents the results of our study. The draft report was delivered to DCCA in January 2003. This final report incorporates revisions by the sponsor and by Argonne.

Wang, M.; Saricks, C.; Lee, H.

2003-09-11

386

Energy and emission benefits of alternative transportation liquid fuels derived from switchgrass: a fuel life cycle assessment.  

PubMed

We conducted a mobility chains, or well-to-wheels (WTW), analysis to assess the energy and emission benefits of cellulosic biomass for the U.S. transportation sector in the years 2015-2030. We estimated the life-cycle energy consumption and emissions associated with biofuel production and use in light-duty vehicle (LDV) technologies by using the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model. Analysis of biofuel production was based on ASPEN Plus model simulation of an advanced fermentation process to produce fuel ethanol/protein, a thermochemical process to produce Fischer-Tropsch diesel (FTD) and dimethyl ether (DME), and a combined heat and power plant to co-produce steam and electricity. Our study revealed that cellulosic biofuels as E85 (mixture of 85% ethanol and 15% gasoline by volume), FTD, and DME offer substantial savings in petroleum (66-93%) and fossil energy (65-88%) consumption on a per-mile basis. Decreased fossil fuel use translates to 82-87% reductions in greenhouse gas emissions across all unblended cellulosic biofuels. In urban areas, our study shows net reductions for almost all criteria pollutants, with the exception of carbon monoxide (unchanged), for each of the biofuel production option examined. Conventional and hybrid electric vehicles, when fueled with E85, could reduce total sulfur oxide (SO(x)) emissions to 39-43% of those generated by vehicles fueled with gasoline. By using bio-FTD and bio-DME in place of diesel, SO(x) emissions are reduced to 46-58% of those generated by diesel-fueled vehicles. Six different fuel production options were compared. This study strongly suggests that integrated heat and power co-generation by means of gas turbine combined cycle is a crucial factor in the energy savings and emission reductions. PMID:16889378

Wu, May; Wu, Ye; Wang, Michael

2006-01-01

387

Altered energy status of primary cerebellar granule neuronal cultures from rats exposed to lead in the pre- and neonatal period.  

PubMed

This paper examines the effect of pre- and neonatal exposure of rats to lead (0.1% lead acetate in drinking water, resulting in rat offspring whole blood lead concentration (Pb-B) 4?g/dL) on the energy status of neuronal mitochondria by measuring changes in ATP, ADP, AMP, adenosine, TAN concentration, adenylate energy charge value (AEC) and mitochondrial membrane potential in primary cerebellar granule neurons (CGC) in dissociated cultures. Fluorescence studies were performed to imaging and evaluate mitochondria mass, mitochondrial membrane potential, intracellular and mitochondrial reactive oxygen species (ROS) production. The Na(+)/K(+) ATPase activity in intact CGC was measured spectrophotometrically. Our data shows that pre- and neonatal exposure of rats to Pb, even below the threshold of whole blood Pb value considered safe for people, affects the energy status of cultured primary cerebellar granule neurons through a decrease in ATP and TAN concentrations and AEC value, inhibition of Na(+)/K(+) ATPase, and increase in intracellular and mitochondrial ROS concentration. These observations suggest that even these low levels of Pb are likely to induce important alterations in neuronal function that could play a role in neurodegeneration. PMID:21108985

Baranowska-Bosiacka, I; Gutowska, I; Marchetti, C; Rutkowska, M; Marchlewicz, M; Kolasa, A; Prokopowicz, A; Wiernicki, I; Piotrowska, K; Ba?kiewicz, M; Safranow, K; Wiszniewska, B; Chlubek, D

2011-02-01

388

Water Cycle Webquest  

NSDL National Science Digital Library

Students are introduced to the Global Precipitation Measurement (GPM) satellite mission and its role in studying the water cycle. This webquest provides links to eight websites, allowing middle school students to explore the water cycle and its impacts on Earth's weather and climate. Through online videos and articles, students follow a water molecule through the cycle, discover the connection between the water cycle and global water/heat distribution, examine the role of solar energy, and assess the importance of fresh water.

389

Annual cycle of energy and time expenditure in a golden-mantled ground squirrel population  

Microsoft Academic Search

We have analyzed seasonal shifts of energy and time allocation in a population of golden-mantled ground squirrels (Spermophilus saturatus) by directly measuring total daily energy expenditure (DEE) with an isotopic technique (“doubly labeled water”=dlw), and by estimating components of total DEE through an integration of field behavioral observations with laboratory-measured rates of energy expenditure (oxygen consumption) associated with major behavioral

G. J. Kenagy; S. M. Sharbaugh; K. A. Nagy

1989-01-01

390

Integrating Cell Cycle Progression, Drug Penetration and Energy Metabolism to Identify Improved Cancer Therapeutic Strategies  

PubMed Central

The effectiveness of chemotherapeutic drugs in tumors is reduced by multiple effects including drug diffusion and variable susceptibility of local cell populations. We hypothesized that quantifying the interactions between drugs and tumor microenvironments could be used to identify more effective anti-cancer strategies. To test this hypothesis we created a mathematical model that integrated intracellular metabolism, nutrient and drug diffusion, cell-cycle progression, cellular drug effects, and drug pharmacokinetics. To our knowledge, this is the first model that combines these elements and has coupled them to experimentally derived parameters. Drug cytotoxicity was assumed to be cell-cycle phase specific, and progression through the cell cycle was assumed to be dependent on ATP generation. The model consisted of a coupled set of nonlinear partial differential, ordinary differential and algebraic equations with an outer free boundary, which was solved using orthogonal collocation on a moving grid of finite elements. Model simulations showed the existence of an optimum drug diffusion coefficient: a low diffusivity prevents effective penetration before the drug is cleared from the blood and a high diffusivity limits drug retention. This result suggests that increasing the molecular weight of the anti-cancer drug paclitaxel from 854 to approximately 20,000 by nano-particle conjugation would improve its efficacy. The simulations also showed that fast growing tumors are less responsive to therapy than are slower tumors with more quiescent cells, demonstrating the competing effects of regrowth and cytotoxicity. The therapeutic implications of the simulation results are that 1) monolayer cultures are inadequate for accurately determining therapeutic effects in vitro, 2) decreasing the diffusivity of paclitaxel could increase its efficacy, and 3) measuring the proliferation fraction in tumors could enhance the prediction of therapeutic efficacy. PMID:18402980

Venkatasubramanian, Raja; Henson, Michael A.; Forbes, Neil S.

2008-01-01

391

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

E-print Network

that reducing the amount of reheat can save substantial steam (0.5 MMBtu/hr) and chilled water energy (0.5 MMBtu/hr) if problem associated with the room relative humidity could be solved by other measures. Texas State Energy Conservation Office Loan... that reducing the amount of reheat can save substantial steam (0.5 MMBtu/hr) and chilled water energy (0.5 MMBtu/hr) if problem associated with the room relative humidity could be solved by other measures. Texas State Energy Conservation Office Loan...

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

1993-01-01

392

The problem of optimizing the water chemistry used in the primary coolant circuit of a nuclear power station equipped with VVER reactors under the conditions of longer fuel cycle campaigns and increased capacity of power units  

NASA Astrophysics Data System (ADS)

It is shown that the optimal water chemistry of the primary coolant circuit must be substantiated while introducing measures aimed at increasing the power output in operating power units and for the project called AES-2006/AES TOI (a typical optimized project of a nuclear power station with enhanced information support). The experience gained from operation of PWR reactors with an elongated fuel cycle at an increased level of power is analyzed. Conditions under which boron compounds are locally concentrated on the fuel rod surfaces (the hideout phenomenon) and axial offset anomaly occurs are enlisted, and the influence of lithium on the hideout in the pores of deposits on the surfaces of fuel assemblies is shown.

Sharafutdinov, R. B.; Kharitonova, N. L.

2011-05-01

393

NV Energy Solar Integration Study: Cycling and Movements of Conventional Generators for Balancing Services  

SciTech Connect

With an increasing penetration level of solar power in the southern Nevada system, the impact of solar on system operations needs to be carefully studied from various perspectives. Qualitatively, it is expected that the balancing requirements to compensate for solar power variability will be larger in magnitude; meanwhile, generators providing load following and regulation services will be moved up or down more frequently. One of the most important tasks is to quantitatively evaluate the cycling and movements of conventional generators with solar power at different penetration levels. This study is focused on developing effective methodologies for this goal and providing a basis for evaluating the wear and tear of the conventional generators

Diao, Ruisheng; Lu, Shuai; Etingov, Pavel V.; Ma, Jian; Makarov, Yuri V.; Guo, Xinxin

2011-07-01

394

Numerical studies on the Impact of the Last Glacial Cycle on recent borehole temperature profiles: implications for terrestrial energy balance  

NASA Astrophysics Data System (ADS)

Reconstructions of past climatic changes from borehole temperature profiles are important independent estimates of temperature histories over the last millennium. There remain, however, multiple uncertainties in the interpretation of these data as climatic indicators and as estimates of the changes in the heat content of the continental subsurface due to long-term climatic change. One of these uncertainties is associated with the often ignored impact of the last glacial cycle (LGC) on the subsurface energy content, and on the estimate of the background quasi steady-state signal associated with the diffusion of accretionary energy from the Earth's interior. Here, we provide the first estimate of the impact of the development of the Laurentide ice sheet on the estimates of energy and temperature reconstructions from measurements of terrestrial borehole temperatures in North America. We use basal temperature values from the data-calibrated Memorial University of Newfoundland glacial systems model (MUN-GSM) to quantify the extent of the perturbation to estimated steady-state temperature profiles, and to derive spatial maps of the expected impacts on measured profiles over North America. Furthermore, we present quantitative estimates of the potential effects of temperature changes during the last glacial cycle on the borehole reconstructions over the last millennium for North America. The range of these possible impacts is estimated using synthetic basal temperatures for a period covering 120 ka to the present day that include the basal temperature history uncertainties from an ensemble of results from the calibrated numerical model. For all the locations, we find that within the depth ranges that are typical for available boreholes (?600 m), the induced perturbations to the steady-state temperature profile are on the order of 10 mW m-2, decreasing with greater depths. Results indicate that site-specific heat content estimates over North America can differ by as much as 50%, if the energy contribution of the last glacial cycle in those areas of North America that experienced glaciation is not taken into account when estimating recent subsurface energy changes from borehole temperature data.

Beltrami, H.; Matharoo, G. S.; Tarasov, L.; Rath, V.; Smerdon, J. E.

2014-09-01

395

Comparison of life cycle carbon dioxide emissions and embodied energy in four renewable electricity generation technologies in New Zealand.  

PubMed

In order to make the best choice between renewable energy technologies, it is important to be able to compare these technologies on the basis of their sustainability, which may include a variety of social, environmental, and economic indicators. This study examined the comparative sustainability of four renewable electricity technologies in terms of their life cycle CO2 emissions and embodied energy, from construction to decommissioning and including maintenance (periodic component replacement plus machinery use), using life cycle analysis. The models developed were based on case studies of power plants in New Zealand, comprising geothermal, large-scale hydroelectric, tidal (a proposed scheme), and wind-farm electricity generation. The comparative results showed that tidal power generation was associated with 1.8 g of CO2/kWh, wind with 3.0 g of CO2/kWh, hydroelectric with 4.6 g of CO2/kWh, and geothermal with 5.6 g of CO2/kWh (not including fugitive emissions), and that tidal power generation was associated with 42.3 kJ/kWh, wind with 70.2 kJ/kWh, hydroelectric with 55.0 kJ/kWh, and geothermal with 94.6 kJ/kWh. Other environmental indicators, as well as social and economic indicators, should be applied to gain a complete picture of the technologies studied. PMID:19746744

Rule, Bridget M; Worth, Zeb J; Boyle, Carol A

2009-08-15

396

Life cycle assessment of urban waste management: energy performances and environmental impacts. The case of Rome, Italy.  

PubMed

Landfilling is nowadays the most common practice of waste management in Italy in spite of enforced regulations aimed at increasing waste pre-sorting as well as energy and material recovery. In this work we analyse selected alternative scenarios aimed at minimizing the unused material fraction to be delivered to the landfill. The methodological framework of the analysis is the life cycle assessment, in a multi-method form developed by our research team. The approach was applied to the case of municipal solid waste (MSW) management in Rome, with a special focus on energy and material balance, including global and local scale airborne emissions. Results, provided in the form of indices and indicators of efficiency, effectiveness and environmental impacts, point out landfill activities as the worst waste management strategy at a global scale. On the other hand, the investigated waste treatments with energy and material recovery allow important benefits of greenhouse gas emission reduction (among others) but are still affected by non-negligible local emissions. Furthermore, waste treatments leading to energy recovery provide an energy output that, in the best case, is able to meet 15% of the Rome electricity consumption. PMID:18230413

Cherubini, Francesco; Bargigli, Silvia; Ulgiati, Sergio

2008-12-01

397

Life cycle assessment of urban waste management: Energy performances and environmental impacts. The case of Rome, Italy  

SciTech Connect

Landfilling is nowadays the most common practice of waste management in Italy in spite of enforced regulations aimed at increasing waste pre-sorting as well as energy and material recovery. In this work we analyse selected alternative scenarios aimed at minimizing the unused material fraction to be delivered to the landfill. The methodological framework of the analysis is the life cycle assessment, in a multi-method form developed by our research team. The approach was applied to the case of municipal solid waste (MSW) management in Rome, with a special focus on energy and material balance, including global and local scale airborne emissions. Results, provided in the form of indices and indicators of efficiency, effectiveness and environmental impacts, point out landfill activities as the worst waste management strategy at a global scale. On the other hand, the investigated waste treatments with energy and material recovery allow important benefits of greenhouse gas emission reduction (among others) but are still affected by non-negligible local emissions. Furthermore, waste treatments leading to energy recovery provide an energy output that, in the best case, is able to meet 15% of the Rome electricity consumption.

Cherubini, Francesco [Joanneum Research, Elisabethstrasse 5, 8010, Graz (Austria)], E-mail: cherufra@yahoo.it; Bargigli, Silvia; Ulgiati, Sergio [Universita degli Studi di Napoli 'Parthenope', Dipartimento di Scienze per l'Ambiente, Centro Direzionale, Isola C4, 80133 Napoli (Italy)

2008-12-15

398

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

SciTech Connect

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 and geochemical effects of high-temperature aquifer thermal energy storage. The third long-term cycle (LT3) was conducted to operate the ATES system in conjunction with a real heating load and to further study the geochemical impact that heated water storage had on the aquifer. For LT3, the source and storage wells were modified so that only the most permeable portion, the Ironton-Galesville part, of the Franconia-Ironton-Galesville aquifer was used for storage. This was expected to improve storage efficiency by reducing the surface area of the heated volume and simplify analysis of water chemistry results by reducing the number of aquifer-related variables which need to be considered. During LT3, a total volume of 63.2 {times} 10{sup 3} m {sup 3} of water was injected at a rate of 54.95 m{sup 3}/hr into the storage well at a mean temperature of 104.7{degrees}C. Tie-in to the reheat system of the nearby Animal Sciences Veterinary Medicine (ASVM) building was completed after injection was completed. Approximately 66 percent (4.13 GWh) of the energy added to the aquifer was recovered. Approximately 15 percent (0.64 GWh) of the usable (10 building. Operations during heat recovery with the ASVM building`s reheat system were trouble-free. Integration into more of the ASVM (or other) building`s mechanical systems would have resulted in significantly increasing the proportion of energy used during heat recovery.

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

1994-12-01

399

2D Excitons as Primary Energy Carriers in Organic Crystals: The Case of Oligoacenes  

E-print Network

A number of organic crystals show anisotropic excitonic couplings, with weak interlayer interactions between molecules that are more strongly coupled within the layers. The resulting energy carriers are intralayer 2D ...

Emelianova, E.V.

400

Dietary energy availability affects primary and metastatic breast cancer and metformin efficacy  

Microsoft Academic Search

Dietary energy restriction has been shown to repress both mammary tumorigenesis and aggressive mammary tumor growth in animal\\u000a studies. Metformin, a caloric restriction mimetic, has a long history of safe use as an insulin sensitizer in diabetics and\\u000a has been shown to reduce cancer incidence and cancer-related mortality in humans. To determine the potential impact of dietary\\u000a energy availability and

Kathryn N. Phoenix; Frank Vumbaca; Melissa M. Fox; Rebecca Evans; Kevin P. Claffey

2010-01-01

401

Sources d'énergie primaires et effet de serrePrimary energy sources and greenhouse effect  

NASA Astrophysics Data System (ADS)

In the frame of the diminution of fossil energy and climate change, the two most difficult demands to satisfy are providing electricity to megalopolises and fuels for transportation. Renewable energies have to be promoted but will not be able to replace fossil fuels in their current uses before several decades. According to the previsions for this century, carefulness is necessary to preserve the future of humanity and the environment. To cite this article: B. Tissot, C. R. Geoscience 335 (2003).

Tissot, Bernard

2003-06-01

402

Two contributions to the ratio of the mean secondary electron generation of backscattered electrons to primary electrons at high electron energy  

NASA Astrophysics Data System (ADS)

Based on the main physical processes of secondary electron emission, experimental results and the characteristics of backscattered electrons (BE), the formula was derived for describing the ratio (?angle) of the number of secondary electrons excited by the larger average angle of emission BE to the number of secondary electrons excited by the primary electrons of normal incidence. This ratio was compared to the similar ratio ? obtained in the case of high energy primary electrons. According to the derived formula for ?angle and the two reasons why ? > 1, the formula describing the ratio ?energy of ? to ?angle, reflecting the effect that the mean energy of the BE WAVp0 is smaller than the energy of the primary electrons at the surface, was derived. ?angle and ?energy computed using the experimental results and the deduced formulae for ?angle and ?energy were analyzed. It is concluded that ?angle is not dependent on atomic number z, and that ?energy decreases slowly with z. On the basis of the two reasons why ? > 1, the definitions of ? and ?energy and the number of secondary electrons released per primary electron, the formula for ?E-energy (the estimated ?energy) was deduced. The ?E-energy computed using WAVp0, energy exponent and the formula for ?E-energy is in a good agreement with ?energy computed using the experimental results and the deduced formula for ?energy. Finally, it is concluded that the deduced formulae for ?angle and ?energy can be used to estimate ?angle and ?energy, and that the factor that WAVp0 increases slowly with atomic number z leads to the results that ?energy decreases slowly with z and ? decreases slowly with z.

Xie, Ai-Gen; Zhang, Chen-Yi; Zhong, Kun

2014-02-01

403

Increasing energy expenditure for a deep-diving bird alters time allocation during the dive cycle  

Microsoft Academic Search

How foraging animals respond to changes in energy costs is poorly understood. Energy costs are especially important for central-place foragers because they determine transit costs as well as foraging costs. For ex- ample, oxygen consumption during diving determines the minimum surface pause for a given oxygen store, dive depth and dive duration. A theoretical model based on the marginal value

H AMISH E LLIOTT; G AIL K. DAVOREN; ANTHONY J. G ASTON

2008-01-01

404

CIRP International Conference on Life Cycle Engineering, Leuven, May 31 Electrical Energy Requirements for Manufacturing Processes  

E-print Network

them into products and wastes. Similarly, the energy inputs into these processes (primarily from of the products and wastes, and waste heat. In addition, the energy inputs usually require fuels and produce, but many other working materials, including pure metals, plastics and other organics, can have equally high

Gutowski, Timothy

405

Major Solar Eruptions and High Energy Particle Events during Solar Cycle 24  

E-print Network

We report on a study of all major solar eruptions that occurred on the front-side of the Sun during the rise to peak phase of cycle 24 (first 62 months) in order to understand the key factors affecting the occurrence of large solar energetic particle events (SEPs) and the ground levels enhancement (GLE) events. The eruptions involve major flares with soft X-ray peak flux >/= 5.0 x10-5 Wm-2 (i.e., flare size >/= M5.0) and accompanying coronal mass ejections (CMEs). The selection criterion was based on the fact that the only front-side GLE in cycle 24 (GLE 71) had a flare size of M5.1. Only ~37% of the major eruptions from the western hemisphere resulted in large SEP events. Almost the same number of large SEP events was produced in weaker eruptions (flare size

Gopalswamy, N; Akiyama, S; Makela, P; Yashiro, S

2014-01-01

406

Lkb1 regulates cell cycle and energy metabolism in haematopoietic stem cells  

PubMed Central

Summary Little is known about metabolic regulation in stem cells and how this modulates tissue regeneration or tumour suppression. We studied the Lkb1 tumour suppressor, and its substrate AMPK, kinases that coordinate metabolism with cell growth. Lkb1 deletion caused increased haematopoietic stem cell (HSC) division, rapid HSC depletion, and pancytopenia. HSCs depended more acutely on Lkb1 for cell cycle regulation and survival than many other haematopoietic cells. HSC depletion did not depend on mTOR activation or oxidative stress. Lkb1-deficient HSCs, but not myeloid progenitors, had reduced mitochondrial membrane potential and ATP. AMPK-deficient HSCs showed similar changes in mitochondrial function but remained able to reconstitute irradiated mice. Lkb1-deficient HSCs, but not AMPK-deficient HSCs, exhibited defects in centrosomes and mitotic spindles in culture, and became aneuploid. Lkb1 is therefore required for HSC maintenance through AMPK-dependent and AMPK-independent mechanisms, revealing differences in metabolic and cell cycle regulation between HSCs and some other haematopoietic progenitors. PMID:21124450

Nakada, Daisuke; Saunders, Thomas L.; Morrison, Sean J.

2010-01-01

407

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

E-print Network

Biomass Stove Pollution Sam Beck ATOC-3500 Biomass energy accounts for about 15% of the world. Furthermore, biomass often accounts for more than 90% of the total rural energy supplies in developing countries. The traditional stoves in developing countries waste a lot of biomass, mainly because

Toohey, Darin W.

408

Physics-based modelling of the life cycle of energy in the solar system  

NASA Astrophysics Data System (ADS)

Energy in the solar system is constantly being converted from one form to another. Often these processes take the form of dramatic events such as solar eruptions or geomagnetic storms with important societal impacts. Understanding energy conversion and magnetic storms is one of the grand challenges facing science and poses a great cultural and scientific puzzle. We plan to use a new modelling approach based on combining state of the art supercomputers with state of the art numerical methods that allow us to capture the key aspect in energy conversion: the interplay of small and large scales. At the core of energy conversion is the ability of macroscopic systems to store and process vast amounts of energy while at the same time requiring microscopic processes at the moment the energy is released. To describe and predict how energy can be stored for long periods and why it is then suddenly released, a complete description down to the level of tracking the trajectory of single particles is needed.

Lapenta, G.

2012-02-01

409

Energy harvesting from self-sustained aeroelastic limit cycle oscillations of rectangular wings  

NASA Astrophysics Data System (ADS)

Three different aspect-ratio rectangular wings are designed and experimentally tested to produce self-sustained aeroelastic oscillations for energy harvesting via implementing a piezoelectric generator. Sensitivity measurements are conducted first to determine the critical conditions producing such oscillations with a dominant frequency of 1 Hz. Furthermore, the energy harvesting performance is maximized as the piezoelectric generator is implemented in parallel with oncoming flow streamline. Approximately 55 mW electricity is produced from a wing with a surface area of 0.025 m2. Unlike conventional wind turbine technology, the present work opens up another possible way to harvest energy via nonlinear aeroelastic oscillations.

Zhao, Dan; Ega, Evan

2014-09-01

410

Life cycle energy and greenhouse gas analysis of a large-scale vertically integrated organic dairy in the United States.  

PubMed

In order to manage strategies to curb climate change, systemic benchmarking at a variety of production scales and methods is needed. This study is the first life cycle assessment (LCA) of a large-scale, vertically integrated organic dairy in the United States. Data collected at Aurora Organic Dairy farms and processing facilities were used to build a LCA model for benchmarking the greenhouse gas (GHG) emissions and energy consumption across the entire milk production system, from organic feed production to post-consumer waste disposal. Energy consumption and greenhouse gas emissions for the entire system (averaged over two years of analysis) were 18.3 MJ per liter of packaged fluid milk and 2.3 kg CO(2 )equiv per liter of packaged fluid milk, respectively. Methane emissions from enteric fermentation and manure management account for 27% of total system GHG emissions. Transportation represents 29% of the total system energy use and 15% of the total GHG emissions. Utilization of renewable energy at the farms, processing plant, and major transport legs could lead to a 16% reduction in system energy use and 6.4% less GHG emissions. Sensitivity and uncertainty analysis reveal that alternative meat coproduct allocation methods can lead to a 2.2% and 7.5% increase in overall system energy and GHG, respectively. Feed inventory data source can influence system energy use by -1% to +10% and GHG emission by -4.6% to +9.2%, and uncertainties in diffuse emission factors contribute -13% to +25% to GHG emission. PMID:21348530

Heller, Martin C; Keoleian, Gregory A

2011-03-01

411

Life-cycle-assessment of the historical development of air pollution control and energy recovery in waste incineration.  

PubMed

Incineration of municipal solid waste is a debated waste management technology. In some countries it is the main waste management option whereas in other countries it has been disregarded. The main discussion point on waste incineration is the release of air emissions from the combustion of the waste, but also the energy recovery efficiency has a large importance. The historical development of air pollution control in waste incineration was studied through life-cycle-assessment modelling of eight different air pollution control technologies. The results showed a drastic reduction in the release of air emissions and consequently a significant reduction in the potential environmental impacts of waste incineration. Improvements of a factor 0.85-174 were obtained in the different impact potentials as technology developed from no emission control at all, to the best available emission control technologies of today (2010). The importance of efficient energy recovery was studied through seven different combinations of heat and electricity recovery, which were modelled to substitute energy produced from either coal or natural gas. The best air pollution control technology was used at the incinerator. It was found that when substituting coal based energy production total net savings were obtained in both the standard and toxic impact categories. However, if the substituted energy production was based on natural gas, only the most efficient recovery options yielded net savings with respect to the standard impacts. With regards to the toxic impact categories, emissions from the waste incineration process were always larger than those from the avoided energy production based on natural gas. The results shows that the potential environmental impacts from air emissions have decreased drastically during the last 35 years and that these impacts can be partly or fully offset by recovering energy which otherwise should have been produced from fossil fuels like coal or natural gas. PMID:20378326

Damgaard, Anders; Riber, Christian; Fruergaard, Thilde; Hulgaard, Tore; Christensen, Thomas H

2010-07-01

412

Life-cycle-assessment of the historical development of air pollution control and energy recovery in waste incineration  

SciTech Connect

Incineration of municipal solid waste is a debated waste management technology. In some countries it is the main waste management option whereas in other countries it has been disregarded. The main discussion point on waste incineration is the release of air emissions from the combustion of the waste, but also the energy recovery efficiency has a large importance. The historical development of air pollution control in waste incineration was studied through life-cycle-assessment modelling of eight different air pollution control technologies. The results showed a drastic reduction in the release of air emissions and consequently a significant reduction in the potential environmental impacts of waste incineration. Improvements of a factor 0.85-174 were obtained in the different impact potentials as technology developed from no emission control at all, to the best available emission control technologies of today (2010). The importance of efficient energy recovery was studied through seven different combinations of heat and electricity recovery, which were modelled to substitute energy produced from either coal or natural gas. The best air pollution control technology was used at the incinerator. It was found that when substituting coal based energy production total net savings were obtained in both the standard and toxic impact categories. However, if the substituted energy production was based on natural gas, only the most efficient recovery options yielded net savings with respect to the standard impacts. With regards to the toxic impact categories, emissions from the waste incineration process were always larger than those from the avoided energy production based on natural gas. The results shows that the potential environmental impacts from air emissions have decreased drastically during the last 35 years and that these impacts can be partly or fully offset by recovering energy which otherwise should have been produced from fossil fuels like coal or natural gas.

Damgaard, Anders, E-mail: and@env.dtu.d [Department of Environmental Engineering, Technical University of Denmark, Miljoevej, Building 113, DK-2800 Kongens Lyngby (Denmark); Riber, Christian [Ramboll, Consulting Engineers, Teknikerbyen 31, DK-2830 Virum (Denmark); Fruergaard, Thilde [Department of Environmental Engineering, Technical University of Denmark, Miljoevej, Building 113, DK-2800 Kongens Lyngby (Denmark); Hulgaard, Tore [Ramboll, Consulting Engineers, Teknikerbyen 31, DK-2830 Virum (Denmark); Christensen, Thomas H. [Department of Environmental Engineering, Technical University of Denmark, Miljoevej, Building 113, DK-2800 Kongens Lyngby (Denmark)

2010-07-15

413

Use and abuse of driving cycle research: clarifying the relationship between traffic congestion, energy, and emissions  

SciTech Connect

The authors review research on vehicle driving patterns that began during the 1950s and now includes several internationally accepted driving cycles that reduce urban driving patterns to relationships of speed, fuel consumption, and emissions. The data collected from this type of research, they conclude, is useful in assessing new engines, new fuels, vehicle extras, and the establishment of fuel economy and emission regulations. To use it as a basis for policies on the wider macro level of traffic management, however, is subject to criticism, although it is possible to use driving pattern research in broader urban policy matters as long as it relates to wider land use and socio-economic variables that characterize the city. 37 references, 4 figures, 2 tables.

Newman, P.W.G.; Kenworthy, J.R.

1984-10-01

414

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

E-print Network

exergy value per unit of heat CQuid have been used. e. Using fuel to heat the entering combustion air, which Is at ambient temperature. The foregoing observations are qualitative rather than quantitative, and even without quantification they can... not -- the 2nd law concept, exergy, does .- represent ?potentlal to cause change: Nevertheless, energy is an important scientific concept. It Is a key to the modelling of natural phenomena and systems. (By no means do we advocate replacing ?energy analysis...

Sama, D.; Sanhong, Q.

415

Comparative life cycle assessment of uses of rice husk for energy purposes  

Microsoft Academic Search

Purpose  Recently, the Thai government has been advancing the expanded use of biomass as an alternative source of energy substituting\\u000a it for the fossil fuels that have been shown to be harmful to the environment. Rice husk, one of the main sources of biomass\\u000a in Thailand, has already been used as an energy source in many different applications and has been

Jittima Prasara-A; Tim Grant

2011-01-01

416

Conceptual design of an open-cycle ocean thermal energy conversion net power-producing experiment (OC-OTEC NPPE)  

SciTech Connect

This report describes the conceptual design of an experiment to investigate heat and mass transfer and to assess the viability of open-cycle ocean thermal energy conversion (OC-OTEC). The experiment will be developed in two stages, the Heat- and Mass-Transfer Experimental Apparatus (HMTEA) and the Net Power-Producing Experiment (NPPE). The goal for the HMTEA is to test heat exchangers. The goal for the NPPE is to experimentally verify OC-OTEC's feasibility by installing a turbine and testing the power-generating system. The design effort met the goals of both the HMTEA and the NPPE, and duplication of hardware was minimal. The choices made for the design resource water flow rates are consistent with the availability of cold and warm seawater as a result of the seawater systems upgrade carried out by the US Department of Energy (DOE), the state of Hawaii, and the Pacific International Center for High Technology Research. The choices regarding configuration of the system were made based on projected performance, degree of technical risk, schedule, and cost. The cost for the future phase of the design and the development of the HMTEA/NPPE is consistent with the projected future program funding levels. The HMTEA and NPPE were designed cooperatively by PICHTR, Argonne National Laboratory, and Solar Energy Research Institute under the guidance of DOE. The experiment will be located at the DOE's Seacoast Test Facility at the Natural Energy Laboratory of Hawaii, Kailua-Kona, Hawaii. 71 refs., 41 figs., 34 tabs.

Bharathan, D.; Green, H.J.; Link, H.F.; Parsons, B.K.; Parsons, J.M.; Zangrando, F.

1990-07-01

417

Conceptual design of an Open-Cycle Ocean Thermal Energy Conversion Net Power-Producing Experiment (OC-OTEC NPPE)  

NASA Astrophysics Data System (ADS)

This report describes the conceptual design of an experiment to investigate heat and mass transfer and to assess the viability of open-cycle ocean thermal energy conversion (OC-OTEC). The experiment will be developed in two stages, the Heat- and Mass-Transfer Experimental Apparatus (HMTEA) and the Net Power-Producing Experiment (NPPE). The goal for the HMTEA is to test heat exchangers. The goal for the NPPE is to experimentally verify OC-OTEC's feasibility by installing a turbine and testing the power-generating system. The design effort met the goals of both the HMTEA and the NPPE, and duplication of hardware was minimal. The choices made for the design resource water flow rates are consistent with the availability of cold and warm seawater as a result of the seawater systems upgrade carried out by the U.S. Department of Energy (DOE), the state of Hawaii, and the Pacific International Center for High Technology Research. The choices regarding configuration of the system were made based on projected performance, degree of technical risk, schedule, and cost. The cost for the future phase of the design and the development of the HMTEA/NPPE is consistent with the projected future program funding levels. The HMTEA and NPPE were designed cooperatively by PICHTR, Argonne National Laboratory, and Solar Energy Research Institute under the guidance of DOE. The experiment will be located at the DOE's Seacoast Test Facility at the Natural Energy Laboratory of Hawaii, Kailua-Kona, Hawaii.

Bharathan, D.; Green, H. J.; Link, H. F.; Parsons, B. K.; Parsons, J. M.; Zangrando, F.

1990-07-01

418

Effects of ethanol on vehicle energy efficiency and implications on ethanol life-cycle greenhouse gas analysis.  

PubMed

Bioethanol is the world's largest-produced alternative to petroleum-derived transportation fuels due to its compatibility within existing spark-ignition engines and its relatively mature production technology. Despite its success, questions remain over the greenhouse gas (GHG) implications of fuel ethanol use with many studies showing significant impacts of differences in land use, feedstock, and refinery operation. While most efforts to quantify life-cycle GHG impacts have focused on the production stage, a few recent studies have acknowledged the effect of ethanol on engine performance and incorporated these effects into the fuel life cycle. These studies have broadly asserted that vehicle efficiency increases with ethanol use to justify reducing the GHG impact of ethanol. These results seem to conflict with the general notion that ethanol decreases the fuel efficiency (or increases the fuel consumption) of vehicles due to the lower volumetric energy content of ethanol when compared to gasoline. Here we argue that due to the increased emphasis on alternative fuels with drastically differing energy densities, vehicle efficiency should be evaluated based on energy rather than volume. When done so, we show that efficiency of existing vehicles can be affected by ethanol content, but these impacts can serve to have both positive and negative effects and are highly uncertain (ranging from -15% to +24%). As a result, uncertainties in the net GHG effect of ethanol, particularly when used in a low-level blend with gasoline, are considerably larger than previously estimated (standard deviations increase by >10% and >200% when used in high and low blends, respectively). Technical options exist to improve vehicle efficiency through smarter use of ethanol though changes to the vehicle fleets and fuel infrastructure would be required. Future biofuel policies should promote synergies between the vehicle and fuel industries in order to maximize the society-wise benefits or minimize the risks of adverse impacts of ethanol. PMID:23627549

Yan, Xiaoyu; Inderwildi, Oliver R; King, David A; Boies, Adam M

2013-06-01

419

Alternative primary energy for power desalting plants in Kuwait: the nuclear option I  

Microsoft Academic Search

Some countries (e.g. Korea, China, India, Pakistan, Japan) were forced to adopt the nuclear energy option to generate electric power Ep (by nuclear power plants NPP) and desalt seawater D (by nuclear desalination ND) due to the rising cost of fossil fuel and its insecure supply. The increase of fuel oil consumption and cost (more than $100 per barrel) motivate

M. A. Darwisha; Fatima M. Al-Awadhi; Ali Akbar; Ali Darwish

2009-01-01

420

Recent world fossil-fuel and primary energy production and consumption trends  

Microsoft Academic Search

Statistics on trends in world energy production and consumption are presented in nine tables. A description and explanation of the data sources notes areas of discrepancy, especially in respect to individual countries. The information covers the world daily average crude oil production for 1977 to 1980 and the annual production and consumption of natural gas, oil, natural gas liquids and

1980-01-01

421

Primary Isotope Yields and Characteristic Properties of the Fragmenting Source in Heavy-ion Reactions near the Fermi Energies  

E-print Network

For central collisions of $^{40}$Ca $+ ^{40}$Ca at 35 MeV/nucleon, the density and temperature of a fragmenting source have been evaluated in a self-consistent manner using the ratio of the symmetry energy coefficient relative to the temperature, $a_{sym}/T$, extracted from the yields of primary isotopes produced in antisymmetrized molecular dynamics (AMD) simulations. The $a_{sym}/T$ values are extracted from all isotope yields using an improved method based on the Modified Fisher Model (MFM). The values of $a_{sym}/T$ obtained, using different interactions with different density dependencies of the symmetry energy term, are correlated with the values of the symmetry energies at the density of fragment formation. Using this correlation, the fragment formation density is found to be $\\rho/\\rho_0 = 0.67 \\pm 0.02$. Using the input symmetry energy value for each interaction temperature values are extracted as a function of isotope mass $A$. The extracted temperature values are compared with those evaluated from the fluctuation thermometer with a radial flow correction.

X. Liu; W. Lin; R. Wada; M. Huang; Z. Chen; G. Q. Xiao; S. Zhang; X. Jin; J. Liu; F. Shi; P. Ren; H. Zheng; J. B. Natowitz; A. Bonasera

2014-04-23

422

The xanthophyll cycle of Mantoniella squamata converts violaxanthin into antheraxanthin but not to zeaxanthin: consequences for the mechanism of enhanced non-photochemical energy dissipation  

Microsoft Academic Search

.   The prasinophycean alga Mantoniella squamata uses in vivo an incomplete violaxanthin cycle. Although the violaxanthin cycle in Mantoniella is capable of converting violaxanthin to zeaxanthin, in intact cells only antheraxanthin accumulates during periods of strong\\u000a illumination. Antheraxanthin enhances non-photochemical quenching of chlorophyll fluorescence. Inhibition of antheraxanthin\\u000a synthesis by the de-epoxidase inhibitor dithiothreitol abolishes increased thermal energy dissipation. Antheraxanthin-dependent\\u000a non-photochemical

Reimund Goss; Karen Böhme; Christian Wilhelm

1998-01-01

423

A life-cycle analysis on thin-film CdS\\/CdTe PV modules  

Microsoft Academic Search

Authors have evaluated the life cycle of a thin-film CdS\\/CdTe PV module to estimate the energy payback time (EPT) and the life-cycle CO2 emissions of a residential rooftop PV system using the CdS\\/CdTe PV modules. The primary energy requirement for producing 1m2 of the CdS\\/CdTe PV module was similar to a-Si PV module at annual production scale of 100MW. EPT

Kazuhiko Kato; Takeshi Hibino; Keiichi Komoto; Seijiro Ihara; Shuji Yamamoto; Hideaki Fujihara

2001-01-01

424

Laser-induced Magnesium Production from Magnesium Oxide for Renewable Magnesium Energy Cycle.  

NASA Astrophysics Data System (ADS)

We succeeded in reducing magnesium [Mg] from magnesium oxide [MgO] by laser irradiation. The laser-induced vapor temperature was measured to be approximately 5000 K on the irradiating spot, where MgO separated into Mg and oxygen [O] atoms through thermal dissociation. The Mg vapor was intercepted a cooper plate, forming solid deposits on it. However, the presence of oxygen, resulting from MgO dissociation, leads to Mg oxidization in the course of vapor cooling. The deoxidization process results in lower Mg fraction in the deposits and degrades energy recovery efficiency from laser irradiation. To quench this recombination, we also employed silicon as reducing agents to capture oxygen in favor of Mg extraction. In these experiments, the molar ratio effect (MgO:Si = 1:0-1) on the magnesium fractions and energy efficiencies were measured by means of a chemical reaction. The maximal energy efficiency, %, was obtained at the ratio of MgO:Si = 1:0.5. This ratio is lower than that of the Pidgeon process with Mg:Si = 1:1 resulting in a lower energy efficiency of %. This implies laser-induced Mg production is a economical process of using reducing agents with large throughput. The usage of laser radiation generated from solar energy for Mg metallurgy will significantly reduce CO2 emission.

Liao, Shi-Hua; Yabe, Takashi; Baasandash, Choijil; Sato, Yuji; Ichikawa, Masashi; Nakatsuka, Masashi; Fukushima, Chika; Uchida, Shigeaki; Ohkubo, Tomomasa

2010-10-01

425

Synthesis of a Model System for the Primary Energy Conversion Reactions in Photosynthesis  

Microsoft Academic Search

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 multi-molecular layer of Zn(II)-tetraphenylporphyrin deposited on a clean aluminum surface and immersed in an aqueous mixture of potassium ferri-

Jui H. Wang

1969-01-01

426

Life cycle greenhouse gases, energy and cost assessment of automobiles using magnesium from Chinese Pidgeon process  

Microsoft Academic Search

Magnesium (Mg) has a great potential to reduce vehicle weight, fuel consumption, and greenhouse gas emissions. The Chinese Mg industry has developed rapidly since the 1990s. The output of Mg reached 700,000tons in 2006, accounting for more than 70% of global Mg production. Most of Mg is produced in China through the Pidgeon process that has an intensive energy usage

Jindan Du; Weijian Han; Yinghong Peng

2010-01-01

427

A Sustainable Nuclear Fuel Cycle Based on Laser Inertial Fusion Energy  

Microsoft Academic Search

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

E Moses; T Diaz de la Rubia; E Storm; J Latkowski; J Farmer; R Abbott; K Kramer; P Peterson; H Shaw; R Lehman II

2009-01-01

428

Thermodynamics -2 A cogeneration plant (plant which provides both electricity and thermal energy) executes a cycle  

E-print Network

Thermodynamics - 2 A cogeneration plant (plant which provides both electricity and thermal energy at P3 = 30 kPa. All components of the plant are well insulated, pressure drops in heat exchangers plant using the same heat source and heat sinks. e. [25 pts] Determine the minimum rate of heat input

Virginia Tech

429

Dynamics and Energy Balance in Stellar Transition Regions Cycle 3 Augmentation - Missing Exposure  

NASA Astrophysics Data System (ADS)

We will observe with 80,000 spectral resolution the stellar Lyman alpha emission line and interstellar hydrogen and deuterium absorption towards local late-type stars to derive the H and D column densities and D/H ratios along different lines of sight. High resolution (90,000) spectra of the MgII and FeII lines will help determine the interstellar line broadening and whether material along each line of sight has more than one velocity component. This is critical for accurate measurements of D/H, because both the D and H lines are on or near the flat part of the curve of growth. Previous IUE and Copernicus observations, which had low signal/noise and inadequate spectral resolution, provided very crude D/H values and suggested that the D/H ratio may vary within a few parsecs of the Sun. We will measure D/H with at least one order of magnitude improved precision and determine whether the proposed local variations are real. The local value(s) of D/H may be extrapolated to zero metal abundance to estimate the primordial value, which is valuable for constraining cosmological models. THIS PHASE II IS FOR OBSERVATION OF AN UNSCHEDULED CYCLE3 LYMAN ALPHA OBSERVATION OF HR1099 AT ORBITAL PHASE 0.75.

Linsky, Jeffrey

1994-01-01

430

Report of the Fuel Cycle Research and Development Subcommittee of the Nuclear Energy Advisory Committee  

SciTech Connect

The Fuel Cycle (FC) Subcommittee of NEAC met February 7-8, 2012 in Washington (Drs. Hoffmann and Juzaitis were unable to attend). While the meeting was originally scheduled to occur after the submission of the President’s FY 2013 budget, the submission was delayed a week; thus, we could have no discussion on balance in the NE program. The Agenda is attached as Appendix A. The main focus of the meeting was on accident tolerant fuels, an important post Fukushima issue, and on issues related to the report of the Blue Ribbon Commission on America’s Nuclear Future (BRC) as related to the responsibility for used fuel disposal which was assigned to the FC program with the end of the Office of Civilian Radioactive Waste Management. In addition we heard an update on the systems study program which is aimed at helping chose the best options for advanced reactors, and possible new study on separation and waste form relevance to used fuel disposal (these two items are only discussed in this section of the report).

Richter, Burton; Chu, Margaret; Hoffman, Darleane; Juzaitis, Ray; Mtingwa, Sekazi; Omberg, Ronald P.; Rempe, Joy L.; Warin, Dominique

2012-06-12

431

Open-cycle desiccant air conditioning as an alternative to vapor compression cooling in residential applications  

Microsoft Academic Search

The performance of open-cycle desiccant air conditioners for residential applications is evaluated. The performance of these systems is compared to that of vapor compression air conditioners on the basis of primary energy use and cost. Systems with improved dehumidifiers can achieve seasonal COP's on the order of 1.1. These systems, when coupled with a solar