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1

A Solar Energy Cycle  

NSDL National Science Digital Library

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

Childs, Gregory

2007-03-01

2

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

3

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

4

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

5

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

6

The NASA Energy and Water cycle Study  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

7

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

8

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

9

Toxicity of redox cycling pesticides in primary mesencephalic cultures.  

PubMed

A loss of nigrostriatal dopaminergic neurons is the primary neurodegenerative feature of Parkinson's disease. Paraquat, a known redox cycling herbicide, has recently been shown to kill selectively nigrostriatal dopaminergic cells in the mouse model. The purpose of this study was to test the ability of paraquat and other redox cycling pesticides to damage dopaminergic neurons in primary mesencephalic cultures. Addition of paraquat, diquat, or benzyl viologen to mesencephalic cultures induced morphological changes (e.g., dystrophic neuronal processes) consistent with dopaminergic cell injury. The three pesticides also caused cell death as assessed by a reduction of the number of tyrosine hydroxylase-immunoreactive neurons and a dose-dependent decrease in [(3)H]dopamine uptake. Quite interestingly, diquat and benzyl viologen were significantly more toxic than paraquat, probably reflecting their more pronounced ability to trigger redox cycling reactions. The data support a role of redox cycling as a mechanism of dopaminergic cell degeneration and suggest that the property of redox cycling should be taken into consideration when evaluating putative environmental risk factors for Parkinson's disease. PMID:15890009

Bonneh-Barkay, Dafna; Langston, William J; Di Monte, Donato A

2005-01-01

10

Adaptive duty cycling for energy harvesting systems  

Microsoft Academic Search

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

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

2006-01-01

11

Life cycle assessment of overhead and underground primary power distribution.  

PubMed

Electrical power can be distributed in overhead or underground systems, both of which generate a variety of environmental impacts at all stages of their life cycles. While there is considerable literature discussing the trade-offs between both systems in terms of aesthetics, safety, cost, and reliability, environmental assessments are relatively rare and limited to power cable production and end-of-life management. This paper assesses environmental impacts from overhead and underground medium voltage power distribution systems as they are currently built and managed by Southern California Edison (SCE). It uses process-based life cycle assessment (LCA) according to ISO 14044 (2006) and SCE-specific primary data to the extent possible. Potential environmental impacts have been calculated using a wide range of midpoint indicators, and robustness of the results has been investigated through sensitivity analysis of the most uncertain and potentially significant parameters. The studied underground system has higher environmental impacts in all indicators and for all parameter values, mostly due to its higher material intensity. For both systems and all indicators the majority of impact occurs during cable production. Promising strategies for impact reduction are thus cable failure rate reduction for overhead and cable lifetime extension for underground systems. PMID:20553042

Bumby, Sarah; Druzhinina, Ekaterina; Feraldi, Rebe; Werthmann, Danae; Geyer, Roland; Sahl, Jack

2010-07-15

12

The NASA Energy and Water cycle Study  

Microsoft Academic Search

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,

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

2010-01-01

13

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.

14

Interfacing primary heat sources and cycles for thermochemical hydrogen production  

NASA Astrophysics Data System (ADS)

It is pointed out that an efficient utilization of heat from high-temperature heat sources in processes, which employ thermochemical cycles to obtain hydrogen from water, can be achieved only if the reaction temperatures and heat requirements of the cycle match the maximum temperature and heat delivery characteristics of the heat source. An investigation is, therefore, conducted regarding the criteria for ideal cycles in terms of their potential for practical adaptation to available heat sources. Attention is given to a method for selecting cycles for specific maximum temperatures in terms of thermodynamic criteria for 'ideal' cycles, the heat source characteristics, the direct decomposition of H2O and CO2, oxide decomposition cycles, sulfuric acid - metal sulfate cycles, alternate sulfate cycles, and low temperature cycles.

Bowman, M. G.

15

Energy flow, nutrient cycling, and ecosystem resilience  

Microsoft Academic Search

The resilience, defined here as the speed with which a system returns to equilibrium state following a perturbation, is investigated for both food web energy models and nutrient cycling models. Previous simulation studies of food web energy models have shown that resilience increases as the flux of energy through the food web per unit amount of energy in the steady

DeAngelis

1980-01-01

16

Cataplerotic TCA cycle flux determined as glutamate-sustained oxygen consumption in primary cultures of astrocytes.  

PubMed

Utilization of glucose by adult brain as its metabolic substrate does not mean that glutamate cannot be synthesized from glucose and subsequently oxidatively degraded. Between 10 and 20% of total pyruvate metabolism in brain occurs as formation of oxaloacetate (OAA), a tricarboxylic acid (TCA) cycle intermediate, from pyruvate plus CO(2). This anaplerotic ('pool-filling') process occurs in astrocytes, which in contrast to neurons express pyruvate carboxylase (PC) activity. Equivalent amounts of pyruvate are converted to acetylcoenzyme A and condensed with oxaloacetate to form citrate (Cit), which is metabolized to alpha-ketoglutarate (generating oxidatively-derived energy), glutamate and glutamine and transferred to neurons in the glutamate-glutamine cycle and used as precursor for transmitter glutamate. Since the blood-brain barrier is poorly permeable to glutamate and its metabolites, net synthesis of glutamate must be followed by degradation of equivalent amounts of glutamate, a cataplerotic ('pool-emptying') process, in which glutamate is converted in the TCA cycle to malate or oxaloacetate (generating additional energy), which exit the cycle to form one molecule pyruvate. To obtain an estimate of the rate of astrocytic oxidation of glutamate the rate of oxygen consumption was measured in primary cultures of mouse astrocytes metabolizing glutamate in the absence of other metabolic substrates. The observed rate is compatible with complete oxidative degradation of glutamate. PMID:12742079

Hertz, Leif; Hertz, Elna

2003-01-01

17

Cycle of Waste Heat Energy Transformation.  

National Technical Information Service (NTIS)

Transformation of industrial waste heat with temperatures up to 300 C into mechanical or electrical energy using organic Rankine cycles technique is considered. Behavior of working fluid was studied and plant components were optimized. A pilot plant (gene...

H. Bormann C. Voneynatten R. Krause W. Rudolph G. Gneuss

1983-01-01

18

Solar energy storage within the absorption cycle  

Microsoft Academic Search

Solar energy storage may be achieved within the absorption cycle using the considerable energy required to separate a refrigerant from an absorbent solution. The stored energy can be recovered by the highly exothermic absorption of the refrigerant in a weak absorbent solution. Storage of the refrigerant, weak absorbent solution, and the strong absorbent solution is required. While this is more

J. Baughn; A. Jackman

1974-01-01

19

Life cycle optimization of building energy systems  

NASA Astrophysics Data System (ADS)

A life cycle optimization model intended to potentially reduce the environmental impacts of energy use in commercial buildings is presented. A combination of energy simulation, life cycle assessment, and operations research techniques are used to develop the model. In addition to conventional energy systems, such as the electric grid and a gas boiler, cogeneration systems which concurrently generate power and heat are investigated as an alternative source of energy. Cogeneration systems appeared to be an attractive alternative to conventional systems when considering life cycle environmental criteria. Internal combustion engine and microturbine (MT) cogeneration systems resulted in a reduction of up to 38% in global warming potential compared with conventional systems, while solid oxide fuel cell and MT cogeneration systems resulted in a reduction of up to 94% in tropospheric ozone precursor potential (TOPP). Results include a Pareto-optimal frontier between reducing costs and reducing the selected environmental indicators.

Osman, Ayat; Norman, Bryan; Ries, Robert

2008-02-01

20

NEED Project: Primary Science of Energy Infobook  

NSDL National Science Digital Library

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

21

On the free energy of solar cycles  

NASA Astrophysics Data System (ADS)

The total power of the solar electromagnetic radiation varies during the solar cycle with a relative amplitude of an order of 10-3 . The physical nature of these variations is not known. The free energy involved could be of different kinds: nuclear, gravity, mechanical motions (differential rotation, convection), radiative transports, heat, magnetic fields. The corresponding energy reservoirs and powers are estimated. The possible free energy recuperation and transformation processes are discussed. It is often assumed in the current literature that the solar activity processes related to the magnetic energy dissipation are sufficient to explain the observed variations of the total solar irradiance with its excess at solar maxima. Based on the energy estimates, we suggest the arguments favoring the opposite cause-sequence chain: the given luminosity variations are considered as the free energy drivers for the solar activity manifestations and cycles. The main open question is formulated as follows: what are the energy, momentum and mass distributions and their fluxes in space and time on the Sun during the cycles?

Veselovsky, I.

22

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

23

Note on the Primary Energy Spectrum.  

National Technical Information Service (NTIS)

The Mt. Chacaltaya air shower array in Bolivia has been used to collect data suitable for deriving the primary energy spectrum above 10 to the 14th power eV. The spectrum was reported at the London Conference (Bradt et al. 1966). Since that time the array...

M. La Pointe K. Kamata J. F. Gaebler I. V. Escobar V. Domingo

1967-01-01

24

Absence of primary cilia in cell cycle-arrested human breast cancer cells.  

PubMed

Previous studies using cultured cells showed that primary cilia are present in quiescent cells, but are absent in proliferating cells. We studied here the relationship between the presence or absence of primary cilia and the cell cycle arrest of normal epithelial cells and cancer cells in the human normal breast and breast cancer tissues. In normal breast tissues, although most epithelial cells were nonproliferating as estimated by the immunofluorescence staining of the proliferation marker Ki-67, primary cilia were present only in 20-40% of the epithelial cells. In breast cancer tissues, primary cilia were not observed in any of the breast cancer cells. Furthermore, primary cilia were hardly observed in the nonproliferating cancer cells in the orthotopic and metastatic human breast cancer xenograft tumors in mice. These results indicate that the absence of primary cilia does not necessarily represent the proliferating phases of normal epithelial cells and cancer cells. PMID:24330390

Nobutani, Kentaro; Shimono, Yohei; Yoshida, Midori; Mizutani, Kiyohito; Minami, Akihiro; Kono, Seishi; Mukohara, Toru; Yamasaki, Takashi; Itoh, Tomoo; Takao, Shintaro; Minami, Hironobu; Azuma, Takeshi; Takai, Yoshimi

2014-02-01

25

Life cycle energy analysis of fiber-reinforced composites  

Microsoft Academic Search

Life cycle assessment is a technique to assess environmental aspects associated with a product or process by identifying energy, materials, and emissions over its life cycle. The energy analysis includes four stages of a life cycle: material production phase, manufacturing phase, use phase, and end-of-life phase. In this study, the life cycle energy of fiber-reinforced composites manufactured by using the

Young S. Song; Jae R. Youn; Timothy G. Gutowski

2009-01-01

26

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

27

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

National Technical Information Service (NTIS)

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

A. Imazu

1980-01-01

28

Radiation energy receiver for high performance energy conversion cycles  

Microsoft Academic Search

Blackbody receivers, which are used to collect the high intensity radiation flux in solar power plants, are limited in performance and confined to low temperature applications. In this study, a novel type of radiation receiver is presented, in which the radiation energy is directly transferred to the working fluid of a thermodynamic cycle through volumetric absorption. The characteristics of such

Rault

1983-01-01

29

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

30

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

31

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

Microsoft Academic Search

Skillful predictions of water and energy cycle extremes (flood and drought) are elusive. To better understand the mechanisms responsible for water and energy extremes, and to make decisive progress in predicting these extremes, the collaborative NASA Energy and Water cycle Extremes (NEWSE) Integration Project, is studying these extremes in the U.S. Southern Great Plains (SGP) during 2006-2007, including their relationships

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

2008-01-01

32

Life Cycle Optimization of Extremely Low Energy Buildings  

Microsoft Academic Search

SUMMARY A global methodology is developed to optimize concepts for extremely low energy dwellings, taking into account energy savings, environmental impact and financial costs over the life cycle of the buildings. Energy simulations are executed with TRNSYS. The ecological impact is evaluated through a life cycle inventory of the whole building, whereas costs are evaluated through a cost-benefit analysis. The

Griet Verbeeck; Hugo Hens

2010-01-01

33

Life Cycle Optimization of Extremely Low Energy Dwellings  

Microsoft Academic Search

A global methodology is developed to optimize concepts for extremely low energy dwellings, taking into account energy use, environmental impact, and financial costs over the life cycle of the buildings. Energy simulations are executed with TRNSYS. The ecological impact is evaluated through a life cycle inventory of the whole building, whereas costs are evaluated through a cost-benefit analysis. The multi-objective

Griet Verbeeck; Hugo Hens

2007-01-01

34

Integration of MODIS-LAI with Sim-CYCLE to Estimate the Net Primary Productivity  

NASA Astrophysics Data System (ADS)

Net primary production (NPP) is a key component of the global carbon cycle. Among the pools and fluxes that make up the cycle, NPP accounts most of the annual carbon fluxes between the atmosphere and biosphere. To improve our understanding and estimating the NPP accurately at various spatial and temporal scales, there is a need for integration of multiple, complementary and independent methods and datasets. In this context, an ecosystem model plays an important role in synthesizing such desperate time/space data into single coherent analysis of terrestrial carbon fluxes. However, such models require a large number of biophysical and climatic parameters over a large area and their applicability to operational level is often limited by the fundamental drawback of large input parameter requirements. This is especially true for the parameters describing vegetation composition and structure, such as leaf area index (LAI), which is generally highly variable over space and time, and difficult to measure with conventional methods. However, recent advances in remote sensing, both in terms of new sensors (e.g., MODIS) as well as algorithm development for data processing have shown a promising future and now it is possible to do near real-time monitoring of the important biophysical parameters of vegetations like LAI to input into an ecosystem model. The current study aimed at the possibility of integrating remote sensing data to a processed based ecosystem model driven by conventional data. The ecosystem model selected for this study is Sim-CYCLE due to its portability for integrating data from different sources. Sim-CYCLE model is based on the dry-matter production theory and integrates ecophysiological findings into a simple scheme of plant growth to achieve the scaling-up from single-leaf to canopy level. The LAI derived from MODIS sensor (MODIS-LAI) was integrated with Sim-CYCLE and the model was renamed as MOD-Sim-CYCLE. Global annual NPP was estimated as 59.6 Gt C yr-1 by MOD-Sim-CYCLE, whereas it was 62.7 Gt C yr-1 in case of Sim-CYCLE. An intercomparison of LAI and NPP for world's major ecosystems was made for MOD-Sim-CYCLE and Sim-CYCLE. Differences both in magnitude and seasonality were observed in between MODIS-LAI and Sim-CYCLE simulated LAI for each biome. However, MOD-Sim-CYCLE LAI showed seasonality very accurately, synchronising with NPP and provided information on actual phenological conditions of the vegetations on the ground. A high correlation was also found between observed NPP and MOD-Sim-CYCLE NPP.

Hazarika, M.; Yasuoka, Y.; Ito, A.; Dye, D.

2003-12-01

35

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

36

Cycles  

NSDL National Science Digital Library

Just about anywhere you look in the natural sciences you'll find a cycle of some description. From cells to individuals to populations and beyond, cyclical patterns exist on every scale. The following collection of Web sites follows on this theme: The first site (1) is an excellent, animated introduction to the cell cycle from Cells Alive! Users can also get a closer look at the stages of mitosis by following the links provided. The next site from the Center for Biological Timing contains a tutorial on chronobiology, the study of biological rhythms (2). Visitors will find a thorough overview of the human clock and related concepts, with emphasis on our 24-hour sleep-wake cycle. Speaking of internal cycles, the next site contains an interesting article from BBC News, relating how a woman's choice of men may vary in accordance with her menstrual cycle (3). The next site moves from internal to externally-evident cycles, namely the life cycle of the monarch butterfly. Monarch Watch provides a detailed description of the butterfly life cycle, from egg to larva to pupa to adult (4). Perhaps not quite as appealing as the monarch butterfly, but nevertheless intriguing, Schistosoma flatworms have a complicated life cycle involving humans and a particular group of snails. The University of California-Los Angeles Institute of the Environment offers an illustrated explanation of this highly specialized life cycle (5). The following site from Science New Online describes how global climate change is accelerating the annual life cycles of plants and animals around the world (6). On the level of population, the Natural History Museum of Los Angeles County offers the familiar example of the Canada lynx and the hare -- the same example used by countless textbooks to demonstrate the cyclical nature of predator-prey dynamics (7). And finally, Georgia State University provides a nicely simplified introduction to the energy cycle in living things, focusing on the transfer of energy from the sun to plants to animals (8).

Sohmer, Rachel.

37

Combined cycle energy production: Overview of worldwide utilization and techniques  

NASA Astrophysics Data System (ADS)

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

Roche, M.

1982-06-01

38

The NASA Energy and Water cycle Study (NEWS)  

Microsoft Academic Search

With their unprecedented new observation capacity combined with revolutions in modeling capability, satellite observations have great potential to make huge advances in water and energy cycle prediction. To realize this goal, we must develop a discipline of prediction and verification through the integration of water and energy cycle observations and models, and to verify model predictions against observed phenomena to

P. Houser; J. Entin

2008-01-01

39

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

40

XPak3 promotes cell cycle withdrawal during primary neurogenesis in Xenopus laevis  

PubMed Central

We have isolated the Xenopus p21-activated kinase 3 (XPak3) by virtue of its expression in the territory of primary neurogenesis in the developing embryo. XPak3, but not the other Pak variants, responds positively to X-Ngnr-1 and negatively to X-Notch-1. A constitutively active form of XPak3, generated by fusing a myristylation signal to the N-terminus (XPak3-myr), induces early cell cycle arrest at high concentrations, while ectopic expression of low amounts induces premature neuronal differentiation. Conversely, XPak3 loss of function achieved by use of an antisense morpholino oligonucleotide increases cell proliferation and inhibits neuronal differentiation; this phenotype is rescued by co-injection of XPak3-myr. We conclude that XPak3 is a novel member of the proneural pathway, functioning downstream of neurogenin to withdraw neuronally programmed cells from the mitotic cell cycle, thus allowing for their differentiation.

Souopgui, Jacob; Solter, Marion; Pieler, Tomas

2002-01-01

41

Turbulent Mixing of Primary and Secondary Flow Streams in a Rocket-Based Combined Cycle Engine  

NASA Technical Reports Server (NTRS)

This viewgraph presentation gives an overview of the turbulent mixing of primary and secondary flow streams in a rocket-based combined cycle (RBCC) engine. A significant RBCC ejector mode database has been generated, detailing single and twin thruster configurations and global and local measurements. On-going analysis and correlation efforts include Marshall Space Flight Center computational fluid dynamics modeling and turbulent shear layer analysis. Potential follow-on activities include detailed measurements of air flow static pressure and velocity profiles, investigations into other thruster spacing configurations, performing a fundamental shear layer mixing study, and demonstrating single-shot Raman measurements.

Cramer, J. M.; Greene, M. U.; Pal, S.; Santoro, R. J.; Turner, Jim (Technical Monitor)

2002-01-01

42

Investigation of Energy Dissipation in an Ejector Refrigeration Cycle  

Microsoft Academic Search

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

Christian Tischendorf; Denise Janotte; Ricardo Fiorenzano; Wilhelm Tegethoff

2009-01-01

43

A novel cryogenic power cycle for LNG cold energy recovery  

Microsoft Academic Search

A novel cryogenic cycle by using a binary mixture as working fluids and combined with a vapor absorption process was proposed to improve the energy recovery efficiency of an LNG (liquefied natural gas) cold power generation. The cycle was simulated with seawater as the heat source and LNG as the heat sink, and the optimization of the power generated per

Yanni Liu; Kaihua Guo

2011-01-01

44

GEWEX: The Global Energy and Water Cycle Experiment  

NASA Technical Reports Server (NTRS)

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

Chahine, M.; Vane, D.

1994-01-01

45

Cycle-accurate simulation of energy consumption in embedded systems  

Microsoft Academic Search

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

Tajana Šimuni?; Luca Benini; Giovanni De Micheli

1999-01-01

46

A novel thermally biased mechanical energy conversion cycle  

NASA Astrophysics Data System (ADS)

This paper demonstrates a new power cycle for direct conversion of mechanical energy into electrical energy under a thermal bias. The cycle consisted sequentially of (i) an electric poling process under zero stress, (ii) an isoelectric process consisting of applying a uniaxial compressive stress ?H followed by (iii) an electric de-poling process under constant compressive stress, and finally (iv) an isoelectric process consisting of removing the compressive stress. The new cycle was performed at constant bias-temperature Tb. It was demonstrated on [001]-poled 0.72PbMg1/3Nb2/3O3-0.28PbTiO3 single crystals. The power density increased with increasing cycle frequency and compressive stress for frequency up to 1 Hz. Maximum energy and power densities of 44 J/l/cycle and 44 W/l were achieved at 1 Hz for bias-temperature Tb of 80 °C and electric field cycled between 0.2 and 0.8 MV/m with compressive stress ?H = 25.13 MPa. This was attributed to a tetragonal-monoclinic-orthorhombic phase transition sequence. The material efficiency reached up to 87% and exceeded that of a similar thermomechanical power cycle performed on pyroelectric material. Finally, a physical model predicting the power density was derived and yielded accurate predictions of experimental data for all bias-temperatures considered and cycle frequency up to 1 Hz.

McKinley, Ian M.; Goljahi, Sam; Lynch, Christopher S.; Pilon, Laurent

2013-12-01

47

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

48

Quantitative model of cell cycle arrest and cellular senescence in primary human fibroblasts.  

PubMed

Primary human fibroblasts in tissue culture undergo a limited number of cell divisions before entering a non-replicative "senescent" state. At early population doublings (PD), fibroblasts are proliferation-competent displaying exponential growth. During further cell passaging, an increasing number of cells become cell cycle arrested and finally senescent. This transition from proliferating to senescent cells is driven by a number of endogenous and exogenous stress factors. Here, we have developed a new quantitative model for the stepwise transition from proliferating human fibroblasts (P) via reversibly cell cycle arrested (C) to irreversibly arrested senescent cells (S). In this model, the transition from P to C and to S is driven by a stress function ? and a cellular stress response function F which describes the time-delayed cellular response to experimentally induced irradiation stress. The application of this model based on senescence marker quantification at the single-cell level allowed to discriminate between the cellular states P, C, and S and delivers the transition rates between the P, C and S states for different human fibroblast cell types. Model-derived quantification unexpectedly revealed significant differences in the stress response of different fibroblast cell lines. Evaluating marker specificity, we found that SA-?-Gal is a good quantitative marker for cellular senescence in WI-38 and BJ cells, however much less so in MRC-5 cells. Furthermore we found that WI-38 cells are more sensitive to stress than BJ and MRC-5 cells. Thus, the explicit separation of stress induction from the cellular stress response, and the differentiation between three cellular states P, C and S allows for the first time to quantitatively assess the response of primary human fibroblasts towards endogenous and exogenous stress during cellular ageing. PMID:22879912

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

2012-01-01

49

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.

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

2007-01-01

50

HPV8 early genes modulate differentiation and cell cycle of primary human adult keratinocytes  

PubMed Central

Human papillomaviruses (HPV) have been associated with the development of non-melanoma skin cancer (NMSC) but the molecular mechanisms of the role of the virus in NMSC development are not clearly understood. Abnormal epithelial differentiation seen in malignant transformation of keratinocytes is associated with changes in keratin expression. The purpose of this study was to investigate the phenotype of primary human adult keratinocytes expressing early genes of HPV8 with specific reference to their differentiation and cell cycle profile to determine whether early genes of HPV8 lead to changes that are consistent with transformation. The expression of HPV8 early genes either individually or simultaneously caused distinct changes in the keratinocyte morphology and induced an abnormal keratin expression pattern, that included simple epithelial (K8, K18, K19), hyperproliferation-specific (K6, K16), basal-specific (K14, K15) and differentiation-specific (K1, K10) keratins. Our results indicate that expression of HPV8 early genes disrupts the normal keratin expression pattern in vitro. Expression of HPV8-E7 alone caused polyploidy that was associated with decreased expression of p21 and pRb. Expression of individual genes or in combination differentially influenced cell morphology and cell cycle distribution which might be important in HPV8-induced keratinocyte transformation.

Akgul, Baki; Ghali, Lucy; Davies, Derek; Pfister, Herbert; Leigh, Irene M.; Storey, Alan

2008-01-01

51

Global constraints on net primary production and inorganic carbon supply during glacial and interglacial cycles  

NASA Astrophysics Data System (ADS)

models have good skill at reproducing glacial-interglacial transitions in climatic variables. Here we propose a simple two-box and two-state relaxation-type model for the upper ocean (surface and permanent thermocline layers) where dissolved inorganic carbon/nutrients are supplied by the deep ocean and through remineralization within the upper ocean. The model is tuned using genetic algorithms to simulate the atmospheric CO2 time series for the last four glacial-interglacial cycles. The fit to the data is very good, with correlations above 0.8, as the upper ocean responds to shifts in (1) the intensity of the meridional overturning circulation, from off to on during the glacial-interglacial transition, and (2) the size and sign of net primary production, with respiration greatly exceeding primary production during interglacial periods and production larger than respiration during the glacial phase. The glacial-interglacial transitions are interpreted as shifts between two distinct metabolic states of the Earth system, with high/low supply of dissolved inorganic carbon and nutrients to the productive upper ocean during interglacial/glacial periods.

Pelegrí, Josep L.; De La Fuente, Patricia; Olivella, Roger; García-Olivares, Antonio

2013-12-01

52

The Lorenz energy cycle in simulated rotating annulus flows  

NASA Astrophysics Data System (ADS)

Lorenz energy cycles are presented for a series of simulated differentially heated rotating annulus flows, in the axisymmetric, steady, amplitude vacillating, and structurally vacillating flow regimes. The simulation allows contributions to the energy diagnostics to be identified in parts of the fluid that cannot be measured in experiments. These energy diagnostics are compared with laboratory experiments studying amplitude vacillation, and agree well with experimental time series of kinetic and potential energy, as well as conversions between them. Two of the three major energy transfer paradigms of the Lorenz energy cycle are identified—a Hadley-cell overturning circulation, and baroclinic instability. The third, barotropic instability, was never dominant, but increased in strength as rotation rate increased. For structurally vacillating flow, which matches the Earth's thermal Rossby number well, the ratio between energy conversions associated with baroclinic and barotropic instabilities was similar to the measured ratio in the Earth's mid-latitudes.

Young, R. M. B.

2014-05-01

53

SWECS Cost of Energy Based on Life Cycle Costing.  

National Technical Information Service (NTIS)

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

W. R. Briggs

1980-01-01

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

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

Microsoft Academic Search

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

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

2005-01-01

56

Cycle of Waste Heat Energy Transformation.  

National Technical Information Service (NTIS)

There is a world-wide interest in the transformation of industrial waste heat with temperatures up to 300 exp 0 C into mechanical or electrical energy by using ORC-technique. The actual activities deal with the working fluids as well as with the plant com...

H. Bohrmann C. Eynatten R. Krause W. Rudolph G. Gneuss

1983-01-01

57

Solid absorbtion cycle solar energy: Refrigeratores  

NASA Astrophysics Data System (ADS)

There has been recent worldwide interest in the development of solar thermal powered refrigerators utilizing a solid absorber system. Three proposed absorber-working fluid combinations are examined: zeolite/water; calcium chloride/ammonia; and activated charcoal/alcohol. Experiments with the zeolite/water system are also discussed. It is concluded that the proper activation of the solid absorbent, heat transfer in the solar collector, and the circuit design have the greatest influence on the maximum energy conversion efficiency obtainable.

Anhalt, Jorgdieter; Gill, Walter

1987-02-01

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

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

NASA Astrophysics Data System (ADS)

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

Osman, Ayat E.

60

Sharp knee phenomenon of primary cosmic ray energy spectrum  

NASA Astrophysics Data System (ADS)

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

Ter-Antonyan, Samvel

2014-06-01

61

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

62

Life cycle analysis of energy systems: Methods and experience  

SciTech Connect

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

Morris, S.C.

1992-08-01

63

Life cycle analysis of energy systems: Methods and experience  

SciTech Connect

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

Morris, S.C.

1992-01-01

64

Linking the xanthophyll cycle with thermal energy dissipation  

Microsoft Academic Search

This perspective summarizes my personal recollections about the initial discovery of the involvement of the xanthophyll cycle\\u000a in photoprotective energy dissipation, starting with my arrival at Olle Björkman's laboratory at the Carnegie Institution\\u000a and focusing on events from the mid-1980s to the early 1990s.

Barbara Demmig-Adams

2003-01-01

65

Linking the xanthophyll cycle with thermal energy dissipation  

Microsoft Academic Search

This perspective summarizes my personal recollections about the initial discovery of the involvement of the xanthophyll cycle in photoprotective energy dissipation, starting with my arrival at Olle Björkman's laboratory at the Carnegie Institution and focusing on events from the mid-1980s to the early 1990s.

Barbara Demmig-Adams

2003-01-01

66

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.

67

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

68

NASA's Earth Science Enterprise's Water and Energy Cycle Focus Area  

NASA Astrophysics Data System (ADS)

Understanding the Water and Energy cycles is critical towards improving our understanding of climate change, as well as the consequences of climate change. In addition, using results from water and energy cycle research can help improve water resource management, agricultural efficiency, disaster management, and public health. To address this, NASA's Earth Science Enterprise (ESE) has an end-to-end Water and Energy Cycle Focus Area, which along with the ESE's other five focus areas will help NASA answer key Earth Science questions. In an effort to build upon the pre-existing discipline programs, which focus on precipitation, radiation sciences, and terrestrial hydrology, NASA has begun planning efforts to create an implementation plan for integrative research to improve our understanding of the water and energy cycles. The basics of this planning process and the core aspects of the implementation plan will be discussed. Roadmaps will also be used to show the future direction for the entire focus area. Included in the discussion, will be aspects of the end-to-end nature of the Focus Area that encompass current and potential actives to extend research results to operational agencies to enable improved performance of policy and management decision support systems.

Entin, J. K.

2004-05-01

69

Nitrogen cycling in an integrated biomass for energy system  

Microsoft Academic Search

A series of experiments was conducted to evaluate N cycling in three components of an integrated biomass for energy system, i.e. water hyacinth production, anaerobic digestion in hyacinth biomass, and recycling of digester effluent and sludge. Plants assimilated 50 to 90% of added N in hyacinth production systems. Up to 28% of the total plant N was contained in hyacinth

1986-01-01

70

Analysis of cooling cycles with clathrate energy storage  

Microsoft Academic Search

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

Gadalla

1988-01-01

71

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

72

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

73

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

PubMed

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

Kim, Hyung Chul; Wallington, Timothy J

2013-06-18

74

Energy gains of a wall-confined fusion cycle  

SciTech Connect

Calculations of energy gain are made for a wall-confined deuterium--tritium fusion cycle. Plasma, first heated by strong shock waves, re-expands to completely fill a cylindrical cavity. An azimuthal magnetic field, everywhere parallel to the walls, provides thermal insulation. The energy input is evaluated by solving the transverse magnetohydrodynamic shock wave equations. The fusion energy yield is determined by the competition between fusion burn, radiation, and wall cooling. A one-dimensional initial value code is used to evaluate the plasma energy loss rates and the fusion burn. Two-dimensional loss mechanisms are estimated using a modified form of the one-dimensional model. Energy gain ratios of twenty are calculated for a cylinder whose characteristic size L is less than one meter. Energy breakeven is found for Lapprox.0.2 m, with an energy input of 1.9 MJ at a power of 8.8 TW.

Kmetyk, L.N.; Gross, R.A.

1982-06-01

75

Low Cost Solar Energy Conversion (Carbon Cycle 2.0)  

ScienceCinema

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

Ramesh, Ramamoorthy

2011-06-08

76

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

77

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

PubMed

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

Khanna, Vikas; Bakshi, Bhavik R

2009-03-15

78

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.

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

2014-01-01

79

Development of a Heat Pump Aggregate for Saving Primary Energy.  

National Technical Information Service (NTIS)

Development of a new kind of heat pump or cooling aggregate, using primary energy in the form of pressureless combustion at the place of installation. This ensures minimum pollution, noise, and wear. The operating principle of the Vuilleumier heat pump ha...

C. Schneider H. P. Doetsch

1985-01-01

80

The Primary Energy Release in Reconnection Flare Models.  

National Technical Information Service (NTIS)

A brief review is given on the primary energy release associated with reconnection flare models. In particular will be examined how the most recent flare models of Spicer and Uchida and Sakurai have attempted to overcome the standard difficulties with rec...

D. S. Spicer

1978-01-01

81

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

82

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

83

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

84

Energy Conversion Advanced Heat Transport Loop and Power Cycle  

SciTech Connect

The Department of Energy and the Idaho National Laboratory are developing a Next Generation Nuclear Plant (NGNP) to serve as a demonstration of state-of-the-art nuclear technology. The purpose of the demonstration is two fold 1) efficient low cost energy generation and 2) hydrogen production. Although a next generation plant could be developed as a single-purpose facility, early designs are expected to be dual-purpose. While hydrogen production and advanced energy cycles are still in its early stages of development, research towards coupling a high temperature reactor, electrical generation and hydrogen production is under way. Many aspects of the NGNP must be researched and developed in order to make recommendations on the final design of the plant. Parameters such as working conditions, cycle components, working fluids, and power conversion unit configurations must be understood. Three configurations of the power conversion unit were demonstrated in this study. A three-shaft design with 3 turbines and 4 compressors, a combined cycle with a Brayton top cycle and a Rankine bottoming cycle, and a reheated cycle with 3 stages of reheat were investigated. An intermediate heat transport loop for transporting process heat to a High Temperature Steam Electrolysis (HTSE) hydrogen production plant was used. Helium, CO2, and an 80% nitrogen, 20% helium mixture (by weight) were studied to determine the best working fluid in terms cycle efficiency and development cost. In each of these configurations the relative component size were estimated for the different working fluids. The relative size of the turbomachinery was measured by comparing the power input/output of the component. For heat exchangers the volume was computed and compared. Parametric studies away from the baseline values of the three-shaft and combined cycles were performed to determine the effect of varying conditions in the cycle. This gives some insight into the sensitivity of these cycles to various operating conditions as well as trade offs between efficiency and capital cost. Prametric studies were carried out on reactor outlet temperature, mass flow, pressure, and turbine cooling. Recommendations on the optimal working fluid for each configuration were made. A steady state model comparison was made with a Closed Brayton Cycle (CBC) power conversion system developed at Sandia National Laboratory (SNL). A preliminary model of the CBC was developed in HYSYS for comparison. Temperature and pressure ratio curves for the Capstone turbine and compressor developed at SNL were implemented into the HYSYS model. A comparison between the HYSYS model and SNL loop demonstrated power output predicted by HYSYS was much larger than that in the experiment. This was due to a lack of a model for the electrical alternator which was used to measure the power from the SNL loop. Further comparisons of the HYSYS model and the CBC data are recommended. Engineering analyses were performed for several configurations of the intermediate heat transport loop that transfers heat from the nuclear reactor to the hydrogen production plant. The analyses evaluated parallel and concentric piping arrangements and two different working fluids, including helium and a liquid salt. The thermal-hydraulic analyses determined the size and insulation requirements for the hot and cold leg pipes in the different configurations. Economic analyses were performed to estimate the cost of the va

Oh, C. H.

2006-08-01

85

ECUT energy data reference series: Otto cycle engines in transportation  

SciTech Connect

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

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

1984-07-01

86

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

NASA Technical Reports Server (NTRS)

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

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

1976-01-01

87

Neutron energy spectrum effects in primary damage formation  

SciTech Connect

Designers of the National Spallation Neutron Source (NSNS) must make extensive use of radiation effects data obtained from fission reactor irradiations. One uncertainty in using the fission reactor database is the impact of the much higher energy neutrons (up to 1000 MeV) that will be produced in the NSNS, whereas a typical fission reactor spectrum has few neutrons above 2 to 5 MeV. The spallation neutrons will in turn lead to the formation of atomic displacement cascades by higher-energy primary knockon atoms (PKA). Thus, it is important to determine the degree to which differences in PKA energy spectra may influence a materials response to irradiation. This issue has been addressed through the use of displacement cascade simulations using molecular dynamics (MD). The results presented here include energies as high as 50 keV, corresponding to the average cascade energy from a 2.3-MeV neutron.

Stoller, R.E. [Oak Ridge National Lab., TN (United States); Greenwood, L.R. [Pacific Northwest National Lab., Richland, WA (United States)

1999-09-01

88

Solar power satellite life-cycle energy recovery consideration  

SciTech Connect

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

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

1994-12-31

89

Solar power satellite—Life-cycle energy recovery considerations  

NASA Astrophysics Data System (ADS)

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 concentrates on life-cycle energy recovery instead of monetary aspects. The trade-offs between various power generation systems (different types of solar cells, solar dynamic), various construction and installation strategies (using terrestrial or extra-terrestrial resources) and the expected/required lifetime of the SPS are reviewed. The presented work is based on a 2-year study performed at the Technical University of Munich. The study showed that the main energy which is needed to make a solar power satellite a reality is required for the production of the solar power plant components (up to 65%), especially for the solar cell production. Whereas transport into orbit accounts in the order of 20% and the receiving station on Earth (rectenna) requires in the order of 15% of the total energy investment. The energetic amortization time, i.e. the time the SPS has to be operational to give back the amount of energy which was needed for its production, installation and operation, is in the order of two years.

Weingartner, S.; Blumenberg, J.

1995-05-01

90

Solar power satellite life-cycle energy recovery consideration  

NASA Astrophysics Data System (ADS)

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

Weingartner, S.; Blumenberg, J.

91

Atmospheric energy cycle: a regional indicator of the climate vulnerability  

NASA Astrophysics Data System (ADS)

The assessment of the vulnerability of densely populated regions to major natural disasters, including climatic variations, is a topic of intense investigation. Indices of vulnerability have been developed based on social, economic and climatic factors. However, the relative importance of the processes involved is still subject of debate. Here, we investigate the possibility to employ the Lorentz energy cycle as an indicator of the climatic conditions. We compute the energy and energy conversion for a period of 30 years for regions that are already defined as vulnerable to climate variations. The atmospheric energetics of São Paulo is calculated climatically and highlighted the periods occurrence of floods. From detailed studies of energy during periods posted some regional indicators of the climate vulnerabilities are suggested for cities studied, showing the importance of atmospheric dynamics in defining these indicators. This work is supported by FAPESP under the grant agreement no. 2008/58161-1 (PFPMCG - Projeto Temático) and no. 2011/13976-0.

Da Silva, L. A.; Marengo, J. A.; Vieira, L. A.; Chan, C. S.; Lyra, A.

2013-05-01

92

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

93

High energy primary electron spectrum observed by the emulsion chamber  

NASA Technical Reports Server (NTRS)

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

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

1978-01-01

94

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

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

95

Recovered Energy Generation Using an Organic Rankine Cycle System  

SciTech Connect

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

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

2009-01-01

96

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

SciTech Connect

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

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

2008-07-15

97

Fuel cycle analysis for fossil energy systems: coal combustion  

SciTech Connect

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

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

1981-02-01

98

High-Energy Sub-Cycle Waveform Synthesis and Characterization  

NASA Astrophysics Data System (ADS)

The control of atomic scale electronic motion by ultrafast optical electric field waveforms strong enough to mitigate the atomic Coulomb potential has broken tremendous new ground with the advent of phase controlled high-energy few-cycle pulse sources. Currently, such sources are based on Ti:sapphire amplifiers and hollow-core fiber post-compression or optical parametric chirped pulse amplification, together with optical gating techniques. Significant control of the waveform on sub-cycle time scales, however, requires a fully phase-controlled multiple-octave-spanning spectrum. Here, we present a first fully phase-controlled multi-octave-spanning source that supports gigawatt-peak-power isolated single-cycle waveforms based on pulse synthesis of two carrier-envelope phase (CEP) stable OPCPA systems. It is especially a challenge to fully characterize such ultrawide band waveforms. We apply two-dimensional spectral shearing interferometry (2DSI), which can measure the group delay between all spectral components of the synthesized pulse.

Kärtner, Franz

2011-03-01

99

Cataplerotic TCA cycle flux determined as glutamate-sustained oxygen consumption in primary cultures of astrocytes  

Microsoft Academic Search

Utilization of glucose by adult brain as its metabolic substrate does not mean that glutamate cannot be synthesized from glucose and subsequently oxidatively degraded. Between 10 and 20% of total pyruvate metabolism in brain occurs as formation of oxaloacetate (OAA), a tricarboxylic acid (TCA) cycle intermediate, from pyruvate plus CO2. This anaplerotic (‘pool-filling’) process occurs in astrocytes, which in contrast

Leif Hertz; Elna Hertz

2003-01-01

100

On the primaries and the generic energy distribution of Blazars On the primaries and the generic energy distribution of Blazars  

NASA Astrophysics Data System (ADS)

The acceleration of charged particles in astrophysical shock waves and their consequent emission, is critical on testing the astroparticle physical limits occurring in environments such as Blazars. In the present work we discuss how the variation of the energy spectral index of the primary accelerated electrons, which occur in mild and (extreme) relativistic shocks of Blazars, affect the limits of the extragalactic absorption models. While the electron spectrum is (was) traditionally assumed to follow an E^{-2} spectrum below the cooling break energy, recent models of diffusive acceleration result in energy spectra with varying spectral indexes such as E^{-1.0} up to E^{-2.5} which pose critical physical constraints on astroparticle processes. Our simulation results show that, in the relativistic regime, not only the given shock boost factor and inclination of the magnetic field to the shock normal affect the spectral form and spectral index of the primary particles, but also, and most importantly, the type of the scattering off hydromagnetic turbulence of the deflected particle momenta, plays a crucial role for the spectral characteristics of the primary particles. Thus, under given circumstances of a combination of high shock Lorentz factors, shock inclinations and specific type of scattering, the primary electron spectra could get as flat as s ? 1.0. Based on the latter, one sees that assuming a photon index of 1.0 instead of 1.5 (considering a Thomson or Klein-Nishina condit ion) it relaxes the EBL limit by about a factor of 1.3.

Meli, Athina; Kneiske, Tanja; Becker, Julia

101

Modeling the Q-cycle mechanism of transmembrane energy conversion  

NASA Astrophysics Data System (ADS)

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 us 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.

Smirnov, Anatoly Yu; Nori, Franco

2012-02-01

102

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

Microsoft Academic Search

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)

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

2011-01-01

103

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

PubMed Central

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 NMR and GC-MS. These include metabolites that report on the activity of glycolysis, Krebs' cycle, pentose phosphate pathway and pyrimidine biosynthesis. Results The Rh30 cells proliferated faster than the myocytes. Major differences in flux through glycolysis were evident from incorporation of label into secreted lactate, which accounts for a substantial fraction of the glucose carbon utilized by the cells. Krebs' cycle activity as determined by 13C isotopomer distributions in glutamate, aspartate, malate and pyrimidine rings was considerably higher in the cancer cells than in the primary myocytes. Large differences were also evident in de novo biosynthesis of riboses in the free nucleotide pools, as well as entry of glucose carbon into the pyrimidine rings in the free nucleotide pool. Specific labeling patterns in these metabolites show the increased importance of anaplerotic reactions in the cancer cells to maintain the high demand for anabolic and energy metabolism compared with the slower growing primary myocytes. Serum-stimulated Rh30 cells showed higher degrees of labeling than serum starved cells, but they retained their characteristic anabolic metabolism profile. The myocytes showed evidence of de novo synthesis of glycogen, which was absent in the Rh30 cells. Conclusion The specific 13C isotopomer patterns showed that the major difference between the transformed and the primary cells is the shift from energy and maintenance metabolism in the myocytes toward increased energy and anabolic metabolism for proliferation in the Rh30 cells. The data further show that the mitochondria remain functional in Krebs' cycle activity and respiratory electron transfer that enables continued accelerated glycolysis. This may be a common adaptive strategy in cancer cells.

Fan, Teresa WM; Kucia, Magda; Jankowski, Kacper; Higashi, Richard M; Ratajczak, Janina; Ratajczak, Marius Z; Lane, Andrew N

2008-01-01

104

An advanced zero emission power cycle with integrated low temperature thermal energy  

Microsoft Academic Search

An innovative zero emission hybrid cycle named HICES (hybrid and improved CES cycle) is presented in this paper. It can utilize fossil fuel and low quality thermal energy such as waste heat from industrial processes and solar thermal energy for highly efficient electric power generation. In the HICES cycle, natural gas is internally combusted with pure oxygen. External low quality

Chenhua Gou; Ruixian Cai; Guoqiang Zhang

2006-01-01

105

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

106

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

Microsoft Academic Search

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

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

1996-01-01

107

Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization  

Microsoft Academic Search

In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits

Roger Sathre; Leif Gustavsson; Johan Bergh

2010-01-01

108

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

National Technical Information Service (NTIS)

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

S. A. Shankle

1994-01-01

109

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

SciTech Connect

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

Yang, Xi; /Fermilab

2004-11-01

110

GEWEX: The Global Energy and Water Cycle Experiment  

NASA Astrophysics Data System (ADS)

The need for better quantitative understanding of energy fluxes and water exchanges is basic to all climate studies, yet our quantitative knowledge of the global hydrological cycle remains surprisingly poor. Evaporation minus precipitation or, similarly, the net flow of water from land to oceans and the net advection of moisture from the marine atmosphere to the terrestrial atmosphere is known at best to a factor of two to three (J. Schaake, personal communication, 1991). The regional and temporal distribution of the components of the hydrological budget are even more uncertain.Improved understanding of the global hydrological cycle has been limited in part by the absence of reliable global data on such essential quantities as precipitation, evaporation, and atmospheric transport; acquisition of these data is a prerequisite for the study of global energetics and hydrology. Space agencies in the United States, Europe, and Japan have announced plans to launch a series of global Earth observing satellites in the late 1990s to monitor these essential atmospheric and surface parameters and to complement existing operational meteorological and hydrological networks.

Chahine, Moustafa T.

111

Altered cytokine gene expression in peripheral blood monocytes across the menstrual cycle in primary dysmenorrhea: a case-control study.  

PubMed

Primary dysmenorrhea is one of the most common gynecological complaints in young women, but potential peripheral immunologic features underlying this condition remain undefined. In this paper, we compared 84 common cytokine gene expression profiles of peripheral blood mononuclear cells (PBMCs) from six primary dysmenorrheic young women and three unaffected controls on the seventh day before (secretory phase), and the first (menstrual phase) and the fifth (regenerative phase) days of menstruation, using a real-time PCR array assay combined with pattern recognition and gene function annotation methods. Comparisons between dysmenorrhea and normal control groups identified 11 (nine increased and two decreased), 14 (five increased and nine decreased), and 15 (seven increased and eight decreased) genes with ? 2-fold difference in expression (P<0.05) in the three phases of menstruation, respectively. In the menstrual phase, genes encoding pro-inflammatory cytokines (IL1B, TNF, IL6, and IL8) were up-regulated, and genes encoding TGF-? superfamily members (BMP4, BMP6, GDF5, GDF11, LEFTY2, NODAL, and MSTN) were down-regulated. Functional annotation revealed an excessive inflammatory response and insufficient TGF-? superfamily member signals with anti-inflammatory consequences, which may directly contribute to menstrual pain. In the secretory and regenerative phases, increased expression of pro-inflammatory cytokines and decreased expression of growth factors were also observed. These factors may be involved in the regulation of decidualization, endometrium breakdown and repair, and indirectly exacerbate primary dysmenorrhea. This first study of cytokine gene expression profiles in PBMCs from young primary dysmenorrheic women demonstrates a shift in the balance between expression patterns of pro-inflammatory cytokines and TGF-? superfamily members across the whole menstrual cycle, underlying the peripheral immunologic features of primary dysmenorrhea. PMID:23390521

Ma, Hongyue; Hong, Min; Duan, Jinao; Liu, Pei; Fan, Xinsheng; Shang, Erxin; Su, Shulan; Guo, Jianming; Qian, Dawei; Tang, Yuping

2013-01-01

112

Waste recycling primary source of energy in deep ocean  

NASA Astrophysics Data System (ADS)

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

Schultz, Colin

2012-02-01

113

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

114

Water and Energy Cycle EOS House web portal (WECHO)  

NASA Astrophysics Data System (ADS)

Water is the origin of life, the vast amount of water related Earth observation is of great value to water community users. This paper reports our research and development in providing the Water and Energy Cycle EOS House web portal (WECHO), a web-based tool, for the community to access water resource archived in EOS ClearingHouse (ECHO). WECHO aims to provide users the capabilities to search, browse and visualize data through common browsers, such as Internet Explore and Firefox. WECHO supports users to 1) access all ECHO functionalities, including registering as a new user, querying metadata and ordering delivery of earth observing data, subscribing to updates of interested metadata items and specific events; 2) semantically search ECHO with water ontologies integrated; 3) interactively access Earth Information Exchange (EIE) with the support of Semantic Web for Earth and Environmental Terminology (SWEET) and NOESIS.

Li, Z.; Huang, Q.; Li, W.; Zhu, H.; Yang, C.; Houser, P.; Larko, M.

2008-12-01

115

Analysis of cooling cycles with clathrate energy storage  

SciTech Connect

A prototype is presented of a thermal energy storage facility, with an appropriate storage medium, that can be applicable in environmental control of residential and commercial buildings. A simulated heat pump cooling system which utilizes a refrigerant gas hydrate as a storage medium was experimentally and theoretically analyzed. Numerous closed loop cycles using a clathrate in direct contact heat transfer with the refrigerant were evaluated to verify the system operation and to evaluate the system components. The basic background of the direct contact heat transfer method in which heat transfer enhancement is achieved is investigated. The aim is to provide clear theoretical insights to the phase change of the storage medium (clathrate), and present a mathematical model that is compatible with the latent heat release rate. A finite difference computer code utilizing the apparent heat capacity model was developed to predict the experimental temperature fields inside an insulated cylindrical horizontal thermal energy storage tank as time progresses. The experimental and theoretical results show that clathrate energy storage and direct contact heat transfer are technically feasible.

Gadalla, M.A.

1988-01-01

116

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

117

Open cycle ocean thermal energy conversion system structure  

DOEpatents

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

Wittig, J. Michael (West Goshen, PA)

1980-01-01

118

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

NASA Astrophysics Data System (ADS)

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

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

2008-05-01

119

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

120

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

121

Energy Conversion Alternatives Study (ECAS), Westinghouse Phase 1. Volume 5: Combined Gas-Steam Turbine Cycles.  

National Technical Information Service (NTIS)

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 c...

D. J. Amos R. W. Foster-pegg R. M. Lee

1976-01-01

122

A benchmark for life cycle air emissions and life cycle impact assessment of hydrokinetic energy extraction using life cycle assessment  

Microsoft Academic Search

As the demand for renewable energy increases, it becomes important to critically examine the environmental impacts of renewable energy production. Often, the approach has been trial and error in renewable energy with respect to its impact on the environment. Hydrokinetic Energy Extraction (HEE) has been seen as a potentially “benign” form of renewable hydropower. This paper provides a benchmark for

Veronica B. Miller; Amy E. Landis; Laura A. Schaefer

2011-01-01

123

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

SciTech Connect

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

LaClair, Tim J [ORNL] [ORNL

2011-05-01

124

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

125

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

Microsoft Academic Search

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

Seppo Junnila

2008-01-01

126

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

127

Decreased levels of the cell-cycle inhibitor p27Kip1 protein: prognostic implications in primary breast cancer.  

PubMed

Breast cancer is the second leading cause of cancer death in North American women. There is considerable need for reliable prognostic markers to assist clinicians in making management decisions. Although a variety of factors have been tested, only tumor stage, grade, size, hormone receptor status, and S-phase fraction are used on a routine basis. The cell cycle is governed by a family of cyclin-dependent kinases (cdks), which are regulated by associated cyclins and by phosphorylation. p27Kip1, a cyclin-dependent kinase inhibitor, regulates progression from G1 into S phase by binding and inhibiting cyclin/cdks. p27Kip1 protein levels and/or activity are upregulated by growth inhibitory cytokines including transforming growth factor-beta (TGF-beta) and, thus, provide an important link between extracellular regulators and the cell cycle. Loss of p27Kip1, a negative cell-cycle regulator, may contribute to oncogenesis and tumor progression. However, p27Kip1 mutations in human tumors are extremely rare. We have demonstrated by immunohistochemistry that p27Kip1 protein levels are reduced in primary breast cancers and that this is associated with tumor progression in both in situ and invasive lesions. This was confirmed by western analysis, reflected in increased G1/S-phase cyclin-dependent kinase activities and shown to be regulated posttranscriptionally by in situ hybridization. Furthermore, on multivariate analysis, low p27Kip1 is a predictor of reduced disease-free survival. This simple and reliable immunohistochemical assay may become a routine part of breast cancer evaluation and may influence patient management. PMID:9018244

Catzavelos, C; Bhattacharya, N; Ung, Y C; Wilson, J A; Roncari, L; Sandhu, C; Shaw, P; Yeger, H; Morava-Protzner, I; Kapusta, L; Franssen, E; Pritchard, K I; Slingerland, J M

1997-02-01

128

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

PubMed

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

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

2012-10-29

129

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

PubMed Central

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

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

2010-01-01

130

Nitrogen cycling in an integrated biomass for energy system  

SciTech Connect

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

Moorhead, K.K.

1986-01-01

131

Food and life cycle energy inputs: consequences of diet and ways to increase efficiency  

Microsoft Academic Search

Food consumption is one of the most polluting everyday activities when impacts during product life cycles are considered. Greenhouse gas emissions from the food sector are substantial and need to be lowered to stabilise climate change. Here, we present an inventory of life cycle energy inputs for 150 food items available in Sweden and discuss how energy efficient meals and

Annika Carlsson-Kanyama; Marianne Pipping Ekström; Helena Shanahan

2003-01-01

132

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

EPA Science Inventory

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

133

Thorium fuel cycle of a thorium-basedadvanced nuclear energy system  

Microsoft Academic Search

This paper presents a thorium fuel cycle scheme for the thorium-based advancednuclear energy system JANES). TANES that will use thorium resources is a homemade nuclear energy system that is fit for the situation of China and some other thorium-rich regions. By the reactor physics and fuel cycle analysis, the paper gets the conclusion that if TANES decreases lattice pitch (channel

Sollychin Rayman; Ruan Yangqiang; Y SONGBO; J BAOSHAN; S SHIFEI; S GONG

2004-01-01

134

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

Microsoft Academic Search

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

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

1980-01-01

135

Sustainability Indicators for Open-Cycle Thorium-Fuelled Nuclear Energy  

Microsoft Academic Search

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

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

2012-01-01

136

Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 2: Advanced Energy Conversion Systems. Part 1: Open-Cycle Gas Turbines.  

National Technical Information Service (NTIS)

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

D. H. Brown J. C. Corman

1976-01-01

137

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

138

Ultra high energy events in ECHOS series and primary energy spectrum  

NASA Astrophysics Data System (ADS)

The compilation of ultra high energy jets suggests at present the existence of a bump in primary energy spectrum (with the standard concept of high energy collisions). The pseudo-rapidity distribution exhibits some typical anomalies, more than the (Pt) behavior, which are (may be) the fingerprints of quark gluon plasma transition. The next results of Emulsion Chamber on Supersonic (ECHOS) will be in both cases determinant to confirm those tendancies, as well as an important effort of the cosmic ray community to develop in that sense a flying emulsion chamber experiment.

Capdevielle, J. N.; Iwai, J.; Ogata, T.

1985-08-01

139

A fuel cycle assessment guide for utility and state energy planners  

SciTech Connect

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

Not Available

1994-07-01

140

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

141

Energy Balance Calculations and Assessment of Two Thermochemical Sulfur Cycles.  

National Technical Information Service (NTIS)

Thermochemical cyclic processes which include the highly endothermal decomposition of sulphuric acid are promising for hydrogen production by water-splitting. Our study is directed toward two cycles of this family, each involving the formation and decompo...

D. Leger P. Lessart J. P. Manaud R. Benizri P. Courvoisier

1978-01-01

142

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

Microsoft Academic Search

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

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

2004-01-01

143

Nuclear-fuel-cycle education: Module 11. Part I. Nuclear fuel cycle economics. Part II. Net energy model of nuclear power. Final report  

Microsoft Academic Search

This educational module covers nuclear-fuel-cycle economics and net energy analysis of nuclear power systems. The econonmics portion covers engineering economic principles and engineering economic analysis of capitalized projects. The net energy analysis covers the general concept, input-output modeling principles, energy language and model structure, environmental energy costs, the net energy analysis model, the nuclear fuel cycle, and the application of

R. Brehm; R. S. Reynolds

1981-01-01

144

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

Microsoft Academic Search

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

Heetae Kim; Tae Kyu Ahn

145

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

PubMed

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

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

2011-01-01

146

The energy spectrum of Forbush decreases during the growth phase of solar cycle 24  

NASA Astrophysics Data System (ADS)

The Forbush decrease energy spectrum, observed during the growth phase of cycle 24 in 2010-2012, was studied based on the measurements performed with the Kuzmin cosmic ray spectrograph. The data of the 24-NM-64 neutron monitor and muon telescopes, installed at water equivalent levels of 0, 7, 20, and 40 m, was used. The performed analysis indicated that a softer energy spectrum was observed during the growth phase of cycle 24 than during the previous cycle (cycle 23). The conclusion was been drawn that a more turbulent magnetic field with the predominant diffusion mechanism in the formation of the Forbush decreases in the cosmic ray intensity exists in the current cycle (cycle 24).

Grigoryev, V. G.; Starodubtsev, S. A.; Isakov, D. D.

2014-05-01

147

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

148

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

NASA Technical Reports Server (NTRS)

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

Lapenta, William M.

2008-01-01

149

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

PubMed

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

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

2011-03-01

150

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

Microsoft Academic Search

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

Jeremy Hackney; Richard de Neufville

2001-01-01

151

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

SciTech Connect

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

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

1980-12-01

152

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

SciTech Connect

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

Gorensek, M.; Edwards, T.

2009-06-11

153

Generation of Energy Optimal Complete Gait Cycles for Biped Robots  

Microsoft Academic Search

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

L. Roussel; Carlos Canudas De Wit; Ambarish Goswami

1998-01-01

154

Open cycle ocean thermal energy conversion system structure  

Microsoft Academic Search

A generally mushroom-shaped, open cycle OTEC system and distilled water producer which has a skirt-conduit structure extending from the enlarged portion of the mushroom to the ocean. The enlarged part of the mushroom houses a toroidal casing flash evaporator which produces steam which expands through a vertical rotor turbine, partially situated in the center of the blossom portion and partially

Wittig; J. Michael

1980-01-01

155

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

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

156

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

Microsoft Academic Search

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

Cristian Dinca; Patrick Rousseaux; Adrian Badea

2007-01-01

157

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

158

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

National Technical Information Service (NTIS)

Key components of open-cycle ocean thermal energy conversion systems--the flash evaporator, mist eliminator, passive predeaerator, two surface condenser stages, and two direct-contact condenser stages--have been tested using seawater. These components ope...

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

1994-01-01

159

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

SciTech Connect

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

Not Available

2010-11-01

160

Effect of Lighting System Components on Lighting Quality, Energy Use, and Life-Cycle Cost.  

National Technical Information Service (NTIS)

A computational method was developed to examine the effect of lamp, ballast, and fixture selection on the quality and quantity of illumination, energy consumption, and life-cycle cost of lighting systems. Applying this analysis to lighting layouts using d...

F. Rubinstein T. Clark M. Siminovitch R. Verderber

1986-01-01

161

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

NASA Technical Reports Server (NTRS)

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

Vane, Deborah

1993-01-01

162

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

Microsoft Academic Search

Increasingly many wireless sensor network deployments are using harvested environmental energy to extend system lifetime. Because the temporal profiles of such energy sources exhibit great variability due to dynamic weather patterns, an important problem is de- signing an adaptive duty-cycling mechanism that allows sensor nodes to maintain their power supply at sufficient levels (energy neutral operation) by adapting to changing

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

2007-01-01

163

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

164

Refrigerant114 Rankine cycle energy recovery technology from the gaseous diffusion industry  

Microsoft Academic Search

An unclassified accounting of energy recovery technology developed in the gaseous diffusion (uranium enrichment) industry during the past twenty years is presented. This spin-off knowledge may be of value to those in industry seeking to reduce operating costs while meeting the national objective of conserving energy. Four Rankine cycle energy recovery installations using Refrigerant-114 (R-114) as the working fluid are

C. O. Langerbbrake

1978-01-01

165

Energy performances and life cycle assessment of an Italian wind farm  

Microsoft Academic Search

Renewable energy sources are often presented as “clean”. A more correct definition is that they are “cleaner” than ones based on fossil fuel conversion. When the energy consumption and the environmental impacts related to the plant's life-cycle are considered, a more comprehensive assessment of these technologies can be carried out. This paper aims to evaluate the energy and the environmental

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

2008-01-01

166

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

Microsoft Academic Search

The interests in using carbon dioxide as working fluid increase since the Montreal and Kyoto Protocols were made. In this paper, a complete effort was made to study the performance of CO2 Rankine cycle powered by solar energy experimentally. The system utilizes evacuated solar collectors to convert CO2 into high-temperature supercritical state, used to produce electrical energy and thermal energy,

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

2006-01-01

167

Biomass to hydrogen for the realization of closed cycles of energy resources  

Microsoft Academic Search

The crucial mission of energy research is the promotion and implementation of methods, technologies and processes for a sustainable economic and social development. Within this framework the key progress energy systems is the realization of Closed Cycles of Energy Resources—CCER, whose goal is to achieve zero consumption in terms of non-renewable resources and no impact on the environment. A CCER

Fabio Orecchini; Enrico Bocci

2007-01-01

168

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

169

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

170

Characterization of the Interaction between Human Respiratory Syncytial Virus and the Cell Cycle in Continuous Cell Culture and Primary Human Airway Epithelial Cells?  

PubMed Central

Viruses can modify conditions inside cells to make them more favorable for replication and progeny virus production. One way of doing this is through manipulation of the cell cycle, a process that describes the ordered growth and division of cells. Analysis of model cell lines, such as A549 cells and primary airway epithelial cells, infected with human respiratory syncytial virus (HRSV) has shown alteration of the cell cycle during infection, although the signaling events were not clearly understood. In this study, targeted transcriptomic analysis of HRSV-infected primary airway epithelial cells revealed alterations in the abundances of many mRNAs encoding cell cycle-regulatory molecules, including decreases in the D-type cyclins and corresponding cyclin-dependent kinases (CDK4 and CDK6 [CDK4/6]). These alterations were reflected in changes in protein abundance and/or relocalization in HRSV-infected cells; taken together, they were predicted to result in G0/G1 phase arrest. In contrast, there was no change in the abundances of D-type cyclins in A549 cells infected with HRSV. However, the abundance of the G1/S phase progression inhibitor p21WAF1/CIP1 was increased over that in mock-treated cells, and this, again, was predicted to result in G0/G1 phase arrest. The G0/G1 phase arrest in both HRSV-infected primary cells and A549 cells was confirmed using dual-label flow cytometry that accurately measured the different stages of the cell cycle. Comparison of progeny virus production in primary and A549 cells enriched in G0/G1 using a specific CDK4/6 kinase inhibitor with asynchronously replicating cells indicated that this phase of the cell cycle was more efficient for virus production.

Wu, Weining; Munday, Diane C.; Howell, Gareth; Platt, Gareth; Barr, John N.; Hiscox, Julian A.

2011-01-01

171

Alternate cycles applied to ocean thermal energy conversion  

Microsoft Academic Search

Four open cycle OTEC concepts are described. These are: (1) single, vertical-axis turbine; (2) multiple, horizontal-axis turbine; (3) foam lift\\/hydraulic turbine; and (4) mist lift\\/hydraulic turbine. A preliminary assessment of achievable performance is made in addition to a description of the subsystem performance objectives which would support the achievement of the full potential inherent in these concepts. The results and

B. Shelpuk; A. Lewandowski

1979-01-01

172

The industrial life cycle of wind energy electrical power generation  

Microsoft Academic Search

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

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

2009-01-01

173

Life cycle inventory study of the electrical energy production in Romania  

Microsoft Academic Search

Aim, Scope and Background  The paper proposes the assessment of the environmental interventions resulting from the electrical energy production in Romania,\\u000a a Central East European country, using the LCA technique limited to a Life Cycle Inventory study (an LCA without the Life\\u000a Cycle Impact Assessment phase).\\u000a \\u000a \\u000a \\u000a Main Features  The following life cycles of the energy carriers employed in the production of the

Nicolae Peiu

2007-01-01

174

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

PubMed

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

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

2014-06-01

175

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

NASA Technical Reports Server (NTRS)

Two parallel sets of analyses, which in one case included and in the other omitted data observed by satellite based and other FGGE special observing systems are examined. The results of our previous work is extended in two separate, but not unrelated, ways. First, from these two parallel analyses, which are labeled FGGE (full FGGE system) and NOSAT (satellite omitted), it was discovered that the two sets of fields were quite close over much of the globe. Locally the influence of satellite based systems led to some differences, particularly over the Southern Hemisphere Oceans. The diabatic heating fields generated by the GLA FGGE analysis was also examined. From these fields, one can ascertain the role of total diabatic heating and of the various diabatic heating components in the atmospheric energy cycle, in particular in the generation of available potential energy.

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

1985-01-01

176

The Energy Spectrum and the Chemical Composition of Primary Cosmic Rays with Energies from 1014 to 1016 eV  

NASA Astrophysics Data System (ADS)

We have measured extensive air showers(EASs) with primary energies above 6 TeV at Mt. Chacaltaya in Bolivia since March 2000 with an air shower array called the Minimum Air Shower(MAS) array. With an equi-intensity method analysis, we obtained longitudinal development curves of EAS around and deep er than their maximum developments to be compared with simulations, in which the primary chemical composition is assumed to be a mixture of protons and irons. We determined the mixing ratio of protons as a function of the primary energy, and we derived the primary energy spectrum from 1014 to 5 × 1016 eV. We found that the average mass number of primary cosmic rays increase with energy above 1014.5 eV and the dominant component around the knee is not protons.

Ogio, S.; Kakimoto, F.; Kurashina, Y.; Tsunesada, Y.; Shirasaki, Y.; Burgoa, O.; Gotoh, E.; Harada, D.; Kadota, K.; Kaneko, T.; Matsubara, Y.; Miranda, P.; Mizumoto, Y.; Morizawa, A.; Murakami, K.; Nakatani, H.; Nishi, K.; Shimoda, S.; Tajima, N.; Teshima, M.; Tokuno, H.; Toyoda, Y.; Velarde, A.; Yamada, Y.; Yoshii, H.

2003-07-01

177

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

PubMed Central

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

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

2006-01-01

178

Energy life-cycle analysis modeling and decision support tool  

Microsoft Academic Search

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

M. Hoza; M. E. White

1993-01-01

179

Earth's Energy Budget: Seasonal Cycles in Net Radiative Flux  

NSDL National Science Digital Library

Students examine CERES radiation data to understand how the Earth's tilt causes seasonal differences in incoming solar energy, and to explore how clouds, deserts and ice modulate the reflection of energy from the Sun. The investigation is conducted using the My NASA Data Live Access Server. This resource is part of the poster, Earth's Energy Budget, which describes the role of incoming solar radiation and the gases in the atmosphere and clouds in maintaining the Earth's temperature. The role of atmospheric becomes CO² in climate change and the environments of nearby planets are compared. along with career profiles of energy budget "detectives." A student crossword and matching game test vocabulary understanding.

180

GEWEX - The Global Energy and Water Cycle Experiment  

NASA Technical Reports Server (NTRS)

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

Chahine, Moustafa T.

1992-01-01

181

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

PubMed

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

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

2009-08-15

182

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

183

Energy profiling in the life-cycle assessment of buildings  

Microsoft Academic Search

Purpose – Building energy performance is a key element when assessing the sustainability, or otherwise, of the built environment. However, the prescriptive nature of current approaches to sustainability assessment stultifies innovative approaches to sustainable building design. The purpose of this paper is to illustrate how a current EU FP7-funded project, entitled “IntUBE – Intelligent Use of Buildings' Energy Information,” will

Tracey Crosbie; Nashwan Dawood; John Dean

2010-01-01

184

Transporting carbon dioxide recovered from fossil-energy cycles.  

National Technical Information Service (NTIS)

Transportation of carbon dioxide (CO(sub 2)) for enhanced oil recovery is a mature technology, with operating experience dating from the mid-1980s. Because of this maturity, recent sequestration studies for the US Department of Energy's National Energy Te...

R. Doctor J. Molburg J. Brockmeier

2000-01-01

185

Mass composition of primary cosmic rays at energies 1014-3×1015 eV  

Microsoft Academic Search

The flux of hadrons at energies around 1013-1014 eV measured by the Mount Fuji experiment has been compared with fluxes predicted for different assumptions about the mass composition of primary cosmic rays. It is shown that agreement between experimental data and prediction can be obtained only if the average mass of the primaries does not increase significantly up to a

J. Kempa; J. Wdowczyk

1983-01-01

186

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

Code of Federal Regulations, 2010 CFR

...waste concerning natural gas as the primary energy source for qualifying small power production facilities...waste concerning natural gas as the primary energy source for qualifying small power production facilities...deciding whether natural gas may be considered...

2010-04-01

187

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

Code of Federal Regulations, 2010 CFR

...waste concerning natural gas as the primary energy source for qualifying small power production facilities...waste concerning natural gas as the primary energy source for qualifying small power production facilities...deciding whether natural gas may be considered...

2009-04-01

188

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

189

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

SciTech Connect

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

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

1996-07-01

190

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

191

Energy Consumption in the Primary Agricultural Sector in 1982/1983. The Present Situation and Prospects.  

National Technical Information Service (NTIS)

In this report consumption in the primary agricultural sector, comprising agriculture, horticulture and forestry, is estimated for 1982/83. Direct consumption comprises energy in the form of diesel oil, electricity and fuel gas oil used on farms. Indirect...

M. Parsby M. M. Fog

1984-01-01

192

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

193

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

194

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

195

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

Federal Register 2010, 2011, 2012, 2013

The U.S. Department of Energy (DOE) announces the availability of the Hydrogen Energy California's Integrated Gasification Combined Cycle Project Preliminary Staff Assessment/Draft Environmental Impact Statement (PSA/DEIS) (DOE/EIS-0431D) for public review and comment. This document is the draft environmental impact statement for DOE's purpose of complying with the National Environmental Policy......

2013-07-22

196

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

Microsoft Academic Search

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

Irakli Loladze; Yang Kuang; James J. Elser

2000-01-01

197

Life Cycle Assessment (LCA) of Chinese energy chains for Shandong electricity scenarios  

Microsoft Academic Search

The Life Cycle Assessment (LCA) performed for the China Energy Technology Program (CETP) has established streamlined environmental inventories of coal, nuclear, natural gas, and wind energy systems for supply of electricity to Shandong province with a 20 years time horizon. This paper deals with selected results for air pollutants obtained for the current coal technology and the comparison of current

Roberto Dones; Xin Zhou; Chunxiu Tian

2004-01-01

198

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

199

Hydrogen production from solar energy powered supercritical cycle using carbon dioxide  

Microsoft Academic Search

A hydrogen production method is proposed, which utilizes solar energy powered thermodynamic cycle using supercritical carbon dioxide (CO2) as working fluid for the combined production of hydrogen and thermal energy. The proposed system consists of evacuated solar collectors, power generating turbine, water electrolysis, heat recovery system, and feed pump. In the present study, an experimental prototype has been designed and

Xin-Rong Zhang; Hiroshi Yamaguchi; Yuhui Cao

2010-01-01

200

Metabolic futile cycles and their functions: a systems analysis of energy and control.  

PubMed

It has long been hypothesised that futile cycles in cellular metabolism are involved in the regulation of biochemical pathways. Following the work of Newsholme and Crabtree, a quantitative theory was developed for this idea based on open-system thermodynamics and metabolic control analysis. It is shown that the stoichiometric sensitivity of an intermediary metabolite concentration with respect to changes in steady-state flux is governed by the effective equilibrium constant of the intermediate formation, and the equilibrium can be regulated by a futile cycle. The direction of the shift in the effective equilibrium constant depends on the direction of operation of the futile cycle. High stoichiometric sensitivity corresponds to ultrasensitivity of an intermediate concentration to net flow through a pathway; low stoichiometric sensitivity corresponds to super-robustness of concentration with respect to changes in flux. Both cases potentially play important roles in metabolic regulation. Futile cycles actively shift the effective equilibrium by expending energy; the magnitude of changes in effective equilibria and sensitivities is a function of the amount of energy used by a futile cycle. This proposed mechanism for control by futile cycles works remarkably similar to kinetic proofreading in biosynthesis. The sensitivity of the system is also intimately related to the rate of concentration fluctuations of intermediate metabolites. The possibility of different roles for the two major mechanisms within cellular biochemical regulation, namely reversible chemical modifications via futile cycles and shifting equilibrium by macromolecular binding, are discussed. PMID:16986621

Qian, H; Beard, D A

2006-07-01

201

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

ScienceCinema

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

Balsara, Nitash

2011-06-03

202

Carbon Cycle 2.0: Lynn Price: energy demand in China  

ScienceCinema

Lynn Price 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/

Lynn Price

2010-09-01

203

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

Microsoft Academic Search

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

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

2009-01-01

204

Carbon Cycle 2.0: Lynn Price: energy demand in China  

SciTech Connect

Lynn Price 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/

Lynn Price

2010-02-09

205

Electron showers of high primary energy in lead.  

NASA Technical Reports Server (NTRS)

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

Mueller, D.

1972-01-01

206

ARIMA forecasting of primary energy demand by fuel in Turkey  

Microsoft Academic Search

Forecasting of energy demand in emerging markets is one of the most important policy tools used by the decision makers all over the world. In Turkey, most of the early studies used include various forms of econometric modeling. However, since the estimated economic and demographic parameters usually deviate from the realizations, time-series forecasting appears to give better results. In this

Volkan ?. Ediger; Sertaç Akar

2007-01-01

207

Atomic-Resolution STEM at Low Primary Energies.  

National Technical Information Service (NTIS)

Aberration correction of the scanning transmission electron microscope (STEM) has made it possible to reach probe sizes close to 1 A at 60 keV, an operating energy that avoids direct knock-on damage in materials consisting of light atoms such as B, C, N a...

M. F. Chisholm M. F. Murfitt N. Dellby O. L. Krivanek

2013-01-01

208

Primary Energy Spectrum as Reconstructed from S(500) Measurements by KASCADE-Grande  

NASA Astrophysics Data System (ADS)

In cosmic ray investigations by observations of extensive air showers (EAS) the general question arises how to relate the registered EAS observables to the energy of the primary particle from the cosmos entering into the atmosphere. We present results on the reconstruction of the primary energy spectrum of cosmic rays from the experimentally recorded S(500) observable using the KASCADE-Grande detector array. The KASCADE-Grande experiment is installed in Forschungszentrum Karlsruhe, Germany, and driven by an international collaboration. Previous EAS investigations have shown that for a fixed energy the charged particle density becomes independent of the primary mass at certain distances from the shower core. This feature can be used as an estimator for the primary energy. The particular radial distance from the shower core where this effect shows up is a characteristic of the detector. For the KASCADE-Grande experiment it was shown to be around 500 m, hence a notation S(500). Extensive simulation studies have shown that S(500) is mapping the primary energy. The constant intensity cut (CIC) method is applied to evaluate the attenuation of the S(500) observable with the zenith angle. An attenuation correction is applied and all recorded S(500) values are corrected for attenuation. A calibration of S(500) values with the primary energy has been worked out by simulations and was used for conversion providing the possibility to obtain the primary energy spectrum (in the energy range accessible to KASCADE-Grande 1010-1018 eV). The systematic uncertainties induced by different factors are considered.

Toma, G.; Apel, W. D.; Arteaga, J. C.; Badea, F.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Finger, M.; Fuhrmann, D.; Ghia, P. L.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Klages, H. O.; ?uczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Oehlschläger, J.; Ostapchenko, S.; Over, S.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schröder, F.; Sima, O.; Stümpert, M.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.

2010-01-01

209

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

210

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

211

Estimation model for the life cycle energy consumption for highway transport  

SciTech Connect

Present methods of highway evaluation include consideration and analysis of such factors as cost, safety, environment, and aesthetics, but do not directly entail energy consequences of the decision. This research investigated the major energy-consuming activities, related to rural highways, which may be altered by highway officials. The treatise presents a method for estimating the total energy consumption for the highway alternatives during their life cycles. Various alternatives may be compared to determine which is least energy consuming by selecting an optimum balance between initial and long-term energy consumption. This research formulated the life cycle energy estimate for various highway geometric and structural conditions. The total estimate is the summation of the energy expenditure for vehicle fuel consumption, construction, and major maintenance. Steep grades, rough and uneven surfaces, and sharp curvatures notably increase vehicle consumption. The construction of new or improved routes to eliminate these conditions may be justified on a life cycle energy basis. That is, the extra expenditure of energy to construct these improvements may be more than offset by the energy savings or lower fuel consumption of vehicles traveling on these improved roads. Therefore, each highway design or improvement must be evaluated on an individual basis by comparing the energy expenditure for construction and maintenance with the vehicle fuel savings. For utilizing the life cycle energy model, the user should be cognizant that the system's results are sensitive to variations in the estimates of traffic growth, the truck portion of the vehicle fleet, and vehicle fuel price. On the other hand, the model is relatively insensitive to variations of the constructive and maintenance estimates.

McIvor, G.T.

1981-01-01

212

Biologically enhanced energy and carbon cycling on Titan?  

PubMed

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

Schulze-Makuch, Dirk; Grinspoon, David H

2005-08-01

213

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

SciTech Connect

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

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

2010-07-25

214

[Menstrual cycle and surgery of breast cancer. Point of time for the surgery of primary breast cancer in connection with menstrual cycle is without prognostic significance].  

PubMed

From 1977 to 1989 6488 patients under fifty years with primary breast cancer were registered in the nationwide Danish Breast Cancer Cooperative Group (DBCG). Among these information on last menstrual period prior to surgery was available in 1635 cases which constitute the study group of the present analysis. The group was representative of the total group with regard to prognostic factors and survival. In the study group time of surgery in relation to last menstrual period was found to have no influence on five- and ten year survival. PMID:7483079

Kroman, N T; Højgaard, A D; Andersen, K W; Graversen, H P; Afzelius, P; Lokdam, A V; Juul, C; Hoffmann, J; Bentzon, N; Mouridsen, H T

1995-10-23

215

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.

Diederichs, Frank

2012-01-01

216

Noncatalytic dissociation of MgO by laser pulses towards sustainable energy cycle  

NASA Astrophysics Data System (ADS)

We succeeded in dissociating MgO using laser pulses without a reducing agent. The energy efficiency from laser to magnesium reaction energy exceeded 42.5%. Although 1 kW CO2 cw laser and Nd-YAG pulse laser are used in this experiment, the laser can be pumped by natural resources such as solar light or wind power. Thus natural resources are stored in the form of magnesium, which can be used through the reaction with water whenever we need the energy, and thus a renewable energy system will be established. This paper reports the preliminary experiments of MgO reduction toward a sustainable energy cycle.

Yabe, T.; Mohamed, M. S.; Uchida, S.; Baasandash, C.; Sato, Y.; Tsuji, M.; Mori, Y.

2007-06-01

217

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

218

A Model for Primary Diesel Fuel Atomization Based on Cavitation Bubble Collapse Energy  

Microsoft Academic Search

A diesel spray atomization model has been developed in the framework of the three-dimensional fluid dynamics code KIVA-3V and validated with experimental data. This atomization model accounts for cavitation bubble collapse energy, turbulent kinetic energy, and aerodynamic forces on the liquid core. The primary breakup time is computed by a balance between surface tension of the liquid core, the aerodynamic

A. Nishimura

2000-01-01

219

Applying sustainable technology for saving primary energy in the brewhouse during beer brewing  

Microsoft Academic Search

Wort boiling is the most energy intensive stage in the brewing process. For this reason considerable attention has been given to improve the efficiency of wort boiling systems. Alternative wort boiling technologies, such as low pressure boiling and high temperature wort boiling, have been studied in detail during the last decades, with a focus on the reduction of primary energy

Ronnie G. Willaert; Gino V. Baron

2004-01-01

220

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

221

Seasonal cycle of solar energy fluxes through Arctic sea ice  

NASA Astrophysics Data System (ADS)

Arctic sea ice has not only decreased considerably during the last decades, but also changed its physical properties towards a thinner and more seasonal cover. These changes strongly impact the energy budget and might affect the ice-associated ecosystem of the Arctic. But until now, it is not possible to quantify shortwave energy fluxes through sea ice sufficiently well over large regions and during different seasons. Here, we present a new parameterization of light transmittance through sea ice for all seasons as a function of variable sea ice properties. The annual maximum solar heat flux of 30 × 105 J m-2 occurs in June, then also matching the under ice ocean heat flux. Furthermore, our results suggest that 96% of the total annual solar heat input occurs from May to August, during four months only. Applying the new parameterization on remote sensing and reanalysis data from 1979 to 2011, we find an increase in light transmission of 1.5% a-1 for all regions. Sensitivity studies reveal that the results strongly depend on the timing of melt onset and the correct classification of ice types. Hence, these parameters are of great importance for quantifying under-ice radiation fluxes and the uncertainty of this parameterization. Assuming a two weeks earlier melt onset, the annual budget increases by 20%. Continuing the observed transition from Arctic multi- to first year sea ice could increase light transmittance by another 18%. Furthermore, the increase in light transmission directly contributes to an increase in internal and bottom melt of sea ice, resulting in a positive transmittance-melt feedback process.

Arndt, S.; Nicolaus, M.

2014-06-01

222

The Energy Spectrum and the Chemical Composition of Primary Cosmic Rays with Energies from 1014 to 1016 eV  

NASA Astrophysics Data System (ADS)

We have measured extensive air showers with primary energies above 6 TeV at Mount Chacaltaya in Bolivia. The data were collected by an air shower array called the Minimum Air Shower (MAS) array starting in 2000 March. We applied an equi-intensity analysis method to the extensive air showers extended over the region of their maximum development. We varied the mixture of protons and iron in our simulations and compared these to the data to determine the mixing ratio of protons as a function of the primary energy. Using this, we derived the primary energy spectrum from 1014 to 5×1016 eV. Consequently, we conclude that the power-law index of the spectrum changes gradually around 1015.5 eV and that the obtained proton ratio decreases with increasing energy. We directly measured the longitudinal development of air showers generated by primaries with energies around the knee. We found that the average mass number of primary cosmic rays shows a steady increase with energy above 1014.5 eV and that the dominant component around the knee is not protons.

Ogio, S.; Kakimoto, F.; Kurashina, Y.; Burgoa, O.; Harada, D.; Tokuno, H.; Yoshii, H.; Morizawa, A.; Gotoh, E.; Nakatani, H.; Nishi, K.; Shimoda, S.; Tajima, N.; Yamada, Y.; Kaneko, T.; Murakami, K.; Toyoda, Y.; Matsubara, Y.; Mizumoto, Y.; Shirasaki, Y.; Tsunesada, Y.; Miranda, P.; Velarde, A.

2004-09-01

223

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

PubMed

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

Bravo, L; Ferrer, I

2011-01-01

224

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

225

Forecasting the primary energy demand in Turkey and analysis of cyclic patterns  

Microsoft Academic Search

The planning and estimation of future energy demand via modern statistical methods have been officially used in Turkey since 1984. However, almost all previous forecasts proved significantly higher than actual observations because of several reasons discussed here. The cycle analysis, which is a semi-statistical technique that makes use of any cyclicity in the historical data of annual additional amounts of

Volkan ?. Ediger; Hüseyin Tatl?dil

2002-01-01

226

The energy cycle and structural evolution of cyclones over southeastern South America in three case studies  

NASA Astrophysics Data System (ADS)

In this paper, the Lorenz energy cycle over a limited area was applied for three cyclones with different origins and evolutions, where each of them was formed in an important cyclogenetic region near southeastern South America. The synoptic conditions and energetics were analyzed during each system's life cycle and showed important relationships between their energy cycle and the evolution of their vertical structure. In the case of the weak baroclinic cyclone which formed on Brazil's south-southeastern coast, the analysis showed that it originated through a midlevel cutoff low with contribution from barotropic instability. Its evolution would indicate potential transition to a hybrid system if the convective activity were stronger. The system that occurred in the La Plata River mouth had features of an oceanic bomb-type cyclogenesis and showed an important contribution from the available potential energy generation term through the latent heat release by the convection. Meanwhile, the system of the southern Argentina coast presented a classical baroclinic development of extratropical cyclogenesis in the energy cycle, from the wave amplification up to the final occlusion of the associated frontal system. These analyses revealed that the development of some cyclones that occur in eastern South America can present different mechanisms that are not related to the classical extratropical cyclogenesis.

Dias Pinto, JoãO. Rafael; Da Rocha, Rosmeri PorfíRio

2011-07-01

227

Coupling a groundwater model with a land surface model to improve water and energy cycle simulation  

NASA Astrophysics Data System (ADS)

The water and energy cycles interact, making them generally closely related. Land surface models (LSMs) can describe the water and energy cycles of the land surface, but their description of the subsurface water processes is oversimplified, and lateral groundwater flow is ignored. Groundwater models (GWMs) well describe the dynamic movement of subsurface water flow, but they cannot depict the physical mechanism of the evapotranspiration (ET) process in detail. In this study, a coupled model of groundwater with simple biosphere (GWSiB) is developed based on the full coupling of a typical land surface model (SiB2) and a three-dimensional variably saturated groundwater model (AquiferFlow). In this model, the infiltration, ET and energy transfer are simulated by SiB2 via the soil moisture results given by the groundwater flow model. The infiltration and ET results are applied iteratively to drive the groundwater flow model. The developed model is then applied to study water cycle processes in the middle reaches of the Heihe River Basin in the northwest of China. The model is validated through data collected at three stations in the study area. The stations are located in a shallow groundwater depth zone, a deeper groundwater depth zone and an agricultural irrigation area. The study results show that the coupled model can well depict the land surface and groundwater interaction and can more comprehensively and accurately simulate the water and energy cycles compared with uncoupled models.

Tian, W.; Li, X.; Wang, X.-S.; Hu, B. X.

2012-01-01

228

Energy Use and Emissions from Marine Vessels: A Total Fuel Life Cycle Approach  

Microsoft Academic Search

Regional and global air pollution from marine transportation is a growing concern. In discerning the sources of such pollution, researchers have become interested in tracking where along the total fuel life cycle these emissions occur. In addition, new efforts to introduce alternative fuels in marine vessels have raised questions about the energy use and environmental impacts of such fuels. To

James J. Winebrake; James J. Corbett; Patrick E. Meyer

2007-01-01

229

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

National Technical Information Service (NTIS)

We estimated the effects on per-vehicle-mile fuel-cycle petroleum use, greenhouse gas (GHG) emissions, and energy use of using ethanol blended with gasoline in a mid-size passenger car, compared with the effects of using gasoline in the same car. Our anal...

M. Wang C. Saricks D. Santini

1999-01-01

230

LIFE-CYCLE INVENTORY OF MEDIUM DENSITY FIBERBOARD IN TERMS OF RESOURCES, EMISSIONS, ENERGY AND CARBON  

Microsoft Academic Search

Life-cycle inventory (LCI) data are needed to scientifically document the environmental performance of materials for applications as governed by the many new green building standards, purchasing guidelines, and energy and climate change policy issues. This study develops the LCI data for medium-density fiberboard (MDF), a composite wood panel product comprised of wood fibers, urea- formaldehyde resin, wax, and other additives.

James B. Wilson

2010-01-01

231

Factors controlling evaporation and energy partitioning beneath a deciduous forest over an annual cycle  

Microsoft Academic Search

The energy balance components were measured above the ground surface of a temperate deciduous forest over an annual cycle using the eddy covariance technique. Over a year, the net radiation at the forest floor was 21.5% of that above the canopy, but this proportion was not constant, primarily because of the distinct phenological stages separated by the emergence and senescence

Kell B. Wilson; Paul J. Hanson; Dennis D. Baldocchi

2000-01-01

232

A novel hybrid oxy-fuel power cycle utilizing solar thermal energy  

Microsoft Academic Search

An advanced oxy-fuel hybrid power system (AHPS) is proposed in this paper. Solar thermal energy is used in the AHPS to produce saturated steam as the working fluid, and natural gas is internally combusted with pure oxygen. It is in configuration close to the zero emission Graz cycle. The thermodynamic characteristics at design conditions of the AHPS are analyzed using

Chenhua Gou; Ruixian Cai; Hui Hong

2007-01-01

233

MEGHA-TROPIQUES, a satellite for studying the water cycle and energy exchanges in the tropiques  

Microsoft Academic Search

Supported by the French and Indian scientific communities, the MEGHA-TROPIQUES Mission aims at studying the water cycle and the energy exchanges in the tropical belt. It will be jointly developed by the Indian Space Research Organisation (ISRO) and the French Space Agency (CNES). The small satellite (<600 kg) could be launched as early as 2005 by Indian PSLV launcher in

J. P. Aguttes; J. Schrive; C. Goldstein; M. Rouze; G. Raju

2000-01-01

234

Analysis of a Power Cycle Utilizing Low-Grade Solar Energy  

Microsoft Academic Search

This paper has proposed a power system that can provide efficiently using the heat collected by the collector. The system consists a of the Rankine cycle to recover the collected solar energy. It produces power and provides certain amount of domestic hot water. Based on the models, a calculation was done to analysis the performance of the system at the

Jianzhong Song; Xiaosong Zhang

2010-01-01

235

Real-time per-cycle energy consumption measurement of digital systems  

Microsoft Academic Search

This technical report introduces a real-time per-clock-cycle energy measurement technique for power analysis and reduction of synchronous state machines. This technique guarantees accuracy with a sampling rate of twice the clock frequency under spiky current draw common in digital systems. In addition, it acquires the energy consumption profile in real-time, thus, not requiring repeated operation of the target system.

Naehyuck Chang; Kwanho Kim

2000-01-01

236

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

Microsoft Academic Search

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

G. R. Heidenreich; M. B. Parekh

1986-01-01

237

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

PubMed

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

Vignais, Paulette M

2008-01-01

238

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

239

"You Just Have to Take a Bit of a Risk Sometimes": Breaking the "Cycle of Tradition" in Primary Mathematics  

ERIC Educational Resources Information Center

The purpose of this study was to explore the mathematics teaching practices of graduates of a pre-service primary/early childhood education program designed to develop teachers' capacities to implement non-traditional mathematics curricula. As a complementary component of a large survey study of graduate teachers, graduates were interviewed to…

Frid, Sandra; Sparrow, Len

2009-01-01

240

The Energy Spectrum and the Chemical Composition of Primary Cosmic Rays with Energies from 1014 to 1016 eV  

Microsoft Academic Search

We have measured extensive air showers(EASs) with primary energies above 6 TeV at Mt. Chacaltaya in Bolivia since March 2000 with an air shower array called the Minimum Air Shower(MAS) array. With an equi-intensity method analysis, we obtained longitudinal development curves of EAS around and deep er than their maximum developments to be compared with simulations, in which the primary

S. Ogio; F. Kakimoto; Y. Kurashina; Y. Tsunesada; Y. Shirasaki; O. Burgoa; E. Gotoh; D. Harada; K. Kadota; T. Kaneko; Y. Matsubara; P. Miranda; Y. Mizumoto; A. Morizawa; K. Murakami; H. Nakatani; K. Nishi; S. Shimoda; N. Tajima; M. Teshima; H. Tokuno; Y. Toyoda; A. Velarde; Y. Yamada; H. Yoshii

2003-01-01

241

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

242

Comparison of biomolecule desorption yields for low and high energy primary ions  

NASA Astrophysics Data System (ADS)

Ion induced desorption yields of molecular ions from samples of cesium iodide, glycylglcine, ergosterol, bleomycin and a trinucleoside diphosphate have been studied using primary beams of 54 MeV 63Cu 9+ and 3 keV 133Cs +. Mass analysis was performed with a time-of-flight technique. Each sample was studied with the same spectrometer for both low and high energy primary ions and without opening of the vacuum chamber in between the measurements. The results show that fast heavy ions give larger yields for all samples studied and that the yield ratios for high to low energy desorption increase with the mass of the sample molecule.

Kamensky, I.; Håkansson, P.; Sundqvist, B.; McNeal, C. J.; Macfarlane, R.

1982-07-01

243

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

244

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

245

Catalyst Needs for Thermochemical Hydrogen Production Cycles  

Microsoft Academic Search

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

Daniel M. Ginosar; Lucia M. Petkovic; Harry W. Rollins; Kyle C. Burch

2007-01-01

246

Vacuum thermal cycle life testing of high temperature thermal energy storage  

NASA Astrophysics Data System (ADS)

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

Ponnappan, Rengasamy; Beam, Jerry E.

247

Chemical composition of primary cosmic rays with energies around the knee region observed at Mt. Chacaltaya  

NASA Astrophysics Data System (ADS)

The chemical composition of primary cosmic rays around the knee region has been investigated with an air shower array at Mt.Chacaltaya. From 1987 to 1991, we examined observed equi-intensity curves comparing those with a Monte Carlo simulation where the primary composition is assumed to be a mixture of protons and Fe nuclei, and obtained the their mixing ratio as a function of the primary energy(Ogio et al., 2001). Moreover, from 1995 to 1997, we made a measurement of arrival time distributions of air ?Cerenkov light. From an analysis of arrival time distributions of ?Cerenkov light, we obtained the composition as a mixture of proton, He, CNO, Si-Mg, Fe groups(Shirasaki et al., 2001). Both the results show that the average mass number of primary nuclei ln A gradually increases up to ˜ 2 around the knee region and up to ˜ 3 around 1016 eV. In 1999, we improved our array to observe air showers with lower primary energies. Furthermore, we installed five detectors in the array to measure the lateral distribution of air ?Cerenkov light. Now we examine the chemical composition of primary cosmic rays above 5 × 1012 eV more precisely with air ?Cerenkov light data and an equi-intensity curve analysis. References Ogio, S., et al., Il Nuovo Cimento C, 24,2001.(to be published) Shirasaki, Y., et al., Astropart. Phys., 15,241-257, 2001.

Ogio, S.; Yoshii, H.; Tsunesada, Y.; Kakimoto, F.; Tajima, N.; Tokuno, H.; Harada, D.; Kaneko, T.; Shimoda, S.; Morihisa, T.; Kuwata, Y.; Morizawa, A.; Nakamitsu, S.; Okamoto, K.; Burgoa, O.; Kurashina, Y.; Nishi, K.; Murakami, K.; Toyoda, Y.; Matsubara, Y.; Shirasaki, Y.; Kadota, K.; Mizumoto, Y.; Yamada, Y.; Nakatani, H.; Gotoh, E.; Miranda, P.; Velarde, A.

248

Life-cycle energy demand and global warming potential of computational logic.  

PubMed

Computational logic, in the form of semiconductor chips of the complementary metal oxide semiconductor (CMOS) transistor structure, is used in personal computers, wireless devices, IT network infrastructure, and nearly all modem electronics. This study provides a life-cycle energy analysis for CMOS chips over 7 technology generations with the purpose of comparing energy demand and global warming potential (GWP) impacts of the life-cycle stages, examining trends in these impacts over time and evaluating their sensitivity to data uncertainty and changes in production metrics such as yield. A hybrid life-cycle assessment (LCA) model is used. While life-cycle energy and GWP of emissions have increased on the basis of a wafer or die, these impacts have been reducing per unit of computational power. Sensitivity analysis of the model shows that impacts have the highest relative sensitivity to wafer yield, line yield, and die size and largest absolute sensitivity to the use-phase power demand of the chip. PMID:19848138

Boyd, Sarah B; Horvath, Arpad; Dornfeld, David

2009-10-01

249

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

PubMed

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

Frijia, Stephane; Guhathakurta, Subhrajit; Williams, Eric

2012-02-01

250

variability of specific coccolith caco3 weight, and primary production in the western pacific warm pool during the last glacial cycle  

NASA Astrophysics Data System (ADS)

The coccolithophorides are a major planktonic group producing calcite. Their contribution to the production of pelagic carbonate is difficult to estimate, because single coccoliths cannot be isolated and weighted. That value is however important to understand when one want to discuss carbon cycle and alkalinity variations. A method was developed to measure indirectly the CaCO3 coccolith content, from image analysis, using the measured brightness of carbonate grains viewed in cross-polarized light (birefringence). With the use of SYRACO, an automated coccolith image grabber able to recognise 11 species, it is possible to estimate the weight of thousands of individual coccoliths in a sample using that method. The individual weight of 3 taxa (Gephyrocapsa oceanica, small placoliths and Florisphaera profunda) was measured from samples collected in core tops sediments from the Indian and Pacific oceans and in Core MD97-2138 retrieved in the western Pacific warm pool. The mean weight appears to increase with the specific primary production. The weight of F. profunda increases during dominance events of this group. These events mark low productivity period related to an ENSO-like cycle having a 23-kyr period. Conversely, the weight of G. oceanica and of the small placoliths decreases during these events. We suspect therefore that the coccolith CaCO3 production is related to primary production and that is general increased during glacial periods in low latitude.

Beaufort, L.; Buchet, N.

2003-04-01

251

The Annual Cycle of the Energy Budget: Global mean and Land-Ocean Exchanges  

NASA Astrophysics Data System (ADS)

The mean and annual cycle of energy flowing into the climate system and its storage, release, and transport in the atmosphere, ocean, and land surface are estimated with recent observations. An emphasis is placed on establishing internally consistent quantitative estimates with a full discussion and assessment of uncertainty. At the top-of-atmosphere (TOA), adjusted Earth Radiation Budget Experiment (ERBE) and Clouds and the Earth's Radiant Energy System (CERES) satellite retrievals are used, while in the atmosphere NCEP/NCAR and ECMWF reanalysis (ERA-40) estimates are used. The net upward surface flux (Fs) over ocean is derived from the residual of TOA and atmospheric budgets, and is compared with direct calculations of ocean heat content (Oe) and its tendency from several ocean temperature datasets. Over land Fs from a stand-alone simulation of the Community Land Model forced by observed fields is used. The near balance between net TOA radiation (R) and Fs over ocean and thus with Oe, and between R and atmospheric total energy divergence over land, are documented both in the mean and for the annual cycle. However, there is an annual mean transport of energy by the atmosphere from ocean to land regions of 2.2±0.1 PW primarily in the northern winter when the transport exceeds 5 PW. The global albedo is dominated by a semiannual cycle over the oceans, but combines with the large annual cycle in solar insolation to produce a peak in absorbed and net radiation in February, somewhat after the perihelion, and with the net radiation 4.3 PW higher than the annual mean, as it is enhanced by the annual cycle of outgoing long-wave radiation that is dominated by land regions. In situ estimates of the annual variation of Oe are found to be unrealistically large.

Trenberth, K. E.; Fasullo, J. T.

2007-05-01

252

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

SciTech Connect

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

C. Saricks; D. Santini; M. Wang

1999-02-08

253

Two-dimensional free energy surfaces for primary electron transfer in a photosynthetic reaction center  

NASA Astrophysics Data System (ADS)

Two-dimensional free energy surfaces for primary electron transfer in a bacterial photosynthetic reaction center are constructed from the MD simulation results by Warshel et al. [J. Photochem. Photobiol. A: Chem 82 (1994) 123] on the same system by choosing the reaction coordinates appropriately. The activation energies for the direct and sequential electron transfer are calculated using these surfaces. One needs these two-dimensional free energy surfaces to analyze the dynamical solvent effect on the competition between the direct and sequential electron transfer properly, although this effect has so far been analyzed by using one-dimensional free energy curves.

Fushiki, M.; Tachiya, M.

1996-06-01

254

The modulation of low energy galactic cosmic rays over solar maximum (cycle 20)  

NASA Technical Reports Server (NTRS)

A preliminary report is presented on detailed observations of low energy approximately (60 MeV/nucleon) galactic cosmic rays made during the recent period of solar maximum. For this particular cycle a significant time lag between intensity changes in the low energy and high energy components was observed. There are a number of possible explanations of this hysteresis effect. In the simplest form these include either changes in the form of the magnetic field power spectrum or changes in the size of the effective modulating region, or both.

Vanhollebeke, M. A. I.; Wang, J. R.; Mcdonald, F. B.

1972-01-01

255

Extended cycling behavior of a direct contact-phase change TES (thermal energy storage) system  

SciTech Connect

The extended cycling behavior of a direct contact-phase change TES (thermal energy storage) system was determined in a 200 l. unit with aqueous disodium phosphate as the storage material and Exxon Marcol 72R as the immiscible heat transfer fluid (HTF). The average cooling and heating efficiencies after cycling for 22 days were 72 and 66.4%, respectively. The concentration of salt hydrate in the HTF increased with time, and salt deposition from the HTF occurred on cool heat exchanger surfaces during the cooling cycles. However, no decrease in efficiency occurred with time, and it was concluded that the direct contact phase change TES concept is technically feasible. The most promising heat transfer fluids are mineral oil and certain commercial heat transfer fluids.

Mills, A.D.; Melsheimer, S.s.; Edie, D.D.

1980-01-01

256

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

EPA Science Inventory

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

257

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

258

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

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

259

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

260

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

261

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

SciTech Connect

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

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

1998-01-01

262

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

PubMed

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

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

2013-10-01

263

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

264

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

NASA Astrophysics Data System (ADS)

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

Turiel, I.

1981-10-01

265

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

PubMed

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

Cao, Yucheng; Paw?owski, Artur

2013-01-01

266

Computer Simulation Of Energy Dependence Of Primary Damage States In SiC  

SciTech Connect

The primary damage state in 3C-SiC has been comprehensively studied by molecular dynamics using a modified Tersoff potential. The simulations examined damage produced by Si and C primary knock-on atoms (PKA) with energies from 0.25 to 30 keV. The study also generated statistics of defect production by simulating a number of PKAs at each energy. The defect production efficiency decreases with increasing PKA energy, as observed previously in metals. However, the cascade lifetime is very short (less than 1 ps), localized melting does not occur, the defect arrangements are highly dispersed, and the tendency for defects to form clusters is much less compared to the case of metals. Frenkel pairs on the C sublattice are more numerous than Si Frenkel pairs, and 10-20% of the displacements are in the form of anti-site defects.

Devanathan, Ramaswami (ASSOC WESTERN UNIVERSITY); Gao, Fei (BATTELLE (PACIFIC NW LAB)); Weber, William J. (BATTELLE (PACIFIC NW LAB)); GE Lucas, LL Snead, MA Kirk, RG Elliman

2001-01-01

267

Energy use and emissions from marine vessels: a total fuel life cycle approach.  

PubMed

Regional and global air pollution from marine transportation is a growing concern. In discerning the sources of such pollution, researchers have become interested in tracking where along the total fuel life cycle these emissions occur. In addition, new efforts to introduce alternative fuels in marine vessels have raised questions about the energy use and environmental impacts of such fuels. To address these issues, this paper presents the Total Energy and Emissions Analysis for Marine Systems (TEAMS) model. TEAMS can be used to analyze total fuel life cycle emissions and energy use from marine vessels. TEAMS captures "well-to-hull" emissions, that is, emissions along the entire fuel pathway, including extraction, processing, distribution, and use in vessels. TEAMS conducts analyses for six fuel pathways: (1) petroleum to residual oil, (2) petroleum to conventional diesel, (3) petroleum to low-sulfur diesel, (4) natural gas to compressed natural gas, (5) natural gas to Fischer-Tropsch diesel, and (6) soybeans to biodiesel. TEAMS calculates total fuel-cycle emissions of three greenhouse gases (carbon dioxide, nitrous oxide, and methane) and five criteria pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides, particulate matter with aerodynamic diameters of 10 microm or less, and sulfur oxides). TEAMS also calculates total energy consumption, fossil fuel consumption, and petroleum consumption associated with each of its six fuel cycles. TEAMS can be used to study emissions from a variety of user-defined vessels. This paper presents TEAMS and provides example modeling results for three case studies using alternative fuels: a passenger ferry, a tanker vessel, and a container ship. PMID:17269235

Winebrake, James J; Corbett, James J; Meyer, Patrick E

2007-01-01

268

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

269

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

Microsoft Academic Search

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

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

1980-01-01

270

Evaluation of catalyst for closed cycle operation of high energy pulsed CO2 lasers  

NASA Technical Reports Server (NTRS)

Several catalyst materials have been tested for efficiency of converting CO and O2 to CO2 for use in a high energy CO2 laser. The composition of the gas mixtures was monitored by mass spectrometry and gas chromatography. A copper/copper oxide catalyst and a platinum/tin oxide catalyst were used for closed cycle operation of a CO2 laser (0.7 joules/pulse), operating at 10 pulses/sec.

Rogowski, R. S.; Miller, I. M.; Wood, G.; Schryer, D. R.; Hess, R. V.; Upchurch, B. T.

1983-01-01

271

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

272

Energy balance of the closed oxygen cycle and processes causing thermal runaway in valve-regulated lead\\/acid batteries  

Microsoft Academic Search

A model for the reactions involved in the closed oxygen cycle in valve-regulated lead\\/acid batteries and the associated energy transformations is proposed. When electric current flows through the closed oxygen cycle, a certain amount of electric energy is converted via electrochemical processes into chemical energy, i.e. the products obtained may interact spontaneously as a result of which the system returns

D. Pavlov

1997-01-01

273

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

274

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

SciTech Connect

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

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

2005-09-01

275

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

Microsoft Academic Search

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

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

2005-01-01

276

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.

277

Distinct bacterial-production-DOC-primary-production relationships and implications for biogenic C cycling in the South China Sea shelf  

NASA Astrophysics Data System (ADS)

Based on two summer spatio-temporal data sets obtained from the northern South China Sea shelf and basin, this study reveals contrasting relationships among bacterial production (BP), dissolved organic (DOC) and primary production (PP) in the transition zone from the neritic to the oceanic regions. Inside the mid-shelf (bottom depth <100 m), where inorganic nutrient supplies from river discharge and internal waves were potentially abundant, BP, DOC and PP were positively intercorrelated, whereas these three measurements became uncorrelated in the oligotrophic outer shelf and slope. We suggest that the availability of limiting minerals could affect the couplings/decouplings between the source (i.e. phytoplankton) and sink (i.e. bacteria) of organic carbon, and thus DOC dynamics. DOC turnover times were homogeneously low (37-60 days) inside the mid-shelf area and then increased significantly to values >100 days in the outer shelf, indicating that riverine (Pearl River) DOC might be more labile. The actual mechanism for this is unknown, but might relate to higher inorganic nutrient supply from river/terrestrial sources. The positive correlation of the BP / PP ratios vs. phosphate (and nitrate) concentrations in the inner shelf implies that if anthropogenic mineral loading keeps increasing in the foreseeable future, the near-shore zone may become more heterotrophic, rendering the system a stronger source of CO2.

Lai, C.-C.; Fu, Y.-W.; Liu, H.-B.; Kuo, H.-Y.; Wang, K.-W.; Lin, C.-H.; Tai, J.-H.; Wong, G. T. F.; Lee, K.-Y.; Chen, T.-Y.; Yamamoto, Y.; Chow, M.-F.; Kobayashi, Y.; Ko, C.-Y.; Shiah, F.-K.

2014-01-01

278

The effects of internal latent energy storage on the operational dynamics of a solar-powered absorption cycle  

Microsoft Academic Search

A system diagram and performance equations are presented for a solar-powered absorption cycle heat pump system utilizing latent energy storages internal to the absorption cycle itself. A water-lithium bromide absorption cycle heat pump directly coupled to a flat plate solar collector is considered. Generalized weather functions are used to represent insolation and heating\\/cooling load inputs to the model. All collected

A. W. Harris; C. N. Shen

1978-01-01

279

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

280

Analyzing the Life Cycle Energy Savings of DOE Supported Buildings Technologies  

SciTech Connect

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

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

2009-08-31

281

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

SciTech Connect

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

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

2006-11-01

282

The energy-cycle analysis of the interactions between shallow and deep atmospheric convection  

NASA Astrophysics Data System (ADS)

Interactions between different convection modes can be investigated using an energy-cycle description under a framework of mass-flux parameterization. The present paper systematically investigates this system by taking a limit of two modes: shallow and deep convection. Shallow convection destabilizes itself as well as the other convective modes by moistening and cooling the environment, whereas deep convection stabilizes itself as well as the other modes by drying and warming the environment. As a result, shallow convection leads to a runaway growth process in its stand-alone mode, whereas deep convection simply damps out. Interaction between these two convective modes becomes a rich problem, even when it is limited to the case with no large-scale forcing, because of these opposing tendencies. Only if the two modes are coupled at a proper level can a self-sustaining system arise, exhibiting a periodic cycle. The present study establishes the conditions for self-sustaining periodic solutions. It carefully documents the behaviour of the two mode system in order to facilitate the interpretation of global model behaviours when this energy-cycle is implemented as a closure into a convection parameterization in future.

Plant, Robert S.; Yano, Jun-Ichi

2013-11-01

283

Megha-Tropiques: a Joint French and Indian Mission to Study Water Cycle and Energy Exchanges in the Tropiques  

Microsoft Academic Search

ISRO and CNES organisations have signed an agreement in May 2001 to carry out Phase B studies of the MEGHA-TROPIQUES mission. MEGHA-TROPIQUES is a satellite mission designed to study convective systems, focusing on the analysis of water cycle with water vapour distribution and transport, convective systems life cycle and energy exchanges in the tropical belt. The science goal is to

N. Karouche

2002-01-01

284

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

Microsoft Academic Search

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

I Kimura

1995-01-01

285

CEP-Stable, Few-Cycle, kHz OPCPAs for Attosecond Science: Energy Scaling and Coherent Sub-Cycle Pulse Synthesis  

NASA Astrophysics Data System (ADS)

We report on the energy scaling and coherent waveform synthesis of a carrier-envelope phase (CEP)-stable, few-cycle, kHz-repetition-rate optical parametric chirped-pulse amplifiers (OPCPAs) for high-field physics applications. First, amplification of ultrabroadband 2.1 -? m pulses to 0.85 mJ is demonstrated using a novel high-energy, ps, cryogenic Yb:YAG pump laser. Pulse compression to 4.5 optical cycles has been achieved. Initial high-harmonic generation (HHG) experiments with Xe have shown a significant cutoff extension to >85 eV. Second, we have coherently synthesized the 2.1 -? m pulse with a CEP-stable, few-cycle near-infrared OPCPA pulse seeded by the same laser oscillator and generated a 15 -? J sub-cycle waveform. Simulations confirm that this waveform is suitable for isolated attosecond pulse generation. The pulse synthesis method can be extended to a novel energy-scalable wavelength multiplexing scheme based on multi-color OPCPAs.

Hong, Kyung-Han; Huang, Shu-Wei; Moses, Jeffrey; Fu, Xing; Cirmi, Giovanni; Lai, Chien-Jen; Bhardwaj, Siddharth; Kärtner, Franz X.

286

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

287

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

Cancer.gov

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

288

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

Microsoft Academic Search

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

Xunmin Ou; Yan Xiaoyu; Xiliang Zhang

2011-01-01

289

Modeling the water and energy cycles in the upper Tone River Basin, Japan  

NASA Astrophysics Data System (ADS)

As a distributed biosphere hydrological model, the WEB-DHM (water and energy budget-based distributed hydrological model) enabled consistent descriptions of water, energy and CO2 fluxes at a basin scale. In the study, the WEB-DHM has been applied to the upper Tone River Basin where flux observations are not available. The model facilitates a better understanding of the water and energy cycles in this region. After being calibrated with discharge data, WEB-DHM is assessed against observed streamflows at 4 major gauges and MODIS Land Surface Temperature (LST). Results show that long-term streamflows including annual largest floods are well reproduced. As well, both daytime and nighttime LSTs simulated by WEB-DHM agree well with MODIS observations for both basin-averaged values and spatial patterns. The validated model is then used to analyze water and energy cycles of the upper Tone River Basin. The upper Tone River Basin Observed and simulated hourly annual largest flood peaks at main stream gauges from 2001 to 2004.

Wang, L.; Koike, T.; Yang, K.

2009-12-01

290

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.

291

Methods for determining the primary energy of cosmic-ray showers  

NASA Astrophysics Data System (ADS)

Monte Carlo simulations of cosmic-ray-induced showers in the atmosphere have been used to develop three new methods for measuring the energy of the primary particles in the 0954-3899/23/11/020/img6 - 0954-3899/23/11/020/img7 eV range independently of the particle species. Both the electron number and Cherenkov light density near and beyond the hump in the lateral distributions are found to accurately indicate the primary energy, provided an appropriate correction based on the depth of the shower maximum is applied. The depth of the shower maximum can be estimated from the slope of the radial distribution of the Cherenkov light. In addition, a simultaneous measurement of the muon number and Cherenkov light intensity also provides a very accurate measure of the primary energy. All of these parameters can be determined by using existing particle detector arrays. A very precise measurement of the cosmic-ray all-particle spectrum regardless of chemical composition is thus shown to be practicable.

Cortina, J.; Arqueros, F.; Lorenz, E.

1997-11-01

292

Life-cycle implications of using crop residues for various energy demands in China.  

PubMed

Crop residues are a critical component of the sustainable energy and natural resource strategy within a country. In this study, we use hybrid life-cycle environmental and economic analyses to evaluate and compare the atmospheric chemical, climatic, ecological, and economic issues associated with a set of energy conversion technologies that use crop residues for various energy demands in China. Our analysis combines conventional process-based life cycle assessment with economic input-output life cycle assessment. The results show that the return of crop residues to the fields, silo/amination and anaerobic digestion (household scale) offer the greatest ecological benefits, with net greenhouse gas reduction costs of US$3.1/tC, US$11.5/tC, and US$14.9/tC, respectively. However, if a positive net income for market-oriented operations is the overriding criterion for technology selection, the cofiring of crop residues with coal and crop residue gasification for power generation offer greater economic scope and technical feasibility, with net incomes of US$4.4/Mg and US$4.9/Mg, respectively. We identify that poor economies of scale and the absence of key technologies mean that enterprises that use pure combustion for power generation (US$212/tC), gasification for heat generation (US$366/tC) and large-scale anaerobic digestion for power generation (US$169/tC) or heat generation (US$206/tC) are all prone to operational deficits. In the near term, the Chinese government should also be cautious about any large-scale investment in bioethanol derived from crop residues because, with a carbon price of as high as US$748/tC, bioethanol is the most expensive of all energy conversion technologies in China. PMID:20426437

Lu, Wei; Zhang, Tianzhu

2010-05-15

293

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

294

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

295

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

296

Investigation of sulfur based thermochemical cycles for hydrogen production by water decomposition. [Sulfur-based cycles  

Microsoft Academic Search

Preliminary screening of ten thermochemical cycles showed that only three cycles, all based on sulfur, had > 30% efficiency. A cost analysis of these cycles, assuming a high temperature nuclear reactor as primary energy source showed a production cost of $10.83\\/million Btu in a plant of 100,000 cu m\\/hr hydrogen capacity, which would have an investment cost of $207 to

Natarajan

1976-01-01

297

PRODUCTION, ECONOMIC, AND ENERGY LIFE CYCLE ANALYSIS CAN PRODUCE CONTRARY RESULTS FOR CORN USED IN ETHANOL PRODUCTION  

Microsoft Academic Search

To prepare for a carbon (C) constrained economy, crop production energy audits or life cycle analysis (LCA) must be conducted. However, energy audits may not maximize profitability. This study conducted simultaneous production, economic, and energy audits to evaluate differences among these assessments. The 2005 and 2006 South Dakota field experiment contained two nitrogen (N; 0 and 224 kg N ha)

Francisco Mamani-Pati; David E. Clay; Gregg Carlson; Sharon A. Clay

2011-01-01

298

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

299

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

300

Variation of the flare energy spectrum during the activity cycle of the UV Cet-type stars.  

NASA Astrophysics Data System (ADS)

A study is made of the variation of the flare energy spectrum of the flare star EV Lac during the activity cycle of this star, based on the homogeneous series of observational data obtained at the Stephanion Observatory. The spectrum varies significantly during the 5 year activity cycle of this star. Analogous variation is also observed in the time-averaged rate of flare energy release of the star.

Mavridis, L. N.; Avgoloupis, S.

301

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

302

Coupling a groundwater model with a land surface model to improve water and energy cycle simulation  

NASA Astrophysics Data System (ADS)

Water and energy cycles interact, making these two processes closely related. Land surface models (LSMs) can describe the water and energy cycles on the land surface, but their description of the subsurface water processes is oversimplified, and lateral groundwater flow is ignored. Groundwater models (GWMs) describe the dynamic movement of the subsurface water well, but they cannot depict the physical mechanisms of the evapotranspiration (ET) process in detail. In this study, a coupled model of groundwater flow with a simple biosphere (GWSiB) is developed based on the full coupling of a typical land surface model (SiB2) and a three-dimensional variably saturated groundwater model (AquiferFlow). In this coupled model, the infiltration, ET and energy transfer are simulated by SiB2 using the soil moisture results from the groundwater flow model. The infiltration and ET results are applied iteratively to drive the groundwater flow model. After the coupled model is built, a sensitivity test is first performed, and the effect of the groundwater depth and the hydraulic conductivity parameters on the ET are analyzed. The coupled model is then validated using measurements from two stations located in shallow and deep groundwater depth zones. Finally, the coupled model is applied to data from the middle reaches of the Heihe River basin in the northwest of China to test the regional simulation capabilities of the model.

Tian, W.; Li, X.; Cheng, G.-D.; Wang, X.-S.; Hu, B. X.

2012-09-01

303

Coupling a groundwater model with a land surface model to improve water and energy cycle simulation  

NASA Astrophysics Data System (ADS)

Water and energy cycles interact, making these two processes closely related. Land surface models (LSMs) can describe the water and energy cycles on the land surface, but their description of the subsurface water processes is oversimplified, and lateral groundwater flow is ignored. Groundwater models (GWMs) describe the dynamic movement of the subsurface water well, but they cannot depict the physical mechanisms of the evapotranspiration (ET) process in detail. In this study, a coupled model of groundwater flow with a simple biosphere (GWSiB) is developed based on the full coupling of a typical land surface model (SiB2) and a 3-D variably saturated groundwater model (AquiferFlow). In this coupled model, the infiltration, ET and energy transfer are simulated by SiB2 using the soil moisture results from the groundwater flow model. The infiltration and ET results are applied iteratively to drive the groundwater flow model. After the coupled model is built, a sensitivity test is first performed, and the effect of the groundwater depth and the hydraulic conductivity parameters on the ET are analyzed. The coupled model is then validated using measurements from two stations located in shallow and deep groundwater depth zones. Finally, the coupled model is applied to data from the middle reach of the Heihe River basin in the northwest of China to test the regional simulation capabilities of the model.

Tian, W.; Li, X.; Cheng, G.-D.; Wang, X.-S.; Hu, B. X.

2012-12-01

304

Pyroelectric waste heat energy harvesting using relaxor ferroelectric 8/65/35 PLZT and the Olsen cycle  

NASA Astrophysics Data System (ADS)

Waste heat can be directly converted into electrical energy by performing the Olsen cycle on pyroelectric materials. The Olsen cycle consists of two isothermal and two isoelectric field processes in the electric displacement versus electric field diagram. This paper reports on the electrical energy generated by lanthanum-doped lead zirconate titanate (8/65/35 PLZT) subjected to the Olsen cycle. The material was alternately dipped into a cold and a hot silicone oil bath under specified electric fields. A maximum energy density of 888 J l-1/cycle was obtained with a 290 µm thick 8/65/35 PLZT sample for temperatures between 25 and 160?°C and electric fields cycled between 0.2 and 7.5 MV m-1. To the best of our knowledge, this is the largest pyroelectric energy density experimentally measured with multiple cycles. It corresponded to a power density of 15.8 W l-1. The electrical breakdown strength and therefore the energy and power densities of the material increased as the sample thickness was reduced from 720 to 290 µm. Furthermore, a physical model for estimating the energy harvested by ferroelectric relaxors was further validated against experimental data for a wide range of electric fields and temperatures.

Lee, Felix Y.; Goljahi, Sam; McKinley, Ian M.; Lynch, Christopher S.; Pilon, Laurent

2012-02-01

305

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

306

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

307

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

308

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

309

FasL and FADD delivery by a glioma-specific and cell cycle-dependent HSV-1 amplicon virus enhanced apoptosis in primary human brain tumors  

PubMed Central

Background Glioblastoma multiforme is the most malignant cancer of the brain and is notoriously difficult to treat due to the highly proliferative and infiltrative nature of the cells. Herein, we explored the combination treatment of pre-established human glioma xenograft using multiple therapeutic genes whereby the gene expression is regulated by both cell-type and cell cycle-dependent transcriptional regulatory mechanism conferred by recombinant HSV-1 amplicon vectors. Results We demonstrated for the first time that Ki67-positive proliferating primary human glioma cells cultured from biopsy samples were effectively induced into cell death by the dual-specific function of the pG8-FasL amplicon vectors. These vectors were relatively stable and exhibited minimal cytotoxicity in vivo. Intracranial implantation of pre-transduced glioma cells resulted in better survival outcome when compared with viral vectors inoculated one week post-implantation of tumor cells, indicating that therapeutic efficacy is dependent on the viral spread and mode of viral vectors administration. We further showed that pG8-FasL amplicon vectors are functional in the presence of commonly used treatment regimens for human brain cancer. In fact, the combined therapies of pG8-FasL and pG8-FADD in the presence of temozolomide significantly improved the survival of mice bearing intracranial high-grade gliomas. Conclusion Taken together, our results showed that the glioma-specific and cell cycle-dependent HSV-1 amplicon vector is potentially useful as an adjuvant therapy to complement the current gene therapy strategy for gliomas.

2010-01-01

310

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

PubMed

An analysis of the energy life-cycle for production of biomass using the oil-rich microalgae Nannochloropsis sp. was performed, which included both raceway ponds, tubular and flat-plate photobioreactors for algal cultivation. The net energy ratio (NER) for each process was calculated. The results showed that the use of horizontal tubular photobioreactors (PBRs) is not economically feasible ([NER]<1) and that the estimated NERs for flat-plate PBRs and raceway ponds is >1. The NER for ponds and flat-plate PBRs could be raised to significantly higher values if the lipid content of the biomass were increased to 60% dw/cwd. Although neither system is currently competitive with petroleum, the threshold oil cost at which this would occur was also estimated. PMID:19800784

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

2010-02-01

311

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

NASA Astrophysics Data System (ADS)

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

Koblinsky, C. J.

2008-05-01

312

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

313

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

PubMed

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

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

2010-01-01

314

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

315

Primary-energy dependence of the momentum transfer in reflection inner-shell-electron energy-loss spectra of layered transition-metal dichalcogenides  

Microsoft Academic Search

Sulfur L2.3 and titanium L2.3 and M2.3 inner-shell-electron energy-loss spectra in 1T-TiS2, 1T-TiSe2, 2H-TaS2, and 2H-MoS2 have been measured at various primary energies in the reflection mode. A remarkable primary-energy dependence is found. As the primary energy decreases, the first peak that is assigned to the unoccupied t2g band for the 1T compounds & band for 2H-TaS2 increases in intensity

Youichi Ohno

1987-01-01

316

Thermal energy storage for integrated gasification combined-cycle power plants  

SciTech Connect

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

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

1990-07-01

317

Calibration of a biome-biogeochemical cycles model for modeling the net primary production of teak forests through inverse modeling of remotely sensed data  

NASA Astrophysics Data System (ADS)

In this paper, we present the results of a net primary production (NPP) modeling of teak (Tectona grandis Lin F.), an important species in tropical deciduous forests. The biome-biogeochemical cycles or Biome-BGC model was calibrated to estimate net NPP through the inverse modeling approach. A genetic algorithm (GA) was linked with Biome-BGC to determine the optimal ecophysiological model parameters. The Biome-BGC was calibrated by adjusting the ecophysiological model parameters to fit the simulated LAI to the satellite LAI (SPOT-Vegetation), and the best fitness confirmed the high accuracy of generated ecophysioligical parameter from GA. The modeled NPP, using optimized parameters from GA as input data, was evaluated using daily NPP derived by the MODIS satellite and the annual field data in northern Thailand. The results showed that NPP obtained using the optimized ecophysiological parameters were more accurate than those obtained using default literature parameterization. This improvement occurred mainly because the model's optimized parameters reduced the bias by reducing systematic underestimation in the model. These Biome-BGC results can be effectively applied in teak forests in tropical areas. The study proposes a more effective method of using GA to determine ecophysiological parameters at the site level and represents a first step toward the analysis of the carbon budget of teak plantations at the regional scale.

Imvitthaya, Chomchid; Honda, Kiyoshi; Lertlum, Surat; Tangtham, Nipon

2011-01-01

318

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

319

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

320

Coupled Water, Energy, Carbon and Nutrient Cycle Dynamics in Ecohydrologic Response: Integration of Modeling with Ameriflux and FACE Observations  

Microsoft Academic Search

The terrestrial biosphere that encompasses vegetation and the adjacent soil and atmosphere, is a veritable biogeochemical crossroads, consisting of complex interactions between energy, water, carbon and nutrient transfers. Changes in one component, e.g., water, energy, carbon or nutrient cycles, has a feedback effect on all other components, with the result that the connection between cause and effect is not easily

P. Kumar; D. Drewry; M. Sivapalan; S. P. Long; X. Ling

2008-01-01

321

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

SciTech Connect

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

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

2007-04-01

322

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

323

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

NASA Astrophysics Data System (ADS)

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

Johnson, D. H.

1982-09-01

324

Nuclear energy as a primary source for a clean hydrogen energy system  

Microsoft Academic Search

The limited availability of fossil fuels compared to the increasing demand and the connected environmental questions have became topics of growing importance and international attention. Many other clean alternative sources of energy are available, but most of them are either relatively undeveloped technologically or are not yet fully utilized. Also, there is a need for a medium which can carry

M. Torjman; H. Shaaban

1998-01-01

325

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

326

Towards real energy economics: Energy policy driven by life-cycle carbon emission  

Microsoft Academic Search

Alternative energy technologies (AETs) have emerged as a solution to the challenge of simultaneously meeting rising electricity demand while reducing carbon emissions. However, as all AETs are responsible for some greenhouse gas (GHG) emissions during their construction, carbon emission “Ponzi Schemes” are currently possible, wherein an AET industry expands so quickly that the GHG emissions prevented by a given technology

R. Kenny; C. Law; J. M. Pearce

2010-01-01

327

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.

328

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

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

329

Energy storage in the primary step of the photocycle of bacteriorhodopsin.  

PubMed Central

A pulsed-dye laser low temperature photocalorimeter is used to study the enthalpy differences between light-adapted bacteriorhodopsin (bR568) and its primary photoproduct (K) at 77 K. A key feature of our experimental method is the use of the laser-induced photostationary state as an internal reference. Analyses of the forward (bR leads to K), reverse (K leads to bR), and mixed (bR in equilibrium K) photoreactions were carried out to measure delta H12 = EK - EbR. All three experiments yielded identical values of delta H12 within experimental error (delta Have12 = 15.8 +/- 2.5 kcal mol-1). Accordingly, the primary event in the photocycle of light-adapted bacteriorhodopsin stores approximately 30% of the absorbed photon energy at the 568-nm absorption maximum. We observe that the quantum yields phi f1(bR leads to K) and phi r2(K leads to bR) add up to unity within experimental error: phi f1 + phi r2 = 1.02 +/- 0.19 for phi f1 in the range 0.28-0.33. A theoretical analysis of energy storage in K suggests that at least one-half of the enthalpy difference between K and bR is associated with charge separation accompanying chromophore isomerization.

Birge, R R; Cooper, T M

1983-01-01

330

Comparative thermodynamic performance of some Rankine/Brayton cycle configurations for a low-temperature energy application  

NASA Technical Reports Server (NTRS)

Various configurations combining solar-Rankine and fuel-Brayton cycles were analyzed in order to find the arrangement which has the highest thermal efficiency and the smallest fuel share. A numerical example is given to evaluate both the thermodynamic performance and the economic feasibility of each configuration. The solar-assisted regenerative Rankine cycle was found to be leading the candidates from both points of energy utilization and fuel conservation.

Lansing, F. L.

1977-01-01

331

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

332

LIFE CYCLE DESIGN OF AMORPHOUS SILICON PHOTOVOLTAIC MODULES  

EPA Science Inventory

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

333

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

Microsoft Academic Search

EXECUTIVE SUMMARY ;\\u000a\\u0009The benefits of wind energy had previously been captured in the literature at an overview level with relatively low transparency or ability to understand the basis for that information. This has limited improvement and decision-making to larger questions such as wind versus other electrical sources (such as coal-fired plants). This research project has established a substantially different

Janet M Twomey

2010-01-01

334

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

NASA Astrophysics Data System (ADS)

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

Golshani, A.; Chen, F. C.

1983-01-01

335

Thermal analysis in a solar pumped laser for Mg energy cycle  

NASA Astrophysics Data System (ADS)

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

Bagheri, Behgol; Uchidat, Shgeaki

2012-10-01

336

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

SciTech Connect

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

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

2011-09-15

337

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

338

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

PubMed

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

Kim, Seungdo; Dale, Bruce E

2008-10-15

339

Battery cycle life balancing in a microgrid through flexible distribution of energy and storage resources  

NASA Astrophysics Data System (ADS)

In this paper, a microgrid consisting of four fuel cell-battery hybrid Distributed Energy Resources (DERs) is devised for an industrial crusher-conveyor load. Each fuel cell was accompanied by a Li-ion battery to provide energy storage support under islanded condition of the microgrid since the fuel cells typically have poor transient response characteristics. After carrying out extensive modeling and analysis in MATLAB®, the battery utilization was found to vary significantly based on the DER's ‘electrical’ placement within the microgrid. This paper presents, under such conditions, a variety of battery life balancing solutions through the use of the new framework of Flexible Distribution of EneRgy and Storage Resources (FDERS). It is based on an in-situ reconfiguration approach through ‘virtual’ reactances that help in changing the ‘electrical’ position of each DER without physically displacing any component in the system. Several possible approaches toward balancing the battery utilization are compared in this paper taking advantage of the flexibility that FDERS offers. It was observed that the estimated battery life is dependent on factors such as cycling sequence, pattern, and occurrence.

Khasawneh, Hussam J.; Illindala, Mahesh S.

2014-09-01

340

Prognostic significance of regulators of cell cycle and apoptosis, p16(INK4a), p53, and bcl-2 in primary mucosal melanomas of the head and neck.  

PubMed

Abnormalities in cell cycle regulation, tumor suppressor gene functions and apoptosis are frequent events in tumorigenesis. Their role in the pathogenesis and prognosis of primary mucosal melanomas (MM) of the upper aerodigestive tract remains unknown. Sixty-four patients (40 men, 24 women, median age 64 years) with MM were included in this study; 32 had tumors in the nasal/paranasal cavities, 28 in the oral cavity and 4 in the pharynx. Archival tissues from 47 initial mucosal tumors, 17 mucosal recurrences, and 13 nodal/distant metastases were subjected to immunohistochemistry using antibodies against p16, p53, and bcl-2. The results were correlated with histological features and survival data. Expressions of p16, p53, and bcl-2 proteins were seen in 25% (N=19/76), 21% (N=16/76), and 74% (N=56/76) of all tumors, respectively. bcl-2 expression in the initial tumors was associated with significantly longer overall and disease specific survival (3.3 vs. 1.5 years, P ? 0.05). Expression of p16 was increasingly lost, from 32% in initial tumors to 12% in recurrent and 15% in metastatic tumors (P=0.06). Tumors comprised of undifferentiated cells were significantly more p53 positive than epithelioid or spindle cells (80% vs. 33%, P=0.02). Expression of these markers did not correlate with necrosis, or vascular and/or deep tissue invasion. Expression of bcl-2 is associated with better survival in MM. Loss of p16 was seen with tumor progression whereas aberrant p53 expression was frequent in undifferentiated tumor cells. PMID:22160615

Prasad, Manju L; Patel, Snehal G; Shah, Jatin P; Hoshaw-Woodard, Stacy; Busam, Klaus J

2012-06-01

341

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

342

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

PubMed Central

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

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

2012-01-01

343

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

344

Measurement of changes in high-energy phosphates in the cardiac cycle using gated 31P nuclear magnetic renonance.  

PubMed Central

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

Fossel, E T; Morgan, H E; Ingwall, J S

1980-01-01

345

Dual energy micro-CT imaging of radiation-induced vascular changes in primary mouse sarcomas  

PubMed Central

Purpose To evaluate the effects of radiation therapy on primary tumor vasculature using dual energy (DE) micro-computed tomography (micro-CT). Methods and Materials The Cre-loxP system was used to generate primary sarcomas with mutant Kras and p53. Unirradiated tumors were compared to tumors irradiated with 20 Gy. A long-circulating PEGylated liposomal-iodinated contrast agent was administered one day after treatment, and mice were imaged immediately after injection (day 1) and three days later (day 4) using DE micro-CT. CT-derived tumor sizes were used to assess tumor growth. After DE decomposition, iodine maps were used to assess tumor fractional blood volume (FBV) at day 1 and tumor vascular permeability at day 4. For comparison, tumor vascularity and vascular permeability were also evaluated histologically using CD31 immunofluorescence and fluorescently-labeled dextrans. Results Radiation treatment significantly decreased tumor growth (P<0.05). There was a positive correlation between CT-measurement of tumor FBV and extravasated iodine with microvascular density (MVD) (R2=0.53) and dextran accumulation (R2=0.63), respectively. Despite no change in MVD measured by histology, tumor FBV significantly increased after irradiation as measured by DE micro-CT (0.070 vs. 0.091, P<0.05). Both dextran and liposomal-iodine accumulation in tumors increased significantly after irradiation with dextran fractional area increasing 4.2-fold and liposomal-iodine concentration increasing 3.0-fold. Conclusions DE micro-CT is an effective tool for non-invasive assessment of vascular changes in primary tumors. Tumor blood volume and vascular permeability increased after a single therapeutic dose of radiation treatment.

Moding, Everett J.; Clark, Darin P.; Qi, Yi; Li, Yifan; Ma, Yan; Ghaghada, Ketan; Johnson, G. Allan; Kirsch, David G.; Badea, Cristian T.

2013-01-01

346

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

347

On the primary energy distribution and the EBL limits from TeV Blazars  

NASA Astrophysics Data System (ADS)

Knowledge of the acceleration of charged particles in astrophysical shock waves and their consequent emission is crucial on testing the astroparticle physical conditions occurring in environments such as Blazars. In the present work, we discuss how the variation of the primary energy spectral index of accelerated electrons, which may occur in mild or extreme relativistic shocks of Blazars, may consequently affect the limits of the extragalactic absorption models. While in the past the electron spectrum was traditionally assumed to follow an E-2 spectrum below the cooling break energy, our and other recent models of diffusive acceleration result in energy spectra with varying spectral indexes such as E-1.0 up to E-2.5, which pose critical physical constraints. In this work, we re-examine the limit on the extragalactic background light (EBL) set by the H.E.S.S. While the latter assumed that electron spectra cannot be flatter than dN/dE~E-1.5, here we give a relaxed limit on the EBL by allowing for spectra as flat as E-1.0 corresponding to more specific shock parameters, in contrast to previous works.

Meli, A.; Kneiske, T.; Becker, J. K.

2008-12-01

348

Planning for hybrid-cycle OTEC (Ocean Thermal Energy Conservation) experiments using the HMTSTA test facility at the Natural Energy Laboratory of Hawaii.  

National Technical Information Service (NTIS)

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-...

C. Panchal T. Rabas L. Genens

1989-01-01

349

Organic Rankine cycle/heat pump technology working fluid problems  

SciTech Connect

This book contains papers that consider various options for improving the utilization of primary energy. The papers focus on improving the classical steam cycle by a bottoming-cycle that uses a working fluid different from steam. Also discussed are methods of improving waste heat utilization, especially by employing low temperature power cycles to generate shaft power or electricity by using heat pumps to boost waste heat temperature.

Baehr, H.D.

1984-01-01

350

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

351

Energy deposition and primary chemical products in Titan’s upper atmosphere  

NASA Astrophysics Data System (ADS)

Cassini results indicate that solar photons dominate energy deposition in Titan's upper atmosphere. These dissociate and ionize nitrogen and methane and drive the subsequent complex organic chemistry. The improved constraints on the atmospheric composition from Cassini measurements demand greater precision in the photochemical modeling. Therefore, in order to quantify the role of solar radiation in the primary chemical production, we have performed detailed calculations for the energy deposition of photons and photoelectrons in the atmosphere of Titan and we validate our results with the Cassini measurements for the electron fluxes and the EUV/FUV emissions. We use high-resolution cross sections for the neutral photodissociation of N 2, which we present here, and show that they provide a different picture of energy deposition compared to results based on low-resolution cross sections. Furthermore, we introduce a simple model for the energy degradation of photoelectrons based on the local deposition approximation and show that our results are in agreement with detailed calculations including transport, in the altitude region below 1200 km, where the effects of transport are negligible. Our calculated, daytime, electron fluxes are in good agreement with the measured fluxes by the Cassini Plasma Spectrometer (CAPS), and the same holds for the measured FUV emissions by the Ultraviolet Imaging Spectrometer (UVIS). Finally, we present the vertical production profiles of radicals and ions originating from the interaction of photons and electrons with the main components of Titan's atmosphere, along with the column integrated production rates at different solar zenith angles. These can be used as basis for any further photochemical calculations.

Lavvas, P.; Galand, M.; Yelle, R. V.; Heays, A. N.; Lewis, B. R.; Lewis, G. R.; Coates, A. J.

2011-05-01

352

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

PubMed Central

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

Anemaet, Ida G.; Bekker, Martijn

2010-01-01

353

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

PubMed

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

Anemaet, Ida G; Bekker, Martijn; Hellingwerf, Klaas J

2010-11-01

354

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

355

Energy and environmental analysis of an innovative system based on municipal solid waste (MSW) pyrolysis and combined cycle  

Microsoft Academic Search

This paper presents the energy and the environmental impact analysis of an innovative system based on the pyrolysis of MSW which produces solid (char), liquid (tar) and gas (syngas) fuels used in a combined cycle for electric power generation. The syngas, after filtration and compression, feeds two gas turbines. In turn, the exhaust from the gas turbines, after post-combustion with

Paolo Baggio; Marco Baratieri; Andrea Gasparella; Giovanni A. Longo

2008-01-01

356

Modeling energy flow and nutrient cycling in natural semiarid grassland ecosystems with the aid of thematic mapper data  

NASA Technical Reports Server (NTRS)

Energy flow and nutrient cycling were modeled as affected by herbivory on selected intensive sites along gradients of precipitation and soils, validating the model output by monitoring selected parameters with data derived from the Thematic Mapper (TM). Herbivore production was modeled along the gradient of soils and herbivory, and validated with data derived from TM in a spatial data base.

Lewis, James K.

1987-01-01

357

Degradation of sea urchin feces in a rocky subtidal ecosystem: implications for nutrient cycling and energy flow  

Microsoft Academic Search

During destructive grazing events in the Northwest Atlantic, sea urchins Strongylocen- trotus droebachiensis consume large amounts of kelp biomass, transforming this material into feces. To determine the role of urchin fecal material in nutrient cycling and energy flow in the shallow rocky subtidal zone, we monitored the physical, chemical, and microbial degradation of urchin feces at 6, 9, 12, and

Leah K. Sauchyn; Robert E. Scheibling

2009-01-01

358

High-energy, high-repetition rate, few-cycle and CEP-stable mid-IR OPCPA  

NASA Astrophysics Data System (ADS)

An OPCPA delivering optical pulses with 20 ?J energy at 160 kHz repetition rate at 3.1 ?m central wavelength is reported. The pulse duration was measured to be 6 cycles and a CEP stability of 250 mrad over 10 minutes has been measured.

Hemmer, Michaël; Thai, Alexandre; Baudisch, Matthias; Biegert, Jens

2012-07-01

359

Transport, Housing and Urban Form: The Life Cycle Energy Consumption and Emissions of City Centre Apartments Compared with Suburban Dwellings  

Microsoft Academic Search

Buildings in cities and the activities carried out therein use a significant proportion of a nation's energy consumption and produce substantial quantities of greenhouse gases in the process. Residential buildings are a large contributor, partially as a result of the transport and housing activities of households. In this study, life cycle analysis is used to calculate the total transport and

Alan Perkins; Steve Hamnett; Stephen Pullen; Rocco Zito; David Trebilcock

2009-01-01

360

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

Microsoft Academic Search

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

L. Reijnders; M. A. J. Huijbregts

2007-01-01

361

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

362

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

Microsoft Academic Search

Algae cofiring scenarios in a 360 MW coal power plant were studied utilizing an ecologically based hybrid life cycle assessment methodology. The impacts on the ecological system were calculated in terms of cumulative mass, energy, industrial exergy, and ecological exergy. The environmental performance metrics, including efficiency, loading, and renewability ratios were also quantified to assess the sustainability of cofiring scenarios from

Murat Kucukvar; Omer Tatari

2011-01-01

363

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

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

364

A high-rate and long cycle life aqueous electrolyte battery for grid-scale energy storage.  

PubMed

New types of energy storage are needed in conjunction with the deployment of solar, wind and other volatile renewable energy sources and their integration with the electric grid. No existing energy storage technology can economically provide the power, cycle life and energy efficiency needed to respond to the costly short-term transients that arise from renewables and other aspects of grid operation. Here we demonstrate a new type of safe, fast, inexpensive, long-life aqueous electrolyte battery, which relies on the insertion of potassium ions into a copper hexacyanoferrate cathode and a novel activated carbon/polypyrrole hybrid anode. The cathode reacts rapidly with very little hysteresis. The hybrid anode uses an electrochemically active additive to tune its potential. This high-rate, high-efficiency cell has a 95% round-trip energy efficiency when cycled at a 5C rate, and a 79% energy efficiency at 50C. It also has zero-capacity loss after 1,000 deep-discharge cycles. PMID:23093186

Pasta, Mauro; Wessells, Colin D; Huggins, Robert A; Cui, Yi

2012-01-01

365

Energy balance of the closed oxygen cycle and processes causing thermal runaway in valve-regulated lead/acid batteries  

NASA Astrophysics Data System (ADS)

A model for the reactions involved in the closed oxygen cycle in valve-regulated lead/acid batteries and the associated energy transformations is proposed. When electric current flows through the closed oxygen cycle, a certain amount of electric energy is converted via electrochemical processes into chemical energy, i.e. the products obtained may interact spontaneously as a result of which the system returns to its initial state. During these spontaneous reactions, the chemical energy is converted into heat. Depending on the type of the reactions involved in oxygen reduction on the negative plate, the closed oxygen cycle may proceed in two different electrochemical systems: (i) oxygen is reduced through electrochemical reactions yielding the electrochemical system PbO 2//H 2OO/O 2///O 2//H 2OO/Pb, and (ii) oxygen is reduced through chemical reactions forming the electrochemical system PbO 2//H 2OO/O 2///PbSO 4//Pb. The energy introduced into the system for activation of the closed oxygen cycle is different for the two electrochemical systems. The quantity of this energy is calculated in the present work using thermodynamic data. During the closed oxygen cycle the electric energy is transformed into chemical energy which, in turn, is converted into heat. Part of this heat causes the cell temperature to increase and another part dissipates into the surrounding air. The amount of the former heat depends on the heat capacity of the battery and is influenced most strongly by the quantity of the electrolyte. It has been established that the rate of oxygen evolution on the positive plate depends strongly on the temperature. When the heat exchange between the battery and the surrounding medium is poor, the reactions of the closed oxygen cycle may enter (through the heat and oxygen flows between the positive and the negative plates) into self-accelerating interrelations, which may lead to thermal runaway. To avoid this, an adequate heat exchange should be maintained between the battery and the surrounding medium, the rate of the oxygen reaction should be kept down and a high heat capacity of the battery and small water loss on its operation should be ensured.

Pavlov, D.

366

Comparison of life cycle emissions and energy consumption for environmentally adapted metalworking fluid systems.  

PubMed

A number of environmentally adapted lubricants have been proposed in response to the environmental and health impacts of metalworking fluids (MWFs). The alternatives typically substitute petroleum with vegetable-based components and/or deliver minimum quantities of lubricant in gas rather than water, with the former strategy being more prevalent than the latter. A comparative life cycle assessment of water- and gas-based systems has shown that delivery of lubricants in air rather than water can reduce solid waste by 60%, water use by 90%, and aquatic toxicity by 80%, while virtually eliminating occupational health concerns. However, air-delivery of lubricants cannot be used for severe machining operations due to limitations of cooling and lubricant delivery. For such operations, lubricants delivered in supercritical carbon dioxide (scCO2) are effective while maintaining the health and environmental advantages of air-based systems. Although delivery conditions were found to significantly influence the environmental burdens of all fluids, energy consumption was relatively constant under expected operating conditions. Global warming potential (GWP) increased when delivering lubricants in gas rather than water though all classes of MWFs have low GWP compared with other factory operations. It is therefore concluded that the possibility of increased GWP when switching to gas-based MWFs is a reasonable tradeoff for definite and large reductions in aquatic toxicity, water use, solid waste, and occupational health risks. PMID:19068844

Clarens, Andres F; Zimmerman, Julie B; Keoleian, Greg A; Hayes, Kim F; Skerlos, Steven J

2008-11-15

367

A New Measurement on the Energy Spectrum of Primary Cosmic Rays in the Energy Region 1014-1016eV, with GRAPES-3 Experiment  

NASA Astrophysics Data System (ADS)

The GRAPES-3 extensive air shower (EAS) array consists of 256 densely packed unshielded `electron' detectors with inter-detector spacing of only 8 m. The array configuration is hexagonally symmetric. Showers collected during the period, 2000-2002, with a simple trigger requiring only a 3-fold coincidence between signals from detectors from 3 nearby rows, have been analysed for various shower parameters. A shower size spectrum has been constructed using this large data base over the shower size range, 105 -107 . The spectral steep ening is clearly seen at shower size ˜6×105 particles corresponding to primary energy ˜3×1015 eV. Results from detailed Monte Carlo simulations have been used to convert the observed size spectrum to primary cosmic ray energy spectrum. We present here details of the experiment, analysis procedure and the energy spectrum for various assumed models for primary composition at energies ˜1015 eV.

Gupta, S. K.; Hayashi, Y.; Ishida, Y.; Ito, N.; Jain, Atul; John, A.V.; Kawakami, S.; Kojima, H.; Matasuyama, T.; Mohanty, D.K.; Mohanty, P.K.; Morris, S.D.; Nonaka, T.; Oshima, A.; Ravindran, K.C.; Sasano, M.; Sivaprasad, K.; Sreekantan, B.V.; Tamaki, S.; Tanaka, H.; Tonwar, S.C.; Viswanathan, K.; Yoshikoshi, T.

2003-07-01

368

Recent climate changes over the Tibetan Plateau and their impacts on energy and water cycle: A review  

NASA Astrophysics Data System (ADS)

The Tibetan Plateau (TP) exerts strong thermal forcing on the atmosphere over Asian monsoon region and supplies water resources to adjacent river basins. Recently, the Plateau experienced evident climate changes, which have changed atmospheric and hydrological cycles and thus reshaped the local environment. This study reviewed recent research progress in the climate changes and explored their impacts on the Plateau energy and water cycle, based on which a conceptual model to synthesize these changes was proposed and urgent issues to be explored were summarized.

Yang, Kun; Wu, Hui; Qin, Jun; Lin, Changgui; Tang, Wenjun; Chen, Yingying

2014-01-01

369

Cycle life tester for the long-term stability of phase change materials for thermal energy storage  

SciTech Connect

The choice of a phase change material (PCM) for a particular application of storage of low potential thermal solar energy depends upon several considerations, one of the more important being its long-term stability in repeated freeze-thaw cycles. An experimental apparatus has been constructed to simulate, on a greatly speeded-up scale, several years' use of macroscopic quantities of a PCM. The thermal behavior of the substance is monitored by a microcomputer, which also controls the freeze-thaw cycles. 15 refs.

Grandbois, A.; Sangster, J.; Paris, J.R.

1981-01-01

370

Flow rate and duty cycle effects in lysis of Chlamydomonas reinhardtii using high-energy pulsed focused ultrasound.  

PubMed

To consider microalgae lipid biofuel as a viable energy source, it is a necessity to maximize algal cell lysis, lipid harvest, and thus biofuel production versus the energy used to lyse the cells. Previous techniques have been to use energy consumptive ultrasound waves in the 10-40?kHz range in a stationary exposure environment. This study evaluated the potential of using 1.1?MHz ultrasound pulses in a new flow through type chamber on Chlamydomonas reinhardtii as a model organism for cell breakage. The ultrasound was generated using a spherically focused transducer with a focal length of 6.34?cm and an active diameter of 6.36?cm driven by 20 cycle sine-wave tone bursts at varied pulse repetition frequencies. First, variations in flow rate were examined at a constant duty cycle of 3.6%. After assessing flow rates, the duty cycle was varied to further explore the dependence on the tone burst parameters. Cell lysis was assessed by quantifying protein and chlorophyll release into the supernatant as well as by lipid extractability. Appropriate flow rates with higher duty cycles led to statistically significant increases in cell lysis relative to controls and other exposure conditions. PMID:24916410

Riesberg, Grant; Bigelow, Timothy A; Stessman, Dan J; Spalding, Martin H; Yao, Linxing; Wang, Tong; Xu, Jin

2014-06-01

371

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

NASA Astrophysics Data System (ADS)

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

Smith, Amanda D.

372

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

373

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

Microsoft Academic Search

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 COâ 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

W. M. Post; V. H. Dale; D. L. DeAngelis; L. K. Mann; P. J. Mulholland; R. V. ONeill; T.-H. Peng; M. P. Farrell

1990-01-01

374

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

375

Energy distribution in white organic light-emitting diodes with three primary color emitting layers  

NASA Astrophysics Data System (ADS)

Two types of organic light-emitting diodes with structures of ITO/ N, N'-bis(1-naphthyl)- N, N'-diphenyl,1,1'-biphenyl-4,4'-diamine (NPB)/tris(8-hydroquinolinato)aluminum(Alq3)/2,9-dimethyl-4,7-diphenyl-l,10-phenanthroline(BCP)/Alq3:4-dicyanome-thylene-2-(tert-butyl)-6-methyl-4H-pyran(DCJTB)/Alq3/Al and ITO/NPB/BCP/Alq3/Alq3:DCJTB/Alq3/Al were studied. NPB was chosen as a hole-transporting/blue-emitting layer. Alq3 adjacent to BCP acted as a green emitting layer while that adjacent to the Al cathode acted as an electron-transporting layer. Alq3 doped with 2 wt.% DCJTB was used as a red emitting layer. The operating principles of the devices were explained by the mechanism of Förster energy transfer and the hole and exciton blocking effect of BCP. It was found that the spectral characteristics of the devices strongly depended on the relative location between the green emitting Alq3 layer and the BCP layer, as well as their thickness. Pure white emission with the CIE coordinates of (0.33, 0.33) was achieved by mixing the three primary colors in the device with the structure of ITO/NPB(30 nm)/ BCP(6 nm)/Alq3(30 nm)/Alq3:DCJTB(30 nm)/Alq3(30 nm)/Al. The BCP layer played an important role in distributing the exciton energy among the three emitting layers to achieve a balanced white light. The white emission of this device was largely insensitive to the driving voltage (15-27 V) with the insertion of the green emitting Alq3 layer.

Meng, LingChuan; Lou, ZhiDong; Yang, ShengYi; Deng, ZhaoRu

2011-01-01

376

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

SciTech Connect

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

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

1992-01-01

377

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

Microsoft Academic Search

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

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

2011-01-01

378

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

379

Pipe break testing of primary loop piping similar to Department of Energy's New Production Reactor-Heavy Water Reactor.  

National Technical Information Service (NTIS)

Oak Ridge National Laboratory is completing a major task for the Department of Energy in the demonstration that the primary piping of the New Production Heavy Water Reactor (NPR-HWR), with its relatively moderate temperature and pressure, should not suffe...

A. B. Poole R. L. Battiste J. A. Clinard W. R. Hendrich

1992-01-01

380

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

Microsoft Academic Search

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

H. MOORA; V LAHTVEE

2009-01-01

381

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

382

Sensitivity of the mesosphere to the Lorenz energy cycle of the troposphere  

NASA Astrophysics Data System (ADS)

The sensitivity of the mesosphere and lower thermosphere (MLT) to climate variability in the troposphere is largely controlled by the generation, propagation, and dissipation of gravity waves (GWs). Conventional climate models cannot fully describe this sensitivity since GWs must be parameterized by invoking strong assumptions. In particular, a fixed GW source at a single level in the troposphere is often assumed. Since the Eliassen-Palm flux (EPF) of low-frequency inertia GWs tends to vanish, the main contribution to the EPF divergence at high latitudes of the MLT is due to midand high-frequency GWs with periods of a few hours or less. In order to resolve at least a good portion of these waves in a GCM, a high spatial resolution from the boundary layer to the lower thermosphere is required. Furthermore, both the generation and dissipation of resolved GWs is expected to depend strongly on the details of the parameterization of turbulence. The present study proposes a new formulation of a mechanistic GCM with high spatial resolution and a sophisticated parameterization of turbulence. This model explicitly simulates the wave drag of the MLT that results from the dynamical GW sources in the troposphere. The Smagorinsky-type horizontal and vertical diffusion coefficients are scaled by the Richardson criterion such that no sponge layer is required for the GWs to dissipate in the MLT. A sensitivity experiment shows that a reduced static stability in the lower troposphere, which may be associated with climate change, leads to a stronger Lorenz energy cycle. The intensification of the tropospheric heat engine is accompanied by enhanced GW acitivity in the upper troposphere at middle latitudes. These changes induce the following remote effects in the summer MLT: downshift of the residual circulation, as well as stronger dissipation, lower temperatures, and reduced easterlies below the mesopause. The simulated sensitivity is consistent with enhanced turbulent diffusion at lower altitudes resulting from stronger GW amplitudes.

Becker, Erich

383

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

PubMed

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

2013-11-01

384

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.

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

385

The University of Minnesota aquifer thermal energy storage (ATES) field test facility -- system description, aquifer characterization, and results of short-term test cycles  

SciTech Connect

Phase 1 of the Aquifer Thermal Energy Storage (ATES) Project at the University of Minnesota was to test the feasibility, and model, the ATES concept at temperatures above 100{degrees}C using a confined aquifer for the storage and recovery of hot water. Phase 1 included design, construction, and operation of a 5-MW thermal input/output field test facility (FTF) for four short-term ATES cycles (8 days each of heat injection, storage, and heat recover). Phase 1 was conducted from May 1980 to December 1983. This report describes the FTF, the Franconia-Ironton-Galesville (FIG) aquifer used for the test, and the four short-term ATES cycles. Heat recovery; operational experience; and thermal, chemical, hydrologic, and geologic effects are all included. The FTF consists of monitoring wells and the source and storage well doublet completed in the FIG aquifer with heat exchangers and a fixed-bed precipitator between the wells of the doublet. The FIG aquifer is highly layered and a really anisotropic. The upper Franconia and Ironton-Galesville parts of the aquifer, those parts screened, have hydraulic conductivities of {approximately}0.6 and {approximately}1.0 m/d, respectively. Primary ions in the ambient ground water are calcium and magnesium bicarbonate. Ambient temperature FIG ground water is saturated with respect to calcium/magnesium bicarbonate. Heating the ground water caused most of the dissolved calcium to precipitate out as calcium carbonate in the heat exchanger and precipitator. Silica, calcium, and magnesium were significantly higher in recovered water than in injected water, suggesting dissolution of some constituents of the aquifer during the cycles. Further work on the ground water chemistry is required to understand water-rock interactions.

Walton, M.; Hoyer, M.C.; Eisenreich, S.J.; Holm, N.L.; Holm, T.R.; Kanivetsky, R.; Jirsa, M.A.; Lee, H.C.; Lauer, J.L.; Miller, R.T.; Norton, J.L.; Runke, H. (Minnesota Geological Survey, St. Paul, MN (United States))

1991-06-01

386

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

387

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

388

Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 9: Closed-cycle MHD  

Microsoft Academic Search

A closed-cycle MHD system for an electric power plant was studied. It consists of 3 interlocking loops, an external heating loop, a closed-cycle cesium seeded argon nonequilibrium ionization MHD loop, and a steam bottomer. A MHD duct maximum temperature of 2366 K (3800 F), a pressure of 0.939 MPa (9.27 atm) and a Mach number of 0.9 are found to

T. C. Tsu

1976-01-01

389

Energy Conversion Alternatives Study (ECAS), Westinghouse Phase 1. Vol. VIIII: closed-cycle MHD. Final report  

Microsoft Academic Search

A closed-cycle MHD system for an electric power plant was studied. It consists of 3 interlocking loops, an external heating loop, a closed-cycle cesium seeded argon nonequilibrium ionization MHD loop, and a steam bottomer. A MHD duct maximum temperature of 2366 K (3800 F), a pressure of 0.939 MPa (9.27 atm) and a Mach number of 0.9 are found to

Tsu

1976-01-01

390

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

Microsoft Academic Search

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

Balsara; Nitash

2010-01-01

391

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

Microsoft Academic Search

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

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

2007-01-01

392

Surface energy, water and carbon cycle in China simulated by the Australian community land surface model (CABLE)  

Microsoft Academic Search

Through an Australia-China climate change bilateral project, we analyzed results of 51-year global offline simulations over\\u000a China using the Australian community atmosphere biosphere land exchange (CABLE) model, focusing on integrated studies of its\\u000a surface energy, water and carbon cycle at seasonal, interannual and longer time-scales. In addition to the similar features\\u000a in surface climatology between the CABLE simulation and those

Liang Zhang; Huqiang Zhang; Yaohui Li

2009-01-01

393

Effects of low and high levels of moderate hypoxia on anaerobic energy release during supramaximal cycle exercise  

Microsoft Academic Search

The purpose of this study was to investigate whether hypoxia can alter anaerobic energy release during supramaximal exercise. Seven male subjects performed 12 submaximal cycling tests to establish the relationship between workload and O2 demand. The subjects also performed 40 s Wingate tests (WT) under normoxia (room air), two levels of moderate hypoxia of 16.4% O2 and 12.7% O2. We measured

Yuji Ogura; Shizuo Katamoto; Jin Uchimaru; Kohei Takahashi; Hisashi Naito

2006-01-01

394

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

395

Coupled energy-balance\\/ice-sheet model simulations of the glacial cycle: A possible connection between terminations and terrigenous dust  

Microsoft Academic Search

We apply a coupled energy-balance\\/ice-sheet climate model in an investigation of northern hemisphere ice-sheet advance and retreat over the last glacial cycle. When driven only by orbital insolation variations, the model predicts ice-sheet advances over the continents of North America and Eurasia that are in good agreement with geological reconstructions in terms of the timescale of advance and the spatial

W. Richard Peltier; Shawn Marshall

1995-01-01

396

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

Microsoft Academic Search

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

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

2011-01-01

397

Biogeochemical cycling of carbon, water, energy, trace gases, and aerosols in Amazonia: The LBA-EUSTACH experiments  

Microsoft Academic Search

The biogeochemical cycling of carbon, water, energy, aerosols, and trace gases in the Amazon Basin was investigated in the project European Studies on Trace Gases and Atmospheric Chemistry as a Contribution to the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA-EUSTACH). We present an overview of the design of the project, the measurement sites and methods, and the meteorological conditions during the

M. O. Andreae; P. Artaxo; C. Brandão; F. E. Carswell; P. Ciccioli; A. L. da Costa; A. D. Culf; J. L. Esteves; J. H. C. Gash; J. Grace; P. Kabat; J. Lelieveld; Y. Malhi; A. O. Manzi; F. X. Meixner; A. D. Nobre; C. Nobre; M. d. L. P. Ruivo; M. A. Silva-Dias; P. Stefani; R. Valentini; J. von Jouanne; M. J. Waterloo

2002-01-01

398

Primary-energy dependence of the momentum transfer in reflection inner-shell-electron energy-loss spectra of layered transition-metal dichalcogenides  

NASA Astrophysics Data System (ADS)

Sulfur L2.3 and titanium L2.3 and M2.3 inner-shell-electron energy-loss spectra in 1T-TiS2, 1T-TiSe2, 2H-TaS2, and 2H-MoS2 have been measured at various primary energies in the reflection mode. A remarkable primary-energy dependence is found. As the primary energy decreases, the first peak that is assigned to the unoccupied t2g band for the 1T compounds & band for 2H-TaS2 increases in intensity relative to the second peak. The peak positions are almost unchanged. They are in agreement with those of band-structure calculations and x-ray absorption spectra. The primary-energy dependence has been discussed mainly in terms of the breakdown of dipole selection rules due to momentum transfer involved in the inelastic scattering process and anisotropy in electronic structures.

Ohno, Youichi

1987-11-01

399

Simulations of Water and Energy Cycles over the Congo and Upper Blue Nile basins by IPCC GCMs  

NASA Astrophysics Data System (ADS)

The simulations of the hydrological cycle in general circulation models (GCMs) are characterized by a significant degree of uncertainty. This uncertainty is reflected in the wide range of IPCC (Intergovernmental Panel on Climate Change) GCMs predictions of future changes in the hydrological cycle, particularly over major African basins. Here, we explore the relations between the surface radiation and hydrological cycle within 17 of the IPCC GCMs over the Congo and Upper Blue Nile (UBN) basins. Most GCMs overestimate the hydrological cycle over the basins compared to observations. This overestimation is associated with excess net surface radiation, attributed to an overestimation of downward shortwave radiation and an underestimation of upward longwave radiation at the surface compared to observations. In order to verify if the overestimation of the net radiation is a systematic problem in these models for other regions, the net surface radiation over the Sahara Desert is also investigated. Although the Sahara Desert has a different climatic conditions compared to the studied basins, but the persistent overestimation of the net surface radiation for all models over this region suggests that models tend to overestimate the net surface radiation at least over the majority of the African continent. Our results also show that the increase in horizontal resolution of GCMs results in a better simulations of the hydrological cycle. In addition, the absence of the radiation effects of mineral aerosols, biomass burning and low negative cloud feedback for most of the models can be responsible of the overestimation of both the energy and hydrological cycles over the studied regions.

Eltahir, E. A.; Siam, M.

2012-12-01

400

miR-221/222 Compensates for Skp2-Mediated p27 Degradation and Is a Primary Target of Cell Cycle Regulation by Prostacyclin and cAMP  

PubMed Central

p27kip1 (p27) is a cdk-inhibitory protein with an important role in the proliferation of many cell types. SCFSkp2 is the best studied regulator of p27 levels, but Skp2-mediated p27 degradation is not essential in vivo or in vitro. The molecular pathway that compensates for loss of Skp2-mediated p27 degradation has remained elusive. Here, we combine vascular injury in the mouse with genome-wide profiling to search for regulators of p27 during cell cycling in vivo. This approach, confirmed by RT-qPCR and mechanistic analysis in primary cells, identified miR-221/222 as a compensatory regulator of p27. The expression of miR221/222 is sensitive to proteasome inhibition with MG132 suggesting a link between p27 regulation by miRs and the proteasome. We then examined the roles of miR-221/222 and Skp2 in cell cycle inhibition by prostacyclin (PGI2), a potent cell cycle inhibitor acting through p27. PGI2 inhibited both Skp2 and miR221/222 expression, but epistasis, ectopic expression, and time course experiments showed that miR-221/222, rather than Skp2, was the primary target of PGI2. PGI2 activates Gs to increase cAMP, and increasing intracellular cAMP phenocopies the effect of PGI2 on p27, miR-221/222, and mitogenesis. We conclude that miR-221/222 compensates for loss of Skp2-mediated p27 degradation during cell cycling, contributes to proteasome-dependent G1 phase regulation of p27, and accounts for the anti-mitogenic effect of cAMP during growth inhibition.

Hawthorne, Elizabeth A.; Liu, Shu-Lin; Xu, Tina; Rao, Shilpa; Yung, Yuval; Assoian, Richard K.

2013-01-01

401

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 8.37MJ/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

402

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

PubMed

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

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

2013-10-01

403

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

SciTech Connect

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

Porter, R.W.

1982-12-01

404

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

405

Utilization of Industrial Waste Heat, Citing an Integrated Iron and Steel Works as an Example to Save Primary Energy and to Reduce the Burden on the Environment, Volume 1.  

National Technical Information Service (NTIS)

The utilization of waste heat to substitute primary energy is an essential factor to complement the savings of primary energy achieved by changes in the design of industrial plant and processes. The potential for waste energy utilization in an integrated ...

H. G. Poettken H. Strohschein

1982-01-01

406

Utilization of Industrial Waste Heat, Citing an Integrated Iron and Steel Works as an Example to Save Primary Energy and to Reduce the Burden on the Environment, Volume 2.  

National Technical Information Service (NTIS)

The potential of waste energy utilization in an integrated iron and steel works were investigated in technical and economic terms. The utilization of wste heat to substitute primary energy is an essential factor to complement the savings of primary energy...

H. G. Poettken H. Strohschein

1982-01-01

407

Thermochemical cycles  

NASA Technical Reports Server (NTRS)

The thermochemical production of hydrogen is described along with the HYDRGN computer program which attempts to rate the various thermochemical cycles. Specific thermochemical cycles discussed include: iron sulfur cycle; iron chloride cycle; and hybrid sulfuric acid cycle.

Funk, J. E.; Soliman, M. A.; Carty, R. H.; Conger, W. L.; Cox, K. E.; Lawson, D.

1975-01-01

408

Recapitulation of the Sexual Cycle of the Primary Fungal Pathogen Cryptococcus neoformans var. gattii: Implications for an Outbreak on Vancouver Island, Canada  

Microsoft Academic Search

Cryptococcus neoformans is a human fungal pathogen that exists as three distinct varieties or sibling species: the predominantly opportunistic pathogens C. neoformans var. neoformans (serotype D) and C. neoformans var. grubii (serotype A) and the primary pathogen C. neoformans var. gattii (serotypes B and C). While serotypes A and D are cosmopolitan, serotypes B and C are typically restricted to

James A. Fraser; Ryan L. Subaran; Connie B. Nichols; Joseph Heitman

2003-01-01

409

Primary and Compensatory Roles for RB Family Members at Cell Cycle Gene Promoters That Are Deacetylated and Downregulated in Doxorubicin-Induced Senescence of Breast Cancer Cells  

Microsoft Academic Search

When treated with DNA-damaging chemotherapy agents, many cancer cells, in vivo and in vitro, undergo a terminal growth arrest and acquire a senescence-like phenotype. We investigated the molecular basis for this in breast cancer cells following a 2-hour treatment with 1 M doxorubicin. Treated cells arrested in G1 and G2 phases of the cell cycle, with concomitant reductions in S-phase

James G. Jackson; Olivia M. Pereira-Smith

2006-01-01

410

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

Microsoft Academic Search

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

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

2006-01-01

411

Use of Mixtures as Working Fluids in Ocean Thermal Energy Conversion Cycles, Phase I. Quarterly Progress Report, May 1, 1975--July 31, 1975.  

National Technical Information Service (NTIS)

During the first quarter of this project, two OTEC (Ocean Thermal Energy Conversion) mixture cycle simulators have been developed, (1) OTEC 1, a simulation of the working fluid mixture thermodynamic cycle and (2)OTEC 2--1, a simulator obtained by upgradin...

K. E. Starling L. W. Fish J. H. Christensen K. Z. Iqbal C. Lawson

1975-01-01

412

Use of Mixtures as Working Fluids in Ocean Thermal Energy Conversion Cycles, Phase I. Quarterly Progress Report, August 1, 1975--October 31, 1975.  

National Technical Information Service (NTIS)

The third in the following sequence of OTEC (Ocean Thermal Energy Conversion) mixture cycle simulators has been developed: (1) OTEC 1, a simulation of the working fluid mixture thermodynamic cycle and (2) OTEC 2--1, a simulator obtained by upgrading OTEC ...

K. E. Starling L. W. Fish C. Lawson D. Yieh

1975-01-01

413

Conversion of fossil and biomass fuels to electric power and transportation fuels by high efficiency integrated plasma fuel cell (IPFC) energy cycle  

Microsoft Academic Search

The IPFC is a high efficiency energy cycle, which converts fossil and biomass fuel to electricity and co-product hydrogen and liquid transportation fuels (gasoline and diesel). The cycle consists of two basic units, a hydrogen plasma black reactor (HPBR) which converts the carbonaceous fuel feedstock to elemental carbon and hydrogen and CO gas. The carbon is used as fuel in

Meyer Steinberg

2006-01-01

414

Long-term implications of alternative light-duty vehicle technologies for global greenhouse gas emissions and primary energy demands  

Microsoft Academic Search

This study assesses global light-duty vehicle (LDV) transport in the upcoming century, and the implications of vehicle technology advancement and fuel-switching on greenhouse gas emissions and primary energy demands. Five different vehicle technology scenarios are analyzed with and without a CO2 emissions mitigation policy using the GCAM integrated assessment model: a reference internal combustion engine vehicle scenario, an advanced internal

Page Kyle; Son H. Kim

2011-01-01

415

Charge composition of high energy heavy primary cosmic ray nuclei. Ph.D. Thesis - Catholic Univ. of Am.  

NASA Technical Reports Server (NTRS)

A detailed study of the charge composition of primary cosmic radiation for about 5000 charged nuclei from neon to iron with energies greater than 1.16 GeV/nucleon is presented. Values are obtained after corrections were made for detector dependences, atmospheric attenuation, and solar modulation. New values of 38.5, 32.4, 23.7, and 16.8 g/sq cm for the attenuation mean free paths in air for the same charge groups are presented.

Price, R. D.

1974-01-01

416

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

417

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

Microsoft Academic Search

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

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

2006-01-01

418

A life-cycle energy analysis of building materials in the Negev desert  

Microsoft Academic Search

Environmental quality has become increasingly affected by the built environment—as ultimately, buildings are responsible for the bulk of energy consumption and resultant atmospheric emissions in many countries. In recognizing this trend, research into building energy-efficiency has focused mainly on the energy required for a building's ongoing use, while the energy “embodied” in its production is often overlooked. Such an approach

N. Huberman; D. Pearlmutter

2008-01-01

419

Control design for hybrid electrical energy systems based on dc\\/dc converters duty cycle value  

Microsoft Academic Search

This paper describes a two level hierarchical control strategy for electrical energy transfers in multisource renewable energy systems. The aim of the control design is to optimise the energy transfers, according to the sources power variations and the load characteristics. For this purpose, the controller determines the operating mode of the multisource renewable energy system and the power ratio provided

Alioune Badara Mboup; Pape Alioune Ndiaye; François Guerin; Dimitri Lefebvre

420

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

Microsoft Academic Search

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

Göran Finnveden; Jessica Johansson; Per Lind; Åsa Moberg

2005-01-01

421

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

422

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

423

Prospects for energy recovering from plastic waste gasificators by means of MHD topping cycle  

Microsoft Academic Search

In this paper the authors analyse their proposal consisting of equipping a plastic waste gasification plant both with a conventional steam power plant and magnetohydrodynamic (MHD) topping cycle. One of the major advantages of this technique is the neutralization of the acid gases present in the fumes accomplished by the alkaline cations deriving from the salt used for plasma seeding.

A. Geri; N. Verdone; Alessandro Salvini

1997-01-01

424