WorldWideScience

Sample records for balance energy

  1. Energy balance measurement

    DEFF Research Database (Denmark)

    Dhurandhar, N V; Schoeller, D; Brown, A W;

    2014-01-01

    Energy intake (EI) and physical activity energy expenditure (PAEE) are key modifiable determinants of energy balance, traditionally assessed by self-report despite its repeated demonstration of considerable inaccuracies. We argue here that it is time to move from the common view that self-reports...... of energy balance.International Journal of Obesity advance online publication, 23 December 2014; doi:10.1038/ijo.2014.199.......Energy intake (EI) and physical activity energy expenditure (PAEE) are key modifiable determinants of energy balance, traditionally assessed by self-report despite its repeated demonstration of considerable inaccuracies. We argue here that it is time to move from the common view that self......-reports of EI and PAEE are imperfect, but nevertheless deserving of use, to a view commensurate with the evidence that self-reports of EI and PAEE are so poor that they are wholly unacceptable for scientific research on EI and PAEE. While new strategies for objectively determining energy balance...

  2. Energy balance in peridynamics.

    Energy Technology Data Exchange (ETDEWEB)

    Lehoucq, Richard B.; Silling, Stewart Andrew

    2010-09-01

    The peridynamic model of solid mechanics treats internal forces within a continuum through interactions across finite distances. These forces are determined through a constitutive model that, in the case of an elastic material, permits the strain energy density at a point to depend on the collective deformation of all the material within some finite distance of it. The forces between points are evaluated from the Frechet derivative of this strain energy density with respect to the deformation map. The resulting equation of motion is an integro-differential equation written in terms of these interparticle forces, rather than the traditional stress tensor field. Recent work on peridynamics has elucidated the energy balance in the presence of these long-range forces. We have derived the appropriate analogue of stress power, called absorbed power, that leads to a satisfactory definition of internal energy. This internal energy is additive, allowing us to meaningfully define an internal energy density field in the body. An expression for the local first law of thermodynamics within peridynamics combines this mechanical component, the absorbed power, with heat transport. The global statement of the energy balance over a subregion can be expressed in a form in which the mechanical and thermal terms contain only interactions between the interior of the subregion and the exterior, in a form anticipated by Noll in 1955. The local form of this first law within peridynamics, coupled with the second law as expressed in the Clausius-Duhem inequality, is amenable to the Coleman-Noll procedure for deriving restrictions on the constitutive model for thermomechanical response. Using an idea suggested by Fried in the context of systems of discrete particles, this procedure leads to a dissipation inequality for peridynamics that has a surprising form. It also leads to a thermodynamically consistent way to treat damage within the theory, shedding light on how damage, including the

  3. Appetite and energy balancing.

    Science.gov (United States)

    Rogers, Peter J; Brunstrom, Jeffrey M

    2016-10-01

    pleasure of eating it. The latter, which is similar to food reward, is determined primarily by the state of emptiness of the gut and food liking related to the food's sensory qualities and macronutrient value and the individual's dietary history. Importantly, energy density adds value because energy dense foods are less satiating kJ for kJ and satiation limits further intake. That is, energy dense foods promote energy intake by virtue (1) of being more attractive and (2) having low satiating capacity kJ for kJ, and (1) is partly a consequence of (2). Energy storage is adapted to feast and famine and that includes unevenness over time of the costs of obtaining and ingesting food compared with engaging in other activities. However, in very low-cost food environments with energy dense foods readily available, risk of obesity is high. This risk can be and is mitigated by dietary restraint, which in its simplest form could mean missing the occasional meal. Another strategy we discuss is the energy dilution achieved by replacing some sugar in the diet with low-calorie sweeteners. Perhaps as or more significant, though, is that belief in short-term energy balancing (the energy depletion model) may undermine attempts to eat less. Therefore, correcting narratives of eating to be consistent with biological reality could also assist with weight control.

  4. Dairy Proteins and Energy Balance

    DEFF Research Database (Denmark)

    Bendtsen, Line Quist

    High protein diets affect energy balance beneficially through decreased hunger, enhanced satiety and increased energy expenditure. Dairy products are a major source of protein. Dairy proteins are comprised of two classes, casein (80%) and whey proteins (20%), which are both of high quality......, but casein is absorbed slowly and whey is absorbed rapidly. The present PhD study investigated the effects of total dairy proteins, whey, and casein, on energy balance and the mechanisms behind any differences in the effects of the specific proteins. The results do not support the hypothesis that dairy...... proteins, whey or casein are more beneficial than other protein sources in the regulation of energy balance, and suggest that dairy proteins, whey or casein seem to play only a minor role, if any, in the prevention and treatment of obesity....

  5. Energy balance in motor vehicles

    Science.gov (United States)

    Dziubńiski, M.; Drozd, A.; Adamiec, M.; Siemionek, E.

    2016-09-01

    This paper present the concept of testing energy balance. The test was conducted on the test bench equipped with the alternator, battery and standard mounted current receivers. The course of measurements consisted in recording the indications of three ammeters and a tachometer. On the basis of the recorded current values, it was possible to determine: energy received from the battery, consumed by the receivers and the energy drawn from the alternator.

  6. Balancing energy flexibilities through aggregation

    DEFF Research Database (Denmark)

    Valsomatzis, Emmanouil; Hose, Katja; Pedersen, Torben Bach

    2014-01-01

    One of the main goals of recent developments in the Smart Grid area is to increase the use of renewable energy sources. These sources are characterized by energy fluctuations that might lead to energy imbalances and congestions in the electricity grid. Exploiting inherent flexibilities, which exist...... in both energy production and consumption, is the key to solving these problems. Flexibilities can be expressed as flex-offers, which due to their high number need to be aggregated to reduce the complexity of energy scheduling. In this paper, we discuss balance aggregation techniques that already during...

  7. Energy Balance and Physical Activity

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The prevalence of obesity is increasing in most parts of theworld and becoming one of the major global public health problems. Although the components of energy balance have not been adequately estimated over time, available evidence suggests that the increase in obesity is the result of reduced physical activity. Increases in physical activity have been shown to be strongly associated with improving physical fitness and body composition, with probably a positive effect on resting metabolic rate. The Surgeon General's Report on Physical Activity and Health advocates that 30 min of regular, moderate-intensity physical activity is associated with decreases in the risk of chronic diseases and may contribute to quality of life. However, the small changes that contribute 10 min for 3 times a day for aerobic training, or one set instead of three sets of repetitions on resistance training will provide individuals with health benefits. Indeed, nutrition and physical activity should be considered an integral part of fitness and good health, and should be encouraged in all age groups, particularly early in life. The question is no longer centered around the health benefit of increasing physical activity, but rather creating self awareness and behavior changes in individuals. Hence, effective intervention programs are needed that foster long term changes in physical activity. Among various interventions, the Nutrifit program was recently conducted in Thailand and found to improve health related fitness in children. The development of more effective interventions and approaches is a major challenge in this field today.

  8. Balancing energy strategies in electricity portfolio management

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Christoph; Rachev, Svetlozar T. [Karlsruhe University, Karlsruhe (Germany); Fabozzi, Frank J. [Yale School of Management, New Haven, CT (United States)

    2011-01-15

    Traditional management of electricity portfolios is focused on the day-ahead market and futures of longer maturity. Within limits, market participants can however also resort to the balancing energy market to close their positions. In this paper, we determine strategic positions in the balancing energy market and identify corresponding economic incentives in an analysis of the German balancing energy demand. We find that those strategies allow an economically optimal starting point for real-time balancing and create a marketplace for flexible capacity that is more open than alternative marketplaces. The strategies we proffer in this paper we believe will contribute to an effective functioning of the electricity market. (author)

  9. Energy Balance and Physical Activity

    Institute of Scientific and Technical Information of China (English)

    KALLAYAKIJBOONCHOO

    2001-01-01

    The prevalence of obesity is increasing in most parts of the world and becoming one of the major global public health problems.Although the components of energy balance have not been adequately estimated over time,available evidence suggests that the increase in obesity is the result of reduced physical activity.Increases in physical activity have been showen to be strongly associated with improving physical fitness and body composition,with probably a positive effect on resting metabolic rate.The Surgeon General's Report on physical Activity and Health advocates that 30 min of regular,moderate-intensity physical activity is associated with decreases in the risk of chronic diseases and may contribute to quality of life.However,the small changes that contribute 10 min for 3 times a day for 3 times a day for aerobic training,or one set instead of three sets of repetitions on resistance training will provide individuals training,or one set instead of three sets of repetitions on resistance training will provide individuals with health benefits.Indeed,nutrition and physical activity should be considered an integral part of fitness and good health,and should be encouraged in all age groups,particularly early in life,The question is no longer centerd around the health benefit of increasing physical activity,but rather creating self awareness and behavior changes in individuals,Hence,effective intervention programs are needed that foster long term changes in physical activity.Among various interventions,the Nutrifit program was recently conducted in Thailand and found to improve health related fitness in children,The development of more effective interventions and approaches is a major challege in this field today.

  10. Comprehensive Energy Balance Measurements in Mice.

    Science.gov (United States)

    Moir, Lee; Bentley, Liz; Cox, Roger D

    2016-09-01

    In mice with altered body composition, establishing whether it is food intake or energy expenditure, or both, that is the major determinant resulting in changed energy balance is important. In order to ascertain where the imbalance is, the acquisition of reproducible data is critical. Therefore, here we provide detailed descriptions of how to determine energy balance in mice. This encompasses protocols for establishing energy intake from home cage measurement of food intake, determining energy lost in feces using bomb calorimetry, and using equations to calculate parameters such as energy intake (EI), digested energy intake (DEI), and metabolisable energy intake (MEI) to determine overall energy balance. We also discuss considerations that should be taken into account when planning these experiments, including diet and sample sizes. © 2016 by John Wiley & Sons, Inc.

  11. Tuscany (Italy) 1990 regional energy balance

    Energy Technology Data Exchange (ETDEWEB)

    Gazzarrini, M.; Santoprete, G. (Pisa Univ. (Italy). Dipt. di Economia Aziendale)

    This paper first discusses the overall problems involved in the preparation of functional and reliable regional energy balance sheets. It then presents and analyzes the 1990 energy balance sheet prepared for the Tuscany Region of Italy. The problems cited basically deal with the availability, compatibility and accuracy of regional energy data. Trends in Tuscany's energy consumption are compared with national figures in order to give some useful indications as to future energy strategies to be taken into consideration by the regional administration. In fact, this Region reflects the main national energy policy weakness - over-dependency on foreign supplied petroleum. It is thus recommended that locally available geothermal energy sources be further developed.

  12. Energy Balance of Rural Ecosystems In India

    Science.gov (United States)

    Chhabra, A.; Madhava Rao, V.; Hermon, R. R.; Garg, A.; Nag, T.; Bhaskara Rao, N.; Sharma, A.; Parihar, J. S.

    2014-11-01

    India is predominantly an agricultural and rural country. Across the country, the villages vary in geographical location, area, human and livestock population, availability of resources, agricultural practices, livelihood patterns etc. This study presents an estimation of net energy balance resulting from primary production vis-a-vis energy consumption through various components in a "Rural Ecosystem". Seven sites located in different agroclimatic regions of India were studied. An end use energy accounting "Rural Energy Balance Model" is developed for input-output analysis of various energy flows of production, consumption, import and export through various components of crop, trees outside forest plantations, livestock, rural households, industry or trade within the village system boundary. An integrated approach using field, ancillary, GIS and high resolution IRS-P6 Resourcesat-2 LISS IV data is adopted for generation of various model inputs. The primary and secondary field data collection of various energy uses at household and village level were carried out using structured schedules and questionnaires. High resolution multi-temporal Resourcesat-2 LISS IV data (2013-14) was used for generating landuse/landcover maps and estimation of above-ground Trees Outside Forests phytomass. The model inputs were converted to energy equivalents using country-specific energy conversion factors. A comprehensive geotagged database of sampled households and available resources at each study site was also developed in ArcGIS framework. Across the study sites, the estimated net energy balance ranged from -18.8 Terra Joules (TJ) in a high energy consuming Hodka village, Gujarat to 224.7 TJ in an agriculture, aquaculture and plantation intensive Kollaparru village, Andhra Pradesh. The results indicate that the net energy balance of a Rural Ecosystem is largely driven by primary production through crops and natural vegetation. This study provides a significant insight to policy

  13. Dairy beverages and energy balance

    DEFF Research Database (Denmark)

    Astrup, Arne; Chaput, Jean-Philippe; Gilbert, Jo-Anne

    2010-01-01

    High dairy intakes have been associated with lower rates of obesity in observational studies, but mechanisms to explain the association are lacking. A high intake of dairy protein reduces spontaneous food intake and may be one important mechanism, but more specific effects of dairy calcium seem...... to exist. We have found that high versus low calcium intakes from dairy products had no effect on 24-h energy expenditure or substrate oxidation rates, but fecal fat excretion increased approximately 2.5-fold on the high-calcium diets. In a meta-analysis of intervention studies we found that increasing...... dairy calcium intake by 1200mg/day resulted in increased fecal fat excretion by 5.2 (1.6-8.8) g/day. Newer research shows that humans possess taste receptors for calcium in the gastrointestinal tract and that signaling may be linked to appetite regulation. A new line of evidence suggests...

  14. The Energy Balance Experiment EBEX-2000. Part I: Overview and energy balance

    NARCIS (Netherlands)

    Oncley, S.P.; Foken, T.; Vogt, R.; Kohsiek, W.; Debruin, H.A.R.; Bernhofer, C.; Christen, A.; Gorsel, van E.; Grantz, D.; Feigenwinter, C.; Lehner, I.; Liebethal, C.; Liu, H.; Mauder, M.; Pitacco, A.; Ribeiro, L.; Weidinger, T.

    2007-01-01

    An overview of the Energy Balance Experiment (EBEX-2000) is given. This experiment studied the ability of state-of-the-art measurements to close the surface energy balance over a surface (a vegetative canopy with large evapotranspiration) where closure has been difficult to obtain. A flood-irrigated

  15. Stochastic energy balancing in substation energy management

    Directory of Open Access Journals (Sweden)

    Hassan Shirzeh

    2015-12-01

    Full Text Available In the current research, a smart grid is considered as a network of distributed interacting nodes represented by renewable energy sources, storage and loads. The source nodes become active or inactive in a stochastic manner due to the intermittent nature of natural resources such as wind and solar irradiance. Prediction and stochastic modelling of electrical energy flow is a critical task in such a network in order to achieve load levelling and/or peak shaving in order to minimise the fluctuation between off-peak and peak energy demand. An effective approach is proposed to model and administer the behaviour of source nodes in this grid through a scheduling strategy control algorithm using the historical data collected from the system. The stochastic model predicts future power consumption/injection to determine the power required for storage components. The stochastic models developed based on the Box-Jenkins method predict the most efficient state of the electrical energy flow between a distribution network and nodes and minimises the peak demand and off-peak consumption of acquiring electrical energy from the main grid. The performance of the models is validated against the autoregressive moving average (ARIMA and the Markov chain models used in previous work. The results demonstrate that the proposed method outperforms both the ARIMA and the Markov chain model in terms of forecast accuracy. Results are presented, the strengths and limitations of the approach are discussed, and possible future work is described.

  16. Balancing the Energy-Water Nexus

    Energy Technology Data Exchange (ETDEWEB)

    Dell, Jan

    2010-09-15

    Optimizing the complex tradeoffs in the Energy-Water Nexus requires quantification of energy use, carbon emitted and water consumed. Water is consumed in energy production and is often a constraint to operations. More global attention and investment has been made on reducing carbon emissions than on water management. Review of public reporting by the largest 107 global power producers and 50 companies in the oil/gas industry shows broad accounting on carbon emissions but only partial reporting on water consumption metrics. If the Energy-Water Nexus is to be balanced, then water must also be measured to be optimally managed with carbon emissions.

  17. Nexus of poverty, energy balance and health.

    Science.gov (United States)

    Mishra, C P

    2012-04-01

    Since the inception of planning process in India, health planning was an integral component of socio-economic planning. Recommendations of several committees, policy documents and Millennium development goals were instrumental in development of impressive health infrastructure. Several anti-poverty and employment generation programmes were instituted to remove poverty. Spectacular achievements took place in terms of maternal and child health indicators and expectancy of life at birth. However, communicable diseases and undernutrition remain cause of serious concern and non-communicable diseases are imposing unprecedented challenge to planners and policy makers. Estimates of poverty based on different criteria point that it has remained a sustained problem in the country and emphasizes on revisiting anti-poverty programmes, economic policies and social reforms. Poverty affects purchasing power and thereby, food consumption. Energy intake data has inherent limitations. It must be assessed in terms of energy expenditure. Energy balance has been least explored area of research. The studies conducted in three different representative population group of Eastern Uttar Pradesh revealed that 69.63% rural adolescent girls (10-19 years), 79.9% rural reproductive age group females and 62.3% rural geriatric subjects were in negative energy balance. Negative energy balance was significantly less in adolescent girls belonging to high SES (51.37%), having main occupation of family as business (55.3%), and highest per capita income group (57.1%) with respect to their corresponding sub-categories. In case of rural reproductive age groups, this was maximum (93.0%) in SC/ST category and least (65.7%) in upper caste group. In case of geriatric group, higher adjusted Odd's Ratio for negative energy balance for subjects not cared by family members (AOR 23.43, CI 3.93-139.56), not kept money (AOR 5.27, CI 1.58-17.56), belonging to lower and upper middle SES by Udai Pareekh Classification

  18. Solar energy resources not accounted in Brazilian National Energy Balance

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Paulo Cesar da Costa [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Mecanica], Emails: pinheiro@netuno.Lcc.ufmg.br, pinheiro@demec.ufmg.br

    2009-07-01

    The main development vector of a society is the energy. The solar energy is the main energy source on the planet earth. Brazil is a tropical country, and the incident solar energy on its soil (15 trillion MWh/year) is 20,000 times its annual oil production. Several uses of solar energy are part of our lives in a so natural way that it despised in the consumption and use energy balance. In Brazil, solar energy is used directly in many activities and not accounted for in Energy Balance (BEN 2007), consisting of a virtual power generation. This work aims to make a preliminary assessment of solar energy used in different segments of the Brazilian economy. (author)

  19. Importance of energy balance in agriculture.

    Science.gov (United States)

    Meco, R.; Moreno, M. M.; Lacasta, C.; Tarquis, A. M.; Moreno, C.

    2012-04-01

    Since the beginning, man has tried to control nature and the environment, and the use of energy, mainly from non-renewable sources providing the necessary power for that. The consequences of this long fight against nature has reached a critical state of unprecedented worldwide environmental degradation, as evidenced by the increasing erosion of fertile lands, the deforestation processes, the pollution of water, air and land by agrochemicals, the loss of plant and animal species, the progressive deterioration of the ozone layer and signs of global warming. This is exacerbated by the increasing population growth, implying a steady increase in consumption, and consequently, in the use of energy. Unfortunately, all these claims are resulting in serious economic and environmental problems worldwide. Because the economic and environmental future of the countries is interrelated, it becomes necessary to adopt sustainable development models based on the use of renewable and clean energies, the search for alternative resources and the use of productive systems more efficient from an energy standpoint, always with a reduction of greenhouse gas emissions. In relation to the agricultural sector, the question we ask is: how long can we keep the current energy-intensive agricultural techniques in developed countries? To analyze this aspect, energy balance is a very helpful tool because can lead to more efficient, sustainable and environment-friendly production systems for each agro-climatic region. This requires the identification of all the inputs and the outputs involved and their conversion to energy values by means of corresponding energy coefficients or equivalents (International Federation of Institutes for Advanced Studies). Energy inputs (EI) can be divided in direct (energy directly used in farms as fuel, machines, fertilizers, seeds, herbicides, human labor, etc.) and indirect (energy not consumed in the farm but in the elaboration, manufacturing or manipulation of

  20. Balancing Energy Processes in Turbine Engines

    Directory of Open Access Journals (Sweden)

    Balicki Włodzimierz

    2015-01-01

    Full Text Available The article discusses the issue of balancing energy processes in turbine engines in operation in aeronautic and marine propulsion systems with the aim to analyse and evaluate basic operating parameters. The first part presents the problem of enormous amounts of energy needed for driving fans and compressors of the largest contemporary turbofan engines commonly used in long-distance aviation. The amounts of the transmitted power and the effect of flow parameters and constructional properties of the engines on their performance and real efficiency are evaluated. The second part of the article, devoted to marine applications of turbine engines, presents the energy balance of the kinetic system of torque transmission from main engine turbines to screw propellers in the combined system of COGAG type. The physical model of energy conversion processes executed in this system is presented, along with the physical model of gasodynamic processes taking place in a separate driving turbine of a reversing engine. These models have made the basis for formulating balance equations, which then were used for analysing static and dynamic properties of the analysed type of propulsion, in particular in the aspect of mechanical loss evaluation in its kinematic system.

  1. Sustainable Urban Regeneration Based on Energy Balance

    Directory of Open Access Journals (Sweden)

    Sacha Silvester

    2012-07-01

    Full Text Available In this paper, results are reported of a technology assessment of the use and integration of decentralized energy systems and storage devices in an urban renewal area. First the general context of a different approach based on 'rethinking' and the incorporation of ongoing integration of coming economical and environmental interests on infrastructure, in relation to the sustainable urban development and regeneration from the perspective of the tripod people, technology and design is elaborated. However, this is at different scales, starting mainly from the perspective of the urban dynamics. This approach includes a renewed look at the ‘urban metabolism’ and the role of environmental technology, urban ecology and environment behavior focus. Second, the potential benefits of strategic and balanced introduction and use of decentralized devices and electric vehicles (EVs, and attached generation based on renewables are investigated in more detail in the case study of the ‘Merwe-Vierhaven’ area (MW4 in the Rotterdam city port in the Netherlands. In order to optimize the energy balance of this urban renewal area, it is found to be impossible to do this by tuning the energy consumption. It is more effective to change the energy mix and related infrastructures. However, the problem in existing urban areas is that often these areas are restricted to a few energy sources due to lack of available space for integration. Besides this, energy consumption in most cases is relatively concentrated in (existing urban areas. This limits the potential of sustainable urban regeneration based on decentralized systems, because there is no balanced choice regarding the energy mix based on renewables and system optimization. Possible solutions to obtain a balanced energy profile can come from either the choice to not provide all energy locally, or by adding different types of storage devices to the systems. The use of energy balance based on renewables as a

  2. Surface Energy Balance System (SEBS) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Cook, D. R. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    A Surface Energy Balance System (SEBS) has been installed collocated with each deployed Eddy Correlation Flux Measurement System (ECOR) at the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site, North Slope of Alaska (NSA) site, first ARM Mobile Facility (AMF1), second ARM Mobile Facility (AMF2), and third ARM Mobile Facility (AMF3) at Oliktok Point (OLI). A SEBS was also deployed with the Tropical Western Pacific (TWP) site, before it was decommissioned. Data from these sites, including the retired TWP, are available in the ARM Data Archive. The SEBS consists of upwelling and downwelling solar and infrared radiometers within one net radiometer, a wetness sensor, and soil measurements. The SEBS measurements allow the comparison of ECOR sensible and latent heat fluxes with the energy balance determined from the SEBS and provide information on wetting of the sensors for data quality purposes.

  3. Energy-balanced algorithm for RFID estimation

    Science.gov (United States)

    Zhao, Jumin; Wang, Fangyuan; Li, Dengao; Yan, Lijuan

    2016-10-01

    RFID has been widely used in various commercial applications, ranging from inventory control, supply chain management to object tracking. It is necessary for us to estimate the number of RFID tags deployed in a large area periodically and automatically. Most of the prior works use passive tags to estimate and focus on designing time-efficient algorithms that can estimate tens of thousands of tags in seconds. But for a RFID reader to access tags in a large area, active tags are likely to be used due to their longer operational ranges. But these tags use their own battery as energy supplier. Hence, conserving energy for active tags becomes critical. Some prior works have studied how to reduce energy expenditure of a RFID reader when it reads tags IDs. In this paper, we study how to reduce the amount of energy consumed by active tags during the process of estimating the number of tags in a system and make the energy every tag consumed balanced approximately. We design energy-balanced estimation algorithm that can achieve our goal we mentioned above.

  4. Effects of hypothalamic neurodegeneration on energy balance.

    Directory of Open Access Journals (Sweden)

    Allison Wanting Xu

    2005-12-01

    Full Text Available Normal aging in humans and rodents is accompanied by a progressive increase in adiposity. To investigate the role of hypothalamic neuronal circuits in this process, we used a Cre-lox strategy to create mice with specific and progressive degeneration of hypothalamic neurons that express agouti-related protein (Agrp or proopiomelanocortin (Pomc, neuropeptides that promote positive or negative energy balance, respectively, through their opposing effects on melanocortin receptor signaling. In previous studies, Pomc mutant mice became obese, but Agrp mutant mice were surprisingly normal, suggesting potential compensation by neuronal circuits or genetic redundancy. Here we find that Pomc-ablation mice develop obesity similar to that described for Pomc knockout mice, but also exhibit defects in compensatory hyperphagia similar to what occurs during normal aging. Agrp-ablation female mice exhibit reduced adiposity with normal compensatory hyperphagia, while animals ablated for both Pomc and Agrp neurons exhibit an additive interaction phenotype. These findings provide new insight into the roles of hypothalamic neurons in energy balance regulation, and provide a model for understanding defects in human energy balance associated with neurodegeneration and aging.

  5. The Energy Landscape of Social Balance

    CERN Document Server

    Marvel, Seth A; Kleinberg, Jon M

    2009-01-01

    We model a close-knit community of friends and enemies as a fully connected network with positive and negative signs on its edges. Theories from social psychology suggest that certain sign patterns are more stable than others. This notion of social "balance" allows us to define an energy landscape for such networks. Its structure is complex: numerical experiments reveal a landscape dimpled with local minima of widely varying depths. We derive rigorous bounds on the energies of these local minima and prove that they have a modular structure that can be used to classify them.

  6. Energy balance comparison of sorghum and sunflower

    Science.gov (United States)

    Rachidi, F.; Kirkham, M. B.; Kanemasu, E. T.; Stone, L. R.

    1993-03-01

    An understanding of the energy exchange processes at the surface of the earth is necessary for studies of global climate change. If the climate becomes drier, as is predicted for northern mid-latitudes, it is important to know how major agricultural crops will play a role in the budget of heat and moisture. Thus, the energy balance components of sorghum [ Sorghum bicolor (L.) Moench.] and sunflower ( Helianthus annuus L.), two drought-resistant crops grown in the areas where summertime drying is forecasted, were compared. Soil water content and evapotranspiration ( ET) rates also were determined. Net radiation was measured with net radiometers. Soil heat flux was analyzed with heat flux plates and thermocouples. The Bowen ratio method was used to determine sensible and latent heat fluxes. Sunflower had a higher evapotranspiration rate and depleted more water from the soil than sorghum. Soil heat flux into the soil during the daytime was greater for sorghum than sunflower, which was probably the result of the more erect leaves of sorghum. Nocturnal net radiation loss from the sorghum crop was greater than that from the sunflower crop, perhaps because more heat was stored in the soil under the sorghum crop. But daytime net radiation values were similar for the two crops. The data indicated that models of climate change must differentiate nighttime net radiation of agricultural crops. Sensible heat flux was not always less (or greater) for sorghum compared to sunflower. Sunflower had greater daytime values for latent heat flux, reflecting its greater depletion of water from the soil. Evapotranspiration rates determined by the energy balance method agreed relatively well with those found by the water balance method. For example, on 8 July (43 days after planting), the ET rates found by the energy-balance and water-balance methods were 4.6 vs. 5.5 mm/day for sunflower, respectively; for sorghum, these values were 4.0 vs. 3.5 mm/day, respectively. If the climate does

  7. Dorsomedial hypothalamic NPY and energy balance control.

    Science.gov (United States)

    Bi, Sheng; Kim, Yonwook J; Zheng, Fenping

    2012-12-01

    Neuropeptide Y (NPY) is a potent hypothalamic orexigenic peptide. Within the hypothalamus, Npy is primarily expressed in the arcuate nucleus (ARC) and the dorsomedial hypothalamus (DMH). While the actions of ARC NPY in energy balance control have been well studied, a role for DMH NPY is still being unraveled. In contrast to ARC NPY that serves as one of downstream mediators of actions of leptin in maintaining energy homeostasis, DMH NPY is not under the control of leptin. Npy gene expression in the DMH is regulated by brain cholecystokinin (CCK) and other yet to be identified molecules. The findings of DMH NPY overexpression or induction in animals with increased energy demands and in certain rodent models of obesity implicate a role for DMH NPY in maintaining energy homeostasis. In support of this view, adeno-associated virus (AAV)-mediated overexpression of NPY in the DMH causes increases in food intake and body weight and exacerbates high-fat diet-induced hyperphagia and obesity. Knockdown of NPY in the DMH via AAV-mediated RNAi ameliorates hyperphagia, obesity and glucose intolerance of Otsuka Long-Evans Tokushima Fatty rats in which DMH NPY overexpression has been proposed to play a causal role. NPY knockdown in the DMH also prevents high-fat diet-induced hyperphagia, obesity and impaired glucose homeostasis. A detailed examination of actions of DMH NPY reveals that DMH NPY specifically affects nocturnal meal size and produces an inhibitory action on within meal satiety signals. In addition, DMH NPY modulates energy expenditure likely through affecting brown adipocyte formation and thermogenic activity. Overall, the recent findings provide clear evidence demonstrating critical roles for DMH NPY in energy balance control, and also imply a potential role for DMH NPY in maintaining glucose homeostasis.

  8. Energy Balance Bowen Ratio (EBBR) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Cook, D. R. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    The Energy Balance Bowen Ratio (EBBR) system produces 30-minute estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity (RH). Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.

  9. Energy Balance Bowen Ratio Station (EBBR) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Cook, DR

    2011-02-23

    The energy balance Bowen ratio (EBBR) system produces 30-minute estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity (RH). Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.

  10. High-intensity sweeteners and energy balance.

    Science.gov (United States)

    Swithers, Susan E; Martin, Ashley A; Davidson, Terry L

    2010-04-26

    Recent epidemiological evidence points to a link between a variety of negative health outcomes (e.g. metabolic syndrome, diabetes and cardiovascular disease) and the consumption of both calorically sweetened beverages and beverages sweetened with high-intensity, non-caloric sweeteners. Research on the possibility that non-nutritive sweeteners promote food intake, body weight gain, and metabolic disorders has been hindered by the lack of a physiologically-relevant model that describes the mechanistic basis for these outcomes. We have suggested that based on Pavlovian conditioning principles, consumption of non-nutritive sweeteners could result in sweet tastes no longer serving as consistent predictors of nutritive postingestive consequences. This dissociation between the sweet taste cues and the caloric consequences could lead to a decrease in the ability of sweet tastes to evoke physiological responses that serve to regulate energy balance. Using a rodent model, we have found that intake of foods or fluids containing non-nutritive sweeteners was accompanied by increased food intake, body weight gain, accumulation of body fat, and weaker caloric compensation, compared to consumption of foods and fluids containing glucose. Our research also provided evidence consistent with the hypothesis that these effects of consuming saccharin may be associated with a decrement in the ability of sweet taste to evoke thermic responses, and perhaps other physiological, cephalic phase, reflexes that are thought to help maintain energy balance.

  11. Brazilian energy balance 1999: 1983 to 1998 period

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in every sector of the Brazilian economy, for the 1983 to 1998 period. It is divided into nine chapters, as follows: summary; energy supply and consumption by source; energy consumption by sector; energy import and export; transformation centers balances; energy resources and reserves; energy and socio economy; energy data relating to brazilian states; and appendices - installed capacity, world data, general structure of the balance, information processing, conversion units and consolidated energy balance.

  12. Brazilian energy balance 1996: 1980 to 1995 period

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in every sector of the Brazilian economy, for the 1980 to 1995 period. It`s divided into nine chapters, as follows: summary; energy supply and consumption by source; energy import and export; transformation centers balances; energy sources and reserves; energy and socio economy; regional parameters; and appendices - installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances 1 fig., 68 graphs., 145 tabs.

  13. Energy Balance and Body Weight Regulation

    Institute of Scientific and Technical Information of China (English)

    Chris Melby; Matt Hickey

    2006-01-01

    @@ KEY POINTS · Thermodynamic laws dictate that an excess of food energy intake relative to energy expenditure will lead to energy storage-an accumulation of fat. Conversely, a deficit of energy intake relative to expenditure will lead to a loss of body energy stores and a reduced body weight.

  14. The brain endocannabinoid system in the regulation of energy balance.

    Science.gov (United States)

    Richard, Denis; Guesdon, Benjamin; Timofeeva, Elena

    2009-02-01

    The role played by the endocannabinoid system in the regulation of energy balance is currently generating a great amount of interest among several groups of investigators. This interest in large part comes from the urgent need to develop anti-obesity and anti-cachexia drugs around target systems (such as the endocannabinoid system), which appears to be genuinely involved in energy balance regulation. When activated, the endocannabinoid system favors energy deposition through increasing energy intake and reducing energy expenditure. This system is activated in obesity and following food deprivation, which further supports its authentic function in energy balance regulation. The cannabinoid receptor type 1 (CB1), one of the two identified cannabinoid receptors, is expressed in energy-balance brain structures that are also able to readily produce or inactivate N-arachidonoyl ethanolamine (anandamide) and 2-arachidonoylglycerol (2AG), the most abundantly formed and released endocannabinoids. The brain action of endocannabinoid system on energy balance seems crucial and needs to be delineated in the context of the homeostatic and hedonic controls of food intake and energy expenditure. These controls require the coordinated interaction of the hypothalamus, brainstem and limbic system and it appears imperative to unravel those interplays. It is also critical to investigate the metabolic endocannabinoid system while considering the panoply of functions that the endocannabinoid system fulfills in the brain and other tissues. This article aims at reviewing the potential mechanisms whereby the brain endocannabinoid system influences the regulation energy balance.

  15. Serotonin and the regulation of mammalian energy balance.

    Directory of Open Access Journals (Sweden)

    Michael H Donovan

    2013-03-01

    Full Text Available Maintenance of energy balance requires regulation of the amount and timing of food intake. Decades of experiments utilizing pharmacological and later genetic manipulations have demonstrated the importance of serotonin signaling in this regulation. Much progress has been made in recent years in understanding how central nervous system serotonin systems acting through a diverse array of serotonin receptors impact feeding behavior and metabolism. Particular attention has been paid to mechanisms through which serotonin impacts energy balance pathways within the hypothalamus. How upstream factors relevant to energy balance regulate the release of hypothalamic serotonin is less clear, but work addressing this issue is underway. Generally, investigation into the central serotonergic regulation of energy balance has had a predominantly hypothalamocentric focus, yet nonhypothalamic structures that have been implicated in energy balance regulation also receive serotonergic innervation and express multiple subtypes of serotonin receptors. Moreover, there is a growing appreciation of the diverse mechanisms through which peripheral serotonin impacts energy balance regulation. Clearly, the serotonergic regulation of energy balance is a field characterized by both rapid advances and by an extensive and diverse set of central and peripheral mechanisms yet to be delineated.

  16. Intelligent Cooperative MAC Protocol for Balancing Energy Consumption

    Science.gov (United States)

    Wu, S.; Liu, K.; Huang, B.; Liu, F.

    To extend the lifetime of wireless sensor networks, we proposed an intelligent balanced energy consumption cooperative MAC protocol (IBEC-CMAC) based on the multi-node cooperative transmission model. The protocol has priority to access high-quality channels for reducing energy consumption of each transmission. It can also balance the energy consumption among cooperative nodes by using high residual energy nodes instead of excessively consuming some node's energy. Simulation results show that IBEC-CMAC can obtain longer network lifetime and higher energy utilization than direct transmission.

  17. Energy-Storage Balanced Reduction of Port-Hamiltonian Systems

    NARCIS (Netherlands)

    Lopezlena, Ricardo; Scherpen, Jacquelien M.A.; Fujimoto, Kenji

    2003-01-01

    Supported by the framework of dissipativity theory, a procedure based on physical energy to balance and reduce port-Hamiltonian systems with collocated inputs and outputs is presented. Additionally, some relations with the methods of nonlinear balanced reduction are exposed. Finally a structure-pres

  18. Energy balance closure at ChinaFLUX sites

    Institute of Scientific and Technical Information of China (English)

    LI Zhengquan; YU Guirui; WEN Xuefa; ZHANG Leiming; REN Chuanyou; FU Yuling

    2005-01-01

    Network of eddy covariance observation is measuring long-term carbon and water fluxes in contrasting ecosystems and climates. As one important reference of independently evaluating scalar flux estimates from eddy covariance, energy balance closure is used widely in study of carbon and water fluxes. Energy balance closure in ChinaFLUX was evaluated by statistical regression of turbulent energy fluxes (sensible and latent heat) against available energy (net radiation, soil heat flux, canopy heat storage) and the energy balance ratio (EBR) and the frequency distribution of relative errors of energy balance (δ). The trends of diurnal and seasonal variation of energy balance in ChinaFLUX were analyzed. The results indicated that the imbalance was prevalent in all observation sites, but there were little differences among sites because of the properties variation of sites. The imbalance was greater during nocturnal periods than daytime and closure was improved with friction velocity intensifying. Generally the results suggested that estimates of the scalar turbulent fluxes of sensible and latent heat were underestimated and/or that available energy was overestimated. Finally, we discussed certain factors that are contributed to the imbalance of energy, such as systematic errors associated with the sampling mismatch, systematic instrument bias, neglected energy sinks, low and high frequency loss of turbulent fluxes and advection of heat and water vapor.

  19. Melanocortin control of energy balance: evidence from rodent models.

    Science.gov (United States)

    De Jonghe, Bart C; Hayes, Matthew R; Bence, Kendra K

    2011-08-01

    Regulation of energy balance is extremely complex, and involves multiple systems of hormones, neurotransmitters, receptors, and intracellular signals. As data have accumulated over the last two decades, the CNS melanocortin system is now identified as a prominent integrative network of energy balance controls in the mammalian brain. Here, we will review findings from rat and mouse models, which have provided an important framework in which to study melanocortin function. Perhaps most importantly, this review attempts for the first time to summarize recent advances in our understanding of the intracellular signaling pathways thought to mediate the action of melanocortin neurons and peptides in control of longterm energy balance. Special attention will be paid to the roles of MC4R/MC3R, as well as downstream neurotransmitters within forebrain and hindbrain structures that illustrate the distributed control of melanocortin signaling in energy balance. In addition, distinctions and controversy between rodent species will be discussed.

  20. Suburban Energy Balance Estimates for Vancouver, B.C., Using the Bowen Ratio-Energy Balance Approach.

    Science.gov (United States)

    Kalanda, B. D.; Oke, T. R.; Spittlehouse, D. L.

    1980-07-01

    The energy balance of a suburban site in Vancouver, B.C. in late summer is presented. The balance is obtained from direct measurements of net radiation, parameterized heat storage and turbulent fluxes determined according to the Bowen ratio-energy balance method with reversing psychrometers. An error analysis shows the turbulent fluxes are good to within 10-20% by day. Features of the suburban energy balance are found to be intermediate between those previously reported for urban and rural surfaces. Average daytime Bowen ratios are usually in the range 0.5-1.0 with some days as high as 2.5. The daytime sensible heat flux is in-phase with the net radiation. At night this flux is sometimes positive. Evapotranspiration is always an important term in the balance. The role of urban irrigation and microscale heat advection in maintaining evapotranspiration rates is discussed.

  1. The energy balance of the earth' surface : a practical approach

    NARCIS (Netherlands)

    Bruin, de H.A.R.

    1982-01-01

    This study is devoted to the energy balance of the earth's surface with a special emphasis on practical applications. A simple picture of the energy exchange processes that take place at the ground is the following. Per unit time and area an amount of radiant energy is supplied to the surface. This

  2. Top 10 Research Questions Related to Energy Balance

    Science.gov (United States)

    Shook, Robin P.; Hand, Gregory A.; Blair, Steven N.

    2014-01-01

    Obesity is the result of a mismatch between the amount of calories consumed and the amount of calories expended during an extended period of time. This relationship is described by the energy balance equation, which states the rate of change in energy storage depots in the body are equal to the rate of energy intake minus the rate of energy…

  3. Energy balance in laser-irradiated vaporizing droplets

    Energy Technology Data Exchange (ETDEWEB)

    Zardecki, A.; Armstrong, R.L.

    1987-09-08

    We analyze the interactions of atmospheric aerosols with a high-energy laser beam. The energy balance equation allows us to compute the conversion of the pulse energy into temperature increase, vaporization, conduction, and convection. We also include the shrinkage term whose significance has recently been discussed by Davies and Brock.

  4. Investigations of a Cost-Optimal Zero Energy Balance

    DEFF Research Database (Denmark)

    Marszal, Anna Joanna; Nørgaard, Jesper; Heiselberg, Per

    2012-01-01

    , in particular the types of energy use that should be included in it. Since the user perspective and the cost of energy-efficiency technologies is so crucial for the successful adaptation of energy-conservation solutions, such like the Net ZEB concept, this paper has deployed the Life Cycle Cost (LCC) analysis......The Net Zero Energy Building (Net ZEB) concept is worldwide recognised as a promising solution for decreasing buildings’ energy use. Nevertheless, a consistent definition of the Net ZEB concept is constantly under discussion. One of the points on the Net ZEB agenda is the zero energy balance...... and taken a view point of private building owner to investigate what types of energy uses should be included in the cost-optimal zero energy balance. The analysis is conducted for five renewable energy supply systems and five user profiles with a study case of a multi-storey residential Net ZEB. The results...

  5. Energy and water cycle over the Tibetan plateau : surface energy balance and turbulent heat fluxes

    NARCIS (Netherlands)

    Su, Zhongbo; Zhang, Ting; Ma, Yaoming; Jia, Li; Wen, Jun

    2006-01-01

    This contribution presents an overview and an outlook of studies on energy and water cycle over the Tibetan plateau with focuses on the estimation of energy balance terms and turbulent heat fluxes. On the basis of the surface energy balance calculations, we show that the phenomena of the energy imba

  6. Energy and water cycle over the Tibetan Plateau: surface energy balance and turbulent heat fluxes

    NARCIS (Netherlands)

    Su, Z.; Zhang, T.; Ma, Y.; Jia, L.; Wen, J.

    2006-01-01

    This contribution presents an overview and an outlook of studies on energy and water cycle over the Tibetan plateau with focuses on the estimation of energy balance terms and turbulent heat fluxes. On the basis of the surface energy balance calculations, we show that the phenomena of the energy imba

  7. Introduction to energy balance of biomass production; Introduccion al calculo del balance energetico de la produccion de Biomasa

    Energy Technology Data Exchange (ETDEWEB)

    Manzanares, P.

    1997-11-01

    During last years, energy crops have been envisaged as an interesting alternative to biomass residues utilization as renewable energy source. In this work, main parameters used in calculating the energy balance of an energy crop are analyzed. The approach consists of determining energy equivalents for the different inputs and outputs of the process, thus obtaining energy ratios of the system, useful to determine if the energy balance is positive, that is, if the system generates energy. Energy costs for inputs and assessment approaches for energy crop yields (output) are provided. Finally, as a way of illustration, energy balances of some representative energy crops are shown. (Author) 15 refs.

  8. Sustainable urban regeneration based on energy balance

    NARCIS (Netherlands)

    Van Timmeren, A.; Zwetsloot, J.; Brezet, H.; Silvester, S.

    2012-01-01

    In this paper, results are reported of a technology assessment of the use and integration of decentralized energy systems and storage devices in an urban renewal area. First the general context of a different approach based on 'rethinking' and the incorporation of ongoing integration of coming econo

  9. Energy balance closure for the LITFASS-2003 experiment

    NARCIS (Netherlands)

    Foken, T.; Mauder, M.; Liebethal, C.; Wimmer, F.; Beyrich, F.; Leps, J.P.; Raasch, S.; Debruin, H.A.R.; Meijninger, W.M.L.; Bange, J.

    2010-01-01

    In the first part, this paper synthesises the main results from a series of previous studies on the closure of the local energy balance at low-vegetation sites during the LITFASS-2003 experiment. A residual of up to 25% of the available energy has been found which cannot be fully explained either by

  10. Development of Energy Balances for the State of California

    Energy Technology Data Exchange (ETDEWEB)

    Murtishaw, Scott; Price, Lynn; de la Rue du Can, Stephane; Masanet, Eric; Worrell, Ernst; Sahtaye, Jayant

    2005-12-01

    Analysts assessing energy policies and energy modelers forecasting future trends need to have access to reliable and concise energy statistics. Lawrence Berkeley National Laboratory evaluated several sources of California energy data, primarily from the California Energy Commission and the U.S. Energy Information Administration, to develop the California Energy Balance Database (CALEB). This database manages highly disaggregated data on energy supply, transformation, and end-use consumption for each type of energy commodity from 1990 to the most recent year available (generally 2001) in the form of an energy balance, following the methodology used by the International Energy Agency. This report presents the data used for CALEB and provides information on how the various data sources were reconciled. CALEB offers the possibility of displaying all energy flows in numerous ways (e.g.,physical units, Btus, petajoules, different levels of aggregation), facilitating comparisons among the different types of energy commodities and different end-use sectors. In addition to displaying energy data, CALEB can also be used to calculate state-level energy-related carbon dioxide emissions using the methodology of the Intergovernmental Panel on Climate Change.

  11. National energy balance - 1995 of Brazil. Based on 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    Consolidated data of production, consumption and external dependence of energy are presented, as also the sectorial composition of the consumption of the different groups of energy sources. For each primary and secondary source the production, import, export, variations in inventories, losses, adjustments and total consumption are analyzed. Balances of transformation centers, characterizing the energy the energy processed, the energy produced and the respective losses in transformation are shown. Finally energy resources and reserves of primary sources are described with respective methodologies for estimating them. 60 figs., 107 tabs.

  12. The Spanish Wind Energy Market. Balance and Outlooks; El Mercado Eolico Espanol. Balance y Perspectivas

    Energy Technology Data Exchange (ETDEWEB)

    Varela, M. [CIEMAT. Madrid (Spain)

    1999-06-01

    The present work accomplishes a revision to the situation of the wind market in Spain, its recent evolution, its regional distribution, the principal actors of the market (manufacturers, promoters). The balance includes a review of the programs of institutional support to wind energy, an analysis of the current installation costs and electricity production costs. Finally, other variables related the integration of wind energy are analysed, as the potential of employment generation or the associated environmental factors. (Author) 5 refs.

  13. Energy Efficient Geographical Load Balancing via Dynamic Deferral of Workload

    CERN Document Server

    Adnan, Muhammad Abdullah; Gupta, Rajesh

    2012-01-01

    With the increasing popularity of Cloud computing and Mobile computing, individuals, enterprises and research centers have started outsourcing their IT and computational needs to on-demand cloud services. Recently geographical load balancing techniques have been suggested for data centers hosting cloud computation in order to reduce energy cost by exploiting the electricity price differences across regions. However, these algorithms do not draw distinction among diverse requirements for responsiveness across various workloads. In this paper, we use the flexibility from the Service Level Agreements (SLAs) to differentiate among workloads under bounded latency requirements and propose a novel approach for cost savings for geographical load balancing. We investigate how much workload to be executed in each data center and how much workload to be delayed and migrated to other data centers for energy saving while meeting deadlines. We present an offline formulation for geographical load balancing problem with dyna...

  14. The energy balance of the solar transition region

    Science.gov (United States)

    Jordan, C.

    1980-01-01

    It is shown how the observed distribution of the emission measure with temperature can be used to limit the range of energy deposition functions suitable for heating the solar transition region and inner corona. The minimum energy loss solution is considered in view of the work by Hearn (1975) in order to establish further scaling laws between the transition region pressure, the maximum coronal temperature and the parameter giving the absolute value of the emission measure. Also discussed is the absence of a static energy balance at the base of the transition region in terms of measurable atmospheric parameters, and the condition for a static energy balance is given. In addition, the possible role of the emission from He II in stabilizing the atmosphere by providing enhanced radiation loss is considered.

  15. Energy balance and malnutrition in institutionalized elderly people

    NARCIS (Netherlands)

    Groot, de C.P.G.M.; Staveren, van W.A.

    2002-01-01

    Screening tools and more extensive assessment methods have signaled that malnutrition is common in institutionalized elderly. There are multiple factors - physiologic and non-physiologic - which hereby increase the risk of negative energy balance leading to weight loss and subsequent undesirable out

  16. Pedometer and Human Energy Balance Applications for Science Instruction

    Science.gov (United States)

    Rye, James A.; Smolski, Stefan

    2007-01-01

    Teachers can use pedometers to facilitate inquiry learning and show students the need for mathematics in scientific investigation. The authors conducted activities with secondary students that investigated intake and expenditure components of the energy balance algorithm, which led to inquiries about pedometers and related data. By investigating…

  17. Wanted: institutions for balancing global food and energy markets.

    NARCIS (Netherlands)

    Koning, N.B.J.; Mol, A.P.J.

    2009-01-01

    The increasing demand for biomass for energy use is further escalating existing food security risks. Managing these risks is a task for global institutions. These should ensure timely investment in the world's capacity for producing biomass and balance the use of this biomass for foods and for non-f

  18. State dependent matrices and balanced energy functions for nonlinear systems

    NARCIS (Netherlands)

    Scherpen, Jacquelien M.A.; Gray, W. Steven

    2000-01-01

    The nonlinear extension of the balancing procedure requires the case of state dependent quadratic forms for the energy functions, i.e., the nonlinear extensions of the linear Gramians are state dependent matrices. These extensions have some interesting ambiguities that do not occur in the linear cas

  19. Isospin dependence of balance energy in heavy-ion collisions

    CERN Document Server

    Kaur, Varinderjit; Kumar, Suneel

    2011-01-01

    Based on the isospin-dependent quantum molecular dynamics (IQMD) picture, we attempt to understand the nature of transverse flow in $_{28}Ni^{58}+_{28}Ni^{58}$ and $_{26}Fe^{58}+_{26}Fe^{58}$ systems at wide range of energies and impact parameters. The isospin dependence of balance energy in transverse flow is clearly visible. The results are compared with the experimental data available.

  20. Assessment of Global Annual Atmospheric Energy Balance from Satellite Observations

    Science.gov (United States)

    Lin, Bing; Stackhouse, Paul; Minnis, Patrick; Wielicki, Bruce A.; Hu, Yongxiang; Sun, Wenbo; Fan, Tai-Fang (Alice); Hinkelman, Laura

    2008-01-01

    Global atmospheric energy balance is one of the fundamental processes for the earth's climate system. This study uses currently available satellite data sets of radiative energy at the top of atmosphere (TOA) and surface and latent and sensible heat over oceans for the year 2000 to assess the global annual energy budget. Over land, surface radiation data are used to constrain assimilated results and to force the radiation, turbulent heat, and heat storage into balance due to a lack of observation-based turbulent heat flux estimations. Global annual means of the TOA net radiation obtained from both direct measurements and calculations are close to zero. The net radiative energy fluxes into the surface and the surface latent heat transported into the atmosphere are about 113 and 86 Watts per square meter, respectively. The estimated atmospheric and surface heat imbalances are about -8 9 Watts per square meter, values that are within the uncertainties of surface radiation and sea surface turbulent flux estimates and likely systematic biases in the analyzed observations. The potential significant additional absorption of solar radiation within the atmosphere suggested by previous studies does not appear to be required to balance the energy budget the spurious heat imbalances in the current data are much smaller (about half) than those obtained previously and debated at about a decade ago. Progress in surface radiation and oceanic turbulent heat flux estimations from satellite measurements significantly reduces the bias errors in the observed global energy budgets of the climate system.

  1. Greenhouse gas emissions and energy balance of palm oil biofuel

    Energy Technology Data Exchange (ETDEWEB)

    de Souza, Simone Pereira; Pacca, Sergio [Graduate Program on Environmental Engineering Science, School of Engineering of Sao Carlos, University of Sao Paulo, Rua Arlindo Bettio, 1000 Sao Paulo (Brazil); de Avila, Marcio Turra; Borges, Jose Luiz B. [Brazilian Agricultural Research Corporation (Embrapa - Soja) (Brazil)

    2010-11-15

    The search for alternatives to fossil fuels is boosting interest in biodiesel production. Among the crops used to produce biodiesel, palm trees stand out due to their high productivity and positive energy balance. This work assesses life cycle emissions and the energy balance of biodiesel production from palm oil in Brazil. The results are compared through a meta-analysis to previous published studies: Wood and Corley (1991) [Wood BJ, Corley RH. The energy balance of oil palm cultivation. In: PORIM intl. palm oil conference - agriculture; 1991.], Malaysia; Yusoff and Hansen (2005) [Yusoff S, Hansen SB. Feasibility study of performing an life cycle assessment on crude palm oil production in Malaysia. International Journal of Life Cycle Assessment 2007;12:50-8], Malaysia; Angarita et al. (2009) [Angarita EE, Lora EE, Costa RE, Torres EA. The energy balance in the palm oil-derived methyl ester (PME) life cycle for the cases in Brazil and Colombia. Renewable Energy 2009;34:2905-13], Colombia; Pleanjai and Gheewala (2009) [Pleanjai S, Gheewala SH. Full chain energy analysis of biodiesel production from palm oil in Thailand. Applied Energy 2009;86:S209-14], Thailand; and Yee et al. (2009) [Yee KF, Tan KT, Abdullah AZ, Lee KT. Life cycle assessment of palm biodiesel: revealing facts and benefits for sustainability. Applied Energy 2009;86:S189-96], Malaysia. In our study, data for the agricultural phase, transport, and energy content of the products and co-products were obtained from previous assessments done in Brazil. The energy intensities and greenhouse gas emission factors were obtained from the Simapro 7.1.8. software and other authors. These factors were applied to the inputs and outputs listed in the selected studies to render them comparable. The energy balance for our study was 1:5.37. In comparison the range for the other studies is between 1:3.40 and 1:7.78. Life cycle emissions determined in our assessment resulted in 1437 kg CO{sub 2}e/ha, while our analysis

  2. Energy Balance of Friction and Friction Coefficient in Energetical Interpretation

    Directory of Open Access Journals (Sweden)

    S.V. Fedorov

    2015-09-01

    Full Text Available Sliding friction energy model is proposed. In this model, generalized mechanism of transformation and dissipation of energy under friction the model of elastic-plastic deformation and fracture contact volumes is considered. Energy model of the process of plastic deformation and destruction of solid bodies is based on the concept of ergodynamic of deformable bodies. Equations of energy balance of friction within the structural and energetic interpretation of deformation are proposed. The energy interpretation of the coefficient of friction is showed. From this position the friction coefficient is the most informative characteristic of the process. Experimental friction curves have been generalized. As a result of the energy analysis of friction, the energy diagram of the structural evolution of the friction surfaces is suggested.

  3. Capsaicin increases sensation of fullness in energy balance, and decreases desire to eat after dinner in negative energy balance.

    Science.gov (United States)

    Janssens, Pilou L H R; Hursel, Rick; Westerterp-Plantenga, Margriet S

    2014-06-01

    Addition of capsaicin (CAPS) to the diet has been shown to increase satiety; therefore, CAPS is of interest for anti-obesity therapy. We investigated the effects of CAPS on appetite profile and ad libitum energy intake in relation to energy balance. Fifteen subjects (seven women and eight men, age: 29.7 ± 10.8yrs, BMI: 23.3 ± 2.9 kg/m(2)) underwent four conditions in a randomized crossover design in 36 hour sessions in a respiration chamber; they received 100% of their daily energy requirements in the conditions "100%Control" and "100%CAPS", and 75% of their daily energy requirements in the conditions "75%Control" and "75%CAPS", followed by an ad libitum dinner. In the 100%CAPS and 75%CAPS conditions, CAPS was given at a dose of 2.56 mg (1.03 g of red chili pepper, 39,050 Scoville heat units) with every meal. Satiety (P energy balance, addition of capsaicin to the diet increases satiety and fullness, and tends to prevent overeating when food intake is ad libitum. After dinner, capsaicin prevents the effects of the negative energy balance on desire to eat.

  4. Energy Balance in DC Arc Plasma Melting Furnace

    Institute of Scientific and Technical Information of China (English)

    ZHAO Peng; MENG Yuedong; YU Xinyao; CHEN Longwei; JIANG Yiman; NI Guohua; CHEN Mingzhou

    2009-01-01

    In order to treat hazardous municipal solid waste incinerator's (MSWI) fly ash, a new DC arc plasma furnace was developed. Taking an arc of 100 V/1000 A DC as an example,the heat transfer characteristics of the DC arc plasma, ablation of electrodes, heat properties of the fly ash during melting, heat transfer characteristics of the flue gas, and heat loss of the furnace were analyzed based on the energy conservation law, so as to achieve the total heat information and energy balance during plasma processing, and to provide a theoretical basis for an optimized design of the structure and to improve energy efficiency.

  5. Windows with an improved energy balance of 30%

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe

    in the guarded hotbox facility at the institute and a total U-value of about 1.2 W/(m2 K) have been measured, which is a reduction compared with the reference window of 0.2 W/(m2 K). The improvements have primarily been obtained by replacing parts of the frame construction with polystyrene foam insulation. Other....... The transparent area forms about 68% of the total window area and the total U-value of the window is about 1.4 W/(m2 K).The energy balance depends strongly of the window orientation and the thermal mass of the room behind. In order to characterize the energy balance of a window with a single value a method has...... been developed, which combines the results from several different building types and building orientations. The energy balance of the reference window has been calculated to -50 kWh/m2 window area, i.e. the refence window accounts for a net energy consumption for space heating of 50 kWh/m2 window area...

  6. Energy-Aware Load Balancing in Content Delivery Networks

    CERN Document Server

    Mathew, Vimal; Shenoy, Prashant

    2011-01-01

    Internet-scale distributed systems such as content delivery networks (CDNs) operate hundreds of thousands of servers deployed in thousands of data center locations around the globe. Since the energy costs of operating such a large IT infrastructure are a significant fraction of the total operating costs, we argue for redesigning CDNs to incorporate energy optimizations as a first-order principle. We propose techniques to turn off CDN servers during periods of low load while seeking to balance three key design goals: maximize energy reduction, minimize the impact on client-perceived service availability (SLAs), and limit the frequency of on-off server transitions to reduce wear-and-tear and its impact on hardware reliability. We propose an optimal offline algorithm and an online algorithm to extract energy savings both at the level of local load balancing within a data center and global load balancing across data centers. We evaluate our algorithms using real production workload traces from a large commercial ...

  7. Energy Balanced Redeployment Algorithm for Heterogeneous Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Guang Ye

    2015-01-01

    Full Text Available Wireless sensor networks (WSNs have gained worldwide attention in recent years. Since WSNs can be conveniently deployed to monitor a given field of interest, they have been considered as a great long-term economic potential for military, environmental, and scientific applications and so forth. One of the most active areas of research in WSNs is the coverage which is one of the most essential functions to guarantee quality of service (QoS in WSNs. However, less attention is paid on the heterogeneity of the node and the energy balance of the whole network during the redeployment process. In this work, the energy balanced problems in mobile heterogeneous WSNs redeployment have been analyzed. The virtual force algorithm with extended virtual force model is used to improve the QoS of the deployment. Furthermore energy model is added to enhance or limit the movement of the nodes so that the energy of nodes in the whole WSNs can be balanced and the lifetime of the networks can be prolonged. The simulation results verify the effectiveness of this proposed algorithm.

  8. Influences of tidal energy advection on the surface energy balance in a mangrove forest

    Directory of Open Access Journals (Sweden)

    J. G. Barr

    2012-08-01

    Full Text Available Mangrove forests are ecosystems susceptible to changing water levels and temperatures due to climate change as well as perturbations resulting from tropical storms. Numerical models can be used to project mangrove forest responses to regional and global environmental changes, and the reliability of these models depends on surface energy balance closure. However, for tidal ecosystems, the surface energy balance is complex because the energy transport associated with tidal activity remains poorly understood. This study aimed to quantify impacts of tidal flows on energy dynamics within a mangrove ecosystem. To address the research objective, an intensive study was conducted in a mangrove forest located along the Shark River in the Everglades National Park, FL. Forest-atmosphere energy exchanges were quantified with an eddy covariance system deployed on a flux tower. The lateral energy transport associated with tidal activity was calculated based on a coupled mass and energy balance approach. The mass balance included tidal flows and accumulation of water on the forest floor. The energy balance included temporal changes in enthalpy, resulting from tidal flows and temperature changes in the water column. By serving as a net sink or a source of available energy, tidal flows reduced the impact of high radiational loads on the mangrove forest. Including tidal energy advection in the surface energy balance improved the 30-min daytime energy closure from 73% to 82% over the study period. Also, the cumulative sum of energy output improved from 79% to 91% of energy input during the study period. Results indicated that tidal inundation provides an important mechanism for heat removal and that tidal exchange should be considered in surface energy budgets of coastal ecosystems. Results also demonstrated the importance of including tidal energy advection in mangrove biophysical models that are used for predicting ecosystem response to changing climate and

  9. Dynamic Response of Inextensible Beams by Improved Energy Balance Method

    DEFF Research Database (Denmark)

    Sfahani, M. G.; Barari, Amin; Omidvar, M.

    2011-01-01

    An improved He's energy balance method (EBM) for solving non-linear oscillatory differential equation using a new trial function is presented. The problem considered represents the governing equations of the non-linear, large-amplitude free vibrations of a slender cantilever beam with a rotationa......An improved He's energy balance method (EBM) for solving non-linear oscillatory differential equation using a new trial function is presented. The problem considered represents the governing equations of the non-linear, large-amplitude free vibrations of a slender cantilever beam...... procedure for a particular value of the initial condition is then used to estimate the constants. This semi-analytical representation gives excellent approximations to the exact solutions for the whole range of the oscillation amplitude, reducing the respective error of angular frequency in comparison...

  10. An Energy Balanced Algorithm of LEACH Protocol in WSN

    Directory of Open Access Journals (Sweden)

    Chunyao Fu

    2013-01-01

    Full Text Available In wireless sensor networks (WSNs, due to the limitation of nodes energy, energy efficiency is an important factor should be considered when the protocols are designing. As a typical representative of hierarchical routing protocols, LEACH Protocol plays an important role. In response to the uneven energy distribution that is caused by the randomness of cluster heads forming , this paper proposes a new improved algorithm of LEACH protocol (LEACH-TLCH which is intended to balance the energy consumption of the entire network and extend the life of the network . The new algorithm is emulated by Matlab simulation platform, the simulation results indicate that both energy efficiency and the lifetime of the network are better than that of LEACH Protocol.

  11. Reproduction and energy balance: the integrative role of prolactin

    OpenAIRE

    T I Romantsova

    2014-01-01

    The physiological mechanisms controlling reproduction are closely linked to energy balance. In the recent years, accumulating evidence suggests that prolactin regulates metabolic functions, besides regulating breast development and stimulating milk formation. Hyperprolactinemia is associated with obesity and treatment with dopamine agonists results in weight loss. We discuss the integrated effects of prolactin in the metabolic control and reproductive function, the role of prolactin in the pa...

  12. Serotonin and the regulation of mammalian energy balance

    OpenAIRE

    Michael H Donovan; Tecott, Laurence H.

    2013-01-01

    Maintenance of energy balance requires regulation of the amount and timing of food intake. Decades of experiments utilizing pharmacological and later genetic manipulations have demonstrated the importance of serotonin signaling in this regulation. Much progress has been made in recent years in understanding how central nervous system (CNS) serotonin systems acting through a diverse array of serotonin receptors impact feeding behavior and metabolism. Particular attention has been paid to mecha...

  13. Can an energy balance model provide additional constraints on how to close the energy imbalance?

    Science.gov (United States)

    Wohlfahrt, Georg; Widmoser, Peter

    2013-02-15

    Elucidating the causes for the energy imbalance, i.e. the phenomenon that eddy covariance latent and sensible heat fluxes fall short of available energy, is an outstanding problem in micrometeorology. This paper tests the hypothesis that the full energy balance, through incorporation of additional independent measurements which determine the driving forces of and resistances to energy transfer, provides further insights into the causes of the energy imbalance and additional constraints on energy balance closure options. Eddy covariance and auxiliary data from three different biomes were used to test five contrasting closure scenarios. The main result of our study is that except for nighttime, when fluxes were low and noisy, the full energy balance generally did not contain enough information to allow further insights into the causes of the imbalance and to constrain energy balance closure options. Up to four out of the five tested closure scenarios performed similarly and in up to 53% of all cases all of the tested closure scenarios resulted in plausible energy balance values. Our approach may though provide a sensible consistency check for eddy covariance energy flux measurements.

  14. Energy-momentum balance in particle - domain wall perforating collision

    CERN Document Server

    Gal'tsov, D V; Spiirin, P A

    2014-01-01

    We investigate the energy-momentum balance in the perforating collision of a point particle with an infinitely thin planar domain wall within the linearized gravity in arbitrary dimensions. Since the metric of the wall increases with distance, the wall and the particle are never free, and their energy-momentum balance involves not only the instantaneous kinetic momenta, but also the non-local contribution of gravitational stresses. However, careful analysis shows that the stresses can be unambiguously divided between the colliding objects leading to definition of the gravitationally dressed momenta. These take into account for gravity in the same way as the potential energy does in the non-relativistic theory, but our treatment is fully relativistic. Another unusual feature of our problem is the non-vanishing flux of the total energy-momentum tensor through the lateral surface of the world tube. In this case the zero divergence of the energy-momentum tensor does not imply conservation of the total momentum de...

  15. Summertime influences of tidal energy advection on the surface energy balance in a mangrove forest

    Directory of Open Access Journals (Sweden)

    J. G. Barr

    2013-01-01

    Full Text Available Mangrove forests are ecosystems susceptible to changing water levels and temperatures due to climate change as well as perturbations resulting from tropical storms. Numerical models can be used to project mangrove forest responses to regional and global environmental changes, and the reliability of these models depends on surface energy balance closure. However, for tidal ecosystems, the surface energy balance is complex because the energy transport associated with tidal activity remains poorly understood. This study aimed to quantify impacts of tidal flows on energy dynamics within a mangrove ecosystem. To address the research objective, an intensive 10-day study was conducted in a mangrove forest located along the Shark River in the Everglades National Park, FL, USA. Forest–atmosphere turbulent exchanges of energy were quantified with an eddy covariance system installed on a 30-m-tall flux tower. Energy transport associated with tidal activity was calculated based on a coupled mass and energy balance approach. The mass balance included tidal flows and accumulation of water on the forest floor. The energy balance included temporal changes in enthalpy, resulting from tidal flows and temperature changes in the water column. By serving as a net sink or a source of available energy, flood waters reduced the impact of high radiational loads on the mangrove forest. Also, the regression slope of available energy versus sink terms increased from 0.730 to 0.754 and from 0.798 to 0.857, including total enthalpy change in the water column in the surface energy balance for 30-min periods and daily daytime sums, respectively. Results indicated that tidal inundation provides an important mechanism for heat removal and that tidal exchange should be considered in surface energy budgets of coastal ecosystems. Results also demonstrated the importance of including tidal energy advection in mangrove biophysical models that are used for predicting ecosystem

  16. Irreversibility in energy processes: Non-dimensional quantification and balance

    Science.gov (United States)

    Pons, Michel

    2004-06-01

    The concept of thermodynamic efficiency (ratio of real cycle efficiency by Carnot efficiency) is well-known. The concept of numbers of entropy-production and of exergy-loss proposed by A. Bejan are also known, but rarely used. The present study firstly evidences that these two last numbers are actually identical, thus being a common number of irreversibility, independent of the method used for obtaining it. The study also evidences a non-dimensional irreversibility balance that applies to any energy conversion process. This balance correlates the thermodynamic efficiency of a whole process (which in most cases equals the exergetic efficiency) and the numbers of irreversibility of the different components or sub-processes involved in this process. Moreover, the basic additivity of entropy-productions and exergy-losses is maintained in this balance. This balance applies to the basic cycles (heat-engines, refrigerators, heat-pumps and heat-transformers), either work- or heat-powered. It also applies to more complex cycles (heat-powered cycles consuming electricity, four-temperature heat-powered cycles, cogeneration processes), thus giving a robust framework for analyzing these cycles.

  17. Dietary energy balance modulates ovarian cancer progression and metastasis.

    Science.gov (United States)

    Al-Wahab, Zaid; Tebbe, Calvin; Chhina, Jasdeep; Dar, Sajad A; Morris, Robert T; Ali-Fehmi, Rouba; Giri, Shailendra; Munkarah, Adnan R; Rattan, Ramandeep

    2014-08-15

    A high energy balance, or caloric excess, accounts as a tumor promoting factor, while a negative energy balance via caloric restriction, has been shown to delay cancer progression. The effect of energy balance on ovarian cancer progression was investigated in an isogeneic immunocompetent mouse model of epithelial ovarian cancer kept on a regimen of regular diet, high energy diet (HED) and calorie restricted diet (CRD), prior to inoculating the animals intraperitoneally with the mouse ovarian surface epithelial ID8 cancer cells. Tumor evaluation revealed that mice group on HED displayed the most extensive tumor formation with the highest tumor score at all organ sites (diaphragm, peritoneum, bowel, liver, kidney, spleen), accompanied with increased levels of insulin, leptin, insulin growth factor-1 (IGF-1), monocyte chemoattractant protein-1 (MCP-1), VEGF and interleukin 6 (IL-6). On the other hand, the mice group on CRD exhibited the least tumor burden associated with a significant reduction in levels of insulin, IGF-1, leptin, MCP-1, VEGF and IL-6. Immunohistochemistry analysis of tumors from HED mice showed higher activation of Akt and mTOR with decreased adenosine monophosphate activated kinase (AMPK) and SIRT1 activation, while tumors from the CRD group exhibited the reverse profile. In conclusion, ovarian cancer growth and metastasis occurred more aggressively under HED conditions and was significantly curtailed under CRD. The suggested mechanism involves modulated secretion of growth factors, cytokines and altered regulation of AMPK and SIRT1 that converges on mTOR inhibition. While the role of a high energy state in ovarian cancer has not been confirnmed in the literature, the current findings support investigating the potential impact of diet modulation as adjunct to other anticancer therapies and as possible individualized treatment strategy of epithelial ovarian cancer.

  18. Energy Efficient Routing in Wireless Sensor Networks Through Balanced Clustering

    Directory of Open Access Journals (Sweden)

    Christos Douligeris

    2013-01-01

    Full Text Available The wide utilization of Wireless Sensor Networks (WSNs is obstructed by the severely limited energy constraints of the individual sensor nodes. This is the reason why a large part of the research in WSNs focuses on the development of energy efficient routing protocols. In this paper, a new protocol called Equalized Cluster Head Election Routing Protocol (ECHERP, which pursues energy conservation through balanced clustering, is proposed. ECHERP models the network as a linear system and, using the Gaussian elimination algorithm, calculates the combinations of nodes that can be chosen as cluster heads in order to extend the network lifetime. The performance evaluation of ECHERP is carried out through simulation tests, which evince the effectiveness of this protocol in terms of network energy efficiency when compared against other well-known protocols.

  19. Decomposing energy balance contributions for quenched jets with CMS

    Science.gov (United States)

    Evdokimov, Olga

    2016-12-01

    Modification of energy balance in dijet events from heavy ion collisions, measured by CMS, was among the first jet quenching observations in the LHC energy domain. Here we further study the spatial extent of medium-induced modifications for such dijets, as well as potential medium response to propagating partons, using two-dimensional angular correlations of charged hadrons measured with respect to jets. New differential measurements of charged particle energy flow about the jet direction as a function of relative azimuth and relative pseudorapidity from 2.76 TeV PbPb collisions are compared with the reference pp data recorded by the CMS at the same energy. Modifications of correlated charged hadron distributions for both the leading and the subleading sides of the dijet are reported, together with comparisons of the long-range asymmetry of the underlying event in PbPb vs pp collisions.

  20. Appetite control and energy balance: impact of exercise.

    Science.gov (United States)

    Blundell, J E; Gibbons, C; Caudwell, P; Finlayson, G; Hopkins, M

    2015-02-01

    Exercise is widely regarded as one of the most valuable components of behaviour that can influence body weight and therefore help in the prevention and management of obesity. Indeed, long-term controlled trials show a clear dose-related effect of exercise on body weight. However, there is a suspicion, particularly fuelled by media reports, that exercise serves to increase hunger and drive up food intake thereby nullifying the energy expended through activity. Not everyone performing regular exercise will lose weight and several investigations have demonstrated a huge individual variability in the response to exercise regimes. What accounts for this heterogeneous response? First, exercise (or physical activity) through the expenditure of energy will influence the energy balance equation with the potential to generate an energy deficit. However, energy expenditure also influences the control of appetite (i.e. the physiological and psychological regulatory processes underpinning feeding) and energy intake. This dynamic interaction means that the prediction of a resultant shift in energy balance, and therefore weight change, will be complicated. In changing energy intake, exercise will impact on the biological mechanisms controlling appetite. It is becoming recognized that the major influences on the expression of appetite arise from fat-free mass and fat mass, resting metabolic rate, gastric adjustment to ingested food, changes in episodic peptides including insulin, ghrelin, cholecystokinin, glucagon-like peptide-1 and tyrosine-tyrosine, as well as tonic peptides such as leptin. Moreover, there is evidence that exercise will influence all of these components that, in turn, will influence the drive to eat through the modulation of hunger (a conscious sensation reflecting a mental urge to eat) and adjustments in postprandial satiety via an interaction with food composition. The specific actions of exercise on each physiological component will vary in strength from

  1. Carbon and energy balances for a range of biofuels options

    Energy Technology Data Exchange (ETDEWEB)

    Elsayed, M.A.; Matthews, R.; Mortimer, N.D.

    2003-03-01

    This is the final report of a project to produce a set of baseline energy and carbon balances for a range of electricity, heat and transport fuel production systems based on biomass feedstocks. A list of 18 important biofuel technologies in the UK was selected for study of their energy and carbon balances in a consistent approach. Existing studies on these biofuel options were reviewed and their main features identified in terms of energy input, greenhouse gas emissions (carbon dioxide, methane, nitrous oxide and total), transparency and relevance. Flow charts were produced to represent the key stages of the production of biomass and its conversion to biofuels. Outputs from the study included primary energy input per delivered energy output, carbon dioxide outputs per delivered energy output, methane output per delivered energy output, nitrous oxide output per delivered energy output and total greenhouse gas requirements. The net calorific value of the biofuel is given where relevant. Biofuels studied included: biodiesel from oilseed rape and recycled vegetable oil; combined heat and power (CHP) by combustion of wood chip from forestry residues; CHP by gasification of wood chip from short rotation coppice; electricity from the combustion of miscanthus, straw, wood chip from forestry residues and wood chip from short rotation coppice; electricity from gasification of wood chip from forestry residues and wood chip from short rotation coppice; electricity by pyrolysis of wood chip from forestry residues and wood chip from short rotation coppice; ethanol from lignocellulosics, sugar beet and wheat; heat (small scale) from combustion of wood chip from forestry residues and wood chip from short rotation coppice; and rapeseed oil from oilseed rape.

  2. [Energy balance, body composition and the female athlete triad syndrome].

    Science.gov (United States)

    Weinstein, Yitzhak; Weinstein, Ayelet

    2012-02-01

    With the rising participation of women in sports events, the prevalence of eating disorders and the female athlete triad (FTS), a syndrome of disordered eating, amenorrhea, and osteoporosis, have also increased in recent years. FTS is often seen in sports that emphasize thinness (e.g. gymnastics, figure skating and dancing) and also in endurance events. Elements of the FTS are pathophysiologically linked, leading to several disease risks and even to mortality. In spite of the considerable knowledge about sports nutrition, there is no consensus as to the correct nutrition regime for the female athlete. There is consensus that minimizing fluctuations in 'target-body-weight' is an indication of a long-term energy balance. Female athletes (e.g. in endurance events and gymnastics) are less likely to achieve the recommended carbohydrates (CHO) and fat consumption due to chronic or episodic constraints of total energy intake while struggling to achieve or maintain low levels of body fat. It is recommended that dietary CHO and fat content be increased to preserve fat-free mass thus enhancing health and performance. Energy balance should also be maintained during recesses. Furthermore, within-day episodes of energy deficits/surplus (measured by the frequency and/or magnitude of the episodes) should be monitored and treated closest to the time of the incidents.

  3. The energy balance of plasmoids in the solar atmosphere

    Science.gov (United States)

    Cargill, P. J.; Pneuman, G. W.

    1986-01-01

    The properties of an isolated magnetized plasmoid in a nonuniform magnetic field such as arises in stellar atmospheres are studied. The work of Pneuman and Cargill (1985) on the so-called melon-seed effect is extended to include an equation describing the energy balance, so giving a unified picture of the shape, motion, and energetics of the plasmoid. Three treatments of plasmoid energy balance are considered: (1) a polytropic law, (P = about N to the gamma); (2) one in which the plasmoid cools radiatively; and (3) one in which a heating function proportional to the local density balances the radiation. For a gamma = 4/3 polytrope the evolution is self-similar, so that the plasmoid maintains its shape as it moves out from the stellar surface. If gamma is less than 4/3, the final shape is a long thin cigar-shaped body, whereas if gamma is greater than or equal to 4/3, it ultimately becomes self-similar. In cases with radiation and also with heating, the ultimate shape of the plasmoid is determined by whether its gas or magnetic pressure dominate. The former is equivalent to the gamma-less-than-4/3 polytrope, and the latter to the gamma-greater-than-4/3 one. If radiation alone is present, the plasmoid cools rapidly and subsequently evolves self-similarly. If heating balances radiation initially, then the plasmoid heats up as it moves out, but, if the ratio of the transit of time of Alfven waves across it is much less than the radiative cooling time, it ultimately evolves as a gamma = 5/3 polytrope. In each case the plasmoid can be ejected to large distances (several radii) in a stellar atmosphere, for a reasonable choice of surface parameters.

  4. Essential role of UCP1 modulating the central effects of thyroid hormones on energy balance

    Directory of Open Access Journals (Sweden)

    Mayte Alvarez-Crespo

    2016-04-01

    Conclusions: We conclude that UCP1 is essential for mediation of the central effects of thyroid hormones on energy balance, and we suggest that similar UCP1-dependent effects may underlie central energy balance effects of other agents.

  5. Surface energy balance measurements in the Mexico City: a review

    Energy Technology Data Exchange (ETDEWEB)

    Tejeda Martinez, A. [Universidad Veracruzana, Xalapa, Veracruz (Mexico); Jauregui Ostos, E. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, UNAM, Mexico, D.F. (Mexico)

    2005-01-01

    During the last decade of the 20th Century, diverse campaigns for measuring the atmospheric energy balance were performed in downtown Mexico City (School of Mines and Preparatory School No. 7), in the southern suburbs (University Reserve) and in the surrounding rural areas (Plan Texcoco), in addition to a campaign carried out in 1985 in the Tacubaya district, a suburban western peripheral site. The objective was to obtain data for a better understanding of the climatic alterations due to urbanization, particularly to describe the role that the modification of the natural ground cover has played as a result of paving and the construction of urban canyons. In this paper, a review of these campaigns is presented. Energy partitioning in some areas (Tacubaya and Preparatory School No.7) is similar to that observed in urban centers of middle latitudes, whereas the major contrast was observed between Texcoco, with maximum energy consumption through evaporation, and School of Mines, where the latent heat is as low as in a desert. From the values of the correlations among the different components of energy balance, it may be possible to attempt the modeling of the diverse components of energy balance by means of regression equations starting from the net radiation. Those same coefficients distinguish the type of environment: urban, suburban or rural. [Spanish] Las primeras mediciones de balance energetico en la Ciudad de Mexico se realizaron en 1985 en un suburbio al poniente de la ciudad (el observatorio de Tacubaya). Ya en la decada de los anos noventa del siglo XX, dichas observaciones se multiplicaron tanto en el centro historico (antigua Escuela de Minas y en el edificio de la Preparatoria No. 7), como en otros sitios al sur (en terrenos de Ciudad Universitaria) y en la periferia rural (Plan Texcoco). El proposito de estas mediciones ha sido tener un mejor entendimiento de las alteraciones climaticas debidas a la urbanizacion. En este trabajo se presenta una revision

  6. Primary cilia in energy balance signaling and metabolic disorder.

    Science.gov (United States)

    Lee, Hankyu; Song, Jieun; Jung, Joo Hyun; Ko, Hyuk Wan

    2015-12-01

    Energy homeostasis in our body system is maintained by balancing the intake and expenditure of energy. Excessive accumulation of fat by disrupting the balance system causes overweight and obesity, which are increasingly becoming global health concerns. Understanding the pathogenesis of obesity focused on studying the genes related to familial types of obesity. Recently, a rare human genetic disorder, ciliopathy, links the role for genes regulating structure and function of a cellular organelle, the primary cilium, to metabolic disorder, obesity and type II diabetes. Primary cilia are microtubule based hair-like membranous structures, lacking motility and functions such as sensing the environmental cues, and transducing extracellular signals within the cells. Interestingly, the subclass of ciliopathies, such as Bardet-Biedle and Alström syndrome, manifest obesity and type II diabetes in human and mouse model systems. Moreover, studies on genetic mouse model system indicate that more ciliary genes affect energy homeostasis through multiple regulatory steps such as central and peripheral actions of leptin and insulin. In this review, we discuss the latest findings in primary cilia and metabolic disorders, and propose the possible interaction between primary cilia and the leptin and insulin signal pathways which might enhance our understanding of the unambiguous link of a cell's antenna to obesity and type II diabetes.

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

    Science.gov (United States)

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

    2009-11-01

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

  8. Reproduction and energy balance: the integrative role of prolactin

    Directory of Open Access Journals (Sweden)

    T I Romantsova

    2014-03-01

    Full Text Available The physiological mechanisms controlling reproduction are closely linked to energy balance. In the recent years, accumulating evidence suggests that prolactin regulates metabolic functions, besides regulating breast development and stimulating milk formation. Hyperprolactinemia is associated with obesity and treatment with dopamine agonists results in weight loss. We discuss the integrated effects of prolactin in the metabolic control and reproductive function, the role of prolactin in the pathogenesis of obesity. The present review also describes the effects of treatment with cabergoline on body weight and cardiovascular risk markers.

  9. The Precession Index and a Nonlinear Energy Balance Climate Model

    Science.gov (United States)

    Rubincam, David

    2004-01-01

    A simple nonlinear energy balance climate model yields a precession index-like term in the temperature. Despite its importance in the geologic record, the precession index e sin (Omega)S, where e is the Earth's orbital eccentricity and (Omega)S is the Sun's perigee in the geocentric frame, is not present in the insolation at the top of the atmosphere. Hence there is no one-for-one mapping of 23,000 and 19,000 year periodicities from the insolation to the paleoclimate record; a nonlinear climate model is needed to produce these long periods. A nonlinear energy balance climate model with radiative terms of form T n, where T is surface temperature and n less than 1, does produce e sin (omega)S terms in temperature; the e sin (omega)S terms are called Seversmith psychroterms. Without feedback mechanisms, the model achieves extreme values of 0.64 K at the maximum orbital eccentricity of 0.06, cooling one hemisphere while simultaneously warming the other; the hemisphere over which perihelion occurs is the cooler. In other words, the nonlinear energy balance model produces long-term cooling in the northern hemisphere when the Sun's perihelion is near northern summer solstice and long-term warming in the northern hemisphere when the aphelion is near northern summer solstice. (This behavior is similar to the inertialess gray body which radiates like T 4, but the amplitude is much lower for the energy balance model because of its thermal inertia.) This seemingly paradoxical behavior works against the standard Milankovitch model, which requires cool northern summers (Sun far from Earth in northern summer) to build up northern ice sheets, so that if the standard model is correct it must be more efficient than previously thought. Alternatively, the new mechanism could possibly be dominant and indicate southern hemisphere control of the northern ice sheets, wherein the southern oceans undergo a long-term cooling when the Sun is far from the Earth during northern summer. The cold

  10. Arctic melt ponds and energy balance in the climate system

    Science.gov (United States)

    Sudakov, Ivan

    2017-02-01

    Elements of Earth's cryosphere, such as the summer Arctic sea ice pack, are melting at precipitous rates that have far outpaced the projections of large scale climate models. Understanding key processes, such as the evolution of melt ponds that form atop Arctic sea ice and control its optical properties, is crucial to improving climate projections. These types of critical phenomena in the cryosphere are of increasing interest as the climate system warms, and are crucial for predicting its stability. In this paper, we consider how geometrical properties of melt ponds can influence ice-albedo feedback and how it can influence the equilibria in the energy balance of the planet.

  11. Energy Balance Sheet of a Semi Operational Thermic System

    Directory of Open Access Journals (Sweden)

    Honus Stanislav

    2014-09-01

    Full Text Available The article is focused onthe energetical balance of a technical system for the conversion of crushed tyres by pyrolysis. Process temperatures were set in the range from 500 to 650°C. Mass input of the material was 30 kg per hour. The aim of the article is to answer the following questions as regards the individual products: Under which process conditions can the highest quality of the individual products related to energy be reached? How does the thermal efficiency of the system change in reaction to various conditions of the process?

  12. BALANCE

    Science.gov (United States)

    Carmichael, H.

    1953-01-01

    A torsional-type analytical balance designed to arrive at its equilibrium point more quickly than previous balances is described. In order to prevent external heat sources creating air currents inside the balance casing that would reiard the attainment of equilibrium conditions, a relatively thick casing shaped as an inverted U is placed over the load support arms and the balance beam. This casing is of a metal of good thernnal conductivity characteristics, such as copper or aluminum, in order that heat applied to one portion of the balance is quickly conducted to all other sensitive areas, thus effectively preventing the fornnation of air currents caused by unequal heating of the balance.

  13. The mass balance of the Greenland ice sheet: sensitivity to climate change as revealed by energy-balance modelling

    NARCIS (Netherlands)

    Oerlemans, J.

    1991-01-01

    The sensitivity of the mass balance of the Greenland ice sheet to climate change is studied with an energy-balance model of the ice/snow surface, applied at 200 m elevation intervals for four characteristic regions of the ice sheet. Solar radiation, longwave radiation, turbulent heat fluxes and refr

  14. Acute effects of capsaicin on energy expenditure and fat oxidation in negative energy balance.

    Directory of Open Access Journals (Sweden)

    Pilou L H R Janssens

    Full Text Available BACKGROUND: Addition of capsaicin (CAPS to the diet has been shown to increase energy expenditure; therefore capsaicin is an interesting target for anti-obesity therapy. AIM: We investigated the 24 h effects of CAPS on energy expenditure, substrate oxidation and blood pressure during 25% negative energy balance. METHODS: Subjects underwent four 36 h sessions in a respiration chamber for measurements of energy expenditure, substrate oxidation and blood pressure. They received 100% or 75% of their daily energy requirements in the conditions '100%CAPS', '100%Control', '75%CAPS' and '75%Control'. CAPS was given at a dose of 2.56 mg (1.03 g of red chili pepper, 39,050 Scoville heat units (SHU with every meal. RESULTS: An induced negative energy balance of 25% was effectively a 20.5% negative energy balance due to adapting mechanisms. Diet-induced thermogenesis (DIT and resting energy expenditure (REE at 75%CAPS did not differ from DIT and REE at 100%Control, while at 75%Control these tended to be or were lower than at 100%Control (p = 0.05 and p = 0.02 respectively. Sleeping metabolic rate (SMR at 75%CAPS did not differ from SMR at 100%CAPS, while SMR at 75%Control was lower than at 100%CAPS (p = 0.04. Fat oxidation at 75%CAPS was higher than at 100%Control (p = 0.03, while with 75%Control it did not differ from 100%Control. Respiratory quotient (RQ was more decreased at 75%CAPS (p = 0.04 than at 75%Control (p = 0.05 when compared with 100%Control. Blood pressure did not differ between the four conditions. CONCLUSION: In an effectively 20.5% negative energy balance, consumption of 2.56 mg capsaicin per meal supports negative energy balance by counteracting the unfavorable negative energy balance effect of decrease in components of energy expenditure. Moreover, consumption of 2.56 mg capsaicin per meal promotes fat oxidation in negative energy balance and does not increase blood pressure significantly. TRIAL REGISTRATION

  15. Energy balance of forage consumption by phyllophagous insects: optimization model

    Directory of Open Access Journals (Sweden)

    O. V. Tarasova

    2015-06-01

    Full Text Available The model of optimal food consumption by phytophagous insects proposed, in which the metabolic costs are presented in the form of two components – the cost of food utilization and costs for proper metabolism of the individuals. Two measures were introduced – the «price» of food conversion and the «price» of biomass synthesis of individuals to assess the effectiveness of food consumption by caterpillars. The proposed approach to the description of food consumption by insects provides the exact solutions of the equation of energy balance of food consumption and determining the effectiveness of consumption and the risk of death of the individual. Experiments on larvae’s feeding in laboratory conditions were carried out to verify the model. Caterpillars of Aporia crataegi L. (Lepidoptera, Pieridae were the research subjects. Supply­demand balance, calculated value of the environmental price of consumption and efficiency of food consumption for each individual were determined from experimental data. It was found that the fertility of the female does not depend on the weight of food consumed by it, but is linearly dependent on the food consumption efficiency index. The greater the efficiency of food consumption by an individual, the higher its fertility. The data obtained in the course of experiments on the feeding caterpillars Aporia crataegi were compared with the data presented in the works of other authors and counted in the proposed model of consumption. Calculations allowed estimation of the critical value of food conversion price below which the energy balance is negative and the existence of an individual is not possible.

  16. Energy balance regulation by endocannabinoids at central and peripheral levels.

    Science.gov (United States)

    Quarta, Carmelo; Mazza, Roberta; Obici, Silvana; Pasquali, Renato; Pagotto, Uberto

    2011-09-01

    Dysregulation of the endocannabinoid system (ECS) is a universal and, perhaps, causative feature of obesity. Central nervous system (CNS) circuits that regulate food intake were initially believed to be the targets for dysregulation. However, it is increasingly evident that endocannabinoids affect food intake, energy expenditure and substrate metabolism by acting on peripheral sites. Cannabinoid type 1 receptor (CB1r) antagonists can effectively treat obesity and associated metabolic alterations but, unfortunately, cause and exacerbate mood disorders. Drugs restricted to act on peripheral CB1rs might be safer and more effective, retaining the anti-obesity effects but lacking the adverse neurodepressive reactions. This review summarizes the emerging roles of the ECS in energy balance and discusses future pharmacological approaches for developing peripherally restricted CB1r antagonists.

  17. Biodiesel from microalgae – greenhouse gas emissions and energy balance

    DEFF Research Database (Denmark)

    Monari, Chiara; Righi, Serena; Olsen, Stig Irving

    of algal biodiesel from Nannochloropsis cultivated at industrial scale in photobioreactors in Denmark. Both consolidated and pioneering technologies are analyzed focusing on strengths and weaknesses which influence the performance. Based on literature data, energy balance and greenhouse gas emissions...... are determined in a comparative ‘well-to-tank’ Life Cycle Assessment against fossil diesel. Use of by-products from biodiesel production such as glycerol obtained from transesterification and anaerobic digestion of residual biomass are included. Different technologies and methods are considered in cultivation...... biodiesel produced through current conventional technologies has higher energy demand and greenhouse gas emissions than fossil diesel. However, greenhouse gas emissions of algal biodiesel can be significantly reduced through the use of ‘waste’ flows (nutrients and CO2) but there are still technical...

  18. Heparanase affects food intake and regulates energy balance in mice.

    Directory of Open Access Journals (Sweden)

    Linda Karlsson-Lindahl

    Full Text Available Mutation of the melanocortin-receptor 4 (MC4R is the most frequent cause of severe obesity in humans. Binding of agouti-related peptide (AgRP to MC4R involves the co-receptor syndecan-3, a heparan sulfate proteoglycan. The proteoglycan can be structurally modified by the enzyme heparanase. Here we tested the hypothesis that heparanase plays a role in food intake behaviour and energy balance regulation by analysing body weight, body composition and food intake in genetically modified mice that either lack or overexpress heparanase. We also assessed food intake and body weight following acute central intracerebroventricular administration of heparanase; such treatment reduced food intake in wildtype mice, an effect that was abolished in mice lacking MC4R. By contrast, heparanase knockout mice on a high-fat diet showed increased food intake and maturity-onset obesity, with up to a 40% increase in body fat. Mice overexpressing heparanase displayed essentially the opposite phenotypes, with a reduced fat mass. These results implicate heparanase in energy balance control via the central melanocortin system. Our data indicate that heparanase acts as a negative modulator of AgRP signaling at MC4R, through cleavage of heparan sulfate chains presumably linked to syndecan-3.

  19. CHAMP gravity field recovery using the energy balance approach

    Directory of Open Access Journals (Sweden)

    Ch. Gerlach

    2003-01-01

    Full Text Available Since the early days of satellite geodesy energy balance based methods for gravity field determination have been considered. If non-conservative forces are known the Hamiltonian along the orbit is a constant of the motion. Thus the gravity field can be determined if position and velocity of the satellite are known and accelerometer measurements are available to model the non-conservative part. CHAMP is the first satellite that provides the user with those three kinds of data nearly continuously. Numerical investigations using real CHAMP data are presented to show the feasibility of the method. Using a semi-analytical approach the gravity field can be determined efficiently by a 2D-Fourier method. Those fast computations also give way to application of the method not only to a full gravity field recovery but also, e.g. for quick-look and validation of SST observations for satellite missions like CHAMP, GRACE or GOCE. The method can also be used for estimation of accelerometer calibration parameters.Key words. gravity field, energy balance, Jacobi-integral, non-conservative forces, accelerometer calibration, CHAMP

  20. [Diurnal and seasonal variations of energy balance over Horqin meadow].

    Science.gov (United States)

    Li, Hui-dong; Guan, De-Xin; Yuan, Feng-Hui; Ren, Yan; Wang, An-Zhi; Jin, Chang-Jie; Wu, Jia-Bing

    2014-01-01

    Based on the measurements of eddy flux and micrometeorological factors, this paper analyzed the diurnal and seasonal variations of energy balance over Horqin meadow. The results showed that annual energy balance ratio (EBR) of the eddy covariance system was 0.77, and EBR was biggest in growing season, middle in bare soil period and smallest in snow-covered period. Diurnal variations of energy components all presented bell-shaped curves. The peak of net radiation appeared around 12:00 and peaks of other components slightly lagged. Seasonal variation of net radiation presented a single-peak curve, and the annual average was 5.71 MJ x m(-2) x d(-1). Seasonal variation of latent heat flux was similar to that of net radiation, and the annual average was 2.84 MJ x m(-2) x d(-1). Seasonal variation of sensible heat flux presented a double-peak curve, and the peaks appeared in April and September, respectively. Annual averaged sensible heat flux was 1.87 MJ x m(-2) x d(-1). Maximum soil heat flux (3.47 MJ x m(-2) x d(-1)) appeared in April, and the soil heat flux became negative after September. Annual budget ratios of energy components presented a decreasing order of latent heat flux, sensible heat flux and soil heat flux, which accounted for 49.8%, 35.8% and 3.1% of net radiation, respectively. Seasonal variation of Bowen ratio (beta) presented a 'U' shape, and the annual average was 1.61. beta was small (0.18) and relatively stable in growing season, while it was large (2.39) and fluctuated severely in non-growing season.

  1. Flow effects on jet energy loss with detailed balance

    Institute of Scientific and Technical Information of China (English)

    CHENG Luan; LIU Jia; WANG EnKe

    2014-01-01

    In the presence of collective flow a new model potential describing the interaction of the hard jet with scattering centers is derived based on the static color-screened Yukawa potential.The flow effect on jet quenching with detailed balance is investigated in pQCD.It turns out,considering the collective flow with velocity vz along the jet direction,the collective flow decreases the LPM destructive interference comparing to that in the static medium.The gluon absorption plays a more important role in the moving medium.The collective flow increases the energy gain from gluon absorption,however,decreases the energy loss from gluon radiation,which is (1-vz) times as that in the static medium to the first order of opacity.In the presence of collective flow,the second order in opacity correction is relatively small compared to the first order.So that the total effective energy loss is decreased.The flow dependence of the energy loss will affect the suppression of high PT hadron spectrum and anisotropy parameter v2 in high-energy heavy-ion collisions.

  2. Mechanisms linking energy balance and reproduction: impact of prenatal environment.

    Science.gov (United States)

    Rhinehart, Erin M

    2016-01-01

    The burgeoning field of metabolic reproduction regulation has been gaining momentum due to highly frequent discoveries of new neuroendocrine factors regulating both energy balance and reproduction. Universally throughout the animal kingdom, energy deficits inhibit the reproductive axis, which demonstrates that reproduction is acutely sensitive to fuel availability. Entrainment of reproductive efforts with energy availability is especially critical for females because they expend large amounts of energy on gestation and lactation. Research has identified an assortment of both central and peripheral factors involved in the metabolic regulation of reproduction. From an evolutionary perspective, these mechanisms likely evolved to optimize reproductive fitness in an environment with an unpredictable food supply and regular bouts of famine. To be effective, however, the mechanisms responsible for the metabolic regulation of reproduction must also retain developmental plasticity to allow organisms to adapt their reproductive strategies to their particular niche. In particular, the prenatal environment has emerged as a critical developmental window for programming the mechanisms responsible for the metabolic control of reproduction. This review will discuss the current knowledge about hormonal and molecular mechanisms that entrain reproduction with prevailing energy availability. In addition, it will provide an evolutionary, human life-history framework to assist in the interpretation of findings on gestational programming of the female reproductive function, with a focus on pubertal timing as an example. Future research should aim to shed light on mechanisms underlying the prenatal modulation of the adaptation to an environment with unstable resources in a way that optimizes reproductive fitness.

  3. Energy Storage System Based on Cascaded Multilevel Inverter with Decoupled Energy Balancing Control

    Directory of Open Access Journals (Sweden)

    Cao Yuanzhi

    2015-01-01

    Full Text Available This paper presents a three phase cascaded multilevel inverter based supercapacitor (SC energy storage system with novel structure and control strategy to maintain the energy balance of between phases. Every two phases are coupled with a series LC filter. With the filter, SC cells in different phases could exchange energy with an auxiliary power flow at high frequency. The auxiliary power flow is orthogonal to the primary power flow. The phase difference between high frequency voltage and current components of each phase determines whether the energy is absorbed into or released from its SC cells. Unlike traditional energy balancing strategies, the proposed method is independent to the fundamental real power drawn by the energy storage system. Simulation results confirmed the effects of proposed theories.

  4. Global Energy and Water Balances in the Latest Reanalyses

    Science.gov (United States)

    Ahn, Joong-Bae; Kang, Suchul; Park, Hye-Jin

    2016-04-01

    The recently released Japanese 55-year Reanalysis (JRA-55) data are evaluated and compared with three other global reanalyses, namely Interim version of the next European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERRA-Interim), Modern Era Retrospective-Analysis for Research and Applications (MERRA) and Climate Forecast System Reanalysis (CFSR), in terms of global energy and water balances. All four reanalyses show an energy imbalance at TOA and surface. Especially, clouds in JRA-55 are optically weaker than those in the three other reanalyses, leading to excessive outgoing longwave radiation, which in turn causes negative net energy flux at TOA. Moreover, JRA-55 has a negative imbalance at surface and at TOA, which is attributed to systematic positive biases in latent heat flux over the ocean. As for the global water balance, all reanalyses present a similar spatial pattern of the difference between evaporation and precipitation (E-P). However, JRA-55 has a relatively strong negative (positive) E-P in the Intertropical Convergence Zone and South Pacific Convergence Zone (extratropical regions) due to overestimated precipitation (evaporation), in spite of the global net being close to zero. In time series analysis, especially in E-P, significant stepwise changes occur in MERRA, CFSR and ERA-Interim due to the changes occur in MERRA, CFRS and ERA-Interim due to the changes in the satellite observing system used in the data assimilation. Both MERRA and CFSR show a strong downward E-P shift in 1998, simultaneously with the start of the assimilation of AMSU-A sounding radiances. ERA-Interim exhibits an upward E-P shift in 1992 due to changes in observations from the SSM/I of new DMSP satellites. On the contrary, JRA-55 exhibits less trends and remains stable over time, which may be caused by newly available, homogenized observations and advances in data assimilation technique. Acknowledgements This work was funded by the Korea Meteorological

  5. Preliminary approach of the MELiSSA loop energy balance

    Science.gov (United States)

    Poulet, Lucie; Lamaze, Brigitte; Lebrun, Jean

    Long duration missions, such as the establishment of permanent bases on the lunar surface or the travel to Mars, require a huge amount of life support consumables (e.g. food, water and oxygen). Current rockets are at the moment unable to launch such a mass from Earth. Consequently Regenerative Life Support Systems are necessary to sustain long-term manned space mission to increase recycling rates and so reduce the launched mass. Thus the European and Canadian research has been concentrating on the MELiSSA (Micro-Ecological Life Support System Alternative) project over the last 20 years. MELiSSA is an Environmental Controlled Life Support System (ECLSS), i.e. a closed regenerative loop inspired of a lake ecosystem. Using light as a source of energy, MELiSSA's goal is the recovery of food, water and oxygen from CO2 and organic wastes, using microorganisms and higher plants. The architecture of a ECLSS depends widely on the mission scenario. To compare several ECLSS architectures and in order to be able to evaluate them, ESA is developing a multi criteria evaluation tool: ALISSE (Advanced LIfe Support System Evaluator). One of these criteria is the energy needed to operate the ECLSS. Unlike other criteria like the physical mass, the energy criterion has not been investigated yet and needs hence a detailed analysis. It will consequently be the focus of this study. The main objective of the work presented here is to develop a dynamic tool able to estimate the energy balance for several configurations of the MELiSSA loop. The first step consists in establishing the energy balance using concrete figures from the MELiSSA Pilot Plant (MPP). This facility located at the Universitat Autonoma de Barcelona (UAB) is aimed at the ground demonstration of the MELiSSA loop. The MELiSSA loop is structured on several subsystems; each of them is characterized by supplies, exhausts and process reactions. For the purpose of this study (i.e. a generic tool) the solver EES (Engineering

  6. SURFACE ENERGY BALANCE OVER ORANGE ORCHARD USING SURFACE RENEWAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Salvatore Barbagallo

    2009-12-01

    Full Text Available Reliable estimation of surface sensible and latent heat flux is the most important process to appraise energy and mass exchange among atmosphere and biosphere. In this study the surface energy fluxes were measured over an irrigated orange orchard during 2005-2008 monitoring periods using a Surface Renewal- Energy Balance approach. The experimental area is located in a representative orchard growing area of eastern Sicily (Italy. The performance of Surface Renewal (SR analysis for estimating sensible heat flux (H was analysed and evaluated in terms of correlation with H fluxes from the eddy covariance (EC method. Study revealed that the mean available energy (RN- G and latent heat flux (LE were of about 300 W m-2 and 237 W m-2, respectively, during dry periods and unstable-case atmospheric conditions. The estimated crop coefficient Kc values for the orchard crop averaged close to 0.80, which is considerably higher than previous FAO studies that found the value to be 0.65 for citrus with 70% of ground cover. The intercepted photosynthetically active radiation (LI PAR by the crop was measured and relationships between LAI and crop coefficient (Kc were established.

  7. Energy balance during two days of continuous stationary cycling

    Directory of Open Access Journals (Sweden)

    Stewart Kelly L

    2007-10-01

    Full Text Available Abstract This study examined the capabilities of an ultraendurance athlete to self-regulate their diet during an attempt on the record for the longest period of stationary cycling. The attempt required the athlete to complete at least 20 km/hr, with a 15 minute break allowed every eight hours. Laboratory tests determined a heart rate-oxygen consumption regression equation enabling calculation of energy expenditure from heart rate during the attempt. Energy intake was determined by a non-weighed dietary record collected at the time of consumption. The athlete completed 46.7 hours, covering 1126 km, at a speed of 24 ± 1.6 km/hr. He expended 14486 kcal and consumed 11098 kcal resulting in an energy deficit (-3290 kcal and a weight loss (-0.55 kg. The carbohydrate (42 ± 32 g/hr, water (422 ± 441 ml/hr, and sodium (306 ± 465 mg/hr intake were all below current recommendations. The athlete was unable to self-regulate his diet or exercise intensity to prevent a negative energy balance.

  8. The global land and ocean mean energy balance

    Science.gov (United States)

    Wild, Martin; Folini, Doris

    2016-04-01

    The energy balance over land and oceans governs a diversity of terrestrial and maritime processes and is the key determinant of climatic conditions in these areas. Despite its crucial role, climate models show significant differences in the individual components of the energy balance over both land and oceans, particularly at the surface. Here we combine a comprehensive set of radiation observations from GEBA and BSRN with 43 state-of-the-art climate models to infer best estimates for present day annual mean downward solar and thermal radiation averaged over land and ocean surfaces, together with their uncertainty ranges. Over land (including the polar ice sheets), where most direct observations are available to constrain the surface fluxes, we obtain 184 and 306 Wm-2 for solar and thermal downward radiation, respectively. Over oceans, with weaker observational constraints, corresponding estimates are around 185 and 356 Wm-2. These values closely agree, mostly within 3 Wm-2, with the respective quantities independently derived by a state-of-the-art reanalysis (ERA-Interim) and satellite-derived product (surface CERES EBAF). This remarkable consistency enhances confidence in the determined flux magnitudes, which so far stated large uncertainty sources in the energy budgets. The estimated downward solar radiation averaged over land and ocean surfaces is almost identical despite differences in the incoming solar flux at the Top-of-Atmosphere (TOA) around 20 Wm-2, indicative of an overall less transparent atmosphere over oceans than land. Considering additionally surface albedo and emissivity, we infer a surface absorbed solar and net thermal radiation of 136 and -66 Wm-2 over land, and 170 and -53 Wm-2 over oceans, respectively. The surface net radiation is thus estimated at 70 Wm-2 over land and 117 Wm-2 over oceans, which may impose additional constraints on the poorly known sensible and latent heat flux magnitudes. These are estimated here near 32 and 38 Wm-2 over

  9. Energy Balance of Triathletes during an Ultra-Endurance Event

    Directory of Open Access Journals (Sweden)

    Anna Barrero

    2014-12-01

    Full Text Available The nutritional strategy during an ultra-endurance triathlon (UET is one of the main concerns of athletes competing in such events. The purpose of this study is to provide a proper characterization of the energy and fluid intake during real competition in male triathletes during a complete UET and to estimate the energy expenditure (EE and the fluid balance through the race. Methods: Eleven triathletes performed a UET. All food and drinks ingested during the race were weighed and recorded in order to assess the energy intake (EI during the race. The EE was estimated from heart rate (HR recordings during the race, using the individual HR-oxygen uptake (Vo2 regressions developed from three incremental tests on the 50-m swimming pool, cycle ergometer, and running treadmill. Additionally, body mass (BM, total body water (TBW and intracellular (ICW and extracellular water (ECW were assessed before and after the race using a multifrequency bioimpedance device (BIA. Results: Mean competition time and HR was 755 ± 69 min and 137 ± 6 beats/min, respectively. Mean EI was 3643 ± 1219 kcal and the estimated EE was 11,009 ± 664 kcal. Consequently, athletes showed an energy deficit of 7365 ± 1286 kcal (66.9% ± 11.7%. BM decreased significantly after the race and significant losses of TBW were found. Such losses were more related to a reduction of extracellular fluids than intracellular fluids. Conclusions: Our results confirm the high energy demands of UET races, which are not compensated by nutrient and fluid intake, resulting in a large energy deficit.

  10. Energy Balance for Random Vibrations of Piecewise-Conservative Systems

    Science.gov (United States)

    IOURTCHENKO, D. V.; DIMENTBERG, M. F.

    2001-12-01

    Vibrations of systems with instantaneous or stepwise energy losses, e.g., due to impacts with imperfect rebounds, dry friction forces(s) (in which case the losses may be treated as instantaneous ones by appropriate introduction of the response energy) and/or active feedback “bang-bang” control of the systems' response are considered. Response of such (non-linear) systems to a white-noise random excitation is considered for the case where there are no other response energy losses. Thus, a simple linear energy growth with time between “jumps” is observed. Explicit expressions for the expected response energy are derived by direct application of the stochastic differential equations calculus, which contains the expected time interval between two consecutive jumps. The latter may be predicted as a solution to the relevant first-passage problem. Perturbational analysis of the relevant PDE for this problem for a certain vibroimpact system demonstrated the possibility for using the solution to the corresponding free vibration problem as a zero order approximation. The method is applied to an s.d.o.f. system with a feedback inertia control, designed according to a certain previously introduced “generalized reversed swings law”. Extensive Monte-Carlo simulation results are presented for this system as well as for several previously analyzed ones: system with impacts; system with dry friction; system with stiffness control; pendulum with controlled length. The results are compared with those due to the asymptotic stochastic averaging approach. Both methods are shown to provide adequate accuracy far beyond the expected applicability range of the asymptotic approach (which requires both excitation intensity and losses to be small), with direct energy balance being generally superior.

  11. Assessing Circumbinary Habitable Zones using Latitudinal Energy Balance Modelling

    CERN Document Server

    Forgan, Duncan

    2013-01-01

    Previous attempts to describe circumbinary habitable zones have been concerned with the spatial extent of the zone, calculated analytically according to the combined radiation field of both stars. By contrast to these "spatial HZs", we present a numerical analysis of the "orbital HZ", a habitable zone defined as a function of planet orbital elements. This orbital HZ is better equipped to handle (for example) eccentric planet orbits, and is more directly connected to the data returned by exoplanet observations. Producing an orbital HZ requires a large number of climate simulations to be run to investigate the parameter space - we achieve this using Latitudinal Energy Balance Models (LEBMs), which handle the insolation of the planet by both stars (including mutual eclipses), as well as the planetary atmosphere's ability to absorb, transfer and lose heat. We present orbital HZs for several known circumbinary planetary systems: Kepler-16, Kepler-34, Kepler-35, Kepler-47 and PH-1. Generally, the orbital HZs at zer...

  12. Energy balance and the origin of Kleiber's law

    CERN Document Server

    Ballesteros, Fernando J; Moya, Andrés; Luque, Bartolo

    2014-01-01

    In 1932, Max Kleiber found that the basal metabolic rate of animals seemed to vary as a power law of their body mass with exponent 3/4, but this law is still a matter of controversy. Although some researchers support that 2/3 should be the correct value for the exponent, most of them accept Kleiber's 3/4 value and justify this choice on the basis of research on fractal structures. However some studies show that it is not a pure power law, introducing more doubts about its origin. Here we show that the origin of Kleiber's law is the balance between the energy lost as heat and the energy efficiently used by the organism to maintain its metabolism. Our model is based on the fact that a fraction of the energy income is not converted into heat and this consideration has a radical effect in the shape of the law. The different slope observed in animals and plants is due to their different surface-to-volume ratio. Compared with previous attempts of explanation, our model is very simple, it is biologically sound and s...

  13. Energy balance analysis for Erdemir blast furnace number one

    Energy Technology Data Exchange (ETDEWEB)

    M. Emre Ertem; Sabit Gurgen [Eregli Iron and Steel Works Inc., Zonguldak (Turkey). Energy Management Department

    2006-08-15

    There are two blast furnaces in Erdemir. The blast furnace No. 1, Ayse, started operations in 1965. Having been modernized three times in the years 1971, 1977, and 1986, it has been re-lined (the renewal of refractory bricks) in the year 1998. The diameter of its reservoir is 8.99 m with a working volume of 1505.0 m{sup 3}. The daily production capacity is 3000 tons amounting to 1,065,000 tons annually tons. The blast furnace No. 2, Zubeyde, started its operations in 1978. It has been modernized twice in the years 1987 and 1995 and has been re-lined in October 2000. It is of top pressure type and has oxygen injection. The diameter of its reservoir is 9.70 m with the working volume being 1707.7 m{sup 3}. The daily production capacity is 4000 tons with the annual being 1,420,000 tons. The iron production process consumes 50% of the total energy and comprises a significant portion of total costs in the integrated steel works. Iron (Fe) production is made by the reduction of hematite (Fe{sub 2}O{sub 3}) and magnetite (Fe{sub 3}O{sub 4}) with coke in the blast furnace. This can be analyzed as two separate areas, namely the furnace and stoves. The necessary carbon and high temperature required by the reduction process makes the furnaces an energy balance center. In this study, the limits of the Blast Furnace No. 1 in Erdemir have been chosen as the control volume in which the stoves have not been included. By the identification of the energy sources that move in and out of the control volume, the energy output sources have been fractioned and categorized. For the implementation of the method, also known as the balance analysis has been chosen and the model presented in the 'Japanese Steel Making Handbook' has been taken as a reference.

  14. Energy balance analysis for Erdemir blast furnace number one

    Energy Technology Data Exchange (ETDEWEB)

    Emre Ertem, M. [Eregli Iron and Steel Works Inc., Energy Management Department, 67330 Kdz. Eregli, Zonguldak (Turkey); Guergen, Sabit [Dokuz Eyluel University, Department of Mining Engineering, 35100 Bornova, Izmir (Turkey)

    2006-08-15

    Eregli Iron and Steel Works (Erdemir) began its activities on May 15, 1965 with an annual production capacity of 450,000 tons and has made important contributions to the Turkish economy ever since. Today, with a total amount of crude steel production exceeding three million tons, it is the largest integrated iron and steel factory and the sole producer of flat steel in the country. Erdemir produces hot and cold rolled coils, zinc, tin, and chromium plated steel. There are two blast furnaces in Erdemir. The blast furnace No. 1, Ayse, started operations in 1965. Having been modernized three times in the years 1971, 1977, and 1986, it has been re-lined (the renewal of refractory bricks) in the year 1998. The diameter of its reservoir is 8.99m with a working volume of 1505.0m{sup 3}. The daily production capacity is 3000 tons amounting to 1,065,000 tons annually tons. The blast furnace No. 2, Zubeyde, started its operations in 1978. It has been modernized twice in the years 1987 and 1995 and has been re-lined in October 2000. It is of top pressure type and has oxygen injection. The diameter of its reservoir is 9.70m with the working volume being 1707.7m{sup 3}. The daily production capacity is 4000 tons with the annual being 1,420,000 tons. The iron production process consumes 50% of the total energy and comprises a significant portion of total costs in the integrated steel works. Iron (Fe) production is made by the reduction of hematite (Fe{sub 2}O{sub 3}) and magnetite (Fe{sub 3}O{sub 4}) with coke in the blast furnace. This can be analyzed as two separate areas, namely the furnace and stoves. The necessary carbon and high temperature required by the reduction process makes the furnaces an energy balance center. In this study, the limits of the Blast Furnace No. 1 in Erdemir have been chosen as the control volume in which the stoves have not been included. By the identification of the energy sources that move in and out of the control volume, the energy output

  15. Fuzzy droop control loops adjustment for stored energy balance in distributed energy storage system

    DEFF Research Database (Denmark)

    Aldana, Nelson Leonardo Diaz; Wu, Dan; Dragicevic, Tomislav;

    2015-01-01

    The study of isolated AC microgrid has been under high interest due to the integration of renewable energy resources especially for remote areas, or to improve the local energy reliability. The current trend is oriented to distributed renewable energy sources and their corresponding energy storage...... system, in order to smooth the variations at the prime energy generator. In this paper, a decentralized strategy based on fuzzy logic is proposed in order to balance the state of charge of distributed energy storage systems in lowvoltage three phase AC microgrid. The proposed method weights the action...... of conventional droop control loops for battery based distributed energy storage systems, in order to equalize their stored energy. The units are selfcontrolled by using local variables, hence, the microgrid can operate without communication systems. Frequency and voltage bus signaling are used in order...

  16. Energy and Greenhouse gas balances of the utilisation of biogas for energy

    DEFF Research Database (Denmark)

    Nielsen, Per Sieverts; Karlsson, Kenneth Bernard; Holm-Nielsen, Jens Bo

    1998-01-01

    The utilisation of biogas for energy is an important part of the Danish energy plan for reducing Danish emissions of greenhouse gases. Implementation programmes for new biogas plants have been in operation since 1990, promoted by the Ministry of Environment and Energy. The focus of the implementa......The utilisation of biogas for energy is an important part of the Danish energy plan for reducing Danish emissions of greenhouse gases. Implementation programmes for new biogas plants have been in operation since 1990, promoted by the Ministry of Environment and Energy. The focus...... biogas for energy. Two different Danish joint biogas plants are evaluated with the aim of determining the role of transportation and co-fermentation on the energy and the balance of greenhouse gases from the biogas fuel cycle....

  17. Brazilian energy balance 1998: calendar year 1997; Balanco energetico nacional 1998: ano base 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in every sector of the Brazilian economy, for the calendar year 1995. It's divided into nine sections, as follows: summary; energy supply and consumption by source; energy consumption by sector; energy foreign trading; transformation center balances ;energy resources and reserves; energy and socio economy; regional parameters; and appendices - installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances.

  18. Brazilian energy balance 1996: calendar year 1995; Balanco energetico nacional 1996: ano base 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    This report shows the energy flows of different primary and secondary sources, from the production to the final consumption in every sector of the Brazilian economy, for the calendar year 1995. It's divided into nine sections, as follows: summary; energy supply and consumption by source; energy consumption by sector; energy foreign trading; transformation center balances ;energy resources and reserves; energy and socio economy; regional parameters; and appendices - installed capacity, international data, general structure of the balance, information processing, conversion units and consolidated energy balances.

  19. Gut microbiota and energy balance: role in obesity.

    Science.gov (United States)

    Blaut, Michael

    2015-08-01

    The microbial community populating the human digestive tract has been linked to the development of obesity, diabetes and liver diseases. Proposed mechanisms on how the gut microbiota could contribute to obesity and metabolic diseases include: (1) improved energy extraction from diet by the conversion of dietary fibre to SCFA; (2) increased intestinal permeability for bacterial lipopolysaccharides (LPS) in response to the consumption of high-fat diets resulting in an elevated systemic LPS level and low-grade inflammation. Animal studies indicate differences in the physiologic effects of fermentable and non-fermentable dietary fibres as well as differences in long- and short-term effects of fermentable dietary fibre. The human intestinal microbiome is enriched in genes involved in the degradation of indigestible polysaccharides. The extent to which dietary fibres are fermented and in which molar ratio SCFA are formed depends on their physicochemical properties and on the individual microbiome. Acetate and propionate play an important role in lipid and glucose metabolism. Acetate serves as a substrate for de novo lipogenesis in liver, whereas propionate can be utilised for gluconeogenesis. The conversion of fermentable dietary fibre to SCFA provides additional energy to the host which could promote obesity. However, epidemiologic studies indicate that diets rich in fibre rather prevent than promote obesity development. This may be due to the fact that SCFA are also ligands of free fatty acid receptors (FFAR). Activation of FFAR leads to an increased expression and secretion of enteroendocrine hormones such as glucagon-like-peptide 1 or peptide YY which cause satiety. In conclusion, the role of SCFA in host energy balance needs to be re-evaluated.

  20. Scheduling algorithms for saving energy and balancing load

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, Antonios

    2012-08-03

    In this thesis we study problems of scheduling tasks in computing environments. We consider both the modern objective function of minimizing energy consumption, and the classical objective of balancing load across machines. We first investigate offline deadline-based scheduling in the setting of a single variable-speed processor that is equipped with a sleep state. The objective is that of minimizing the total energy consumption. Apart from settling the complexity of the problem by showing its NP-hardness, we provide a lower bound of 2 for general convex power functions, and a particular natural class of schedules called s{sub crit}-schedules. We also present an algorithmic framework for designing good approximation algorithms. For general convex power functions our framework improves the best known approximation-factor from 2 to 4/3. This factor can be reduced even further to 137/117 for a specific well-motivated class of power functions. Furthermore, we give tight bounds to show that our framework returns optimal s{sub crit}-schedules for the two aforementioned power-function classes. We then focus on the multiprocessor setting where each processor has the ability to vary its speed. Job migration is allowed, and we again consider classical deadline-based scheduling with the objective of energy minimization. We first study the offline problem and show that optimal schedules can be computed efficiently in polynomial time for any convex and non-decreasing power function. Our algorithm relies on repeated maximum flow computations. Regarding the online problem and power functions P(s) = s{sup {alpha}}, where s is the processor speed and {alpha} > 1 a constant, we extend the two well-known single-processor algorithms Optimal Available and Average Rate. We prove that Optimal Available is {alpha}{sup {alpha}}-competitive as in the single-processor case. For Average Rate we show a competitive factor of (2{alpha}){sup {alpha}}/2 + 1, i.e., compared to the single

  1. Energy balance for Sachsen-Anhalt 2010; Energiebilanz Sachsen-Anhalt 2010

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-01-15

    The energy balance of Saxony-Anhalt is presented in physical units, in terrajoule and in coal equivalent to show supply, conversion, and consumption of primary and secondary energy sources in the year under report 2010 Energy balance for Sachsen-Anhalt.

  2. The Global Energy Balance Archive (GEBA): A database for the worldwide measured surface energy fluxes

    Science.gov (United States)

    Wild, Martin; Ohmura, Atsumu; Schär, Christoph; Müller, Guido; Hakuba, Maria Z.; Mystakidis, Stefanos; Arsenovic, Pavle; Sanchez-Lorenzo, Arturo

    2017-02-01

    The Global Energy Balance Archive (GEBA) is a database for the worldwide measured energy fluxes at the Earth's surface. GEBA is maintained at ETH Zurich (Switzerland) and has been founded in the 1980s by Prof. Atsumu Ohmura. It has continuously been updated and currently contains around 2500 stations with 500`000 monthly mean entries of various surface energy balance components. Many of the records extend over several decades. The most widely measured quantity available in GEBA is the solar radiation incident at the Earth's surface ("global radiation"). The data sources include, in addition to the World Radiation Data Centre (WRDC) in St. Petersburg, data reports from National Weather Services, data from different research networks (BSRN, ARM, SURFRAD), data published in peer-reviewed publications and data obtained through personal communications. Different quality checks are applied to check for gross errors in the dataset. GEBA is used in various research applications, such as for the quantification of the global energy balance and its spatiotemporal variation, or for the estimation of long-term trends in the surface fluxes, which enabled the detection of multi-decadal variations in surface solar radiation, known as "global dimming" and "brightening". GEBA is further extensively used for the evaluation of climate models and satellite-derived surface flux products. On a more applied level, GEBA provides the basis for engineering applications in the context of solar power generation, water management, agricultural production and tourism. GEBA is publicly accessible over the internet via www.geba.ethz.ch.

  3. Beyond Leptin: Emerging Candidates for the Integration of Metabolic and Reproductive Function during Negative Energy Balance.

    Science.gov (United States)

    True, Cadence; Grove, Kevin L; Smith, M Susan

    2011-01-01

    Reproductive status is tightly coupled to metabolic state in females, and ovarian cycling in mammals is halted when energy output exceeds energy input, a metabolic condition known as negative energy balance. This inhibition of reproductive function during negative energy balance occurs due to suppression of gonadotropin-releasing hormone (GnRH) release in the hypothalamus. The GnRH secretagogue kisspeptin is also inhibited during negative energy balance, indicating that inhibition of reproductive neuroendocrine circuits may occur upstream of GnRH itself. Understanding the metabolic signals responsible for the inhibition of reproductive pathways has been a compelling research focus for many years. A predominant theory in the field is that the status of energy balance is conveyed to reproductive neuroendocrine circuits via the adipocyte hormone leptin. Leptin is stimulatory for GnRH release and lower levels of leptin during negative energy balance are believed to result in decreased stimulatory drive for GnRH cells. However, recent evidence found that restoring leptin to physiological levels did not restore GnRH function in three different models of negative energy balance. This suggests that although leptin may be an important permissive signal for reproductive function as indicated by many years of research, factors other than leptin must critically contribute to negative energy balance-induced reproductive inhibition. This review will focus on emerging candidates for the integration of metabolic status and reproductive function during negative energy balance.

  4. [Energy flux and energy balance closure of intensively managed lei bamboo forest ecosystem].

    Science.gov (United States)

    Chen, Yun-fei; Jiang, Hong; Zhou, Guo-mo; Sun, Cheng; Chen, Jian

    2013-04-01

    By using open-path eddy covariance system and meteorological instruments, an observation was conducted on the sensitive heat flux, latent heat flux, net radiation, soil heat flux, air temperature, ground temperature, and precipitation in a intensively managed Lei bamboo forest ecosystem in 2011, with the diurnal and monthly variations of energy flux as well as the distribution pattern of each energy component analyzed, and the Bowen ratio and energy balance closure calculated. The yearly net radiation of the forest ecosystem was 2928. 92 MJ m-2, and the latent heat flux, sensitive heat flux, and soil heat flux were 1384.90, 927.54, and -28.27 MJ m-2, respectively. Both the daily and the monthly variations of the energy components showed a single peak curve. The sensible and latent heat fluxes were 31.7% and 47.3% of the net radiation, respectively, indicating that latent heat flux was the main form of energy loss. The Bowen ratio followed the "U"-shaped pattern, and fluctuated from 0. 285 to 2. 062, suggesting that soil was a heat source. The yearly energy balance closure of the forest ecosystem was 0. 782, and the monthly average was 0.808.

  5. Proposal for a refinement of the National Energy Balance (BEN) and Useful Energy Balance (BEU); Proposta de refinamento do Balanco Energetico Nacional e do Balanco de Energia Util

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Alvaro Afonso Furtado [Universidade Estadual de Santa Cruz (DCET/UESC), Ilheus, BA (Brazil). Dept. de Ciencias Exatas e Tecnologicas], email: aafleite@uesc.br; Bajay, Sergio Valdir [Universidade Estadual de Campinas (NIPE/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Nucleo Interdisciplinar de Planejamento Energetico], email: bajay@fem.unicamp.br

    2010-07-01

    The need to discuss the reformulation of two important tools for the Brazilian energy planning - the National Energy Balance (BEN) and the Useful Energy Balance (BEU) - was the motivation to carry out the study reported in this paper. The concepts embodied in the BEN were set out in the seventies, while those structuring the BEU were defined in the eighties. Since then, the ways to produce, trade and consume energy underwent important changes in Brazil and the expansion planning of the national energy system requires, nowadays, more detailed information and, in some cases, more reliable data than those currently provided by the two balances. They need, thus, to be refined, and this paper aims to contribute towards this goal. (author)

  6. Surface energy balance closure in an arid region: role of soil and heat flux

    NARCIS (Netherlands)

    Heusinkveld, B.G.; Jacobs, A.F.G.; Holtslag, A.A.M.; Berkowicz, S.M.

    2004-01-01

    The large soil heat fluxes in hot desert regions are very important in energy balance studies. Surface energy balance (SEB) observations, however, reveal that there is an imbalance in Surface flux measurements and that it is difficult to isolate those flux measurements causing the imbalance errors.

  7. Towards a Sustainable Energy Balance: Progressive Efficiency and the Return of Energy Conservation

    Energy Technology Data Exchange (ETDEWEB)

    Diamond, Rick; Harris, Jeff; Diamond, Rick; Iyer, Maithili; Payne, Christopher; Blumstein, Carl; Siderius, Hans-Paul

    2007-08-13

    We argue that a primary focus on energy efficiency may not be sufficient to slow (and ultimately reverse) the growth in total energy consumption and carbon emissions. Instead, policy makers need to return to an earlier emphasis on"conservation," with energy efficiency seen as a means rather than an end in itself. We briefly review the concept of"intensive" versus"extensive" variables (i.e., energy efficiency versus energy consumption), and why attention to both consumption and efficiency is essential for effective policy in a carbon- and oil-constrained world with increasingly brittle energy markets. To start, energy indicators and policy evaluation metrics need to reflect energy consumption as well as efficiency. We introduce the concept of"progressive efficiency," with the expected or required level of efficiency varying as a function of house size, appliance capacity, or more generally, the scale of energy services. We propose introducing progressive efficiency criteria first in consumer information programs (including appliance labeling categories) and then in voluntary rating and recognition programs such as ENERGY STAR. As acceptance grows, the concept could be extended to utility rebates, tax incentives, and ultimately to mandatory codes and standards. For these and other programs, incorporating criteria for consumption as well as efficiency offers a path for energy experts, policy-makers, and the public to begin building consensus on energy policies that recognize the limits of resources and global carrying-capacity. Ultimately, it is both necessary and, we believe, possible to manage energy consumption, not just efficiency in order to achieve a sustainable energy balance. Along the way, we may find it possible to shift expectations away from perpetual growth and toward satisfaction with sufficiency.

  8. Multiple time scale evaluation of the energy balance during the maize growing season, and a new reason for energy imbalance

    Institute of Scientific and Technical Information of China (English)

    GUO JianXia; BIAN LinGen; DAI YongJiu

    2009-01-01

    Energy imbalance is a common problem associated with the measurement of surface energy using the eddy covariance method. In the evaluation of the energy balance, people usually pay more attention to the statistical result that the effective energy (the sum of sensible and latent heat) is systematically lower than the available energy (the difference of net radiation and ground heat flux). However, little attention has been paid to the existence of the reversed situation when the effective energy is larger than the available energy or their contribution to the overall energy closure rate. In this paper, based on the analysis of the energy balance on multiple time scales across the maize growth season, we con clude that the non-synchronization of energy components is the main reason for the existence of the reversed case. By shifting the phase of the effective energy components half an hour ahead, the rates of energy closure over all time scales are improved and dramatically reduce the number of the half-hourly samples when the energy ratio exceeds 1 or is below 0.5. According to the characteristics of the energy distribution and transformation over multiple time scales, latent heat is always the main type of energy cost, and the residual of the energy balance increases with the growth of the maize plant surpassing the sensible heat for seventy days. It is suggested that the heat storage and photosynthetic energy play an important role in the energy balance during the growing period of maize.

  9. The National Energy Strategy: A balanced program?. Proceedings of the nineteenth annual Illinois energy conference

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-31

    The Nineteenth Annual Illinois Energy Conference was held in Chicago, Illinois November 1991. It was organized by the Energy Resources Center, University of Illinois at Chicago with major support provided by the US Environmental Protection Agency, the US Department of Energy, the Illinois Commerce Commission, the Illinois Department of Energy and Natural Resources, and the Citizens Council on Energy Resources. The conference program was developed by a planning committee who drew upon Illinois energy and environmental specialists from the major sectors including energy industries, environmental organizations, research universities, utility companies, federal, state and local government agencies, and public interest groups. The members of the planning committee were brought together for a full-day session where they were asked to assess the political, economic, and social impacts of the proposed National Energy Strategy as it relates to Illinois and the Midwest region. Within this context, the planning committee identified several major issues including: (1) Is the proposed plan a balanced strategy; (2) What are the NES impacts on the transportation sector; (3) What are the opportunities for improved efficiency in the Electric Utility Sector; and (4) What is the role of advanced research and development.

  10. System analysis of a bio-energy plantation: full greenhouse gas balance and energy accounting (POPFULL)

    Science.gov (United States)

    Ceulemans, R.; Janssens, I.; Berhongaray, G.; Broeckx, L.; De Groote, T.; ElKasmioui, O.; Fichot, R.; Njakou Djomo, S.; Verlinden, M.; Zona, D.

    2011-12-01

    In recent year the environmental impact of fossil fuels and their reduced availability are leading to an increasing interest in renewable energy sources, among them bio-energy. However, the cost/benefit in establishing, managing, and using these plantations for energy production should be quantified together with their environmental impact. In this project we are performing a full life cycle analysis (LCA) balance of the most important greenhouse gases (CO2, CH4, N2O, H2O and O3), together with full energy accounting of a short-rotation coppice (SRC) plantation with fast-growing trees. We established the plantation two years ago and we have been monitoring net fluxes of CO2, N2O, CH4, and O3, in combination with biomass pools (incl. soil) and fluxes, and volatile organic carbon (VOCs). This poplar plantation will be monitored for another two years then harvested and transformed into bio-energy. For the energy accounting we are performing a life cycle analysis and energy efficiency assessments over the entire cycle of the plantation until the production of electricity and heat. Here we present an overview of the results from the first two years from the plantation establishment, and some of the projections based on these first results.

  11. An Enhanced Energy Balanced Data Transmission Protocol for Underwater Acoustic Sensor Networks.

    Science.gov (United States)

    Javaid, Nadeem; Shah, Mehreen; Ahmad, Ashfaq; Imran, Muhammad; Khan, Majid Iqbal; Vasilakos, Athanasios V

    2016-01-01

    This paper presents two new energy balanced routing protocols for Underwater Acoustic Sensor Networks (UASNs); Efficient and Balanced Energy consumption Technique (EBET) and Enhanced EBET (EEBET). The first proposed protocol avoids direct transmission over long distance to save sufficient amount of energy consumed in the routing process. The second protocol overcomes the deficiencies in both Balanced Transmission Mechanism (BTM) and EBET techniques. EBET selects relay node on the basis of optimal distance threshold which leads to network lifetime prolongation. The initial energy of each sensor node is divided into energy levels for balanced energy consumption. Selection of high energy level node within transmission range avoids long distance direct data transmission. The EEBET incorporates depth threshold to minimize the number of hops between source node and sink while eradicating backward data transmissions. The EBET technique balances energy consumption within successive ring sectors, while, EEBET balances energy consumption of the entire network. In EEBET, optimum number of energy levels are also calculated to further enhance the network lifetime. Effectiveness of the proposed schemes is validated through simulations where these are compared with two existing routing protocols in terms of network lifetime, transmission loss, and throughput. The simulations are conducted under different network radii and varied number of nodes.

  12. An Enhanced Energy Balanced Data Transmission Protocol for Underwater Acoustic Sensor Networks

    Directory of Open Access Journals (Sweden)

    Nadeem Javaid

    2016-04-01

    Full Text Available This paper presents two new energy balanced routing protocols for Underwater Acoustic Sensor Networks (UASNs; Efficient and Balanced Energy consumption Technique (EBET and Enhanced EBET (EEBET. The first proposed protocol avoids direct transmission over long distance to save sufficient amount of energy consumed in the routing process. The second protocol overcomes the deficiencies in both Balanced Transmission Mechanism (BTM and EBET techniques. EBET selects relay node on the basis of optimal distance threshold which leads to network lifetime prolongation. The initial energy of each sensor node is divided into energy levels for balanced energy consumption. Selection of high energy level node within transmission range avoids long distance direct data transmission. The EEBET incorporates depth threshold to minimize the number of hops between source node and sink while eradicating backward data transmissions. The EBET technique balances energy consumption within successive ring sectors, while, EEBET balances energy consumption of the entire network. In EEBET, optimum number of energy levels are also calculated to further enhance the network lifetime. Effectiveness of the proposed schemes is validated through simulations where these are compared with two existing routing protocols in terms of network lifetime, transmission loss, and throughput. The simulations are conducted under different network radii and varied number of nodes.

  13. European energy balance research to prevent excessive weight gain among youth (ENERGY) project

    DEFF Research Database (Denmark)

    Stralen, Maartje M. van; Velde, Saskia J. te; Singh, Amika S.

    2011-01-01

    to measure and assess outcomes (i.e. height, weight, waist circumference), EBRBs and potential personal, family and school environmental correlates of these behaviours including the social-cultural, physical, political, and economic environmental factors. In addition, a selection of countries conducted......Background: Obesity treatment is by large ineffective long term, and more emphasis on the prevention of excessive weight gain in childhood and adolescence is warranted. To inform energy balance related behaviour (EBRB) change interventions, insight in the potential personal, family and school...

  14. Balancing Area Coordination: Efficiently Integrating Renewable Energy Into the Grid, Greening the Grid

    Energy Technology Data Exchange (ETDEWEB)

    Katz, Jessica; Denholm, Paul; Cochran, Jaquelin

    2015-06-01

    Greening the Grid provides technical assistance to energy system planners, regulators, and grid operators to overcome challenges associated with integrating variable renewable energy into the grid. Coordinating balancing area operation can promote more cost and resource efficient integration of variable renewable energy, such as wind and solar, into power systems. This efficiency is achieved by sharing or coordinating balancing resources and operating reserves across larger geographic boundaries.

  15. The Analysis of the Development Dynamics and Structural Balance of Solar Energy in the World

    Science.gov (United States)

    Brand, A. E.; Chekardovskiy, S. M.; Akulov, K. A.

    2017-01-01

    The paper presents data the analysis of the development dynamics and structural balance of solar energy in the world. In the article presents information about total installed production capacity of solar energy, the world solar energy production capacity distribution and the European Union energy market structure in 2000 and 2015 years.

  16. Research on Energy-saving Technology of Crank Balanced Pumping Unit

    Directory of Open Access Journals (Sweden)

    Feng Ziming

    2013-12-01

    Full Text Available In order to saving energy and emission reduction, a secondary balance technology was used to reform the conventional beam pumping unit. The output torque from the reduction gearbox of conventional beam pumping units is usually characterized by its periodic drastic changes. Based on the idea of "cutting peak and filling valley" and the theory of the Fourier series expansion for torque curve, the second balance device is designed in order to slow down the fluctuations in the torque curve. The second balance device, with the similar balance principle to the crank balance, is connected to the output shaft of the reduction gearbox and can further reduce torque fluctuation rate and peak torque. Field test result of the secondary balance device shows that the Root-Mean-Square (RMS torque is decreased by 22.7% and the energy-saving rate of motor reaches 6.54%.

  17. Inter-comparison of energy balance and hydrological models for land surface energy flux estimation over a whole river catchment

    DEFF Research Database (Denmark)

    Guzinski, R.; Nieto, H.; Stisen, S.

    2015-01-01

    Evapotranspiration (ET) is the main link between the natural water cycle and the land surface energy budget. Therefore water-balance and energy-balance approaches are two of the main methodologies for modelling this process. The water-balance approach is usually implemented as a complex, distribu...... derived with the energy-balance models, satellite based LST or another source) into the hydrological models. How this could be achieved and how to evaluate the improvements, or lack of thereof, is still an open research question.......-balance (TSEB) scheme, against a hydrological model, MIKE SHE, calibrated over the Skjern river catchment in western Denmark. The three models utilize different primary inputs to estimate ET (LST from different satellites in the case of remote sensing models and modelled soil moisture and heat flux in the case...

  18. Effect of dietary energy source on energy balance, production, metabolic disorders and reproduction in lactating dairy cattle

    NARCIS (Netherlands)

    Knegsel, van A.T.M.; Brand, van den H.; Dijkstra, J.; Tamminga, S.; Kemp, B.

    2005-01-01

    The pathway for oxidation of energy involves a balanced oxidation of C2 and C3 compounds. During early lactation in dairy cattle this C2/C3 ratio is out of balance, due to a high availability of lipogenic (C2) products and a low availability of glycogenic (C3) products relative of the C2 and C3 prod

  19. Coherent Structure Patterns Affect Energy Balance Closure: Evidence from Virtual Measurements for a Field Campaign

    Science.gov (United States)

    Zhang, S.; De Roo, F.; Heinze, R.; Eder, F.; Huq, S.; Schmidt, M.; Kalthoff, N.; Mauder, M.

    2015-12-01

    The energy balance closure problem is a well-known issue of eddy-covariance measurements. However, the underlying mechanisms are still under debate. Recent evidence suggests that organized low-frequency motion contributes significantly to the energy balance residual, because the associated transport cannot be captured by a point measurement. In this study, we carry out virtual measurements using a PArallelized Large-Eddy Simulation Model (PALM). In order to represent specific measurement days of the field campaign "High definition clouds and precipitation for advancing climate prediction" (HD(CP)²), which was part of the project "High Definition Clouds and Precipitation for Advancing Climate Prediction"(HOPE) in 2013, the simulations were driven by synoptic-scale COSMO-DE reanalysis data. Planet boundary layer height, the vertical profiles of variance and skewness of vertical wind were analyzed and a comparison with Doppler-lidar observations shows good agreement. Furthermore, simulated energy imbalances were compared with real-world imbalances from two eddy-covariance stations in the model domain. Particularly poor energy balance closure was found for a day with cellular organized structures in the surface layer, while the energy balance closure was better on other days with roll-like structures. This finding might be one explanation why the energy balance closure generally tends to improve with increasing friction velocity, since roll-like structures are typically associated with higher wind speeds. In order to gain insight into the partitioning of the energy balance residual between the sensible and latent heat fluxes, we further employed a control volume method within the numerical simulation. Hence, advection and storage terms were identified as the most important causes for the lack of energy balance closure by the eddy-covariance method. The results of the virtual measurements indicate that the "missing" part of the surface energy mainly comes from the

  20. Energy Crops and their Implications on Soil Carbon Sequestration, Surface Energy and Water Balance

    Science.gov (United States)

    Song, Y.; Barman, R.; Jain, A. K.

    2011-12-01

    The quest to meet growing energy demand with low greenhouse gas emissions has increased attention on the potential of existing and advanced biomass energy crops. Potential energy crops include row crops such as corn, and perennial grasses such as switchgrass. However, a massive expansion of bioenergy crops raises many questions such as: how and where to grow energy crops; and what will be the impacts of growing large scale biofuel crops on the terrestrial hydrological cycle, the surface energy budget, soil carbon sequestration and the concurrent effects on the climate system. An integrated modeling system is being developed with in the framework of a land surface model, the Integrated Science Assessment Model (ISAM), and being applied to address these questions.This framework accounts for the biophysical, physiological and biogeochemical systems governing important processes that regulate crop growth including water, energy and nutrient cycles within the soil-plant-atmosphere system. One row crop (Corn) and two energy crops (Switchgrass and Miscanthus) are studied in current framework. Dynamic phenology processes and parameters for simulating each crop have been developed using observed data from a north to south gradient of field trial sites. This study will specifically focus on the agricultural regions in the US and in Europe. The potential productivity of these three crops will be assessed in terms of carbon sequestration, surface energy and water balance and their spatial variability. This study will help to quantify the importance of various environmental aspects towards modeling bioenergy crops and to better understand the spatial and temporal dynamics of bioenergy crop yields.

  1. CO2 balance in production of energy based on biogas

    DEFF Research Database (Denmark)

    Nielsen, Per Sieverts; Holm-Nielsen, J.B.

    1997-01-01

    Biogas is an essential biomass source for achieving a reduction of CO2 emission by 50% in year 2030 in Denmark. The physical potential for biogas production in Denmark is more than 10 times the present biogas production in Denmark. In Denmark the largest part of the biogas production is produced...... of increased transportation distances at large biogas plants on the total CO2 balance of the biogas plant. The advantage of constructing large biogas plants is the cost-effective possibility of using industrial organic waste to increase biogas production. In some cases co-fermentation increases biogas...... production up 100%. The present study evaluate optimal transportation strategies for biogas plants taking CO2 balances into account....

  2. Approximation of theoretical energy-saving potentials for the petrochemical industry using energy balances for 68 key processes

    NARCIS (Netherlands)

    Neelis, M.L.; Patel, M.K.; Bach, P.; Haije, W.G.; Blok, K.

    2007-01-01

    We prepared energy and carbon balances for 68 petrochemical processes in the petrochemical industry for Western Europe, the Netherlands and the world. We analysed the process energy use in relation to the heat effects of the chemical reactions and quantified in this way the sum of all energy inputs

  3. Brazilian Energy Balance 2016 - calendar year 2015; Balanco energetico nacional 2016 - ano base 2015

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-07-01

    The BEB is divided into eight chapters and ten annexes, whose contents are as follow. Chapter 1 - Energy Analysis and Aggregated Data - presents energy highlights per source in 2015 and analyses the evolution of the domestic energy supply and its relationship with economic growth. Chapter 2 - Energy Supply and Demand by Source - has the accountancy, per primary and secondary energy sources, of the production, import, export, variation of stocks, losses, adjustments and total consumption disaggregated per socioeconomic sector in the country. Chapter 3 - Energy Consumption by Sector - presents the final energy consumption classified by primary and secondary source for each sector of the economy. Chapter 4 - Energy Imports and Exports - presents the evolution of the data on the import and export of energy and the dependence on external energy. Chapter 5 - Balance of Transformation Centers - presents the energy balances for the energy transformation centers including their losses. Chapter 6 - Energy Resources and Reserves - has the basic concepts use in the survey of resources and reserves of primary energy sources. Chapter 7 - Energy and Socioeconomics - contains a comparison of energy, economic and population parameters, specific consumption, energy intensities, average prices and spending on petroleum imports. Chapter 8 - State Energy Data - presents energy data for the states by Federal Unit, main energy source production, energy installations, reserves and hydraulic potential. Relating to annexes the current structure is presented bellow: Annex I - Installed Capacity - shows the installed capacity of electricity generation, the installed capacity of Itaipu hydro plant and the installed capacity for oil refining. Annex II - Self-production of Electricity - presents disaggregated data of self-production, considering sources and sectors. Annex III - World Energy Data - presents the main indicators for the production, import, export and consumption per energy source

  4. EEBFTC: Extended Energy Balanced with Fault Tolerance Capability Protocol for WSN

    Directory of Open Access Journals (Sweden)

    Mona M. Jamjoom

    2017-01-01

    Full Text Available This paper proposes a new framework for wireless sensor networks (WSN by combining two routing protocol algorithms. In the proposed framework two algorithms are taking into consideration the energy balanced clustering (EBC protocol in WSN with fault tolerance capabilities. The organizer is automatically selected by the base station (BS and then it selects the cluster head (CH. The mechanism of selecting the organizer node and the cluster head (CH is based on the power, efficacy and energy balance load. In addition, the organizer is responsible to select a new CH in case of failure and vice versa. So, the energy balanced clustering and fault tolerance operations will prolong the node life time and thus the network will be efficient in data transmission and more reliable. The new framework after implementation is named Extended Energy Balanced with Fault Tolerance Capability (EEBFTC protocol.

  5. Sleep restriction is not associated with a positive energy balance in adolescent boys

    DEFF Research Database (Denmark)

    Klingenberg, Lars; Chaput, Jean-Philippe; Holmbäck, Ulf

    2012-01-01

    A short sleep (SS) duration has been linked to obesity in observational studies. However, experimental evidence of the potential mechanisms of sleep restriction on energy balance is conflicting and, to our knowledge, nonexistent in adolescents....

  6. Developmental programming of energy balance regulation: Is physical activity more "programmable" than food intake

    Science.gov (United States)

    Extensive human and animal model data show that environmental influences during critical periods of prenatal and early postnatal development can cause persistent alterations in energy balance regulation. Although a potentially important factor in the worldwide obesity epidemic, the fundamental mecha...

  7. Breed and parity effects on energy balance profiles through lactation: evidence of genetically driven body energy change.

    Science.gov (United States)

    Friggens, N C; Berg, P; Theilgaard, P; Korsgaard, I R; Ingvartsen, K L; Løvendahl, P; Jensen, J

    2007-11-01

    The aim of this study was to characterize patterns of energy balance through lactation of cows kept under constant feeding conditions. Danish Holstein, Danish Red, and Jersey cows were studied during consecutive lactations and remained on the same dietary treatment throughout. They were fed a normal (13.55 MJ of digestible energy/kg of dry matter) or a lower energy diet (12.88 MJ of digestible energy/kg of dry matter) ad libitum throughout lactation. Energy balance was calculated using the effective energy (EE) system in such a way that energy balance equated to body energy reserve change. In the EE system the energy values assigned to feeds are directly equivalent to the energy requirements of the animal; 1 MJ of EE supply has the same energy value as 1 MJ of lipid loss from the body. The resulting body energy change data were analyzed using a linear spline model. There was no evidence to suggest that different combinations of breed and parity required different knot placements. The Holstein mobilized significantly more body energy in early lactation than the Danish Red and Jersey breeds. Parity 1 cows mobilized significantly less than parity 2 and 3 cows. There was a significant interaction between breed and parity in the first half of lactation due to parity 1 Jersey cows having a greater mobilization than would be expected of the difference between parities in the other breeds. As lactation progressed, the differences between parities and between breeds decreased. Cows on the higher energy diet had a more positive energy balance. Within breed and parity, the following possible predictors of individual differences in body energy change were examined: fatness-corrected live weight, condition score at calving, and genotype. There was no difference in the predicted cow effect or residual energy balance profile when grouped according to quartiles of corrected live weight or according to condition score at calving. During the period of most negative energy balance (d

  8. To Ingest or Rest? Specialized Roles of Lateral Hypothalamic Area Neurons in Coordinating Energy Balance

    Directory of Open Access Journals (Sweden)

    Juliette A. Brown

    2015-02-01

    Full Text Available Survival depends on an organism’s ability to sense nutrient status and accordingly regulate intake and energy expenditure behaviors. Uncoupling of energy sensing and behavior, however, underlies energy balance disorders such as anorexia or obesity. The hypothalamus regulates energy balance, and in particular the lateral hypothalamic area (LHA is poised to coordinate peripheral cues of energy status and behaviors that impact weight, such as drinking, locomotor behavior, arousal/sleep and autonomic output. There are several populations of LHA neurons that are defined by their neuropeptide content and contribute to energy balance. LHA neurons that express the neuropeptides melanin-concentrating hormone (MCH or orexins/hypocretins (OX are best characterized and these neurons play important roles in regulating ingestion, arousal, locomotor behavior and autonomic function via distinct neuronal circuits. Recently, another population of LHA neurons containing the neuropeptide Neurotensin (Nts has been implicated in coordinating anorectic stimuli and behavior to regulate hydration and energy balance. Understanding the specific roles of MCH, OX and Nts neurons in harmonizing energy sensing and behavior thus has the potential to inform pharmacological strategies to modify behaviors and treat energy balance disorders.

  9. Energy balance of maize production in Brazil: the energetic constraints of a net positive outcome

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Luis Henrique de Barros; Alves, Bruno Jose Rodrigues; Urquiaga, Segundo

    2008-07-01

    Among the factors used to analyze and to establish the sustainability of a whole agricultural production system, the energy balance is one of the most powerful and robust. The maize production in Brazil is surely the reflex of an energy intensive system that demands many field operations and heavy fertilizer applications, notably nitrogen in urea form. This work presents an energy balance of this major crop adjusted to the Brazilian conditions of cultivation. The input components were grouped based on their energy contents, and the possible improvements in the agricultural practices that could improve energy balance and net energy withdrawn from the farming were considered. The replacement of N synthetic fertilizer by biological nitrogen fixation, whether the process is directly carried out by endophytic diazotroph bacteria or by means of a N{sub 2}- fixing legume culture planted before the main crop as a green-manure is also discussed. (author)

  10. Energy Balanced Dynamic Deployment Optimization to Enhance Reliable Lifetime of Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    J.Roselin

    2013-08-01

    Full Text Available In Wireless Sensor Networks (WSNs, the available energy of sensor nodes is limited and hard to renew. The energy supervision is also very critical. In Mission Critical Surveillance application, due tonode’s battery depletion, coverage hole may be created. Hole at Critical Point (CP leads to performance degradation of overall network. It is merely impossible, to redeploy sensor nodes or to recharge the battery in middle run during monitoring. The proposed Energy Balanced-Dynamic Deployment (EB-DD Optimization approach, positions the self deployable mobile sensors towards CP according to its Energy Density. This balances the Energy Density of the network thereby increasing the Reliable Lifetime. The simulation results show the effectiveness of the approach in terms of balanced Energy Density around CPs with less mobility.

  11. Fuel Cells for Balancing Fluctuation Renewable Energy Sources

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad

    2007-01-01

    In the perspective of using fuel cells for integration of fluctuating renewable energy the SOFCs are the most promising. These cells have the advantage of significantly higher electricity efficiency than competing technologies and fuel flexibility. Fuel cells in general also have the advantage of...... with hydrogen production or electric cars, and on the other hand using biomass and bio fuels [11]. Fuel cells can have an important role in these future energy systems.......In the perspective of using fuel cells for integration of fluctuating renewable energy the SOFCs are the most promising. These cells have the advantage of significantly higher electricity efficiency than competing technologies and fuel flexibility. Fuel cells in general also have the advantage...... flexibility, such as SOFCs, heat pumps and heat storage technologies are more important than storing electricity as hydrogen via electrolysis in energy systems with high amounts of wind [12]. Unnecessary energy conversions should be avoided. However in future energy systems with wind providing more than 50...

  12. Energy and greenhouse gas balances of cassava-based ethanol

    NARCIS (Netherlands)

    Thanh, Le L.; Ierland, van E.C.; Zhu, X.; Wesseler, J.H.H.

    2013-01-01

    Biofuel production has been promoted to save fossil fuels and reduce greenhouse gas (GHG) emissions. However, there have been concerns about the potential of biofuel to improve energy efficiency and mitigate climate change. This paper investigates energy efficiency and GHG emission saving of cassava

  13. Neuronal energy-sensing pathway promotes energy balance by modulating disease tolerance.

    Science.gov (United States)

    Shen, Run; Wang, Biao; Giribaldi, Maria G; Ayres, Janelle; Thomas, John B; Montminy, Marc

    2016-06-01

    The starvation-inducible coactivator cAMP response element binding protein (CREB)-cAMP-regulated transcription coactivator (Crtc) has been shown to promote starvation resistance in Drosophila by up-regulating CREB target gene expression in neurons, although the underlying mechanism is unclear. We found that Crtc and its binding partner CREB enhance energy homeostasis by stimulating the expression of short neuropeptide F (sNPF), an ortholog of mammalian neuropeptide Y, which we show here is a direct target of CREB and Crtc. Neuronal sNPF was found to promote energy homeostasis via gut enterocyte sNPF receptors, which appear to maintain gut epithelial integrity. Loss of Crtc-sNPF signaling disrupted epithelial tight junctions, allowing resident gut flora to promote chronic increases in antimicrobial peptide (AMP) gene expression that compromised energy balance. Growth on germ-free food reduced AMP gene expression and rescued starvation sensitivity in Crtc mutant flies. Overexpression of Crtc or sNPF in neurons of wild-type flies dampens the gut immune response and enhances starvation resistance. Our results reveal a previously unidentified tolerance defense strategy involving a brain-gut pathway that maintains homeostasis through its effects on epithelial integrity.

  14. Solar energy research and development: program balance. Annex, Volume II

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-02-01

    Each of the seven solar energy technologies that have been assessed in the study are treated: photovoltaic devices, solar thermal power systems, wind energy systems, solar heating and cooling systems, agricultural and industrial heat processes, biomass conversion technologies, and ocean thermal energy conversion systems. A brief technical overview of storage for solar electric technologies is presented and some principles concerning how different levels of success on electrical storage can affect the commercial viability of solar electric options are discussed. A description is given of the solar penetration model that was developed and applied as an analytical tool in the study. This computer model has served the primary purpose of evaluating the competiveness of the solar energy systems in the markets in which they are expected to compete relative to that of the alternative energy sources. This is done under a variety of energy supply, demand, and price conditions. The seven sections treating the solar energy technologies contain discussions on each of six subject areas: description of the technology; economic projections; the potential contribution of the technology in different marketplaces; environmental considerations; international potential; and the present and possible future emphases within the RD and D program. The priority item for each of the technology sections has been the documentation of the economic projections.

  15. Electrochemical energy storage for renewable sources and grid balancing

    CERN Document Server

    Moseley, Patrick T

    2015-01-01

    Electricity from renewable sources of energy is plagued by fluctuations (due to variations in wind strength or the intensity of insolation) resulting in a lack of stability if the energy supplied from such sources is used in 'real time'. An important solution to this problem is to store the energy electrochemically (in a secondary battery or in hydrogen and its derivatives) and to make use of it in a controlled fashion at some time after it has been initially gathered and stored. Electrochemical battery storage systems are the major technologies for decentralized storage systems and hydrogen

  16. Effects of winter military training on energy balance, whole-body protein balance, muscle damage, soreness, and physical performance.

    Science.gov (United States)

    Margolis, Lee M; Murphy, Nancy E; Martini, Svein; Spitz, Marissa G; Thrane, Ingjerd; McGraw, Susan M; Blatny, Janet-Martha; Castellani, John W; Rood, Jennifer C; Young, Andrew J; Montain, Scott J; Gundersen, Yngvar; Pasiakos, Stefan M

    2014-12-01

    Physiological consequences of winter military operations are not well described. This study examined Norwegian soldiers (n = 21 males) participating in a physically demanding winter training program to evaluate whether short-term military training alters energy and whole-body protein balance, muscle damage, soreness, and performance. Energy expenditure (D2(18)O) and intake were measured daily, and postabsorptive whole-body protein turnover ([(15)N]-glycine), muscle damage, soreness, and performance (vertical jump) were assessed at baseline, following a 4-day, military task training phase (MTT) and after a 3-day, 54-km ski march (SKI). Energy intake (kcal·day(-1)) increased (P < 0.01) from (mean ± SD (95% confidence interval)) 3098 ± 236 (2985, 3212) during MTT to 3461 ± 586 (3178, 3743) during SKI, while protein (g·kg(-1)·day(-1)) intake remained constant (MTT, 1.59 ± 0.33 (1.51, 1.66); and SKI, 1.71 ± 0.55 (1.58, 1.85)). Energy expenditure increased (P < 0.05) during SKI (6851 ± 562 (6580, 7122)) compared with MTT (5480 ± 389 (5293, 5668)) and exceeded energy intake. Protein flux, synthesis, and breakdown were all increased (P < 0.05) 24%, 18%, and 27%, respectively, during SKI compared with baseline and MTT. Whole-body protein balance was lower (P < 0.05) during SKI (-1.41 ± 1.11 (-1.98, -0.84) g·kg(-1)·10 h) than MTT and baseline. Muscle damage and soreness increased and performance decreased progressively (P < 0.05). The physiological consequences observed during short-term winter military training provide the basis for future studies to evaluate nutritional strategies that attenuate protein loss and sustain performance during severe energy deficits.

  17. Balancing Renewable Electricity Energy Storage, Demand Side Management, and Network Extension from an Interdisciplinary Perspective

    CERN Document Server

    Droste-Franke, Bert; Rehtanz, Christian; Sauer, Dirk Uwe; Schneider, Jens-Peter; Schreurs, Miranda; Ziesemer, Thomas

    2012-01-01

    A significant problem of integrating renewable energies into the electricity system is the temporally fluctuating energy production by wind and solar power plants. Thus, in order to meet the ambitious long-term targets on CO2 emission reduction, long-term viable low-carbon options for balancing electricity will be needed. This interdisciplinary study analyses published future energy scenarios in order to get an impression of the required balancing capacities and shows which framework conditions should be modified to support their realisation. The authors combine their perspectives from energy engineering, technology assessment, political science, economical science and jurisprudence and address science, politics, actors in the energy sector and the interested public. Respectively, requirements for the balancing systems are analysed, considering the case of Germany as a large country with high ambitions to reduce greenhouse gas emissions. Additionally, an approach to investigate the optimal design of the techn...

  18. Capacitor voltage ripple reduction and arm energy balancing in MMC-HVDC

    DEFF Research Database (Denmark)

    Martin-Loeches, Ruben Sánches; Parikh, Harsh; Tsolaridis, Georgios

    2016-01-01

    Modular Multilevel Converters are emerging and widely used in HVDC applications. However, the submodule capacitors are still large and the energy balancing under unbalanced conditions is a challenge. In this paper, an analytical model focusing on the energy stored in the capacitors and voltage...... variations is utilized in order to achieve better performance. By injecting a second order harmonic component into the circulating current, the energy variation and consequently the capacitor voltage ripple is reduced allowing for a capacitor size reduction. At the same time, an arm energy balancing...... controller has been proposed which uses the first harmonic of the circulating current in order to keep the energy balance of the leg under internal unbalanced conditions....

  19. Energy balance in the solar transition region. I - Hydrostatic thermal models with ambipolar diffusion

    Science.gov (United States)

    Fontenla, J. M.; Avrett, E. H.; Loeser, R.

    1990-01-01

    The energy balance in the lower transition region is analyzed by constructing theoretical models which satisfy the energy balance constraint. The energy balance is achieved by balancing the radiative losses and the energy flowing downward from the corona. This energy flow is mainly in two forms: conductive heat flow and hydrogen ionization energy flow due to ambipolar diffusion. Hydrostatic equilibrium is assumed, and, in a first calculation, local mechanical heating and Joule heating are ignored. In a second model, some mechanical heating compatible with chromospheric energy-balance calculations is introduced. The models are computed for a partial non-LTE approach in which radiation departs strongly from LTE but particles depart from Maxwellian distributions only to first order. The results, which apply to cases where the magnetic field is either absent, or uniform and vertical, are compared with the observed Lyman lines and continuum from the average quiet sun. The approximate agreement suggests that this type of model can roughly explain the observed intensities in a physically meaningful way, assuming only a few free parameters specified as chromospheric boundary conditions.

  20. Electrical energy balance contest in Solar Decathlon Europe 2012

    OpenAIRE

    2014-01-01

    Solar Decathlon Europe (SDE) is an international multidisciplinary competition in which 20 universityteams build and operate energy-efficient solar-powered houses. The aim of SDE is not only scientificbut also educational and divulgative, making visitors to understand the problems presented by realengineering applications and architecture. From a research perspective, the energy data gathered dur-ing the competition constitutes a very promising information for the analysis and understanding o...

  1. Brazilian national energy balance 2007. Calendar year 2006[Includes executive summary 2007]; Balanco energetico nacional 2007. Ano base 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This document reports the activities of the Ministry of Mine and Energy, during the calendar year 2006 as follows: energy analysis and aggregated data; supply and demand of energy according to source; energy consumption according to sector; energy external trading; transformation center balance; energy resources and reserves; energy and social economics; state energy data; installed capacity; energy world data.

  2. Energy balance of biofuel production from biological conversion of crude glycerol.

    Science.gov (United States)

    Zhang, Xiaolei; Yan, Song; Tyagi, Rajeshwar D; Surampalli, Rao Y; Valéro, Jose R

    2016-04-01

    Crude glycerol, a by-product of biodiesel production, has gained significant attention as a carbon source for biofuel production. This study evaluated the energy balance of biodiesel, hydrogen, biogas, and ethanol production from 3.48 million L of crude glycerol (80% w/v). The conversion efficiency (energy output divided by energy invested) was 1.16, 0.22, 0.27, and 0.40 for the production of biodiesel, hydrogen, biogas, and ethanol respectively. It was found that the use of crude glycerol for biodiesel production was an energy gain process, with a positive energy balance and conversion efficiency of greater than 1. The energy balance revealed a net energy gain of 5226 GJ per 1 million kg biodiesel produced. Production of hydrogen, biogas and ethanol from crude glycerol were energy loss processes. Therefore, the conversion of crude glycerol to lipids and subsequently to biodiesel is suggested to be a better option compared to hydrogen, biogas, or ethanol production with respect to energy balance.

  3. World Energy Balance Outlook and OPEC Production Capacity: Implications for Global Oil Security

    OpenAIRE

    2012-01-01

    The imbalance between energy resource availability, demand, and production capacity, coupled with inherent economic and environmental uncertainties make strategic energy resources planning, management, and decision-making a challenging process. In this paper, a descriptive approach has been taken to synthesize the world’s energy portfolio and the global energy balance outlook in order to provide insights into the role of Organization of Petroleum Exporting Countries (OPEC) in maintaining “sta...

  4. Phenotypic profiles for body weight, body condition score, energy intake, and energy balance across different parities and concentrate feeding levels

    NARCIS (Netherlands)

    Berry, D.P.; Veerkamp, R.F.; Dillon, P.

    2006-01-01

    The objective of this study was to investigate potential differences in lactation profiles for body weight (BW), body condition score (BCS), net energy intake (NEI) and energy balance (EB) across different parities and concentrate feeding levels. Records collected from the research farm in southern

  5. Effect of dry period length and dietary energy source on energy balance, milk yield, and milk composition of dairy cows

    NARCIS (Netherlands)

    Knegsel, van A.T.M.; Remmelink, G.J.; Jorjong, S.; Fievez, V.; Kemp, B.

    2014-01-01

    The objective of this study was to evaluate the effects of dry period length and dietary energy source in early lactation on milk production, feed intake, and energy balance (EB) of dairy cows. Holstein-Friesian dairy cows (60 primiparous and 108 multiparous) were randomly assigned to dry period len

  6. Effects of dietary energy source on energy balance, metabolites and reproduction variables in dairy cows in early lactation

    NARCIS (Netherlands)

    Knegsel, van A.T.M.; Brand, van den H.; Dijkstra, J.; Kemp, B.

    2007-01-01

    This paper summarizes three recent studies by the same authors with the objective to study the effect of dietary energy source on the energy balance (EB) and risk for metabolic and reproductive disorders in dairy cows in early lactation. The first study, a literature survey, illustrated that feeding

  7. Balancing renewable electricity. Energy storage, demand side management, and network extension from an interdisciplinary perspective

    Energy Technology Data Exchange (ETDEWEB)

    Droste-Franke, Bert [Europaeische Akademie zur Erforschung von Folgen Wissenschaftlich-Technischer Entwicklungen GmbH, Bad Neuenahr-Ahrweiler (Germany); Paal, Boris P.; Rehtanz, Christian; Sauer, Dirk Uwe; Schneider, Jens-Peter; Schreurs, Miranda; Ziesemer, Thomas

    2012-07-01

    A significant problem of integrating renewable energies into the electricity system is the temporally fluctuating energy production by wind and solar power plants. Thus, in order to meet the ambitious long-term targets on CO{sub 2} emission reduction, long-term viable low-carbon options for balancing electricity will be needed. This interdisciplinary study analyses published future energy scenarios in order to get an impression of the required balancing capacities and shows which framework conditions should be modified to support their realisation. The authors combine their perspectives from energy engineering, technology assessment, political science, economical science and jurisprudence and address science, politics, actors in the energy sector and the interested public. Respectively, requirements for the balancing systems are analysed, considering the case of Germany as a large country with high ambitions to reduce greenhouse gas emissions. Additionally, an approach to investigate the optimal design of the technical system for balancing electricity over Europe is sketched. Looking at the challenges of a future energy system a mix of complementary technologies will prospectively become prevalent. In order to foster the needed innovation processes adequately, several funding mechanisms and legal regulations should be adapted. The authors give recommendations to handle major challenges in the development of the technical infrastructure, for the design of market conditions and for specific support of the application of balancing technologies. (orig.)

  8. Soil heat flux and day time surface energy balance closure at astronomical observatory, Thiruvananthapuram, south Kerala

    Indian Academy of Sciences (India)

    M S Roxy; V B Sumithranand; G Renuka

    2014-06-01

    Soil heat flux is an important input component of surface energy balance. Estimates of soil heat flux were made in the year 2008 using soil temperature data at Astronomical Observatory, Thiruvananthapuram, south Kerala. Hourly values of soil heat flux from 00 to 24 LST are presented for selected days typical of the winter, pre-monsoon, SW monsoon and NE monsoon seasons. The diurnal variation is characterized by a cross-over from negative to positive values at 0700 h, occurrence of maximum around noon and return to negative values in the late evening. The energy storage term for the soil layer 0–0.05 m is calculated and the ground heat flux * is estimated in all seasons. Daytime surface energy balance at the surface on wet and dry seasons is investigated. The average Bowen’s ratio during the wet and dry seasons were 0.541 and 0.515, respectively indicating that considerable evaporation takes place at the surface. The separate energy balance components were examined and the mean surface energy balance closure was found to be 0.742 and 0.795 for wet and dry seasons, respectively. When a new method that accounts for both soil thermal conduction and soil thermal convection was adopted to calculate the surface heat flux, the energy balance closure was found to be improved. Thus on the land surface under study, the soil vertical water movement is significant.

  9. Integration of microalgae systems at municipal wastewater treatment plants: implications for energy and emission balances.

    Science.gov (United States)

    Menger-Krug, Eve; Niederste-Hollenberg, Jutta; Hillenbrand, Thomas; Hiessl, Harald

    2012-11-06

    Integrating microalgae systems (MAS) at municipal wastewater treatment plants (WWTPs) to produce of bioenergy offers many potential synergies. Improved energy balances provide a strong incentive for WWTPs to integrate MAS, but it is crucial that WWTPs maintain their barrier function to protect water resources. We perform a prospective analysis of energy and emission balances of a WWTP with integrated MAS, based on a substance flow analysis of the elements carbon (C), nitrogen (N), and phosphorus (P). These elements are the main ingredients of wastewater, and the key nutrients for algae growth. We propose a process design which relies solely on resources from wastewater with no external input of water, fertilizer or CO(2). The whole process chain, from cultivation to production of bioelectricity, takes place at the WWTP. Our results show that MAS can considerably improve energy balances of WWTPs without any external resource input. With optimistic assumptions, they can turn WWTPs into net energy producers. While intensive C recycling in MAS considerably improves the energy balance, we show that it also impacts on effluent quality. We discuss the importance of nonharvested biomass for effluent quality and highlight harvesting efficiency as key factor for energy and emission balances of MAS at WWTP.

  10. Saving Energy in Historic Buildings: Balancing Efficiency and Value

    Science.gov (United States)

    Cluver, John H.; Randall, Brad

    2012-01-01

    By now the slogan of the National Trust for Historic Preservation that "the greenest building is the one already built" is widely known. In an era of increased environmental awareness and rising fuel prices, however, the question is how can historic building stock be made more energy efficient in a manner respectful of its historic integrity and…

  11. Balancing energy and the environment: the case of geothermal development

    Energy Technology Data Exchange (ETDEWEB)

    Ellickson, P.L.; Brewer, S.

    1978-06-01

    The results of part of a Rand study on the federal role in resolving environmental issues arising out of the implementation of energy projects are reported. The projects discussed are two geothermal programs in California: the steam resource development at The Geysers (Lake and Sonoma counties) in northern California, and the wet brine development in the Imperial Valley in southern California.

  12. The Energy Balance of Corn Ethanol: An Update

    Energy Technology Data Exchange (ETDEWEB)

    Shapouri, Hosein [United States Dept. of Agriculture (USDA), Washington DC (United States); Duffield, James A. [United States Dept. of Agriculture (USDA), Washington DC (United States); Wang, Michael [Argonne National Lab. (ANL), Argonne, IL (United States)

    2002-07-01

    Studies conducted since the late 1970s have estimated the net energy value (NEV) of corn ethanol. However, variations in data and assumptions used among the studies have resulted in a wide range of estimates. This study identifies the factors causing this wide variation and develops a more consistent estimate.

  13. Balancing act: Government roles in an energy conservation network

    NARCIS (Netherlands)

    Peterman, A.; Kourula, A.; Levitt, R.

    2014-01-01

    Government-led interorganizational alliance networks present a sensible opportunity to overcome many societal challenges through collaborative governance. In particular, few researchers have studied alliance networks in the field of energy conservation in commercial buildings—a sector with unique ba

  14. An integrated model of soil-canopy spectral radiance observations, photosynthesis, fluorescence, temperature and energy balance

    Directory of Open Access Journals (Sweden)

    C. van der Tol

    2009-06-01

    Full Text Available This paper presents the model SCOPE (Soil Canopy Observation, Photochemistry and Energy fluxes, which is a vertical (1-D integrated radiative transfer and energy balance model. It calculates the radiation and the energy balance of a vegetated land surface at the level of single leaves as well as at canopy level, and the spectrum of the outgoing radiation in the viewing direction, at a high spectral resolution over the range from 0.4 to 50 μm, thus including the visible, near and shortwave infrared, as well as the thermal domain. A special routine is dedicated to the calculation of chlorophyll fluorescence. The calculation of radiative transfer and the energy balance is fully integrated, allowing for feedback between surface temperatures, leaf chlorophyll fluorescence and radiative fluxes. Model simulations were evaluated against observations reported in the literature. The model may serve as a theoretical ground truth to derive relationships between observed spectra and physical processes at the land surface.

  15. [Energy balance and evapotranspiration in broad-leaved Korean pine forest in Changbai Mountains].

    Science.gov (United States)

    Zhang, Xin-jian; Yuan, Feng-hui; Chen, Ni-na; Deng, Jun-li; Yu, Xiao-zhou; Sheng, Xue-jiao

    2011-03-01

    Based on the continuous measurements of an open-path eddy covariance system, this paper analyzed the characteristics of energy balance components and evapotranspiration in a broad-leaved Korean pine forest in Changbai Mountains in 2008, as well as the differences of energy balance components and evapotranspiration between growth season and dormant season. For the test forest, the year-round energy balance closure was 72%, being at a medium level, compared to the other studies in the Fluxnet community. The energy balance components had significant differences in their diurnal and seasonal variations. In growth season, turbulent energy exchange was dominated by upward latent heat flux, accounting for 66% of available energy; while in dormant season, the turbulent energy exchange was dominated by upward sensible heat flux, accounting for 63% of available energy. The accumulated annual evapotranspiration in the study site in 2008 was 484.7 mm, occupying 87% of the precipitation at the same time period (558.9 mm), which demonstrated that evapotranspiration was the main water loss item in temperate forests of northern China.

  16. Natural Antibodies Related to Energy Balance in Early Lactation Dairy Cows

    NARCIS (Netherlands)

    Knegsel, van A.T.M.; Vries Reilingh, de G.; Meulenberg, S.; Brand, van den H.; Dijkstra, J.; Kemp, B.; Parmentier, H.K.

    2007-01-01

    The objectives of this study were to determine the presence of natural antibodies (NAb) in plasma and milk of individual dairy cows and to study the relation between NAb concentrations and energy balance (EB) and dietary energy source. Cows (n = 76) were fed a mainly glucogenic, lipogenic, or a mixt

  17. Effects of activity and energy budget balancing algorithm on laboratory performance of a fish bioenergetics model

    Science.gov (United States)

    Madenjian, Charles P.; David, Solomon R.; Pothoven, Steven A.

    2012-01-01

    We evaluated the performance of the Wisconsin bioenergetics model for lake trout Salvelinus namaycush that were fed ad libitum in laboratory tanks under regimes of low activity and high activity. In addition, we compared model performance under two different model algorithms: (1) balancing the lake trout energy budget on day t based on lake trout energy density on day t and (2) balancing the lake trout energy budget on day t based on lake trout energy density on day t + 1. Results indicated that the model significantly underestimated consumption for both inactive and active lake trout when algorithm 1 was used and that the degree of underestimation was similar for the two activity levels. In contrast, model performance substantially improved when using algorithm 2, as no detectable bias was found in model predictions of consumption for inactive fish and only a slight degree of overestimation was detected for active fish. The energy budget was accurately balanced by using algorithm 2 but not by using algorithm 1. Based on the results of this study, we recommend the use of algorithm 2 to estimate food consumption by fish in the field. Our study results highlight the importance of accurately accounting for changes in fish energy density when balancing the energy budget; furthermore, these results have implications for the science of evaluating fish bioenergetics model performance and for more accurate estimation of food consumption by fish in the field when fish energy density undergoes relatively rapid changes.

  18. Eawag Forum Chriesbach - Detailed energy balance - Final report; Energie-Detailbilanz des Eawag Forum Chriesbach - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Guettinger, H.; Lichtensteiger, T.; Mauz, M. [Eidgenoessische Anstalt fuer Wasserversorgung, Abwasserreinigung und Gewaesserschutz, EAWAG, Duebendorf (Switzerland); Velsen, S. van [3-Plan Haustechnik AG, Winterthur (Switzerland); Lehmann, B.; Frank, T.; Dorer, V.; Beerle, D. [Eidgenoessische Materialpruefungs- und Forschungsanstalt, EMPA, Duebendorf (Switzerland)

    2009-06-15

    In June 2006 Eawag moved into its new headquarters, Forum Chriesbach. The building's external appearance is striking owing to the 1232 blue glass panels which clad the compact 6-storey rectangular structure. Eawag Forum Chriesbach houses 150 workplaces, a staff cafeteria, meeting and seminar rooms as well as the library of Eawag and Empa. It is an exemplary illustration of 'sustainable' construction design and is one of the best known buildings in Switzerland. It has been awarded several prizes and described in numerous national and international publications. The building is modern, functional, aesthetic, and uses a unique array of sources for heating, including the sun as well as waste heat from light sources, electric appliances and people. Cooling requirements are very low. Only electricity requirements and the embedded energy of construction materials are of significance. Approximately one third of the electricity required, namely 70 MWh/a, is produced by photovoltaic panels on the roof, and the rest is purchased as renewable electricity from the utilities under the label 'nature-made star'. During a two-year optimization period the building's control system was adjusted and know-how was transferred from planners and builders to owners and facility managers. From autumn 2007 Eawag, Empa and 3-Plan Haustechnik AG carried out temperature and energy measurements to determine the extent to which original planning assumptions and simulation forecasts corresponded to actual experience. Computer simulations with TRNSYS have revealed the relative contribution of individual building components to the overall energy balance and their sensitivity to external parameters. Temperatures during hot summer days have remained in comfortable ranges below 26 {sup o}C and have usually ranged between 20 and 23 {sup o}C in winter. Although heating and electricity requirements have exceeded predicted levels, at 5.7 kWh/m{sup 2} weighted energy reference

  19. Appetite control and energy balance : impact of exercise

    OpenAIRE

    Blundell, J. E.; Gibbons, C.; Caudwell, P; Finlayson, G; Hopkins, Mark

    2015-01-01

    Exercise is widely regarded as one of the most valuable components of behaviour that can influence body weight and therefore help in the prevention and management of obesity. Indeed long term controlled trials show a clear dose related effect of exercise on body weight. However, there is a suspicion, particularly fuelled by media reports, that exercise serves to increase hunger and drive up food intake thereby nullifying the energy expended through activity. Not everyone performing regular ex...

  20. Energy metabolism and fertility: a balance preserved for female health.

    OpenAIRE

    Sara Della Torre; Valeria Benedusi; Roberta Fontana; Adriana Maggi

    2013-01-01

    In female animals, energy metabolism and fertility are tightly connected, and reciprocally regulated. However, the relative contributions of metabolic and reproductive pathways have changed over the course of evolution. In oviparous animals, metabolic factors take precedence over fertility, enabling egg production to be inhibited in a nutritionally poor environment. By contrast, in placental mammals, the opposite occurs: the need to feed a developing embryo and neonate forces metabolic pathwa...

  1. Assessing Numerical Error in Structural Dynamics Using Energy Balance

    Directory of Open Access Journals (Sweden)

    Rabindranath Andujar

    2013-01-01

    Full Text Available This work applies the variational principles of Lagrange and Hamilton to the assessment of numerical methods of linear structural analysis. Different numerical methods are used to simulate the behaviour of three structural configurations and benchmarked in their computation of the Lagrangian action integral over time. According to the principle of energy conservation, the difference at each time step between the kinetic and the strain energies must equal the work done by the external forces. By computing this difference, the degree of accuracy of each combination of numerical methods can be assessed. Moreover, it is often difficult to perceive numerical instabilities due to the inherent complexities of the modelled structures. By means of the proposed procedure, these complexities can be globally controlled and visualized in a straightforward way. The paper presents the variational principles to be considered for the collection and computation of the energy-related parameters (kinetic, strain, dissipative, and external work. It then introduces a systematic framework within which the numerical methods can be compared in a qualitative as well as in a quantitative manner. Finally, a series of numerical experiments is conducted using three simple 2D models subjected to the effect of four different dynamic loadings.

  2. Comparing annual and perennial crops for bioenergy production - influence on nitrate leaching and energy balance

    DEFF Research Database (Denmark)

    Pugesgaard, Siri; Schelde, Kirsten; Ugilt Larsen, Søren

    2015-01-01

    concentration in soil water was measured below winter wheat, grass-clover and willow during three growing seasons. Crop water balances were modelled to estimate the amount of nitrate leached per hectare. In addition, dry matter yields and nitrogen (N) yields were measured, and N balances and energy balances...... was also measured in an old willow crop established in 1996 from which N leaching ranged from 6 to 27 kg ha−1 yr−1. Dry matter yields ranged between 5.9 and 14.8 Mg yr−1 with lowest yield in the newly established willow and the highest yield harvested in grass-clover. Grass-clover gave the highest net...

  3. Fixed energy balance window quench correction for high precision LSC {sup 14}C dating

    Energy Technology Data Exchange (ETDEWEB)

    Tudyka, Konrad, E-mail: konrad.tudyka@polsl.pl [GADAM Centre of Excellence Gliwice Absolute Dating Methods Centre, Silesian University of Technology, Krzywoustego 2, 44-100 Gliwice (Poland); Pawlyta, Jacek; Pazdur, Anna [GADAM Centre of Excellence Gliwice Absolute Dating Methods Centre, Silesian University of Technology, Krzywoustego 2, 44-100 Gliwice (Poland)

    2011-10-15

    In this paper we present the new LSC spectra evaluation method for high precision {sup 14}C dating with Quantulus 1220{sup TM}. The generally used fixed window is replaced with the fixed energy balanced counting window. The lower and upper channel of the window in the multichannel analyzer vary according to the quench level of each individual measurement. The position of the window is determined with the external standard quench parameter SQP(E) of Quantulus 1220{sup TM}. We show how this fixed energy balance window for each sample secures high stability and reduced quench correction. This method is compared with the typically used fixed channel window. - Highlights: > In this paper we present the new LSC spectra evaluation method. > We show how to setup fixed energy balance window. > The lower and upper channel of the window vary according to the quench level of each individual measurement. > We show how fixed energy balance window secures high stability. > We show the benefits of the fixed energy balance window.

  4. Energy balanced strategies for maximizing the lifetime of sparsely deployed underwater acoustic sensor networks.

    Science.gov (United States)

    Luo, Hanjiang; Guo, Zhongwen; Wu, Kaishun; Hong, Feng; Feng, Yuan

    2009-01-01

    Underwater acoustic sensor networks (UWA-SNs) are envisioned to perform monitoring tasks over the large portion of the world covered by oceans. Due to economics and the large area of the ocean, UWA-SNs are mainly sparsely deployed networks nowadays. The limited battery resources is a big challenge for the deployment of such long-term sensor networks. Unbalanced battery energy consumption will lead to early energy depletion of nodes, which partitions the whole networks and impairs the integrity of the monitoring datasets or even results in the collapse of the entire networks. On the contrary, balanced energy dissipation of nodes can prolong the lifetime of such networks. In this paper, we focus on the energy balance dissipation problem of two types of sparsely deployed UWA-SNs: underwater moored monitoring systems and sparsely deployed two-dimensional UWA-SNs. We first analyze the reasons of unbalanced energy consumption in such networks, then we propose two energy balanced strategies to maximize the lifetime of networks both in shallow and deep water. Finally, we evaluate our methods by simulations and the results show that the two strategies can achieve balanced energy consumption per node while at the same time prolong the networks lifetime.

  5. Energy Balanced Strategies for Maximizing the Lifetime of Sparsely Deployed Underwater Acoustic Sensor Networks

    Directory of Open Access Journals (Sweden)

    Hanjiang Luo

    2009-08-01

    Full Text Available Underwater acoustic sensor networks (UWA-SNs are envisioned to perform monitoring tasks over the large portion of the world covered by oceans. Due to economics and the large area of the ocean, UWA-SNs are mainly sparsely deployed networks nowadays. The limited battery resources is a big challenge for the deployment of such long-term sensor networks. Unbalanced battery energy consumption will lead to early energy depletion of nodes, which partitions the whole networks and impairs the integrity of the monitoring datasets or even results in the collapse of the entire networks. On the contrary, balanced energy dissipation of nodes can prolong the lifetime of such networks. In this paper, we focus on the energy balance dissipation problem of two types of sparsely deployed UWA-SNs: underwater moored monitoring systems and sparsely deployed two-dimensional UWA-SNs. We first analyze the reasons of unbalanced energy consumption in such networks, then we propose two energy balanced strategies to maximize the lifetime of networks both in shallow and deep water. Finally, we evaluate our methods by simulations and the results show that the two strategies can achieve balanced energy consumption per node while at the same time prolong the networks lifetime.

  6. Intraseasonal Variations in Tropical Energy Balance: Relevance to Climate Sensitivity?

    Science.gov (United States)

    Robertson, Franklin R.; Ramey, Holly S.; Roberts, Jason B.

    2011-01-01

    Intraseasonal variability of deep convection represents a fundamental mode of organization for tropical convection. While most studies of intraseasonal oscillations (ISOs) have focused on the spatial propagation and dynamics of convectively coupled circulations, here we examine the projection of ISOs on the tropically-averaged heat and moisture budget. One unresolved question concerns the degree to which observable variations in the "fast" processes (e.g. convection, radiative / turbulent fluxes) can inform our understanding of feedback mechanisms operable in the context of climate change. Our analysis use daily data from satellite observations, the Modern Era analysis for Research and Applications (MERRA), and other model integrations to address these questions: (i) How are tropospheric temperature variations related to that tropical deep convection and the associated ice cloud fractional amount (ICF), ice water path (IWP), and properties of warmer liquid clouds? (ii) What role does moisture transport play vis-a-vis ocean latent heat flux in enabling the evolution of deep convection to mediate PBL - free atmospheric temperature equilibration? (iii) What affect do convectively generated upper-tropospheric clouds have on the TOA radiation budget? Our methodology is similar to that of Spencer et al., (2007 GRL ) whereby a composite time series of various quantities over 60+ ISO events is built using tropical mean tropospheric temperature signal as a reference to which the variables are related at various lag times (from -30 to +30 days). The area of interest encompasses the global oceans between 20oN/S. The increase of convective precipitation cannot be sustained by evaporation within the domain, implying strong moisture transports into the tropical ocean area. The decrease in net TOA radiation that develops after the peak in deep convective rainfall, is part of the response that constitutes a "discharge" / "recharge" mechanism that facilitates tropical heat balance

  7. A load-balanced minimum energy routing algorithm for Wireless Ad Hoc Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Wireless Ad Hoc Sensor Networks (WSNs) have received considerable academia research attention at present. The energy-constraint sensor nodes in WSNs operate on limited batteries, so it is a very important issue to use energy efficiently and reduce power consumption. To maximize the network lifetime, it is essential to prolong each individual node's lifetime through minimizing the transmission energy consumption, so that many minimum energy routing schemes for traditional mobile ad hoc network have been developed for this reason. This paper presents a novel minimum energy routing algorithm named Load-Balanced Minimum Energy Routing (LBMER) for WSNs considering both sensor nodes' energy consumption status and the sensor nodes'hierarchical congestion levels, which uses mixture of energy balance and traffic balance to solve the problem of "hot spots" of WSNs and avoid the situation of"hot spots" sensor nodes using their energy at much higher rate and die much faster than the other nodes. The path router established by LBMER will not be very congested and the traffic will be distributed evenly in the WSNs.Simulation results verified that the LBMER performance is better than that of Min-Hop routing and the existing minimum energy routing scheme MTPR (Total Transmission Power Routing).

  8. Region Based Energy Balanced Inter-cluster communication Protocol for Sensor networks

    OpenAIRE

    Sharma, Rohini; Loboyal, D. K.

    2015-01-01

    Wireless sensor networks faces unbalanced energy consumption problem over time. Clustering provides an energy efficient method to improve lifespan of the sensor network. Cluster head collects data from other nodes and transmits it towards the sink node. Cluster heads which are far-off from the sink, consumes more power in transmission of information towards the sink. We propose Region Based Energy Balanced Inter-cluster communication protocol (RBEBP) to improve lifespan of the sensor network....

  9. Generating a positive energy balance from using rice straw for anaerobic digestion

    Directory of Open Access Journals (Sweden)

    V.H. Nguyen

    2016-11-01

    The net energy of the rice straw supply chain for biogas generation through AD is 3,500 MJ per ton of straw. This rice straw management option can provide a 70% net output energy benefit. The research highlighted the potential of rice straw as a clean fuel source with a positive energy balance, helping to reduce greenhouse gas emissions compared with the existing practice of burning it in the field.

  10. Processes governing the mass balance of Chhota Shigri Glacier (Western Himalaya, India assessed by point-scale surface energy balance measurements

    Directory of Open Access Journals (Sweden)

    M. F. Azam

    2014-06-01

    Full Text Available Recent studies revealed that Himalayan glaciers have been shrinking at an accelerated rate since the beginning of the 21st century. However the climatic causes for this shrinkage remain unclear given that surface energy balance studies are almost nonexistent in this region. In this study, a point-scale surface energy balance analysis was performed using in-situ meteorological data from the ablation zone of Chhota Shigri Glacier over two separate periods (August 2012 to February 2013 and July to October 2013 in order to understand the response of mass balance to climate change. Energy balance numerical modeling provides quantification of the surface energy fluxes and identification of the factors affecting glacier mass balance. The computed ablation was validated by stake observations. During summer-monsoon period, net radiation was the primary component of the surface energy balance with 82% of the total heat flux which was complimented with turbulent sensible and latent heat fluxes with a share of 13% and 5%, respectively. A striking feature of energy balance is the positive turbulent latent heat flux, thus condensation or re-sublimation of moist air at the glacier surface takes place, during summer-monsoon period which is characterized by relatively high air temperature, high relative humidity and almost permanent melting surface. The impact of Indian summer monsoon on Chhota Shigri Glacier mass balance has also been assessed. This analysis demonstrates that the intensity of snowfall events during the summer-monsoon season plays a key role on surface albedo, in turn on melting, and thus is among the most important drivers controlling the annual mass balance of the glacier. Summer-monsoon air temperature, controlling the precipitation phase (rain vs. snow and thus albedo, counts, indirectly, also among the most important drivers for the glacier mass balance.

  11. An Analysis of Turbulent Heat Fluxes and the Energy Balance During the REFLEX Campaign

    Directory of Open Access Journals (Sweden)

    Tol Christiaan van der

    2015-12-01

    Full Text Available Three eddy covariance stations were installed at the Barrax experimental farm during the Land-Atmosphere Exchanges (REFLEX airborne training and measurement campaign to provide ground truth data of energy balance fluxes and vertical temperature and wind profiles. The energy balance closure ratio (EBR was 105% for a homogeneous camelina site, 86% at a sparse reforestation site, and 73% for a vineyard. We hypothesize that the lower closure in the last site was related to the limited fetch. Incorporating a vertical gradient of soil thermal properties decreased the RMSE of the energy balance at the camelina site by 16 W m-2. At the camelina site, eddy covariance estimates of sensible and latent heat fluxes could be reproduced well using mean vertical profiles of wind and temperature, provided that the Monin-Obukhov length is known. Measured surface temperature and sensible heat fluxes suggested high excess resistance for heat (kB-1 = 17.

  12. On the balance energy and nuclear dynamics in peripheral heavy-ion collisions

    CERN Document Server

    Chugh, Rajiv

    2010-01-01

    We present here the system size dependence of balance energy for semi-central and peripheral collisions using quantum molecular dynamics model. For this study, the reactions of $Ne^{20}+Ne^{20}$, $Ca^{40}+Ca^{40}$, $Ni^{58}+Ni^{58}$, $Nb^{93}+Nb^{93}$, $Xe^{131}+Xe^{131}$ and $Au^{197}+Au^{197}$ are simulated at different incident energies and impact parameters. A hard equation of state along with nucleon-nucleon cross-sections between 40 - 55 mb explains the data nicely. Interestingly, balance energy follows a power law $\\propto{A^{\\tau}}$ for the mass dependence at all colliding geometries. The power factor $\\tau$ is close to -1/3 in central collisions whereas it is -2/3 for peripheral collisions suggesting stronger system size dependence at peripheral geometries. This also suggests that in the absence of momentum dependent interactions, Coulomb's interaction plays an exceedingly significant role. These results are further analyzed for nuclear dynamics at the balance point.

  13. Surface-Parallel Sensor Orientation for Assessing Energy Balance Components on Mountain Slopes

    Science.gov (United States)

    Serrano-Ortiz, P.; Sánchez-Cañete, E. P.; Olmo, F. J.; Metzger, S.; Pérez-Priego, O.; Carrara, A.; Alados-Arboledas, L.; Kowalski, A. S.

    2016-03-01

    The consistency of eddy-covariance measurements is often evaluated in terms of the degree of energy balance closure. Even over sloping terrain, instrumentation for measuring energy balance components is commonly installed horizontally, i.e. perpendicular to the geo-potential gradient. Subsequently, turbulent fluxes of sensible and latent heat are rotated perpendicular to the mean streamlines using tilt-correction algorithms. However, net radiation (Rn) and soil heat fluxes ( G) are treated differently, and typically only Rn is corrected to account for slope. With an applied case study, we show and argue several advantages of installing sensors surface-parallel to measure surface-normal Rn and G. For a 17 % south-west-facing slope, our results show that horizontal installation results in hysteresis in the energy balance closure and errors of up to 25 %. Finally, we propose an approximation to estimate the surface-normal Rn, when only vertical Rn measurements are available.

  14. The Surface Energy Balance System (SEBS for estimation of turbulent heat fluxes

    Directory of Open Access Journals (Sweden)

    Z. Su

    2002-01-01

    Full Text Available A Surface Energy Balance System (SEBS is proposed for the estimation of atmospheric turbulent fluxes and evaporative fraction using satellite earth observation data, in combination with meteorological information at proper scales. SEBS consists of: a set of tools for the determination of the land surface physical parameters, such as albedo, emissivity, temperature, vegetation coverage etc., from spectral reflectance and radiance measurements; a model for the determination of the roughness length for heat transfer; and a new formulation for the determination of the evaporative fraction on the basis of energy balance at limiting cases. Four experimental data sets are used to assess the reliabilities of SEBS. Based on these case studies, SEBS has proven to be capable to estimate turbulent heat fluxes and evaporative fraction at various scales with acceptable accuracy. The uncertainties in the estimated heat fluxes are comparable to in-situ measurement uncertainties. Keywords: Surface energy balance, turbulent heat flux, evaporation, remote sensing

  15. Limits to prediction of energy balance from milk composition measures at individual cow level

    DEFF Research Database (Denmark)

    Løvendahl, P; Ridder, C; Friggens, N C

    2010-01-01

    Frequently updated energy balance (EB) estimates for individual cows are especially useful for dairy herd management, and individual-level estimates form the basis for group-level EB estimates. The accuracy of EB estimates determines the value of this information for management decision support....... This study aimed to assess EB accuracy through ANOVA components and by comparing EB estimates based either on milk composition (EBalMilk) or on body condition score (BCS) and body weight (BW) (EBalBody). Energy balance based on milk composition was evaluated using data in which milk composition was measured...... at each milking. Three breeds (Danish Red, Holstein-Friesian, and Jersey) of cows (299 cows, 623 lactations) in parities 1 to 4 were used. Milk data were smoothed using a rolling local regression. Energy balance based on milk composition was calculated using a partial least squares (PLS) model based...

  16. Energy balance for steam generation system with biomass dryer

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Pedro A.R. [Instituto Superior Politecnico Jose Antonio Echeverria (CUJAE), Ciudad de La Habana (Cuba). Facultad Ingenieria Mecanica]. E-mail: pedro@economia.cujae.edu.cu; Lombardi, Geraldo; Santos, Antonio Moreira dos [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia]. E-mails: lombardi@sc.usp.br; asantos@sc.usp.br

    2008-07-01

    Water content is a major drainer of the energy available in the biomass, which justifies the proposal of a drying system with the potential to increase 80% of the biomass low heating value, also increasing the production of steam in the boiler and cogeneration of electricity. An example of biomass is the sugar cane bagasse of an alcohol mill producing 120,000 liters of alcohol per day, whose humidity from the extraction section is usually 50%. The present paper determines the increases in the mass flow rates of steam in the boiler, in the cogeneration of electricity and in the pay back time of the drying system and of the alcohol mill, as a consequence of the bagasse drying from 50 to 35%, considering 30% of air excess over the stoichiometric value admitted in the boiler for the bagasse burning. It also provides subsidies for the development and deployment of a drying system for the current boilers. (author)

  17. Energy Balance of Bio-ethanol - A Review; Energibalans foer bioetanol - en kunskapsoeversikt

    Energy Technology Data Exchange (ETDEWEB)

    Boerjesson, Paal

    2006-03-15

    This review presents a synthesis of various Swedish and international studies on the bio-ethanol energy balance, and an analysis of how and why their results differ. Other methods, such as exergy- and emergy analysis, are discussed and compared with the energy analysis method. Finally, potential improvements of the energy efficiency in bio-ethanol production are discussed. The energy balance is here expressed as the ratio of the energy content of the fuel to the primary energy input for the entire production cycle of the fuel. The energy balance of ethanol from cereals is, on average, 1.6, and varies between 0.7 and 2.8. Corresponding average figures for ethanol from corn, sugar beets and lignocellulosic biomass (e.g. energy forest) are 1.4, 1.8 and 3.2, respectively. There are several reasons why the energy balances differ between the different studies, even where the feedstock is identical. The sources of differences can be divided between those related to differences in local and geographical conditions, and those related to differences in the methodological approach applied. Depending on the definition of the system that is studied (systems boundaries), and how the energy input is divided between the ethanol and the by-products generated in the process (allocation methods), the energy balance may differ by a factor of 5. Thus, it is impossible to make reliable and fair comparisons between different studies unless all assumptions are clearly presented and defined. Results from exergy- and emergy analysis of bio-ethanol often show significantly different results from those presented in energy analyses. It is, however, not useful to compare these different results since the various methods have different focuses and are answering different questions. The energy balance of cereal-based ethanol can be improved by more efficient cultivation methods, but mainly by improved conversion processes. One possibility is by using bio-refineries where not only ethanol but also

  18. Food and physical activity environments: an energy balance approach for research and practice.

    Science.gov (United States)

    Economos, Christina D; Hatfield, Daniel P; King, Abby C; Ayala, Guadalupe X; Pentz, Mary Ann

    2015-05-01

    Increases in the prevalence of overweight and obesity are a function of chronic, population-level energy imbalance, whereby energy intakes exceed energy expenditures. Although sometimes viewed in isolation, energy intakes and expenditures in fact exist in a dynamic interplay: energy intakes may influence energy expenditures and vice versa. Obesogenic environments that promote positive energy balance play a central role in the obesity epidemic, and reducing obesity prevalence will require re-engineering environments to promote both healthy eating and physical activity. There may be untapped synergies in addressing both sides of the energy balance equation in environmentally focused obesity interventions, yet food/beverage and physical activity environments are often addressed separately. The field needs design, evaluation, and analytic methods that support this approach. This paper provides a rationale for an energy balance approach and reviews and describes research and practitioner work that has taken this approach to obesity prevention at the environmental and policy levels. Future directions in research, practice, and policy include moving obesity prevention toward a systems approach that brings both nutrition and physical activity into interdisciplinary training, funding mechanisms, and clinical and policy recommendations/guidelines.

  19. The effect of breakfast on appetite regulation, energy balance and exercise performance.

    Science.gov (United States)

    Clayton, David J; James, Lewis J

    2016-08-01

    The belief that breakfast is the most important meal of day has been derived from cross-sectional studies that have associated breakfast consumption with a lower BMI. This suggests that breakfast omission either leads to an increase in energy intake or a reduction in energy expenditure over the remainder of the day, resulting in a state of positive energy balance. However, observational studies do not imply causality. A number of intervention studies have been conducted, enabling more precise determination of breakfast manipulation on indices of energy balance. This review will examine the results from these studies in adults, attempting to identify causal links between breakfast and energy balance, as well as determining whether consumption of breakfast influences exercise performance. Despite the associations in the literature, intervention studies have generally found a reduction in total daily energy intake when breakfast is omitted from the daily meal pattern. Moreover, whilst consumption of breakfast supresses appetite during the morning, this effect appears to be transient as the first meal consumed after breakfast seems to offset appetite to a similar extent, independent of breakfast. Whether breakfast affects energy expenditure is less clear. Whilst breakfast does not seem to affect basal metabolism, breakfast omission may reduce free-living physical activity and endurance exercise performance throughout the day. In conclusion, the available research suggests breakfast omission may influence energy expenditure more strongly than energy intake. Longer term intervention studies are required to confirm this relationship, and determine the impact of these variables on weight management.

  20. National Assessment of Energy Storage for Grid Balancing and Arbitrage: Phase 1, WECC

    Energy Technology Data Exchange (ETDEWEB)

    Kintner-Meyer, Michael CW; Balducci, Patrick J.; Colella, Whitney G.; Elizondo, Marcelo A.; Jin, Chunlian; Nguyen, Tony B.; Viswanathan, Vilayanur V.; Zhang, Yu

    2012-06-01

    To examine the role that energy storage could play in mitigating the impacts of the stochastic variability of wind generation on regional grid operation, the Pacific Northwest National Laboratory (PNNL) examined a hypothetical 2020 grid scenario in which additional wind generation capacity is built to meet renewable portfolio standard targets in the Western Interconnection. PNNL developed a stochastic model for estimating the balancing requirements using historical wind statistics and forecasting error, a detailed engineering model to analyze the dispatch of energy storage and fast-ramping generation devices for estimating size requirements of energy storage and generation systems for meeting new balancing requirements, and financial models for estimating the life-cycle cost of storage and generation systems in addressing the future balancing requirements for sub-regions in the Western Interconnection. Evaluated technologies include combustion turbines, sodium sulfur (Na-S) batteries, lithium ion batteries, pumped-hydro energy storage, compressed air energy storage, flywheels, redox flow batteries, and demand response. Distinct power and energy capacity requirements were estimated for each technology option, and battery size was optimized to minimize costs. Modeling results indicate that in a future power grid with high-penetration of renewables, the most cost competitive technologies for meeting balancing requirements include Na-S batteries and flywheels.

  1. An update on Earth's energy balance in light of the latest global observations

    Science.gov (United States)

    Stephens, Graeme L.; Li, Juilin; Wild, Martin; Clayson, Carol Anne; Loeb, Norman; Kato, Seiji; L'Ecuyer, Tristan; Stackhouse, Paul W.; Lebsock, Matthew; Andrews, Timothy

    2012-10-01

    Climate change is governed by changes to the global energy balance. At the top of the atmosphere, this balance is monitored globally by satellite sensors that provide measurements of energy flowing to and from Earth. By contrast, observations at the surface are limited mostly to land areas. As a result, the global balance of energy fluxes within the atmosphere or at Earth's surface cannot be derived directly from measured fluxes, and is therefore uncertain. This lack of precise knowledge of surface energy fluxes profoundly affects our ability to understand how Earth's climate responds to increasing concentrations of greenhouse gases. In light of compilations of up-to-date surface and satellite data, the surface energy balance needs to be revised. Specifically, the longwave radiation received at the surface is estimated to be significantly larger, by between 10 and 17 Wm-2, than earlier model-based estimates. Moreover, the latest satellite observations of global precipitation indicate that more precipitation is generated than previously thought. This additional precipitation is sustained by more energy leaving the surface by evaporation -- that is, in the form of latent heat flux -- and thereby offsets much of the increase in longwave flux to the surface.

  2. Mobility-Aware and Load Balancing Based Clustering Algorithm for Energy Conservation in MANET

    Institute of Scientific and Technical Information of China (English)

    XU Li; ZHENG Bao-yu; GUO Gong-de

    2005-01-01

    Mobile ad hoc network (MANET) is one of wireless communication network architecture that has received a lot of attention. MANET is characterized by dynamic network topology and limited energy. With mobility-aware and load balancing based clustering algorithm (MLCA), this paper proposes a new topology management strategy to conserve energy. Performance simulation results show that the proposed MLCA strategy can balances the traffic load inside the whole network, so as to prolong the network lifetime, meanly, at the same time, achieve higher throughput ratio and network stability.

  3. Daily magnesium fluxes regulate cellular timekeeping and energy balance.

    Science.gov (United States)

    Feeney, Kevin A; Hansen, Louise L; Putker, Marrit; Olivares-Yañez, Consuelo; Day, Jason; Eades, Lorna J; Larrondo, Luis F; Hoyle, Nathaniel P; O'Neill, John S; van Ooijen, Gerben

    2016-04-21

    Circadian clocks are fundamental to the biology of most eukaryotes, coordinating behaviour and physiology to resonate with the environmental cycle of day and night through complex networks of clock-controlled genes. A fundamental knowledge gap exists, however, between circadian gene expression cycles and the biochemical mechanisms that ultimately facilitate circadian regulation of cell biology. Here we report circadian rhythms in the intracellular concentration of magnesium ions, [Mg(2+)]i, which act as a cell-autonomous timekeeping component to determine key clock properties both in a human cell line and in a unicellular alga that diverged from each other more than 1 billion years ago. Given the essential role of Mg(2+) as a cofactor for ATP, a functional consequence of [Mg(2+)]i oscillations is dynamic regulation of cellular energy expenditure over the daily cycle. Mechanistically, we find that these rhythms provide bilateral feedback linking rhythmic metabolism to clock-controlled gene expression. The global regulation of nucleotide triphosphate turnover by intracellular Mg(2+) availability has potential to impact upon many of the cell's more than 600 MgATP-dependent enzymes and every cellular system where MgNTP hydrolysis becomes rate limiting. Indeed, we find that circadian control of translation by mTOR is regulated through [Mg(2+)]i oscillations. It will now be important to identify which additional biological processes are subject to this form of regulation in tissues of multicellular organisms such as plants and humans, in the context of health and disease.

  4. Regional energy balance in rat brain after transient forebrain ischemia.

    Science.gov (United States)

    Pulsinelli, W A; Duffy, T E

    1983-05-01

    Phosphocreatine, ATP, and glucose were severely depleted, and the lactate levels were increased in the paramedian neocortex, dorsal-lateral striatum, and CA1 zone of hippocampus of rats exposed to 30 min of forebrain ischemia. Upon recirculation of the brain, phosphocreatine, ATP, and lactate concentrations recovered to control values in the paramedian neocortex and CA1 zone of hippocampus and to near-control values in the striatum. The phosphocreatine and ATP concentrations then fell and the lactate levels rose in the striatum after 6-24 h, and in the CA1 zone of hippocampus after 24-72 h. The initial recovery and subsequent delayed changes in the phosphocreatine, ATP, and lactate concentrations in the striatum and hippocampus coincided with the onset and progression of morphological injury in these brain regions. The results suggest that cells in these regions regain normal or near-normal mitochondrial function and are viable, in terms of energy production, for many hours before unknown mechanisms cause irreversible neuronal before unknown mechanisms cause irreversible neuronal injury.

  5. Energy balance model of a SOFC cogenerator operated with biogas

    Science.gov (United States)

    Van herle, Jan; Maréchal, F.; Leuenberger, S.; Favrat, D.

    A small cogeneration system based on a Solid Oxide Fuel Cell (SOFC) fed on the renewable energy source biogas is presented. An existing farm biogas production site (35 m 3 per day), currently equipped with a SOFC demonstration stack, is taken for reference. A process flow diagram was defined in a software package allowing to vary system operating parameters like the fuel inlet composition, reforming technology, stack temperature and stack current (or fuel conversion). For system reforming simplicity, a base case parameter set was defined as the fuel inlet of 60% CH 4:40% CO 2 mixed with air in a 1:1 ratio, together with 800 °C operating temperature and 80% fuel conversion. A model stack, consisting of 100 series elements of anode supported electrolyte cells of 100 cm 2 each, was calculated to deliver 3.1 kW el and 5.16 kW th from an input of 1.5 N m 3/h of biogas (8.95 kW LHV), corresponding to 33.8 and 57.6% electrical and thermal efficiencies (Lower Heating Values (LHVs)), respectively. The incidence on the efficiencies of the model system was examined by the variation of a number of parameters such as the CO 2 content in the biogas, the amount of air addition to the biogas stream, the addition of steam to the fuel inlet, the air excess ratio λ and the stack operating temperature, and the results discussed.

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

    Indian Academy of Sciences (India)

    T N Krishnamurti; Mrinal K Biswas

    2006-04-01

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

  7. Energy balance of a laser ablation plume expanding in a background gas

    DEFF Research Database (Denmark)

    Amoruso, Salvatore; Schou, Jørgen; Lunney, James G.

    2010-01-01

    The energy balance of a laser ablation plume in an ambient gas for nanosecond pulses has been investigated on the basis of the model of Predtechensky and Mayorov (PM), which provides a relatively simple and clear description of the essential hydrodynamics. This approach also leads to an insightful...... description in dimensionless units of how the initial kinetic energy of the plume is dissipated into kinetic and thermal energy of the background gas. Eventually when the plume has stopped, the initial kinetic energy of the plume is converted into thermal energy of the plume and background gas....

  8. Automatic Generation Control Strategy Based on Balance of Daily Electric Energy

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    An automatic generation control strategy based on balance of daily total electric energy is put forward. It makes the balance between actual total generated energy controlled by automatic generation system and planned total energy on base of area control error, and makes the actual 24-hour active power load curve to approach the planned load curve. The generated energy is corrected by velocity weighting factor so that it conducts dynamic regulation and reaches the speed of response. Homologous strategy is used according to the real-time data in the operation of automatic generation control. Results of simulation are perfect and power energy compensation control with ideal effect can be achieved in the particular duration.

  9. Provisional energy balance-sheet of France in 1999; Bilan energetique provisoire de la France en 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This document presents a first and provisional analysis of the energy balance-sheet in France during the year 1999. the main conclusions concern: the energy mastership, the primary energy consumption, the energy intensity, the climatic conditions, the nuclear energy production, the energy independence, the carbon dioxide emissions and the energy bill. Many tables and charts are provided. (A.L.B.)

  10. Wireless Meter Reading Based Energy-Balanced Steady Clustering Routing Algorithm for Sensor Networks

    Directory of Open Access Journals (Sweden)

    TANG, Z.

    2011-05-01

    Full Text Available According to the characteristics of wireless meter reading system, an energy-balanced and energy-efficient steady clustering routing algorithm (EBSC, Energy-Balanced Steady Clustering is proposed. In the clustering mechanism, the current cluster head nodes determine cluster head nodes for next round according to the residual energy of the cluster members. In the next round, each non-cluster head node decides the cluster to which it will belong according to energy-distance function. The cluster head nodes send data to base station by the communication model of single hop and multi-hop that is decided according to the criterion of minimum energy consumption. In EBSC algorithm, the number of cluster head nodes generated in each round is very steady, and EBSC combines the advantage both distributed and centralized clustering algorithm. Experimental results show that the proposed routing algorithm not only efficiently uses limited energy of network nodes, but also well balances energy consumption of all nodes, and significantly prolongs network lifetime.

  11. Energy balance, body composition, sedentariness and appetite regulation: pathways to obesity.

    Science.gov (United States)

    Hopkins, Mark; Blundell, John E

    2016-09-01

    Energy balance is not a simple algebraic sum of energy expenditure and energy intake as often depicted in communications. Energy balance is a dynamic process and there exist reciprocal effects between food intake and energy expenditure. An important distinction is that of metabolic and behavioural components of energy expenditure. These components not only contribute to the energy budget directly, but also by influencing the energy intake side of the equation. It has recently been demonstrated that resting metabolic rate (RMR) is a potential driver of energy intake, and evidence is accumulating on the influence of physical activity (behavioural energy expenditure) on mechanisms of satiety and appetite control. These effects are associated with changes in leptin and insulin sensitivity, and in the plasma levels of gastrointestinal (GI) peptides such as glucagon-like peptide-1 (GLP-1), ghrelin and cholecystokinin (CCK). The influence of fat-free mass on energy expenditure and as a driver of energy intake directs attention to molecules emanating from skeletal tissue as potential appetite signals. Sedentariness (physical inactivity) is positively associated with adiposity and is proposed to be a source of overconsumption and appetite dysregulation. The molecular signals underlying these effects are not known but represent a target for research.

  12. Energy balance in the watershed of Ipê, Northwestern São Paulo State, Brazil

    Science.gov (United States)

    Feitosa, Diego G.; T. Hernandez, Fernando B.; Franco, Renato A. M.; Teixeira, Antonio H. C.; Neale, Christopher M.

    2016-10-01

    The region of Ilha Solteira, in the Northwestern of São Paulo State, has been undergoing significant changes in agricultural land use and cover since 2006, as pasture fields have been replaced by sugarcane crop. This drastic change can lead to a disturbance in the energy balance, affecting the local climate. The aim of this paper was to assess some parameters related to the energy balance of Ipê's watershed, that changed since no sugarcane cultivation in 2006 to 2,164 hectares in 2011, occupying 31% of the catchment area with this important energy crop for the economy and the environment of Brazil. This study was carried out using remote sensing combined with weather data and using the SAFER (Simple Algorithm for Retrieving Evapotranspiration) model applied in 9 Landsat images collected between 2003 and 2011. The results showed a wide variation between the components of energy balance and when considering only the sugarcane crop were verified the increase values of ETa (Actual Evapotranspiration), H/Rn (Sensible Heat Flux/Net Radiation), TS (Surface Temperature), Rl↑ (Emitted longwave), Rl↓ (Incidente longwave) and surface albedo after the sugarcane production over these years. On the other hand, the NDVI, λE/Rn (Latent Heat Flux/Net Radiation) and Rn values (data) decreased in the same period. Also there was satisfactory correlation between NDVI and ETa. The SAFER model showed satisfactory results for studies of energy balance applied in the Northwestern of São Paulo State.

  13. Our stolen figures: the interface of sexual differentiation, endocrine disruptors, maternal programming, and energy balance.

    Science.gov (United States)

    Schneider, Jill E; Brozek, Jeremy M; Keen-Rhinehart, Erin

    2014-06-01

    This article is part of a Special Issue "Energy Balance". The prevalence of adult obesity has risen markedly in the last quarter of the 20th century and has not been reversed in this century. Less well known is the fact that obesity prevalence has risen in domestic, laboratory, and feral animals, suggesting that all of these species have been exposed to obesogenic factors present in the environment. This review emphasizes interactions among three biological processes known to influence energy balance: Sexual differentiation, endocrine disruption, and maternal programming. Sexual dimorphisms include differences between males and females in body weight, adiposity, adipose tissue distribution, ingestive behavior, and the underlying neural circuits. These sexual dimorphisms are controlled by sex chromosomes, hormones that masculinize or feminize adult body weight during perinatal development, and hormones that act during later periods of development, such as puberty. Endocrine disruptors are natural and synthetic molecules that attenuate or block normal hormonal action during these same developmental periods. A growing body of research documents effects of endocrine disruptors on the differentiation of adipocytes and the central nervous system circuits that control food intake, energy expenditure, and adipose tissue storage. In parallel, interest has grown in epigenetic influences, including maternal programming, the process by which the mother's experience has permanent effects on energy-balancing traits in the offspring. This review highlights the points at which maternal programming, sexual differentiation, and endocrine disruption might dovetail to influence global changes in energy balancing traits.

  14. Skeletal muscle responses to negative energy balance: effects of dietary protein.

    Science.gov (United States)

    Carbone, John W; McClung, James P; Pasiakos, Stefan M

    2012-03-01

    Sustained periods of negative energy balance decrease body mass due to losses of both fat and skeletal muscle mass. Decreases in skeletal muscle mass are associated with a myriad of negative consequences, including suppressed basal metabolic rate, decreased protein turnover, decreased physical performance, and increased risk of injury. Decreases in skeletal muscle mass in response to negative energy balance are due to imbalanced rates of muscle protein synthesis and degradation. However, the underlying physiological mechanisms contributing to the loss of skeletal muscle during energy deprivation are not well described. Recent studies have demonstrated that consuming dietary protein at levels above the current recommended dietary allowance (0.8 g · kg(-1) · d(-1)) may attenuate the loss of skeletal muscle mass by affecting the intracellular regulation of muscle anabolism and proteolysis. However, the specific mechanism by which increased dietary protein spares skeletal muscle through enhanced molecular control of muscle protein metabolism has not been elucidated. This article reviews the available literature related to the effects of negative energy balance on skeletal muscle mass, highlighting investigations that assessed the influence of varying levels of dietary protein on skeletal muscle protein metabolism. Further, the molecular mechanisms that may contribute to the regulation of skeletal muscle mass in response to negative energy balance and alterations in dietary protein level are described.

  15. Negative energy balance increases periprandial ghrelin and growth hormone concentrations in lactating dairy cows.

    Science.gov (United States)

    Bradford, Barry J; Allen, Michael S

    2008-02-01

    The reported effects of feeding on growth hormone (GH) secretion in ruminants have been inconsistent, and are likely influenced by energy status of animals. High-producing dairy cows in early lactation and late lactation were used to assess the effects of energy balance on temporal variation of plasma metabolites and hormones. Cows were fed a single diet once daily, and feed was withdrawn for 90 min prior to feeding. Beginning at the time of feed withdrawal, plasma samples were collected via jugular catheters hourly for 24h. Concentrations of non-esterified fatty acids and GH were measured for all samples, while insulin, glucose, and acylated (active) ghrelin were quantified for four sample times around feeding. As expected, calculated energy balance was significantly lower in early lactation than late lactation cows (-43.5 MJ retained/day versus 7.2 MJ retained/day). Following the primary meal of the day, a GH surge was observed in early lactation but not in late lactation cows. This difference was not explained by temporal patterns in non-esterified fatty acid, insulin, or glucose concentrations. However, a preprandial ghrelin surge was observed in early lactation only, suggesting that ghrelin was responsible for the prandial GH surge in this group. Results of a stepwise regression statistical analysis showed that both preprandial ghrelin concentration and energy balance were significant predictors of prandial GH increase over baseline. Adaptations to negative energy balance in lactating dairy cattle likely include enhanced ghrelin secretion and greater GH response to ghrelin.

  16. Dry period plane of energy: Effects on feed intake, energy balance, milk production, and composition in transition dairy cows.

    Science.gov (United States)

    Mann, S; Yepes, F A Leal; Overton, T R; Wakshlag, J J; Lock, A L; Ryan, C M; Nydam, D V

    2015-05-01

    The objective was to investigate the effect of different dry cow feeding strategies on the degree of ketonemia postpartum. Epidemiologic studies provide evidence of an association between elevated β-hydroxybutyrate (BHBA) concentrations in postpartum dairy cows and a decreased risk for reproductive success as well as increased risk for several diseases in early lactation, such as displacement of the abomasum and metritis. The plane of energy fed to cows in the prepartum period has been shown to influence ketogenesis and the degree of negative energy balance postpartum. Our hypothesis was that a high-fiber, controlled-energy diet (C) fed during the dry period would lead to a lower degree of hyperketonemia in the first weeks postpartum compared with either a high-energy diet (H), or a diet where an intermediate level of energy would only be fed in the close-up period (starting at 28d before expected parturition), following the same controlled-energy diet in the far-off period. Hyperketonemia in this study was defined as a blood BHBA concentration of ≥1.2mmol/L. Holstein cows (n=84) entering parity 2 or greater were enrolled using a randomized block design and housed in individual tiestalls. All treatment diets were fed for ad libitum intake and contained monensin. Cows received the same fresh cow ration after calving. Blood samples were obtained 3 times weekly before and after calving and analyzed for BHBA and nonesterified fatty acids (NEFA). Milk components, production, and dry matter intake were recorded and energy balance was calculated. Repeated measures ANOVA was conducted for the outcomes dry matter intake, energy balance, BHBA and NEFA concentrations, milk and energy-corrected milk yield, as well as milk composition. Predicted energy balance tended to be less negative postpartum in group C and cows in this group had fewer episodes of hyperketonemia compared with both the intermediate group and group H in the first 3 wk after calving. Postpartum BHBA and

  17. China's energy statistics in a global context: A methodology to develop regional energy balances for East, Central and West China

    DEFF Research Database (Denmark)

    Mischke, Peggy

    2013-01-01

    for research and policy analysis. An improved understanding of the quality and reliability of Chinese economic and energy data is becoming more important to to understanding global energy markets and future greenhouse gas emissions. China’s national statistical system to track such changes is however still...... developing and, in some instances, energy data remain unavailable in the public domain. This working paper discusses China’s energy and economic statistics in view of identifying suitable indicators to develop a simplified regional energy systems for China from a variety of publicly available data. As China......’s national statistical system continuous to be debated and criticised in terms of data quality, comparability and reliability, an overview of the milestones, status and main issues of China’s energy statistics is given. In a next step, the energy balance format of the International Energy Agency is used...

  18. Energy balance in the solar transition region. II - Effects of pressure and energy input on hydrostatic models

    Science.gov (United States)

    Fontenla, J. M.; Avrett, E. H.; Loeser, R.

    1991-01-01

    The radiation of energy by hydrogen lines and continua in hydrostatic energy-balance models of the transition region between the solar chromosphere and corona is studied using models which assume that mechanical or magnetic energy is dissipated in the hot corona and is then transported toward the chromosphere down the steep temperature gradient of the transition region. These models explain the average quiet sun and also the entire range of variability of the Ly-alpha lines. The relations between the downward energy flux, the pressure of the transition region, and the different hydrogen emission are described.

  19. Balanced energy-efficient relay selection scheme in wireless mobile relay networks

    Institute of Scientific and Technical Information of China (English)

    Liu Wei; Ji Hong; Li Xi

    2010-01-01

    In order to resolve the relay selection problem in wireless mobile relay networks (WMRNs), a novel balanced energy-efficient mobile relay selection scheme is proposed in this paper.Compared with traditional counter-based algorithm, distance and energy consumption are considered from network respect to provide a better network lifetime performance in the proposed scheme.Also, it performs well when nodes move freely at high speed.A random assessment delay (RAD) mechanism is added to avoid collisions and improve transmission efficiency.Simulation results reveal that, the proposed scheme has advantages in prolonging network lifetime, balancing energy consumption and reducing the total energy consumption compared with existing counter-based scheme.

  20. How to do an energy balance in the PRESENCE of chemical reaction - Part 1

    OpenAIRE

    Fernandez-Torres, Maria J.

    2013-01-01

    A solved example for the determination of the increment in enthalpy for the energy balances for open systems in the context of chemical engineering is presented. The example shows how to tackle this kind of problems when it has been decided not to make use of the enthalpy of the reaction. The substances elements will be used as reference state.

  1. How to do an energy balance in the PRESENCE of chemical reaction - part 2

    OpenAIRE

    Fernandez-Torres, Maria J.

    2013-01-01

    A solved example for the determination of the increment in enthalpy for the energy balances for open systems in the context of chemical engineering is presented. The example shows how to tackle this kind of problems when it has been decided to make use of the enthalpy of the reaction.

  2. Using Sensewear armband and diet journal to promote adolescents' energy balance knowledge and motivation

    Directory of Open Access Journals (Sweden)

    Senlin Chen

    2014-12-01

    Conclusion: Tracking EB using the SWA and diet journal is motivating but has limited efficacy in promoting adolescents' EB knowledge. Using these two tools as educational technology in conjunction with a focused, systematic, and educational approach has the potential to leverage adolescents' EB knowledge, motivation, as well as behaviors for living an energy-balanced lifestyle.

  3. Comparison of four different energy balance models for estimating evapotranspiration in the Midwestern United States

    Science.gov (United States)

    Singh, Ramesh K.; Senay, Gabriel B.

    2016-01-01

    The development of different energy balance models has allowed users to choose a model based on its suitability in a region. We compared four commonly used models—Mapping EvapoTranspiration at high Resolution with Internalized Calibration (METRIC) model, Surface Energy Balance Algorithm for Land (SEBAL) model, Surface Energy Balance System (SEBS) model, and the Operational Simplified Surface Energy Balance (SSEBop) model—using Landsat images to estimate evapotranspiration (ET) in the Midwestern United States. Our models validation using three AmeriFlux cropland sites at Mead, Nebraska, showed that all four models captured the spatial and temporal variation of ET reasonably well with an R2 of more than 0.81. Both the METRIC and SSEBop models showed a low root mean square error (0.80), whereas the SEBAL and SEBS models resulted in relatively higher bias for estimating daily ET. The empirical equation of daily average net radiation used in the SEBAL and SEBS models for upscaling instantaneous ET to daily ET resulted in underestimation of daily ET, particularly when the daily average net radiation was more than 100 W·m−2. Estimated daily ET for both cropland and grassland had some degree of linearity with METRIC, SEBAL, and SEBS, but linearity was stronger for evaporative fraction. Thus, these ET models have strengths and limitations for applications in water resource management.

  4. Across-phase biomass pyrolysis stoichiometry, energy balance, and product formation kinetics

    Science.gov (United States)

    Predictive correlations between reactions occurring in the gas-, liquid- and solid-phases are necessary to economically utilize the thermochemical conversion of agricultural wastes impacting the food, water, and energy nexus. On the basis of an empirical mass balance (99.7%), this study established...

  5. Surface energy balance, melt and sublimation at Neumayer Station, East Antarctica

    NARCIS (Netherlands)

    van den Broeke, M.R.; König-Langlo, G.; Picard, G.; Kuipers Munneke, P.; Lenaerts, J.T.M.

    2009-01-01

    A surface energy balance model is forced by 13 years of high-quality hourly observations from the Antarctic coastal station Neumayer. The model accurately reproduces observed surface temperatures. Surface sublimation is significant in summer, when absorbed solar radiation heats the surface. Includin

  6. A high performance GPU implementation of Surface Energy Balance System (SEBS) based on CUDA-C

    NARCIS (Netherlands)

    Abouali, Mohammad; Timmermans, Joris; Castillo, Jose E.; Su, Bob Z.

    2013-01-01

    This paper introduces a new implementation of the Surface Energy Balance System (SEBS) algorithm harnessing the many cores available on Graphics Processing Units (GPUs). This new implementation uses Compute Unified Device Architecture C (CUDA-C) programming model and is designed to be executed on a

  7. Comparison of Four Different Energy Balance Models for Estimating Evapotranspiration in the Midwestern United States

    Directory of Open Access Journals (Sweden)

    Ramesh K. Singh

    2015-12-01

    Full Text Available The development of different energy balance models has allowed users to choose a model based on its suitability in a region. We compared four commonly used models—Mapping EvapoTranspiration at high Resolution with Internalized Calibration (METRIC model, Surface Energy Balance Algorithm for Land (SEBAL model, Surface Energy Balance System (SEBS model, and the Operational Simplified Surface Energy Balance (SSEBop model—using Landsat images to estimate evapotranspiration (ET in the Midwestern United States. Our models validation using three AmeriFlux cropland sites at Mead, Nebraska, showed that all four models captured the spatial and temporal variation of ET reasonably well with an R2 of more than 0.81. Both the METRIC and SSEBop models showed a low root mean square error (<0.93 mm·day−1 and a high Nash–Sutcliffe coefficient of efficiency (>0.80, whereas the SEBAL and SEBS models resulted in relatively higher bias for estimating daily ET. The empirical equation of daily average net radiation used in the SEBAL and SEBS models for upscaling instantaneous ET to daily ET resulted in underestimation of daily ET, particularly when the daily average net radiation was more than 100 W·m−2. Estimated daily ET for both cropland and grassland had some degree of linearity with METRIC, SEBAL, and SEBS, but linearity was stronger for evaporative fraction. Thus, these ET models have strengths and limitations for applications in water resource management.

  8. Replacing fossil based PET with biobased PEF; proess analysis, energy and GHG balance

    NARCIS (Netherlands)

    Eerhart, A.J.J.E.; Faaij, A.P.C.; Patel, M.K.

    2012-01-01

    An energy and greenhouse gas (GHG) balance study was performed on the production of the bioplastic polyethylene furandicarboxylate (PEF) starting from corn based fructose. The goal of the study was to analyze and to translate experimental data on the catalytic dehydration of fructose to a simulation

  9. Process evaluation of a workplace health promotion intervention aimed at improving work engagement and energy balance

    NARCIS (Netherlands)

    Berkel, J. van; Boot, C.R.L.; Proper, K.I.; Bongers, P.M.; Beek, A.J. van der

    2013-01-01

    OBJECTIVE:: To evaluate the process of the implementation of an intervention aimed at improving work engagement and energy balance, and to explore associations between process measures and compliance. METHODS:: Process measures were assessed using a combination of quantitative and qualitative method

  10. Comparing demand and consumption. A realistic energy balance; Abgleich von Bedarf und Verbrauch. Realistische Energiebilanz

    Energy Technology Data Exchange (ETDEWEB)

    Jagnow, Kati [Ingenieurbuero fuer Energieberatung, Braunschweig (Germany); Wolff, Dieter [Ostfalia Hochschule fuer Angewandte Wissenschaften, Braunschweig/Wolfenbuettel (Germany)

    2010-07-01

    The new appendix 1 of DIN V 18599 is to help users of the standard to either establish a realistic energy balance or - optimally - even to be able to match the calculated heat demand to the measured real consumption data. (orig.)

  11. The Surface Energy Balance System(sebs) For Estimating Energy Balance At Regional Scale - A Validation Using Atsr and Scintillometer Measurements and Racmo Pbl Variables

    Science.gov (United States)

    Jia, L.; Su, Z.; van den Hurk, B.; Moene, A. F.; Menenti, M.

    The estimation of atmospheric turbulent fluxes at the land surface has long been rec- ognized as the most important process in the determination of the exchanges of energy and mass among hydrosphere, atmosphere and biosphere. Remote sensing is probably the only technique which can provide representative measurements of several relevant physical parameters at scales from a point to a continent. Techniques using remote sensing information to estimate atmospheric turbulent fluxes are therefore essential when dealing with processes that can not be represented only by point measurements. In this contribution the Surface Energy Balance System (SEBS) for the estimation of atmospheric turbulent fluxes using satellite earth observation data are evaluated with measurements of sensible heat fluxes by scintillometry. SEBS as proposed here consists of: 1) a set of tools for the determination of the land surface physical param- eters, such as albedo, emissivity, temperature, vegetation coverage etc. from spectral reflectance and radiance of ATSR-2 measurements; 2) an extended model for the de- termination of the roughness length for heat transfer; 3) and a new formulation for the determination of the evaporative fraction on the basis of energy balance at lim- iting cases. The input to SEBS are ATSR derived surface physical variables and at- mospheric boundary layer variables derived from the mesoscale atmospheric model RACMO. The SEBS estimates are satisfactory when evaluated over three different land surface areas with dry, small irrigated and larger irrigated surface situations re- spectively.

  12. The energy balance of utilising meadow grass in Danish biogas production

    DEFF Research Database (Denmark)

    Meyer, Ane Katharina Paarup; Raju, Chitra Sangaraju; Kucheryavskiy, Sergey V.;

    2015-01-01

    This paper presents a study of the energy balance of utilising nature conservation biomass from meadow habitats in Danish biogas production. Utilisation of nature conservation grass in biogas production in Denmark represents an interesting perspective for enhancing nature conservation of the open...... of meadow areas, different relevant geo-datasets, spatial analyses, and various statistical analyses. The results show that values for the energy return on energy invested (EROEI) ranging from 1.7 to 3.3 can be obtained when utilising meadow grasses in local biogas production. The total national net energy...

  13. BALANCE OF ENERGY AND COMPONENTS OF VOLTAGE DURING THE ELECTROTECHNICAL MODIFICATION OF PHYSICOCHEMICAL PARAMETERS OF WATER

    Directory of Open Access Journals (Sweden)

    Stiopka O.G

    2006-04-01

    Full Text Available The paper is dealing with results of theoretical and experimental investigations related to the balance of energy and voltage distribution in units for electrochemical units for water treatment. The electrical energy conversion mechanism in electrochemical units equipped with ionic selective membrane is analyzed. The obtained results could be used for design of electrochemical units for the water conditioning for diverse technological processes in agriculture and biotechnology.

  14. Distributed energy balance modeling of South Cascade Glacier, Washington and assessment of model uncertainty

    Science.gov (United States)

    Anslow, Faron S.; Hostetler, S.; Bidlake, W.R.; Clark, P.U.

    2008-01-01

    We have developed a physically based, distributed surface energy balance model to simulate glacier mass balance under meteorological and climatological forcing. Here we apply the model to estimate summer ablation on South Cascade Glacier, Washington, for the 2004 and 2005 mass balance seasons. To arrive at optimal mass balance simulations, we investigate and quantify model uncertainty associated with selecting from a range of physical parameter values that are not commonly measured in glaciological mass balance field studies. We optimize the performance of the model by varying values for atmospheric transmissivity, the albedo of surrounding topography, precipitation-elevation lapse rate, surface roughness for turbulent exchange of momentum, and snow albedo aging coefficient. Of these the snow aging parameter and precipitation lapse rates have the greatest influence on the modeled ablation. We examined model sensitivity to varying parameters by performing an additional 103 realizations with parameters randomly chosen over a ??5% range centered about the optimum values. The best fit suite of model parameters yielded a net balance of -1.69??0.38 m water equivalent (WE) for the 2004 water year and -2.10??0.30 m WE up to 11 September 2005. The 2004 result is within 3% of the measured value. These simulations account for 91% and 93% of the variance in measured ablation for the respective years. Copyright 2008 by the American Geophysical Union.

  15. Effects of zonal flows on correlation between energy balance and energy conservation associated with nonlinear nonviscous atmospheric dynamics in a thin rotating spherical shell

    Science.gov (United States)

    Ibragimov, Ranis N.

    2016-12-01

    The nonlinear Euler equations are used to model two-dimensional atmosphere dynamics in a thin rotating spherical shell. The energy balance is deduced on the basis of two classes of functorially independent invariant solutions associated with the model. It it shown that the energy balance is exactly the conservation law for one class of the solutions whereas the second class of invariant solutions provides and asymptotic convergence of the energy balance to the conservation law.

  16. World Energy Balance Outlook and OPEC Production Capacity: Implications for Global Oil Security

    Directory of Open Access Journals (Sweden)

    Azadeh M. Rouhani

    2012-07-01

    Full Text Available The imbalance between energy resource availability, demand, and production capacity, coupled with inherent economic and environmental uncertainties make strategic energy resources planning, management, and decision-making a challenging process. In this paper, a descriptive approach has been taken to synthesize the world’s energy portfolio and the global energy balance outlook in order to provide insights into the role of Organization of Petroleum Exporting Countries (OPEC in maintaining “stability” and “balance” of the world’s energy market. This synthesis illustrates that in the absence of stringent policies, i.e., if historical trends of the global energy production and consumption hold into the future, it is unlikely that non-conventional liquid fuels and renewable energy sources will play a dominant role in meeting global energy demand by 2030. This should be a source of major global concern as the world may be unprepared for an ultimate shift to other energy sources when the imminent peak oil production is reached. OPEC’s potential to impact the supply and price of oil could enable this organization to act as a facilitator or a barrier for energy transition policies, and to play a key role in the global energy security through cooperative or non-cooperative strategies. It is argued that, as the global energy portfolio becomes more balanced in the long run, OPEC may change its typical high oil price strategies to drive the market prices to lower equilibria, making alternative energy sources less competitive. Alternatively, OPEC can contribute to a cooperative portfolio management approach to help mitigate the gradually emerging energy crisis and global warming, facilitating a less turbulent energy transition path while there is time.

  17. Analysis of the energy balance closure over a FLUXNET boreal forest in Finland

    Directory of Open Access Journals (Sweden)

    J. M. Sánchez

    2010-08-01

    Full Text Available The imbalance in the surface energy budget, when using eddy-covariance techniques to measure turbulent fluxes, is still an unresolved problem. Important progresses have been reported in recent years identifying potential reasons for this lack of energy balance closure. In this paper we focus on the data collected in a FLUXNET boreal forest site in Sodankylä, Finland. Using one month half-hourly data, an average Energy Balance Ratio (EBR of 0.72 is obtained. The inclusion of the heat storage terms in the energy budget yields an improvement of about 6% in the total closure. The sensitivity of the energy balance closure to the turbulence intensity is analysed in terms of the friction velocity, and atmospheric stability/instability conditions. Significant better closure is obtained for high values of the friction velocity and unstable conditions. The mismatch in variable footprints for different fluxes is checked by analysing the dependence of the closure on wind direction. The inhomogeneities of the emplacement surrounding the flux tower induce a critical decrease in the EBR of up to 30% for specific wind directions. After filtering all unfavourable conditions, EBR=0.94. This is a reasonable good result for the energy balance closure. However there is still a 6% of the available energy unaccounted. Part of this remaining imbalance could be justified as the impossibility of the 30 min averaging time to capture the low frequency flux contributions, since the closure is improved by a 5% when the averaging time is expanded to 2 h.

  18. Analysis of the energy balance closure over a FLUXNET boreal forest in Finland

    Directory of Open Access Journals (Sweden)

    J. M. Sánchez

    2010-05-01

    Full Text Available The imbalance in the surface energy budget, when using eddy-covariance techniques to measure turbulent fluxes, is still an unresolved problem. Important progresses have been reported in recent years identifying potential reasons for this lack of energy balance closure. In this paper we focus on the data collected in a FLUXNET boreal forest site in Sodankylä, Finland. Using one month half-hourly data, an average Energy Balance Ratio (EBR of 0.72 is obtained. The inclusion of the heat storage terms in the energy budget yields an improvement of about 6% in the total closure. The sensitivity of the energy balance closure to the turbulence intensity is analysed in terms of the friction velocity, and atmospheric stability/instability conditions. Significant better closure is obtained for high values of the friction velocity and unstable conditions. The mismatch in variable footprints for different fluxes is checked by analysing the dependence of the closure on wind direction. The inhomogeneities of the emplacement surrounding the flux tower induce a critical decrease in the EBR of up to 30% for specific wind directions. After filtering all unfavourable conditions, EBR=0.94. This is a reasonable good result for the energy balance closure. However there is still a 6% of the available energy unaccounted. Part of this remaining imbalance could be justified as the impossibility of the 30 min averaging time to capture the low frequency flux contributions, since the closure is improved by a 5% when the averaging time is expanded to 2 h.

  19. Effect of balanced protein energy supplementation during pregnancy on birth outcomes

    Directory of Open Access Journals (Sweden)

    Bhutta Zulfiqar A

    2011-04-01

    Full Text Available Abstract Background The nutritional status of the mother prior to and during pregnancy plays a vital role in fetal growth and development, and maternal undernourishment may lead to adverse perinatal outcomes including intrauterine growth restriction (IUGR. Several macronutrient interventions had been proposed for adequate protein and energy supplementation during pregnancy. The objective of this paper was to review the effect of balanced protein energy supplementation during pregnancy on birth outcomes. This paper is a part of a series of reviews undertaken for getting estimates of effectiveness of an intervention for input to Lives Saved Tool (LiST model. Methods A literature search was conducted on PubMed, Cochrane Library and WHO regional data bases to identify randomized trials (RCTs and quasi RCTs that evaluated the impact of balanced protein energy supplementation in pregnancy. Balanced protein energy supplementation was defined as nutritional supplementation during pregnancy in which proteins provided less than 25% of the total energy content. Those studies were excluded in which the main intervention was dietary advice to pregnant women for increase in protein energy intake, high protein supplementation (i.e. supplementation in which protein provides at least 25% of total energy content, isocaloric protein supplementation (where protein replaces an equal quantity of non-protein energy content, or low energy diet to pregnant women who are either overweight or who exhibit high weight gain earlier in gestation. The primary outcomes were incidence of small for gestational age (SGA birth, mean birth weight and neonatal mortality. Quality of evidence was evaluated according to the Child Health Epidemiology Reference group (CHERG adaptation of Grading of Recommendations Assessment, Development and Evaluation (GRADE criteria. Results The final number of studies included in our review was eleven comprising of both RCTs and quasi-RCTs. Our meta

  20. Comparative analysis of hourly and dynamic power balancing models for validating future energy scenarios

    DEFF Research Database (Denmark)

    Pillai, Jayakrishnan R.; Heussen, Kai; Østergaard, Poul Alberg

    2011-01-01

    Energy system analyses on the basis of fast and simple tools have proven particularly useful for interdisciplinary planning projects with frequent iterations and re-evaluation of alternative scenarios. As such, the tool “EnergyPLAN” is used for hourly balanced and spatially aggregate annual......, the model is verified on the basis of the existing energy mix on Bornholm as an islanded energy system. Future energy scenarios for the year 2030 are analysed to study a feasible technology mix for a higher share of wind power. Finally, the results of the hourly simulations are compared to dynamic frequency...... simulations incorporating the Vehicle-to-grid technology. The results indicate how the EnergyPLAN model may be improved in terms of intra-hour variability, stability and ancillary services to achieve a better reflection of energy and power capacity requirements....

  1. Energy-balance and melt contributions of supraglacial lakes, Langtang Khola, Nepal

    Science.gov (United States)

    Miles, E. S.; Willis, I. C.; Pellicciotti, F.; Steiner, J. F.; Buri, P.; Arnold, N. S.

    2014-12-01

    As Himalayan debris-covered glaciers retreat and thin in response to climate warming, their long, low-gradient tongues generate substantial meltwater which often collects to form surface lakes. Supraglacial lakes on debris covered glaciers present a mechanism of atmosphere-glacier energy transfer that is poorly-studied, and only conceptually included in mass-balance studies. The ponded water can enhance energy transfer as compared to dry debris cover, while also acting as a reservoir of melt-available energy. Supraglacial lakes occur in association with debris-free ice cliffs, another poorly-constrained but critical component of glacier melt. Understanding the role of supraglacial lakes requires precise monitoring of lake volume, estimation of inlet and outlet flows, and consideration of the energy balance across three surfaces: atmosphere-lake, lake-ice, and lake-saturated debris layer. This research progresses previous modeling work on the energy and mass balance of such supraglacial lakes. Lakes were monitored during the monsoon of 2013 on Lirung Glacier in the Langtang Himal of Nepal with pressure transducers and temperature sensors, while UAV-derived DEMs were used to determine lake geometry. Lake albedo was measured to vary between 0.08 and 0.12, and a nearby on-glacier AWS was used to drive the energy balance. Results indicate that the lakes act as a significant recipient of energy, and suggest that lakes are an important part of an active supraglacial hydrologic system during the monsoon. Melt generated by the lake in contact with bare ice is calculated to be 3-5 cm/day, while energy conducted through saturated lake-bottom debris only resulted in 1-2 mm/day melt. The subaqueous melt rates are of similar magnitude to observed ice-cliff melt rates, allowing lake-cliff systems to persist. Energy leaving the lake system through englacial conduits may be the most important contribution to the glacier's mass balance, driving surface evolution to form new ice

  2. Digital simulation studies on long transmission line protection based on balance of energy

    Institute of Scientific and Technical Information of China (English)

    文明浩; 陈德树; 尹项根

    2001-01-01

    The protection based balance of energy is a new technique specially proposed for long transmission lines. This technique depends upon the calculation of net energy into the transmission line by two independent methods and comparing them to indicate healthy and faulty conditions. In order to study the performance and feasibility of the protection based on balance of energy, the new protection has been extensively tested by using EMTP on a long transmission line with various configurations and operating conditions (including single pole line, double circuit lines and two-phase operation). The results calculated by EMTP show that under any condition of a power system, the proposed technique has excellent performance,the viability even for high resistance ground faults and a short operation time.

  3. The Impact of Anthropogenic Heat on Formation of Urban Heat Island and Energy Consumption Balance

    Directory of Open Access Journals (Sweden)

    P. Shahmohamadi

    2011-01-01

    Full Text Available This paper investigates the impact of anthropogenic heat on formation of urban heat island (UHI and also determines which factors can directly affect energy use in the city. It explores literally the conceptual framework of confliction between anthropogenic heat and urban structure, which produced UHI intensity and affected energy consumption balance. It then discusses how these two factors can be affected and gives implication to the city and then focuses on whether actions should be taken for balancing adaptation and mitigation of UHI effects. It will be concluded by making the three important strategies to minimise the impact of UHI on energy consumption: landscaping, using albedo materials on external surfaces of buildings and urban areas, and promoting natural ventilation.

  4. Generalized energy balance and reciprocity relations for thin-film optics

    Energy Technology Data Exchange (ETDEWEB)

    Dupertuis, M.A.; Proctor, M. [Institut de Micro- et Optoelectronique, Lausanne (Switzerland); Acklin, B. [AT& T Bell Labs., Holmdel, NJ (United States)

    1994-03-01

    Energy balance and reciprocity relations are studied for harmonic inhomogeneous plane waves that are incident upon a stack of continuous absorbing dielectric media that are macroscopically characterized by their electric and magnetic permittivities and their conductivities. New cross terms between parallel electric and parallel magnetic modes are identified in the fully generalized Poynting vector. The symmetry and the relations between the general Fresnel coefficients are investigated in the context of energy balance at the interface. The contributions of the so-called mixed Poynting vector are discussed in detail. In particular a new transfer matrix is introduced for energy fluxes in thin-film optics based on the Poynting and mixed Poynting vectors. Finally, the study of reciprocity relations leads to a generalization of a theorem of reversibility for conducting and dielectric media. 16 refs.

  5. On increasing network lifetime in body area networks using global routing with energy consumption balancing.

    Science.gov (United States)

    Tsouri, Gill R; Prieto, Alvaro; Argade, Nikhil

    2012-09-26

    Global routing protocols in wireless body area networks are considered. Global routing is augmented with a novel link cost function designed to balance energy consumption across the network. The result is a substantial increase in network lifetime at the expense of a marginal increase in energy per bit. Network maintenance requirements are reduced as well, since balancing energy consumption means all batteries need to be serviced at the same time and less frequently. The proposed routing protocol is evaluated using a hardware experimental setup comprising multiple nodes and an access point. The setup is used to assess network architectures, including an on-body access point and an off-body access point with varying number of antennas. Real-time experiments are conducted in indoor environments to assess performance gains. In addition, the setup is used to record channel attenuation data which are then processed in extensive computer simulations providing insight on the effect of protocol parameters on performance. Results demonstrate efficient balancing of energy consumption across all nodes, an average increase of up to 40% in network lifetime corresponding to a modest average increase of 0.4 dB in energy per bit, and a cutoff effect on required transmission power to achieve reliable connectivity.

  6. The energy balance and pressure in the solar transition zone for network and active region features

    Science.gov (United States)

    Nicolas, K. R.; Bartoe, J.-D. F.; Brueckner, G. E.; Vanhoosier, M. E.

    1979-01-01

    The electron pressure and energy balance in the solar transition zone are determined for about 125 network and active region features on the basis of high spectral and spatial resolution extreme ultraviolet spectra. Si III line intensity ratios obtained from the Naval Research Laboratory high-resolution telescope and spectrograph during a rocket flight are used as diagnostics of electron density and pressure for solar features near 3.5 x 10 to the 4th K. Observed ratios are compared with the calculated dependence of the 1301 A/1312 A and 1301 A/1296 A line intensity ratios on electron density, temperature and pressure. Electron densities ranging from 2 x 10 to the 10th/cu cm to 10 to the 12th/cu cm and active region pressures from 3 x 10 to the 15th to 10 to the 16th/cu cm K are obtained. Energy balance calculations reveal the balance of the divergence of the conductive flux and turbulent energy dissipation by radiative energy losses in a plane-parallel homogeneous transition zone (fill factor of 1), and an energy source requirement for a cylindrical zone geometry (fill factor less than 0.04).

  7. Effects of continuous positive airway pressure on energy balance regulation: a systematic review

    Science.gov (United States)

    Shechter, Ari

    2016-01-01

    Obesity is both a cause and a possible consequence of obstructive sleep apnoea (OSA), as OSA seems to affect parameters involved in energy balance regulation, including food intake, hormonal regulation of hunger/satiety, energy metabolism and physical activity. It is known that weight loss improves OSA, yet it remains unclear why continuous positive airway pressure (CPAP) often results in weight gain. The goal of this systematic review is to explore if and how CPAP affects the behaviour and/or metabolism involved in regulating energy balance. CPAP appears to correct for a hormonal profile characterised by abnormally high leptin and ghrelin levels in OSA, by reducing the circulating levels of each. This is expected to reduce excess food intake. However, reliable measures of food intake are lacking, and not yet sufficient to make conclusions. Although studies are limited and inconsistent, CPAP may alter energy metabolism, with reports of reductions in resting metabolic rate or sleeping metabolic rate. CPAP appears to not have an appreciable effect on altering physical activity levels. More work is needed to characterise how CPAP affects energy balance regulation. It is clear that promoting CPAP in conjunction with other weight loss approaches should be used to encourage optimal outcomes in OSA patients. PMID:27824596

  8. Nicotine induces negative energy balance through hypothalamic AMP-activated protein kinase.

    Science.gov (United States)

    Martínez de Morentin, Pablo B; Whittle, Andrew J; Fernø, Johan; Nogueiras, Rubén; Diéguez, Carlos; Vidal-Puig, Antonio; López, Miguel

    2012-04-01

    Smokers around the world commonly report increased body weight after smoking cessation as a major factor that interferes with their attempts to quit. Numerous controlled studies in both humans and rodents have reported that nicotine exerts a marked anorectic action. The effects of nicotine on energy homeostasis have been mostly pinpointed in the central nervous system, but the molecular mechanisms controlling its action are still not fully understood. The aim of this study was to investigate the effect of nicotine on hypothalamic AMP-activated protein kinase (AMPK) and its effect on energy balance. Here we demonstrate that nicotine-induced weight loss is associated with inactivation of hypothalamic AMPK, decreased orexigenic signaling in the hypothalamus, increased energy expenditure as a result of increased locomotor activity, increased thermogenesis in brown adipose tissue (BAT), and alterations in fuel substrate utilization. Conversely, nicotine withdrawal or genetic activation of hypothalamic AMPK in the ventromedial nucleus of the hypothalamus reversed nicotine-induced negative energy balance. Overall these data demonstrate that the effects of nicotine on energy balance involve specific modulation of the hypothalamic AMPK-BAT axis. These targets may be relevant for the development of new therapies for human obesity.

  9. Energy Balance of Irrigated Intercropping Field in the Middle Reaches of Heihe River Basin

    Institute of Scientific and Technical Information of China (English)

    WU Jinkui; DING Yongjian; WANG Genxu; SHEN Yongping; Yusuke YAMAZAKI; Jumpei KUBOTA

    2006-01-01

    Based on the experiments conducted in an irrigated intercropping field in Zhangye Oasis in the middle reaches of Heihe River basin in 2004, the characteristics of radiation budget are analyzed. Furthermore, energy balance is calculated by using Bowen-Ratio Energy Balance (BREB) method. The results show that the ratio of the absorbed radiation to the incoming short radiation in intercropping crop canopy-soil system is increasing with growing stages, from 0.81 in the initial growing stage (IGS) to 0.86 in the late growing stage (LGS). The net radiation, which is smaller in IGS, increases rapidly in the first period of the middle growing stage (MGS) and reaches the maximum value in the second period of MGS. It then somewhat decreases in LGS. The ratio of net radiation to total radiation has a similar trend with the net radiation. In the whole growing stages, latent heat flux, which takes up 70% or so of the net radiation, is the dominant item in energy balance. Sensible heat flux shares 20% of the net radiation and soil heat flux has a percentage of 10%. The characteristics of heat balance vary distinctly in different growing stages. In IGS, the ratios of latent heat flux,sensible heat flux and soil heat flux to net radiation are 44.5%, 23.8% and 31.7% respectively. In MGS, with the increasing of latent heat flux and the decreasing of sensible heat flux and soil heat flux, the ratios turn into 84.4%, 6.3% and 9.3%. In LGS, the soil heat flux maintains 0W/m2 or so, and latent heat flux and sensible heat flux take up 61.4% and 38.6% respectively. The energy balance also shows an obvious daily variation characteristic.

  10. Hunger can be taught: Hunger Recognition regulates eating and improves energy balance

    Directory of Open Access Journals (Sweden)

    Ciampolini M

    2013-06-01

    Full Text Available Mario Ciampolini,1 David Lovell-Smith,2 Timothy Kenealy,3 Riccardo Bianchi4 1Unit of Preventive Gastroenterology, Department of Pediatrics, Università di Firenze, Florence, Italy; 2Department of General Practice, University of Otago, Christchurch, New Zealand; 3Department of General Practice and Primary Health Care, University of Auckland, Auckland, New Zealand; 4Department of Physiology and Pharmacology, State University of New York Downstate Medical Center, Brooklyn, NY, USA Abstract: A set of spontaneous hunger sensations, Initial Hunger (IH, has been associated with low blood glucose concentration (BG. These sensations may arise pre-meal or can be elicited by delaying a meal. With self-measurement of BG, subjects can be trained to formally identify and remember these sensations (Hunger Recognition. Subjects can then be trained to ensure that IH is present pre-meal for most meals and that their pre-meal BG is therefore low consistently (IH Meal Pattern. IH includes the epigastric Empty Hollow Sensation (the most frequent and recognizable as well as less specific sensations such as fatigue or light-headedness which is termed inanition. This report reviews the method for identifying IH and the effect of the IH Meal Pattern on energy balance. In adults, the IH Meal Pattern has been shown to significantly decrease energy intake by one-third, decrease preprandial BG, reduce glycosylated hemoglobin, and reduce insulin resistance and weight in those who are insulin resistant or overweight. Young children as well as adults can be trained in Hunger Recognition, giving them an elegant method for achieving energy balance without the stress of restraint-type dieting. The implications of improving insulin sensitivity through improved energy balance are as wide as improving immune activity. Keywords: energy intake, hunger, energy balance, food intake regulation, prevention, insulin resistance, obesity, diabetes, inflammation, risks

  11. On balancing between minimum energy and minimum delay with radio diversity for wireless sensor networks

    DEFF Research Database (Denmark)

    Moad, Sofiane; Hansen, Morten Tranberg; Jurdak, RajA

    2012-01-01

    to improve the delivery rate but at the cost of increases in energy for wireless sensor networks. In this paper, we propose a scheme for radio diversity that can balance, depending on the traffic nature in the network, between minimizing the energy consumption or minimizing the end-to-end delay. The proposed......The expected number of transmissions (ETX) metric represents the link quality in wireless sensor networks, which is highly variable for a specific radio and it can influence dramatically both of the delay and the energy. To adapt to these fluctuations, radio diversity has been recently introduced...

  12. Genetic correlation between days until start of luteal activity and milk yield, energy balance, and live weights

    NARCIS (Netherlands)

    Veerkamp, R.F.; Oldenbroek, J.K.; Gaast, van der H.J.; Werf, van der J.H.J.

    2000-01-01

    The objective of this study was to estimate genetic correlations among fertility and measures of energy balance, dry matter intake, and live weight (change). Data from 622 first lactation cows (fed ad libitum a complete ration) included milk, fat, and protein yields; energy balance; and live weights

  13. Advances in the two-source energy balance model:Partioning of evaporation and transpiration for row crops

    Science.gov (United States)

    Accurate partitioning of the evaporation (E) and transpiration (T) components of evapotranspiration (ET) in remote sensing models is important for evaluating strategies aimed at increasing crop water productivity. The two-source energy balance (TSEB) model solves the energy balance of the soil-plant...

  14. Advances in the two-source energy balance model: Partioning of evaporation and transpiration for row crops for cotton

    Science.gov (United States)

    Accurate partitioning of the evaporation (E) and transpiration (T) components of evapotranspiration (ET) in remote sensing models is important for evaluating strategies aimed at increasing crop water productivity. The two-source energy balance (TSEB) model solves the energy balance of the soil-plant...

  15. Including the effects of debris cover in a distributed glacier energy balance model (Invited)

    Science.gov (United States)

    Pellicciotti, F.; Reid, T.; Carenzo, M.; Brock, B. W.

    2010-12-01

    Distributed models of glacier energy balance, which make use of digital elevation models and extensive spatial data on local meteorology, have become very useful tools for predicting glacial ablation and runoff in recent years. They generally function by running a one-dimensional energy balance model at every point on a grid on the glacier surface - for each point in the grid the ablation is calculated based on the balance of heat fluxes at the ice-air boundary. However, one key component has been missing from distributed models to date, namely the effects of debris cover. Many glacier ablation zones are mantled in near-continuous blankets of rock debris, and debris-covered glaciers are important drivers of the water cycle in the European Alps, Andes and Himalayas. Moreover, debris covers have been seen to expand in recent years, so it is essential to assess exactly how the presence of debris may affect a glacier’s surface energy balance and potential responses to climate changes. The effects of a debris cover are complicated by the varying surface roughness, albedo and thermal properties of the debris in question, but generally a debris cover reduces glacier melt rate by insulating the glacier surface from direct solar radiation. Even on glaciers where the debris cover is not continuous, isolated patches of debris caused by rockfalls can affect the glacier evolution by introducing differential ablation across the glacier surface, thus creating ice-cored moraines that may persist after ‘clean’ parts of the glacier have wasted away. This paper presents the results of incorporating a one-dimensional ‘debris energy balance model’ called DEB-Model (Reid and Brock 2010) into a distributed melt model for Haut Glacier d’Arolla, Switzerland. DEB-Model numerically estimates debris surface temperature by considering the balance of heat fluxes at the air-debris interface, then calculates heat conduction through the debris in order to estimate melt rates at the

  16. On-farm estimation of energy balance in dairy cows using only frequent body weight measurements and body condition score

    OpenAIRE

    Edwards, David; Friggens, Nicolas Charles

    2012-01-01

    Precise energy balance estimates for individual cows are of great importance to monitor health, reproduction, and feed management. Energy balance is usually calculated as energy input minus output (EBinout), requiring measurements of feed intake and energy output sources (milk, maintenance, activity, growth, and pregnancy). Except for milk yield, direct measurements of the other sources are difficult to obtain in practice, and estimates contain considerable error sources, limiting on-farm use...

  17. Co-operative Scheduled Energy Aware Load-Balancing technique for an Efficient Computational Cloud

    Directory of Open Access Journals (Sweden)

    T R V Anandharajan

    2011-03-01

    Full Text Available Cloud Computing in the recent years has been taking its evolution from the scientific to the non scientific and commercial applications. Power consumption and Load balancing are very important and complex problem in computational Cloud. A computational Cloud differs from traditional high-performance computing systems in the heterogeneity of the computing nodes, as well as the communication links that connect the different nodes together. Load Balancing is a very important component in the commodity services based cloud computing. There is a need to develop algorithms that can capture this complexity yet can be easily implemented and used to solve a wide range of load-balancing scenarios in a Data and Computing intensive applications. In this paper, we propose to find the best EFFICIENT cloud resource by Co-operative Power aware Scheduled Load Balancing solution to the Cloud load-balancing problem. The algorithm developed combines the inherent efficiency of the centralized approach, energy efficient and the fault-tolerant nature of the distributed environment like Cloud.

  18. Long-term mass- and energy balance of Kongsvegen glacier, Spitzbergen

    Science.gov (United States)

    Krismer, Thomas; Obleitner, Friedrich; Kohler, Jack

    2010-05-01

    We present meteorological and glaciological data from the equilibrium line (ELA) of Kongsvegen glacier (550masl) in Svalbard, covering the period 2000 until 2008. Mean annual air temperatures for the period range from -6.9 to -10.1°C and specific net annual mass balances range from -670 to +281 mm w eq. During some years substantial superimposed ice was formed and even survived the summer. The meteorological data were homogenized and used for input and validation of mass- and energy-balance simulations. The meteorological regime at the ELA is characterized by a coreless winter and summer temperatures around 0°C. Wind conditions are largely determined by katabatic winds and topgraphically channeled upper-air winds. Net short-wave radiation is determined by cloudiness during the polar day and by the seasonal evolution of glacier surface albedo. Long-wave radiation fluxes withdraw energy throughout the year and the mean annual net radiation is almost negligible. The turbulent sensible heat fluxes constitute a comparatively strong and continuous source of energy. The latent heat flux is characterized by prevailing condensation during winter and evaporation during summer. On average, however, the turbulent fluxes provide only a small amount of heat to the glacier. Most of the energy available from the atmosphere is used for summer melt and a small amount goes into heating the near surface ice layers. Similar investigations were performed at the tongue of the glacier (170masl) for a shorter period. Here the conditions are characterized by enhanced input from the atmospheric fluxes and correspondingly increased melt rates. In addition, accumulation is usually small (>50 cm snow) and melt can also occur during winter. We then investigate whether spatially distributed mass balance can be simulated using data measured outside of the glacier. Regression models were developed to derive model input from climate data measured at a nearby research station. These models are

  19. Surface energy balance and resolution effects using ASTER imagery over Jornada, New Mexico

    Science.gov (United States)

    French, A.; Schmugge, T.; Kustas, W.; Prueger, J.; Jacob, F.

    2003-04-01

    Knowledge of the relationship between the accuracy of surface energy balance estimates and remote sensing resolution is important for the integration of instantaneous satellite observations with regional and global scale hydrological models. Higher resolution thermal infrared imagery, such as from the ASTER sensor (90 m), provide the needed observations to distinguish between hydrological end-member conditions and are expected to be more accurate than imagery with resolutions >1 km. But higher resolution observations are instantaneous and usually not repeatable at time intervals less than 2 to 4 weeks. On the other hand, lower resolution imagery from sensors such as GOES, in combination with hydrological assimilation models, can estimate the diurnal variations in surface energy balance. To assess the relative merits of resolution vs. imaging frequency, we have collected a series of ASTER observations, between May and October 2002 over the Jornada Experimental Range in New Mexico, and modeled the surface energy balance. Estimates of the energy components are made from the original resolution (90 m) up to an aggregated resolution of 4 km. These estimates are compared with ground based flux observations, and then compared with each other. Loss in range of data and expected biases due to resolution effects will be discussed.

  20. Effects of fatty acid supplements on milk yield and energy balance of lactating dairy cows.

    Science.gov (United States)

    Harvatine, K J; Allen, M S

    2006-03-01

    Saturated and unsaturated fatty acid supplements (FS) were evaluated for effects on yield of milk and milk components, concentration of milk components including milk fatty acid profile, and energy balance. Eight ruminally and duodenally cannulated cows and 8 noncannulated cows were used in a replicated 4 x 4 Latin square design experiment with 21-d periods. Treatments were control and a linear substitution of 2.5% fatty acids from saturated FS (SAT; prilled, hydrogenated free fatty acids) for partially unsaturated FS (UNS; calcium soaps of long-chain fatty acids). The SAT treatment did not change milk fat concentration, but UNS linearly decreased milk fat in cannulated cows and tended to decrease milk fat in noncannulated cows compared with control. Milk fat depression with UNS corresponded to increased concentrations of trans-10, cis-12 conjugated linoleic acid and trans C18:1 fatty acids in milk. Milk fat profile was similar for SAT and control, but UNS decreased concentration of short- and medium-chain FA. Digestible energy intake tended to decrease linearly with increasing unsaturated FS in cannulated and noncannulated cows. Increasing unsaturated FS linearly increased empty body weight and net energy gain in cannulated cows, whereas increasing saturated FS linearly increased plasma insulin. Efficiency of conversion of digestible energy to milk tended to decrease linearly with increasing unsaturated FS for cannulated cows only. Addition of SAT provided little benefit to production and energy balance, whereas UNS decreased energy intake and milk energy yield.

  1. Strategies for Achieving Healthy Energy Balance Among African Americans in the Mississippi Delta

    Directory of Open Access Journals (Sweden)

    Groesbeck P. Parham, MD

    2007-10-01

    Full Text Available IntroductionLow-income African Americans who live in rural areas of the Deep South are particularly vulnerable to diseases associated with unhealthy energy imbalance. The Centers for Disease Control and Prevention (CDC has suggested various physical activity strategies to achieve healthy energy balance. Our objective was to conduct formal, open-ended discussions with low-income African Americans in the Mississippi Delta to determine 1 their dietary habits and physical activity levels, 2 their attitudes toward CDC’s suggested physical activity strategies, and 3 their suggestions on how to achieve CDC’s strategies within their own environment. MethodsA qualitative method (focus groups was used to conduct the study during 2005. Prestudy meetings were held with African American lay health workers to formulate a focus group topic guide, establish inclusion criteria for focus group participants, select meeting sites and times, and determine group segmentation guidelines. Focus groups were divided into two phases.ResultsAll discussions and focus group meetings were held in community centers within African American neighborhoods in the Mississippi Delta and were led by trained African American moderators. Phase I focus groups identified the following themes: overeating, low self-esteem, low income, lack of physical exercise, unhealthy methods of food preparation, a poor working definition of healthy energy balance, and superficial knowledge of strategies for achieving healthy energy balance. Phase 2 focus groups identified a preference for social support-based strategies for increasing physical activity levels. ConclusionEnergy balance strategies targeting low-income, rural African Americans in the Deep South may be more effective if they emphasize social interaction at the community and family levels and incorporate the concept of community volunteerism.

  2. Surface energy balance of subarctic lowland palsa mires related to permafrost degradation

    Science.gov (United States)

    Stiegler, C.; Lindroth, A.; Johansson, M.

    2013-12-01

    During the last decades, an accelerating trend in increasing active-layer thickness and rising permafrost temperatures has been observed in the Nordic area. One region, where permafrost is particularly vulnerable to any further climate change is the Torneträsk area in northern subarctic Sweden. Within the next decades a projected ongoing climate warming and increase in snow cover will most likely lead to the disappearance of lowland permafrost in this region, affecting surface vegetation cover, greenhouse gas emissions and surface energy balance. In this study we link first results of surface energy balance measurements from lowland palsa mires in the Torneträsk region to the current state of permafrost and the degradation of peat plateaus. The study area covers several mires with similar local topographic conditions along an east-west oriented transect. Due to a strong climatic gradient, with maritime climate in the west and a more continental climate in the east, active layer thickness and permafrost temperatures generally increase from east to west while permafrost thickness decreases. In the recent years permafrost has fully disappeared at our westernmost study site while at the other investigated locations the peat plateaus show varying stages of degradation. For our measurements of energy balance components we use both a mobile energy balance tower and a stationary eddy covariance tower. Data has been collected during the growing season in 2013 by measuring all components of the surface energy budget, i.e. net radiation, turbulent fluxes of sensible and latent heat as well as ground heat fluxes. In addition, we measure active layer thickness and both soil moisture and soil temperature at various depths. First results display that the turbulent fluxes of latent heat exceed the fluxes of sensible heat at all investigated sites. The difference is more pronounced at those mires where permafrost degradation is at an advanced stage and therefore more open water

  3. New insights on the role of the endocannabinoid system in the regulation of energy balance.

    Science.gov (United States)

    Gatta-Cherifi, B; Cota, D

    2016-02-01

    Within the past 15 years, the endocannabinoid system (ECS) has emerged as a lipid signaling system critically involved in the regulation of energy balance, as it exerts a regulatory control on every aspect related to the search, the intake, the metabolism and the storage of calories. An overactive endocannabinoid cannabinoid type 1 (CB1) receptor signaling promotes the development of obesity, insulin resistance and dyslipidemia, representing a valuable pharmacotherapeutic target for obesity and metabolic disorders. However, because of the psychiatric side effects, the first generation of brain-penetrant CB1 receptor blockers developed as antiobesity treatment were removed from the European market in late 2008. Since then, recent studies have identified new mechanisms of action of the ECS in energy balance and metabolism, as well as novel ways of targeting the system that may be efficacious for the treatment of obesity and metabolic disorders. These aspects will be especially highlighted in this review.

  4. Botswana water and surface energy balance research program. Part 2: Large scale moisture and passive microwaves

    Science.gov (United States)

    Vandegriend, A. A.; Owe, M.; Chang, A. T. C.

    1992-01-01

    The Botswana water and surface energy balance research program was developed to study and evaluate the integrated use of multispectral satellite remote sensing for monitoring the hydrological status of the Earth's surface. The research program consisted of two major, mutually related components: a surface energy balance modeling component, built around an extensive field campaign; and a passive microwave research component which consisted of a retrospective study of large scale moisture conditions and Nimbus scanning multichannel microwave radiometer microwave signatures. The integrated approach of both components are explained in general and activities performed within the passive microwave research component are summarized. The microwave theory is discussed taking into account: soil dielectric constant, emissivity, soil roughness effects, vegetation effects, optical depth, single scattering albedo, and wavelength effects. The study site is described. The soil moisture data and its processing are considered. The relation between observed large scale soil moisture and normalized brightness temperatures is discussed. Vegetation characteristics and inverse modeling of soil emissivity is considered.

  5. Minimizing Wind Power Producer's Balancing Costs Using Electrochemical Energy Storage: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Miettinen, J.; Tikka, V.; Lassila, J.; Partanen, J.; Hodge, B. M.

    2014-08-01

    This paper examines how electrochemical energy storage can be used to decrease the balancing costs of a wind power producer in the Nordic market. Because electrochemical energy storage is developing in both technological and financial terms, a sensitivity analysis was carried out for the most important variables in the wind-storage hybrid system. The system was studied from a wind power producer's point of view. The main result is that there are no technical limitations to using storage for reducing the balancing costs. However, in terms of economic feasibility, installing hybrid wind-storage systems such as the one studied in this paper faces challenges in both the short and long terms.

  6. Climatological evaluation of some fluxes of the surface energy and soil water balances over France

    Directory of Open Access Journals (Sweden)

    E. M. Choisnel

    Full Text Available This paper presents some statistical evaluations of the surface energy and soil water balance fluxes, for a prairie-type canopy, using the Earth model with a double-reservoir system for the management of the soil water reserve and the regulation of actual evapotranspiration. The mean values of these fluxes are estimated from energy and water balance simulations done on a 30-year climatic reference period (1951–1980. From values of these fluxes calculated for each meteorological synoptic station, mappings of net radiation, actual evapotranspiration, drainage and conduction fluxes have been made over French territory. Lastly, a few conclusions pertaining to the spatial variability of fluxes and to the partition of rainfall between run-off and drainage on the one hand and replenishment of the soil water reserve on the other hand are drawn from these preliminary results.

  7. Aerosol influence on energy balance of the middle atmosphere of Jupiter.

    Science.gov (United States)

    Zhang, Xi; West, Robert A; Irwin, Patrick G J; Nixon, Conor A; Yung, Yuk L

    2015-12-22

    Aerosols are ubiquitous in planetary atmospheres in the Solar System. However, radiative forcing on Jupiter has traditionally been attributed to solar heating and infrared cooling of gaseous constituents only, while the significance of aerosol radiative effects has been a long-standing controversy. Here we show, based on observations from the NASA spacecraft Voyager and Cassini, that gases alone cannot maintain the global energy balance in the middle atmosphere of Jupiter. Instead, a thick aerosol layer consisting of fluffy, fractal aggregate particles produced by photochemistry and auroral chemistry dominates the stratospheric radiative heating at middle and high latitudes, exceeding the local gas heating rate by a factor of 5-10. On a global average, aerosol heating is comparable to the gas contribution and aerosol cooling is more important than previously thought. We argue that fractal aggregate particles may also have a significant role in controlling the atmospheric radiative energy balance on other planets, as on Jupiter.

  8. An energy balance perspective on regional CO2-induced temperature changes in CMIP5 models

    Science.gov (United States)

    Räisänen, Jouni

    2016-08-01

    An energy balance decomposition of temperature changes is conducted for idealized transient CO2-only simulations in the fifth phase of the Coupled Model Intercomparison Project. The multimodel global mean warming is dominated by enhanced clear-sky greenhouse effect due to increased CO2 and water vapour, but other components of the energy balance substantially modify the geographical and seasonal patterns of the change. Changes in the net surface energy flux are important over the oceans, being especially crucial for the muted warming over the northern North Atlantic and for the seasonal cycle of warming over the Arctic Ocean. Changes in atmospheric energy flux convergence tend to smooth the gradients of temperature change and reduce its land-sea contrast, but they also amplify the seasonal cycle of warming in northern North America and Eurasia. The three most important terms for intermodel differences in warming are the changes in the clear-sky greenhouse effect, clouds, and the net surface energy flux, making the largest contribution to the standard deviation of annual mean temperature change in 34, 29 and 20 % of the world, respectively. Changes in atmospheric energy flux convergence mostly damp intermodel variations of temperature change especially over the oceans. However, the opposite is true for example in Greenland and Antarctica, where the warming appears to be substantially controlled by heat transport from the surrounding sea areas.

  9. Characterization of adult ghrelin and ghrelin receptor knockout mice under positive and negative energy balance.

    Science.gov (United States)

    Sun, Yuxiang; Butte, Nancy F; Garcia, Jose M; Smith, Roy G

    2008-02-01

    Ghrelin and the ghrelin receptor (GH secretagogue receptor, GHS-R), are believed to have important roles in energy homeostasis. We describe results from the first studies to be conducted in congenic (N10) adult ghrelin(-/-) and Ghsr(-/-) mice under conditions of both positive (high-fat diet) and negative (caloric restriction) energy balance. In contrast to results from young N2 mutant mice, changes in body weight and energy expenditure are not clearly distinguishable across genotypes. Although respiratory quotient was lower in mice fed a high-fat diet, no differences were evident between littermate wild-type and null genotypes. With normal chow, a modest decrease trend in respiratory quotient was detected in ghrelin(-/-) mice but not in Ghsr(-/-) mice. Under caloric restriction, the weight loss of ghrelin(-/-) and Ghsr(-/-) mice was identical to wild-type littermates, but blood glucose levels were significantly lower. We conclude that adult congenic ghrelin(-/-) and Ghsr(-/-) mice are not resistant to diet-induced obesity but under conditions of negative energy balance show impairment in maintaining glucose homeostasis. These results support our hypothesis that the primary metabolic function of ghrelin in adult mice is to modulate glucose sensing and insulin sensitivity, rather than directly regulate energy intake and energy expenditure.

  10. Measurement of Turbulence Energy Balance in a Two-Dimensional Wall Jet along a Plane Surface

    OpenAIRE

    藤沢, 延行; 白井, 紘行

    1987-01-01

    The sructure of turbulence in a wall jet along a plane surface is investigated by measuring the balance of turbulence energy. With the aid of a hot-wire anemometer system, convection velocities of small-scale turbulent motion are measured as well as other time-averaged flow properties and turbulence characteristics. It is found that the convection velocity of small-scale turbulence deviates significantly from the mean flow velocity, that is, Taylor's hypothesis is not valid for the present wa...

  11. Multi-scale Modeling of Energy Balance Fluxes in a Dense Tamarisk Riparian Forest

    Science.gov (United States)

    Neale, C. M.; Santos, C. A.; Watts, D.; Osterberg, J.; Hipps, L. E.; Sritharan, S. I.

    2008-12-01

    Remote sensing of energy balance fluxes has become operationally more viable over the last 10 years with the development of more robust multi-layer models and the availability of quasi-real time satellite imagery from most sensors. Riparian corridors in semi-arid and arid areas present a challenge to satellite based techniques for estimating evapotranspiration due to issues of scale and pixel resolution, especially when using the thermal infrared bands. This paper will present energy balance measurement and modeling results over a Salt Cedar (Tamarix Ramosissima) forest in the Cibola National Wildlife Refuge along the Colorado River south of Blythe, CA. The research site encompasses a 600 hectare area populated by mostly Tamarisk stands of varying density. Three Bowen ratio systems are installed on tall towers within varying densities of forest cover in the upwind footprint and growing under varying depths to the water table. An additional eddy covariance tower is installed alongside a Bowen ratio system on one of the towers. Flux data has been gathered continuously since early 2007. In the summer of 2007, a Scintec large aperture scintillometer was installed between two of the towers over 1 km apart and has been working continuously along with the flux towers. Two intensive field campaigns were organized in June 2007 and May 2008 to coincide with LANDSAT TM5, MODIS and ASTER overpasses. High resolution multispectral and thermal imagery was acquired at the same time with the USU airborne system to provide information for the up- scaling of the energy balance fluxes from tower to satellite scales. The paper will present comparisons between the different energy balance measuring techniques under the highly advective conditions of the experimental site, concentrating on the scintillometer data. Preliminary results of remotely sensed modeling of the fluxes at different scales and model complexity will also be presented.

  12. Anthropogenic climate change in an integrated energy balance model of global and urban warming

    OpenAIRE

    Sato, Kimitoshi

    2014-01-01

    This paper presents an integrated energy balance model of global and urban warming in the attributes/functionings framework à la Gorman-Lancaster-Sen and proposes a Global Warming Function and an Urban Warming Function. Also presented is a concept of Heat Island Integral, which measures the difference of anthropogenic heat stocks between two regions. The model involves residents, producers such as offices and manufacturers, and landscape gardeners who play a very important role in cooling dow...

  13. Energy-balanced multiple-sensor collaborative scheduling for maneuvering target tracking in wireless sensor networks

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    An energy-balanced multiple-sensor collaborative scheduling is proposed for maneuvering target tracking in wireless sensor networks (WSNs). According to the position of the maneuvering target, some sensor nodes in WSNs are awakened to form a sensor cluster for target tracking collaboratively. In the cluster, the cluster head node is selected to implement tracking task with changed sampling interval. The distributed interactive multiple model (IMM) filter is employed to estimate the target state. The estimat...

  14. Voltage Scheduling Droop Control for State-of-Charge Balance of Distributed Energy Storage in DC Microgrids

    DEFF Research Database (Denmark)

    Li, Chendan; Dragicevic, Tomislav; Aldana, Nelson Leonardo Diaz;

    2014-01-01

    the State-of-Charge balance. In this paper, a new droop method based on voltage scheduling for State-of-Charge balance is proposed to keep the SoC balance for the energy storage units. The proposed method has the advantage of avoiding the stability problem existed in traditional methods based on droop gain...... scheduling. Simulation experiment is taken in Matlab on a DC microgrid with two distributed energy storage units. The simulation results show that the proposed method has successfully achieved SoC balance during the load changes while maintaining the DC bus voltage within the allowable range....

  15. Using a biocultural approach to examine migration/globalization, diet quality, and energy balance.

    Science.gov (United States)

    Himmelgreen, David A; Cantor, Allison; Arias, Sara; Romero Daza, Nancy

    2014-07-01

    The aim of this paper is to examine the role and impact that globalization and migration (e.g., intra-/intercontinental, urban/rural, and circular) have had on diet patterns, diet quality, and energy balance as reported on in the literature during the last 20 years. Published literature from the fields of anthropology, public health, nutrition, and other disciplines (e.g., economics) was collected and reviewed. In addition, case studies from the authors' own research are presented in order to elaborate on key points and dietary trends identified in the literature. While this review is not intended to be comprehensive, the findings suggest that the effects of migration and globalization on diet quality and energy balance are neither lineal nor direct, and that the role of social and physical environments, culture, social organization, and technology must be taken into account to better understand this relationship. Moreover, concepts such as acculturation and the nutrition transition do not necessarily explain or adequately describe all of the global processes that shape diet quality and energy balance. Theories from nutritional anthropology and critical bio-cultural medical anthropology are used to tease out some of these complex interrelationships.

  16. The footprint of Asian monsoon dynamics in the mass and energy balance of a Tibetan glacier

    Science.gov (United States)

    Mölg, T.; Maussion, F.; Yang, W.; Scherer, D.

    2012-12-01

    Determinations of glacier-wide mass and energy balance are still scarce for the remote mountains of the Tibetan Plateau, where field measurements are challenging. Here we run and evaluate a physical, distributed mass balance model for Zhadang Glacier (central Tibet, 30° N) based on in-situ measurements over 2009-2011 and an uncertainty estimate by Monte Carlo and ensemble strategies. The model application aims to provide the first quantification of how the Indian Summer Monsoon (ISM) impacts an entire glacier over the various stages of the monsoon's annual cycle. We find a strong and systematic ISM footprint on the interannual scale. Early (late) monsoon onset causes higher (lower) accumulation, and reduces (increases) the available energy for ablation primarily through changes in absorbed shortwave radiation. By contrast, only a weak footprint exists in the ISM cessation phase. Most striking though is the core monsoon season: local mass and energy balance variability is fully decoupled from the active/break cycle that defines large-scale atmospheric variability during the ISM. Our results demonstrate quantitatively that monsoon onset strongly affects the ablation season of glaciers in Tibet. However, we find no direct ISM impact on the glacier in the main monsoon season, which has not been acknowledged so far. This result also adds cryospheric evidence that, once the monsoon is in full swing, regional atmospheric variability prevails on the Tibetan Plateau in summer.

  17. Determining water use of sorghum from two-source energy balance and radiometric temperatures

    Directory of Open Access Journals (Sweden)

    J. M. Sánchez

    2011-10-01

    Full Text Available Estimates of surface actual evapotranspiration (ET can assist in predicting crop water requirements. An alternative to the traditional crop-coefficient methods are the energy balance models. The objective of this research was to show how surface temperature observations can be used, together with a two-source energy balance model, to determine crop water use throughout the different phenological stages of a crop grown. Radiometric temperatures were collected in a sorghum (Sorghum bicolor field as part of an experimental campaign carried out in Barrax, Spain, during the 2010 summer growing season. Performance of the Simplified Two-Source Energy Balance (STSEB model was evaluated by comparison of estimated ET with values measured on a weighing lysimeter. Errors of ±0.14 mm h−1 and ±1.0 mm d−1 were obtained at hourly and daily scales, respectively. Total accumulated crop water use during the campaign was underestimated by 5%. It is then shown that thermal radiometry can provide precise crop water necessities and is a promising tool for irrigation management.

  18. The footprint of Asian monsoon dynamics in the mass and energy balance of a Tibetan glacier

    Directory of Open Access Journals (Sweden)

    T. Mölg

    2012-08-01

    Full Text Available Determinations of glacier-wide mass and energy balance are still scarce for the remote mountains of the Tibetan Plateau, where field measurements are challenging. Here we run and evaluate a physical, distributed mass balance model for Zhadang glacier (central Tibet, 30° N, based on in-situ measurements over 2009–2011 and an uncertainty estimate by Monte Carlo and ensemble strategies. The model application aims to provide the first quantification of how the Indian Summer Monsoon (ISM impacts an entire glacier over the various stages of the monsoon's annual cycle. We find a strong and systematic ISM footprint on the interannual scale. Early (late monsoon onset causes higher (lower accumulation, and reduces (increases the available energy for ablation primarily through changes in absorbed shortwave radiation. By contrast, only a weak footprint exists in the ISM cessation phase. Most striking though is the core monsoon season: local mass and energy balance variability is fully decoupled from the active/break cycle that defines large-scale atmospheric variability during the ISM. Our results demonstrate quantitatively that monsoon onset strongly affects the ablation season of glaciers in Tibet. However, we find no direct ISM impact on the glacier in the main monsoon season, which has not been acknowledged so far. This result also adds cryospheric evidence that regional modification of the large-scale monsoon flow prevails on the Tibetan Plateau in summer.

  19. The footprint of Asian monsoon dynamics in the mass and energy balance of a Tibetan glacier

    Directory of Open Access Journals (Sweden)

    T. Mölg

    2012-12-01

    Full Text Available Determinations of glacier-wide mass and energy balance are still scarce for the remote mountains of the Tibetan Plateau, where field measurements are challenging. Here we run and evaluate a physical, distributed mass balance model for Zhadang Glacier (central Tibet, 30° N based on in-situ measurements over 2009–2011 and an uncertainty estimate by Monte Carlo and ensemble strategies. The model application aims to provide the first quantification of how the Indian Summer Monsoon (ISM impacts an entire glacier over the various stages of the monsoon's annual cycle. We find a strong and systematic ISM footprint on the interannual scale. Early (late monsoon onset causes higher (lower accumulation, and reduces (increases the available energy for ablation primarily through changes in absorbed shortwave radiation. By contrast, only a weak footprint exists in the ISM cessation phase. Most striking though is the core monsoon season: local mass and energy balance variability is fully decoupled from the active/break cycle that defines large-scale atmospheric variability during the ISM. Our results demonstrate quantitatively that monsoon onset strongly affects the ablation season of glaciers in Tibet. However, we find no direct ISM impact on the glacier in the main monsoon season, which has not been acknowledged so far. This result also adds cryospheric evidence that, once the monsoon is in full swing, regional atmospheric variability prevails on the Tibetan Plateau in summer.

  20. Resting energy expenditure and nitrogen balance in critically ill pediatric patients on mechanical ventilation.

    Science.gov (United States)

    Coss-Bu, J A; Jefferson, L S; Walding, D; David, Y; Smith, E O; Klish, W J

    1998-09-01

    Nutritional support is important in critically ill patients, with variable energy and nitrogen requirements (e.g., sepsis, trauma, postsurgical state) in this population. This study investigates how age, severity of illness, and mechanical ventilation are related to resting energy expenditure (REE) and nitrogen balance. Nineteen critically ill children (mean age, 8 +/- 6 [SD] y and range 0.4-17.0 y) receiving total parenteral nutrition (TPN) were enrolled. We used indirect calorimetry to measure REE. Expected energy requirements (EER) were obtained from Talbot tables. Pediatric Risk of Mortality (PRISM) and Therapeutic Intervention Scoring System (TISS) score were calculated. Total urinary nitrogen was measured using the Kjeldahl method. PRISM and TISS scores were 9 +/- 5 and 31 +/- 6 points, respectively. REE was 62 +/- 25 kcal.kg-1.d-1, EER was 42 +/- 11 kcal.kg-1. d-1, and caloric intake was 49 +/- 22 kcal.kg-1.d-1. Nitrogen intake was 279 +/- 125 mg.kg-1.d-1, total urinary nitrogen was 324 +/- 133 mg.kg-1.d-1, and nitrogen balance was -120 +/- 153 mg.kg-1.d-1. The protein requirement in this population was approximately 2.8 g.kg-1.d-1. These critically ill children were hypermetabolic, with REE 48% higher (20 kcal.kg-1.d-1) than expected. Nitrogen balance significantly correlated with caloric and protein intake, urinary nitrogen, and age, but not with severity of illness scores or ventilatory parameters.

  1. Energy city Frederikshavn. 100% balanced renewable energy supply. [Denmark]; Energibyen Frederikshavn. ''100% VE-forsyning uden ubalancer''. Slutrapportering

    Energy Technology Data Exchange (ETDEWEB)

    Dehghan, B.

    2010-11-15

    For the Energy City, the target is to become a 100 % renewable energy city in 2015, also with regard to the power balance. A tool has been developed which can calculate various power parameters so that a balanced system with 100 % energy supply can be optimized without preventing surrounding towns and municipalities from establishing renewable energy supply, too. The scenarios have been delivered by Aalborg University and are outputs from the Energy City model. It is the total realization of the mentioned energy scenarios that makes it possible that the Energy City can reach its actual target of 100 % conversion to renewable energy. (LN)

  2. Brazilian energy balance 2011 - year 2010. Final report; Balanco energetico nacional 2011 - ano base 2010. Relatorio final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The Brazilian energy balance - BEB - is divided into eight chapters and ten annexes, whose contents are as follow: chapter 1 - Energy Analysis and Aggregated Data - presents energy highlights per source in 2010 and analyses the evolution of the internal offer of energy and its relationship with economic growth in 2010; chapter 2 - Energy Supply and Demand by Source - has the accountancy, per primary and secondary energy sources, of the production, import, export, variation of stocks, losses, adjustments, desegregated total per socioeconomic sector in the country; chapter 3 - Energy Consumption by Sector - presents the final energy consumption classified by primary and secondary source for each sector of the economy; chapter 4 - Energy Imports and Exports - presents the evolution of the data on the import and export of energy and the dependence on external energy; chapter 5 - Balance of Transformation Centers - presents the energy balances for the energy transformation centers including their losses; chapter 6 - Energy Resources and Reserves - has the basic concepts use in the survey of resources and reserves of primary energy sources, with the evolution of the data from 1974 to 2010, through graphs and tables; chapter 7 - Energy and Socioeconomics - contains a comparison of energy, economic and population parameters, specific consumption, energy intensities, average prices and spending on petroleum imports; chapter 8 - State Energy Data - presents energy data for the states by Federal Unit, main energy source production, energy installations, reserves and hydraulic potential. (author)

  3. On-farm estimation of energy balance in dairy cows using only frequent body weight measurements and body condition score

    DEFF Research Database (Denmark)

    Thorup, Vivi Mørkøre; Edwards, David; Friggens, N C

    2012-01-01

    Precise energy balance estimates for individual cows are of great importance to health, reproduction and feed management. Energy balance is usually calculated as energy input minus output (EBalinout), requiring measurements of feed intake and energy output sources (milk, maintenance, activity......, growth and pregnancy). Except milk yield, direct measurements of these are difficult to obtain in practice, and estimates involve considerable error sources, so limiting on-farm use. Alternatively, energy balance can be estimated from body reserve changes (EBalbody) using body weight (BW) and body...... repeated BW, a milk-free BW was derived, and from between milking repeated BW, a meal-related gutfill-free BW was derived. Changes in BW and BCS were used to calculate changes in body protein, body lipid, and thus EBalbody during the first 150 DIM. As there is no gold standard energy balance measurement...

  4. Energy Balance of a Bose Gas in Curved Space-times

    CERN Document Server

    Matos, Tonatiuh; Bernal, Tula

    2016-01-01

    In the present work, we obtain a general energy balance equation for a boson gas in curved space-times that can be interpreted as the generalization of the corresponding first law of thermodynamics for the system. By using a 3+1 foliation of the space-time and performing a Madelung transformation, we rewrite the Klein-Gordon-Maxwell equations in a general curved space-time into its hydrodynamic version, where we can identify the different energy contributions of the system and separate them into the gravitational, quantum, electromagnetic and kinetic ones.

  5. Added glasshouses - a positive or a negative energy balance?; Anbau von Wintergaerten - Energiebilanz positiv oder negativ?

    Energy Technology Data Exchange (ETDEWEB)

    Marquardt, H. [Inst. fuer Weiterbildung und Baupruefung (IWB) an der Hochschule 21, Buxtehude (Germany)

    2008-07-01

    Added Glasshouses - a positive or a negative Energy Balance? Calculations show that heated glasshouses with double-pane, argon-filled, low-e glazing and orientation towards the south, compared with not heated glasshouses - need high heat loads [W] during cold winter nights resulting in large heating units, - but, on the other hand the energy consumption of the whole building - applied to the larger interior space by the added glasshouse [kWh/(m{sup 2} x a)] - will go down during the heating period. (orig.)

  6. Energy balance in olive oil farms: comparison of organic and conventional farming systems.

    Science.gov (United States)

    Moreno, Marta M.; Meco, Ramón; Moreno, Carmen

    2013-04-01

    The viability of an agricultural production system not only depends on the crop yields, but especially on the efficient use of available resources. However, the current agricultural systems depend heavily on non-renewable energy consumption in the form of fertilizers, fossil fuels, pesticides and machinery. In developed countries, the economic profitability of different productive systems is dependent on the granting of subsidies of diverse origin that affect both production factors (or inputs) and the final product (or output). Leaving such external aids, energy balance analysis reveals the real and most efficient form of management for each agroclimatic region, and is also directly related to the economic activity and the environmental state. In this work we compare the energy balance resulting from organic and conventional olive oil farms under the semi-arid conditions of Central Spain. The results indicate that the mean energy supplied to the organic farms was sensitively lower (about 30%) in comparison with the conventional management, and these differences were more pronounced for the biggest farms (> 15 ha). Mean energy outputs were about 20% lower in the organic system, although organic small farms (< 15 ha) resulted more productive than the conventional small ones. However, these lower outputs were compensated by the major market value obtained from the organic products. Chemical fertilizers and pesticides reached about 60% of the total energy inputs in conventional farming; in the organic farms, however, this ratio scarcely reached 25%. Human labor item only represented a very small amount of the total energy input in both cases (less than 1%). As conclusions, both management systems were efficient from an energy point of view. The value of the organic production should be focused on the environmental benefits it provides, which are not usually considered in the conventional management on not valuing the damage it produces to the environment. Organic

  7. Consequences of inadequate food energy and negative energy balance in humans.

    Science.gov (United States)

    Kurpad, A V; Muthayya, S; Vaz, M

    2005-10-01

    Energy deficiency is probably best measured in adults by the body mass index (BMI). Acute energy deficiency (AED) is associated with body weight loss, along with changes in body composition, as well as a reduced BMR and physical activity. Chronic energy deficiency (CED) is an inadequacy in food to which individuals adapt, at some cost. Individuals with this have never 'lost' weight: they have simply grown less. They adapt to the decreased food energy by reductions in their total energy expenditure (TEE), linked mainly to a lower body size, and to their physical activity. It seems unlikely that enhanced metabolic efficiency contributes substantially to energy saving in CED. Supplementation of energy deficient individuals is accompanied by significant fat deposition; this may have deleterious consequences. Women in many developing countries achieve a successful outcome to pregnancy in spite of being chronically undernourished. Reductions in basal metabolism and behavioural changes in the form of diminished physical activity could meet most of the extra energy needed for pregnancy. Milk energy output is maintained within the expected range in undernourished lactating mothers. Energy deficiency in children is best measured by height-for-age for stunting, and weight-for-height for wasting. Deficits in behavioural and functional parameters in children exist with undernutrition, and can be reduced by early nutritional supplementation along with the appropriate environment.

  8. Limits to prediction of energy balance from milk composition measures at individual cow level.

    Science.gov (United States)

    Løvendahl, P; Ridder, C; Friggens, N C

    2010-05-01

    Frequently updated energy balance (EB) estimates for individual cows are especially useful for dairy herd management, and individual-level estimates form the basis for group-level EB estimates. The accuracy of EB estimates determines the value of this information for management decision support. This study aimed to assess EB accuracy through ANOVA components and by comparing EB estimates based either on milk composition (EBalMilk) or on body condition score (BCS) and body weight (BW) (EBalBody). Energy balance based on milk composition was evaluated using data in which milk composition was measured at each milking. Three breeds (Danish Red, Holstein-Friesian, and Jersey) of cows (299 cows, 623 lactations) in parities 1 to 4 were used. Milk data were smoothed using a rolling local regression. Energy balance based on milk composition was calculated using a partial least squares (PLS) model based on milk fat, protein, and lactose contents and yields, and the daily change in these variables at each day. Energy balance based on BCS and BW was calculated from changes in body condition and BW scored weekly or fortnightly. Equations for calculation of EBalMilk and EBalBody used no common variables and were, therefore, assumed mathematically independent. Traits were analyzed within 3 stages of lactation expected to have high mobilization of body tissue (1, early), almost balanced (2), and deposition of body energy (3, mid to late lactation). In general, EBalMilk and EBalBody followed similar expected changes through lactation. Estimates of covariance were obtained using single-trait mixed models with random regression terms describing the change with time and used for calculation of repeatability as intraclass correlations. Within stage, EBalMilk was less repeatable than EBalBody (0.53, 0.41, 0.43 vs. 0.93, 0.91, 0.86, respectively, for stages 1, 2, and 3), mainly because of a larger residual variance for EBalMilk. Correlations between individual-level estimates of EBal

  9. Energy balance from Parana State: 1980-1993; Balanco energetico do Parana: 1980-1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    This energetic balance from the Parana State, Brazil, includes the data referent to the year of 1993. It aims to be a planning tool to the public sector embraced to the energetic question and to orient productive investments to the private sector. It also shows the energetic information during the period of 1980-1993, presenting energetic streams of energetic primary and secondary sources, since its production to the final consumption, according to the main sectors of the economy in the Parana State. The balance is divided in seven chapters, as follows: resume - a synthetic analysis of the energetic sector evolution during the last 14 years and the consolidated data about production, consumption, etc concerning to 1993; energetic supply and demand; energetic interchange transformation centers; another energetic information; energy and socio economy; consolidated energetic balances; and annex - balance structure, information treatment, units, conversion table to medium tEP and specific masses and higher calorific capacities 5 figs., 7 graphs, 1 map, 92 tabs.

  10. Surface energy balance sensitivity to meteorological variability on Haig Glacier, Canadian Rocky Mountains

    Science.gov (United States)

    Ebrahimi, Samaneh; Marshall, Shawn J.

    2016-11-01

    Energy exchanges between the atmosphere and the glacier surface control the net energy available for snow and ice melt. This paper explores the response of a midlatitude glacier in the Canadian Rocky Mountains to daily and interannual variations in the meteorological parameters that govern the surface energy balance. We use an energy balance model to run sensitivity tests to perturbations in temperature, specific humidity, wind speed, incoming shortwave radiation, glacier surface albedo, and winter snowpack depth. Variables are perturbed (i) in isolation, (ii) including internal feedbacks, and (iii) with co-evolution of meteorological perturbations, derived from the North American regional climate reanalysis (NARR) over the period 1979-2014. Summer melt at this site has the strongest sensitivity to interannual variations in temperature, albedo, and specific humidity, while fluctuations in cloud cover, wind speed, and winter snowpack depth have less influence. Feedbacks to temperature forcing, in particular summer albedo evolution, double the melt sensitivity to a temperature change. When meteorological perturbations covary through the NARR forcing, summer temperature anomalies remain important in driving interannual summer energy balance and melt variability, but they are reduced in importance relative to an isolated temperature forcing. Covariation of other variables (e.g., clear skies, giving reduced incoming longwave radiation) may be partially compensating for the increase in temperature. The methods introduced in this paper provide a framework that can be extended to compare the sensitivity of glaciers in different climate regimes, e.g., polar, maritime, or tropical environments, and to assess the importance of different meteorological parameters in different regions.

  11. Improving the energy balance of grass-based anaerobic digestion through combined harvesting and pretreatment

    DEFF Research Database (Denmark)

    Tsapekos, Panagiotis; Kougias, Panagiotis; Egelund, H.

    2017-01-01

    An important challenge that has to be addressed to achieve sustainable anaerobic digestion of lignocellulosic substrates is the development of energy and cost efficient pretreatment methods. Technologies orientated to simultaneously harvest and mechanically pretreat the biomass at the field could...... meet these criteria as they can potentially reduce the energy losses. The objective of this study was to elucidate the effect of two full-scale harvesting machines to enhance the biogas production and subsequently, improve energy balance. The performances of Disc-mower and Excoriator were assessed...... technology. More specifically, Excoriator, which cuts and subsequently applies shearing forces on harvested biomass, enhanced the methane production up to 10% and the overall energy budget was improved proportionally to the driving speed increase....

  12. Improving the energy balance of grass-based anaerobic digestion through harvesting optimization

    DEFF Research Database (Denmark)

    Tsapekos, Panagiotis; Kougias, Panagiotis; Egelund, H.

    to determine the treatment with the best energy balance, the energy demand during harvesting was compared to the practical methane yield. The biomethanation process was evaluated using triplicate batch assays under thermophilic conditions following the guidelines of the biochemical methane potential (BMP...... that the appropriate harvester can improve the energy output by approximately 2.4 GJ/ha under optimal conditions and subsequently, the overall sustainability of grass-based AD....... efficiency is still doubted and thus, they are not widely used in full-scale biogas plants. In addition, these methods are typically associated with increased costs or energy demands. Hence, there is a need to find effective and cost-efficient solutions that boost biomass decomposition. In this concept, one...

  13. Detailed balance condition and effective free energy in the primitive chain network model

    Science.gov (United States)

    Uneyama, Takashi; Masubuchi, Yuichi

    2011-11-01

    We consider statistical mechanical properties of the primitive chain network (PCN) model for entangled polymers from its dynamic equations. We show that the dynamic equation for the segment number of the PCN model does not reduce to the standard Langevin equation which satisfies the detailed balance condition. We propose heuristic modifications for the PCN dynamic equation for the segment number, to make it reduce to the standard Langevin equation. We analyse some equilibrium statistical properties of the modified PCN model, by using the effective free energy obtained from the modified PCN dynamic equations. The PCN effective free energy can be interpreted as the sum of the ideal Gaussian chain free energy and the repulsive interaction energy between slip-links. By using the single chain approximation, we calculate several distribution functions of the PCN model. The obtained distribution functions are qualitatively different from ones for the simple slip-link model without any direct interactions between slip-links.

  14. Load Balancing Metric with Diversity for Energy Efficient Routing in Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Moad, Sofiane; Hansen, Morten Tranberg; Jurdak, Raja;

    2011-01-01

    The expected number of transmission (ETX) represents a routing metric that considers the highly variable link qualities for a specific radio in Wireless Sensor Networks (WSNs). To adapt to these differences, radio diversity is a recently explored solution for WSNs. In this paper, we propose...... to choose an energy efficient radio. In addition, the metric uses the remaining energy of nodes in order to regulate the traffic so that critical nodes are avoided. We show by simulations that our metric can improve the network lifetime up to 20%....... an energy balancing metric which explores the diversity in link qualities present at different radios. The goal is to effectively use the energy of the network and therefore extend the network lifetime. The proposed metric takes into account the transmission and reception costs for a specific radio in order...

  15. Detailed balance condition and effective free energy in the primitive chain network model.

    Science.gov (United States)

    Uneyama, Takashi; Masubuchi, Yuichi

    2011-11-14

    We consider statistical mechanical properties of the primitive chain network (PCN) model for entangled polymers from its dynamic equations. We show that the dynamic equation for the segment number of the PCN model does not reduce to the standard Langevin equation which satisfies the detailed balance condition. We propose heuristic modifications for the PCN dynamic equation for the segment number, to make it reduce to the standard Langevin equation. We analyse some equilibrium statistical properties of the modified PCN model, by using the effective free energy obtained from the modified PCN dynamic equations. The PCN effective free energy can be interpreted as the sum of the ideal Gaussian chain free energy and the repulsive interaction energy between slip-links. By using the single chain approximation, we calculate several distribution functions of the PCN model. The obtained distribution functions are qualitatively different from ones for the simple slip-link model without any direct interactions between slip-links.

  16. The relevance of rooftops: Analyzing the microscale surface energy balance in the Chicago region

    Science.gov (United States)

    Khosla, Radhika

    Spatial structure in climate variables often exist over very short length scales within an urban area, and this structure is a result of various site-specific features. In order to analyze the seasonal and diurnal energy flows that take place at a microclimatic surface, this work develops a semi-empirical energy balance model. For this, radiation fluxes and meteorological measurements are determined by direct observation; sensible heat and latent heat fluxes by parameterizations; and the heat storage flux by a 1-D mechanistic model that allows analysis of the temperature profile and heat storage within an underlying slab. Two sites receive detailed study: an anthropogenic site, being a University of Chicago building rooftop, and a natural site, outside Chicago in the open country. Two identical sets of instruments record measurements contemporaneously from these locations during June-November 2007, the entire period for which analyses are carried out. The study yields seasonal trends in surface temperature, surface-to-air temperature contrast and net radiation. At both sites, a temporal hysteresis between net radiation and heat storage flux indicates that surplus energy absorbed during daylight is released to the atmosphere later in the evening. The surface energy balance model responds well to site specific features for both locations. An analysis of the surface energy balance shows that the flux of sensible heat is the largest non-radiative contributor to the roof's surface cooling, while the flux of latent heat (also referred to as evaporative cooling) is the largest heat sink for the soil layer. In the latter part of the study, the surface energy balance model is upgraded by adding the capability to compute changes in surface temperature and non-radiative fluxes for any specified set of thermal and reflective roof properties. The results of this analysis allow an examination of the relationship between the roof temperature, the heat flux entering the building

  17. Energy balance of chosen crops and their potential to saturate energy consumption in Slovakia

    Directory of Open Access Journals (Sweden)

    Katarína Hrčková

    2016-06-01

    Full Text Available The aim of the present work was to assess and compare energy inputs and outputs of various crop managements in 2011–2012. Two main crops on arable land and three permanent grasslands were investigated. Silage maize (Zea mays L. and winter wheat (Triticum aestivum L. were grown on lowland, whilst two semi-natural grasslands and grassland infested by tufted hair-grass (Deschampsia caespitose (L. P. Beauv were located in mountainous regions of Slovakia. In these crops and grasslands the dry matter yield was measured and subsequently the supplementary energy, energy gain and unifying energy value – tonne of oil equivalent (TOE – were calculated. Silage maize with 233.37 GJ*ha-1 has provided the highest energy gain. In the group of grasslands, grassland infested by tufted hair-grass has offered the highest energy gain (59.77 GJ*ha-1. And this grassland had the lowest requirement on the supplementary energy (3.66 GJ*ha-1, contrary to silage maize with highest one (12.37 GJ*ha-1. The total energy potential of the crop biomasses was confronted with energy consumption in Slovakia. Winter wheat has the biggest energy potential, but it could cover only 19.6% and 11.3% total consumption of electricity or natural gas, respectively. Large area of permanent grasslands and their spatial location make them an important energy reservoir for bioenergy production. But, it is not possible to replace all consumed fossil fuels by bioenergy from these tested renewable energy sources.

  18. Energy balance in weight stable athletes with and without menstrual disorders.

    Science.gov (United States)

    Tomten, S E; Høstmark, A T

    2006-04-01

    The energy balance and nutritional adequacy was assessed in a group of runners with irregular menstrual function (IR, n = 10) and in a comparable group of runners with normal menstrual function (R, n = 10). Based on computerized records of 3 days food intake, the mean content of energy and macronutrients were estimated. Excess energy expenditure (EEE) during training hours was estimated using HF monitoring and individual HF/VO2 nomograms. For the rest of a daily 24 h cycle, estimated values for basal metabolic rate (BMR) and sedentary metabolic rate were applied. Daily training-related excess energy expenditure (2.1 +/- 0.3 vs 2.2 +/- 0.4) MJ (Mean +/- SEM) and total energy expenditure (TEE) (11.0 +/- 0.3 vs 11.2 +/- 0.4) MJ in R vs IR were not different in the two groups. Calculated daily energy intake (EI) was, however, significantly lower in IR (9.7 +/- 0.5 MJ) than in R (12.3 +/- 0.7 MJ), (P = 0.007). Calculated EI and TEE were in balance in R athletes. When the same calculations were applied on IR athletes, a moderate but statistically significant negative energy balance was found (-1.5 +/- 0.6 MJ, P = 0.03). The calculated energy deficit was supported by significantly lower levels of free thyroxine in IR athletes, and may indicate an adaptive lower BMR in IR athletes. Mean intakes of carbohydrates (7.0 g/kg in R and 5.7 g/kg in IR) and protein (1.71 g/kg in R and 1.49 g/kg in IR) were close to guidelines. Intakes were not significantly different in the two groups. The most important difference in macronutrient intake was found in dietary fat (1.70 g/kg in R and 1.04 g/kg in IR) that was significantly lower in the IR group than in the R group (P = 0.007). The weight stable IR and R athletes seemed to meet the recommended intake of carbohydrates, protein and fat in their diet fairly well. However, according to the present calculations, a small energy deficit was observed in IR athletes but not in R athletes. Compared with the intake of the R athletes, this

  19. Brazilian energy balance 2014 - calendar year 2013: final report; Balanco energetico nacional 2014 - ano base 2013: relatorio final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-08-01

    The BEB is divided into eight chapters and ten annexes, whose contents are as follow: Chapter 1- Energy analysis and aggregated data- presents energy highlights per source in 2012 and analyses the evolution of the domestic energy supply and its relationship with economic growth in 2013; Chapter 2- Energy supply and demand by source- has the accountancy, per primary and secondary energy sources, of the production, import, export, variation of stocks, losses, adjustments, disaggregated total per socioeconomic sector in the country; Chapter 3- Energy consumption by sector- presents the final energy consumption classified by primary and secondary source for each sector of the economy; Chapter 4- Energy imports and exports- presents the evolution of the data on the import and export of energy and the dependence on external energy; Chapter 5- Balance of transformation centers- presents the energy balances for the energy transformation centers including their losses; Chapter 6- Energy resources and reserves- has the basic concepts use in the survey of resources and reserves of primary energy sources; Chapter 7- Energy and socioeconomics- contains a comparison of energy, economic and population parameters, specific consumption, energy intensities, average prices and spending on petroleum imports; Chapter 8- State energy data- presents energy data for the states by Federal Unit, main energy source production, energy installations, reserves and hydraulic potential; Relating to annexes the current structure is presented bellow: Annex 1- Installed capacity- shows the installed capacity of electricity generation, the installed capacity of Itaipu hydro plant and the installed capacity for oil refining.; Annex 2- Self-production of electricity- presents disaggregated data of self-production, considering sources and sectors. Annex 3- World energy data- presents the main indicators for the production, import, export and consumption per energy source and region; Annex 4- Useful

  20. Brazilian energy balance 2013 - calendar year 2012: final report; Balanco energetico nacional 2013 - ano base 2012: relatorio final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-07-01

    The BEB is divided into eight chapters and ten annexes, whose contents are as follow: Chapter 1- Energy analysis and aggregated data- presents energy highlights per source in 2012 and analyses the evolution of the domestic energy supply and its relationship with economic growth in 2012; Chapter 2- Energy supply and demand by source- has the accountancy, per primary and secondary energy sources, of the production, import, export, variation of stocks, losses, adjustments, disaggregated total per socioeconomic sector in the country; Chapter 3- Energy consumption by sector- presents the final energy consumption classified by primary and secondary source for each sector of the economy; Chapter 4- Energy imports and exports- presents the evolution of the data on the import and export of energy and the dependence on external energy; Chapter 5- Balance of transformation centers- presents the energy balances for the energy transformation centers including their losses; Chapter 6- Energy resources and reserves- has the basic concepts use in the survey of resources and reserves of primary energy sources; Chapter 7- Energy and socioeconomics- contains a comparison of energy, economic and population parameters, specific consumption, energy intensities, average prices and spending on petroleum imports; Chapter 8- State energy data- presents energy data for the states by Federal Unit, main energy source production, energy installations, reserves and hydraulic potential; Relating to annexes the current structure is presented bellow: Annex 1- Installed capacity- shows the installed capacity of electricity generation, the installed capacity of Itaipu hydro plant and the installed capacity for oil refining; Annex 2- Self-production of electricity- presents disaggregated data of self-production, considering sources and sectors. Annex 3- World energy data- presents the main indicators for the production, import, export and consumption per energy source and region; Annex 4- Useful

  1. Energy balance, nitrogen balance, and growth in preterm infants fed expressed breast milk, a premature infant formula, and two low-solute adapted formulae.

    Science.gov (United States)

    Brooke, O G; Wood, C; Barley, J

    1982-12-01

    Energy balance, nitrogen balance, and growth studies were done in 37 preterm infants (20 of very low birthweight) who were fed on expressed breast milk or on one of 3 formulae each of different composition, including a special premature formula and a highly adapted 'humanised' formula. The variability of breast milk composition was such that it would have been difficult to predict the infants' protein and energy intakes under normal nursing conditions. All measured parameters of nutritional performance were best in infants fed on the 'premature' formula and were reflected in greater weight gain, linear growth, and head growth. The nitrogen balance data suggest that the highly adapted formula, which had a protein content comparable with that of mature human milk, contained too little protein for small preterm infants.

  2. Analysis of climate change impacts on surface energy balance of Lake Huron (estimation of surface energy balance components: Remote sensing approach for water -- atmosphere parameterization)

    Science.gov (United States)

    Petchprayoon, Pakorn

    The purpose of this thesis was to investigate the physical processes of energy exchange between the water surface and atmosphere of Lake Huron in order to explain the processes behind such changes in long-term water levels and to monitor their spatial and temporal fluctuations. The lake surface water temperature and the four components of surface energy balance, including net radiation, latent heat, sensible heat, and heat storage, as well as evaporation rate, were estimated using the daily remotely sensed data from eleven years (2002--2012) with a multi-spatial resolution of 1 km to 5 km using the Moderate Resolution Imaging Spectroradiometer (MODIS) on board Terra satellite, together with in-situ measurements. The regression analysis of the entire lake daily mean water surface temperature revealed a positive trend of 0.1 °C per year, indicating that the lake surface temperature increased by 1.1°C during the period 2002-2012. The warming rate was found to be greatest in the deepest areas of the lake, with a statistically-significant correlation between warming rate and depth. The four components of surface energy balance showed temporal and spatial heterogeneities. There were strong seasonal patterns for all of the components, which were very high in summer and low in winter for net radiation and heat storage. In contrast, the latent heat and sensible heat were very high in the winter and very low in the summer. Approximately 70% of the annual mean 30 min evaporation occurred during the fall and winter seasons, whereas the lowest evaporation rate occurred in March, which was only 3% of the annual mean of 30 min evaporation. There was an increase in the evaporation rate of approximately 1.4 mm m-2 over the 2005--2012 observation period, the water level decreased by 0.04 m during the period 2002--2012, and there was a decrease in total water storage by 1.18 cm during the entire study period (2004--2012). There was obviously a negative correlation between lake

  3. Energy Balance, Evapo-transpiration and Dew deposition in the Dead Sea Valley

    Science.gov (United States)

    Metzger, Jutta; Corsmeier, Ulrich

    2016-04-01

    The Dead Sea is a unique place on earth. It is a terminal hypersaline lake, located at the lowest point on earth with a lake level of currently -429 m above mean sea level (amsl). It is located in a transition zone of semiarid to arid climate conditions, which makes it highly sensible to climate change (Alpert1997, Smiatek2011). The Virtual Institute DEad SEa Research Venue (DESERVE) is an international project funded by the German Helmholtz Association and was established to study coupled atmospheric hydrological, and lithospheric processes in the changing environment of the Dead Sea. At the moment the most prominent environmental change is the lake level decline of approximately 1 m / year due to anthropogenic interferences (Gertman, 2002). This leads to noticeable changes in the fractions of the existing terrestrial surfaces - water, bare soil and vegetated areas - in the valley. Thus, the partitioning of the net radiation in the valley changes as well. To thoroughly study the atmospheric and hydrological processes in the Dead Sea valley, which are driven by the energy balance components, sound data of the energy fluxes of the different surfaces are necessary. Before DESERVE no long-term monitoring network simultaneously measuring the energy balance components of the different surfaces in the Dead Sea valley was available. Therefore, three energy balance stations were installed at three characteristic sites at the coast-line, over bare soil, and within vegetation, measuring all energy balance components by using the eddy covariance method. The results show, that the partitioning of the energy into sensible and latent heat flux on a diurnal scale is totally different at the three sites. This results in gradients between the sites, which are e.g. responsible for the typical diurnal wind systems at the Dead Sea. Furthermore, driving forces of evapo-transpiration at the sites were identified and a detailed analysis of the daily evaporation and dew deposition rates

  4. HERschel Observations of Edge-on Spirals (HEROES). III. Dust energy balance study of IC 2531

    CERN Document Server

    Mosenkov, Aleksandr V; Baes, Maarten; Bianchi, Simone; Camps, Peter; De Geyter, Gert; De Looze, Ilse; Fritz, Jacopo; Gentile, Gianfranco; Hughes, Thomas M; Lewis, Fraser; Verstappen, Joris; Verstocken, Sam; Viaene, Sébastien

    2016-01-01

    We investigate the dust energy balance for the edge-on galaxy IC 2531, one of the seven galaxies in the HEROES sample. We perform a state-of-the-art radiative transfer modelling based, for the first time, on a set of optical and near-infrared galaxy images. We show that taking into account near-infrared imaging in the modelling significantly improves the constraints on the retrieved parameters of the dust content. We confirm the result from previous studies that including a young stellar population in the modelling is important for explaining the observed stellar energy distribution. However, the discrepancy between the observed and modelled thermal emission at far-infrared wavelengths, the so-called dust energy balance problem, is still present: the model underestimates the observed fluxes by a factor of about two. We compare two different dust models, and find that dust parameters and thus the spectral energy distribution in the infrared domain are sensitive to the adopted dust model. In general, the THEMIS...

  5. Energy and greenhouse balance of photocatalytic CO2 conversion to methanol

    Science.gov (United States)

    Haumann, D.; Goettlicher, G.; Muench, W.

    2012-10-01

    Within the Leading-Edge Cluster "Forum Organic Electronic", the research project "Solar2Fuel" funded by the German Ministry of education and research (BMBF) (2009 - 2012), EnBW, BASF, Karlsruhe Institute of Technology and Ruprecht-Karls-University of Heidelberg aim to develop a future solar powered CO2 to methanol conversion technology. CO2 from stationary sources such as power plants shall be catalytically converted together with water to a product such as methanol by use of solar irradiation. For this purpose a catalyst shall be developed. EnBW investigates the required boundary conditions to make such a principle interesting with respect to energy and greenhouse gas balance as well as economic evaluations. The assessment of boundary conditions includes the analysis of the whole chain from power generation, CO2 capture and transport, a virtual photocatalytic reactor, the product purification and use in the traffic sector. Most important technical factors of the process such as CO2 conversion efficiency is presented. CO2 capturing and liquefaction are the most energy intensive process steps, CO2 transport in pipeline is highly energy efficient and depending on energy need of the photoconversion step and the product purification, the overall greenhouse gas balance is comparable with the underground storage of the captured CO2.

  6. Energy and greenhouse balance of photocatalytic CO2 conversion to methanol

    Directory of Open Access Journals (Sweden)

    Muench W.

    2012-10-01

    Full Text Available Within the Leading-Edge Cluster “Forum Organic Electronic”, the research project “Solar2Fuel” funded by the German Ministry of education and research (BMBF (2009 – 2012, EnBW, BASF, Karlsruhe Institute of Technology and Ruprecht-Karls-University of Heidelberg aim to develop a future solar powered CO2 to methanol conversion technology. CO2 from stationary sources such as power plants shall be catalytically converted together with water to a product such as methanol by use of solar irradiation. For this purpose a catalyst shall be developed. EnBW investigates the required boundary conditions to make such a principle interesting with respect to energy and greenhouse gas balance as well as economic evaluations. The assessment of boundary conditions includes the analysis of the whole chain from power generation, CO2 capture and transport, a virtual photocatalytic reactor, the product purification and use in the traffic sector. Most important technical factors of the process such as CO2 conversion efficiency is presented. CO2 capturing and liquefaction are the most energy intensive process steps, CO2 transport in pipeline is highly energy efficient and depending on energy need of the photoconversion step and the product purification, the overall greenhouse gas balance is comparable with the underground storage of the captured CO2.

  7. Pyrolysis and gasification of meat-and-bone-meal: Energy balance and GHG accounting

    Energy Technology Data Exchange (ETDEWEB)

    Cascarosa, Esther [Thermochemical Processes Group, Aragón Institute for Engineering Research (I3A), Universidad de Zaragoza (Spain); Boldrin, Alessio, E-mail: aleb@env.dtu.dk [Department of Environmental Engineering. Technical University of Denmark, Kongens Lyngby (Denmark); Astrup, Thomas [Department of Environmental Engineering. Technical University of Denmark, Kongens Lyngby (Denmark)

    2013-11-15

    Highlights: • GHG savings are in the order of 600–1000 kg CO{sub 2}-eq. per Mg of MBM treated. • Energy recovery differed in terms of energy products and efficiencies. • The results were largely determined by use of the products for energy purposes. - Abstract: Meat-and-bone-meal (MBM) produced from animal waste has become an increasingly important residual fraction needing management. As biodegradable waste is routed away from landfills, thermo-chemical treatments of MBM are considered promising solution for the future. Pyrolysis and gasification of MBM were assessed based on data from three experimental lab and pilot-scale plants. Energy balances were established for the three technologies, providing different outcomes for energy recovery: bio-oil was the main product for the pyrolysis system, while syngas and a solid fraction of biochar were the main products in the gasification system. These products can be used – eventually after upgrading – for energy production, thereby offsetting energy production elsewhere in the system. Greenhouse gases (GHG) accounting of the technologies showed that all three options provided overall GHG savings in the order of 600–1000 kg CO{sub 2}-eq. per Mg of MBM treated, mainly as a consequence of avoided fossil fuel consumption in the energy sector. Local conditions influencing the environmental performance of the three systems were identified, together with critical factors to be considered during decision-making regarding MBM management.

  8. Ethanol vehicle fuel : energy balance, GHG reductions, supply and economic overview

    Energy Technology Data Exchange (ETDEWEB)

    Rilett, J.

    2003-04-15

    This paper examined the following four aspects of ethanol vehicle fuels: energy balance of ethanol, potential for greenhouse gas (GHG) reductions, Canadian production capacity based on available ethanol feedstock, and an overview of the economic issues in the Canadian ethanol industry. All recent research conducted by private consulting firms, government researchers in Canada and the United States, and academia indicate that ethanol presents a positive energy balance. Only one recent study concludes that ethanol has a negative energy balance. It was argued that this conclusion was reached because the data was outdated and improper assumptions were made concerning energy inputs for the production of ethanol. Researchers indicate that ethanol as a vehicle fuel yields GHG emission reductions. Mixtures of 10 per cent ethanol and 90 per cent gasoline (E10) result in GHG reductions estimated in the 1 to 5 per cent range when compared to pure gasoline. The same estimates suggest that if all gasoline sold in Alberta was an E10 blend, the minimum reduction of GHG emissions would be approximately 103,220 tonnes of carbon dioxide equivalent. In this paper, wheat was considered as a feed stock, and numbers indicate that 4.6 million tonnes of wheat would be suitable for ethanol feedstock, exceeding the government goal of having 35 per cent of all gasoline as E10 blend. Corn produced in eastern Canada would also increase available feedstock. A large ethanol industry in Canada would require fuel tax exemptions and mandatory blending percentages to make it a viable market. 20 refs., 4 tabs., 1 fig.

  9. Utilizing hydropower for load balancing non-storable renewable energy sources - technical and environmental challenges

    Science.gov (United States)

    Alfredsen, K. T.; Killingtveit, A.

    2011-12-01

    About 99% of the total energy production in Norway comes from hydropower, and the total production of about 120 TWh makes Norway Europe's largest hydropower producer. Most hydropower systems in Norway are based on high-head plants with mountain storage reservoirs and tunnels transporting water from the reservoirs to the power plants. In total, Norwegian reservoirs contributes around 50% of the total energy storage capacity in Europe. Current strategies to reduce emission of greenhouse gases from energy production involve increased focus on renewable energy sources, e.g. the European Union's 202020 goal in which renewable energy sources should be 20% of the total energy production by 2020. To meet this goal new renewable energy installations must be developed on a large scale in the coming years, and wind power is the main focus for new developments. Hydropower can contribute directly to increase renewable energy through new development or extensions to existing systems, but maybe even more important is the potential to use hydropower systems with storage for load balancing in a system with increased amount of non-storable renewable energies. Even if new storage technologies are under development, hydro storage is the only technology available on a large scale and the most economical feasible alternative. In this respect the Norwegian system has a high potential both through direct use of existing reservoirs and through an increased development of pump storage plants utilizing surplus wind energy to pump water and then producing during periods with low wind input. Through cables to Europe, Norwegian hydropower could also provide balance power for the North European market. Increased peaking and more variable operation of the current hydropower system will present a number of technical and environmental challenges that needs to be identified and mitigated. A more variable production will lead to fluctuating flow in receiving rivers and reservoirs, and it will also

  10. Energy balance of the metropolitan zone of the valley of Mexico, methodology and the entailment energy-air quality; Balance de energia de la zona metropolitana del valle de Mexico metodologia y la vinculacion energia - calidad del aire

    Energy Technology Data Exchange (ETDEWEB)

    Bazan Navarrete, Gerardo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2001-07-01

    The present document raises a methodology for the elaboration of the Energy Balance of the Metropolitan Zone of the Valley of Mexico (ZMVM), in order to unify criteria and to facilitate the work of entities and investigators, mainly of those that require the entailment of energy and environment. The applied methodology, the consolidated format and the caloric unity facilitates the insertion of the Energy Balance of the ZMVM within the National Balance of Energy. The regional balances of energy have the intention of knowing the energy consumption patterns in the ZMVM and the indexes of energy intensity by sector. They establish the relationship of the indexes of energy intensity with the local and global air quality of the region, performing studies of incidence with the main polluting agents and with the greenhouse effect gases. [Spanish] El presente documento plantea una metodologia para la elaboracion del Balance de Energia de la Zona Metropolitana del Valle de Mexico (ZMVM), con el proposito de unificar criterios y facilitar el trabajo de organismos e investigadores, sobre todo de aquellos que requieren vincular energia y medio ambiente. La metodologia aplicad, el formato consolidado y la unidad calorica facilitan la insercion del Balance de Energia de la ZMVM dentro del Balance Nacional de Energia. Los balances regionales de energia tienen el proposito de conocer los patrones de consumo de energia en la ZMVM y los indices de intensidad energetica por sector. Establecen la relacion de los indices de intensidad energetica con la calidad del aire local y global de la region, realizando estudios de incidencia con los principales contaminantes y con los gases de efecto invernadero.

  11. Meridional trends in the radiative energy balance of the Venus mesosphere

    Science.gov (United States)

    Lee, Y. J.; Titov, D.; Ignatiev, N.; Tellmann, S.; Paetzold, M.; Piccioni, G.

    2012-04-01

    The Venus clouds play an important role in the radiative energy balance. Thermal cooling to space occurs from the cloud tops. Also almost half of the solar energy received by Venus is deposited at about the same altitude by the unknown UV absorber. Observations revealed the latitudinal trend in the aerosol structure with cloud top altitude decreasing from ~68 km in low latitudes to ~62 km in polar region and aerosol scale height changing from ~4 km to ~1-2 km. This results in significant changes in the radiative energy balance at the cloud tops and the mesosphere as well as global energy balance of the planet. Here we present calculations of the thermal flux in the 0-99 km altitude range using the latitude dependent cloud top structure. Aerosol and temperature profiles are based on the radio science experiment (VeRa) and the thermal spectrometer (VIRTIS) onboard Venus Express [1]. We used radiative transfer model merged with a fast line-by-line routine to calculate thermal fluxes in the broad wavenumber range from 50 to 2590 cm-1 (=3.86-200.0 μm). The cloud layers are responsible for thermal cooling below ~70 km altitude. The meridional changes in the upper clouds result in cooling rate variation 6-10 K/day along the latitude. Contribution of the CO2 emission to the outgoing flux becomes dominant above 70 km altitude. The outgoing flux shows maxima at equator (164 W/m2) and pole (171 W/m2) and a minimum (133 W/m2) in the "cold collar" region (50-60° S). The earlier studies of the solar heating rate were used to derive a meridional trend of the radiative energy balance. The comparison shows dominant thermal cooling in high latitudes and strong solar heating at low latitudes suggesting radiative disequilibrium, that implies a need for another, possibly dynamical, mechanism to maintain the observed temperature and cloud structure [2,3].

  12. Energy method for multi-dimensional balance laws with non-local dissipation

    KAUST Repository

    Duan, Renjun

    2010-06-01

    In this paper, we are concerned with a class of multi-dimensional balance laws with a non-local dissipative source which arise as simplified models for the hydrodynamics of radiating gases. At first we introduce the energy method in the setting of smooth perturbations and study the stability of constants states. Precisely, we use Fourier space analysis to quantify the energy dissipation rate and recover the optimal time-decay estimates for perturbed solutions via an interpolation inequality in Fourier space. As application, the developed energy method is used to prove stability of smooth planar waves in all dimensions n2, and also to show existence and stability of time-periodic solutions in the presence of the time-periodic source. Optimal rates of convergence of solutions towards the planar waves or time-periodic states are also shown provided initially L1-perturbations. © 2009 Elsevier Masson SAS.

  13. Numerical modeling of sandwich panel response to ballistic loading - energy balance for varying impactor geometries

    DEFF Research Database (Denmark)

    Kepler, Jørgen Asbøl; Hansen, Michael Rygaard

    2007-01-01

    A sandwich panel is described by an axisymmetric lumped mass- spring model. The panel compliance is simplified, considering only core shear deformation uniformly distributed across the core thickness. Transverse penetrating impact is modeled for impactors of diameters comparable to the panel...... thickness but significantly smaller than panel length dimensions. Experimental data for the total loss in impactor kinetic energy and momentum and estimated damage energy are described. For a selection of impactor tip shapes, the numerical model is used to evaluate different simplified force histories...... between the impactor and the panel during penetration. The force histories are selected from a primary criterion of conservation of linear momentum in the impactor-panel system, and evaluated according to agreement with the total measured energy balance....

  14. Spatiotemporal variability in surface energy balance across tundra, snow and ice in Greenland

    DEFF Research Database (Denmark)

    Lund, Magnus; Stiegler, Christian; Abermann, Jakob

    2017-01-01

    The surface energy balance (SEB) is essential for understanding the coupled cryosphere–atmosphere system in the Arctic. In this study, we investigate the spatiotemporal variability in SEB across tundra, snow and ice. During the snow-free period, the main energy sink for ice sites is surface melt....... For tundra, energy is used for sensible and latent heat flux and soil heat flux leading to permafrost thaw. Longer snow-free period increases melting of the Greenland Ice Sheet and glaciers and may promote tundra permafrost thaw. During winter, clouds have a warming effect across surface types whereas during...... summer clouds have a cooling effect over tundra and a warming effect over ice, reflecting the spatial variation in albedo. The complex interactions between factors affecting SEB across surface types remain a challenge for understanding current and future conditions. Extended monitoring activities coupled...

  15. Spatiotemporal variability in surface energy balance across tundra, snow and ice in Greenland.

    Science.gov (United States)

    Lund, Magnus; Stiegler, Christian; Abermann, Jakob; Citterio, Michele; Hansen, Birger U; van As, Dirk

    2017-02-01

    The surface energy balance (SEB) is essential for understanding the coupled cryosphere-atmosphere system in the Arctic. In this study, we investigate the spatiotemporal variability in SEB across tundra, snow and ice. During the snow-free period, the main energy sink for ice sites is surface melt. For tundra, energy is used for sensible and latent heat flux and soil heat flux leading to permafrost thaw. Longer snow-free period increases melting of the Greenland Ice Sheet and glaciers and may promote tundra permafrost thaw. During winter, clouds have a warming effect across surface types whereas during summer clouds have a cooling effect over tundra and a warming effect over ice, reflecting the spatial variation in albedo. The complex interactions between factors affecting SEB across surface types remain a challenge for understanding current and future conditions. Extended monitoring activities coupled with modelling efforts are essential for assessing the impact of warming in the Arctic.

  16. Combining Flux Balance and Energy Balance Analysis for Large-Scale Metabolic Network: Biochemical Circuit Theory for Analysis of Large-Scale Metabolic Networks

    Science.gov (United States)

    Beard, Daniel A.; Liang, Shou-Dan; Qian, Hong; Biegel, Bryan (Technical Monitor)

    2001-01-01

    Predicting behavior of large-scale biochemical metabolic networks represents one of the greatest challenges of bioinformatics and computational biology. Approaches, such as flux balance analysis (FBA), that account for the known stoichiometry of the reaction network while avoiding implementation of detailed reaction kinetics are perhaps the most promising tools for the analysis of large complex networks. As a step towards building a complete theory of biochemical circuit analysis, we introduce energy balance analysis (EBA), which compliments the FBA approach by introducing fundamental constraints based on the first and second laws of thermodynamics. Fluxes obtained with EBA are thermodynamically feasible and provide valuable insight into the activation and suppression of biochemical pathways.

  17. The Effects of Ghrelin on Energy Balance and Psychomotor Activity in a Goldfish Model: An Overview

    Directory of Open Access Journals (Sweden)

    Ki Sung Kang

    2011-01-01

    Full Text Available The goldfish (Carassius auratus has a number of merits as a laboratory animal, and we have extensively identified the mechanisms by which ghrelin regulates food intake in this species. For the first time, we have purified and characterized 11 molecular variants of ghrelin that are present in goldfish intestine and shown that 17-residue ghrelin, the predominant form with n-octanoyl modification, is biologically active and implicated in the regulation of food intake as an endogenous orexigenic factor. Ghrelin and its receptor system are present not only in peripheral tissues such as stomach and intestine, but also in the central nervous system. Recent studies have also revealed that a number of neuropeptides are widely distributed in the brain in key areas of emotional regulation, and their role as modulators of behavioral states is being increasingly recognized. Interestingly, administration of ghrelin induces an orexigenic effect and also modifies locomotor activity, suggesting the involvement of ghrelin in feeding control and regulation of energy balance. Information derived from studies of ghrelin has been increasing, and important results have been obtained from both fish and mammals. Here, we present an overview of the effects of ghrelin on energy balance and psychomotor activity in the goldfish as an animal model. The available data provide an insight into evolutionary background of ghrelin's multiple actions on energy homeostasis in vertebrates.

  18. Energy balance model applied to pasture experimental areas in São Paulo State, Brazil

    Science.gov (United States)

    Bayma-Silva, Gustavo; de Castro Teixeira, Antonio Heriberto; de Castro Victoria, Daniel; Furlan Nogueira, Sandra; Freitas Leivas, Janice; Coaguila, Daniel N.; Rodrigues Herling, Valdo

    2016-10-01

    The Simple Algorithm for Evapotranspiration Retrieving (SAFER) was used to estimate biophysical parameters and the energy balance components in two different pasture experimental areas, in the São Paulo state, Brazil. The experimental pastures consist in six rotational (RGS) and three continuous grazing systems (CGS) paddocks. Landsat-8 images from 2013 and 2015 dry and rainy seasons were used, as these presented similar hydrological cycle, with 1,600 mm and 1,613 mm of annual precipitation, resulting in 19 cloud-free images. Bands 1 to 7 and thermal bands 10 and 11 were used with weather data from a station located near the experimental area. NDVI, biomass, evapotranspiration and latent heat flux (λE) temporal values statistically differ CGS from RGS areas. Grazing systems influences the energy partition and these results indicate that RGS benefits biomass production, evapotranspiration and the microclimate, due higher LE values. SAFER is a feasible tool to estimate biophysical parameters and energy balance components in pasture and has potential to discriminate continuous and rotation grazing systems in a temporal analysis.

  19. Effect of the Lower Boundary Position of the Fourier Equation on the Soil Energy Balance

    Institute of Scientific and Technical Information of China (English)

    孙菽芬; 张霞

    2004-01-01

    In this study, the effect of the lower boundary position selection for the Fourier equation on heat transfer and energy balance in soil is evaluated. A detailed numerical study shows that the proper position of the lower boundary is critical when solving the Fourier equation by using zero heat flux as the lower boundary condition. Since the position defines the capacity of soil as a heat sink or source, which absorbs and stores radiation energy from the sky in summer and then releases the energy to the atmosphere in winter, and regulates the deep soil temperature distribution, the depth of the position greatly influences the heat balance within the soil as well as the interaction between the soil and the atmosphere. Based on physical reasoning and the results of numerical simulation, the proper depth of the position should be equal to approximately 3 times of the annual heat wave damping depth. For most soils, the proper lower boundary depth for the Fourier equation should be around 8 m to 15 m, depending on soil texture.

  20. Assessment of green roof systems in terms of water and energy balance

    Directory of Open Access Journals (Sweden)

    Mert Ekşi

    2016-01-01

    Full Text Available Green roofs concept term is used for extensive green roofs which are planted with herbaceous plants that can be adapted into changeable environmental conditions on a shallow substrate layer, require minimal maintenance, installed for their benefits to building and urban scale. Main objective of this study is to determine the characteristics of a green roof such as thermal insulation, water holding capacity, runoff characteristics, plant growth and its interaction with environmental factors in Istanbul climate conditions by performing comparative measurements. In this study, a research site (IU Green Roof Research Station was founded to assess water and energy balance of green roofs. Thus, a typical green roof was evaluated in terms of water and energy balance and its interaction with the building and city was determined. energy efficiency of green roof system was 77% higher than reference roof. Temperature fluctuations on green roof section of the roof were 79% lower. In addition, green roof retained 12,8% - 100% of precipitation and delayed runoff up to 23 hours depending on water content of substrate.

  1. Nutrient-sensing nuclear receptors PPARα and FXR control liver energy balance.

    Science.gov (United States)

    Preidis, Geoffrey A; Kim, Kang Ho; Moore, David D

    2017-04-03

    The nuclear receptors PPARα (encoded by NR1C1) and farnesoid X receptor (FXR, encoded by NR1H4) are activated in the liver in the fasted and fed state, respectively. PPARα activation induces fatty acid oxidation, while FXR controls bile acid homeostasis, but both nuclear receptors also regulate numerous other metabolic pathways relevant to liver energy balance. Here we review evidence that they function coordinately to control key nutrient pathways, including fatty acid oxidation and gluconeogenesis in the fasted state and lipogenesis and glycolysis in the fed state. We have also recently reported that these receptors have mutually antagonistic impacts on autophagy, which is induced by PPARα but suppressed by FXR. Secretion of multiple blood proteins is a major drain on liver energy and nutrient resources, and we present preliminary evidence that the liver secretome may be directly suppressed by PPARα, but induced by FXR. Finally, previous studies demonstrated a striking deficiency in bile acid levels in malnourished mice that is consistent with results in malnourished children. We present evidence that hepatic targets of PPARα and FXR are dysregulated in chronic undernutrition. We conclude that PPARα and FXR function coordinately to integrate liver energy balance.

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

    Science.gov (United States)

    Khasawneh, Hussam J.; Illindala, Mahesh S.

    2014-09-01

    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.

  3. Hindbrain DPP-IV inhibition improves glycemic control and promotes negative energy balance.

    Science.gov (United States)

    Mietlicki-Baase, Elizabeth G; McGrath, Lauren E; Koch-Laskowski, Kieran; Krawczyk, Joanna; Pham, Tram; Lhamo, Rinzin; Reiner, David J; Hayes, Matthew R

    2017-01-22

    The beneficial glycemic and food intake-suppressive effects of glucagon-like peptide-1 (GLP-1) have made this neuroendocrine system a leading target for pharmacological approaches to the treatment of diabetes and obesity. One strategy to increase the activity of endogenous GLP-1 is to prevent the rapid degradation of the hormone by the enzyme dipeptidyl peptidase-IV (DPP-IV). However, despite the expression of both DPP-IV and GLP-1 in the brain, and the clear importance of central GLP-1 receptor (GLP-1R) signaling for glycemic and energy balance control, the metabolic effects of central inhibition of DPP-IV activity are unclear. To test whether hindbrain DPP-IV inhibition suppresses blood glucose, feeding, and body weight gain, the effects of 4th intracerebroventricular (ICV) administration of the FDA-approved DPP-IV inhibitor sitagliptin were evaluated. Results indicate that hindbrain delivery of sitagliptin improves glycemic control in a GLP-1R-dependent manner, suggesting that this effect is due at least in part to increased endogenous brainstem GLP-1 activity after sitagliptin administration. Furthermore, 4th ICV injection of sitagliptin reduced 24h body weight gain and energy intake, with a selective suppression of high-fat diet, but not chow, intake. These data reveal a novel role for hindbrain GLP-1R activation in glycemic control and also demonstrate that DPP-IV inhibition in the caudal brainstem promotes negative energy balance.

  4. Botswana water and surface energy balance research program. Part 1: Integrated approach and field campaign results

    Science.gov (United States)

    Vandegriend, A. A.; Owe, M.; Vugts, H. F.; Ramothwa, G. K.

    1992-01-01

    The Botswana water and surface energy balance research program was developed to study and evaluate the integrated use of multispectral satellite remote sensing for monitoring the hydrological status of the Earth's surface. Results of the first part of the program (Botswana 1) which ran from 1 Jan. 1988 - 31 Dec. 1990 are summarized. Botswana 1 consisted of two major, mutually related components: a surface energy balance modeling component, built around an extensive field campaign; and a passive microwave research component which consisted of a retrospective study of large scale moisture conditions and Nimbus scanning multichannel microwave radiometer microwave signatures. The integrated approach of both components in general are described and activities performed during the surface energy modeling component including the extensive field campaign are summarized. The results of the passive microwave component are summarized. The key of the field campaign was a multilevel approach, whereby measurements by various similar sensors were made at several altitudes and resolution. Data collection was performed at two adjacent sites of contrasting surface character. The following measurements were made: micrometeorological measurements, surface temperatures, soil temperatures, soil moisture, vegetation (leaf area index and biomass), satellite data, aircraft data, atmospheric soundings, stomatal resistance, and surface emissivity.

  5. Effect of energy balance profiles on metabolic and reproductive response in Holstein and Swedish Red cows.

    Science.gov (United States)

    Ntallaris, T; Humblot, P; Båge, R; Sjunnesson, Y; Dupont, J; Berglund, B

    2017-03-01

    This study examined the effect of two feeding levels during the antepartum and postpartum period on reproductive performance and blood metabolites (glucose, non-esterified fatty acids (NEFA), insulin) in primiparous Holstein and Swedish Red (SRB) cows, in order to identify possible differences in the way these breeds respond to negative energy balance after calving. A total of 44 cows (22 Holstein, 22 SRB) kept in a loose housing system were included in the study. The control group (HE, n = 23) was fed a diet for high-producing cows (target 35 kg/d energycorrected milk, ECM). A lower feeding intensity (LE, n = 21) was achieved by giving -50% concentrate to target 25 kg/d ECM. Diets were implemented 30 days before expected calving and the cows were monitored for 120 days postpartum. Milk yield and composition, dry matter intake (DMI), live body weight and body condition score (BCS) were assessed to calculate the weekly energy balance (residual feed intake). Blood sampling started before diet implementation and was repeated every 2 weeks until Day 60 postpartum and then once monthly until Day 120. Plasma was kept at -20 °C until analysis for glucose, insulin and NEFA concentrations. Mixed linear models were used to analyse data (SAS 9.3; PROC MIXED). Holstein cows had lower mean energy balance than SRB cows (-4.7 ± 1.4 and -0.9 ± 1.4 MJ, respectively; p = 0.05). SRB cows had higher (pbalanced metabolic profile.

  6. The endocannabinoid system as a link between homoeostatic and hedonic pathways involved in energy balance regulation.

    Science.gov (United States)

    Di Marzo, V; Ligresti, A; Cristino, L

    2009-06-01

    The endocannabinoid system (ECS) and, in particular, cannabinoid CB(1) receptors, their endogenous agonists (the endocannabinoids anandamide and 2-arachidonoylglycerol) and enzymes for the biosynthesis and degradation of the latter mediators are emerging as key players in the control of all aspects of food intake and energy balance. The ECS is involved in stimulating both the homoeostatic (that is, the sensing of deficient energy balance and gastrointestinal load) and the hedonic (that is, the sensing of the salience and the incentive/motivational value of nutrients) aspects of food intake. The orexigenic effects of endocannabinoids are exerted in the brain by CB(1)-mediated stimulatory and inhibitory effects on hypothalamic orexigenic and anorectic neuropeptides, respectively; by facilitatory actions on dopamine release in the nucleus accumbens shell; and by regulating the activity of sensory and vagal fibres in brainstem-duodenum neural connections. In turn, the levels of anandamide and 2-arachidonoylglycerol and/or CB(1) receptors in the brain are under the control of leptin, ghrelin and glucocorticoids in the hypothalamus, under that of dopamine in the limbic forebrain and under that of cholecystokinin and ghrelin in the brainstem. These bi-directional communications between the ECS and other key players in energy balance ensure local mediators such as the endocannabinoids to act in a way coordinated in both 'space' and 'time' to enhance food intake, particularly after a few hours of food deprivation. Alterations of such communications are, however, also among the underlying causes of overactivity of the ECS in hyperphagia and obesity, a phenomenon that provided the rationale for the development of anti-obesity drugs from CB(1) receptor antagonists.

  7. Energy and water balance response of a vegetated wetland to herbicide treatment of invasive Phragmites australis

    Science.gov (United States)

    Mykleby, Phillip M.; Lenters, John D.; Cutrell, Gregory J.; Herrman, Kyle S.; Istanbulluoglu, Erkan; Scott, Durelle T.; Twine, Tracy E.; Kucharik, Christopher J.; Awada, Tala; Soylu, Mehmet E.; Dong, Bo

    2016-08-01

    The energy and water balance of a Phragmites australis dominated wetland in south central Nebraska was analyzed to assess consumptive water use and the potential for "water savings" as a result of vegetation eradication via herbicide treatment. Energy balance measurements were made at the field site for two growing seasons (treated and untreated), including observations of net radiation, heat storage, and sensible heat flux, which was measured using a large-aperture scintillometer. Latent heat flux was calculated as a residual of the energy balance, and comparisons were made between the two growing seasons and with model simulations to examine the relative impacts of vegetation removal and climate variability. Observed ET rates dropped by roughly 32% between the two growing seasons, from a mean of 4.4 ± 0.7 mm day-1 in 2009 (with live vegetation) to 3.0 ± 0.8 mm day-1 in 2010 (with dead P. australis). These results are corroborated by the Agro-IBIS model simulations, and the reduction in ET implies a total "water savings" of 245 mm over the course of the growing season. The significant decreases in ET were accompanied by a more-than-doubling of sensible heat flux, as well as a ∼60% increase in heat storage due to decreased LAI. Removal of P. australis was also found to cause measurable changes in the local micrometeorology at the wetland. Consistent with the observed increase in sensible heat flux during 2010, warmer, drier, windier conditions were observed in the dead, P. australis section of the wetland, compared to an undisturbed section of live, native vegetation. Modeling results suggest that the elimination of transpiration in 2010 was partially offset by an increase in surface evaporation, thereby reducing the subsequent water savings by roughly 60%. Thus, the impact of vegetation removal depends on the local climate, depth to groundwater, and management decisions related to regrowth of vegetation.

  8. Influence of different fibre sources on digestibility and nitrogen and energy balances in growing pigs

    DEFF Research Database (Denmark)

    Hansen, Michael Jørgen; Chwalibog, André; Tauson, Anne-Helene

    2006-01-01

    The present study was undertaken to investigate how three different fibre sources, sugar beet pulp, soya bean hulls and pectin residue, constituting 15% of diets for growing pigs, influenced daily body gain, feed conversion, apparent faecal digestibility and nitrogen and energy balances. Eight......, soya bean hulls and pectin residue in diets for growing pigs decreased the apparent faecal digestibility and in the diets with sugar beet pulp and pectin residue higher utilization of digested nitrogen for retention compensated for the lower amount of digested nitrogen....

  9. Simulation of the Earth's gravitational field recovery from GRACE using the energy balance approach

    Institute of Scientific and Technical Information of China (English)

    ZHENG Wei; LU Xiaolei; HSU Houtse; SHAO Chenggang; LUO Jun; WANG Nengchao

    2005-01-01

    Based on the measurement principles of GRACE satellites, the observation equations are set up using the energy balance approach. The Earth's gravitational field complete up to degree and order 120 is recovered applying the preconditioning conjugate gradient iterative approach by numerical simulation. Assuming an accuracy of 1?m/s in range-rate measurements of the K-band microwave ranging system, the matching relationships of accuracies of K-band microwave ranging system, SuperSTAR Accelerometer, position vector and velocity vector measurements are investigated.

  10. Coordinated Secondary Control for Balanced Discharge Rate of Energy Storage System in Islanded AC Microgrids

    DEFF Research Database (Denmark)

    Guan, Yajuan; Quintero, Juan Carlos Vasquez; Guerrero, Josep M.

    2016-01-01

    incidents and unintentional outages in DG units, but also aims to provide a fast transient response and an accurate output-current-sharing performance. A complete root locus analysis is given in order to achieve system stability and parameter sensitivity. Experimental results are presented to show......A coordinated secondary control approach based on an autonomous current-sharing control strategy for balancing the discharge rates of energy storage systems (ESSs) in islanded AC microgrids is proposed in this paper. The coordinated secondary controller can regulate the power outputs of distributed...... the performance of the whole system and to verify the effectiveness of the proposed controller....

  11. A mobile system for quantifying the spatial variability of the surface energy balance: design and application

    Science.gov (United States)

    Wohlfahrt, Georg; Tasser, Erich

    2015-05-01

    We present a mobile device for the quantification of the small-scale (a few square meters) spatial variability in the surface energy balance components and several auxiliary variables of short-statured (ecological research questions. The potential of the new device is demonstrated through four selected case studies, which cover the issues of net radiation heterogeneity within the footprint of eddy covariance flux measurements due to (1) land use and (2) slope and aspect of the underlying surface, (3) controls on landscape-scale variability in soil temperature and albedo and (4) the estimation of evapotranspiration based exclusively on measurements with the mobile device.

  12. Atmospheric correction of LANDSAT TM thermal band using surface energy balance

    Science.gov (United States)

    Vidal, Alain; Devaux-Ros, Claire; Moran, M. Susan

    1994-01-01

    Thermal infrared data of LANDSAT Thematic Mapper (TM) are hardly used, probably due to the difficulties met when trying to correct them for atmospheric effects. A method for correcting these data was designed, based on surface energy balance estimation of known wet and dry targets included in the TM image to be corrected. This method, only using the image itself and local meteorological data was tested and validated on various surfaces: agricultural, forest and rangeland. The root mean square error on corrected temperatures is on the order of 1C.

  13. The energy balance of wind waves and the remote sensing problem

    Science.gov (United States)

    Hasselmann, K.

    1972-01-01

    Measurements of wave growth indicate an energy balance of the wave spectrum governed primarily by input from the atmosphere, nonlinear transfer to shorter and longer waves, and advection. The pronounced spectral peak and sharp low frequency cut-off characteristic of fetch-limited spectra are explained as a self-stabilizing feature of the nonlinear wave-wave interactions. The momentum transferred from the atmosphere to the wind waves accounts for a large part of the wind drag. These findings are relevant for remote microwave sensing of the sea surface by backscatter and passive radiometry methods.

  14. Obesity therapy: altering the energy intake-and-expenditure balance sheet.

    Science.gov (United States)

    Crowley, Vivion E F; Yeo, Giles S H; O'Rahilly, Stephen

    2002-04-01

    Obesity is associated with numerous health complications, which range from non-fatal debilitating conditions such as osteoarthritis, to life-threatening chronic diseases such as coronary heart disease, diabetes and certain cancers. The psychological consequences of obesity can range from lowered self-esteem to clinical depression. Despite the high prevalence of obesity and the many advances in our understanding of how it develops, current therapies have persistently failed to achieve long-term success. This review focuses on how fat mass can be reduced by altering the balance between energy intake and expenditure.

  15. On energy balance and the structure of radiated waves in kinetics of crystalline defects

    Science.gov (United States)

    Sharma, Basant Lal

    2016-11-01

    Traveling waves, with well-known closed form expressions, in the context of the defects kinetics in crystals are excavated further with respect to their inherent structure of oscillatory components. These are associated with, so called, Frenkel-Kontorova model with a piecewise quadratic substrate potential, corresponding to the symmetric as well as asymmetric energy wells of the substrate, displacive phase transitions in bistable chains, and brittle fracture in triangular lattice strips under mode III conditions. The paper demonstrates that the power expended theorem holds so that the sum of rate of working and the rate of total energy flux into a control strip moving steadily with the defect equals the rate of energy sinking into the defect, in the sense of N.F. Mott. In the conservative case of the Frenkel-Kontorova model with asymmetric energy wells, this leads to an alternative expression for the mobility in terms of the energy flux through radiated lattice waves. An application of the same to the case of martensitic phase boundary and a crack, propagating uniformly in bistable chains and triangular lattice strips, respectively, is also provided and the energy release is expressed in terms of the radiated energy flux directly. The equivalence between the well-known expressions and their alternative is established via an elementary identity, which is stated and proved in the paper as the zero lemma. An intimate connection between the three distinct types of defects is, thus, revealed in the framework of energy balance, via a structural similarity between the corresponding variants of the 'zero' lemma containing the information about radiated energy flux. An extension to the dissipative models, in the presence of linear viscous damping, is detailed and analog of the zero lemma is proved. The analysis is relevant to the dynamics of dislocations, brittle cracks, and martensitic phase boundaries, besides possible applications to analogous physical contexts which are

  16. European energy balance research to prevent excessive weight gain among youth (ENERGY) project

    DEFF Research Database (Denmark)

    Stralen, Maartje M. van; Velde, Saskia J. te; Singh, Amika S.;

    2011-01-01

    environmental correlates of these behaviours is needed. Studies on such multilevel correlates of EBRB among schoolchildren in Europe are lacking. The ENERGY survey aims to (1) provide up-to-date prevalence rates of measured overweight, obesity, self-reported engagement in EBRBs, and objective accelerometer...

  17. Does Sport-Drink Use During Exercise Promote an Acute Positive Energy Balance?

    Science.gov (United States)

    Dragusin, Iulian B; Horswill, Craig A

    2016-10-01

    Sports drinks have been implicated in contributing to obesity and chronic diseases by providing surplus calories and excess sugars. Using existing literature we compared energy intake from sports drinks consumed during exercise with the exercise-induced calorie expenditure to determine whether sports drink use might eliminate the energy deficit and jeopardize conditions for improved metabolic fitness. We identified 11 published studies that compared sport drink consumption to placebo during exercise with a primary focused on the effect of sport drinks or total carbohydrate content on enhancing physical performance. Energy expenditure (EE) was calculated using VO2, RER, and exercise duration for the exercise protocol. Energy ingestion (EI) was determined using the carbohydrate dosing regimen administered before and during the exercise protocol. A two-tailed t test was used to test whether the energy balance (EI-EE) was different from zero (alpha level = 0.05). Sport drink consumption during aerobic exercise of sufficient duration (≥ 60 min) did not abolish the energy deficit (p drinks to enhance performance did not abolish the caloric deficit of aerobic exercise. Sports drinks can be used in accordance with research protocols that typically provide 30-60 g of carbohydrate per hour when exercising at adequate durations for moderate to high intensity and still maintain a substantive caloric deficit.

  18. What balance do countries exhibit between the central human resources: water, energy and food

    Science.gov (United States)

    Kossak, Julian; Reusser, Dominik E.; Kropp, Jürgen P.

    2013-04-01

    Sufficient water, food and energy is a precondition for human activities. The water, energy and food nexus states that to some extend, these resources can replace each another: land can be used to produce food or energy crops; water can be used as direct water supply, to produce energy or for irrigation; and energy supports water treatment and agricultural yield. We present an overview of the major components of the trade-off together with a set of indicators and data sources to assess these components. The different indicators of the trade-off are summarized and plotted in a novel way on a triangle, which we discuss in view of the resource availability of different countries. Comparing different countries in view of their balance between water, food and energy will inform the discussion about the transition towards more sustainable societies and highlighting alternative strategies for development. This is important in view of possible synergies between the different sectors and as a tool for better coordinated governance approaches.

  19. Energy utilization, nitrogen balance and microbial protein supply in cattle fed Pennisetum purpureum and condensed tannins.

    Science.gov (United States)

    Piñeiro-Vázquez, A T; Canul-Solis, J R; Alayón-Gamboa, J A; Chay-Canul, A J; Ayala-Burgos, A J; Solorio-Sánchez, F J; Aguilar-Pérez, C F; Ku-Vera, J C

    2017-02-01

    The aim of the experiment was to assess the effect of condensed tannins (CT) on feed intake, dry matter digestibility, nitrogen balance, supply of microbial protein to the small intestine and energy utilization in cattle fed a basal ration of Pennisetum purpureum grass. Five heifers (Bos taurus × Bos indicus) with an average live weight of 295 ± 19 kg were allotted to five treatments consisting of increasing levels of CT (0, 1, 2, 3 and 4% CT/kg DM) in a 5 × 5 Latin square design. Dry matter intake (DMI) was similar (p > 0.05) between treatments containing 0, 1, 2 and 3% of CT/kg DM and it was reduced (p balance, purine derivatives excretion in urine, microbial protein synthesis and efficiency of synthesis of microbial nitrogen in the rumen were not affected (p ≥ 0.05) by the increase in the levels of condensed tannins in the ration. Energy loss as CH4 was on average 2.7% of the gross energy consumed daily. Metabolizable energy intake was 49.06 MJ/day in cattle fed low-quality tropical grass with a DMI of 6.27 kg/day. It is concluded that concentrations of CT between 2 and 3% of DM of ration reduced energy loss as CH4 by 31.3% and 47.6%, respectively, without affecting intakes of dry and organic matter; however, digestibilities of dry and organic matter are negatively affected.

  20. Energy balance of five fodder cropping systems in the irrigated lowlands of Northern Italy

    Directory of Open Access Journals (Sweden)

    Cesare Tomasoni

    2011-03-01

    Full Text Available Extensification has recently become an important option in Western European agriculture, driven both by economic considerations (product surpluses together with the fact that developed countries cropping systems have been heavily relying on fossil energy and growing public concern on the possible adverse effects of intensive farming on the environment and human health. The adoption of rational fodder crop rotations, with the rediscovery of the beneficial effect of the meadow, is viewed as a possible mean to reduce the impact of farming systems in the lowlands of Northern Italy, characterised by highly intensive cropping and animal husbandry. For this reason our study examines the effects of crop rotation on the energy balance during 1985-2007 period in a long-term crop rotation trial in Northern Italy comparing five fodder crop systems, different in the degree of crop intensification and for the presence or absence of the meadow: a 1-year continuous cereal double cropping (R1; a 3-year rotation (R3; a 6-year rotation (R6; a permanent meadow (PM; and a continuous grain maize cropping (CM. Each rotation was subjected to two input treatments, defined as high (mostly used in lowlands of northern Italy and low (input reduction of ca. 30% respectively, in terms of nutrient levels, herbicide doses, and soil tillage methods. The crop rotations exerted a marked influence on the energy balance. The most efficient rotations in terms of net energy production energy efficiency have been characterized by reduced length and presence of maize and catch-crops.

  1. Distributed modeling of snow cover mass and energy balance in the Rheraya watershed (High Atlas, Morocco)

    Science.gov (United States)

    Marchane, Ahmed; Gascoin, Simon; Jarlan, Lionel; Hanich, Lahoucine

    2016-04-01

    The mountains of the High Moroccan Atlas represent an important source of water for the neighboring arid plains. Despite the importance of snow in the regional water balance, few studies were devoted to the modeling of the snow cover at the watershed scale. This type of modeling is necessary to characterize the contribution of snowmelt to water balance and understanding its sensitivity to natural and human-induced climate fluctuations. In this study, we applied a spatially-distributed model of the snowpack evolution (SnowModel, Liston & Elder 2006) on the Rheraya watershed (225 km²) in the High Atlas in order to simulate the mass and energy balance of the snow cover and the evolution of snow depth over a full season (2008-2009). The model was forced by 6 meteorological stations. The model was evaluated locally at the Oukaimeden meteorological station (3230 m asl) where snow depth is recorded continuously. To evaluate the model at the watershed scale we used the daily MODIS snow cover products and a series of 15 cloud-free optical images acquired by the FORMOSAT-2 satellite at 8-m resolution from February to June 2009. The results showed that the model is able to simulate the snow depth in the Oukaimeden station for the 2008-2009 season, and also to simulate the spatial and temporal variation of of the snow cover area in the watershed Rheraya. Based on the model output we examine the importance of the snow sublimation on the water balance at the watershed scale.

  2. Components of near-surface energy balance derived from satellite soundings – Part 1: Net available energy

    Directory of Open Access Journals (Sweden)

    K. Mallick

    2014-08-01

    Full Text Available This paper introduces a relatively simple method for recovering global fields of near-surface net available energy (the sum of the sensible and latent heat flux or the difference between the net radiation and surface heat accumulation using satellite visible and infra-red products derived from the AIRS (Atmospheric Infrared Sounder and MODIS (MOderate Resolution Imaging Spectroradiometer platforms. The method focuses on first specifying net surface radiation by considering its various shortwave and longwave components. This was then used in a surface energy balance equation in conjunction with satellite day–night surface temperature difference to derive 12 h discrete time estimates of surface, system heat capacity and heat accumulation, leading directly to retrieval for surface net available energy. Both net radiation and net available energy estimates were evaluated against ground truth data taken from 30 terrestrial tower sites affiliated to the FLUXNET network covering 7 different biome classes. This revealed a relatively good agreement between the satellite and tower data, with a pooled root mean square deviation of 98 and 72 W m−2 for net radiation and net available energy, respectively, although both quantities were underestimated by approximately 25 and 10%, respectively relative to the tower observations. Analysis of the individual shortwave and longwave components of the net radiation revealed the downwelling shortwave radiation to be the main source of this systematic underestimation.

  3. Advanced biofuels - GHG emissions and energy balances. A report to IEA bioenergy task 39

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, Don [S and T 2 Consultants Inc., Delta, British Columbia (Canada)

    2013-05-25

    In this work, a number of advanced biofuel pathways were examined with respect to their energy balances and GHG emission performance. Some of these pathways have relatively detailed public techno-economic modelling studies available on which the energy and GHG lifecycle modelling has been based. However there is a continuum in the quality of publicly available data and, for some of the pathways a significant number of assumptions had to be made in order to generate results. Some caution is therefore warranted when the results of different systems are compared. Furthermore, none of the modelling data is based on actual operating systems, as the processes being assessed are not yet in commercial operation; rather, they are each in different stages of research, development and demonstration.

  4. Role of Isospin Degree of freedom on the impact parameter dependence of balance energy

    CERN Document Server

    Sood, Dolly; Kumar, Suneel; Puri, Rajeev K

    2010-01-01

    For this study we have simulated the 28Ni58+28Ni58 and 26Fe58+26Fe58 systems at incident energies ranging from 45 MeV/nucleon to 105 MeV/nucleon by using soft equation of state. The geometry of reactions chosen are = b/bmax = 0.2, 0.4, 0.5, 0.6, and 0.7.The Px/A is becoming more positive for neutron - rich system 26Fi58 as compared to neutron-poor system 28Ni58. This point towards the higher value of balance energy for 26Fi58 system. Further study in this direction is ongoing.

  5. Lysimetric Evaluation of Simplified Surface Energy Balance Approach in the Texas High Plains

    Science.gov (United States)

    Senay, Gabriel B.; Gowda, P.H.; Howell, T.A.; Marek, T.H.

    2009-01-01

    Numerous energy balance (EB) algorithms have been developed to make use of remote sensing data to estimate evapotranspiration (ET) regionally. However, most EB models are complex to use and efforts are being made to simplify procedures mainly through the scaling of reference ET. The Simplified Surface Energy Balance (SSEB) is one such method. This approach has never been evaluated using measured ET data. In this study, the SSEB approach was applied to fourteen Landsat TM images covering a major portion of the Southern High Plains that were acquired during 2006 and 2007 cropping seasons. Performance of the SSEB was evaluated by comparing estimated ET with measured daily ET from four large monolithic lysimeters at the USDA-ARS Conservation and Production Research Laboratory, Bushland, Texas. Statistical evaluation of results indicated that the SSEB accounted for 84% of the variability in the measured ET values with a slope and intercept of 0.75 and 1.1 mm d-1, respectively. Considering the minimal amount of ancillary data required and excellent performance in predicting daily ET, the SSEB approach is a promising tool for mapping ET in the semiarid Texas High Plains and in other parts of the world with similar hydro-climatic conditions.

  6. Improving iterative surface energy balance convergence for remote sensing based flux calculation

    Science.gov (United States)

    Dhungel, Ramesh; Allen, Richard G.; Trezza, Ricardo

    2016-04-01

    A modification of the iterative procedure of the surface energy balance was purposed to expedite the convergence of Monin-Obukhov stability correction utilized by the remote sensing based flux calculation. This was demonstrated using ground-based weather stations as well as the gridded weather data (North American Regional Reanalysis) and remote sensing based (Landsat 5, 7) images. The study was conducted for different land-use classes in southern Idaho and northern California for multiple satellite overpasses. The convergence behavior of a selected Landsat pixel as well as all of the Landsat pixels within the area of interest was analyzed. Modified version needed multiple times less iteration compared to the current iterative technique. At the time of low wind speed (˜1.3 m/s), the current iterative technique was not able to find a solution of surface energy balance for all of the Landsat pixels, while the modified version was able to achieve it in a few iterations. The study will facilitate many operational evapotranspiration models to avoid the nonconvergence in low wind speeds, which helps to increase the accuracy of flux calculations.

  7. Ghrelin-Reactive Immunoglobulins in Conditions of Altered Appetite and Energy Balance

    Science.gov (United States)

    Fetissov, Sergueï O.; Lucas, Nicolas; Legrand, Romain

    2017-01-01

    Part of circulating ghrelin is bound to immunoglobulins (Ig) protecting it from degradation and preserving its functional activity. This review summarizes the data on ghrelin- and desacyl-ghrelin-reactive IgG in conditions of altered appetite and energy balance. Plasma levels and affinity kinetics of such IgG were compared in patients with obesity and anorexia nervosa (AN) and in animal models of obesity including ob/ob mice, high-fat diet-induced obese mice, and obese Zucker rats as well as in mice after chronic food restriction and activity-based anorexia and in rats with methotrexate-induced anorexia. We show that plasmatic IgG in both obese humans and animals are characterized by increased affinity for ghrelin. In contrast, patients with AN and anorectic rodents all show lower affinity of ghrelin- and desacyl-ghrelin-reactive IgG, respectively, the changes which were not observed in non-anorectic, chronically starved mice. We also show that affinity of ghrelin-reactive IgG correlate with plasma levels of ghrelin. These data point to common mechanisms underlying modifications of affinity kinetics properties of ghrelin-reactive IgG during chronic alterations of energy balance in humans and rodents and support a functional role of such autoantibodies in ghrelin-mediated regulation of appetite. PMID:28191004

  8. The greenhouse gas and energy balance of different treatment concepts for bio-waste.

    Science.gov (United States)

    Ortner, Maria E; Müller, Wolfgang; Bockreis, Anke

    2013-10-01

    The greenhouse gas (GHG) and energy performance of bio-waste treatment plants been investigated for three characteristic bio-waste treatment concepts: composting; biological drying for the production of biomass fuel fractions; and anaerobic digestion. Compared with other studies about the environmental impacts of bio-waste management, this study focused on the direct comparison of the latest process concepts and state-of-the-art emission control measures. To enable a comparison, the mass balance and products were modelled for all process concepts assuming the same bio-waste amounts and properties. In addition, the value of compost as a soil improver was included in the evaluation, using straw as a reference system. This aspect has rarely been accounted for in other studies. The study is based on data from operational facilities combined with literature data. The results show that all three concepts contribute to a reduction of GHG emissions and show a positive balance for cumulated energy demand. However, in contrast to other studies, the advantage of anaerobic digestion compared with composting is smaller as a result of accounting for the soil improving properties of compost. Still, anaerobic digestion is the environmentally superior solution. The results are intended to inform decision makers about the relevant aspects of bio-waste treatment regarding the environmental impacts of different bio-waste management strategies.

  9. Global existence for a hydrogen storage model with full energy balance

    CERN Document Server

    Bonetti, Elena; Laurençot, Philippe

    2011-01-01

    A thermo-mechanical model describing hydrogen storage by use of metal hydrides has been recently proposed in a paper by Bonetti, Fr\\'emond and Lexcellent. It describes the formation of hydrides using the phase transition approach. By virtue of the laws of continuum thermo-mechanics, the model leads to a phase transition problem in terms of three state variables: the temperature, the phase parameter representing the fraction of one solid phase, and the pressure, and is derived within a generalization of the principle of virtual powers proposed by Fr\\'emond accounting for micro-forces, responsible for the phase transition, in the whole energy balance of the system. Three coupled nonlinear partial differential equations combined with initial and boundary conditions have to be solved. The main difficulty in investigating the resulting system of partial differential equations relies on the presence of the squared time derivative of the order parameter in the energy balance equation. Here, the global existence of a...

  10. Environmental influences on energy balance-related behaviors: A dual-process view

    Directory of Open Access Journals (Sweden)

    van Mechelen Willem

    2006-05-01

    Full Text Available Abstract Background Studies on the impact of the 'obesogenic' environment have often used non-theoretical approaches. In this journal's debate and in other papers authors have argued the necessity of formulating conceptual models for differentiating the causal role of environmental influences on behavior. Discussion The present paper aims to contribute to the debate by presenting a dual-process view on the environment – behavior relationship. This view is conceptualized in the EnRG framework (Environmental Research framework for weight Gain prevention. In the framework, behavior is postulated to be the result of a simultaneous influence of conscious and unconscious processes. Environmental influences are hypothesized to influence behavior both indirectly and directly. The indirect causal mechanism reflects the mediating role of behavior-specific cognitions in the influence of the environment on behavior. A direct influence reflects the automatic, unconscious, influence of the environment on behavior. Specific personal and behavioral factors are postulated to moderate the causal path (i.e., inducing either the automatic or the cognitively mediated environment – behavior relation. In addition, the EnRG framework applies an energy balance-approach, stimulating the integrated study of determinants of diet and physical activity. Conclusion The application of a dual-process view may guide research towards causal mechanisms linking specific environmental features with energy balance-related behaviors in distinct populations. The present paper is hoped to contribute to the evolution of a paradigm that may help to disentangle the role of 'obesogenic' environmental factors.

  11. Evaluating the Potential of Variable Renewable Energy for a Balanced Isolated Grid: A Japanese Case Study

    Directory of Open Access Journals (Sweden)

    Mai Inoue

    2017-01-01

    Full Text Available There is a global push to develop renewable energy to further a low-carbon society. However, the nature of variable renewable energy (VRE sources such as wind power and solar photovoltaic (PV systems may create problems because electricity grids require a stable power supply to match demand. To evaluate the potential capacity of VREs that may be installed, we develop an optimized model that balances power supply and demand and also considers grid balancing by battery storage and load frequency control. The model was applied to a case study of an isolated grid on a remote Japanese island. When set to optimize the grid in terms of lowest cost, the model suggested that, compared with the base case, the capacity of wind power should be increased by a factor of 1.7 and 15.8 for situations without and with battery storage, respectively. Since it was always considered to be more expensive than wind power, no change in solar PV capacity was observed. These approaches resulted in a decrease in the total power generation cost of 2% and 24%, respectively, while total CO2 emissions fell by 3% and 52%, primarily driven by decreased used of the existing fossil-fueled thermal plant.

  12. Effects of acute intermittent hypoxia on energy balance and hypothalamic feeding pathways.

    Science.gov (United States)

    Moreau, J M; Ciriello, J

    2013-12-01

    This study was done to investigate the effects of acute intermittent hypoxia (IH) on metabolic factors associated with energy balance and body weight, and on hypothalamic satiety-inducing pathways. Adult male Sprague-Dawley rats were exposed to either 8h IH or normoxic control conditions. Food intake, locomotion and body weights were examined after IH. Additionally, plasma levels of leptin, adiponectin corticosterone, insulin and blood glucose were measured following exposure to IH. Furthermore, adipose tissue was removed and analyzed for leptin and adiponectin content. Finally, the hypothalamic arcuate nucleus (ARC) was assessed for alterations in protein signaling associated with satiety. IH reduced body weight, food intake and active cycle locomotion without altering adipose tissue mass. Leptin protein content was reduced while adiponectin content was elevated in adipose tissue after IH. Plasma concentration of leptin was significantly increased while adiponectin decreased after IH. No changes were found in plasma corticosterone, insulin and blood glucose. In ARC, phosphorylation of signal transducer and activator of transcription-3 and pro-opiomelanocortin (POMC) expression were elevated. In addition, POMC-expressing neurons were activated as determined by immediate early gene FRA-1/2 expression. Finally, ERK1/2 and its phosphorylation were reduced in response to IH. These data suggest that IH induces significant alterations to body energy balance through changes in the secretion of leptin which exert effects on satiety-inducing pathways within the hypothalamus.

  13. Energy Balance of the Sao Paulo State -1998 Base year 1997; Balanco energetico do Estado de Sao Paulo - 1998. Ano base 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    This energy balance of the Sao Paulo State presents the following main topics that can be outstanding: panorama of the energy matrix; supply and demand of energy by source 1983-1997; energy consumption by sector 1983/1997; economic aspects; resources and reserves energy; and balance of the transformation centers 1983/1997.

  14. Energy Balance of the Sao Paulo State -1997. Base year 1996; Balanco energetico do Estado de Sao Paulo - 1997. Ano base 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    This energy balance of the Santa Catarina State presents the following main topics that can be outstanding: panorama of the energy matrix; supply and demand of energy by source 1983-1996; energy consumption by sector 1983/1996; socio-economic aspects; resources and reserves energy; and balance of the transformation centers 1984/1996.

  15. Role of stearoyl-CoA desaturase-1 in skin integrity and whole body energy balance.

    Science.gov (United States)

    Sampath, Harini; Ntambi, James M

    2014-01-31

    The skin is the single largest organ in humans, serving as a major barrier to infection, water loss, and abrasion. The functional diversity of skin requires the synthesis of large amounts of lipids, such as triglycerides, wax esters, squalene, ceramides, free cholesterol, free fatty acids, and cholesterol and retinyl esters. Some of these lipids are used as cell membrane components, signaling molecules, and a source of energy. An important class of lipid metabolism enzymes expressed in skin is the Δ(9)-desaturases, which catalyze the synthesis in Δ(9)-monounsaturated lipids, primarily oleoyl-CoA (18:1n-9) and palmitoyl-CoA (16:1n-7), the major monounsaturated fatty acids in cutaneous lipids. Mice with a deletion of the Δ(9)-desaturase-1 isoform (SCD1) either globally (Scd1(-/-)) or specifically in the skin (skin-specific Scd1-knockout; SKO) present with marked changes in cutaneous lipids and skin integrity. Interestingly, these mice also exhibit increased whole body energy expenditure, protection against diet-induced adiposity, hepatic steatosis, and glucose intolerance. The increased energy expenditure in skin-specific Scd1-knockout (SKO) mice is a surprising phenotype, as it links cutaneous lipid homeostasis with whole body energy balance. This minireview summarizes the role of skin SCD1 in regulating skin integrity and whole body energy homeostasis and offers a discussion of potential pathways that may connect these seemingly disparate phenotypes.

  16. Balancing energy development and conservation: A method utilizing species distribution models

    Science.gov (United States)

    Jarnevich, C.S.; Laubhan, M.K.

    2011-01-01

    Alternative energy development is increasing, potentially leading to negative impacts on wildlife populations already stressed by other factors. Resource managers require a scientifically based methodology to balance energy development and species conservation, so we investigated modeling habitat suitability using Maximum Entropy to develop maps that could be used with other information to help site energy developments. We selected one species of concern, the Lesser Prairie-Chicken (LPCH; Tympanuchus pallidicinctus) found on the southern Great Plains of North America, as our case study. LPCH populations have been declining and are potentially further impacted by energy development. We used LPCH lek locations in the state of Kansas along with several environmental and anthropogenic parameters to develop models that predict the probability of lek occurrence across the landscape. The models all performed well as indicated by the high test area under the curve (AUC) scores (all >0.9). The inclusion of anthropogenic parameters in models resulted in slightly better performance based on AUC values, indicating that anthropogenic features may impact LPCH lek habitat suitability. Given the positive model results, this methodology may provide additional guidance in designing future survey protocols, as well as siting of energy development in areas of marginal or unsuitable habitat for species of concern. This technique could help to standardize and quantify the impacts various developments have upon at-risk species. ?? 2011 Springer Science+Business Media, LLC (outside the USA).

  17. Pyrolysis and gasification of meat-and-bone-meal: energy balance and GHG accounting.

    Science.gov (United States)

    Cascarosa, Esther; Boldrin, Alessio; Astrup, Thomas

    2013-11-01

    Meat-and-bone-meal (MBM) produced from animal waste has become an increasingly important residual fraction needing management. As biodegradable waste is routed away from landfills, thermo-chemical treatments of MBM are considered promising solution for the future. Pyrolysis and gasification of MBM were assessed based on data from three experimental lab and pilot-scale plants. Energy balances were established for the three technologies, providing different outcomes for energy recovery: bio-oil was the main product for the pyrolysis system, while syngas and a solid fraction of biochar were the main products in the gasification system. These products can be used - eventually after upgrading - for energy production, thereby offsetting energy production elsewhere in the system. Greenhouse gases (GHG) accounting of the technologies showed that all three options provided overall GHG savings in the order of 600-1000kg CO2-eq. per Mg of MBM treated, mainly as a consequence of avoided fossil fuel consumption in the energy sector. Local conditions influencing the environmental performance of the three systems were identified, together with critical factors to be considered during decision-making regarding MBM management.

  18. Sustainable and Balanced Energy Efficiency and Preservation in Our Built Heritage

    Directory of Open Access Journals (Sweden)

    Heidi Norrström

    2013-06-01

    Full Text Available Today, conservation work in our built cultural heritage has to be reformulated due to the new energy efficiency requirements put forward. On both a national and an international level, energy efficiency measures are considered key actions within sustainability work, answering to the global issue of climate change. What does this imply for our built heritage? Contemporary conservation is characterized by the concept of sustainability, and integrated conservation is also expected to be sustainable. It is inherent in this tradition, but how are we going to balance the historic and architectural values with the new energy requirements? A research project, Energy Efficiency in Our Cultural Heritage (EEPOCH, consisting of a multiple case study, has been carried out over three years, studying selected objects restored within the Halland Model, a project over a decade long. In EEPOCH the multiple units of analysis are energy efficiency, historic and architectural values, management, and legislation. All are applied to the selected objects. The results and conclusions drawn from the analysis show that there are actions that are possible to take and to recommend, including national inventories of historic values in the existing building stock as well as guidance for the management of historic values on a municipal level for continued sustainable development.

  19. The ANIBES Study on Energy Balance in Spain: Design, Protocol and Methodology

    Directory of Open Access Journals (Sweden)

    Emma Ruiz

    2015-02-01

    Full Text Available Energy Balance (EB is an important topic to understand how an imbalance in its main determinants (energy intake and consumption may lead to inappropriate weight gain, considered to be “dynamic” and not “static”. There are no studies to evaluate EB in Spain, and new technologies reveal themselves as key tools to solve common problems to precisely quantify energy consumption and expenditure at population level. The overall purpose of the ANIBES (“Anthropometry, Intake and Energy Balance” Study was to carry out an accurate updating of food and beverage intake, dietary habits/behaviour and anthropometric data of the Spanish population (9–75 years, n = 2009, as well as the energy expenditure and physical activity patterns. Anthropometry measurements (weight, height, body mass index, waist circumference, % body fat, % body water were obtained; diet was evaluated throughout a three-day dietary record (tablet device accompanied by a 24 h-dietary recall; physical activity was quantified by questionnaire and accelerometers were also employed. Finally, information about perception and understanding of several issues related to EB was also obtained. The ANIBES study will contribute to provide valuable useful data to inform food policy planning, food based dietary guidelines development and other health oriented actions in Spain.

  20. An experimental study of energy balance in low heat rejection diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Taymaz, I. [University of Sakarya, Adapazari (Turkey). Faculty of Engineering

    2006-03-01

    In a conventional internal combustion engine, approximately one-third of total fuel input energy is converted to useful work. Since the working gas in a practical engine cycle is not exhausted at ambient temperature, a major part of the energy is lost with the exhaust gases. In addition, another major part of energy input is rejected in the form of heat via the cooling system. If the energy normally rejected to the coolant could be recovered instead on the crankshaft as useful work, then a substantial improvement in fuel economy would result. In this study, the effect of insulated heat transfer surfaces on diesel engine energy balance system was investigated. The research engine was a four-stroke, direct injected, six cylinder, turbocharged and inter-cooled diesel engine. This engine was tested at different speeds and load conditions without coating. Then, combustion chamber surfaces, cylinder head, valves and piston crown faces were coated with ceramic materials. Ceramic layers were made of CaZrO{sub 3} and MgZrO{sub 3} and plasma coated onto base of the NiCrAl bond coat. The ceramic-coated research engine was tested at the same operation conditions as the standard (without coating) engine. The results indicate a reduction in fuel consumption and heat losses to engine cooling system of the ceramic-coated engine. (author)

  1. The annual energy balances of the Flemish district: 1990-1994; Jaarlijkse energiebalansen van het Vlaamse Gewest:1990-1994

    Energy Technology Data Exchange (ETDEWEB)

    Mortier, G.; Verhoeven, G.; Vanhoof, B.; Rensbergen, J. Van

    1996-03-01

    In function of the rational energy use and the CO2 policy, detailed energy balances are formulated for Flanders for the years 1990 to 1994. For 1994, it are estimated numbers. A global energy balance gives in a coherent way an inventory of the energy streams in physical units for a certain year and for a certain country or region. The 3 main sections of an energy balance are: primary energy consumption, transformation sector and final energy consumption. As far as the total primary energy consumption in Flanders is concerned, for 1991, 1992, 1993 and 1994 increases of respective 7.8 per cent, 11.4 per cent, 9.7 per cent, and 7.4 per cent are found regarding to 1990. Going out from the Flemish energy balance, the CO2-emissions can be calculated (final energy use). The CO2-emissions in Flanders increase in 1991, 1992, 1993 and 1994 with respective 8.0 per cent, 11.0 per cent, 10.2 per cent and 8.3 per cent regard to 1990.

  2. Permafrost and surface energy balance of a polygonal tundra site in Northern Siberia – Part 2: Winter

    Directory of Open Access Journals (Sweden)

    M. Langer

    2010-08-01

    Full Text Available Permafrost is largely determined by the surface energy balance. Its vulnerability to degradation due to climate warming depends on complex soil-atmosphere interactions. This article is the second part of a comprehensive surface energy balance study at a polygonal tundra site in Northern Siberia. It comprises two consecutive winter periods from October 2007 to May 2008 and from October 2008 to January 2009. The surface energy balance is obtained by independent measurements of the radiation budget, the sensible heat flux and the ground heat flux, whereas the latent heat flux is inferred from measurements of the atmospheric turbulence characteristics and a model approach. The measurements reveal that the long-wave radiation is the dominant factor in the surface energy balance. The radiative losses are balanced to about 60% by the ground heat flux and almost 40% by the sensible heat fluxes, whereas the contribution of the latent heat flux is found to be relatively small. The main controlling factors of the surface energy budget are the snow cover, the cloudiness and the soil temperature gradient. Significant spatial differences in the surface energy balance are observed between the tundra soils and a small pond. The heat flux released from the subsurface heat storage is by a factor of two increased at the freezing pond during the entire winter period, whereas differences in the radiation budget are only observed at the end of winter. Inter-annual differences in the surface energy balance are related to differences in snow depth, which substantially affect the temperature evolution at the investigated pond. The obtained results demonstrate the importance of the ground heat flux for the soil-atmosphere energy exchange and reveal high spatial and temporal variabilities in the subsurface heat budget during winter.

  3. CUES – A Study Site for Measuring Snowpack Energy Balance in the Sierra Nevada

    Directory of Open Access Journals (Sweden)

    Edward H. Bair

    2015-09-01

    Full Text Available Accurate measurement and modeling of the snowpack energy balance are critical to understanding the terrestrial water cycle. Most of the water resources in the western US come from snowmelt, yet statistical runoff models that rely on the historical record are becoming less reliable because of a changing climate. For physically based snow melt models that do not depend on past conditions, ground based measurements of the energy balance components are imperative for verification. For this purpose, the US Army Corps of Engineers Cold Regions Research and Engineering Laboratory (CRREL and the University of California, Santa Barbara (UCSB established the CUES snow study site (CRREL/UCSB Energy Site, http://www.snow.ucsb.edu/ at 2940 m elevation on Mammoth Mountain, California. We describe CUES, provide an overview of research, share our experience with scientific measurements, and encourage future collaborative research. Snow measurements began near the current CUES site for ski area operations in 1969. In the 1970s, researchers began taking scientific measurements. Today, CUES benefits from year round gondola access and a fiber optic internet connection. Data loggers and computers automatically record and store over 100 measurements from more than 50 instruments each minute. CUES is one of only five high altitude mountain sites in the Western US where a full suite of energy balance components are measured. In addition to measuring snow on the ground at multiple locations, extensive radiometric and meteorological measurements are recorded. Some of the more novel measurements include scans by an automated terrestrial LiDAR, passive and active microwave imaging of snow stratigraphy, microscopic imaging of snow grains, snowflake imaging with a multi-angle camera, fluxes from upward and downward looking radiometers, snow water equivalent from different types of snow pillows, snowmelt from lysimeters, and concentration of impurities in the snowpack. We

  4. Water and energy balance in a Mediterranean snowpack: the importance of evaposublimation

    Science.gov (United States)

    Herrero, Javier; Pimentel, Rafael; María José, Pérez-Palazón; María José, Polo

    2016-04-01

    In low-latitude snowpacks or those located in semiarid regions, snow dynamics becomes an essential driver of the hydrological cycle, as well as an important support for a number of ecosystem services with an influence over the economy and the ecology of the whole region. Therefore, it is crucial to understand the processes that are taking place in the snowpack and the relative importance and timing of the different mass and energy fluxes. Sierra Nevada is a linear mountain range parallel to the Mediterranean coastline of southern Spain at 37°N. It reaches up to 3479 m.a.s.l. in approximately 40 km from the sea. Despite the semiarid climatic conditions that surround the high mountain area, it presents a regular snow cover above 2500 m.a.s.l. during the winter season. Previous studies have shown at this site that this snowpack is very exposed to high insolation rates and strong winds, and, like in other low-latitude areas, the radiative and evaposublimation (combination of the sublimation of ice and the evaporation of the water drops melted on the surface of the snow) fluxes may have a significant and prominent value in the coupled balance. In this work, we study the evaposublimation fraction in the annual water and energy balance over the snowpack in Sierra Nevada. For this, we apply a one-layer mass and energy balance snow model developed in previous works, which has proven to adequately simulate the shallow snowpacks of Sierra Nevada during the year. High evaposublimation rates were simulated and subsequently measured during several field campaigns. Evaposublimation fractions were found to range from 24 to 33% of the total annual ablation at this site. This ratio is very changeable between years, like the local meteorology itself, even though there was not a direct relationship between this rate and the dry or humid nature of each particular year. In fact, it is the particular distribution of the rainfall throughout the year what defines the dynamics of the

  5. Tropical Ocean Surface Energy Balance Variability: Linking Weather to Climate Scales

    Science.gov (United States)

    Roberts, J. Brent; Clayson, Carol Anne

    2013-01-01

    Radiative and turbulent surface exchanges of heat and moisture across the atmosphere-ocean interface are fundamental components of the Earth s energy and water balance. Characterizing the spatiotemporal variability of these exchanges of heat and moisture is critical to understanding the global water and energy cycle variations, quantifying atmosphere-ocean feedbacks, and improving model predictability. These fluxes are integral components to tropical ocean-atmosphere variability; they can drive ocean mixed layer variations and modify the atmospheric boundary layer properties including moist static stability, thereby influencing larger-scale tropical dynamics. Non-parametric cluster-based classification of atmospheric and ocean surface properties has shown an ability to identify coherent weather regimes, each typically associated with similar properties and processes. Using satellite-based observational radiative and turbulent energy flux products, this study investigates the relationship between these weather states and surface energy processes within the context of tropical climate variability. Investigations of surface energy variations accompanying intraseasonal and interannual tropical variability often use composite-based analyses of the mean quantities of interest. Here, a similar compositing technique is employed, but the focus is on the distribution of the heat and moisture fluxes within their weather regimes. Are the observed changes in surface energy components dominated by changes in the frequency of the weather regimes or through changes in the associated fluxes within those regimes? It is this question that the presented work intends to address. The distribution of the surface heat and moisture fluxes is evaluated for both normal and non-normal states. By examining both phases of the climatic oscillations, the symmetry of energy and water cycle responses are considered.

  6. Acute effects of mustard, horseradish, black pepper and ginger on energy expenditure, appetite, ad libitum energy intake and energy balance in human subjects

    DEFF Research Database (Denmark)

    Gregersen, Nikolaj Ture; Belza, Anita; Jensen, M.G.

    2013-01-01

    produced DIT, which tended to be larger than that of placebo (14 %, 59 (se 3) v. 52 (se 2) kJ/h, respectively, P = 0·08). No other spice induced thermogenic effects approaching statistical significance. Subjective measures of appetite (P>0·85), ad libitum EI (P = 0·63) and energy balance (P = 0·67) also...

  7. Brazilian energy balance 2015: year 2014 - final report; Balanco energetico nacional 2015: ano base 2014 - relatorio final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-07-01

    The Balance (BEB) contains the accounting relative to energy supply and consumption, as well the conversion processes and foreign trade. It presents in a single document the historical series of these operations and information about reserves, installed capacities and Federal States data. The BEB is divided into eight chapters and ten annexes, whose contents are as follow. Chapters' content can be described as follows: Chapter 1 - Energy Analysis and Aggregated Data - presents energy highlights per source in 2014 and analyses the evolution of the domestic energy supply and its relationship with economic growth. Chapter 2 - Energy Supply and Demand by Source - has the accountancy, per primary and secondary energy sources, of the production, import, export, variation of stocks, losses, adjustments, disaggregated total per socioeconomic sector in the country. Chapter 3 - Energy Consumption by Sector - presents the final energy consumption classified by primary and secondary source for each sector of the economy. Chapter 4 - Energy Imports and Exports - presents the evolution of the data on the import and export of energy and the dependence on external energy. Chapter 5 - Balance of Transformation Centers - presents the energy balances for the energy transformation centers including their losses. Chapter 6 - Energy Resources and Reserves - has the basic concepts use in the survey of resources and reserves of primary energy sources. Chapter 7 - Energy and Socio economics - contains a comparison of energy, economic and population parameters, specific consumption, energy intensities, average prices and spending on petroleum imports. Chapter 8 - State Energy Data - presents energy data for the states by Federal Unit, main energy source production, energy installations, reserves and hydraulic potential. Relating to annexes the current structure is presented bellow: Annex I - Installed Capacity - shows the installed capacity of electricity generation, the installed

  8. Estimating the actual ET from a pecan farm using the OPEC energy-balance and Penman- Monteith methods

    Science.gov (United States)

    Debele, B.; Bawazir, S. A.

    2006-12-01

    Accurate estimation of ET from field crops/orchards is the basis for better irrigation water management. In areas like Mesilla Valley, NM, where water is scarce, it is even more important to precisely determine the crop ET. An OPEC energy balance system was run for 117 days (June 22 October 14, 2001) in a matured pecan farm at Mesilla Valley, NM. The actual evapotranspiration (ET) from pecan orchards was determined from the surface energy balance as a residual, having measured the net radiation, soil heat flux, and sensible heat components using the OPEC method. Since pecans are large trees, we have also examined the effect of including thermal energies stored in the air (Ga) and plant canopy (Gc), on top of the commonly used thermal energy stored in the soil (Gs), on surface energy balance, and hence ET. The results indicate that incorporating thermal energies stored in the air and canopy has a significant effect on total energy storage for shorter temporal resolutions, such as 30-minutes and an hour. Conversely, for longer temporal resolutions (e.g., diurnal and monthly averages), the effect of including thermal energies stored in the air and vegetation on total thermal energy storage is negligible. Our results also showed that the bulk of the total thermal energy storage (G = Gs + Ga + Gc) in the surface energy balance was stored in the soil (Gs). In addition, we have also determined the crop coefficient (Kc) of pecan by combining the actual ET obtained from the OPEC method and potential ET (ET0) calculated using weather data in the surrounding area. Our average pecan Kc values were comparable with the ones reported by other researchers using different methods. We conclude that the OPEC energy balance method can be used to calculate Kc values for pecan whereby farmers and extension agents use the calculated Kc values in combination with ET0 to determine the consumptive use of pecan trees.

  9. Essential role of UCP1 modulating the central effects of thyroid hormones on energy balance

    Science.gov (United States)

    Alvarez-Crespo, Mayte; Csikasz, Robert I.; Martínez-Sánchez, Noelia; Diéguez, Carlos; Cannon, Barbara; Nedergaard, Jan; López, Miguel

    2016-01-01

    Objective Classically, metabolic effects of thyroid hormones (THs) have been considered to be peripherally mediated, i.e. different tissues in the body respond directly to thyroid hormones with an increased metabolism. An alternative view is that the metabolic effects are centrally regulated. We have examined here the degree to which prolonged, centrally infused triiodothyronine (T3) could in itself induce total body metabolic effects and the degree to which brown adipose tissue (BAT) thermogenesis was essential for such effects, by examining uncoupling protein 1 (UCP1) KO mice. Methods Wildtype and UPC1 KO mice were centrally-treated with T3 by using minipumps. Metabolic measurements were analyzed by indirect calorimetry and expression analysis by RT-PCR or western blot. BAT morphology and histology were studied by immunohistochemistry. Results We found that central T3-treatment led to reduced levels of hypothalamic AMP-activated protein kinase (AMPK) and elevated body temperature (0.7 °C). UCP1 was essential for the T3-induced increased rate of energy expenditure, which was only observable at thermoneutrality and notably only during the active phase, for the increased body weight loss, for the increased hypothalamic levels of neuropeptide Y (NPY) and agouti-related peptide (AgRP) and for the increased food intake induced by central T3-treatment. Prolonged central T3-treatment also led to recruitment of BAT and britening/beiging (“browning”) of inguinal white adipose tissue (iWAT). Conclusions We conclude that UCP1 is essential for mediation of the central effects of thyroid hormones on energy balance, and we suggest that similar UCP1-dependent effects may underlie central energy balance effects of other agents. PMID:27069867

  10. Contrasting characteristics of the surface energy balance between the urban and rural areas of Beijing

    Science.gov (United States)

    Wang, Linlin; Gao, Zhiqiu; Miao, Shiguang; Guo, Xiaofeng; Sun, Ting; Liu, Maofeng; Li, Dan

    2015-04-01

    A direct comparison of urban and rural surface energy balances, as well as a variety of other variables including incoming shortwave/longwave radiation and aerosol optical depth, is conducted for the Beijing metropolitan area. The results indicate that, overall, the urban area receives a smaller amount of incoming shortwave radiation but a larger amount of incoming longwave radiation. However, comparisons in the aerosol optical depth and cloud fraction at the two locations suggest that neither aerosol optical depth nor cloud fraction alone can explain the difference in the incoming shortwave radiation. The urban-rural differences in the incoming longwave radiation are unlikely to be caused by the presence of more abundant greenhouse gases over the urban area, as suggested by some previous studies, given that water vapor is the most dominant greenhouse gas and precipitable water is found to be less in urban areas. The higher incoming longwave radiation observed over the urban area is mostly likely due to the higher temperatures of the ambient air. The urban area is also found to always produce higher sensible heat fluxes and lower latent heat fluxes in the growing season. Furthermore, the urban area is associated with a larger amount of available energy (the sum of sensible and latent heat fluxes) than the rural area, except in May and October when evapotranspiration in the rural area significantly exceeds that in the urban area. This study provides observational evidence of urban-rural contrasts in relevant energy-balance components that plausibly arise from urban-rural differences in atmospheric and land-surface conditions.

  11. The effect of H3+ cooling on jovian thermospheric energy and momentum balance

    Science.gov (United States)

    Ray, L. C.; Achilleos, N. A.; Miller, S.

    2014-12-01

    When the Galileo probe entered Jupiter's equatorial atmosphere, it measured thermospheric exobase temperatures of ~900 K, 700 K higher than what was expected from solar EUV heating. Therefore, there is an 'energy crisis' at Jupiter, in which a large source of equatorial heating is unaccounted for. A prime candidate to explain the high temperatures is the transport of auroral energy equatorwards from high latitudes. However, the combination of strong Coriolis forces from the rapid planetary rotation rate, coupled with ion drag from magnetosphere-ionosphere coupling, results in an 'ion drag fridge' effect (Smith et al., 2007), which acts to transport auroral energy poleward, rather than equatorward. We modify the UCL JASMIN model (Jovian Axisymmetric Simulator with Magnetosphere, Ionosphere, and Neutrals) to include the effects of auroral heating and H3+ cooling. Thus far, auroral heating and H3+ cooling were neglected in dynamical models of the coupled thermosphere-ionosphere-magnetosphere system, in order to focus on the effects of joule heating and ion drag on the jovian thermosphere. We explore how including these heating and cooling terms alters the energy and momentum balance, and subsequently meridional transport through Jupiter's thermosphere.

  12. Market integration of responsive customers : application to energy and balancing markets

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, C.; Valencia, I.; Alcazar, M. [Univ. Politecnica de Valencia, Valencia (Spain). Inst. of Energy Engineering; Gabaldon, A.; Escriva, G. [Univ. Politecnica de Cartagena, Cartagena (Spain). Dept. of Electrical Engineering

    2009-07-01

    Demand response management methods are now being adopted by many deregulated electric utilities. This article presented details of a method designed to create offers and bids for large electricity customers. The method was developed to analyze daily and monthly energy consumption rates and participation in energy and ancillary service markets in Spain. A simulation was used to analyze day-ahead, inter-daily, and balancing scenarios. Peak demand in winter and summer months was characterized. Energy consumption was analyzed for different demand packages related to air conditioning, outdoor lighting, indoor lighting, and other domestic loads. Prices for each package were calculated in order to assess demand reduction capabilities. Differences between real consumption levels and energy prices bought at real-time prices were compared. An overview of Spanish electricity market structures was provided. Results of the study showed that electricity customers may benefit from participating in demand response programs. It was concluded that lower prices obtained during periods of low electricity production outweighed the higher costs of peak electricity periods. 13 refs., 3 tabs., 9 figs.

  13. Microclimatic models. Estimation of components of the energy balance over land surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Heikinheimo, M.; Venaelaeinen, A.; Tourula, T. [Finnish Meteorological Inst., Helsinki (Finland). Air Quality Dept.

    1996-12-31

    Climates at regional scale are strongly dependent on the interaction between atmosphere and its lower boundary, the oceans and the land surface mosaic. Land surfaces influence climate through their albedo, and the aerodynamic roughness, the processes of the biosphere and many soil hydrological properties; all these factors vary considerably geographically. Land surfaces receive a certain portion of the solar irradiance depending on the cloudiness, atmospheric transparency and surface albedo. Short-wave solar irradiance is the source of the heat energy exchange at the earth`s surface and also regulates many biological processes, e.g. photosynthesis. Methods for estimating solar irradiance, atmospheric transparency and surface albedo were reviewed during the course of this project. The solar energy at earth`s surface is consumed for heating the soil and the lower atmosphere. Where moisture is available, evaporation is one of the key components of the surface energy balance, because the conversion of liquid water into water vapour consumes heat. The evaporation process was studied by carrying out field experiments and testing parameterisation for a cultivated agricultural surface and for lakes. The micrometeorological study over lakes was carried out as part of the international `Northern Hemisphere Climatic Processes Experiment` (NOPEX/BAHC) in Sweden. These studies have been aimed at a better understanding of the energy exchange processes of the earth`s surface-atmosphere boundary for a more accurate and realistic parameterisation of the land surface in atmospheric models

  14. Alterations in energy balance from an exercise intervention with ad libitum food intake.

    Science.gov (United States)

    Melzer, Katarina; Renaud, Anne; Zurbuchen, Stefanie; Tschopp, Céline; Lehmann, Jan; Malatesta, Davide; Ruch, Nicole; Schutz, Yves; Kayser, Bengt; Mäder, Urs

    2016-01-01

    Better understanding is needed regarding the effects of exercise alone, without any imposed dietary regimens, as a single tool for body-weight regulation. Thus, we evaluated the effects of an 8-week increase in activity energy expenditure (AEE) on ad libitum energy intake (EI), body mass and composition in healthy participants with baseline physical activity levels (PAL) in line with international recommendations. Forty-six male adults (BMI = 19·7-29·3 kg/m(2)) participated in an intervention group, and ten (BMI = 21·0-28·4 kg/m(2)) in a control group. Anthropometric measures, cardiorespiratory fitness, EI, AEE and exercise intensity were recorded at baseline and during the 1st, 5th and 8th intervention weeks, and movement was recorded throughout. Body composition was measured at the beginning and at the end of the study, and resting energy expenditure was measured after the study. The intervention group increased PAL from 1·74 (se 0·03) to 1·93 (se 0·03) (P energy balance. Replication using a longer period (and/or more intense increase in PAL) is needed to investigate if and at what body composition the increase in AEE is met by an equivalent increase in EI.

  15. Nutrients and Energy Balance Analysis for a Conceptual Model of a Three Loops off Grid, Aquaponics

    Directory of Open Access Journals (Sweden)

    Uri Yogev

    2016-12-01

    Full Text Available Food security, specifically in water scarce regions, is an increasing local and global challenge. Finding new ways to increase agricultural production in a sustainable manner is required. The current study suggests a conceptual model to integrate established recirculating aquaculture practices into a near-zero discharge aquaponic system that efficiently utilizes water, excreted nutrients and organic matter for energy. The suggested model allows to significantly extend the planted area and recover energy in the form of biogas to operate the system off-grid. A mass balance model of nitrogen, carbon and energy was established and solved, based on data from the literature. Results demonstrate that a fish standing stock of about 700 kg would produce 3.4 tons of fish annually and enough nutrients to grow about 35 tons of tomatoes per year (chosen as a model plant and recover sufficient energy (70 kWh/day to run the system on biogas and use less water. If proven successful, this approach may play a major role in sustainably enhancing food security in rural and water scarce regions.

  16. Deriving star formation histories from photometry using energy balance spectral energy distribution modelling

    CERN Document Server

    Smith, Daniel J B

    2015-01-01

    Panchromatic spectral energy distribution (SED) fitting is a critical tool for determining the physical properties of distant galaxies, such as their stellar mass and star formation rate. One widely used method is the publicly available MAGPHYS code. We build on our previous analysis (Hayward & Smith 2015) by presenting some modifications which enable MAGPHYS to automatically estimate galaxy star formation histories (SFHs), including uncertainties, based on ultra-violet to far-infrared photometry. We use state-of-the art synthetic photometry derived by performing three-dimensional dust radiative transfer on hydrodynamic simulations of isolated disc and merging galaxies to test how well the modified MAGPHYS is able to recover SFHs under idealised conditions, where the true SFH is known. We find that while the SFH of the model with the best fit to the synthetic photometry is a poor representation of the true SFH (showing large variations with the line-of-sight to the galaxy and spurious bursts of star forma...

  17. Multiple time scale evaluation of the energy balance during the maize growing season,and a new reason for energy imbalance

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Energy imbalance is a common problem associated with the measurement of surface energy using the eddy covariance method.In the evaluation of the energy balance,people usually pay more attention to the statistical result that the effective energy(the sum of sensible and latent heat) is systematically lower than the available energy(the difference of net radiation and ground heat flux).However,little attention has been paid to the existence of the reversed situation when the effective energy is larger than the available energy or their contribution to the overall energy closure rate.In this paper,based on the analysis of the energy balance on multiple time scales across the maize growth season,we conclude that the non-synchronization of energy components is the main reason for the existence of the reversed case.By shifting the phase of the effective energy components half an hour ahead,the rates of energy closure over all time scales are improved and dramatically reduce the number of the half-hourly samples when the energy ratio exceeds 1 or is below 0.5.According to the characteristics of the energy distribution and transformation over multiple time scales,latent heat is always the main type of energy cost,and the residual of the energy balance increases with the growth of the maize plant surpassing the sensible heat for seventy days.It is suggested that the heat storage and photosynthetic energy play an important role in the energy balance during the growing period of maize.

  18. Surface layer scintillometry for estimating the sensible heat flux component of the surface energy balance

    Directory of Open Access Journals (Sweden)

    M. J. Savage

    2010-01-01

    Full Text Available The relatively recently developed scintillometry method, with a focus on the dual-beam surface layer scintillometer (SLS, allows boundary layer atmospheric turbulence, surface sensible heat and momentum flux to be estimated in real-time. Much of the previous research using the scintillometer method has involved the large aperture scintillometer method, with only a few studies using the SLS method. The SLS method has been mainly used by agrometeorologists, hydrologists and micrometeorologists for atmospheric stability and surface energy balance studies to obtain estimates of sensible heat from which evaporation estimates representing areas of one hectare or larger are possible. Other applications include the use of the SLS method in obtaining crucial input parameters for atmospheric dispersion and turbulence models. The SLS method relies upon optical scintillation of a horizontal laser beam between transmitter and receiver for a separation distance typically between 50 and 250 m caused by refractive index inhomogeneities in the atmosphere that arise from turbulence fluctuations in air temperature and to a much lesser extent the fluctuations in water vapour pressure. Measurements of SLS beam transmission allow turbulence of the atmosphere to be determined, from which sub-hourly, real-time and in situ path-weighted fluxes of sensible heat and momentum may be calculated by application of the Monin-Obukhov similarity theory. Unlike the eddy covariance (EC method for which corrections for flow distortion and coordinate rotation are applied, no corrections to the SLS measurements, apart from a correction for water vapour pressure, are applied. Also, path-weighted SLS estimates over the propagation path are obtained. The SLS method also offers high temporal measurement resolution and usually greater spatial coverage compared to EC, Bowen ratio energy balance, surface renewal and other sensible heat measurement methods. Applying the shortened surface

  19. Macroscopic Thermal Energy Balance on Montane Valley Aquifers and Groundwater Recharge Source Identification

    Science.gov (United States)

    Trask, J. C.; Fogg, G. E.

    2010-12-01

    Several recent publications have highlighted the need to improve definition of groundwater flow patterns in montane regions, presenting case studies with several field investigative approaches. Determination of the depth of upland bedrock groundwater circulation and identification of valley aquifer recharge sources in montane areas is needed for improved characterization of montane groundwater flow patterns and for aquifer source protection planning. In most upland bedrock regions, wells and boreholes are scarce, adding to the challenges inherent to investigating groundwater flow in fractured rock systems. Approaches using natural environmental tracers have previously been shown to be effective in quantifying subsurface recharge into valley aquifers from groundwater flow within adjoining mountain-front and mountain-block areas. Thermal tracing of montane groundwater flow is easy and inexpensive relative to other environmental tracer and geophysical techniques, and can complement other approaches (e.g. Manning and Solomon, 2005). We present a heat flow tracer approach to identification of montane valley aquifer recharge sources. A novel application of a macroscopic thermal energy balance is introduced and used in recharge source analysis for two mountain-front bounding basin-fill aquifers located in the Sierra Nevada, USA. We show that robust upper and lower bounds on total heat flow and sources of recharge into montane valley aquifers may be determined without numerical modeling by using a macroscopic thermal energy balance. Several factors tend to enhance focusing of geothermal conductive heat flow from depth toward montane valley margins. Analytic bracketing techniques, applicable to domains with irregular boundary geometry and non-uniform thermal boundary conditions, are used together with thermal data to obtain quantitative bounds on conductive heat flow across aquifer domain boundaries. Thermal data required include: (i) a rough estimate of regional geothermal

  20. The urban energy balance of a lightweight low-rise neighborhood in Andacollo, Chile

    Science.gov (United States)

    Crawford, Ben; Krayenhoff, E. Scott; Cordy, Paul

    2016-10-01

    Worldwide, the majority of rapidly growing neighborhoods are found in the Global South. They often exhibit different building construction and development patterns than the Global North, and urban climate research in many such neighborhoods has to date been sparse. This study presents local-scale observations of net radiation (Q * ) and sensible heat flux (Q H ) from a lightweight low-rise neighborhood in the desert climate of Andacollo, Chile, and compares observations with results from a process-based urban energy-balance model (TUF3D) and a local-scale empirical model (LUMPS) for a 14-day period in autumn 2009. This is a unique neighborhood-climate combination in the urban energy-balance literature, and results show good agreement between observations and models for Q * and Q H . The unmeasured latent heat flux (Q E ) is modeled with an updated version of TUF3D and two versions of LUMPS (a forward and inverse application). Both LUMPS implementations predict slightly higher Q E than TUF3D, which may indicate a bias in LUMPS parameters towards mid-latitude, non-desert climates. Overall, the energy balance is dominated by sensible and storage heat fluxes with mean daytime Bowen ratios of 2.57 (observed Q H /LUMPS Q E )-3.46 (TUF3D). Storage heat flux (ΔQ S ) is modeled with TUF3D, the empirical objective hysteresis model (OHM), and the inverse LUMPS implementation. Agreement between models is generally good; the OHM-predicted diurnal cycle deviates somewhat relative to the other two models, likely because OHM coefficients are not specified for the roof and wall construction materials found in this neighborhood. New facet-scale and local-scale OHM coefficients are developed based on modeled ΔQ S and observed Q * . Coefficients in the empirical models OHM and LUMPS are derived from observations in primarily non-desert climates in European/North American neighborhoods and must be updated as measurements in lightweight low-rise (and other) neighborhoods in various

  1. Satellite remote sensing of surface energy balance: Success, failures, and unresolved issues in FIFE

    Science.gov (United States)

    Hall, Forrest G.; Huemmrich, Karl F.; Goetz, Scott J.; Sellers, Piers J.; Nickeson, Jaime E.

    1992-11-01

    The FIFE staff science group, consisting of the authors, developed and evaluated process models relating surface energy and mass flux, that is, surface rates, to boundary layer and surface biophysical characteristics, that is, surface states. In addition, we developed and evaluated remote sensing algorithms for inferring surface state characteristics. In this paper we report the results of our efforts. We also look in detail at the sensor and satellite platform requirements (spatial resolution and orbital requirements) as driven by surface energy balance dynamics and spatial variability. We examine also the scale invariance of the process models and remote sensing algorithms, that is, to what degree do the remotely sensed parameters and energy balance relations translate from the patch level where they were developed to the mesoscale level where they are required? Finally, we examine the atmospheric correction and calibration issues involved in extending the remotely sensed observations within a season and between years. From these investigations we conclude that (1) existing formulations for the radiation balance and latent heat components of the surface energy balance equation are valid at the patch level. (2) Many of the surface physiological characteristics that parameterize these formulations can be estimated using satellite remote sensing at both local and regional scales; a few important ones cannot. (3) The mathematical structures relating radiation and surface energy flux to remote sensing parameters are, for the most part, scale invariant over the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) study area. The conditions for scale invariance are derived. (4) The precision of satellite remote sensing estimates of surface reflectance, calibrated and corrected for atmospheric effects, is no worse than about 1% absolute. The errors may actually be smaller, but an upper bound of 1% results from sampling variance

  2. Mammary gene expression profiles during an intramammary challenge reveal potential mechanisms linking negative energy balance with impaired immune response

    DEFF Research Database (Denmark)

    Moyes, Kasey; Drackley, J K; Morin, D E;

    2010-01-01

    Our objective was to compare mammary tissue gene expression profiles during a Streptococcus uberis (S. uberis) mastitis challenge between lactating cows subjected to dietary-induced negative energy balance (NEB; n = 5) and cows fed ad libitum to maintain positive energy balance (PEB; n = 5......) in order to better understand the mechanisms associated with NEB and risk of mastitis during the transition period. The NEB cows were feed-restricted to 60% of calculated net energy for lactation requirements for 7 d, and cows assigned to PEB were fed the same diet for ad libitum intake. Five days after...... feed restriction, one rear mammary quarter of each cow was inoculated with 5,000 cfu of S. uberis (O140J). At 20 h post-inoculation, S. uberis-infected mammary quarters from all cows were biopsied for RNA extraction. Energy balance (NEB vs. PEB) resulted in 287 differentially expressed genes (DEG; FDR...

  3. Changes in self-reported energy balance behaviours and body mass index during a mass media campaign

    NARCIS (Netherlands)

    Verheijden, M.W.; Dommelen, P. van; Empelen, P. van; Crone, M.R.; Werkman, A.M.; Kesteren, N.M.C. van

    2012-01-01

    Background: Prevention of (serious) overweight can be achieved by means of small behaviour changes in physical activity and/or diet. Objective: To evaluate a mass media campaign promoting energy balance behaviours in a Dutch population. Effects were examined for body mass index (BMI) and five energy

  4. New considerations on the mass and energy balances in one-dimensional two-phase flow at steady state

    Energy Technology Data Exchange (ETDEWEB)

    Collado, F.J. [Zaragoza Univ. (Spain). Dept. de Ingenieria Mecanica; Munoz, M. [Zaragoza Univ. (Spain). Dept. de Ingenieria Mecanica

    1997-08-01

    A new equation to be added to the classical mass balance expressions for two-phase flow is presented. It is based on the definition of new differential control volumes of variable length which are proportional to the gas velocity in a compressible flow. The new equation is equivalent to the gas-solids velocity ratio being constant throughout the duct, and it is used to derive a new expression of the energy balance for a two-phase, non-reacting flow. Through this energy balance, new correlations for the pressure drop in pneumatic conveying lines are obtained, showing an excellent agreement with experimental data from the high-pressure research facility of the Institute of Gas Technology, Chicago, IL. Finally, a more general equation, which is also valid for the mass balance of reacting flows, is supplied. (orig.)

  5. Cloud effects on the surface energy and mass balance of Brewster Glacier, New Zealand

    Directory of Open Access Journals (Sweden)

    J. P. Conway

    2015-02-01

    Full Text Available A thorough understanding of the influence of clouds on glacier surface energy balance (SEB and surface mass balance (SMB is critical for forward and backward modelling of glacier–climate interactions. A validated 22 month time series of SEB/SMB was constructed for the ablation zone of the Brewster Glacier, using high quality radiation data to carefully evaluate SEB terms and define clear-sky and overcast conditions. A fundamental change in glacier SEB in cloudy conditions was driven by increased effective sky emissivity and surface vapour pressure, rather than the minimal change in air temperature and wind speed. During overcast conditions, positive net longwave radiation and latent heat fluxes allowed melt to be maintained through a much greater length of time compared to clear-sky conditions, and led to similar melt in each sky condition. The sensitivity of SMB to changes in air temperature was greatly enhanced in overcast compared to clear-sky conditions due to more frequent melt and the occurrence of precipitation, which enabled a strong accumulation–albedo feedback. During the spring and autumn seasons, the sensitivity during overcast conditions was strongest. There is a need to include the effects of atmospheric moisture (vapour, cloud and precipitation on melt processes when modelling glacier–climate interactions.

  6. Beam-energy dependence of charge balance functions from Au + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider

    Science.gov (United States)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandin, A. V.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, H. F.; Cheng, J.; Cherney, M.; Christie, W.; Codrington, M. J. M.; Contin, G.; Crawford, H. J.; Cui, X.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, X.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Klein, S. R.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, Z. M.; Li, X.; Li, W.; Li, Y.; Li, X.; Li, C.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, R. M.; Ma, Y. G.; Magdy, N.; Mahapatra, D. P.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solanki, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B. J.; Sun, X. M.; Sun, Z.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Takahashi, J.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A. N.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, H.; Wang, F.; Wang, G.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, N.; Xu, Z.; Xu, H.; Xu, Y.; Xu, Q. H.; Yan, W.; Yang, Y.; Yang, C.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, Z. P.; Zhang, J. B.; Zhang, J. L.; Zhang, Y.; Zhang, S.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, Y. H.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2016-08-01

    Balance functions have been measured in terms of relative pseudorapidity (Δ η ) for charged particle pairs at the BNL Relativistic Heavy Ion Collider from Au + Au collisions at √{sNN}=7.7 GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at √{sNN}=2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). The narrowing of the balance function in central collisions at √{sNN}=7.7 GeV implies that a QGP is still being created at this relatively low energy.

  7. Energy Balance of the Santa Catarina State - Series 1980 -1996; Balanco energetico do Estado de Santa Catarina - Serie 1980-1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    This energy balance of the Santa Catarina State presents the following main topics that can be outstanding: economic aspects; supply and demand of energy by source 1980-1996; energy consumption by sector 1980/1996; energy interchange; and balance of the transformation centers 1980/1996.

  8. Rural energy balance of Colombia and its socioeconomic context 1981. Balance energetico rural de Colombia y su contexto socioeconomico 1981

    Energy Technology Data Exchange (ETDEWEB)

    Torres, J.E.

    1982-11-01

    This report discusses the methodology used and results obtained from a two-year study of the energy behavior of family and production units in rural Colombia. It gives a brief outline of a theoretical discussion of methodology and then an analysis of the use of energy in a sociocultural, economic, and technological context in rural areas. The methodology used to select the sample of family and productive units is given as is the criteria in the design of the questionnaire. Then the results are given for the study of 2,018 homes, extrapolated for six different energy regions. Energy consumption for agricultural and agroindustrial activities is given for eleven cultivations, including coffee. Rural industry is scarce, mostly the production of mud bricks and tiles. The study confirms the importance of petroleum derivatives to agriculture in Colombia. All the above information is recapitulated in a countrywide conclusion.

  9. Role of the endocannabinoid system in energy balance regulation and obesity.

    Science.gov (United States)

    Cota, Daniela

    2008-01-01

    The endogenous cannabinoid system (ECS) is a neuromodulatory system recently recognized to have a role in the regulation of various aspects of eating behavior and energy balance through central and peripheral mechanisms. In the central nervous system, cannabinoid type 1 receptors and their endogenous ligands, the endocannabinoids, are involved in modulating food intake and motivation to consume palatable food. Moreover, the ECS is present in peripheral organs, such as liver, white adipose tissue, muscle, and pancreas, where it seems to be involved in the regulation of lipid and glucose homeostasis. Dysregulation of the ECS has been associated with the development of obesity and its sequelae, such as dyslipidemia and diabetes. Conversely, recent clinical trials have shown that cannabinoid type 1 receptor blockade may ameliorate these metabolic abnormalities. Although further investigation is needed to better define the actual mechanisms of action, pharmacologic approaches targeting the ECS may provide a novel, effective option for the management of obesity, type 2 diabetes and cardiovascular disease.

  10. Identification of brown fat and mechanisms for energy balance in the marsupial, Sminthopsis crassicaudata.

    Science.gov (United States)

    Hope, P J; Pyle, D; Daniels, C B; Chapman, I; Horowitz, M; Morley, J E; Trayhurn, P; Kumaratilake, J; Wittert, G

    1997-07-01

    The presence of brown adipose tissue (BAT) in marsupials is controversial because attempts to identify mitochondrial uncoupling protein (UCP) have been unsuccessful. Sminthopsis crassicaudata is a small nocturnal marsupial with an interscapular pad of adipose tissue. Electron microscopy revealed this tissue to have characteristics typical of BAT. GDP binding and UCP detection by immunoblot confirmed BAT. Expression of UCP was increased by cold exposure. When animals were placed from 28 to 15 degrees C, body temperature (Tb) decreased by 1.7 degrees C within 30 min and a further 1.0 degree C by 90 min (P consumption (P energy balance and body composition without the need for an increase in metabolic rate or food consumption and without the need for torpor.

  11. Energy balance of a sparse coniferous high-latitude forest under winter conditions

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Batchvarova, E.; Bruin, H.A.R. de

    2001-01-01

    and night were about equally long. At low solar elevation angles the forest shades most of the snow surface. Therefore an important part of the radiation never reaches the snow surface but is absorbed by the forest. The sensible heat flux above the forest was fairly large, reaching more than 100 W m(-2......). The measurements of sensible heat flux within and above the forest revealed that the sensible heat flux from the snow surface is negligible and the sensible heat flux above the forest stems from warming of the trees. A simple model for the surface energy balance of a sparse forest is presented. The model treats......Measurements carried out in Northern Finland on radiation and turbulent fluxes over a sparse, sub-arctic boreal forest with snow covered ground were analysed. The measurements represent late winter conditions characterised by low solar elevation angles. During the experiment (12-24 March 1997) day...

  12. Climate change from the perspective of the surface energy balance and global hydrologic cycle

    Science.gov (United States)

    Ramaswamy, V.; Ming, Y.; Schwarzkopf, M. D.

    2015-12-01

    Major changes have occurred in the radiative drive of the surface since preindustrial times owing to both changes in the emissions of greenhouse gases and aerosols. These are to be contrasted with the drive at the top-of-the-atmosphere. Using global climate models and multiple observations of the surface fluxes from various platforms, we discuss how the energy balance has evolved with time and the manner in which this has affected the hydrologic cycle, including an account of the critical uncertainties. We make use of the simulations performed with global climate models and used in the IPCC assessments to diagnose the factors that are principally responsible for the changes, the contrasting atmospheric mechanisms exerted by greenhouse gases and aerosols, and the relative roles of the atmospheric constituents.

  13. Estimating Evapotranspiration from an Improved Two-Source Energy Balance Model Using ASTER Satellite Imagery

    Directory of Open Access Journals (Sweden)

    Qifeng Zhuang

    2015-11-01

    Full Text Available Reliably estimating the turbulent fluxes of latent and sensible heat at the Earth’s surface by remote sensing is important for research on the terrestrial hydrological cycle. This paper presents a practical approach for mapping surface energy fluxes using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER images from an improved two-source energy balance (TSEB model. The original TSEB approach may overestimate latent heat flux under vegetative stress conditions, as has also been reported in recent research. We replaced the Priestley-Taylor equation used in the original TSEB model with one that uses plant moisture and temperature constraints based on the PT-JPL model to obtain a more accurate canopy latent heat flux for model solving. The collected ASTER data and field observations employed in this study are over corn fields in arid regions of the Heihe Watershed Allied Telemetry Experimental Research (HiWATER area, China. The results were validated by measurements from eddy covariance (EC systems, and the surface energy flux estimates of the improved TSEB model are similar to the ground truth. A comparison of the results from the original and improved TSEB models indicates that the improved method more accurately estimates the sensible and latent heat fluxes, generating more precise daily evapotranspiration (ET estimate under vegetative stress conditions.

  14. ENERGY BALANCE AND CO2 EXCHANGE BEHAVIOUR IN SUB-TROPICAL YOUNG PINE (Pinus roxburghii PLANTATION

    Directory of Open Access Journals (Sweden)

    B. K. Bhattacharya

    2012-08-01

    Full Text Available A study was conducted to understand the seasonal and annual energy balance behaviour of young and growing sub-tropical chir pine (Pinus roxburghii plantation of eight years age in the Doon valley, India and its coupling with CO2 exchange. The seasonal cycle of dekadal daytime latent heat fluxes mostly followed net radiation cycle with two minima and range between 50–200 Wm-2 but differed from the latter during the period when soil wetness and cloudiness were not coupled. Dekadal evaporative fraction closely followed the seasonal dryness-wetness cycle thus minimizing the effect of wind on energy partitioning as compared to diurnal variation. Daytime latent heat fluxes were found to have linear relationship with canopy net assimilation rate (Y = 0.023X + 0.171, R2 = 0.80 though nonlinearity exists between canopy latent heat flux and hourly net CO2 assimilation rate . Night-time plant respiration was found to have linear relationship (Y = 0.088 + 1.736, R2 = 0.72 with night-time average vapour pressure deficit (VPD. Daily average soil respiration was found to be non-linearly correlated to average soil temperatures (Y = -0.034X2 + 1.676X – 5.382, R2 = 0.63 The coupled use of empirical models, seasonal energy fluxes and associated parameters would be useful to annual water and carbon accounting in subtropical pine ecosystem of India in the absence high-response eddy covariance tower.

  15. Building Envelope Over-Cladding: Impact on Energy Balance and Microclimate

    Directory of Open Access Journals (Sweden)

    David Dernie

    2015-06-01

    Full Text Available A considerable part of recent EU policies is currently addressed at developing effective measures to support the transition towards a low carbon society according to the principles and goals of Roadmap to 2050. In this general framework the links between the development of low-emission strategies and climate-resilient approaches to buildings play a key role. As most part of the existing building stock was built before the 1980s, retrofit and renovation actions are widely investigated. Despite progress in this field, relatively little attention has been given to the connections between the achievable energy savings and the energy investment needed to pursue the renovation process and to how technological choices can impact on the energy balance according to a multi-criteria perspective. The paper will explore how different technologies and design solutions to building envelopes cladding contribute to the reduction of the heat gains in urban environments and how appropriate adaptive strategies can further mitigate against accelerated greenhouse emissions. It will discuss the relationship between individual building performance and consequent effect on external environment. The effects of technological and material choices are evaluated for some design scenarios and conditions in order to develop an indicative impact mode.

  16. An Energy-Efficient, Load Balanced Distributed Clustering and Routing Protocol for Large Scale WSNs

    Directory of Open Access Journals (Sweden)

    Yousef Matinfard

    2013-06-01

    Full Text Available A wireless network consisting of a large number of small sensors with low-power transceivers can be an effective tool for gathering data in a variety of environments. These sensor nodes have some constraints due to limited energy, storage capacity and computing power. The energy consumed to route data from the sensor node to its destination raises as a critical issue in designing wireless sensor network routing protocols. In order to prolong the lifetime of wireless sensor networks, this study presents a multi-hop routing protocol with distributed clustering (ELDRL. First, in order to overcome the defect that the clusters distribute unevenly, ELDRL selects nodes as a cluster-head with regard to neighbor cluster-heads. Second, it partitions the network into different layers of clusters. Cluster heads in each layer cooperates with the adjacent layer to transmit sensor’s data to the base station. ELDRL spreads the workload across the sensor network, load balancing reduces hot spots in the sensor network and increases the energy lifetime of the sensor network. Moreover, the protocol not only increases the scalability but also decreases the traffic of WSN. Simulation results show that the scheme is more efficient compared with LEACH.

  17. Temporal Patterns of Energy Balance for a Brazilian Tropical Savanna under Contrasting Seasonal Conditions

    Directory of Open Access Journals (Sweden)

    Thiago R. Rodrigues

    2013-01-01

    Full Text Available The savanna of Central Brazil (locally known as cerrado has a long history of land cover change due to human activity. These changes have led to the degradation of cerrado forests and woodlands, leading to the expansion of grass-dominated cerrados and pastures. Thus, the aim of this study was to evaluate the temporal variation in energy flux in areas of degraded, grass-dominated cerrado (locally known as campo sujo in Central Brazil. The amount of Rn partitioned into H declined as monthly rainfall increased and reached a level of approximately 30% during the wet season, while the amount of Rn partitioned into Le increased as monthly rainfall increased and reached a level of approximately 60% during the wet season. As a result, H was significantly higher than Le during the dry season, resulting in a Bowen ratio (β = H/Le of 3-5, while Le was higher than H during the wet season, resulting in a β≈1. These data indicate that the energy partitioning of grass-dominated cerrado is relatively more sensitive to water availability than cerrado woodlands and forests, and have important implications for local and regional energy balance.

  18. Starch levels on performance, milk composition and energy balance of lactating dairy cows.

    Science.gov (United States)

    Carmo, Carolina Almeida; Batistel, Fernanda; de Souza, Jonas; Martinez, Junio Cesar; Correa, Paulo; Pedroso, Alexandre Mendonça; Santos, Flávio Augusto Portela

    2015-01-01

    The objective of this experiment was to evaluate the effects of starch levels in diets with the replacement of citrus pulp for corn on milk yield, milk composition, and energy balance of lactating dairy cows. Twenty-eight multiparous Holstein cows were used in seven 4 × 4 Latin squares conducted concurrently, and each experimental period consisted of 20 days (16 days for adaptation and 4 days for sampling). The experimental treatments comprised four starch levels: 15, 20, 25, and 30% in the diet. The dry matter intake increased linearly with increasing starch levels. The milk yield and 3.5% fat-corrected milk yield showed quadratic response to increasing starch levels. The milk protein content and milk total solids content responded linearly to increasing starch levels. The feed efficiency, milk lactose content, milk urea nitrogen, plasma urea nitrogen, and plasma glucose concentration were not affected by starch levels. The estimated net energy for lactation (NEL) intake increased linearly as the starch level was raised. Although the milk NEL output per kilogram of milk was not affected by starch, the milk NEL output daily responded quadratically to starch levels. In addition, the NEL in body weight gain also responded quadratically to increasing starch levels. The efficiency of energy use for milk yield and the NEL efficiency for production also responded quadratically to increasing starch levels. Diets for mid-lactating dairy cows producing around 30 kg/day of milk should be formulated to provide around 25% starch to optimize performance.

  19. Balancing Power Output and Structural Fatigue of Wave Energy Converters by Means of Control Strategies

    Directory of Open Access Journals (Sweden)

    Francesco Ferri

    2014-04-01

    Full Text Available In order to reduce the cost of electricity produced by wave energy converters (WECs, the benefit of selling electricity as well as the investment costs of the structure has to be considered. This paper presents a methodology for assessing the control strategy for a WEC with respect to both energy output and structural fatigue loads. Different active and passive control strategies are implemented (proportional (P controller, proportional-integral (PI controller, proportional-integral-derivative with memory compensation (PID controller, model predictive control (MPC and maximum energy controller (MEC, and load time-series resulting from numerical simulations are used to design structural parts based on fatigue analysis using rain-flow counting, Stress-Number (SN curves and Miner’s rule. The objective of the methodology is to obtain a cost-effective WEC with a more comprehensive analysis of a WEC based on a combination of well known control strategies and standardised fatigue methods. The presented method is then applied to a particular case study, the Wavestar WEC, for a specific location in the North Sea. Results, which are based on numerical simulations, show the importance of balancing the gained power against structural fatigue. Based on a simple cost model, the PI controller is shown as a viable solution.

  20. Balancing Power Absorption and Fatigue Loads in Irregular Waves for an Oscillating Surge Wave Energy Converter

    Energy Technology Data Exchange (ETDEWEB)

    Tom, Nathan M.; Yu, Yi-Hsiang; Wright, Alan D.; Lawson, Michael

    2016-06-24

    The aim of this paper is to describe how to control the power-to-load ratio of a novel wave energy converter (WEC) in irregular waves. The novel WEC that is being developed at the National Renewable Energy Laboratory combines an oscillating surge wave energy converter (OSWEC) with control surfaces as part of the structure; however, this work only considers one fixed geometric configuration. This work extends the optimal control problem so as to not solely maximize the time-averaged power, but to also consider the power-take-off (PTO) torque and foundation forces that arise because of WEC motion. The objective function of the controller will include competing terms that force the controller to balance power capture with structural loading. Separate penalty weights were placed on the surge-foundation force and PTO torque magnitude, which allows the controller to be tuned to emphasize either power absorption or load shedding. Results of this study found that, with proper selection of penalty weights, gains in time-averaged power would exceed the gains in structural loading while minimizing the reactive power requirement.

  1. Crop Management Effects on the Energy and Carbon Balances of Maize Stover-Based Ethanol Production

    Directory of Open Access Journals (Sweden)

    Prem Woli

    2014-12-01

    Full Text Available This study was conducted to identify the crop management options—the combinations of various cultivars, irrigation amounts, planting dates, and soils—that would maximize the energy sustainability and eco-friendliness of maize (Zea mays L. stover-based ethanol production systems in the Mississippi Delta. Stover yields simulated with CERES-Maize were used to compute net energy value (NEV and carbon credit balance (CCB, the indicators of sustainability and eco-friendliness of ethanol production, respectively, for various scenarios. As the results showed, deeper soils with higher water holding capacities had larger NEV and CCB values. Both NEV and CCB had sigmoid relationships with irrigation amount and planting date and could be maximized by planting the crop during the optimum planting window. Stover yield had positive effects on NEV and CCB, whereas travel distance had negative. The influence of stover yield was larger than that of travel distance, indicating that increasing feedstock yields should be emphasized over reducing travel distance. The NEV and CCB values indicated that stover-based ethanol production in the Mississippi Delta is sustainable and environmentally friendly. The study demonstrated that the energy sustainability and eco-friendliness of maize stover-based ethanol production could be increased with alternative crop management options.

  2. Quantification of pathways of glucose utilization and balance of energy metabolism of rabbit reticulocytes.

    Science.gov (United States)

    Siems, W; Müller, M; Dumdey, R; Holzhütter, H G; Rathmann, J; Rapoport, S M

    1982-06-01

    In this work it is demonstrated that glucose constitutes the main substrate of energy metabolism of rabbit reticulocytes under aerobic conditions in the presence of 5 mM glucose. Amino acids and fatty acids are minor sources of energy. The shares of processes utilizing glucose in reticulocytes were estimated from tracer experiments. A new mathematical technique used permits the derivation of closed terms for the specific radioactivity of single positions of C atoms of the metabolites of the citrate cycle. By means of regression analysis, the undetermined flux rates in the citrate cycle were calculated. On the basis of the data an overall balance sheet of glucose utilization and of ATP generation is given. About 45% of the glucose of reticulocytes is catabolized via the citrate cycle, about the same percentage yields lactate. Only 2% of the glucose was oxidized in the oxidative pentose pathway whereas the remainder is used for the formation of serine and glycine required for hemoglobin synthesis. These results are related to knowledge about the main processes utilizing ATP in reticulocytes, i.e. the synthesis of hemoglobin and the energy-dependent proteolysis. Our approach to the investigation of metabolic relations in the reticulocytes can be applied to other tissues in which equilibria between large metabolite pools play a role.

  3. Effects of capsaicin, green tea and CH-19 sweet pepper on appetite and energy intake in humans in negative and positive energy balance

    DEFF Research Database (Denmark)

    Reinbach, Helene Christine; Møller, P.; Smeets, A.

    2009-01-01

    the effects on appetite, energy intake, body weight and heart rate were assessed. Results CH-19 sweet pepper and a combination of capsaicin and green tea reduced energy intake during positive energy balance. Capsaicin and green tea suppressed hunger and increased satiety more during negative than during...... ingredients may therefore be helpful in reducing energy intake and might support weight loss periods by relatively sustaining satiety and suppressing hunger....

  4. Potential evaporation estimation through an unstressed surface energy balance and its sensitivity to climate change

    Science.gov (United States)

    Barella-Ortiz, A.; Polcher, J.; Tuzet, A.; Laval, K.

    2013-06-01

    Potential evaporation (ETP) is a basic input for hydrological and agronomic models, as well as a key variable in most actual evaporation estimations. It has been approached through several diffusive and energy balance methods, out of which the Penman-Monteith equation is recommended as the standard one. In order to deal with the diffusive approach, ETP must be estimated at a sub-diurnal frequency, as currently done in land surface models (LSM). This study presents an improved method, developed in the ORCHIDEE LSM, which consists in estimating ETP through an unstressed surface energy balance (USEB method). The results confirm the quality of the estimation which is currently implemented in the model (Milly, 1992). ETP has also been estimated using a reference equation (computed at a daily time step) provided by the Food and Agriculture Organization (FAO). First, a comparison for a reference period under current climate conditions, shows that both formulations differ, specially in arid areas. However, they supply similar values when FAO's assumption of neutral stability conditions is relaxed, by replacing FAO's aerodynamic resistance by the model's one. Furthermore, if the vapour pressure deficit (VPD) estimated for FAO's equation, is substituted by ORCHIDEE's VPD or its humidity gradient, the daily mean estimate is further improved. In a second step, ETP's sensitivity to climate change is assessed comparing trends in both formulations for the 21st Century. It is found that the USEB method shows a higher sensitivity. Both VPD and the model's humidity gradient, as well as the aerodynamic resistance have been identified as key parameters in governing ETP trends. Finally, the sensitivity study is extended to three empirical approximations based on temperature, net radiation and mass transfer (Hargreaves, Priestley-Taylor and Rohwer, respectively). The sensitivity of these methods is compared to the USEB method's one to test if simplified equations are able to reproduce

  5. Potential evaporation estimation through an unstressed surface energy balance and its sensitivity to climate change

    Directory of Open Access Journals (Sweden)

    A. Barella-Ortiz

    2013-06-01

    Full Text Available Potential evaporation (ETP is a basic input for hydrological and agronomic models, as well as a key variable in most actual evaporation estimations. It has been approached through several diffusive and energy balance methods, out of which the Penman–Monteith equation is recommended as the standard one. In order to deal with the diffusive approach, ETP must be estimated at a sub-diurnal frequency, as currently done in land surface models (LSM. This study presents an improved method, developed in the ORCHIDEE LSM, which consists in estimating ETP through an unstressed surface energy balance (USEB method. The results confirm the quality of the estimation which is currently implemented in the model (Milly, 1992. ETP has also been estimated using a reference equation (computed at a daily time step provided by the Food and Agriculture Organization (FAO. First, a comparison for a reference period under current climate conditions, shows that both formulations differ, specially in arid areas. However, they supply similar values when FAO's assumption of neutral stability conditions is relaxed, by replacing FAO's aerodynamic resistance by the model's one. Furthermore, if the vapour pressure deficit (VPD estimated for FAO's equation, is substituted by ORCHIDEE's VPD or its humidity gradient, the daily mean estimate is further improved. In a second step, ETP's sensitivity to climate change is assessed comparing trends in both formulations for the 21st Century. It is found that the USEB method shows a higher sensitivity. Both VPD and the model's humidity gradient, as well as the aerodynamic resistance have been identified as key parameters in governing ETP trends. Finally, the sensitivity study is extended to three empirical approximations based on temperature, net radiation and mass transfer (Hargreaves, Priestley–Taylor and Rohwer, respectively. The sensitivity of these methods is compared to the USEB method's one to test if simplified equations are

  6. A land surface scheme for atmospheric and hydrologic models: SEWAB (Surface Energy and Water Balance)

    Energy Technology Data Exchange (ETDEWEB)

    Mengelkamp, H.T.; Warrach, K.; Raschke, E. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    1997-12-31

    A soil-vegetation-atmosphere-transfer scheme is presented here which solves the coupled system of the Surface Energy and Water Balance (SEWAB) equations considering partly vegetated surfaces. It is based on the one-layer concept for vegetation. In the soil the diffusion equations for heat and moisture are solved on a multi-layer grid. SEWAB has been developed to serve as a land-surface scheme for atmospheric circulation models. Being forced with atmospheric data from either simulations or measurements it calculates surface and subsurface runoff that can serve as input to hydrologic models. The model has been validated with field data from the FIFE experiment and has participated in the PILPS project for intercomparison of land-surface parameterization schemes. From these experiments we feel that SEWAB reasonably well partitions the radiation and precipitation into sensible and latent heat fluxes as well as into runoff and soil moisture Storage. (orig.) [Deutsch] Ein Landoberflaechenschema wird vorgestellt, das den Transport von Waerme und Wasser zwischen dem Erdboden, der Vegetation und der Atmosphaere unter Beruecksichtigung von teilweise bewachsenem Boden beschreibt. Im Erdboden werden die Diffusionsgleichungen fuer Waerme und Feuchte auf einem Gitter mit mehreren Schichten geloest. Das Schema SEWAB (Surface Energy and Water Balance) beschreibt die Landoberflaechenprozesse in atmosphaerischen Modellen und berechnet den Oberflaechenabfluss und den Basisabfluss, die als Eingabedaten fuer hydrologische Modelle genutzt werden koennen. Das Modell wurde mit Daten des FIFE-Experiments kalibriert und hat an Vergleichsexperimenten fuer Landoberflaechen-Schemata im Rahmen des PILPS-Projektes teilgenommen. Dabei hat sich gezeigt, dass die Aufteilung der einfallenden Strahlung und des Niederschlages in den sensiblen und latenten Waermefluss und auch in Abfluss und Speicherung der Bodenfeuchte in SEWAB den beobachteten Daten recht gut entspricht. (orig.)

  7. Analytical study of the energy rate balance equation for the magnetospheric storm-ring current

    Directory of Open Access Journals (Sweden)

    A. L. Clúa de Gonzalez

    Full Text Available We present some results of the analytical integration of the energy rate balance equation, assuming that the input energy rate is proportional to the azimuthal interplanetary electric field, Ey, and can be described by simple rectangular or triangular functions, as approximations to the frequently observed shapes of Ey, especially during the passage of magnetic clouds. The input function is also parametrized by a reconnection-transfer efficiency factor α (which is assumed to vary between 0.1 and 1. Our aim is to solve the balance equation and derive values for the decay parameter τ compatible with the observed Dst peak values. To facilitate the analytical integration we assume a constant value for τ through the main phase of the storm. The model is tested for two isolated and well-monitored intense storms. For these storms the analytical results are compared to those obtained by the numerical integration of the balance equation, based on the interplanetary data collected by the ISEE-3 satellite, with the τ values parametrized close to those obtained by the analytical study. From the best fit between this numerical integration and the observed Dst the most appropriate values of τ are then determined. Although we specifically focus on the main phase of the storms, this numerical integration has been also extended to the recovery phase by an independent adjust. The results of the best fit for the recovery phase show that the values of τ may differ drastically from those corresponding to the main phase. The values of the decay parameter for the main phase of each event, τm, are found to be very sensitive to the adopted efficiency factor, α, decreasing as this factor increases. For the recovery phase, which is characterized by very low values of the power input, the response function becomes almost independent of the value of α and the resulting values for the decay time

  8. Analytical study of the energy rate balance equation for the magnetospheric storm-ring current

    Science.gov (United States)

    Clúa de Gonzalez, A. L.; Gonzalez, W. D.

    1998-11-01

    We present some results of the analytical integration of the energy rate balance equation, assuming that the input energy rate is proportional to the azimuthal interplanetary electric field, Ey, and can be described by simple rectangular or triangular functions, as approximations to the frequently observed shapes of Ey, especially during the passage of magnetic clouds. The input function is also parametrized by a reconnection-transfer efficiency factor (which is assumed to vary between 0.1 and 1). Our aim is to solve the balance equation and derive values for the decay parameter compatible with the observed Dst peak values. To facilitate the analytical integration we assume a constant value for through the main phase of the storm. The model is tested for two isolated and well-monitored intense storms. For these storms the analytical results are compared to those obtained by the numerical integration of the balance equation, based on the interplanetary data collected by the ISEE-3 satellite, with the values parametrized close to those obtained by the analytical study. From the best fit between this numerical integration and the observed Dst the most appropriate values of are then determined. Although we specifically focus on the main phase of the storms, this numerical integration has been also extended to the recovery phase by an independent adjust. The results of the best fit for the recovery phase show that the values of may differ drastically from those corresponding to the main phase. The values of the decay parameter for the main phase of each event, m, are found to be very sensitive to the adopted efficiency factor, , decreasing as this factor increases. For the recovery phase, which is characterized by very low values of the power input, the response function becomes almost independent of the value of and the resulting values for the decay time parameter, r, do not vary greatly as varies. As a consequence, the relative values of between the main and the

  9. Assessment of energy balance against the nutritional status of women carriers in the brickfields of West Bengal.

    Science.gov (United States)

    Bandyopadhyay, Bijetri; Sen, Devashish

    2016-09-01

    The Indian brick industry is an unorganized sector in which large numbers of migrant women workers are employed. A survey was conducted on 62 women workers working in different brickfields of West Bengal to assess their physiological workload, nutritional profile, total energy expenditure and energy balance. Energy intake was calculated using physiological fuel values of carbohydrate, fat and protein. From the results it is seen that 13% of the sample population falls under severe (grade III) chronic energy deficiency. The average daily consumption of the workers was comparatively lower than their daily energy expenditure, considering the nature of the job which falls under heavy to extremely heavy categories. This negative energy balance is effectively observed in the nutritional anthropometry data. Thus, an immediate ergonomics intervention with better nutrition should be implemented to improve the health status of the workers so they can safely continue to work for a longer period.

  10. Assessment of a dry and a wet route for the production of biofuels from microalgae: energy balance analysis.

    Science.gov (United States)

    Xu, Lixian; Wim Brilman, Derk W F; Withag, Jan A M; Brem, Gerrit; Kersten, Sascha

    2011-04-01

    In this study, the energy balance of two microalgae-to-biofuel concepts, one via a so called "dry route" (oil extraction from dried algae) and one via a "wet route" (oil extraction in the water phase), are assessed. Both routes are intended to convert the chemical energy contained in the microalgae into high-value biofuels with minimal fossil energy consumption. The analysis shows that the drying process in the dry route and the oil extraction process in the wet route consume a significant amount of energy. By coupling waste heat from a nearby power plant to the process, the energy balance can be improved and a potential fossil energy ratio (FER) up to 2.38 and 1.82 can be reached for the dry and wet route, respectively. The results indicate that based on current available technologies, the dry route has higher FER and the wet route has more potential in producing high valuable biofuels.

  11. Role of net radiation on energy balance closure in heterogeneous grasslands

    Directory of Open Access Journals (Sweden)

    C. Shao

    2011-03-01

    Full Text Available Low energy balance closure (EBC at a particular eddy-covariance flux site increased the uncertainties of carbon, water and energy measurements and thus hampered the urgent research of scaling up and modeling analysis through site combinations. A series of manipulative experiments were conducted in this study to explore the role of net radiation (Rn in the EBC in relation to spatial variability of vegetation characteristics, source area, sensor type, and dome condition in the Inner Mongolian grassland of Northern China. At all three sites, the daytime peak residual fluxes of EBC were consistently about 100 W m−2 regardless of radiometers (i.e., REBS Q7.1 or CNR1. The spatial variability in net radiation was 19 W m−2 (5% of Rn during the day and 7 W m−2 (16% at night, with an average of 13 W m−2 (11% from eight plot measurements across the three sites. Net radiation results were affected more by measurement source area in unclipped heterogeneous system than in clipped homogeneous vegetation. Large area measurement significantly (P<0.0001 increased by 9 W m−2 during the day and decreased by 4 W m−2 at night in unclipped treatments. With an increase in clipping intensity, net radiation decreased by 25 W m−2 (6% of Rn at midday and 81 MJ m−2 (6% during a growing season with heavier regular clipping than that in unclipped treatments. Additional effort in EBC between 9:00 and 15:00 LT is needed for future research because of high variation. Using this method, the EBC difference derived from the two types of net radiometers was only 6 W m−2. Results from Q7.1 with new domes were higher during the day but lower at night than those with used domes. Overall, the inclusion of the uncertainty in available energy accounted for 60% of the 100 W m−2 shortfalls in the lack

  12. Uncertainty analysis of the Operational Simplified Surface Energy Balance (SSEBop) model at multiple flux tower sites

    Science.gov (United States)

    Chen, Mingshi; Senay, Gabriel B.; Singh, Ramesh K.; Verdin, James P.

    2016-05-01

    Evapotranspiration (ET) is an important component of the water cycle - ET from the land surface returns approximately 60% of the global precipitation back to the atmosphere. ET also plays an important role in energy transport among the biosphere, atmosphere, and hydrosphere. Current regional to global and daily to annual ET estimation relies mainly on surface energy balance (SEB) ET models or statistical and empirical methods driven by remote sensing data and various climatological databases. These models have uncertainties due to inevitable input errors, poorly defined parameters, and inadequate model structures. The eddy covariance measurements on water, energy, and carbon fluxes at the AmeriFlux tower sites provide an opportunity to assess the ET modeling uncertainties. In this study, we focused on uncertainty analysis of the Operational Simplified Surface Energy Balance (SSEBop) model for ET estimation at multiple AmeriFlux tower sites with diverse land cover characteristics and climatic conditions. The 8-day composite 1-km MODerate resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) was used as input land surface temperature for the SSEBop algorithms. The other input data were taken from the AmeriFlux database. Results of statistical analysis indicated that the SSEBop model performed well in estimating ET with an R2 of 0.86 between estimated ET and eddy covariance measurements at 42 AmeriFlux tower sites during 2001-2007. It was encouraging to see that the best performance was observed for croplands, where R2 was 0.92 with a root mean square error of 13 mm/month. The uncertainties or random errors from input variables and parameters of the SSEBop model led to monthly ET estimates with relative errors less than 20% across multiple flux tower sites distributed across different biomes. This uncertainty of the SSEBop model lies within the error range of other SEB models, suggesting systematic error or bias of the SSEBop model is within the

  13. Uncertainty analysis of the Operational Simplified Surface Energy Balance (SSEBop) model at multiple flux tower sites

    Science.gov (United States)

    Chen, Mingshi; Senay, Gabriel B.; Singh, Ramesh K.; Verdin, James P.

    2016-01-01

    Evapotranspiration (ET) is an important component of the water cycle – ET from the land surface returns approximately 60% of the global precipitation back to the atmosphere. ET also plays an important role in energy transport among the biosphere, atmosphere, and hydrosphere. Current regional to global and daily to annual ET estimation relies mainly on surface energy balance (SEB) ET models or statistical and empirical methods driven by remote sensing data and various climatological databases. These models have uncertainties due to inevitable input errors, poorly defined parameters, and inadequate model structures. The eddy covariance measurements on water, energy, and carbon fluxes at the AmeriFlux tower sites provide an opportunity to assess the ET modeling uncertainties. In this study, we focused on uncertainty analysis of the Operational Simplified Surface Energy Balance (SSEBop) model for ET estimation at multiple AmeriFlux tower sites with diverse land cover characteristics and climatic conditions. The 8-day composite 1-km MODerate resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) was used as input land surface temperature for the SSEBop algorithms. The other input data were taken from the AmeriFlux database. Results of statistical analysis indicated that the SSEBop model performed well in estimating ET with an R2 of 0.86 between estimated ET and eddy covariance measurements at 42 AmeriFlux tower sites during 2001–2007. It was encouraging to see that the best performance was observed for croplands, where R2 was 0.92 with a root mean square error of 13 mm/month. The uncertainties or random errors from input variables and parameters of the SSEBop model led to monthly ET estimates with relative errors less than 20% across multiple flux tower sites distributed across different biomes. This uncertainty of the SSEBop model lies within the error range of other SEB models, suggesting systematic error or bias of the SSEBop model is within

  14. First results from the International Urban Energy Balance Model Comparison: Model Complexity

    Science.gov (United States)

    Blackett, M.; Grimmond, S.; Best, M.

    2009-04-01

    A great variety of urban energy balance models has been developed. These vary in complexity from simple schemes that represent the city as a slab, through those which model various facets (i.e. road, walls and roof) to more complex urban forms (including street canyons with intersections) and features (such as vegetation cover and anthropogenic heat fluxes). Some schemes also incorporate detailed representations of momentum and energy fluxes distributed throughout various layers of the urban canopy layer. The models each differ in the parameters they require to describe the site and the in demands they make on computational processing power. Many of these models have been evaluated using observational datasets but to date, no controlled comparisons have been conducted. Urban surface energy balance models provide a means to predict the energy exchange processes which influence factors such as urban temperature, humidity, atmospheric stability and winds. These all need to be modelled accurately to capture features such as the urban heat island effect and to provide key information for dispersion and air quality modelling. A comparison of the various models available will assist in improving current and future models and will assist in formulating research priorities for future observational campaigns within urban areas. In this presentation we will summarise the initial results of this international urban energy balance model comparison. In particular, the relative performance of the models involved will be compared based on their degree of complexity. These results will inform us on ways in which we can improve the modelling of air quality within, and climate impacts of, global megacities. The methodology employed in conducting this comparison followed that used in PILPS (the Project for Intercomparison of Land-Surface Parameterization Schemes) which is also endorsed by the GEWEX Global Land Atmosphere System Study (GLASS) panel. In all cases, models were run

  15. Mass, energy and material balances of SRF production process. Part 3: solid recovered fuel produced from municipal solid waste.

    Science.gov (United States)

    Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne

    2015-02-01

    This is the third and final part of the three-part article written to describe the mass, energy and material balances of the solid recovered fuel production process produced from various types of waste streams through mechanical treatment. This article focused the production of solid recovered fuel from municipal solid waste. The stream of municipal solid waste used here as an input waste material to produce solid recovered fuel is energy waste collected from households of municipality. This article presents the mass, energy and material balances of the solid recovered fuel production process. These balances are based on the proximate as well as the ultimate analysis and the composition determination of various streams of material produced in a solid recovered fuel production plant. All the process streams are sampled and treated according to CEN standard methods for solid recovered fuel. The results of the mass balance of the solid recovered fuel production process showed that 72% of the input waste material was recovered in the form of solid recovered fuel; 2.6% as ferrous metal, 0.4% as non-ferrous metal, 11% was sorted as rejects material, 12% as fine faction and 2% as heavy fraction. The energy balance of the solid recovered fuel production process showed that 86% of the total input energy content of input waste material was recovered in the form of solid recovered fuel. The remaining percentage (14%) of the input energy was split into the streams of reject material, fine fraction and heavy fraction. The material balances of this process showed that mass fraction of paper and cardboard, plastic (soft) and wood recovered in the solid recovered fuel stream was 88%, 85% and 90%, respectively, of their input mass. A high mass fraction of rubber material, plastic (PVC-plastic) and inert (stone/rock and glass particles) was found in the reject material stream.

  16. Energy and water balance studies of a snow cover during snowmelt period at a high arctic site

    Science.gov (United States)

    Bruland, O.; Maréchal, D.; Sand, K.; Killingtveit, Å.

    The predicted global warming is supposed to have an enhanced effect on the arctic regions. How this will influence the water, carbon dioxide and methane balances in the European arctic tundra is the objective of the EU-funded project ``Understanding Land Surface Physical Processes in the Arctic'' (LAPP), to which where SINTEF is one of several contributors. The snow cover is one of the limiting factors for these exchange processes and knowledge of how it behaves and will behave under a different climate is important. Data collected for water and energy balance studies in an area close to Ny-Ålesund at 79°N at Svalbard are the basis of this study. Measurements during the ablation periods since 1992 show an average air temperature for the periods of 2.1°C, an average incoming shorwave radiation of 230W/m2 and an average measured runoff intensity of 14mm/day with a maximum of 68mm/day. Three models of different complexity are tested in order to simulate the water and energy balance of a snow cover on the arctic tundra. The three models are: a complex numerical model (CROCUS), a simple energy balance model and a temperature index model. The simulations were carried out for the melt periods in 1992 and 1996 as these two periods represent very different meteorological conditions. The results of these simulations exposed weaknesses in all the models. The energy balance model lacks calculation of cold content in the snowpack. This influences both the outgoing longwave radiation and the timing of the melt. Due to the effect of compensating errors in the simulations, CROCUS performed better than the simple energy balance model but also this model has problems with the simulation of outgoing longwave radiation. The temperature index model does not perform well for snowmelt studies in regions were radiation is the main driving energy source for the melt.

  17. Adjustment of the components of energy balance in response to temperature change in Ostrea edulis

    Energy Technology Data Exchange (ETDEWEB)

    Newell, R.C.; Johson, L.G.; Kofoed, L.H.

    1977-01-01

    Routine oxygen consumption (V/sub 02/ ..mu..l 285 mg/sup -1/ h/sup -1/) by specimens of Ostrea acclimated to temperatures between 5/sup 0/ and 25/sup 0/C increases with exposure temperature throughout much of the range 5 to 30/sup 0/C. There is little evidence of a relative suppression of the acutely-measured rate: temperature curves for routine oxygen consumption following warm acclimation. Energetic costs in Ostrea thus rise sharply with increase of environmental temperature. The clearance rate (V/sub w/, ml 285 mg/sup -1/ h/sup -1/) of Phaeodactylum measured synchronously shows a marked thermal optimum within the range 15 to 28/sup 0/C, followed by a decline towards high exposure temperatures. Maximal clearance rates of 600 to 750 ml water h/sup -1/ occur approximately 5/sup 0/C above the temperature to which the animals have been acclimated and are adjusted according to environmental temperature. The changes in filtration efficiency)V/sub w//V/sub 02/, ml/..mu..l) in Ostrea following thermal acclimation are controlled by compensatory responses of the irrigation rate rather than by a relative reduction of energy losses from metabolism. Because the clearance rate declines in animals acclimated to 25/sup 0/C, whereas the metabolic losses increase throughout the temperature range 5 to 30/sup 0/C, maximum filtration efficiency is achieved at 20/sup 0/C. Calculation of the energetic cost of filtration suggests that the improvement of filtration following warm acclimation offsets metabolic energy losses even at low food concentrations in Ostrea. Even if energy losses not accounted for in the study were substantial, a positive index of energy balance could be maintained during the summer months at ration levels which commonly occur in inshore waters.

  18. Bioenergy from stillage anaerobic digestion to enhance the energy balance ratio of ethanol production.

    Science.gov (United States)

    Fuess, Lucas Tadeu; Garcia, Marcelo Loureiro

    2015-10-01

    The challenges associated with the availability of fossil fuels in the past decades intensified the search for alternative energy sources, based on an ever-increasing demand for energy. In this context, the application of anaerobic digestion (AD) as a core treatment technology in industrial plants should be highlighted, since this process combines the pollution control of wastewaters and the generation of bioenergy, based on the conversion of the organic fraction to biogas, a methane-rich gaseous mixture that may supply the energetic demands in industrial plants. In this context, this work aimed at assessing the energetic potential of AD applied to the treatment of stillage, the main wastewater from ethanol production, in an attempt to highlight the improvements in the energy balance ratio of ethanol by inserting the heating value of methane as a bioenergy source. At least 5-15% of the global energy consumption in the ethanol industry could be supplied by the energetic potential of stillage, regardless the feedstock (i.e. sugarcane, corn or cassava). The association between bagasse combustion and stillage anaerobic digestion in sugarcane-based distilleries could provide a bioenergy surplus of at least 130% of the total fossil fuel input into the ethanol plant, considering only the energy from methane. In terms of financial aspects, the economic gains could reach US$ 0.1901 and US$ 0.0512 per liter of produced ethanol, respectively for molasses- (Brazil) and corn-based (EUA) production chains. For large-scale (∼1000 m(3)EtOH per day) Brazilian molasses-based plants, an annual economic gain of up to US$ 70 million could be observed. Considering the association between anaerobic and aerobic digestion, for the scenarios analyzed, at least 25% of the energetic potential of stillage would be required to supply the energy consumption with aeration, however, more suitable effluents for agricultural application could be produced. The main conclusion from this work

  19. Impact of yogurt on appetite control, energy balance, and body composition.

    Science.gov (United States)

    Tremblay, Angelo; Doyon, Caroline; Sanchez, Marina

    2015-08-01

    Recent data support the idea that regular yogurt consumption promotes body weight stability. The simplest explanation is that regular consumption of healthful foods such as yogurt results in decreased intake of less healthful foods containing high amounts of fat and/or sugar. There is also evidence to suggest that the high calcium and protein contents of yogurt and other dairy foods influence appetite and energy intake. The existence of a calcium-specific appetite control mechanism has been proposed. Milk proteins differ in terms of absorption rate and post-absorptive responses, which can influence their satiating properties. Studies in humans have shown that consumption of milk and yogurt increases the circulating concentration of the anorectic peptides glucagon-like peptide (GLP)-1 and peptide YY (PYY). The food matrix can also affect appetite and satiety. Yogurt is a fermented milk that contains bacteria that enrich the microbiota of the host. It appears that lean vs obese humans differ in the composition of their gut microbiota. The available relevant literature suggests that yogurt is a food that facilitates the regulation of energy balance.

  20. Energy balance, greenhouse gas emissions, and profitability of thermobarical pretreatment of cattle waste in anaerobic digestion.

    Science.gov (United States)

    Budde, Jörn; Prochnow, Annette; Plöchl, Matthias; Suárez Quiñones, Teresa; Heiermann, Monika

    2016-03-01

    In this study modeled full scale application of thermobarical hydrolysis of less degradable feedstock for biomethanation was assessed in terms of energy balance, greenhouse gas emissions, and economy. Data were provided whether the substitution of maize silage as feedstock for biogas production by pretreated cattle wastes is beneficial in full-scale application or not. A model device for thermobarical treatment has been suggested for and theoretically integrated in a biogas plant. The assessment considered the replacement of maize silage as feedstock with liquid and/or solid cattle waste (feces, litter, and feed residues from animal husbandry of high-performance dairy cattle, dry cows, and heifers). The integration of thermobarical pretreatment is beneficial for raw material with high contents of organic dry matter and ligno-cellulose: Solid cattle waste revealed very short payback times, e.g. 9 months for energy, 3 months for greenhouse gases, and 3 years 3 months for economic amortization, whereas, in contrast, liquid cattle waste did not perform positive replacement effects in this analysis.

  1. Seasonal and Interannual Variation in Energy Balance in the Semiarid Grassland Area of China

    Directory of Open Access Journals (Sweden)

    Qun’ou Jiang

    2015-01-01

    Full Text Available Near surface energy budget changes have been proved to be induced by the land cover conversion through changing the surface physical properties, which can further impact the regional climate change. This study applies the DLS model to simulate the land cover under the business as usual (BAU scenario and then analyses the seasonal and interannual variation of energy balance in the semiarid grassland area of China based on the simulated land cover with the Weather Research and Forecasting (WRF model. The results indicate that the grassland will show a growing trend under the BAU scenario. Downward long wave radiation and downward short wave radiation will all have small-scale increase with time going by, while the surface net radiation will decrease from 2030 to 2050. However, there is obvious seasonal variation. Summer has the highest downward long wave radiation and downward short wave radiation, followed by spring and autumn. The lowest are in winter. As for the net surface radiation, there is obvious decrease in southeast of study area due to returning cropland to grassland. Those research conclusions can offer valuable information for the land use planning and relieving the effects of land cover change on climate change at the semiarid grassland area.

  2. Interactions between negative energy balance, metabolic diseases, uterine health and immune response in transition dairy cows.

    Science.gov (United States)

    Esposito, Giulia; Irons, Pete C; Webb, Edward C; Chapwanya, Aspinas

    2014-01-30

    The biological cycles of milk production and reproduction determine dairying profitability thus making management decisions dynamic and time-dependent. Diseases also negatively impact on net earnings of a dairy enterprise. Transition cows in particular face the challenge of negative energy balance (NEB) and/or disproportional energy metabolism (fatty liver, ketosis, subacute, acute ruminal acidosis); disturbed mineral utilization (milk fever, sub-clinical hypocalcemia); and perturbed immune function (retained placenta, metritis, mastitis). Consequently NEB and reduced dry matter intake are aggravated. The combined effects of all these challenges are reduced fertility and milk production resulting in diminishing profits. Risk factors such as NEB, inflammation and impairment of the immune response are highly cause-and-effect related. Thus, managing cows during the transition period should be geared toward reducing NEB or feeding specially formulated diets to improve immunity. Given that all cows experience a reduced feed intake and body condition, infection and inflammation of the uterus after calving, there is a need for further research on the immunology of transition dairy cows. Integrative approaches at the molecular, cellular and animal level may unravel the complex interactions between disturbed metabolism and immune function that predispose cows to periparturient diseases.

  3. Eating patterns, diet quality and energy balance: from the macro- to the microscopic.

    Science.gov (United States)

    Lowe, Michael R

    2014-07-01

    As a discussant for the 2013 IBRC Symposium on Eating Patterns, Diet Quality and Energy Balance at Purdue University, I describe here several reflections I had on the papers as a whole. I initially focus on the keynote address by Dr. Leonard. His address suggested that the evolutionary development of Homo sapiens during the past 2 million years may have "prepared" humans to seek and consume food beyond their immediate energy needs, a predisposition that may have rendered humans particularly vulnerable to modern food environments. Additional observations include: 1) the importance of differentiating between a given appetitive variable (e.g., snacking) as a potential cause versus consequence of an outcome of interest (e.g., obesity), 2) the need to move beyond research on the consummatory phase of appetite to the anticipatory phase of appetite, and 3) the opportunity that exists to take the many obesogenic nutritional influences documented in the symposium and "turn them on their heads" to facilitate, rather than undermine, long-term weight control.

  4. Whey protein-effects on energy balance link the intestinal mechanisms of energy absorption with adiposity and hypothalamic neuropeptide gene expression.

    Science.gov (United States)

    Nilaweera, Kanishka N; Cabrera-Rubio, Raul; Speakman, John R; O' Connor, Paula M; McAuliffe, AnneMarie; Guinane, Caitriona M; Lawton, Elaine; Crispie, Fiona; Aguilera, Mònica; Stanley, Maurice; Boscaini, Serena; Joyce, Susan; Melgar, Silvia; Cryan, John F; Cotter, Paul D

    2017-03-21

    We tested the hypothesis that dietary whey protein isolate (WPI) affects the intestinal mechanisms related to energy absorption and that the resulting energy deficit is compensated by changes in energy balance to support growth. C57BL/6 mice were provided a diet enriched with WPI with varied sucrose content, and the impact on energy balance related parameters were investigated. As part of a high sucrose diet, WPI reduced the hypothalamic expression of pro-opiomelanocortin gene expression and increased energy intake. The energy expenditure was unaffected, but epididymal weight was reduced, indicating an energy loss. Notably, there was a reduction in the ileum gene expression for amino acid transporter SLC6a19, glucose transporter 2 and fatty acid transporter 4. The composition of the gut microbiota also changed, where Firmicutes were reduced. The above changes indicated a reduced energy absorption through the intestine. We propose that this mobilised energy in the adipose tissue and caused hypothalamic changes that increased energy intake, acting to counteract the energy deficit arising in the intestine. Lowering the sucrose content in the WPI diet increased energy expenditure. This further reduced epididymal weight and plasma leptin, whereupon hypothalamic ghrelin gene expression and the intestinal weight were both increased. These data suggest that when the intestine-adipose-hypothalamic pathway is subjected to an additional energy loss (now in the adipose tissue), compensatory changes attempt to assimilate more energy. Notably, WPI and sucrose content interact to enable the component mechanisms of this pathway.

  5. Hydrocarbon reserves, energy assurance and macroeconomics: a complex balance; Reservas de hidrocarburos, seguridad energetica y macroeconomia: un balance complejo

    Energy Technology Data Exchange (ETDEWEB)

    Alarco Tosoni, German [TYH Economia, S.A. de C.V., Mexico, D.F.(Mexico)

    2006-11-15

    The available public information relative to the limited discovered and undiscovered crude and natural gas reserves in Mexico, from an international comparison perspective, is analyzed. Through the evaluation of the national energy programs, a limited conception of energy security is made clear concerning that posed by the other countries within North America. Various scenarios are stated regarding proved/production reserves to 2020 which will induce, together with the notion of energy security, a reduction in the current production levels - crude oil exports. The paradox referring to the fact that given certain reduction levels in the exports' crude platform, both the product level as well as real public expenditure will rise, is discovered. Finally, the macroeconomic effects of the proposal and of the necessary complementary policies needed to be designed and implemented in order to improve our macroeconomic performance are also evaluated. [Spanish] Se analiza la informacion publica disponible sobre las reservas limitadas de crudo y gas natural descubiertas y no descubiertas de Mexico en una perspectiva internacional comparada. Al evaluar los programas energeticos nacionales se transparenta una concepcion limitada de la seguridad energetica, respecto de lo planteado por los otros paises de America del Norte. Se plantean diferentes escenarios de reservas probadas/produccion al 2020 que inducirian, conjuntamente con la incorporacion de la nocion de seguridad energetica, a reducir los niveles actuales de produccion - exportacion de crudo. Se descubre la paradoja de que para determinados niveles de reduccion de la plataforma de exportacion de crudo tanto el nivel de producto como de gasto publico real aumentan. Por ultimo, se evaluan tanto los efectos macroeconomicos de la propuesta como de algunas politicas complementarias que seria necesario disenar e implantar para mejorar nuestro desempeno macroeconomico.

  6. Evaluation of water-energy balance frameworks to predict the sensitivity of streamflow to climate change

    Directory of Open Access Journals (Sweden)

    M. Renner

    2012-05-01

    Full Text Available Long term average change in streamflow is a major concern in hydrology and water resources management. Some simple analytical methods exist for the assessment of the sensitivity of streamflow to climatic variations. These are based on the Budyko hypothesis, which assumes that long term average streamflow can be predicted by climate conditions, namely by annual average precipitation and evaporative demand. Recently, Tomer and Schilling (2009 presented an ecohydrological concept to distinguish between effects of climate change and basin characteristics change on streamflow. We relate the concept to a coupled consideration of the water and energy balance. We show that the concept is equivalent to the assumption that the sum of the ratio of annual actual evapotranspiration to precipitation and the ratio of actual to potential evapotranspiration is constant, even when climate conditions are changing.

    Here, we use this assumption to derive analytical solutions to the problem of streamflow sensitivity to climate. We show how, according to this assumption, climate sensitivity would be influenced by different climatic conditions and the actual hydrological response of a basin. Finally, the properties and implications of the method are compared with established Budyko sensitivity methods and illustrated by three case studies. It appears that the largest differences between both approaches occur under limiting conditions. Specifically, the sensitivity framework based on the ecohydrological concept does not adhere to the water and energy limits, while the Budyko approach accounts for limiting conditions by increasing the sensitivity of streamflow to a catchment parameter encoding basin characteristics. Our findings do not support any application of the ecohydrological concept under conditions close to the water or energy limits, instead we suggest a correction based on the Budyko framework.

  7. Comparison of root water uptake modules using either the surface energy balance or potential transpiration

    Science.gov (United States)

    Braud, Isabelle; Varado, Noémie; Olioso, Albert

    2005-01-01

    Numerical models simulating changes in soil water content with time rely on accurate estimation of root water uptake. This paper considers two root water uptake modules that have a compensation mechanism allowing for increased root uptake under conditions of water stress. These modules, proposed by Lai and Katul and Li et al. [Adv. Water Resour. 23 (2000) 427 and J. Hydrol. 252 (2001) 189] use potential transpiration weighted, for each soil layer, by a water stress and a compensation function in order to estimate actual transpiration. The first objective of the paper was to assess the accuracy of the proposed root extraction modules against two existing data sets, acquired under dry conditions for a winter wheat and a soybean crop. In order to perform a fair comparison, both modules were included as possible root water extraction modules within the Simple Soil Plant Atmosphere Transfer (SiSPAT) model. In this first set of simulations, actual transpiration was calculated using the solution of the surface energy budget as implemented in the SiSPAT model. Under such conditions, both root extraction modules were able to reproduce accurately the time evolution of soil moisture at various depths, soil water storage and daily evaporation. Results were generally improved when we activated the compensation mechanisms. However, we showed that Lai and Katul [Adv. Water Resour. 23 (2000) 427] module was sensitive to soil hydraulic properties through its water stress function, whereas the Li et al. [J. Hydrol. 252 (2001) 189] module was not very sensitive to the specification of its parameter. The latter module is therefore recommended for inclusion into a larger scale hydrological model, due to its robustness. When water balance models are run at larger scales or on areas with scarce data, actual transpiration is often calculated using models based on potential transpiration without solving the surface energy balance. The second objective of the paper was to assess the loss of

  8. The Water, Energy and Food Nexus: Finding the Balance in Infrastructure Investment

    Science.gov (United States)

    Huber-lee, A. T.; Wickel, B.; Kemp-Benedict, E.; Purkey, D. R.; Hoff, H.; Heaps, C.

    2013-12-01

    There is increasing evidence that single-sector infrastructure planning is leading to severely stressed human and ecological systems. There are a number of cross-sectoral impacts in these highly inter-linked systems. Examples include: - Promotion of biofuels that leads to conversion from food crops, reducing both food and water security. - Promotion of dams solely built for hydropower rather than multi-purpose uses, that deplete fisheries and affect saltwater intrusion dynamics in downstream deltas - Historical use of water for cooling thermal power plants, with increasing pressure from other water uses, as well as problems of increased water temperatures that affect the ability to cool plants efficiently. This list can easily be expanded, as these inter-linkages are increasing over time. As developing countries see a need to invest in new infrastructure to improve the livelihoods of the poor, developed countries face conditions of deteriorating infrastructure with an opportunity for new investment. It is crucial, especially in the face of uncertainty of climate change and socio-political realities, that infrastructure planning factors in the influence of multiple sectors and the potential impacts from the perspectives of different stakeholders. There is a need for stronger linkages between science and policy as well. The Stockholm Environment Institute is developing and implementing practical and innovative nexus planning approaches in Latin America, Africa and Asia that brings together stakeholders and ways of integrating uncertainty in a cross-sectoral quantitative framework using the tools WEAP (Water Evaluation and Planning) and LEAP (Long-range Energy Alternatives Planning). The steps used include: 1. Identify key actors and stakeholders via social network analysis 2. Work with these actors to scope out priority issues and decision criteria in both the short and long term 3. Develop quantitative models to clarify options and balances between the needs and

  9. Potential Evaporation Computation through an Unstressed Surface Energy Balance and its Sensitivity to Climate Change Effect

    Science.gov (United States)

    Barella-Ortiz, Anaïs; Polcher, Jan; Tuzet, Andrée; Laval, Katia

    2013-04-01

    Potential evaporation (ETP) is a basic input for hydrological and agronomic models, as well as a key variable in most actual evaporation estimations. It has been approached through several diffusive and energy balance methods, out of which the Penman-Monteith equation is recommended as the standard one. In order to deal with the diffusive approach, ETP must be estimated at a sub-diurnal frequency, as currently done in land surface models (LSM). This study presents an improved method, developed in the ORCHIDEE LSM, which consists in estimating ETP through an unstressed surface energy balance (USEB method). The values provided confirm the quality of the estimation which is currently implemented (Milly, 1992). ETP has also been estimated using a reference equation (computed at a daily time step) provided by the Food and Agriculture Organization (FAO). In the first place, a comparison for a reference period of 11 years shows that both formulations differ, specially in arid areas. However, they supply similar values when FAO's assumption of neutral stability conditions is relaxed, by replacing FAO's aerodynamic resistance by the model's one. Additionally, if the vapour pressure deficit (VPD) is also substituted by either ORCHIDEE's VPD or its humidity gradient, the daily mean estimate is further improved. ETP's sensitivity to climate change is assessed comparing trends in both formulations for the 21st Century. It is found that the USEB method shows a higher sensitivity mainly due to FAO's assumption of neutral stability conditions and to a lesser extent, to the approximation proposed for the VPD. Both FAO's VPD and the model's humidity gradient, as well as ORCHIDEE's aerodynamic resistance have been identified as key parameters in governing ETP trends. Finally, the sensitivity study is extended to 3 empirical approximations based on temperature, net radiation and mass transfer (Hargreaves, Priestley - Taylor and Rohwer, respectively). When compared to the USEB method

  10. Reconstructing winter snowpack accumulation from energy balance simulations in alpine glacierised basins

    Science.gov (United States)

    Clemenzi, I.; Carenzo, M.; Morin, S.; Pellicciotti, F.

    2010-12-01

    Snow water equivalent has been reconstructed using a combination of melt modeling and snow cover images that provide the exact date of snow disappearance for large North-american basins including high elevation headwater catchments, but never for small mountainous basins in the Alps. This approach is based on the fact that integration of modeled snowmelt over the time required to melt all of the snow in a given area effectively reconstructs initial Snow Water Equivalent (SWE). It requires an accurate model of snow ablation and precise information on the disappearance of the snow. In this paper, we attempt to use this method for reconstructing the winter accumulation in Alpine glacierised catchments. Late winter accumulation represents the initial conditions for simulations of summer ablation and has been shown to be a major source of error in distributed simulation of glacier ablation and models of glacier runoff. In this work, we first test the applicability of a surface, two-layer energy balance model and an enhanced temperature index model against accurate snowmelt simulations obtained with the multi-layer detailed snow model CROCUS, in order to assess the model complexity required to achieve accurate estimates of melt rates for winter conditions. While energy balance modeling is well established for computation of summer ablation processes, melt models often neglect or crudely simplify processes that are important typical during winter and spring conditions such as refreezing into the snowpack, densification of snow and other subsurface processes. We quantify their relative importance and evaluate the accuracy of the two simpler models at the point scale. In a second step, we use the melt simulations to reconstruct the winter snowpack water equivalent both at the point and at the distributed scale, using measurements of snow depth at Ultrasonic Depth Gauges and photos from an automatic camera, respectively, to determine the exact date of snow disappearance. The

  11. The effects of pH on carbon material and energy balances in hydrogen-producing Clostridium tyrobutyricum JM1.

    Science.gov (United States)

    Jo, Ji Hye; Lee, Dae Sung; Park, Jong Moon

    2008-11-01

    The effects of pH on hydrogen fermentation of glucose by newly isolated H(2)-producing bacterium Clostridium tyrobutyricum JM1 were investigated in batch cultivations. The changes of carbon material and energy balances by pH conditions provided useful information for understanding and interpreting the regulatory system of the microorganism, and for optimization of a desired product, in this case, molecular hydrogen. The most probable metabolic pathways of C. tyrobutyricum JM1 were determined through an accurate analysis of stoichiometry and the consistency of the experimental data, checked by high carbon recovery. The carbon material and energy balances were adequately applied to estimate the carbon-flow distribution. They suggested that pH 6.3 was appropriate to maximize hydrogen production with a high concentration of butyrate and balanced activities of NADH.

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

    Science.gov (United States)

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

    2013-09-01

    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.

  13. Modelling the water and energy balances of Amazonian rainforest and pasture using Anglo-Brazilian Amazonian climate observation study data

    NARCIS (Netherlands)

    Ashby, M.

    1999-01-01

    A soil-vegetation-atmosphere transfer model, SWAPS, is introduced. The model is based on existing models for two-layer evaporation and energy balance, interception evaporation and unsaturated soil moisture transport. The model includes a physically based parameterisation for the soil surface resista

  14. Leptin concentrations in relation to energy balance, milk yield, intake, live weight and estrus in dairy cows

    NARCIS (Netherlands)

    Liefers, S.C.; Veerkamp, R.F.; Pas, te M.F.W.; Delavaud, C.; Chilliard, Y.; Lende, van der T.

    2003-01-01

    The objective of this study was to describe fluctuations in leptin concentrations during late pregnancy and lactation and to investigate how those fluctuations are related to energy balance, milk yield, milk components, dry matter intake, live weight, first postpartum luteal activity, and first obse

  15. Updated cloud physics in a regional atmospheric climate model improves the modelled surface energy balance of Antarctica

    NARCIS (Netherlands)

    van Wessem, J.M.; Reijmer, C.H.; Lenaerts, J.T.M.; van de Berg, W.J.; van den Broeke, M.R.; van Meijgaard, E.

    2014-01-01

    In this study the effects of changes in the physics package of the regional atmospheric climate model RACMO2 on the modelled surface energy balance, nearsurface temperature and wind speed of Antarctica are presented. The physics package update primarily consists of an improved turbulent and radiativ

  16. Process monitoring and modeling of a continuous pharmaceutical from powder to tablet process Line using a mass & energy balance

    DEFF Research Database (Denmark)

    Beer, Thomas De; Mortier, Séverine Thérèse F.C.; Gernaey, Krist

    2014-01-01

    The intention to shift from batch to continuous production processes within the pharmaceutical industry enhances the need to monitor and control the process in-line and real-time to continuously guarantee the end-product quality. Mass and energy balances have been successfully applied to a drying...

  17. A Health Probe in College Students Living in Los Angeles and in Taiwan: Dietary Pattern, Physical Activity and Energy Balance

    Science.gov (United States)

    Wang, Li Hui; Yang, Hsin Ling; Chen, Yin Chang; Davis, Rebecca; Schwartz, Miriam E.; Tam, Chick F.

    2008-01-01

    The objective was to examine differences of dietary pattern, physical activity and energy balance in 240 college students with 137 of them enrolled in California State University, Los Angeles (LA) and the other 93 enrolled in China Medical University in Taichung, Taiwan (TW). A three-day dietary record and a 24-hour physical activity journal were…

  18. Caffeine and carbohydrate supplementation during exercise when in negative energy balance: effects on performance, metabolism, and salivary cortisol.

    Science.gov (United States)

    Slivka, Dustin; Hailes, Walter; Cuddy, John; Ruby, Brent

    2008-12-01

    The ingestion of carbohydrate (+CHO) and caffeine (+CAF) during exercise is a commonly used ergogenic practice. Investigations are typically conducted with subjects who are in a rested state after an overnight fast. However, this state of positive energy balance is not achieved during many work and exercise circumstances. The aim of this study was to evaluate the substrate use and performance effects of caffeine and carbohydrate consumed alone and in combination while participants were in negative energy balance. Male participants (n = 9; 23 +/- 3 years; 74.1 +/- 10.6 kg) completed 4 trials in random order: -CAF/-CHO, -CAF/+CHO, +CAF/-CHO, and +CAF/+CHO. Diet and exercise were prescribed for 2 days before each trial to ensure negative energy balance. For each trial, before and after 2 h of cycling at 50% of maximal watts, a saliva sample and a muscle biopsy (vastus lateralis) were obtained. A simulated 20 km time trial was then performed. The respiratory exchange ratio was higher (p 0.05), or any of the other trials. When co-ingested with carbohydrate, caffeine increased fat use and decreased nonmuscle glycogen carbohydrate use over carbohydrate alone when participants are in negative energy balance; however, caffeine had no effect on the 20 km cycling time trial performance.

  19. Surface energy balance in the ablation zone of Langfjordjøkelen, an arctic, maritime glacier in northern Norway

    NARCIS (Netherlands)

    Giesen, Rianne H.; Andreassen, Liss M.; Oerlemans, Johannes; van den Broeke, Michiel R.

    2014-01-01

    Glaciers in northern and southern Norway are subject to different daily and seasonal cycles of incoming solar radiation, which is presumably reflected in the importance of net solar radiation in their surface energy balance. We present a 3 year continuous record from an automatic weather station in

  20. Canola energy balance for bio diesel production; Balanco energetico da cultura da canola para a producao de biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Gazzoni, Decio Luiz; Avila, Marcio Turra de [Empresa Brasileira de Pesquisa Agropecuaria (Embrapa-Soja), Londrina, PR (Brazil)], Emails: gazzonid@cnpso.embrapa.br, marcio@cnpso.embrapa.br; Borges, Jose Luiz Bernardo [Universidade Estadual de Londrina (UEL), PR (Brazil)], Emails: borges@cnpso.embrapa.br; Felici, Paulo Henrique Nardon [Bunge Alimentos S.A., Orindiuva, SP (Brazil). Div. de Acucar e Etanol], Email: paulo.felici@bunge.com

    2009-10-15

    Energy balance is the best parameter to define technical viability and sustainability of an agroenergy programme, by establishing the relationship between bio fuel and co-products of a given feedstock energy output and the quantity of energy inputs during the production process, including the agricultural and industrial stages. In this study, the amount of energy necessary to produce bio diesel from canola (Brassica napus L.) was calculated as well as the energy contents of canola oil and cake. We took into account the activities requesting energy expenditure in the cultivation, transport and canola processing. Considering meal utilization, it was concluded that for each input energy unit for canola, 2.9 energy units are produced, and considering only oil production this relationship decrease to 1:1.4. (author)

  1. Effect of pre-partum prilled fat supplementation on feed intake, energy balance and milk production in Murrah buffaloes

    Science.gov (United States)

    Sharma, Shikha; Singh, Mahendra; Roy, Ashwani Kumar; Thakur, Sunita

    2016-01-01

    Aim: To investigate the effect of pre-partum prilled fat feeding on dry matter intake (DMI), energy balance and milk production in Murrah buffaloes. Materials and Methods: Advance pregnant Murrah buffaloes were either received a dietary supplement of prilled fat at 100 g/day for 35 days pre-partum and at 150 g/day for 95 days post-partum (supplemented group [SG]) or did not receive fat supplement (control group [CG]). DMI and the yields of milk and milk component were measured. A body condition score (BCS) was recorded. Energy balance and gross feed efficiency (GFE) were calculated. DMI and BCS were recorded and milk yield (MY), fat, protein, lactose, solid not fat, energy balance were measured. The fat corrected milk yield was calculated. Results: The DMI was non-significant between groups and periods of study. BCS of buffaloes improved in the SG than CG (p<0.01). The energy intake in terms of total digestible nutrients (TDN%), TDN intake, digestible energy (DE), metabolizable energy/kg of milk, DE of milk, net energy, and GFE were higher (p<0.01) in SG during post-partum period. Crude protein intake was statistically similar in both the groups. MY was higher (p<0.01) in SG than in CG during 95 days of early lactation. Milk fat, fat corrected MY was higher (p<0.01) in SG however protein, lactose and solid not fat content did not varied between the groups. The feed efficiency of the SG was higher (p<0.01) than the CG during the post-partum period. Conclusion: It was inferred that prilled fat supplementation augments energy balance and milk production in transition Murrah buffaloes. PMID:27057108

  2. Effect of pre-partum prilled fat supplementation on feed intake, energy balance and milk production in Murrah buffaloes

    Directory of Open Access Journals (Sweden)

    Shikha Sharma

    2016-03-01

    Full Text Available Aim: To investigate the effect of pre-partum prilled fat feeding on dry matter intake (DMI, energy balance and milk production in Murrah buffaloes. Materials and Methods: Advance pregnant Murrah buffaloes were either received a dietary supplement of prilled fat at 100 g/day for 35 days pre-partum and at 150 g/day for 95 days post-partum (supplemented group [SG] or did not receive fat supplement (control group [CG]. DMI and the yields of milk and milk component were measured. A body condition score (BCS was recorded. Energy balance and gross feed efficiency (GFE were calculated. DMI and BCS were recorded and milk yield (MY, fat, protein, lactose, solid not fat, energy balance were measured. The fat corrected milk yield was calculated. Results: The DMI was non-significant between groups and periods of study. BCS of buffaloes improved in the SG than CG (p<0.01. The energy intake in terms of total digestible nutrients (TDN%, TDN intake, digestible energy (DE, metabolizable energy/kg of milk, DE of milk, net energy, and GFE were higher (p<0.01 in SG during post-partum period. Crude protein intake was statistically similar in both the groups. MY was higher (p<0.01 in SG than in CG during 95 days of early lactation. Milk fat, fat corrected MY was higher (p<0.01 in SG however protein, lactose and solid not fat content did not varied between the groups. The feed efficiency of the SG was higher (p<0.01 than the CG during the post-partum period. Conclusion: It was inferred that prilled fat supplementation augments energy balance and milk production in transition Murrah buffaloes.

  3. Sub-Balanced Energy Consumption through Engineered Gaussian Deployment Strategies in Corona-Based Wireless Sensor Network

    OpenAIRE

    Atiq-Ur-Rahman; Halabi Hasbullah; Najm-us-Sama

    2013-01-01

    Wireless sensor networks (WSNs) are getting more widespread use and can be used in a wide range of applications, such as environmental monitoring, smart homes, military surveillance, forests, habitat monitoring, farmlands and precision agriculture. Due to the limited battery power, energy efficiency is the most challenging problem in wireless sensor network. For various applications, it is necessary to deploy sensor node in efficient way to monitor the event precisely, achieve balance energy ...

  4. Sub-Balanced Energy Consumption through Engineered Gaussian Deployment Strategies in Corona-Based Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Atiq-Ur-Rahman

    2013-06-01

    Full Text Available Wireless sensor networks (WSNs are getting more widespread use and can be used in a wide range of applications, such as environmental monitoring, smart homes, military surveillance, forests, habitat monitoring, farmlands and precision agriculture. Due to the limited battery power, energy efficiency is the most challenging problem in wireless sensor network. For various applications, it is necessary to deploy sensor node in efficient way to monitor the event precisely, achieve balance energy depletion and extend the network lifetime. In many-to-one traffic pattern, nodes closer to the sink have heavier traffic loads and deplete their energy quickly; this leads to energy holes around the sink. Due to the creation of energy holes, data can no longer be delivered to the sink, although most of sensor nodes have enough residual energy. To overcome the problem of energy hole and achieving sub-balanced energy consumption in corona-based wireless sensor network, engineered Gaussian deployment strategies are proposed. Simulation result shows that the proposed technique maximizes the network lifetime, data delivery, energy consumption and also reducing the chances of energy-hole formation in a network.

  5. A simple water-energy balance framework to predict the sensitivity of streamflow to climate change

    Directory of Open Access Journals (Sweden)

    M. Renner

    2011-09-01

    Full Text Available Long term average change in streamflow is a major concern in hydrology and water resources management. Some simple analytical methods exist for the assessment of the sensitivity of streamflow to climatic variations. These are based on the Budyko hypothesis, which assumes that long term average streamflow can be predicted by climate conditions, namely by annual average precipitation and evaporative demand. Recently, Tomer and Schilling (2009 presented an ecohydrological concept to distinguish between effects of climate change and basin characteristics change on streamflow. We provide a theoretical foundation of this concept by showing that it is based on a coupled consideration of the water and energy balance. The concept uses a special condition that the sum of the ratio of annual actual evapotranspiration to precipitation and the ratio of actual to potential evapotranspiration is constant, even when climate conditions are changing.

    Here we apply this assumption and derive analytical solutions to the problem of streamflow sensitivity on climate. We show how climate sensitivity is influenced by different climatic conditions and the actual hydrological response of a basin. Finally, the properties and implications of the new method are compared with established Budyko sensitivity methods.

  6. Climate stability for a Sellers-type model. [atmospheric diffusive energy balance model

    Science.gov (United States)

    Ghil, M.

    1976-01-01

    We study a diffusive energy-balance climate model governed by a nonlinear parabolic partial differential equation. Three positive steady-state solutions of this equation are found; they correspond to three possible climates of our planet: an interglacial (nearly identical to the present climate), a glacial, and a completely ice-covered earth. We consider also models similar to the main one studied, and determine the number of their steady states. All the models have albedo continuously varying with latitude and temperature, and entirely diffusive horizontal heat transfer. The diffusion is taken to be nonlinear as well as linear. We investigate the stability under small perturbations of the main model's climates. A stability criterion is derived, and its application shows that the 'present climate' and the 'deep freeze' are stable, whereas the model's glacial is unstable. A variational principle is introduced to confirm the results of this stability analysis. For a sufficient decrease in solar radiation (about 2%) the glacial and interglacial solutions disappear, leaving the ice-covered earth as the only possible climate.

  7. Mass, energy, entropy and exergy rate balance in a ranque-hilsh vortex tube

    Directory of Open Access Journals (Sweden)

    Edorta Carrascal

    2013-12-01

    Full Text Available The purpose of this paper is to exhibit a laboratory practicum designed for the subject of Thermodynamics at the Department of Thermal Engineering of the University of the Basque Country. With reference to one of the problems stated in the text of Moran, Shapiro, Boettner, Bailey (2012, the balances of mass, energy, entropy and exergy are applied in a particular Control Volume, and the ideal gas model is used. Using a Ranque-Hilsh vortex tube (Ranque, 1934, the division of a compressed air flow into two streams at a lower pressure is achieved; one hot  whose temperature can exceed 100 °C and another cold that can reach temperatures below -40 °C. Therefore an air flow is divided into two, one hot and one cold stream, without any thermal interaction with hot or cold focuses. The vortex tube operation can serve to expose the bases of the first and second law of thermodynamics. Even, this practical lab can be used to give sense to one of the most known theoretical experiments in thermodynamics, such as the one of Maxwell's demon (Lewins & Bejan, 1999; Liew, Zeegers, Kuerten & Michalek, 2012. On the other hand once a compressed air source is provided, the material needed to prepare the lab is simple and affordable and it has a very interesting and suggestive appeal.

  8. Diffusive Heat Transport in Budyko's Energy Balance Climate Model with a Dynamic Ice Line

    CERN Document Server

    Walsh, James

    2016-01-01

    M. Budyko and W. Sellers independently introduced seminal energy balance climate models in 1969, each with a goal of investigating the role played by positive ice albedo feedback in climate dynamics. In this paper we replace the relaxation to the mean horizontal heat transport mechanism used in the models of Budyko and Sellers with diffusive heat transport. We couple the resulting surface temperature equation with an equation for movement of the edge of the ice sheet (called the ice line), recently introduced by E. Widiasih. We apply the spectral method to the temperature-ice line system and consider finite approximations. We prove there exists a stable equilibrium solution with a small ice cap, and an unstable equilibrium solution with a large ice cap, for a range of parameter values. If the diffusive transport is too efficient, however, the small ice cap disappears and an ice free Earth becomes a limiting state. In addition, we analyze a variant of the coupled diffusion equations appropriate as a model for ...

  9. Surface Energy Balance of Fresh and Saline Waters: AquaSEBS

    Directory of Open Access Journals (Sweden)

    Ahmed Abdelrady

    2016-07-01

    Full Text Available Current earth observation models do not take into account the influence of water salinity on the evaporation rate, even though the salinity influences the evaporation rate by affecting the density and latent heat of vaporization. In this paper, we adapt the SEBS (Surface Energy Balance System model for large water bodies and add the effect of water salinity to the evaporation rate. Firstly, SEBS is modified for fresh-water whereby new parameterizations of the water heat flux and sensible heat flux are suggested. This is achieved by adapting the roughness heights for momentum and heat transfer. Secondly, a salinity correction factor is integrated into the adapted model. Eddy covariance measurements over Lake IJsselmeer (The Netherlands are carried out and used to estimate the roughness heights for momentum (~0.0002 m and heat transfer (~0.0001 m. Application of these values over the Victoria and Tana lakes (freshwater in Africa showed that the calculated latent heat fluxes agree well with the measurements. The root mean-square of relative-errors (rRMSE is about 4.1% for Lake Victoria and 4.7%, for Lake Tana. Verification with ECMWF data showed that the salinity reduced the evaporation at varying levels by up to 27% in the Great Salt Lake and by 1% for open ocean. Our results show the importance of salinity to the evaporation rate and the suitability of the adapted-SEBS model (AquaSEBS for fresh and saline waters.

  10. Greenhouse gas balance of harvesting stumps and logging residues for energy in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, Eva-Lotta; Hansson, Per-Anders (Department of Energy and Technology, Swedish University of Agricultural Sciences, Uppsala (Sweden)), E-mail: eva-lotta.lindholm@slu.se; Stendahl, Johan (Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala (Sweden)); Berg, Staffan (Forestry Research Institute of Sweden, Uppsala Science Park, Uppsala (Sweden))

    2011-09-15

    In this case study, forest fuel procurement chains of stumps and logging residues were evaluated using a Life Cycle Assessment perspective. Direct emissions from combustion were not included, but soil organic carbon change was included as changes in carbon stocks in litter and soil. The results showed that primary forest biomass for energy has a climate impact which is time dependent. However, in long-time perspectives, there are large greenhouse gas (GHG) savings. In a short term (20 years), there were no GHG savings when natural gas or coal was replaced. This is due to the fact that the harvest lead to decreased input of organic matter to the soil which is compared to a reference where biomass are left to decompose. The reduction in soil organic carbon may have been underestimated in the stump harvest systems studied, as the effect of soil disturbance per se was not included. Important factors when assessing GHG balance of forest fuels, besides the time horizon used, were site productivity, geographical position and forest fuel resource (stumps or logging residues). When assessing the greenhouse gas savings, efficiency of the end-use, allocation method between heat and power and type of fossil fuel replaced were also important

  11. Evolution of desertification in a two-dimensional energy balance model coupled with thermodynamics and dynamics

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The relationship between desert evolution and change in albedo has been investigated quasi-analytically using a zonal mean two-dimensional energy balance model which considers the radiation transmission process due to thermodynamics and bound- ary layer movement caused by kinetics. A climate state including temperature, zonal wind, meridional wind and vertical wind can be simulated according to the current zonal distribution of albedo. Given desert distribution, characterized by the value and distribution of albedo, the response of climate on albedo has been studied to analyze the evolution of desert climate. One significant result is that the simple model can reproduce mean meridional circulation. Another result indicates that climate corresponds to two equilibria. This happens when the junction temperature between vegetation and desert is higher than a certain critical value. As for the first equilibrium, the desert belt is predicted to move southward in the northern hemisphere with the increasing values of albedo, which corresponds to the current trend of climate change. For the second equilibrium, vegetation will expand northward with increasing values of albedo, which would indicate a narrowing of the desert belt. In order to determine if the two equilibria exist, new physical models are needed.

  12. Computer Simulation of the Mass and Energy Balance during Gasification of Sugarcane Bagasse

    Directory of Open Access Journals (Sweden)

    Anthony Anukam

    2014-01-01

    Full Text Available This paper investigated the mass and energy balance of the gasification of sugarcane bagasse using computer simulation. The key parameters and gasifier operating conditions were investigated in order to establish their impact on gas volume and conversion efficiency of the gasification process. The heating value of sugarcane bagasse was measured and found to be 17.8 MJ/kg which was used during calculation of the conversion efficiency of the gasification process. Fuel properties and gasifier design parameters were found to have an impact on conversion efficiency of the gasification process of sugarcane bagasse. The moisture content of sugarcane bagasse was varied by 1.14%, 15%, and 25%, respectively. Optimum conversion efficiency was achieved at low moisture content (1.14% after computer simulation of the gasification process. The volume of carbon monoxide increased at low moisture content. It was also found that maximum conversion efficiency was achieved at reduced particle diameter (6 cm and at reduced throat diameter (10 cm and throat angle (25°, respectively, after these parameters were varied. Temperature of input air was also found to have an impact on the conversion efficiency of the gasification process as conversion efficiency increased slightly with increasing temperature of input air.

  13. Physical activity, sedentary behaviour and energy balance in the preschool child: opportunities for early obesity prevention.

    Science.gov (United States)

    Reilly, John J

    2008-08-01

    Prevalence of obesity in preschool children has increased dramatically in recent years. The preschool years (age 3-6 years) have been regarded as critical for the programming of energy balance, via the concept of early 'adiposity rebound'. Children who undergo early adiposity rebound are at increased risk of later obesity. Recent evidence suggests that associations between timing of adiposity rebound and later obesity may not reflect programming, but might denote that 'obesogenic' growth trajectories are often established by the preschool period. Studies of objectively-measured physical activity and sedentary behaviour in preschool children show that levels of physical activity are typically low and sedentary behaviour high. The review of evidence presented here is supportive of the hypothesis that physical activity is protective against obesity in the preschool period, and that sedentary behaviour, particularly television viewing, is obesogenic. Definitive evidence on dose-response relationships between physical activity, sedentary behaviour and obesity remain unclear. Dose-response evidence could be obtained fairly readily by intervention and longitudinal observational studies that use accelerometry in preschool children. The generalisability of much of the evidence base is limited and there is a need for research on the influence of physical activity and sedentary behaviour in the preschool years in the aetiology of obesity in the developing world.

  14. Large and small-scale structures and the dust energy balance problem in spiral galaxies

    CERN Document Server

    Saftly, W; De Geyter, G; Camps, P; Renaud, F; Guedes, J; De Looze, I

    2015-01-01

    The interstellar dust content in galaxies can be traced in extinction at optical wavelengths, or in emission in the far-infrared. Several studies have found that radiative transfer models that successfully explain the optical extinction in edge-on spiral galaxies generally underestimate the observed FIR/submm fluxes by a factor of about three. In order to investigate this so-called dust energy balance problem, we use two Milky Way-like galaxies produced by high-resolution hydrodynamical simulations. We create mock optical edge-on views of these simulated galaxies (using the radiative transfer code SKIRT), and we then fit the parameters of a basic spiral galaxy model to these images (using the fitting code FitSKIRT). The basic model includes smooth axisymmetric distributions along a S\\'ersic bulge and exponential disc for the stars, and a second exponential disc for the dust. We find that the dust mass recovered by the fitted models is about three times smaller than the known dust mass of the hydrodynamical in...

  15. Negative energy balance affects imprint stability in oocytes recovered from postpartum dairy cows.

    Science.gov (United States)

    O'Doherty, Alan M; O'Gorman, Aoife; al Naib, Abdullah; Brennan, Lorraine; Daly, Edward; Duffy, Pat; Fair, Trudee

    2014-09-01

    Ovarian follicle development in post-partum, high-producing dairy cows, occurs in a compromised endogenous metabolic environment (referred to as negative energy balance, NEB). Key events that occur during oocyte/follicle growth, such as the vital process of genomic imprinting, may be detrimentally affected by this altered ovarian environment. Imprinting is crucial for placental function and regulation of fetal growth, therefore failure to establish and maintain imprints during oocyte growth may contribute to early embryonic loss. Using ovum pick-up (OPU), oocytes and follicular fluid samples were recovered from cows between days 20 and 115 post-calving, encompassing the NEB period. In a complimentary study, cumulus oocyte complexes were in vitro matured under high non-esterified fatty acid (NEFA) concentrations and in the presence of the methyl-donor S-adenosylmethionine (SAM). Pyrosequencing revealed the loss of methylation at several imprinted loci in the OPU derived oocytes. The loss of DNA methylation was observed at the PLAGL1 locus in oocytes, following in vitro maturation (IVM) in the presence of elevated NEFAs and SAM. Finally, metabolomic analysis of postpartum follicular fluid samples revealed significant differences in several branched chain amino acids, with fatty acid profiles bearing similarities to those characteristic of lactating dairy cows. These results provide the first evidence that (1) the postpartum ovarian environment may affect maternal imprint acquisition and (2) elevated NEFAs during IVM can lead to the loss of imprinted gene methylation in bovine oocytes.

  16. Estimation of components of energy balance on drifting ice over Arctic Ocean

    Institute of Scientific and Technical Information of China (English)

    卞林根; 陆龙骅; 高志球; 程彦杰; 逯昌贵; 李诗明

    2001-01-01

    Estimation and simulation were carried out for the components of ice-surface energy balance and tur bulent exchange parameters using the flux-profile method and the sinple biosphere model version 2 (SiB2, hereinafter) respectively based on the measured results for the atmosphere in the near-ice-surface layer, which were observed by the First Arctic Scientific Expedition of China in August, 1999 at a joint ice-research station (75°02′N, 160°51′W) on the drifting ice of Arctic Ocean. Evidence suggests that during the melting period of drifting ice the sum of the ice-released sensible heat and effective melting-consumed heat is greater than the net ice-absorbed radiation on the surface, with the excess heat coming via heat conduction from the deep layers of the ice mass. The simulated net radiation is systematical lv 18% greater than the measured results, while the simulated sensible heat flux is systematically 3% lower than the measured ones; and the simulated ice-surface heat flux differs noticeably from its calculation. Hence, we see that al though the measured sequences are short, the simulations of net radiation and sensible heat fluxes by the SiB2 model are comparatively good, the simulation of other forms of fluxes still needs to be improved.

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

    Directory of Open Access Journals (Sweden)

    A. Alessandri

    2012-07-01

    Full Text Available Future climate scenarios experiencing global warming are expected to strengthen hydrological cycle during 21st century by comparison with the last decades of 20th century. We analyze strengthening of the global-scale increase in precipitation from the perspective of changes in whole atmospheric water and energy balances. Furthermore, by combining energy and water equations for the whole atmosphere we profitably obtain constraints for the changes in surface fluxes and for the partitioning at the surface between sensible and latent components.

    Above approach is applied to investigate difference in strengthening of hydrological cycle in two scenario centennial simulations performed with an Earth System model forced with specified atmospheric concentration pathways. Alongside the medium-high non-mitigation scenario SRES A1B, we considered a new aggressive-mitigation scenario (E1 with reduced fossil fuel use for energy production aimed at stabilizing global warming below 2 K. Quite unexpectedly, mitigation scenario is shown to strengthen hydrological cycle more than SRES A1B till around 2070. Our analysis shows that this is mostly a consequence of the larger increase in the negative radiative imbalance of atmosphere in E1 compared to A1B. This appears to be primarily related to the abated aerosol concentration in E1, which considerably reduces atmospheric absorption of solar radiation compared to A1B.

    In contrast, last decades of 21st century (21C show marked increase of global precipitation in A1B compared to E1, despite the fact that the two scenarios display almost same overall increase of radiative imbalance with respect to 20th century. Our results show that radiative cooling is weakly effective in A1B throughout all 21C, so that two distinct mechanisms characterize the diverse strengthening of hydrological cycle in mid and end 21C. It is only through a very large perturbation of surface fluxes that A1B achieves larger increase

  18. Adipocytokines and Energy Balance%脂肪细胞因子与能量平衡

    Institute of Scientific and Technical Information of China (English)

    肖刚

    2015-01-01

    脂肪细胞因子由脂肪组织分泌,控制多个生理系统。空腹期间,瘦素水平降低,刺激食欲,降低能量消耗,调节神经内分泌和免疫功能,增加能量储备。相反,处于过饱状态、瘦素水平会升高,通过抑制食欲、增加能量消耗,来防止体重增加。这些行为活动由下丘脑和脑干介导完成。瘦素也可通过靶向作用于肝脏和肌肉中的酶,如AMP-活化蛋白激酶和硬脂酰CoA去饱和酶-1,来控制糖和脂质代谢。同样,脂联素和抵抗素通过中枢和周围靶点控制能量平衡和胰岛素敏感性。这是脂肪因子特殊而又共同的信号途径。了解脑和其它器官中脂肪因子信号有助于分析肥胖、糖尿病等多种疾病的病理变化过程并做出积极预防。%Adipokines secreted by adipose tissue, control multiple physiological systems. During fasting, lower leptin levels stimulate the appetite, reduce energy consumption, regulate neuroendocrine and immune function and increase energy reserves. On the contrary, in the fullness state, leptin levels will rise, by suppressing appetite, increase energy consumption, to prevent weight gain. These behavioral activities are done by the hypothalamus and brainstem-mediated. Leptin can also be targeting the liver and muscle enzymes, such as AMP-activated protein kinase and stearoyl-CoA desaturase-1, to control glucose and lipid metabolism. Similarly, adiponectin and resistin controlled energy balance and insulin sensitivity by the central and peripheral tar-gets. This is the special and common signaling pathways of adipokines. Understanding the adipokines signal in the brain and other organs helps to analyze obesity, pathological changes of diabetes and other diseases and to make positive prevention.

  19. Aedes aegypti Global Suitability Maps Using a Water Container Energy Balance Model for Dengue Risk Applications

    Science.gov (United States)

    Steinhoff, D.

    2015-12-01

    Dengue infections are estimated to total nearly 400 million per year worldwide, with both the geographic range and the magnitude of infections having increased in the past 50 years. The primary dengue vector mosquito Aedes aegypti is closely associated with humans. It lives exclusively in urban and semi-urban areas, preferentially bites humans, and spends its developmental stages in artificial water containers. Climate regulates the development of Ae. aegypti immature mosquitoes in artificial containers. Potential containers for Ae. aegypti immature development include, but are not limited to, small sundry items (e.g., bottles, cans, plastic containers), buckets, tires, barrels, tanks, and cisterns. Successful development of immature mosquitoes from eggs to larvae, pupae, and eventually adults is largely dependent on the availability of water and the thermal properties of the water in the containers. Recent work has shown that physics-based approaches toward modeling container water properties are promising for resolving the complexities of container water dynamics and the effects on immature mosquito development. An energy balance container model developed by the author, termed the Water Height And Temperature in Container Habitats Energy Model (WHATCH'EM), solves for water temperature and height for user-specified containers with readily available weather data. Here we use WHATCH'EM with NASA Earth Science products used as input to construct global suitability maps based on established water temperature ranges for immature Ae. aegypti mosquitoes. A proxy for dengue risk is provided from habitat suitability, but also population estimates, as Ae. aegypti is closely associated with human activity. NASA gridded Global Population of the World data is used to mask out rural areas with low dengue risk. Suitability maps are illustrated for a variety of containers (size, material, color) and shading scenarios.

  20. An efficient regional energy-moisture balance model for simulation of the Greenland Ice Sheet response to climate change

    Directory of Open Access Journals (Sweden)

    A. Robinson

    2010-04-01

    Full Text Available In order to explore the response of the Greenland ice sheet (GIS to climate change on long (centennial to multi-millennial time scales, a regional energy-moisture balance model has been developed. This model simulates seasonal variations of temperature and precipitation over Greenland and explicitly accounts for elevation and albedo feedbacks. From these fields, the annual mean surface temperature and surface mass balance can be determined and used to force an ice sheet model. The melt component of the surface mass balance is computed here using both a positive degree day approach and a more physically-based alternative that includes insolation and albedo explicitly. As a validation of the climate model, we first simulated temperature and precipitation over Greenland for the prescribed, present-day topography. Our simulated climatology compares well to observations and does not differ significantly from that of a simple parameterization used in many previous simulations. Furthermore, the calculated surface mass balance using both melt schemes falls within the range of recent regional climate model results. For a prescribed, ice-free state, the differences in simulated climatology between the regional energy-moisture balance model and the simple parameterization become significant, with our model showing much stronger summer warming. When coupled to a three-dimensional ice sheet model and initialized with present-day conditions, the two melt schemes both allow realistic simulations of the present-day GIS.

  1. Energy Balance Alterations Due to Cropland Conversion in a Tropical Montane Environment: Shaded Coffee to Sugarcane

    Science.gov (United States)

    Alvarado-Barrientos, M. S.; Holwerda, F.; Salazar-Martinez, D.

    2014-12-01

    Although land use change (LUC) is an important driver of changes in climate, very limited field observations of atmosphere-landscape interactions exist in tropical montane zones to examine the extent to which LUCs affect climate locally and regionally. The lack of ground observations hampers the evaluation of satellite-derived datasets of land surface parameters as well as the validation of regional climate models. The first results of an ongoing study of the climate effects of a LUC trajectory in the lower montane region (1200 m a.s.l.) of central Veracruz, Mexico, are presented. The radiation balance, turbulent fluxes and soil heat flux were measured in order to obtain field-derived land surface parameters (albedo and Bowen ratio) of two contrasting land uses: shaded coffee (CO) and sugarcane (SU) plantations. Measurements were conducted on days representing different seasons and crop stages during 2014: cold-dry (January), warm-dry (March) and warm-wet (July). Average noon-time albedo was higher for SU than for CO (0.14 vs. 0.11). Soil heat flux was on average 13% and 12% of net radiation for SU and CO, respectively. Preliminary turbulent flux calculations indicate that noon-time Bowen ratio was higher for sugar cane (range: 1.0-1.5) compared to shaded coffee (range: 0.5-1.0). Seasonal (and crop-stage) changes affected the surface parameters of SU mostly. For example, the SU Bowen ratio increased with decreasing soil moisture, indicating soil moisture limitation for transpiration reducing latent heat flux. In contrast, the shaded coffee Bowen ratio remained relatively constant across measuring periods. The energy balance closure was 80% (pending complete eddy covariance data corrections). These results indicate that the conversion of shaded coffee to sugarcane result in a drier and hotter lower atmosphere. Next steps include examining the implications of these local changes for regional climate, with special attention to cloud formation, using a regional model

  2. Vegetation water stress monitoring with remote sensing-based energy balance modelling

    Science.gov (United States)

    González-Dugo, Maria P.; Andreu, Ana; Carpintero, Elisabet; Gómez-Giráldez, Pedro; José Polo, María

    2014-05-01

    Drought is one of the major hazards faced by agroforestry systems in southern Europe, and an increase in frequency is predicted under the conditions of climate change for the region. Timely and accurate monitoring of vegetation water stress using remote sensing time series may assist early-warning services, helping to assess drought impacts and the design of management actions leading to reduce the economic and environmental vulnerability of these systems. A holm oak savanna, known as dehesa in Spain and montado in Portugal, is an agro-silvo-pastoral system occupying more than 3 million hectares the Iberian Peninsula and Greece. It consists of widely-spaced oak trees (mostly Quercus ilex L.), combined with crops, pasture and Mediterranean shrubs, and it is considered an example of sustainable land use, with great importance in the rural economy. Soil water dynamics is known to have a central role in current tree decline and the reduction of the forested area that is threatening its conservation. A two-source thermal-based evapotranspiration model (TSEB) has been applied to monitor the effect on vegetation water use of soil moisture stress in a dehesa located in southern Spain. The TSEB model separates the soil and canopy contributions to the radiative temperature and to the exchange of surface energy fluxes, so it is especially suited for partially vegetated landscapes. The integration of remotely sensed data in this model may support an evaluation of the whole ecosystem state at a large scale. During two consecutive summers, in 2012 and 2013, time series of optical and thermal MODIS images, with 250m and 1 km of spatial resolution respectively, have been combined with meteorological data provided by a ground station to monitor the evapotranspiration (ET) of the system. An eddy covariance tower (38°12' N; 4°17' W, 736 m a.s.l), equipped with instruments to measure all the components of the energy balance and 1 km of homogeneous fetch in the predominant wind

  3. Monitoring Evaporation/Transpiration in a Vineyard from Two-Source Energy Balance and Radiometric Temperatures

    Science.gov (United States)

    Sánchez, Juan Manuel; Doña, Carolina; Cuxart, Joan; Caselles, Vicente; Niclòs, Raquel

    2014-05-01

    Water management and understanding of irrigation efficiency could be significantly improved if the components of evapotranspiration (ET) in row-crop systems (plants and soil interrows) could be quantified separately. This evaporation/transpiration (E/T) partition, and its daily and seasonal evolution, depends on a variety of biophysical and environmental factors. In this work we present an operational method to provide continuous E/T results avoiding soil or canopy disturbance. This technique is based on the combination of the surface-atmosphere energy exchange modeling together with an accurate remote thermal characterization of the crop elements. An experiment was carried out in a row-crop vineyard in Mallorca, Spain, from June 2012 to May 2013. A set of 6 thermal-infrared radiometers (IRTs) were mounted in a mast placed in the middle of a vineyard N-S row. Two IRTs pointed to the soil between rows and other two pointed to the plants from a frontal view, measuring both east and west sides of the row. A fifth IRT pointed upward to collect the downwelling sky radiance and the remaining IRT was mounted at 4.5-m height over the canopy measuring the composed soil-canopy temperature. Measurements of the four components of the net radiation over the canopy and soil heat fluxes, as well as air temperature, humidity, wind speed, and soil moisture, were collected and stored in 15-min averages. A two-source energy balance approach was applied to the vineyard from its appropriate thermal characterization. Total and separate soil/canopy components of net radiation, soil, sensible and latent heat fluxes were obtained every 15 minutes and averaged at hourly and daily scales. Comparison between observed and modeled values of available surface energy showed relative errors below 15%. An analysis of the partition E/T was conducted along the vineyard growing season and the different phenological stages. In this experiment, interrow soil evaporation reached as much as 1/3 of the

  4. Heat storage in forest biomass significantly improves energy balance closure particularly during stable conditions

    Directory of Open Access Journals (Sweden)

    A. Lindroth

    2009-08-01

    Full Text Available Temperature measurements in trunks and branches in a mature ca. 100 years-old mixed pine and spruce forest in central Sweden were used to estimate the heat storage in the tree biomass. The estimated heat flux in the sample trees and data on biomass distributions were used to scale up to stand level biomass heat fluxes. The rate of change of sensible and latent heat storage in the air layer below the level of the flux measurements was estimated from air temperature and humidity profile measurements and soil heat flux was estimated from heat flux plates and soil temperature measurements. The fluxes of sensible and latent heat from the forest were measured with an eddy covariance system in a tower. The analysis was made for a two-month period in summer of 1995. The tree biomass heat flux was the largest of the estimated storage components and varied between 40 and −35 W m−2 on summer days with nice weather. Averaged over two months the diurnal maximum of total heat storage was 45 W m−2 and the minimum was −35 W m−2. The soil heat flux and the sensible heat storage in air were out of phase with the biomass flux and they reached maximum values that were about 75% of the maximum of the tree biomass heat storage. The energy balance closure improved significantly when the total heat storage was added to the turbulent fluxes. The slope of a regression line with sum of fluxes and storage as independent and net radiation as dependent variable, increased from 0.86 to 0.95 for half-hourly data and the scatter was also reduced. The most significant finding was, however, that during nights with strongly stable conditions when the sensible heat flux dropped to nearly zero, the total storage matched the net radiation nearly perfectly. Another interesting result was that the mean energy imbalance started to increase when the Richardson number became more negative than ca. −0.1. In fact, the largest energy deficit

  5. Mass, energy and material balances of SRF production process. Part 1: SRF produced from commercial and industrial waste.

    Science.gov (United States)

    Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne

    2014-08-01

    This paper presents the mass, energy and material balances of a solid recovered fuel (SRF) production process. The SRF is produced from commercial and industrial waste (C&IW) through mechanical treatment (MT). In this work various streams of material produced in SRF production process are analyzed for their proximate and ultimate analysis. Based on this analysis and composition of process streams their mass, energy and material balances are established for SRF production process. Here mass balance describes the overall mass flow of input waste material in the various output streams, whereas material balance describes the mass flow of components of input waste stream (such as paper and cardboard, wood, plastic (soft), plastic (hard), textile and rubber) in the various output streams of SRF production process. A commercial scale experimental campaign was conducted on an MT waste sorting plant to produce SRF from C&IW. All the process streams (input and output) produced in this MT plant were sampled and treated according to the CEN standard methods for SRF: EN 15442 and EN 15443. The results from the mass balance of SRF production process showed that of the total input C&IW material to MT waste sorting plant, 62% was recovered in the form of SRF, 4% as ferrous metal, 1% as non-ferrous metal and 21% was sorted out as reject material, 11.6% as fine fraction, and 0.4% as heavy fraction. The energy flow balance in various process streams of this SRF production process showed that of the total input energy content of C&IW to MT plant, 75% energy was recovered in the form of SRF, 20% belonged to the reject material stream and rest 5% belonged with the streams of fine fraction and heavy fraction. In the material balances, mass fractions of plastic (soft), plastic (hard), paper and cardboard and wood recovered in the SRF stream were 88%, 70%, 72% and 60% respectively of their input masses to MT plant. A high mass fraction of plastic (PVC), rubber material and non

  6. Permafrost and surface energy balance of a polygonal tundra site in northern Siberia – Part 1: Spring to fall

    Directory of Open Access Journals (Sweden)

    M. Langer

    2010-07-01

    Full Text Available Permafrost thawing is essentially determined by the surface energy balance, which potentially triggers the activation of a massive carbon source, if previously frozen organic soils are exposed to microbial decomposition. In this article, we present the first part of a comprehensive annual surface energy balance study performed at a polygonal tundra landscape in northeast Siberia, realized between spring 2007 and winter 2009. This part of the study focuses on the half year period from April to September 2007–2008, during which the surface energy balance is obtained from independent measurements of the radiation budget, the turbulent heat fluxes and the ground heat flux at several sites. The short-wave radiation is the dominant factor in the surface energy balance during the entire observation period. About 50% of the available net radiation is consumed by latent heat flux, while the sensible and the ground heat flux are both on the order of 20 to 30%. The ground heat flux is mainly consumed by active layer thawing, where 60% of soil energy storage are attributed to. The remainder is used for soil warming down to a depth of 15 m. The controlling factors for the surface energy partitioning are in particular the snow cover, the cloud cover and the soil temperature gradient. Significant surface temperature differences of the heterogeneous landscape indicate spatial variabilities of sensible and latent heat fluxes, which are verified by measurements at different locations. However, differences in the partition between sensible and latent heat flux for the different sites only exist during conditions of high radiative forcing, which only occur occasionally.

  7. DET/MPS - THE GSFC ENERGY BALANCE PROGRAM, DIRECT ENERGY TRANSFER/MULTIMISSION SPACECRAFT MODULAR POWER SYSTEM (UNIX VERSION)

    Science.gov (United States)

    Jagielski, J. M.

    1994-01-01

    The DET/MPS programs model and simulate the Direct Energy Transfer and Multimission Spacecraft Modular Power System in order to aid both in design and in analysis of orbital energy balance. Typically, the DET power system has the solar array directly to the spacecraft bus, and the central building block of MPS is the Standard Power Regulator Unit. DET/MPS allows a minute-by-minute simulation of the power system's performance as it responds to various orbital parameters, focusing its output on solar array output and battery characteristics. While this package is limited in terms of orbital mechanics, it is sufficient to calculate eclipse and solar array data for circular or non-circular orbits. DET/MPS can be adjusted to run one or sequential orbits up to about one week, simulated time. These programs have been used on a variety of Goddard Space Flight Center spacecraft projects. DET/MPS is written in FORTRAN 77 with some VAX-type extensions. Any FORTRAN 77 compiler that includes VAX extensions should be able to compile and run the program with little or no modifications. The compiler must at least support free-form (or tab-delineated) source format and 'do do-while end-do' control structures. DET/MPS is available for three platforms: GSC-13374, for DEC VAX series computers running VMS, is available in DEC VAX Backup format on a 9-track 1600 BPI tape (standard distribution) or TK50 tape cartridge; GSC-13443, for UNIX-based computers, is available on a .25 inch streaming magnetic tape cartridge in UNIX tar format; and GSC-13444, for Macintosh computers running AU/X with either the NKR FORTRAN or AbSoft MacFORTRAN II compilers, is available on a 3.5 inch 800K Macintosh format diskette. Source code and test data are supplied. The UNIX version of DET requires 90K of main memory for execution. DET/MPS was developed in 1990. A/UX and Macintosh are registered trademarks of Apple Computer, Inc. VMS, DEC VAX and TK50 are trademarks of Digital Equipment Corporation. UNIX is a

  8. Norwegian power and energy balance towards the year of 2010; Norges effekt- og energibalanse frem mot aar 2010

    Energy Technology Data Exchange (ETDEWEB)

    Loekke, K.

    1996-12-31

    The present conference paper deals with the Norwegian power and energy balance towards the year of 2010 based on the rate of domestic energy consumption, development of new power plants, and international supply agreements. The efficiency of power transmission compared to the level of delivered energy in the Norwegian power grid within the period from 1975 to 1992 has increased from 83% to 91% with an equivalency of 5.5 TWh. Aspects in connection with the long-range programme are discussed. 12 figs.

  9. Effects of live weight adjusted feeding strategy on plasma indicators of energy balance in Holstein cows managed for extended lactation.

    Science.gov (United States)

    Gaillard, C; Vestergaard, M; Weisbjerg, M R; Sehested, J

    2016-04-01

    In early lactation, most of the dairy cows are in negative energy balance; the extent and duration depend in part on the feeding strategy. Previous studies showed an increased lactation milk yield by use of a live weight (LW) adjusted feeding strategy with a high energy diet before and a reduced energy diet after LW nadir compared with a standard diet throughout lactation. The objective of the present study was to examine how such an individualized feeding strategy affects plasma indicators of energy status. It was hypothesized that an energy-enriched diet until LW nadir will reduce the severity of the negative energy balance, and that the reduction in diet energy concentration from LW nadir will extend the negative energy balance period further. Sixty-two Holstein cows (30% first parity) were managed for 16 months extended lactation and randomly allocated to one of two feeding strategies at calving. Two partially mixed rations were used, one with a high energy density (HD) and a 50 : 50 forage : concentrate ratio, and one with a lower energy density (LD, control diet) and a 60 : 40 forage : concentrate ratio. Half of the cows were offered the HD diet until they reached at least 42 days in milk and a LW gain⩾0 kg/day based on a 5-days LW average, and were then shifted to the LD diet (strategy HD-LD). The other half of the cows were offered the LD diet throughout lactation (control strategy LD-LD). Weekly blood samples were drawn for analysis of plasma metabolites and hormones. Before the shift in diet, the HD-LD cows had higher glucose and lower beta-hydroxybutyrate and non-esterified fatty acids (NEFA) concentrations than the LD-LD cows. After the shift until 36 weeks after calving, plasma NEFA was higher in HD-LD than LD-LD cows. Insulin and insulin-like growth factor-1 were not affected by the feeding strategy. To conclude, in early lactation, the energy-enriched diet reduced the negative energy balance. Plasma NEFA was higher in HD-LD than LD-LD cows from

  10. Genetics of grass dry matter intake, energy balance, and digestibility in grazing irish dairy cows.

    Science.gov (United States)

    Berry, D P; Horan, B; O'Donovan, M; Buckley, F; Kennedy, E; McEvoy, M; Dillon, P

    2007-10-01

    The objective of this study was to estimate genetic parameters for grass dry matter intake (DMI), energy balance (EB), and cow internal digestibility (IDG) in grazing Holstein-Friesian dairy cows. Grass DMI was estimated up to 4 times per lactation on 1,588 lactations from 755 cows on 2 research farms in southern Ireland. Simultaneously measured milk production and BW records were used to calculate EB. Cow IDG, measured as the ratio of feed and fecal concentrations of the natural odd carbon-chain n-alkane pentatriacontane, was available on 583 lactations from 238 cows. Random regression and multitrait animal models were used to estimate residual, additive genetic and permanent environmental (co)variances across lactations. Results were similar for both models. Heritability for DMI, EB, and IDG across lactation varied from 0.10 [8 days in milk (DIM)] to 0.30 (169 DIM), from 0.06 (29 DIM) to 0.29 (305 DIM), and from 0.08 (50 DIM) to 0.45 (305 DIM), respectively, when estimated using the random regression model. Genetic correlations within each trait tended to decrease as the interval between periods compared increased for DMI and EB, whereas the correlations with IDG in early lactation were weakest when measured midlactation. The lowest correlation between any 2 periods was 0.10, -0.36, and -0.04 for DMI, EB, and IDG, respectively, suggesting the effect of different genes at different stages of lactations. Eigenvalues and associated eigenfunctions of the additive genetic covariance matrix revealed considerable genetic variation among animals in the shape of the lactation profiles for DMI, EB, and IDG. Genetic parameters presented are the first estimates from dairy cows fed predominantly grazed grass and imply that genetic improvement in DMI, EB, and IDG in Holstein-Friesian cows fed predominantly grazed grass is possible.

  11. The emerging role of the endocannabinoid system in endocrine regulation and energy balance.

    Science.gov (United States)

    Pagotto, Uberto; Marsicano, Giovanni; Cota, Daniela; Lutz, Beat; Pasquali, Renato

    2006-02-01

    During the last few years, the endocannabinoid system has emerged as a highly relevant topic in the scientific community. Many different regulatory actions have been attributed to endocannabinoids, and their involvement in several pathophysiological conditions is under intense scrutiny. Cannabinoid receptors, named CB1 receptor and CB2 receptor, first discovered as the molecular targets of the psychotropic component of the plant Cannabis sativa, participate in the physiological modulation of many central and peripheral functions. CB2 receptor is mainly expressed in immune cells, whereas CB1 receptor is the most abundant G protein-coupled receptor expressed in the brain. CB1 receptor is expressed in the hypothalamus and the pituitary gland, and its activation is known to modulate all the endocrine hypothalamic-peripheral endocrine axes. An increasing amount of data highlights the role of the system in the stress response by influencing the hypothalamic-pituitary-adrenal axis and in the control of reproduction by modifying gonadotropin release, fertility, and sexual behavior. The ability of the endocannabinoid system to control appetite, food intake, and energy balance has recently received great attention, particularly in the light of the different modes of action underlying these functions. The endocannabinoid system modulates rewarding properties of food by acting at specific mesolimbic areas in the brain. In the hypothalamus, CB1 receptor and endocannabinoids are integrated components of the networks controlling appetite and food intake. Interestingly, the endocannabinoid system was recently shown to control metabolic functions by acting on peripheral tissues, such as adipocytes, hepatocytes, the gastrointestinal tract, and, possibly, skeletal muscle. The relevance of the system is further strenghtened by the notion that drugs interfering with the activity of the endocannabinoid system are considered as promising candidates for the treatment of various diseases

  12. Energy Balance Feasibility Study for Latinas in Texas: A Qualitative Assessment

    Directory of Open Access Journals (Sweden)

    Amelie G. Ramirez, DrPH

    2007-10-01

    Full Text Available IntroductionObesity has reached epidemic levels, with nearly two-thirds of the U.S. population considered overweight or obese. Latinos have some of the highest rates of overweight, obesity, and sedentary lifestyle. Research from scientifically sound evidence-based interventions to reduce the disproportionate burden of obesity and its associated morbidity and mortality among Latinas is greatly needed. The purpose of this study was to assess knowledge, attitudes, and behaviors about nutrition and exercise among Latinas aged 40 years and older residing in a low-income community in Houston, Texas, and the applicability of an evidence-based church program to promote healthy energy balance.MethodsQualitative assessment was conducted through 10 focus groups with 75 women recruited through three Catholic churches, community groups, and leaders.ResultsParticipants identified barriers and enabling factors to healthy nutrition and physical activity. Barriers included lack of awareness about nutrition and physical activity, cultural beliefs, and socioeconomic and environmental factors. Preferred strategies were group activities with direct guidance from qualified individuals and interpersonal contact among participants, social support with positive reinforcement for behavior change or maintenance, and a friendly environment for learning and achieving suitable goals. The church was considered a powerful resource to influence Latinas to improve their health, exercise, and nutrition practices.ConclusionOur findings suggest that using the church environment to reach Latina women aged 40 years and older is a feasible and culturally appropriate strategy. The church environment provides a safe, comfortable, and familiar atmosphere for women and addresses specific cultural barriers and safety concerns of family members.

  13. Adipose tissue development during early life: novel insights into energy balance from small and large mammals.

    Science.gov (United States)

    Symonds, Michael E; Pope, Mark; Budge, Helen

    2012-08-01

    Since the rediscovery of brown adipose tissue (BAT) in adult human subjects in 2007, there has been a dramatic resurgence in research interest in its role in heat production and energy balance. This has coincided with a reassessment of the origins of BAT and the suggestion that brown preadipocytes could share a common lineage with skeletal myoblasts. In precocial newborns, such as sheep, the onset of non-shivering thermogenesis through activation of the BAT-specific uncoupling protein 1 (UCP1) is essential for effective adaptation to the cold exposure of the extra-uterine environment. This is mediated by a combination of endocrine adaptations which accompany normal parturition at birth and further endocrine stimulation from the mother's milk. Three distinct adipose depots have been identified in all species studied to date. These contain either primarily white, primarily brown or a mix of brown and white adipocytes. The latter tissue type is present, at least, in the fetus and, thereafter, appears to take on the characteristics of white adipose tissue during postnatal development. It is becoming apparent that a range of organ-specific mechanisms can promote UCP1 expression. They include the liver, heart and skeletal muscle, and involve unique endocrine systems that are stimulated by cold exposure and/or exercise. These multiple pathways that promote BAT function vary with age and between species that may determine the potential to be manipulated in early life. Such interventions could modify, or reverse, the normal ontogenic pathway by which BAT disappears after birth, thereby facilitating BAT thermogenesis through the life cycle.

  14. Age and nutritional state influence the effects of cholecystokinin on energy balance.

    Science.gov (United States)

    Balaskó, M; Rostás, I; Füredi, N; Mikó, A; Tenk, J; Cséplő, P; Koncsecskó-Gáspár, M; Soós, S; Székely, M; Pétervári, E

    2013-11-01

    Cholecystokinin (CCK) is anorexic, irrespective whether it is applied intraperitoneally (IP) or intracerebroventricularly (ICV) in male Wistar rats. The metabolic effects depend on the route of administration: by the IP route it elicits hypothermia (presumably by type-1 receptors, CCK1R-s), while ICV administration is followed by fever-like hypermetabolism and hyperthermia via activation of CCK2R-s, which latter response seems to be most important in the postprandial (compensatory) hypermetabolism. The efficacy of the IP injected CCK varies with age: it causes strong anorexia in young adult 4 and 6-months old and again in old rats (aged 18-24 months), but the middle-aged (12-month old) ones seem to be resistant to this effect. Such pattern of effects may contribute to the explanation of age-related obesity observed in middle-aged animals as well as to the aging anorexia and loss of body weight in old ones. Diet-induced obesity accelerates the appearance of CCK-resistance as well as the return of high sensitivity to CCK in further aging, while chronic calorie-restriction prevents the development of resistance, as if the speed of the age-related regulatory changes was altered by the nutritional state. The effects of ICV applied CCK also change with age: the characteristic anorexic and hypermetabolic/hyperthermic effects can be observed in young adult rats, but the effects gradually and monotonically decline with age and disappear by the old age of 24 months. These disparate age-related patterns of CCK efficacy upon peripheral or central administration routes may indicate that although both peripheral and central CCKR-s exert anorexic effects, they may have dissimilar roles in the regulation of overall energy balance.

  15. Impact of Sleep and Circadian Disruption on Energy Balance and Diabetes: A Summary of Workshop Discussions.

    Science.gov (United States)

    Arble, Deanna M; Bass, Joseph; Behn, Cecilia Diniz; Butler, Matthew P; Challet, Etienne; Czeisler, Charles; Depner, Christopher M; Elmquist, Joel; Franken, Paul; Grandner, Michael A; Hanlon, Erin C; Keene, Alex C; Joyner, Michael J; Karatsoreos, Ilia; Kern, Philip A; Klein, Samuel; Morris, Christopher J; Pack, Allan I; Panda, Satchidananda; Ptacek, Louis J; Punjabi, Naresh M; Sassone-Corsi, Paolo; Scheer, Frank A; Saxena, Richa; Seaquest, Elizabeth R; Thimgan, Matthew S; Van Cauter, Eve; Wright, Kenneth P

    2015-12-01

    A workshop was held at the National Institute for Diabetes and Digestive and Kidney Diseases with a focus on the impact of sleep and circadian disruption on energy balance and diabetes. The workshop identified a number of key principles for research in this area and a number of specific opportunities. Studies in this area would be facilitated by active collaboration between investigators in sleep/circadian research and investigators in metabolism/diabetes. There is a need to translate the elegant findings from basic research into improving the metabolic health of the American public. There is also a need for investigators studying the impact of sleep/circadian disruption in humans to move beyond measurements of insulin and glucose and conduct more in-depth phenotyping. There is also a need for the assessments of sleep and circadian rhythms as well as assessments for sleep-disordered breathing to be incorporated into all ongoing cohort studies related to diabetes risk. Studies in humans need to complement the elegant short-term laboratory-based human studies of simulated short sleep and shift work etc. with studies in subjects in the general population with these disorders. It is conceivable that chronic adaptations occur, and if so, the mechanisms by which they occur needs to be identified and understood. Particular areas of opportunity that are ready for translation are studies to address whether CPAP treatment of patients with pre-diabetes and obstructive sleep apnea (OSA) prevents or delays the onset of diabetes and whether temporal restricted feeding has the same impact on obesity rates in humans as it does in mice.

  16. Future projections of the Greenland ice sheet energy balance driving the surface melt

    Directory of Open Access Journals (Sweden)

    B. Franco

    2013-01-01

    Full Text Available In this study, simulations at 25 km resolution are performed over the Greenland ice sheet (GrIS throughout the 20th and 21st centuries, using the regional climate model MAR forced by four RCP scenarios from three CMIP5 global circulation models (GCMs, in order to investigate the projected changes of the surface energy balance (SEB components driving the surface melt. Analysis of 2000–2100 melt anomalies compared to melt results over 1980–1999 reveals an exponential relationship of the GrIS surface melt rate simulated by MAR to the near-surface air temperature (TAS anomalies, mainly due to the surface albedo positive feedback associated with the extension of bare ice areas in summer. On the GrIS margins, the future melt anomalies are preferentially driven by stronger sensible heat fluxes, induced by enhanced warm air advection over the ice sheet. Over the central dry snow zone, the surface albedo positive feedback induced by the increase in summer melt exceeds the negative feedback of heavier snowfall for TAS anomalies higher than 4 °C. In addition to the incoming longwave flux increase associated with the atmosphere warming, GCM-forced MAR simulations project an increase of the cloud cover decreasing the ratio of the incoming shortwave versus longwave radiation and dampening the albedo feedback. However, it should be noted that this trend in the cloud cover is contrary to that simulated by ERA-Interim–forced MAR for recent climate conditions, where the observed melt increase since the 1990s seems mainly to be a consequence of more anticyclonic atmospheric conditions. Finally, no significant change is projected in the length of the melt season, which highlights the importance of solar radiation absorbed by the ice sheet surface in the melt SEB.

  17. Two source energy balance model to calculate E, T, and ET: Comparison of Priestly-Taylor and Penman-Monteith formulations and two time scaling methods

    Science.gov (United States)

    The two source energy balance (TSEB) model calculates the energy balance of the soil–canopy–atmosphere continuum, where turbulent fluxes are based on the Priestley–Taylor equation. The TSEB was revised recently using the Penman–Monteith equation to replace the Priestley–Taylor formulation, thus bett...

  18. Benefit of regional energy balancing service on wind integration in the western interconnection of the United States

    Energy Technology Data Exchange (ETDEWEB)

    Milligan, Michael; Kirby, Brendan; King, Jack [National Renewable Energy Laboratory, Golden, CO (United States); Beuning, Stephen [Xcel Energy Inc., Minneapolis, MN (United States)

    2010-07-01

    Interest in various wide-area balancing schemes to help integrate wind have generated significant interest. As we have shown in past work, large balancing areas not only help with wind integration, but can also increase the efficiency of operations in systems without wind. Recent work on the Western Wind and Solar Integration Study (WWSIS) has found that combining balancing over the WestConnect footprint will increase the efficiency of commitment and dispatch at wind penetrations ranging from 10-30% of annual electricity demand, and will be essential for high penetrations and small balancing areas. In addition the northwest Wind Integration Action Plan recommended balancing area cooperation as a method to help integrate the large potential wind development. In this paper we investigate the potential impact of a proposed Energy Imbalance Service on the ability of the non-market portions of Western Electricity Coordinating Councils (WECC) United States footprint to integrate wind energy. We will utilize data adapted from the WWSIS for the Western Interconnection. The analysis uses time-synchronized wind and load data to evaluate the potential for ramp requirement reduction that could be achieved with combined operation. Chronological analysis and ramp duration analysis quantify the benefit in terms of not only the ramp sizes, but the frequency of the potentially avoided ramps that must be managed by the non-wind generation fleet. Multiple approaches that can be used to achieve these benefits are also suggested in the paper. We also suggest other approaches that can help achieve much of the benefit of full consolidation without requiring the physical consolidation of balancing areas. (orig.)

  19. Provisional energy balance of France for 2002; Bilan energetique provisoire de la France pour 2002

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    A provisional energy accounting in France for 2002 is presented. Statistical data and diagrams are provided to detail and discuss the economical and energy context, the primary energy consumption, the national production and the energy dependence, the primary energy consumption for each energy source, the sectorial analysis of the energy consumption and the carbon dioxide emissions. (A.L.B.)

  20. Actual Evapotranspiration in the Al-Khazir Gomal Basin (Northern Iraq Using the Surface Energy Balance Algorithm for Land (SEBAL and Water Balance

    Directory of Open Access Journals (Sweden)

    Hussein Jassas

    2015-04-01

    Full Text Available Increasing dependence on groundwater requires a detailed determination of the different outputs and inputs of a basin for better water management. Determination of spatial and temporal actual evapotranspiration (ETa, in this regard, is of vital importance as there is significant water loss from drainage basins. This research paper uses the Surface Energy Balance Algorithm for Land (SEBAL, as well as the water balance, to estimate the spatial and temporal ETa in the Al-Khazir Gomal Basin, Northern Iraq. To compensate for the shortage in rainfall, and to irrigate summer crops, farmers in this basin have been depending, to a large extent, on groundwater extracted from the underlying unconfined aquifer, which is considered the major source for both domestic and agricultural uses in this basin. Rainfed farming of wheat and barley is one of the most important activities in the basin in the winter season, while in the summer season, agricultural activity is limited to small rice fields and narrow strips of vegetable cultivation along the Al-Khazir River. The Landsat Thematic Mapper images (TM5 acquired on 21 November 2006, 9 March 2007, 5 May 2007, 21 July 2007, and 23 September 2007 were used, along with a digital elevation model (DEM and ground-based meteorological data, measured within the area of interest. Estimation of seasonal ETa from periods between satellite overpasses was computed using the evaporative fraction (Ʌ. The water balance approach was utilized, using meteorological data and river hydrograph analysis, to estimate the ETa as the only missing input in the predefined water balance equation. The results of the two applied methods were comparable. SEBAL results were compared with the land use land cover (LULC map. The river showed the highest ETa, as evaporation from the free-water surface. Rice fields, irrigated in the summer season, have a high ETa in the images, as these fields are immersed in water during June, July and August