VO2 thermochromic smart window for energy savings and generation
Zhou, Jiadong; Gao, Yanfeng; Zhang, Zongtao; Luo, Hongjie; Cao, Chuanxiang; Chen, Zhang; Dai, Lei; Liu, Xinling
2013-01-01
The ability to achieve energy saving in architectures and optimal solar energy utilisation affects the sustainable development of the human race. Traditional smart windows and solar cells cannot be combined into one device for energy saving and electricity generation. A VO2 film can respond to the environmental temperature to intelligently regulate infrared transmittance while maintaining visible transparency, and can be applied as a thermochromic smart window. Herein, we report for the first time a novel VO2-based smart window that partially utilises light scattering to solar cells around the glass panel for electricity generation. This smart window combines energy-saving and generation in one device, and offers potential to intelligently regulate and utilise solar radiation in an efficient manner. PMID:24157625
VO₂ thermochromic smart window for energy savings and generation.
Zhou, Jiadong; Gao, Yanfeng; Zhang, Zongtao; Luo, Hongjie; Cao, Chuanxiang; Chen, Zhang; Dai, Lei; Liu, Xinling
2013-10-24
The ability to achieve energy saving in architectures and optimal solar energy utilisation affects the sustainable development of the human race. Traditional smart windows and solar cells cannot be combined into one device for energy saving and electricity generation. A VO2 film can respond to the environmental temperature to intelligently regulate infrared transmittance while maintaining visible transparency, and can be applied as a thermochromic smart window. Herein, we report for the first time a novel VO2-based smart window that partially utilises light scattering to solar cells around the glass panel for electricity generation. This smart window combines energy-saving and generation in one device, and offers potential to intelligently regulate and utilise solar radiation in an efficient manner.
NASA Astrophysics Data System (ADS)
Krawczyk, Piotr
2013-12-01
Controlling low-temperature drying facilities which utilise nonprepared air is quite difficult, due to very large variability of ventilation air parameters - both in daily and seasonal cycles. The paper defines the concept of cumulative drying potential of ventilation air and presents experimental evidence that there is a relation between this parameter and condition of the dried matter (sewage sludge). Knowledge on current dry mass content in the dried matter (sewage sludge) provides new possibilities for controlling such systems. Experimental data analysed in the paper was collected in early 2012 during operation of a test solar drying facility in a sewage treatment plant in Błonie near Warsaw, Poland.
Solar flare induced cosmic noise absorption
NASA Astrophysics Data System (ADS)
Ogunmodimu, Olugbenga; Honary, Farideh; Rogers, Neil; Falayi, E. O.; Bolaji, O. S.
2018-06-01
Solar flare events are a major observing emphasis for space weather because they affect the ionosphere and can eject high-energy particles that can adversely affect Earth's technologies. In this study we model 38.2 MHz cosmic noise absorption (CNA) by utilising measurements from the Imaging Riometer for Ionospheric Studies (IRIS) at Kilpisjärvi, Finland obtained during solar cycle 23 (1996-2009). We utilised X-ray archive for the same period from the Geostationary Operational Environmental Satellite (GOES) to study solar flare induced cosmic noise absorption. We identified the threshold of flare (M4 class) that could bear significant influence on CNA. Through epoch analysis, we show the magnitude of absorption that each class of flare could produce. Using the parameters of flare and absorption we present a model that could provide the basis for nowcast of CNA induced by M and X-class solar flares.
Utilising shade to optimize UV exposure for vitamin D
NASA Astrophysics Data System (ADS)
Turnbull, D. J.; Parisi, A. V.
2008-01-01
Numerous studies have stated that humans need to utilise full sun radiation, at certain times of the day, to assist the body in synthesising the required levels of vitamin D3. The time needed to be spent in the full sun depends on a number of factors, for example, age, skin type, latitude, solar zenith angle. Current Australian guidelines suggest exposure to approximately 1/6 to 1/3 of a minimum erythemal dose (MED), depending on age, would be appropriate to provide adequate vitamin D3 levels. The aim of the study was to determine the exposure times to diffuse solar UV to receive exposures of 1/6 and 1/3 MED for a changing solar zenith angle in order to assess the possible role that diffuse UV (scattered radiation) may play in vitamin D3 effective UV exposures (UVD3). Diffuse and global erythemal UV measurements were conducted at five minute intervals over a twelve month period for a solar zenith angle range of 4° to 80° at a latitude of 27.6° S. For diffuse UV exposures of 1/6 and 1/3 MED, solar zenith angles smaller than 60° and 50° respectively can be utilised for exposure times of less than 10 min. Spectral measurements showed that, for a solar zenith angle of 40°, the UVA (315-400 nm) in the diffuse component of the solar UV is reduced by approximately 62% compared to the UVA in the global UV, whereas UVD3 wavelengths are only reduced by approximately 43%. At certain latitudes, diffuse UV under shade may play an important role in providing the human body with adequate levels of UVD3 (290-330 nm) radiation without experiencing the high levels of damaging UVA observed in full sun.
Utilising shade to optimize UV exposure for vitamin D
NASA Astrophysics Data System (ADS)
Turnbull, D. J.; Parisi, A. V.
2008-06-01
Numerous studies have stated that humans need to utilise full sun radiation, at certain times of the day, to assist the body in synthesising the required levels of vitamin D3. The time needed to be spent in the full sun depends on a number of factors, for example, age, skin type, latitude, solar zenith angle. Current Australian guidelines suggest exposure to approximately 1/6 to 1/3 of a minimum erythemal dose (MED), depending on age, would be appropriate to provide adequate vitamin D3 levels. The aim of the study was to determine the exposure times to diffuse solar UV to receive exposures of 1/6 and 1/3 MED for a changing solar zenith angle in order to assess the possible role that diffuse UV (scattered radiation) may play in vitamin D3 effective UV exposures (UVD3). Diffuse and global erythemal UV measurements were conducted at five minute intervals over a twelve month period for a solar zenith angle range of 4° to 80° at a latitude of 27.6° S. For a diffuse UV exposure of 1/3 MED, solar zenith angles smaller than approximately 50° can be utilised for exposure times of less than 10 min. Spectral measurements showed that, for a solar zenith angle of 40°, the UVA (315-400 nm) in the diffuse component of the solar UV is reduced by approximately 62% compared to the UVA in the global UV, whereas UVD3 wavelengths are only reduced by approximately 43%. At certain latitudes, diffuse UV under shade may play an important role in providing the human body with adequate levels of UVD3 (290-315 nm) radiation without experiencing the high levels of UVA observed in full sun.
Solar system for exploitation of the whole collected energy
NASA Astrophysics Data System (ADS)
Ciamberlini, C.; Francini, F.; Longobardi, G.; Piattelli, M.; Sansoni, P.
2003-09-01
An innovative architecture for the exploitation of the whole collected solar energy is described. A sun pointing optical concentrator focuses the received energy, containing the part of the required solar spectrum, in a low loss optical fibre transmission line. The optical panel is small in size and able to follow the sun in order to collect the maximum of its energy. The support is flat, 5 mm thick and includes four optical concentrators. The efficiency of the optical system depends on the optical configuration and on the material utilised for the optical components. Single commercial connector to the fixed fibres connects the fibre optics' four free ends. The energy is therefore properly transported to any user's end with an easy installation. The system was experimented for lightening, during the day, dissipated in a dark load in order to produce heat in some equipment and for photovoltaic applications. The total efficiency of the system was between 68% and 72%. Once the solar energy reaches the end of the transmission line, it can be addressed to the required utilisation by means of an optical switch, which redirects the sunlight towards the desired applicator. This procedure allows utilising the 100% of the sun-collected energy. Since the size of the panel was small, it can be placed, on the roof, on the garden, on the window-sill, on the field and on all sides exposed to sunlight.
Harwell, J R; Baikie, T K; Baikie, I D; Payne, J L; Ni, C; Irvine, J T S; Turnbull, G A; Samuel, I D W
2016-07-20
The field of organo-lead halide perovskite solar cells has been rapidly growing since their discovery in 2009. State of the art devices are now achieving efficiencies comparable to much older technologies like silicon, while utilising simple manufacturing processes and starting materials. A key parameter to consider when optimising solar cell devices or when designing new materials is the position and effects of the energy levels in the materials. We present here a comprehensive study of the energy levels present in a common structure of perovskite solar cell using an advanced macroscopic Kelvin probe and UV air photoemission setup. By constructing a detailed map of the energy levels in the system we are able to predict the importance of each layer to the open circuit voltage of the solar cell, which we then back up through measurements of the surface photovoltage of the cell under white illumination. Our results demonstrate the effectiveness of air photoemission and Kelvin probe contact potential difference measurements as a method of identifying the factors contributing to the open circuit voltage in a solar cell, as well as being an excellent way of probing the physics of new materials.
ERIC Educational Resources Information Center
Downs, Nathan; Larsen, Kim; Parisi, Alfio; Schouten, Peter; Brennan, Chris
2012-01-01
A practical exercise for developing a simple cost-effective solar ultraviolet radiation dosimeter is presented for use by middle school science students. Specifically, this exercise investigates a series of experiments utilising the historical blue print reaction, combining ammonium iron citrate and potassium hexacyanoferrate to develop an…
NASA Astrophysics Data System (ADS)
Chakravarty, S. C.; Nagaraja, Kamsali; Jakowski, N.
2017-03-01
The annual variations of ionospheric Total Electron Content (TEC), F-region peak ionisation (NmF2) and the ionospheric slab thickness (τ) over the Indian region during the low solar activity period of May 2007-April 2008 have been studied. For this purpose the ground based TEC data obtained from GAGAN measurements and the space based data from GPS radio occultation technique using CHAMP have been utilised. The results of these independent measurements are combined to derive additional parameters such as the equivalent slab thickness of the total and the bottom-side ionospheric regions (τT and τB). The one year hourly average values of all these parameters over the ionospheric anomaly latitude region (10-26°N) are presented here along with the statistical error estimates. It is expected that these results are potentially suited to be used as base level values during geomagnetically quiet and undisturbed solar conditions.
Solar sail science mission applications and advancement
NASA Astrophysics Data System (ADS)
Macdonald, Malcolm; McInnes, Colin
2011-12-01
Solar sailing has long been envisaged as an enabling or disruptive technology. The promise of open-ended missions allows consideration of radically new trajectories and the delivery of spacecraft to previously unreachable or unsustainable observation outposts. A mission catalogue is presented of an extensive range of potential solar sail applications, allowing identification of the key features of missions which are enabled, or significantly enhance, through solar sail propulsion. Through these considerations a solar sail application-pull technology development roadmap is established, using each mission as a technology stepping-stone to the next. Having identified and developed a solar sail application-pull technology development roadmap, this is incorporated into a new vision for solar sailing. The development of new technologies, especially for space applications, is high-risk. The advancement difficulty of low technology readiness level research is typically underestimated due to a lack of recognition of the advancement degree of difficulty scale. Recognising the currently low technology readiness level of traditional solar sailing concepts, along with their high advancement degree of difficulty and a lack of near-term applications a new vision for solar sailing is presented which increases the technology readiness level and reduces the advancement degree of difficulty of solar sailing. Just as the basic principles of solar sailing are not new, they have also been long proven and utilised in spacecraft as a low-risk, high-return limited-capability propulsion system. It is therefore proposed that this significant heritage be used to enable rapid, near-term solar sail future advancement through coupling currently mature solar sail, and other, technologies with current solar sail technology developments. As such the near-term technology readiness level of traditional solar sailing is increased, while simultaneously reducing the advancement degree of difficulty along the solar sail application-pull technology development roadmap.
Three-Axis Attitude Control of Solar Sails Utilising Reflectivity Control Devices
NASA Astrophysics Data System (ADS)
Theodorou, Theodoros
Solar sails are spacecraft that utilise the Solar Radiation Pressure, the force generated by impinging photons, to propel themselves. Conventional actuators are not suitable for controlling the attitude of solar sails therefore specific attitude control methods have been devised to tackle this. One of these methods is to change the centre of pressure with respect to the center of mass thus creating a torque. Reflectivity Control Devices (RCDs) have been proposed and successfully used to change the centre of pressure. Current methods that utilise RCDs have control authority over two axis only with no ability to control the torque about the normal of the sail surface. This thesis extends the state of the art and demonstrates 3-axis control by generating arbitrary torque vectors within a convex polyhedron. Two different RCD materials are considered, transmission and diffusion technologies both compatible with the proposed concept. A number of metrics have been developed which facilitate the comparison of different sail configurations. One of these metics is the sun map which is a graphic representation of the sun angles for which control authority is maintained. An iterative design process is presented which makes use of the metrics developed and aids in the design of a sail which meets the mission requirements and constraints. Moreover, the effects of different parameters on the performance of the proposed control concept are discussed. For example it is shown that by alternating the angle between the edge and middle RCDs the control authority increases. The concept's scalability has been investigated and a hybrid control scheme has been devised which makes use of both RCDs and reaction wheels. The RCDs are complemented by the reaction wheels to achieve higher slew rates while in turn the RCDs desaturate the reaction wheels. Finally, a number of simulations are conducted to verify the validity of the proposed concept.
Quantum Dot Sensitized Solar Cells Based on TiO2/AgInS2
NASA Astrophysics Data System (ADS)
Pawar, Sachin A.; Jeong, Jae Pil; Patil, Dipali S.; More, Vivek M.; Lee, Rochelle S.; Shin, Jae Cheol; Choi, Won Jun
2018-05-01
Quantum dot heterojunctions with type-II band alignment can efficiently separate photogenerated electron-hole pairs and, hence, are useful for solar cell studies. In this study, a quantum dot sensitized solar cell (QDSSC) made of TiO2/AgInS2 is achieved to boost the photoconversion efficiency for the TiO2-based system by varying the AgInS2 layer's thickness. The TiO2 nanorods array film is prepared by using a simple hydrothermal technique. The formation of a AgInS2 QD-sensitized TiO2-nanorod photoelectrode is carried out by successive ionic layer adsorption and reaction (SILAR) technique. The effect of the QD layer on the performance of the solar cell is studied by varying the SILAR cycles of the QD coating. The synthesized electrode materials are characterized by using X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, high resolution transmission electron microscopy and solar cell performances. The results indicate that the nanocrystals have effectively covered the outer surfaces of the TiO2 nanorods. The interfacial structure of quantum dots (QDs)/TiO2 is also investigated, and the growth interface is verified. A careful comparison between TiO2/AgInS2 sensitized cells reveals that the trasfer of electrons and hole proceeds efficiently, the recombination is suppressed for the optimum thickness of the QD layer and light from the entire visible spectrum is utilised. Under AM 1.5G illumination, a high photocurrent of 1.36 mAcm-2 with an improved power conversion efficiency of 0.48% is obtained. The solar cell properties of our photoanodes suggest that the TiO2 nanorod array films co-sensitized by AgInS2 nanoclusters have potential applications in solar cells.
Performance analysis of a solar still coupled with evacuated heat pipes
NASA Astrophysics Data System (ADS)
Pramod, B. V. N.; Prudhvi Raj, J.; Krishnan, S. S. Hari; Kotebavi, Vinod
2018-02-01
In developing countries the need for better quality drinking water is increasing steadily. We can overcome this need by using solar energy for desalination purpose. This process includes fabrication and analysis of a pyramid type solar still coupled with evacuated heat pipes. This experiment using evacuated heat pipes are carried in mainly three modes namely 1) Still alone 2) Using heat pipe with evacuated tubes 3)Using evacuated heat pipe. For this work single basin pyramid type solar still with 1m2 basin area is fabricated. Black stones and Black paint are utilised in solar still to increase evaporation rate of water in basin. The heat pipe’s evaporator section is placed inside evacuated tube and the heat pipe’s condenser section is connected directly to the pyramid type solar still’s lower portion. The output of distillate water from still with evacuated heat pipe is found to be 40% more than the still using only evacuated tubes.
A numerical model for thermal energy storage systems utilising encapsulated phase change materials
NASA Astrophysics Data System (ADS)
Jacob, Rhys; Saman, Wasim; Bruno, Frank
2016-05-01
In an effort to reduce the cost of thermal energy storage for concentrated solar power plants, a thermocline storage concept was investigated. Two systems were investigated being a sensible-only and an encapsulated phase change system. Both systems have the potential to reduce the storage tank volume and/or reduce the cost of the filler material, thereby reducing the cost of the system when compared to current two-tank molten salt systems. The objective of the current paper is to create a numerical model capable of designing and simulating the aforementioned thermocline storage concepts in the open source programming language known as Python. The results of the current study are compared to previous numerical results and are found to be in good agreement.
Dye-sensitized photocatalyst for effective water splitting catalyst
NASA Astrophysics Data System (ADS)
Watanabe, Motonori
2017-12-01
Renewable hydrogen production is a sustainable method for the development of next-generation energy technologies. Utilising solar energy and photocatalysts to split water is an ideal method to produce hydrogen. In this review, the fundamental principles and recent progress of hydrogen production by artificial photosynthesis are reviewed, focusing on hydrogen production from photocatalytic water splitting using organic-inorganic composite-based photocatalysts.
Optimal trajectories for solar bow shock mission
NASA Astrophysics Data System (ADS)
Pizzurro, S.; Circi, C.
2012-11-01
This paper deals a Solar Bow Shock mission, a phenomenon of interaction between the solar wind and the interstellar medium, due to the relative motion of our star with respect to the enormous interstellar matter cloud that contains it. This phenomenon occurs at boundary of the solar system (200 AU), and it is preferable a mission in situ that could examine in detail what actually happens on-the-spot, to understand its effect on the planets of the solar system. Voyager 1 & 2 reached the area where the phenomenon takes place after 30 years. The target is to arrive there optimizing both the transfer time, and the propellant mass consumption. Therefore, the trajectory will be optimized using different propulsion systems and appropriate flyby sequences.. The approach techniques that will be used foresee executions of impulsive or ballistic gravity assists with the utilisation of high thrust engine only, or low thrust engine only, or both engines in two different phases of the mission. By comparing all the solutions obtained imposing different initial conditions the optimal trajectory to arrive at Solar Bow Shock is presented.
Mass fractionation processes of transition metal isotopes
NASA Astrophysics Data System (ADS)
Zhu, X. K.; Guo, Y.; Williams, R. J. P.; O'Nions, R. K.; Matthews, A.; Belshaw, N. S.; Canters, G. W.; de Waal, E. C.; Weser, U.; Burgess, B. K.; Salvato, B.
2002-06-01
Recent advances in mass spectrometry make it possible to utilise isotope variations of transition metals to address some important issues in solar system and biological sciences. Realisation of the potential offered by these new isotope systems however requires an adequate understanding of the factors controlling their isotope fractionation. Here we show the results of a broadly based study on copper and iron isotope fractionation during various inorganic and biological processes. These results demonstrate that: (1) naturally occurring inorganic processes can fractionate Fe isotope to a detectable level even at temperature ˜1000°C, which challenges the previous view that Fe isotope variations in natural system are unique biosignatures; (2) multiple-step equilibrium processes at low temperatures may cause large mass fractionation of transition metal isotopes even when the fractionation per single step is small; (3) oxidation-reduction is an importation controlling factor of isotope fractionation of transition metal elements with multiple valences, which opens a wide range of applications of these new isotope systems, ranging from metal-silicate fractionation in the solar system to uptake pathways of these elements in biological systems; (4) organisms incorporate lighter isotopes of transition metals preferentially, and transition metal isotope fractionation occurs stepwise along their pathways within biological systems during their uptake.
Solar cells based on electrodeposited thin films of ZnS, CdS, CdSSe and CdTe
NASA Astrophysics Data System (ADS)
Weerasinghe, Ajith R.
The motivations of this research were to produce increased efficiency and low-cost solar cells. The production efficiency of Si solar cells has almost reached their theoretical limit, and reducing the manufacturing cost of Si solar cells is difficult to achieve due to the high-energy usage in material purifying and processing stages. Due to the low usage of materials and input energy, thin film solar cells have the potential to reduce the costs. CdS/CdTe thin film solar cells are already the cheapest on $/W basis. The cost of CdTe solar cells can be further reduced if all the semiconducting layers are fabricated using the electrodeposition (ED) method. ED method is scalable, low in the usage of energy and raw materials. These benefits lead to the cost effective production of semiconductors. The conventional method of fabricating CdS layers produces Cd containing waste solutions routinely, which adds to the cost of solar cells.ZnS, CdS and CdS(i-X)Sex buffer and window layers and CdTe absorber layers have been successfully electrodeposited and explored under this research investigation. These layers were fully characterised using complementary techniques to evaluate the material properties. Photoelectrochemical (PEC) studies, optical absorption, X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, atomic force microscopy (AFM) and Raman spectroscopy were utilised to evaluate the material properties of these solid thin film layers. ZnS and CdS thin film layers were electrodeposited from Na-free chemical precursors to avoid the group I element (Na) to reduce deterioration of CdTe devices. Deposition parameters such as, growth substrates, temperature, pH, growth cathodic voltage, stirring rate, time and chemical concentrations were identified to fabricate the above semiconductors. To further optimise these layers, a heat treatment process specific to the material was developed. In addition, the deposition parameters of CdTe layers were further optimised. This research programme has demonstrated that electrodeposited ZnS, CdS and CdTe thin film layers have material characteristics comparable with those of the materials reported in the literature and can be used in thin film solar cell devices. Furthermore, the electrolytes were used for up to two years, reducing the wastage even further, in comparison to other fabrication methods, such as chemical bath deposition. Several large-area semiconducting layers were successfully fabricated to test the scalability of the method. Nano-rods perpendicular to the glass/FTO surface with gaps among grains in CdS layers were observed. In order to reduce the possible pinholes due the gaps, a deposition of a semiconducting layer to cover completely the substrate was investigated. CdS(i-X)Sex layers were investigated to produce a layer-by-layer deposition of the material. However it was observed the surface morphology of CdS(j.X)Sex is a function of the growth parameters which produced nano-wires, nano-tubes and nano-sheets. This is the first recording of this effect for a low temperature deposition method, minimising the cost of producing this highly photosensitive material for use in various nano technology applications.The basic structure experimented was glass/conducting-glass/buffer layer/window material/absorber material/metal. By utilising all the semiconducting layers developed, several solar cell device structures were designed, fabricated and tested. This included a novel all-electrodeposited multi-layer graded bandgap device, to enhance the absorption of solar photons. The device efficiencies varied from batch to batch, and efficiencies in the range (3-7)% were observed. The variations in chemical concentrations, surface states and the presence of pin-hole defects in CdS were the main reasons for the range of efficiencies obtained. In the future work section, ways to avoid these variations and to increase efficiencies are identified and presented.
Building a Laboratory-Scale Biogas Plant and Verifying its Functionality
NASA Astrophysics Data System (ADS)
Boleman, Tomáš; Fiala, Jozef; Blinová, Lenka; Gerulová, Kristína
2011-01-01
The paper deals with the process of building a laboratory-scale biogas plant and verifying its functionality. The laboratory-scale prototype was constructed in the Department of Safety and Environmental Engineering at the Faculty of Materials Science and Technology in Trnava, of the Slovak University of Technology. The Department has already built a solar laboratory to promote and utilise solar energy, and designed SETUR hydro engine. The laboratory is the next step in the Department's activities in the field of renewable energy sources and biomass. The Department is also involved in the European Union project, where the goal is to upgrade all existed renewable energy sources used in the Department.
Performance analysis of phase-change material storage unit for both heating and cooling of buildings
NASA Astrophysics Data System (ADS)
Waqas, Adeel; Ali, Majid; Ud Din, Zia
2017-04-01
Utilisation of solar energy and the night ambient (cool) temperatures are the passive ways of heating and cooling of buildings. Intermittent and time-dependent nature of these sources makes thermal energy storage vital for efficient and continuous operation of these heating and cooling techniques. Latent heat thermal energy storage by phase-change materials (PCMs) is preferred over other storage techniques due to its high-energy storage density and isothermal storage process. The current study was aimed to evaluate the performance of the air-based PCM storage unit utilising solar energy and cool ambient night temperatures for comfort heating and cooling of a building in dry-cold and dry-hot climates. The performance of the studied PCM storage unit was maximised when the melting point of the PCM was ∼29°C in summer and 21°C during winter season. The appropriate melting point was ∼27.5°C for all-the-year-round performance. At lower melting points than 27.5°C, declination in the cooling capacity of the storage unit was more profound as compared to the improvement in the heating capacity. Also, it was concluded that the melting point of the PCM that provided maximum cooling during summer season could be used for winter heating also but not vice versa.
Ha, Ninh Thi; Harris, Mark; Preen, David; Robinson, Suzanne; Moorin, Rachael
2018-04-01
We aimed to characterise use of general practitioners (GP) simultaneously across multiple attributes in people with diabetes and examine its impact on diabetes related potentially preventable hospitalisations (PPHs). Five-years of panel data from 40,625 adults with diabetes were sourced from Western Australian administrative health records. Cluster analysis (CA) was used to group individuals with similar patterns of GP utilisation characterised by frequency and recency of services. The relationship between GP utilisation cluster and the risk of PPHs was examined using multivariable random-effects negative binomial regression. CA categorised GP utilisation into three clusters: moderate; high and very high usage, having distinct patient characteristics. After adjusting for potential confounders, the rate of PPHs was significantly lower across all GP usage clusters compared with those with no GP usage; IRR = 0.67 (95%CI: 0.62-0.71) among the moderate, IRR = 0.70 (95%CI 0.66-0.73) high and IRR = 0.76 (95%CI 0.72-0.80) very high GP usage clusters. Combination of temporal factors with measures of frequency of use of GP services revealed patterns of primary health care utilisation associated with different underlying patient characteristics. Incorporation of multiple attributes, that go beyond frequency-based approaches may better characterise the complex relationship between use of GP services and diabetes-related hospitalisation. Copyright © 2018 Elsevier B.V. All rights reserved.
Efficient conversion of solar energy to biomass and electricity
2014-01-01
The Earth receives around 1000 W.m−2 of power from the Sun and only a fraction of this light energy is able to be converted to biomass (chemical energy) via the process of photosynthesis. Out of all photosynthetic organisms, microalgae, due to their fast growth rates and their ability to grow on non-arable land using saline water, have been identified as potential source of raw material for chemical energy production. Electrical energy can also be produced from this same solar resource via the use of photovoltaic modules. In this work we propose a novel method of combining both of these energy production processes to make full utilisation of the solar spectrum and increase the productivity of light-limited microalgae systems. These two methods of energy production would appear to compete for use of the same energy resource (sunlight) to produce either chemical or electrical energy. However, some groups of microalgae (i.e. Chlorophyta) only require the blue and red portions of the spectrum whereas photovoltaic devices can absorb strongly over the full range of visible light. This suggests that a combination of the two energy production systems would allow for a full utilization of the solar spectrum allowing both the production of chemical and electrical energy from the one facility making efficient use of available land and solar energy. In this work we propose to introduce a filter above the algae culture to modify the spectrum of light received by the algae and redirect parts of the spectrum to generate electricity. The electrical energy generated by this approach can then be directed to running ancillary systems or producing extra illumination for the growth of microalgae. We have modelled an approach whereby the productivity of light-limited microalgae systems can be improved by at least 4% through using an LED array to increase the total amount of illumination on the microalgae culture. PMID:24976951
Efficient conversion of solar energy to biomass and electricity.
Parlevliet, David; Moheimani, Navid Reza
2014-01-01
The Earth receives around 1000 W.m(-2) of power from the Sun and only a fraction of this light energy is able to be converted to biomass (chemical energy) via the process of photosynthesis. Out of all photosynthetic organisms, microalgae, due to their fast growth rates and their ability to grow on non-arable land using saline water, have been identified as potential source of raw material for chemical energy production. Electrical energy can also be produced from this same solar resource via the use of photovoltaic modules. In this work we propose a novel method of combining both of these energy production processes to make full utilisation of the solar spectrum and increase the productivity of light-limited microalgae systems. These two methods of energy production would appear to compete for use of the same energy resource (sunlight) to produce either chemical or electrical energy. However, some groups of microalgae (i.e. Chlorophyta) only require the blue and red portions of the spectrum whereas photovoltaic devices can absorb strongly over the full range of visible light. This suggests that a combination of the two energy production systems would allow for a full utilization of the solar spectrum allowing both the production of chemical and electrical energy from the one facility making efficient use of available land and solar energy. In this work we propose to introduce a filter above the algae culture to modify the spectrum of light received by the algae and redirect parts of the spectrum to generate electricity. The electrical energy generated by this approach can then be directed to running ancillary systems or producing extra illumination for the growth of microalgae. We have modelled an approach whereby the productivity of light-limited microalgae systems can be improved by at least 4% through using an LED array to increase the total amount of illumination on the microalgae culture.
The utilisation of health research in policy-making: concepts, examples and methods of assessment
Hanney, Stephen R; Gonzalez-Block, Miguel A; Buxton, Martin J; Kogan, Maurice
2003-01-01
The importance of health research utilisation in policy-making, and of understanding the mechanisms involved, is increasingly recognised. Recent reports calling for more resources to improve health in developing countries, and global pressures for accountability, draw greater attention to research-informed policy-making. Key utilisation issues have been described for at least twenty years, but the growing focus on health research systems creates additional dimensions. The utilisation of health research in policy-making should contribute to policies that may eventually lead to desired outcomes, including health gains. In this article, exploration of these issues is combined with a review of various forms of policy-making. When this is linked to analysis of different types of health research, it assists in building a comprehensive account of the diverse meanings of research utilisation. Previous studies report methods and conceptual frameworks that have been applied, if with varying degrees of success, to record utilisation in policy-making. These studies reveal various examples of research impact within a general picture of underutilisation. Factors potentially enhancing utilisation can be identified by exploration of: priority setting; activities of the health research system at the interface between research and policy-making; and the role of the recipients, or 'receptors', of health research. An interfaces and receptors model provides a framework for analysis. Recommendations about possible methods for assessing health research utilisation follow identification of the purposes of such assessments. Our conclusion is that research utilisation can be better understood, and enhanced, by developing assessment methods informed by conceptual analysis and review of previous studies. PMID:12646071
Chung, Wing Sun Faith; Meijerink, Marjolein; Zeuner, Birgitte; Holck, Jesper; Louis, Petra; Meyer, Anne S; Wells, Jerry M; Flint, Harry J; Duncan, Sylvia H
2017-11-01
Dietary plant cell wall carbohydrates are important in modulating the composition and metabolism of the complex gut microbiota, which can impact on health. Pectin is a major component of plant cell walls. Based on studies in model systems and available bacterial isolates and genomes, the capacity to utilise pectins for growth is widespread among colonic Bacteroidetes but relatively uncommon among Firmicutes. One Firmicutes species promoted by pectin is Eubacterium eligens. Eubacterium eligens DSM3376 utilises apple pectin and encodes a broad repertoire of pectinolytic enzymes, including a highly abundant pectate lyase of around 200 kDa that is expressed constitutively. We confirmed that certain Faecalibacterium prausnitzii strains possess some ability to utilise apple pectin and report here that F. prausnitzii strains in common with E. eligens can utilise the galacturonide oligosaccharides DP4 and DP5 derived from sugar beet pectin. Faecalibacterium prausnitzii strains have been shown previously to exert anti-inflammatory effects on host cells, but we show here for the first time that E. eligens strongly promotes the production of the anti-inflammatory cytokine IL-10 in in vitro cell-based assays. These findings suggest the potential to explore further the prebiotic potential of pectin and its derivatives to re-balance the microbiota towards an anti-inflammatory profile. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Shilton, A N; Mara, D D; Craggs, R; Powell, N
2008-01-01
Waste stabilisation pond (WSP) technology offers some important advantages and interesting possibilities when viewed in the light of sustainable energy and carbon management. Pond systems stand out as having significant advantages due to simple construction; low (or zero) operating energy requirements; and the potential for bio-energy generation. Conventional WSP requires little or no electrical energy for aerobic treatment as a result of algal photosynthesis. Sunlight enables WSP to disinfect wastewaters very effectively without the need for any chemicals or electricity consumption and their associated CO(2) emissions. The energy and carbon emission savings gained over electromechanical treatment systems are immense. Furthermore, because algal photosynthesis consumes CO(2), WSP can be utilised as CO(2) scrubbers. The environmental and financial benefits of pond technology broaden further when considering the low-cost, energy production opportunities of anaerobic ponds and the potential of algae as a biofuel. As we assess future best practice in wastewater treatment technology, perhaps one of the greatest needs is an improved consideration of the carbon footprint and the implications of future increases in the cost of electricity and the value of biogas. (c) IWA Publishing 2008.
Parisi, A V; Downs, N; Turner, J; Amar, A
2016-09-01
A set of online activities for children and the community that are based on an integrated real-time solar UV and cloud measurement system are described. These activities use the functionality of the internet to provide an educative tool for school children and the public on the influence of cloud and the angle of the sun above the horizon on the global erythemal UV or sunburning UV, the diffuse erythemal UV, the global UVA (320-400nm) and the vitamin D effective UV. Additionally, the units of UV exposure and UV irradiance are investigated, along with the meaning and calculation of the UV index (UVI). This research will help ensure that children and the general public are better informed about sun safety by improving their personal understanding of the daily and the atmospheric factors that influence solar UV radiation and the solar UV exposures of the various wavebands in the natural environment. The activities may correct common misconceptions of children and the public about UV irradiances and exposure, utilising the widespread reach of the internet to increase the public's awareness of the factors influencing UV irradiances and exposures in order to provide clear information for minimizing UV exposure, while maintaining healthy, outdoor lifestyles. Copyright © 2016 Elsevier B.V. All rights reserved.
Protecting the Moon for research: ILEWG report
NASA Astrophysics Data System (ADS)
Foing, Bernard H.
We give a report on recommendations with emphasis on environment protection, and since last COSPAR from ILEWG International conferences Exploration and Utilisation of the Moon on held at Cape Canaveral in 2008 (ICEUM10), and in Beijing in May 2010 with IAF (GLUC -ICEUM11). We discuss the different rationale for Moon exploration, as debated at ILEWG. ILEWG Science task group has listed priorities for scientific investigations: clues on the formation and evolution of rocky planets, accretion and bombardment in the inner solar system, comparative planetology processes (tectonic, volcanic, impact cratering, volatile delivery), records astrobiology, survival of organics; past, present and future life; sciences from a biology lunar laboratory. We discuss how to preserve Moon research potential in these areas while operating with instruments, landers, rover during a cooperative robotic village, and during the transition form lunar human outpost to permanent sustainable human base. We discuss how Moon-Mars Exploration can inspire solutions to global Earth sustained development with the trade-off of In-Situ Utilisation of resources; Establishment of permanent robotic infrastructures, Environmental and planetary protection aspects and lessons for Mars; Life sciences laboratories, and support to human exploration. Co-authors: ILEWG Task Groups on Science, Technology and Human Lunar Bases ILEWG Reference documents: http://sci.esa.int/ilewg -10th ILEWG Conference on Exploration and Utilisation of the Moon, NASA Lunar Ex-ploration Analysis Group-PSace Resources Roundtable, Cape Canaveral October 2008, pro-gramme online at http://sci.esa.int/ilewg/ -9th ILEWG Conference on Exploration and Utilisation of the Moon, ICEUM9 Sorrento 2007, programme online at http://sci.esa.int/ilewg/ -8th ILEWG Conference on Exploration and Utilisation of the Moon, Beijing July 2006, programme online at http://sci.esa.int/ilewg/ -The Moon and Near Earth Objects (P. Ehrenfreund , B.H. Foing, A. Cellino Editors), Ad-vances in Space Research, Volume 37, Issue 1, pp 1-192, 2006 -7th ILEWG Conference on Exploration and Utilisation of the Moon, Toronto Sept 2005, Programme and Proceedings on line at www.ilewg.org, R. Richards et al Editors -6th ILEWG Conference on Exploration and Utilisation of the Moon, Udaipur Nov. 2004, Proceedings ( N. Bhandari Editor), Journal Earth System Science, India, 114, No6, Dec 2005, pp. 573-841 -5th ILEWG Conference on Exploration and Utilisation of the Moon, Hawaii Nov 2003, Pro-ceedings ILC2005/ICEUM5 (S.M. Durst et al Editors), Vol 108, 1-576 pp, Science and Tech-nology Series, American Astronautical Society, 2004 -'The next steps in exploring deep space -A cosmic study by the IAA', W. Huntress, D. Stetson, R. Farquhar, J. Zimmerman, B. Clark, W. O'Neil, R. Bourke and B. Foing, Acta Astronautica, Vol 58, Issues 6-7, March-April 2006, p302-377 -IAA/ESA workshop on "Next Steps in Exploring Deep Space", ESTEC 22-23 sept. 2003 (B.H. Foing W. Huntress, conveners) Lunar Exploration, Planetary and Space Science, Vol 50, issue 14-15, Dec 2002 (B.H. Foing al) -ESLAB36 symposium on "Earth-like Planets and Moons", 2002, ESA-SP514, pp. 1-356, (B.H.Foing B. Battrick, editors) -'Lunar Exploration 2000', (B.H. Foing, D. Heather, Editors), Adv. Space Research Vol 30, Nr 8, 2002 -'Earth-Moon Relationships', Proceedings of the Conference held in Padova, Italy at the Ac-cademia Galileiana di Scienze Lettere ed Arti, Nov. 2000, (C. Barbieri and F. Rampazzi, Editors), in Earth, Moon , Planets Vol. 85-86, Nos 1-3, pp 1-575, 2001 -4th International Conference on Exploration and Utilisation of the Moon, ESTEC, 2000, ESA SP-462 (B.H. Foing M. Perry, editors) -Investing in Space: The Challenge for Europe. Long-Term Space Policy Committee, Second Report, May 1999. ESA-SP-2000 -2nd International Lunar Workshop, held at Kyoto in October 1996, Proceedings, H. Mizutani, editor, Japan Space Forum Publisher, 1997 International Lunar Workshop, 1994 May 31-June 3, Beatenberg, Switzerland. Proceedings. Ed. Balsiger, H. et al. European Space Agency, 1994. ESA-SP-1170 -Astronomy and Space Science from the Moon', Proceedings of COSPAR/IAF session at World Congress, Washington, (B.H. Foing et al editors), Advances in Space Research, Volume 14, Issue 6, 1994 -Mission to the Moon, Europe's Priorities for Scientific Exploration and Utilisation of the Moon', R.M. Bonnet et al, European Space Agency, ESA SP-1150, June 1992
NASA Astrophysics Data System (ADS)
Staff, Richard; Hardiman, Mark; Bronk Ramsey, Christopher; Hare, Vincent; Koutsodendris, Andreas; Pross, Jörg
2017-04-01
Cosmogenic radionuclides, such as 10Be and 14C, share a common production signal, with their formation in the Earth's upper atmosphere modulated by changes to the geomagnetic field, as well as variations in the intensity of the solar wind. Here, we present 54 14C measurements from a terrestrial fen peat core extracted from the site of Tenaghi Philippon, NE Greece, contiguously spanning the time period between 48,000 and 39,000 cal. BP. Utilising the most pronounced cosmogenic production peak of the last 100,000 years - that associated with the Laschamp geomagnetic excursion circa 41,000 years ago - we exploit this common production signal, comparing Greenland 10Be with our Tenaghi Philippon 14C record, thereby providing a means to assess the concordance between the radiocarbon (IntCal) and Greenland ice-core (GICC05) timescales themselves for this, the oldest portion of the radiocarbon technique.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Talewar, R. A., E-mail: talewarrupesh@gmail.com; Joshi, C. P.; Moharil, S. V.
2016-05-23
The efficiency of CdTe/CdS solar cell can be significantly improved by using luminescent down-shifting material on their front surface. Taking this into account a red emitting phosphor K{sub 2}Si{sub 1-x}F{sub 6}:xMn{sup 4+} (x=10 to 25 mol %) has been synthesized through wet chemical method. The as-synthesized materials were characterized by powder x-ray diffraction (XRD) and photoluminescence (PL) techniques. The photoluminescence studies of K{sub 2}SiF{sub 6}:Mn{sup 4+} revealed enhancement in the emission intensity, when Mn{sup 4+} concentration was increased from 10 mol % to 25 mol %. This red emitting phosphor efficiently absorbs the photons typically in the region 300-500 nmmore » and re-emits in the region where the photovoltaic device exhibits significantly better response. The results show the possibility of enhancing the photovoltaic conversion efficiency of CdTe thin film solar cell by modifying the absorption spectra and utilising the energy in the UV-blue part of the solar spectrum.« less
The smartphone in the memory clinic: A study of patient and care partner's utilisation habits.
Benge, Jared F; Dinh, Kara L; Logue, Erin; Phenis, Richard; Dasse, Michelle N; Scullin, Michael K
2018-04-16
Smartphones have potential as cognitive aids for adults with cognitive impairments. However, little is known about how patients and their care partners utilise smartphones in their day-to-day lives. We collected self-reported smartphone utilisation data from patients referred for neuropsychological evaluations (N = 53), their care partners (N = 44), and an Amazon Mechanical Turk control sample (N = 204). Patient participants were less likely to own a smartphone than controls, with increasing age associated with less utilisation of smartphone features in all groups. Of the patients who owned smartphones, spontaneous use of cognitive aid features (e.g., reminders and calendars) occurred on only a monthly-to-weekly basis; by comparison, patients reported utilising social/general features (e.g., email and internet) on a weekly-to-daily basis. Individuals referred for geriatric cognitive disorder evaluations were less likely to own and use smartphones than individuals referred for other reasons. Care partners reported using their smartphones more frequently than control group adults, with 55% of care partners endorsing utilising their device in caring for the patient. Building upon existing smartphone use habits to increase the use of cognitive aid features may be a feasible intervention for some patients, and including care partners in such interventions is encouraged.
An environmental analysis of options for utilising wasted food and food residue.
Oldfield, Thomas L; White, Eoin; Holden, Nicholas M
2016-12-01
The potential environmental impact of wasted food minimisation versus its utilisation in a circular bioeconomy is investigated based on a case study of Ireland. The amount of wasted food and food residue (WFFR) produced in 2010 was used for business-as-usual, (a) and four management options were assessed, (b) minimisation, (c) composting, (d) anaerobic digestion and (e) incineration. The environmental impacts Global Warming Potential (GWP), Acidification Potential (AP) and Eutrophication Potential (EP) were considered. A carbon return on investment (CRoI) was calculated for the three processing technologies (c-e). The results showed that a minimisation strategy for wasted food would result in the greatest reduction of all three impacts, -4.5 Mt CO 2 -e (GWP), -11.4 kt PO 4 3 -e (EP) and -43.9 kt SO 2 -e (AP) compared to business as usual. For WFFR utilisation in the circular bioeconomy, anaerobic digestion resulted in the lowest environmental impact and best CRoI of -0.84 kg CO 2 -e per Euro. From an economic perspective, for minimisation to be beneficial, 0.15 kg of wasted food would need to be reduced per Euro spent. Copyright © 2016 Elsevier Ltd. All rights reserved.
Wallis, Corrin V; Lowden, Preena; Marshall-Jones, Zoe V; Hilton, Anthony C
2018-02-26
Salmonella enterica is a recognised cause of diarrhoea in dogs and humans, yet the potential for transfer of salmonellosis between dogs and their owners is unclear, with reported evidence both for and against Salmonella as a zoonotic pathogen. A collection of 174 S. enterica isolates from clinical infections in humans and dogs were analysed for serotype distribution, carbon source utilisation, chemical and antimicrobial sensitivity profiles. The aim of the study was to understand the degree of conservation in phenotypic characteristics of isolates across host species. Serovar distribution across human and canine isolates demonstrated nine serovars common to both host species, 24 serovars present in only the canine collection and 39 solely represented within the human collection. Significant differences in carbon source utilisation profiles and ampicillin, amoxicillin and chloramphenicol sensitivity profiles were detected in isolates of human and canine origin. Differences between the human and canine Salmonella collections were suggestive of evolutionary separation, with canine isolates better able to utilise several simple sugars than their human counterparts. Generally higher minimum inhibitory concentrations of three broad-spectrum antimicrobials, commonly used in veterinary medicine, were also observed in canine S. enterica isolates. Differential carbon source utilisation and antimicrobial sensitivity profiles in pathogenic Salmonella isolated from humans and dogs are suggestive of distinct reservoirs of infection for these hosts. Although these findings do not preclude zoonotic or anthroponotic potential in salmonellae, the separation of carbon utilisation and antibiotic profiles with isolate source is indicative that infectious isolates are not part of a common reservoir shared frequently between these host species.
The effect of amorphous TiO2 in P25 on dye-sensitized solar cell performance.
Al-Attafi, Kadhim; Nattestad, Andrew; Wu, Qijie; Ide, Yusuke; Yamauchi, Yusuke; Dou, Shi Xue; Kim, Jung Ho
2018-01-04
P25 is one of the most widely used forms of titanium(iv) oxide (TiO 2 ), routinely utilised in dye-sensitised solar cells (DSCs), where it is often employed as a control, in spite of its poorly defined nature and the typically low device efficiency (or possibly because of this). Work by Park in 2000 and later by Lin et al. suggests that the rutile component might not be to blame for this, as has often been claimed. Recently it has been observed that P25 has quite a sizable amorphous content. A method to selectively remove this non-crystalline material has been developed, allowing for scrutiny of the role this amorphous material plays. Here we compare hydrothermally treated P25 (H-P25) with the as-received material, realizing solar-to-electric conversion efficiencies of 5.3% and 3.2% respectively. More importantly, this reveals important information about the detrimental effect of amorphous TiO 2 on DSC performance, with broader implications, as most researchers do not actively examine their synthesized materials for the presence of an amorphous component.
Schaper, Louise K; Pervan, Graham P
2007-06-01
There is evidence to suggest that health professionals are reluctant to accept and utilise information and communication technologies (ICT) and concern is growing within health informatics research that this is contributing to the lag in adoption and utilisation of ICT across the health sector. Technology acceptance research within the field of information systems has been limited in its application to health and there is a concurrent need to develop and gain empirical support for models of technology acceptance within health and to examine acceptance and utilisation issues amongst health professionals to improve the success of information system implementation in this arena. This paper outlines a project that examines ICT acceptance and utilisation by Australian occupational therapists. It describes the theoretical basis behind the development of a research model and the methodology being employed to empirically validate the model using substantial quantitative, qualitative and longitudinal data. Preliminary results from Phase II of the study are presented. The theoretical significance of this work is that it uses a thoroughly constructed research model, with potentially the largest sample size ever tested, to extend technology acceptance research into the health sector.
Gove, Benedict; Williams, Leah J.; Beresford, Alison E.; Roddis, Philippa; Campbell, Colin; Teuten, Emma; Langston, Rowena H. W.; Bradbury, Richard B.
2016-01-01
Renewable energy will potentially make an important contribution towards the dual aims of meeting carbon emission reduction targets and future energy demand. However, some technologies have considerable potential to impact on the biodiversity of the environments in which they are placed. In this study, an assessment was undertaken of the realistic deployment potential of a range of renewable energy technologies in the UK, considering constraints imposed by biodiversity conservation priorities. We focused on those energy sources that have the potential to make important energy contributions but which might conflict with biodiversity conservation objectives. These included field-scale solar, bioenergy crops, wind energy (both onshore and offshore), wave and tidal stream energy. The spatially-explicit analysis considered the potential opportunity available for each technology, at various levels of ecological risk. The resultant maps highlight the energy resource available, physical and policy constraints to deployment, and ecological sensitivity (based on the distribution of protected areas and sensitive species). If the technologies are restricted to areas which currently appear not to have significant ecological constraints, the total potential energy output from these energy sources was estimated to be in the region of 5,547 TWh/yr. This would be sufficient to meet projected energy demand in the UK, and help to achieve carbon reduction targets. However, we highlight two important caveats. First, further ecological monitoring and surveillance is required to improve understanding of wildlife distributions and therefore potential impacts of utilising these energy sources. This is likely to reduce the total energy available, especially at sea. Second, some of the technologies under investigation are currently not deployed commercially. Consequently this potential energy will only be available if continued effort is put into developing these energy sources/technologies, to enable realisation of their full potential. PMID:27224050
Gove, Benedict; Williams, Leah J; Beresford, Alison E; Roddis, Philippa; Campbell, Colin; Teuten, Emma; Langston, Rowena H W; Bradbury, Richard B
2016-01-01
Renewable energy will potentially make an important contribution towards the dual aims of meeting carbon emission reduction targets and future energy demand. However, some technologies have considerable potential to impact on the biodiversity of the environments in which they are placed. In this study, an assessment was undertaken of the realistic deployment potential of a range of renewable energy technologies in the UK, considering constraints imposed by biodiversity conservation priorities. We focused on those energy sources that have the potential to make important energy contributions but which might conflict with biodiversity conservation objectives. These included field-scale solar, bioenergy crops, wind energy (both onshore and offshore), wave and tidal stream energy. The spatially-explicit analysis considered the potential opportunity available for each technology, at various levels of ecological risk. The resultant maps highlight the energy resource available, physical and policy constraints to deployment, and ecological sensitivity (based on the distribution of protected areas and sensitive species). If the technologies are restricted to areas which currently appear not to have significant ecological constraints, the total potential energy output from these energy sources was estimated to be in the region of 5,547 TWh/yr. This would be sufficient to meet projected energy demand in the UK, and help to achieve carbon reduction targets. However, we highlight two important caveats. First, further ecological monitoring and surveillance is required to improve understanding of wildlife distributions and therefore potential impacts of utilising these energy sources. This is likely to reduce the total energy available, especially at sea. Second, some of the technologies under investigation are currently not deployed commercially. Consequently this potential energy will only be available if continued effort is put into developing these energy sources/technologies, to enable realisation of their full potential.
Hu, Shaowen; Cucinotta, Francis A
2011-02-01
As significant ionising radiation exposure will occur during prolonged space travel in future, it is essential to understand their adverse effects on the radiosensitive organ systems that are important for immediate survival of humans, e.g. the haematopoietic system. In this paper, a biomathematical model of granulopoiesis is used to analyse the granulocyte changes seen in the blood of mammalians under acute and continuous radiation exposure. This is one of a set of haematopoietic models that have been successfully utilised to simulate and interpret the experimental data of acute and chronic radiation on rodents. Extension to canine and human systems indicates that the results of the model are consistent with the cumulative experimental and empirical data from various sources, implying the potential to integrate them into one united model system to monitor the haematopoietic response of various species under irradiation. The suppression of granulocytes' level of a space traveller under chronic stress of low-dose irradiation as well as the granulopoietic response when encountering a historically large solar particle event is also discussed.
Burr, David J; Martin, Andrew; Maas, Elizabeth W; Ryan, Ken G
2017-09-01
Proteorhodopsin (PR) is a wide-spread protein found in many marine prokaryotes. PR allows for the potential conversion of solar energy to ATP, possibly assisting in cellular growth and survival during periods of high environmental stress. PR utilises either blue or green light through a single amino acid substitution. We incubated the PR-bearing bacterium Psychroflexus torquis 50 cm deep within Antarctic sea ice for 13 days, exposing cultures to diurnal fluctuations in light and temperature. Enhanced growth occurred most prominently in cultures incubated under irradiance levels of ∼50 μmol photons m -2 s -1 , suggesting PR provides a strong selective advantage. In addition, cultures grown under blue light yielded over 5.5 times more live cells per photon compared to green-light incubations. Because P. torquis expresses an apparently 'green-shifted' PR gene variant, this finding infers that the spectral tuning of PR is more complex than previously thought. This study supports the theory that PR provides additional energy to bacteria under sub-optimal conditions, and raises several points of interest to be addressed by future research.
Utilisation of inorganic salts in fungal crop disease management in the U.K.
Deliopoulos, T; Kettlewell, P S; Hare, M C
2009-01-01
The overaLl aim of the study described in this communication was to utilise the findings of a global scientific and technical literature survey on the use of inorganic salts against crop fungal diseases in order to assess the potential of using these substances to reduce the reliance of UK growers on conventional fungicides. A summary of the main findings of the Literature survey is provided followed by information on the current commercial use of inorganic salt-based products in fungal disease management. Finally, the scope of potential use of inorganic salts on high disease risk crops in the UK is assessed and specific crop/pathogen combinations are prioritised for further research.
NASA Astrophysics Data System (ADS)
Bovill, E.; Scarratt, N.; Griffin, J.; Yi, H.; Iraqi, A.; Buckley, A. R.; Kingsley, J. W.; Lidzey, D. G.
2015-02-01
We have made a comparative study of the relative operational stability of bulk-heterojunction organic photovoltaic (OPV) devices utilising different hole transport layers (HTLs). OPV devices were fabricated based on a blend of the polymer PCDTBT with the fullerene PC70BM, and incorporated the different HTL materials PEDOT:PSS, MoOx and V2O5. Following 620 h of irradiation by light from a solar simulator, we find that devices using the PEDOT:PSS HTL retained the highest efficiency, having a projected T80 lifetime of 14 500 h.
Nanoscale Light Manipulation for Improved Organic Solar Cells
NASA Astrophysics Data System (ADS)
Fisher, Brett
Organic Solar Cells can be made to be flexible, semi-transparent, and low-cost making them ideal for novel energy harvesting applications such as in greenhouses. However, the main disadvantage of this technology is its low energy conversion efficiency (<15%); mostly due to high recombination rates, compared with other higher performing technologies, such as thinfilm GaAs (>30% Efficiency), and Si-based (>20% Efficiency), solar cells, where recombination within these technologies is much less than Organic Solar Cells. There are still many challenges to overcome to improve the efficiency of Organic Solar Cells. Some of these challenges include: Maximising the absorption of the solar spectrum; improving the charge dynamics; and increasing the lifetime of the devices. One method to address some of these challenges is to include plasmonic nanoparticles into the devices, which has been shown to increase the absorption through scattering, and improve the charge dynamic through localised surface plasmon resonance effects. However, including nanoparticles into Organic Solar Cells has shown to adversely affect the performance of the devices in other ways, such as increasing the recombination of excitons. To address this, an additional (insulating) coating around the nanoparticles supresses this increase, and has shown to be able to increase the performance of the solar cells. In this work, we demonstrate the use of our all-inclusive optical model in the design and optimisation of bespoke colour-specific windows (i.e. Red, Green, and Blue), where the solar cells can be made to have a specific transparency and colour, whilst maximizing their efficiency. For example, we could specify that we wish the colour to be red, with 50% transmissivity; the model will then maximise the Power Conversion Efficiency. We also demonstrate how our extension to Mie theory can simulate nanoparticle systems and can be used to tune the plasmon resonance utilising different coatings, and configurations thereof.
DIY Solar Market Analysis Webinar Series: Solar Resource and Technical
Series: Solar Resource and Technical Potential DIY Solar Market Analysis Webinar Series: Solar Resource and Technical Potential Wednesday, June 11, 2014 As part of a Do-It-Yourself Solar Market Analysis summer series, NREL's Solar Technical Assistance Team (STAT) presented a live webinar titled, "Solar
Utilising Fine and Coarse Recycled Aggregates from the Gulf Region in Concrete
NASA Astrophysics Data System (ADS)
Jones, M. Rod; Halliday, Judith E.; Csetenyi, Laszlo; Zheng, Li; Strompinis, N.
This paper explores the feasibility in utilising materials generated from C&DW to produce a `green' concrete. The two materials that are considered here are, (i) up-sizing silt-size material generated from recycled aggregates to produce a synthetic silt-sand and (ii) processed recycled coarse aggregates (RA) sourced from a Gulf Region landfill site. The work has demonstrated that there is potential for utilising silt wastes into foamed concrete, which can then be crushed to a sand-sized material suitable for use in concrete, however the porous nature of the material has highlighted that the water demand of this RA is high. RAs were characterised to BS EN 12620 and found suitable for use in concrete. The effect of RA on concrete properties is minimal when used up to 35% replacement levels, provided that they are pre-soaked.
Solar potential scaling and the urban road network topology
NASA Astrophysics Data System (ADS)
Najem, Sara
2017-01-01
We explore the scaling of cities' solar potentials with their number of buildings and reveal a latent dependence between the solar potential and the length of the corresponding city's road network. This scaling is shown to be valid at the grid and block levels and is attributed to a common street length distribution. Additionally, we compute the buildings' solar potential correlation function and length in order to determine the set of critical exponents typifying the urban solar potential universality class.
Sustainable Electricity and Water for Europe, Middle East and North Africa
NASA Astrophysics Data System (ADS)
Müller-Steinhagen, H.; Trieb, F.
2009-04-01
Sufficient supply of energy and water are among the key requirements for a sustainable development of nations. Both depend strongly on energy carriers such as oil, gas, coal and uranium which have limited availability and a negative impact on the environment during their use. Within the framework of a series of detailed studies, conventional and renewable energy sources available for electricity production and desalination in Europe, North Africa and the Middle East (EU-MENA) have been analysed. Scenarios have been developed for a sustainable electricity supply based on increased plant and user efficiency, and an accelerated introduction of renewable energy sources. Even if all potential exclusion criteria are applied and only those technologies are considered which will become economically competitive within the next decades, a potential has been identified which exceeds the present electricity demand by orders of magnitude. Solar energy is, in this context, the by far largest resource which will most economically be exploited in centralised solar thermal power plants. In combination with heat storage, these power plants can provide bulk and peak electricity, and can be combined with thermal or reverse osmosis desalination plants. At present, solar thermal power plants with a total capacity exceeding 10 GW are in operation or under construction in Abu Dhabi, Algeria, Egypt, Iran, Israel, Italy, Morocco, Spain and the USA. Ultimately, the increasing electricity demand of EU-MENA can only be secured in conjunction with the required climate and resource protection targets, if all renewable energy sources are exploited where appropriate, and conversion and user efficiency are increased. To utilise the enormous energy resources of the Mediterranean countries, high voltage direct current power lines will have to be built, linking the most abundant and economic resources with the load centres in the North. With electricity losses below 10% over a distance of 3000 km, HVDC lines may provide up to 15% of the total European electricity demand by 2050. For the MENA region, this scenario will provide most promising opportunities: in addition to the export of electricity replacing revenues from dwindling oil and gas resources, solar thermal power plants will provide a major share of their own electricity demands at competitive costs and will provide fresh water by seawater desalination, the latter becoming an urgent requirement over the next decades. This presentation outlines the assumptions and results of the studies which have been performed by an international consortium for 50 EU-MENA countries, as well as the technological and economic implications of the suggested scenario.
New ways of working in theatres. Three session working days.
Collins, Gill
2006-01-01
Innovative ideas will be required to meet government targets for the health service in the future. Increasing the number of hours available to surgical teams from two to three sessions could be one solution. Efficient and effective utilisation of a huge capital resource would appear to be further justification for increased hours, although the Audit Commission suggests that improving existing utilisation rather than extending hours should be the priority. However if operating sessions could be increased from two to three there is a potential to reduce waiting lists.
The Distribution and Behaviour of Photospheric Magnetic Features
NASA Astrophysics Data System (ADS)
Parnell, C. E.; Lamb, D. A.; DeForest, C. E.
2014-12-01
Over the past two decades enormous amounts of data on the magnetic fields of the solar photosphere have been produced by both ground-based (Kitt Peak & SOLIS), as well as space-based instruments (MDI, Hinode & HMI). In order to study the behaviour and distribution of photospheric magnetic features, efficient automated detection routines need to be utilised to identify and track magnetic features. In this talk, I will discuss the pros and cons of different automated magnetic feature identification and tracking routines with a special focus on the requirements of these codes to deal with the large data sets produced by HMI. By patching together results from Hinode and MDI (high-res & full-disk), the fluxes of magnetic features were found to follow a power-law over 5 orders of magnitude. At the strong flux tail of this distribution, the power law was found to fall off at solar minimum, but was maintained over all fluxes during solar maximum. However, the point of deflection in the power-law distribution occurs at a patching point between instruments and so questions remain over the reasons for the deflection. The feature fluxes determined from the superb high-resolution HMI data covers almost all of the 5 orders of magnitude. Considering both solar mimimum and solar maximum HMI data sets, we investigate whether the power-law over 5 orders of magnitude in flux still holds. Furthermore, we investigate the behaviour of magnetic features in order to probe the nature of their origin. In particular, we analyse small-scale flux emergence events using HMI data to investigate the existence of a small-scale dynamo just below the solar photosphere.
van Huyssteen, Mea; Milne, Pieter J; Campbell, Eileen E; van de Venter, Maryna
2011-01-01
Diabetes mellitus is a growing problem in South Africa and of concern to traditional African health practitioners in the Nelson Mandela Metropole, because they experience a high incidence of diabetic cases in their practices. A collaborative research project with these practitioners focused on the screening of Bulbine frutescens, Ornithogalum longibracteatum, Ruta graveolens, Tarchonanthus camphoratus and Tulbaghia violacea for antidiabetic and cytotoxic potential. In vitro glucose utilisation assays with Chang liver cells and C2C12 muscle cells, and growth inhibition assays with Chang liver cells were conducted. The aqueous extracts of Bulbine frutescens (143.5%), Ornithogalum longibracteatum (131.9%) and Tarchonanthus camphoratus (131.5%) showed significant increased glucose utilisation activity in Chang liver cells. The ethanol extracts of Ruta graveolens (136.9%) and Tulbaghia violacea (140.5%) produced the highest increase in glucose utilisation in C2C12 muscle cells. The ethanol extract of Bulbine frutescens produced the most pronounced growth inhibition (33.3%) on Chang liver cells. These findings highlight the potential for the use of traditional remedies in the future for the management of diabetes and it is recommended that combinations of these plants be tested in future.
Córdoba-Doña, Juan Antonio; Escolar-Pujolar, Antonio; San Sebastián, Miguel; Gustafsson, Per E
2018-01-01
Scant research is available on the impact of the current economic crisis and austerity policies on inequality in health services utilisation in Europe. This study aimed to describe the trends in horizontal inequity in the use of health services in Andalusia, Spain, during the early years of the Great Recession, and the contribution of demographic, economic and social factors. Consultation with a general practitioner (GP) and specialist, hospitalisation and emergency care were studied through the Andalusian Health Survey 2007 (pre-crisis) and 2011-2012 (crisis), using a composite income index as socioeconomic status (SES) indicator. Horizontal inequity indices (HII) were calculated to take differential healthcare needs into account, and a decomposition analysis of change in inequality between periods was performed. Results showed that before the crisis, the HII was positive (greater access for people with higher SES) for specialist visits but negative (greater access for people with lower SES) in the other three utilisation models. During the crisis no change was observed in inequalities in GP visits, but a pro-poor development was seen for the other types of utilisation, with hospital and emergency care showing significant inequality in favour of low income groups. Overall, the main contributors to pro-poor changes in utilisation were socio-economic variables and poor mental health, due to changes in their elasticities. Our findings show that inequalities in healthcare utilisation largely remained in favour of the less well-off, despite the cuts in welfare benefits and health services provision during the early years of the recession in Andalusia. Further research is needed to monitor the potential impact of such measures in subsequent years.
2018-01-01
Scant research is available on the impact of the current economic crisis and austerity policies on inequality in health services utilisation in Europe. This study aimed to describe the trends in horizontal inequity in the use of health services in Andalusia, Spain, during the early years of the Great Recession, and the contribution of demographic, economic and social factors. Consultation with a general practitioner (GP) and specialist, hospitalisation and emergency care were studied through the Andalusian Health Survey 2007 (pre-crisis) and 2011–2012 (crisis), using a composite income index as socioeconomic status (SES) indicator. Horizontal inequity indices (HII) were calculated to take differential healthcare needs into account, and a decomposition analysis of change in inequality between periods was performed. Results showed that before the crisis, the HII was positive (greater access for people with higher SES) for specialist visits but negative (greater access for people with lower SES) in the other three utilisation models. During the crisis no change was observed in inequalities in GP visits, but a pro-poor development was seen for the other types of utilisation, with hospital and emergency care showing significant inequality in favour of low income groups. Overall, the main contributors to pro-poor changes in utilisation were socio-economic variables and poor mental health, due to changes in their elasticities. Our findings show that inequalities in healthcare utilisation largely remained in favour of the less well-off, despite the cuts in welfare benefits and health services provision during the early years of the recession in Andalusia. Further research is needed to monitor the potential impact of such measures in subsequent years. PMID:29601609
Exploring the Transformative Potential of Bluetooth Beacons in Higher Education
ERIC Educational Resources Information Center
McDonald, Kieran; Glover, Ian
2016-01-01
The growing ubiquity of smartphones and tablet devices integrated into personal, social and professional life, facilitated by expansive communication networks globally, has the potential to disrupt higher education. Academics and students are considering the future possibilities of exploiting these tools and utilising networks to consolidate and…
Rebraiding Photovoice: Methodological Métissage at the Cultural Interface
ERIC Educational Resources Information Center
Higgins, Marc
2014-01-01
Photovoice, the most prevalent participatory visual research methodology utilised within social science research, has begun making its way into Indigenous contexts in light of its critical and pedagogical potential. However, this potential is not always actualised as the assumptions that undergird photovoice are often the same ones that…
Environmental aspects of the geothermal energy utilisation in Poland
NASA Astrophysics Data System (ADS)
Sowiżdżał, Anna; Tomaszewska, Barbara; Drabik, Anna
2017-11-01
Geothermal energy is considered as a strategic and sustainable source of renewable energy that can be effectively managed in several economic sectors. In Poland, despite the abundant potential of such resources, its share in the energy mix of renewable energy sources remains insubstantial. The utilisation of geothermal resources in Poland is related to the hydrogeothermal resources, however, numerous researches related to petrogeothermal energy resources are being performed. The utilisation of each type of energy, including geothermal, has an impact on the natural environment. In case of the effective development of geothermal energy resources, many environmental benefits are pointed out. The primary one is the extraction of clean, green energy that is characterised by the zero-emission rate of pollutants into the atmosphere, what considering the current environmental pollution in many Polish cities remains the extremely important issue. On the other hand, the utilisation of geothermal energy might influence the natural environment negatively. Beginning from the phase of drilling, which strongly interferes with the local landscape or acoustic climate, to the stage of energy exploitation. It should be noted that the efficient and sustainable use of geothermal energy resources is closely linked with the current law regulations at national and European level.
Environmental assessment of incinerator residue utilisation.
Toller, S; Kärrman, E; Gustafsson, J P; Magnusson, Y
2009-07-01
Incineration ashes may be treated either as a waste to be dumped in landfill, or as a resource that is suitable for re-use. In order to choose the best management scenario, knowledge is needed on the potential environmental impact that may be expected, including not only local, but also regional and global impact. In this study, A life cycle assessment (LCA) based approach was outlined for environmental assessment of incinerator residue utilisation, in which leaching of trace elements as well as other emissions to air and water and the use of resources were regarded as constituting the potential environmental impact from the system studied. Case studies were performed for two selected ash types, bottom ash from municipal solid waste incineration (MSWI) and wood fly ash. The MSWI bottom ash was assumed to be suitable for road construction or as drainage material in landfill, whereas the wood fly ash was assumed to be suitable for road construction or as a nutrient resource to be recycled on forest land after biofuel harvesting. Different types of potential environmental impact predominated in the activities of the system and the use of natural resources and the trace element leaching were identified as being relatively important for the scenarios compared. The scenarios differed in use of resources and energy, whereas there is a potential for trace element leaching regardless of how the material is managed. Utilising MSWI bottom ash in road construction and recycling of wood ash on forest land saved more natural resources and energy than when these materials were managed according to the other scenarios investigated, including dumping in landfill.
Rooftop Solar Technical Potential for Low-to-Moderate Income Households in the United States
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sigrin, Benjamin O; Mooney, Meghan E
This report presents a first-of-kind assessment of the technical potential of rooftop solar for low and moderate-income households, as well as providing insight on the distribution of solar potential by tenure, income, and other building characteristics. We find that a substantial fraction of the national rooftop solar potential is located on LMI buildings and, for all incomes, a substantial fraction on multi-family and renter-occupied buildings. We also find that rooftop solar can significantly contribute to long-term penetration targets established by the U.S. DOE, though to do so requires deployment on multi-family and renter-occupied buildings. Traditional deployment models have insufficiently enabledmore » access to solar for these income groups and building types. Without innovation either in regulatory, market, or policy factors, a large fraction of the U.S. potential is unlikely to be addressed, as well as leading to inequalities in solar access. Ironically, potential electric bill savings from rooftop solar would have the greatest material impact on the lives of low-income households as compared to their high-income counterparts.« less
Rooftop Solar Technical Potential for Low-to-Moderate Income (LMI) Households
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sigrin, Benjamin O
This report presents a first-of-kind assessment of the technical potential of rooftop solar for low and moderate-income households, as well as providing insight on the distribution of solar potential by tenure, income, and other building characteristics. We find that a substantial fraction of the national rooftop solar potential is located on LMI buildings and, for all incomes, a substantial fraction on multi-family and renter-occupied buildings. We also find that rooftop solar can significantly contribute to long-term penetration targets established by the U.S. DOE, though to do so requires deployment on multi-family and renter-occupied buildings. Traditional deployment models have insufficiently enabledmore » access to solar for these income groups and building types. Without innovation either in regulatory, market, or policy factors, a large fraction of the U.S. potential is unlikely to be addressed, as well as leading to inequalities in solar access. Ironically, potential electric bill savings from rooftop solar would have the greatest material impact on the lives of low-income households as compared to their high-income counterparts.« less
Assessment of Greenhouse Gas Control Technology Options within the Energy, Water and Food Nexus
NASA Astrophysics Data System (ADS)
Al-Ansari, Tareq; Korre, Anna; Nie, Zhenggang; Shah, Nilay
2015-04-01
The utilisation of Energy, Water and Food (EWF) resources can be described as a nexus of complex linkages embodied in industrial and natural processes. Food production is one such example of a system that mobilises EWF resources to deliver a product which is highly influenced by the efficiency of the industrial processes contributing to it and the conditions of the surrounding natural environment. Aggregating the utilisation of EWF resources into interconnected sub-systems is necessary for the accurate representation of the system's dynamics in terms of its material flow and resource consumption. The methodology used in this study is an extension of previous work developed regarding nexus analysis (Al-Ansari et al. 2014a, Al-Ansari et al. 2014b). Life cycle assessment (LCA) is used to prepare detailed models of the sub-system components, determine the linkages between the different nexus constituents and evaluate impacts on the natural environment. The nexus system is comprised of water sub-systems represented by a reverse osmosis (RO) desalination process. Energy sub-systems for power generation include models for a combined cycle gas turbine (CCGT) and solar Photovoltaics (PV) energy generation, as well as an amine based CO2 capture process enabling the utilisation of CO2 for the artificial fertilization of crops. The agricultural sub-systems include the production and application of fertilizers and the raising of livestock. A biomass integrated gasification combined cycle (BIGCC) for power generation using waste manure from the livestock sub-system is also included. The objective of this study is to consider a conventional food system in Qatar and enhance its environmental performance by using a nexus approach to examine different scenarios and operating modes. For the Qatar case study, three scenarios and four modes of operation were developed as part of the analysis. The baseline scenario uses fossil fuel to power the entire EWF nexus system using CCGT, the second scenario integrates PV to power the RO units and the third scenario uses solar PV to power the RO and fertilizer production facilities. The second operating mode integrates the BIGCC for power generation and the third mode utilises the gasification by-product biochar for the enhancement of agricultural productivity in addition to the power generated from the BIGCC. The final mode of operation examines the use of CO2 capture technology in the baseline scenario to support fertilization resulting in productivity increases for crops. References: Al-Ansari, T., Korre, A., Nie, Z., Shah, N., "Development of a life cycle assessment model for the analysis of the energy, water and food nexus" Computer Aided Chemical Engineering, 33, (2014), 1039-1044. Al-Ansari, T., Korre, A., Nie, Z., Shah, N., Integrated Modelling of the Energy, Water and Food Nexus to Enhance the Environmental Performance of Food Production Systems, 9th International Conference LCA of Food, San Francisco, USA, 8 - 10 October 2014
A fast isogeometric BEM for the three dimensional Laplace- and Helmholtz problems
NASA Astrophysics Data System (ADS)
Dölz, Jürgen; Harbrecht, Helmut; Kurz, Stefan; Schöps, Sebastian; Wolf, Felix
2018-03-01
We present an indirect higher order boundary element method utilising NURBS mappings for exact geometry representation and an interpolation-based fast multipole method for compression and reduction of computational complexity, to counteract the problems arising due to the dense matrices produced by boundary element methods. By solving Laplace and Helmholtz problems via a single layer approach we show, through a series of numerical examples suitable for easy comparison with other numerical schemes, that one can indeed achieve extremely high rates of convergence of the pointwise potential through the utilisation of higher order B-spline-based ansatz functions.
Physical Limits of Solar Energy Conversion in the Earth System.
Kleidon, Axel; Miller, Lee; Gans, Fabian
2016-01-01
Solar energy provides by far the greatest potential for energy generation among all forms of renewable energy. Yet, just as for any form of energy conversion, it is subject to physical limits. Here we review the physical limits that determine how much energy can potentially be generated out of sunlight using a combination of thermodynamics and observed climatic variables. We first explain how the first and second law of thermodynamics constrain energy conversions and thereby the generation of renewable energy, and how this applies to the conversions of solar radiation within the Earth system. These limits are applied to the conversion of direct and diffuse solar radiation - which relates to concentrated solar power (CSP) and photovoltaic (PV) technologies as well as biomass production or any other photochemical conversion - as well as solar radiative heating, which generates atmospheric motion and thus relates to wind power technologies. When these conversion limits are applied to observed data sets of solar radiation at the land surface, it is estimated that direct concentrated solar power has a potential on land of up to 11.6 PW (1 PW=10(15) W), whereas photovoltaic power has a potential of up to 16.3 PW. Both biomass and wind power operate at much lower efficiencies, so their potentials of about 0.3 and 0.1 PW are much lower. These estimates are considerably lower than the incoming flux of solar radiation of 175 PW. When compared to a 2012 primary energy demand of 17 TW, the most direct uses of solar radiation, e.g., by CSP or PV, have thus by far the greatest potential to yield renewable energy requiring the least space to satisfy the human energy demand. Further conversions into solar-based fuels would be reduced by further losses which would lower these potentials. The substantially greater potential of solar-based renewable energy compared to other forms of renewable energy simply reflects much fewer and lower unavoidable conversion losses when solar radiation is directly converted into renewable energy.
Life-cycle energy impacts for adapting an urban water supply system to droughts.
Lam, Ka Leung; Stokes-Draut, Jennifer R; Horvath, Arpad; Lane, Joe L; Kenway, Steven J; Lant, Paul A
2017-12-15
In recent years, cities in some water stressed regions have explored alternative water sources such as seawater desalination and potable water recycling in spite of concerns over increasing energy consumption. In this study, we evaluate the current and future life-cycle energy impacts of four alternative water supply strategies introduced during a decade-long drought in South East Queensland (SEQ), Australia. These strategies were: seawater desalination, indirect potable water recycling, network integration, and rainwater tanks. Our work highlights the energy burden of alternative water supply strategies which added approximately 24% life-cycle energy use to the existing supply system (with surface water sources) in SEQ even for a current post-drought low utilisation status. Over half of this additional life-cycle energy use was from the centralised alternative supply strategies. Rainwater tanks contributed an estimated 3% to regional water supply, but added over 10% life-cycle energy use to the existing system. In the future scenario analysis, we compare the life-cycle energy use between "Normal", "Dry", "High water demand" and "Design capacity" scenarios. In the "Normal" scenario, a long-term low utilisation of the desalination system and the water recycling system has greatly reduced the energy burden of these centralised strategies to only 13%. In contrast, higher utilisation in the unlikely "Dry" and "Design capacity" scenarios add 86% and 140% to life-cycle energy use of the existing system respectively. In the "High water demand" scenario, a 20% increase in per capita water use over 20 years "consumes" more energy than is used by the four alternative strategies in the "Normal" scenario. This research provides insight for developing more realistic long-term scenarios to evaluate and compare life-cycle energy impacts of drought-adaptation infrastructure and regional decentralised water sources. Scenario building for life-cycle assessments of water supply systems should consider i) climate variability and, therefore, infrastructure utilisation rate, ii) potential under-utilisation for both installed centralised and decentralised sources, and iii) the potential energy penalty for operating infrastructure well below its design capacity (e.g., the operational energy intensity of the desalination system is three times higher at low utilisation rates). This study illustrates that evaluating the life-cycle energy use and intensity of these type of supply sources without considering their realistic long-term operating scenario(s) can potentially distort and overemphasise their energy implications. To other water stressed regions, this work shows that managing long-term water demand is also important, in addition to acknowledging the energy-intensive nature of some alternative water sources. Copyright © 2017 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Lin, E. I. H.
1982-01-01
A comprehensive assessment of the regional applicability and potential of salt-gradient solar ponds in the United States is provided. The assessment is focused on the general characteristics of twelve defined geographic regions. Natural resources essential to solar ponds are surveyed. Meteorological and hydrogeological conditions affecting pond performance are examined. Potentially favorable pond sites are identified. Regional thermal and electrical energy output from solar ponds is calculated. Selected pond design cases are studied. Five major potential market sectors are evaluated in terms of technical and energy-consumption characteristics, and solar-pond applicability and potential. Relevant pond system data and financial factors are analyzed. Solar-pond energy costs are compared with conventional energy costs. The assessment concludes that, excepting Alaska, ponds are applicable in all regions for at least two market sectors. Total solar pond energy supply potential in the five market sectors examined is estimated to be 8.94 quads/yr by the year 2000, approximately 7.2% of the projected total national energy demand.
NASA Astrophysics Data System (ADS)
Lin, E. I. H.
1982-03-01
A comprehensive assessment of the regional applicability and potential of salt-gradient solar ponds in the United States is provided. The assessment is focused on the general characteristics of twelve defined geographic regions. Natural resources essential to solar ponds are surveyed. Meteorological and hydrogeological conditions affecting pond performance are examined. Potentially favorable pond sites are identified. Regional thermal and electrical energy output from solar ponds is calculated. Selected pond design cases are studied. Five major potential market sectors are evaluated in terms of technical and energy-consumption characteristics, and solar-pond applicability and potential. Relevant pond system data and financial factors are analyzed. Solar-pond energy costs are compared with conventional energy costs. The assessment concludes that, excepting Alaska, ponds are applicable in all regions for at least two market sectors. Total solar pond energy supply potential in the five market sectors examined is estimated to be 8.94 quads/yr by the year 2000, approximately 7.2% of the projected total national energy demand.
Development of advanced Si and GaAs solar cells for interplanetary missions
NASA Technical Reports Server (NTRS)
Strobl, G.; Uegele, P.; Kern, R.; Roy, K.; Flores, C.; Campesato, R.; Signorini, C.; Bogus, K.
1995-01-01
The deep space and planetary exploration project have been acquiring more and more importance and some of them are now well established both in ESA and NASA programs. This paper presents the possibility to utilize both silicon and gallium arsenide solar cells as spacecraft primary power source for missions far from the Sun, in order to overcome the drawbacks related to the utilisation of radioisotope thermoelectric generators - such as cost, safety and social acceptance. The development of solar cells for low illumination intensity and low temperature (LILT) applications is carried out in Europe by ASE (Germany) and CISE (Italy) in the frame of an ESA programme, aimed to provide the photovoltaic generators for ROSETTA: the cometary material investigation mission scheduled for launch in 2003. The LILT cells development and testing objectives are therefore focused on the following requirements: insolation intensity as low as 0.03 Solar Constant, low temperature down to -150 C and solar flare proton environment. At this stage of development, after the completion of the technology verification tests, it has been demonstrated that suitable technologies are available for the qualification of both silicon and gallium arsenide cells and both candidates have shown conversion efficiencies over 25% at an illumination of 0.03 SC and a temperature of -150 C. In particular, when measured at those LILT conditions, the newly developed 'Hl-ETA/NR-LILT' silicon solar cells have reached a conversion efficiency of 26.3%, that is the highest value ever measured on a single junction solar cell. A large quantity of both 'Hl-ETA/NR-LILT' silicon and 'GaAs/Ge-LILT' solar cells are presently under fabrication and they will be submitted to a qualification test plan, including radiation exposure, in order to verify their applicability with respect to the mission requirements. The availability of two valid options will minimize the risk for the very ambitious scientific project. The paper describes how the technical achievements have been possible with Si and GaAs LILT solar cells (including a comparison between measured and modelled l-V characteristics) and it presents the technology verification tests results.
Development of advanced Si and GaAs solar cells for interplanetary missions
NASA Astrophysics Data System (ADS)
Strobl, G.; Uegele, P.; Kern, R.; Roy, K.; Flores, C.; Campesato, R.; Signorini, C.; Bogus, K.
1995-10-01
The deep space and planetary exploration project have been acquiring more and more importance and some of them are now well established both in ESA and NASA programs. This paper presents the possibility to utilize both silicon and gallium arsenide solar cells as spacecraft primary power source for missions far from the Sun, in order to overcome the drawbacks related to the utilisation of radioisotope thermoelectric generators - such as cost, safety and social acceptance. The development of solar cells for low illumination intensity and low temperature (LILT) applications is carried out in Europe by ASE (Germany) and CISE (Italy) in the frame of an ESA programme, aimed to provide the photovoltaic generators for ROSETTA: the cometary material investigation mission scheduled for launch in 2003. The LILT cells development and testing objectives are therefore focused on the following requirements: insolation intensity as low as 0.03 Solar Constant, low temperature down to -150 C and solar flare proton environment. At this stage of development, after the completion of the technology verification tests, it has been demonstrated that suitable technologies are available for the qualification of both silicon and gallium arsenide cells and both candidates have shown conversion efficiencies over 25% at an illumination of 0.03 SC and a temperature of -150 C. In particular, when measured at those LILT conditions, the newly developed 'Hl-ETA/NR-LILT' silicon solar cells have reached a conversion efficiency of 26.3%, that is the highest value ever measured on a single junction solar cell. A large quantity of both 'Hl-ETA/NR-LILT' silicon and 'GaAs/Ge-LILT' solar cells are presently under fabrication and they will be submitted to a qualification test plan, including radiation exposure, in order to verify their applicability with respect to the mission requirements. The availability of two valid options will minimize the risk for the very ambitious scientific project. The paper describes how the technical achievements have been possible with Si and GaAs LILT solar cells (including a comparison between measured and modelled l-V characteristics) and it presents the technology verification tests results.
Automated identification and tracking of polar-cap plasma patches at solar minimum
NASA Astrophysics Data System (ADS)
Burston, R.; Hodges, K.; Astin, I.; Jayachandran, P. T.
2014-03-01
A method of automatically identifying and tracking polar-cap plasma patches, utilising data inversion and feature-tracking methods, is presented. A well-established and widely used 4-D ionospheric imaging algorithm, the Multi-Instrument Data Assimilation System (MIDAS), inverts slant total electron content (TEC) data from ground-based Global Navigation Satellite System (GNSS) receivers to produce images of the free electron distribution in the polar-cap ionosphere. These are integrated to form vertical TEC maps. A flexible feature-tracking algorithm, TRACK, previously used extensively in meteorological storm-tracking studies is used to identify and track maxima in the resulting 2-D data fields. Various criteria are used to discriminate between genuine patches and "false-positive" maxima such as the continuously moving day-side maximum, which results from the Earth's rotation rather than plasma motion. Results for a 12-month period at solar minimum, when extensive validation data are available, are presented. The method identifies 71 separate structures consistent with patch motion during this time. The limitations of solar minimum and the consequent small number of patches make climatological inferences difficult, but the feasibility of the method for patches larger than approximately 500 km in scale is demonstrated and a larger study incorporating other parts of the solar cycle is warranted. Possible further optimisation of discrimination criteria, particularly regarding the definition of a patch in terms of its plasma concentration enhancement over the surrounding background, may improve results.
NASA Astrophysics Data System (ADS)
R, C. K.; Bhushan, R.; Agnihotri, R.; Sawlani, R.; Jull, A. J. T.
2016-12-01
Seawaters and underlying sediments off Sri Lanka provide a unique marine realm affected by both branches of Northern Indian Ocean i.e. Arabian Sea (AS) and Bay of Bengal (BOB). AS and BOB are known for their distinct response to southwest monsoon. AS experiencing mainly winds and upwelling while BOB receives precipitation driven surface runoff from the Indian sub-continent. Multiple proxies were measured on a radiocarbon dated sediment core raised off Sri Lanka; their down core variations were used to understand oceanic history (nutrient utilisation, surface productivity, nature of organic matter) spanning last glacial-interglacial cycle ( 26 to 2.5 ka BP). Variations in CaCO3, biogenic silica (BSi) and δ15N from 26 ka to 12.5 ka BP indicate the region was experiencing high surface productivity with probably reduced surface nutrient utilisation efficiency. Sedimentary δ15N depth profile is decoupled from down core variations of major productivity indices (e.g. CaCO3, OC), hinting plausibly partial utilization of nutrients in the mixed layer (photic zone). δ13C of OC and C/N (wt. ratio) clearly reveal the terrestrial origin of organic matter at 15 ka BP, a period known for witnessing onset of deglaciation in northern hemisphere. δ13C minimum at 9 ka BP indicates intense monsoonal activity during this time coinciding well with solar insolation (June) maximum of the northern hemisphere. With the onset of Holocene ( 11 ka BP), δ15N variations appear to correlate with BSi and Ba/Ti indicating enhanced utilization of available nutrients at surface. Suggesting surface productivity over the region was probably micro-nutrient limited. The increased inventory of terrestrial runoff in Holocene probably demonstrates enhanced carbon sequestration capability of the region.
Benson, Sarah J; Lennard, Christopher J; Maynard, Philip; Hill, David M; Andrew, Anita S; Roux, Claude
2009-06-01
An evaluation was undertaken to determine if isotope ratio mass spectrometry (IRMS) could assist in the investigation of complex forensic cases by providing a level of discrimination not achievable utilising traditional forensic techniques. The focus of the research was on ammonium nitrate (AN), a common oxidiser used in improvised explosive mixtures. The potential value of IRMS to attribute Australian AN samples to the manufacturing source was demonstrated through the development of a preliminary AN classification scheme based on nitrogen isotopes. Although the discrimination utilising nitrogen isotopes alone was limited and only relevant to samples from the three Australian manufacturers during the evaluated time period, the classification scheme has potential as an investigative aid. Combining oxygen and hydrogen stable isotope values permitted the differentiation of AN prills from three different Australian manufacturers. Samples from five different overseas sources could be differentiated utilising a combination of the nitrogen, oxygen and hydrogen isotope values. Limited differentiation between Australian and overseas prills was achieved for the samples analysed. The comparison of nitrogen isotope values from intact AN prill samples with those from post-blast AN prill residues highlighted that the nitrogen isotopic composition of the prills was not maintained post-blast; hence, limiting the technique to analysis of un-reacted explosive material.
Henriques de Jesus, E; Correia Martins, M C
1998-01-01
The propose of this communication is to describe the present nursing situation in Madeira (RAM) and its potentialities for the utilisation of the Information Technologies and Communications (I.T.C.) in educational and in clinical practice. RAM has its own Regional Health System and is developing a Health Information System, a Nursing Education System which conglobates a Baccalaureate Nursing School and a Licentiate's degree Nursing School which graduates almost the totality of the nurses who work here in Madeira, a Health Professional Education Department, common to the different organisations and a Regional Nursing Research Group constituted by elements representing the several organisations of health and which has been developing Research Education and dynamize Research Projects in nursing practice. The Nursing Schools in addition to the Health Organisation, use the Nursing Theoretical Models and the Nursing Process since 1990 Referring to the utilisation of the ITC in Education and in the Clinical Practice, despite the school curricula include informatics subjects, nurse's knowledge and opportunities of utilisation are still too incipient. Nevertheless, the present reform of the baccalaureate course curriculum as well as the aims and strategies of the Nursing Research Group and training strategies will provide positive changes.
Recent Advances in Developing Insect Natural Products as Potential Modern Day Medicines
Ratcliffe, Norman; Azambuja, Patricia; Mello, Cicero Brasileiro
2014-01-01
Except for honey as food, and silk for clothing and pollination of plants, people give little thought to the benefits of insects in their lives. This overview briefly describes significant recent advances in developing insect natural products as potential new medicinal drugs. This is an exciting and rapidly expanding new field since insects are hugely variable and have utilised an enormous range of natural products to survive environmental perturbations for 100s of millions of years. There is thus a treasure chest of untapped resources waiting to be discovered. Insects products, such as silk and honey, have already been utilised for thousands of years, and extracts of insects have been produced for use in Folk Medicine around the world, but only with the development of modern molecular and biochemical techniques has it become feasible to manipulate and bioengineer insect natural products into modern medicines. Utilising knowledge gleaned from Insect Folk Medicines, this review describes modern research into bioengineering honey and venom from bees, silk, cantharidin, antimicrobial peptides, and maggot secretions and anticoagulants from blood-sucking insects into medicines. Problems and solutions encountered in these endeavours are described and indicate that the future is bright for new insect derived pharmaceuticals treatments and medicines. PMID:24883072
Rashid, A; Warnakulasuriya, S
2015-05-01
In recent decades, optical techniques utilising the principles of chemiluminescence and tissue autofluorescence have emerged to facilitate the early detection of any oral mucosal changes suspicious of cancer. To evaluate the effectiveness of devices that utilise the principles of chemiluminescence and tissue autofluorescence as adjuncts in the detection of oral cancer and oral potentially malignant disorders (OPMDs). A systematic review of the published literature to evaluate the effectiveness of the ViziLite(®) and ViziLite(®) Plus with toluidine blue, MicroLux™/DL and the VELscope™ as aids in the detection of oral cancer and OPMDs. Twenty-five primary studies published between 2004 and 2013 satisfied our criteria for selection - 13 utilised chemiluminescence and 12 tissue autofluorescence. Some had utilised both study methods on the same population. Chemiluminescence shows good sensitivity at detecting any OPMDs and oral cancer. However, it preferentially detects leukoplakia and may fail to spot red patches. The additive use of toluidine blue may improve specificity. Tissue autofluorescence is sensitive at detecting white, red and white and red patches, and the area of fluorescence visualisation loss (FVL) often extends beyond the clinically visible lesion. However, in addition to OPMDs, VELScope may detect erythematous lesions of benign inflammation resulting in false-positive test results. There is limited evidence for their use in primary care, and these tools are better suited to specialist clinics in which there is a higher prevalence of disease and where experienced clinicians may better discriminate between benign and malignant lesions. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Khan, Aamar F; Brownson, Dale A C; Foster, Christopher W; Smith, Graham C; Banks, Craig E
2017-05-21
Surfactant exfoliated 2D hexagonal Boron Nitride (2D-hBN) nanosheets are explored as a potential electrochemical sensing platform and evaluated towards the electroanalytical sensing of dopamine (DA) in the presence of the common interferents, ascorbic acid (AA) and uric acid (UA). Surfactant exfoliated 2D-hBN nanosheets (2-4 layers) fabricated using sodium cholate in aqueous media are electrically wired via a drop-casting modification process onto disposable screen-printed graphite electrodes (SPEs). We critically evaluate the performance of these 2D-hBN modified SPEs and demonstrate the effect of 'mass coverage' towards the detection of DA, AA and UA. Previous studies utilising surfactant-free (pristine) 2D-hBN modified SPEs have shown a beneficial effect towards the detection of DA, AA and UA when compared to the underlying/unmodified graphite-based electrode. We show that the fabrication route utilised to prepare 2D-hBN is a vital experimental consideration, such that the beneficial effect previously reported is considerably reduced when surfactant exfoliated 2D-hBN is utilised. We demonstrate for the first time, through implementation of control experiments in the form of surfactant modified graphite electrodes, that sodium cholate is a major contributing factor to the aforementioned detrimental behaviour. The significance here is not in the material per se, but the fundamental knowledge of the surfactant and surface coverage changing the electrochemical properties of the material under investigation. Given the wide variety of ionic and non-ionic surfactants that are utilised in the manufacture of novel 2D materials, the control experiments reported herein need to be performed in order to de-convolute the electrochemical response and effectively evaluate the 'underlying surface/surfactant/2D materials' electrocatalytic contribution.
Bozorgmehr, Kayvan; Schneider, Christine; Joos, Stefanie
2015-11-09
Research on inequities in access to health care among asylum-seekers has focused on disparities between asylum-seekers and resident populations, but little attention has been paid to potential inequities in access to care within the group of asylum-seekers. We aimed to analyse the principles of horizontal equity (i.e., equal access for equal need irrespective of socioeconomic status, SES) and vertical equity (higher allocation of resources to those with higher need) among asylum-seekers in Germany. We performed a secondary exploratory analysis on cross-sectional data obtained from a population-based questionnaire survey among all asylum-seekers (aged 18 or above) registered in three administrative districts in Germany during the three-month study period (N = 1017). Data were collected on health care access (health care utilisation of four types of services and unmet medical need), health care need (approximated by sex, age and self-rated health status), and SES (highest educational attainment and subjective social status, SSS). We calculated odds ratios and 95% confidence intervals (CI) in multiple logistic regression models to analyse associations between SES indicators and access to health care under control of need. We contacted 60.4% (614) of the total asylum-seekers population, of which 25.4% (N = 156) participated in the study. Educational attainment showed no significant effect on health care access in crude models, but was positively associated with utilisation of psychotherapists and hospital admissions in adjusted models. Higher SSS was positively associated with health care utilisation of all types of services. The odds of hospitals admissions for asylum-seekers in the medium and highest SSS category were 3.18 times [1.06, 9.59] and 1.6 times [0.49, 5.23] the odds of those in the lowest SSS category. After controlling for need variables none of the SES indicators were significantly associated with measures of access to care, but a positive association remained, indicating higher utilisation of health care among asylum-seekers with higher SES. Age, sex or general health status were the only significant predictors of health care utilisation in fully adjusted models. The adjusted odds of reporting unmet medical needs among asylum-seekers with "fair/bad/very bad" health status were 2.16 times [0.84, 5.59] the odds of those with "good/very good" health status. Our findings revealed that utilisation of health services among asylum-seekers is associated with higher need (vertical equity met). Horizontal equity was met with respect to educational attainment for most outcomes, but a social gradient in health care utilisation was observed across SSS. Further confirmatory research is needed, especially on potential inequities in unmet medical need and on measurements of SES among asylum-seekers.
Qian-Yuan, Wu; Chao, Li; Ye, Du; Wen-Long, Wang; Huang, Huang; Hong-Ying, Hu
2016-05-15
Ecological storage of reclaimed water in ponds and lakes is widely applied in water reuse. During reclaimed water storage, solar light can degrade pollutants and improve water quality. This study investigated the effects of solar light irradiation on the disinfection byproduct formation potential in reclaimed water, including haloacetonitriles (HANs), trichloronitromethane (TCNM), trihalomethanes (THMs), haloketones (HKs) and chloral hydrate (CH). Natural solar light significantly decreased the formation potential of HANs, TCNM, and HKs in reclaimed water, but had a limited effect on the formation potential of THMs and CH. Ultraviolet (UV) light in solar radiation played a dominant role in the decrease of the formation potential of HANs, TCNM and HKs. Among the disinfection byproducts, the removal kinetic constant of dichloroacetonitrile (DCAN) with irradiation dose was much larger than those for dichloropropanone (1,1-DCP), trichloropropanone (1,1,1-TCP) and TCNM. During solar irradiation, fluorescence spectra intensities of reclaimed water also decreased significantly. The removal of tyrosine (Tyr)-like and tryptophan (Trp)-like protein fluorescence spectra intensity volumes was correlated to the decrease in DCAN formation potential. Solar irradiation was demonstrated to degrade Trp, Tyr and their DCAN formation potential. The photolysis products of Trp after solar irradiation were detected as kynurenine and tryptamine, which had chloroform, CH and DCAN formation potential lower than those of Trp. Copyright © 2016. Published by Elsevier Ltd.
Energy from biomass — Some basic physical and related considerations
NASA Astrophysics Data System (ADS)
Gloyne, R. W.
1983-09-01
The production of vegetable matter (biomass) by photosynthesis is determined by species and by meteorological factors (especially, but not exclusively, solar radiation). Annual net primary production of land-based biomass corresponds to only about 1/1000 of the intercepted irradiation at ground level, but even so, is 10 times the world's estimated energy needs. The exploitation of this energy potential at any one place is critically influenced by the economic, political and social factors, amongst which are the competition from agriculture (especially food crops), forestry, industrial and urban (including leisure) needs for land and resources. Social factors (e.g. population and population density) also constitute prime influences. Strategies for utilisation range from the cultivation of special energy crops (readily conceivable on the American/ Australasian continents); to the more efficient manipulation of current land-use patterns (including “opportunity” cropping); to the more effective exploitation of biologi cal wastes (e.g. methane from sewage), probably the only immediately practical possibility in any densely populated and highly industrialised country. The spatial pattern of solar irradiation at ground level is complex. In the summer, total daily irradiation in continental high latitudes can exceed that in maritime temperate regions; and this combined with species differences and the almost infinite variety of shape and orientation of plant parts, result in a photosynthetic production of biomass which does not conform completely to a zonal pattern, but in broad terms annual dry matter production varies from a few kg/ha in Arctic Tundra to tens of tonnes in temperate latitudes rising to nearly 100 t/ha for perennial tropical crops. If a species could be developed to grow throughout the year at the current seasonal rate, a yield of 150 t/yr, ha) seems possible.
Improving sputum microscopy services for the diagnosis of tuberculosis in Peru and Bolivia.
Siddiqi, K; Newell, J N; Van der Stuyft, P; Gotuzzo, E; Torrico, F; Van Deun, A; Walley, J
2007-06-01
Sixteen primary care health centres in Peru and Bolivia. To assess the utilisation of microscopy services in Peru and Bolivia and determine if clinical audit, a quality improvement tool, improves the utilisation of these services. We estimated the percentage of patients with suspected tuberculosis (TB) in whom sputum microscopy was effectively utilised in Peru and Bolivia over two 6-month periods before and after a clinical audit intervention that included standards setting, measuring clinical performance and feedback. Before the intervention, only 31% (95%CI 27-35) of TB suspects were assessed with sputum microscopy in Peru. In Bolivia, 30% (95%CI 25-35) underwent at least two sputum microscopy examinations. After clinical audit, the availability of sputum microscopy results improved by respectively 7% (95%CI 1-12, P < 0.05) and 23% (95%CI 15-30, P < 0.05) over 2 years in Peru and Bolivia. Despite World Health Organization recommendations that all TB suspects should undergo sputum microscopy before treatment, results are available for further assessment for only one third. This is a potentially serious obstacle to TB case detection. Clinical audit can bring some improvement. We recommend regular monitoring of effective utilisation of microscopy services and investigations to ascertain organisational and structural issues in their uptake and use.
Breet, Elsie; Bantjes, Jason; Lewis, Ian
2018-03-06
Substance use is a potentially modifiable risk factor for suicidal behaviour. Little is known about the epidemiology of substance use among self-harm patients in South Africa. This study set out to collect epidemiological data about the prevalence, correlates, and patterns of medical service utilisation among self-harm patients who used substances at the time of self-injury. Data from 238 consecutive self-harm patients treated at an urban hospital in South Africa were analysed using bivariate and multivariate statistics. Approximately 20% of patients reported substance use at the time of self-harm. When compared to other self-harm patients, higher rates of patients who had used substances: had depressed levels of consciousness on admission; utilised more medical resources and required longer hospital admissions; cited relationship difficulties and financial concerns as reasons for their self-harm; reported a previous episode of self-harm; and intended to die as a result of their injuries. Although the observed differences were not statistically significant (p > 0.05), the proportional differences were congruent with international literature. Acute use of substances among self-harm patients warrants more focused research and clinical attention particularly in the context of reducing utilisation of scarce medical resources.
Health seeking behaviour and challenges in utilising health facilities in Wakiso district, Uganda.
Musoke, David; Boynton, Petra; Butler, Ceri; Musoke, Miph Boses
2014-12-01
The health seeking behaviour of a community determines how they use health services. Utilisation of health facilities can be influenced by the cost of services, distance to health facilities, cultural beliefs, level of education and health facility inadequacies such as stock-out of drugs. To assess the health seeking practices and challenges in utilising health facilities in a rural community in Wakiso district, Uganda. The study was a cross sectional survey that used a structured questionnaire to collect quantitative data among 234 participants. The sample size was obtained using the formula by Leslie Kish. While 89% of the participants were aware that mobile clinics existed in their community, only 28% had received such services in the past month. The majority of participants (84%) did not know whether community health workers existed in their community. The participants' health seeking behaviour the last time they were sick was associated with age (p = 0.028) and occupation (p = 0.009). The most significant challenges in utilising health services were regular stock-out of drugs, high cost of services and long distance to health facilities. There is potential to increase access to health care in rural areas by increasing the frequency of mobile clinic services and strengthening the community health worker strategy.
Tan, Si Ying; Wu, Xun; Yang, Wei
2018-05-08
While moving towards unified social health insurance (SHI) is often a politically popular policy reform in countries where rapid expansion in health insurance coverage has given rise to the segmentation of SHI systems as different SHI schemes were rolled out to serve different populations, the potential impacts of reform on service utilisation and health costs have not been systematically studied. Using data from the Chinese Health and Retirement Longitudinal Study (CHARLS), we compared the mean costs incurred for both inpatient and outpatient care under different health insurance schemes, and the impact of different SHI schemes on treatment utilisation and health care costs using a two-part model. Our results show that Urban Employee Medical Insurance, which offers the most generous benefits, incurs the highest total costs prior to reimbursement when compared to other SHI schemes. Our analysis also shows that utilisation of SHI did not show significant reduction in out-of-pocket payments for outpatients. We argue that, unless effective measures are introduced to deal with perverse provider payment incentives, the move towards a unified system with more generous benefits may usher in a new wave of cost escalation for health care systems in China.
Controlling chromium slag pollution utilising scavengers: a case of Shandong Province, China.
Liu, Changhao; Côté, Raymond P
2015-04-01
The problem of chromium slag pollution is a great challenge for China. It is now an urgent task for China to take effective measures to eliminate chromium slag pollution. This article examines the case of the treatment of chromium slag in Shandong Province and explores how chromium slag pollution can be eliminated in Shandong Province. It shows that the chromium slag stockpiled by the chemical plants was successfully utilised by local steel companies, who act as 'scavenger companies'. The driving mechanism, seeking a potential 'scavenger company' within the local region and the role of the local government on the case of Shandong Province are discussed. This article concludes that local steel companies can be utilised to effectively and efficiently treat the chromium slag while benefiting the steel companies. The local governments need to play multiple roles in solving the problem of chromium slag pollution. Seeking and identifying 'scavenger companies' within a region could be an important approach to reducing pollution within the region. © The Author(s) 2015.
The effects of new pricing and copayment schemes for pharmaceuticals in South Korea.
Lee, Iyn-Hyang; Bloor, Karen; Hewitt, Catherine; Maynard, Alan
2012-01-01
This study examined the effect of new Korean pricing and copayment schemes for pharmaceuticals (1) on per patient drug expenditure, utilisation and unit prices of overall pharmaceuticals; (2) on the utilisation of essential medications and (3) on the utilisation of less costly alternatives to the study medication. Interrupted time series analysis using retrospective observational data. The increasing trend of per patient drug expenditure fell gradually after the introduction of a new copayment scheme. The segmented regression model suggested that per patient drug expenditure might decrease by about 12% 1 year after the copayment increase, compared with the absence of such a policy, with few changes in overall utilisation and unit prices. The level of savings was much smaller when the new price scheme was included, while the effects of a price cut were inconclusive due to the short time period before an additional policy change. Based on the segmented regression models, we estimate that the number of patients filling their antihyperlipidemics prescriptions decreased by 18% in the corresponding period. Those prescribed generic and brand-named antihyperlipidemics declined by around 16 and 19%, respectively, indicating little evidence of generic substitution resulting from the copayment increase. Few changes were found in the use of antihypertensives. The policies under consideration appear to contain costs not by the intended mechanisms, such as substituting generics for brand name products, but by reducing patients' access to costly therapies regardless of clinical necessity. Thus, concerns were raised about potentially compromising overall health and loss of equity in pharmaceutical utilisation. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Characteristics of coal mine ventilation air flows.
Su, Shi; Chen, Hongwei; Teakle, Philip; Xue, Sheng
2008-01-01
Coal mine methane (CMM) is not only a greenhouse gas but also a wasted energy resource if not utilised. Underground coal mining is by far the most important source of fugitive methane emissions, and approximately 70% of all coal mining related methane is emitted to the atmosphere through mine ventilation air. Therefore, research and development on mine methane mitigation and utilisation now focuses on methane emitted from underground coal mines, in particular ventilation air methane (VAM) capture and utilisation. To date, most work has focused on the oxidation of very low concentration methane. These processes may be classified based on their combustion kinetic mechanisms into thermal oxidation and catalytic oxidation. VAM mitigation/utilisation technologies are generally divided into two basic categories: ancillary uses and principal uses. However, it is possible that the characteristics of ventilation air flows, for example the variations in methane concentration and the presence of certain compounds, which have not been reported so far, could make some potential VAM mitigation and utilisation technologies unfeasible if they cannot cope with the characteristics of mine site ventilation air flows. Therefore, it is important to understand the characteristics of mine ventilation air flows. Moreover, dust, hydrogen sulphide, sulphur dioxide, and other possible compounds emitted through mine ventilation air into the atmosphere are also pollutants. Therefore, this paper presents mine-site experimental results on the characteristics of mine ventilation air flows, including methane concentration and its variations, dust loadings, particle size, mineral matter of the dust, and other compounds in the ventilation air flows. The paper also discusses possible correlations between ventilation air characteristics and underground mining activities.
Shared Solar. Current Landscape, Market Potential, and the Impact of Federal Securities Regulation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Feldman, David; Brockway, Anna M.; Ulrich, Elaine
2015-04-07
This report provides a high-level overview of the current U.S. shared solar landscape, the impact that a given shared solar program’s structure has on requiring federal securities oversight, as well as an estimate of market potential for U.S. shared solar deployment.
Shared Solar. Current Landscape, Market Potential, and the Impact of Federal Securities Regulation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Feldman, David; Brockway, Anna M.; Ulrich, Elaine
2015-04-01
This report provides a high-level overview of the current U.S. shared solar landscape and the impact that a given shared solar program’s structure has on requiring federal securities oversight, as well as an estimate of market potential for U.S. shared solar deployment.
Highly efficient and autocatalytic H2₂ dissociation for CO₂ reduction into formic acid with zinc.
Jin, Fangming; Zeng, Xu; Liu, Jianke; Jin, Yujia; Wang, Lunying; Zhong, Heng; Yao, Guodong; Huo, Zhibao
2014-03-28
Artificial photosynthesis, specifically H2O dissociation for CO2 reduction with solar energy, is regarded as one of the most promising methods for sustainable energy and utilisation of environmental resources. However, a highly efficient conversion still remains extremely challenging. The hydrogenation of CO2 is regarded as the most commercially feasible method, but this method requires either exotic catalysts or high-purity hydrogen and hydrogen storage, which are regarded as an energy-intensive process. Here we report a highly efficient method of H2O dissociation for reducing CO2 into chemicals with Zn powder that produces formic acid with a high yield of approximately 80%, and this reaction is revealed for the first time as an autocatalytic process in which an active intermediate, ZnH(-) complex, serves as the active hydrogen. The proposed process can assist in developing a new concept for improving artificial photosynthetic efficiency by coupling geochemistry, specifically the metal-based reduction of H2O and CO2, with solar-driven thermochemistry for reducing metal oxide into metal.
Highly efficient and autocatalytic H2O dissociation for CO2 reduction into formic acid with zinc
Jin, Fangming; Zeng, Xu; Liu, Jianke; Jin, Yujia; Wang, Lunying; Zhong, Heng; Yao, Guodong; Huo, Zhibao
2014-01-01
Artificial photosynthesis, specifically H2O dissociation for CO2 reduction with solar energy, is regarded as one of the most promising methods for sustainable energy and utilisation of environmental resources. However, a highly efficient conversion still remains extremely challenging. The hydrogenation of CO2 is regarded as the most commercially feasible method, but this method requires either exotic catalysts or high-purity hydrogen and hydrogen storage, which are regarded as an energy-intensive process. Here we report a highly efficient method of H2O dissociation for reducing CO2 into chemicals with Zn powder that produces formic acid with a high yield of approximately 80%, and this reaction is revealed for the first time as an autocatalytic process in which an active intermediate, ZnH− complex, serves as the active hydrogen. The proposed process can assist in developing a new concept for improving artificial photosynthetic efficiency by coupling geochemistry, specifically the metal-based reduction of H2O and CO2, with solar-driven thermochemistry for reducing metal oxide into metal. PMID:24675820
2D black phosphorous nanosheets as a hole transporting material in perovskite solar cells
NASA Astrophysics Data System (ADS)
Muduli, Subas Kumar; Varrla, Eswaraiah; Kulkarni, Sneha Avinash; Han, Guifang; Thirumal, Krishnamoorthy; Lev, Ovadia; Mhaisalkar, Subodh; Mathews, Nripan
2017-12-01
We demonstrate for the first-time liquid exfoliated few layers of 2D Black phosphorus (BP) nanosheets as a hole transporting material (HTM) for perovskite based solar cells. The photoelectron spectroscopy in air (PESA) measurements confirm the low laying valence band level of BP nanosheets (-5.2 eV) favourable for hole injection from CH3NH3PbI3 (MAPbI3). Our results show that ∼25% improvement in power conversion efficiency (PCE) of η = 16.4% for BP nanosheets + Spiro-OMeTAD as an HTM as compared to spiro-OMeTAD (η = 13.1%). When BP nanosheets are exclusively utilised as an HTM, a PCE of η = 7.88% is noted, an improvement over the 4% PCE values observed for HTM free devices. Photoluminescence (PL) quenching of MAPbI3 and impedance measurements further confirm the charge extraction ability of BP nanosheets. The structural and optical characterization of liquid exfoliated BP nanosheets is discussed in detail with the aid of transmission electron microscopy, Raman spectroscopy, absorption spectroscopy and photo-electron spectroscopy.
[Frequency of use of school cafeterias in middle and high schools in 3 French districts].
Michaud, C; Feur, E; Gerbouin-Rérolle, P; Leynaud-Rouaud, C; Chateil, S; Gourdon, M
2000-09-01
Reports from the French Ministry of Education warn of a decrease in the use of school food services, especially in sensitive urban areas. They also suggest that this decline has led to cases of malnutrition. This article describes the characteristics of the current supply of school meals and measures the evolution of demand observed between 1992 and 1996 in relation to the economic situation of students' families. The study was carried out in 3 departments in France: Doubs, Herault, and Val de Marne. The administrators of all public and private middle and high schools in the 3 departments received a questionnaire asking them to describe the services offered in their cafeterias and to provide the corresponding statistical and accounting data. External food services near the schools were also taken into account. Seventy-nine percent of schools responded to the survey. Concerning the services offered, 91% of schools have their own cafeterias, of which 81% are managed by the schools. Concerning the evolution of utilisation, a significant decrease in the number of meals served in seen in middle schools. On the other hand, high schools have observed stable utilisation. The positive changes in utilisation are linked, in middle schools, to characteristics of the schools' internal food services (self-service, choice of main courses, modulation of seats). In high schools, positive changes in the utilisation of school services are linked to the lack of external food services near the schools. As middle schools and high schools control the logistics and management of food services offered to students, they are potentially in a position to influence a policy on this issue. The evolution in utilisation is very different among departments and between middle and high schools. While economic precariousness has a negative structural effect on utilisation, it doesn't seem to be a major factor in the evolution of the decrease observed over the past few years.
Studies of solar flares: Homology and X-ray line broadening
NASA Astrophysics Data System (ADS)
Ranns, Neale David Raymond
This thesis starts with an introduction to the solar atmosphere and the physics that governs its behaviour. The formation processes of spectral lines are presented followed by an explanation of employed plasma diagnostic techniques and line broadening mechanisms. The current understanding on some principle concepts of flare physics are reviewed and the topics of flare homology and non-thermal line broadening are introduced. The many solar satellites and instrumentation that were utilised during this thesis are described. Analysis techniques for some instruments are also presented. A series of solar flares that conform to the literature definition for homologous flares are examined. The apparent homology is shown to be caused by emerging flux rather than continual stressing of a single, or group of, magnetic structure's. The implications for flare homology are discussed. The analysis of a solar flare with a rise and peak in the observed non-thermal X-ray line broadening (Vnt) is then performed. The location of the hot plasma within the flare area is determined and consequently the source of Vnt is located to be within and above the flare loops. The flare footpoints are therefore discarded as a possible source location. Viable source locations are discussed with a view to determining the dominant mechanism for the generation of line broadening. The timing relationships between the hard X-ray (HXR) flux and Vnt in many solar flares are then examined. I show that there is a causal relationship between these two parameters and that the HXR rise time is related to the time delay between the maxima of HXR flux and Vnt. The temporal evolution of Vnt is shown to be dependent upon the shape of the HXR burst. The implications of these results are discussed in terms of determining the line broadening mechanism and the limitations of the data. A summary of the results in this thesis is then presented together with suggestions for future research.
Solar Technical Assistance Team 2013 Webinars | State, Local, and Tribal
following sessions are available: Solar Finance for Residential and Commercial Customers and Potential Roles Requests for Proposal Solar Finance for Residential and Commercial Customers and Potential Roles of State residential and commercial solar projects are financed and the various roles that state and local governments
Planetary habitability: is Earth commonplace in the Milky Way?
NASA Astrophysics Data System (ADS)
Franck, S.; Block, A.; Bloh, W.; Bounama, C.; Garrido, I.; Schellnhuber, H.-J.
2001-08-01
Is there life beyond planet Earth? This is one of the grand enigmas which humankind tries to solve through scientific research. Recent progress in astronomical measurement techniques has confirmed the existence of a multitude of extra-solar planets. On the other hand, enormous efforts are being made to assess the possibility of life on Mars. All these activities have stimulated several investigations about the habitability of cosmic bodies. The habitable zone (HZ) around a given central star is defined as the region within which an Earth-like planet might enjoy the moderate surface temperatures required for advanced life forms. At present, there are several models determining the HZ. One class of models utilises climate constraints for the existence of liquid water on a planetary surface. Another approach is based on an integrated Earth system analysis that relates the boundaries of the HZ to the limits of photosynthetic processes. Within the latter approach, the evolution of the HZ for our solar system over geological time scales is calculated straightforwardly, and a convenient filter can be constructed that picks the candidates for photosynthesis-based life from all the extra-solar planets discovered by novel observational methods. These results can then be used to determine the average number of planets per planetary system that are within the HZ. With the help of a segment of the Drake equation, the number of "Gaias" (i.e. extra-solar terrestrial planets with a globally acting biosphere) is estimated. This leads to the thoroughly educated guess that there should exist half a million Gaias in the Milky Way.
Planetary habitability: is Earth commonplace in the Milky Way?
Franck, S; Block, A; von Bloh, W; Bounama, C; Garrido, I; Schellnhuber, H J
2001-10-01
Is there life beyond planet Earth? This is one of the grand enigmas which humankind tries to solve through scientific research. Recent progress in astronomical measurement techniques has confirmed the existence of a multitude of extra-solar planets. On the other hand, enormous efforts are being made to assess the possibility of life on Mars. All these activities have stimulated several investigations about the habitability of cosmic bodies. The habitable zone (HZ) around a given central star is defined as the region within which an Earth-like planet might enjoy the moderate surface temperatures required for advanced life forms. At present, there are several models determining the HZ. One class of models utilises climate constraints for the existence of liquid water on a planetary surface. Another approach is based on an integrated Earth system analysis that relates the boundaries of the HZ to the limits of photosynthetic processes. Within the latter approach, the evolution of the HZ for our solar system over geological time scales is calculated straightforwardly, and a convenient filter can be constructed that picks the candidates for photosynthesis-based life from all the extra-solar planets discovered by novel observational methods. These results can then be used to determine the average number of planets per planetary system that are within the HZ. With the help of a segment of the Drake equation, the number of "Gaias" (i.e. extra-solar terrestrial planets with a globally acting biosphere) is estimated. This leads to the thoroughly educated guess that there should exist half a million Gaias in the Milky Way.
NASA Astrophysics Data System (ADS)
Kumar, K. Ravi; Cheepu, Muralimohan; Srinivas, B.; Venkateswarlu, D.; Pramod Kumar, G.; Shiva, Apireddi
2018-03-01
In solar air heater, artificial roughness on absorber plate become prominent technique to improving heat transfer rate of air flowing passage as a result of laminar sublayer. The selection of rib geometries plays important role on friction characteristics and heat transfer rate. Many researchers studying the roughness shapes over the years to investigate the effect of geometries on the performance of friction factor and heat transfer of the solar air heater. The present study made an attempt to develop the different rib shapes utilised for creating artificial rib roughness and its comparison to investigate higher performance of the geometries. The use of computational fluid dynamics software resulted in correlation of friction factor and heat transfer rate. The simulations studies were performed on 2D computational fluid dynamics model and analysed to identify the most effective parameters of relative roughness of the height, width and pitch on major considerations of friction factor and heat transfer. The Reynolds number is varied in a range from 3000 to 20000, in the current study and modelling has conducted on heat transfer and turbulence phenomena by using Reynolds number. The modelling results showed the formation of strong vortex in the main stream flow due to the right angle triangle roughness over the square, rectangle, improved rectangle and equilateral triangle geometries enhanced the heat transfer extension in the solar air heater. The simulation of the turbulence kinetic energy of the geometry suggests the local turbulence kinetic energy has been influenced strongly by the alignments of the right angle triangle.
NASA Astrophysics Data System (ADS)
Paudyal, D. R.; McDougall, K.; Apan, A.
2012-07-01
The participation and engagement of grass-root level community groups and citizens for natural resource management has a long history. With recent developments in ICT tools and spatial technology, these groups are seeking a new opportunity to manage natural resource data. There are lot of spatial information collected/generated by landcare groups, land holders and other community groups at the grass-root level through their volunteer initiatives. State government organisations are also interested in gaining access to this spatial data/information and engaging these groups to collect spatial information under their mapping programs. The aim of this paper is to explore the possible utilisation of volunteered geographic information (VGI) for catchment management activities. This research paper discusses the importance of spatial information and spatial data infrastructure (SDI) for catchment management and the emergence of VGI. A conceptual framework has been developed to illustrate how these emerging spatial information applications and various community volunteer activities can contribute to a more inclusive spatial data infrastructure (SDI) development at local level. A survey of 56 regional NRM bodies in Australia was utilised to explore the current community-driven volunteer initiatives for NRM activities and the potential of utilisation of VGI initiatives for NRM decision making process. This research paper concludes that VGI activities have great potential to contribute to SDI development at the community level to achieve better natural resource management (NRM) outcomes.
Thieme, Holm; Borgetto, Bernhard
2012-01-01
Physical Therapy (PT) and self-help groups (SHG) are important components of health care in rheumatic diseases. The utilisation of PT and SHG by patients with rheumatic diseases may be influenced by several factors. The aim of this study is to summarize the evidence on PT and SHG utilisation of patients with rheumatic diseases in Germany. We systematically searched the MEDLINE-database for studies that evaluated the utilisation and factors that possibly influence the utilisation of PT and SHG. Eight studies were found for PT-utilisation and one for SHG-utilisation. Between 25 and 59 percent of patients with rheumatic diseases received PT services. Several individual and contextual factors that may influence the utilisation could be identified. In conclusion, evidence exists for wide variations in the utilisation of PT services and an underuse of such services among patients with rheumatic diseases in Germany. By contrast, little evidence exists on the utilisation of SHG.
Extraterrestrial applications of solar optics for interior illumination
NASA Technical Reports Server (NTRS)
Eijadi, David A.; Williams, Kyle D.
1992-01-01
Solar optics is a terrestrial technology that has potential extraterrestrial applications. Active solar optics (ASO) and passive solar optics (PSO) are two approaches to the transmission of sunlight to remote interior spaces. Active solar optics is most appropriate for task illumination, while PSO is most appropriate for general illumination. Research into solar optics, motivated by energy conservation, has produced lightweight and low-cost materials, products that have applications to NASA's Controlled Ecological Life Support System (CELSS) program and its lunar base studies. Specifically, prism light guides have great potential in these contexts. Several applications of solar optics to lunar base concepts are illustrated.
Use of solar cell in electrokinetic remediation of cadmium-contaminated soil.
Yuan, Songhu; Zheng, Zhonghua; Chen, Jing; Lu, Xiaohua
2009-03-15
This preliminary study used a solar cell, instead of direct current (DC) power supply, to generate electric field for electrokinetic (EK) remediation of cadmium-contaminated soil. Three EK tests were conducted and compared; one was conducted on a cloudy and rainy day with solar cell, one was conducted on a sunny day with solar cell and another was conducted periodically with DC power supply. It was found that the output potential of solar cell depended on daytime and was influenced by weather conditions; the applied potential in soil was affected by the output potential and weather conditions, and the current achieved by solar cell was comparable with that achieved by DC power supply. Solar cell could be used to drive the electromigration of cadmium in contaminated soil, and removal efficiency achieved by solar cell was comparable with that achieved by DC power supply. Compared with traditional DC power supply, using solar cell as power supply for EK remediation can greatly reduce energy expenditure. This study provided an alternative to improve the EK soil remediation and expanded the use of solar cell in environmental remediation.
Solar Pond Potential as A New Renewable Energy in South Sulawesi
NASA Astrophysics Data System (ADS)
Fadliah Baso, Nur; Chaerah Gunadin, Indar; Yusran
2018-03-01
Renewable energy sources need to be developed to maintain the electric energy availability by utilizing oceanic energy, namely solar pond energy. This energy is highly influenced by several factors including salinity, air temperature and solar radiation. This study was focused on finding the potential of solar pond in South Sulawesi, a region with fairly high solar radiation and abundant salt water raw materials availability. The method used in this study was analyzing the values from the mathematic models of daily horizontal solar radiation, air temperature, wind speed, relative humidity and atmospheric pressure for the last 22 years which were finalized using MATLAB. The findings of this study will show the areas with good potentials to apply solar pond in South Sulawesi that can be utilized in various fields including power generator, industrial heating process, desalination and heating for biomass conversion.
A rapid appraisal of access to and utilisation of psychotropic medicines in Bihar, India
2014-01-01
Background A major aspect of providing mental healthcare is access to and use of psychotropic medications. Bihar is a state in northeast India with limited mental healthcare provision; consequently access to and utilisation of psychotropic medications are likely to be limited. However, to date there has been no research assessing the situation. This study therefore aims to analyse the psychotropic medications management cycle (selection, procurement, distribution and use), and identify the barriers to access and utilisation, and their underlying causes. Method A rapid appraisal method was used in which primary and secondary data sources were collected and analysed. Semi-structured interviews were conducted with twenty-two stakeholders and twenty-one service users from the government, non-governmental organisation (NGO) and private sectors. The qualitative data collected was analysed using a comparative thematic approach. The research was supported by the NGOs BasicNeeds and Nav Bharat Jagriti Kendra. Results Availability, distance and cost were the main barriers to access and utilisation. At the medical college hospital level a lack of supply appears to be due to a discrepancy between orders made by the hospital and medications supplied by the manufacturers. At the primary health centre and district hospital level the main barrier is a cycle between lack of demand for treatments for mental illness by doctors and patients. Conclusion Further investigation and monitoring is necessary to ensure the availability of psychotropic medications at the medical college hospital level. In addition, implementation of the District Mental Health Programme is likely to address the access and utilisation barriers due to its potential to break the current cycle of lack of demand. PMID:25053976
Group-based education for patients with type 2 diabetes: a survey of Australian dietitians.
Odgers-Jewell, Kate; Isenring, Elisabeth A; Thomas, Rae; Reidlinger, Dianne P
2017-09-01
Group-based education has the potential to substantially improve the outcomes of individuals with type 2 diabetes mellitus (T2DM) and reduce the enormous burden that chronic diseases place on healthcare systems worldwide. Despite this proven effectiveness, the utilisation of group services for the management of T2DM by Australian dietitians is surprisingly low. This study surveyed a sample of 263 Australian dietitians to explore the utilisation of group-based education for T2DM, as well as dietitians' preferences for practice and training. The results of this study indicate that Australian dietitians are currently under-utilising group-based education programs for the management of T2DM, with the primary reasons identified as a lack of training provided to dietitians in the area, limited access to facilities suitable for conducting group education, the perceived poor cost-effectiveness of these programs, and the lack of evidence-based practice guidelines for the group-based management of persons with T2DM. Additionally, the majority of preferences for further training were for either face-to-face or web-based formal training conducted over 3-6h. Clear, evidence-based practice guidelines and training resources for group education for the management of T2DM are needed in order to encourage better utilisation of group-based education by Australian dietitians.
Renewable resources in the chemical industry--breaking away from oil?
Nordhoff, Stefan; Höcker, Hans; Gebhardt, Henrike
2007-12-01
Rising prices for fossil-based raw materials suggest that sooner or later renewable raw materials will, in principle, become economically viable. This paper examines this widespread paradigm. Price linkages like those seen for decades particularly in connection with petrochemical raw materials are now increasingly affecting renewable raw materials. The main driving force is the competing utilisation as an energy source because both fossil-based and renewable raw materials are used primarily for heat, electrical power and mobility. As a result, prices are determined by energy utilisation. Simple observations show how prices for renewable carbon sources are becoming linked to the crude oil price. Whether the application calls for sugar, starch, virgin oils or lignocellulose, the price for the raw material rises with the oil price. Consequently, expectations regarding price trends for fossil-based energy sources can also be utilised for the valuation of alternative processes. However, this seriously calls into question the assumption that a rising crude oil price will favour the economic viability of alternative products and processes based on renewable raw materials. Conversely, it follows that these products and processes must demonstrate economic viability today. Especially in connection with new approaches in white biotechnology, it is evident that, under realistic assumptions, particularly in terms of achievable yields and the optimisation potential of the underlying processes, the route to utilisation is economically viable. This makes the paradigm mentioned at the outset at least very questionable.
NASA Technical Reports Server (NTRS)
Willis, Emily M.; Minow, Joseph I.; Parker, Linda N.; Pour, Maria Z. A.; Swenson, Charles; Nishikawa, Ken-ichi; Krause, Linda Habash
2016-01-01
The International Space Station (ISS) continues to be a world-class space research laboratory after over 15 years of operations, and it has proven to be a fantastic resource for observing spacecraft floating potential variations related to high voltage solar array operations in Low Earth Orbit (LEO). Measurements of the ionospheric electron density and temperature along the ISS orbit and variations in the ISS floating potential are obtained from the Floating Potential Measurement Unit (FPMU). In particular, rapid variations in ISS floating potential during solar array operations on time scales of tens of milliseconds can be recorded due to the 128 Hz sample rate of the Floating Potential Probe (FPP) pro- viding interesting insight into high voltage solar array interaction with the space plasma environment. Comparing the FPMU data with the ISS operations timeline and solar array data provides a means for correlating some of the more complex and interesting transient floating potential variations with mission operations. These complex variations are not reproduced by current models and require further study to understand the underlying physical processes. In this paper we present some of the floating potential transients observed over the past few years along with the relevant space environment parameters and solar array operations data.
NASA Astrophysics Data System (ADS)
de Souza, Gabriel Fernandes; Tan, Lippong; Singh, Baljit; Ding, Lai Chet; Date, Abhijit
2017-04-01
The paper presents a sustainable hybrid system, which is capable of generating electricity and producing freshwater from seawater using low grade heat source. This proposed system uses low grade heat that can be supplied from solar radiation, industrial waste heat or any other waste heat sources where the temperature is less than 150°C. The concept behind this system uses the Seebeck effect for thermoelectricity generation via incorporating the low boiling point of seawater under sub-atmospheric ambient pressure. A lab-test prototype of the proposed system was built and experimentally tested in RMIT University. The prototype utilised four commercial available thermoelectric generators (Bi2Te3) and a vacuum vessel to achieve the simultaneous production of electricity and freshwater. The temperature profiles, thermoelectric powers and freshwater productions were determined at several levels of salinity to study the influence of different salt concentrations. The theoretical description of system design and experimental results were analysed and discussed in detailed. The experiment results showed that 0.75W of thermoelectricity and 404g of freshwater were produced using inputs of 150W of simulated waste heat and 500g of 3% saline water. The proposed hybrid concept has demonstrated the potential to become the future sustainable system for electricity and freshwater productions.
A method for evaluating photovoltaic potential in China based on GIS platform
NASA Astrophysics Data System (ADS)
Wang, L. Z.; Tan, H. W.; Ji, L.; Wang, D.
2017-11-01
Solar photovoltaic systems are commonly utilized in China. However, the associated research is still lack of its resource potential analysis in all regions in China. Based on the existed data about solar radiation and system conversion efficiency data, a new method for distributed photovoltaic potential assessment has been presented. The experiment of three kinds of solar photovoltaic system has been set up for the purpose of analyzing the relationship between conversion efficiency and environmental parameters. This paper fits the relationship between conversion efficiency and solar radiation intensity. This method takes into account the amount of solar radiation that is effectively generated and drives away the weak values. With the spatial analysis function of geographic information system (GIS) platform, frequency distribution of solar radiation intensity and PV potential in China can be derived. Furthermore, analytical results show that monocrystalline-silicon PV generation in the north-western and northern areas have reached a level of more than 200 kWh/(m2.a), making those areas be suitable for the development of PV system. However, the potential for southwest areas reaches a level of only 130 kWh/(m2.a). This paper can provide the baseline reference for solar energy development planning.
The Potential of Heat Collection from Solar Radiation in Asphalt Solar Collectors in Malaysia
NASA Astrophysics Data System (ADS)
Beddu, Salmia; Talib, Siti Hidayah Abdul; Itam, Zarina
2016-03-01
The implementation of asphalt solar collectors as a means of an energy source is being widely studied in recent years. Asphalt pavements are exposed to daily solar radiation, and are capable of reaching up to 70°C in temperature. The potential of harvesting energy from solar pavements as an alternative energy source in replace of non-renewable energy sources prone to depletion such as fuel is promising. In Malaysia, the sun intensity is quite high and for this reason, absorbing the heat from sun radiation, and then utilizing it in many other applications such as generating electricity could definitely be impressive. Previous researches on the different methods of studying the effect of heat absorption caused by solar radiation prove to be quite old and inaffective. More recent findings, on the otherhand, prove to be more informative. This paper focuses on determining the potential of heat collection from solar radiation in asphalt solar collectors using steel piping. The asphalt solar collector model constructed for this research was prepared in the civil engineering laboratory. The hot mixed asphalt (HMA) contains 10% bitumen mixed with 90% aggregates of the total size of asphalt. Three stainless steel pipes were embedded into the interior region of the model according to the design criteria, and then put to test. Results show that harvesting energy from asphalt solar collectors proves highly potential in Malaysia due its the hot climate.
On Feature Extraction from Large Scale Linear LiDAR Data
NASA Astrophysics Data System (ADS)
Acharjee, Partha Pratim
Airborne light detection and ranging (LiDAR) can generate co-registered elevation and intensity map over large terrain. The co-registered 3D map and intensity information can be used efficiently for different feature extraction application. In this dissertation, we developed two algorithms for feature extraction, and usages of features for practical applications. One of the developed algorithms can map still and flowing waterbody features, and another one can extract building feature and estimate solar potential on rooftops and facades. Remote sensing capabilities, distinguishing characteristics of laser returns from water surface and specific data collection procedures provide LiDAR data an edge in this application domain. Furthermore, water surface mapping solutions must work on extremely large datasets, from a thousand square miles, to hundreds of thousands of square miles. National and state-wide map generation/upgradation and hydro-flattening of LiDAR data for many other applications are two leading needs of water surface mapping. These call for as much automation as possible. Researchers have developed many semi-automated algorithms using multiple semi-automated tools and human interventions. This reported work describes a consolidated algorithm and toolbox developed for large scale, automated water surface mapping. Geometric features such as flatness of water surface, higher elevation change in water-land interface and, optical properties such as dropouts caused by specular reflection, bimodal intensity distributions were some of the linear LiDAR features exploited for water surface mapping. Large-scale data handling capabilities are incorporated by automated and intelligent windowing, by resolving boundary issues and integrating all results to a single output. This whole algorithm is developed as an ArcGIS toolbox using Python libraries. Testing and validation are performed on a large datasets to determine the effectiveness of the toolbox and results are presented. Significant power demand is located in urban areas, where, theoretically, a large amount of building surface area is also available for solar panel installation. Therefore, property owners and power generation companies can benefit from a citywide solar potential map, which can provide available estimated annual solar energy at a given location. An efficient solar potential measurement is a prerequisite for an effective solar energy system in an urban area. In addition, the solar potential calculation from rooftops and building facades could open up a wide variety of options for solar panel installations. However, complex urban scenes make it hard to estimate the solar potential, partly because of shadows cast by the buildings. LiDAR-based 3D city models could possibly be the right technology for solar potential mapping. Although, most of the current LiDAR-based local solar potential assessment algorithms mainly address rooftop potential calculation, whereas building facades can contribute a significant amount of viable surface area for solar panel installation. In this paper, we introduce a new algorithm to calculate solar potential of both rooftop and building facades. Solar potential received by the rooftops and facades over the year are also investigated in the test area.
Earth orbital assessment of solar electric and solar sail propulsion systems
NASA Technical Reports Server (NTRS)
Teeter, R. R.
1977-01-01
The earth orbital applications potential of Solar Electric (Ion Drive) and Solar Sail low-thrust propulsion systems are evaluated. Emphasis is placed on mission application in the 1980s. The two low-thrust systems are compared with each other and with two chemical propulsion Shuttle upper stages (the IUS and SSUS) expected to be available in the 1980s. The results indicate limited Earth orbital application potential for the low-thrust systems in the 1980s (primarily due to cost disadvantages). The longer term potential is viewed as more promising. Of the two systems, the Ion Drive exhibits better performance and appears to have better overall application potential.
Fantinati, P; Zannoni, A; Bernardini, C; Forni, M; Tattini, A; Seren, E; Bacci, M L
2009-02-01
In pig production, artificial insemination is widely carried out and the use of fresh diluted semen is predominant. For this reason, there are increasing interests in developing new extenders and in establishing the optimal storage conditions for diluted spermatozoa. In the last few decades, we utilised a homemade diluent (swine fertilisation medium (SFM)) for spermatozoa manipulation and biotechnological application as the production of transgenic pigs utilising the sperm-mediated gene transfer technique. The purpose of the present study is therefore to analyse the ability of SFM, in comparison to four commercial extenders, in preserving the quality of diluted boar semen stored at 16.5°C till 15 days. We utilised some of the main predictive tests as objectively measured motility, acrosome and sperm membrane integrity, high mitochondrial membrane potential and pH. Based on our in vitro study, SFM could be declared as a good long-term extender, able to preserve spermatozoa quality as well as Androhep Enduraguard for up to 6 to 9 days and more.
Calculating solar photovoltaic potential on residential rooftops in Kailua Kona, Hawaii
NASA Astrophysics Data System (ADS)
Carl, Caroline
As carbon based fossil fuels become increasingly scarce, renewable energy sources are coming to the forefront of policy discussions around the globe. As a result, the State of Hawaii has implemented aggressive goals to achieve energy independence by 2030. Renewable electricity generation using solar photovoltaic technologies plays an important role in these efforts. This study utilizes geographic information systems (GIS) and Light Detection and Ranging (LiDAR) data with statistical analysis to identify how much solar photovoltaic potential exists for residential rooftops in the town of Kailua Kona on Hawaii Island. This study helps to quantify the magnitude of possible solar photovoltaic (PV) potential for Solar World SW260 monocrystalline panels on residential rooftops within the study area. Three main areas were addressed in the execution of this research: (1) modeling solar radiation, (2) estimating available rooftop area, and (3) calculating PV potential from incoming solar radiation. High resolution LiDAR data and Esri's solar modeling tools and were utilized to calculate incoming solar radiation on a sample set of digitized rooftops. Photovoltaic potential for the sample set was then calculated with the equations developed by Suri et al. (2005). Sample set rooftops were analyzed using a statistical model to identify the correlation between rooftop area and lot size. Least squares multiple linear regression analysis was performed to identify the influence of slope, elevation, rooftop area, and lot size on the modeled PV potential values. The equations built from these statistical analyses of the sample set were applied to the entire study region to calculate total rooftop area and PV potential. The total study area statistical analysis findings estimate photovoltaic electric energy generation potential for rooftops is approximately 190,000,000 kWh annually. This is approximately 17 percent of the total electricity the utility provided to the entire island in 2012. Based on these findings, full rooftop PV installations on the 4,460 study area homes could provide enough energy to power over 31,000 homes annually. The methods developed here suggest a means to calculate rooftop area and PV potential in a region with limited available data. The use of LiDAR point data offers a major opportunity for future research in both automating rooftop inventories and calculating incoming solar radiation and PV potential for homeowners.
NASA Astrophysics Data System (ADS)
Gaos, Yogi Sirodz; Yulianto, Muhamad; Juarsa, Mulya; Nurrohman, Marzuki, Edi; Yuliaji, Dwi; Budiono, Kabul
2017-03-01
Indonesia is a tropical country that has potential energy of solar radiation worth of 4.5 until 4.8 kWh/m2. However, this potential has not been utilized regularly. This paper will discuss the performance of solar collector compound parabolic concentrator (CPC) type with water as the working fluid. This CPC solar collector utilized three pipes covered by glass tubes. This paper has contribution to provide the temperature achievement between three pipes covered by glass tubes with and without glass cover of solar collector CPC type. The research conducted by varying the water flow rate of 1 l/m up to 6 l/m with three pipes arranged in series and parallel. From the results, the used of solar collector CPC type in the current study shows that the decrease of solar radiation, which was caused by climate change, did not influence the heat absorbance by water in the pipe. Therefore, the design of the solar collector in this research has potential to be used in future when solar radiation are used as the energy source.
Everything under the Sun: A review of solar neutrinos
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gann, Gabriel D. Orebi
2015-07-15
Solar neutrinos offer a unique opportunity to study the interaction of neutrinos with matter, a sensitive search for potential new physics effects, and a probe of solar structure and solar system formation. This paper describes the broad physics program addressed by solar neutrino studies, presents the current suite of experiments programs, and describes several potential future detectors that could address the open questions in this field. This paper is a summary of a talk presented at the Neutrino 2014 conference in Boston.
Solar energy market penetration models - Science or number mysticism
NASA Technical Reports Server (NTRS)
Warren, E. H., Jr.
1980-01-01
The forecast market potential of a solar technology is an important factor determining its R&D funding. Since solar energy market penetration models are the method used to forecast market potential, they have a pivotal role in a solar technology's development. This paper critiques the applicability of the most common solar energy market penetration models. It is argued that the assumptions underlying the foundations of rigorously developed models, or the absence of a reasonable foundation for the remaining models, restrict their applicability.
Everything under the sun: A review of solar neutrinos
Gann, Gabriel D. Orebi
2015-07-15
Solar neutrinos offer a unique opportunity to study the interaction of neutrinos with matter, a sensitive search for potential new physics effects, and a probe of solar structure and solar system formation. This paper describes the broad physics program addressed by solar neutrino studies, presents the current suite of experiments programs, and describes several potential future detectors that could address the open questions in this field. This paper is a summary of a talk presented at the Neutrino 2014 conference in Boston.
Melander, A; Folino-Gallo, P; Walley, T; Schwabe, U; Groop, P-H; Klaukka, T; Vallano, A; Laporte, J-R; Gallego, M R; Schiappa, M; Røder, M; Kampmann, J P; de Swaef, A; Aberg, M; Månsson, N-O; Lindblad, U
2006-09-01
The aim of this study was to compare developments in the utilisation of antihyperglycaemic drugs (AHGDs) in ten European countries. Data on the yearly utilisation of insulin and oral AHGDs were collected from public registers in Denmark, Finland, Norway, Sweden, Belgium, England, Germany, Italy, Portugal and Spain, and were expressed as defined daily doses per 1,000 inhabitants per day. Total AGHD utilisation increased everywhere, but at different rates and levels. Insulin utilisation doubled in England and Germany, but hardly changed in Belgium, Portugal or Italy. Sulfonylurea utilisation doubled in Spain, England and Denmark but was reduced in Germany and Sweden. Metformin utilisation increased greatly everywhere. There were two- to three-fold differences in AHGD utilisation even between neighbouring countries. In Finland, there were more users of both insulin (+120%) and oral AHGDs (+80%) than in Denmark, and the daily oral AHGD doses were higher. In Denmark and Sweden, AHGD utilisation was equal in subjects aged <45 years, but in those >or=45 years of age, both insulin and oral AHGD utilisation were twice as high in Sweden. The ubiquitous increase in AHGD utilisation, particularly metformin, seems logical, considering the increasing prevalence of type 2 diabetes and the results of the UK Prospective Diabetes Study. However, the large differences even between neighbouring countries are more difficult to explain, and suggest different habits and attitudes in terms of screening and management of type 2 diabetes.
Deo, Ravinesh C; Downs, Nathan; Parisi, Alfio V; Adamowski, Jan F; Quilty, John M
2017-05-01
Exposure to erythemally-effective solar ultraviolet radiation (UVR) that contributes to malignant keratinocyte cancers and associated health-risk is best mitigated through innovative decision-support systems, with global solar UV index (UVI) forecast necessary to inform real-time sun-protection behaviour recommendations. It follows that the UVI forecasting models are useful tools for such decision-making. In this study, a model for computationally-efficient data-driven forecasting of diffuse and global very short-term reactive (VSTR) (10-min lead-time) UVI, enhanced by drawing on the solar zenith angle (θ s ) data, was developed using an extreme learning machine (ELM) algorithm. An ELM algorithm typically serves to address complex and ill-defined forecasting problems. UV spectroradiometer situated in Toowoomba, Australia measured daily cycles (0500-1700h) of UVI over the austral summer period. After trialling activations functions based on sine, hard limit, logarithmic and tangent sigmoid and triangular and radial basis networks for best results, an optimal ELM architecture utilising logarithmic sigmoid equation in hidden layer, with lagged combinations of θ s as the predictor data was developed. ELM's performance was evaluated using statistical metrics: correlation coefficient (r), Willmott's Index (WI), Nash-Sutcliffe efficiency coefficient (E NS ), root mean square error (RMSE), and mean absolute error (MAE) between observed and forecasted UVI. Using these metrics, the ELM model's performance was compared to that of existing methods: multivariate adaptive regression spline (MARS), M5 Model Tree, and a semi-empirical (Pro6UV) clear sky model. Based on RMSE and MAE values, the ELM model (0.255, 0.346, respectively) outperformed the MARS (0.310, 0.438) and M5 Model Tree (0.346, 0.466) models. Concurring with these metrics, the Willmott's Index for the ELM, MARS and M5 Model Tree models were 0.966, 0.942 and 0.934, respectively. About 57% of the ELM model's absolute errors were small in magnitude (±0.25), whereas the MARS and M5 Model Tree models generated 53% and 48% of such errors, respectively, indicating the latter models' errors to be distributed in larger magnitude error range. In terms of peak global UVI forecasting, with half the level of error, the ELM model outperformed MARS and M5 Model Tree. A comparison of the magnitude of hourly-cumulated errors of 10-min lead time forecasts for diffuse and global UVI highlighted ELM model's greater accuracy compared to MARS, M5 Model Tree or Pro6UV models. This confirmed the versatility of an ELM model drawing on θ s data for VSTR forecasting of UVI at near real-time horizon. When applied to the goal of enhancing expert systems, ELM-based accurate forecasts capable of reacting quickly to measured conditions can enhance real-time exposure advice for the public, mitigating the potential for solar UV-exposure-related disease. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Burch, J.; Thomas, K.E.
This study originated within the Solar Buildings Program at the U.S. Department of Energy. Its goal is to assess the potential for solar thermal water disinfection in developing countries. In order to assess solar thermal potential, the alternatives must be clearly understood and compared. The objectives of the study are to: (a) characterize the developing world disinfection needs and market; (b) identify competing technologies, both traditional and emerging; (c) analyze and characterize solar thermal pasteurization; (d) compare technologies on cost-effectiveness and appropriateness; and (e) identify research opportunities. Natural consequences of the study beyond these objectives include a broad knowledge ofmore » water disinfection problems and technologies, introduction of solar thermal pasteurization technologies to a broad audience, and general identification of disinfection opportunities for renewable technologies.« less
Potential of chicken by-products as sources of useful biological resources
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lasekan, Adeseye; Abu Bakar, Fatimah, E-mail: fatim@putra.upm.edu.my; Halal Products Research Institute, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor
By-products from different animal sources are currently being utilised for beneficial purposes. Chicken processing plants all over the world generate large amount of solid by-products in form of heads, legs, bones, viscera and feather. These wastes are often processed into livestock feed, fertilizers and pet foods or totally discarded. Inappropriate disposal of these wastes causes environmental pollution, diseases and loss of useful biological resources like protein, enzymes and lipids. Utilisation methods that make use of these biological components for producing value added products rather than the direct use of the actual waste material might be another viable option for dealingmore » with these wastes. This line of thought has consequently led to researches on these wastes as sources of protein hydrolysates, enzymes and polyunsaturated fatty acids. Due to the multi-applications of protein hydrolysates in various branches of science and industry, and the large body of literature reporting the conversion of animal wastes to hydrolysates, a large section of this review was devoted to this subject. Thus, this review reports the known functional and bioactive properties of hydrolysates derived from chicken by-products as well their utilisation as source of peptone in microbiological media. Methods of producing these hydrolysates including their microbiological safety are discussed. Based on the few references available in the literature, the potential of some chicken by-product as sources of proteases and polyunsaturated fatty acids are pointed out along with some other future applications.« less
Atake, E H
2018-06-20
Togo is experiencing a growing phenomenon of migration and consequently receives remittances from international migrants back to their relatives. Remittances represent about 9.4% of the gross domestic product (GDP), placing Togo in the top 10 recipients of remittances in the world in 2014. Despite the importance of remittances, information on their health outcomes is inadequate, particularly if remittances have a positive impact on the utilisation of maternal and child health services. The aim of this article is to evaluate the impacts of migration on maternal and child health services utilisation. Cross-sectional data analysis of mothers aged 15-49 years who have recently given birth. We used propensity score matching to compare the utilisation of health services by mothers and children from households with migrants to those without migrants. We simulated a potential confounder to assess the robustness of the effects of the estimated treatment (i.e. migration). We also addressed the problem of hidden biases with the bounding approach. Deliveries attended by skilled health personnel were found to be 10.3% higher in migrant households than in households without migrants. The antenatal visits of mothers in migrant households were 3.5%-9.5% higher than those of matched control groups. Compared to the non-migrant households, the migrant households had a positive welfare (postnatal checks at the hospital) impact of 11.9%-12.5% percentage points. Furthermore, through access to health insurance, mothers in migrant families enjoy more financial protection with regard to delivery, prenatal and postnatal care. We also found that children in migrant households benefit from more preventive health inputs such as postnatal checks and vaccinations. Our results suggest that migration contributes greatly to improving births at hospitals, skilled birth assistance, and utilisation of antenatal and postnatal care through the return flow of financial resources. Efforts in health care reforms in Togo should take into account the scope of the positive impacts of migration on the utilisation of maternal and child health services. Copyright © 2018 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Environmental impacts of high penetration renewable energy scenarios for Europe
NASA Astrophysics Data System (ADS)
Berrill, Peter; Arvesen, Anders; Scholz, Yvonne; Gils, Hans Christian; Hertwich, Edgar G.
2016-01-01
The prospect of irreversible environmental alterations and an increasingly volatile climate pressurises societies to reduce greenhouse gas emissions, thereby mitigating climate change impacts. As global electricity demand continues to grow, particularly if considering a future with increased electrification of heat and transport sectors, the imperative to decarbonise our electricity supply becomes more urgent. This letter implements outputs of a detailed power system optimisation model into a prospective life cycle analysis framework in order to present a life cycle analysis of 44 electricity scenarios for Europe in 2050, including analyses of systems based largely on low-carbon fossil energy options (natural gas, and coal with carbon capture and storage (CCS)) as well as systems with high shares of variable renewable energy (VRE) (wind and solar). VRE curtailments and impacts caused by extra energy storage and transmission capabilities necessary in systems based on VRE are taken into account. The results show that systems based largely on VRE perform much better regarding climate change and other impact categories than the investigated systems based on fossil fuels. The climate change impacts from Europe for the year 2050 in a scenario using primarily natural gas are 1400 Tg CO2-eq while in a scenario using mostly coal with CCS the impacts are 480 Tg CO2-eq. Systems based on renewables with an even mix of wind and solar capacity generate impacts of 120-140 Tg CO2-eq. Impacts arising as a result of wind and solar variability do not significantly compromise the climate benefits of utilising these energy resources. VRE systems require more infrastructure leading to much larger mineral resource depletion impacts than fossil fuel systems, and greater land occupation impacts than systems based on natural gas. Emissions and resource requirements from wind power are smaller than from solar power.
Solar Heating and Cooling: An Economic Assessment.
ERIC Educational Resources Information Center
McGarity, Arthur E.
This study serves as an introduction to the important economic considerations that are necessary for an assessment of the potential for solar heating and cooling in the United States. The first chapter introduces the technology that is used to tap solar energy for residential and commercial applications and illustrates the potential significance…
Cooper, Ian R
2016-11-01
Bacteriophages are utilised in the food industry as biocontrol agents to reduce the load of bacteria, and thus reduce potential for human infection. This review focuses on current methods using bacteriophages within the food chain. Limitations of research will be discussed, and the potential for future food-based bacteriophage research. Copyright © 2016 Elsevier B.V. All rights reserved.
Solar energy for process heat: Design/cost studies of four industrial retrofit applications
NASA Technical Reports Server (NTRS)
French, R. L.; Bartera, R. E.
1978-01-01
Five specific California plants with potentially attractive solar applications were identified in a process heat survey. These five plants were visited, process requirements evaluated, and conceptual solar system designs were generated. Four DOE (ERDA) sponsored solar energy system demonstration projects were also reviewed and compared to the design/cost cases included in this report. In four of the five cases investigated, retrofit installations providing significant amounts of thermal energy were found to be feasible. The fifth was rejected because of the condition of the building involved, but the process (soap making) appears to be an attractive potential solar application. Costs, however, tend to be high. Several potential areas for cost reduction were identified including larger collector modules and higher duty cycles.
USDA-ARS?s Scientific Manuscript database
Understanding the spatio-temporal dynamics of insects in agroecosystems is crucial when developing effective management strategies that emphasise biological control of pests. Wild populations of Trichogramma Westwood egg parasitoids are utilised for biological suppression of the potentially resistan...
In vitro bioaccessibility assays are often utilised to determine the potential human exposure to soil contaminants through soil ingestion. Comparative studies have identified inconsistencies in the results obtained with different in vitro assays. In this study we investigated the...
NASA Astrophysics Data System (ADS)
Jin, L.; Borgeson, S.; Fredman, D.; Hans, L.; Spurlock, A.; Todd, A.
2015-12-01
California's renewable portfolio standard (2012) requires the state to get 33% of its electricity from renewable sources by 2020. Increased share of variable renewable sources such as solar and wind in the California electricity system may require more grid flexibility to insure reliable power services. Such grid flexibility can be potentially provided by changes in end use electricity consumptions in response to grid conditions (demand-response). In the solar case, residential consumption in the late afternoon can be used as reserve capacity to balance the drop in solar generation. This study presents our initial attempt to identify, from a behavior perspective, residential demand response potentials in relation to solar ramp events using a data-driven approach. Based on hourly residential energy consumption data, we derive representative daily load shapes focusing on discretionary consumption with an innovative clustering analysis technique. We aggregate the representative load shapes into behavior groups in terms of the timing and rhythm of energy use in the context of solar ramp events. Households of different behavior groups that are active during hours with high solar ramp rates are identified for capturing demand response potential. Insights into the nature and predictability of response to demand-response programs are provided.
Regional comparisons of on-site solar potential in the residential and industrial sectors
NASA Astrophysics Data System (ADS)
Gatzke, A. E.; Skewes-Cox, A. O.
1980-10-01
Regional and subregional differences in the potential development of decentralized solar technologies are studied. Two sectors of the economy were selected for intensive analysis: the residential and industrial sectors. The sequence of analysis follows the same general steps: (1) selection of appropriate prototypes within each land use sector disaggregated by census region; (2) characterization of the end-use energy demand of each prototype in order to match an appropriate decentralized solar technology to the energy demand; (3) assessment of the energy conservation potential within each prototype limited by land use patterns, technology efficiency, and variation in solar insolation; and (4) evaluation of the regional and subregional differences in the land use implications of decentralized energy supply technologies that result from the combination of energy demand, energy supply potential, and the subsequent addition of increasingly more restrictive policies to increase the percent contribution of on-site solar energy.
Islam, M R; Clark, C E F; Garcia, S C; Kerrisk, K L
2015-07-01
The aim of this modelling study was to investigate the effect of large herd size (and land areas) on walking distances and milking interval (MI), and their impact on milk yield and economic penalties when 50% of the total diets were provided from home grown feed either as pasture or grazeable complementary forage rotation (CFR) in an automatic milking system (AMS). Twelve scenarios consisting of 3 AMS herds (400, 600, 800 cows), 2 levels of pasture utilisation (current AMS utilisation of 15.0 t dry matter [DM]/ha, termed as 'moderate'; optimum pasture utilisation of 19.7 t DM/ha, termed as 'high') and 2 rates of incorporation of grazeable complementary forage system (CFS: 0, 30%; CFS = 65% farm is CFR and 35% of farm is pasture) were investigated. Walking distances, energy loss due to walking, MI, reduction in milk yield and income loss were calculated for each treatment based on information available in the literature. With moderate pasture utilisation and 0% CFR, increasing the herd size from 400 to 800 cows resulted in an increase in total walking distances between the parlour and the paddock from 3.5 to 6.3 km. Consequently, MI increased from 15.2 to 16.4 h with increased herd size from 400 to 800 cows. High pasture utilisation (allowing for an increased stocking density) reduced the total walking distances up to 1 km, thus reduced the MI by up to 0.5 h compared to the moderate pasture, 800 cow herd combination. The high pasture utilisation combined with 30% of the farm in CFR in the farm reduced the total walking distances by up to 1.7 km and MI by up to 0.8 h compared to the moderate pasture and 800 cow herd combination. For moderate pasture utilisation, increasing the herd size from 400 to 800 cows resulted in more dramatic milk yield penalty as yield increasing from c.f. 2.6 and 5.1 kg/cow/d respectively, which incurred a loss of up to $AU 1.9/cow/d. Milk yield losses of 0.61 kg and 0.25 kg for every km increase in total walking distance (voluntary return trip from parlour to paddock) and every one hour increase in MI, respectively. The high pasture utilisation combined with 30% of the farm in CFR in the farm increased milk yield by up to 1.5 kg/cow/d, thereby reducing loss by up to $0.5/cow/d (c.f. the moderate pasture and 800 cow herd scenario). Thus, it was concluded that the successful integration of grazeable CFS with pasture has the potential to improve financial performance compared to the pasture only, large herd, AMS.
A learning curve for solar thermal power
NASA Astrophysics Data System (ADS)
Platzer, Werner J.; Dinter, Frank
2016-05-01
Photovoltaics started its success story by predicting the cost degression depending on cumulated installed capacity. This so-called learning curve was published and used for predictions for PV modules first, then predictions of system cost decrease also were developed. This approach is less sensitive to political decisions and changing market situations than predictions on the time axis. Cost degression due to innovation, use of scaling effects, improved project management, standardised procedures including the search for better sites and optimization of project size are learning effects which can only be utilised when projects are developed. Therefore a presentation of CAPEX versus cumulated installed capacity is proposed in order to show the possible future advancement of the technology to politics and market. However from a wide range of publications on cost for CSP it is difficult to derive a learning curve. A logical cost structure for direct and indirect capital expenditure is needed as the basis for further analysis. Using derived reference cost for typical power plant configurations predictions of future cost have been derived. Only on the basis of that cost structure and the learning curve levelised cost of electricity for solar thermal power plants should be calculated for individual projects with different capacity factors in various locations.
Rooftop Energy Potential of Low Income Communities in America REPLICA
Mooney, Meghan (ORCID:0000000309406958); Sigrin, Ben
1970-01-01
The Rooftop Energy Potential of Low Income Communities in America REPLICA data set provides estimates of residential rooftop solar technical potential at the tract-level with emphasis on estimates for Low and Moderate Income LMI populations. In addition to technical potential REPLICA is comprised of 10 additional datasets at the tract-level to provide socio-demographic and market context. The model year vintage of REPLICA is 2015. The LMI solar potential estimates are made at the tract level grouped by Area Median Income AMI income tenure and building type. These estimates are based off of LiDAR data of 128 metropolitan areas statistical modeling and ACS 2011-2015 demographic data. The remaining datasets are supplemental datasets that can be used in conjunction with the technical potential data for general LMI solar analysis planning and policy making. The core dataset is a wide-format CSV file seeds_ii_replica.csv that can be tagged to a tract geometry using the GEOID or GISJOIN fields. In addition users can download geographic shapefiles for the main or supplemental datasets. This dataset was generated as part of the larger NREL-led SEEDSII Solar Energy Evolution and Diffusion Studies project and specifically for the NREL technical report titled Rooftop Solar Technical Potential for Low-to-Moderate Income Households in the United States by Sigrin and Mooney 2018. This dataset is intended to give researchers planners advocates and policy-makers access to credible data to analyze low-income solar issues and potentially perform cost-benefit analysis for program design. To explore the data in an interactive web mapping environment use the NREL SolarForAll app.
Solar Development on Contaminated and Disturbed Lands
DOE Office of Scientific and Technical Information (OSTI.GOV)
Macknick, Jordan; Lee, Courtney; Mosey, Gail
2013-12-01
Land classified as contaminated and disturbed across the United States has the potential to host developments of utility-scale solar power. This report examines the prospect of developing utility- and commercial-scale concentrated solar power (CSP) and solar photovoltaics (PV) technologies on degraded and environmentally contaminated lands. The potential for solar development on contaminated anddisturbed lands was assessed, and for the largest and highest solar resource sites, the economic impacts and feasibility were evaluated. Developing solar power on contaminated and disturbed lands can help create jobs and revitalize local and state economies, and selecting these sites over greenfield sites can potentially havemore » permitting and environmental mitigation advantages. The U.S.Department of Energy (DOE) SunShot goals call for 632 GW of PV and 83 GW of CSP to be deployed by 2050. Conservative land-use estimates of this study (10 acres per megawatt) show that there are disturbed and environmentally contaminated lands throughout the country that could be suitable for utility-scale solar power, and, that there is sufficient land area to meet SunShot solar deployment goals. The purpose of this assessment is to improve the understanding of these sites and facilitate solar developers' selection of contaminated and disturbed sites for development.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gann, Gabriel D. Orebi
Solar neutrinos offer a unique opportunity to study the interaction of neutrinos with matter, a sensitive search for potential new physics effects, and a probe of solar structure and solar system formation. This paper describes the broad physics program addressed by solar neutrino studies, presents the current suite of experiments programs, and describes several potential future detectors that could address the open questions in this field. This paper is a summary of a talk presented at the Neutrino 2014 conference in Boston.
NASA Technical Reports Server (NTRS)
Thiemann, H.; Schunk, R. W.
1990-01-01
The interaction between satellite solar arrays and the LEO plasma is presently studied with particle-in-cell simulations in which an electrical potential was suddenly applied to the solar cell interconnector. The consequent temporal response was followed for the real O(+)-electron mass ratio in the cases of 100- and 250-V solar cells, various solar cell thicknesses, and solar cells with secondary electron emission. Larger applied potentials and thinner solar cells lead to greater initial polarization surface charges, and therefore longer discharging and shielding times. When secondary electron emission from the cover glass is brought to bear, however, the potential structure is nearly planar, allowing constant interaction between plasma electrons and cover glass; a large fraction of the resulting secondary electrons is collected by the interconnector, constituting an order-of-magnitude increase in collected current.
Solar public engagement: the prospective study on FELDA community in Malaysia
NASA Astrophysics Data System (ADS)
Jamiah Tun Jamil, Siti; Azfahani Ahmad, Nur
2017-05-01
Malaysia Energy Outlook 2016 has highlighted that Malaysia's electricity generation mix has always been highly dependent on fossil fuels. There is a concern on energy security for Malaysia recently, since the depletion of fossil fuel occurs and its effect increases the price of electricity tariff. Nevertheless, the energy demand continues to increase, which make the non-fossil renewable energy sources is back on demand. Malaysia's highest potential for renewable energy comes from solar energy and the large roofs of rural houses offer potential to contribute solar electricity for the people. Indeed, the engagement of solar energy to the public is very important in allowing this energy to be accepted by the locals. The paper will review the related literature on public engagement for solar energy project. This paper also tries to prospect the potential of implementing solar electricity for a well-known rural organization in Malaysia, known as FELDA.
Buckley, Belinda; Farnworth, Mark J; Whalley, Gillian
2016-01-08
Regional disparity in both utilisation and the cardiac sonographer workforce has previously been identified. We sought to model the capacity of the cardiac sonographer workforce at a national and District Health Board level to better understand these regional differences. In 2013, surveys were distributed to 18 hospitals who employ cardiac sonographers (return rate 100%). Questions related to cardiac sonographer demographics, echo utilisation and workflow. Actual clinical capacity was calculated from scan duration and annual scan volumes. New Zealand national actual capacity was compared to predicted capacity from three international models. Potential clinical capacity was calculated from the workforce size in fulltime equivalent (FTE) and clinical availability. In New Zealand, scan duration and population-based clinical capacity varies between centres. The New Zealand capacity is similar to the UK 30:70 model, and consistently less than the US model for all scan types. There are marked regional differences in potential versus actual capacity, with 10/16 DHBs demonstrating excess potential capacity. There is regional disparity in the capacity of the cardiac sonographer workforce, which appears to be strongly related to scan duration. Workforce capacity modelling should be used with need and demand modelling to plan adequate levels of service provision.
Gender and the utilisation of health services in the Ashanti Region, Ghana.
Buor, Daniel
2004-09-01
The survey seeks to structure a model for gender-based health services utilisation for the Ashanti Region of Ghana, and in addition, recommend intervention measures to ensure gender equity in the utilisation of health services. A sample size of 650 covered over 3108 houses, and the main research instruments were the questionnaire and formal interview. A multiple regression model is used for the analysis of the relationship between the complex independent variables and utilisation by gender. Results show that although females have a greater need for health services than males, they do not utilise health services as much. Secondly, whereas quality of service, health status, service cost and education have greater effect on male utilisation than females, distance and income have higher impact on female utilisation. It is recommended that, to ensure equity in health care utilisation, females be empowered through increased access to formal education and sustainable income opportunities. The introduction of a national health insurance scheme is also recommended to ensure adequate access by both sexes.
Prospects of Graphene as a Potential Carrier-Transport Material in Third-Generation Solar Cells.
Chowdhury, Towhid H; Islam, Ashraful; Mahmud Hasan, A K; Terdi, M Asri Mat; Arunakumari, M; Prakash Singh, Surya; Alam, Md Khorshed; Bedja, Idriss M; Hafidz Ruslan, Mohd; Sopian, Kamaruzzaman; Amin, Nowshad; Akhtaruzzaman, Md
2016-04-01
Third-generation solar cells are understood to be the pathway to overcoming the issues and drawbacks of the existing solar cell technologies. Since the introduction of graphene in solar cells, it has been providing attractive properties for the next generation of solar cells. Currently, there are more theoretical predictions rather than practical recognitions in third-generation solar cells. Some of the potential of graphene has been explored in organic photovoltaics (OPVs) and dye-sensitized solar cells (DSSCs), but it has yet to be fully comprehended in the recent third-generation inorganic-organic hybrid perovskite solar cells. In this review, the diverse role of graphene in third-generation OPVs and DSSCs will be deliberated to provide an insight on the prospects and challenges of graphene in inorganic-organic hybrid perovskite solar cells. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
NASA Astrophysics Data System (ADS)
Leijtens, J. A. P.
2017-11-01
Fortunately there is almost nothing as reliable as the sun which can consequently be utilized as a very reliable source of spacecraft power. In order to harvest this power, the solar panels have to be pointed towards the sun as accurately and reliably as possible. To this extend, sunsensors are available on almost every satellite to support vital sun-pointing capability throughout the mission, even in the deployment and save mode phases of the satellites life. Given the criticality of the application one would expect that after more than 50 years of sun sensor utilisation, such sensors would be fully matured and optimised. In actual fact though, the majority of sunsensors employed are still coarse sunsensors which have a proven extreme reliability but present major issues regarding albedo sensitivity and pointing accuracy.
DNDO Report: Predicting Solar Modulation Potentials for Modeling Cosmic Background Radiation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Behne, Patrick Alan
The modeling of the detectability of special nuclear material (SNM) at ports and border crossings requires accurate knowledge of the background radiation at those locations. Background radiation originates from two main sources, cosmic and terrestrial. Cosmic background is produced by high-energy galactic cosmic rays (GCR) entering the atmosphere and inducing a cascade of particles that eventually impact the earth’s surface. The solar modulation potential represents one of the primary inputs to modeling cosmic background radiation. Usosokin et al. formally define solar modulation potential as “the mean energy loss [per unit charge] of a cosmic ray particle inside the heliosphere…” Modulationmore » potential, a function of elevation, location, and time, shares an inverse relationship with cosmic background radiation. As a result, radiation detector thresholds require adjustment to account for differing background levels, caused partly by differing solar modulations. Failure to do so can result in higher rates of false positives and failed detection of SNM for low and high levels of solar modulation potential, respectively. This study focuses on solar modulation’s time dependence, and seeks the best method to predict modulation for future dates using Python. To address the task of predicting future solar modulation, we utilize both non-linear least squares sinusoidal curve fitting and cubic spline interpolation. This material will be published in transactions of the ANS winter meeting of November, 2016.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sullivan, Robert G.; Abplanalp, Jennifer M.; Cantwell, Brian L.
In connection with the Bureau of Land Management’s (BLM’s) Solar Programmatic Environmental Impact Statement (Solar PEIS), Argonne National Laboratory (Argonne) has conducted an extended visual impact analysis for selected key observation points (KOPs) within three National Park Service (NPS) units located within the 25-mi (40-km) viewshed of four solar energy zones (SEZs) identified in the Solar PEIS. The analysis includes only those NPS units that the Solar PEIS identified as potentially subject to moderate or strong visual contrasts associated with solar development within the SEZs. The NPS units included in the analysis are Death Valley and Joshua Tree National Parksmore » and El Camino Real De Tierra Adentro National Historic Trail. The analysis showed that certain KOPs in each of these NPS units could potentially be subject to major visual contrast and impacts from solar development within the SEZs, but many of the KOPs would likely be subject to moderate, minor, or negligible contrasts and impacts, generally because they were relatively distant from the relevant SEZ, had views of the SEZ partially blocked by intervening terrain, and/or had very low vertical angles of view toward the SEZ. For all three NPS units, power tower facilities were found to be major contributors to potential visual contrasts, primarily because of the long-distance visibility of intensely bright reflection of light from the receivers on the central towers, but also because of the height and strong vertical line of the tower structures and the potential for night-sky impacts from FAA-mandated hazard navigation lighting.« less
ERIC Educational Resources Information Center
Gao, Fang; Ng, Jacky Chi Kit
2017-01-01
Capital-embedded parental involvement in education is essential in enhancing university enrolment and maximising the educational potentials for equality and excellence. Previous studies in this field have mainly utilised Perna's (2000, 2006) model, which defines parental involvement as social capital and identifies the additive influences of…
Unlocking the Potential of Public Libraries in Supporting Distance Learning
ERIC Educational Resources Information Center
Nabushawo, Harriet Mutambo; Aguti, Jessica Norah; Winterbottom, Mark
2016-01-01
This paper examines the place of public libraries in supporting distance learners in Makerere University, exploring the factors which affect utilisation of their services. The study adopted a survey design with 300 B.Ed. students, collecting data through focus group discussions, structured questionnaires and individual interviews.
Investigating Factors Affecting the Uptake of Automated Assessment Technology
ERIC Educational Resources Information Center
Dreher, Carl; Reiners, Torsten; Dreher, Heinz
2011-01-01
Automated assessment is an emerging innovation in educational praxis, however its pedagogical potential is not fully utilised in Australia, particularly regarding automated essay grading. The rationale for this research is that the usage of automated assessment currently lags behind the capacity that the technology provides, thus restricting the…
ERIC Educational Resources Information Center
Agbenyega, Joseph S.; Tamakloe, Deborah E.; Klibthong, Sunanta
2017-01-01
This research utilised a "stimulated recall" methodology [Calderhead, J. 1981. "Stimulated Recall: A Method for Research on Teaching." "British Journal of Educational Psychology" 51: 211-217] to explore the potential of African folklore, specifically Ghanaian folk stories in the development of children's reflective…
How Graphic Novels Support Reading Comprehension Strategy Development in Children
ERIC Educational Resources Information Center
Brenna, Beverley
2013-01-01
This qualitative case study explored the relationship between comprehension strategies and graphic novels in one Grade 4 classroom, utilising children as informants. The primary research questions related to children's applications of metacognitive reading comprehension strategies as well as the potential for graphic novels to support the…
Glencross, Brett D; Blyth, David; Bourne, Nicholas; Cheers, Susan; Irvin, Simon; Wade, Nicholas M
2017-02-01
This study examined the effect of including different dietary proportions of starch, protein and lipid, in diets balanced for digestible energy, on the utilisation efficiencies of dietary energy by barramundi (Lates calcarifer). Each diet was fed at one of three ration levels (satiety, 80 % of initial satiety and 60 % of initial satiety) for a 42-d period. Fish performance measures (weight gain, feed intake and feed conversion ratio) were all affected by dietary energy source. The efficiency of energy utilisation was significantly reduced in fish fed the starch diet relative to the other diets, but there were no significant effects between the other macronutrients. This reduction in efficiency of utilisation was derived from a multifactorial change in both protein and lipid utilisation. The rate of protein utilisation deteriorated as the amount of starch included in the diet increased. Lipid utilisation was most dramatically affected by inclusion levels of lipid in the diet, with diets low in lipid producing component lipid utilisation rates well above 1·3, which indicates substantial lipid synthesis from other energy sources. However, the energetic cost of lipid gain was as low as 0·65 kJ per kJ of lipid deposited, indicating that barramundi very efficiently store energy in the form of lipid, particularly from dietary starch energy. This study defines how the utilisation efficiency of dietary digestible energy by barramundi is influenced by the macronutrient source providing that energy, and that the inclusion of starch causes problems with protein utilisation in this species.
Analysis of future generation solar cells and materials
NASA Astrophysics Data System (ADS)
Yamaguchi, Masafumi; Zhu, Lin; Akiyama, Hidefumi; Kanemitsu, Yoshihiko; Tampo, Hitoshi; Shibata, Hajime; Lee, Kan-Hua; Araki, Kenji; Kojima, Nobuaki
2018-04-01
The efficiency potentials of future generation solar cells such as wide bandgap chalcopyrite, Cu2ZnSnS4 (CZTS), Cu2ZnSn(S,Se)4 (CZTSSe), multi quantum well (MQW) and quantum dot (QD) solar cells are discussed on the basis of external radiative efficiency (ERE), open-circuit voltage loss, fill factor loss, and nonradiative recombination losses. CZTS and CZTSSe solar cells have efficiency potentials of more than 20% owing to the improvement in ERE from about 0.001 to 1%. MQW and QD cells have efficiency potentials of 24.8%, and 25.8% owing to the improvement in ERE from around 0.01 to 0.1%, and 1%, respectively. In this paper, the effects of nonradiative recombination on the properties of future generation solar cells are discussed.
Solar Energy: Potential Powerhouse for Jobs
ERIC Educational Resources Information Center
McCallion, Tom
1976-01-01
Components of solar energy systems are described, the development of the solar industry discussed, and implications are drawn for employment opportunities in industries (which may expand into new, solar-related areas) and in the professions, from law to sales, upon the advent of solar heating. (AJ)
Overview of Opportunities for Co-Location of Solar Energy Technologies and Vegetation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Macknick, Jordan; Beatty, Brenda; Hill, Graham
2013-12-01
Large-scale solar facilities have the potential to contribute significantly to national electricity production. Many solar installations are large-scale or utility-scale, with a capacity over 1 MW and connected directly to the electric grid. Large-scale solar facilities offer an opportunity to achieve economies of scale in solar deployment, yet there have been concerns about the amount of land required for solar projects and the impact of solar projects on local habitat. During the site preparation phase for utility-scale solar facilities, developers often grade land and remove all vegetation to minimize installation and operational costs, prevent plants from shading panels, and minimizemore » potential fire or wildlife risks. However, the common site preparation practice of removing vegetation can be avoided in certain circumstances, and there have been successful examples where solar facilities have been co-located with agricultural operations or have native vegetation growing beneath the panels. In this study we outline some of the impacts that large-scale solar facilities can have on the local environment, provide examples of installations where impacts have been minimized through co-location with vegetation, characterize the types of co-location, and give an overview of the potential benefits from co-location of solar energy projects and vegetation. The varieties of co-location can be replicated or modified for site-specific use at other solar energy installations around the world. We conclude with opportunities to improve upon our understanding of ways to reduce the environmental impacts of large-scale solar installations.« less
Gotsadze, George; Tang, Wenze; Shengelia, Natia; Zoidze, Akaki
2017-05-02
The healthcare financing reforms initiated by the Government of Georgia in 2007 have positively affected inpatient service utilisation and enhanced financial protection, especially for the poor, but they have failed to facilitate outpatient service use among chronic patients. Non-communicable diseases significantly affect Georgia's ageing population. Consequently, in this paper, we look at the evidence emerging from determinants analysis of outpatient service utilisation and if the finding can help identify possible policy choices in Georgia, especially regarding benefit package design for individuals with chronic conditions. We used Andersen's behavioural model of health service utilisation to identify the critical determinants that affect outpatient service use. A multinomial logistic regression was carried out with complex survey design using the data from two nationally representative cross-sectional population-based health utilisation and expenditure surveys conducted in Georgia in 2007 and 2010, which allowed us to assess the relationship between the determinants and outpatient service use. The study revealed the determinants that significantly impede outpatient service use. Low income, 45- to 64-year-old Georgian males with low educational attainment and suffering from a chronic health problem have the lowest odds for service use compared to the rest of the population. Using Andersen's behavioural model and assessing the determinants of outpatient service use has the potential to inform possible policy responses, especially those driving services use among chronic patients. The possible policy responses include reducing financial access barriers with the help of public subsidies for sub-groups of the population with the lowest access to care; focusing/expanding state-funded benefits for the most prevalent chronic conditions, which are responsible for the greatest disease burden; or supporting chronic disease management programs for the most prevalent chronic diseases and for special age groups aimed at the timely detection, education and management of chronic patients.
Efficient use of land to meet sustainable energy needs
NASA Astrophysics Data System (ADS)
Hernandez, Rebecca R.; Hoffacker, Madison K.; Field, Christopher B.
2015-04-01
The deployment of renewable energy systems, such as solar energy, to achieve universal access to electricity, heat and transportation, and to mitigate climate change is arguably the most exigent challenge facing humans today. However, the goal of rapidly developing solar energy systems is complicated by land and environmental constraints, increasing uncertainty about the future of the global energy landscape. Here, we test the hypothesis that land, energy and environmental compatibility can be achieved with small- and utility-scale solar energy within existing developed areas in the state of California (USA), a global solar energy hotspot. We found that the quantity of accessible energy potentially produced from photovoltaic (PV) and concentrating solar power (CSP) within the built environment (`compatible’) exceeds current statewide demand. We identify additional sites beyond the built environment (`potentially compatible’) that further augment this potential. Areas for small- and utility-scale solar energy development within the built environment comprise 11,000-15,000 and 6,000 TWh yr-1 of PV and CSP generation-based potential, respectively, and could meet the state of California’s energy consumptive demand three to five times over. Solar energy within the built environment may be an overlooked opportunity for meeting sustainable energy needs in places with land and environmental constraints.
Market development directory for solar industrial process heat systems
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
The purpose of this directory is to provide a basis for market development activities through a location listing of key trade associations, trade periodicals, and key firms for three target groups. Potential industrial users and potential IPH system designers were identified as the prime targets for market development activities. The bulk of the directory is a listing of these two groups. The third group, solar IPH equipment manufacturers, was included to provide an information source for potential industrial users and potential IPH system designers. Trade associates and their publications are listed for selected four-digit Standard Industrial Code (SIC) industries. Sincemore » industries requiring relatively lower temperature process heat probably will comprise most of the near-term market for solar IPH systems, the 80 SIC's included in this chapter have process temperature requirements less than 350/sup 0/F. Some key statistics and a location list of the largest plants (according to number of employees) in each state are included for 15 of the 80 SIC's. Architectural/engineering and consulting firms are listed which are known to have solar experience. Professional associated and periodicals to which information on solar IPH sytstems may be directed also are included. Solar equipment manufacturers and their associations are listed. The listing is based on the SERI Solar Energy Information Data Base (SEIDB).« less
The Job Creation Potential of Solar and Conservation: A Critical Evaluation.
ERIC Educational Resources Information Center
Schachter, Mary
Solar proponents claim that a solar- and conservation-oriented economy will create vastly larger numbers of jobs than the conventional and nuclear alternatives. Comparing energy alternatives in terms of job creation potential is tenuous at best due to the paucity of analysis in this area. Ideally, both the quantitative and qualitative aspects of…
Solar and Net Radiation for Estimating Potential Evaporation from Three Vegetation Canopies
D.M. Amatya; R.W. Skaggs; G.W. Cheschier; G.P. Fernandez
2000-01-01
Solar and net radiation data are frequent/y used in estimating potential evaporation (PE) from various vegetative surfaces needed for water balance and hydrologic modeling studies. Weather parameters such as air temperature, relative humidity, wind speed, solar radiation, and net radiation have been continuously monitored using automated sensors to estimate PE for...
Analysis of Surface Charging for a Candidate Solar Sail Mission Using NASCAP-2K
NASA Technical Reports Server (NTRS)
Parker, Linda Neergaard; Minow, Joseph L.; Davis, V. A.; Mandell, Myron; Gardner, Barbara
2005-01-01
The characterization of the electromagnetic interaction for a solar sail in the solar wind environment and identification of viable charging mitigation strategies are critical solar sail mission design tasks. Spacecraft charging has important implications both for science applications and for lifetime and reliability issues of sail propulsion systems. To that end, surface charging calculations of a candidate 150-meter-class solar sail spacecraft for the 0.5 AU solar polar and 1.9 AU LI solar wind environments are performed. A model of the spacecraft with candidate materials having appropriate electrical properties is constructed using Object Toolkit. The spacecraft charging analysis is performed using Nascap-2k. the NASA/AFRL sponsored spacecraft charging analysis tool. Nominal and atypical solar wind environments appropriate for the 0.5 AU and 1.0 AU missions are used to establish current collection of solar wind ions and electrons. Finally, a geostationary orbit environment case is included to demonstrate a bounding example of extreme (negative) charging of a solar sail spacecraft. Results from the charging analyses demonstrate that minimal differential potentials (and resulting threat of electrostatic discharge) occur when the spacecraft is constructed entirely of conducting materials, as anticipated from standard guidelines for mitigation of spacecraft charging issues. Examples with dielectric materials exposed to the space environment exhibit differential potentials ranging from a few volts to extreme potentials in the kilovolt range.
Analysis of Surface Charging for a Candidate Solar Sail Mission Using Nascap-2k
NASA Technical Reports Server (NTRS)
Parker, Linda Neergaard; Minow, Joseph I.; Davis, Victoria; Mandell, Myron; Gardner, Barbara
2005-01-01
The characterization of the electromagnetic interaction for a solar sail in the solar wind environment and identification of viable charging mitigation strategies are critical solar sail mission design task. Spacecraft charging has important implications both for science applications and for lifetime and reliability issues of sail propulsion systems. To that end, surface charging calculations of a candidate 150-meter-class solar sail spacecraft for the 0.5 AU solar polar and 1.0 AU L1 solar wind environments are performed. A model of the spacecraft with candidate materials having appropriate electrical properties is constructed using Object Toolkit. The spacecraft charging analysis is performed using Nascap-2k, the NASA/AFRL sponsored spacecraft charging analysis tool. Nominal and atypical solar wind environments appropriate for the 0.5 AU and 1.0 AU missions are used to establish current collection of solar wind ions and electrons. Finally, a geostationary orbit environment case is included to demonstrate a bounding example of extreme (negative) charging of a solar sail spacecraft. Results from the charging analyses demonstrate that minimal differential potentials (and resulting threat of electrostatic discharge) occur when the spacecraft is constructed entirely of conducting materials, as anticipated from standard guidelines for mitigation of spacecraft charging issues. Examples with dielectric materials exposed to the space environment exhibit differential potentials ranging from a few volts to extreme potentials in the kilovolt range.
A marketing strategy for a nursing college.
Pryde, M; Muller, M
1995-08-01
The objective of this study is to explore and describe a marketing strategy for a nursing college. An explorative and descriptive research design, within the context of a nursing college and affiliated hospitals, was followed. A literature study of marketing models was undertaken and the Delphi-method was utilised to determine the contribution of marketing staff and the possible content of a marketing strategy for a nursing college. The results were utilised to describe guidelines for such a strategy, consisting of marketers/marketing agents, target market, product, price, promotional activities, place and market research. Recommendations include the planning, implementation and evaluation of strategy, inservice training for potential marketing agents, inclusion of marketing as part of the formal education of tutors and nurse managers, as well as an impact study of the scholar as the main consumer.
Thin film, concentrator, and multijunction space solar cells: Status and potential
NASA Technical Reports Server (NTRS)
Flood, Dennis J.
1991-01-01
Recent, rapid advances in a variety of solar cell technologies offer the potential for significantly enhancing, or enabling entirely new, mission capabilities. Thin film solar cells are of particular interest. A review is provided of the status of those thin film cell technologies of interest for space applications, and the issues to be resolved before mission planners can consider them. A short summary of recent developments in concentrator and multijunction space solar cell and array technology is given.
Thin film, concentrator and multijunction space solar cells: Status and potential
NASA Technical Reports Server (NTRS)
Flood, Dennis J.
1991-01-01
Recent, rapid advances in a variety of solar cell technologies offer the potential for significantly enhancing, or enabling entirely new, mission capabilities. Thin film solar cells are of particular interest in that regard. A review is provided of the status of those thin film cell technologies of interest for space applications, and the issues to be resolved before mission planners can consider them. A short summary is also given of recent developments in concentrator and multijunction space solar cell and array technology.
Utilisation of cancer screening services by disabled women in Chile
Rotarou, Elena S.
2017-01-01
Background Research has shown that women with disabilities face additional challenges in accessing and using healthcare services compared to non-disabled women. However, relatively little is known about the utilisation of cancer screening services for women with disabilities. This study addresses this gap by examining the utilisation of the Papanicolaou test and mammography for disabled women in Chile. Methods We used cross-sectional data, taken from a 2015 nationally-representative survey. Initially, we employed logistic regressions to test for differences in utilisation rates for the Papanicolaou test (66,281 observations) and the mammogram (35,294 observations) between disabled and non-disabled women. Next, logistic regressions were used to investigate the demographic, socioeconomic, and health-related factors affecting utilisation rates for cancer screening services for disabled women (sample sizes: 5,823 observations for the Papanicolaou test and 5,731 observations for the mammogram). Results Disabled women were less likely to undergo screening tests than non-disabled women. For the Papanicolaou test and mammography, the multivariable regression models showed that living in rural areas, having higher education, being affiliated with a private health insurance company, giving a good health self-assessment score, and being under medical treatment for other illnesses were associated with higher utilisation rates. On the other hand, being single, inactive with regard to employment, and having a better income were linked with lower utilisation. While utilisation rates for both disabled and non-disabled women have increased since 2006, the utilisation disparity has slightly increased. Conclusions This study shows the influence of various factors in the utilisation rates of preventive cancer screening services for disabled women. To develop effective initiatives targeting inequalities in the utilisation of cancer screening tests, it is important to move beyond an exclusively single-disease approach and acknowledge the complexity of the patient population. PMID:28459874
Utilisation of cancer screening services by disabled women in Chile.
Sakellariou, Dikaios; Rotarou, Elena S
2017-01-01
Research has shown that women with disabilities face additional challenges in accessing and using healthcare services compared to non-disabled women. However, relatively little is known about the utilisation of cancer screening services for women with disabilities. This study addresses this gap by examining the utilisation of the Papanicolaou test and mammography for disabled women in Chile. We used cross-sectional data, taken from a 2015 nationally-representative survey. Initially, we employed logistic regressions to test for differences in utilisation rates for the Papanicolaou test (66,281 observations) and the mammogram (35,294 observations) between disabled and non-disabled women. Next, logistic regressions were used to investigate the demographic, socioeconomic, and health-related factors affecting utilisation rates for cancer screening services for disabled women (sample sizes: 5,823 observations for the Papanicolaou test and 5,731 observations for the mammogram). Disabled women were less likely to undergo screening tests than non-disabled women. For the Papanicolaou test and mammography, the multivariable regression models showed that living in rural areas, having higher education, being affiliated with a private health insurance company, giving a good health self-assessment score, and being under medical treatment for other illnesses were associated with higher utilisation rates. On the other hand, being single, inactive with regard to employment, and having a better income were linked with lower utilisation. While utilisation rates for both disabled and non-disabled women have increased since 2006, the utilisation disparity has slightly increased. This study shows the influence of various factors in the utilisation rates of preventive cancer screening services for disabled women. To develop effective initiatives targeting inequalities in the utilisation of cancer screening tests, it is important to move beyond an exclusively single-disease approach and acknowledge the complexity of the patient population.
Trends, determinants and inequities of 4+ ANC utilisation in Bangladesh.
Rahman, Aminur; Nisha, Monjura Khatun; Begum, Tahmina; Ahmed, Sayem; Alam, Nurul; Anwar, Iqbal
2017-01-13
The objectives of this study are to document the trend on utilisation of four or more (4 + ) antenatal care (ANC) over the last 22 years period and to explore the determinants and inequity of 4 + ANC utilisation as reported by the last two Bangladesh Demographic and Health surveys (BDHS) (2011 and 2014). The data related to ANC have been extracted from the BDHS data set which is available online as an open source. STATA 13 software was used for organising and analysing the data. The outcome variable considered for this study was utilisation of 4 + ANC. Trends of 4 + ANC were measured in percentage and predictors for 4 + ANC were measured through bivariate and multivariable analysis. The concentration index was estimated for assessing inequity in 4 + ANC utilisation. Utilisation of 4 + ANC has increased by about 26% between the year 1994 and 2014. Higher level of education, residing in urban region and richest wealth quintile were found to be significant predictors. The utilisation of 4 + ANC has decreased with increasing parity and maternal age. The inequity indices showed consistent inequities in 4 + ANC utilisation, and such inequities were increased between 2011 and 2014. In Bangladesh, the utilisation of any ANC rose steadily between 1994 and 2014, but progress in terms of 4 + ANC utilisation was much slower as the expectation was to achieve the national set target (50%: 4 + ANC utilisation) by 2016. Socio-economic inequities were observed in groups that failed to attend a 4 + ANC visit. Policymakers should pay special attention to increase the 4 + ANC coverage where this study can facilitate to identify the target groups whom need to be intervened on priority basis.
Solar variability: Implications for global change
NASA Technical Reports Server (NTRS)
Lean, Judith; Rind, David
1994-01-01
Solar variability is examined in search of implications for global change. The topics covered include the following: solar variation modification of global surface temperature; the significance of solar variability with respect to future climate change; and methods of reducing the uncertainty of the potential amplitude of solar variability on longer time scales.
Rooftop solar photovoltaic potential in cities: how scalable are assessment approaches?
NASA Astrophysics Data System (ADS)
Castellanos, Sergio; Sunter, Deborah A.; Kammen, Daniel M.
2017-12-01
Distributed photovoltaics (PV) have played a critical role in the deployment of solar energy, currently making up roughly half of the global PV installed capacity. However, there remains significant unused economically beneficial potential. Estimates of the total technical potential for rooftop PV systems in the United States calculate a generation comparable to approximately 40% of the 2016 total national electric-sector sales. To best take advantage of the rooftop PV potential, effective analytic tools that support deployment strategies and aggressive local, state, and national policies to reduce the soft cost of solar energy are vital. A key step is the low-cost automation of data analysis and business case presentation for structure-integrated solar energy. In this paper, the scalability and resolution of various methods to assess the urban rooftop PV potential are compared, concluding with suggestions for future work in bridging methodologies to better assist policy makers.
Estimates of Sputter Yields of Solar-Wind Heavy Ions of Lunar Regolith Materials
NASA Technical Reports Server (NTRS)
Barghouty, Abdulmasser F.; Adams, James H., Jr.
2008-01-01
At energies of approximately 1 keV/amu, solar-wind protons and heavy ions interact with the lunar surface materials via a number of microscopic interactions that include sputtering. Solar-wind induced sputtering is a main mechanism by which the composition of the topmost layers of the lunar surface can change, dynamically and preferentially. This work concentrates on sputtering induced by solar-wind heavy ions. Sputtering associated with slow (speeds the electrons speed in its first Bohr orbit) and highly charged ions are known to include both kinetic and potential sputtering. Potential sputtering enjoys some unique characteristics that makes it of special interest to lunar science and exploration. Unlike the yield from kinetic sputtering where simulation and approximation schemes exist, the yield from potential sputtering is not as easy to estimate. This work will present a preliminary numerical scheme designed to estimate potential sputtering yields from reactions relevant to this aspect of solar-wind lunar-surface coupling.
Parabolic solar cooker: Cooking with heat pipe vs direct spiral copper tubes
NASA Astrophysics Data System (ADS)
Craig, Omotoyosi O.; Dobson, Robert T.
2016-05-01
Cooking with solar energy has been seen by many researchers as a solution to the challenges of poverty and hunger in the world. This is no exception in Africa, as solar coking is viewed as an avenue to eliminate the problem of food insecurity, insufficient energy supply for household and industrial cooking. There are several types of solar cookers that have been manufactured and highlighted in literature. The parabolic types of solar cookers are known to reach higher temperatures and therefore cook faster. These cookers are currently being developed for indoor cooking. This technology has however suffered low cooking efficiency and thus leads to underutilization of the high heat energy captured from the sun in the cooking. This has made parabolic solar cookers unable to compete with other conventional types of cookers. Several methods to maximize heat from the sun for indirect cooking has been developed, and the need to improve on them of utmost urgency. This paper investigates how to optimize the heat collected from the concentrating types of cookers by proposing and comparing two types of cooking sections: the spiral hot plate copper tube and the heat pipe plate. The system uses the concentrating solar parabolic dish technology to focus the sun on a conical cavity of copper tubes and the heat is stored inside an insulated tank which acts both as storage and cooking plate. The use of heat pipes to transfer heat between the oil storage and the cooking pot was compared to the use of a direct natural syphon principle which is achieved using copper tubes in spiral form like electric stove. An accurate theoretical analysis for the heat pipe cooker was achieved by solving the boiling and vaporization in the evaporator side and then balancing it with the condensation and liquid-vapour interaction in the condenser part while correct heat transfer, pressure and height balancing was calculated in the second experiment. The results show and compare the cooking time, boiling characteristics, overall utilisation efficiencies and necessary comparison between the two system and other existing systems. AIP Proceedings article template has many predefined paragraph styles for you to use/apply as you write your paper. To format your abstract, use the Microsoft Word template style.
Potential of Solar Energy in Kota Kinabalu, Sabah: An Estimate Using a Photovoltaic System Model
NASA Astrophysics Data System (ADS)
Markos, F. M.; Sentian, J.
2016-04-01
Solar energy is becoming popular as an alternative renewable energy to conventional energy source, particularly in the tropics, where duration and intensity of solar radiation are longer. This study is to assess the potential of solar energy generated from solar for Kota Kinabalu, a rapidly developing city in the State of Sabah, Malaysia. A year data of solar radiation was obtained using pyranometer, which was located at Universiti Malaysia Sabah (6.0367° N, 116.1186° E). It was concluded that the annual average solar radiation received in Kota Kinabalu was 182 W/m2. In estimating the potential energy generated from solar for Kota Kinabalu city area, a photovoltaic (PV) system model was used. The results showed that, Kota Kinabalu is estimated to produce 29,794 kWh/m2 of electricity from the solar radiation received in a year. This is equivalent to 0.014 MW of electricity produced just by using one solar panel. Considering the power demand in Sabah by 2020 is 1,331 MW, this model showed that the solar energy can contribute around 4% of energy for power demand, with 1 MW capacity of the PV system. 1 MW of PV system installation will require about 0.0328% from total area of the city. This assessment could suggest that, exploration for solar power energy as an alternative source of renewable energy in the city can be optimised and designed to attain significant higher percentage of contribution to the energy demand in the state.
NASA Astrophysics Data System (ADS)
Suhartini, S.; Heaven, S.; Banks, C. J.
2018-03-01
Anaerobic digestion (AD), known as a biological process without oxygen to convert complex organic materials into biogas, is capable of processing large tonnage quantities of biomass, such as sugar beet pulp (SBP). In addition to biogas production, its use allows nutrients and organic carbon recycle back to agriculture through the spreading of digestate. Digestate still contains high amount of nutrients (N, P, K) for use as biofertiliser. The aims of this research were to determine biogas/methane potential as a baseline for comparison with performance in semi-continuous digestion, and to determine nutrient and potentially toxic elements (PTE) of digestate fractions with respect to their potential for utilisation in agriculture. The Biochemical Methane Potential (BMP) test was performed in triplicate against blank and positive controls over a period of 28 days with gas measured at regular intervals. Semi-continuous AD of SBP was operated under mesophilic and thermophilic condition for 206 and 165 days. The results indicated that SBP is a very promising feedstock for AD, with the average BMP of 0.321 l CH4 g-1 VS and biogas potential of 0.605 l g-1 VS. Under semi-continuous operation, SBP also demonstrated positive results. Digestates from mesophilic and thermophilic AD of SBP contained useful quantities of N, P and K, with an acceptable Ni concentration in accordance to limits for PTE. These results suggest that digestate has the potential to be utilised on agricultural and arable land. This study illustrated the positive effects of applying AD to the achievement of economic savings and environmental-friendly performance.
Higher order statistical moment application for solar PV potential analysis
NASA Astrophysics Data System (ADS)
Basri, Mohd Juhari Mat; Abdullah, Samizee; Azrulhisham, Engku Ahmad; Harun, Khairulezuan
2016-10-01
Solar photovoltaic energy could be as alternative energy to fossil fuel, which is depleting and posing a global warming problem. However, this renewable energy is so variable and intermittent to be relied on. Therefore the knowledge of energy potential is very important for any site to build this solar photovoltaic power generation system. Here, the application of higher order statistical moment model is being analyzed using data collected from 5MW grid-connected photovoltaic system. Due to the dynamic changes of skewness and kurtosis of AC power and solar irradiance distributions of the solar farm, Pearson system where the probability distribution is calculated by matching their theoretical moments with that of the empirical moments of a distribution could be suitable for this purpose. On the advantage of the Pearson system in MATLAB, a software programming has been developed to help in data processing for distribution fitting and potential analysis for future projection of amount of AC power and solar irradiance availability.
Ares V: Application to Solar System Scientific Exploration
NASA Technical Reports Server (NTRS)
Reh, Kim; Spilker, Tom; Elliott, John; Balint, Tibor; Donahue, Ben; McCormick, Dave; Smith, David B.; Tandon, Sunil; Woodcock, Gordon
2008-01-01
The following sections describe Ares V performance and its payoff to a wide array of potential solar system exploration missions. Application to potential Astrophysics missions is addressed in Reference 3.
Ries, Laure Nicolas Annick; de Assis, Leandro José; Rodrigues, Fernando José Santos; Caldana, Camila; Rocha, Marina Campos; Malavazi, Iran; Bayram, Özgür; Goldman, Gustavo H
2018-05-24
The pyruvate dehydrogenase complex (PDH), that converts pyruvate to acetyl-coA, is regulated by pyruvate dehydrogenase kinases (PDHK) and phosphatases (PDHP) that have been shown to be important for morphology, pathogenicity and carbon source utilisation in different fungal species. The aim of this study was to investigate the role played by the three PDHKs PkpA, PkpB and PkpC in carbon source utilisation in the reference filamentous fungus Aspergillus nidulans , in order to unravel regulatory mechanisms which could prove useful for fungal biotechnological and biomedical applications. PkpA and PkpB were shown to be mitochondrial whereas PkpC localised to the mitochondria in a carbon source-dependent manner. Only PkpA was shown to regulate PDH activity. In the presence of glucose, deletion of pkpA and pkpC resulted in reduced glucose utilisation, which affected carbon catabolite repression (CCR) and hydrolytic enzyme secretion, due to de-regulated glycolysis and TCA cycle enzyme activities. Furthermore, PkpC was shown to be required for the correct metabolic utilisation of cellulose and acetate. PkpC negatively regulated the activity of the glyoxylate cycle enzyme isocitrate lyase (ICL), required for acetate metabolism. In summary, this study identified PDHKs important for the regulation of central carbon metabolism in the presence of different carbon sources, with effects on the secretion of biotechnologically important enzymes and carbon source-related growth. This work demonstrates how central carbon metabolism can affect a variety of fungal traits and lays a basis for further investigation into these characteristics with potential interest for different applications. Copyright © 2018, G3: Genes, Genomes, Genetics.
Apelin targets gut contraction to control glucose metabolism via the brain
Fournel, Audren; Drougard, Anne; Duparc, Thibaut; Marlin, Alysson; Brierley, Stuart M; Castro, Joel; Le-Gonidec, Sophie; Masri, Bernard; Colom, André; Lucas, Alexandre; Rousset, Perrine; Cenac, Nicolas; Vergnolle, Nathalie; Valet, Philippe; Cani, Patrice D; Knauf, Claude
2017-01-01
Objective The gut–brain axis is considered as a major regulatory checkpoint in the control of glucose homeostasis. The detection of nutrients and/or hormones in the duodenum informs the hypothalamus of the host's nutritional state. This process may occur via hypothalamic neurons modulating central release of nitric oxide (NO), which in turn controls glucose entry into tissues. The enteric nervous system (ENS) modulates intestinal contractions in response to various stimuli, but the importance of this interaction in the control of glucose homeostasis via the brain is unknown. We studied whether apelin, a bioactive peptide present in the gut, regulates ENS-evoked contractions, thereby identifying a new physiological partner in the control of glucose utilisation via the hypothalamus. Design We measured the effect of apelin on electrical and mechanical duodenal responses via telemetry probes and isotonic sensors in normal and obese/diabetic mice. Changes in hypothalamic NO release, in response to duodenal contraction modulated by apelin, were evaluated in real time with specific amperometric probes. Glucose utilisation in tissues was measured with orally administrated radiolabeled glucose. Results In normal and obese/diabetic mice, glucose utilisation is improved by the decrease of ENS/contraction activities in response to apelin, which generates an increase in hypothalamic NO release. As a consequence, glucose entry is significantly increased in the muscle. Conclusions Here, we identify a novel mode of communication between the intestine and the hypothalamus that controls glucose utilisation. Moreover, our data identified oral apelin administration as a novel potential target to treat metabolic disorders. PMID:26565000
Solar thermal power plants in small utilities - An economic impact analysis
NASA Technical Reports Server (NTRS)
Bluhm, S. A.; Ferber, R. R.; Mayo, L. G.
1979-01-01
A study was performed to assess the potential economic impact of small solar thermal electric power systems in statistically representative synthetic small utilities of the Southwestern United States. Power supply expansion plans were compared on the basis of present worth of future revenue requirements for 1980-2000 with and without solar thermal plants. Coal-fired and oil-fired municipal utility expansion plans with 5 percent solar penetration were 0.5 percent and 2.25 percent less expensive, respectively, than the corresponding conventional plan. At $969/kWe, which assumes the same low cost solar equipment but no improvement in site development costs, solar penetration of 5 percent in the oil-fired municipal reduced revenue requirements 0.88 percent. The paper concludes that some solar thermal plants are potentially economic in small community utilities of the Southwest.
Solar and Heliospheric Data Requirements: Going Further Than L1
NASA Technical Reports Server (NTRS)
Szabo, A.
2011-01-01
Current operational space weather forecasting relies on solar wind observations made by the ACE spacecraft located at the L1 point providing 30-40 minutes warning time. Some use is also made of SOHO and STEREO solar imaging that potentially can give multiple days of warning time. However, our understanding of the propagation and evolution of solar wind transients is still limited resulting in a typical timing uncertainty of approximately 10 hours. In order to improve this critical understanding, a number of NASA missions are being planned. Specifically the Solar Probe Plus and Solar Orbiter missions will investigate the inner Heliospheric evolution of coronal mass ejections and the acceleration and propagation of solar energetic particles. In addition, a number of multi-spacecraft concepts have been studied that have the potential to significantly improve the accuracy of long-term space weather forecasts.
NASA Astrophysics Data System (ADS)
Adeleke, A. K.; Smit, J. L.
2016-06-01
Apart from the drive to reduce carbon dioxide emissions by carbon-intensive economies like South Africa, the recent spate of electricity load shedding across most part of the country, including Cape Town has left electricity consumers scampering for alternatives, so as to rely less on the national grid. Solar energy, which is adequately available in most part of Africa and regarded as a clean and renewable source of energy, makes it possible to generate electricity by using photovoltaics technology. However, before time and financial resources are invested into rooftop solar photovoltaic systems in urban areas, it is important to evaluate the potential of the building rooftop, intended to be used in harvesting the solar energy. This paper presents methodologies making use of LiDAR data and other ancillary data, such as high-resolution aerial imagery, to automatically extract building rooftops in City of Cape Town and evaluate their potentials for solar photovoltaics systems. Two main processes were involved: (1) automatic extraction of building roofs using the integration of LiDAR data and aerial imagery in order to derive its' outline and areal coverage; and (2) estimating the global solar radiation incidence on each roof surface using an elevation model derived from the LiDAR data, in order to evaluate its solar photovoltaic potential. This resulted in a geodatabase, which can be queried to retrieve salient information about the viability of a particular building roof for solar photovoltaic installation.
USDA-ARS?s Scientific Manuscript database
Early stage infections caused by fungal/oomycete spores can remain undetected until signs or symptoms develop. Serological and molecular techniques are currently used for detecting these pathogens. Next-generation sequencing (NGS) has potential as a diagnostic tool, due to the capacity to target mul...
A Call to Embrace Social Reading in Higher Education
ERIC Educational Resources Information Center
Dean, Matthew D.
2016-01-01
Social reading can broadly be described as the experience surrounding the reading of electronic books, more commonly known as eBooks. Utilising eTextbooks and social reading at a university offers some powerful potential to engage students and help them succeed in their studies. A broad overview of the current landscape and recent initiatives…
Exploring Sex Differences in Autistic Traits: A Factor Analytic Study of Adults with Autism
ERIC Educational Resources Information Center
Grove, Rachel; Hoekstra, Rosa A.; Wierda, Marlies; Begeer, Sander
2017-01-01
Research has highlighted potential differences in the phenotypic and clinical presentation of autism spectrum conditions across sex. Furthermore, the measures utilised to evaluate autism spectrum conditions may be biased towards the male autism phenotype. It is important to determine whether these instruments measure the autism phenotype…
13_2_30: Experiences, Perceptions and Expectations of Retail Employment for Generation Y
ERIC Educational Resources Information Center
Broadbridge, Adelina M.; Maxwell, Gillian A.; Ogden, Susan M.
2007-01-01
Purpose: The purpose of this paper is to examine Generation Y, potential graduate entrants to UK retailing, in respect of their job experiences, career perceptions and initial employment expectations. Design/methodology/approach: Utilising qualitative research methods, an exploratory study was undertaken with 33 students (all of whom fell into the…
Potentialities of HTS Superconductor Technology in Telecommunication Satellites
2005-07-13
satellites de télécommunications, utilisant des composants supraconducteurs à haute température critique et de l’électronique refroidie sont présentés... supraconducteur ) is the focal array of a receiving antenna (FAFR). The target application is a receive multi-beam satellite antenna in Ka-band. Small
A Study into the Effects of eLearning on Higher Education
ERIC Educational Resources Information Center
Singh, Gurmak; O'Donoghue, John; Worton, Harvey
2005-01-01
The Internet is a technological development that has the potential to change not only the way society retains and accesses knowledge but also to transform and restructure traditional models of higher education, particularly the delivery and interaction in and with course materials and associated resources. Utilising the Internet to deliver…
NASA Astrophysics Data System (ADS)
Saravanan, A. V. Sai; Abishek, B.; Anantharaj, R.
2018-04-01
The fundamental natures of the molecular level interaction and charge transfer between specific radioactive elements and ionic liquids of 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([BMIM]+[NTf2]-), 1-Butyl-3-methylimidazolium ethylsulfate ([BMIM]+[ES]-) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]+[BF4]-) were investigated utilising HF theory and B3LYP hybrid DFT. The ambiguity in reaction mechanism of the interacting species dictates to employ Effective Core Potential (ECP) basis sets such as UGBS, SDD, and SDDAll to account for the relativistic effects of deep core electrons in the system involving potential, heavy and hazardous radioactive elements present in nuclear waste. The SCF energy convergence of each system validates the characterisation of the molecular orbitals as a linear combination of atomic orbitals utilising fixed MO coefficients and the optimized geometry of each system is visualised based on which Mulliken partial charge analysis is carried out to account for the polarising behaviour of the radioactive element and charge transfer between the IL phase by comparison with the bare IL species.
Ramos-Morales, E; Rossi, G; Cattin, M; Jones, E; Braganca, R; Newbold, C J
2018-03-01
Due to the antimicrobial activity of flavonoids, it has been suggested that they may provide a possible alternative to antibiotics to stimulate productivity and reduce the environmental load of ruminant agriculture. We hypothesised that an extract of liquorice, rich in prenylated isoflavonoids and particularly glabridin, might potentially improve the efficiency of nitrogen utilisation and reduce methane production in the rumen. When added to a long-term rumen simulating fermentor (RUSITEC), liquorice extract at 1 g L-1 decreased ammonia production (-51%; P < 0.001) without affecting the overall fermentation process. When added at 2 g L-1, decreases in not only ammonia production (-77%; P < 0.001), but also methane (-27%; P = 0.039) and total VFA production (-15%; P = 0.003) were observed. These effects in fermentation were probably related to a decrease in protozoa numbers, a less diverse bacteria population as well as changes in the structure of both the bacterial and archaeal communities. The inclusion of an isoflavonoid-rich extract from liquorice in the diet may potentially improve the efficiency of the feed utilisation by ruminants.
Banke-Thomas, Aduragbemi; Banke-Thomas, Oluwasola; Kivuvani, Mwikali; Ameh, Charles Anawo
2017-06-01
Kenya has one of the highest adolescent fertility rates in East-Africa, estimated at 106 births per 1000 females aged 15-19years. In addition to promoting safe sexual behaviour, utilisation of maternal health services (MHS) is essential to prevent poor outcomes of pregnancy and childbirth. To ensure optimum planning, particularly in the context of the Sustainable Development Goals, this study assesses the current service utilisation patterns of Kenyan adolescent mothers and the factors that affect this utilisation. Using data from the recently published 2014 Kenya Demographic Health Survey, we collected demographic and utilisation data of all three MHSs (antenatal care (ANC), skilled birth attendance (SBA) and postnatal care (PNC)) of adolescent mothers aged 15-19years. We then conducted bivariate and multivariate analyses to test associations between selected demographic and service utilisation variables. Our findings showed that half of Kenyan adolescent mothers have had their first birth by the age of 16. MHS utilisation rates amongst Kenyan adolescent mothers were 93%, 65%, 92% for ANC, SBA and PNC respectively. Mother's education, religion, ethnicity, place of residence, wealth quintile, mass media exposure, and geographical region were significant predictors for both ANC and SBA utilisation. Education level of partner was significant for ANC utilisation while parity was significant for both SBA and PNC. Adolescent MHS utilisation is not optimum in Kenya. More work that includes affordable care provision, cultural re-orientation, targeted mass-media campaigns and male involvement in care need to be done with emphasis on the most disadvantaged areas. Copyright © 2017 Elsevier B.V. All rights reserved.
Best Practices in Zoning for Solar | State, Local, and Tribal Governments |
will remove potential barriers. For example: Solar Energy System: solar energy devices or design the electricity, and where it can be used. For example, requiring that accessory use solar electricity time. Resources: Planning and Zoning for Solar in North Carolina, p. 19; Example: Fort Collins, CO
Frias, Patricio A; Oster, Matthew; Daley, Patricia A; Boris, Jeffrey R
2016-03-01
We sought to benchmark the utilisation of echocardiography in the outpatient evaluation of heart murmurs by evaluating two large paediatric cardiology centres. Although criteria exist for appropriate use of echocardiography, there are no benchmarking data demonstrating its utilisation. We performed a retrospective cohort study of outpatients aged between 0 and 18 years at the Sibley Heart Center Cardiology and the Children's Hospital of Philadelphia Division of Cardiology, given a sole diagnosis of "innocent murmur" from 1 July, 2007 to 31 October, 2010. Using internal claims data, we compared the utilisation of echocardiography according to centre, patient age, and physician years of service. Of 23,114 eligible patients (Sibley Heart Center Cardiology: 12,815, Children's Hospital of Philadelphia Division of Cardiology: 10,299), 43.1% (Sibley Heart Center Cardiology: 45.2%, Children's Hospital of Philadelphia Division of Cardiology: 40.4%; p1-5 years had the lowest utilisation (32.7%). In two large paediatric cardiology practices, the overall utilisation of echocardiography by physicians with a sole diagnosis of innocent murmur was similar. There was significant and similar variability in utilisation by provider at both centres. Although these data serve as initial benchmarking, the variability in utilisation highlights the importance of appropriate use criteria.
Adeleke, Rasheed; Cloete, T E; Khasa, D P
2012-03-01
With one of the largest iron ore deposits in the world, South Africa is recognised to be among the top ten biggest exporters of iron ore. Increasing demand and consumption of this mineral triggered search for processing technologies, which can be utilised to "purify" the low-grade iron ore minerals that contain high levels of unwanted potassium (K) and phosphorus (P). This study investigated a potential biological method that can be further developed for the full biobeneficiation of low-grade iron ore minerals. Twenty-three bacterial strains that belong to Proteobacteria, Firmicutes, Bacteroidetes and Actinobateria were isolated from the iron ore minerals and identified with sequence homology and phylogenetic methods. The abilities of these isolates to lower the pH of the growth medium and solubilisation of tricalcium phosphate were used to screen them as potential mineral solubilisers. Eight isolates were successfully screened with this method and utilised in shake flask experiments using iron ore minerals as sources of K and P. The shake flask experiments revealed that all eight isolates have potentials to produce organic acids that aided the solubilisation of the iron ore minerals. In addition, all eight isolates produced high concentrations of gluconic acid followed by relatively lower concentrations of acetic, citric and propanoic acid. Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) analyses also indicated extracellular polymeric substances could play a role in mineral solubilisation.
Low- and Moderate-Income Residences Can Help Modernize the U.S. Electric
of the United States, divided by county, is color-coded by the total solar technical potential Chicago region, show the greatest technical potential. The report breaks down the total potential for rooftop solar could contribute up to 42 percent of all rooftop technical potential in the residential
Integrated nuclear data utilisation system for innovative reactors.
Yamano, N; Hasegawa, A; Kato, K; Igashira, M
2005-01-01
A five-year research and development project on an integrated nuclear data utilisation system was initiated in 2002, for developing innovative nuclear energy systems such as accelerator-driven systems. The integrated nuclear data utilisation system will be constructed as a modular code system, which consists of two sub-systems: the nuclear data search and plotting sub-system, and the nuclear data processing and utilisation sub-system. The system will be operated with a graphical user interface in order to enable easy utilisation through the Internet by both nuclear design engineers and nuclear data evaluators. This paper presents an overview of the integrated nuclear data utilisation system, describes the development of a prototype system to examine the operability of the user interface and discusses specifications of the two sub-systems.
Correlation of ISS Electric Potential Variations with Mission Operations
NASA Technical Reports Server (NTRS)
Willis, Emily M.; Minow, Joseph I.; Parker, Linda Neergaard
2014-01-01
Spacecraft charging on the International Space Station (ISS) is caused by a complex combination of the low Earth orbit plasma environment, space weather events, operations of the high voltage solar arrays, and changes in the ISS configuration and orbit parameters. Measurements of the ionospheric electron density and temperature along the ISS orbit and variations in the ISS electric potential are obtained from the Floating Potential Measurement Unit (FPMU) suite of four plasma instruments (two Langmuir probes, a Floating Potential Probe, and a Plasma Impedance Probe) on the ISS. These instruments provide a unique capability for monitoring the response of the ISS electric potential to variations in the space environment, changes in vehicle configuration, and operational solar array power manipulation. In particular, rapid variations in ISS potential during solar array operations on time scales of tens of milliseconds can be monitored due to the 128 Hz sample rate of the Floating Potential Probe providing an interesting insight into high voltage solar array interaction with the space plasma environment. Comparing the FPMU data with the ISS operations timeline and solar array data provides a means for correlating some of the more complex and interesting ISS electric potential variations with mission operations. In addition, recent extensions and improvements to the ISS data downlink capabilities have allowed more operating time for the FPMU than ever before. The FPMU was operated for over 200 days in 2013 resulting in the largest data set ever recorded in a single year for the ISS. In this paper we provide examples of a number of the more interesting ISS charging events observed during the 2013 operations including examples of rapid charging events due to solar array power operations, auroral charging events, and other charging behavior related to ISS mission operations.
Correlation of ISS Electric Potential Variations with Mission Operations
NASA Technical Reports Server (NTRS)
Willis, Emily M.; Minow, Joseph I.; Parker, Linda Neergaard
2014-01-01
Spacecraft charging on the International Space Station (ISS) is caused by a complex mix of the low Earth orbit plasma environment, space weather events, operations of the high voltage solar arrays, and changes in the ISS configuration and orbit parameters. Measurements of the ionospheric electron density and temperature along the ISS orbit and variations in the ISS electric potential are obtained from the Floating Potential Measurement Unit (FPMU) suite of four plasma instruments (two Langmuir probes, a Floating Potential Probe, and a Plasma Impedance Probe) on the ISS. These instruments provide a unique capability for monitoring the response of the ISS electric potential to variations in the space environment, changes in vehicle configuration, and operational solar array power manipulation. In particular, rapid variations in ISS potential during solar array operations on time scales of tens of milliseconds can be monitored due to the 128 Hz sample rate of the Floating Potential Probe providing an interesting insight into high voltage solar array interaction with the space plasma environment. Comparing the FPMU data with the ISS operations timeline and solar array data provides a means for correlating some of the more complex and interesting ISS electric potential variations with mission operations. In addition, recent extensions and improvements to the ISS data downlink capabilities have allowed more operating time for the FPMU than ever before. The FPMU was operated for over 200 days in 2013 resulting in the largest data set ever recorded in a single year for the ISS. This presentation will provide examples of a number of the more interesting ISS charging events observed during the 2013 operations including examples of rapid charging events due to solar array power operations, auroral charging events, and other charging behavior related to ISS mission operations.
NREL Screens Universities for Solar and Battery Storage Potential
DOE Office of Scientific and Technical Information (OSTI.GOV)
Elgqvist, Emma M
In support of the U.S. Department of Energy's SunShot initiative, NREL provided solar photovoltaic (PV) screenings in 2016 and 2017 for universities seeking to go solar. Fifteen universities were selected for screenings based on campus solar and sustainability goals, plans for future solar projects and solar deployment capacity (megawatts), regional diversity, energy costs, and availability of campus energy data for the analysis.
Panigrahi, Shrabani; Jana, Santanu; Calmeiro, Tomás; Nunes, Daniela; Martins, Rodrigo; Fortunato, Elvira
2017-10-24
Highly luminescent CsPbBr 3 perovskite quantum dots (QDs) have gained huge attention in research due to their various applications in optoelectronics, including as a light absorber in photovoltaic solar cells. To improve the performances of such devices, it requires a deeper knowledge on the charge transport dynamics inside the solar cell, which are related to its power-conversion efficiency. Here, we report the successful fabrication of an all-inorganic CsPbBr 3 perovskite QD sensitized solar cell and the imaging of anomalous electrical potential distribution across the layers of the cell under different illuminations using Kelvin probe force microscopy. Carrier generation, separation, and transport capacity inside the cells are dependent on the light illumination. Large differences in surface potential between electron and hole transport layers with unbalanced carrier separation at the junction have been observed under white light (full solar spectrum) illumination. However, under monochromatic light (single wavelength of solar spectrum) illumination, poor charge transport occurred across the junction as a consequence of less difference in surface potential between the active layers. The outcome of this study provides a clear idea on the carrier dynamic processes inside the cells and corresponding surface potential across the layers under the illumination of different wavelengths of light to understand the functioning of the solar cells and ultimately for the improvement of their photovoltaic performances.
Thin-Film Photovoltaics: Status and Applications to Space Power
NASA Technical Reports Server (NTRS)
Landis, Geoffrey A.; Hepp, Aloysius F.
1991-01-01
The potential applications of thin film polycrystalline and amorphous cells for space are discussed. There have been great advances in thin film solar cells for terrestrial applications; transfer of this technology to space applications could result in ultra low weight solar arrays with potentially large gains in specific power. Recent advances in thin film solar cells are reviewed, including polycrystalline copper iridium selenide and related I-III-VI2 compounds, polycrystalline cadmium telluride and related II-VI compounds, and amorphous silicon alloys. The possibility of thin film multi bandgap cascade solar cells is discussed.
NASA Technical Reports Server (NTRS)
Meyer, F. W.; Barghouty, A. F.
2012-01-01
Solar wind sputtering of the lunar surface helps determine the composition of the lunar exosphere and contributes to surface weathering. To date, only the effects of the two dominant solar wind constituents, H+ and He+, have been considered. The heavier, less abundant solar wind constituents have much larger sputtering yields because they have greater mass (kinetic sputtering) and they are highly charged (potential sputtering) Their contribution to total sputtering can therefore be orders of magnitude larger than their relative abundances would suggest
Solar-Wind Protons and Heavy Ions Sputtering of Lunar Surface Materials
DOE Office of Scientific and Technical Information (OSTI.GOV)
Barghouty, N.; Meyer, Fred W; Harris, Peter R
2011-01-01
Lunar surface materials are exposed to {approx}1 keV/amu solar-wind protons and heavy ions on almost continuous basis. As the lunar surface consists of mostly oxides, these materials suffer, in principle, both kinetic and potential sputtering due to the actions of the solar-wind ions. Sputtering is an important mechanism affecting the composition of both the lunar surface and its tenuous exosphere. While the contribution of kinetic sputtering to the changes in the composition of the surface layer of these oxides is well understood and modeled, the role and implications of potential sputtering remain unclear. As new potential-sputtering data from multi-charged ionsmore » impacting lunar regolith simulants are becoming available from Oak Ridge National Laboratory's MIRF, we examine the role and possible implications of potential sputtering of Lunar KREEP soil. Using a non-equilibrium model we demonstrate that solar-wind heavy ions induced sputtering is critical in establishing the timescale of the overall solar-wind sputtering process of the lunar surface. We also show that potential sputtering leads to a more pronounced and significant differentiation between depleted and enriched surface elements. We briefly discuss the impacts of enhanced sputtering on the composition of the regolith and the exosphere, as well as of solar-wind sputtering as a source of hydrogen and water on the moon.« less
Solar Energy Technologies and the Utilization on Native American Tribal Lands
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hall, Kathryn
As an undergraduate researcher, I worked on a new technology called nanofluid-based direct absorption solar collectors (DASC) which is a type of solar water heater that has the potential to be more efficient than traditional solar water heaters. Because of my experience with this type of technology, I decided to look into other types of solar energy technologies which could be used on Native American tribal lands. Some types of solar energy technologies that I wanted to focus on are photovoltaic solar energy systems, passive solar design, and solar water heaters.
Solar energy in California industry - Applications, characteristics and potential
NASA Technical Reports Server (NTRS)
Barbieri, R. H.; Pivirotto, D. S.
1978-01-01
Results of a survey to determine the potential applicability of solar thermal energy to industrial processes in California are presented. It is found that if the heat for all industrial processes at temperatures below 212 F were supplied by solar energy, total state energy consumption could be reduced by 100 trillion Btus (2%), while the use of solar energy in processes between 212 and 350 F could displace 500 trillion Btus. The issues and problems with which solar energy must contend are illustrated by a description of fluid milk processing operations. Solar energy application is found to be technically feasible for processes with thermal energy requirements below 212 F, with design, and degree of technical, economic and management feasibility being site specific. It is recommended that the state provide support for federal and industrial research, development and demonstration programs in order to stimulate acceptance of solar process heat application by industry.
Hoffacker, Madison K; Allen, Michael F; Hernandez, Rebecca R
2017-12-19
Land-cover change from energy development, including solar energy, presents trade-offs for land used for the production of food and the conservation of ecosystems. Solar energy plays a critical role in contributing to the alternative energy mix to mitigate climate change and meet policy milestones; however, the extent that solar energy development on nonconventional surfaces can mitigate land scarcity is understudied. Here, we evaluate the land sparing potential of solar energy development across four nonconventional land-cover types: the built environment, salt-affected land, contaminated land, and water reservoirs (as floatovoltaics), within the Great Central Valley (CV, CA), a globally significant agricultural region where land for food production, urban development, and conservation collide. Furthermore, we calculate the technical potential (TWh year -1 ) of these land sparing sites and test the degree to which projected electricity needs for the state of California can be met therein. In total, the CV encompasses 15% of CA, 8415 km 2 of which was identified as potentially land-sparing for solar energy development. These areas comprise a capacity-based energy potential of at least 17 348 TWh year -1 for photovoltaic (PV) and 2213 TWh year -1 for concentrating solar power (CSP). Accounting for technology efficiencies, this exceeds California's 2025 projected electricity demands up to 13 and 2 times for PV and CSP, respectively. Our study underscores the potential of strategic renewable energy siting to mitigate environmental trade-offs typically coupled with energy sprawl in agricultural landscapes.
NASA Technical Reports Server (NTRS)
Schueler, D. G.
1978-01-01
Although solar energy has the potential of providing a significant source of clean and renewable energy for a variety of applications, it is expected to penetrate the nation's energy economy very slowly. The alternative solar energy technologies which employ direct collection and conversion of solar radiation as briefly described.
NASA Astrophysics Data System (ADS)
Mashaal, Heylal; Gordon, Jeffrey M.
2014-10-01
Solar rectifying antennas constitute a distinct solar power conversion paradigm where sunlight's spatial coherence is a basic constraining factor. In this presentation, we derive the fundamental thermodynamic limit for coherence-limited blackbody (principally solar) power conversion. Our results represent a natural extension of the eponymous Landsberg limit, originally derived for converters that are not constrained by the radiation's coherence, and are irradiated at maximum concentration (i.e., with a view factor of unity to the solar disk). We proceed by first expanding Landsberg's results to arbitrary solar view factor (i.e., arbitrary concentration and/or angular confinement), and then demonstrate how the results are modified when the converter can only process coherent radiation. The results are independent of the specific power conversion mechanism, and hence are valid for diffraction-limited as well as quantum converters (and not just classical heat engines or in the geometric optics regime). The derived upper bounds bode favorably for the potential of rectifying antennas as potentially high-efficiency solar converters.
Singh, Surya Prakash; Sharma, G D
2014-06-01
Dye sensitized solar cells (DSSCs) and bulk heterojunction (BHJ) solar cells have been the subject of intensive academic interest over the past two decades, and significant commercial effort has been directed towards this area with the vison of developing the next generation of low cost solar cells. Materials development has played a vital role in the dramatic improvement of both DSSC and BHJ solar cell performance in the recent years. Organic conjugated polymers and small molecules that absorb solar light in the visible and near infrared (NIR) regions represent a class of emering materials and show a great potential for the use of different optoelectronic devices such as DSSCs and BHJ solar cells. This account describes the emering class of near infrared (NIR) organic polymers and small molecules having donor and acceptors units, and explores their potential applications in the DSSCs and BHJ solar cells. Copyright © 2014 The Chemical Society of Japan and Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Hughes, Declan; Song, Bing
2016-01-01
Craniofacial reconstruction may be a necessary treatment for those who have been affected by trauma, disease, or pathological developmental conditions. The use of stem cell therapy and tissue engineering shows massive potential as a future treatment modality. Currently in the literature, there is a wide variety of published experimental studies utilising the different stem cell types available and the plethora of available scaffold materials. This review investigates different stem cell sources and their unique characteristics to suggest an ideal cell source for regeneration of individual craniofacial tissues. At present, understanding and clinical applications of stem cell therapy remain in their infancy with numerous challenges to overcome. In spite of this, the field displays immense capacity and will no doubt be utilised in future clinical treatments of craniofacial regeneration. PMID:27143979
Dekkera and Brettanomyces growth and utilisation of hydroxycinnamic acids in synthetic media.
Harris, Victoria; Ford, Christopher M; Jiranek, Vladimir; Grbin, Paul R
2008-04-01
Dekkera and Brettanomyces yeast are important spoilage organisms in a number of food and beverage products. Isolates of both genera were cultured in a defined medium and supplemented with hydroxycinnamic acids and vinylphenols to investigate their influence on growth and the formation of ethyl phenol derivatives. The growth rate of Brettanomyces species in the presence of acids was reduced, and no significant conversion to vinyl or ethyl derivatives was observed. The growth rate and substrate utilisation rates of Dekkera anomala and Dekkera bruxellensis yeast differed depending on strain and the acid precursor present. Growth of D. bruxellensis was slowed by the presence of ferulic acid with the addition of 1 mM ferulic acid completely inhibiting growth. This study provides an insight into the spoilage potential of these organisms and possible control strategies involving hydroxycinnamic acids.
Kinetic and Potential Sputtering of Lunar Regolith: Contribution of Solar-Wind Heavy Ions
NASA Technical Reports Server (NTRS)
Meyer, F. W.; Harris, P. R.; Meyer, H. M., III; Hijiazi, H.; Barghouty, A. F.
2013-01-01
Sputtering of lunar regolith by protons as well as solar-wind heavy ions is considered. From preliminary measurements of H+, Ar+1, Ar+6 and Ar+9 ion sputtering of JSC-1A AGGL lunar regolith simulant at solar wind velocities, and TRIM simulations of kinetic sputtering yields, the relative contributions of kinetic and potential sputtering contributions are estimated. An 80-fold enhancement of oxygen sputtering by Ar+ over same-velocity H+, and an additional x2 increase for Ar+9 over same-velocity Ar+ was measured. This enhancement persisted to the maximum fluences investigated is approximately 1016/cm (exp2). Modeling studies including the enhanced oxygen ejection by potential sputtering due to the minority heavy ion multicharged ion solar wind component, and the kinetic sputtering contribution of all solar wind constituents, as determined from TRIM sputtering simulations, indicate an overall 35% reduction of near-surface oxygen abundance. XPS analyses of simulant samples exposed to singly and multicharged Ar ions show the characteristic signature of reduced (metallic) Fe, consistent with the preferential ejection of oxygen atoms that can occur in potential sputtering of some metal oxides.
New formulation feed method in tariff model of solar PV in Indonesia
NASA Astrophysics Data System (ADS)
Djamal, Muchlishah Hadi; Setiawan, Eko Adhi; Setiawan, Aiman
2017-03-01
Geographically, Indonesia has 18 latitudes that correlated strongly with the potential of solar radiation for the implementation of solar photovoltaic (PV) technologies. This is becoming the basis assumption to develop a proportional model of Feed In Tariff (FIT), consequently the FIT will be vary, according to the various of latitudes in Indonesia. This paper proposed a new formulation of solar PV FIT based on the potential of solar radiation and some independent variables such as latitude, longitude, Levelized Cost of Electricity (LCOE), and also socio-economic. The Principal Component Regression (PCR) method is used to analyzed the correlation of six independent variables C1-C6 then three models of FIT are presented. Model FIT-2 is chosen because it has a small residual value and has higher financial benefit compared to the other models. This study reveals the value of variable FIT associated with solar energy potential in each region, can reduce the total FIT to be paid by the state around 80 billion rupiahs in 10 years of 1 MW photovoltaic operation at each 34 provinces in Indonesia.
Jiang, Chun-Sheng; Yang, Mengjin; Zhou, Yuanyuan; To, Bobby; Nanayakkara, Sanjini U.; Luther, Joseph M.; Zhou, Weilie; Berry, Joseph J.; van de Lagemaat, Jao; Padture, Nitin P.; Zhu, Kai; Al-Jassim, Mowafak M.
2015-01-01
Organometal–halide perovskite solar cells have greatly improved in just a few years to a power conversion efficiency exceeding 20%. This technology shows unprecedented promise for terawatt-scale deployment of solar energy because of its low-cost, solution-based processing and earth-abundant materials. We have studied charge separation and transport in perovskite solar cells—which are the fundamental mechanisms of device operation and critical factors for power output—by determining the junction structure across the device using the nanoelectrical characterization technique of Kelvin probe force microscopy. The distribution of electrical potential across both planar and porous devices demonstrates p–n junction structure at the TiO2/perovskite interfaces and minority-carrier diffusion/drift operation of the devices, rather than the operation mechanism of either an excitonic cell or a p-i-n structure. Combining the potential profiling results with solar cell performance parameters measured on optimized and thickened devices, we find that carrier mobility is a main factor that needs to be improved for further gains in efficiency of the perovskite solar cells. PMID:26411597
Jiang, Chun-Sheng; Yang, Mengjin; Zhou, Yuanyuan; ...
2015-09-28
Organometal–halide perovskite solar cells have greatly improved in just a few years to a power conversion efficiency exceeding 20%. This technology shows unprecedented promise for terawatt-scale deployment of solar energy because of its low-cost, solution-based processing and earth-abundant materials. We have studied charge separation and transport in perovskite solar cells—which are the fundamental mechanisms of device operation and critical factors for power output—by determining the junction structure across the device using the nanoelectrical characterization technique of Kelvin probe force microscopy. Moreover, the distribution of electrical potential across both planar and porous devices demonstrates p–n junction structure at the TiO2/perovskite interfacesmore » and minority-carrier diffusion/drift operation of the devices, rather than the operation mechanism of either an excitonic cell or a p-i-n structure. When we combined the potential profiling results with solar cell performance parameters measured on optimized and thickened devices, we find that carrier mobility is a main factor that needs to be improved for further gains in efficiency of the perovskite solar cells.« less
Performance optimization of evacuated tube collector for solar cooling of a house in hot climate
NASA Astrophysics Data System (ADS)
Ghoneim, Adel A.
2018-02-01
Evacuating the space connecting cover and absorber significantly improves evacuated tube collector (ETC) performance. So, ETCs are progressively utilised all over the world. The main goal of current study is to explore ETC thermal efficiency in hot and severe climate like Kuwait weather conditions. A collector test facility was installed to record ETC thermal performance for one-year period. An extensively developed model for ETCs is presented, employing complete optical and thermal assessment. This study analyses separately optics and heat transfer in the evacuated tubes, allowing the analysis to be extended to different configurations. The predictions obtained are in agreement with experimental. The optimum collector parameters (collector tube length and diameter, mass flow rate and collector tilt angle) are determined. The present results indicate that the optimum tube length is 1.5 m, as at this length a significant improvement is achieved in efficiency for different tube diameters studied. Finally, the heat generated from ETCs is used for solar cooling of a house. Results of the simulation of cooling system indicate that an ETC of area 54 m2, tilt angle of 25° and storage tank volume of 2.1 m3 provides 80% of air-conditioning demand in a house located in Kuwait.
Floodwater utilisation values of wetland services - a case study in Northeastern China
NASA Astrophysics Data System (ADS)
Lü, S. B.; Xu, S. G.; Feng, F.
2012-02-01
Water plays a significant role in wetlands. Floodwater utilisation in wetlands brings a wide range of wetland services, from goods production and water regulation to animal protection and aesthetics related to water supply in wetlands. In this study, the floodwater utilisation values of wetland services were estimated within the Momoge wetland and Xianghai wetland in western Jilin province of northeastern China. From 2003 to 2008, the floodwater diverted from the Nenjiang and Tao'er River is 381 million m3, which translates into a monetary value of approximately 1.35 billion RMB in 2008 (RMB: Chinese Currency, RMB 6.80 = US 1), and the ratio of economic value, eco-environmental value, and social value is 1:12:2. Besides the monetary value of the water itself, excessive floodwater utilisation may bring losses to wetlands; the threshold floodwater utilisation volumes in wetlands are discussed. Floodwater utilisation can alleviate water shortages in wetlands, and the evaluation of floodwater utilisation in wetland services in monetary terms is a guide for the effective use of the floodwater resources and for the conservation of wetlands.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cheng, J. -J.; Chang, Y. -S.; Hartmann, H.
2013-09-01
This report presents a general methodology for obtaining preliminary estimates of the potential human health risks associated with developing a utility-scale solar energy facility on a contaminated site, based on potential exposures to contaminants in soils (including transport of those contaminants into the air).
ERIC Educational Resources Information Center
Maloney, Stephen; Moss, Alan; Ilic, Dragan
2014-01-01
Social Networking Sites (SNS) have seen exponential growth in recent years. The high utilisation of SNS by tertiary students makes them an attractive tool for educational institutions. This study aims to identify health professional students' use and behaviours with SNS, including students' perspectives on potential applications within…
Second Life in the Library: An Empirical Study of New Users' Experiences
ERIC Educational Resources Information Center
Clarke, Christopher Peter
2012-01-01
Purpose: This paper aims to examine the experiences of new users of Second Life in order to identify potential barriers and attractors to the expansion of the userbase and therefore the market for in-world information services. Design/methodology/approach: A multi-faceted methodological approach was taken utilising two questionnaires (pre- and…
Mapping the Digital Divide in Britain: Implications for Learning and Education
ERIC Educational Resources Information Center
Eynon, Rebecca
2009-01-01
The internet presents many potential opportunities for people to learn for both formal and informal purposes. However, not everyone is able to make the most of the internet for learning. This paper utilises quantitative nationally representative survey data of internet use in Britain in order to explore the digital divide in relation to learning…
Learning Grammatical Categories from Distributional Cues: Flexible Frames for Language Acquisition
ERIC Educational Resources Information Center
St. Clair, Michelle C.; Monaghan, Padraic; Christiansen, Morten H.
2010-01-01
Numerous distributional cues in the child's environment may potentially assist in language learning, but what cues are useful to the child and when are these cues utilised? We propose that the most useful source of distributional cue is a flexible frame surrounding the word, where the language learner integrates information from the preceding and…
Implicit Segmentation of a Stream of Syllables Based on Transitional Probabilities: An MEG Study
ERIC Educational Resources Information Center
Teinonen, Tuomas; Huotilainen, Minna
2012-01-01
Statistical segmentation of continuous speech, i.e., the ability to utilise transitional probabilities between syllables in order to detect word boundaries, is reflected in the brain's auditory event-related potentials (ERPs). The N1 and N400 ERP components are typically enhanced for word onsets compared to random syllables during active…
Zhang, Shun; Chen, Chen; Zhou, Yangen; Qian, Yumin; Ye, Jing; Xiong, Shiyun; Zhao, Yu; Zhang, Xiaohong
2018-06-27
The rapid deployment of renewable energy is resulting in significant energy security, climate change mitigation, and economic benefits. We demonstrate here the direct solar-energy harvesting and storage in a rechargeable solar-powered redox cell, which can be charged solely by solar irradiation. The cell follows a conventional redox-flow cell design with one integrated TiO 2 photoanode in the cathode side. Direct charging of the cell by solar irradiation results in the conversion of solar energy in to chemical energy. Whereas discharging the cell leads to the release of chemical energy in the form of electricity. The cell integrates energy conversion and storage processes in a single device, making the solar energy directly and efficiently dispatchable. When using redox couples of Br 2 /Br - and I 3 - /I - in the cathode side and anode side, respectively, the cell can be directly charged upon solar irradiation, yielding a discharge potential of 0.5 V with good round-trip efficiencies. This design is expected to be a potential alternative toward the development of affordable, inexhaustible, and clean solar-energy technologies.
Potential of Securitization in Solar PV Finance
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lowder, Travis; Mendelsohn, Michael
This report aims to demonstrate, hypothetically and at a high level, what volumes of solar deployment could be supported given solar industry access to the capital markets in the form of security issuance. Securitization is not anticipated to replace tax equity in the near- to mid-term, but it could provide an additional source of funds that would be comparatively inexpensive and could reduce the weighted average cost of capital for a given solar project or portfolio. Thus, the potential to securitize solar assets and seek financing in the capital markets could help to sustain the solar industry when the investmentmore » tax credit (ITC) -- one of the federal incentives that has leveraged billions of dollars of private capital in the solar industry -- drops from 30% to 10% at the close of 2016. The report offers analysis on the size of the U.S. third-party financed solar market, as well as on the volumes (in MW) of solar asset origination possible through a $100 million securitization fund (assuming no overcollateralization). It also provides data on the size of the relevant securities markets and how the solar asset class may fit into these markets.« less
Is Solar Energy the Fuel of the Future?
ERIC Educational Resources Information Center
Cetincelik, Mauammer
1974-01-01
Describes the present distribution of solar energy, traces its use through history, explores its potential utilization in the future, and presents the effects of the use of solar energy on pollution. (GS)
NASA Astrophysics Data System (ADS)
Gresham, J. B.; Kriz, T. A.
1981-03-01
To achieve widespread application in the industrial and utility sectors, solar systems must be economically competitive. Economic viability is, in turn, determined by a number of supporting criteria, ranging from system reliability to dispatch characteristics to how the system supports the main product line. In addition, solar systems possess some inherent attributes that may render some of the traditional supporting criteria inappropriate or require their redefinition. Those criteria and their relation to the solar investments are discussed in three steps. First, the main concerns and preferences of the potential users, as identified in recent SERI studies, are identified. Second, the equitability of the resulting decision criteria for solar investments are examined. Finally, the implications of these criteria for solar energy's penetration into these markets are discussed.
Assimilation of organic and inorganic nutrients by Erica root fungi from the fynbos ecosystem.
Bizabani, Christine; Dames, Joanna Felicity
2016-03-01
Erica dominate the fynbos ecosystem, which is characterized by acidic soils that are rich in organic matter. The ericaceae associate with ericoid mycorrhizal (ERM) fungi for survival. In this study fungal biomass accumulation in vitro was used to determine nutrient utilisation of various inorganic and organic substrates. This is an initial step towards establishment of the ecological roles of typical ERM fungi and other root fungi associated with Erica plants, with regard to host nutrition. Meliniomyces sp., Acremonium implicatum, Leohumicola sp., Cryptosporiopsis erica, Oidiodendron maius and an unidentified Helotiales fungus were selected from fungi previously isolated and identified from Erica roots. Sole nitrogen sources ammonium, nitrate, arginine and Bovine Serum Albumin (BSA) were tested. Meliniomyces and Leohumicola species were able to utilise BSA effectively. Phosphorus nutrition was tested using orthophosphate, sodium inositol hexaphosphate and DNA. Most isolates preferred orthophosphate. Meliniomyces sp. and A. implicatum were able to accumulate significant biomass using DNA. Carbon utilisation was tested using glucose, cellobiose, carboxymethylcellulose, pectin and tannic acid substrates. All fungal isolates produced high biomass on glucose and cellobiose. The ability to utilize organic nutrient sources in culture, illustrates their potential role of these fungi in host nutrition in the fynbos ecosystem. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.
Simba, Daudi O; Mwangu, Mughwira
2004-12-01
Information Communication Technology (ICT) revolution brought opportunities and challenges to developing countries in their efforts to strengthen the Health Management Information Systems (HMIS). In the wake of globalisation, developing countries have no choice but to take advantage of the opportunities and face the challenges. The last decades saw developing countries taking action to strengthen and modernise their HMIS using the existing ICT. Due to poor economic and communication infrastructure, the process has been limited to national and provincial/region levels leaving behind majority of health workers living in remote/rural areas. Even those with access do not get maximum benefit from ICT advancements due to inadequacies in data quality and lack of data utilisation. Therefore, developing countries need to make deliberate efforts to address constraints threatening to increase technology gap between urban minority and rural majority by setting up favourable policies and appropriate strategies. Concurrently, strategies to improve data quality and utilisation should be instituted to ensure that HMIS has positive impact on people's health. Potential strength from private sector and opportunities for sharing experiences among developing countries should be utilised. Short of this, advancement in ICT will continue to marginalise health workers in developing countries especially those living in remote areas.
Benson, Sarah J; Lennard, Christopher J; Maynard, Philip; Hill, David M; Andrew, Anita S; Roux, Claude
2009-06-01
The application of isotopic techniques to investigations requiring the provision of evidence to a Court is limited. The objective of this research was to investigate the application of light stable isotopes and isotope ratio mass spectrometry (IRMS) to solve complex forensic cases by providing a level of discrimination not achievable utilising traditional forensic techniques. Due to the current threat of organic peroxide explosives, such as triacetone triperoxide (TATP), research was undertaken to determine the potential of IRMS to differentiate samples of TATP that had been manufactured utilising different starting materials and/or manufacturing processes. In addition, due to the prevalence of pentaerythritoltetranitrate (PETN) in detonators, detonating cord, and boosters, the potential of the IRMS technique to differentiate PETN samples from different sources was also investigated. Carbon isotope values were measured in fourteen TATP samples, with three definite groups appearing in the initial sample set based on the carbon data alone. Four additional TATP samples (in a second set of samples) were distinguishable utilising the carbon and hydrogen isotopic compositions individually, and also in combination with the oxygen isotope values. The 3D plot of the carbon, oxygen and hydrogen data demonstrated the clear discrimination of the four samples of TATP. The carbon and nitrogen isotope values measured from fifteen PETN samples, allowed samples from different sources to be readily discriminated. This paper demonstrates the successful application of IRMS to the analysis of explosives of forensic interest to assist in discriminating samples from different sources. This research represents a preliminary evaluation of the IRMS technique for the measurement of stable isotope values in TATP and PETN samples, and supports the dedication of resources for a full evaluation of this application in order to achieve Court reportable IRMS results.
Clark, Malcolm W; Despland, Laure M; Lake, Neal J; Yee, Lachlan H; Anstoetz, Manuela; Arif, Elisabeth; Parr, Jeffery F; Doumit, Philip
2017-04-01
Sugarcane bagasse ash re-utilisation has been advocated as a silica-rich feed for zeolites, pozzolans in cements and concretes, and geopolymers. However, many papers report variable success with the incorporation of such materials in these products as the ash can be inconsistent in nature. Therefore, understanding what variables affect the ash quality in real mills and understanding the processes to characterise ashes is critical in predicting successful ash waste utilisation. This paper investigated sugarcane bagasse ash from three sugar mills (Northern NSW, Australia) where two are used for the co-generation of electricity. Data shows that the burn temperatures of the bagasse in the high-efficiency co-generation boilers are much higher than those reported at the temperature measuring points. Silica polymorph transitions indicate the high burn temperatures of ≈1550 °C, produces ash dominated α -quartz rather than expected α-cristobilite and amorphous silica; although α-cristobilite, and amorphous silica are present. Furthermore, burn temperatures must be ≤1700 °C, because of the absence of lechatelierite where silica fusing and globulisation dominates. Consequently, silica-mineralogy changes deactivate the bagasse ash by reducing silica solubility, thus making bagasse ash utilisation in synthetic zeolites, geopolymers, or a pozzolanic material in mortars and concretes more difficult. For the ashes investigated, use as a filler material in cements and concrete has the greatest potential. Reported mill boiler temperatures discrepancies and the physical characteristics of the ash, highlight the importance of accurate temperature monitoring at the combustion seat if bagasse ash quality is to be prioritised to ensure a usable final ash product.
Nelson, Jenny; Emmott, Christopher J M
2013-08-13
Solar power represents a vast resource which could, in principle, meet the world's needs for clean power generation. Recent growth in the use of photovoltaic (PV) technology has demonstrated the potential of solar power to deliver on a large scale. Whilst the dominant PV technology is based on crystalline silicon, a wide variety of alternative PV materials and device concepts have been explored in an attempt to decrease the cost of the photovoltaic electricity. This article explores the potential for such emerging technologies to deliver cost reductions, scalability of manufacture, rapid carbon mitigation and new science in order to accelerate the uptake of solar power technologies.
Allegrini, E; Butera, S; Kosson, D S; Van Zomeren, A; Van der Sloot, H A; Astrup, T F
2015-04-01
Residues from industrial processes and waste management systems (WMSs) have been increasingly reutilised, leading to landfilling rate reductions and the optimisation of mineral resource utilisation in society. Life cycle assessment (LCA) is a holistic methodology allowing for the analysis of systems and products and can be applied to waste management systems to identify environmental benefits and critical aspects thereof. From an LCA perspective, residue utilisation provides benefits such as avoiding the production and depletion of primary materials, but it can lead to environmental burdens, due to the potential leaching of toxic substances. In waste LCA studies where residue utilisation is included, leaching has generally been neglected. In this study, municipal solid waste incineration bottom ash (MSWI BA) was used as a case study into three LCA scenarios having different system boundaries. The importance of data quality and parameter selection in the overall LCA results was evaluated, and an innovative method to assess metal transport into the environment was applied, in order to determine emissions to the soil and water compartments for use in an LCA. It was found that toxic impacts as a result of leaching were dominant in systems including only MSWI BA utilisation, while leaching appeared negligible in larger scenarios including the entire waste system. However, leaching could not be disregarded a priori, due to large uncertainties characterising other activities in the scenario (e.g. electricity production). Based on the analysis of relevant parameters relative to leaching, and on general results of the study, recommendations are provided regarding the use of leaching data in LCA studies. Copyright © 2014 Elsevier Ltd. All rights reserved.
Apelin targets gut contraction to control glucose metabolism via the brain.
Fournel, Audren; Drougard, Anne; Duparc, Thibaut; Marlin, Alysson; Brierley, Stuart M; Castro, Joel; Le-Gonidec, Sophie; Masri, Bernard; Colom, André; Lucas, Alexandre; Rousset, Perrine; Cenac, Nicolas; Vergnolle, Nathalie; Valet, Philippe; Cani, Patrice D; Knauf, Claude
2017-02-01
The gut-brain axis is considered as a major regulatory checkpoint in the control of glucose homeostasis. The detection of nutrients and/or hormones in the duodenum informs the hypothalamus of the host's nutritional state. This process may occur via hypothalamic neurons modulating central release of nitric oxide (NO), which in turn controls glucose entry into tissues. The enteric nervous system (ENS) modulates intestinal contractions in response to various stimuli, but the importance of this interaction in the control of glucose homeostasis via the brain is unknown. We studied whether apelin, a bioactive peptide present in the gut, regulates ENS-evoked contractions, thereby identifying a new physiological partner in the control of glucose utilisation via the hypothalamus. We measured the effect of apelin on electrical and mechanical duodenal responses via telemetry probes and isotonic sensors in normal and obese/diabetic mice. Changes in hypothalamic NO release, in response to duodenal contraction modulated by apelin, were evaluated in real time with specific amperometric probes. Glucose utilisation in tissues was measured with orally administrated radiolabeled glucose. In normal and obese/diabetic mice, glucose utilisation is improved by the decrease of ENS/contraction activities in response to apelin, which generates an increase in hypothalamic NO release. As a consequence, glucose entry is significantly increased in the muscle. Here, we identify a novel mode of communication between the intestine and the hypothalamus that controls glucose utilisation. Moreover, our data identified oral apelin administration as a novel potential target to treat metabolic disorders. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
Beattie, Tara S H; Bhattacharjee, Parinita; Suresh, M; Isac, Shajy; Ramesh, B M; Moses, Stephen
2012-10-01
Despite high HIV prevalence rates among most-at-risk groups, utilisation of HIV testing, treatment and care services was relatively low in Karnataka prior to 2008. The authors aimed to understand the barriers to and identify potential solutions for improving HIV service utilisation. Focus group discussions were carried out among homogeneous groups of female sex workers, men who have sex with men and transgenders, and programme peer educators in six districts across Karnataka in March and April 2008. 26 focus group discussions were conducted, involving 302 participants. Participants had good knowledge about HIV and HIV voluntary counselling and testing (VCT) services, but awareness of other HIV services was low. The fear of the psychological impact of a positive HIV test result and the perceived repercussions of being seen accessing HIV services were key personal and interpersonal barriers to HIV service utilisation. Previous experiences of discrimination at government healthcare services, coupled with discriminatory attitudes and behaviours by VCT staff, were key structural barriers to VCT service uptake among those who had not been HIV tested. Among those who had used government-managed prevention of parent to child transmission and antiretroviral treatment services, poor physical facilities, long waiting times, lack of available treatment, the need to give bribes to receive care and discriminatory attitudes of healthcare staff presented additional structural barriers. Embedding some HIV care services within existing programmes for vulnerable populations, as well as improving service quality at government facilities, are suggested to help overcome the multiple barriers to service utilisation. Increasing the uptake of HIV testing, treatment and care services is key to improving the quality and longevity of the lives of HIV-infected individuals.
Macronutrient supply, uptake and recycling in the coastal ocean of the west Antarctic Peninsula
NASA Astrophysics Data System (ADS)
Henley, Sian F.; Tuerena, Robyn E.; Annett, Amber L.; Fallick, Anthony E.; Meredith, Michael P.; Venables, Hugh J.; Clarke, Andrew; Ganeshram, Raja S.
2017-05-01
Nutrient supply, uptake and cycling underpin high primary productivity over the continental shelf of the west Antarctic Peninsula (WAP). Here we use a suite of biogeochemical and isotopic data collected over five years in northern Marguerite Bay to examine these macronutrient dynamics and their controlling biological and physical processes in the WAP coastal ocean. We show pronounced nutrient drawdown over the summer months by primary production which drives a net seasonal nitrate uptake of 1.83 mol N m-2 yr-1, equivalent to net carbon uptake of 146 g C m-2 yr-1. High primary production fuelled primarily by deep-sourced macronutrients is diatom-dominated, but non-siliceous phytoplankton also play a role. Strong nutrient drawdown in the uppermost surface ocean has the potential to cause transient nitrogen limitation before nutrient resupply and/or regeneration. Interannual variability in nutrient utilisation corresponds to winter sea ice duration and the degree of upper ocean mixing, implying susceptibility to physical climate change. The nitrogen isotope composition of nitrate (δ15NNO3) shows a utilisation signal during the growing seasons with a community-level net isotope effect of 4.19 ± 0.29‰. We also observe significant deviation of our data from modelled and observed utilisation trends, and argue that this is driven primarily by water column nitrification and meltwater dilution of surface nitrate. This study is important because it provides a detailed description of the nutrient biogeochemistry underlying high primary productivity at the WAP, and shows that surface ocean nutrient inventories in the Antarctic sea ice zone can be affected by intense recycling in the water column, meltwater dilution and sea ice processes, in addition to utilisation in the upper ocean.
Shackley, David Clifford; Whytock, Cameron; Parry, Gareth; Clarke, Laurence; Vincent, Charles; Harrison, Abigail; John, Amber; Provost, Lloyd; Power, Maxine
2017-06-23
Harm from catheter-associated urinary tract infections is a common, potentially avoidable, healthcare complication. Variation in catheter prevalence may exist and provide opportunity for reducing harm, yet to date is poorly understood. This study aimed to determine variation in the prevalence of urinary catheters between patient groups, settings, specialities and over time. A prospective study (July 2012 to April 2016) of National Health Service (NHS) patients surveyed by healthcare professionals, following a standardised protocol to determine the presence of a urinary catheter and duration of use, on 1 day per month using the NHS Safety Thermometer. 1314 organisations (253 NHS trusts) and 9 266 284 patients were included. Overall, 12.9% of patients were catheterised, but utilisation varied. There was higher utilisation of catheters in males (15.7% vs 10.7% p<0.001) and younger people (18-70 year 14.0% vs >70 year 12.8% p<0.001), utilisation was highest in hospital settings (18.6% p<0.001), particularly in critical care (76.6% p<0.001). Most catheters had been in situ <28 days (72.9% p<0.001). No clinically significant changes were seen over time in any setting or specialty. Catheter prevalence in patients receiving NHS-funded care varies according to gender, age, setting and specialty, being most prevalent in males, younger people, hospitals and critical care. Utilisation has changed only marginally over 46 months, and further guidance is indicated to provide clarity for clinicians on the insertion and removal of catheters to supplement the existing guidance on care. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Devitt, Catherine; Boyle, Laura; Teixeira, D L; O'Connell, N E; Hawe, M; Hanlon, Alison
2015-01-01
Currently, there is growing interest in developing ante and post mortem meat inspection (MI) to incorporate measures of pig health and welfare for use as a diagnostic tool on pig farms. However, the success of the development of the MI process requires stakeholder engagement with the process. Knowledge gaps and issues of trust can undermine the effective exchange and utilisation of information across the supply chain. A social science research methodology was employed to establish stakeholder perspectives towards the development of MI to include measures of pig health and welfare. In this paper the findings of semi-structured telephone interviews with 18 pig producers from the Republic of Ireland and Northern Ireland are presented. Producers recognised the benefit of the utilisation of MI data as a health and welfare diagnostic tool. This acknowledgment, however, was undermined for some by dissatisfaction with the current system of MI information feedback, by trust and fairness concerns, and by concerns regarding the extent to which data would be used in the producers' interests. Tolerance of certain animal welfare issues may also have a negative impact on how producers viewed the potential of MI data. The private veterinary practitioner was viewed as playing a vital role in assisting them with the interpretation of MI data for herd health planning. The development of positive relationships based on trust, commitment and satisfaction across the supply chain may help build a positive environment for the effective utilisation of MI data in improving pig health and welfare. The utilisation of MI as a diagnostic tool would benefit from the development of a communication strategy aimed at building positive relationships between stakeholders in the pig industry.
Radiotherapy access in Belgium: How far are we from evidence-based utilisation?
Lievens, Y; De Schutter, H; Stellamans, K; Rosskamp, M; Van Eycken, L
2017-10-01
Underutilisation of radiotherapy has been observed worldwide. To evaluate the current situation in Belgium, optimal utilisation proportions (OUPs) adopted from the European SocieTy for Radiotherapy and Oncology - Health Economics in Radiation Oncology (ESTRO-HERO) project were compared to actual utilisation proportions (AUPs) and with radiotherapy advised during the multidisciplinary cancer team (MDT) meetings. In addition, the impact of independent variables was analysed. AUPs and advised radiotherapy were calculated overall and by cancer type for 110,810 unique cancer diagnoses in 2009-2010. Radiotherapy utilisation was derived from reimbursement data and distinguished between palliative and curative intent external beam radiotherapy (EBRT) and/or brachytherapy (BT). Sensitivity analyses regarding the influence of the follow-up period, the survival length and patient's age were performed. Advised radiotherapy was calculated based on broad treatment categories as reported at MDT meetings. The overall AUP of 37% (39% including BT) was lower than the OUP of 53%, but in line with advised radiotherapy (35%). Large variations by tumour type were observed: in some tumours (e.g. lung and prostate cancer) AUP was considerably lower than OUP, whereas in others there was reasonable concordance (e.g. breast and rectal cancer). Overall, 84% of treatments started within 9 months following diagnosis. Survival time influenced AUP in a cancer type-dependent way. Elderly patients received less radiotherapy. Although the actually delivered radiotherapy in Belgium aligns well to MDT advices, it is lower than the evidence-based optimum. Further analysis of potential barriers is needed for radiotherapy forecasting and planning, and in order to promote adequate access to radiotherapy. Copyright © 2017 Elsevier Ltd. All rights reserved.
Johnsen, Anne Siri; Fattah, Sabina; Sollid, Stephen J M; Rehn, Marius
2016-02-09
This systematic review identifies, describes and appraises the literature describing the utilisation of helicopter emergency medical services (HEMS) in the early medical response to major incidents. Early prehospital phase of a major incident. Systematic literature review performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, the Web of Science, PsycINFO, Scopus, Cinahl, Bibsys Ask, Norart, Svemed and UpToDate were searched using phrases that combined HEMS and 'major incidents' to identify when and how HEMS was utilised. The identified studies were subjected to data extraction and appraisal. The database search identified 4948 articles. Based on the title and abstract, the full text of 96 articles was obtained; of these, 37 articles were included in the review, and an additional five were identified by searching the reference lists of the 37 articles. HEMS was used to transport medical and rescue personnel to the incident and to transport patients to the hospital, especially when the infrastructure was damaged. Insufficient air traffic control, weather conditions, inadequate landing sites and failing communication were described as challenging in some incidents. HEMS was used mainly for patient treatment and to transport patients, personnel and equipment in the early medical management of major incidents, but the optimal utilisation of this specialised resource remains unclear. This review identified operational areas with improvement potential. A lack of systematic indexing, heterogeneous data reporting and weak methodological design, complicated the identification and comparison of incidents, and more systematic reporting is needed. CRD42013004473. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Johnsen, Anne Siri; Fattah, Sabina; Sollid, Stephen J M; Rehn, Marius
2016-01-01
Objective This systematic review identifies, describes and appraises the literature describing the utilisation of helicopter emergency medical services (HEMS) in the early medical response to major incidents. Setting Early prehospital phase of a major incident. Design Systematic literature review performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, the Web of Science, PsycINFO, Scopus, Cinahl, Bibsys Ask, Norart, Svemed and UpToDate were searched using phrases that combined HEMS and ‘major incidents’ to identify when and how HEMS was utilised. The identified studies were subjected to data extraction and appraisal. Results The database search identified 4948 articles. Based on the title and abstract, the full text of 96 articles was obtained; of these, 37 articles were included in the review, and an additional five were identified by searching the reference lists of the 37 articles. HEMS was used to transport medical and rescue personnel to the incident and to transport patients to the hospital, especially when the infrastructure was damaged. Insufficient air traffic control, weather conditions, inadequate landing sites and failing communication were described as challenging in some incidents. Conclusions HEMS was used mainly for patient treatment and to transport patients, personnel and equipment in the early medical management of major incidents, but the optimal utilisation of this specialised resource remains unclear. This review identified operational areas with improvement potential. A lack of systematic indexing, heterogeneous data reporting and weak methodological design, complicated the identification and comparison of incidents, and more systematic reporting is needed. Trial registration number CRD42013004473. PMID:26861938
Hone, Thomas; Lee, John Tayu; Majeed, Azeem; Conteh, Lesong; Millett, Christopher
2017-01-01
Abstract Policy-makers are increasingly considering charging users different fees between primary and secondary care (differential user charges) to encourage utilisation of primary health care in health systems with limited gate keeping. A systematic review was conducted to evaluate the impact of introducing differential user charges on service utilisation. We reviewed studies published in MEDLINE, EMBASE, the Cochrane library, EconLIT, HMIC, and WHO library databases from January 1990 until June 2015. We extracted data from the studies meeting defined eligibility criteria and assessed study quality using an established checklist. We synthesized evidence narratively. Eight studies from six countries met our eligibility criteria. The overall study quality was low, with diversity in populations, interventions, settings, and methods. Five studies examined the introduction of or increase in user charges for secondary care, with four showing decreased secondary care utilisation, and three showing increased primary care utilisation. One study identified an increase in primary care utilisation after primary care user charges were reduced. The introduction of a non-referral charge in secondary care was associated with lower primary care utilisation in one study. One study compared user charges across insurance plans, associating higher charges in secondary care with higher utilisation in both primary and secondary care. Overall, the impact of introducing differential user-charges on primary care utilisation remains uncertain. Further research is required to understand their impact as a demand side intervention, including implications for health system costs and on utilisation among low-income patients. PMID:28453713
Modeling Solar-Wind Heavy-Ions' Potential Sputtering of Lunar KREEP Surface
NASA Technical Reports Server (NTRS)
Barghouty, A. F.; Meyer, F. W.; Harris, R. P.; Adams, J. H., Jr.
2012-01-01
Recent laboratory data suggest that potential sputtering may be an important weathering mechanism that can affect the composition of both the lunar surface and its tenuous exosphere; its role and implications, however, remain unclear. Using a relatively simple kinetic model, we will demonstrate that solar-wind heavy ions induced sputtering of KREEP surfaces is critical in establishing the timescale of the overall solar-wind sputtering process of the lunar surface. We will also also show that potential sputtering leads to a more pronounced and significant differentiation between depleted and enriched surface elements. We briefly discuss the impacts of enhanced sputtering on the composition of the regolith and the exosphere, as well as of solar-wind sputtering as a source of hydrogen and water on the moon.
NASA Astrophysics Data System (ADS)
Teves, Justine; Sola, Eula Fae; Pintor, Ben Hur; Ang, Ma. Rosario Concepcion
2016-10-01
Solar energy is emerging as one of the top options for renewable energy sources in the Philippines, with largescale solar photovoltaic (PV) farms being built all over the country. Solar energy resource in the urban environment has great potential in making a city self-sustaining, but has not been fully explored for the country. In order to represent its potential, reliable resource assessment should be done. This study aims to assess the available solar energy resource in Davao City, a trade and commerce hub in southern Philippines. The functions of GRASS GIS, specifically the r.sun module, in modelling incoming solar radiation is discussed, along with the use of a one-meter LiDAR Digital Surface Model (DSM) and Linke Turbidity coefficients as inputs. The average Julian day of each month was used to compute the Global Horizontal Irradiation (GHI) values under clear-sky or cloudless conditions. To account for the effects of the clouds in the study area, the clear-sky indices (Kc) were computed using data from solar recording stations of the Bureau of Soils and Water Management (BSWM) found within and around the region. These were multiplied to the modelled clear-sky GHI rasters to get the real-sky GHI. The results show that the city's average GHI potential ranges from 2693.79 Wh/m2 and 4453.13 Wh/m2. Average values are particularly higher around the months of March and April, while lower values are seen in the months of November and January. Areas with higher potential are seen in the southern portion of the city, consistent in built-up areas.
The Prospects of Solar Energy for Developing Nations.
ERIC Educational Resources Information Center
Ramachandran, A.; Gururaja, J.
1979-01-01
Discussed are the potential application of solar energy and its possible benefits to developing countries. Various energy needs, including domestic, agricultural, and household, that could be met by using solar energy are discussed. (BT)
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-30
... protecting potential sites for future solar energy development. DATES: Effective Date: This segregation is... public lands that have been identified by the BLM as having the potential for solar energy generation...
NASA Technical Reports Server (NTRS)
Mullan, D. J.
1985-01-01
The first ionization potential (FIP) ordering of elemental abundances in solar energetic particles and in the corona which can both be explained Coulomb effects is discussed. Solar energetic particles (SEP) and coronal gas have anomalous abundances relative to the photosphere. The anomalies are similar in both cases: which led to the conclusion that SEP acceleration is not selective, but merely preserves the source abundances. It is argued that SEP acceleration can be selective, because identical selectivity operates to determine the coronal abundances. The abundance anomalies are ordered by first ionization potential (FIP).
Factors affecting Japanese retirees' healthcare service utilisation in Malaysia: a qualitative study
Kohno, Ayako; Nik Farid, Nik Daliana; Musa, Ghazali; Abdul Aziz, Norlaili; Nakayama, Takeo; Dahlui, Maznah
2016-01-01
Objective While living overseas in another culture, retirees need to adapt to a new environment but often this causes difficulties, particularly among those elderly who require healthcare services. This study examines factors affecting healthcare service utilisation among Japanese retirees in Malaysia. Design We conducted 6 focus group discussions with Japanese retirees and interviewed 8 relevant medical services providers in-depth. Guided by the Andersen Healthcare Utilisation Model, we managed and analysed the data, using QSR NVivo 10 software and the directed content analysis method. Setting We interviewed participants at Japan Clubs and their offices. Participants 30 Japanese retirees who live in Kuala Lumpur and Ipoh, and 8 medical services providers. Results We identified health beliefs, medical symptoms and health insurance as the 3 most important themes, respectively, representing the 3 dimensions within the Andersen Healthcare Utilisation Model. Additionally, language barriers, voluntary health repatriation to Japan and psychological support were unique themes that influence healthcare service utilisation among Japanese retirees. Conclusions The healthcare service utilisation among Japanese retirees in Malaysia could be partially explained by the Andersen Healthcare Utilisation Model, together with some factors that were unique findings to this study. Healthcare service utilisation among Japanese retirees in Malaysia could be improved by alleviating negative health beliefs through awareness programmes for Japanese retirees about the healthcare systems and cultural aspects of medical care in Malaysia. PMID:27006344
Conversion system overview assessment. Volume 1: solar thermoelectrics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Jayadev, T. S.; Henderson, J.; Finegold, J.
1979-08-01
An assessment of thermoelectrics for solar energy conversion is given. There is significant potential for solar thermoelectrics in solar technologies where collector costs are low; e.g., Ocean Thermal Energy Conversion (OTEC) and solar ponds. Reports of two studies by manufacturers assessing the cost of thermoelectric generators in large scale production are included in the appendix and several new concepts thermoelectric systems are presented. (WHK)
Solar power potential of North-east India - A case study for Silchar
NASA Astrophysics Data System (ADS)
Maisanam, Anil; Biswas, Agnimitra; Sharma, Kaushal Kumar
2018-04-01
High energy demand has necessitated search for all possible sources of energy. Conventional energy source is having negative impact on our environment, therefore our attention is focused on renewable energy sources, such as solar, wind, hydro, which are considered to be clean and sustainable energy sources. India has set an ambitious target of producing 175 GW of energy using solar energy. Therefore, it is necessary to estimate the solar potential to observe the feasibility of such project. North-east India is an underdeveloped region of India and due to its geographical location and difficult terrain, many regions are still not electrified. Such regions can be electrified by installing renewable energy based power plants, which can also generate number of jobs hence improving the quality of life and economic condition of the region. The objective of this paper is to estimate the solar power potential of Silchar (Assam, India) and perform a feasibility study for installation of solar-based power plant in the region. In this paper, solar radiation on tilted surface is estimated by using an anisotropic sky model. This radiation data has been used to estimate the PV power output. Finally, feasibility of the PV plant has been verified by mapping with a practical load demand.
False Dawn of a Solar Age: A History of Solar Heating and Power During the Energy Crisis, 1973-1986
NASA Astrophysics Data System (ADS)
Scavo, Jordan Michael
The unfolding of the energy crisis in the early 1970s brought solar to the fore as a topic for national discussion. National dialogues about solar power and national energy policy were one way that Americans interpreted their present and envisioned their nation's future. Yet, policy makers and the general public considered alternative energies, including solar, largely based on the economic conditions of their eras, considerations that, at least until the Reagan era, often transcended political ideologies and parties. Energy prices and the emerging political expediency of replacing fossil fuels were the primary drivers in shaping federal energy policies and public interest during this era. Enthusiasm for solar power often corresponded to the market price of petroleum. By the late 1970s, a lot of people believed the same. Amid growing public enthusiasm, President Carter eventually came out strongly in favor of solar energy, mounting solar panels on the White House and unveiling a plan to procure 20% of the nation's energy from the sun by the year 2000. During the 1960s and 1970s, Americans changed their energy values in response to concerns over environmentalism and the antinuclear movement. Pollution, environmental disasters, and energy crises during the 1960s and 1970s brought terms like "clean energy" and "renewable energy" into the national lexicon, and solar often served as the most prominent symbol of those ideas. At the same time, advocates presented solar as a stark contrast to nuclear: solar energy made life on earth possible; nuclear energy made it perilous. Science fiction and futurism shaped the American popular imagination through its presentation of solar technology. Each genre suffused the other and ingrained in the American national consciousness a sense of grandiose wonderment about the potential for solar energy, a potential that often did not match the contemporary applications for solar technology. The emergence of solar industries alarmed oil corporations and utilities. Several of these companies embarked on a concerted public misinformation campaign designed to downplay the potential of solar energy, and these actions undermined the development of the nascent solar industries. Solar heating equipment relied on federal stimulus to compete in the market. Yet, federal support for research and development, commercialization, and market facilitation withered under the Reagan administration. Solar occupied a point of convergence for several of Reagan's targets: solar represented Carter, represented big government intervention in the market, and represented environmentalism. Reagan's administration reduced solar funding, redirected and reorganized solar agencies, and repressed solar information. By the early 1980s, Carter's 20% solar goal was dead, and, as a result, the nation's efforts toward developing solar energy were set back decades.
Modélisation à long terme et optimisation du stock d'énergie des installations solaires autonomes
NASA Astrophysics Data System (ADS)
Maafi, A.; Delorme, C.
1996-04-01
A sizing approach of storage capacity for autonomous solar system has been developed by analyzing the difference between solar radiation input and energy demand on long-term periods. This approach has been implemented using series of daily global irradiation data recorded or generated on a horizontal surface in the meteorological stations of Abidjan (Ivory Coast), Algiers and Tamanrasset (Algeria) and Carpentras (France). The obtained results show that for an energy demand equaling the pluriannual mean of solar irradiation a storage of several months is needed to obtain the autonomy of solar systems located in Algiers, Carpentras and Tamanrasset. It should be too expensive investment to set-up such solar systems in these locations. Therefore, the size of the storage is minimized by using a non-zero initial energy storage and reducing the energy demand. This procedure show that it is possible to provide every day a programmed energy using autonomous solar systems which are competitive economically. Une approche de dimensionnement de la capacité de stockage des installations solaires autonomes a été développé. Elle est basée sur l'analyse de la différence entre l'énergie incidente et la consommation requise. Cette méthode a été mise au point à partir de données journalières d'irradiation globale enregistrées ou reconstituées sur plan horizontal dans les stations météorologiques d'Abidjan (Côte d'Ivoire), d'Alger et de Tamanrasset (Algérie) et de Carpentras (France). Pour une demande énergétique correspondant à la production moyenne pluriannuelle d'énergie solaire, les résultats montrent qu'un stockage de plusieurs mois est requis pour garantir l'autonomie de fonctionnement des installations solaires implantées à Alger, Carpentras et Tamanrasset. L'autonomie ainsi obtenue n'est pas économiquement rentable. Aussi, la taille du stockage a été minimisée en utilisant un stock initial d'énergie au démarrage de l'installation et en réduisant la consommation. Ceci a permis de montrer que la couverture de besoins énergétiques planifiés à l'aide d'installations solaires autonomes, compétitives sur le plan économique, est possible.
NASA Technical Reports Server (NTRS)
Ralph, E. L.; Linder, E. B.
1995-01-01
Solar panel designs that utilize new high-efficiency solar cells and lightweight rigid panel technologies are described. The resulting designs increase the specific power (W/kg) achievable in the near-term and are well suited to meet the demands of higher performance small satellites (smallsats). Advanced solar panel designs have been developed and demonstrated on two NASA SBIR contracts at Applied Solar. The first used 19% efficient, large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells with a lightweight rigid graphite epoxy isogrid substrate configuration. A 1,445 sq cm coupon was fabricated and tested to demonstrate 60 W/kg with a high potential of achieving 80 W/kg. The second panel design used new 22% efficiency, dual-junction GaInP2/GaAs/Ge solar cells combined with a lightweight aluminum core/graphite fiber mesh facesheet substrate. A 1,445 sq cm coupon was fabricated and tested to demonstrate 105 W/kg with the potential of achieving 115 W/kg.
Kolpak, Alexie M; Grossman, Jeffrey C
2013-01-21
Challenges with cost, cyclability, and/or low energy density have largely prevented the development of solar thermal fuels, a potentially attractive alternative energy technology based on molecules that can capture and store solar energy as latent heat in a closed cycle. In this paper, we present a set of novel hybrid photoisomer/template solar thermal fuels that can potentially circumvent these challenges. Using first-principles computations, we demonstrate that these fuels, composed of organic photoisomers bound to inexpensive carbon-based templates, can reversibly store solar energy at densities comparable to Li-ion batteries. Furthermore, we show that variation of the template material in combination with the photoisomer can be used to optimize many of the key performance metrics of the fuel-i.e., the energy density, the storage lifetime, the temperature of the output heat, and the efficiency of the solar-to-heat conversion. Our work suggests that the solar thermal fuels concept can be translated into a practical and highly customizable energy storage and conversion technology.
SU-E-T-215: Interactive Dose Shaping: Proof of Concept Study for Six Prostate Patients
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kamerling, CP; German Cancer Research Center; Ziegenhein, P
Purpose: To provide a proof of concept study for IMRT treatment planning through interactive dose shaping (IDS) by utilising the respective tools to create IMRT treatment plans for six prostate patients. Methods: The IDS planning paradigm aims to perform interactive local dose adaptations of an IMRT plan without compromising already established valuable dose features in real-time. Various IDS tools are available in our in-house treatment planning software Dynaplan and were utilised to create IMRT treatment plans for six patients with an adeno-carcinoma of the prostate. The sequenced IDS treatment plans were compared to conventionally optimised clinically approved plans (9 beams,more » co-planar). The starting point consisted of open fields. The IDS tools were utilised to sculpt dose out of the rectum and bladder. For each patient, several IDS plans were created, with different trade-offs between organ sparing and target coverage. The reference dose distributions were imported into Dynaplan. For each patient, the IDS treatment plan with a similar or better trade-off between target coverage and OAR sparing was selected for plan evaluation, guided by a physician. Pencil beam dose calculation was performed on a grid with a voxel size of 1.95×1.95×2.0 mm{sup 3}. D98%, D2%, mean dose and dose-volume indicators as specified by Quantec were calculated for plan evaluation. Results: It was possible to utilise the software prototype to generate treatment plans for prostate patient geometries in 15–45 minutes. Individual local dose adaptations could be performed in less than one second. The average differences compared to the reference plans were for the mean dose: 0.0 Gy (boost) and 1.2 Gy (CTV), for D98%: −1.1 Gy and for D2%: 1.1 Gy (both target volumes). The dose-volume quality indicators were well below the Quantec constraints. Conclusion: Real-time treatment planning utilising IDS is feasible and has the potential to be implemented clinically. Research at The Institute of Cancer Research is supported by Cancer Research UK under Programme C46/A10588.« less
A Groundwater Model to Assess Water Resource Impacts at the Brenda Solar Energy Zone
DOE Office of Scientific and Technical Information (OSTI.GOV)
Quinn, John; Carr, Adrianne E.; Greer, Chris
2013-12-01
The purpose of this study is to develop a groundwater flow model to examine the influence of potential groundwater withdrawal to support utility-scale solar energy development at the Brenda Solar Energy Zone (SEZ), as a part of the Bureau of Land Management’s (BLM’s) Solar Energy Program.
Solar Energy Directory: A Directory of Domestic and International Firms Involved in Solar Energy.
ERIC Educational Resources Information Center
Centerline Co., Phoenix, AZ.
This directory is intended to provide a link between suppliers of solar energy technology and information and potential users of these products. Included are over 1400 national and international entries. These listings include architects, associations, education sources, wind power technology and information sources, solar research organizations,…
Ssalmon - The Solar Simulations For The Atacama Large Millimeter Observatory Network
NASA Astrophysics Data System (ADS)
Wedemeyer, Sven; Ssalmon Group
2016-07-01
The Atacama Large Millimeter/submillimeter Array (ALMA) provides a new powerful tool for observing the solar chromosphere at high spatial, temporal, and spectral resolution, which will allow for addressing a wide range of scientific topics in solar physics. Numerical simulations of the solar atmosphere and modeling of instrumental effects are valuable tools for constraining, preparing and optimizing future observations with ALMA and for interpreting the results. In order to co-ordinate related activities, the Solar Simulations for the Atacama Large Millimeter Observatory Network (SSALMON) was initiated on September 1st, 2014, in connection with the NA- and EU-led solar ALMA development studies. As of April, 2015, SSALMON has grown to 83 members from 18 countries (plus ESO and ESA). Another important goal of SSALMON is to promote the scientific potential of solar science with ALMA, which has resulted in two major publications so far. During 2015, the SSALMON Expert Teams produced a White Paper with potential science cases for Cycle 4, which will be the first time regular solar observations will be carried out. Registration and more information at http://www.ssalmon.uio.no.
Price and utilisation differences for statins between four countries.
Thai, Loc Phuoc; Vitry, Agnes Isabelle; Moss, John Robert
2018-02-01
Australia, England, France and New Zealand use different policies to regulate their medicines market, which can impact on utilisation and price. To compare the prices and utilisation of statins in Australia, England, France and New Zealand from 2011 to 2013. Utilisation of statins in the four countries was compared using Defined Daily Doses (DDD) per 1000 inhabitants per year. Pairwise Laspeyres and Paasche index comparisons were conducted comparing the price and utilisation of statins. The results showed that the price of statins in New Zealand was the cheapest. The price of statins in Australia was most expensive in 2011 and 2012 but France was more expensive in 2013. There were large differences between the Laspeyres index and Paasche index when comparing the price and utilisation of England with Australia and France. The policies that regulate the New Zealand and England medicines markets were more effective in reducing the price of expensive statins. The relative utilisation of cheaper statins was greatest in England and had a large effect on the differences between the two index results. The pricing policies in Australia have been only partly effective in reducing the price of statins compared to other countries.
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
This presentation provides a high-level overview of the current U.S. shared solar landscape, the impact that a given shared solar program's structure has on requiring federal securities oversight, as well as an estimate of market potential for U.S. shared solar deployment.
DIY Solar Market Analysis STAT Webinars | State, Local, and Tribal
do they help policymakers? Solar Resource and Technical Potential: Finding, using, and making maps for decision makers PVWatts: New tips and tricks for the latest update Community Solar Scenario Tool
Spectral mismatch and solar simulator quality factor in advanced LED solar simulators
NASA Astrophysics Data System (ADS)
Scherff, Maximilian L. D.; Nutter, Jason; Fuss-Kailuweit, Peter; Suthues, Jörn; Brammer, Torsten
2017-08-01
Solar cell simulators based on light emitting diodes (LED) have the potential to achieve a large potential market share in the next years. As advantages they can provide a short and long time stable spectrum, which fits very well to the global AM1.5g reference spectrum. This guarantees correct measurements during the flashes and throughout the light engines’ life span, respectively. Furthermore, a calibration with a solar cell type of different spectral response (SR) as well as the production of solar cells with varying SR in between two calibrations does not affect the correctness of the measurement result. A high quality 21 channel LED solar cell spectrum is compared to former study comprising a standard modified xenon spectrum light source. It is shown, that the spectrum of the 21-channel-LED light source performs best for all examined cases.
Quantum-Dot-Based Solar Cells: Recent Advances, Strategies, and Challenges.
Kim, Mee Rahn; Ma, Dongling
2015-01-02
Among next-generation photovoltaic systems requiring low cost and high efficiency, quantum dot (QD)-based solar cells stand out as a very promising candidate because of the unique and versatile characteristics of QDs. The past decade has already seen rapid conceptual and technological advances on various aspects of QD solar cells, and diverse opportunities, which QDs can offer, predict that there is still ample room for further development and breakthroughs. In this Perspective, we first review the attractive advantages of QDs, such as size-tunable band gaps and multiple exciton generation (MEG), beneficial to solar cell applications. We then analyze major strategies, which have been extensively explored and have largely contributed to the most recent and significant achievements in QD solar cells. Finally, their high potential and challenges are discussed. In particular, QD solar cells are considered to hold immense potential to overcome the theoretical efficiency limit of 31% for single-junction cells.
Fang, Jia; Liu, Bofei; Zhao, Ying; Zhang, Xiaodan
2014-08-22
Introducing light trapping structures into thin-film solar cells has the potential to enhance their solar energy harvesting as well as the performance of the cells; however, current strategies have been focused mainly on harvesting photons without considering the light re-escaping from cells in two-dimensional scales. The lateral out-coupled solar energy loss from the marginal areas of cells has reduced the electrical yield indeed. We therefore herein propose a lateral light trapping structure (LLTS) as a means of improving the light-harvesting capacity and performance of cells, achieving a 13.07% initial efficiency and greatly improved current output of a-Si:H single-junction solar cell based on this architecture. Given the unique transparency characteristics of thin-film solar cells, this proposed architecture has great potential for integration into the windows of buildings, microelectronics and other applications requiring transparent components.
NASA Technical Reports Server (NTRS)
Rapp, D.
1981-01-01
The book opens with a review of the patterns of energy use and resources in the United States, and an exploration of the potential of solar energy to supply some of this energy in the future. This is followed by background material on solar geometry, solar intensities, flat plate collectors, and economics. Detailed attention is then given to a variety of solar units and systems, including domestic hot water systems, space heating systems, solar-assisted heat pumps, intermediate temperature collectors, space heating/cooling systems, concentrating collectors for high temperatures, storage systems, and solar total energy systems. Finally, rights to solar access are discussed.
India Solar Resource Data: Enhanced Data for Accelerated Deployment (Fact Sheet)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
Identifying potential locations for solar photovoltaic (PV) and concentrating solar power (CSP) projects requires an understanding of the underlying solar resource. Under a bilateral partnership between the United States and India - the U.S.-India Energy Dialogue - the National Renewable Energy Laboratory has updated Indian solar data and maps using data provided by the Ministry of New and Renewable Energy (MNRE) and the National Institute for Solar Energy (NISE). This fact sheet overviews the updated maps and data, which help identify high-quality solar energy projects. This can help accelerate the deployment of solar energy in India.
India Solar Resource Data: Enhanced Data for Accelerated Deployment
DOE Office of Scientific and Technical Information (OSTI.GOV)
None, None
Identifying potential locations for solar photovoltaic (PV) and concentrating solar power (CSP) projects requires an understanding of the underlying solar resource. Under a bilateral partnership between the United States and India - the U.S.-India Energy Dialogue - the National Renewable Energy Laboratory has updated Indian solar data and maps using data provided by the Ministry of New and Renewable Energy (MNRE) and the National Institute for Solar Energy (NISE). This fact sheet overviews the updated maps and data, which help identify high-quality solar energy projects. This can help accelerate the deployment of solar energy in India.
Optically Transparent Thermally Insulating Silica Aerogels for Solar Thermal Insulation.
Günay, A Alperen; Kim, Hannah; Nagarajan, Naveen; Lopez, Mateusz; Kantharaj, Rajath; Alsaati, Albraa; Marconnet, Amy; Lenert, Andrej; Miljkovic, Nenad
2018-04-18
Rooftop solar thermal collectors have the potential to meet residential heating demands if deployed efficiently at low solar irradiance (i.e., 1 sun). The efficiency of solar thermal collectors depends on their ability to absorb incoming solar energy and minimize thermal losses. Most techniques utilize a vacuum gap between the solar absorber and the surroundings to eliminate conduction and convection losses, in combination with surface coatings to minimize reradiation losses. Here, we present an alternative approach that operates at atmospheric pressure with simple, black, absorbing surfaces. Silica based aerogels coated on black surfaces have the potential to act as simple and inexpensive solar thermal collectors because of their high transmission to solar radiation and low transmission to thermal radiation. To demonstrate their heat-trapping properties, we fabricated tetramethyl orthosilicate-based silica aerogels. A hydrophilic aerogel with a thickness of 1 cm exhibited a solar-averaged transmission of 76% and thermally averaged transmission of ≈1% (at 100 °C). To minimize unwanted solar absorption by O-H groups, we functionalized the aerogel to be hydrophobic, resulting in a solar-averaged transmission of 88%. To provide a deeper understanding of the link between aerogel properties and overall efficiency, we developed a coupled radiative-conductive heat transfer model and used it to predict solar thermal performance. Instantaneous solar thermal efficiencies approaching 55% at 1 sun and 80 °C were predicted. This study sheds light on the applicability of silica aerogels on black coatings for solar thermal collectors and offers design priorities for next-generation solar thermal aerogels.
Solar energy in buildings: Implications for California energy policy
NASA Technical Reports Server (NTRS)
Hirshberg, A. S.; Davis, E. S.
1977-01-01
An assessment of the potential of active solar energy systems for buildings in California is summarized. The technology used for solar heating, cooling, and water heating in buildings is discussed. The major California weather zones and the solar energy designs are described, as well as the sizing of solar energy systems and their performance. The cost of solar energy systems is given both at current prices and at prices consistent with optimistic estimates for the cost of collectors. The main institutional barriers to the wide spread use of solar energy are summarized.
NASA Technical Reports Server (NTRS)
Barbieri, R. H.; Bartera, R. E.; Davis, E. S.; Hlavka, G. E.; Pivirotto, D. S.; Yanow, G.
1978-01-01
A summary of the results of a survey of potential applications of solar energy for supplying process heat requirements in the industrial, agricultural, and commercial sectors of California is presented. Technical, economic, and institutional characteristics of the three sectors are examined. Specific applications for solar energy are then discussed. Finally, implications for California energy policy are discussed along with recommendations for possible actions by the State of California.
Requirements for transportation of fast pyrolysis bio-oil in Finland
NASA Astrophysics Data System (ADS)
Karhunen, Antti; Laihanen, Mika; Ranta, Tapio
2016-11-01
The purpose of this paper is to discuss the requirements and challenges of pyrolysis oil's transportation in Finland. Pyrolysis oil is a new type of renewable liquid fuel that can be utilised in applications such as heat and electricity production. It has never been transported on a large scale in Finland. Possible options are transport by road, rail and waterway. The most significant requirements in its transportation are created by acidity and high density of pyrolysis oil, which impose requirements for the materials and transport equipment. The study described here shows that constant domestic transportation of pyrolysis oil is most reasonably operated with tank trucks. Rail-based transport may have potential for domestic fixed routes, and transport by water could be utilised in exporting. All transportation methods have limitations and advantages relative to each other. Ultimately, the production site and end-user's locations will determine the most suitable transport method.
A Business Analytics Software Tool for Monitoring and Predicting Radiology Throughput Performance.
Jones, Stephen; Cournane, Seán; Sheehy, Niall; Hederman, Lucy
2016-12-01
Business analytics (BA) is increasingly being utilised by radiology departments to analyse and present data. It encompasses statistical analysis, forecasting and predictive modelling and is used as an umbrella term for decision support and business intelligence systems. The primary aim of this study was to determine whether utilising BA technologies could contribute towards improved decision support and resource management within radiology departments. A set of information technology requirements were identified with key stakeholders, and a prototype BA software tool was designed, developed and implemented. A qualitative evaluation of the tool was carried out through a series of semi-structured interviews with key stakeholders. Feedback was collated, and emergent themes were identified. The results indicated that BA software applications can provide visibility of radiology performance data across all time horizons. The study demonstrated that the tool could potentially assist with improving operational efficiencies and management of radiology resources.
Hone, Thomas; Lee, John Tayu; Majeed, Azeem; Conteh, Lesong; Millett, Christopher
2017-06-01
Policy-makers are increasingly considering charging users different fees between primary and secondary care (differential user charges) to encourage utilisation of primary health care in health systems with limited gate keeping. A systematic review was conducted to evaluate the impact of introducing differential user charges on service utilisation. We reviewed studies published in MEDLINE, EMBASE, the Cochrane library, EconLIT, HMIC, and WHO library databases from January 1990 until June 2015. We extracted data from the studies meeting defined eligibility criteria and assessed study quality using an established checklist. We synthesized evidence narratively. Eight studies from six countries met our eligibility criteria. The overall study quality was low, with diversity in populations, interventions, settings, and methods. Five studies examined the introduction of or increase in user charges for secondary care, with four showing decreased secondary care utilisation, and three showing increased primary care utilisation. One study identified an increase in primary care utilisation after primary care user charges were reduced. The introduction of a non-referral charge in secondary care was associated with lower primary care utilisation in one study. One study compared user charges across insurance plans, associating higher charges in secondary care with higher utilisation in both primary and secondary care. Overall, the impact of introducing differential user-charges on primary care utilisation remains uncertain. Further research is required to understand their impact as a demand side intervention, including implications for health system costs and on utilisation among low-income patients. © The Author 2017. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Ndabarora, Eléazar; Mchunu, Gugu
2014-01-01
Various studies have reported that university students, who are mostly young people, rarely use existing HIV/AIDS preventive methods. Although studies have shown that young university students have a high degree of knowledge about HIV/AIDS and HIV modes of transmission, they are still not utilising the existing HIV prevention methods and still engage in risky sexual practices favourable to HIV. Some variables, such as awareness of existing HIV/AIDS prevention methods, have been associated with utilisation of such methods. The study aimed to explore factors that influence use of existing HIV/AIDS prevention methods among university students residing in a selected campus, using the Health Belief Model (HBM) as a theoretical framework. A quantitative research approach and an exploratory-descriptive design were used to describe perceived factors that influence utilisation by university students of HIV/AIDS prevention methods. A total of 335 students completed online and manual questionnaires. Study findings showed that the factors which influenced utilisation of HIV/AIDS prevention methods were mainly determined by awareness of the existing university-based HIV/AIDS prevention strategies. Most utilised prevention methods were voluntary counselling and testing services and free condoms. Perceived susceptibility and perceived threat of HIV/AIDS score was also found to correlate with HIV risk index score. Perceived susceptibility and perceived threat of HIV/AIDS showed correlation with self-efficacy on condoms and their utilisation. Most HBM variables were not predictors of utilisation of HIV/AIDS prevention methods among students. Intervention aiming to improve the utilisation of HIV/AIDS prevention methods among students at the selected university should focus on removing identified barriers, promoting HIV/AIDS prevention services and providing appropriate resources to implement such programmes.
Solar Variability in the Context of Other Climate Forcing Mechanisms
NASA Technical Reports Server (NTRS)
Hansen, James E.
1999-01-01
I compare and contrast climate forcings due to solar variability with climate forcings due to other mechanisms of climate change, interpretation of the role of the sun in climate change depends upon climate sensitivity and upon the net forcing by other climate change mechanisms. Among the potential indirect climate forcings due to solar variability, only that due to solar cycle induced ozone changes has been well quantified. There is evidence that the sun has been a significant player in past climate change on decadal to century time scales, and that it has the potential to contribute to climate change in the 21st century.
ERIC Educational Resources Information Center
Hall, Richard
2015-01-01
Ensemble work is a key part of any performance-based popular music course and involves students replicating existing music or playing "covers". The creative process in popular music is a collaborative one and the ensemble workshop can be utilised to facilitate active learning and develop musical creativity within a group setting. This is…
Humphrey Davy and the Safety Lamp: The Use of Metal Gauze as a Flame Barrier
ERIC Educational Resources Information Center
Mills, Allan
2015-01-01
The "safety lamp" invented by Humphrey Davy in 1815 utilised the cooling effect of metal gauze to prevent the flame of a candle or oil lamp (essential for illumination in mines) from passing through such a screen. It is therefore rendered unable to ignite any potentially explosive mixture of air and methane in the atmosphere surrounding…
Evaluation of eLearning Usage in South African Universities: A Critical Review
ERIC Educational Resources Information Center
Bagarukayo, Emily; Kalema, Billy
2015-01-01
Although eLearning is the use of technology for teaching, learning and assessment, there is no common approach to it across South African Higher Education Institutions. There is therefore a concern that the full potential of eLearning approach is not utilised. This paper examines the nature and the extent of eLearning activities in South African…
Utilising a Virtual World to Teach Performance Appraisal: An Exploratory Study
ERIC Educational Resources Information Center
Morse, Shona
2010-01-01
Purpose: The aim of this paper is to give a critical assessment of a study designed to investigate the potential of a new method for teaching HRD students about performance appraisal. It is argued that this approach is in the vanguard of developments in IT and learning. Design/methodology/approach: The paper takes the form of an explorative study…
ERIC Educational Resources Information Center
McGillivray, J. A.; Evert, H. T.
2014-01-01
We examined the efficacy of cognitive behavioural therapy (CBT) delivered in groups on the reduction of symptoms of depression, anxiety and stress in young people on the autism spectrum. Utilising a quasi-experimental design, comparisons were made between individuals allocated to a group intervention program and individuals allocated to a…
ERIC Educational Resources Information Center
Buaraphan, Khajornsak
2011-01-01
Beliefs are psychological constructs potentially driving a teacher to make pedagogical decisions and act. In this study, the metaphor construction task (MCT) was utilised to uncover beliefs about teaching and learning science held by 110 pre-service science teachers participating in the standard-based teacher preparation programme. Overall, the…
ERIC Educational Resources Information Center
Mawson, William Brent
2014-01-01
Outdoor play environments offer a wide range of potential affordances to both teachers and children. Teachers' pedagogy is a strong determining factor in children's ability to utilise the affordances of a particular environment. This article describes the way in which a group of teachers and children in a New Zealand education and care centre…
Assessment of Rooftop Area in Austin Energy's Service Territory Suitable for PV Development
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wiese, Steven M.
The objective of this project was to create a model for assessing the amount of rooftop area on commercial, industrial, institutional, and governmental buildings in Austin Energy's service area suitable for solar electric energy development and, based on this model, determine the potential installed capacity and annual energy production from solar electric installations on the rooftops of these buildings. Key questions addressed by this project were: 1.What is the aggregate rooftop area, rooftop area suitable for PV project development, and potential for PV capacity and energy production from rooftop solar photovoltaic systems on key building types in Austin Energy's servicemore » area? 2.How do the potential capacity and annual energy production from rooftop solar electric systems compare with Austin Energy's current capacity and annual energy requirements?« less
NASA Technical Reports Server (NTRS)
Ferguson, Dale C.; Hillard, G. Barry
1994-01-01
SAMPIE, the Solar Array Module Plasma Interactions Experiment, flew in the Space Shuttle Columbia payload bay as part of the OAST-2 mission on STS-62, March, 1994. SAMPIE biased samples of solar arrays and space power materials to varying potentials with respect to the surrounding space plasma, and recorded the plasma currents collected and the arcs which occurred, along with a set of plasma diagnostics data. A large set of high quality data was obtained on the behavior of solar arrays and space power materials in the space environment. This paper is the first report on the data SAMPIE telemetered to the ground during the mission. It will be seen that the flight data promise to help determine arcing thresholds, snapover potentials and floating potentials for arrays and spacecraft in LEO.
SWOT analysis of the renewable energy sources in Romania - case study: solar energy
NASA Astrophysics Data System (ADS)
Lupu, A. G.; Dumencu, A.; Atanasiu, M. V.; Panaite, C. E.; Dumitrașcu, Gh; Popescu, A.
2016-08-01
The evolution of energy sector worldwide triggered intense preoccupation on both finding alternative renewable energy sources and environmental issues. Romania is considered to have technological potential and geographical location suitable to renewable energy usage for electricity generation. But this high potential is not fully exploited in the context of policies and regulations adopted globally, and more specific, European Union (EU) environmental and energy strategies and legislation related to renewable energy sources. This SWOT analysis of solar energy source presents the state of the art, potential and future prospects for development of renewable energy in Romania. The analysis concluded that the development of solar energy sector in Romania depends largely on: viability of legislative framework on renewable energy sources, increased subsidies for solar R&D, simplified methodology of green certificates, and educating the public, investors, developers and decision-makers.
Solar energy research and utilization
NASA Technical Reports Server (NTRS)
Cherry, W. R.
1974-01-01
The role of solar energy is visualized in the heating and cooling of buildings, in the production of renewable gaseous, liquid and solid fuels, and in the production of electric power over the next 45 years. Potential impacts of solar energy on various energy markets, and estimated costs of such solar energy systems are discussed. Some typical solar energy utilization processes are described in detail. It is expected that at least 20% of the U.S. total energy requirements by 2020 will be delivered from solar energy.
Guidebook for solar process-heat applications
NASA Astrophysics Data System (ADS)
Fazzolare, R.; Mignon, G.; Campoy, L.; Luttmann, F.
1981-01-01
The potential for solar process heat in Arizona and some of the general technical aspects of solar, such as insolation, siting, and process analysis are explored. Major aspects of a solar plant design are presented. Collectors, storage, and heat exchange are discussed. Reducing hardware costs to annual dollar benefits is also discussed. Rate of return, cash flow, and payback are discussed as they relate to solar systems. Design analysis procedures are presented. The design cost optimization techniques using a yearly computer simulation of a solar process operation is demonstrated.
Rock Smelting of Copper Ores with Waste Heat Recovery
NASA Astrophysics Data System (ADS)
Norgate, Terry; Jahanshahi, Sharif; Haque, Nawshad
It is generally recognised that the grades of metallic ores are falling globally. This trend can be expected to increase the life cycle-based energy requirement for primary metal production due to the additional amount of material that must be handled and treated in the mining and mineral processing stages of the metal production life cycle. Rock (or whole ore) smelting has been suggested as a possible alternative processing route for low grade ores with a potentially lower energy intensity and environmental impact than traditional processing routes. In this processing route, the beneficiation stage is eliminated along with its associated energy consumption and greenhouse gas emissions, but this is partially offset by the need for more solid material to be handled and heated up to smelting temperatures. A life cycle assessment study was carried out to assess the potential energy and greenhouse gas benefits of a conceptual flowsheet of the rock smelting process, using copper ore as an example. Recovery and utilisation of waste heat in the slag (via dry slag granulation) and offgas streams from the smelting step was also included in the study, with the waste heat being utilised either for thermal applications or electricity generation.
Possibilities and limitations of wind energy utilisation
NASA Astrophysics Data System (ADS)
Feustel, J.
1981-10-01
The existing wind resource, the most favorable locations, applications, and designs of windpowered generators are reviewed, along with descriptions of current and historic wind turbines and lines of research. Coastal regions, plains, hill summits, and mountains with funneling regions are noted to have the highest annual wind averages, with energy densities exceeding the annual solar insolation at average wind speeds of 5-7.9 m/sec. Applications for utility-grade power production, for irrigation, for mechanical heat production, and for pumped storage in water towers or reservoirs are mentioned, as well as electrical power production in remote areas and for hydrogen production by electrolysis. Power coefficients are discussed, with attention given to the German Growian 3 MW machine. It is shown that the least economically sound wind turbines, the machines with outputs below 100 kW, can vie with diesel plant economics in a good wind regime if the wind turbine operates for 15 yr.
Study of a two-bed silica gel-water adsorption chiller: performance analysis
NASA Astrophysics Data System (ADS)
Sah, Ramesh P.; Choudhury, Biplab; Das, Ranadip K.
2018-01-01
In this study, a lumped parameter simulation model has been developed for analysis of the thermal performance of a single-stage two-bed adsorption chiller. Since silica gel has low regeneration temperature and water has high latent heat of vaporisation, silica gel-water pair has been chosen as the working pair of the adsorption chiller. Low-grade waste heat or solar heat at around 70-80°C can be used to run this adsorption chiller. In this model, the effects of operating parameters on the performance of the chiller have been studied. The simulated results show that the cooling capacity of the chiller has an optimum value of 5.95 kW for a cycle time of 1600 s with the hot, cooling, and chilled water inlet temperatures at 85°C, 25°C, and 14°C, respectively. The present model can be utilised to investigate and optimise adsorption chillers.
Exploration of the solar system
NASA Technical Reports Server (NTRS)
Henderson, A., Jr.; Grey, J.
1974-01-01
A sourcebook of information on the solar system and the technology used for its exploration is presented. An outline of the potential achievements of solar system exploration is given along with a course of action which maximizes the rewards to mankind.
Distribution Strategies for Solar and Wind Renewables in NW Europe
NASA Astrophysics Data System (ADS)
Smedley, Andrew; Webb, Ann
2017-04-01
Whilst the UNFCCC Paris Agreement Climate change was ratified in November, 2016 saw the highest global temperature anomaly on record at 1.2°C above pre-industrial levels. As such there is urgent need to reduce CO2 emissions by a move away from fossil fuels and towards renewable electricity energy technologies. As the principal renewable technologies of solar PV and wind turbines contribute an increasing fraction to the electricity grid, questions of cumulative intermittency and the large-scale geographic distribution of each technology need to be addressed. In this study our initial emphasis is on a calculation of a relatively high spatial resolution (0.1° × 0.1°) daily gridded dataset of solar irradiance data, over a 10 year period (2006-2015). This is achieved by coupling established sources of satellite data (MODIS SSF level2 instantaneous footprint data) to a well-validated radiative transfer model, here LibRadTran. We utilise both a morning and afternoon field for two cloud layers (optical depth and cloud fraction) interpolated to hourly grids, together with aerosol optical depth, topographic height and solar zenith angle. These input parameters are passed to a 5-D LUT of LibRadTran results to construct hourly estimates of the solar irradiance field, which is then integrated to a daily total. For the daily wind resource we rely on the 6 hourly height-adjusted ECMWF ERA-Interim reanalysis wind fields, but separated into onshore, offshore and deep water components. From these datasets of the solar and wind resources we construct 22 different distribution strategies for solar PV and wind turbines based on the long-term availability of each resource. Combining these distributions with the original daily gridded datasets enables each distribution strategy to be then assessed in terms of the day-to-day variability, the installed capacity required to maintain a baseline supply, and the relative proportions of each technology. Notably for the NW European area considered we find that distribution strategies that only deploy renewables in regions with the highest annual mean irradiance or wind resource, also minimise the total required installed capacity and typically exhibit the smallest output range. Further in the majority of strategies we find that the onshore and offshore wind resource fractions fall to zero with the wind contribution being fully composed of deep water installations. Only as the strategy is to increasingly concentrate each technology in areas with the highest annual mean resource do firstly offshore, and then onshore wind, contribute.
Utilization of solar energy in developing countries: Identifying some potential markets
NASA Technical Reports Server (NTRS)
Hein, G. F.; Siddiqi, T. A.
1978-01-01
The potential use of solar electricity generated from photovoltaic cells is examined for nineteen developing nations. Energy and economic profiles are summarized for each country. A comparison is made between the use of autogeneration and photovoltaics in a rural area of Haiti.
NASA Astrophysics Data System (ADS)
Grippo, Mark; Hayse, John W.; O'Connor, Ben L.
2015-01-01
The cumulative impacts of utility-scale solar energy facilities on aquatic ecosystems in the Southwestern United States are of concern, considering the many existing regional anthropogenic stressors. We review the potential impacts of solar energy development on aquatic habitat and biota. The greatest potential for impacts is related to the loss, fragmentation, or prolonged drying of ephemeral water bodies and drainage networks resulting from the loss of desert washes within the construction footprint of the facility. Groundwater-dependent aquatic habitat may also be affected by operational groundwater withdrawal in the case of water-intensive solar technologies. Solar panels have also been found to attract aquatic insects and waterbirds, potentially resulting in mortality. Avoiding construction activity near perennial and intermittent surface waters is the primary means of reducing impacts on aquatic habitats, followed by measures to minimize erosion, sedimentation, and contaminant inputs into waterways. Currently, significant data gaps make solar facility impact assessment and mitigation more difficult. Examples include the need for more regional and site-specific studies of surface-groundwater connectivity, more detailed maps of regional stream networks and riparian vegetation corridors, as well as surveys of the aquatic communities inhabiting ephemeral streams. In addition, because they often lack regulatory protection, there is also a need to develop valuation criteria for ephemeral waters based on their ecological and hydrologic function within the landscape. By addressing these research needs, we can achieve the goal of greater reliance on solar energy, while at the same time minimizing impacts on desert ecosystems.
Grippo, Mark; Hayse, John W; O'Connor, Ben L
2015-01-01
The cumulative impacts of utility-scale solar energy facilities on aquatic ecosystems in the Southwestern United States are of concern, considering the many existing regional anthropogenic stressors. We review the potential impacts of solar energy development on aquatic habitat and biota. The greatest potential for impacts is related to the loss, fragmentation, or prolonged drying of ephemeral water bodies and drainage networks resulting from the loss of desert washes within the construction footprint of the facility. Groundwater-dependent aquatic habitat may also be affected by operational groundwater withdrawal in the case of water-intensive solar technologies. Solar panels have also been found to attract aquatic insects and waterbirds, potentially resulting in mortality. Avoiding construction activity near perennial and intermittent surface waters is the primary means of reducing impacts on aquatic habitats, followed by measures to minimize erosion, sedimentation, and contaminant inputs into waterways. Currently, significant data gaps make solar facility impact assessment and mitigation more difficult. Examples include the need for more regional and site-specific studies of surface-groundwater connectivity, more detailed maps of regional stream networks and riparian vegetation corridors, as well as surveys of the aquatic communities inhabiting ephemeral streams. In addition, because they often lack regulatory protection, there is also a need to develop valuation criteria for ephemeral waters based on their ecological and hydrologic function within the landscape. By addressing these research needs, we can achieve the goal of greater reliance on solar energy, while at the same time minimizing impacts on desert ecosystems.
Life cycle assessment of construction and demolition waste management
DOE Office of Scientific and Technical Information (OSTI.GOV)
Butera, Stefania, E-mail: stbu@teknologisk.dk; Christensen, Thomas H.; Astrup, Thomas F.
Highlights: • LCA of C&DW utilisation in road vs. C&DW landfilling. • C&DW utilisation in road better than landfilling for most categories. • Transportation is the most important process in non-toxic impact categories. • Leaching of oxyanions is the critical process in toxic impact categories. • Modelling of Cr fate in the subsoil is highly influential to the results. - Abstract: Life cycle assessment (LCA) modelling of construction and demolition waste (C&DW) management was carried out. The functional unit was management of 1 Mg mineral, source separated C&DW, which is either utilised in road construction as a substitute for naturalmore » aggregates, or landfilled. The assessed environmental impacts included both non-toxic and toxic impact categories. The scenarios comprised all stages of the end-of-life management of C&DW, until final disposal of all residues. Leaching of inorganic contaminants was included, as was the production of natural aggregates, which was avoided because of the use of C&DW. Typical uncertainties related to contaminant leaching were addressed. For most impact categories, utilisation of C&DW in road construction was preferable to landfilling; however, for most categories, utilisation resulted in net environmental burdens. Transportation represented the most important contribution for most nontoxic impacts, accounting for 60–95 per cent of these impacts. Capital goods contributed with negligible impacts. Leaching played a critical role for the toxic categories, where landfilling had lower impacts than utilisation because of the lower levels of leachate per ton of C&DW reaching the groundwater over a 100-year perspective. Leaching of oxyanions (As, V and Sb) was critical with respect to leaching. Typical experimental uncertainties in leaching data did not have a pivotal influence on the results; however, accounting for Cr immobilisation in soils as part of the impact assessment was critical for modelling the leaching impacts. Compared with the overall life cycle of building and construction materials, leaching emissions were shown to be potentially significant for toxicity impacts, compared with contributions from production of the same materials, showing that end-of-life impacts and leaching should not be disregarded when assessing environmental impacts from construction products and materials. CO{sub 2} uptake in the C&DW corresponding to 15 per cent carbonation could out-balance global warming impacts from transportation; however, carbonation would also likely result in increased toxicity impacts due to higher leaching of oxyanions.« less
Calculating Solar Energy Potential of Buildings and Visualization Within Unity 3d Game Engine
NASA Astrophysics Data System (ADS)
Buyuksalih, G.; Bayburt, S.; Baskaraca, A. P.; Karim, H.; Rahman, A. Abdul
2017-10-01
Solar energy modelling is increasingly popular, important, and economic significant in solving energy crisis for big cities. It is a clean and renewable resource of energy that can be utilized to accommodate individual or group of buildings electrical power as well as for indoor heating. Implementing photovoltaic system (PV) in urban areas is one of the best options to solve power crisis over expansion of urban and the growth of population. However, as the spaces for solar panel installation in cities are getting limited nowadays, the available strategic options are only at the rooftop and façade of the building. Thus, accurate information and selecting building with the highest potential solar energy amount collected is essential in energy planning, environmental conservation, and sustainable development of the city. Estimating the solar energy/radiation from rooftop and facade are indeed having a limitation - the shadows from other neighbouring buildings. The implementation of this solar estimation project for Istanbul uses CityGML LoD2-LoD3. The model and analyses were carried out using Unity 3D Game engine with development of several customized tools and functionalities. The results show the estimation of potential solar energy received for the whole area per day, week, month and year thus decision for installing the solar panel could be made. We strongly believe the Unity game engine platform could be utilized for near future 3D mapping visualization purposes.
Kohno, Ayako; Nik Farid, Nik Daliana; Musa, Ghazali; Abdul Aziz, Norlaili; Nakayama, Takeo; Dahlui, Maznah
2016-03-22
While living overseas in another culture, retirees need to adapt to a new environment but often this causes difficulties, particularly among those elderly who require healthcare services. This study examines factors affecting healthcare service utilisation among Japanese retirees in Malaysia. We conducted 6 focus group discussions with Japanese retirees and interviewed 8 relevant medical services providers in-depth. Guided by the Andersen Healthcare Utilisation Model, we managed and analysed the data, using QSR NVivo 10 software and the directed content analysis method. We interviewed participants at Japan Clubs and their offices. 30 Japanese retirees who live in Kuala Lumpur and Ipoh, and 8 medical services providers. We identified health beliefs, medical symptoms and health insurance as the 3 most important themes, respectively, representing the 3 dimensions within the Andersen Healthcare Utilisation Model. Additionally, language barriers, voluntary health repatriation to Japan and psychological support were unique themes that influence healthcare service utilisation among Japanese retirees. The healthcare service utilisation among Japanese retirees in Malaysia could be partially explained by the Andersen Healthcare Utilisation Model, together with some factors that were unique findings to this study. Healthcare service utilisation among Japanese retirees in Malaysia could be improved by alleviating negative health beliefs through awareness programmes for Japanese retirees about the healthcare systems and cultural aspects of medical care in Malaysia. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
A Groundwater Model to Assess Water Resource Impacts at the Imperial East Solar Energy Zone
DOE Office of Scientific and Technical Information (OSTI.GOV)
Quinn, John; Greer, Chris; O'Connor, Ben L.
2013-12-01
The purpose of this study is to develop a groundwater flow model to examine the influence of potential groundwater withdrawal to support the utility-scale solar energy development at the Imperial East Solar Energy Zone (SEZ) as a part of the Bureau of Land Management’s (BLM) solar energy program.
Amthor, Jeffrey S
2010-12-01
The relationship between solar radiation capture and potential plant growth is of theoretical and practical importance. The key processes constraining the transduction of solar radiation into phyto-energy (i.e. free energy in phytomass) were reviewed to estimate potential solar-energy-use efficiency. Specifically, the out-put:input stoichiometries of photosynthesis and photorespiration in C(3) and C(4) systems, mobilization and translocation of photosynthate, and biosynthesis of major plant biochemical constituents were evaluated. The maintenance requirement, an area of important uncertainty, was also considered. For a hypothetical C(3) grain crop with a full canopy at 30°C and 350 ppm atmospheric [CO(2) ], theoretically potential efficiencies (based on extant plant metabolic reactions and pathways) were estimated at c. 0.041 J J(-1) incident total solar radiation, and c. 0.092 J J(-1) absorbed photosynthetically active radiation (PAR). At 20°C, the calculated potential efficiencies increased to 0.053 and 0.118 J J(-1) (incident total radiation and absorbed PAR, respectively). Estimates for a hypothetical C(4) cereal were c. 0.051 and c. 0.114 J J(-1), respectively. These values, which cannot be considered as precise, are less than some previous estimates, and the reasons for the differences are considered. Field-based data indicate that exceptional crops may attain a significant fraction of potential efficiency. © The Author (2010). Journal compilation © New Phytologist Trust (2010).
An adaptive strategy for active debris removal
NASA Astrophysics Data System (ADS)
White, Adam E.; Lewis, Hugh G.
2014-04-01
Many parameters influence the evolution of the near-Earth debris population, including launch, solar, explosion and mitigation activities, as well as other future uncertainties such as advances in space technology or changes in social and economic drivers that effect the utilisation of space activities. These factors lead to uncertainty in the long-term debris population. This uncertainty makes it difficult to identify potential remediation strategies, involving active debris removal (ADR), that will perform effectively in all possible future cases. Strategies that cannot perform effectively, because of this uncertainty, risk either not achieving their intended purpose, or becoming a hindrance to the efforts of spacecraft manufactures and operators to address the challenges posed by space debris. One method to tackle this uncertainty is to create a strategy that can adapt and respond to the space debris population. This work explores the concept of an adaptive strategy, in terms of the number of objects required to be removed by ADR, to prevent the low Earth orbit (LEO) debris population from growing in size. This was demonstrated by utilising the University of Southampton’s Debris Analysis and Monitoring Architecture to the Geosynchronous Environment (DAMAGE) tool to investigate ADR rates (number of removals per year) that change over time in response to the current space environment, with the requirement of achieving zero growth of the LEO population. DAMAGE was used to generate multiple Monte Carlo projections of the future LEO debris environment. Within each future projection, the debris removal rate was derived at five-year intervals, by a new statistical debris evolutionary model called the Computational Adaptive Strategy to Control Accurately the Debris Environment (CASCADE) model. CASCADE predicted the long-term evolution of the current DAMAGE population with a variety of different ADR rates in order to identify a removal rate that produced a zero net growth for that particular projection after 200 years. The results show that using an adaptive ADR rate generated by CASCADE, alongside good compliance with existing mitigation measures, increases the probability of achieving a constant LEO population of objects greater than 10 cm. This was shown to be 12% greater compared with removing five objects per year, with the additional advantage of requiring only 3.1 removals per year, on average.
NASA Astrophysics Data System (ADS)
Ehrenfreund, Pascale; Foing, Bernard
2014-05-01
In response to the growing importance of space exploration, the objectives of the COSPAR Panel on Exploration (PEX) are to provide high quality, independent science input to support the development of a global space exploration program while working to safeguard the scientific assets of solar system bodies. PEX engages with COSPAR Commissions and Panels, science foundations, IAA, IAF, UN bodies, and IISL to support in particular national and international space exploration working groups and the new era of planetary exploration. COSPAR's input, as gathered by PEX, is intended to express the consensus view of the international scientific community and should ultimately provide a series of guidelines to support future space exploration activities and cooperative efforts, leading to outstanding scientific discoveries, opportunities for innovation, strategic partnerships, technology progression, and inspiration for people of all ages and cultures worldwide. We shall focus on the lunar exploration aspects, where the COSPAR PEX is building on previous COSPAR, ILEWG and community conferences. An updated COSPAR PEX report is published and available online (Ehrenfreund P. et al, COSPAR planetary exploration panel report, http://www.gwu.edu/~spi/assets/COSPAR_PEX2012.pdf). We celebrate 20 years after the 1st International Conference on Exploration and Utilisation of the Moon at Beatenberg in June 1994. The International Lunar Exploration Working Group (ILEWG) was established the year after in April 1995 at an EGS meeting in Hamburg, Germany. As established in its charter, this working group reports to COSPAR and is charged with developing an international strategy for the exploration of the Moon (http://sci.esa.int/ilewg/ ). It discusses coordination between missions, and a road map for future international lunar exploration and utilisation. It fosters information exchange or potential and real future lunar robotic and human missions, as well as for new scientific and exploration information about the Moon. We present the GLUC/ICEUM11 declaration (with emphasis on Science and exploration; Technologies and resources, Infrastructures and human aspects; Moon, Space, Society and Young Explorers) (http://sci.esa.int/iceum11). We give a report on ongoing relevant ILEWG community activities. We discuss how lunar missions SMART-1, Kaguya, Chang'E1&2, Chandrayaan-1, LCROSS, LRO, GRAIL, LADEE, Chang'E3 and upcoming missions contribute to lunar exploration objectives & roadmap.
Deng, Bowen; Chen, Zhigang; Gao, Muxing; Song, Yuqiao; Zheng, Kaiyuan; Tang, Juanjuan; Xiao, Wei; Mao, Xuhui; Wang, Dihua
2016-08-15
Electrochemical transformation of CO2 into functional materials or fuels (i.e., carbon, CO) in high temperature molten salts has been demonstrated as a promising way of carbon capture, utilisation and storage (CCUS) in recent years. In a view of continuous operation, the electrolysis process should match very well with the CO2 absorption kinetics. At the same time, in consideration of the energy efficiency, a molten salt electrochemical cell running at lower temperature is more beneficial to a process powered by the fluctuating renewable electricity from solar/wind farms. Ternary carbonates (Li : Na : K = 43.5 : 31.5 : 25.0) and binary chlorides (Li : K = 58.5 : 41.5), two typical kinds of eutectic melt with low melting points and a wide electrochemical potential window, could be the ideal supporting electrolyte for the molten salt CO2 capture and electro-transformation (MSCC-ET) process. In this work, the CO2 absorption behaviour in Li2O/CaO containing carbonates and chlorides were investigated on a home-made gas absorption testing system. The electrode processes as well as the morphology and properties of carbon obtained in different salts are compared to each other. It was found that the composition of molten salts significantly affects the absorption of CO2, electrode processes and performance of the product. Furthermore, the relationship between the absorption and electro-transformation kinetics are discussed based on the findings.
Introduction to solar heating and cooling design and sizing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
This manual is designed to introduce the practical aspects of solar heating/cooling systems to HVAC contractors, architects, engineers, and other interested individuals. It is intended to enable readers to assess potential solar heating/cooling applications in specific geographical areas, and includes tools necessary to do a preliminary design of the system and to analyze its economic benefits. The following are included: the case for solar energy; solar radiation and weather; passive solar design; system characteristics and selection; component performance criteria; determining solar system thermal performance and economic feasibility; requirements, availability, and applications of solar heating systems; and sources of additional information.more » (MHR)« less
Radiation Risks From A Weak Field in the Coming Years
NASA Astrophysics Data System (ADS)
Rahmanifard, F.; Schwadron, N.; Smith, C. W.; Joyce, C. J.; Townsend, L.
2017-12-01
Recent solar conditions, including a prolonged solar minimum (2005-2009) and the recent small solar maximum, indicate that we are entering an era of lower solar activity than observed at other times during the space age- possibly similar to the past solar grand minima. During such periods of extremely low activity, the fluxes of galactic cosmic rays (GCRs) increase dramatically and limit the allowable days for human space missions. We use data from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter (LRO) to examine the correlation between the heliospheric magnetic field at 1AU and the modulation potential of the GCRs. We apply past grand solar minima conditions, including the Maunder minimum (1645-1715) and the Dalton minimum (1790-1830), to predict the modulation potential and the dose rates of the GCRs throughout the next solar cycle. The heliospheric magnetic field can drop to 4.21 (3.72) nT, leading to a modulation potential of 448.51 (235.96) MV and dose rates as high as 11.72 (16.68) cGy/yr for the case of conditions similar to the Dalton minimum (Maunder minimum). We use these results to predict the most conservative estimations of the time to 3% risk of exposure-induced death (REID) and the allowable mission durations in interplanetary space.
Alignment and Initial Operation of an Advanced Solar Simulator
NASA Technical Reports Server (NTRS)
Jaworske, Donald A.; Jefferies, Kent S.; Mason, Lee S.
1996-01-01
A solar simulator utilizing nine 30-kW xenon arc lamps was built to provide radiant power for testing a solar dynamic space power system in a thermal vacuum environment. The advanced solar simulator achieved the following values specific to the solar dynamic system: (1) a subtense angle of 1 deg; (2) the ability to vary solar simulator intensity up to 1.7 kW/sq m; (3) a beam diameter of 4.8 m; and (4) uniformity of illumination on the order of +/-10%. The flexibility of the solar simulator design allows for other potential uses of the facility.
Evaluation of solar cells for potential space satellite power applications
NASA Technical Reports Server (NTRS)
1977-01-01
The evaluation focused on the following subjects: (1) the relative merits of alternative solar cell materials, based on performance and availability, (2) the best manufacturing methods for various solar cell options and the effects of extremely large production volumes on their ultimate costs and operational characteristics, (3) the areas of uncertainty in achieving large solar cell production volumes, (4) the effects of concentration ratios on solar array mass and system performance, (5) the factors influencing solar cell life in the radiation environment during transport to and in geosynchronous orbit, and (6) the merits of conducting solar cell manufacturing operations in space.
Genomics for paediatricians: promises and pitfalls.
Hammond, Carrie Louise; Willoughby, Josh Matthew; Parker, Michael James
2018-03-24
In recent years, there have been significant advances in genetic technologies, evolving the field of genomics from genetics. This has huge diagnostic potential, as genomic testing increasingly becomes part of mainstream medicine. However, there are numerous potential pitfalls in the interpretation of genomic data. It is therefore essential that we educate clinicians more widely about the appropriate interpretation and utilisation of genomic testing. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
The Geography of Solar Energy.
ERIC Educational Resources Information Center
LaHart, David E.; Allen, Rodney F.
1984-01-01
After learning about two promising techniques for generating electricity--photovoltaic cells and wind energy conversion systems--secondary students analyze two maps of the United States showing solar radiation and available wind power to determine which U.S. regions have potential for these solar electric systems. (RM)
Analysis of Solar Potential of Roofs Based on Digital Terrain Model
NASA Astrophysics Data System (ADS)
Gorički, M.; Poslončec-Petrić, V.; Frangeš, S.; Bačić, Ž.
2017-09-01
One of the basic goals of the smart city concept is to create a high-quality environment that is long sustainable and economically justifiable. The priority and concrete goal today is to promote and provide sustainable sources of energy (SSE). Croatia is rich with sun energy and as one of the sunniest European countries, it has a huge insufficiently used solar potential at its disposal. The paper describes the procedure of analysing the solar potential of a pilot area Sveti Križ Začretje by means of digital surface model (DSM) and based on the data available in the Meteorological and Hydrological Service of the Republic of Croatia. Although a more detailed analysis would require some additional factors, it is clear that the installation of 19,6m2 of solar panels in each household could cover annual requirements of the household in the analysed area, the locality Sveti Križ Začretje.
Study terrestrial applications of solar cell powered systems
NASA Technical Reports Server (NTRS)
Ravin, J. W.
1973-01-01
Terrestrial applications of solar cells and design systems are considered for those applications that show the most promise for becoming practical and accepted by users within the next five years. The study includes the definition, categorization, evaluation and screening of the most attractive potential terrestrial applications for solar cells. Potential markets are initially grouped and categorized in a general sense and are weighted in priority by their business volume, present and future. From a categorized list including marine, transportation, security, communication, meteorological and others, 66 potential solar cell applications have been cataloged. A methodology was formulated to include the criteria for evaluation and screening. The evaluation process covers all parts and components of the complete system required for each application and gives consideration to all factors, such as engineering, economic, production, marketing and other factors that may have an influence on the acceptance of the system.
NASA Technical Reports Server (NTRS)
Ferguson, Dale C.; Hillard, G. Barry
1994-01-01
SAMPIE, the Solar Array Module Plasma Interactions Experiment, flew in the Space Shuttle Columbia payload bay as part of the Office of Aeronautics and Space Technology-2 (OAST-2) mission on STS-62, March, 1994. SAMPIE biased samples of solar arrays and space power materials to varying potentials with respect to the surrounding space plasma, and recorded the plasma currents collected and the arcs which occurred, along with a set of plasma diagnostics data. A large set of high quality data was obtained on the behavior of solar arrays and space power materials in the space environment. This paper is the first report on the data SAMPIE telemetered to the ground during the mission. It will be seen that the flight data promise to help determine arcing thresholds, snapover potentials, and floating potentials for arrays and spacecraft in LEO.
Integrating Wind and Solar on the Grid-NREL Analysis Leads the Way -
shown in color, but not including pink/IESO area.) Map provided by NREL Integrating Wind and Solar on the Grid-NREL Analysis Leads the Way NREL studies confirm big wind, solar potential for grid integration To fully harvest the nation's bountiful wind and solar resources, it is critical to know how much
Modeling photovoltaic performance in periodic patterned colloidal quantum dot solar cells.
Fu, Yulan; Dinku, Abay G; Hara, Yukihiro; Miller, Christopher W; Vrouwenvelder, Kristina T; Lopez, Rene
2015-07-27
Colloidal quantum dot (CQD) solar cells have attracted tremendous attention mostly due to their wide absorption spectrum window and potentially low processability cost. The ultimate efficiency of CQD solar cells is highly limited by their high trap state density. Here we show that the overall device power conversion efficiency could be improved by employing photonic structures that enhance both charge generation and collection efficiencies. By employing a two-dimensional numerical model, we have calculated the characteristics of patterned CQD solar cells based of a simple grating structure. Our calculation predicts a power conversion efficiency as high as 11.2%, with a short circuit current density of 35.2 mA/cm2, a value nearly 1.5 times larger than the conventional flat design, showing the great potential value of patterned quantum dot solar cells.
NASA Astrophysics Data System (ADS)
Hayashi, K.
2013-11-01
We present a model of a time-dependent three-dimensional magnetohydrodynamics simulation of the sub-Alfvenic solar corona and super-Alfvenic solar wind with temporally varying solar-surface boundary magnetic field data. To (i) accommodate observational data with a somewhat arbitrarily evolving solar photospheric magnetic field as the boundary value and (ii) keep the divergence-free condition, we developed a boundary model, here named Confined Differential Potential Field model, that calculates the horizontal components of the magnetic field, from changes in the vertical component, as a potential field confined in a thin shell. The projected normal characteristic method robustly simulates the solar corona and solar wind, in response to the temporal variation of the boundary Br. We conduct test MHD simulations for two periods, from Carrington Rotation number 2009 to 2010 and from Carrington Rotation 2074 to 2075 at solar maximum and minimum of Cycle 23, respectively. We obtained several coronal features that a fixed boundary condition cannot yield, such as twisted magnetic field lines at the lower corona and the transition from an open-field coronal hole to a closed-field streamer. We also obtained slight improvements of the interplanetary magnetic field, including the latitudinal component, at Earth.
Wang, Jun; Liu, Shurong; Mu, Yannan; Liu, Li; A, Runa; Yang, Jiandong; Zhu, Guijie; Meng, Xianwei; Fu, Wuyou; Yang, Haibin
2017-11-01
Vertically aligned CdTe nanorods (NRs) arrays are successfully grown by a simple one-step and template-free electrodeposition method, and then embedded in the CdS window layer to form a novel three-dimensional (3D) heterostructure on flexible substrates. The parameters of electrodeposition such as deposition potential and pH of the solution are varied to analyze their important role in the formation of high quality CdTe NRs arrays. The photovoltaic conversion efficiency of the solar cell based on the 3D heterojunction structure is studied in detail. In comparison with the standard planar heterojunction solar cell, the 3D heterojunction solar cell exhibits better photovoltaic performance, which can be attributed to its enhanced optical absorption ability, increased heterojunction area and improved charge carrier transport. The better photoelectric property of the 3D heterojunction solar cell suggests great application potential in thin film solar cells, and the simple electrodeposition process represents a promising technique for large-scale fabrication of other nanostructured solar energy conversion devices. Copyright © 2017 Elsevier Inc. All rights reserved.
Solar-terrestrial coupling through atmospheric electricity
NASA Technical Reports Server (NTRS)
Roble, R. G.; Hays, P. B.
1979-01-01
There are a number of measurements of electrical variations that suggest a solar-terrestrial influence on the global atmospheric electrical circuit. The measurements show variations associated with solar flares, solar magnetic sector boundary crossings, geomagnetic activity, aurorae, differences between ground current and potential gradients at high and low latitudes, and solar cycle variations. The evidence for each variation is examined. Both the experimental evidence and the calculations made with a global model of atmospheric electricity indicate that there is solar-terrestrial coupling through atmospheric electricity which operates by altering the global electric current and field distribution. A global redistribution of currents and fields can be caused by large-scale changes in electrical conductivity, by alteration of the columnar resistance between thunderstorm cloud tops and the ionosphere, or by both. If the columnar resistance is altered above thunderstorms, more current will flow in the global circuit, changing the ionospheric potential and basic circuit variables such as current density and electric fields. The observed variations of currents and fields during solar-induced disturbances are generally less than 50% of mean values near the earth's surface.
Future Trends in Solar Radio Astronomy and Coronal Magnetic-Field Measurements
NASA Astrophysics Data System (ADS)
Fleishman, Gregory; Nita, Gelu; Gary, Dale
Solar radio astronomy has an amazingly rich, but yet largely unexploited, potential for probing the solar corona and chromosphere. Radio emission offers multiple ways of detecting and tracking electron beams, studying chromospheric and coronal thermal structure, plasma processes, particle acceleration, and measuring magnetic fields. To turn the mentioned potential into real routine diagnostics, two major components are needed: (1) well-calibrated observations with high spatial, spectral, and temporal resolutions and (2) accurate and reliable theoretical models and fast numerical tools capable of recovering the emission source parameters from the radio data. This report gives a brief overview of the new, expanded, and planned radio facilities, such as Expanded Owens Valley Solar Array (EOVSA), Jansky Very Large Array (JVLA), Chinese Solar Radio Heliograph (CSRH), Upgraded Siberian Solar Radio Telescope (USSRT), and Frequency Agile Solar Radiotelescope (FASR) with the emphasis on their ability to measure the coronal magnetic fields in active regions and flares. In particular, we emphasize the new tools for 3D modeling of the radio emission and forward fitting tools in development needed to derive the magnetic field data from the radio measurements.
USAF solar thermal applications case studies
NASA Technical Reports Server (NTRS)
1981-01-01
The potential of solar energy technologies to meet mission related applications for process heat was investigated. The reduction of the dependence of military installations on fossil fuels by promoting the use of more abundant resources where liquid hydrocarbons and natural gas are now used is examined. The evaluation and utilization of renewable energy systems to provide process heat and space heating are emphasized. The application of thermal energy systems is divided into four steps: (1) investigation of the potential operational cost effectiveness of selected thermal technologies; (2) selection of a site and preliminary design of point focussing solar thermal plant; (3) construction and test of an engineering prototype; and (4) installation and operation of a solar thermal energy plant.
Maloney, Stephen; Moss, Alan; Ilic, Dragan
2014-12-01
Social Networking Sites (SNS) have seen exponential growth in recent years. The high utilisation of SNS by tertiary students makes them an attractive tool for educational institutions. This study aims to identify health professional students' use and behaviours with SNS, including students' perspectives on potential applications within health professional curricula. Students enrolled in an undergraduate physiotherapy program were invited to take part in an anonymous, online questionnaire at the end of 2012. The survey consisted of 20 items, gathering demographic data, information on current use of SNS, and opinions regarding the application of SNS into education. Both quantitative and qualitative data were gathered. A total of 142 students, from all years of study, completed the online questionnaire. Only two participants were not current users of social media. Facebook and YouTube had been utilised for educational purposes by 97 and 60 % of participants respectively; 85 % believed that SNS could benefit their learning experience. Only five respondents were not interested in following peers, academic staff, clinicians or professional associations on Facebook. Four key themes emerged: peer collaboration, need for separation between personal and professional realms, complimentary learning and enhanced communication. Students wish to make educational connections via SNS, yet expressed a strong desire to maintain privacy, and a distinction between personal and professional lives. Educational utilisation of SNS may improve communication speed and accessibility. Any educator involvement should be viewed with caution.
Abu-Zaineh, Mohammad; Mataria, Awad; Moatti, Jean-Paul; Ventelou, Bruno
2011-01-01
Socioeconomic-related inequalities in healthcare delivery have been extensively studied in developed countries, using standard linear models of decomposition. This paper seeks to assess equity in healthcare delivery in the particular context of the occupied Palestinian territory: the West Bank and the Gaza Strip, using a new method of decomposition based on microsimulations. Besides avoiding the 'unavoidable price' of linearity restriction that is imposed by the standard methods of decomposition, the microsimulation-based decomposition enables to circumvent the potentially contentious role of heterogeneity in behaviours and to better disentangle the various sources driving inequality in healthcare utilisation. Results suggest that the worse-off do have a disproportinately greater need for all levels of care. However with the exception of primary-level, utilisation of all levels of care appears to be significantly higher for the better-off. The microsimulation method has made it possible to identify the contributions of factors driving such pro-rich patterns. While much of the inequality in utilisation appears to be caused by the prevailing socioeconomic inequalities, detailed analysis attributes a non-trivial part (circa 30% of inequalities) to heterogeneity in healthcare-seeking behaviours across socioeconomic groups of the population. Several policy recommendations for improving equity in healthcare delivery in the occupied Palestinian territory are proposed. Copyright © 2010 Elsevier Ltd. All rights reserved.
Blay, Nicole; Donoghue, Judith
2003-01-01
The role of the nursing manager has evolved from clinician and bed manager to one with greater accountability for evidence based practice, benchmarking and more recently, budget liability. Casemix data are widely believed to be a means of providing essential information for effective decision making and financial management but have not been widely utilised by nursing managers (Diers & Bozzo, 1999). This paper will report the results of a survey of nursing managers in seven hospitals within a metropolitan area health service. The hospitals include tertiary referral hospitals, specialist public hospitals and an affiliated public hospital for aged care and rehabilitation services. The survey sought to establish what casemix and related data were provided to nurse managers, who provided these data and how supplied data were utilised by the nurse managers. Results demonstrated that the majority of nursing managers surveyed received minimal (if any) casemix and/or demographic data on a routine basis. Some were provided with data in response to specific requests. The information that was provided varied both within and across hospitals, and no consistent methods of data distribution were available. Few nursing managers believed that the information provided aided their decision-making processes partly due to the minimalist nature of provided data while some nursing managers demonstrated a lack of understanding of the potential benefit of casemix data as a resource to support management decision making.
Utilisation of mucin glycans by the human gut symbiont Ruminococcus gnavus is strain-dependent.
Crost, Emmanuelle H; Tailford, Louise E; Le Gall, Gwenaelle; Fons, Michel; Henrissat, Bernard; Juge, Nathalie
2013-01-01
Commensal bacteria often have an especially rich source of glycan-degrading enzymes which allow them to utilize undigested carbohydrates from the food or the host. The species Ruminococcus gnavus is present in the digestive tract of ≥90% of humans and has been implicated in gut-related diseases such as inflammatory bowel diseases (IBD). Here we analysed the ability of two R. gnavus human strains, E1 and ATCC 29149, to utilize host glycans. We showed that although both strains could assimilate mucin monosaccharides, only R. gnavus ATCC 29149 was able to grow on mucin as a sole carbon source. Comparative genomic analysis of the two R. gnavus strains highlighted potential clusters and glycoside hydrolases (GHs) responsible for the breakdown and utilization of mucin-derived glycans. Transcriptomic and functional activity assays confirmed the importance of specific GH33 sialidase, and GH29 and GH95 fucosidases in the mucin utilisation pathway. Notably, we uncovered a novel pathway by which R. gnavus ATCC 29149 utilises sialic acid from sialylated substrates. Our results also demonstrated the ability of R. gnavus ATCC 29149 to produce propanol and propionate as the end products of metabolism when grown on mucin and fucosylated glycans. These new findings provide molecular insights into the strain-specificity of R. gnavus adaptation to the gut environment advancing our understanding of the role of gut commensals in health and disease.
Hall, Kerry K; Chang, Anne B; Anderson, Jennie; Arnold, Daniel; Otim, Michael; O'Grady, Kerry-Ann F
2018-06-01
The majority of Australia's Aboriginal and/or Torres Strait Islander children live in urban areas; however, little is known about their health service use. We aimed to describe health service utilisation amongst a cohort of urban Aboriginal and/or Torres Strait Islander children aged <5 years. We analysed health service utilisation data collected in an ongoing prospective cohort study of children aged <5 years registered with an Aboriginal-owned and operated primary health-care service. Enrolled children were followed monthly for 12 months, with data on health service utilisation collected at baseline and at each monthly follow-up. Health service utilisation rates, overall and by service provider and reason for presentation, were calculated and reported as incidence rates per 100 child-months with the corresponding 95% confidence intervals (CIs). Between February 2013 and November 2015, 180 children were enrolled, and 1541 child-months of observation were available for analysis. The overall incidence of health service utilisation was 52.5 per 100 child-months (95% CI 48.7-56.5); 81% of encounters were with general practitioners. Presentation rates were the highest for acute respiratory illnesses (30.7/100 child-months, 95% CI 27.8-33.9). In this community, acute respiratory illnesses are predominant causes of health service utilisation in young children. The health-care utilisation profile of these children presents important opportunities for health promotion and intervention. © 2018 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).
2013-01-01
Background Older people from culturally and linguistically diverse groups are underrepresented in residential aged care but overrepresented in community aged care in Australia. However, little is known about culturally and linguistically diverse family caregivers in utilising dementia services in Australia because previous studies mainly focused on the majority cultural group. Experiences of caregivers from culturally and linguistically diverse groups who are eligible to utilise dementia services in Australia are needed in order to optimize the utilisation of dementia services for these caregivers. Methods The aim of the study was to explore the experiences of family caregivers from Chinese, Greek, Italian and Vietnamese groups in utilising dementia services. Gadamer's philosophical hermeneutics was used to interpret the experiences of the participants. Focus group discussions and in-depth individual interviews were used to collect data. Data collection was conducted over a six month period in 2011. In total, 46 family caregivers who were caring for 39 persons with dementia participated. Results Four themes were revealed: (1) negotiating services for the person with dementia; (2) the impact of acculturation on service utilisation; (3) the characteristics of satisfactory services; and (4) negative experiences in utilising services. The present study revealed that the participation of caregivers from culturally and linguistically diverse groups in planning and managing dementia services ranged markedly from limited participation to full participation. Conclusions The findings of this study suggest that caregivers from culturally and linguistically diverse groups need to be fully prepared so they can participate in the utilisation of dementia services available to them in Australia. PMID:24148155
Xiao, Lily Dongxia; De Bellis, Anita; Habel, Lesley; Kyriazopoulos, Helena
2013-10-22
Older people from culturally and linguistically diverse groups are underrepresented in residential aged care but overrepresented in community aged care in Australia. However, little is known about culturally and linguistically diverse family caregivers in utilising dementia services in Australia because previous studies mainly focused on the majority cultural group. Experiences of caregivers from culturally and linguistically diverse groups who are eligible to utilise dementia services in Australia are needed in order to optimize the utilisation of dementia services for these caregivers. The aim of the study was to explore the experiences of family caregivers from Chinese, Greek, Italian and Vietnamese groups in utilising dementia services. Gadamer's philosophical hermeneutics was used to interpret the experiences of the participants. Focus group discussions and in-depth individual interviews were used to collect data. Data collection was conducted over a six month period in 2011. In total, 46 family caregivers who were caring for 39 persons with dementia participated. Four themes were revealed: (1) negotiating services for the person with dementia; (2) the impact of acculturation on service utilisation; (3) the characteristics of satisfactory services; and (4) negative experiences in utilising services. The present study revealed that the participation of caregivers from culturally and linguistically diverse groups in planning and managing dementia services ranged markedly from limited participation to full participation. The findings of this study suggest that caregivers from culturally and linguistically diverse groups need to be fully prepared so they can participate in the utilisation of dementia services available to them in Australia.
Analysis of penumbral eclipse data
NASA Technical Reports Server (NTRS)
Garrett, H. B.
1977-01-01
Two days of data from the ATS-6 1976 eclipse season were analyzed to determine the effects of varying photoelectron flux on spacecraft potential. Particular emphasis was placed on the variation in potential as the satellite entered the earth's penumbra. Measurements from the AE-C satellite of the solar UV radiation were used to construct a model of atmospheric attenuation. This model was found to be consistent with direct measurements of the variations in photoelectron flux as Injun 5 passed into eclipse. Applying the model to the ATS-6 data gave the time dependency of the solar illumination/photoelectron flux as the satellite was eclipsed. This relationship, when combined with the ATS-6 measurements of satellite potential, revealed a nearly linear relation between the solar illumination/photoelectron flux and the logarithm of the satellite potential.
NASA Astrophysics Data System (ADS)
Klise, G. T.; Tidwell, V. C.; Macknick, J.; Reno, M. D.; Moreland, B. D.; Zemlick, K. M.
2013-12-01
In the Southwestern United States, there are many large utility-scale solar photovoltaic (PV) and concentrating solar power (CSP) facilities currently in operation, with even more under construction and planned for future development. These are locations with high solar insolation and access to large metropolitan areas and existing grid infrastructure. The Bureau of Land Management, under a reasonably foreseeable development scenario, projects a total of almost 32 GW of installed utility-scale solar project capacity in the Southwest by 2030. To determine the potential impacts to water resources and the potential limitations water resources may have on development, we utilized methods outlined by the Bureau of Land Management (BLM) to determine potential water use in designated solar energy zones (SEZs) for construction and operations & maintenance (O&M), which is then evaluated according to water availability in six Southwestern states. Our results indicate that PV facilities overall use less water, however water for construction is high compared to lifetime operational water needs. There is a transition underway from wet cooled to dry cooled CSP facilities and larger PV facilities due to water use concerns, though some water is still necessary for construction, operations, and maintenance. Overall, ten watersheds, 9 in California, and one in New Mexico were identified as being of particular concern because of limited water availability. Understanding the location of potentially available water sources can help the solar industry determine locations that minimize impacts to existing water resources, and help understand potential costs when utilizing non-potable water sources or purchasing existing appropriated water. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.
Three-Dimensional Reconstruction and Solar Energy Potential Estimation of Buildings
NASA Astrophysics Data System (ADS)
Chen, Y.; Li, M.; Cheng, L.; Xu, H.; Li, S.; Liu, X.
2017-12-01
In the context of the construction of low-carbon cities, green cities and eco-cities, the ability of the airborne and mobile LiDAR should be explored in urban renewable energy research. As the main landscape in urban environment, buildings have large regular envelopes could receive a huge amount of solar radiation. In this study, a relatively complete calculation scheme about building roof and façade solar utilization potential is proposed, using building three-dimensional geometric feature information. For measuring the city-level building solar irradiance, the precise three-dimensional building roof and façade models should be first reconstructed from the airborne and mobile LiDAR, respectively. In order to obtaining the precise geometric structure of building facades from the mobile LiDAR data, a new method for structure detection and the three-dimensional reconstruction of building façades from mobile LiDAR data is proposed. The method consists of three steps: the preprocessing of façade points, the detection of façade structure, the restoration and reconstruction of building façade. As a result, the reconstruction method can effectively deal with missing areas caused by occlusion, viewpoint limitation, and uneven point density, as well as realizing the highly complete 3D reconstruction of a building façade. Furthermore, the window areas can be excluded for more accurate estimation of solar utilization potential. After then, the solar energy utilization potential of global building roofs and facades is estimate by using the solar irradiance model, which combine the analysis of the building shade and sky diffuse, based on the analysis of the geometrical structure of buildings.
ERIC Educational Resources Information Center
von Hippel, Frank; Williams, Robert H.
1975-01-01
As fossil fuels decrease in availability and environmental concerns increase, soalr energy is becoming a potential major energy source. Already solar energy is used for space heating in homes. Proposals for solar-electric generating systems include land-based or ocean-based collectors and harnessing wind and wave power. Photosynthesis can also…
Solar energy for industrial process heat
NASA Technical Reports Server (NTRS)
Barbieri, R. H.; Pivirotto, D. L.
1979-01-01
Findings of study of potential use for solar energy utilization by California dairy industry, prove that applicable solar energy system furnish much of heat needed for milk processing with large savings in expenditures for oil and gas and ensurance of adequate readily available sources of process heat.
[The immune system and the eye].
Faber, Carsten; Nissen, Mogens Holst
2008-09-15
The special relationship between the eye and the immune system rests on a number of anatomical, physiological and immunological mechanisms. These mechanisms prevent the delicate structures of the eye from potentially damaging immunogenic inflammation while protecting against pathogens. Rather than inflammation, antigen induces a form of systemic and antigen-specific immunological tolerance. Owing to its systemic nature, this tolerance may be utilised to achieve successful treatment of immunological disorders.
ERIC Educational Resources Information Center
Blackman, Stacey
2011-01-01
The transformative potential of pupils' voices is well documented in past research by Pedder and McIntyre; and Cooper and McIntyre. In this qualitative research, I utilise a social constructivist framework by Vygotsky to ask pupils with dyslexia about the kinds of teacher strategies that they find helpful to their learning at secondary school in…
Yu Wei; Erin J. Belval; Matthew P. Thompson; Dave E. Calkin; Crystal S. Stonesifer
2016-01-01
Sharing fire engines and crews between fire suppression dispatch zones may help improve the utilisation of fire suppression resources. Using the Resource Ordering and Status System, the Predictive Servicesâ Fire Potential Outlooks and the Rocky Mountain Region Preparedness Levels from 2010 to 2013, we tested a simulation and optimisation procedure to transfer crews and...
High-performance, low-cost solar collectors for disinfection of contaminated water.
Vidal, A; Diaz, A I
2000-01-01
Although the germicidal action of sunlight has long been recognized, its potential for practical applications has to be researched more thoroughly. This paper summarizes the progress made toward a commercially practical collector for solar disinfection applications. Nontracking compound parabolic collectors (CPCs), developed originally for capturing solar photons for thermal energy applications, were examined as potential solar photoreactors. A field demonstration of solar disinfection treatment using commercially manufactured solar reactors was conducted. Field tests showed successful destruction of Escherichia coli and Enterococcus faecalis and have provided data for full-scale design of water treatment systems. From above observations, a throughput value of 50 L/m2 h for the low-cost CPC reactor tested was estimated. For a 190 m3/d (0.05 MGD) facility, the estimated total costs for disinfection using UV-A is U.S. $0.19/m3 ($0.70/1000 gal). The use of near-UV sunlight to disinfect water supplies seems promising in rural communities of developing countries where treated water is unavailable.
Gu, Di; Gao, Simeng; Jiang, TingTing; Wang, Baohui
2017-03-15
To match the relentless pursuit of three research hot points - efficient solar utilization, green and sustainable remediation of wastewater and advanced oxidation processes, solar-mediated thermo-electrochemical oxidation of surfactant was proposed and developed for green remediation of surfactant wastewater. The solar thermal electrochemical process (STEP), fully driven with solar energy to electric energy and heat and without an input of other energy, sustainably serves as efficient thermo-electrochemical oxidation of surfactant, exemplified by SDBS, in wastewater with the synergistic production of hydrogen. The electrooxidation-resistant surfactant is thermo-electrochemically oxidized to CO 2 while hydrogen gas is generated by lowing effective oxidation potential and suppressing the oxidation activation energy originated from the combination of thermochemical and electrochemical effect. A clear conclusion on the mechanism of SDBS degradation can be proposed and discussed based on the theoretical analysis of electrochemical potential by quantum chemical method and experimental analysis of the CV, TG, GC, FT-IR, UV-vis, Fluorescence spectra and TOC. The degradation data provide a pilot for the treatment of SDBS wastewater that appears to occur via desulfonation followed by aromatic-ring opening. The solar thermal utilization that can initiate the desulfonation and activation of SDBS becomes one key step in the degradation process.
Gu, Di; Gao, Simeng; Jiang, TingTing; Wang, Baohui
2017-01-01
To match the relentless pursuit of three research hot points - efficient solar utilization, green and sustainable remediation of wastewater and advanced oxidation processes, solar-mediated thermo-electrochemical oxidation of surfactant was proposed and developed for green remediation of surfactant wastewater. The solar thermal electrochemical process (STEP), fully driven with solar energy to electric energy and heat and without an input of other energy, sustainably serves as efficient thermo-electrochemical oxidation of surfactant, exemplified by SDBS, in wastewater with the synergistic production of hydrogen. The electrooxidation-resistant surfactant is thermo-electrochemically oxidized to CO2 while hydrogen gas is generated by lowing effective oxidation potential and suppressing the oxidation activation energy originated from the combination of thermochemical and electrochemical effect. A clear conclusion on the mechanism of SDBS degradation can be proposed and discussed based on the theoretical analysis of electrochemical potential by quantum chemical method and experimental analysis of the CV, TG, GC, FT-IR, UV-vis, Fluorescence spectra and TOC. The degradation data provide a pilot for the treatment of SDBS wastewater that appears to occur via desulfonation followed by aromatic-ring opening. The solar thermal utilization that can initiate the desulfonation and activation of SDBS becomes one key step in the degradation process. PMID:28294180
NASA Technical Reports Server (NTRS)
Lang, Jared J.; Randolph, Thomas M.; McElrath, Timothy P.; Baker, John D.; Strange, Nathan J.; Landau, Damon; Wallace, Mark S.; Snyder, J. Steve; Piacentine, Jamie S.; Malone, Shane;
2011-01-01
Near Earth Objects (NEOs) and other primitive bodies are exciting targets for exploration. Not only do they provide clues to the early formation of the universe, but they also are potential resources for manned exploration as well as provide information about potential Earth hazards. As a step toward exploration outside Earth's sphere of influence, NASA is considering manned exploration to Near Earth Asteroids (NEAs), however hazard characterization of a target is important before embarking on such an undertaking. A small Solar Electric Propulsion (SEP) spacecraft would be ideally suited for this type of mission due to the high delta-V requirements, variety of potential targets and locations, and the solar energy available in the inner solar system.Spacecraft and mission trades have been performed to develop a robust spacecraft design that utilizes low cost, off-the-shelf components that could accommodate a suite of different scientific payloads for NEO characterization. Mission concepts such as multiple spacecraft each rendezvousing with different NEOs, single spacecraft rendezvousing with separate NEOs, NEO landers, as well as other inner solar system applications (Mars telecom orbiter) have been evaluated. Secondary launch opportunities using the Expendable Secondary Payload Adapter (ESPA) Grande launch adapter with unconstrained launch dates have also been examined.
NASA Astrophysics Data System (ADS)
Gu, Di; Gao, Simeng; Jiang, Tingting; Wang, Baohui
2017-03-01
To match the relentless pursuit of three research hot points - efficient solar utilization, green and sustainable remediation of wastewater and advanced oxidation processes, solar-mediated thermo-electrochemical oxidation of surfactant was proposed and developed for green remediation of surfactant wastewater. The solar thermal electrochemical process (STEP), fully driven with solar energy to electric energy and heat and without an input of other energy, sustainably serves as efficient thermo-electrochemical oxidation of surfactant, exemplified by SDBS, in wastewater with the synergistic production of hydrogen. The electrooxidation-resistant surfactant is thermo-electrochemically oxidized to CO2 while hydrogen gas is generated by lowing effective oxidation potential and suppressing the oxidation activation energy originated from the combination of thermochemical and electrochemical effect. A clear conclusion on the mechanism of SDBS degradation can be proposed and discussed based on the theoretical analysis of electrochemical potential by quantum chemical method and experimental analysis of the CV, TG, GC, FT-IR, UV-vis, Fluorescence spectra and TOC. The degradation data provide a pilot for the treatment of SDBS wastewater that appears to occur via desulfonation followed by aromatic-ring opening. The solar thermal utilization that can initiate the desulfonation and activation of SDBS becomes one key step in the degradation process.
Utilisation of a community-based health facility in a low-income urban community in Ibadan, Nigeria
Asuzu, Michael C.
2015-01-01
Background Primary healthcare is established to ensure that people have access to health services through facilities located in their community. However, utilisation of health facilities in Nigeria remains low in many communities. Aim To assess the utilisation of community-based health facility (CBHF) amongst adults in Ibadan, Nigeria Settings A low-income community in Ibadan North West Local Government Area of Oyo State. Methods A cross-sectional survey was conducted using a simple random sampling technique to select one adult per household in all 586 houses in the community. A semi-structured interviewer-administered questionnaire was used to collect information on respondents' sociodemographic characteristics, knowledge and utilisation of the CBHF. Data analysis included descriptive statistics and association testing using the Chi-square test at p = 0.05. Results The mean age of the respondents was 46.5 ± 16.0 years; 46.0% were men and 81.0% married; 26% had no formal education and 38.0% had secondary-level education and above; traders constituted 52.0% of the sample; and 85.2% were of low socioeconomic standing; 90% had patronised the CBHF. The main reasons for non-utilisation were preference for general hospitals (13.8%) and self-medication (12.1%). Respondents who had secondary education and above, were in a higher socioeconomic class, who had good knowledge of the facility and were satisfied with care, utilised the CBHF three months significantly more than their counterparts prior to the study (p < 0.05). However, only satisfaction with care was found to be a significant predictor of utilisation of the CBHF. Conclusion The utilisation of the CBHF amongst adults in the study setting is high, driven mostly by satisfaction with the care received previously. Self-medication, promoted by uncontrolled access to drugs through pharmacies and patent medicine stores, threatens this high utilisation. PMID:26245600
Solar glare hazard analysis tool on account of determined points of time
Ho, Clifford K; Sims, Cianan Alexander
2014-09-23
Technologies pertaining to determining when glare will be perceived by a hypothetical observer from a glare source and the intensity of glare that will be perceived by the hypothetical observer from the glare source are described herein. A first location of a potential source of solar glare is received, and a second location of the hypothetical observer is received. Based upon such locations, including respective elevations, and known positions of the sun over time, a determination as to when the hypothetical observer will perceive glare from the potential source of solar glare is made. Subsequently, an amount of irradiance entering the eye of the hypothetical observer is calculated to assess potential ocular hazards.
A Solar Dynamic Power Option for Space Solar Power
NASA Technical Reports Server (NTRS)
Mason, Lee S.
1999-01-01
A study was performed to determine the potential performance and related technology requirements of Solar Dynamic power systems for a Space Solar Power satellite. Space Solar Power is a concept where solar energy is collected in orbit and beamed to Earth receiving stations to supplement terrestrial electric power service. Solar Dynamic systems offer the benefits of high solar-to-electric efficiency, long life with minimal performance degradation, and high power scalability. System analyses indicate that with moderate component development, SD systems can exhibit excellent mass and deployed area characteristics. Using the analyses as a guide, a technology roadmap was -enerated which identifies the component advances necessary to make SD power generation a competitive option for the SSP mission.
NASA Technical Reports Server (NTRS)
Wu, S. T. (Editor); Christensen, D. L.; Head, R. R.
1978-01-01
Demonstration projects, systems-subsystems simulation programs, applications (heating, cooling, agricultural, industrial), and climatic data testing (standards, economics, institutional) are the topics of the book. Economics of preheating water for commercial use and collecting, processing, and dissemination of data for the national demonstration program are discussed. Computer simulation of a solar energy system and graphical representation of solar collector performance are considered. Attention is given to solar driven heat pumps, solar cooling equipment, hybrid passive/active solar systems, and solar farm buildings. Evaluation of a thermographic scanning device for solar energy and conservation applications, use of meteorological data in system evaluation, and biomass conversion potential are presented.
Polestitters: Using Solar Sails for Constant Real-time Sensing of Earth's Polar Regions
NASA Astrophysics Data System (ADS)
Mulligan, P.; Diedrich, B. L.; Barnes, N.; Derbes, B.
2012-12-01
NASA has funded the Sunjammer mission - a near term demonstration of solar sail technology (2014/15). Sunjammer has the potential to demonstrate stationkeeping out of Earth's orbital plane. This is a first step in achieving "polesitter" orbits with year-round, real-time visibility of Earth's polar regions. Potential applications for such missions are illustrated. Solar sails have long been a concept for spacecraft propulsion that works by exchanging momentum with sunlight reflected by large, lightweight, mirrored sails. In addition to enabling propellantless propulsion throughout the solar system and beyond, their continuous thrust enables artificial Lagrange orbits (ALOs), some of which can be called "polesitter" orbits, with 24-hour, year-round visibility of Earth's polar regions. Several potential Earth remote sensing applications have been identified that address the limited temporal and spatial coverage from traditional polar and geostationary satellites. The Galileo spacecraft during its 1990 Earth flyby acquired imagery and radiometer data similar to the view from a polesitter. The Galileo imagery was used to derive aerosols and cloud variations used in atmospheric motion vector (AMV) derivations. Composites of satellite imagery over the South Pole is routinely used to derive atmospheric motion vectors like those performed regularly from geostationary satellites. The JAXA IKAROS mission flew a 14x14m solar sail past Venus in 2010. Sunjammer will demonstrate a state of the art 38x38m solar sail from Earth to an artificial Lagrange orbit located sunward and north of the sun-Earth L1 point. Traditional spacecraft can orbit naturally occurring Lagrange equilibrium points between the sun and Earth. The low, continuous thrust of solar sails can change where these points occur, creating new orbits with a variety of potential applications including polar remote sensing, space weather monitoring, and polar communications. This figure illustrates a selection of possible solar sail orbits around the sun-Earth L1 and L2 points.
NASA Astrophysics Data System (ADS)
Hoffacker, M. K.; Hernandez, R. R.; Field, C. B.
2013-12-01
Solar energy is an archetype renewable energy technology with great potential to reduce greenhouse gas emissions when substituted for carbon-intensive energy. Utility-scale solar energy (USSE; i.e., > 1 MW) necessitates large quantities of space making the efficient use of land for USSE development critical to realizing its full potential. However, studies elucidating the interaction between land-use and utility-scale solar energy (USSE) are limited. In this study, we assessed 1) the theoretical and technical potential of terrestrial-based USSE systems, and 2) land-use and land-cover change impacts from actual USSE installations (> 20 MW; planned, under construction, operating), using California as a case study due to its early adoption of renewable energy systems, unique constraints on land availability, immense energy demand, and vast natural resources. We used topo-climatic (e.g., slope, irradiance), infrastructural (e.g., proximity to transmission lines), and ecological constraints (e.g., threatened and endangered species) to determine highly favorable, favorable, and unfavorable locations for USSE and to assess its technical potential. We found that the theoretical potential of photovoltaic (PV) and concentrating solar power (CSP) in California is 26,097 and 29,422 kWh/m2/day, respectively. We identified over 150 planned, under construction, and operating USSE installations in California, ranging in size from 20 to 1,000 MW. Currently, 29% are located on shrub- and scrublands, 23% on cultivated crop land, 13% on pasture/hay areas, 11% on grassland/herbaceous and developed open space, and 7% in the built environment. Understanding current land-use decisions of USSE systems and assessing its future potential can be instructive for achieving land, energy, and environmental compatibility, especially for other global regions that share similar resource demands and limitations.
NASA Astrophysics Data System (ADS)
Chan, A. A.; Ilie, R.; Elkington, S. R.; Albert, J.; Huie, W.
2017-12-01
It has been traditional to separate radiation belt radial-diffusion coefficients into two contributions: an "electrostatic" diffusion coefficient, which is assumed to be due to a potential (non-inductive) electric field, and an "electromagnetic" diffusion coefficient , which is assumed to be due to the combined effect of an inductive electric field and the corresponding time-dependent magnetic field. One difficulty in implementing this separation when using magnetospheric fields obtained from measurements, or from MHD simulations, is that only the total electric field is given; the separation of the electric field into potential and inductive parts is not readily available. In this work we separate the electric field using a numerical method based on the Helmholtz decomposition of the total motional electric field calculated by the BATS-R-US MHD code. The inner boundary for the electric potential is based on the Ridley Ionospheric Model solution and we assume floating boundary conditions in the solar wind. Using different idealized solar wind drivers, including a solar wind density that is oscillating at a single frequency or with a broad spectrum of frequencies, we calculate potential and inductive electric fields, electric and magnetic power spectral densities, and corresponding radial diffusion coefficients. Simulations driven by idealized solar wind conditions show a clear separation of the potential and inductive contributions to the power spectral densities and diffusion coefficients. Simulations with more realistic solar wind drivers are underway to better assess the use of electrostatic and electromagnetic diffusion coefficients in understanding ULF wave-particle interactions in Earth's radiation belts.
Danielson, Samantha J; Rappaport, Charles A; Loher, Michael K; Gehlbach, Brian K
2018-06-01
Critically ill patients exhibit profound disturbances of circadian rhythmicity, most commonly in the form of a phase delay. We investigated the specific zeitgeber properties of a medical intensive care unit to develop a model that explained these abnormalities. Prospective, observational study conducted during 2013-2014. Twenty-four-hour ambient light (lux, 672 hours) and sound pressure levels (dBA, 504 hours) were measured in patient rooms. Patients and families were surveyed regarding their perceptions of the environment. University-based adult medical intensive care unit. The timing and intensity of the ambient light-dark cycle and sound environment and the relationship of these measurements to patient/family perceptions. Twenty-four-hour light-dark cycles were extremely weak and phase delayed relative to the solar cycle. Morning light averaged 12.1 (4.8, 37.2) lux, when only 24.9% ± 10.9% of available light was utilised; yet patients and families did not identify low daytime light levels as problematic. Median noise levels were invariably excessive (nighttime 47.9 [45.0, 51.3] dBA) with minimal variation, consistent with the absence of a defined rest period. The intensive care unit functions as a near-constant routine protocol disconnected from solar time. Behavioural interventions to promote entrainment should be supported by objective measurements of light and sound. Copyright © 2017 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Meftah, M.; Bolsée, D.; Damé, L.; Hauchecorne, A.; Pereira, N.; Irbah, A.; Bekki, S.; Cessateur, G.; Foujols, T.; Thiéblemont, R.
2016-12-01
Accurate measurements of the solar spectral irradiance (SSI) and its temporal variations are of primary interest to better understand solar mechanisms, and the links between solar variability and Earth's atmosphere and climate. The SOLar SPECtrum (SOLSPEC) instrument of the Solar Monitoring Observatory (SOLAR) payload onboard the International Space Station (ISS) has been built to carry out SSI measurements from 165 to 3088 nm. We focus here on the ultraviolet (UV) part of the measured solar spectrum (wavelengths less than 400 nm) because the UV part is potentially important for understanding the solar forcing of Earth's atmosphere and climate. We present here SOLAR/SOLSPEC UV data obtained since 2008, and their variations in three spectral bands during Solar Cycle 24. They are compared with previously reported UV measurements and model reconstructions, and differences are discussed.
NASA Astrophysics Data System (ADS)
Catalano, G.; Povero, P.; Fabiano, M.; Benedetti, F.; Goffart, A.
1997-01-01
The relationships among vertical stability, estimated nutrient utilisation and particulate organic matter in the Ross Sea are analysed from data collected during two cruises in the summers of 1987-1988 and 1989-1990. In the upper mixed layer (UML), identified through the vertical stability E( Z(UML)), nutrient consumption is calculated as the difference between the "diluted" nutrient value and the mean calculated from the integrated value in the UML. The nutrient utilisation ratio and E( Z(UML)) are linearly related for E( Z(UML))≤25, whereas for values > 25, the distribution pattern is more scattered and independent of E( Z(UML)). For E( Z(UML))≥25, utilisation values were ≥4, 0.4 and 10 mmol m -3 for nitrate, phosphate and silicate, respectively. Significant relationships between nutrient depletion and both particulate organic carbon (POC) and particulate protein/particulate carbohydrate ratios (PPRT/PCHO) are found. The analysis of particulate matter distribution vs nutrient utilisation shows that the stations could be divided into two groups having different characteristics. The first group includes coastal stations, where high nutrient utilisation, POC and PPRT/PCHO are typical of areas with high production. In the second group (pelagic stations), nutrient utilisation, POC and PPRT/PCHO are lower. The vertical stability can be used to discriminate among the factors that influence primary production.
Social determinants of dental health services utilisation of Greek adults.
Pavi, E; Karampli, E; Zavras, D; Dardavesis, T; Kyriopoulos, J
2010-09-01
To identify the determinants of dental care utilisation among Greek adults, with a particular emphasis on socio-economic determinants. Data were collected through a national survey on health and health care services utilisation of a sample of 4,003 Greek adults stratified by geographic region, age and gender. A purpose made questionnaire was used during face-to-face interviews. A 2-stage model was developed to assess the impact of independent variables on dental utilisation likelihood and frequency. 39.6% (1,562) of Greek adults reported having visited a dentist within the last year. Among dental attenders, 32.6% reported prevention as the reason for visit. Statistically significant differences in dental care utilisation were observed in relation to demographic, socioeconomic and lifestyle factors. Logistic regression analysis showed that gender, age, income, education, place of residence, private insurance coverage and self-rated oral health are important determinants of dental services utilisation. Mean number of dental visits within previous year was 1.6. Results from Poisson regression analysis indicated that lower income level correlates to lower number of dental visits, while having visited for treatment (rather than for prevention) correlated to higher number of dental visits. Greek adults do not exhibit satisfactory dental visiting behaviour. Extent of care sought is associated with need for treatment rather than preventive reasons. The findings confirm the existence of socioeconomic inequalities in dental services utilisation among Greek adults.
Olaleye, Olubukola Adebisi; Lawal, Zainab Iyabo
2017-03-01
To investigate the pattern of referral for and utilisation of physiotherapy in the continuum of stroke care at a tertiary hospital in Ibadan, Nigeria. Referral notes and medical records of patients admitted in the University College Hospital, Ibadan with a clinical diagnosis of stroke between January, 2009 and December, 2013 were retrospectively reviewed. Information on age, sex, type of stroke, length of hospital stay, referral for physiotherapy and utilisation of physiotherapy were retrieved. Data were summarised using descriptive statistics and analysed using Chi-square test. A total of 783 patients with stroke were admitted in the hospital during the period under study. The in-patient mortality rate was 37.2%. The mean Length of Hospital Stay (LoHS) was 16.17±12.34 days. Referral rate for physiotherapy was high (75.8%) and the mean time from admission to referral for physiotherapy was three days. Majority of patients referred utilised physiotherapy (63.4%) and mean number of physiotherapy sessions received during in-patient care was 8.69±6.45. There was a significant association between LoHS and utilisation of in-patientphysiotherapy (p=0.02). The referral rate of stroke patients for physiotherapy was relatively high. Utilisation of in-patient physiotherapy reduced length of hospital stay among patients with stroke. Utilisation of out-patient physiotherapy was low. Strategies to enhance out-patient utilisation should be explored.
Heliogyro Solar Sail Research at NASA
NASA Technical Reports Server (NTRS)
Wilkie, W. Keats; Warren, Jerry E.; Guerrant, Daniel V.; Lawrence, Dale A.; Gibbs, S. Chad; Dowell, Earl H.; Heaton, Andrew F.; Heaton, Andrew F.; Juang, Jer-Nan; Horta, Lucas G.;
2013-01-01
The recent successful flight of the JAXA IKAROS solar sail has renewed interest within NASA in spinning solar sail concepts for high-performance solar sailing. The heliogyro solar sail, in particular, is being re-examined as a potential game-changing architecture for future solar sailing missions. In this paper, we present an overview of ongoing heliogyro technology development and feasibility assessment activities within NASA. In particular, a small-scale heliogyro solar sail technology demonstration concept will be described. We will also discuss ongoing analytical and experimental heliogyro structural dynamics and controls investigations and provide an outline of future heliogyro development work directed toward enabling a low cost heliogyro technology demonstration mission ca. 2020.
USAF solar thermal applications overview
NASA Technical Reports Server (NTRS)
Hauger, J. S.; Simpson, J. A.
1981-01-01
Process heat applications were compared to solar thermal technologies. The generic process heat applications were analyzed for solar thermal technology utilization, using SERI's PROSYS/ECONOMAT model in an end use matching analysis and a separate analysis was made for solar ponds. Solar technologies appear attractive in a large number of applications. Low temperature applications at sites with high insolation and high fuel costs were found to be most attractive. No one solar thermal technology emerges as a clearly universal or preferred technology, however,, solar ponds offer a potential high payoff in a few, selected applications. It was shown that troughs and flat plate systems are cost effective in a large number of applications.
An Overview of Solar Sail Propulsion within NASA
NASA Technical Reports Server (NTRS)
Johnson, Les; Swartzlander, Grover A.; Artusio-Glimpse, Alexandra
2013-01-01
Solar Sail Propulsion (SSP) is a high-priority new technology within The National Aeronautics and Space Administration (NASA), and several potential future space missions have been identified that will require SSP. Small and mid-sized technology demonstration missions using solar sails have flown or will soon fly in space. Multiple mission concept studies have been performed to determine the system level SSP requirements for their implementation and, subsequently, to drive the content of relevant technology programs. The status of SSP technology and potential future mission implementation within the United States (US) will be described.
Strategy for outer planets exploration
NASA Technical Reports Server (NTRS)
1975-01-01
NASA's Planetary Programs Office formed a number of scientific working groups to study in depth the potential scientific return from the various candidate missions to the outer solar system. The results of these working group studies were brought together in a series of symposia to evaluate the potential outer planet missions and to discuss strategies for exploration of the outer solar system that were consistent with fiscal constraints and with anticipated spacecraft and launch vehicle capabilities. A logical, scientifically sound, and cost effective approach to exploration of the outer solar system is presented.
Land availability and land value assessment for solar ponds in the United States
NASA Technical Reports Server (NTRS)
1982-01-01
The land availability and land values for solar ponds in the United States as they concern the residential, commercial, and institutional land use categories were investigated. Solar ponds were identified as efficient and economical means for collecting and storing direct and diffuse solar energy. Innovative methodologies were applied to arrive at regional projections regarding the amount of land that might potentially be available for retrofit or future solar pond applications. Regional land values were also documented and analyzed.
NASA Astrophysics Data System (ADS)
Yang, Yang; Xu, Di; Wu, Qingyong; Diao, Peng
2016-10-01
Solar powered hydrogen evolution reaction (HER) is one of the key reactions in solar-to-chemical energy conversion. It is desirable to develop photocathodic materials that exhibit high activity toward photoelectrochemical (PEC) HER at more positive potentials because a higher potential means a lower overpotential for HER. In this work, the Cu2O/CuO bilayered composites were prepared by a facile method that involved an electrodeposition and a subsequent thermal oxidation. The resulting Cu2O/CuO bilayered composites exhibited a surprisingly high activity and good stability toward PEC HER, expecially at high potentials in alkaline solution. The photocurrent density for HER was 3.15 mA·cm-2 at the potential of 0.40 V vs. RHE, which was one of the two highest reported at the same potential on copper-oxide-based photocathode. The high photoactivity of the bilayered composite was ascribed to the following three advantages of the Cu2O/CuO heterojunction: (1) the broadened light absorption band that made more efficient use of solar energy, (2) the large space-charge-region potential that enabled a high efficiency for electron-hole separation, and (3) the high majority carrier density that ensured a faster charge transportation rate. This work reveals the potential of the Cu2O/CuO bilayered composite as a promising photocathodic material for solar water splitting.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stone, Deborah; Oakleaf, Laura
The Cook County Community Solar project set out to unlock the potential of community solar in the Chicago region with lessons that could be applied nationally. One of the first steps was to prove out the potential market. This was done through an opportunity assessment which showed there is over 9,000 megawatts worth of site capacity available for community solar projects in Cook County – nearly enough to offset all of Cook County’s residential electricity use. The assessment also showed that almost 75% of Cook County households are not able to invest directly in solar photovoltaic systems due to amore » variety of issues from physical barriers such as shading, or condition of the roof, to financial barriers such as lack of roof ownership, or the up-front costs of installation. Because of these barriers, community solar is an essential part of making the benefits of renewable energy available to all of the residents of Cook County. In addition to the opportunity assessment the project team also worked with the over 200 individuals who participated in the stakeholder advisory group to develop a number of other products including: 1) an Economic & Policy Barriers Resolutions and Work Plan document which laid out best practices to address the policy barriers that existed at the time (May of 2016) 2) Value Proposition Report I and Report II which summarize the value of community solar to potential developers and subscribers, 3) The Community Solar Business Case Tool, which provides a flexible financial model that projects the costs and befits to the system developer and subscriber for a project, 4) Bill Crediting Analysis and the 5) Final Report. The Final Report contains 15 case studies which prove that community solar projects are economically feasible in Cook County with a variety of sites, solar designs, ownership and subscriber models.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hewett, R.
1997-12-31
This paper describes the strategy and computer processing system that NREL, the Virginia Department of Mines, Minerals and Energy (DMME) and the state energy office, are developing for computing solar attractiveness scores for state agencies and the individual facilities or buildings within each agency. In the case of an agency, solar attractiveness is a measure of that agency`s having a significant number of facilities for which solar has the potential to be promising. In the case of a facility, solar attractiveness is a measure of its potential for being good, economically viable candidate for a solar waste heating system. Virginiamore » State agencies are charged with reducing fossil energy and electricity use and expense. DMME is responsible for working with them to achieve the goals and for managing the state`s energy consumption and cost monitoring program. This is done using the Fast Accounting System for Energy Reporting (FASER) computerized energy accounting and tracking system and database. Agencies report energy use and expenses (by individual facility and energy type) to DMME quarterly. DMME is also responsible for providing technical and other assistance services to agencies and facilities interested in investigating use of solar. Since Virginia has approximately 80 agencies operating over 8,000 energy-consuming facilities and since DMME`s resources are limited, it is interested in being able to determine: (1) on which agencies to focus; (2) specific facilities on which to focus within each high-priority agency; and (3) irrespective of agency, which facilities are the most promising potential candidates for solar. The computer processing system described in this paper computes numerical solar attractiveness scores for the state`s agencies and the individual facilities using the energy use and cost data in the FASER system database and the state`s and NREL`s experience in implementing, testing and evaluating solar water heating systems in commercial and government facilities.« less
Zhu, Laipan; Wang, Longfei; Xue, Fei; Chen, Libo; Fu, Jianqiang; Feng, Xiaolong; Li, Tianfeng
2016-01-01
The piezo‐phototronic effect is about the enhanced separation, transport, and recombination of the photogenerated carriers using the piezoelectric polarization charges present in piezoelectric‐semiconductor materials. Here, it is presented that the piezo‐phototronic effect can be effectively applied to improve the relative conversion efficiency of a flexible solar cell based on n‐ZnO/p‐SnS core–shell nanowire array for 37.3% under a moderate vertical pressure. The performance of the solar cell can be effectively enhanced by a gentle bending of the device, showing its potential for application in curly geometries. This study not only adds further understanding about the concept of increasing solar energy conversion efficiency via piezo‐phototronic effect, but also demonstrates the great potential of piezo‐phototronic effect in the application of large‐scale, flexible, and lightweight nanowire array solar cells. PMID:28105394
Zhu, Laipan; Wang, Longfei; Xue, Fei; Chen, Libo; Fu, Jianqiang; Feng, Xiaolong; Li, Tianfeng; Wang, Zhong Lin
2017-01-01
The piezo-phototronic effect is about the enhanced separation, transport, and recombination of the photogenerated carriers using the piezoelectric polarization charges present in piezoelectric-semiconductor materials. Here, it is presented that the piezo-phototronic effect can be effectively applied to improve the relative conversion efficiency of a flexible solar cell based on n-ZnO/p-SnS core-shell nanowire array for 37.3% under a moderate vertical pressure. The performance of the solar cell can be effectively enhanced by a gentle bending of the device, showing its potential for application in curly geometries. This study not only adds further understanding about the concept of increasing solar energy conversion efficiency via piezo-phototronic effect, but also demonstrates the great potential of piezo-phototronic effect in the application of large-scale, flexible, and lightweight nanowire array solar cells.
Rwabufigiri, Bernard N; Mukamurigo, Judith; Thomson, Dana R; Hedt-Gautier, Bethany L; Semasaka, Jean Paul S
2016-05-31
Postnatal care (PNC) in the first seven days is important for preventing morbidity and mortality in mothers and new-borns. Sub-Saharan African countries, which account for 62 % of maternal deaths globally, have made major efforts to increase PNC utilisation, but utilisation rates remains low even in countries like Rwanda where PNC services are universally available for free. This study identifies key socio-economic and demographic factors associated with PNC utilisation in Rwanda to inform improved PNC policies and programs. This is a secondary analysis of the 2010 Demographic and Health Survey, a national multi-stage, cross-sectional survey. In bivariate analysis, we used chi-square tests to identify demographic and socio-economic factors associated with PNC utilisation at α = 0.1. Pearson's R statistic (r > 0.5) was used to identify collinear covariates, and to choose which covariate was more strongly associated with PNC utilisation. Manual backward stepwise logistic regression was performed on the remaining covariates to identify key factors associated with PNC utilisation at α = 0.05. All analyses were performed in Stata 13 adjusting for sampling weights, clustering, and stratification. Of the 2,748 women with a live birth in the last two years who answered question about PNC utilisation, 353 (12.8 %) returned for PNC services within seven days after birth. Three factors were positively associated with PNC use: delivering at a health facility (OR: 2.97; 95 % CI: 2.28-3.87), being married but not involved with one's own health care decision-making (OR: 1.69; 95 % CI: 1.17, 2.44) compared to being married and involved; and being in the second (OR: 1.46; 95 % CI: 1.01-2.09) or richest wealth quintile (OR: 2.04; 95 % CI: 1.27-3.29) compared to the poorest. Mother's older age at delivery was negatively associated with PNC use (20-29 - OR: 0.51, 95 % CI: 0.29-0.87; 30-39 - OR: 0.47, 95 % CI: 0.27-0.83; 40-49 - OR: 0.32, 95 % CI: 0.16-0.64). Low PNC utilisation in Rwanda appears to be a universal problem though older age and poverty are further barriers to PNC utilisation. A recent change in the provision of BCG vaccination to new-borns might promote widespread PNC utilisation. We further recommend targeted campaigns to older mothers and poorest mothers, focusing on perceptions of health system quality, cultural beliefs, and pregnancy risks.
2018-01-01
Background Inequalities in the utilisation of dental services in Brazil are remarkable. The aim of this study was to evaluate the association of contextual and individual factors with the utilisation of dental services by Brazilian adults using the Andersen’s behavioural model. Methods Individual-level data from 27,017 adults residents in the State capitals who were interviewed in the 2013 Brazilian National Health Survey were pooled with contextual city-level data. The outcomes were non-utilisation of dental services and last dental visit over 12 months ago. Individual predisposing variables were age, sex, race/skin colour, schooling and social network. Individual enabling variables included income, health insurance and registration in primary health care. Individual need variables were self-perceived dental health and self-reported missing teeth. Multilevel logistic regression models were performed to estimate odds ratio (OR) and 95% confidence intervals (95% CIs) of the association of contextual and individual predisposing, enabling and need-related variables with dental services outcomes. Results Predisposing (OR = 0.89; 95% CI 0.81–0.97) and enabling (OR = 0.90; 95% CI 0.85–0.96) contextual factors were associated with non-utilisation of dental services. Individual predisposing (sex, race/skin colour, schooling), enabling (income, health insurance) and need (self-perceived oral health, missing teeth) were associated with non-utilisation of dental services and last dental visit over 12 months ago. The latter was also associated with other individual predisposing (age, social network) and need (eating difficulties due to oral problems) characteristics. Conclusions Individual and contextual determinants influenced dental services utilisation in Brazilian adults. These factors should be on the policy agenda and considered in the organisation of health services aiming to reduce oral health inequalities related to access and utilisation of dental services. PMID:29420660
Herkrath, Fernando José; Vettore, Mario Vianna; Werneck, Guilherme Loureiro
2018-01-01
Inequalities in the utilisation of dental services in Brazil are remarkable. The aim of this study was to evaluate the association of contextual and individual factors with the utilisation of dental services by Brazilian adults using the Andersen's behavioural model. Individual-level data from 27,017 adults residents in the State capitals who were interviewed in the 2013 Brazilian National Health Survey were pooled with contextual city-level data. The outcomes were non-utilisation of dental services and last dental visit over 12 months ago. Individual predisposing variables were age, sex, race/skin colour, schooling and social network. Individual enabling variables included income, health insurance and registration in primary health care. Individual need variables were self-perceived dental health and self-reported missing teeth. Multilevel logistic regression models were performed to estimate odds ratio (OR) and 95% confidence intervals (95% CIs) of the association of contextual and individual predisposing, enabling and need-related variables with dental services outcomes. Predisposing (OR = 0.89; 95% CI 0.81-0.97) and enabling (OR = 0.90; 95% CI 0.85-0.96) contextual factors were associated with non-utilisation of dental services. Individual predisposing (sex, race/skin colour, schooling), enabling (income, health insurance) and need (self-perceived oral health, missing teeth) were associated with non-utilisation of dental services and last dental visit over 12 months ago. The latter was also associated with other individual predisposing (age, social network) and need (eating difficulties due to oral problems) characteristics. Individual and contextual determinants influenced dental services utilisation in Brazilian adults. These factors should be on the policy agenda and considered in the organisation of health services aiming to reduce oral health inequalities related to access and utilisation of dental services.
Inequalities in utilisation of general practitioner and specialist services in 9 European countries.
Stirbu, Irina; Kunst, Anton E; Mielck, Andreas; Mackenbach, Johan P
2011-10-31
The aim of this study is to describe the magnitude of educational inequalities in utilisation of general practitioner (GP) and specialist services in 9 European countries. In addition to West European countries, we have included 3 Eastern European countries: Hungary, Estonia and Latvia. To cover the gap in knowledge we pay a special attention to the magnitude of inequalities among patients with chronic conditions. Data on the use of GP and specialist services were derived from national health surveys of Belgium, Estonia, France, Germany, Hungary, Ireland, Latvia, the Netherlands and Norway. For each country and education level we calculated the absolute prevalence and relative inequalities in utilisation of GP and specialist services. In order to account for the need for care, the results were adjusted by the measure of self-assessed health. People with lower education used GP services equally often in most countries (except Belgium and Germany) compared with those with a higher level of education. At the same time people with a higher education used specialist care services significantly more often in all countries, except in the Netherlands. The general pattern of educational inequalities in utilisation of specialist care was similar for both men and women. Inequalities in utilisation of specialist care were equally large in Eastern European and in Western European countries, except for Latvia where the inequalities were somewhat larger. Similarly, large inequalities were found in the utilisation of specialist care among patients with chronic diseases, diabetes, and hypertension. We found large inequalities in the utilisation of specialist care. These inequalities were not compensated by utilisation of GP services. Of particular concern is the presence of inequalities among patients with a high need for specialist care, such as those with chronic diseases. © 2011 Stirbu et al; licensee BioMed Central Ltd.
Comparison of Solar Electric and Chemical Propulsion Missions
NASA Technical Reports Server (NTRS)
Freeh, Joshua E.; Burke, Laura M.; Sjauw, Waldy K.; McGuire, Melissa L.; Smith, Bryan K.
2015-01-01
Solar Electric Propulsion (SEP) offers fuel efficiency and mission robustness for spacecraft. The combination of solar power and electric propulsion engines is currently used for missions ranging from geostationary stationkeeping to deep space science because of these benefits. Both solar power and electric propulsion technologies have progressed to the point where higher electric power systems can be considered, making substantial cargo missions and potentially human missions viable. This paper evaluates and compares representative lunar, Mars, and Sun-Earth Langrangian point missions using SEP and chemical propulsion subsystems. The potential benefits and limitations are discussed along with technology gaps that need to be resolved for such missions to become possible. The connection to NASA's human architecture and technology development efforts will be discussed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kurup, Parthiv; Turchi, Craig
2015-11-01
After significant interest in the 1970s, but relatively few deployments, the use of solar technologies for thermal applications, including enhanced oil recovery (EOR), desalination, and industrial process heat (IPH), is again receiving global interest. In particular, the European Union (EU) has been a leader in the use, development, deployment, and tracking of Solar Industrial Process Heat (SIPH) plants. The objective of this study is to ascertain U.S. market potential of IPH for concentrating collector technologies that have been developed and promoted through the U.S. Department of Energy's Concentrating Solar Power (CSP) Program. For this study, the solar-thermal collector technologies ofmore » interest are parabolic trough collectors (PTCs) and linear Fresnel (LF) systems.« less
An analytical and experimental evaluation of the plano-cylindrical Fresnel lens solar concentrator
NASA Technical Reports Server (NTRS)
Hastings, L. J.; Allums, S. L.; Cosby, R. M.
1976-01-01
Plastic Fresnel lenses for solar concentration are attractive because of potential for low-cost mass production. An analytical and experimental evaluation of line-focusing Fresnel lenses with application potential in the 200 to 370 C range is reported. Analytical techniques were formulated to assess the solar transmission and imaging properties of a grooves-down lens. Experimentation was based primarily on a 56 cm-wide lens with f-number 1.0. A sun-tracking heliostat provided a non-moving solar source. Measured data indicated more spreading at the profile base than analytically predicted. The measured and computed transmittances were 85 and 87% respectively. Preliminary testing with a second lens (1.85 m) indicated that modified manufacturing techniques corrected the profile spreading problem.
Estimating Solar PV Output Using Modern Space/Time Geostatistics (Presentation)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lee, S. J.; George, R.; Bush, B.
2009-04-29
This presentation describes a project that uses mapping techniques to predict solar output at subhourly resolution at any spatial point, develop a methodology that is applicable to natural resources in general, and demonstrate capability of geostatistical techniques to predict the output of a potential solar plant.
Detecting drift bias and exposure errors in solar and photosynthetically active radiation data
USDA-ARS?s Scientific Manuscript database
All-black thermopile pyranometers are commonly used to measure solar radiation. Ensuring that the sensors are stable and free of drift is critical to accurately measure small variations in global solar irradiance (K'), which is a potential driver of changes in surface temperature. We demonstrate tha...
Circuits in the Sun: Solar Panel Physics
ERIC Educational Resources Information Center
Gfroerer, Tim
2013-01-01
Typical commercial solar panels consist of approximately 60 individual photovoltaic cells connected in series. Since the usual Kirchhoff rules apply, the current is uniform throughout the circuit, while the electric potential of the individual devices is cumulative. Hence, a solar panel is a good analog of a simple resistive series circuit, except…
The effect of sunshine testing on terrestrial solar cell system components
NASA Technical Reports Server (NTRS)
Forestieri, A. F.; Anagnostou, E.
1975-01-01
Samples of FEP encapsulated silicon solar cells and various potential encapsulation or cover materials were subjected to accelerated and real time testing. By measuring changes in solar cell output or optical transmission as a function of exposure the durability of the samples was evaluated. Results are presented.
Implementing Solar Technologies at Airports
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kandt, A.; Romero, R.
2014-07-01
Federal agencies, such as the Department of Defense and Department of Homeland Security, as well as numerous private entities are actively pursuing the installation of solar technologies to help reduce fossil fuel energy use and associated emissions, meet sustainability goals, and create more robust or reliable operations. One potential approach identified for siting solar technologies is the installation of solar energy technologies at airports and airfields, which present a significant opportunity for hosting solar technologies due to large amounts of open land. This report focuses largely on the Federal Aviation Administration's (FAA's) policies toward siting solar technologies at airports.
Solar heating and cooling of buildings
NASA Technical Reports Server (NTRS)
Bourke, R. D.; Davis, E. S.
1975-01-01
Solar energy has been used for space heating and water heating for many years. A less common application, although technically feasible, is solar cooling. This paper describes the techniques employed in the heating and cooling of buildings, and in water heating. The potential for solar energy to displace conventional energy sources is discussed. Water heating for new apartments appears to have some features which could make it a place to begin the resurgence of solar energy applications in the United States. A project to investigate apartment solar water heating, currently in the pilot plant construction phase, is described.
The Implementation of Advanced Solar Array Technology in Future NASA Missions
NASA Technical Reports Server (NTRS)
Piszczor, Michael F.; Kerslake, Thomas W.; Hoffman, David J.; White, Steve; Douglas, Mark; Spence, Brian; Jones, P. Alan
2003-01-01
Advanced solar array technology is expected to be critical in achieving the mission goals on many future NASA space flight programs. Current PV cell development programs offer significant potential and performance improvements. However, in order to achieve the performance improvements promised by these devices, new solar array structures must be designed and developed to accommodate these new PV cell technologies. This paper will address the use of advanced solar array technology in future NASA space missions and specifically look at how newer solar cell technologies impact solar array designs and overall power system performance.
Space Station Freedom solar array panels plasma interaction test facility
NASA Technical Reports Server (NTRS)
Martin, Donald F.; Mellott, Kenneth D.
1989-01-01
The Space Station Freedom Power System will make extensive use of photovoltaic (PV) power generation. The phase 1 power system consists of two PV power modules each capable of delivering 37.5 KW of conditioned power to the user. Each PV module consists of two solar arrays. Each solar array is made up of two solar blankets. Each solar blanket contains 82 PV panels. The PV power modules provide a 160 V nominal operating voltage. Previous research has shown that there are electrical interactions between a plasma environment and a photovoltaic power source. The interactions take two forms: parasitic current loss (occurs when the currect produced by the PV panel leaves at a high potential point and travels through the plasma to a lower potential point, effectively shorting that portion of the PV panel); and arcing (occurs when the PV panel electrically discharges into the plasma). The PV solar array panel plasma interaction test was conceived to evaluate the effects of these interactions on the Space Station Freedom type PV panels as well as to conduct further research. The test article consists of two active solar array panels in series. Each panel consists of two hundred 8 cm x 8 cm silicon solar cells. The test requirements dictated specifications in the following areas: plasma environment/plasma sheath; outgassing; thermal requirements; solar simulation; and data collection requirements.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Behrman, D.
The book concerns answers to the questions: (1) is solar energy the key to the future of our energy needs; and (2) what are the facts and true potential of this enormous, still largely unexplored source of renewable power. It reviews the knowledge of solar energy from the mirrors that Archimedes used to set a Roman fleet aflame in 215 B.C., to today's plans for designing attractive, affordable domestic solar housing, to tomorrow's dreams of building solar skyscrapers. Many of the sites and the technology applied to harness the Sun's power are described. Solar furnace towers, nine stories high, aremore » located in the Pyrennes in France; research is progressing on solar cells in Massachusetts; and many homes are heated and cooled through solar power. The systems to heat and cool the houses are described; what spatial and architectural modifications they necessitated, why there are still fewer than two hundred solar homes in existence, and what needs to be done before they can reach a mass market are also discussed. Also examined is the energy potential of windmills and the equatorial oceans, where at least 50 percent of the Sun's energy that falls on Earth is concentrated. Behrman reports on the progress of scientists and manufacturers toward making solar energy a viable competitor in the current energy market, and he studies the projections of a future energy crop to be raised on energy plantations. (MCW)« less
Argonne OutLoud presents: The Solar Energy Challenge
Darling, Seth
2018-02-19
To better understand the current and future role of solar energy, Argonne's Seth Darling framed the global energy supply and demand outlook over the next 40 years while examining potential energy sources from a feasibility and sustainability perspective. He also discussed the promise and challenges of solar energy while providing a broad overview of related research taking place at Argonne as well as his group's work on organic solar cells.
Argonne OutLoud presents: The Solar Energy Challenge
DOE Office of Scientific and Technical Information (OSTI.GOV)
Darling, Seth
To better understand the current and future role of solar energy, Argonne's Seth Darling framed the global energy supply and demand outlook over the next 40 years while examining potential energy sources from a feasibility and sustainability perspective. He also discussed the promise and challenges of solar energy while providing a broad overview of related research taking place at Argonne as well as his group's work on organic solar cells.
Earth-to-Geostationary Orbit Transportation for Space Solar Power System Development
NASA Technical Reports Server (NTRS)
Martin, James A.; Donahue, Benjamin B.; Lawrence, Schuyler C.; McClanahan, James A.; Carrington, Connie K. (Technical Monitor)
2000-01-01
Space solar power satellites have the potential to provide abundant quantities of electricity for use on Earth. One concept, the Sun Tower, can be assembled in geostationary orbit from pieces transferred from Earth. The cost of transportation is one of the major hurdles to space solar power. This study found that autonomous solar-electric transfer is a good choice for the transportation from LEO to GEO.
Suuronen, Anna; Muñoz-Escobar, Christian; Lensu, Anssi; Kuitunen, Markku; Guajardo Celis, Natalia; Espinoza Astudillo, Pablo; Ferrú, Marcos; Taucare-Ríos, Andrés; Miranda, Marcelo; Kukkonen, Jussi V K
2017-10-01
The renewable energy sector is growing at a rapid pace in northern Chile and the solar energy potential is one of the best worldwide. Therefore, many types of solar power plant facilities are being built to take advantage of this renewable energy resource. Solar energy is considered a clean source of energy, but there are potential environmental effects of solar technology, such as landscape fragmentation, extinction of local biota, microclimate changes, among others. To be able to minimize environmental impacts of solar power plants, it is important to know what kind of environmental conditions solar power plants create. This study provides information about abiotic and biotic conditions in the vicinity of photovoltaic solar power plants. Herein, the influence of these power plants as drivers of new microclimate conditions and arthropods diversity composition in the Atacama Desert was evaluated. Microclimatic conditions between panel mounts was found to be more extreme than in the surrounding desert yet beneath the panels temperature is lower and relative humidity higher than outside the panel area. Arthropod species composition was altered in fixed-mount panel installations. In contrast, solar tracking technology showed less influence on microclimate and species composition between Sun and Shade in the power plant. Shady conditions provided a refuge for arthropod species in both installation types. For example, Dipterans were more abundant in the shade whereas Solifugaes were seldom present in the shade. The presented findings have relevance for the sustainable planning and construction of solar power plants.
NASA Astrophysics Data System (ADS)
Suuronen, Anna; Muñoz-Escobar, Christian; Lensu, Anssi; Kuitunen, Markku; Guajardo Celis, Natalia; Espinoza Astudillo, Pablo; Ferrú, Marcos; Taucare-Ríos, Andrés; Miranda, Marcelo; Kukkonen, Jussi V. K.
2017-10-01
The renewable energy sector is growing at a rapid pace in northern Chile and the solar energy potential is one of the best worldwide. Therefore, many types of solar power plant facilities are being built to take advantage of this renewable energy resource. Solar energy is considered a clean source of energy, but there are potential environmental effects of solar technology, such as landscape fragmentation, extinction of local biota, microclimate changes, among others. To be able to minimize environmental impacts of solar power plants, it is important to know what kind of environmental conditions solar power plants create. This study provides information about abiotic and biotic conditions in the vicinity of photovoltaic solar power plants. Herein, the influence of these power plants as drivers of new microclimate conditions and arthropods diversity composition in the Atacama Desert was evaluated. Microclimatic conditions between panel mounts was found to be more extreme than in the surrounding desert yet beneath the panels temperature is lower and relative humidity higher than outside the panel area. Arthropod species composition was altered in fixed-mount panel installations. In contrast, solar tracking technology showed less influence on microclimate and species composition between Sun and Shade in the power plant. Shady conditions provided a refuge for arthropod species in both installation types. For example, Dipterans were more abundant in the shade whereas Solifugaes were seldom present in the shade. The presented findings have relevance for the sustainable planning and construction of solar power plants.
Semiconductor Nanocrystals as Light Harvesters in Solar Cells
Etgar, Lioz
2013-01-01
Photovoltaic cells use semiconductors to convert sunlight into electrical current and are regarded as a key technology for a sustainable energy supply. Quantum dot-based solar cells have shown great potential as next generation, high performance, low-cost photovoltaics due to the outstanding optoelectronic properties of quantum dots and their multiple exciton generation (MEG) capability. This review focuses on QDs as light harvesters in solar cells, including different structures of QD-based solar cells, such as QD heterojunction solar cells, QD-Schottky solar cells, QD-sensitized solar cells and the recent development in organic-inorganic perovskite heterojunction solar cells. Mechanisms, procedures, advantages, disadvantages and the latest results obtained in the field are described. To summarize, a future perspective is offered. PMID:28809318
Alexander, C J
1994-01-01
OBJECTIVE--To determine whether an arboreal lifestyle required full use of movement ranges underutilised in nine joint groups in humans, because under-utilisation of available movement range may be associated with susceptibility to primary osteoarthritis. METHODS--Utilisation of the nine joint groups was studied in two species of primate exercising in a simulated arboreal environment, using 'focal animal' observation techniques supplemented by telephoto photography and by review of archival material from other sources. Fifteen apes were observed over a total observation period of 20.2 man-hours and 152 films were analysed for utilisation of movement range. RESULTS--With one exception, all the movement ranges reported to be under-utilised in humans were fully utilised by the apes in climbing activities. The exception, metacarpophalangeal extension, was an essential component of the chimpanzee ground progression mode of knuckle walking. CONCLUSIONS--The underused movement range in several human joints is explicable as residual capacity from a semiarboreal lifestyle. If the correlation with primary osteoarthritis is confirmed, it suggests that the disease may reflect a disparity between inherited capacity and current need. The significance of the result lies in its implication that primary osteoarthritis may be preventable. Images PMID:7826133
Alexander, C J
1994-11-01
To determine whether an arboreal lifestyle required full use of movement ranges underutilised in nine joint groups in humans, because under-utilisation of available movement range may be associated with susceptibility to primary osteoarthritis. Utilisation of the nine joint groups was studied in two species of primate exercising in a simulated arboreal environment, using 'focal animal' observation techniques supplemented by telephoto photography and by review of archival material from other sources. Fifteen apes were observed over a total observation period of 20.2 man-hours and 152 films were analysed for utilisation of movement range. With one exception, all the movement ranges reported to be under-utilised in humans were fully utilised by the apes in climbing activities. The exception, metacarpophalangeal extension, was an essential component of the chimpanzee ground progression mode of knuckle walking. The underused movement range in several human joints is explicable as residual capacity from a semiarboreal lifestyle. If the correlation with primary osteoarthritis is confirmed, it suggests that the disease may reflect a disparity between inherited capacity and current need. The significance of the result lies in its implication that primary osteoarthritis may be preventable.
NASA Astrophysics Data System (ADS)
Chakraborty, Joheen; Banerji, Sugata
2018-03-01
Driven by a desire to control climate change and reduce the dependence on fossil fuels, governments around the world are increasing the adoption of renewable energy sources. However, among the US states, we observe a wide disparity in renewable penetration. In this study, we have identified and cleaned over a dozen datasets representing solar energy penetration in each US state, and the potentially relevant socioeconomic and other factors that may be driving the growth in solar. We have applied a number of predictive modeling approaches - including machine learning and regression - on these datasets over a 17-year period and evaluated the relative performance of the models. Our goals were: (1) identify the most important factors that are driving the growth in solar, (2) choose the most effective predictive modeling technique for solar growth, and (3) develop a model for predicting next year’s solar growth using this year’s data. We obtained very promising results with random forests (about 90% efficacy) and varying degrees of success with support vector machines and regression techniques (linear, polynomial, ridge). We also identified states with solar growth slower than expected and representing a potential for stronger growth in future.
Duan, Jialong; Hu, Tianyu; Zhao, Yuanyuan; He, Benlin; Tang, Qunwei
2018-05-14
Moisture is the worst enemy for state-of-the-art perovskite solar cells (PSCs). However, the flowing water vapor within nanoporous carbonaceous materials can create potentials. Therefore, it is a challenge to integrate water vapor and solar energies into a single PSC device. We demonstrate herein all-inorganic cesium lead bromide (CsPbBr 3 ) solar cells tailored with carbon electrodes to simultaneously harvest solar and water-vapor energy. Upon interfacial modification and plasma treatment, the bifunctional PSCs yield a maximum power conversion efficiency up to 9.43 % under one sun irradiation according to photoelectric conversion principle and a power output of 0.158 μW with voltage of 0.35 V and current of 0.45 μA in 80 % relative humidity through the flowing potentials at the carbon/water interface. The initial efficiency is only reduced by 2 % on exposing the inorganic PSC with 80 % humidity over 40 days. The successful realization of physical proof-of-concept multi-energy integrated solar cells provides new opportunities of maximizing overall power output. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Measurements of the Solar Spectral Irradiance Variability over Solar Cycles 21 to 24
NASA Astrophysics Data System (ADS)
Woods, T. N.
2017-12-01
The solar irradiance is the primary natural energy input into Earth's atmosphere and climate system. Understanding the long-term variations of the solar spectral irradiance (SSI) over time scales of the 11-year solar activity cycle and longer is critical for most Sun-climate research topics. There are satellite measurements of the SSI since the 1970s that contribute to understanding the solar cycle variability over Solar Cycles 21 to 24. A limiting factor for the accuracy of these results is the uncertainties for the instrument degradation corrections, for which there are fairly large corrections relative to the amount of solar cycle variability at some wavelengths. A summary of these satellite SSI measurements, which are primarily in the ultraviolet and only recently in the visible and near infrared, will be presented. Examining SSI trends using a new analysis technique is helping to identify some uncorrected instrumental trends, which once applied to the SSI trends has the potential to provide more accurate solar cycle variability results. This new technique examines the SSI trends at different levels of solar activity to provide long-term trends in a SSI record, and one of the most common components of these derived long-term trends is a downward trend that we attribute to being most likely from uncorrected instrument degradation. Examples of this analysis will be presented for some of the satellite SSI measurements to demonstrate this new technique and how it has potential to improve the understanding of solar cycle variability and to clarify the uncertainties of the trends.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Allegrini, E., E-mail: elia@env.dtu.dk; Butera, S.; Kosson, D.S.
Highlights: • Relevance of metal leaching in waste management system LCAs was assessed. • Toxic impacts from leaching could not be disregarded. • Uncertainty of toxicity, due to background activities, determines LCA outcomes. • Parameters such as pH and L/S affect LCA results. • Data modelling consistency and coverage within an LCA are crucial. - Abstract: Residues from industrial processes and waste management systems (WMSs) have been increasingly reutilised, leading to landfilling rate reductions and the optimisation of mineral resource utilisation in society. Life cycle assessment (LCA) is a holistic methodology allowing for the analysis of systems and products andmore » can be applied to waste management systems to identify environmental benefits and critical aspects thereof. From an LCA perspective, residue utilisation provides benefits such as avoiding the production and depletion of primary materials, but it can lead to environmental burdens, due to the potential leaching of toxic substances. In waste LCA studies where residue utilisation is included, leaching has generally been neglected. In this study, municipal solid waste incineration bottom ash (MSWI BA) was used as a case study into three LCA scenarios having different system boundaries. The importance of data quality and parameter selection in the overall LCA results was evaluated, and an innovative method to assess metal transport into the environment was applied, in order to determine emissions to the soil and water compartments for use in an LCA. It was found that toxic impacts as a result of leaching were dominant in systems including only MSWI BA utilisation, while leaching appeared negligible in larger scenarios including the entire waste system. However, leaching could not be disregarded a priori, due to large uncertainties characterising other activities in the scenario (e.g. electricity production). Based on the analysis of relevant parameters relative to leaching, and on general results of the study, recommendations are provided regarding the use of leaching data in LCA studies.« less
2011-01-01
Background Lactobacillus ruminis is a poorly characterized member of the Lactobacillus salivarius clade that is part of the intestinal microbiota of pigs, humans and other mammals. Its variable abundance in human and animals may be linked to historical changes over time and geographical differences in dietary intake of complex carbohydrates. Results In this study, we investigated the ability of nine L. ruminis strains of human and bovine origin to utilize fifty carbohydrates including simple sugars, oligosaccharides, and prebiotic polysaccharides. The growth patterns were compared with metabolic pathways predicted by annotation of a high quality draft genome sequence of ATCC 25644 (human isolate) and the complete genome of ATCC 27782 (bovine isolate). All of the strains tested utilized prebiotics including fructooligosaccharides (FOS), soybean-oligosaccharides (SOS) and 1,3:1,4-β-D-gluco-oligosaccharides to varying degrees. Six strains isolated from humans utilized FOS-enriched inulin, as well as FOS. In contrast, three strains isolated from cows grew poorly in FOS-supplemented medium. In general, carbohydrate utilisation patterns were strain-dependent and also varied depending on the degree of polymerisation or complexity of structure. Six putative operons were identified in the genome of the human isolate ATCC 25644 for the transport and utilisation of the prebiotics FOS, galacto-oligosaccharides (GOS), SOS, and 1,3:1,4-β-D-Gluco-oligosaccharides. One of these comprised a novel FOS utilisation operon with predicted capacity to degrade chicory-derived FOS. However, only three of these operons were identified in the ATCC 27782 genome that might account for the utilisation of only SOS and 1,3:1,4-β-D-Gluco-oligosaccharides. Conclusions This study has provided definitive genome-based evidence to support the fermentation patterns of nine strains of Lactobacillus ruminis, and has linked it to gene distribution patterns in strains from different sources. Furthermore, the study has identified prebiotic carbohydrates with the potential to promote L. ruminis growth in vivo. PMID:21995520
Dickson, Kwamena Sekyi; Darteh, Eugene Kofuor Maafo; Kumi-Kyereme, Akwasi
2017-03-14
Antenatal care is one of the three most essential care - antenatal, delivery and post-natal, given to women during pregnancy and has the potential to contribute towards the achievement of the Sustainable Development Goal (SDG) target 3.1- reducing the global maternal mortality ratio to less than 70 per 100,000 and target 3.8 - achieve universal health coverage. The main objective is to examine the contribution of the various providers of antenatal care services in Ghana from 1988 to 2014. The study uses data from all the six rounds of the Ghana Demographic and Health Survey (GDHS). Binary logistic regression models were applied to examine the association between background characteristics of respondents and providers of antenatal care services. The results show that majority of antenatal care services were provided by nurses over the period under review. The proportion of women who received antenatal care services from nurses improved over the period from 55% in 1988 to 89.5% in 2014. Moreover, there was a decline in antenatal care services provided by traditional birth attendants and women who did not receive antenatal care services from any service provider over the years under review. It was observed that women from rural areas were more likely to utilise antenatal care services provided by traditional birth attendants, whilst those from urban areas were more likely to utilise antenatal care from doctors and nurses. To further improve access to and utilisation of antenatal care services provided by nurses and doctors it is recommended that the Ghana Health Service and the Ministry of Health should put in place systems aimed at improving on the quality of care given such as regular training workshops for health personnel and assessment of patient's satisfaction with services provided. Also, they should encourage women in rural areas especially those from the savannah zone to utilise antenatal care services from skilled providers through social and behaviour change communication campaigns.
2013-01-01
Background Poor utilisation of facility-based antenatal and delivery care services in Kenya hampers reduction of maternal mortality. Studies suggest that the participation of men in antenatal and delivery care is associated with better health care seeking behaviour, yet many reproductive health programs do not facilitate their involvement. This qualitative study conducted in rural Western Kenya, explored men’s perceptions of antenatal and delivery care services and identified factors that facilitated or constrained their involvement. Methods Eight focus group discussions were conducted with 68 married men between 20-65 years of age in May 2011. Participants were of the Luo ethnic group residing in Asembo, western Kenya. The area has a high HIV-prevalence and polygamy is common. A topic guide was used to guide the discussions and a thematic framework approach for data analysis. Results Overall, men were positive in their views of antenatal and delivery care, as decision makers they often encouraged, some even ‘forced’, their wives to attend for antenatal or delivery care. Many reasons why it was beneficial to accompany their wives were provided, yet few did this in practice unless there was a clinical complication. The three main barriers relating to cultural norms identified were: 1) pregnancy support was considered a female role; and the male role that of provider; 2) negative health care worker attitudes towards men’s participation, and 3) couple unfriendly antenatal and delivery unit infrastructure. Conclusion Although men reported to facilitate their wives’ utilisation of antenatal and delivery care services, this does not translate to practice as adherence to antenatal-care schedules and facility based delivery is generally poor. Equally, reasons proffered why they should accompany their wives are not carried through into practice, with barriers outweighing facilitators. Recommendations to improve men involvement and potentially increase services utilisation include awareness campaigns targeting men, exploring promotion of joint HIV testing and counselling, staff training, and design of couple friendly antenatal and delivery units. PMID:23800139
Macdonald, Sara; Blane, David; Browne, Susan; Conway, Ellie; Macleod, Una; May, Carl; Mair, Frances
2016-11-01
How and when we use health services or healthcare provision has dominated exploration of and debates around healthcare access. Levels of utilisation are assumed as a proxy for access. Yet, focusing on utilisation conceals an important aspect of the access conundrum: the relationships that patients and potential patients have with the healthcare system and the professionals within those systems. Candidacy has been proposed as an antidote to traditional utilisation models. The Candidacy construct offers the ability to include patient-professional aspects alongside utilisation and thus promotes a deeper understanding of access. Originally applied to healthcare access for vulnerable populations, additional socio-demographic factors, including age and ethnicity, have also been shown to influence the Candidacy process. Here we propose a further extension of the Candidacy construct and illustrate the importance of illness identities when accessing healthcare. Drawing on a secondary data analysis of three data sets of qualitative interviews from colorectal cancer and heart failure patients we found that though similar access issues are apparent pre-diagnosis, diagnosis marks a critical juncture in the experience of access. Cancer patients describe a person-centred responsive healthcare system where their patienthood requires only modest assertion. Cancer speaks for itself. In marked contrast heart failure patients, describe struggling within a seemingly impermeable system to understand their illness, its implications and their own legitimacy as patients. Our work highlights the pressing need for healthcare professionals, systems and policies to promote a person centred approach, which is responsive and timely, regardless of illness category. To achieve this, attitudes regarding the importance or priority afforded to different categories of illness need to be tackled as they directly influence ideas of Candidacy and consequently access and experiences of care. Copyright © 2016 Elsevier Ltd. All rights reserved.
Global Magnetohydrodynamic Modeling of the Solar Corona
NASA Technical Reports Server (NTRS)
Linker, Jon A.
1998-01-01
The coronal magnetic field defines the structure of the solar corona, the position of the heliospheric current sheet, the regions of fast and slow solar wind, and the most likely sites of coronal mass ejections. There are few measurements of the magnetic fields in the corona, but the line-of-sight component of the global magnetic fields in the photosphere have been routinely measured for many years (for example, at Stanford's Wilcox Solar Observatory, and at the National Solar Observatory at Kitt Peak). The SOI/MDI instrument is now providing high-resolution full-disk magnetograms several times a day. Understanding the large-scale structure of the solar corona and inner heliosphere requires accurately mapping the measured photospheric magnetic field into the corona and outward. Ideally, a model should not only extrapolate the magnetic field, but should self-consistently reconstruct both the plasma and magnetic fields in the corona and solar wind. Support from our NASA SR&T contract has allowed us to develop three-dimensional magnetohydrodynamic (MHD) computations of the solar corona that incorporate observed photospheric magnetic fields into the boundary conditions. These calculations not only describe the magnetic field in the corona and interplanetary spice, but also predict the plasma properties as well. Our computations thus far have been successful in reproducing many aspects of both coronal and interplanetary data, including the structure of the streamer belt, the location of coronal hole boundaries, and the position and shape of the heliospheric current sheet. The most widely used technique for extrapolating the photospheric magnetic field into the corona and heliosphere are potential field models, such as the potential field source-surface model (PFSS),and the potential field current-sheet (PFCS) model
Flow photochemistry: Old light through new windows
Knowles, Jonathan P; Elliott, Luke D
2012-01-01
Summary Synthetic photochemistry carried out in classic batch reactors has, for over half a century, proved to be a powerful but under-utilised technique in general organic synthesis. Recent developments in flow photochemistry have the potential to allow this technique to be applied in a more mainstream setting. This review highlights the use of flow reactors in organic photochemistry, allowing a comparison of the various reactor types to be made. PMID:23209538
From synchrotron radiation to lab source: advanced speckle-based X-ray imaging using abrasive paper
NASA Astrophysics Data System (ADS)
Wang, Hongchang; Kashyap, Yogesh; Sawhney, Kawal
2016-02-01
X-ray phase and dark-field imaging techniques provide complementary and inaccessible information compared to conventional X-ray absorption or visible light imaging. However, such methods typically require sophisticated experimental apparatus or X-ray beams with specific properties. Recently, an X-ray speckle-based technique has shown great potential for X-ray phase and dark-field imaging using a simple experimental arrangement. However, it still suffers from either poor resolution or the time consuming process of collecting a large number of images. To overcome these limitations, in this report we demonstrate that absorption, dark-field, phase contrast, and two orthogonal differential phase contrast images can simultaneously be generated by scanning a piece of abrasive paper in only one direction. We propose a novel theoretical approach to quantitatively extract the above five images by utilising the remarkable properties of speckles. Importantly, the technique has been extended from a synchrotron light source to utilise a lab-based microfocus X-ray source and flat panel detector. Removing the need to raster the optics in two directions significantly reduces the acquisition time and absorbed dose, which can be of vital importance for many biological samples. This new imaging method could potentially provide a breakthrough for numerous practical imaging applications in biomedical research and materials science.
Leontidis, Georgios
2017-11-01
Human retina is a diverse and important tissue, vastly studied for various retinal and other diseases. Diabetic retinopathy (DR), a leading cause of blindness, is one of them. This work proposes a novel and complete framework for the accurate and robust extraction and analysis of a series of retinal vascular geometric features. It focuses on studying the registered bifurcations in successive years of progression from diabetes (no DR) to DR, in order to identify the vascular alterations. Retinal fundus images are utilised, and multiple experimental designs are employed. The framework includes various steps, such as image registration and segmentation, extraction of features, statistical analysis and classification models. Linear mixed models are utilised for making the statistical inferences, alongside the elastic-net logistic regression, boruta algorithm, and regularised random forests for the feature selection and classification phases, in order to evaluate the discriminative potential of the investigated features and also build classification models. A number of geometric features, such as the central retinal artery and vein equivalents, are found to differ significantly across the experiments and also have good discriminative potential. The classification systems yield promising results with the area under the curve values ranging from 0.821 to 0.968, across the four different investigated combinations. Copyright © 2017 Elsevier Ltd. All rights reserved.
Framework development for the assessment of interprofessional teamwork in mental health settings.
Tomizawa, Ryoko; Shigeta, Masahiro; Reeves, Scott
2017-01-01
In mental health settings, interprofessional practice is regarded as a comprehensive approach to prevent relapse and manage chronic conditions with practice of various teamwork interventions. To reinforce the potential of interprofessional teamwork, it is recommended that theories or conceptual frameworks be employed. There continues, however, to be a limited use of such approaches that assess the quality of interprofessional teamwork in mental health settings. This article aimed to present a new conceptual framework for the assessment of interprofessional teamwork based on the findings of a scoping review of the literature. This review was undertaken to identify conceptual frameworks utilised in interprofessional teamwork in mental health settings. After reviewing 952 articles, the methodological characteristics extracted from 12 articles were considered. The included studies were synthesised into the Donabedian structure-process-outcome model. The findings revealed that structural issues comprised three elements: professional characteristics, client-care characteristics, and contextual characteristics in organisations. Process issues comprised two elements: team mechanisms and community-oriented services. Finally, outcome issues comprised the following elements: clients' outcomes and professionals' outcomes. The review findings suggested possibilities for further development of how to assess the quality of interprofessional teamwork and provided information about what specific approach is required to improve interprofessional teamwork. Future research should utilise various areas and cultures to clarify the adaptation potential.
Simulations of Solar Wind Plasma Flow Around a Simple Solar Sail
NASA Technical Reports Server (NTRS)
Garrett, Henry B.; Wang, Joseph
2004-01-01
In recent years, a number of solar sail missions of various designs and sizes have been proposed (e.g., Geostorm). Of importance to these missions is the interaction between the ambient solar wind plasma environment and the sail. Assuming a typical 1 AU solar wind environment of 400 km/s velocity, 3.5 cu cm density, ion temperature of approx.10 eV, electron temperature of 40 eV, and an ambient magnetic field strength of 10(exp -4) G, a first order estimate of the plasma interaction with square solar sails on the order of the sizes being considered for a Geostorm mission (50 m x 50 m and 75 m x 75 m corresponding to approx.2 and approx.3 times the Debye length in the plasma) is carried out. First, a crude current balance for the sail surface immersed in the plasma environment and in sunlight was used to estimate the surface potential of the model sails. This gave surface potentials of approx.10 V positive relative to the solar wind plasma. A 3-D, Electrostatic Particle-in-Cell (PIC) code was then used to simulate the solar wind flowing around the solar sail. It is assumed in the code that the solar wind protons can be treated as particles while the electrons follow a Boltzmann distribution. Next, the electric field and particle trajectories are solved self-consistently to give the proton flow field, the electrostatic field around the sail, and the plasma density in 3-D. The model sail was found to be surrounded by a plasma sheath within which the potential is positive compared to the ambient plasma and followed by a separate plasma wake which is negative relative to the plasma. This structure departs dramatically from a negatively charged plate such as might be found in the Earth s ionosphere on the night side where both the plate and its negative wake are contiguous. The implications of these findings are discussed as they apply to the proposed Geostorm solar sail mission.
Impact of Solar Array Position on ISS Vehicle Charging
NASA Technical Reports Server (NTRS)
Alred, John; Mikatarian, Ronald; Koontz, Steve
2006-01-01
The International Space Station (ISS), because of its large structure and high voltage solar arrays, has a complex plasma interaction with the ionosphere in low Earth orbit (LEO). This interaction of the ISS US Segment photovoltaic (PV) power system with the LEO ionospheric plasma produces floating potentials on conducting elements of the ISS structure relative to the local plasma environment. To control the ISS floating potentials, two Plasma Contactor Units (PCUs) are installed on the Z1 truss. Each PCU discharges accumulated electrons from the Space Station structure, thus reducing the potential difference between the ISS structure and the surrounding charged plasma environment. Operations of the PCUs were intended to keep the ISS floating potential to 40 Volts (Reference 1). Exposed dielectric surfaces overlying conducting structure on the Space Station will collect an opposite charge from the ionosphere as the ISS charges. In theory, when an Extravehicular Activity (EVA) crewmember is tethered to structure via the crew safety tether or when metallic surfaces of the Extravehicular Mobility Unit (EMU) come in contact with conducting metallic surfaces of the ISS, the EMU conducting components, including the perspiration-soaked crewmember inside, can become charged to the Space Station floating potential. The concern is the potential dielectric breakdown of anodized aluminum surfaces on the EMU producing an arc from the EMU to the ambient plasma, or nearby ISS structure. If the EMU arcs, an electrical current of an unknown magnitude and duration may conduct through the EVA crewmember, producing an unacceptable condition. This electrical current may be sufficient to startle or fatally shock the EVA crewmember (Reference 2). Hence, as currently defined by the EVA community, the ISS floating potential for all nominal and contingency EVA worksites and translation paths must have a magnitude less than 40 volts relative to the local ionosphere at all times during EVA. Arcing from the EMU is classified as a catastrophic hazard, which requires two-failure tolerant controls, i.e., three hazard controls. Each PCU is capable of maintaining the ISS floating potential below the requirement during EVA. The two PCUs provide a single failure tolerant control of ISS floating potential. In the event of the failure of one or two PCUs, a combination of solar array shunting and turning the solar arrays into their own wakes will be used to supply control of the plasma hazard (Reference 3). The purpose of this paper is to present on-orbit information that shows that ISS solar array placement with respect to the ISS velocity vector can control solar array plasma charging, and hence, provide an operational control for the plasma hazard. Also, this paper will present on-orbit information that shows that shunting of the ISS solar arrays can control solar array plasma charging, and hence, provide an additional operational control for the plasma hazard.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Skowronski, P.; Wisniewski, G.
Application of solar energy for preparing domestic hot water is one of the easiest methods of utilization of this energy. At least part of the needs for warm tap water could be covered by solar systems. At present, mainly coal is used for water heating at dwellings in rural areas in Poland. Warm tap water consumption will increase significantly in the future as standards of living are improved. This can result in the growth of electricity use and an increase in primary fuel consumption. Present and future methods of warm sanitary water generation in rural areas in Poland is discussed,more » and associated greenhouse gas (GHG) emissions are estimated. It is predicted that the emission of CO{sub 2} and NOx will increase. The emission of CO and CH{sub 4} will decrease because of changes in the structure of the final energy carriers used. The economic and market potentials of solar energy for preparing warm water in rural areas are discussed. It is estimated that solar systems can meet 30%-45% of the energy demand for warm water generation in rural areas at a reasonable cost, with a corresponding CO{sub 2} emission reduction. The rate of realization of the economic potential of solar water heaters depends on subsidies for the installation of equipment. 13 refs., 9 tabs.« less
NASA Astrophysics Data System (ADS)
Alam, Rashidah Zainal; Siwar, Chamhuri; Ludin, Norasikin Ahmad
Malaysia's energy sector is highly dependent on fossil fuels as a primary energy source. Economic growth and socio-economic wellbeing also rely on the utilization of energy in daily life routine. Nevertheless, the increasing cost for electricity and declining fossil fuels resources causes various negative impacts to the people and environment especially in rural areas. This prompted Malaysia to shift towards alternative energy sources such as solar energy to ensure social, economic and environmental benefits. The solar energy is one of the potential renewable energy sources in tropical countries particularly in Malaysia. The paper attempts to analyze the benefits and advantages related to energy efficiency of solar for sustainable energy use and socio economic wellbeing in rural areas, Malaysia. The paper uses secondary sources of data such as policies, regulations and research reports from relevant ministries and agencies to attain the objectives. As a signatory country to the UN Convention on Climate Change and the Kyoto Protocol, Malaysia has taken initiatives for decreasing energy dependence on oil to reduce greenhouse gas emissions (GHG) for sustainable development. The paper shows solar energy becomes one of the promising alternative energy sources to alleviate energy poverty in Malaysia for rural areas. Finally, solar energy has increased socio-economic wellbeing and develops green potential and toward achieving energy efficiency in energy sector of Malaysia by preserving environment as well as reducing carbon emission.
A novel thiourea type organocatalyst possessing a single NH functionality.
Jovanovic, Predrag; Petkovic, Milos; Simic, Milena; Ivkovic, Branka; Savic, Vladimir
2016-07-12
A novel thiourea organocatalyst was rationally designed by altering a typical H-bonding pattern of thiourea derivatives and utilising the potential of the 3,5-bis(trifluoromethyl)phenyl motif to participate in the H-bond formation. This unique catalyst afforded the products of the α-amination and Michael reaction in excellent yields and with a high level of stereoselectivity. Although additional studies are necessary to establish the full potential of the catalyst and to broaden its application further, the presented results may indicate alternative routes for further exploration of the thiourea class of organocatalysts.
Correlation of ISS Electric Potential Variations with Mission Operations
NASA Technical Reports Server (NTRS)
Willis, Emily M.; Minow, Joseph I.; Parker, Linda Neergaard
2014-01-01
Orbiting approximately 400 km above the Earth, the International Space Station (ISS) is a unique research laboratory used to conduct ground-breaking science experiments in space. The ISS has eight Solar Array Wings (SAW), and each wing is 11.7 meters wide and 35.1 meters long. The SAWs are controlled individually to maximize power output, minimize stress to the ISS structure, and minimize interference with other ISS operations such as vehicle dockings and Extra-Vehicular Activities (EVA). The Solar Arrays are designed to operate at 160 Volts. These large, high power solar arrays are negatively grounded to the ISS and collect charged particles (predominately electrons) as they travel through the space plasma in the Earth's ionosphere. If not controlled, this collected charge causes floating potential variations which can result in arcing, causing injury to the crew during an EVA or damage to hardware [1]. The environmental catalysts for ISS floating potential variations include plasma density and temperature fluctuations and magnetic induction from the Earth's magnetic field. These alone are not enough to cause concern for ISS, but when they are coupled with the large positive potential on the solar arrays, floating potentials up to negative 95 Volts have been observed. Our goal is to differentiate the operationally induced fluctuations in floating potentials from the environmental causes. Differentiating will help to determine what charging can be controlled, and we can then design the proper operations controls for charge collection mitigation. Additionally, the knowledge of how high power solar arrays interact with the environment and what regulations or design techniques can be employed to minimize charging impacts can be applied to future programs.
Interaction of the geomagnetic field with northward interplanetary magnetic field
NASA Astrophysics Data System (ADS)
Bhattarai, Shree Krishna
The interaction of the solar wind with Earth's magnetic field causes the transfer of momentum and energy from the solar wind to geospace. The study of this interaction is gaining significance as our society is becoming more and more space based, due to which, predicting space weather has become more important. The solar wind interacts with the geomagnetic field primarily via two processes: viscous interaction and the magnetic reconnection. Both of these interactions result in the generation of an electric field in Earth's ionosphere. The overall topology and dynamics of the magnetosphere, as well as the electric field imposed on the ionosphere, vary with speed, density, and magnetic field orientation of the solar wind as well as the conductivity of the ionosphere. In this dissertation, I will examine the role of northward interplanetary magnetic field (IMF) and discuss the global topology of the magnetosphere and the interaction with the ionosphere using results obtained from the Lyon-Fedder-Mobarry (LFM) simulation. The electric potentials imposed on the ionosphere due to viscous interaction and magnetic reconnection are called the viscous and the reconnection potentials, respectively. A proxy to measure the overall effect of these potentials is to measure the cross polar potential (CPP). The CPP is defined as the difference between the maximum and the minimum of the potential in a given polar ionosphere. I will show results from the LFM simulation showing saturation of the CPP during periods with purely northward IMF of sufficiently large magnitude. I will further show that the viscous potential, which was assumed to be independent of IMF orientation until this work, is reduced during periods of northward IMF. Furthermore, I will also discuss the implications of these results for a simulation of an entire solar rotation.
Optimising Ambient Setting Bayer Derived Fly Ash Geopolymers
Jamieson, Evan; Kealley, Catherine S.; van Riessen, Arie; Hart, Robert D.
2016-01-01
The Bayer process utilises high concentrations of caustic and elevated temperature to liberate alumina from bauxite, for the production of aluminium and other chemicals. Within Australia, this process results in 40 million tonnes of mineral residues (Red mud) each year. Over the same period, the energy production sector will produce 14 million tonnes of coal combustion products (Fly ash). Both industrial residues require impoundment storage, yet combining some of these components can produce geopolymers, an alternative to cement. Geopolymers derived from Bayer liquor and fly ash have been made successfully with a compressive strength in excess of 40 MPa after oven curing. However, any product from these industries would require large volume applications with robust operational conditions to maximise utilisation. To facilitate potential unconfined large-scale production, Bayer derived fly ash geopolymers have been optimised to achieve ambient curing. Fly ash from two different power stations have been successfully trialled showing the versatility of the Bayer liquor-ash combination for making geopolymers. PMID:28773513
Optimising Ambient Setting Bayer Derived Fly Ash Geopolymers.
Jamieson, Evan; Kealley, Catherine S; van Riessen, Arie; Hart, Robert D
2016-05-19
The Bayer process utilises high concentrations of caustic and elevated temperature to liberate alumina from bauxite, for the production of aluminium and other chemicals. Within Australia, this process results in 40 million tonnes of mineral residues (Red mud) each year. Over the same period, the energy production sector will produce 14 million tonnes of coal combustion products (Fly ash). Both industrial residues require impoundment storage, yet combining some of these components can produce geopolymers, an alternative to cement. Geopolymers derived from Bayer liquor and fly ash have been made successfully with a compressive strength in excess of 40 MPa after oven curing. However, any product from these industries would require large volume applications with robust operational conditions to maximise utilisation. To facilitate potential unconfined large-scale production, Bayer derived fly ash geopolymers have been optimised to achieve ambient curing. Fly ash from two different power stations have been successfully trialled showing the versatility of the Bayer liquor-ash combination for making geopolymers.
Vecellio, Elia; Georgiou, Andrew; Toouli, George; Eigenstetter, Alex; Li, Ling; Wilson, Roger; Westbrook, Johanna I
2013-01-01
Electronic test ordering, via the Electronic Medical Record (EMR), which incorporates computerised provider order entry (CPOE), is widely considered as a useful tool to support appropriate pathology test ordering. Diagnosis-related groups (DRGs) are clinically meaningful categories that allow comparisons in pathology utilisation by patient groups by controlling for many potentially confounding variables. This study used DRG data linked to pathology test data to examine changes in rates of test ordering across four years coinciding with the introduction of an EMR in six hospitals in New South Wales, Australia. This method generated a list of high pathology utilisation DRGs. We investigated patients with a Chest pain DRG to examine whether tests rates changed for specific test groups by hospital emergency department (ED) pre- and post-EMR. There was little change in testing rates between EDs or between time periods pre- and post-EMR. This is a valuable method for monitoring the impact of EMR and clinical decision support on test order rates.
NASA Astrophysics Data System (ADS)
Morrison, Brandon; Golden, Jay S.
2018-02-01
Given increased policies driving renewable electricity generation and insufficient local production of woody biomass, many countries are reliant upon the importation of wood pellets. Of current wood pellet exports, the vast majority originates from the Southeastern United States (US). In this paper we present results from a cradle-to-gate, attributional process life cycle assessment in which two production scenarios of wood pellets were modelled for the Southeastern US: one utilising roundwood from a silviculture operation and the other utilising sawmill residues. The system boundary includes all steps from harvesting of the wood biomass, through delivery of the finished wood pellets to a US port facility. For each of the impact categories assessed, wood pellets from sawmill residues resulted in higher values, ranging from 5% to 31%. In relation to Global Warming Potential, roundwood pellets resulted in a 13-21% lower value than pellets produced from sawmill residues, depending upon the allocation method.
Involving consumers in health research: what do consumers say?
Todd, Angela L; Nutbeam, Don
2018-06-14
To ensure that the contribution of patients and consumers in health research is better understood, respected and fully utilised. Type of program or service: Consumer representative networks that form part of a broader quality improvement program in local health services. Consultations were held with members of health consumer networks in Sydney, Northern Sydney and Western Sydney Local Health Districts, and the Sydney Children's Hospitals Network (at Westmead) about how to better involve consumers in health research. Feedback from 20 volunteers suggested that consumer involvement in research would be improved if: consumers understood more about research; communications clearly explained the research, why it was relevant to consumers and what might be involved; consumers' contributions were heard and respected; and being involved in research was made an easy and positive experience. People want to be involved in health research, and have valuable contributions to make. We must ensure that the potential contribution of patients and consumers is fully utilised, and get a great deal better at communicating benefits and risks.
Feng, Yunzi; Chen, Zhiyao; Liu, Ning; Zhao, Haifeng; Cui, Chun; Zhao, Mouming
2014-09-01
Evolution of lipids during koji fermentation and the effect of lipase supplementation on the sensory properties of soy sauce were investigated. Results showed that total lipids of the koji samples were in the range of 16-21%. The extracted lipid of initial koji consisted mainly of triacylglycerols (TAGs, >98%), followed by phospholipids (PLs), diglycerides (DAGs), monoacylglycerols (MAGs) and free fatty acids (FFAs). As the fermentation proceeded, peroxide value of the lipids decreased while carbonyl value increased (p<0.05). Linoleic acid was utilised fastest according to the fatty acid composition of total lipids, and preferential degradation of PLs to liberate FFAs was also observed. Moreover, phospholipase supplementation had significant influence on the sensory characteristics of soy sauce, especially enhanced (p<0.05) scores for the umami and kokumi taste attributes. All these results indicated that the control of PLs utilisation during fermentation was a potential method to improve soy sauce's characteristic taste. Copyright © 2014 Elsevier Ltd. All rights reserved.
Raninen, Kaisa; Lappi, Jenni; Kolehmainen, Mikko; Kolehmainen, Marjukka; Mykkänen, Hannu; Poutanen, Kaisa; Raatikainen, Olavi
2017-12-01
The potential of utilising exhaled breath volatile organic compound (VOC) profiles in studying diet-derived metabolic changes was examined. After a four-week initial diet period with white wheat bread (WW), seven participants received in randomised order high-fibre diets containing sourdough whole grain rye bread (WGR) or white wheat bread enriched with bioprocessed rye bran (WW + BRB), both for 4 weeks. Alveolar exhaled breath samples were analysed with ChemPro ® 100i analyser (Environics OY, Mikkeli, Finland) at the end of each diet period in fasting state and after a standardised meal. The AIMS signal intensities in fasting state were different after the WGR diet as compared to other diets. The result suggests that WGR has metabolic effects not completely explained by the rye fibre content of the diet. This study encourages to utilise the exhaled breath VOC profile analysis as an early screening tool in studying physiological functionality of foods.
Inhibitor analysis for a solar heating and cooling system
NASA Technical Reports Server (NTRS)
Tabony, J. H.
1977-01-01
A study of potential corrosion inhibitors for the NASA solar heating and cooling system which uses aluminum solar panels is provided. Research consisted of testing using a dynamic corrosion system, along with an economic analysis of proposed corrosion inhibitors. Very good progress was made in finding a suitable inhibitor for the system.
76 FR 23198 - Segregation of Lands-Renewable Energy
Federal Register 2010, 2011, 2012, 2013, 2014
2011-04-26
... could be used to carry the power generated from a specific wind or solar energy ROW project, and the... included in a pending or future wind or solar energy generation right- of-way (ROW) application, or public lands identified by the BLM for a potential future wind or solar energy generation ROW authorization...
Going Solar Yields Long-Term Economical, Educational Benefits
ERIC Educational Resources Information Center
von Moos, Brian
2009-01-01
Going solar is not an easy decision, but a long-term investment with a potentially substantial up-front cost. While some schools have enough capital in reserve, can raise bond money, or can solicit sufficient donations, many schools rely on creative financial programs to make a solar energy system economically feasible. Thinking about going solar…
High-efficiency dye-sensitized solar cells with ferrocene-based electrolytes.
Daeneke, Torben; Kwon, Tae-Hyuk; Holmes, Andrew B; Duffy, Noel W; Bach, Udo; Spiccia, Leone
2011-03-01
Dye-sensitized solar cells based on iodide/triiodide (I(-)/I(3)(-)) electrolytes are viable low-cost alternatives to conventional silicon solar cells. However, as well as providing record efficiencies of up to 12.0%, the use of I(-)/I(3)(-) in such solar cells also brings about certain limitations that stem from its corrosive nature and complex two-electron redox chemistry. Alternative redox mediators have been investigated, but these generally fall well short of matching the performance of conventional I(-)/I(3)(-) electrolytes. Here, we report energy conversion efficiencies of 7.5% (simulated sunlight, AM1.5, 1,000 W m(-2)) for dye-sensitized solar cells combining the archetypal ferrocene/ferrocenium (Fc/Fc(+)) single-electron redox couple with a novel metal-free organic donor-acceptor sensitizer (Carbz-PAHTDTT). These Fc/Fc(+)-based devices exceed the efficiency achieved for devices prepared using I(-)/I(3)(-) electrolytes under comparable conditions, revealing the great potential of ferrocene-based electrolytes in future dye-sensitized solar cells applications. This improvement results from a more favourable matching of the redox potential of the ferrocene couple with that of the new donor-acceptor sensitizer.
Enhancing light absorption within the carrier transport length in quantum junction solar cells.
Fu, Yulan; Hara, Yukihiro; Miller, Christopher W; Lopez, Rene
2015-09-10
Colloidal quantum dot (CQD) solar cells have attracted tremendous attention because of their tunable absorption spectrum window and potentially low processing cost. Recently reported quantum junction solar cells represent a promising approach to building a rectifying photovoltaic device that employs CQD layers on each side of the p-n junction. However, the ultimate efficiency of CQD solar cells is still highly limited by their high trap state density in both p- and n-type CQDs. By modeling photonic structures to enhance the light absorption within the carrier transport length and by ensuring that the carrier generation and collection efficiencies were both augmented, our work shows that overall device current density could be improved. We utilized a two-dimensional numerical model to calculate the characteristics of patterned CQD solar cells based on a simple grating structure. Our calculation predicts a short circuit current density as high as 31 mA/cm2, a value nearly 1.5 times larger than that of the conventional flat design, showing the great potential value of patterned quantum junction solar cells.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
2014-09-01
Increasing demand for electric vehicle (EV) charging provides an opportunity for market expansion of distributed solar technology. A major barrier to the current deployment of solar technology for EV charging is a lack of clear information for policy makers, utilities and potential adopters. This paper introduces the pros and cons of EV charging during the day versus at night, summarizes the benefits and grid implications of combining solar and EV charging technologies, and offers some regulatory and policy options available to policy makers and regulators wanting to incentivize solar EV charging.
Drying of medicinal plants with solar energy utilization
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wisniewski, G.
In the paper, a potential of solar energy for drying of medicinal plants in Polish conditions is estimated and development of solar drying technologies is presented. The results of economic assessment of flat-plate solar collectors applied for drying of medicinal plants on a farm are promising. In some specific conditions, e.g. drying of wild grown medicinal plants in remote areas, even application of photovoltaic modules for driving of a fan of a solar dryer is a profitable option and enables easy control of the drying air temperature.
Space satellite power system. [conversion of solar energy by photovoltaic solar cell arrays
NASA Technical Reports Server (NTRS)
Glaser, P. E.
1974-01-01
The concept of a satellite solar power station was studied. It is shown that it offers the potential to meet a significant portion of future energy needs, is pollution free, and is sparing of irreplaceable earth resources. Solar energy is converted by photovoltaic solar cell arrays to dc energy which in turn is converted into microwave energy in a large active phased array. The microwave energy is beamed to earth with little attenuation and is converted back to dc energy on the earth. Economic factors are considered.
Exploration of the solar system
NASA Technical Reports Server (NTRS)
Henderson, A., Jr. (Editor); Grey, J.
1974-01-01
The potential achievements of solar system exploration are outlined, and a course of action is suggested which will maximize the rewards. Also provided is a sourcebook of information on the solar system and the technology being brought to bear for its exploration. The document explores the degree to which three practical questions can be answered: why it is necessary to explore the solar system, why understanding of the solar system is important to us, and why we cannot wait until all terrestrial problems are solved before an attempt is made to solve problems in space.
NASA Astrophysics Data System (ADS)
Bramstedt, Klaus; Stone, Thomas C.; Gottwald, Manfred; Noël, Stefan; Bovensmann, Heinrich; Burrows, John P.
2017-07-01
The SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) on Envisat (2002-2012) performed nadir, limb, solar/lunar occultation and various monitoring measurements. The pointing information of the instrument is determined by the attitude information of the Envisat platform with its star trackers together with the encoder readouts of both the azimuth and the elevation scanner of SCIAMACHY. In this work, we present additional sources of attitude information from the SCIAMACHY measurements itself. The basic principle is the same as used by the star tracker: we measure the viewing direction towards celestial objects, i.e. sun and moon, to detect possible mispointings. In sun over limb port observations, we utilise the vertical scans over the solar disk. In horizontal direction, SCIAMACHY's sun follower device (SFD) is used to adjust the viewing direction. Moon over limb port measurements use for both the vertical and the horizontal direction the adjustment by the SFD. The viewing direction is steered towards the intensity centroid of the illuminated part of the lunar disk. We use reference images from the USGS Robotic Lunar Observatory (ROLO) to take into account the inhomogeneous surface and the variations by lunar libration and phase to parameterise the location of the intensity centroid from the observation geometry. Solar observations through SCIAMACHY's so-called sub-solar port (with a viewing direction closely to zenith) also use the SFD in the vertical direction. In the horizontal direction the geometry of the port defines the viewing direction. Using these three type of measurements, we fit improved mispointing parameters by minimising the pointing offsets in elevation and azimuth. The geolocation of all retrieved products will benefit from this; the tangent heights are especially improved. The altitudes assigned to SCIAMACHY's solar occultation measurements are changed in the range of -130 to -330 m, the lunar occultation measurements are changed in the range of 0 to +130 m and the limb measurements are changed in the range of -50 to +60 m (depending on season, altitude and azimuth angle). The horizontal location of the tangent point is changed by about 5 km for all measurements. These updates are implemented in version 9 of the SCIAMACHY Level 1b products and Level 2 version 7 (based on L1b version 9).
Toward a High-Efficient Utilization of Solar Radiation by Quad-Band Solar Spectral Splitting.
Cao, Feng; Huang, Yi; Tang, Lu; Sun, Tianyi; Boriskina, Svetlana V; Chen, Gang; Ren, Zhifeng
2016-12-01
The promising quad-band solar spectral splitter incorporates the properties of the optical filter and the spectrally selective solar thermal absorber can direct PV band to PV modules and absorb thermal band energy for thermal process with low thermal losses. It provides a new strategy for spectral splitting and offers potential ways for hybrid PVT system design. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
How to Bring Solar Energy to Seven Billion People (LBNL Science at the Theater)
Wadia, Cyrus [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2018-05-24
By exploiting the powers of nanotechnology and taking advantage of non-toxic, Earth-abundant materials, Berkeley Lab's Cyrus Wadia has fabricated new solar cell devices that have the potential to be several orders of magnitude less expensive than conventional solar cells. And by mastering the chemistry of these materials-and the economics of solar energy-he envisions bringing electricity to the 1.2 billion people now living without it.
NASA Astrophysics Data System (ADS)
Munsat, Tobin; Deca, Jan; Han, Jia; Horanyi, Mihaly; Wang, Xu; Werner, Greg; Yeo, Li Hsia; Fuentes, Dominic
2017-10-01
Magnetic anomalies on the surfaces of airless bodies such as the Moon interact with the solar wind, resulting in both magnetic and electrostatic deflection of the charged particles and thus localized surface charging. This interaction is studied in the Colorado Solar Wind Experiment with large-cross-section ( 300 cm2) high-energy flowing plasmas (100-800 eV beam ions) that are incident upon a magnetic dipole embedded under various insulating surfaces. Measured 2D plasma potential profiles indicate that in the dipole lobe regions, the surfaces are charged to high positive potentials due to the collection of unmagnetized ions, while the electrons are magnetically shielded. At low ion beam energies, the surface potential follows the beam energy in eV. However, at high energies, the surface potentials in the electron-shielded regions are significantly lower than the beam energies. A series of studies indicate that secondary electrons are likely to play a dominant role in determining the surface potential. Early results will also be presented from a second experiment, in which a strong permanent magnet with large dipole moment (0.55 T, 275 A*m2) is inserted into the flowing plasma beam to replicate aspects of the solar wind interaction with the earth's magnetic field. This work is supported by the NASA SSERVI program.
The electric potential of particles in interstellar space released from a nuclear waste payload
NASA Technical Reports Server (NTRS)
Williams, A. C.
1980-01-01
Mechanisms for charging a grain in the interplanetary medium include: (1) capture of solar wind electrons; (2) capture of solar wind protons; (3) ejection of electrons through the photoelectric effect due to the solar radiation; (4) escape of beta particles from beta emitters in the grain; and (5) escape of alpha particles from alpha emitters in the grain. The potentials on both nonradioactive and radioactive grains are considered with relation to particle size and time, and the distance from the Sun. Numerical results are presented where the waste mix is assumed to be PW-4b.
Solar greenhouse workshop; video documentary
DOE Office of Scientific and Technical Information (OSTI.GOV)
Austin, B.; Devine B.; Taylor, C.
1980-01-01
A 38 minute video-tape documentary of the building of an attached solar greenhouse is presented. The tape follows the construction process from foundation preparation to greenhouse completion. The tape allows greater outreach to potential builders of solar greenhouses than a conventional construction workshop. It allows viewers to appreciate the simplicity of construction, and encourages, by example, interested people to start building. The process of making the documentary is briefly described, as are its potential uses. Copies of the video-tape are available, for the cost of the tape alone, from Antioch Video, Antioch College, Yellow Springs, Ohio 45387.
Potentials of storing solar energy in the form of hydrogen for Egypt
DOE Office of Scientific and Technical Information (OSTI.GOV)
Abdel, A.A.L.; Mohamed, M.A.
1989-01-01
A seemingly insatiable demand for energy characterizes Egypt as it approaches the end of the twentieth century. With the limited energy resources in the country, R and D to utilize renewable sources of energy is a must. This paper examines first the energy situation in Egypt and explores the potential of using solar energy in hydrogen production from water. Different schemes of dissociating water are reviewed next. Finally, research findings are reported for some experimental runs carried out for the electrolysis of water by solar energy, utilizing an eight-water photovoltaic cell (Telephonken type) to generate the DC current.
Radioisotope Reduction Using Solar Power for Outer Planetary Missions
NASA Technical Reports Server (NTRS)
Fincannon, James
2008-01-01
Radioisotope power systems have historically been (and still are) the power system of choice from a mass and size perspective for outer planetary missions. High demand for and limited availability of radioisotope fuel has made it necessary to investigate alternatives to this option. Low mass, high efficiency solar power systems have the potential for use at low outer planetary temperatures and illumination levels. This paper documents the impacts of using solar power systems instead of radioisotope power for all or part of the power needs of outer planetary spacecraft and illustrates the potential fuel savings of such an approach.
NASA Astrophysics Data System (ADS)
Freeman, J. W.
Aspects of solar power generation in space are considered. The subjects discussed include: a vision of future energy from space; solar power satellite concept for utilization of energy from space; the institutional challenge of solar power satellites; system study of the solar power satellite concept; market potential and possible limitations for satellite solar power stations; financing a solar power satellite project; and European questions related to satellite power systems. Also addressed are: options and high payoff choices for transportation; an electric propulsion transportation system from low-earth orbit to geostationary orbit utilizing beamed microwave power; the Canadarm robot arm of the Shuttle Remote Manipulator System; an early experimental solar power satellite; power economical considerations for the integration of terrestrial and extraterrestrial solar generators into existing power generation stations; and space solar power in perspective. For individual items see A84-21477 to A84-21489
Coronal magnetic fields and the solar wind
NASA Technical Reports Server (NTRS)
Newkirk, G., Jr.
1972-01-01
Current information is presented on coronal magnetic fields as they bear on problems of the solar wind. Both steady state fields and coronal transient events are considered. A brief critique is given of the methods of calculating coronal magnetic fields including the potential (current free) models, exact solutions for the solar wind and field interaction, and source surface models. These solutions are compared with the meager quantitative observations which are available at this time. Qualitative comparisons between the shapes of calculated magnetic field lines and the forms visible in the solar corona at several recent eclipses are displayed. These suggest that: (1) coronal streamers develop above extended magnetic arcades which connect unipolar regions of opposite polarity; and (2) loops, arches, and rays in the corona correspond to preferentially filled magnetic tubes in the approximately potential field.
Surface charging of a crater near lunar terminator
NASA Astrophysics Data System (ADS)
Anuar, A. K.
2017-05-01
Past lunar missions have shown the presence of dust particles in the lunar exosphere. These particles originate from lunar surface and are due to the charging of lunar surface by the solar wind and solar UV flux. Near the lunar terminator region, the low conductivity of the surface and small scale variations in surface topology could cause the surface to charge to different surface potentials. This paper simulates the variation of surface potential for a crater located in the lunar terminator regions using Spacecraft Plasma Interaction Software (SPIS). SPIS employs particle in cell method to simulate the motion of solar wind particles and photoelectrons. Lunar crater has been found to create mini-wake which affects both electron and ion density and causes small scale potential differences. Simulation results show potential difference of 300 V between sunlit area and shadowed area which creates suitable condition for dust levitation to occur.
Yang, Yang; Xu, Di; Wu, Qingyong; Diao, Peng
2016-01-01
Solar powered hydrogen evolution reaction (HER) is one of the key reactions in solar-to-chemical energy conversion. It is desirable to develop photocathodic materials that exhibit high activity toward photoelectrochemical (PEC) HER at more positive potentials because a higher potential means a lower overpotential for HER. In this work, the Cu2O/CuO bilayered composites were prepared by a facile method that involved an electrodeposition and a subsequent thermal oxidation. The resulting Cu2O/CuO bilayered composites exhibited a surprisingly high activity and good stability toward PEC HER, expecially at high potentials in alkaline solution. The photocurrent density for HER was 3.15 mA·cm−2 at the potential of 0.40 V vs. RHE, which was one of the two highest reported at the same potential on copper-oxide-based photocathode. The high photoactivity of the bilayered composite was ascribed to the following three advantages of the Cu2O/CuO heterojunction: (1) the broadened light absorption band that made more efficient use of solar energy, (2) the large space-charge-region potential that enabled a high efficiency for electron-hole separation, and (3) the high majority carrier density that ensured a faster charge transportation rate. This work reveals the potential of the Cu2O/CuO bilayered composite as a promising photocathodic material for solar water splitting. PMID:27748380
A tapered dielectric waveguide solar concentrator for a compound semiconductor photovoltaic cell.
Park, Minkyu; Oh, Kyunghwan; Kim, Jeong; Shin, Hyun Woo; Oh, Byung Du
2010-01-18
A novel tapered dielectric waveguide solar concentrator is proposed for compound semiconductor solar cells utilizing optical fiber preform. Its light collecting capability is numerically simulated and experimentally demonstrated for feasibility and potential assessments. Utilizing tapered shape of an optical fiber preform with a step-index profile, low loss guidance was enhanced and the limitation in the acceptance angle of solar radiation was alleviated by an order of magnitude. Using a solar simulator the device performances were experimentally investigated and discussed in terms of the photocurrent improvements. Total acceptance angle exceeding +/- 6 degrees was experimentally achieved sustaining a high solar flux.
The evolution of the Sun's birth cluster and the search for the solar siblings with Gaia
NASA Astrophysics Data System (ADS)
Martínez-Barbosa, C. A.; Brown, A. G. A.; Boekholt, T.; Portegies Zwart, S.; Antiche, E.; Antoja, T.
2016-03-01
We use self-consistent numerical simulations of the evolution and disruption of the Sun's birth cluster in the Milky Way potential to investigate the present-day phase-space distribution of the Sun's siblings. The simulations include the gravitational N-body forces within the cluster and the effects of stellar evolution on the cluster population. In addition, the gravitational forces due to the Milky Way potential are accounted for in a self-consistent manner. Our aim is to understand how the astrometric and radial velocity data from the Gaia mission can be used to pre-select solar sibling candidates. We vary the initial conditions of the Sun's birth cluster, as well as the parameters of the Galactic potential. In particular, we use different configurations and strengths of the bar and spiral arms. We show that the disruption time-scales of the cluster are insensitive to the details of the non-axisymmetric components of the Milky Way model and we make predictions, averaged over the different simulated possibilities, about the number of solar siblings that should appear in surveys such as Gaia or GALAH. We find a large variety of present-day phase-space distributions of solar siblings, which depend on the cluster initial conditions and the Milky Way model parameters. We show that nevertheless robust predictions can be made about the location of the solar siblings in the space of parallaxes (ϖ), proper motions (μ) and radial velocities (Vr). By calculating the ratio of the number of simulated solar siblings to that of the number of stars in a model Galactic disc, we find that this ratio is above 0.5 in the region given by: ϖ ≥ 5 mas, 4 ≤ μ ≤ 6 mas yr-1, and -2 ≤ Vr ≤ 0 km s-1. Selecting stars from this region should increase the probability of success in identifying solar siblings through follow-up observations. However the proposed pre-selection criterion is sensitive to our assumptions, in particular about the Galactic potential. Using a more realistic potential (e.g. including transient spiral structure and molecular clouds) would make the pre-selection of solar sibling candidates based on astrometric and radial velocity data very inefficient. This reinforces the need for large-scale surveys to determine precise astrophysical properties of stars, in particular their ages and chemical abundances, if we want to identify the solar family.
Arsenic detection in water: YPO{sub 4}:Eu{sup 3+} nanoparticles
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ghosh, Debasish; Luwang, Meitram Niraj, E-mail: mn.luwang@ncl.res.in; Academy of Scientific and Innovative Research
This work reports on the novel technique of detection of arsenic in aqueous solution utilising the luminescence properties of lanthanide doped nanomaterials. Eu{sup 3+} (5%) doped YPO{sub 4}nanorodswere utilised for the said experiment. Co-precipitation method was used for the synthesis of the materials and characterised them with different instrumental techniques like X-ray diffraction (XRD), Infra-red (IR), UV-absorption, scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence studies. This nanoparticle can adsorb both arsenic and arsenious acids. We studied the effect of arsenic adsorption on the luminescence behaviour of the nanoparticles. Arsenic acid enhanced the luminescencemore » intensity whereas arsenious acid quenched the luminescence. This luminescence enhancement or quenching is related with arsenic concentration. This relation of luminescence property with concentration of arsenic can be used to detect arsenic in industrial waste. - Graphical abstract: Novel technique of detection of Arsenic ion in aqueous solution utilising the luminescence properties of lanthanide doped nanomaterials. Potential application for detection of arsenic in drinking and industrial waste water. - Highlights: • Novel technique of detection of Arsenic in aqueous solution by YPO{sub 4}:Eu{sup 3+} nanomaterials. • The effect of arsenic adsorption on the luminescence behaviour of the nanoparticles was studied. • Arsenic acid enhance whereas arsenious acid quenches the luminescence intensity. • This technique can be used to detect arsenic in industrial waste.« less
A hierarchical detection method in external communication for self-driving vehicles based on TDMA.
Alheeti, Khattab M Ali; Al-Ani, Muzhir Shaban; McDonald-Maier, Klaus
2018-01-01
Security is considered a major challenge for self-driving and semi self-driving vehicles. These vehicles depend heavily on communications to predict and sense their external environment used in their motion. They use a type of ad hoc network termed Vehicular ad hoc networks (VANETs). Unfortunately, VANETs are potentially exposed to many attacks on network and application level. This paper, proposes a new intrusion detection system to protect the communication system of self-driving cars; utilising a combination of hierarchical models based on clusters and log parameters. This security system is designed to detect Sybil and Wormhole attacks in highway usage scenarios. It is based on clusters, utilising Time Division Multiple Access (TDMA) to overcome some of the obstacles of VANETs such as high density, high mobility and bandwidth limitations in exchanging messages. This makes the security system more efficient, accurate and capable of real time detection and quick in identification of malicious behaviour in VANETs. In this scheme, each vehicle log calculates and stores different parameter values after receiving the cooperative awareness messages from nearby vehicles. The vehicles exchange their log data and determine the difference between the parameters, which is utilised to detect Sybil attacks and Wormhole attacks. In order to realize efficient and effective intrusion detection system, we use the well-known network simulator (ns-2) to verify the performance of the security system. Simulation results indicate that the security system can achieve high detection rates and effectively detect anomalies with low rate of false alarms.
Famiani, Franco; Farinelli, Daniela; Moscatello, Stefano; Battistelli, Alberto; Leegood, Richard C; Walker, Robert P
2016-04-01
The first aim of this study was to determine the contribution of stored malate and citrate to the substrate requirements of metabolism in the ripening flesh of the peach (Prunus persica L. Batsch) cultivar Adriatica. In the flesh, stored malate accumulated before ripening could contribute little or nothing to the net substrate requirements of metabolism. This was because there was synthesis and not dissimilation of malate throughout ripening. Stored citrate could potentially contribute a very small amount (about 5.8%) of the substrate required by metabolism when the whole ripening period was considered, and a maximum of about 7.5% over the latter part of ripening. The second aim of this study was to investigate why phosphoenolpyruvate carboxykinase (PEPCK) an enzyme utilised in gluconeogenesis from malate and citrate is present in peach flesh. The occurrence and localisation of enzymes utilised in the metabolism of malate, citrate and amino acids were determined in peach flesh throughout its development. Phosphoenolpyruvate carboxylase (essential for the synthesis of malate and citrate) was present in the same cells and at the same time as PEPCK and NADP-malic enzyme (both utilised in the dissimilation of malate and citrate). A hypothesis is presented to explain the presence of these enzymes and to account for the likely occurrence of gluconeogenesis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Irvine, Peter J.; Kravitz, Ben; Lawrence, Mark G.
Solar geoengineering has been proposed as a means to cool the planet by increasing the reflection of sunlight back to space, for example by injecting reflective aerosol particles into the middle atmosphere. Such proposals are not able to physically substitute for mitigation of greenhouse gas emissions as a response to the risks of climate change, but might eventually be applied as a complementary approach to reduce climate risks. Thus, the Earth system consequences of solar geoengineering are central to understanding its potentials and risks. Here we review the state-of-the-art knowledge about geoengineering by stratospheric sulphate aerosol injection. We examine themore » common responses found in studies of an idealized form of solar geoengineering, in which the intensity of incoming sunlight is directly reduced in models. The studies reviewed are consistent in suggesting that solar geoengineering would generally reduce the differences in climate in comparison to future scenarios with elevated greenhouse gas concentrations and no solar geoengineering. However, it is clear that a solar geoengineered climate would be novel in some respects, for example a notable reduction in the intensity of the hydrological cycle. We provide an overview of the unique aspects of the response to stratospheric aerosol injection and the uncertainties around its consequences. We also consider the issues raised by the partial control over the climate that solar geoengineering would allow. Finally, this overview also highlights the key research gaps that will need to be resolved in order to effectively guide future decisions on the potential use of solar geoengineering.« less
Solar Energy within the Central Valley, CA: Current Practices and Potential
NASA Astrophysics Data System (ADS)
Hoffacker, M. K.; Hernandez, R. R.; Allen, M. F.
2015-12-01
Utility-scale solar energy (USSE, ≥ 1 megawatt [MW]) systems are rapidly being deployed in the Central Valley of California, generating clean electricity and new job opportunities. Utility-scale solar energy systems require substantial quantities of land or space, often prompting an evaluation of environmental impacts and trade-offs when selecting their placement. Utilizing salt-contaminated agricultural land (as the sodium absorption and electrical conductivity values are unsuitably high), unsuitable for food production, and lands within the built environment (developed), can serve as a co-benefit opportunity when reclamation of these lands for USSE development is prioritized. In this study, we quantify the theoretical and generation-based solar energy potential for the Central Valley according to land-cover type, crop type, and for salt-contaminated lands. Further, we utilize the Carnegie Energy and Environmental Compatibility (CEEC) model to identify and prioritize solar energy, integrating environmental resource opportunities and constraints most relevant to the Central Valley. We use the CEEC model to generate a value-based environmental compatibility output for the Central Valley. The Central Valley extends across nearly 60,000 km2 of California with the potential of generating 21,800 - 30,300 TWh y-1 and 41,600 TWh y-1 of solar energy for photovoltaic (PV) and concentrating solar power (CSP), respectively. Pasture, hay, and cultivated crops comprise over half of the Central Valley, much of which is considered prime agriculture or of statewide or local importance for farming (28,200 km2). Together, approximately one-third of this region is salt-contaminated (16%) or developed (11%). This confers a generation-based potential of 5713 - 7891 TWh y-1 and 2770 TWh y-1 for PV and CSP, respectively. As energy, food, and land are inextricably linked, our study shows how land favorable for renewable energy systems can be used more effectively in places where land is premium.
Socioeconomic inequalities in health care utilisation in Norway: the population-based HUNT3 survey.
Vikum, Eirik; Krokstad, Steinar; Westin, Steinar
2012-08-22
In this study we investigated the distribution of self-reported health care utilisation by education and household income in a county population in Norway, in a universal public health care system based on ideals of equal access for all according to need, and not according to wealth. The study included 24,147 women and 20,608 men aged 20 years and above in the third Nord-Trøndelag Health Survey (HUNT 3) of 2006-2008. Income-related horizontal inequity was estimated through concentration indexes, and inequity by both education and income was estimated as risk ratios through conventional regression. We found no overall pro-rich or pro-educated socioeconomic gradient in needs-adjusted utilisation of general practitioner or inpatient care. However, we found overall pro-rich and pro-educated inequity in utilisation of both private medical specialists and hospital outpatient care. For these services there were large differences in levels of inequity between younger and older men and women. In contrast with recent studies from Norway, we found pro-rich and pro-educated social inequalities in utilisation of hospital outpatient services and not only private medical specialists. Utilisation of general practitioner and inpatient services, which have low access threshold or are free of charge, we found to be equitable.
Selan, S; Hellström, A; Fagerström, C
2016-02-01
To describe three-year trends in nutritional status and sleep quality and their impact on hospital utilisation in the oldest old (80 +) with heart failure (HF). Single-centred longitudinal observational study. South-eastern Sweden. 90 elderly (80+) with objectively verified HF. Baseline data from the Mini Nutritional Assessment (MNA) and on sleep quality were collected through structured interviews following the HF diagnosis (n=90) and at a three-year follow-up (n=41). Data on hospital utilisation during the three years following the HF diagnosis were also collected. Nineteen percent of the participants were found to have impaired nutritional status, a condition that increased hospital utilisation by four bed days per year. A majority (85%) had impaired sleep quality, but no impact on hospital utilisation was found. Nutritional status and sleep quality were stable over the three-year period. In the oldest old with HF, impaired nutritional status and impaired sleep quality are already common at HF diagnosis. Impaired nutritional status increases hospital utilisation significantly. Therefore, it is of supreme importance to systematically evaluate nutritional status and sleep quality in the oldest old when they are diagnosed with HF, as well as to take action if impairments are present.
Siting Solar Photovoltaics at Airports: Preprint
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kandt, A.; Romero, R.
2014-06-01
Airports present a significant opportunity for hosting solar technologies due to their open land; based on a 2010 Federal Aviation Administration study, the US Department of Agriculture, and the US Fish and Wildlife Service, there's potential for 116,704 MW of solar photovoltaics (PV) on idle lands at US airports. PV has a low profile and likely low to no impact on flight operations. This paper outlines guidance for implementing solar technologies at airports and airfields, focusing largely on the Federal Aviation Administration's policies. The paper also details best practices for siting solar at airports, provides information on the Solar Glaremore » Hazard Analysis Tool, and highlights a case study example where solar has been installed at an airport.« less
Banking on Solar: An Analysis of Banking Opportunities in the U.S. Distributed Photovoltaic Market
DOE Office of Scientific and Technical Information (OSTI.GOV)
Feldman, D.; Lowder, T.
This report provides a high-level overview of the developing U.S. solar loan product landscape, from both a market and economic perspective. It covers current and potential U.S. solar lending institutions; currently available loan products; loan program structures and post-loan origination options; risks and uncertainties of the solar asset class as it pertains to lenders; and an economic analysis comparing loan products to third party-financed systems in California.
Fleming, Austin; Folsom, Charles; Ban, Heng; ...
2015-11-13
Concentrating solar power (CSP) with thermal energy storage has potential to provide grid-scale, on-demand, dispatachable renewable energy. As higher solar receiver output temperatures are necessary for higher thermal cycle efficiency, current CSP research is focused on high outlet temperature and high efficiency receivers. Here, the objective of this study is to provide a simplified model to analyze the thermal efficiency of multi-cavity concentrating solar power receivers.
In-Space Transportation for Geo Space Solar Satellites
NASA Technical Reports Server (NTRS)
Martin, James A.; Donahue, Benjamin B.; Lawrence, Schuyler C.; McClanahan, James A.; Carrington, Connie (Technical Monitor)
2000-01-01
Space solar power satellites have the potential to provide abundant quantities of electricity for use on Earth. One concept, the Sun Tower, can be assembled in geostationary orbit from pieces transferred from Earth. The cost of transportation from Earth is one of the major hurdles to space solar power. This study found that a two-stage rocket launch vehicle with autonomous solar-electric transfer can provide the transportation at prices close to the goal of $800/kg
Solar thermal program summary. Volume 1: Overview, fiscal year 1988
NASA Astrophysics Data System (ADS)
1989-02-01
The goal of the solar thermal program is to improve overall solar thermal systems performance and provide cost-effective energy options that are strategically secure and environmentally benign. Major research activities include energy collection technology, energy conversion technology, and systems and applications technology for both CR and DR systems. This research is being conducted through research laboratories in close coordination with the solar thermal industry, utilities companies, and universities. The Solar Thermal Technology Program is pursuing the development of critical components and subsystems for improved energy collection and conversion devices. This development follows two basic paths: for CR systems, critical components include stretched membrane heliostats, direct absorption receivers (DARs), and transport subsystems for molten salt heat transfer fluids. These components offer the potential for a significant reduction in system costs; and for DR systems, critical components include stretched membrane dishes, reflux receivers, and Stirling engines. These components will significantly increase system reliability and efficiency, which will reduce costs. The major thrust of the program is to provide electric power. However, there is an increasing interest in the use of concentrated solar energy for applications such as detoxifying hazardous wastes and developing high-value transportable fuels. These potential uses of highly concentrated solar energy still require additional experiments to prove concept feasibility. The program goal of economically competitive energy reduction from solar thermal systems is being cooperatively addressed by industry and government.
NASA Astrophysics Data System (ADS)
Hinkley, James T.; McNaughton, Robbie K.; Pye, John; Saw, Woei; Stechel, Ellen B.
2016-05-01
Reforming of methane is practiced on a vast scale globally for the production of syngas as a precursor for the production of many commodities, including hydrogen, ammonia and synthetic liquid fuels. Solar reforming can reduce the greenhouse gas intensity of syngas production by up to about 40% by using solar thermal energy to provide the endothermic heat of reaction, traditionally supplied by combustion of some of the feed. This has the potential to enable the production of solar derived synthetic fuels as drop in replacements for conventional fuels with significantly lower CO2 intensity than conventional gas to liquids (GTL) processes. However, the intermittent nature of the solar resource - both diurnal and seasonal - poses significant challenges for such a concept, which relies on synthesis processes that typically run continuously on very stable feed compositions. We find that the integration of solar syngas production to a GTL process is a non-trivial exercise, with the ability to turn down the capacity of the GTL synthesis section, and indeed to suspend operations for short periods without significant detriment to product quality or process operability, likely to be a key driver for the commercial implementation of solar liquid fuels. Projected costs for liquid fuel synthesis suggest that solar reforming and small scale gas to liquid synthesis can potentially compete with conventional oil derived transport fuels in the short to medium term.
NASA Astrophysics Data System (ADS)
Wedemeyer, Sven
2018-04-01
The continuum intensity at millimeter wavelengths can serve as an essentially linear thermometer of the plasma in a thin layer in the atmosphere of the Sun, whereas the polarisation of the received radiation is a measure for the longitudinal magnetic field component in the same layer. The enormous leap in terms of spatial resolution with the Atacama Large Millimeter/submillimeter Array (ALMA) now makes it possible to observe the intricate fine-structure of the solar atmosphere at sufficiently high spatial, temporal, and spectral resolution, thus enabling studies of a wide range of scientific topics in solar physics that had been inaccessible at millimeter wavelengths before. The radiation observed by ALMA originates mostly from the chromosphere - a complex and dynamic layer between the photosphere and corona, which plays a crucial role in the transport of energy and matter and, ultimately, the heating of the outer solar atmosphere. ALMA observations of the solar chromosphere, which are offered as a regular capability since 2016, therefore have the potential to make important contributions towards the solution of fundamental questions in solar physics with implications for our understanding of stars in general. In this presentation, I will give a short description of ALMA's solar observing mode, it challenges and opportunities, and selected science cases in combination with numerical simulations and coordinated observations at other wavelengths. ALMA's scientific potential for studying the dynamic small-scale pattern of the solar chromosphere is illustrated with first results from Cycle 4.
Trends of CT utilisation in an emergency department in Taiwan: a 5-year retrospective study
Hu, Sung-Yuan; Hsieh, Ming-Shun; Lin, Meng-Yu; Hsu, Chiann-Yi; Lin, Tzu-Chieh; How, Chorng-Kuang; Wang, Chen-Yu; Tsai, Jeffrey Che-Hung; Wu, Yu-Hui; Chang, Yan-Zin
2016-01-01
Objectives To investigate the association between the trends of CT utilisation in an emergency department (ED) and changes in clinical imaging practice and patients' disposition. Setting A hospital-based retrospective observational study of a public 1520-bed referral medical centre in Taiwan. Participants Adult ED visits (aged ≥18 years) during 2009–2013, with or without receiving CT, were enrolled as the study participants. Main outcome measures For all enrolled ED visits, we retrospectively analysed: (1) demographic characteristics, (2) triage categories, (3) whether CT was performed and the type of CT scan, (4) further ED disposition, (5) ED cost and (6) ED length of stay. Results In all, 269 239 adult ED visits (148 613 male patients and 120 626 female patients) were collected during the 5-year study period, comprising 38 609 CT scans. CT utilisation increased from 11.10% in 2009 to 17.70% in 2013 (trend test, p<0.001). Four in 5 types of CT scan (head, chest, abdomen and miscellaneous) were increasingly utilised during the study period. Also, CT was increasingly ordered annually in all age groups. Although ED CT utilisation rates increased markedly, the annual ED visits did not actually increase. Moreover, the subsequent admission rate, after receiving ED CT, declined (59.9% in 2009 to 48.2% in 2013). Conclusions ED CT utilisation rates increased significantly during 2009–2013. Emergency physicians may be using CT for non-emergent studies in the ED. Further investigation is needed to determine whether increasing CT utilisation is efficient and cost-effective. PMID:27279477
COPD: Health Care Utilisation Patterns with Different Disease Management Interventions.
Luk, Edwin K; Hutchinson, Anastasia F; Tacey, Mark; Irving, Louis; Khan, Fary
2017-08-01
The management of COPD is a significant and costly issue worldwide, with acute healthcare utilisation consisting of admissions and outpatient attendances being a major contributor to the cost. Pulmonary rehabilitation (PR) and integrated disease management (IDM) are often offered. Whilst there is strong evidence of physical and quality of life outcomes following IDM and PR, few studies have looked into healthcare utilisation. The aims of this study were to confirm whether IDM and PR reduce acute healthcare utilisation and to identify factors which contribute to acute health care utilisation or increased mortality. This was a retrospective cohort study of patients with COPD who were referred to IDM over a 10-year period. Patients were also offered an 8-week PR program. Data collected were matched with the hospital dataset to obtain information on inpatient, ED and outpatient attendances. 517 patients were enrolled to IDM. 315 (61%) also commenced PR and 220 (43%) completed PR. Patients who were referred to PR were younger and had less comorbidities (p < 0.001). Both groups (IDM only and IDM + PR referred) had reductions in healthcare utilisation but the IDM-only group had greater reductions. A survival benefit (HR 0.68, 95% CI 0.50-0.92) was seen in those who were PR completers compared to patients who received IDM only. Patients with COPD who successfully complete PR in addition to participating in IDM have improved survival. IDM alone was effective in the reduction of healthcare utilisation; however, the addition of PR did not reduce healthcare usage further.
Baker, Amanj; Chen, Li-Chia; Elliott, Rachel A; Godman, Brian
2015-09-10
In April/2009, the UK National Health Service initiated four Better Care Better Value (BCBV) prescribing indicators, one of which encouraged the prescribing of cheaper angiotensin-converting enzyme inhibitors (ACEIs) instead of expensive angiotensin receptor blockers (ARBs), with 80 % ACEIs/20 % ARBs as a proposed, and achievable target. The policy was intended to save costs without affecting patient outcomes. However, little is known about the actual impact of the BCBV indicator on ACEIs/ARBs utilisation and cost-savings. Therefore, this study aimed to evaluate the impact of BCBV policy on ACEIs/ARBs utilisation and cost-savings, including exploration of regional variations of the policy's impact. This cross-sectional study used data from the UK Clinical Practice Research Datalink. Segmented time-series analysis was applied to monthly ACEIs prescription proportion, adjusted number of ACEIs/ARBs prescriptions and costs. Overall, the proportion of ACEIs prescription decreased during the study period from 71.2% in April/2006 to 70.7% in March/2012, with a small but a statistically significant pre-policy reduction in its monthly trend of 0.02% (p < 0.001). Instantly after its initiation, the policy was associated with a sudden reduction in the proportion of ACEIs prescription; however, it resulted in a statistically significant increase in the post-policy monthly trend of ACEIs prescription proportion of 0.013% (p < 0.001), resulting in an overall post-policy slope of -0.007%. Despite this post-policy induced increment, the policy failed to achieve the 80% target, which resulted in missing a potential cost-saving opportunity. The pre-policy trend of the adjusted number of ACEIs/ARBs prescriptions was increasing; however, their trends declined after the policy implementation. The policy affected neither total ACEIs/ARBs cost nor individual ACEIs or ARBs costs. ACEIs/ARBs utilisation was not affected by the BCBV policy. The small increase in post-policy ACEIs prescription proportion was not associated with any savings. This study represents a case study of a failed or ineffective policy and thus provides key learning lessons for other healthcare authorities. Given the existing opportunity of potential cost-savings from achieving the 80 % target, specific measures would be needed to enhance the policy implementation and uptake; however, this must be balanced against other cost-saving policies in other high-priority areas.
VizieR Online Data Catalog: Solar activity reconstructed for 3 millennia (Usoskin+, 2014)
NASA Astrophysics Data System (ADS)
Usoskin, I. G.; Hulot, G.; Gallet, Y.; Roth, R.; Licht, A.; Joos, F.; Kovaltsov, G. A.; Thebault, E.; Khokhlov, A.
2014-02-01
Indices of solar activity reconstructed from 14C using the m used in the paper. Two indices are provided - the sunspot number and the cosmic ray modulation potential, both with the 95% confidence intervals. The data sets are provided with decadal resolution, thus the individual solar cycles are not resolved. (2 data files).
New Solar Cell Is More Efficient, Less Costly | News | NREL
rules for solar cells. Credit: Dennis Schroeder American innovators still have some cards to play when significant cost advantage when it comes to high-volume manufacturing. "It's a potentially disruptive . solar manufacturing when the approach hits the assembly line next year. The innovative design, simple
2000-09-18
An engineer at AeroVironment's Design Development Center in Simi Valley, California, closely inspects a set of silicon solar cells for potential defects. The cells, fabricated by SunPower, Inc., of Sunnyvale, California, are among 64,000 solar cells which have been installed on the Helios Prototype solar-powered aircraft to provide power to its 14 electric motors and operating systems.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-13
...--Agua Caliente Solar Energy Zone in Yuma County, AZ AGENCY: Bureau of Land Management, Interior. ACTION... of protecting potential sites for future solar energy development while they are being analyzed in... public lands corresponds with the analysis of these same public lands as a proposed Solar Energy Zone...
Review of thin film solar cell technology and applications for ultra-light spacecraft solar arrays
NASA Technical Reports Server (NTRS)
Landis, Geoffrey A.
1991-01-01
Developments in thin-film amorphous and polycrystalline photovoltaic cells are reviewed and discussed with a view to potential applications in space. Two important figures of merit are discussed: efficiency (i.e., what fraction of the incident solar energy is converted to electricity), and specific power (power to weight ratio).
High efficiency silicon solar cell based on asymmetric nanowire.
Ko, Myung-Dong; Rim, Taiuk; Kim, Kihyun; Meyyappan, M; Baek, Chang-Ki
2015-07-08
Improving the efficiency of solar cells through novel materials and devices is critical to realize the full potential of solar energy to meet the growing worldwide energy demands. We present here a highly efficient radial p-n junction silicon solar cell using an asymmetric nanowire structure with a shorter bottom core diameter than at the top. A maximum short circuit current density of 27.5 mA/cm(2) and an efficiency of 7.53% were realized without anti-reflection coating. Changing the silicon nanowire (SiNW) structure from conventional symmetric to asymmetric nature improves the efficiency due to increased short circuit current density. From numerical simulation and measurement of the optical characteristics, the total reflection on the sidewalls is seen to increase the light trapping path and charge carrier generation in the radial junction of the asymmetric SiNW, yielding high external quantum efficiency and short circuit current density. The proposed asymmetric structure has great potential to effectively improve the efficiency of the SiNW solar cells.
Optimal Solar PV Arrays Integration for Distributed Generation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Omitaomu, Olufemi A; Li, Xueping
2012-01-01
Solar photovoltaic (PV) systems hold great potential for distributed energy generation by installing PV panels on rooftops of residential and commercial buildings. Yet challenges arise along with the variability and non-dispatchability of the PV systems that affect the stability of the grid and the economics of the PV system. This paper investigates the integration of PV arrays for distributed generation applications by identifying a combination of buildings that will maximize solar energy output and minimize system variability. Particularly, we propose mean-variance optimization models to choose suitable rooftops for PV integration based on Markowitz mean-variance portfolio selection model. We further introducemore » quantity and cardinality constraints to result in a mixed integer quadratic programming problem. Case studies based on real data are presented. An efficient frontier is obtained for sample data that allows decision makers to choose a desired solar energy generation level with a comfortable variability tolerance level. Sensitivity analysis is conducted to show the tradeoffs between solar PV energy generation potential and variability.« less
Simulation of hybrid solar power plants
NASA Astrophysics Data System (ADS)
Dieckmann, Simon; Dersch, Jürgen
2017-06-01
Hybrid solar power plants have the potential to combine advantages of two different technologies at the cost of increased complexity. The present paper shows the potential of the software greenius for the techno-economic evaluation of hybrid solar power plants and discusses two exemplary scenarios. Depreciated Concentrated Solar Power (CSP) plants based on trough technology can be retrofitted with solar towers in order to reach higher steam cycle temperatures and hence efficiencies. Compared to a newly built tower plant the hybridization of a depreciated trough plant causes about 30% lower LCOE reaching 104 /MWh. The second hybrid scenario combines cost-efficient photovoltaics with dispatchable CSP technology. This hybrid plant offers very high capacity factors up to 69% based on 100% load from 8am to 11pm. The LCOE of the hybrid plant are only slightly lower (174 vs. 186 /MWh) compared to the pure CSP plant because the capital expenditure for thermal storage and power block remains the same while the electricity output is much lower.
Cosmogenic 36Cl in karst waters: Quantifying contributions from atmospheric and bedrock sources
NASA Astrophysics Data System (ADS)
Johnston, V. E.; McDermott, F.
2009-12-01
Improved reconstructions of cosmogenic isotope production through time are crucial to understand past solar variability. As a preliminary step to derive atmospheric 36Cl/Cl solar proxy time-series from speleothems, we quantify 36Cl sources in cave dripwaters. Atmospheric 36Cl fallout rates are a potential proxy for solar output; however extraneous 36Cl derived from in-situ production in cave host-rocks could complicate the solar signal. Results from numerical modeling and preliminary geochemical data presented here show that the atmospheric 36Cl source dominates in many, but not all cave dripwaters. At favorable low elevation, mid-latitude sites, 36Cl based speleothem solar irradiance reconstructions could extend back to 500 ka, with a possible centennial scale temporal resolution. This would represent a marginal improvement in resolution compared with existing polar ice core records, with the added advantages of a wider geographic range, independent U-series constrained chronology, and the potential for contemporaneous climate signals within the same speleothem material.
Solar Seismology from Space. a Conference at Snowmass, Colorado
NASA Technical Reports Server (NTRS)
Ulrich, R. K.; Harvey, J.; Rhodes, E. J., Jr.; Toomre, J.
1984-01-01
The quality of the ground based observing environment suffers from several degrading factors: diurnal interruptions and thermal variations, atmospheric seeing and transparency fluctuations and adverse weather interruptions are among the chief difficulties. The limited fraction of the solar surface observable from only one vantage point is also a potential limitation to the quality of the data available without going to space. Primary conference goals were to discuss in depth the scientific return from current observations and analyses of solar oscillations, to discuss the instrumental and site requirements for realizing the full potential of the seismic analysis method, and to help bring new workers into the field by collecting and summarizing the key background theory. At the conclusion of the conference there was a clear consensus that ground based observation would not be able to provide data of the quality required to permit a substantial analysis of the solar convection zone dynamics or to permit a full deduction of the solar interior structure.
High-latitude spacecraft charging in low-Earth polar orbit
NASA Astrophysics Data System (ADS)
Frooninckx, Thomas B.
Spacecraft charging within the upper ionosphere is commonly thought to be insignificant and thus has received little attention. Recent experimental evidence has shown that electric potential differences as severe as 680 volts can develop between Defense Meteorological Satellite Program (DMSP) polar-orbiting (840 kilometers) spacecraft and their high-latitude environment. To explore space vehicle charging in this region more fully, an analysis was performed using DMSP F6, F7, F8, and F9 satellite precipitating particle and ambient plasma measurements taken during the winters of 1986-87 (solar minimum) and 1989-90 (solar maximum). An extreme solar cycle dependence was discovered as charging occurred more frequently and with greater severity during the period of solar minimum. One hundred seventy charging events ranging from -46 to 1,430 volts were identified, and satellite measurements and Time Dependent Ionospheric Model (TDIM) output were used to characterize the environments which generated and inhibited these potentials. All current sources were considered to determine the cause of the solar cycle dependence.
Derancourt, C; Bourdon-Lanoy, E; Grob, J-J; Guillaume, J-C; Bernard, P; Bastuji-Garin, S
2007-01-01
Multiple solar lentigos commonly seen on the upper back and shoulders of adults are classically considered as a sign of photodamage, although epidemiological studies are scarce. To assess whether these lesions are clinical markers of past severe sunburn. A case-control study in two outpatient dermatology clinics in French university hospitals. Past episodes of moderate and severe sunburn were compared between 145 adult patients with multiple solar lentigos on the upper back and 145 matched controls. In multivariate analysis adjusted for potential confounders, recalled episodes of sunburn during childhood, adolescence and adulthood were independently associated with the presence of multiple solar lentigos (adjusted odds ratios, 95% confidence intervals: 2.3 (1.1-5.2) and 28.1 (10.4-75.6) for moderate and severe sunburn, respectively). Multiple solar lentigos on the upper back and shoulders of adults are potential clinical markers of past severe sunburn which may thus be used to identify a population at higher risk of developing cutaneous malignant melanoma.
Jacob, S A; Ng, W L; Do, V
2015-02-01
There is wide variation in the proportion of newly diagnosed cancer patients who receive chemotherapy, indicating the need for a benchmark rate of chemotherapy utilisation. This study describes an evidence-based model that estimates the proportion of new cancer patients in whom chemotherapy is indicated at least once (defined as the optimal chemotherapy utilisation rate). The optimal chemotherapy utilisation rate can act as a benchmark for measuring and improving the quality of care. Models of optimal chemotherapy utilisation were constructed for each cancer site based on indications for chemotherapy identified from evidence-based treatment guidelines. Data on the proportion of patient- and tumour-related attributes for which chemotherapy was indicated were obtained, using population-based data where possible. Treatment indications and epidemiological data were merged to calculate the optimal chemotherapy utilisation rate. Monte Carlo simulations and sensitivity analyses were used to assess the effect of controversial chemotherapy indications and variations in epidemiological data on our model. Chemotherapy is indicated at least once in 49.1% (95% confidence interval 48.8-49.6%) of all new cancer patients in Australia. The optimal chemotherapy utilisation rates for individual tumour sites ranged from a low of 13% in thyroid cancers to a high of 94% in myeloma. The optimal chemotherapy utilisation rate can serve as a benchmark for planning chemotherapy services on a population basis. The model can be used to evaluate service delivery by comparing the benchmark rate with patterns of care data. The overall estimate for other countries can be obtained by substituting the relevant distribution of cancer types. It can also be used to predict future chemotherapy workload and can be easily modified to take into account future changes in cancer incidence, presentation stage or chemotherapy indications. Copyright © 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
Evaluation de l'intergiciel de communication DDS pour son utilisation dans le domaine avionique
NASA Astrophysics Data System (ADS)
Levesque-Landry, Kevin
Les aeronefs modernes doivent combler de plus en plus de fonctionnalites afin de satisfaire les besoins de la clientele. De ce fait, les besoins en communications des systemes avioniques sont grandissants. De plus, la portabilite et la reutilisabilite des applications sont des defis d'actualite dans le domaine avionique. De ce fait, ce projet de recherche vise a faire une evaluation de la technologie d'intergiciel de service de distribution de donnees (DDS) pour son utilisation dans le domaine avionique. Cette technologie permettrait de reduire la complexite des communications et faciliter la portabilite et reutilisabilite des applications grâce a son interface standardisee. Dans ce projet de recherche, la norme DDS est tout d'abord etudiee pour cibler les fonctionnalites qui sont utiles au domaine avionique. Les differentes polices de qualite de services sont ainsi etudiees et denotent la flexibilite de la technologie DDS. Un intergiciel DDS est egalement evalue dans un environnement de laboratoire afin de mesurer l'impact de l'utilisation de cette technologie sur les performances de latence ainsi que sur l'utilisation de la bande passante. Les resultats montrent une faible augmentation de la latence moyenne lorsque l'intergiciel DDS est utilise. L'intergiciel DDS est egalement utilise dans une etude de cas avec un AFCS (automatic flight control system) afin de quantifier les effets de son utilisation sur une application avionique. Les resultats montrent que l'utilisation de l'intergiciel DDS n'empeche pas l'AFCS d'atteindre la stabilite, mais qu'elle ralentit l'atteinte de cette derniere. Finalement, une etude de cas est effectuee afin de valider que la technologie DDS peut etre utilisee pour construire des systemes redondants. Les resultats montrent que l'intergiciel DDS permet de faire de la redondance de reserve sans avoir un impact visible sur les performances du systeme redondant.
Enhancing Solar Cell Efficiencies through 1-D Nanostructures
2009-01-01
The current global energy problem can be attributed to insufficient fossil fuel supplies and excessive greenhouse gas emissions resulting from increasing fossil fuel consumption. The huge demand for clean energy potentially can be met by solar-to-electricity conversions. The large-scale use of solar energy is not occurring due to the high cost and inadequate efficiencies of existing solar cells. Nanostructured materials have offered new opportunities to design more efficient solar cells, particularly one-dimensional (1-D) nanomaterials for enhancing solar cell efficiencies. These 1-D nanostructures, including nanotubes, nanowires, and nanorods, offer significant opportunities to improve efficiencies of solar cells by facilitating photon absorption, electron transport, and electron collection; however, tremendous challenges must be conquered before the large-scale commercialization of such cells. This review specifically focuses on the use of 1-D nanostructures for enhancing solar cell efficiencies. Other nanostructured solar cells or solar cells based on bulk materials are not covered in this review. Major topics addressed include dye-sensitized solar cells, quantum-dot-sensitized solar cells, and p-n junction solar cells.
NASA Technical Reports Server (NTRS)
Reames, D. V.; Richardson, I. G.; Barbier, L. M.
1991-01-01
The abundances of energetic ions accelerated from high-speed solar wind streams by shock waves formed at corotating interaction regions (CIRs) where high-speed streams overtake the lower-speed solar wind are examined. The observed element abundances appear to represent those of the high-speed solar wind, unmodified by the shock acceleration. These abundances, relative to those in the solar photosphere, are organized by the first ionization potential (FIP) of the ions in a way that is different from the FIP effect commonly used to describe differences between abundances in the solar photosphere and those in the solar corona, solar energetic particles (SEPs), and the low-speed solar wind. In contrast, the FIP effect of the ion abundances in the CIR events is characterized by a smaller amplitude of the differences between high-FIP and low-FIP ions and by elevated abundances of He, C, and S.
Solar Energy a Path to India's Prosperity
NASA Astrophysics Data System (ADS)
Chandra, Yogender Pal; Singh, Arashdeep; Kannojiya, Vikas; Kesari, J. P.
2018-05-01
Solar energy technology has grabbed a worldwide interest and attention these days. India also, having a huge solar influx and potential, is not falling back to feed its energy demand through non-conventional energy sources such as concentrating solar power (CSP) and photovoltaic (PV). This work will try to add some comprehensive insight on solar energy framework, policy, outlook and socio-economic challenges of India. This includes its prominent areas of working such as grid independent and `utility-scale' power production using CSP or PV power plants, rural as well as urban electrification using PV, solar powered public transportation systems, solar power in agrarian society—water pumping, irrigation, waste management and so on and so forth. Despite the fact that, a vast legion of furtherance and advancement has been done during the last decade of solar energy maturation and proliferation, improvements could be suggested so as to augment the solar energy usage in contrast to conventional energy sources in India.
Full-spectrum volumetric solar thermal conversion via photonic nanofluids.
Liu, Xianglei; Xuan, Yimin
2017-10-12
Volumetric solar thermal conversion is an emerging technique for a plethora of applications such as solar thermal power generation, desalination, and solar water splitting. However, achieving broadband solar thermal absorption via dilute nanofluids is still a daunting challenge. In this work, full-spectrum volumetric solar thermal conversion is demonstrated over a thin layer of the proposed 'photonic nanofluids'. The underlying mechanism is found to be the photonic superposition of core resonances, shell plasmons, and core-shell resonances at different wavelengths, whose coexistence is enabled by the broken symmetry of specially designed composite nanoparticles, i.e., Janus nanoparticles. The solar thermal conversion efficiency can be improved by 10.8% compared with core-shell nanofluids. The extinction coefficient of Janus dimers with various configurations is also investigated to unveil the effects of particle couplings. This work provides the possibility to achieve full-spectrum volumetric solar thermal conversion, and may have potential applications in efficient solar energy harvesting and utilization.
Spacecraft Charging Current Balance Model Applied to High Voltage Solar Array Operations
NASA Technical Reports Server (NTRS)
Willis, Emily M.; Pour, Maria Z. A.
2016-01-01
Spacecraft charging induced by high voltage solar arrays can result in power losses and degradation of spacecraft surfaces. In some cases, it can even present safety issues for astronauts performing extravehicular activities. An understanding of the dominant processes contributing to spacecraft charging induced by solar arrays is important to current space missions, such as the International Space Station, and to any future space missions that may employ high voltage solar arrays. A common method of analyzing the factors contributing to spacecraft charging is the current balance model. Current balance models are based on the simple idea that the spacecraft will float to a potential such that the current collecting to the surfaces equals the current lost from the surfaces. However, when solar arrays are involved, these currents are dependent on so many factors that the equation becomes quite complicated. In order for a current balance model to be applied to solar array operations, it must incorporate the time dependent nature of the charging of dielectric surfaces in the vicinity of conductors1-3. This poster will present the factors which must be considered when developing a current balance model for high voltage solar array operations and will compare results of a current balance model with data from the Floating Potential Measurement Unit4 on board the International Space Station.
New PCBM/carbon based electron transport layer for perovskite solar cells.
Mamun, Abdullah Al; Ava, Tanzila Tasnim; Zhang, Kai; Baumgart, Helmut; Namkoong, Gon
2017-07-21
Carbon is inherently abundant in nature and relatively inexpensive, which can potentially reduce the manufacturing cost of solar cells. In recent years, carbon has been used as a hole transport layer or counter electrode in perovskite solar cells. Herein, we demonstrate that carbon can also be used as a charge transport layer capable of enhancing the energy conversion efficiency of a CH 3 NH 3 PbI 3-x Cl x solar cell when carbon is combined with PCBM. Particularly, we have been able to deposit an ultra-flat carbon layer using an e-beam irradiation method, which exhibited much better conductivity than the competitive PCBM/C60 layer. In addition, quantitative analysis of interfacial charge dynamics shows that the quenching efficiency of PCBM/carbon is comparable to that of PCBM/C60 but better interface defect passivation and improved series and shunt resistances were observed when PCBM/carbon was employed. For the photovoltaic performance, the reference perovskite solar cell fabricated from the widely used PCBM/C60 has a power conversion efficiency (PCE) of 14% while the perovskite solar cell with PCBM/carbon has an increased PCE of 16%. Our results demonstrate the potential of the use of cost-effective carbon for perovskite solar cells, which could reduce production costs.
Impact of climate change on future concentrated solar power (CSP) production
NASA Astrophysics Data System (ADS)
Wild, Martin; Folini, Doris; Henschel, Florian
2017-02-01
Traditionally, for the planning and assessment of solar power plants, the amount of solar radiation incident on the Earth's surface is assumed to be invariable over the years. However, with changing climate and air pollution levels, solar resources may no longer be stable over time and undergo substantial decadal changes. Observational records covering several decades indeed confirm long-term changes in this quantity. In a previous study (Wild et al. 2015, Solar Energy)1 we examined how the latest generation of climate models (CMIP5) projects potential changes in surface solar radiation over the coming decades, and how this may affect, in combination with the expected greenhouse warming, future power output from photovoltaic (PV) systems. In the present complementary study, we use the CMIP5 model projections to estimate possible future changes in power output from Concentrated Solar Power (CSP) systems due to changing climate and air pollution levels up to the mid-21th century. The results indicate a potential for future increases in CSP production in many parts of the globe, with few exceptions such as the North of India and the irrelevant polar areas. Compared to the changes in PV production, the estimated future production changes by CSP are larger by a factor of 4.
Metamorphic III–V Solar Cells: Recent Progress and Potential
DOE Office of Scientific and Technical Information (OSTI.GOV)
Garcia, Ivan; France, Ryan M.; Geisz, John F.
Inverted metamorphic multijunction solar cells have been demonstrated to be a pathway to achieve the highest photovoltaic (PV) conversion efficiencies. Attaining high-quality lattice-mismatched (metamorphic) semiconductor devices is challenging. However, recent improvements to compositionally graded buffer epitaxy and junction structures have led to the achievement of high-quality metamorphic solar cells exhibiting internal luminescence efficiencies over 90%. For this high material quality, photon recycling is significant, and therefore, the optical environment of the solar cell becomes important. In this paper, we first present recent progress and performance results for 1- and 0.7-eV GaInAs solar cells grown on GaAs substrates. Then, an electroopticalmore » model is used to assess the potential performance improvements in current metamorphic solar cells under different realizable design scenarios. The results show that the quality of 1-eV subcells is such that further improving its electronic quality does not produce significant Voc increases in the four-junction inverted metamorphic subcells, unless a back reflector is used to enhance photon recycling, which would significantly complicate the structure. Conversely, improving the electronic quality of the 0.7-eV subcell would lead to significant Voc boosts, driving the progress of four-junction inverted metamorphic solar cells.« less
Cadby, Gemma; Melton, Phillip E; McCarthy, Nina S; Almeida, Marcio; Williams-Blangero, Sarah; Curran, Joanne E; VandeBerg, John L; Hui, Jennie; Beilby, John; Musk, A W; James, Alan L; Hung, Joseph; Blangero, John; Moses, Eric K
2018-01-01
Over two billion adults are overweight or obese and therefore at an increased risk of cardiometabolic syndrome (CMS). Obesity-related anthropometric traits genetically correlated with CMS may provide insight into CMS aetiology. The aim of this study was to utilise an empirically derived genetic relatedness matrix to calculate heritabilities and genetic correlations between CMS and anthropometric traits to determine whether they share genetic risk factors (pleiotropy). We used genome-wide single nucleotide polymorphism (SNP) data on 4671 Busselton Health Study participants. Exploiting both known and unknown relatedness, empirical kinship probabilities were estimated using these SNP data. General linear mixed models implemented in SOLAR were used to estimate narrow-sense heritabilities (h 2 ) and genetic correlations (r g ) between 15 anthropometric and 9 CMS traits. Anthropometric traits were adjusted by body mass index (BMI) to determine whether the observed genetic correlation was independent of obesity. After adjustment for multiple testing, all CMS and anthropometric traits were significantly heritable (h 2 range 0.18-0.57). We identified 50 significant genetic correlations (r g range: - 0.37 to 0.75) between CMS and anthropometric traits. Five genetic correlations remained significant after adjustment for BMI [high density lipoprotein cholesterol (HDL-C) and waist-hip ratio; triglycerides and waist-hip ratio; triglycerides and waist-height ratio; non-HDL-C and waist-height ratio; insulin and iliac skinfold thickness]. This study provides evidence for the presence of potentially pleiotropic genes that affect both anthropometric and CMS traits, independently of obesity.
NASA Technical Reports Server (NTRS)
Barghouty, A. F.; Adams, J. H., Jr.; Meyer, F.; Reinhold, c.
2010-01-01
Solar-wind induced sputtering of the lunar surface includes, in principle, both kinetic and potential sputtering. The role of the latter mechanism, however, in many focused studies has not been properly ascertained due partly to lack of data but can also be attributed to the assertion that the contribution of solar-wind heavy ions to the total sputtering is quite low due to their low number density compared to solar-wind protons. Limited laboratory measurements show marked enhancements in the sputter yields of slow-moving, highly-charged ions impacting oxides. Lunar surface sputtering yields are important as they affect, e.g., estimates of the compositional changes in the lunar surface, its erosion rate, as well as its contribution to the exosphere as well as estimates of hydrogen and water contents. Since the typical range of solar-wind ions at 1 keV/amu is comparable to the thickness of the amorphous rim found on lunar soil grains, i.e. few 10s nm, lunar simulant samples JSC-1A AGGL are specifically enhanced to have such rims in addition to the other known characteristics of the actual lunar soil particles. However, most, if not all laboratory studies of potential sputtering were carried out in single crystal targets, quite different from the rim s amorphous structure. The effect of this structural difference on the extent of potential sputtering has not, to our knowledge, been investigated to date.
Supercharging of the Lunar Surface by Solar Wind Halo Electrons
NASA Astrophysics Data System (ADS)
Stubbs, T. J.; Farrell, W. M.; Collier, M. R.; Halekas, J. S.; Delory, G. T.; Holland, M. P.; Vondrak, R. R.
2007-12-01
Lunar surface potentials can reach several kilovolts negative during Solar Energetic Particle (SEPs) events, as indicated by recent analysis of data from the Lunar Prospector Electron Reflectometer (LP/ER). The lunar surface- plasma interactions that result in such extreme surface potentials are poorly characterized and understood. Extreme lunar surface charging, and the associated electrostatic discharges and transport of charged dust, will likely present significant hazards to future human explorers. This is of particular concern near the terminator and polar regions, such as the South Pole/Aiken Basin site planned for NASA's manned outpost. It is the flux of electrons from the ambient plasma that charges the surface of the Moon to negative potentials. In the solar wind, the electron temperature is typically ~10 eV which tends to charge the lunar surface to ~100 V negative in shadow. However, during space weather events the solar wind electrons are often better described by the sum of two Maxwellian distributions, referred to as the "core" and "halo" components. The core electrons are relatively cool and dense (e.g., ~10 eV and ~10/cc), whereas the halo electrons are hot and tenuous (e.g., ~100 eV and ~0.1/cc). Despite, the tenuous nature of the halo electrons, our surface charging model - using core and halo electron data derived from the Solar Wind Experiment (SWE) aboard the Wind spacrcraft - predicts that they are capable of "supercharging" the lunar surface to kilovolt potentials during space weather events, which could explain the LP/ER observations.
Stem Inc. SunShot Incubator Program Final Technical Report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Butterfield, Karen
In this Energy Storage Control Algorithms project, Stem sought to develop tools and control algorithms to increase the value and reduce balance-of-system and grid integration costs associated with adding distributed solar generation to the grid. These advances fell under the headings SolarScope and SolarController. Stem sought to create initial market traction with a fully commercialized product for the solar industry to size storage systems (SolarScope) as well as a solar intermittency-mitigation framework for utilities (SolarController) in the course of the project. The company sought to align strategic growth plans and enable the rollout of the products to broader audiences inmore » multiple geographic regions by leveraging the major solar companies in the national market as partners. Both final products were both intended to be commercialized. They are: SolarScope: Analysis tool to identify viable PV + storage projects and thereby expedite the sales and interconnection processes. SolarScope combines customer load data, PV production estimates, utility rate tariff, and simulated storage into a simple user interface for PV developers. Developers can easily identify viable solar + storage sites without the need for complex and time consuming, site-by-site spreadsheet modeling. SolarContoller: Tool to autonomously dispatch distributed storage in order to mitigate voltage fluctuation and reduce curtailment. SolarController co-optimizes, in real time, storage dispatch for circuit stability and curtailment reduction, enabling higher penetrations of PV. SolarController is automated, not requiring utility dispatch or management, as Stem hardware senses grid voltage, frequency, customer load, PV production, and power factor. In the end the two products met with different outcomes. SolarScope was tested by potential users, and continues to be used as a foundational platform for partnership with key solar industry partners. SolarController, on the other hand, was successful in lab testing but was not commercialized due to a lack of marketability and lack of interested customer base. Together the development of these two products marked a material step forward for Stem; and a new milestone along the pathway of integration for the solar and storage industries. SolarScope is leading to real, out-of-the-lab project development in storage + solar for the commercial customer sector. Meanwhile SolarController has opened the eyes of regulators and utility executives alike to the potential of distributed solar and by doing so, has moved the conversation forward for the integration of distributed energy resources more broadly on the grid.« less
Recent Advances in Solar Cell Technology
NASA Technical Reports Server (NTRS)
Landis, Geoffrey A.; Bailey, Sheila G.; Piszczor, Michael F., Jr.
1996-01-01
The advances in solar cell efficiency, radiation tolerance, and cost over the last decade are reviewed. Potential performance of thin-film solar cells in space are discussed, and the cost and the historical trends in production capability of the photovoltaics industry are considered with respect to the requirements of space power systems. Concentrator cells with conversion efficiency over 30%, and nonconcentrating solar cells with efficiency over 25% are now available, and advanced radiation-tolerant cells and lightweight, thin-film arrays are both being developed. Nonsolar applications of solar cells, including thermophotovoltaics, alpha- and betavoltaics, and laser power receivers, are also discussed.
NASA Astrophysics Data System (ADS)
Murphy, L. M.; Hauser, S. G.; Clyne, R. J.
1992-05-01
Concentrated solar radiation is now a viable alternative energy source for many advanced manufacturing processes. Researchers at the National Renewable Energy Laboratory (NREL) have demonstrated the feasibility of processes such as solar-induced surface transformation of materials (SISTM), solar-based manufacturing, and solar-pumped lasers. Researchers are also using sunlight to decontaminate water and soils polluted with organic compounds; these techniques could provide manufacturers with innovative alternatives to traditional methods of waste management. The solar technology that is now being integrated into today's manufacturing processes offers even greater potential for tomorrow, especially as applied to the radiation-abundant environment available in space and on the lunar surface.
NASA Astrophysics Data System (ADS)
Murphy, Lawrence M.; Hauser, Steven G.; Clyne, Richard J.
1991-12-01
Concentrated solar radiation is now a viable alternative source for many advanced manufacturing processes. Researchers at the National Renewable Energy Laboratory (NREL) have demonstrated the feasibility of processes such as solar induced surface transformation of materials (SISTM), solar based manufacturing, and solar pumped lasers. Researchers are also using sunlight to decontaminate water and soils polluted with organic compounds; these techniques could provide manufacturers with innovative alternatives to traditional methods of waste management. The solar technology that is now being integrated into today's manufacturing processes offer greater potential for tomorrow, especially as applied to the radiation abundant environment available in space and on the lunar surface.
Evaluation of AlsubxGasub1-xsubAs solar cells
NASA Technical Reports Server (NTRS)
Loo, R. Y.; Kamath, G. S.; Knechtli, R. C.; Narayanan, A.; Li, S. S.
1985-01-01
Single junction GaAs solar cells have already attained an efficiency of 19% AMO which could potentially be increased to approx 20%, with some optimization. To achieve the higher efficiency the concept of multibandgap solar cells which utilizes a wider region of the solar spectrum should be sed. One of the materials for fabricating the top cell in a multibandgap solar cell is AlGaAs because it is compatible with GaAs in bandgap and lattice match. This is a very important consideration from the materials technology point of view, and the viability of this approach is evaluated.
NASA Technical Reports Server (NTRS)
Murphy, Lawrence M.; Hauser, Steven G.; Clyne, Richard J.
1991-01-01
Concentrated solar radiation is now a viable alternative source for many advanced manufacturing processes. Researchers at the National Renewable Energy Laboratory (NREL) have demonstrated the feasibility of processes such as solar induced surface transformation of materials (SISTM), solar based manufacturing, and solar pumped lasers. Researchers are also using sunlight to decontaminate water and soils polluted with organic compounds; these techniques could provide manufacturers with innovative alternatives to traditional methods of waste management. The solar technology that is now being integrated into today's manufacturing processes offer greater potential for tomorrow, especially as applied to the radiation abundant environment available in space and on the lunar surface.
NASA Technical Reports Server (NTRS)
Kudirka, A. A.
1984-01-01
Materials for high-temperature use reviewed. Report discusses characteristics of ceramics and assesses potential of candidate materials in solar receivers. Design requirements presented, including those for receiver with fluid exit temperatures up to 1,425 degrees C.
Advances in Perovskite Solar Cells
Zuo, Chuantian; Bolink, Henk J.; Han, Hongwei; Huang, Jinsong
2016-01-01
Organolead halide perovskite materials possess a combination of remarkable optoelectronic properties, such as steep optical absorption edge and high absorption coefficients, long charge carrier diffusion lengths and lifetimes. Taken together with the ability for low temperature preparation, also from solution, perovskite‐based devices, especially photovoltaic (PV) cells have been studied intensively, with remarkable progress in performance, over the past few years. The combination of high efficiency, low cost and additional (non‐PV) applications provides great potential for commercialization. Performance and applications of perovskite solar cells often correlate with their device structures. Many innovative device structures were developed, aiming at large‐scale fabrication, reducing fabrication cost, enhancing the power conversion efficiency and thus broadening potential future applications. This review summarizes typical structures of perovskite solar cells and comments on novel device structures. The applications of perovskite solar cells are discussed. PMID:27812475
NASA Technical Reports Server (NTRS)
Markson, R.
1980-01-01
The ionospheric potential and galactic cosmic radiation, found to be inversely correlated with the solar wind velocity are examined as being germane to weather modification. Since the ionospheric potential is proportional to the fair weather electric field intensity and cosmic radiation is the dominant source of atmospheric ionization, it is concluded that the Earth's overall electric field varies in phase with atmospheric ionization and that the latter is modulated by the solar wind. A proposed mechanism, in which solar control of ionizing radiation influences atmospheric electrification and thus possibly cloud physical processes is discussed. An experimental approach to critically test the proposed mechanism through comparison of the temporal variation of the Earth's electric field with conditions in the interplanetary medium is outlined.
NASA Technical Reports Server (NTRS)
Billman, Kenneth W.; Gilbreath, William P.; Bowen, Stuart W.
1978-01-01
A system of orbiting, large-area, low mass density reflector satellites which provide nearly continuous solar energy to a world-distributed set of conversion sites is examined under the criteria for any potential new energy system: technical feasibility, significant and renewable energy impact, economic feasibility and social/political acceptability. Although many technical issues need further study, reasonable advances in space technology appear sufficient to implement the system. The enhanced insolation is shown to greatly improve the economic competitiveness of solar-electric generation to circa 1995 fossil/nuclear alternatives. The system is shown to have the potential for supplying a significant fraction of future domestic and world energy needs. Finally, the environmental and social issues, including a means for financing such a large shift to a world solar energy dependence, is addressed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Grippo, Mark; Hayse, John W.; O’Connor, Ben L.
The cumulative impacts of utility-scale solar energy facilities on aquatic ecosystems in the Southwestern United States are of concern, considering the many existing regional anthropogenic stressors. We review the potential impacts of solar energy development on aquatic habitat and biota. The greatest potential for impacts is related to the loss, fragmentation, or prolonged drying of ephemeral water bodies and drainage networks resulting from the loss of desert washes within the construction footprint of the facility. Groundwater-dependent aquatic habitat may also be affected by operational groundwater withdrawal in the case of water-intensive solar technologies. Solar panels have also been found tomore » attract aquatic insects and waterbirds, potentially resulting in mortality. Avoiding construction activity near perennial and intermittent surface waters is the primary means of reducing impacts on aquatic habitats, followed by measures to minimize erosion, sedimentation, and contaminant inputs into waterways. Currently, significant data gaps make solar facility impact assessment and mitigation more difficult. Examples include the need for more regional and site-specific studies of surface–groundwater connectivity, more detailed maps of regional stream networks and riparian vegetation corridors, as well as surveys of the aquatic communities inhabiting ephemeral streams. In addition, because they often lack regulatory protection, there is also a need to develop valuation criteria for ephemeral waters based on their ecological and hydrologic function within the landscape. By addressing these research needs, we can achieve the goal of greater reliance on solar energy, while at the same time minimizing impacts on desert ecosystems.« less
Jylhä, Kirsti; Ruosteenoja, Kimmo; Jokisalo, Juha; Pilli-Sihvola, Karoliina; Kalamees, Targo; Mäkelä, Hanna; Hyvönen, Reijo; Drebs, Achim
2015-09-01
Dynamic building energy simulations need hourly weather data as input. The same high temporal resolution is required for assessments of future heating and cooling energy demand. The data presented in this article concern current typical values and estimated future changes in outdoor air temperature, wind speed, relative humidity and global, diffuse and normal solar radiation components. Simulated annual and seasonal delivered energy consumptions for heating of spaces, heating of ventilation supply air and cooling of spaces in the current and future climatic conditions are also presented for an example house, with district heating and a mechanical space cooling system. We provide details on how the synthetic future weather files were created and utilised as input data for dynamic building energy simulations by the IDA Indoor Climate and Energy program and also for calculations of heating and cooling degree-day sums. The information supplied here is related to the research article titled "Energy demand for the heating and cooling of residential houses in Finland in a changing climate" [1].
Silicon solar cells made by a self-aligned, selective-emitter, plasma-etchback process
Ruby, Douglas S.; Schubert, William K.; Gee, James M.
1999-01-01
A potentially low-cost process for forming and passivating a selective emitter. The process uses a plasma etch of the heavily doped emitter to improve its performance. The grids of the solar cell are used to mask the plasma etch so that only the emitter in the region between the grids is etched, while the region beneath the grids remains heavily doped for low contact resistance. This process is potentially low-cost because it requires no alignment. After the emitter etch, a silicon nitride layer is deposited by plasma-enhanced, chemical vapor deposition, and the solar cell is annealed in a forming gas.
Silicon solar cells made by a self-aligned, selective-emitter, plasma-etchback process
Ruby, D.S.; Schubert, W.K.; Gee, J.M.
1999-02-16
A potentially low-cost process for forming and passivating a selective emitter. The process uses a plasma etch of the heavily doped emitter to improve its performance. The grids of the solar cell are used to mask the plasma etch so that only the emitter in the region between the grids is etched, while the region beneath the grids remains heavily doped for low contact resistance. This process is potentially low-cost because it requires no alignment. After the emitter etch, a silicon nitride layer is deposited by plasma-enhanced, chemical vapor deposition, and the solar cell is annealed in a forming gas. 5 figs.
Site selection feasibility for a solar energy system on the Fairbanks Federal Building
NASA Technical Reports Server (NTRS)
1978-01-01
A feasibility study was performed for the installation of a solar energy system on the Federal Building in Fairbanks, Alaska, a multifloor office building with an enclosed parking garge. The study consisted of determining the collectable solar energy at the Fairbanks site on a monthly basis and comparing this to the monthly building heating load. Potential conventional fuel savings were calculated on a monthly basis and the overall economics of the solar system applications were considered. Possible solar system design considerations, collector and other system installation details, interface of the solar system with the conventional HVAC systems, and possible control modes were all addressed. Conclusions, recommendations and study details are presented.
Research opportunities to advance solar energy utilization.
Lewis, Nathan S
2016-01-22
Major developments, as well as remaining challenges and the associated research opportunities, are evaluated for three technologically distinct approaches to solar energy utilization: solar electricity, solar thermal, and solar fuels technologies. Much progress has been made, but research opportunities are still present for all approaches. Both evolutionary and revolutionary technology development, involving foundational research, applied research, learning by doing, demonstration projects, and deployment at scale will be needed to continue this technology-innovation ecosystem. Most of the approaches still offer the potential to provide much higher efficiencies, much lower costs, improved scalability, and new functionality, relative to the embodiments of solar energy-conversion systems that have been developed to date. Copyright © 2016, American Association for the Advancement of Science.
Midmarket Solar Policies in the United States: A Guide for Midsized Solar Customers
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tian, Tian; Liu, Chang; O'Shaughnessy, Eric
The midscale market for solar photovoltaics (PV) has not experienced the same high growth rate as residential- or utility-scale market segments in the past five years when solar PV deployment increased rapidly. Midscale solar can be defined as behind-the-meter solar PV between 50 kilowatts and 2 megawatts adopted by multi-housing residential, commercial, industrial, non-profit, and other entities. A number of challenges face the midscale segment, including difficulties in contracting, mismatch between tenant lease and PV financing terms, high transaction costs relative to project sizes, and inefficiencies in matching prospective projects with capital. The changing policy landscape across U.S. states providesmore » both opportunities and challenges to midmarket solar. Some states, such as California, are expanding system capacity limits for policies such as net metering, thus enabling a wider range of customers to benefit from excess generation. A number of states and utilities are making changes to rate design to introduce new or higher user fees for solar customers or reduced tariffs for net metering, which decrease the value of solar generation. An understanding of these policies relative to project feasibility and economics is important for prospective customers to make informed decisions to adopt solar PV. This guide complements existing solar policy resources to help potential customers navigate through the policy landscape in order to make informed decisions for their solar investment. The first part of this guide introduces the key solar policies necessary for policy-based decision-making, which involves using knowledge of a solar policy to improve project economics and efficiency. Policies that could result in policy-based decisions include interconnection standards, net metering, user fees, incentives, and third-party ownership policies. The goal of this section is to equip prospective customers and project developers with the tools necessary to understand and use solar policies in a dynamic policy environment. The second part of this guide provides a complete, state-by-state inventory of midmarket solar policies for potential customers and developers to use as reference when making policy-based decisions. Although solar policies are dynamic, the profiles provide a framework for assessing policies to build the parameters that could be used to determine feasibility and structure of a solar PV system for midmarket customers and developers.« less
2011-12-28
shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number...by CMEs; (2) the angular orientation of newly emerged magnetic flux on the solar surface relative to stable filaments plays a role in how rapidly the...potential of exploiting ISOON observations to increase our understanding of solar eruptions, a requirement for improved prediction and mitigation of space
The distribution of solar global radiation over Romania
DOE Office of Scientific and Technical Information (OSTI.GOV)
Badescu, V.
1990-01-01
This article shows the monthly distributions of solar global radiation over Romania. The results have been tested by the author under the climatic features of Romania. Meteorological data from 29 localities have been used in computations. The results show Romania has a solar potential higher than that of the world maps of solar radiation. It was pointed out that local radiation peculiarities, expressed as strong deviations from the law of latitudinal variation, are mainly determined by the atmospheric circulation features.
Solar applications analysis for energy storage
NASA Technical Reports Server (NTRS)
Blanchard, T.
1980-01-01
The role of energy storage as it relates to solar energy systems is considered. Storage technologies to support solar energy applications, the status of storage technologies, requirements and specifications for storage technologies, and the adequacy of the current storage research and development program to meet these requirements are among the factors discussed. Emphasis is placed on identification of where the greatest potential exists for energy storage in support of those solar energy systems which could have a significant impact on the U.S. energy mix.
Unique properties of halide perovskites as possible origins of the superior solar cell performance.
Yin, Wan-Jian; Shi, Tingting; Yan, Yanfa
2014-07-16
Halide perovskites solar cells have the potential to exhibit higher energy conversion efficiencies with ultrathin films than conventional thin-film solar cells based on CdTe, CuInSe2 , and Cu2 ZnSnSe4 . The superior solar-cell performance of halide perovskites may originate from its high optical absorption, comparable electron and hole effective mass, and electrically clean defect properties, including point defects and grain boundaries. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
The Optical Flow Technique on the Research of Solar Non-potentiality
NASA Astrophysics Data System (ADS)
Liu, Ji-hong; Zhang, Hong-qi
2010-06-01
Several optical flow techniques, which have being applied to the researches of solar magnetic non-potentiality recently, have been summarized here. And a few new non-potential parameters which can be derived from them have been discussed, too. The main components of the work are presented as follows: (1) The optical flow techniques refers to a series of new image analyzing techniques arisen recently on the researches of solar magnetic non-potentiality. They mainly include LCT (local correlation tracking), ILCT (inductive equation combining with LCT), MEF (minimum energy effect), DAVE (differential affine velocity estimator) and NAVE (nonlinear affine velocity estimator). Their calculating and applying conditions, merits and deficiencies, all have been discussed detailedly in this work. (2) Benefit from the optical flow techniques, the transverse velocity fields of the magnetic features on the solar surface may be determined by a time sequence of high-quality images currently produced by high-resolution observations either from the ground or in space. Consequently, several new non-potential parameters may be acquired, such as the magnetic helicity flux, the induced electric field in the photosphere, the non-potential magnetic stress (whose area integration is the Lorentz force), etc. Then we can determine the energy flux across the photosphere, and subsequently evaluate the energy budget. Former works on them by small or special samples have shown that they are probably related closely to the erupting events, such as flare, filament eruptions and coronal mass ejections.
NASA Astrophysics Data System (ADS)
Prinsloo, Gerro; Dobson, Robert; Brent, Alan; Mammoli, Andrea
2016-05-01
Concentrating solar power co-generation systems have been identified as potential stand-alone solar energy supply solutions in remote rural energy applications. This study describes the modelling and synthesis of a combined heat and power Stirling CSP system in order to evaluate its potential performance in small off-grid rural village applications in Africa. This Stirling micro-Combined Heat and Power (micro-CHP) system has a 1 kW electric capacity, with 3 kW of thermal generation capacity which is produced as waste heat recovered from the solar power generation process. As part of the development of an intelligent microgrid control and distribution solution, the Trinum micro-CHP system and other co-generation systems are systematically being modelled on the TRNSYS simulation platform. This paper describes the modelling and simulation of the Trinum micro-CHP configuration on TRNSYS as part of the process to develop the control automation solution for the smart rural microgrid in which the Trinum will serve as a solar powerpack. The results present simulated performance outputs for the Trinum micro-CHP system for a number of remote rural locations in Africa computed from real-time TRNSYS solar irradiation and weather data (yearly, monthly, daily) for the relevant locations. The focus of this paper is on the parametric modelling of the Trinum Stirling micro-CHP system, with specific reference to this system as a TRNSYS functional block in the microgrid simulation. The model is used to forecast the solar energy harvesting potential of the Trinum micro-CHP unit at a number of remote rural sites in Africa.
Organic and Hybrid Organic Solid-State Photovoltaic Materials and Devices
2014-03-06
Microscopy Research, 2012, 7, 158-169. Organic photovoltaic materials, hybrid organic devices, solar cells 6 1 FINAL TECHNICAL REPORT 1... hybrids have potential applications in solar cells and may thus provide mobile energy sources for aircraft and soldier technologies. Modeling and...modeling and simulation developed in this project are encouraging further development. 2. Technical Activities Hybrid organic solar cells are an
A users evaluation of SAMIS. [Solar Array Manufacturing Industry Simulation
NASA Technical Reports Server (NTRS)
Grenon, L. A.; Coleman, M. G.
1981-01-01
SAMIS, the Solar Array Manufacturing Industry Simulation computer program was developed by Jet Propulsion Laboratories (JPL) to provide a method whereby manufacturers or potential manufacturers of photovoltaics could simulate a solar industry using their own particular approach. This paper analyzes the usefulness of SAMIS to a growing photovoltaic industry and clearly illustrates its limitations as viewed by an industrial user.
CdS/TiO2 photoanodes via solution ion transfer method for highly efficient solar hydrogen generation
NASA Astrophysics Data System (ADS)
Krishna Karuturi, Siva; Yew, Rowena; Reddy Narangari, Parvathala; Wong-Leung, Jennifer; Li, Li; Vora, Kaushal; Tan, Hark Hoe; Jagadish, Chennupati
2018-03-01
Cadmium sulfide (CdS) is a unique semiconducting material for solar hydrogen generation applications with a tunable, narrow bandgap that straddles water redox potentials. However, its potential towards efficient solar hydrogen generation has not yet been realized due to low photon-to-current conversions, high charge carrier recombination and the lack of controlled preparation methods. In this work, we demonstrate a highly efficient CdS/TiO2 heterostructured photoelectrode using atomic layer deposition and solution ion transfer reactions. Enabled by the well-controlled deposition of CdS nanocrystals on TiO2 inverse opal (TiIO) nanostructures using the proposed method, a saturation photocurrent density of 9.1 mA cm-2 is realized which is the highest ever reported for CdS-based photoelectrodes. We further demonstrate that the passivation of a CdS surface with an ultrathin amorphous layer (˜1.5 nm) of TiO2 improves the charge collection efficiency at low applied potentials paving the way for unassisted solar hydrogen generation.
NASA Astrophysics Data System (ADS)
O'Brien, Leela; Juhász, Antal; Sternovsky, Zoltan; Horányi, Mihály
2018-07-01
This article reports on an investigation of the effect of interplanetary coronal mass ejections (ICMEs) on the transport and delivery of nano-dust to 1 AU. Charged nanometer-sized dust particles are expected to be generated close to the Sun and interact strongly with the solar wind as well as solar transient events. Nano-dust generated outside of ∼0.2 AU are picked up and transported away from the Sun due to the electromagnetic forces exerted by the solar wind. A numerical model has been developed to calculate the trajectories of nano-dust through their interaction with the solar wind and explore the potential for their detection near Earth's orbit (Juhasz and Horanyi, 2013). Here, we extend the model to include the interaction with interplanetary coronal mass ejections. We report that ICMEs can greatly alter nano-dust trajectories, their transport to 1 AU, and their distribution near Earth's orbit. The smallest nano-dust (<10 nm) can be delivered to 1 AU in high concentration. Thus, the nature of the interaction between nano-dust and ICMEs could potentially be revealed by simultaneous measurements of nano-dust fluxes and solar wind particles/magnetic fields.
Simulated Space Environment Effects on a Candidate Solar Sail Material
NASA Technical Reports Server (NTRS)
Kang, Jin Ho; Bryant, Robert G.; Wilkie, W. Keats; Wadsworth, Heather M.; Craven, Paul D.; Nehls, Mary K.; Vaughn, Jason A.
2017-01-01
For long duration missions of solar sails, the sail material needs to survive harsh space environments and the degradation of the sail material controls operational lifetime. Therefore, understanding the effects of the space environment on the sail membrane is essential for mission success. In this study, we investigated the effect of simulated space environment effects of ionizing radiation, thermal aging and simulated potential damage on mechanical, thermal and optical properties of a commercial off the shelf (COTS) polyester solar sail membrane to assess the degradation mechanisms on a feasible solar sail. The solar sail membrane was exposed to high energy electrons (about 70 keV and 10 nA/cm2), and the physical properties were characterized. After about 8.3 Grad dose, the tensile modulus, tensile strength and failure strain of the sail membrane decreased by about 20 95%. The aluminum reflective layer was damaged and partially delaminated but it did not show any significant change in solar absorbance or thermal emittance. The effect on mechanical properties of a pre-cracked sample, simulating potential impact damage of the sail membrane, as well as thermal aging effects on metallized PEN (polyethylene naphthalate) film will be discussed.
NASA Technical Reports Server (NTRS)
Gopalswamy, N.; Davila, J. M.; St Cyr, O. C.; Sittler, E. C.; Auchere, F.; Duvall, Jr. T. L.; Hoeksema, J. T.; Maksimovic, M.; MacDowall, R. J.; Szabo, A.;
2011-01-01
This paper describes the scientific rationale for an L5 mission and a partial list of key scientific instruments the mission should carry. The L5 vantage point provides an unprecedented view of the solar disturbances and their solar sources that can greatly advance the science behind space weather. A coronagraph and a heliospheric imager at L5 will be able to view CMEs broadsided, so space speed of the Earth-directed CMEs can be measured accurately and their radial structure discerned. In addition, an inner coronal imager and a magnetograph from L5 can give advance information on active regions and coronal holes that will soon rotate on to the solar disk. Radio remote sensing at low frequencies can provide information on shock-driving CMEs, the most dangerous of all CMEs. Coordinated helioseismic measurements from the Sun Earth line and L5 provide information on the physical conditions at the base of the convection zone, where solar magnetism originates. Finally, in situ measurements at L5 can provide information on the large-scale solar wind structures (corotating interaction regions (CIRs)) heading towards Earth that potentially result in adverse space weather.
Assessment of the potential of solar thermal small power systems in small utilities
NASA Technical Reports Server (NTRS)
Steitz, P.; Mayo, L. G.; Perkins, S. P., Jr.
1978-01-01
The potential economic benefit of small solar thermal electric power systems to small municipal and rural electric utilities is assessed. Five different solar thermal small power system configurations were considered in three different solar thermal technologies. The configurations included: (1) 1 MW, 2 MW, and 10 MW parabolic dish concentrators with a 15 kW heat engine mounted at the focal point of each dish, these systems utilized advanced battery energy storage; (2) a 10 MW system with variable slat concentrators and central steam Rankine energy conversion, this system utilized sensible thermal energy storage; and (3) a 50 MW central receiver system consisting of a field of heliostats concentrating energy on a tower-mounted receiver and a central steam Rankine conversion system, this system also utilized sensible thermal storage. The results are summarized in terms of break-even capital costs. The break-even capital cost was defined as the solar thermal plant capital cost which would have to be achieved in order for the solar thermal plants to penetrate 10 percent of the reference small utility generation mix by the year 2000. The calculated break-even capital costs are presented.