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Sample records for dust collectors

  1. Dust collector

    Energy Technology Data Exchange (ETDEWEB)

    Sahourin, H.

    1988-03-22

    This invention relates to a dust collector or filter which may be used for large volume cleaning air for gases or for separating out industrial byproducts such as wood chips, sawdust, and shavings. It relies on filtration or separation using only a uniquely configured medium. A primary, but not exclusive, purpose of the invention is to enable very large throughput, capable of separating or filtering of gases containing up to three or more tons of byproduct with a minimum pressure-drop across the device. No preliminary cycloning, to remove major particulates is necessary. The collector generally comprises a continuous and integral filter medium which is suspended from a plurality of downwardly extending frames forming a series of separate elements having a triangular cross-section, each element being relatively wide at the top and narrow at the bottom to define, between adjacent elements, a divergent collecting space which is wide at the bottom. 11 figs.

  2. Four Interstellar Dust Candidates from the Stardust Interstellar Dust Collector

    Science.gov (United States)

    Westphal, A. J.; Allen, C.; Bajt, S.; Bechtel, H. A.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Burchell, M.; Burghammer, M.; hide

    2011-01-01

    In January 2006, the Stardust sample return capsule returned to Earth bearing the first solid samples from a primitive solar system body, Comet 81P/Wild2, and a collector dedicated to the capture and return of contemporary interstellar dust. Both collectors were approx. 0.1 sq m in area and were composed of aerogel tiles (85% of the collecting area) and aluminum foils. The Stardust Interstellar Dust Collector (SIDC) was exposed to the interstellar dust stream for a total exposure factor of 20 sq m/day. The Stardust Interstellar Preliminary Examination (ISPE) is a consortium-based project to characterize the collection using nondestructive techniques. The goals and restrictions of the ISPE are described . A summary of analytical techniques is described.

  3. The Stardust Interstellar Dust Collector and Stardust@home

    Science.gov (United States)

    Westphal, A. J.; Anderson, D.; Bastien, R.; Butterworth, A.; Frank, D.; Gainsforth, Z.; Kelley, N.; Lettieri, R.; Mendez, B.; Prasad, R.; Tsitrin, S.; von Korff, J.; Warren, J.; Wertheimer, D.; Zhang, A.; Zolensky, M.

    2006-12-01

    The Stardust sample return mission is effectively two missions in one. Stardust brought back to earth for analytical study the first solid samples from a known solar system body beyond the moon, comet Wild2. The first results of the analyses of these samples are reported elsewhere in this session. In a separate aerogel collector, Stardust also captured and has returned the first samples of contemporary interstellar dust. Landgraf et al. [1] has estimated that ~ 50 interstellar dust particles in the micron size range have been captured in the Stardust Interstellar Dust Collector. Their state after capture is unknown. Before analysis of these particles can begin, they must be located in the collector. Here we describe the current status of Stardust@home, the massively distributed public search for these tiny interstellar dust particles. So far more than 13,000 volunteers have collectively performed more than 10,000,000 searches in stacks of digital images of ~10% of the collector. We report new estimates of the flux of interplanetary dust at ~2 AU based on the results of this search, and will compare with extant models[2]. References: [1] Landgraf et al., (1999) Planet. Spac. Sci. 47, 1029. [2] Staubach et al. (2001) in Interplanetary Dust, E. Grün, ed., Astron. &Astro. Library, Springer, 2001.

  4. Change in dust collection efficiency of liquid collectors in conditions of dedusting liquid recirculation

    Directory of Open Access Journals (Sweden)

    Krawczyk Janusz

    2017-12-01

    Full Text Available The high efficiency of industrial wet scrubbers is the result of a simultaneous formation of dust particle collectors. Collectors can be understood as droplets of atomised liquid, bubbles formed in the conditions of intensive barbotage, liquid surface and wet surfaces. All collectors are formed during the operation of a circulating unit. The efficiency of dust collection process also depends on the ability of dust particles to be absorbed by collectors. The study provides an experimental analysis of the effect of the increasing concentration of a dust collection liquid in the conditions of full liquid recirculation on the efficiency of dust collection process in the examined types of collectors.

  5. 30 CFR 18.21 - Machines equipped with powered dust collectors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Machines equipped with powered dust collectors... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.21 Machines equipped with powered dust collectors. Powered dust...

  6. Analysis of "Midnight" Tracks in the Stardust Interstellar Dust Collector: Possible Discovery of a Contemporary Interstellar Dust Grain

    Science.gov (United States)

    Westphal, A. J.; Allen, C.; Bajit, S.; Bastien, R.; Bechtel, H.; Bleuet, P.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; hide

    2010-01-01

    In January 2006, the Stardust sample return capsule returned to Earth bearing the first solid samples from a primitive solar system body, Comet 81P/Wild2, and a collector dedicated to the capture and return of contemporary interstellar dust. Both collectors were approximately 0.1m(exp 2) in area and were composed of aerogel tiles (85% of the collecting area) and aluminum foils. The Stardust Interstellar Dust Collector (SIDC) was exposed to the interstellar dust stream for a total exposure factor of 20 m(exp 2) day. The Stardust Interstellar Preliminary Examination (ISPE) is a three-year effort to characterize the collection using nondestructive techniques.

  7. Effect of the Dust on the Performance of Solar Water Collectors in Iraq

    Directory of Open Access Journals (Sweden)

    Omer Khalil Ahmed

    2016-02-01

    Full Text Available There is little research about it in present literatures in Iraq. So the effect of dust accumulation on the performance of conventional of solar collectors is analyzed. The experimental study was carried out mainly on a flat solar collector, which comprised the major part of this work. According to the experimental results obtained, there is a limited decrease in the instantaneous efficiency which was 1.6 % for the dirty collector. At load condition, the outlet temperature reaches a maximum value of 43.85oC at 12 noon without dust on the front glass and 33.7 oC in the presence of the dust. The instantaneous efficiency reaches its maximum value of 49.74 % at 12 noon without dust and 48.94% with dust after that the efficiency was decreased. The variation of useful transferred energy closely follows the variation of solar intensity and reaches its maximum value of 690 W/m2 at 12 noon in the presence of the dust for this particular day. It is also observed that, at the second half of the day, there is a large decrease in the instantaneous efficiency resulting from a large reduction in the useful energy transferred. Therefore, for Iraqi places, daily cleaning of the glass covers is strictly recommended as part of the maintenance works but the equipment should be cleaned immediately after a dust storm to keep the collector efficient. Article History: Received August 16, 2015; Received in revised form Nov 17, 2015; Accepted Dec 19, 2015; Available onlineHow to Cite This Article: Ahmed, O.K (2016. Effect of the Dust on the Performance of Solar Water Collectors in Iraq. Int. Journal of Renewable Energy Development, 5(1, 65-72.http://dx.doi.org/10.14710/ijred.5.1.65-72 

  8. Design, Implementation & Assessment of Local Exhaust Ventilation System and dust collectors for crushing unit

    Directory of Open Access Journals (Sweden)

    Farshid Ghorbani shahna

    2015-09-01

    Full Text Available Background & objective: Industrial ventilation systems and dust collectors are effective solutions to reduce particulate emissions in the workplace and environmental in mineral processes. In this study, Local Exhaust Ventilation System and dust collectors for control of emitted silica, coke, silicon carbide dusts from crushing unit was designed and evaluated. Methods: : Local Exhaust ventilation system based on standards and guides was designed and implemented after field study of the processes and sources of air pollutants. A set comprised of the four parallel cyclones (Stairmand model and a new design of the scrubber had been used for dust control. After set-up of systems, its effectiveness in reducing the exposure of workers in the workshops and dust collecting were assessed. Results: Test results were significant differences between the concentration of particles in both on and off the ventilation system revealed (P <0.05. The system has been implemented as means of personal exposure to pollutants and environmental emissions were reduced 93.01% and 64.64%, respectively. Also, alone and integrated collection efficiency of cyclone and scrubber, were 94.2%, 59.05% and 97.4%, respectively. The results show good agreement with the values of the parameters ventilation system was designed. Conclusion: Implementation of integrated dust collectors is a good option in industries that have the financial and technical constraints to improve change processes and devices. This method with attainment to health and environmental standards not only can be resolve of the pollution problems, but also will be economically justified of such projects with reduction of depreciation expense and dust recycling.

  9. Studies of mobile dust in scrape-off layer plasmas using silica aerogel collectors

    Energy Technology Data Exchange (ETDEWEB)

    Bergsaker, H., E-mail: henricb@kth.se [Division of Space and Plasma Physics, Association EURATOM-VR, School of Electrical Engineering, Royal Institute of Technology KTH, SE-10044 Stockholm (Sweden); Ratynskaia, S. [Division of Space and Plasma Physics, Association EURATOM-VR, School of Electrical Engineering, Royal Institute of Technology KTH, SE-10044 Stockholm (Sweden); Litnovsky, A. [Institut fur Energieforschung - Plasmaphysik, Forschungszentrum Julich, Trilateral Euregio Cluster, Association EURATOM-FZ Julich, D-52425 Julich (Germany); Ogata, D. [Division of Space and Plasma Physics, Association EURATOM-VR, School of Electrical Engineering, Royal Institute of Technology KTH, SE-10044 Stockholm (Sweden); Sahle, W. [Functional Materials Division, KTH-Electrum 229, Isafjordsgatan 22, SE-16440 Stockholm (Sweden)

    2011-08-01

    Dust capture with ultralow density silica aerogel collectors is a new method, which allows time resolved in situ capture of dust particles in the scrape-off layers of fusion devices, without substantially damaging the particles. Particle composition and morphology, particle flux densities and particle velocity distributions can be determined through appropriate analysis of the aerogel surfaces after exposure. The method has been applied in comparative studies of intrinsic dust in the TEXTOR tokamak and in the Extrap T2R reversed field pinch. The analysis methods have been mainly optical microscopy and SEM. The method is shown to be applicable in both devices and the results are tentatively compared between the two plasma devices, which are very different in terms of edge plasma conditions, time scale, geometry and wall materials.

  10. Efficiency determination of an electrostatic lunar dust collector by discrete element method

    Science.gov (United States)

    Afshar-Mohajer, Nima; Wu, Chang-Yu; Sorloaica-Hickman, Nicoleta

    2012-07-01

    Lunar grains become charged by the sun's radiation in the tenuous atmosphere of the moon. This leads to lunar dust levitation and particle deposition which often create serious problems in the costly system deployed in lunar exploration. In this study, an electrostatic lunar dust collector (ELDC) is proposed to address the issue and the discrete element method (DEM) is used to investigate the effects of electrical particle-particle interactions, non-uniformity of the electrostatic field, and characteristics of the ELDC. The simulations on 20-μm-sized lunar particles reveal the electrical particle-particle interactions of the dust particles within the ELDC plates require 29% higher electrostatic field strength than that without the interactions for 100% collection efficiency. For the given ELDC geometry, consideration of non-uniformity of the electrostatic field along with electrical interactions between particles on the same ELDC geometry leads to a higher requirement of ˜3.5 kV/m to ensure 100% particle collection. Notably, such an electrostatic field is about 103 times less than required for electrodynamic self-cleaning methods. Finally, it is shown for a "half-size" system that the DEM model predicts greater collection efficiency than the Eulerian-based model at all voltages less than required for 100% efficiency. Halving the ELDC dimensions boosts the particle concentration inside the ELDC, as well as the resulting field strength for a given voltage. Though a lunar photovoltaic system was the subject, the results of this study are useful for evaluation of any system for collecting charged particles in other high vacuum environment using an electrostatic field.

  11. A New Modular Control Board for Pulse-Jet Cleaning of Dust Collector Filter Bags

    Directory of Open Access Journals (Sweden)

    L. Carosso

    2018-04-01

    Full Text Available This work presents a timing system modular control board to be used for pulse-jet cleaning of dust collector filter bags or pneumatic conveying systems. Many systems of this kind are already available on the market but only some of them have the ability to operate in full range alternating current power supplies. The presented versatile and innovative control board can control the electro valves, either the ones operating with alternating current and those in direct current (since they are both used in the industrial plants. For the same reason, the designed prototype system can be powered with different voltages, widening the number of potential industrial applications. The electronic board has as main advantage the ability to fully automate the cleaning cycle. It can drive many electro valves simultaneously since it is possible to connect more control boards together if needed. It also allows the user to separate the control section of the system from the section dedicated to the actuation of the electro valves. The electro valves can be controlled from a PC terminal via ethernet. The work describes the adopted solutions and the steps made for the design of the entire prototypal modular board, with particular focus on the innovative timing system.

  12. Evaluation of a Shaker Dust Collector for Use in a Recirculating Ventilation System.

    Science.gov (United States)

    Peters, Thomas M; Sawvel, Russell A; Park, Jae Hong; Anthony, T Renée

    2015-01-01

    General ventilation with recirculated air may be cost-effective to control the concentration of low-toxicity, contaminants in workplaces with diffuse, dusty operations, such as in agriculture. Such systems are, however, rarely adopted with little evidence showing improved air quality and ability to operate under harsh conditions. The goal of this work was to examine the initial and long-term performance of a fabric-filter shaker dust collector (SDC) in laboratory tests and as deployed within a recirculating ventilation system in an agricultural building. In laboratory tests, collection efficiency and pressure drop were tracked over several filter loading cycles, and the recovery of filter capacity (pressure drop) from filter shaking was examined. Collection efficiencies of particles larger than 5 μm was high (>95%) even when the filter was pristine, showing effective collection of large particles that dominate inhalable concentrations typical of agricultural dusts. For respirable-sized particles, collection efficiencies were low when the filter was pristine (e.g., 27% for 1 μm) but much higher when a dust cake developed on the filter (>99% for all size particles), even after shaking (e.g., 90% for 1 μm). The first shake of a filter was observed to recovery a substantial fraction of filter capacity, with subsequent shakes providing little benefit. In field tests, the SDC performed effectively over a period of three months in winter when incorporated in a recirculating ventilation system of a swine farrowing room. Trends in collection efficiency and pressure drop with loading were similar to those observed in the laboratory with overall collection efficiencies high (>80%) when pressure drop exceeded 230 Pa, or 23% of the maximum loading recommended by the manufacturer. This work shows that the SDC can function effectively over the harsh winter in swine rearing operations. Together with findings of improved air quality in the farrowing room reported in a

  13. Stardust Interstellar Preliminary Examination X: Impact Speeds and Directions of Interstellar Grains on the Stardust Dust Collector

    Science.gov (United States)

    Sterken, Veerle J.; Westphal, Andrew J.; Altobelli, Nicolas; Grun, Eberhard; Hillier, Jon K.; Postberg, Frank; Allen, Carlton; Stroud, Rhonda M.; Sandford, S. A.; Zolensky, Michael E.

    2014-01-01

    On the basis of an interstellar dust model compatible with Ulysses and Galileo observations, we calculate and predict the trajectories of interstellar dust (ISD) in the solar system and the distribution of the impact speeds, directions, and flux of ISD particles on the Stardust Interstellar Dust Collector during the two collection periods of the mission. We find that the expected impact velocities are generally low (less than 10 km per second) for particles with the ratio of the solar radiation pressure force to the solar gravitational force beta greater than 1, and that some of the particles will impact on the cometary side of the collector. If we assume astronomical silicates for particle material and a density of 2 grams per cubic centimeter, and use the Ulysses measurements and the ISD trajectory simulations, we conclude that the total number of (detectable) captured ISD particles may be on the order of 50. In companion papers in this volume, we report the discovery of three interstellar dust candidates in the Stardust aerogel tiles. The impact directions and speeds of these candidates are consistent with those calculated from our ISD propagation model, within the uncertainties of the model and of the observations.

  14. Evaluation of cost-effective dust collectors for single fireplaces and central heating boilers; Bewertung kostenguenstiger Staubabscheider fuer Einzelfeuerstaetten und Zentralheizungskessel

    Energy Technology Data Exchange (ETDEWEB)

    Kiener, Susanne; Turowski, Peter; Hartmann, Hans [Kompetenzzentrum fuer Nachwachsende Rohstoffe, Straubing (Germany). Technologie- und Foerderzentrum; Schmoeckel, Gerhard [Bayerisches Landesamt fuer Umwelt, Augsburg (Germany)

    2010-09-15

    The contribution under consideration reports on the performance of dust collectors for wood fires with respect to various parameters. Thus, the knowledge of the possibilities of the reduction of dust emissions should be improved by means of electrostatic deposition methods, and the assessment of practicability is to be enabled. To this end, several months of field testing of ten representative fireplaces was performed.

  15. Mitigation of soiling losses in solar collectors: Removal of surface-adhered dust particles using an electrodynamic screen

    Science.gov (United States)

    Sayyah, Arash

    Particulate contamination of the optical surfaces of solar collectors, often called "soiling", can have a significant deteriorating impact on energy yield due to the absorption and scattering of incident light. Soiling has more destructive effect on concentrated solar systems than on flat-plate photovoltaic panels, as the former are incapable of converting scattered sunlight. The first part of this thesis deals with the soiling losses of flat-plate photovoltaic (PV), concentrated solar power (CSP), and concentrated photovoltaic (CPV) systems in operation in several regions of the world. Influential parameters in dust accumulation losses, as well as different cleaning mechanisms in pursuit of restoring the efficiency of soiled systems, have been thoroughly investigated. In lieu of the most commonly-practiced manual cleaning method of using high-pressure water jets, the concept of automatic dust removal using the electrostatic forces of electrodynamic screen (EDS) technology is in a developmental stage and on its way toward commercialization. This thesis provides comprehensive analytical solutions for the electric potential and electric field distribution in EDS devices having different configurations. Numerical simulations developed using finite element analysis (FEA) software have corroborated the analytical solutions which can easily be embedded into software programs for particle trajectory simulations while also providing flexibility and generality in the study on the effect of different parameters of the EDS on the electric field and ensuing dust-removal performance. Evaluation and comparison of different repelling and attracting forces exerted on dust particles is of utmost importance to a detailed analysis of EDS performance in dust removal. Hence, the balance of electrostatic and adhesion forces, including van der Waals and capillary forces, have received significant attention in this dissertation. Furthermore, different numerical analyses have been

  16. Obtaining mathematical models for assessing efficiency of dust collectors using integrated system of analysis and data management STATISTICA Design of Experiments

    Science.gov (United States)

    Azarov, A. V.; Zhukova, N. S.; Kozlovtseva, E. Yu; Dobrinsky, D. R.

    2018-05-01

    The article considers obtaining mathematical models to assess the efficiency of the dust collectors using an integrated system of analysis and data management STATISTICA Design of Experiments. The procedure for obtaining mathematical models and data processing is considered by the example of laboratory studies on a mounted installation containing a dust collector in counter-swirling flows (CSF) using gypsum dust of various fractions. Planning of experimental studies has been carried out in order to reduce the number of experiments and reduce the cost of experimental research. A second-order non-position plan (Box-Bencken plan) was used, which reduced the number of trials from 81 to 27. The order of statistical data research of Box-Benken plan using standard tools of integrated system for analysis and data management STATISTICA Design of Experiments is considered. Results of statistical data processing with significance estimation of coefficients and adequacy of mathematical models are presented.

  17. Investigation of aerial dispersion of radioactive dust from an open-pit uranium mine by passive vinyl collectors

    International Nuclear Information System (INIS)

    Pettersson, H.B.; Koperski, J.

    1991-01-01

    Detailed investigations of the aerial dispersion of radioactive dust from the biggest open-pit U mining and milling operation in Australia were carried out. Spatial distributions of the long-lived radionuclides of 238 U series and their origin, i.e., mining and milling operations vs. natural background radiation, have been studied. Horizontal flux, dry deposition, and ground resuspension of the radionuclides were investigated along a 50-km transect in the direction of the prevailing monsoonal winds in the region. The study was performed by means of unconventional 'sticky vinyl' passive dust collectors, occasionally supported by high-volume air filter samplers. The data from the flux measurements show an inverse square to inverse cubic dependence, and the dry deposition exhibits an inverse square dependence, of radionuclide load vs. distance. The pit has been the predominant contributor of long-lived U series radionuclides to the environment within the radius of several kilometers from the operations. An aerial dispersion computer code (LUCIFER), based on a Gaussian plume model, was developed for the project. Experimental data were used as the code input data. Good agreement between the measured data and the normalized computed results was obtained

  18. An investigation into heat recovery from the surface of a cyclone dust collector attached to a downdraft biomass gasifier

    International Nuclear Information System (INIS)

    Nwokolo, Nwabunwanne; Mamphweli, Sampson; Makaka, Golden

    2016-01-01

    Highlights: • At a temperature of 450 °C–500 °C, hot syngas is regarded as a good heat carrier. • A significant quantity of energy (665893.07 kcal) is lost via the surface of the cyclone. • The surface temperature 150 °C–220 °C was within the low waste heat recovery temperature. - Abstract: The gas leaving the reactor of a downdraft biomass gasifier contains large quantities of heat energy; this is due to the fact that the gas passes through a hot bed of charcoal before leaving the reactor. This heat is normally wasted in the gas scrubber/cooler that cools it from between 400 °C–500 °C to ambient temperature (around 25 °C). The waste heat stream under consideration is the raw syngas that emanates from a gasification process in a downdraft gasifier situated at Melani Village, Eastern Cape. This loss of heat is undesirable as it impacts on the thermal efficiency of the system. This study investigates the feasibility of heat recovery from the surface of the cyclone dust collector prior to entering the gas scrubber. It was shown that there was a downward decrease in temperature along the length of the cyclone. It is found that the total quantity of heat contained in the gas was 665893.07 kcal, which could indicate the viability of recovering heat from the cyclone.

  19. Comparison of Air Impaction and Electrostatic Dust Collector Sampling Methods to Assess Airborne Fungal Contamination in Public Buildings.

    Science.gov (United States)

    Normand, Anne-Cécile; Ranque, Stéphane; Cassagne, Carole; Gaudart, Jean; Sallah, Kankoé; Charpin, Denis-André; Piarroux, Renaud

    2016-03-01

    Many ailments can be linked to exposure to indoor airborne fungus. However, obtaining a precise measurement of airborne fungal levels is complicated partly due to indoor air fluctuations and non-standardized techniques. Electrostatic dust collector (EDC) sampling devices have been used to measure a wide range of airborne analytes, including endotoxins, allergens, β-glucans, and microbial DNA in various indoor environments. In contrast, viable mold contamination has only been assessed in highly contaminated environments such as farms and archive buildings. This study aimed to assess the use of EDCs, compared with repeated air-impactor measurements, to assess airborne viable fungal flora in moderately contaminated indoor environments. Indoor airborne fungal flora was cultured from EDCs and daily air-impaction samples collected in an office building and a daycare center. The quantitative fungal measurements obtained using a single EDC significantly correlated with the cumulative measurement of nine daily air impactions. Both methods enabled the assessment of fungal exposure, although a few differences were observed between the detected fungal species and the relative quantity of each species. EDCs were also used over a 32-month period to monitor indoor airborne fungal flora in a hospital office building, which enabled us to assess the impact of outdoor events (e.g. ground excavations) on the fungal flora levels on the indoor environment. In conclusion, EDC-based measurements provided a relatively accurate profile of the viable airborne flora present during a sampling period. In particular, EDCs provided a more representative assessment of fungal levels compared with single air-impactor sampling. The EDC technique is also simpler than performing repetitive air-impaction measures over the course of several consecutive days. EDC is a versatile tool for collecting airborne samples and was efficient for measuring mold levels in indoor environments. © The Author 2015

  20. Stardust Interstellar Preliminary Examination IV: Scanning Transmission X-Ray Microscopy Analyses of Impact Features in the Stardust Interstellar Dust Collector

    Science.gov (United States)

    Butterworth, Anna L.; Westphal, Andrew J.; Frank, David R.; Allen, Carlton C.; Bechtel, Hans A.; Sandford, Scott A.; Tsou, Peter; Zolensky, Michael E.

    2014-01-01

    We report the quantitative characterization by synchrotron soft X-ray spectroscopy of 31 potential impact features in the aerogel capture medium of the Stardust Interstellar Dust Collector. Samples were analyzed in aerogel by acquiring high spatial resolution maps and high energy-resolution spectra of major rock-forming elements Mg, Al, Si, Fe, and others. We developed diagnostic screening tests to reject spacecraft secondary ejecta and terrestrial contaminants from further consideration as interstellar dust candidates. The results support an extraterrestrial origin for three interstellar candidates: I1043,1,30 (Orion) is a 3 pg particle with Mg-spinel, forsterite, and an iron-bearing phase. I1047,1,34 (Hylabrook) is a 4 pg particle comprising an olivine core surrounded by low-density, amorphous Mg-silicate and amorphous Fe, Cr, and Mn phases. I1003,1,40 (Sorok) has the track morphology of a high-speed impact, but contains no detectable residue that is convincingly distinguishable from the background aerogel. Twenty-two samples with an anthropogenic origin were rejected, including four secondary ejecta from impacts on the Stardust spacecraft aft solar panels, nine ejecta from secondary impacts on the Stardust Sample Return Capsule, and nine contaminants lacking evidence of an impact. Other samples in the collection included I1029,1,6, which contained surviving solar system impactor material. Four samples remained ambiguous: I1006,2,18, I1044,2,32, and I1092,2,38 were too dense for analysis, and we did not detect an intact projectile in I1044,3,33. We detected no radiation effects from the synchrotron soft X-ray analyses; however, we recorded the effects of synchrotron hard X-ray radiation on I1043,1,30 and I1047,1,34.

  1. Magnetic collectors

    International Nuclear Information System (INIS)

    Frew, J.D.

    1980-01-01

    A collector for use in a magnetic separator is formed by isostatically pressing a metal which is resistant to attack by acid about ferromagnetic bodies whereby to encase the bodies in the metal. In one arrangement, as shown, the bodies are encapsulated between inner and outer cylinders. In other arrangements the encapsulating metal is in the form of a tube or planar sheets. The bodies are of Fe or an oxide thereof and the acid-resistant metal parts may be of stainless steel, Au, Pt, Pa or an alloy. The magnetic separator is intended for use in removing particles from liquids during the reprocessing of nuclear fuel materials. (author)

  2. Energy savings in dust collector plants of bag house filter type. Phase 1 - Literature study; Energieffektivisering av anlaeggningar foer stoftrening med slangfilter. Etapp 1-Litteraturstudie

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Lars; Wikman, Karin; Berg, Magnus [AaF-Energi and Miljoe AB, Stockholm (Sweden)

    2004-01-01

    The largest energy demands in connection with the operation of bag house filters are the electric energy consumption for the fans, securing the flow of flue gas through the filter, and the electric energy consumption when producing the pressurized air (compressors or high pressure fans). Considering the significantly increased fan work when having a non-optimised cleaning of the filters, it seems justified to investigate the possibilities to minimise the unnecessary pressure drop. There is also a saving potential in the filter cleaning process, which otherwise may cost an unacceptable amount of pressurized air or other energy. The main purpose of this work is to develop methods to optimize the operation of bag house filters, which is started up with this report containing a follow-up of what has been done in Denmark and a confirmation of the technology status. In the next step, a case study where two-three plants are examined more in detail is suggested followed by a potential study to estimate the total energy saving potential in Sweden. Dust precipitation with bag house filters is basically a rather simple technique, which has existed in flue gas cleaning for about 50 years. From the literature study it can be established that there has been no revolutionary development in the field, but there are some work being done mainly to introduce new filter material but also to optimise the use of bag house filters with new computer based control systems. The largest potential of energy saving prevails if the filter from the beginning is overloaded, which usually is the case. The reason for overload may be a too large volume flow in relation to the filter area, that the dust has penetrated and blocked the filter, a defective filter cleaning process or that wrong filter material has been chosen. In Denmark a study has been made with the purpose to investigate the possibilities to optimise the energy consumption for bag house filters. For the three plants studied, an

  3. Garbage collector interface

    OpenAIRE

    Ive, Anders; Blomdell, Anders; Ekman, Torbjörn; Henriksson, Roger; Nilsson, Anders; Nilsson, Klas; Robertz, Sven

    2002-01-01

    The purpose of the presented garbage collector interface is to provide a universal interface for many different implementations of garbage collectors. This is to simplify the integration and exchange of garbage collectors, but also to support incremental, non-conservative, and thread safe implementations. Due to the complexity of the interface, it is aimed at code generators and preprocessors. Experiences from ongoing implementations indicate that the garbage collector interface successfully ...

  4. Connectable solar air collectors

    Energy Technology Data Exchange (ETDEWEB)

    Oestergaard Jensen, S.; Bosanac, M.

    2002-02-01

    The project has proved that it is possible to manufacture solar air collector panels, which in an easy way can be connected into large collector arrays with integrated ducting without loss of efficiency. The developed connectable solar air collectors are based on the use of matrix absorbers in the form of perforated metal sheets. Three interconnected solar air collectors of the above type - each with an transparent area of approx. 3 m{sup 2} - was tested and compared with parallel tests on two single solar air collectors also with a transparent area of approx. 3 m{sup 2} One of the single solar air collectors has an identical absorber as the connectable solar air collectors while the absorber of the other single solar air collector was a fibre cloth. The efficiency of the three solar air collectors proved to be almost identical in the investigated range of mass flow rates and temperature differences. The solar air collectors further proved to be very efficient - as efficient as the second most efficient solar air collectors tested in the IEA task 19 project Solar Air Systems. Some problems remain although to be solved: the pressure drop across especially the connectable solar air collectors is too high - mainly across the inlets of the solar air collectors. It should, however, be possible to considerably reduce the pressure losses with a more aerodynamic design of the inlet and outlet of the solar air collectors; The connectable solar air collectors are easy connectable but the air tightness of the connections in the present form is not good enough. As leakage leads to lower efficiencies focus should be put on making the connections more air tight without loosing the easiness in connecting the solar air collectors. As a spin off of the project a simple and easy way to determine the efficiency of solar, air collectors for pre-heating of fresh air has been validated. The simple method of determining the efficiency has with success been compared with an advance method

  5. Air/liquid collectors

    DEFF Research Database (Denmark)

    Jensen, Søren Østergaard; Olesen, Ole; Kristiansen, Finn Harken

    1997-01-01

    this kind of collectors. The modified simulation program has been used for the determination of the surplus in performance which solar heating systems with this type of solar collectors for combined preheating of ventilation air and domestic hot water will have. The simulation program and the efficiency......This report determine efficiency equations for combined air/liquid solar collectors by measurements on to different air/liquid collectors. Equations which contain all relevant informations on the solar collectors. A simulation program (Kviksol) has been modified in order to be able to handle...

  6. Radiation energy collector

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Bei Tse; Rabl, A

    1977-02-10

    The invention deals with a concentrating solar collector. Collectors of this kind often have considerable natural convection losses which are due, among other facts, to the location of the energy absorber at the outlet with the heated surface of the absorber facing the inlet opening of the collector. According to the invention, the collector is designed in such manner that the absorber is located inside a space in such a way that the radiation emitted by the absorber is reflected back to the absorber with the aid of mirror surfaces. Various designs are described.

  7. Analytical analysis of solar thermal collector with glass and Fresnel lens glazing

    Science.gov (United States)

    Zulkifle, Idris; Ruslan, Mohd Hafidz Hj; Othman, Mohd Yusof Hj; Ibarahim, Zahari

    2018-04-01

    Solar thermal collector is a system that converts solar radiation to heat. The heat will raise the temperature higher than the ambient temperature. Absorber and glazing are two important components in order to increase the temperature of the collector. The thermal absorber will release heat by convection and as radiation to the surrounding. These losses will be reduced by glazing. Other than that, glazing is beneficial for protecting the collector from dust and water. This study discusses about modelling of solar thermal collector effects of different mass flow rates with different glazing for V-groove flat plate solar collectors. The glazing used was the glass and linear Fresnel lens. Concentration ratio in this modelling was 1.3 for 0.1m solar collector thickness. Results show that solar collectors with linear Fresnel lens has the highest efficiency value of 71.18% compared to solar collectors with glass which has efficiency 54.10% with same operation conditions.

  8. Solar collector overheating protection

    NARCIS (Netherlands)

    Slaman, M.J.; Griessen, R.P.

    Prismatic structures in a thermal solar collector are used as overheating protection. Such structures reflect incoming light efficiently back whenever less thermal power is extracted from the solar collector. Maximum thermal power is generated when the prismatic structure is surrounded by a

  9. City sewer collectors biocorrosion

    Science.gov (United States)

    Ksiażek, Mariusz

    2014-12-01

    This paper presents the biocorrosion of city sewer collectors impregnated with special polymer sulphur binders, polymerized sulphur, which is applied as the industrial waste material. The city sewer collectors are settled with a colony of soil bacteria which have corrosive effects on its structure. Chemoautotrophic nitrifying bacteria utilize the residues of halites (carbamide) which migrate in the city sewer collectors, due to the damaged dampproofing of the roadway and produce nitrogen salts. Chemoorganotrophic bacteria utilize the traces of organic substrates and produce a number of organic acids (formic, acetic, propionic, citric, oxalic and other). The activity of microorganisms so enables the origination of primary and secondary salts which affect physical properties of concretes in city sewer collectors unfavourably.

  10. ADVANCED HYBRID PARTICULATE COLLECTOR

    Energy Technology Data Exchange (ETDEWEB)

    Ye Zhuang; Stanley J. Miller; Michelle R. Olderbak; Rich Gebert

    2001-12-01

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the U.S. Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in an entirely novel manner. The AHPC concept combines fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two methods, both in the particulate collection step and in transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and solves the problem of reentrainment and re-collection of dust in conventional baghouses. Phase I of the development effort consisted of design, construction, and testing of a 5.7-m{sup 3}/min (200-acfm) working AHPC model. Results from both 8-hr parametric tests and 100-hr proof-of-concept tests with two different coals demonstrated excellent operability and greater than 99.99% fine-particle collection efficiency. Since all of the developmental goals of Phase I were met, the approach was scaled up in Phase II to a size of 255 m{sup 3}/min (9000 acfm) (equivalent in size to 2.5 MW) and was installed on a slipstream at the Big Stone Power Plant. For Phase II, the AHPC at Big Stone Power Plant was operated continuously from late July 1999 until mid-December 1999. The Phase II results were highly successful in that ultrahigh particle collection efficiency was achieved, pressure drop was well controlled, and system operability was excellent. For Phase III, the AHPC was modified into a more compact configuration, and components were installed that were closer to what would be used in a full-scale commercial design. The modified AHPC was operated from April to July 2000. While operational results were acceptable during this time, inspection of bags in the summer of 2000 revealed some membrane damage to the fabric that appeared to be

  11. Tracking system for solar collectors

    Science.gov (United States)

    Butler, B.

    1980-10-01

    A tracking system is provided for pivotally mounted spaced-apart solar collectors. A pair of cables is connected to spaced-apart portions of each collector, and a driver displaces the cables, thereby causing the collectors to pivot about their mounting, so as to assume the desired orientation. The collectors may be of the cylindrical type as well as the flat-plate type. Rigid spar-like linkages may be substituted for the cables. Releasable attachments of the cables to the collectors is also described, as is a fine tuning mechanism for precisely aligning each individual collector.

  12. Biological sample collector

    Science.gov (United States)

    Murphy, Gloria A [French Camp, CA

    2010-09-07

    A biological sample collector is adapted to a collect several biological samples in a plurality of filter wells. A biological sample collector may comprise a manifold plate for mounting a filter plate thereon, the filter plate having a plurality of filter wells therein; a hollow slider for engaging and positioning a tube that slides therethrough; and a slide case within which the hollow slider travels to allow the tube to be aligned with a selected filter well of the plurality of filter wells, wherein when the tube is aligned with the selected filter well, the tube is pushed through the hollow slider and into the selected filter well to sealingly engage the selected filter well and to allow the tube to deposit a biological sample onto a filter in the bottom of the selected filter well. The biological sample collector may be portable.

  13. A solar energy collector

    Energy Technology Data Exchange (ETDEWEB)

    Vasil' yev, L.L.; Avakyan, Yu.V.; Bogdanov, V.M.; Gagiyan, L.A.; Grakovich, L.P.; Karapetyan, G.S.; Morgun, V.A.

    1984-01-01

    A collector whose primary component is a heating pipe is proposed. The evaporation zone located in the lower half of the heating pipe has an external absorption coating. Chambers that open upward and contain the evaporating fluid are mounted within this region along the top. In order to improve operational reliability of the collector, these chambers are mounted on one coated wall; the area of projection of each of the chambers onto the horizontal plane is greater than the area of the projection of each of the chambers placed above it. The coating may be in the form of photocells; a filter is mounted on the chamber side inside the evaporation zone. The evaporation zone may take the form of a cylinder with a segmented base; the photocells are mounted on a flat section of the lateral surface. The collector may be used to cool the photocells.

  14. Respirable quartz hazard associated with coal mine roof bolter dust

    International Nuclear Information System (INIS)

    Joy, G.J.; Beck, T.W.; Listak, J.M.

    2010-01-01

    Pneumoconiosis has been reported to be increasing among underground coal miners in the Southern Appalachian Region. The National Institute for Occupational Safety and Health conducted a study to examine the particle size distribution and quartz content of dust generated by the installation of roof bolts in mines. Forty-six bulk samples of roof bolting machine pre-cleaner cyclone dump dust and collector box dust were collected from 26 underground coal mines. Real-time and integrated airborne respirable dust concentrations were measured on 3 mining sections in 2 mines. The real-time airborne dust concentrations profiles were examined to identify any concentration changes that might be associated with pre-cleaner cyclone dust discharge events. The study showed that bolter dust is a potential inhalation hazard due to the fraction of dust less than 10 μm in size, and the quartz content of the dust. The pre-cleaner cyclone dust was significantly larger than the collector box dust, indicating that the pre-cleaner functioned properly in removing the larger dust size fraction from the airstream. However, the pre-cleaner dust still contained a substantial amount of respirable dust. It was concluded that in order to maintain the effectiveness of a roof bolter dust collector, periodic removal of dust is required. Appropriate work procedures and equipment are necessary to minimize exposure during this cleaning task. 13 refs., 3 tabs., 2 figs.

  15. Novel diagnostics for dust in space, Laboratory and fusion plasmas

    International Nuclear Information System (INIS)

    Castaldo, C.

    2011-01-01

    In situ diagnostics for mobile dust, based on dust impact ionization phenomena, as well as silica aerogel dust collectors are discussed for applications to space and fusion plasmas. The feasibility of an electro-optical probe to detect hypervelocity (>1 km/s) dust particles in tokamaks is evaluated. For quiescent plasmas, a diagnostic of submicron dust based on measurements of plasma fluctuation spectra can be used (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Solar collector manufacturing activity, 1990

    International Nuclear Information System (INIS)

    1992-01-01

    The Solar Collector Manufacturing Activity 1990 report prepared by the Energy Information Administration (EIA) presents summary and detailed data provided by domestic manufacturers on shipments of solar thermal collectors and photovoltaic cells and modules. Summary data on solar thermal collector shipments are presented for the period 1974 through 1990. Summary data on photovoltaic cell and module shipments are presented for the period 1982 through 1990. Detailed information for solar thermal collectors and photovoltaic cells and modules are presented for 1990

  17. Solar energy collector

    Science.gov (United States)

    Brin, Raymond L.; Pace, Thomas L.

    1978-01-01

    The invention relates to a solar energy collector comprising solar energy absorbing material within chamber having a transparent wall, solar energy being transmitted through the transparent wall, and efficiently absorbed by the absorbing material, for transfer to a heat transfer fluid. The solar energy absorbing material, of generally foraminous nature, absorbs and transmits the solar energy with improved efficiency.

  18. Flat plate collector. Solarflachkollektor

    Energy Technology Data Exchange (ETDEWEB)

    Raab, N

    1979-03-29

    The invention refers to a flat solar collector with an absorber plate, which is arranged on a support and is covered by a transparent window, between which and the plate there is an air space. The previously known structures of this type had the disadvantage that the thermal expansion of the enclosed air caused considerable difficulties. The purpose of the invention is therefore to create a collector, which can be used on the modular system, retains its properties and is safe in spite of the great temperature variations. According to the invention this problem is solved by providing a compensating space in the collector, which is separated by a diaphragm from the airspace between the plate and the covering window. The airspace therefore remains sealed against the atmosphere, so that no dirt, corrosion of the inside and no condensation can reduce the efficiency of the collector. A rise in pressure due to an increase in temperature is immediately reduced by expansion of the diaphragm, which enters the compensation space. In order to increase the pressure in the airspace above the plate for increases in temperature, the compensation space is connected to the atmosphere. The diaphragm can be mirrored on the side towards the absorber, which makes the diaphragm into an insulating element, as it reflects radiated heat from the absorber.

  19. Study on treatment of dust by dismantling

    International Nuclear Information System (INIS)

    Torikai, K.; Suzuki, K.

    1987-01-01

    In dismantling of nuclear reactors, various kinds of treatment of dust generated by cutting or dismantling concrete structures of components of reactors are evaluated for safety, cost, and performance comparing the work in air with water. A method of dust treatment for work in air is discussed. The dry method has an easy operation in practice and a good performance in the equipment, but has problem on the prevention from radioactive contamination by diffusion of dust in air. For the purpose of advancing the strong points and eliminating the weak points in dry method, an improved venturi scrubber system is proposed for dismantling work as a dust collecting system. The system consists of dust absorbing pipe, dust collector, separator of dust and water and dust transfer equipment to a storage of waste. This system would be expected to have better performance and lower operating cost in decommissioning nuclear reactors, especially, the number of dust filters, for example, HEPA filters, will be considerably saved

  20. Solar collector array

    Science.gov (United States)

    Hall, John Champlin; Martins, Guy Lawrence

    2015-09-06

    A method and apparatus for efficient manufacture, assembly and production of solar energy. In one aspect, the apparatus may include a number of modular solar receiver assemblies that may be separately manufactured, assembled and individually inserted into a solar collector array housing shaped to receive a plurality of solar receivers. The housing may include optical elements for focusing light onto the individual receivers, and a circuit for electrically connecting the solar receivers.

  1. Turning collectors for solar radiation

    Science.gov (United States)

    Barak, Amitzur Z.

    1976-01-01

    A device is provided for turning a solar collector about the polar axis so that the collector is directed toward the sun as the sun tracks the sky each day. It includes two heat-expansive elements and a shadow plate. In the morning a first expansive element is heated, expands to turn the collector to face the sun, while the second expansive element is shaded by the plate. In the afternoon the second element is heated, expands to turn the collector to face the sun, while the first is shaded by the plate.

  2. The CERN antiproton collector

    International Nuclear Information System (INIS)

    Autin, B.

    1984-01-01

    The Antiproton Collector is a new ring of much larger acceptance than the present accumulator. It is designed to receive 10 8 antiprotons per PS cycle. In order to be compatible with the Antiproton Accumulator, the momentum spread and the emittances are reduced from 6% to 0.2% and from 200 π mm mrad to 25 π mm mrad respectively. In addition to the ring itself, the new target area and the modifications to the stochastic systems of the Antiproton Accumulator are described. (orig.)

  3. The PKI collector

    Science.gov (United States)

    Rice, M. P.

    1982-07-01

    The design and manufacturing of a solar thermal collector is discussed. The collector has three primary subsystems: concentrator, receiver/fluid loop, and controls. Identical curved reflective columns are utilized in a faceted Fresnel design to support 864 one foot square flat inexpensive second-surface, silvered glass mirrors. The columns are ganged together and rotated through their centers of gravity to provide elevation tracking. The concentrator is supported by a lightweight spaceframe structure which distributes all wind and gravity loads to the base supports. The base of the structure is a track which rotates on wheels mounted on concrete piers. A parallel tube steel heat exchanger is mounted at the concentrator focal area in a well insulated, galvanized steel housing. Two rows of vertical close-packed, staggered tubes connect a mud header and a steam header. Automatic two axis tracking and operational control is provided with a microprocessor based package. Concentrator-mounted shadowbands are the basis for active tracking. A software program provides azimuthal tracking during cloudy periods.

  4. Modelling of Microclimate in collectors

    DEFF Research Database (Denmark)

    Holck, Ole

    1996-01-01

    Abstract It is important to avoid condensation in solar collectors, most of all because wetness of the absorber can damage the selective surface and cause corrosion on the absorber plate. During night time the cover of collectors will cool below ambient temperature due to thermal radiation...

  5. LHCb Tag Collector

    International Nuclear Information System (INIS)

    Fernández, Paloma Fuente; Clemencic, Marco; Cousin, Nicolas

    2011-01-01

    The LHCb physics software consists of hundreds of packages, each of which is developed by one or more physicists. When the developers have some code changes that they would like released, they commit them to the version control system, and enter the revision number into a database. These changes have to be integrated into a new release of each of the physics analysis applications. Tests are then performed by a nightly build system, which rebuilds various configurations of the whole software stack and executes a suite of run-time functionality tests. A Tag Collector system has been developed using solid standard technologies to cover both the use cases of developers and integration managers. A simple Web interface, based on an AJAX-like technology, is available. Integration with SVN and Nightly Build System, is possible via a Python API. Data are stored in a relational database with the help of an ORM (Object-Relational Mapping) library.

  6. Advanced evacuated tube collectors

    Science.gov (United States)

    Schertz, W. W.; Hull, J. R.; Winston, R.; Ogallagher, J.

    1985-04-01

    The essence of the design concept for these new collectors is the integration of moderate levels of nonimaging concentration inside the evacuated tube itself. This permanently protects the reflection surfaces and allows the use of highly reflecting front surface mirrors with reflectances greater than 95%. Previous fabrication and long term testing of a proof-of-concept prototype has established the technical success of the concept. Present work is directed toward the development of a manufacturable unit that will be suitable for the widest possible range of applications. Design alternatives include scaling up the original prototype's tube diameter from 5 cm to 10 cm, using an internal shaped metal concentrating reflector, using a variety of profile shapes to minimize so-called gap losses and accommodate both single ended and double-ended flow geometries, and allowing the use of heat pipes for the absorber tube.

  7. Current collectors for improved safety

    Science.gov (United States)

    Abdelmalak, Michael Naguib; Allu, Srikanth; Dudney, Nancy J.; Li, Jianlin; Simunovic, Srdjan; Wang, Hsin

    2017-12-19

    A battery electrode assembly includes a current collector with conduction barrier regions having a conductive state in which electrical conductivity through the conduction barrier region is permitted, and a safety state in which electrical conductivity through the conduction barrier regions is reduced. The conduction barrier regions change from the conductive state to the safety state when the current collector receives a short-threatening event. An electrode material can be connected to the current collector. The conduction barrier regions can define electrical isolation subregions. A battery is also disclosed, and methods for making the electrode assembly, methods for making a battery, and methods for operating a battery.

  8. AEROSOL PARTICLE COLLECTOR DESIGN STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Richard Dimenna, R

    2007-09-27

    A computational evaluation of a particle collector design was performed to evaluate the behavior of aerosol particles in a fast flowing gas stream. The objective of the work was to improve the collection efficiency of the device while maintaining a minimum specified air throughput, nominal collector size, and minimal power requirements. The impact of a range of parameters was considered subject to constraints on gas flow rate, overall collector dimensions, and power limitations. Potential improvements were identified, some of which have already been implemented. Other more complex changes were identified and are described here for further consideration. In addition, fruitful areas for further study are proposed.

  9. Four-collector flux sensor

    International Nuclear Information System (INIS)

    Wiegand, W.J. Jr.; Bullis, R.H.; Mongeon, R.J.

    1980-01-01

    A flowmeter based on ion drift techniques was developed for measuring the rate of flow of a fluid through a given cross-section. Ion collectors are positioned on each side of an immediately adjacent to ion source. When air flows axially through the region in which ions are produced and appropriate electric fields are maintained between the collectors, an electric current flows to each collector due to the net motion of the ions. The electric currents and voltages and other parameters which define the flow are combined in an electric circuit so that the flux of the fluid can be determined. (DN)

  10. New collectors from all over the world

    Energy Technology Data Exchange (ETDEWEB)

    Augsten, Eva

    2008-07-01

    Flat-plate collectors are fashionable, even among customers in Shanghai, although China is considered the land of evacuated tubes. Elsewhere, fashion is also a consideration, which partly explains the switch from fin collectors to full-surface collectors. Sun and Wind Energy has put together a list of new collectors from various countries. (orig.)

  11. Design package for concentrating solar collector panels

    Energy Technology Data Exchange (ETDEWEB)

    1978-08-01

    Information used to evaluate the design of the Northrup concentrating collector is presented. Included are the system performance specifications, the applications manual, and the detailed design drawings of the collector. The Northrup concentrating solar collector is a water/glycol/working fluid type, dipped galvanized steel housing, transparent acrylic Fresnel lens cover, copper absorber tube, fiber glass insulation and weighs 98 pounds. The gross collector area is about 29.4/sup 2/ per collector. A collector assembly includes four collector units within a tracking mount array.

  12. Solar radiation on a catenary collector

    Science.gov (United States)

    Crutchik, M.; Appelbaum, J.

    1992-01-01

    A tent-shaped structure with a flexible photovoltaic blanket acting as a catenary collector is presented. The shadow cast by one side of the collector produces a shadow on the other side of the collector. This self-shading effect is analyzed. The direct beam, the diffuse, and the albedo radiation on the collector are determined. An example is given for the insolation on the collector operating on Viking Lander 1 (VL1).

  13. Design package for concentrating solar collector panels

    Science.gov (United States)

    1978-01-01

    Information used to evaluate the design of the Northrup concentrating collector is presented. Included are the system performance specifications, the applications manual, and the detailed design drawings of the collector. The collector is a water/glycol/working fluid type, with a dipped galvanized steel housing, transparent acrylic Fresnel lens cover, copper absorber tube, and fiber glass insulation. It weights 98 pounds. A collector assembly includes four collector units within a tracking mount array.

  14. A distributed garbage collector for active objects

    OpenAIRE

    Puaut , Isabelle

    1993-01-01

    This paper introduces an algorithm that performs garbage collection in distributed systems of active objects (i.e., objects having their own threads of control). The proposed garbage collector is made of a set of local garbage collectors, one per node, loosely coupled to a global garbage collector. The novelties of the proposed garbage collector come from the fact that local garbage collectors need not be synchronized with each other for detecting garbage objects and that faulty communication...

  15. Project 'Colored solar collectors' - Annual report 2005

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, A.; Chambrier, E. De; Roecker, Ch.; Scartezzini, J. -L.

    2005-12-15

    The architectural integration of thermal solar collectors into buildings is often limited by their black color, and the visibility of tubes and corrugations of the absorber sheets. A certain freedom in color choice would be desirable, but the colored appearance should not cause excessive performance degradation. Multilayered thin film interference filters on the collector glazing can produce a colored reflection, hiding the corrugated metal sheet, while transmitting the non-reflected radiation entirely to the absorber. These interference filters are designed and optimized by numerical simulation and shall be manufactured by the sol-gel dip-coating process. The proposed colored glazed solar collectors will be ideally suited for architectural integration into buildings, e.g. as solar active glass facades. The availability of thin film materials with a refractive index lower than that of silicon favors a higher solar transmission at a given value of visible reflectance. The feasibility of the sol-gel deposition of such low refractive index materials has been demonstrated. For the development of nanostructured materials, analytical methods such as electron microscopy are extremely helpful. Important techniques of substrate pretreatment, sample cleaving, polishing, mounting, and microscope handling have been acquired. First measurements yield images of nanostructures produced by the sol-gel dip-coating process. Nanocomposite Ti{sub x}Si{sub 1-x}O{sub 2} thin films provide a large range of refractive indices. Aiming a high efficiency of the colored reflection, Ti{sub x}Si{sub 1-x}O{sub 2} based multilayered coatings have been designed and subsequently prepared by sol-gel dip-coating. The energy efficiency M = R{sub VIS}/(100%-T{sub sol}) of the obtained colored reflection amounts up to 2.4. For a convincing demonstration sufficiently large samples of high quality are imperatively needed. An infrastructure for the handling of A4 sized samples has been established

  16. Performance of evaporator-collector and air collector in solar assisted heat pump dryer

    International Nuclear Information System (INIS)

    Hawlader, M.N.A.; Rahman, S.M.A.; Jahangeer, K.A.

    2008-01-01

    A solar assisted heat pump dryer has been designed, fabricated and tested. This paper presents the performance of the evaporator-collector and the air collector when operated under the same meteorological conditions. ASHRAE standard procedure for collector testing has been followed. The evaporator-collector of the heat pump is acting directly as the solar collector, and the temperature of the refrigerant at the inlet to the evaporator-collector always remained below the ambient temperature. Because of the rejection of sensible and latent heats of air at the dehumidifier, the temperature at the inlet to the air collector is lower than that of the ambient air. Hence, the thermal efficiency of the air collector also increases due to a reduction of losses from the collector. The efficiencies of the evaporator-collector and the air collector were found to vary between 0.8-0.86 and 0.7-0.75, respectively, when operated under the meteorological conditions of Singapore

  17. Wood Dust

    Science.gov (United States)

    Learn about wood dust, which can raise the risk of cancers of the paranasal sinuses and nasal cavity. High amounts of wood dust are produced in sawmills, and in the furniture-making, cabinet-making, and carpentry industries.

  18. Installation package for concentrating solar collector panels

    Science.gov (United States)

    1978-01-01

    The concentrating solar collector panels comprise a complete package array consisting of collector panels using modified Fresnel prismatic lenses for a 10 to 1 concentrating ratio, supporting framework, fluid manifolding and tracking drive system, and unassembled components for field erection.

  19. Investigations on efficiencies of HT solar collectors for different flow rates and collector tilts

    DEFF Research Database (Denmark)

    Chen, Ziqian; Perers, Bengt; Furbo, Simon

    2013-01-01

    Two HT solar collectors for solar heating plants from Arcon Solvarme A/S are tested in a laboratory test facility for solar collectors at Technical University of Denmark (DTU). The collectors are designed in the same way. However, one solar collector is equipped with an ETFE foil between the abso......Two HT solar collectors for solar heating plants from Arcon Solvarme A/S are tested in a laboratory test facility for solar collectors at Technical University of Denmark (DTU). The collectors are designed in the same way. However, one solar collector is equipped with an ETFE foil between...... the absorber and the cover glass and the other is without ETFE foil. The efficiencies for the collectors are tested at different flow rates and tilt. On the basis of the measured efficiencies, the efficiencies for the collectors as functions of flow rates are obtained. The calculated efficiencies are in good...

  20. THERMAL PERFORMANCE OF FLAT PLATE SOLAR COLLECTOR

    Directory of Open Access Journals (Sweden)

    TABET I.

    2017-06-01

    Full Text Available In this paper, a theoretical and experimental studyof flat platesolar water collector with reflectors.A mathematical model based on energy balance equations saw the thermal behavior of the collector is investigated. The experimental test was made at the unit research applies in renewable energy (URAER located in southern Algeria.An increase of 23% for solar radiation incident on the collector surface with the addition of the planers reflectors in the day of May, this increase causes an improvement of the performance of the collector,the fluid temperature increases with an average of 5%. Thetests conducted on the flat plate solar water collector in open circuit enabled the determination of thermal performance of the collector by estimating the daily output The thermal efficiency of the collector ranges from 1% -63% during the day, a mean value of 36%obtained.

  1. Continuous dust monitoring in headings in underground coal mines

    Directory of Open Access Journals (Sweden)

    Kazimierz Lebecki

    2016-01-01

    Full Text Available The article presents hazardous conditions of airborne dust based on the results of measurements of dust concentration taken at work-places at a underground rock-coal face drilled by a heading machine with combined ventilation (suction and forced ventilation with dust collector. The measurements were taken using three methods in order to examine and assess the actual conditions within the excavation subject to the study. The measurement results and conclusions show major difficulties in achieving MAC levels. Research conclusions indicate the low efficiency of collective and personal measures applied to protect against dust harmful to health as well as the need to improve them.

  2. Collector ring project at FAIR

    International Nuclear Information System (INIS)

    Dolinskii, A; Blell, U; Dimopoulou, C; Gorda, O; Leibrock, H; Litvinov, S; Laier, U; Schurig, I; Weinrich, U; Berkaev, D; Koop, I; Starostenko, A; Shatunov, P

    2015-01-01

    The collector ring is a dedicated ring for fast cooling of ions coming from separators at the FAIR project. To accommodate optimal technical solutions, a structure of a magnet lattice was recently reviewed and modified. Consequently, more appropriate technical solutions for the main magnets could be adopted. A general layout and design of the present machine is shown. The demanding extraction schemes have been detailed and open design issues were completed. (paper)

  3. Cometary Dust

    Science.gov (United States)

    Levasseur-Regourd, Anny-Chantal; Agarwal, Jessica; Cottin, Hervé; Engrand, Cécile; Flynn, George; Fulle, Marco; Gombosi, Tamas; Langevin, Yves; Lasue, Jérémie; Mannel, Thurid; Merouane, Sihane; Poch, Olivier; Thomas, Nicolas; Westphal, Andrew

    2018-04-01

    This review presents our understanding of cometary dust at the end of 2017. For decades, insight about the dust ejected by nuclei of comets had stemmed from remote observations from Earth or Earth's orbit, and from flybys, including the samples of dust returned to Earth for laboratory studies by the Stardust return capsule. The long-duration Rosetta mission has recently provided a huge and unique amount of data, obtained using numerous instruments, including innovative dust instruments, over a wide range of distances from the Sun and from the nucleus. The diverse approaches available to study dust in comets, together with the related theoretical and experimental studies, provide evidence of the composition and physical properties of dust particles, e.g., the presence of a large fraction of carbon in macromolecules, and of aggregates on a wide range of scales. The results have opened vivid discussions on the variety of dust-release processes and on the diversity of dust properties in comets, as well as on the formation of cometary dust, and on its presence in the near-Earth interplanetary medium. These discussions stress the significance of future explorations as a way to decipher the formation and evolution of our Solar System.

  4. Exergy analysis of photovoltaic solar collector

    International Nuclear Information System (INIS)

    Sopian, K.; Othman, M.Y.Hj.

    1998-01-01

    The exergy analysis (availability or second law analysis) is applied to the photovoltaic thermal solar collector. Photovoltaic thermal collector is a special type of solar collector where electricity and heat are produced simultaneously. The electricity produced from the photovoltaic thermal collector is all converted into useful work. The available quantity of the heat collected can readily be determined by taking into account both the quantity (heat quantity) and quality ( a function of temperature) of the thermal energy. Therefore, using the concept of exergy allows heat produced from the thermal collector and the electricity generated from the photovoltaic cells to be compared or to be evaluated on the basis of a common measure such as the effectiveness on solar energy collection or the total amount of available energy. In this paper, the effectiveness of solar energy collection is called combined photovoltaic thermal exergy efficiency. An experimental setup of a double pas photovoltaic thermal solar collector has been deigned, fabricated and tested. (author)

  5. PV-hybrid and thermoelectric collectors

    Energy Technology Data Exchange (ETDEWEB)

    Rockendorf, G.; Sillmann, R. [Institut fuer Solarenergieforschung GmbH, Emmerthal (Germany); Podlowski, L.; Litzenburger, B. [SolarWerk GmbH, Teltow (Germany)

    1999-07-01

    Two different principles of thermoelectric cogeneration solar collectors have been realized and investigated. Concerning the first principle, the thermoelectric collector (TEC) delivers electricity indirectly by first producing heat and subsequently generating electricity by means of a thermoelectric generator. Concerning the second principle, the photovoltaic-hybrid collector (PVHC) uses photovoltaic cells, which are cooled by a liquid heat-transfer medium. The characteristics of both collector types are described. Simulation modules have been developed and implemented in TRNSYS 14.1 (1994), in order to simulate their behaviour in typical domestic hot-water systems. The discussion of the results shows that the electric output of the PV-hybrid collector is significantly higher than that of the thermoelectric collector. (author)

  6. Standardized performance tests of collectors of solar thermal energy: Prototype moderately concentrating grooved collectors

    Science.gov (United States)

    1976-01-01

    Prototypes of moderately concentrating grooved collectors were tested with a solar simulator for varying inlet temperature, flux level, and incident angle. Collector performance is correlated in terms of inlet temperature and flux level.

  7. Allergies, asthma, and dust

    Science.gov (United States)

    Reactive airway disease - dust; Bronchial asthma - dust; Triggers - dust ... Things that make allergies or asthma worse are called triggers. Dust is a common trigger. When your asthma or allergies become worse due to dust, you are ...

  8. Depressed collectors for millimeter wave gyrotrons

    International Nuclear Information System (INIS)

    Singh, A.; Granatstein, V.L.

    1992-01-01

    The main issues relating to design of depressed collectors for millimeter wave gyrotrons are discussed. A flow diagram is presented and the interlinking steps are outlined. Design studies are given for two kinds of gyrotrons on which severe constraints on the maximum radii of the collectors had been imposed; namely, for a cavity type and a quasi-optical gyrotron. A collector efficiency of the order of 70 percent is shown to be feasible for either case using careful tailoring of magnetic field profiles. A code has been developed to assist in doing this. A general approach toward initial placement of collectors has been indicated

  9. Rising hopes for vacuum tube collectors

    Energy Technology Data Exchange (ETDEWEB)

    Godolphin, D.

    1982-06-01

    The performance, feasibility and use of vacuum tube solar collectors for domestic hot water (DHW) systems are discussed. An introduction to the design of vacuum tube collectors is presented and comparisons are made with flat plate collectors in terms of effectiveness in DHW applications and cost. The use of vacuum tube collectors is well established for high temperature use such as process heat and absorption cooling applications; there is considerable debate concerning their use in DHW and these arguments are presented. It is pointed out that the accepted standardized comparison test (ASHRAE 93-77) is apparently biased towards the flat plate collectors in direct comparisons of collector efficiencies. Recent developments among manufacturers with regard to vacuum tube collectors and their thinking (pro and con) are discussed in some detail. Breakage and other problems are pointed out although advocates look ahead to lower costs, higher efficiencies, and broader markets (particularly in DHW). It is concluded by some that flat plate collector technology has reached its peak and that vacuum tube collectors will be very prominent in the future. (MJJ)

  10. Stardust@home: An Interactive Internet-based Search for Interstellar Dust

    Science.gov (United States)

    Mendez, B. J.; Westphal, A. J.; Butterworth, A. L.; Craig, N.

    2006-12-01

    On January 15, 2006, NASA's Stardust mission returned to Earth after nearly seven years in interplanetary space. During its journey, Stardust encountered comet Wild 2, collecting dust particles from it in a special material called aerogel. At two other times in the mission, aerogel collectors were also opened to collect interstellar dust. The Stardust Interstellar Dust Collector is being scanned by an automated microscope at the Johnson Space Center. There are approximately 700,000 fields of view needed to cover the entire collector, but we expect only a few dozen total grains of interstellar dust were captured within it. Finding these particles is a daunting task. We have recruited many thousands of volunteers from the public to aid in the search for these precious pieces of space dust trapped in the collectors. We call the project Stardust@home. Through Stardust@home, volunteers from the public search fields of view from the Stardust aerogel collector using a web-based Virtual Microscope. Volunteers who discover interstellar dust particles have the privilege of naming them. The interest and response to this project has been extraordinary. Many people from all walks of life are very excited about space science and eager to volunteer their time to contribute to a real research project such as this. We will discuss the progress of the project and the education and outreach activities being carried out for it.

  11. Drying of Rosella (Hibiscus sabdariffa) Flower Petals using Solar Dryer with Double Glass Cover Collector

    OpenAIRE

    Tjukup Marnoto

    2014-01-01

    Chemical ingredients in rosella petals are very beneficial for health. Rosella petals needed to be drained for storage and packing purpose. The traditional drying takes 5 days and less healthy. Solar dryer technology can speed up the drying process and protect materials from dust contamination. Solar dryer with double glass covered collector has been designed and made for drying of agricultural products such as rosella flowers. Rosella petals as much as 2300 grams with initial moisture conten...

  12. Foldable Frame Supporting Electromagnetic Radiation Collectors

    DEFF Research Database (Denmark)

    2011-01-01

    The present invention relates to flexible frames supporting electromagnetic radiation collectors, such as antennas, antenna reflectors, deflectors or solar collectors, for celestial or terrestrial applications, which can be folded to be stored and/or transported. The method for stowing deforms...

  13. EFFECT OF BLENDING VARIOUS COLLECTORS AT BULK ...

    African Journals Online (AJOL)

    Nkana Concentrator under the ownership of the then Zambia Consolidated Copper Mines Ltd (ZCCM) had been using Sodium Ethyl Xanthate (SEX) mainly as a collector, but with the coming of new Mopani Copper Mines Plc (M.C.M), it was felt that there was a need to test alternative collectors in an attempt to improve the ...

  14. Flat-plate solar collector - installation package

    Science.gov (United States)

    1978-01-01

    Package includes installation, operation and maintenance manual for collector, analysis of safety hazards, special handling instructions, materials list, installation drawings, and warranty and certification statement. Manual includes instructions for roof preparation and for preparing collector for installation. Several pages are devoted to major and minor repairs.

  15. Performance of an absorbing concentrating solar collectors

    International Nuclear Information System (INIS)

    Imadojemu, H.

    1990-01-01

    This paper reports on a comparison of the efficiency of an absorbing fluid parabolic trough concentrating solar collector and a traditional concentrating collector that was made. In the absorbing fluid collector, black liquid flows through a glass tube absorber while the same black liquid flows through a selective black coated copper tube absorber while the same black fluid flows through a selective black coated copper tube absorber in the traditional collector. After a careful study of the properties of available black liquids, a mixture of water and black ink was chosen as the black absorbing medium or transfer fluid. In the black liquid glass collector there is a slightly improved efficiency based on beam radiation as a result of the direct absorption process and an increase in the effective transmittance absorptance. At worst the efficiency of this collector equals that of the traditional concentrating collector when the efficiency is based on total radiation. The collector's reflecting surfaces were made of aluminum sheet, parabolic line focus and with cylindrical receivers. The ease of manufacture and reduced cost per unit energy collected, in addition to the clean and pollution free mode of energy conversion, makes it very attractive

  16. Cheap effective thermal solar-energy collectors

    Energy Technology Data Exchange (ETDEWEB)

    Highgate, D.J.; Probert, S.D. [Cranfield University, Bedford (United Kingdom). Dept. of Applied Energy

    1996-04-01

    A light-weight flexible solar-collector, with a wavelength-selective absorption surface and an insolation-transparent thermal-insulation protecter for its aperture, was built and tested. Its cheapness and high performance, relative to a conventional flat-plate solar-collector, provide a prima-facie case for the more widespread adoption of its design. (author)

  17. Combined solar collector and energy storage system

    Science.gov (United States)

    Jensen, R. N. (Inventor)

    1980-01-01

    A combined solar energy collector, fluid chiller and energy storage system is disclosed. A movable interior insulated panel in a storage tank is positionable flush against the storage tank wall to insulate the tank for energy storage. The movable interior insulated panel is alternately positionable to form a solar collector or fluid chiller through which the fluid flows by natural circulation.

  18. OUT Success Stories: Transpired Solar Collectors

    International Nuclear Information System (INIS)

    Clyne, R.

    2000-01-01

    Transpired solar collectors are a reliable, low-cost technology for preheating building ventilation air. With simple payback periods ranging from 3 to 12 years and an estimated 30-year life span, transpired collector systems offer building owners substantial cost savings

  19. The Thermal Collector With Varied Glass Covers

    International Nuclear Information System (INIS)

    Luminosu, I.; Pop, N.

    2010-01-01

    The thermal collector with varied glass covers represents an innovation realized in order to build a collector able to reach the desired temperature by collecting the solar radiation from the smallest surface, with the highest efficiency. In the case of the thermal collector with variable cover glasses, the number of the glass plates covering the absorber increases together with the length of the circulation pipe for the working fluid. The thermal collector with varied glass covers compared to the conventional collector better meet user requirements because: for the same temperature increase, has the collecting area smaller; for the same collection area, realizes the highest temperature increase and has the highest efficiency. This works is addressed to researchers in the solar energy and to engineers responsible with air-conditioning systems design or industrial and agricultural products drying.

  20. COMPARATIVE FIELD EXPERIMENTAL INVESTIGATIONS OF DIFFERENT FLAT PLATE SOLAR COLLECTORS

    Directory of Open Access Journals (Sweden)

    Guangming Chen

    2015-12-01

    Full Text Available Full-scale traditional metal solar collectors and solar collector specimens fabricated from polymeric materials were investigated in the present study. A polymeric collector is 67.8% lighter than a traditional metal solar collector, and a metal solar collector with transparent plastic covering is 40.3% lighter than a traditional metal solar collector. Honeycomb multichannel plates made from polycarbonate were chosen to create a polymeric solar collector. A test rig for the natural circulation of the working fluid in a solar collector was built for a comparative experimental investigation of various solar collectors operating at ambient conditions. It was shown experimentally that the efficiency of a polymeric collector is 8–15% lower than the efficiency of a traditional collector.

  1. Single-stage depressed collectors for gyrotrons

    International Nuclear Information System (INIS)

    Piosczyk, B.; Iatrou, C.T.; Dammertz, G.; Thumm, M.; Univ. Karlsruhe

    1996-01-01

    Two 140 GHz gyrotrons with a single-step depressed collector have been operated. The different position of the isolating collector gap in the stray magnetic field causes the electron motion in the retarding region to be in one case adiabatic and in the other case nonadiabatic. The kind of motion within the retarding field influences strongly the behavior of the gyrotron with a depressed collector. In the case of nonadiabatic motion a significant amount of transverse momentum is given to the electrons reflected at the collector potential. This causes the reflected electrons to be trapped between the magnetic mirror and the collector. The electrons escape from the trap by diffusion across the magnetic field to the body of the tube thus contributing to the body current. Despite the high body current there is no observable influence of the collector voltage on the RF output power. In the case of adiabatic motion the reflected electrons do not gain a sufficient amount of transverse momentum to be trapped by the magnetic mirror. They pass the cavity toward the gun and they are trapped between the negative gun potential and the collector. The interaction with the RF field by electrons traveling through the cavity enhances the diffusion in the velocity space thus enabling the trapped electrons to overcome the potential barrier and escape toward the collector. Therefore the body current stays at low values since in this case the reflected electrons do not contribute to it. However, at higher collector voltages a reduction of RF power occurred and some noise in the electron beam was observed. The main motivation for the development of gyrotrons in the frequency range above 100 GHz with power levels in excess of several hundreds kW per tube, is the application in magnetic fusion devices for plasma heating and for electron current drive

  2. Engineering design of 500KW CW collector

    International Nuclear Information System (INIS)

    Kumar, Ramesh; Mishra, Deepak; Prasad, M.; Hannuarakar, P.R.

    2006-01-01

    An electron beam collector for 500kW beam power has been designed to test the electron gun. The gun is designed for 250kW, 350MHz CW Klystron with 50% efficiency. This will also help in preliminary studies related to final collector design for Klystron. This paper presents the design parameters, thermal analysis and mechanical features of the design. Electron trajectory on inside wall of the collector is determined with EGUN and computational flow dynamics simulation was done on ANSYS for cooling requirements. (author)

  3. Next Generation Solar Collectors for CSP

    Energy Technology Data Exchange (ETDEWEB)

    Molnar, Attila [3M Company, St. Paul, MN (United States); Charles, Ruth [3M Company, St. Paul, MN (United States)

    2014-07-31

    The intent of “Next Generation Solar Collectors for CSP” program was to develop key technology elements for collectors in Phase 1 (Budget Period 1), design these elements in Phase 2 (Budget Period 2) and to deploy and test the final collector in Phase 3 (Budget Period 3). 3M and DOE mutually agreed to terminate the program at the end of Budget Period 1, primarily due to timeline issues. However, significant advancements were achieved in developing a next generation reflective material and panel that has the potential to significantly improve the efficiency of CSP systems.

  4. Improved Large Aperture Collector Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    O' Rourke, Deven [Abengoa Solar LLC, Lakewood, CO (United States); Farr, Adrian [Abengoa Solar LLC, Lakewood, CO (United States)

    2015-12-01

    The parabolic trough is the most established CSP technology and carries a long history of design experimentation dating back to the 1970’s. This has led to relatively standardized collector architectures, a maturing global supply chain, and a fairly uniform cost reduction strategy. Abengoa has deployed more than 1,500MWe of CSP troughs across several countries and has built and tested full-scale prototypes of many R&D concepts. The latest trough R&D efforts involved efforts to internalize non-CSP industry experience including a preliminary DFMA principles review done with Boothroyd Dewhurst, a construction literature review by the Arizona State University School of Construction Management, and two more focused manufacturing engineering subcontracts done by Ricardo Inc. and the nonprofit Edison Welding Institute. The first two studies highlighted strong opportunities in lowering part count, standardizing components and fasteners, developing modular designs to support prefabrication and automation, and devising simple, error-proof manual assembly methods. These principles have delivered major new cost savings in otherwise “mature” products in analogous industries like automotive, truck trailer manufacture, metal building fabrication, and shipbuilding. For this reason, they were core in the design development of the SpaceTube® collector, and arguably key to its early successes. The latter two studies were applied specifically to the first-generation SpaceTube® design and were important in setting the direction of the present SolarMat project. These studies developed a methodology to analyze the costs of manufacture and assembly, and identify new tooling concepts for more efficient manufacture. Among the main opportunities identified in these studies were the automated mirror arm manufacturing concept and the need for a less infrastructure-intensive assembly line, both of which now form central pillars of the SolarMat project strategy. These new designs will be

  5. Movable air solar collector and its efficiency

    International Nuclear Information System (INIS)

    Lauva, A.; Aboltinš, A.; Palabinskis, J.; Karpova Sadigova, N.

    2008-01-01

    Implementing the guidelines of the Latvian National Programme for Energy in the field of alternative energy, intensive research shall be carried on regarding the use of solar energy, as it can be successfully used not only for the purposes of water heating and production of electrical energy, but also for air warming. The amount of heat necessary for the drying of rough forage and grain drying by active aeration in June, July and August can be obtained using solar radiation. The Latvian Guidelines for the Energy Development 2006-2016 state that the solar radiance in Latvia is of quite low intensity. The total amount of solar energy is 1109 kWh m -2 per year. The period of usage of the solar thermal energy is beginning from the last decade of April, when the intensity of radiation is 120 kWh m -2 , until the first decade of September. Within this period (approximately 1800 hours), it is possible to use the solar thermal energy by placing solar collectors. The usage of solar collectors for in drying of agricultural production is topical from the viewpoint of decreasing the consumption of energy used for the drying, as electrical energy and fossil energy resources become more expensive and tend to run out. In the processes that concern drying of agricultural production, efficiently enough solar radiation energy can be used. Due to this reason researching continues and expands in the field of usage of solar energy for the processes of drying and heating. The efficiency factor of the existing solar collectors is not high, but they are of simple design and cheep for production and exploitation. By improving the design of the solar collectors and choosing modern materials that absorb the solar radiation energy, it is possible the decrease the efficiency factor of solar collectors and decrease the production costs. In the scientific laboratory of grain drying and storage of Latvia University of Agriculture, a pilot device movable folding solar collector pilot device

  6. Education and Public Outreach for Stardust@home: An Interactive Internet-based Search for Interstellar Dust

    Science.gov (United States)

    Mendez, Bryan J.; Westphal, A. J.; Butterworth, A. L.; Craig, N.

    2006-12-01

    On January 15, 2006, NASA’s Stardust mission returned to Earth after nearly seven years in interplanetary space. During its journey, Stardust encountered comet Wild 2, collecting dust particles from it in a special material called aerogel. At two other times in the mission, aerogel collectors were also opened to collect interstellar dust. The Stardust Interstellar Dust Collector is being scanned by an automated microscope at the Johnson Space Center. There are approximately 700,000 fields of view needed to cover the entire collector, but we expect only a few dozen total grains of interstellar dust were captured within it. Finding these particles is a daunting task. We have recruited many thousands of volunteers from the public to aid in the search for these precious pieces of space dust trapped in the collectors. We call the project Stardust@home. Through Stardust@home, volunteers from the public search fields of view from the Stardust aerogel collector using a web-based Virtual Microscope. Volunteers who discover interstellar dust particles have the privilege of naming them. The interest and response to this project has been extraordinary. Many people from all walks of life are very excited about space science and eager to volunteer their time to contribute to a real research project such as this. We will discuss the progress of the project and the education and outreach activities being carried out for it.

  7. Optimal nonimaging integrated evacuated solar collector

    Science.gov (United States)

    Garrison, John D.; Duff, W. S.; O'Gallagher, Joseph J.; Winston, Roland

    1993-11-01

    A non imaging integrated evacuated solar collector for solar thermal energy collection is discussed which has the lower portion of the tubular glass vacuum enveloped shaped and inside surface mirrored to optimally concentrate sunlight onto an absorber tube in the vacuum. This design uses vacuum to eliminate heat loss from the absorber surface by conduction and convection of air, soda lime glass for the vacuum envelope material to lower cost, optimal non imaging concentration integrated with the glass vacuum envelope to lower cost and improve solar energy collection, and a selective absorber for the absorbing surface which has high absorptance and low emittance to lower heat loss by radiation and improve energy collection efficiency. This leads to a very low heat loss collector with high optical collection efficiency, which can operate at temperatures up to the order of 250 degree(s)C with good efficiency while being lower in cost than current evacuated solar collectors. Cost estimates are presented which indicate a cost for this solar collector system which can be competitive with the cost of fossil fuel heat energy sources when the collector system is produced in sufficient volume. Non imaging concentration, which reduces cost while improving performance, and which allows efficient solar energy collection without tracking the sun, is a key element in this solar collector design.

  8. Investigating the collector efficiency of silver nanofluids based direct absorption solar collectors

    International Nuclear Information System (INIS)

    Chen, Meijie; He, Yurong; Zhu, Jiaqi; Wen, Dongsheng

    2016-01-01

    Highlights: • An analysis coupled with Radiation transfer, Maxwell and Energy equation is developed. • Plasmonic Au and Ag nanofluids show better photo-thermal conversion properties. • Collector height and particle concentration exist optimum solutions for efficiency. - Abstract: A one-dimensional transient heat transfer analysis was carried out to analyze the effects of the Nanoparticle (NP) volume fraction, collector height, irradiation time, solar flux, and NP material on the collector efficiency. The numerical results were compared with the experimental results obtained by silver nanofluids to validate the model, and good agreement was obtained. The numerical results show that the collector efficiency increases as the collector height and NP volume fraction increase and then reaches a maximum value. An optimum collector height (∼10 mm) and particle concentration (∼0.03%) achieving a collector efficiency of 90% of the maximum efficiency can be obtained under the conditions used in the simulation. However, the collector efficiency decreases as the irradiation time increases owing to the increased heat loss. A high solar flux is desirable to maintain a high efficiency over a wide temperature range, which is beneficial for subsequent energy utilization. The modeling results also show silver and gold nanofluids obtain higher photothermal conversion efficiencies than the titanium dioxide nanofluid because their absorption spectra are similar to the solar radiation spectrum.

  9. Two new designs of parabolic solar collectors

    Directory of Open Access Journals (Sweden)

    Karimi Sadaghiyani Omid

    2014-01-01

    Full Text Available In this work, two new compound parabolic trough and dish solar collectors are presented with their working principles. First, the curves of mirrors are defined and the mathematical formulation as one analytical method is used to trace the sun rays and recognize the focus point. As a result of the ray tracing, the distribution of heat flux around the inner wall can be reached. Next, the heat fluxes are calculated versus several absorption coefficients. These heat flux distributions around absorber tube are functions of angle in polar coordinate system. Considering, the achieved heat flux distribution are used as a thermal boundary condition. After that, Finite Volume Methods (FVM are applied for simulation of absorber tube. The validation of solving method is done by comparing with Dudley's results at Sandia National Research Laboratory. Also, in order to have a good comparison between LS-2 and two new designed collectors, some of their parameters are considered equal with together. These parameters are consist of: the aperture area, the measures of tube geometry, the thermal properties of absorber tube, the working fluid, the solar radiation intensity and the mass flow rate of LS-2 collector are applied for simulation of the new presented collectors. After the validation of the used numerical models, this method is applied to simulation of the new designed models. Finally, the outlet results of new designed collector are compared with LS-2 classic collector. Obviously, the obtained results from the comparison show the improving of the new designed parabolic collectors efficiency. In the best case-study, the improving of efficiency are about 10% and 20% for linear and convoluted models respectively.

  10. Bioinspired plate-based fog collectors.

    Science.gov (United States)

    Heng, Xin; Luo, Cheng

    2014-09-24

    In a recent work, we explored the feeding mechanism of a shorebird to transport liquid drops by repeatedly opening and closing its beak. In this work, we apply the corresponding results to develop a new artificial fog collector. The collector includes two nonparallel plates. It has three advantages in comparison with existing artificial collectors: (i) easy fabrication, (ii) simple design to scale up, and (iii) active transport of condensed water drops. Two collectors have been built. A small one with dimensions of 4.2 × 2.1 × 0.05 cm(3) (length × width × thickness) was first built and tested to examine (i) the time evolution of condensed drop sizes and (ii) the collection processes and efficiencies on the glass, SiO2, and SU-8 plates. Under similar experimental conditions, the amount of water collected per unit area on the small collector is about 9.0, 4.7, and 3.7 times, respectively, as much as the ones reported for beetles, grasses, and metal wires, and the total amount of water collected is around 33, 18, and 15 times. On the basis of the understanding gained from the tests on the small collector, a large collector with dimensions of 26 × 10 × 0.2 cm(3) was further built and tested, which was capable of collecting 15.8 mL of water during a period of 36 min. The amount of water collected, when it is scaled from 36 to 120 min, is about 878, 479, or 405 times more than what was collected by individual beetles, grasses, or metal wires.

  11. Prototype Development and Evaluation of Self-Cleaning Concentrated Solar Power Collectors

    Energy Technology Data Exchange (ETDEWEB)

    Mazumder, Malay K. [Boston Univ., MA (United States); Horenstein, Mark N. [Boston Univ., MA (United States); Joglekar, Nitin R. [Boston Univ., MA (United States)

    2015-03-31

    The feasibility of integrating and retrofitting transparent electrodynamic screens (EDS) on the front surfaces of solar collectors was established as a means to provide active self-cleaning properties for parabolic trough and heliostat reflectors, solar panels, and Fresnel lenses. Prototype EDS-integrated solar collectors, including second-surface glass mirrors, metallized Acrylic-film mirrors, and dielectric mirrors, were produced and tested in environmental test chambers for removing the dust layer deposited on the front surface of the mirrors. The evaluation of the prototype EDS-integrated mirrors was conducted using dust and environmental conditions that simulate the field conditions of the Mojave Desert. Test results showed that the specular reflectivity of the mirrors could be maintained at over 90% over a wide range of dust loadings ranging from 0 to 10 g/m2, with particle diameter varying from 1 to 50 μm. The measurement of specular reflectivity (SR) was performed using a D&S Reflectometer at wavelength 660 nm. A non-contact reflectometer was designed and constructed for rapid measurement of specular reflectivity at the same wavelength. The use of this new noncontact instrument allowed us to measure SR before and after EDS activation. Several EDS prototypes were constructed and evaluated with different electrode configurations, electrode materials, and encapsulating dielectric materials.

  12. Heat Pumps With Direct Expansion Solar Collectors

    Science.gov (United States)

    Ito, Sadasuke

    In this paper, the studies of heat pump systems using solar collectors as the evaporators, which have been done so far by reserchers, are reviwed. Usually, a solar collector without any cover is preferable to one with ac over because of the necessity of absorbing heat from the ambient air when the intensity of the solar energy on the collector is not enough. The performance of the collector depends on its area and the intensity of the convective heat transfer on the surface. Fins are fixed on the backside of the collector-surface or on the tube in which the refrigerant flows in order to increase the convective heat transfer. For the purpose of using a heat pump efficiently throughout year, a compressor with variable capacity is applied. The solar assisted heat pump can be used for air conditioning at night during the summer. Only a few groups of people have studied cooling by using solar assisted heat pump systems. In Japan, a kind of system for hot water supply has been produced commercially in a company and a kind of system for air conditioning has been installed in buildings commercially by another company.

  13. Efficiency of the Fermilab Electron Cooler's Collector

    CERN Document Server

    Prost, L R

    2005-01-01

    The newly installed high-energy Recycler Electron Cooling system (REC) at Fermilab will work at an electron energy of 4.34 MeV and a DC beam current of 0.5 A in an energy recovery scheme. For reliable operation of the system, the relative beam current loss must be maintained to levels < 3.e-5. Experiments have shown that the loss is determined by the performance of the electron beam collector, which must retain secondary electrons generated by the primary beam hitting its walls. As a part of the Electron cooling project, the efficiency of the collector for the REC was optimized, both with dedicated test bench experiments and on two versions of the cooler prototype. We find that to achieve the required relative current loss, an axially-symmetric collector must be immersed in a transverse magnetic field with certain strength and gradient prescriptions. Collector efficiencies in various magnetic field configurations, including without a transverse field on the collector, are presented and discussed

  14. Tube collector with integrated tracking parabolic concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Grass, C.; Benz, N.; Hacker, Z.; Timinger, A. [ZAE Bayern, Bavarian Centre for Applied Energy Research, Muenchen (Germany)

    2000-07-01

    Low concentrating CPC collectors usually do not track the sun and are mounted in east-west direction with a latitude dependent slope angle. They are most suitable for maximum working temperatures up to 200 250 deg. C. We present a novel evacuated tube-collector with a trough-like concentrating mirror. Single-axis tracking of the mirror is realized with a magnetic mechanism. The mirror is mounted inside the evacuated tube and hence protected from environmental influences. One axis tracking in combination with a small acceptance angle allows for higher concentration as compared to non-tracking concentrating collectors. Ray-tracing analysis shows a half acceptance angle of about 5 deg. at a geometrical concentration ratio of 3.2. The losses of evacuated tube collectors are dominated by the radiation losses of the absorber. Hence, reducing the absorber size can lead to higher efficiencies at high operating temperature levels. With the presented collector we aim for operating temperatures up to 400 deg. C. At temperatures of 300 deg. C we expect efficiencies of 65 %. This allows for application in industrial process heat generation, high efficient solar cooling and power generation. A first prototype was tested at the ZAE Bayern. The optical efficiency was measured to be 75 %. (au)

  15. Efficiencies of flat plate solar collectors at different flow rates

    DEFF Research Database (Denmark)

    Chen, Ziqian; Furbo, Simon; Perers, Bengt

    2012-01-01

    Two flat plate solar collectors for solar heating plants from Arcon Solvarme A/S are tested in a laboratory test facility for solar collectors at Technical University of Denmark (DTU). The collectors are designed in the same way. However, one collector is equipped with an ETFE foil between...... the absorber and the cover glass and the other is without ETFE foil. The efficiencies for the collectors are tested at different flow rates. On the basis of the measured efficiencies, the efficiencies for the collectors as functions of flow rate are obtained. The calculated efficiencies are in good agreement...

  16. A solar collector for air-conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Kose, E. [Microtherm Energietechnik GmbH, 25 - Lods (France)

    1999-03-01

    A high performance Compound Parabolic Concentrator (CPC) collector is presented. It comprises dewar type tubular vacuum tubes with an absorber coating of very low emittance, a moderately concentrating reflector and a simple thermosyphon heat removal system. The reflectors car be designed with respect to the specific needs; reflector material, concentration, truncation and symmetry car be chosen freely. The collector allows the construction of cooling systems with higher COP's without using tracking systems. Land use and costs are greatly reduced. For a certain application (optimum yearly gain in Munich with a constant collector temperature of 180 deg C) the reflector was optimized, it is a fairly asymmetrical design. A symmetrical design with a similar performance has been tested, the results are shown. (author)

  17. Optimum solar collector fluid flow rates

    DEFF Research Database (Denmark)

    Furbo, Simon; Shah, Louise Jivan

    1996-01-01

    Experiments showed that by means of a standard electronically controlled pump, type UPE 2000 from Grundfos it is possible to control the flow rate in a solar collector loop in such a way that the flow rate is strongly influenced by the temperature of the solar collector fluid passing the pump....... The flow rate is increasing for increasing temperature.The flow rate at the high temperature level is typically 70 % greater than the flow rate at the low temperature level.Further, the energy consumption for the electronically controlled pump in a solar heating system will be somewhat smaller than...... the energy consumption of a normal ciculation pump in the solar heating system.Calculations showed that the highest thermal performances for small SDHW systems based on mantle tanks with constant volume flow rates in the solar collector loops are achieved if the flow rate is situated in the interval from 0...

  18. Recent progress in terrestrial photovoltaic collector technology

    Science.gov (United States)

    Ferber, R. R.

    1982-01-01

    The U.S. Photovoltaic Research and Development Program has the objective to develop the technology necessary to foster widespread grid-competitive electric power generation by the late 1980s. The flat-plate and the concentrator collector activities form the nucleus of the program. The project is concerned with the refining of silicon, silicon sheet production, solar cell processing and fabrication, encapsulation materials development, and collector design and production. The Large-Area Silicon Sheet Task has the objective to develop and demonstrate the feasibility of several methods for producing large area silicon sheet material suitable for fabricating low-cost, high-efficiency solar cells. It is expected that a variety of economic flat-plate and concentrator collectors will become commercially available for grid-connected applications.

  19. A stationary evacuated collector with integrated concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Snail, K.A.; O' Gallagher, J.J.; Winston, R.

    1984-01-01

    A comprehensive set of experimental tests and detailed optical and thermal models are presented for a newly developed solar thermal collector. The new collector has an optical efficiency of 65 per cent and achieves thermal efficiencies of better than 50 per cent at fluid temperatures of 200/sup 0/C without tracking the sun. The simultaneous features of high temperature operation and a fully stationary mount are made possible by combining vacuum insulation, spectrally selective coatings, and nonimaging concentration in a novel way. These 3 design elements are ''integrated'' together in a self containe unit by shaping the outer glass envelope of a conventional evacuated tube into the profile of a nonimaging CPC-type concentrator. This permits the use of a first surface mirror and eliminates the need for second cover glazing. The new collector has been given the name ''Integrated Stationary Evacuated Concentrator'', or ISEC collector. Not only is the peak thermal efficiency of the ISEC comparable to that of commercial tracking parabolic troughs, but projections of the average yearly energy delivery also show competitive performance with a net gain for temperatures below 200/sup 0/C. In addition, the ISEC is less subject to exposure induced degradation and could be mass produced with assembly methods similar to those used with fluorescent lamps. Since no tracking or tilt adjustments are ever required and because its sensitive optical surfaces are protected from the environment, the ISEC collector provides a simple, easily maintained solar thermal collector for the range 100-300/sup 0/C which is suitable for most climates and atmospheric conditions. Potential applications include space heating, air conditioning, and industrial process heat.

  20. Qualification test and analysis report: solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    Test results show that the Owens-Illinois Sunpak/sup TM/ Model SEC 601 air-cooled collector meets the national standards and codes as defined in the Subsystem Performance Specification and Verification Plan of NASA/MSFC Contract NAS8-32259, dated October 28, 1976. The architectural and engineering firm of Smith, Hinchman and Grylls, Detroit, Michigan, acted in the capacity of the independent certification agency. The program calls for the development, fabrication, qualification and delivery of an air-liquid solar collector for solar heating, combined heating and cooling, and/or hot water systems.

  1. Short-Term Solar Collector Power Forecasting

    DEFF Research Database (Denmark)

    Bacher, Peder; Madsen, Henrik; Perers, Bengt

    2011-01-01

    This paper describes a new approach to online forecasting of power output from solar thermal collectors. The method is suited for online forecasting in many applications and in this paper it is applied to predict hourly values of power from a standard single glazed large area flat plate collector...... enabling tracking of changes in the system and in the surrounding conditions, such as decreasing performance due to wear and dirt, and seasonal changes such as leaves on trees. This furthermore facilitates remote monitoring and check of the system....

  2. Low cost anti-soiling coatings for CSP collector mirrors and heliostats

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Barton Barton [ORNL; Polyzos, Georgios [ORNL; Schaeffer, Daniel A [ORNL; Lee, Dominic F [ORNL; Datskos, Panos G [ORNL

    2014-01-01

    Most concentrating solar power (CSP) facilities in the USA are located in the desert southwest of the country where land and sunshine are abundant. But one of the significant maintenance problems and cost associated with operating CSP facilities in this region is the accumulation of dust, sand and other pollutants on the collector mirrors and heliostats. In this paper we describe the development of low cost, easy to apply anti-soiling coatings based on superhydrophobic (SH) functionalized nano silica materials and polymer binders that posses the key requirements necessary to inhibit particulate deposition on and sticking to CSP mirror surfaces, and thereby significantly reducing mirror cleaning costs and facility downtime.

  3. Comparison of three different collectors for process heat applications

    Science.gov (United States)

    Brunold, Stefan; Frey, R.; Frei, Ulrich

    1994-09-01

    In general vacuum tube collectors are used in solar process heat systems. Another possibility is to use transparent insulated flat plate collectors. A critical point however, is that most of the common transparent insulating materials can not withstand high temperatures because they consist of plastics. Thus, temperature resistive collector covers combining a high tranmisivity with a low U-value are required. One possibility is to use capillaries made of glass instead of plastics. Measurement results of collector efficiency and incident angle modifier will be presented as well as calculated energy gains for three different collectors: a vacuum tube collector (Giordano Ind., France), a CPC vacuum tube collector (microtherm Energietechnik Germany; a new flat plate collector using glass capillary as transparent insulation (SET, Germany).

  4. Behavior of a solar collector loop during stagnation

    DEFF Research Database (Denmark)

    Chen, Ziqian; Dragsted, Janne; Furbo, Simon

    2015-01-01

    A mathematical model simulating the emptying behavior of a pressurized solar collector loop with solar collectors with a good emptying behavior is developed and validated with measured data. The calculated results are in good agreement with the measured results. The developed simulation model...... is therefore suitable to determine the behavior of a solar collector loop during stagnation. A volume ratio R, which is the ratio of the volume of the vapour in the upper pipes of the solar collector loop during stagnation and the fluid content of solar collectors, is introduced to determine the mass...... of the collector fluid pushed into the expansion vessel during stagnation, Min. A correlation function for the mass Min and the volume ratio R for solar collector loops is obtained. The function can be used to determine a suitable size of expansion vessels for solar collector loops....

  5. Two-axis movable concentrating solar energy collector

    Science.gov (United States)

    Perkins, G. S.

    1977-01-01

    Proposed solar-tracker collector assembly with boiler in fixed position, allows use of hard line connections, capable of withstanding optimum high temperature fluid flow. System thereby eliminates need for flexible or slip connection previously used with solar collector systems.

  6. SPARCLE: Electrostatic Dust Control Tool Proof of Concept

    Science.gov (United States)

    Clark, P. E.; Curtis, S. A.; Minetto, F.; Marshall, J.; Nuth, J.; Calle, C.

    2010-01-01

    Successful exploration of most planetary surfaces, with their impact-generated dusty regoliths, will depend on the capabilities to keep surfaces free of the performance-compromising dust. Once in contact with surfaces, whether set in motion by natural or mechanical means, regolith fines, or dust, behave like abrasive Velcro, coating surfaces, clogging mechanisms, making movement progressively more difticult, and being almost impossible to remove by mechanical mcans (brushing). The successful dust removal strategy will deal with dust dynamics resulting from interaction between Van der Waals and Coulombic forces. Here, proof of concept for an electrostatically-based concept for dust control tool is described and demonstrated. A low power focused electron beam is used in the presence of a small electrical field to increase the negative charge to mass ratio of a dusty surface until dust repulsion and attraction to a lower potential surface, acting as a dust collector, occurred. Our goal is a compact device of less than 5 kg mass and using less than 5 watts of power to be operational in less than 5 years with heritage from ionic sweepers for active spacecraft potential control (e.g ., on POLAR). Rovers could be fitted with devices that could hamess the removal of dust for sampling as part of the extended exploration process on Mercury, Mars, asteroids or outer solar system satellites, as well as the Moon.

  7. A tool for standardized collector performance calculations including PVT

    DEFF Research Database (Denmark)

    Perers, Bengt; Kovacs, Peter; Olsson, Marcus

    2012-01-01

    A tool for standardized calculation of solar collector performance has been developed in cooperation between SP Technical Research Institute of Sweden, DTU Denmark and SERC Dalarna University. The tool is designed to calculate the annual performance of solar collectors at representative locations...... can be tested and modeled as a thermal collector, when the PV electric part is active with an MPP tracker in operation. The thermal collector parameters from this operation mode are used for the PVT calculations....

  8. PERFORMANCE EVALUATION OF SOLAR COLLECTORS USING A SOLAR SIMULATOR

    OpenAIRE

    M. Norhafana; Ahmad Faris Ismail; Z. A. A. Majid

    2015-01-01

    Solar water heating systems is one of the applications of solar energy. One of the components of a solar water heating system is a solar collector that consists of an absorber. The performance of the solar water heating system depends on the absorber in the solar collector. In countries with unsuitable weather conditions, the indoor testing of solar collectors with the use of a solar simulator is preferred. Thus, this study is conducted to use a multilayered absorber in the solar collector of...

  9. Local Reasoning about a Copying Garbage Collector

    DEFF Research Database (Denmark)

    Torp-Smith, Noah; Birkedal, Lars; Reynolds, John C.

    2008-01-01

    We present a programming language, model, and logic appropriate for implementing and reasoning about a memory management system. We state semantically what is meant by correctness of a copying garbage collector, and employ a variant of the novel separation logics to formally specify partial corre...

  10. 31 CFR 203.17 - Collector depositaries.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Collector depositaries. 203.17 Section 203.17 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE PAYMENT OF FEDERAL TAXES AND THE TREASURY...

  11. Copyright, Property and the Film Collector

    Science.gov (United States)

    Nevins, Francis M., Jr.

    1975-01-01

    Legal issues surrounding the collecting of movies are analyzed with the conclusion that neither law nor public policy supports a cause for action against the ultimate consumer of film prints and that it is not in a studio's economic interest to bring such actions against collectors. (JT)

  12. Dust Measurements in Tokamaks

    International Nuclear Information System (INIS)

    Rudakov, D; Yu, J; Boedo, J; Hollmann, E; Krasheninnikov, S; Moyer, R; Muller, S; Yu, A; Rosenberg, M; Smirnov, R; West, W; Boivin, R; Bray, B; Brooks, N; Hyatt, A; Wong, C; Fenstermacher, M; Groth, M; Lasnier, C; McLean, A; Stangeby, P; Ratynskaia, S; Roquemore, A; Skinner, C; Solomon, W M

    2008-01-01

    Dust production and accumulation impose safety and operational concerns for ITER. Diagnostics to monitor dust levels in the plasma as well as in-vessel dust inventory are currently being tested in a few tokamaks. Dust accumulation in ITER is likely to occur in hidden areas, e.g. between tiles and under divertor baffles. A novel electrostatic dust detector for monitoring dust in these regions has been developed and tested at PPPL. In DIII-D tokamak dust diagnostics include Mie scattering from Nd:YAG lasers, visible imaging, and spectroscopy. Laser scattering resolves size of particles between 0.16-1.6 (micro)m in diameter; the total dust content in the edge plasmas and trends in the dust production rates within this size range have been established. Individual dust particles are observed by visible imaging using fast-framing cameras, detecting dust particles of a few microns in diameter and larger. Dust velocities and trajectories can be determined in 2D with a single camera or 3D using multiple cameras, but determination of particle size is problematic. In order to calibrate diagnostics and benchmark dust dynamics modeling, pre-characterized carbon dust has been injected into the lower divertor of DIII-D. Injected dust is seen by cameras, and spectroscopic diagnostics observe an increase of carbon atomic, C2 dimer, and thermal continuum emissions from the injected dust. The latter observation can be used in the design of novel dust survey diagnostics

  13. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    International Nuclear Information System (INIS)

    Ye Zhuang; Stanley J. Miller; Grant E. Dunham; Michelle R. Olderbak

    2002-01-01

    Since 1995, DOE has supported development of a new concept in particulate control, called the advanced hybrid particulate collector (AHPC). The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emission with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a utility power plant to prove scaleup and demonstrate longer-term mercury control. This project, if successful, will demonstrate at the pilot-scale level a technology that would provide a cost-effective technique to accomplish control of mercury emissions and, at the same time, greatly enhance fine particulate collection efficiency. The technology can be used to retrofit systems currently employing inefficient ESP technology as well as for new construction, thereby providing a solution to a large segment of the U.S. utility industry as well as other industries requiring mercury control

  14. Colored solar collectors - Annual report 2006

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, A.; Chambrier, E. De; Roecker, Ch.; Scartezzini, J.-L.

    2007-12-15

    The architectural integration of thermal solar collectors into buildings is often limited by their black color, and the visibility of tubes and corrugations of the absorber sheets. A certain freedom in color choice would be desirable, but the colored appearance should not cause an excessive degradation of the collector efficiency. Multilayered thin film interference filters on the collector glazing can produce a colored reflection, hiding the corrugated metal sheet, while transmitting the non-reflected radiation entirely to the absorber. These interference filters are designed and optimized by numerical simulation, and are manufactured by sol-gel dip-coating or magnetron sputtering. The novel colored glazed solar collectors will be ideally suited for architectural integration into buildings, e.g. as solar active glass facades. Due to the tunability of the refractive index, nanostructured materials such as SiO{sub 2}:TiO{sub 2} composites and porous SiO{sub 2} are very useful for application in multilayer interference stacks. Novel quaternary Mg-F-Si-O films exhibit a surprisingly low refractive index and are therefore promising candidates for highly transparent coatings on solar collector glazing. The nanostructure of these thin films is studied by transmission electron microscopy, while the optical constants are measured precisely by ellipsometry. For a convincing demonstration, sufficiently large samples of high quality are imperatively needed. The fabrication of nanocomposite SiO{sub 2}:TiO{sub 2} films has been demonstrated by sol-gel dip-coating of A4-sized glass panes. The produced coatings exhibit a colored reflection in combination with a high solar transmittance, a homogenous appearance, and are free of visible defects. Film hardening by UV exposure will result in speeding up the sol-gel process and saving energy, thereby reducing costs significantly. The infrastructure for UV-curing has been established. A UV C radiation source can now be attached to the

  15. Standardized performance tests of collectors of solar thermal energy - A flat-plate copper collector with parallel mylar striping

    Science.gov (United States)

    Johnson, S. M.

    1976-01-01

    Basic test results are reported for a flat plate solar collector whose performance was determined in a solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and one coolant flow rate. Collector efficiency is correlated in terms of inlet temperature and flux level.

  16. Standardized performance tests of collectors of solar thermal energy: A selectively coated, steel collector with one transparent cover

    Science.gov (United States)

    1976-01-01

    Basic test results are presented of a flat-plate solar collector whose performance was determined in solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and coolant flow rates. Collector efficiency was correlated in terms of inlet temperature and flux level.

  17. Standardized performance tests of collectors of solar thermal energy: An evacuated flatplate copper collector with a serpentine flow distribution

    Science.gov (United States)

    Johnson, S. M.

    1976-01-01

    Basic test results are given for a flat plate solar collector whose performance was determined in the NASA-Lewis solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and one coolant flow rate. Collector efficiency is correlated in terms of inlet temperature and flux level.

  18. Arrangement, manufacturing process and use of solar heat collectors

    Energy Technology Data Exchange (ETDEWEB)

    Scheel, H W

    1978-03-30

    Solar collectors generally have a timber or metal frame where the transparent front cover, usually of glass, is replaceable. In order to prevent great deformation, such a frame must be relatively stable and of heavy construction, which may lead to difficulties in mounting the collector on the roofs or front walls of houses. The present invention proposes a light but nevertheless rigid collector frame, which consists of plastic material and is constructed so that the installation and replacement of collectors can be realized. Further, collectors are proposed which guarantee a minimum of reflection and are so designed that an optimum architectural effect is produced.

  19. Solar collector design with respect to moisture problems

    DEFF Research Database (Denmark)

    Holck, Ole; Svendsen, Svend; Brunold, Stefan

    2003-01-01

    more ventilation openings should be made and what influence the insulation material has. Guidelines for collector designers are proposed. The design guidelines provide some suggestions to be considered during the design of solar collectors.The work was carried out within the framework of the working...... group Materials in Solar Thermal Collectors of the International Energy Agency-Solar Heating and Cooling Programme....... the design of the collector, the location and size of ventilation holes, properties of the insulation materials and dimension of the solar collector box are parameters that have to be taken into account for the optimisation in order to achieve the most favourable microclimate to prevent corrosion...

  20. Integrated Design of Undepressed Collector for Low Power Gyrotron

    Science.gov (United States)

    Kumar, Anil; Goswami, Uttam K.; Poonia, Sunita; Singh, Udaybir; Kumar, Nitin; Alaria, M. K.; Bera, A.; Khatun, Hasina; Sinha, A. K.

    2011-06-01

    A 42 GHz, 200 kW continuous wave (CW) gyrotron, operating at TE03 mode is under development for the electron cyclotron resonance plasma heating of the Indian TOKAMAK system. The gyrotron is made up of an undepressed collector. The undepressed collector is simple to design and cost effective. In this paper, a detailed design study of the undepressed collector for the 42 GHz gyrotron is presented. The EGUN code is used to analyze the spent electron beam trajectory for the maximum spread to reduce the power loading on the collector surface. To achieve wall loading ≤1 kW/cm2, a collector with a length of 800 mm and a radius of 42.5 mm is designed. The design also includes the three magnet systems around the collector for maximum and uniform beam spread. The thermal and the structural analyses are done using the ANSYS code to optimize the collector structure and dimensions with tolerance.

  1. Solar Heating Systems with Evacuated Tubular Solar Collector

    DEFF Research Database (Denmark)

    Qin, Lin; Furbo, Simon

    1998-01-01

    Recently different designed evacuated tubular solar collectors were introduced on the market by different Chinese companies. In the present study, investigations on the performance of four different Chinese evacuated tubular collectors and of solar heating systems using these collectors were...... carried out, employing both laboratory test and theoretical calculations. The collectors were tested in a small solar domestic hot water (SDHW) system in a laboratory test facility under realistic conditions. The yearly thermal performance of solar heating systems with these evacuated tubular collectors......, as well as with normal flat-plate collectors was calculated under Danish weather conditions. It is found that, for small SDHW systems with a combi tank design, an increase of 25% -55% net utilized solar energy can be achieved by using these evacuated tubular collectors instead of normal flat...

  2. Measuring Dust Emission from the Mojave Desert (USA) by Daily Remote-Camera Observations and Wind-Erosion Measurements: Bearing on "Unseen" Sources and Global Dust Abundance

    Science.gov (United States)

    Reynolds, R. L.; Urban, F.; Goldstein, H. L.; Fulton, R.

    2017-12-01

    A large gap in understanding the effects of atmospheric dust at all spatial scales is uncertainty about how much and whence dust is emitted annually. Digital recording of dust emission at high spatial and temporal resolution would, together with periodic flux measurements, support improved estimates of local-scale dust flux where infrastructure could support remote internet enabled cameras. Such recording would also elucidate wind-erosion dynamics when combined with meteorological data. Remote camera recording of dust-emitting settings on and around Soda Lake (Mojave Desert) was conducted every 15 minutes during daylight between 10 Nov. 2010 and 31 Dec. 2016 and images uploaded to a web server. Examination of 135,000 images revealed frequent dust events, termed "dust days" when plumes obscured mountains beyond source areas. Such days averaged 68 (sd=10) per year (2011 through 2016). We examined satellite retrievals (MODIS, GOES) for dust events during six cloudless days of highest and longest duration dust emission but none were observed. From Apr. 2000 through May 2013, aeolian sediments collected at three sites were sampled and weighed. Estimates of the emitted mass of silt- and clay-size fractions were made on the basis of measured horizontal mass flux, particle sizes of sediment in collectors, and roughly determined areas of dust generation. Over this period, nearly 4 Tg yr-1 of dust (as particulate matter flood in the basin in late Dec. 2010 that deposited flood sediment across the lake basin. Increased emission was likely related to the availability of fresh, unanchored flood sediment. Within the Mojave and Great Basin deserts of North America, many settings akin to those at Soda Lake similarly emit dust that is rarely detected in satellite retrievals. These findings strongly imply that local and regional dust emissions from western North America are far underestimated and that, by extension to relatively small dust-source areas across all drylands, global

  3. Preheating of tap water with solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Granum, H; Raaen, H

    1992-05-05

    In 1991 SINTEF Architecture and Building Technology won the second prize in 'The Nordic Competition for Low Energy Buildings' with a project proposal named 'LOWe'. The paper gives a description of the energy-saving features of this project, particularly the use of a solar collector for preheating of tap water. Compared with the economic profitability of other saving efforts in the project, such as good thermal insulation and efficient heat recovering system, the system for solar preheating of tap water does not seem very attractive for the time being. Loose estimates indicate a cost of close of NOK 1.00 per kWh for the produced energy in the solar collector, while the present price for electricity in Norway is about NOK 0.50 per kWh. Compared with a heat pump solution however the energy cost is not unreasonable.

  4. Assessment of musculoskeletal load in refuse collectors

    Directory of Open Access Journals (Sweden)

    Zbigniew W. Jóźwiak

    2013-08-01

    Full Text Available Background: The aim of this work was to assess the load on the musculoskeletal system and its effects in the collectors of solid refuse. The rationale behind this study was to formulate proposals how to reduce excessive musculoskeletal load in this group of workers. Material and Methods: The study group comprised 15 refuse collectors aged 25 to 50 years. Data about the workplace characteristics and subjective complaints of workers were collected by the free interview and questionnaire. During the survey the photorecording of the workpostures, the distance and velocity by GPS recorders, measurements of forces necessary to move containers, energy expenditure (lung ventilation method, workload estimation using the Firstbeat system and REBA method and stadiometry were done. Results: The distance walked daily by the collectors operating in terms of 2 to 3 in urban areas was about 15 km, and in rural areas about 18 km. The most frequent musculoskeletal complaints concerned the feet (60% subjects, knees, wrists and shoulders (over 40% subjects. After work-shift all examined workers had vertebral column shorter by 10 to 14 mm (11.4 mm mean. Conclusions: The results of our study show that the refuse collectors are subjected to a very high physical load because of the work organization and the way it is performed. To avoid adverse health effects and overload it is necessary to undertake ergonomic interventions, involving training of workers to improve the way of their job performance, active and passive leisure, technical control of the equipment and refuse containers, as well as the renegotiation of contracts with clients, especially those concerning non-standard containers. Med Pr 2013;64(4:507–519

  5. Theoretical study of fluidized solar collector performance

    Energy Technology Data Exchange (ETDEWEB)

    Adulla, S. H; Kassem, M A; El-Refaie, M. F. [Cairo University, Giza (Egypt)

    2000-07-01

    This work presents a proposed novel design aiming to increasing the absorber-to-fluid heat transfer coefficient. This is accomplished by introducing small solid particles inside the collector tubes. When the collector liquid flows, it causes the particles to be fluidized and spread in the tubes. The particles material, size and total number should be turned together with the fluid mass flow rate to keep the bed, or particle dispersion, length within the physical length of collector tubes. Thus, the particles would be confined in the collector only; and not carried over to other parts of the circulation loop. While moving, the particles erode the thermal boundary layer formed on the tube inner surface, hence increasing the heat transfer coefficient. [Spanish] Este articulo presenta un diseno novedoso destinado a aumentar el coeficiente de trasferencia de calor de absorbedor a fluido. Esto se lleva a cabo mediante la introduccion de particulas solidas dentro de los tubos del colector. Cuando fluye el liquido del colector origina que las particulas se fluidicen y se diseminen en los tubos. El material de las particulas, tamano y numero total debera de ser puesto en movimiento junto con el regimen de flujo de masa de fluido para mantener el lecho o la dispersion de particulas por largo tiempo dentro de la longitud fisica de los tubos de colector. De esta manera las particulas seran confinadas solamente en el colector y no seran arrastradas a otras partes del anillo de circulacion. Al moverse, las particulas erosionan la capa de frontera termica formada en la superficie interior del tubo, aumentando por tanto el coeficiente de transmision de calor.

  6. Simulation of a solar collector array consisting of two types of solar collectors, with and without convection barrier

    DEFF Research Database (Denmark)

    Bava, Federico; Furbo, Simon; Perers, Bengt

    2015-01-01

    The installed area of solar collectors in solar heating fields is rapidly increasing in Denmark. In this scenario even relatively small performance improvements may lead to a large increase in the overall energy production. Both collectors with and without polymer foil, functioning as convection...... barrier, can be found on the Danish market. Depending on the temperature level at which the two types of collectors operate, one can perform better than the other. This project aimed to study the behavior of a 14 solar collector row made of these two different kinds of collectors, in order to optimize...... the composition of the row. Actual solar collectors available on the Danish market (models HT-SA and HT-A 35-10 manufactured by ARCON Solar A/S) were used for this analysis. To perform the study, a simulation model in TRNSYS was developed based on the Danish solar collector field in Braedstrup. A parametric...

  7. Improved Collectors for High Power Gyrotrons

    International Nuclear Information System (INIS)

    Ives, R. Lawrence; Singh, Amarjit; Read, Michael; Borchard, Philipp; Neilson, Jeff

    2009-01-01

    High power gyrotrons are used for electron cyclotron heating, current drive and parasitic mode suppression in tokamaks for fusion energy research. These devices are crucial for successful operation of many research programs around the world, including the ITER program currently being constructed in France. Recent gyrotron failures resulted from cyclic fatigue of the copper material used to fabricated the collectors. The techniques used to collect the spent beam power is common in many gyrotrons produced around the world. There is serious concern that these tubes may also be at risk from cyclic fatigue. This program addresses the cause of the collector failure. The Phase I program successfully demonstrated feasibility of a mode of operation that eliminates the cyclic operation that caused the failure. It also demonstrated that new material can provide increased lifetime under cyclic operation that could increase the lifetime by more than on order of magnitude. The Phase II program will complete that research and develop a collector that eliminates the fatigue failures. Such a design would find application around the world.

  8. Evaluation of Test Method for Solar Collector Efficiency

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    The test method of the standard EN12975-2 (European Committee for Standardization, 2004) is used by European test laboratories to determine the efficiency of solar collectors. In the test methods the mean solar collector fluid temperature in the solar collector, Tm is determined by the approximat...... and the sky temperature. Based on the investigations, recommendations for change of the test methods and test conditions are considered. The investigations are carried out within the NEGST (New Generation of Solar Thermal Systems) project financed by EU.......The test method of the standard EN12975-2 (European Committee for Standardization, 2004) is used by European test laboratories to determine the efficiency of solar collectors. In the test methods the mean solar collector fluid temperature in the solar collector, Tm is determined by the approximated...... equation where Tin is the inlet temperature to the collector and Tout is the outlet temperature from the collector. The specific heat of the solar collector fluid is in the test method as an approximation determined as a constant equal to the specific heat of the solar collector fluid at the temperature Tm...

  9. Thermal performance of a transpired solar collector updraft tower

    International Nuclear Information System (INIS)

    Eryener, Dogan; Hollick, John; Kuscu, Hilmi

    2017-01-01

    Highlights: • Transpired solar collector updraft tower has been studied experimentally. • Transpired solar collector updraft tower efficiency ranges from 60 to 80%. • A comparison has been made with other SUT prototypes. • Three times higher efficiency compared to the glazed collectors of conventional solar towers. - Abstract: A novel solar updraft tower prototype, which consists of transpired solar collector, is studied, its function principle is described and its experimental thermal performance is presented for the first time. A test unit of transpired solar collector updraft tower was installed at the campus of Trakya University Engineering Faculty in Edirne-Turkey in 2014. Solar radiation, ambient temperature, collector cavity temperatures, and chimney velocities were monitored during summer and winter period. The results showed that transpired solar collector efficiency ranges from 60% to 80%. The maximum temperature rise in the collector area is found to be 16–18 °C on the typical sunny day. Compared to conventional solar tower glazed collectors, three times higher efficiency is obtained. With increased thermal efficiency, large solar collector areas for solar towers can be reduced in half or less.

  10. Application of local exhaust ventilation system and integrated collectors for control of air pollutants in mining company.

    Science.gov (United States)

    Ghorbani Shahna, Farshid; Bahrami, Abdulrahman; Farasati, Farhad

    2012-01-01

    Local exhaust ventilation (LEV) systems and integrated collectors were designed and implemented in a mining company in order to control emitted air pollutant from furnaces. The LEV was designed for capture and transition of air pollutants emitted from furnaces to the integrated collectors. The integrated collectors including four high efficiency Stairmand model cyclones for control of particulate matter, a venturi scrubber for control of the fine particles, SO(2) and a part of H(2)S to follow them, and a packed scrubber for treatment of the residual H(2)S and SO(2) were designed. Pollutants concentration were measured to determine system effectiveness. The results showed that the effectiveness of LEV for reducing workplace pollution is 91.83%, 96.32% and 83.67% for dust, SO(2) and H(2)S, respectively. Average removal efficiency of particles by combination of cyclone and venturi scrubber was 98.72%. Average removal efficiency of SO(2) and H(2)S were 95.85% and 47.13% for the venturi scrubber and 68.45% and 92.7% for the packed bed scrubber. The average removal efficiency of SO(2) and H(2)S were increased to 99.1% and 95.95% by the combination of venturi and packed bed scrubbers. According to the results, integrated collectors are a good air pollution control option for industries with economic constraints and ancient technologies.

  11. Analysis and validation of a quasi-dynamic model for a solar collector field with flat plate collectors and parabolic trough collectors in series for district heating

    DEFF Research Database (Denmark)

    Tian, Zhiyong; Perers, Bengt; Furbo, Simon

    2018-01-01

    performance of the hybrid solar district heating plants is also presented. The measured and simulated results show that the integration of parabolic trough collectors in solar district heating plants can guarantee that the system produces hot water with relatively constant outlet temperature. The daily energy......A quasi-dynamic TRNSYS simulation model for a solar collector field with flat plate collectors and parabolic trough collectors in series was described and validated. A simplified method was implemented in TRNSYS in order to carry out long-term energy production analyses of the whole solar heating...... plant. The advantages of the model include faster computation with fewer resources, flexibility of different collector types in solar heating plant configuration and satisfactory accuracy in both dynamic and long-term analyses. In situ measurements were taken from a pilot solar heating plant with 5960 m...

  12. LADEE LUNAR DUST EXPERIMENT

    Data.gov (United States)

    National Aeronautics and Space Administration — This archive bundle includes data taken by the Lunar Dust Experiment (LDEX) instrument aboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft....

  13. Construction dust amelioration techniques.

    Science.gov (United States)

    2012-04-01

    Dust produced on seasonal road construction sites in Alaska is both a traffic safety and environmental concern. Dust emanating from : unpaved road surfaces during construction severely reduces visibility and impacts stopping sight distance, and contr...

  14. On Dust Charging Equation

    OpenAIRE

    Tsintsadze, Nodar L.; Tsintsadze, Levan N.

    2008-01-01

    A general derivation of the charging equation of a dust grain is presented, and indicated where and when it can be used. A problem of linear fluctuations of charges on the surface of the dust grain is discussed.

  15. Physics of interstellar dust

    CERN Document Server

    Krugel, Endrik

    2002-01-01

    The dielectric permeability; How to evaluate grain cross sections; Very small and very big particles; Case studies of Mie calculus; Particle statistics; The radiative transition probability; Structure and composition of dust; Dust radiation; Dust and its environment; Polarization; Grain alignment; PAHs and spectral features of dust; Radiative transport; Diffuse matter in the Milky Way; Stars and their formation; Emission from young stars. Appendices Mathematical formulae; List of symbols.

  16. Dust as a surfactant

    International Nuclear Information System (INIS)

    Ignatov, A M; Schram, P P J M; Trigger, S A

    2003-01-01

    We argue that dust immersed in a plasma sheath acts as a surfactant. By considering the momentum balance in a plasma sheath, we evaluate the dependence of the plasma surface pressure on the dust density. It is shown that the dust may reduce the surface pressure, giving rise to a sufficiently strong tangential force. The latter is capable of confining the dust layer inside the sheath in the direction perpendicular to the ion flow

  17. Simulation of HPIB propagation in biased charge collector

    International Nuclear Information System (INIS)

    Li Hongyu; Qiu Aici

    2004-01-01

    A 2.5D PIC simulation using KARAT code for inner charge propagation within biased charge collector for measuring HPIB is presented. The simulation results indicate that the charges were neutralized but the current non-neutralized in the biased charge collector. The influence of ions collected vs biased voltage of the collector was also simulated. -800 V biased voltage can meet the measurement of 500 keV HPIB, and this is consistent with the experimental results

  18. A comparison of two cloudwater/fogwater collectors: The rotating arm collector and the caltech active strand cloudwater collector

    Science.gov (United States)

    Collett, Jeffrey L.; Daube, Bruce C.; Munger, J. William; Hoffmann, Michael R.

    A side-by-side comparison of the Rotating Arm Collector (RAC) and the Caltech Active Strand Cloudwater Collector (CASCC) was conducted at an elevated coastal site near the eastern end of the Santa Barbara Channel in southern California. The CASCC was observed to collect cloudwater at rates of up to 8.5 ml min -1. The ratio of cloudwater collection rates was found to be close to the theoretical prediction of 4.2:1 (CASCC:RAC) over a wide range of liquid water contents (LWC). At low LWC, however, this ratio climbed rapidly, possibly reflecting a predominance of small droplets under these conditions, coupled with a greater collection efficiency of small droplets by the CASCC. Cloudwater samples collected by the RAC had significantly higher concentrations of Na +, Ca 2+, Mg 2+ and Cl - than those collected by the CASCC. These higher concentrations may be due to differences in the chemical composition of large vs small droplets. No significant differences were observed in concentrations of NO 3-, SO 42- or NH 4+ in samples collected by the two instruments.

  19. Dust collection capacity of plants growing in coal mining areas

    International Nuclear Information System (INIS)

    Maiti, S.K.

    1993-01-01

    Plant can act as living filter of dust pollution in coal mining areas, where the amount of suspended particulate matter and dust fall rate is very high. Therefore, plant species growing in coal mining areas are classified as evergreen or deciduous with simple and compound leaf basis. The dust arresting capacity of each leaf is measured and expressed in g/m 2 . The study indicated that evergreen plants with simple, pilose surface, like - Alstonia, Ficus cunea, F. benghalensis and Mangifera indica are good dust catcher than evergreen compound leaves of Cassia siamea, Acacia arabica and Leucaena leucocephala. Deciduous with simple leaves, such as Zizyphus mauritiana, F. religiosa, Psidium guyava are also good dust collectors. Suitable plant species also help in quick reclamation of mined out areas; one practical difficulty for establishment of trees as green belts or reclamation purpose, has been incidence of cattle grazing. This study suggested a systematic way of selecting plant species on the basis of their efficiency in dust control and resistance to cattle grazing. (author). 16 refs., 3 tabs

  20. High Performance Flat Plate Solar Thermal Collector Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Rockenbaugh, Caleb [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dean, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lovullo, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lisell, Lars [National Renewable Energy Lab. (NREL), Golden, CO (United States); Barker, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hanckock, Ed [National Renewable Energy Lab. (NREL), Golden, CO (United States); Norton, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-09-01

    This report was prepared for the General Services Administration by the National Renewable Energy Laboratory. The Honeycomb Solar Thermal Collector (HSTC) is a flat plate solar thermal collector that shows promising high efficiencies over a wide range of climate zones. The technical objectives of this study are to: 1) verify collector performance, 2) compare that performance to other market-available collectors, 3) verify overheat protection, and 4) analyze the economic performance of the HSTC both at the demonstration sites and across a matrix of climate zones and utility markets.

  1. Adaptive control of solar energy collector systems

    CERN Document Server

    Lemos, João M; Igreja, José M

    2014-01-01

    This book describes methods for adaptive control of distributed-collector solar fields: plants that collect solar energy and deliver it in thermal form. Controller design methods are presented that can overcome difficulties found in these type of plants:they are distributed-parameter systems, i.e., systems with dynamics that depend on space as well as time;their dynamics is nonlinear, with a bilinear structure;there is a significant level of uncertainty in plant knowledge.Adaptive methods form the focus of the text because of the degree of uncertainty in the knowledge of plant dynamics. Parts

  2. Combined solar collector and storage systems

    International Nuclear Information System (INIS)

    Norton, B.; Smyth, M.; Eames, P.; Lo, S.N.G.

    2000-01-01

    The article discusses reasons why fossil-fuelled water heating systems are included in new houses but solar systems are not. The technology and market potential for evacuated tube systems and integral collector storage systems (ICSS) are explained. The challenge for the designers of ICSSWH has been how to reduce heat loss without compromising solar energy collection. A new concept for enhanced energy storage is described in detail and input/output data are given for two versions of ICSSWH units. A table compares the costs of ICSSWH in houses compared with other (i.e. fossil fuel) water heating systems

  3. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    International Nuclear Information System (INIS)

    Stanley J. Miller; Grant E. Dunham; Michelle R. Olderbak

    2001-01-01

    This project was awarded under U.S. Department of Energy (DOE) Program Solicitation DE-PS26-00NT40769 and specifically addresses Technical Topical Area 4-Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot-Scale. The project team will include the Energy and Environmental Research Center (EERC) as the main contractor, W.L. Gore and Associates, Inc., as a technical and financial partner, and the Big Stone Power Plant operated by Otter Tail Power Company, which will host the field testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control, called the advanced hybrid particulate collector (AHPC). The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emission with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas-solid contactor. The objective of the three-task project is to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach includes bench-scale batch testing that ties the new work to previous results and links results with larger-scale pilot testing with real flue gas on a coal-fired combustion system, pilot-scale testing on a coal-fired combustion system with both a pulse-jet baghouse and an AHPC to prove or disprove the research hypotheses, and field demonstration pilot-scale testing at a utility power plant to prove scaleup and demonstrate longer-term mercury control. This project, if successful, will demonstrate at the pilot-scale level a

  4. Mercury Control With The Advanced Hybrid Particulate Collector

    International Nuclear Information System (INIS)

    Stanley J. Miller; Ye Zhuang; Jay C. Almlie

    2004-01-01

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory Program Solicitation DE-FC26-01NT41184 and specifically addresses Technical Topical Area 4 - Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team included the Energy and Environmental Research Center as the main contractor; W.L. Gore and Associates, Inc., as a technical and financial partner; and the Big Stone Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore and Associates, Inc., and is marketed as the Advanced Hybrid(trademark) filter by Gore. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The AHPC also appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas--solid contactor. The objective of the original five-task project was to demonstrate 90% total mercury control in the AHPC at a lower cost than current mercury control estimates. The approach included benchscale batch tests, larger-scale pilot testing with real flue gas on a coal-fired combustion system, and field demonstration at the 2.5-MW scale at a utility power plant to prove scale-up and demonstrate longer-term mercury control. The scope of work was modified to include an additional sixth task, initiated in April 2003. The objective of this task was to

  5. Video tracking and post-mortem analysis of dust particles from all tungsten ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Endstrasser, N., E-mail: Nikolaus.Endstrasser@ipp.mpg.de [Max-Planck-Insitut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Brochard, F. [Institut Jean Lamour, Nancy-Universite, Bvd. des Aiguillettes, F-54506 Vandoeuvre (France); Rohde, V., E-mail: Volker.Rohde@ipp.mpg.de [Max-Planck-Insitut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Balden, M. [Max-Planck-Insitut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany); Lunt, T.; Bardin, S.; Briancon, J.-L. [Institut Jean Lamour, Nancy-Universite, Bvd. des Aiguillettes, F-54506 Vandoeuvre (France); Neu, R. [Max-Planck-Insitut fuer Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching (Germany)

    2011-08-01

    2D dust particle trajectories are extracted from fast framing camera videos of ASDEX Upgrade (AUG) by a new time- and resource-efficient code and classified into stationary hot spots, single-frame events and real dust particle fly-bys. Using hybrid global and local intensity thresholding and linear trajectory extrapolation individual particles could be tracked up to 80 ms. Even under challenging conditions such as high particle density and strong vacuum vessel illumination all particles detected for more than 50 frames are tracked correctly. During campaign 2009 dust has been trapped on five silicon wafer dust collectors strategically positioned within the vacuum vessel of the full tungsten AUG. Characterisation of the outer morphology and determination of the elemental composition of 5 x 10{sup 4} particles were performed via automated SEM-EDX analysis. A dust classification scheme based on these parameters was defined with the goal to link the particles to their most probable production sites.

  6. Field evaluation of air-blocking shelf for dust control on blasthole drills

    Energy Technology Data Exchange (ETDEWEB)

    J. Drew Potts; W. Randolph Reed [Office of Mine Safety and Health Research, NIOSH, Pittsburgh, PA (United States). Dust Control, Ventilation, and Toxic Substance Branch

    2011-03-15

    In previous studies, an air-blocking shelf has been shown to be successful in reducing respirable dust leakage from the drill shroud in a laboratory setting. Dust reductions of up to 81% were achieved with the shelf under operating conditions consisting of a 1.9:1 collector-to-bailing airflow ratio and a 5.1-cm gap between the shroud and ground. Recent research focused on evaluating the shelf on two actual operating blasthole drills, in much more severe environments. In the field, the shelf reduced dust levels in the areas surrounding one operating blasthole drill by 70%. Dust reductions measured in the immediate vicinity of the shroud were reduced by 66% at one mine and 81% at the other mine. These field tests confirm that the air-blocking shelf is useful for reducing respirable dust generation from blasthole drills.

  7. Road fugitive dust emission characteristics in Beijing during Olympics Game 2008 in Beijing, China

    Science.gov (United States)

    Shou-bin, Fan; Gang, Tian; Gang, Li; Yu-hu, Huang; Jian-ping, Qin; Shui-yuan, Cheng

    2009-12-01

    Eighty road dust-fall (DF) monitoring sites and 14 background monitoring sites were established in the Beijing metropolitan area, and monitoring was conducted from January 2006 to December 2008. The dust-fall attributable to roads (ΔDF) showed a clear decline from 2006 to 2008. Dust-fall levels decreased across different road types from freeway > major arterial roads > minor arterial roads > collector roads > background sites. The ΔDF showed declines of 65%, 55%, 65% and 84% respectively for freeways, major arterial, minor arterial and collector roads from August 2007 to August 2008, and declines of 77%, 76%, 82% and 82% between August 2006 and August 2008. The ΔDF declined by 80%, 79%, 82% and 69% for freeways, major arterial, minor arterial and collector roads respectively between September 2007 and September 2008, and declined by 84%, 88%, 80% and 81% between September 2006 and September 2008. Eighty samples were collected in August 2007 and August 2008 and analyzed for silt loading. PM 10 emission factors and emission strengths were calculated using the AP-42 model. The silt loading reduced by 77%, 35%, 61%, 59% and 75% for freeways, major arterial, minor arterial, collector and local roads respectively. The PM 10 emission factors were reduced by 57%, 15%, 36%, 51% and 61% and the PM 10 emission strength declined by 70%, 40%, 55%, 65% and 72% for freeways, major arterial, minor arterial, collector and local roads respectively between August 2007 and August 2008. The decline is consistent with the reduction in road dust-fall.

  8. DT results of TFTR's alpha collector

    International Nuclear Information System (INIS)

    Herrmann, H.W.; Zweben, S.J.; Darrow, D.S.; Timberlake, J.R.; Macaulay-Newcombe, R.G.

    1996-01-01

    An escaping alpha collector probe has been developed for TFTR's DT phase to complement the results of the lost alpha scintillator detectors which have been operating on TFTR since 1988. Measurements of the energy distribution of escaping alphas have been made by measuring the range of alphas implanted into nickel foils located within the alpha collector. Exposed samples have been analyzed for 4 DT plasma discharges at plasma currents of 1.0 and 1.8 MA. The results at 1.0 MA are in good agreement with predictions for first orbit alpha loss at 3.5 MeV. The 1.8 MA results, however, indicate a large anomalous loss of partially thermalized alphas at an energy ∼30% below the birth energy and at a total fluence nearly an order of magnitude above expected first orbit loss. This anomalous loss is not observed with the lost alpha scintillator detectors in DT plasmas but does resemble the anomalous delayed loss seen in DD plasmas. Several potential explanations for this loss process are examined. None of the candidate explanations proposed thus far are fully consistent with the anomalous loss observations

  9. Protecting solar collector systems from corrosion

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    The main cause of the reduced life of a solar heating system is corrosion of the exterior parts and the internal components. This report outlines ways of reducing the cost of solar heating by reducing the corrosion in solar heating systems, and hence increasing the system's service life. Mechanisms for corrosion are discussed: these include galvanic corrosion and crevice corrosion. Means of minimizing corrosion at the design stage are then described. Such methods, when designing the solar collector, involve ensuring proper drainage of exterior water; eliminating situations where moisture, dirt and pollutants may collect; preventing condensation inside the collector; using proper gaskets and sealants at appropriate places; and selecting optimum materials and coatings. Interior corrosion can be minimized at the design stage by choosing a good heat transfer fluid and corrosion inhibitor, in the case of systems where liquids are used; ensuring a low enough flow rate to avoid erosion; designing the system to avoid crevices; and avoiding situations where galvanic corrosion could occur. Other procedures are given for minimizing corrosion in the construction and operation of solar heating systems. 7 figs., 7 tabs.

  10. Properties of Modern Dust Accumulating in the Uinta Mountains, Utah, USA, and Soil Evidence of Long-Term Dust Deposition

    Science.gov (United States)

    Munroe, J. S.

    2013-12-01

    Modern eolian sediment was collected at four locations in the alpine zone of the Uinta Mountains (Utah, USA) between July 2011 and July 2012. Collectors were a passive design based on the classic marble dust trap, but modified for use in this high-precipitation environment. On average the collectors accumulated 1.5 gm of dust, corresponding to an annual flux of 4.4 g/m2. This result is similar to values measured from snowpack samples in the Wind River (Wyoming) and San Juan (Colorado) Mountains. Dust flux was 3 to 5x higher during the winter compared with summer at the two sites featuring continuous vegetation, but was consistent between the seasons at the two collectors surrounded by a greater area of exposed soil. XRD analysis reveals that dust samples are dominated by quartz, potassium feldspar, plagioclase, and illite. Some samples contain amphibole and chlorite. In contrast, samples of fine sediment collected from the surface of modern snowbanks are dominated by clay with no feldspar or quartz, suggesting that these minerals are derived from the surrounding soil surface, which is snow-covered in the winter. ICP-MS analysis reveals that the geochemistry of the coarse (>63-μm) fraction of the dust resembles that of the underlying bedrock, confirming a local origin for this sediment. In contrast, the fine (horizon, supporting an eolian origin for the ubiquitous layer of fines that mantles soil profiles throughout the Uinta Mountains. Grain size analysis with laser scattering reveals that modern dust is very well-sorted, with a median size of 8 μm (7.0 Φ). Using the annual dust flux and mean grain size, and taking into account the measured bulk density (0.95 gm/cm3), organic matter content (20%), and silt content (32%) of this loess cap, the extrapolated loess accretion rate is ~18 cm per 10,000 years. Given that prior studies (Bockheim et al., 2000 Catena; Munroe, 2007, Arctic, Antarctic, and Alpine Research) have reported mean loess thickness from 16 to 25 cm

  11. Physically absorbable reagents-collectors in elementary flotation

    Energy Technology Data Exchange (ETDEWEB)

    S.A. Kondrat' ev; I.G. Bochkarev [Russian Academy of Sciences, Novosibirsk (Russian Federation). Institute of Mining

    2007-09-15

    Based on the reviewed researches held at the Institute of Mining, Siberian Branch, Russian Academy of Sciences, the effect of physically absorbable reagents-collectors on formation of a flotation complex and its stability in turbulent pulp flows in flotation machines of basic types is considered. The basic requirements for physically absorbable reagents-collectors at different flotation stages are established.

  12. Preliminary design package for solar collector and solar pump

    Science.gov (United States)

    1978-01-01

    A solar-operated pump using an existing solar collector, for use on solar heating and cooling and hot water systems is described. Preliminary design criteria of the collector and solar-powered pump is given including: design drawings, verification plans, and hazard analysis.

  13. ANALYSIS AND MODELING OF SOLAR EVAPORATOR-COLLECTOR

    Directory of Open Access Journals (Sweden)

    Zakaria Mohd. Amin

    2015-11-01

    Full Text Available Solar energy is considered a sustainable resource that poses little to no harmful effects on the environment. The performance of a solar system depends to a great extent on the collector used for the conversion of solar radiant energy to thermal energy. A solar evaporator-collector (SEC is basically an unglazed flat plate collector where refrigerants, such as R134a is used as the working fluid. As the operating temperature of the SEC is very low, it utilizes both solar irradiation and ambient energy leading to a much higher efficiency than the conventional collectors. This capability of SECs to utilize ambient energy also enables the system to operate at night. This type of collector can be locally made and is relatively much cheaper than the conventional collector.   At the National University of Singapore, the evaporator-collector was integrated to a heat pump and the performance was investigated for several thermal applications: (i water heating, (ii drying and (iii desalination. A 2-dimensional transient mathematical model of this system was developed and validated by experimental data. The present study provides a comprehensive study of performance. KEYWORDS: heat pump; evaporator-collector.

  14. Efficiency improvement of flat plate solar collector using reflector

    Directory of Open Access Journals (Sweden)

    Himangshu Bhowmik

    2017-11-01

    Full Text Available Solar collectors are the main components of a solar heating system. The collectors collect the sun’s energy, transform this radiation into heat, and then transfer this heat into a fluid, water or air, which has many household or industrial applications. This paper introduces a new technology to improve the performance of the solar thermal collectors. The solar reflector used here with the solar collector to increase the reflectivity of the collector. Thus, the reflector concentrates both direct and diffuse radiation of the sun toward the collector. To maximize the intensity of incident radiation, the reflector was allowed to change its angle with daytime. The radiations coming from the sun’s energy were converted into heat, and then this heat was transferred to the collector fluid, water. A prototype of a solar water heating system was constructed and obtained the improvement of the collector efficiency around 10% by using the reflector. Thus, the present solar water heating systems having the best thermal performance compared to the available systems.

  15. Direct-heating solar-collector dump valve

    Science.gov (United States)

    Howikman, T. C.

    1977-01-01

    Five-port ganged valve isolates collector from primary load system pressure and drains collectors, allowing use of direct heating with all its advantages. Valve is opened and closed by same switch that controls pump or by temperature sensor set at O C, while providing direct dump option.

  16. Diagnostics of defeats of venous collectors of brain

    International Nuclear Information System (INIS)

    Timofeeva, T.V.; Polunina, I.S.; Shcherbakova, E.Ya.; Kuldakova, S.V.

    1997-01-01

    Comparative data of transcranial ultrasonic dopplerography (170 patients) and radionuclidous antroscintigraphy (124), received during diagnostics of defects of venous collectors of brain are analyzed. Five variants of defeats of venous collectors (cross, sigmoid, internal of jugular of jugular vein), but also unpaired sine (direct, confluent) are described. Received results permit to reveal interrelation of infringements of venous outflow and increase of intracranial pressure

  17. Advances in design of air-heating collectors

    CSIR Research Space (South Africa)

    Johannsen, A

    1982-11-01

    Full Text Available Principles of the operation of air-heating collectors are discussed. The fundamental differences between the design principles of air-heating as opposed to water-heating collectors are highlighted. The main requirement is the transfer of heat from...

  18. Thermal performances of vertical hybrid PV/T air collector

    Science.gov (United States)

    Tabet, I.; Touafek, K.; Bellel, N.; Khelifa, A.

    2016-11-01

    In this work, numerical analyses and the experimental validation of the thermal behavior of a vertical photovoltaic thermal air collector are investigated. The thermal model is developed using the energy balance equations of the PV/T air collector. Experimental tests are conducted to validate our mathematical model. The tests are performed in the southern Algerian region (Ghardaïa) under clear sky conditions. The prototype of the PV/T air collector is vertically erected and south oriented. The absorber upper plate temperature, glass cover temperature, air temperature in the inlet and outlet of the collector, ambient temperature, wind speed, and solar radiation are measured. The efficiency of the collector increases with increase in mass flow of air, but the increase in mass flow of air reduces the temperature of the system. The increase in efficiency of the PV/T air collector is due to the increase in the number of fins added. In the experiments, the air temperature difference between the inlet and the outlet of the PV/T air collector reaches 10 ° C on November 21, 2014, the interval time is between 10:00 and 14:00, and the temperature of the upper plate reaches 45 ° C at noon. The mathematical model describing the dynamic behavior of the typical PV/T air collector is evaluated by calculating the root mean square error and mean absolute percentage error. A good agreement between the experiment and the simulation results is obtained.

  19. A study of the flat plate solar collector in Guinea

    International Nuclear Information System (INIS)

    Boye Barry, M.

    1990-12-01

    In this paper, we study a collector, made by cheap local materials (wood, aluminium, etc.), and prepared in the carpenteries, and in the mechanic work rooms with a simple technology. The efficiency of our collector is compared with several variants made in other countries. (author). 9 refs, 6 figs, 2 tabs

  20. A fiery birth of aluminosilica analogs of refractory dust in the upper stratosphere

    Science.gov (United States)

    Rietmeijer, F. J. M.; Ferrari, M.; Della Corte, V.; Rotundi, A.; Palumbo, P.; De Angelis, S.; Galluzzi, V.

    2017-11-01

    Following a successful dust collection flight in the upper stratosphere our DUSTER (Dust in the Upper Stratosphere Tracking Experiment and Retrieval) made a safe remote landing at its assigned location on Baffin Island during early June 2009. When the balloon payload that included DUSTER was retrieved it was found part of the payload had experienced a lithium-sparked fire while the payload was being dragged across the landing site. In this process the housing of DUSTER had developed a pin-sized hole that allowed smoke of the fire to enter the collector. Numerous smoke particles were found covering both the DUSTER collection and blank collector surfaces an indication that our experiment to collect upper stratospheric dust had failed! Both collector surfaces were covered by numerous carbon smoke and amorphous, aluminosilica nanoparticles. The compositions of vast majority of these aluminosilica nanoparticles, Al2O3 = 49 wt% and SiO2 = 51 wt%, was both surprising and unique because it was an exact match of the Deep Metastable Eutectic (DME) nanoparticles found in vapor phase condensation experiments. These vapor phase condensation experiments were conducted to explore the formation of extraterrestrial dust particles. We are not claiming an extraterrestrial origin for these particles from this DUSTER experiment. We submit that given the appropriate conditions of high temperature alumina and silica vapors and rapid quenching in a contained natural environment, DME aluminosilica nanoparticles will likely condense. This serendipitous result can be used to explore nanoparticle formation inside incandescent clouds associated with bolides and fireballs.

  1. Annual measured and simulated thermal performance analysis of a hybrid solar district heating plant with flat plate collectors and parabolic trough collectors in series

    DEFF Research Database (Denmark)

    Tian, Zhiyong; Perers, Bengt; Furbo, Simon

    2017-01-01

    Flat plate collectors have relatively low efficiency at the typical supply temperatures of district heating networks (70–95 °C). Parabolic trough collectors retain their high efficiency at these temperatures. To maximize the advantages of flat plate collectors and parabolic trough collectors in l...... for this type of hybrid solar district heating plants with flat plate collectors and parabolic trough collectors in the Nordic region, but also introduce a novel design concept of solar district heating plants to other high solar radiation areas....... in large solar heating plants for a district heating network, a hybrid solar collector field with 5960 m2 flat plate collectors and 4039 m2 parabolic trough collectors in series was constructed in Taars, Denmark. The design principle is that the flat plate collectors preheat the return water from...

  2. The Lunar Dust Environment

    Science.gov (United States)

    Szalay, Jamey Robert

    Planetary bodies throughout the solar system are continually bombarded by dust particles, largely originating from cometary activities and asteroidal collisions. Surfaces of bodies with thick atmospheres, such as Venus, Earth, Mars and Titan are mostly protected from incoming dust impacts as these particles ablate in their atmospheres as 'shooting stars'. However, the majority of bodies in the solar system have no appreciable atmosphere and their surfaces are directly exposed to the flux of high speed dust grains. Impacts onto solid surfaces in space generate charged and neutral gas clouds, as well as solid secondary ejecta dust particles. Gravitationally bound ejecta clouds forming dust exospheres were recognized by in situ dust instruments around the icy moons of Jupiter and Saturn, and had not yet been observed near bodies with refractory regolith surfaces before NASA's Lunar Dust and Environment Explorer (LADEE) mission. In this thesis, we first present the measurements taken by the Lunar Dust Explorer (LDEX), aboard LADEE, which discovered a permanently present, asymmetric dust cloud surrounding the Moon. The global characteristics of the lunar dust cloud are discussed as a function of a variety of variables such as altitude, solar longitude, local time, and lunar phase. These results are compared with models for lunar dust cloud generation. Second, we present an analysis of the groupings of impacts measured by LDEX, which represent detections of dense ejecta plumes above the lunar surface. These measurements are put in the context of understanding the response of the lunar surface to meteoroid bombardment and how to use other airless bodies in the solar system as detectors for their local meteoroid environment. Third, we present the first in-situ dust measurements taken over the lunar sunrise terminator. Having found no excess of small grains in this region, we discuss its implications for the putative population of electrostatically lofted dust.

  3. Selective flotation of phosphate minerals with hydroxamate collectors

    Science.gov (United States)

    Miller, Jan D.; Wang, Xuming; Li, Minhua

    2002-01-01

    A method is disclosed for separating phosphate minerals from a mineral mixture, particularly from high-dolomite containing phosphate ores. The method involves conditioning the mineral mixture by contacting in an aqueous in environment with a collector in an amount sufficient for promoting flotation of phosphate minerals. The collector is a hydroxamate compound of the formula; ##STR1## wherein R is generally hydrophobic and chosen such that the collector has solubility or dispersion properties it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms. M is a cation, typically hydrogen, an alkali metal or an alkaline earth metal. Preferably, the collector also comprises an alcohol of the formula, R'--OH wherein R' is generally hydrophobic and chosen such that the collector has solubility or dispersion properties so that it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms.

  4. Performance of solar collectors under low temperature conditions

    DEFF Research Database (Denmark)

    Bunea, Mircea; Eicher, Sara; Hildbrand, Catherine

    The performance of four solar thermal collectors (flat plate, evacuated tube, unglazed with rear insulation and unglazed without rear insulation) was experimentally measured and simulated for temperatures below ambient. The influence of several parameters (e.g. collector inlet temperature, air...... evaluated and results compared to experimental measurements. A mathematical model is also under development to include, in addition to the condensation phenomena, the frost, the rain and the long-wave radiation gains/losses on the rear of the solar collector. While the potential gain from rain was estimated...... to be around 2%, frost heat gains were measured to be up to 40% per day, under specific conditions. Overall, results have shown that unglazed collectors are more efficient than flat plate or evacuated tube collectors at low operation temperatures or for night conditions, making them more suitable for heat pump...

  5. A solar air collector with integrated latent heat thermal storage

    Directory of Open Access Journals (Sweden)

    Klimes Lubomir

    2012-04-01

    Full Text Available Simulations of the behaviour of a solar air collector with integrated latent heat thermal storage were performed. The model of the collector was created with the use of coupling between TRNSYS 17 and MATLAB. Latent heat storage (Phase Change Material - PCM was integrated with the solar absorber. The model of the latent heat storage absorber was created in MATLAB and the model of the solar air collector itself was created in TRNSYS with the use of TYPE 56. The model of the latent heat storage absorber allows specification of the PCM properties as well as other parameters. The simulated air collector was the front and back pass collector with the absorber in the middle of the air cavity. Two variants were considered for comparison; the light-weight absorber made of sheet metal and the heat-storage absorber with the PCM. Simulations were performed for the climatic conditions of the Czech Republic (using TMY weather data.

  6. Analysis of a solar collector field water flow network

    Science.gov (United States)

    Rohde, J. E.; Knoll, R. H.

    1976-01-01

    A number of methods are presented for minimizing the water flow variation in the solar collector field for the Solar Building Test Facility at the Langley Research Center. The solar collector field investigated consisted of collector panels connected in parallel between inlet and exit collector manifolds to form 12 rows. The rows were in turn connected in parallel between the main inlet and exit field manifolds to complete the field. The various solutions considered included various size manifolds, manifold area change, different locations for the inlets and exits to the manifolds, and orifices or flow control valves. Calculations showed that flow variations of less than 5 percent were obtainable both inside a row between solar collector panels and between various rows.

  7. Thermal analysis of gyrotron traveling-wave tube collector

    International Nuclear Information System (INIS)

    Zheng Zhiqing; Luo Yong; Jiang Wei; Tang Yong

    2013-01-01

    In order to solve cooling problem of the gyrotron traveling-wave tube(TWT) collector and guarantee the gyrotron TWT's reliability and stability, the electron trajectories in the gyrotron TWT are simulated using CST electron simulation software. Thermal analysis of the collector with finite element software ANSYS is performed. The ways of applying boundary that affects the distribution of collector temperature are compared. The influence of the water temperature and flow rate on collector temperature distribution under actual heat fluxes (boundary condition) is researched. The size and number of collector fins are optimized, and a relatively perfect structure is obtained finally. The result estimated by simulation is consistent with the experiment and proves that the model and method employed in this work are suitable. (authors)

  8. Mathematical modelling of unglazed solar collectors under extreme operating conditions

    DEFF Research Database (Denmark)

    Bunea, M.; Perers, Bengt; Eicher, S.

    2015-01-01

    average temperature levels at the evaporator. Simulation of these systems requires a collector model that can take into account operation at very low temperatures (below freezing) and under various weather conditions, particularly operation without solar irradiation.A solar collector mathematical model......Combined heat pumps and solar collectors got a renewed interest on the heating system market worldwide. Connected to the heat pump evaporator, unglazed solar collectors can considerably increase their efficiency, but they also raise the coefficient of performance of the heat pump with higher...... was found due to the condensation phenomenon and up to 40% due to frost under no solar irradiation. This work also points out the influence of the operating conditions on the collector's characteristics.Based on experiments carried out at a test facility, every heat flux on the absorber was separately...

  9. Test results, Industrial Solar Technology parabolic trough solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Dudley, V.E. [EG and G MSI, Albuquerque, NM (United States); Evans, L.R.; Matthews, C.W. [Sandia National Labs., Albuquerque, NM (United States)

    1995-11-01

    Sandia National Laboratories and Industrial Solar Technology are cost-sharing development of advanced parabolic trough technology. As part of this effort, several configurations of an IST solar collector were tested to determine the collector efficiency and thermal losses with black chrome and black nickel receiver selective coatings, combined with aluminized film and silver film reflectors, using standard Pyrex{reg_sign} and anti-reflective coated Pyrex{reg_sign} glass receiver envelopes. The development effort has been successful, producing an advanced collector with 77% optical efficiency, using silver-film reflectors, a black nickel receiver coating, and a solgel anti-reflective glass receiver envelope. For each receiver configuration, performance equations were empirically derived relating collector efficiency and thermal losses to the operating temperature. Finally, equations were derived showing collector performance as a function of input insolation value, incident angle, and operating temperature.

  10. Analysis of WWER 1000 collector cracking mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Matocha, K.; Wozniak, J. [Vitkovice J.S.C., Ostrava (Switzerland)

    1997-12-31

    The presentation reviews the large experimental program, started in 1993 in Vitkovice, where the main aim was: (1) a detailed study of strain and thermal ageing, dissolved oxygen content and temperature on subcritical crack growth in 10NiMo8.5 (10GN2MFA) steel, (2) a detailed study of the effect of high temperature water and tube expansion technology on fracture behaviour of ligaments between holes for heat exchange tubes, and (3) a detailed study of the effect of drilling, tube expansion technology and heat treatment on residual stresses on the surface of holes for heat exchange tubes. The aim of all these investigations was to find a dominant damage mechanism responsible for collector cracking to be able to judge the efficiency of implemented modifications and suggested countermeasures and to answer a very important question whether proper operation conditions (mainly water chemistry) make the operation of steam generators made in Vitcovice safe throughout the planned lifetime. 10 refs.

  11. Analysis of WWER 1000 collector cracking mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Matocha, K; Wozniak, J [Vitkovice J.S.C., Ostrava (Switzerland)

    1998-12-31

    The presentation reviews the large experimental program, started in 1993 in Vitkovice, where the main aim was: (1) a detailed study of strain and thermal ageing, dissolved oxygen content and temperature on subcritical crack growth in 10NiMo8.5 (10GN2MFA) steel, (2) a detailed study of the effect of high temperature water and tube expansion technology on fracture behaviour of ligaments between holes for heat exchange tubes, and (3) a detailed study of the effect of drilling, tube expansion technology and heat treatment on residual stresses on the surface of holes for heat exchange tubes. The aim of all these investigations was to find a dominant damage mechanism responsible for collector cracking to be able to judge the efficiency of implemented modifications and suggested countermeasures and to answer a very important question whether proper operation conditions (mainly water chemistry) make the operation of steam generators made in Vitcovice safe throughout the planned lifetime. 10 refs.

  12. Study of Cylindrical Honeycomb Solar Collector

    Directory of Open Access Journals (Sweden)

    Atish Mozumder

    2014-01-01

    Full Text Available We present the results of our investigation on cylindrical honeycomb solar collector. The honeycomb has been fabricated with transparent cellulose triacetate polymer sheets. Insulation characteristics of the honeycomb were studied by varying the separation between the honeycomb and the absorber plate. The optimal value of the separation was found to be 3.3 mm for which the heat transfer coefficient is 3.06 W m−2 K−1. This supports result of previous similar experiments. Further we test the honeycomb through a field experiment conducted in Delhi (28.6°N, 77°E and found that when the incident angle of the solar radiation is within 20° then the performance of the system with the honeycomb is better than the one without the honeycomb.

  13. Update on Automated Classification of Interplanetary Dust Particles

    Science.gov (United States)

    Maroger, I.; Lasue, J.; Zolensky, M.

    2018-01-01

    Every year, the Earth accretes about 40,000 tons of extraterrestrial material less than 1 mm in size on its surface. These dust particles originate from active comets, from impacts between asteroids and may also be coming from interstellar space for the very small particles. Since 1981, NASA Jonhson Space Center (JSC) has been systematically collecting the dust from Earth's strastosphere by airborne collectors and gathered them into "Cosmic Dust Catalogs". In those catalogs, a preliminary analysis of the dust particles based on SEM images, some geological characteristics and X-ray energy-dispersive spectrometry (EDS) composition is compiled. Based on those properties, the IDPs are classified into four main groups: C (Cosmic), TCN (Natural Terrestrial Contaminant), TCA (Artificial Terrestrial Contaminant) and AOS (Aluminium Oxide Sphere). Nevertheless, 20% of those particles remain ambiguously classified. Lasue et al. presented a methodology to help automatically classify the particles published in the catalog 15 based on their EDS spectra and nonlinear multivariate projections (as shown in Fig. 1). This work allowed to relabel 155 particles out of the 467 particles in catalog 15 and reclassify some contaminants as potential cosmic dusts. Further analyses of three such particles indicated their probable cosmic origin. The current work aims to bring complementary information to the automatic classification of IDPs to improve identification criteria.

  14. Controlling fugitive dust emissions in material handling operations

    Energy Technology Data Exchange (ETDEWEB)

    Tooker, G E

    1992-05-01

    The primary mechanism of fugitive dust generation in bulk material handling transfer operations is by dispersion of dust in turbulent air induced to flow with falling or projected material streams. This paper returns to basic theories of particle dynamics and fluid mechanics to quantify the dust generating mechanism by rational analysis. Calculations involving fluid mechanisms are made easier by the availability of the personal computer and the many math manipulating programs. Rational analysis is much more cost effective when estimating collection air volumes to control fugitive emissions; especially in enclosed material handling transfers transporting large volumes of dusty material. Example calculations, using a typical enclosed conveyor-to-conveyor transfer operation are presented to illustrate and highlight the key parameters that determine the magnitude of induced air flow that must be controlled. The methods presented in this paper for estimating collection air volumes apply only enclosed material handling transfers, exhausted to a dust collector. Since some assistance to the control of dust emissions must be given by the material handling transfer chute design, a discussion of good transfer chute design practice is presented. 4 refs., 2 figs., 2 tabs.

  15. Dust Devil Tracks

    Science.gov (United States)

    2002-01-01

    (Released 8 May 2002) The Science This image, centered near 50.0 S and 17.7 W displays dust devil tracks on the surface. Most of the lighter portions of the image likely have a thin veneer of dust settled on the surface. As a dust devil passes over the surface, it acts as a vacuum and picks up the dust, leaving the darker substrate exposed. In this image there is a general trend of many of the tracks running from east to west or west to east, indicating the general wind direction. There is often no general trend present in dust devil tracks seen in other images. The track patterns are quite ephemeral and can completely change or even disappear over the course of a few months. Dust devils are one of the mechanisms that Mars uses to constantly pump dust into the ubiquitously dusty atmosphere. This atmospheric dust is one of the main driving forces of the present Martian climate. The Story Vrrrrooooooooom. Think of a tornado, the cartoon Tasmanian devil, or any number of vacuum commercials that powerfully suck up swirls of dust and dirt. That's pretty much what it's like on the surface of Mars a lot of the time. Whirlpools of wind called

  16. Selected properties of flue dust from the technologies on magnesite processing in Slovmag, inc. Lubeník

    Directory of Open Access Journals (Sweden)

    Bobro Milan

    1997-09-01

    Full Text Available The contribution deals with the properties of specimens obtained by sampling dust collectors in the selected production centres. The grain size distribution, morphological, mineral, and chemical properties were studied with the aim to determine their infuence on the environment. This research attests that the main component of studied flue dusts is MgO in two form: periclase and amorphous phase. The latter form is harmful. That is why continual observation of the quality of flue dust from the stand point of their exertion on the air and soil is needed.

  17. Air solar collectors in building use - A review

    Science.gov (United States)

    Bejan, Andrei-Stelian; Labihi, Abdelouhab; Croitoru, Cristiana; Catalina, Tiberiu

    2018-02-01

    In the current energy and environmental context it is imperative to implement systems based on renewable energy sources in order to reduce energy consumptions worldwide. Solar collectors are studied by many years and many researchers are focusing their attention in order to increase their efficiency and cost-effectiveness. Water solar collectors are often implemented for domestic hot water, heating or industrial processes and already have a place on the market. A promising system which is not yet widely known is represented by air solar collectors that could represent an efficient way to use the solar energy with a lower investment cost, a system that can be used in order to preheat the fresh air required for heating, drying, or to maintain a minimum temperature during winter. This paper presents a comprehensive literature review on air solar collectors used mainly in buildings, acting as a solar wall. Air solar collectors are roughly classified into two types: glazed and opaque. The present study comprises the solar collector classification, applications and their main parameters with a special focus on opaque solar collectors.

  18. Pathways toward a low cost evacuated collector system

    Science.gov (United States)

    Hull, J. R.; Schertz, W. W.; Allen, J. W.; Ogallagher, J. J.; Winston, R.

    The goal of widespread use of solar thermal collectors will only be achieved when they are proven to be economically superior to competing energy sources. Evacuated tubular collectors appear to have the potential to achieve this goal. An advanced evacuated collector using nonimaging concentration under development at the University of Chicago and Argonne can achieve a 50% seasonal efficiency at heat delivery temperatures in excess of 170C. The same collector has an optical efficiency so that low temperature performance is also excellent. In this advanced collector design all of the critical components are enclosed in the vacuum, and the collector has an inherently long lifetime. The current cost of evacuated systems is too high, mainly because the volume of production has been too low to realize economies of mass production. It appears that certain design features of evacuated collectors can be changed (e.g., use of heat pipe absorbers) so as to introduce new system design and market strategy options that can reduce the balance of system cost.

  19. Evaluation of heat transfer enhancement in air-heating collectors

    Energy Technology Data Exchange (ETDEWEB)

    Mattox, D. L.

    1979-06-01

    The present research effort was initiated for the purpose of increasing the thermal efficiency of air heating solar collectors through identification and development of optimum design and operation criteria for solar absorber-to-air heat exchangers. Initially this effort took the form of a solar collector systems analysis to evaluate the impact of various techniques for enhancing the heat transfer between the absorber and air stream on overall thermal performance of the entire solar collector. This systems analysis resulted in the selection of solar collector designs providing ducted cooling air on the absorber shaded side as a base line. A transient heat transfer analysis of a complete solar air heating collector was used to demonstrate that an optimum absorber-to-air heat exchanger design could be provided with several interrupted fin configurations. Additional analyses were performed to establish that the maximum solar collector thermal performance to required pumping power was realized for a Reynolds number range of 1000 to 2000. This Reynolds number range was used to establish a theoretical design limit curve for maximum thermal performance versus required pumping power for all interrupted fin designs as published in the open literature. Heat and momentum transfer empirical relationships were defined for scaling the state-of-the-art high conductance fin designs identified from a compact configuration to the less compact designs needed for solar collectors.

  20. PERFORMANCE EVALUATION OF SOLAR COLLECTORS USING A SOLAR SIMULATOR

    Directory of Open Access Journals (Sweden)

    M. Norhafana

    2015-11-01

    Full Text Available Solar water heating systems is one of the applications of solar energy. One of the components of a solar water heating system is a solar collector that consists of an absorber. The performance of the solar water heating system depends on the absorber in the solar collector. In countries with unsuitable weather conditions, the indoor testing of solar collectors with the use of a solar simulator is preferred. Thus, this study is conducted to use a multilayered absorber in the solar collector of a solar water heating system as well as to evaluate the performance of the solar collector in terms of useful heat of the multilayered absorber using the multidirectional ability of a solar simulator at several values of solar radiation. It is operated at three variables of solar radiation of 400 W/m2, 550 W/m2 and 700 W/m2 and using three different positions of angles at 0º, 45º and 90º. The results show that the multilayer absorber in the solar collector is only able to best adapt at 45° of solar simulator with different values of radiation intensity. At this angle the maximum values of useful heat and temperature difference are achieved. KEYWORDS: solar water heating system; solar collector; multilayered absorber; solar simulator; solar radiation 

  1. Air solar collectors in building use - A review

    Directory of Open Access Journals (Sweden)

    Bejan Andrei-Stelian

    2018-01-01

    Full Text Available In the current energy and environmental context it is imperative to implement systems based on renewable energy sources in order to reduce energy consumptions worldwide. Solar collectors are studied by many years and many researchers are focusing their attention in order to increase their efficiency and cost-effectiveness. Water solar collectors are often implemented for domestic hot water, heating or industrial processes and already have a place on the market. A promising system which is not yet widely known is represented by air solar collectors that could represent an efficient way to use the solar energy with a lower investment cost, a system that can be used in order to preheat the fresh air required for heating, drying, or to maintain a minimum temperature during winter. This paper presents a comprehensive literature review on air solar collectors used mainly in buildings, acting as a solar wall. Air solar collectors are roughly classified into two types: glazed and opaque. The present study comprises the solar collector classification, applications and their main parameters with a special focus on opaque solar collectors.

  2. Whither Cometary Dust?

    Science.gov (United States)

    Lisse, Carey M.

    2010-10-01

    In this paper I will discuss recent findings that have important implications for our understanding of the formation and evolution of primitive solar system dust, including: - Nesvorny et al. (2010), following up on their dynamical analyses of the zodiacal dust bands as sourced by the breakup of the Karin (5Mya) and Veritas (8Mya) asteroid families, argue that over 90% of the interplanetary dust cloud at 1 AU comes from JFC comets with near-circularized, low inclination orbits. This implies that the noted IPD collections of anhydrous and hydrous dust particles are likely to be from Oort cloud and JFC comets, respectively, not from asteroids and comets as thought in the past. Hydrous dust particles from comets like 85P/Wild2 and 9P/Tempel 1 would be consistent with results from the STARDUST and Deep Impact experiments. - Estimates of the dust particle size distributions (PSDs) in the comae of 85P/Wild2 (Green et al. 2004, 2007) and 73P/SW-3 (Sitko et al. 2010, Vaubaillon & Reach 2010) and in the trails of comets (Reach et al. 2007) have broken power law structure, with a plateau enhancement of particles of 1 mm - 1 cm in size. This size is also the size of most chondritic inclusions, and the predicted size range of the "aggregational barrier", where collisions between dust particles become destructive. - Studies of the albedo and polarization properties of cometary dust (Kolokolova et al. 2007) suggest there are 2 major groupings, one with low scattering capability and one with high. While these families could possibly have been explained by systematics in the PSDs of the emitted dust, independent work by Lisse et al. (2008) on the mineralogy of a number of highly dusty comets has shown evidence for one family of comets with highly crystalline dust and another with highly amorphous dust.

  3. Communication plan for windblown dust.

    Science.gov (United States)

    2015-05-01

    Windblown dust events occur in Arizona, and blowing dust has been considered a contributing factor to serious crashes on the : segment of Interstate 10 (I10) between Phoenix and Tucson, as well as on other Arizona roadways. Arizonas dust events...

  4. Fuzzy Approximate Model for Distributed Thermal Solar Collectors Control

    KAUST Repository

    Elmetennani, Shahrazed

    2014-07-01

    This paper deals with the problem of controlling concentrated solar collectors where the objective consists of making the outlet temperature of the collector tracking a desired reference. The performance of the novel approximate model based on fuzzy theory, which has been introduced by the authors in [1], is evaluated comparing to other methods in the literature. The proposed approximation is a low order state representation derived from the physical distributed model. It reproduces the temperature transfer dynamics through the collectors accurately and allows the simplification of the control design. Simulation results show interesting performance of the proposed controller.

  5. FLOW DISTRIBUTION IN A SOLAR COLLECTOR PANEL WITH HORIZONTAL FINS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    2005-01-01

    The objective of this work is to theoretically and experimentally investigate the flow and temperature distribution in a solar collector panel with an absorber consisting of horizontal fins. Fluid flow and heat transfer in the collector panel are studied by means of computational fluid dynamics...... (CFD) calculations. Further, experimental investigations of a 12.5 m² solar collector panel with 16 parallel connected horizontal fins are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the backside of the absorber tubes. The measured...

  6. Theoretical flow investigations of an all glass evacuated tubular collector

    DEFF Research Database (Denmark)

    Shah, Louise Jivan; Furbo, Simon

    2007-01-01

    Heat transfer and flow structures inside all glass evacuated tubular collectors for different operating conditions are investigated by means of computational fluid dynamics. The investigations are based on a collector design with horizontal tubes connected to a vertical 14 manifold channel. Three...... the highest efficiency, the optimal inlet flow rate was around 0.4-1 kg/min, the flow structures in the glass tubes were relatively uninfluenced by the inlet flow rate, Generally, the results showed only small variations in the efficiencies. This indicates that the collector design is well working for most...

  7. Solar collector wall with active curtain system; Lasikatteinen massiivienen aurinkokeraeaejaeseinae

    Energy Technology Data Exchange (ETDEWEB)

    Ojanen, T.; Heimonen, I. [VTT Building Technology, Espoo (Finland). Building Physics, Building Services and Fire Technology

    1998-12-01

    Integration of solar collector into the building envelope structure brings many advantages. The disadvantage of a passive solar collector wall is that its thermal performance can not be controlled, which may cause temporary overheating and low thermal efficiency of the collector. The thermal performance of the collector wall can be improved by using controllable, active collector systems. In this paper a solar collector wall with a controllable curtain between the transparent and absorption layers is investigated. The curtain is made of several low-emissivity foil layers, which ensures low radiation heat transfer through the curtain. The curtain decreases the heat losses out from the collector wall and it improves the U-value of the wall. The curtain is used when the solar radiation intensity to the wall is not high enough or when the wall needs protection against overheating during warm weather conditions. The materials and building components used in the collector wall, except those of the curtain, are ordinary in buildings. The transparent layer can be made by using normal glazing technology and the thermal storage layer can be made out of brick or similar material. The solar energy gains through the glazing can be utilised better than in passive systems, because the curtain provides the wall with high thermal resistance outside the solar radiation periods. The thermal performance of the collector wall was studied experimentally using a Hot-Box apparatus equipped with a solar lamp. Numerical simulations were carried out to study the yearly performance of the collector wall under real climate conditions. The objectives were to determine the thermal performance of the collector wall and to study how to optimise the use of solar radiation in this system. When the curtain with high thermal resistance is used actively, the temperature level of the thermal storage layer in the wall is relatively high also during dark periods and the heat losses out from the storage

  8. Dust in planetary nebulae

    International Nuclear Information System (INIS)

    Mathis, J.S.

    1978-01-01

    The author's review concentrates on theoretical aspects of dust in planetary nebulae (PN). He considers the questions: how much dust is there is PN; what is its composition; what effects does it have on the ionization structure, on the dynamics of the nebula. (Auth.)

  9. Toxicity of lunar dust

    NARCIS (Netherlands)

    Linnarsson, D.; Carpenter, J.; Fubini, B.; Gerde, P.; Loftus, D.; Prisk, K.; Staufer, U.; Tranfield, E.; van Westrenen, W.

    2012-01-01

    The formation, composition and physical properties of lunar dust are incompletely characterised with regard to human health. While the physical and chemical determinants of dust toxicity for materials such as asbestos, quartz, volcanic ashes and urban particulate matter have been the focus of

  10. Combustible dust tests

    Science.gov (United States)

    The sugar dust explosion in Georgia on February 7, 2008 killed 14 workers and injured many others (OSHA, 2009). As a consequence of this explosion, OSHA revised its Combustible Dust National Emphasis (NEP) program. The NEP targets 64 industries with more than 1,000 inspections and has found more tha...

  11. Respirable dust measured downwind during rock dust application.

    Science.gov (United States)

    Harris, M L; Organiscak, J; Klima, S; Perera, I E

    2017-05-01

    The Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health (NIOSH) conducted underground evaluations in an attempt to quantify respirable rock dust generation when using untreated rock dust and rock dust treated with an anticaking additive. Using personal dust monitors, these evaluations measured respirable rock dust levels arising from a flinger-type application of rock dust on rib and roof surfaces. Rock dust with a majority of the respirable component removed was also applied in NIOSH's Bruceton Experimental Mine using a bantam duster. The respirable dust measurements obtained downwind from both of these tests are presented and discussed. This testing did not measure miners' exposure to respirable coal mine dust under acceptable mining practices, but indicates the need for effective continuous administrative controls to be exercised when rock dusting to minimize the measured amount of rock dust in the sampling device.

  12. Lunar Dust Mitigation Screens

    Science.gov (United States)

    Knutson, Shawn; Holloway, Nancy

    With plans for the United States to return to the moon, and establish a sustainable human presence on the lunar surface many issues must be successfully overcome. Lunar dust is one of a number of issues with the potential to create a myriad of problems if not adequately addressed. Samples of dust brought back from Apollo missions show it to be soft, yet sharp and abrasive. The dust consists of a variety of morphologies including spherical, angular blocks, shards, and a number of irregular shapes. One of the main issues with lunar dust is its attraction to stick to anything it comes in contact with (i.e. astronauts, equipment, habitats, etc.). Ionized radiation from the sun strikes the moon's surface and creates an electrostatic charge on the dust. Further, the dust harbors van der Waals forces making it especially difficult to separate once it sticks to a surface. During the Apollo missions, it was discovered that trying to brush the lunar dust from spacesuits was not effective, and rubbing it caused degradation of the suit material. Further, when entering the lunar module after moonwalks, the astronauts noted that the dust was so prolific inside the cabin that they inhaled and ingested it, causing at least one of them, Harrison "Jack" Schmidt, to report irritation of the throat and lungs. It is speculated that the dust could also harm an astronaut's nervous and cardiovascular systems, especially during an extended stay. In addition to health issues, the dust can also cause problems by scouring reflective coatings off of thermal blankets, and roughening surfaces of windows and optics. Further, panels on solar cells and photovoltaics can also be compromised due to dust sticking on the surfaces. Lunar dust has the capacity to penetrate seals, interfere with connectors, as well as mechanisms on digging machines, all of which can lead to problems and failure. To address lunar dust issues, development of electrostatic screens to mitigate dust on sur-faces is currently

  13. Carbon Raman Spectroscopy of 36 Inter-Planetary Dust Particles

    Science.gov (United States)

    Busemann, H.; Nittler, L. R.; Davidson, J.; Franchi, I. A.; Messenger, S.; Nakamura-Messenger, K.; Palma, R. L.; Pepin, R. O.

    2009-01-01

    Carbon Raman spectroscopy is a useful tool to determine the degree of order of organic material (OM) in extra-terrestrial matter. As shown for meteoritic OM [e.g., 2], peak parameters of D and G bands are a measure of thermal alteration, causing graphitization (order), and amorphization, e.g. during protoplanetary irradiation, causing disorder. Th e most pristine interplanetary dust particles (IDPs) may come from comets. However, their exact provenance is unknown. IDP collection during Earth?s passage through comet Grigg-Skjellerup?s dust stream ("GSC" collectors) may increase the probability of collecting fresh IDPs from a known, cometary source. We used Raman spectroscopy to compare 21 GSC-IDPs with 15 IDPs collected at different periods, and found that the variation among GSC-IDPs is larger than among non-GSC IDPs, with the most primitive IDPs being mostly GSC-IDPs.

  14. Discrimination and quantification of contamination and implanted solar wind in Genesis collector shards using grazing incidence synchrotron x-ray techniques: Initial results

    International Nuclear Information System (INIS)

    Kitts, K.; Sutton, S.; Eng, P.; Ghose, S.; Burnett, D.

    2006-01-01

    Grazing incidence X-ray fluorescence is a non-destructive technique that can differentiate the embedded solar wind component from surface contamination and collector background in the Genesis shards. Initial solar Fe abundance in D30554 is 8 x 10 12 /cm 2 . Accurate knowledge of the composition of the Sun provides a baseline, which allows an understanding of how the solar system has evolved over time and how solar processes and solar wind mechanics behave. Unfortunately, the errors in photospheric abundances are too large for many planetary science problems and this hampers our understanding of these different processes. Analyses of solar wind implanted in meteorites or lunar soils have provided more precise data but alteration processes on these bodies may complicate such information. In response to this need for pristine solar wind samples, NASA developed and launched the Genesis Probe. Unfortunately, the probe smashed into the Utah desert shattering the 300 collector plates into 15,000+ pieces all of which are now coated in a both a fine terrestrial dust and Si and Ge powder from the disrupted collectors themselves. The solar wind penetration depth is 100-200 nm and the superposed contamination layers are typically 40-50 nm. Stringent cleaning regimes have the potential of removing the solar wind itself. The best solution is to have sufficient spatial resolution to separately analyze the surface contamination and penetrated solar wind. To that end, three Genesis collector array shards and their appropriate flight spares were characterized via grazing incidence x-ray fluorescence and x-ray reflectivity. The goals were (1) to evaluate the various cleaning methods used to eliminate contamination, (2) to identify the collector substrates most suited for this technique, (3) to determine whether the solar wind signature could be deconvolved from the collector background signature, and (4) to measure the relative abundances of Ca to Ge in the embedded solar wind.

  15. Flat solar collector an approach to its evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Sonino, T [Israel Atomic Energy Commission, Yavne. Soreq Nuclear Research Center

    1977-01-01

    The flat solar collector is the most widely used device for the utilization of solar energy, but its energetic and economic values are still debated. A preliminary energy and economic analysis is presented. The energy analysis indicates that the energy needed to produce one solar collector is equivalent to the electricity consumed by an electric water heater in roughly three months. The economic analysis indicates that the pay-back time for a solar collector varies from 5.5 to 7.7 yr. according to the discount rate. The economic analysis from a national point of view indicates that the use of solar collectors for domestic purposes could only reduce electricity consumption in Israel by 10%.

  16. Performance of jet impingement in unglazed air collectors

    Energy Technology Data Exchange (ETDEWEB)

    Belusko, M.; Saman, W.; Bruno, F. [Institute for Sustainable Systems and Technologies, University of South Australia, Mawson Lakes Boulevard, Mawson Lakes, SA 5095 (Australia)

    2008-05-15

    Jet impingement is effective at improving the heat transfer between air and a heated surface. Studies have shown that jet impingement can marginally improve the thermal efficiency of a glazed collector. However, little attention has been placed on applying jet impingement to an unglazed solar air collector. This paper presents a theoretical and experimental investigation identifying the performance characteristics of jet impingement. Overall, jet impingement was able to improve the thermal efficiency of the collector by 21%. An increase in the pressure loss was also measured but found to be small. The flow distribution of jets along the collector was the most significant factor in determining the efficiency. Increasing the hole spacing was found to improve the efficiency. (author)

  17. Integrated function nonimaging concentrating collector tubes for solar thermal energy

    Science.gov (United States)

    Winston, R.; Ogallagher, J. J.

    1982-09-01

    A substantial improvement in optical efficiency over contemporary external reflector evacuated tube collectors has been achieved by integrating the reflector surface into the outer glass envelope. Described are the design fabrication and test results for a prototype collector based on this concept. A comprehensive test program to measure performance and operational characteristics of a 2 sq m panel (45 tubes) has been completed. Efficiencies above 50% relative to beam at 200 C have been repeatedly demonstrated. Both the instantaneous and long term average performance of this totally stationary solar collector are comparable to those for tracking line focus parabolic troughs. The yield, reliability and stability of performance achieved have been excellent. Subcomponent assemblies and fabrication procedures have been used which are expected to be compatible with high volume production. The collector has a wide variety of applications in the 100 to 300 C range including industrial progress heat, air conditioning and Rankine engine operation.

  18. Bilinear reduced order approximate model of parabolic distributed solar collectors

    KAUST Repository

    Elmetennani, Shahrazed; Laleg-Kirati, Taous-Meriem

    2015-01-01

    This paper proposes a novel, low dimensional and accurate approximate model for the distributed parabolic solar collector, by means of a modified gaussian interpolation along the spatial domain. The proposed reduced model, taking the form of a low

  19. Investigation of a hybrid PVT air collector system

    Science.gov (United States)

    Haddad, S.; Touafek, K.; Mordjaoui, M.; Khelifa, A.; Tabet, I.

    2017-02-01

    The photovoltaic thermal hybrid (PVT) collectors, which simultaneously produce electricity and heat, are an alternative to photovoltaic modules and thermal collectors installed separately. Indeed, the heat extracted from the solar cell is used to heat water or air, thereby cooling the cell, and thus increasing its energy efficiency. This paper deals with a hybrid PVT air collector in which a new design has been proposed and tested. Its principle is based on the return of the preheating air to a second heating. The air thus passes twice under the solar cells before being evacuated to the outside of the collector (for space heating). The system is modular and expandable to cover large spaces to be heated. The experimental results of this novel design are presented and discussed under both normal and forced circulation. This technique of air return shows favorable results in terms of the quality of the heated air and electric power generation.

  20. Mathematical Modeling of Dual Intake Transparent Transpired Solar Collector

    Directory of Open Access Journals (Sweden)

    Thomas Semenou

    2015-01-01

    Full Text Available Nowadays, in several types of commercial or institutional buildings, a significant rise of transpired solar collectors used to preheat the fresh air of the building can be observed. Nevertheless, when the air mass flow rate is low, the collector efficiency collapses and a large amount of energy remains unused. This paper presents a simple yet effective mathematical model of a transparent transpired solar collector (TTC with dual intake in order to remove stagnation problems in the plenum and ensure a better thermal efficiency and more heat recovery. A thermal model and a pressure loss model were developed. Then, the combined model was validated with experimental data from the Solar Rating and Certification Corporation (SRCC. The results show that the collector efficiency can be up to 70% and even 80% regardless of operating conditions. The temperature gain is able to reach 20°K when the solar irradiation is high.

  1. [Naturalists, collectors and theoreticians of museology].

    Science.gov (United States)

    Arabas, Iwona

    2009-01-01

    The origins of the contemporary collectorship dates from times when the sameness of art and science was commonly accepted. In those days relics of the ancient past and natural individuals of newly discovered lands were presented at the same time. Cosmological character of the collections manifested the tenacity of recognition and representation of the surrounding reality. A great impact on completion of collections of curiosities in Europe had Netherlands, and in the basin of Baltic Sea a remarkable significance was gained by Hanseatic Gdańsk. Collections of Jakub Breyn, Jakub Klein and Gotfryd Reyger became famous then. In the same way were imported individuals for Anna Jabłonowska that composed one of the most interesting European collections. In course of time merging such a great multiplicity of collections was beyond collectors' power and museum pieces from collections of curiosities were parcelled out. It was a real beginning of specialistic museums. A role of museum for science results from its function of methodical organizing collections that can be used by research workers. However, although the aims of scientific and museum centres are different, they come together on the occasion of museum recognition works when museums' workers borrow essential knowledge and methods from resources of science, and scientists search for useful research materials in museum resources.

  2. Parabolic Trough Solar Collector Initial Trials

    Directory of Open Access Journals (Sweden)

    Ghalya Pikra

    2012-03-01

    Full Text Available This paper discusses initial trials of parabolic trough solar collector (PTSC in Bandung. PTSC model consists of concentrator, absorber and tracking system. Concentrator designs are made with 2m aperture width, 6m length and 0.75m focal distance. The design is equipped with an automatic tracking system which is driven using 12V and 24Watt DC motor with 0.0125rpm rotational speed. Absorber/receiver is designed with evacuated tube type, with 1 inch core diameter and tube made of AISI304 and coated with black oxide, the outer tube is borosilicate glass with a 70 mm diameter and 1.5 m length. Working fluid stored in single type of thermal storage tank, a single phase with 37.7 liter volume. PTSC model testing carried out for 2 hours and 10 minutes produces heat output and input of 11.5 kW and 0.64 kW respectively. 

  3. Performance evaluation for solar collectors in Taiwan

    International Nuclear Information System (INIS)

    Chang, T.P.

    2009-01-01

    In this paper, the global irradiation observed in Taiwan from 1990 to 1999 was used to estimate the optimal tilt angle for solar collectors. The observed data are resolved into diffusion and beam components, and transformed into instantaneous time frames using mathematical models. The energy gain on installing a single-axis tracked panel as compared to a traditional fixed panel is originally analyzed theoretically. In addition to the observation data, both types of radiation will be taken into account for comparison, i.e. both extraterrestrial radiation and global radiation predicted using empirical models. The results show that the yearly optimal angles for six selected stations are about 0.95 and 0.88 times their latitudes for extraterrestrial and predicted radiation, respectively. All of the observed irradiations are less than the predicted values for all times and stations, consequently resulting in a flatter tilt angle, with a few exceptions in summer. Since Taipei has the lowest clearness index, its yearly optimal angle calculated from observed data shows the greatest discrepancy when compared to its latitude. By employing a tracked panel, the yearly gains calculated from the observed data lie between 14.3% and 25.3%, which is significantly less than those from the extraterrestrial and predicted radiations

  4. Molecular design of flotation collectors: A recent progress.

    Science.gov (United States)

    Liu, Guangyi; Yang, Xianglin; Zhong, Hong

    2017-08-01

    The nature of froth flotation is to selectively hydrophobize valuable minerals by collector adsorption so that the hydrophobized mineral particles can attach air bubbles. In recent years, the increasing commercial production of refractory complex ores has been urgent to develop special collectors for enhancing flotation separation efficiency of valuable minerals from these ores. Molecular design methods offer an effective way for understanding the structure-property relationship of flotation collectors and developing new ones. The conditional stability constant (CSC), molecular mechanics (MM), quantitative structure-activity relationship (QSAR), and first-principle theory, especially density functional theory (DFT), have been adopted to build the criteria for designing flotation collectors. Azole-thiones, guanidines, acyl thioureas and thionocarbamates, amide-hydroxamates, and double minerophilic-group surfactants such as Gemini, dithiourea and dithionocarbamate molecules have been recently developed as high-performance collectors. To design hydrophobic groups, the hydrophilic-hydrophobic balance parameters have been extensively used as criteria. The replacement of aryl group with aliphatic group or CC single bond(s) with CC double bond(s), reduction of carbon numbers, introduction of oxygen atom(s) and addition of trisiloxane to the tail terminal have been proved to be useful approaches for adjusting the surface activity of collectors. The role of molecular design of collectors in practical flotation applications was also summarized. Based on the critical review, some comments and prospects for further research on molecular design of flotation collectors were also presented in the paper. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Means of increasing efficiency of CPC solar energy collector

    Science.gov (United States)

    Chao, B.T.; Rabl, A.

    1975-06-27

    A device is provided for improving the thermal efficiency of a cylindrical radiant energy collector. A channel is placed next to and in close proximity to the nonreflective side of an energy reflective wall of a cylindrical collector. A coolant is piped through the channel and removes a portion of the nonreflective energy incident on the wall which is absorbed by the wall. The energy transferred to the coolant may be utilized in a useful manner.

  6. Proceedings of the solar thermal concentrating collector technology symposium

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, B.P.; Kreith, F. (eds.)

    1978-08-01

    The purpose of the symposium was to review the current status of the concentrating collector technology, to disseminate the information gained from experience in operating solar systems, and to highlight the significant areas of technology development that must be vigorously pursued to foster early commercialization of concentrating solar collectors. Separate abstracts were prepared for thirteen invited papers and working group summaries. Two papers were previously abstracted for EDB.

  7. Comparison of thermal solar collector technologies and their applications

    OpenAIRE

    Alarcón Villamil, Alexander; Hortúa, Jairo Eduardo; López, Andrea

    2013-01-01

    This paper presents the operation of different thermal solar collector technologies and their main characteristics. It starts by providing a brief description of the importance of using solar collectors as an alternative to reduce the environmental impact caused by the production of non-renewable sources like coal and oil. Subsequently, it focuses on each solar concentrator technology and finishes with a theoretical analysis hub application in different industrial processes. En este artícu...

  8. Transient analysis of the double pass photovoltaic thermal solar collector

    International Nuclear Information System (INIS)

    Alfegi, Ebrahim M.; Sopian, Kamaruzzaman; Abakr, Yousif A.

    2006-01-01

    A mathematical model of a double pass photovoltaic thermal (PV/T) solar collector is reported in this work. It is composed of five couple unsteady nonlinear partial differential equations which are solved by using Gear implicit numerical scheme. That model was validated against experimental data and was found to accurately predict the temperature of the circulated air as well as the temperature distribution of every static elements in a two-pass PV/T solar collector.(Author)

  9. Interaction of regulation and innovation: Solar air heating collectors

    OpenAIRE

    Kramer, K.

    2012-01-01

    Solar Air Heating Collectors have still a very small share of 0.8% of the nominal installed capacity in the solar heating and cooling market (151.7 GWth) [1]. Although constituting a niche market, the potential of those kind of collectors to provide heat for industrial processes, processing food, room heating, air preheating, drying processes or air conditioning could be significant. However, the technical potentials of the various technological solutions are not easy to compare. Such a compa...

  10. Ground collectors for heat pumps; Grondcollectoren voor warmtepompen

    Energy Technology Data Exchange (ETDEWEB)

    Van Krevel, A. [Techneco, Leidschendam (Netherlands)

    1999-10-01

    The dimensioning and cost optimisation of a closed vertical ground collector system has been studied. The so-called Earth Energy Designer (EED) computer software, specially developed for the calculations involved in such systems, proved to be a particularly useful tool. The most significant findings from the first part of the study, 'Heat extraction from the ground', are presented and some common misconceptions about ground collector systems are clarified. 2 refs.

  11. Quantifying Anthropogenic Dust Emissions

    Science.gov (United States)

    Webb, Nicholas P.; Pierre, Caroline

    2018-02-01

    Anthropogenic land use and land cover change, including local environmental disturbances, moderate rates of wind-driven soil erosion and dust emission. These human-dust cycle interactions impact ecosystems and agricultural production, air quality, human health, biogeochemical cycles, and climate. While the impacts of land use activities and land management on aeolian processes can be profound, the interactions are often complex and assessments of anthropogenic dust loads at all scales remain highly uncertain. Here, we critically review the drivers of anthropogenic dust emission and current evaluation approaches. We then identify and describe opportunities to: (1) develop new conceptual frameworks and interdisciplinary approaches that draw on ecological state-and-transition models to improve the accuracy and relevance of assessments of anthropogenic dust emissions; (2) improve model fidelity and capacity for change detection to quantify anthropogenic impacts on aeolian processes; and (3) enhance field research and monitoring networks to support dust model applications to evaluate the impacts of disturbance processes on local to global-scale wind erosion and dust emissions.

  12. An improved dynamic test method for solar collectors

    DEFF Research Database (Denmark)

    Kong, Weiqiang; Wang, Zhifeng; Fan, Jianhua

    2012-01-01

    A comprehensive improvement of the mathematical model for the so called transfer function method is presented in this study. This improved transfer function method can estimate the traditional solar collector parameters such as zero loss coefficient and heat loss coefficient. Two new collector...... parameters t and mfCf are obtained. t is a time scale parameter which can indicate the heat transfer ability of the solar collector. mfCf can be used to calculate the fluid volume content in the solar collector or to validate the regression process by comparing it to the physical fluid volume content...... for the second-order differential term with 6–9min as the best averaging time interval. The measured and predicted collector power output of the solar collector are compared during a test of 13days continuously both for the ITF method and the QDT method. The maximum and averaging error is 53.87W/m2 and 5.22W/m2...

  13. Dual curvature acoustically damped concentrating collector. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.A.; Rausch, R.A.

    1980-05-01

    A development program was conducted to investigate the design and performance parameters of a novel, dual curvature, concentrating solar collector. The reflector of the solar collector is achieved with a stretched-film reflective surface that approximates a hyperbolic paraboloid and is capable of line-focusing at concentration ratios ranging from 10 to 20X. A prototype collector was designed based on analytical and experimental component trade-off activities as well as economic analyses of solar thermal heating and cooling systems incorporating this type of collector. A prototype collector incorporating six 0.66 x 1.22 m (2 x 4 ft) was fabricated and subjected to a limited thermal efficiency test program. A peak efficiency of 36% at 121/sup 0/C (250/sup 0/F) was achieved based upon the gross aperture area. Commercialization activities were conducted, including estimated production costs of $134.44/m/sup 2/ ($12.49/ft/sup 2/) for the collector assembly (including a local suntracker and controls) and $24.33/m/sup 2/ ($2.26/ft/sup 2/) for the reflector subassembly.

  14. EFFICIENCY AND LIFETIME OF SOLAR COLLECTORS FOR SOLAR HEATING PLANTS

    DEFF Research Database (Denmark)

    The 12.5 m² flat plate solar collector HT, today marketed by Arcon Solvarme A/S, has been used in solar heating plants in Scandinavia since 1983. The collector is designed to operate in a temperature interval between 40°C and 90°C. The efficiency of the collector has been strongly improved since...... it was introduced on the market. The paper will present the increase of the efficiency of the collector due to technical improvements since 1983. Further, measurements from the spring of 2009 of the efficiency of two HT collectors, which have been in operation in the solar heating plant Ottrupgaard, Skørping......, Denmark since 1994 with a constant high flow rate and in the solar heating plant Marstal, Denmark since 1996 with a variable flow rate, will be presented. The efficiencies will be compared to the efficiencies of the collectors when they were first installed in the solar heating plants. The measurements...

  15. EFFICIENCY AND LIFETIME OF SOLAR COLLECTORS FOR SOLAR HEATING PLANTS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Chen, Ziqian; Furbo, Simon

    2009-01-01

    The 12.5 m² flat plate solar collector HT, today marketed by Arcon Solvarme A/S, has been used in solar heating plants in Scandinavia since 1983. The collector is designed to operate in a temperature interval between 40°C and 90°C. The efficiency of the collector has been strongly improved since...... it was introduced on the market. The paper will present the increase of the efficiency of the collector due to technical improvements since 1983. Further, measurements from the spring of 2009 of the efficiency of two HT collectors, which have been in operation in the solar heating plant Ottrupgaard, Skørping......, Denmark since 1994 with a constant high flow rate and in the solar heating plant Marstal, Denmark since 1996 with a variable flow rate, will be presented. The efficiencies will be compared to the efficiencies of the collectors when they were first installed in the solar heating plants. The measurements...

  16. Energy Analysis of Solar Collector With perforated Absorber Plate

    Directory of Open Access Journals (Sweden)

    Ammar A. Farhan

    2017-09-01

    Full Text Available The thermal performance of three solar collectors with 3, 6 mm and without perforation absorber plate was assessed experimentally. The experimental tests were implemented in Baghdad during the January and February 2017. Five values of airflow rates range between 0.01 – 0.1 m3/s were used through the test with a constant airflow rate during the test day. The variation of the following parameters air temperature difference, useful energy, absorber plate temperature, and collector efficiency was recorded every 15 minutes. The experimental data reports that the increases the number of absorber plate perforations with a small diameter is more efficient rather than increasing the hole diameter of the absorber plate with decreasing the perforation numbers. Maximum air temperature difference throughout the solar collector with 3, 6 mm perforations and without perforations are 17, 15, and 12 oC, respectively. Also, it can be concluded that the energy gained from the solar collector with 3 mm perforation absorber plate is 28.2 % more than the energy gained from solar collector without holes per day for 0.1 m3/s airflow rate. The maximum values of the thermal performance curves are 0.67, 0.64, and 0.56 for the solar collector with 3, 6 mm, and without perforations, respectively.

  17. Spirit Feels Dust Gust

    Science.gov (United States)

    2007-01-01

    On sol 1149 (March 28, 2007) of its mission, NASA's Mars Exploration Rover Spirit caught a wind gust with its navigation camera. A series of navigation camera images were strung together to create this movie. The front of the gust is observable because it was strong enough to lift up dust. From assessing the trajectory of this gust, the atmospheric science team concludes that it is possible that it passed over the rover. There was, however, no noticeable increase in power associated with this gust. In the past, dust devils and gusts have wiped the solar panels of dust, making it easier for the solar panels to absorb sunlight.

  18. Standarized performance tests of collectors of solar thermal energy: A steel flat-plate collector with two transparent covers and a proprietary coating

    Science.gov (United States)

    1976-01-01

    Basic test results of a flat-plate solar collector whose performance was determined in the NASA-Lewis solar simulator are given. The collector was tested over ranges of inlet temperature and flux level.

  19. Coloured solar collectors. Phase II : from laboratory samples to collector prototypes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, A; Roecker, Ch; Chambrier, E de; Munari Probst, M

    2007-07-01

    This illustrated final report for the Swiss Federal Office of Energy (SFOE) deals with the second phase of a project concerning the architectural integration of glazed solar collectors into the facades of buildings for heat production. The factors that limit the integration of photovoltaic panels in facades are discussed. The authors state that, for a convincing demonstration, sufficiently large samples and high quality levels are needed. The sol-gel deposition of the multi-layered coatings on A4-sized glass panes demonstrated in the laboratory by EPFL-LESO are discussed. The coatings produced exhibit a coloured reflection in combination with a high solar transmittance, a homogenous appearance, and are free of visible defects. Film hardening by UV exposure is discussed: This should result in the speeding up of the sol-gel process and thus save energy, thereby significantly reducing costs. Collaboration with industry is discussed in which full-scale glass panes are to be coated with novel multiple layers. The novel glazing is to be integrated into first prototype collectors. The manufacturing and test processes for the prototypes manufactured are discussed in detail.

  20. Analysis of collector-emitter offset voltage of InGaP/GaAs composite collector double heterojunction bipolar transistor

    Science.gov (United States)

    Lew, K. L.; Yoon, S. F.

    2002-04-01

    The Ebers-Moll-like terminal current expressions of a composite collector double heterojunction bipolar transistor (DHBT), which takes the recombination effect into account, have been formulated and an expression for collector-emitter offset voltage [VCE(offset)] has been derived. Factors affecting the VCE(offset) of a composite collector DHBT are investigated and good agreement between the calculated and reported experimental results is shown. Analytical results showed that the transmission coefficient of the base-collector (B-C) junction does not have a considerable effect on the VCE(offset), provided that the B-C junction is of good quality. Thus, despite its asymmetric structure, the VCE(offset) of an optimally designed composite collector DHBT could be as low as that of a conventional DHBT. Hence a composite collector DHBT with low saturation voltage and negligible VCE(offset) is possible if the two conditions: (i) good quality B-C junction, (ii) base transport factor, α≈1, are fulfilled.

  1. Advanced Hybrid Particulate Collector Project Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.J.

    1995-11-01

    As the consumption of energy increases, its impact on ambient air quality has become a significant concern. Recent studies indicate that fine particles from coal combustion cause health problems as well as atmospheric visibility impairment. These problems are further compounded by the concentration of hazardous trace elements such as mercury, cadmium, selenium, and arsenic in fine particles. Therefore, a current need exists to develop superior, but economical, methods to control emissions of fine particles. Since most of the toxic metals present in coal will be in particulate form, a high level of fine- particle collection appears to be the best method of overall air toxics control. However, over 50% of mercury and a portion of selenium emissions are in vapor form and cannot be collected in particulate control devices. Therefore, this project will focus on developing technology not only to provide ultrahigh collection efficiency of particulate air toxic emissions, but also to capture vapor- phase trace metals such as mercury and selenium. Currently, the primary state-of-the-art technologies for particulate control are fabric filters (baghouses) and electrostatic precipitators (ESPs). However, they both have limitations that prevent them from achieving ultrahigh collection of fine particulate matter and vapor-phase trace metals. The objective of this project is to develop a highly reliable advanced hybrid particulate collector (AHPC) that can provide > 99.99 % particulate collection efficiency for all particle sizes between 0.01 and 50 14m, is applicable for use with all U.S. coals, and is cost-0443competitive with existing technologies. Phase I of the project is organized into three tasks: Task I - Project Management, Reporting, and Subcontract Consulting Task 2 - Modeling, Design, and Construction of 200-acfm AHPC Model Task 3 - Experimental Testing and Subcontract Consulting

  2. Solar energy collector/storage system

    Energy Technology Data Exchange (ETDEWEB)

    Bettis, J.R.; Clearman, F.R.

    1983-05-24

    A solar energy collector/storage system which includes an insulated container having working fluid inlets and outlets and an opening, a light-transmitting member positioned over the opening, and a heat-absorbing member which is centrally situated, is supported in the container, and is made of a mixture of gypsum , lampblack, and water. A light-reflecting liner made of corrugated metal foil preferably is attached to the internal surface of the container. The opening of the container is positioned in optical alignment with a source of solar energy. A light-reflecting cover optionally can be hingedly attached to the container, and can be positioned such as to reflect solar energy rays into the container. The system is adaptable for use with a working gas (e.g., air) and/or a working liquid (e.g., water) in separated flows which absorb heat from the heat-absorbing member, and which are useable per se or in an associated storage and/or circulatory system that is not part of this invention. The heatabsorbing mixture can also contain glass fibers. The heatabsorbing member is of such great load-bearing strength that it can also be used simultaneously as a structural member, e.g., a wall or ceiling of a room; and, thereby, the system can be used to heat a room, if a window of the room is the light-transmitting member and is facing the sun, and if the heat-absorbing member is a wall and/or the ceiling of the room and receives solar energy through the window.

  3. CISBAT 2007 - Solar collectors (heat and electricity)

    International Nuclear Information System (INIS)

    2007-01-01

    This is the third part of the proceedings of the 2007 CISBAT conference on Renewables in a changing climate, held in Lausanne, Switzerland. On the subject of Building and urban integration of renewables the following oral contributions are summarised: 'Facade integration of solar thermal collectors: present and future', 'Long term experiences with a versatile PV in roof system', 'Development of a design and performance prediction tool for the ground source heat pump and underground thermal storage system', 'Hygrothermal performance of earth-to-air heat exchanger: long-term data evaluation and short-term simulation' as well as 'The real cost of heating your home: a comparative assessment of home energy systems with external costs'. Poster-sessions on the subject include 'Central solar heating plants with seasonal heat storage', 'Analysis of forced convection for evaporative air flow and heat transfer in PV cooling channels', 'Renewable energy technology in Mali: constraints and options for a sustainable development', 'Effect of duct width in ducted photovoltaic facades', 'Design and actual measurement of a ground source heat pump system using steel foundation piles as ground heat exchangers', 'Development of an integrated water-water heat pump unit for low energy house and its application', 'PV effect in multilayer cells and blending of fullerene/poly (3-hexylthiophene) and phthalocyanine having NIR charge transfer absorption band', 'CdTe photovoltaic systems - an alternative energetic', 'Integration of renewable energy sources in a town, examples in Grenoble', 'A prospective analysis method for the conception of solar integration solutions in buildings' and 'Energy and aesthetic improvements for building integration of cost effective solar energy systems'. Further groups of presentations at the conference are reported on in separate database records. An index of authors completes the proceedings

  4. Sampling efficiency of the Moore egg collector

    Science.gov (United States)

    Worthington, Thomas A.; Brewer, Shannon K.; Grabowski, Timothy B.; Mueller, Julia

    2013-01-01

    Quantitative studies focusing on the collection of semibuoyant fish eggs, which are associated with a pelagic broadcast-spawning reproductive strategy, are often conducted to evaluate reproductive success. Many of the fishes in this reproductive guild have suffered significant reductions in range and abundance. However, the efficiency of the sampling gear used to evaluate reproduction is often unknown and renders interpretation of the data from these studies difficult. Our objective was to assess the efficiency of a modified Moore egg collector (MEC) using field and laboratory trials. Gear efficiency was assessed by releasing a known quantity of gellan beads with a specific gravity similar to that of eggs from representatives of this reproductive guild (e.g., the Arkansas River Shiner Notropis girardi) into an outdoor flume and recording recaptures. We also used field trials to determine how discharge and release location influenced gear efficiency given current methodological approaches. The flume trials indicated that gear efficiency ranged between 0.0% and 9.5% (n = 57) in a simple 1.83-m-wide channel and was positively related to discharge. Efficiency in the field trials was lower, ranging between 0.0% and 3.6%, and was negatively related to bead release distance from the MEC and discharge. The flume trials indicated that the gellan beads were not distributed uniformly across the channel, although aggregation was reduced at higher discharges. This clustering of passively drifting particles should be considered when selecting placement sites for an MEC; further, the use of multiple devices may be warranted in channels with multiple areas of concentrated flow.

  5. Effect of openings collectors and solar irradiance on the thermal efficiency of flat plate-finned collector for indirect-type passive solar dryer

    Science.gov (United States)

    Batubara, Fatimah; Dina, Sari Farah; Klaudia Kathryn Y., M.; Turmuzi, M.; Siregar, Fitri; Panjaitan, Nora

    2017-06-01

    Research on the effect of openings solar collector and solar irradiance to thermal efficiency has been done. Solar collector by flat plate-finned type consists of 3 ply insulator namely wood, Styrofoam and Rockwool with thickness respectively are 10 mm, 25 mm and 50 mm. Absorber plate made of aluminum sheet with thickness of 0.30 mm, painted by black-doff. Installation of 19 units fins (length x height x thickness: 1000x20x10 mm) on the collector will increase surface area of absorber so it can receive much more solar energy. The solar collector cover is made of glass (thickness of 5 mm). During the research, the solar irradiance and temperature of collector are measured and recorded every five minutes. Temperature measurement performed on the surface of the absorber plate, inside of collector, surface cover and the outer side insulator (plywood). This data is used to calculate the heat loss due to conduction, convection and radiation on the collector. Openings of collectors vary as follows: 100%, 75%, 15% and 0% (total enclosed). The data collecting was conducted from 09.00 am to 17.00 pm and triplicates. The collector thermal efficiency calculated based on the ratio of the amount of heat received to the solar irradiance absorbed. The results show that each of openings solar collector has different solar irradiance (because it was done on a different day) which is in units of W/m2: 390 (100% open), 376 (75% open), 429 (15% open), and 359 (totally enclosed). The highest thermal efficiency is in openings variation of 15% opened. These results indicate that the efficiency of the collector is influenced by the solar irradiance received by the collector and the temperature on the collector plate. The highest thermal efficiency is in variation of openings 15%. These indicate that the efficiency of the collector was influenced by solar irradiance received by the collector and openings of the collector plate.

  6. Galactic dust and extinction

    International Nuclear Information System (INIS)

    Lyngaa, G.

    1979-01-01

    The ratio R between visual extinction and colour excess, is slightly larger than 3 and does not vary much throughout our part of the Galaxy. The distribution of dust in the galactic plane shows, on the large scale, a gradient with higher colour excesses towards l=50 0 than towards l=230 0 . On the smaller scale, much of the dust responsible for extinction is situated in clouds which tend to group together. The correlation between positions of interstellar dust clouds and positions of spiral tracers seems rather poor in our Galaxy. However, concentrated dark clouds as well as extended regions of dust show an inclined distribution similar to the Gould belt of bright stars. (Auth.)

  7. Radioisotope dust pollution monitor

    International Nuclear Information System (INIS)

    Szepke, R.; Harasimczuk, J.; Dobrowiecki, J.

    1990-01-01

    Measuring principles and specification of two dust monitors: station-type AMIZ and portable-type PIK-10 for ambient air pollution are presented. The first one, a fully automatic instrument is destined for permanent monitoring of air pollution in preset sampling time from .25 to 24 hours. The second one was developed as a portable working model. Both instruments display their results in digital form in dust concentration units. (author)

  8. Coal dust symposium

    Energy Technology Data Exchange (ETDEWEB)

    1981-03-01

    This paper gives a report of the paper presented at the symposium held in Hanover on 9 and 10 February 1981. The topics include: the behaviour of dust and coal dust on combustion and explosion; a report on the accidents which occurred at the Laegerdorf cement works' coal crushing and drying plant; current safety requirements at coal crushing and drying plant; and coal crushing and drying. Four papers are individually abstracted. (In German)

  9. Dust devil generation

    International Nuclear Information System (INIS)

    G Onishchenko, O; A Pokhotelov, O; Horton, W; Stenflo, L

    2014-01-01

    The equations describing axi-symmetric nonlinear internal gravity waves in an unstable atmosphere are derived. A hydrodynamic model of a dust devil generation mechanism in such an atmosphere is investigated. It is shown that in an unstably stratified atmosphere the convective plumes with poloidal motion can grow exponentially. Furthermore, it is demonstrated that these convective plumes in an atmosphere with weak large scale toroidal motion are unstable with respect to three-dimensional dust devil generation. (papers)

  10. Standardized performance tests of collectors of solar thermal energy-a flat-plate collector with a single-tube serpentine flow distribution

    Science.gov (United States)

    Johnson, S.

    1976-01-01

    This preliminary data report gives basic test results of a flat-plate solar collector whose performance was determined in the NASA-Lewis solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and coolant flow rates. Collector efficienty is correlated in terms of inlet temperature and flux level.

  11. Performance of cylindrical plastic solar collectors for air heating

    International Nuclear Information System (INIS)

    Abdullah, A.S.; Bassiouny, M.K.

    2014-01-01

    Highlights: • The study including the combined convective and radiative heat transfer analysis. • The solar collector is manufactured from LDPE films acting as a black absorber. • Comparisons between the experimental data and the theoretical methods have been made. • The thermal efficiency increases with decreasing the major axes of elliptic shape. • The Nusselt number between the absorber and the heated air is determined. - Abstract: A theoretical and experimental study including the combined convective and radiative heat transfer analysis of a flexible cylindrical type solar air-heater for agriculture crops dehydration as well as heating processes is presented. The solar collector is manufactured from LDPE films acting as a black absorber with a back insulation and double transparent covers sealed together along its edges. The collector is to be blown with a flow of pressurized air. The experiments are carried out with solar collectors of circular shapes having 0.5 m diameter and solar collectors of elliptic shapes having 0.55 m and 0.65 m major axis. Energy balance of the cover, absorber and air yield three simultaneous quadratic algebraic equations in the three unknowns namely, cover, absorber and outlet air temperatures. A computer program is written for calculating the outlet temperature using the Newton–Raphson method and the collector thermal efficiency in terms of its diameter, length, mass flow rate, inlet temperature and solar insolation. Moreover the Nusselt number between the absorber and the heated air is determined experimentally in relation with the Reynolds number. Comparisons between the experimental data and the theoretical methods for the collector efficiency demonstrate a good agreement. In addition of this, the present experimental results of Nusselt number are correlated and compared with a correlation of another authors

  12. Performance of non-conventional solar collectors in local market of Nawabshah

    International Nuclear Information System (INIS)

    Memon, M.; Tanwani, N.K.; Memon, A.H.

    1998-01-01

    This paper presents experimental studies concerning the performance of solar collectors using sand-bed as absorbing surface and a collector. These collectors were designed, manufactured locally and tested in meteorological conditions of Nawabshah, Sindh, Pakistan. The ordinary tap water was used as working fluid and tests were carried out in open space during day time. The effect of collector area and tubing diameter on collector performance was investigated. For each test run ambient, inlet and outlet water temperature together with flow rate of collector fluid was recorded. Two collectors connected in series showed an increase of about 20 deg. C in outlet temperature of water. Thus an average increase of 15 deg. C in the temperature was observed for each collector. The temperature was raised to 90 deg. C using the concentrator in combination with the two non-conventional flat collectors. (author)

  13. Optimum tilt angle and orientation for solar collectors in Syria

    International Nuclear Information System (INIS)

    Skeiker, Kamal

    2009-01-01

    One of the important parameters that affect the performance of a solar collector is its tilt angle with the horizon. This is because of the variation of tilt angle changes the amount of solar radiation reaching the collector surface. A mathematical model was used for estimating the solar radiation on a tilted surface, and to determine the optimum tilt angle and orientation (surface azimuth angle) for the solar collector in the main Syrian zones, on a daily basis, as well as for a specific period. The optimum angle was computed by searching for the values for which the radiation on the collector surface is a maximum for a particular day or a specific period. The results reveal that changing the tilt angle 12 times in a year (i.e. using the monthly optimum tilt angle) maintains approximately the total amount of solar radiation near the maximum value that is found by changing the tilt angle daily to its optimum value. This achieves a yearly gain in solar radiation of approximately 30% more than the case of a solar collector fixed on a horizontal surface.

  14. Commissioning a Megawatt-class Gyrotron with Collector Potential Depression

    Science.gov (United States)

    Lohr, J.; Cengher, M.; Gorelov, Y. A.; Ponce, D.; Prater, R.

    2013-10-01

    A 110 GHz depressed collector gyrotron has been installed on the DIII-D tokamak. The commissioning process rapidly achieved operation at full parameters, 45 A and 94 kV total voltage, with 29 kV depression. Although short pulse, 2 ms, factory testing demonstrated 1.2 MW at 41% electrical efficiency, long pulse testing at DIII-D achieved only 33% efficiency at full power parameters, for pulse lengths up to 10 s. Maximum generated power was ~950 kW, considerably below the 1.2 MW target. During attempts to increase the power at 5 s pulse length, it was noted that the collector cooling water was boiling. This led to the discovery that 14 of the 160 cooling channels in the collector had been blocked by braze material during manufacture of the tube. The locations of blocked channels were identified using infrared imaging of the outside of the collector during rapid changes in the cooling water temperature. Despite these difficulties, the rf beam itself was of very high quality and the stray rf found calorimetrically in the Matching Optics Unit, which couples the Gaussian rf beam to the waveguide, was only 2% of the generated power, about half that of our previous best quality high power beam. Details of the power measurements and collector observations will be presented. Work supported by the US DOE under DE-FC02-04ER54698.

  15. Performance of direct absorption solar collector with nanofluid mixture

    International Nuclear Information System (INIS)

    Turkyilmazoglu, Mustafa

    2016-01-01

    Highlights: • Neat approximations for temperature and solar collector efficiency are presented. • The non-adiabatic and isothermal base mechanisms optimize the surface absorption. • Heat transferring material at the bottom panel enhances the thermal efficiency. • Isothermal base panel leads to maximum thermal efficiency of the solar receiver. - Abstract: The enhancement of performance by increasing the thermal efficiency of a direct absorption solar collector based on an alumina–water nanofluid is the prime target of the present research. The base panel of the collector channel is subject to either a non adiabatic or an isothermal wall condition both of which introduce two new physical parameters. Analytical solutions for the temperature field are worked out in both cases for a two dimensional steady-state model recently outlined in the literature. The desired increase in the temperature of the heat transferring nanofluid is achieved either by slightly rising the heat transfer coefficient of the bottom panel coating or by prescribing a bottom surface temperature. As a consequence of the increase in the final outlet mean temperature, the solar collector thermal efficiency is found to be enhanced via increasing the new physical parameters as compared to the traditional adiabatic wall case. For instance, 85.63% thermal efficiency of solar collector is achievable for non adiabatic bottom panel by adding suspended aluminum nanoparticles into the pure water. Even better than this, considering isothermal base panels, 100% efficiency is attained more rapidly with lesser base temperatures in the presence of higher nanoparticle volume fractions.

  16. Integrated collector storage solar water heater: Temperature stratification

    International Nuclear Information System (INIS)

    Garnier, C.; Currie, J.; Muneer, T.

    2009-01-01

    An analysis of the temperature stratification inside an Integrated Collector Storage Solar Water Heater (ICS-SWH) was carried out. The system takes the form of a rectangular-shaped box incorporating the solar collector and storage tank into a single unit and was optimised for simulation in Scottish weather conditions. A 3-month experimental study on the ICS-SWH was undertaken in order to provide empirical data for comparison with the computed results. Using a previously developed macro model; a number of improvements were made. The initial macro model was able to generate corresponding water bulk temperature in the collector with a given hourly incident solar radiation, ambient temperature and inlet water temperature and therefore able to predict ICS-SWH performance. The new model was able to compute the bulk water temperature variation in different SWH collectors for a given aspect ratio and the water temperature along the height of the collector (temperature stratification). Computed longitudinal temperature stratification results obtained were found to be in close agreement with the experimental data.

  17. Performance analysis of photovoltaic thermal (PVT) water collectors

    International Nuclear Information System (INIS)

    Fudholi, Ahmad; Sopian, Kamaruzzaman; Yazdi, Mohammad H.; Ruslan, Mohd Hafidz; Ibrahim, Adnan; Kazem, Hussein A.

    2014-01-01

    Highlights: • Performances analysis of PVT collector based on energy efficiencies. • New absorber designs of PVT collectors were presented. • Comparison present study with other absorber collector designs was presented. • High efficiencies were obtained for spiral flow absorber. - Abstract: The electrical and thermal performances of photovoltaic thermal (PVT) water collectors were determined under 500–800 W/m 2 solar radiation levels. At each solar radiation level, mass flow rates ranging from 0.011 kg/s to 0.041 kg/s were introduced. The PVT collectors were tested with respect to PV efficiency, thermal efficiency, and a combination of both (PVT efficiency). The results show that the spiral flow absorber exhibited the highest performance at a solar radiation level of 800 W/m 2 and mass flow rate of 0.041 kg/s. This absorber produced a PVT efficiency of 68.4%, a PV efficiency of 13.8%, and a thermal efficiency of 54.6%. It also produced a primary-energy saving efficiency ranging from 79% to 91% at a mass flow rate of 0.011–0.041 kg/s

  18. Effect of the collector tube profile on Pitot pump performances

    Science.gov (United States)

    Komaki, K.; Kanemoto, T.; Sagara, K.; Umekage, T.

    2013-12-01

    The pitot pump is composed of the rotating casing with the impeller channel and the pitot tube type collector as the discharge line. The radial impeller feeds water to the rotating casing. The water rotating together with the casing is caught by the stationary pitot tube type collector, and then discharges to the outside. This type pump, as the extra high head pump, is provided mainly for boiler feed systems, and has been designed by trial and error. To optimize the pump profiles, it is desirable to investigate not only performances but also internal flow conditions. This paper discusses experimentally and numerically the relation between the pump performances and the flow conditions in the rotating casing. The moderately larger dimensions of the collector make the pump head and the discharge high with the higher hydraulic efficiency. The flow in the casing is almost the forced vortex type whose velocity is in proportion to the radius but the core velocity is affected with the drag force of the stationary collector. Based upon the above results, the profile of the pitot tube type collector was optimized with the numerical simulation.

  19. Effect of the collector tube profile on Pitot pump performances

    International Nuclear Information System (INIS)

    Komaki, K; Sagara, K; Kanemoto, T; Umekage, T

    2013-01-01

    The pitot pump is composed of the rotating casing with the impeller channel and the pitot tube type collector as the discharge line. The radial impeller feeds water to the rotating casing. The water rotating together with the casing is caught by the stationary pitot tube type collector, and then discharges to the outside. This type pump, as the extra high head pump, is provided mainly for boiler feed systems, and has been designed by trial and error. To optimize the pump profiles, it is desirable to investigate not only performances but also internal flow conditions. This paper discusses experimentally and numerically the relation between the pump performances and the flow conditions in the rotating casing. The moderately larger dimensions of the collector make the pump head and the discharge high with the higher hydraulic efficiency. The flow in the casing is almost the forced vortex type whose velocity is in proportion to the radius but the core velocity is affected with the drag force of the stationary collector. Based upon the above results, the profile of the pitot tube type collector was optimized with the numerical simulation

  20. Optimization of the functional domain of flat plate collectors

    Science.gov (United States)

    Ritoux, G.; Irigaray, J.-L.

    1981-12-01

    The variations of the extracted heat flux as function of the temperature of the heat transfer fluid in black and selective surface solar collectors are examined. The heat flux is calculated based on the difference of the initial to the stage of thermal equilibrium of the fluid. A nonlinear system of equations is developed and solved by a fast, iterative method to obtain the equilibrium temperatures. It is found that more flux can be extracted from the solar heat by a collector with only one glass cover than with more than one cover. The captured flux is proportional to the coefficient of transmission of the glass coverings, to the coefficient of absorption of the collector, and to the incident flux. Black painted surfaces were more absorbent than selective surfaces, and highest collection efficiencies were displayed by low temperature collectors. Charts of effective uses of the respective types of collectors for heating swimming pools, hot water, home heat, and for refrigeration and air-conditioning are provided.

  1. Wide bandgap collector III-V double heterojunction bipolar transistors

    International Nuclear Information System (INIS)

    Flitcroft, R.M.

    2000-10-01

    This thesis is devoted to the study and development of Heterojunction Bipolar Transistors (HBTs) designed for high voltage operation. The work concentrates on the use of wide bandgap III-V semiconductor materials as the collector material and their associated properties influencing breakdown, such as impact ionisation coefficients. The work deals with issues related to incorporating a wide bandgap collector into double heterojunction structures such as conduction band discontinuities at the base-collector junction and results are presented which detail, a number of methods designed to eliminate the effects of such discontinuities. In particular the use of AlGaAs as the base material has been successful in eliminating the conduction band spike at this interface. A method of electrically injecting electrons into the collector has been employed to investigate impact ionisation in GaAs, GaInP and AlInP which has used the intrinsic gain of the devices to extract impact ionisation coefficients over a range of electric fields beyond the scope of conventional optical injection techniques. This data has enabled the study of ''dead space'' effects in HBT collectors and have been used to develop an analytical model of impact ionisation which has been incorporated into an existing Ebers-Moll HBT simulator. This simulator has been shown to accurately reproduce current-voltage characteristics in both the devices used in this work and for external clients. (author)

  2. Fractal dust grains in plasma

    International Nuclear Information System (INIS)

    Huang, F.; Peng, R. D.; Liu, Y. H.; Chen, Z. Y.; Ye, M. F.; Wang, L.

    2012-01-01

    Fractal dust grains of different shapes are observed in a radially confined magnetized radio frequency plasma. The fractal dimensions of the dust structures in two-dimensional (2D) horizontal dust layers are calculated, and their evolution in the dust growth process is investigated. It is found that as the dust grains grow the fractal dimension of the dust structure decreases. In addition, the fractal dimension of the center region is larger than that of the entire region in the 2D dust layer. In the initial growth stage, the small dust particulates at a high number density in a 2D layer tend to fill space as a normal surface with fractal dimension D = 2. The mechanism of the formation of fractal dust grains is discussed.

  3. Sahara Dust Cloud

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Dust Particles Click on the image for Quicktime movie from 7/15-7/24 A continent-sized cloud of hot air and dust originating from the Sahara Desert crossed the Atlantic Ocean and headed towards Florida and the Caribbean. A Saharan Air Layer, or SAL, forms when dry air and dust rise from Africa's west coast and ride the trade winds above the Atlantic Ocean. These dust clouds are not uncommon, especially during the months of July and August. They start when weather patterns called tropical waves pick up dust from the desert in North Africa, carry it a couple of miles into the atmosphere and drift westward. In a sequence of images created by data acquired by the Earth-orbiting Atmospheric Infrared Sounder ranging from July 15 through July 24, we see the distribution of the cloud in the atmosphere as it swirls off of Africa and heads across the ocean to the west. Using the unique silicate spectral signatures of dust in the thermal infrared, AIRS can detect the presence of dust in the atmosphere day or night. This detection works best if there are no clouds present on top of the dust; when clouds are present, they can interfere with the signal, making it much harder to detect dust as in the case of July 24, 2005. In the Quicktime movie, the scale at the bottom of the images shows +1 for dust definitely detected, and ranges down to -1 for no dust detected. The plots are averaged over a number of AIRS observations falling within grid boxes, and so it is possible to obtain fractional numbers. [figure removed for brevity, see original site] Total Water Vapor in the Atmosphere Around the Dust Cloud Click on the image for Quicktime movie The dust cloud is contained within a dry adiabatic layer which originates over the Sahara Desert. This Saharan Air Layer (SAL) advances Westward over the Atlantic Ocean, overriding the cool, moist air nearer the surface. This burst of very dry air is visible in the AIRS retrieved total water

  4. VALIDATION OF SIMULATION MODELS FOR DIFFERENTLY DESIGNED HEAT-PIPE EVACUATED TUBULAR COLLECTORS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Dragsted, Janne; Furbo, Simon

    2007-01-01

    Differently designed heat-pipe evacuated tubular collectors have been investigated theoretically and experimentally. The theoretical work has included development of two TRNSYS [1] simulation models for heat-pipe evacuated tubular collectors utilizing solar radiation from all directions. One model...... coating on both sides. The input to the models is thus not a simple collector efficiency expression but the actual collector geometry. In this study, the TRNSYS models are validated with measurements for four differently designed heat-pipe evacuated tubular collectors. The collectors are produced...

  5. Development of 12.5 m² Solar Collector Panel for Solar Heating Plants

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian; Furbo, Simon; Shah, Louise Jivan

    2004-01-01

    and large solar heating systems. Based on the theoretical findings a prototype of an improved HT solar collector was built and tested side-by-side with the original HT solar collector. The improved HT collector makes use of a changed insulation material, an absorber with improved absorptance and emittance......Theoretical and experimental investigations have elucidated how different changes in the design of the 12.5 m(2) HT flat-plate solar collector from the Danish company ARCON Solvarme A/S influence the solar collector efficiency and the yearly thermal performance. The collector is designed for medium...

  6. Evaluation of initial collector field performance at the Langley Solar Building Test Facility

    Science.gov (United States)

    Boyle, R. J.; Knoll, R. H.; Jensen, R. N.

    1977-01-01

    The thermal performance of the solar collector field for the NASA Langley Solar Building Test Facility is given for October 1976 through January 1977. An 1180 square meter solar collector field with seven collector designs helped to provide hot water for the building heating system and absorption air conditioner. The collectors were arranged in 12 rows with nominally 51 collectors per row. Heat transfer rates for each row are calculated and recorded along with sensor, insolation, and weather data every 5 minutes using a mini-computer. The agreement between the experimental and predicted collector efficiencies was generally within five percentage points.

  7. Electrodynamic Dust Shield Demonstrator

    Science.gov (United States)

    Stankie, Charles G.

    2013-01-01

    The objective of the project was to design and manufacture a device to demonstrate a new technology developed by NASA's Electrostatics and Surface Physics Laboratory. The technology itself is a system which uses magnetic principles to remove regolith dust from its surface. This project was to create an enclosure that will be used to demonstrate the effectiveness of the invention to The Office of the Chief Technologist. ONE of the most important challenges of space exploration is actually caused by something very small and seemingly insignificant. Dust in space, most notably on the moon and Mars, has caused many unforeseen issues. Dirt and dust on Earth, while a nuisance, can be easily cleaned and kept at bay. However, there is considerably less weathering and erosion in space. As a result, the microscopic particles are extremely rough and abrasive. They are also electrostatically charged, so they cling to everything they make contact with. This was first noted to be a major problem during the Apollo missions. Dust would stick to the spacesuits, and could not be wiped off as predicted. Dust was brought back into the spacecraft, and was even inhaled by astronauts. This is a major health hazard. Atmospheric storms and other events can also cause dust to coat surfaces of spacecraft. This can cause abrasive damage to the craft. The coating can also reduce the effectiveness of thermal insulation and solar panels.' A group of engineers at Kennedy Space Center's Electrostatics and Surface Physics Laboratory have developed a new technology, called the Electrodynamic Dust Shield, to help alleviate these problems. It is based off of the electric curtain concept developed at NASA in 1967. "The EDS is an active dust mitigation technology that uses traveling electric fields to transport electrostatically charged dust particles along surfaces. To generate the traveling electric fields, the EDS consists of a multilayer dielectric coating with an embedded thin electrode grid

  8. Absorber Alignment Measurement Tool for Solar Parabolic Trough Collectors: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Stynes, J. K.; Ihas, B.

    2012-04-01

    As we pursue efforts to lower the capital and installation costs of parabolic trough solar collectors, it is essential to maintain high optical performance. While there are many optical tools available to measure the reflector slope errors of parabolic trough solar collectors, there are few tools to measure the absorber alignment. A new method is presented here to measure the absorber alignment in two dimensions to within 0.5 cm. The absorber alignment is measured using a digital camera and four photogrammetric targets. Physical contact with the receiver absorber or glass is not necessary. The alignment of the absorber is measured along its full length so that sagging of the absorber can be quantified with this technique. The resulting absorber alignment measurement provides critical information required to accurately determine the intercept factor of a collector.

  9. Solar water disinfecting system using compound parabolic concentrating collector

    Energy Technology Data Exchange (ETDEWEB)

    El-Ghetany, H.H.; Saitoh, T.S. [Tohoku Univ., Sendai (Japan)

    2000-05-31

    Solar water disinfection is an alternative technology using solar radiation and thermal treatment to inactivate and destroy pathogenic microorganisms present in water. The Compound Parabolic Concentrating, (CPC) collector can be used as an efficient key component for solar disinfectanting system. Two types of the CPC collectors are studied, namely the transparent-tube and the Copper-tube CPC collector. It is found that after 30 minutes of exposing the water sample to solar radiation or heating it up to 65 degree C for a few minuets all the coliform bacterial present in the contaminated water sample were completely eliminated. In this article, the effect of water temperature on the disinfecting process was presented. Thermal and micro-biological measurements were also made to evaluate the system performance. (author)

  10. Optical losses due to tracking on solar thermal collectors

    DEFF Research Database (Denmark)

    Sallaberry, Fabienne; Pujol-Nadal, Ramn; Peres, Bengt

    2017-01-01

    For a wide range of operational temperatures, the solar thermal collectors can use optical concentration systems to optimize their efficiency. However, as optical concentration relies on direct solar radiation, it is necessary to use a solar tracker following the sun direction to maximize...... the amount of useful solar radiation received. The selection of the appropriate tracking systems matching the optical concentration factor is essential to achieve optimal collector efficiency. Otherwise, the concentrator would experience high optical losses due to the inadequate focusing of the direct solar...... radiation onto its receiver, regardless of its quality. This paper gives the state-of-the-art of the methodologies available to characterize the tracking error of a concentrating collector, a summary of different previous studies done in this subject and of the standardization regarding the tracking...

  11. Low cost bare-plate solar air collector

    Science.gov (United States)

    Maag, W. L.; Wenzler, C. J.; Rom, F. E.; Vanarsdale, D. R.

    1980-09-01

    A low cost, bare plate solar collector for preheating ambient air was developed. This type of solar heating system would be applicable for preheating ventilation air for public buildings or other commercial and industrial ventilation requirements. Two prototype collectors were designed, fabricated and installed into an instrumented test system. Tests were conducted for a period of five months. Results of the tests showed consistent operating efficiencies of 60 percent or greater with air preheat temperature uses up to 20 degrees for one of the prototypes. The economic analyses indicated that this type of solar system was economically viable. For the materials of construction and the type of fabrication and installation perceived, costs for the bare plate solar collector are attainable. Applications for preheating ventilation air for schools were evaluated and judged to be economically viable.

  12. Project 'Colored solar collectors' - Annual report 2004

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, A.; Chambrier, E. De; Roecker, Ch.; Scartezzini, J.-L.

    2004-12-15

    The architectural integration of thermal solar collectors into buildings is often limited by their black color, and the visibility of tubes and corrugations of the absorber sheets. A certain freedom in color choice would be desirable, but the colored appearance should not cause excessive performance degradation. Multilayered thin film interference filters on the collector glazing can produce a colored reflection, hiding the corrugated metal sheet, while transmitting the non-reflected radiation entirely to the absorber. These interference filters are designed and optimized by numerical simulation and shall be manufactured by the sol-gel dip-coating process. The proposed colored glazed solar collectors will be ideally suited for architectural integration into buildings, e.g. as solar active glass facades. The sol-gel fabrication of interference stacks of up to five layers of silicon and titanium oxide films could be demonstrated in the laboratory, in the first step on microscope slides. Optical measurements are used to determine film thicknesses and optical constants of the individual layers, and to measure color coordinates and solar transmission for the multilayer stacks. The solar transmission of such samples can be improved by titanium silicon mixed oxides, which could have been synthesized by the sol-gel method. Hereby the compatibility problems of the originally used solution have been solved, and the refractive index of the resulting mixed oxide can be perfectly controlled by tuning the atomic concentration ratio of silicon and titanium. One of the main technical risks is related to the fact that for a convincing demonstration of the idea high quality coatings are absolutely necessary. Therefore, visible defects induced during the dip-coating process by dust particles in the atmosphere or in the used solutions must be imperatively avoided, as well as thickness variations due to vibrations. After optimizing various aspects of sample preparation, processing and

  13. Project 'Colored solar collectors' - Annual report 2005

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, A.; Chambrier, E. De; Roecker, Ch.; Scartezzini, J.-L.

    2005-12-15

    The architectural integration of thermal solar collectors into buildings is often limited by their black color, and the visibility of tubes and corrugations of the absorber sheets. A certain freedom in color choice would be desirable, but the colored appearance should not cause excessive performance degradation. Multilayered thin film interference filters on the collector glazing can produce a colored reflection, hiding the corrugated metal sheet, while transmitting the non-reflected radiation entirely to the absorber. These interference filters are designed and optimized by numerical simulation and shall be manufactured by the sol-gel dip-coating process. The proposed colored glazed solar collectors will be ideally suited for architectural integration into buildings, e.g. as solar active glass facades. The availability of thin film materials with a refractive index lower than that of silicon favors a higher solar transmission at a given value of visible reflectance. The feasibility of the sol-gel deposition of such low refractive index materials has been demonstrated. For the development of nanostructured materials, analytical methods such as electron microscopy are extremely helpful. Important techniques of substrate pretreatment, sample cleaving, polishing, mounting, and microscope handling have been acquired. First measurements yield images of nanostructures produced by the sol-gel dip-coating process. Nanocomposite Ti{sub x}Si{sub 1-x}O{sub 2} thin films provide a large range of refractive indices. Aiming a high efficiency of the colored reflection, Ti{sub x}Si{sub 1-x}O{sub 2} based multilayered coatings have been designed and subsequently prepared by sol-gel dip-coating. The energy efficiency M = R{sub VIS}/(100%-T{sub sol}) of the obtained colored reflection amounts up to 2.4. For a convincing demonstration sufficiently large samples of high quality are imperatively needed. An infrastructure for the handling of A4 sized samples has been established

  14. Liquid metal current collectors for high-speed rotating machinery

    International Nuclear Information System (INIS)

    Carr, S.L.

    1976-01-01

    Recent interest in superconducting motors and generators has created a renewed interest in homopolar machinery. Homopolar machine designs have always been limited by the need for compact, high-current, low-voltage, sliding electrical curent collectors. Conventional graphite-based solid brushes are inadequate for use in homopolar machines. Liquid metals, under certain conditions of relative sliding velocities, electrical currents, and magnetic fields are known to be capable of performing well in homopolar machines. An effort to explore the capabilities and limits of a tongue-and-groove style current collector, utilizing sodium-potassium eutectic alloy (NaK) as the working fluid in high sliding speed operation is reported here. A double current collector generator model with a 14.5-cm maximum rotor diameter, 20,000 rpm rotational capability, and electrical current carrying ability was constructed and operated successfully at a peripheral velocity of 125 m/s. The limiting factor in these experiments was a high-speed fluid-flow instability resulting in the ejection of the working fluid from the operating portions of the collectors. The effects of collector size and geometry, working fluid (NaK or water), and cover gas pressure are reported. Hydrodynamic frictional torque-speed curves are given for the two fluids and for several geometries. Electrical resistances as a function of peripheral velocity at 60 amperes are reported, and the phenomenology of the high-speed fluid-flow instabilities is discussed. The possibility of long-term high-speed operation of current collectors of the tongue-and-groove type, along with experimental and theoretical hydrodynamic friction losses at high peripheral velocities, is considered

  15. Geochemical characterization of critical dust source regions in the American West

    Science.gov (United States)

    Aarons, Sarah M.; Blakowski, Molly A.; Aciego, Sarah M.; Stevenson, Emily I.; Sims, Kenneth W. W.; Scott, Sean R.; Aarons, Charles

    2017-10-01

    The generation, transport, and deposition of mineral dust are detectable in paleoclimate records from land, ocean, and ice, providing valuable insight into earth surface conditions and cycles on a range of timescales. Dust deposited in marine and terrestrial ecosystems can provide critical nutrients to nutrient-limited ecosystems, and variations in dust provenance can indicate changes in dust production, sources and transport pathways as a function of climate variability and land use change. Thus, temporal changes in locations of dust source areas and transport pathways have implications for understanding interactions between mineral dust, global climate, and biogeochemical cycles. This work characterizes dust from areas in the American West known for dust events and/or affected by increasing human settlement and livestock grazing during the last 150 years. Dust generation and uplift from these dust source areas depends on climate and land use practices, and the relative contribution of dust has likely changed since the expansion of industrialization and agriculture into the western United States. We present elemental and isotopic analysis of 28 potential dust source area samples analyzed using Thermal Ionization Mass Spectrometry (TIMS) for 87Sr/86Sr and 143Nd/144Nd composition and Multi-Collector Inductively Coupled Plasma Mass Spectrometer (MC-ICPMS) for 176Hf/177Hf composition, and ICPMS for major and trace element concentrations. We find significant variability in the Sr, Nd, and Hf isotope compositions of potential source areas of dust throughout western North America, ranging from 87Sr/86Sr = 0.703699 to 0.740236, εNd = -26.6 to 2.4, and εHf = -21.7 to -0.1. We also report differences in the trace metal and phosphorus concentrations in the geologic provinces sampled. This research provides an important resource for the geochemical tracing of dust sources and sinks in western North America, and will aid in modeling the biogeochemical impacts of increased

  16. On the Adsorption of Some Anionic Collectors on Fluoride Minerals

    DEFF Research Database (Denmark)

    Sørensen, Emil

    1973-01-01

    Test flotations have been carried out in a small apparatus under standardized conditions in order to determine the dependence of the flotation yield on the reagent concentration for certain minerals and anionic collectors. The results suggest that a special adsorption mechanism is operating...... in the case of fluoride minerals, and a theory is presented which involves the joint action of ionic and hydrogen bonds. A precondition is the compatibility of the crystal geometry with the configuration of the polar group of the collector molecules....

  17. Studies of impurity recycling by the collector probe technique

    International Nuclear Information System (INIS)

    Hildebrandt, D.; Grote, H.; Herrmann, A.; Laux, M.; Pech, P.; Reiner, H.D.; Wolff, H.

    1987-01-01

    In order to study recycling effects of the nonintrinsic impurity Li discharges with and without LiD-pellet injection were investigated. The observed maximum impurity level of Li in the SOL plasma of discharges without injection reaches less than 10% of that observed in discharges with injection. The measurements offer the possibility to distinguish between influxes from the wall and those which reach the collector probe via the core plasma. The time evolution, orientation and radial dependence of the impurity fluxes are characteristic features of their origin. The consideration of all these features facilitates a better understanding of collector probe measurements in the SOL-plasma. (orig.)

  18. Two Fixed, Evacuated, Glass, Solar Collectors Using Nonimaging Concentration

    Science.gov (United States)

    Garrison, John D.; Winston, Roland; O'Gallagher, Joseph; Ford, Gary

    1984-01-01

    Two fixed, evacuated, glass solar thermal collectors have been designed. The incorporation of nonimaging concentration, selective absorption and vacuum insulation into their design is essential for obtaining high efficiency through low heat loss, while operating at high temperatures. Nonimaging, approximately ideal concentration with wide acceptance angle permits solar radiation collection without tracking the sun, and insures collection of much of the diffuse radiation. It also minimizes the area of the absorbing surface, thereby reducing the radiation heat loss. Functional integration, where different parts of these two collectors serve more than one function, is also important in achieving high efficiency, and it reduces cost.

  19. Opensource Software for MLR-Modelling of Solar Collectors

    DEFF Research Database (Denmark)

    Bacher, Peder; Perers, Bengt

    2011-01-01

    A first research version is now in operation of a software package for multiple linear regression (MLR) modeling and analysis of solar collectors according to ideas originating all the way from Walletun et. al. (1986), Perers, (1987 and 1993). The tool has been implemented in the free and open...... source program R http://www.r-project.org/. Applications of the software package includes: visual validation, resampling and conversion of data, collector performance testing analysis according to the European Standard EN 12975 (Fischer et al., 2004), statistical validation of results...

  20. Tracking local control of a parabolic trough collector

    International Nuclear Information System (INIS)

    Ajona, J.I.; Alberdi, J.; Gamero, E.; Blanco, J.

    1992-01-01

    In the local control, the sun position related to the trough collector is measured by two photo-resistors. The provided electronic signal is then compared with reference levels in order to get a set of B logical signals which form a byte. This byte and the commands issued by a programmable controller are connected to the inputs of o P.R.O.M. memory which is programmed with the logical equations of the control system. The memory output lines give the control command of the parabolic trough collector motor. (Author)

  1. Dust in planetary nebulae

    International Nuclear Information System (INIS)

    Kwok, S.

    1980-01-01

    A two-component dust model is suggested to explain the infrared emission from planetary nebulae. A cold dust component located in the extensive remnant of the red-giant envelope exterior to the visible nebula is responsible for the far-infrared emission. A ward dust component, which is condensed after the formation of the planetary nebula and confined within the ionized gas shell, emits most of the near- and mid-infrared radiation. The observations of NGC 7027 are shown to be consisten with such a model. The correlation of silicate emission in several planetary nebulae with an approximately +1 spectral index at low radio frequencies suggests that both the silicate and radio emissions originate from the remnant of the circumstellar envelope of th precursor star and are observable only while the planetary nebula is young. It is argued that oxygen-rich stars as well as carbon-rich stars can be progenitors of planetary nebulae

  2. Interstellar dust and extinction

    International Nuclear Information System (INIS)

    Mathis, J.S.

    1990-01-01

    It is noted that the term interstellar dust refers to materials with rather different properties, and that the mean extinction law of Seaton (1979) or Savage and Mathis (1979) should be replaced by the expression given by Cardelli et al. (1989), using the appropriate value of total-to-selective extinction. The older laws were appropriate for the diffuse ISM but dust in clouds differs dramatically in its extinction law. Dust is heavily processed while in the ISM by being included within clouds and cycled back into the diffuse ISM many times during its lifetime. Hence, grains probably reflect only a trace of their origin, although meteoritic inclusions with isotopic anomalies demonstrate that some tiny particles survive intact from a supernova origin to the present. 186 refs

  3. Dust control for draglines

    Energy Technology Data Exchange (ETDEWEB)

    Grad, P.

    2009-09-15

    Monitoring dust levels inside draglines reveals room for improvement in how filtration systems are used and maintained. The Australian firm BMT conducted a field test program to measure airflow parameters, dust fallout rates and dust concentrations, inside and outside the machine house, on four draglines and one shovel. The study involved computational fluid dynamics (CFD) simulations. The article describes how the tests were made and gives results. It was not possible to say which of the two main filtration systems currently used on Australian draglines - Dynavane or Floseps - performs better. It would appear that more frequent maintenance and cleaning would increase the overall filtration performance and systems could be susceptible to repeat clogging in a short time. 2 figs., 1 photos.

  4. DustEM: Dust extinction and emission modelling

    Science.gov (United States)

    Compiègne, M.; Verstraete, L.; Jones, A.; Bernard, J.-P.; Boulanger, F.; Flagey, N.; Le Bourlot, J.; Paradis, D.; Ysard, N.

    2013-07-01

    DustEM computes the extinction and the emission of interstellar dust grains heated by photons. It is written in Fortran 95 and is jointly developed by IAS and CESR. The dust emission is calculated in the optically thin limit (no radiative transfer) and the default spectral range is 40 to 108 nm. The code is designed so dust properties can easily be changed and mixed and to allow for the inclusion of new grain physics.

  5. Simulating STARDUST: Reproducing Impacts of Interstellar Dust in the Laboratory

    Science.gov (United States)

    Postberg, F.; Srama, R.; Hillier, J. K.; Sestak, S.; Green, S. F.; Trieloff, M.; Grün, E.

    2008-09-01

    Our experiments are carried out to support the analysis of interstellar dust grains, ISDGs, brought to earth by the STARDUST mission. Since the very first investigations, it has turned out that the major problem of STARDUST particle analysis is the modification (partly even the destruction) during capture when particles impact the spacecraft collectors with a velocity of up to 20 km/s. While it is possible to identify, extract, and analyse cometary grains larger than a few microns in aerogel and on metal collector plates, the STARDUST team is not yet ready for the identification, extraction, and analysis of sub-micron sized ISDGs with impact speeds of up to 20 km/s. Reconstructing the original particle properties requires a simulation of this impact capture process. Moreover, due to the lack of laboratory studies of high speed impacts of micron scale dust into interstellar STARDUST flight spares, the selection of criteria for the identification of track candidates is entirely subjective. Simulation of such impact processes is attempted with funds of the FRONTIER program within the framework of the Heidelberg University initiative of excellence. The dust accelerator at the MPI Kernphysik is a facility unique in the world to perform such experiments. A critical point is the production of cometary and interstellar dust analogue material and its acceleration to very high speeds of 20 km/s, which has never before been performed in laboratory experiments. Up to now only conductive material was successfully accelerated by the 2 MV Van de Graaf generator of the dust accelerator facility. Typical projectile materials are Iron, Aluminium, Carbon, Copper, Silver, and the conducting hydrocarbon Latex. Ongoing research now enables the acceleration of any kind of rocky planetary and interstellar dust analogues (Hillier et al. 2008, in prep.). The first batch of dust samples produced with the new method consists of micron and submicron SiO2 grains. Those were successfully

  6. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    Rosenberg, M.

    2010-01-01

    The objective of our theoretical research under this grant over the past 3 years was to develop new understanding in a range of topics in the physics of dust-plasma interactions, with application to space and the laboratory. We conducted studies related to the physical properties of dust, waves and instabilities in both weakly coupled and strongly coupled dusty plasmas, and innovative possible applications. A major consideration in our choice of topics was to compare theory with experiments or observations, and to motivate new experiments, which we believe is important for developing this relatively new field. Our research is summarized, with reference to our list of journal publications.

  7. Determining the Influence of Dust on Post-Glacial Lacustrine Sedimentation in Bald Lake, Uinta Mountains, Utah

    Science.gov (United States)

    O'Keefe, S. S.; McElroy, R.; Munroe, J. S.

    2016-12-01

    Dust is increasingly recognized as an important component of biogeochemical cycling and ecosystem function in mountain environments. Previous work has shown that delivery of dust to the Uinta Mountains of northeastern Utah has influenced pedogenesis, soil nutrient status, and surface water chemistry. An array of passive and active samplers in the alpine zone of the Uintas provides detailed information about contemporary dust fluxes, along with physical and geochemical properties of modern dust. Reconstruction of changes in the dust system over time, however, requires continuous sedimentary archives sensitive to dust inputs. A radiocarbon-dated 3.5-m core (spanning 12.7 kyr) collected from subalpine Bald Lake may provide such a record. Passive dust collectors in the vicinity of the lake constrain the geochemical properties of modern dust, whereas samples of regolith constrain properties of the local surficial material within the watershed. Together, these represent two end member sources of clastic sediment to Bald Lake basin: allochthonous dust and autochthonous regolith. Ba and Eu are found in higher abundances in the dust than in the watershed regolith. Zr and Th are found to be lower in the dust than in the watershed. Geochemical analysis of the sediment core allows the relative contribution of exotic and local material to the lake to be considered as a time series covering the post-glacial interval when indicator elements are plotted. Findings suggest Bald Lake's dust record tracks regional aridity and corresponds to low-stands of large lakes in the southwestern United States. Spatial variability of elemental abundances in the watershed suggests there are more than two input sources contributing to the lake over time.

  8. Control of harmful dust in coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, B; Bower, K; Mitchell, D

    1973-01-01

    This handbook consists of a series of short chapters devoted to: sources of airborne dust; dust standards and methods of sampling; dust prevention on mechanized faces; ventilation and dust extraction; distribution and use of water; dust control on mechanized faces; dust control in drivages and headings; drilling and shotfiring; dust control in transport; some outbye dust control techniques (hygroscopic salts, impingement curtains); water infusion; personal protective equipment. (CIS Abstr.)

  9. Dust evolution in protoplanetary disks

    OpenAIRE

    Gonzalez , Jean-François; Fouchet , Laure; T. Maddison , Sarah; Laibe , Guillaume

    2007-01-01

    6 pages, 5 figures, to appear in the Proceedings of IAU Symp. 249: Exoplanets: Detection, Formation and Dynamics (Suzhou, China); International audience; We investigate the behaviour of dust in protoplanetary disks under the action of gas drag using our 3D, two-fluid (gas+dust) SPH code. We present the evolution of the dust spatial distribution in global simulations of planetless disks as well as of disks containing an already formed planet. The resulting dust structures vary strongly with pa...

  10. Respirable versus inhalable dust sampling

    International Nuclear Information System (INIS)

    Hondros, J.

    1987-01-01

    The ICRP uses a total inhalable dust figure as the basis of calculations on employee lung dose. This paper was written to look at one aspect of the Olympic Dam dust situation, namely, the inhalable versus respirable fraction of the dust cloud. The results of this study will determine whether it is possible to use respirable dust figures, as obtained during routine monitoring to help in the calculations of employee exposure to internal radioactive contaminants

  11. Performance Analysis of Fractional-Order PID Controller for a Parabolic Distributed Solar Collector

    KAUST Repository

    Elmetennani, Shahrazed; N'Doye, Ibrahima; Salama, Khaled N.; Laleg-Kirati, Taous-Meriem

    2017-01-01

    This paper studies the performance of a fractional-order proportional integral derivative (FOPID) controller designed for parabolic distributed solar collectors. The control problem addressed in concentrated solar collectors aims at forcing

  12. FLOW DISTRIBUTION IN A SOLAR COLLECTOR PANEL WITH HORIZONTAL ABSORBER STRIPS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    2007-01-01

    The objective of this work is to theoretically and experimentally investigate the flow and temperature distribution in a solar collector panel with an absorber consisting of horizontal strips. Fluid flow and heat transfer in the collector panel are studied by means of computational fluid dynamics...... (CFD) calculations. Further, experimental investigations of a 12.5 m² solar collector panel with 16 parallel connected horizontal fins are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the backside of the absorber tubes. The measured...... collector fluid, and by increased collector tilt and inlet temperature, the flow distribution gets worse resulting in a decreased collector efficiency and an increased risk of boiling in the upper part of the collector panel. Keywords: Solar collector; Flow distribution; Computational Fluid Dynamics (CFD...

  13. The Effect of the Volume Flow rate on the Efficiency of a Solar Collector

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    rates. Theoretically, a simplified model of the solar collector panel is built by means of the CFD (Computational Fluid Dynamics) code Fluent, where the geometry of the collector panel except the casing is fully modeled. Both lateral and longitudinal heat conduction in the absorber fins, the heat...... transfer from the absorber to the solar collector fluid and the heat loss from the absorber are considered. Flow and temperature distribution in the collector panel are investigated with buoyancy effect. Measurements are carried out with the solar collector panel. Collector efficiencies are measured......The flow distribution inside a collector panel with an area of 12.5 m² and with 16 parallel connected horizontal fins and the effect of the flow nonuniformity on the risk of boiling and on the collector efficiency have been theoretically and experimentally investigated for different volume flow...

  14. Low-cost solar collectors using thin-film plastics absorbers and glazings

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelm, W.G.

    1980-01-01

    The design, fabrication, performance, cost, and marketing of flat plate solar collectors using plastic absorbers and glazings are described. Manufacturing cost breakdowns are given for single-glazed and double-glazed collectors. (WHK)

  15. Optimization of flat-plate solar energy heat pipe collector parameters

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, L L; Garakovich, L P; Khrustalev, D K

    1984-01-01

    Performance characteristics of flat solar energy collectors with heat pipes have been analysed with regard to various parameters. Their advantages are discussed. The use of heat pipes in solar energy collectors is proved to be efficient.

  16. Paleo-dust insights onto dust-climate interactions

    Science.gov (United States)

    Albani, S.; Mahowald, N. M.

    2017-12-01

    Mineral dust emissions are affected by changing climate conditions, and in turn dust impacts the atmospheric radiation budget, clouds and biogeochemical cycles. Climate and public health dust-related issues call for attention on the fate of the dust cycle in the future, and the representation of the dust cycle is now part of the strategy of the Paleoclimate Modelling Intercomparison Project phase 4 and the Coupled Model Intercomparison Project phase 6 (PMIP4-CMIP6). Since mineral aerosols are one of the most important natural aerosols, understanding past dust responses to climate in the paleoclimate will allow us to better understand mineral aerosol feedbacks with climate and biogeochemistry in the Anthropocene. Modern observations and paleoclimate records offer the possibility of multiple, complementary views on the global dust cycle, and allow to validate and/or constrain the numerical representation of dust in climate and Earth system models. We present our results from a set of simulations with the Community Earth System Model for different climate states, including present and past climates such as the pre-industrial, the mid-Holocene and the Last Glacial Maximum. A set of simulations including a prognostic dust cycle was thoroughly compared with a wide set of present day observations from different platforms and regions, in order to realistically constrain the magnitude of dust load, surface concentration, deposition, optical properties, and particle size distributions. The magnitude of emissions for past climate regimes was constrained based on compilations of paleodust mass accumulation rates and size distributions, as well as based on information on dust provenance. The comparison with a parallel set of simulations without dust allows estimating the impacts of dust on surface climate. We analyze impacts of dust on the mean and variability of surface temperature and precipitation in each climate state, as well as the impacts that changing dust emissions had

  17. The modelling of solar radiation quantities and intensities in a two dimensional compound parabolic collector

    OpenAIRE

    2010-01-01

    M.Ing. A dissertation presented on the basic solar design principles such as sun-earth geometry, energy wavelengths, optics, incidence angles, parabolic collector configurations and design, materials for solar applications, efficiencies, etc to be considered in Solar Concentrating Collector design. These principles were applied in the design and fabrication of a prototype solar collector. The solar collector was tested to verify and correct mathematical models that were generated from exis...

  18. Development of a Polymer-carbon Nanotubes based Economic Solar Collector

    OpenAIRE

    Kim, S. I.; Kissick, John; Spence, Stephen; Boyle, Christine

    2014-01-01

    A low cost solar collector was developed by using polymeric components as opposed to metal and glass components of traditional solar collectors. In order to utilize polymers for the absorber of the solar collector, Carbon Nanotubes (CNT) has been added as a filler to improve the thermal conductivity and the solar absorptivity of polymers. The solar collector was designed as a multi-layer construction with considering the economic manufacturing. Through the mathematical heat transfer analysis,...

  19. Erosion of dust aggregates

    NARCIS (Netherlands)

    Seizinger, A.; Krijt, S.; Kley, W.

    2013-01-01

    Aims: The aim of this work is to gain a deeper insight into how much different aggregate types are affected by erosion. Especially, it is important to study the influence of the velocity of the impacting projectiles. We also want to provide models for dust growth in protoplanetary disks with simple

  20. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    Rosenberg, Marelene

    2005-01-01

    Our theoretical research on dust-plasma interactions has concentrated on three main areas: (a)studies of grain charging and applications; (b) waves and instabilities in weakly correlated dusty plasma with applications to space and laboratory plasmas; (c) waves in strongly coupled dusty plasmas.

  1. From dust to life

    Science.gov (United States)

    Wickramasinghe, Chandra

    After initially challenging the dirty-ice theory of interstellar grains, Fred Hoyle and the present author proposed carbon (graphite) grains, mixtures of refractory grains, organic polymers, biochemicals and finally bacterial grains as models of interstellar dust. The present contribution summarizes this trend and reviews the main arguments supporting a modern version of panspermia.

  2. Solar collectors for swimming pools still going strong

    Energy Technology Data Exchange (ETDEWEB)

    1975-01-01

    According to the opinion of the experts, solar energy heating may be technically 'mature' but the profitability is by no means that far. However, solar systems are a good alternative for heating the water in swimming pools. Four solar collector systems developed by different firms to heat swimming pools, including prices, are presented.

  3. 10 CFR 26.85 - Collector qualifications and responsibilities.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Collector qualifications and responsibilities. 26.85 Section 26.85 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Collecting Specimens for... reports, if any; results of tests to establish employee competency for the position he or she holds...

  4. A Distributed Garbage Collector for NeXeme

    OpenAIRE

    Moreau, Luc; DeRoure, David

    1997-01-01

    The remote service request, a form of remote procedure call, and the global pointer, a global naming mechanism, are two features at the heart of Nexus, a library to build distributed systems. nexeme is an extension of Scheme that fully integrates both concepts in a mostly-functional framework. This short paper describes the distributed garbage collector that we implemented in nexeme.

  5. Thermo-ecological optimization of a solar collector

    International Nuclear Information System (INIS)

    Szargut, J.; Stanek, W.

    2007-01-01

    The depletion of non-renewable natural exergy resources (the thermo-ecological cost) has been accepted as the objective function for thermo-ecological optimization. Its general formulation has been cited. A detailed form of the objective function has been formulated for a solar collector producing hot water for household needs. The following design parameters have been accepted as the decision variables: the collector area per unit of the heat demand, the diameter of collector pipes, the distance of the pipe axes in the collector plate. The design parameters of the internal installation (the pipes, the hot water receiver) have not been taken into account, because they are very individual. The accumulation ability of hot water comprising one day has been assumed. The objective function contains the following components: the thermo-ecological cost of copper plate, copper pipes, glass plate, steel box, thermal insulation, heat transfer liquid, electricity for driving the pump of liquid, fuel for the peak boiler. The duration curves of the flux of solar radiation and absorbed heat have been elaborated according to meteorological data and used in the calculations. The objective function for economic optimization may have a similar form, only the cost values would be different

  6. Development of nonmetallic solar collector and solar-powered pump

    Science.gov (United States)

    Parker, J. C.

    1979-01-01

    Design and building of two unique components for solar heating (1. flatplate solar collector using no metal components, and 2. solar powered pump for heating and cooling systems are outlined in report. Report also discusses hardware, deliverable end items, problems encountered during fabrication and testing, and performance certification.

  7. Optimization of reflector-boosters for solar flat-collectors

    Energy Technology Data Exchange (ETDEWEB)

    Profant, M; Weidner, P; Boettcher, A

    1979-04-01

    To increase the working temperature of solar energy systems two-sided collectors together with appropriate reflectors are used. Here, the efficiency of various reflector shapes was investigated and attempts made to optimize them under several criteria. The results indicate that with cheap and simple to manufacture reflectors good energy gains can be expected.

  8. Development of a selective surface vacuum collector. Final report

    Energy Technology Data Exchange (ETDEWEB)

    de Waal, H.; Simonis, F.

    1980-01-01

    To make solar energy useful for cooling applications a flat plate high performance collector, which can supply solar energy at 100 to 150/sup 0/C, has been developed. To achieve a reasonable efficiency at these temperatures the thermal heat loss must be very small. This has been obtained by (1) concentration of sunlight (c = 1.6); (2) evacuation of the collector housing to eliminate convection currents (pressure less than or equal to 4kPa); (3) spectral selective coating on the absorber; and (4) a low conductive gas in the collector housing (pressure approx. = 2kPa). The collector consists of a metal box with a glass cover hermetically sealed to it in the way double glazing units are manufactured. The sides of the V-trough concentrators support the glass cover. Measurements have been performed concerning heat loss factor and durability of the vacuum. The first prototype, fitted with a spectral selective coating of tin-oxide on enameled steel (epsilon = 0.25) showed a heat-loss of 2.0 W/m/sup 2/ /sup 0/C at 90/sup 0/C, being in reasonable agreement with calculations. Improvements with respect to the spectral selective coating and the use of a low conductive gas are necessary and will lead to a heat loss factor of about 1 W/m/sup 2/ /sup 0/C. Measurements have shown that in the chosen system the desired vacuum level can be maintained for at least 10 to 15 years.

  9. Liquid metal current collector applications and material compatibility

    International Nuclear Information System (INIS)

    Carr, S.L.; Stevens, H.O.

    1978-01-01

    The objective of this paper has been to summarize briefly the material considerations involved in the development of liquid metal current collectors for homopolar machinery applications. A significant amount of data in this regard has been obtained over the last several years by individual researchers for NaK exposure conditions. However, NaK material compatibility data over the entire time and temperature range of interest is highly desirable. At DTNSRDC, a 300 kW superconducting homopolar motor and generator are under test, both utilizing free surface tongue-and-groove current collectors with NaK as the working fluid. In addition to demonstrating the feasibility of other aspects of machine design, the intention is to use these machines as vehicles for testing of the several liquid metal current collector concepts which are considered worthwhile candidates for incorporation in future full-scale machines. It is likely that the optimal collector approach for a large low speed motor may be quite different from that for a smaller high speed generator, possibly involving the use of different liquid metals

  10. Greenhouse heating with a fresh water floating collector solar pond

    International Nuclear Information System (INIS)

    Arbel, A.; Sokolov, M.

    1991-01-01

    The fresh water floating collector solar pond was investigated both experimentally and theoretically in a previous work, and it is now matched, by simulation, with the heat load requirements of a greenhouse. Results of the simulation indicate that such a pond is a potential energy source for greenhouse heating. This is especially true when the material properties are such that solar absorption and storage are enhanced. This paper reports that to demonstrate this point, three sets of collectors constructed with materials of different physical (radiation) properties were tested. One set is constructed of common materials which are readily available and are normally used as covers for greenhouses. The second set made of improved materials which are also available but have a smaller long-wave transmittance. The last set made of ideal material which additionally possesses selective radiation absorption properties. Collectors made of ideal materials make a superior solar pond; thus, manufacturing films with improved properties should become a worthwhile challenge for the agricultural polyethylene-films industry. Preliminary economic studies indicate that even with the low oil (<$20/Bbl) prices which exist between 1986-1989, the fresh water floating collectors solar pond provides an economically attractive alternative to the conventional oil-burning heating system. This is especially true in mild climate areas and when the large initial investment is justified by long-term greenhouse utilization planning

  11. Optimal tilt-angles for solar collectors used in China

    International Nuclear Information System (INIS)

    Tang Runsheng; Wu Tong

    2004-01-01

    A reasonable estimation of the optimal tilt angle of a fixed collector for maximizing its energy collection must be done based on the monthly global and diffuse radiation on a horizontal surface. However, the monthly diffuse radiation is not always available in many places. In this paper, a simple mathematical procedure for the estimation of the optimal tilt angle of a collector is presented based on the monthly horizontal radiation. A comparison of the optimal tilt angles of collectors obtained from expected monthly diffuse radiation and that from the actual monthly diffuse radiation showed that this method gives a good estimation of the optimal tilt angle, except for places with a considerably lower clearness index. A contour map of the optimal tilt angle of the south-facing collectors used for the entire year in China is also outlined, based on monthly horizontal radiation of 152 places around the country, combing the optimal tilt angle of another 30 cities based on the actual monthly diffuse radiation

  12. Impedance of thin film cathodes: thickness and current collector dependence

    NARCIS (Netherlands)

    Boukamp, Bernard A.; Hildenbrand, N.; Bouwmeester, Henricus J.M.; Blank, David H.A.

    2015-01-01

    The influence of the layer thickness of mixed ionic–electronic conducting (MIEC) cathodes and the type of noble metal current collector on the apparent surface exchange resistance is studied with impedance spectroscopy. The impedance data is analyzed with the ‘General Finite Length Diffusion’

  13. Optimization of insulation of a linear Fresnel collector

    Science.gov (United States)

    Ardekani, Mohammad Moghimi; Craig, Ken J.; Meyer, Josua P.

    2017-06-01

    This study presents a simulation based optimization study of insulation around the cavity receiver of a Linear Fresnel Collector. This optimization study focuses on minimizing heat losses from a cavity receiver (maximizing plant thermal efficiency), while minimizing insulation cross-sectional area (minimizing material cost and cavity dead load), which leads to a cheaper and thermally more efficient LFC cavity receiver.

  14. The Effectiveness of a Collector Bag for Measurement of Post ...

    African Journals Online (AJOL)

    The aim of the study was to assess sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of collector bag and its correlation with hemoglobin (Hb) and hematocrit (Ht) variations. This study, carried on 100 women referred for admission to labor ward of Shohada hospital in Orumeyeh City, Iran, ...

  15. Macrofauna Settlement on Pearl Oyster Collectors in Kenya ...

    African Journals Online (AJOL)

    Key words: Pearl oysters, seed collection, macrofauna, bivalves, settlement, monsoon seasons,. Kenya .... have shown that pearl oyster settlement is higher within calm ...... collectors in the Timor Sea, Northern Australia. J. Shellfish ... systems. Aquaculture, 189: 375-388. Urban, H.J. (2000b): Culture potential of the pearl.

  16. Solar Thermal AIR Collector Based on New Type Selective Coating

    Directory of Open Access Journals (Sweden)

    Musiy, R.Y.

    2014-01-01

    Full Text Available Based on the best for optical performance and selective coating solar thermal air collector, which operates by solar power on the principle of simultaneous ventilation and heating facilities, is designed. It can be used for vacation homes, museums, wooden churches, warehouses, garages, houses, greenhouses etc.

  17. Modelling dust transport in tokamaks

    International Nuclear Information System (INIS)

    Martin, J.D.; Martin, J.D.; Bacharis, M.; Coppins, M.; Counsell, G.F.; Allen, J.E.; Counsell, G.F.

    2008-01-01

    The DTOKS code, which models dust transport through tokamak plasmas, is described. The floating potential and charge of a dust grain in a plasma and the fluxes of energy to and from it are calculated. From this model, the temperature of the dust grain can be estimated. A plasma background is supplied by a standard tokamak edge modelling code (B2SOLPS5.0), and dust transport through MAST (the Mega-Amp Spherical Tokamak) and ITER plasmas is presented. We conclude that micron-radius tungsten dust can reach the separatrix in ITER. (authors)

  18. Two year follow-up of a garbage collector with allergic bronchopulmonary aspergillosis (ABPA).

    Science.gov (United States)

    Allmers, H; Huber, H; Baur, X

    2000-04-01

    Separate collection of biodegradable garbage and recyclable waste is expected to become mandatory in some western countries. A growing number of persons engaged in garbage collection and separation might become endangered by high loads of bacteria and fungi. Case history and examination A 29 year old garbage collector involved in emptying so-called biological garbage complained of dyspnea, fever, and flu-like symptoms during work beginning in the summer of 1992. Chest x-ray showed streaky shadows near both hili reaching into the upper regions. IgE- and IgG-antibodies (CAP, Pharmacia, Sweden) were strongly positive for Aspergillus fumigatus with 90.5 kU/L and 186%, respectively. Total-IgE was also strongly elevated with 5430 kU/L. Bronchial challenge testing with commercially available Aspergillus fumigatus extract resulted in an immediate-type asthmatic reaction. Two years later he was still symptomatic and antibodies persisted at lower levels. Our diagnosis was allergic bronchopulmonary aspergillosis (ABPA) including asthmatic responses as well as hypersensitivity pneumonitis (extrinsic allergic alveolitis) due to exposure to moldy household waste. A growing number of persons engaged in garbage collection and handling are exposed and at risk to develop sensitization to fungi due to exposure to dust of biodegradable waste. Further studies are necessary to show if separate collection of biodegradable waste increases the health risks due to exposure to bacteria and fungi in comparison to waste collection without separation. Copyright 2000 Wiley-Liss, Inc.

  19. Drying of Rosella (Hibiscus sabdariffa Flower Petals using Solar Dryer with Double Glass Cover Collector

    Directory of Open Access Journals (Sweden)

    Tjukup Marnoto

    2014-10-01

    Full Text Available Chemical ingredients in rosella petals are very beneficial for health. Rosella petals needed to be drained for storage and packing purpose. The traditional drying takes 5 days and less healthy. Solar dryer technology can speed up the drying process and protect materials from dust contamination. Solar dryer with double glass covered collector has been designed and made for drying of agricultural products such as rosella flowers. Rosella petals as much as 2300 grams with initial moisture content of 90.84 % be dried with this dryer until the moisture content of 7.67 % takes only 2 days, although the weather was less sunny . The temperature in the drying chamber was not more than 50° C, so it was good for drying groceries, not damaging chemical ingredients. The relative humidity in the space dryeris was about 40 % and it was still relative low. Drying rate and drying performance was expressed by the efficiency and Specific Moisture Evaporation Rate ( SMER were influenced by water content of the dried material and weather. Daily efficiency at the first and the second day: 14.931 % and 5.78%, while the daily SMER on the first and the second day: 0.222 and 0.0256 ( kg / kWh .

  20. Comparative analyses on dynamic performances of photovoltaic–thermal solar collectors integrated with phase change materials

    International Nuclear Information System (INIS)

    Su, Di; Jia, Yuting; Alva, Guruprasad; Liu, Lingkun; Fang, Guiyin

    2017-01-01

    Highlights: • The dynamic model of photovoltaic–thermal collector with phase change material was developed. • The performances of photovoltaic–thermal collector are performed comparative analyses. • The performances of photovoltaic–thermal collector with phase change material were evaluated. • Upper phase change material mode can improve performances of photovoltaic–thermal collector. - Abstract: The operating conditions (especially temperature) of photovoltaic–thermal solar collectors have significant influence on dynamic performance of the hybrid photovoltaic–thermal solar collectors. Only a small percentage of incoming solar radiation can be converted into electricity, and the rest is converted into heat. This heat leads to a decrease in efficiency of the photovoltaic module. In order to improve the performance of the hybrid photovoltaic–thermal solar collector, we performed comparative analyses on a hybrid photovoltaic–thermal solar collector integrated with phase change material. Electrical and thermal parameters like solar cell temperature, outlet temperature of air, electrical power, thermal power, electrical efficiency, thermal efficiency and overall efficiency are simulated and analyzed to evaluate the dynamic performance of the hybrid photovoltaic–thermal collector. It is found that the position of phase change material layer in the photovoltaic–thermal collector has a significant effect on the performance of the photovoltaic–thermal collector. The results indicate that upper phase change material mode in the photovoltaic–thermal collector can significantly improve the thermal and electrical performance of photovoltaic–thermal collector. It is found that overall efficiency of photovoltaic–thermal collector in ‘upper phase change material’ mode is 10.7% higher than that in ‘no phase change material’ mode. Further, for a photovoltaic–thermal collector with upper phase change material, it is verified that 3 cm

  1. Development of an economic solar heating system with cost efficient flat plate collectors

    Science.gov (United States)

    Eder-Milchgeisser, W.; Burkart, R.

    1980-10-01

    Mass produced flat plate solar collectors were worked into the design of a system for heating a swimming pool and/or providing domestic hot water. The collector characteristics, including physical and mechanical data as well as theoretical energy conversion efficiency, are presented. The collector was tested and service life efficiency was determined. The mounting of the collector, depending on roof type, is explained. Both in service and laboratory test results demonstrate the cost effectiveness of the system. Further improvement of efficiency is envisaged with automatic flow control in the solar collector and hot water circuits.

  2. Dust storm, northern Mexico

    Science.gov (United States)

    1983-01-01

    This large dust storm along the left side of the photo, covers a large portion of the state of Coahuila, Mexico (27.5N, 102.0E). The look angle of this oblique photo is from the south to the north. In the foreground is the Sierra Madre Oriental in the states Coahuila and Nuevo Leon with the Rio Grande River, Amistad Reservoir and Texas in the background.

  3. Numerical and experimental investigation on a new type of compound parabolic concentrator solar collector

    International Nuclear Information System (INIS)

    Zheng, Wandong; Yang, Lin; Zhang, Huan; You, Shijun; Zhu, Chunguang

    2016-01-01

    Highlights: • A serpentine compound parabolic concentrator solar collector is proposed. • A mathematical model for the new collector is developed and verified by experiments. • The thermal efficiency of the collector can be up to 60.5% during the experiments. • The effects of key parameters on the thermal performance are mathematically studied. - Abstract: In order to improve the thermal efficiency, reduce the heat losses and achieve high freezing resistance of the solar device for space heating in cold regions, a new type of serpentine compound parabolic concentrator solar collector is presented in this paper, which is a combination of a compound parabolic concentrator solar collector and a flat plate solar collector. A detailed mathematical model for the new collector based on the analysis of heat transfer is developed and then solved by the software tool Matlab. The numerical results are compared with the experimental data and the maximum deviation is 8.07%, which shows a good agreement with each other. The experimental results show that the thermal efficiency of the collector can be as high as 60.5%. The model is used to predict the thermal performance of the new collector. The effects of structure and operating parameters on the thermal performance are mathematically discussed. The numerical and experimental results show that the new collector is more suitable to provide low temperature hot water for space heating in cold regions and the mathematical model will be much helpful in the designing and optimizing of the solar collectors.

  4. Wind load design methods for ground-based heliostats and parabolic dish collectors

    Energy Technology Data Exchange (ETDEWEB)

    Peterka, J A; Derickson, R G [Colorado State Univ., Fort Collins, CO (United States). Fluid Dynamics and Diffusion Lab.

    1992-09-01

    The purpose of this design method is to define wind loads on flat heliostat and parabolic dish collectors in a simplified form. Wind loads are defined for both mean and peak loads accounting for the protective influence of upwind collectors, wind protective fences, or other wind-blockage elements. The method used to define wind loads was to generalize wind load data obtained during tests on model collectors, heliostats or parabolic dishes, placed in a modeled atmospheric wind in a boundary-layer wind-tunnel at Colorado State University. For both heliostats and parabolic dishes, loads are reported for solitary collectors and for collectors as elements of a field. All collectors were solid with negligible porosity; thus the effects of porosity in the collectors is not addressed.

  5. Dust acoustic shock wave at high dust density

    International Nuclear Information System (INIS)

    Ghosh, Samiran; Sarkar, Susmita; Khan, Manoranjan; Avinash, K.; Gupta, M. R.

    2003-01-01

    Dust acoustic (DA) shock wave at high dust density, i.e., the dust electroacoustic (DEA) or dust Coulomb (DC) shock wave has been investigated incorporating the nonadiabatic dust charge variation. The nonlinear DEA (DC) shock wave is seen to be governed by the Korteweg-de Vries Burger equation, in which the Burger term is proportional to the nonadiabaticity generated dissipation. It is seen that the shock strength decreases but after reaching minimum, it increases as the dust space charge density |q d n d | increases and the shock strength of DA wave is greater than that of DEA (DC) wave. Moreover the DEA (DC) shock width increases appreciably with increase mass m i of the ion component of the dusty plasma but for DA shock wave the effect is weak

  6. Dust, Climate, and Human Health

    Science.gov (United States)

    Maynard, Nancy G.

    2003-01-01

    Air pollution from both natural and anthropogenic causes is considered to be one of the most serious world-wide environment-related health problems, and is expected to become worse with changes in the global climate. Dust storms from the atmospheric transport of desert soil dust that has been lifted and carried by the winds - often over significant distances - have become an increasingly important emerging air quality issue for many populations. Recent studies have shown that the dust storms can cause significant health impacts from the dust itself as well as the accompanying pollutants, pesticides, metals, salt, plant debris, and other inorganic and organic materials, including viable microorganisms (bacteria, viruses and fungi). For example, thousands of tons of Asian desert sediments, some containing pesticides and herbicides from farming regions, are commonly transported into the Arctic during dust storm events. These chemicals have been identified in animal and human tissues among Arctic indigenous populations. Millions of tons of airborne desert dust are being tracked by satellite imagery, which clearly shows the magnitude as well as the temporal and spatial variability of dust storms across the "dust belt" regions of North Africa, the Middle East, and China. This paper summarizes the most recent findings on the effects of airborne desert dust on human health as well as potential climate influences on dust and health.

  7. Parameterizing the interstellar dust temperature

    Science.gov (United States)

    Hocuk, S.; Szűcs, L.; Caselli, P.; Cazaux, S.; Spaans, M.; Esplugues, G. B.

    2017-08-01

    The temperature of interstellar dust particles is of great importance to astronomers. It plays a crucial role in the thermodynamics of interstellar clouds, because of the gas-dust collisional coupling. It is also a key parameter in astrochemical studies that governs the rate at which molecules form on dust. In 3D (magneto)hydrodynamic simulations often a simple expression for the dust temperature is adopted, because of computational constraints, while astrochemical modelers tend to keep the dust temperature constant over a large range of parameter space. Our aim is to provide an easy-to-use parametric expression for the dust temperature as a function of visual extinction (AV) and to shed light on the critical dependencies of the dust temperature on the grain composition. We obtain an expression for the dust temperature by semi-analytically solving the dust thermal balance for different types of grains and compare to a collection of recent observational measurements. We also explore the effect of ices on the dust temperature. Our results show that a mixed carbonaceous-silicate type dust with a high carbon volume fraction matches the observations best. We find that ice formation allows the dust to be warmer by up to 15% at high optical depths (AV> 20 mag) in the interstellar medium. Our parametric expression for the dust temperature is presented as Td = [ 11 + 5.7 × tanh(0.61 - log 10(AV) ]χuv1/5.9, where χuv is in units of the Draine (1978, ApJS, 36, 595) UV field.

  8. Evaluation of tube to collector connection by hydraulic expansion method in PGV-1000 steam generators

    International Nuclear Information System (INIS)

    Dashti, H.G.; Hashemi, B.; Jahromi, S.A.

    2011-01-01

    Research highlights: → The produced residual stresses in the collector body due to hydraulic expansion method have been compared with explosive method. → The residual stresses were obtained using two methods of FEM and strain gauging tests. → The effect of clearance between tube and collector on the residual stresses was investigated. → The contact stresses between the tube and collector interface were modeled and the required connection strength between tube and collector is estimated based on ASME rules and compared with FE results. - Abstract: Investigations on steam generators failure due to cracking in collector ligaments at perforated parts determined that connection process of the tubes to collector could be one of the main breakdown causes. The stability and strength of tube to collector joint is dependent to the geometry of tube and collector, the joining process and the operational conditions. In this research hydraulic expansion method has been considered as connection method of tube to collector. The Finite Element Method (FEM) was used to simulate the hydraulic expansion process and determine stress condition of the joints. The contact stresses between the tube and collector interface were modeled using contact elements of ANSYS program. Furthermore, the effect of clearance between tube and collector on the residual stresses around of joints was investigated. Some specimens from collector and tube materials were tested at various temperatures and their results were used at rate-independent multi-linear Mises plasticity model for FE analysis. Required connection strength between tube and collector is estimated based on ASME rules and compared with FE results. The results show that the residual tensile stresses could be greatly increased by decreasing of initial clearance. The highest value of residual stresses was observed around of collector holes nevertheless it was considerably lesser than obtained residual stresses in explosive method. The

  9. Optimal design of orientation of PV/T collector with reflectors

    International Nuclear Information System (INIS)

    Kostic, Lj.T.; Pavlovic, T.M.; Pavlovic, Z.T.

    2010-01-01

    Hybrid conversion of solar radiation implies simultaneous solar radiation conversion into thermal and electrical energy in the PV/Thermal collector. In order to get more thermal and electrical energy, flat solar radiation reflectors have been mounted on PV/T collector. To obtain higher solar radiation intensity on PV/T collector, position of reflectors has been changed and optimal position of reflectors has been determined by both experimental measurements and numerical calculation so as to obtain maximal concentration of solar radiation intensity. The calculated values have been found to be in good agreement with the measured ones, both yielding the optimal position of the flat reflector to be the lowest (5 o ) in December and the highest (38 o ) in June. In this paper, the thermal and electrical efficiency of PV/T collector without reflectors and with reflectors in optimal position have been calculated. Using these results, the total efficiency and energy-saving efficiency of PV/T collector have been determined. Energy-saving efficiency for PV/T collector without reflectors is 60.1%, which is above the conventional solar thermal collector, whereas the energy-saving efficiency for PV/T collector with reflectors in optimal position is 46.7%, which is almost equal to the values for conventional solar thermal collector. Though the energy-saving efficiency of PV/T collector decreases slightly with the solar radiation intensity concentration factor, i.e. the thermal and electrical efficiency of PV/T collector with reflectors are lower than those of PV/T collector without reflectors, the total thermal and electrical energy generated by PV/T collector with reflectors in optimal position are significantly higher than total thermal and electrical energy generated by PV/T collector without reflectors.

  10. Evaluation of Surface Slope Irregularity in Linear Parabolic Solar Collectors

    Directory of Open Access Journals (Sweden)

    F. Francini

    2012-01-01

    Full Text Available The paper describes a methodology, very simple in its application, for measuring surface irregularities of linear parabolic collectors. This technique was principally developed to be applied in cases where it is difficult to use cumbersome instruments and to facilitate logistic management. The instruments to be employed are a digital camera and a grating. If the reflector surface is defective, the image of the grating, reflected on the solar collector, appears distorted. Analyzing the reflected image, we can obtain the local slope of the defective surface. These profilometric tests are useful to identify and monitor the mirror portions under mechanical stress and to estimate the losses caused by the light rays deflected outside the absorber.

  11. IMPACT OF SOLAR RADIATION CHANGE ON THE COLLECTOR EFFICIENTLY

    Directory of Open Access Journals (Sweden)

    Danuta Proszak-Miąsik

    2017-01-01

    Full Text Available In October 2014 in a building of Rzeszow University of Technology, a series of measurements was taken to calculate the parameters of a solar system with a flat collector, as installed on the roof of the building. The following parameters were obtained: the value of solar radiation intensity, the temperature of external air, the temperature on the collector, the temperature of water in the tank and the temperature of glycol on the supply and return lines. On the basis of the data received, charts were made to visually present how changes of solar radiation intensity affected parameters of the system. The study was conducted in autumn when the intensity of solar radiation decreases, compared with summer months. The publication aims to show that the solar system brings energy gains in periods of transition, and the instantaneous intensity of solar radiation are comparable to those in the summer.

  12. The MAFF dry cloth collector programme for monitoring airborne radioactivity

    International Nuclear Information System (INIS)

    McHugh, J.O.; Smith, B.D.; Hunt, G.J.; Thomas, R.E.G.

    1986-01-01

    The history of the MAFF airborne radioactivity monitoring programme and its current operation using dry cloth collectors are described. The detection system has become well established as a sensitive indicator of airborne radioactivity. Details of collector materials, deployment around the major UK nuclear establishments and procedures for radiometric analysis of cloths are given. Typical results for the period 1980-82 show that at most sites only nuclear weapons fallout was detected. The systems's usefulness is exemplified by its response to the release of I-131 from Sellafield in 1981; this release was of negligible radiological significance but was easily detected. The response of dry cloths to various sources of atmospheric radioactivity and factors affecting collection efficiency are discussed. (author)

  13. Design optimization studies for nonimaging concentrating solar collector tubes

    Science.gov (United States)

    Winston, R.; Ogallagher, J. J.

    1983-09-01

    The Integrated Stationary Evacuated Concentrator or ISEC solar collector panel which achieved the best high temperature performance ever measured with a stationary collector was examined. A development effort review and optimize the initial proof of concept design was completed. Changes in the optical design to improve the angular response function and increase the optical efficiency were determined. A recommended profile design with a concentration ratio of 1.55x and an acceptance angle of + - 35(0) was identified. Two alternative panel/module configurations are recommended based on the preferred double ended flow through design. Parasitic thermal and pumping losses show to be reducible to acceptable levels, and two passive approaches to the problem of ensuring stagnation survival are identified.

  14. Method for making a high current fiber brush collector

    Science.gov (United States)

    Scuro, S. J.

    1986-05-01

    An axial-type homopolar motor having high density, high current fiber brush collectors affording efficient, low contact resistance and low operating temperatures is discussed. The collectors include a ring of concentric row of brushes in equally spaced beveled holes soldered in place using a fixture for heating the ring to just below the solder melting point at a soldering iron for the local application of additional heat at each brush. Prior to soldering, an oxide film is formed on the surfaces of the brushes and ring, and the bevels are burnished to form a wetting surface. Flux applied with the solder at each bevel removes to an effective soldering depth the oxide film on the brushes and the holes.

  15. Bilinear reduced order approximate model of parabolic distributed solar collectors

    KAUST Repository

    Elmetennani, Shahrazed

    2015-07-01

    This paper proposes a novel, low dimensional and accurate approximate model for the distributed parabolic solar collector, by means of a modified gaussian interpolation along the spatial domain. The proposed reduced model, taking the form of a low dimensional bilinear state representation, enables the reproduction of the heat transfer dynamics along the collector tube for system analysis. Moreover, presented as a reduced order bilinear state space model, the well established control theory for this class of systems can be applied. The approximation efficiency has been proven by several simulation tests, which have been performed considering parameters of the Acurex field with real external working conditions. Model accuracy has been evaluated by comparison to the analytical solution of the hyperbolic distributed model and its semi discretized approximation highlighting the benefits of using the proposed numerical scheme. Furthermore, model sensitivity to the different parameters of the gaussian interpolation has been studied.

  16. Water heating solar system using collector with polycarbonate absorber surface

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Luiz Guilherme Meira de; Sodre, Dilton; Cavalcanti, Eduardo Jose Cidade; Souza, Luiz Guilherme Vieira Meira de; Mendes, Jose Ubiragi de Lima [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)], e-mails: lguilherme@dem.ufrn.br, diltonsodre@ifba.edu.br, ubiragi@ct.ufrn.br

    2010-07-01

    It is presented s solar collector to be used in a heating water for bath system, whose main characteristics are low cost and easy fabrication and assembly processes. The collector absorber surface consists of a polycarbonate plate with an area of 1.5 m{sup 2}. The water inlet and outlet are made of PVC 50mm, and were coupled to a 6mm thick polycarbonate plate using fiberglass resin. A 200 liters thermal reservoir will be used. This reservoir is also alternative. The absorber heating system works under thermo-siphon regimen. Thermal parameters will be evaluated to prove the feasibility of the studied solar heating system to obtain bath water for a four people family. (author)

  17. Thermal advantage of tracking solar collectors under Danish weather conditions

    DEFF Research Database (Denmark)

    Andersen, Elsa; Dragsted, Janne; Furbo, Simon

    2010-01-01

    Theoretical investigations have been carried out with the aim to elucidate the thermal advantage of tracking solar collectors for different weather conditions in Kgs. Lyngby, Denmark (55.8°N), and for the weather conditions in Sisimiut, Greenland (66.9°N), just north of the arctic circle....... The investigations are based on calculations with a newly developed program. Measured weather data from a solar radiation measurement station at Technical University of Denmark in Kgs. Lyngby Denmark in the period 1990 to 2002 and the Danish Design Reference Year, DRY data file are used in the investigations....... The weather data used for Sisimiut are based on a Test Reference Year, TRY weather data file. The thermal advantages of different tracking strategies is investigated for two flat plate solar collectors with different efficiencies, operated at different temperature levels. The investigations show...

  18. A study on the optimal design of a cyclone system for vacuum cleaner with the consideration of house dust

    International Nuclear Information System (INIS)

    Ha, Gun Ho; Kim, Eung Dal; Kim, Young Soo; Lee, Jae Keun; Ahn, Young Chull; Kim, Dong Gyu

    2011-01-01

    Cyclone, a type of particle collector widely used in the field of ambient sampling and industrial particulate control, is the principal type of gas-solids separator that use a centrifugal force. The goal of this study is to transform conventional cyclone into a new type of cyclone that can be used for the household vacuum cleaners. To meet the goal, first, the analysis about local environment and dust is carried out. Second, it must have enough high-efficiency not to reduce suction power due to clogging of exhaust filter unit. Two single cyclones with central-hopper-dust-outlet and side-wall-dust-outlet and a twin cyclone are designed and fabricated to evaluate, and compare, their dust collection efficiencies and pressure drops. The measurements of separation efficiency for dust by using DMT test dust type 08 are carried out. House dust experiment is additionally performed to check the local matters applicability such as tissue papers, fur and hairs. The collection efficiency of the twin cyclone is found to be 3-6% greater than those of two single cyclones with the same body diameter, inlet and inner cylinder diameter. Twin cyclone with a large body diameter, a small inner cylinder diameter, a short inner cylinder, a narrow inlet has high separation efficiency. This result indicates the possibility of achieving higher collection efficiencies with a twin cyclone

  19. A cyclic distributed garbage collector for network objects

    OpenAIRE

    Rodrigues, Helena; Jones, Richard

    1996-01-01

    This paper presents an algorithm for distributed garbage collection and outlines its implementation within the Network Objects system. The algorithm is based on a reference listing scheme, which is augmented by partial tracing in order to collect distributed garbage cycles. Processes may be dynamically organised into groups, according to appropriate heuristics, to reclaim distributed garbage cycles. The algorithm places no overhead on local collectors and suspends local mutators only briefly....

  20. Theoretical Study of the Compound Parabolic Trough Solar Collector

    OpenAIRE

    Dr. Subhi S. Mahammed; Dr. Hameed J. Khalaf; Tadahmun A. Yassen

    2012-01-01

    Theoretical design of compound parabolic trough solar collector (CPC) without tracking is presented in this work. The thermal efficiency is obtained by using FORTRAN 90 program. The thermal efficiency is between (60-67)% at mass flow rate between (0.02-0.03) kg/s at concentration ratio of (3.8) without need to tracking system.The total and diffused radiation is calculated for Tikrit city by using theoretical equations. Good agreement between present work and the previous work.

  1. Solar thermal collectors at design and technology activity days

    OpenAIRE

    Petrina, Darinka

    2016-01-01

    Thesis encompases usage of renewable resources of energy, especially solar energy, which is essential for our future. On one hand, certain ways of exploiting solar energy (with solar cells) have been well established and is included in the Design and technology curriculum, on the other hand however, solar thermal collectors have not been recognized enough in spite of their distribution, applicability and environmentally friendly technology. Consequently thesis emphasizes the usage of solar en...

  2. Thermal performance of evacuated tube heat pipe solar collector

    Science.gov (United States)

    Putra, Nandy; Kristian, M. R.; David, R.; Haliansyah, K.; Ariantara, Bambang

    2016-06-01

    The high fossil energy consumption not only causes the scarcity of energy but also raises problems of global warming. Increasing needs of fossil fuel could be reduced through the utilization of solar energy by using solar collectors. Indonesia has the abundant potential for solar energy, but non-renewable energy sources still dominate energy consumption. With heat pipe as passive heat transfer device, evacuated tube solar collector is expected to heat up water for industrial and home usage without external power supply needed to circulate water inside the solar collector. This research was conducted to determine the performance of heat pipe-based evacuated tube solar collector as solar water heater experimentally. The experiments were carried out using stainless steel screen mesh as a wick material, and water and Al2O3-water 0.1% nanofluid as working fluid, and applying inclination angles of 0°, 15°, 30°, and 45°. To analyze the heat absorbed and transferred by the prototype, water at 30°C was circulated through the condenser. A 150 Watt halogen lamp was used as sun simulator, and the prototype was covered by an insulation box to obtain a steady state condition with a minimum affection of ambient changes. Experimental results show that the usage of Al2O3-water 0.1% nanofluid at 30° inclination angle provides the highest thermal performance, which gives efficiency as high as 0.196 and thermal resistance as low as 5.32 °C/W. The use of nanofluid as working fluid enhances thermal performance due to high thermal conductivity of the working fluid. The increase of the inclination angle plays a role in the drainage of the condensate to the evaporator that leads to higher thermal performance until the optimal inclination angle is reached.

  3. Oil/gas collector/separator for underwater oil leaks

    International Nuclear Information System (INIS)

    Henning, C.D.

    1993-01-01

    An oil/gas collector/separator for underwater oil leaks is described comprising: a cylindrical tank; a hollow float member for supporting said tank in a substantially upright position; a skirt assembly secured to said hollow float member and extending in a direction away from said float member opposite said tank; means for removing oil from said tank; and means for removing gas from said tank

  4. Dust in H II regions

    International Nuclear Information System (INIS)

    Isobe, S.

    1977-01-01

    Several pieces of evidence indicate that H II regions may contain dust: 1) the continuum light scattered by dust grains (O'Dell and Hubbard, 1965), 2) thermal radiation from dust grains at infrared wavelengths (Ney and Allen, 1969), 3) the abnormal helium abundance in some H II regions (Peimbert and Costero, 1969), etc. Although observations of the scattered continuum suggest that the H II region cores may be dust-free, dust grains and gas must be well mixed in view of the infrared observations. This difficulty may be solved by introducing globules with sizes approximately 0.001 pc. These globules and the molecular clouds adjacent to H II regions are the main sources supplying dust to H II regions. (Auth.)

  5. Large Aperture Electrostatic Dust Detector

    International Nuclear Information System (INIS)

    Skinner, C.H.; Hensley, R.; Roquemore, A.L.

    2007-01-01

    Diagnosis and management of dust inventories generated in next-step magnetic fusion devices is necessary for their safe operation. A novel electrostatic dust detector, based on a fine grid of interlocking circuit traces biased to 30 or 50 v has been developed for the detection of dust particles on remote surfaces in air and vacuum environments. Impinging dust particles create a temporary short circuit and the resulting current pulse is recorded by counting electronics. Up to 90% of the particles are ejected from the grid or vaporized suggesting the device may be useful for controlling dust inventories. We report measurements of the sensitivity of a large area (5x5 cm) detector to microgram quantities of dust particles and review its applications to contemporary tokamaks and ITER.

  6. Style and quality of life of waste collectors

    Directory of Open Access Journals (Sweden)

    Flávia Mendes da Silva

    2017-12-01

    Full Text Available The study aimed to analyze the style and quality of life of waste collectors and, to compare its respective domains. A cross-sectional and analytical study, conducted with 43 waste collectors of an inner city in Minas Gerais state. We used a form containing socio-economical and demographic data, WHOQOL-Bref and the Estilo de Vida Fantástico – EVF (FANTASTIC Lifestyle Assessment - Brazilian version. The results showed that there was a significant association between the results from the WHOQOL-Bref and EVF (p<0.05, indicating that higher quality of life scores are associated with better lifestyles. Despite the adverse conditions inherent from work executed by the collectors and its external causes, like the weather, odor, weight, physical effort, and low salaries, there was a satisfactory assessment for questions composing quality of life and lifestyle. From the exposed, it was evident that the work, health, quality of life and lifestyle are related and determine the worker’s profile in their subjective life, as well as, in their work life.

  7. Optimized concentrating/passive tracking solar collector. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sterne, K E; Johnson, A L; Grotheer, R H

    1979-01-01

    A concentrating solar collector having about half the material cost of other collectors with similar performance is described. The selected design is a Compound Parabolic Concentrator (CPC) which concentrates solar energy throughout the year without requiring realignment. Output is a fluid heated to 100/sup 0/C with good efficiency. The optical design of the reflector surface was optimized, yielding a 2.0:1 concentration ratio with a 60/sup 0/C acceptance angle and a low profile. Double glazing was chosen consisting of a polyester film outer glazing and an inner glazing of glass tubes around the absorbers. The selectively coated steel absorber tubes are connected in series with flexible plastic tubing. Much development effort went into the materials for the reflector subassembly. A laminate of metalized plastic film over plaster was chosen for the reflective surface. The reflector is rigidized by attaching filled epoxy header plates at each end. Aluminum side rails and an insulating back complete the structure. The finished design resulted in a material cost of $21.40 per square meter in production quantities. Performance testing of a prototype produced a 50% initial efficiency rating. This is somewhat lower than expected, and is due to materials and processes used in the prototype for the outer glazing, reflective surface and absorber coating. However, the efficiency curve drops only slightly with increasing temperature differential, showing the inherent advantage of the concentrator over flat plate collectors.

  8. Humidification dehumidification desalination system using parabolic trough solar air collector

    International Nuclear Information System (INIS)

    Al-Sulaiman, Fahad A.; Zubair, M. Ifras; Atif, Maimoon; Gandhidasan, Palanichamy; Al-Dini, Salem A.; Antar, Mohamed A.

    2015-01-01

    This paper deals with a detailed thermodynamic analysis to assess the performance of an HDH system with an integrated parabolic trough solar collector (PTSC). The HDH system considered is an open air, open water, air heated system that uses a PTSC as an air heater. Two different configurations were considered of the HDH system. In the first configuration, the solar air heater was placed before the humidifier whereas in the second configuration the solar air heater was placed between the humidifier and the dehumidifier. The current study revealed that PTSCs are well suited for air heated HDH systems for high radiation location, such as Dhahran, Saudi Arabia. The comparison between the two HDH configurations demonstrates that the gained output ratio (GOR) of the first configuration is, on average, about 1.5 whereas for the second configuration the GOR increases up to an average value of 4.7. The study demonstrates that the HDH configuration with the air heater placed between the humidifier and the dehumidifier has a better performance and a higher productivity. - Highlights: • Thermodynamic analysis of an HDH system driven by a parabolic trough solar collector was conducted. • The first configuration reveals a GOR of 1.5 while the second configuration reveals a GOR of 4.7. • Effective heating of the HDH system was obtained through parabolic trough solar collector

  9. Hybrid solar collector using nonimaging optics and photovoltaic components

    Science.gov (United States)

    Winston, Roland; Yablonovitch, Eli; Jiang, Lun; Widyolar, Bennett K.; Abdelhamid, Mahmoud; Scranton, Gregg; Cygan, David; Kozlov, Alexandr

    2015-08-01

    The project team of University of California at Merced (UC-M), Gas Technology Institute, and Dr. Eli Yablonovitch of University of California at Berkeley developed a novel hybrid concentrated solar photovoltaic thermal (PV/T) collector using nonimaging optics and world record single-junction Gallium arsenide (GaAs) PV components integrated with particle laden gas as thermal transfer and storage media, to simultaneously generate electricity and high temperature dispatchable heat. The collector transforms a parabolic trough, commonly used in CSP plants, into an integrated spectrum-splitting device. This places a spectrum-sensitive topping element on a secondary reflector that is registered to the thermal collection loop. The secondary reflector transmits higher energy photons for PV topping while diverting the remaining lower energy photons to the thermal media, achieving temperatures of around 400°C even under partial utilization of the solar spectrum. The collector uses the spectral selectivity property of Gallium arsenide (GaAs) cells to maximize the exergy output of the system, resulting in an estimated exergy efficiency of 48%. The thermal media is composed of fine particles of high melting point material in an inert gas that increases heat transfer and effectively stores excess heat in hot particles for later on-demand use.

  10. The collector library. A training for the artistic 'taste'?

    Directory of Open Access Journals (Sweden)

    Dorit Raines

    2016-11-01

    Full Text Available The paper argues that art collectors leveraged their library as one of the formative places of artistic taste. Acquiring knowledge through books may have helped shaping one’s artistic judgment, usually a mix of both intellective and emotional processes. Based on the Venetian case study of 17th-18th centuries patrician libraries, the paper explores the works used by art collectors in order to increase their discernment and artistic judgment: emblem, hieroglyphic and exempla books served as database of both pictorial and textual symbols which helped decipher paintings’ symbols and scenes. The Venetian libraries’ inventories and catalogues reveal the existence of two distinct phenomena: the inclusion of generic emblem printed books (with rare manuscript exceptions in almost all surveyed libraries and the presence of rare and sometimes costly emblem books, specifically tailored to the collector’s field of interest in several libraries. Moreover, the more professional art collectors shared knowledge and titles in order to cut on expenses, relying on the fact that at least one copy was to be found in Venice.

  11. Experimental Comparison of Two Configurations of Hybrid Photovoltaic Thermal Collectors

    International Nuclear Information System (INIS)

    Khaled Toufeka; Mourad Haddadib; Ali Mkc

    2011-01-01

    The combination of a thermal collector and a photovoltaic module in a single system allows for increased efficiency of the total conversion of solar energy. A synergistic effect can be obtained in a structure combining these two devices in a judicious manner to those of thermal and photovoltaic system installed separately. Production of total energy from hybrid collector depends on the input (that is to say, the. energy of solar radiation, air temperature and wind speed) and output which is the electric production and the temperature of the system. Thin production also depends on the mode of heal extraction. In this paper, an experimental Study of two configurations of hybrid collectors is described. The configuration that the absorber is made by galvanized steel and in the second, the absorber is a copper serpentine. The advantages of the first configuration are mainly due to low cost and simplicity but the second configuration has the advantage of promoting the heat transfer between cells and fluid. (authors)

  12. Photoelectric charging of dust grains

    International Nuclear Information System (INIS)

    Ignatov, A. M.

    2009-01-01

    Photoemission from the surface of a dust grain in vacuum is considered. It is shown that the cutoff in the energy spectrum of emitted electrons leads to the formation of a steady-state electron cloud. The equation describing the distribution of the electric potential in the vicinity of a dust grain is solved numerically. The dust grain charge is found as a function of the grain size.

  13. Quantitative measurement of 222Rn in water by the activated charcoal passive collector method: 1. The effect of water in a collector

    International Nuclear Information System (INIS)

    Yoneda, Minoru; Inoue, Yoriteru; Yoshimoto, Keizo

    1994-01-01

    The activated charcoal passive collector method can be applied to measure the concentration of 222 Rn in river water. The 222 Rn collector is composed of dry activated charcoal sealed in a polyethylene bag. However, we found it very difficult to keep activated charcoal in a collector dry during the period the collector was left in a river. The degree of dampness and the time lapsed when activated charcoal became wet were thought to affect the quantity of 222 Rn collected. First, we studied the effect of some parameters in the activated charcoal passive collector method qualitatively in three experiments. We found that the quantity of 222 Rn collected in a collector was not so sensitive to the quantity of activated charcoal in the collector or the thickness of polyethylene film under the condition of wet activated charcoal, and that wet activated charcoal accumulated less 222 Rn than dry activated charcoal. We present some equations which could explain how much 222 Rn was collected in a collector when activated charcoal was submerged directly in water and when activated charcoal was packed in a polyethylene bag but completely wet. These equations were proved effective by being compared with the results of the other experiments. Finally, we recommended some conditions which proved useful when measuring at an actual river

  14. Dust in cosmic plasma environments

    International Nuclear Information System (INIS)

    Mendis, D.A.

    1979-01-01

    Cosmic dust is invariably immersed in a plasma and a radiative environment. Consequently, it is charged to some electrostatic potential which depends on the properties of the environment as well as the nature of the dust. This charging affects the physical and dynamical properties of the dust. In this paper the basic aspects of this dust-plasma interaction in several cosmic environments - including planetary magnetospheres, the heliosphere and the interstellar medium - are discussed. The physical and dynamical consequences of the interaction, as well as the pertinent observational evidence, are reviewed. Finally, the importance of the surface charge during the condensation process in plasma environments is stressed. (Auth.)

  15. Theoretical analysis to investigate thermal performance of co-axial heat pipe solar collector

    Energy Technology Data Exchange (ETDEWEB)

    Azad, E. [Iranian Research Organization for Science and Technology (IROST), Advanced Materials and Renewable Energy Department, Tehran (Iran, Islamic Republic of)

    2011-12-15

    The thermal performance of co-axial heat pipe solar collector which consist of a collector 15 co-axial heat pipes surrounded by a transparent envelope and which heat a fluid flowing through the condenser tubes have been predicted using heat transfer analytical methods. The analysis considers conductive and convective losses and energy transferred to a fluid flowing through the collector condenser tubes. The thermal performances of co-axial heat pipe solar collector is developed and are used to determine the collector efficiency, which is defined as the ratio of heat taken from the water flowing in the condenser tube and the solar radiation striking the collector absorber. The theoretical water outlet temperature and efficiency are compared with experimental results and it shows good agreement between them. The main advantage of this collector is that inclination of collector does not have influence on performance of co-axial heat pipe solar collector therefore it can be positioned at any angle from horizontal to vertical. In high building where the roof area is not enough the co-axial heat pipe solar collectors can be installed on the roof as well as wall of the building. The other advantage is each heat pipe can be topologically disconnected from the manifold. (orig.)

  16. Solar energy captured by a curved collector designed for architectural integration

    International Nuclear Information System (INIS)

    Rodríguez-Sánchez, D.; Belmonte, J.F.; Izquierdo-Barrientos, M.A.; Molina, A.E.; Rosengarten, G.; Almendros-Ibáñez, J.A.

    2014-01-01

    Highlights: • We present a new prototype of solar collector for architectural integration. • Equations of the solar radiation on a curved surface. • We compare the energy intercepted by the prototype with the energy intercepted by conventional collectors. • The prototype can be competitive compared with conventional collectors. - Abstract: In this paper we present a prototype for a new type of solar thermal collector designed for architectural integration. In this proposal, the conventional geometry of a flat solar thermal collector is changed to a curved geometry, to improve its visual impact when mounted on a building facade or roof. The mathematical equations for the beam and diffuse solar radiation received by a collector with this geometry are developed for two different orientations, horizontal and vertical. The performance of this curved prototype, in terms of solar radiation received, is compared with a conventional tilted-surface collector for different orientations in Madrid (Spain). The comparison is made for typical clear-sky days in winter and summer as well as for an entire year. The results demonstrate that the curved collector only receives between 12% and 25% less radiation than the conventional tilted-surface collectors when oriented horizontally, depending on the azimuth of the curved surface, although these percentages are reduced to approximately 50% when the collector is oriented vertically

  17. Theoretical analysis to investigate thermal performance of co-axial heat pipe solar collector

    Science.gov (United States)

    Azad, E.

    2011-12-01

    The thermal performance of co-axial heat pipe solar collector which consist of a collector 15 co-axial heat pipes surrounded by a transparent envelope and which heat a fluid flowing through the condenser tubes have been predicted using heat transfer analytical methods. The analysis considers conductive and convective losses and energy transferred to a fluid flowing through the collector condenser tubes. The thermal performances of co-axial heat pipe solar collector is developed and are used to determine the collector efficiency, which is defined as the ratio of heat taken from the water flowing in the condenser tube and the solar radiation striking the collector absorber. The theoretical water outlet temperature and efficiency are compared with experimental results and it shows good agreement between them. The main advantage of this collector is that inclination of collector does not have influence on performance of co-axial heat pipe solar collector therefore it can be positioned at any angle from horizontal to vertical. In high building where the roof area is not enough the co-axial heat pipe solar collectors can be installed on the roof as well as wall of the building. The other advantage is each heat pipe can be topologically disconnected from the manifold.

  18. Daily efficiency of flat-plate solar air collectors for grain drying

    Energy Technology Data Exchange (ETDEWEB)

    Ting, K.C.; Shove, G.C.

    1983-01-01

    Single cover flat-plate solar collectors incorporated into walls and roofs of farm buildings have been used to heat ambient air for low temperature grain drying systems. Large surface area and high airflow rate are common features of these collectors. The drying period may range from several days to several weeks. Therefore, a knowledge of the variations of the collectors' daily efficiencies with respect to their design parameters would be helpful in applying solar collectors to grain drying. The objective of this study was to develop a simpler means of direct calculation of a collector's daily efficiency based on its design parameters. Many factors, such as configuration of the collector, airflow rate, weather conditions, etc. will affect the performance of solar collectors. A large number of varied conditions need to be tested in order to investigate the effect of different parameters on the collector performance. To facilitate this investigation, a computer simulation model developed by Ting was used to calculate the daily efficiencies of collectors under different operating conditions. The computer model was verified by Morrison's experimental data. Based on the simulation results, a functional relationship was developed between the daily efficiencies of collectors and their design parameters.

  19. On the Influence of Collector Size on the Solar Chimneys Performance

    Directory of Open Access Journals (Sweden)

    Al-Azawiey Sundus S.

    2017-01-01

    Full Text Available Performance of solar chimney power plant system is highly influenced by the design geometries. The collector size is logically enhances the solar chimney performance, but the trend of enhancement is not yet investigated. In the present work, experimental and numerical investigations have been carried out to ascertain, in terms of qualitative and quantitative evaluation, the effect of the collector diameter. Daily thermal efficiency has been determined at four different collector diameter. Two different collector diameters, 3.0 and 6.0 m, have been investigated experimentally, and then scaled up, to 9.0 and 12.0 m, by numerical simulation using ANSYS-FLUENT®15 software. Results demonstrated that collector diameter has effectively influenced the system performance. Larger collector diameter imposed increase in the velocity, temperature and the daily average thermal efficiency of the system. From the experimental results, increasing the collector diameter from 3.0 to 6.0 m has increased the daily average thermal efficiency of the collector from 9.81 to 12.8. Simulation results at 800 W/m2 irradiation revealed that the velocity in the chimney have increased from 1.66 m/s at 3.0 m collector diameter to 2.34, 2.47 and 2.63 m/s for 6.0, 9.0 and 12.0 m collector diameters, respectively.

  20. Overall energy, exergy and carbon credit analysis by different type of hybrid photovoltaic thermal air collectors

    International Nuclear Information System (INIS)

    Agrawal, Sanjay; Tiwari, G.N.

    2013-01-01

    Highlights: ► Comparative study of PVT air collectors. ► CO 2 analysis of all type of PVT air collectors. ► Study of thermal energy, exergy gain and exergy efficiency. ► Exergy efficiency of unglazed hybrid PVT tiles air collector is most efficient. - Abstract: In this paper, comparative analysis of different type of photovoltaic thermal (PVT) air collector namely: (i) unglazed hybrid PVT tiles, (ii) glazed hybrid PVT tiles and (iii) conventional hybrid PVT air collectors have been carried out for the composite climate of Srinagar (India). The comparative study has been carried out in terms of overall thermal energy and exergy gain, exergy efficiency and carbon credit earned by different type of hybrid PVT air collectors. It has been observed that overall annual thermal energy and exergy gain of unglazed hybrid PVT tiles air collector is higher by 27% and 29.3% respectively as compared to glazed hybrid PVT tiles air collector and by 61% and 59.8% respectively as compared to conventional hybrid PVT air collector. It has also been observed that overall annual exergy efficiency of unglazed and glazed hybrid PVT tiles air collector is higher by 9.6% and 53.8% respectively as compared to conventional hybrid PVT air collector. On the basis of comparative study, it has been concluded that CO 2 emission reduction per annum on the basis of overall thermal energy gain of unglazed and glazed hybrid PVT tiles air collector is higher by 62.3% and 27.7% respectively as compared to conventional hybrid PVT air collector and on the basis of overall exergy gain it is 59.7% and 22.7%.

  1. Gravitational radiation from dust

    International Nuclear Information System (INIS)

    Isaacson, R.A.; Welling, J.S.; Winicour, J.

    1985-01-01

    A dust cloud is examined within the framework of the general relativistic characteristic initial value problem. Unique gravitational initial data are obtained by requiring that the space-time be quasi-Newtonian. Explicit calculations of metric and matter fields are presented, which include all post-Newtonian corrections necessary to discuss the major physical properties of null infinity. These results establish a curved space version of the Einstein quadrupole formula, in the form ''news function equals third time derivative of transverse quadrupole moment,'' for this system. However, these results imply that some weakened notion of asymptotic flatness is necessary for the description of quasi-Newtonian systems

  2. Dust coagulation in ISM

    Science.gov (United States)

    Chokshi, Arati; Tielens, Alexander G. G. M.; Hollenbach, David

    1989-01-01

    Coagulation is an important mechanism in the growth of interstellar and interplanetary dust particles. The microphysics of the coagulation process was theoretically analyzed as a function of the physical properties of the coagulating grains, i.e., their size, relative velocities, temperature, elastic properties, and the van der Waal interaction. Numerical calculations of collisions between linear chains provide the wave energy in individual particles and the spectrum of the mechanical vibrations set up in colliding particles. Sticking probabilities are then calculated using simple estimates for elastic deformation energies and for the attenuation of the wave energy due to absorption and scattering processes.

  3. Dust confinement and dust acoustic waves in a magnetized plasma

    Science.gov (United States)

    Piel, A.

    2005-10-01

    Systematic laboratory experiments on dust acoustic waves require the confinement of dust particles. Here we report on new experiments in a magnetized plasma region in front of an additional positively biased disk electrode in a background plasma which is generated in argon at 27MHz between a disk and grid electrode. The plasma diffuses through the grid along the magnetic field. The three-dimensional dust distribution is measured with a horizontal sheet of laser light and a CCD camera, which are mounted on a vertical translation stage. Depending on magnetic field and discharge current, cigar or donut-shaped dust clouds are generated, which tend to rotate about the magnetic field direction. Measurements with emissive probes show that the axial confinement of dust particles with diameters between 0.7-2 μm is achieved by a balance of ion-drag force and electric field force. Dust levitation and radial confinement is due to a strong radial electric field. Dust acoustic waves are destabilized by the ion flow or can be stimulated by a periodic bias on the disk electrode. The observed wave dispersion is compared with fluid and kinetic models of the dust acoustic wave.

  4. Gravimetric dust sampling for control purposes and occupational dust sampling.

    CSIR Research Space (South Africa)

    Unsted, AD

    1997-02-01

    Full Text Available Prior to the introduction of gravimetric dust sampling, konimeters had been used for dust sampling, which was largely for control purposes. Whether or not absolute results were achievable was not an issue since relative results were used to evaluate...

  5. Of data and dust

    CERN Multimedia

    Stephanie Hills

    2016-01-01

    The traditional image of an archive is one of dusty old boxes, books and papers. When your archive is digital, dust spells disaster. An innovative environmental sensor designed and built by a CERN IT specialist has become an essential element in the Laboratory’s data-preservation strategy.   The novel air particle monitoring sensor designed by CERN's Julien Leduc. CERN’s archive holds more than 130 petabytes of data from past and present high-energy physics experiments. Some of it is 40 years old, most of it needs to be kept forever, and all of it is held on tape cartridges (over 20,000 of them). The cartridges are held inside tape libraries with robotic arms that load them into tape drives where they can be read and written. Tape cartridges have many advantages over other data storage media, notably cost and long-term reliability, but topping the list of drawbacks is their vulnerability to contamination from airborne dust particles; a tiny piece of g...

  6. Radionuclides in house dust

    Energy Technology Data Exchange (ETDEWEB)

    Fry, F A; Green, N; Dodd, N J; Hammond, D J

    1985-04-01

    Discharges of radionuclides from the British Nuclear Fuel plc (BNFL) reprocessing plant at Sellafield in Cumbria have led to elevated concentrations radionuclides in the local environment. The major routes of exposure of the public are kept under review by the appropriate authorising Government departments and monitoring is carried out both by the departments and by BNFL itself. Recently, there has been increasing public concern about general environmental contamination resulting from the discharges and, in particular, about possible exposure of members of the public by routes not previously investigated in detail. One such postulated route of exposure that has attracted the interest of the public, the press and Parliament arises from the presence of radionuclides within houses. In view of this obvious and widespread concern, the Board has undertaken a sampling programme in a few communities in Cumbria to assess the radiological significance of this source of exposure. From the results of our study, we conclude that, although radionuclides originating rom the BNFL site can be detected in house dust, this source of contamination is a negligible route of exposure for members of the public in West Cumbria. This report presents the results of the Board's study of house dust in twenty homes in Cumbria during the spring and summer of 1984. A more intensive investigation is being carried out by Imperial College. (author)

  7. Health hazards of cement dust

    International Nuclear Information System (INIS)

    Meo, Sultan A.

    2004-01-01

    ven in the 21st century, millions of people are working daily in a dusty environment. They are exposed to different types of health hazards such as fume, gases and dust, which are risk factors in developing occupational disease. Cement industry is involved in the development of structure of this advanced and modern world but generates dust during its production. Cement dust causes lung function impairment, chronic obstructive lung disease, restrictive lung disease, pneumoconiosis and carcinoma of the lungs, stomach and colon. Other studies have shown that cement dust may enter into the systemic circulation and thereby reach the essentially all the organs of body and affects the different tissues including heart, liver, spleen, bone, muscles and hairs and ultimately affecting their micro-structure and physiological performance. Most of the studies have been previously attempted to evaluate the effects of cement dust exposure on the basis of spirometry or radiology, or both. However, collective effort describing the general effects of cement dust on different organ and systems in humans or animals, or both has not been published. Therefore, the aim of this review is to gather the potential toxic effects of cement dust and to minimize the health risks in cement mill workers by providing them with information regarding the hazards of cement dust. (author)

  8. Dust forecasting system in JMA

    International Nuclear Information System (INIS)

    Mikami, M; Tanaka, T Y; Maki, T

    2009-01-01

    JMAs dust forecasting information, which is based on a GCM dust model, is presented through the JMA website coupled with nowcast information. The website was updated recently and JMA and MOE joint 'KOSA' website was open from April 2008. Data assimilation technique will be introduced for improvement of the 'KOSA' information.

  9. A numerical model to evaluate the flow distribution in a large solar collector field

    DEFF Research Database (Denmark)

    Bava, Federico; Dragsted, Janne; Furbo, Simon

    2017-01-01

    This study presents a numerical model to evaluate the flow distribution in a large solar collector field, with solar collectors connected both in series and in parallel. The boundary conditions of the systems, such as flow rate, temperature, fluid type and layout of the collector field can...... be easily changed in the model. The model was developed in Matlab and the calculated pressure drop and flow distribution were compared with measurements from a solar collector field. A good agreement between model and measurements was found. The model was then used to study the flow distribution...... in different conditions. Balancing valves proved to be an effective way to achieve uniform flow distribution also in conditions different from those for which the valves were regulated. For small solar collector fields with limited number of collector rows connected in parallel, balancing valves...

  10. Flow distribution in a solar collector panel with horizontally inclined absorber strips

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    2007-01-01

    The objective of this work is to theoretically and experimentally investigate the flow and temperature distribution in a solar collector panel with an absorber consisting of horizontally inclined strips. Fluid flow and heat transfer in the collector panel are studied by means of computational fluid...... dynamics (CFD) calculations. Further, experimental investigations of a 12.5 m(2) solar collector panel with 16 parallel connected horizontal fins are carried out. The flow distribution through the absorber is evaluated by means of temperature measurements on the backside of the absorber tubes. The measured...... rate, properties of solar collector fluid, solar collector fluid inlet temperature and collector tilt angle are shown. The flow distribution through the absorber fins is uniform if high flow rates are used. By decreased flow rate and decreased content of glycol in the glycol/water mixture used as solar...

  11. Dust in flowing magnetized plasma

    International Nuclear Information System (INIS)

    Pandey, Birendra P.; Samarian, Alex A.; Vladimirov, Sergey V.

    2009-01-01

    Plasma flows occur in almost every laboratory device and interactions of flowing plasmas with near-wall impurities and/or dust significantly affects the efficiency and lifetime of such devices. The charged dust inside the magnetized flowing plasma moves primarily under the influence of the plasma drag and electric forces. Here, the charge on the dust, plasma potential, and plasma density are calculated self-consistently. The electrons are assumed non-Boltzmannian and the effect of electron magnetization and electron-atom collisions on the dust charge is calculated in a self-consistent fashion. For various plasma magnetization parameters viz. the ratio of the electron and ion cyclotron frequencies to their respective collision frequencies, plasma-atom and ionization frequencies, the evolution of the plasma potential and density in the flow region is investigated. The variation of the dust charge profile is shown to be a sensitive function of plasma parameters. (author)

  12. Ray tracing for optimization of compound parabolic concentrators for solar collectors of enclosed design

    OpenAIRE

    YURCHENKO, VLADIMIR; YURCHENKO, EDUARD; ÇİYDEM, MEHMET; TOTUK, ONAT

    2015-01-01

    We present our developments in computer simulations and optimization of compound parabolic concentrators (CPCs) for solar heat collectors. Issues of both the optical and thermal optimization of CPC collectors of enclosed design are discussed. Ray tracing results for a CPC with a V-shaped absorber are presented. A range of optimal values for the apex angle of a V-shaped absorber is proposed for a CPC collector of typical design.

  13. A thin-collector Bayard-Alpert gauge for 10-12 Torr vacuum

    International Nuclear Information System (INIS)

    Hseuh, H.C.; Lanni, C.

    1986-01-01

    The changes in the sensitivity (S) and the equivalent X-ray limit (P/sub x/) of several Bayard-Alpert gauges (BAGs) were studied when the size of the collectors was reduced from 125 μ to 50 μ and when different mounting envelopes were used. Based on this study, 400 custom BAGs with 50 μ collector were purchased from a vendor. The S and the P/sub x/ of these thin-collector BAGs were also measured

  14. Semi-solid electrode cell having a porous current collector and methods of manufacture

    Science.gov (United States)

    Chiang, Yet-Ming; Carter, William Craig; Cross, III, James C.; Bazzarella, Ricardo; Ota, Naoki

    2017-11-21

    An electrochemical cell includes an anode, a semi-solid cathode, and a separator disposed therebetween. The semi-solid cathode includes a porous current collector and a suspension of an active material and a conductive material disposed in a non-aqueous liquid electrolyte. The porous current collector is at least partially disposed within the suspension such that the suspension substantially encapsulates the porous current collector.

  15. Effect of Collector Aspect Ratio on the Thermal Performance of Wavy Finned Absorber Solar Air Heater

    OpenAIRE

    Abhishek Priyam; Prabha Chand

    2016-01-01

    A theoretical investigation on the effect of collector aspect ratio on the thermal performance of wavy finned absorber solar air heaters has been performed. For the constant collector area, the various performance parameters have been calculated for plane and wavy finned solar air heaters. It has been found that the performance of wavy finned solar air heater improved with the increase in the collector aspect ratio. The performance of wavy finned solar air heater has been found 30 percent hig...

  16. A heat pipe solar collector system for winter heating in Zhengzhou city, China

    Directory of Open Access Journals (Sweden)

    Zheng Hui-Fan

    2017-01-01

    Full Text Available A heat pipe solar collector system for winter heating is investigated both experimentally and theoretically. The hourly heat collecting capacity, water temperature and contribution rate of solar collector system based on Zhengzhou city typical sunshine are calculated. The study reveals that the heat collecting capacity and water temperature increases initially and then decreases, and the solar collector system can provide from 40% to 78% heating load for a 200 m2 villa with in Zhengzhou city from November to March.

  17. Refractive integrated nonimaging solar collectors design and analysis of a novel solar-daylighting-technology

    OpenAIRE

    Pelegrini, Alexandre Vieira

    2009-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. A novel and original category of low-cost static solar-daylighting-collectors named Keywo solar energy, solar collectors, daylighting systems, nonimaging optics, Refractive Integrated Nonimaging Solar Collectors (RINSC) has been designed and thoroughly tested. The RINSC category is based on nonimaging optics and integrates several optical elements, such as prismatic arrays and light guides, i...

  18. Energy, economic and environmental analysis of metal oxides nanofluid for flat-plate solar collector

    International Nuclear Information System (INIS)

    Faizal, M.; Saidur, R.; Mekhilef, S.; Alim, M.A.

    2013-01-01

    Highlights: • By using nanofluid, smaller and compact solar collector can be produced. • The average value of 220 MJ embodied energy can be saved. • The payback period of using nanofluid solar collector is around 2.4 years. • Around 170 kg less CO 2 emissions in average for nanofluid solar collector. • Environmental damage cost is lower with the nanofluid based solar collector. - Abstract: For a solar thermal system, increasing the heat transfer area can increase the output temperature of the system. However, this approach leads to a bigger and bulkier collector. It will then increase the cost and energy needed to manufacture the solar collector. This study is carried out to estimate the potential to design a smaller solar collector that can produce the same desired output temperature. This is possible by using nanofluid as working fluid. By using numerical methods and data from literatures, efficiency, size reduction, cost and embodied energy savings are calculated for various nanofluids. From the study, it was estimated that 10,239 kg, 8625 kg, 8857 kg and 8618 kg total weight for 1000 units of solar collectors can be saved for CuO, SiO 2 , TiO 2 and Al 2 O 3 nanofluid respectively. The average value of 220 MJ embodied energy can be saved for each collector, 2.4 years payback period can be achieved and around 170 kg less CO 2 emissions in average can be offset for the nanofluid based solar collector compared to a conventional solar collector. Finally, the environmental damage cost can also be reduced with the nanofluid based solar collector

  19. Solar collector performance evaluated outdoors at NASA-Lewis Research Center

    Science.gov (United States)

    Vernon, R. W.

    1974-01-01

    The study of solar reflector performance reported is related to a project in which solar collectors are to be provided for the solar heating and cooling system of an office building at NASA's Langley Research Center. The solar collector makes use of a liquid consisting of 50% ethylene glycol and 50% water. A conventional air-liquid heat exchanger is employed. Collector performance and solar insolation data are recorded along with air temperature, wind speed and direction, and relative humidity.

  20. Converting PETAL, the 25m solar collector, into an astronimcal research facility

    Science.gov (United States)

    Ribak, Erez N.; Laor, Ari; Faiman, David; Biyukov, Sergy; Brosch, Noah

    2003-02-01

    We propose to modify the solar collector PETAL (Photon Energy Transformation &Astrophysics Laboratory) for astronomy. The mirror is a segmented parabolic dish collector, which has a relatively poor imaging quality. The conversion can be done by either of two principal methods: (1) phasing the surface of the collector itself or significant sections thereof; (2) transforming the structure into an optical interferometer by mounting small telescopes around its rim, and using fiber optics to combine the light at a common focus.

  1. Dust in protoplanetary disks: observations*

    Directory of Open Access Journals (Sweden)

    Waters L.B.F.M.

    2015-01-01

    Full Text Available Solid particles, usually referred to as dust, are a crucial component of interstellar matter and of planet forming disks surrounding young stars. Despite the relatively small mass fraction of ≈1% (in the solar neighborhood of our galaxy; this number may differ substantially in other galaxies that interstellar grains represent of the total mass budget of interstellar matter, dust grains play an important role in the physics and chemistry of interstellar matter. This is because of the opacity dust grains at short (optical, UV wavelengths, and the surface they provide for chemical reactions. In addition, dust grains play a pivotal role in the planet formation process: in the core accretion model of planet formation, the growth of dust grains from the microscopic size range to large, cm-sized or larger grains is the first step in planet formation. Not only the grain size distribution is affected by planet formation. Chemical and physical processes alter the structure and chemical composition of dust grains as they enter the protoplanetary disk and move closer to the forming star. Therefore, a lot can be learned about the way stars and planets are formed by observations of dust in protoplanetary disks. Ideally, one would like to measure the dust mass, the grain size distribution, grain structure (porosity, fluffiness, the chemical composition, and all of these as a function of position in the disk. Fortunately, several observational diagnostics are available to derive constrains on these quantities. In combination with rapidly increasing quality of the data (spatial and spectral resolution, a lot of progress has been made in our understanding of dust evolution in protoplanetary disks. An excellent review of dust evolution in protoplanetary disks can be found in Testi et al. (2014.

  2. Grid collector: An event catalog with automated file management

    International Nuclear Information System (INIS)

    Wu, Kesheng; Zhang, Wei-Ming; Sim, Alexander; Gu, Junmin; Shoshani, Arie

    2003-01-01

    High Energy Nuclear Physics (HENP) experiments such as STAR at BNL and ATLAS at CERN produce large amounts of data that are stored as files on mass storage systems in computer centers. In these files, the basic unit of data is an event. Analysis is typically performed on a selected set of events. The files containing these events have to be located, copied from mass storage systems to disks before analysis, and removed when no longer needed. These file management tasks are tedious and time consuming. Typically, all events contained in the files are read into memory before a selection is made. Since the time to read the events dominate the overall execution time, reading the unwanted event needlessly increases the analysis time. The Grid Collector is a set of software modules that works together to address these two issues. It automates the file management tasks and provides ''direct'' access to the selected events for analyses. It is currently integrated with the STAR analysis framework. The users can select events based on tags, such as, ''production date between March 10 and 20, and the number of charged tracks > 100.'' The Grid Collector locates the files containing relevant events, transfers the files across the Grid if necessary, and delivers the events to the analysis code through the familiar iterators. There has been some research efforts to address the file management issues, the Grid Collector is unique in that it addresses the event access issue together with the file management issues. This makes it more useful to a large variety of users

  3. Grid collector: An event catalog with automated file management

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kesheng; Zhang, Wei-Ming; Sim, Alexander; Gu, Junmin; Shoshani, Arie

    2003-10-17

    High Energy Nuclear Physics (HENP) experiments such as STAR at BNL and ATLAS at CERN produce large amounts of data that are stored as files on mass storage systems in computer centers. In these files, the basic unit of data is an event. Analysis is typically performed on a selected set of events. The files containing these events have to be located, copied from mass storage systems to disks before analysis, and removed when no longer needed. These file management tasks are tedious and time consuming. Typically, all events contained in the files are read into memory before a selection is made. Since the time to read the events dominate the overall execution time, reading the unwanted event needlessly increases the analysis time. The Grid Collector is a set of software modules that works together to address these two issues. It automates the file management tasks and provides ''direct'' access to the selected events for analyses. It is currently integrated with the STAR analysis framework. The users can select events based on tags, such as, ''production date between March 10 and 20, and the number of charged tracks > 100.'' The Grid Collector locates the files containing relevant events, transfers the files across the Grid if necessary, and delivers the events to the analysis code through the familiar iterators. There has been some research efforts to address the file management issues, the Grid Collector is unique in that it addresses the event access issue together with the file management issues. This makes it more useful to a large variety of users.

  4. Experience with building integrated solar collectors; Erfaring med bygningsintegrerte solfangere

    Energy Technology Data Exchange (ETDEWEB)

    Simonsen, Ingeborg; Time, Berit; Andresen, Inger

    2011-07-01

    The main objective of the research 'Zero Emission Buildings' ZEB is to develop products and solutions that provide buildings with zero greenhouse gas emissions associated with the production, operation and disposal. Can we make this happen must the building produce more energy than it needs to compensate for greenhouse gas emissions from the production of materials and the actual construction.To build up knowledge on experience with building integrated solar collectors in Norway, we have in this study made interviews with suppliers and manufacturers of solar collectors and some building owners. Since the focus is on climate shell, we have limited the study to include solar collectors to replace a part of the cladding or roofing. Construction upstairs roofing, outside facade or freestanding rack is not considered as building integrated in this context. The providers we have been in contact with appeals to slightly different parts of the market. This is reflected in the product's development, assembly and approach to the calculation of energy delivery. Overall, providers may offer a range of products suitable for both the professional and skilled carpenter, the interested 'man in the street' . The feedback we have received shows generally good experiences with the product and the installation. Because of the preliminary short operating periods of the investigated plants we have little data on energy supply from these plants. In summary, we can say that the knowledge and the products are available and it is up to use to use them.(Author)

  5. COAL DUST EMISSION PROBLEM

    Directory of Open Access Journals (Sweden)

    M. M. Biliaiev

    2016-12-01

    Full Text Available Purpose. The article aims to develop 2D numerical models for the prediction of atmospheric pollution during transportation of coal in the railway car, as well as the ways to protect the environment and the areas near to the mainline from the dust emission due to the air injection installation. Methodology. To solve this problem there were developed numerical models based on the use of the equations of motion of an inviscid incompressible fluid and mass transfer. For the numerical integration of the transport equation of the pollutant the implicit alternating-triangular difference scheme was used. For numerical integration of the 2D equation for the velocity potential the method of total approximation was used. The developed numerical models are the basis of established software package. On the basis of the constructed numerical models it was carried out a computational experiment to assess the level of air pollution when transporting bulk cargo by rail when the railway car has the air injection. Findings. 2D numerical models that belong to the class «diagnostic models» were developed. These models take into account the main physical factors affecting the process of dispersion of dust pollution in the atmosphere during transportation of bulk cargo. The developed numerical models make it possible to calculate the dust loss process, taking into account the use of the air injection of the car. They require a small cost of the computer time during practical realization at the low and medium power machines. There were submitted computational calculations to determine pollutant concentrations and the formation of the zone of pollution near the train with bulk cargo in «microscale» scale taking into account the air curtains. Originality. 2D numerical models taking into account the relevant factors influencing the process of dispersion of pollutants in the atmosphere, and the formation of the zone of pollution during transportation of bulk cargo by

  6. A new desalination system using a combination of heat pipe, evacuated tube and parabolic trough collector

    International Nuclear Information System (INIS)

    Jafari Mosleh, H.; Jahangiri Mamouri, S.; Shafii, M.B.; Hakim Sima, A.

    2015-01-01

    Highlights: • A new desalination uses a combination of heat pipe and parabolic trough collector. • A twin-glass evacuated tube is used to decrease the thermal losses from heat pipe. • Adding oil into the space between heat pipe and tube collector enhances the yield. • The yield and efficiency reach up to 0.933 kg/(m 2 h) and 65.2%, respectively. - Abstract: The solar collectors have been commonly used in desalination systems. Recent investigations show that the use of a linear parabolic trough collector in solar stills can improve the efficiency of a desalination system. In this work, a combination of a heat pipe and a twin-glass evacuated tube collector is utilized with a parabolic trough collector. Results show that the rate of production and efficiency can reach to 0.27 kg/(m 2 h) and 22.1% when aluminum conducting foils are used in the space between the heat pipe and the twin-glass evacuated tube collector to transfer heat from the tube collector to the heat pipe. When oil is used as a medium for the transfer of heat, filling the space between heat pipe and twin-glass evacuated tube collector, the production and efficiency can increase to 0.933 kg/(m 2 h) and 65.2%, respectively

  7. Effect of Glass Thickness on Performance of Flat Plate Solar Collectors for Fruits Drying

    Directory of Open Access Journals (Sweden)

    Ramadhani Bakari

    2014-01-01

    Full Text Available This study aimed at investigating the effect of thickness of glazing material on the performance of flat plate solar collectors. Performance of solar collector is affected by glaze transmittance, absorptance, and reflectance which results into major heat losses in the system. Four solar collector models with different glass thicknesses were designed, constructed, and experimentally tested for their performances. Collectors were both oriented to northsouth direction and tilted to an angle of 10° with the ground toward north direction. The area of each collector model was 0.72 m2 with a depth of 0.15 m. Low iron (extra clear glass of thicknesses 3 mm, 4 mm, 5 mm, and 6 mm was used as glazing materials. As a control, all collector performances were analysed and compared using a glass of 5 mm thickness and then with glass of different thickness. The results showed that change in glass thickness results into variation in collector efficiency. Collector with 4 mm glass thick gave the best efficiency of 35.4% compared to 27.8% for 6 mm glass thick. However, the use of glass of 4 mm thick needs precautions in handling and during placement to the collector to avoid extra costs due to breakage.

  8. A Phase-Adaptive Garbage Collector Using Dynamic Heap Partitioning and Opportunistic Collection

    Science.gov (United States)

    Roh, Yangwoo; Kim, Jaesub; Park, Kyu Ho

    Applications usually have their own phases in heap memory usage. The traditional garbage collector fails to match various application phases because the same heuristic on the object behavior is used throughout the entire execution. This paper introduces a phase-adaptive garbage collector which reorganizes the heap layout and adjusts the invocation time of the garbage collection according to the phases. The proposed collector identifies phases by detecting the application methods strongly related to the phase boundaries. The experimental results show that the proposed phase-adaptive collector successfully recognizes application phases and improves the garbage collection time by as much as 41%.

  9. Truncation of CPC solar collectors and its effect on energy collection

    Science.gov (United States)

    Carvalho, M. J.; Collares-Pereira, M.; Gordon, J. M.; Rabl, A.

    1985-01-01

    Analytic expressions are derived for the angular acceptance function of two-dimensional compound parabolic concentrator solar collectors (CPC's) of arbitrary degree of truncation. Taking into account the effect of truncation on both optical and thermal losses in real collectors, the increase in monthly and yearly collectible energy is also evaluated. Prior analyses that have ignored the correct behavior of the angular acceptance function at large angles for truncated collectors are shown to be in error by 0-2 percent in calculations of yearly collectible energy for stationary collectors.

  10. Dynamics and control of a solar collector system for near Earth object deflection

    International Nuclear Information System (INIS)

    Gong Shenping; Li Junfeng; Gao Yunfeng

    2011-01-01

    A solar collector system is a possible method using solar energy to deflect Earth-threatening near-Earth objects. We investigate the dynamics and control of a solar collector system including a main collector (MC) and secondary collector (SC). The MC is used to collect the sunlight to its focal point, where the SC is placed and directs the collected light to an asteroid. Both the relative position and attitude of the two collectors should be accurately controlled to achieve the desired optical path. First, the dynamical equation of the relative motion of the two collectors in the vicinity of the asteroid is modeled. Secondly, the nonlinear sliding-mode method is employed to design a control law to achieve the desired configuration of the two collectors. Finally, the deflection capability of this solar collector system is compared with those of the gravitational tractor and solar sail gravitational tractor. The results show that the solar collector is much more efficient with respect to deflection capability.

  11. Comparison of Thermal Performances between Low Porosity Perforate Plate and Flat Plate Solar Air Collector

    Science.gov (United States)

    Chan, Hoy-Yen; Vinson, A. A.; Baljit, S. S. S.; Ruslan, M. H.

    2018-04-01

    Flat plate solar air collector is the most common collector design, which is relatively simpler to fabricate and lower cost. In the present study, perforated plate solar collector was developed to improve the system thermal performance. A glazed perforated plate of 6mm holes diameter with square geometry was designed and installed as the absorber of the collector. The influences of solar radiation intensity and mass flow rate on the thermal performance were investigated. The perforated collector was compared with the flat plate solar collector under the same operating conditions. The highest values of thermal efficiency in this study for the perforated plate (PP) and the flat plate (FP) solar collectors were 59% and 36% respectively, at solar radiation intensity of 846 Wm-2 and mass flow rate of 0.02 kgs-1. Furthermore, PP collector gave better thermal performance compared to FP collector; and compared to previous studies, the present perforated design was compatible with the flat plate with double pass designs.

  12. Economical judge possibility uses solar collectors to warm service water and heating

    Directory of Open Access Journals (Sweden)

    Lívia Bodonská

    2006-09-01

    Full Text Available The sun-heated water has been used from before fossil fuels started to determine the direction of our power consumption. This article is focused on the assessing of the use of solar energy as one of inexhaustible resources that has multiple uses, including hot water service systems. Heating is rendered through solar collectors that permit to transform solar energy to warm water. We divide solar collectors into various groups but in principle they are medium temperature collectors and low temperature collectors. The work is directed also on the solar collector market. In our case the market is just at its initial stage as this technology is little known and costs of collectors are rather high, compared to our conditions, on average, they may grow up to 100,000 Slovac crowns per a family house. Because it is the only investment and the costs of operation are minimum throughout the entire collectors lifetime, from the economic point of view, it is a rather advantageous investment. Solar collectors are used in heating and also in hot service water systems in family houses, where they permit to lower costs for the consumption of many kinds of energies. In the hot service water system, solar collectors permit to lower the consumption by almost 70 %. This way of using the solar energy is very prospective and in future it will be used in various sectors

  13. Compilation of publication and results from project C2: Modelling of microclimates in collectors

    Energy Technology Data Exchange (ETDEWEB)

    Holck, O. [ed.

    1999-08-01

    It is important to avoid condensation in solar collectors, most of all because wetness of the absorber can damage the selective surface and cause corrosion on the absorber plate. During night time the cover of collectors will cool below ambient temperature due to thermal radiation to the cold sky. In climates where the air during night time becomes saturated with humidity (the relative humidity is 100%), condensation will form on the outside and inside of the collector glazing. If too much condensation takes place on the inside of the glazing, it will start to fall off on to the absorber surface. The intent of the present work is improvement of a existing computer model for calculation of microclimates data in collectors. Calculations with the model give insight in the humidity and temperature for artificial or realistic climatic data. This design tool makes it possible to calculate the effect of ventilation and insulation materials. Results from investigation of ventilation rates together with a model of the moisture inside the collector are built into the computer program. It has been found that modelling of the moisture transfer in backside insulation is essential to determine the humidity in the air gap of the collector. The objective is to develop guidelines for solar collector design to achieve the most favourable microclimates condition for materials. As a tool the computer model will be useful to fulfil this. Guidelines for collectors will be essential for manufactures to improve the long-term durability of solar collectors. (au)

  14. Hybrid Direct Carbon Fuel Cell Performance with Anode Current Collector Material

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Kammer Hansen, Kent

    2015-01-01

    collectors were studied: Au, Ni, Ag, and Pt. It was shown that the performance of the direct carbon fuel cell (DCFC) is dependent on the current collector materials, Ni and Pt giving the best performance, due to their catalytic activity. Gold is suggested to be the best material as an inert current collector......The influence of the current collector on the performance of a hybrid direct carbon fuel cell (HDCFC), consisting of solid oxide fuel cell (SOFC) with a molten carbonate-carbon slurry in contact with the anode, has been investigated using current-voltage curves. Four different anode current...

  15. Recent advances in flat plate photovoltaic/thermal (PV/T) solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Adnan; Othman, Mohd Yusof; Ruslan, Mohd Hafidz; Mat, Sohif; Sopian, Kamaruzzaman [Solar Energy Research Institute Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2011-01-15

    Flat plate photovoltaic/thermal (PV/T) solar collector produces both thermal energy and electricity simultaneously. This paper presents the state-of-the-art on flat plate PV/T collector classification, design and performance evaluation of water, air and combination of water and/or air based. This review also covers the future development of flat plate PV/T solar collector on building integrated photovoltaic (BIPV) and building integrated photovoltaic/thermal (BIPVT) applications. Different designs feature and performance of flat plate PV/T solar collectors have been compared and discussed. Future research and development (R and D) works have been elaborated. The tube and sheet design is the simplest and easiest to be manufactured, even though, the efficiency is 2% lower compared to other types of collectors such as, channel, free flow and two-absorber. It is clear from the review that for both air and water based PV/T solar collectors, the important key factors that influenced the efficiency of the system are the area where the collector covered, the number of passes and the gap between the absorber collector and solar cells. From the literature review, it is obvious that the flat plate PV/T solar collector is an alternative promising system for low-energy applications in residential, industrial and commercial buildings. Other possible areas for the future works of BIPVT are also mentioned. (author)

  16. Theoretical Study of the Compound Parabolic Trough Solar Collector

    Directory of Open Access Journals (Sweden)

    Dr. Subhi S. Mahammed

    2012-06-01

    Full Text Available Theoretical design of compound parabolic trough solar collector (CPC without tracking is presented in this work. The thermal efficiency is obtained by using FORTRAN 90 program. The thermal efficiency is between (60-67% at mass flow rate between (0.02-0.03 kg/s at concentration ratio of (3.8 without need to tracking system.The total and diffused radiation is calculated for Tikrit city by using theoretical equations. Good agreement between present work and the previous work.

  17. Lobster eye as a collector for water window microscopy

    Science.gov (United States)

    Pina, L.; Maršíková, V.; Inneman, A.; Nawaz, M. F.; Jančárek, A.; Havlíková, R.

    2017-08-01

    Imaging in EUV, SXR and XR spectral bands of radiation is of increasing interest. Material science, biology and hot plasma are examples of relevant fast developing areas. Applications include spectroscopy, astrophysics, Soft X-ray Ray metrology, Water Window microscopy, radiography and tomography. Especially Water Window imaging has still not fully recognized potential in biology and medicine microscopy applications. Theoretical study and design of Lobster Eye (LE) optics as a collector for water window (WW) microscopy and comparison with a similar size ellipsoidal mirror condensor are presented.

  18. Lower end fitting debris collector and end cap spacer grid

    International Nuclear Information System (INIS)

    Bryan, W.J.

    1990-01-01

    This patent describes a nuclear reactor having fuel assemblies including an upper end fitting and spaced nuclear fuel rod spacer grids for supporting and spacing a plurality of elongated nuclear fuel rods. Each includes a hollow active portion of nuclear fuel filled cladding intermediate the rod ends and tapering end cap of solid material with a circumferential groove on the rod end which first encounters reactor coolant flow, a lower end filtering debris collector and end cap spacer grid for capturing and retaining deleterious debris carried by reactor coolant before it enters the active region of a fuel assembly and creates fuel rod cladding damage

  19. The design of electron and ion guns, beams, and collectors

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Reinard [Institut fuer Angewandte Physik der Universitaet Frankfurt/M, Fach 180, D-60054 (Germany); Herrmannsfeldt, William B [Stanford Linear Accclerator Center, Stanford University, CA (United States)

    2004-01-01

    The well known 'SLAC Electron Trajectory Program' (EGUN) has been ported to PCs and has been developed into a family of programs for the design and the optimization of particle optics devices including electron and ion guns, beam transport sections and collectors. We will discuss the application of these tools for the design and the optimization of the essential parts of EBIS/T devices. The discussion will include conditions in which restrictions in the reliability of simulations may occur due to the mathematical modeling and how to overcome them.

  20. The design of electron and ion guns, beams, and collectors

    Science.gov (United States)

    Becker, Reinard; Herrmannsfeldt, William B.

    2004-01-01

    The well known `SLAC Electron Trajectory Program' (EGUN) has been ported to PCs and has been developed into a family of programs for the design and the optimization of particle optics devices including electron and ion guns, beam transport sections and collectors. We will discuss the application of these tools for the design and the optimization of the essential parts of EBIS/T devices. The discussion will include conditions in which restrictions in the reliability of simulations may occur due to the mathematical modeling and how to overcome them.

  1. Assessment center energy collector system of crude Puerto Escondido

    International Nuclear Information System (INIS)

    Rodríguez Sosa, Yadier; Morón Álvarez, Carlos J.; Gozá León, Osvaldo

    2015-01-01

    In this paper the results of the evaluation of the energy system Collector Crude Center of Puerto Escondido in the first half of 2014. By implementing the overall strategy presented Process Analysis developed and implemented an energy assessment procedure allowed characterize current plant conditions, and raise a number of measures and recommendations that lead to improved energy use and reduced environmental impact. It also presents the computational tools used for both process simulation (Hysys v 3.2) as for technical analysis - economic and environmental (Microsoft Excel). (full text)

  2. Fuzzy Universal Model Approximator for Distributed Solar Collector Field Control

    KAUST Repository

    Elmetennani, Shahrazed

    2014-07-01

    This paper deals with the control of concentrating parabolic solar collectors by forcing the outlet oil temperature to track a set reference. A fuzzy universal approximate model is introduced in order to accurately reproduce the behavior of the system dynamics. The proposed model is a low order state space representation derived from the partial differential equation describing the oil temperature evolution using fuzzy transform theory. The resulting set of ordinary differential equations simplifies the system analysis and the control law design and is suitable for real time control implementation. Simulation results show good performance of the proposed model.

  3. Collection strategy, inner morphology, and size distribution of dust particles in ASDEX Upgrade

    Science.gov (United States)

    Balden, M.; Endstrasser, N.; Humrickhouse, P. W.; Rohde, V.; Rasinski, M.; von Toussaint, U.; Elgeti, S.; Neu, R.; the ASDEX Upgrade Team

    2014-07-01

    The dust collection and analysis strategy in ASDEX Upgrade (AUG) is described. During five consecutive operation campaigns (2007-2011), Si collectors were installed, which were supported by filtered vacuum sampling and collection with adhesive tapes in 2009. The outer and inner morphology (e.g. shape) and elemental composition of the collected particles were analysed by scanning electron microscopy. The majority of the ˜50 000 analysed particles on the Si collectors of campaign 2009 contain tungsten—the plasma-facing material in AUG—and show basically two different types of outer appearance: spheroids and irregularly shaped particles. By far most of the W-dominated spheroids consist of a solid W core, i.e. solidified W droplets. A part of these particles is coated with a low-Z material; a process that seems to happen presumably in the far scrape-off layer plasma. In addition, some conglomerates of B, C and W appear as spherical particles after their contact with plasma. By far most of the particles classified as B-, C- and W-dominated irregularly shaped particles consist of the same conglomerate with varying fraction of embedded W in the B-C matrix and some porosity, which can exceed 50%. The fragile structures of many conglomerates confirm the absence of intensive plasma contact. Both the ablation and mobilization of conglomerate material and the production of W droplets are proposed to be triggered by arcing. The size distribution of each dust particle class is best described by a log-normal distribution allowing an extrapolation of the dust volume and surface area. The maximum in this distribution is observed above the resolution limit of 0.28 µm only for the W-dominated spheroids, at around 1 µm. The amount of W-containing dust is extrapolated to be less than 300 mg on the horizontal areas of AUG.

  4. Collection strategy, inner morphology, and size distribution of dust particles in ASDEX Upgrade

    International Nuclear Information System (INIS)

    Balden, M.; Endstrasser, N.; Rohde, V.; Rasinski, M.; Von Toussaint, U.; Elgeti, S.; Neu, R.; Humrickhouse, P.W.

    2014-01-01

    The dust collection and analysis strategy in ASDEX Upgrade (AUG) is described. During five consecutive operation campaigns (2007–2011), Si collectors were installed, which were supported by filtered vacuum sampling and collection with adhesive tapes in 2009. The outer and inner morphology (e.g. shape) and elemental composition of the collected particles were analysed by scanning electron microscopy. The majority of the ∼50 000 analysed particles on the Si collectors of campaign 2009 contain tungsten—the plasma-facing material in AUG—and show basically two different types of outer appearance: spheroids and irregularly shaped particles. By far most of the W-dominated spheroids consist of a solid W core, i.e. solidified W droplets. A part of these particles is coated with a low-Z material; a process that seems to happen presumably in the far scrape-off layer plasma. In addition, some conglomerates of B, C and W appear as spherical particles after their contact with plasma. By far most of the particles classified as B-, C- and W-dominated irregularly shaped particles consist of the same conglomerate with varying fraction of embedded W in the B–C matrix and some porosity, which can exceed 50%. The fragile structures of many conglomerates confirm the absence of intensive plasma contact. Both the ablation and mobilization of conglomerate material and the production of W droplets are proposed to be triggered by arcing. The size distribution of each dust particle class is best described by a log-normal distribution allowing an extrapolation of the dust volume and surface area. The maximum in this distribution is observed above the resolution limit of 0.28 µm only for the W-dominated spheroids, at around 1 µm. The amount of W-containing dust is extrapolated to be less than 300 mg on the horizontal areas of AUG. (paper)

  5. Collecting Comet Samples by ER-2 Aircraft: Cosmic Dust Collection During the Draconid Meteor Shower in October 2012

    Science.gov (United States)

    Bastien, Ron; Burkett, P. J.; Rodriquez, M.; Frank, D.; Gonzalez, C.; Robinson, G.-A.; Zolensky, M.; Brown, P.; Campbell-Brown, M.; Broce, S.; hide

    2014-01-01

    Many tons of dust grains, including samples of asteroids and comets, fall from space into the Earth's atmosphere each day. NASA periodically collects some of these particles from the Earth's stratosphere using sticky collectors mounted on NASA's high-flying aircraft. Sometimes, especially when the Earth experiences a known meteor shower, a special opportunity is presented to associate cosmic dust particles with a known source. NASA JSC's Cosmic Dust Collection Program has made special attempts to collect dust from particular meteor showers and asteroid families when flights can be planned well in advance. However, it has rarely been possible to make collections on very short notice. In 2012, the Draconid meteor shower presented that opportunity. The Draconid meteor shower, originating from Comet 21P/Giacobini-Zinner, has produced both outbursts and storms several times during the last century, but the 2012 event was not predicted to be much of a show. Because of these predictions, the Cosmic Dust team had not targeted a stratospheric collection effort for the Draconids, despite the fact that they have one of the slowest atmospheric entry velocities (23 km/s) of any comet shower, and thus offer significant possibilities of successful dust capture. However, radar measurements obtained by the Canadian Meteor Orbit Radar during the 2012 Draconids shower indicated a meteor storm did occur October 8 with a peak at 16:38 (+/-5 min) UTC for a total duration of approximately 2 hours.

  6. Dust of dark energy

    International Nuclear Information System (INIS)

    Lim, Eugene A.; Sawicki, Ignacy; Vikman, Alexander

    2010-01-01

    We introduce a novel class of field theories where energy always flows along timelike geodesics, mimicking in that respect dust, yet which possess non-zero pressure. This theory comprises two scalar fields, one of which is a Lagrange multiplier enforcing a constraint between the other's field value and derivative. We show that this system possesses no wave-like modes but retains a single dynamical degree of freedom. Thus, the sound speed is always identically zero on all backgrounds. In particular, cosmological perturbations reproduce the standard behaviour for hydrodynamics in the limit of vanishing sound speed. Using all these properties we propose a model unifying Dark Matter and Dark Energy in a single degree of freedom. In a certain limit this model exactly reproduces the evolution history of ΛCDM, while deviations away from the standard expansion history produce a potentially measurable difference in the evolution of structure

  7. INVESTIGATION OF PROPERTIES OF CURRENT COLLECTOR ELEMENTS AND THEIR EFFECT ON THE PERFORMANCE OF TRIBOSYSTEM «CONTACT WIRE - CURRENT COLLECTOR ELEMENT»

    Directory of Open Access Journals (Sweden)

    Yu. L. Bolshakov

    2015-11-01

    Full Text Available Purpose. The paper is devoted to the detailed analysis of interrelations at the contact point of friction pair «contact wire – current collector insert». In the work it is necessary: 1 to examine quality of manufacturing of specimens of current collector elements from different manufacturers; 2 to narrow the range of hardness for carbon inserts; 3 to develop a technique of sorting carbon current collector inserts for the structural parameters. Methodology. The executed work was based on the use of the theory of reliability of technical systems and electromechanical processes. Findings. The paper studies the interrelation at the contact point of friction pair «contact wire – current col lector insert», the connection was established between the hardness and electrical resistivity. It is proposed to narrow the range of carbon inserts hardness. The method of sorting coal collector inserts in hardness was developed, and the research has revealed the discrepancy of current collector inserts with existing regulations. It was proposed to equip the pantographs slide with current collector elements using special scheme and to develop a specialized research facility, which will be possible to conduct studies of the interaction of the friction pair «contact wire – current collector insert». Originality. In the course of the study the current collector inserts the sharp structural heterogeneity and fluctuations of the density of the material along the length of the insert were established. The dependence between hardness of inserts and electrical resistivity was established. It was analyzed and concluded about the need to reduce the values of the normal range of hardness. Based on the results of the research, the experimental dependences were obtained and proposed the method for sorting carbon current collector inserts for the structural parameters. Practical value. The obtained results of coal current collector inserts define the need to use

  8. Ulysses dust measurements near Jupiter.

    Science.gov (United States)

    Grün, E; Zook, H A; Baguhl, M; Fechtig, H; Hanner, M S; Kissel, J; Lindblad, B A; Linkert, D; Linkert, G; Mann, I B

    1992-09-11

    Submicrometer- to micrometer-sized particles were recorded by the Ulysses dust detector within 40 days of the Jupiter flyby. Nine impacts were recorded within 50 Jupiter radii with most of them recorded after closest approach. Three of these impacts are consistent with particles on prograde orbits around Jupiter and the rest are believed to have resulted from gravitationally focused interplanetary dust. From the ratio of the impact rate before the Jupiter flyby to the impact rate after the Jupiter flyby it is concluded that interplanetary dust particles at the distance of Jupiter move on mostly retrograde orbits. On 10 March 1992, Ulysses passed through an intense dust stream. The dust detector recorded 126 impacts within 26 hours. The stream particles were moving on highly inclined and apparently hyperbolic orbits with perihelion distances of >5 astronomical units. Interplanetary dust is lost rather quickly from the solar system through collisions and other mechanisms and must be almost continuously replenished to maintain observed abundances. Dust flux measurements, therefore, give evidence of the recent rates of production from sources such as comets, asteroids, and moons, as well as the possible presence of interstellar grains.

  9. Experiments on Dust Grain Charging

    Science.gov (United States)

    Abbas, M. N.; Craven, P. D.; Spann, J. F.; Tankosic, D.; LeClair, A.; West, E. A.

    2004-01-01

    Dust particles in various astrophysical environments are charged by a variety of mechanisms generally involving collisional processes with other charged particles and photoelectric emission with UV radiation from nearby sources. The sign and the magnitude of the particle charge are determined by the competition between the charging processes by UV radiation and collisions with charged particles. Knowledge of the particle charges and equilibrium potentials is important for understanding of a number of physical processes. The charge of a dust grain is thus a fundamental parameter that influences the physics of dusty plasmas, processes in the interplanetary medium and interstellar medium, interstellar dust clouds, planetary rings, cometary and outer atmospheres of planets etc. In this paper we present some results of experiments on charging of dust grains carried out on a laboratory facility capable levitating micron size dust grains in an electrodynamic balance in simulated space environments. The charging/discharging experiments were carried out by exposing the dust grains to energetic electron beams and UV radiation. Photoelectric efficiencies and yields of micron size dust grains of SiO2, and lunar simulates obtained from NASA-JSC will be presented.

  10. Tårs 10000 m2 CSP + Flat Plate Solar Collector Plant - Cost-Performance Optimization of the Design

    DEFF Research Database (Denmark)

    Perers, Bengt; Furbo, Simon; Tian, Zhiyong

    2016-01-01

    , was established. The optimization showed that there was a synergy in combining CSP and FP collectors. Even though the present cost per m² of the CSP collectors is high, the total energy cost is minimized by installing a combination of collectors in such solar heating plant. It was also found that the CSP......A novel solar heating plant with Concentrating Solar Power (CSP) collectors and Flat Plate (FP) collectors has been put into operation in Tårs since July 2015. To investigate economic performance of the plant, a TRNSYS-Genopt model, including a solar collector field and thermal storage tank...

  11. Effect of the work function and emission of the collector on the parameters of thermionic converters (TC)

    International Nuclear Information System (INIS)

    Kaibyshev, V.Z.

    1986-01-01

    In the optimal, relative to the temperature of the collector, state of modern thermionic converters (TC) the emission of the electrons from it has a substantial effect on the voltage drop in the gap. This paper preents an analysis of the boundary conditions at the collector of the TC. Calculations are presented which show that with a constant current the plasma parameters at the boundary with the collector are virtually independent of the emission from the collector right up to vanishing of the potential jump. The optimal regime with respect to temperatuer and work function of the collector is examined. The collector with a nonuniform work function is discussed

  12. On the Failure of Upscaling the Single-Collector Efficiency to the Transport of Colloids in an Array of Collectors

    Science.gov (United States)

    Messina, F.; Tosco, T.; Sethi, R.

    2017-12-01

    Colloidal transport and deposition in saturated porous media are phenomena of considerable importance in a large number of natural processes and engineering applications, such as the contaminant and microorganism propagation in aquifer systems, the development of innovative groundwater remediation technologies, air and water filtration, and many others. Therefore, a thorough understanding of particle filtration is essential for predicting the transport and fate of colloids in the subsurface environment. The removal efficiency of a filter is a key aspect for colloid transport in porous media. Several efforts were devoted to derive accurate correlations for the single collector efficiency, one of the key concept in the filtration theory. However, up scaling this parameter to the entire porous medium is still a challenge. The common up-scaling approach assumes the deposition to be independent of the transport history, which means that the collector efficiency is considered uniform along the porous medium. However, previous works showed that this approach is inadequate under unfavorable deposition conditions. This study demonstrates that it is not adequate even in the simplest case of favorable deposition. Computational Fluid Dynamics simulations were run for a simplify porous media geometry, composed of a vertical array of 50 identical spherical collectors. A combination of Lagrangian and Eulerian simulations were performed to analyze the particle transport under a broad range of parameters (i.e., particle size, particle density, water velocity). The results show the limits of the existing models to interpret the experimental data. In fact, the outcome evidenced that when particle deposition is not controlled by Brownian diffusion, non-exponential concentration profiles are retrieved, in contrast with the assumption of uniform efficiency. Moreover, when the deposition mechanisms of sedimentation and interception dominate, the efficiency of the first sphere of the

  13. Analysis of WWER 1000 SG cold collector cracking

    International Nuclear Information System (INIS)

    Matocha, K.; Wozniak, J.

    2000-01-01

    Following the recommendations of the 1993 consultants' meeting on 'Steam Generator Collector Integrity of WWER 1000 Reactors', an extensive experimental program was started with the aim of finding the dominant damage mechanism responsible for cold collector cracking in steam generators, and of determining whether proper operating conditions can make the operation of VITKOVICE-produced steam generators safe throughout their lifetime. The experiments consisted of: a study of the effect of strain and thermal ageing and dissolved oxygen content on subcritical crack growth in 10GN2MFA steel; a study of the effect of high temperature water and tube expansion technology on the fracture behaviour of ligaments between holes for heat exchange tubes; a study of the effect of drilling, tube expansion technology and heat treatment on residual stresses on the surface of holes for heat exchange tubes. Details of the experimental techniques used are given as well as a discussion of the results obtained and presented in tables and graphs. (A.K.)

  14. Slope Error Measurement Tool for Solar Parabolic Trough Collectors: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Stynes, J. K.; Ihas, B.

    2012-04-01

    The National Renewable Energy Laboratory (NREL) has developed an optical measurement tool for parabolic solar collectors that measures the combined errors due to absorber misalignment and reflector slope error. The combined absorber alignment and reflector slope errors are measured using a digital camera to photograph the reflected image of the absorber in the collector. Previous work using the image of the reflection of the absorber finds the reflector slope errors from the reflection of the absorber and an independent measurement of the absorber location. The accuracy of the reflector slope error measurement is thus dependent on the accuracy of the absorber location measurement. By measuring the combined reflector-absorber errors, the uncertainty in the absorber location measurement is eliminated. The related performance merit, the intercept factor, depends on the combined effects of the absorber alignment and reflector slope errors. Measuring the combined effect provides a simpler measurement and a more accurate input to the intercept factor estimate. The minimal equipment and setup required for this measurement technique make it ideal for field measurements.

  15. Theoretical study for solar air pretreatment collector/regenerator

    Energy Technology Data Exchange (ETDEWEB)

    Peng Donggen; Zhang Xiaosong; Yin Yonggao [School of Energy and Environment, Southeast Univ., Nanjing (China)

    2008-07-01

    A new liquid regeneration equipment - solar air pretreatment collector/regenerator for liquid desiccant cooling system is put forward in this paper, which is preferable to solution regeneration in hot and moist climate in South China. The equipment can achieve liquid regeneration in lower temperature. When the solution and the air are in ''match'' state in collector/ regenerator, a match air to salt mass ratio ASMR* is found by theoretical study in which there is the largest theoretical storage capacity SC{sub max}. After two new concepts of the effective solution proportion (EPS) and the effective storage capacity (ESC) are defined, it is found by theoretical calculation that when ESP drops from 100% to 67%, ESC raises lowly, not drops and liquid outlet concentration C{sub str} {sub sol} increases from 40% to 49% in which its increment totals to 90%. All these data explain fully that air pretreatment liquid regeneration equipment enables to improve the performance of liquid desiccant cooling system. (orig.)

  16. Hybrid photovoltaic–thermal solar collectors dynamic modeling

    International Nuclear Information System (INIS)

    Amrizal, N.; Chemisana, D.; Rosell, J.I.

    2013-01-01

    Highlights: ► A hybrid photovoltaic/thermal dynamic model is presented. ► The model, once calibrated, can predict the power output for any set of climate data. ► The physical electrical model includes explicitly thermal and irradiance dependences. ► The results agree with those obtained through steady-state characterization. ► The model approaches the junction cell temperature through the system energy balance. -- Abstract: A hybrid photovoltaic/thermal transient model has been developed and validated experimentally. The methodology extends the quasi-dynamic thermal model stated in the EN 12975 in order to involve the electrical performance and consider the dynamic behavior minimizing constraints when characterizing the collector. A backward moving average filtering procedure has been applied to improve the model response for variable working conditions. Concerning the electrical part, the model includes the thermal and radiation dependences in its variables. The results revealed that the characteristic parameters included in the model agree reasonably well with the experimental values obtained from the standard steady-state and IV characteristic curve measurements. After a calibration process, the model is a suitable tool to predict the thermal and electrical performance of a hybrid solar collector, for a specific weather data set.

  17. WWER-1000/320 steam generator collector rupture. Radiological consequences

    Energy Technology Data Exchange (ETDEWEB)

    Ivanova, A; Sartmadzhiev, A; Balabanov, E [Energoproekt, Sofia (Bulgaria)

    1996-12-31

    A model describing a hypothetical accident with direct release of primary coolant to the atmosphere is proposed. Cover lifting of the primary collector due to a rupture of the fixing bolts leads to a coolant release. The initial and boundary conditions of the accident scenario have been selected to provide for the most unfavorable conditions. The total release of primary coolant during the first 15 min of transient are estimated to 50.8 tons, of these 48.5 t with the initial activity in the primary coolant circuit. Without evacuation or sheltering, after 7 days of exposure, the expected dose at the boundary of the restricted zone is 0.0182 Sv for the whole body and 0.184 Sv for the thyroid gland. The effective equivalent dose on the site would be 0.0521 Sv. As a result of the analysis it is concluded that the steam generator collector rupture is not jeopardizing the core heat removal even with a minimum configuration of ECCS as the cooling is accomplished through the steam generators. The radiological consequences of the accident would be relatively small if an emergency procedure is applied at the 15-th minute of the transient. 1 ref.

  18. Nanoparticles Ni electroplating and black paint for solar collector applications

    Directory of Open Access Journals (Sweden)

    J. El Nady

    2016-06-01

    Full Text Available A nanoparticles layer of bright nickel base was deposited on copper substrates using electrodeposition technique before spraying the paint. IR reflectance of the paint was found to be around 0.4 without bright nickel layer and the reflectance increased to 0.6 at a Ni layer thickness of 750 nm. The efficiency of the constructed solar collectors using black paint and black paint combined with bright nickel was found to be better than black paint individually. After aging tests under high temperature, Bright nickel improved the stability of the absorber paint. The collector optical gain FR(τα was lowered by 24.7% for the commercial paint and lowered by 19.3% for the commercial paint combined with bright nickel. The overall heat loss FR(UL was increased by 3.3% for the commercial paint and increased by 2.7% for the commercial paint combined with bright nickel after the temperature aging test.

  19. Solar assisted heat pump on air collectors: A simulation tool

    Energy Technology Data Exchange (ETDEWEB)

    Karagiorgas, Michalis; Galatis, Kostas; Tsagouri, Manolis [Department of Mechanical Engineering Educators, ASPETE, N. Iraklio, GR 14121 (Greece); Tsoutsos, Theocharis [Environmental Engineering Dept., Technical University of Crete, Technical University Campus, GR 73100, Chania (Greece); Botzios-Valaskakis, Aristotelis [Centre for Renewable Energy Sources (CRES), 19th km Marathon Ave., GR 19001, Pikermi (Greece)

    2010-01-15

    The heating system of the bioclimatic building of the Greek National Centre for Renewable Energy Sources (CRES) comprises two heating plants: the first one includes an air source heat pump, Solar Air Collectors (SACs) and a heat distribution system (comprising a fan coil unit network); the second one is, mainly, a geothermal heat pump unit to cover the ground floor thermal needs. The SAC configuration as well as the fraction of the building heating load covered by the heating plant are assessed in two operation modes; the direct (hot air from the collectors is supplied directly to the heated space) and the indirect mode (warm air from the SAC or its mixture with ambient air is not supplied directly to the heated space but indirectly into the evaporator of the air source heat pump). The technique of the indirect mode of heating aims at maximizing the efficiency of the SAC, saving electrical power consumed by the compressor of the heat pump, and therefore, at optimizing the coefficient of performance (COP) of the heat pump due to the increased intake of ambient thermal energy by means of the SAC. Results are given for three research objectives: assessment of the heat pump efficiency whether in direct or indirect heating mode; Assessment of the overall heating plant efficiency on a daily or hourly basis; Assessment of the credibility of the suggested simulation model TSAGAIR by comparing its results with the TRNSYS ones. (author)

  20. A dust-free dock

    Energy Technology Data Exchange (ETDEWEB)

    Merrion, D. [E & F Services Ltd. (United Kingdom)

    2002-10-01

    This paper describes the process of unloading coal, petcoke and other dusty products in environmentally-sensitive areas. It presents a case study of the deepwater Port of Foynes on the west coast of Ireland which imports animal feed, fertiliser, coal and cement clinker, where dockside mobile loaders (DMLs) have eliminated spillage and controlled dust, and a record case study of the Humber International Terminal in the UK, where air curtinas, dust suppression grids and EFFEX{reg_sign} filters overcome the dust problems. 2 photos.

  1. Triton's streaks as windblown dust

    Science.gov (United States)

    Sagan, Carl; Chyba, Christopher

    1990-01-01

    Explanations for the surface streaks observed by Voyager 2 on Triton's southern hemisphere are discussed. It is shown that, despite Triton's tenuous atmosphere, low-cohesion dust trains with diameters of about 5 micron or less may be carried into suspension by aeolian surface shear stress, given expected geostrophic wind speeds of about 10 m/s. For geyser-like erupting dust plumes, it is shown that dust-settling time scales and expected wind velocities can produce streaks with length scales in good agreement with those of the streaks. Thus, both geyserlike eruptions or direct lifting by surface winds appear to be viable mechanisms for the origin of the streaks.

  2. [Asthma due to grain dust].

    Science.gov (United States)

    Baur, X; Preisser, A; Wegner, R

    2003-06-01

    The actual literature as well as two case reports described in detail show that grain dust induces asthmatic reactions and ODTS which are obviously not of allergic origin. For diagnosis occupational-type exposure tests are decisive whereas allergological testing usually is not. Endotoxins which are present in the grain dust samples in high concentrations have to be regarded as the major causative components. To avoid irreversible lung function impairment a comprehensive early diagnosis is necessary. Generally, a remarkable reduction of exposure to dust with high levels of airborne endotoxin in agriculture has to be achieved since in many workplaces corresponding exposures are still rather high.

  3. Solar collectors and heat pump: Market review and preliminary simulation results

    International Nuclear Information System (INIS)

    Tepe, Rainer; Roennelid, Mats

    2002-01-01

    Heating systems that combine solar collectors and a heat pump available on the market in Sweden have been studied. A majority of the systems found combine the solar collectors with a ground source heat pump. The technology for combining the collectors and the heat pump does however vary considerably. In the most simple systems, the collectors heat the return water from the heat pump, i.e. the collectors are used for raising the temperature in the boreholes for the heat pump. In the advanced systems, the solar heat is used for tap water, space heating and for raising the temperature of the heat pump's evaporator. There exist only very few comparative evaluations of the contributions from solar collectors in heat pump systems, and there is a need for finding the potential for this technique. In the present study, results are reported from preliminary simulations of solar collectors and ground source heat pumps installed in one-family houses. Simulations are made for two heating loads: 8,650 and 16,500 kWh/year resp., and a hot water load of 3,000 kWh/year. The study shows that: the temperature of the borehole decreases when solar collectors are not used (about 1.2 deg C in three years): 8 m 2 glazed solar collectors used for hot water production can reduce the electricity consumption with up to 13%, with best results in the house with low heating load: 50 m 2 unglazed solar collectors coupled to the evaporator or the borehole can give reductions of up to 14%, largest reduction in the house with high heating load, where the heat extraction from the borehole is large: the unglazed collectors have the highest economic potential, and can be cost effective for houses with high heating load: the simulations do not include a thorough system optimization, better results can be expected from continued optimization work

  4. Dust Dynamics Near Planetary Surfaces

    Science.gov (United States)

    Colwell, Joshua; Hughes, Anna; Grund, Chris

    Observations of a lunar "horizon glow" by several Surveyor spacecraft in the 1960s opened the study of the dynamics of charged dust particles near planetary surfaces. The surfaces of the Moon and other airless planetary bodies in the solar system (asteroids, and other moons) are directly exposed to the solar wind and ionizing solar ultraviolet radiation, resulting in a time-dependent electric surface potential. Because these same objects are also exposed to bombardment by micrometeoroids, the surfaces are usually characterized by a power-law size distribution of dust that extends to sub-micron-sized particles. Individual particles can acquire a charge different from their surroundings leading to electrostatic levitation. Once levitated, particles may simply return to the surface on nearly ballistic trajectories, escape entirely from the moon or asteroid if the initial velocity is large, or in some cases be stably levitated for extended periods of time. All three outcomes have observable consequences. Furthermore, the behavior of charged dust near the surface has practical implications for planned future manned and unmanned activities on the lunar surface. Charged dust particles also act as sensitive probes of the near-surface plasma environment. Recent numerical modeling of dust levitation and transport show that charged micron-sized dust is likely to accumulate in topographic lows such as craters, providing a mechanism for the creation of dust "ponds" observed on the asteroid 433 Eros. Such deposition can occur when particles are supported by the photoelectron sheath above the dayside and drift over shadowed regions of craters where the surface potential is much smaller. Earlier studies of the lunar horizon glow are consistent with those particles being on simple ballistic trajectories following electrostatic launching from the surface. Smaller particles may be accelerated from the lunar surface to high altitudes consistent with observations of high altitude

  5. Bounded dust-acoustic waves in a cylindrically bounded collisional dusty plasma with dust charge variation

    International Nuclear Information System (INIS)

    Wei Nanxia; Xue Jukui

    2006-01-01

    Taking into account the boundary, particle collisions, and dust charging effects, dust-acoustic waves in a uniform cylindrically bounded dusty plasma is investigated analytically, and the dispersion relation for the dust-acoustic wave is obtained. The effects of boundary, dust charge variation, particle collision, and dust size on the dust-acoustic wave are discussed in detail. Due to the bounded cylindrical boundary effects, the radial wave number is discrete, i.e., the spectrum is discrete. It is shown that the discrete spectrum, the adiabatic dust charge variation, dust grain size, and the particle collision have significant effects on the dust-acoustic wave

  6. Dust particle formation in silane plasmas

    NARCIS (Netherlands)

    Sorokin, M.

    2005-01-01

    Dust can be found anywhere: in the kitchen, in the car, in space… Not surprisingly we also see dust in commercial and laboratory plasmas. Dust can be introduced in the plasma, but it can also grow there by itself. In the microelectronics industry, contamination of the processing plasma by dust is an

  7. PERSPECTIVE: Dust, fertilization and sources

    Science.gov (United States)

    Remer, Lorraine A.

    2006-11-01

    Aerosols, tiny suspended particles in the atmosphere, play an important role in modifying the Earth's energy balance and are essential for the formation of cloud droplets. Suspended dust particles lifted from the world's arid regions by strong winds contain essential minerals that can be transported great distances and deposited into the ocean or on other continents where productivity is limited by lack of usable minerals [1]. Dust can transport pathogens as well as minerals great distance, contributing to the spread of human and agricultural diseases, and a portion of dust can be attributed to human activity suggesting that dust radiative effects should be included in estimates of anthropogenic climate forcing. The greenish and brownish tints in figure 1 show the wide extent of monthly mean mineral dust transport, as viewed by the MODerate resolution Imaging Spectroradiometer (MODIS) satellite sensor. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite Figure 1. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite. The brighter the color, the greater the aerosol loading. Red and reddish tints indicate aerosol dominated by small particles created primarily from combustion processes. Green and brownish tints indicate larger particles created from wind-driven processes, usually transported desert dust. Note the bright green band at the southern edge of the Saharan desert, the reddish band it must cross if transported to the southwest and the long brownish transport path as it crosses the Atlantic to South America. Image courtesy of the NASA Earth Observatory (http://earthobservatory.nasa.gov). Even though qualitatively we recognize the extent and importance of dust transport and the role that it plays in fertilizing nutrient-limited regions, there is much that is still unknown. We are just now beginning to quantify the amount of dust that exits one continental region and the

  8. Results of IEA SHC Task 45: Large Scale Solar Heating and Cooling Systems. Subtask A: “Collectors and Collector Loop”

    DEFF Research Database (Denmark)

    Bava, Federico; Nielsen, Jan Erik; Knabl, Samuel

    2016-01-01

    . Within this project, subtask A had the more specific objectives of investigating ways to evaluate the influence that different operating conditions can have on the collector performance, assure proper and safe installation of large solar collector fields, and guarantee their performance and yearly energy......The IEA SHC Task 45 Large Scale Solar Heating and Cooling Systems, carried out between January 2011 and December 2014, had the main objective to assist in the development of a strong and sustainable market of large solar heating systems by focusing on high performance and reliability of systems...... output. The results of the different investigations are presented, with a particular focus on how different parameters such as tilt, flow rate and fluid type, can affect the collector efficiency. Other presented results include methods to guarantee and check the thermal performance of a solar collector...

  9. Loess and Eolian Dust Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past environment derived from Loess and Eolian dust (silt-sized material deposited on the Earth surface by the surface winds. Parameter keywords describe...

  10. 75 FR 3881 - Combustible Dust

    Science.gov (United States)

    2010-01-25

    ..., rubber, drugs, dried blood, dyes, certain textiles, and metals (such as aluminum and magnesium..., furniture manufacturing, metal processing, fabricated metal products and machinery manufacturing, pesticide... standard that will comprehensively address the fire and explosion hazards of combustible dust. The Agency...

  11. Rethinking wood dust safety standards

    OpenAIRE

    Ratnasingam, Jega; Wai, Lim Tau; Ramasamy, Geetha; Ioras, Florin; Tadin, Ishak; Universiti Putra Malaysia; Buckinghamshire New University; Centre for Occupational Safety and Health Singapore

    2015-01-01

    The current universal work safety and health standards pertaining to wood dust in factories lack the localisation required. As a study has shown, there is a urgent need to reevaluate the current guidelines and practices.

  12. Emotion, desire and reverie in the consumption practices from the recyclable material collectors

    Directory of Open Access Journals (Sweden)

    Josilene Barbosa do Nascimento

    2014-08-01

    imagination. Thus, pointing out how works the self delusion of the collectors, characteristic of modern consumption, as we watch for the excitement and the individual values governing their consumption practices as pointing work. In this sense, the collectors consume to satiate subjectively established wills: it is the emotional consumption.

  13. Design of a collector shape for uniform flow distribution in microchannels

    International Nuclear Information System (INIS)

    Siddique, Ayyaz; Agrawal, Amit; Saha, Sandip K; Medhi, Bhaskar J; Singh, Anugrah

    2017-01-01

    The focus of this study is the design of a collector with the objective of achieving uniform flow in multiple parallel microchannels. This objective is achieved by understanding the limitations of current designs and a novel design is proposed, which is further carefully optimized. The existing collector shape considered is U-type, which is investigated numerically. The creation of a stagnation zone, growth of a boundary layer along the collector wall and low/high velocity zones in the collector are identified as the prime causes of flow maldistribution. A novel design, a dumbbell shape collector, is proposed to overcome the limitations of the earlier designs. The dumbbell shape is evaluated quantitatively and is found to perform better than all existing shapes. This dumbbell shape collector provides a uniform flow distribution with less than 0.4% relative difference from the average flow rate in different channels, which is substantially better than existing collectors with 2.3% relative difference from the average flow rate for Re ch   =  32. The uniformity is further confirmed using micro-particle image velocimetry measurements. The dumbbell shape collector is generalized and optimized to cater to heat sinks of different dimensions and to broaden its applicability in both micro and macro dimensions. (paper)

  14. Reactivities of some thiol collectors and their interactions with Ag (+1) ion by molecular modeling

    International Nuclear Information System (INIS)

    Yekeler, Hulya; Yekeler, Meftuni

    2004-01-01

    The most commonly used collectors for sulfide minerals in the mining industry are the thiol collectors for the recovery of these minerals from their associated gangues by froth flotation. For this reason, a great deal of attention has been paid to understand the attachment mechanism of thiol collectors to metal sulfide surfaces. The density functional theory (DFT) calculations at the B3LYP/3-21G* and B3LYP/6-31++G** levels were employed to propose the flotation responses of these thiol collectors, namely, diethyl dithiocarbamate, ethyl dithiocarbamate, ethyl dithiocarbonate, ethyl trithiocarbonate and ethyl dithiophosphate ions, and to study the interaction energies of these collectors with Ag (+1) ion in connection to acanthite (Ag 2 S) mineral. The calculated interaction energies, ΔE, were interpreted in terms of the highest occupied molecular orbital (HOMO) energies of the isolated collector ions. The results show that the HOMOs are strongly localized to the sulfur atoms and the HOMO energies can be used as a reactivity descriptor for the flotation ability of the thiol collectors. Using the HOMO and ΔE energies, the reactivity order of the collectors is found to be (C 2 H 5 ) 2 NCS 2 - > C 2 H 5 NHCS 2 - > C 2 H 5 OCS 2 - > C 2 H 5 SCS 2 - > (C 2 H 5 O)(OH)PS 2 - . The theoretically obtained results are in good agreement with the experimental data reported

  15. Efficiency of liquid flat-plate solar energy collector with solar tracking system

    Directory of Open Access Journals (Sweden)

    Chekerovska Marija

    2015-01-01

    Full Text Available An extensive testing programme is performed on a solar collector experimental set-up, installed on a location in Shtip (Republic of Macedonia, latitude 41º 45’ and longitude 22º 12’, in order to investigate the effect of the sun tracking system implementation on the collector efficiency. The set-up consists of two flat plate solar collectors, one with a fixed surface tilted at 30о towards the South, and the other one equipped with dual-axis rotation system. The study includes development of a 3-D mathematical model of the collectors system and a numerical simulation programme, based on the computational fluid dynamics (CFD approach. The main aim of the mathematical modelling is to provide information on conduction, convection and radiation heat transfer, so as to simulate the heat transfer performances and the energy capture capabilities of the fixed and moving collectors in various operating modes. The feasibility of the proposed method was confirmed by experimental verification, showing significant increase of the daily energy capture by the moving collector, compared to the immobile collector unit. The comparative analysis demonstrates a good agreement between the experimental and numerically predicted results at different running conditions, which is a proof that the presented CFD modelling approach can be used for further investigations of different solar collectors configurations and flow schemes.

  16. A non-linear steady state characteristic performance curve for medium temperature solar energy collectors

    Science.gov (United States)

    Eames, P. C.; Norton, B.

    A numerical simulation model was employed to investigate the effects of ambient temperature and insolation on the efficiency of compound parabolic concentrating solar energy collectors. The limitations of presently-used collector performance characterization curves were investigated and a new approach proposed.

  17. Performance of nanofluids on heat transfer in a wavy solar collector ...

    African Journals Online (AJOL)

    The bottom wavy solid surface is kept at a constant temperature Tc. Numerical analysis is done by this article for the performance of different nanofluids on convective flow and heat transfer phenomena inside a solar collector. The solar collector has the flatplate cover and sinusoidal wavy absorber. Two different nanofluids ...

  18. The Experimental Performance of an Unglazed PVT Collector with Two Different Absorber Types

    Directory of Open Access Journals (Sweden)

    Jin-Hee Kim

    2012-01-01

    Full Text Available Photovoltaic-thermal collectors combine photovoltaic modules and solar thermal collectors, forming a single device that produces electricity and heat simultaneously. There are two types of liquid-type PVT collectors, depending on the existence or absence of a glass cover over the PV module. The glass-covered (glazed PVT collector produces relatively more thermal energy but has a lower electrical yield, whereas the uncovered (unglazed PVT collector has a relatively low thermal energy and somewhat higher electrical performance. The thermal and electrical performance of liquid-type PVT collectors is related not only to the collector design, such as whether a glass cover is used, but also to the absorber design, that is, whether the absorber is for the sheet-and-tube type or the fully wetted type. The design of the absorber, as it comes into contact with the PV modules and the liquid tubes, is regarded as important, as it is related to the heat transfer from the PV modules to the liquid in the tubes. In this paper, the experimental performance of two liquid-type PVT collectors, a sheet-and-tube type and a fully wetted type, was analyzed.

  19. Characteristics of evacuated tubular solar thermal collector as input energy for cooling system at Universitas Indonesia

    Science.gov (United States)

    Alhamid, M. Idrus; Nasruddin, Aisyah, Nyayu; Sholahudin

    2017-03-01

    This paper discussed the use of solar thermal collector as an input energy for cooling system. The experimental investigation was undertaken to characterize solar collectors that have been integrated with an absorption chiller. About 62 modules of solar collectors connected in series and parallel are placed on the roof top of MRC building. Thermistors were used to measure the fluid temperature at inlet, inside and outlet of each collector, inside the water tank and ambient temperature. Water flow that circulated from the storage was measured by flow meter, while solar radiation was measured by a pyranometer that was mounted parallel to the collector. Experimental data for a data set was collected in March 2016, during the day time hours of 08:00 - 17:00. This data set was used to calculate solar collector efficiency. The results showed that in the maximum solar radiation, the outlet temperature that can be reached is about 78°C, the utilized energy is about 70 kW and solar collector has an efficiency of 64%. While in the minimum solar radiation, the outlet temperature that can be reached is about 53°C, the utilized energy is about 28 kW and solar collector has an efficiency of 43%.

  20. 78 FR 38452 - Price for the 2013 Girl Scouts of the USA Young Collector Set

    Science.gov (United States)

    2013-06-26

    ... DEPARTMENT OF THE TREASURY United States Mint Price for the 2013 Girl Scouts of the USA Young Collector Set AGENCY: United States Mint, Department of the Treasury. ACTION: Notice. SUMMARY: The United States Mint is announcing a price of $54.95 for the 2013 Girl Scouts of the USA Young Collector Set. FOR...

  1. Design and performance verification of advanced multistage depressed collectors. [traveling wave tubes for ECM

    Science.gov (United States)

    Kosmahl, H.; Ramins, P.

    1975-01-01

    Design and performance of a small size, 4-stage depressed collector are discussed. The collector and a spent beam refocusing section preceding it are intended for efficiency enhancement of octave bandwidth, high CW power traveling wave tubes for use in ECM.

  2. Air-liquid solar collector for solar heating, combined heating and cooling, and hot water subsystems

    Science.gov (United States)

    1978-01-01

    A collection of quarterly reports consisting of the installation and layout design of the air collector system for commercial applications, completion of the preliminary design review, detailed design efforts, and preparation of the verification test plan are given. Performance specifications and performance testing of a prototype model of a two manifold, 144 tube air collector array is presented.

  3. Evaluating the thermal and electrical performance of several uncovered PVT collectors with a field test

    NARCIS (Netherlands)

    de Keizer, C.; de Jong, M.; Mendes, T.; Katiyar, M.; Folkerts, W.; Rindt, C.C.M.; Zondag, H.A.

    Recently, there has been a lot of interest in PV thermal systems, which generate both heat and power. Within the WenSDak project, several companies and research institutes work together to (further) develop several uncovered PVT collectors. The outdoor performance of prototypes of these collectors

  4. Physical properties of five grain dust types.

    OpenAIRE

    Parnell, C B; Jones, D D; Rutherford, R D; Goforth, K J

    1986-01-01

    Physical properties of grain dust derived from five grain types (soybean, rice, corn, wheat, and sorghum) were measured and reported. The grain dusts were obtained from dust collection systems of terminal grain handling facilities and were assumed to be representative of grain dust generated during the handling process. The physical properties reported were as follows: particle size distributions and surface area measurements using a Coulter Counter Model TAII; percent dust fractions less tha...

  5. Efficient radiative transfer in dust grain mixtures

    OpenAIRE

    Wolf, S.

    2002-01-01

    The influence of a dust grain mixture consisting of spherical dust grains with different radii and/or chemical composition on the resulting temperature structure and spectral energy distribution of a circumstellar shell is investigated. The comparison with the results based on an approximation of dust grain parameters representing the mean optical properties of the corresponding dust grain mixture reveal that (1) the temperature dispersion of a real dust grain mixture decreases substantially ...

  6. Review of state-of-the-art of solar collector corrosion processes. Task 1 of solar collector studies for solar heating and cooling applications. Final technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Clifford, J E; Diegle, R B

    1980-04-11

    The state-of-the-art of solar collector corrosion processes is reviewed, and Task 1 of a current research program on use of aqueous heat transfer fluids for solar heating and cooling is summarized. The review of available published literature has indicated that lack of quantitative information exists relative to collector corrosion at the present time, particularly for the higher temperature applications of solar heating and cooling compared to domestic water heating. Solar collector systems are reviewed from the corrosion/service life viewpoint, with emphasis on various applications, collector design, heat transfer fluids, and freeze protection methods. Available information (mostly qualitative) on collector corrosion technology is reviewed to indicate potential corrosion problem areas and corrosion prevention practices. Sources of limited quantitative data that are reviewed are current solar applications, research programs on collector corrosion, and pertinent experience in related applications of automotive cooling and non-solar heating and cooling. A data bank was developed to catalog corrosion information. Appendix A of this report is a bibliography of the data bank, with abstracts reproduced from presently available literature accessions (about 220). This report is presented as a descriptive summary of information that is contained in the data bank.

  7. Grain dust and the lungs.

    Science.gov (United States)

    Chan-Yeung, M.; Ashley, M. J.; Grzybowski, S.

    1978-01-01

    Grain dust is composed of a large number of materials, including various types of grain and their disintegration products, silica, fungi, insects and mites. The clinical syndromes described in relation to exposure to grain dust are chronic bronchitis, grain dust asthma, extrinsic allergic alveolitis, grain fever and silo-filler's lung. Rhinitis and conjunctivitis are also common in grain workers. While the concentration and the quality of dust influence the frequency and the type of clinical syndrome in grain workers, host factors are also important. Of the latter, smoking is the most important factor influencing the frequency of chronic bronchitis. The role of atopy and of bronchial hyperreactivity in grain dust asthma has yet to be assessed. Several well designed studies are currently being carried out in North America not only to delineate the frequency of the respiratory abnormalities, the pathogenetic mechanisms and the host factors, but also to establish a meaningful threshold limit concentration for grain dust. Images p1272-a PMID:348288

  8. Charged dust structures in plasmas

    International Nuclear Information System (INIS)

    Cramer, N.F.; Vladimirov, S.V.

    1999-01-01

    We report here on theoretical investigations of the mechanical-electrostatic modes of vibration of a dust-plasma crystal, extending earlier work on the transverse modes of a horizontal line of grains (where the ions flow vertically downward to a plane horizontal cathode), the modes of two such lines of grains, and the modes of a vertical string of grains. The last two arrangements have the unique feature that the effect of the background plasma on the mutual grain interaction is asymmetric because of the wake downstream of the grains studied in. The characteristic frequencies of the vibrations are dependent on the parameters of the plasma and the dust grains, such as the Debye length and the grain charge, and so measurement of the frequencies could provide diagnostics of these quantities. Although the current boom in dusty plasma research is driven mainly by such industrial applications as plasma etching, sputtering and deposition, the physical outcomes of investigations in this rapidly expanding field cover many important topics in space physics and astrophysics as well. Examples are the interaction of dust with spacecraft, the structure of planetary rings, star formation, supernova explosions and shock waves. In addition, the study of the influence of dust in environmental research, such as in the Earth's ionosphere and atmosphere, is important. The unique binding of dust particles in a plasma opens possibilities for so-called super-chemistry, where the interacting bound elements are not atoms but dust grains

  9. Suspended dust in Norwegian cities

    International Nuclear Information System (INIS)

    2001-01-01

    According to calculations, at least 80 000 people in Oslo and 8 000 in Trondheim were annoyed by too much suspended dust in 2000. The dust concentration is greatest in the spring, presumably because dust is swirling up from melting snow and ice on the streets. Car traffic is the main source of the dust, except for some of the most highly exposed regions where wood-firing from old stoves contributes up to 70 percent of the dust. National targets for air quality include suspended dust, nitrogen dioxide, sulphur dioxide and benzene. Calculations show that nitrogen dioxide emissions exceeding the limit affected 4 000 people in Oslo and 1 000 people in Trondheim. The sulphur dioxide emissions in the major cities did non exceed the national quality limit; they did exceed the limit in some of the smaller industrial centres. In Trondheim, measurements show that the national limit for benzene was exceeded. Most of the emission of nitrogen dioxide comes from the road traffic. Local air pollution at times causes considerable health- and well-being problems in the larger cities and industrial centres, where a great part of the population may be at risk of early death, infection of the respiratory passage, heart- and lung diseases and cancer

  10. Flotation performances and surface properties of chalcopyrite with xanthate collector added before and after grinding

    Science.gov (United States)

    Peng, Huiqing; Wu, Di; Abdelmonem, Mohamed

    In this study, effects of the collector added before grinding and after grinding on the subsequent flotation and mineral surface properties were investigated. The pH was controlled at 10 during the grinding and flotation processes opened to the atmosphere. With enough amounts of sodium butyl xanthate addition, adding the collector before grinding recovered more chalcopyrite than adding it after grinding in single mineral flotation. The Eh of each ground pulp before and after conditioning were measured and it was found that adding collector before grinding obtained higher and relatively suitable pulp potential for chalcopyrite flotation. Particle size analyses of the flotation products indicate that the different flotation recoveries occurred due to the different flotation losses in fine particles (flotation feedings and found that more carbon and oxygen, and less iron were remained on mineral surfaces when the collector was added before grinding, due to the higher collector adsorption capacity, larger free oxygen adsorbance and less iron oxide/hydroxide species.

  11. High-performance supercapacitors using a nanoporous current collector made from super-aligned carbon nanotubes

    Science.gov (United States)

    Zhou, Ruifeng; Meng, Chuizhou; Zhu, Feng; Li, Qunqing; Liu, Changhong; Fan, Shoushan; Jiang, Kaili

    2010-08-01

    Nanoporous current collectors for supercapacitors have been fabricated by cross-stacking super-aligned carbon nanotube (SACNT) films as a replacement for heavy conventional metallic current collectors. The CNT-film current collectors have good conductivity, extremely low density (27 µg cm - 2), high specific surface area, excellent flexibility and good electrochemical stability. Nanosized active materials such as NiO, Co3O4 or Mn2O3 nanoparticles can be directly synthesized on the SACNT films by a straightforward one-step, in situ decomposition strategy that is both efficient and environmentally friendly. These composite films can be integrated into a pseudo-capacitor that does not use metallic current collectors, but nevertheless shows very good performance, including high specific capacitance (~500 F g - 1, including the current collector mass), reliable electrochemical stability (<4.5% degradation in 2500 cycles) and a very high rate capability (245 F g - 1 at 155 A g - 1).

  12. Influence of reflectance from flat aluminum concentrators on energy efficiency of PV/Thermal collector

    International Nuclear Information System (INIS)

    Kostic, Ljiljana T.; Pavlovic, Tomislav M.; Pavlovic, Zoran T.

    2010-01-01

    In this paper the results of the influence of reflectance from flat plate solar radiation concentrators made of Al sheet and Al foil on energy efficiency of PV/Thermal collector are presented. The total reflectance from concentrators made of Al sheet and Al foil is almost the same, but specular reflectance which is bigger in concentrators made of Al foil results in increase of solar radiation intensity concentration factor. With the increase of solar radiation intensity concentration factor, total daily thermal and electrical energy generated by PV/Thermal collector with concentrators increase. In this work also optimal position of solar radiation concentrators made of Al sheet and Al foil and appropriate thermal and electrical efficiency of PV/Thermal collector have been determined. Total energy generated by PV/Thermal collector with concentrators made of Al foil in optimal position is higher than total energy generated by PV/Thermal collector with concentrators made of Al sheet.

  13. Solar powered adsorption refrigerator with CPC collection system: Collector design and experimental test

    International Nuclear Information System (INIS)

    Gonzalez, Manuel I.; Rodriguez, Luis R.

    2007-01-01

    Solar adsorption cooling systems are usually based on the flat plate collector, whereas little attention has been paid to concentrating collectors. Compound parabolic concentrators (CPC) are a versatile class of solar collectors that can be adapted to a large variety of applications and geometries. This work presents a CPC collector whose tubular receiver contains the sorption bed and where only a portion of the receiver is exposed to sunlight. Geometric characteristics of the proposed CPC, such as the profile, the length and the height of the reflective sheet are given. A prototype of a solar adsorption chiller using this type of collector and the activated carbon-methanol working pair is described, and typical experimental results are reported. In particular, the measured solar COP ranges from 0.078 to 0.096

  14. Modeling Heat Flow In a Calorimeter Equipped With a Textured Solar Collector

    Science.gov (United States)

    Jaworske, Donald A.; Allen, Bradley J.

    2001-01-01

    Heat engines are being considered for generating electric power for minisatellite applications, particularly for those missions in high radiation threat orbits. To achieve this objective, solar energy must be collected and transported to the hot side of the heat engine. A solar collector is needed having the combined properties of high solar absorptance, low infrared emittance, and high thermal conductivity. To test candidate solar collector concepts, a simple calorimeter was designed, manufactured, and installed in a bench top vacuum chamber to measure heat flow. In addition, a finite element analysis model of the collector/calorimeter combination was made to model this heat flow. The model was tuned based on observations from the as-manufactured collector/calorimeter combination. In addition, the model was exercised to examine other collector concepts, properties, and scale up issues.

  15. Experimental evaluation of flat plate solar collector using nanofluids

    International Nuclear Information System (INIS)

    Verma, Sujit Kumar; Tiwari, Arun Kumar; Chauhan, Durg Singh

    2017-01-01

    Highlights: • Solar collectors are special kind of heat exchangers. • Particle concentration is important parameter for thermal conductivity of nanofluid. • Rise of Bejan number indicates systems qualitative response. • Multi walled carbon nanotube is best performing. - Abstract: The present analysis focuses on a wide variety of nanofluids for evaluating performance of flat plate solar collector in terms of various parameters as well as in respect of energy and exergy efficiency. Also, based on our experimental findings on varying mass flow rate, the present investigation has been conducted with optimum particle volume concentration. Experiments indicate that for ∼0.75% particle volume concentration at a mass flow rate of 0.025 kg/s, exergy efficiency for Multi walled carbon nanotube/water nanofluid is enhanced by 29.32% followed by 21.46%, 16.67%, 10.86%, 6.97% and 5.74%, respectively for Graphene/water, Copper Oxide water, Aluminum Oxide/water, Titanium oxide/water, and Silicon Oxide/water respectively instead of water as the base fluid. Entropy generation, which is a drawback, is also minimum in Multiwalled carbon nanotube/water nanofluids. Under the same thermophysical parameters, the maximum drop in entropy generation can be observed in Multiwalled carbon nanotube/water, which is 65.55%, followed by 57.89%, 48.32%, 36.84%, 24.49% and 10.04%, respectively for graphene/water, copper oxide/water, Aluminum/water, Titanium Oxide /water, and Silicon oxide /water instead of water as the base fluid. Rise of Bejan number towards unity emphasizes improved system performance in terms of efficient conversion of the available energy into useful functions. The highest rise in energy efficiency of a collector has been recorded in Multiwalled carbon nanotube/water, which is 23.47%, followed by 16.97%, 12.64%, 8.28%, 5.09% and 4.08%, respectively for graphene/water, Copper oxide/water, Aluminum oxide/water, Titanium oxide /water, and Silicon oxide/water instead of

  16. A hybrid air conditioner driven by a hybrid solar collector

    Science.gov (United States)

    Al-Alili, Ali

    The objective of this thesis is to search for an efficient way of utilizing solar energy in air conditioning applications. The current solar Air Conditioners (A/C)s suffer from low Coefficient of Performance (COP) and performance degradation in hot and humid climates. By investigating the possible ways of utilizing solar energy in air conditioning applications, the bottlenecks in these approaches were identified. That resulted in proposing a novel system whose subsystem synergy led to a COP higher than unity. The proposed system was found to maintain indoor comfort at a higher COP compared to the most common solar A/Cs, especially under very hot and humid climate conditions. The novelty of the proposed A/C is to use a concentrating photovoltaic/thermal collector, which outputs thermal and electrical energy simultaneously, to drive a hybrid A/C. The performance of the hybrid A/C, which consists of a desiccant wheel, an enthalpy wheel, and a vapor compression cycle (VCC), was investigated experimentally. This work also explored the use of a new type of desiccant material, which can be regenerated with a low temperature heat source. The experimental results showed that the hybrid A/C is more effective than the standalone VCC in maintaining the indoor conditions within the comfort zone. Using the experimental data, the COP of the hybrid A/C driven by a hybrid solar collector was found to be at least double that of the current solar A/Cs. The innovative integration of its subsystems allows each subsystem to do what it can do best. That leads to lower energy consumption which helps reduce the peak electrical loads on electric utilities and reduces the consumer operating cost since less energy is purchased during the on peak periods and less solar collector area is needed. In order for the proposed A/C to become a real alternative to conventional systems, its performance and total cost were optimized using the experimentally validated model. The results showed that for an

  17. Standardized performance tests of collectors of solar thermal energy: A selectively coated, flat-plate copper collector with one transparent cover and a tube-to-tube spacing of 5 5/8 inches

    Science.gov (United States)

    1976-01-01

    This preliminary data report gives basic test results of a flat-plate solar collector whose performance was determined in the NASA-Lewis solar simulator. The collector was tested over ranges of inlet temperatures, fluxes and coolant flow rates. Collector efficiency is correlated in terms of inlet temperature and flux level.

  18. Standard performance tests of collectors of solar thermal energy: A selectively coated, flat-plate copper collector with one transparent cover and a tube-to-tube spacing of 3-7/8 inches

    Science.gov (United States)

    1976-01-01

    Basic test results are given of a flat-plate solar collector whose performance was determined in the NASA-Lewis solar simulator. The collector was tested over ranges of inlet temperatures, fluxes, and coolant flow rates. Collector efficiency is correlated in terms of inlet temperature and flux level.

  19. Method of forming oxide coatings. [for solar collector heating panels

    Science.gov (United States)

    Mcdonald, G. E. (Inventor)

    1983-01-01

    This invention is concerned with an improved plating process for covering a substrate with a black metal oxide film. The invention is particularly directed to making a heating panel for a solar collector. A compound is electrodeposited from an aqueous solution containing cobalt metal salts onto a metal substrate. This compound is converted during plating into a black, highly absorbing oxide coating which contains hydrated oxides. This is achieved by the inclusion of an oxidizing agent in the plating bath. The inclusion of an oxidizing agent in the plating bath is contrary to standard electroplating practice. The hydrated oxides are converted to oxides by treatment in a hot bath, such as boiling water. An oxidizing agent may be added to the hot liquid treating bath.

  20. Particle collector scoops for improved exhaust in ''axisymmetric'' devices

    International Nuclear Information System (INIS)

    Conn, R.W.; Wolf, G.H.

    1987-11-01

    Application of particle collector scoops in front of the pumping ducts of axisymmetric divertor/magnetic limiter configurations is proposed. These scoops should enclose a significant fraction of the recycling particles. The resulting increase in natural particle pressure in front of the pumping ducts leads to an improved exhaust efficiency. This can permit an extension of the operational margin for density control. Alternatively, aiming at a prescribed exhaust flow in reactor-type devices such as INTOR, the pumping ducts could be reduced in aperture, leaving valuable space for other components. The lay-out of the proposed scheme depends on the heat load on the leading edge in front of the scoop and on the deflector in front of the pumping ducts. 14 refs., 5 figs

  1. Solar heat collector-generator for cooling purposes

    Science.gov (United States)

    Abdullah, K.

    1982-01-01

    The performance of an experimental LiBr-H2O solar collector powered absorption cooling system is described. A numerical model was developed of the energy, mass, and momentum balances across the heat-exchange loop to obtain the refrigerant vapor generation rate. The mechanism works by the thermosiphon principle, which eliminates mechanical devices from the loop. All leaks were fixed before measurements began with a test apparatus comprising a pyrex tube 1.87 m long with a 2.7 i.d. The refrigerant flow rate was monitored, along with temperature changes in the fluid and across the tube. Bubble initiation was observed from the free surface extending downward in the tube. Reynolds numbers varied from 6-43 in the liquid phase and 81-204 in the vapor phase. A formulation was made for the low-velocity two-phase flow and good agreement was demonstrated with the simulation.

  2. Air-borne shape measurement of parabolic trough collector fields

    Science.gov (United States)

    Prahl, Christoph; Röger, Marc; Hilgert, Christoph

    2017-06-01

    The optical and thermal efficiency of parabolic trough collector solar fields is dependent on the performance and assembly accuracy of its components such as the concentrator and absorber. For the purpose of optical inspection/approval, yield analysis, localization of low performing areas, and optimization of the solar field, it is essential to create a complete view of the optical properties of the field. Existing optical measurement tools are based on ground based cameras, facing restriction concerning speed, volume and automation. QFly is an airborne qualification system which provides holistic and accurate information on geometrical, optical, and thermal properties of the entire solar field. It consists of an unmanned aerial vehicle, cameras and related software for flight path planning, data acquisition and evaluation. This article presents recent advances of the QFly measurement system and proposes a methodology on holistic qualification of the complete solar field with minimum impact on plant operation.

  3. Fast time-resolved aerosol collector: proof of concept

    Science.gov (United States)

    Yu, X.-Y.; Cowin, J. P.; Iedema, M. J.; Ali, H.

    2010-10-01

    Atmospheric particles can be collected in the field on substrates for subsequent laboratory analysis via chemically sensitive single particle methods such as scanning electron microscopy with energy dispersive x-ray analysis. With moving substrates time resolution of seconds to minutes can be achieved. In this paper, we demonstrate how to increase the time resolution when collecting particles on a substrate to a few milliseconds to provide real-time information. Our fast time-resolved aerosol collector ("Fast-TRAC") microscopically observes the particle collection on a substrate and records an on-line video. Particle arrivals are resolved to within a single frame (4-17 ms in this setup), and the spatial locations are matched to the subsequent single particle analysis. This approach also provides in-situ information on particle size and number concentration. Applications are expected in airborne studies of cloud microstructure, pollution plumes, and surface long-term monitoring.

  4. Thermomechanical Assessment of the Collector for the Hollow Electron Lens

    CERN Document Server

    Anderson, George Bowers

    2017-01-01

    The hollow electron lens (HEL) is a system proposed for the High Luminosity upgrade of the Large Hadron Collider LHC (HL-LHC) [1]. Being considered for installation at LHC point 4, the HEL improves halo control and collimation of proton beams in the collider [2]. This is achieved by creating a hollow tube of electrons using an electron gun. This axisymmetric electron cloud travels around the proton beam for a few meters, overlapping with the proton beam halo, until the electron cloud is dissipated in a collector, which is the focus of this project. A 3D image of the HEL system is found in Figure 1 and a further technical description of such electron lenses is available in [3].

  5. Oil/gas collector/separator for underwater oil leaks

    Energy Technology Data Exchange (ETDEWEB)

    Henning, C.D.

    1992-12-31

    This invention is comprised of an oil/gas collector/separator for recovery of oil leaking, for example, from an offshore or underwater oil well. The separator is floated over the point of the leak and tethered in place so as to receive oil/gas floating, or forced under pressure, toward the water surface from either a broken or leaking oil well casing, line, or sunken ship. The separator is provided with a downwardly extending skirt to contain the oil/gas which floats or is forced upward into a dome wherein the gas is separated from the oil/water, with the gas being flared (burned) at the top of the dome, and the oil is separated from water and pumped to a point of use. Since the density of oil is less than that of water it can be easily separated from any water entering the dome.

  6. Characterization of cable gun plasma with a charge collector array

    International Nuclear Information System (INIS)

    Chen Yulan; Zeng Zhengzhong; Sun Fengju; Kuai Bin; Qiu Aici; Yin Jiahui; Cong Peitian; Liang Tianxue

    2003-01-01

    The density, drift velocity and reproducibility of the plasma produced by a cable plasma gun array have been measured with a charge collector array. The plasma is used to prefill a coaxial plasma-opening switch with a conducting time approaching 0.4 μs. The reproducibility of the plasma source in subsequent shots is better than 5%. Near the gun nozzle and the opposite electrode, the plasma density amounts to 10 15 cm -3 , which is 2 times to 3 times that in the gap between the two coaxial electrodes. A plasma drift velocity of about 2.4 cm/μs is observed from the time of flight of the charged particles. Both plasma density and drift velocity increase almost linearly with the rise in charge voltage

  7. Forged hollows (alloy 617) for PNP-hot gas collectors

    International Nuclear Information System (INIS)

    Hofmann, F.

    1984-01-01

    When the partners in the PNP-Project decided to manufacture components, such as gas collectors, from material of type alloy 617, the problem arose that required semi-fabricated products, especially forged hollows weighing several tons each, were not available. As VDM (Vereinigte Deutsche Metallwerke AG) had already experience in production of other semi-fabricated products of this alloy, attempts were made based on this knowledge, to develop manufacturing methods for forged hollows. The aim was to produce hollows as long as possible, and to keep the welding cost minimum. Welded seams are always critical during fabrication, as well as during later inspection under actual operating conditions. The three stage plan used to perform the above task illustrates the development aims is described

  8. Structural evaluation of a DTHR bundle divertor particle collector

    International Nuclear Information System (INIS)

    Prevenslik, T.V.

    1980-09-01

    The purpose of this report is to present a structural evaluation of the current bundle divertor particle collector BDPC design under a peak heat flux in relation to criteria that protect against coolant leakage into the plasma over replacement schedules planned during DTHR operation. In addition, an assessment of the BDPC structural integrity at higher heat fluxes is presented. Further, recommendations for modifications in the current BDPC design that would improve design reliability to be considered in future design studies are described. Finally, experimental test programs directed to establishing materials data necessary in providing greater confidence in subsequent structural evaluations of BDPC designs in relation to coolant leakage over planned replacement schedules are identified

  9. Convective drying of chilies using a concentrating solar collector

    International Nuclear Information System (INIS)

    Hanif, M.; Khattak, M.K.; Aamir, M.

    2015-01-01

    A concentrating solar collector was developed for convective drying of green chilies by providing optimum drying environment. A temperature in the range of 45-65 degree C and relative humidity of less than 10% was observed during the drying period provided by the solar collector from 9.00 am to 5.00 pm. Different levels of drying temperature and air mass flow rates were tested to find their effect on drying time of the chilies. The experiment was laid out as a randomized complete block design with a factorial arrangement of the treatments consisting of 3 levels of temperature and 3 levels of air mass flow rate, replicated 3 times. Drying temperature and air mass flow rates effected the drying time significantly. The means comparison showed that minimum drying time of 17.96 h was recorded at high temperature of 65 degree C followed by a drying time of 20.27 and 21.43 h at temperatures of 55 and 45 degree C. The means of air mass flow rates showed that minimum drying time of 18.49 h was noted at high air mass flow rate of 3.50 kg min-1 followed by 20.32 and 20.86 h at air mass flow rates of 1.5 and 2.30 kg min-l. Chilies dried at temperature of 65 degree C and air mass flow rate of 3.5 kg min-1 showed an average drying rate of 0.02 g(H20)hrl cm-2as compared to the slow drying rates at 55 and 45 degree C. It was concluded that chilies must be dried at high temperature and high air mass flow rates to get on time quality dried chilies. (author)

  10. Experimental System of Solar Adsorption Refrigeration with Concentrated Collector.

    Science.gov (United States)

    Yuan, Z X; Li, Y X; Du, C X

    2017-10-18

    To improve the performance of solar adsorption refrigeration, an experimental system with a solar concentration collector was set up and investigated. The main components of the system were the adsorbent bed, the condenser, the evaporator, the cooling sub-system, and the solar collector. In the first step of the experiment, the vapor-saturated bed was heated by the solar radiation under closed conditions, which caused the bed temperature and pressure to increase. When the bed pressure became high enough, the bed was switched to connect to the condenser, thus water vapor flowed continually from the bed to the condenser to be liquefied. Next, the bed needed to cool down after the desorption. In the solar-shielded condition, achieved by aluminum foil, the circulating water loop was opened to the bed. With the water continually circulating in the bed, the stored heat in the bed was took out and the bed pressure decreased accordingly. When the bed pressure dropped below the saturation pressure at the evaporation temperature, the valve to the evaporator was opened. A mass of water vapor rushed into the bed and was adsorbed by the zeolite material. With the massive vaporization of the water in the evaporator, the refrigeration effect was generated finally. The experimental result has revealed that both the COP (coefficient of the performance of the system) and the SCP (specific cooling power of the system) of the SAPO-34 zeolite was greater than that of the ZSM-5 zeolite, no matter whether the adsorption time was longer or shorter. The system of the SAPO-34 zeolite generated a maximum COP of 0.169.

  11. Application of solar flat plate collector in automobile industry

    Energy Technology Data Exchange (ETDEWEB)

    Wawge, P. [Peenya Alloys Pvt. Ltd., Parvati, Pune (India)

    2004-07-01

    In any industry, heating, cooling and compressed air the costliest part, which affects the production cost of any product. There are three types of indirect heat requirement or the requirement of heat can be divided in the three main categories. (1) low temp. 40 - 60 Deg. (2) Medium temp. 80 - 150 deg. (3) High Temp applications - above 150. Solar Flat Collectors have been proven for the use of solar energy for medium temp. application in hotels, boiler feed water preheating, dairy for pasteurization and some other indirect heating applications. There is another neglected area of application of Solar Flat Plate collector is heat treatment for powder coating plants where heat requirement is bet 50 Deg C - 70 Deg C. In any automobile industry the aesthetic or look of the vehicle place a very important role as far as the sale is concern (after the mechanical performance). The aesthetic means the body and colour of the vehicle. To get a long lasting good quality color, the powder coating procedure plays a major role. Before powder coating there is requirement of different chemical treatment for the removal of rust, grease and other cleaning of the specific sheet metal body parts. The time duration and chemical composition is depends on the selection of body material. A proven method of a chemical treatment is seven / eight tank process. The common system of heating chemicals is by way of electrical heaters, by diesel or other fuel fired boilers. This increases the cost of heat treatment process due the high cost of electricity (for industries rate of electricity is 1.5 to 2 times than the domestic rate) or oils. This can be replaced by Solar water heating system which can efficiently generate the temp of liquid upto 85 Deg C. (orig.)

  12. Performance and cost benefits analysis of double-pass solar collector with and without fins

    International Nuclear Information System (INIS)

    Fudholi, Ahmad; Sopian, Kamaruzzaman; Ruslan, Mohd Hafidz; Othman, Mohd Yusof

    2013-01-01

    Highlights: • The thermal performances and cost analysis of the double-pass solar collector with and without fins absorber were discussed. • The theoretical and experimental study on the double-pass solar air collector with and without fins absorber was conducted. • The ratio of AC/AEG or the cost benefit ratio was presented. • The double-pass solar collector with fins absorber is more cost-effective compared to without fins absorber. - Abstract: The performance and cost benefit analysis of double-pass solar collector with and without fins have been conducted. The theoretical model using steady state analysis has been developed and compared with the experimental results. The performance curves of the double-pass solar collector with and without fins, which included the effects of mass flow rate and solar intensity on the thermal efficiency of the solar collector, were obtained. Results indicated that the thermal efficiency is proportional to the solar intensity at a specific mass flow rate. The thermal efficiency increased by 9% at a solar intensity of 425–790 W/m 2 and mass flow rate of 0.09 kg/s. The theoretical and experimental analysis showed a similar trend as well as close agreement. Moreover, a cost-effectiveness model has been developed examine the cost benefit ratio of double-pass solar collector with and without fins. Evaluation of the annual cost (AC) and the annual energy gain (AEG) of the collector were also performed. The results show that the double-pass solar collector with fins is more cost-effective compared to the double-pass solar collector without fins for mass flow rate of 0.01–0.07 kg/s. Also, simulations were obtained for the double-pass solar collector with fins at Nusselt number of 5.42–36.21. The energy efficiency of collector increases with the increase of Nusselt number. The results show that by increasing the Nusselt number simultaneously would drop the outlet temperature at any solar intensity. Increase in Nusselt number

  13. Cosmic dust investigations. Pt. 2

    International Nuclear Information System (INIS)

    Simpson, J.A.; Tuzzolino, A.J.

    1989-01-01

    A series of experiments have been completed using accelerator dust particles in the mass range ≅ 10 -9 -10 -6 g and velocity range ≅ 2-12 km/s to measure the velocity loss and degree of fragmentation for dust particles penetrating 6 and 28 μm thick polyvinylidene fluoride (PVDF) dust detectors. These measurements prove that even for a ratio of PVDF foil thickness to particle diameter as large as 0.6, the velocity loss and fragmentation is far less than expected from earlier reports in the literature. For 6 μm thick foils the velocity loss is ≤5%. These experiments are based on an extension of our earlier work which showed that two PVDF foils spaced a given distance apart could provide accurate time-of-flight (TOF) information due to the fast pulse rise time of PVDF detector response. We also report on our present state of development of PVDF position-sensing detectors which identify the x, y coordinates of particle impact, using detector and electronic pulse techniques adapted from our semiconductor position-sensing cosmic-ray detectors. Typical position errors of ≅ 1 mm are readily achieved. Finally, we have combined the above developments into a dust-particle telescope which accurately (≅ 1 0 angular accuracy) measures the trajectory of the incident particle as well as its mass and incident velocity, irrespective of whether it is a charged or neutral particle. We discuss how this practical dust telescope can be combined with dust capture cells for space flight and later recovery for laboratory determination of elemental and isotopic composition of captured dust. We also describe a simpler trajectory array based on discrete mosaics of thin detectors which would measure trajectories with a mean angular error of ≅ 4 0 . We discuss the application of these instruments for distinguishing between interplanetary dust of cometary and asteroidal origin, and for measurements on a space station, from near-Earth trapped dust of artificial origin. (orig.)

  14. Charged dust in saturn's magnetosphere

    International Nuclear Information System (INIS)

    Mendis, D.A.; Hill, J.R.; Houpis, H.L.F.

    1983-01-01

    Gravito-electrodynamic theory of charged dust grains is used to explain a variety of phenomena in those portions of the Saturnian ring system that are known to be dominated by fine (micron- and submicron-sized) dust, and in which collisional forces and Coulomb drag can be neglected. Among the phenomena discussed are the formation and evolution of the rotating near-radial spokes in the B-ring, the formation of waves in the F-ring, the cause of eccentricities of certain isolated ringlets, and the origin and morphology of the broad diffuse E-ring. Several novel processes predicted by the gravitoelectrodynamic theory, including 'magneto-gravitational capture' of exogenic dust by the magnetosphere, '1:1 magneto-gravitational orbital resonances' of charged dust with nearby satellites, and 'gyro-orbital resonances,' are used to explain individual observations. The effect of a ring current associated with this charged dust is also evaluated. Finally, the cosmogonic implications of the magneto-gravitational theory are briefly discussed. While several (although not all) of these processes have been discussed by one or more of the present authors elsewhere, the purpose of this paper is to synthesize all these processes within the framework of gravito-electrodynamics, and also to show its range of applicability within Saturn's ring system

  15. Spring Dust Storm Smothers Beijing

    Science.gov (United States)

    2002-01-01

    A few days earlier than usual, a large, dense plume of dust blew southward and eastward from the desert plains of Mongolia-quite smothering to the residents of Beijing. Citizens of northeastern China call this annual event the 'shachenbao,' or 'dust cloud tempest.' However, the tempest normally occurs during the spring time. The dust storm hit Beijing on Friday night, March 15, and began coating everything with a fine, pale brown layer of grit. The region is quite dry; a problem some believe has been exacerbated by decades of deforestation. According to Chinese government estimates, roughly 1 million tons of desert dust and sand blow into Beijing each year. This true-color image was made using two adjacent swaths (click to see the full image) of data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), flying aboard the OrbView-2 satellite, on March 17, 2002. The massive dust storm (brownish pixels) can easily be distinguished from clouds (bright white pixels) as it blows across northern Japan and eastward toward the open Pacific Ocean. The black regions are gaps between SeaWiFS' viewing swaths and represent areas where no data were collected. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  16. Physical properties of five grain dust types.

    Science.gov (United States)

    Parnell, C B; Jones, D D; Rutherford, R D; Goforth, K J

    1986-01-01

    Physical properties of grain dust derived from five grain types (soybean, rice, corn, wheat, and sorghum) were measured and reported. The grain dusts were obtained from dust collection systems of terminal grain handling facilities and were assumed to be representative of grain dust generated during the handling process. The physical properties reported were as follows: particle size distributions and surface area measurements using a Coulter Counter Model TAII; percent dust fractions less than 100 micron of whole dust; bulk density; particle density; and ash content. PMID:3709482

  17. An investigation on the performance characteristics of solar flat plate collector with different selective surface coatings

    Energy Technology Data Exchange (ETDEWEB)

    Madhukeshwara, N. [Department of Mechanical Engineering, B.I.E.T, Davanagere, Karnataka (India); Prakash, E.S. [Department of Studies in Mechanical Engineering, U.B.D.T.C.E, Davanagere, Karnataka (India)

    2012-07-01

    In the present work, investigations are made to study performance characteristics of solar flat plate collector with different selective surface coatings. Flat plate collector is one of the important solar energy trapping device which uses air or water as working fluid. Of the many solar collector concepts presently being developed, the relative simple flat plate solar collector has found the widest application so far. Its characteristics are known, and compared with other collector types, it is the easiest and least expensive to fabricate, install, and maintain. Moreover, it is capable of using both the diffuse and the direct beam solar radiation. For residential and commercial use, flat plate collectors can produce heat at sufficiently high temperatures to heat swimming pools, domestic hot water, and buildings; they also can operate a cooling unit, particularly if the incident sunlight is increased by the use of reflector. Temperatures up to 70 C are easily attained by flat plate collectors. With very careful engineering using special surfaces, reflectors to increase the incident radiation and heat resistant materials, higher operating temperatures are feasible.

  18. Development of a Solar Assisted Drying System Using Double-Pass Solar Collector with Finned Absorber

    Science.gov (United States)

    Azmi, M. S. M.; Othman, M. Y.; Sopian, K.; Ruslan, M. H.; Majid, Z. A. A.; Fudholi, A.; Yasin, J. M.

    2012-09-01

    The Solar Energy Research Group, Universiti Kebangsaan Malaysia, International Islamic University Malaysia and Yayasan FELDA has designed and constructed a solar assisted drying system at OPF FELDA Factory, Felda Bukit Sagu 2, Kuantan, Pahang. The drying system has a total of six double-pass solar collectors. Each collector has a length of 480 cm and a width of 120 cm. The first channel depth is 3.5 cm and the second channel depth is 7 cm. Longitudinal fins made of angle aluminium, 0.8 mm thickness were attached to the bottom surface of the absorber plate. The solar collectors are arranged as two banks of three collectors each in series. Internal manifold are used to connect the collectors. Air enters through the first channel and then through the second channel of the collector. An auxiliary heater source is installed to supply heat under unfavourable solar radiation condition. An on/off controller is used to control the startup and shutdown of the auxiliary heater. An outlet temperature of 70-75 °C can be achieved at solar radiation range of 800-900 W/m2 and flow rate of 0.12 kg/s. The average thermal efficiency of a solar collector is approximately 37%.

  19. Thin Film Energy Storage Device with Spray‐Coated Sliver Paste Current Collector

    Directory of Open Access Journals (Sweden)

    Seong Man Yoon

    2017-12-01

    Full Text Available This paper challenges the fabrication of a thin film energy storage device on a flexible polymer substrate specifically by replacing most commonly used metal foil current collectors with coated current collectors. Mass‐manufacturable spray‐coating technology enables the fabrication of two different half‐cell electric double layer capacitors (EDLC with a spray‐coated silver paste current collector and a Ni foil current collector. The larger specific capacitances of the half‐cell EDLC with the spray‐coated silver current collector are obtained as 103.86 F/g and 76.8 F/g for scan rates of 10 mV/s and 500 mV/s, respectively. Further, even though the half‐cell EDLC with the spray‐coated current collector is heavier than that with the Ni foil current collector, smaller Warburg impedance and contact resistance are characterized from Nyquist plots. For the applied voltages ranging from −0.5 V to 0.5 V, the spray‐coated thin film energy storage device exhibits a better performance.

  20. Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

    Science.gov (United States)

    Tecimer, M.; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J.

    2001-12-01

    A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 π mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design.

  1. Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

    Energy Technology Data Exchange (ETDEWEB)

    Tecimer, M. E-mail: tecimer@post.tau.ac.il; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J

    2001-12-21

    A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 {pi} mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design.

  2. Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

    International Nuclear Information System (INIS)

    Tecimer, M.; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J.

    2001-01-01

    A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 π mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design

  3. Development of a Solar Assisted Drying System Using Double-Pass Solar Collector with Finned Absorber

    International Nuclear Information System (INIS)

    Azmi, M S M; Sopian, K; Ruslan, M H; Fudholi, A; Majid, Z A A; Yasin, J M; Othman, M Y

    2012-01-01

    The Solar Energy Research Group, Universiti Kebangsaan Malaysia, International Islamic University Malaysia and Yayasan FELDA has designed and constructed a solar assisted drying system at OPF FELDA Factory, Felda Bukit Sagu 2, Kuantan, Pahang. The drying system has a total of six double-pass solar collectors. Each collector has a length of 480 cm and a width of 120 cm. The first channel depth is 3.5 cm and the second channel depth is 7 cm. Longitudinal fins made of angle aluminium, 0.8 mm thickness were attached to the bottom surface of the absorber plate. The solar collectors are arranged as two banks of three collectors each in series. Internal manifold are used to connect the collectors. Air enters through the first channel and then through the second channel of the collector. An auxiliary heater source is installed to supply heat under unfavourable solar radiation condition. An on/off controller is used to control the startup and shutdown of the auxiliary heater. An outlet temperature of 70–75 °C can be achieved at solar radiation range of 800–900 W/m 2 and flow rate of 0.12 kg/s. The average thermal efficiency of a solar collector is approximately 37%.

  4. Dual curvature acoustically damped concentrating collector. Semiannual technical progress report, June 1-December 1, 1978

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-12-01

    The project's first objective is to establish, analytically, the cost and performance of design choices within the boundaries of the basic proposed concept. With these cost and performance measures as a guide, the second project objective is to design a cost-effective Dual Curvature collector module and collector field array. The third objective is to establish technical and economic concept feasibility through prototype fabrication and test. The final objective is to define the Dual Curvature collector commercialization requirements. The Dual Curvature collector uses a unique reflector module consisting of a reflective film that is tensioned on a reflector support frame. The tensioned membrane (film) surface approximates a hyperbolic paraboloid that is capable of linear focusing when the surface tracks the sun's apparent motion in one axis. The reflective film can be backed by polystyrene foam with an air space between the film and the foam surfaces. This provides damping of the reflector surface to minimize the effect of wind gusts and physical impacts. The baseline collector is intended to operate at a concentration of ten (10) or greater with a nominal absorber temperature of 150/sup 0/C (300/sup 0/F). The Component Research and Analysis tasks which lead to the selection of a baseline collector configuration are discussed. Also, some preliminary results of the Collector Module Design task are presented.

  5. Electrochemical Properties of Current Collector in the All-vanadium Redox Flow Battery

    International Nuclear Information System (INIS)

    Hwang, Gan-Jin; Oh, Yong-Hwan; Ryu, Cheol-Hwi; Choi, Ho-Sang

    2014-01-01

    Two commercial carbon plates were evaluated as a current collector (bipolar plate) in the all vanadium redox-flow battery (V-RFB). The performance properties of V-RFB were test in the current density of 60 mA/cm 2 . The electromotive forces (OCV at SOC 100%) of V-RFB using A and B current collector were 1.47 V and 1.54 V. The cell resistance of V-RFB using A current collector was 4.44-5.00 Ω·cm 2 and 3.28-3.75 Ω·cm 2 for charge and discharge, respectively. The cell resistance of V-RFB using B current collector was 4.19-4.42Ω·cm 2 and 4.71-5.49Ω·cm 2 for charge and discharge, respectively. The performance of V-RFB using each current collector was evaluated. The performance of V-RFB using A current collector was 93.1%, 76.8% and 71.4% for average current efficiency, average voltage efficiency and average energy efficiency, respectively. The performance of V-RFB using B current collector was 96.4%, 73.6% and 71.0% for average current efficiency, average voltage efficiency and average energy efficiency, respectively

  6. Thermal performance of an open thermosyphon using nanofluid for evacuated tubular high temperature air solar collector

    International Nuclear Information System (INIS)

    Liu, Zhen-Hua; Hu, Ren-Lin; Lu, Lin; Zhao, Feng; Xiao, Hong-shen

    2013-01-01

    Highlights: • A novel solar air collector with simplified CPC and open thermosyphon is designed and tested. • Simplified CPC has a much lower cost at the expense of slight efficiency loss. • Nanofluid effectively improves thermal performance of the above solar air collector. • Solar air collector with open thermosyphon is better than that with concentric tube. - Abstract: A novel evacuated tubular solar air collector integrated with simplified CPC (compound parabolic concentrator) and special open thermosyphon using water based CuO nanofluid as the working fluid is designed to provide air with high and moderate temperature. The experimental system has two linked panels and each panel includes an evacuated tube, a simplified CPC and an open thermosyphon. Outdoor experimental study has been carried out to investigate the actual solar collecting performance of the designed system. Experimental results show that air outlet temperature and system collecting efficiency of the solar air collector using nanofluid as the open thermosyphon’s working fluid are both higher than that using water. Its maximum air outlet temperature exceeds 170 °C at the air volume rate of 7.6 m 3 /h in winter, even though the experimental system consists of only two collecting panels. The solar collecting performance of the solar collector integrated with open thermosyphon is also compared with that integrated with common concentric tube. Experimental results show that the solar collector integrated with open thermosyphon has a much better collecting performance

  7. Variation of reflected radiation from all reflectors of a flat plate solar collector during a year

    International Nuclear Information System (INIS)

    Pavlović, Zoran T.; Kostić, Ljiljana T.

    2015-01-01

    In this paper the impact of flat plate reflectors (bottom, top, left and right reflectors) made of Al, on total solar radiation on a solar collector during a day time over a whole year is analyzed. An analytical model for determining optimum tilt angles of a collector and reflectors for any point on the Earth is proposed. Variations of reflectors' optimal inclination angles with changes of the collector's optimal tilt angle during the year are also calculated. Optimal inclination angles of the reflectors for the South directed solar collector are calculated and compared to experimental data. It is shown that optimal inclination of the bottom reflector is the lowest in December and the highest in June, while for the top reflector the lowest value is in June and the highest value is in December. On the other hand, optimal inclination of the left and right side reflectors for optimum tilt angle of the collector does not change during the year and it is 66°. It is found that intensity of the solar radiation on the collector increases for about 80% in the summer period (June–September) by using optimally inclined reflectors, in comparison to the collector without reflectors. - Highlights: • The impacts of flat plate reflectors on solar radiation on the collector are given. • The results of the optimal inclinations of reflectors during the year are shown. • The solar radiation on the collector with reflectors is 80% higher in the summer. • This model may be applied on thermal, PV, PV/T and energy harvesting systems

  8. Glass Frit Clumping And Dusting

    International Nuclear Information System (INIS)

    Steimke, J. L.

    2013-01-01

    DWPF mixes a slurry of glass frit (Frit 418) and dilute (1.5 wt%) formic acid solution with high level waste in the Slurry Mix Evaporator (SME). There would be advantages to introducing the frit in a non-slurry form to minimize water addition to the SME, however, adding completely dry frit has the potential to generate dust which could clog filters or condensers. Prior testing with another type of frit, Frit 320, and using a minimal amount of water reduced dust generation, however, the formation of hard clumps was observed. To examine options and behavior, a TTQAP [McCabe and Stone, 2013] was written to initiate tests that would address these concerns. Tests were conducted with four types of glass frit; Frit 320, DWPF Frit 418, Bekeson Frit 418 and Multi-Aspirator Frit 418. The last two frits are chemically identical to DWPF Frit 418 but smaller particles were removed by the respective vendors. Test results on Frit Clumping and Dusting are provided in this report. This report addresses the following seven questions. Short answers are provided below with more detailed answers to follow. 1. Will the addition of a small amount of water, 1.5 wt%, to dry DWPF Frit 418 greatly reduce the dust generation during handling at DWPF? a. Yes, a small scale test showed that adding a little water to the frit greatly reduced dust generation during handling. 2. Will the addition of small amounts of water to the frit cause clumping that will impair frit handling at DWPF? a. No, not with Frit 418. Although clumps were observed to form when 1.5 wt% water was mixed with DWPF Frit 418, then compressed and air-dried overnight, the clumps were easily crushed and did not form the hardened material noted when Frit 320 was tested. 3. What is the measured size distribution of dust generated when dry frit is handled? (This affects the feasibility and choice of processing equipment for removing the dust generating fraction of the frit before it is added to the SME.) a. The size distribution for

  9. Glass Frit Clumping And Dusting

    Energy Technology Data Exchange (ETDEWEB)

    Steimke, J. L.

    2013-09-26

    DWPF mixes a slurry of glass frit (Frit 418) and dilute (1.5 wt%) formic acid solution with high level waste in the Slurry Mix Evaporator (SME). There would be advantages to introducing the frit in a non-slurry form to minimize water addition to the SME, however, adding completely dry frit has the potential to generate dust which could clog filters or condensers. Prior testing with another type of frit, Frit 320, and using a minimal amount of water reduced dust generation, however, the formation of hard clumps was observed. To examine options and behavior, a TTQAP [McCabe and Stone, 2013] was written to initiate tests that would address these concerns. Tests were conducted with four types of glass frit; Frit 320, DWPF Frit 418, Bekeson Frit 418 and Multi-Aspirator Frit 418. The last two frits are chemically identical to DWPF Frit 418 but smaller particles were removed by the respective vendors. Test results on Frit Clumping and Dusting are provided in this report. This report addresses the following seven questions. Short answers are provided below with more detailed answers to follow. 1. Will the addition of a small amount of water, 1.5 wt%, to dry DWPF Frit 418 greatly reduce the dust generation during handling at DWPF? a. Yes, a small scale test showed that adding a little water to the frit greatly reduced dust generation during handling. 2. Will the addition of small amounts of water to the frit cause clumping that will impair frit handling at DWPF? a. No, not with Frit 418. Although clumps were observed to form when 1.5 wt% water was mixed with DWPF Frit 418, then compressed and air-dried overnight, the clumps were easily crushed and did not form the hardened material noted when Frit 320 was tested. 3. What is the measured size distribution of dust generated when dry frit is handled? (This affects the feasibility and choice of processing equipment for removing the dust generating fraction of the frit before it is added to the SME.) a. The size distribution for

  10. Dust deposit in recirculation regions

    International Nuclear Information System (INIS)

    Griemert, R.

    1985-03-01

    The present report shows investigations, which have been carried out in a closed duct at forward and backward facing steps. Distribution of fluid velocity and fluid fluctuations in and normal to main flow direction as well as the distribution of Reynolds shear stress have been measured. The mass transfer downstream of a backward facing step has been investigated as well. By using graphite-, copper-, tin- and rubber dust, conditions of deposition have been defined experimentally. A serie of photos shows the filling of a recirculation region downstream of a backward facing step with graphite dust. The present investigations allow to avoid deposition of dust in recirculation regions by selecting the fluid numbers in an appropriate way. (orig.) [de

  11. Dust Storm Hits Canary Islands

    Science.gov (United States)

    2002-01-01

    A thick pall of sand and dust blew out from the Sahara Desert over the Atlantic Ocean yesterday (January 6, 2002), engulfing the Canary Islands in what has become one of the worst sand storms ever recorded there. In this scene, notice how the dust appears particularly thick in the downwind wake of Tenerife, the largest of the Canary Islands. Perhaps the turbulence generated by the air currents flowing past the island's volcanic peaks is churning the dust back up into the atmosphere, rather than allowing it to settle toward the surface. This true-color image was captured by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite, on January 7, 2002. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  12. Mechanisms of metal dusting corrosion

    DEFF Research Database (Denmark)

    Hummelshøj, Thomas Strabo

    In this thesis the early stages of metal dusting corrosion is addressed; the development of carbon expanded austenite, C, and the decomposition hereof into carbides. Later stages of metal dusting corrosion are explored by a systematic study of stainless steel foils exposed to metal dusting...... deformed stainless steel flakes is transformed to expanded martensite/austenite during low-temperature carburization. Various experimental procedures to experimentally determine the concentration dependent diffusion coefficient of carbon in expanded austenite are evaluated. The most promising procedure...... powders and flakes. The nature of the decomposition products, carbides of the form M23C6 and M7C3, were evaluated by X-ray diffraction, light optical microscopy, scanning electron microscopy and thermodynamic modelling. The decomposition was found to be dependent on several parameters such as thermal...

  13. The effect of coupling a flat-plat collector on the solar still productivity

    International Nuclear Information System (INIS)

    Badran, O. O.; Al-Tahaineh, H. A.

    2006-01-01

    Experimental investigation to study the effect of coupling a flat plate solar collector on the productivity of solar stills was carried out. Other different parameters (i.e. water depth, direction of still, solar radiation) to enhance the productivity were also studied. Single slope solar still with mirrors fixed to its interior sides was coupled with a flat plate collector. It has been found that coupling of a solar collector with a still has increased the productivity by 56%. Also the increase of water depth has decreased the productivity, while the still productivity is found to be proportional to the solar radiation intensity.(Author)

  14. Thermal-hydraulics of PGV-4 water volume during damage of the feedwater collector nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Logvinov, S.A.; Titov, V.F. [OKB Gidropress (Russian Federation); Notaros, U.; Lenkei, I. [NPP Paks (Hungary)

    1995-12-31

    A number of VVER-440 plants has experienced the distributing nozzles of feedwater collector being damaged due to corrosion-erosion wearing. Such phenomenon could result in feedwater redistribution within the SG inventory with undesirable consequences. The collector with damaged nozzles has to be replaced but a certain time is needed for the preparatory works. The main objective of the investigation conducted is to assess if the safe operation of SG is possible before collector replacement. It was shown that the nozzle damage as observed did not result in the dangerous disturbances of thermobydraulics as compared with the conditions existing at the initial period of operation. (orig.).

  15. The EIR-programmes for computing the gross heat output of solar collectors (MURD and ETA)

    International Nuclear Information System (INIS)

    Widder, F.

    1980-11-01

    For the computation of the gross heat output of solar collectors by means of meteo data and characteristic collector parameters two programs were developed: MURD for the determination of the ''mean usable radiation density'' and ETA for the calculation of the collector efficiency i.e. relative values of gross heat output. The main features of these programs are described and detailed instructions for the use of them are given. Results of some cases for the meteo-situation of Zurich airport are given. (Auth.)

  16. An Experimental and Analytical Study of a Radiative Cooling System with Unglazed Flat Plate Collectors

    DEFF Research Database (Denmark)

    Hosseinzadeh, Elham; Taherian, Hessam

    2012-01-01

    plate solar collectors in a humid area, Babol, Iran, is assessed both experimentally and numerically. Different methods available in the literature are reviewed and by using a widely accepted model, the sky temperature is determined. The mathematical model for a flat plate solar collector is used...... as a guideline to derive the governing equations of a night sky radiator. Then, a cooling loop, including a storage tank, pump, connecting pipes, and a radiator has been studied experimentally. The water is circulated through the unglazed flat-plate radiator having 4 m2 of collector area at night to be cooled...

  17. Theory and experimental study of biased charge collector for measuring HPIB

    International Nuclear Information System (INIS)

    He Xiaoping; Wang Haiyang; Sun Jianfeng; Yang Hailiang; Qiu Aici; Tang Junping; Li Jingya; Li Hongyu

    2004-01-01

    Structure of the biased charge collector for measuring HPIB (High-power ion beam) is introduced in this paper. The inner charge propagation process of HPIB in the biased charge collector was simulated with KARAT PIC code. The simulation results indicated that charge was neutralized but current was not neutralized in the biased charge collector. The influence of biased voltage and aperture diameter were also simulated. A -800V biased voltage can meet the requirement for measuring 500 keV HPIB, and this is consistent with the experimental results

  18. Thermal-hydraulics of PGV-4 water volume during damage of the feedwater collector nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Logvinov, S A; Titov, V F [OKB Gidropress (Russian Federation); Notaros, U; Lenkei, I [NPP Paks (Hungary)

    1996-12-31

    A number of VVER-440 plants has experienced the distributing nozzles of feedwater collector being damaged due to corrosion-erosion wearing. Such phenomenon could result in feedwater redistribution within the SG inventory with undesirable consequences. The collector with damaged nozzles has to be replaced but a certain time is needed for the preparatory works. The main objective of the investigation conducted is to assess if the safe operation of SG is possible before collector replacement. It was shown that the nozzle damage as observed did not result in the dangerous disturbances of thermobydraulics as compared with the conditions existing at the initial period of operation. (orig.).

  19. Thermal performance of a double-pass solar collector with porous media

    International Nuclear Information System (INIS)

    Elradi A Musa; Kamaruzzaman Sopian; Shahrir Abdullah

    2006-01-01

    Thermal performance of a double-pass solar collector has been developed for air following through the porous media. The porous media are arranged in different porosities to increase heat transfer, area density and the total heat transfer rate. A test collector was developed and tested indoors by varying the design features and operating conditions using a halogen-lamp simulator as a radiation source. An experimental setup as been designed and constructed. Comparisons of the theoretical and the experimental result have been conducted. This type of collector can be used for drying and heat applications such as solar industrial processes, space and solar drying of agricultural products

  20. Object-oriented simulation model of a parabolic trough solar collector: Static and dynamic validation

    Science.gov (United States)

    Ubieta, Eduardo; Hoyo, Itzal del; Valenzuela, Loreto; Lopez-Martín, Rafael; Peña, Víctor de la; López, Susana

    2017-06-01

    A simulation model of a parabolic-trough solar collector developed in Modelica® language is calibrated and validated. The calibration is performed in order to approximate the behavior of the solar collector model to a real one due to the uncertainty in some of the system parameters, i.e. measured data is used during the calibration process. Afterwards, the validation of this calibrated model is done. During the validation, the results obtained from the model are compared to the ones obtained during real operation in a collector from the Plataforma Solar de Almeria (PSA).

  1. Recent Optical and SEM Characterization of Genesis Solar Wind Concentrator Diamond on Silicon Collector

    Science.gov (United States)

    Allton, Judith H.; Rodriquez, M. C.; Burkett, P. J.; Ross, D. K.; Gonzalez, C. P.; McNamara, K. M.

    2013-01-01

    One of the 4 Genesis solar wind concentrator collectors was a silicon substrate coated with diamond-like carbon (DLC) in which to capture solar wind. This material was designed for analysis of solar nitrogen and noble gases [1, 2]. This particular collector fractured during landing, but about 80% of the surface was recovered, including a large piece which was subdivided in 2012 [3, 4, 5]. The optical and SEM imaging and analysis described below supports the subdivision and allocation of the diamond-on-silicon (DOS) concentrator collector.

  2. A Review on Photovoltaic-Thermal (PV-T) Air and Water Collectors

    International Nuclear Information System (INIS)

    Avezov, R.R.; Akhatov, J. S.; Avezova, N. R.

    2011-01-01

    This paper presents the state-of-the-art on photovoltaic-thermal PV-T collectors. There are presented two main classification groups: -Air and -Water PV-Thermal collectors, design and performance evaluation, comparison of the findings obtained by various researchers. The review also covers the description of different designs of air and water PV-T collectors, the results of theoretical and experimental works, focused to optimization of the technical and economical performances in terms of electrical as well as thermal outputs. (authors)

  3. Mathematical modeling of photovoltaic thermal PV/T system with v-groove collector

    Science.gov (United States)

    Zohri, M.; Fudholi, A.; Ruslan, M. H.; Sopian, K.

    2017-07-01

    The use of v-groove in solar collector has a higher thermal efficiency in references. Dropping the working heat of photovoltaic panel was able to raise the electrical efficiency performance. Electrical and thermal efficiency were produced by photovoltaic thermal (PV/T) system concurrently. Mathematical modeling based on steady-state thermal analysis of PV/T system with v-groove was conducted. With matrix inversion method, the energy balance equations are explained by means of the investigative method. The comparison results show that in the PV/T system with the V-groove collector is higher temperature, thermal and electrical efficiency than other collectors.

  4. Multi-element RIMS Analysis of Genesis Solar Wind Collectors

    Science.gov (United States)

    Veryovkin, I. V.; Tripa, C. E.; Zinovev, A. V.; King, B. V.; Pellin, M. J.; Burnett, D. S.

    2009-12-01

    The samples of Solar Wind (SW) delivered by the NASA Genesis mission, present significant challenges for surface analytical techniques, in part due to severe terrestrial contamination of the samples on reentry, in part due to the ultra-shallow and diffused ion implants in the SW collector materials. We are performing measurements of metallic elements in the Genesis collectors using Resonance Ionization Mass Spectrometry (RIMS), an ultra-sensitive analytical method capable of detecting SW in samples with lateral dimensions of only a few mm and at concentrations from above one ppm to below one ppt. Since our last report at 2008 AGU Fall Meeting, we have (a) developed and tested new resonance ionization schemes permitting simultaneous measurements of up to three (Ca, Cr, and Mg) elements, and (b) improved reproducibility and accuracy of our RIMS analyses for SW-like samples (i.e. shallow ion implants) by developing and implementing an optimized set of new analytical protocols. This is important since the quality of scientific results from the Genesis mission critically depends on the accuracy of analytical techniques. In this work, we report on simultaneous RIMS measurements of Ca and Cr performed on two silicon SW collector samples, (#60179 and #60476). First, we have conducted test experiments with 3×1013 at/cm2 52Cr and 44Ca implants in silicon to evaluate the accuracy of our quantitative analyses. Implant fluencies were measured by RIMS to be 2.73×1013 and 2.71×1013 at/cm2 for 52Cr and 44Ca, respectively, which corresponds to an accuracy of ≈10%. Using the same implanted wafer as a reference, we conducted RIMS analyses of the Genesis samples: 3 spots on #60179 and 4 spots on #60476. The elemental SW fluencies expected for Cr and Ca are 2.95×1010 and 1.33×1011 at/cm2 , respectively. Our measurements of 52Cr yielded 3.0±0.6×1011 at/cm2 and 5.1±4.1×1010 at/cm2 for #60179 and #60476, respectively. For 40Ca, SW fluencies of 1.39±0.70×1011 at/cm2 in #60179

  5. Intergalactic dust and quasar distribution

    International Nuclear Information System (INIS)

    Soltan, A.

    1979-01-01

    Non-homogeneous intergalactic extinction may considerably affect the quasar distribution. Especially samples of quasars isolated on the basis of B-V colours are subject to this phenomenon. Apparent grouping and close pairs of quasars reported in the literature may be a result of intergalactic dust. Using surface distribution of faint blue objects selected by Hawkins and Reddish it is estimated that intergalactic extinction in B should reach approximately 1 mag out to the redshift of approximately 1. This is slightly larger than predicted by theory and comparable to the mean dust density derived from observations. (Author)

  6. The distribution of interstellar dust

    International Nuclear Information System (INIS)

    Clocchiatti, A.; Marraco, H.G.

    1986-01-01

    We propose the interstellar matter structural function as a tool to derive the features of the interstellar dust distribution. We study that function resolving some ideal dust distribution models. Later we describe the method used to find a reliable computing algorithm for the observational case. Finally, we describe the steps to build a model for the interstellar matter composed by spherically symmetrical clouds. The density distribution for each of these clouds is D(r) = D 0 .esup(-r/r 0 ) 2 . The preliminary results obtained are summarised. (author)

  7. Development of a selective thin film and of a hermetically sealed flat plate solar collector with gas filling

    Science.gov (United States)

    Zernial, W.

    1982-12-01

    The industrial productibility of a selective absorbing thin film was investigated on the basis of reactive cathodic sputtering of Ni. On substrates of 1.8 sq m of Al, Cu, steel and stainless steel, solar absorption values up to 97% were achieved at emissivities of 5 to 10%. A prototype flat plate collector for high temperatures with two covers and hermetical sealing was developed. The technical data of the collector were measured, dependent on the selectivity of the absorber, gas fillings of dry air, argon or SF6 and the geometry and were compared with those of an evacuated flat plate collector. A hermetical sealed double flat plate collector for low temperatures was developed which has the advantage of lower no load temperatures and higher energy gain for heating swimming pool water compared with a conventional flat plate collector. The insolation values on collectors were measured and were used for a calculation of the energy gains of different collector types.

  8. Virtual testing of speed reduction schemes on urban collector roads.

    Science.gov (United States)

    Domenichini, Lorenzo; Branzi, Valentina; Meocci, Monica

    2018-01-01

    Urban collector roads are complex driving environments often encompassing both the mobility and the access road functions. In these conditions motorized traffic and vulnerable road users compete continually. Speed reduction measures may play a relevant role in these contexts, provided that such measures are also designed in compliance with the driver's capabilities and expectations. The paper describes a test procedure using driving simulation experiments, designed to evaluate the reconfiguration project of Via Pistoiese, an urban road collector located in Florence (Italy). The road improvement design consisted of several engineering treatments aimed to reduce and homogenize the driving speed, as well as to manage the co-existence of the different road users and mainly to protect pedestrians. The main focus of the research was to understand if the drivers' behaviour was according to the design hypothesis before the safety treatments are implemented in the real world. Due to the multiple engineering treatments included in the reconfiguration project, the evaluation of the overall safety effectiveness of the project rather than the single treatment safety impact was the main concern of the research study. In addition, the study aimed to assess the usefulness of the considered testing method to understand how to integrate road design with drivers' performances, especially in heterogeneous traffic environments where drivers' behaviour plays a decisive role in the success of the proposed design solutions. Fifty-eight participants drove through two immersive virtual environments, reproducing the existing configuration and the project reconfiguration, while data relating to different driving aspects were collected. Two analyses were performed. The first was focused on the analysis of the mean speed profiles and revealed that the considered engineering treatments are able to control the speeding behaviour without providing a too high discomfort to the drivers. The second

  9. Electrostatic Dust Detector with Improved Sensitivity

    International Nuclear Information System (INIS)

    Boyle, D.P.; Skinner, C.H.; Roquemore, A.L.

    2008-01-01

    Methods to measure the inventory of dust particles and to remove dust if it approaches safety limits will be required in next-step tokamaks such as ITER. An electrostatic dust detector, based on a fine grid of interlocking circuit traces, biased to 30 or 50 V, has been developed for the detection of dust on remote surfaces in air and vacuum environments. Gaining operational experience of dust detection on surfaces in tokamaks is important, however the level of dust generated in contemporary short-pulse tokamaks is comparatively low and high sensitivity is necessary to measure dust on a shot-by-shot basis. We report on modifications in the detection electronics that have increased the sensitivity of the electrostatic dust detector by a factor of up to 120, - a level suitable for measurements on contemporary tokamaks.

  10. Infrared Observations of Cometary Dust and Nuclei

    Science.gov (United States)

    Lisse, Carey

    2004-01-01

    This bibliography lists citations for publications published under the grant. Subjects of the publications include cometary dust, instellar and interplanetary dust, comet nuclei and comae, Comet Hale-Bopp, infrared observations of comets, mass loss, and comet break-up.

  11. The global distribution of mineral dust

    International Nuclear Information System (INIS)

    Tegen, I; Schepanski, K

    2009-01-01

    Dust aerosol particles produced by wind erosion in arid and semi arid regions affect climate and air quality, but the magnitude of these effects is largely unquantified. The major dust source regions include the Sahara, the Arabian and Asian deserts; global annual dust emissions are currently estimated to range between 1000 and 3000 Mt/yr. Dust aerosol can be transported over long distances of thousands of kilometers, e.g. from source regions in the Saharan desert over the North Atlantic, or from the Asian deserts towards the Pacific Ocean. The atmospheric dust load varies considerably on different timescales. While dust aerosol distribution and dust effects are important on global scales, they strongly depend on dust emissions that are controlled on small spatial and temporal scales.

  12. Oxygen Isotopes in Chondritic Interplanetary Dust: Parent-Bodies and Nebular Oxygen Reservoirs

    International Nuclear Information System (INIS)

    Aleon, J; McKeegan, K D; Leshin, L

    2006-01-01

    Planetary objects have preserved various amounts of oxygen issued from isotopically different oxygen reservoirs reflecting their origin and physico-chemical history. An 16 O-rich component is preserved in refractory inclusions (CAIs) whereas meteorites matrices are enriched in an 16 O-poor component. The origin of these components is still unclear. The most recent models are based on isotope selective photodissociation of CO in a 16 O-rich nebula/presolr cloud resulting in a 16 O-poor gas in the outer part of the nebula. However because most meteorite components are thought to be formed in the inner 3AU of the solar nebula, the precise isotopic composition of outer solar system components is yet unknown. In that respect, the oxygen isotopic composition of cometary dust is a key to understand the origin of the solar system. The Stardust mission will bring back to the Earth dust samples from comet Wild2, a short period comet from the Jupiter family. A precise determination of the oxygen isotope composition of Wild2 dust grains is essential to decipher the oxygen reservoirs of the outer solar system. However, Stardust samples may be extremely fragmented upon impact in the collector. In addition, interplanetary dust particles (IDPs) collected in the stratosphere are likely to contain comet samples. Therefore, they started to investigate the oxygen isotopic composition of a suite of chondritic interplanetary dust particles that includes IDPs of potential cometary origin using a refined procedure to increase the lateral resolution for the analysis of Stardust grains or IDP subcomponents down to ∼ 3 (micro)m. High precision data for 4 IDPs were previously reported, here they have measured 6 additional IDPs

  13. SEM-EDS Analyses of Small Craters in Stardust Aluminum Foils: Implications for the Wild-2 Dust Distribution

    Science.gov (United States)

    Borg, J.; Horz, F.; Bridges, J. C.; Burchell, M. J.; Djouadi, Z.; Floss, C.; Graham, G. A.; Green, S. F.; Heck, P. R.; Hoppe, P.; hide

    2007-01-01

    Aluminium foils were used on Stardust to stabilize the aerogel specimens in the modular collector tray. Part of these foils were fully exposed to the flux of cometary grains emanating from Wild 2. Because the exposed part of these foils had to be harvested before extraction of the aerogel, numerous foil strips some 1.7 mm wide and 13 or 33 mm long were generated during Stardusts's Preliminary Examination (PE). These strips are readily accommodated in their entirety in the sample chambers of modern SEMs, thus providing the opportunity to characterize in situ the size distribution and residue composition - employing EDS methods - of statistically more significant numbers of cometary dust particles compared to aerogel, the latter mandating extensive sample preparation. We describe here the analysis of nearly 300 impact craters and their implications for Wild 2 dust.

  14. Exact solutions for rotating charged dust

    International Nuclear Information System (INIS)

    Islam, J.N.

    1984-01-01

    Earlier work by the author on rotating charged dust is summarized. An incomplete class of exact solutions for differentially rotating charged dust in Newton-Maxwell theory for the equal mass and charge case that was found earlier is completed. A new global exact solution for cylindrically symmetric differentially rotating charged dust in Newton-Maxwell theory is presented. Lastly, a new exact solution for cylindrically symmetric rigidly rotating charged dust in general relativity is given. (author)

  15. Studies of dust shells around stars

    International Nuclear Information System (INIS)

    Bedijn, P.J.

    1977-01-01

    This thesis deals with some aspects of circumstellar dust shells. This dust shell, emitting infrared radiation, is described by way of its absorptive and emissive properties as well as by the transfer of radiation through the dust shell itself. Model calculations are compared to experimental results and agree reasonably well. The author also discusses the dynamics of the extended shells of gas and dust around newly formed stars

  16. Radio frequency discharge with dust particles

    NARCIS (Netherlands)

    Chutov, Y. I.; W. J. Goedheer,; Kravchenko, O. Y.; Zuz, V. M.; Yan, M.; Martins, R.; Ferreira, I.; Fortunato, E.; Kroesen, G.

    2000-01-01

    A 1D PIC/MCC method has been developed for computer simulations of low-pressure RF discharges with dust particles using the method for dust-free discharges. A RF discharge in argon with dust particles distributed uniformly in the interelectrode gap is simulated at parameters providing a possibility

  17. Thirteen years of Aeolian dust dynamics in a desert region (Negev desert, Israel): analysis of horizontal and vertical dust flux, vertical dust distribution and dust grain size

    NARCIS (Netherlands)

    Offer, Z.Y.; Goossens, D.

    2004-01-01

    At Sede Boqer (northern Negev desert, Israel), aeolian dust dynamics have been measured during the period 1988–2000. This study focuses on temporal records of the vertical and horizontal dust flux, the vertical distribution of the dust particles in the atmosphere, and the grain size of the

  18. Dust Measurements Onboard the Deep Space Gateway

    Science.gov (United States)

    Horanyi, M.; Kempf, S.; Malaspina, D.; Poppe, A.; Srama, R.; Sternovsky, Z.; Szalay, J.

    2018-02-01

    A dust instrument onboard the Deep Space Gateway will revolutionize our understanding of the dust environment at 1 AU, help our understanding of the evolution of the solar system, and improve dust hazard models for the safety of crewed and robotic missions.

  19. Properties of interstellar dust in reflection nebulae

    International Nuclear Information System (INIS)

    Sellgren, K.

    1988-01-01

    Observations of interstellar dust in reflection nebulae are the closest analog in the interstellar medium to studies of cometary dust in our solar system. The presence of a bright star near the reflection nebula dust provides the opportunity to study both the reflection and emission characteristics of interstellar dust. At 0.1 to 1 micrometer, the reflection nebula emission is due to starlight scattered by dust. The albedo and scattering phase function of the dust is determined from observations of the scattered light. At 50 to 200 micrometers, thermal emission from the dust in equilibrium with the stellar radiation field is observed. The derived dust temperature determines the relative values of the absorption coefficient of the dust at wavelengths where the stellar energy is absorbed and at far infrared wavelengths where the absorbed energy is reradiated. These emission mechanisms directly relate to those seen in the near and mid infrared spectra of comets. In a reflection nebula the dust is observed at much larger distances from the star than in our solar system, so that the equilibrium dust temperature is 50 K rather than 300 K. Thus, in reflection nebulae, thermal emission from dust is emitted at 50 to 200 micrometer

  20. House dust extracts contain potent immunological adjuvants

    NARCIS (Netherlands)

    Beukelman, C.J.; Dijk, H. van; Aerts, P.C.; Rademaker, P.M.; Berrens, L.; Willers, J.M.N.

    1987-01-01

    A crude aqueous extract of house dust and two house dust subfractions were tested for adjuvant activity in a sensitivity assay performed in mice. Evidence is presented that house dust contains at least two potent immunological adjuvants. One of these, present in both subfractions, was probably