WorldWideScience

Sample records for adsorbed unsaturated collector

  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. 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)

  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. 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

  8. 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.

  9. Separation of Co(II) from dilute aqueous solutions by precipitate and adsorbing colloid flotation

    International Nuclear Information System (INIS)

    Aziz, M.; Benyamin, K.; Shakir, K.; Atomic Energy Establishment, Cairo

    1993-01-01

    Ion, precipitate and adsorbing colloid flotation of cobalt(II) have been investigated at different pH values, using N-dodecylpyridinium chloride (DPCl). A strong cationic surfactant, and sodium lauryl sulfate (NaLS), a strong anionic surfactant, as collectors. In case of adsorbing colloid flotation, hydrous manganese dioxide was used as an adsorbent. The precipitate flotation curves experimentally obtained with the two tested collectors were compared with the corresponding theoretical one calculated from the data published for Co(II) hydrolysis. The effects of the collector concentration, ageing of the water-MnO 2 -Co(II) system, bubbling time period, cobalt(II) concentration and foreign salts on the percent removal of Co(II) by adsorbing colloid flotation using DPCl as collector were determined. Removals approaching 100% could be achieved under the optimum conditions. (author) 44 refs.; 6 figs

  10. 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.

  11. 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.

  12. 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.

  13. Adsorber fires

    International Nuclear Information System (INIS)

    Holmes, W.

    1987-01-01

    The following conclusions are offered with respect to activated charcoal filter systems in nuclear power plants: (1) The use of activated charcoal in nuclear facilities presents a potential for deep-seated fires. (2) The defense-in-depth approach to nuclear fire safety requires that if an ignition should occur, fires must be detected quickly and subsequently suppressed. (3) Deep-seated fires in charcoal beds are difficult to extinguish. (4) Automatic water sprays can be used to extinguish fires rapidly and reliably when properly introduced into the burning medium. The second part of the conclusions offered are more like challenges: (1) The problem associated with inadvertent actuations of fire protection systems is not a major one, and it can be reduced further by proper design review, installation, testing, and maintenance. Eliminating automatic fire extinguishing systems for the protection of charcoal adsorbers is not justified. (2) Removal of automatic fire protection systems due to fear of inadvertent fire protection system operation is a case of treating the effect rather than the cause. On the other hand, properly maintaining automatic fire protection systems will preserve the risk of fire loss at acceptable levels while at the same time reducing the risk of damage presented by inadvertent operation of fire protection systems

  14. 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

  15. 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.

  16. 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.

  17. Design, construction and test run of a solid adsorption solar refrigerator using activated carbon/methanol, as adsorbent/adsorbate pair

    International Nuclear Information System (INIS)

    Anyanwu, E.E.; Ezekwe, C.I.

    2003-01-01

    The design, construction and test run of a solid adsorption solar refrigerator are presented. It used activated carbon/methanol as the adsorbent/adsorbate pair. The refrigerator has three major components: collector/generator/adsorber, condenser and evaporator. Its flat plate type collector/generator/adsorber used clear plane glass sheet of effective exposed area of 1.2 m 2 . The steel condenser tube with a square plan view was immersed in pool of stagnant water contained in a reinforced sandcrete tank. The evaporator is a spirally coiled copper tube immersed in stagnant water. Adsorbent cooling during the adsorption process is both by natural convection of air over the collector plate and tubes and night sky radiation facilitated by removing the collector box end cover plates. Ambient temperatures during the adsorbate generation and adsorption process varied over 18.5-34 deg. C. The refrigerator yielded evaporator temperatures ranging over 1.0-8.5 deg. C from water initially in the temperature range 24-28 deg. C. Accordingly, the maximum daily useful cooling produced was 266.8 kJ/m 2 of collector area

  18. Modelling flow through unsaturated zones: Sensitivity to unsaturated ...

    Indian Academy of Sciences (India)

    M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

    soil properties are studied by varying the unsaturated parameters α and n over a wide range. ... Keywords. Unsaturated zone; capillary fringe; finite element method. ... and radioactive wastes. Several .... The length (L) of the soil sample is 1 m.

  19. Infiltration in Unsaturated Soils

    DEFF Research Database (Denmark)

    Ghotbi, Abdoul R.; Omidvar, M.; Barari, Amin

    2011-01-01

    An approximate analytical solution has been established for the well known Richards’ equation for unsaturated flow of transports in soils. Despite the importance of Richards’ equation in geotechnical and geoenvironmental applications, most solutions to the problem are generally based on numerical...

  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. Dissolved Air Flotation of arsenic adsorbent particles

    Directory of Open Access Journals (Sweden)

    Mario Enrique Santander Muñoz

    2015-01-01

    Full Text Available The removal of arsenic from synthetic effluent was studied using the adsorbent particle flotation technique (APF and dissolved air flotation (DAF. A sample of an iron mineral was used as adsorbent particles of arsenic, ferric chloride as coagulant, cationic poly-acrylamide (NALCO 9808 as flocculants, and sodium oleate as collector. Adsorption studies to determine the pH influence, contact time, and adsorbent particles concentration on the adsorption of arsenic were carried out along with flotation studies to determine the removal efficiency of adsorbents particles. The results achieved indicate that the adsorption kinetic of arsenic is very rapid and that in range of pH’s from 2 to 7 the adsorption percentages remain constant. The equilibrium conditions were achieved in 60 minutes and about 95% of arsenic was adsorbed when used an adsorbent concentration of 2 g/L and pH 6.3. The maximum adsorption capacity of adsorbent particles was 4.96 mg/g. The mean free energy of adsorption (E was found to be 2.63 kJ/mol, which suggests physisorption. The results of the flotation studies demonstrated that when synthetic effluents with 8.9 mg/L of arsenic were treated under the following experimental conditions; 2 g/L of adsorbent particles, 120 mg/L of Fe(III, 2 mg/L of Nalco 9808, 20 mg/L of sodium oleate, and 40% of recycle ratio in the DAF, it was possible to reach 98% of arsenic removal and 6.3 NTU of residual turbidity in clarified synthetic effluent.

  2. 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.

  3. 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.

  4. 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.)

  5. 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.

  6. 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...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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)

  12. Modeling adsorption: Investigating adsorbate and adsorbent properties

    Science.gov (United States)

    Webster, Charles Edwin

    1999-12-01

    Surface catalyzed reactions play a major role in current chemical production technology. Currently, 90% of all chemicals are produced by heterogeneously catalyzed reactions. Most of these catalyzed reactions involve adsorption, concentrating the substrate(s) (the adsorbate) on the surface of the solid (the adsorbent). Pore volumes, accessible surface areas, and the thermodynamics of adsorption are essential in the understanding of solid surface characteristics fundamental to catalyst and adsorbent screening and selection. Molecular properties such as molecular volumes and projected molecular areas are needed in order to convert moles adsorbed to surface volumes and areas. Generally, these molecular properties have been estimated from bulk properties, but many assumptions are required. As a result, different literature values are employed for these essential molecular properties. Calculated molar volumes and excluded molecular areas are determined and tabulated for a variety of molecules. Molecular dimensions of molecules are important in the understanding of molecular exclusion as well as size and shape selectivity, diffusion, and adsorbent selection. Molecular dimensions can also be used in the determination of the effective catalytic pore size of a catalyst. Adsorption isotherms, on zeolites, (crystalline mineral oxides) and amorphous solids, can be analyzed with the Multiple Equilibrium Analysis (MEA) description of adsorption. The MEA produces equilibrium constants (Ki), capacities (ni), and thermodynamic parameters (enthalpies, ΔHi, and entropies, ΔSi) of adsorption for each process. Pore volumes and accessible surface areas are calculated from the process capacities. Adsorption isotherms can also be predicted for existing and new adsorbate-adsorbent systems with the MEA. The results show that MEA has the potential of becoming a standard characterization method for microporous solids that will lead to an increased understanding of their behavior in gas

  13. 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.)

  14. 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.

  15. Impact of urbanization on hydrochemical evolution of groundwater and on unsaturated-zone gas composition in the coastal city of Tel Aviv, Israel

    Science.gov (United States)

    Zilberbrand, M.; Rosenthal, E.; Shachnai, E.

    2001-08-01

    The coastal city of Tel Aviv was founded at the beginning of the 20th century. The number of its inhabitants and its water consumption increased rapidly. This study analyses a 15-year record (1934-1948) of pre-industrial development of groundwater chemistry in the urban area. Archive data on concentrations of major ions, dissolved gases (CO 2 and O 2), organic matter, and pH were available for each half-year during the period of 1934-1948. The major factors causing changes in the chemistry of groundwater flowing in three sandy sub-aquifers have been seawater encroachment due to overpumping, and infiltration of effluents from pit-latrine collectors. Influence of these factors decreases with depth. Landward-penetrating seawater passed through clayey coastal sediments, interbedded among sands and calcareous sandstones, and spread into the Kurkar Group aquifer. This has led to exchange of sodium (dominant in seawater) with calcium adsorbed on clay particles, enriching groundwater with calcium. Intensity of cation exchange decreases inland and with depth. Infiltration of pit-latrine effluents has introduced large amounts of ammonium into the unsaturated zone. Its rapid oxidation in unsaturated sediments has caused massive nitrate production, accompanied by pore-water acidification. This process induces dissolution of vadose carbonate, resulting in enrichment of groundwater recharge in calcium. Anthropogenically induced dissolution of calcite in the unsaturated zone has been the major factor for the increase of Ca 2+ concentration in groundwater, accounting for about 80% of this increase. In the interface zone, an additional 20% of calcium has been supplied by cation exchange. Owing to pH increase caused by denitrification in the aquifer, Ca 2+-rich waters supersaturated with calcite could be formed, especially in the capillary fringe of the uppermost sub-aquifer, which could induce calcite precipitation and ultimately lead to the cementation of sandy aquifers. Urban

  16. 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).

  17. 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.

  18. 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...

  19. 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

  20. 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

  1. 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.

  2. 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...

  3. 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.

  4. Regenerative adsorbent heat pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1991-01-01

    A regenerative adsorbent heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system and at least a portion of the heat of adsorption. A series of at least four compressors containing an adsorbent is provided. A large amount of heat is transferred from compressor to compressor so that heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  5. 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)

  6. Transporting method for adsorbing tower and the adsorbing tower

    International Nuclear Information System (INIS)

    Shimokawa, Nobuhiro.

    1996-01-01

    A cylindrical plastic bag is disposed to the upper surface of an adsorbing tower so as to surround a suspending piece. One opening of the bag is sealed, and other opening is secured in a sealed state to a bag holding portion disposed to glove box at a gate for the adsorbing tower box. The adsorbing tower is transported into the glove box, and after the completion of the operation of the adsorbing tower, the adsorbing tower is taken out in a state that the bag is restricted and sealed at a portion below the adsorbing tower. The bag may be made of a vinyl plastic, the bag holding portion may be a short-cylindrical protrusion, and may have an O-ring groove at the outer surface. Even if the adsorbing tower is heavy, the adsorbing tower can be carried out easily in a state where it is sealed gas tightly. (N.H.)

  7. Relating shear strength of unsaturated soils with capillary water retention curve

    Directory of Open Access Journals (Sweden)

    Zhou Annan

    2016-01-01

    Full Text Available This paper proposes a new water retention model for unsaturated soils, which takes into account capillary condensation of adsorbed water. In the proposed water retention model, the degree of saturation of a soil is separated into that based on capillary water and that based on adsorbed water. Through the analysis of a partially saturated two-cylinder system, a new shear strength criterion for unsaturated soils is proposed, in which only the degree of saturation based on capillary water contributes to the variation of shear strength with suction. The proposed shear strength criterion is justified against thermodynamic principles. The proposed strength criterion is compared against existing criteria in the literature, which shows that it provides a much improved prediction of the experimental data, for a wide range of suction values.

  8. 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)

  9. 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)

  10. Synthesis of nanoparticle emulsion collector HNP and its application in microfine chalcopyrite flotation

    Science.gov (United States)

    He, G. C.; Ding, J.; Huang, C. H.; Kang, Q.

    2018-01-01

    Hydrophobic polystyrene nanoparticles bearing thiazole groups named HNP were used as collectors to improve recovery of microfine chalcopyrite in flotation. HNP adsorbs onto microfine particles selectively, which were modified hydrophobically to induce flotation effectively. Particle size and scanning electron microscope analysis for HNP show that HNP is a spherical nano particles with small size, uniform distribution and good dispersion. Infrared spectrum analysis for HNP proved that functional monomer 2-mercapto styrene acrylic thiazole was bonded chemically onto styrene. Flotation test results indicate that HNP is the right collector of chalcopyrite. Especially, the recovery of chalcopyrite is higher than 95% in neutral and acid media. FTIR results reveal that the flotation selectivity of collector HNP is due to strong chemical absorption onto chalcopyrite surface. Zeta potential analysis shows that the zeta potential of chalcopyrite decreased more quickly after interaction with HNP with the increase of pulp pH value, confirming that collector HNP is an anionic collector. Scanning electron microscope conform that HNP has good selective adsorption on chalcopyrite.

  11. 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.

  12. 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

  13. 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)

  14. The state of physically adsorbed substances in microporous adsorbents

    International Nuclear Information System (INIS)

    Fomkin, A.A.

    1987-01-01

    Xe, Kr, Ar, CF 3 Cl, CH 4 adsorption in NaX microporous zeolite of 0.98 Na 2 OxAl 2 O 3 x2.36SiO 2 x0.02H 2 O is studied. Some properties of adsorbates (density, coefficients of expansion, enthalpy, heat capacity) are determined and discussed. The adsorbate in the microporous adsorbent is shown to be a particular state of a substance. Liniarity of adsorption isosteres and sharp changes during isosteric heat capacity of the adsorbate points to the fact that in microporous adsorbents phase transformations of the second type are possible

  15. 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.

  16. Orientational epitaxy in adsorbed monolayers

    International Nuclear Information System (INIS)

    Novaco, A.D.; McTague, J.P.

    1977-01-01

    The ground state for adsorbed monolayers on crystalline substrates is shown to involve a definite relative orientation of the substrate and adsorbate crystal axes, even when the relative lattice parameters are incommensurate. The rotation angle which defines the structure of the monolayer-substrate system is determined by the competition between adsorbate-substrate and adsorbate-adsorbate energy terms, and is generally not a symmetry angle. Numerical predictions are presented for the rare gas-graphite systems, whose interaction potentials are rather well known. Recent LEED data for some of these systems appear to corroborate these predictions

  17. 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...

  18. 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 ...

  19. 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.

  20. 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

  1. 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)

  2. 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.

  3. 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

  4. 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.

  5. Unsaturated transport of inorganic cations in undisturbed soil columns

    International Nuclear Information System (INIS)

    Jardine, P.M.; Jacobs, G.K.

    1990-01-01

    The unsaturated transport of Sr, Co, and Ca were studied in undisturbed soil columns (14 x 40 cm) of saprolitic shale to evaluate the significance of time dependent mass transfer and multispecies competitive exchange during transport. Observed breakthrough curves (BTCs) for Sr and Co were delayed relative to nonreactive Br BTC indicating that the former tracers were adsorbed by the soil. Effluent concentrations of Sr and Co were modeled with the classical convective dispersive (CD) equation and nonequilibrium mass transfer considerations did not appear necessary. Cation exchange equilibria relationships obtained from both shake batch and miscible displacement methods adequately described the thermodynamic processes which were prevalent during transport. These results suggest that the preferential transport of a reactive tracer is negligible for the realistic unsaturated conditions used in the study, and that the massive saprolite within the soil is a chemically active constituent during transport of reactive solutes. The implications of these findings for modeling in-situ subsurface contaminant transport are discussed. 7 refs., 9 figs

  6. 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.

  7. High performance Mo adsorbent PZC

    Energy Technology Data Exchange (ETDEWEB)

    Anon,

    1998-10-01

    We have developed Mo adsorbents for natural Mo(n, {gamma}){sup 99}Mo-{sup 99m}Tc generator. Among them, we called the highest performance adsorbent PZC that could adsorb about 250 mg-Mo/g. In this report, we will show the structure, adsorption mechanism of Mo, and the other useful properties of PZC when you carry out the examination of Mo adsorption and elution of {sup 99m}Tc. (author)

  8. 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

  9. Positronium chemistry in porous adsorbents

    International Nuclear Information System (INIS)

    Foti, G.; Nagy, L.G.; Moravcsik, G.; Schay, G.

    1981-01-01

    Kinetic studies on the annihilation of orthopositronium in porous adsorbents have been performed using lifetime spectroscopy. The positron source applied was 22 Na with 0.2 MBq activity. The adsorbents investigated were silica gels of different particle size and pore structure. The appearance of the long-lived component in the lifetime spectra can be explained by the diffusion of the orthopositronium into the pores affected by the particle size and the pore size of the adsorbent, the coverage on it and the chemical nature of the adsorbate. The long-term aim of the work is to determine and to explain these effects. (author)

  10. 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)

  11. 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.

  12. Design and performance characteristics of solar adsorption refrigeration system using parabolic trough collector: Experimental and statistical optimization technique

    International Nuclear Information System (INIS)

    Abu-Hamdeh, Nidal H.; Alnefaie, Khaled A.; Almitani, Khalid H.

    2013-01-01

    Highlights: • The successes of using olive waste/methanol as an adsorbent/adsorbate pair. • The experimental gross cycle coefficient of performance obtained was COP a = 0.75. • Optimization showed expanding adsorbent mass to a certain range increases the COP. • The statistical optimization led to optimum tank volume between 0.2 and 0.3 m 3 . • Increasing the collector area to a certain range increased the COP. - Abstract: The current work demonstrates a developed model of a solar adsorption refrigeration system with specific requirements and specifications. The recent scheme can be employed as a refrigerator and cooler unit suitable for remote areas. The unit runs through a parabolic trough solar collector (PTC) and uses olive waste as adsorbent with methanol as adsorbate. Cooling production, COP (coefficient of performance, and COP a (cycle gross coefficient of performance) were used to assess the system performance. The system’s design optimum parameters in this study were arrived to through statistical and experimental methods. The lowest temperature attained in the refrigerated space was 4 °C and the equivalent ambient temperature was 27 °C. The temperature started to decrease steadily at 20:30 – when the actual cooling started – until it reached 4 °C at 01:30 in the next day when it rose again. The highest COP a obtained was 0.75

  13. 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

  14. Graphene oxide-facilitated transport of levofloxacin and ciprofloxacin in saturated and unsaturated porous media.

    Science.gov (United States)

    Sun, Kaixuan; Dong, Shunan; Sun, Yuanyuan; Gao, Bin; Du, Wenchao; Xu, Hongxia; Wu, Jichun

    2018-04-15

    In this work, effects of graphene oxide (GO) on the co-transport of the two typical Fluoroquinolones (FQs) - levofloxacin (LEV) and ciprofloxacin (CIP) in saturated and unsaturated quartz sand media were studied. The adsorption isotherms showed that GO had much larger sorption capacities to LEV and CIP than sand with the largest Langmuir adsorption capacity of 409 mg g -1 (CIP-GO); while the sorption affinity of the two FQs onto the two adsorbents might follow the order of CIP-sand > LEV-sand > LEV-GO > CIP-GO. GO promoted the mobility of the two FQs in both saturated and unsaturated porous media due to its strong mobility and sorption capacity. The GO-bound LEV/CIP was responsible for the LEV/CIP transport in the porous media, and transport of GO-bound FQs increased with the increasing of initial GO concentration. Under unsaturated conditions, moisture showed little effect on the transport of GO-bound CIP; however, the mobility of GO-bound LEV reduced with the decreasing of moisture content, suggesting the transport of adsorbed LEV from GO to air-water interface. GO sorption reduced the antibacterial ability of the two FQs, but they were still effective in inhibiting E. coli growth. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. 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

  16. Study of a new solar adsorption refrigerator powered by a parabolic trough collector

    International Nuclear Information System (INIS)

    El Fadar, A.; Mimet, A.; Azzabakh, A.; Perez-Garcia, M.; Castaing, J.

    2009-01-01

    This paper presents the study of solar adsorption cooling machine, where the reactor is heated by a parabolic trough collector (PTC) and is coupled with a heat pipe (HP). This reactor contains a porous medium constituted of activated carbon, reacting by adsorption with ammonia. We have developed a model, based on the equilibrium equations of the refrigerant, adsorption isotherms, heat and mass transfer within the adsorbent bed and energy balance in the hybrid system components. From real climatic data, the model computes the performances of the machine. In comparison with other systems powered by flat plate or evacuated tube collectors, the predicted results, have illustrated the ability of the proposed system to achieve a high performance due to high efficiency of PTC, and high flux density of heat pipe

  17. 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.

  18. Collector sealants and breathing. Final Report, 25 September 1978-31 December 1979

    Energy Technology Data Exchange (ETDEWEB)

    Mendelsohn, M A; Luck, R M; Yeoman, F A; Navish, Jr, F W

    1980-02-20

    The objectives of this program were: (1) to investigate the pertinent properties of a variety of possible sealants for solar collectors and identify the most promising candidates, and (2) to study the effect of breathing in flat-plate, thermal solar collector units. The study involved two types of sealants, Class PS which includes preformed seals or gaskets and Class SC which includes sealing compounds or caulks. It was the intent of the study to obtain data regarding initial properties of candidate elastomers from manufacturers and from the technical literature and to use those sources to provide data pertaining to endurance of these materials under environmental service conditions. Where necessary, these data were augmented by experimental measurements. Environmental stresses evaluated by these measurements included elevated temperatures, moisture, ultraviolet light, ozone and oxygen, and fungus. The second major area of the work involved a study of the effects of materials used and design on the durability of solar collectors. Factors such as design, fabrication, materials of construction, seals and sealing techniques and absorber plate coatings were observed on actual field units removed from service. Such phenomena as leakage, corrosion and formation of deposits on glazing and absorber plate were noted. An evaluation of the properties of several desiccants was made in order to providemeans to mitigate the deleterious effects of water on collector life. Adsorbents for organic degradation products of sealants were also investigated in order to protect the glazing and absorber plate from deposited coatings. Since adsorbents and desiccants in general tend to take up both water and organic decomposition products, relative affinities of a number of these agents for water and for organic compounds were determined . Results are presented in detail.

  19. Evaluating sensitivity of unsaturated soil properties

    International Nuclear Information System (INIS)

    Abdel-Rahman, R.O.; El-Kamash, A.M.; Nagy, M.E.; Khalill, M.Y.

    2005-01-01

    The assessment of near surface disposal performance relay on numerical models of groundwater flow and contaminant transport. These models use the unsaturated soil properties as input parameters, which are subject to uncertainty due to measurements errors and the spatial variability in the subsurface environment. To ascertain how much the output of the model will depend on the unsaturated soil properties the parametric sensitivity analysis is used. In this paper, a parametric sensitivity analysis of the Van Genuchten moisture retention characteristic (VGMRC) model will be presented and conducted to evaluate the relative importance of the unsaturated soil properties under different pressure head values that represent various dry and wet conditions. (author)

  20. The unsaturated bistable stochastic resonance system.

    Science.gov (United States)

    Zhao, Wenli; Wang, Juan; Wang, Linze

    2013-09-01

    We investigated the characteristics of the output saturation of the classical continuous bistable system (saturation bistable system) and its impact on stochastic resonance (SR). We further proposed a piecewise bistable SR system (unsaturated bistable system) and developed the expression of signal-to-noise ratio (SNR) using the adiabatic approximation theory. Compared with the saturation bistable system, the SNR is significantly improved in our unsaturated bistable SR system. The numerical simulation showed that the unsaturated bistable system performed better in extracting weak signals from strong background noise than the saturation bistable system.

  1. Unsaturated medium hydrocarbons pollution evaluation

    International Nuclear Information System (INIS)

    Di Luise, G.

    1991-01-01

    When the so called porous unsaturated medium, that's the vertical subsoil section between both the ground and water-table level, is interested by a hydrocarbons spill, the problem to evaluate the pollution becomes difficult: considering, essentially, the natural coexistence in it of two fluids, air and water, and the interactions between them. This paper reports that the problems tend to increase when a third fluid, the pollutant, immiscible with water, is introduced into the medium: a three-phases flow, which presents several analogies with the flow conditions present in an oil-reservoir, will be established. In such a situation, it would be very useful to handle the matter by the commonly used parameters in the oil reservoirs studies such as: residual saturation, relative permeability, phases mobility, to derive a first semiquantitative estimation of the pollution. The subsoil pollution form hydrocarbons agents is one of the worldwide more diffused causes of contamination: such events are generally referable to two main effects: accidental (oil pipeline breakdowns, e.g.), and continuous (underground tanks breaks, industrial plants leakages, e.g.)

  2. 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.

  3. 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.

  4. 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.

  5. Principles of Physical Modelling of Unsaturated Soils

    OpenAIRE

    CAICEDO, Bernardo; THOREL, Luc

    2014-01-01

    Centrifuge modelling has been widely used to simulate the performance of a variety of geotechnical works, most of them focusing on saturated clays or dry sands. On the other hand, the performance of some geotechnical works depends on the behaviour of shallow layers in the soil deposit where it is frequently unsaturated. Centrifuge modelling could be a powerful tool to study the performance of shallow geotechnical works. However all the experimental complexities related to unsaturated soils, w...

  6. 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.

  7. 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

  8. 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)

  9. Black Sprayable Molecular Adsorber Coating

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective of this technology project is to develop, optimize, and flight qualify a black version of the molecular adsorber coating and a conductive version...

  10. 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...

  11. 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)

  12. 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...

  13. 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.

  14. 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.

  15. Homogeneously catalysed hydrogenation of unsaturated fatty acids to unsaturated fatty alcohols

    NARCIS (Netherlands)

    Stouthamer, B.; Vlugter, J.C.

    1965-01-01

    The use of copper and cadmium oxides or soaps as catalysts for the hydrogenation of unsaturated fatty acids to unsaturated fatty alcohols has been investigated. It is shown that copper soaps homogeneously activate hydrogen. When copper and cadmium oxides are used as catalysts, they react with the

  16. 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.

  17. 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....

  18. 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).

  19. 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....

  20. 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.

  1. Krypton retention on solid adsorbents

    International Nuclear Information System (INIS)

    Monson, P.R. Jr.

    1980-01-01

    Radioactive krypton-85 is released to the atmosphere in the off-gas from nuclear reprocessing plants. Three main methods have been suggested for removal of krypton from off-gas streams: cryogenic distillation; fluorocarbon absorption; and adsorption on solid sorbents. Use of solid adsorbents is the least developed of these methods, but offers the potential advantages of enhanced safety and lower operating costs. An experimental laboratory program was developed that will be used to investigate systematically many solid adsorbents (such as zeolites, i.e., mordenites) for trapping krypton in air. The objective of this investigation is to find an adsorbent that is more economical than silver-exchanged mordenite. Various physical and chemical characteristics such as adsorption isotherms, decontamination factors, co-adsorption, regeneration, and the mechanism and kinetics of noble gas adsorption were used to characterize the adsorbents. In the experimental program, a gas chromatograph using a helium ionization detector was used to measure the krypton in air before and after the adsorbent bed. This method can determine directly decontamination factors greater than 100

  2. 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....

  3. 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...

  4. 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...

  5. 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...

  6. 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)

  7. Electrokinetic extraction of chromate from unsaturated soils

    International Nuclear Information System (INIS)

    Mattson, E.D.; Lindgren, E.R.

    1993-01-01

    Heavy-metal contamination of soil and groundwater is a widespread problem in industrial nations. Remediation by excavation of such sites may not be cost effective or politically acceptable. Electrokinetic remediation is one possible remediation technique for in situ removal of such contaminants from unsaturated soils. Previous papers discussing the work performed by researchers at Sandia National Laboratories (SNL) and Sat-Unsat, Inc. (SUI) (Lindgren et al., 1991, 1992, 1993) focused on the transport of contaminants and dyes by electrokinetics in unsaturated soils. These experiments were conducted with graphite electrodes with no extraction system. As the contaminants migrated through the soil, they increased in concentration at the electrode creating a diffusion flux in the opposite direction. This paper discusses a technique to remove the contaminants from unsaturated soils once they have reached an electrode

  8. Electrokinetic extraction of chromate from unsaturated soils

    Energy Technology Data Exchange (ETDEWEB)

    Mattson, E.D. [SAT-UNSAT, Inc., Albuquerque, NM (United States); Lindgren, E.R. [Sandia National Labs., Albuquerque, NM (United States)

    1993-11-01

    Heavy-metal contamination of soil and groundwater is a widespread problem in industrial nations. Remediation by excavation of such sites may not be cost effective or politically acceptable. Electrokinetic remediation is one possible remediation technique for in situ removal of such contaminants from unsaturated soils. Previous papers discussing the work performed by researchers at Sandia National Laboratories (SNL) and Sat-Unsat, Inc. (SUI) (Lindgren et al., 1991, 1992, 1993) focused on the transport of contaminants and dyes by electrokinetics in unsaturated soils. These experiments were conducted with graphite electrodes with no extraction system. As the contaminants migrated through the soil, they increased in concentration at the electrode creating a diffusion flux in the opposite direction. This paper discusses a technique to remove the contaminants from unsaturated soils once they have reached an electrode.

  9. 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

  10. Krypton retention on solid adsorbents

    International Nuclear Information System (INIS)

    Monson, P.R. Jr.

    1982-01-01

    An experimental laboratory program was conducted to develop economical solid adsorbents for the retention of krypton from a dissolver off-gas stream. The study indicates that a solid adsorbent system is feasible and competitive with other developing systems which utilize fluorocarbon absorption nd cryogenic distillation. This technology may have potential applications not only in nuclear fuel reprocessing plants, but also in nuclear reactors and in environmental monitoring. Of the 13 prospective adsorbents evaluated with respect to adsorption capacity and cost, the commercially available hydrogen mordenite was the most cost-effective material at subambient temperatures (-40 0 to -80 0 C). Silver mordenite has a higher capacity for krypton retention, but is 50 times more expensive than hydrogen mordenite

  11. Membrane adsorber for endotoxin removal

    Directory of Open Access Journals (Sweden)

    Karina Moita de Almeida

    Full Text Available ABSTRACT The surface of flat-sheet nylon membranes was modified using bisoxirane as the spacer and polyvinyl alcohol as the coating polymer. The amino acid histidine was explored as a ligand for endotoxins, aiming at its application for endotoxin removal from aqueous solutions. Characterization of the membrane adsorber, analysis of the depyrogenation procedures and the evaluation of endotoxin removal efficiency in static mode are discussed. Ligand density of the membranes was around 7 mg/g dry membrane, allowing removal of up to 65% of the endotoxins. The performance of the membrane adsorber prepared using nylon coated with polyvinyl alcohol and containing histidine as the ligand proved superior to other membrane adsorbers reported in the literature. The lack of endotoxin adsorption on nylon membranes without histidine confirmed that endotoxin removal was due to the presence of the ligand at the membrane surface. Modified membranes were highly stable, exhibiting a lifespan of approximately thirty months.

  12. Browns Ferry charcoal adsorber incident

    International Nuclear Information System (INIS)

    Mays, G.T.

    1979-01-01

    The article reviews the temperature excursion in the charcoal adsorber beds of the Browns Ferry Unit 3 off-gas system that occurred on July 17, 1977. Significant temperature increases were experienced in the charcoal adsorber beds when charcoal fines were ignited by the ignition of a combustible mixture of hydrogen and oxygen in the off-gas system. The Browns Ferry off-gas system is described, and events leading up to and surrounding the incident are discussed. The follow-up investigation by Tennessee Valley Authority and General Electric Company personnel and their recommendations for system and operational modifications are summarized

  13. Krypton retention on solid adsorbents

    International Nuclear Information System (INIS)

    Monson, P.R. Jr.

    1981-08-01

    Over a dozen prospective adsorbents for krypton were studied and evaluated with respect to adsorption capacity and cost for dissolver off-gas streams from nuclear reprocessing plants. Results show that, at subambient temperature (-40 0 to -80 0 C), the commercially available hydrogen mordenite has sufficient adsorptive capacity to be the most cost-effective material studied. Silver mordenite has a higher capacity for krypton retention, but is 50 times more expensive than hydrogen mordenite. The results indicate that a solid adsorbent system is feasible and competitive with other developing systems whih utilize fluorocarbon absorption and cryogenic distillation

  14. The Adsorption of n-Octanohydroxamate Collector on Cu and Fe Oxide Minerals Investigated by Static Secondary Ion Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Alan N. Buckley

    2012-12-01

    Full Text Available The feasibility of investigating the adsorption of n-octanohydroxamate collector on copper and iron oxide minerals with static secondary ion mass spectrometry has been assessed. Secondary ion mass spectra were determined for abraded surfaces of air-exposed copper metal, malachite, pseudomalachite and magnetite that had been conditioned in aqueous potassium hydrogen n-octanohydroxamate solution, as well as for the corresponding bulk CuII and FeIII complexes. In each case, the chemical species present at the solid/vacuum interface of a similarly prepared surface were established by X-ray photoelectron spectroscopy. The most abundant positive and negative metal-containing fragment ions identified for the bulk complexes were also found to be diagnostic secondary ions for the collector adsorbed on the oxide surfaces. The relative abundances of those diagnostic ions varied with, and could be rationalised by, the monolayer or multilayer coverage of the adsorbed collector. However, the precise mass values for the diagnostic ions were not able to corroborate the different bonding in the copper and iron hydroxamate systems that had been deduced from photoelectron and vibrational spectra. Parent secondary ions were able to provide supporting information on the co-adsorption of hydroxamic acid at each conditioned surface.

  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. Vertical hydrochemical profiles in the unsaturated zone of louga ...

    African Journals Online (AJOL)

    Solutions chemistry of the rainwater and the unsaturated zone interstitial water of Louga (Northern Senegal) local aquifer provide valuable ... together with chemical analysis of the interstitial water carried out through the entire unsaturated ...

  1. Waste package performance in unsaturated rock

    International Nuclear Information System (INIS)

    Pigford, T.H.; Lee, W.W.-L.

    1989-03-01

    The unsaturated rock and near-atmospheric pressure of the potential nuclear waste repository at Yucca Mountain present new problems of predicting waste package performance. In this paper we present some illustrations of predictions of waste package performance and discuss important data needs. 11 refs., 9 figs., 1 tab

  2. Oxygenation of saturated and unsaturated hydrocarbons with ...

    Indian Academy of Sciences (India)

    Unknown

    Oxygenation of saturated and unsaturated hydrocarbons with sodium periodate. 431. Table 1. Competitive oxygenation of tetralin and cyclooctene with sodium periodate catalyzed by different manga- .... Teacher Education University. My grateful thanks also extend to Dr D Mohajer for his useful sugges- tions. References. 1.

  3. Movement of radionuclides through unsaturated soils

    International Nuclear Information System (INIS)

    de Sousa, F.N.C.

    1985-01-01

    The advantages of the disposal of low-level radioactive wastes in the unsaturated zone above the fluctuations of the water table have been recognized for some time. However, most the numerical models used to simulate the environmental impact of a shallow land burial site assume that the soils surrounding the waste forms are saturated; this assumption may lead, in many cases, to unrealistic large leach and water flow rates. The main purpose of this study was the development of a procedure which could give a reliable prediction on the movement of radionuclides from shallow land burial sites located in the unsaturated zone. In order to accomplish this objective three different soils having different sand, silt, and clay fractions were selected and characterized. These soils were then used to fill a number of flow columns that were used in tests designed to provide input data for the flow and transport models. A one-dimensional finite element model was developed in order to simulate the water flow and radionuclide transport through unsaturated soils. The results obtained showed that the model accurately described the transport of radionuclides through saturated-unsaturated soils. Simulations were done, for all three soils, involving different degrees of soil saturation, and the results showed that assuming the soils are always saturated may lead to nuclide transport times which are orders of magnitude larger than the real ones, depending on the clay percentage present in the soil

  4. Adsorption of N-tallow 1,3-propanediamine-dioleate collector on albite and quartz minerals, and selective flotation of albite from greek stefania feldspar ore.

    Science.gov (United States)

    Vidyadhar, A; Hanumantha Rao, K; Forssberg, K S E

    2002-04-01

    The adsorption behavior of tallow 1,3-propanediamine-dioleate (Duomeen TDO) collector on albite and quartz minerals is assessed through Hallimond flotation, zeta potential, and diffuse reflectance FTIR investigations, together with the species distribution of the collector. The collector performance on albite separation from a natural feldspar material is evaluated in bench scale flotation tests. The Hallimond flotation responses of the minerals as a function of pH and collector concentration indicate that albite can be selectively floated from quartz at pH 2 where the doubly positively charged collector species adsorb on albite but not on quartz. However, the zeta potential and infrared spectra reveal that the adsorption behavior of the collector is similar on both minerals. The discrepancy in the flotation and adsorption results is attributed to the coarse and fine particle size fractions, and the shorter and longer equilibration periods employed in these studies respectively. The comparable adsorption on fine particles of albite and quartz at pH 2 is explained by the interaction of ammonium ions on silanol groups by hydrogen bonding as well as electrostatic interactions. The changes in zeta potentials are in good agreement with the formation of ionic species and free molecular forms of the collector. The IR spectra show the coexistence of neutral oleic acid together with charged amine species at low pH values in accordance with the species distribution diagram. Selective flotation of albite is accomplished from a natural feldspar material with tallow diamine-dioleate collector at pH 2 using sulfuric acid, only when the feed is deslimed prior to the bench scale flotation tests. An albite recovery exceeding 85% is achieved from a feed material containing about 50% albite.

  5. 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.

  6. 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...

  7. 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.

  8. 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

  9. 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.

  10. 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...

  11. 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.

  12. Iodine removal adsorbent histories, aging and regeneration

    International Nuclear Information System (INIS)

    Hunt, J.R.; Rankovic, L.; Lubbers, R.; Kovach, J.L.

    1976-01-01

    The experience of efficiency changes with life under various test conditions is described. The adsorbents were periodically removed from both standby and continuously operating systems and tested under various test methods for residual iodine adsorption efficiency. Adsorbent from several conventional ''sampler'' cartridges versus the bulk adsorbent was also tested showing deficiency in the use of cartridge type sampling. Currently required test conditions were found inadequate to follow the aging of the adsorbent because pre-equilibration of the sample acts as a regenerant and the sample is not tested in the ''as is'' condition. The most stringent test was found to be the ambient temperature, high humidity test to follow the aging of the adsorbent. Several methods were evaluated to regenerate used adsorbents; of these high temperature steaming and partial reimpregnation were found to produce adsorbents with near identical properties of freshly prepared adsorbents

  13. Pumping Test Determination of Unsaturated Aquifer Properties

    Science.gov (United States)

    Mishra, P. K.; Neuman, S. P.

    2008-12-01

    Tartakovsky and Neuman [2007] presented a new analytical solution for flow to a partially penetrating well pumping at a constant rate from a compressible unconfined aquifer considering the unsaturated zone. In their solution three-dimensional, axially symmetric unsaturated flow is described by a linearized version of Richards' equation in which both hydraulic conductivity and water content vary exponentially with incremental capillary pressure head relative to its air entry value, the latter defining the interface between the saturated and unsaturated zones. Both exponential functions are characterized by a common exponent k having the dimension of inverse length, or equivalently a dimensionless exponent kd=kb where b is initial saturated thickness. The authors used their solution to analyze drawdown data from a pumping test conducted by Moench et al. [2001] in a Glacial Outwash Deposit at Cape Cod, Massachusetts. Their analysis yielded estimates of horizontal and vertical saturated hydraulic conductivities, specific storage, specific yield and k . Recognizing that hydraulic conductivity and water content seldom vary identically with incremental capillary pressure head, as assumed by Tartakovsky and Neuman [2007], we note that k is at best an effective rather than a directly measurable soil parameter. We therefore ask to what extent does interpretation of a pumping test based on the Tartakovsky-Neuman solution allow estimating aquifer unsaturated parameters as described by more common constitutive water retention and relative hydraulic conductivity models such as those of Brooks and Corey [1964] or van Genuchten [1980] and Mualem [1976a]? We address this question by showing how may be used to estimate the capillary air entry pressure head k and the parameters of such constitutive models directly, without a need for inverse unsaturated numerical simulations of the kind described by Moench [2003]. To assess the validity of such direct estimates we use maximum

  14. 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...

  15. 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.

  16. Supercritical fluid regeneration of adsorbents

    Science.gov (United States)

    Defilippi, R. P.; Robey, R. J.

    1983-05-01

    The results of a program to perform studies supercritical (fluid) carbon dioxide (SCF CO2) regeneration of adsorbents, using samples of industrial wastewaters from manufacturing pesticides and synthetic solution, and to estimate the economics of the specific wastewater treatment regenerations, based on test data are given. Processing costs for regenerating granular activated carbon GAC) for treating industrial wastewaters depend on stream properties and regeneration throughput.

  17. 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...

  18. A study of the effects of collector and environment parameters on the performance of a solar powered solid adsorption refrigerator

    International Nuclear Information System (INIS)

    Li, M.; Wang, R.Z.

    2002-01-01

    Based on the heat and mass transfer model validated by experiment, the performance of the plate solar ice-maker is analyzed systemically with the opinion of two-type characteristic parameters, which includes parametric effects of adsorbent bed of solar ice-maker and outer parameters referring to circumstance. A large number of simulations were undertaken to test the performance of the refrigerator for various collector design parameters and environmental parameters. These works are beneficial to further study the optimization design of a solar cooling system. (Author)

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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.

  6. Effect of Pb2+ ions on ilmenite flotation and adsorption of benzohydroxamic acid as a collector

    Science.gov (United States)

    Xu, Longhua; Tian, Jia; Wu, Houqin; Lu, Zhongyuan; Yang, Yaohui; Sun, Wei; Hu, Yuehua

    2017-12-01

    The effects of Pb2+ ions on ilmenite flotation and adsorption of benzohydroxamic acid (BHA) as a collector were investigated using microflotation tests, zeta potential measurements, adsorption analysis, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The microflotation results indicate that the addition of Pb2+ significantly improves the recovery of ilmenite using BHA as a collector. A maximum recovery of 88.46% is obtained at pH 8.12 in the presence of Pb2+; a maximum recovery of 45% is obtained at the same pH using BHA alone. At pHs below 8.0, lead nitrate are mainly present in the solution as Pb2+ and PbOH+, while at pHs above 8.0, the predominant components are Pb(OH)2(s) and Pb(OH)3-. The adsorption of these lead species influences the zeta potential of ilmenite and the number of activated sites on the ilmenite surface. FTIR and XPS analyses reveal that lead species and BHA react with the metal sites on the ilmenite surface. The lead species in solution are either adsorbed onto the ilmenite surface, which increases the surface activity of ilmenite, or react with BHA in solution to form complexes of lead and BHA.

  7. Analysis of Rainfall Infiltration Law in Unsaturated Soil Slope

    OpenAIRE

    Zhang, Gui-rong; Qian, Ya-jun; Wang, Zhang-chun; Zhao, Bo

    2014-01-01

    In the study of unsaturated soil slope stability under rainfall infiltration, it is worth continuing to explore how much rainfall infiltrates into the slope in a rain process, and the amount of rainfall infiltrating into slope is the important factor influencing the stability. Therefore, rainfall infiltration capacity is an important issue of unsaturated seepage analysis for slope. On the basis of previous studies, rainfall infiltration law of unsaturated soil slope is analyzed. Considering t...

  8. Unsaturated fatty acids in the diet of inpatients

    OpenAIRE

    KONHEFROVÁ, Veronika

    2015-01-01

    The thesis with the name "Unsaturated fatty acids in the diet of inpatients" is divided into a theoretical and a research parts. The theoretical part is focused on sorting out lipids and the recommended daily dosing. Next there are described the chemical structure of fatty acids and basic differences between saturated (SFA) and unsaturated (trans and cis) fatty acids. The biggest part of the theory is formed by the unsaturated fatty acids, their characteristics, food source and their effect o...

  9. Review and selection of unsaturated flow models

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, M.; Baker, N.A.; Duguid, J.O. [INTERA, Inc., Las Vegas, NV (United States)

    1994-04-04

    Since the 1960`s, ground-water flow models have been used for analysis of water resources problems. In the 1970`s, emphasis began to shift to analysis of waste management problems. This shift in emphasis was largely brought about by site selection activities for geologic repositories for disposal of high-level radioactive wastes. Model development during the 1970`s and well into the 1980`s focused primarily on saturated ground-water flow because geologic repositories in salt, basalt, granite, shale, and tuff were envisioned to be below the water table. Selection of the unsaturated zone at Yucca Mountain, Nevada, for potential disposal of waste began to shift model development toward unsaturated flow models. Under the US Department of Energy (DOE), the Civilian Radioactive Waste Management System Management and Operating Contractor (CRWMS M&O) has the responsibility to review, evaluate, and document existing computer models; to conduct performance assessments; and to develop performance assessment models, where necessary. This document describes the CRWMS M&O approach to model review and evaluation (Chapter 2), and the requirements for unsaturated flow models which are the bases for selection from among the current models (Chapter 3). Chapter 4 identifies existing models, and their characteristics. Through a detailed examination of characteristics, Chapter 5 presents the selection of models for testing. Chapter 6 discusses the testing and verification of selected models. Chapters 7 and 8 give conclusions and make recommendations, respectively. Chapter 9 records the major references for each of the models reviewed. Appendix A, a collection of technical reviews for each model, contains a more complete list of references. Finally, Appendix B characterizes the problems used for model testing.

  10. Hydrocarbons biodegradation in unsaturated porous medium

    International Nuclear Information System (INIS)

    Gautier, C.

    2007-12-01

    Biological processes are expected to play an important role in the degradation of petroleum hydrocarbons in contaminated soils. However, factors influencing the kinetics of biodegradation are still not well known, especially in the unsaturated zone. To address these biodegradation questions in the unsaturated zone an innovative experimental set up based on a physical column model was developed. This experimental set up appeared to be an excellent tool for elaboration of a structured porous medium, with well defined porous network and adjusted water/oil saturations. Homogeneous repartition of both liquid phases (i.e., aqueous and non aqueous) in the soil pores, which also contain air, was achieved using ceramic membranes placed at the bottom of the soil column. Reproducible interfaces (and connectivity) are developed between gas, and both non mobile water and NAPL phases, depending on the above-defined characteristics of the porous media and on the partial saturations of these three phases (NAPL, water and gas). A respirometric apparatus was coupled to the column. Such experimental set up have been validated with hexadecane in dilution in an HMN phase. This approach allowed detailed information concerning n-hexadecane biodegradation, in aerobic condition, through the profile of the oxygen consumption rate. We have taken benefit of this technique, varying experimental conditions, to determine the main parameters influencing the biodegradation kinetics and compositional evolution of hydrocarbons, under steady state unsaturated conditions and with respect to aerobic metabolism. Impacts of the nitrogen quantity and of three different grain sizes have been examined. Biodegradation of petroleum cut, as diesel cut and middle distillate without aromatic fraction, were, also studied. (author)

  11. Review and selection of unsaturated flow models

    International Nuclear Information System (INIS)

    Reeves, M.; Baker, N.A.; Duguid, J.O.

    1994-01-01

    Since the 1960's, ground-water flow models have been used for analysis of water resources problems. In the 1970's, emphasis began to shift to analysis of waste management problems. This shift in emphasis was largely brought about by site selection activities for geologic repositories for disposal of high-level radioactive wastes. Model development during the 1970's and well into the 1980's focused primarily on saturated ground-water flow because geologic repositories in salt, basalt, granite, shale, and tuff were envisioned to be below the water table. Selection of the unsaturated zone at Yucca Mountain, Nevada, for potential disposal of waste began to shift model development toward unsaturated flow models. Under the US Department of Energy (DOE), the Civilian Radioactive Waste Management System Management and Operating Contractor (CRWMS M ampersand O) has the responsibility to review, evaluate, and document existing computer models; to conduct performance assessments; and to develop performance assessment models, where necessary. This document describes the CRWMS M ampersand O approach to model review and evaluation (Chapter 2), and the requirements for unsaturated flow models which are the bases for selection from among the current models (Chapter 3). Chapter 4 identifies existing models, and their characteristics. Through a detailed examination of characteristics, Chapter 5 presents the selection of models for testing. Chapter 6 discusses the testing and verification of selected models. Chapters 7 and 8 give conclusions and make recommendations, respectively. Chapter 9 records the major references for each of the models reviewed. Appendix A, a collection of technical reviews for each model, contains a more complete list of references. Finally, Appendix B characterizes the problems used for model testing

  12. Barriers to bacterial motility on unsaturated surfaces

    DEFF Research Database (Denmark)

    Dechesne, Arnaud; Smets, Barth F.

    2013-01-01

    Our knowledge of the spatial organization and spatial dynamics of microbial populations in soil at a scale close to that of the microorganisms is scarce. While passive dispersal via water ow or soil biota is probably a major dispersal route, it is reasonable to consider that active dispersal also...... and their isogenic mutants unable to express various type of motility we aimed to quantify the physical limits of bacterial motility. Our results demonstrate how hydration controls bacterial motility under unsaturated conditions. They can form the base of improved biodegradation models that include microbial...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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...

  20. 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.

  1. 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

  2. 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...

  3. A novel fiber-based adsorbent technology

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, T.A. [Chemica Technologies, Inc., Bend, OR (United States)

    1997-10-01

    In this Phase I Small Business Innovation Research program, Chemica Technologies, Inc. is developing an economical, robust, fiber-based adsorbent technology for removal of heavy metals from contaminated water. The key innovation is the development of regenerable adsorbent fibers and adsorbent fiber cloths that have high capacity and selectivity for heavy metals and are chemically robust. The process has the potential for widespread use at DOE facilities, mining operations, and the chemical process industry.

  4. Removal of Cobalt Ion by Adsorbing Colloidal Flotation

    Energy Technology Data Exchange (ETDEWEB)

    Jung, In Ha; Lee, Jung Won [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-09-30

    Simulated waste liquid containing 50 ppm cobalt ion was treated by adsorbing colloidal flotation using Fe(III) or Al(III) as flocculant and a sodium lauryl sulfate as a collector. Parameters such as pH, surfactant concentration, Fe(III) or Al(III) concentration, gas flow rate, etc., were considered. The flotation with Fe(III) showed 99.8% removal efficiency of cobalt on the conditions of initial cobalt ion concentration 50 ppm, pH 9.5, gas flow rate 70 ml/min, and flotation time 30 min. When the waste solution was treated with 35% H{sub 2}O{sub 2} prior to adsorbing colloidal flotation, the optimal pH for removing cobalt shifted to weak alkaline range and flotation could be applied in wider range of pH as compared to non-use of H{sub 2}O{sub 2}. Additional use of 20 ppm Al(III) after precipitation of 50 ppm Co(II) with 50 ppm Fe(III) made the optimal pH range for preferable flotation wider. Foreign ions such as, NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, Na{sup +}, Ca{sup 2+} were adopted and their effects were observed, Of which sulfate ion was found to be detrimental to removal of cobalt ion by flotation. Coprecipitation of Co ion with Fe(III) and Al(III) resulted in better removal efficiency of cobalt ion in the presence of sulfate ion. (author). 14 refs., 13 figs.

  5. 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.

  6. 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...

  7. 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.

  8. 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.

  9. 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)

  10. 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...

  11. 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.

  12. 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

  13. A comparison study of adsorption of benzohydroxamic acid and amyl xanthate on smithsonite with dodecylamine as co-collector

    Science.gov (United States)

    Wang, Zhen; Xu, Longhua; Wang, Jinming; Wang, Li; Xiao, Junhui

    2017-12-01

    The objective of this paper is to display the results of the flotation and adsorption behaviors of benzohydroxamic acid (BHA), potassium amyl xanthate (KAX), dodecylamine- hydrochloride (DDA), mixed BHA/DDA and KAX/DDA on smithsonite. The flotation results show a collecting ability sequence of BHA > KAX > DDA on smithsonite and the best flotation performance at mixing ratio of 1:4 mol fraction DDA/KAX for mixed collector on smithsonite. The enhancement of smithsonite recovery by co-adsorption of KAX and DDA, while no promotion effect as to mixed BHA/DDA catanionic system, are attributed to the difference in steric effect of absorbed head group. According to the results of zeta potential and contact angle (CA) measurements, a most negative charged and the highest hydrophobic smithsonite surface are attained using KAX with DDA as co-collector, which shows a good agreement with the flotation results. FTIR measurements display the stabilization against oxidation and decomposition of DDA on KAX and the inhibition of preferential adsorbed BHA ions on DDA adsorption. The interaction energies of single and mixed collectors with mineral surface also shows well consistency with experimental results. The adsorption models proposed illustrate the decrease in the electrostatic head-head repulsion and the increase in lateral tail-tail hydrophobic interaction between adjacent KAX anions due to the insertion of DDA cations, while almost no DDA could access to smithsonite surface through adjacent BHA owing to steric effect.

  14. Neutron scattering from adsorbed species

    International Nuclear Information System (INIS)

    Shuwang An

    1998-01-01

    Neutron reflection has been used to investigate the structure of layers of water-soluble diblock copolymers poly(2-(dimethylamino)ethyl methacrylate-block-methyl methacrylate (poly(DMAEMA-b-MMA)) (70 mol% DMAEMA, M n = 10k, 80 mol% DMAEMA, M n = 10k, and 70 mol% DMAEMA, M n = 20k) adsorbed at the air-liquid and solid-liquid interfaces. The surface tension behaviour of these copolymers at the air-liquid interface has also been investigated. The study of the structure of layers of poly(DMAEMA-b-MMA) adsorbed at the air-water interface forms the main part of the thesis. The surface structure, the effects of pH and ionic strength, and the effects of composition and molecular weight of the copolymers have been studied systematically. For the 70%-10k copolymer at pH 7.5, the adsorption isotherm shows that there is a surface phase transition. The concentration of copolymer at which the phase transition occurs is close to that at which micellar aggregation in the bulk solution also occurs. At low concentrations (below the CMC), the two blocks of the copolymer are approximately uniformly distributed in the direction normal to the interface and the layer is partially immersed in water. At high concentrations (above the CMC), the adsorbed layer has a cross-sectional structure resembling that expected for a micelle with the majority of the MMA blocks forming the core. The outer layers, comprising predominantly DMAEMA blocks, are not equivalent, being more highly extended on the aqueous side of the interface. The effects of pH and added electrolyte on the structure of layers of the 70%-10k copolymer show that the layered structure is promoted by any changes in the bulk solution that enhance the surface coverage but is inhibited by an increase in the fractional charge on the polyelectrolyte part of the copolymer. The effect of lowering the pH is to increase the positive charge on the weak polyelectrolyte block. Addition of electrolyte generally enhances the amount adsorbed and

  15. Estimate of dispersion in an unsaturated aquifer

    Science.gov (United States)

    Stephenson, D.; De Jesus, A. S. M.

    1985-10-01

    The Nuclear Development Corporation of South Africa (Pty) Ltd. (NUCOR) is constructing a low-level radioactive waste disposal site near Springbok in Namaqualand, an arid region to the west of South Africa. A groundwater model was developed which required site-specific data and this work describes procedures developed to assess the dispersivity of the soil in the vicinity of the proposed site. Preliminary laboratory tests, carried out using a sodium chloride solution, indicated the order of magnitude of the dispersivity for saturated soil at various levels. This enabled site tests to be designed. The site tests were done by injecting a pulse of scandium-46 into a hole and monitoring the displacement of the radioactive cloud as it moved down under gravity and spread laterally. A mathematical model was developed to predict the behaviour of the cloud and calibration of the model yielded vertical and horizontal dispersivities. The dispersion of radioactivity at the cloud front was assumed to occur in unsaturated medium while the continuously injected water behind the radioactivity was assumed to disperse in a saturated medium. Thus monitoring the concentration of both yielded approximate values for the effective dispersivities in unsaturated and saturated media.

  16. NaturAnalogs for the Unsaturated Zone

    Energy Technology Data Exchange (ETDEWEB)

    A. Simmons; A. Unger; M. Murrell

    2000-03-08

    The purpose of this Analysis/Model Report (AMR) is to document natural and anthropogenic (human-induced) analog sites and processes that are applicable to flow and transport processes expected to occur at the potential Yucca Mountain repository in order to build increased confidence in modeling processes of Unsaturated Zone (UZ) flow and transport. This AMR was prepared in accordance with ''AMR Development Plan for U0135, Natural Analogs for the UZ'' (CRWMS 1999a). Knowledge from analog sites and processes is used as corroborating information to test and build confidence in flow and transport models of Yucca Mountain, Nevada. This AMR supports the Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR) and the Yucca Mountain Site Description. The objectives of this AMR are to test and build confidence in the representation of UZ processes in numerical models utilized in the UZ Flow and Transport Model. This is accomplished by: (1) applying data from Boxy Canyon, Idaho in simulations of UZ flow using the same methodologies incorporated in the Yucca Mountain UZ Flow and Transport Model to assess the fracture-matrix interaction conceptual model; (2) Providing a preliminary basis for analysis of radionuclide transport at Pena Blanca, Mexico as an analog of radionuclide transport at Yucca Mountain; and (3) Synthesizing existing information from natural analog studies to provide corroborating evidence for representation of ambient and thermally coupled UZ flow and transport processes in the UZ Model.

  17. Natural Analogs for the Unsaturated Zone

    International Nuclear Information System (INIS)

    Simmons, A.; Unger, A.; Murrell, M.

    2000-01-01

    The purpose of this Analysis/Model Report (AMR) is to document natural and anthropogenic (human-induced) analog sites and processes that are applicable to flow and transport processes expected to occur at the potential Yucca Mountain repository in order to build increased confidence in modeling processes of Unsaturated Zone (UZ) flow and transport. This AMR was prepared in accordance with ''AMR Development Plan for U0135, Natural Analogs for the UZ'' (CRWMS 1999a). Knowledge from analog sites and processes is used as corroborating information to test and build confidence in flow and transport models of Yucca Mountain, Nevada. This AMR supports the Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR) and the Yucca Mountain Site Description. The objectives of this AMR are to test and build confidence in the representation of UZ processes in numerical models utilized in the UZ Flow and Transport Model. This is accomplished by: (1) applying data from Boxy Canyon, Idaho in simulations of UZ flow using the same methodologies incorporated in the Yucca Mountain UZ Flow and Transport Model to assess the fracture-matrix interaction conceptual model; (2) Providing a preliminary basis for analysis of radionuclide transport at Pena Blanca, Mexico as an analog of radionuclide transport at Yucca Mountain; and (3) Synthesizing existing information from natural analog studies to provide corroborating evidence for representation of ambient and thermally coupled UZ flow and transport processes in the UZ Model

  18. Unsaturated zone flow modeling for GWTT-95

    International Nuclear Information System (INIS)

    Ho, C.K.; Altman, S.J.; McKenna, S.A.; Arnold, B.W.

    1995-01-01

    In accordance with the Nuclear Regulatory Commission regulation regarding groundwater travel times at geologic repositories, various models of unsaturated flow in fractured tuff have been developed and implemented to assess groundwater travel times at the potential repository at Yucca Mountain, Nevada. Kaplan used one-dimensional models to describe the uncertainty and sensitivity of travel times to various processes at Yucca Mountain. Robey and Arnold et al. used a two-dimensional equivalent continuum model (ECM) with inter- and intra-unit heterogeneity in an attempt to assess fast-flow paths through the unsaturated, fractured tuff at Yucca Mountain (GWTT-94). However, significant flow through the fractures in previous models was not simulated due to the characteristics of the ECM, which requires the matrix to be nearly saturated before flow through the fractures is initiated. In the current study (GWTT-95), four two-dimensional cross-sections at Yucca Mountain are simulated using both the ECM and dual-permeability (DK) models. The properties of both the fracture and matrix domains are geostatistically simulated, yielding completely heterogeneous continua. Then, simulations of flow through the four cross-sections are performed using spatially nonuniform infiltration boundary conditions. Steady-state groundwater travel times from the potential repository to the water table are calculated

  19. Filter-adsorber aging assessment

    Energy Technology Data Exchange (ETDEWEB)

    Winegardner, W.K. [Pacific Northwest Laboratory, Richland, WA (United States)

    1995-02-01

    An aging assessment of high-efficiency particulate (HEPA) air filters and activated carbon gas adsorption units was performed by the Pacific Northwest Laboratory as part of the U.S. Nuclear Regulatory Commission`s (USNRC) Nuclear Plant Aging Research (NPAR) Program. This evaluation of the general process in which characteristics of these two components gradually change with time or use included the compilation of information concerning failure experience, stressors, aging mechanisms and effects, and inspection, surveillance, and monitoring methods (ISMM). Stressors, the agents or stimuli that can produce aging degradation, include heat, radiation, volatile contaminants, and even normal concentrations of aerosol particles and gasses. In an experimental evaluation of degradation in terms of the tensile breaking strength of aged filter media specimens, over forty percent of the samples did not meet specifications for new material. Chemical and physical reactions can gradually embrittle sealants and gaskets as well as filter media. Mechanisms that can lead to impaired adsorber performance are associated with the loss of potentially available active sites as a result of the exposure of the carbon to airborne moisture or volatile organic compounds. Inspection, surveillance, and monitoring methods have been established to observe filter pressure drop buildup, check HEPA filters and adsorbers for bypass, and determine the retention effectiveness of aged carbon. These evaluations of installed filters do not reveal degradation in terms of reduced media strength but that under normal conditions aged media can continue to effectively retain particles. However, this degradation may be important when considering the likelihood of moisture, steam, and higher particle loadings during severe accidents and the fact it is probable that the filters have been in use for an extended period.

  20. 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.

  1. 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.

  2. 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.

  3. Ecological applications of the irradiated adsorbents

    International Nuclear Information System (INIS)

    Tusseyev, T.

    2004-01-01

    Full text: In our previous works it was shown that after irradiation some adsorbents gain new interesting properties such as increasing (or decreasing) of their adsorption capacity, selectivity in relation to some gases, change of chemical bounds of gas molecules with adsorbent surface as well as other properties. We investigated a lot of adsorbents with semiconducting and dielectric properties. A high temperature superconductor was investigated also. Adsorbents were irradiated by ultraviolet (UV) and gamma - radiation, reactor (n.γ) - radiation, α-particles (E=40-50 MeV), protons ( E=30 MeV), and also He-3 ions (E-29-60 MeV). The following techniques were used: volumetric (manometrical), mass-spectrometer and IR spectroscopic methods, and also method of electronic - paramagnetic resonance (spin paramagnetic resonance) The obtained results allow to speak about creation of new adsorbents for gas purification (clearing) from harmful impurities, gas selection into components, an increasing of adsorbing surface. Thus one more advantage of the irradiated adsorbents is that they have 'memory effect', i.e. they can be used enough long time after irradiation. In laboratory conditions we built the small-sized adsorptive pump on the basis of the irradiated zeolites which are capable to work in autonomous conditions. It was found, that some of adsorbents after irradiation gain (or lose) selectivity in relation to definite gases. So, silica gel, which one in initial state does not adsorb hydrogen, after gamma irradiation it becomes active in relation to hydrogen. Some of rare earths oxides also show selectivity in relation to hydrogen and oxygen depending on a type of irradiation. Thus, it is possible to create different absorbents, depending on a solved problem, using a way or selection of adsorbents, either of radiation type and energy, as a result obtained adsorbents can be used for various ecological purposes

  4. Long-term ageing tests on glazing materials for solar collectors; Langzeit-Alterungsuntersuchung an Abdeckungsmaterialien fuer thermische Sonnenkollektoren

    Energy Technology Data Exchange (ETDEWEB)

    Ruesch, F.; Brunold, S.; Haeuselmann, T.; Frank, E.; Frei, U.

    2008-02-15

    This report made by the Swiss Institute for Solar Technology at the University of Applied Sciences in Rapperswil, Switzerland, for Swiss Federal Office of Energy (SFOE) takes a look at the results of a project that investigated the long-term behaviour of glazing materials for solar collectors. The locations tested and their associated meteorological data are presented and the tests made concerning the optical characteristics of several different types of glazing are discussed. Soiling and degradation are also looked at. An overview of the solar transmission of the various materials is presented. Details on the various materials such as glass, polymethyl metacrylate (PMMA), polycarbonate (PC), fluorised plastics, unsaturated polyester (UP), polyvinyl chloride (PVC) and polyethylene terephthalate (PET) are presented.

  5. Complete braided adsorbent for marine testing to demonstrate 3g-U/kg-adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Janke, Chris [ORNL; Yatsandra, Oyola [ORNL; Mayes, Richard [ORNL; none,; Gill, Gary [PNNL; Li-Jung, Kuo [PNNL; Wood, Jordana [PNNL; Sadananda, Das [ORNL

    2014-04-30

    ORNL has manufactured four braided adsorbents that successfully demonstrated uranium adsorption capacities ranging from 3.0-3.6 g-U/kg-adsorbent in marine testing at PNNL. Four new braided and leno woven fabric adsorbents have also been prepared by ORNL and are currently undergoing marine testing at PNNL.

  6. Deuterium labelling studies with unsaturated acids and nitriles

    International Nuclear Information System (INIS)

    Desai, U.V.; Mane, R.B.

    1986-01-01

    α-Deuteriated α,β-unsaturated acids have been prepared by Knoevenagel condensation of aldehydes with deuteriated malonic acid. The decarboxylation of α,β-unsaturated cyano acid with pyridine/D 2 O yields α- and γ-labelled nitriles. The deuterium incorporation is studied by pmr spectroscopy. (author). 8 refs

  7. Thermodynamics of gas adsorption on solid adsorbents

    International Nuclear Information System (INIS)

    Budrugeac, P.

    1979-01-01

    Starting with several hypotheses about the adsorbtion system and the adsorption phenomenon, a thermodynamic treatment of gas adsorption on solid adsorbants is presented. The relationships for determination from isotherms and calorimetric data of thermodynamic functions are derived. The problem of the phase changes in adsorbed layer is discussed. (author)

  8. 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.

  9. 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.

  10. 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.

  11. 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 

  12. 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.

  13. Transient Point Infiltration In The Unsaturated Zone

    Science.gov (United States)

    Buecker-Gittel, M.; Mohrlok, U.

    The risk assessment of leaking sewer pipes gets more and more important due to urban groundwater management and environmental as well as health safety. This requires the quantification and balancing of transport and transformation processes based on the water flow in the unsaturated zone. The water flow from a single sewer leakage could be described as a point infiltration with time varying hydraulic conditions externally and internally. External variations are caused by the discharge in the sewer pipe as well as the state of the leakage itself. Internal variations are the results of microbiological clogging effects associated with the transformation processes. Technical as well as small scale laboratory experiments were conducted in order to investigate the water transport from an transient point infiltration. From the technical scale experiment there was evidence that the water flow takes place under transient conditions when sewage infiltrates into an unsaturated soil. Whereas the small scale experiments investigated the hydraulics of the water transport and the associated so- lute and particle transport in unsaturated soils in detail. The small scale experiment was a two-dimensional representation of such a point infiltration source where the distributed water transport could be measured by several tensiometers in the soil as well as by a selective measurement of the discharge at the bottom of the experimental setup. Several series of experiments were conducted varying the boundary and initial con- ditions in order to derive the important parameters controlling the infiltration of pure water from the point source. The results showed that there is a significant difference between the infiltration rate in the point source and the discharge rate at the bottom, that could be explained by storage processes due to an outflow resistance at the bottom. This effect is overlayn by a decreasing water content decreases over time correlated with a decreasing infiltration

  14. Abstracts of the symposium on unsaturated flow and transport modeling

    International Nuclear Information System (INIS)

    1982-03-01

    Abstract titles are: Recent developments in modeling variably saturated flow and transport; Unsaturated flow modeling as applied to field problems; Coupled heat and moisture transport in unsaturated soils; Influence of climatic parameters on movement of radionuclides in a multilayered saturated-unsaturated media; Modeling water and solute transport in soil containing roots; Simulation of consolidation in partially saturated soil materials; modeling of water and solute transport in unsaturated heterogeneous fields; Fluid dynamics and mass transfer in variably-saturated porous media; Solute transport through soils; One-dimensional analytical transport modeling; Convective transport of ideal tracers in unsaturated soils; Chemical transport in macropore-mesopore media under partially saturated conditions; Influence of the tension-saturated zone on contaminant migration in shallow water regimes; Influence of the spatial distribution of velocities in porous media on the form of solute transport; Stochastic vs deterministic models for solute movement in the field; and Stochastic analysis of flow and solute transport

  15. 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.

  16. 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...

  17. 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...

  18. 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

  19. Preferential flow occurs in unsaturated conditions

    Science.gov (United States)

    Nimmo, John R.

    2012-01-01

    Because it commonly generates high-speed, high-volume flow with minimal exposure to solid earth materials, preferential flow in the unsaturated zone is a dominant influence in many problems of infiltration, recharge, contaminant transport, and ecohydrology. By definition, preferential flow occurs in a portion of a medium – that is, a preferred part, whether a pathway, pore, or macroscopic subvolume. There are many possible classification schemes, but usual consideration of preferential flow includes macropore or fracture flow, funneled flow determined by macroscale heterogeneities, and fingered flow determined by hydraulic instability rather than intrinsic heterogeneity. That preferential flow is spatially concentrated associates it with other characteristics that are typical, although not defining: it tends to be unusually fast, to transport high fluxes, and to occur with hydraulic disequilibrium within the medium. It also has a tendency to occur in association with large conduits and high water content, although these are less universal than is commonly assumed. Predictive unsaturated-zone flow models in common use employ several different criteria for when and where preferential flow occurs, almost always requiring a nearly saturated medium. A threshold to be exceeded may be specified in terms of the following (i) water content; (ii) matric potential, typically a value high enough to cause capillary filling in a macropore of minimum size; (iii) infiltration capacity or other indication of incipient surface ponding; or (iv) other conditions related to total filling of certain pores. Yet preferential flow does occur without meeting these criteria. My purpose in this commentary is to point out important exceptions and implications of ignoring them. Some of these pertain mainly to macropore flow, others to fingered or funneled flow, and others to combined or undifferentiated flow modes.

  20. Analysis of Adsorbate-Adsorbate and Adsorbate-Adsorbent Interactions to Decode Isosteric Heats of Gas Adsorption.

    Science.gov (United States)

    Madani, S Hadi; Sedghi, Saeid; Biggs, Mark J; Pendleton, Phillip

    2015-12-21

    A qualitative interpretation is proposed to interpret isosteric heats of adsorption by considering contributions from three general classes of interaction energy: fluid-fluid heat, fluid-solid heat, and fluid-high-energy site (HES) heat. Multiple temperature adsorption isotherms are defined for nitrogen, T=(75, 77, 79) K, argon at T=(85, 87, 89) K, and for water and methanol at T=(278, 288, 298) K on a well-characterized polymer-based, activated carbon. Nitrogen and argon are subjected to isosteric heat analyses; their zero filling isosteric heats of adsorption are consistent with slit-pore, adsorption energy enhancement modelling. Water adsorbs entirely via specific interactions, offering decreasing isosteric heat at low pore filling followed by a constant heat slightly in excess of water condensation enthalpy, demonstrating the effects of micropores. Methanol offers both specific adsorption via the alcohol group and non-specific interactions via its methyl group; the isosteric heat increases at low pore filling, indicating the predominance of non-specific interactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Inorganic chemically active adsorbents (ICAAs)

    Energy Technology Data Exchange (ETDEWEB)

    Ally, M.R. [Oak Ridge National Lab., TN (United States); Tavlarides, L.

    1997-10-01

    Oak Ridge National Laboratory (ORNL) researchers are developing a technology that combines metal chelation extraction technology and synthesis chemistry. They begin with a ceramic substrate such as alumina, titanium oxide or silica gel because they provide high surface area, high mechanical strength, and radiolytic stability. One preparation method involves silylation to hydrophobize the surface, followed by chemisorption of a suitable chelation agent using vapor deposition. Another route attaches newly designed chelating agents through covalent bonding by the use of coupling agents. These approaches provide stable and selective, inorganic chemically active adsorbents (ICAAs) tailored for removal of metals. The technology has the following advantages over ion exchange: (1) higher mechanical strength, (2) higher resistance to radiation fields, (3) higher selectivity for the desired metal ion, (4) no cation exchange, (5) reduced or no interference from accompanying anions, (6) faster kinetics, and (7) easy and selective regeneration. Target waste streams include metal-containing groundwater/process wastewater at ORNL`s Y-12 Plant (multiple metals), Savannah River Site (SRS), Rocky Flats (multiple metals), and Hanford; aqueous mixed wastes at Idaho National Engineering Laboratory (INEL); and scrubber water generated at SRS and INEL. Focus Areas that will benefit from this research include Mixed Waste, and Subsurface Contaminants.

  2. 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%.

  3. 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)

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. [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.

  9. 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. 

  10. 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

  11. Interplay of adsorbate-adsorbate and adsorbate-substrate interactions in self-assembled molecular surface nanostructures

    DEFF Research Database (Denmark)

    Schnadt, Joachim; Xu, Wei; Vang, Ronnie Thorbjørn

    2010-01-01

    a large tolerance to monatomic surface steps on the Ag(110) surface. The observed behaviour is explained in terms of strong intermolecular hydrogen bonding and a strong surface-mediated directionality, assisted by a sufficient degree of molecular backbone flexibility. In contrast, the same kind of step......-edge crossing is not observed when the molecules are adsorbed on the isotropic Ag(111) or more reactive Cu(110) surfaces. On Ag(111), similar 1-D assemblies are formed to those on Ag(110), but they are oriented along the step edges. On Cu(110), the carboxylic groups of NDCA are deprotonated and form covalent...... bonds to the surface, a situation which is also achieved on Ag(110) by annealing to 200 degrees C. These results show that the formation of particular self-assembled molecular nanostructures depends significantly on a subtle balance between the adsorbate-adsorbate and adsorbate-substrate interactions...

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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)

  17. 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...

  18. 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.

  19. 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...

  20. 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.

  1. 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...

  2. 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...

  3. 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.

  4. 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.

  5. Alkali metal adsorbate sputtering by molecular impact

    International Nuclear Information System (INIS)

    Moran, J.P.; Wachman, H.Y.; Trilling, L.

    1974-01-01

    An exploratory study of the sputtering by a krypton molecular beam of rubidium adsorbed at low coverage on a tungsten substrate has been described in a previous paper. An extension of this work is reported now

  6. PERVAPORATION USING ADSORBENT-FILLED MEMBRANES

    Science.gov (United States)

    Membranes containing selective fillers, such as zeolites and activated carbon, can improve the separation by pervaporation. Applications of adsorbent-filled membranes in pervaporation have been demonstrated by a number of studies. These applications include removal of organic co...

  7. Chitin Adsorbents for Toxic Metals: A Review

    Directory of Open Access Journals (Sweden)

    Ioannis Anastopoulos

    2017-01-01

    Full Text Available Wastewater treatment is still a critical issue all over the world. Among examined methods for the decontamination of wastewaters, adsorption is a promising, cheap, environmentally friendly and efficient procedure. There are various types of adsorbents that have been used to remove different pollutants such as agricultural waste, compost, nanomaterials, algae, etc., Chitin (poly-β-(1,4-N-acetyl-d-glucosamine is the second most abundant natural biopolymer and it has attracted scientific attention as an inexpensive adsorbent for toxic metals. This review article provides information about the use of chitin as an adsorbent. A list of chitin adsorbents with maximum adsorption capacity and the best isotherm and kinetic fitting models are provided. Moreover, thermodynamic studies, regeneration studies, the mechanism of adsorption and the experimental conditions are also discussed in depth.

  8. Black Sprayable Molecular Adsorber Coating Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective of this technology project is to develop, optimize, and flight qualify a black version of the molecular adsorber coating and a conductive version...

  9. 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.

  10. Methyl iodide tests on used adsorbents

    International Nuclear Information System (INIS)

    Kovach, J.L.

    1993-01-01

    This paper discusses the history of events leading to the current problems in radioiodine test conditions. These radioiodine tests are performed in the adsorbent media from both safety and non-safety related Nuclear Air Treatment Systems (NATS). The main problem addressed is that currently there are still numerous plant technical specifications for NATS which reference outdated test protocols for the surveillance testing of the radioactive methyl iodide performance of the adsorbents. Recommendations for correcting the test condition problems are presented. 7 refs

  11. Properties and selection criteria for adsorbents

    International Nuclear Information System (INIS)

    Wirth, H.

    1976-01-01

    The paper gives a survey of the most important industrial adsorbents and of their suitability for different purposes. With special consideration of activated carbon, the properties and characteristic data are discussed which are used for assessing adsorbents. These, among other things, are as follows: specific surface area, pore size distribution, adsorption isotherms, hydrophobic properties, catalytic properties, chemical resistance, heat resistance, particle size and hardness. (orig.) [de

  12. Protein purification using magnetic adsorbent particles

    DEFF Research Database (Denmark)

    Franzreb, M; Siemann-Herzberg, M.; Hobley, Timothy John

    2006-01-01

    The application of functionalised magnetic adsorbent particles in combination with magnetic separation techniques has received considerable attention in recent years. The magnetically responsive nature of such adsorbent particles permits their selective manipulation and separation in the presence...... separations are fast, gentle, scaleable, easily automated, can achieve separations that would be impossible or impractical to achieve by other techniques, and have demonstrated credibility in a wide range of disciplines, including minerals processing, wastewater treatment, molecular biology, cell sorting...

  13. Mesoporous Silica: A Suitable Adsorbent for Amines

    Directory of Open Access Journals (Sweden)

    Abdollahzadeh-Ghom Sara

    2009-01-01

    Full Text Available Abstract Mesoporous silica with KIT-6 structure was investigated as a preconcentrating material in chromatographic systems for ammonia and trimethylamine. Its adsorption capacity was compared to that of existing commercial materials, showing its increased adsorption power. In addition, KIT-6 mesoporous silica efficiently adsorbs both gases, while none of the employed commercial adsorbents did. This means that KIT-6 Mesoporous silica may be a good choice for integrated chromatography/gas sensing micro-devices.

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. Boundary integral methods for unsaturated flow

    International Nuclear Information System (INIS)

    Martinez, M.J.; McTigue, D.F.

    1990-01-01

    Many large simulations may be required to assess the performance of Yucca Mountain as a possible site for the nations first high level nuclear waste repository. A boundary integral equation method (BIEM) is described for numerical analysis of quasilinear steady unsaturated flow in homogeneous material. The applicability of the exponential model for the dependence of hydraulic conductivity on pressure head is discussed briefly. This constitutive assumption is at the heart of the quasilinear transformation. Materials which display a wide distribution in pore-size are described reasonably well by the exponential. For materials with a narrow range in pore-size, the exponential is suitable over more limited ranges in pressure head. The numerical implementation of the BIEM is used to investigate the infiltration from a strip source to a water table. The net infiltration of moisture into a finite-depth layer is well-described by results for a semi-infinite layer if αD > 4, where α is the sorptive number and D is the depth to the water table. the distribution of moisture exhibits a similar dependence on αD. 11 refs., 4 figs.,

  1. Thermal conductivity of unsaturated clay-rocks

    Directory of Open Access Journals (Sweden)

    D. Jougnot

    2010-01-01

    Full Text Available The parameters used to describe the electrical conductivity of a porous material can be used to describe also its thermal conductivity. A new relationship is developed to connect the thermal conductivity of an unsaturated porous material to the thermal conductivity of the different phases of the composite, and two electrical parameters called the first and second Archie's exponents. A good agreement is obtained between the new model and thermal conductivity measurements performed using packs of glass beads and core samples of the Callovo-Oxfordian clay-rocks at different saturations of the water phase. We showed that the three model parameters optimised to fit the new model against experimental data (namely the thermal conductivity of the solid phase and the two Archie's exponents are consistent with independent estimates. We also observed that the anisotropy of the effective thermal conductivity of the Callovo-Oxfordian clay-rock was mainly due to the anisotropy of the thermal conductivity of the solid phase.

  2. Virus movement in soil during saturated and unsaturated flow.

    Science.gov (United States)

    Lance, J C; Gerba, C P

    1984-02-01

    Virus movement in soil during saturated and unsaturated flow was compared by adding poliovirus to sewage water and applying the water at different rates to a 250-cm-long soil column equipped with ceramic samplers at different depths. Movement of viruses during unsaturated flow of sewage through soil columns was much less than during saturated flow. Viruses did not move below the 40-cm level when sewage water was applied at less than the maximum infiltration rate; virus penetration in columns flooded with sewage was at least 160 cm. Therefore, virus movement in soils irrigated with sewage should be less than in flooded groundwater recharge basins or in saturated soil columns. Management of land treatment systems to provide unsaturated flow through the soil should minimize the depth of virus penetration. Differences in virus movement during saturated and unsaturated flow must be considered in the development of any model used to simulate virus movement in soils.

  3. Unsaturated carbone and allenylidene ruthenium complexes from alkynes

    International Nuclear Information System (INIS)

    Bozek, Yu.L.; Diznev, P.A.

    1995-01-01

    The author's studies aimed at activation of terminal alkynes by metal complexes, reactivity patterns and selective preparations of unsaturated carbene, allenylidene and cumulenylidene derivatives of (arene)ruthenium complexes are reviewed. 48 refs

  4. Synthesis and study of novel silicon-based unsaturated polymers

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jibing [Iowa State Univ., Ames, IA (United States)

    1995-06-19

    Novel unsaturated polymers have been synthesized and studied as precursors to silicon carbide and third order nonlinear optical materials. X ray structures were obtained. Kinetic and mechanistic studies of the unique thermal isomerization of dimethylenedisilacyclobutane to a carbene were conducted.

  5. 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.

  6. 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

  7. Characterization of unsaturated hydraulic conductivity at the Hanford Site

    International Nuclear Information System (INIS)

    Rockhold, M.L.; Fayler, M.J.; Gee, G.W.

    1988-07-01

    This report details some recent field measurements and compares predicted and measured values of hydraulic conductivities for three locations at the Hanford Site. Measurements from small (6-cm-dia) /open quotes/point/close quotes/ and large (2-m by 2-m) /open quotes/plot/close quotes/ areas utilized inflitration and drainage techniques to obtain in situ data for field-saturated and unsaturated hydraulic conductivity. The Guelph permeameter was used for point sampling, and the unsteady drainage-flux method was used on plots for field-saturated and unsaturated hydraulic conductivity measurements. Steady-state techniques were used to measure unsaturated hydraulic conductivities in small columns in the laboratory for one of the three soils tested to provide a comparison with data obtained from the field. Measured unsaturated hydraulic conductivities and those predicted from particle-size distribution and bulk density data agree within one-half to one and one-half orders of magnitude, depending on soil type. To use a particle-size distribution to estimate water retention characteristics and, subsequently, to predict unsaturated hydraulic conductivities, measurements of water-retention characteristics are necessary to determine a parameter value used in one of the models. No single method for measuring or calculating unsaturated hydraulic conductivities was found appropriate for all Hanford Site soils. Ideally, several methods should be used to take advantage of the strengths of each method, considering the data needs and resources available. 45 refs., 24 figs., 19 tabs

  8. Characterization of unsaturated hydraulic conductivity at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Rockhold, M.L.; Fayler, M.J.; Gee, G.W.

    1988-07-01

    This report details some recent field measurements and compares predicted and measured values of hydraulic conductivities for three locations at the Hanford Site. Measurements from small (6-cm-dia) /open quotes/point/close quotes/ and large (2-m by 2-m) /open quotes/plot/close quotes/ areas utilized inflitration and drainage techniques to obtain in situ data for field-saturated and unsaturated hydraulic conductivity. The Guelph permeameter was used for point sampling, and the unsteady drainage-flux method was used on plots for field-saturated and unsaturated hydraulic conductivity measurements. Steady-state techniques were used to measure unsaturated hydraulic conductivities in small columns in the laboratory for one of the three soils tested to provide a comparison with data obtained from the field. Measured unsaturated hydraulic conductivities and those predicted from particle-size distribution and bulk density data agree within one-half to one and one-half orders of magnitude, depending on soil type. To use a particle-size distribution to estimate water retention characteristics and, subsequently, to predict unsaturated hydraulic conductivities, measurements of water-retention characteristics are necessary to determine a parameter value used in one of the models. No single method for measuring or calculating unsaturated hydraulic conductivities was found appropriate for all Hanford Site soils. Ideally, several methods should be used to take advantage of the strengths of each method, considering the data needs and resources available. 45 refs., 24 figs., 19 tabs.

  9. Synergistic Adsorption and Flotation of New Mixed Cationic/Nonionic Collectors on Muscovite

    Directory of Open Access Journals (Sweden)

    Hao Jiang

    2017-05-01

    Full Text Available The mixed cationic collector cetyltrimethylammonium chloride (CTAC and nonionic collector octanol (OCT was found to exhibit a synergistic effect on the flotation and adsorption of muscovite. To understand the underlying synergistic mechanism, flotation, contact angle, surface tension, and adsorption measurements were carried out. The results obtained from flotation measurements indicated that the mixed CTAC/OCT exhibits a better collecting ability than CTAC or OCT. The recovery of muscovite with CTAC only rapidly decreased from 97.25% at pH 2.64 to 75.26% at pH 5.82, followed by a flat horizontal at a pH is higher than 6. In contrast, a high recovery of greater than 85% muscovite was observed using mixed CTAC/OCT at α CTAC = 0.67 (the mole ratio of CTAC:OCT = 2:1 over the investigated pH range. From the surface activity parameters (CMC, γ CMC, Γmax, Amin estimated from surface measurements and interaction parameters (βm, βσ, in addition to the micellar and interfacial compositions ( x 1 m , x 1 σ obtained from the theory of regular solutions, a synergistic effect is evident in the mixed micelle and at the water/air interface. Moreover, the mixed CTAC/OCT at α CTAC = 0.67 exhibited the maximum synergistic interaction. The results obtained from surface tension measurements indicated that the mixed CTAC/OCT exhibits considerably higher surface activities compared to single CTAC or OCT. The contact angle results confirmed that the mixed CTAC/OCT is a better collector than the individual CTAC or OCT for the flotation of muscovite. According to the results obtained from adsorption experiments, compared with that of individual CTAC or OCT, the amounts of CTAC and OCT adsorbed on the muscovite surface are considerably increase in the mixed systems because of co-adsorption. Based on these results, the mixed CTAC/OCT exhibits a remarkable synergistic effect during the flotation and adsorption of muscovite.

  10. Novel Fiber-Based Adsorbent Technology; FINAL

    International Nuclear Information System (INIS)

    Nixon, P.G.; Tsukamoto, T.; Brose, D.J.

    2001-01-01

    The overall of this Department of Energy (DOE) Phase II SBIR program was to develop a new class of highly robust fiber-based adsorbents for recovery of heavy metals from aqueous waste-streams. The fiber-based adsorbents,when commercialized,will be used for clean up metals in aqueous waste-streams emanating from DOE facilities,industry,mining,and groundwater-cleanup operations.The amount of toxic waste released by these streams is of great significance.The U.S.Environment Protection Agency (EPA) reports that in 1990 alone,4.8 billion pounds of toxic chemicals were released into the environment.Of this waste,the metals-containing waste was the second largest contributor,representing 569 million pounds. This report presents the results of the Phase II program,which successfully synthesized noval fiber-based adsorbents for the removal of Group 12 metals(i.e.mercury),Group 14 metals (lead),and Group 10 metals(platinum and palladium) from contaminated groundwater and industrial waste streams.These fiber-based adsorbents are ideally suited for the recovery of metal ions from aqueous waste streams presently not treatable due to the degrading nature of corrosive chemicals or radioactive components in the feed stream. The adsorbents developed in this program rely on chemically resistant and robust carbon fibers and fabrics as supports for metal-ion selective ligands.These adsorbents demonstrate loading capacities and selectivities for metal ions exceeding those of conventional ion-exchange resins.The adsorbents were also used to construct filter modules that demonstrate minimal fouling,minimal compaction,chemical and physical robustness,and regeneration of metal loading capacity without loss of performance

  11. 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)

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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)

  1. Unsaturated Zone Flow Patterns and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    C. Ahlers

    2001-10-17

    This Analysis/Model Report (AMR) documents the development of an expected-case model for unsaturated zone (UZ) flow and transport that will be described in terms of the representativeness of models of the natural system. The expected-case model will provide an evaluation of the effectiveness of the natural barriers, assess the impact of conservatism in the Total System Performance Assessment (TSPA), and support the development of further models and analyses for public confidence building. The present models used in ''Total System Performance Assessment for the Site Recommendation'' (Civilian Radioactive Waste Management System Management and Operating Contractor (CRWMS M&O) 2000 [1532461]) underestimate the natural-barrier performance because of conservative assumptions and parameters and do not adequately address uncertainty and alternative models. The development of an expected case model for the UZ natural barrier addresses issues regarding flow-pattern analysis and modeling that had previously been treated conservatively. This is in line with the Repository Safety Strategy (RSS) philosophy of treating conservatively those aspects of the UZ flow and transport system that are not important for achieving regulatory dose (CRWMS M&O 2000 [153246], Section 1.1.1). The development of an expected case model for the UZ also provides defense-in-depth in areas requiring further analysis of uncertainty and alternative models. In general, the value of the conservative case is to provide a more easily defensible TSPA for behavior of UZ flow and transport processes at Yucca Mountain. This AMR has been prepared in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' (Bechtel SAIC Company (BSC) 2001 [155051], Section 1.3 - Work Package 4301213UMG). The work scope is to examine the data and current models of flow and transport in the Yucca Mountain UZ to identify models and analyses

  2. Unsaturated Zone Flow Patterns and Analysis

    International Nuclear Information System (INIS)

    Ahlers, C.

    2001-01-01

    This Analysis/Model Report (AMR) documents the development of an expected-case model for unsaturated zone (UZ) flow and transport that will be described in terms of the representativeness of models of the natural system. The expected-case model will provide an evaluation of the effectiveness of the natural barriers, assess the impact of conservatism in the Total System Performance Assessment (TSPA), and support the development of further models and analyses for public confidence building. The present models used in ''Total System Performance Assessment for the Site Recommendation'' (Civilian Radioactive Waste Management System Management and Operating Contractor (CRWMS M and O) 2000 [1532461]) underestimate the natural-barrier performance because of conservative assumptions and parameters and do not adequately address uncertainty and alternative models. The development of an expected case model for the UZ natural barrier addresses issues regarding flow-pattern analysis and modeling that had previously been treated conservatively. This is in line with the Repository Safety Strategy (RSS) philosophy of treating conservatively those aspects of the UZ flow and transport system that are not important for achieving regulatory dose (CRWMS M and O 2000 [153246], Section 1.1.1). The development of an expected case model for the UZ also provides defense-in-depth in areas requiring further analysis of uncertainty and alternative models. In general, the value of the conservative case is to provide a more easily defensible TSPA for behavior of UZ flow and transport processes at Yucca Mountain. This AMR has been prepared in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' (Bechtel SAIC Company (BSC) 2001 [155051], Section 1.3 - Work Package 4301213UMG). The work scope is to examine the data and current models of flow and transport in the Yucca Mountain UZ to identify models and analyses where conservatism may be

  3. Synthesis of rearranged unsaturated drimane derivatives

    Directory of Open Access Journals (Sweden)

    Miranda Domingos S. de

    2001-01-01

    Full Text Available A full account to the preparation and application of three appropriately substituted vinylcyclohexenes (2,2-dimethyl-3-vinylcyclohex-3-en-1-ol, 2,2-dimethyl-3-vinylcyclohex-3-en-1-one and 3,3-dimethyl-2-vinylcyclohexene in thermal Diels-Alder reactions with alpha,beta-unsaturated esters (methyl tiglate and methyl angelate is given. This approach delivered the racemic synthesis of ten octalin derivatives bearing a rearranged drimane skeleton (4 diastereomers of 1-methoxycarbonyl-6-hydroxy-1,2,5,5-tetramethyl-1,2,3,5,6,7, 8,8a-octahydronaphthalene; 1-methoxycarbonyl-6-oxo-1,2,5,5-tetramethyl-1,2,3,4,5,6,7,8-octahydronaphthalene; 2-methoxycarbonyl-6-oxo-1,2,5,5-tetramethyl-1,2,3,5,6,7,8,8a-octahydronaphthalene; 3 diastereomers of 1-methoxycarbonyl-1,2,5,5-tetramethyl-1,2,3,5,6,7,8,8a-octahydronaphthalene and 2-methoxycarbonyl-1,2,5,5-tetramethyl-1,2,3,5,6,7,8,8a-octahydronaphthalene . Central synthetic features included preparation of enoltriflates by Stang's protocol and the successful palladium-catalyzed cross-coupling reaction (Stille reaction of the triflate with the tri-n-butylvinylstannane. The octalins relative stereochemistry was unequivocally ascertained by spectroscopic methods and/or X-ray crystallography and these data now stand as useful tools to support the correct assignment of related natural products usually isolated in minute amounts.

  4. Black molecular adsorber coatings for spaceflight applications

    Science.gov (United States)

    Abraham, Nithin S.; Hasegawa, Mark M.; Straka, Sharon A.

    2014-09-01

    The molecular adsorber coating is a new technology that was developed to mitigate the risk of on-orbit molecular contamination on spaceflight missions. The application of this coating would be ideal near highly sensitive, interior surfaces and instruments that are negatively impacted by outgassed molecules from materials, such as plastics, adhesives, lubricants, epoxies, and other similar compounds. This current, sprayable paint technology is comprised of inorganic white materials made from highly porous zeolite. In addition to good adhesion performance, thermal stability, and adsorptive capability, the molecular adsorber coating offers favorable thermal control characteristics. However, low reflectivity properties, which are typically offered by black thermal control coatings, are desired for some spaceflight applications. For example, black coatings are used on interior surfaces, in particular, on instrument baffles for optical stray light control. Similarly, they are also used within light paths between optical systems, such as telescopes, to absorb light. Recent efforts have been made to transform the white molecular adsorber coating into a black coating with similar adsorptive properties. This result is achieved by optimizing the current formulation with black pigments, while still maintaining its adsorption capability for outgassing control. Different binder to pigment ratios, coating thicknesses, and spray application techniques were explored to develop a black version of the molecular adsorber coating. During the development process, coating performance and adsorption characteristics were studied. The preliminary work performed on black molecular adsorber coatings thus far is very promising. Continued development and testing is necessary for its use on future contamination sensitive spaceflight missions.

  5. 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...

  6. 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...

  7. 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.

  8. Experimental study on solar-powered adsorption refrigeration cycle with activated alumina and activated carbon as adsorbent

    Directory of Open Access Journals (Sweden)

    Himsar Ambarita

    2016-03-01

    Full Text Available Typical adsorbent applied in solar-powered adsorption refrigeration cycle is activated carbon. It is known that activated alumina shows a higher adsorption capacity when it is tested in the laboratory using a constant radiation heat flux. In this study, solar-powered adsorption refrigeration cycle with generator filled by different adsorbents has been tested by exposing to solar radiation in Medan city of Indonesia. The generator is heated using a flat-plate type solar collector with a dimension of 0.5 m×0.5 m. Four cases experiments of solar-powered adsorption cycle were carried out, they are with generator filled by 100% activated alumina (named as 100AA, by a mixed of 75% activated alumina and 25% activated carbon (75AA, by a mixed of 25% activated alumina and 75% activated carbon (25AA, and filled by 100% activated carbon. Each case was tested for three days. The temperature and pressure history and the performance have been presented and analyzed. The results show that the average COP of 100AA, 75AA, 25AA, and 100AC is 0.054, 0.056, 0.06, and 0.074, respectively. The main conclusion can be drawn is that for Indonesian condition and flat-plate type solar collector the pair of activated carbon and methanol is the better than activated alumina.

  9. Process for producing zeolite adsorbent and process for treating radioactive liquid waste with the zeolite adsorbent

    International Nuclear Information System (INIS)

    Motojima, K.; Kawamura, F.

    1984-01-01

    Zeolite is contacted with an aqueous solution containing at least one of copper, nickel, cobalt, manganese and zinc salts, preferably copper and nickel salts, particularly preferably copper salt, in such a form as sulfate, nitrate, or chloride, thereby adsorbing the metal on the zeolite in its pores by ion exchange, then the zeolite is treated with a water-soluble ferrocyanide compound, for example, potassium ferrocyanide, thereby forming metal ferrocyanide on the zeolite in its pores. Then, the zeolite is subjected to ageing treatment, thereby producing a zeolite adsorbent impregnated with metal ferrocyanide in the pores of zeolite. The adsorbent can selectively recover cesium with a high percent cesium removal from a radioactive liquid waste containing at least radioactive cesium, for example, a radioactive liquid waste containing cesium and such coexisting ions as sodium, magnesium, calcium and carbonate ions at the same time at a high concentration. The zeolite adsorbent has a stable adsorbability for a prolonged time

  10. Method for modifying trigger level for adsorber regeneration

    Science.gov (United States)

    Ruth, Michael J.; Cunningham, Michael J.

    2010-05-25

    A method for modifying a NO.sub.x adsorber regeneration triggering variable. Engine operating conditions are monitored until the regeneration triggering variable is met. The adsorber is regenerated and the adsorbtion efficiency of the adsorber is subsequently determined. The regeneration triggering variable is modified to correspond with the decline in adsorber efficiency. The adsorber efficiency may be determined using an empirically predetermined set of values or by using a pair of oxygen sensors to determine the oxygen response delay across the sensors.

  11. Adsorbent catalytic nanoparticles and methods of using the same

    Energy Technology Data Exchange (ETDEWEB)

    Slowing, Igor Ivan; Kandel, Kapil

    2017-01-31

    The present invention provides an adsorbent catalytic nanoparticle including a mesoporous silica nanoparticle having at least one adsorbent functional group bound thereto. The adsorbent catalytic nanoparticle also includes at least one catalytic material. In various embodiments, the present invention provides methods of using and making the adsorbent catalytic nanoparticles. In some examples, the adsorbent catalytic nanoparticles can be used to selectively remove fatty acids from feedstocks for biodiesel, and to hydrotreat the separated fatty acids.

  12. 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.

  13. 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)

  14. 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.

  15. 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...

  16. 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.

  17. Unsaturated zone investigation at the radioactive waste storage facility site

    Energy Technology Data Exchange (ETDEWEB)

    Skuratovic, Zana; Mazeika, Jonas; Petrosius, Rimantas; Jakimaviciute-Maseliene, Vaidote [Nature Research Centre, Akademijos St. 2, LT-08412, Vilnius (Lithuania); Klizas, Petras; Mokrik, Robert [Vilnius University, M.K. Ciurlionio St. 21/27, LT-03101 Vilnius (Lithuania)

    2014-07-01

    Unsaturated zone is an important part of water circulation cycle and an integral part of many hydrological and hydrogeological factors and processes. The soils of unsaturated zone are regarded as the first natural barrier to a large extent able to limit the spread of contaminants. Nuclear waste disposal site (Maisiagala radioactive waste storage facility site) was analysed in terms of the moisture movement through the unsaturated zone. Extensive data sets of the hydraulic properties, water content and isotope composition have been collected and summarized. The main experimental and observational tasks included the collection of soil samples; determination of the physical properties and the hydraulic conductivity values of soil samples, moisture extraction from the soil sample for isotopic studies; observation of the groundwater dynamics at the Maisiagala piezometer; groundwater sampling for isotopic analysis ({sup 3}H, {sup 18}O/{sup 16}O, {sup 2}H/{sup 1}H ); and monthly precipitation isotopic analysis. Distribution features of globally widespread radionuclide tritium ({sup 3}H) and the water molecule tracer isotopes in precipitation, unsaturated zone soil moisture profiles and groundwater were determined. It was used the well-known unsaturated flow and transport model of HYDRUS-1D (Simunek et al., 2008). In this study, van Genuchten equations for the retention and conductivity estimations have been used. The retention characteristics and van Genuchten model parameters were estimated internally by HYDRUS based on the empirical equations involved in the program. Basic inputs of the tritium transport simulation are the tritium input function and meteorological variables (precipitation and potential evapotranspiration). In order to validate the representativeness of the hydraulic parameters, the model has been used to estimate the tritium distribution in the unsaturated zone, which properly represents the dynamics of the unsaturated zone. The uniformity of the daily

  18. 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

  19. 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....

  20. 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.)

  1. 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.

  2. 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...

  3. 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)

  4. The Dynamics and Structures of Adsorbed Surfaces

    DEFF Research Database (Denmark)

    Nielsen, M; Ellenson, W. D.; McTague, J. P.

    1978-01-01

    . Elastic neutron diffraction measurements, determining the two-dimensional structural ordering of the adsorbed films, have been performed on layers of N2, Ar, H2, D2, O2, Kr, and He. Measurements on layers of larger molecules such as CD4 and ND3 have also been reported. Inelastic neutron scattering...... measurements, studying the dynamics of the adsorbed films are only possible in a few especially favourable cases such as 36Ar and D2 films, where the coherent phonon scattering cross-sections are very large. In other cases incoherent scattering from hydrogen can give information about e.g. the mobility...

  5. Waste migration in shallow burial sites under unsaturated flow conditions

    International Nuclear Information System (INIS)

    Eicholz, G.G.; Whang, J.

    1987-01-01

    Unsaturated conditions prevail in many shallow-land burial sites, both in arid and humid regions. Unless a burial site is allowed to flood and possibly overflow, a realistic assessment of any migration scenario must take into account the conditions of unsaturated flow. These are more difficult to observe and to model, but introduce significant changes into projected rates of waste leaching and waste migration. Column tests have been performed using soils from the Southeastern coastal plain to observe the effects of varying degrees of ''unsaturation'' on the movement of radioactive tracers. The moisture content in the columns was controlled by maintaining various levels of hydrostatic suction on soil columns whose hydrodynamic characteristics had been determined carefully. Tracer tests, employing Cs-137, I-131 and Ba-133 were used to determine migration profiles and to follow their movement down the column for different suction values. A calculational model has been developed for unsaturated flow and seems to match the observations fairly well. It is evident that a full description of migration processes must take into account the reduced migration rates under unsaturated conditions and the hysteresis effects associated with wetting-drying cycles

  6. Stochastic analysis of radionuclide migration in saturated-unsaturated soils

    International Nuclear Information System (INIS)

    Kawanishi, Moto

    1988-01-01

    In Japan, LLRW (low level radioactive wastes) generated from nuclear power plants shall be started to store concentrically in the Shimokita site from 1990, and those could be transformed into land disposal if the positive safety is confirmed. Therefore, it is hoped that the safety assessment method shall be successed for the land disposal of LLRW. In this study, a stochastic model to analyze the radionuclide migration in saturated-unsaturated soils was constructed. The principal results are summarized as follows. 1) We presented a generalized idea for the modeling of the radionuclide migration in saturated-unsaturated soils as an advective-dispersion phenomena followed by the decay of radionuclides and those adsorption/desorption in soils. 2) Based on the radionuclide migration model mentioned above, we developed a stochastic analysis model on radionuclide migration in saturated-unsaturated soils. 3) From the comparison between the simulated results and the exact solution on a few simple one-dimensional advective-dispersion problems of radionuclides, the good validity of this model was confirmed. 4) From the comparison between the simulated results by this model and the experimental results of radionuclide migration in a one-dimensional unsaturated soil column with rainfall, the good applicability was shown. 5) As the stochastic model such as this has several advantages that it is easily able to represent the image of physical phenomena and has basically no numerical dissipation, this model should be more applicable to the analysis of the complicated radionuclide migration in saturated-unsaturated soils. (author)

  7. Analysis of rainfall infiltration law in unsaturated soil slope.

    Science.gov (United States)

    Zhang, Gui-rong; Qian, Ya-jun; Wang, Zhang-chun; Zhao, Bo

    2014-01-01

    In the study of unsaturated soil slope stability under rainfall infiltration, it is worth continuing to explore how much rainfall infiltrates into the slope in a rain process, and the amount of rainfall infiltrating into slope is the important factor influencing the stability. Therefore, rainfall infiltration capacity is an important issue of unsaturated seepage analysis for slope. On the basis of previous studies, rainfall infiltration law of unsaturated soil slope is analyzed. Considering the characteristics of slope and rainfall, the key factors affecting rainfall infiltration of slope, including hydraulic properties, water storage capacity (θs - θr), soil types, rainfall intensities, and antecedent and subsequent infiltration rates on unsaturated soil slope, are discussed by using theory analysis and numerical simulation technology. Based on critical factors changing, this paper presents three calculation models of rainfall infiltrability for unsaturated slope, including (1) infiltration model considering rainfall intensity; (2) effective rainfall model considering antecedent rainfall; (3) infiltration model considering comprehensive factors. Based on the technology of system response, the relationship of rainfall and infiltration is described, and the prototype of regression model of rainfall infiltration is given, in order to determine the amount of rain penetration during a rain process.

  8. Repository site data report for unsaturated tuff, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Tien, P.L.; Updegraff, C.D.; Siegel, M.D.; Wahi, K.K.; Guzowski, R.V.

    1985-11-01

    The US Department of Energy is currently considering the thick sequences of unsaturated, fractured tuff at Yucca Mountain, on the southwestern boundary of the Nevada Test Site, as a possible candidate host rock for a nuclear-waste repository. Yucca Mountain is in one of the most arid areas in the United States. The site is within the south-central part of the Great Basin section of the Basin and Range physiographic province and is located near a number of silicic calderas of Tertiary age. Although localized zones of seismic activity are common throughout the province, and faults are present at Yucca Mountain, the site itself is basically aseismic. No data are available on the composition of ground water in the unsaturated zone at Yucca Mountain. It has been suggested that the composition is bounded by the compositions of water from wells USW-H3, UE25p-1, J-13, and snow or rain. There are relatively few data available from Yucca Mountain on the moisture content and saturation, hydraulic conductivity, and characteristic curves of the unsaturated zone. The available literature on thermomechanical properties of tuff does not always distinguish between data from the saturated zone and data from the unsaturated zone. Geochemical, hydrologic, and thermomechanical data available on the unsaturated tuffs of Yucca Mountain are tabulated in this report. Where the data are very sparse, they have been supplemented by data from the saturated zone or from areas other than Yucca Mountain. 316 refs., 58 figs., 37 tabs

  9. Repository site data report for unsaturated tuff, Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Tien, P.L.; Updegraff, C.D.; Siegel, M.D.; Wahi, K.K.; Guzowski, R.V.

    1985-11-01

    The US Department of Energy is currently considering the thick sequences of unsaturated, fractured tuff at Yucca Mountain, on the southwestern boundary of the Nevada Test Site, as a possible candidate host rock for a nuclear-waste repository. Yucca Mountain is in one of the most arid areas in the United States. The site is within the south-central part of the Great Basin section of the Basin and Range physiographic province and is located near a number of silicic calderas of Tertiary age. Although localized zones of seismic activity are common throughout the province, and faults are present at Yucca Mountain, the site itself is basically aseismic. No data are available on the composition of ground water in the unsaturated zone at Yucca Mountain. It has been suggested that the composition is bounded by the compositions of water from wells USW-H3, UE25p-1, J-13, and snow or rain. There are relatively few data available from Yucca Mountain on the moisture content and saturation, hydraulic conductivity, and characteristic curves of the unsaturated zone. The available literature on thermomechanical properties of tuff does not always distinguish between data from the saturated zone and data from the unsaturated zone. Geochemical, hydrologic, and thermomechanical data available on the unsaturated tuffs of Yucca Mountain are tabulated in this report. Where the data are very sparse, they have been supplemented by data from the saturated zone or from areas other than Yucca Mountain. 316 refs., 58 figs., 37 tabs.

  10. Theoretical Insight of Physical Adsorption for a Single Component Adsorbent + Adsorbate System: II. The Henry Region

    KAUST Repository

    Chakraborty, Anutosh

    2009-07-07

    The Henry coefficients of a single component adsorbent + adsorbate system are calculated from experimentally measured adsorption isotherm data, from which the heat of adsorption at zero coverage is evaluated. The first part of the papers relates to the development of thermodynamic property surfaces for a single-component adsorbent + adsorbate system1 (Chakraborty, A.; Saha, B. B.; Ng, K. C.; Koyama, S.; Srinivasan, K. Langmuir 2009, 25, 2204). A thermodynamic framework is presented to capture the relationship between the specific surface area (Ai) and the energy factor, and the surface structural and the surface energy heterogeneity distribution factors are analyzed. Using the outlined approach, the maximum possible amount of adsorbate uptake has been evaluated and compared with experimental data. It is found that the adsorbents with higher specific surface areas tend to possess lower heat of adsorption (ΔH°) at the Henry regime. In this paper, we have established the definitive relation between Ai and ΔH° for (i) carbonaceous materials, metal organic frameworks (MOFs), carbon nanotubes, zeolites + hydrogen, and (ii) activated carbons + methane systems. The proposed theoretical framework of At and AH0 provides valuable guides for researchers in developing advanced porous adsorbents for methane and hydrogen uptake. © 2009 American Chemical Society.

  11. Volatile organic compounds adsorption using different types of adsorbent

    Directory of Open Access Journals (Sweden)

    Pimanmes Chanayotha

    2014-09-01

    Full Text Available Adsorbents were synthesized from coconut shell, coal and coke by pyrolysis followed by chemical activation process. These synthesized materials were used as adsorbents in adsorption test to determine the amount of volatile organic compounds (VOCs namely, 2-Hydroxyethyl methacrylate (HEMA, Octamethylcyclotetrasiloxane and Alkanes standard solution (C8-C20. The adsorption capacities of both synthesized adsorbents and commercial grade adsorbents (Carbotrap™ B and Carbotrap™ C were also compared. It was found that adsorbent A402, which was produced from coconut shell, activated with 40% (wt. potassium hydroxide and at activating temperature of 800°C for 1 hr, could adsorb higher amount of both HEMA and Octamethylcyclotetrasiloxane than other synthesized adsorbents. The maximum adsorption capacity of adsorbent A402 in adsorbing HEMA and Octamethylcyclotetrasiloxane were 77.87% and 50.82% respectively. These adsorption capabilities were 79.73% and 70.07% of the adsorption capacity of the commercial adsorbent Carbotrap™ B respectively. All three types of the synthesized adsorbent (A402, C302, C402 showed the capability to adsorb alkanes standard solution through the range of C8-C20 . However, their adsorption capacities were high in a specific range of C10-C11. The result from the isotherm plot was indicated that surface adsorption of synthesized adsorbent was isotherm type I while the surface adsorption of commercial adsorbent was isotherm type III.

  12. 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

  13. 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...

  14. 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...

  15. 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)

  16. 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.

  17. 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.

  18. The effect of water molecules on the thiol collector interaction on the galena (PbS) and sphalerite (ZnS) surfaces: A DFT study

    Energy Technology Data Exchange (ETDEWEB)

    Long, Xianhao [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); Chen, Ye, E-mail: fby18@126.com [College of Resources and Metallurgy, Guangxi University, Nanning 530004 (China); Chen, Jianhua, E-mail: jhchen@gxu.edu.cn [School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004 (China); College of Resources and Metallurgy, Guangxi University, Nanning 530004 (China); Xu, Zhenghe; Liu, Qingxia [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 2V4 (Canada); Du, Zheng [National Supercomputing Center in Shenzhen, Shenzhen 518055 (China)

    2016-12-15

    Highlights: • Water adsorption has a greater effect on the electron distribution of ZnS surface than PbS surface. • Water adsorption decreases the reactivity of ZnS surface atoms but improves that of PbS. • Thiol collectors cannot interact with the hydrated ZnS surface. • The hydration has little influence on the interaction of thiol collectors with PbS surface. - Abstracts: In froth flotation the molecular interaction between reagents and mineral surfaces take place at the solid liquid interface. In this paper, the effect of water molecule on the three typical thiol collectors (xanthate, dithiocarbomate and dithiophosphate) interactions at the galena (PbS) and sphalerite (ZnS) surfaces has been studied adopting density functional theory (DFT). The results suggests that the presence of water molecule shows a greater influence on the electron distribution of ZnS surface than PbS surface, and reduce the reactivity of ZnS surface atoms but improves the reactivity of PbS surface atoms during the reaction with xanthate. Water adsorption could also reduce the covalent binding between Zn and S atoms but have little influence on Pb-S bond. In the presence of water, xanthate, dithiocarbomate (DTC) and dithiophosphate (DTP) could not adsorb on the sphalerite surface. And for galena (PbS) surface, the interaction of DTP is the strongest, then the DTC and the interaction of xanthate is the weakest. These results agree well with the flotation practice.

  19. Photoemission spectroscopy of surfaces and adsorbates

    International Nuclear Information System (INIS)

    Chiang, T.C.; Kaindl, G.; Himpsel, F.J.; Eastman, D.E.

    1982-01-01

    Core level photoelectron spectroscopy is providing new information concerning the electronic properties of adsorbates and surfaces. Several examples will be discussed, including studies of adsorbed rare gas submonolayers and multilayers as well as clean metal surfaces. For rare gas multilayers adsorbed on metal surfaces, the photoelectrons and Auger electrons exhibit well-resolved increases in kinetic energy with decreasing distance between the excited atom and the substrate, allowing a direct labeling of the layers. These energy shifts are mainly due to the substrate screening effects, and can be described well by an image-charge model. For a Kr/Xe bilayer system prepared by first coating a Pd substrate with a monolayer of Kr and then overcoating with a layer of Xe, a thermally activated layer inversion process is observed when the temperature is raised, with Xe coming in direct contact with the substrate. For rare gas submonolayers adsorbed on the Al(111) surface, coverage-dependent core level shift and work function measurements provide information about the adatom spatial distributions, polarizabilities, and dipole moments for the ground and excited states. We have also studied the 2p core level shifts for a clean Al(001) surface relative to the bulk. The shifts have a large contribution from the initial-state effects

  20. Heterogeneous membranes filled with hypercrosslinked microparticle adsorbent

    Czech Academy of Sciences Publication Activity Database

    Hradil, Jiří; Krystl, V.; Hrabánek, P.; Bernauer, B.; Kočiřík, Milan

    2005-01-01

    Roč. 65, 1-2 (2005), s. 57-68 ISSN 1381-5148 R&D Projects: GA ČR GA104/03/0680 Institutional research plan: CEZ:AV0Z40500505 Keywords : heterogeneous membranes * hypercrosslinked adsorbent * microparticle s Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.565, year: 2005

  1. A framework for the behaviour of unsaturated expansive clays

    International Nuclear Information System (INIS)

    Gens, A.; Alonso, E.E.

    1992-01-01

    The paper presents a framework for describing the mechanical behaviour of unsaturated expansive clays. It is an extension of an existing formulation developed for unsaturated soils of low activity. The extended framework is based on the distinction within the material of a microstructural level where the basic swelling of the active minerals takes place, and a macrostructural level responsible for major structural rearrangements. Bu adopting simple assumptions concerning the coupling between the two levels, it is possible to reproduce major features of the behaviour of unsaturated expansive clays. Some selected qualitative comparisons between model predictions and experimental results reported in the literature are presented. Despite the simplified hypotheses made, a very encouraging agreement is obtained

  2. Second European Conference on Unsaturated Soils, E-UNSAT 2012

    CERN Document Server

    Jommi, Cristina; D’Onza, Francesca; Unsaturated Soils: Research and Applications

    2012-01-01

    These volumes contain the contributions to the Second European Conference on Unsaturated Soils, E-UNSAT 2012, held in Napoli, Italy, in June 2012. The event is the second of a series of European conferences, and follows the first successful one, organised in Durham, UK, in 2008. The conference series is supported by Technical Committee 106 of the International Society of Soil Mechanics and Geotechnical Engineering on Unsaturated Soils. The published contributions were selected after a careful peer-review process. A collection of more than one hundred papers is included, addressing the three thematic areas experimental, including advances in testing techniques and soil behaviour, modelling, covering theoretical and constitutive issues together with numerical and physical modelling, and engineering, focusing on approaches, case histories and geo-environmental themes. The areas of application of the papers embrace most of the geotechnical problems related to unsaturated soils. Increasing interest in geo-environm...

  3. 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...

  4. 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,...

  5. Graphene Oxide Affects Mobility and Antibacterial Ability of Levofloxacin and Ciprofloxacin in Saturated and Unsaturated Porous Media

    Science.gov (United States)

    Kaixuan, S.

    2017-12-01

    Understand the fate and impact of fluoroquinolone antibiotics (FQs) in soil and groundwater systems is critical to the safety of ecosystem and public health. In this work, laboratory batch sorption, column transport, and bacterial growth experiments were conducted to improve current understanding of the interactions between two typical FQs (levofloxacin (LEV) and ciprofloxacin (CIP)) and graphene oxide (GO) in quartz sand media under various conditions. Studies showed that both GO and quartz sand adsorbed LEV and CIP in aqueous solutions and sand was capable to compete with GO for the antibiotics. While GO showed much larger sorption capacity, the sand had stronger sorption affinity to the two antibiotics. As a result, neither LEV nor CIP showed any signs of breakthrough in saturated or unsaturated porous media. When the two antibiotics were premixed with GO, their mobility in porous media increased for both saturate and unsaturated conditions and the amount of LEV or CIP in the effluents increased with the increasing of initial GO concentration. During their transport in saturated porous media, some of the GO-bound antibiotics, especially those sorbed via relatively weak interactions, transferred from GO to the quartz sand. Under unsaturated conditions, GO-bound LEV might also transfer from GO to the air-water interface due to the strong affiliation between LEV and air-water interface. Sorption onto GO reduced the antibacterial ability of LEV and CIP, however, the GO-bound antibiotics still effectively inhibited the growth of E coli. Findings from this work indicated that mobile GO affected not only the mobility but also the ecotoxicity of LEV and CIP in porous media.

  6. 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.

  7. 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...

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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’

  18. 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.

  19. 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, ...

  20. 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.

  1. 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.

  2. Electrokinetic remediation of anionic contaminants from unsaturated soils

    International Nuclear Information System (INIS)

    Lindgren, E.R.; Kozak, M.W.; Mattson, E.D.

    1992-01-01

    Heavy-metal contamination of soil and groundwater is a widespread problem in the DOE weapons complex, and for the nation as a whole. Electrokinetic remediation is one possible technique for in situ removal of such contaminants from unsaturated soils. In previous studies at Sandia National Laboratories, the electromigration of chromate ions and anionic dye ions have been demonstrated. This paper reports on a series of experiments that were conducted to study the effect of moisture content on the electromigration rate of anionic contaminants in unsaturated soil and determine the limiting moisture content for which electromigration occurs

  3. Process for making unsaturated hydrocarbons using microchannel process technology

    Science.gov (United States)

    Tonkovich, Anna Lee [Dublin, OH; Yuschak, Thomas [Lewis Center, OH; LaPlante, Timothy J [Columbus, OH; Rankin, Scott [Columbus, OH; Perry, Steven T [Galloway, OH; Fitzgerald, Sean Patrick [Columbus, OH; Simmons, Wayne W [Dublin, OH; Mazanec, Terry Daymo, Eric

    2011-04-12

    The disclosed invention relates to a process for converting a feed composition comprising one or more hydrocarbons to a product comprising one or more unsaturated hydrocarbons, the process comprising: flowing the feed composition and steam in contact with each other in a microchannel reactor at a temperature in the range from about 200.degree. C. to about 1200.degree. C. to convert the feed composition to the product, the process being characterized by the absence of catalyst for converting the one or more hydrocarbons to one or more unsaturated hydrocarbons. Hydrogen and/or oxygen may be combined with the feed composition and steam.

  4. The adsorber loop concept for the contact between seawater and adsorber granulate

    International Nuclear Information System (INIS)

    Koske, P.H.; Ohlrogge, K.

    1984-01-01

    The present paper deals with the so-called ''adsorber loop concept'' in which the adsorber granulate is carried along with the seawater to be processed in a loop-like configuration and is separated again from the depleted water before this is leaving the adsorption unit. This concept enables high seawater velocities thus reducing the required bed area. Theoretical considerations are presented together with experimental results from field tests. (orig.) [de

  5. Electronic spectral properties of surfaces and adsorbates and atom-adsorbate van der Waals interactions

    International Nuclear Information System (INIS)

    Lovric, D.; Gumhalter, B.

    1988-01-01

    The relevance of van der Waals interactions in the scattering of neutral atoms from adsorbates has been recently confirmed by highly sensitive molecular-beam techniques. The theoretical descriptions of the collision dynamics which followed the experimental studies have necessitated very careful qualitative and quantitative examinations and evaluations of the properties of atom-adsorbate van der Waals interactions for specific systems. In this work we present a microscopic calculation of the strengths and reference-plane positions for van der Waals potentials relevant for scattering of He atoms from CO adsorbed on various metallic substrates. In order to take into account the specificities of the polarization properties of real metals (noble and transition metals) and of chemisorbed CO, we first calculate the spectra of the electronic excitations characteristic of the respective electronic subsystems by using various data sources available and combine them with the existing theoretical models. The reliability of the calculated spectra is then verified in each particular case by universal sum rules which may be established for the electronic excitations of surfaces and adsorbates. The substrate and adsorbate polarization properties which derive from these calculations serve as input data for the evaluation of the strengths and reference-plane positions of van der Waals potentials whose computed values are tabulated for a number of real chemisorption systems. The implications of the obtained results are discussed in regard to the atom-adsorbate scattering cross sections pertinent to molecular-beam scattering experiments

  6. 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

  7. Determination Of Adsorption And Paraffin Characterization Of Treatment To Adsorb Vegetable Oil

    International Nuclear Information System (INIS)

    Aminah, Neneng Siti; Mulijani, Sri; Sudirman; Ridwan

    2004-01-01

    Using vegetable oil repeatedly, beside affect on quality decline of food and the oil itself, it is harmful to human health. Some poisoning and carcinogenic symptom were founded with experiment using animals. According to that fact, the aim of the research is using paraffin and candle to adsorb used vegetable oil and to convert into solid sample, so it can be easily wasted. At first, 2 g of sample was poured into the heated oil, with gently stirrer until it turned cold and harden. Each sample and standard before and after treatment was characterized with Ftir, XRD, and DSc. The result shows that paraffins adsorbs 40 ml used vegetable oil with 2 g sample in proportion. That proportion is lower than the standard which can adsorb 66.67 ml vegetable oil in the same weight sample. The difference of paraffin and standard is caused by physical properties within that two materials, and it can be explained by Ftir, X-Ray Diffraction (XRD) and differential scanning calorimetry (DSc). Based on result of Ftir analysis, standard consented of saturated hydrocarbon compound (alkanes) whereas paraffin consisted of unsaturated hydrocarbon compound (alkenes). Infrared spectrum after treatment showed the changes of compound, O-H and esters group were formed and it shows characterised the adsorption process. The result of DSc analysis showed that crystalline the melting point of standard is 75,3 o C and paraffin is 54,17 o C. The result of analysis XRD, described that standard and paraffin before treatment are crystalline whereas after treatment are am orf

  8. Visualization of microscale phase displacement proceses in retention and outflow experiments: nonuniquensess of unsaturated flow properties

    DEFF Research Database (Denmark)

    Mortensen, Annette Pia; Glass, R.J.; Hollenbeck, K.J.

    2001-01-01

    -scale heterogeneities. Because the mixture of these microscale processes yields macroscale effective behavior, measured unsaturated flow properties are also a function of these controls. Such results suggest limitations on the current definitions and uniqueness of unsaturated hydraulic properties....

  9. Unsaturated Fatty Acid Esters Metathesis Catalyzed by Silica Supported WMe5

    KAUST Repository

    Riache, Nassima; Callens, Emmanuel; Talbi, Karima; Basset, Jean-Marie

    2015-01-01

    Metathesis of unsaturated fatty acid esters (FAEs) by silica supported multifunctional W-based catalyst is disclosed. This transformation represents a novel route towards unsaturated di-esters. Especially, the self-metathesis of ethyl undecylenate

  10. Unsaturated soil moisture drying and wetting diffusion coefficient measurements in the laboratory.

    Science.gov (United States)

    2009-09-01

    ABSTRACTTransient moisture flow in an unsaturated soil in response to suction changes is controlled by the unsaturated moisture diffusion coefficient. The moisture diffusion coefficient can be determined by measuring suction profiles over time. The l...

  11. 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.

  12. 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.

  13. Removal of methylene blue from its aqueous solution by froth flotation: hydrophobic silica nanoparticle as a collector

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Nan; Liu, Wei; Ding, Linlin; Wu, Zhaoliang, E-mail: zhaoliangwu-hebut@163.com; Yin, Hao; Huang, Di; Li, Hongzhen; Jin, Lixue; Zheng, Huijie [Hebei University of Technology, School of Chemical Engineering and Technology (China)

    2017-02-15

    Dye pollution has been a severe problem faced by worldwide environmentalists. The use of nanoparticles as adsorbents has attracted widespread interests for effectively removing dyes, while the separation of them from an aqueous solution is a difficult and important subject. For achieving the simultaneous removal of methylene blue (MB) and nanoadsorbents, this work utilized a commercial hydrophobic silica nanoparticle (SNP) (200.0 ± 10.0 nm in average particle size) as a collector and then developed a novel froth flotation technology without using any surfactants. Under the suitable conditions of anhydrous ethanol dosage of 8 mL, pH of 9.0, SNP concentration of 600 mg/L, and flotation column height of 600 mm, the removal efficiencies of MB and SNPs and the volume ratio reached 91.1 ± 4.6%, 93.9 ± 4.7%, and 10.5 ± 0.5, respectively. Subsequently, the recovered MB-adsorbed SNPs in the foamate were separated by free setting due to their high concentration and massive agglomeration. After free setting, MB could be effectively separated from the recovered MB-adsorbed SNPs by using ethanol at pH 2.0 and repeating five cycles of washing-centrifugation. Additionally, the regenerated SNPs could be reused for removing MB up to five times. Overall, this work had a significant meaning for the treatment of dye-contaminated wastewaters.

  14. Modification of unsaturated polyester resins using nano-size core ...

    African Journals Online (AJOL)

    Modification of unsaturated polyester resins using nano-size core-shell particles. MO Munyati, PA Lovell. Abstract. No Abstract Available Journal of Science and Technology Special Edition 2004: 24-31. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  15. SYNTHESIS OF 2,3-UNSATURATED FURANIC HEX- AND PENT ...

    African Journals Online (AJOL)

    a

    [12] and reduction in two steps of 3-(2-furyl)-acrolein[13] in good yields. The reaction of alcohols 2a-e with glucal 1, carried out in presence of boron trifluoride [7]. (method A), ferric chloride [11] (method B) and CAN [10] (method C), afforded the corresponding 2,3-unsaturated glucopyranosides 3a-e (Table 1). Table 1.

  16. Beaded Fiber Mats of PVA Containing Unsaturated Heteropoly Salt

    Institute of Scientific and Technical Information of China (English)

    Guo Cheng YANG; Yan PAN; Jian GONG; Chang Lu SHAO; Shang Bin WEN; Chen SHAO; Lun Yu QU

    2004-01-01

    Poly(vinyl alcohol) (PVA) fiber mats containing unsaturated heteropoly salt was prepared for the first time. IR, X-ray diffraction and SEM photographs characterized the beaded fiber mats.The viscoelasticity and the conductivity of the solution were the key factors that influence the formation of the beaded fiber mats.

  17. Effect Of Intraruminal Infussion Of Saturated And Unsaturated Fatty ...

    African Journals Online (AJOL)

    This study describes the effect of intraruminal infusion of diferent proportions of palmitic (saturated fatty acid) and linolenic (unsaturated fatty acid) on rumen degradability of organic matter fraction of Pennisetium purpureum, total volatile fatty acid and total methane productions in West African Dwarf sheep. Five combination ...

  18. Fe-Catalyzed Oxidative Cleavage of Unsaturated Fatty Acids

    NARCIS (Netherlands)

    Spannring, P.

    2013-01-01

    The oxidative cleavage of unsaturated fatty acids into aldehydes or carboxylic acids gives access to valuable products. The products can be used as chemical building blocks, as emulsifiers or in the paint or polymer industry. Ozonolysis is applied industrially to cleave the fatty acid oleic acid

  19. Unsaturated and Saturated Permeabilities of Fiber Reinforcement: Critics and Suggestions

    Directory of Open Access Journals (Sweden)

    Chung Hae ePARK

    2015-04-01

    Full Text Available In general, permeability measurement results show a strong scattering according to the measurement method, the type of test fluid and the fluid injection condition, even though permeability is regarded as a unique property of porous medium. In particular, the discrepancy between the unsaturated and saturated permeabilities for the same fabric has been widely reported. In the literature, relative permeability has been adopted to model the unsaturated flow. This approach has some limits in the modeling of double-scale porosity medium. We address this issue of permeability measurement by rigorously examining the mass conservation condition. Finally, we identify that the pressure gradient is non-linear with positive curvature in the unsaturated flow and a misinterpretation of pressure gradient is the main reason for the difference between the saturated and unsaturated permeabilities of the same fiber reinforcement. We propose to use a fixed value of permeability and to modify the mass conservation equation if there are air voids which are entrapped inside the fiber tow. Finally, we also suggest some guidelines and future perspectives to obtain more consistent permeability measurement results.

  20. Review of Upscaling Methods for Describing Unsaturated Flow

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Brian D.

    2000-09-26

    Representing samll-scale features can be a challenge when one wants to model unsaturated flow in large domains. In this report, the various upscaling techniques are reviewed. The following upscaling methods have been identified from the literature: stochastic methods, renormalization methods, volume averaging and homogenization methods. In addition, a final technique, full resolution numerical modeling, is also discussed.

  1. Low temperature irradiation of vitrifiable mixtures of unsaturated monomers

    International Nuclear Information System (INIS)

    Kaetsu, I.; Ito, A.; Hayashi, K.

    1975-01-01

    A specific mixture containing at least one polymerizable unsaturated monomer which is not vitrifiable by itself can advantageously be polymerized by irradiating the mixture at a temperature not higher than 100 0 C above glass transition temperature of the mixture with an ionizing radiation and/or a light. 12 claims, 6 drawings, figures

  2. Numerical convergence improvements for porflow unsaturated flow simulations

    Energy Technology Data Exchange (ETDEWEB)

    Flach, Greg [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-08-14

    Section 3.6 of SRNL (2016) discusses various PORFLOW code improvements to increase modeling efficiency, in preparation for the next E-Area Performance Assessment (WSRC 2008) revision. This memorandum documents interaction with Analytic & Computational Research, Inc. (http://www.acricfd.com/default.htm) to improve numerical convergence efficiency using PORFLOW version 6.42 for unsaturated flow simulations.

  3. ENGINEERING ISSUE: IN SITU BIOREMEDIATION OF CONTAMINATED UNSATURATED SUBSURFACE SOILS

    Science.gov (United States)

    An emerging technology for the remediation of unsaturated subsurface soils involves the use of microorganisms to degrade contaminants which are present in such soils. Understanding the processes which drive in situ bioremediation, as well as the effectiveness and efficiency of th...

  4. Movement of pentachlorophenol in unsaturated soil by electrokinetics

    Energy Technology Data Exchange (ETDEWEB)

    Harbottle, M.; Sills, G. [Dept. of Engineering Science, Oxford (United Kingdom); Jackman, S. [Dept. of Engineering Science, Oxford (United Kingdom)]|[NERC Centre for Ecology and Hydrology, Oxford (United Kingdom); Thompson, I. [NERC Centre for Ecology and Hydrology, Oxford (United Kingdom)

    2001-07-01

    Electrokinetic experiments have been performed on unsaturated natural soil specimens artificially contaminated with pentachlorophenol. Movement of pentachlorophenol within the soil mass has been demonstrated, but no contaminant was discovered in any effluent fluids. The results indicate that it may be possible to improve the bioavailability of the pollutant to degradative microorganisms using electrokinetics, by moving the chemical and microbes relative to each others. (orig.)

  5. The synthesis of some unsaturated 4-substituted-g-lactones

    Directory of Open Access Journals (Sweden)

    SUREN HUSINEC

    2000-02-01

    Full Text Available The synthesis of conjugated and nonconjugated unsaturated 4-substituted lactones of type 1 and 2 are described. The type 1 lactone was prepared by a two step procedure employing Bredereck's reagent. The type 2 lactone was synthesised by combining the Claisen-Ireland rearrangement and selenolactonisation.

  6. Uncertainty analyses of unsaturated zone travel time at Yucca Mountain

    International Nuclear Information System (INIS)

    Nichols, W.E.; Freshley, M.D.

    1993-01-01

    Uncertainty analysis method can be applied to numerical models of ground-water flow to estimate the relative importance of physical and hydrologic input variables with respect to ground-water travel time. Monte Carlo numerical simulations of unsaturated flow in the Calico Hills nonwelded zeolitic (CHnz) layer at Yucca Mountain, Nevada, indicate that variability in recharge, and to a lesser extent in matrix porosity, explains most of the variability in predictions of water travel time through the unsaturated zone. Variations in saturated hydraulic conductivity and unsaturated curve-fitting parameters were not statistically significant in explaining variability in water travel time through the unsaturated CHnz unit. The results of this study suggest that the large uncertainty associated with recharge rate estimates for the Yucca Mountain site is of concern because the performance of the potential repository would be more sensitive to uncertainty in recharge than to any other parameter evaluated. These results are not exhaustive because of the limited site characterization data available and because of the preliminary nature of this study, which is limited to a single stratigraphic unit, one dimension, and does not account for fracture flow or other potential fast pathways at Yucca Mountain

  7. Adsorbents for radioactive organic solvent wastes

    International Nuclear Information System (INIS)

    Ichinose, Shigeo; Kiribayashi, Takehiko.

    1986-01-01

    Purpose: To enable to settle radioactive solvents such as tributyl phosphate (TBP) and n-dodecane as they are without using hydrophobicizing agent such as quaternary ammonium salts. Constitution: The adsorbents are prepared by replacing interlaminer ions of swelling-type synthetic mica with alkaline earth metals or metal ions. For instance, synthetic micas introduced with Zr 4+ or Ca 2+ between the layers provide quite different functions from those of starting materials due to the properties of ions introduced between the layers. That is, they provide an intense affinity to organic phosphates such as TBP and transform into material showing a property of adsorbing and absorbing them. Particularly, the fixing nature to the phosphor content constituting TBP is significantly increased. (Horiuchi, T.)

  8. Zeolites as alcohol adsorbents from aqueous solutions

    Directory of Open Access Journals (Sweden)

    Cekova Blagica

    2006-01-01

    Full Text Available The potential usage of zeolites as adsorbents for the removal of organic molecules from water was investigated in a series of experiments with aqueous solutions of lower alcohols. This could represent a simple solution to the problem of cleaning up industrial wastewater as well as recovering valuable chemicals at relatively low costs. Adsorption isotherms of the Langmuir type were applied, and calculations showed that the amount of propanol adsorbed on silicalite corresponded to approximately 70% of the pore volume. The adsorption process is simple, and recovery of the more concentrated products is easily done by heat treatment and/or at lowered pressures. Adsorption experiments with aqueous acetone showed that silicalite had approximately the same adsorption capacity for acetone as for n-propanol. Heats of adsorption were determined calorimetrically.

  9. Analysis of Adsorbed Natural Gas Tank Technology

    Science.gov (United States)

    Knight, Ernest; Schultz, Conrad; Rash, Tyler; Dohnke, Elmar; Stalla, David; Gillespie, Andrew; Sweany, Mark; Seydel, Florian; Pfeifer, Peter

    With gasoline being an ever decreasing finite resource and with the desire to reduce humanity's carbon footprint, there has been an increasing focus on innovation of alternative fuel sources. Natural gas burns cleaner, is more abundant, and conforms to modern engines. However, storing compressed natural gas (CNG) requires large, heavy gas cylinders, which limits space and fuel efficiency. Adsorbed natural gas (ANG) technology allows for much greater fuel storage capacity and the ability to store the gas at a much lower pressure. Thus, ANG tanks are much more flexible in terms of their size, shape, and weight. Our ANG tank employs monolithic nanoporous activated carbon as its adsorbent material. Several different configurations of this Flat Panel Tank Assembly (FPTA) along with a Fuel Extraction System (FES) were examined to compare with the mass flow rate demands of an engine.

  10. 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.

  11. Green Adsorbents for Wastewaters: A Critical Review

    Directory of Open Access Journals (Sweden)

    George Z. Kyzas

    2014-01-01

    Full Text Available One of the most serious environmental problems is the existence of hazardous and toxic pollutants in industrial wastewaters. The major hindrance is the simultaneous existence of many/different types of pollutants as (i dyes; (ii heavy metals; (iii phenols; (iv pesticides and (v pharmaceuticals. Adsorption is considered to be one of the most promising techniques for wastewater treatment over the last decades. The economic crisis of the 2000s led researchers to turn their interest in adsorbent materials with lower cost. In this review article, a new term will be introduced, which is called “green adsorption”. Under this term, it is meant the low-cost materials originated from: (i agricultural sources and by-products (fruits, vegetables, foods; (ii agricultural residues and wastes; (iii low-cost sources from which most complex adsorbents will be produced (i.e., activated carbons after pyrolysis of agricultural sources. These “green adsorbents” are expected to be inferior (regarding their adsorption capacity to the super-adsorbents of previous literature (complex materials as modified chitosans, activated carbons, structurally-complex inorganic composite materials etc., but their cost-potential makes them competitive. This review is a critical approach to green adsorption, discussing many different (maybe in some occasions doubtful topics such as: (i adsorption capacity; (ii kinetic modeling (given the ultimate target to scale up the batch experimental data to fixed-bed column calculations for designing/optimizing commercial processes and (iii critical techno-economical data of green adsorption processes in order to scale-up experiments (from lab to industry with economic analysis and perspectives of the use of green adsorbents.

  12. Generating Atomistic Slab Surfaces with Adsorbates

    Science.gov (United States)

    2017-12-01

    slabs of various thickness and with various vacuum spacing need be calculated. This can occur in serial or simultaneously . If performed in serial, the...the user. Although the optimization of the slab thickness and vacuum padding can be done simultaneously , it is more computationally conservative to...monolayer is a slab (True if slab), the type of mesh desired (adsorbates.py was written for “Gamma”), how detailed the mesh should be (in units of inverse

  13. Green Adsorbents for Wastewaters: A Critical Review

    Science.gov (United States)

    Kyzas, George Z.; Kostoglou, Margaritis

    2014-01-01

    One of the most serious environmental problems is the existence of hazardous and toxic pollutants in industrial wastewaters. The major hindrance is the simultaneous existence of many/different types of pollutants as (i) dyes; (ii) heavy metals; (iii) phenols; (iv) pesticides and (v) pharmaceuticals. Adsorption is considered to be one of the most promising techniques for wastewater treatment over the last decades. The economic crisis of the 2000s led researchers to turn their interest in adsorbent materials with lower cost. In this review article, a new term will be introduced, which is called “green adsorption”. Under this term, it is meant the low-cost materials originated from: (i) agricultural sources and by-products (fruits, vegetables, foods); (ii) agricultural residues and wastes; (iii) low-cost sources from which most complex adsorbents will be produced (i.e., activated carbons after pyrolysis of agricultural sources). These “green adsorbents” are expected to be inferior (regarding their adsorption capacity) to the super-adsorbents of previous literature (complex materials as modified chitosans, activated carbons, structurally-complex inorganic composite materials etc.), but their cost-potential makes them competitive. This review is a critical approach to green adsorption, discussing many different (maybe in some occasions doubtful) topics such as: (i) adsorption capacity; (ii) kinetic modeling (given the ultimate target to scale up the batch experimental data to fixed-bed column calculations for designing/optimizing commercial processes) and (iii) critical techno-economical data of green adsorption processes in order to scale-up experiments (from lab to industry) with economic analysis and perspectives of the use of green adsorbents. PMID:28788460

  14. Adsorbate Diffusion on Transition Metal Nanoparticles

    Science.gov (United States)

    2015-01-01

    correlation is a Bronsted-Evans-Polanyi ( BEP )- type of correlation, similar to other BEP correlations established earlier for surface-catalyzed bond- breaking...bond-making reactions.6-9 The universal BEP -type correlation is independent of the nature of the adsorbed species and that of the metal surface. For...a certain class of surface-catalyzed reactions, the existence of a BEP -type correlation reflects a similarity between the geometry of the transition

  15. Theoretical Insight of Physical Adsorption for a Single-Component Adsorbent + Adsorbate System: I. Thermodynamic Property Surfaces

    KAUST Repository

    Chakraborty, Anutosh; Saha, Bidyut Baran; Ng, Kim Choon; Koyama, Shigeru; Srinivasan, Kandadai

    2009-01-01

    Thermodynamic property surfaces for a single-component adsorbent + adsorbate system are derived and developed from the viewpoint of classical thermodynamics, thermodynamic requirements of chemical equilibrium, Gibbs law, and Maxwell relations

  16. 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.

  17. Biological adsorbent for water decontamination from uranium

    Energy Technology Data Exchange (ETDEWEB)

    Jilek, R [Vyzkumny Ustav Veterinarniho Lekarstvi, Brno-Medlanky (Czechoslovakia); Fuska, J; Nemec, P [Slovenska Vysoka Skola Technicka, Bratislava (Czechoslovakia). Chemickotechnologicka Fakulta

    1978-01-01

    A study was made into the capacity of native and heat-denaturated mycelium to adsorb uranium salts from solutions and into the effect of uranium on the growth of the microorganism biomass. The presence of uranium did not inhibit the growth of Penicillium and Aspergillus strains used at a concentration of up to 5x10/sup -4/ M/dm/sup 3/. Uranium added to a nutrient medium produced complexes with phosphorus ions which were adsorbed on the surface of growing hyphae, thus the removal of the mycelium also removed uranium. The results of the experiments with denaturated mycelium of the same strains suggested that uranium was also bound to the biomass with chemical bonds so that mycelium acted as a ''multifunction ion exchanger'' from which adsorbed uranium can be removed step by step by elution. A sorbent of a three-dimensional structure could be prepared from a dried native mycelium using reinforcing resins, which prevented leakage of the biomass. Uranium sorption by biosorbents is a function of the concentration of the cation sorbed and of the pH of the solution.

  18. Biological adsorbent for water decontamination from uranium

    International Nuclear Information System (INIS)

    Jilek, R.; Fuska, J.; Nemec, P.

    1978-01-01

    A study was made into the capacity of native and heat-denaturated mycelium to adsorb uranium salts from solutions and into the effect of uranium on the growth of the microorganism biomass. The presence of uranium did not inhibit the growth of Penicillium and Aspergillus strains used at a concentration of up to 5x10 -4 M/dm 3 . Uranium added to a nutrient medium produced complexes with phosphorus ions which were adsorbed on the surface of growing hyphae, thus the removal of the mycelium also removed uranium. The results of the experiments with denaturated mycelium of the same strains suggested that uranium was also bound to the biomass with chemical bonds so that mycelium acted as a ''multifunction ion exchanger'' from which adsorbed uranium can be removed step by step by elution. A sorbent of a three-dimensional structure could be prepared from a dried native mycelium using reinforcing resins, which prevented leakage of the biomass. Uranium sorption by biosorbents is a function of the concentration of the cation sorbed and of the pH of the solution. (author)

  19. Characterisation of lignite as an industrial adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Ying Qi; Andrew F.A. Hoadley; Alan L. Chaffee; Gil Garnier [Monash University, Clayton, Vic. (Australia). Department of Chemical Engineering

    2011-04-15

    An alternative use of the abundant and inexpensive lignite (also known as brown coal) as an industrial adsorbent has been characterised. The adsorptive properties of two Victorian lignite without any pre-treatment were investigated using the cationic methylene blue dye as a model compound in aqueous solutions. Two commercial activated carbon products were also studied for comparison. The adsorption equilibrium of the four adsorbents was better described by the Langmuir isotherm model than the Freundlich model. The adsorption capacities of the two untreated lignite adsorbents, Loy Yang and Yallourn, calculated using Langmuir isotherms were 286 and 370 mg/g, respectively, higher than a coconut shell-based activated carbon (167 mg/g), but lower than a coal-based activated carbon (435 mg/g). Surface area results suggested that larger micropores and mesopores were important for achieving good methylene blue adsorption by the activated carbons. However, FTIR and cation exchange capacity analyses revealed that, for the lignite, chemical interactions between lignite surface functional groups and methylene blue molecules occurred, thereby augmenting its adsorption capacity. 63 refs., 3 figs., 7 tabs.

  20. Transport of citrate-coated silver nanoparticles in unsaturated sand

    Energy Technology Data Exchange (ETDEWEB)

    Kumahor, Samuel K., E-mail: samuel.kumahor@ufz.de [Department of Soil Physics, Helmholtz Centre for Environmental Research–UFZ, Theodor-Lieser-Strasse 4, 06120 Halle-Saale (Germany); Hron, Pavel, E-mail: pavel.hron@iwr.uni-heidelberg.de [Interdisciplinary Center for Scientific Computing, University of Heidelberg, Im Neuenheimer Feld 368, Raum 422, 69120 Heidelberg (Germany); Metreveli, George, E-mail: metreveli@uni-landau.de [Universität Koblenz-Landau, Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, Fortstr. 7, D-76829 Landau (Germany); Schaumann, Gabriele E., E-mail: schaumann@uni-landau.de [Universität Koblenz-Landau, Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, Fortstr. 7, D-76829 Landau (Germany); Vogel, Hans-Jörg, E-mail: hans-joerg.vogel@ufz.de [Department of Soil Physics, Helmholtz Centre for Environmental Research–UFZ, Theodor-Lieser-Strasse 4, 06120 Halle-Saale (Germany); Institute of Soil Science and Plant Nutrition, Martin-Luther-University Halle-Wittenberg, Von-Seckendorff-Platz 3, 06120 Halle-Saale (Germany)

    2015-12-01

    Chemical factors and physical constraints lead to coupled effects during particle transport in unsaturated porous media. Studies on unsaturated transport as typical for soils are currently scarce. In unsaturated porous media, particle mobility is determined by the existence of an air–water interface in addition to a solid–water interface. To this end, we measured breakthrough curves and retention profiles of citrate-coated Ag nanoparticles in unsaturated sand at two pH values (5 and 9) and three different flow rates corresponding to different water contents with 1 mM KNO{sub 3} as background electrolyte. The classical DLVO theory suggests unfavorable deposition conditions at the air–water and solid–water interfaces. The breakthrough curves indicate modification in curve shapes and retardation of nanoparticles compared to inert solute. Retention profiles show sensitivity to flow rate and pH and this ranged from almost no retention for the highest flow rate at pH = 9 to almost complete retention for the lowest flow rate at pH = 5. Modeling of the breakthrough curves, thus, required coupling two parallel processes: a kinetically controlled attachment process far from equilibrium, responsible for the shape modification, and an equilibrium sorption, responsible for particle retardation. The non-equilibrium process and equilibrium sorption are suggested to relate to the solid–water and air–water interfaces, respectively. This is supported by the DLVO model extended for hydrophobic interactions which suggests reversible attachment, characterized by a secondary minimum (depth 3–5 kT) and a repulsive barrier at the air–water interface. In contrast, the solid–water interface is characterized by a significant repulsive barrier and the absence of a secondary minimum suggesting kinetically controlled and non-equilibrium interaction. This study provides new insights into particle transport in unsaturated porous media and offers a model concept representing the

  1. Transport of citrate-coated silver nanoparticles in unsaturated sand

    Science.gov (United States)

    Kumahor, Samuel; Hron, Pavel; Metreveli, George; Schaumann, Gabriele; Vogel, Hans-Jörg

    2015-04-01

    Chemical factors and physical constraints lead to coupled effects during particle transport in unsaturated porous media. Unlike for saturated transport, studies on unsaturated transport as typical for soil are currently scarce. We investigated the mobility of citrate-coated Ag NPs in unsaturated sand (grain diameter: 0.1-0.3 mm). For three flux rates and a given pore-water ionic strength (1 mM KNO3), the citrate-coated Ag NPs were less mobile at pH = 5 compared to pH = 9. The classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory suggests unfavorable deposition conditions at both, the air-water interface and solid-water interface. Breakthrough curves measured under quasi-steady state unsaturated flow showed retardation of the citrate-coated Ag NPs compared to inert solute (KBr). After flushing with nanoparticle-free 1 mM KNO3 solution (pH-adjusted), retention was much lower in deeper depths compared to the surface where the particles entered the flow field. The results show a non-linear dependence of nanoparticle (NP) mobility on flux rate and water content. Especially the observed retardation similar to equilibrium sorption is in contrast to observations under saturated flow conditions. A convection-dispersion and reaction model that combines a reversible equilibrium process and a non-equilibrium interaction process reproduced the measured breakthrough curves reasonably well. From comparison between saturated and unsaturated experiments we conclude that the air-water interface is responsible for the reversible equilibrium process while the water-solid interface accounts for irreversible soption.

  2. Groundwater recharge dynamics in unsaturated fractured chalk: a case study

    Science.gov (United States)

    Cherubini, Claudia; Pastore, Nicola; Giasi, Concetta I.; Allegretti, Nicolaetta M.

    2016-04-01

    The heterogeneity of the unsaturated zone controls its hydraulic response to rainfall and the extent to which pollutants are delayed or attenuated before reaching groundwater. It plays therefore a very important role in the recharge of aquifers and the transfer of pollutants because of the presence of temporary storage zones and preferential flows. A better knowledge of the physical processes in the unsaturated zone would allow an improved assessment of the natural recharge in a heterogeneous aquifer and of its vulnerability to surface-applied pollution. The case study regards the role of the thick unsaturated zone of the Cretaceous chalk aquifer in Picardy (North of France) that controls the hydraulic response to rainfall. In the North Paris Basin, much of the recharge must pass through a regional chalk bed that is composed of a porous matrix with embedded fractures. Different types of conceptual models have been formulated to explain infiltration and recharge processes in the unsaturated fractured rock. The present study analyses the episodic recharge in fractured Chalk aquifer using the kinematic diffusion theory to predict water table fluctuation in response to rainfall. From an analysis of the data, there is the evidence of 1) a seasonal behavior characterized by a constant increase in the water level during the winter/spring period and a recession period, 2) a series of episodic behaviors during the summer/autumn. Kinematic diffusion models are useful for predict preferential fluxes and dynamic conditions. The presented approach conceptualizes the unsaturated flow as a combination of 1) diffusive flow refers to the idealized portion of the pore space of the medium within the flow rate is driven essentially by local gradient of potential; 2) preferential flow by which water moves across macroscopic distances through conduits of macropore length.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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)

  8. 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.

  9. 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.

  10. 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.

  11. 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)

  12. 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...

  13. 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....

  14. 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.

  15. 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...

  16. 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.

  17. 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

  18. The adsorber loop concept for the contact between seawater and adsorber granulate

    International Nuclear Information System (INIS)

    Koske, P.H.; Ohlrogge, K.

    1984-01-01

    For the production of 1 kg uranium from seawater about 10 9 kg seawater - depending on the extraction efficiency - have to be processed in a production plant. Such high seawater flows have to be put through adsorber beds the area of which depends on the flow velocity of the water in the bed. For a typical polyamidoxim (PAO) adsorber granulate with a grain size distribution of 0.3 to 1.2 mm the velocity in a fluidized bed is limited to about 1 cm/s in order to prevent carry out of the adsorber material. The consequences of this rather low bed velocity are large and expensive bed areas for technical production plants. The present paper deals with the so-called ''adsorber loop concept'' in which the adsorber granulate is carried along with the seawater to be processed in a loop-like configuration and is separated again from the water before this is leaving the adsorption unit. This concept enables considerably higher seawater velocities thus reducing the bed area. Theoretical considerations are presented together with experimental results from field tests. (author)

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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)

  5. Removal of adsorbent particles od copper ions by Jet flotation

    International Nuclear Information System (INIS)

    Santander, M.; Tapia, P.; Pavez, O.; Valderrama, L.; Guzman, D.

    2009-01-01

    The present study shows the results obtained on the removal of copper ions from synthetic effluents by using the adsorbent particles flotation technique (APF) in a Jet flotation cell (Jameson type). In a typical experimental run, a mineral with high quartz content was used as adsorbent particles in the adsorption and flotation experiments, to determine optimal pH conditions, adsorbent particles concentration; flotation reagents dosage and air/effluent flow ratio for applying in the Jet cell to maximize the efficiency of copper ions adsorptions and the removal of particles adsorbents containing the absorbed copper ions. The results indicate the at pH>7 and at adsorbent particles concentration of 2 kg.m - 3, 99% of copper ions is adsorbed and, when the air/effluent flow ratio applied in the Jet cell is 0,2, 98% of absorbent particles containing the adsorbed copper ions is removed. (Author) 39 refs.

  6. 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

  7. Investigating Unsaturated Zone Travel Times with Tritium and Stable Isotopes

    Science.gov (United States)

    Visser, A.; Thaw, M.; Van der Velde, Y.

    2017-12-01

    Travel times in the unsaturated zone are notoriously difficult to assess. Travel time tracers relying on the conservative transport of dissolved (noble) gases (tritium-helium, CFCs or SF6) are not applicable. Large water volume requirements of other cosmogenic radioactive isotopes (sulfur-35, sodium-22) preclude application in the unsaturated zone. Prior investigations have relied on models, introduced tracers, profiles of stable isotopes or tritium, or a combination of these techniques. Significant unsaturated zone travel times (UZTT) complicate the interpretation of stream water travel time tracers by ranked StorAge Selection (rSAS) functions. Close examination of rSAS functions in a sloping soil lysimeter[1] show the effect of the UZTT on the shape of the rSAS cumulative distribution function. We studied the UZTT at the Southern Sierra Critical Zone Observatory (SS-CZO) using profiles of tritium and stable isotopes (18O and 2H) in the unsaturated zone, supported by soil water content data. Tritium analyses require 100-500 mL of soil water and therefore large soil samples (1-5L), and elaborate laboratory procedures (oven drying, degassing and noble gas mass spectrometry). The high seasonal and interannual variability in precipitation of the Mediterranean climate, variable snow pack and high annual ET/P ratios lead to a dynamic hydrology in the deep unsaturated soils and regolith and highly variable travel time distributions. Variability of the tritium concentration in precipitation further complicates direct age estimates. Observed tritium profiles (>3 m deep) are interpreted in terms of advective and dispersive vertical transport of the input variability and radioactive decay of tritium. Significant unsaturated zone travel times corroborate previously observed low activities of short-lived cosmogenic radioactive nuclides in stream water. Under these conditions, incorporating the UZTT is critical to adequately reconstruct stream water travel time distributions. 1

  8. 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.)

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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%.

  14. Changes of the water isotopic composition in unsaturated soils

    International Nuclear Information System (INIS)

    Feurdean, Victor; Feurdean, Lucia

    2001-01-01

    Based on the spatial and temporal variations of the stable isotope content in precipitation - as input in subsurface - and the mixing processes, the deuterium content in the water that moves in unsaturated zones was used to determine the most conducive season to recharge, the mechanisms for infiltration of snow or rain precipitation in humid, semi-arid or arid conditions, the episodic cycles of infiltration water mixing with the already present soil water and water vapor and whether infiltration water is or is not from local precipitation. Oscillations in the isotopic profiles of soil moisture can be used to estimate the following aspects: where piston or diffusive flow is the dominant mechanisms of water infiltration; the average velocities of the water movement in vadose zone; the influence of vegetation cover, soil type and slope exposure on the dynamics of water movement in soil; the conditions required for infiltration such as: the matrix, gravity, pressure and osmotic potentials during drainage in unsaturated soil. (authors)

  15. Simulation of groundwater flows in unsaturated porous media

    International Nuclear Information System (INIS)

    Musy, A.

    1976-01-01

    Groundwater flow in unsaturated porous media is caused by a potential gradient where the total potential consists of the sum of a gravitational and a suction component. The partial differential equations which result from the general analysis of groundwater flow in unsaturated soil are solved by succesive approximations with the finite-element method. General boundary and initial conditions, linear or curvilinear shaped elements (isoparametric elements) and steady-state or transient flow can be introduced into the numerical computer program. The results of this mathematical model are compared with experimental data established in the laboratory with a physical groundwater model. This is a rectangular testing tank of dimension 3 x 1.5 x 0.15 m and contains a silty clay loam. The variation of the bulk density and the volumetric moisture of the soil as a function of time and space are measured by gamma absorption from a 137 Cs source with 300 mCi intensity

  16. Thermal conductivity measurements in unsaturated hydrate-bearing sediments

    Science.gov (United States)

    Dai, Sheng; Cha, Jong-Ho; Rosenbaum, Eilis J.; Zhang, Wu; Seol, Yongkoo

    2015-08-01

    Current database on the thermal properties of hydrate-bearing sediments remains limited and has not been able to capture their consequential changes during gas production where vigorous phase changes occur in this unsaturated system. This study uses the transient plane source (TPS) technique to measure the thermal conductivity of methane hydrate-bearing sediments with various hydrate/water/gas saturations. We propose a simplified method to obtain thermal properties from single-sided TPS signatures. Results reveal that both volume fraction and distribution of the pore constituents govern the thermal conductivity of unsaturated specimens. Thermal conductivity hysteresis is observed due to water redistribution and fabric change caused by hydrate formation and dissociation. Measured thermal conductivity increases evidently when hydrate saturation Sh > 30-40%, shifting upward from the geometric mean model prediction to a Pythagorean mixing model. These observations envisage a significant drop in sediment thermal conductivity when residual hydrate/water saturation falls below ~40%, hindering further gas production.

  17. Electrokinetic remediation of anionic contamination from unsaturated soil: Field application

    International Nuclear Information System (INIS)

    Lindgren, E.R.; Mattson, E.D.

    1995-01-01

    Electrokinetic remediation is an in situ technique under development at Sandia National Laboratories for removal of ionic contaminants from soil. While to date most other studies of this technique have focused on saturated soils, usually clays, the work at Sandia has been to extend the process to unsaturated sandy soils typical of arid regions. The impetus for this study is a chromate plume located beneath an old Sandia chemical waste landfill. Working in unsaturated soils is complicated by moisture control requirements, both to prevent undesired hydraulic transport of contamination outside the treatment zone and to optimize soil properties for efficient electrokinetic remediation. Two field tests will be discussed. First, a field test in clean soil is in progress to demonstrate moisture control with the Sandia electrode system. The second field demonstration, planned to begin the Fall of 1995, involves chromate removal from a in a chemical waste landfill

  18. AN ACTIVE FRACTURE MODEL FOR UNSATURATED FLOW AND TRANSPORT

    International Nuclear Information System (INIS)

    HUI-HAI LIU, GUDMUNDUR S. BODVARSSON AND CHRISTINE DOUGHTY

    1999-01-01

    Fracture/matrix (F/M) interaction is a key factor affecting flow and transport in unsaturated fractured rocks. In classic continuum approaches (Warren and Root, 1963), it is assumed that flow occurs through all the connected fractures and is uniformly distributed over the entire fracture area, which generally gives a relatively large F/M interaction. However, fractures seem to have limited interaction with the surrounding matrix at Yucca Mountain, Nevada, as suggested by geochemical nonequilibrium between the perched water (resulting mainly from fracture flow) and pore water in the rock matrix. Because of the importance of the F/M interaction and related issues, there is a critical need to develop new approaches to accurately consider the interaction reduction inferred from field data at the Yucca Mountain site. Motivated by this consideration, they have developed an active fracture model based on the hypothesis that not all connected fractures actively conduct water in unsaturated fractured rocks

  19. CAPILLARY BARRIERS IN UNSATURATED FRACTURED ROCKS OF YUCCA MOUNTAIN, NEVADA

    International Nuclear Information System (INIS)

    Wu, Y.S.; Zhang, W.; Pan, L.; Hinds, J.; Bodvarsson, G.

    2000-01-01

    This work presents modeling studies investigating the effects of capillary barriers on fluid-flow and tracer-transport processes in the unsaturated zone of Yucca Mountain, Nevada, a potential site for storing high-level radioactive waste. These studies are designed to identify factors controlling the formation of capillary barriers and to estimate their effects on the extent of possible large-scale lateral flow in unsaturated fracture rocks. The modeling approach is based on a continuum formulation of coupled multiphase fluid and tracer transport through fractured porous rock. Flow processes in fractured porous rock are described using a dual-continuum concept. In addition, approximate analytical solutions are developed and used for assessing capillary-barrier effects in fractured rocks. This study indicates that under the current hydrogeologic conceptualization of Yucca Mountain, strong capillary-barrier effects exist for significantly diverting moisture flow

  20. A novel collector 2-ethyl-2-hexenoic hydroxamic acid: Flotation performance and adsorption mechanism to ilmenite

    International Nuclear Information System (INIS)

    Xu, Haifeng; Zhong, Hong; Tang, Qing; Wang, Shuai; Zhao, Gang; Liu, Guangyi

    2015-01-01

    Graphical abstract: EHHA's synthesis route, flotation performance and coadsorption molecule–ion mechanism to ilmenite. - Highlights: • 2-Ethyl-2-hexenoic hydroxamic acid (EHHA) was synthesized and characterized. • EHHA showed stronger affinity to ilmenite. • EHHA might chemisorb onto ilmenite surfaces by form of five-membered chelates. • EHHA might adsorb onto ilmenite surfaces through molecule–ion coadsorption model. - Abstract: In this paper, a novel collector, 2-ethyl-2-hexenoic hydroxamic acid (EHHA) was prepared and characterized by elemental analysis, infrared, "1H NMR, "1"3C NMR and mass spectra. The flotation performance and adsorption mechanism of EHHA to ilmenite were investigated by micro-flotation tests, density functional theory (DFT) calculations, FTIR spectra, zeta potential and solution chemistry analyses. The micro-flotation results indicated that EHHA exhibited superior flotation performance compared to isooctyl hydroximic acid (IOHA) and octyl hydroxamic acid (OHA), and floated out 84.03% ilmenite at pH 8.0 with 250 mg/L dosage. The analyses of FTIR spectra and zeta potential demonstrated that EHHA might chemisorb onto ilmenite surfaces by form of five-membered chelates. The solution chemistry analyses further inferred that at pH 6.3–10.5, both Fe and Ti species on ilmenite surfaces could chelate EHHA. DFT calculation results implied EHHA owned the strongest affinity to ilmenite among the three C_8 hydroximic acids. To discern the sharply improving floatability of ilmenite at pH 8–10, a schematic co-adsorption molecule–ion model of EHHA on ilmenite surfaces was suggested.

  1. Volatile organic compounds in the unsaturated zone from radioactive wastes

    Science.gov (United States)

    Baker, Ronald J.; Andraski, Brian J.; Stonestrom, David A.; Luo, Wentai

    2012-01-01

    Volatile organic compounds (VOCs) are often comingled with low-level radioactive wastes (LLRW), but little is known about subsurface VOC emanations from LLRW landfills. The current study systematically quantified VOCs associated with LLRW over an 11-yr period at the USGS Amargosa Desert Research Site (ADRS) in southwestern Nevada. Unsaturated-zone gas samples of VOCs were collected by adsorption on resin cartridges and analyzed by thermal desorption and GC/MS. Sixty of 87 VOC method analytes were detected in the 110-m-thick unsaturated zone surrounding a LLRW disposal facility. Chlorofluorocarbons (CFCs) were detected in 100% of samples collected. Chlorofluorocarbons are powerful greenhouse gases, deplete stratospheric ozone, and are likely released from LLRW facilities worldwide. Soil-gas samples collected from a depth of 24 m and a horizontal distance 100 m south of the nearest waste-disposal trench contained >60,000 ppbv total VOCs, including >37,000 ppbv CFCs. Extensive sampling in the shallow unsaturated zone (0–2 m deep) identified areas where total VOC concentrations exceeded 5000 ppbv at the 1.5-m depth. Volatile organic compound concentrations exceeded background levels up to 300 m from the facility. Maximum vertical diffusive fluxes of total VOCs were estimated to be 1 g m-2 yr-1. Volatile organic compound distributions were similar but not identical to those previously determined for tritium and elemental mercury. To our knowledge, this study is the first to characterize the unsaturated zone distribution of VOCs emanating from a LLRW landfill. Our results may help explain anomalous transport of radionuclides at the ADRS and elsewhere.

  2. Stereoselective synthesis of unsaturated α-amino acids.

    Science.gov (United States)

    Fanelli, Roberto; Jeanne-Julien, Louis; René, Adeline; Martinez, Jean; Cavelier, Florine

    2015-06-01

    Stereoselective synthesis of unsaturated α-amino acids was performed by asymmetric alkylation. Two methods were investigated and their enantiomeric excess measured and compared. The first route consisted of an enantioselective approach induced by the Corey-Lygo catalyst under chiral phase transfer conditions while the second one involved the hydroxypinanone chiral auxiliary, both implicating Schiff bases as substrate. In all cases, the use of a prochiral Schiff base gave higher enantiomeric excess and yield in the final desired amino acid.

  3. Hydrogeology of the unsaturated zone, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Montazer, P.; Wilson, W.E.

    1985-01-01

    The unsaturated volcanic tuff beneath Yucca Mountain, Nevada, is being evaluated by the US Department of Energy as a host rock for a potential mined geologic repository for high-level radioactive waste. Assessment of site suitability needs an efficient and focused investigative program. A conceptual hydrogeologic model that simulates the flow of fluids through the unsaturated zone at Yucca Mountain was developed to guide the program and to provide a basis for preliminary assessment of site suitability. The study was made as part of the Nevada Nuclear Waste Storage Investigations Project of the US Department of Energy. Thickness of the unsaturated zone is about 1640 to 2460 feet (500 to 750 meters). Based on physical properties, the rocks in the unsaturated zone are grouped for the purpose of this paper into five informal hydrogeologic units. From top to bottom these units are: Tiva Canyon welded unit, Paintbrush nonwelded unit. Topopah Spring welded unit, Calico Hills nonwelded unit, and Crater Flat unit. Welded units have a mean fracture density of 8 to 40 fractures per unit cubic meter, mean matrix porosities of 12 to 23%, matrix hydraulic conductivities with geometric means ranging from 6.5 x 10 -6 to 9.8 x 10 -6 foot per day (2 x 10 -6 to 3 x 10 -6 meter per day), and bulk hydraulic conductivities of 0.33 to 33 feet per day (0.1 to 10 meters per day). The nonwelded units have a mean fracture density of 1 to 3 fractures per unit cubic meter, mean matrix porosities of 31 to 46%, and saturated hydraulic conductivities with geometric means ranging from 2.6 x 10 -5 to 2.9 x 10 -2 foot per day (8 x 10 -6 to 9 x 10 -3 meter per day). 15 refs., 4 figs., 1 tab

  4. The transport and behaviour of isoproturon in unsaturated chalk cores

    Science.gov (United States)

    Besien, T. J.; Williams, R. J.; Johnson, A. C.

    2000-04-01

    A batch sorption study, a microcosm degradation study, and two separate column leaching studies were used to investigate the transport and fate of isoproturon in unsaturated chalk. The column leaching studies used undisturbed core material obtained from the field by dry percussion drilling. Each column leaching study used 25 cm long, 10 cm wide unsaturated chalk cores through which a pulse of isoproturon and bromide was eluted. The cores were set-up to simulate conditions in the unsaturated zone of the UK Chalk aquifer by applying a suction of 1 kPa (0.1 m H 2O) to the base of each column, and eluting at a rate corresponding to an average recharge rate through the unsaturated Chalk. A dye tracer indicated that the flow was through the matrix under these conditions. The results from the first column study showed high recovery rates for both isoproturon (73-92%) and bromide (93-96%), and that isoproturon was retarded by a factor of about 1.23 relative to bromide. In the second column study, two of the four columns were eluted with non-sterile groundwater in place of the sterile groundwater used on all other columns, and this study showed high recovery rates for bromide (85-92%) and lower recovery rates for isoproturon (66-79% — sterile groundwater, 48-61% — non-sterile groundwater). The enhanced degradation in the columns eluted with non-sterile groundwater indicated that groundwater microorganisms had increased the degradation rate within these columns. Overall, the reduced isoproturon recovery in the second column study was attributed to increased microbial degradation as a result of the longer study duration (162 vs. 105 days). The breakthrough curves (BTCs) for bromide had a characteristic convection-dispersion shape and were accurately simulated with the minimum of calibration using a simple convection-dispersion model (LEACHP). However, the isoproturon BTCs had an unusual shape and could not be accurately simulated.

  5. Uranium Sequestration by Aluminum Phosphate Minerals in Unsaturated Soils

    International Nuclear Information System (INIS)

    Jerden, James L. Jr.

    2007-01-01

    A mineralogical and geochemical study of soils developed from the unmined Coles Hill uranium deposit (Virginia) was undertaken to determine how phosphorous influences the speciation of uranium in an oxidizing soil/saprolite system typical of the eastern United States. This paper presents mineralogical and geochemical results that identify and quantify the processes by which uranium has been sequestered in these soils. It was found that uranium is not leached from the saturated soil zone (saprolites) overlying the deposit due to the formation of a sparingly soluble uranyl phosphate mineral of the meta-autunite group. The concentration of uranium in the saprolites is approximately 1000 mg uranium per kg of saprolite. It was also found that a significant amount of uranium was retained in the unsaturated soil zone overlying uranium-rich saprolites. The uranium concentration in the unsaturated soils is approximately 200 mg uranium per kg of soil (20 times higher than uranium concentrations in similar soils adjacent to the deposit). Mineralogical evidence indicates that uranium in this zone is sequestered by a barium-strontium-calcium aluminum phosphate mineral of the crandallite group (gorceixite). This mineral is intimately inter-grown with iron and manganese oxides that also contain uranium. The amount of uranium associated with both the aluminum phosphates (as much as 1.4 weight percent) has been measured by electron microprobe micro-analyses and the geochemical conditions under which these minerals formed has been studied using thermodynamic reaction path modeling. The geochemical data and modeling results suggest the meta-autunite group minerals present in the saprolites overlying the deposit are unstable in the unsaturated zone soils overlying the deposit due to a decrease in soil pH (down to a pH of 4.5) at depths less than 5 meters below the surface. Mineralogical observations suggest that, once exposed to the unsaturated environment, the meta-autunite group

  6. Development of adsorbents for recovery of uranium from seawater

    International Nuclear Information System (INIS)

    Egawa, Hiroaki; Furusaki, Shintaro.

    1987-01-01

    The largest subject for putting the extraction of uranium from seawater in practical use is the development of high performance adsorbents for uranium. In this paper, the way of thinking about the development of adsorbents for extracting uranium from seawater and the recent reports on this subject are described. Next, the research on the adsorbing capacity and adsorbing rate of the adsorbents developed so far is summarized, and the way of thinking about the evaluation of adsorbent performance which is the base of the design of a system for extracting uranium from seawater is explained, taking amidoxime type adsorbent as the example. For Japan where energy resources are scant, the uranium contained in seawater, which is estimated to be about 4.2 billion t, is the most luring important element. Uranium is contained in seawater is very low concentration of 3 ppb, and exists as anion complex salt. In 1960s, the Harwell Atomic Energy Research Establishment in UK found out that titanium oxide hydrate is the most promising as the adsorbent. Also a number of organic absorbents have been developed. In order to bring adsorbents in contact with seawater, pumping, ocean current and wave force are utilized. Adsorbents are in spherical, fiber and film forms, and held as fixed beds and fluidized beds. (Kako, I.) 48 refs

  7. Unsaturated polyester resin composition curable with ionizing radiations

    International Nuclear Information System (INIS)

    Maruyama, Tsutomu; Murata, Koichiro.

    1971-01-01

    An unsaturated polyester resin composition curable with ionizing radiations and excellent in weather resistance is provided. The composition is obtained by reacting 10-12 moles of a polyhydric alcohol (e.g. ethylene glycol) with 10 moles of an acid mixture (25.45% by mole of endo-cis-bicyclo (2,2,1)-5-heptene-2-3-dicarboxylic acid (A), 20-40% of unsaturated dibasic acid and 15-55% of saturated dibasic acid) so that the acid value reaches 4-11. The composition is useful as coating, laminating and molding materials. As a coating material it is excellent in surface hardening property. The ionizing radiation used is preferably β-, α-rays or electron beams. In one example, and unsaturated polyester was prepared by reacting 3 moles of fumaric acid, 2 moles of phthalic anhydride, 3 moles of adipic acid 3, moles of (A), 10 moles of neopentyl glycol and 1 mole of trimethylolpropane. The resin was dissolved into a mixture of styrene, methyl methacrylate and butyl acrylate (50:8:42) and incorporated with titanium white. An ABS plate was coated with the enamel thus obtained and irradiated with electron beams (12 Mrad). In exposure test at 60 0 C, luster of the film was 92 before exposure and 83 after 30 months. In a comparative run in which (A) was not used, luster of the film decreased from 90 to 45 in 30 months. (Sakaichi, S.)

  8. Unsaturated Fatty Acids Supplementation Reduces Blood Lead Level in Rats

    Science.gov (United States)

    Skoczyńska, Anna; Wojakowska, Anna; Nowacki, Dorian; Bobak, Łukasz; Turczyn, Barbara; Smyk, Beata; Szuba, Andrzej; Trziszka, Tadeusz

    2015-01-01

    Some dietary factors could inhibit lead toxicity. The aim of this study was to evaluate the effect of dietary compounds rich in unsaturated fatty acids (FA) on blood lead level, lipid metabolism, and vascular reactivity in rats. Serum metallothionein and organs' lead level were evaluated with the aim of assessing the possible mechanism of unsaturated FA impact on blood lead level. For three months, male Wistar rats that were receiving drinking water with (100 ppm Pb) or without lead acetate were supplemented per os daily with virgin olive oil or linseed oil (0.2 mL/kg b.w.) or egg derived lecithin fraction: “super lecithin” (50 g/kg b.w.). Mesenteric artery was stimulated ex vivo by norepinephrine (NE) administered at six different doses. Lecithin supplementation slightly reduced pressor responses of artery to NE. Lead administered to rats attenuated the beneficial effect of unsaturated FA on lipid metabolism and vascular reactivity to adrenergic stimulation. On the other hand, the super lecithin and linseed oil that were characterized by low omega-6 to omega-3 ratio (about 1) reduced the blood lead concentration. This effect was observed in lead poisoned rats (p < 0.0001) and also in rats nonpoisoned with lead (p < 0.05). PMID:26075218

  9. Growth of Synthrophomonas wolfei on unsaturated short chain fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Amos, D.A.; McInerney, M.J. (Univ. of Oklahoma, Norman, OK (United States))

    1990-01-01

    The anaerobic fatty acid-degrading syntrophic bacterium, Syntrophomonas wolfei, was grown in pure culture with either trans-2-pentenoate, trans-2-hexenoate, trans-3-hexenoate, or trans, trans-2, 4-hexadienoate as the substrate. Trans-2-pentenoate was fermented to acetate, propionate, butyrate, and valerate. Acetate, butyrate and hexanoate were produced from the six-carbon mono- and di-unsaturated acids. Propionate was also product from the trans, trans-2, 4-hexadienoate which suggested that compound was degraded by another pathway in addition to [beta]-oxidation. The transient production of trans-2-hexenoate from trans-3-hexenoate suggested that the position of the double bound shifted from carbon-3 to carbon-2 prior to [beta]-oxidation. The specific growth rate decreased with increasing carbon length and degree of unsaturation. Molar growth yields ranged from 8.4 to 17.5 mg (dry wt.) per mmol and suggested that energy was conserved not only from substrate-level phosphorylation, but also from the reduction of unsaturated substrate.

  10. Saturated versus unsaturated hydrocarbon interactions with carbon nanostructures

    Directory of Open Access Journals (Sweden)

    Deivasigamani eUmadevi

    2014-09-01

    Full Text Available The interactions of various acyclic and cyclic hydrocarbons in both saturated and unsaturated forms with the carbon nanostructures (CNSs have been explored by using density functional theory (DFT calculations. Model systems representing armchair and zigzag carbon nanotubes (CNTs and graphene have been considered to investigate the effect of chirality and curvature of the CNSs towards these interactions. Results of this study reveal contrasting binding nature of the acyclic and cyclic hydrocarbons towards CNSs. While the saturated molecules show stronger binding affinity in acyclic hydrocarbons; the unsaturated molecules exhibit higher binding affinity in cyclic hydrocarbons. In addition, acyclic hydrocarbons exhibit stronger binding affinity towards the CNSs when compared to their corresponding cyclic counterparts. The computed results excellently corroborate the experimental observations. The interaction of hydrocarbons with graphene is more favourable when compared with CNTs. Bader’s theory of atoms in molecules has been invoked to characterize the noncovalent interactions of saturated and unsaturated hydrocarbons. Our results are expected to provide useful insights towards the development of rational strategies for designing complexes with desired noncovalent interaction involving CNSs.

  11. A quasilinear model for solute transport under unsaturated flow

    International Nuclear Information System (INIS)

    Houseworth, J.E.; Leem, J.

    2009-01-01

    We developed an analytical solution for solute transport under steady-state, two-dimensional, unsaturated flow and transport conditions for the investigation of high-level radioactive waste disposal. The two-dimensional, unsaturated flow problem is treated using the quasilinear flow method for a system with homogeneous material properties. Dispersion is modeled as isotropic and is proportional to the effective hydraulic conductivity. This leads to a quasilinear form for the transport problem in terms of a scalar potential that is analogous to the Kirchhoff potential for quasilinear flow. The solutions for both flow and transport scalar potentials take the form of Fourier series. The particular solution given here is for two sources of flow, with one source containing a dissolved solute. The solution method may easily be extended, however, for any combination of flow and solute sources under steady-state conditions. The analytical results for multidimensional solute transport problems, which previously could only be solved numerically, also offer an additional way to benchmark numerical solutions. An analytical solution for two-dimensional, steady-state solute transport under unsaturated flow conditions is presented. A specific case with two sources is solved but may be generalized to any combination of sources. The analytical results complement numerical solutions, which were previously required to solve this class of problems.

  12. Characterization of unsaturated hydraulic parameters for homogeneous and heterogeneous soils

    Energy Technology Data Exchange (ETDEWEB)

    Wildenschild, Dorthe

    1997-09-01

    Application of numerical models for predicting future spreading of contaminants into ground water aquifers is dependent on appropriate characterization of the soil hydraulic properties controlling flow and transport in the unsaturated zone. This thesis reviews the current knowledge on two aspects of characterization of unsaturated hydraulic parameters; estimation of the basic hydraulic parameters for homogeneous soils and statistical representation of heterogeneity for spatially variable soils. The retention characteristic is traditionally measured using steady-state procedures, but new ideas based on dynamic techniques have been developed that reduce experimental efforts and that produce retention curves which compare to those measured by traditional techniques. The unsaturated hydraulic conductivity is difficult to establish by steady-state procedures, and extensive research efforts have been focused on alternative methods that are based on inverse estimation. The inverse methods have commonly been associated with problems of numerical instability and ill-posedness of the parameter estimates, but recent investigations have shown that the uniqueness of parameter estimates can be improved by including additional, independent information on, for instance, the retention characteristic. Also, uniqueness may be improved by careful selection of experimental conditions are parametric functions. (au) 234 refs.

  13. Analysis of pumping-induced unsaturated regions beneath aperennial river

    Energy Technology Data Exchange (ETDEWEB)

    Su, G.W.; Jasperse, J.; Seymour, D.; Constantz, J.; Zhou, Q.

    2007-05-15

    The presence of an unsaturated region beneath a streambedduring groundwater pumping near streams reduces the pumping capacity whenit reaches the well screens, changes flow paths, and alters the types ofbiological transformations in the streambed sediments. Athree-dimensional, multi-phase flow model of two horizontal collectorwells along the Russian River near Forestville, California was developedto investigate the impact of varying the ratio of the aquifer tostreambed permeability on (1) the formation of an unsaturated regionbeneath the stream, (2) the pumping capacity, (3) stream-water fluxesthrough the streambed, and (4) stream-water travel times to the collectorwells. The aquifer to streambed permeability ratio at which theunsaturated region was initially observed ranged from 10 to 100. The sizeof the unsaturated region beneath the streambed increased as the aquiferto streambed permeability ratio increased. The simulations also indicatedthat for a particular aquifer permeability, decreasing the streambedpermeability by only a factor of 2-3 from the permeability wheredesaturation initially occurred resulted in reducing the pumpingcapacity. In some cases, the stream-water fluxes increased as thestreambed permeability decreased. However, the stream water residencetimes increased and the fraction of stream water that reached that thewells decreased as the streambed permeability decreased, indicating thata higher streambed flux does not necessarily correlate to greaterrecharge of stream water around the wells.

  14. Role of unsaturated soil in a waste containment system

    Energy Technology Data Exchange (ETDEWEB)

    Lim, P.C.; Tay, J.H. [Nanyang Technological Univ. (Singapore)

    1996-12-31

    The role of the unsaturated properties of sand as a drainage layer in a composite liner system for landfills is investigated. The effect of the unsaturated properties of coarse-grained soil on contaminant migration was evaluated by means of a series of simulations using a one-dimensional model of a two- and a three-layer soil liner system for advection and diffusion, respectively. The results showed that under seepage conditions, the effect of an unsaturated sand layer on the advancement of the concentration front was quite insignificant. The arrival time of the C/C{sub o} = 0.5 concentration front increased from 651 days for the case with no sand layer to approximately 951 days for the case with a 1.0-m sand layer. A steady-state flow condition was ultimately established in the sand, and this fact suggests that the capillary action might not be effective. For diffusion, the arrival time of the concentration front increased nonlinearly with a decrease in the degree of saturation and linearly with increasing depths of the sand layer. At a residual degree of saturation, the arrival times of the C/C{sub o} = 0.01 and 0.5 concentration front at the base of the 1-m sand layer were 26.9 and 877.4 years as compared to 1.52 and 2.62 years by advection, respectively. 17 refs., 11 figs.

  15. 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...

  16. 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...

  17. Theoretical Insight of Physical Adsorption for a Single Component Adsorbent + Adsorbate System: II. The Henry Region

    KAUST Repository

    Chakraborty, Anutosh; Saha, Bidyut Baran; Ng, Kim Choon; Koyama, Shigeru; Srinivasan, Kandadai

    2009-01-01

    evaluated and compared with experimental data. It is found that the adsorbents with higher specific surface areas tend to possess lower heat of adsorption (ΔH°) at the Henry regime. In this paper, we have established the definitive relation between Ai and ΔH

  18. Natural adsorbents of dyes from aqueous solution

    Science.gov (United States)

    Rahmani, Meryem; El Hajjaji, souad; Dahchour, Abdelmalek; El M'Rabet, Mohammadine

    2017-04-01

    Contamination of natural waters is a current environmental problem and lot of work has been done to find methods for its, prevention and remediation such as ionic exchange, adsorption on active carbon, filtration, electrolysis, biodegradation …etc. Adsorption is one of the most applied methods according to its effectiveness and easy management. Some adsorbents with good properties such as active alumina, zeolites, crop residues … etc, are suitable to substitute usual active carbon. This study aimed at the removal of dyes using oil shale as natural support, and its optimization by factorial experiment. Three factors were considered namly:pollutant concentration, pH and weight of the adsorbent. Tests have been performed with cationic and anionic dyes. Experimental results show that pseudo-first-order kinetic model provided the best fit to the experimental data for the adsorption by the oil shale. Langmuir, Freundlich and Temkin isotherm models were tested to fit experimental data, the adsorption equilibrium was well described by Freundlich isotherm for methylorange and Temkin for methyl blue. Analysis were completed by oil shale characterization educing XRD, IR, XRF techniques, and cationic exchange capacity.

  19. Optimizing heterosurface adsorbent synthesis for liquid chromatography

    Science.gov (United States)

    Bogoslovskii, S. Yu.; Serdan, A. A.

    2016-03-01

    The structural and geometric parameters of a silica matrix (SM) for the synthesis of heterosurface adsorbents (HAs) are optimized. Modification is performed by shielding the external surfaces of alkyl-modified silica (AS) using human serum albumin and its subsequent crosslinking. The structural and geometric characteristics of the SM, AS, and HA are measured via low-temperature nitrogen adsorption. It is found that the structural characteristics of AS pores with diameters D 9 nm reduces significantly due to adsorption of albumin. It is concluded that silica gel with a maximum pore size distribution close to 5 nm and a minimal proportion of pores with D > 9 nm is optimal for HA synthesis; this allows us to achieve the greatest similarity between the chromatographic retention parameters for HA and AS. The suitability of the synthesized adsorbents for analyzing drugs in biological fluids through direct sample injection is confirmed by chromatography. It was found that the percentage of the protein fraction detected at the outlet of the chromatographic column is 98%.

  20. 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.

  1. 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

  2. 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.

  3. 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...

  4. 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.

  5. 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...

  6. 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

  7. 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.

  8. 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.

  9. New type of amidoxime-group-containing adsorbent for the recovery of uranium from seawater. III. Recycle use of adsorbent

    International Nuclear Information System (INIS)

    Omichi, H.; Katakai, A.; Sugo, T.; Okamoto, J.

    1986-01-01

    An amidoxime-group adsorbent for recovering uranium from seawater was made by radiation-induced graft polymerization of acrylonitrile onto polymeric fiber, followed by amidoximation. Uranium adsorption of the adsorbent contacted with seawater in a column increased with the increase in flow rate, then leveled off. The relationship between uranium adsorption in a batch process and the ratio of the amount of seawater to that of adsorbent was found to be effective in evaluating adsorbent contacted with any amount of seawater. The conditioning of the adsorbent with an alkaline solution at higher temperature (∼80 0 C) after the acid desorption recovered the adsorption ability to the original level. This made it possible to apply the adsorbent to recycle use. On the other hand, the adsorbent conditioned at room temperature or that without conditioning lost adsorption ability during recycle use. The increase in water uptake was observed as one of the physical changes produced during recycle use of the alkaline-conditioned adsorbent, while the decrease in water uptake was observed with the unconditioned adsorbent. The IR spectra of the adsorbent showed a probability of reactions of amidoxime groups with acid and alkaline solutions, which can explain the change in uranium adsorption during the adsorption-desorption cycle

  10. 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

  11. 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.

  12. 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)

  13. Adsorbent Alkali Conditioning for Uranium Adsorption from Seawater. Adsorbent Performance and Technology Cost Evaluation

    International Nuclear Information System (INIS)

    Tsouris, Costas; Mayes, Richard T.; Janke, Christopher James; Dai, Sheng; Das, S.; Liao, W.P.; Kuo, Li-Jung; Wood, Jordana; Gill, Gary; Byers, Maggie Flicker; Schneider, Eric

    2015-01-01

    The Fuel Resources program of the Fuel Cycle Research and Development program of the Office of Nuclear Energy (NE) is focused on identifying and implementing actions to assure that nuclear fuel resources are available in the United States. An immense source of uranium is seawater, which contains an estimated amount of 4.5 billion tonnes of dissolved uranium. This unconventional resource can provide a price cap and ensure centuries of uranium supply for future nuclear energy production. NE initiated a multidisciplinary program with participants from national laboratories, universities, and research institutes to enable technical breakthroughs related to uranium recovery from seawater. The goal is to develop advanced adsorbents to reduce the seawater uranium recovery technology cost and uncertainties. Under this program, Oak Ridge National Laboratory (ORNL) has developed a new amidoxime-based adsorbent of high surface area, which tripled the uranium capacity of leading Japanese adsorbents. Parallel efforts have been focused on the optimization of the physicochemical and operating parameters used during the preparation of the adsorbent for deployment. A set of parameters that need to be optimized are related to the conditioning of the adsorbent with alkali solution, which is necessary prior to adsorbent deployment. Previous work indicated that alkali-conditioning parameters significantly affect the adsorbent performance. Initiated in 2014, this study had as a goal to determine optimal parameters such as base type and concentration, temperature, and duration of conditioning that maximize the uranium adsorption performance of amidoxime functionalized adsorbent, while keeping the cost of uranium production low. After base-treatment at various conditions, samples of adsorbent developed at ORNL were tested in this study with batch simulated seawater solution of 8-ppm uranium concentration, batch seawater spiked with uranium nitrate at 75-100 ppb uranium, and continuous

  14. Adsorbent Alkali Conditioning for Uranium Adsorption from Seawater. Adsorbent Performance and Technology Cost Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Tsouris, Costas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mayes, Richard T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Janke, Christopher James [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dai, Sheng [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Das, S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liao, W. -P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kuo, Li-Jung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wood, Jordana [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gill, Gary [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Byers, Maggie Flicker [Univ. of Texas, Austin, TX (United States); Schneider, Eric [Univ. of Texas, Austin, TX (United States)

    2015-09-30

    The Fuel Resources program of the Fuel Cycle Research and Development program of the Office of Nuclear Energy (NE) is focused on identifying and implementing actions to assure that nuclear fuel resources are available in the United States. An immense source of uranium is seawater, which contains an estimated amount of 4.5 billion tonnes of dissolved uranium. This unconventional resource can provide a price cap and ensure centuries of uranium supply for future nuclear energy production. NE initiated a multidisciplinary program with participants from national laboratories, universities, and research institutes to enable technical breakthroughs related to uranium recovery from seawater. The goal is to develop advanced adsorbents to reduce the seawater uranium recovery technology cost and uncertainties. Under this program, Oak Ridge National Laboratory (ORNL) has developed a new amidoxime-based adsorbent of high surface area, which tripled the uranium capacity of leading Japanese adsorbents. Parallel efforts have been focused on the optimization of the physicochemical and operating parameters used during the preparation of the adsorbent for deployment. A set of parameters that need to be optimized are related to the conditioning of the adsorbent with alkali solution, which is necessary prior to adsorbent deployment. Previous work indicated that alkali-conditioning parameters significantly affect the adsorbent performance. Initiated in 2014, this study had as a goal to determine optimal parameters such as base type and concentration, temperature, and duration of conditioning that maximize the uranium adsorption performance of amidoxime functionalized adsorbent, while keeping the cost of uranium production low. After base-treatment at various conditions, samples of adsorbent developed at ORNL were tested in this study with batch simulated seawater solution of 8-ppm uranium concentration, batch seawater spiked with uranium nitrate at 75-100 ppb uranium, and continuous

  15. 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

  16. 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.

  17. 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%.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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)

  3. 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...

  4. 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)

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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)

  11. 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.

  12. Creation of the technical adsorbent from local raw materials

    International Nuclear Information System (INIS)

    Isobaev, M.D.; Davlatnazarova, M.D.; Abdullaev, T.H.

    2016-01-01

    The results showed the possibility of obtaining effective adsorbents of walnut shell and the sunflower for environmental purposes, in particular for the purification of polluted waters from heavy metals. It has been shown, that 1 g of walnut shell adsorbent can adsorb on its surface ions of lead in amount of 47% by weight. The dependence of the adsorption activity of the semi-coke received from walnut shell from particle size and concentration of the solution. (author)

  13. WGS-Adsorbent Reaction Studies at Laboratory Scale

    International Nuclear Information System (INIS)

    Marano, M.; Torreiro, Y.

    2014-01-01

    This document reports the most significant results obtained during the experimental work performed under task WGS adsorbent experimental studies within CAPHIGAS project (National Research Plan 2008-2011, ref: ENE2009-08002). The behavior of the binary adsorbent-catalyst system which will be used in the hybrid system is described in this document. Main results reported here were used during the design and development of the hybrid system adsorbent catalyst- membrane proposed in the CAPHIGAS project. The influence of main operating parameters and the optimized volume ratio adsorbent-catalyst are also presented in this report. (Author)

  14. Neutralization of Rubidium Adsorbate Electric Fields by Electron Attachment

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacek, J. A. [Univ. of Oklahoma, Norman, OK (United States); Kim, E. [Univ. of Nevada, Las Vegas, NV (United States); Rittenhouse, S. T. [Western Washington Univ., Bellingham, WA (United States); US Naval Academy, Annapolis, MD (United States); Weck, Philippe F [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sadeghpour, H. R. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Shaffer, J. P. [Univ. of Oklahoma, Norman, OK (United States)

    2015-10-01

    We investigate the (0001) surface of single crystal quartz with a submonolayer of Rb adsorbates. Using Rydberg atom electromagnetically induced transparency, we investigate the electric elds resulting from Rb adsorbed on the quartz surface, and measure the activation energy of the Rb adsorbates. We show that the Rb induces a negative electron affnity (NEA) on the quartz surface. The NEA surface allows for low energy electrons to bind to the surface and cancel the electric eld from the Rb adsorbates. Our results have implications for integrating Rydberg atoms into hybrid quantum systems and the fundamental study of atom-surface interactions, as well as applications for electrons bound to a 2D surface.

  15. 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

  16. Theoretical Insight of Physical Adsorption for a Single-Component Adsorbent + Adsorbate System: I. Thermodynamic Property Surfaces

    KAUST Repository

    Chakraborty, Anutosh

    2009-02-17

    Thermodynamic property surfaces for a single-component adsorbent + adsorbate system are derived and developed from the viewpoint of classical thermodynamics, thermodynamic requirements of chemical equilibrium, Gibbs law, and Maxwell relations. They enable us to compute the entropy and enthalpy of the adsorbed phase, the isosteric heat of adsorption, specific heat capacity, and the adsorbed phase volume thoroughly. These equations are very simple and easy to handle for calculating the energetic performances of any adsorption system. We have shown here that the derived thermodynamic formulations fill up the information gap with respect to the state of adsorbed phase to dispel the confusion as to what is the actual state of the adsorbed phase. We have also discussed and established the temperature-entropy diagrams of (i) CaCl 2-in-silica gel + water system for cooling applications, and (ii) activated carbon (Maxsorb III) + methane system for gas storage. © Copyright 2009 American Chemical Society.

  17. Simultaneous separation of copper, cadmium and cobalt from sea-water by co-flotation with octadecylamine and ferric hydroxide as collectors.

    Science.gov (United States)

    Cabezon, L M; Caballero, M; Cela, R; Perez-Bustamante, J A

    1984-08-01

    A method is proposed for the simultaneous quantitative separation of traces ofCu(II), Cd(II) and Co(II) from sea-water samples by means of the co-flotation (adsorbing colloid flotation) technique with ferric hydroxide as co-precipitant and octadecylamine as collector. The experimental parameters have been studied and optimized. The drawbacks arising from the low solubility of octadecylamine and the corresponding sublates in water have been avoided by use of a 6M hydrochloric acid-MIBK-ethanol (1:2:2 v v ) mixture. The results obtained by means of the proposed method have been compared with those given by the usual ammonium pyrrolidine dithiocarbamate/MIBK extraction method.

  18. Ion exchange/adsorbent pilot plant

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    A decontamination of greater than 99% of the actinides and fission products contained in radioactive waste water can be obtained using ion exchange resins. A system for achieving this result is described in this paper. This ion exchange pilot-plant design is the culmination of five years of study of the decontamination of radioactive waste streams by ion exchange resins and other adsorbents at Mound. In order to maintain maximum flexibility of treatments, this pilot-plant design is a conceptual design with specific flows, resins, and column specifications, but with many optional features and no rigid equipment specifications. This flexibility allows the system to be amenable to almost any radioactive waste stream. Very specific designs can be constructed from this conceptual design for the treatment of any specific waste stream. Operating and capital costs are also discussed. 1 figure, 5 tables

  19. Canyon solvent cleaning with solid adsorbents

    International Nuclear Information System (INIS)

    Reif, D.J.

    1987-01-01

    The HM Process at the Savannah River Plant (SRP) uses 7.5% tributyl phosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, product decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown that carbonate washing, although removing residual solvent activity, does not remove binding ligands that hold fission products in the solvent. Treatment of solvent with a solid adsorbent removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale adsorption process and the use of the process to clean HM Process first cycle solvent are presented

  20. Arsenic Remediation by Synthetic and Natural Adsorbents

    Directory of Open Access Journals (Sweden)

    Muhammad Saqaf Jagirani

    2017-06-01

    Full Text Available The contagion of toxic metals in water is a serious environmental and health concern and threatening problem worldwide. Particularly arsenic contamination in ground water has became great dilemma in the earlier decades. With advent in research for arsenic remediation, standard of drinking water is improving and now reduced to few parts per million (ppm level of arsenic in drinking water sources. However, due to continuous enhancement in environmental pollution, remediation techniques are still needed to achieve the drinking water quality standard. Development of novel and economically feasible removal techniques or materials for selective separation of this toxic specie has been the main focus of research. Several arsenic removal techniques, including membrane separation, coagulation, precipitation, anion exchange have been developed. The aim of this article is to review briefly arsenic chemistry and previous and current available technologies that have been reported various low-cost adsorbents for arsenic removal.

  1. The condensation of water on adsorbed viruses.

    Science.gov (United States)

    Alonso, José María; Tatti, Francesco; Chuvilin, Andrey; Mam, Keriya; Ondarçuhu, Thierry; Bittner, Alexander M

    2013-11-26

    The wetting and dewetting behavior of biological nanostructures and to a greater degree single molecules is not well-known even though their contact with water is the basis for all biology. Here, we show that environmental electron microscopy (EM) can be applied as a means of imaging the condensation of water onto viruses. We captured the formation of submicrometer water droplets and filaments on single viral particles by environmental EM and by environmental transmission EM. The condensate structures are compatible with capillary condensation between adsorbed virus particles and with known droplet shapes on patterned surfaces. Our results confirm that such droplets exist down to condensation/evaporation cycle as expected from their stability in air and water. Moreover we developed procedures that overcome problems of beam damage and of resolving structures with a low atomic number.

  2. Applications of core level spectroscopy to adsorbates

    International Nuclear Information System (INIS)

    Nilsson, Anders

    2002-01-01

    In the following review different applications of core-level spectroscopy to atomic and molecular adsorbates will be shown. Core-holes are created through core-level ionization and X-ray absorption processes and the core-hole decays by radiant and non-radiant processes. This forms the basis for X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, Auger electron spectroscopy and X-ray emission spectroscopy. We will demonstrate how we can use the different methods to obtain information about the chemical state, local geometric structure, nature of chemical bonding and dynamics in electron transfer processes. The adsorption of N 2 and CO on Ni(100) will be used as prototype systems for chemisorption while N 2 on graphite and Ar on Pt for physisorption

  3. In vitro hydroxyapatite adsorbed salivary proteins

    International Nuclear Information System (INIS)

    Vitorino, Rui; Lobo, Maria Joao C.; Duarte, Jose; Ferrer-Correia, Antonio J.; Tomer, Kenneth B.; Dubin, Joshua R.; Domingues, Pedro M.; Amado, Francisco M.L.

    2004-01-01

    In spite of the present knowledge about saliva components and their respective functions, the mechanism(s) of pellicle and dental plaque formation have hitherto remained obscure. This has prompted recent efforts on in vitro studies using hydroxyapatite (HA) as an enamel model. In the present study salivary proteins adsorbed to HA were extracted with TFA and EDTA and resolved by 2D electrophoresis over a pH range between 3 and 10, digested, and then analysed by MALDI-TOF/TOF mass spectrometry and tandem mass spectrometry. Nineteen different proteins were identified using automated MS and MS/MS data acquisition. Among them, cystatins, amylase, carbonic anhydrase, and calgranulin B, were identified

  4. 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...

  5. 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

  6. 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

  7. Biodegradation of bacterial polysaccharides adsorbed on montmorillonite

    International Nuclear Information System (INIS)

    Guckert, A.; Tok, H.H.; Jacquin, F.

    1977-01-01

    In this research, by means of a model, a study was made of the biodegradation of microbial organic compounds adsorbed on clays, with a parallel experiment on Fontainebleau sand serving as the control. During incubation the three classes of organic matter ( 14 C-labelled glucose, 14 C-labelled polysaccharides and 14 C-labelled microbial cells) mineralize more actively in the presence of sand than in the presence of clay, since the latter provides protection against biodegradation. Mineralization of the adsorbed organic compounds, however, is marked by clear-cut differences after three weeks - glucose (55%)>polysaccharides (43%)>microbial organisms (7.3%). After incubation, chemical extraction of the organo-mineral complexes by alkaline solvents shows only water-soluble and alkali-soluble products in the case of sand; conversely, in that of montmorillonite the bulk of the 14 C was found in the non-extractable fraction or humin (18.1% of the initial 14 C for glucose, 27.3% for the polysaccharides, and 67.6% for the microbial organisms). A second incubation carried out after a phase in which there was drying and remoistening of the organo-mineral complexes, brings to light the important part played by climatic alternations during the biodegradation process. A new mineralization phase is observed, affecting more the bacterial organisms (14.1%) than the polysaccharides (6.3%), with the glucose-base complexes occupying an intermediate position (11.2%). The chemical fractioning of the organo-mineral complexes following re-incubation shows the stability of 14 C in humin very clearly, especially in the case of polysaccharides, where the mineralization phase relates primarily to the products extractable with alkalis. (author)

  8. 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.)

  9. 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.

  10. 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.)

  11. 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.

  12. 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.

  13. 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.

  14. 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)

  15. 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

  16. Understanding Trends in Catalytic Activity: The Effect of Adsorbate-Adsorbate Interactions for CO Oxidation Over Transition Metals

    DEFF Research Database (Denmark)

    Grabow, Lars; Larsen, Britt Hvolbæk; Nørskov, Jens Kehlet

    2010-01-01

    Using high temperature CO oxidation as the example, trends in the reactivity of transition metals are discussed on the basis of density functional theory (DFT) calculations. Volcano type relations between the catalytic rate and adsorption energies of important intermediates are introduced...... and the effect of adsorbate-adsorbate interaction on the trends is discussed. We find that adsorbate-adsorbate interactions significantly increase the activity of strong binding metals (left side of the volcano) but the interactions do not change the relative activity of different metals and have a very small...... influence on the position of the top of the volcano, that is, on which metal is the best catalyst....

  17. Synthesis of porphyryl boronates with (un)saturated side-chains

    OpenAIRE

    SENGE, MATHIAS; SERGEEVA, NATALIA

    2008-01-01

    PUBLISHED Porphyrins with (un)saturated side?chains containing boron residues were developed as synthons for porphyrin functionalization. Porphyrins with mono and bis-substituted unsaturated boronyl residues were prepared in good yields (52?66 %) using a cross?metathesis approach in the presence of Grubbs I-generation catalysts. In all cases complete E?stereoselectivity (100 %) was observed. Furthermore, formal cross?metathesis products with ?,??unsaturated chains smoothly underwent additi...

  18. Modeling field scale unsaturated flow and transport processes

    International Nuclear Information System (INIS)

    Gelhar, L.W.; Celia, M.A.; McLaughlin, D.

    1994-08-01

    The scales of concern in subsurface transport of contaminants from low-level radioactive waste disposal facilities are in the range of 1 to 1,000 m. Natural geologic materials generally show very substantial spatial variability in hydraulic properties over this range of scales. Such heterogeneity can significantly influence the migration of contaminants. It is also envisioned that complex earth structures will be constructed to isolate the waste and minimize infiltration of water into the facility. The flow of water and gases through such facilities must also be a concern. A stochastic theory describing unsaturated flow and contamination transport in naturally heterogeneous soils has been enhanced by adopting a more realistic characterization of soil variability. The enhanced theory is used to predict field-scale effective properties and variances of tension and moisture content. Applications illustrate the important effects of small-scale heterogeneity on large-scale anisotropy and hysteresis and demonstrate the feasibility of simulating two-dimensional flow systems at time and space scales of interest in radioactive waste disposal investigations. Numerical algorithms for predicting field scale unsaturated flow and contaminant transport have been improved by requiring them to respect fundamental physical principles such as mass conservation. These algorithms are able to provide realistic simulations of systems with very dry initial conditions and high degrees of heterogeneity. Numerical simulation of the movement of water and air in unsaturated soils has demonstrated the importance of air pathways for contaminant transport. The stochastic flow and transport theory has been used to develop a systematic approach to performance assessment and site characterization. Hypothesis-testing techniques have been used to determine whether model predictions are consistent with observed data

  19. Unsaturated Zone and Saturated Zone Transport Properties (U0100)

    Energy Technology Data Exchange (ETDEWEB)

    J. Conca

    2000-12-20

    This Analysis/Model Report (AMR) summarizes transport properties for the lower unsaturated zone hydrogeologic units and the saturated zone at Yucca Mountain and provides a summary of data from the Busted Butte Unsaturated Zone Transport Test (UZTT). The purpose of this report is to summarize the sorption and transport knowledge relevant to flow and transport in the units below Yucca Mountain and to provide backup documentation for the sorption parameters decided upon for each rock type. Because of the complexity of processes such as sorption, and because of the lack of direct data for many conditions that may be relevant for Yucca Mountain, data from systems outside of Yucca Mountain are also included. The data reported in this AMR will be used in Total System Performance Assessment (TSPA) calculations and as general scientific support for various Process Model Reports (PMRs) requiring knowledge of the transport properties of different materials. This report provides, but is not limited to, sorption coefficients and other relevant thermodynamic and transport properties for the radioisotopes of concern, especially neptunium (Np), plutonium (Pu), Uranium (U), technetium (Tc), iodine (I), and selenium (Se). The unsaturated-zone (UZ) transport properties in the vitric Calico Hills (CHv) are discussed, as are colloidal transport data based on the Busted Butte UZTT, the saturated tuff, and alluvium. These values were determined through expert elicitation, direct measurements, and data analysis. The transport parameters include information on interactions of the fractures and matrix. In addition, core matrix permeability data from the Busted Butte UZTT are summarized by both percent alteration and dispersion.

  20. Unsaturated Zone and Saturated Zone Transport Properties (U0100)

    International Nuclear Information System (INIS)

    Conca, J.

    2000-01-01

    This Analysis/Model Report (AMR) summarizes transport properties for the lower unsaturated zone hydrogeologic units and the saturated zone at Yucca Mountain and provides a summary of data from the Busted Butte Unsaturated Zone Transport Test (UZTT). The purpose of this report is to summarize the sorption and transport knowledge relevant to flow and transport in the units below Yucca Mountain and to provide backup documentation for the sorption parameters decided upon for each rock type. Because of the complexity of processes such as sorption, and because of the lack of direct data for many conditions that may be relevant for Yucca Mountain, data from systems outside of Yucca Mountain are also included. The data reported in this AMR will be used in Total System Performance Assessment (TSPA) calculations and as general scientific support for various Process Model Reports (PMRs) requiring knowledge of the transport properties of different materials. This report provides, but is not limited to, sorption coefficients and other relevant thermodynamic and transport properties for the radioisotopes of concern, especially neptunium (Np), plutonium (Pu), Uranium (U), technetium (Tc), iodine (I), and selenium (Se). The unsaturated-zone (UZ) transport properties in the vitric Calico Hills (CHv) are discussed, as are colloidal transport data based on the Busted Butte UZTT, the saturated tuff, and alluvium. These values were determined through expert elicitation, direct measurements, and data analysis. The transport parameters include information on interactions of the fractures and matrix. In addition, core matrix permeability data from the Busted Butte UZTT are summarized by both percent alteration and dispersion

  1. 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...

  2. Hypolipidemic action of garlic unsaturated oils in irradiated mice

    International Nuclear Information System (INIS)

    Gupta, N.K.

    1988-01-01

    Adult male Swiss albino mice were injected with 74 KBq g -1 body weight of radiocalcium 45 Ca in the presence and absence of unsaturated oils of garlic, and changes in the total lipids and triglycerides contents of liver were observed at various intervals from 1 to 14 days. The results obtained indic ate that the garlic oils prevented rapid increase in hepatic total lipids and triglycerides induced by radiocalcium and the values reached normal values earlier in garlic-treated than in irradiated animals. Possible mechanism(s) underlying hypolipidemic action of garlic oil have been discussed. (author). 22 refs

  3. NNWSI waste form test method for unsaturated disposal conditions

    International Nuclear Information System (INIS)

    Bates, J.K.; Gerding, T.J.

    1985-03-01

    A test method has been developed to measure the release of radionuclides from the waste package under simulated NNWSI repository conditions, and to provide information concerning materials interactions that may occur in the repository. Data are presented from Unsaturated testing of simulated Savannah River Laboratory 165 glass completed through 26 weeks. The relationship between these results and those from parametric and analog testing are described. The data indicate that the waste form test is capable of producing consistent, reproducible results that will be useful in evaluating the role of the waste package in the long-term performance of the repository. 6 refs., 7 figs., 5 tabs

  4. Processing of Unsaturated Organic Acid Aerosols by Ozone

    Science.gov (United States)

    Aloisio, S.; Donaldson, D. J.; Eliason, T. L.; Cziczo, D.; Vaida, V.

    2002-05-01

    We present results of in-situ studies of the oxidative "processing" of organic aerosols composed of unsaturated organic compounds. Aerosol samples of 2-octenoic acid and undecylenic acid were exposed to approx. 10 mbar ozone in a room temperature, atmospheric pressure flow tube reactor. In-situ spectroscopic probing of the reaction mixture, as well as GC-MS analysis of the flow tube effluent, shows evidence of efficient oxidation of double bonds in the organic species, with production of gas-phase and aerosol phase ozonolysis products.

  5. Estimating unsaturated hydraulic conductivity from soil moisture-tim function

    International Nuclear Information System (INIS)

    El Gendy, R.W.

    2002-01-01

    The unsaturated hydraulic conductivity for soil can be estimated from o(t) function, and the dimensionless soil water content parameter (Se)Se (β - βr)/ (φ - θ)), where θ, is the soil water content at any time (from soil moisture depletion curve l; θ is the residual water content and θ, is the total soil porosity (equals saturation point). Se can be represented as a time function (Se = a t b ), where t, is the measurement time and (a and b) are the regression constants. The recommended equation in this method is given by

  6. Study of transport in unsaturated sands using radioactive tracers

    International Nuclear Information System (INIS)

    Merritt, W.F.; Pickens, J.F.; Allison, G.B.

    1979-01-01

    A laboratory experiment was conducted to investigate the mixing that occurs as a series of labelled pulses of water are transported by gravity drainage down through a sand filled column having a water table imposed at the bottom. It also demonstrated the utility of gamma-ray emitting radioactive tracers in studying transport in unsaturated or saturated porous media. The motivation for pursuing this topic was developed from observing that the content of oxygen-18, deuterium and tritium in rainwater shows marked temporal variations whereas their concentrations below the water table in shallow ground water flow systems are generally found to show much less variation. (auth)

  7. Chemo-hydro-mechanical behaviour of unsaturated clays

    International Nuclear Information System (INIS)

    Mokni, N.; Olivella, S.; Alonso, E.E.; Romero, E.

    2010-01-01

    Document available in extended abstract form only. Understanding of the chemical effects on clays is essential for many problems ranging from pollution studies and waste-containment. Several studies examined the effect of changes in pore fluid composition on the mechanical and hydraulic properties. Volume changes (contraction/ expansion) have been measured on clay specimens upon exposure to salt solutions or permeation with organic liquids. Moreover, it was shown that permeation of clay with brine induces an increase of the shear strength. In addition, several models have been proposed to describe the chemo-mechanical behaviour of saturated clays under saturated conditions. A new chemo-hydro-mechanical model for unsaturated clays is under development. The chemo-mechanical effects are described within an elasto-plastic framework using the concept that chemical effects act on the plastic properties by increasing or decreasing the pre-consolidation stress. The model is based on the distinction within the material of a microstructural and a macro-structural levels. Chemical loading has a significant effect on the microstructure. The negative pressure associated with the capillary water plays its role in the interconnected macro pores. By adopting simple assumptions concerning the coupling between the two levels it is intended to reproduce the features of the behaviour of unsaturated clays when there is a change in pore fluid composition (increase or decrease of concentration). A yield surface which defines the set of yield pre-consolidation stress values, for each associated capillary suction and concentration of pore fluid should be defined. In addition, the behaviour of clays under unsaturated condition and the behaviour at full saturation under chemical loading represent two limiting cases of the framework. Studies on the compatibility of Boom Clay with large amounts of nitrate- bearing bituminized radioactive waste have recently raised a particular interest on the

  8. Asymptotically optimal unsaturated lattice cubature formulae with bounded boundary layer

    Energy Technology Data Exchange (ETDEWEB)

    Ramazanov, M D [Institute of Mathematics with Computing Centre, Ufa Science Centre, Russian Academy of Sciences, Ufa (Russian Federation)

    2013-07-31

    This paper describes a new algorithm for constructing lattice cubature formulae with bounded boundary layer. These formulae are unsaturated (in the sense of Babenko) both with respect to the order and in regard to the property of asymptotic optimality on W{sub 2}{sup m}-spaces, m element of (n/2,∞). Most of the results obtained apply also to W{sub 2}{sup μ}(R{sup n})-spaces with a hypoelliptic multiplier of smoothness μ. Bibliography: 6 titles.

  9. Effect of Structure Change on Radiation Crosslinking of Unsaturated Polyesters

    International Nuclear Information System (INIS)

    Ranogajec, F.

    2006-01-01

    During the course of crosslinking of unsaturated polyesters reacting system, that was liquid prior to reaction, gels, and becomes solid. Crosslinking reaction begins to be controlled by the change of the physical state of the system at an early stage of reaction. The kinetics can not be studied by the usual kinetical methods. In-source 60 C o gamma rays induced crosslinking of unsaturated polyester with styrene was followed directly and continuously by measuring electrical conductivity change. The results of extraction analysis proved good correlation between the change of electrical conductivity and the extent of curing. The gel content was inversely proportional to conductivity and free styrene content directly proportional to conductivity. DC-electrical conductivity has shown high sensitivity toward structural changes and enabled us to detect liquid-liquid transitions in unsaturated polyester. The upper liquid-liquid transition (T l ρ) is less known transition caused by a stepwise decrease of intramolecular short-range local order that remains above the glass and lower liquid-liquid transitions. The local order is based on secondary valent interactions and is enhanced by hydrogen bonding. The linear temperature dependence of the viscosity and dc electrical conductivity of unsaturated polyesters showed a change of slope caused by the (T l ρ). Those changes were the result of the diminishing of the local order (which includes several bond lengths) caused by breaking of the intramolecular interactions. The intramolecular nature of the (T l ρ) in the polyesters under consideration was proved by its insensitivity to crosslinking and dilution with solvents. In the corresponding temperature range, DSC thermograms shoved expected endothermic changes. The structure changes related to the (T l ρ) in the investigated polyesters were determined by 1 H NMR and NIR spectroscopy. The proton NMR indicated that the stepwise change in hydrogen bonding occurred in the

  10. A nuclear standard high-efficiency adsorber for iodine

    International Nuclear Information System (INIS)

    Wang Jianmin; Qian Yinge

    1988-08-01

    The structure of a nuclear standard high-efficiency adsorber, adsorbent and its performance are introduced. The performance and structure were compared with the same kind product of other firms. The results show that the leakage rate is less than 0.005%

  11. Comparative evaluation of selected starches as adsorbent for Thin ...

    African Journals Online (AJOL)

    The most commonly used is silica gel which is an inorganic adsorbent. Organic substances like cellulose, polyethylene are also used. All these are imported into Nigeria and are unhealthy for economic policies. Most commonly used adsorbent may not be easy to produce locally, but starch, which is a very common product, ...

  12. Synthesis and properties of porous zeolite aluminosilicate adsorbents

    International Nuclear Information System (INIS)

    Shilina, A.S.; Milinchuk, V.K.; Burukhin, S.B.; Gordienko, A.B.

    2015-01-01

    Environmentally safe non-energy-intensive methods of the synthesis have been developed and the properties of solid inorganic nanostructured zeolite-like adsorbents of a broad spectrum have been studied. The sorption capacities of the adsorbents with respect to various components of water pollution have been determined [ru

  13. Development of ultrafiltration and inorganic adsorbents: January--March 1977

    International Nuclear Information System (INIS)

    Koenst, J.W. Jr.

    1977-01-01

    Ultrafiltration media with and without the assistance of bone char filters were evaluated to determine their effectiveness in removing radionuclides from contaminated solutions. Precipitants, resin, adsorbents, and inorganic adsorbents were studied to determine their effectiveness in decontaminating solutions. A study of the effects of radiation on ultrafiltration media was initiated. An ultrafiltration media pilot plant was ordered and is being installed

  14. Friction and diffusion dynamics of adsorbates at surfaces

    NARCIS (Netherlands)

    Fusco, C.

    2005-01-01

    A theoretical study of the motion of adsorbates (e. g. atoms, molecules or clusters) on solid surfaces is presented, with a focus on surface diffusion and atomic-scale friction. These two phenomena are inextricably linked, because when an atomic or molecular adsorbate diffuses, or is pulled, it

  15. Mixed-matrix membrane adsorbers for protein separation

    NARCIS (Netherlands)

    Avramescu, M.E.; Borneman, Z.; Wessling, M.

    2003-01-01

    The separation of two similarly sized proteins, bovine serum albumin (BSA) and bovine hemoglobin (Hb) was carried out using a new type of ion-exchange mixed-matrix adsorber membranes. The adsorber membranes were prepared by incorporation of various types of Lewatit ion-exchange resins into an

  16. Single bank NOx adsorber for heavy duty diesel engines

    NARCIS (Netherlands)

    Genderen, M. van; Aken, M.G. van

    2003-01-01

    In a NOx adsorber programme the feasibility for applying this technology to heavy duty diesel engines was investigated. After modelling and simulations for realising best λ < 1 engine conditions a platform was build which was used to obtain good NOx adsorber regeneration settings in a number of

  17. 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.

  18. 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)

  19. 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

  20. 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.