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Sample records for copper current collector

  1. Copper current collectors reduce long-term fouling of air cathodes in microbial fuel cells

    KAUST Repository

    Myung, Jaewook; Yang, Wulin; Saikaly, Pascal; Logan, Bruce E

    2018-01-01

    Long-term operation of wastewater-fed, microbial fuel cells (MFCs) with cathodes made of activated carbon and stainless steel (SS) current collectors can result in decreased performance due to cathode fouling. Copper has good antimicrobial properties, and it is more electrically conductive than SS. To demonstrate that a copper current collector could produce a more fouling resistant cathode, MFCs with air cathodes using either SS or copper current collectors were operated using domestic wastewater for 27 weeks. The reduction in biofouling over time was shown by less biofilm formation on the copper cathode surface compared to SS cathodes, due to the antimicrobial properties of copper. Maximum power densities from 17–27 weeks were 440 ± 38 mW/m2 using copper and 370 ± 21 mW/m2 using SS cathodes. The main difference in the microbial community was a nitrifying community on the SS cathodes, which was not present on the copper cathodes.

  2. Copper current collectors reduce long-term fouling of air cathodes in microbial fuel cells

    KAUST Repository

    Myung, Jaewook

    2018-02-05

    Long-term operation of wastewater-fed, microbial fuel cells (MFCs) with cathodes made of activated carbon and stainless steel (SS) current collectors can result in decreased performance due to cathode fouling. Copper has good antimicrobial properties, and it is more electrically conductive than SS. To demonstrate that a copper current collector could produce a more fouling resistant cathode, MFCs with air cathodes using either SS or copper current collectors were operated using domestic wastewater for 27 weeks. The reduction in biofouling over time was shown by less biofilm formation on the copper cathode surface compared to SS cathodes, due to the antimicrobial properties of copper. Maximum power densities from 17–27 weeks were 440 ± 38 mW/m2 using copper and 370 ± 21 mW/m2 using SS cathodes. The main difference in the microbial community was a nitrifying community on the SS cathodes, which was not present on the copper cathodes.

  3. Fragmentation of copper current collectors in Li-ion batteries during spherical indentation

    International Nuclear Information System (INIS)

    Wang, Hsin; Watkins, Thomas R.; Simunovic, Srdjan; Bingham, Philip R.; Allu, Srikanth; Turner, John A.

    2017-01-01

    Large, areal, brittle fracture of copper current collector foils was observed by 3D x-ray computed tomography (XCT) of a spherically indented Li-ion cell. This fracture was hidden and non-catastrophic to a degree because the graphite layers deformed plastically, and held the materials together so that the cracks in the foils could not be seen under optical and electron microscopy. 3D XCT on the indented cell showed “mud cracks” within the copper layer. The cracking of copper foils could not be immediately confirmed when the cell was opened for post-mortem examination. However, an X-ray radiograph on a single foil of the Cu anode showed clearly that the copper foil had broken into multiple pieces similar to the brittle cracking of a ceramic under indentation. This new failure mode of anodes on Li-ion cell has very important implications on the behavior of Li-ion cells under mechanical abuse conditions. Furthermore, the fragmentation of current collectors in the anode must be taken into consideration for the electrochemical responses which may lead to capacity loss and affect thermal runaway behavior of the cells.

  4. High Performance Carbon Nanotube Yarn Supercapacitors with a Surface-Oxidized Copper Current Collector.

    Science.gov (United States)

    Zhang, Daohong; Wu, Yunlong; Li, Ting; Huang, Yin; Zhang, Aiqing; Miao, Menghe

    2015-11-25

    Threadlike linear supercapacitors have demonstrated high potential for constructing fabrics to power electronic textiles (eTextiles). To improve the cyclic electrochemical performance and to produce power fabrics large enough for practical applications, a current collector has been introduced into the linear supercapcitors to transport charges produced by active materials along the length of the supercapacitor with high efficiency. Here, we first screened six candidate metal filaments (Pt, Au, Ag, AuAg, PtCu, and Cu) as current collectors for carbon nanotube (CNT) yarn-based linear supercapacitors. Although all of the metal filaments significantly improved the electrochemical performance of the linear supercapacitor, two supercapacitors constructed from Cu and PtCu filaments, respectively, demonstrate far better electrochemical performance than the other four supercapacitors. Further investigation shows that the surfaces of the two Cu-containing filaments are oxidized by the surrounding polymer electrolyte in the electrode. While the unoxidized core of the Cu-containing filaments remains highly conductive and functions as a current collector, the resulting CuO on the surface is an electrochemically active material. The linear supercapacitor architecture incorporating dual active materials CNT + Cu extends the potential window from 1.0 to 1.4 V, leading to significant improvement to the energy density and power density.

  5. Molecular Dynamics Study of the Separation Behavior at the Interface between PVDF Binder and Copper Current Collector

    Directory of Open Access Journals (Sweden)

    Seungjun Lee

    2016-01-01

    Full Text Available In Li-ion batteries, the mechanical strengths at the interfaces of binder/particle and binder/current collector play an important role in maintaining the mechanical integrity of the composite electrode. In this work, the separation behaviors between polyvinylidene fluoride (PVDF binders and copper current collectors are studied in the opening and sliding modes using molecular dynamics (MD simulations. The simulation shows that the separation occurs inside the PVDF rather than at the interface due to the strong adhesion between PVDF and copper. This fracture behavior is different from the behavior of the PVDF/graphite basal plane that shows a clear separation at the interface. The results suggest that the adhesion strength of the PVDF/copper is stronger than that of the PVDF/graphite basal plane. The methodology used in MD simulation can directly evaluate the adhesion strength at the interfaces of various materials between binders, substrates, and particles at the atomic scales. The proposed method can therefore provide a guideline for the design of the electrode in order to enhance the mechanical integrity for better battery performance.

  6. Embroidered Copper Microwire Current Collector for Improved Cycling Performance of Silicon Anodes in Lithium-Ion Batteries.

    Science.gov (United States)

    Breitung, Ben; Aguiló-Aguayo, Noemí; Bechtold, Thomas; Hahn, Horst; Janek, Jürgen; Brezesinski, Torsten

    2017-10-12

    Si holds great promise as an alloying anode material for Li-ion batteries with improved energy density because of its high theoretical specific capacity and favorable operation voltage range. However, the large volume expansion of Si during electrochemical reaction with Li and the associated adverse effects strongly limit its prospect for application. Here, we report on the use of three-dimensional instead of flat current collectors for high-capacity Si anodes in an attempt to mitigate the loss of electrical contact of active electrode regions as a result of structural disintegration with cycling. The current collectors were produced by technical embroidery and consist of interconnected Cu wires of diameter <150 µm. In comparison to Si/Li cells using a conventional Cu foil current collector, the embroidered microwire network-based cells show much enhanced capacity and reversibility due to a higher degree of tolerance to cycling.

  7. 3D morphological analysis of copper foams as current collectors for Li-ion batteries by means of X-ray tomography

    Energy Technology Data Exchange (ETDEWEB)

    Etiemble, A. [Institut National des Sciences Appliquées de Lyon, Laboratoire MATEIS, F-69621 Villeurbanne (France); Institut National de la Recherche Scientifique – Centre Énergie, Matériaux, Télécommunications, Varennes, Québec J3X 1S2 (Canada); Adrien, J. [Institut National des Sciences Appliquées de Lyon, Laboratoire MATEIS, F-69621 Villeurbanne (France); Maire, E., E-mail: eric.maire@insa-lyon.fr [Institut National des Sciences Appliquées de Lyon, Laboratoire MATEIS, F-69621 Villeurbanne (France); Idrissi, H. [Institut National des Sciences Appliquées de Lyon, Laboratoire MATEIS, F-69621 Villeurbanne (France); Reyter, D. [Institut National de la Recherche Scientifique – Centre Énergie, Matériaux, Télécommunications, Varennes, Québec J3X 1S2 (Canada); Roué, L., E-mail: roue@emt.inrs.ca [Institut National de la Recherche Scientifique – Centre Énergie, Matériaux, Télécommunications, Varennes, Québec J3X 1S2 (Canada)

    2014-09-15

    Highlights: • X-ray tomography analysis of open-cell copper foams is performed. • The effect of a dissolution treatment on the foam morphology is highlighted. • The interest of such Cu foams as current collectors for Li-ion batteries is discussed. - Abstract: As-received and chemically treated copper foams were characterized by means of laboratory X-ray tomography with a resolution of 0.5 μm. 3D image processing and analysis allowed the morphological parameters (size, sphericity, tortuosity etc.) of the pores and copper skeleton to be determined. The chemical dissolution of the Cu foam in an acid hydrogen peroxide solution results in an increase of the open pore size (from 54 to 93 μm) and a decrease of the foam thickness (from 140 to 115 μm). With an open porosity of 81.8% and a specific surface area as high as 280,000 (49,000) m{sup 2}/m{sup 3} of Cu (foam), the chemically-treated Cu foam appears very attractive for use as a 3D current collector for metal (e.g. Si) based anodes for Li-ion batteries.

  8. 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.

  9. Hierarchical micro-lamella-structured 3D porous copper current collector coated with tin for advanced lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyeji [School of Materials Science and Engineering, Kookmin University, Seoul 136-702 (Korea, Republic of); Um, Ji Hyun [School of Chemical and Biological Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 151-742 (Korea, Republic of); Choi, Hyelim [School of Materials Science and Engineering, Kookmin University, Seoul 136-702 (Korea, Republic of); Yoon, Won-Sub [Department of Energy Science, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Sung, Yung-Eun [School of Chemical and Biological Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 151-742 (Korea, Republic of); Choe, Heeman, E-mail: heeman@kookmin.ac.kr [School of Materials Science and Engineering, Kookmin University, Seoul 136-702 (Korea, Republic of); Cellmotive Co. Ltd., #518, Engineering Building, Kookmin University, Seoul 136-702 (Korea, Republic of)

    2017-03-31

    Highlights: • Sn-Cu scaffold anode fabricated by freeze-casting and electroless plating. • Sn-Cu scaffold architecture shows superior capacity and cyclic stability at high current density. • Sn-Cu scaffold electrode is commercially promising. - Abstract: A Novel 3D porous Sn-Cu architecture is prepared as an anode material for use in an advanced lithium-ion battery. Micro-lamellar-structured 3D porous Cu foam, which is electroless-plated with Sn as an active material, is used as anode current collector. Compared to Sn-coated Cu foil, the 3D Sn-Cu foam exhibits superior Li-ion capacity and stable capacity retention, demonstrating the advantage of 3D porous architecture by preserving its structural integrity. In addition, the effect of heat-treatment after Sn plating is investigated. Sn/Sn{sub 6}Cu{sub 5} and SnO{sub 2}/Cu{sub 10}Sn{sub 3} were formed on and in the 3D Sn-Cu foam under the heat-treatment at 150 °C and 500 °C, respectively. The development of Cu{sub 10}Sn{sub 3} in the 3D Sn-Cu foam heat-treated at 500 °C can be a key factor for the enhanced cyclic stability because the Cu{sub 10}Sn{sub 3} inactively reacts with Li-ion and alleviates the volume expansion of SnO{sub 2} as an inactive matrix.

  10. Temperature dependent capacity contribution of thermally treated anode current collectors in lithium ion batteries

    International Nuclear Information System (INIS)

    Kim, Tae Kwon; Li Xifei; Wang Chunlei

    2013-01-01

    Highlights: ► We studied the influence of the thermal treatment of current collectors on the energy capacity. ► Different current collectors show different thermal treatment effect on performance. ► The non-negligible capacity contribution is closely related to the treatment temperatures. ► Our results could be beneficial to designing battery architectures. - Abstract: Metal current collectors, offering a good connection between the active materials and the external circuit, is an important component in a rechargeable lithium ion battery. Some necessary thermal treatment in the battery fabrication and assembly procedure results in current collectors with some non-negligible reversible energy capacities; however, these energy capacities were negligible in the previous references. In this research, for the first time, we investigated the influence of the thermal treatment of current collectors (such as copper foil and stainless steel disk) on energy capacities. Our results indicate that different current collector materials have different thermal treatment effects on their electrochemical performance. The non-negligible capacity contribution is closely related to the treatment temperature.

  11. 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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  13. 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. A plug flow reactor model of a vanadium redox flow battery considering the conductive current collectors

    Science.gov (United States)

    König, S.; Suriyah, M. R.; Leibfried, T.

    2017-08-01

    A lumped-parameter model for vanadium redox flow batteries, which use metallic current collectors, is extended into a one-dimensional model using the plug flow reactor principle. Thus, the commonly used simplification of a perfectly mixed cell is no longer required. The resistances of the cell components are derived in the in-plane and through-plane directions. The copper current collector is the only component with a significant in-plane conductance, which allows for a simplified electrical network. The division of a full-scale flow cell into 10 layers in the direction of fluid flow represents a reasonable compromise between computational effort and accuracy. Due to the variations in the state of charge and thus the open circuit voltage of the electrolyte, the currents in the individual layers vary considerably. Hence, there are situations, in which the first layer, directly at the electrolyte input, carries a multiple of the last layer's current. The conventional model overestimates the cell performance. In the worst-case scenario, the more accurate 20-layer model yields a discharge capacity 9.4% smaller than that computed with the conventional model. The conductive current collector effectively eliminates the high over-potentials in the last layers of the plug flow reactor models that have been reported previously.

  15. Copper corrosion and its relationship to solar collectors:a compendium.

    Energy Technology Data Exchange (ETDEWEB)

    Menicucci, David F.; Mahoney, Alan Roderick

    2007-07-01

    Copper has many fine qualities that make it a useful material. It is highly conductive of both heat and electricity, is ductile and workable, and reasonably resistant to corrosion. Because of these advantages, the solar water heating industry has been using it since the mid-1970s as the material of choice for collectors, the fundamental component of a solar water heating system. In most cases copper has performed flawlessly, but in some situations it has been known to fail. Pitting corrosion is the usual failure mode, but erosion can also occur. In 2000 Sandia National Laboratories and the Copper Development Association were asked to analyze the appearance of pin-hole leaks in solar collector units installed in a housing development in Arizona, and in 2002 Sandia analyzed a pitting corrosion event that destroyed a collector system at Camp Pendleton. This report includes copies of the reports and accounts of these corrosion failures, and provides a bibliography with references to many papers and articles that might be of benefit to the solar community. It consolidates in a single source information that has been accumulated at Sandia relative to copper corrosion, especially as it relates to solar water heaters.

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  1. 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

  2. High-performance supercapacitors using a nanoporous current collector made from super-aligned carbon nanotubes

    Science.gov (United States)

    Zhou, Ruifeng; Meng, Chuizhou; Zhu, Feng; Li, Qunqing; Liu, Changhong; Fan, Shoushan; Jiang, Kaili

    2010-08-01

    Nanoporous current collectors for supercapacitors have been fabricated by cross-stacking super-aligned carbon nanotube (SACNT) films as a replacement for heavy conventional metallic current collectors. The CNT-film current collectors have good conductivity, extremely low density (27 µg cm - 2), high specific surface area, excellent flexibility and good electrochemical stability. Nanosized active materials such as NiO, Co3O4 or Mn2O3 nanoparticles can be directly synthesized on the SACNT films by a straightforward one-step, in situ decomposition strategy that is both efficient and environmentally friendly. These composite films can be integrated into a pseudo-capacitor that does not use metallic current collectors, but nevertheless shows very good performance, including high specific capacitance (~500 F g - 1, including the current collector mass), reliable electrochemical stability (<4.5% degradation in 2500 cycles) and a very high rate capability (245 F g - 1 at 155 A g - 1).

  3. Electrochemical Properties of Current Collector in the All-vanadium Redox Flow Battery

    International Nuclear Information System (INIS)

    Hwang, Gan-Jin; Oh, Yong-Hwan; Ryu, Cheol-Hwi; Choi, Ho-Sang

    2014-01-01

    Two commercial carbon plates were evaluated as a current collector (bipolar plate) in the all vanadium redox-flow battery (V-RFB). The performance properties of V-RFB were test in the current density of 60 mA/cm 2 . The electromotive forces (OCV at SOC 100%) of V-RFB using A and B current collector were 1.47 V and 1.54 V. The cell resistance of V-RFB using A current collector was 4.44-5.00 Ω·cm 2 and 3.28-3.75 Ω·cm 2 for charge and discharge, respectively. The cell resistance of V-RFB using B current collector was 4.19-4.42Ω·cm 2 and 4.71-5.49Ω·cm 2 for charge and discharge, respectively. The performance of V-RFB using each current collector was evaluated. The performance of V-RFB using A current collector was 93.1%, 76.8% and 71.4% for average current efficiency, average voltage efficiency and average energy efficiency, respectively. The performance of V-RFB using B current collector was 96.4%, 73.6% and 71.0% for average current efficiency, average voltage efficiency and average energy efficiency, respectively

  4. Thin Film Energy Storage Device with Spray‐Coated Sliver Paste Current Collector

    Directory of Open Access Journals (Sweden)

    Seong Man Yoon

    2017-12-01

    Full Text Available This paper challenges the fabrication of a thin film energy storage device on a flexible polymer substrate specifically by replacing most commonly used metal foil current collectors with coated current collectors. Mass‐manufacturable spray‐coating technology enables the fabrication of two different half‐cell electric double layer capacitors (EDLC with a spray‐coated silver paste current collector and a Ni foil current collector. The larger specific capacitances of the half‐cell EDLC with the spray‐coated silver current collector are obtained as 103.86 F/g and 76.8 F/g for scan rates of 10 mV/s and 500 mV/s, respectively. Further, even though the half‐cell EDLC with the spray‐coated current collector is heavier than that with the Ni foil current collector, smaller Warburg impedance and contact resistance are characterized from Nyquist plots. For the applied voltages ranging from −0.5 V to 0.5 V, the spray‐coated thin film energy storage device exhibits a better performance.

  5. Development of an air-breathing direct methanol fuel cell with the cathode shutter current collectors

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yufeng; Liu, Xiaowei [Key Laboratory of Micro-Systems and Micro-Structures Manufacturing, Ministry of Education, Harbin 150001 (China); MEMS Center, Harbin Institute of Technology, Harbin 150001 (China); Zhang, Peng; Zhang, Bo; Li, Jianmin; Deng, Huichao [MEMS Center, Harbin Institute of Technology, Harbin 150001 (China)

    2010-06-15

    An air-breathing direct methanol fuel cell with a novel cathode shutter current collector is fabricated to develop the power sources for consumer electronic devices. Compared with the conventional circular cathode current collector, the shutter one improves the oxygen consumption and mass transport. The anode and cathode current collectors are made of stainless steel using thermal stamping die process. Moreover, an encapsulation method using the tailor-made clamps is designed to assemble the current collectors and MEA for distributing the stress of the edges and inside uniformly. It is observed that the maximum power density of the air-breathing DMFC operating with 1 M methanol solution achieves 19.7 mW/cm{sup 2} at room temperature. Based on the individual DMFCs, the air-breathing stack consisting of 36 DMFC units is achieved and applied to power a notebook computer. (author)

  6. Experimental Investigation of a Direct Methanol Fuel Cell with Hilbert Fractal Current Collectors

    Directory of Open Access Journals (Sweden)

    Jing-Yi Chang

    2014-01-01

    Full Text Available The Hilbert curve is a continuous type of fractal space-filling curve. This fractal curve visits every point in a square grid with a size of 2×2, 4×4, or any other power of two. This paper presents Hilbert fractal curve application to direct methanol fuel cell (DMFC current collectors. The current collectors are carved following first, second, and third order Hilbert fractal curves. These curves give the current collectors different free open ratios and opening perimeters. We conducted an experimental investigation into DMFC performance as a function of the free open ratio and opening perimeter on the bipolar plates. Nyquist plots of the bipolar plates are made and compared using electrochemical impedance spectroscopy (EIS experiments to understand the phenomena in depth. The results obtained in this paper could be a good reference for future current collector design.

  7. Vertically oriented graphene bridging active-layer/current-collector interface for ultrahigh rate supercapacitors.

    Science.gov (United States)

    Bo, Zheng; Zhu, Weiguang; Ma, Wei; Wen, Zhenhai; Shuai, Xiaorui; Chen, Junhong; Yan, Jianhua; Wang, Zhihua; Cen, Kefa; Feng, Xinliang

    2013-10-25

    Dense networks of graphene nanosheets standing vertically on a current collector can work as numerous electrically conductive bridges to facilitate charge transport and mitigate the constriction/spreading resistance at the interface between the active material and the current collector. The vertically oriented graphene-bridged supercapacitors present excellent rate and power capabilities. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Metal-free current collectors based on graphene materials for supecapacitors produced by 3D printing

    Science.gov (United States)

    Baskakov, S. A.; Baskakova, Yu. V.; Lyskov, N. V.; Dremova, N. N.; Shul'ga, Yu. M.

    2017-10-01

    Supercapacitor (SC) current collectors with electrodes made of graphite oxide reduced during microwave exfoliation are produced from a commercial filament with a graphene component via layer-by-layer fusing with a 3D printer. The separator is made of a graphene oxide film. The current collectors are investigated by means of IR spectroscopy. Electrochemical tests are performed for the assembled SC that include tests of its cyclic stability up to 1000 cycles.

  9. Development of a Direct Methanol Fuel Cell with Lightweight Disc Type Current Collectors

    Directory of Open Access Journals (Sweden)

    Yean-Der Kuan

    2014-05-01

    Full Text Available The direct methanol fuel cell (DMFC adopts methanol solution as a fuel suitable for low power portable applications. A miniature, lightweight, passive air-breathing design is therefore desired. This paper presents a novel planar disc-type DMFC with multiple cells containing a novel developed lightweight current collector at both the anode and cathode sides. The present lightweight current collector adopts FR4 Glass/Epoxy as the substrate with the current collecting areas located at the corresponding membrane electrolyte assembly (MEA areas. The current collecting areas are fabricated by sequentially coating a corrosion resistant layer and electrical conduction layer via the thermal evaporation technique. The anode current collector has carved flow channels for fuel transport and production. The cathode current collector has drilled holes for passive air breathing. In order to ensure feasibility in the present concept a 3-cell prototype DMFC module with lightweight disc type current collectors is designed and constructed. Experiments were conducted to measure the cell performance. The results show that the highest cell power output is 54.88 mW·cm−2 and successfully demonstrate the feasibility of this novel design.

  10. High-performance supercapacitors using a nanoporous current collector made from super-aligned carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Ruifeng; Meng Chuizhou; Zhu Feng; Li Qunqing; Liu Changhong; Fan Shoushan; Jiang Kaili, E-mail: JiangKL@tsinghua.edu.cn [Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084 (China)

    2010-08-27

    Nanoporous current collectors for supercapacitors have been fabricated by cross-stacking super-aligned carbon nanotube (SACNT) films as a replacement for heavy conventional metallic current collectors. The CNT-film current collectors have good conductivity, extremely low density (27 {mu}g cm{sup -2}), high specific surface area, excellent flexibility and good electrochemical stability. Nanosized active materials such as NiO, Co{sub 3}O{sub 4} or Mn{sub 2}O{sub 3} nanoparticles can be directly synthesized on the SACNT films by a straightforward one-step, in situ decomposition strategy that is both efficient and environmentally friendly. These composite films can be integrated into a pseudo-capacitor that does not use metallic current collectors, but nevertheless shows very good performance, including high specific capacitance ({approx}500 F g{sup -1}, including the current collector mass), reliable electrochemical stability (<4.5% degradation in 2500 cycles) and a very high rate capability (245 F g{sup -1} at 155 A g{sup -1}).

  11. Hierarchically Mesostructured Aluminum Current Collector for Enhancing the Performance of Supercapacitors.

    Science.gov (United States)

    Huang, Yilun; Li, Yuyao; Gong, Qianming; Zhao, Guanlei; Zheng, Pengjie; Bai, Junfei; Gan, Jianning; Zhao, Ming; Shao, Yang; Wang, Dazhi; Liu, Lei; Zou, Guisheng; Zhuang, Daming; Liang, Ji; Zhu, Hongwei; Nan, Cewen

    2018-05-16

    Aluminum (Al) current collector is one of the most important components of supercapacitors, and its performance has vital effects on the electrochemical performance and cyclic stability of supercapacitors. In the present work, a scalable and low-cost, yet highly efficient, picosecond laser processing method of Al current collectors was developed to improve the overall performance of supercapacitors. The laser treatment resulted in hierarchical micro-nanostructures on the surface of the commercial Al foil and reduced the surface oxygen content of the foil. The electrochemical performance of the Al foil with the micro-nanosurface structures was examined in the symmetrical activated carbon-based coin supercapacitors with an organic electrolyte. The results suggest that the laser-treated Al foil (laser-Al) increased the capacitance density of supercapacitors up to 110.1 F g -1 and promoted the rate capability due to its low contact resistance with the carbonaceous electrode and high electrical conductivity derived from its larger specific surface areas and deoxidized surface. In addition, the capacitor with the laser-Al current collector exhibited high cyclic stability with 91.5% capacitance retention after 10 000 cycles, 21.3% higher than that with pristine-Al current collector due to its stronger bonding with the carbonaceous electrode that prevented any delamination during aging. Our work has provided a new strategy for improving the electrochemical performance of supercapacitors.

  12. Embedded Ag Grid Electrodes as Current Collector for Ultraflexible Transparent Solid-State Supercapacitor.

    Science.gov (United States)

    Xu, Jian-Long; Liu, Yan-Hua; Gao, Xu; Sun, Yilin; Shen, Su; Cai, Xinlei; Chen, Linsen; Wang, Sui-Dong

    2017-08-23

    Flexible transparent solid-state supercapacitors have attracted immerse attention for the power supply of next-generation flexible "see-through" or "invisible" electronics. For fabrication of such devices, high-performance flexible transparent current collectors are highly desired. In this paper, the utilization of embedded Ag grid transparent conductive electrodes (TCEs) fabricated by a facile soft ultraviolet imprinting lithography method combined with scrap techniques, as the current collector for flexible transparent solid-state supercapacitors, is demonstrated. The embedded Ag grid TCEs exhibit not only excellent optoelectronic properties (R S ∼ 2.0 Ω sq -1 and T ∼ 89.74%) but also robust mechanical properties, which could meet the conductivity, transparency, and flexibility needs of current collectors for flexible transparent supercapacitors. The obtained supercapacitor exhibits large specific capacitance, long cycling life, high optical transparency (T ∼ 80.58% at 550 nm), high flexibility, and high stability. Owing to the embedded Ag grid TCE structure, the device shows a slight capacitance loss of 2.6% even after 1000 cycles of repetitive bending for a bending radius of up to 2.0 mm. This paves the way for developing high-performance current collectors and thus flexible transparent energy storage devices, and their general applicability opens up opportunities for flexible transparent electronics.

  13. Assessment of the flotability of chalcopyrite, molybdenite and pyrite using biosolids and their main components as collectors for greening the froth flotation of copper sulphide ores.

    OpenAIRE

    Sobarzo, Francisco; Herrera Urbina, Ronaldo; Higueras Higueras, Pablo Leon; Sáez Navarrete, César; Godoy Faúndez, Alex; Reyes Bozo, Lorenzo; Vásquez Bestagno, Jorge

    2014-01-01

    Biosolids and representative compounds of their main components ? humic acids, sugars, and proteins ? have been tested as possible environment-friendly collectors and frothers for the flotation of copper sulphide ores. The floatability of chalcopyrite and molybdenite ? both valuable sulphide minerals present in these ores ? as well as non-valuable pyrite was assessed through Hallimond tube flotation tests. Humic acids exhibit similar collector ability for chalcopyrite and molybdenite as that ...

  14. Low cost bipolar current collector-separator for electrochemical cells

    International Nuclear Information System (INIS)

    Lawrence, R.

    1980-01-01

    A bipolar current collecting, cell separating element for electrochemical cells for conducting current from the anode electrode of one cell unit to cathode electrode of the adjacent cell unit comprises: (A) a pressure mold aggregate of electrically conductive carbon/graphite particles and thermoplastic fluorocarbon polymer resin particles in a weight ratio of 2.5:1 to 16:1 whereby said molded aggregated has a bulk resistivity which is less than 4x10 -3 ohm/inch, (B) said molded aggregate having a fluid imprevious main body, at least one recessed chamber on one side of said main body and a plurality of spaced, conductive projections extending from the base of said chamber for contacting and permitting current flow between the electrode of adjacent cell unit, and (C) means communicating with said recessed chambers to permit introduction and removal of fluids

  15. Effect of notch depth of modified current collector on internal-short-circuit mitigation for lithium-ion battery

    Science.gov (United States)

    Wang, Meng; Noelle, Daniel J.; Shi, Yang; Le, Anh V.; Qiao, Yu

    2018-01-01

    Formation of internal short circuit (ISC) may result in catastrophic thermal runaway of lithium-ion battery (LIB). Among LIB cell components, direct contact between cathode and anode current collectors is most critical to the ISC behavior, yet is still relatively uninvestigated. In the current study, we analyze the effect of heterogeneity of current collector on the temperature increase of LIB cells subjected to mechanical abuse. The cathode current collector is modified by surface notches, so that it becomes effectively brittle and the ISC site can be isolated. Results from impact tests on LIB cells with modified current collectors suggest that their temperature increase can be negligible. The critical parameters include the failure strain and the failure work of modified current collector, both of which are related to the notch depth.

  16. Current trends in copper theft prevention

    Energy Technology Data Exchange (ETDEWEB)

    Mastrofrancesco, A. [Electrical Safety Authority, ON (Canada)

    2009-07-01

    Copper is used in electrical wiring, water and gas piping, currency, and in household items. An increase in the price and demand for copper has made copper theft a profitable venture for some thieves. Copper consumed in North America is typically supplied by recycling. Scrap dealers may pay near-market prices for pure copper wires. However, copper theft poses a serious threat to the safety of utility workers and the public. Power outages caused by copper theft are now affecting grid reliability. This paper examined technologies and techniques used to prevent copper theft as part of a security strategy for utilities. Attempts to steal copper can leave utility substations unsecured and accessible to children. The theft of neutral grounds will cause the local distribution company (LDC) to malfunction and may cause power surges in homes as well as appliance fires. Utilities are now looking at using a hybrid steel and copper alternative to prevent copper theft. Asset identification techniques are also being used to identify the original owners of the copper and more easily prosecute thieves. Automated monitoring techniques are also being used to increase substation security. Utilities are also partnering with law enforcement agencies and pressuring governments to require scrap dealers to record who they buy from. It was concluded that strategies to prevent copper theft should be considered as part of an overall security strategy for utilities. tabs., figs.

  17. The influence of current collector corrosion on the performance of electrochemical capacitors

    Science.gov (United States)

    Wojciechowski, Jarosław; Kolanowski, Łukasz; Bund, Andreas; Lota, Grzegorz

    2017-11-01

    This paper discusses the effect of current collector (stainless steel 316L) corrosion on the performance of electrochemical capacitors operated in aqueous electrolytes. This topic seems to be often neglected in scientific research. The studied electrolytes were 1 M H2SO4, 1 M KI, 1 M Na2SO4, 1 M KOH and 6 M KOH. The corrosion process was investigated by means of selected direct and alternating current techniques. The surface of the current collectors as well as the corrosion products were characterised using scanning electron microscopy, energy-dispersive X-ray spectroscopy, Raman spectroscopy and atomic force microscopy. Stainless steel 316L in alkaline solutions is characterised by the lowest values of corrosion potentials whereas the potentials in acidic media become the most noble. Our studies show that corrosion potentials increase with decreasing pH value. This phenomenon can be explained with the formation of passive oxide films on the stainless steel current collectors. The passive oxide films are usually thicker and more porous in alkaline solutions than that in the other electrolytes. The processes occurring at the electrode/electrolyte interfaces strongly influence the working parameters of electrochemical capacitors such as voltage, working potentials of single electrodes, self-discharge as well as the internal resistance and cycling stability.

  18. Revisiting the Corrosion of the Aluminum Current Collector in Lithium-Ion Batteries.

    Science.gov (United States)

    Ma, Tianyuan; Xu, Gui-Liang; Li, Yan; Wang, Li; He, Xiangming; Zheng, Jianming; Liu, Jun; Engelhard, Mark H; Zapol, Peter; Curtiss, Larry A; Jorne, Jacob; Amine, Khalil; Chen, Zonghai

    2017-03-02

    The corrosion of aluminum current collectors and the oxidation of solvents at a relatively high potential have been widely investigated with an aim to stabilize the electrochemical performance of lithium-ion batteries using such components. The corrosion behavior of aluminum current collectors was revisited using a home-build high-precision electrochemical measurement system, and the impact of electrolyte components and the surface protection layer on aluminum foil was systematically studied. The electrochemical results showed that the corrosion of aluminum foil was triggered by the electrochemical oxidation of solvent molecules, like ethylene carbonate, at a relative high potential. The organic radical cations generated from the electrochemical oxidation are energetically unstable and readily undergo a deprotonation reaction that generates protons and promotes the dissolution of Al 3+ from the aluminum foil. This new reaction mechanism can also shed light on the dissolution of transitional metal at high potentials.

  19. An electro-thermal model and its application on a spiral-wound lithium ion battery with porous current collectors

    International Nuclear Information System (INIS)

    Ye, Yonghuang; Shi, Yixiang; Saw, Lip Huat; Tay, Andrew A.O.

    2014-01-01

    Highlights: • A local electro-thermal model is developed to verify the validity of a lump electro-thermal model. • Comparisons on edge effect of batteries with porous current collectors and batteries normal current collector foil. • Investigation on thermal performance of novel battery with porous current collector sheets. - Abstract: A local electro-thermal model for a spiral-wound lithium ion battery is developed to provide detailed and local insights of electrochemistry, transport phenomenon and heat transfer processes in spiral-wound geometries. The discharging potential, bulk heat generation rate, battery surface temperature and the temperature distribution within battery predicted by the model are used to verify a lumped electro-thermal model. The results show good agreement between the lumped electro-thermal model and the local electro-thermal model. The edge effect is investigated using the local electro-thermal model. And the results indicate that a novel battery with porous current collector sheets has a higher utilization rate of porous electrode materials than a commercial battery with normal current collector foils. The novel battery with porous current collector sheets is also investigated using the local electro-thermal model, simulation results show smaller liquid phase potential gradient and smaller liquid concentration gradient in the novel battery. The increased electrical resistance has minor effect on the overall heat generation within the battery when the porous current collector is employed, while it reduces the discharging potential of the battery

  20. Actively controlled current collector; Aktiv geregelter Stromabnehmer. Innovation fuer den schnellen Verkehr auf konventionellen Strecken

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, C.

    2003-07-01

    Deutsche Bahn is presently endeavouring to further improve the interaction between the overhead wire and the current collectors on its locomotives and trainsets. The major factors behind this initiative are cost, quality and noise prevention. The outcome is the development of a completely new type of current collector for high-speed operation even on conventional track. Prototypes have meanwhile undergone practical trials on the 200 km/h line from Augsburg to Donauwoerth. The new current collector is a single-arm pantograph jointly developed by DB and Bombardier Transportation. (orig.) [German] Die Deutsche Bahn versucht derzeit, das Zusammenspiel von Oberleitung und den Stromabnehmern ihrer Lokomotiven und Triebzuege weiter zu verbessern. Kosten, Qualitaet und Laermschutz sind dabei die wesentlichen Gruende. Sie haben zur Entwicklung eines voellig neuen Stromabnehmer-Typus speziell fuer den Hochgeschwindigkeitsverkehr auch auf konventionellen Strecken gefuehrt. Auf der Tempo-200-Strecke von Augsburg nach Donauwoerth absolvierten jetzt Prototypen erste Praxis-Tests. Es handelt sich um aktiv geregelte, akustisch optimierte Einholmstromabnehmer, gemeinsam entwickelt von DB und Bombardier Transportation. (orig.)

  1. Theoretical model of gravitational perturbation of current collector axisymmetric flow field

    Science.gov (United States)

    Walker, John S.; Brown, Samuel H.; Sondergaard, Neal A.

    1990-05-01

    Some designs of liquid-metal current collectors in homopolar motors and generators are essentially rotating liquid-metal fluids in cylindrical channels with free surfaces and will, at critical rotational speeds, become unstable. An investigation at David Taylor Research Center is being performed to understand the role of gravity in modifying this ejection instability. Some gravitational effects can be theoretically treated by perturbation techniques on the axisymmetric base flow of the liquid metal. This leads to a modification of previously calculated critical-current-collector ejection values neglecting gravity effects. The purpose of this paper is to document the derivation of the mathematical model which determines the perturbation of the liquid-metal base flow due to gravitational effects. Since gravity is a small force compared with the centrifugal effects, the base flow solutions can be expanded in inverse powers of the Froude number and modified liquid-flow profiles can be determined as a function of the azimuthal angle. This model will be used in later work to theoretically study the effects of gravity on the ejection point of the current collector.

  2. Electroplated reticulated vitreous carbon current collectors for lead-acid batteries: opportunities and challenges

    Science.gov (United States)

    Gyenge, Elod; Jung, Joey; Mahato, Basanta

    Reticulated, open-cell structures based on vitreous carbon substrates electroplated with a Pb-Sn (1 wt.%) alloy were investigated as current collectors for lead-acid batteries. Scanning and backscattered electron microscopy, cyclic voltammetry, anodic polarization and flooded 2 V single-cell battery testing was employed to characterize the performance of the proposed collectors. A battery equipped with pasted electroplated reticulated vitreous carbon (RVC) electrodes of 137 cm 2 geometric area, at the time of manuscript submission, completed 500 cycles and over 1500 h of continuous operation. The cycling involved discharges at 63 A kg PAM-1 corresponding to a nominal 0.75 h rate and a positive active mass (PAM) utilization efficiency of 21%. The charging protocol was composed of two voltage limited (i.e. 2.6 V/cell), constant current steps of 35 and 9.5 A kg PAM-1, respectively, with a total duration of about 2 h. The charge factor was 1.05-1.15. The observed cycling behavior in conjunction with the versatility of electrodeposition to produce application-dependent optimized lead alloy coating thickness and composition shows promise for the development of lead-acid batteries using electroplated reticulated vitreous carbon collectors.

  3. STUDIES OF ACTIVATION OF GALENA BY COPPER AND XANTHATE (PIPX SYNTHESIZED COLLECTORS ADSORPTION

    Directory of Open Access Journals (Sweden)

    Z. NEDJAR

    2015-07-01

    Full Text Available In this study, we suggest proceeding to an experimental study concerning the synthesis of new organo metallic product xanthate (PIPX by intermittent method and their use in the processes of sulphides flotation. Flotation of sulphide minerals and their activation and modification have been investigated for many years. In this work the influence of sulphite on xanthate-induced flotation of copper-activated galena has been studied been investigated. The adsorption of potassium isopropyl xanthate (PIPX 3⋅10-3M on galena has been also studied using electrochemical potential, FTIR spectra and SEM. Galena activated with copper sulfate (10-4 M have been investigated at pH = 9. Surface species have been identified and correlated with SEM. After copper sulfate activation, copper xanthate exists on all of the minerals studied. Basic pH is most favorable for potassium isopropyl xanthate adsorption on activated minerals.

  4. Sputtering of sub-micrometer aluminum layers as compact, high-performance, light-weight current collector for supercapacitors

    Science.gov (United States)

    Busom, J.; Schreiber, A.; Tolosa, A.; Jäckel, N.; Grobelsek, I.; Peter, N. J.; Presser, V.

    2016-10-01

    Supercapacitors are devices for rapid and efficient electrochemical energy storage and commonly employ carbon coated aluminum foil as the current collector. However, the thickness of the metallic foil and the corresponding added mass lower the specific and volumetric performance on a device level. A promising approach to drastically reduce the mass and volume of the current collector is to directly sputter aluminum on the freestanding electrode instead of adding a metal foil. Our work explores the limitations and performance perspectives of direct sputter coating of aluminum onto carbon film electrodes. The tight and interdigitated interface between the metallic film and the carbon electrode enables high power handling, exceeding the performance and stability of a state-of-the-art carbon coated aluminum foil current collector. In particular, we find an enhancement of 300% in specific power and 186% in specific energy when comparing aluminum sputter coated electrodes with conventional electrodes with Al current collectors.

  5. Metal current collector-free freestanding silicon–carbon 1D nanocomposites for ultralight anodes in lithium ion batteries

    KAUST Repository

    Choi, Jang Wook; Hu, Liangbing; Cui, Lifeng; McDonough, James R.; Cui, Yi

    2010-01-01

    Although current collectors take up more weight than active materials in most lithium ion battery cells, so far research has been focused mainly on improving gravimetric capacities of active materials. To address this issue of improving gravimetric

  6. The use of alloy 117 as a liquid metal current collector

    Science.gov (United States)

    Maribo, David; Sondergaard, Neal

    1987-09-01

    Low melting point, bismuth based alloys are potential replacements for NaK78 as liquid metal slip ring material because of their lower reactivity and potentially greater hydrodynamic stability. This paper describes experiments with one such alloy in a model of a 300 kW superconducting homopolar motor using close clearance braid type collectors. Slip ring tip velocities varied from 5 to 20 m/s and currents ranging from 500 to 2000 A. Viscous power losses tend to follow a simple turbulent mode. In all, the data supports the use of low melting point alloys as an alternative to Na78.

  7. Nanoarchitectured current collector for high rate capability of polyaniline based supercapacitor electrode

    International Nuclear Information System (INIS)

    Sumboja, Afriyanti; Wang Xu; Yan Jian; Lee, Pooi See

    2012-01-01

    Highlights: ► Preparation of organic/inorganic coaxial nanowires. ► Modifying current collector to improve both capacitance and rate capability simultaneously. ► Improvement in the charge transport process resulted in the superior rate capability. - Abstract: Indium tin oxide (ITO) nanowires array was used as current collector and building block for polyaniline based supercapacitor. Thin polyaniline coating was deposited on the nanowires and resulted in the formation of polyaniline ITO coaxial nanowires. This hybrid heterostructure design improved the specific capacitance, rate capability, and cycling stability of the supercapacitor electrode. Good conductivity harnessed by these directly grown ITO nanowires is useful to improve the charge transport during the charge discharge processes which were confirmed by the electrochemical impedance spectroscopy measurement. Electrochemical test in 1 M H 2 SO 4 at 4 A g −1 delivered specific capacitance as high as 738 F g −1 . In addition, sub-micron size of the intercoaxial nanowires spacing ensures the fast penetration of electrolyte ions which resulted in the superior rate capability (98% capacitance retention when applied current was varied from 4 to 25 A g −1 ). The capacitance retention is significantly higher as compared to other polyaniline composite electrodes and it is one of the best reported performances to date for polyaniline based supercapacitor electrodes. This work illustrates a promising platform that can be adopted for other redox nanocomposite materials while reaping the benefit as low cost and binder free electrode material for supercapacitor application.

  8. Effects of momentum transfer on sizing of current collectors for lithium-ion batteries during laser cutting

    Science.gov (United States)

    Lee, Dongkyoung; Mazumder, Jyotirmoy

    2018-02-01

    One of the challenges of the lithium-ion battery manufacturing process is the sizing of electrodes with good cut surface quality. Poor cut surface quality results in internal short circuits in the cells and significant heat generation. One of the solutions that may improve the cut quality with a high cutting speed is laser cutting due to its high energy concentration, fast processing time, high precision, small heat affected zone, flexible range of laser power and contact free process. In order to utilize the advantages of laser electrode cutting, understanding the physical phenomena for each material is crucial. Thus, this study focuses on the laser cutting of current collectors, such as pure copper and aluminum. A 3D self-consistent mathematical model for the laser cutting, including fluid flow, heat transfer, recoil pressure, multiple reflections, capillary and thermo-capillary forces, and phase changes, is presented and solved numerically. Simulation results for the laser cutting are analyzed in terms of penetration time, depth, width, and absorptivity, based on these selected laser parameters. In addition, melt pool flow, melt pool geometry and temperature distribution are investigated.

  9. Graphene-based supercapacitor with carbon nanotube film as highly efficient current collector

    International Nuclear Information System (INIS)

    Notarianni, Marco; Liu, Jinzhang; Motta, Nunzio; Mirri, Francesca; Pasquali, Matteo

    2014-01-01

    Flexible graphene-based thin film supercapacitors were made using carbon nanotube (CNT) films as current collectors and graphene films as electrodes. The graphene sheets were produced by simple electrochemical exfoliation, while the graphene films with controlled thickness were prepared by vacuum filtration. The solid-state supercapacitor was made by using two graphene/CNT films on plastic substrates to sandwich a thin layer of gelled electrolyte. We found that the thin graphene film with thickness <1 μm can greatly increase the capacitance. Using only CNT films as electrodes, the device exhibited a capacitance as low as ∼0.4 mF cm −2 , whereas by adding a 360 nm thick graphene film to the CNT electrodes led to a ∼4.3 mF cm −2 capacitance. We experimentally demonstrated that the conductive CNT film is equivalent to gold as a current collector while it provides a stronger binding force to the graphene film. Combining the high capacitance of the thin graphene film and the high conductivity of the CNT film, our devices exhibited high energy density (8–14 Wh kg −1 ) and power density (250–450 kW kg −1 ). (paper)

  10. Performance-Enhanced Activated Carbon Electrodes for Supercapacitors Combining Both Graphene-Modified Current Collectors and Graphene Conductive Additive.

    Science.gov (United States)

    Wang, Rubing; Qian, Yuting; Li, Weiwei; Zhu, Shoupu; Liu, Fengkui; Guo, Yufen; Chen, Mingliang; Li, Qi; Liu, Liwei

    2018-05-15

    Graphene has been widely used in the active material, conductive agent, binder or current collector for supercapacitors, due to its large specific surface area, high conductivity, and electron mobility. However, works simultaneously employing graphene as conductive agent and current collector were rarely reported. Here, we report improved activated carbon (AC) electrodes (AC@G@NiF/G) simultaneously combining chemical vapor deposition (CVD) graphene-modified nickel foams (NiF/Gs) current collectors and high quality few-layer graphene conductive additive instead of carbon black (CB). The synergistic effect of NiF/Gs and graphene additive makes the performances of AC@G@NiF/G electrodes superior to those of electrodes with CB or with nickel foam current collectors. The performances of AC@G@NiF/G electrodes show that for the few-layer graphene addition exists an optimum value around 5 wt %, rather than a larger addition of graphene, works out better. A symmetric supercapacitor assembled by AC@G@NiF/G electrodes exhibits excellent cycling stability. We attribute improved performances to graphene-enhanced conductivity of electrode materials and NiF/Gs with 3D graphene conductive network and lower oxidation, largely improving the electrical contact between active materials and current collectors.

  11. Performance-Enhanced Activated Carbon Electrodes for Supercapacitors Combining Both Graphene-Modified Current Collectors and Graphene Conductive Additive

    Science.gov (United States)

    Wang, Rubing; Qian, Yuting; Li, Weiwei; Zhu, Shoupu; Liu, Fengkui; Guo, Yufen; Chen, Mingliang; Li, Qi; Liu, Liwei

    2018-01-01

    Graphene has been widely used in the active material, conductive agent, binder or current collector for supercapacitors, due to its large specific surface area, high conductivity, and electron mobility. However, works simultaneously employing graphene as conductive agent and current collector were rarely reported. Here, we report improved activated carbon (AC) electrodes (AC@G@NiF/G) simultaneously combining chemical vapor deposition (CVD) graphene-modified nickel foams (NiF/Gs) current collectors and high quality few-layer graphene conductive additive instead of carbon black (CB). The synergistic effect of NiF/Gs and graphene additive makes the performances of AC@G@NiF/G electrodes superior to those of electrodes with CB or with nickel foam current collectors. The performances of AC@G@NiF/G electrodes show that for the few-layer graphene addition exists an optimum value around 5 wt %, rather than a larger addition of graphene, works out better. A symmetric supercapacitor assembled by AC@G@NiF/G electrodes exhibits excellent cycling stability. We attribute improved performances to graphene-enhanced conductivity of electrode materials and NiF/Gs with 3D graphene conductive network and lower oxidation, largely improving the electrical contact between active materials and current collectors. PMID:29762528

  12. Thin and flexible Ni-P based current collectors developed by electroless deposition for energy storage devices

    International Nuclear Information System (INIS)

    Wu, Haoran; Susanto, Amelia; Lian, Keryn

    2017-01-01

    Highlights: • A PET metallized by electroless nickel was developed as flexible current collector. • The Ni-PET current collector showed good conductivity and chemical stability. • The flexible nanocarbon electrodes with Ni-PET exhibited capacitive behavior. • The Ni-PET enabled electrodes performed nicely in liquid and solid supercapacitors. - Abstract: A PET film metalized by electroless nickel deposition was demonstrated as thin and flexible current collector for energy storage devices. The resultant nickel-on-PET film (Ni-PET) can be used both as current collector for electrochemical capacitors and as electrode for thin film batteries. The composition of Ni-PET was characterized by EDX and XPS. The electrochemical performance of the Ni-PET current collector was similar to Ni foil but with less hydrogen evolution at low potential. The Ni-PET film exhibited better flexibility than a metallic Ni foil. Carbon nanotubes were coated on a Ni-PET substrate to form an electrochemical capacitor electrode which exhibited high chemical stability in both liquid and solid electrolytes, showing strong promise for solid energy storage devices.

  13. Thin and flexible Ni-P based current collectors developed by electroless deposition for energy storage devices

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Haoran, E-mail: haoran.wu@mail.utoronto.ca; Susanto, Amelia; Lian, Keryn

    2017-02-01

    Highlights: • A PET metallized by electroless nickel was developed as flexible current collector. • The Ni-PET current collector showed good conductivity and chemical stability. • The flexible nanocarbon electrodes with Ni-PET exhibited capacitive behavior. • The Ni-PET enabled electrodes performed nicely in liquid and solid supercapacitors. - Abstract: A PET film metalized by electroless nickel deposition was demonstrated as thin and flexible current collector for energy storage devices. The resultant nickel-on-PET film (Ni-PET) can be used both as current collector for electrochemical capacitors and as electrode for thin film batteries. The composition of Ni-PET was characterized by EDX and XPS. The electrochemical performance of the Ni-PET current collector was similar to Ni foil but with less hydrogen evolution at low potential. The Ni-PET film exhibited better flexibility than a metallic Ni foil. Carbon nanotubes were coated on a Ni-PET substrate to form an electrochemical capacitor electrode which exhibited high chemical stability in both liquid and solid electrolytes, showing strong promise for solid energy storage devices.

  14. Curious Case of Positive Current Collectors: Corrosion and Passivation at High Temperature.

    Science.gov (United States)

    Sayed, Farheen N; Rodrigues, Marco-Tulio F; Kalaga, Kaushik; Gullapalli, Hemtej; Ajayan, P M

    2017-12-20

    In the evaluation of compatibility of different components of cell for high-energy and extreme-conditions applications, the highly focused are positive and negative electrodes and their interaction with electrolyte. However, for high-temperature application, the other components are also of significant influence and contribute toward the total health of battery. In present study, we have investigated the behavior of aluminum, the most common current collector for positive electrode materials for its electrochemical and temperature stability. For electrochemical stability, different electrolytes, organic and room temperature ionic liquids with varying Li salts (LiTFSI, LiFSI), are investigated. The combination of electrochemical and spectroscopic investigations reflects the varying mechanism of passivation at room and high temperature, as different compositions of decomposed complexes are found at the surface of metals.

  15. Free-standing, well-aligned ordered mesoporous carbon nanofibers on current collectors for high-power micro-supercapacitors.

    Science.gov (United States)

    Kang, Eunae; Jeon, Gumhye; Kim, Jin Kon

    2013-07-21

    The mesoporous carbon nanofiber arrays that stand on carbon-gold double-layer current collectors are synthesized by self-assembly of a PS-b-PEO copolymer and resol in AAO templates for a high-power micro-supercapacitor at high current densities.

  16. Evidence of the Current Collector Effect: Study of the SOFC Cathode Material Ca3Co4O9+d

    NARCIS (Netherlands)

    Rolle, A.; Thoréton, V.; Rozier, P.; Capoen, E.; Mentré, O.; Boukamp, Bernard A.; Daviero-Minaud, S.

    2012-01-01

    In the study of the performance of solid oxide fuel cell (SOFC) electrodes, the possible influence of the applied current collector is often not mentioned or recognized. In this article, as part of an optimization study of the potentially attractive Ca3Co4O9+δ cathode material (Ca349), special

  17. Mesh optimization for microbial fuel cell cathodes constructed around stainless steel mesh current collectors

    KAUST Repository

    Zhang, Fang

    2011-02-01

    Mesh current collectors made of stainless steel (SS) can be integrated into microbial fuel cell (MFC) cathodes constructed of a reactive carbon black and Pt catalyst mixture and a poly(dimethylsiloxane) (PDMS) diffusion layer. It is shown here that the mesh properties of these cathodes can significantly affect performance. Cathodes made from the coarsest mesh (30-mesh) achieved the highest maximum power of 1616 ± 25 mW m-2 (normalized to cathode projected surface area; 47.1 ± 0.7 W m-3 based on liquid volume), while the finest mesh (120-mesh) had the lowest power density (599 ± 57 mW m-2). Electrochemical impedance spectroscopy showed that charge transfer and diffusion resistances decreased with increasing mesh opening size. In MFC tests, the cathode performance was primarily limited by reaction kinetics, and not mass transfer. Oxygen permeability increased with mesh opening size, accounting for the decreased diffusion resistance. At higher current densities, diffusion became a limiting factor, especially for fine mesh with low oxygen transfer coefficients. These results demonstrate the critical nature of the mesh size used for constructing MFC cathodes. © 2010 Elsevier B.V. All rights reserved.

  18. Current collector design for closed-plenum polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Daniels, F. A.; Attingre, C.; Kucernak, A. R.; Brett, D. J. L.

    2014-03-01

    This work presents a non-isothermal, single-phase, three-dimensional model of the effects of current collector geometry in a 5 cm2 closed-plenum polymer electrolyte membrane (PEM) fuel cell constructed using printed circuit boards (PCBs). Two geometries were considered in this study: parallel slot and circular hole designs. A computational fluid dynamics (CFD) package was used to account for species, momentum, charge and membrane water distribution within the cell for each design. The model shows that the cell can reach high current densities in the range of 0.8 A cm-2-1.2 A cm-2 at 0.45 V for both designs. The results indicate that the transport phenomena are significantly governed by the flow field plate design. A sensitivity analysis on the channel opening ratio shows that the parallel slot design with a 50% opening ratio shows the most promising performance due to better species, heat and charge distribution. Modelling and experimental analysis confirm that flooding inhibits performance, but the risk can be minimised by reducing the relative humidity of the cathode feed to 50%. Moreover, overheating is a potential problem due to the insulating effect of the PCB base layer and as such strategies should be implemented to combat its adverse effects.

  19. Silver Fiber Fabric as the Current Collector for Preparation of Graphene- Based Supercapacitors

    International Nuclear Information System (INIS)

    Mehrabi-Matin, Bahareh; Shahrokhian, Saeed; Iraji-zad, Azam

    2017-01-01

    Highlights: • For the first time, silver fiber fabric (SFF) is employed as a current collector.. • rGO is electrophoretically deposited on the surface of SFF. • The electrodes are prepared in various EP deposition times. • The rGO/SFF-10 shows a higher capacitive performance of 172 mF/cm 2 at 4 mA/cm 2 . • The rGO/SFF-10 exhibits of 97% capacitance retention after 5000 cycles. - Abstract: During the past few years, a considerable attention has been devoted to the development of textile- based energy storage devices and wearable electronics applications. In this paper, for the first time, we report a flexible high performance graphene-based supercapacitor using silver fiber fabric as the current collector. The silver fiber fabric offers remarkable advantages such as light weight, mechanical flexibility and ease of integration with electronic textiles, which well-suited for wearable energy storage devices. A new hybrid material of graphene-silver fiber fabric (rGO/SFF) was prepared through a facile electrophoretic deposition of graphene and being used as a binder-free flexible supercapacitor electrode. In order to obtain the optimum condition, the effect of deposition time was investigated and a duration time of 10 minute was selected as an optimum condition. The as-prepared binder-free electrode based on rGO/SFF-10 showed excellent electrochemical performance in the three-electrode configuration using KOH (3 M) as the supporting electrolyte, with the highest capacity of 172 mF/cm 2 at 4 mA/cm 2 and a capacitance retention of 97% after 5000 charge−discharge cycles. The high performance of rGO/SFF electrode is associated to the superior conductivity, high mechanical flexibility as well as good electrochemical stability of the silver fiber fabrics. The results suggest that the prepared electrode is a promising candidate for wearable energy storage applications due to its advantageous properties and the ease of preparation.

  20. Design and fabrication of light weight current collectors for direct methanol fuel cells using the micro-electro mechanical system technique

    Science.gov (United States)

    Sung, Min-Feng; Kuan, Yean-Der; Chen, Bing-Xian; Lee, Shi-Min

    The direct methanol fuel cell (DMFC) is suitable for portable applications. Therefore, a light weight and small size is desirable. The main objective of this paper is to design and fabricate a light weight current collector for DMFC usage. The light weight current collector mainly consists of a substrate with two thin film metal layers. The substrate of the current collector is an FR4 epoxy plate. The thin film metal layers are accomplished by the thermo coater technique to coat metal powders onto the substrate surfaces. The developed light weight current collectors are further assembled to a single cell DMFC test fixture to measure the cell performance. The results show that the proposed current collectors could even be applied to DMFCs because they are light, thin and low cost and have potential for mass production.

  1. Inhibition of anodic corrosion of aluminium cathode current collector on recharging in lithium imide electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xianming; Yasukawa, Eiki; Mori, Shoichiro [Tsukuba Research Center, Mitsubishi Chemical Corp., Ibaraki (Japan)

    2000-07-01

    Pitting corrosion of aluminum as cathode current collector for lithium rechargeable batteries was found to take place at potential positive of 3.5 V in 1 mol dm {sup -3} LiN(SO{sub 2}CF{sub 3}){sub 2} /EC + DME (1:1) electrolyte. The corrosion mechanism of aluminum in the presence of LiN(SO{sub 2}CF{sub 3}){sub 2} was proposed, and three methods were deduced to inhibit the aluminum corrosion based on this mechanism. As a result, an additive of lithium salts based on perfluorinated inorganic anions, especially LiPF{sub 6}, was found to inhibit the aluminum corrosion to a certain extent by forming a protective film on aluminum surface. The oxidation stability of aluminum in LiN(SO{sub 2}CF{sub 3}){sub 2} -containing electrolytes depended strongly on the solvent structure. The ether solvents such as tetrahydrofuran (THF) and dimethoxyethane (DME) were effective in preventing aluminum corrosion due to their low dielectric constants. Furthermore, LiN(SO{sub 2}C{sub 2}F{sub 5}){sub 2} salt with a larger anion than that of LiN(SO{sub 2}CF{sub 3}){sub 2} was evaluated and good oxidation stability of aluminum was obtained regardless of the kind of solvents. (Author)

  2. Hybrid Microsupercapacitors with Vertically Scaled 3D Current Collectors Fabricated using a Simple Cut-and-Transfer Strategy

    KAUST Repository

    Jiang, Qiu

    2016-09-08

    By employing 3D current collectors, hybrid coplanar microsupercapacitors are fabricated. These devices show excellent energy density of 200 μW h cm−2 compared to the state-of-the-art microsupercapacitors (1–40 μW h cm−2), and superior power density (4.4 mW cm−2) compared to thin film batteries and microbatteries at comparable energy density.

  3. Hybrid Microsupercapacitors with Vertically Scaled 3D Current Collectors Fabricated using a Simple Cut-and-Transfer Strategy

    KAUST Repository

    Jiang, Qiu; Kurra, Narendra; Xia, Chuan; Alshareef, Husam N.

    2016-01-01

    By employing 3D current collectors, hybrid coplanar microsupercapacitors are fabricated. These devices show excellent energy density of 200 μW h cm−2 compared to the state-of-the-art microsupercapacitors (1–40 μW h cm−2), and superior power density (4.4 mW cm−2) compared to thin film batteries and microbatteries at comparable energy density.

  4. 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.

  5. 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.

  6. Ni/Ni-YSZ current collector/anode dual layer hollow fibers for micro-tubular solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kanawka, K.; Othman, M.H.D.; Droushiotis, N.; Wu, Z.; Kelsall, G.; Li, K. [Department of Chemical Engineering and Chemical Technology, Imperial College London, London SW7 2AZ (United Kingdom)

    2011-10-15

    A co-extrusion technique was employed to fabricate a novel dual layer NiO/NiO-YSZ hollow fiber (HF) precursor which was then co-sintered at 1,400 C and reduced at 700 C to form, respectively, a meshed porous inner Ni current collector and outer Ni-YSZ anode layers for SOFC applications. The inner thin and highly porous ''mesh-like'' pure Ni layer of approximately 50 {mu}m in thickness functions as a current collector in micro-tubular solid oxide fuel cell (SOFC), aiming at highly efficient current collection with low fuel diffusion resistance, while the thicker outer Ni-YSZ layer of 260 {mu}m acts as an anode, providing also major mechanical strength to the dual-layer HF. Achieved morphology consisted of short finger-like voids originating from the inner lumen of the HF, and a sponge-like structure filling most of the Ni-YSZ anode layer, which is considered to be suitable macrostructure for anode SOFC system. The electrical conductivity of the meshed porous inner Ni layer is measured to be 77.5 x 10{sup 5} S m{sup -1}. This result is significantly higher than previous reported results on single layer Ni-YSZ HFs, which performs not only as a catalyst for the oxidation reaction, but also as a current collector. These results highlight the advantages of this novel dual-layer HF design as a new and highly efficient way of collecting current from the lumen of micro-tubular SOFC. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Standardized performance tests of collectors of solar thermal energy: A selectively coated, flat-plate copper collector with one transparent cover and a tube-to-tube spacing of 5 5/8 inches

    Science.gov (United States)

    1976-01-01

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

  8. Standard performance tests of collectors of solar thermal energy: A selectively coated, flat-plate copper collector with one transparent cover and a tube-to-tube spacing of 3-7/8 inches

    Science.gov (United States)

    1976-01-01

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

  9. Conductive polymer and Si nanoparticles composite secondary particles and structured current collectors for high loading lithium ion negative electrode application

    Science.gov (United States)

    Liu, Gao

    2017-07-11

    Embodiments of the present invention disclose a composition of matter comprising a silicon (Si) nanoparticle coated with a conductive polymer. Another embodiment discloses a method for preparing a composition of matter comprising a plurality of silicon (Si) nanoparticles coated with a conductive polymer comprising providing Si nanoparticles, providing a conductive polymer, preparing a Si nanoparticle, conductive polymer, and solvent slurry, spraying the slurry into a liquid medium that is a non-solvent of the conductive polymer, and precipitating the silicon (Si) nanoparticles coated with the conductive polymer. Another embodiment discloses an anode comprising a current collector, and a composition of matter comprising a silicon (Si) nanoparticle coated with a conductive polymer.

  10. 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 ...

  11. Research and analysis on electrochemical performances of α-Fe{sub 2}O{sub 3} electrode in Li-ion battery with different current collectors

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lihong, E-mail: huang.lihong@foxmail.com; Min, Zhonghua; Zhang, Qinyong

    2015-06-15

    Highlights: • We achieved a reversible capacity of 415 mAh g{sup −1} after 30 cycles for α-Fe{sub 2}O{sub 3} electrode in Li-ion battery. • Better electrical performance was obtained when using Cu foam as current collector. • As current collector for α-Fe{sub 2}O{sub 3} electrode, Cu foam is better than Cu foil and Ni foam. • It could avoid the active materials falling off from the current collector during cycling. • It is owe to smaller surface film resistance, charge-transfer resistance, etc. - Abstract: In this work, we reported a simple synthesis of submicron α-Fe{sub 2}O{sub 3} with rod-like structure. When it evaluated as electrode material for lithium ion battery, comparing with Cu foil and Ni foam, the as-prepared α-Fe{sub 2}O{sub 3} electrodes with Cu foam current collector exhibited higher reversible capacity of 415 mAh g{sup −1} and more stable cycle performance after 30 cycles. Comparative researches on electrochemical performances of the α-Fe{sub 2}O{sub 3} employing different current collectors (Cu foil, Cu foam and Ni foam) were discussed here in detail. According to our results, the improved electrochemical behaviors of α-Fe{sub 2}O{sub 3} electrode with Cu foam current collector could be attributed to its particular electrode structure, i.e., porous, good electric conductivity, closed adhere to the electrode materials. Just because of that, it may make sure an easy accessibility of electrolytes and fast transportation of lithium ions, importantly, it could avoid the active materials falling off from the current collector on account of volume expansion.

  12. Graphene-Armored Aluminum Foil with Enhanced Anticorrosion Performance as Current Collectors for Lithium-Ion Battery.

    Science.gov (United States)

    Wang, Mingzhan; Tang, Miao; Chen, Shulin; Ci, Haina; Wang, Kexin; Shi, Liurong; Lin, Li; Ren, Huaying; Shan, Jingyuan; Gao, Peng; Liu, Zhongfan; Peng, Hailin

    2017-12-01

    Aluminum (Al) foil, as the most accepted cathode current collector for lithium-ion batteries (LIBs), is susceptible to local anodic corrosions during long-term operations. Such corrosions could lead to the deterioration or even premature failure of the batteries and are generally believed to be a bottleneck for next-generation 5 V LIBs. Here, it is demonstrated that Al foil armored by conformal graphene coating exhibits significantly reinforced anodic corrosion resistance in both LiPF 6 and lithium bis(trifluoromethanesulphonyl) imide (LiTFSI) based electrolytes. Moreover, LiMn 2 O 4 cells using graphene-armored Al foil as current collectors (LMO/GA) demonstrate enhanced electrochemical performance in comparison with those using pristine Al foil (LMO/PA). The long-term discharge capacity retention of LMO/GA cell after ≈950 h straight operations at low rate (0.5 C) reaches up to 91%, remarkably superior to LMO/PA cell (75%). The self-discharge propensity of LMO/GA is clearly relieved and the rate/power performance is also improved with graphene mediations. This work not only contributes to the long-term stable operations of LIBs but also might catalyze the deployment of 5 V LIBs in the future. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Metal current collector-free freestanding silicon–carbon 1D nanocomposites for ultralight anodes in lithium ion batteries

    KAUST Repository

    Choi, Jang Wook

    2010-12-15

    Although current collectors take up more weight than active materials in most lithium ion battery cells, so far research has been focused mainly on improving gravimetric capacities of active materials. To address this issue of improving gravimetric capacities based on overall cell components, we develop freestanding nanocomposites made of carbon nanofibers (CNFs) and silicon nanowires (SiNWs) as metal current collector-free anode platforms. Intrinsically large capacities of SiNWs as active materials in conjunction with the light nature of freestanding CNF films allow the nanocomposites to achieve 3-5 times improved gravimetric capacities compared to what have been reported in the literature. Moreover, three-dimensional porous structures in the CNF films facilitate increased mass loadings of SiNWs when compared to flat substrates and result in good cycle lives over 40 cycles. This type of nanocomposite cell suggests that 3D porous platforms consisting of light nanomaterials can provide for higher gravimetric and areal capacities when compared to conventional battery cells based on flat, heavy metal substrates. © 2010 Elsevier B.V. All rights reserved.

  14. Comparison and analysis of the efficiency of heat exchange of copper rod and copper wires current lead

    International Nuclear Information System (INIS)

    Fang, J.; Yu, T.; Li, Z.M.; Wei, B.; Qiu, M.; Zhang, H.J.

    2013-01-01

    Highlights: •An optimized design of HTS binary current leads is proposed. •Temperature distributions of two different current leads are calculated. •Experiments are done to certify the calculated temperature distributions. •The experiments proved that the copper wires increase security margins. -- Abstract: Current leads are the key components that connect the low-temperature and high temperature parts of the cryogenic system. Owing to the wide range of temperatures, current leads are the main sources of heat leakage. Since the HTS tapes have no resistance and the generated Joule heat is almost zero, HTS binary current leads can reduce heat leakage compared to the conventional leads. However, heat will still be generated and conducted to the cryogenic system through the copper parts of the HTS current leads. In order to reduce heat leakage by the copper parts of the HTS current leads, this paper presents an optimized design of the copper parts of HTS binary current leads. Inside the leads, the copper wires were applied as an alternative to the copper rod without changing the overall dimensions. Firstly, the differential function of heat transfer was derived. By solving the function, the optimum number of the copper wires and the temperature distribution of two different current leads were gotten. Then the experiment of the temperature distribution was done, and the experimental results were basically the same with the calculative results. The simulation and related experiments proved that the copper wire can increase security margins and reduce maximum temperatures under the same shunt current

  15. Comparison and analysis of the efficiency of heat exchange of copper rod and copper wires current lead

    Energy Technology Data Exchange (ETDEWEB)

    Fang, J., E-mail: fangseer@sina.com [School of Electrical Engineering, Beijing Jiaotong University, Beijing (China); Yu, T. [School of Electrical Engineering, Beijing Jiaotong University, Beijing (China); Li, Z.M.; Wei, B.; Qiu, M.; Zhang, H.J. [China Electric Power Research Institute, Haidian District, Beijing (China)

    2013-11-15

    Highlights: •An optimized design of HTS binary current leads is proposed. •Temperature distributions of two different current leads are calculated. •Experiments are done to certify the calculated temperature distributions. •The experiments proved that the copper wires increase security margins. -- Abstract: Current leads are the key components that connect the low-temperature and high temperature parts of the cryogenic system. Owing to the wide range of temperatures, current leads are the main sources of heat leakage. Since the HTS tapes have no resistance and the generated Joule heat is almost zero, HTS binary current leads can reduce heat leakage compared to the conventional leads. However, heat will still be generated and conducted to the cryogenic system through the copper parts of the HTS current leads. In order to reduce heat leakage by the copper parts of the HTS current leads, this paper presents an optimized design of the copper parts of HTS binary current leads. Inside the leads, the copper wires were applied as an alternative to the copper rod without changing the overall dimensions. Firstly, the differential function of heat transfer was derived. By solving the function, the optimum number of the copper wires and the temperature distribution of two different current leads were gotten. Then the experiment of the temperature distribution was done, and the experimental results were basically the same with the calculative results. The simulation and related experiments proved that the copper wire can increase security margins and reduce maximum temperatures under the same shunt current.

  16. Silver nanowires as the current collector for a flexible in-plane micro-supercapacitor via a one-step, mask-free patterning strategy

    Science.gov (United States)

    Liu, Lang; Li, Han-Yu; Yu, Yao; Liu, Lin; Wu, Yue

    2018-02-01

    The fabrication of a current collector-contained in-plane micro-supercapacitor (MSC) usually requires the patterning of the current collector first and then subsequent patterning of the active material with the assistance of a photoresist and mask. However, this two-step patterning process is too complicated and the photoresist used is harmful to the properties of nanomaterials. Here, we demonstrate a one-step, mask-free strategy to pattern the current collector and the active material at the same time, for the fabrication of an all-solid-state flexible in-plane MSC. Silver nanowires (AgNWs) are used as the current collector. An atmospheric pressure pulsed cold micro-plasma-jet is used to realize the one-step, mask-free production of interdigitated multi-walled carbon nanotube (MWCNT)/AgNW electrodes. Remarkably, the fabricated MWCNT/AgNW-based MSC shows good flexibility and excellent rate capability. Moreover, the performance of properties including cyclic stability, equivalent series resistance, relaxation time and energy/power densities of the MWCNT/AgNW-based MSC are significantly enhanced by the presence of the AgNW current collector.

  17. Optical Properties and Electrochemical Performance of LiFePO4 Thin Films Deposited on Transparent Current Collectors.

    Science.gov (United States)

    Lee, HyunSeok; Yim, Haena; Kim, Kwang-Bum; Choi, Ji-Won

    2015-11-01

    LiFePO4 thin film cathodes are deposited on various transparent conducting oxide thin films on glass, which are used as cathode current collectors. The XRD patterns show that the thin films have the phase of LiFePO4 with an ordered olivine structure indexed to the orthorhombic Pmna space group. LiFePO4 thin film deposited on various TCO glass substrates exhibits transmittance of about 53%. The initial specific discharge capacities of LiFePO4 thin films are 25.0 μAh/cm2 x μm on FTO, 33.0 μAh/cm2 x μm on ITO, and 13.0 μAh/cm2 x μm on AZO coated glass substrates. Interestingly, the retention capacities of LiFePO4 thin films are 76.0% on FTO, 31.2% on ITO, and 37.7% on AZO coated glass substrates at 20th cycle. The initial specific discharge capacity of the LiFePO4/FTO electrode is slightly lower, but the discharge capacities of the LiFePO4/FTO electrode relatively decrease less than those of the others such as LiFePO4/ITO and LiFePO4/AZO with cycling. The results reported here provide the high transparency of LiFePO4 thin films cathode materials and the good candidate as FTO current collector of the LiFePO4 thin film cathode of transparent thin film rechargeable batteries due to its high transparency and cyclic retention.

  18. "Water-in-salt" electrolytes enable the use of cost-effective aluminum current collectors for aqueous high-voltage batteries.

    Science.gov (United States)

    Kühnel, R-S; Reber, D; Remhof, A; Figi, R; Bleiner, D; Battaglia, C

    2016-08-16

    The extended electrochemical stability window offered by highly concentrated electrolytes allows the operation of aqueous batteries at voltages significantly above the thermodynamic stability limit of water, at which the stability of the current collector potentially limits the cell voltage. Here we report the observation of suppressed anodic dissolution of aluminum in "water-in-salt" electrolytes enabling roll-to-roll electrode fabrication for high-voltage aqueous lithium-ion batteries on cost-effective light-weight aluminum current collectors using established lithium-ion battery technology.

  19. Improvement of automatic control system for high-speed current collectors

    Science.gov (United States)

    Sidorov, O. A.; Goryunov, V. N.; Golubkov, A. S.

    2018-01-01

    The article considers the ways of regulation of pantographs to provide quality and reliability of current collection at high speeds. To assess impact of regulation was proposed integral criterion of the quality of current collection, taking into account efficiency and reliability of operation of the pantograph. The study was carried out using mathematical model of interaction of pantograph and catenary system, allowing to assess contact force and intensity of arcing at the contact zone at different movement speeds. The simulation results allowed us to estimate the efficiency of different methods of regulation of pantographs and determine the best option.

  20. Influence of electric current intensity on the performance of electroformed copper liner for shaped charge application

    Directory of Open Access Journals (Sweden)

    Tamer Elshenawy

    2017-12-01

    Full Text Available Electrolytic Copper used in the shaped charge liner manufacturing can be produced from acid solution using electro-deposition technique. The intensity of the applied electric current controls the quality of the produced copper grade. The electric current intensity within the electrolytic acidic solution cell with the minimum oxygen and sulfur elements in the produced copper was optimized and found to be 30–40 A/Ft2. The elemental composition of the obtained electrolytic copper was determined using high-end stationary vacuum spectrometer, while the oxygen was determined precisely using ELTRA ONH-2000 apparatus. Besides, SEM was used to investigate the shape of the copper texture inside the deposited layers and to determine the average grain size. New relations have been obtained between the applied current intensity and both the oxygen and sulfur contents and the average grain size of the produced copper. Experimental result showed that when the applied current density increases to a certain limit, the oxygen and sulfur content in the electrolytic copper decreases. Performance of the produced copper liner was investigated by the static firing of a small caliber shaped charge containing an electro-formed copper liners, where the penetration depth of the optimized electrolytic liner was enhanced by 22.7% compared to that of baseline non-optimized liner.

  1. NiCo2O4 nanosheets in-situ grown on three dimensional porous Ni film current collectors as integrated electrodes for high-performance supercapacitors

    Science.gov (United States)

    Wang, Tao; Guo, Ying; Zhao, Bo; Yu, Shuhui; Yang, Hai-Peng; Lu, Daniel; Fu, Xian-Zhu; Sun, Rong; Wong, Ching-Ping

    2015-07-01

    Three dimensional interconnected hierarchical porous Ni films are easily fabricated as effective current collectors through hydrogen bubble template electrochemical deposition. The binder-free integrated electrodes of spinel NiCo2O4 nanosheets directly coated the three dimensional porous Ni films are facilely obtained through successively electrochemical co-deposition of Ni/Co alloy layer then followed by subsequent annealing at 350 °C in air. Compared with NiCo2O4 nanosheets on smooth Ni foil or porous NiO/Ni film electrodes, the porous NiCo2O4/Ni integrated film electrodes for supercapacitors demonstrate remarkably higher area specific capacitance. The porous NiCo2O4/Ni film electrodes also exhibit excellent rate capability and cycling stability. The super electrochemical capacitive performances are attributed to the unique integrated architecture of NiCo2O4 nanosheets in-situ grown on three dimensional continuous hierarchical porous Ni collector collectors, which could provide large electrode-electrolyte interface area, high active sites, low contact resistance between current collector and active materials, fast electron conduction and ion/electrolyte diffusion.

  2. A 3.5 V lithium-iodine hybrid redox battery with vertically aligned carbon nanotube current collector.

    Science.gov (United States)

    Zhao, Yu; Hong, Misun; Bonnet Mercier, Nadège; Yu, Guihua; Choi, Hee Cheul; Byon, Hye Ryung

    2014-02-12

    A lithium-iodine (Li-I2) cell using the triiodide/iodide (I3(-)/I(-)) redox couple in an aqueous cathode has superior gravimetric and volumetric energy densities (∼ 330 W h kg(-1) and ∼ 650 W h L(-1), respectively, from saturated I2 in an aqueous cathode) to the reported aqueous Li-ion batteries and aqueous cathode-type batteries, which provides an opportunity to construct cost-effective and high-performance energy storage. To apply this I3(-)/I(-) aqueous cathode for a portable and compact 3.5 V battery, unlike for grid-scale storage as general target of redox flow batteries, we use a three-dimensional and millimeter thick carbon nanotube current collector for the I3(-)/I(-) redox reaction, which can shorten the diffusion length of the redox couple and provide rapid electron transport. These endeavors allow the Li-I2 battery to enlarge its specific capacity, cycling retention, and maintain a stable potential, thereby demonstrating a promising candidate for an environmentally benign and reusable portable battery.

  3. Synthesis and characterisation of Co-Co(OH)2 composite anode material on Cu current collector for energy storage devices

    Science.gov (United States)

    Yavuz, Abdulcabbar; Yakup Hacıibrahimoğlu, M.; Bedir, Metin

    2017-04-01

    A Co-Co(OH)2 modified electrode on inexpensive Cu substrate was synthesized at room temperature and demonstrated to be a promising anode material for energy storage devices. A modified Co film was obtained potentiostatically and was then potentiodynamically treated with KOH solution to form Co(OH)2. Co-Co(OH)2 coatings were obtained and were dominated by Co(OH)2 at the oxidized side, whereas Co dominant Co-Co(OH)2 occurred at the reduced side (-1.1 V). As OH- ions were able to diffuse into (out of) the film during oxidation (reduction) and did not react with the Cu current collector, the Co-Co(OH)2 electrode can be used as an anode material in energy storage devices. Although the specific capacitance of the electrodes varied depending on thickness, the redox reaction between the modified electrode and KOH electrolyte remained the same consisting of a surface-controlled and diffusion-controlled mechanism which had a desirable fast charge and discharge property. Capacity values remained constant after 250 cycles as the film evolved. Overall capacity retention was 84% for the film after 450 scans. A specific capacitance of 549 F g-1 was obtained for the Co-Co(OH)2 composite electrode in 6 M KOH at a scan rate of 5 mV s-1 and 73% of capacitance was retained when the scan rate was increased to 100 mV s-1.

  4. Carbon-coated Si nanoparticles/reduced graphene oxide multilayer anchored to nanostructured current collector as lithium-ion battery anode

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhengjiao; Guo, Pengqian; Liu, Boli; Xie, Wenhe; Liu, Dequan; He, Deyan, E-mail: hedy@lzu.edu.cn

    2017-02-28

    Silicon is the most promising anode material for the next-generation lithium-ion batteries (LIBs). However, the large volume change during lithiation/delithiation and low intrinsic conductivity hamper its electrochemical performance. Here we report a well-designed LIB anode in which carbon-coated Si nanoparticles/reduced graphene oxide (Si/rGO) multilayer was anchored to nanostructured current collector with stable mechanical support and rapid electron conduction. Furthermore, we improved the integral stability of the electrode through introducing amorphous carbon. The designed anode exhibits superior cyclability, its specific capacity remains above 800 mAh g{sup −1} after 350 cycles at a current density of 2.0 A g{sup −1}. The excellent electrochemical performance can be attributed to the fact that the Si/rGO multilayer is reinforced by the nanostructured current collector and the formed amorphous carbon, which can maintain the structural and electrical integrities of the electrode.

  5. TaxCollector: Modifying Current 16S rRNA Databases for the Rapid Classification at Six Taxonomic Levels

    Directory of Open Access Journals (Sweden)

    Eric W. Triplett

    2010-07-01

    Full Text Available The high level of conservation of 16S ribosomal RNA gene (16S rRNA in all Prokaryotes makes this gene an ideal tool for the rapid identification and classification of these microorganisms. Databases such as the Ribosomal Database Project II (RDP-II and the Greengenes Project offer access to sets of ribosomal RNA sequence databases useful in identification of microbes in a culture-independent analysis of microbial communities. However, these databases do not contain all of the taxonomic levels attached to the published names of the bacterial and archaeal sequences. TaxCollector is a set of scripts developed in Python language that attaches taxonomic information to all 16S rRNA sequences in the RDP-II and Greengenes databases. These modified databases are referred to as TaxCollector databases, which when used in conjunction with BLAST allow for rapid classification of sequences from any environmental or clinical source at six different taxonomic levels, from domain to species. The TaxCollector database prepared from the RDP-II database is an important component of a new 16S rRNA pipeline called PANGEA. The usefulness of TaxCollector databases is demonstrated with two very different datasets obtained using samples from a clinical setting and an agricultural soil. The six TaxCollector scripts are freely available on http://taxcollector.sourceforge.net and on http://www.microgator.org.

  6. Microbial Fuel Cell Cathodes With Poly(dimethylsiloxane) Diffusion Layers Constructed around Stainless Steel Mesh Current Collectors

    KAUST Repository

    Zhang, Fang; Saito, Tomonori; Cheng, Shaoan; Hickner, Michael A.; Logan, Bruce E.

    2010-01-01

    A new and simplified approach for making cathodes for microbial fuel cells (MFCs) was developed by using metal meshcurrent collectorsandinexpensive polymer/carbon diffusion layers (DLs). Rather than adding a current collector to a cathode material such as carbon cloth, we constructed the cathode around the metal mesh itself, thereby avoiding the need for the carbon cloth or other supporting material. A base layer of poly(dimethylsiloxane) (PDMS) and carbon black was applied to the air-side of a stainless steel mesh, and Pt on carbon black with Nafion binder was applied to the solutionside as catalyst for oxygen reduction. The PDMS prevented water leakage and functioned as a DL by limiting oxygen transfer through the cathode and improving coulombic efficiency. PDMS is hydrophobic, stable, and less expensive than other DL materials, such as PTFE, that are commonly applied to air cathodes. Multiple PDMS/carbon layers were applied in order to optimize the performance of the cathode. Two PDMS/ carbon layers achieved the highest maximum power density of 1610 ± 56 mW/m 2 (normalized to cathode projected surface area; 47.0 ± 1.6 W/m3 based on liquid volume). This power output was comparable to the best result of 1635 ± 62 mW/m2 obtained using carbon cloth with three PDMS/carbon layers and a Pt catalyst. The coulombic efficiency of the mesh cathodes reached more than 80%, and was much higher than the maximum of 57% obtained with carbon cloth. These findings demonstrate that cathodes can be constructed around metal mesh materials such as stainless steel, and that an inexpensive coating of PDMS can prevent water leakage and lead to improved coulombic efficiencies. © 2010 American Chemical Society.

  7. Microbial Fuel Cell Cathodes With Poly(dimethylsiloxane) Diffusion Layers Constructed around Stainless Steel Mesh Current Collectors

    KAUST Repository

    Zhang, Fang

    2010-02-15

    A new and simplified approach for making cathodes for microbial fuel cells (MFCs) was developed by using metal meshcurrent collectorsandinexpensive polymer/carbon diffusion layers (DLs). Rather than adding a current collector to a cathode material such as carbon cloth, we constructed the cathode around the metal mesh itself, thereby avoiding the need for the carbon cloth or other supporting material. A base layer of poly(dimethylsiloxane) (PDMS) and carbon black was applied to the air-side of a stainless steel mesh, and Pt on carbon black with Nafion binder was applied to the solutionside as catalyst for oxygen reduction. The PDMS prevented water leakage and functioned as a DL by limiting oxygen transfer through the cathode and improving coulombic efficiency. PDMS is hydrophobic, stable, and less expensive than other DL materials, such as PTFE, that are commonly applied to air cathodes. Multiple PDMS/carbon layers were applied in order to optimize the performance of the cathode. Two PDMS/ carbon layers achieved the highest maximum power density of 1610 ± 56 mW/m 2 (normalized to cathode projected surface area; 47.0 ± 1.6 W/m3 based on liquid volume). This power output was comparable to the best result of 1635 ± 62 mW/m2 obtained using carbon cloth with three PDMS/carbon layers and a Pt catalyst. The coulombic efficiency of the mesh cathodes reached more than 80%, and was much higher than the maximum of 57% obtained with carbon cloth. These findings demonstrate that cathodes can be constructed around metal mesh materials such as stainless steel, and that an inexpensive coating of PDMS can prevent water leakage and lead to improved coulombic efficiencies. © 2010 American Chemical Society.

  8. 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.

  9. Influence of copper volume fraction on tensile strain/stress tolerances of critical current in a copper-plated DyBCO-coated conductor

    International Nuclear Information System (INIS)

    Ochiai, Shojiro; Okuda, Hiroshi; Arai, Takahiro; Sugano, Michinaka; Osamura, Kozo; Prusseit, Werner

    2013-01-01

    The influence of the volume fraction (V f ) of copper, plated at room temperature over a DyBa 2 Cu 3 O 7-δ -coated conductor, on the tensile strain tolerance and stress tolerance of critical current at 77 K was studied over a wide range of copper V f values. The copper plating exerts a tensile stress during cooling because copper has a higher coefficient of thermal expansion than the substrate conductor. Before application of tensile strain, the copper plated at room temperature yielded at 77 K when the copper V f was lower than a critical value, and was in an elastic state at 77 K when the copper V f was higher than the critical value. The strain tolerance of critical current increased with increasing copper V f due to an increase in thermally induced compressive strain in the substrate tape. The stress tolerance of critical current decreased with increasing copper V f because copper is softer than the substrate tape. These results, together with the trade-off between strain tolerance and stress tolerance (i.e., stress tolerance decreases with increasing strain tolerance), were analyzed by modeling. The results show that the restriction imposed by the trade-off, which limits the ability to simultaneously obtain a high strain tolerance and a high stress tolerance, can be relaxed by strengthening the copper. (author)

  10. Effect of electrolysis parameters on the morphologies of copper powder obtained at high current densities

    Directory of Open Access Journals (Sweden)

    Orhan Gökhan

    2012-01-01

    Full Text Available The effects of copper ion concentrations and electrolyte temperature on the morphologies and on the apparent densities of electrolytic copper powders at high current densities under galvanostatic regime were examined. These parameters were evaluated by the current efficiency of hydrogen evolution. In addition, scanning electron microscopy was used for analyzing the morphology of the copper powders. It was found that the morphology was dependent over the copper ion concentration and electrolyte temperature under same current density (CD conditions. At 150 mA cm-2 and the potential of 1000±20 mV (vs. SCE, porous and disperse copper powders were obtained at low concentrations of Cu ions (0.120 M Cu2+ in 0.50 M H2SO4. Under this condition, high rate of hydrogen evolution reaction took place parallel to copper electrodeposition. The morphology was changed from porous, disperse and cauliflower-like to coral-like, shrub-like and stalk-stock like morphology with the increasing of Cu ion concentrations towards 0.120 M, 0.155 M, 0.315 M, 0.475 M and 0.630 M Cu2+ in 0.5 M H2SO4 respectively at the same CD. Similarly, as the temperature was increased, powder morphology and apparent density were observed to be changed. The apparent density values of copper powders were found to be suitable for many of the powder metallurgy applications.

  11. Reagent conditions of the flotation of copper, copper - molybdenum and copper -zinc ores in foreing countries

    International Nuclear Information System (INIS)

    Nevaeva, L.M.

    1983-01-01

    Reagents-collectors and frothers, used abroad in reagent regimes of flotation of copper, copper-molybdenum and copper zinc ores, have been considered. Xanthogenates, aerofloats, xanthogenformiates, thionocarbamates are mainly used as reagents-collectors. Methylizobutylcarbinol and Daufros are used as reagents-frothers

  12. Counter-current acid leaching process for copper azole treated wood waste.

    Science.gov (United States)

    Janin, Amélie; Riche, Pauline; Blais, Jean-François; Mercier, Guy; Cooper, Paul; Morris, Paul

    2012-09-01

    This study explores the performance of a counter-current leaching process (CCLP) for copper extraction from copper azole treated wood waste for recycling of wood and copper. The leaching process uses three acid leaching steps with 0.1 M H2SO4 at 75degrees C and 15% slurry density followed by three rinses with water. Copper is recovered from the leachate using electrodeposition at 5 amperes (A) for 75 min. Ten counter-current remediation cycles were completed achieving > or = 94% copper extraction from the wood during the 10 cycles; 80-90% of the copper was recovered from the extract solution by electrodeposition. The counter-current leaching process reduced acid consumption by 86% and effluent discharge volume was 12 times lower compared with the same process without use of counter-current leaching. However, the reuse of leachates from one leaching step to another released dissolved organic carbon and caused its build-up in the early cycles.

  13. Current Status and Future Prospects of Copper Oxide Heterojunction Solar Cells

    OpenAIRE

    Terence K. S. Wong; Siarhei Zhuk; Saeid Masudy-Panah; Goutam K. Dalapati

    2016-01-01

    The current state of thin film heterojunction solar cells based on cuprous oxide (Cu2O), cupric oxide (CuO) and copper (III) oxide (Cu4O3) is reviewed. These p-type semiconducting oxides prepared by Cu oxidation, sputtering or electrochemical deposition are non-toxic, sustainable photovoltaic materials with application potential for solar electricity. However, defects at the copper oxide heterojunction and film quality are still major constraining factors for achieving high power conversion e...

  14. 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.

  15. One hundred fold increase in current carrying capacity in a carbon nanotube-copper composite

    Science.gov (United States)

    Subramaniam, Chandramouli; Yamada, Takeo; Kobashi, Kazufumi; Sekiguchi, Atsuko; Futaba, Don N.; Yumura, Motoo; Hata, Kenji

    2013-07-01

    Increased portability, versatility and ubiquity of electronics devices are a result of their progressive miniaturization, requiring current flow through narrow channels. Present-day devices operate close to the maximum current-carrying-capacity (that is, ampacity) of conductors (such as copper and gold), leading to decreased lifetime and performance, creating demand for new conductors with higher ampacity. Ampacity represents the maximum current-carrying capacity of the object that depends both on the structure and material. Here we report a carbon nanotube-copper composite exhibiting similar conductivity (2.3-4.7 × 105Scm-1) as copper (5.8 × 105Scm-1), but with a 100-times higher ampacity (6 × 108Acm-2). Vacuum experiments demonstrate that carbon nanotubes suppress the primary failure pathways in copper as observed by the increased copper diffusion activation energy (~2.0eV) in carbon nanotube-copper composite, explaining its higher ampacity. This is the only material with both high conductivity and high ampacity, making it uniquely suited for applications in microscale electronics and inverters.

  16. Multishelled Si@Cu Microparticles Supported on 3D Cu Current Collectors for Stable and Binder-free Anodes of Lithium-Ion Batteries.

    Science.gov (United States)

    Zhang, Zailei; Wang, Zhong Lin; Lu, Xianmao

    2018-04-24

    Silicon has proved to be a promising anode material of high-specific capacity for the next-generation lithium ion batteries (LIBs). However, during repeated discharge/charge cycles, Si-based electrodes, especially those in microscale size, pulverize and lose electrical contact with the current collectors due to large volume expansion. Here, we introduce a general method to synthesize Cu@M (M = Si, Al, C, SiO 2 , Si 3 N 4 , Ag, Ti, Ta, SnIn 2 O 5 , Au, V, Nb, W, Mg, Fe, Ni, Sn, ZnO, TiN, Al 2 O 3 , HfO 2 , and TiO 2 ) core-shell nanowire arrays on Cu substrates. The resulting Cu@Si nanowire arrays were employed as LIB anodes that can be reused via HCl etching and H 2 -reduction. Multishelled Cu@Si@Cu microparticles supported on 3D Cu current collectors were further prepared as stable and binder-free LIB anodes. This 3D Cu@Si@Cu structure allows the interior conductive Cu network to effectively accommodate the volume expansion of the electrode and facilitates the contact between the Cu@Si@Cu particles and the current collectors during the repeated insertion/extraction of lithium ions. As a result, the 3D Cu@Si@Cu microparticles at a high Si-loading of 1.08 mg/cm 2 showed a capacity retention of 81% after 200 cycles. In addition, charging tests of 3D Cu@Si@Cu-LiFePO 4 full cells by a triboelectric nanogenerator with a pulsed current demonstrated that LIBs with silicon anodes can effectively store energy delivered by mechanical energy harvesters.

  17. 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

  18. 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)

  19. Effect of coating current density on the wettability of electrodeposited copper thin film on aluminum substrate

    Directory of Open Access Journals (Sweden)

    Arun Augustin

    2016-09-01

    Full Text Available Copper is the only one solid metal registered by the US Environmental Protection Agency as an antimicrobial touch surface. In touch surface applications, wettability of the surface has high significance. The killing rate of the harmful microbes depends on the wetting of pathogenic solution. Compared to the bulk copper, coated one on aluminum has the advantage of economic competitiveness and the possibility of manufacturing complex shapes. In the present work, the copper coating on the aluminum surface has successfully carried out by electrodeposition using non cyanide alkaline bath. To ensure good adhesion strength, the substrate has been pre-zincated prior to copper deposition. The coating current density is one of the important parameters which determine the nucleation density of the copper on the substrate. To understand the effect of current density on wettability, the coating has done at different current densities in the range of 3 A dm−2 to 9 A dm−2 for fixed time interval. The grain size has been measured from TEM micrographs and showed that as current density increases, grain size reduces from 62 nm to 35 nm. Since the grain size reduces, grain boundary volume has increases. As a result the value of strain energy (calculated by Williamson–Hall method has increased. The density of nodular morphology observed in SEM analysis has been increased with coating current density. Further, wettability studies with respect to double distilled water on the electrodeposited copper coatings which are coated at different current densities are carried out. At higher current density the coating is more wettable by water because at these conditions grain size of the coating decreases and morphology of grain changes to a favorable dense nodularity.

  20. Current state of copper stabilizers and methodology towards calculating risk

    CERN Document Server

    Koratzinos, M

    2011-01-01

    The talk will start by reviewing the landscape: a brief mention of the results of the warm copper stabilizer measurements and the results of the splice measurements at cold will be shown. The preliminary results of the recent RRR measurements will then be presented. Then, together with the limits presented from talk no. 2, the probability of an incident will be presented for beam energies between 3.5 and 5TeV. The available methods at our disposal for addressing the limiting factors and operating at a higher energy will then be reviewed: a complete circuit qualification method coined the Thermal Amplifier can define the maximum safe energy of the LHC in case of a quench next to a defective joint. Ways of avoiding magnet quenches, another critical element of the analysis, for instance by optimizing BLM settings will then be shown. Finally, a proposal of a strategy for running at the highest possible energy compatible with a pre-defined level of risk will be presented. As a case study, the method will also be a...

  1. Electrodeposition of copper from a copper sulfate solution using a packed-bed continuous-recirculation flow reactor at high applied electric current

    Directory of Open Access Journals (Sweden)

    Meshaal F. Alebrahim

    2015-09-01

    Full Text Available The purpose of this study is mainly to investigate the performance of a packed-bed continuous-recirculation flow reactor at high applied electric current in removing copper, Cu(II, from simulated electrolyte by electrodeposition. The effects of pHo, circulation rate of flow, initial copper concentration, intensity of the applied current and the method of application of electric current, as to have a constant value during all the time of electrolysis or to be decreased with time, on copper electrodeposition and current efficiency are revealed. The results showed that the increase in pH (provided not lead to the deposition of Cu(OH2, initial concentration of the copper and flow rate increased the electrodeposition of copper as well as improved current efficiency. However, increasing intensity of the applied electric current led to an increase in the electrodeposition of copper and decreased electrical efficiency. It was also observed that reducing the intensity of applied electric current with time during the electrolysis process while maintaining other operating variables constant led to a significant reduction in the consumption of electrical energy used in the process of copper removal by electrodeposition; a reduction of 41.6% could be achieved.

  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. Dataset demonstrating effects of momentum transfer on sizing of current collector for lithium-ion batteries during laser cutting.

    Science.gov (United States)

    Lee, Dongkyoung; Mazumder, Jyotirmoy

    2018-04-01

    Material properties of copper and aluminum required for the numerical simulation are presented. Electrodes used for the (paper) are depicted. This study describes the procedures of how penetration depth, width, and absorptivity are obtained from the simulation. In addition, a file format extracted from the simulation to visualize 3D distribution of temperature, velocity, and melt pool geometry is presented.

  4. Dataset demonstrating effects of momentum transfer on sizing of current collector for lithium-ion batteries during laser cutting

    Directory of Open Access Journals (Sweden)

    Dongkyoung Lee

    2018-04-01

    Full Text Available Material properties of copper and aluminum required for the numerical simulation are presented. Electrodes used for the (paper are depicted. This study describes the procedures of how penetration depth, width, and absorptivity are obtained from the simulation. In addition, a file format extracted from the simulation to visualize 3D distribution of temperature, velocity, and melt pool geometry is presented.

  5. LiFePO_4_−_xN_y thin-film electrodes coated on carbon fiber-modified current collectors for pseudocapacitors

    International Nuclear Information System (INIS)

    Chiu, Kuo-Feng; Su, Shih-Hsuan; Leu, Hoang-Jyh; Huang, Wei-Chieh

    2015-01-01

    LiFePO_4_−_xN_y thin films were sputter-deposited on micron carbon fibers (MCFs) under a gas mixture of N_2/Ar/H_2 as electrode materials in pseudocapacitors. The MCFs were fabricated by thermal chemical vapor deposition on stainless steel substrates as current collectors. Various amounts of N_2 were introduced by controlling the flow ratios of N_2 to Ar/H_2. The LiFePO_4_−_xN_y thin films coated on the surfaces of MCFs were observed by field emission scanning electron microscopy. The electrochemical properties of the LiFePO_4_−_xN_y thin films were characterized using cyclic voltammetry and charge–discharge processes. The LiFePO_4_−_xN_y thin-film electrode deposited under the optimal N_2 contents exhibited a high specific capacitance of 722 F/g at 1 A/g. Even at a current of 20 A/g, the electrode delivered a capacitance of 298 F/g. The pseudocapacitors using LiFePO_4_−_xN_y thin-film electrodes showed no significant capacitance fading after 1000 cycles at 1 A/g. The results indicated that nitrogen doping improved the electrochemical performances of LiFePO_4, demonstrating the potential of LiFePO_4_−_xN_y as an active material in pseudocapacitors. - Highlights: • LiFePO_4_−_xN_y thin films were sputter-deposited on micron carbon fibers (MCFs). • MCFs only act as a three-dimensional current collector in this system. • The pseudocapacitor exhibits a high specific capacitance.

  6. Research and Application of FTA and Petri Nets in Fault Diagnosis in the Pantograph-Type Current Collector on CRH EMU Trains

    Directory of Open Access Journals (Sweden)

    Long-long Song

    2015-01-01

    Full Text Available A fault tree is established based on structural analysis, working principle analysis, and failure mode and effects analysis (FMEA of the pantograph-type current collector on the Chinese Rail High-Speed Electric Multiple Unit (CRH EMU train. To avoid the deficiencies of fault tree analysis (FTA, Petri nets modelling is used to address the problem of data explosion and carry out dynamic diagnosis. Relational matrix analysis is used to solve the minimal cut set equation of the fault tree. Based on the established state equation of the Petri nets, initial tokens and enable-transfer algorithms are used to express the fault transfer process mathematically and improve the efficiency of fault diagnosis inferences. Finally, using a practical fault diagnosis example for the pantographs on CRH EMU trains, the proposed method is proved to be reasonable and effective.

  7. 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.

  8. Morphological features of the copper surface layer under sliding with high density electric current

    Energy Technology Data Exchange (ETDEWEB)

    Fadin, V. V., E-mail: fvv@ispms.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); Aleutdinova, M. I., E-mail: aleut@ispms.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); Seversk Technological Institute, Branch of State Autonomous Educational Institution of Higher Professional Education “National Research Nuclear University “MEPhI”, Seversk, 636036 (Russian Federation); Rubtsov, V. Ye., E-mail: rvy@ispms.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Aleutdinova, V. A., E-mail: valery-aleut@yandex.ru [National Research St. Petersburg State Polytechnical University, St. Petersburg, 195251 (Russian Federation)

    2015-10-27

    Conductivity and wear intensity of copper under the influence of dry friction and electric current with contact density higher 100 A/cm{sup 2} are presented. It is shown that an increase in hardness and heat outflow from a friction zone leads to the reduction of wear intensity and current contact density increase corresponding to the beginning of catastrophic wear. Structural changes, such as the formation of FeO oxide and α-Fe particles in the copper surface layer, have also been found. It is observed that a worn surface is deformed according to a viscous liquid mechanism. Such singularity is explained in terms of appearance of high-excited atomic states in deforming micro-volumes near contact spots that lead to easy stress relaxation by local plastic shears in the vicinity of stress concentrators. In common this effect allows to achieve high wear resistance.

  9. AC over-current characteristics of YBCO coated conductor with copper stabilizer layer considering insulation layer

    International Nuclear Information System (INIS)

    Du, H.-I.; Kim, M.-J.; Kim, Y.-J.; Lee, D.-H.; Han, B.-S.; Song, S.-S.

    2010-01-01

    Compared with the first-generation BSCCO wire, the YBCO thin-film wire boasts low material costs and high J c and superior magnetic-field properties, among other strengths. Meanwhile, the previous BSCCO wire material for superconducting cables has been researched on considerably with regard to its post-wire quenching characteristics during the application of an alternating over-current. In this regard, the promising YBCO thin-film wire has yet to be further researched on. Moreover, still lacking is research on the YBCO thin-film wire with insulating layers, which is essential in the manufacture of superconducting cables, along with the testing of the application of an alternating over-current to the wire. In this study, YBCO thin-film wires with copper-stabilizing layers were used in testing alternating over-current application according to the presence or absence of insulating layers and to the thickness of such layers, to examine the post-quenching wire resistance increase and quenching trends. The YBCO thin-film wire with copper-stabilizing layers has a critical temperature of 90 K and a critical current of 85 A rms . Moreover, its current application cycle is 5.5 cycles, and its applied currents are 354, 517, 712, and 915 A peak . These figures enabled the YBCO thin-film wires with copper-stabilizing layers to reach 90, 180, 250, and 300 K, respectively, in this study. These temperatures serve as a relative reference to examine the post-quenching wire properties following the application of an alternating over-current.

  10. Surface and near surface defect detection in thick copper EB-welds using eddy current testing

    International Nuclear Information System (INIS)

    Pitkaenen, J.; Lipponen, A.

    2010-01-01

    The surface inspection of thick copper electron beam (EB) welds plays an important role in the acceptance of nuclear fuel disposal. The main reasons to inspect these components are related to potential manufacturing and handling defects. In this work the data acquisition software, visualising tools for eddy current (EC) measurements and eddy current sensors were developed for detection of unwanted defects. The eddy current equipment was manufactured by IZFP and the visualising software in active co-operation with Posiva and IZFP for the inspections. The inspection procedure was produced during the development of the inspection techniques. The inspection method development aims to qualify the method for surface and near surface defect detection and sizing according to ENIQ. The study includes technical justification to be carried out, and compilation of a defect catalogue and experience from measurements within the Posiva's research on issues related to manufacturing. The depth of penetration in copper components in eddy current testing is rather small. To detect surface breaking defects the eddy current inspection is a good solution. A simple approach was adopted using two techniques: higher frequency was used to detect surface defects and to determine the dimensions of the defects except depth, lower frequency was used to detect defects having a ligament and for sizing of deeper surface breaking defects. The higher frequency was 30 kHz and the lower frequency was 200 Hz. The higher frequency probes were absolute bobbing coils and lower frequency probes combined transmitter - several receiver coils. To evaluate both methods, calibration blocks were manufactured by FNS for weld inspections. These calibration specimens mainly consisted of electron discharge machined notches and holes of varying shapes, lengths and diameters in the range of 1 mm to 20 mm of depth. Also one copper lid specimen with 152 defects was manufactured and used for evaluation of weld inspection

  11. Stabilized copper plating method by programmed electroplated current: Accumulation of densely packed copper grains in the interconnect

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Li-Chi; Hsu, Li-Hsuan; Brahma, Sanjaya; Huang, Bo-Chia; Liu, Chun-Chu; Lo, Kuang-Yao, E-mail: kuanglo@mail.ncku.edu.tw

    2016-12-01

    Highlights: • Actual Cu interconnect experiences many times of annealing and then cause the stress. • Stack Cu grains with varying grain size successively to enhance packed density. • XRD and PBR analyze the residual stress of local and average area of plated Cu film. • High packed Cu grain with stable stress proved by texture of Cu(1 1 1) and Cu(2 0 0). - Abstract: In this work, we programmed the plating current to stack the different size of copper (Cu) grain and analyzed the relation between the sequence of different Cu grain size and the stability of the residual stress. The residual stress was measured with varying times of annealing process in order to reach the purpose of simulating the actual Cu interconnect process. We found that varied plating strategy will make different stabilization condition of residual stress through the proof of X-ray diffraction (XRD) and optical parallel beams reflection (PBR) method. The accumulation of Cu grains, formed by Cu grain with successive variation in grain size, would enhance the packing density better than only single grain size in the finite space. The high density of the grain boundary in the electroplated Cu film will be eliminated through annealing process and it will help to suppress the void formation in further interconnect process. The electroplated Cu film with the plating current of saw tooth wave can soon reach a stable tensile stress through annealing since the Cu grains with high packing density will be quickly eliminated to approach the minimum of the strain energy which reflects to variation in the texture of Cu (2 0 0). The result of this work illustrates the importance of how to stack different size of Cu grain, for achieving a densely packed Cu film which close to the Cu bulk.

  12. 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 ...

  13. Role of perfluoropolyether-based electrolytes in lithium metal batteries: Implication for suppressed Al current collector corrosion and the stability of Li metal/electrolytes interfaces

    Science.gov (United States)

    Cong, Lina; Liu, Jia; Armand, Michel; Mauger, Alain; Julien, Christian M.; Xie, Haiming; Sun, Liqun

    2018-03-01

    The development of safe and high performance lithium metal batteries represents a major technological challenge for this new century. Historically, intrinsic instabilities of conventional liquid organic electrolytes induced battery failures and safety issues that hinder the practical utilization of advanced rechargeable lithium metal batteries. Herein, we report a multifunctional perfluoropolyether-based liquid polymer electrolyte (PFPE-MC/LiTFSI), presenting a unique "anion-solvent" interaction. This interaction optimizes the interfacial chemistry of lithium metal batteries, which effectively inhibits the corrosion of aluminum current collectors, suppresses lithium dendrite growth, and also facilitates the formation of a thin and stable SEI layer on Li anode. Even at a high current density of 0.7 mA cm-2, the lithium dendrites do not form after 1360 h of continuous operation. The LiFePO4|PFPE-MC/LiTFSI|Li cell delivers a stable cycling performance with over 99.9% columbic efficiency either at ambient temperature or high temperature, which is significantly superior to those using traditional carbonate electrolytes. In addition, PFPE-MC/LiTFSI electrolyte also possesses eye-catching properties, such as being non-flammable, non-volatile, non-hygroscopic, and existing in the liquid state between -90 °C and 200 °C, which further ensures the high safety of the lithium metal batteries, making this electrolyte promising for the development of high energy lithium metal batteries.

  14. Current Status and Future Prospects of Copper Oxide Heterojunction Solar Cells.

    Science.gov (United States)

    Wong, Terence K S; Zhuk, Siarhei; Masudy-Panah, Saeid; Dalapati, Goutam K

    2016-04-07

    The current state of thin film heterojunction solar cells based on cuprous oxide (Cu₂O), cupric oxide (CuO) and copper (III) oxide (Cu₄O₃) is reviewed. These p-type semiconducting oxides prepared by Cu oxidation, sputtering or electrochemical deposition are non-toxic, sustainable photovoltaic materials with application potential for solar electricity. However, defects at the copper oxide heterojunction and film quality are still major constraining factors for achieving high power conversion efficiency, η. Amongst the Cu₂O heterojunction devices, a maximum η of 6.1% has been obtained by using pulsed laser deposition (PLD) of Al x Ga 1- x O onto thermal Cu₂O doped with Na. The performance of CuO/n-Si heterojunction solar cells formed by magnetron sputtering of CuO is presently limited by both native oxide and Cu rich copper oxide layers at the heterointerface. These interfacial layers can be reduced by using a two-step sputtering process. A high η of 2.88% for CuO heterojunction solar cells has been achieved by incorporation of mixed phase CuO/Cu₂O nanopowder. CuO/Cu₂O heterojunction solar cells fabricated by electrodeposition and electrochemical doping has a maximum efficiency of 0.64% after surface defect passivation and annealing. Finally, early stage study of Cu₄O₃/GaN deposited on sapphire substrate has shown a photovoltaic effect and an η of ~10 -2 %.

  15. THE DYNAMIC INTERACTION OF THE MOVING CONTACTING SURFACES AT THE EXAMPLE OF THE ELECTRIC ROLLING STOCK CURRENT COLLECTOR

    Directory of Open Access Journals (Sweden)

    M. O. Babiak

    2009-07-01

    Full Text Available The process of mutual moving and contacting of surfaces of current collecting pantograph elements and contact network is considered taking into account the particularities of inf1uence of speed and acceleration parameters, determination of which will allow to forecast mathematically the wear-out degree of contacting elements.

  16. 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

  17. Generation of Electricity Using Spartina Patens with Stainless Steel Current Collectors in a Plant-Microbial Fuel Cell

    Science.gov (United States)

    Narula, Deep

    At present, the global energy infrastructure is highly dependent on (i) non-renewable fossil fuels with significant emissions of greenhouse gasses (ii) green fuels such as bioethanol and biodiesel with impact on current agricultural practices competing with food production for arable lands, fertilizers, also requiring additional energy input. Plant-based microbial fuel cell (PMFC) technology can be found as a promising alternative to produce electricity without any side effects with an advantage of using sunlight as an energy source. In the present study, we developed PMFCs using Spartina patens, a marshland grass, abundantly available in the coastal regions of the USA. Figure 1 is a schematic for a PMFC with the anode and cathode compartments where others have used carbon-based electrodes for current collection. In contrast, we attempted to utilize stainless steel wires with more surface area to enhance the current collection in the anode compartment as well as to increase the rate of reduction in the cathode chamber and thereby increase the amount of electricity produced. The study will give results on the periodic use of Spartina patens in PMFC along with the porous stainless steel electrodes which have never been employed in PMFCs before.

  18. 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...

  19. Cross-stacked carbon nanotube film as an additional built-in current collector and adsorption layer for high-performance lithium sulfur batteries.

    Science.gov (United States)

    Sun, Li; Kong, Weibang; Li, Mengya; Wu, Hengcai; Jiang, Kaili; Li, Qunqing; Zhang, Yihe; Wang, Jiaping; Fan, Shoushan

    2016-02-19

    Cross-stacked carbon nanotube (CNT) film is proposed as an additional built-in current collector and adsorption layer in sulfur cathodes for advanced lithium sulfur (Li-S) batteries. On one hand, the CNT film with high conductivity, microstructural rough surface, high flexibility and mechanical durability retains stable and direct electronic contact with the sulfur cathode materials, therefore decreasing internal resistivity and suppressing polarization of the cathode. On the other hand, the highly porous structure and the high surface area of the CNT film provide abundant adsorption points to support and confine sulfur cathode materials, alleviate their aggregation and promote high sulfur utilization. Moreover, the lightweight and compact structure of the CNT film adds no extra weight or volume to the sulfur cathode, benefitting the improvement of energy densities. Based on these characteristics, the sulfur cathode with a 100-layer cross-stacked CNT film presents excellent rate performances with capacities of 986, 922 and 874 mAh g(-1) at cycling rates of 0.2C, 0.5C and 1C for sulfur loading of 60 wt%, corresponding to an improvement of 52%, 109% and 146% compared to that without a CNT film. Promising cycling performances are also demonstrated, offering great potential for scaled-up production of sulfur cathodes for Li-S batteries.

  20. Electrochemical synthesis of SnCo alloy shells on orderly rod-shaped Cu current collectors as anode materials for lithium-ion batteries with enhanced performance

    Energy Technology Data Exchange (ETDEWEB)

    Zhan, Fangwei; Zhang, Hui, E-mail: meszhanghui@zju.edu.cn; Qi, Yue; Wang, Jiazheng; Du, Ning; Yang, Deren

    2013-09-05

    Highlights: •Nanostructured SnCo/Cu electrodes have been successfully fabricated. •A simple electrodeposition approach was employed. •The Cu arrays offer large surface area and improve electronic/ionic conductivity. •The electrodes show improved performance as anode for Li-ion batteries. •The improved performance was attributed to the nanostructured current collectors. -- Abstract: In this article, we report a two-step electrodeposition method for the synthesis of Cu/SnCo core–shell rod-shaped arrays as anodes of lithium-ion batteries. Firstly, the arrayed Cu nanorods with diameters of 200 nm were fabricated on a Cu foil through an electrodeposition method with alumina oxide membrane (AAO) as the template. Secondly, the SnCo alloy shells were subsequently electrodeposited on the surface of the rod-shaped Cu arrays to form the hybrid nanostructures. These hybrid electrodes delivered the enhanced cyclic performance and high rate capability serving as the anode materials for lithium-ion batteries. The improved electrochemical performance might be attributed to the large surface-to-volume area, sufficient buffering space, and high electronic conductivity associated with these 3-dimensional (3D) nanostructures.

  1. Electrochemical behavior of current collectors for lithium batteries in non-aqueous alkyl carbonate solution and surface analysis by ToF-SIMS

    International Nuclear Information System (INIS)

    Myung, Seung-Taek; Sasaki, Yusuke; Sakurada, Shuhei; Sun, Yang-Kook; Yashiro, Hitoshi

    2009-01-01

    Several metals (Cu, Fe, Al, Ti, and Cr) as current collector for lithium-ion battery were investigated to understand their electrochemical behavior and passivation process in a non-aqueous alkyl carbonate solution containing LiPF 6 salt. From cyclic voltammetric study, it was found that Cu and Fe metals were dissolved into the electrolyte below 4 V vs. Li/Li + . Alternatively, Al and Ti were stable up to 5 V vs. Li/Li + . Their scratched surfaces at 5 V vs. Li/Li + were polarized in a transient mode and it was found that the surfaces were passivated during the polarization test. Formed passive film was composed of two hybrid layers: outer layer by metal (Al and Ti) fluoride and inner by metal oxide, as confirmed by time-of-flight secondary ion mass spectroscopy. Presence of HF in the electrolyte was indispensible to form the metal fluoride layer on the oxide layer. The outer fluoride layer would protect the inner oxide layer and metal substrate from HF attack, bringing about satisfactory corrosion resistance under lithium-ion battery environment.

  2. Secondary-electron-emission losses in multistage depressed collectors and traveling-wave-tube efficiency improvements with carbon collector electrode surfaces

    Science.gov (United States)

    Ramins, P.; Ebihara, B. T.

    1986-01-01

    Secondary-electron-emission losses in multistage depressed collectors (MDC's) and their effects on overall traveling-wave-tube (TWT) efficiency were investigated. Two representative TWT's and several computer-modeled MDC's were used. The experimental techniques provide the measurement of both the TWT overall and the collector efficiencies. The TWT-MDC performance was optimized and measured over a wide range of operating conditions, with geometrically identical collectors, which utilized different electrode surface materials. Comparisons of the performance of copper electrodes to that of various forms of carbon, including pyrolytic and iisotropic graphites, were stressed. The results indicate that: (1) a significant improvement in the TWT overall efficiency was obtained in all cases by the use of carbon, rather than copper electrodes, and (2) that the extent of this efficiency enhancement depended on the characteristics of the TWT, the TWT operating point, the MDC design, and collector voltages. Ion textured graphite was found to be particularly effective in minimizing the secondary-electron-emission losses. Experimental and analytical results, however, indicate that it is at least as important to provide a maximum amount of electrostatic suppression of secondary electrons by proper MDC design. Such suppression, which is obtained by ensuring that a substantial suppressing electric field exists over the regions of the electrodes where most of the current is incident, was found to be very effective. Experimental results indicate that, with proper MDC design and the use of electrode surfaces with low secondary-electron yield, degradation of the collector efficiency can be limited to a few percent.

  3. NiO nanoparticles supported on graphene 3D network current collector for high-performance electrochemical energy storage

    International Nuclear Information System (INIS)

    Wang, Mingjun; Song, Xuefen; Dai, Shuge; Xu, Weina; Yang, Qi; Liu, Jianlin; Hu, Chenguo; Wei, Dapeng

    2016-01-01

    Owing to the faradaic oxidation and reduction reactions mainly taking place on surface, enlarging the specific surface of redox materials is one of the most effective ways to achieve excellent electrochemical performance. Here we report a binder-free three dimensional (3D) architecture electrode consisting of a graphene 3D network (G3DN) structure growing on flexible carbon paper (CP) by chemical vapor deposition and NiO nanoparticles growing on the G3DN by in-situ thermal decomposition for high rate battery and high-performance electrochemical capacitors. Such a nanostructure provides a large specific surface and fast electronic transmission channels. The unique structure design for this electrode enables outstanding performance, showing high specific capacity of 89.1 mAh cm −2 (119.2 mAh/g) at current density of 0.5 mA cm −2 (0.67 A/g) with the NiO loading of 0.7471 mg cm −2 . Meanwhile the electrode displays excellent rate capability and cycling stability, which keeps 85.48% of initial capacity after 3000 deep-discharge cycles. Furthermore, a solid-state symmetric electrochemical capacitor based on two NiO/G3DN/CP electrodes with an area of 4 cm 2 each is fabricated, and two pieces of them in series can light up 100 green LEDs for 2 min. The architecture of G3DN loaded with NiO might be generally applied to different kinds of nanomaterials for high-rate energy storage to improve their overall electrochemical performance.

  4. Calendering effect on the electrochemical performances of the thick Li-ion battery electrodes using a three dimensional Ni alloy foam current collector

    International Nuclear Information System (INIS)

    Yang, Gui-Fu; Joo, Seung-Ki

    2015-01-01

    High surface area and a three dimensional NiCrAl alloy foam current collector was used for two kinds of thick lithium iron phosphate electrodes. One kind of electrodes were compressed after the slurry of active material in the metal foam was dried and then annealed at 140 °C for half a day whereas the other kind of electrodes were prepared without pressing. When the addition of carbon black was 4 wt% for the two kinds of electrodes, a charge-discharge test revealed that the capacity of the cell using the pressed electrode faded much more although the voltage-drop was much smaller at the plateau region. For example, the capacity of the pressed electrode exhibited 85 mA h g −1 , while it was 135 mA h g −1 for the unpressed electrode although the voltage-drop at the plateau region was 250 mV higher at 0.5C-rate for the unpressed electrode. The AC impedance analysis showed that the charge transfer resistance of the pressed electrode was only 15 Ω whereas it was 4 times higher for the unpressed electrode. The results illustrated that the effective redox area was much larger for the unpressed electrode since the cell using the unpressed electrode exhibited much higher capacity even at the condition of poor electronic conductivity. To solve the low electronic conductivity issue for the unpressed electrode, the addition of carbon black was further increased to 14 wt% and as a result, there was almost no difference in voltage drop at plateau region or charge transfer resistance between the two kinds of electrodes. Obviously, the capacity of unpressed electrode exhibited much higher at higher current rate due to the larger effective redox area

  5. Current Status and Future Prospects of Copper Oxide Heterojunction Solar Cells

    Directory of Open Access Journals (Sweden)

    Terence K. S. Wong

    2016-04-01

    Full Text Available The current state of thin film heterojunction solar cells based on cuprous oxide (Cu2O, cupric oxide (CuO and copper (III oxide (Cu4O3 is reviewed. These p-type semiconducting oxides prepared by Cu oxidation, sputtering or electrochemical deposition are non-toxic, sustainable photovoltaic materials with application potential for solar electricity. However, defects at the copper oxide heterojunction and film quality are still major constraining factors for achieving high power conversion efficiency, η. Amongst the Cu2O heterojunction devices, a maximum η of 6.1% has been obtained by using pulsed laser deposition (PLD of AlxGa1−xO onto thermal Cu2O doped with Na. The performance of CuO/n-Si heterojunction solar cells formed by magnetron sputtering of CuO is presently limited by both native oxide and Cu rich copper oxide layers at the heterointerface. These interfacial layers can be reduced by using a two-step sputtering process. A high η of 2.88% for CuO heterojunction solar cells has been achieved by incorporation of mixed phase CuO/Cu2O nanopowder. CuO/Cu2O heterojunction solar cells fabricated by electrodeposition and electrochemical doping has a maximum efficiency of 0.64% after surface defect passivation and annealing. Finally, early stage study of Cu4O3/GaN deposited on sapphire substrate has shown a photovoltaic effect and an η of ~10−2%.

  6. Current Status and Future Prospects of Copper Oxide Heterojunction Solar Cells

    Science.gov (United States)

    Wong, Terence K. S.; Zhuk, Siarhei; Masudy-Panah, Saeid; Dalapati, Goutam K.

    2016-01-01

    The current state of thin film heterojunction solar cells based on cuprous oxide (Cu2O), cupric oxide (CuO) and copper (III) oxide (Cu4O3) is reviewed. These p-type semiconducting oxides prepared by Cu oxidation, sputtering or electrochemical deposition are non-toxic, sustainable photovoltaic materials with application potential for solar electricity. However, defects at the copper oxide heterojunction and film quality are still major constraining factors for achieving high power conversion efficiency, η. Amongst the Cu2O heterojunction devices, a maximum η of 6.1% has been obtained by using pulsed laser deposition (PLD) of AlxGa1−xO onto thermal Cu2O doped with Na. The performance of CuO/n-Si heterojunction solar cells formed by magnetron sputtering of CuO is presently limited by both native oxide and Cu rich copper oxide layers at the heterointerface. These interfacial layers can be reduced by using a two-step sputtering process. A high η of 2.88% for CuO heterojunction solar cells has been achieved by incorporation of mixed phase CuO/Cu2O nanopowder. CuO/Cu2O heterojunction solar cells fabricated by electrodeposition and electrochemical doping has a maximum efficiency of 0.64% after surface defect passivation and annealing. Finally, early stage study of Cu4O3/GaN deposited on sapphire substrate has shown a photovoltaic effect and an η of ~10−2%. PMID:28773398

  7. Three-Dimensional Reduced Graphene Oxide Network on Copper Foam as High-performance Supercapacitor Electrodes

    DEFF Research Database (Denmark)

    Dey, Ramendra Sundar; Chi, Qijin

    E lectrochemically generated copper foam (Cuf) could serve as an effective template for fabrication of three - dimensional (3D) reduced graphe n e oxide (rGO) network s. Here we present a facile approach to preparation of 3D rGO network supported by Cuf a s binder - free and current collector - i...

  8. Use of carbon filaments in place of carbon black as the current collector of a lithium cell with a thionyl chloride bromine chloride catholyte

    Science.gov (United States)

    Frysz, Christine A.; Shui, Xiaoping; Chung, D. D. L.

    Submicron carbon filaments (ADNH, Applied Sciences Inc.) used in place of carbon black as porous reduction electrodes (i.e., current collectors) in plate and jellyroll configurations in carbon limited lithium batteries with the BCX (bromine chloride in thionyl chloride) catholyte gave a specific capacity (at 2 V cut-off) of up to 8700 mAh/g of carbon, compared with a value of up to 2900 mAh/g of carbon for carbon black. The high specific capacity for the filament electrode is partly due to the filaments' processability into sheets as thin as 0.2 mm with good porosity, acceptable mechanical properties and without binder, and partly due to the high catholyte absorptivity and high rate of catholyte absorption of the filament electrode. Use of solvent-cleansed filaments in place of as-received filaments in making electrodes increased the packing density, thus decreasing capacity per g of carbon. The BCX catholyte acted as a cleanser anyway, due to the thionyl chloride in it. The specific capacity per cm 3 of carbon and that per unit density of carbon were also increased by using carbon filaments in place of carbon black, provided that the filament electrode was not pressed after forming by slurry filtration. Though no binder was needed for the filament plate electrode, it was needed for the filament jellyroll electrode. The Teflon™ binder increased the tensile strength and modulus, but decreased the catholyte absorption and rate of absorption. The filament electrode exhibited 405 less volume electrical resistivity than the carbon black electrode, both without a binder.

  9. Use of carbon filaments in place of carbon black as the current collector of a lithium cell with a thionyl chloride bromine chloride catholyte

    Energy Technology Data Exchange (ETDEWEB)

    Frysz, C.A. [Technology Div., Wilson Greatbatch Ltd., Clarence, NY (United States); Shui Xiaoping [Composite Materials Research Lab., State Univ. of New York, Buffalo, NY (United States); Chung, D.D.L. [Composite Materials Research Lab., State Univ. of New York, Buffalo, NY (United States)

    1996-01-01

    Submicron carbon filaments (ADNH, Applied Sciences Inc.) used in place of carbon black as porous reduction electrodes (i.e., current collectors) in plate and jellyroll configurations in carbon limited lithium batteries with the BCX (bromine chloride in thionyl chloride) catholyte gave a specific capacity (at 2 V cut-off) of up to 8700 mAh/g of carbon, compared with a value of up to 2900 mAh/g of carbon for carbon black. The high specific capacity for the filament electrode is partly due to the filaments` processability into sheets as thin as 0.2 mm with good porosity, acceptable mechanical properties and without binder, and partly due to the high catholyte absorptivity and high rate of catholyte absorption of the filament electrode. Use of solvent-cleansed filaments in place of as-received filaments in making electrodes increased the packing density, thus decreasing capacity per g of carbon. The BCX catholyte acted as a cleanser anyway, due to the thionyl chloride in it. The specific capacity per cm{sup 3} of carbon and that per unit density of carbon were also increased by using carbon filaments in place of carbon black, provided that the filament electrode was not pressed after forming by slurry filtration. Though no binder was needed for the filament plate electrode, it was needed for the filament jellyroll electrode. The Teflon{sup TM} binder increased the tensile strength and modulus, but decreased the catholyte absorption and rate of absorption. The filament electrode exhibited 40% less volume electrical resistivity than the carbon black electrode, both without a binder. (orig.)

  10. 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.

  11. 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

  12. Bulk Nanocrystalline Metals: Review of the Current State of the Art and Future Opportunities for Copper and Copper Alloys

    Science.gov (United States)

    2014-05-13

    grain size of copper: e.g., Bi,76 Ag,77 Fe,78 Zn,79 W,80 Sb,81 Zr ,82,83 Nb ,84 and Ta.28,29 In gen- eral, the addition of solutes in these systems has...grain size (in percent) as a function of the homologous temperature of Cu for several different solutes: Bi, W, Ag, Fe, Nb , Zr (in increasing order of...electrons in metals, increasing the density of grain boundaries in nanocrystalline materials greatly increases the electrical resistivity (which has

  13. 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

  14. 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.

  15. Effect of copper additions in tin molten pool on stability temperature and critical current of Nb3Sn

    International Nuclear Information System (INIS)

    Kruzliak, J.; Hutka, P.; Tomasich, M.

    1979-01-01

    Tested is the effect of 55 at% copper addition into the tin bath on the stability temperature and crytical current of Nb 3 Sn, prepared by the diffusion method. It is shown that copper presence in the tin bath transfers the stability temperature of NbSn 2 and Nb 6 Sn 5 phases below the annealing temperature of 700 deg C. It results in Nb 3 Sn appearance at the annealing temperatures above 600 deg C. The critical current increase is explained as follows: lower Nb 3 Sn appearance temperatures provide fine-grained structure of superconducting Nb 3 Sn layer with greater density of binning centers and with higher critical current in accordance with NbSn prepared by the diffusion of pure tin into niobium

  16. 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.

  17. Nanostructured Networks for Energy Storage: Vertically Aligned Carbon Nanotubes (VACNT as Current Collectors for High-Power Li4Ti5O12(LTO//LiMn2O4(LMO Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Fabian Pawlitzek

    2017-11-01

    Full Text Available As a concept for electrode architecture in high power lithium ion batteries, self-supported nanoarrays enable ultra-high power densities as a result of their open pore geometry, which results in short and direct Li+-ion and electron pathways. Vertically aligned carbon nanotubes (VACNT on metallic current collectors with low interface resistance are used as current collectors for the chemical solution infiltration of electroactive oxides to produce vertically aligned carbon nanotubes decorated with in situ grown LiMn2O4 (LMO and Li4Ti5O12 (LTO nanoparticles. The production processes steps (catalyst coating, VACNT chemical vapor deposition (CVD, infiltration, and thermal transformation are all scalable, continuous, and suitable for niche market production to achieve high oxide loadings up to 70 wt %. Due to their unique transport structure, as-prepared nanoarrays achieve remarkably high power densities up to 2.58 kW kg−1, which is based on the total electrode mass at 80 C for LiMn2O4//Li4Ti5O12 full cells. The tailoring of LTO and LMO nanoparticle size (~20–100 nm and VACNT length (array height: 60–200 µm gives insights into the rate-limiting steps at high current for these kinds of nanoarray electrodes at very high C-rates of up to 200 C. The results reveal the critical structural parameters for achieving high power densities in VACNT nanoarray full cells.

  18. 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

  19. Potential for improved extraction of tellurium as a byproduct of current copper mining processes

    Science.gov (United States)

    Hayes, S. M.; Spaleta, K. J.; Skidmore, A. E.

    2016-12-01

    Tellurium (Te) is classified as a critical element due to its increasing use in high technology applications, low average crustal abundance (3 μg kg-1), and primary source as a byproduct of copper extraction. Although Te can be readily recovered from copper processing, previous studies have estimated a 4 percent extraction efficiency, and few studies have addressed Te behavior during the entire copper extraction process. The goals of the present study are to perform a mass balance examining Te behavior during copper extraction and to connect these observations with mineralogy of Te-bearing phases which are essential first steps in devising ways to optimize Te recovery. Our preliminary mass balance results indicate that less than 3 percent of Te present in copper ore is recovered, with particularly high losses during initial concentration of copper ore minerals by flotation. Tellurium is present in the ore in telluride minerals (e.g., Bi-Te-S phases, altaite, and Ag-S-Se-Te phases identified using electron microprobe) with limited substitution into sulfide minerals (possibly 10 mg kg-1 Te in bulk pyrite and chalcopyrite). This work has also identified Te accumulation in solid-phase intermediate extraction products that could be further processed to recover Te, including smelter dusts (158 mg kg-1) and pressed anode slimes (2.7 percent by mass). In both the smelter dusts and anode slimes, X-ray absorption spectroscopy indicates that about two thirds of the Te is present as reduced tellurides. In anode slimes, electron microscopy shows that the remaining Te is present in an oxidized form in a complex Te-bearing oxidate phase also containing Pb, Cu, Ag, As, Sb, and S. These results clearly indicate that more efficient, increased recovery of Te may be possible, likely at minimal expense from operating copper processing operations, thereby providing more Te for manufacturing of products such as inexpensive high-efficiency solar panels.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. The effects of applied current on one-dimensional interdiffusion between copper and nickel in spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Rudinsky, S.; Gauvin, R.; Brochu, M., E-mail: mathieu.brochu@mcgill.ca [Department of Mining and Materials Engineering, McGill University, 3610 University Street, Montreal, Quebec H3A 0C5 (Canada)

    2014-10-21

    Spark plasma sintering (SPS) is a powder metallurgy technique that employs the use of fast sintering kinetics to produce final consolidated components in a matter of minutes. In order to use blended powders in SPS to obtain fully alloyed parts, diffusion during sintering must be understood. An investigation into the effects of current on the diffusion of copper and nickel was performed using SPS. Bulk specimens were used to generate diffusion couples in SPS in alternating orientations with respect to the direction of the current. Control samples were produced using a horizontal insertion vacuum furnace. Experiments were performed at temperatures between 850°C and 1000°C for 3 h. Concentration profiles were obtained by the use of both energy-dispersive spectroscopy and a Monte Carlo simulated correction curve. Diffusion coefficients and activation energies were calculated for samples produced by SPS and annealing without current. It was shown that, at temperatures near 0.9 T{sub m}, the application of current in SPS inhibits diffusion between copper and nickel due to the re-orientation of electrons caused by the loss of ferromagnetism in nickel. Activation energy for diffusion is, however, decreased due to the temperature gradients arising from the difference in resistivity between the two species.

  8. 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.

  9. Solar water disinfecting system using compound parabolic concentrating collector

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-05-31

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

  10. 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.

  11. 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.)

  12. Impact of Neutral Point Current Control on Copper Loss Distribution of Five Phase PM Generators Used in Wind Power Plants

    Directory of Open Access Journals (Sweden)

    ARASHLOO, R. S.

    2014-05-01

    Full Text Available Efficiency improvement under faulty conditions is one of the main objectives of fault tolerant PM drives. This goal can be achieved by increasing the output power while reducing the losses. Stator copper loss not only directly affects the total efficiency, but also plays an important role in thermal stress generations of iron core. In this paper, the effect of having control on neutral point current is studied on the efficiency of five-phase permanent magnet machines. Open circuit fault is considered for both one and two phases, and the distribution of copper loss along the windings are evaluated in each case. It is shown that only by having access to neutral point, it is possible to generate less stator thermal stress and more mechanical power in five-phase permanent magnet generators. Wind power generation and their applications are kept in mind, and the results are verified via simulations and experimental tests on an outer-rotor type of five-phase PM machine.

  13. 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

  14. 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.

  15. Cellular copper homeostasis: current concepts on its interplay with glutathione homeostasis and its implication in physiology and human diseases.

    Science.gov (United States)

    Bhattacharjee, Ashima; Chakraborty, Kaustav; Shukla, Aditya

    2017-10-18

    Copper is a trace element essential for almost all living organisms. But the level of intracellular copper needs to be tightly regulated. Dysregulation of cellular copper homeostasis leading to various diseases demonstrates the importance of this tight regulation. Copper homeostasis is regulated not only within the cell but also within individual intracellular compartments. Inactivation of export machinery results in excess copper being redistributed into various intracellular organelles. Recent evidence suggests the involvement of glutathione in playing an important role in regulating copper entry and intracellular copper homeostasis. Therefore interplay of both homeostases might play an important role within the cell. Similar to copper, glutathione balance is tightly regulated within individual cellular compartments. This review explores the existing literature on the role of glutathione in regulating cellular copper homeostasis. On the one hand, interplay of glutathione and copper homeostasis performs an important role in normal physiological processes, for example neuronal differentiation. On the other hand, perturbation of the interplay might play a key role in the pathogenesis of copper homeostasis disorders.

  16. 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...

  17. Measurement of low-frequency base and collector current noise and coherence in SiGe heterojunction bipolar transistors using transimpedance amplifiers

    NARCIS (Netherlands)

    Bruce, S.P.O.; Vandamme, L.K.J.; Rydberg, A.

    1999-01-01

    Transimpedance amplifiers have been used for direct study of current noise in silicon germanium (SiGe) heterojunction bipolar transistors (HBT's) at different biasing conditions. This has facilitated a wider range of resistances in the measurement circuit around the transistor than is possible when

  18. Fabrication of free-standing copper foils covered with highly-ordered copper nanowire arrays

    Science.gov (United States)

    Zaraska, Leszek; Sulka, Grzegorz D.; Jaskuła, Marian

    2012-07-01

    The through-hole nanoporous anodic aluminum oxide (AAO) membranes with relatively large surface area (ca. 2 cm2) were employed for fabrication of free-standing and mechanically stable copper foils covered with close-packed and highly-ordered copper nanowire arrays. The home-made AAO membranes with different pore diameters and interpore distances were fabricated via a two-step self-organized anodization of aluminum performed in sulfuric acid, oxalic acid and phosphoric acid followed by the pore opening/widening procedure. The direct current (DC) electrodeposition of copper was performed efficiently on both sides of AAO templates. The bottom side of the AAO templates was not insulated and consequently Cu nanowire arrays on thick Cu layers were obtained. The proposed template-assisted fabrication of free-standing copper nanowire array electrodes is a promising method for synthesis of nanostructured current collectors. The composition of Cu nanowires was confirmed by energy dispersive X-Ray spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The structural features of nanowires were evaluated from field emission scanning electron microscopy (FE-SEM) images and compared with the characteristic parameters of anodic alumina membranes.

  19. Fabrication of free-standing copper foils covered with highly-ordered copper nanowire arrays

    International Nuclear Information System (INIS)

    Zaraska, Leszek; Sulka, Grzegorz D.; Jaskuła, Marian

    2012-01-01

    The through-hole nanoporous anodic aluminum oxide (AAO) membranes with relatively large surface area (ca. 2 cm 2 ) were employed for fabrication of free-standing and mechanically stable copper foils covered with close-packed and highly-ordered copper nanowire arrays. The home-made AAO membranes with different pore diameters and interpore distances were fabricated via a two-step self-organized anodization of aluminum performed in sulfuric acid, oxalic acid and phosphoric acid followed by the pore opening/widening procedure. The direct current (DC) electrodeposition of copper was performed efficiently on both sides of AAO templates. The bottom side of the AAO templates was not insulated and consequently Cu nanowire arrays on thick Cu layers were obtained. The proposed template-assisted fabrication of free-standing copper nanowire array electrodes is a promising method for synthesis of nanostructured current collectors. The composition of Cu nanowires was confirmed by energy dispersive X-Ray spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The structural features of nanowires were evaluated from field emission scanning electron microscopy (FE-SEM) images and compared with the characteristic parameters of anodic alumina membranes.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. Proceedings of the solar thermal concentrating collector technology symposium

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-08-01

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

  7. A Study on the Development of Nonglass Solar Vacuum Tube Collector

    International Nuclear Information System (INIS)

    Oh, Seung Jin

    2008-02-01

    Nature has been providing us energy from the beginning of the world. However human has hardly used it wisely. Solar energy is a kind of renewable energy from the nature. This study has been carried out to study the use of solar energy as it is harnessed in the form of thermal energy. Solar energy is one of the most promising energy resources such as hydrogen, biomass, wind and geothermal energy, because it is clean and inexhaustible. Space heating in buildings can be provided from solar energy by systems that are similar in many respects to water heater systems. By tapping into solar energy, we can not only solve the problem of energy shortage, but also can protect the environment and benefit the human beings. There are currently two types of evacuated tube; a single glass tube and a double glass tube. The former consists of a single glass tube which contains a flat or curved aluminium plate attached to a copper heat pipe or water flow pipe. The latter consists of rows of parallel transparent glass tubes, each of which contains an absorber tube. Evacuated tube collectors introduced above, however, pose some problems as they break rather easily under mechanical stresses. This paper introduces some preliminary results in design and fabrication of a non-glass solar vacuum tube collector in which the thermosyphon(heat pipe)made of copper is used as a heat transfer device. A series of tests have been performed to assess the ability of a non-glass solar vacuum tube collector. The series of experiments are as follows: 1)Vacuum level inside a vacuum tube. 2)Effects of the air remaining inside a vacuum tube on the temperature on the absorber plate. 3)Comparison of a non-glass vacuum solar collector with a single glass evacuated tube(SEIDO 5). Different vacuum levels inside non-glass vacuum tubes were applied to check any leakage or unexpected physical or chemical developments with time. The vacuum level changed from 10 -2 torr to 5torr in 5 days due to air infiltration from

  8. Measurement of weak electric currents in copper wire phantoms using MRI: influence of susceptibility enhancement.

    Science.gov (United States)

    Huang, Ruiwang; Posnansky, Oleg; Celik, Abdullah; Oros-Peusquens, Ana-Maria; Ermer, Veronika; Irkens, Marco; Wegener, H-Peter; Shah, N Jon

    2006-08-01

    The use of magnetic resonance imaging (MRI)-based methods for the direct detection of neuronal currents is a topic of intense investigation. Much experimental work has been carried out with the express aim of establishing detection thresholds and sensitivity to flowing currents. However, in most of these experiments, magnetic susceptibility enhancement was ignored. In this work, we present results that show the influence of a susceptibility artefact on the detection threshold and sensitivity. For this purpose, a novel phantom, consisting of a water-filled cylinder with two wires of different materials connected in series, was constructed. Magnitude MR images were acquired from a single slice using a gradient-echo echo planar imaging (EPI) sequence. The data show that the time course of the detected MR signal magnitude correlates very well with the waveform of the input current. The effect of the susceptibility artefacts arising from the two different wires was examined by comparing the magnitudes of the MR signals at different voxel locations. Our results indicate the following: (1) MR signal enhancement arising from the magnetic susceptibility effect influences the detection sensitivity of weak current; (2) the detection threshold and sensitivity are phantom-wire dependent; (3) sub-mu A electric current detection in a phantom is possible on a 1.5-T MR scanner in the presence of susceptibility enhancement.

  9. Detection of current-induced vacancies in thin aluminum endash copper lines using positrons

    International Nuclear Information System (INIS)

    Asoka-Kumar, P.; OBrien, K.; Lynn, K.G.; Simpson, P.J.; Rodbell, K.P.

    1996-01-01

    In situ depth-resolved positron annihilation spectroscopy (PAS) is used to show dynamic formation of vacancies in 1 μmx1 μm Al-0.5 wt% Cu lines under current flow. We show that the number of vacancies in these lines increases when a dc current (8x10 4 A/cm 2 ) is applied. This increase in vacancy concentration is substantially greater than that due to thermal vacancy generation alone (4x10 18 cm -3 versus 3x10 17 cm -3 ). Isothermal measurements (with no current flow) yield a vacancy formation energy of 0.60±0.02 eV. These results show that PAS can be used to examine the initial stages of interconnect damage due to electromigration. copyright 1996 American Institute of Physics

  10. Effect of Electric-current Pulses on Grain-structure Evolution in Cryogenically Rolled Copper

    Science.gov (United States)

    2014-11-01

    severely deformed dilute aluminium alloy . Acta Mater. 56, 1619 (2008). 4. T. Konkova, S. Mironov, A. Korznikov, and S.L. Semiatin: Microstructural response...phase transformation and variant selection by electric current pulses in a Cu-Zn alloy . J. Mater. Res. 29, 975 (2014). 13. I.Sh. Valeev and Z.G

  11. Flotation process of lead-, copper-, uranium-, and rare earth minerals

    International Nuclear Information System (INIS)

    Broman, P.G.; Kihlstedt, P.G.; Du Rietz, C.

    1977-01-01

    This invention relates to a flotation process of oxide or sulfide ores containing lead-, copper-, uranium-, and rare earth minerals applicating a new collector. Flotation is in the presence of a tertiary amine

  12. 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.

  13. Alternating current loss characteristics in (bismuth,lead)SCCO and yttrium barium copper oxide superconducting tapes

    Science.gov (United States)

    Nguyen, Doan Ngoc

    Alternating current (AC) loss and current carrying capacity are two of the most crucial considerations in large-scale power applications of high temperature superconducting (HTS) conductors. AC losses result in an increased thermal load for cooling machines, and thus increased operating costs. Furthermore, AC losses can stimulate quenching phenomena or at least decrease the stability margin for superconducting devices. Thus, understanding AC losses is essential for the development of HTS AC applications. The main focus of this dissertation is to make reliable total AC loss measurements and interpret the experimental results in a theoretical framework. With a specially designed magnet, advanced total AC loss measurement system in liquid nitrogen (77 K) has been successfully built. Both calorimetric and electromagnetic methods were employed to confirm the validity of the measured results and to have a more thorough understanding of AC loss in HTS conductors. The measurement is capable of measuring total AC loss in HTS tapes over a wide range of frequency and amplitude of transport current and magnetic field. An accurate phase control technique allows measurement of total AC loss with any phase difference between the transport current and magnetic field by calorimetric method. In addition, a novel total AC loss measurement system with variable temperatures from 30 K to 100 K was successfully built and tested. Understanding the dependence of AC losses on temperature will enable optimization of the operating temperature and design of HTS devices. As a part of the dissertation, numerical calculations using Brandt's model were developed to study electrodynamics and total AC loss in HTS conductors. In the calculations, the superconducting electrical behavior is assumed to follow a power-law model. In general, the practical properties of conductors, including field-dependence of critical current density Jc, n-value and non-uniform distribution of Jc, can be accounted for in

  14. 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.)

  15. 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).

  16. 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...

  17. Investigation of Superficial Resistance of Different Purity Copper at Boiling Nitrogen Temperature Depending on Treatment of Current-Conducting Layer

    International Nuclear Information System (INIS)

    Kutovoj, V.A.; Nikolaenko, A.A.; Stoev, P.I.

    2007-01-01

    Results of this scientific work show influence of annealing temperature and deformation degree of initial MOB copper and after electron beam refining on superficial resistance at temperature of boiling nitrogen. It is shown, that 30 % deformation and annealing in 873...923 K temperature range results in appreciable reduction of superficial resistance at the investigated samples of copper. The lowest values of superficial resistance after thermal and mechanical treatment were observed in the samples after electron beam refinement

  18. 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.

  19. Performance analysis of a heat pipe solar collector having different pitch distance

    Energy Technology Data Exchange (ETDEWEB)

    Sivaraman, B.; Mohan, N.K. [Annamalai Univ., Tamil Nadu (India). Dept. of Mechanical Engineering

    2006-07-01

    Heat pipe solar collectors are more efficient than conventional solar collectors. This paper provided details of experimental analyses conducted to examine the effect of pitch distance on the heat pipe's performance. Two solar collectors with pitch distances of 7.5 cm and 8.5 cm were used in the study. Copper tubing was used as the container material, and methanol was selected as a working fluid for the experiments, which were conducted during the summer at a collector tilt angle of 11 degrees. Experiments were conducted and the impacts of various parameters were measured. Solar intensity was measured using a pyranometer. Water exit and inlet temperatures were measured using mercury thermometers. Results showed that the heat pipe performed optimally when the pitch distance was 0.085 m. 8 refs., 1 tab., 9 figs.

  20. Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

    Science.gov (United States)

    Tecimer, M.; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J.

    2001-12-01

    A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 π mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design.

  1. Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

    Energy Technology Data Exchange (ETDEWEB)

    Tecimer, M. E-mail: tecimer@post.tau.ac.il; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J

    2001-12-21

    A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 {pi} mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design.

  2. Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

    International Nuclear Information System (INIS)

    Tecimer, M.; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J.

    2001-01-01

    A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 π mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design

  3. Copper Recovery from Yulong Complex Copper Oxide Ore by Flotation and Magnetic Separation

    Science.gov (United States)

    Han, Junwei; Xiao, Jun; Qin, Wenqing; Chen, Daixiong; Liu, Wei

    2017-09-01

    A combined process of flotation and high-gradient magnetic separation was proposed to utilize Yulong complex copper oxide ore. The effects of particle size, activators, Na2S dosage, LA (a mixture of ammonium sulfate and ethylenediamine) dosage, activating time, collectors, COC (a combination collector of modified hydroxyl oxime acid and xanthate) dosage, and magnetic intensity on the copper recovery were investigated. The results showed that 74.08% Cu was recovered by flotation, while the average grade of the copper concentrates was 21.68%. Another 17.34% Cu was further recovered from the flotation tailing by magnetic separation at 0.8 T. The cumulative recovery of copper reached 91.42%. The modifier LA played a positive role in facilitating the sulfidation of copper oxide with Na2S, and the combined collector COC was better than other collectors for the copper flotation. This technology has been successfully applied to industrial production, and the results are consistent with the laboratory data.

  4. 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

  5. Numerical and experimental analysis of a point focus solar collector using high concentration imaging PMMA Fresnel lens

    International Nuclear Information System (INIS)

    Xie, W.T.; Dai, Y.J.; Wang, R.Z.

    2011-01-01

    Research highlights: → We studied a point focus Fresnel solar collector using different cavity receivers. → The collector heat removal factors are derived to find the optimal cavity shape. → Numerical and experimental analysis shows that the conical cavity is optimum. -- Abstract: A high concentration imaging Fresnel solar collector provided with different cavity receivers was developed and its behavior was investigated. Round copper pipes winded into different spring shapes were used as receiver by placing in the cylindrical cavity to absorb concentrated solar energy and transfer it to a heat transfer fluid (HTF). The collector efficiency factor and collector heat removal factor were derived for the cavity receivers to find out heat transfer mechanism and to propose an effective way for evaluating the performance of Fresnel solar collector and determining the optimal cavity structure. The problem of Fresnel solar collector with synthetic heat transfer oil flow was simulated and analyzed to investigate heat loss from different cavity receivers. Solar irradiation as well as convection and heat transfer in the circulating fluid and between the internal surfaces of the cavity and the environment are considered in the model. The temperature distribution over its area as well as the collector thermal efficiency at nominal flow rate was used in order to validate the simulation results. It was found that the simulated temperature distribution during operation and the average collector efficiency are in good agreement with the experimental data. Finally, the optimal shape of solar cavity receiver, as well as its thermal performance, are deeply analyzed and discussed.

  6. 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

  7. 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.

  8. 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...

  9. Recovery of copper ion by flotation with potassium amylxanthate

    International Nuclear Information System (INIS)

    Ramirez-Serrano, B.; Coello-Velazquez, A. L.; Bernardo, A.; Afif, E.; Menendez-Aguado, J. M.

    2012-01-01

    In this paper a study about the column flotation process of copper ion employing potassium amylxanthate as collector reagent is carried out. The effect on the recovery of copper ion by the modification of variables such as collector/metal relation and surface velocity of gas and liquid was determined experimentally by the analysis of the statistic-mathematical model of the copper flotation process, as well as the physico-chemical phenomena that take place, showing the effect of the collector/metal relation in the process. The effect of pH as the main properties of the chemical system in the recovery and the kinetic of the flotation process is made too. The experimental results shows that the recovery of copper in the pH range of 4,5 - 12 is possible with prevalence of precipitate flotation. (Author) 43 refs.

  10. 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)

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

    International Nuclear Information System (INIS)

    Khaled Toufeka; Mourad Haddadib; Ali Mkc

    2011-01-01

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

  12. 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.

  13. 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)

  14. 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

  15. 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)

  16. 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)

  17. 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)

  18. 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.

  19. 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

  20. 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)

  1. COMBINED UNCOVERED SHEET-AND-TUBE PVT-COLLECTOR SYSTEM WITH BUILT-IN STORAGE WATER HEATER

    Directory of Open Access Journals (Sweden)

    Muhammad Abid

    2012-02-01

    Full Text Available This work describes the design and investigation of a simple combined uncovered sheet-and-tube photo-voltaic-thermal (PVT collector system. The PVT-collector system consists of a support, standard PV module (1.22x0.305m, area=0.37m2, fill factor=0.75, sheet-and-tube water collector and storage tank-heater. The collector was fixed under PV module. Inclination angle of the PVT-collector to the horizontal plane was 45 degree. The storage tank-heater played double role i.e. for storage of hot water and for water heating. The PVT-collector system could work in the fixed and tracking modes of operation. During investigations of PVT-collector in natural conditions, solar irradiance, voltage and current of PV module, ambient temperature and water temperature in storage tank were measured. Average thermal and electrical powers of the PVT-collector system at the tracking mode of operation observed were 39W and 21W, with efficiencies of 15% and 8% respectively at the input power of 260W. The maximum temperature of the water obtained was 42oC. The system was observed efficient for low-temperature applications. The PVT-collector system may be used as a prototype for design of PVT-collector system for domestic application, teaching aid and for demonstration purposes.

  2. 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.

  3. The Stardust Interstellar Dust Collector and Stardust@home

    Science.gov (United States)

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

    2006-12-01

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

  4. Development of an industrialized space-frame system for the support of medium to large solar collector arrays

    Energy Technology Data Exchange (ETDEWEB)

    1982-11-01

    A low-cost industrialized space-frame system suitable for the economical support of medium to large solar collector arrays was designed following a study of building types, collector interface conditions, structural design requirements, and market and procurement factors. The system consists of a series of welded truss modular sections which may be bolted together in the field to create a support structure with a span capability up to 25 m, thus minimizing expensive structural beams and roof penetrations. Collectors can be readily attached to top and bottom channels. The system meets all current government specifications for collector support. A full-size prototype was built to prove the concept and identify any fabrication and on-site assembly problems. Collectors were attached to test collector interface conditions, and a manufacturing strategy developed. 24 figs., 3 tabs.

  5. Experimental evaluation of flat plate solar collector using nanofluids

    International Nuclear Information System (INIS)

    Verma, Sujit Kumar; Tiwari, Arun Kumar; Chauhan, Durg Singh

    2017-01-01

    Highlights: • Solar collectors are special kind of heat exchangers. • Particle concentration is important parameter for thermal conductivity of nanofluid. • Rise of Bejan number indicates systems qualitative response. • Multi walled carbon nanotube is best performing. - Abstract: The present analysis focuses on a wide variety of nanofluids for evaluating performance of flat plate solar collector in terms of various parameters as well as in respect of energy and exergy efficiency. Also, based on our experimental findings on varying mass flow rate, the present investigation has been conducted with optimum particle volume concentration. Experiments indicate that for ∼0.75% particle volume concentration at a mass flow rate of 0.025 kg/s, exergy efficiency for Multi walled carbon nanotube/water nanofluid is enhanced by 29.32% followed by 21.46%, 16.67%, 10.86%, 6.97% and 5.74%, respectively for Graphene/water, Copper Oxide water, Aluminum Oxide/water, Titanium oxide/water, and Silicon Oxide/water respectively instead of water as the base fluid. Entropy generation, which is a drawback, is also minimum in Multiwalled carbon nanotube/water nanofluids. Under the same thermophysical parameters, the maximum drop in entropy generation can be observed in Multiwalled carbon nanotube/water, which is 65.55%, followed by 57.89%, 48.32%, 36.84%, 24.49% and 10.04%, respectively for graphene/water, copper oxide/water, Aluminum/water, Titanium Oxide /water, and Silicon oxide /water instead of water as the base fluid. Rise of Bejan number towards unity emphasizes improved system performance in terms of efficient conversion of the available energy into useful functions. The highest rise in energy efficiency of a collector has been recorded in Multiwalled carbon nanotube/water, which is 23.47%, followed by 16.97%, 12.64%, 8.28%, 5.09% and 4.08%, respectively for graphene/water, Copper oxide/water, Aluminum oxide/water, Titanium oxide /water, and Silicon oxide/water instead of

  6. Review of state-of-the-art of solar collector corrosion processes. Task 1 of solar collector studies for solar heating and cooling applications. Final technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Clifford, J E; Diegle, R B

    1980-04-11

    The state-of-the-art of solar collector corrosion processes is reviewed, and Task 1 of a current research program on use of aqueous heat transfer fluids for solar heating and cooling is summarized. The review of available published literature has indicated that lack of quantitative information exists relative to collector corrosion at the present time, particularly for the higher temperature applications of solar heating and cooling compared to domestic water heating. Solar collector systems are reviewed from the corrosion/service life viewpoint, with emphasis on various applications, collector design, heat transfer fluids, and freeze protection methods. Available information (mostly qualitative) on collector corrosion technology is reviewed to indicate potential corrosion problem areas and corrosion prevention practices. Sources of limited quantitative data that are reviewed are current solar applications, research programs on collector corrosion, and pertinent experience in related applications of automotive cooling and non-solar heating and cooling. A data bank was developed to catalog corrosion information. Appendix A of this report is a bibliography of the data bank, with abstracts reproduced from presently available literature accessions (about 220). This report is presented as a descriptive summary of information that is contained in the data bank.

  7. Experimental Evaluation of a Flat Plate Solar Collector Under Hail City Climate

    Directory of Open Access Journals (Sweden)

    N. Ben Khedher

    2018-04-01

    Full Text Available Flat plate solar water heaters are widely used for water heating in low-temperature residential applications. In this paper the thermal performance of a solar flat plate water heater under Hail weather conditions (latitude 27°52΄N longitude ‎41°69΄E was experimentally investigated. Fluid was circulated through the imbedded copper tubes in the flat plate collector and inlet and outlet temperatures of the fluid were noted at five minute intervals. The experimental-time was between 9:00AM-15:00PM. A study was carried out experimentally to present the efficiency curves of a flat plate solar collector at different flow rates. ASHRAE standard 93-2003 was followed for calculation of instantaneous efficiency of solar collector. Result shows that the flow rate of the circulating fluid highly influence the thermal efficiency of the solar collector. Optimum flow rate of 2.5L/min leads to maximum collector efficiency.

  8. Development of a composite collector scheme for flotation of chalcopyrite ore

    International Nuclear Information System (INIS)

    Khan, M.M.; Ahmad, I.

    2005-01-01

    Xanthate-type collectors reported for the upgradation of Chalcopyrite ore of North Waziristan area were studied and a new technique was developed, in which -two collectors were used (composite collectors) in the bulk-stage process of froth-flotation to achieve metallurgical grade with maximum recovery. The collectors studied were thiol-type surfactants, such as sodium ethyl xanthate (NaEX), sodium propyl xanthate (NaPX), sodium butyl xanthate (NaBX) and sodium Amyl xanthate (NaAX). Mixed collectors examined were in the varying dosage ratio of (0-100:100-0) through the combination of(i) sodium ethyl xanthate with sodium propyl xanthate, sodium ethyl xanthate with sodium butyl xanthate, sodium ethyl xanthate with sodium amyl xanthate, (ii) sodium propyl xanthate with sodium butyl xanthate, sodium propyl xanthate with sodium amyl xanthate and (iii) sodium butyl xanthate with sodium amyl xanthate. All the remaining flotation parameters were kept constant during the various flotation tests. The results were compared and the conclusions were drawn that the optimum grade in the concentrate was obtained with a mixture having a ratio of 4: 1 with sodium ethyl xanthate and sodium butyl xanthate. Recovery of copper content in the concentrate was achieved with ratio of 2:3 with sodium butyl xanthate and sodium amyl xanthate. (author)

  9. 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...

  10. 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.

  11. 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)

  12. 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.

  13. 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

  14. Theory and experimental study of biased charge collector for measuring HPIB

    International Nuclear Information System (INIS)

    He Xiaoping; Wang Haiyang; Sun Jianfeng; Yang Hailiang; Qiu Aici; Tang Junping; Li Jingya; Li Hongyu

    2004-01-01

    Structure of the biased charge collector for measuring HPIB (High-power ion beam) is introduced in this paper. The inner charge propagation process of HPIB in the biased charge collector was simulated with KARAT PIC code. The simulation results indicated that charge was neutralized but current was not neutralized in the biased charge collector. The influence of biased voltage and aperture diameter were also simulated. A -800V biased voltage can meet the requirement for measuring 500 keV HPIB, and this is consistent with the experimental results

  15. 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.

  16. Copper hypersensitivity

    DEFF Research Database (Denmark)

    Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

    2014-01-01

    hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common...

  17. Fabrication and Final Field Tuning of Copper Cavity Models for a High-Current SRF ERL at 703.75 MHz

    CERN Document Server

    Cole, Michael; Burger, Al; Falletta, Michael; Holmes, Douglas; Peterson, Ed; Wong, Robert

    2005-01-01

    Advanced Energy Systems is currently under contract to BNL to fabricate a five cell superconducting cavity and cryomodule for the RHIC eCooler SRF Energy Recovery Linac (ERL) program.* The cavity is designed and optimized for ampere class SRF ERL service. As part of this program, we have fabricated two low power copper models of the RF cavities. During the fabrication process a series of frequency measurements were made and compared to the frequency expected at that point in the fabrication process. Where possible, the cavity was modified either before or during, the next fabrication step to tune the cavity frequency toward the target frequency. Following completion of the cavities they were tuned for field flatness and frequency. This paper will review the measurements made, frequency tuning performed, and discuss discrepancies between the expected and measured results. We will also review the as fabricated field profiles and the results of the tuning steps. Further, the cost and benefits of extensive in pro...

  18. Properties of Al2O3 nano-particle reinforced copper matrix composite coatings prepared by pulse and direct current electroplating

    International Nuclear Information System (INIS)

    Allahkaram, Saeed Reza; Golroh, Setareh; Mohammadalipour, Morteza

    2011-01-01

    Highlights: → The influence of Al 2 O 3 is studied on morphologies of the DC and PC applied coatings. → The influence of Al 2 O 3 is studied on the DC and PC coating thicknesses. → The influence of Al 2 O 3 is studied on wear resistance. → The effect of Al 2 O 3 is studied on the porosity and corrosion resistance. -- Abstract: Cu-Al 2 O 3 nano-composite coatings have high potential for use in applications in which high mechanical properties together with high corrosion resistance are required. In the present study it is intended to produce copper nano-alumina composite coatings with various nano-alumina contents in order to investigate the effect of alumina reinforcement particles on corrosion resistance and mechanical properties such as hardness and wear resistance. The composite coatings were deposited using direct current (DC) and pulse current (PC) plating. The microstructures of the coatings produced from both methods were examined via scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The wear behaviors, micro hardness, coating thickness, corrosion rate and coating porosity were examined using appropriate methods. Compared to DC deposition, PC plating facilitated higher amounts of particle incorporation with more uniform distribution. The results indicated that the mechanical properties of the applied coatings with incorporated nano-alumina reinforcement were far more superior as compared to its own matrix as well as non-composite copper coatings. It was also found out that increasing the amount of nano-alumina content in the coating, led to enhanced general properties of the coatings.

  19. Experimental investigation of a solar collector integrated with a pulsating heat pipe and a compound parabolic concentrator

    International Nuclear Information System (INIS)

    Xu, Rong Ji; Zhang, Xiao Hui; Wang, Rui Xiang; Xu, Shu Hui; Wang, Hua Sheng

    2017-01-01

    Highlights: • Solar collector integrates compound parabolic concentrator and pulsating heat pipe. • Concentrator of a concentration ratio 3.4 matches well heat flux of heat pipe. • Solar collector efficiency increases with decreasing absorber thermal resistance. • Maximum 50% efficiency of the integrated solar collector has been achieved. - Abstract: The paper reports an experimental investigation of a newly proposed solar collector that integrates a closed-end pulsating heat pipe (PHP) and a compound parabolic concentrator (CPC). The PHP is used as an absorber due to its simple structure and high heat transfer capacity. The CPC has a concentration ratio of 3.4 and can be readily manufactured by three-dimensional printing. The CPC can significantly increase the incident solar irradiation intensity to the PHP absorber and also reduce the heat loss due to the decrease in the area of the hot surface. A prototype of the solar collector has been built, consisting of a PHP absorber bent by 4 mm diameter copper tube, CPC arrayed by 10 × 2 CPC units with the collection area of 300 × 427.6 mm 2 , a hot water tank and a glass cover. HFE7100 was utilized as the working fluid at a filling ratio of 40%. The operating characteristics and thermal efficiency of the solar collector were experimentally studied. The steady and periodic temperature fluctuations of the evaporation and condensation sections of the PHP absorber indicate that the absorber works well with a thermal resistance of about 0.26 °C/W. It is also found that, as the main factor to the the thermal performance of the collector, thermal resistance of the PHP absorber decreases with increasing evaporation temperature. The collector apparently shows start-up, operational and shutdown stages at the starting and ending temperatures of 75 °C. When the direct normal irradiance is 800 W/m 2 , the instantaneous thermal efficiency of the solar collector can reach up to 50%.

  20. 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.

  1. Characterization of gold and nickel coating on AISI 304 stainless steel for use in the fabrication of current collector plates for fuel cells; Caracterizacion de recubrimientos de oro y niquel realizados sobre acero inoxidable AISI 304 para su empleo en la fabricacion de placas colectoras de corriente para celdas de combustible

    Energy Technology Data Exchange (ETDEWEB)

    Flores Hernandez, J. Roberto [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)] e-mail: jrflores@iie.org.mx; Aguilar Gama, M. Tulio [UNAM. Facultad de Quimica, Mexico D.F. (Mexico); Cano Castillo, Ulises; Albarran, Lorena [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Olvera, J. Carlos; Orozco, German [CIDETEQ, Pedro Escobedo, Queretaro (Mexico)

    2009-09-15

    Among the different components that compose fuel cell technology (MEA, bipolar plates, seals, etc.) current collector plates play an important role in the good performance of fuel cells, since they collect all of the current generated and distribute it to the external circuit. Therefore, the most important properties that the current collector plates should have are excellent conductivity and good resistance to the corrosive conditions present in the fuel cell. This document presents results obtained during the nickel and gold electrodeposition process on AISI 304 stainless steel and the morphology and thickness of each coating, their adhesion, hardness and conductivity values. Finally, results obtained during some of the electrochemical tests performed on the coatings are shown. [Spanish] De los diferentes componentes que integran la tecnologia de celdas de combustible (MEA's, placas bipolares, sellos, etc.), las placas colectoras de corriente tienen un importante rol en el buen desempeno de la celdas de combustibles, ya que en estas placas se colecta toda la corriente generada y se distribuye al circuito externo. Debido a esto, las propiedades mas importantes que deben tener las placas colectaras de corriente son: excelente conductividad y buena resistencia a las condiciones corrosivas presentes en la celda de combustible. En este documento se presentan los resultados obtenidos en el proceso de electrodeposicion de niquel y oro sobre acero inoxidable AISI 304, asi como la morfologia y el espesor de cada recubrimiento, sus valores de adherencia, dureza y conductividad. Finalmente se muestran tambien los resultados obtenidos de algunas pruebas electroquimicas a los que fueron sometidos los recubrimientos.

  2. GC^2: A Generational Conservative Garbage Collector for the ATerm Library

    OpenAIRE

    Moreau , Pierre-Etienne; Zendra , Olivier

    2002-01-01

    The ATerm library is a well-designed and well-known library in the term rewriting community. In this paper, we discuss the current garbage collector provided with the library and stress the fact that some peculiarities of this functional library could be taken advantage of by the memory management system. We explain how we designed and implemented GC², a new mark-and-sweep generational garbage collector for the ATerm library that builds upon these peculiarities. Experimental results on variou...

  3. The first preliminary experiments on an 84 GHz gyrotron with a single-stage depressed collector

    International Nuclear Information System (INIS)

    Shimozuma, T.; Sato, M.; Takita, Y.

    1997-10-01

    We fabricated and tested an 84GHz gyrotron with a single-stage depressed collector. The gyrotron has a high-voltage insulating section made of a low loss silicon nitride composite. In this preliminary experiment in the depressed collector configuration, we obtained 591kW, 41% operation with a depression voltage of 22.5kV. Access to the higher efficiency region was inhibited by an increase in anode current. (author)

  4. 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.

  5. 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)

  6. 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.

  7. 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

  8. Human copper transporter 2 is localized in late endosomes and lysosomes and facilitates cellular copper uptake

    NARCIS (Netherlands)

    Berghe, van den P.V.E; Folmer, D.E.; Malingré, H.E.M.; Beurden, van E.; Klomp, A.E.M.; Sluis, van de B.; Merkx, M.; Berger, R.J.; Klomp, L.W.J.

    2007-01-01

    High-affinity cellular copper uptake is mediated by the CTR (copper transporter) 1 family of proteins. The highly homologous hCTR (human CTR) 2 protein has been identified, but its function in copper uptake is currently unknown. To characterize the role of hCTR2 in copper homoeostasis,

  9. 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)

  10. 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

  11. A high absorbance material for solar collectors' applications

    International Nuclear Information System (INIS)

    Oliva, A I; Maldonado, R D; Díaz, E A; Montalvo, A I

    2013-01-01

    In this work, we proposed a low cost material to be used as an excellent absorber for solar collectors, to increase its thermal efficiency by the high capacity to absorb solar radiation. The material, known as 'smoke black' (soot) can be obtained by the incomplete combustion of organic materials, such as the oxygen-acetylene, paraffin, or candles. A comparative analysis between the optical properties (reflectance, absorbance, and emissivity) measured on three covered copper surfaces (without paint, with a commercial matte black paint, and with smoke black) shows amazing optical results for the smoke black. Reflectance values of the smoke black applied over copper surfaces improves 56 times the values obtained from commercial black paints. High values of emissivity (E=0.9988) were measured on the surface covered with smoke black by spectrophotometry in the UV-VIS range, which represents about 7% of increment as compared with the value obtained for commercial black paints (E=0.938). The proposed high absorbance material can be easily applied on any kind of surfaces at low cost.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. Thermal efficiency of low cost solar collectors - CSBC; Eficiencia termica de coletores solares de baixo custo - CSBC

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Renato C.; Shiota, Robson T.; Mello, Samuel F.; Assis Junior, Valdir; Bartoli, Julio R. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Quimica. Dept. de Tecnologia de Polimeros

    2006-07-01

    The thermal performance of a low cost flat panel solar collector was measured. This Low Cost Solar Collector is a novel concept for water heating using only thermoplastics materials, used on building: ceiling and tubes made of unplasticized PVC, but without transparent cover. The top side of the UPVC panel was black painted to be the solar radiation absorber surface. Prototypes were installed on two charity houses around Campinas and at the FEQ campus, being used without any trouble for one year. The thermal efficiency analysis followed ABNT NBR 10184 standard at the Green-Solar Laboratory, Brazilian Centre for Development of Solar Thermal Energy, PUC-Minas. It was measured a thermal efficiency of 67%, compared to the 75% usually found on conventional solar collectors made of copper tubes and with glass cover. (author)

  17. Towards the optimization of the thermal–hydraulic performance of gyrotron collectors

    Energy Technology Data Exchange (ETDEWEB)

    Savoldi, Laura; Bertani, Cristina [Dipartimento Energia, Politecnico di Torino, 10129 Torino (Italy); Cau, Francesca; Cismondi, Fabio [F4E, Barcelona (Spain); Gantenbein, Gerd; Illy, Stefan [Karlsruhe Institute of Technology (KIT), Institute for Pulsed Power and Microwave Technology (IHM), Kaiserstr. 12, 76131 Karlsruhe (Germany); Monni, Grazia [Dipartimento Energia, Politecnico di Torino, 10129 Torino (Italy); Rozier, Yoann [Thales Electron Devices, 78141 Vélizy-Villacoublay (France); Zanino, Roberto, E-mail: roberto.zanino@polito.it [Dipartimento Energia, Politecnico di Torino, 10129 Torino (Italy)

    2015-11-15

    Different configurations of water-cooled Cu collector for gyrotrons are investigated using the StarCCM + CFD code, aimed at optimizing its thermal–hydraulic (TH) performance. Although the current collectors show a good performance, the collector can be subjected to transient heat loads, due to the spent electron beam, of up to several tens of MW/m{sup 2}, and there is an interest to increase the gyrotron output power in the future. Furthermore, an optimized cooling will lead to improved reliability and lifetime of the collector. Starting from a hypervapotron (HV)-like collector, characterized by 100+ deep rectangular cavities with aspect ratio (AR) = 3, we present in the first part of the paper a single-cavity steady-state parametric analysis of the effect of AR on the heat exhaust capabilities. The investigation is then extended to other collector designs, including circumferential ribs and dimples, in order to assess the options for further improvements of the TH performance. The peak Cu temperature is computed by the code and its minimization is the target of the present optimization exercise. A self-consistent estimate of the heat transfer coefficient between collector and coolant is also obtained, which could be useful for fatigue and lifetime assessments. In the second part of the paper the most promising collector geometries identified in the first part are analyzed in the case of a transient heat load (vertical sweeping), first at the level of a single spatial period of the collector structure, then at the full-collector level. The results of the TH transient analysis are compared with both the results of the first part and with the transient purely thermal analysis of the full collector, showing for all geometries considered in this study a room for cooling efficiency improvement with respect to the HV-like design with AR = 3, at least in the operating conditions considered for this study (V ∼ 4 m/s, almost 100 °C sub-cooling).

  18. 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

  19. Fabrication of cellulose/graphene paper as a stable-cycling anode materials without collector.

    Science.gov (United States)

    Zhang, Chunliang; Cha, Ruitao; Yang, Luming; Mou, Kaiwen; Jiang, Xingyu

    2018-03-15

    Flexible and foldable devices attract substantial attention in low-cost electronics. Among the flexible substrate materials, paper has several attractive advantages. In our study, we fabricate cellulose/graphene paper by wet end formation (papermaking). The cationic polyacrylamide remarkably improve the retention ratio of graphene of cellulose/graphene slurry. Besides, cellulose/graphene paper exhibits well mechanical properties such as its flexibility and folding endurance. And we replace copper foil collector with cellulose/graphene paper in lithium-ion batteries without collector, and investigate its electrochemical properties. The obtained results show that cellulose/graphene paper presents excellent charge-discharge stability after 1600th cycles as the anode of lithium-ion batteries. These advantages highlight the potential applications of cellulose/graphene paper as anode materials for lithium-ion batteries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. EXPERIMENTAL RESEARCH OF THE INFLUENCE OF VARIOUS TYPES OF SOLAR COLLECTORS FOR PERFORMANCE SOLAR DESALINATION PLANT

    Directory of Open Access Journals (Sweden)

    Rakhmatulin I.R.

    2014-04-01

    Full Text Available The article discusses the possibility of using renewable energy for water purification. Results of analysis of a preferred energy source for a water purification using installed in places where fresh water shortages and a lack of electrical energy. The possibility of desalination of salt water using solar energy for regions with temperate climate. Presented desalination plant working on energy vacuum solar collectors, principles of action developed by the desalination plant. The experimental results of a constructed distiller when working with vacuum glass tubes and vacuum tubes with copper core inside. Conclusions about the possibility of using solar collectors for water desalination, are tips and tricks to improve the performance of solar desalination plant.

  1. 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.

  2. 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)

  3. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  4. Activation of Sphalerite by Ammoniacal Copper Solution in Froth Flotation

    Directory of Open Access Journals (Sweden)

    Xian Xie

    2016-01-01

    Full Text Available The activation of sphalerite particles by ammoniacal copper solution (ACS was investigated in this study. This microflotation study was conducted on a single sphalerite mineral with the particles size of 38 μm to 75 μm. Results showed that ACS has somewhat better activation effect than copper sulphate (a traditional activator with sodium isobutyl xanthate as the collector. Agglomeration observation, contact angle measurement, and X-ray photoelectron spectroscopy measurement results of sphalerite particles verified the superiority of this new activator. Therefore, the substitution of copper sulphate with ACS would increase the separation efficiency not only in marmatite flotation but also in sphalerite flotation.

  5. 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...

  6. 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)

  7. 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...

  8. 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.

  9. 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.

  10. Characterization and recovery of copper values from discarded slag.

    Science.gov (United States)

    Das, Bisweswar; Mishra, Barada Kanta; Angadi, Shivakumar; Pradhan, Siddharth Kumar; Prakash, Sandur; Mohanty, Jayakrushna

    2010-06-01

    In any copper smelter large quantities of copper slag are discarded as waste material causing space and environmental problems. This discarded slag contains important amounts of metallic values such as copper and iron. The recovery of copper values from an Indian smelter slag that contains 1.53% Cu, 39.8% Fe and 34.65% SiO(2) was the focus of the present study. A complete investigation of the different phases present in the slag has been carried out by means of optical microscopy, Raman spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques. It is observed that iron and silica are mostly associated with the fayalite phase whereas copper is present in both oxide and sulfide phases. These oxide and sulfide phases of copper are mostly present within the slag phase and to some extent the slag is also embedded inside the oxide and sulfide phases. The recovery of copper values from the discarded slag has been explored by applying a flotation technique using conventional sodium isopropyl xanthate (SIX) as the collector. The effects of flotation parameters such as pH and collector concentration are investigated. Under optimum flotation conditions, it is possible to achieve 21% Cu with more than 80% recovery.

  11. 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.

  12. 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....

  13. 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)

  14. 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.

  15. 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.

  16. Copper Test

    Science.gov (United States)

    ... in the arm and/or a 24-hour urine sample is collected. Sometimes a health practitioner performs a liver ... disease , a rare inherited disorder that can lead to excess storage of copper in the liver, brain, and other ...

  17. Thermal and optical study of parabolic trough collectors of Shiraz solar power plant

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari, A.; Yaghoubi, M.; Vadiee, A.; Hessami, R. [Shiraz Univ, Shiraz (Iran, Islamic Republic of); Kanan, P. [Renewable Energy Organization of Iran, Tehran (Iran, Islamic Republic of)

    2007-07-01

    The construction of the first 250 KW solar power plant in Shiraz, Iran was discussed. The power plant is comprised of a steam and oil cycle which includes 48 parabolic trough collectors (PTCs). Solar thermal power plants based on PTCs are currently the most successful solar technologies for electricity generation. These power plants are basically composed of a solar collector field and a power block. The solar collector field is designed to collect heat from the sun which it is continuously tracking. The reflecting surface concentrates direct solar radiation in the optical focal line of the collector where the heat collecting element (HCE) is located. The HCE absorbs the reflected energy and transmits it to the heat transfer fluid which is pumped to the conventional power block where electricity is generated. There is potential to significantly increase the performance and reduce the cost of PTC solar thermal electric technologies. However, it is necessary to characterize the optical performance and determine the optical losses of PTCs in order to improve the optical efficiency of these systems and to ensure the desired power quality. In this study, thermocouple sensors were used to record the collector oil inlet and outlet temperature along with the ambient temperature in the PTCs. In addition to measuring the wind speed, the solar beam radiation intensity was measured along with the oil's mass flow rate. All parameters were measured as a function of time. Based on these measurements, the intercept factor value and collector's incidence angle was determined and compared with other large size constructed commercial parabolic collectors. The maximum beam radiation during the experimental period was 735 2mW. The useful heat gain and the collector's instantaneous efficiency as a whole was evaluated on an hourly basis. All these parameters were strongly influenced by the incident beam radiation and found to follow each other. The optical and thermal

  18. Compendium of information on identification and testing of materials for plastic solar thermal collectors

    Energy Technology Data Exchange (ETDEWEB)

    McGinniss, V.D.; Sliemers, F.A.; Landstrom, D.K.; Talbert, S.G.

    1980-07-31

    This report is intended to organize and summarize prior and current literature concerning the weathering, aging, durability, degradation, and testing methodologies as applied to materials for plastic solar thermal collectors. Topics covered include (1) rate of aging of polymeric materials; (2) environmental factors affecting performance; (3) evaluation and prediction of service life; (4) measurement of physical and chemical properties; (5) discussion of evaluation techniques and specific instrumentation; (6) degradation reactions and mechanisms; (7) weathering of specific polymeric materials; and (8) exposure testing methodology. Major emphasis has been placed on defining the current state of the art in plastics degradation and on identifying information that can be utilized in applying appropriate and effective aging tests for use in projecting service life of plastic solar thermal collectors. This information will also be of value where polymeric components are utilized in the construction of conventional solar collectors or any application where plastic degradation and weathering are prime factors in material selection.

  19. 22.5% efficient silicon heterojunction solar cell with molybdenum oxide hole collector

    Energy Technology Data Exchange (ETDEWEB)

    Geissbühler, Jonas, E-mail: jonas.geissbuehler@epfl.ch; Werner, Jérémie; Martin de Nicolas, Silvia; Hessler-Wyser, Aïcha; Tomasi, Andrea; Niesen, Bjoern; De Wolf, Stefaan [Photovoltaics and Thin Film Electronics Laboratory, Institute of Microengineering (IMT), École Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000 Neuchâtel (Switzerland); Barraud, Loris; Despeisse, Matthieu; Nicolay, Sylvain [CSEM PV-Center, Jaquet-Droz 1, CH-2000 Neuchâtel (Switzerland); Ballif, Christophe [Photovoltaics and Thin Film Electronics Laboratory, Institute of Microengineering (IMT), École Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, CH-2000 Neuchâtel (Switzerland); CSEM PV-Center, Jaquet-Droz 1, CH-2000 Neuchâtel (Switzerland)

    2015-08-24

    Substituting the doped amorphous silicon films at the front of silicon heterojunction solar cells with wide-bandgap transition metal oxides can mitigate parasitic light absorption losses. This was recently proven by replacing p-type amorphous silicon with molybdenum oxide films. In this article, we evidence that annealing above 130 °C—often needed for the curing of printed metal contacts—detrimentally impacts hole collection of such devices. We circumvent this issue by using electrodeposited copper front metallization and demonstrate a silicon heterojunction solar cell with molybdenum oxide hole collector, featuring a fill factor value higher than 80% and certified energy conversion efficiency of 22.5%.

  20. Development of Experimental Superconducting Magnet for the Collector Ring of FAIR Project

    International Nuclear Information System (INIS)

    Zhu Yinfeng; Wu Weiyue; Wu Songtao; Liu Changle; Xu Houchang

    2010-01-01

    A pool cooled experimental magnet based on the copper stabilized NbTi superconducting wire was designed, fabricated and tested, in order to evaluate the engineering design of the dipole superconducting magnet for the collector ring (CR) of the facility for antiproton and ion research (FAIR) project. In this paper, the experimental setup including quench protection system was presented. Performance of the liquid helium pool cooled test was introduced. All of the results indicate both the performance of conductor and the experimental superconducting magnet under low temperature is stable, which suggests the engineering design are feasible for the formal magnet in CR of the FAIR project.

  1. 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).

  2. 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....

  3. 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.

  4. 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....

  5. 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...

  6. 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...

  7. 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...

  8. 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)

  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. Copper tolerance and virulence in bacteria

    Science.gov (United States)

    Ladomersky, Erik; Petris, Michael J.

    2015-01-01

    Copper (Cu) is an essential trace element for all aerobic organisms. It functions as a cofactor in enzymes that catalyze a wide variety of redox reactions due to its ability to cycle between two oxidation states, Cu(I) and Cu(II). This same redox property of copper has the potential to cause toxicity if copper homeostasis is not maintained. Studies suggest that the toxic properties of copper are harnessed by the innate immune system of the host to kill bacteria. To counter such defenses, bacteria rely on copper tolerance genes for virulence within the host. These discoveries suggest bacterial copper intoxication is a component of host nutritional immunity, thus expanding our knowledge of the roles of copper in biology. This review summarizes our current understanding of copper tolerance in bacteria, and the extent to which these pathways contribute to bacterial virulence within the host. PMID:25652326

  11. Background current of radioisotope manometer

    International Nuclear Information System (INIS)

    Vydrik, A.A.

    1987-01-01

    The technique for calculating the main component of the background current of radioisotopic monometers, current from direct collision of ionizing particles and a collector, is described. The reasons for appearance of background photoelectron current are clarified. The most effective way of eliminating background current components is collector protection from the source by a screen made of material with a high gamma-quanta absorption coefficient, such as lead, for example

  12. Electrochemical in-situ impregnation of wood using a copper nail as source for copper

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Block, Thomas; Nymark, Morten

    2011-01-01

    A new method for copper impregnation of wood in structures was suggested and tested in laboratory scale with specimen of new pine sapwood. A copper nail and a steel screw were placed in the wood, and an electric direct current field was applied, so the copper nail was anode and the screw...... was cathode. At the anode, copper ions were generated. The copper ions were transported into the wood by electromigration (movement of ions in an applied electric field) towards the cathode, and a volume between the two electrodes was thereby impregnated. Copper also moved to a lesser degree in the opposite...

  13. Influence of the Interaction between Sphalerite and Pyrite on the Copper Activation of Sphalerite

    Directory of Open Access Journals (Sweden)

    Bo Yang

    2018-01-01

    Full Text Available In this paper, the effect of pyrite on the activation of sphalerite was investigated by micro-flotation, copper adsorption experiments, X-ray photoelectron spectroscopy (XPS, and electrochemical measurement. The micro-flotation test results showed that the recovery and flotation rate of sphalerite with copper sulphate as activator and butyl xanthate as collector were significantly decreased with the increasing content of pyrite in pulp. Cu2+ adsorption results indicated that the adsorption of Cu2+ on the sphalerite surface were decreased when pyrite was present in the pulp. XPS surface analysis demonstrated that the proportion of Cu+ species increased in the activation products on the sphalerite surface, but the total atomic concentration of Cu atom was decreased. Linear voltammetry measurement suggested that the current density of Cu+ species oxidizing to Cu2+ species was increased when sphalerite was electrically contacted with pyrite, which confirmed the increased proportion of Cu+ species on Cu-activation sphalerite surface when contacting with pyrite. These results indicated that there is not only a competitive adsorption for cupric ions (Cu2+, but the galvanic interaction between sphalerite and pyrite also has a significant influence on the copper activation of sphalerite.

  14. 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.

  15. 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

  16. 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.

  17. Performance optimization of evacuated tube collector for solar cooling of a house in hot climate

    Science.gov (United States)

    Ghoneim, Adel A.

    2018-02-01

    Evacuating the space connecting cover and absorber significantly improves evacuated tube collector (ETC) performance. So, ETCs are progressively utilised all over the world. The main goal of current study is to explore ETC thermal efficiency in hot and severe climate like Kuwait weather conditions. A collector test facility was installed to record ETC thermal performance for one-year period. An extensively developed model for ETCs is presented, employing complete optical and thermal assessment. This study analyses separately optics and heat transfer in the evacuated tubes, allowing the analysis to be extended to different configurations. The predictions obtained are in agreement with experimental. The optimum collector parameters (collector tube length and diameter, mass flow rate and collector tilt angle) are determined. The present results indicate that the optimum tube length is 1.5 m, as at this length a significant improvement is achieved in efficiency for different tube diameters studied. Finally, the heat generated from ETCs is used for solar cooling of a house. Results of the simulation of cooling system indicate that an ETC of area 54 m2, tilt angle of 25° and storage tank volume of 2.1 m3 provides 80% of air-conditioning demand in a house located in Kuwait.

  18. Photovoltaic-thermal (PV/T) solar collectors: Features and performance modelling

    International Nuclear Information System (INIS)

    Atienza-Márquez, Antonio; Bruno, Joan Carles; Coronas, Alberto; Korolija, Ivan; Greenough, Richard; Wright, Andy

    2017-01-01

    Currently, the electrical efficiency of photovoltaic (PV) solar cells ranges between 5–25%. One of the most important parameters that affects the electrical efficiency of a PV collector is the temperature of its cells: the higher temperature, the lower is the efficiency. Photovoltaic/thermal (PV/T) technology is a potential solution to ensure an acceptable solar energy conversion. The PV/T technology produces both electrical and thermal energy simultaneously. It is suitable for low temperature applications (25–40 o C) and overall efficiency increases compared to individual collectors. This paper describes an installation in a single-family house where PV/T collectors are coupled with a ground heat exchanger and a heat pump for domestic hot water and space heating purposes. The aim of this work is twofold. First, the features of the PV/T technology are analyzed. Second, a model of a flat-plate PV/T water collector was developed in TRNSYS in order to analyze collectors performance. (author)

  19. Industrial Implementation of Environmentally Friendly Nanometal Electroplating Process for Chromium and Copper Beryllium Replacement using Low Cost Pulse Current Power Supplies

    Science.gov (United States)

    2014-09-10

    FINAL REPORT Industrial Implementation of Environmentally Friendly Nanometal Electroplating Process for Chromium and Copper Beryllium...35 3.2 Phase II – Development/Verification that Nanotechnology Based Electroplating Process to Replace EHC/Cu-Be Processes are Compatible With...36 3.3 Phase III – Development of 200kW Power Supply and Compatible Nanostructured Electroplating Processed for Commercialization

  20. 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.

  1. 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...

  2. Collector modulation in high-voltage bipolar transistor in the saturation mode: Analytical approach

    Science.gov (United States)

    Dmitriev, A. P.; Gert, A. V.; Levinshtein, M. E.; Yuferev, V. S.

    2018-04-01

    A simple analytical model is developed, capable of replacing the numerical solution of a system of nonlinear partial differential equations by solving a simple algebraic equation when analyzing the collector resistance modulation of a bipolar transistor in the saturation mode. In this approach, the leakage of the base current into the emitter and the recombination of non-equilibrium carriers in the base are taken into account. The data obtained are in good agreement with the results of numerical calculations and make it possible to describe both the motion of the front of the minority carriers and the steady state distribution of minority carriers across the collector in the saturation mode.

  3. Effects of nanometric hydrophobic layer on performances of solar photovoltaic collectors

    Directory of Open Access Journals (Sweden)

    Andrei BUTUZA

    2014-11-01

    Full Text Available The study refers to the experimental investigation of solar photovoltaic collectors' behaviour when the glazed surface is treated with a nanometric layer of hydrophobic solution. The experiment was carried out on two photovoltaic collectors, of which one was considered as reference and the other one was coated with a commercial hydrophobic solution. It was studied the evolution of the following electrical parameters: current, voltage, power, efficiency and daily energy production. The voltage was almost unaffected, but for all the others parameters, important drop were recorded. The preliminary conclusion of the study is that the use of hydrophobic solutions, for the treatment of glazed surfaces of solar collectors is not recommended. This hypothesis needs supplementary investigations and measurements in the context of reduced available information concerning the optical properties of hydrophobic solutions.

  4. Performance Investigation and Structure Optimization of a Flat Dual-Function Solar Collector

    Directory of Open Access Journals (Sweden)

    Jinwei Ma

    2015-01-01

    Full Text Available The performance of a dual-function solar collector (DFSC that can work as either water heater or air heater depending on seasonal requirement is investigated via both experimental and numerical approaches in this paper. The numerical results are well consistent with the experimental results. Daily efficiency of the thermosiphon system with DFSC is more than 55% in water heating mode and the instantaneous air heating efficiency of the collector reaches 60%. The effects of inner parameters on the thermal efficiency of the collector are analyzed by numerical simulations of the operation of DFSC in two working modes. It is found that the depths of the two air channels in DFSC have an optimal range suitable for both working modes. The thickness of back insulation should be no less than 0.06 m to prevent heat loss via backboard, and the diameter and number of copper tubes show notable effect on the efficiency of DFSC in water heating mode but slight effect in air heating mode.

  5. Solar Collector Design Optimization: A Hands-on Project Case Study

    Science.gov (United States)

    Birnie, Dunbar P., III; Kaz, David M.; Berman, Elena A.

    2012-01-01

    A solar power collector optimization design project has been developed for use in undergraduate classrooms and/or laboratories. The design optimization depends on understanding the current-voltage characteristics of the starting photovoltaic cells as well as how the cell's electrical response changes with increased light illumination. Students…

  6. TIG source control system when welding point-by-point the elements of the collector

    International Nuclear Information System (INIS)

    Bica, I.

    1997-01-01

    The paper presents a control system designed to equip the mechanized welding installations of the collector winding. The logical function of the technological process is determined the synthesis of the electric current is made, too. The logical circuit is made in the TTL technique. It presents reliability and safety in service. (Author) 3 refs

  7. 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.

  8. 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...

  9. Electrochemical remediation of copper contaminated clay soils

    Energy Technology Data Exchange (ETDEWEB)

    Korolev, V.A.; Babakina, O.A.; Mitojan, R.A. [Moscow State Univ. (Russian Federation)

    2001-07-01

    The study objective focused on electrochemical remediation copper polluted soils in the presence of adjuvant substances and conditions that are more effective for the treatment. Some of these substances were studied in different researches. Moreover, authors obtained a result of extraction copper rate higher than 90%. In this connection the following problems were set: - Influence organic and inorganic substances on copper mobility in soil under the DC current. - Moisture effect on copper migration in clay. - Electrochemical remediation soils different mineralogical composition. - A washing conditions contribution to electrochemical remediation of soil from copper. - Accuracy rating experimental dates. (orig.)

  10. 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.

  11. Methods for measurement of electron emission yield under low energy electron-irradiation by collector method and Kelvin probe method

    Energy Technology Data Exchange (ETDEWEB)

    Tondu, Thomas; Belhaj, Mohamed; Inguimbert, Virginie [Onera, DESP, 2 Avenue Edouard Belin, 31400 Toulouse (France); Onera, DESP, 2 Avenue Edouard Belin, 31400 Toulouse, France and Fondation STAE, 4 allee Emile Monso, BP 84234-31432, Toulouse Cedex 4 (France); Onera, DESP, 2 Avenue Edouard Belin, 31400 Toulouse (France)

    2010-09-15

    Secondary electron emission yield of gold under electron impact at normal incidence below 50 eV was investigated by the classical collector method and by the Kelvin probe method. The authors show that biasing a collector to ensure secondary electron collection while keeping the target grounded can lead to primary electron beam perturbations. Thus reliable secondary electron emission yield at low primary electron energy cannot be obtained with a biased collector. The authors present two collector-free methods based on current measurement and on electron pulse surface potential buildup (Kelvin probe method). These methods are consistent, but at very low energy, measurements become sensitive to the earth magnetic field (below 10 eV). For gold, the authors can extrapolate total emission yield at 0 eV to 0.5, while a total electron emission yield of 1 is obtained at 40{+-}1 eV.

  12. Methods for measurement of electron emission yield under low energy electron-irradiation by collector method and Kelvin probe method

    International Nuclear Information System (INIS)

    Tondu, Thomas; Belhaj, Mohamed; Inguimbert, Virginie

    2010-01-01

    Secondary electron emission yield of gold under electron impact at normal incidence below 50 eV was investigated by the classical collector method and by the Kelvin probe method. The authors show that biasing a collector to ensure secondary electron collection while keeping the target grounded can lead to primary electron beam perturbations. Thus reliable secondary electron emission yield at low primary electron energy cannot be obtained with a biased collector. The authors present two collector-free methods based on current measurement and on electron pulse surface potential buildup (Kelvin probe method). These methods are consistent, but at very low energy, measurements become sensitive to the earth magnetic field (below 10 eV). For gold, the authors can extrapolate total emission yield at 0 eV to 0.5, while a total electron emission yield of 1 is obtained at 40±1 eV.

  13. Collector for recovering gallium from weapons plutonium

    International Nuclear Information System (INIS)

    Philip, C.V.; Anthony, R.G.; Chokkaram, S.

    1998-09-01

    Currently, the separation of gallium from weapons plutonium involves the use of aqueous processing using either solvent extraction of ion exchange. However, this process generates significant quantities of liquid radioactive wastes. A Thermally Induced Gallium Removal process, or TIGR, developed by researchers at Los Alamos National Laboratories, is a simpler alternative to aqueous processing. This research examined this process, and the behavior of gallium suboxide, a vapor that is swept away by passing hydrogen/argon over gallium trioxide/plutonium oxide heated at 1100 C during the TIGR process. Through experimental procedures, efforts were made to prevent the deposition of corrosive gallium onto furnace and vent surfaces. Experimental procedures included three options for gallium removal and collection: (1) collection of gallium suboxide through use of a cold finger; (2) collection by in situ air oxidation; and (3) collection of gallium on copper. Results conclude all three collection mechanisms are feasible. In addition, gallium trioxide exists in three crystalline forms, and each form was encountered during each experiment, and that each form will have a different reactivity

  14. 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

  15. 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.

  16. New materials for polymer electrolyte membrane fuel cell current collectors

    Science.gov (United States)

    Hentall, Philip L.; Lakeman, J. Barry; Mepsted, Gary O.; Adcock, Paul L.; Moore, Jon M.

    Polymer Electrolyte Membrane Fuel cells for automotive applications need to have high power density, and be inexpensive and robust to compete effectively with the internal combustion engine. Development of membranes and new electrodes and catalysts have increased power significantly, but further improvements may be achieved by the use of new materials and construction techniques in the manufacture of the bipolar plates. To show this, a variety of materials have been fabricated into flow field plates, both metallic and graphitic, and single fuel cell tests were conducted to determine the performance of each material. Maximum power was obtained with materials which had lowest contact resistance and good electrical conductivity. The performance of the best material was characterised as a function of cell compression and flow field geometry.

  17. 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...

  18. Structural evaluation of a DTHR bundle divertor particle collector

    International Nuclear Information System (INIS)

    Prevenslik, T.V.

    1980-09-01

    The purpose of this report is to present a structural evaluation of the current bundle divertor particle collector BDPC design under a peak heat flux in relation to criteria that protect against coolant leakage into the plasma over replacement schedules planned during DTHR operation. In addition, an assessment of the BDPC structural integrity at higher heat fluxes is presented. Further, recommendations for modifications in the current BDPC design that would improve design reliability to be considered in future design studies are described. Finally, experimental test programs directed to establishing materials data necessary in providing greater confidence in subsequent structural evaluations of BDPC designs in relation to coolant leakage over planned replacement schedules are identified

  19. Gallium and copper radiopharmaceutical chemistry

    International Nuclear Information System (INIS)

    Green, M.A.

    1991-01-01

    Gallium and copper radionuclides have a long history of use in nuclear medicine. Table 1 presents the nuclear properties of several gallium and copper isotopes that either are used in the routine practice of clinical nuclear medicine or exhibit particular characteristics that might make them useful in diagnostic or therapeutic medicine. This paper will provide some historic perspective along with an overview of some current research directions in gallium and copper radiopharmaceutical chemistry. A more extensive review of gallium radiopharmaceutical chemistry has recently appeared and can be consulted for a more in-depth treatment of this topic

  20. 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...

  1. 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.

  2. 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...

  3. Treatment of copper ores containing atacamite by the brisa process

    International Nuclear Information System (INIS)

    Carranza, F.; Mazuelos, A.; Romero, R.

    2003-01-01

    The current treatment of copper ores containing atacamite and secondary copper sulphides consists of heap leaching, by the TL process. copper recoveries by this treatment are very low (less than 50% for operating times higher than six months). In order to improve the copper extraction yields, several treatment options are presented in this work, wich consist on promoting the acid leaching of the atacamite and the indirect bio leaching (Brisk process) of the secondary copper sulphides. All the options lead to improved copper recoveries in comparison with the current treatment. An economic estimation of each option of treatment is included, with really attractive results. (Author) 13 refs

  4. A hybrid air conditioner driven by a hybrid solar collector

    Science.gov (United States)

    Al-Alili, Ali

    The objective of this thesis is to search for an efficient way of utilizing solar energy in air conditioning applications. The current solar Air Conditioners (A/C)s suffer from low Coefficient of Performance (COP) and performance degradation in hot and humid climates. By investigating the possible ways of utilizing solar energy in air conditioning applications, the bottlenecks in these approaches were identified. That resulted in proposing a novel system whose subsystem synergy led to a COP higher than unity. The proposed system was found to maintain indoor comfort at a higher COP compared to the most common solar A/Cs, especially under very hot and humid climate conditions. The novelty of the proposed A/C is to use a concentrating photovoltaic/thermal collector, which outputs thermal and electrical energy simultaneously, to drive a hybrid A/C. The performance of the hybrid A/C, which consists of a desiccant wheel, an enthalpy wheel, and a vapor compression cycle (VCC), was investigated experimentally. This work also explored the use of a new type of desiccant material, which can be regenerated with a low temperature heat source. The experimental results showed that the hybrid A/C is more effective than the standalone VCC in maintaining the indoor conditions within the comfort zone. Using the experimental data, the COP of the hybrid A/C driven by a hybrid solar collector was found to be at least double that of the current solar A/Cs. The innovative integration of its subsystems allows each subsystem to do what it can do best. That leads to lower energy consumption which helps reduce the peak electrical loads on electric utilities and reduces the consumer operating cost since less energy is purchased during the on peak periods and less solar collector area is needed. In order for the proposed A/C to become a real alternative to conventional systems, its performance and total cost were optimized using the experimentally validated model. The results showed that for an

  5. Synthesis and characterization of Eichhornia-mediated copper oxide ...

    Indian Academy of Sciences (India)

    In this paper, we report the biosynthesis and characterization of copper oxide nanoparticles ... copper oxide nanoparticles by simple, cost-effective and ecofriendly method as an alternative to other available ... Currently, zinc oxide, gold, silver.

  6. 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.

  7. 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.

  8. Hypoxia targeting copper complexes

    International Nuclear Information System (INIS)

    Dearling, J.L.

    1998-11-01

    The importance and incidence of tumour hypoxia, its measurement and current treatments available, including pharmacological and radiopharmacological methods of targeting hypoxia, are discussed. A variety of in vitro and in vivo methods for imposing hypoxia have been developed and are reviewed. Copper, its chemistry, biochemistry and radiochemistry, the potential for use of copper radionuclides and its use to date in this field is considered with particular reference to the thiosemicarbazones. Their biological activity, metal chelation, in vitro and in vivo studies of their radiocopper complexes and the potential for their use as hypoxia targeting radiopharmaceuticals is described. The reduction of the copper(II) complex to copper(l), its pivotal importance in their biological behaviour, and the potential for manipulation of this to effect hypoxia selectivity are described. An in vitro method for assessing the hypoxia selectivity of radiopharmaceuticals is reported. The rapid deoxygenation and high viability of a mammalian cell culture in this system is discussed and factors which may affect the cellular uptake of a radiopharmaceutical are described. The design, synthesis and complexation with copper and radiocopper of a range of bis(thiosemicarbazones) is reported. Synthesis of these compounds is simple giving high yields of pure products. The characteristics of the radiocopper complexes ( 64 Cu) including lipophilicity and redox activity are reported (reduction potentials in the range -0.314 - -0.590 V). High cellular uptakes of the radiocopper complexes of the ligands, in hypoxic and normoxic EMT6 and CHO320 cells, were observed. Extremes of selectivity are shown ranging from the hypoxia selective 64 Cu(II)ATSM to normoxic cell selective 64 Cu(II)GTS. The selectivities observed are compared with the physico chemical characteristics of the complexes. A good correlation exists between selectivity of the complex and its Cu(II)/Cu(I) reduction potential, with hypoxia

  9. 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

  10. 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

  11. High-efficiency helical traveling-wave tube with dynamic velocity taper and advanced multistage depressed collector

    Science.gov (United States)

    Curren, Arthur N.; Palmer, Raymond W.; Force, Dale A.; Dombro, Louis; Long, James A.

    A NASA-sponsored research and development contract has been established with the Watkins-Johnson Company to fabricate high-efficiency 20-watt helical traveling wave tubes (TWTs) operating at 8.4 to 8.43 GHz. The TWTs employ dynamic velocity tapers (DVTs) and advanced multistage depressed collectors (MDCs) having electrodes with low secondary electron emission characteristics. The TWT designs include two different DVTs; one for maximum efficiency and the other for minimum distortion and phase shift. The MDC designs include electrodes of untreated and ion-textured graphite as well as copper which has been treated for secondary electron emission suppression. Objectives of the program include achieving at least 55 percent overall efficiency. Tests with the first TWTs (with undepressed collectors) indicate good agreement between predicted and measured RF efficiencies with as high as 30 percent improvement in RF efficiency over conventional helix designs.

  12. High-efficiency helical traveling-wave tube with dynamic velocity taper and advanced multistage depressed collector

    Science.gov (United States)

    Curren, Arthur N.; Palmer, Raymond W.; Force, Dale A.; Dombro, Louis; Long, James A.

    1987-01-01

    A NASA-sponsored research and development contract has been established with the Watkins-Johnson Company to fabricate high-efficiency 20-watt helical traveling wave tubes (TWTs) operating at 8.4 to 8.43 GHz. The TWTs employ dynamic velocity tapers (DVTs) and advanced multistage depressed collectors (MDCs) having electrodes with low secondary electron emission characteristics. The TWT designs include two different DVTs; one for maximum efficiency and the other for minimum distortion and phase shift. The MDC designs include electrodes of untreated and ion-textured graphite as well as copper which has been treated for secondary electron emission suppression. Objectives of the program include achieving at least 55 percent overall efficiency. Tests with the first TWTs (with undepressed collectors) indicate good agreement between predicted and measured RF efficiencies with as high as 30 percent improvement in RF efficiency over conventional helix designs.

  13. Thermal and hydraulic analysis of multilayered asphalt pavements as active solar collectors

    International Nuclear Information System (INIS)

    Pascual-Muñoz, P.; Castro-Fresno, D.; Serrano-Bravo, P.; Alonso-Estébanez, A.

    2013-01-01

    Highlights: • A new type of asphalt solar collector has been introduced in this paper. • The common pipe network has been replaced for a highly porous asphalt layer. • The use of these collectors contributes to achieve current environmental targets. • Excellent thermal efficiencies have been obtained in the laboratory tests. • Further research is needed to increase the low flow rates achieved. - Abstract: The fulfillment of current environmental aims like reducing fossil fuel consumption or greenhouse gas emissions entails the development of new technologies that enable the use of cleaner, cheaper and renewable energies. Furthermore, the need to improve energy efficiency in buildings encourages scientists and engineers to find new ways of harvesting energy for later uses. The use of asphalt pavements as active solar collectors is introduced in this article. Several authors have studied the use of roads as an energy source before. However, a new technology is presented in which a multilayered pavement with a highly porous middle layer is used instead of a solar collector with an embedded pipe network. These collectors are fully integrated within the road infrastructure and may offer low cost solar energy for water heating. The paper includes a brief comment on the state-of-the-art. Then, a broad methodology is presented in which data, materials and procedures needed to run the tests are fully described. Finally, the results of the laboratory tests are stated and discussed. The prototype used in the laboratory provided excellent thermal efficiency. However, these good results contrast with the low flow rate levels registered during the tests. Thus, although this technology seems to be very promising, new experimental tests should be performed before an effective application is possible

  14. 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.

  15. Comparison of optimum tilt angles of solar collectors determined at yearly, seasonal and monthly levels

    International Nuclear Information System (INIS)

    Despotovic, Milan; Nedic, Vladimir

    2015-01-01

    Highlights: • Optimum yearly, biannual, seasonal, monthly, and daily tilt angles were found. • Energy collected per square meter is compared for ten different scenarios. • Four seasonal scenarios and two biannual scenarios were considered. • It is sufficient to adjust tilt angles only twice per year. - Abstract: The amount of energy that is transformed in solar collector depends on its tilt angle with respect to horizontal plane and orientation of the collector. In this article the optimum tilt angle of solar collectors for Belgrade, which is located at the latitude of 44°47′N is determined. The optimum tilt angle was found by searching for the values for which the solar radiation on the collector surface is maximum for a particular day or a specific period. In that manner the yearly, biannual, seasonal, monthly, fortnightly, and daily optimum tilt angles are determined. Annually collected energy per square meter of tilted surface is compared for ten different scenarios. In addition, these optimum tilt angles are used to calculate the amount of energy on the surface of PV panels that could be installed at the roof of the building. The results show that for observed case study placing the panels at yearly, seasonal and monthly optimum tilt angles, would yield increasing yearly amount of collected energy by factor of 5.98%, 13.55%, and 15.42% respectively compared to energy that could be collected by putting the panels at current roofs’ surface angles

  16. COPPER AND COPPER-CONTAINING PESTICIDES: METABOLISM, TOXICITY AND OXIDATIVE STRESS

    Directory of Open Access Journals (Sweden)

    Viktor Husak

    2015-05-01

    Full Text Available The purpose of this paper is to provide a brief review of the current knowledge regarding metabolism and toxicity of copper and copper-based pesticides in living organisms. Copper is an essential trace element in all living organisms (bacteria, fungi, plants, and animals, because it participates in different metabolic processes and maintain functions of organisms. The transport and metabolism of copper in living organisms is currently the subject of many studies. Copper is absorbed, transported, distributed, stored, and excreted in the body via the complex of homeostatic processes, which provide organisms with a needed constant level of this micronutrient and avoid excessive amounts. Many aspects of copper homeostasis were studied at the molecular level. Copper based-pesticides, in particularly fungicides, bacteriocides and herbicides, are widely used in agricultural practice throughout the world. Copper is an integral part of antioxidant enzymes, particularly copper-zinc superoxide dismutase (Cu,Zn-SOD, and plays prominent roles in iron homeostasis. On the other hand, excess of copper in organism has deleterious effect, because it stimulates free radical production in the cell, induces lipid peroxidation, and disturbs the total antioxidant capacity of the body. The mechanisms of copper toxicity are discussed in this review also.

  17. Numerical investigation of collector cooling for a 1 MW ITER gyrotron operated with vertical sweeping

    Energy Technology Data Exchange (ETDEWEB)

    Savoldi, Laura; Bertani, Cristina [Dipartimento Energia, Politecnico di Torino (Italy); Cau, Francesca; Cismondi, Fabio [Fusion for Energy, Barcelona (Spain); Gantenbein, Gerd; Illy, Stefan [KIT, Karlsruhe (Germany); Monni, Grazia [Dipartimento Energia, Politecnico di Torino (Italy); Zanino, Roberto, E-mail: roberto.zanino@polito.it [Dipartimento Energia, Politecnico di Torino (Italy)

    2015-11-15

    The present gyrotron designs for EC plasma heating in nuclear fusion reactors require the safe exhaust of a power comparable to that injected into the plasma, in order to keep the maximum temperature below the acceptable value of 300 °C. In this paper, the commercial computational fluid dynamics (CFD) software STAR-CCM+{sup ®} is used to analyze the thermal performance of the annular copper collector of a 1 MW ITER gyrotron, equipped with a hypervapotron structure made of annular fins with rectangular cavities of aspect ratio (depth/width) = 3, cooled by highly subcooled (90–100 °C) pressurized water flowing at ∼4 m/s. It is assumed that the simple vertical sweeping strategy is used to reduce the very high peak heat flux on the collector (up to 30 MW/m{sup 2} transient, 5 MW/m{sup 2} time average), due to the spent electron beam. The 2D steady-state conjugate heat transfer problem is solved assuming azimuthal symmetry and accounting for 2-phase flow. The single-cavity flow and heat transfer problem is considered first, to optimize the mesh and the selection of the turbulence model. For the operating conditions considered in this paper, the full collector (100+ cavities) solution shows that boiling occurs only in a limited number of cavities close to the peaks of the heat flux, with the vapor remaining trapped in the bottom of the cavities, i.e. no full hypervapotron regime should be achieved in these operating conditions. The steady-state analysis allows the numerical evaluation of the heat transfer coefficients between Cu and water; these are then used as input for the simplified, purely thermal (solid only) analysis of the actual transient problem for the full collector. The results of the simplified model, which allows a huge reduction of the computational effort, are successfully benchmarked against those of a comprehensive thermal–hydraulic simulation. The computed peak Cu temperature is below the acceptable limit under the steady-state (time averaged

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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...

  5. 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.

  6. 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

  7. 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...

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. 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)

  13. 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...

  14. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-12-15

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

  16. Copper atomic-scale transistors.

    Science.gov (United States)

    Xie, Fangqing; Kavalenka, Maryna N; Röger, Moritz; Albrecht, Daniel; Hölscher, Hendrik; Leuthold, Jürgen; Schimmel, Thomas

    2017-01-01

    We investigated copper as a working material for metallic atomic-scale transistors and confirmed that copper atomic-scale transistors can be fabricated and operated electrochemically in a copper electrolyte (CuSO 4 + H 2 SO 4 ) in bi-distilled water under ambient conditions with three microelectrodes (source, drain and gate). The electrochemical switching-on potential of the atomic-scale transistor is below 350 mV, and the switching-off potential is between 0 and -170 mV. The switching-on current is above 1 μA, which is compatible with semiconductor transistor devices. Both sign and amplitude of the voltage applied across the source and drain electrodes ( U bias ) influence the switching rate of the transistor and the copper deposition on the electrodes, and correspondingly shift the electrochemical operation potential. The copper atomic-scale transistors can be switched using a function generator without a computer-controlled feedback switching mechanism. The copper atomic-scale transistors, with only one or two atoms at the narrowest constriction, were realized to switch between 0 and 1 G 0 ( G 0 = 2e 2 /h; with e being the electron charge, and h being Planck's constant) or 2 G 0 by the function generator. The switching rate can reach up to 10 Hz. The copper atomic-scale transistor demonstrates volatile/non-volatile dual functionalities. Such an optimal merging of the logic with memory may open a perspective for processor-in-memory and logic-in-memory architectures, using copper as an alternative working material besides silver for fully metallic atomic-scale transistors.

  17. Electrodialytic remediation of copper mine tailings

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Rojo, A.; Ottpsen, Lisbeth M.

    2005-01-01

    electrodialytic remediation experiments on copper mine tailings. The results show that electric current could remove copper from watery tailing if the potential gradient was higher than 2V/cm during 21 days. With addition of sulphuric acid, the process was enhanced because the pH decreased to around 4...

  18. Design, Simulation and Experimental Investigation of a Solar System Based on PV Panels and PVT Collectors

    Directory of Open Access Journals (Sweden)

    Annamaria Buonomano

    2016-06-01

    Full Text Available This paper presents numerical and experimental analyses aimed at evaluating the technical and economic feasibility of photovoltaic/thermal (PVT collectors. An experimental setup was purposely designed and constructed in order to compare the electrical performance of a PVT solar field with the one achieved by an identical solar field consisting of conventional photovoltaic (PV panels. The experimental analysis also aims at evaluating the potential advantages of PVT vs. PV in terms of enhancement of electrical efficiency and thermal energy production. The installed experimental set-up includes four flat polycrystalline silicon PV panels and four flat unglazed polycrystalline silicon PVT collectors. The total electrical power and area of the solar field are 2 kWe and 13 m2, respectively. The experimental set-up is currently installed at the company AV Project Ltd., located in Avellino (Italy. This study also analyzes the system from a numerical point of view, including a thermo-economic dynamic simulation model for the design and the assessment of energy performance and economic profitability of the solar systems consisting of glazed PVT and PV collectors. The experimental setup was modelled and partly simulated in TRNSYS environment. The simulation model was useful to analyze efficiencies and temperatures reached by such solar technologies, by taking into account the reference technology of PVTs (consisting of glazed collectors as well as to compare the numerical data obtained by dynamic simulations with the gathered experimental results for the PV technology. The numerical analysis shows that the PVT global efficiency is about 26%. Conversely, from the experimental point of view, the average thermal efficiency of PVT collectors is around 13% and the electrical efficiencies of both technologies are almost coincident and equal to 15%.

  19. Evaluating performance from spiral polyethylene tubes as solar collectors for heating swimming pools

    Energy Technology Data Exchange (ETDEWEB)

    Stefanelli, Anderson Thiago Pontes; Marchi Neto, Ismael de; Scalon, Vicente Luiz; Padilha, Alcides [UNESP, Universidade Estadual Paulista Julio de Mesquita Filho, Bauru, SP (Brazil). Dept. de Engenharia Mecanica], e-mails: scalon@feb.unesp.br, padilha@feb.unesp.br

    2010-07-01

    The solar energy is very common in the daily of citizens from different regions in world. Environmental questions and the consequent Development of renewable energy techniques were a decisive factor for expanding this market. Currently, the solar energy is present in many different devices: as direct conversion through photovoltaic panels as in solar domestic for hot water systems(SDHWS). Another common use is in the heating system for swimming pools, that could be utilized for therapeutic or comfort reasons. The main aspect that increments this use is the economy for operation of these systems. On the other hand, these systems need a high initial investment. Reducing this cost without reduction in collector efficiency using new materials and / or alternative projects is important target for new researches. Thus, this paper aims to analyze the efficiency of one of these alternative models for heating swimming pools. The conceptual device evaluated is a low cost model. It could be made from polyethylene tubes forming spiral heat exchangers. Analysis of the system is based on a dynamic model using differential equations system including solar collector and swimming pool. Experimental radiation and other environmental conditions in the region of Bauru-SP are used for analyse the dynamic behavior of the system. The simulations are based on analysis of three main parameters: number of collectors, the pump drive time and wall thickness of the collector of polyethylene. Based on these numerical tests one can conclude that this new model of solar collector for swimming pool has a better cost benefit ratio when superficial area is equal to 80% of pool area, pump operation is alternating with four minutes turned on and 28 turned off and the polyethylene wall thickness is 1.5 mm (author)

  20. Performance of Polycrystalline Photovoltaic and Thermal Collector (PVT on Serpentine-Parallel Absorbers Design

    Directory of Open Access Journals (Sweden)

    Mustofa Mustofa

    2017-03-01

    Full Text Available This paper presents the performance of an unglazed polycrystalline photovoltaic-thermal PVT on 0.045 kg/s mass flow rate. PVT combine photovoltaic modules and solar thermal collectors, forming a single device that receive solar radiation and produces heat and electricity simultaneously. The collector figures out serpentine-parallel tubes that can prolong fluid heat conductivity from morning till afternoon. During testing, cell PV, inlet and outlet fluid temperaturs were recorded by thermocouple digital LM35 Arduino Mega 2560. Panel voltage and electric current were also noted in which they were connected to computer and presented each second data recorded. But, in this performance only shows in the certain significant time data. This because the electric current was only noted by multimeter device not the digital one. Based on these testing data, average cell efficieny was about 19%, while thermal efficiency of above 50% and correspondeng cell efficiency of 11%, respectively

  1. Performance of Polycrystalline Photovoltaic and Thermal Collector (PVT on Serpentine-Parallel Absor

    Directory of Open Access Journals (Sweden)

    Mustofa

    2015-10-01

    Full Text Available This paper presents the performance of an unglazed polycrystalline photovoltaic-thermal PVT on 0.045 kg/s mass flow rate. PVT combine photovoltaic modules and solar thermal collectors, forming a single device that receive solar radiation and produces heat and electricity simultaneously. The collector figures out serpentine-parallel tubes that can prolong fluid heat conductivity from morning till afternoon. During testing, cell PV, inlet and outlet fluid temperatures were recorded by thermocouple digital LM35 Arduino Mega 2560. Panel voltage and electric current were also noted in which they were connected to computer and presented each second data recorded. But, in this performance only shows in the certain significant time data. This because the electric current was only noted by multimeter device not the digital one. Based on these testing data, average cell efficiency was about 19%, while thermal efficiency of above 50% and correspondent cell efficiency of 11%, respectively.

  2. Ultrathin nickel hydroxide on carbon coated 3D-porous copper structures for high performance supercapacitors.

    Science.gov (United States)

    Kang, Kyeong-Nam; Kim, Ik-Hee; Ramadoss, Ananthakumar; Kim, Sun-I; Yoon, Jong-Chul; Jang, Ji-Hyun

    2018-01-03

    An ultrathin nickel hydroxide layer electrodeposited on a carbon-coated three-dimensional porous copper structure (3D-C/Cu) is suggested as an additive and binder-free conductive electrode with short electron path distances, large electrochemical active sites, and improved structural stability, for high performance supercapacitors. The 3D-porous copper structure (3D-Cu) provides high electrical conductivity and facilitates electron transport between the Ni(OH) 2 active materials and the current collector of the Ni-plate. A carbon coating was applied to the 3D-Cu to prevent the oxidation of Cu, without degrading the electron transport behavior of the 3D-Cu. The 3D-Ni(OH) 2 /C/Cu exhibited a high specific capacitance of 1860 F g -1 at 1 A g -1 , and good cycling performance, with an 86.5% capacitance retention after 10 000 cycles. When tested in a two-electrode system, an asymmetric supercapacitor exhibited an energy density of 147.9 W h kg -1 and a power density of 37.0 kW kg -1 . These results open a new area of ultrahigh-performance supercapacitors, supported by 3D-Cu electrodes.

  3. 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.

  4. 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.

  5. 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.

  6. Divalent Copper as a Major Triggering Agent in Alzheimer's Disease.

    Science.gov (United States)

    Brewer, George J

    2015-01-01

    Alzheimer's disease (AD) is at epidemic proportions in developed countries, with a steady increase in the early 1900 s, and then exploding over the last 50 years. This epidemiology points to something causative in the environment of developed countries. This paper will review the considerable evidence that that something could be inorganic copper ingestion. The epidemic parallels closely the spread of copper plumbing, with copper leached from the plumbing into drinking water being a main causal feature, aided by the increasingly common use of supplement pills containing copper. Inorganic copper is divalent copper, or copper-2, while we now know that organic copper, or copper in foods, is primarily monovalent copper, or copper-1. The intestinal transport system, Ctr1, absorbs copper-1 and the copper moves to the liver, where it is put into safe channels. Copper-2 is not absorbed by Ctr1, and some of it bypasses the liver and goes directly into the blood, where it appears to be exquisitely toxic to brain cognition. Thus, while aggregation of amyloid-β has been postulated to be the cause of AD under current dogma, the great increase in prevalence over the last century appears to be due to ingestion of copper-2, which may be causing the aggregation, and/or increasing the oxidant toxicity of the aggregates. An alternative hypothesis proposes that oxidant stress is the primary injuring agent, and under this hypothesis, copper-2 accumulation in the brain may be a causal factor of the oxidant injury. Thus, irrespective of which hypothesis is correct, AD can be classified, at least in part, as a copper-2 toxicity disease. It is relatively easy to avoid copper-2 ingestion, as discussed in this review. If most people begin avoiding copper-2 ingestion, perhaps the epidemic of this serious disease can be aborted.

  7. Antwerp Copper Plates

    DEFF Research Database (Denmark)

    Wadum, Jørgen

    1999-01-01

    In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes.......In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes....

  8. Copper and Copper Proteins in Parkinson's Disease

    Science.gov (United States)

    Rivera-Mancia, Susana; Diaz-Ruiz, Araceli; Tristan-Lopez, Luis; Rios, Camilo

    2014-01-01

    Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology. PMID:24672633

  9. High-Efficiency Fog Collector: Water Unidirectional Transport on Heterogeneous Rough Conical Wires.

    Science.gov (United States)

    Xu, Ting; Lin, Yucai; Zhang, Miaoxin; Shi, Weiwei; Zheng, Yongmei

    2016-12-27

    An artificial periodic roughness-gradient conical copper wire (PCCW) can be fabricated by inspiration from cactus spines and wet spider silks. PCCW can harvest fog on periodic points of the conical surface from air and transports the drops for a long distance without external force, which is attributed to dynamic as-released energy generated from drop deformation in drop coalescence, in addition to both gradients of geometric curve (inducing Laplace pressure) and periodic roughness (inducing surface energy difference). It is found that the ability of fog collection can be related to various tilt-angle wires, thus a fog collector with an array system of PCCWs is further designed to achieve a continuous process of efficient water collection. As a result, the effect of water collection on PCCWs is better than previous results. These findings are significant to develop and design materials with water collection and water transport for promising application in fogwater systems to ease the water crisis.

  10. Separation of copper-64 from copper phthalocyanine

    International Nuclear Information System (INIS)

    Battaglin, R.I.M.

    1979-01-01

    The separation of copper-64 from irradiated copper phthalocyanine by Szilard-Chalmers effect is studied. Two methods of separation are used: one of them is based on the dissolution of the irradiated dry compound in concentrated sulfuric acid following its precipitation in water. In the other one the compound is irradiated with water in paste form following treatment with water and hydrochloric acid. The influence of the crystal form of the copper phthalocyanine on the separation yield of copper-64 is shown. Preliminary tests using the ionic exchange technique for purification and changing of copper-64 sulfate to chloride form are carried out. The specific activity using the spectrophotometric technique, after the determination of the copper concentration in solution of copper-64, is calculated. (Author) [pt

  11. Copper as a target for prostate cancer therapeutics: copper-ionophore pharmacology and altering systemic copper distribution

    Science.gov (United States)

    Denoyer, Delphine; Pearson, Helen B.; Clatworthy, Sharnel A.S.; Smith, Zoe M.; Francis, Paul S.; Llanos, Roxana M.; Volitakis, Irene; Phillips, Wayne A.; Meggyesy, Peter M.; Masaldan, Shashank; Cater, Michael A.

    2016-01-01

    Copper-ionophores that elevate intracellular bioavailable copper display significant therapeutic utility against prostate cancer cells in vitro and in TRAMP (Transgenic Adenocarcinoma of Mouse Prostate) mice. However, the pharmacological basis for their anticancer activity remains unclear, despite impending clinical trails. Herein we show that intracellular copper levels in prostate cancer, evaluated in vitro and across disease progression in TRAMP mice, were not correlative with copper-ionophore activity and mirrored the normal levels observed in patient prostatectomy tissues (Gleason Score 7 & 9). TRAMP adenocarcinoma cells harbored markedly elevated oxidative stress and diminished glutathione (GSH)-mediated antioxidant capacity, which together conferred selective sensitivity to prooxidant ionophoric copper. Copper-ionophore treatments [CuII(gtsm), disulfiram & clioquinol] generated toxic levels of reactive oxygen species (ROS) in TRAMP adenocarcinoma cells, but not in normal mouse prostate epithelial cells (PrECs). Our results provide a basis for the pharmacological activity of copper-ionophores and suggest they are amendable for treatment of patients with prostate cancer. Additionally, recent in vitro and mouse xenograft studies have suggested an increased copper requirement by prostate cancer cells. We demonstrated that prostate adenocarcinoma development in TRAMP mice requires a functional supply of copper and is significantly impeded by altered systemic copper distribution. The presence of a mutant copper-transporting Atp7b protein (tx mutation: A4066G/Met1356Val) in TRAMP mice changed copper-integration into serum and caused a remarkable reduction in prostate cancer burden (64% reduction) and disease severity (grade), abrogating adenocarcinoma development. Implications for current clinical trials are discussed. PMID:27175597

  12. 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.

  13. 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 

  14. The performance of solar collector CPC (compound parabolic concentrator) type with three pipes covered by glass tubes

    Science.gov (United States)

    Gaos, Yogi Sirodz; Yulianto, Muhamad; Juarsa, Mulya; Nurrohman, Marzuki, Edi; Yuliaji, Dwi; Budiono, Kabul

    2017-03-01

    Indonesia is a tropical country that has potential energy of solar radiation worth of 4.5 until 4.8 kWh/m2. However, this potential has not been utilized regularly. This paper will discuss the performance of solar collector compound parabolic concentrator (CPC) type with water as the working fluid. This CPC solar collector utilized three pipes covered by glass tubes. This paper has contribution to provide the temperature achievement between three pipes covered by glass tubes with and without glass cover of solar collector CPC type. The research conducted by varying the water flow rate of 1 l/m up to 6 l/m with three pipes arranged in series and parallel. From the results, the used of solar collector CPC type in the current study shows that the decrease of solar radiation, which was caused by climate change, did not influence the heat absorbance by water in the pipe. Therefore, the design of the solar collector in this research has potential to be used in future when solar radiation are used as the energy source.

  15. Axial motion of collector plasma in a relativistic backward wave oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Renzhen; Chen, Changhua; Deng, Yuqun; Cao, Yibing; Sun, Jun; Li, Jiawei [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi' an 710024 (China)

    2016-06-15

    In this paper, it is proposed that plasma formed at the collector may drift back to the cathode and cause pulse shortening of the relativistic backward wave oscillator. Theoretical analysis shows that the axial drift velocity of plasma ions can be up to 5 mm/ns due to the presence of space charge potential provided by an intense relativistic electron beam. Particle-in-cell simulations indicate that the plasma electrons are initially trapped around the collector surface. With the accumulation of the plasma ions, a large electrostatic field forms and drives the plasma electrons to overcome the space charge potential and enter the beam-wave interaction region along the magnetic field lines. As a result, the beam current modulation is disturbed and the output microwave power falls rapidly. The plasma ions move in the beam-wave interaction region with an average axial velocity of 5–8 mm/ns. After the plasma ions reach the diode region, the emitted current at the cathode rises due to the charge neutralizations by the ions. The impedance collapse leads to further decrease of the microwave power. In experiments, when the diode voltage and beam current were 850 kV and 9.2 kA, and the collector radius was 2.15 cm, the output microwave power was 2.4 GW with a pulse width of less than 20 ns. The ion drift velocity was estimated to be about 5 mm/ns. After an improved collector with 3.35 cm radius was adopted, the pulse width was prolonged to more than 30 ns.

  16. 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.

  17. 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...

  18. 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...

  19. 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

  20. Tunable synthesis of copper nanotubes

    International Nuclear Information System (INIS)

    Kaniukov, E; Yakimchuk, D; Kozlovsky, A; Shlimas, D; Zdorovets, M; Kadyrzhanov, K

    2016-01-01

    Simple method of tunable synthesis of copper nanotubes based on template synthesis was developed. A comprehensive study of the structural, morphological and electrical characteristics of the obtained nanostructures was carried out. Characterization of structural features was made by methods of scanning electron microscopy, energy dispersive spectroscopy and X-ray diffractometry analysis. Evaluation of wall thickness is made by methods of gas permeability. Electrical conductivity of nanotubes was define in the study of their current-voltage characteristics. The possibility to control of copper nanotubes physical properties by variation of the deposition parameters was shown. (paper)

  1. Numerical design of an EBIS collector to optimize electron collection and ion extraction

    International Nuclear Information System (INIS)

    Dietrich, J.

    1990-01-01

    For the Frankfurt EBIS, a new collector was designed using the relativistic electron optics program EGUN and the magnetic field program INTMAG. To model the fringing field of the main solenoid, a bucking coil and a cylindrical shim is provided. The current of the bucking coil and the position and shape of the shim are optimized with INTMAG for minimum fringing field to allow expansion of the electron beam by its space charge. The magnetic field data output from INTMAG is directly used as input for EGUN to calculate the ectron and ion trajectories. The initial conditions for the trajectories were computed from the paraxial ray equation. Different operation modes of the collector are investigated including the behaviour of secondary electrons. (orig.)

  2. Numerical design of an EBIS collector to optimize electron collection and ion extraction

    Science.gov (United States)

    Dietrich, Jürgen

    1990-12-01

    For the Frankfurt EBIS (R. Becker et al., Nucl. Instr. and Meth. B24/25 (1987) 838, ref. [1]), a new collector was designed using the relativistic electron optics program EGUN (W.B. Herrmannsfeldt, SLAC-331 (1988), ref. [2]) and the magnetic field program INTMAG (R. Becker, Nucl. Instr. and Meth. B42 (1989) 303, ref. [3]). To model the fringing field of the main solenoid, a bucking coil and a cylindrical shim is provided. The current of the bucking coil and the position and shape of the shim are optimized with INTMAG for minimum fringing field to allow expansion of the electron beam by its space charge. The magnetic field data output from INTMAG is directly used as input for EGUN to calculate the electron and ion trajectories. The initial conditions for the trajectories were computed from the paraxial ray equation. Different operation modes of the collector are investigated including the behaviour of secondary electrons.

  3. Numerical design of an EBIS collector to optimize electron collection and ion extraction

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, J. (Frankfurt Univ. (Germany, F.R.). Inst. fuer Angewandte Physik)

    1990-12-01

    For the Frankfurt EBIS, a new collector was designed using the relativistic electron optics program EGUN and the magnetic field program INTMAG. To model the fringing field of the main solenoid, a bucking coil and a cylindrical shim is provided. The current of the bucking coil and the position and shape of the shim are optimized with INTMAG for minimum fringing field to allow expansion of the electron beam by its space charge. The magnetic field data output from INTMAG is directly used as input for EGUN to calculate the ectron and ion trajectories. The initial conditions for the trajectories were computed from the paraxial ray equation. Different operation modes of the collector are investigated including the behaviour of secondary electrons. (orig.).

  4. Electron collector and ion species experiments on the LION extractor ion diode

    International Nuclear Information System (INIS)

    Rondeau, G.; Greenly, J.B.; Hammer, D.A.; Horioka, K.; Meyerhofer, D.D.

    1987-01-01

    Studies of the effects of an electron collector on the electron flow in an ion diode and on diode impedance history are being done with an extractor geometry ion diode (B/sub r/ magnetic insulation field) on the LION accelerator (1.5 MV, 4Ω, 40 ns). The collector is a flux-penetrable metal protrusion on the inner radius of the anode that collects electrons. This device increases the diode operating impedance particularly during the later part of the pulse when the diode impedance collapses without the collector. In the present set of experiments, several thin wires are inserted into the anode and allowed to protrude a few millimeters into the A-K gap. These wires are damaged by the electron flow during the pulse and by measuring the length of the remaining wire, the distance of the electron layer from the anode can be inferred. The ion current density is also measured in three radial locations across the diode, giving a measure, through the Child-Langmuir law, of the effective gap spacing between the anode and the electron sheath. A simple model is proposed to account for the scaling of ion current density with the diode voltage observed in the experiment

  5. Operation of resonant-tunneling diodes with strong back injection from the collector at frequencies up to 1.46 THz

    International Nuclear Information System (INIS)

    Feiginov, Michael; Kanaya, Hidetoshi; Suzuki, Safumi; Asada, Masahiro

    2014-01-01

    In search for possibilities to increase the operating frequencies of resonant-tunneling diodes (RTDs), we are studying RTDs working in an unusual regime. The collector side of our diodes is so heavily doped that the collector depletion region is fully eliminated in our RTDs and the ground quantum-well subband stays immersed under (or stays close to) the collector quasi-Fermi level. The electron injection from the collector into the RTD quantum well is very strong in our diodes and stays comparable to that from the emitter in the whole range of RTD operating biases. Our RTDs exhibit well pronounced negative-differential-conductance region and peak-to-valley current ratio around 1.8. We demonstrate operation of our diodes in RTD oscillators up to 1.46 THz. We also observe a fine structure in the emission spectra of our RTD oscillators, when they are working in the regime close to the onset of oscillations.

  6. On the mechanism of action of combination of thionocarbamates with xanthate during flotation of copper-molybdenum pyrite contained ores

    International Nuclear Information System (INIS)

    Nedosekina, T.V.; Glembotskij, A.V.; Bekhtle, G.A.; Novgorodova, Eh.Z.

    1985-01-01

    Investigation results of action mechanism of thionocarbamates combination with xanthate are described. It is established that these collectors are capable of co-adsorbing on pyrite surface, that is the reason for sharp increase of the floatability and disturbs the selectivity of copper-molybdenum pyrite-containing ore flotation

  7. 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%.

  8. 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)

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. [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.

  14. 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. 

  15. 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

  16. 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.

  17. 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.

  18. 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...

  19. 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)

  20. 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...

  1. 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.

  2. 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...

  3. 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.

  4. 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...

  5. 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...

  6. 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.

  7. Recovery of Copper from Slow Cooled Ausmelt Furnace Slag by Floatation

    Science.gov (United States)

    Xue, Ping; Li, Guangqiang; Qin, Qingwei

    Ausmelt furnace slag contains about 0.9% Cu (mass %). With increasing the amount of Ausmelt furnace slag, the recovery of copper from it will produce an enormous economic yield. The recovery of copper by floatation from slow cooled Ausmelt furnace slag was studied in this paper. The phases and composition of the slow cooled slag were analyzed. The factors which affected the copper recovery efficiency such as grinding fineness, pH value of flotation medium, different collectors and floating process were investigated. It was shown that the size distribution of the primary grinding and secondary grinding of middling were 75% for particles less than 0.074mm and 82% for particles less than 0.043mm respectively. The closed-circuit experimental results with butyl xanthate as collector in laboratory showed that the copper grade reached 16.11% and the recovery rate of copper reached 69.90% and the copper grade of tailings was only 0.2%.

  8. Grid collector an event catalog with automated file management

    CERN Document Server

    Ke Sheng Wu; Sim, A; Jun Min Gu; Shoshani, A

    2004-01-01

    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 ev...

  9. 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.

  10. Aquatic Life Criteria - Copper

    Science.gov (United States)

    Documents pertain to Aquatic Life Ambient Water Quality criteria for Copper (2007 Freshwater, 2016 Estuarine/marine). These documents contain the safe levels of Copper in water that should protect to the majority of species.

  11. 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.

  12. Copper Bioleaching in Chile

    OpenAIRE

    Juan Carlos Gentina; Fernando Acevedo

    2016-01-01

    Chile has a great tradition of producing and exporting copper. Over the last several decades, it has become the first producer on an international level. Its copper reserves are also the most important on the planet. However, after years of mineral exploitation, the ease of extracting copper oxides and ore copper content has diminished. To keep the production level high, the introduction of new technologies has become necessary. One that has been successful is bioleaching. Chile had the first...

  13. A compact E × B filter: A multi-collector cycloidal focusing mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Blase, Ryan C., E-mail: rblase@swri.edu; Miller, Greg; Brockwell, Tim; Waite, J. Hunter [Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238 (United States); Westlake, Joseph [The Johns Hopkins University Applied Physics Laboratory LLC, 11100 Johns Hopkins Road, Laurel, Maryland 20723 (United States); Ostrom, Nathaniel; Ostrom, Peggy H. [Department of Integrative Biology, Michigan State University, 288 Farm Lane RM 203, East Lansing, Michigan 48824 (United States)

    2015-10-15

    A compact E × B mass spectrometer is presented. The mass spectrometer presented is termed a “perfect focus” mass spectrometer as the resolution of the device is independent of both the initial direction and energy of the ions (spatial and energy independent). The mass spectrometer is small in size (∼10.7 in.{sup 3}) and weight (∼2 kg), making it an attractive candidate for portability when using small, permanent magnets. A multi-collector Faraday cup design allows for the detection of multiple ion beams in discrete collectors simultaneously; providing the opportunity for isotope ratio monitoring. The mass resolution of the device is around 400 through narrow collector slits and the sensitivity of the device follows expected theoretical calculations of the ion current produced in the electron impact ion source. Example mass spectra obtained from the cycloidal focusing mass spectrometer are presented as well as information on mass discrimination based on instrumental parameters and isotope ratio monitoring of certain ion signals in separate Faraday cups.

  14. 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.

  15. 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

  16. Optimization of sedimentation of tungsten on copper substrate for production of {sup 186g}Re via {sup 186}W(p,n) nuclear reaction: Feasibility of using high current, long irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kakavand, T., E-mail: Tayeb@znu.ac.ir [Department of Physics, Faculty of Science, Imam Khomeini International University, Qazvin (Iran, Islamic Republic of); Mirzaii, M.; Khaleghi, M. [Agricultural, Medical and Industrial Research School, Nuclear Science and Technology Research Institute, AEOI, Karaj (Iran, Islamic Republic of); Eslami, M. [Department of Physics, Faculty of Science, University of Zanjan, Zanjan (Iran, Islamic Republic of)

    2016-01-01

    Highlights: • Optimization of tungsten sedimentation for bulk production of {sup 186}Re. • Influence of targetry parameters on stress-bearing of the target during proton irradiation. • Activity measurement for {sup 186}Re produced via {sup nat}W(p,xn) reaction. - Abstract: Tungsten is recognized as one of the important metals used in cyclotron targets for production of several vital radioisotopes. Adequate adhesion of the prepared targets to its substrate is a significant parameter that makes them optimized for high current beam collisions. The target morphology should be paid special attention as another important parameter. In this work, a rather thick layer of tungsten is deposited on a copper substrate by sedimentation technique to produce {sup 186g}Re radionuclide via {sup 186}W(p,n) reaction. Consecutive sedimentation experiments are carried out to determine the best suspension solution. The prepared targets are evaluated in morphology by scanning electron microscope. A mixture of 1 g tungsten powder, 250 mg ethyl cellulose and 5 mL acetone is concluded for desirable target adhesion. Irradiation of the targets by 20 μA proton current (15 MeV energy) for 5 h shows that they can withstand the proton beam.

  17. 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.

  18. Thermal performance assessment of a large aperture concentrating collector in an industrial application in Chile

    Science.gov (United States)

    Murray, Clare; Pino, Alan; Cardemil, José Miguel; Escobar, Rodrigo

    2017-06-01

    The application of solar thermal energy to meet the heat demands of the food and beverage processing industry in Chile has huge potential. This paper presents an assessment of the first large aperture trough collector installed in Latin America. The collector preheats water for a boiler in a juice-concentrating factory, 100 km north of Santiago. An analysis of the system for a day in November indicates the system was not able to utilize the heat generated, resulting in rapid de- and refocusing of the collector and problems with sensor calibration. An analysis of a day in March indicates the tracking algorithm has not correctly aligned the collector with the sun's position. An investigation into the design document reveals that the meteorological data underestimates the actual irradiation values by 40%, resulting in an oversized system given the actual conditions. To increase the energy gain in the system it is proposed to increase the working pressure from the current value of 1.5bar to up to 5bar, which could increase the system utilization from 41% to 65% and reduce the dumped energy to near zero. The simulation results with actual weather data and a fixed inlet temperature indicate the annual solar fraction could increase from the design value of 8.1% to 31.8% with a working pressure of 5 bar. The plant presents multiple opportunities for improvement not only to the performance of the plant but also in the design and installation of solar thermal systems in Chile in the future.

  19. Demystifying Controlling Copper Corrosion

    Science.gov (United States)

    The LCR systematically misses the highest health and corrosion risk sites for copper. Additionally, there are growing concerns for WWTP copper in sludges and discharge levels. There are many corrosion control differences between copper and lead. This talk explains the sometimes c...

  20. 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.

  1. 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

  2. Watergy. A moist air solar collector system with an integrated brine circuit for te heating of buildings; Watergy. Ein Feuchtluft-Solarkollektorsystem mit integriertem Solekreislauf zur Gebaeudeheizung

    Energy Technology Data Exchange (ETDEWEB)

    Buchholz, Martin; Buchholz, Reiner; Geyer, Philipp; Schmidt, Marco [Technische Univ. Berlin (Germany). Fachgebiet Gebaeudetechnik und Entwerfen

    2010-07-01

    Due to the Renewable Energy Law 2009, the proportion of renewable energies in the overall energy consumption of the European Union increased to 20 %. Currently, the proportion of the total heat energy consumption in Germany amounts nearly 40 %. Previous concepts for the storage of heat in the summer for use in winter are not convincing. The improvement of the efficiency of solar collectors and an increase in the collector surface result in increased investment costs and costs for heat supply. Thus, solar collector systems should be optimized for the operation of heaters. This is done for example by reducing the mean collector temperature using a combination of solar collectors with a heat pump. However, heat pumps are operated by means of electrical energy. Electrical energy can not be saved in the summer in order to be used in the winter. Under this aspect, the authors of the contribution under consideration report on the Watergy concept - a moist air solar collector system with an integrated brine circuit for heating of buildings.

  3. 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)

  4. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  5. effect of blending various collectors at bulk flotation of copper and ...

    African Journals Online (AJOL)

    It was established that the use of the other reagents such as PAX, SIPX, DANFLOAT123, DANAFLOAT 245 would be costly as compared to SEX. Cost of DANFLOAT 245 and 123 are $1.28 and $1.33 per kg respectively as compared to SEX at $1.23 per kg whereas SIPX and PAX are also slightly higher than SEX making ...

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. Earth's copper resources estimated from tectonic diffusion of porphyry copper deposits

    Science.gov (United States)

    Kesler, Stephen E.; Wilkinson, Bruce H.

    2008-03-01

    Improved estimates of global mineral endowments are relevantto issues ranging from strategic planning to global geochemicalcycling. We have used a time-space model for the tectonic migrationof porphyry copper deposits vertically through the crust tocalculate Earth's endowment of copper in mineral deposits. Themodel relies only on knowledge of numbers and ages of porphyrycopper deposits, Earth's most widespread and important sourceof copper, in order to estimate numbers of eroded and preserveddeposits in the crust. Model results indicate that 125,895 porphyrycopper deposits were formed during Phanerozoic time, that only47,789 of these remain at various crustal depths, and that thesecontain 1.7 x 1011 tonnes (t) of copper. Assuming that othertypes of copper deposits behave similarly in the crust and haveabundances proportional to their current global production yieldsan estimate of 3 x 1011 t for total global copper resourcesat all levels in Earth's crust. Thus, 0.25% of the copper inthe crust has been concentrated into deposits through Phanerozoictime, and about two-thirds of this has been recycled by upliftand erosion. The amount of copper in deposits above 3.3 km,a likely limit of future mining, could supply current worldmine production for 5500 yr, thus quantifying the highly unusualand nonrenewable nature of mineral deposits.

  15. Biological role of copper and copper-containing proteins in human and animal organism

    OpenAIRE

    ANTONYAK H.L.; VAZHNENKO A.V.; PANAS N.E.

    2011-01-01

    Current scientific data related to copper metabolism and functional activity of Cu-containing proteins in human and animal cells are reviewed in the article. Important functional role of this essential element in human and animal organism is analyzed.

  16. N Deposition Effects on Hermes Copper Butterfly (Lycaena hermes) Habitat in Southern California

    Science.gov (United States)

    Malter, L. I.; Vourlitis, G. L.

    2017-12-01

    Atmospheric nitrogen (N) deposition has become a global concern over the past few decades as population sizes have increased. San Diego County, CA, USA, with a high population density, Mediterranean-type climate, and high biodiversity, is an ideal site for an extensive N deposition study. Chronic anthropogenic N deposition is one of the main contributing factors to affect plant species diversity (Vourlitis and Pasquini 2009) and invasive species encroachment (Minnich and Dezzani 1998). It is also the location of the rare endemic Hermes copper butterfly (Lycaena hermes), which has received minimal research and remains a mystery to many ecologists. We hypothesized that N deposition will impact Hermes abundance; however, there is limited research on the effects of N deposition on butterfly habitat. Thus, this study aims to determine the effect of increased N on the alterations to plant-insect interactions. These effects are being measured at five sites throughout San Diego County in current or historical Hermes copper habitat. N deposition collectors have been placed under the canopy of spiny redberry shrubs (Rhamnus crocea) to accumulate N throughfall at each site. Soil and redberry stem fragments are being used to analyze total N and Carbon (C), water potential, and shrub growth throughout the course of this study. Despite the preliminary nature of our results, we show a number of trends between data groups, such as large differences in soil and tissue N and C between the study sites, suggesting differences in atmospheric N inputs. These variations in soil N availability lead to variations in leaf tissue chemistry, which can ultimately impact the performance of the Hermes copper larvae. Our current data demonstrate some clear trends, but whether these trends remain consistent and interpretable remains to be seen. We anticipate this research will increase our understanding of spatial variation patterns of N deposition in southern California and how that N input might

  17. Multidimensional Analysis of Copper Ore Flotation in Terms of Applied Hydrophobizing Agents

    Science.gov (United States)

    Pięta, Paulina; Niedoba, Tomasz; Surowiak, Agnieszka

    2018-03-01

    Flotation is a method of enrichment used to distribute particles, which differ in their surface properties. Hydrophobic solids intrinsically create contact at the solid-liquid-gas interface. However, not all minerals, including copper minerals, can be characterized by this crucial ability. In that case it is necessary to use the collector reagents which guarantees a high efficiency of the enrichment process. The main aim of the paper was to examine the impact of selected collector types and dosages on the results of Polish sandstone copper ore flotation and to find optimal parameter values for products that meet quality and quantity requirements. The laboratory tests were carried out with an application of two types of collectors (Hostaflot, sodium ethyl xanthate aqueous solution) in dosages 100 and 150 g/Mg. Data analysis was based on the use of the taxonomy methods in order to select optimal conditions of collector dosage and type. Based on the indexes, it was found that the best enrichment effects were obtained with a sodium ethyl xanthate aqueous solution 150 g/Mg.

  18. Multidimensional Analysis of Copper Ore Flotation in Terms of Applied Hydrophobizing Agents

    Directory of Open Access Journals (Sweden)

    Pięta Paulina

    2018-01-01

    Full Text Available Flotation is a method of enrichment used to distribute particles, which differ in their surface properties. Hydrophobic solids intrinsically create contact at the solid-liquid-gas interface. However, not all minerals, including copper minerals, can be characterized by this crucial ability. In that case it is necessary to use the collector reagents which guarantees a high efficiency of the enrichment process. The main aim of the paper was to examine the impact of selected collector types and dosages on the results of Polish sandstone copper ore flotation and to find optimal parameter values for products that meet quality and quantity requirements. The laboratory tests were carried out with an application of two types of collectors (Hostaflot, sodium ethyl xanthate aqueous solution in dosages 100 and 150 g/Mg. Data analysis was based on the use of the taxonomy methods in order to select optimal conditions of collector dosage and type. Based on the indexes, it was found that the best enrichment effects were obtained with a sodium ethyl xanthate aqueous solution 150 g/Mg.

  19. 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...

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. 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....

  7. 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.)

  8. 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.

  9. 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...

  10. 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)

  11. Colloidal and electrochemical aspects of copper-CMP

    Science.gov (United States)

    Sun, Yuxia

    Copper based interconnects with low dielectric constant layers are currently used to increase interconnect densities and reduce interconnect time delays in integrated circuits. The technology used to develop copper interconnects involves Chemical Mechanical Planarization (CMP) of copper films deposited on low-k layers (silica or silica based films), which is carried out using slurries containing abrasive particles. One issue using such a structure is copper contamination over dielectric layers (SiO2 film), if not reduced, this contamination will cause current leakage. In this study, the conditions conducive to copper contamination onto SiO2 films during Cu-CMP process were studied, and a post-CMP cleaning technique was discussed based on experimental results. It was found that the adsorption of copper onto a silica surface is kinetically fast (electrocoagulation was investigated to remove both copper and abrasive slurry particles simultaneously. For effluent containing ˜40 ppm dissolved copper, it was found that ˜90% dissolved copper was removed from the waste streams through electroplating and in-situ chemical precipitation. The amount of copper removed through plating is impacted by membrane surface charge, type/amount of complexing agents, and solid content in the slurry suspension. The slurry particles can be removed ˜90% within 2 hours of EC through multiple mechanisms.

  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. NID Copper Sample Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Zhu, Zihua

    2011-09-12

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76Ge. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology, possibly one under development at Nonlinear Ion Dynamics (NID), will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL in January 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are reported here. A second sample of isotopically separated copper was provided by NID to PNNL in August 2011 for isotopic analysis as a test of the NID technology. The results of that analysis are also reported here.

  19. Prediction of the long term accumulation and leaching of copper in Dutch agricultural soils: a risk assessment study

    NARCIS (Netherlands)

    Groenenberg, J.E.; Römkens, P.F.A.M.; Vries, de W.

    2006-01-01

    This report describes a model study to assess whether current copper inputs on agricultural land lead to accumulation of copper and in time to an exceedance of a Predicted No Effect Concentration. A copper mass balance model was applied to the whole Netherlands. Future copper concentrations after

  20. Energy performance of water hybrid PV/T collectors applied to combisystems of Direct Solar Floor type

    Energy Technology Data Exchange (ETDEWEB)

    Fraisse, G.; Johannes, K. [Laboratoire Optimisation de la Conception et Ingenierie de l' Environnement, Ecole Superieure d' Ingenieurs de Chambery, Campus Scientifique Savoie Technolac, 73376 Le Bourget du Lac Cedex (France); Menezo, C. [Centre de Thermique de Lyon, Domaine Scientifique de La Doua, Bat. Freyssinet, 20, Avenue A. Einstein, 69621 Villeurbanne Cedex (France)

    2007-11-15

    The integration of photovoltaic (PV) modules in buildings allows one to consider a multifunctional frame and then to reduce the cost by substitution of components. In order to limit the rise of the cell operating temperature, a photovoltaics/thermal (PV/T) collector combines a solar water heating collector and PV cells. The recovered heat energy can be used for heating systems and domestic hot water. A combination with a Direct Solar Floor is studied. Its low operating temperature level is appropriate for the operating conditions of the mono- or poly-crystalline photovoltaic modules which are selected in that study. However, for a system including a glass covered collector and localised in Macon area in France, we show that the annual photovoltaic cell efficiency is 6.8% which represents a decrease of 28% in comparison with a conventional non-integrated PV module of 9.4% annual efficiency. This is obviously due to a temperature increase related to the cover. On the other hand, we show that without a glass cover, the efficiency is 10% which is 6% better than a standard module due to the cooling effect. Moreover, in the case of a glazed PV/T collector with a conventional control system for Direct Solar Floor, the maximum temperature reached at the level of the PV modules is higher than 100{sup o}C. This is due to the oversize of the collectors during the summer when the heating needs are null, i.e. without a heated swimming pool for example. This temperature level does not allow the use of EVA resin (ethylene vinyl acetate) in PV modules due to strong risks of degradation. The current solution consists of using amorphous cells or, if we do not enhance the thermal production, uncovered PV/T collector. Further research led to water hybrid PV/T solar collectors as a one-piece component, both reliable and efficient, and including the thermal absorber, the heat exchanger and the photovoltaic functions. (author)

  1. How Will Copper Contamination Constrain Future Global Steel Recycling?

    OpenAIRE

    Daehn, Katrin; Cabrera Serrenho, Andre; Allwood, Julian Mark

    2017-01-01

    Copper in steel causes metallurgical problems, but is pervasive in end-of-life scrap and cannot currently be removed commercially once in the melt. Contamination can be managed to an extent by globally trading scrap for use in tolerant applications and dilution with primary iron sources. However, the viability of long-term strategies can only be evaluated with a complete characterization of copper in the global steel system and this is presented in this paper. The copper concentration of flow...

  2. 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...

  3. 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,...

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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, ...

  13. 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.

  14. 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.

  15. Contrasting the Views and Actions of Data Collectors and Data Consumers in a Volunteer Water Quality Monitoring Project: Implications for Project Design and Management

    Directory of Open Access Journals (Sweden)

    Caren B. Cooper

    2017-12-01

    Full Text Available Data collection or generation is the primary way that the majority of volunteers advance the scientific goals of citizen science projects, but other activities such as data consumption also may influence learning, civic, and conservation outcomes. Project designers and managers balance goals for multiple outcomes and thus need to consider the influence of all project-related activities on outcomes. In a study of the kayak-based Citizen’s Water Quality Testing (CWQT Program in New York City, we compared the characteristics, perceptions, and behaviors of those collecting and using CWQT data (data collectors and those solely using the data (data consumers. Data collectors (n = 40 and consumers (n = 24 were similar in gender and political orientation, but collectors were younger, devoted more time to the project, and experienced far more face-to-face interactions related to the project. Data collectors and consumers had similar motivations for participation, except that collectors were more likely motivated by recognition for their efforts. Lack of free time was the largest barrier to participation for both types of participants, and a significantly greater barrier for consumers. Data collectors and consumers trusted volunteer-collected data more than government-collected data. Collectors and consumers both recognized multiple scientific, environmental, and social benefits associated with the project, and both were equally likely to use volunteer-collected data for a variety of purposes, such as informing decisions about conservation and recreation. Importantly, both groups were equally likely to undertake a suite of conservation behaviors. We synthesize and expand current conceptual frameworks of citizen science participation and outcomes, highlighting the need for further study to understand mechanisms and linkages between the varied activities of citizen science projects and broader social and ecological impacts. To achieve conservation goals

  16. MERCURY CONTROL WITH THE ADVANCED HYBRID PARTICULATE COLLECTOR

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  17. Mercury Control With The Advanced Hybrid Particulate Collector

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  18. Copper and silver halates

    CERN Document Server

    Woolley, EM; Salomon, M

    2013-01-01

    Copper and Silver Halates is the third in a series of four volumes on inorganic metal halates. This volume presents critical evaluations and compilations for halate solubilities of the Group II metals. The solubility data included in this volume are those for the five compounds, copper chlorate and iodate, and silver chlorate, bromate and iodate.

  19. Nanofluid Types, Their Synthesis, Properties and Incorporation in Direct Solar Thermal Collectors: A Review

    Directory of Open Access Journals (Sweden)

    Wisut Chamsa-ard

    2017-05-01

    Full Text Available The global demand for energy is increasing and the detrimental consequences of rising greenhouse gas emissions, global warming and environmental degradation present major challenges. Solar energy offers a clean and viable renewable energy source with the potential to alleviate the detrimental consequences normally associated with fossil fuel-based energy generation. However, there are two inherent problems associated with conventional solar thermal energy conversion systems. The first involves low thermal conductivity values of heat transfer fluids, and the second involves the poor optical properties of many absorbers and their coating. Hence, there is an imperative need to improve both thermal and optical properties of current solar conversion systems. Direct solar thermal absorption collectors incorporating a nanofluid offers the opportunity to achieve significant improvements in both optical and thermal performance. Since nanofluids offer much greater heat absorbing and heat transfer properties compared to traditional working fluids. The review summarizes current research in this innovative field. It discusses direct solar absorber collectors and methods for improving their performance. This is followed by a discussion of the various types of nanofluids available and the synthesis techniques used to manufacture them. In closing, a brief discussion of nanofluid property modelling is also presented.

  20. Nanofluid Types, Their Synthesis, Properties and Incorporation in Direct Solar Thermal Collectors: A Review.

    Science.gov (United States)

    Chamsa-Ard, Wisut; Brundavanam, Sridevi; Fung, Chun Che; Fawcett, Derek; Poinern, Gerrard

    2017-05-31

    The global demand for energy is increasing and the detrimental consequences of rising greenhouse gas emissions, global warming and environmental degradation present major challenges. Solar energy offers a clean and viable renewable energy source with the potential to alleviate the detrimental consequences normally associated with fossil fuel-based energy generation. However, there are two inherent problems associated with conventional solar thermal energy conversion systems. The first involves low thermal conductivity values of heat transfer fluids, and the second involves the poor optical properties of many absorbers and their coating. Hence, there is an imperative need to improve both thermal and optical properties of current solar conversion systems. Direct solar thermal absorption collectors incorporating a nanofluid offers the opportunity to achieve significant improvements in both optical and thermal performance. Since nanofluids offer much greater heat absorbing and heat transfer properties compared to traditional working fluids. The review summarizes current research in this innovative field. It discusses direct solar absorber collectors and methods for improving their performance. This is followed by a discussion of the various types of nanofluids available and the synthesis techniques used to manufacture them. In closing, a brief discussion of nanofluid property modelling is also presented.

  1. 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

  2. Extraction of Solar Wind Nitrogen and Noble Gases From the Genesis Gold Foil Collector

    Science.gov (United States)

    Schlutter, D. J.; Pepin, R. O.

    2005-12-01

    The Genesis gold foil is a bulk solar wind collector, integrating fluences from all three of the wind regimes. Pyrolytic extraction of small foil samples at Minnesota yielded He fluences, corrected for backscatter, in good agreement with measurements by on-board spacecraft instruments, and He/Ne elemental ratios close to those implanted in collector foils deployed on the lunar surface during the Apollo missions. Isotopic distributions of He, Ne and Ar are under study. Pyrolysis to temperatures above the gold melting point generates nitrogen blanks large enough to obscure the solar-wind nitrogen component. An alternative technique for nitrogen and noble gas extraction, by room-temperature amalgamation of the gold foil surface, will be discussed. Ne and Ar releases in preliminary tests of this technique on small foil samples were close to 100% of the amounts expected from the high-temperature pyrolysis yields, indicating that amalgamation quantitatively liberates gases from several hundred angstroms deep in the gold, beyond the implantation depth of most of the solar wind. Present work is focused on two problems currently interfering with accurate nitrogen measurements at the required picogram to sub-picogram levels: a higher than expected blank likely due to tiny air bubbles rolled into the gold sheet during fabrication, and the presence of a refractory hydrocarbon film on Genesis collector surfaces (the "brown stain") that, if left in place on the foil, shields the underlying gold from mercury attack. We have found, however, that the film is efficiently removed within tens of seconds by oxygen plasma ashing. Potential nitrogen contaminants introduced during the crash of the sample return canister are inert in amalgamation, and so are not hazards to the measurements.

  3. Experimental analysis on a novel solar collector system achieved by supercritical CO2 natural convection

    International Nuclear Information System (INIS)

    Chen, Lin; Zhang, Xin-Rong

    2014-01-01

    Highlights: • Supercritical CO 2 flow is proposed for natural circulation solar water heater system. • Experimental system established and consists of supercritical fluid high pressure side and water side. • Stable supercritical CO 2 natural convective flow is well induced and water heating process achieved. • Seasonal solar collector system efficiency above 60% achieved and optimization discussed. - Abstract: Solar collector has become a hot topic both in scientific research and engineering applications. Among the various applications, the hot water supply demand accounts for a large part of social energy consumption and has become one promising field. The present study deals with a novel solar thermal conversion and water heater system achieved by supercritical CO 2 natural circulation. Experimental systems are established and tested in Zhejiang Province (around N 30.0°, E 120.6°) of southeast China. The current system is designed to operate in the supercritical region, thus the system can be compactly made and achieve smooth high rate natural convective flow. During the tests, supercritical CO 2 pipe flow with Reynolds number higher than 6700 is found. The CO 2 fluid temperature in the heat exchanger can be as high as 80 °C and a stable supply of hot water above 45 °C is achieved. In the seasonal tests, relative high collector efficiency generally above 60.0% is obtained. Thermal and performance analysis is carried out with the experiment data. Comparisons between the present system and previous solar water heaters are also made in this paper

  4. Preparation and electrochemical performance of copper foam-supported amorphous silicon thin films for rechargeable lithium-ion batteries

    International Nuclear Information System (INIS)

    Li Haixia; Cheng Fangyi; Zhu Zhiqiang; Bai Hongmei; Tao Zhanliang; Chen Jun

    2011-01-01

    Research highlights: → Amorphous Si thin films have been deposited on copper foam substrate by radio-frequency (rf) magnetron sputtering. → The as-prepared Si/Cu films with interconnected 3-dimensional structure are employed as anode materials of rechargeable lithium-ion batteries, showing that the electrode properties are greatly affected by the deposition temperature. → The film electrode deposited at an optimum temperature of 300 deg. C delivers a specific capacity of ∼2900 mAh/g and a coulombic efficiency above 95% at charge/discharge current density of 0.2C after 30 cycles. → The Li + diffusion coefficiency in copper foam-supported Si thin films is determined to be 2.36 x 10 -9 cm 2 /s. → The combination of rf magnetron sputtering and cooper foam substrate is an efficient route to prepare amorphous Si films with high capacity and cyclability due to the efficient ionic diffusion and interface contact with a good conductive current collector. - Abstract: Amorphous Si thin films, which have been deposited on copper foam by radio-frequency (rf) magnetron sputtering, are employed as anode materials of rechargeable lithium-ion batteries. The morphologies and structures of the as-prepared Si thin films are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray powder diffraction (XRD). Electrochemical performance of lithium-ion batteries with the as-prepared Si films as the anode materials is investigated by cyclic voltammetry and charge-discharge measurements. The results show that the electrode properties of the prepared amorphous Si films are greatly affected by the deposition temperature. The film electrode deposited at an optimum temperature of 300 deg. C can deliver a specific capacity of ∼2900 mAh/g and a coulombic efficiency above 95% at charge/discharge current density of 0.2C after 30 cycles. The Li + diffusion coefficiency in copper foam-supported Si thin films is determined to be 2.36 x 10 -9 cm

  5. A Study on the Copper Effect on gold leaching in copper-ethanediamine-thiosulphate solutions

    Science.gov (United States)

    Liu, Qiong; Xiang, Pengzhi; Huang, Yao

    2018-01-01

    A simple, fast and sensitive square-wave voltammetry (SWV), cyclic voltammetry(CV) and tafel method for the determination of various factors of gold in thiosulphate solution in this paper. We present our study on the effect of copper(II) on the leaching of gold in thiosulphate solutions. The current study aims to establish the interaction of copper in the leaching process by electrochemical method.

  6. Flat plate solar collector for water pre-heating using concentrated solar power (CSP)

    Science.gov (United States)

    Peris, Leonard Sunny; Shekh, Md. Al Amin; Sarker, Imran

    2017-12-01

    Numerous attempt and experimental conduction on different methods to harness energy from renewable sources are being conducted. This study is a contribution to the purpose of harnessing solar energy as a renewable source by using flat plate solar collector medium to preheat water. Basic theory of solar radiation and heat convection in water (working fluid) has been combined with heat conduction process by using copper tubes and aluminum absorber plate in a closed conduit, covered with a glazed through glass medium. By this experimental conduction, a temperature elevation of 35°C in 10 minutes duration which is of 61.58% efficiency range (maximum) has been achieved. The obtained data and experimental findings are validated with the theoretical formulation and an experimental demonstration model. A cost effective and simple form of heat energy extraction method for space heating/power generation has been thoroughly discussed with possible industrial implementation possibilities. Under-developed and developing countries can take this work as an illustration for renewable energy utilization for sustainable energy prospect. Also a full structure based data to derive concentrated solar energy in any geographical location of Bangladesh has been outlined in this study. These research findings can contribute to a large extent for setting up any solar based power plant in Bangladesh irrespective of its installation type.

  7. 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.

  8. 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.

  9. Multilevel Dual Damascene copper interconnections

    Science.gov (United States)

    Lakshminarayanan, S.

    Copper has been acknowledged as the interconnect material for future generations of ICs to overcome the bottlenecks on speed and reliability present with the current Al based wiring. A new set of challenges brought to the forefront when copper replaces aluminum, have to be met and resolved to make it a viable option. Unit step processes related to copper technology have been under development for the last few years. In this work, the application of copper as the interconnect material in multilevel structures with SiO2 as the interlevel dielectric has been explored, with emphasis on integration issues and complete process realization. Interconnect definition was achieved by the Dual Damascene approach using chemical mechanical polishing of oxide and copper. The choice of materials used as adhesion promoter/diffusion barrier included Ti, Ta and CVD TiN. Two different polish chemistries (NH4OH or HNO3 based) were used to form the interconnects. The diffusion barrier was removed during polishing (in the case of TiN) or by a post CMP etch (as with Ti or Ta). Copper surface passivation was performed using boron implantation and PECVD nitride encapsulation. The interlevel dielectric way composed of a multilayer stack of PECVD SiO2 and SixNy. A baseline process sequence which ensured the mechanical and thermal compatibility of the different unit steps was first created. A comprehensive test vehicle was designed and test structures were fabricated using the process flow developed. Suitable modifications were subsequently introduced in the sequence as and when processing problems were encountered. Electrical characterization was performed on the fabricated devices, interconnects, contacts and vias. The structures were subjected to thermal stressing to assess their stability and performance. The measurement of interconnect sheet resistances revealed lower copper loss due to dishing on samples polished using HNO3 based slurry. Interconnect resistances remained stable upto 400o

  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. Utilization of Copper Alloys for Marine Applications

    Science.gov (United States)

    Drach, Andrew

    Utilization of copper alloy components in systems deployed in marine environment presents potential improvements by reducing maintenance costs, prolonging service life, and increasing reliability. However, integration of these materials faces technological challenges, which are discussed and addressed in this work, including characterization of material performance in seawater environment, hydrodynamics of copper alloy components, and design procedures for systems with copper alloys. To characterize the hydrodynamic behavior of copper alloy nets, mesh geometry of the major types of copper nets currently used in the marine aquaculture are analyzed and formulae for the solidity and strand length are proposed. Experimental studies of drag forces on copper alloy net panels are described. Based on these studies, empirical values for normal drag coefficients are proposed for various types of copper netting. These findings are compared to the previously published data on polymer nets. It is shown that copper nets exhibit significantly lower resistance to normal currents, which corresponds to lower values of normal drag coefficient. The seawater performance (corrosion and biofouling) of copper alloys is studied through the field trials of tensioned and untensioned specimens in a one-year deployment in the North Atlantic Ocean. The corrosion behavior is characterized by weight loss, optical microscopy, and SEM/EDX analyses. The biofouling performance is quantified in terms of the biomass accumulation. To estimate the effects of stray electrical currents on the seawater corrosion measurements, a low cost three-axis stray electric current monitoring device is designed and tested both in the lab and in the 30-day field deployment. The system consists of a remotely operated PC with a set of pseudo-electrodes and a digital compass. The collected data is processed to determine magnitudes of AC and DC components of electric field and dominant AC frequencies. Mechanical behavior of

  12. 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.

  13. A facility for the testing and repair of primary collectors of steam generators at WWER nuclear power plants

    International Nuclear Information System (INIS)

    Herman, M.; Kuna, M.

    1990-01-01

    A facility labelled ZOKPG-1 has been developed for in-service inspection and repair of steam generator collectors in WWER-440 nuclear power plants. The facility makes possible visual, capillary, luminescence and ultrasonic inspection and eddy current testing of the internal surface, base material and welded joints of the collector. The repair modules of the ZOKPG-1 manipulator enable electroerosive elimination of surface defects of the material and local electrochemical decontamination of the internal surfaces. The manipulator can be operated at temperatures up to 40 degC, humidity up to 100%, and in conditions of radiation load up to 15 mGy/h and of surface contamination on the order of 100 Bq/cm 2 . (Z.M.). 16 figs

  14. Copper carrier protein in copper toxic sheep liver

    Energy Technology Data Exchange (ETDEWEB)

    Harris, A L; Dean, P D.G.

    1973-01-01

    The livers of copper-toxic sheep have been analyzed by gel electrophoresis followed by staining the gels for copper with diethyldithiocarbamate and for protein with amido schwartz. These gels were compared with similar gels obtained from the livers of normal and copper-deficient animals. The copper-toxic livers contained an extra protein band which possessed relatively weakly bound copper. Possible origins of this protein are discussed. 8 references, 1 figure, 2 tables.

  15. COPPER CABLE RECYCLING TECHNOLOGY

    International Nuclear Information System (INIS)

    Chelsea Hubbard

    2001-01-01

    The United States Department of Energy (DOE) continually seeks safer and more cost-effective technologies for use in deactivation and decommissioning (D and D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE's Office of Science and Technology (OST) sponsors large-scale demonstration and deployment projects (LSDDPs). At these LSDDPs, developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE's projects and to others in the D and D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased costs of operation. The Idaho National Engineering and Environmental Laboratory (INEEL) generated a list of statements defining specific needs and problems where improved technology could be incorporated into ongoing D and D tasks. One such need is to reduce the volume of waste copper wire and cable generated by D and D. Deactivation and decommissioning activities of nuclear facilities generates hundreds of tons of contaminated copper cable, which are sent to radioactive waste disposal sites. The Copper Cable Recycling Technology separates the clean copper from contaminated insulation and dust materials in these cables. The recovered copper can then be reclaimed and, more importantly, landfill disposal volumes can be reduced. The existing baseline technology for disposing radioactively contaminated cables is to package the cables in wooden storage boxes and dispose of the cables in radioactive waste disposal sites. The Copper Cable Recycling Technology is applicable to facility decommissioning projects at many Department of Energy (DOE) nuclear facilities and commercial nuclear power plants undergoing decommissioning activities. The INEEL Copper Cable Recycling Technology Demonstration investigated the effectiveness and efficiency to recycle 13.5 tons of copper cable. To determine the effectiveness

  16. Canine Copper-Associated Hepatitis

    NARCIS (Netherlands)

    Dirksen, Karen; Fieten, Hille

    2017-01-01

    Copper-associated hepatitis is recognized with increasing frequency in dogs. The disease is characterized by centrolobular hepatic copper accumulation, leading to hepatitis and eventually cirrhosis. The only way to establish the diagnosis is by histologic assessment of copper distribution and copper

  17. Posttranslational regulation of copper transporters

    NARCIS (Netherlands)

    van den Berghe, P.V.E.

    2009-01-01

    The transition metal copper is an essential cofactor for many redox-active enzymes, but excessive copper can generate toxic reactive oxygen species. Copper homeostasis is maintained by highly conserved proteins, to balance copper uptake, distribution and export on the systemic and cellular level.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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)

  5. 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...

  6. Automatic control of plants of direct steam generation with cylinder-parabolic solar collectors; Control automatico de plantas de generacion directa de vapor con colectores solares cilindro-parabolicos

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela Gutierrez, L.

    2008-07-01

    The main objective of this dissertation has been the contributions to the operation in automatic mode of a new generation of direct steam generation solar plants with parabolic-trough collectors. The dissertation starts introducing the parabolic-trough collectors solar thermal technology for the generation of process steam or steam for a Rankine cycle in the case of power generation generation, which is currently the most developed and commercialized technology. Presently, the parabolic-trough collectors technology is based on the configuration known as heat-exchanger system, based in the use of a heat transfer fluid in the solar field which is heated during the recirculation through the absorber tubes of the solar collectors, transferring later on the that thermal energy to a heat-exchanger for steam generation. Direct steam generation in the absorber tubes has always been shown as an ideal pathway to reduce generation cost by 15% and increase conversion efficiency by 20% (DISS, 1999). (Author)

  7. NID Copper Sample Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Zhu, Zihua

    2011-02-01

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76Ge. The DEMONSTRATOR will utilize 76Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology under development at Nonlinear Ion Dynamics (NID) will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making these isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL for isotopic analysis as a test of the NID technology. The results of that analysis are reported here.

  8. NID Copper Sample Analysis

    International Nuclear Information System (INIS)

    Kouzes, Richard T.; Zhu, Zihua

    2011-01-01

    The current focal point of the nuclear physics program at PNNL is the MAJORANA DEMONSTRATOR, and the follow-on Tonne-Scale experiment, a large array of ultra-low background high-purity germanium detectors, enriched in 76 Ge, designed to search for zero-neutrino double-beta decay (0νββ). This experiment requires the use of germanium isotopically enriched in 76 Ge. The DEMONSTRATOR will utilize 76 Ge from Russia, but for the Tonne-Scale experiment it is hoped that an alternate technology under development at Nonlinear Ion Dynamics (NID) will be a viable, US-based, lower-cost source of separated material. Samples of separated material from NID require analysis to determine the isotopic distribution and impurities. The MAJORANA DEMONSTRATOR is a DOE and NSF funded project with a major science impact. DOE is funding NID through an SBIR grant for development of their separation technology for application to the Tonne-Scale experiment. The Environmental Molecular Sciences facility (EMSL), a DOE user facility at PNNL, has the required mass spectroscopy instruments for making these isotopic measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR and for the development of the future separation technology required for the Tonne-Scale experiment. A sample of isotopically separated copper was provided by NID to PNNL for isotopic analysis as a test of the NID technology. The results of that analysis are reported here.

  9. Fabricating Copper Nanotubes by Electrodeposition

    Science.gov (United States)

    Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

    2009-01-01

    Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

  10. 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....

  11. 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.

  12. 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...

  13. 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.

  14. 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

  15. Parabolic dish collectors - A solar option

    Science.gov (United States)

    Truscello, V. C.

    1981-05-01

    A description is given of several parabolic-dish high temperature solar thermal systems currently undergoing performance trials. A single parabolic dish has the potential for generating 20 to 30 kW of electricity with fluid temperatures from 300 to 1650 C. Each dish is a complete power-producing unit, and may function either independently or as part of a group of linked modules. The two dish designs under consideration are of 11 and 12 meter diameters, yielding receiver operating temperatures of 925 and 815 C, respectively. The receiver designs described include (1) an organic working fluid (toluene) Rankine cycle engine; (2) a Brayton open cycle unit incorporating a hybrid combustion chamber and nozzle and a shaft-coupled permanent magnet alternator; and (3) a modified Stirling cycle device originally designed for automotive use. Also considered are thermal buffer energy storage and thermochemical transport and storage.

  16. Copper in the sea: a bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, R.L.

    1977-04-01

    Life in the sea is vulnerable to the influx of trace metals resulting from man's activities. Although many pollutants introduced to the sea eventually degrade to less harmful forms, trace metals accumulate in sediments and have a continued potential for effect on biota. Copper has a toxic potential exceeding all other metals due to the quantity discharged and its toxicological effect. Fortunately, copper in the oceans is rendered less bioavailable or less toxic by its ready interaction with the complex chemical components of seawater. This bibliography was prepared to illustrate the status of current knowledge of the biogeochemistry of copper and to aid the development of research programs to define the effects of copper discharged to the marine environment. The references are categorized to aid the reader to locate literature concerning specific aspects of the biogeochemistry of copper. A brief comment describing the important findings in each category is given. Although this bibliography is not exhaustive, the listed references are likely representative of current knowledge.

  17. 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.

  18. 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.

  19. 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.

  20. 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.