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Sample records for area silicon sheet

  1. 21 CFR 878.4025 - Silicone sheeting.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Silicone sheeting. 878.4025 Section 878.4025 Food... DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4025 Silicone sheeting. (a) Identification. Silicone sheeting is intended for use in the management of closed...

  2. Silicon Sheets By Redox Assisted Chemical Exfoliation

    CERN Document Server

    Tchalala, Mohamed Rachid; Enriquez, Hanna; Kara, Abdelkader; Lachgar, Abdessadek; Yagoubi, Said; Foy, Eddy; Vega, Enrique; Bendounan, Azzedine; Silly, Mathieu G; Sirotti, Fausto; Nitshe, Serge; Chaudanson, Damien; Jamgotchian, Haik; Aufray, Bernard; Mayne, Andrew J; Dujardin, Gérald; Oughaddou, Hamid

    2013-01-01

    In this paper, we report the direct chemical synthesis of silicon sheets in gram-scale quantities by chemical exfoliation of pre-processed calcium di-silicide (CaSi2). We have used a combination of X-ray photoelectron spectroscopy, transmission electron microscopy and Energy-dispersive X-ray spectroscopy to characterize the obtained silicon sheets. We found that the clean and crystalline silicon sheets show a 2-dimensional hexagonal graphitic structure.

  3. Continuous Czochralski growth: silicon sheet growth development of Large Area Silicon Sheet Task of the Low-Cost Silicon Solar Array Project. Second quarterly progress report, January 1--March 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    This project is directed toward the development of equipment and processes to produce single crystal solar silicon by a continuous Czochralski (CZ) method. ''Continuous'' is defined as the production of at least 100 kilograms of crystal from a single melt container. The approach to be taken is to suitably modify a Hamco CG2000 crystal grower to demonstrate that continuous CZ growth is feasible by the periodic replenishment of the melt container and the removal of grown crystals. The crystal growth facility is now complete with the exception of the poly weight/recharge system. Installation of this device on the grower will require disassembly of the facility to modify the growth chambers. In the meantime, hot filling experiments are being conducted by attaching poly rod material to the seed lift mechanism. The work has progressed to the point where a suitable means of melt replenishment has been demonstrated. A poly-crystalline rod of silicon can be lowered into the crucible and melted at rates of over 14 kg/hr. Using this method of hot filling, a 12'' x 9'' high crucible was charged with 25 kg of silicon and a zero dislocation, 22 kg crystal 11.4 cm diameter, 87 cm long, was grown. This demonstrates that five crystals grown from a 12 inch crucible can satisfy the continuous CZ criterion. A growth rate of 7.3 cm/hr was achieved corresponding to a continuous throughput of 1.1 kg/hr. An economic model using the SAMICS/IPEG guidelines has shown that the add-on cost of CZ crystal growth can meet the 1982 goals without any technical breakthroughs, but an add-on cost reduction of approximately 50% is necessary to meet the 1986 goal, assuming reasonable slicing yields.

  4. Quantitative analysis of defects in silicon: silicon sheet growth development for the Large Area Silicon Sheet Task of the Low-Cost Solar Array Project. Quarterly progress report No. 5, April 1-June 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Natesh, R.; Smith, J.M.; Qidwai, H.A.; Bruce, T.

    1979-07-12

    During this reporting period a computer program was written for the PDP 11/03 computer that controls the Quantimet 720 Image Analyzing System (QTM 720). This program will facilitate the analysis of silicon samples on the upgraded Quantimet 720 System. Also during this period thirty-two (32) Motorola samples were analyzed for twin boundaries, dislocation pits, and grain boundaries. A discussion of the computer program and the data obtained from the thirty-two (32) Motorola samples are given. The use of the Image Editor on the QTM 720 detected image is also described.

  5. Silicon Ingot Casting - Heat Exchanger Method (HEM). Multi-Wire Slicing - Fixed Abrasive Slicing Technique (Fast). Phase 4 Silicon Sheet Growth Development for the Large Area Sheet Task of the Low-Cost Solar Array Project

    Science.gov (United States)

    Schmid, F.

    1981-01-01

    The crystallinity of large HEM silicon ingots as a function of heat flow conditions is investigated. A balanced heat flow at the bottom of the ingot restricts spurious nucleation to the edge of the melted-back seed in contact with the crucible. Homogeneous resistivity distribution over all the ingot has been achieved. The positioning of diamonds electroplated on wirepacks used to slice silicon crystals is considered. The electroplating of diamonds on only the cutting edge is described and the improved slicing performance of these wires evaluated. An economic analysis of value added costs of HEM ingot casting and band saw sectioning indicates the projected add on cost of HEM is well below the 1986 allocation.

  6. Silicon Ingot Casting - Heat Exchanger Method Multi-wire Slicing - Fixed Abrasive Slicing Technique. Phase 3 Silicon Sheet Growth Development for the Large Area Sheet Task of the Low-cost Solar Array Project

    Science.gov (United States)

    Schmid, F.; Khattak, C. P.

    1979-01-01

    Several 20 cm diameter silicon ingots, up to 6.3 kg. were cast with good crystallinity. The graphite heat zone can be purified by heating it to high temperatures in vacuum. This is important in reducing costs and purification of large parts. Electroplated wires with 45 um synthetic diamonds and 30 um natural diamonds showed good cutting efficiency and lifetime. During slicing of a 10 cm x 10 cm workpiece, jerky motion occurred in the feed and rocking mechanisms. This problem is corrected and modifications were made to reduce the weight of the bladeheat by 50%.

  7. Binding Graphene Sheets Together Using Silicon: Graphene/Silicon Superlattice

    OpenAIRE

    Zhang Yong; Tsu Raphael

    2010-01-01

    Abstract We propose a superlattice consisting of graphene and monolayer thick Si sheets and investigate it using a first-principles density functional theory. The Si layer is found to not only strengthen the interlayer binding between the graphene sheets compared to that in graphite, but also inject electrons into graphene, yet without altering the most unique property of graphene: the Dirac fermion-like electronic structure. The superlattice approach represents a new direction for exploring ...

  8. Binding Graphene Sheets Together Using Silicon: Graphene/Silicon Superlattice

    Directory of Open Access Journals (Sweden)

    Zhang Yong

    2010-01-01

    Full Text Available Abstract We propose a superlattice consisting of graphene and monolayer thick Si sheets and investigate it using a first-principles density functional theory. The Si layer is found to not only strengthen the interlayer binding between the graphene sheets compared to that in graphite, but also inject electrons into graphene, yet without altering the most unique property of graphene: the Dirac fermion-like electronic structure. The superlattice approach represents a new direction for exploring basic science and applications of graphene-based materials.

  9. Silicon Sheet Growth Development for the Large Area Sheet Task of the Low Cost Solar Array Project. Heat Exchanger Method - Ingot Casting Fixed Abrasive Method - Multi-Wire Slicing

    Science.gov (United States)

    Schmid, F.; Khattak, C. P.

    1978-01-01

    Solar cells fabricated from HEM cast silicon yielded up to 15% conversion efficiencies. This was achieved in spite of using unpurified graphite parts in the HEM furnace and without optimization of material or cell processing parameters. Molybdenum retainers prevented SiC formation and reduced carbon content by 50%. The oxygen content of vacuum cast HEM silicon is lower than typical Czochralski grown silicon. Impregnation of 45 micrometers diamonds into 7.5 micrometers copper sheath showed distortion of the copper layer. However, 12.5 micrometers and 15 micrometers copper sheath can be impregnated with 45 micrometers diamonds to a high concentration. Electroless nickel plating of wires impregnated only in the cutting edge showed nickel concentration around the diamonds. This has the possibility of reducing kerf. The high speed slicer fabricated can achieve higher speed and longer stroke with vibration isolation.

  10. Polycrystalline Silicon Sheets for Solar Cells by the Improved Spinning Method

    Science.gov (United States)

    Maeda, Y.; Yokoyama, T.; Hide, I.

    1984-01-01

    Cost reduction of silicon materials in the photovoltaic program of materials was examined. The current process of producing silicon sheets is based entirely on the conventional Czochralski ingot growth and wafering used in the semiconductor industry. The current technology cannot meet the cost reduction demands for producing low cost silicon sheets. Alternative sheet production processes such as unconventional crystallization are needed. The production of polycrystalline silicon sheets by unconventional ingot technology is the casting technique. Though large grain sheets were obtained by this technique, silicon ribbon growth overcomes deficiencies of the casting process by obtaining the sheet directly from the melt. The need to solve difficulties of growth stability and impurity effects are examined. The direct formation process of polycrystalline silicon sheets with large grain size, smooth surface, and sharp edges from the melt with a high growth rate which will yield low cost silicon sheets for solar cells and the photovoltaic characteristics associated with this type of sheet to include an EBIC study of the grain boundaries are described.

  11. Temporomandibular joint ankylosis fixation technique with ultra thin silicon sheet

    Directory of Open Access Journals (Sweden)

    G S Kalra

    2011-01-01

    Full Text Available Background: Temporomandibular joint ankylosis is a highly distressing condition in which the joint space is obliterated by scar tissue and the patient has an inability to open the mouth. Different autogenous and alloplastic interposition materials have been used after the resection of the ankylotic bone to achieve desirable and long lasting results. The recurrence of disease is most distressing for both patients and surgeon. We have been using ultra thin silicon sheet as our preferred material for providing proper fixation and cover to the joint. We have been encouraged by good patient compliance, no implant extrusion and favourable outcome. Materials and Methods: The clinical study included 80 patients with temporomandibular joint ankylosis, treated between April 2001 and March 2009. In all patients, temporomandibular joint ankylosis had resulted following trauma. Diagnosis was based on clinical assessment supplemented by radiographic examination consisting of a panoramic radiograph, axial and coronal computer tomography. The technique of using ultra thin silicon sheet covering whole of the joint space fixed with non-absorbable nylon 3-0 suture both medially to medial pterygoid muscle and laterally to periosteum of zygomatic arch was employed in all patients. Results: A total of 80 patients were in this study (59 males and 21 females. The aetiology of temporomandibular joint ankylosis was post-traumatic in all cases. The patients′ age ranged from 5 to 45 years. The disease was unilateral in 61 cases and bilateral in 19 cases. Twelve patients, who had previous surgery done in the form of gap arthroplasty in 6 cases, costochondral graft in 4 cases and temporalis muscle in 2 cases, presented with recurrence on the same side. The pre-op inter-incisal mouth opening ranged from 4 to 12 mm. The intraoperative inter-incisal mouth opening ranged from 28 to 46 mm. An additional procedure was done in 13 patients, including placement of costochondral

  12. Calculated and Experimental Research of Sheet Resistances of Laser-Doped Silicon Solar Cells

    Science.gov (United States)

    Li, Tao; Wang, Wen-Jing

    2015-02-01

    The calculated and experimental research of sheet resistances of crystalline silicon solar cells by dry laser doping is investigated. The nonlinear numerical model on laser melting of crystalline silicon and liquid-phase diffusion of phosphorus atoms by dry laser doping is analyzed by the finite difference method implemented in MATLAB. The melting period and melting depth of crystalline silicon as a function of laser energy density is achieved. The effective liquid-phase diffusion of phosphorus atoms in melting silicon by dry laser doping is confirmed by the rapid decrease of sheet resistances in experimental measurement. The plateau of sheet resistances is reached at around 15Ω/□. The calculated sheet resistances as a function of laser energy density is obtained and the calculated results are in good agreement with the corresponding experimental measurement. Due to the successful verification by comparison between experimental measurement and calculated results, the simulation results could be used to optimize the virtual laser doping parameters.

  13. Magnetic Properties and Workability of 6.5% Si Steel Sheet Manufactured by Siliconizing Process

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A siliconizing process to manufacture 6.5% Si steel sheet has been developed. Electric compo nents, such as transformers and reactors are made easily from 6.5% Si steel sheet. However, improved workability is desirable to increase the applications. Therefore the improvement of workability of 6.5% Si steel sheet was investigated, and the results were obtained as follows: (a) workability of 6.5% Si steel sheet is deteriorated by grain boundary oxidization, (b) grain boundary oxidization can be restrained by the addition of C. Workability and magnetic properties of 6.5% Si steel sheet with C addition are discussed. Furthermore, it was found that the work ability of high Si steel sheet was improved remarkably by varying the Si content gradient along the thickness without deterioration of high frequency magnetic properties. This newly developed magnetic gradient high Si steel sheet is also discussed.

  14. Large area sheet from P/M materials

    International Nuclear Information System (INIS)

    A P/M process has been developed that provides a means of producing large area thin sheets of cemented tungsten carbide or heavy metal alloys. The process employs a flowable slurry comprising a liquid vehicle and the solid particulate material. The resulting slurry composition can be formed into sheets, or it can be shaped in a mold cavity. The slurry upon exposure to the atmosphere, and either with or without the application of heat, will set up in a dimensionally stable form and can, thereafter, be sintered to form a solid article. Any fraction of the vehicle which remains after the solvent evaporates, vaporizes during sintering and the final product consists only of the particulate material in sintered form. Typical uses for the cemented tungsten carbide sheets are for wear applications. The heavy metal alloy sheets typically are used in applications where high density materials are required

  15. Large area cylindrical silicon drift detector

    International Nuclear Information System (INIS)

    An advanced silicon drift detector, a large area cylindrical drift detector, was designed, produced, tested and installed in the NA45 experiment. The active area of the detector is practically the total area of a 3 inch diameter wafer. Signal electrons created in the silicon detector by fast charged particles drift radially outside toward an array of 360 anodes located on the periphery of the detector. The drift time measures the radial coordinate of the particle's intersection; the charge sharing between anodes measures the azimuthal coordinate. The detector provides unambiguous pairs of r,φ coordinates for events with multiplicities up to several hundred. Its use in the experiment aims at a position resolution of 20 μm (rms) in each direction giving about 2 · 106 two-dimensional elements. There is a small hole in the center of the detector to allow the passage of the noninteracting particle beam. The longest drift distance is about 3 cm. The nominal value of the drift field is 500 V/cm resulting in a maximum drift time of 4 μs

  16. Large area cylindrical silicon drift detector

    International Nuclear Information System (INIS)

    This paper reports on an advanced silicone drift detector, a large area cylindrical drift detector that was designed, produced, tested and installed in the Na45 experiment. The active area of the detector is practically the total area of a 3 inch diameter wafer. Signal electrons created in the silicon detector by fast charged particles drift radially outside toward an array of 360 anodes located on the periphery of the detector. The drift time measures the radial coordinate of the particle's intersection; the charge sharing between anodes measures the azimuthal coordinate. The detector provides unambiguous pairs of r, φ coordinates for events with multiplicities up to several hundred. Its use in the experiment aims at a position resolution of 20 μm (rms) in each direction giving about 2 · 106 two-dimensional elements. There is a small hole in the center of the detector to allow the passage of the noninteracting particle beam. The longest drift distance is about 3 cm. The nominal value of the drift field is 500 V/cm resulting in a maximum drift time of 4 μs

  17. Geology of the Brewood area, 1:10000 sheet SJ80NE : part of 1:50000 sheet 153 (Wolverhampton)

    OpenAIRE

    Hough, E.

    1998-01-01

    This report describes the geology of 1:lO 000 sheet SJ 80 NE (Brewood) which is included in 1 :50 000 Geological Sheet 153 (Wolverhampton) (Figure 1). The sheet area (hereafter referred to as the ‘district’) was first geologically surveyed at the 1 : 10 560 scale by H. Dewey, E. E. L. Dixon and R. L. Sherlock between 19 1 5 and 192 1, and published on Staffordshire County Series sheets 49SE, 50SW, 55NE, 55SE, 56NW and 56SW. The one-inch Geological Sheet 153 (Wolverhampton) was ...

  18. The Relationship Between Hot and Cold Rolling Parameters and Secondary Recrystallization Behavior in Silicon Steel Sheets

    Science.gov (United States)

    Jahangiri, Mohammadreza

    2015-08-01

    The effect of different hot and cold rolling process variables was evaluated for the secondary recrystallization behavior of silicon steel sheets, and a simple model was developed. On the basis of the model, the following results can be drawn: (a) for complete secondary recrystallization of silicon steel sheets, rolling of cast ingots must precede MnS precipitation start; (b) if it is necessitated, intermediate annealing during hot rolling passes must be carried out in the temperature of about 1000 °C; (c) during hot rolling, the amount of initial strain before the intermediate annealing of rolled strips at 1000 °C must be >70% reduction in thickness; (d) in the two-stage cold rolling method, the thickness reduction in the second cold rolling stage must be rolling method with two intermediate anneals.

  19. Characterization of an amorphous silicon flat panel for controlling the positioning accuracy of sheet

    International Nuclear Information System (INIS)

    It has established a method for measuring the position of the blades in a multi leaf collimator (MLC) used to measure dose portal imaging device (EPID) of amorphous silicon, and verified its accuracy using radiochromic films and measures water with diode Cuba, techniques perfectly well validated in our institution. This dose profiles are studied for each sheet and determine their position at the point which has 50% of the dose in the open field.

  20. Large-area Silicon-Film{trademark} panels and solar cells. Phase 2 technical report, January 1996--December 1996

    Energy Technology Data Exchange (ETDEWEB)

    Rand, J.A.; Barnett, A.M.; Checchi, J.C.; Culik, J.S.; Collins, S.R.; Ford, D.H.; Hall, R.B.; Jackson, E.L.; Kendall, C.L. [AstroPower Inc., Newark, DE (United States)

    1997-03-01

    The Silicon-Film{trademark} process is on an accelerated path to large-scale manufacturing. A key element in that development is optimizing the specific geometry of both the Silicon-Film{trademark} sheet and the resulting solar cell. That decision has been influenced by cost factors, engineering concerns, and marketing issues. The geometry investigation has focused first on sheet nominally 15 cm wide. This sheet generated solar cells with areas of 240 cm{sup 2} and 675 cm{sup 2}. Most recently, a new sheet fabrication machine was constructed that produces Silicon-Film{trademark} with a width in excess of 30 cm. Test results have indicated that there is no limit to the width of sheet generated by this process. The new wide material has led to prototype solar cells with areas of 300, 400, and 1,800 cm{sup 2}. Significant advances in solar-cell processing have been developed in support of fabricating large-area devices, including uniform emitter diffusion and anti-reflection coatings.

  1. Nanosized graphene sheets enhanced photoelectric behavior of carbon film on p-silicon substrate

    Science.gov (United States)

    Yang, Lei; Hu, Gaijuan; Zhang, Dongqing; Diao, Dongfeng

    2016-07-01

    We found that nanosized graphene sheets enhanced the photoelectric behavior of graphene sheets embedded carbon (GSEC) film on p-silicon substrate, which was deposited under low energy electron irradiation in electron cyclotron resonance plasma. The GSEC/p-Si photodiode exhibited good photoelectric performance with photoresponsivity of 206 mA/W, rise and fall time of 2.2, and 4.3 μs for near-infrared (850 nm) light. The origin of the strong photoelectric behavior of GSEC film was ascribed to the appearance of graphene nanosheets, which led to higher barrier height and photoexcited electron-collection efficiency. This finding indicates that GSEC film has the potential for photoelectric applications.

  2. Sheet resistance uniformity in drive-in step for different multi-crystalline silicon wafer dispositions

    Energy Technology Data Exchange (ETDEWEB)

    Moussi, A.; Bouhafs, D.; Mahiou, L. [Laboratoire des Cellules Photovoltaiques, Unite de Developpement de la Technologie du Silicium, 2 Bd, Frantz Fanon, B.P. 140, 7 Merveilles Alger (Algeria); Belkaid, M.S. [Dep. Electronique, Faculte de Genie Electrique et Informatique, UMMTO (Algeria)

    2009-09-15

    In this work, we present a study of emitters realized using different configurations of the silicon wafers in the quartz boat. The phosphorous liquid source is sprayed onto p-type multi-crystalline silicon substrates and the drive-in is made at high temperature in a muffle furnace. Three different configurations of the wafers in the boat are tested: separated, back to back and compact block of wafers. A fourth configuration is also used in source-receptor mode. The emitter phosphorous concentration profile is obtained by SIMS analysis. The resulting emitters are characterized by sheet resistance measurements and a comparison is made between the wafers within the same batch and from one batch to another. The uniformity and the standard deviation of the sheet resistance are calculated in each case. The emitter sheet resistance mapping of the wafer set in the middle of the boat for a given process gives a mean R{sub sq} 14.66 {omega}/sq with a standard deviation of 1.76% and uniformity of 18.7%. Standard deviations of 2.116% and 1.559% are obtained for wafers in the batch when using the spaced and compact configurations, respectively. The standard deviation is reduced to 0.68% when the wafers are used in source/receptor mode. A comparison is also made between wafers with different dilution of phosphorous source in ethanol. From these results we can conclude that the compact configuration offers better uniformity and lower standard deviation. Furthermore, when combined with the source-receptor configuration these parameters are significantly improved. This study allows the experimenter to identify the technological parameters of the solar cell emitter manufacturing and target precisely the desired values of the sheet resistance while limiting the number of rejected wafers. (author)

  3. Large-area silicon detection in hadronic sampling calorimetry

    International Nuclear Information System (INIS)

    The usage of a maximum size silicon wafer area was optimized by using a geometry with two trapezoidal detectors, each of 28 cm2. In order to enable the use of silicon detectors for hadron calorimeters a mosaic module consisting of 18 trapezoidal detectors was developed and assembled. Laser cutting technique was employed to minimize the dead area of the mosaic. In the performed investigations no physical deterioration was observed. (orig.)

  4. Gamma Large Area Silicon Telescope (GLAST)

    International Nuclear Information System (INIS)

    The recent discoveries and excitement generated by EGRET have prompted an investigation into modern technologies ultimately leading to the next generation space-based gamma ray telescope. The goal is to design a detector that will increase the data acquisition rate by almost two orders of magnitude beyond EGRET, while at the same time improving on the angular resolution, the energy measurement of reconstructed gamma rays, and the triggering capability of the instrument. The GLAST proposal is based on the assertion that silicon particle detectors are the technology of choice for space application: no consumables, no gas volume, robust (versus fragile), long lived, and self triggering. The GLAST detector is roughly modeled after EGRET in that a tracking module precedes a calorimeter. The GLAST Tracker has planes of thin radiatior interspersed with planes of crossed-strip (x,y) 300-μm-pitch silicon detectors to measure the coordinates of converted electron-positron pairs. The gap between the layers (∼5 cm) provides a lever arm in track fitting resulting in an angular resolution of 0.1 degree at high energy (the low energy angular resolution at 100 MeV would be about 2 degree, limited by multiple scattering). A possible GLAST calorimeter is made of a mosaic of Csl crystals of order 10 r.l. in depth, with silicon photodiodes readout. The increased depth of the GLAST calorimeter over EGRET's extends the energy range to about 300 GeV

  5. Gamma Large Area Silicon Telescope (GLAST)

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, G.L.

    1993-11-01

    The recent discoveries and excitement generated by EGRET have prompted an investigation into modern technologies ultimately leading to the next generation space-based gamma ray telescope. The goal is to design a detector that will increase the data acquisition rate by almost two orders of magnitude beyond EGRET, while at the same time improving on the angular resolution, the energy measurement of reconstructed gamma rays, and the triggering capability of the instrument. The GLAST proposal is based on the assertion that silicon particle detectors are the technology of choice for space application: no consumables, no gas volume, robust (versus fragile), long lived, and self triggering. The GLAST detector is roughly modeled after EGRET in that a tracking module precedes a calorimeter. The GLAST Tracker has planes of thin radiatior interspersed with planes of crossed-strip (x,y) 300-{mu}m-pitch silicon detectors to measure the coordinates of converted electron-positron pairs. The gap between the layers ({approximately}5 cm) provides a lever arm in track fitting resulting in an angular resolution of 0.1{degree} at high energy (the low energy angular resolution at 100 MeV would be about 2{degree}, limited by multiple scattering). A possible GLAST calorimeter is made of a mosaic of Csl crystals of order 10 r.l. in depth, with silicon photodiodes readout. The increased depth of the GLAST calorimeter over EGRET`s extends the energy range to about 300 GeV.

  6. Area monitor for neutrons with thin sheet of Au

    International Nuclear Information System (INIS)

    A passive area monitor for neutrons with an activation detector was designed and constructed to be used in sites where the radiation field is mixed, intense and pulsed, like happens in the radiotherapy rooms that use lineal accelerators of medical use or in enclosures with cyclotrons for PET, or where the field is mixed and intense as in the nuclear power plants. This equipment is useful for the exposition cases of the patients or workers that receive not counted radiation dose, generating harmful effects to the health, for what is necessary to take the pertinent measures for the radiological protection. The design of the area monitor was realized using the MCNP5 code, where was considered an activation detector and therefore thin sheets of Au-197 located in the moderator center were used. The moderator was designed as a polyethylene cylindrical to moderate the neutrons. The gold was used like detector for its high cross section and its physical and chemical characteristics. The response of the monitor is maxim for energies from 1 to 20 MeV, region where the flowing coefficients and dose are majors. Therefore, the designed and constructed monitor can be used in sites with high, mixed and pulsed radiation fields. (Author)

  7. A New Efficient-Silicon Area MDAC Synapse

    Directory of Open Access Journals (Sweden)

    Zied Gafsi

    2007-01-01

    Full Text Available Using the binary representation in the Multiplier digital to analog converter (MDAC synapse designs have crucial drawbacks. Silicon area of transistors, constituting the MDAC circuit, increases exponentially according to the number of bits. This latter is generated by geometric progression of common ratio equal to 2. To reduce this exponential increase to a linear growth, a new synapse named Arithmetic MDAC (AMDAC is designed. It functions with a new representation based on arithmetic progressions. Using the AMS CMOS 0.35µm technology the silicon area is reduced by a factor of 40%.

  8. Developmental experiments on large-area silicon solar cells

    Science.gov (United States)

    Silard, Andrei P.; Nani, Gabriel

    1989-05-01

    Practical ways of attenuating the severe limitations imposed by areal inhomogeneities on the performance of large-area solar cells fabricated on both p- and n-silicon wafers are described, and the results of tests are presented. The p(+)-n-n(+) and n(+)-p-p(+) cells were processed as bifacial devices and tested under both frontside and backside AM1 illumination. It is shown that the combination of a simple design and some of the technological approaches evaluated in this study result in low-cost high-efficiency large-area bifacial silicon solar cells that exhibit with good electrooptical performance.

  9. Beam test of a large area silicon drift detector

    International Nuclear Information System (INIS)

    The results from the tests of the first large area (4x4 cm2) planar silicon drift detector prototyp in a pion beam are reported. The measured position resolution in the drift direction is σ=40±10 μm. (orig.)

  10. Synthesis and Characterization of Silicon Nanoparticles Inserted into Graphene Sheets as High Performance Anode Material for Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Yong Chen

    2014-01-01

    Full Text Available Silicon nanoparticles have been successfully inserted into graphene sheets via a novel method combining freeze-drying and thermal reduction. The structure, electrochemical performance, and cycling stability of this anode material were characterized by SEM, X-ray diffraction (XRD, charge/discharge cycling, and cyclic voltammetry (CV. CV showed that the Si/graphene nanocomposite exhibits remarkably enhanced cycling performance and rate performance compared with bare Si nanoparticles for lithium ion batteries. XRD and SEM showed that silicon nanoparticles inserted into graphene sheets were homogeneous and had better layered structure than the bare silicon nanoparticles. Graphene sheets improved high rate discharge capacity and long cycle-life performance. The initial capacity of the Si nanoparticles/graphene keeps above 850 mAhg−1 after 100 cycles at a rate of 100 mAg−1. The excellent cycle performances are caused by the good structure of the composites, which ensured uniform electronic conducting sheet and intensified the cohesion force of binder and collector, respectively.

  11. Small area silicon diffused junction x-ray detectors

    International Nuclear Information System (INIS)

    The low temperature performance of silicon diffused junction detectors in the measurement of low energy x-rays is reported. The detectors have an area of 0.04 cm2 and a thickness of 100 μm. The spectral resolutions of these detectors were found to be in close agreement with expected values indicating that the defects introduced by the high temperature processing required in the device fabrication were not deleteriously affecting the detection of low energy x-rays. Device performance over a temperature range of 77 to 1500K is given. These detectors were designed to detect low energy x-rays in the presence of minimum ionizing electrons. The successful application of silicon diffused junction technology to x-ray detector fabrication may facilitate the development of other novel silicon x-ray detector designs

  12. Large-area microlens arrays fabricated on flexible polycarbonate sheets via single-step laser interference ablation

    International Nuclear Information System (INIS)

    A single-step method for the fabrication of large-area microlens arrays on flexible polycarbonate sheets is described. On areas of approximately 1 cm2, 17 million to 120 million microlenses ranging in size from sub-micrometer to several micrometers are fabricated via deep-UV pulsed laser interference ablation. The uniformity and surface quality of fabricated microlens arrays are examined and confirmed through atomic force microscopy and scanning electron microscopy. Optical imaging performance of the microlenses, and their use in massively parallel, pulsed laser nanofabrication on silicon is demonstrated. The microlens arrays can be fabricated in a matter of seconds, suggesting the potential for fast and low-cost production on flexible plastic substrates.

  13. A New Efficient-Silicon Area MDAC Synapse

    OpenAIRE

    Zied Gafsi; Nejib Hassen; Mongia Mhiri; Kamel Besbes

    2007-01-01

    Using the binary representation in the Multiplier digital to analog converter (MDAC) synapse designs have crucial drawbacks. Silicon area of transistors, constituting the MDAC circuit, increases exponentially according to the number of bits. This latter is generated by geometric progression of common ratio equal to 2. To reduce this exponential increase to a linear growth, a new synapse named Arithmetic MDAC (AMDAC) is designed. It functions with a new representation based on arithmetic progr...

  14. Spatial Non-uniformity Measurements of Large Area Silicon Photodiodes

    OpenAIRE

    DURAK, Murat; SAMADOV, Farhad; TÜRKOĞLU, A. Kamuran

    2002-01-01

    Accurate determination of the responsivity of silicon photodiodes are highly desired in photometry. The change of responsivity over the surface, the so-called spatial non-uniformity, effects power measurements especially in photodiodes with large active areas. To study this effect, first an intensity-stabilized laser source-optics has been established. A purpose-built step-motor controlled two axis micro mechanical stage has been designed to scan the photodiode surface. In this stu...

  15. Synthesis and Characterization of Silicon Nanoparticles Inserted into Graphene Sheets as High Performance Anode Material for Lithium Ion Batteries

    OpenAIRE

    Yong Chen; Xuejun Zhang; Yanhong Tian; Xi Zhao

    2014-01-01

    Silicon nanoparticles have been successfully inserted into graphene sheets via a novel method combining freeze-drying and thermal reduction. The structure, electrochemical performance, and cycling stability of this anode material were characterized by SEM, X-ray diffraction (XRD), charge/discharge cycling, and cyclic voltammetry (CV). CV showed that the Si/graphene nanocomposite exhibits remarkably enhanced cycling performance and rate performance compared with bare Si nanoparticles for lithi...

  16. Large area high efficiency multicrystalline silicon solar cell

    Science.gov (United States)

    Shirasawa, Katsuhiko; Yamashita, Hironori; Fukui, Kenji; Takayama, Michihiro; Okada, Kenichi

    A high-efficiency, low-cost large-area multicrystalline silicon solar cell having a cell size of 15 cm x 15 cm and a substrate made by the casting method has been developed. The bifacial silicon nitride solar cell (BSNSC) fabrication process was used to construct the cell. By incorporating a new structure at the cell surface, an optimized back-surface field (BSF) process, and an electrode with a ratio of 5.2 percent into the BSNSC fabrication process, a conversion efficiency of 15.1 percent (global, AM1.5, 100 mW/sq cm, 25 C) has been obtained. The uniformity of the electrical performance of the cell has been studied by measuring the distribution of the spectral response at various points on the cell. The results of uniformity testing are presented.

  17. Climatology and firn processes in the lower accumulation area of the Greenland ice sheet

    OpenAIRE

    Charalampidis, Charalampos

    2016-01-01

    The Greenland ice sheet is the largest Northern Hemisphere store of fresh water, and it is responding rapidly to the warming climate. In situ observations document the changing ice sheet properties in the lower accumulation area, Southwest Greenland. Firn densities from 1840 meters above sea level retrieved in May 2012 revealed the existence of a 5.5-meter-thick, near-surface ice layer in response to the recent increased melt and refreezing in firn. As a consequence, vertical meltwater percol...

  18. Controllable chemical vapor deposition of large area uniform nanocrystalline graphene directly on silicon dioxide

    DEFF Research Database (Denmark)

    Sun, Jie; Lindvall, Niclas; Cole, Matthew T.;

    2012-01-01

    graphene) and up to 13% of electric-field effect. The Hall mobility is similar to 40 cm(2)/ Vs, which is an order of magnitude higher than previously reported values for nanocrystalline graphene. Transmission electron microscopy, Raman spectroscopy, and transport measurements indicate a graphene......Metal-catalyst-free chemical vapor deposition (CVD) of large area uniform nanocrystalline graphene on oxidized silicon substrates is demonstrated. The material grows slowly, allowing for thickness control down to monolayer graphene. The as-grown thin films are continuous with no observable pinholes......, and are smooth and uniform across whole wafers, as inspected by optical-, scanning electron-, and atomic force microscopy. The sp(2) hybridized carbon structure is confirmed by Raman spectroscopy. Room temperature electrical measurements show ohmic behavior (sheet resistance similar to exfoliated...

  19. Bay Area Transit Agencies Propel Fuel Cell Buses Toward Commercialization (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    This fact sheet describes the Zero Emission Bay Area (ZEBA) demonstration of the next generation of fuel cells buses. Several transit agencies in the San Francisco Bay Area are participating in demonstrating the largest single fleet of fuel cell buses in the United States.

  20. Geology of the Beckbury and Worfield area, 1:10000 sheets SJ70SE & SO79NE : part of 1:50000 sheet 153 (Wolverhampton) and 167 (Dudley)

    OpenAIRE

    Hough, E.; Barnett, A. J.

    1998-01-01

    This report describes the geology of 1:lO 000 sheets SJ 70 SE (Beckbury) and SO 79 NE (Worfield) (Figure 1). This area was first surveyed geologically at the 1:lO 560 scale by R W Pocock and T Robertson in 1922 and 1923, and published on County Sheets Staffordshire 44SW, 44SE and 61SW, and Shropshire 52NW, 52NE, 52SW, 52SE, 59NW and 59NE. The one-inch Geological Sheet 153 (Wolverhampton) was published in 1929, and the accompanying sheet memoir (Whitehead et al.) dates fiom 1928...

  1. Innovative carbon nanotube-silicon large area photodetector

    International Nuclear Information System (INIS)

    We report on a new photodetector fabricated using carbon nanostructures grown on a silicon substrate. This device exhibits low noise, a good conversion efficiency of photons into electrical current and a good signal linearity in a wide range of radiation wavelengths ranging from ultraviolet to infrared at room temperature. The maximum quantum efficiency of 37% at 880 nm has been measured without signal amplification. Such innovative devices can be easily produced on large scales by Chemical Vapour Deposition (CVD) through a relatively inexpensive chemical process, which allows large sensitive areas from a few mm2 up to hundreds of cm2 to be covered.

  2. Low cost, large area silicon detectors for calorimetry

    International Nuclear Information System (INIS)

    Trapezoidal detectors with 28 cm2 active area have been fabricated on >2500 Ωcm, 4 in. diameter n-type silicon wafers. Instead of the commonly used ion implantation method, low-cost, high volume solid state diffusion technology along with phosphosilicate-glass and TCA gettering was adopted for boron and phosphorus doping. Typically the diode dark current was 15 μA at sign 100 volts. Efforts are being made to obtain a finished device yield of 80% to meet the $2/cm2 price goal of SSC semiconductor detector group. 20 refs., 4 figs

  3. Preparation of High Silicon Electrical Steel Sheets with Strong {100} Recrystallization Texture by the Texture Inheritance of Initial Columnar Grains

    Science.gov (United States)

    Pan, Hongjiang; Zhang, Zhihao; Xie, Jianxin

    2016-05-01

    Texture evolutions and recrystallization texture features in warm- and cold-rolled sheets of high silicon electrical steel with two different initial microstructures (columnar-grained and equiaxed-grained microstructures) were investigated. The relationships between the recrystallization textures and the initial textures (the textures before rolling) of the samples were analyzed. The results showed that after annealing at 1073 K (800 °C) for 1 hour, strong {100} recrystallization textures with volume fractions of more than 47 pct were obtained in the columnar-grained samples fabricated by warm and cold rolling along the growing direction of the columnar grains. While after rolling and annealing in the same processes, only 12.8 pct volume fractions of {100} recrystallization texture were revealed in the equiaxed-grained samples. The formation of strong {100} recrystallization texture in the annealed sheets of high silicon electrical steel with initial columnar grains was attributed to the favorable texture inheritance of the initial texture during rolling and annealing. The columnar grains of strong near {100} ({100} {310}) orientation in the samples before rolling were transferred into deformed grains with orientations such as {100} and {100}. after rolling. Afterwards, these deformed grains were further transferred into {100} oriented recrystallized grains, which formed strong {100} recrystallization texture in the annealed sheets and exhibited preferable soft magnetic properties.

  4. Geology of the Sherrifhales area, 1:10000 sheet SJ71SE and part of SJ71NE : part of 1:50000 sheet 153 (Wolverhampton)

    OpenAIRE

    Hough, E.

    1997-01-01

    This report describes the geology of 1 :10 000 sheet SJ 71 SE (Sheriflhales) and the southern part of SJ 71 NE (Newport East), south of northing 317 (Figure 1). This area was first surveyed geologically at the 1 :10 560 scale by E E L Dixon and T H Whitehead between 1919 and 1924 and published on County Sheets Staffordshire 43SW, 49NW, and Shropshire 3 lSW, 37NW, 37SW and 37SE. The one-inch Geological Sheet 153 (Wolverhampton), which includes both areas, was published in 1929, ...

  5. Accurate potential drop sheet resistance measurements of laser-doped areas in semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Heinrich, Martin, E-mail: mh.seris@gmail.com [Solar Energy Research Institute of Singapore, National University of Singapore, Singapore 117574 (Singapore); NUS Graduate School for Integrative Science and Engineering, National University of Singapore, Singapore 117456 (Singapore); Kluska, Sven; Binder, Sebastian [Fraunhofer Institute for Solar Energy Systems (ISE), Heidenhofstrasse 2, D-79110 Freiburg (Germany); Hameiri, Ziv [The School of Photovoltaic and Renewable Energy Engineering, The University of New South Wales, Sydney NSW 2052 (Australia); Hoex, Bram [Solar Energy Research Institute of Singapore, National University of Singapore, Singapore 117574 (Singapore); Aberle, Armin G. [Solar Energy Research Institute of Singapore, National University of Singapore, Singapore 117574 (Singapore); NUS Graduate School for Integrative Science and Engineering, National University of Singapore, Singapore 117456 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117456 (Singapore)

    2014-10-07

    It is investigated how potential drop sheet resistance measurements of areas formed by laser-assisted doping in crystalline Si wafers are affected by typically occurring experimental factors like sample size, inhomogeneities, surface roughness, or coatings. Measurements are obtained with a collinear four point probe setup and a modified transfer length measurement setup to measure sheet resistances of laser-doped lines. Inhomogeneities in doping depth are observed from scanning electron microscope images and electron beam induced current measurements. It is observed that influences from sample size, inhomogeneities, surface roughness, and coatings can be neglected if certain preconditions are met. Guidelines are given on how to obtain accurate potential drop sheet resistance measurements on laser-doped regions.

  6. Chemical Vapor Deposition Synthesis and Raman Spectroscopic Characterization of Large-Area Graphene Sheets

    Science.gov (United States)

    Liao, Chun-Da; Lu, Yi-Ying; Tamalampudi, Srinivasa Reddy; Cheng, Hung-Chieh; Chen, Yit-Tsong

    2013-10-01

    We present a chemical vapor deposition (CVD) method to catalytically synthesize large-area, transferless, single- to few-layer graphene sheets using hexamethyldisilazane (HMDS) on a SiO2/Si substrate as a carbon source and thermally evaporated alternating Ni/Cu/Ni layers as a catalyst. The as-synthesized graphene films were characterized by Raman spectroscopic imaging to identify single- to few-layer sheets. This HMDS-derived graphene layer is continuous over the entire growth substrate, and single- to trilayer mixed sheets can be up to 30 -m in the lateral dimension. With the synthetic CVD method proposed here, graphene can be grown into tailored shapes directly on a SiO2/Si surface through vapor priming of HMDS onto predefined photolithographic patterns. The transparent and conductive HMDS-derived graphene exhibits its potential for widespread electronic and opto-electronic applications.

  7. The temperature effect on mechanical properties of silicon carbide sheet based on density functional treatment

    Science.gov (United States)

    Faghihnasiri, Mahdi; Rezvani, Mahyar; Shabani, Mostafa; Firouzian, Amir Hossein

    2016-02-01

    In the current work, mechanical properties of SiC graphene sheet and influence of temperature on those properties are studied. The purpose of this work is to investigate the temperature dependency of the Young's modulus and Bulk's modulus of SiC graphene sheet. To reach these goals, density functional theory (DFT) and quasi-harmonic approximation (QHA) methods are used to calculate energies of electrons and phonons, and consequently to obtain total energy of system. Results have been compared with existing data from literature and good agreement has been found. It is found that the effect of temperature on the mechanical properties of the SiC graphene sheet is significant.

  8. The STAR silicon vertex tracker: a large area silicon drift detector

    CERN Document Server

    Lynn, D; Beuttenmüller, Rolf H; Caines, H; Chen, W; Dimassimo, D; Dyke, H; Elliot, D; Eremin, V; Grau, M; Hoffmann, G W; Humanic, T; Ilyashenko, Yu S; Kotov, I; Kraner, H W; Kuczewski, P; Leonhardt, B; Li, Z; Liaw, C J; Lo Curto, G; Middelkamp, P; Minor, R; Munhoz, M; Ott, G; Pandey, S U; Pruneau, C A; Rykov, V L; Schambach, J; Sedlmeir, J; Soja, B; Sugarbaker, E R; Takahashi, J; Wilson, K; Wilson, R

    2000-01-01

    The Solenoidal Tracker At RHIC-Silicon Vertex Tracker (STAR-SVT) is a three barrel microvertex detector based upon silicon drift detector technology. As designed for the STAR-SVT, silicon drift detectors (SDDs) are capable of providing unambiguous two-dimensional hit position measurements with resolutions on the order of 20 mu m in each coordinate. Achievement of such resolutions, particularly in the drift direction coordinate, depends upon certain characteristics of silicon and drift detector geometry that are uniquely critical for silicon drift detectors hit measurements. Here we describe features of the design of the STAR-SVT SDDs and the front-end electronics that are motivated by such characteristics.

  9. Reinforced Epoxy Nanocomposite Sheets Utilizing Large Interfacial Area from a High Surface Area Single-Walled Carbon Nanotube Scaffold

    Science.gov (United States)

    Kobashi, Kazufumi; Nishino, Hidekazu; Yamada, Takeo; Futaba, Don; Yumura, Motoo; Hata, Kenji

    2011-03-01

    We employed single-walled carbon nanotubes (SWNTs) with the available highest specific surface area (more than 1000 m2/g) that provided very large interfacial area for the matrix to fabricate epoxy composite sheets. Through mechanical redirection of the SWNT alignment to horizontal to create a laterally aligned scaffold sheet, into which epoxy resin was impregnated. The SWNT scaffold was engineered in structure to meet the these two nearly mutually exclusive demands, i.e. to have nanometer meso-pores (2-50 nm) to facilitate homogeneous impregnation of the epoxy resin and to have mechanical strength to tolerate the compaction forces generated during impregnation. Through this approach, a SWNT/epoxy composite sheet with a nearly ideal morphology was realized where long and aligned SWNTs were loaded at high weight fraction (33 percent) with an intertube distance approaching the radius of gyration for polymers. The resultant composite showed a Young's modulus of 15.0 GPa and a tensile strength of 104 MPa, thus achieving 5.4 and 2.1 times reinforcement as compared to the neat epoxy resin.

  10. Texture Development in High-Silicon Iron Sheet Produced by Simple Shear Deformation

    Science.gov (United States)

    Kustas, Andrew B.; Sagapuram, Dinakar; Trumble, Kevin P.; Chandrasekar, Srinivasan

    2016-06-01

    Sheet processing of high Si-Fe alloys (up to 6.5 wt pct Si) is demonstrated by application of highly confined shear deformation in cutting-extrusion. This alloy system, of major interest to electromagnetic applications, is characterized by poor workability. By a suitable interactive combination of simple shear, high strain rates, near-adiabatic heating, and large hydrostatic pressure in the deformation zone, flow localization, and cracking inherent to this alloy system are suppressed. This enables creation of sheet and foil forms from bulk ingots, cast or wrought, in a single deformation step, unlike rolling. The sheet is characterized by strong shear textures, described by partial {110} and fibers, and fine-grained microstructures ( 20 µm grain size). The orientation (inclination) of these fibers, with respect to the sheet surface, can be varied over a range of 35 deg through selection of the deformation path. In contrast to rolling textures, the current shear deformation textures are negligibly influenced by recrystallization annealing. A recovery-based continuous recrystallization mechanism is proposed to explain the texture retention. Some general implications for shear-based processing of alloys of limited workability are discussed.

  11. Evaluation of molten area in micro-welding of monocrystalline silicon and glass

    Science.gov (United States)

    Nordin, I. H. W.; Okamoto, Y.; Miyamoto, I.; Okada, A.

    2016-02-01

    Characteristics of the molten area in micro-welding of monocrystalline silicon and glass are described. In this study, 4 types of laser beam, which are nanosecond pulsed laser and picosecond pulsed laser of 532 nm and 1064 nm in wavelength were used for joining monocrystalline silicon and glass. Influence of wavelength and pulse duration on microwelding of monocrystalline silicon and glass was experimentally investigated under the same spot diameter, and the molten area of monocrystalline silicon and glass was characterized. A splash area of molten silicon with 532 nm wavelength was wider than that with 1064 nm in a nanosecond pulse laser. However, its splash area of molten silicon with 1064 nm changed drastically at certain pulse energy of 11 μJ in a nanosecond pulse laser. On the other hand, 12.5 ps pulsed laser still kept a stable molten area appearance even at pulse energy of 11 μJ. A splash area of molten silicon around the weld bead line was obvious in the nanosecond pulsed laser. On the other hand, there was no remarkable molten splash around the weld bead line in the picosecond pulsed laser. It is concluded that the combination of picosecond pulse duration and infrared wavelength leads to a stable molten area appearance of the weld bead.

  12. Contact-free sheet resistance determination of large area graphene layers by an open dielectric loaded microwave cavity

    International Nuclear Information System (INIS)

    A method for contact-free determination of the sheet resistance of large-area and arbitrary shaped wafers or sheets coated with graphene and other (semi) conducting ultrathin layers is described, which is based on an open dielectric loaded microwave cavity. The sample under test is exposed to the evanescent resonant field outside the cavity. A comparison with a closed cavity configuration revealed that radiation losses have no significant influence of the experimental results. Moreover, the microwave sheet resistance results show good agreement with the dc conductivity determined by four-probe van der Pauw measurements on a set of CVD samples transferred on quartz. As an example of a practical application, correlations between the sheet resistance and deposition conditions for CVD graphene transferred on quartz wafers are described. Our method has a high potential as measurement standard for contact-free sheet resistance measurement and mapping of large area graphene samples

  13. High-efficiency cell concepts on low-cost silicon sheets

    Science.gov (United States)

    Bell, R. O.; Ravi, K. V.

    1985-01-01

    The limitations on sheet growth material in terms of the defect structure and minority carrier lifetime are discussed. The effect of various defects on performance are estimated. Given these limitations designs for a sheet growth cell that will make the best of the material characteristics are proposed. Achievement of optimum synergy between base material quality and device processing variables is proposed. A strong coupling exists between material quality and the variables during crystal growth, and device processing variables. Two objectives are outlined: (1) optimization of the coupling for maximum performance at minimal cost; and (2) decoupling of materials from processing by improvement in base material quality to make it less sensitive to processing variables.

  14. Selective-area laser deposition (SALD) Joining of silicon carbide with silicon carbide filler

    Science.gov (United States)

    Harrison, Shay Llewellyn

    Selective Area Laser Deposition (SALD) is a gas-phase, solid freeform fabrication (SFF) process that utilizes a laser-driven, pyrolytic gas reaction to form a desired solid product. This solid product only forms in the heated zone of the laser beam and thus can be selectively deposited by control of the laser position. SALD Joining employs the SALD method to accomplish 'welding' of ceramic structures together. The solid reaction product serves as a filler material to bond the two parts. The challenges involved with ceramic joining center around the lack of a liquid phase, little plastic deformation and diffusivity and poor surface wetting for many ceramic materials. Due to these properties, traditional metal welding procedures cannot be applied to ceramics. Most alternative ceramic welding techniques use some form of a metal addition to overcome these material limitations. However, the metal possesses a lower ultimate use temperature than the ceramic substrate and therefore it decreases the temperature range over which the joined part can be safely used. SALD Joining enjoys several advantages over these ceramic welding procedures. The solid filler material chemistry can be tailored to match the type of ceramic substrate and therefore fabricate monolithic joints. The SALD filler material bonds directly to the substrate and the joined structure is made in a one step process, without any post-processing. The research documented in this dissertation focused on SALD Joining of silicon carbide structures with silicon carbide filler material. A historical progression of gas-phase SFF research and a literature review of the most prominent ceramic joining techniques are provided. A variety of SiC substrates were examined, as were various conditions of gas precursor pressures and mixtures, laser beam scan speed and joint configuration. The SALD material was characterized for composition and structure by x-ray diffraction, transmission electron microscopy and nuclear magnetic

  15. Prediction of power losses in silicon iron sheets under PWM voltage supply

    International Nuclear Information System (INIS)

    The behavior of iron losses in silicon iron steels submitted to a PWM voltage is studied. The influence of modulation parameters (the depth of modulation and the number of eliminated harmonics) is clarified. In particular, the idea of an equivalent alternating pulse voltage that gives the same iron losses as the PWM voltage is established. An estimation formula for iron losses under the PWM voltage is developed based on the loss separation model and the voltage form factor. ((orig.))

  16. Hypertrophic scar model in the rabbit ear: a reproducible model for studying scar tissue behavior with new observations on silicone gel sheeting for scar reduction.

    Science.gov (United States)

    Kloeters, Oliver; Tandara, Andrea; Mustoe, Thomas A

    2007-01-01

    Hypertrophic scarring poses a clinically relevant problem as it can be cosmetically disfiguring and functionally debilitating. A lack of animal models has hindered an understanding of the pathogenesis and development of new treatment strategies therefore has largely been empiric. Our group has developed a unique hypertrophic scar (HS) model in the rabbit ear. The model has been reproducible, quantifiable, and measurable over a time period of 1 month. We describe the development as well as the reliability and responsiveness of this model to different therapeutic agents, such as TGF-beta blockade, silicone occlusion, and application of collagen-synthesis inhibitors. Moreover, it has given insights into the mechanism of action of silicone sheeting occlusive treatment and ultimately suggests that the epidermis plays a critical role in the development of HS. Additionally, we will present new data supporting the importance of the epidermis and further clarify the mechanism of action of silicone sheeting. When a semi-occlusive polyurethane film was left in place for an additional time period, scar formation was reduced. HSs of this model covered with silicone sheets and five layers of Tegaderm showed a significant scar reduction by 80% compared with wounds with only one layer of Tegaderm. The HS model in the rabbit ear is a highly reliable, responsive, and practical model for studying scar tissue behavior. Furthermore, our data suggest that the degree and the duration of occlusion are most important for reducing scar tissue formation. PMID:17727466

  17. 水溶性硅钢片漆在微电机中的应用%Application of Water Soluble Silicon Steel Sheet in Micromotor

    Institute of Scientific and Technical Information of China (English)

    李巧; 陈峰; 赵振; 刘佳; 党晓斌

    2015-01-01

    旋变微电机铁心制造一般采用冲片涂漆叠压的工艺。目前的硅钢片漆的稀释剂主要是由松节油等化学品组成,对操作者的健康有一些影响,并且不能达到环保的要求。新型的硅钢片漆以自来水为溶剂,经济环保,有利于劳动者保护。水溶性硅钢片漆绝缘性能更加优异且不需要额外增加新的设备,提高了生产质量,达到了环保要求。通过理论分析和实验验证,结果表明,水溶性硅钢片漆用于旋变微电机冲片涂漆是可行的。%rotating micromotor core manufacturing generally adopts punching laminated painting process .The silicon steel sheet varnish thinner is mainly composed of turpentine and other chemicals , the operator′s health have some impact , and do not meet environmental requirements .New type of silicon steel sheet paint with tap water as solvent , economic environment , is conducive to the protection of workers .Water soluble silicon steel sheet insulation performance is more excellent and does not need to add new equipment , improve the production quality , to meet the requirements of environmental protection .Through theoretical analysis and experimental verification , the results show that the water soluble silicon steel sheet paint is used for rotating micro motor punching sheet painting is feasible .

  18. Erosion by pleistocene continental ice sheets in the area of the Canadian Shield

    International Nuclear Information System (INIS)

    The principles, theory and knowledge on the behaviour of glaciers indicate that only confined glacier flow is a major erosional agent. Unconfined, areally flowing ice sheets such as those present over the Canadian Shield during the Pleistocene Period modified the landscape very little. The potential for deep glacial erosion in future glaciations over the Canadian Shield area is low. Nuclear waste disposal sites, based only upon potential glacial erosion, should be located a few hundred meters below the surface in competent, fractureless crystalline shield bedrock, in relatively reliefless terrain, a few hundred kilometers away from the Paleozoic boundary. (auth)

  19. Formation of silicon hydride using hyperthermal negative hydrogen ions (H-) extracted from an argon-seeded hydrogen sheet plasma source

    International Nuclear Information System (INIS)

    An E x B probe (a modified Wien filter) is constructed to function both as a mass spectrometer and ion implanter. The device, given the acronym EXBII selects negative hydrogen ions (H-) from a premixed 10% argon-seeded hydrogen sheet plasma. With a vacuum background of 1.0 x 10-6 Torr, H- extraction ensues at a total gas feed of 1.8 mTorr, 0.5 A plasma discharge. The EXBII is positioned 3 cm distance from the sheet core as this is the region densely populated by cold electrons (Te ∼ 2 eV, Ne ∼ 3.4 x 1011 cm-3) best suited for H- formation. The extracted H- ions of flux density ∼0.26 A/m2 are segregated, accelerated to hyperthermal range (2, n-type Si (1 0 0) substrate held at the rear end of the EXBII, placed in lieu of its Faraday cup. The palladium membrane plays the role of a catalyst initiating the reaction between Si atoms and H- ions simultaneously capping the sample from oxidation and other undesirable adsorbents. AFM and FTIR characterization tests confirm the formation of SiH2. Absorbance peaks between 900-970 cm-1 (bending modes) and 2050-2260 cm-1 (stretching modes) are observed in the FTIR spectra of the processed samples. It is found that varying hydrogen exposure time results in the shifting of wavenumbers which may be interpreted as changes in the frequencies of vibration for SiH2. These are manifestations of chemical changes accompanying alterations in the force constant of the molecule. The sample with longer exposure time exhibits an additional peak at 2036 cm-1 which are hydrides of nano-crystalline silicon.

  20. A Silicon UCN Detector With Large Area and With Analysis of UCN Polarization

    OpenAIRE

    Lasakov, M.; Serebrov, A.; Khusainov, A.; Pustovoit, A.; Borisov, Yu.; Fomin, A.; Geltenbort, P; Kon’kov, O.; Kotina, I.; Shablii, A.; Solovei, V.; Vasiliev, A.

    2005-01-01

    A silicon ultracold neutron (UCN) detector with an area of 45 cm2 and with a 6LiF converter is developed at St. Petersburg Nuclear Physics Institute (PNPI). The spectral efficiency of the silicon UCN detector was measured by means of a gravitational spectrometer at Institut Max von Laue – Paul Langevin (ILL). The sandwich-type detector from two silicon plates with a 6LiF converter placed between them was also studied. Using this type of technology the UCN detector with analysis of polarizatio...

  1. A large area silicon UCN detector with the analysis of UCN polarization

    Science.gov (United States)

    Lasakov, M. S.; Serebrov, A. P.; Khusainov, A. Kh.; Pustovoit, A.; Borisov, Yu. V.; Fomin, A. K.; Geltenbort, P.; Kon'kov, O. I.; Kotina, I. M.; Shablii, A. I.; Solovei, V. A.; Vasiliev, A. V.

    2005-06-01

    A silicon UCN detector with an area of 45 cm2 and with a 6LiF converter was developed at PNPI. The spectral efficiency of the silicon UCN detector was measured by means of a gravitational spectrometer at ILL. The sandwich-type detector from two silicon plates with a 6LiF converter placed between them was also studied. Using this type of technology the UCN detector with analysis of polarization was developed and tested. The analyzing power of this detector assembly reaches up to 75% for the main part of UCN spectrum. This UCN detector with analysis of UCN polarization can be used in the new EDM spectrometer.

  2. Sol-gel preparation of low oxygen content, high surface area silicon nitride and imidonitride materials.

    Science.gov (United States)

    Sardar, Kripasindhu; Bounds, Richard; Carravetta, Marina; Cutts, Geoffrey; Hargreaves, Justin S J; Hector, Andrew L; Hriljac, Joseph A; Levason, William; Wilson, Felix

    2016-04-01

    Reactions of Si(NHMe)4 with ammonia are effectively catalysed by small ammonium triflate concentrations, and can be used to produce free-standing silicon imide gels. Firing at various temperatures produces amorphous or partially crystallised silicon imidonitride/nitride samples with high surface areas and low oxygen contents. The crystalline phase is entirely α-Si3N4 and structural similarities are observed between the amorphous and crystallised materials. PMID:26931152

  3. Development of large area silicon detectors for calorimetrics applications

    International Nuclear Information System (INIS)

    P-I-N diodes, operating partially or fully depleted, have been made with a planar process with a high resistivity 3k-6k ohm cm (111) FZ silicon. The reliability and repeatability of the process is guaranteed by the techniques already known and used in production of discrete power devices, with appropriate adaptation. The processes developed is IC compatible. The leakage control is obtained by reducing residual ion implantation damage with high temperature annealing and by proved gettering techniques. A value of 5 nA/cm2 has been obtained. (orig.)

  4. Closure Report for Corrective Action Unit 329: Area 22 Desert Rock Airstrip Fuel Spill with Errata Sheet, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Navarro Nevada Environmental Services

    2010-08-10

    In Appendix 0, Use Restriction (UR) Form, the drawing of the use restricted area shows the incorrect coordinates for the use restricted area, the coordinates on the drawing do not match the approved UR Form. The coordinates have been verified and this Errata Sheet replaces the drawing of the use restricted area with an aerial photo showing the use restricted area and the correct coordinates that match the approved UR Form.

  5. Effect of texture and grain size on the magnetic flux density and core loss of cold-rolled high silicon steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Jing [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Yang, Ping, E-mail: yangp@mater.ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Mao, Weimin [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Ye, Feng [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-11-01

    The effects of texture and grain size on the magnetic flux density and core loss (50–20 kHz) of 0.23 mm-thick cold-rolled high silicon steel sheets are investigated by means of electron back-scattered diffraction (EBSD), loss separation, and anisotropy parameter (ε) calculation. A model of the hysteresis loss coefficient k{sub h} considering average grain size and ε is established. The magnetic flux density at 800 A/m (B{sub 8}) is closely related to the volume fraction of η-fiber-oriented grains, while the magnetic flux density at 5000 A/m (B{sub 50}) is closely related to the volume fractions of γ- and λ-fiber-oriented grains in high silicon steel. The hysteresis loss of high silicon steel can be greatly reduced by increasing the grain size and optimizing the texture of the sheets. Although increases in frequencies decrease the effect of texture on core loss, the effect cannot be ignored. As annealing temperature and time increase, the relative difference in core loss between the rolling direction (RD) and the transverse direction (TD) is maintained at higher frequencies because of increases in grain size, decreases in γ texture, and maintenance of a strong η texture. Texture and grain size jointly affect the high-frequency core loss of high silicon steel. - Highlights: • A model of hysteresis loss coefficient considering anisotropy parameter is obtained. • Effect of texture on high-frequency core loss of high-silicon steel cannot be ignored. • Texture and grain size jointly affect high-frequency core loss of high-silicon steel.

  6. Effect of texture and grain size on the magnetic flux density and core loss of cold-rolled high silicon steel sheets

    International Nuclear Information System (INIS)

    The effects of texture and grain size on the magnetic flux density and core loss (50–20 kHz) of 0.23 mm-thick cold-rolled high silicon steel sheets are investigated by means of electron back-scattered diffraction (EBSD), loss separation, and anisotropy parameter (ε) calculation. A model of the hysteresis loss coefficient kh considering average grain size and ε is established. The magnetic flux density at 800 A/m (B8) is closely related to the volume fraction of η-fiber-oriented grains, while the magnetic flux density at 5000 A/m (B50) is closely related to the volume fractions of γ- and λ-fiber-oriented grains in high silicon steel. The hysteresis loss of high silicon steel can be greatly reduced by increasing the grain size and optimizing the texture of the sheets. Although increases in frequencies decrease the effect of texture on core loss, the effect cannot be ignored. As annealing temperature and time increase, the relative difference in core loss between the rolling direction (RD) and the transverse direction (TD) is maintained at higher frequencies because of increases in grain size, decreases in γ texture, and maintenance of a strong η texture. Texture and grain size jointly affect the high-frequency core loss of high silicon steel. - Highlights: • A model of hysteresis loss coefficient considering anisotropy parameter is obtained. • Effect of texture on high-frequency core loss of high-silicon steel cannot be ignored. • Texture and grain size jointly affect high-frequency core loss of high-silicon steel

  7. The use of large area silicon sensors for thermal neutron detection

    International Nuclear Information System (INIS)

    The use of large area planar silicon detectors coupled with gadolinium foils has been investigated to develop a thermal neutron detector having a large area-efficiency (Aε) product. Noise levels due to high detector capacitance limit the size of silicon detectors that can be utilized. Calculations using the Monte Carlo code, MCNP, have been made to determine the variation of intrinsic detection efficiency as a function of the discriminator threshold level required to eliminate the detector noise. Measurements of the noise levels for planar silicon detectors of various resistivities (400, 3000 and 5000 Ω cm) have been made and the optimal detector area-efficiency products have been determined. The response of a Si-Gd-Si sandwich detector with areas between 1 cm2 and 10.5 cm2 is presented and the effects of the detector capacitance and reverse current are discussed. ((orig.))

  8. Development of large area and thin silicon dE/dX detectors

    International Nuclear Information System (INIS)

    The aim of this report is to demonstrate the feasibility of thin dE/dX detectors of large areas with today available ultrathin silicon membranes. With a fast and easy manufacturing procedure, very performant surface barriers with areas up to 1010 mm2 and about 50 μm thick have been realized

  9. High surface area silicon carbide-coated carbon aerogel

    Science.gov (United States)

    Worsley, Marcus A; Kuntz, Joshua D; Baumann, Theodore F; Satcher, Jr, Joe H

    2014-01-14

    A metal oxide-carbon composite includes a carbon aerogel with an oxide overcoat. The metal oxide-carbon composite is made by providing a carbon aerogel, immersing the carbon aerogel in a metal oxide sol under a vacuum, raising the carbon aerogel with the metal oxide sol to atmospheric pressure, curing the carbon aerogel with the metal oxide sol at room temperature, and drying the carbon aerogel with the metal oxide sol to produce the metal oxide-carbon composite. The step of providing a carbon aerogel can provide an activated carbon aerogel or provide a carbon aerogel with carbon nanotubes that make the carbon aerogel mechanically robust. Carbon aerogels can be coated with sol-gel silica and the silica can be converted to silicone carbide, improved the thermal stability of the carbon aerogel.

  10. Fabrication of large-area concave microlens array on silicon by femtosecond laser micromachining.

    Science.gov (United States)

    Deng, Zefang; Yang, Qing; Chen, Feng; Meng, Xiangwei; Bian, Hao; Yong, Jiale; Shan, Chao; Hou, Xun

    2015-05-01

    In this Letter, a novel fabrication of large-area concave microlens array (MLA) on silicon is demonstrated by combination of high-speed laser scanning, which would result in single femtosecond laser pulse ablation on surface of silicon, and subsequent wet etching. Microscale concave microlenses with tunable dimensions and accessional aspherical profile are readily obtained on the 1  cm × 1  cm silicon film, which are useful as optical elements for infrared (IR) applications. The aperture diameter and height of the microlens were characterized and the results reveal that they are both proportional to the laser scanning speed. Moreover, the optical property of high-performance silicon MLAs as a reflective homogenizer was investigated for the visible wavelength, and it can be easily extended to IR light. PMID:25927750

  11. Mammography with and without radiolucent positioning sheets : Comparison of projected breast area, pain experience, radiation dose and technical image quality

    NARCIS (Netherlands)

    Timmers, Janine; ten Voorde, Marloes; van Engen, Ruben E.; van Landsveld-Verhoeven, Cary; Pijnappel, Ruud; Droogh-de Greve, Kitty; den Heeten, Gerard J.; Broeders, Mireille J. M.

    2015-01-01

    Purpose: To compare projected breast area, image quality, pain experience and radiation dose between mammography performed with and without radiolucent positioning sheets. Methods: 184 women screened in the Dutch breast screening programme (May-June 2012) provided written informed consent to have on

  12. A large area, silicon photomultiplier-based PET detector module

    Science.gov (United States)

    Raylman, R. R.; Stolin, A.; Majewski, S.; Proffitt, J.

    2014-01-01

    The introduction of silicon photomultipliers (SiPM) has facilitated construction of compact, efficient and magnetic field-hardened positron emission tomography (PET) scanners. To take full advantage of these devices, methods for using them to produce large field-of-view PET scanners are needed. In this investigation, we explored techniques to combine two SiPM arrays to form the building block for a small animal PET scanner. The module consists of a 26×58 array of 1.5×1.5 mm2 LYSO elements (spanning 41×91 mm2) coupled to two SensL SiPM arrays. The SiPMs were read out with new multiplexing electronics developed for this project. To facilitate calculation of event position with multiple SiPM arrays it was necessary to spread scintillation light amongst a number of elements with a small light guide. This method was successful in permitting identification of all detector elements, even at the seam between two SiPM arrays. Since the performance of SiPMs is enhanced by cooling, the detector module was fitted with a cooling jacket, which allowed the temperature of the device and electronics to be controlled. Testing demonstrated that the peak-to-valley contrast ratio of the light detected from the scintillation array was increased by ~45% when the temperature was reduced from 28 °C to 16 °C. Energy resolution for 511 keV photons improved slightly from 18.8% at 28 °C to 17.8% at 16 °C. Finally, the coincidence timing resolution of the module was found to be insufficient for time-of-flight applications (~2100 ps at 14 °C). The first use of these new modules will be in the construction of a small animal PET scanner to be integrated with a 3 T clinical magnetic resonance imaging scanner.

  13. A large area, silicon photomultiplier-based PET detector module

    International Nuclear Information System (INIS)

    The introduction of silicon photomultipliers (SiPM) has facilitated construction of compact, efficient and magnetic field-hardened positron emission tomography (PET) scanners. To take full advantage of these devices, methods for using them to produce large field-of-view PET scanners are needed. In this investigation, we explored techniques to combine two SiPM arrays to form the building block for a small animal PET scanner. The module consists of a 26×58 array of 1.5×1.5 mm2 LYSO elements (spanning 41×91 mm2) coupled to two SensL SiPM arrays. The SiPMs were read out with new multiplexing electronics developed for this project. To facilitate calculation of event position with multiple SiPM arrays it was necessary to spread scintillation light amongst a number of elements with a small light guide. This method was successful in permitting identification of all detector elements, even at the seam between two SiPM arrays. Since the performance of SiPMs is enhanced by cooling, the detector module was fitted with a cooling jacket, which allowed the temperature of the device and electronics to be controlled. Testing demonstrated that the peak-to-valley contrast ratio of the light detected from the scintillation array was increased by ∼45% when the temperature was reduced from 28 °C to 16 °C. Energy resolution for 511 keV photons improved slightly from 18.8% at 28 °C to 17.8% at 16 °C. Finally, the coincidence timing resolution of the module was found to be insufficient for time-of-flight applications (∼2100 ps at 14 °C). The first use of these new modules will be in the construction of a small animal PET scanner to be integrated with a 3 T clinical magnetic resonance imaging scanner

  14. A liquid-helium cooled large-area silicon PIN photodiode x-ray detector

    OpenAIRE

    Inoue, Yoshizumi; Moriyama, Shigetaka; Hara, Hideyuki; Minowa, Makoto; Shimokoshi, Fumio

    1995-01-01

    An x-ray detector using a liquid-helium cooled large-area silicon PIN photodiode has been developed along with a tailor-made charge sensitive preamplifier whose first-stage JFET has been cooled. The operating temperature of the JFET has been varied separately and optimized. The x- and $\\gamma$-ray energy spectra for an \

  15. Recent results from beam tests of large area silicon drift detectors

    International Nuclear Information System (INIS)

    Silicon drift detectors with an active area of 7.0 x 7.5 cm2 will equip the two middle layers of the Inner Tracking System of the ALICE experiment. The performance of several prototypes was studied during beam tests carried out at the CERN SPS facility. The results of the beam test data analysis are discussed in this paper

  16. Progress in amorphous silicon based large-area multijunction modules

    Science.gov (United States)

    Carlson, D. E.; Arya, R. R.; Bennett, M.; Chen, L.-F.; Jansen, K.; Li, Y.-M.; Maley, N.; Morris, J.; Newton, J.; Oswald, R. S.; Rajan, K.; Vezzetti, D.; Willing, F.; Yang, L.

    1996-01-01

    Solarex, a business unit of Amoco/Enron Solar, is scaling up its a-Si:H/a-SiGe:H tandem device technology for the production of 8 ft2 modules. The current R&D effort is focused on improving the performance, reliability and cost-effectiveness of the tandem junction technology by systematically optimizing the materials and interfaces in small-area single- and tandem junction cells. Average initial conversion efficiencies of 8.8% at 85% yield have been obtained in pilot production runs with 4 ft2 tandem modules.

  17. A Silicon UCN Detector With Large Area and With Analysis of UCN Polarization.

    Science.gov (United States)

    Lasakov, M; Serebrov, A; Khusainov, A; Pustovoit, A; Borisov, Yu; Fomin, A; Geltenbort, P; Kon'kov, O; Kotina, I; Shablii, A; Solovei, V; Vasiliev, A

    2005-01-01

    A silicon ultracold neutron (UCN) detector with an area of 45 cm(2) and with a (6)LiF converter is developed at St. Petersburg Nuclear Physics Institute (PNPI). The spectral efficiency of the silicon UCN detector was measured by means of a gravitational spectrometer at Institut Max von Laue - Paul Langevin (ILL). The sandwich-type detector from two silicon plates with a (6)LiF converter placed between them was also studied. Using this type of technology the UCN detector with analysis of polarization was developed and tested. The analyzing power of this detector assembly reaches up 75 % for the main part of UCN spectrum. This UCN detector with analysis of UCN polarization can be used in the new electric dipole moment (EDM) spectrometer. PMID:27308138

  18. Experience with silicon sensor performance and quality control for a large-area detector

    CERN Document Server

    Krammer, M

    2003-01-01

    The CMS silicon tracker, at present under construction, will consist of 10 barrel layers and 2 multiplied by 9 end cap discs inside a volume of about 5.6 m length and 2.4 m radius. The total sensitive area covered by silicon will exceed 200 m**2. To cope with the expected radiation damage induced by the particle fluence at the Large Hadron Collider the detector will be operated at -10 degree C. Two companies manufacture the 25000 silicon sensors in 15 different geometries. The delivery of the sensors is under way and hence an extensive quality control program for the sensors has been put in operation. The paper gives an overview of the CMS tracker system and subsequently concentrates on the results from the sensor tests. In addition, measurements on dedicated test structures are presented which were designed to monitor the stability of the sensor production process.

  19. Ultra long-range interactions between large area graphene and silicon.

    Science.gov (United States)

    Na, Seung Ryul; Suk, Ji Won; Ruoff, Rodney S; Huang, Rui; Liechti, Kenneth M

    2014-11-25

    The wet-transfer of graphene grown by chemical vapor deposition (CVD) has been the standard procedure for transferring graphene to any substrate. However, the nature of the interactions between large area graphene and target substrates is unknown. Here, we report on measurements of the traction-separation relations, which represent the strength and range of adhesive interactions, and the adhesion energy between wet-transferred, CVD grown graphene and the native oxide surface of silicon substrates. These were determined by coupling interferometry measurements of the separation between the graphene and silicon with fracture mechanics concepts and analyses. The measured adhesion energy was 357 ± 16 mJ/m(2), which is commensurate with van der Waals interactions. However, the deduced traction-separation relation for graphene-silicon interactions exhibited a much longer range interaction than those normally associated with van der Waals forces, suggesting that other mechanisms are present. PMID:25317979

  20. Highly efficient industrial large-area black silicon solar cells achieved by surface nanostructured modification

    Science.gov (United States)

    Li, Ping; Wei, Yi; Zhao, Zengchao; Tan, Xin; Bian, Jiming; Wang, Yuxuan; Lu, Chunxi; Liu, Aimin

    2015-12-01

    Traditional black silicon solar cells show relatively low efficiencies due to the high surface recombination occurring at the front surfaces. In this paper, we present a surface modification process to suppress surface recombination and fabricate highly efficient industrial black silicon solar cells. The Ag-nanoparticle-assisted etching is applied to realize front surface nanostructures on silicon wafers in order to reduce the surface reflectance. Through a further tetramethylammonium hydroxide (TMAH) treatment, the carrier recombination at and near the surface is greatly suppressed, due to a lower surface dopant concentration after the surface modification. This modified surface presents a low reflectivity in a range of 350-1100 nm. Large-area solar cells with an average conversion efficiency of 19.03% are achieved by using the TMAH treatment of 30 s. This efficiency is 0.18% higher than that of standard silicon solar cells with pyramidal surfaces, and also a remarkable improvement compared with black silicon solar cells without TMAH modifications.

  1. Large-area sheet task: advanced dendritic web growth development. Quarterly report, October 23-December 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, C. S.; Seidensticker, R. G.; McHugh, J. P.; Hopkins, R. H.; Meier, D.; Frantti, E.; Schruben, J.

    1981-01-31

    Silicon dendritic web is a single crystal ribbon form of silicon capable of fabrication into solar cells with AM1 conversion efficiency in excess of 15%. Progress on a study to demonstrate the technology readiness of the web process to meet the national goals for low cost photovoltaic power is reported. Several refinements were introduced into the sensing and control equipment for melt replenishment during web growth and also several areas were identified for cost reduction in the components of the prototype automated web growth furnace. A new circuit has been designed, assembled and tested to eliminate the sensitivity of the detector signal to the intensity of the reflected laser beam used to measure melt level. Noise due to vibrations on the silicon melt surface has also been eliminated. A new variable speed motor has been identified for the silicon feeder. Pellet feeding will be accomplished at a rate programmed to match exactly the silicon removed by web growth. A system to program the initiation of web growth automatically has been designed and first tests initiated. This should eventually result in reduced labor content and improved process reproducibility. Potential cost reductions in the furnace chamber and storage reel have been identified. A furnace controller providing a functional capability similar to our experimental hardware but at about one third the cost will shortly be tested.

  2. Interference lithographically defined and catalytically etched, large-area silicon nanocones from nanowires.

    Science.gov (United States)

    Dawood, M K; Liew, T H; Lianto, P; Hong, M H; Tripathy, S; Thong, J T L; Choi, W K

    2010-05-21

    We report a simple and cost effective method for the synthesis of large-area, precisely located silicon nanocones from nanowires. The nanowires were obtained from our interference lithography and catalytic etching (IL-CE) method. We found that porous silicon was formed near the Au catalyst during the fabrication of the nanowires. The porous silicon exhibited enhanced oxidation ability when exposed to atmospheric conditions or in wet oxidation ambient. Very well located nanocones with uniform sharpness resulted when these oxidized nanowires were etched in 10% HF. Nanocones of different heights were obtained by varying the doping concentration of the silicon wafers. We believe this is a novel method of producing large-area, low cost, well defined nanocones from nanowires both in terms of the control of location and shape of the nanocones. A wide range of potential applications of the nanocone array can be found as a master copy for nanoimprinted polymer substrates for possible biomedical research; as a candidate for making sharp probes for scanning probe nanolithography; or as a building block for field emitting tips or photodetectors in electronic/optoelectronic applications. PMID:20418606

  3. Binding of carbon coated nano-silicon in graphene sheets by wet ball-milling and pyrolysis as high performance anodes for lithium-ion batteries

    Science.gov (United States)

    Sun, Wei; Hu, Renzong; Zhang, Miao; Liu, Jiangwen; Zhu, Min

    2016-06-01

    A novel approach has been developed to prepare silicon@carbon/graphene sheets (Si@C/G) composite with a unique structure, in which carbon coated Si nanoparticles are uniformly dispersed in a matrix of graphene sheets, to enhance the cycleability and electronic conductivity of Si-based anodes for Li-ion batteries. In this study, Si nanoparticles and expanded graphite (EG) are treated by combining high-energy wet ball-milling in sucrose solution with subsequent pyrolysis treatment to produce this Si@C/G composite. To achieve better overall electrochemical performance, the carbon content of the composites is also studied systematically. The as-designed Si30@C40/G30 (Si:C:G = 30:40:30, by weight) composite exhibits a high Li-storage capacity of 1259 mAh g-1 at a current density of 0.2 A g-1 in the first cycle. Further, a stable cycleability with 99.1/88.2% capacity retention from initial reversible charge capacity can be achieved over 100/300 cycles, showing great promise for batteries applications. This good electrochemical performance can be attributed to the uniform coating and binding effect of pyrolytic carbon as well as the network of graphene sheets, which increase the electronic conductivity and Li+ diffusion in the composite, and effectively accommodated the volume change of Si nanoparticles during the Li+ alloying and dealloying processes.

  4. Clean graphene interfaces by selective dry transfer for large area silicon integration

    Science.gov (United States)

    Na, S. R.; Rahimi, S.; Tao, L.; Chou, H.; Ameri, S. K.; Akinwande, D.; Liechti, K. M.

    2016-03-01

    Here we present a very fast, selective mechanical approach for transferring graphene with low levels of copper contamination from seed wafers on which it was grown to target wafers for very large scale integration (VLSI) electronics. We found that graphene/copper or copper/silicon oxide delamination paths could be selected by slow and faster separation rates, respectively. Thus graphene can be transferred to a target wafer, either exposed or protected by the seed copper layer, which can later be removed by etching. Delamination paths were identified by SEM and Raman spectroscopy. The sheet resistance of the graphene produced by the two approaches was slightly higher than graphene transferred by a PMMA wet-transfer process, indicating reduced impurity doping, and the variation in the sheet resistance values was much lower. Copper contamination levels, quantitatively established by TOF-SIMS, were several orders of magnitude lower than the values for PMMA assisted transfer. In addition, we demonstrated that top-gated transistor devices from our mechanical, delamination transferred graphene exhibited superior transistor behavior to PMMA-assisted wet transfer graphene. The adhesion energy, strength and range of the interactions were quantitatively determined by nonlinear fracture analyses, and suggest that the roughness of the interface between graphene and copper plays an important role with implications for improvements in manufacturing processes.Here we present a very fast, selective mechanical approach for transferring graphene with low levels of copper contamination from seed wafers on which it was grown to target wafers for very large scale integration (VLSI) electronics. We found that graphene/copper or copper/silicon oxide delamination paths could be selected by slow and faster separation rates, respectively. Thus graphene can be transferred to a target wafer, either exposed or protected by the seed copper layer, which can later be removed by etching

  5. The silicon tracker/converter for the gamma-ray large area space telescope

    International Nuclear Information System (INIS)

    The Silicon Tracker/Converter of the Gamma-ray Large Area Space Telescope (GLAST) will have an active area of 80 m2, representing one of the largest planned applications of the silicon-strip detector technology. The large number of channels (1.3 million) to read out, together with the requirement that the tracker provide the trigger to the data acquisition, force the readout electronics to be of very low noise. Furthermore, to fit into the power constraints of the satellite environment, the electronics must have an ultra-low power consumption. To fulfill these requirements, plus others imposed by the space environment, such as redundancy, a mixed mode CMOS front-end readout chip and a digital readout controller chip have been designed and prototyped. In this article, we present the status of the readout electronics and the results from a test-beam study with a small GLAST tracker prototype. (author)

  6. A liquid-helium cooled large-area silicon PIN photodiode X-ray detector

    International Nuclear Information System (INIS)

    An X-ray detector using a liquid-helium cooled large-area silicon PIN photodiode has been developed along with a tailor-made charge sensitive preamplifier whose first-stage JFET has been cooled. The operating temperature of the JFET has been varied separately and optimized. The X- and γ-ray energy spectra for an 241Am source have been measured with the photodiode operated at 13 K. An energy resolution of 1.60 keV (FWHM) has been obtained for 60-keV γ rays and 1.30 keV (FWHM) for the pulser. The energy threshold could be set as low as 3 keV. It has been shown that a silicon PIN photodiode serves as a low-cost excellent X-ray detector which covers a large area at 13 K. (orig.)

  7. Large area silicon drift detectors for x-rays -- New results

    International Nuclear Information System (INIS)

    Large area silicon drift detectors, consisting of 8 mm and 12 mm diameter hexagons, were fabricated on 0.35 mm thick high resistivity n-type silicon. An external FET and a low-noise charge sensitive preamplifier were used for testing the prototype detectors. The detector performance was measured in the range 75 to 25 C using Peltier cooling, and from 0.125 to 6 micros amplifier shaping time. Measured energy resolutions were 159 eV FWHM and 263 eV FWHM for the 0.5 cm2 and 1 cm2 detectors, respectively (at 5.9 keV, -75 C, 6 micros shaping time). The uniformity of the detector response over the entire active area (measured using 560 nm light) was < 0.5%

  8. Application of large area silicon-silicon-plastic detectors for heavy-ion detection

    International Nuclear Information System (INIS)

    To study binary and multibody breakup reactions at intermediate energies (20-100 MeV/u), a 48 element multiplicity array has been designed for reverse kinematic reactions. In reverse kinematics the reaction products are emitted at about beam energy and are focused into a forward cone in the laboratory frame. Each telescope is composed of a 300μm Si, a 5mm Si(Li) and a 7.6cm plastic detector. The geometry of the array is a 7 x 7 wall placed in front of the beam, omitting the center position, which can arc in one dimension. To detect multibody events in the array with good efficiency, the telescopes are designed for close packing and with a 64% active area. These three stage telescopes will be able to detect particles with energies from 1-150 MeV/u, and identify fragments with Z = 2-60 and E/A = 10-100 MeV/u using the ΔE-E technique

  9. Simulation-Based Optimization of Cure Cycle of Large Area Compression Molding for LED Silicone Lens

    OpenAIRE

    Min-Jae Song; Kwon-Hee Kim; Seok-Kwan Hong; Jeong-Won Lee; Jeong-Yeon Park; Gil-Sang Yoon; Heung-Kyu Kim

    2015-01-01

    Three-dimensional heat transfer-curing simulation was performed for the curing process by introducing a large area compression molding for simultaneous forming and mass production for the lens and encapsulants in the LED molding process. A dynamic cure kinetics model for the silicone resin was adopted and cure model and analysis result were validated and compared through a temperature measurement experiment for cylinder geometry with cure model. The temperature deviation between each lens cav...

  10. Rippled area formed by surface plasmon polaritons upon femtosecond laser double-pulse irradiation of silicon.

    Science.gov (United States)

    Derrien, Thibault J-Y; Krüger, Jörg; Itina, Tatiana E; Höhm, Sandra; Rosenfeld, Arkadi; Bonse, Jörn

    2013-12-01

    The formation of near-wavelength laser-induced periodic surface structures (LIPSS) on silicon upon irradiation with sequences of Ti:sapphire femtosecond laser pulse pairs (pulse duration 150 fs, central wavelength 800 nm) is studied theoretically. For this purpose, the nonlinear generation of conduction band electrons in silicon and their relaxation is numerically calculated using a two-temperature model approach including intrapulse changes of optical properties, transport, diffusion and recombination effects. Following the idea that surface plasmon polaritons (SPP) can be excited when the material turns from semiconducting to metallic state, the "SPP active area" is calculated as function of fluence and double-pulse delay up to several picoseconds and compared to the experimentally observed rippled surface areas. Evidence is presented that multi-photon absorption explains the large increase of the rippled area for temporally overlapping pulses. For longer double-pulse delays, relevant relaxation processes are identified. The results demonstrate that femtosecond LIPSS on silicon are caused by the excitation of SPP and can be controlled by temporal pulse shaping. PMID:24514516

  11. Satellite-derived surface type and melt area of the Greenland ice sheet using MODIS data from 2000 to 2005

    Science.gov (United States)

    Fausto, Robert S.; Mayer, Christoph; Ahlstrøm, Andreas P.

    2007-10-01

    A new surface classification algorithm for monitoring snow and ice masses based on data from the moderate-resolution imaging spectroradiometer (MODIS) is presented. The algorithm is applied to the Greenland ice sheet for the period 2000-05 and exploits the spectral variability of ice and snow reflectance to determine the surface classes dry snow, wet snow and glacier ice. The result is a monthly glacier surface type (GST) product on a 1 km resolution grid. The GST product is based on a grouped criteria technique with spectral thresholds and normalized indices for the classification on a pixel-by-pixel basis. The GST shows the changing surface classes, revealing the impact of climate variations on the Greenland ice sheet over time. The area of wet snow and glacier ice is combined into the glacier melt area (GMA) product. The GMA is analyzed in relation to the different surface classes in the GST product. The results are validated with data from weather stations and similar types of satellite-derived products. The validation shows that the automated algorithm successfully distinguishes between the different surface types, implying that the product is a promising indicator of climate change impact on the Greenland ice sheet.

  12. The use of silicone occlusive sheeting (Sil-K) and silicone occlusive gel (epiderm) in the prevention of hypertrophic scar formation

    NARCIS (Netherlands)

    Niessen, FB; Spauwen, PHM; Robinson, PH; Fidler, [No Value; Kon, M

    1998-01-01

    The development of hypertrophic scars and keloids is an unsolved problem in the process of found healing. For this reason, a successful treatment to prevent excessive scar formation still has not been found. Over the last decade, however, a promising new treatment has been introduced. Silicone mater

  13. Microcrystalline silicon deposited at high rate on large areas from pure silane with efficient gas utilization

    Energy Technology Data Exchange (ETDEWEB)

    Strahm, B.; Howling, A.A.; Sansonnens, L.; Hollenstein, C. [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Kroll, U.; Meier, J.; Ellert, Ch. [Oerlikon Solar-Lab, Rue du Puits-Godet 12a, CH-2000 Neuchatel (Switzerland); Feitknecht, L.; Ballif, C. [Institut de Microtechnique, Universite de Neuchatel, Rue A.-L. Breguet 2, CH-2000 Neuchatel (Switzerland)

    2007-03-23

    Microcrystalline silicon thin film deposited by RF-PECVD and integrated in a tandem structure is a promising material for low cost photovoltaic solar cells compared to solar cells based on crystalline silicon. However, in order to allow a cost-effective mass production of solar cells based on this material, deposition processes should fulfill several conditions such as high deposition rate, good uniformity over large area and efficient gas utilization. In this work, it is shown that the atomic hydrogen density can be high enough to form microcrystalline thin films even from a pure silane RF discharge and that the pure silane regime is more efficient in terms of gas utilization. In situ Fourier transform infrared absorption and ex situ Raman spectroscopy measurements have been used to determine the fraction of dissociated silane in the discharge and the crystallinity of the deposited layers. Results have shown that microcrystalline silicon can be deposited uniformly on a large area substrate with a deposition rate of more than 10A with a low powder formation and an input power density of 0.28Wcm{sup -2} from a pure silane discharge. (author)

  14. Large-area 2D periodic crystalline silicon nanodome arrays on nanoimprinted glass exhibiting photonic band structure effects

    International Nuclear Information System (INIS)

    Two-dimensional silicon nanodome arrays are prepared on large areas up to 50 cm2 exhibiting photonic band structure effects in the near-infrared and visible wavelength region by downscaling a recently developed fabrication method based on nanoimprint-patterned glass, high-rate electron-beam evaporation of silicon, self-organized solid phase crystallization and wet-chemical etching. The silicon nanodomes, arranged in square lattice geometry with 300 nm lattice constant, are optically characterized by angular resolved reflection measurements, allowing the partial determination of the photonic band structure. This experimentally determined band structure agrees well with the outcome of three-dimensional optical finite-element simulations. A 16% photonic bandgap is predicted for an optimized geometry of the silicon nanodome arrays. By variation of the duration of the selective etching step, the geometry as well as the optical properties of the periodic silicon nanodome arrays can be controlled systematically. (paper)

  15. Large-Area Synthesis and Microstructural Investigations of Silicon Nano wires and Core-Shell Structures

    International Nuclear Information System (INIS)

    Large-area randomly-oriented silicon nano wires (SiNWs) were synthesized using Au-coated p-type Si(100) substrate via the solid-liquid-solid (SLS) process [1] under different growth conditions. Microstructural studies on the NWs produced show that straight crystalline nano wires of large aspect ratios were generally obtained at a growth temperature of 1000 degree Celsius along with some worm-like amorphous structures. Figure shows the SEM image of a NW sample. Typical high angle X-ray diffractogram in Figure reveals that the NWs are, in general, crystalline. (author)

  16. Performance of the UA6 large-area silicon drift chamber prototype

    International Nuclear Information System (INIS)

    This report presents results on the performance of a large-area silicon drift detector (∝4x4 cm2), which has been designed for use as a high-resolution tracking device in the experiment UA6 at the CERN p-anti p collider. We give here the basic characteristics of the design, and report the first experimental results. The influence, on the detector's performance, of the adopted design criteria and of the quality of the semiconductors has been experimentally determined and is discussed. Results of the first drift-time calibration using an on-board device for charge injection are also given. (orig.)

  17. Characterization of large area, thick, and segmented silicon detectors for neutron β-decay experiments

    International Nuclear Information System (INIS)

    The “Nab” and “UCNB” collaborations have proposed to measure the correlation parameters in neutron β-decay at Oak Ridge and Los Alamos National Laboratory, using a novel detector design. Two large area, thick, hexagonal-segmented silicon detectors containing 127 pixels per detector will be used to detect the proton and electron from neutron decay. Both silicon detectors are connected by magnetic field lines of a few Tesla field strength, and set on an electrostatic potential, such that protons can be accelerated up to 30 keV in order to be detected. Characteristics of the detector response to low energy conversion electrons and protons from 15 keV to 35 keV, including the evaluation of the dead layer thickness and other contributions to the pulse height defect for proton detection are presented for Si detectors of 0.5 mm and 1 mm of thickness. -- Highlights: • We characterized large area (108 cm2), thick (0.5, 1 mm), and 127-segmented Si detectors. • We detected low energy protons from 15 to 35 keV with these large area Si detectors. • The recombination defect is insignificant at Ep<35keV, for appropriate bias voltages. • Our computed nuclear pulse height defect agrees with available experimental data. • Our detector dead layer is ≲110nm, as probed by low energy protons

  18. Structural Biology Fact Sheet

    Science.gov (United States)

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area What is structural biology? Structural biology is a field of science focused ...

  19. Floating Silicon Method

    Energy Technology Data Exchange (ETDEWEB)

    Kellerman, Peter

    2013-12-21

    The Floating Silicon Method (FSM) project at Applied Materials (formerly Varian Semiconductor Equipment Associates), has been funded, in part, by the DOE under a “Photovoltaic Supply Chain and Cross Cutting Technologies” grant (number DE-EE0000595) for the past four years. The original intent of the project was to develop the FSM process from concept to a commercially viable tool. This new manufacturing equipment would support the photovoltaic industry in following ways: eliminate kerf losses and the consumable costs associated with wafer sawing, allow optimal photovoltaic efficiency by producing high-quality silicon sheets, reduce the cost of assembling photovoltaic modules by creating large-area silicon cells which are free of micro-cracks, and would be a drop-in replacement in existing high efficiency cell production process thereby allowing rapid fan-out into the industry.

  20. Fabrication of large area silicon solar cells by rapid thermal processing

    Science.gov (United States)

    Sivoththaman, S.; Laureys, W.; Nijs, J.; Mertens, R.

    1995-10-01

    Large area n+pp+ solar cells have been fabricated on 10 cm×10 cm pseudo-quasi-square CZ silicon wafers (1 Ω cm, p-type) predominantly used by the photovoltaic (PV) industry. All the high-temperature steps have been performed by rapid thermal processing (RTP). Emitter formation, back surface field (BSF) formation, and surface oxidation have been performed in just two RTP steps each lasting 50 s. Solar cells of 15% efficiency have been fabricated this way, demonstrating the applicability of this low thermal budget technology to large area, modulable size, industrial quality Si wafers. Furthermore, the rapid thermal oxidation (RTO) is shown to result in good quality thin oxides with Si/SiO2 interface trap densities (Dit)<1011 cm-3 eV-1 near-midgap.

  1. Photon counting pixel and array in amorphous silicon technology for large area digital medical imaging applications

    Science.gov (United States)

    Yazdandoost, Mohammad Y.; Shin, Kyung W.; Safavian, Nader; Taghibakhsh, Farhad; Karim, Karim S.

    2010-04-01

    A single photon counting Voltage Controlled Oscillator (VCO) based pixel architecture in amorphous silicon (a-Si) technology is reported for large area digital medical imaging. The VCO converts X-ray generated input charge into an output oscillating frequency signal. Experimental results for an in-house fabricated VCO circuit in a-Si technology are presented and external readout circuits to extract the image information from the VCO's frequency output are discussed. These readout circuits can be optimized to reduce the fixed pattern noise and fringing effects in an imaging array containing many such VCO pixels. Noise estimations, stability simulations and measurements for the fabricated VCO are presented. The reported architecture is particularly promising for large area photon counting applications (e.g. low dose fluoroscopy, dental computed tomography (CT)) due to its very low input referred electronic noise, high sensitivity and ease of fabrication in low cost a-Si technology.

  2. Laboratory and test beam results from a large-area silicon drift detector

    International Nuclear Information System (INIS)

    A very large-area (6.75x8 cm2) silicon drift detector with integrated high-voltage divider has been designed, produced and fully characterised in the laboratory by means of ad hoc designed MOS injection electrodes. The detector is of the 'butterfly' type, the sensitive area being subdivided into two regions with a maximum drift length of 3.3 cm. The device was also tested in a pion beam (at the CERN PS) tagged by means of a microstrip detector telescope. Bipolar VLSI front-end cells featuring a noise of 250 e- rms at 0 pF with a slope of 40 e-/pF have been used to read out the signals. The detector showed an excellent stability and featured the expected characteristics. Some preliminary results will be presented.

  3. Silicon oxide nanowires: facile and controlled large area fabrication of vertically oriented silicon oxide nanowires for photoluminescence and sensor applications.

    Science.gov (United States)

    Alabi, Taiwo R; Yuan, Dajun; Bucknall, David; Das, Suman

    2013-09-25

    We describe a technique for the fabrication of dense and patterned arrays of aligned silicon oxide nanowires for applications in surface modification, optoelectronic, and electromechanical based devices. Conventional techniques for the fabrication of silicon oxide nanowires based on the vapor-liquid-solid (VLS) chemical vapor deposition (CVD) processes involve the use of high temperatures and catalysts. We demonstrate a technique that extends the use of a plasma thermal reactive ion etching for the fabrication of aligned silicon oxide nanowires with aspect ratios extending up to 20 and lengths exceeding 1 μm. The process incorporates phase separated PS-b-P4VP block copolymer loaded with an iron salt. The iron salt preferentially segregates into the P4VP layer and during an O2 etch is not removed but forms a hexagonally packed array on the silicon oxide substrate. Further etching with CHF3/O2 gas mixture over time can generate nanodots, to nanopillars, and then nanowires of silicon oxide. The photoluminescence property of the as-fabricated nanowire arrays as well as the parasitic ferromagnetic effect from the iron oxide-tipped section of the wires resulting in coalescence under an scanning electron microscope (SEM) are demonstrated. This technique is simpler compared to existing VLS fabrication approaches and can be used for the direct fabrication of patterned arrays of nanowires when a laser interference ablation step is incorporated into the fabrication procedure. PMID:23915216

  4. Geological interpretation of aeromagnetics and aeroradiometrics data of Carajas area - sheet SB-22-Z-A-III

    International Nuclear Information System (INIS)

    The upward continued map of sheet SB.22-Z-A-III in the Carajas Mineral Province shows the magnetic anomalies associated to the Leste Ridge, Carajas fault and Rabo Ridge to be more complex than apparent from the total magnetic field map. It also shows that the Carajas granite truncates metasediments of the Salobo Sequence northeast of the Carajas fault. First vertical derivative processing with reduction to the pole has been effective in the definition of the magnetic structures associated with the upper crustal sequences of the basement complex of the Carajas area and has made it possible the definition of the magnetic lineations associated with the tectonic structure of the area. The apparent magnetic susceptibility map has further reinforced the interpretted zones and the structures that were defined from the first vertical derivative map. The radiometric data were important in the definition of the granite borders and in the separation of the Salobo and Grao-Para units. This work suggest improvements to the geologic knowledge of this part of the Carajas area. Based on this geophysical interpretation and correlation with known mineralizations, prioirty areas have been identified as having high potencial for economic mineralization. Recommendations are made for more detailed geophysical follow-up studies in these areas. (author)

  5. Ice stream behaviour and deglaciation of the Scandinavian Ice Sheet in the Kuittijärvi area, Russian Karelia

    Directory of Open Access Journals (Sweden)

    Juha-Pekka Lunkka

    2008-01-01

    Full Text Available Glacial landforms of the Lake Kuittijärvi area, Russian Karelia, which covers an area of more than 7000 km^2, were studied in detail using aerial photography and satellite imagery methods and on-site field observations. This was done to reconstruct a detailed historyof Scandinavian ice sheet behaviour in the Lake Kuittijärvi area. The results indicate that the Lake Tuoppajärvi sub-ice stream (TIS that formed the northern part of the Kuusamo-White Sea ice stream and the Lake Kuittijärvi sub-ice stream (KIS, which was part of theNorthern Karelian ice stream, operated in the area during the last deglaciation. Subglacially formed lineation patterns associated with other indicative landforms such as end moraines and esker ridges indicate a clear age relationship between the ice streams’ activity and that the KIS was active after the linear landforms were created by the TIS. It is estimated that deglaciation of the TIS from the Kalevala end moraine to the Lake Pääjärvi end moraine took place between ca. 11 300 – 10 900 calendar years ago. It seems that the terminus of the KIS marker by the Kalevala end moraine was also formed around 11 300 calendar years ago but the KIS remained active longer than the TIS. Both of these sub-ice streams terminated into a glacial lake that was part of a larger White Sea Basin ice lake.

  6. Colorado River Wildlife Management Area (Green River Easements) [Land Status Map: Sheet 1 of 2

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This map was produced by the Division of Realty to depict landownership at Colorado River Wildlife Management Area. It was generated from rectified aerial...

  7. Investigations on debris sheets for the analysis of slope instability conditions in the Machu Picchu area

    OpenAIRE

    Casagli N.; Fanti R.; Morelli S.; Nocentini M.; Vannocci P.

    2006-01-01

    Since 1997 the Machu Picchu area has been in the spotlight for its slope instability, when Carreno & Bonnard described the general geological and geomorphological condition, and the further studies of Sassa et alii (2001, 2002) contributed to define the interpretation of the structures, as the result of the existence of a main deep slow slide involving the archaeological area. However, the attention of these studies focused on the condition of the entire slope, with a lesser co...

  8. Characterization of an amorphous silicon flat panel for controlling the positioning accuracy of sheet; Caracterizacion de un panel plano de silicio amorfo para control de la exactitud en el posicionamiento de laminas

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, J.; Gonzalez, V.; Gimeno, J.; Dolores, V. de los; Pastor, V.; Crispin, V.; Guardino, C.

    2011-07-01

    It has established a method for measuring the position of the blades in a multi leaf collimator (MLC) used to measure dose portal imaging device (EPID) of amorphous silicon, and verified its accuracy using radiochromic films and measures water with diode Cuba, techniques perfectly well validated in our institution. This dose profiles are studied for each sheet and determine their position at the point which has 50% of the dose in the open field.

  9. Edgeless silicon sensors for Medipix-based large-area X-ray imaging detectors

    International Nuclear Information System (INIS)

    Some X-ray imaging applications demand sensitive areas exceeding the active area of a single sensor. This requires a seamless tessellation of multiple detector modules with edgeless sensors. Our research is aimed at minimising the insensitive periphery that isolates the active area from the edge. Reduction of the edge-defect induced charge injection, caused by the deleterious effects of dicing, is an important step. We report on the electrical characterisation of 300 μm thick edgeless silicon p+-ν-n+ diodes, diced using deep reactive ion etching. Sensors with both n-type and p-type stop rings were fabricated in various edge topologies. Leakage currents in the active area are compared with those of sensors with a conventional design. As expected, we observe an inverse correlation between leakage-current density and both the edge distance and stop-ring width. From this correlation we determine a minimum acceptable edge distance of 50 μm. We also conclude that structures with a p-type stop ring show lower leakage currents and higher breakdown voltages than the ones with an n-type stop ring.

  10. Development of large area silicon semiconductor detectors for use in the current mode

    International Nuclear Information System (INIS)

    Large area silicon semiconductor detectors for use in the current mode, with their dimensions of φ40, φ50 and φ60 mm, their depletion thickness of 200-300 μm, have been developed. Their performance measurements have been made, which indicate that the developed detectors can satisfactorily meet the needs in expectation. Compared with the detectors commercially available on the market, authors' large PIN detectors can serve both as reliable and efficient high-resolution devices for nuclear counting experiments, as well as monitors of high-intensity radiation fields in the current mode under a bias of 100-1000 V, while the detectors commercially available are only for the counting use

  11. Doping Silicon Wafers with Boron by Use of Silicon Paste

    Institute of Scientific and Technical Information of China (English)

    Yu Gao; Shu Zhou; Yunfan Zhang; Chen Dong; Xiaodong Pi; Deren Yang

    2013-01-01

    In this work we introduce recently developed silicon-paste-enabled p-type doping for silicon.Boron-doped silicon nanoparticles are synthesized by a plasma approach.They are then dispersed in solvents to form silicon paste.Silicon paste is screen-printed at the surface of silicon wafers.By annealing,boron atoms in silicon paste diffuse into silicon wafers.Chemical analysis is employed to obtain the concentrations of boron in silicon nanoparticles.The successful doping of silicon wafers with boron is evidenced by secondary ion mass spectroscopy (SIMS) and sheet resistance measurements.

  12. Ultrathin Silicon Sheet in the Management of Unilateral Post-traumatic Temporo-Mandibuar Joint Ankylosis in Children: A Good Alternative to Conventional Techniques.

    Science.gov (United States)

    Aggarwal, Sushil Kumar; Ankur, Bhatnagar; Jain, R K

    2015-09-01

    We have described a new technique of using ultra-thin silicon sheet (0.2 mm) between two transected bony ends for temporo-mandibular joint (TMJ) ankylosis in children with advantages of short operative time, minimal foreign material insertion and faster recovery time post-operatively which makes our technique a good alternative to conventional techniques. Our study is a non-randomized prospective study conducted on 10 children aged between 4 and 15 years who presented to our tertiary care institute with severe trismus after traumatic injury and were willing to undergo this new technique. The main outcome measure taken into consideration was difference between pre-operative, intra-operative (on table) and post-operative mouth opening (minimum 2 years follow-up). The pre-operative mouth opening in our cases varied from 1 to 5 mm. The intra-operative mouth opening achieved ranged from 2.8 to 3.2 cm. The mouth opening was about more than 2.7 cm in all our cases at 2 years of follow-up. Our technique is a good alternative to conventional techniques used for TMJ ankylosis in children but few more randomized controlled trials are required to assess its effectiveness in comparison to conventional techniques and for universal adoption of this technique. PMID:26405658

  13. Data sheet based countermeasure evaluation for radioactively contaminated Nordic food-producing areas

    International Nuclear Information System (INIS)

    A Nordic expert group has identified and critically evaluated the countermeasures that may potentially be implemented in connection with major nuclear accident situations contaminating Nordic food-producing areas. This paper demonstrates how the derived technical information can be applied by decision-makers to identify practicable and cost-effective means for mitigation of the impact of contamination. (au)

  14. A large-area monolithic array of silicon drift detectors for medical imaging

    International Nuclear Information System (INIS)

    Monolithic arrays of silicon drift detectors (SDDs) have been recently proposed to be used with scintillators for high-position-resolution γ-ray imaging applications. Thanks to the low electronics noise due to the small value of the output capacitance, the SDD offers better noise performances with respect to conventional photodiodes of the same geometry. Small monolithic arrays of SDDs have been used as photodetector of the scintillation light in a first prototype of Anger Camera for γ-ray imaging characterized by an intrinsic resolution better than 0.3 mm. In this work, we present a new large-area monolithic array of SDDs. It consists of a single chip composed of 77 single hexagonal units, each one with an active area of 8.7 mm2, for a total active area of the device of 6.7 cm2. It represents the largest monolithic array of SDDs with on-chip JFETs produced up to now for X-ray and γ-ray detection. The results achieved in the experimental characterization of a first prototype of the detector array are presented, both with X and visible photons. The energy resolution measured at 6 keV with the single unit of the array is of 142 eV at -10 oC, while a QE>90% was measured at λ=550 nm

  15. Simulation-Based Optimization of Cure Cycle of Large Area Compression Molding for LED Silicone Lens

    Directory of Open Access Journals (Sweden)

    Min-Jae Song

    2015-01-01

    Full Text Available Three-dimensional heat transfer-curing simulation was performed for the curing process by introducing a large area compression molding for simultaneous forming and mass production for the lens and encapsulants in the LED molding process. A dynamic cure kinetics model for the silicone resin was adopted and cure model and analysis result were validated and compared through a temperature measurement experiment for cylinder geometry with cure model. The temperature deviation between each lens cavity could be reduced by implementing a simulation model on the large area compression mold and by optimizing the location of heat source. A two-step cure cycle was constructed to reduce excessive reaction peak at the initial stage and cycle time. An optimum cure cycle that could reduce cycle time by more than 29% compared to a one-step cure cycle by adjusting dwell temperature, heating rate, and dwell time was proposed. It was thus confirmed that an optimization of large area LED lens molding process was possible by using the present experiment and the finite element method.

  16. Structure and formation mechanism of rolled-in oxide areas on aluminum lithographic printing sheets

    International Nuclear Information System (INIS)

    The subsurface area introduced during rolling on the 1100 aluminum alloy series alters its surface properties, which makes it more susceptible to corrosion. A combination of different transmission electron microscopy techniques is employed to observe the orientation of small grain structures and the distribution elements in the subsurface layer. This approach provided valuable insight into the formation mechanism of the layer and the phenomena taking place during rolling.

  17. Coherent Bremsstrahlung effect observed during STEM analysis of dopant distribution in silicon devices using large area silicon drift EDX detectors and high brightness electron source

    International Nuclear Information System (INIS)

    In this paper, during dopant analysis of silicon devices, we have observed a phenomenon generally neglected in EDX analysis: the coherent Bremsstrahlung (CB). We discussed the reason why and came to the conclusion that the analytical TEM used for these experiments presents a configuration and performances, which makes this equipment very sensitive to the CB effect. This is due to large collection solid angle and high counting rate of the four silicon drift EDX detectors (SDD), a high brightness electron source providing large probe current and moreover a geometry favorable to on axis crystal observations. We analyzed silicon devices containing Si [110] and Si [100] crystal areas at different energies (80–120–200 keV). We also observed relaxed SiGe (27 and 40 at% of Ge). The CB effect, whose intensity is maximum near zone axis beam alignment, manifests as characteristic broad peaks present in the X-ray spectrum background. The peak energies are predicted by a simple formula deduced for the CB models found in the literature and that we present simply. We evaluate also the CB peak intensities and discuss the importance of this effect on the detection and quantification traces of impurities. The CB peaks also give information on the analyzed crystal structure (measurement of the periodicity along the zone axis) and allow, in every particular experiment or system, to determine the median take off angle of the EDX detectors. -- Highlights: ► STEM EDX dopant distribution analysis (As and P) in Si devices is carried out. ► High brightness electron source and four EDX Silicon Drift detectors are used. ► The obtained signal dynamics (four decades) allows detection down to 0.01 at%. ► During silicon axis analysis coherent Bremmsstrahlung is observed. ► This effect is studied at different energies and Si crystal orientations.

  18. General fact sheet - Limiting conditions and reliability, ventilation, room size, body surface area. Updated version for ConsExpo 4

    OpenAIRE

    Bremmer HJ; Prud'homme de Lodder LCH; Engelen, Jacqueline G M van

    2006-01-01

    In this fact sheet general information is presented necessary to calculate exposure of consumers to compounds in consumer products. Calculations are carried out with the computer program ConsExpo (Consumer Exposure). To calculate the exposure information is gathered about groups containing similar products like: paint, pest control products, cosmetics and cleaning products. The information is described in a fact sheet. This fact sheet covers information about the way human exposure is calcula...

  19. Nanopillars: Large Area Fabrication of Leaning Silicon Nanopillars for Surface Enhanced Raman Spectroscopy (Adv. Mater. 10/2012)

    DEFF Research Database (Denmark)

    Schmidt, Michael Stenbæk; Hübner, Jörg; Boisen, Anja

    2012-01-01

    M. S. Schmidt et al. describe on page OP11 a simple, two-step fabrication process to as-semble flexible, freestanding nanopillars into large-area substrates. These substrates can be made using readily available silicon-processing equipment and are suitable for SERS, having a large, uniform Raman...

  20. Sponge fossils of Middle Dnieper River Upper Eocenian deposits (geological survey sheet area «Kobelyaki»

    Directory of Open Access Journals (Sweden)

    Stephanska T.A.

    2015-09-01

    Full Text Available For the first time sponge spicules of the Paleogene on the geological survey sheet area «Kobelyaki» were studied. Using artificial classification M.M. Ivanik (2003 45 taxa spicules were found in rocks. Morphological types spicules were defined. In the complexes following megascleres of «soft» Demospongiae are dominant: pro-, plagio-, ortho-, dicho-, anatriaenes, caltrops, smooth and echinated oxeas, subtylostyls, strongyls, ophioxeas. Diaenes, monenes, caltrops with reduced beam (olimtriaenes, are less common. Microscleres are numerous: sterrasters, sphaerasters, oxysphaerasters, oxyasters. Fragments of dyctional gratings without lychnisks and free spicules of hexactinellid sponges are frequent (pentactines, hexactines. Megascleres of lithistid sponges (phyllotriaenes, tetracrepid desmas, triders, megaclones, dicranoclones are relatively few. The palaeocenosis structure that existed in the Obukhov Sea on this area, it was found by morphological analysis of sponges spicules. In the Obukhov time following sponges dominated here: «soft» sponges with unrelated skeleton that belonged to the class Demospongiae (orders Poecilosclerida, Astrophorida and families Geodiidae, Pachastrellidae, Ancorinidae, Calthropellidae, Tethyidae, Crellidae and hexactinellids of class Hexactinellida (orders Hexactinosida and Lyssacinosida. А few sponges spicules (belonged to the subclass Lithistida, families Corallistidae, Theonellidae, Phymaraphiniidae, Chenendoporidae, Pleromidae and lack lithistid skeletal gratings fragments in the studied complexes may indicate a desmas transfer from neighboring, a shallow Obukhov stations, which were confined to the nearby slope of the Ukrainian Shield. On the base of sponge spicules studying the Late Eocene (Obukhov age of surrounding deposits is proved. spongе spicula, Upper Eocene, Obuchovian Suite, Middle Dnieper region.

  1. Surface States and Effective Surface Area on Photoluminescent P-Type Porous Silicon

    Science.gov (United States)

    Weisz, S. Z.; Porras, A. Ramirez; Resto, O.; Goldstein, Y.; Many, A.; Savir, E.

    1997-01-01

    The present study is motivated by the possibility of utilizing porous silicon for spectral sensors. Pulse measurements on the porous-Si/electrolyte system are employed to determine the surface effective area and the surface-state density at various stages of the anodization process used to produce the porous material. Such measurements were combined with studies of the photoluminescence spectra. These spectra were found to shift progressively to the blue as a function of anodization time. The luminescence intensity increases initially with anodization time, reaches a maximum and then decreases with further anodization. The surface state density, on the other hand, increases with anodization time from an initial value of about 2 x 10(exp 12)/sq cm surface to about 1013 sq cm for the anodized surface. This value is attained already after -2 min anodization and upon further anodization remains fairly constant. In parallel, the effective surface area increases by a factor of 10-30. This behavior is markedly different from the one observed previously for n-type porous Si.

  2. Large-Area, UV-Optimized, Back-Illuminated Silicon Photomultiplier Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Existing photocathode-based technologies for visible and UV instruments lack sensitivity, are bulky, and have limited reliability. Solid-state silicon...

  3. Development of a Thick-film Silicon Ribbon Growth Technique for Application to Large-area Solar Cells and Arrays

    Science.gov (United States)

    Berman, P. A.

    1973-01-01

    A new technique is described for growth of large-area silicon ribbons. This technique is an edge-defined, film-fed growth process by which single crystals can be grown having a shape controlled by the outside dimensions of a shaping die, growth taking place from an extremely thin film of liquid fed by capillary action from a crucible below. The material from which the die is fabricated is very critical to the process. The die must be wet by the silicon, but adverse impurities must not be introduced into the silicon, and the die must not become degraded by the molten silicon. A breakthrough in die fabrication that has allowed the growth of silicon ribbons having dimensions of 1 cm by 30 cm with a thickness of 0.7 mm is described. The implications of this significant advancement with respect to development of photovoltaic solar arrays for wide-scale terrestrial solar-to-electric energy conversion systems are discussed.

  4. Evolution of recrystallization texture in high silicon steel shin sheets during annealing%高硅钢薄板退火过程中的织构演变

    Institute of Scientific and Technical Information of China (English)

    柳金龙; 沙玉辉; 张芳; 姚勇创; 李继超; 左良

    2011-01-01

    High silicon steel thin sheets with thickness of 0.3mm were successfully produced by conventional rolling and annealing methods.Recrystallization texture was investigated by means of X-ray diffraction.It is found that recrystallization texture is mainly composed of γ fiber(〈111〉∥ND)with peak at {111}〈112〉 and {001} fiber with peak at {001}〈210〉 after annealing at 700℃,while strong {001}〈210〉 component dominates recrystallization texture after annealing above 900℃.It is during grain growth that {001}〈210〉 is significantly enhanced and finally develops to the main texture component.%采用传统的轧制和退火工艺制备了0.30mm厚的6.5%(质量分数)Si高硅电工钢薄板,采用X射线衍射技术对退火过程中的再结晶织构进行了研究。冷轧高硅钢薄板700℃退火形成以{111}〈112〉为峰值的γ织构(〈111〉∥ND)和以{001}〈210〉为峰值的{001}织构;而900℃以上温度退火则形成强{001}〈210〉织构。进一步的研究表明是在晶粒长大过程中{001}〈210〉发展成为主要再结晶织构组分。

  5. Closure Report for Corrective Action Unit 271: Areas 25, 26, and 27 Septic Systems, Nevada Test Site, Nevada with Errata Sheet, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Mark Krauss

    2004-08-01

    The purpose of this CR is to document that closure activities have met the approved closure standards detailed in the NDEP-approved CAP for CAU 271. The purpose of the Errata Sheet is as follows: In Appendix G, Use Restriction (UR) Documentation, the UR form and drawing of the UR area do not reflect the correct coordinates. Since the original UR was put into place, the UR Form has been updated to include additional information that was not on the original form. This Errata Sheet replaces the original UR Form and drawing. In place of the drawing of the UR area, an aerial photograph is included which reflects the UR area and the correct coordinates for the UR area.

  6. Coherent Bremsstrahlung effect observed during STEM analysis of dopant distribution in silicon devices using large area silicon drift EDX detectors and high brightness electron source.

    Science.gov (United States)

    Pantel, R

    2011-11-01

    In this paper, during dopant analysis of silicon devices, we have observed a phenomenon generally neglected in EDX analysis: the coherent Bremsstrahlung (CB). We discussed the reason why and came to the conclusion that the analytical TEM used for these experiments presents a configuration and performances, which makes this equipment very sensitive to the CB effect. This is due to large collection solid angle and high counting rate of the four silicon drift EDX detectors (SDD), a high brightness electron source providing large probe current and moreover a geometry favorable to on axis crystal observations. We analyzed silicon devices containing Si [110] and Si [100] crystal areas at different energies (80-120-200keV). We also observed relaxed SiGe (27 and 40at% of Ge). The CB effect, whose intensity is maximum near zone axis beam alignment, manifests as characteristic broad peaks present in the X-ray spectrum background. The peak energies are predicted by a simple formula deduced for the CB models found in the literature and that we present simply. We evaluate also the CB peak intensities and discuss the importance of this effect on the detection and quantification traces of impurities. The CB peaks also give information on the analyzed crystal structure (measurement of the periodicity along the zone axis) and allow, in every particular experiment or system, to determine the median take off angle of the EDX detectors. PMID:21946001

  7. Controlled synthesis and transfer of large-area WS2 sheets: from single layer to few layers.

    Science.gov (United States)

    Elías, Ana Laura; Perea-López, Néstor; Castro-Beltrán, Andrés; Berkdemir, Ayse; Lv, Ruitao; Feng, Simin; Long, Aaron D; Hayashi, Takuya; Kim, Yoong Ahm; Endo, Morinobu; Gutiérrez, Humberto R; Pradhan, Nihar R; Balicas, Luis; Mallouk, Thomas E; López-Urías, Florentino; Terrones, Humberto; Terrones, Mauricio

    2013-06-25

    The isolation of few-layered transition metal dichalcogenides has mainly been performed by mechanical and chemical exfoliation with very low yields. In this account, a controlled thermal reduction-sulfurization method is used to synthesize large-area (~1 cm(2)) WS2 sheets with thicknesses ranging from monolayers to a few layers. During synthesis, WOx thin films are first deposited on Si/SiO2 substrates, which are then sulfurized (under vacuum) at high temperatures (750-950 °C). An efficient route to transfer the synthesized WS2 films onto different substrates such as quartz and transmission electron microscopy (TEM) grids has been satisfactorily developed using concentrated HF. Samples with different thicknesses have been analyzed by Raman spectroscopy and TEM, and their photoluminescence properties have been evaluated. We demonstrated the presence of single-, bi-, and few-layered WS2 on as-grown samples. It is well known that the electronic structure of these materials is very sensitive to the number of layers, ranging from indirect band gap semiconductor in the bulk phase to direct band gap semiconductor in monolayers. This method has also proved successful in the synthesis of heterogeneous systems of MoS2 and WS2 layers, thus shedding light on the controlled production of heterolayered devices from transition metal chalcogenides. PMID:23647141

  8. Development of [l brace]100[r brace] texture in silicon steel sheets by isothermal austenite[yields]ferrite transformations and its mechanism. Keiso kohan ni okeru toon [gamma][yields][alpha] hentai ni yoru [l brace]100[r brace] shugo soshiki no keisei to sono kiko

    Energy Technology Data Exchange (ETDEWEB)

    Tomida, T. (Sumitomo Metal Industries Ltd., Osaka (Japan). Advanced Technology Research Lab.); Tanaka, T. (Sumitomo Metal Industries Ltd., Osaka (Japan). Iron and Steel Research Lab.)

    1993-12-01

    The texture in silicon steel sheets has been studied during this half of century and the methods for forming the textures suitable as the soft-magnetic materials of [l brace]110[r brace][l angle]001[r angle] as well as [l brace]100[r brace][l angle]001[r angle] have been found. However, few researches has been carried out on the silicon steel using positively the innate properties of the steel such as the transformation between the austenite ([gamma]) and [alpha]-ferrite and the recrystallization in the coexisting area of [alpha]/[gamma] duplex. In this study, the isothermal [alpha][yields][gamma] transformation during the process of vacuum-annealing and decarburizing-annealing of 2% silicon steel containing carbon and Mn and the texture formation accompanied therewith are examined. The conclusions are as follows. The isothermal [alpha][yields][gamma] transformation occurs in the layer just below the surface and the structure of the surface becomes the single phase of [alpha]-ferrite in the vacuum of 10[sup -3]Pa and the temperature is kept constant within the range of [alpha]/[gamma] duplex temperature or [gamma]-phase temperature as from 850 to 1050 centigrade. This surface structure develops to the strong [l brace]100[r brace] texture. 12 refs., 8 figs., 2 tabs.

  9. Measurement of Characteristic Impedance of Silicon Fiber Sheet based readout strips panel for RPC detector in INO

    CERN Document Server

    Singh, M K; Marimuthu, N; Singh, V; Subrahmanyam, V S

    2016-01-01

    The India based Neutrino Observatory (INO) is a mega science project of India, which is going to use near about 30, 000 Resistive Plate Chambers (RPC) as active detector elements for the study of atmospheric neutrino oscillations. Each RPC detector will consist of two orthogonally placed readout strips panel for picking the signals generated in the gas chamber. The area of RPC detector in INO-ICAL (Iron Calorimeter) experiment will be 2m x 2m, therefore the dimension of readout strips panel will also be of 2m x 2m. To get undistorted signals pass through the readout strips panel to frontend electronics, their Characteristic Impedance should be matched with each other. For the matching of Characteristic Impedance we have used the principle of termination. In the present paper we will describe the need and search of new dielectric material for the fabrication of flame resistant, waterproof and flexible readout pickup strips panel. We will also describe the measurement of Characteristic Impedance of plastic hone...

  10. Analysis of defect structure in silicon. Characterization of SEMIX material. Silicon sheet growth development for the large area silicon sheet task of the low-cost solar array project

    Science.gov (United States)

    Natesh, R.; Stringfellow, G. B.; Virkar, A. V.; Dunn, J.; Guyer, T.

    1983-01-01

    Statistically significant quantitative structural imperfection measurements were made on samples from ubiquitous crystalline process (UCP) Ingot 5848 - 13C. Important correlation was obtained between defect densities, cell efficiency, and diffusion length. Grain boundary substructure displayed a strong influence on the conversion efficiency of solar cells from Semix material. Quantitative microscopy measurements gave statistically significant information compared to other microanalytical techniques. A surface preparation technique to obtain proper contrast of structural defects suitable for quantimet quantitative image analyzer (QTM) analysis was perfected and is used routinely. The relationships between hole mobility and grain boundary density was determined. Mobility was measured using the van der Pauw technique, and grain boundary density was measured using quantitative microscopy technique. Mobility was found to decrease with increasing grain boundary density.

  11. Initial steps toward the realization of large area arrays of single photon counting pixels based on polycrystalline silicon TFTs

    Science.gov (United States)

    Liang, Albert K.; Koniczek, Martin; Antonuk, Larry E.; El-Mohri, Youcef; Zhao, Qihua; Jiang, Hao; Street, Robert A.; Lu, Jeng Ping

    2014-03-01

    The thin-film semiconductor processing methods that enabled creation of inexpensive liquid crystal displays based on amorphous silicon transistors for cell phones and televisions, as well as desktop, laptop and mobile computers, also facilitated the development of devices that have become ubiquitous in medical x-ray imaging environments. These devices, called active matrix flat-panel imagers (AMFPIs), measure the integrated signal generated by incident X rays and offer detection areas as large as ~43×43 cm2. In recent years, there has been growing interest in medical x-ray imagers that record information from X ray photons on an individual basis. However, such photon counting devices have generally been based on crystalline silicon, a material not inherently suited to the cost-effective manufacture of monolithic devices of a size comparable to that of AMFPIs. Motivated by these considerations, we have developed an initial set of small area prototype arrays using thin-film processing methods and polycrystalline silicon transistors. These prototypes were developed in the spirit of exploring the possibility of creating large area arrays offering single photon counting capabilities and, to our knowledge, are the first photon counting arrays fabricated using thin film techniques. In this paper, the architecture of the prototype pixels is presented and considerations that influenced the design of the pixel circuits, including amplifier noise, TFT performance variations, and minimum feature size, are discussed.

  12. Removing Defects From Silicon Ribbon

    Science.gov (United States)

    Shimada, K.

    1982-01-01

    Proposal for removing impurities from silicon ribbon and sheet could be developed into an automated production-line process. New technique which combines ion-cluster bombardment, electron-gun heating, and plasma etching, could be key step in fabricating inexpensive solar-cell arrays. Silicon sheets and ribbons treated this way could have enhanced carrier lifetimes necessary for satisfactory solar-cell performance.

  13. Magnetically enhanced triode etching of large area silicon membranes in a molecular bromine plasma

    International Nuclear Information System (INIS)

    The optimization of a process for etching 125 mm silicon membranes formed on 150 mm wafers and bonded to Pyrex rings is discussed. A magnetically enhanced triode etching system was designed to provide an intense, remote plasma surrounding the membrane while, at the same time, suppressing the discharge over the membrane itself. For the optimized molecular bromine process, the silicon etch rate is 40 nm/min and the selectivity relative to SiO2 is 160:1. 14 refs., 6 figs

  14. Selected area laser-crystallized polycrystalline silicon thin films by a pulsed Nd:YAG laser with 355 nm wavelength

    Institute of Scientific and Technical Information of China (English)

    Duan Chunyan; Liu Chao; Ai Bin; Lai Jianjun; Deng Youjun; Shen Hui

    2011-01-01

    Selected area laser-crystallized polycrystalline silicon(p-Si)thin films were prepared by the third harmonics(355 nm wavelength)generated by a solid-state pulsed Nd:YAG laser.Surface morphologies of 400 nm thick films after laser irradiation were analyzed.Raman spectra show that film crystallinity is improved with increase of laser energy.The optimum laser energy density is sensitive to the film thickness.The laser energy density for efficiently crystallizing amorphous silicon films is between 440-634 mJ/cm2 for 300 nm thick films and between 777-993 mJ/cm2 for 400 nm thick films.The optimized laser energy density is 634,975 and 1571 mJ/cm2 for 300,400 and 500 nm thick films,respectively.

  15. Process Simulation and Characterization of Substrate Engineered Silicon Thin Film Transistor for Display Sensors and Large Area Electronics

    International Nuclear Information System (INIS)

    Design, simulation, fabrication and post-process qualification of substrate-engineered Thin Film Transistors (TFTs) are carried out to suggest an alternate manufacturing process step focused on display sensors and large area electronics applications. Damage created by ion implantation of Helium and Silicon ions into single-crystalline n-type silicon substrate provides an alternate route to create an amorphized region responsible for the fabrication of TFT structures with controllable and application-specific output parameters. The post-process qualification of starting material and full-cycle devices using Rutherford Backscattering Spectrometry (RBS) and Proton or Particle induced X-ray Emission (PIXE) techniques also provide an insight to optimize the process protocols as well as their applicability in the manufacturing cycle

  16. Single-crystalline ZnO sheet Source-Gated Transistors

    OpenAIRE

    Dahiya, A. S.; Opoku, C.; Sporea,R.A.; Sarvankumar, B.; G. Poulin-Vittrant; F. Cayrel; Camara, N.; D. Alquier

    2016-01-01

    Due to their fabrication simplicity, fully compatible with low-cost large-area device assembly strategies, source-gated transistors (SGTs) have received significant research attention in the area of high-performance electronics over large area low-cost substrates. While usually based on either amorphous or polycrystalline silicon (α-Si and poly-Si, respectively) thin-film technologies, the present work demonstrate the assembly of SGTs based on single-crystalline ZnO sheet (ZS) with asymmetric...

  17. Light management in large area thin-film silicon solar modules

    Czech Academy of Sciences Publication Activity Database

    Losio, P.A.; Caglar, O.; Cashmore, J.S.; Hötzel, J.E.; Ristau, S.; Holovský, Jakub; Remeš, Zdeněk; Sinicco, I.

    2015-01-01

    Roč. 143, Dec (2015), s. 375-385. ISSN 0927-0248 R&D Projects: GA ČR(CZ) GA14-05053S Institutional support: RVO:68378271 Keywords : micromorph * thin- film silicon solar cells * light management * ZnO Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 5.337, year: 2014

  18. Simple fabrication of air-stable black phosphorus heterostructures with large-area hBN sheets grown by chemical vapor deposition method

    Science.gov (United States)

    Sinha, Sapna; Takabayashi, Yuya; Shinohara, Hisanori; Kitaura, Ryo

    2016-09-01

    We have developed a facile and general method to passivate thin black phosphorus (BP) flakes with large-area high-quality monolayer hexagonal boron nitride (hBN) sheets grown by the chemical vapor deposition (CVD) method. In spite of the one-atom-thick structure, the high-quality CVD-grown monolayer hBN has proven to be useful to prevent the degradation of thin BP flakes exfoliated on substrates. Mechanically exfoliated BP flakes prepared on a Si substrate are covered by the monolayer hBN sheet to preserve (otherwise unstable) atomic layered BP flakes from degradation. The present technique can generally be applied to fabricating BP-based electronic devices with much easiness.

  19. Gamma large area silicon telescope: Applying SI strip detector technology to the detection of gamma rays in space

    Science.gov (United States)

    Atwood, W. B.; Bloom, E. D.; Godfrey, G. L.; Hertz, P. L.; Lin, Ying-Chi; Nolan, P. L.; Snyder, A. E.; Taylor, R. E.; Wood, K. S.; Michelson, P. F.

    1992-12-01

    The recent discoveries and excitement generated by EGRET (Energetic Gamma Ray Experiment Telescope) (presently operating on CGRO (Compton Gamma Ray Observatory)) has prompted an investigation into modern technologies ultimately leading to the next generation space based gamma ray telescope. The goal is to design a detector that would increase the data acquisition rate by almost two orders of magnitude beyond EGRET, while at the same time improving on the angular resolution, the energy measurement of reconstructed gamma rays and the triggering capability of the instrument. The proposed GLAST (Gamma Ray Large Area Silicon Telescope) instrument is based on silicon particle detectors that offer the advantages of no consumables, no gas volume, robust (versus fragile), long lived, and self triggering. The GLAST detector is roughly modeled after EGRET in that a tracking module precedes a calorimeter. The GLAST tracker has planes of cross strip (x, y) 300 micrometer match silicon detectors coupled to a thin radiator to measure the coordinates of converted electron-positron pairs. An angular resolution of 0.1 deg at high energy is possible (the low energy angular resolution 100 MeV would be about 2 deg, limited by multiple scattering). The increased depth of the GLAST calorimeter over EGRET's extends the energy range to about 300 GeV.

  20. Ice-Sheet Dynamics Of Warta Glaciation (SAALE In The Marginal Zone Of Knyszewicze Area, Northeastern Poland

    Directory of Open Access Journals (Sweden)

    Rychel Joanna

    2015-12-01

    Full Text Available The paper presents a research on a marginal zone near Knyszewicze in the southern part of Sokółka Hills (northeastern Poland. Terminal moraine hills are arranged amphitheatrically in a lobal pattern. Dynamics of the Knyszewicze frontal ice-sheet lobe during the Saale Glaciation and successive stages of the marginal zone near the village of Knyszewicze were reconstructed based on sedimentary and geomorphological analysis, using a digital elevation model and morpholineaments. Three main phases of the Knyszewicze glacial-lobe activity were identified including accumulation of glaciofluvial deposits, advances of the ice margin and ice-lobe retreat. Moraine hills developed at a stable ice-lobe terminus, initially as short end-moraine fans with the following sequence of lithofacies Gh⇒SGh⇒Sh or Gm⇒Gh⇒Sh. Such a sequence indicates cyclic sheet-floods. During a small but dynamic advance of the ice sheet terminus, these deposits were moved forward and monoclinally folded, then furrowed with sloping faults due to horizontal pressure. Typical thrust-block push moraines developed in this way. Ice sheet advance took place when permafrost was present in the substratum and very high water pressure occurred at glacial terminus. Inside a lobal configuration of moraines, there is a rich inventory of glacial forms with a classic terminal depression in the central part. Based on this landform pattern, their shape, rhythm and glaciotectonic disturbances, the land relief may be referred to as a hill-hole pair. The structure of Horczaki Knoll, deposited on the sub-Quaternary tectonic structure, significantly contributed to a development of this marginal zone.

  1. Improvements in data analysis obtained by large-area silicon ΔE - E detector telescopes

    International Nuclear Information System (INIS)

    The paper describes a few practical methods for the analysis of data obtained by standard thin-thick silicon detector telescopes used in nuclear reaction measurements. The addressed issues are: (1) improvement in double-sided silicon strip detector (DSSSD) calibration based on the fact that each event is registered twice, both in horizontal and vertical strips, (2) improvements in particle identification and (3) simplified mapping of the non-uniformity of the thin detector, without a dedicated measurement of the thickness. The proposed procedures are applied on experimental data obtained for 30MeV 7Li beam induced reactions on LiF and C targets, studied with a detection setup consisting of four telescopes placed at different angles and distances. The proposed methods aim at quicker and more reliable calibration and particle identification. (orig.)

  2. Improvements in data analysis obtained by large-area silicon ΔE - E detector telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Uroic, M.; Miljanic, D.; Prepolec, L.; Soic, N. [Ruder Boskovic Institute, Zagreb (Croatia); Milin, M. [University of Zagreb, Department of Physics, Faculty of Science, Zagreb (Croatia); Di Pietro, A.; Figuera, P.; Fisichella, M.; Pellegriti, M.G.; Scuderi, V. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Lattuada, M. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Universtita' di Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); Martel, I. [Universidad de Huelva, Departamento de Fisica Aplicada, Huelva (Spain); Sanchez Benitez, A.M. [Universidad de Huelva, Departamento de Fisica Aplicada, Huelva (Spain); Universidade de Lisboa, Centro de Fisica Nuclear da, Lisboa (Portugal); Strano, E.; Torresi, D. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Laboratori Nazionali di Legnaro, INFN, Legnaro (Italy)

    2015-08-15

    The paper describes a few practical methods for the analysis of data obtained by standard thin-thick silicon detector telescopes used in nuclear reaction measurements. The addressed issues are: (1) improvement in double-sided silicon strip detector (DSSSD) calibration based on the fact that each event is registered twice, both in horizontal and vertical strips, (2) improvements in particle identification and (3) simplified mapping of the non-uniformity of the thin detector, without a dedicated measurement of the thickness. The proposed procedures are applied on experimental data obtained for 30MeV {sup 7}Li beam induced reactions on LiF and C targets, studied with a detection setup consisting of four telescopes placed at different angles and distances. The proposed methods aim at quicker and more reliable calibration and particle identification. (orig.)

  3. High-rate deposition of microcrystalline silicon in a large-area PECVD reactor and integration in tandem solar cells

    OpenAIRE

    Parascandolo, G; Bugnon, G.; Feltrin, A.; Ballif, C.

    2010-01-01

    We study the high-rate deposition of microcrystalline silicon in a large-area plasma-enhanced chemical-vapor-deposition (PECVD) reactor operated at 40.68 MHz, in the little-explored process conditions of high-pressure and high-silane concentration and depletion. Due to the long gas residence time in this process, the silane gas is efficiently depleted using moderate feed-in power density, thus facilitating up-scaling of the process to large surfaces. As observed in more traditional deposition...

  4. Influence of stain etching on low minority carrier lifetime areas of multicrystalline silicon for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Montesdeoca-Santana, A. [Departamento de Fisica Basica, Universidad de La Laguna, Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain); Fraunhofer Institute for Solar Energy Systems, Laboratory and Servicecenter Gelsenkirchen, Auf der Reihe 2, 45884 Gelsenkirchen (Germany); Gonzalez-Diaz, B. [Departamento de Fisica Basica, Universidad de La Laguna, Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain); Departamento de Energia Fotovoltaica, Instituto Tecnologico y de Energias Renovables. Poligono Industrial de Granadilla s/n, 38600 San Isidro-Granadilla de Abona (Spain); Jimenez-Rodriguez, E. [Departamento de Fisica Basica, Universidad de La Laguna, Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain); Ziegler, J. [Fraunhofer Institute for Solar Energy Systems, Laboratory- and Servicecenter Gelsenkirchen. Auf der Reihe 2, 45884 Gelsenkirchen (Germany); Velazquez, J.J. [Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna. Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain); Hohage, S.; Borchert, D. [Fraunhofer Institute for Solar Energy Systems, Laboratory and Servicecenter Gelsenkirchen. Auf der Reihe 2, 45884 Gelsenkirchen (Germany); Guerrero-Lemus, R., E-mail: rglemus@ull.es [Departamento de Fisica Basica, Universidad de La Laguna, Avda. Astrofisico Francisco Sanchez, 38206 La Laguna (Spain)

    2011-11-15

    Highlights: > An enhanced minority carrier lifetime at extended defects in multicrystalline silicon is observed with the use of HF/HNO{sub 3} stain etching to texture the surface. > FTIR analysis shows no influence of oxide passivation in this effect. > SEM images show a preferential etching at extended defects suggesting smoothing at defects as one of the causes for the reduced recombination activity. > LBIC images show a reduction in IQE at extended defects in HF/HNO{sub 3} textured multicrystalline solar cells. - Abstract: In this work the use of HF/HNO{sub 3} solutions for texturing silicon-based solar cell substrates by stain etching and the influence of texturing on minority carrier lifetimes are studied. Stain etching is currently used to decrease the reflectance and, subsequently improve the photogenerated current of the cells, but also produces nanostructures on the silicon surface. In the textured samples it has been observed that an improvement on the minority carrier lifetime with respect to the samples treated with a conventional saw damage etching process is produced on grain boundaries and defects, and the origin of this effect has been discussed.

  5. Temperature-Dependent Photoluminescence Imaging and Characterization of a Multi-Crystalline Silicon Solar Cell Defect Area: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, S.; Yan, F.; Li, J.; Romero, M. J.; Al-Jassim, M.; Zaunbrecher, K.; Sidelkheir, O.; Blosse, A.

    2011-07-01

    Photoluminescence (PL) imaging is used to detect areas in multi-crystalline silicon that appear dark in band-to-band imaging due to high recombination. Steady-state PL intensity can be correlated to effective minority-carrier lifetime, and its temperature dependence can provide additional lifetime-limiting defect information. An area of high defect density has been laser cut from a multi-crystalline silicon solar cell. Both band-to-band and defect-band PL imaging have been collected as a function of temperature from ~85 to 350 K. Band-to-band luminescence is collected by an InGaAs camera using a 1200-nm short-pass filter, while defect band luminescence is collected using a 1350-nm long pass filter. The defect band luminescence is characterized by cathodo-luminescence. Small pieces from adjacent areas within the same wafer are measured by deep-level transient spectroscopy (DLTS). DLTS detects a minority-carrier electron trap level with an activation energy of 0.45 eV on the sample that contained defects as seen by imaging.

  6. Fabrication of Large-Area Hierarchical Structure Array Using Siliconized-Silsesquioxane as a Nanoscale Etching Barrier.

    Science.gov (United States)

    Lee, Bong Kuk; Baek, In-Bok; Kim, Yarkyeon; Jang, Won Ick; Yoon, Yong Sun; Yu, Han Young

    2015-06-24

    A material approach to fabricate a large-area hierarchical structure array is presented. The replica molding and oxygen (O2) plasma etching processes were combined to fabricate a large-area hierarchical structure array. Liquid blends consisting of siliconized silsesquioxane acrylate (Si-SSQA), ethylene glycol dimethacrylate (EGDMA), and photoinitiator are developed as a roughness amplifying material during O2 plasma etching. Microstructures composed of the Si-SSQA/EGDMA mixtures are fabricated by replica molding. Nanoscale roughness on molded microstructures is realized by O2 etching. The nanoscale roughness on microstructures is efficiently controlled by varying the etching time and the weight ratio of Si-SSQA to EGDMA. The hierarchical structures fabricated by combining replica molding and O2 plasma etching showed superhydrophilicity with long-term stability, resulting in the formation of hydroxyl-terminated silicon oxide layer with the reorientation limit. On the other hand, the hierarchical structures modified with a perfluorinated monolayer showed superhydrophobicity. The increment of water contact angles is consistent with increment of the nano/microroughness of hierarchical structures and decrement of the top contact area of water/hierarchical structures. PMID:26047057

  7. Closure Report (CR) for Corrective Action Unit (CAU) 91: Area 3 U-3fi Injection Well with Errata Sheet and Certification, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Navarro Nevada Environmental Services

    2010-08-10

    The closure report for CAU 91 has no Use Restriction Form or drawing/map included in the document to describe the use restricted area, however, Section 3.3.3 states that the site will be fenced and signage placed indicating the area as a Resource Conservation and Recovery Act (RCRA) Unit. The drawing that was placed in the FFACO indicating the use restricted area lists the coordinates for the RCRA Unit in Nevada State Plan Coordinates - North American Datum of 1983. In the ensuing years the reporting of coordinates has been standardized so that all coordinates are reported in the same manner, which is: NAD 27 UTM Zone 11 N, meters. This Errata Sheet updates the coordinate reporting to the currently accepted method and includes an aerial photo showing the RCRA Unit with the coordinates listed showing the use restricted area.

  8. A flexible tactile sensitive sheet using a hetero-core fiber optic sensor

    Science.gov (United States)

    Fujino, S.; Yamazaki, H.; Hosoki, A.; Watanabe, K.

    2014-05-01

    In this report, we have designed a tactile sensitive sheet based on a hetero-core fiber-optic sensor, which realize an areal sensing by using single sensor potion in one optical fiber line. Recently, flexible and wide-area tactile sensing technology is expected to applied to acquired biological information in living space and robot achieve long-term care services such as welfare and nursing-care and humanoid technology. A hetero-core fiber-optic sensor has several advantages such as thin and flexible transmission line, immunity to EMI. Additionally this sensor is sensitive to moderate bending actions with optical loss changes and is independent of temperature fluctuation. Thus, the hetero-core fiber-optic sensor can be suitable for areal tactile sensing. We measure pressure characteristic of the proposed sensitive sheet by changing the pressure position and pinching characteristic on the surface. The proposed tactile sensitive sheet shows monotonic responses on the whole sensitive sheet surface although different sensitivity by the position is observed at the sensitive sheet surface. Moreover, the tactile sensitive sheet could sufficiently detect the pinching motion. In addition, in order to realize the discrimination between pressure and pinch, we fabricated a doubled-over sensor using a set of tactile sensitive sheets, which has different kinds of silicon robbers as a sensitive sheet surface. In conclusion, the flexible material could be given to the tactile sensation which is attached under proposed sensitive sheet.

  9. Full Simulation of the New Generation Windowless Large Area Silicon-Box for SIRIUS-S3

    International Nuclear Information System (INIS)

    The SPIRAL2 major installation is built in order to study rare elements through production of radioactive isotopes. Its injector, a superconducting linear accelerator (LINAC) is designed to provide very high intensity deuteron and stables beams up to ∼ 1014 part/s for ions between carbon and uranium. The 'Super Separator Spectrometer' (S3) was designed to separate and mass-analyse recoils from the various induced fusion-evaporation reactions in order to enable nuclear structure studies of proton-rich rare isotopes around 100Sn and in the Super Heavy Elements region. A new optimized focal plan detection system called SIRIUS for 'Spectroscopy and Identification of Rare Isotopes Using S3' is developed within the SIRIUS collaboration. The new generation windowless large area silicon-box developed in this framework is discussed in this article. We present the simulations done in order to determine the best geometry and layout for this large area silicon detector assembly. (authors)

  10. Plasma texturing on large-area industrial grade CZ silicon solar cells

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Nordseth, Ørnulf; Boisen, Anja;

    2013-01-01

    , and thus holds a significant potential for improvement of the cell performance compared to current industrial standards. The reflectance is shown to remain below that of conventional textured cells also at high angle of incidence. The process is shown to be equally applicable to mono-, multi- and...... quasi-mono-crystalline Si. The process was successfully integrated in fabrication of solar cells using only industry standard processes on a Czochralski (CZ) silicon starting material. The resulting cell performance was compared to cells with conventional texturing. For cells, where the nanostructuring...

  11. Identification of critical areas of carotid stent navigation by measurement of resistive forces in vitro, using silicone phantoms

    International Nuclear Information System (INIS)

    Manipulation of surgical tools in neuro-endovascular surgery presents problems that are unique to this procedure. Navigating tools through arterial complexities without appropriate visual or force feedback information often causes tool snagging, plaque dislocations and formation of thrombosis from the damage of the arterial wall by the tools. Identifying the critical areas in the vasculature during navigation of endovascular tools, will not only ensure safer surgical planning but also reduce risks of vessel damage. In the present research, resistive forces of stent navigation were measured in-vitro using silicone phantoms and clinically relevant surgical devices. The patterns of variation of the forces along the path of the stent movement were analyzed and mapped along the path of stent movement using a color code. It was observed that the forces changed along the length of the vessel, independent of the insertion length but based on the curvature of the vessel and the contact area of the device in the vessel lumen. (orig.)

  12. Nanostructured arrays of stacked graphene sheets

    International Nuclear Information System (INIS)

    Molecular oxygen etching of HOPG surfaces prepatterned by Ga+ focused-ion-beam irradiation (FIB) has been used to generate large-area arrays of nanometer-sized graphite blocks. AFM and SEM imaging show that structures with lateral sizes down to ∼100 nm and heights of between 30 and 55 nm can be routinely fabricated. The trenches separating the graphite blocks form in the early oxidation stages via preferential gasification (into CO and CO2) of the gridlike amorphized carbon regions written by FIB. In the later oxidative etching stages, gasification of the graphite nanoprism faces laterally terminating the graphite blocks becomes the major reaction channel. Correspondingly, graphite blocks are (further) reduced in lateral extent while the trenches in between are widened. Raman and photoionization spectroscopies indicate that the quality of the topmost nG sheet(s) covering the blocks also decreases with increasing etching time—as the size and lateral density of defect-mediated etch pits increases. nG block arrays are useful substrates with which to probe the size-dependent properties of nanographene, as they comprise large numbers of uniform sheets (ca. 4 × 1010 cm−2 for an array of 0.5 × 0.5 μm2) thus allowing for the application of area-integrating spectroscopic methods. We demonstrate this by examining the Raman features of nG block arrays which include a graphene-rim-region fingerprint mode. Individual nG sheets can be exfoliated from nG stacks by means of electron-irradiation-induced charging. We have explored a number of printing/manipulation strategies aimed at controllable electromechanical transfer of nG sheet arrays to silicon wafers. (paper)

  13. Large-area silica nanotubes with controllable geometry on silicon substrates

    Science.gov (United States)

    Hu, Mingzhe; Yu, Rong; MacManus-Driscoll, Judith L.; Robinson, Adam P.

    2009-01-01

    The synthesis of a highly uniform, large-scale nanoarrays consisting of silica nanotubes above embedded nanohole arrays in silicon substrates is demonstrated. In situ anodized aluminium oxide (AAO) thin film masks on Si substrates were employed, and the nanotubes were fabricated by Ar ion milling through the masks. The geometries of the nanoarrays, including pore diameter, interpore distance and the length of both nanopores and nanotubes could be controlled by the process parameters, which included that the outer pore diameter of silica tube was tuned from ˜80 nm to ˜135 nm while the inner tube diameter from ˜40 nm to ˜65 nm, the interpore distance of the nanotube arrays was from 100 nm to 180 nm and the length of silica tube changed from ˜90 nm to ˜250 nm. The presented nanostructure fabrication method has strong potential for application in intensity and frequency adjustable high luminescence efficiency optoelectronic devices.

  14. Characterization of Environmental Dust in the Dammam Area and Mud After-Effects on Bisphenol-A Polycarbonate Sheets

    Science.gov (United States)

    Yilbas, Bekir Sami.; Ali, Haider; Al-Aqeeli, Naseer; Khaled, Mazen M.; Said, Syed; Abu-Dheir, Numan; Merah, Necar; Youcef-Toumi, Kamal; Varanasi, Kripa K.

    2016-04-01

    Owing to recent climate changes, dust storms are increasingly common, particularly in the Middle East region. Dust accumulation and subsequent mud formation on solid surfaces in humid environments typically have adverse effects on surface properties such as optical transmittance, surface texture, and microhardness. This is usually because the mud, which contains alkaline and ionic species, adheres strongly to the surface, often through chemical bonds, and is therefore difficult to remove. In this study, environmental dust and the after-effects of mud formed on a polycarbonate sheet, which is commonly used as a protective glass in photovoltaic cells. Ionic compounds (OH‑) are shown to significantly affect the optical, mechanical, and textural characteristics of the polycarbonate surface, and to increase the adhesion work required to remove the dry mud from the polycarbonate surface upon drying. Such ability to modify characteristics of the polycarbonate surface could address the dust/mud-related limitations of superhydrophobic surfaces.

  15. Hydrogeochemistry of Groundwater as Part of the Greenland Analogue Project in an Area of Continuous Permafrost Adjacent to the Greenland Ice Sheet, Kangerlussuaq, West Greenland

    Science.gov (United States)

    Henkemans, E.; Frape, S.; Ruskeeniemi, T.; Claesson-Liljedahl, L.; Lehtinen, A.; Annable, W. K.

    2011-12-01

    Studying groundwater in areas of continuous permafrost is often limited to studies of springs and open pingos (eg. Pollard et al. 1999 and Allen et al. 1976). Boreholes in such locations are expensive, risky and logistically challenging (eg. Stotler et al. 2011) resulting in a limited understanding of the interaction between continental scale ice sheets and groundwater. Continental ice sheet models are often coupled to groundwater flow systems; however, there is a lack of modern field data with which to compare the results of models and their treatment of groundwater flow systems under the influence of glaciation. The Greenland Analogue Project (GAP) aims to eliminate some of the uncertainties in modeling ice sheets by using the Greenland ice sheet as a modern analogue for past glaciations. Since 2009, 3 boreholes have been drilled, 2 of which contain sampling systems. DH-GAP01 is a 191 m deep borehole drilled at an angle into a talik and has been sampled and studied since 2009. DH-GAP04 is a 632 m deep, angled borehole that intersects the groundwater flow system directly beneath Isunguata Sermia and is producing preliminary groundwater samples. Additional information on groundwater in the Kangerlussuaq area comes from a spring located directly in front of the Leverett ice lobe. Geochemical and isotopic (δ18O, δ2H, δ37Cl, 87Sr/86Sr, and δ34S and δ18O of SO4) tools are used to interpret geochemical processes acting on groundwaters and provide insight into groundwater flow. Analyses of δ18O and δ2H in groundwaters from DH-GAP01 show the borehole waters fall along the Global Meteoric Water Line (GMWL). Evaporation is an important process affecting the δ18O-δ2H of surface waters in the region causing lakes to plot along a local evaporation line (Leng and Anderson, 2003). The waters from the Leverett spring plot to the right of the GMWL as possibly a mixture of groundwater and surface evaporated fluids. However, both the waters from DH-GAP01 and the Leverett

  16. Large-Area, UV-Optimized, Back-Illuminated Silicon Photomultiplier Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Large-area (3m2), UV-sensitive focal plane arrays are needed for observation of air showers from ultra-high energy cosmic rays (JEM-EUSO) as well as for...

  17. Effect of high sheet-resistance emitter on mono-crystalline silicon solar cells performance%高方块电阻发射区对单晶硅太阳电池性能影响

    Institute of Scientific and Technical Information of China (English)

    沈洲; 沈鸿烈; 马跃; 夏正月; 陈军

    2012-01-01

    研究通过提高发射区的方块电阻和采用合适的工艺技术,制备了性能优良的单晶硅太阳电池.采用丝网印刷技术制备了40 Ω/□常规发射区和60 Ω/□高方块电阻发射区单晶硅太阳电池并对其性能进行了分析研究.扩展电阻法分析表明:60Ω/□发射区的表面活性磷杂质浓度和结深比40Ω/□发射区的分别降低了12.8%和14.9%.尽管60 Ω/□发射区太阳电池的串联电阻增加了0.141 Ω/cm2导致填充因子下降了1.24%,但是短路电流密度和开路电压分别提高了1.31 mA/cm2和1.2 mV,最终转换效率仍然提高了0.4%.%The high quality mono-crystalline silicon solar cells were achieved by increasing the sheet-resistance of the emitters and using the favorable technology processing. The mono-crystalline silicon solar cells with 40 ft/D and 60 ft/D emitters were fabricated with screen-printed contacts and their properties were studied. The spreading resistance profiles analysis shows that there is a 12.8% decrease in the surface active phosphorus concentration and a 14.9% decrease in the junction depth for mono-crystalline silicon solar cells with 60 fl/D emitter compared with the conventional solar cells with 40 ft/ □ emitter. The mono-crystalline silicon solar cells with 60 ft/ □ emitter demonstrate an improvement of 1.31 mA/cm2 in short current density, 1.2 mV in open-circuit voltage, and thus 0.4% higher in energy conversion efficiency, in spite of a 1.24% loss in fill factor resulted from a 0.141 ft/cm2 increase in series resistance compared with the conventional solar cells with 40 ft/D emitter.

  18. Experimental characterization of the rectification process in ammonia-water absorption systems with a large-specific-area corrugated sheet structured packing

    Energy Technology Data Exchange (ETDEWEB)

    Sieres, Jaime; Fernandez-Seara, Jose; Uhia, Francisco J. [Area de Maquinas y Motores Termicos, E.T.S. de Ingenieros Industriales, Campus Lagoas-Marcosende No 9, 36310 Vigo, Pontevedra (Spain)

    2009-09-15

    In this paper, the mass transfer performance of a large-specific-area corrugated sheet structured packing for ammonia-water absorption refrigeration systems (AARS) is reported. An experimental facility was used to test the performance of the packing. Experimental results of the temperature, ammonia concentration and mass flow rate of the rectified vapour are presented and discussed for different operating conditions including reflux ratio values from 0.2 to 1. The volumetric vapour phase mass transfer coefficient is calculated from the measured data and compared with different correlations found in the literature. A new correlation is proposed which was fitted from the experimental data. Finally, a comparison is made between the actual packing height used in the experimental setup and the height required to obtain the same ammonia rectification in AARS with different packings previously tested by the authors. (author)

  19. Colorado River Wildlife Management Area (Colorado and Gunnison River Easements) [Land Status Map: Sheet 2 of 2

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This map was produced by the Division of Realty to depict landownership at Colorado River Wildlife Management Area. It was generated from rectified aerial...

  20. Thin film silicon photovoltaics: Architectural perspectives and technological issues

    Energy Technology Data Exchange (ETDEWEB)

    Mercaldo, Lucia Vittoria; Addonizio, Maria Luisa; Noce, Marco Della; Veneri, Paola Delli; Scognamiglio, Alessandra; Privato, Carlo [ENEA, Portici Research Center, Piazzale E. Fermi, 80055 Portici (Napoli) (Italy)

    2009-10-15

    Thin film photovoltaics is a particularly attractive technology for building integration. In this paper, we present our analysis on architectural issues and technological developments of thin film silicon photovoltaics. In particular, we focus on our activities related to transparent and conductive oxide (TCO) and thin film amorphous and microcrystalline silicon solar cells. The research on TCO films is mainly dedicated to large-area deposition of zinc oxide (ZnO) by low pressure-metallorganic chemical vapor deposition. ZnO material, with a low sheet resistance (<8 {omega}/sq) and with an excellent transmittance (>82%) in the whole wavelength range of photovoltaic interest, has been obtained. ''Micromorph'' tandem devices, consisting of an amorphous silicon top cell and a microcrystalline silicon bottom cell, are fabricated by using the very high frequency plasma enhanced chemical vapor deposition technique. An initial efficiency of 11.1% (>10% stabilized) has been obtained. (author)

  1. Single-grain Silicon Technology for Large Area X-ray Imaging

    OpenAIRE

    Arslan, A

    2015-01-01

    Digital flat panel X-ray imagers are currently using a-Si and poly-Si thin-film-transistors (TFTs). a-Si TFT permits the use of large area substrates, however, due to the amorphous nature, the carrier mobility is very low (

  2. Single-grain Silicon Technology for Large Area X-ray Imaging

    NARCIS (Netherlands)

    Arslan, A.

    2015-01-01

    Digital flat panel X-ray imagers are currently using a-Si and poly-Si thin-film-transistors (TFTs). a-Si TFT permits the use of large area substrates, however, due to the amorphous nature, the carrier mobility is very low (<1 cm2/Vs). Poly-Si TFT improves the mobility (~150 cm2/Vs) but due to random

  3. Potential application of mono/bi-layer molybdenum disulfide (MoS2) sheet as an efficient transparent conducting electrode in silicon heterojunction solar cells

    Science.gov (United States)

    Chaudhary, Rimjhim; Patel, Kamlesh; Sinha, Ravindra K.; Kumar, Sanjeev; Tyagi, Pawan K.

    2016-07-01

    In this paper, we have simulated the structure of n-type MoS2/silicon heterojunction solar cell and studied its function under different conditions. The optimization of parameters of the cell's layer has been carried out by using AFORS-HET software. In the present study, MoS2 has been considered as 3-D in nature instead of the reported 2-D nature. In order to ensure the formation of Schottky junction, electric contact has been made along the c-axis to collect the minority charge carriers. After optimizing the various parameters of n-type single layer MoS2, power efficiency of 12.44% has been achieved at the room temperature, which has further decreased to 9.042% as the layer number has increased up to 40. Furthermore, after optimizing the parameters of silicon wafer maximum efficiency of 16.4% has been achieved. Temperature dependence of the cell performance has also been studied and the maximum efficiency has been achieved at 300 K. In the present study, we have demonstrated that n-type ultrathin layer of MoS2 can be used as an excellent transparent conducting electrode.

  4. Envisat-derived elevation changes of the Greenland ice sheet, and a comparison with ICESat results in the accumulation area

    DEFF Research Database (Denmark)

    Sørensen, Louise Sandberg; Simonsen, Sebastian Bjerregaard; Meister, Rakia;

    2015-01-01

    both the laser altimeter on board ICESatand the radar altimeter on board Envisat. We compare rates of elevation change derived from ICESat and Envisat for this time span inwhich both sensors were operating.We focus on the area above the equilibrium line altitude, in order to specifically derive...

  5. ERRATA SHEET for Corrective Action Plan for Corrective Action Unit 490: Station 44 Burn Area, Tonopah Test Range, Nevada; TOPICAL

    International Nuclear Information System (INIS)

    Section 2.1.1.3 of the Table of Contents reference on Page v and on Page 12 of the Corrective Action Plan for Corrective Action Unit 490: Station 44 Burn Area, Tonopah Test Range, Nevada erroneously refers to the Nevada Environmental Policy Act Determination. The correct title of the referenced document is the National Environmental Policy Act Determination

  6. 利用二次冷轧法改善高硅钢薄带的再结晶织构∗%Improvement of recrystallization texture in high silicon steel shin sheets by two-stage cold rolling method

    Institute of Scientific and Technical Information of China (English)

    柳金龙; 沙玉辉; 张芳; 李继超; 左良

    2015-01-01

    采用传统的轧制和退火工艺制备了厚0.20 mm的6.5%(质量分数)Si高硅钢薄带,采用X射线衍射技术对不同冷轧工艺下高硅钢薄带的再结晶织构进行了研究.研究表明,与一次冷轧法相比,二次冷轧法可明显减弱对磁性能不利的γ再结晶织构,而且通过合理分配一次和二次冷轧压下率,二次冷轧法可完全消除γ再结晶织构,并形成强η再结晶织构.通过二次冷轧法调整形变微结构,促使剪切带成为再结晶的主导形核位置,是改善高硅钢薄带再结晶织构的有效途径.%High silicon steel thin sheets with thickness of 0.20 mm were produced by conventional rolling and annealing methods.Recrystallization texture under different cold rolling process was investigated by means of X-ray diffraction.Compared with the one-stage cold rolling method,the two-stage cold rolling method was benefi-cial to weaken the adverseγrecrystallization texture.Furthermore,by properly assigning the reduction of first and second cold rolling,γrecrystallization texture can be completely eliminated and strongηrecrystallization texture develops.It was an effective way to improve the recrystallization texture of high silicon steel thin sheet that priority of nucleation at shear bands dominates the recrystallization by modifying the deformation micro-structure using two-stage cold rolling method..

  7. Recent increase in snow-melt area in the Greenland Ice sheet as an indicator of the effect of reduced surface albedo by snow impurities

    Science.gov (United States)

    Rikiishi, K.

    2008-12-01

    Recent rapid decline of cryosphere including mountain glaciers, sea ice, and seasonal snow cover tends to be associated with global warming. However, positive feedback is likely to operate between the cryosphere and air temperature, and then it may not be so simple to decide the cause-and-effect relation between them. The theory of heat budget for snow surface tells us that sensible heat transfer from the air to the snow by atmospheric warming by 1°C is about 10 W/m2, which is comparable with heat supply introduced by reduction of the snow surface albedo by only 0.02. Since snow impurities such as black carbon and soil- origin dusts have been accumulated every year on the snow surface in snow-melting season, it is very important to examine whether the snow-melting on the ice sheets, mountain glaciers, and sea ice is caused by global warming or by accumulated snow impurities originated from atmospheric pollutants. In this paper we analyze the dataset of snow-melt area in the Greenland ice sheet for the years 1979 - 2007 (available from the National Snow and Ice Data Center), which is reduced empirically from the satellite micro-wave observations by SMMR and SMM/I. It has been found that, seasonally, the snow-melt area extends most significantly from the second half of June to the first half of July when the sun is highest and sunshine duration is longest, while it doesn't extend any more from the second half of July to the first half of August when the air temperature is highest. This fact may imply that sensible heat required for snow-melting comes from the solar radiation rather than from the atmosphere. As for the interannual variation of snow-melt area, on the other hand, we have found that the growth rate of snow-melt area gradually increases from July, to August, and to the first half of September as the impurities come out to and accumulated at the snow surface. However, the growth rate is almost zero in June and the second half of September when fresh snow

  8. Microfabrication of large-area circular high-stress silicon nitride membranes for optomechanical applications

    Directory of Open Access Journals (Sweden)

    E. Serra

    2016-06-01

    Full Text Available In view of the integration of membrane resonators with more complex MEMS structures, we developed a general fabrication procedure for circular shape SiNx membranes using Deep Reactive Ion Etching (DRIE. Large area and high-stress SiNx membranes were fabricated and used as optomechanical resonators in a Michelson interferometer, where Q values up to 1.3 × 106 were measured at cryogenic temperatures, and in a Fabry-Pérot cavity, where an optical finesse up to 50000 has been observed.

  9. Near-infrared electroluminescence and photo detection in InGaAs p-i-n microdisks grown by selective area growth on silicon

    International Nuclear Information System (INIS)

    Microselective-area growth of p-i-n InGaAs disks on (111) silicon by metalorganic chemical vapor deposition is a promising technology for III/V-on-Si integration. As a proof-of-concept, room-temperature electroluminescence is reported from ensembles of p-i-n InGaAs-on-Si micro-disks. The observed spectrum shows peak luminescence at 1.78 μm with a local maxima at 1.65 μm. The disks are also shown to generate a measurable photo current when illuminated by infrared light with less energy than the silicon bandgap energy. This makes these InGaAs-on-Si disks a promising technology for monolithic integration of light sources and detectors with silicon photonics and complementary metal-oxide-semiconductor electronics for optical communication, sensing, and imaging.

  10. Printed Large-Area Single-Mode Photonic Crystal Bandedge Surface-Emitting Lasers on Silicon.

    Science.gov (United States)

    Zhao, Deyin; Liu, Shihchia; Yang, Hongjun; Ma, Zhenqiang; Reuterskiöld-Hedlund, Carl; Hammar, Mattias; Zhou, Weidong

    2016-01-01

    We report here an optically pumped hybrid III-V/Si photoic crystal surface emitting laser (PCSEL), consisting of a heterogeneously integrated III-V InGaAsP quantum well heterostructure gain medium, printed on a patterned defect-free Si photonic crystal (PC) bandedge cavity. Single mode lasing was achieved for a large area laser, with a side-mode suppression ratio of 28 dB, for lasing operation temperature ~ 200 K. Two types of lasers were demonstrated operating at different temperatures. Detailed modal analysis reveals the lasing mode matches with the estimated lasing gain threshold conditions. Our demonstration promises a hybrid laser sources on Si towards three-dimensional (3D) integrated Si photonics for on-chip wavelength-division multiplex (3D WDM) systems for a wide range of volume photonic/electronic applications in computing, communication, sensing, imaging, etc. PMID:26727551

  11. Printed Large-Area Single-Mode Photonic Crystal Bandedge Surface-Emitting Lasers on Silicon

    Science.gov (United States)

    Zhao, Deyin; Liu, Shihchia; Yang, Hongjun; Ma, Zhenqiang; Reuterskiöld-Hedlund, Carl; Hammar, Mattias; Zhou, Weidong

    2016-01-01

    We report here an optically pumped hybrid III-V/Si photoic crystal surface emitting laser (PCSEL), consisting of a heterogeneously integrated III-V InGaAsP quantum well heterostructure gain medium, printed on a patterned defect-free Si photonic crystal (PC) bandedge cavity. Single mode lasing was achieved for a large area laser, with a side-mode suppression ratio of 28 dB, for lasing operation temperature ~200 K. Two types of lasers were demonstrated operating at different temperatures. Detailed modal analysis reveals the lasing mode matches with the estimated lasing gain threshold conditions. Our demonstration promises a hybrid laser sources on Si towards three-dimensional (3D) integrated Si photonics for on-chip wavelength-division multiplex (3D WDM) systems for a wide range of volume photonic/electronic applications in computing, communication, sensing, imaging, etc.

  12. Tunnel oxide passivated rear contact for large area n-type front junction silicon solar cells providing excellent carrier selectivity

    Directory of Open Access Journals (Sweden)

    Yuguo Tao

    2016-01-01

    Full Text Available Carrier-selective contact with low minority carrier recombination and efficient majority carrier transport is mandatory to eliminate metal-induced recombination for higher energy conversion efficiency for silicon (Si solar cells. In the present study, the carrier-selective contact consists of an ultra-thin tunnel oxide and a phosphorus-doped polycrystalline Si (poly-Si thin film formed by plasma enhanced chemical vapor deposition (PECVD and subsequent thermal crystallization. It is shown that the poly-Si film properties (doping level, crystallization and dopant activation anneal temperature are crucial for achieving excellent contact passivation quality. It is also demonstrated quantitatively that the tunnel oxide plays a critical role in this tunnel oxide passivated contact (TOPCON scheme to realize desired carrier selectivity. Presence of tunnel oxide increases the implied Voc (iVoc by ~ 125 mV. The iVoc value as high as 728 mV is achieved on symmetric structure with TOPCON on both sides. Large area (239 cm2 n-type Czochralski (Cz Si solar cells are fabricated with homogeneous implanted boron emitter and screen-printed contact on the front and TOPCON on the back, achieving 21.2% cell efficiency. Detailed analysis shows that the performance of these cells is mainly limited by boron emitter recombination on the front side.

  13. Large Area Silicon Carbide Vertical JFETs for 1200 V Cascode Switch Operation

    Directory of Open Access Journals (Sweden)

    Victor Veliadis

    2008-01-01

    Full Text Available SiC VJFETs are excellent candidates for reliable high-power/temperature switching as they only use pn junctions in the active device area where the high-electric fields occur. VJFETs do not suffer from forward voltage degradation, exhibit excellent short-circuit performance, and operate at 300°C. 0.19 cm2 1200 V normally-on and 0.15 cm2 low-voltage normally-off VJFETs were fabricated. The 1200-V VJFET outputs 53 A with a forward drain voltage drop of 2 V and a specific onstate resistance of 5.4 mΩ cm2. The low-voltage VJFET outputs 28 A with a forward drain voltage drop of 3.3 V and a specific onstate resistance of 15 mΩ cm2. The 1200-V SiC VJFET was connected in the cascode configuration with two Si MOSFETs and with a low-voltage SiC VJFET to form normally-off power switches. At a forward drain voltage drop of 2.2 V, the SiC/MOSFETs cascode switch outputs 33 A. The all-SiC cascode switch outputs 24 A at a voltage drop of 4.7 V.

  14. Silicon carbide bodies

    International Nuclear Information System (INIS)

    A self-bonded silicon carbide body produced by siliconising a preformed mixture of particles (shaped by means other than slip-casting) of carbon and silicon carbide in the beta form has a mean grain size in the range of 0.1 to 5 microns. Such a body may be produced using silicon carbide particles having a mean surface area in the range 0.5 to 20 square metres per gram. The silicon carbide particles may be produced by heating a mixture of silica and silicon to generate silicon monoxide vapour and passing the vapour through a bed of particulate carbon. (author)

  15. Large Area Synthesis of WS2 Crystalline Sheets Directly on SiO2 and Their Transfer to Other Substrates

    Science.gov (United States)

    Elias, Ana; Perea-Lopez, Nestor; Castro-Beltran, Andres; Berkdemir, Ayse; Feng, Simin; Lv, Ruitao; Long, Aaron; Hayashi, Takuya; Kim, Yoong; Endo, Morinobu; Gutierrez, Humberto; Ghosh, Sujoy; Talapatra, Saikat; Pradhan, Nihar; Balicas, Luis; Lopez-Urias, Florentino; Terrones, Humberto; Terrones, Mauricio

    2013-03-01

    Metal dichalcogenides (e.g. MoS2, WS2, NbS2) have attracted attention because they are layered materials that could exhibit either semiconducting or metallic properties. These properties could be significantly modified when these materials become monolayers. Here we report for the first time the synthesis of large area few-layer WS2 by a two step method. WOx thin films were first grown on a Si/SiO2 substrate and these films were sulfurized in a second step. Furthermore, we have developed an efficient route to transfer these WS2 films onto different substrates. WS2 films of different thicknesses have been analyzed by Raman spectroscopy, HRTEM and AFM. Characterization techniques demonstrate the presence of mono-, bi- and few-layered WS2 in the as-grown samples. The novel photoluminescence properties of the films will also be discussed. on leave from IPICyT

  16. Infused polymers for cell sheet release

    Science.gov (United States)

    Juthani, Nidhi; Howell, Caitlin; Ledoux, Haylea; Sotiri, Irini; Kelso, Susan; Kovalenko, Yevgen; Tajik, Amanda; Vu, Thy L.; Lin, Jennifer J.; Sutton, Amy; Aizenberg, Joanna

    2016-05-01

    Tissue engineering using whole, intact cell sheets has shown promise in many cell-based therapies. However, current systems for the growth and release of these sheets can be expensive to purchase or difficult to fabricate, hindering their widespread use. Here, we describe a new approach to cell sheet release surfaces based on silicone oil-infused polydimethylsiloxane. By coating the surfaces with a layer of fibronectin (FN), we were able to grow mesenchymal stem cells to densities comparable to those of tissue culture polystyrene controls (TCPS). Simple introduction of oil underneath an edge of the sheet caused it to separate from the substrate. Characterization of sheets post-transfer showed that they retain their FN layer and morphology, remain highly viable, and are able to grow and proliferate normally after transfer. We expect that this method of cell sheet growth and detachment may be useful for low-cost, flexible, and customizable production of cellular layers for tissue engineering.

  17. Various configurations for continuous silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sameh, M.

    1977-10-01

    For the same exposed silicon area, solar cells may be produced in a more convenient and mechanically rugged structure than narrow thin ribbons or sheets. Compactness ratio is calculated for each of several suggested geometries. For an Archimedes and square spirals, compactness ratio increases with increasing number of turns and closer tolerance. For a serpent, compactness ratio increases with decreasing number of turns, closer tolerance and increasing ratio of ribbon width to side length. For a zigzag compactness ratio is minimum for an apex angle 45/sup 0/ and smaller ratio of ribbon width to side length.

  18. 取向硅钢薄带形变再结晶组织及织构演变%Deformation and recrystallization texture and microstructure evolution of thin grain-oriented silicon steel sheets

    Institute of Scientific and Technical Information of China (English)

    毕娜; 张宁; 杨平

    2015-01-01

    利用背散射电子衍射微织构分析技术及X射线衍射织构分析技术,结合对取向硅钢薄带再结晶各阶段退火板磁性能的分析,系统研究了其形变再结晶过程中的组织及织构演变。结果表明,薄带内原始高斯晶粒取向发生绕TD轴向{111}的转变,同时晶粒取向还表现出绕RD轴的附加转动,这种附加转动及其导致的表层微弱立方形变组织可为再结晶立方织构的形成提供核心。退火各阶段样品磁性能的变化对应了{110}-{100}有益织构及其他织构的强弱转变以及再结晶晶粒不均匀程度的变化,综合织构类型及晶粒尺寸的变化推断发生了二次及三次再结晶过程。升温过程再结晶织构演变主要体现了织构诱发机制,也即与基体存在绕轴取向关系的晶粒长大优势结合高斯织构的抑制效应发挥作用;而在高温长时间保温后三次再结晶过程,{110}低表面能诱发异常长大发挥主要作用使得最终得到锋锐的高斯织构。%Combined with magnetic property measurements of thin grain-oriented silicon steel sheets annealed to different recrys-tallization stages, the deformation and recrystallization texture and microstructure evolution of the sheets was analyzed by using the electron back-scattering diffraction ( EBSD) micro-texture analysis technique and X-ray diffraction texture analysis technique. The results show that the deformation texture transforms from {110} to {111} about the transverse direction. Meanwhile, it should be noticed that additional crystal rotation about RD which leads to the occurrence of a weak{001} texture near the sheet surface appears in deformed grains, thus the origin of a cube recrystallization texture can be explained. As the annealing temperature increases, there occur abnormal grain growth and changes in magnetic properties, which are bound up with texture evolution including a beneficial {110} -{100} texture and other weak

  19. Thermal stability of standalone silicene sheet

    International Nuclear Information System (INIS)

    Extensive Monte Carlo simulations are carried out to study thermal stability of an infinite standalone silicon sheet. We used the Tersoff potential that has been used with success for silicon at low temperatures. However, the melting temperature Tm calculated with the original parameters provided by Tersoff is too high with respect to the experimental one. Agrawal, Raff and Komanduri have proposed a modified set of parameters to reduce Tm. For comparison, we have used these two sets of parameters to study the stability and the melting of a standalone 2D sheet of silicon called 'silicene', by analogy with graphene for the carbon sheet. We find that 2D crystalline silicene is stable up to a high temperature unlike in 2D systems with isotropic potentials such as Lennard-Jones. The differences in the obtained results using two sets of parameters are striking.

  20. Safety advice sheets

    CERN Multimedia

    HSE Unit

    2013-01-01

    You never know when you might be faced with questions such as: when/how should I dispose of a gas canister? Where can I find an inspection report? How should I handle/store/dispose of a chemical substance…?   The SI section of the DGS/SEE Group is primarily responsible for safety inspections, evaluating the safety conditions of equipment items, premises and facilities. On top of this core task, it also regularly issues “Safety Advice Sheets” on various topics, designed to be of assistance to users but also to recall and reinforce safety rules and procedures. These clear and concise sheets, complete with illustrations, are easy to display in the appropriate areas. The following safety advice sheets have been issued so far: Other sheets will be published shortly. Suggestions are welcome and should be sent to the SI section of the DGS/SEE Group. Please send enquiries to general-safety-visits.service@cern.ch.

  1. A Novel Methodology for Thermal Aware Silicon Area Estimation for 2D & 3D MPSoCs

    Directory of Open Access Journals (Sweden)

    Vinod Pangracious

    2012-01-01

    Full Text Available In a multiprocessor system on chip (MPSoC IC the processor is one of the highest heat dissipating devices. The temperature generated in an IC may vary with floor plan of the chip. This paper proposes an integration and thermal analysis methodology to extract the peak temperature and temperature distribution of 2-dimensional and 3-dimensional multiprocessor system-on-chip. As we know the peak temperature of chip increases in 3-dimensional structures compared to 2-dimensional ones due to the reduced space in intra-layer and inter-layer components. In sub-nanometre scale technologies, it is inevitable to analysis the heat developed in individual chip to extract the temperature distribution of the entire chip. With thetechnology scaling in new generation ICs more and more components are integrated to a smaller area. Along with the other parameters threshold voltage is also scaled down which results in exponential increase in leakage current. This has resulted in rise in hotspot temperature value due to increase inleakage power. In this paper, we have analysed the temperature developed in an IC with four identical processors at 2.4 GHz in different floorplans. The analysis has been done for both 2D and 3D arrangements. In the 3D arrangement, a three layered structure has been considered with two Silicon layers and a thermal interface material (TIM in between them. Based on experimental results the paperproposes a methodology to reduce the peak temperature developed in 2D and 3D integrated circuits .

  2. A Novel Methodology for Thermal Aware Silicon Area Estimation for 2D & 3D MPSoCs

    Directory of Open Access Journals (Sweden)

    Ramya Menon C

    2011-12-01

    Full Text Available In a multiprocessor system on chip (MPSoC IC the processor is one of the highest heat dissipating devices. The temperature generated in an IC may vary with floor plan of the chip. This paper proposes an integration and thermal analysis methodology to extract the peak temperature and temperature distribution of 2-dimensional and 3-dimensional multiprocessor system-on-chip. As we know the peak temperature of chip increases in 3-dimensional structures compared to 2-dimensional ones due to the reduced space in intra-layer and inter-layer components. In sub-nanometre scale technologies, it is inevitable to analysis the heat developed in individual chip to extract the temperature distribution of the entire chip. With the technology scaling in new generation ICs more and more components are integrated to a smaller area. Along with the other parameters threshold voltage is also scaled down which results in exponential increase in leakage current. This has resulted in rise in hot spot temperature value due to increase in leakage power. In this paper, we have analysed the temperature developed in an IC with four identical processors at 2.4 GHz in different floor plans. The analysis has been done for both 2D and 3D arrangements. In the 3D arrangement, a three layered structure has been considered with two Silicon layers and a thermal interface material (TIM in between them. Based on experimental results the paper proposes a methodology to reduce the peak temperature developed in 2D and 3D integrated circuits .

  3. Exploration of maximum count rate capabilities for large-area photon counting arrays based on polycrystalline silicon thin-film transistors

    Science.gov (United States)

    Liang, Albert K.; Koniczek, Martin; Antonuk, Larry E.; El-Mohri, Youcef; Zhao, Qihua

    2016-03-01

    Pixelated photon counting detectors with energy discrimination capabilities are of increasing clinical interest for x-ray imaging. Such detectors, presently in clinical use for mammography and under development for breast tomosynthesis and spectral CT, usually employ in-pixel circuits based on crystalline silicon - a semiconductor material that is generally not well-suited for economic manufacture of large-area devices. One interesting alternative semiconductor is polycrystalline silicon (poly-Si), a thin-film technology capable of creating very large-area, monolithic devices. Similar to crystalline silicon, poly-Si allows implementation of the type of fast, complex, in-pixel circuitry required for photon counting - operating at processing speeds that are not possible with amorphous silicon (the material currently used for large-area, active matrix, flat-panel imagers). The pixel circuits of two-dimensional photon counting arrays are generally comprised of four stages: amplifier, comparator, clock generator and counter. The analog front-end (in particular, the amplifier) strongly influences performance and is therefore of interest to study. In this paper, the relationship between incident and output count rate of the analog front-end is explored under diagnostic imaging conditions for a promising poly-Si based design. The input to the amplifier is modeled in the time domain assuming a realistic input x-ray spectrum. Simulations of circuits based on poly-Si thin-film transistors are used to determine the resulting output count rate as a function of input count rate, energy discrimination threshold and operating conditions.

  4. Synthesis of amino-functionalized mesoporous silica sheets and their application for metal ion capture

    Directory of Open Access Journals (Sweden)

    Kazuma Nakanishi

    2015-03-01

    Full Text Available Novel mesoporous silica sheets with surface amino-functional groups (sheet-NH2 were prepared for the efficient adsorption of aqueous metal ions. The sheet-NH2 were synthesized by a dual-templating process using Pluronic P123 and N-palmitoyl-l-alanine as templates. Two silicone regents were used to form the silica framework: tetraethoxysilane and 3-aminopropyltriethoxysilane. In the synthetic process, the as-prepared silicate was refluxed in ethanol to remove the organic templates remaining from the surface amino groups derived from APTES. The prepared sheet-NH2 showed widths of several micrometres and small thicknesses of approximately 50 nm. The pore diameter, pore volume and BET surface area of sheet-NH2 were determined by nitrogen adsorption–desorption isotherms to be 3.1 nm, 0.73 cm3 g−1 and 189.9 m2 g−1, respectively. TEM, XRD, FT-IR and TG–DTA analysis demonstrated that the sheet material had a disordered mesoporous structure and contained organic chains. The adsorptions of aqueous zinc(II and copper(II metal ions were examined and compared with amino-functionalized conventional mesoporous silica (MCM-NH2, calcined mesoporous silica sheets and silica beads with no porous structures. Notably, the sheet-NH2 exhibited the highest adsorption of both zinc and copper ions among the examined materials. In addition, the metal ion sorption equilibrium data of sheet-NH2 were fitted to the Langmuir isotherm model.

  5. Large area multicrystalline silicon solar cells in high volume production environment - history, status, new processes, technology transfer issues

    International Nuclear Information System (INIS)

    Cast multicrystalline silicon (mc-Si) solar cell technology, accounted for nearly 41% of all the PV modules manufactures worldwide in 2000. Since 1995 the use of cast mc-Si as a substrate has increased every year and that increase is expected to accelerate in the coming years as the PV market grows further. This impressive growth has been enabled by several factors - wafer suppliers, improvements in casting technology, sawing technology and cell process technology. In this paper the enabling factors will be discussed. The new processes used to enhance the efficiency of the cast multicrystalline silicon solar cells and the criteria for technology transfer will also be discussed. (author)

  6. Mr. Lorenzo Dellai, presidente della provincia Autonoma di Trento and Professor Andrea Zanotti, president dell'Instituto Trentino di Cultura, visit ALICE experiment underground area and Pixel Silicon Laboratory

    CERN Multimedia

    Claudia Marcelloni

    2006-01-01

    Mr. Lorenzo Dellai, presidente della provincia Autonoma di Trento and Professor Andrea Zanotti, president dell'Instituto Trentino di Cultura, visit ALICE experiment underground area and Pixel Silicon Laboratory

  7. The preparation of the poly(vinyl alcohol/graphene nanocomposites with low percolation threshold and high electrical conductivity by using the large-area reduced graphene oxide sheets

    Directory of Open Access Journals (Sweden)

    Q. Fu

    2013-09-01

    Full Text Available We report a method to prepare the poly(vinyl alcohol/reduced graphene oxide (PVA/rGO nanocomposites with low percolation threshold and high electrical conductivity by using the large-area reduced graphene oxide (LrGO sheets. The large-area graphene oxide (LGO sheets are expected to overlap better with each other and form the continuous GO network in PVA matrix than small-area graphene oxide (SGO. During the thermal reduction process, the LGO sheets are easily restored and improve the electrical conductivity of nanocomposites due to their low damage level of conjugate-structure. As a result, the percolation threshold of PVA/LrGO nanocomposites is ~0.189 wt% lower than present reports (0.5~0.7 wt%. At the LrGO content of 0.7 wt%, the electrical conductivity of PVA/LrGO nanocomposites reaches 6.3•10–3 S/m. Besides that, this method only takes 15~30 min to reduce the PVA/GO nanocomposites effectively.

  8. 挤塑板和苯板在高寒地区应用分析%Application of Extruded Sheet and Benzene Board in Extremely Cold Areas

    Institute of Scientific and Technical Information of China (English)

    郑江龙

    2011-01-01

    挤塑板与苯板保温系统相似,挤塑板具有极佳的保温性能、出色的抗压性能、极低的吸水率、良好的隔音稳定性、超长的耐久性能、较好的尺寸稳定性及抗蠕变性能.%Thermal insulation system of extruded sheet is similar to benzene board. Extruded sheet has excellent insulation properties, excellent compression performance, low water absorption, good noise stability, long durability, good dimensional stability and creep resistance.

  9. Porous silicon gettering

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S.; Menna, P.; Al-Jassim, M. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1995-08-01

    We have studied a novel extrinsic gettering method that utilizes the very large surface areas, produced by porous silicon etch on both front and back surfaces of the silicon wafer, as gettering sites. In this method, a simple and low-cost chemical etching is used to generate the porous silicon layers. Then, a high-flux solar furnace (HFSF) is used to provide high-temperature annealing and the required injection of silicon interstitials. The gettering sites, along with the gettered impurities, can be easily removed at the end the process. The porous silicon removal process consists of oxidizing the porous silicon near the end the gettering process followed by sample immersion in HF acid. Each porous silicon gettering process removes up to about 10 {mu}m of wafer thickness. This gettering process can be repeated so that the desired purity level is obtained.

  10. Silicon microphones - a Danish perspective

    DEFF Research Database (Denmark)

    Bouwstra, Siebe; Storgaard-Larsen, Torben; Scheeper, Patrick;

    1998-01-01

    Two application areas of microphones are discussed, those for precision measurement and those for hearing instruments. Silicon microphones are under investigation for both areas, and Danish industry plays a key role in both. The opportunities of silicon, as well as the challenges and expectations......, are discussed. For precision measurement the challenge for silicon is large, while for hearing instruments silicon seems to be very promising....

  11. Tectonic triggering of slump sheets in the Upper Cretaceous carbonate succession of the Porto Selvaggio area (Salento peninsula, southern Italy): Synsedimentary tectonics in the Apulian Carbonate Platform

    Science.gov (United States)

    Mastrogiacomo, G.; Moretti, M.; Owen, G.; Spalluto, L.

    2012-08-01

    Soft-sediment deformation structures crop out in the Upper Cretaceous carbonate succession in Porto Selvaggio cove in the western Salento peninsula, Apulian foreland, southern Italy. The deformed interval is about 13 m thick and occurs between shallow-water limestones and dolostones formed in peritidal and shallow subtidal environments. It comprises well-bedded grey mudstones interlayered with dark grey laminated microbioclastic wackestones characterized by couplets of closely spaced dark and bright laminae marked by the parallel orientation of calcareous microbioclasts and thin-shelled bivalves. The low biological diversity, scarcity of burrowing biota, and presence of a well preserved fish fauna provide evidence of anoxic conditions occurring in morphological depressions within the platform, and a stagnant, stratified water body affected by weak bottom currents, indicating the sudden development of a localised and short-lived intraplatform basin. Two soft-sediment deformation horizons (slump sheets) separated by undeformed limestones with similar facies occur in this part of the succession. The lower, thicker slump sheet (1.0-1.3 m thick) contains asymmetric and box folds. Well-developed décollement surfaces (locally containing thick brecciated zones) cut the folds, forming small-scale thrust-sheets and indicating mixed plastic to brittle behaviour. The upper, thinner slump sheet (0.25-0.35 m thick) contains only asymmetric folds, indicating plastic behaviour only. The differences in deformation style are attributed to differences in facies. Measurements of fold-axis orientations in the slump sheets show that they moved in similar directions, recording the development of a local, gently dipping palaeoslope. Autogenic (internal) trigger mechanisms are ruled out by a detailed consideration of facies. The slump sheets were triggered by allogenic, tectonic effects, either the weakening of sediment by seismic activity or the tectonically induced steepening of slopes

  12. Ultrahigh conductivity of large area suspended few layer graphene films

    Science.gov (United States)

    Rouhi, Nima; Wang, Yung Yu; Burke, Peter J.

    2012-12-01

    Room-temperature (atmospheric-pressure) electrical conductivity measurements of wafer-scale, large-area suspended (few layer) graphene membranes with areas up to 1000 μm2 (30 μm × 30 μm) are presented. Multiple devices on one wafer can be fabricated with high yield from the same chemical vapor deposition grown graphene sheet, transferred from a nickel growth substrate to large opening in a suspended silicon nitride support membrane. This represents areas two to orders of magnitude larger than prior transport studies on any suspended graphene device (single or few layer). We find a sheet conductivity of ˜2500 e2/h (or about 10 Ω/sq) of the suspended graphene, which is an order of magnitude higher than any previously reported sheet conductance of few layer graphene.

  13. Silicone metalization

    Science.gov (United States)

    Maghribi, Mariam N.; Krulevitch, Peter; Hamilton, Julie

    2008-12-09

    A system for providing metal features on silicone comprising providing a silicone layer on a matrix and providing a metal layer on the silicone layer. An electronic apparatus can be produced by the system. The electronic apparatus comprises a silicone body and metal features on the silicone body that provide an electronic device.

  14. Silicone metalization

    Science.gov (United States)

    Maghribi, Mariam N.; Krulevitch, Peter; Hamilton, Julie

    2006-12-05

    A system for providing metal features on silicone comprising providing a silicone layer on a matrix and providing a metal layer on the silicone layer. An electronic apparatus can be produced by the system. The electronic apparatus comprises a silicone body and metal features on the silicone body that provide an electronic device.

  15. Precision fabrication of large area silicon-based geometrically enhanced x-ray photocathodes using plasma etching

    Science.gov (United States)

    Opachich, Y. P.; Chen, N.; Bell, P. M.; Bradley, D. K.; Feng, J.; Gopal, A.; Hilsabeck, T. J.; Huffman, E.; Koch, J. A.; Landen, O. L.; MacPhee, A. G.; Nagel, S. R.; Udin, S.

    2015-08-01

    Geometrically enhanced photocathodes are currently being developed for use in applications that seek to improve detector efficiency in the visible to X-ray ranges. Various photocathode surface geometries are typically chosen based on the detector operational wavelength region, along with requirements such as spatial resolution, temporal resolution and dynamic range. Recently, a structure has been identified for possible use in the X-ray region. This anisotropic high aspect ratio structure has been produced in silicon using inductively coupled plasma (ICP) etching technology. The process is specifically developed with respect to the pattern density and geometry of the photocathode chip to achieve the desired sidewall profile angle. The tapered sidewall profile angle precision has been demonstrated to be within +/- 2.5° for a ~ 12° wall angle, with feature sizes that range between 4-9 μm in diameter and 10-25 μm depth. Here we discuss the device applications, design and present the method used to produce a set of geometrically enhanced high yield X-ray photocathodes in silicon.

  16. 3D silicon sensors: Design, large area production and quality assurance for the ATLAS IBL pixel detector upgrade

    International Nuclear Information System (INIS)

    3D silicon sensors, where electrodes penetrate the silicon substrate fully or partially, have successfully been fabricated in different processing facilities in Europe and USA. The key to 3D fabrication is the use of plasma micro-machining to etch narrow deep vertical openings allowing dopants to be diffused in and form electrodes of pin junctions. Similar openings can be used at the sensor's edge to reduce the perimeter's dead volume to as low as ∼4 μm. Since 2009 four industrial partners of the 3D ATLAS R and D Collaboration started a joint effort aimed at one common design and compatible processing strategy for the production of 3D sensors for the LHC Upgrade and in particular for the ATLAS pixel Insertable B-Layer (IBL). In this project, aimed for installation in 2013, a new layer will be inserted as close as 3.4 cm from the proton beams inside the existing pixel layers of the ATLAS experiment. The detector proximity to the interaction point will therefore require new radiation hard technologies for both sensors and front end electronics. The latter, called FE-I4, is processed at IBM and is the biggest front end of this kind ever designed with a surface of ∼4 cm2. The performance of 3D devices from several wafers was evaluated before and after bump-bonding. Key design aspects, device fabrication plans and quality assurance tests during the 3D sensors prototyping phase are discussed in this paper.

  17. Reply to comment by D. Nývlt on "Development of the topography-controlled Upper Odra ice lobe (Scandinavian Ice Sheet) in the fore-mountain area of southern Poland during the Saalian glaciation"

    Science.gov (United States)

    Salamon, Tomasz

    2016-02-01

    D. Nyvlt's comment provides an opportunity to re-discuss the problem of the maximum extent of the Scandinavian Ice Sheet during the Saalian glaciation in the area of the Moravian Gate, which has been a subject of debate for many years (Lewandowski, 1988; Badura and Przybylski, 1998). The controversies arise from different conclusions derived from studies in neighbouring areas of Poland and Czech Republic (Fig. 1a). In Poland, a generally accepted view is that the ice sheet reached its maximum extent during the Elsterian glaciation (Marks, 2004; Mojski, 2005), when it advanced up to the foothills of the Carpathian Mountains. During the Saalian glaciation it did not over-pass the Middle Polish Upland belt, but only through the Silesian Lowland slipped further southward, but not as far as the Czech authors suggest. They propose that the ice sheet advanced deeply into the Moravian Gate, crossed the main European water divide and its maximum extent was even larger than during Elsterian glaciation (Nývlt et al., 2011; Tyráček, 2011). A less extensive Saalian ice sheet was proposed by Lewandowski (1988), who claimed that the concept of deep penetration of the Moravian Gate by the ice lobe is in contradiction to data obtained from the area to the north of the Ostrava Basin, and especially from the Oświęcim Basin and the Rybnik Plateau (Fig. 1a). If the ice-sheet reached as far as the Czech authors claim, the mentioned areas should also have been glaciated (at least partially), however there is no evidence for this. Only a single (Elsterian) horizon of till is known from the Oświęcim Basin and the Rybnik Plateau (Karaś-Brzozowska, 1963; Klimek, 1972; Lewandowski, 1988; Haisig and Wilanowski, 2003). Sediments of Saalian age have been identified there, but these are only proglacial sands and silts (e.g. Lewandowski, 1988; Salamon, 2009). There is no evidence of the Saalian glaciation at the immediate foreland of the Beskidy Mountains to the east of the Ostrava Basin

  18. GASN sheets

    International Nuclear Information System (INIS)

    This document gathers around 50 detailed sheets which describe and present various aspects, data and information related to the nuclear sector or, more generally to energy. The following items are addressed: natural and artificial radioactive environment, evolution of energy needs in the world, radioactive wastes, which energy for France tomorrow, the consequences in France of the Chernobyl accident, ammunitions containing depleted uranium, processing and recycling of used nuclear fuel, transport of radioactive materials, seismic risk for the basic nuclear installations, radon, the precautionary principle, the issue of low doses, the EPR, the greenhouse effect, the Oklo nuclear reactors, ITER on the way towards fusion reactors, simulation and nuclear deterrence, crisis management in the nuclear field, does nuclear research put a break on the development of renewable energies by monopolizing funding, nuclear safety and security, the plutonium, generation IV reactors, comparison of different modes of electricity production, medical exposure to ionizing radiations, the control of nuclear activities, food preservation by ionization, photovoltaic solar collectors, the Polonium 210, the dismantling of nuclear installations, wind energy, desalination and nuclear reactors, from non-communication to transparency about nuclear safety, the Jules Horowitz reactor, CO2 capture and storage, hydrogen, solar energy, the radium, the subcontractors of maintenance of the nuclear fleet, biomass, internal radio-contamination, epidemiological studies, submarine nuclear propulsion, sea energy, the Three Mile Island accident, the Chernobyl accident, the Fukushima accident, the nuclear after Fukushima

  19. Large area multicrystalline silicon solar cells with high efficiency. Final report; Grossflaechige multikristalline Silizium-Solarzellen mit hohen Wirkungsraden. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Ebest, G.; Erler, K.; Mrwa, A.; Ball, M.

    2001-09-01

    Solar cells were produced of wafers of die-cast and strip-drawn multicrystalline silicon and characterized. Production methods like SOD (spin-on doping), RTP (rapid thermal processing), PECVD (plasma enhanced chemical vapor deposition), RIE (reactive ion etching) and screen printing were investigated. The results are summarized as follows: 1. Layer resistance can be adjusted by variation of the RTP temperature cycle and by selecting appropriate doping materials (P507 by Filmtronics); 2. The low resistance required for screen printing metallization are obtained only with a different doping material (P8545SF-Filmtronics); 3. Metallized aluminium and copper require a 30 nm TiN layer as diffusion barrier; 4. Reflectivity will be reduced most effectively by RIE with chlorine gas on monocrystalline and multicrystalline silicon wafers. [German] Im Rahmen des Projektes wurden auf Wafern aus blockgegossenem und bandgezogenem multikristallinen Silizium Solarzellen hergestellt und charakterisiert. Fuer die Herstellung wurden Verfahren wie SOD (spin-on doping), RTP (rapid thermal processing), PECVD (plasma enhanced chemical vapor deposition), RIE (reactive ion etching) und Siebdruck untersucht. Die Ergebnisse lassen sich wie folgt zusammenfassen: 1. eine Einstellung des Schichtwiderstandes wird durch Variation des RTP-Temperaturzyklus sowie Auswahl verschiedener Dotierstoffe (P507 von Filmtronics) erreicht; 2. die fuer die Siebdruckmetallisierung erforderlichen geringen Schichtwiderstaende werden nur durch die Wahl eines anderen Dotierstoffes (P8545SF-Filmtronics) erreicht; 3. Aluminium- und Kupfermetallisierungen benoetigen eine 30 nm dicke TiN-Schicht als Diffusionsbarriere; und 4. die wirksamste Verminderung des Reflexionsgrades ist mittels RIE-Verfahren unter Verwendung von Chlorgas auf ein- und multikristalline Siliziumwafer erreichbar.

  20. Performance of ultra-small silicon photomultiplier array with active area of 0.12 mm×0.12 mm

    International Nuclear Information System (INIS)

    We report the performance of an ultra-small silicon photomultiplier (SiPM) line array with 7 elements of 0.12×0.12 mm2 in active area, 0.2 mm in pitch and 120 micro cells in one element. The device features an epitaxial bulk quenching resistor concept, demonstrated high geometrical fill factor of 41% and photon detection efficiency (PDE) of 25.4% in the wavelength region between 430 nm and 480 nm while retaining high micro cell density around 10 000 mm−2 and ~3 ns FWHM of dark pulses width; it also demonstrated dark count rate of less than 28.7 kHz, optical crosstalk of the order of 2% to 4%, and excellent photon number discrimination. A 0.15 mm×1.6 mm×1.6 mm lutetium yttrium oxyorthosilicate (LYSO) crystal, corresponding to the width, length and height respectively, was successfully coupled to the 1×7 SiPM array for possible ultra-highly resolved positron emission tomography (PET) applications. This novel type of device has advantages particularly for small active area since the performances, such as PDE and response speed is one of the best among SiPMs with similarly high density of micro cells. It may pave a way for this type of SiPM as a promising pixel position sensitive device in imaging sensor applications. - Highlights: • The ultra-small SiPM line array with active area of 0.12 mm×0.12 mm was presented. • The ultra-small SiPM employs the bulk silicon structure as quenching resistor. • A considerable dynamic range and PDE over 25.4% @ 430 nm to 480 nm were characterized

  1. Performance of ultra-small silicon photomultiplier array with active area of 0.12 mm×0.12 mm

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Wang; Zongde, Chen; Chenhui, Li; Ran, He; Shenyuan, Wang; Baicheng, Li; Ruiheng, Wang; Kun, Liang, E-mail: lk@bnu.edu.cn; Ru, Yang; Dejun, Han

    2015-07-01

    We report the performance of an ultra-small silicon photomultiplier (SiPM) line array with 7 elements of 0.12×0.12 mm{sup 2} in active area, 0.2 mm in pitch and 120 micro cells in one element. The device features an epitaxial bulk quenching resistor concept, demonstrated high geometrical fill factor of 41% and photon detection efficiency (PDE) of 25.4% in the wavelength region between 430 nm and 480 nm while retaining high micro cell density around 10 000 mm{sup −2} and ~3 ns FWHM of dark pulses width; it also demonstrated dark count rate of less than 28.7 kHz, optical crosstalk of the order of 2% to 4%, and excellent photon number discrimination. A 0.15 mm×1.6 mm×1.6 mm lutetium yttrium oxyorthosilicate (LYSO) crystal, corresponding to the width, length and height respectively, was successfully coupled to the 1×7 SiPM array for possible ultra-highly resolved positron emission tomography (PET) applications. This novel type of device has advantages particularly for small active area since the performances, such as PDE and response speed is one of the best among SiPMs with similarly high density of micro cells. It may pave a way for this type of SiPM as a promising pixel position sensitive device in imaging sensor applications. - Highlights: • The ultra-small SiPM line array with active area of 0.12 mm×0.12 mm was presented. • The ultra-small SiPM employs the bulk silicon structure as quenching resistor. • A considerable dynamic range and PDE over 25.4% @ 430 nm to 480 nm were characterized.

  2. Recent progress in crystalline silicon solar cells

    International Nuclear Information System (INIS)

    In 1954, a solar cell was proposed for the first time that uses a Si pn-junction. The first and today still important application was as power generator for satellites in space. For this purpose, reliable, high performance, specially adapted and therefore expensive single crystal Si solar cells were developed. Since the beginning of the last decade, photovoltaics have been widely studied and developed as a new energy source for terrestrial use. So, research has been carried out from the point of view of materials, fabrication processes, structures and systems. First efforts aimed mainly at strong cost reductions. The results are the development of new low-cost and high-throughput cell fabrication technologies as screen-printing and the use of polycrystalline silicon as base material. However, progress in development of a new ''solar-grade'' silicon sheet material was slower and potential for cost reduction in module/system fabrication was smaller as expected originally. Consequently, since most silicon and module material costs are area-related, various tries to improve the efficiency have been undertaken. In this report, recent progress in the above mentioned topics will be reviewed. Besides this, some aspects of the module fabrication and performance will be discussed and some interesting applications presented. 89 refs, 33 figs, 2 tabs

  3. Thin sheets achieve optimal wrapping of liquids

    Science.gov (United States)

    Paulsen, Joseph; Démery, Vincent; Davidovitch, Benny; Santangelo, Christian; Russell, Thomas; Menon, Narayanan

    2015-03-01

    A liquid drop can wrap itself in a sheet using capillary forces [Py et al., PRL 98, 2007]. However, the efficiency of ``capillary origami'' at covering the surface of a drop is hampered by the mechanical cost of bending the sheet. Thinner sheets deform more readily by forming small-scale wrinkles and stress-focussing patterns, but it is unclear how coverage efficiency competes with mechanical cost as thickness is decreased, and what wrapping shapes will emerge. We place a thin (~ 100 nm) polymer film on a drop whose volume is gradually decreased so that the sheet covers an increasing fraction of its surface. The sheet exhibits a complex sequence of axisymmetric and polygonal partially- and fully- wrapped shapes. Remarkably, the progression appears independent of mechanical properties. The gross shape, which neglects small-scale features, is correctly predicted by a simple geometric approach wherein the exposed area is minimized. Thus, simply using a thin enough sheet results in maximal coverage.

  4. Front side electrode matching design and firing profiles for crystalline silicon solar cells with high sheet resistance%高方阻晶硅太阳能电池正面电极的匹配设计与烧结工艺

    Institute of Scientific and Technical Information of China (English)

    熊志军; 甘卫平; 周健; 罗林; 黎应芬

    2014-01-01

    采用液态磷源扩散法,通过控制扩散工艺条件制备具有不同方块电阻的多晶体硅片,并采用丝网印刷烧结技术制备晶体硅太阳能电池片,研究方块电阻、正面细栅线电极宽度、主栅类型以及烧结工艺对晶硅太阳能电池的光电转换性能的影响。结果表明,在方块电阻为80Ω/□,栅线宽度为60μm条件下,采用三主栅时,多晶硅太阳能电池片的短路电流、开路电压及填充因子均较高,光电转换效率最优,达到16.931%。通过优化烧结工艺,选择峰值烧结温度为800℃,带速为660 cm/min以及升温速率为65.7℃/s,细栅线电极的致密度高,光电转换效率达到17.207%。%Multicrystalline silicons with different sheet resistance were prepared using liquid phosphorus source diffusion method and controlling the process conditions. Crystalline silicon solar cells were made by screen printing and firing technology. The effects of sheet resistance, front side electrode gridline width, busbar design types and firing profiles on the photoelectric conversion performance parameters were investigated. The results show that, when the square sheet resistance is 80Ω/□and the gridline design width is 60μm under the condition of three busbars, the higher short circuit current, open circuit voltage and fill factors of crystalline silicon solar cells can be obtained, and the photoelectric conversion efficiency is the best reaching up to 16.931%. By optimizing the firing profiles, the density of fine gridline electrode is the high and the photoelectric conversion efficiency can be improved to 17.207% when the peak firing temperature is 800℃, the belt speed is 660 cm/min and heating rate is 65.7℃/s.

  5. Towards neuromorphic electronics: Memristors on foldable silicon fabric

    KAUST Repository

    Ghoneim, Mohamed T.

    2014-11-01

    The advantages associated with neuromorphic computation are rich areas of complex research. We address the fabrication challenge of building neuromorphic devices on structurally foldable platform with high integration density. We present a CMOS compatible fabrication process to demonstrate for the first time memristive devices fabricated on bulk monocrystalline silicon (100) which is next transformed into a flexible thin sheet of silicon fabric with all the pre-fabricated devices. This process preserves the ultra-high integration density advantage unachievable on other flexible substrates. In addition, the memristive devices are of the size of a motor neuron and the flexible/folded architectural form factor is critical to match brain cortex\\'s folded pattern for ultra-compact design.

  6. Cryostable lightweight frit bonded silicon mirror

    Science.gov (United States)

    Anthony, F.; McCarter, D.; Tangedahl, M.; Content, D.

    The excellent polishability, low density and relatively high stiffness of silicon make it an attractive candidate for optical applications that require superior performance. Assembly of silicon details by means of glass frit bonding permits significant light weighting thus enhancing the benefit of silicon mirrors. To demonstrate the performance potential, a small lightweight glass frit bonded silicon mirror was fabricated and tested for cryoability. The test mirror was 12.5cm in diameter with a 60cm spherical radius and a maximum thickness, at the perimeter, of 2.5cm. A machined silicon core was used to stiffen the two face sheets of the silicon sandwich. These three elements were assembled, by glass frit bonding, to form the substrate that was polished. The experimental evaluation in a liquid nitrogen cryostat, demonstrated cryostability performance significantly better than required by the mirror specification. Key WordsCryostable, Lightweight, Silicon, Frit Bond, Spherical, Mirror

  7. Roadmap on silicon photonics

    Science.gov (United States)

    Thomson, David; Zilkie, Aaron; Bowers, John E.; Komljenovic, Tin; Reed, Graham T.; Vivien, Laurent; Marris-Morini, Delphine; Cassan, Eric; Virot, Léopold; Fédéli, Jean-Marc; Hartmann, Jean-Michel; Schmid, Jens H.; Xu, Dan-Xia; Boeuf, Frédéric; O’Brien, Peter; Mashanovich, Goran Z.; Nedeljkovic, M.

    2016-07-01

    Silicon photonics research can be dated back to the 1980s. However, the previous decade has witnessed an explosive growth in the field. Silicon photonics is a disruptive technology that is poised to revolutionize a number of application areas, for example, data centers, high-performance computing and sensing. The key driving force behind silicon photonics is the ability to use CMOS-like fabrication resulting in high-volume production at low cost. This is a key enabling factor for bringing photonics to a range of technology areas where the costs of implementation using traditional photonic elements such as those used for the telecommunications industry would be prohibitive. Silicon does however have a number of shortcomings as a photonic material. In its basic form it is not an ideal material in which to produce light sources, optical modulators or photodetectors for example. A wealth of research effort from both academia and industry in recent years has fueled the demonstration of multiple solutions to these and other problems, and as time progresses new approaches are increasingly being conceived. It is clear that silicon photonics has a bright future. However, with a growing number of approaches available, what will the silicon photonic integrated circuit of the future look like? This roadmap on silicon photonics delves into the different technology and application areas of the field giving an insight into the state-of-the-art as well as current and future challenges faced by researchers worldwide. Contributions authored by experts from both industry and academia provide an overview and outlook for the silicon waveguide platform, optical sources, optical modulators, photodetectors, integration approaches, packaging, applications of silicon photonics and approaches required to satisfy applications at mid-infrared wavelengths. Advances in science and technology required to meet challenges faced by the field in each of these areas are also addressed together with

  8. Low-temperature silicon thin films for large-area electronics: Device fabrication using soft lithography and laser-crystallization by sequential lateral solidification

    Science.gov (United States)

    Jin, Hyun-Chul

    This work demonstrates possible routes for fabricating large-area electronic devices on glass or plastic substrates using low-temperature materials deposition and soft lithographic device patterning. Hydrogenated amorphous silicon (a-Si:H) and polycrystalline silicon (poly-Si) have been extensively studied as the semiconducting material for flat panel displays and solar cells. On glass substrates, we have deposited a-Si:H films at a temperature lower than 125°C, and we have used pulsed excimer laser crystallization in the sequential lateral solidification (SLS) regime to fabricate poly-Si films. We use micromolding in capillaries (MIMIC), a form of soft lithography involving micrometer-scale polymer molding, as a means to fabricate amorphous silicon thin-film transistors (TFTs), and photoconductive sensor arrays on both planar and curved substrates. The use of non-planar substrates has captured considerable attention in the field because it would open up new applications and new designs. Field-effect transistors made by SLS poly-Si show excellent mobility and on/off current ratio; however, the microstructure of the material had never been well documented. We determined the microtexture using electron backscattering diffraction (EBSD): the first crystallites formed in the a-Si layer are random; along the direction of the solidification, a strong in-plane orientation quickly develops due to competitive growth and occlusion. The misorientation angle between neighboring grains is also analyzed. A large fraction of the boundaries within the material are low-angle and coincidence site lattice (CSL) types. We discuss the implications of the findings on the defect generation mechanism and on the electrical properties of the films. We have analyzed the electrical properties of SLS poly-Si films on oxidized Si wafer using the pseudo-MOSFET geometry; the majority carrier mobility is extracted from the transconductance. However, the data are non-ideal due to large contact

  9. Surface micromachining of unfired ceramic sheets

    OpenAIRE

    Rheaume, Jonathan M.; Pisano, Albert P.

    2011-01-01

    Conventional surface micromachining techniques including photolithography and both wet and dry etching have been directly applied to an unfired sheet of yttria-stabilized zirconia ceramic material. Reversible bonding methods were investigated for affixing unfired ceramic samples to silicon handle wafers in order to perform photolithography. Three types of photoresist were investigated. Thin film photoresist allowed a line-width feature size of 8 μm to be obtained. Thick film photoresist exhib...

  10. Motorized actuation system to perform droplet operations on printed plastic sheets.

    Science.gov (United States)

    Kong, Taejoon; Brien, Riley; Njus, Zach; Kalwa, Upender; Pandey, Santosh

    2016-05-21

    We developed an open microfluidic system to dispense and manipulate discrete droplets on planar plastic sheets. Here, a superhydrophobic material is spray-coated on commercially-available plastic sheets followed by the printing of hydrophilic symbols using an inkjet printer. The patterned plastic sheets are taped to a two-axis tilting platform, powered by stepper motors, that provides mechanical agitation for droplet transport. We demonstrate the following droplet operations: transport of droplets of different sizes, parallel transport of multiple droplets, merging and mixing of multiple droplets, dispensing of smaller droplets from a large droplet or a fluid reservoir, and one-directional transport of droplets. As a proof-of-concept, a colorimetric assay is implemented to measure the glucose concentration in sheep serum. Compared to silicon-based digital microfluidic devices, we believe that the presented system is appealing for various biological experiments because of the ease of altering design layouts of hydrophilic symbols, relatively faster turnaround time in printing plastic sheets, larger area to accommodate more tests, and lower operational costs by using off-the-shelf products. PMID:27080172

  11. Development of large area nanostructured silicon-hydrogen alloy material with improved stability for solar cell application by argon dilution method

    Science.gov (United States)

    Dey, Arka; Das, Mrinmay; Datta, Joydeep; Jana, Rajkumar; Dhar, Joydeep; Sil, Sayantan; Biswas, Debasish; Banerjee, Chandan; Ray, Partha Pratim

    2016-07-01

    Here we have presented the results of large area (30 × 30 cm2) silicon-hydrogen alloy material and solar cell by argon dilution method. As an alternative to hydrogen dilution, argon dilution method has been applied to develop single junction solar cell with appreciable stability. Optimization of deposition conditions revealed that 95% argon dilution gives a nanostructured material with improved transport property and less light induced degradation. The minority carrier diffusion length (L d ) and mobility-lifetime (μτ) product of the material with 95% argon dilution degrades least after light soaking. Also the density of states (DOS) below conduction level reveals that this material is less defective. Solar cell with this argon diluted material has been fabricated with all the layers deposited by argon dilution method. Finally we have compared the argon diluted solar cell results with the optimized hydrogen diluted solar cell. Light soaking study proves that it is possible to develop stable solar cell on large area by argon dilution method and that the degradation of argon diluted solar cell is less than that of hydrogen diluted one. [Figure not available: see fulltext.

  12. Development of n{sup +}-in-p large-area silicon microstrip sensors for very high radiation environments – ATLAS12 design and initial results

    Energy Technology Data Exchange (ETDEWEB)

    Unno, Y., E-mail: yoshinobu.unno@kek.jp [Institute of Particle and Nuclear Study, KEK, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Edwards, S.O.; Pyatt, S.; Thomas, J.P.; Wilson, J.A. [School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT (United Kingdom); Kierstead, J.; Lynn, D. [Brookhaven National Laboratory, Physics Department and Instrumentation Division, Upton, NY 11973-5000 (United States); Carter, J.R.; Hommels, L.B.A.; Robinson, D. [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Bloch, I.; Gregor, I.M.; Tackmann, K. [Josef Stefan Institute and Department of Physics, University of Ljubljana, Ljubljana (Slovenia); Betancourt, C.; Jakobs, K.; Kuehn, S.; Mori, R.; Parzefall, U.; Wiik-Fucks, L. [Physikalisches Institut, Universitt Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Clark, A. [DPNC, University of Geneva, 24, Quai Ernest-Ansermet, CH-1211 Genve 4 (Switzerland); and others

    2014-11-21

    We have been developing a novel radiation-tolerant n{sup +}-in-p silicon microstrip sensor for very high radiation environments, aiming for application in the high luminosity large hadron collider. The sensors are fabricated in 6 in., p-type, float-zone wafers, where large-area strip sensor designs are laid out together with a number of miniature sensors. Radiation tolerance has been studied with ATLAS07 sensors and with independent structures. The ATLAS07 design was developed into new ATLAS12 designs. The ATLAS12A large-area sensor is made towards an axial strip sensor and the ATLAS12M towards a stereo strip sensor. New features to the ATLAS12 sensors are two dicing lines: standard edge space of 910 μm and slim edge space of 450 μm, a gated punch-through protection structure, and connection of orphan strips in a triangular corner of stereo strips. We report the design of the ATLAS12 layouts and initial measurements of the leakage current after dicing and the resistivity of the wafers.

  13. Development of n+-in-p large-area silicon microstrip sensors for very high radiation environments – ATLAS12 design and initial results

    International Nuclear Information System (INIS)

    We have been developing a novel radiation-tolerant n+-in-p silicon microstrip sensor for very high radiation environments, aiming for application in the high luminosity large hadron collider. The sensors are fabricated in 6 in., p-type, float-zone wafers, where large-area strip sensor designs are laid out together with a number of miniature sensors. Radiation tolerance has been studied with ATLAS07 sensors and with independent structures. The ATLAS07 design was developed into new ATLAS12 designs. The ATLAS12A large-area sensor is made towards an axial strip sensor and the ATLAS12M towards a stereo strip sensor. New features to the ATLAS12 sensors are two dicing lines: standard edge space of 910 μm and slim edge space of 450 μm, a gated punch-through protection structure, and connection of orphan strips in a triangular corner of stereo strips. We report the design of the ATLAS12 layouts and initial measurements of the leakage current after dicing and the resistivity of the wafers

  14. Respirator Fact Sheet

    Science.gov (United States)

    ... Products NIOSH-Issued Publications Publication Types Alerts Current Intelligence Bulletins Criteria Documents Fact Sheets Health Hazard Evaluations ( ... using gas mask and escape respirators. At the end of this Fact Sheet, you will find a ...

  15. Porous silicon gettering

    Energy Technology Data Exchange (ETDEWEB)

    Tsuo, Y.S.; Menna, P.; Pitts, J.R. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-05-01

    The authors have studied a novel extrinsic gettering method that uses the large surface areas produced by a porous-silicon etch as gettering sites. The annealing step of the gettering used a high-flux solar furnace. They found that a high density of photons during annealing enhanced the impurity diffusion to the gettering sites. The authors used metallurgical-grade Si (MG-Si) prepared by directional solidification casing as the starting material. They propose to use porous-silicon-gettered MG-Si as a low-cost epitaxial substrate for polycrystalline silicon thin-film growth.

  16. Silicon etch process

    International Nuclear Information System (INIS)

    A silicon etch process wherein an area of silicon crystal surface is passivated by radiation damage and non-planar structure produced by subsequent anisotropic etching. The surface may be passivated by exposure to an energetic particle flux - for example an ion beam from an arsenic, boron, phosphorus, silicon or hydrogen source, or an electron beam. Radiation damage may be used for pattern definition and/or as an etch stop. Ethylenediamine pyrocatechol or aqueous potassium hydroxide anisotropic etchants may be used. The radiation damage may be removed after etching by thermal annealing. (author)

  17. Silicon detectors

    International Nuclear Information System (INIS)

    The status and recent progress of silicon detectors for high energy physics is reviewed. Emphasis is put on detectors with high spatial resolution and the use of silicon detectors in calorimeters. (orig.)

  18. Study on Silicon detectors

    International Nuclear Information System (INIS)

    Prototypes of Silicon microstrip detectors and Silicon large area detectors (3x2 cm2), realized directly by our group, either by ion implantation or by diffusion are presented. The physical detector characteristics and their performances determined by exposing them to different radioactive sources and the results of extensive tests on passivation, where new technological ways have been investigated, are discussed. The calculation of the different terms contributing to the total dark current is reported

  19. Large area supersonic jet epitaxy of AlN, GaN, and SiC on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Lauhon, L.J.; Ustin, S.A.; Ho, W. [Cornell Univ., Ithaca, NY (United States). Dept. of Physics

    1997-12-31

    AlN, GaN, and SiC thin films were grown on 100 mm diameter Si(111) and Si(100) substrates using Supersonic Jet Epitaxy (SJE). Precursor gases were seeded in lighter mass carrier gases and free jets were formed using novel slit-jet apertures. The jet design, combined with substrate rotation, allowed for a uniform flux distribution over a large area of a 100 mm wafer at growth pressures of 1--20 mTorr. Triethylaluminum, triethylgallium, and ammonia were used for nitride growth, while disilane, acetylene, and methylsilane were used for SiC growth. The films were characterized by in situ optical reflectivity, x-ray diffraction (XRD), atomic force microscopy (AFM), and spectroscopic ellipsometry (SE).

  20. Systems Integration Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    This fact sheet is an overview of the Systems Integration subprogram at the U.S. Department of Energy SunShot Initiative. The Systems Integration subprogram enables the widespread deployment of safe, reliable, and cost-effective solar energy technologies by addressing the associated technical and non-technical challenges. These include timely and cost-effective interconnection procedures, optimal system planning, accurate prediction of solar resources, monitoring and control of solar power, maintaining grid reliability and stability, and many more. To address the challenges associated with interconnecting and integrating hundreds of gigawatts of solar power onto the electricity grid, the Systems Integration program funds research, development, and demonstration projects in four broad, interrelated focus areas: grid performance and reliability, dispatchability, power electronics, and communications.

  1. Cryostable lightweight frit-bonded silicon mirror

    Science.gov (United States)

    Anthony, Frank M.; McCarter, Douglas R.; Tangedahl, Matt; Content, David A.

    2002-11-01

    The excellent polishability, low density and relatively high stiffness of silicon make it an attractive candidate for optical applications that require superior performance. Assembly of silicon details by means of glass frit bonding permits significant weight reduction thus enhancing the benefit of silicon mirrors. To demonstrate the performance potential, a small lightweight glass frit bonded silicon mirror was fabricated and tested for cryostability. The test mirror was 12.5cm in diameter with a 60cm spherical radius and a maximum thickness, at the perimeter, of 2.5cm. A machined silicon core was used to stiffen the two face sheets of the silicon sandwich. These three elements were assembled, by glass frit bonding, to form the substrate that was polished. The experimental evaluation, in a liquid nitrogen cryostat, demonstrated cryostability performance significantly better than required by the mirror specification.

  2. High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling Stability

    Science.gov (United States)

    Krause, Andreas; Dörfler, Susanne; Piwko, Markus; Wisser, Florian M.; Jaumann, Tony; Ahrens, Eike; Giebeler, Lars; Althues, Holger; Schädlich, Stefan; Grothe, Julia; Jeffery, Andrea; Grube, Matthias; Brückner, Jan; Martin, Jan; Eckert, Jürgen; Kaskel, Stefan; Mikolajick, Thomas; Weber, Walter M.

    2016-01-01

    We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm2. The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D substrates. In contrast to metallic Li, the presented system exhibits superior characteristics as an anode in Li/S batteries such as safe operation, long cycle life and easy handling. These anodes are combined with high area density S/C composite cathodes into a Li/S full-cell with an ether- and lithium triflate-based electrolyte for high ionic conductivity. The result is a highly cyclable full-cell with an areal capacity of 2.3 mAh/cm2, a cyclability surpassing 450 cycles and capacity retention of 80% after 150 cycles (capacity loss <0.4% per cycle). A detailed physical and electrochemical investigation of the SiNW Li/S full-cell including in-operando synchrotron X-ray diffraction measurements reveals that the lower degradation is due to a lower self-reduction of polysulfides after continuous charging/discharging. PMID:27319783

  3. Evaluation of the bulk and strip characteristics of large area n-in-p silicon sensors intended for a very high radiation environment

    Science.gov (United States)

    Bohm, J.; Mikestikova, M.; Affolder, A. A.; Allport, P. P.; Bates, R.; Betancourt, C.; Brown, H.; Buttar, C.; Carter, J. R.; Casse, G.; Chen, H.; Chilingarov, A.; Cindro, V.; Clark, A.; Dawson, N.; Dewilde, B.; Doherty, F.; Dolezal, Z.; Eklund, L.; Fadeyev, V.; Ferrere, D.; Fox, H.; French, R.; Garcia, C.; Gerling, M.; Gonzalez Sevilla, S.; Gorelov, I.; Greenall, A.; Grillo, A. A.; Hara, K.; Hatano, H.; Hoeferkamp, M.; Hommels, L. B. A.; Ikegami, Y.; Jakobs, K.; Kierstead, J.; Kodys, P.; Köhler, M.; Kohriki, T.; Krambergen, G.; Lacasta, C.; Li, Z.; Lindgren, S.; Lynn, D.; Maddock, P.; Mandic, I.; Marti I Garcia, S.; Martinez-McKinney, F.; Maunu, R.; McCarthy, R.; Metcalfe, J.; Mikuz, M.; Minano, M.; Mitsui, S.; O'Shea, V.; Paganis, S.; Parzefall, U.; Puldon, D.; Robinson, D.; Sadrozinski, H. F.-W.; Sattari, S.; Schamberger, D.; Seidel, S.; Seiden, A.; Soldevila, U.; Terada, S.; Toms, K.; Tsionou, D.; Unno, Y.; von Wilpert, J.; Wormald, M.; Wright, J.; Yamada, M.

    2011-04-01

    The ATLAS collaboration R&D group “Development of n-in-p Silicon Sensors for very high radiation environment” has developed single-sided p-type 9.75 cm×9.75 cm sensors with an n-type readout strips having radiation tolerance against the 1015 1-MeV neutron equivalent (neq)/cm2 fluence expected in the Super Large Hadron Collider. The compiled results of an evaluation of the bulk and strip parameter characteristics of 19 new non-irradiated sensors manufactured by Hamamatsu Photonics are presented in this paper. It was verified in detail that the sensors comply with the technical specifications required before irradiation. The reverse bias voltage dependence of various parameters, frequency dependence of tested capacitances, and strip scans of more than 23,000 strips as a test of parameter uniformity and strip quality over the whole sensor area have been carried out at Stony Brook University, Cambridge University, University of Geneva, and Academy of Sciences of CR and Charles University in Prague. No openings, shorts, or pinholes were observed on all tested strips, confirming the high quality of sensors made by Hamamatsu Photonics.

  4. High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling Stability.

    Science.gov (United States)

    Krause, Andreas; Dörfler, Susanne; Piwko, Markus; Wisser, Florian M; Jaumann, Tony; Ahrens, Eike; Giebeler, Lars; Althues, Holger; Schädlich, Stefan; Grothe, Julia; Jeffery, Andrea; Grube, Matthias; Brückner, Jan; Martin, Jan; Eckert, Jürgen; Kaskel, Stefan; Mikolajick, Thomas; Weber, Walter M

    2016-01-01

    We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm(2). The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D substrates. In contrast to metallic Li, the presented system exhibits superior characteristics as an anode in Li/S batteries such as safe operation, long cycle life and easy handling. These anodes are combined with high area density S/C composite cathodes into a Li/S full-cell with an ether- and lithium triflate-based electrolyte for high ionic conductivity. The result is a highly cyclable full-cell with an areal capacity of 2.3 mAh/cm(2), a cyclability surpassing 450 cycles and capacity retention of 80% after 150 cycles (capacity loss <0.4% per cycle). A detailed physical and electrochemical investigation of the SiNW Li/S full-cell including in-operando synchrotron X-ray diffraction measurements reveals that the lower degradation is due to a lower self-reduction of polysulfides after continuous charging/discharging. PMID:27319783

  5. Crescimento de diamante CVD em substratos de silício de grande área CVD Diamond growth in the silicon substrates of large area

    Directory of Open Access Journals (Sweden)

    João Roberto Moro

    2010-06-01

    Full Text Available Realizaram-se crescimentos de filmes de diamante por deposição química de vapor (CVD, do inglês Chemical Vapor Deposition em substratos de silício (100, de grande área (80 cm², em um reator de filamento quente (HFCVD, com taxas de crescimento superiores a 1,5 µm/h. Foi realizado o crescimento das amostras com diferentes fluxos gasosos e diferentes porcentagens de metano (CH4 em hidrogênio (H2. As amostras foram caracterizadas por microscopia óptica, eletrônica de varredura e por espectroscopia de espalhamento Raman. Tais análises acusaram a presença de diamante de alta pureza em todas as amostras.Diamond films were grown through Chemical Vapor Deposition (CVD in silicon substrates (100 of large area (80 cm², in a hot filament chemical vapor deposition (HFCVD, with growth rates over 1,5 µm/h. The growth of samples was made with different gaseous fluxes and different methane percentages (CH4 in hydrogen (H2. The samples were analyzed through optical microscopy, Scanning Electron Microscopy and Raman spectroscopy scattering. Such analyzes showed the presence of a high purity diamond in all samples.

  6. Impact of carrier recombination on fill factor for large area heterojunction crystalline silicon solar cell with 25.1% efficiency

    Science.gov (United States)

    Adachi, Daisuke; Hernández, José Luis; Yamamoto, Kenji

    2015-12-01

    We have achieved a certified 25.1% conversion efficiency in a large area (151.9 cm2) heterojunction (HJ) crystalline Si (c-Si) solar cell with amorphous Si (a-Si) passivation layer. This efficiency is a world record in a both-side-contacted c-Si solar cell. Our high efficiency HJ c-Si solar cells are investigated from the standpoint of the effective minority carrier lifetime (τe), and the impact of τe on fill factor (FF) is discussed. The τe measurements of our high efficiency HJ c-Si solar cells reveal that τe at an injection level corresponding to an operation point of maximum power is dominated by the carrier recombination at the a-Si/c-Si interface. By optimization of the process conditions, the carrier recombination at the a-Si/c-Si interface is reduced, which leads to an improvement of the FF by an absolute value of 2.7%, and a conversion efficiency of 25.1% has been achieved. These results indicate that the reduction of carrier recombination centers at the a-Si/c-Si interface should be one of the most crucial issues for further improvement of FF even in the HJ c-Si solar cells with efficiency over 25%.

  7. Transformational silicon electronics

    KAUST Repository

    Rojas, Jhonathan Prieto

    2014-02-25

    In today\\'s traditional electronics such as in computers or in mobile phones, billions of high-performance, ultra-low-power devices are neatly integrated in extremely compact areas on rigid and brittle but low-cost bulk monocrystalline silicon (100) wafers. Ninety percent of global electronics are made up of silicon. Therefore, we have developed a generic low-cost regenerative batch fabrication process to transform such wafers full of devices into thin (5 μm), mechanically flexible, optically semitransparent silicon fabric with devices, then recycling the remaining wafer to generate multiple silicon fabric with chips and devices, ensuring low-cost and optimal utilization of the whole substrate. We show monocrystalline, amorphous, and polycrystalline silicon and silicon dioxide fabric, all from low-cost bulk silicon (100) wafers with the semiconductor industry\\'s most advanced high-κ/metal gate stack based high-performance, ultra-low-power capacitors, field effect transistors, energy harvesters, and storage to emphasize the effectiveness and versatility of this process to transform traditional electronics into flexible and semitransparent ones for multipurpose applications. © 2014 American Chemical Society.

  8. Balance of the West Antarctic Ice Sheet

    Science.gov (United States)

    2002-01-01

    For several decades, measurements of the West Antarctic Ice Sheet showed it to be retreating rapidly. But new data derived from satellite-borne radar sensors show the ice sheet to be growing. Changing Antarctic ice sheets remains an area of high scientific interest, particularly in light of recent global warming concerns. These new findings are significant because scientists estimate that sea level would rise 5-6 meters (16-20 feet) if the ice sheet collapsed into the sea. Do these new measurements signal the end of the ice sheet's 10,000-year retreat? Or, are these new satellite data simply much more accurate than the sparse ice core and surface measurements that produced the previous estimates? Another possibility is that the ice accumulation may simply indicate that the ice sheet naturally expands and retreats in regular cycles. Cryologists will grapple with these questions, and many others, as they examine the new data. The image above depicts the region of West Antarctica where scientists measured ice speed. The fast-moving central ice streams are shown in red. Slower tributaries feeding the ice streams are shown in blue. Green areas depict slow-moving, stable areas. Thick black lines depict the areas that collect snowfall to feed their respective ice streams. Reference: Ian Joughin and Slawek Tulaczyk Science Jan 18 2002: 476-480. Image courtesy RADARSAT Antarctic Mapping Project

  9. ERRATA SHEET for Post-Closure Inspection Report for Corrective Action Unit 407: Roller Coaster RadSafe Area Tonopah Test Range, Nevada, Calendar year 2001; TOPICAL

    International Nuclear Information System (INIS)

    The fifth sentence of the first paragraph on Page 1 of the Post Closure Inspection Report for Corrective Action Unit 407: Roller Coaster RadSafe Area, Tonopah Test Range, Nevada erroneously states that Revision 1 of the CR was issued in December of 2001 and was approved by NDEP on January 7, 2002. The sentence should state that Revision 1 of the CR was issued in December of 2001 and was approved by NDEP on February 22, 2002

  10. Large-area, wafer-scale epitaxial growth of germanium on silicon and integration of high-performance transistors

    Science.gov (United States)

    Ghosh, Swapnadip

    Building on a unique two-step, simple MBE growth technique, we have investigated possible dislocation locking mechanisms by dopant impurities, coupled with artificially introduced oxygen. In the case of n-type Ge grown on Si, our materials characterization indicates that the dislocation density (DD) can reach the ˜105 cm-2 level, compared to p-type and undoped Ge on Si (GoS). We note that our Ge film covers the entire underlying Si substrate at the wafer scale without mesas or limited-area growth. In this presentation, we will focus on the use of n-type impurity (phosphorus) diffusing from the Si substrate and the introduction of O at the Ge-Si interface. The O is introduced by growing a thin chemical SiO2 layer on top of the Si substrate before Ge epitaxy begins. Z-contrast cross-sectional TEM images suggest the presence of oxygen precipitates in n-type Ge, whereas these precipitates appear absent in p-type Ge. These oxygen precipitates are known to lock the dislocations. Supporting the argument of precipitate formation, the TEM shows fringes due to various phase boundaries that exist at the precipitate/Ge-crystal interface. We speculate that the formation of phosphorus (P) segregation resulting from slow diffusion of P through precipitates at the precipitate/Ge-crystal interface facilitates dislocation locking. Impurity segregations in turn suppress O concentration in n-type Ge indicating reduced magnitude of DD that appears on the top surface of n-Ge compared to p-Ge film. The O concentrations (1017 to 1018 cm-3) in the n- and p-type GoS films are measured using secondary ionization mass spectroscopy. We also demonstrate the technique to improve the Ge epitaxial quality by inserting air-gapped, SiO2-based nanoscale templates within epitaxially grown Ge on Si. We have shown that the template simultaneously filters threading dislocations propagating from Ge-Si interface and relieves the film stress caused by the TEC mismatch. The finite element modeling stress

  11. Comment on "Development of the topography-controlled Upper Odra ice lobe (Scandinavian ice sheet) in the fore-mountain area of southern Poland during the Saalian glaciation" by T. Salamon [Quat. Sci. Rev. 123 (2015) 1-15

    Science.gov (United States)

    Nývlt, Daniel

    2016-02-01

    Salamon (2015) presented a glaciodynamic model of the evolution of the Upper Odra ice lobe of the Northern European Ice Sheet during the Saalian (Drenthe) glaciation. This is timely and welcomed paper, as it brings a dynamic conceptual model and emphasizes the topographic control of the ice sheet behaviour, which was very important for Middle Pleistocene ice sheet advances in Central European sector (e.g.; Nývlt, 2008; Nývlt et al., 2011).

  12. Diffusive Silicon Nanopore Membranes for Hemodialysis Applications.

    Directory of Open Access Journals (Sweden)

    Steven Kim

    Full Text Available Hemodialysis using hollow-fiber membranes provides life-sustaining treatment for nearly 2 million patients worldwide with end stage renal disease (ESRD. However, patients on hemodialysis have worse long-term outcomes compared to kidney transplant or other chronic illnesses. Additionally, the underlying membrane technology of polymer hollow-fiber membranes has not fundamentally changed in over four decades. Therefore, we have proposed a fundamentally different approach using microelectromechanical systems (MEMS fabrication techniques to create thin-flat sheets of silicon-based membranes for implantable or portable hemodialysis applications. The silicon nanopore membranes (SNM have biomimetic slit-pore geometry and uniform pores size distribution that allow for exceptional permeability and selectivity. A quantitative diffusion model identified structural limits to diffusive solute transport and motivated a new microfabrication technique to create SNM with enhanced diffusive transport. We performed in vitro testing and extracorporeal testing in pigs on prototype membranes with an effective surface area of 2.52 cm2 and 2.02 cm2, respectively. The diffusive clearance was a two-fold improvement in with the new microfabrication technique and was consistent with our mathematical model. These results establish the feasibility of using SNM for hemodialysis applications with additional scale-up.

  13. Diffusive Silicon Nanopore Membranes for Hemodialysis Applications.

    Science.gov (United States)

    Kim, Steven; Feinberg, Benjamin; Kant, Rishi; Chui, Benjamin; Goldman, Ken; Park, Jaehyun; Moses, Willieford; Blaha, Charles; Iqbal, Zohora; Chow, Clarence; Wright, Nathan; Fissell, William H; Zydney, Andrew; Roy, Shuvo

    2016-01-01

    Hemodialysis using hollow-fiber membranes provides life-sustaining treatment for nearly 2 million patients worldwide with end stage renal disease (ESRD). However, patients on hemodialysis have worse long-term outcomes compared to kidney transplant or other chronic illnesses. Additionally, the underlying membrane technology of polymer hollow-fiber membranes has not fundamentally changed in over four decades. Therefore, we have proposed a fundamentally different approach using microelectromechanical systems (MEMS) fabrication techniques to create thin-flat sheets of silicon-based membranes for implantable or portable hemodialysis applications. The silicon nanopore membranes (SNM) have biomimetic slit-pore geometry and uniform pores size distribution that allow for exceptional permeability and selectivity. A quantitative diffusion model identified structural limits to diffusive solute transport and motivated a new microfabrication technique to create SNM with enhanced diffusive transport. We performed in vitro testing and extracorporeal testing in pigs on prototype membranes with an effective surface area of 2.52 cm2 and 2.02 cm2, respectively. The diffusive clearance was a two-fold improvement in with the new microfabrication technique and was consistent with our mathematical model. These results establish the feasibility of using SNM for hemodialysis applications with additional scale-up. PMID:27438878

  14. Diffusive Silicon Nanopore Membranes for Hemodialysis Applications

    Science.gov (United States)

    Kim, Steven; Feinberg, Benjamin; Kant, Rishi; Chui, Benjamin; Goldman, Ken; Park, Jaehyun; Moses, Willieford; Blaha, Charles; Iqbal, Zohora; Chow, Clarence; Wright, Nathan; Fissell, William H.; Zydney, Andrew; Roy, Shuvo

    2016-01-01

    Hemodialysis using hollow-fiber membranes provides life-sustaining treatment for nearly 2 million patients worldwide with end stage renal disease (ESRD). However, patients on hemodialysis have worse long-term outcomes compared to kidney transplant or other chronic illnesses. Additionally, the underlying membrane technology of polymer hollow-fiber membranes has not fundamentally changed in over four decades. Therefore, we have proposed a fundamentally different approach using microelectromechanical systems (MEMS) fabrication techniques to create thin-flat sheets of silicon-based membranes for implantable or portable hemodialysis applications. The silicon nanopore membranes (SNM) have biomimetic slit-pore geometry and uniform pores size distribution that allow for exceptional permeability and selectivity. A quantitative diffusion model identified structural limits to diffusive solute transport and motivated a new microfabrication technique to create SNM with enhanced diffusive transport. We performed in vitro testing and extracorporeal testing in pigs on prototype membranes with an effective surface area of 2.52 cm2 and 2.02 cm2, respectively. The diffusive clearance was a two-fold improvement in with the new microfabrication technique and was consistent with our mathematical model. These results establish the feasibility of using SNM for hemodialysis applications with additional scale-up. PMID:27438878

  15. Corrective Action Decision Document/Closure Report for Corrective Action Unit 309: Area 12 Muckpiles, Nevada Test Site, Nevada, Rev. No.: 0 with Errata Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Alfred Wickline

    2005-12-01

    This Corrective Action Decision Document/Closure Report (CADD/CR) has been prepared for Corrective Action Unit (CAU) 309, Area 12 Muckpiles, Nevada Test Site (NTS), Nevada. The corrective actions proposed in this document are according to the ''Federal Facility Agreement and Consent Order'' (FFACO) that was agreed to by the State of Nevada, U.S. Department of Energy (DOE), and the U.S. Department of Defense (FFACO, 1996). The NTS is approximately 65 miles (mi) northwest of Las Vegas, Nevada (Figure 1-1). Corrective Action Unit 309 is comprised of the three Corrective Action Sites (CASs) (Figure 1-1) listed below: (1) CAS 12-06-09, Muckpile; (2) CAS 12-08-02, Contaminated Waste Dump (CWD); and (3) CAS 12-28-01, I-, J-, and K-Tunnel Debris. Corrective Action Sites 12-06-09 and 12-08-02 will be collectively referred to as muckpiles in this document. Corrective Action Site 12-28-01 will be referred to as the fallout plume because of the extensive lateral area of debris and fallout contamination resulting from the containment failures of the J- and K-Tunnels. A detailed discussion of the history of this CAU is presented in the ''Corrective Action Investigation Plan (CAIP) for Corrective Action Unit 309: Area 12 Muckpiles, Nevada Test Site (NTS), Nevada.'' (NNSA/NSO, 2004). This CADD/CR provides justification for the closure of CAU 309 without further corrective action. This justification is based on process knowledge and the results of the investigative activities conducted according to the CAIP (NNSA/NSO, 2004), which provides information relating to the history, planning, and scope of the investigation. Therefore, this information will not be repeated in this CADD/CR.

  16. High-efficiency screen-printed solar cell on edge-defined film-fed grown ribbon silicon through optimized rapid belt co-firing of contacts and high-sheet-resistance emitter

    Science.gov (United States)

    Rohatgi, Ajeet; Hilali, Mohamed M.; Nakayashiki, Kenta

    2004-04-01

    High-quality screen-printed contacts were achieved on a high-sheet-resistance emitter (˜100 Ω/sq.) using PV168 Ag paste and rapid co-firing in the belt furnace. The optimized co-firing cycle developed for a 100 Ω/sq. emitter produced 16.1% efficient 4 cm2 planar edge-defined film-fed grown (EFG) ribbon Si cells with a low series-resistance (0.8 Ω cm2), high fill factor of ˜0.77, along with very significant bulk lifetime enhancement from 3 to 100 μs. This represents the highest-efficiency screen-printed EFG Si cells with single-layer antireflection (AR) coating. These cells were fabricated using a simple process involving POCl3 diffusion for a high-sheet-resistance emitter, SiNx AR coating and rapid cofiring of Ag grid and Al-doped back-surface field in a conventional belt furnace. The rapid cofiring process also prevented junction shunting while maintaining very effective SiNx-induced hydrogen passivation of defects, resulting in an average bulk lifetime exceeding 100 μs.

  17. Development of Tandem Amorphous/Microcrystalline Silicon Thin-Film Large-Area See-Through Color Solar Panels with Reflective Layer and 4-Step Laser Scribing for Building-Integrated Photovoltaic Applications

    OpenAIRE

    Chin-Yi Tsai; Chin-Yao Tsai

    2014-01-01

    In this work, tandem amorphous/microcrystalline silicon thin-film large-area see-through color solar modules were successfully designed and developed for building-integrated photovoltaic applications. Novel and key technologies of reflective layers and 4-step laser scribing were researched, developed, and introduced into the production line to produce solar panels with various colors, such as purple, dark blue, light blue, silver, golden, orange, red wine, and coffee. The highest module power...

  18. Perforating Thin Metal Sheets

    Science.gov (United States)

    Davidson, M. E.

    1985-01-01

    Sheets only few mils thick bonded together, punched, then debonded. Three-step process yields perforated sheets of metal. (1): Individual sheets bonded together to form laminate. (2): laminate perforated in desired geometric pattern. (3): After baking, laminate separates into individual sheets. Developed for fabricating conductive layer on blankets that collect and remove ions; however, perforated foils have other applications - as conductive surfaces on insulating materials; stiffeners and conductors in plastic laminates; reflectors in antenna dishes; supports for thermal blankets; lightweight grille cover materials; and material for mockup of components.

  19. VEGA: A low-power front-end ASIC for large area multi-linear X-ray silicon drift detectors: Design and experimental characterization

    International Nuclear Information System (INIS)

    We present the design and the first experimental characterization of VEGA, an Application Specific Integrated Circuit (ASIC) designed to read out large area monolithic linear Silicon Drift Detectors (SDD’s). VEGA consists of an analog and a digital/mixed-signal section to accomplish all the functionalities and specifications required for high resolution X-ray spectroscopy in the energy range between 500 eV and 50 keV. The analog section includes a charge sensitive preamplifier, a shaper with 3-bit digitally selectable shaping times from 1.6 µs to 6.6 µs and a peak stretcher/sample-and-hold stage. The digital/mixed-signal section includes an amplitude discriminator with coarse and fine threshold level setting, a peak discriminator and a logic circuit to fulfill pile-up rejection, signal sampling, trigger generation, channel reset and the preamplifier and discriminators disabling functionalities. A Serial Peripherical Interface (SPI) is integrated in VEGA for loading and storing all configuration parameters in an internal register within few microseconds. The VEGA ASIC has been designed and manufactured in 0.35 µm CMOS mixed-signal technology in single and 32 channel versions with dimensions of 200 µm×500 µm per channel. A minimum intrinsic Equivalent Noise Charge (ENC) of 12 electrons r.m.s. at 3.6 µs peaking time and room temperature is measured and the linearity error is between −0.9% and +0.6% in the whole input energy range. The total power consumption is 481 µW and 420 µW per channel for the single and 32 channels version, respectively. A comparison with other ASICs for X-ray SDD’s shows that VEGA has a suitable low noise and offers high functionality as ADC-ready signal processing but at a power consumption that is a factor of four lower than other similar existing ASICs

  20. Ag2CrO4 nanoparticles loaded on two-dimensional large surface area graphite-like carbon nitride sheets: simple synthesis and excellent photocatalytic performance.

    Science.gov (United States)

    Shi, Lei; Liang, Lin; Wang, Fangxiao; Liu, Mengshuai; Sun, Jianmin

    2016-04-01

    Graphite-like carbon nitride (g-C3N4) with a large surface area was prepared through thermal condensation of guanidine hydrochloride at 650 °C. Various amounts of silver chromate (Ag2CrO4) nanoparticles with small size were highly loaded on the g-C3N4 by a simple co-precipitation method at room temperature. The chemical constituents, surface structure and optical properties of the resultant Ag2CrO4/g-C3N4 composites were thoroughly characterized. And the photocatalytic performances were evaluated by degradation of Rhodamine B (RhB) and phenol, the experimental results indicated that the as-prepared Ag2CrO4/g-C3N4 composites presented excellent photocatalytic activity under visible-light irradiation. With the mass ratio of Ag2CrO4 to g-C3N4 at 1 : 2, the Ag2CrO4/g-C3N4 composites exhibited optimal photocatalytic activity for degrading RhB, approximately 6.1 and 10.4 times higher than those on pure g-C3N4 and bare Ag2CrO4 particles. The improved photocatalytic activity was mainly attributed to the combined effect including the larger surface area, highly dispersed smaller Ag2CrO4 nanoparticles, stronger visible absorption and higher charge separation efficiency of the Ag2CrO4/g-C3N4 composites. Moreover, the possible mechanism for the photocatalytic activity was tentatively proposed. PMID:26937621

  1. CMS Silicon Strip Tracker Monitoring

    CERN Document Server

    Mersi, Stefano

    2010-01-01

    The CMS Silicon Strip Tracker is the largest detector of its kind ever operated, with a silicon surface area of about 200 m$^2$ of silicon surface. The Silicon Strip Tracker it is the sub-detector with the highest number of detector modules within the CMS experiment. Given the complexity of the device, a variety of tools were developed and are used to determine the status of the detector in real time and allow for data qualification and corrective actions when needed. In this paper we describe the monitoring techniques that are used to safely operate the detector and assess the state of its calibration.

  2. Single crystalline mesoporous silicon nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Hochbaum, Allon; Dargas, Daniel; Hwang, Yun Jeong; Yang, Peidong

    2009-08-18

    Herein we demonstrate a novel electroless etching synthesis of monolithic, single-crystalline, mesoporous silicon nanowire arrays with a high surface area and luminescent properties consistent with conventional porous silicon materials. The photoluminescence of these nanowires suggest they are composed of crystalline silicon with small enough dimensions such that these arrays may be useful as photocatalytic substrates or active components of nanoscale optoelectronic devices. A better understanding of this electroless route to mesoporous silicon could lead to facile and general syntheses of different narrow bandgap semiconductor nanostructures for various applications.

  3. Corrective Action Decision Document for Corrective Action Unit 168: Area 25 and 26 Contaminated Materials and Waste Dumps, Nevada Test Site, Nevada, Rev. No.: 2 with Errata Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Wickline, Alfred

    2006-12-01

    This Corrective Action Decision Document has been prepared for Corrective Action Unit (CAU) 168: Area 25 and 26, Contaminated Materials and Waste Dumps, Nevada Test Site, Nevada. The purpose of this Corrective Action Decision Document is to identify and provide a rationale for the selection of a recommended corrective action alternative for each corrective action site (CAS) within CAU 168. The corrective action investigation (CAI) was conducted in accordance with the ''Corrective Action Investigation Plan for Corrective Action Unit 168: Area 25 and 26, Contaminated Materials and Waste Dumps, Nevada Test Site, Nevada'', as developed under the ''Federal Facility Agreement and Consent Order'' (1996). Corrective Action Unit 168 is located in Areas 25 and 26 of the Nevada Test Site, Nevada and is comprised of the following 12 CASs: CAS 25-16-01, Construction Waste Pile; CAS 25-16-03, MX Construction Landfill; CAS 25-19-02, Waste Disposal Site; CAS 25-23-02, Radioactive Storage RR Cars; CAS 25-23-13, ETL - Lab Radioactive Contamination; CAS 25-23-18, Radioactive Material Storage; CAS 25-34-01, NRDS Contaminated Bunker; CAS 25-34-02, NRDS Contaminated Bunker; CAS 25-99-16, USW G3; CAS 26-08-01, Waste Dump/Burn Pit; CAS 26-17-01, Pluto Waste Holding Area; and CAS 26-19-02, Contaminated Waste Dump No.2. Analytes detected during the CAI were evaluated against preliminary action levels (PALs) to determine contaminants of concern (COCs) for CASs within CAU 168. Radiological measurements of railroad cars and test equipment were compared to unrestricted (free) release criteria. Assessment of the data generated from the CAI activities revealed the following: (1) Corrective Action Site 25-16-01 contains hydrocarbon-contaminated soil at concentrations exceeding the PAL. The contamination is at discrete locations associated with asphalt debris. (2) No COCs were identified at CAS 25-16-03. Buried construction waste is present in at least two

  4. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 117: Area 26 Pluto Disassembly Facility, Nevada Test Site, Nevada With Errata Sheets, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Pat Matthews

    2007-09-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions needed to achieve closure for Corrective Action Unit (CAU) 117, Pluto Disassembly Facility, identified in the Federal Facility Agreement and Consent Order. Corrective Action Unit 117 consists of one Corrective Action Site (CAS), CAS 26-41-01, located in Area 26 of the Nevada Test Site. This plan provides the methodology for field activities needed to gather the necessary information for closing CAS 26-41-01. There is sufficient information and process knowledge from historical documentation and investigations of similar sites regarding the expected nature and extent of potential contaminants to recommend closure of CAU 117 using the SAFER process. Additional information will be obtained by conducting a field investigation before finalizing the appropriate corrective action for this CAS. The results of the field investigation will support a defensible recommendation that no further corrective action is necessary following SAFER activities. This will be presented in a Closure Report that will be prepared and submitted to the Nevada Division of Environmental Protection (NDEP) for review and approval. The site will be investigated to meet the data quality objectives (DQOs) developed on June 27, 2007, by representatives of NDEP; U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office; Stoller-Navarro Joint Venture; and National Security Technologies, LLC. The DQO process was used to identify and define the type, amount, and quality of data needed to determine and implement appropriate corrective actions for CAS 26-41-01 in CAU 117.

  5. Infertility Fact Sheet

    Science.gov (United States)

    ... Home > ePublications > Our ePublications > Infertility fact sheet ePublications Infertility fact sheet This information in Spanish (en español) ... to the fallopian tube instead of the uterus. Gamete intrafallopian transfer (GIFT) involves transferring eggs and sperm into the ...

  6. Ice sheet in peril

    DEFF Research Database (Denmark)

    Hvidberg, Christine Schøtt

    2016-01-01

    Earth's large ice sheets in Greenland and Antarctica are major contributors to sea level change. At present, the Greenland Ice Sheet (see the photo) is losing mass in response to climate warming in Greenland (1), but the present changes also include a long-term response to past climate transitions...

  7. Simulations of the Scandinavian ice sheet and its subsurface conditions

    Energy Technology Data Exchange (ETDEWEB)

    Boulton, G.S.; Caban, P.; Hulton, N. [Edinburgh Univ. (United Kingdom). Dept of Geology and Geophysics

    1999-12-01

    An ice sheet model has been applied to an approximate flow line through the area of the Fennoscandian ice sheet. The modelled ice sheet fluctuations have been matched with stratigraphic evidence of Weichselian ice sheet fluctuation in order to simulate ice sheet attributes through time along the flowline. The model predicts extensive melting at the base of the ice sheet. This output has been used as an input to a simplified model of hydrogeology along the southern flank of the ice sheet so as to reconstruct patterns of subglacial groundwater flow. The output from the model is also used to estimate patterns of subglacial stress and strain. Results suggest that large scale subglacial groundwater catchment are formed which were quite differentin extent from modern catchment; that fossil subglacial groundwaters should be found at sampling depths; and much fracturing in shallow bedrock in Sweden could be glacially generated.

  8. Simulations of the Scandinavian ice sheet and its subsurface conditions

    International Nuclear Information System (INIS)

    An ice sheet model has been applied to an approximate flow line through the area of the Fennoscandian ice sheet. The modelled ice sheet fluctuations have been matched with stratigraphic evidence of Weichselian ice sheet fluctuation in order to simulate ice sheet attributes through time along the flowline. The model predicts extensive melting at the base of the ice sheet. This output has been used as an input to a simplified model of hydrogeology along the southern flank of the ice sheet so as to reconstruct patterns of subglacial groundwater flow. The output from the model is also used to estimate patterns of subglacial stress and strain. Results suggest that large scale subglacial groundwater catchment are formed which were quite different in extent from modern catchment; that fossil subglacial groundwaters should be found at sampling depths; and much fracturing in shallow bedrock in Sweden could be glacially generated

  9. Cell sheet engineering

    Directory of Open Access Journals (Sweden)

    Masayuki Yamato

    2004-05-01

    Full Text Available We have developed ‘cell sheet engineering’ in order to avoid the limitations of tissue reconstruction using biodegradable scaffolds or single cell suspension injection. Our concept is tissue reconstruction, not from single cells, but from cell sheets. Cell sheets are prepared using temperature-responsive culture dishes. Temperature-responsive polymers are covalently grafted onto the dishes, allowing various types of cells to adhere and proliferate at 37°C. The cells spontaneously detach when the temperature is reduced below 32°C without the need for proteolytic enzymes. The confluent cells are noninvasively harvested as single, contiguous cell sheets with intact cell-cell junctions and deposited extracellular matrix (ECM. We have used these harvested cell sheets for various tissue reconstructions, including ocular surfaces, periodontal ligaments, cardiac patches, and bladder augmentation.

  10. Corrective Action Decision Document/Corrective Action Plan for Corrective Action Unit 447: Project Shoal Area, Subsurface, Nevada, Rev. No.: 3 with Errata Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Tim Echelard

    2006-03-01

    This Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) has been prepared for Corrective Action Unit (CAU) 447, Project Shoal Area (PSA)-Subsurface, Nevada, in accordance with the ''Federal Facility Agreement and Consent Order'' (FFACO) (1996). Corrective Action Unit 447 is located in the Sand Springs Mountains in Churchill County, Nevada, approximately 48 kilometers (30 miles) southeast of Fallon, Nevada. The CADD/CAP combines the decision document (CADD) with the Corrective Action Plan (CAP) and provides or references the specific information necessary to recommend corrective actions for CAU 447, as provided in the FFACO. Corrective Action Unit 447 consists of two corrective action sites (CASs): CAS 57-49-01, Emplacement Shaft, and CAS 57-57-001, Cavity. The emplacement shaft (CAS-57-49-01) was backfilled and plugged in 1996 and will not be evaluated further. The purpose of the CADD portion of the document (Section 1.0 to Section 4.0) is to identify and provide a rationale for the selection of a recommended corrective action alternative for the subsurface at PSA. To achieve this, the following tasks were required: (1) Develop corrective action objectives. (2) Identify corrective action alternative screening criteria. (3) Develop corrective action alternatives. (4) Perform detailed and comparative evaluations of the corrective action alternatives in relation to the corrective action objectives and screening criteria. (5) Recommend a preferred corrective action alternative for the subsurface at PSA. The original Corrective Action Investigation Plan (CAIP) for the PSA was approved in September 1996 and described a plan to drill and test four characterization wells, followed by flow and transport modeling (DOE/NV, 1996). The resultant drilling is described in a data report (DOE/NV, 1998e) and the data analysis and modeling in an interim modeling report (Pohll et al., 1998). After considering the results of the modeling effort

  11. Greenland Ice Sheet Retreat Since the Little Ice Age

    OpenAIRE

    Beitch, Marci Jillian

    2014-01-01

    Late 20th century and 21st century satellite imagery of the perimeter of the Greenland Ice Sheet (GrIS) provide high resolution observations of the ice sheet margins. Examining changes in ice margin positions over time yield measurements of GrIS area change and rates of margin retreat. However, longer records of ice sheet margin change are needed to establish more accurate predictions of the ice sheet's future response to global conditions. In this study, the trimzone, the area of deglaciated...

  12. Ice sheet hydrology from observations

    International Nuclear Information System (INIS)

    possible that soft beds through their ability to deform and be eroded can yield quasi-stable patterns of drainage pathways that with either erosion of critical sills or filling of temporary basins may reorganize itself periodically on time scales much shorter than the reorganization of the driving stresses for ice flow. In areas where the surface generated water (melt and rain), the basally generated fluxes dwarf the influx from the surface and hence the drainage system in such areas will be dominated by surface fluxes and variations therein. Since surface fluxes have a strong seasonal variation with no influx during winter, areas experiencing surface influx will also be subject to large seasonal variations in both flux and pressure. In addition, during the melt season, fluxes and also pressures will also vary on diurnal as well as longer time frames in response to variations in air temperature that drives melt and occurrence of precipitation events. The emerging picture of glacier drainage consists of different types of models applicable to different regimes found beneath an ice sheet (with our without surface influx, ice streams, subglacial lakes). It is not, however, clear how these systems are coupled, or even if they are. This makes it inherently difficult to assess what can be expected beneath a given sector of an ice sheet without some detailed understanding of the underlying geology (geothermal fluxes), geomorphology (possible water routing) and ice properties (cold -temperate base and ice thickness)

  13. Ice sheet hydrology from observations

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Peter (Dept. of Physical Geography and Quaternary Geology, Stockholm Univ-, Stockholm (Sweden))

    2010-11-15

    possible that soft beds through their ability to deform and be eroded can yield quasi-stable patterns of drainage pathways that with either erosion of critical sills or filling of temporary basins may reorganize itself periodically on time scales much shorter than the reorganization of the driving stresses for ice flow. In areas where the surface generated water (melt and rain), the basally generated fluxes dwarf the influx from the surface and hence the drainage system in such areas will be dominated by surface fluxes and variations therein. Since surface fluxes have a strong seasonal variation with no influx during winter, areas experiencing surface influx will also be subject to large seasonal variations in both flux and pressure. In addition, during the melt season, fluxes and also pressures will also vary on diurnal as well as longer time frames in response to variations in air temperature that drives melt and occurrence of precipitation events. The emerging picture of glacier drainage consists of different types of models applicable to different regimes found beneath an ice sheet (with our without surface influx, ice streams, subglacial lakes). It is not, however, clear how these systems are coupled, or even if they are. This makes it inherently difficult to assess what can be expected beneath a given sector of an ice sheet without some detailed understanding of the underlying geology (geothermal fluxes), geomorphology (possible water routing) and ice properties (cold -temperate base and ice thickness)

  14. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): Silicon Dioxide Coating Deposited by PDPs on PET Films and Influence on Oxygen Transmission Rate

    Science.gov (United States)

    Sun, Yun-Jin; Fu, Ya-Bo; Chen, Qiang; Zhang, Chun-Mei; Sang, Li-Jun; Zhang, Yue-Fei

    2008-05-01

    A silicon dioxide film is deposited on the polyethyleneterephtalate (PET) by a penning discharge plasma source at ambient temperature in a high vacuum chamber. Hexamethyldisiloxane and oxygen are adopted as precursor and reactive reagent to grow a nano-scale silicon dioxide layer on polymer surfaces. For the chemical structure analysis x-ray photoelectron spectroscopy is performed to demonstrate the content of Si, O and C elements. It is noticed that a higher silicon concentration is contained if Ar plasma is used for pretreatment. X-ray diffraction analysis shows that a micro-crystal silicon dioxide is formed by peak patterns at 25.84° and 21.8°. The barrier properties examined by oxygen transmission rate show that the permeation parameter of the 12-μm-thick PET film drastically decreases from 135cc/m2 per day for the control one to 0.713cc/m2 per day for the as-deposited one after Ar plasma treatment. The surface morphology related to the barrier properties of SiOx-coated polymers os also investigated by scanning electron microscopy and atomic force microscopy.

  15. Development of n.sup.+./sup.-in-p large-area silicon microstrip sensors for very high radiation environments – ATLAS12 design and initial results

    Czech Academy of Sciences Publication Activity Database

    Unno, Y.; Edwards, S.O.; Pyatt, S.; Böhm, Jan; Mikeštíková, Marcela

    2014-01-01

    Roč. 765, Nov (2014), s. 80-90. ISSN 0168-9002 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : silicon strip * n + -in-p * P-type * Radiation-tolerant * HL-LHC * PTP Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.216, year: 2014

  16. Magnesium, Silicon and Calcium Isotopes in Central European Tektites — Implications for High-Temperature Processes and Tracking Their Sources with the Ries Area Sediments

    Czech Academy of Sciences Publication Activity Database

    Magna, T.; Farkaš, J.; Rodovská, Z.; Trubač, J.; Georg, R. B.; Holmden, C.; Žák, Karel

    Houston : Lunar and Planetary Institute, 2015. [Lunar and Planetary Science Conference /46./. 16.03.2015-20.03.2015, Woodlands] R&D Projects: GA ČR GA13-22351S Institutional support: RVO:67985831 Keywords : tektites * magnesium * silicon * calcium * isotopes Subject RIV: DB - Geology ; Mineralogy http://www.hou.usra.edu/meetings/lpsc2015/pdf/2207.pdf

  17. Algebra task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 3-5, our State Standards-based combined resource meets the algebraic concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are opportunities for problem-solving, patterning, algebraic graphing, equations and determining averages. The combined task & drill sheets

  18. Algebra task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 6-8, our State Standards-based combined resource meets the algebraic concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are opportunities for problem-solving, patterning, algebraic graphing, equations and determining averages. The combined task & drill sheets

  19. Flexible high-κ/Metal gate metal/insulator/metal capacitors on silicon (100) fabric

    KAUST Repository

    Rojas, Jhonathan Prieto

    2013-10-01

    Implementation of memory on bendable substrates is an important step toward a complete and fully developed notion of mechanically flexible computational systems. In this paper, we have demonstrated a simple fabrication flow to build metal-insulator-metal capacitors, key components of dynamic random access memory, on a mechanically flexible silicon (100) fabric. We rely on standard microfabrication processes to release a thin sheet of bendable silicon (area: 18 {\\ m cm}2 and thickness: 25 \\\\mu{\\ m m}) in an inexpensive and reliable way. On such platform, we fabricated and characterized the devices showing mechanical robustness (minimum bending radius of 10 mm at an applied strain of 83.33% and nominal strain of 0.125%) and consistent electrical behavior regardless of the applied mechanical stress. Furthermore, and for the first time, we performed a reliability study suggesting no significant difference in performance and showing an improvement in lifetime projections. © 1963-2012 IEEE.

  20. Porous silicon carbide (SIC) semiconductor device

    Science.gov (United States)

    Shor, Joseph S. (Inventor); Kurtz, Anthony D. (Inventor)

    1996-01-01

    Porous silicon carbide is fabricated according to techniques which result in a significant portion of nanocrystallites within the material in a sub 10 nanometer regime. There is described techniques for passivating porous silicon carbide which result in the fabrication of optoelectronic devices which exhibit brighter blue luminescence and exhibit improved qualities. Based on certain of the techniques described porous silicon carbide is used as a sacrificial layer for the patterning of silicon carbide. Porous silicon carbide is then removed from the bulk substrate by oxidation and other methods. The techniques described employ a two-step process which is used to pattern bulk silicon carbide where selected areas of the wafer are then made porous and then the porous layer is subsequently removed. The process to form porous silicon carbide exhibits dopant selectivity and a two-step etching procedure is implemented for silicon carbide multilayers.

  1. HRSA Data Fact Sheets

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Health Resources and Services Administration (HRSA) Data Fact Sheets provide summary data about HRSA’s activities in each Congressional District, County, State,...

  2. Polarised light sheet tomography.

    Science.gov (United States)

    Reidt, Sascha L; O'Brien, Daniel J; Wood, Kenneth; MacDonald, Michael P

    2016-05-16

    The various benefits of light sheet microscopy have made it a widely used modality for capturing three-dimensional images. It is mostly used for fluorescence imaging, but recently another technique called light sheet tomography solely relying on scattering was presented. The method was successfully applied to imaging of plant roots in transparent soil, but is limited when it comes to more turbid samples. This study presents a polarised light sheet tomography system and its advantages when imaging in highly scattering turbid media. The experimental configuration is guided by Monte Carlo radiation transfer methods, which model the propagation of a polarised light sheet in the sample. Images of both reflecting and absorbing phantoms in a complex collagenous matrix were acquired, and the results for different polarisation configurations are compared. Focus scanning methods were then used to reduce noise and produce three-dimensional reconstructions of absorbing targets. PMID:27409945

  3. Global ice sheet modeling

    International Nuclear Information System (INIS)

    The University of Maine conducted this study for Pacific Northwest Laboratory (PNL) as part of a global climate modeling task for site characterization of the potential nuclear waste respository site at Yucca Mountain, NV. The purpose of the study was to develop a global ice sheet dynamics model that will forecast the three-dimensional configuration of global ice sheets for specific climate change scenarios. The objective of the third (final) year of the work was to produce ice sheet data for glaciation scenarios covering the next 100,000 years. This was accomplished using both the map-plane and flowband solutions of our time-dependent, finite-element gridpoint model. The theory and equations used to develop the ice sheet models are presented. Three future scenarios were simulated by the model and results are discussed

  4. Ovarian Cancer Fact Sheet

    Science.gov (United States)

    ... widgets/current/fahc.html/ Search Share Embed Ovarian cancer fact sheet Ovarian cancer is cancer that begins in the ovaries. ... make female hormones and produce a woman's eggs. Ovarian cancer is a serious cancer that is more ...

  5. Biodiesel Basics (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-06-01

    This fact sheet provides a brief introduction to biodiesel, including a discussion of biodiesel blends, which blends are best for which vehicles, where to buy biodiesel, how biodiesel compares to diesel fuel in terms of performance, how biodiesel performs in cold weather, whether biodiesel use will plug vehicle filters, how long-term biodiesel use may affect engines, biodiesel fuel standards, and whether biodiesel burns cleaner than diesel fuel. The fact sheet also dismisses the use of vegetable oil as a motor fuel.

  6. Are Graphene Sheets Stable?

    OpenAIRE

    Garcia, N.

    2007-01-01

    The answer to the title question is yes and the sheets exhibit diffraction peaks but may not have long range crystalline order. This is not a trivial question and answer and is immersing in the very active field now days of the study of properties of graphite and specially of graphene. This note is motivated in fact by a recent paper by Meyer et al (1) on the structure of suspended graphene sheets.

  7. Energy information sheets

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the public. The Energy Information Sheets was developed to provide general information on various aspects of fuel production, prices, consumption, and capability. Additional information on related subject matter can be found in other Energy Information Administration (EIA) publications as referenced at the end of each sheet.

  8. Integration of an amorphous silicon passive pixel sensor array with a lateral amorphous selenium detector for large area indirect conversion x-ray imaging applications

    Science.gov (United States)

    Wang, Kai; Yazdandoost, Mohammad Y.; Keshavarzi, Rasoul; Shin, Kyung-Wook; Hristovski, Christos; Abbaszadeh, Shiva; Chen, Feng; Majid, Shaikh Hasibul; Karim, Karim S.

    2011-03-01

    Previously, we reported on a single-pixel detector based on a lateral a-Se metal-semiconductor-metal structure, intended for indirect conversion X-ray imaging. This work is the continuous effort leading to the first prototype of an indirect conversion X-ray imaging sensor array utilizing lateral amorphous selenium. To replace a structurally-sophisticated vertical multilayer amorphous silicon photodiode, a lateral a-Se MSM photodetector is employed which can be easily integrated with an amorphous silicon thin film transistor passive pixel sensor array. In this work, both 2×2 macro-pixel and 32×32 micro-pixel arrays were fabricated and tested along with discussion of the results.

  9. Evaluation of the bulk and strip characteristics of large area n-in-p silicon sensors intended for a very high radiation environment

    Czech Academy of Sciences Publication Activity Database

    Böhm, Jan; Mikeštíková, Marcela; Affolder, A.A.; Allport, P.P.; Bates, R.; Betancourt, C.; Brown, H.; Buttar, C.; Carter, J. R.; Casse, G.

    2011-01-01

    Roč. 636, č. 1 (2011), "S104"-"S110". ISSN 0168-9002 R&D Projects: GA MŠk LA08032 Institutional research plan: CEZ:AV0Z10100502 Keywords : silicon * micro-strip * ATLAS ID upgrade * SLHC * leakage current * depletion voltage * electrical characteristics * coupling capacitance Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.207, year: 2011 http://dx.doi.org/10.1016/j.nima.2010.04.093

  10. Large-Area Crystalline Silicon Solar Cell Using Novel Antireflective Nanoabsorber Texturing Surface by Multihollow Cathode Plasma System and Spin-On Doping

    OpenAIRE

    Utpal Gangopadhyay; Sukhendu Jana; Sayan Das

    2013-01-01

    We present 11.7% efficient p-type crystalline silicon solar cells with a nanoscale textured surface and no dielectric antireflection coating. We propose nanocrystalline-like textured surface consisting of nanocrystalline columnar structures of diameters from 50 to 100 nm and depth of about 500 nm formed by reactive-ion etching (RIE) in multihollow cathode system. This novel nano textured surface acts as an antireflective absorbing surface of c-Si abbreviate as ARNAB (antireflective nanoabsorb...

  11. Development of Tandem Amorphous/Microcrystalline Silicon Thin-Film Large-Area See-Through Color Solar Panels with Reflective Layer and 4-Step Laser Scribing for Building-Integrated Photovoltaic Applications

    Directory of Open Access Journals (Sweden)

    Chin-Yi Tsai

    2014-01-01

    Full Text Available In this work, tandem amorphous/microcrystalline silicon thin-film large-area see-through color solar modules were successfully designed and developed for building-integrated photovoltaic applications. Novel and key technologies of reflective layers and 4-step laser scribing were researched, developed, and introduced into the production line to produce solar panels with various colors, such as purple, dark blue, light blue, silver, golden, orange, red wine, and coffee. The highest module power is 105 W and the highest visible light transmittance is near 20%.

  12. Robot automated EMPT sheet welding

    OpenAIRE

    Pasquale, Pablo; Schäfer, Ralph

    2012-01-01

    Many industrial applications require sheet to sheet or sheet to tube joints. The electromagnetic pulse technology is capable to produce these kinds of joints. In literature many examples of sheet to sheet solid state welding between similar and dissimilar metals are presented and analyzed in detail. However, the most of the presented welding applications, which are very focussed on the academic level, are simple specimens for example for tensile test. These specimens are usuall...

  13. Material Properties of Laser-Welded Thin Silicon Foils

    OpenAIRE

    Brabec, C.J.; Auer, R.; A. Bochmann; Christiansen, S.; Schmidt, M.; K. Cvecek; Voigt, M.; Hessmann, M. T.; Kunz, T.

    2013-01-01

    An extended monocrystalline silicon base foil offers a great opportunity to combine low-cost production with high efficiency silicon solar cells on a large scale. By overcoming the area restriction of ingot-based monocrystalline silicon wafer production, costs could be decreased to thin film solar cell range. The extended monocrystalline silicon base foil consists of several individual thin silicon wafers which are welded together. A comparison of three different approaches to weld 50 μm thin...

  14. Silicon ingot casting - heat exchanger method multi-wire slicing - fixed abrasive slicing technique, Phase III. Silicon sheet growth development for the large area sheet task of the Low-Cost Solar Array Project. Quarterly progress report No. 3, April 1-June 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, F.; Khattak, C.P.

    1979-07-01

    Ingot casting has been scaled up to 16 cm x 16 cm square cross-section size weighing up to 8.1 kg. The high degree of crystallinity has been maintained in the large ingot. For large sizes, the non-uniformity of heat treatment causes chipping of the surface of the ingot. Significant effort and progress have been made in the development of a uniform graded structure in the silica crucibles. The high speed slicer has been modified so that the blade-head weight is reduced to 37 lb. This has allowed higher surface speeds of up to 500 fpm. Slicing of 10 cm diameter workpieces at these speeds has increased the throughput of the machine to 5.7 mils/min, 0.145 mm/min, 50% more than the projected cutting rates used in the economic analysis.

  15. Electrochemical depth profiling of multilayer metallic structures: An aluminum brazing sheet

    DEFF Research Database (Denmark)

    Afshar, F. Norouzi; Ambat, R.; Kwakernaak, C.;

    2012-01-01

    Combinatory localized electrochemical cell and glow discharge optical emission spectrometry (GDOES) measurements were performed to obtain a thorough in depth electrochemical characterization of an aluminum brazing sheet. By defining electrochemical criteria i.e. breakdown potential, corrosion...... potential, cathodic and anodic reactivities, and tracking their changes as a function of depth, the evolution of electrochemical responses through out the material thickness were analyzed and correlated to the corresponding microstructural features. Polarization curves in 1wt% NaCl solution at pH 2.8 were...... susceptible to localized attack. Consistent with this, optical microscopy and scanning electron microscope analysis revealed a relatively high density of fine intermetallic and silicon particles at these areas. The corrosion mechanism of the top layers was identified to be intergranular and pitting corrosion...

  16. Evidence of meltwater retention within the Greenland ice sheet

    Directory of Open Access Journals (Sweden)

    A. K. Rennermalm

    2013-09-01

    Full Text Available Greenland ice sheet mass losses have increased in recent decades with more than half of these attributed to surface meltwater runoff. However, the magnitudes of englacial storage, firn retention, internal refreezing and other hydrologic processes that delay or reduce true water export to the global ocean remain less understood, partly due to a scarcity of in situ measurements. Here, ice sheet surface meltwater runoff and proglacial river discharge between 2008 and 2010 near Kangerlussuaq, southwestern Greenland were used to establish sub- and englacial meltwater storage for a small ice sheet watershed (36–64 km2. This watershed lacks significant potential meltwater storage in firn, surface lakes on the ice sheet and in the proglacial area, and receives limited proglacial precipitation. Thus, ice sheet surface runoff not accounted for by river discharge can reasonably be attributed to retention in sub- and englacial storage. Evidence for meltwater storage within the ice sheet includes (1 characteristic dampened daily river discharge amplitudes relative to ice sheet runoff; (2 three cold-season river discharge anomalies at times with limited ice sheet surface melt, demonstrating that meltwater may be retained up to 1–6 months; (3 annual ice sheet watershed runoff is not balanced by river discharge, and while near water budget closure is possible as much as 54% of melting season ice sheet runoff may not escape to downstream rivers; (4 even the large meltwater retention estimate (54% is equivalent to less than 1% of the ice sheet volume, which suggests that storage in en- and subglacial cavities and till is plausible. While this study is the first to provide evidence for meltwater retention and delayed release within the Greenland ice sheet, more information is needed to establish how widespread this is along the Greenland ice sheet perimeter.

  17. Single crystalline mesoporous silicon nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Hochbaum, A.I.; Gargas, Daniel; Jeong Hwang, Yun; Yang, Peidong

    2009-08-04

    Herein we demonstrate a novel electroless etching synthesis of monolithic, single-crystalline, mesoporous silicon nanowire arrays with a high surface area and luminescent properties consistent with conventional porous silicon materials. These porous nanowires also retain the crystallographic orientation of the wafer from which they are etched. Electron microscopy and diffraction confirm their single-crystallinity and reveal the silicon surrounding the pores is as thin as several nanometers. Confocal fluorescence microscopy showed that the photoluminescence (PL) of these arrays emanate from the nanowires themselves, and their PL spectrum suggests that these arrays may be useful as photocatalytic substrates or active components of nanoscale optoelectronic devices.

  18. Development of large-area monolithically integrated silicon-film{trademark} photovoltaic modules. Final subcontract report, May 1, 1991--December 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R.B.; Rand, J.A.; Cotter, J.E. [AstroPower, Inc., Newark, DE (United States)

    1995-04-01

    The objective of this program is to develop Silicon Film{trademark} Product III into a low-cost, stable solar cell for large-scale terrestrial power applications. The Product III structure is a thin (<100 {mu}m) polycrystalline layer of silicon on a durable, insulating, ceramic substrate. The insulating substrate allows the silicon layer to be isolated and metallized to form a monolithically interconnected array of solar cells. High efficiency is achieved by the use of light trapping and passivated surfaces. This project focused on the development of five key technologies associated with the monolithic sub-module device structure: (1) development of the film deposition and growth processes; (2) development of the low-cost ceramic substrate; (3) development of a metallurgical barrier technology; (4) development of sub-element solar cell processing techniques; and (5) development of sub-module (isolation and interconnection) processes. This report covers the development approaches and results relating to these technologies. Significant progress has been made in the development of all of the related technologies. This is evidenced by the fabrication of a working 12.0 cm{sup 2} prototype sub-module consisting of 7 elements and testing with an open circuit voltage of 3.9 volts, a short circuit current of 35.2 mA and a fill factor of 63% and an overall efficiency of 7.3%. Another significant result achieved is a 13.4% (NREL verified), 1.0 cm{sup 2} solar cell fabricated from material deposited and grown on a graphite cloth substrate. The significant technological hurdle of the program was and remains the low quality of the photovoltaic layer which is caused by contamination of the photovoltaic layer from the low-cost ceramic substrate by trace impurities found in the substrate precursor materials. The ceramic substrate and metallurgical barrier are being developed specifically to solve this problem.

  19. High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling Stability

    OpenAIRE

    Andreas Krause; Susanne Dörfler; Markus Piwko; Florian M. Wisser; Tony Jaumann; Eike Ahrens; Lars Giebeler; Holger Althues; Stefan Schädlich; Julia Grothe; Andrea Jeffery; Matthias Grube; Jan Brückner; Jan Martin; Jürgen Eckert

    2016-01-01

    We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm2. The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D su...

  20. Research into Pressed Behaviors of Fe 73. 5 Cu 1 Nb 3 Si 13. 5 B 9 Alloy Powder/Silicone Rubber Composite Sheets%Fe73.5 Cu1 Nb3 Si13.5 B9合金粉/硅橡胶复合材料薄片的压缩行为研究

    Institute of Scientific and Technical Information of China (English)

    尹益辉; 吴菊英; 王沪毅; 高洋

    2016-01-01

    Fe73. 5 Cu1 Nb3 Si13. 5 B9 alloy powder / silicone rubber piezomagnetic composite is a newly developed sensors material for measurement of contact stresses between some special interfaces. In order to make sensitive el-ements of sensors from this material,it is necessary to understand the mechanical behaviors of such composite sheets. The pressure stress - strain properties of piezomagnetic sensitive material samples with different layer num-ber of sheets were researched by experiments and FEM simulations. It is indicated that the pressure stress - strain curve of a sample has a quasi linear segment and it is of certain length and small nonlinearity,the curvature of the approximate linear segment of stress - strain curve of a single layer sample decreases with its thickness increasing, that of a multi layers sample with sheets of same thickness quantity degree decreases with layer number increasing, and that of a sample with a certain thickness and different layer number increases with layer number increasing. The result is useful for design,calibration and application of interlayer pressure sensors.%Fe73.5 Cu1 Nb3 Si13.5 B9合金粉/硅橡胶压磁复合材料是针对特种界面接触压力测量研发的新型传感材料,为了将该种材料的薄片作为传感器敏感元,需要认识薄片的力学行为.本文对该种压磁复合材料单层薄片试样和多层薄片重叠组合试样进行压缩实验和有限元数值模拟,获得了不同试样的压缩应力-应变曲线.通过对这些曲线的分析、比较,获得了如下认识:薄片的单向压缩应力-应变曲线存在近似线性段,且近似线性段具有一定的长度和足够弱的非线性程度;单层试样应力-应变曲线的近似线性段的斜率随厚度增大而减小;由厚度量级相同的若干单层重叠组成的试样,层数越多,则近似线性段的斜率越小;总厚度相同但层数不同的试样,层数越多,则近似线性段的斜

  1. Energy information sheets

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-02

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the general public. Written for the general public, the EIA publication Energy Information Sheets was developed to provide information on various aspects of fuel production, prices, consumption and capability. The information contained herein pertains to energy data as of December 1991. Additional information on related subject matter can be found in other EIA publications as referenced at the end of each sheet.

  2. General overview of sheet incremental forming

    Directory of Open Access Journals (Sweden)

    M. Tisza

    2012-11-01

    Full Text Available Purpose: The aim of this research paper is to give a general overview on sheet incremental forming as an emerging field in small and batch production.Design/methodology/approach: First the historical and literature background of sheet incremental forming will be given, and then some theoretical and practical issues of the incremental forming processes will be described including the research work done by the author at the University of Miskolc. This research is part of an international EUREKA project with the main focus on formability and accuracy in incremental sheet forming.Findings: In this research paper some important findings on the critical wall angle which is a characteristic formability feature in incremental sheet forming will be discussed. New specimen geometry was elaborated to reduce the great amount of experimental work to determine the formability limits. The main conclusions are that in incremental forming the formability is significantly higher compared to conventional sheet forming. The process is very flexible and economic due to the low tool costs.Research limitations/implications: One of the main target areas of further research work is the determination of technological window for sheet incremental forming of various materials and to introduce this novel process into industrial practice.Practical implications: In practical applications besides the economy of the process due to its very low tool expenses, the flexibility should be mentioned which is very important in small batch production and particularly in rapid prototyping.Originality/value: The results achieved within this research work are equally important both from the point of view of theoretical and practical aspects of sheet incremental forming.

  3. The LHCb silicon tracker

    CERN Document Server

    Adeva, B; Bauer, C; Baumeister, D; Bay, A; Bernhard, R P; Bernet, R; Blouw, J; Carron, B; Ermoline, Y; Esperante-Pereira, D; Frei, R; Gassner, J; Hofmann, W; Jiménez-Otero, S; Knöpfle, K T; Köstner, S; Lehner, F; Löchner, S; Lois, C; Needham, M; Pugatch, V; Schmelling, M; Schwingenheuer, B; Siegler, M; Steinkamp, O; Straumann, U; Tran, M T; Vázquez, P; Vollhardt, A; Volyanskyy, D; Voss, H

    2005-01-01

    LHCb is a dedicated B-physics and CP-violation experiment for the Large Hadron Collider at CERN. Efficient track reconstruction and excellent trigger performances are essential in order to exploit fully its physics potential. Silicon strip detectors providing fast signal generation, high resolution and fine granularity are used for this purpose in the large area Trigger Tracker station in front of the spectrometer magnet and the LHCb Inner Tracker covering the area close to the beam pipe behind the magnet. Long read-out strips of up to 38cm are used together with fast signal shaping adapted to the 25ns LHC bunch crossing. The design of these tracking stations, the silicon sensor strip geometries and the latest test results are presented here.

  4. Pseudomonas - Fact Sheet

    OpenAIRE

    Public Health Agency

    2012-01-01

    Fact sheet on Pseudomonas, including:What is Pseudomonas?What infections does it cause?Who is susceptible to pseudomonas infection?How will I know if I have pseudomonas infection?How can Pseudomonas be prevented from spreading?How can I protect myself from Pseudomonas?How is Pseudomonas infection treated?

  5. Fact Sheet on Stress

    Science.gov (United States)

    ... items) NIMH (7 items) Share Fact Sheet on Stress Download PDF Download ePub Q&A on Stress for Adults: How it affects your health and ... to avoid more serious health effects. What is stress? Stress can be defined as the brain's response ...

  6. Ethanol Basics (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2015-01-01

    Ethanol is a widely-used, domestically-produced renewable fuel made from corn and other plant materials. More than 96% of gasoline sold in the United States contains ethanol. Learn more about this alternative fuel in the Ethanol Basics Fact Sheet, produced by the U.S. Department of Energy's Clean Cities program.

  7. CSS - Cascading Style Sheets

    OpenAIRE

    Martinelli, Massimo

    2009-01-01

    Curso "CSS - Cascading Style Sheets" sobre programación web con CSS para el "Máster doble competencia en ciencias informáticas y ciencias sociales" ("Master double competence in computer science and social science"). Proyecto TEMPUS JEP – 26235-2005

  8. Silicon nanotube field effect transistor with core-shell gate stacks for enhanced high-performance operation and area scaling benefits

    KAUST Repository

    Fahad, Hossain M.

    2011-10-12

    We introduce the concept of a silicon nanotube field effect transistor whose unique core-shell gate stacks help achieve full volume inversion by giving a surge in minority carrier concentration in the near vicinity of the ultrathin channel and at the same time rapid roll-off at the source and drain junctions constituting velocity saturation-induced higher drive current-enhanced high performance per device with efficient real estate consumption. The core-shell gate stacks also provide superior short channel effects control than classical planar metal oxide semiconductor field effect transistor (MOSFET) and gate-all-around nanowire FET. The proposed device offers the true potential to be an ideal blend for quantum ballistic transport study of device property control by bottom-up approach and high-density integration compatibility using top-down state-of-the-art complementary metal oxide semiconductor flow. © 2011 American Chemical Society.

  9. A Printable Silicon Nano-Field Effect Transistor with High Operating Frequency for Large-Area Deployable Active Phased-Array Antennas Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Flexible electronic circuits can be easily integrated with large area (>10m aperture), inflatable antennas to provide distributed control and processing...

  10. Synchronization of flexible sheets

    CERN Document Server

    Elfring, Gwynn J; 10.1017/S0022112011000814

    2011-01-01

    When swimming in close proximity, some microorganisms such as spermatozoa synchronize their flagella. Previous work on swimming sheets showed that such synchronization requires a geometrical asymmetry in the flagellar waveforms. Here we inquire about a physical mechanism responsible for such symmetry-breaking in nature. Using a two-dimensional model, we demonstrate that flexible sheets with symmetric internal forcing, deform when interacting with each other via a thin fluid layer in such a way as to systematically break the overall waveform symmetry, thereby always evolving to an in-phase conformation where energy dissipation is minimized. This dynamics is shown to be mathematically equivalent to that obtained for prescribed waveforms in viscoelastic fluids, emphasizing the crucial role of elasticity in symmetry-breaking and synchronization.

  11. New directions in the science and technology of advanced sheet explosive formulations and the key energetic materials used in the processing of sheet explosives: Emerging trends.

    Science.gov (United States)

    Talawar, M B; Jangid, S K; Nath, T; Sinha, R K; Asthana, S N

    2015-12-30

    This review presents the work carried out by the international community in the area of sheet explosive formulations and its applications in various systems. The sheet explosive is also named as PBXs and is a composite material in which solid explosive particles like RDX, HMX or PETN are dispersed in a polymeric matrix, forms a flexible material that can be rolled/cut into sheet form which can be applied to any complex contour. The designed sheet explosive must possess characteristic properties such as flexible, cuttable, water proof, easily initiable, and safe handling. The sheet explosives are being used for protecting tanks (ERA), light combat vehicle and futuristic infantry carrier vehicle from different attacking war heads etc. Besides, sheet explosives find wide applications in demolition of bridges, ships, cutting and metal cladding. This review also covers the aspects such as risks and hazard analysis during the processing of sheet explosive formulations, effect of ageing on sheet explosives, detection and analysis of sheet explosive ingredients and the R&D efforts of Indian researchers in the development of sheet explosive formulations. To the best of our knowledge, there has been no review article published in the literature in the area of sheet explosives. PMID:26196849

  12. Information sheets on energy

    International Nuclear Information System (INIS)

    These sheets, presented by the Cea, bring some information, in the energy domain, on the following topics: the world energy demand and the energy policy in France and in Europe, the part of the nuclear power in the energy of the future, the greenhouse gases emissions and the fight against the greenhouse effect, the carbon dioxide storage cost and the hydrogen economy. (A.L.B.)

  13. Biomolecular Science (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-04-01

    A brief fact sheet about NREL Photobiology and Biomolecular Science. The research goal of NREL's Biomolecular Science is to enable cost-competitive advanced lignocellulosic biofuels production by understanding the science critical for overcoming biomass recalcitrance and developing new product and product intermediate pathways. NREL's Photobiology focuses on understanding the capture of solar energy in photosynthetic systems and its use in converting carbon dioxide and water directly into hydrogen and advanced biofuels.

  14. Dose reduction in skeletal and chest radiography using a large-area flat-panel detector based on amorphous silicon and thallium-doped cesium iodide: technical background, basic image quality parameters, and review of the literature

    International Nuclear Information System (INIS)

    The two most frequently performed diagnostic X-ray examinations are those of the extremities and of the chest. Thus, dose reduction in the field of conventional skeletal and chest radiography is an important issue and there is a need to reduce man-made ionizing radiation. The large-area flat-panel detector based on amorphous silicon and thallium-doped cesium iodide provides a significant reduction of radiation dose in skeletal and chest radiography compared with traditional imaging systems. This article describes the technical background and basic image quality parameters of this 43 x 43-cm digital system, and summarizes the available literature (years 2000-2003) concerning dose reduction in experimental and clinical studies. Due to its high detective quantum efficiency and dynamic range compared with traditional screen-film systems, a dose reduction of up to 50% is possible without loss of image quality. (orig.)

  15. Dose reduction in skeletal and chest radiography using a large-area flat-panel detector based on amorphous silicon and thallium-doped cesium iodide: technical background, basic image quality parameters, and review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Voelk, Markus; Hamer, Okka W.; Feuerbach, Stefan [Department of Diagnostic Radiology, University Hospital of Regensburg, Franz-Josef-Strauss-Allee 11, 93053, Regensburg (Germany); Strotzer, Michael [Department of Radiology, Hospital Hohe Warte, Hohe Warte 8, 95445, Bayreuth (Germany)

    2004-05-01

    The two most frequently performed diagnostic X-ray examinations are those of the extremities and of the chest. Thus, dose reduction in the field of conventional skeletal and chest radiography is an important issue and there is a need to reduce man-made ionizing radiation. The large-area flat-panel detector based on amorphous silicon and thallium-doped cesium iodide provides a significant reduction of radiation dose in skeletal and chest radiography compared with traditional imaging systems. This article describes the technical background and basic image quality parameters of this 43 x 43-cm digital system, and summarizes the available literature (years 2000-2003) concerning dose reduction in experimental and clinical studies. Due to its high detective quantum efficiency and dynamic range compared with traditional screen-film systems, a dose reduction of up to 50% is possible without loss of image quality. (orig.)

  16. Musical Sheet Segmentation

    Directory of Open Access Journals (Sweden)

    Vinaya V

    2014-05-01

    Full Text Available Music has had an important role in human life from time immemorial. Music has been shared in two ways aurally and as written documents known as musical notes or musical scores. Many ancient cultures have used musical symbols to represent melodies and lyrics but none of them is as comprehensive as a written language or document. Thus the knowledge of ancient music is limited to a few fragments which are mostly unpublished. Hence to preserve such music we need to introduce a computerized system to digitalize and to decode the musical symbol images and reconstruct it as new score which will be in machine readable format. Here the machine readable format is MIDI. Prior to converting the musical symbols into MIDI format, musical sheets need to be segmented for isolating the musical symbols. Since synthetically generated musical sheets are used here, the segmentation process can be carried out using recursive graph cut method. Here we discuss the initial few steps such as staff line removal, text removal and segmentation of musical sheet.

  17. Silicon photonics for telecommunications and biomedicine

    CERN Document Server

    Fathpour, Sasan

    2011-01-01

    Given silicon's versatile material properties, use of low-cost silicon photonics continues to move beyond light-speed data transmission through fiber-optic cables and computer chips. Its application has also evolved from the device to the integrated-system level. A timely overview of this impressive growth, Silicon Photonics for Telecommunications and Biomedicine summarizes state-of-the-art developments in a wide range of areas, including optical communications, wireless technologies, and biomedical applications of silicon photonics. With contributions from world experts, this reference guides

  18. Atomistic simulations of pristine and defective hexagonal BN and SiC sheets under uniaxial tension

    Energy Technology Data Exchange (ETDEWEB)

    Le, Minh-Quy, E-mail: quy.leminh@hust.edu.vn [Department of Mechanics of Materials and Structures, School of Mechanical Engineering, Hanoi University of Science and Technology, No. 1, Dai Co Viet Road, Hanoi (Viet Nam); International Institute for Computational Science and Engineering, Hanoi University of Science and Technology, No. 1, Dai Co Viet Road, Hanoi (Viet Nam); Nguyen, Danh-Truong [Department of Mechanics of Materials and Structures, School of Mechanical Engineering, Hanoi University of Science and Technology, No. 1, Dai Co Viet Road, Hanoi (Viet Nam)

    2014-10-06

    The uniaxial tensile mechanical properties of pristine and defective hexagonal boron nitride (BN) and silicon carbide (SiC) sheets are investigated through a molecular dynamics finite element method with Tersoff and Tersoff-like potentials. 2-Atom vacancy and 2 types of Stone–Wales defects are considered. It is found that uniaxial tensile stress–strain curves of defective and pristine sheets are almost identical up to fracture points. A centered single defect reduces significantly fracture stress and fracture strain from those of the corresponding pristine sheet. In contrast, Young's modulus is nearly unchanged by a single defect. One 2-atom vacancy in the sheet's center reduces 15–18% and 16–25% in fracture stress, and 32–34% and 32–48% in fracture strain of BN and SiC sheets, respectively. Reduction in fracture properties depends on the tensile direction as well as the orientation of Stone–Wales defects.

  19. Growth Mechanism of Silicon Carbide (SIC) on Clean Silicon Surfaces

    International Nuclear Information System (INIS)

    products. For low acetylene exposure, almost the entire surface appears sqrt(3)xsqrt(3)-R30 degrees reconstructed but islands, mainly decorating the step edges, are generally surrounded by 7x7 reconstructed areas, located deeper with respect to the plane of sqrt(3)xsqrt(3)-R degrees reconstruction. For highest acetylene dose, the surface is characterized by nanostructures and large holes (as deep as 3-5 nm) that occupy one of more terraces between the original silicon surface step edges with their inner side constituted of islands itself. For intermediate acetylene exposure, the small increase (from 50 degrees to 700 degrees) of substrate temperature during the reaction is sufficient to make the resulting carbonization mechanism switch towards the highest exposure behaviour. The process can be described as the competitive effect of three mechanisms all providing silicon atoms for the reaction: the first involves the first stages of carbonization when carbon atoms are incorporated in substitutional sites in the silicon matrix and silicon atoms are released free to move on the surface and to participate to nanostructure formation; the second, occurring after the first nucleus of the nanostructure has grown, attracts silicon atoms from neighbouring areas towards the nanostructure itself and produces around it depleted zones characterized by silicon 7x7 reconstruction; the third, prevailing at highest acetylene doses, supplies silicon atoms from the bulk towards the surface to react with carbon atoms leaving voids in the matrix beneath. Experimental conditions, i.e. substrate temperature during reaction and acetylene dose, are found to condition the growth process by favouring one or more mechanisms

  20. Optical loss by surface transfer doping in silicon waveguides

    CERN Document Server

    Alloatti, Luca; Leuthold, Juerg

    2015-01-01

    We show that undoped silicon waveguides may suffer of up to 1.8 dB/cm free-carrier absorption caused by improper surface passivation. To verify the effects of free-carriers we apply a gate field to the waveguides. Smallest losses correspond to higher electrical sheet resistances and are generally obtained with non-zero gate fields. The presence of free carriers for zero gate field is attributed to surface transfer doping. These results open new perspectives for minimizing propagation losses in silicon waveguides and for obtaining low-loss and highly conductive silicon films without applying a gate voltage.

  1. Magneto-hydrodynamics of coupled fluid-sheet interface with mass suction and blowing

    Science.gov (United States)

    Ahmad, R.

    2016-01-01

    There are large number of studies which prescribe the kinematics of the sheet and ignore the sheet's mechanics. However, the current boundary layer analysis investigates the mechanics of both the electrically conducting fluid and a permeable sheet, which makes it distinct from the other studies in the literature. One of the objectives of the current study is to (i) examine the behaviour of magnetic field effect for both the surface and the electrically conducting fluid (ii) investigate the heat and mass transfer between a permeable sheet and the surrounding electrically conducting fluid across the hydro, thermal and mass boundary layers. Self-similar solutions are obtained by considering the RK45 technique. Analytical solution is also found for the stretching sheet case. The skin friction dual solutions are presented for various types of sheet. The influence of pertinent parameters on the dimensionless velocity, shear stress, temperature, mass concentration, heat and mass transfer rates on the fluid-sheet interface is presented graphically as well as numerically. The obtained results are of potential benefit for studying the electrically conducting flow over various soft surfaces such as synthetic plastics, soft silicone sheet and soft synthetic rubber sheet. These surfaces are easily deformed by thermal fluctuations or thermal stresses.

  2. Wind Powering America Initiative (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2011-01-01

    The U.S. Department of Energy's Wind Powering America initiative engages in technology market acceptance, barrier reduction, and technology deployment support activities. This fact sheet outlines ways in which the Wind Powering America team works to reduce barriers to appropriate wind energy deployment, primarily by focusing on six program areas: workforce development, communications and outreach, stakeholder analysis and resource assessment, wind technology technical support, wind power for Native Americans, and federal sector support and collaboration.

  3. The availabilities of arsenic and cadmium in rice paddy fields from a mining area: The role of soil extractable and plant silicon.

    Science.gov (United States)

    Yu, Huan-Yun; Ding, Xiaodong; Li, Fangbai; Wang, Xiangqin; Zhang, Shirong; Yi, Jicai; Liu, Chuanping; Xu, Xianghua; Wang, Qi

    2016-08-01

    Adequate silicon (Si) can greatly boost rice yield and improve grain quality through alleviating stresses associated with heavy metals and metalloids such as arsenic (As) and cadmium (Cd). The soil plant-available Si is relatively low in South China due to severe desilicification and allitization of the soils in this region. Conversely, pollution of heavy metals and metalloids in the soils of this region occurs widely, especially As and Cd pollution in paddy soil. Therefore, evaluating the plant availability of Si in paddy soil of South China and examining its correlation with the availability of heavy metals and metalloids are of great significance. Accordingly, in our study, 107 pairs of soil and rice plant samples were collected from paddy fields contaminated by As and Cd in South China. Significantly positive correlations between Si in rice plants and Si fractions in soils extracted with citric acid, NaOAc-HOAc buffer, and oxalate-ammonium oxalate buffer suggest that these extractants are more suitable for use in extracting plant-available Si in the soils of our present study. Significantly negative correlations between different Si fractions and As or Cd in rice plant tissues and negative exponential correlations between the molar ratios of Si to As/Cd in rice roots, straws, husks or grains and As/Cd in rice grains indicate that Si can significantly alleviate the accumulation of As/Cd from soils to the rice plants. Finally, a contribution assessment of soil properties to As/Cd accumulation in rice grains based on random forest showed that in addition to Si concentrations in soil or rice plants, other factors such as Fe fractions and total phosphorus also contributed largely to As/Cd accumulation in rice grains. Overall, Si exhibited its unique role in mitigating As or Cd stress in rice, and our study results provide strong field evidence for this role. PMID:27209244

  4. Sintered silicon carbide

    International Nuclear Information System (INIS)

    A sintered silicon carbide body having a predominantly equiaxed microstructure consists of 91 to 99.85% by weight of silicon carbide at least 95% of which is the alpha phase, up to 5.0% by weight carbonized organic material, 0.15 to 3.0% of boron, and up to 1.0% by weight additional carbon. A mixture of 91 to 99.85 parts by weight silicon carbide having a surface area of 1 to 100 m2/g, 0.67 to 20 parts of a carbonizable organic binder with a carbon content of at least 33% by weight, 0.15 to 5 parts of a boron source containing 0.15 to 3.0 parts by weight boron and up to 15 parts by weight of a temporary binder is mixed with a solvent, the mixture is then dried, shaped to give a body with a density of at least 1.60 g/cc and fired at 1900 to 22500C to obtain an equiaxed microstructure. (author)

  5. Nanocrystalline silicon based thin film solar cells

    Science.gov (United States)

    Ray, Swati

    2012-06-01

    Amorphous silicon solar cells and panels on glass and flexible substrate are commercially available. Since last few years nanocrystalline silicon thin film has attracted remarkable attention due to its stability under light and ability to absorb longer wavelength portion of solar spectrum. For amorphous silicon/ nanocrystalline silicon double junction solar cell 14.7% efficiency has been achieved in small area and 13.5% for large area modules internationally. The device quality nanocrystalline silicon films have been fabricated by RF and VHF PECVD methods at IACS. Detailed characterizations of the materials have been done. Nanocrystalline films with low defect density and high stability have been developed and used as absorber layer of solar cells.

  6. Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers

    OpenAIRE

    Box, J. E.; X. Fettweis; J. C. Stroeve; Tedesco, M.; Hall, D.K.; Steffen, K.

    2012-01-01

    Greenland ice sheet mass loss has accelerated in the past decade responding to combined glacier discharge and surface melt water runoff increases. During summer, absorbed solar energy, modulated at the surface primarily by albedo, is the dominant factor governing surface melt variability in the ablation area. Using satellite observations of albedo and melt extent with calibrated regional climate model output, we determine the spatial dependence and quantitative impact of the ice sheet...

  7. Digital radiography of the skeleton using a large-area detector based on amorphous silicon technology: Image quality and potential for dose reduction in comparison with screen-film radiography

    International Nuclear Information System (INIS)

    AIM: The purpose of this study was to evaluate a large-area, flat-panel X-ray detector (FD), based on caesium-iodide (CsI) and amorphous silicon (a-Si) with respect to skeletal radiography. Conventional images were compared with digital radiographs using identical and reduced radiation doses. MATERIALS AND METHODS: Thirty consecutive patients were studied prospectively using conventional screen-film radiography (SFR; detector dose 2.5 μGy). Digital images were taken from the same patients with detector doses of 2.5, 1.25 and 0.625 μGy, respectively. The active-matrix detector had a panel size of 43 x 43 cm, a matrix of 3 x 3K, and a pixel size of 143 μm. All hard copies were presented in a random order to eight independent observers, who rated image quality according to subjective quality criteria. Results were assessed for significance using the Student's t -test (confidence level 95%). RESULTS: A statistically significant preference for digital over conventional images was revealed for all quality criteria, except for over-exposure (detector dose 2.5 μGy). Digital images with a 50% dose showed a small, statistically not significant, inferiority compared with SFR. The FD-technique was significantly inferior to SFR at 75% dose reduction regarding bone cortex and trabecula, contrast and overall impression. No statistically significant differences were found with regard to over- and under-exposure and soft tissue presentation. CONCLUSION: Amorphous silicon-based digital radiography yields good image quality. The potential for dose reduction depends on the clinical query. Volk, M. (2000)

  8. Thin, High Lifetime Silicon Wafers with No Sawing; Re-crystallization in a Thin Film Capsule

    Energy Technology Data Exchange (ETDEWEB)

    Emanuel Sachs

    2013-01-16

    The project fits within the area of renewable energy called photovoltaics (PV), or the generation of electricity directly from sunlight using semiconductor devices. PV has the greatest potential of any renewable energy technology. The vast majority of photovoltaic modules are made on crystalline silicon wafers and these wafers accounts for the largest fraction of the cost of a photovoltaic module. Thus, a method of making high quality, low cost wafers would be extremely beneficial to the PV industry The industry standard technology creates wafers by casting an ingot and then sawing wafers from the ingot. Sawing rendered half of the highly refined silicon feedstock as un-reclaimable dust. Being a brittle material, the sawing is actually a type of grinding operation which is costly both in terms of capital equipment and in terms of consumables costs. The consumables costs associated with the wire sawing technology are particularly burdensome and include the cost of the wire itself (continuously fed, one time use), the abrasive particles, and, waste disposal. The goal of this project was to make wafers directly from molten silicon with no sawing required. The fundamental concept was to create a very low cost (but low quality) wafer of the desired shape and size and then to improve the quality of the wafer by a specialized thermal treatment (called re-crystallization). Others have attempted to create silicon sheet by recrystallization with varying degrees of success. Key among the difficulties encountered by others were: a) difficulty in maintaining the physical shape of the sheet during the recrystallization process and b) difficulty in maintaining the cleanliness of the sheet during recrystallization. Our method solved both of these challenges by encapsulating the preform wafer in a protective capsule prior to recrystallization (see below). The recrystallization method developed in this work was extremely effective at maintaining the shape and the cleanliness of the

  9. Hanford Site Treated Effluent Disposal Facility process flow sheet

    International Nuclear Information System (INIS)

    This report presents a novel method of using precipitation, destruction and recycle factors to prepare a process flow sheet. The 300 Area Treated Effluent Disposal Facility (TEDF) will treat process sewer waste water from the 300 Area of the Hanford Site, located near Richland, Washington, and discharge a permittable effluent flow into the Columbia River. When completed and operating, the TEDF effluent water flow will meet or exceed water quality standards for the 300 Area process sewer effluents. A preliminary safety analysis document (PSAD), a preconstruction requirement, needed a process flow sheet detailing the concentrations of radionuclides, inorganics and organics throughout the process, including the effluents, and providing estimates of stream flow quantities, activities, composition, and properties (i.e. temperature, pressure, specific gravity, pH and heat transfer rates). As the facility begins to operate, data from process samples can be used to provide better estimates of the factors, the factors can be entered into the flow sheet and the flow sheet will estimate more accurate steady state concentrations for the components. This report shows how the factors were developed and how they were used in developing a flow sheet to estimate component concentrations for the process flows. The report concludes with how TEDF sample data can improve the ability of the flow sheet to accurately predict concentrations of components in the process

  10. Partial crystallization of silicon by high intensity laser irradiation

    International Nuclear Information System (INIS)

    Commercial single crystal silicon wafers and amorphous silicon films piled on single crystal silicon wafers were irradiated with a femtosecond pulsed laser and a nanosecond pulsed laser at irradiation intensities between 1017 W/cm2 and 109 W/cm2. In the single crystal silicon substrate, the irradiated area was changed to polycrystalline silicon and the piled silicon around the irradiated area has spindly column structures constructed of polycrystalline and amorphous silicon. In particular, in the case of the higher irradiation intensity of 1016 W/cm2, the irradiated area was oriented to the same crystal direction as the substrate. In the case of the lower irradiation intensity of 108 W/cm2, only amorphous silicon was observed around the irradiated area, even when the target was single crystal silicon. In contrast, only amorphous silicon particles were found to be piled on the amorphous silicon film, irrespective of the intensity and pulse duration. Three-dimensional thermal diffusion equation for the piled particles on the substrate was solved by using the finite difference methods. The results of our heat-flow simulation of the piled particles almost agree with the experimental results.

  11. Single-crystalline ZnO sheet Source-Gated Transistors

    Science.gov (United States)

    Dahiya, A. S.; Opoku, C.; Sporea, R. A.; Sarvankumar, B.; Poulin-Vittrant, G.; Cayrel, F.; Camara, N.; Alquier, D.

    2016-01-01

    Due to their fabrication simplicity, fully compatible with low-cost large-area device assembly strategies, source-gated transistors (SGTs) have received significant research attention in the area of high-performance electronics over large area low-cost substrates. While usually based on either amorphous or polycrystalline silicon (α-Si and poly-Si, respectively) thin-film technologies, the present work demonstrate the assembly of SGTs based on single-crystalline ZnO sheet (ZS) with asymmetric ohmic drain and Schottky source contacts. Electrical transport studies of the fabricated devices show excellent field-effect transport behaviour with abrupt drain current saturation (IDSSAT) at low drain voltages well below 2 V, even at very large gate voltages. The performance of a ZS based SGT is compared with a similar device with ohmic source contacts. The ZS SGT is found to exhibit much higher intrinsic gain, comparable on/off ratio and low off currents in the sub-picoamp range. This approach of device assembly may form the technological basis for highly efficient low-power analog and digital electronics using ZnO and/or other semiconducting nanomaterial.

  12. Silicone chain extender

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a silicone chain extender, more particularly a chain extender for silicone polymers and copolymers, to a chain extended silicone polymer or copolymer and to a functionalized chain extended silicone polymer or copolymer, to a method for the preparation thereof and...

  13. The stretch zone of automotive steel sheets

    Indian Academy of Sciences (India)

    Ľ Ambriško; L Pešek

    2014-04-01

    The paper deals with an experimental determination of the stretch zone dimensions in the notch tip in thin steel sheets. The stretch zone dimensions depend on steel grade, on the rolling direction as well as on the loading rate. Stretch zones were observed and measured on three steel grades. Fracture area and stretch zones were analysed by SEM. Stable crack growth was monitored by videoextensometry techniques on CT (Compact Tension) specimens. Specimens were loaded under two loading rates by eccentric tension, whereby the deformation in the notch surrounding area was recorded using a non-contact measurement–videoextensometry technique. Linear relation between the stretch zone dimensions was determined.

  14. Method of fabricating porous silicon carbide (SiC)

    Science.gov (United States)

    Shor, Joseph S. (Inventor); Kurtz, Anthony D. (Inventor)

    1995-01-01

    Porous silicon carbide is fabricated according to techniques which result in a significant portion of nanocrystallites within the material in a sub 10 nanometer regime. There is described techniques for passivating porous silicon carbide which result in the fabrication of optoelectronic devices which exhibit brighter blue luminescence and exhibit improved qualities. Based on certain of the techniques described porous silicon carbide is used as a sacrificial layer for the patterning of silicon carbide. Porous silicon carbide is then removed from the bulk substrate by oxidation and other methods. The techniques described employ a two-step process which is used to pattern bulk silicon carbide where selected areas of the wafer are then made porous and then the porous layer is subsequently removed. The process to form porous silicon carbide exhibits dopant selectivity and a two-step etching procedure is implemented for silicon carbide multilayers.

  15. Silicon Micromachining

    Science.gov (United States)

    Elwenspoek, Miko; Jansen, Henri V.

    2004-08-01

    This comprehensive book provides an overview of the key techniques used in the fabrication of micron-scale structures in silicon. Recent advances in these techniques have made it possible to create a new generation of microsystem devices, such as microsensors, accelerometers, micropumps, and miniature robots. The authors underpin the discussion of each technique with a brief review of the fundamental physical and chemical principles involved. They pay particular attention to methods such as isotropic and anisotropic wet chemical etching, wafer bonding, reactive ion etching, and surface micromachining. There is a special section on bulk micromachining, and the authors also discuss release mechanisms for movable microstructures. The book is a blend of detailed experimental and theoretical material, and will be of great interest to graduate students and researchers in electrical engineering and materials science whose work involves the study of micro-electromechanical systems (MEMS).

  16. Material Safety Data Sheets (MSDS)

    CERN Document Server

    Lalley, J

    About 250.000 Material Safety Data sheets from the U.S. Government Department of Defense MSDS database, a mirror of data from siri.uvm.edu, MSDS sheets maintained by Cornell University Environmental Health and Safety and other Cornell departments.

  17. Thin silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R.B.; Bacon, C.; DiReda, V.; Ford, D.H.; Ingram, A.E.; Cotter, J.; Hughes-Lampros, T.; Rand, J.A.; Ruffins, T.R.; Barnett, A.M. [Astro Power Inc., Solar Park, Newark, DE (United States)

    1992-12-01

    The silicon-film design achieves high performance by using a dun silicon layer and incorporating light trapping. Optimally designed thin crystalline solar cells (<50 microns thick) have performance advantages over conventional thick devices. The high-performance silicon-film design employs a metallurgical barrier between the low-cost substrate and the thin silicon layer. Light trapping properties of silicon-film on ceramic solar cells are presented and analyzed. Recent advances in process development are described here.

  18. Soft Costs Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-05-01

    This fact sheet is an overview of the systems integration subprogram at the U.S. Department of Energy SunShot Initiative. Soft costs can vary significantly as a result of a fragmented energy marketplace. In the U.S., there are 18,000 jurisdictions and 3,000 utilities with different rules and regulations for how to go solar. The same solar equipment may vary widely in its final installation price due to process and market variations across jurisdictions, creating barriers to rapid industry growth. SunShot supports the development of innovative solutions that enable communities to build their local economies and establish clean energy initiatives that meet their needs, while at the same time creating sustainable solar market conditions.

  19. Photovoltaics Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-02-01

    This fact sheet is an overview of the Photovoltaics (PV) subprogram at the U.S. Department of Energy SunShot Initiative. The U.S. Department of Energy (DOE)’s Solar Energy Technologies Office works with industry, academia, national laboratories, and other government agencies to advance solar PV, which is the direct conversion of sunlight into electricity by a semiconductor, in support of the goals of the SunShot Initiative. SunShot supports research and development to aggressively advance PV technology by improving efficiency and reliability and lowering manufacturing costs. SunShot’s PV portfolio spans work from early-stage solar cell research through technology commercialization, including work on materials, processes, and device structure and characterization techniques.

  20. Modelling the Antarctic Ice Sheet

    DEFF Research Database (Denmark)

    Pedersen, Jens Olaf Pepke; Holm, A.

    2015-01-01

    Science) Antarctic Ice Sheet (DAIS) model (Shaffer 2014) is forced by reconstructed time series of Antarctic temperature, global sea level and ocean subsurface temperature over the last two glacial cycles. In this talk a modelling work of the Antarctic ice sheet over most of the Cenozoic era using the......The Antarctic ice sheet is a major player in the Earth’s climate system and is by far the largest depository of fresh water on the planet. Ice stored in the Antarctic ice sheet (AIS) contains enough water to raise sea level by about 58 m, and ice loss from Antarctica contributed significantly to...... DAIS model will be presented. G. Shaffer (2014) Formulation, calibration and validation of the DAIS model (version 1), a simple Antarctic ice sheet model sensitive to variations of sea level and ocean subsurface temperature, Geosci. Model Dev., 7, 1803‐1818...

  1. SILICON REFINING BY VACUUM TREATMENT

    Directory of Open Access Journals (Sweden)

    André Alexandrino Lotto

    2014-12-01

    Full Text Available This work aims to investigate the phosphorus removal by vacuum from metallurgical grade silicon (MGSi (98.5% to 99% Si. Melting experiments were carried out in a vacuum induction furnace, varying parameters such as temperature, time and relation area exposed to the vacuum / volume of molten silicon. The results of chemical analysis were obtained by inductively coupled plasma (ICP, and evaluated based on thermodynamic and kinetic aspects of the reaction of vaporization of the phosphorus in the silicon. The phosphorus was decreased from 33 to approximately 1.5 ppm after three hours of vacuum treatment, concluding that the evaporation step is the controlling step of the process for parameters of temperature, pressure and agitation used and refining by this process is technically feasible.

  2. Vitamin and Mineral Supplement Fact Sheets

    Science.gov (United States)

    ... Tables Online DRI Tool Daily Value (DV) Tables Vitamin and Mineral Supplement Fact Sheets Search the list ... Supplements: Background Information Botanical Dietary Supplements: Background Information Vitamin and Mineral Fact Sheets Botanical Supplement Fact Sheets ...

  3. Rational use of hot-rolled product of steel type 08ps for manufacturing cold rolled sheet

    International Nuclear Information System (INIS)

    Mechanical properties of cold rolled sheet of steel type 08ps has bent investigated depending of melt chemical composition. Through the values of pair and multiple correlation coefficients a conclusion has been made that carbon, manganese and silicon have the strongest effect on strength and plastic properties. A table has been compiled for a practical use which makes it possible to determine sheet properties depending an amounts of silicon (0.01-0.17%), manganese (0.31-0.50%) at carbon content of 0.08% C

  4. Effect of Silicon and Manganese on Mechanical Properties of Low-Carbon Plain TRIP Steel

    Institute of Scientific and Technical Information of China (English)

    LI Zhuang; WU Di; HU Rong

    2005-01-01

    A great deal of stabilized retained austenite can be obtained by means of austempering immediately after intercritical annealing in the low-carbon plain steel sheets which only contain alloying elements of silicon and manganese. Transformation from retained austenite to martensite may be induced by strain at a temperature ranging from 50 ℃ to 400 ℃ during tension testing. Transformation-induced plasticity (TRIP) may occur. Alloying of silicon improves the stability of retained austenite. Mechanical properties of the present TRIP steels containing manganese increase with increasing silicon amount when the amount of silicon is less than two percent.

  5. Magnetic Properties of Cobalt-coated Silicon Steels Prepared by Electrodeposition

    OpenAIRE

    Somkane PIROMRAK; Jantaratana, Pongsakorn; Sirisathitkul, Chitnarong

    2007-01-01

    Magnetic properties of silicon steels (1.26 % silicon) coated by cobalt of varying thickness were studied. Cobalt ranging from 11 to 68 µm in thickness was deposited on silicon steel substrates (0.5 mm thick, 0.4 mm wide and 55.0 mm long) cut from sheets of recycled transformer cores. By electrodeposition in CoSO4 electrolyte with 90 mA applied current at pH 1.86, the deposition rate was 1.11 µm/min. Although deposition of cobalt increased saturation induction of silicon steels, it also incre...

  6. How might the North American ice sheet influence the Northwestern Eurasian climate?

    Directory of Open Access Journals (Sweden)

    P. Beghin

    2015-01-01

    Full Text Available During the last glacial period (∼21 000 years ago, two continental-scale ice sheets covered the Canada and northern Europe. It is now widely acknowledged that these past ice sheets exerted a strong influence on climate by causing changes in atmospheric and oceanic circulations. In turn, these changes may have impacted the development of the ice sheets themselves through a combination of different feedback mechanisms. The present study is designed to investigate the potential impact of the North American ice sheet on the surface mass balance (SMB of the Eurasian ice sheet through simulated changes in the past glacial atmospheric circulation. Using the LMDz5 atmospheric circulation model, we carried out twelve experiments run under constant Last Glacial Maximum (LGM conditions for insolation, greenhouse gases and ocean. In the all experiments, the Eurasian ice sheet is removed. The twelve experiments differ in the North American ice-sheet topography, ranging from a white and flat (present-day topography ice sheet to a full-size LGM ice sheet. This experimental design allows to disentangle the albedo and the topographic impacts of the North American ice sheet onto the climate. The results are compared to our baseline experiment where both the North American and the Eurasian ice sheets have been removed. In summer, we show that the only albedo effect of the American ice sheet modifies the pattern of planetary waves with respect to the no-ice sheet case, causing a cooling of the Eurasian region. By contrast, the atmospheric circulation changes induced by the topography of the North American ice sheet imply summer warming in Northwestern Eurasia. In winter, the Scandinavian and the Barents–Kara regions respond differently to the albedo effect: in response to atmospheric circulation changes, Scandinavia is warmed up and precipitation is more abundant whereas Barents–Kara area is cooled down, decreasing convection process and thus leading to less

  7. Concentrator silicon cell research

    Energy Technology Data Exchange (ETDEWEB)

    Green, M.A.; Wenham, S.R.; Zhang, F.; Zhao, J.; Wang, A. [New South Wales Univ., Kensington (Australia). Solar Photovoltaic Lab.

    1992-04-01

    This project continued the developments of high-efficiency silicon concentrator solar cells with the goal of achieving a cell efficiency in the 26 to 27 percent range at a concentration level of 150 suns of greater. The target efficiency was achieved with the new PERL (passivated emitter, rear locally diffused) cell structure, but only at low concentration levels around 20 suns. The PERL structure combines oxide passivation of both top and rear surfaces of the cells with small area contact to heavily doped regions on the top and rear surfaces. Efficiency in the 22 to 23 percent range was also demonstrated for large-area concentrator cells fabricated with the buried contact solar cell processing sequence, either when combined with prismatic covers or with other innovative approaches to reduce top contact shadowing. 19 refs.

  8. Photobiology Research Laboratory (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-06-01

    This fact sheet provides information about Photobiology Research Laboratory capabilities and applications at NREL. The photobiology group's research is in four main areas: (1) Comprehensive studies of fuel-producing photosynthetic, fermentative, and chemolithotrophic model microorganisms; (2) Characterization and engineering of redox enzymes and proteins for fuel production; (3) Genetic and pathway engineering of model organisms to improve production of hydrogen and hydrocarbon fuels; and (4) Studies of nanosystems using biological and non-biological materials in hybrid generation. NREL's photobiology research capabilities include: (1) Controlled and automated photobioreactors and fermenters for growing microorganisms under a variety of environmental conditions; (2) High-and medium-throughput screening of H{sub 2}-producing organisms; (3) Homologous and heterologous expression, purification, and biochemical/biophysical characterization of redox enzymes and proteins; (4) Qualitative and quantitative analyses of gases, metabolites, carbohydrates, lipids, and proteins; (5) Genetic and pathway engineering and development of novel genetic toolboxes; and (6) Design and spectroscopic characterization of enzyme-based biofuel cells and energy conversion nanodevices.

  9. Capillary Break Beneath a Slab: Polyethylene Sheeting over Aggregate; Southwestern Pennsylvania (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-07-01

    This document provides content for three areas of the Building America Solution Center. First, "Insulating Closed Crawlspace Walls and Band Joist Area" describes how to install rigid foam insulation on the interior perimeter walls and band joist area in closed crawlspace foundations of homes. Second, "Removing Construction Debris from Flexible Ducts" describes how to clean flexible ducts after construction or major renovation of a home to remove debris resulting from building materials, particularly airborne dust and particulates. Third, images, CAD drawings, and a case study illustrate right and wrong ways to apply polyethylene sheeting over aggregate. Similarly, a CAD drawing is included that illustrates the use of a concrete slab over polyethylene.

  10. Coupling of climate models and ice sheet models by surface mass balance gradients: application to the Greenland Ice Sheet

    Directory of Open Access Journals (Sweden)

    M. M. Helsen

    2012-03-01

    Full Text Available It is notoriously difficult to couple surface mass balance (SMB results from climate models to the changing geometry of an ice sheet model. This problem is traditionally avoided by using only accumulation from a climate model, and parameterizing the meltwater run-off as a function of temperature, which is often related to surface elevation (Hs. In this study, we propose a new strategy to calculate SMB, to allow a direct adjustment of SMB to a change in ice sheet topography and/or a change in climate forcing. This method is based on elevational gradients in the SMB field as computed by a regional climate model. Separate linear relations are derived for ablation and accumulation, using pairs of Hs and SMB within a minimum search radius. The continuously adjusting SMB forcing is consistent with climate model forcing fields, also for initially non-glaciated areas in the peripheral areas of an ice sheet. When applied to an asynchronous coupled ice sheet – climate model setup, this method circumvents traditional temperature lapse rate assumptions. Here we apply it to the Greenland Ice Sheet (GrIS. Experiments using both steady-state forcing and glacial-interglacial forcing result in realistic ice sheet reconstructions.

  11. The Apparent Contact Angle and Wetted Area of Active Alloys on Silicon Carbide as a Function of the Temperature and the Surface Roughness: A Multivariate Approach

    Science.gov (United States)

    Tillmann, Wolfgang; Pfeiffer, Jan; Wojarski, Lukas

    2015-08-01

    Despite the broad field of applications for active filler alloys for brazing ceramics, as well as intense research work on the wetting and spreading behavior of these alloys on ceramic surfaces within the last decades, the manufactured joints still exhibit significant variations in their properties due to the high sensitivity of the alloys to changing brazing conditions. This increases the need for investigations of the wetting and spreading behavior of filler alloys with regard to the dominating influences combined with their interdependencies, instead of solely focusing on single parameter investigations. In this regard, measurements of the wetting angle and area were conducted at solidified AgCuTi and CuSnTi alloys on SiC substrates. Based on these measurements, a regression model was generated, illustrating the influence of the brazing temperature, the roughness of the faying surfaces, the furnace atmosphere, and their interdependencies on the wetting and spreading behavior of the filler alloys. It was revealed that the behavior of the melts was significantly influenced by the varied brazing parameters, as well as by their interdependencies. This result was also predicted by the developed model and showed a high accuracy.

  12. Seeing graphene-based sheets

    Directory of Open Access Journals (Sweden)

    Jaemyung Kim

    2010-03-01

    Full Text Available Graphene-based sheets such as graphene, graphene oxide and reduced graphene oxide have stimulated great interest due to their promising electronic, mechanical and thermal properties. Microscopy imaging is indispensable for characterizing these single atomic layers, and oftentimes is the first measure of sample quality. This review provides an overview of current imaging techniques for graphene-based sheets and highlights a recently developed fluorescence quenching microscopy technique that allows high-throughput, high-contrast imaging of graphene-based sheets on arbitrary substrate and even in solution.

  13. Number & operations task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 6-8, our State Standards-based combined resource meets the number & operations concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are problems involving place value, fractions, addition, subtraction and using money. The combined task & drill sheets offer spac

  14. Nuclear level schemes A = 45 through A = 257 from nuclear data sheets

    CERN Document Server

    Oak Ridge National Laboratory. Oak Ridge, TN

    1973-01-01

    Nuclear Level Schemes A=45 through A=257 from Nuclear Data Sheets is a collection of level schemes from the Nuclear Data Sheets prepared as reference to nuclear structure information for A>44. The book provides drawing for conventions used on nuclear data sheets; special notes regarding level schemes; and nuclear level schemes a=45 through a=257. Researchers and workers in the applied areas will find the book useful.

  15. Black luminescent silicon

    Energy Technology Data Exchange (ETDEWEB)

    Pezoldt, Joerg [FG Nanotechnologie, Institut fuer Mikro- und Nanotechnologie, TU Ilmenau, Postfach 100565, 98684 Ilmenau (Germany); Kups, Thomas [FG Werkstoffe der Elektrotechnik, Institut fuer Mikro- und Nanotechnologien, TU Ilmenau, Postfach 1005765, 98684 Ilmenau (Germany); Stubenrauch, Mike [FG Mikromechanische Systeme, Institut fuer Mikro- und Nanotechnologien, TU Ilmenau, Postfach 1005765, 98684 Ilmenau (Germany); Fischer, Michael [FG Elektroniktechnologie, Institut fuer Mikro- und Nanotechnologien, TU Ilmenau, Postfach 1005765, 98684 Ilmenau (Germany)

    2011-03-15

    Black silicon is a fascinating multipurpose modification of bulk silicon which can be fabricated in a selforganized structure formation process during dry etching of bare silicon wafer leading to the formation of a high density of silicon needles. The smallest dimension of the tips approaches values between 1 and 2 nm. The silicon nanostructure exhibits an extremely low diffuse reflectivity. The nanosized tips and their coating with fluorine doped nonstoichiometric silicon dioxide are responsible for cathodoluminescence in the blue-green and red regions of the visible spectra (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Porous siliconformation and etching process for use in silicon micromachining

    Science.gov (United States)

    Guilinger, Terry R.; Kelly, Michael J.; Martin, Jr., Samuel B.; Stevenson, Joel O.; Tsao, Sylvia S.

    1991-01-01

    A reproducible process for uniformly etching silicon from a series of micromechanical structures used in electrical devices and the like includes providing a micromechanical structure having a silicon layer with defined areas for removal thereon and an electrochemical cell containing an aqueous hydrofluoric acid electrolyte. The micromechanical structure is submerged in the electrochemical cell and the defined areas of the silicon layer thereon are anodically biased by passing a current through the electrochemical cell for a time period sufficient to cause the defined areas of the silicon layer to become porous. The formation of the depth of the porous silicon is regulated by controlling the amount of current passing through the electrochemical cell. The micromechanical structure is then removed from the electrochemical cell and submerged in a hydroxide solution to remove the porous silicon. The process is subsequently repeated for each of the series of micromechanical structures to achieve a reproducibility better than 0.3%.

  17. Thermodynamic and kinetic properties of indium-implanted silicon. II

    International Nuclear Information System (INIS)

    Impurity depth profiles were obtained by differential sheet resistivity and Hall coefficient measurements on Si(100) implanted with indium to doses of 1013 and 1014 ions cm-2 at an energy of 190 keV. After recovery of the implant damage the samples were diffused in an inert atmosphere at temperatures ranging from 1000 to 12000C. The data show that the carrier concentration is nearly independent of the implanted dose, while the indium diffusivity in silicon is higher for the samples implanted at 1014 ions cm-2. The solid solubility of indium in silicon is around 1017 cm-3. The hole mobility is about half that of boron-doped silicon and, in the range considered, the main contribution to the resistivity is from ionized impurity scattering. A model is proposed to account for the peculiar behaviour observed in indium-implanted silicon. (Auth.)

  18. Selectively reflective transparent sheets

    Science.gov (United States)

    Waché, Rémi; Florescu, Marian; Sweeney, Stephen J.; Clowes, Steven K.

    2015-08-01

    We investigate the possibility to selectively reflect certain wavelengths while maintaining the optical properties on other spectral ranges. This is of particular interest for transparent materials, which for specific applications may require high reflectivity at pre-determined frequencies. Although there exist currently techniques such as coatings to produce selective reflection, this work focuses on new approaches for mass production of polyethylene sheets which incorporate either additives or surface patterning for selective reflection between 8 to 13 μ m. Typical additives used to produce a greenhouse effect in plastics include particles such as clays, silica or hydroxide materials. However, the absorption of thermal radiation is less efficient than the decrease of emissivity as it can be compared with the inclusion of Lambertian materials. Photonic band gap engineering by the periodic structuring of metamaterials is known in nature for producing the vivid bright colors in certain organisms via strong wavelength-selective reflection. Research to artificially engineer such structures has mainly focused on wavelengths in the visible and near infrared. However few studies to date have been carried out to investigate the properties of metastructures in the mid infrared range even though the patterning of microstructure is easier to achieve. We present preliminary results on the diffuse reflectivity using FDTD simulations and analyze the technical feasibility of these approaches.

  19. Carbon nanotube-coated silicone as a flexible and electrically conductive biomedical material

    International Nuclear Information System (INIS)

    Artificial cell scaffolds that support cell adhesion, growth, and organization need to be fabricated for various purposes. Recently, there have been increasing reports of cell patterning using electrical fields. We fabricated scaffolds consisting of silicone sheets coated with single-walled (SW) or multi-walled (MW) carbon nanotubes (CNTs) and evaluated their electrical properties and biocompatibility. We also performed cell alignment with dielectrophoresis using CNT-coated sheets as electrodes. Silicone coated with 10 μg/cm2 SWCNTs exhibited the least sheet resistance (0.8 kΩ/sq); its conductivity was maintained even after 100 stretching cycles. CNT coating also improved cell adhesion and proliferation. When an electric field was applied to the cell suspension introduced on the CNT-coated scaffold, the cells became aligned in a pearl-chain pattern. These results indicate that CNT coating not only provides electro-conductivity but also promotes cell adhesion to the silicone scaffold; cells seeded on the scaffold can be organized using electricity. These findings demonstrate that CNT-coated silicone can be useful as a biocompatible scaffold. - Highlights: ► We fabricated a CNT-coated silicone which has conductivity and biocompatibility. ► The conductivity was maintained after 100 cycles of stretching. ► CNT coatings enabled C2C12 cells adhere to the silicone surface. ► Cells were aligned with dielectrophoresis between CNT-coated silicone surfaces.

  20. Carbon nanotube-coated silicone as a flexible and electrically conductive biomedical material

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Makoto, E-mail: matsuoka@den.hokudai.ac.jp [Department of Oral and Maxillofacial Surgery, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan); Japan Society for the Promotion of Science (Japan); Akasaka, Tsukasa [Department of Dental Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan); Totsuka, Yasunori [Department of Oral and Maxillofacial Surgery, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan); Watari, Fumio [Department of Dental Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan)

    2012-04-01

    Artificial cell scaffolds that support cell adhesion, growth, and organization need to be fabricated for various purposes. Recently, there have been increasing reports of cell patterning using electrical fields. We fabricated scaffolds consisting of silicone sheets coated with single-walled (SW) or multi-walled (MW) carbon nanotubes (CNTs) and evaluated their electrical properties and biocompatibility. We also performed cell alignment with dielectrophoresis using CNT-coated sheets as electrodes. Silicone coated with 10 {mu}g/cm{sup 2} SWCNTs exhibited the least sheet resistance (0.8 k{Omega}/sq); its conductivity was maintained even after 100 stretching cycles. CNT coating also improved cell adhesion and proliferation. When an electric field was applied to the cell suspension introduced on the CNT-coated scaffold, the cells became aligned in a pearl-chain pattern. These results indicate that CNT coating not only provides electro-conductivity but also promotes cell adhesion to the silicone scaffold; cells seeded on the scaffold can be organized using electricity. These findings demonstrate that CNT-coated silicone can be useful as a biocompatible scaffold. - Highlights: Black-Right-Pointing-Pointer We fabricated a CNT-coated silicone which has conductivity and biocompatibility. Black-Right-Pointing-Pointer The conductivity was maintained after 100 cycles of stretching. Black-Right-Pointing-Pointer CNT coatings enabled C2C12 cells adhere to the silicone surface. Black-Right-Pointing-Pointer Cells were aligned with dielectrophoresis between CNT-coated silicone surfaces.

  1. Wettability and silicone hydrogel lenses: a review.

    Science.gov (United States)

    Keir, Nancy; Jones, Lyndon

    2013-01-01

    One of the major breakthroughs in the development of silicone hydrogel contact lenses has related to the ability of manufacturers to overcome the surface hydrophobicity that occurred with silicone elastomer lenses. However, the wettability of silicone hydrogel lenses continues to be of interest as a potential link between in vivo lens performance and contact lens-related comfort. This article will review some of the knowledge we have gained in the area of contact lens wettability over the past decade and will discuss some of the challenges related to its measurement. PMID:23274760

  2. Transistors using crystalline silicon devices on glass

    Science.gov (United States)

    McCarthy, Anthony M.

    1995-01-01

    A method for fabricating transistors using single-crystal silicon devices on glass. This method overcomes the potential damage that may be caused to the device during high voltage bonding and employs a metal layer which may be incorporated as part of the transistor. This is accomplished such that when the bonding of the silicon wafer or substrate to the glass substrate is performed, the voltage and current pass through areas where transistors will not be fabricated. After removal of the silicon substrate, further metal may be deposited to form electrical contact or add functionality to the devices. By this method both single and gate-all-around devices may be formed.

  3. State Fact Sheets on COPD

    Science.gov (United States)

    ... About CDC.gov . COPD Homepage Data and Statistics Fact Sheets Publications Resources COPD en Español Related Links Air Pollution & Respiratory Health Air Quality, Fires, and Volcanic Eruptions ...

  4. Measurements and Characterization (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2011-06-01

    Capabilities fact sheet for the National Center for Photovoltaics: Measurements and Characterization that includes scope, core competencies and capabilities, and contact/web information for Analytical Microscopy, Electro-Optical Characterization, Surface Analysis, and Cell and Module Performance.

  5. Seeing graphene-based sheets

    OpenAIRE

    Jaemyung Kim; Franklin Kim; Jiaxing Huang

    2010-01-01

    Graphene-based sheets such as graphene, graphene oxide and reduced graphene oxide have stimulated great interest due to their promising electronic, mechanical and thermal properties. Microscopy imaging is indispensable for characterizing these single atomic layers, and oftentimes is the first measure of sample quality. This review provides an overview of current imaging techniques for graphene-based sheets and highlights a recently developed fluorescence quenching microscopy technique that al...

  6. Financial intermediary balance sheet management

    OpenAIRE

    Adrian,Tobias; Shin, Hyun Song

    2011-01-01

    Conventional discussions of balance sheet management by nonfinancial firms take the set of positive net present value (NPV) projects as given, which in turn determines the size of the assets of the firm. The focus is on the composition of equity and debt in funding such assets. In contrast, the balance sheet management of financial intermediaries reveals that it is equity that behaves like the predetermined variable, and the asset size of the bank or financial intermediary is determined by th...

  7. Energy information sheets, July 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the public. The Energy Information Sheets was developed to provide general information on various aspects of fuel production, prices, consumption, and capability. Additional information on related subject matter can be found in other Energy Information Administration (EIA) publications as referenced at the end of each sheet.

  8. Energy information sheets, September 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the public. The Energy Information Sheets was developed to provide general information on various aspects of fuel production, prices, consumption, and capability. Additional information on related subject matter can be found in other Energy Information Administration (EIA) publications as referenced at the end of each sheet.

  9. Bonding silicones with epoxies

    Energy Technology Data Exchange (ETDEWEB)

    Tira, J.S.

    1980-01-01

    It is shown that silicones, both room temperature vulcanizing (RTV) and millable rubber (press cured) can be successfully bonded to other materials using plasma treatment and epoxy adhesives. The plasma treatment using dry air atmosphere increases the surface energy of the silicone and thus provides a lower water contact angle. This phenomenon allows the epoxy adhesive to wet the silicone surface and ultimately bond. Bond strengths are sufficiently high to result in failures in the silicone materials rather than the adhesive bond.

  10. Intraventricular Silicone Oil

    OpenAIRE

    Mathis, Stéphane; Boissonnot, Michèle; Tasu, Jean-Pierre; Simonet, Charles; Ciron, Jonathan; Neau, Jean-Philippe

    2016-01-01

    Abstract Intracranial silicone oil is a rare complication of intraocular endotamponade with silicone oil. We describe a case of intraventricular silicone oil fortuitously observed 38 months after an intraocular tamponade for a complicated retinal detachment in an 82 year-old woman admitted in the Department of Neurology for a stroke. We confirm the migration of silicone oil along the optic nerve. We discuss this rare entity with a review of the few other cases reported in the medical literatu...

  11. Silicon: electrochemistry and luminescence

    OpenAIRE

    Kooij, Ernst Stefan

    2001-01-01

    The electrochemistry of crystalline and porous silicon and the luminescence from porous silicon has been studied. One chapter deals with a model for the anodic dissolution of silicon in HF solution. In following chapters both the electrochemistry and various ways of generating visible luminescence from porous silicon is investigated. Both under cathodic and anodic polarization emission can be observed in the presence of oxidizing and reducing agents, respectively. Also in indifferent electrol...

  12. Pituitary Tumors Fact Sheet

    Science.gov (United States)

    ... Breasts Produce milk for nursing a baby Growth hormone (GH) Many areas of the body Control growth and metabolism Adrenocorticotropic hormone (ACTH) Adrenal gland Produce cortisol, needed to handle ...

  13. Silicon photonics: some remaining challenges

    Science.gov (United States)

    Reed, G. T.; Topley, R.; Khokhar, A. Z.; Thompson, D. J.; Stanković, S.; Reynolds, S.; Chen, X.; Soper, N.; Mitchell, C. J.; Hu, Y.; Shen, L.; Martinez-Jimenez, G.; Healy, N.; Mailis, S.; Peacock, A. C.; Nedeljkovic, M.; Gardes, F. Y.; Soler Penades, J.; Alonso-Ramos, C.; Ortega-Monux, A.; Wanguemert-Perez, G.; Molina-Fernandez, I.; Cheben, P.; Mashanovich, G. Z.

    2016-03-01

    This paper discusses some of the remaining challenges for silicon photonics, and how we at Southampton University have approached some of them. Despite phenomenal advances in the field of Silicon Photonics, there are a number of areas that still require development. For short to medium reach applications, there is a need to improve the power consumption of photonic circuits such that inter-chip, and perhaps intra-chip applications are viable. This means that yet smaller devices are required as well as thermally stable devices, and multiple wavelength channels. In turn this demands smaller, more efficient modulators, athermal circuits, and improved wavelength division multiplexers. The debate continues as to whether on-chip lasers are necessary for all applications, but an efficient low cost laser would benefit many applications. Multi-layer photonics offers the possibility of increasing the complexity and effectiveness of a given area of chip real estate, but it is a demanding challenge. Low cost packaging (in particular, passive alignment of fibre to waveguide), and effective wafer scale testing strategies, are also essential for mass market applications. Whilst solutions to these challenges would enhance most applications, a derivative technology is emerging, that of Mid Infra-Red (MIR) silicon photonics. This field will build on existing developments, but will require key enhancements to facilitate functionality at longer wavelengths. In common with mainstream silicon photonics, significant developments have been made, but there is still much left to do. Here we summarise some of our recent work towards wafer scale testing, passive alignment, multiplexing, and MIR silicon photonics technology.

  14. Silicon nanostructures for photonics

    International Nuclear Information System (INIS)

    Nanostructuring silicon is an effective way to turn silicon into a photonic material. In fact, low-dimensional silicon shows light amplification characteristics, non-linear optical effects, photon confinement in both one and two dimensions, photon trapping with evidence of light localization, and gas-sensing properties. (author)

  15. Silicon: electrochemistry and luminescence

    NARCIS (Netherlands)

    Kooij, Ernst Stefan

    2001-01-01

    The electrochemistry of crystalline and porous silicon and the luminescence from porous silicon has been studied. One chapter deals with a model for the anodic dissolution of silicon in HF solution. In following chapters both the electrochemistry and various ways of generating visible luminescenc

  16. Approach to make macroporous metal sheets as current collectors for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Wu; Canfield, Nathan L.; Wang, Deyu; Xiao, Jie; Nie, Zimin; Li, Xiaohong S.; Bennett, Wendy D.; Bonham, Charles C.; Zhang, Jiguang

    2010-05-05

    A new approach and simple method is described to produce macroporous metal sheet as current collector for anode in lithium ion battery. This method, based on slurry blending, tape casting, sintering, and reducing of metal oxides, produces a uniform, macroporous metal sheet. Silicon film sputter-coated on such porous copper substrate shows much higher capacity and longer cycle life than on smooth Cu foil. This methodology produces very limited wastes and is also adaptable to many other materials. It is easy for industrial scale production.

  17. Sensitivity analysis of the add-on price estimate for the silicon web growth process

    Science.gov (United States)

    Mokashi, A. R.

    1981-01-01

    The web growth process, a silicon-sheet technology option, developed for the flat plate solar array (FSA) project, was examined. Base case data for the technical and cost parameters for the technical and commercial readiness phase of the FSA project are projected. The process add on price, using the base case data for cost parameters such as equipment, space, direct labor, materials and utilities, and the production parameters such as growth rate and run length, using a computer program developed specifically to do the sensitivity analysis with improved price estimation are analyzed. Silicon price, sheet thickness and cell efficiency are also discussed.

  18. Plasma enhanced deposition of 'silicon nitride' for use as an encapsulant for silicon ion-implanted gallium arsenide

    International Nuclear Information System (INIS)

    Silicon nitride films have been produced by plasma enhanced chemical vapour deposition using silane and ammonia as the reactant gases in a Plasma-Therm PK1250PD machine. The compositions of the films have been investigated as a function of the silane to ammonia flow rate ratio used for deposition, using infra-red transmission and Auger electron spectroscopies. These techniques indicated that the plasma deposited films were silicon-rich and contained hydrogen. The oxygen content of the films was below the detection limit of Auger electron spectroscopy implying that it was less than 1%. Silicon ion-implanted semi-insulating gallium arsenide has been annealed using an approximately 1000 A thick film of plasma deposited silicon nitride as an encapsulant. This capped annealing technique has achieved 70% activations of 4 x 1012 cm-2, 200 keV silicon implants with sheet Hall mobilities of 4000 cm2 V-1 s-1 at room temperature. Free carrier concentration and Hall mobility profiles are presented. Unimplanted semi-insulating gallium arsenide samples have also been capped annealed in the same manner and maintained a sheet resistivity of greater than 107 Ω/square after annealing. (author)

  19. A new approach to nanoporous graphene sheets via rapid microwave-induced plasma for energy applications

    International Nuclear Information System (INIS)

    We developed a novel approach to the fabrication of three-dimensional, nanoporous graphene sheets featuring a high specific surface area of 734.9 m2 g−1 and an ultrahigh pore volume of 4.1 cm3 g−1 through a rapid microwave-induced plasma treatment. The sheets were used as electrodes for supercapacitors and for the oxygen reduction reaction (ORR) for fuel cells. Argon-plasma grown sheets exhibited a 44% improvement of supercapacitive performance (203 F g−1) over the plasma grown sheets (141 F g−1). N-doped sheets with Co3O4 showed an outstanding ORR activity evidenced from the much smaller Tafel slope (42 mV/decade) than that of Pt/C (82 mV/decade), which is caused by the high electrical conductivity of the graphene sheets, the planar N species content and the nanoporous morphology. (paper)

  20. NC INCREMENTAL SHEET METAL FORMING PROCESS AND VERTICAL WALL SQUARE BOX FORMING

    Institute of Scientific and Technical Information of China (English)

    Zhou Liuru; Mo Jianhua; Xiao Xiangzhi

    2004-01-01

    The forming principle and deformation analysis of NC incremental sheet metal forming process as well as the process planning, experiment and key process parameters of vertical wall square box forming are presented. Because the deformation of sheet metal only occurs around the tool head and the deformed region is subjected to stretch deformation, the deformed region of sheet metal thins, and surface area increases. Sheet metal forming stepwise is to lead to the whole sheet metal deformation. The forming half-apex angle θ and corner radius R are the main process parameters in NC incremental forming of vertical wall square box. According to sine law, a vertical wall square box can't be formed by NC incremental sheet metal forming process in a single process, rather, it must be formed in multi processes. Thus, the parallel line type tool path process method is presented to form the vertical wall square box, and the experiment and analysis are made to verify it.

  1. A new approach to nanoporous graphene sheets via rapid microwave-induced plasma for energy applications.

    Science.gov (United States)

    Odedairo, Taiwo; Ma, Jun; Gu, Yi; Zhou, Wei; Jin, Jian; Zhao, X S; Zhu, Zhonghua

    2014-12-12

    We developed a novel approach to the fabrication of three-dimensional, nanoporous graphene sheets featuring a high specific surface area of 734.9 m(2) g(-1) and an ultrahigh pore volume of 4.1 cm(3) g(-1) through a rapid microwave-induced plasma treatment. The sheets were used as electrodes for supercapacitors and for the oxygen reduction reaction (ORR) for fuel cells. Argon-plasma grown sheets exhibited a 44% improvement of supercapacitive performance (203 F g(-1)) over the plasma grown sheets (141 F g(-1)). N-doped sheets with Co3O4 showed an outstanding ORR activity evidenced from the much smaller Tafel slope (42 mV/decade) than that of Pt/C (82 mV/decade), which is caused by the high electrical conductivity of the graphene sheets, the planar N species content and the nanoporous morphology. PMID:25410325

  2. The chemistry of silicon

    CERN Document Server

    Rochow, E G; Emeléus, H J; Nyholm, Ronald

    1975-01-01

    Pergamon Texts in Organic Chemistry, Volume 9: The Chemistry of Silicon presents information essential in understanding the chemical properties of silicon. The book first covers the fundamental aspects of silicon, such as its nuclear, physical, and chemical properties. The text also details the history of silicon, its occurrence and distribution, and applications. Next, the selection enumerates the compounds and complexes of silicon, along with organosilicon compounds. The text will be of great interest to chemists and chemical engineers. Other researchers working on research study involving s

  3. Automobile sheet metal part production with incremental sheet forming

    Directory of Open Access Journals (Sweden)

    İsmail DURGUN

    2016-02-01

    Full Text Available Nowadays, effect of global warming is increasing drastically so it leads to increased interest on energy efficiency and sustainable production methods. As a result of adverse conditions, national and international project platforms, OEMs (Original Equipment Manufacturers, SMEs (Small and Mid-size Manufacturers perform many studies or improve existing methodologies in scope of advanced manufacturing techniques. In this study, advanced manufacturing and sustainable production method "Incremental Sheet Metal Forming (ISF" was used for sheet metal forming process. A vehicle fender was manufactured with or without die by using different toolpath strategies and die sets. At the end of the study, Results have been investigated under the influence of method and parameters used.Keywords: Template incremental sheet metal, Metal forming

  4. Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers

    Directory of Open Access Journals (Sweden)

    J. E. Box

    2012-08-01

    Full Text Available Greenland ice sheet mass loss has accelerated in the past decade responding to combined glacier discharge and surface melt water runoff increases. During summer, absorbed solar energy, modulated at the surface primarily by albedo, is the dominant factor governing surface melt variability in the ablation area. Using satellite-derived surface albedo with calibrated regional climate modeled surface air temperature and surface downward solar irradiance, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback over 12 summer periods beginning in 2000. We find that, while albedo feedback defined by the change in net solar shortwave flux and temperature over time is positive over 97% of the ice sheet, when defined using paired annual anomalies, a second-order negative feedback is evident over 63% of the accumulation area. This negative feedback damps the accumulation area response to warming due to a positive correlation between snowfall and surface air temperature anomalies. Positive anomaly-gauged feedback concentrated in the ablation area accounts for more than half of the overall increase in melting when satellite-derived melt duration is used to define the timing when net shortwave flux is sunk into melting. Abnormally strong anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007, enabled three amplifying mechanisms to maximize the albedo feedback: (1 increased warm (south air advection along the western ice sheet increased surface sensible heating that in turn enhanced snow grain metamorphic rates, further reducing albedo; (2 increased surface downward shortwave flux, leading to more surface heating and further albedo reduction; and (3 reduced snowfall rates sustained low albedo, maximizing surface solar heating, progressively lowering albedo over multiple years. The summer net infrared and solar radiation for the high elevation accumulation area approached

  5. Stress studies in edge-defined film-fed growth of silicon ribbons

    Science.gov (United States)

    Kalejs, J.

    1985-01-01

    Stress and efficiency studies on sheet silicon are reported. It was found that the bulk diffusion length of stressed float zone and Czochralski silicon is limited by point defect recombination to about 20 micrometers in dislocation free regions after high temperature heat treatment and stress application. If in-diffusion by iron occurs, dislocations, carbon and oxygen, do not produce significant gettering with annealing. Further work ideas are suggested.

  6. Computational Science Guides and Accelerates Hydrogen Research (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2010-12-01

    This fact sheet describes NREL's accomplishments in using computational science to enhance hydrogen-related research and development in areas such as storage and photobiology. Work was performed by NREL's Chemical and Materials Science Center and Biosciences Center.

  7. Chemical Analysis Methods for Silicon Carbide

    Institute of Scientific and Technical Information of China (English)

    Shen Keyin

    2006-01-01

    @@ 1 General and Scope This Standard specifies the determination method of silicon dioxide, free silicon, free carbon, total carbon, silicon carbide, ferric sesquioxide in silicon carbide abrasive material.

  8. Guide for waste profile sheets

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-09-15

    This waste profile sheet was prepared to help petroleum industry operators properly classify and handle industrial waste. The profile sheets complied with British Columbia (BC) occupational health and safety regulations. Waste sheets were provided for compressed gases; flammable and combustible materials; oxidizing materials; poisonous materials; toxic materials; biohazardous and infectious materials; corrosive materials; and dangerously reactive materials. The waste information sheets were divided into 4 sections: (1) general information, (2) hazard information, (3) management methods, and (4) transportation. Sheets were provided for absorbents and rags; acids; batteries; carbon-amine; carbon-glycol; flammable and self-heating carbon; metal catalysts; caustic materials; contaminated debris; desiccant materials; drill sump materials; filters; raw gas fluids; frac fluids; hydrotest fluids; incinerator ashes; lubricating oils; PCBs; pigging wax; various sludges; solvent residues; process water; and well workover fluids. Detailed information on the handling, storage and disposal of the wastes was provided, as well as information related to reportable releases, required labels and placards, and documentation related to hazardous waste shipment. tabs., figs.

  9. Uranium mining sites - Thematic sheets

    International Nuclear Information System (INIS)

    A first sheet proposes comments, data and key numbers about uranium extraction in France: general overview of uranium mining sites, status of waste rock and tailings after exploitation, site rehabilitation. The second sheet addresses the sources of exposure to ionizing radiations due to ancient uranium mining sites: discussion on the identification of these sources associated with these sites, properly due to mining activities or to tailings, or due to the transfer of radioactive substances towards water and to the contamination of sediments, description of the practice and assessment of radiological control of mining sites. A third sheet addresses the radiological exposure of public to waste rocks, and the dose assessment according to exposure scenarios: main exposure ways to be considered, studied exposure scenarios (passage on backfilled path and grounds, stay in buildings built on waste rocks, keeping mineralogical samples at home). The fourth sheet addresses research programmes of the IRSN on uranium and radon: epidemiological studies (performed on mine workers; on French and on European cohorts, French and European studies on the risk of lung cancer associated with radon in housing), study of the biological effects of chronic exposures. The last sheet addresses studies and expertises performed by the IRSN on ancient uranium mining sites in France: studies commissioned by public authorities, radioactivity control studies performed by the IRSN about mining sites, participation of the IRSN to actions to promote openness to civil society

  10. Mechanically flexible optically transparent silicon fabric with high thermal budget devices from bulk silicon (100)

    Science.gov (United States)

    Hussain, Muhammad M.; Rojas, Jhonathan P.; Torres Sevilla, Galo A.

    2013-05-01

    Today's information age is driven by silicon based electronics. For nearly four decades semiconductor industry has perfected the fabrication process of continuingly scaled transistor - heart of modern day electronics. In future, silicon industry will be more pervasive, whose application will range from ultra-mobile computation to bio-integrated medical electronics. Emergence of flexible electronics opens up interesting opportunities to expand the horizon of electronics industry. However, silicon - industry's darling material is rigid and brittle. Therefore, we report a generic batch fabrication process to convert nearly any silicon electronics into a flexible one without compromising its (i) performance; (ii) ultra-large-scale-integration complexity to integrate billions of transistors within small areas; (iii) state-of-the-art process compatibility, (iv) advanced materials used in modern semiconductor technology; (v) the most widely used and well-studied low-cost substrate mono-crystalline bulk silicon (100). In our process, we make trenches using anisotropic reactive ion etching (RIE) in the inactive areas (in between the devices) of a silicon substrate (after the devices have been fabricated following the regular CMOS process), followed by a dielectric based spacer formation to protect the sidewall of the trench and then performing an isotropic etch to create caves in silicon. When these caves meet with each other the top portion of the silicon with the devices is ready to be peeled off from the bottom silicon substrate. Release process does not need to use any external support. Released silicon fabric (25 μm thick) is mechanically flexible (5 mm bending radius) and the trenches make it semi-transparent (transparency of 7%).

  11. Mechanically flexible optically transparent silicon fabric with high thermal budget devices from bulk silicon (100)

    KAUST Repository

    Hussain, Muhammad Mustafa

    2013-05-30

    Today’s information age is driven by silicon based electronics. For nearly four decades semiconductor industry has perfected the fabrication process of continuingly scaled transistor – heart of modern day electronics. In future, silicon industry will be more pervasive, whose application will range from ultra-mobile computation to bio-integrated medical electronics. Emergence of flexible electronics opens up interesting opportunities to expand the horizon of electronics industry. However, silicon – industry’s darling material is rigid and brittle. Therefore, we report a generic batch fabrication process to convert nearly any silicon electronics into a flexible one without compromising its (i) performance; (ii) ultra-large-scale-integration complexity to integrate billions of transistors within small areas; (iii) state-of-the-art process compatibility, (iv) advanced materials used in modern semiconductor technology; (v) the most widely used and well-studied low-cost substrate mono-crystalline bulk silicon (100). In our process, we make trenches using anisotropic reactive ion etching (RIE) in the inactive areas (in between the devices) of a silicon substrate (after the devices have been fabricated following the regular CMOS process), followed by a dielectric based spacer formation to protect the sidewall of the trench and then performing an isotropic etch to create caves in silicon. When these caves meet with each other the top portion of the silicon with the devices is ready to be peeled off from the bottom silicon substrate. Release process does not need to use any external support. Released silicon fabric (25 μm thick) is mechanically flexible (5 mm bending radius) and the trenches make it semi-transparent (transparency of 7%). © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  12. Electrical and physical properties of light pulse and thermally annealed polycrystalline silicon films

    International Nuclear Information System (INIS)

    A detailed study of electrical and physical properties of ion implanted polysilicon layers processed with large-area radiation sources at different times and temperatures is given. The samples used for these studies were 350 nm thick polysilicon films deposited by LPCVD-process at 625 0C on thermally grown silicon dioxide layers. The films were implanted with either 50 keV 31P+ or 75As+ ions with dose levels between 5 x 1015 and 2.5 x 1016 ions/cm2. To activate the dopant atoms, the samples were then annealed in air by irradiation with either flash lamps (typically 10 ms) or a halogen lamp system (typically 10 s). In order to compare the effect of the different annealing techniques, a set of samples was furnace annealed at different temperatures for 30 min in a nitrogen atmosphere. The electrical and physical properties, and the limit of reducing the sheet resistivity have been investigated by a systematic study of carrier concentration, carrier mobility, dopant distribution and grain sizes using Hall-effect measurements, transmission electron microscopy, SIMS and RBS measurements. The experiments show, that the lowest sheet resistivity values of 8.5 Ohm/cm2 and 19 Ohm/cm2 for P and As, respectively, could be obtained after annealing at 1200 0C for 10 s. This is due to both an enhanced grain growth up to 1 μm and a negligible outdiffusion of dopant atoms. (author)

  13. Late Weichselian ice sheet of Northern Eurasia

    Science.gov (United States)

    Grosswald, M. G.

    1980-01-01

    A considerable portion of Northern Eurasia, and particularly its continental shelf, was glaciated by inland ice during late Weichsel time. This was first inferred from such evidence as glacial striae, submarine troughs, sea-bed diamictons, boulder trains on adjacent land, and patterns of glacioisostatic crustal movements. Subsequently, the inference was confirmed by data on the occurrence and geographic position of late Weichselian end moraines and proglacial lacustrine deposits. The south-facing outer moraines in the northeastern Russian Plain, northern West Siberia, and on Taimyr Peninsula are underlain by sediments containing wood and peat, the radiocarbon dating of which yielded ages of 22,000 to 45,000 yr B.P. The youngest late-glacial moraines are of Holocene age: the double Markhida moraine in the lower Pechora River basin, presumably associated with "degradational" surges of the Barents Ice Dome, is underlain by sediments with wood and peat dated at 9000 to 9900 yr B.P.: this suggests that deglaciation of the Arctic continental shelf of Eurasia was not completed until after 9000 yr B.P. The reconstructed ice-front lines lead to the conclusion that the late Weichselian ice sheet of Northern Eurasia (proposed name: the Eurasian Ice Sheet) extended without interruptions from southwestern Ireland to the northeastern end of Taimyr Peninsula, a distance of 6000 km: it covered an area of 8,370,000 km 2, half of which lay on the present-day continental shelves and a quarter on lowlands that were depressed isostatically below sea level. Hence, the ice sheet was predominantly marine-based. A contour map of the ice sheet based both on the dependence of the heights of ice domes upon their radii and on factual data concerning the impact of bedrock topography upon ice relief has been constructed. The major features of the ice sheet were the British, Scandinavian, Barents, and Kara Ice Domes that had altitudes of 1.9 to 3.3 km and were separated from one another by ice

  14. Solution-processed polycrystalline silicon on paper

    Science.gov (United States)

    Trifunovic, M.; Shimoda, T.; Ishihara, R.

    2015-04-01

    Printing electronics has led to application areas which were formerly impossible with conventional electronic processes. Solutions are used as inks on top of large areas at room temperatures, allowing the production of fully flexible circuitry. Commonly, research in these inks have focused on organic and metal-oxide ink materials due to their printability, while these materials lack in the electronic performance when compared to silicon electronics. Silicon electronics, on the other hand, has only recently found their way in solution processes. Printing of cyclopentasilane as the silicon ink has been conducted and devices with far superior electric performance have been made when compared to other ink materials. A thermal annealing step of this material, however, was necessary, which prevented its usage on inexpensive substrates with a limited thermal budget. In this work, we introduce a method that allows polycrystalline silicon (poly-Si) production directly from the same liquid silicon ink using excimer laser irradiation. In this way, poly-Si could be formed directly on top of paper even with a single laser pulse. Using this method, poly-Si transistors were created at a maximum temperature of only 150 °C. This method allows silicon device formation on inexpensive, temperature sensitive substrates such as polyethylene terephthalate, polyethylene naphthalate or paper, which leads to applications that require low-cost but high-speed electronics.

  15. Solution-processed polycrystalline silicon on paper

    Energy Technology Data Exchange (ETDEWEB)

    Trifunovic, M.; Ishihara, R., E-mail: r.ishihara@tudelft.nl [Delft Institute for Microsystems and Nanoelectronics (DIMES), Delft University of Technology, Feldmannweg 17, 2628CT Delft (Netherlands); Shimoda, T. [Japan Advanced Institute of Science and Technology, Nomi, Ishikawa 923-1292 (Japan)

    2015-04-20

    Printing electronics has led to application areas which were formerly impossible with conventional electronic processes. Solutions are used as inks on top of large areas at room temperatures, allowing the production of fully flexible circuitry. Commonly, research in these inks have focused on organic and metal-oxide ink materials due to their printability, while these materials lack in the electronic performance when compared to silicon electronics. Silicon electronics, on the other hand, has only recently found their way in solution processes. Printing of cyclopentasilane as the silicon ink has been conducted and devices with far superior electric performance have been made when compared to other ink materials. A thermal annealing step of this material, however, was necessary, which prevented its usage on inexpensive substrates with a limited thermal budget. In this work, we introduce a method that allows polycrystalline silicon (poly-Si) production directly from the same liquid silicon ink using excimer laser irradiation. In this way, poly-Si could be formed directly on top of paper even with a single laser pulse. Using this method, poly-Si transistors were created at a maximum temperature of only 150 °C. This method allows silicon device formation on inexpensive, temperature sensitive substrates such as polyethylene terephthalate, polyethylene naphthalate or paper, which leads to applications that require low-cost but high-speed electronics.

  16. Solution-processed polycrystalline silicon on paper

    International Nuclear Information System (INIS)

    Printing electronics has led to application areas which were formerly impossible with conventional electronic processes. Solutions are used as inks on top of large areas at room temperatures, allowing the production of fully flexible circuitry. Commonly, research in these inks have focused on organic and metal-oxide ink materials due to their printability, while these materials lack in the electronic performance when compared to silicon electronics. Silicon electronics, on the other hand, has only recently found their way in solution processes. Printing of cyclopentasilane as the silicon ink has been conducted and devices with far superior electric performance have been made when compared to other ink materials. A thermal annealing step of this material, however, was necessary, which prevented its usage on inexpensive substrates with a limited thermal budget. In this work, we introduce a method that allows polycrystalline silicon (poly-Si) production directly from the same liquid silicon ink using excimer laser irradiation. In this way, poly-Si could be formed directly on top of paper even with a single laser pulse. Using this method, poly-Si transistors were created at a maximum temperature of only 150 °C. This method allows silicon device formation on inexpensive, temperature sensitive substrates such as polyethylene terephthalate, polyethylene naphthalate or paper, which leads to applications that require low-cost but high-speed electronics

  17. Sampling Artifacts from Conductive Silicone Tubing

    Energy Technology Data Exchange (ETDEWEB)

    Timko, Michael T.; Yu, Zhenhong; Kroll, Jesse; Jayne, John T.; Worsnop, Douglas R.; Miake-Lye, Richard C.; Onasch, Timothy B.; Liscinsky, David; Kirchstetter, Thomas W.; Destaillats, Hugo; Holder, Amara L.; Smith, Jared D.; Wilson, Kevin R.

    2009-05-15

    We report evidence that carbon impregnated conductive silicone tubing used in aerosol sampling systems can introduce two types of experimental artifacts: 1) silicon tubing dynamically absorbs carbon dioxide gas, requiring greater than 5 minutes to reach equilibrium and 2) silicone tubing emits organic contaminants containing siloxane that adsorb onto particles traveling through it and onto downstream quartz fiber filters. The consequence can be substantial for engine exhaust measurements as both artifacts directly impact calculations of particulate mass-based emission indices. The emission of contaminants from the silicone tubing can result in overestimation of organic particle mass concentrations based on real-time aerosol mass spectrometry and the off-line thermal analysis of quartz filters. The adsorption of siloxane contaminants can affect the surface properties of aerosol particles; we observed a marked reduction in the water-affinity of soot particles passed through conductive silicone tubing. These combined observations suggest that the silicone tubing artifacts may have wide consequence for the aerosol community and should, therefore, be used with caution. Gentle heating, physical and chemical properties of the particle carriers, exposure to solvents, and tubing age may influence siloxane uptake. The amount of contamination is expected to increase as the tubing surface area increases and as the particle surface area increases. The effect is observed at ambient temperature and enhanced by mild heating (<100 oC). Further evaluation is warranted.

  18. Microstructure Control of Columnar-Grained Silicon Substrate Solidified from Silicon Melts Using Gas Pressure

    Directory of Open Access Journals (Sweden)

    Jun-Kyu Lee

    2015-01-01

    Full Text Available A silicon substrate with the dimensions of 100 × 140 × 0.3 mm was grown directly from liquid silicon with gas pressure. The silicon melt in the sealed melting part was injected into the growth part at applied pressure of 780–850 Torr. The solidified silicon substrate was then transferred by the pull of the cooled dummy bar. A desirable structure with a liquid-solid interface perpendicular to the pulling direction was formed when the mold temperature in the solidification zone of the growth part was much higher than that of the dummy bar, as this technique should be able to overcome thermal loss through the molds and the limited heat flux derived from the very narrow contact area between the silicon melt and the dummy bar. In addition, because the metallic impurities and expansion of volume during solidification are preferably moved to a liquid phase, a high-quality silicon substrate, without defects such as cracks and impurities in the substrate, could be manufactured in the interface structure. The present study reports the experimental findings on a new and direct growth system for obtaining silicon substrates characterized by high quality and productivity, as a candidate for alternate routes for the fabrication of silicon substrates.

  19. Statistical research on the motion properties of the magnetotail current sheet:Cluster observations

    Institute of Scientific and Technical Information of China (English)

    H.REME; E.LUCEK

    2010-01-01

    The origin of the flapping motion of the earth’s magnetotail current sheet is one of the most important problems in the magnetotail dynamics.Using Cluster data,we make a statistical research on the motion properties of the magnetotail current sheet of 2001 and 2003.We calculate the velocities of the magnetotail current sheet using new methods and obtain the distribution of the magnetotail current sheet velocities in the X-Y plane in GSE coordinate system.Our results show that although most of the current sheets were propagating toward the tail flanks and those of the exceptions lay in dusk side,which is consistent with previous studies,the proportions of the current sheet which were propagating toward midnight (where |YGSE|=0) were higher than those in previous studies.Motions of the current sheet in the middle area (|YGSE|<8 Re) of the magnetotail are investigated.Relatively high value of the Z component of the velocity further confirms that the middle area of the magnetotail might be a source region for the motion of the current sheets which were propagating towards the tail flanks.According to our case studies,the way the current sheets propagated toward midnight area differs significantly from that toward dusk and dawn side,from which we infer that there might be two different kinds of current sheet motions originated from different sources.The statistical results of this paper may give some clues for further studies on the origin of the flapping motion of the magnetotail current sheet.

  20. A probabilistic analysis of silicon cost

    Science.gov (United States)

    Reiter, L. J.

    1983-01-01

    Silicon materials costs represent both a cost driver and an area where improvement can be made in the manufacture of photovoltaic modules. The cost from three processes for the production of low-cost silicon being developed under the U.S. Department of Energy's (DOE) National Photovoltaic Program is analyzed. The approach is based on probabilistic inputs and makes use of two models developed at the Jet Propulsion Laboratory: SIMRAND (SIMulation of Research ANd Development) and IPEG (Improved Price Estimating Guidelines). The approach, assumptions, and limitations are detailed along with a verification of the cost analyses methodology. Results, presented in the form of cumulative probability distributions for silicon cost, indicate that there is a 55% chance of reaching the DOE target of $16/kg for silicon material. This is a technically achievable cost based on expert forecasts of the results of ongoing research and development and do not imply any market prices for a given year.

  1. One-sheet spiraling full thickness skin graft for penile resurfacing after paraffinoma excision

    Directory of Open Access Journals (Sweden)

    Theddeus O.H. Prasetyono

    2011-08-01

    Full Text Available In the midst of on-going non-illicit practice of silicone or paraffin injection to enlarge penis, the author reported 3 cases of surgical treatment to resurface the body of the penis after excision of the destructed penile skin using full thickness skin graft. The skin excision was performed technically through penile body degloving procedure. Full thickness skin graft was then applied as a single sheet donor tissue to cover the denuded penile body spirally. The full thickness graft, which is relatively easy to be performed, is no doubt much thinner than a skin flap, while it also bears a smaller degree of secondary contraction than split skin graft. The color of the skin is considerably matched as it comes from the groin, which is a nearby area of penis. The size and skin sensitization of the penis looks to be natural. The only disadvantage is the common possibility of either spiral or circular junctional scar in between graft edges and between the graft and the penile mucosa and skin to develop hypertrophic scar. However, this possible scar problem applies also to any other surgical scar with any donor tissue. Fortunately, the 3 cases posed no scar problem and normal appearance. All the patients have also regained their normal sexual function. (Med J Indones 2011; 20:222-5Keywords: full thickness skin graft, paraffinoma, siliconoma, sexual function

  2. Greenland Ice sheet mass balance from satellite and airborne altimetry

    OpenAIRE

    Khan, Shfaqat Abbas; Bevis, M. G.; Wahr, J. M.; Wouters, B.; Sasgen, I.; van Dam, T. M.; Van Den Broeke, M. R.; Hanna, E; Huybrechts, P.; Kjaer, K. H.; N. J. Korsgaard; Bjork, A. A.; Kjeldsen, K.K.

    2013-01-01

    Ice loss from the Greenland Ice Sheet (GrIS) is dominated by loss in the marginal areas. Dynamic induced ice loss and its associated ice surface lowering is often largest close to the glacier calving front and may vary from rates of tens of meters per years to a few meters per year over relatively short distances. Hence, high spatial resolution data are required to accurately estimate volume changes. Here, we estimate ice volume change rate of the Greenland ice sheet using data from Ice, Clou...

  3. Tunable silicon CROW delay lines

    Science.gov (United States)

    Morichetti, Francesco; Canciamilla, Antonio; Torregiani, Matteo; Ferrari, Carlo; Melloni, Andrea; Martinelli, Mario

    2010-05-01

    Tunable coupled resonator optical waveguides (CROWs) are powerful and versatile devices that can be used to dynamically control the delay of optical data streams on chip. In this contribution we show that CROW delay lines fabricated on a silicon on insulator (SOI) platform are suitable for applications in the emerging scenario of optical systems at 100 Gbit/s. Issues concerning technology, design, limits and applications of SOI CROWs are discussed. The performances of silicon CROW delay lines activated by thermal tuning are compared to those of glass CROW in terms of power consumption, thermal crosstalk and reconfiguration speed. The continuous delay of 10-ps long optical pulses by 8 bit length is demonstrated by using a silicon CROW with a bandwidth of 87 GHz and made of 12 RRs. At 100 Gbit/s this structure provides comparable figures of merit (fractional delay of 0.75 bit/RR and fractional loss of 0.7 dB per bit-delay) of state-of-the art glass CROW operating at 10 Gbit/s, yet the area of the latter being three order of magnitude larger. The compatibility of silicon CROW with the emerging 100 Gbit/s systems is demonstrated by showing error-free phase-preserving propagation of a 100 Gbit/s return-to-zero (RZ) polarization-division-multiplexing (PolDM) differential quaternary phase shit keying (DQPSK) signal dynamically delayed by the CROW. It is also demonstrated that a silicon CROW can be used in a PolDM system to introduce a polarization selective delay in order to optimize the time interleaving of the two orthogonally polarized data streams.

  4. D0 Silicon Upgrade: D0 Silicon Cooling System

    International Nuclear Information System (INIS)

    The cooling system design is not complete. This paper lays out the general design and some of the design calculations that have been performed up to this date. Further refinement will be performed. This is especially true in the piping layout, piping insulation and detector manifold areas. The silicon detector is cooled by means of a coolant in the beryllium channels that also act as the primary supporting device for the silicon ladders and wedges. The coolant is water with ethylene glycol added as a freezing point depressant. The glycol concentration in the coolant is 30% by weight resulting in a freezing point of approximately -15 C. If the water/glycol is not sufficient for maintaining the desired detector temperature the concentration of the water/glycol may be changed or an alternative coolant may be used.

  5. Ice sheet hydrology - a review

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Peter; Naeslund, Jens-Ove [Dept. of Physical Geography and Quaternary Geology, Stockholm Univ., Stockholm (Sweden); Rodhe, Lars [Geological Survey of Sweden, Uppsala (Sweden)

    2007-03-15

    This report summarizes the theoretical knowledge on water flow in and beneath glaciers and ice sheets and how these theories are applied in models to simulate the hydrology of ice sheets. The purpose is to present the state of knowledge and, perhaps more importantly, identify the gaps in our understanding of ice sheet hydrology. Many general concepts in hydrology and hydraulics are applicable to water flow in glaciers. However, the unique situation of having the liquid phase flowing in conduits of the solid phase of the same material, water, is not a commonly occurring phenomena. This situation means that the heat exchange between the phases and the resulting phase changes also have to be accounted for in the analysis. The fact that the solidus in the pressure-temperature dependent phase diagram of water has a negative slope provides further complications. Ice can thus melt or freeze from both temperature and pressure variations or variations in both. In order to provide details of the current understanding of water flow in conjunction with deforming ice and to provide understanding for the development of ideas and models, emphasis has been put on the mathematical treatments, which are reproduced in detail. Qualitative results corroborating theory or, perhaps more often, questioning the simplifications made in theory, are also given. The overarching problem with our knowledge of glacier hydrology is the gap between the local theories of processes and the general flow of water in glaciers and ice sheets. Water is often channelized in non-stationary conduits through the ice, features which due to their minute size relative to the size of glaciers and ice sheets are difficult to incorporate in spatially larger models. Since the dynamic response of ice sheets to global warming is becoming a key issue in, e.g. sea-level change studies, the problems of the coupling between the hydrology of an ice sheet and its dynamics is steadily gaining interest. New work is emerging

  6. Sheet Beam Klystron Instability Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bane, K.L.F.; Jensen, A.; Li, Z.; Stupakov, G.; Adolphsen, C.; /SLAC

    2009-05-08

    Using the principle of energy balance we develop a 2D theory for calculating growth rates of instability in a two-cavity model of a sheet beam klystron. An important ingredient is a TE-like mode in the gap that also gives a longitudinal kick to the beam. When compared with a self-consistent particle-in-cell calculation, with sheet beam klystron-type parameters, agreement is quite good up to half the design current, 65 A; at full current, however, other, current-dependent effects come in and the results deviate significantly.

  7. Ice sheet hydrology - a review

    International Nuclear Information System (INIS)

    This report summarizes the theoretical knowledge on water flow in and beneath glaciers and ice sheets and how these theories are applied in models to simulate the hydrology of ice sheets. The purpose is to present the state of knowledge and, perhaps more importantly, identify the gaps in our understanding of ice sheet hydrology. Many general concepts in hydrology and hydraulics are applicable to water flow in glaciers. However, the unique situation of having the liquid phase flowing in conduits of the solid phase of the same material, water, is not a commonly occurring phenomena. This situation means that the heat exchange between the phases and the resulting phase changes also have to be accounted for in the analysis. The fact that the solidus in the pressure-temperature dependent phase diagram of water has a negative slope provides further complications. Ice can thus melt or freeze from both temperature and pressure variations or variations in both. In order to provide details of the current understanding of water flow in conjunction with deforming ice and to provide understanding for the development of ideas and models, emphasis has been put on the mathematical treatments, which are reproduced in detail. Qualitative results corroborating theory or, perhaps more often, questioning the simplifications made in theory, are also given. The overarching problem with our knowledge of glacier hydrology is the gap between the local theories of processes and the general flow of water in glaciers and ice sheets. Water is often channelized in non-stationary conduits through the ice, features which due to their minute size relative to the size of glaciers and ice sheets are difficult to incorporate in spatially larger models. Since the dynamic response of ice sheets to global warming is becoming a key issue in, e.g. sea-level change studies, the problems of the coupling between the hydrology of an ice sheet and its dynamics is steadily gaining interest. New work is emerging

  8. The social balance sheet 2005

    OpenAIRE

    Ph. Delhez; P. Heuse

    2006-01-01

    Each year, the National Bank examines the provisional results of the social balance sheets of Belgian enterprises. As the social balance sheets are not yet all available for 2005, the study is based on a limited population of enterprises, compiled according to the principle of a constant sample. This population is made up of 48,976 enterprises employing around 4,441,000 workers in 2005. The main results of the analysis are as follows. As an average, employment increased by 0.5 p.c. between 20...

  9. Coating of silicon pore optics

    DEFF Research Database (Denmark)

    Cooper-Jensen, Carsten P.; Ackermann, M.; Christensen, Finn Erland;

    2009-01-01

    For the International X-ray observatory (IXO), a mirror module with an effective area of 3 m2 at 1.25 keV and at least 0.65 m2 at 6 keV has to be realized. To achieve this goal, coated silicon pore optics has been developed over the last years. One of the challenges is to coat the Si plates and...... still to realize Si-Si bonding. It has been demonstrated that ribbed silicon plates can be produced and assembled into stacks. All previously work has been done using uncoated Si plates. In this paper we describe how to coat the ribbed Si plates with an Ir coating and a top C coating through a mask so...

  10. Note: Anodic bonding with cooling of heat-sensitive areas

    DEFF Research Database (Denmark)

    Vesborg, Peter Christian Kjærgaard; Olsen, Jakob Lind; Henriksen, Toke Riishøj;

    2010-01-01

    Anodic bonding of silicon to glass always involves heating the glass and device to high temperatures so that cations become mobile in the electric field. We present a simple way of bonding thin silicon samples to borosilicate glass by means of heating from the glass side while locally cooling heat......-sensitive areas from the silicon side. Despite the high thermal conductivity of silicon, this method allows a strong anodic bond to form just millimeters away from areas essentially at room temperature....

  11. Advancing a New Era of Energy Delivery in the West (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-11-01

    This 2-page fact sheet provides a high-level overview of the Western Area Power Administration's Transmission Infrastructure Program, including background, purpose, goals, eligibility criteria, and current projects.

  12. Fact sheet : Wilderness proposal : Rice Lake - Mille Lacs National Wildlife Refuges

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a fact sheet of information about the Rice Lake and Mille Lacs National wildlife Refuges. Pertinent information such as the area of the refuge,...

  13. A high Tc superconductor bolometer on a silicon nitride membrane

    OpenAIRE

    Sanchez, Stefan; Elwenspoek, Miko; Gui, Chengqun; Nivelle, de, M.J.M.E.; De, Vries; Korte, de, N.; Bruijn, Marcel P.; Wijnbergen, Jan J.; Michalke, Wolfgang; Steinbeiss, Erwin; Heidenblut, Torsten; Schwierzi, Bernard

    1998-01-01

    In this paper, we describe the design, fabrication, and performance of a high-Tc GdBa2Cu3O7-¿ superconductor bolometer positioned on a 2× 2-mm2 1-¿m-thick silicon nitride membrane. The bolometer structure has an effective area of 0.64 mm2 and was grown on a specially developed silicon-on-nitride (SON) layer. This layer was made by direct bonding of silicon nitride to silicon after chemical mechanical polishing. The operation temperature of the bolometer is 85 K. A thermal conductance G=3.3·10...

  14. A high-Tc superconductor bolometer on a silicon nitridemembrane

    OpenAIRE

    Sanchez, S.; Elwenspoek, M.C.; Gui, C; Nivelle, de, M.J.M.E.; De, Vries; Korte, de, N.; Bruijn, M.P.; Schwierzi, B.

    1997-01-01

    In this paper we describe the design, fabrication and performance of a high-Tc GdBa2Cu3O7-δ superconductor bolometer positioned on a 2×2 mm2, 1 μm thick silicon nitride membrane. The bolometer structure has an effective area of 0.64 mm2 and was grown on a specially developed silicon-on-nitride layer. This layer was made by direct bonding of silicon nitride to silicon after chemical mechanical polishing. The operation temperature of the bolometer is 85 K. A thermal conductance G=3.3·10-5 W/K w...

  15. Magnetic Resonance Facility (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-03-01

    This fact sheet provides information about Magnetic Resonance Facility capabilities and applications at NREL's National Bioenergy Center. Liquid and solid-state analysis capability for a variety of biomass, photovoltaic, and materials characterization applications across NREL. NREL scientists analyze solid and liquid samples on three nuclear magnetic resonance (NMR) spectrometers as well as an electron paramagnetic resonance (EPR) spectrometer.

  16. Drinking Water Fact Sheet: Arsenic

    OpenAIRE

    Mesner, Nancy; Daniels, Barbara

    2010-01-01

    This fact sheet provides information about arsenic in drinking water. It includes sections about what arsenic is, where it comes from, health concerns from exposure, drinking water standards, how to know if there is arsenic in a water supply and how to reduce arsenic in drinking water.

  17. Learning from Balance Sheet Visualization

    Science.gov (United States)

    Tanlamai, Uthai; Soongswang, Oranuj

    2011-01-01

    This exploratory study examines alternative visuals and their effect on the level of learning of balance sheet users. Executive and regular classes of graduate students majoring in information technology in business were asked to evaluate the extent of acceptance and enhanced capability of these alternative visuals toward their learning…

  18. Climate Model Dependency and Understanding the Antarctic Ice Sheet during the Warm Late Pliocene

    Science.gov (United States)

    Dolan, Aisling; de Boer, Bas; Bernales, Jorge; Hunter, Stephen; Haywood, Alan

    2016-04-01

    In the context of future climate change, understanding the nature and behaviour of ice sheets during warm intervals of Earth history is fundamentally important. A warm period in the Late Pliocene (3.264 to 3.025 million years before present) can serve as a potential analogue for projected future climates. Although Pliocene ice locations and extents are still poorly constrained, a significant contribution to sea-level rise should be expected from both the Greenland ice sheet and the West and East Antarctic ice sheets based on palaeo sea-level reconstructions and geological evidence. Following a five year international project PLISMIP (Pliocene Ice Sheet Modeling Intercomparison Project) we present the final set of results which quantify uncertainty in climate model-based predictions of the Antarctic ice sheet. In this study we use an ensemble of climate model forcings within a multi-ice sheet model framework to assess the climate (model) dependency of large scale features of the Antarctic ice sheet. Seven coupled atmosphere-ocean climate models are used to derive surface temperature, precipitation and oceanic forcing that drive three ice sheet models (over the grounded and floating domain). Similar to results presented over Greenland, we show that the reconstruction of the Antarctic ice sheet is sensitive to which climate model is used to provide the forcing field. Key areas of uncertainty include West Antarctica, the large subglacial basins of East Antarctica and the overall thickness of the continental interior of East Antarctica. We relate the results back to geological proxy data, such as those relating to exposure rates which provide information on potential ice sheet thickness. Finally we discuss as to whether the choice of modelling framework (i.e. climate model and ice sheet model used) or the choice of boundary conditions causes the greatest uncertainty in ice sheet reconstructions of the warm Pliocene.

  19. Wafer-level integration of NiTi shape memory alloy on silicon using Au-Si eutectic bonding

    Science.gov (United States)

    Gradin, Henrik; Bushra, Sobia; Braun, Stefan; Stemme, Göran; van der Wijngaart, Wouter

    2013-01-01

    This paper reports on the wafer level integration of NiTi shape memory alloy (SMA) sheets with silicon substrates through Au-Si eutectic bonding. Different bond parameters, such as Au layer thicknesses and substrate surface treatments were evaluated. The amount of gold in the bond interface is the most important parameter to achieve a high bond yield; the amount can be determined by the barrier layers between the Au and Si or by the amount of Au deposition. Deposition of a gold layer of more than 1 μm thickness before bonding gives the most promising results. Through patterning of the SMA sheet and by limiting bonding to small areas, stresses created by the thermal mismatch between Si and NiTi are reduced. With a gold layer of 1 μm thickness and bond areas between 200 × 200 and 800 × 800 μm2 a high bond strength and a yield above 90% is demonstrated.

  20. Wafer-level integration of NiTi shape memory alloy on silicon using Au–Si eutectic bonding

    International Nuclear Information System (INIS)

    This paper reports on the wafer level integration of NiTi shape memory alloy (SMA) sheets with silicon substrates through Au–Si eutectic bonding. Different bond parameters, such as Au layer thicknesses and substrate surface treatments were evaluated. The amount of gold in the bond interface is the most important parameter to achieve a high bond yield; the amount can be determined by the barrier layers between the Au and Si or by the amount of Au deposition. Deposition of a gold layer of more than 1 μm thickness before bonding gives the most promising results. Through patterning of the SMA sheet and by limiting bonding to small areas, stresses created by the thermal mismatch between Si and NiTi are reduced. With a gold layer of 1 μm thickness and bond areas between 200 × 200 and 800 × 800 μm2 a high bond strength and a yield above 90% is demonstrated. (paper)

  1. Silicon containing copolymers

    CERN Document Server

    Amiri, Sahar; Amiri, Sanam

    2014-01-01

    Silicones have unique properties including thermal oxidative stability, low temperature flow, high compressibility, low surface tension, hydrophobicity and electric properties. These special properties have encouraged the exploration of alternative synthetic routes of well defined controlled microstructures of silicone copolymers, the subject of this Springer Brief. The authors explore the synthesis and characterization of notable block copolymers. Recent advances in controlled radical polymerization techniques leading to the facile synthesis of well-defined silicon based thermo reversible blo

  2. Highly porous silicon membranes fabricated from silicon nitride/silicon stacks.

    Science.gov (United States)

    Qi, Chengzhu; Striemer, Christopher C; Gaborski, Thomas R; McGrath, James L; Fauchet, Philippe M

    2014-07-23

    Nanopore formation in silicon films has previously been demonstrated using rapid thermal crystallization of ultrathin (15 nm) amorphous Si films sandwiched between nm-thick SiO2 layers. In this work, the silicon dioxide barrier layers are replaced with silicon nitride, resulting in nanoporous silicon films with unprecedented pore density and novel morphology. Four different thin film stack systems including silicon nitride/silicon/silicon nitride (NSN), silicon dioxide/silicon/silicon nitride (OSN), silicon nitride/silicon/silicon dioxide (NSO), and silicon dioxide/silicon/silicon dioxide (OSO) are tested under different annealing temperatures. Generally the pore size, pore density, and porosity positively correlate with the annealing temperature for all four systems. The NSN system yields substantially higher porosity and pore density than the OSO system, with the OSN and NSO stack characteristics fallings between these extremes. The higher porosity of the Si membrane in the NSN stack is primarily due to the pore formation enhancement in the Si film. It is hypothesized that this could result from the interfacial energy difference between the silicon/silicon nitride and silicon/silicon dioxide, which influences the Si crystallization process. PMID:24623562

  3. The CMS all-silicon tracker — strategies to ensure a high quality and radiation hard silicon detector

    Science.gov (United States)

    Hartmann, Frank

    2002-02-01

    In December 1999, the CMS collaboration decided to use an all-silicon solution for the tracker. In total the CMS tracker implements 24328 silicon sensors covering an area of 206 m 2. To control a large system of this size and ensure its functionality after 10 years under LHC condition, CMS developed an elaborate design and a detailed quality assurance program.

  4. Novel Silicon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Novel silicon nanotubes with inner-diameter of 60-80 nm was prepared using hydrogen-added dechlorination of SiCl4 followed by chemical vapor deposition (CVD) on a NixMgyO catalyst. The TEM observation showed that the suitable reaction temperature is 973 K for the formation of silicon nanotubes. Most of silicon nanotubes have one open end and some have two closed ends. The shape ofnanoscale silicon, however, is a micro-crystal type at 873 K, a rod or needle type at 993 K and an onion-type at 1023 K, respectively.

  5. Silicon nano-biotechnology

    CERN Document Server

    He, Yao

    2014-01-01

    This book reviews the latest advances in the development of silicon nano-biotechnology for biological and biomedical applications, which include biosensing, bioimaging, and cancer therapy. In this book, newly developed silicon nano-biotechnology and its biomedical applications are systematically introduced. For instance, fluorescent silicon nanoparticles, serving as novel high-performance biological nanoprobes, are superbly suited to real-time and long-term bioimaging. Silicon nanowire-based sensing platform is especially capable of sensitive, specific, and multiplexed detection of various bio

  6. Silicon-based metallic micro grid for electron field emission

    International Nuclear Information System (INIS)

    A micro-scale metal grid based on a silicon frame for application to electron field emission devices is introduced and experimentally demonstrated. A silicon lattice containing aperture holes with an area of 80 × 80 µm2 and a thickness of 10 µm is precisely manufactured by dry etching the silicon on one side of a double-polished silicon wafer and by wet etching the opposite side. Because a silicon lattice is more rigid than a pure metal lattice, a thin layer of Au/Ti deposited on the silicon lattice for voltage application can be more resistant to the geometric stress caused by the applied electric field. The micro-fabrication process, the images of the fabricated grid with 88% geometric transparency and the surface profile measurement after thermal feasibility testing up to 700 °C are presented. (paper)

  7. A Mechanochemical Approach to Porous Silicon Nanoparticles Fabrication

    Directory of Open Access Journals (Sweden)

    Luca De Stefano

    2011-06-01

    Full Text Available Porous silicon samples have been reduced in nanometric particles by a well known industrial mechanical process, the ball grinding in a planetary mill; the process has been extended to crystalline silicon for comparison purposes. The silicon nanoparticles have been studied by X-ray diffraction, infrared spectroscopy, gas porosimetry and transmission electron microscopy. We have estimated crystallites size from about 50 nm for silicon to 12 nm for porous silicon. The specific surface area of the powders analyzed ranges between 100 m2/g to 29 m2/g depending on the milling time, ranging from 1 to 20 h. Electron microscopy confirms the nanometric size of the particles and reveals a porous structure in the powders obtained by porous silicon samples which has been preserved by the fabrication conditions. Chemical functionalization during the milling process by a siloxane compound has also been demonstrated.

  8. Preparation and Characterization of Amorphous Silicon Oxide Nanowires

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Large-scale amorphous silicon nanowires (SiNWs) with a diameter about 100 nm and a length of dozens of micrometers on silicon wafers were synthesized by thermal evaporation of silicon monoxide (SiO).Scanning electron microscope (SEM) and transmission electron microscope (TEM) observations show that the silicon nanowires are smooth.Selected area electron diffraction (SAED) shows that the silicon nanowires are amorphous and energy-dispersive X-ray spectroscopy (EDS) indicates that the nanowires have the composition of Si and O elements in an atomic ratio of 1:2, their composition approximates that of SiO2.SiO is considered to be used as a Si sources to produce SiNWs.We conclude that the growth mechanism is closely related to the defect structure and silicon monoxide followed by growth through an oxide-assisted vapor-solid reaction.

  9. Orientational ordering in crumpled elastic sheets

    OpenAIRE

    Cambou, Anne Dominique; Menon, Narayanan

    2014-01-01

    We report an experimental study of the development of orientational order in a crumpled sheet, with a particular focus on the role played by the geometry of confinement. Our experiments are performed on elastomeric sheets immersed in a fluid, so that the effects of plasticity and friction are suppressed. When the sheet is crumpled either axially or radially within a cylinder, we find that the sheet aligns with the flat or the curved wall, depending on the aspect ratio of the cylinder. Nematic...

  10. Damping properties of silicone rubber/polyacrylate sequential interpenetrating networks

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-bing; HUANG Zhi-xiong; ZHANG Lian-meng

    2006-01-01

    Silicone rubber/polyacrylate sequential interpenetrating polymer networks(IPNs) were prepared by silicone rubber sheet dipped into the solution composed of different acrylate monomers and benzoyl peroxides(BPOs) for different time at room temperature and then acrylate polymerized at 80 ℃ for 2 h. The molecular structure and damping properties of sequential IPNs were studied by means of FT-IR and dynamic mechanical analysis(DMA),respectively. The FT-IR spectrum shows that polyacrylate distributes unevenly along the thickness direction of IPNs,i.e. the concentration of polyacrylate decreases from the midst to the surface of the IPNs. The DMA shows that cold crystallization of silicone in the temperature range from -47 ℃ to -30 ℃ is reduced and loss factor of IPNs is improved after interpenetrating with polyacrylate. This suggestes that IPNs can be used as damping materials.

  11. On the possible eigenoscillations of neutral sheets

    International Nuclear Information System (INIS)

    A neutral sheet model with hyperbolic tangent equilibrium magnetic field and hyperbolic square secant density profiles is considered. It is shown that the equation for small oscillations takes the form of an eigenvalue oscillation problem. Computed eigenfrequencies of the geomagnetic neutral sheet were found to be in the range of the resonant frequencies of the geomagnetic plasma sheet computed by other authors

  12. Photonic Crystal Sensors Based on Porous Silicon

    Directory of Open Access Journals (Sweden)

    Claudia Pacholski

    2013-04-01

    Full Text Available Porous silicon has been established as an excellent sensing platform for the optical detection of hazardous chemicals and biomolecular interactions such as DNA hybridization, antigen/antibody binding, and enzymatic reactions. Its porous nature provides a high surface area within a small volume, which can be easily controlled by changing the pore sizes. As the porosity and consequently the refractive index of an etched porous silicon layer depends on the electrochemial etching conditions photonic crystals composed of multilayered porous silicon films with well-resolved and narrow optical reflectivity features can easily be obtained. The prominent optical response of the photonic crystal decreases the detection limit and therefore increases the sensitivity of porous silicon sensors in comparison to sensors utilizing Fabry-Pérot based optical transduction. Development of porous silicon photonic crystal sensors which allow for the detection of analytes by the naked eye using a simple color change or the fabrication of stacked porous silicon photonic crystals showing two distinct optical features which can be utilized for the discrimination of analytes emphasize its high application potential.

  13. Predicting Two-Dimensional Silicon Carbide Monolayers.

    Science.gov (United States)

    Shi, Zhiming; Zhang, Zhuhua; Kutana, Alex; Yakobson, Boris I

    2015-10-27

    Intrinsic semimetallicity of graphene and silicene largely limits their applications in functional devices. Mixing carbon and silicon atoms to form two-dimensional (2D) silicon carbide (SixC1-x) sheets is promising to overcome this issue. Using first-principles calculations combined with the cluster expansion method, we perform a comprehensive study on the thermodynamic stability and electronic properties of 2D SixC1-x monolayers with 0 ≤ x ≤ 1. Upon varying the silicon concentration, the 2D SixC1-x presents two distinct structural phases, a homogeneous phase with well dispersed Si (or C) atoms and an in-plane hybrid phase rich in SiC domains. While the in-plane hybrid structure shows uniform semiconducting properties with widely tunable band gap from 0 to 2.87 eV due to quantum confinement effect imposed by the SiC domains, the homogeneous structures can be semiconducting or remain semimetallic depending on a superlattice vector which dictates whether the sublattice symmetry is topologically broken. Moreover, we reveal a universal rule for describing the electronic properties of the homogeneous SixC1-x structures. These findings suggest that the 2D SixC1-x monolayers may present a new "family" of 2D materials, with a rich variety of properties for applications in electronics and optoelectronics. PMID:26394207

  14. Large and fast reversible Li-ion storages in Fe2O3-graphene sheet-on-sheet sandwich-like nanocomposites

    OpenAIRE

    Jin Kan; Yong Wang

    2013-01-01

    Fe2O3 nanosheets and nanoparticles are grown on graphene by simply varying reaction solvents in a facile solvothermal/hydrothermal preparation. Fe2O3 nanosheets are uniformly dispersed among graphene nanosheets, forming a unique sheet-on-sheet nanostructure. Due to the structure affinity between two types of two dimensional nanostructures, graphene nanosheets are separated better by Fe2O3 nanosheets compared to nanoparticles and their agglomeration is largely prevented. A large surface area o...

  15. Geometry of thin liquid sheet flows

    Science.gov (United States)

    Chubb, Donald L.; Calfo, Frederick D.; Mcconley, Marc W.; Mcmaster, Matthew S.; Afjeh, Abdollah A.

    1994-01-01

    Incompresible, thin sheet flows have been of research interest for many years. Those studies were mainly concerned with the stability of the flow in a surrounding gas. Squire was the first to carry out a linear, invicid stability analysis of sheet flow in air and compare the results with experiment. Dombrowski and Fraser did an experimental study of the disintegration of sheet flows using several viscous liquids. They also detected the formulation of holes in their sheet flows. Hagerty and Shea carried out an inviscid stability analysis and calculated growth rates with experimental values. They compared their calculated growth rates with experimental values. Taylor studied extensively the stability of thin liquid sheets both theoretically and experimentally. He showed that thin sheets in a vacuum are stable. Brown experimentally investigated thin liquid sheet flows as a method of application of thin films. Clark and Dumbrowski carried out second-order stability analysis for invicid sheet flows. Lin introduced viscosity into the linear stability analysis of thin sheet flows in a vacuum. Mansour and Chigier conducted an experimental study of the breakup of a sheet flow surrounded by high-speed air. Lin et al. did a linear stability analysis that included viscosity and a surrounding gas. Rangel and Sirignano carried out both a linear and nonlinear invisid stability analysis that applies for any density ratio between the sheet liquid and the surrounding gas. Now there is renewed interest in sheet flows because of their possible application as low mass radiating surfaces. The objective of this study is to investigate the fluid dynamics of sheet flows that are of interest for a space radiator system. Analytical expressions that govern the sheet geometry are compared with experimental results. Since a space radiator will operate in a vacuum, the analysis does not include any drag force on the sheet flow.

  16. Surface activity of 137Cs, sheet 35 - Trnava

    International Nuclear Information System (INIS)

    In the predominantly geomorphologically mountainous terrain the map of surface activity of 137Cs was compiled from the results of exploration activities on scale 1:200 000 and in the Danube upland (between Povazsky Inovec and Little Carpathians) on scale 1:50 000. Surface activities of 137Cs are significantly unevenly distributed. The most widespread surface activity of 137Cs in the interval from 1000 to 2000 Bq · m-2 was mapped on mostly continuous area in the central part of map sheet and represents 68.4% of its area. The exception is only a small increase (10,225 Bq · m-2) in Banovska upland south-east from the village Zlatniky. Higher surface activities of 137Cs were registered in the north part of the map sheet. There from neighbouring map sheet (34 - Znojmo) reaches an area of increased values (3000 to 5000 Bq · m-2, max. 6550 Bq · m-2), geomorphologically falling into the western part of the White Carpathians. Relatively high surface activities of 137Cs were found in the south-east part of the map sheet in the Tribec mountains near Skycov (max. 7426 Bq.m-2), in Zitavska flood-plain south of the Zlate Moravce (max. 13962 Bq · m-2), but mainly in Vtacnik and Stiavnicke Hills, where in Nova Bana was measured the maximal surface activity 16497 Bq · m-2. Considering sizeable areal expansion of lower levels of surface activity of 137Cs, the geometric mean (1338 Bq.m-2) on this map sheet corresponds to the national average. (authors)

  17. Effect of microorganism on Greenland ice sheet surface temperature change

    Science.gov (United States)

    Shimada, R.; Takeuchi, N.; Aoki, T.

    2012-12-01

    Greenland ice sheet holds approximately 10% of the fresh water on earth. If it melts all, sea level rises about 7.2meter. It is reported that mass of Greenland ice sheet is decreasing with temperature rising of climate change. Melting of the coastal area is particularly noticeable. It is established that 4 to 23% of the sea level rising from 1993 to 2005 is caused by the melting of Greenland ice sheet. In 2010, amount of melting per year became the largest than the past. However many climate models aren't able to simulate the recent melting of snow and ice in the Arctic including Greenland. One of the possible causes is albedo reduction of snow and ice surface by light absorbing snow impurities such as black carbon and dust and by glacial microorganisms. But there are few researches for effect of glacial microorganism in wide area. So it is important to clarify the impact of glacial microorganisms in wide area. The purpose of this study is to clarify the effect of microorganism on Greenland ice sheet surface temperature change using satellite images of visible, near infrared and thermal infrared wavelength range and observation carried out in northwestern Greenland. We use MODIS Land Surface Temperature Product as ice sheet surface temperature. It estimates land surface temperature based on split window method using thermal infrared bands. MODIS data is bound to cover the whole of Greenland, and calculated the ratio of the temperature change per year. Analysis period is from December 2002 to November 2010. Results of calculating Greenland ice sheet surface temperature change using the MODIS data, our analysis shows that it is upward trend in the whole region. We find a striking upward trend in northern and western part of Greenland. The rate is 0.33±0.03 degree Celsius per a year from 47.5°W to 49°W. While in the coastal area from 49°W to 50.7°W, the rate is 0.26±0.06 degree Celsius per a year. This large upward trend area is the same area as dark region

  18. Experiments on the stability and drag of a flexible sheet under in-plane tension in uniform flow

    OpenAIRE

    Morris-Thomas, Michael T.; Steen, Sverre

    2009-01-01

    A flexible sheet in uniform parallel flow is studied in order to quantify its fluid dynamic drag and fluid-elastic stability characteristics. An experimental campaign is undertaken that involves a cantilevered sheet in air flow characterised by Reynolds numbers of order R=10^4-10^6. The properties of the sheet include: constant mass per unit area; small but finite flexural rigidity; varying aspect ratios from within the range 0.43

  19. Ohm's law for a current sheet

    Science.gov (United States)

    Lyons, L. R.; Speiser, T. W.

    1985-01-01

    The paper derives an Ohm's law for single-particle motion in a current sheet, where the magnetic field reverses in direction across the sheet. The result is considerably different from the resistive Ohm's law often used in MHD studies of the geomagnetic tail. Single-particle analysis is extended to obtain a self-consistency relation for a current sheet which agrees with previous results. The results are applicable to the concept of reconnection in that the electric field parallel to the current is obtained for a one-dimensional current sheet with constant normal magnetic field. Dissipated energy goes directly into accelerating particles within the current sheet.

  20. Imaging with parallel ray-rotation sheets

    CERN Document Server

    Hamilton, Alasdair C

    2008-01-01

    A ray-rotation sheet consists of miniaturized optical components that function - ray optically - as a homogeneous medium that rotates the local direction of transmitted light rays around the sheet normal by an arbitrary angle [A. C. Hamilton et al., arXiv:0809.2646 (2008)]. Here we show that two or more parallel ray-rotation sheets perform imaging between two planes. The image is unscaled and un-rotated. No other planes are imaged. When seen through parallel ray-rotation sheets, planes that are not imaged appear rotated, whereby the rotation angle changes with the ratio between the observer's and the object plane's distance from the sheets.

  1. Surface area estimation: pocket calculator v nomogram.

    OpenAIRE

    Briars, G L; Bailey, B J

    1994-01-01

    Three sheets of 10 surface area determinations were completed by 10 subjects using a nomogram and a formula. The formula was faster to calculate, 4.27 v 7.6 minutes for each sheet, and resulted in fewer serious errors (three v 30 errors).

  2. Producing silicon continuously

    Science.gov (United States)

    Ingle, W. M.; Rosler, R. S.; Thompson, S.

    1981-01-01

    Fluid-bed vaporization followed by chemical vapor deposition generates large, semiconductor-grade silicon particles. Method is economical, high-volume alternative to conventional batch-processing methods. Harvested chunks, extracted in cyclone separator, are about 0.5 to 1.3 centimeters in diameter. Process is not limited to polymer feedstock; it utilizes any halosilane intermediate used in silicon production.

  3. Silicon Valley Ecosystem

    Institute of Scientific and Technical Information of China (English)

    Joseph Leu

    2005-01-01

    @@ It is unlikely that any industrial region of the world has received as much scrutiny and study as Silicon Valley. Despite the recent crash of Internet and telecommunications stocks,Silicon Valley remains the world's engine of growth for numerous high-technology sectors.

  4. Cervical silicone lymphadenopathy.

    Science.gov (United States)

    Gilbert, Latoni Kaysha; Thiruchelvam, Janavikulam

    2016-07-01

    A patient presented to the department of oral and maxillofacial surgery with a rare case of cervical silicone lymphadenopathy. She had a painless ovoid mass in the left side of her neck and had had cosmetic breast augmentation 10 years before. Radiological imaging and core biopsy examination were consistent with silicone lymphadenopathy. PMID:26830068

  5. Silicon chips light up

    International Nuclear Information System (INIS)

    Researchers have demonstrated a continuous laser in silicon, which paves the way for computing at the speed of light Silicon is the racehorse of microelectronics. For the last 40 years, the number of transistors that can be crammed onto a single silicon wafer has doubled every 18 months or so, with the latest 'Itanium' chip packing in almost half a billion of them. But Moore's law, as this exponential trend is popularly known, is coming to an end due to fundamental physical limitations. These include the difficulty of keeping the chips cool and the fact that length scales are quickly approaching those of a single atom. A silicon laser could help chip makers beat these limitations by harnessing light, thus reducing the size and cost of microelectronic circuits even further,while at the same time increasing their speed. The problem is that silicon is a very inefficient light emitter, which means that silicon-based optoelectronics has remained out of reach. Since 2000 all this has changed and the race to build a silicon laser has begun in earnest. Now, Mario Paniccia and colleagues at Intel in the US and Israel have demonstrated the first continuous all-silicon laser by harnessing a phenomenon called Raman scattering (Nature 433 292 and 725). (U.K.)

  6. ALICE silicon strip module

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    This small silicon detector strip will be inserted into the inner tracking system (ITS) on the ALICE detector at CERN. This detector relies on state-of-the-art particle tracking techniques. These double-sided silicon strip modules have been designed to be as lightweight and delicate as possible as the ITS will eventually contain five square metres of these devices.

  7. Photoluminescence of Silicon Nanocrystals in Silicon Oxide

    Directory of Open Access Journals (Sweden)

    L. Pavesi

    2007-12-01

    Full Text Available Recent results on the photoluminescence properties of silicon nanocrystals embedded in silicon oxide are reviewed and discussed. The attention is focused on Si nanocrystals produced by high-temperature annealing of silicon rich oxide layers deposited by plasma-enhanced chemical vapor deposition. The influence of deposition parameters and layer thickness is analyzed in detail. The nanocrystal size can be roughly controlled by means of Si content and annealing temperature and time. Unfortunately, a technique for independently fine tuning the emission efficiency and the size is still lacking; thus, only middle size nanocrystals have high emission efficiency. Interestingly, the layer thickness affects the nucleation and growth kinetics so changing the luminescence efficiency.

  8. Study on Ka-Band Sheet Beam Traveling Wave Tube Focused by Closed PCM

    Science.gov (United States)

    Wang, Zhan-Liang; Shi, Xianbao; Gong, Yu-Bin; Wei, Yan-Yu; Duan, Zhao-Yun; Su, Xiaogang; Gong, Huarong; Feng, Jinjun; Huang, Hua

    2016-01-01

    This paper reports a Ka-band sheet beam traveling wave tube (TWT) focused by a 0.2 T closed periodic cusped magnet (PCM) system. The TWT with one section of staggered double-vane slow-wave structure (SWS) is driven by a 0.8-A sheet beam with rectangular cross-sectional area of 3.2 mm × 0.6 mm. This sheet beam TWT can produce 100 W output power, and the 3 dB band is 33-38.5 GHz. In order to improve the output power, an optimized sheet beam TWT with two sections of SWSs focused by a novel closed PCM system is proposed. The new closed PCM system is with annular magnetic blocks and can be fabricated and adjusted easily. The simulation shows that the optimized sheet beam TWT can produce 2000 W output power and the 3 dB band ranging from 33 to 40 GHz.

  9. Stability of Dirac sheet configurations

    International Nuclear Information System (INIS)

    Using cooling for SU(2) lattice configurations, purely Abelian constant magnetic-field configurations were left over after the annihilation of constituents that formed metastable Q=0 configurations. These so-called Dirac sheet configurations were found to be stable if emerging from the confined phase, close to the deconfinement phase transition, provided their Polyakov loop was sufficiently nontrivial. Here we show how this is related to the notion of marginal stability of the appropriate constant magnetic-field configurations. We find a perfect agreement between the analytic prediction for the dependence of stability on the value of the Polyakov loop (the holonomy) in a finite volume and the numerical results studied on a finite lattice in the context of the Dirac sheet configurations

  10. Steps towards silicon optoelectronics

    CERN Document Server

    Starovoytov, A

    1999-01-01

    nanostructure fabrication. Thus, this thesis makes a dual contribution to the chosen field: it summarises the present knowledge on the possibility of utilising optical properties of nanocrystalline silicon in silicon-based electronics, and it reports new results within the framework of the subject. The main conclusion is that due to its promising optoelectronic properties nanocrystalline silicon remains a prospective competitor for the cheapest and fastest microelectronics of the next century. This thesis addresses the issue of a potential future microelectronics technology, namely the possibility of utilising the optical properties of nanocrystalline silicon for optoelectronic circuits. The subject is subdivided into three chapters. Chapter 1 is an introduction. It formulates the oncoming problem for microelectronic development, explains the basics of Integrated Optoelectronics, introduces porous silicon as a new light-emitting material and gives a brief review of other competing light-emitting material syst...

  11. Silicone-containing composition

    Science.gov (United States)

    Mohamed, Mustafa

    2012-01-24

    A silicone-containing composition comprises the reaction product of a first component and an excess of an isocyanate component relative to the first component to form an isocyanated intermediary. The first component is selected from one of a polysiloxane and a silicone resin. The first component includes a carbon-bonded functional group selected from one of a hydroxyl group and an amine group. The isocyanate component is reactive with the carbon-bonded functional group of the first component. The isocyanated intermediary includes a plurality of isocyanate functional groups. The silicone-containing composition comprises the further reaction product of a second component, which is selected from the other of the polysiloxane and the silicone resin. The second component includes a plurality of carbon-bonded functional groups reactive with the isocyanate functional groups of the isocyanated intermediary for preparing the silicone-containing composition.

  12. Electromagnetic instability in a magnetic neutral sheet

    International Nuclear Information System (INIS)

    The structure of electromagnetic perturbations in a magnetic neutral sheet was analyzed within the framework of a Vlasov-Maxwellian picture. In the geomagnetic tail, there exists a stable magnetic neutral sheet of about 10 R-E (earth radius) thick. However, it has been reported that the thickness of this sheet is reduced to about 1 R-E just before the onset of substorms, and this shows the critical thickness of sheet destruction. In the laboratory experiment, a stable neutral sheet is produced by induction, and its thickness also becomes as thin as about the ion Larmor radius, which is defined far outside the sheet region, before the sudden destruction of the sheet current. Tearing instability cannot explain this abrupt destruction. Then it can be considered that the tearing instability is stabilized by some mechanisms. Consequently, it becomes important to look for another perturbation unstable in a thin sheet while stable in a thick sheet. Here, a magnetically compressional mode propagating in the direction of the unperturbed current which produced reverse field is considered. Equilibrium configuration and particle orbits, perturbations, resulted eigenfunctions and dispersion relations are described to show that the above mode becomes unstable in a thin sheet, and the critical thickness is about the ion Larmor radius just outside the sheet region. When the typical field intensity in the geomagnetic tail is taken, the time scale of this instability becomes about 800 sec. This value coincides with the observed flare time scale. (Wakatsuki, Y.)

  13. Ice Sheets and the Anthropocene

    OpenAIRE

    Wolff, Eric W.

    2014-01-01

    Ice could play a role in identifying and defining the Anthropocene. The recurrence of northern hemisphere glaciation and the stability of the Greenland Ice Sheet are both potentially vulnerable to human impact on the environment. However, only a very long hiatus in either would be unusual in the context of the Quaternary Period, requiring the definition of a geological boundary. Human influence can clearly be discerned in several ice-core measurements. These include a sharp boundary in radioa...

  14. Strontium-90 fluoride data sheet

    International Nuclear Information System (INIS)

    This report is a compilation of available data and appropriate literature references on the properties of strontium-90 fluoride and nonradioactive strontium fluoride. The objective of the document is to compile in a single source pertinent data to assist potential users in the development, licensing, and use of 90SrF2-fueled radioisotope heat sources for terrestrial power conversion and thermal applications. The report is an update of the Strontium-90 Fluoride Data Sheet (BNWL-2284) originally issued in April 1977

  15. Technology to Market Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-02-01

    This fact sheet is an overview of the Technology to Market subprogram at the U.S. Department of Energy SunShot Initiative. The SunShot Initiative’s Technology to Market subprogram builds on SunShot’s record of moving groundbreaking and early-stage technologies and business models through developmental phases to commercialization. Technology to Market targets two known funding gaps: those that occur at the prototype commercialization stage and those at the commercial scale-up stage.

  16. Silicon germanium mask for deep silicon etching

    KAUST Repository

    Serry, Mohamed

    2014-07-29

    Polycrystalline silicon germanium (SiGe) can offer excellent etch selectivity to silicon during cryogenic deep reactive ion etching in an SF.sub.6/O.sub.2 plasma. Etch selectivity of over 800:1 (Si:SiGe) may be achieved at etch temperatures from -80 degrees Celsius to -140 degrees Celsius. High aspect ratio structures with high resolution may be patterned into Si substrates using SiGe as a hard mask layer for construction of microelectromechanical systems (MEMS) devices and semiconductor devices.

  17. Amorphous silicon crystalline silicon heterojunction solar cells

    CERN Document Server

    Fahrner, Wolfgang Rainer

    2013-01-01

    Amorphous Silicon/Crystalline Silicon Solar Cells deals with some typical properties of heterojunction solar cells, such as their history, the properties and the challenges of the cells, some important measurement tools, some simulation programs and a brief survey of the state of the art, aiming to provide an initial framework in this field and serve as a ready reference for all those interested in the subject. This book helps to ""fill in the blanks"" on heterojunction solar cells. Readers will receive a comprehensive overview of the principles, structures, processing techniques and the curre

  18. Microchannel Structures of Betavoltaic Silicon Convertors

    Directory of Open Access Journals (Sweden)

    V.V. Starkov

    2015-12-01

    Full Text Available The paper presents the first results of experimental research on the microchannel structures of betavoltaic silicon converters based on the 63Ni isotope. The areas for further optimization of constructive and technological performance with high conversion efficiency were detected experimentally.

  19. Silicon Pore Optics development for ATHENA

    DEFF Research Database (Denmark)

    Collon, Maximilien J.; Vacanti, Giuseppe; Guenther, Ramses;

    2015-01-01

    meet the science requirements of large effective area (1-2 m(2) at a few keV) at a focal length of 12 m. To meet the high angular resolution (5 arc seconds) requirement the X-ray lens will also need to be very accurate. Silicon Pore Optics (SPO) technology has been invented to enable building such a...

  20. Reconnection in thin current sheets

    Science.gov (United States)

    Tenerani, Anna; Velli, Marco; Pucci, Fulvia; Rappazzo, A. F.

    2016-05-01

    It has been widely believed that reconnection is the underlying mechanism of many explosive processes observed both in nature and laboratory, but the question of reconnection speed and initial trigger have remained mysterious. How is fast magnetic energy release triggered in high Lundquist (S) and Reynolds (R) number plasmas?It has been shown that a tearing mode instability can grow on an ideal timescale, i.e., independent from the the Lundquist number, once the current sheet thickness becomes thin enough, or rather the inverse aspect ratio a/L reaches a scale a/L~S-1/3. As such, the latter provides a natural, critical threshold for current sheets that can be formed in nature before they disrupt in a few Alfvén time units. Here we discuss the transition to fast reconnection extended to simple viscous and kinetic models and we propose a possible scenario for the transition to explosive reconnection in high-Lundquist number plasmas, that we support with fully nonlinear numerical MHD simulations of a collapsing current sheet.

  1. Large and fast reversible Li-ion storages in Fe2O3-graphene sheet-on-sheet sandwich-like nanocomposites

    Science.gov (United States)

    Kan, Jin; Wang, Yong

    2013-12-01

    Fe2O3 nanosheets and nanoparticles are grown on graphene by simply varying reaction solvents in a facile solvothermal/hydrothermal preparation. Fe2O3 nanosheets are uniformly dispersed among graphene nanosheets, forming a unique sheet-on-sheet nanostructure. Due to the structure affinity between two types of two dimensional nanostructures, graphene nanosheets are separated better by Fe2O3 nanosheets compared to nanoparticles and their agglomeration is largely prevented. A large surface area of 173.9 m2 g-1 is observed for Fe2O3-graphene sheet-on-sheet composite, which is more than two times as large as that of Fe2O3-graphene particle-on-sheet composite (81.5 m2 g-1). The sheet-on-sheet composite is found to be better suitable as an anode for Li-ion battery. A high reversible capacity of 662.4 mAh g-1 can be observed after 100 cycles at 1000 mA g-1. The substantially improved cycling performance is ascribed to the unique structure affinity between Fe2O3 nanosheets and graphene nanosheets, thus offering complementary property improvement.

  2. Graphene: powder, flakes, ribbons, and sheets.

    Science.gov (United States)

    James, Dustin K; Tour, James M

    2013-10-15

    fibers and in the fabrication of large area transparent electrodes. Using solid carbon sources such as polymers, food, insects, and waste, we can grow monolayer and bilayer graphene directly on metal catalysts, and carbon-sources containing nitrogen can produce nitrogen-doped graphene. The resulting graphene can be transferred to other surfaces, such as metal grids, for potential use in transparent touch screens for applications in personal electronics and large area photovoltaic devices. Because the transfer of graphene from one surface to another can lead to defects, low yields, and higher costs, we have developed methods for growing graphene directly on the substrates of interest. We can also produce patterned graphene to make GNRs or graphane/graphene superlattices within a single sheet. These superlattices could have multiple functions for use in sensors and other devices. This Account only touches upon this burgeoning area of materials chemistry, and the field will continue to expand as researchers imagine new forms and applications of graphene. PMID:23276286

  3. Superhydrophobic silicone fiber mats fabricated by electrospinning from solution

    Science.gov (United States)

    Ludwig, Bonnie; Clark, Aneta; Snow, Steven; Hill, Randal; Schmidt, Randall; Fogg, Brad; Lo, Peter

    2007-03-01

    Fine silicone fibers of 1 -- 20 μm diameter were fabricated from solution via electrospinning. These are the first examples of fine fibers prepared from silicone homopolymers. Fiber morphology (beaded, ribbon-like, smooth) and diameter were controlled. The nanoscale surface roughness of nonwoven fiber mats created with silicone fibers produced a superhydrophobic surface that had a water contact angle of ˜160^o. The superhydrophobic surface was made reversibly hydrophilic with exposure to oxygen plasma. The combination of high surface area and superhydrophobicity suggests potential applications in the areas of water-repellent textiles, filtration, adsorption and chemical separations, wound dressings, and fuel cells.

  4. A comprehensive study of the electrically conducting water based CuO and Al2O3 nanoparticles over coupled nanofluid-sheet interface

    Science.gov (United States)

    Ahmad, R.

    2016-02-01

    Many studies on nanofluid flow over a permeable/impermeable sheet prescribe the kinematics of the sheet and disregard the sheet’s mechanics. However, the current study is one of the infrequent contributions that anticipate the mechanics of both the electrically conducting nanofluid (a homogeneous mixture of nanoparticles and base fluid) and the sheet. Two types of nanoparticles, alumina and copper, with water as a base fluid over the sheet are considered. With the help of the similarity transformations, the corresponding partial differential equations for the coupled nanofluid-sheet interface are transformed into a system of ordinary differential equations. The simulations are done by using the experimentally verified results from the previous studies for viscosity and thermal conductivity. Self-similar solutions are attained by considering both analytical and numerical techniques. Dual skin friction coefficients are attained with different copper and alumina nanoparticles over both the stretching and viscous sheets. The influence of the Eckert number, magnetic and mass suction/blowing parameters on the dimensionless velocity, temperature, skin friction and heat transfer rates over the nanofluid-sheet interface are presented graphically as well as numerically. The obtained results are of potential benefit for studying nanofluid flow over various soft surfaces such as synthetic plastics, soft silicone sheet and soft synthetic rubber sheet. These surfaces are easily deformed by thermal fluctuations.

  5. A comprehensive study of the electrically conducting water based CuO and Al2O3 nanoparticles over coupled nanofluid-sheet interface

    International Nuclear Information System (INIS)

    Many studies on nanofluid flow over a permeable/impermeable sheet prescribe the kinematics of the sheet and disregard the sheet’s mechanics. However, the current study is one of the infrequent contributions that anticipate the mechanics of both the electrically conducting nanofluid (a homogeneous mixture of nanoparticles and base fluid) and the sheet. Two types of nanoparticles, alumina and copper, with water as a base fluid over the sheet are considered. With the help of the similarity transformations, the corresponding partial differential equations for the coupled nanofluid-sheet interface are transformed into a system of ordinary differential equations. The simulations are done by using the experimentally verified results from the previous studies for viscosity and thermal conductivity. Self-similar solutions are attained by considering both analytical and numerical techniques. Dual skin friction coefficients are attained with different copper and alumina nanoparticles over both the stretching and viscous sheets. The influence of the Eckert number, magnetic and mass suction/blowing parameters on the dimensionless velocity, temperature, skin friction and heat transfer rates over the nanofluid-sheet interface are presented graphically as well as numerically. The obtained results are of potential benefit for studying nanofluid flow over various soft surfaces such as synthetic plastics, soft silicone sheet and soft synthetic rubber sheet. These surfaces are easily deformed by thermal fluctuations. (paper)

  6. Programme for Monitoring of the Greenland Ice Sheet (PROMICE)

    Science.gov (United States)

    Ahlstrom, A. P.; Andersen, M. L.; Andersen, S. B.; Boncori, J. M.; Citterio, M.; Dall, J.; Fausto, R. S.; Forsberg, R.; Kristensen, S. S.; Petersen, D.; Skourup, H.; van As, D.

    2011-12-01

    The Greenland Ice Sheet is currently experiencing a dramatic mass loss, with a contribution to sea level rise that is causing concern globally. In order to increase our understanding of the processes leading to this mass loss and to better quantify the contribution to sea level rise, the Danish government initiated the Programme for Monitoring of the Greenland Ice Sheet (PROMICE) in 2007. The aim of PROMICE is to quantify the mass loss from surface melting and iceberg calving through a combination of observation and modelling. Data on the surface climate and melting is collected from a comprehensive network of automatic weather stations (AWS) spanning all regions of the Greenland Ice Sheet margin. In-situ GPS instruments on the ice margin as well as on selected outlet glaciers provide velocity observations. The in-situ data will be merged with satellite-derived velocity maps over large parts of the Greenland Ice Sheet and repeated airborne surveys of elevation and ice thickness along the entire margin to obtain the annual ice flux towards the ocean. We present results from these comprehensive observation campaigns and demonstrate the use of our online database system for public access to near real-time AWS data. Additionally, we present an estimate of the total area covered by glaciers and ice caps surrounding the ice sheet that is not based on extrapolation from partial inventories. The area estimate is derived using topographic maps from GEUS covering the entirety of Greenland at scales of 1:100.000 or 1:250.000.

  7. Silicon dioxide obtained by Polymeric Precursor Method

    International Nuclear Information System (INIS)

    The Polymeric Precursor Method is able for obtaining several oxide material types with high surface area even obtained in particle form. Several MO2 oxide types such as titanium, silicon and zirconium ones can be obtained by this methodology. In this work, the synthesis of silicon oxide was monitored by thermal analysis, XRD and surface area analysis in order to demonstrate the influence of the several synthesis and calcining parameters. Surface area values as higher as 370m2/g and increasing in the micropore volume nm were obtained when the material was synthesized by using ethylene glycol as polymerizing agent. XRD analysis showed that the material is amorphous when calcinated at 600°C in despite of the time of calcining, but the material morphology is strongly influenced by the polymeric resin composition. Using Glycerol as polymerizing agent, the pore size increase and the surface area goes down with the increasing in decomposition time, when compared to ethylene glycol. (author)

  8. n-type emitter surface passivation in c-Si solar cells by means of antireflective amorphous silicon carbide layers

    OpenAIRE

    Ferré Tomas, Rafel; Martín García, Isidro; Ortega Villasclaras, Pablo Rafael; Vetter, Michael; Torres, I.; Alcubilla González, Ramón

    2006-01-01

    Emitter saturation current densities (JOe) of phosphorus-diffused planar c-Si solar cell emitters passivated by silicon carbide (SiCx) layers have been determined in a wide sheet resistance range (20-500 Ω/sp). Phosphorus diffusions were performed using solid planar diffusion sources without employing any drive-in step. Stacks of two SiCx layers were deposited by plasma enhanced chemical vapor deposition: first a thin silicon rich layer with excellent passivating properties and th...

  9. Reconstructing the temperature regime of the Weichselian ice sheet

    Energy Technology Data Exchange (ETDEWEB)

    Holmlund, P. [Stockholm Univ. (Sweden). Dept. of Physical Geography

    1997-04-01

    Areas in Sweden are described, where the ice could have been at the pressure melting point during the last ice age. In order to calculate probable degrees of glacial erosion, estimates on the time of ice coverage and the temperature distribution in time are combined data on erosion rates from present day glaciers. An estimate of the extent of ice cover can be made using the proxy temperature record from the Greenland ice cores and a model of the ice sheet. Adding the estimations on climate and ice sheet shape outlined in this contribution, to erosion figures we may conclude that the crucial areas for glaciation erosion are within the mountains and where the present Baltic and the Gulf of Bothnia are situated. At these sites erosion rates of some tens of meters may have occurred. In inland northern Sweden and inland southern Sweden the potential for glacial erosion seems to be small. 14 refs.

  10. Internal Controls for Accounting Areas. Alliance Action Information Sheets

    Science.gov (United States)

    Technical Assistance ALLIANCE for Parent Centers, 2006

    2006-01-01

    Internal controls are important to ensure your Parent Center's resources are well protected. Steps should be taken to ensure that finance transactions are authorized by management, executed properly and on time, and recorded appropriately. Some centers may not have staff with all of the titles used in the procedures presented in this paper.…

  11. Large-area sheet task advanced dendritic web growth development

    Science.gov (United States)

    Duncan, C. S.; Seidensticker, R. G.; McHugh, J. P.; Hopkins, R. H.; Meier, D.; Schruben, J.

    1982-09-01

    The computer code for calculating web temperature distribution was expanded to provide a graphics output in addition to numerical and punch card output. The new code was used to examine various modifications of the J419 configuration and, on the basis of the results, a new growth geometry was designed. Additionally, several mathematically defined temperature profiles were evaluated for the effects of the free boundary (growth front) on the thermal stress generation. Experimental growth runs were made with modified J419 configurations to complement the modeling work. A modified J435 configuration was evaluated.

  12. Silicon applications in photonics

    Science.gov (United States)

    Jelenski, A. M.; Gawlik, G.; Wesolowski, M.

    2005-09-01

    Silicon technology enabled the miniaturization of computers and other electronic system for information storage, transmission and transformation allowing the development of the Knowledge Based Information Society. Despite the fact that silicon roadmap indicates possibilities for further improvement, already now the speed of electrons and the bandwidth of electronic circuits are not sufficient and photons are commonly utilized for signal transmission through optical fibers and purely photonic circuits promise further improvements. However materials used for these purposes II/V semiconductor compounds, glasses make integration of optoelectronic circuits with silicon complex an expensive. Therefore research on light generation, transformation and transmission in silicon is very active and recently, due to nanotechnology some spectacular results were achieved despite the fact that mechanisms of light generation are still discussed. Three topics will be discussed. Porous silicon was actively investigated due to its relatively efficient electroluminescence enabling its use in light sources. Its index of refraction, differs considerably from the index of silicon, and this allows its utilization for Bragg mirrors, wave guides and photonic crystals. The enormous surface enables several applications on medicine and biotechnology and in particular due to the effective chemo-modulation of its refracting index the design of optical chemosensors. An effective luminescence of doped and undoped nanocrystalline silicon opened another way for the construction of silicon light sources. Optical amplification was already discovered opening perspectives for the construction of nanosilicon lasers. Luminescences was observed at red, green and blue wavelengths. The used technology of silica and ion implantation are compatible with commonly used CMOS technology. Finally the recently developed and proved idea of optically pumped silicon Raman lasers, using nonlinearity and vibrations in the

  13. Amorphous silicon for thin-film transistors

    OpenAIRE

    Schropp, Rudolf Emmanuel Isidore

    1987-01-01

    Hydrogenated amorphous silicon (a-Si:H) has considerable potential as a semiconducting material for large-area photoelectric and photovoltaic applications. Moreover, a-Si:H thin-film transistors (TFT’s) are very well suited as switching devices in addressable liquid crystal display panels and addressable image sensor arrays, due to a new technology of low-cost, Iow-temperature processing overlarge areas. ... Zie: Abstract

  14. Silicon nanowire hybrid photovoltaics

    KAUST Repository

    Garnett, Erik C.

    2010-06-01

    Silicon nanowire Schottky junction solar cells have been fabricated using n-type silicon nanowire arrays and a spin-coated conductive polymer (PEDOT). The polymer Schottky junction cells show superior surface passivation and open-circuit voltages compared to standard diffused junction cells with native oxide surfaces. External quantum efficiencies up to 88% were measured for these silicon nanowire/PEDOT solar cells further demonstrating excellent surface passivation. This process avoids high temperature processes which allows for low-cost substrates to be used. © 2010 IEEE.

  15. The extreme melt across the Greenland ice sheet in 2012

    Science.gov (United States)

    Nghiem, S. V.; Hall, D. K.; Mote, T. L.; Tedesco, M.; Albert, M. R.; Keegan, K.; Shuman, C. A.; DiGirolamo, N. E.; Neumann, G.

    2012-10-01

    The discovery of the 2012 extreme melt event across almost the entire surface of the Greenland ice sheet is presented. Data from three different satellite sensors - including the Oceansat-2 scatterometer, the Moderate-resolution Imaging Spectroradiometer, and the Special Sensor Microwave Imager/Sounder - are combined to obtain composite melt maps, representing the most complete melt conditions detectable across the ice sheet. Satellite observations reveal that melt occurred at or near the surface of the Greenland ice sheet across 98.6% of its entire extent on 12 July 2012, including the usually cold polar areas at high altitudes like Summit in the dry snow facies of the ice sheet. This melt event coincided with an anomalous ridge of warm air that became stagnant over Greenland. As seen in melt occurrences from multiple ice core records at Summit reported in the published literature, such a melt event is rare with the last significant one occurring in 1889 and the next previous one around seven centuries earlier in the Medieval Warm Period. Given its rarity, the 2012 extreme melt across Greenland provides an exceptional opportunity for new studies in broad interdisciplinary geophysical research.

  16. Role of silicon in steels on galvanized coatings

    Institute of Scientific and Technical Information of China (English)

    Chunshan CHE; Jintang LU; Gang KONG; Qiaoyu XU

    2009-01-01

    In this article, five kinds of silicon-containing steel sheets have been electrodeposited, and then immersed in a pure molten zinc bath at 450 ℃ for various periods of time. The results by scanning electron microscopy (SEM) show that the coating of the sam-ple (0.09 wt pct Si) with iron-electrodeposited pretreatment eliminates the reactive zones which are found in the coating without iron-electrodeposited pretreatment. The galvanized sample (0.28 wt pct Si) with iron-electrodeposited pretreatment exhibits a compact and coherent coating. The coating of the sample (0.37 wt pct Si) with the iron-electrodeposited pretreatment experiences a transition from a compact and coherent coating to a reactive one. The energy dispersive spectrum (EDS) results reveal that for the galvanized samples with iron-electrodeposited pretreatment, ex-cessive silicon accumulates on the surface of the substrate due to the low solubility of silicon in the F, after the iron layer is depleted by the increasing growth of the Fe-Zn intermetallics. With the movement of the substrate/F interface toward the substrate, silicon-enriched α-Fe peels off from the substrate and breaks into the particles. The particles move toward the δ layer through the Γ layer because silicon-enriched α-Fe cannot be absorbed in the Γ layer. When the particles reach the δ/Γ interface, they are dissolved in the δ layer, making the Γ layer thin or even vanish.

  17. Poly(ɛ-caprolactone) (PCL)-polymeric micelle hybrid sheets for the incorporation and release of hydrophilic proteins.

    Science.gov (United States)

    Anzai, Ryosuke; Murakami, Yoshihiko

    2015-03-01

    Sheets have several advantages over conventional gel- or particle-type drug carriers. Sheets have several notable attributes: sheets' size and shape are easily adjustable, sheets are highly accessible in surgery, and sheets have a large contact area relative to drug-targeting sites. However, it is difficult to incorporate hydrophilic proteins into hydrophobic sheets and to release the proteins over the long term in a sustained manner. In the present study, we show that "poly(ɛ-caprolactone) (PCL)-polymeric micelle hybrid sheets" can be used for the incorporation and release of hydrophilic proteins. Polymeric micelles (i.e., spaces that can incorporate hydrophilic compounds) are, in this study, uniformly dispersed in hydrophobic and biocompatible biomaterial sheet. We have clarified that the composition of block copolymer, methoxy-terminated poly(ethylene glycol)-block-poly(ɛ-caprolactone) (CH3O-PEG-b-PCL), can affect two variables: the stability of w/o emulsion and the release properties of the resulting sheets, by means of visual qualitative observations, newly developed quantitative analyses (advanced fractal analysis, advanced FD) based on deviation of the fractal dimension (FD), and release experiments. We clarified that the release behavior of BSA was affected by the composition of the block copolymers and the resulting emulsion. The results obtained in this paper show that the hydrophobic sheets in which polymeric micelles providing hydrophilic spaces were dispersed could be an effective platform for incorporating and releasing hydrophilic proteins. PMID:25723105

  18. Silicon calorimetry for the SSC[ Superconducting Supercollider

    International Nuclear Information System (INIS)

    SSC experiments will rely heavily on their calorimeters. Silicon calorimetry, which has been introduced in recent years as a useful technology, has many attractive characteristics which may make it a viable option for consideration. The many attractive properties of silicon detectors are reviewed. The relevant present day applications of large areas of silicon detectors are summarize to illustrate the emerging use. The troublesome issue of radiation damage in a high luminosity environment like the SSC is considered with a summary of much of the recent new measurements which help clarify this situation. A discussion of the electronics and a possible mechanical configuration is presented, followed by a summary of the outstanding R and D issues. 31 refs., 11 figs., 3 tabs

  19. High-resolution ice thickness and bed topography of a land-terminating section of the Greenland Ice Sheet

    DEFF Research Database (Denmark)

    Lindbäck, K.; Pettersson, R.; Doyle, S. H.;

    2014-01-01

    We present ice thickness and bed topography maps with high spatial resolution (250 to 500 m) of a and-terminating section of the Greenland Ice Sheet derived from combined ground-based and airborne radar surveys. The data have a total area of ~12000 km2 and cover the whole ablation area of the....... The covered area is one of the most studied regions of the Greenland Ice Sheet with studies of mass balance, dynamics, and supraglacial lakes, and our combined dataset can be valuable for detailed studies of ice sheet dynamics and hydrology. The compiled datasets of ground-based and airborne radar...

  20. Marine & Hydrokinetic Technologies (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2010-04-01

    This fact sheet describes the U.S. Department of Energy's Water Power Program. The program supports the development of advanced water power devices that capture energy from waves, tides, ocean currents, rivers, streams, and ocean thermal gradients. The program works to promote the development and deployment of these new technologies, known as marine and hydrokinetic technologies, to assess the potential extractable energy from rivers, estuaries, and coastal waters, and to help industry harness this renewable, emissions-free resource to generate environmentally sustainable and cost-effective electricity.

  1. Silicone azide fireproof material

    Science.gov (United States)

    1978-01-01

    Finely powdered titanium oxide was added to silicone azide as the sintering agent to produce a nonflammable material. Mixing proportions, physical properties, and chemical composition of the fireproofing material are included.

  2. Silicon microfabricated beam expander

    Energy Technology Data Exchange (ETDEWEB)

    Othman, A., E-mail: aliman@ppinang.uitm.edu.my; Ibrahim, M. N.; Hamzah, I. H.; Sulaiman, A. A. [Faculty of Electrical Engineering, Universiti Teknologi MARA Malaysia, 40450, Shah Alam, Selangor (Malaysia); Ain, M. F. [School of Electrical and Electronic Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300,Nibong Tebal, Pulau Pinang (Malaysia)

    2015-03-30

    The feasibility design and development methods of silicon microfabricated beam expander are described. Silicon bulk micromachining fabrication technology is used in producing features of the structure. A high-precision complex 3-D shape of the expander can be formed by exploiting the predictable anisotropic wet etching characteristics of single-crystal silicon in aqueous Potassium-Hydroxide (KOH) solution. The beam-expander consist of two elements, a micromachined silicon reflector chamber and micro-Fresnel zone plate. The micro-Fresnel element is patterned using lithographic methods. The reflector chamber element has a depth of 40 µm, a diameter of 15 mm and gold-coated surfaces. The impact on the depth, diameter of the chamber and absorption for improved performance are discussed.

  3. Reverse annealing of boron doped polycrystalline silicon

    International Nuclear Information System (INIS)

    Thermal activation was carried out using polycrystalline silicon (poly-Si) produced through sequential-lateral-solidification or excimer-laser-crystallization (ELC) after B+ ion shower doping. The activation efficiency of the ELC samples was found to be higher than that of the SLS ones. In this regard, grain boundaries seemed to play a critical role in terms of the activation of dopants in poly-Si at low temperatures. Reverse annealing, in which a continuous loss of charge carriers occurs, was found in this study at temperatures ranging between 400 oC and 650 oC. The samples treated by rapid thermal annealing showed a lower sheet resistance than those treated by furnace annealing. Rapid thermal annealing was found to exhibit a higher activation efficiency than furnace annealing. Reverse annealing is believed to play an important role in terms of activation efficiency

  4. Reverse annealing of boron doped polycrystalline silicon

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Beop-Jong; Hong, Won-Eui [Department of Materials Science and Engineering, Hongik University, Seoul, 121-791 (Korea, Republic of); Kim, Deok Hoi; Uemoto, Tstomu; Kim, Chi Woo [LTPS Team, AMLCD Business, Samsung Electronics, Yongin-City, Gyeonggi-Do, 449-711 (Korea, Republic of); Ro, Jae-Sang [Department of Materials Science and Engineering, Hongik University, Seoul, 121-791 (Korea, Republic of)], E-mail: jsang@wow.hongik.ac.kr

    2008-07-31

    Thermal activation was carried out using polycrystalline silicon (poly-Si) produced through sequential-lateral-solidification or excimer-laser-crystallization (ELC) after B{sup +} ion shower doping. The activation efficiency of the ELC samples was found to be higher than that of the SLS ones. In this regard, grain boundaries seemed to play a critical role in terms of the activation of dopants in poly-Si at low temperatures. Reverse annealing, in which a continuous loss of charge carriers occurs, was found in this study at temperatures ranging between 400 {sup o}C and 650 {sup o}C. The samples treated by rapid thermal annealing showed a lower sheet resistance than those treated by furnace annealing. Rapid thermal annealing was found to exhibit a higher activation efficiency than furnace annealing. Reverse annealing is believed to play an important role in terms of activation efficiency.

  5. Ice sheets and sea-level changes

    OpenAIRE

    Alley, R.; Clark, P.U.; Huybrechts, Philippe; Joughin, I.

    2005-01-01

    Future sea-level rise is an important issue related to the continuing buildup of atmospheric greenhouse-gas concentrations. The Greenland and Antarctic ice sheets, with the potential to raise sea level ~70 m if completely melted, dominate uncertainties in projected sea-level change. Freshwater fluxes from these ice sheets also may affect oceanic circulation, contributing to climate change. Observational and modeling advances have reduced many uncertainties related to ice sheet behavior, but r...

  6. Zika Virus Advice for Mountaineers: A UIAA Medcom Consensus Advice Sheet.

    Science.gov (United States)

    Hillebrandt, David; Richards, Paul; Clark, Andy; Jean, Dominique

    2016-06-01

    Hillebrandt, David, Paul Richards, Andy Clark, and Dominique Jean. Zika virus advice for mountaineers: A UIAA Medcom consensus advice sheet. High Alt Med Biol. 17:70-71, 2016.-With the current media coverage of the spread of Zika virus from Africa and Asia to Central and South America and its possible relationship with fetal abnormalities, UIAA Medcom has produced an advice sheet for mountaineers visiting risk areas. PMID:27081746

  7. Catastrophic Impact of Silicon on Silicon: Unraveling the Genesis Impact Using Sample 61881

    Science.gov (United States)

    Kuhlman, K. R.; Kim, H.; Jurewicz, A. J. G.; Gonzalez, C. P.; Allums, K. K.

    2016-01-01

    The Genesis mission collected solar wind and brought it back to Earth in order to provide precise knowledge of solar isotopic and elemental compositions. The ions in the solar wind were stopped in the collectors at depths on the order of 10 to a few hundred nanometers. This shallow implantation layer is critical for scientific analysis of the composition of the solar wind and must be preserved throughout sample handling, cleaning, processing, distribution, preparation and analysis. The current work is motivated by the need to understand the interaction of the Genesis payload with contamination during the crash in the Utah desert. Silicon contamination has been found to be notoriously difficult to remove from silicon samples despite multiple cleanings with multiple techniques. However, the question has been posed, "Does the silicon really need to be removed for large area analyses?." If the recalcitrant silicon contamination is all pure silicon from fractured collectors, only a very tiny fraction of that bulk material will contain solar wind, which could skew the analyses. This could be complicated if the silicon trapped other materials and/or gases as it impacted the surface.

  8. Nonlinear silicon photonics

    OpenAIRE

    Tsia, KK; Jalali, B.

    2010-01-01

    An intriguing optical property of silicon is that it exhibits a large third-order optical nonlinearity, with orders-ofmagnitude larger than that of silica glass in the telecommunication band. This allows efficient nonlinear optical interaction at relatively low power levels in a small footprint. Indeed, we have witnessed a stunning progress in harnessing the Raman and Kerr effects in silicon as the mechanisms for enabling chip-scale optical amplification, lasing, and wavelength conversion - f...

  9. Nanoscale Etching and Indentation of Silicon Surfaces with Carbon Nanotubes

    Science.gov (United States)

    Dzegilenko, Fedor N.; Srivastava, Deepak; Saini, Subhash

    1998-01-01

    The possibility of nanolithography of silicon and germanium surfaces with bare carbon nanotube tips of scanning probe microscopy devices is considered with large scale classical molecular dynamics (MD) simulations employing Tersoff's reactive many-body potential for heteroatomic C/Si/Ge system. Lithography plays a key role in semiconductor manufacturing, and it is expected that future molecular and quantum electronic devices will be fabricated with nanolithographic and nanodeposition techniques. Carbon nanotubes, rolled up sheets of graphene made of carbon, are excellent candidates for use in nanolithography because they are extremely strong along axial direction and yet extremely elastic along radial direction. In the simulations, the interaction of a carbon nanotube tip with silicon surfaces is explored in two regimes. In the first scenario, the nanotubes barely touch the surface, while in the second they are pushed into the surface to make "nano holes". The first - gentle scenario mimics the nanotube-surface chemical reaction induced by the vertical mechanical manipulation of the nanotube. The second -digging - scenario intends to study the indentation profiles. The following results are reported in the two cases. In the first regime, depending on the surface impact site, two major outcomes outcomes are the selective removal of either a single surface atom or a surface dimer off the silicon surface. In the second regime, the indentation of a silicon substrate by the nanotube is observed. Upon the nanotube withdrawal, several surface silicon atoms are adsorbed at the tip of the nanotube causing significant rearrangements of atoms comprising the surface layer of the silicon substrate. The results are explained in terms of relative strength of C-C, C-Si, and Si-Si bonds. The proposed method is very robust and does not require applied voltage between the nanotube tips and the surface. The implications of the reported controllable etching and hole-creating for

  10. Research on silicon microchannel arrays oxide insulation technology

    Science.gov (United States)

    Wu, Ke-xin; Duanmu, Qingduo; Wang, Guozheng; Yang, Ji-kai; Kou, Yang-qiang

    2015-03-01

    Silicon microchannel plates (Si-MCP) is widely used in the photomultiplier, night vision, X- ray intensifier and other areas. In order to meet the requirements of high voltage electron multiplier, Si-MCP need to prepare a layer of silicon dioxide in the microchannel to improve the insulating properties. There are many methods for preparing SiO2 layer, such as thermal growth, magnetron sputtering method and chemical vapor deposition etc. The thermal oxidation method is often used for preparation of insulating layer that it grows film thickness uniformity, compact structure, simple process and so on. There will be bending deformation phenomenon of silicon microchannel arrays in high temperature oxidation process. The warpage of Si-MCP has brought great for difficulties of subsequent processing. Silicon crystals has the properties of plastic deformation at high temperature, this article take full advantage of this properties by which the already bending deformation of silicon microchannel arrays can be restored to flat.

  11. Microwave synthesis of phase-pure, fine silicon carbide powder

    International Nuclear Information System (INIS)

    Fine, monophasic silicon carbide powder has been synthesized by direct solid-state reaction of its constituents namely silicon and carbon in a 2.45 GHz microwave field. Optimum parameters for the silicon carbide phase formation have been determined by varying reaction time and reaction temperature. The powders have been characterized for their particle size, surface area, phase composition (X-ray diffraction) and morphology (scanning electron microscope). Formation of phase-pure silicon carbide can be achieved at 1300 deg. C in less than 5 min of microwave exposure, resulting in sub-micron-sized particles. The free energy values for Si + C → SiC reaction were calculated for different temperatures and by comparing them with the experimental results, it was determined that phase-pure silicon carbide can be achieved at around 1135 deg. C

  12. Nanoscale semiconducting silicon as a nutritional food additive

    International Nuclear Information System (INIS)

    Very high surface area silicon powders can be realized by high energy milling or electrochemical etching techniques. Such nanoscale silicon structures, whilst biodegradable in the human gastrointestinal tract, are shown to be remarkably stable in most foodstuffs and beverages. The potential for using silicon to improve the shelf life and bioavailability of specific nutrients in functional foods is highlighted. Published drug delivery data implies that the nanoentrapment of hydrophobic nutrients will significantly improve their dissolution kinetics, through a combined effect of nanostructuring and solid state modification. Nutrients loaded to date include vitamins, fish oils, lycopene and coenzyme Q10. In addition, there is growing published evidence that optimized release of orthosilicic acid, the biodegradation product of semiconducting silicon in the gut, offers beneficial effects with regard bone health. The utility of nanoscale silicon in the nutritional field shows early promise and is worthy of much further study

  13. What Darkens the Greenland Ice Sheet?

    OpenAIRE

    Tedesco, M.; Doherty, S; Warren, S; Tranter, M.; J. Stroeve; Fettweis, Xavier; Alexander, P.

    2015-01-01

    Most of the massive ice sheet that covers roughly four fifths of Greenland melts at the surface in summer. As long as the ice sheet regains its mass in the winter, this is not catastrophic. However, if the ice sheet melted entirely, sea levels would rise by more than 7 meters, with obvious and severe consequences for human civilization. Not surprisingly, scientists are working hard to determine if and when the ice sheet will transition (or if it has already transitioned) from a stable sta...

  14. Imaging with parallel ray-rotation sheets

    OpenAIRE

    Hamilton, Alasdair C.; Courtial, Johannes

    2008-01-01

    A ray-rotation sheet consists of miniaturized optical components that function - ray optically - as a homogeneous medium that rotates the local direction of transmitted light rays around the sheet normal by an arbitrary angle [A. C. Hamilton et al., arXiv:0809.2646 (2008)]. Here we show that two or more parallel ray-rotation sheets perform imaging between two planes. The image is unscaled and un-rotated. No other planes are imaged. When seen through parallel ray-rotation sheets, planes that a...

  15. Oxygen defect processes in silicon and silicon germanium

    International Nuclear Information System (INIS)

    Silicon and silicon germanium are the archetypical elemental and alloy semiconductor materials for nanoelectronic, sensor, and photovoltaic applications. The investigation of radiation induced defects involving oxygen, carbon, and intrinsic defects is important for the improvement of devices as these defects can have a deleterious impact on the properties of silicon and silicon germanium. In the present review, we mainly focus on oxygen-related defects and the impact of isovalent doping on their properties in silicon and silicon germanium. The efficacy of the isovalent doping strategies to constrain the oxygen-related defects is discussed in view of recent infrared spectroscopy and density functional theory studies

  16. Silicon-Based Light Sources for Silicon Integrated Circuits

    Directory of Open Access Journals (Sweden)

    L. Pavesi

    2008-01-01

    Full Text Available Silicon the material per excellence for electronics is not used for sourcing light due to the lack of efficient light emitters and lasers. In this review, after having introduced the basics on lasing, I will discuss the physical reasons why silicon is not a laser material and the approaches to make it lasing. I will start with bulk silicon, then I will discuss silicon nanocrystals and Er3+ coupled silicon nanocrystals where significant advances have been done in the past and can be expected in the near future. I will conclude with an optimistic note on silicon lasing.

  17. Oxygen defect processes in silicon and silicon germanium

    Energy Technology Data Exchange (ETDEWEB)

    Chroneos, A., E-mail: alexander.chroneos@imperial.ac.uk [Faculty of Engineering and Computing, Coventry University, Priory Street, Coventry CV1 5FB (United Kingdom); Department of Materials, Imperial College London, London SW7 2BP (United Kingdom); Sgourou, E. N.; Londos, C. A. [Solid State Section, Physics Department, University of Athens, Panepistimiopolis, Zografos, 157 84 Athens (Greece); Schwingenschlögl, U. [PSE Division, KAUST, Thuwal 23955-6900 (Saudi Arabia)

    2015-06-15

    Silicon and silicon germanium are the archetypical elemental and alloy semiconductor materials for nanoelectronic, sensor, and photovoltaic applications. The investigation of radiation induced defects involving oxygen, carbon, and intrinsic defects is important for the improvement of devices as these defects can have a deleterious impact on the properties of silicon and silicon germanium. In the present review, we mainly focus on oxygen-related defects and the impact of isovalent doping on their properties in silicon and silicon germanium. The efficacy of the isovalent doping strategies to constrain the oxygen-related defects is discussed in view of recent infrared spectroscopy and density functional theory studies.

  18. Oxygen defect processes in silicon and silicon germanium

    KAUST Repository

    Chroneos, A.

    2015-06-18

    Silicon and silicon germanium are the archetypical elemental and alloy semiconductor materials for nanoelectronic, sensor, and photovoltaic applications. The investigation of radiation induced defects involving oxygen, carbon, and intrinsic defects is important for the improvement of devices as these defects can have a deleterious impact on the properties of silicon and silicon germanium. In the present review, we mainly focus on oxygen-related defects and the impact of isovalent doping on their properties in silicon and silicon germanium. The efficacy of the isovalent doping strategies to constrain the oxygen-related defects is discussed in view of recent infrared spectroscopy and density functional theory studies.

  19. Material properties of silicon and silicon carbide foams

    Science.gov (United States)

    Jacoby, Marc T.; Goodman, William A.

    2005-08-01

    Silicon and silicon carbide foams provide the lightweighting element for Schafer Corporation's silicon and silicon carbide lightweight mirror systems (SLMSTM and SiC-SLMSTM). SLMSTM and SiC-SLMSTM provide the enabling technology for manufacturing lightweight, athermal optical sub-assemblies and instruments. Silicon and silicon carbide foam samples were manufactured and tested under a Schafer-funded Internal Research and Development program in various configurations to obtain mechanical and thermal property data. The results of the mechanical tests that are reported in this paper include Young's modulus, compression strength, tensile strength, Poisson's ratio and vibrational damping. The results of the thermal tests include thermal conductivity and coefficient of thermal expansion.

  20. Finding the best swimming sheet

    Science.gov (United States)

    Ives, Tom; Morozov, Alexander

    2014-11-01

    Many microorganisms propel through fluid environments by undulating their bodies or long thin organelles (flagella). The particular waveform of the undulations can often be changed by the organism to adapt to particular environmental conditions. It has been proposed in the literature that this adaptation is driven by the desire to optimise the swimming efficiency. However, it remains an open question as to whether this is indeed the optimised quantity for microorganisms. We study propulsion in Newtonian fluids at zero inertia for a model organism, the so-called Taylor waving sheet. We develop a numerical method that allows us to calculate flow fields for sheets of arbitrary waverforms in the bulk and next to a wall. We perform optimisations of various quantities that can potentially be optimised by a swimming microorganisms (efficiency, speed, etc.) and present the optimal waveforms. We also present a simple analytical model that yields similar results. We conclude that various optimal waveforms are very similar, both in the bulk and next to a boundary, and one cannot claim that optimising the swimming efficiency is the strategy adopted by undulating microorganisms. SUPA, School of Physics & Astronomy, University of Edinburgh, UK.

  1. Magnetic properties of sheet silicates

    International Nuclear Information System (INIS)

    Susceptibility, magnetisation and Moessbauer measurements are reported for a representative selection of 2:1 layer phyllosilicates. Eight samples from the mica, vermiculite and smectite groups include examples diluted in iron which are paramagnetic at all temperatures, as well as iron-rich silicates which order magnetically below 10 K. Anisotropic susceptibility of crystals of muscovite, biotite and vermiculite is quantitatively explained with a model where the Fe2+ ions lie in sites of effective trigonal symmetry, the trigonal axis lying normal to the sheets. The ferrous ground state is an orbital singlet. Ferric iron gives an isotropic contribution to the susceptibility. Fe2+-Fe2+ exchange interactions are ferromagnetic with Gapprox. equal to2 K, whereas Fe3+-Fe3+ coupling is antiferromagnetic in the purely ferric minerals. A positive paramagnetic Curie temperature for glauconite may be attributable to Fe2+ → Fe3+ charge transfer. Magnetic order was found to set in inhomogeneously for glauconite at 1-7 K. One biotite sample showed an antiferromagnetic transition at Tsub(N) = 7 K marked by a well-defined susceptibility maximum. Its magnetic structure, consisting of ferromagnetic sheets with moments in their planes coupled antiferromagnetically by other, weak interactions, resembles that found earlier for the 1:1 mineral greenalite. (orig.)

  2. Observationally constrained projections of Antarctic ice sheet instability

    Science.gov (United States)

    Edwards, Tamsin; Ritz, Catherine; Durand, Gael; Payne, Anthony; Peyaud, Vincent; Hindmarsh, Richard

    2015-04-01

    Large parts of the Antarctic ice sheet lie on bedrock below sea level and may be vulnerable to a positive feedback known as Marine Ice Sheet Instability (MISI), a self-sustaining retreat of the grounding line triggered by oceanic or atmospheric changes. There is growing evidence MISI may be underway throughout the Amundsen Sea Embayment (ASE) of West Antarctica, induced by circulation of warm Circumpolar Deep Water. If this retreat is sustained the region could contribute up to 1-2 m to global mean sea level, and if triggered in other areas the potential contribution to sea level on centennial to millennial timescales could be two to three times greater. However, physically plausible projections of Antarctic MISI are challenging: numerical ice sheet models are too low in spatial resolution to resolve grounding line processes or else too computationally expensive to assess modelling uncertainties, and no dynamical models exist of the ocean-atmosphere-ice sheet system. Furthermore, previous numerical ice sheet model projections for Antarctica have not been calibrated with observations, which can reduce uncertainties. Here we estimate the probability of dynamic mass loss in the event of MISI under a medium climate scenario, assessing 16 modelling uncertainties and calibrating the projections with observed mass losses in the ASE from 1992-2011. We project losses of up to 30 cm sea level equivalent (SLE) by 2100 and 72 cm SLE by 2200 (95% credibility interval: CI). Our results are substantially lower than previous estimates. The ASE sustains substantial losses, 83% of the continental total by 2100 and 67% by 2200 (95% CI), but in other regions losses are limited by ice dynamical theory, observations, or a lack of projected triggers.

  3. Aircraft Sheet Metal Practices, Blueprint Reading, Sheet Metal Forming and Heat Treating; Sheet Metal Work 2: 9855.04.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    This course is designed to familiarize vocational students with construction in sheet metal layout. The document outlines goals, specific block objectives, layout practices, blueprint reading, sheet metal forming (by hand and by machine), and heat treatment of metals, and includes posttest samples. Layout techniques and air foil developing are…

  4. A silicon detector for neutrino physics

    CERN Document Server

    Kokkonen, J

    2002-01-01

    In order to demonstrate the feasibility of conducting future muon neutrino - tau neutrino oscillation searches using a high-resolution, large-area silicon microstrip detector, the Silicon TARget (STAR) detector was built. STAR was installed in the NOMAD short baseline neutrino oscillation experiment at the CERN SPS neutrino beam, where it recorded approximately 10000 neutrino interactions during the operation of the detector in the period 1997-98. It consists of five layers of silicon detectors interleaved with four layers of passive boron carbide as the target. The target mass is 45 kg, while the total silicon surface area is 1.14 square-meters and contains 32000 readout channels. The individual modules have a length of 72 cm, the longest built to date. The detection of tau particles, produced in tau neutrino charged-current interactions, would require a tracking detector with a precision of a few tens of microns in order to measure the position of the neutrino interaction vertex as well as the impact parame...

  5. Research and developments in thin-film silicon photovoltaics

    Science.gov (United States)

    Despeisse, M.; Ballif, C.; Feltrin, A.; Meillaud, F.; Fay, S.; Haug, F.-J.; Dominé, D.; Python, M.; Soderstrom, T.; Buehlmann, P.; Bugnon, G.

    2009-08-01

    The increasing demand for photovoltaic devices and the associated crystalline silicon feedstock demand scenario have led in the past years to the fast growth of the thin film silicon industry. The high potential for cost reduction and the suitability for building integration have initiated both industrial and research laboratories dynamisms for amorphous silicon and micro-crystalline silicon based photovoltaic technologies. The recent progress towards higher efficiencies thin film silicon solar cells obtained at the IMT-EPFL in Neuchatel in small-area laboratory and semi-large-area industrial Plasma Enhanced Chemical Vapor Deposition (PE-CVD) systems are reviewed. Advanced light trapping schemes are fundamental to reach high conversion efficiency and the potential of advanced Transparent Conductive Oxides (TCO) is presented, together with issues associated to the impact of the substrate morphology onto the growth of the silicon films. The recent improvements realized in amorphous-microcrystalline tandem solar cells on glass substrate are then presented, and the latest results on 1 cm2 cells are reported with up to 13.3 % initial efficiency for small-area reactors and up to 12.3 % initial for large-area industrial reactors. Finally, the different strategies to reach an improved light confinement in a thin film solar cell deposited on a flexible substrate are discussed, with the incorporation of asymmetric intermediate reflectors. Results of micromorph solar cells in the n-i-p configuration with up to 9.8 % stabilized efficiency are reported.

  6. Studies of turbulent liquid sheets for protecting IFE reactor chamber first walls

    International Nuclear Information System (INIS)

    The HYLIFE-II conceptual inertial fusion energy (IFE) reactor design uses stationary and oscillating slab jets, or liquid sheets, to create a protective pocket that allows target injection and driver beam propagation while protecting the chamber first walls from neutrons, X-rays and target debris. Thick liquid wall protection can, therefore, reduce reactor chamber size and increase chamber lifetime in commercial IFE reactors. Minimizing driver beam interference and irradiation of the final focus magnets places stringent requirements upon the surface smoothness of the stationary liquid sheets that shield the heavy-ion driver array. Experiments were carried out to determine how nozzle and flow conditioner design affect surface smoothness in turbulent liquid sheets at Reynolds numbers up to 130000. The free-surface was directly imaged using planar laser-induced fluorescence (PLIF) at downstream distances up to 25 times the sheet thickness at the nozzle exit. The data are processed to determine the probability of finding fluid at any given spatial location. The surface smoothness of sheets of water issuing from nozzles with various contractions and rectangular or nearly elliptical exits into atmospheric pressure air were quantified and compared. The free-surface characteristics of liquid sheets issuing from unblocked and partially blocked (2.5% of total area) but otherwise identical flow conditioners were compared to investigate the robustness of flow conditioning elements over long operation times. These results on nearly prototypical turbulent stationary liquid sheets address a number of technical feasibility issues for thick liquid protection in IFE reactors

  7. Airborne Laser Altimetry Mapping of the Greenland Ice Sheet: Application to Mass Balance Assessment

    Science.gov (United States)

    Abdalati, W.; Krabill, W.; Frederick, E.; Manizade, S.; Martin, C.; Sonntag, J.; Swift, R.; Thomas, R.; Wright, W.; Yungel, J.

    2000-01-01

    In 1998 and '99, the Arctic Ice Mapping (AIM) program completed resurveys of lines occupied 5 years earlier revealing elevation changes of the Greenland ice sheet and identifying areas of significant thinning, thickening and balance. In planning these surveys, consideration had to be given to the spatial constraints associated with aircraft operation, the spatial nature of ice sheet behavior, and limited resources, as well as temporal issues, such as seasonal and interannual variability in the context of measurement accuracy. This paper examines the extent to which the sampling and survey strategy is valid for drawing conclusions on the current state of balance of the Greenland ice sheet. The surveys covered the entire ice sheet with an average distance of 21.4 km between each location on the ice sheet and the nearest flight line. For most of the ice sheet, the elevation changes show relatively little spatial variability, and their magnitudes are significantly smaller than the observed elevation change signal. As a result, we conclude that the density of the sampling and the accuracy of the measurements are sufficient to draw meaningful conclusions on the state of balance of the entire ice sheet over the five-year survey period. Outlet glaciers, however, show far more spatial and temporal variability, and each of the major ones is likely to require individual surveys in order to determine its balance.

  8. Through silicon via developments for silicon photomultiplier sensors

    Science.gov (United States)

    Jackson, C.; Wall, L.; O'Neill, K.; McGarvey, B.; Herbert, D.

    2015-03-01

    Packaging can have a significant impact on the performance characteristics of Silicon Photomultipliers (SiPM) sensors as well as having an impact on reliability and yield. To provide the highest performance possible, SensL have recently developed and tested a surface mount, through silicon via (TSV) package that provides high array fill factor, high photon detection efficiency (PDE) and magnetic resonance imaging (MRI) system compatibility. The PDE of TSV packaged sensors will be shown to be the highest when compared to traditional SiPM package types. In addition the PDE in the UV and blue region will be shown to approach that of unprotected bare die. Additionally, the TSV package has minimal deadspace outside of the active area which will be shown to allow close packing when used in a sensor array. It will be shown that arrays of TSV sensors have the highest fill factor currently possible when creating arrays from singulated die. Additionally, it will be shown that TSV parts are non-magnetic and results of images taken with the TSV SiPM in a 3 Tesla magnetic resonance imaging (MRI) system will be shown to have no impact on the MRI system.

  9. Photoluminescence of porous silicon formed on ion-implanted plates of silicon

    International Nuclear Information System (INIS)

    The effect of B+, N+ ions implantation, the B+ + N+ combined implantation on the photoluminescence properties of the silicon porous layers is studied. The effect of significant luminescence areas redistribution resulting from the subsequent thermal annealing is identified. The observed effects models are proposed

  10. Fabrication and Excellent Dielectric Performance of Exfoliated Graphite Sheets

    Directory of Open Access Journals (Sweden)

    Girish M. Joshi

    2016-03-01

    Full Text Available In the present investigation, exfoliated graphite sheets were obtained from the thermo-chemical treatment of natural graphite flakes. In this process, the graphite expands almost 300-350 times of its original volume and takes the shape of worms. These worms can be pressed or rolled into any desired shape without any binder. The exfoliated graphite sheets show excellent electrical properties i.e. high dielectric constant (ε  6.374  107 and comparatively low dielectric loss (tanδ  138 across the frequency in the range 50 Hz to 30 MHz and temperature in the range 40-300 C. The products developed from exfoliated graphite can have very good sealing applications in industrial areas, especially for gaskets in the automobile industries.

  11. Steel Sheet Pile Walls in Soft Soil

    NARCIS (Netherlands)

    Kort, D.A.

    2002-01-01

    For almost a century, steel sheet pile walls are applied worldwide as earth retaining structures for excavations and quay walls. Within the framework of the development of European structural codes for Civil Engineering works, the Eurocodes, Eurocode 3 Part 5 for design of steel sheet pile walls was

  12. Fact Sheets on Pesticides in Schools.

    Science.gov (United States)

    National Coalition against the Misuse of Pesticides, Washington, DC.

    This document consists of a collection of fact sheets about the use of pesticides in schools and how to reduce it. The sheets are: (1) "Alternatives to Using Pesticides in Schools: What Is Integrated Pest Management?"; (2) "Health Effects of 48 Commonly Used Pesticides in Schools"; (3) "The Schooling of State Pesticide Laws--2002 Update: A Review…

  13. Solar cell fabricated on welded thin flexible silicon

    Directory of Open Access Journals (Sweden)

    Hessmann Maik Thomas

    2015-01-01

    Full Text Available We present a thin-film crystalline silicon solar cell with an AM1.5 efficiency of 11.5% fabricated on welded 50 μm thin silicon foils. The aperture area of the cell is 1.00 cm2. The cell has an open-circuit voltage of 570 mV, a short-circuit current density of 29.9 mA cm-2 and a fill factor of 67.6%. These are the first results ever presented for solar cells on welded silicon foils. The foils were welded together in order to create the first thin flexible monocrystalline band substrate. A flexible band substrate offers the possibility to overcome the area restriction of ingot-based monocrystalline silicon wafers and the feasibility of a roll-to-roll manufacturing. In combination with an epitaxial and layer transfer process a decrease in production costs can be achieved.

  14. The Elementary Marine Ice Sheet Model (EMISM)

    Science.gov (United States)

    Pattyn, Frank

    2015-04-01

    Ice sheet models become more and more components of global climate system modelling instead of stand-alone features to study cryospheric processes. Full coupling of ice sheet models to atmospheric and ocean models requires a standard for ice sheet models, and more precisely for marine ice sheet models, where complex feedbacks between ice and ocean, such as marine ice sheet instability, and the atmosphere, such as the elevation-mass balance feedback, operate at different time scales. Recent model intercomparisons (e.g., SeaRISE, MISMIP) have shown that basic requirements for marine ice sheet models are still lacking and that the complexity of many ice sheet models is focused on processes that are either not well captured numerically (spatial resolution issue) or are of secondary importance compared to the essential features of marine ice sheet dynamics. Here, we propose a new and fast computing ice sheet model, devoid of most complexity, but capturing the essential feedbacks when coupled to ocean or atmospheric models. Its computational efficiency guarantees to easily tests its advantages as well as limits through ensemble modelling. EMISM (Elementary Marine Ice Sheet Model) is a vertically integrated ice sheet model based on the Shallow-Ice Approximation extended a Weertman sliding law. Although vertically integrated, thermomechanical coupling is ensured through a simplified representation of ice sheet thermodynamics based on an analytical solution of the vertical temperature profile, enhanced with strain heating. The marine boundary is represented by a parameterized flux condition similar to Pollard & Deconto (2012), based on Schoof (2007). A simplified ice shelf is added to account for buttressing of ice shelves in this parameterization. The ice sheet model is solved on a finite difference grid and special care is taken to its numerical efficiency and stability. While such model has a series of (known) deficiencies with respect to short time effects, its overall

  15. Concentrating Solar Power Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-12-01

    This fact sheet is an overview of the Concentrating Solar Power (CSP) subprogram at the U.S. Department of Energy SunShot Initiative. CSP is a dispatchable, renewable energy option that uses mirrors to focus and concentrate sunlight onto a receiver, from which a heat transfer fluid carries the intense thermal energy to a power block to generate electricity. CSP systems can store solar energy to be used when the sun is not shining. It will help meet the nation’s goal of making solar energy fully cost-competitive with other energy sources by the end of the decade. Worldwide, CSP activity is rapidly scaling, with approximately 10 gigawatts (GW) in various stages of operation or development. In the United States alone, nearly 2 GW of CSP are in operation.

  16. Nanoslits in silicon chips

    International Nuclear Information System (INIS)

    Potassium hydroxide (KOH) etching of a patterned oriented silicon wafer produces V-shaped etch pits. We demonstrate that the remaining thickness of silicon at the tip of the etch pit can be reduced to ∼5 μm using an appropriately sized etch mask and optical feedback. Starting from such an etched chip, we have developed two different routes for fabricating 100 nm scale slits that penetrate through the macroscopic silicon chip (the slits are ∼850 μm wide at one face of the chip and gradually narrow to ∼100-200 nm wide at the opposite face of the chip). In the first process, the etched chips are sonicated to break the thin silicon at the tip of the etch pit and then further KOH etched to form a narrow slit. In the second process, focused ion beam milling is used to etch through the thin silicon at the tip of the etch pit. The first method has the advantage that it uses only low-resolution technology while the second method offers more control over the length and width of the slit. Our slits can be used for preparing mechanically stable, transmission electron microscopy samples compatible with electrical transport measurements or as nanostencils for depositing nanowires seamlessly connected to their contact pads.

  17. Blue-sheet instability of Schwarzschild wormholes

    International Nuclear Information System (INIS)

    The Schwarzschild wormhole geometry is found to be unstable against the gravitational effects of accumulated, blue-shifted matter and radiation, or ''blue sheets'', accreting along the past horizons. This is shown by constructing a simple model of a wormhole geometry featuring such blue sheets and manifesting their effects. In this model the blue sheets are treated as null delta-function surface layers, and we derive here general conditions for matching spacetime geometries across such null hypersurfaces of discontinuity. These junction conditions are then applied to the construction of the wormhole model. The wormhole evolution depicted in this model shows that the gravitational focussing produced by the blue-sheet mass-energy eventually encloses the blue sheets and past horizons within future horizons, leaving a black-hole geometry. These effects limit emission processes from the region of a wormhole's past singularity into the external universe, and severely restrict the possible role of wormholes in cosmological contexts. (author)

  18. The state of the Greenland Ice Sheet

    DEFF Research Database (Denmark)

    Simonsen, Sebastian Bjerregaard

    compaction on ice sheet scales. The modeling objectives are multiple and aim at estimating the contribution from the firn to the observed volume change of the GrIS and to the diffusion of stable water isotopes. The firn modeling then provides crucial information on total mass balance of the GrIS and the...... parameterized by temperature and accumulation alone, as assumed previous studies. Ice-sheet model initialization is necessary to constrain projections of future sea-level rise and assess the present state of the GrIS. In this thesis, the initialization of the GrIS is investigated through ensemble studies of...... measures, such as the total ice-sheet volume, do not capture the full aspect of the present day state of the GrIS. The ensemble of ice-sheet initializations is then used to investigate how future projections of ice sheet evolution depend on the initialization. The further projections show a surprising...

  19. Changes in the West Antarctic ice sheet

    International Nuclear Information System (INIS)

    The portion of the West Antarctic ice sheet that flows into the Ross Sea is thinning in some places and thickening in others. These changes are not caused by any current climatic change, but by the combination of a delayed response to the end of the last global glacial cycle and an internal instability. The near-future impact of the ice sheet on global sea level is largely due to processes internal to the movement of the ice sheet, and not so much to the threat of a possible greenhouse warming. Thus the near-term future of the ice sheet is already determined. However, too little of the ice sheet has been surveyed to predict its overall future behavior

  20. Movable MEMS Devices on Flexible Silicon

    KAUST Repository

    Ahmed, Sally

    2013-05-05

    Flexible electronics have gained great attention recently. Applications such as flexible displays, artificial skin and health monitoring devices are a few examples of this technology. Looking closely at the components of these devices, although MEMS actuators and sensors can play critical role to extend the application areas of flexible electronics, fabricating movable MEMS devices on flexible substrates is highly challenging. Therefore, this thesis reports a process for fabricating free standing and movable MEMS devices on flexible silicon substrates; MEMS flexure thermal actuators have been fabricated to illustrate the viability of the process. Flexure thermal actuators consist of two arms: a thin hot arm and a wide cold arm separated by a small air gap; the arms are anchored to the substrate from one end and connected to each other from the other end. The actuator design has been modified by adding etch holes in the anchors to suit the process of releasing a thin layer of silicon from the bulk silicon substrate. Selecting materials that are compatible with the release process was challenging. Moreover, difficulties were faced in the fabrication process development; for example, the structural layer of the devices was partially etched during silicon release although it was protected by aluminum oxide which is not attacked by the releasing gas . Furthermore, the thin arm of the thermal actuator was thinned during the fabrication process but optimizing the patterning and etching steps of the structural layer successfully solved this problem. Simulation was carried out to compare the performance of the original and the modified designs for the thermal actuators and to study stress and temperature distribution across a device. A fabricated thermal actuator with a 250 μm long hot arm and a 225 μm long cold arm separated by a 3 μm gap produced a deflection of 3 μm before silicon release, however, the fabrication process must be optimized to obtain fully functioning