327 research outputs found

    The Control of Pupil Conduct by the School

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    The rapid exhaustion of the finite reserves of fossil-fuels adds to the woes on all walks of the society, and especially on the policy-makers, scientists and engineers to devise means to mitigate the consequences. Reducing energy demand and grid-dependency by decentralized energy production can help improve energy security of a nation. A holistic approach to achieve these goals in the building sector could be through a shift towards fostering near zero-energy communities. This project is an initiative taken by the residents in Van Maanenblok, an urban residential block constructed in early 1930’s and situated at the heart of North-Rotterdam, to try to achieve self-sustainability in terms of energy consumption of the block through renovation. The objective of this study is to analyze the energy consumption of the block over the past three years and using the ‘Trias Energetica’ approach, investigate the extent to which self-sustainability is possible. This study also includes an overview on financial feasibility of this initiative together with identification of innovation opportunities. Passive energy reduction measures such as insulation, LED lighting-retrofits have been explored. Active renewable energy systems (RES) like solar photovoltaic (PV) systems, micro-windmills were designed and sized. Also, energy potential from Organic Fraction of Municipal Solid Waste (OFMSW) from within the block, and use ground-source heat pump to meet thermal energy has been investigated. The aforementioned technologies have been compared over certain financial parameters like net present value (NPV), payback period (PBP), and levelised cost of energy (LCOE) based on installation costs obtained from actual figures quoted by the installers and also general indicative market figures. Results of the study indicate that nearly 54% of present gas demand and 9% of electricity demand can be reduced by passive energy reduction measures alone. It would be possible to meet 42% and 54% of reduced electricity and gas demand respectively from RES. User-behaviour plays an important role in energy consumption and social factor largely determines the metamorphosis of projects with such complex setup. Renovation projects towards near zero energy buildings opens up several innovative opportunities and extended benefits to various actors, however stimulus from government is needed on financial and technical front in order to realize such ambitious initiatives

    The Control of Pupil Conduct by the School

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    Increases in the Irreversibility Field and the Upper Critical Field of Bulk MgB2 by ZrB2 Addition

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    In a study of the influence of ZrB2 additions on the irreversibility field, Birr and the upper critical field Bc2, bulk samples with 7.5 at. % ZrB2 additions were made by a powder milling and compaction technique. These samples were then heated to 700-900C for 0.5 hours. Resistive transitions were measured at 4.2 K and Birr and Bc2 values were determined. An increase in Bc2 from 20.5 T to 28.6 T and enhancement of Birr from 16 T to 24 T were observed in the ZrB2 doped sample as compared to the binary sample at 4.2 K. Critical field increases similar to those found with SiC doping were seen at 4.2 K. At higher temperatures, increases in Birr were also determined by M-H loop extrapolation and closure. Values of Birr which were enhanced with ZrB2 doping (as compared to the binary) were seen at temperatures up to 34 K, with Birr values larger than those for SiC doped samples at higher temperatures. The transition temperature, Tc, was then measured using DC susceptibility and a 2.5 K drop of the midpoint of Tc was observed. The critical current density was determined using magnetic measurements and was found to increase at all temperatures between 4.2 K and 35 K with ZrB2 doping.Comment: 15 pages, 5 figs, 1 tabl

    Magnetization and Loss Measurements of YBCO CORC and Roebel Cables for Accelerators using ±T dipole Susceptometer

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    This CORC sample Magnetization reaches about 900 kA/m (cable volume) and 2200 kA/m (strand volume) near injection This Roebel cable reaches about 2000 kA/m (cable volume) and 2400 kA/m (strand volume) near injection These values agree well with individual tape values if (i) we normalize to strand volume, Correct CORC for twisting These values can be compared to NbTi Minj = 10 kA/m b3 = 3-6 units Nb3Sn Minj = 100 kA/m b3 = 30 units Here Minj is 100 X higher than NbTi and 10 X higher than NbTi Not insurmountable, but must be considered when thinking about particle beam steering magnet qualit

    AC Loss and Contact Resistance In Copper-Stabilized Nb3Al Rutherford Cables with and without a Stainless Steel Core

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    Calorimetric measurements of AC loss and hence interstrand contact resistance (ICR), were measured on three samples of Rutherford cable wound with Cu-stabilized jelly-roll type unplated Nb3Al strand. One of the cable types was furnished with a thin core of AISI 316L stainless steel and the other two were both uncored but insulated in different ways. The cables were subjected to a room-temperature-applied uniaxial pressure of 12 MPa that was maintained during the reaction heat treatment (RHT), then vacuum impregnated with CTD 101 epoxy, and repressurized to 100 MPa during AC-loss measurement. The measurements were performed at 4.2 K in a sinusoidal field of amplitude 400 mT at frequencies of 1 to 90 mHz (no DC-bias field) that was applied both perpendicular and parallel to the face of the cable (the face-on, FO, and edge-on, EO, directions, respectively). For the cored cable the FO-measured effective ICR (FO-ICR), was 5.27 . Those for the uncored cables were less than 0.08 . As shown previously for NbTi- and Nb3Sn-based Rutherford cables, the FO-ICR can be significantly increased by the insertion of a core, although in this case it is still below the range recommended for accelerator-magnet use. Post-measurement dissection of one of the cables showed that the impregnating resin had permeated between the strands and coated the core with a thin, insulating layer excepting for some sintered points of contact. In the uncored cables the strands were coated with resin except for the points of interstrand contact. It is suggested that in the latter case this tendency for partial coating leads to a processing-sensitive FO-ICR.Comment: Four pages, with two figure

    Transport and magnetic Jc of MgB2 strands and small helical coils

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    The critical current densities of MgB2 monofilamentary strands with and without SiC additions were measured at 4.2 K. Additionally, magnetic Jc at B = 1 T was measured from 4.2 K to 40 K. Various heat treatment times and temperatures were investigated for both short samples and small helical coils. SiC additions were seen to improve high field transport Jc at 4.2 K, but improvements were not evident at 1 T at any temperature. Transport results were relatively insensitive to heat treatment times and temperatures for both short samples and coils in the 700C to 900C range.Comment: 8 text pages, 1 table, 4 fig

    Development of APC (ZrO2) Nb3Sn Multifilamentary and Ternary Conductor

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    This work was supported by the U.S. Department of Energy, Office of Science, Division of High Energy Physics, under SBIR phase I DE-SC0013849 and University Grant DE-SC0011721We have demonstrated grain refinement by a factor of 3 and a doubling of 12 T Jcin monofilaments •Internal oxidation can be used in many Nb3Sn strand types, including Tube (demonstrated) PIT (proposed), RRP/RIT (proposed) etc. •Ternary strands under development: Possible to inject Tiinto internally oxidized Nb3Sn layers •Sn contents remain high with Tiadditions, but Bc2 increase not yet seen –may need to add more Ti •Multifilamentarystrands have been demonstrated with refined grains and enhanced Jc values. •New designs which have push non-Cu fraction to above 50% and reaction fraction to above 30% are demonstrated (measurements underway) These need (1) To be optimized, and (2) To be demonstrated for a ternary alloy with the ternary alloy Bc2 •This route is very promising for future Nb3Sn developmen
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