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Sample records for 8-inch isostatic press

  1. Hot isostatic pressing of ceramics

    Honma, K.

    1985-01-01

    A mixture containing glass 70 to 95 and BN or B4C powder (0.1-10 microns) 5 to 30 vol. % is used as a secondary pressure medium in hot isostatic pressing of ceramics. Thus, Pyrex beads were mixed with 15% vol. BN powder (average diameter 2 microns), fused at 1400 deg for 2 h, cooled, crushed, and put into a graphite crucible. A Si3N4 sintered body was embedded in the powder, heated in vacuum at 1200 deg for 2 h, treated in a hot isostatic press furnace at 1700 deg and 1000 atm. for 1 h, and cooled to give a Si3N4 ceramic. It was easily separated from the crucible.

  2. Hot isostatic pressing of nickel aluminide powders

    Powder processing of boron-microalloyed Ni3Al alloys followed by consolidation using hot isostatic pressing has been investiged. The influences of time, temperature, and pressure on HIP consolidation have been evaluated and the results are presented in the form of a consolidation map. Microstructural evolution during HIPping and subsequent heat treatment has been characterized and related to the mechanical properties. It has been found that processing parameters must be carefully controlled to suppress sulfur segregation to prior particle boundaries while promoting boron segregation to grain boundaries. Alloying with chromium has been found to promote densification and improve high temperature properties. 12 refs., 10 figs., 2 tabs

  3. Hot isostatic press waste option study report

    A Settlement Agreement between the Department of Energy and the State of Idaho mandates that all high-level radioactive waste now stored at the Idaho Chemical Processing Plant be treated so that it is ready to move out of Idaho for disposal by the target date of 2035. This study investigates the immobilization of all Idaho Chemical Processing Plant calcine, including calcined sodium bearing waste, via the process known as hot isostatic press, which produces compact solid waste forms by means of high temperature and pressure (1,050 C and 20,000 psi), as the treatment method for complying with the settlement agreement. The final waste product would be contained in stainless-steel canisters, the same type used at the Savannah River Site for vitrified waste, and stored at the Idaho National Engineering and Environmental Laboratory until a national geological repository becomes available for its disposal. The waste processing period is from 2013 through 2032, and disposal at the High Level Waste repository will probably begin sometime after 2065

  4. Hot isostatic press waste option study report

    Russell, N.E.; Taylor, D.D.

    1998-02-01

    A Settlement Agreement between the Department of Energy and the State of Idaho mandates that all high-level radioactive waste now stored at the Idaho Chemical Processing Plant be treated so that it is ready to move out of Idaho for disposal by the target date of 2035. This study investigates the immobilization of all Idaho Chemical Processing Plant calcine, including calcined sodium bearing waste, via the process known as hot isostatic press, which produces compact solid waste forms by means of high temperature and pressure (1,050 C and 20,000 psi), as the treatment method for complying with the settlement agreement. The final waste product would be contained in stainless-steel canisters, the same type used at the Savannah River Site for vitrified waste, and stored at the Idaho National Engineering and Environmental Laboratory until a national geological repository becomes available for its disposal. The waste processing period is from 2013 through 2032, and disposal at the High Level Waste repository will probably begin sometime after 2065.

  5. Hot isostatic pressing of ceramic waste from spent nuclear fuel

    Argonne National Laboratory has developed a process to immobilize waste salt containing fission products, uranium, and transuranic elements as chlorides in a glass-bonded ceramic waste form. This salt was generated in the electrorefining operation used in electrometallurgical treatment of spent Experimental Breeder Reactor-II fuel. The ceramic waste process culminated with a hot isostatic pressing operation. This paper reviews the installation and operation of a hot isostatic press in a radioactive environment. Processing conditions for the hot isostatic press are presented for non-irradiated material and irradiated material. Sufficient testing was performed to demonstrate that a hot isostatic press could be used as the final step of the processing of ceramic waste for the electrometallurgical spent fuel treatment process

  6. Hot Isostatic Pressing Technology for Defence and Space Applications

    G. Appa Rao; M. Sankaranarayana; Balasubramaniam, S

    2012-01-01

    Hot isostatic pressing (HIP) technology has been established for the development of AISI-304 stainless steel and nickel base superalloy Inconel 718 integral turbine rotors, for liquid propulsion engine of Prithvi missile, and cryoengine of geostationary satellite launch vehicle (GSLV), respectively. Before making the full size rotors, the structure – property relationships in hot isostatic pressed (HIPed) 304 stainless steel and superalloy 718 were established. The HIPed steel and superalloy ...

  7. Hot isostatic pressing of nanosized WC-Co hardmetals

    A new technique based on hot isostatic pressing (HIP) has been developed to produce dense nanosized WC-Co hardmetals without the addition of grain growth inhibitors. The glass encapsulation process is the key for the effective application of isostatic pressure at temperatures well below those usually required for reaching the closed porosity state in the WC-Co system. Fully dense WC-Co samples with cobalt contents ranging from 10 to 12 wt. % have been obtained by this technique at temperatures between 1000 oC and 1200 oC with 150 MPa of applied isostatic pressure for 30 minutes. The role of isostatic pressure on the activation of densification mechanisms is discussed. (author)

  8. MICROSTRUCTURAL ANALYSIS OF HOT ISOSTATICALLY PRESSED AL-SIC

    Bronsveld, P.M.; Hosson, J.Th. De; Sargent, M.A.; Alsem, W.H.M.

    1991-01-01

    The difference between extruded and hot isostatically pressed (HIP) Al6061 both with a T6 final heat treatment and with a 30 wt.% SiC particulate reinforcement is one of densification. The higher density of the HIP material is not translated into a stronger material. The Mg2Si precipitation is favou

  9. Cermet fabrication by thermal spraying and hot isostatic pressing

    An assessment is made of the feasibility of fabricating high integrity cermets by means of thermal spraying and hot isostatic pressing. Such cermets are applicable in the form of erosion-resistant gun tube liners obviating the use of such strategic elements as Co and Cr. Al2O3-28 vol percent Ni disks and cylinders were prepared by plasma spraying and hot isostatic pressing at 1350 C and 103 MPa. Characterization consisted of immersion density measurements and microstructural analysis. Specimens machined from the disks were used for thermal and mechanical properties testing. While thermal properties were found to be comparable to those of highly developed cermet systems, moduli and strengths were lower due to residual pores, high metal content, and a coarse microstructure

  10. Hot isostatic pressing of copper canisters for nuclear waste disposal

    This paper describes the copper canisters designed by the Swedes for nuclear waste disposal. The canister is a large, plain, cylindrical can into which the spent nuclear fuel elements can be packed and sealed for final disposal. Two canister modifications are shown which have been developed, differing only in the method of packing the fuel elements into the canister. Both design approaches use a heavy-wall copper tube as the main body with forged end pieces machined to fit snugly on the tube. The favored approach today is the use of copper powder to surround the fuel elements, rather than lead. The canisters described were inserted into the chamber of a hot isostatic press machine. The result of subjecting the evacuated canister assembly to the combination of high temperature and pressure is compaction and densification of the entire mass and the conversion of the copper powder into a solid mass of copper. As a result of the hot isostatic pressing, the overall volume of the canister is reduced and the canister takes on a very moderate hourglass shape. These prototype canisters are sectioned and examined. The examination confirms that the process worked and that the result was of high quality

  11. Molybdenum and molybdenum alloys as materials for high temperature furnaces and hot isostatic presses

    Aschenbrenner, W.; Palme, R.

    1983-04-01

    Owing to their excellent high-temperature properties molybdenum and the molybdenum alloy TZM are used as materials for high-temperature furnaces and hot isostatic presses. The setup and the function of the high-temperature furnaces and hot isostatic presses and their applications are described.

  12. Deformation Behavior of Hot Isostatic Pressing FGH96 Superalloy

    LIU Yuhong; LI Fuguo; YU Hongbo

    2006-01-01

    The deformation behavior of hot isostatic pressing (HIP) FGH96 superalloy was characterized in the temperature range of 1 000-1 100 ℃ and strain rate range of 0. 001-0.1 s-1 using hot compression testing. The flow curves of HIP FGH96 superalloy during hot deformation was analyzed systematically. The results show that deformation temperature, strain rate and strain are the main influence factors on flow stress of HIP FGH96 superalloy during hot deformation. The flow stress displays a peak at a critical strain and then decreases with further increase in strain. For a given strain, the flow stress decreases with the increase of deformation temperature, and increases with the increase of strain rate. A mathematical model of these flow curves was established through regression analysis and taking the strain as a modification factor. The calculated stress values agree well with the experimental values.

  13. Effect of hot isostatic pressing on reaction-bonded silicon nitride

    Watson, G. K.; Moore, T. J.; Millard, M. L.

    1984-01-01

    Specimens of nearly theoretical density have been obtained through the isostatic hot pressing of reaction-bonded silicon nitride under 138 MPa of pressure for two hours at 1850, 1950, and 2050 C. An amorphous phase that is introduced by the hot isostatic pressing partly accounts for the fact that while room temperature flexural strength more than doubles, the 1200 C flexural strength increases significantly only after pressing at 2050 C.

  14. Summary of Calcine Disposal Development Using Hot Isostatic Pressing

    Bateman, Ken [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wahlquist, Dennis [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hart, Edward [Idaho National Lab. (INL), Idaho Falls, ID (United States); McCartin, William [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-03-01

    Battelle Energy Alliance, LLC, has demonstrated the effectiveness of the hot isostatic press (HIP) process for treatment of hazardous high-level waste known as calcine that is stored at the Idaho Nuclear Technology and Engineering Center (INTEC) at Idaho National Laboratory. HIP trials performed with simulated calcines at Idaho National Laboratory’s Materials and Fuels Complex and an Australian Nuclear Science and Technology Organization facility from 2007 to 2010 produced a dense, monolithic waste form with increased chemical durability and effective (storage) volume reductions of ~10 to ~70% compared to granular calcine forms. In December 2009, the U.S. Department of Energy signed an amended Record of Decision selecting HIP technology as the treatment method for the 4,400 m3 of granular zirconia and alumina calcine stored at INTEC. Testing showed that HIP treatment reduces the risks associated with radioactive and hazardous constituent release, post-production handling, and long-term (repository) storage of calcines and would result in estimated storage cost savings in the billions of dollars. Battelle Energy Alliance has the ability to complete pilot-scale HIP processing of INTEC calcine, which is the next necessary step in implementing HIP processing as a calcine treatment method.

  15. Process and equipment development for hot isostatic pressing treatability study

    Bateman, Ken; Wahlquist, Dennis; Malewitz, Tim

    2015-03-01

    Battelle Energy Alliance (BEA), LLC, has developed processes and equipment for a pilot-scale hot isostatic pressing (HIP) treatability study to stabilize and volume reduce radioactive calcine stored at Idaho National Laboratory (INL). In 2009, the U. S. Department of Energy signed a Record of Decision with the state of Idaho selecting HIP technology as the method to treat 5,800 yd^3 (4,400 m^3) of granular zirconia and alumina calcine produced between 1953 and 1992 as a waste byproduct of spent nuclear fuel reprocessing. Since the 1990s, a variety of radioactive and hazardous waste forms have been remotely treated using HIP within INL hot cells. To execute the remote process at INL, waste is loaded into a stainless-steel or aluminum can, which is evacuated, sealed, and placed into a HIP furnace. The HIP simultaneously heats and pressurizes the waste, reducing its volume and increasing its durability. Two 1 gal cans of calcine waste currently stored in a shielded cask were identified as candidate materials for a treatability study involving the HIP process. Equipment and materials for cask-handling and calcine transfer into INL hot cells, as well as remotely operated equipment for waste can opening, particle sizing, material blending, and HIP can loading have been designed and successfully tested. These results demonstrate BEA’s readiness for treatment of INL calcine.

  16. Consolidation of W–Ta composites: hot isostatic pressing and spark and pulse plasma sintering

    Dias, M.; Guerreiro, F.; Correia, J. Brito; Galatanu, A.; Rosinski, M.; M. A. Monge; Munoz, A.; E. Alves; Carvalho, P.A.

    2015-01-01

    Composites consisting of tantalum fiber/powder dispersed in a nanostructured W matrix have been consolidated by spark and pulse plasma sintering as well as by hot isostatic pressing. The microstructural observations revealed that the tungsten–tantalum fiber composites consolidated by hot isostatic pressing and pulse plasma sintering presented a continuous layer of Ta2O5 phase at the W/Ta interfaces, while the samples consolidated by spark plasma sintering evidenced a Ta + Ta2O5 eutectic mixtu...

  17. Hot isostatic pressing of plasma sprayed ceramic coating

    Post-spray treatment of atmospheric pressure plasma sprayed alumina, calcia and yttria-stabilised zirconia coatings was performed on a hot isostatic press (HIP) furnace. The three major variables in HIP: temperature, pressure and time, were varied during the experiments. The coatings were placed inside a steel capsule and compacted with fine yttria stabilised zirconia powder (45-80 μm). The temperature was varied between 1200-1300 deg C while pressures of 100-200 MPa were applied. Examination of the HIPed coatings was carried out using optical microscopy and scanning electron microscopy with EDAX. The porosity level in the coatings was determined by an image analyser while phase analysis was done using X-ray diffraction. The results showed that HIP can effectively reduce the porosity level in the coatings to between ∼0.01-0.1% from initial values of 2-4%. More importantly, the cracks in the coatings were 'healed' after HIP. Hardness was found to improve particularly for the zirconia coatings, from an initial value of ∼ 700 VHN to 1300 VHN. For the alumina coatings, the hardness improved to 1900 VHN from an initial value of 1100 VHN. The HIP treatment also altered the microstructure of the coatings. In the as-sprayed state, alumina consists of the typical columnar type of lamellae layers; this, however, was converted to a grain type structure after HIP. These initial results showed that HIP can effectively improve the physical properties of plasma sprayed ceramic coatings. 7 refs., 2 tabs., 3 figs

  18. Removal of glass adhered to sintered ceramics in hot isostatic pressing

    1985-01-01

    In the hot isostatic pressing of ceramic materials in molten glass using an inert gas as a pressing medium, glass adhered to the sintered ceramics is heated to convert it to a porous glass and removed. Thus, Si3N4 powder was compacted at 5000 kg/sq cm, coated with a 0.5 mm thick BN, embedded in Pyrex glass in a graphite crucible, put inside a hot isostatic press containing Argon, hot pressed at 1750 C and 100 kg/sq cm; cooled, taken out from the crucible, heated at 1100 C for 30 minutes, cooled, and then glass adhered to the sintered body was removed.

  19. Dry bag isostatic pressing for improved green strength of surrogate nuclear fuel pellets

    Dry bag isostatic pressing is proposed for mass production of nuclear fuel pellets. Dry bag isostatically pressed rods of a fuel surrogate (95% CeO2-5% HfO2) 200 mm long by 8 mm diameter were cut into pellets using a wire saw. Four different binders and CeO2 powder obtained from two different sources were investigated. The strength of the isostatically pressed pellets for all binder systems measured by diametral compression was about 50% higher than pellets produced by uniaxial dry pressing at the same pressure. It was proposed that the less uniform density of uniaxially pressed pellets accounted for the lower strength. The strength of pellets containing CeO2 powder with significantly higher moisture content was five times higher than pellets containing CeO2 powder with a low moisture content even though they were 25% less dense. Capillary pressure of the moisture was thought to supply the added binding strength.

  20. Manufacturing near dense metal parts via indirect selective laser sintering combined with isostatic pressing

    Liu, J. H.; Shi, Y. S.; Lu, Z. L.; Huang, S. H.

    2007-11-01

    To fabricate metal parts via indirect selective laser sintering (SLS), isostatic pressing technology, including hot isostatic pressing (HIP) and cold isostatic pressing (CIP), are exploited to reform SLS green parts and make them near dense. The processes of SLS/HIP and SLS/CIP/HIP technologies are investigated respectively and the densification of AISI304 stainless steel specimens is mainly discussed. It is indicated that green parts made by indirect SLS can be pressed into near dense parts with the relative densities of 67.3% and more than 80% in SLS/HIP and SLS/CIP/HIP routes, respectively, and their densities rise if much higher CIP pressure is employed. Compared with SLS/HIP, SLS/CIP/HIP technology is regarded as a better method to manufactured dense parts, and it enlarges the application domain of indirect SLS simultaneously.

  1. Densification of boron carbide at relatively low temperatures by hot pressing and hot isostatic pressing

    The poor sinterability of B4C limits its widespread application because both high temperatures and high pressures are required for a complete densification. Moreover, B4C suffers from a low strength and fracture toughness, possesses, however, a high potential because of its extreme hardness. Reaction hot pressing of B4C-WC-TiC-Si-Co mixtures resulting in B4C-TiB2-W2B5 composites of high density exhibit remarkable mechanical properties. The influence of hot isostatic pressing (HIP) on the microstructure and the mechanical properties is investigated in cooperation with participants of the COST 503 activities and related to the strengthening and toughening mechanisms. Difficulties during densification by HIP arise from the evaporation of adsorbed volatiles as well as from the strong swelling of the powder compact due to the sintering reaction. Several HIP cycle designs were tested in order to prevent the bloating of the capsule and to control internal stresses due to the misfit of the thermal expansion of the entire phases. In comparison to single phase B4C ceramics, bending strength was improved to 1030 MPa, KIc to 5.2 MPa/m, while hardness was comparable with HV1=38 GPa. Wear test were performed and related to the toughening mechanisms. (orig.) With 56 refs., 9 tabs., 64 figs

  2. Preparation of SiC-Based Composites by Cold Isostatic Press

    Harun, M. B.; Halim, M. H.; Yazid, H.; Selamat, Z.; Sattar, M. S.; Jali, M.

    2010-03-01

    The effect of polyvinyl alcohol binder on green strength of isostatic pressed silicon carbide was studied. A lab-top spray dryer was used to coat mixed powders with the binder. The resultant powders were pressed in a steel die to obtain pre-mold at the compaction pressures of 32, 63.5, 127, 190, 254 and 317 MPa. The pre-molds were pressed using a cold isostatic press at 276 MPa to produce the green compact specimens. The porosities and compression stress of the green compact specimens produced from laboratory powder were compared with compacted specimens produced with commercial powder. Density porosimetry and universal testing machine were used to determine porosity and compression stress; respectively. The morphology and fracture surface of the green compact specimens were observed under optical and electron microscopes.

  3. Propagation of nonequilibrium phonons in aluminum-oxide ceramics fabricated by cold isostatic pressing

    Propagation of slightly nonequilibrium phonons in aluminum-oxide ceramics fabricated by cold isostatic pressing has been studied. Assuming that phonon propagation in ceramic grains is ballistic, we have analyzed characteristics of the phonon scattering and drawn some conclusions about the nature of grain boundaries

  4. Effect of Surface Preparation on CLAM/CLAM Hot Isostatic Pressing diffusion bonding joints

    Surface preparation is essential for the Hot Isostatic Pressing (HIP) diffusion bonding of RAFM steels. Hot Isostatic Pressing (HIP) diffusion bonding experiments on China Low Activation Martensitic (CLAM) steel was performed to study the effect of surface preparation. A few approaches such as hand lapping, dry-milling and grinding etc., were used to prepare the faying surfaces of the HIP joints. Different sealing techniques were used as well. The HIP parameters were 150 MPa/3 h/1150 deg. C. After post HIP heat treatment (PHHT), the tensile and Charpy impact tests were carried out. The results showed that hand lapping was not suitable to prepare the faying surfaces of HIP diffusion bonding specimens although the surface roughness by hand lapping was very low.

  5. Densification of Ti-6Al-4V powder under hot isostatic pressing

    Sundaresan, R.; Raghuram, A.C.

    1984-10-01

    Consolidation of powder through hot isostatic pressing (HIP) is being developed for many complex parts. The mechanisms that lead to the complete densification have not been experimentally studied. An attempt is made to study the densification of powders in hot isostatic pressing and compare it with the available theoretical models. For this study, a mini Hipper (2273 K, 200 MPa, 75 mm diameter x 110 mm long working volume) was used. An experiment was designed to continuously monitor the change in resistivity during densification. Ti-6Al-4V powder produced through Rotating Electrodes Process (REP) was studied after having been encapsulated in glass. The process was studied in the temperature range 1050-1300 K and pressures up to 100 MPa. The results are presented and analyzed in comparison with the models. 11 references.

  6. Effect of sintering and pressing parameters on the densification of cold isostatically pressed Al and Fe powders

    In this study, iron and aluminum powders have been pressed up to 600 MPa pressure in a cold isostatic pressing unit. Pressed specimens were sintered at 600, 620, and 640 deg. C for 20 min for aluminum and 1200 deg. C for 30, 60 and 90 min durations for iron under argon atmosphere in a tube furnace. In order to observe the effects of pressing pressure and sintering temperature and duration on sintering behavior of samples after and before sintering densification values of samples have been measured. All products were examined by scanning electron microscope in order to determine the morphological change of powders in block samples. Packing densities were initially 48% and 33 % and these values have reached to 98% and 89.2% under pressures of 600 MPa for Al and Fe powders, respectively. When these pressed specimens were sintered at 600 deg. C/20 min and 1200 deg. C/30 min, the maximum values of densification for Al and Fe powders reached to 99.3% and 91.5%, respectively

  7. Microstructure and Phase Composition of Cold Isostatically Pressed and Pressureless Sintered Silicon Nitride

    Lukianova, O. A.; Krasilnikov, V. V.; Parkhomenko, A. A.; Sirota, V. V.

    2016-01-01

    The microstructure and physical properties of new Y2O3 and Al2O3 oxide-doped silicon nitride ceramics fabricated by cold isostatic pressing and free sintering were investigated. The phase composition of produced material was also studied by X-ray diffraction at room and elevated temperature. The fabricated ceramics featured a microstructure of Si5AlON7 grains with a fine-grained α-Si3N4 with a small amount of Y2SiAlON5. Described ceramics is attractive for many high-temperature structural app...

  8. Post-treatment of thermally sprayed composite materials by hot isostatic pressing

    The post-treatment of surface protective layers by hot isostatic pressing (HIP) always contains heat treatment of the whole composite material. In this way not only the quality of the coating but also the basic material can be affected. The HIP process technique depends mainly on the initial product, its type of manufacture, its gas content, its porosity and its chemical composition. Compact composite materials can be post-compressed for not too large an open pore volume and a low gas content. One must not only observe optimisation of the HIP parameters here, but also the atmosphere of the plant. (orig.)

  9. Hot isostatically pressed manufacture of high strength MERL 76 disk and seal shapes

    Eng, R. D.; Evans, D. J.

    1982-01-01

    The feasibility of using MERL 76, an advanced high strength direct hot isostatic pressed powder metallurgy superalloy, as a full scale component in a high technology, long life, commercial turbine engine were demonstrated. The component was a JT9D first stage turbine disk. The JT9D disk rim temperature capability was increased by at least 22 C and the weight of JT9D high pressure turbine rotating components was reduced by at least 35 pounds by replacement of forged Superwaspaloy components with hot isostatic pressed (HIP) MERL 76 components. The process control plan and acceptance criteria for manufacture of MERL 76 HIP consolidated components were generated. Disk components were manufactured for spin/burst rig test, experimental engine tests, and design data generation, which established lower design properties including tensile, stress-rupture, 0.2% creep and notched (Kt = 2.5) low cycle fatigue properties, Sonntag, fatigue crack propagation, and low cycle fatigue crack threshold data. Direct HIP MERL 76, when compared to conventionally forged Superwaspaloy, is demonstrated to be superior in mechanical properties, increased rim temperature capability, reduced component weight, and reduced material cost by at least 30% based on 1980 costs.

  10. Expanded Analysis of Hot Isostatic Pressed Iodine-Loaded Silver-Exchanged Mordenite

    Jubin, R. T. [ORNL; Bruffey, S. H. [ORNL; Patton, K. K. [ORNL

    2014-09-30

    Reduced silver-exchanged mordenite (Ag0Z) is being evaluated as a potential material to control the release of radioactive iodine that is released during the reprocessing of used nuclear fuel into the plant off-gas streams. The purpose of this study was to determine if hot pressing could directly convert this iodine loaded sorbent into a waste form suitable for long-term disposition. The minimal pretreatment required for production of pressed pellets makes hot pressing a technically and economically desirable process. Initial scoping studies utilized hot uniaxial pressing (HUPing) to prepare samples of non-iodine-loaded reduced silver exchanged mordenite (Ag0Z). The resulting samples were very fragile due to the low pressure (~ 28 MPa) used. It was recommended that hot isostatic pressing (HIPing), performed at higher temperatures and pressures, be investigated. HIPing was carried out in two phases, with a third and final phase currently underway. Phase I evaluated the effects of pressure and temperature conditions on the manufacture of a pressed sample. The base material was an engineered form of silver zeolite. Six samples of Ag0Z and two samples of I-Ag0Z were pressed. It was found that HIPing produced a pressed pellet of high density. Analysis of each pressed pellet by scanning electron microscopy-energy dispersive spectrophotometry (SEM-EDS) and X-ray diffraction (XRD) demonstrated that under the conditions used for pressing, the majority of the material transforms into an amorphous structure. The only crystalline phase observed in the pressed Ag0Z material was SiO2. For the samples loaded with iodine (I-Ag0Z) iodine was present as AgI clusters at low temperatures, and transformed into AgIO4 at high temperatures. Surface mapping and EDS demonstrate segregation between silver iodide phases and silicon dioxide phases. Based on the results of the Phase I study, an expanded test matrix was developed to examine the effects of multiple source materials, compositional

  11. Microstructure and Phase Composition of Cold Isostatically Pressed and Pressureless Sintered Silicon Nitride

    Lukianova, O. A.; Krasilnikov, V. V.; Parkhomenko, A. A.; Sirota, V. V.

    2016-03-01

    The microstructure and physical properties of new Y2O3 and Al2O3 oxide-doped silicon nitride ceramics fabricated by cold isostatic pressing and free sintering were investigated. The phase composition of produced material was also studied by X-ray diffraction at room and elevated temperature. The fabricated ceramics featured a microstructure of Si5AlON7 grains with a fine-grained α-Si3N4 with a small amount of Y2SiAlON5. Described ceramics is attractive for many high-temperature structural applications due to beneficial combination of fine-grained structure with improved mechanical properties and small weight loss.

  12. Development and characterization of Be/Cu joint obtained by hot isostatic pressing

    Beryllium is one of the possible candidate for Plasma Facing Components (PFC) such as divertor or first wall in the ITER project. Due to its high thermal conductivity, copper alloys are used as heat sink material. So, in one way or another, beryllium will have to be fixed onto copper alloys. In this study, the joining of beryllium onto copper is achieved by Hot Isostatic Pressing (Solid HIP). This joining technique allows an homogeneous bonding. But, as direct bonding between Be and Cu induces intermetallics which are deleterious to the joint (interlayers are needed to avoid reaction between Be and Cu. This paper gives a description and the role of different associated interlayers used as diffusion barriers between copper and beryllium for a low in-service working temperature. Moreover, a mock-up was fabricated. Shear resistance of the junction was measured from test specimens machined from the mock-up. (authors)

  13. Manufacture of die casting dies by hot isostatic pressing. CRADA final report

    Viswanathan, S.; Ren, W.; Luk, K. [Oak Ridge National Lab., TN (United States); Brucher, H.G. [Doehler-Jarvis, Toledo, OH (United States)

    1998-09-01

    The reason for this Cooperative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory (ORNL) and Doehler-Jarvis was to investigate the manufacture die-casting dies with internal water-cooling lines by hot-isostatic pressing (HIPing) of H13 tool steel powder. The use of HIPing will allow the near-net-shape manufacture of dies and the strategic placement of water-cooling lines during manufacture. The production of near-net-shape dies by HIPing involves the generation of HIPing diagrams, the design of the can that can be used for HIPing a die with complex details, strategic placement of water-cooling lines in the die, computer modeling to predict movement of the water lines during HIPing, and the development of strategies for placing water lines in the appropriate locations. The results presented include a literature review, particle analysis and characterization of H13 tool steel powder, and modeling of the HIPing process.

  14. Microstructure and Phase Composition of Cold Isostatically Pressed and Pressureless Sintered Silicon Nitride.

    Lukianova, O A; Krasilnikov, V V; Parkhomenko, A A; Sirota, V V

    2016-12-01

    The microstructure and physical properties of new Y2O3 and Al2O3 oxide-doped silicon nitride ceramics fabricated by cold isostatic pressing and free sintering were investigated. The phase composition of produced material was also studied by X-ray diffraction at room and elevated temperature. The fabricated ceramics featured a microstructure of Si5AlON7 grains with a fine-grained α-Si3N4 with a small amount of Y2SiAlON5. Described ceramics is attractive for many high-temperature structural applications due to beneficial combination of fine-grained structure with improved mechanical properties and small weight loss. PMID:26979726

  15. Thermodynamic interactions in hot isostatic pressed graded structures of dissimilar heat resistant steels

    Prader, R. [Technische Univ., Graz (Austria). Inst. fuer Werkstoffkunde und Schweisstechnik; Buchmayr, B. [Technische Univ., Graz (Austria). Inst. fuer Werkstoffkunde und Schweisstechnik; Cerjak, H. [Technische Univ., Graz (Austria). Inst. fuer Werkstoffkunde und Schweisstechnik; Fleming, A. [Babcock Energy Ltd., Renfrew (United Kingdom); Peterseim, J. [Krupp Entwicklungszentrum GmbH, Essen (Germany)

    1995-12-01

    This paper discusses a new approach for joining dissimilar metals by the adoption of a graded chemical composition joint. The welding of such a transition piece between two dissimilar materials replaced one dissimilar weld by two similar welds. The present article considers graded joints between the two ferritic materials 10 CrMo 9 10, P 91 and the austenitic type AISI 316 realised by Hot Isostatic Pressing (HIP). The chemical gradient was obtained by blending the two parent powders in a certain ratio along the transition zone. Due to local thermodynamic interactions between different powder particles microstructure and hence the mechanical properties of the graded zone are not linearly dependent on the mixing ratio of the parent powders. A model was developed to describe the diffusion and the related microstructural changes. This theoretical model was verified by microstructural investigations. (orig.)

  16. Magnetic and magneto elastic properties of cobalt ferrite ceramic compacted through cold isostatic pressing

    Indla, Srinivas; Chelvane, Arout; Das, Dibakar

    2016-05-01

    Nano crystalline CoFe2O4 powder was prepared by combustion synthesis method. As synthesized powder was calcined at an appropriate condition to remove the impurities and to promote phase formation. Phase pure CoFe2O4 powder was pressed into cylindrical rod at an applied pressure of 200 MPa using a cold isostatic pressing. Sintering of the green compact at 1350°c for 12 hrs resulted in sintered cylindrical rod with ~85% of the theoretical density. Single phase cubic spinel structure was observed in the powder x-ray diffraction pattern of the sintered pellet. Scanning electron micrographs (SEM) of the as sintered pellet revealed the microstructure to be composed of ferrite grains of average size ~4 µm. Saturation magnetization of 72 emu/g and coercivity of 355 Oe were observed for cobalt ferrite sample. The magnetostriction was measured on a circular disc (12mm diameter and 12mm length) with the strain gauge (350 Ω) mounted on the flat surface of the circular disc. Magnetostriciton of 180 ppm and strain derivative of 1 × 10-9 m/A were observed for the sintered CoFe2O4 sample.

  17. Grain-boundary cavitation and bloating of isostatically hot-pressed magnesia-partially-stabilized zirconia on air annealing

    Commercially sintered magnesia-partially-stabilized zirconia was densified to near theoretical density by isostatic hot-pressing at 200 MPa and 17000C in argon. Subsequent air annealing above 11000C resulted in bloating of the material due to grain-boundary cavitation. Mass spectrometry of crushed samples detected the evolution of CO2 and possibly CO on annealing; the hot-pressed material showed a sudden gas evolution above 14000C. Preliminary Auger and ESCA analysis identified the presence of carbon as graphite and an undefined carbide in both the sintered and the hot-pressed material

  18. Age hardening in rapidly solidified and hot isostatically pressed beryllium-aluminum-silver alloys

    Three different alloys of beryllium, aluminum and silver were processed to powder by centrifugal atomization in a helium atmosphere. Alloy compositions were, by weight, 50% Be, 47.5% Al, 2.5% Ag, 50% Be, 47% Al, 3% Ag, and 50% Be, 46% Al, 4% Ag. Due to the low solubility of both aluminum and silver in beryllium, the silver was concentrated in the aluminum phase, which appeared to separate from the beryllium in the liquid phase. A fine, continuous composite beryllium-aluminum microstructure was formed, which did not significantly change after hot isostatically pressing at 550 C for one hour at 30,000 psi argon pressure. Samples of HIP material were solution treated at 550 C for one hour, followed by a water quench. Aging temperatures were 150, 175, 200 and 225 C for times ranging from one half hour to 65 hours. Hardness measurements were made using a diamond pyramid indenter with a load of 1 kg. Results indicate that peak hardness was reached in 36--40 hours at 175 C and 12--16 hours at 200 C aging temperature, relatively independent of alloy composition

  19. Hot Isostatic Pressing (HIP) Model Developments for P/M Alloy 690N{sub 2}

    J.W. Sears; J. Xu

    2001-08-30

    Powder Metallurgy (P/M) Alloy 690N{sub 2}, the P/M derivative of Inconel 690 (IN 690), has been shown to have a higher elevated temperature yield strength and superior stress corrosion cracking (SCC) resistance than IN 690. The property improvements seen in P/M Alloy 690N{sub 2} are due to interstitial nitrogen strengthening and precipitation hardening resulting from the formation of fine titanium/chromium--carbo-nitrides. The application of P/M Alloy 690N{sub 2} has had limited use, because of the high costs involved in producing wrought products from powder. Hot Isostatic Pressing (HIP) modeling to produce near net shapes should provide a more economical route for exploiting the benefits of Alloy 690N{sub 2}. The efforts involved in developing and verifying the P/M Alloy 690N{sub 2} HIP model are disclosed. Key to the deployment of HIP modeling is the development of the method to fabricate HIP powder containers via laser powder deposition.

  20. Microstructure and mechanical properties of hot isostatically pressed cermets with TiN coatings

    ZHENG Liyun; XIONG Weihao; YAN Xianmei; LI Guo'an

    2006-01-01

    To increase the adhesion strength between the coating and the substrate, sintered Ti(C,N)-based cermets were selected and deposited with monolayer TiN using a multiarc ion-plating technique; subsequently, hot isostatic pressing (HIPing) treatment was performed at 1000℃ using nitrogen pressure up to 110 MPa. The mechanical properties of cermets after a coating process and subsequent HIPing treatment have been evaluated with respect to the hardness, the residual stress, and the coating adhesion. The results show that after the HIPing process, there was a higher increase in critical load in the TiN-coated cermets with lower surface roughness compared with those with higher surface roughness. In all cases, the residual stress was found to be compressive. The effects of substrate surface roughness and posttreatment on the adhesion strength of the coatings were thus investigated. It was also found that the HIPing posttreatment process is well suited for increasing the adhesion strength between the coating and the substrate.

  1. A study on improving mechanical properties of porous HA tissue engineering scaffolds by hot isostatic pressing

    Various interconnected porous hydroxyapatite (HA) ceramic scaffolds are universally used to induct the tissue growth for bone repair and replacement, and serve to support the adhesion, transfer, proliferation and differentiation of cells. Impregnation of polyurethane sponges with a ceramic slurry is adopted to produce highly porous HA ceramic scaffolds with a 3D interconnected structure. However, high porosity always accompanies a decrease in the strength of the HA ceramic scaffolds. Therefore, it is significant to improve the strength of the HA ceramic scaffolds with highly interconnected porosity so that they are more suitable in clinical applications. In this work, highly porous HA ceramic scaffolds are first produced by the polymer impregnation approach, and subsequently further sintered by hot isostatic pressing (HIP). The phase composition, macro- and micro-porous structure, sintering and mechanical properties of the porous HA scaffolds are investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), nanoindentation analysis and compressive test. The experimental results show that the nanohardness and compressive strength of HIP-sintered porous HA ceramics are higher than those of commonly sintered HA scaffolds. The HIP technique can effectively improve the sintering property and densification of porous HA ceramic scaffolds, so inducing an increase in the compression strength

  2. Optimisation of hot isostatic pressing bonded SS/SS joints conditions for ITER blanket shield

    In the engineering design activity of international thermonuclear experimental reactor (ITER), stainless steels are being considered as candidates materials for several module type structures. Hot isostatic pressing (HIP) technique is expected for the fabrication of these modules. Stainless steel powders are simultaneously consolidated as mono-material block or/and joined in bi-material module. This paper reviews the manufacturing stages, non-destructive examination and the developments of the HIP bonded joints of 316L SS (powder and solid) for application to the ITER shield blanket. It is well known that the powder surface oxidation negatively influences the impact toughness of raw material and joints consolidated by this way. In order to get acceptable mechanical properties of materials, a study on the effect of reducing the powder oxygen content has been launched. To evaluate susceptibility to the oxygen content of HIPed joint specimens, tensile and toughness tests have been performed. From this study, optimal conditions of HIP were fitted and the influence of oxygen was mastered to obtain good mechanical properties of the consolidated powder material as well as for HIPed junction.

  3. High temperature mechanical performance of a hot isostatically pressed silicon nitride

    Wereszczak, A.A.; Ferber, M.K.; Jenkins, M.G.; Lin, C.K.J. [and others

    1996-01-01

    Silicon nitride ceramics are an attractive material of choice for designers and manufacturers of advanced gas turbine engine components for many reasons. These materials typically have potentially high temperatures of usefulness (up to 1400{degrees}C), are chemically inert, have a relatively low specific gravity (important for inertial effects), and are good thermal conductors (i.e., resistant to thermal shock). In order for manufacturers to take advantage of these inherent properties of silicon nitride, the high-temperature mechanical performance of the material must first be characterized. The mechanical response of silicon nitride to static, dynamic, and cyclic conditions at elevated temperatures, along with reliable and representative data, is critical information that gas turbine engine designers and manufacturers require for the confident insertion of silicon nitride components into gas turbine engines. This final report describes the high-temperature mechanical characterization and analyses that were conducted on a candidate structural silicon nitride ceramic. The high-temperature strength, static fatigue (creep rupture), and dynamic and cyclic fatigue performance were characterized. The efforts put forth were part of Work Breakdown Structure Subelement 3.2.1, {open_quotes}Rotor Data Base Generation.{close_quotes} PY6 is comparable to other hot isostatically pressed (HIPed) silicon nitrides currently being considered for advanced gas turbine engine applications.

  4. Effect of reduced cobalt contents on hot isostatically pressed powder metallurgy U-700 alloys

    Harf, F. H.

    1982-01-01

    The effect of reducing the cobalt content of prealloyed powders of UDIMET 700 (U-700) alloys to 12.7, 8.6, 4.3, and 0% was examined. The powders were hot isostatically pressed into billets, which were given heat treatments appropriate for turbine disks, namely partial solutioning at temperatures below the gamma prime solvus and four step aging treatments. Chemical analyses, metallographic examinations, and X-ray diffraction measurements were performed on the materials. Minor effects on gamma prime content and on room temperature and 650 C tensile properties were observed. Creep rupture lives at 650 C reached a maximum at the 8.4% concentration, while at 760 C a maximum in life was reached at the 4.3% cobalt level. Minimum creep rates increased with decreasing cobalt content at both test temperatures. Extended exposures at 760 and 815 C resulted in decreased tensile strengths and rupture lives for all alloys. Evidence of sigma phase formation was also found.

  5. The substitution of nickel for cobalt in hot isostatically pressed powder metallurgy UDIMET 700 alloys

    Harf, F. H.

    1985-01-01

    Nickel was substituted in various proportions for cobalt in a series of five hot-isostatically-pressed powder metallurgy alloys based on the UDIMET 700 composition. These alloys were given 5-step heat treatments appropriate for use in turbine engine disks. The resultant microstructures displayed three distinct sizes of gamma-prime particles in a gamma matrix. The higher cobalt-content alloys contained larger amounts of the finest gamma-prime particles, and had the lowest gamma-gamma-prime lattice mismatch. While all alloys had approximately the same tensile properties at 25 and 650 gamma C, the rupture lives at 650 and 760 C peaked in the alloys with cobalt contents between 12.7 and 4.3 pct. Minimum creep rates increased as cobalt contents were lowered, suggesting their correlation with the gamma-prime particle size distribution and the gamma-gamma-prime mismatch. It was also found that, on overaging at temperatures higher than suitable for turbine disk use, the high cobalt-content alloys were prone to sigma phase formation.

  6. Cyclic fatigue resistance of yttria-stabilized tetragonal zirconia polycrystals with hot isostatic press processing.

    Koyama, Taku; Sato, Toru; Yoshinari, Masao

    2012-01-01

    This study investigated the influence of surface roughness and cyclic loading on fatigue resistance in Y-TZP subjected to hot isostatic pressing (HIP). Fifty Y-TZP cylinders 3.0 mm in diameter were divided into Group A (polished by centerless method; TZP-CP) or Group B (blasted and acid-etched: TZP-SB150E). Twenty five cp-titanium cylinders (Ti-SB150E) were used as a control. Static and cyclic tests were carried out according to ISO 14801. The cyclic fatigue test was performed in distilled water at 37°C. Surface morphology and roughness as well as crystal phase on the surfaces were also evaluated. Fracture force under the static test was 1,765N (TZP-CP), 1,220N (TZP-SB150E), and 850 N (yield force, Ti-SB150E). Fracture values under the cyclic test decreased to approximately 70% of those under the static tests. These results indicate that HIPed Y-TZP with a 3.0-mm diameter has sufficient durability for application to dental implants. PMID:23207222

  7. Hot isostatic pressing of silicon nitride with boron nitride, boron carbide, and carbon additions

    Mieskowski, Diane M.; Sanders, William A.

    1989-01-01

    Si3N4 test bars containing additions of BN, B4C, and C, were hot isostatically pressed in Ta cladding at 1900 and 2050 C to 98.9 percent to 99.5 percent theoretical density. Room-temperature strength data on specimens containing 2 wt pct BN and 0.5 wt pct C were comparable to data obtained for Si3N4 sintered with Y2O3, Y2O3 and Al2O3, or ZrO2. The 1370 C strengths were less than those obtained for additions of Y2O3 or ZrO2 but greater than those obtained from a combination of Y2O3 and Al2O3. SEM fractography indicated that, as with other types of Si3N4, room-temperature strength was controlled by processing flaws. The decrease in strength at 1370 C was typical of Si3N4 having an amorphous grain-boundary phase. The primary advantage of nonoxide additions appears to be in facilitating specimen removal from the Ta cladding.

  8. Hot isostatic pressing of silicon nitride with boron nitride, boron carbide, and carbon additions

    This paper reports how Si3N4 test bars containing additions of BN, B4C, and C, were hot isostatically pressed in Ta cladding at 1900 degrees and 2050 degrees C to 98.9% to 99.5% theoretical density. Room-temperature strength data on specimens containing 2 wt% BN and 0.5 wt% C were comparable to data obtained for Si3N4 sintered with Y2O3, Y2O3 and Al2O3 or ZrO2. The 1370 degrees C strengths were less than those obtained for additions of Y2O3 or ZrO2 but greater than those obtained from a combination of Y2O3 and Al2O3. Scanning electron microscope fractography indicated that, as with other types of Si3N4, room-temperature strength was controlled by processing flaws. The decrease in strength at 1370 degrees C was typical of Si3N4 having an amorphous grain-boundary phase. The primary advantage of non-oxide additions appears to be in facilitating specimen removal from the Ta cladding

  9. Experiment study on Be|Ti/Cu|CuCrZr joints by hot isostatic pressing bonding

    Performances of Be/Cu joints fabricated by hot isostatic pressing (HIP) bonding were studied by means of various test Methods, such as shearing test, scanning electron microscopy(SEM) observation, energy dispersion spectrometer(EDS) and X-ray Diffraction(XRD) analysis, when Ti (PVD-coated on Be)/Cu (PVD-coated on CuCrZr) interlayers were used. This study considered several diffusion surface treatments (such as chemical etching, polishing, etc.) for minimizing or eliminating the effects of the oxide film on beryllium to promote good diffusion bond between these materials. Experiments indicated that the joints HIPed at 580 degree C/145 MPa/2 h showed high shearing strength (up to 123 MPa) at room temperature and no defect such as cracks was observed at the bonding interface dut to the role of the etching with a dilute acid solution to remove native oxide films on beryllium surface prior to titanium coating. The strength moderately decreased when the diffusion holding time increased from 2 h to 4 h. The thin titanium diffusion barrier (∼10μm) which was coated on the beryllium surface have prevented the reaction between Be and Cu, but CuTi phase was formed at Ti/Cu interface. It is considered the phase limited the bonding strength to higher level. (authors)

  10. Joining of tungsten to ferritic/martensitic steels by hot isostatic pressing

    Tungsten (W) was joined to ferritic/martensitic steels (FMSs) by hot isostatic pressing (HIP) with interlayers consisting of Ti or Cr coatings and inserted Ti and Cu films. The effects of interlayer type and post-HIP heat treatment (PHHT) on the joining properties of W/FMS were investigated by evaluating the joining strength and analyzing the interface microstructure. The W/FMS joint specimens with the inserted Ti films showed a higher shear strength than those with Cu films, irrespective of the coating layer type. The complicated interface microstructure with many diffusion layers in the W/FMS joint led to a decrease in the joining strength. The effect of PHHT was different depending on the interlayer type employed in the HIP joining. PHHT was beneficial especially for the HIP joined W/FMS with Ti(2 μm)/Ti(50 μm) interlayers when it was properly performed to avoid a split at the interface in an edge of the HIP joined block

  11. Interface strength measurement of hot isostatic pressed tungsten coatings on F82H substrates

    Full text of publication follows: Tungsten is a primary candidate as an armor material to protect the low activation ferritic steel wall chamber for IFE power reactors due to its low erosion rate and heat resistance. Two proposed techniques to apply tungsten coatings on F82H are vapor plasma spraying (VPS) and hot isostatic pressing (HIP). In previous work (H. Kim et al., FS and T, 2007), the failure strength of the vapor plasma sprayed (VPS) tungsten coatings was investigated. Since the VPS process results in a non-negligible amount of pores in the tungsten coating, it was concluded that the mechanical reliability of the VPS tungsten coatings is a critical issue. In the current work, HIP process is adopted to deposit the tungsten coating on F82H substrates. The interface strength of the HIP tungsten/F82H samples is measured using Laser Spallation (LS) technique and the microstructure is analyzed by Scanning Electron Microscope (SEM). Finally, the failure mechanisms of the HIP versus VPS tungsten coatings are compared. (authors)

  12. The Effectiveness of Hot Isostatic Pressing for Closing Porosity in Titanium Parts Manufactured by Selective Electron Beam Melting

    Tammas-Williams, Samuel; Withers, Philip J.; Todd, Iain; Prangnell, Philip B.

    2016-05-01

    Ti-6Al-4V parts, produced by selective electron beam melting additive manufacturing, have been studied by X-ray computed tomography (XCT) to track pore closure during a standard hot isostatic pressing (HIPing) cycle. Comparison of repeated XCT scans before and after HIPing, on worst-case samples with different geometries, confirmed that all internal porosity was shrunk to below the resolution limit of the equipment used (~5 µm) following the HIPing cycle, apart from defects with surface connected ligaments.

  13. Hot isostatic pressing process to rejuvenate serviced cast nickel base superalloy IN738 turbine blades

    Wangyao, P. [Chulalongkorn Univ., Bangkok (TH). Metallurgy and Materials Science Research Institute (MMRI); Zrnik, J. [Technical Univ. of Kosice (Czech Republic). Dept. of Materials Science; Polsilapa, S. [Kasetsart Univ., Bangkok (Thailand). Dept. of Materials Engineering, Engineering Faculty; Nisaratanaporn, E. [Chulalongkorn Univ., Bangkok (Thailand). Dept. of Metallurgy Engineering, Engineering Faculty; Homkrajai, W. [Electricity Generating Authority of Thailand (EGAT), Nonthaburi (Thailand)

    2006-07-01

    Many of land base gas turbines for power plants are already long-time operating and lots of efforts were brought to evaluate the remnant life of turbine components. The aims is to assess the actual conditions of the material used for critical components are sustainable with respect to remaining life judgement. The present work provides information on land-base gas turbine first-stage turbine blade structure degradation due to long-term thermomechanical and environmental exposure. The virgin blade was of cast and heat treated nickel base superalloy IN 738 and prior examination it was exposed more than 70 000 hours at turbine inlet temperature, operating by Electricity Generating Authority of Thailand (EGAT) company. The pieces, differently localized along the blade, were cut off for microstructural analyses, which were performed using light and scanning electron microscopy. After long-term service the gamma prime coarsening, re-precipitation of finer gamma prime precipitates and grain boundary carbide precipitates dissolving were observed. The most degraded microstructure was found at top part of trailing edge and at the middle leading edge of blade where small cracks, pores and nests of voids were observed. In order to find proper condition to recover the microstructure the attempt of rejuvenation involving hot isostatic pressing (HIP) followed by standard heat treatment of IN 738 alloy was employed to pieces of the blade. The series of HIP treatments at two different temperatures and at different holds have been conducted. This process appeared to be successful in healing of micro voids and pores in interior of blade, but no restoration of surface defects was observed. Increasing the HIP temperature and extending the HIP time higher efficiency for micro voids and porosity closing were observed. (orig.)

  14. Enhancement of the electrical characteristics of metal-free phthalocyanine films using cold isostatic pressing

    Matsushima, Toshinori, E-mail: tmatusim@opera.kyushu-u.ac.jp, E-mail: adachi@cstf.kyushu-u.ac.jp; Adachi, Chihaya, E-mail: tmatusim@opera.kyushu-u.ac.jp, E-mail: adachi@cstf.kyushu-u.ac.jp [Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Japan Science and Technology Agency (JST), ERATO, Adachi Molecular Exciton Engineering Project, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Esaki, Yu [Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan)

    2014-12-15

    Spatial gaps between grains and other grains, substrates, or electrodes in organic electronic devices are one of the causes of the reduction in the electrical characteristics. In this study, we demonstrate that cold isostatic pressing (CIP) is an effective method to crush the gaps and enhance the electrical characteristics. CIP of metal-free phthalocyanine (H{sub 2}PC) films induced a decrease in the film thickness by 34%–40% because of the gap crush. The connection of smaller grains into a larger grain and planarization of the film surface were also observed in the CIP film. The crystal axes of the H{sub 2}PC crystallites were rearranged from the a-axis to the c-axis of the α-phase crystal structure in a direction perpendicular to the substrate by CIP, indicating favorable hole injection and transport in this direction because of a better overlap of π orbitals. Thermally stimulated current measurements showed that deep hole traps disappeared and the total hole-trap density decreased after CIP. These CIP-induced changes of the film thicknesses, crystal axes and the hole traps lead to a marked increase in the hole mobility of the H{sub 2}PC films from 2.0 × 10{sup −7} to 4.0 × 10{sup −4} cm{sup 2}/V s by 2000 times in the perpendicular direction. We believe that these findings are important for unveiling the underlying carrier injection and transport mechanisms of organic films and for enhancing the performance of future organic electronic devices.

  15. Preliminary Study on Hot Isostatic Pressing Diffusion Bonding for CLAM Steel

    China Low Activation Martensitic (CLAM) steel is being developed in ASIPP (Institute of Plasma Physics, Chinese Academy of Sciences) since three years ago. CLAM is selected as the major candidate structure materials for the FDS series design of fusion reactors and for China liquid metal LiPb Test Blanket Module (TBM) for ITER i.e. DFLL-TBM, which are being carried out in ASIPP. Since the hot isostatic pressing (HIP) bonding technique is one of the main candidate bonding techniques for manufacturing of the first wall of a fusion reactor, research of the HIP technique on CLAM/CLAM is greatly needed. Preliminary HIP diffusion bonding experiments on CLAM steel have been performed. A few machining approaches such as dry-milling, turnery and grounding etc. were used to prepare the sample surfaces and then they were degreased with a mixture of alcohol, ether and acetone in an ultrasonic bath. The samples were joined by HIP diffusion bonding with the compression pressure of 150 MPa and the holding time of 2 ∼ 3 hours under different temperatures between 950 deg. and 1100 deg.. Different seal techniques of the capsules were studied as well. Then appropriate post heat treatment was done. Tests on mechanical properties of the joints such as tensile strength and impact toughness have been performed. The preliminary results show that the tensile properties are roughly the same as those of the base material. The absorbed energy of the joints at present is a little low and further research is needed to increase it. Microstructure of the joints was studied by optical microscope, SEM and TEM. Compositions of the defects on the joining line were analyzed by EDS. Through analysis of the results, optimized parameters for HIP are given. (author)

  16. MONITORING STRESSES ON THE PV-4 ISOSTATIC PRESS FROM 1960 TO 1997

    ADAMSKI, R.E.; FRAZIER, J.L.; HORAK, J.A.; HOWARD, D.C.; KELLEY, D.K.

    1998-12-01

    The PV-4 isostatic press has a very large working volume (98 ft{sup 3}) that was designed for routine operations at internal pressures up to 30 ksi and is, therefore, a unique and valuable component of the U.S. DOE Y-12 manufacturing capability. More than 13,000 pressing operations have been conducted since initiation of operations in September 1960. The pressure vessel portion consists of three concentric cylinders of high-strength steel with the outer two cylinders shrink-fitted on the imermost cylinder to minimize tensile stresses on the inner surface of the vessel. The third, outermost cylinder consists of two sections; each section is one-half the length of the pressure vessel. The vessel is contained within a large frame which is made of T-1 steel. In 1982 and 1983 precision strain gauges were mounted at selected locations on the frame and the outer surface of the pressure vessel to monitor the operating stresses. Where possible, locations of the gauges mounted in 1982 and 1983 were at or near the same locations as the strain gauges mounted in 1960 to monitor stresses on the frame and vessel during preoperational testing and design verification of the press. This report presents the information obtained with these strain gauges for tests conducted in September 1960 prior to any operation of the press and for the period July 1983 to August 1997. On September 8 and 9, 1960, Sturm & Krouse used 120 strain gauges on the frame and 20 strain gauges on the outer surface of the pressure vessel to measure strains in PV-4 as a function of operating pressure from O to 33 ksi. Although the design maximum operating pressure of the press was 30 ksi, to provide a safety factor for operations at 30 ksi and to assure totally elastic behavior of the steel components of the frame and pressure vessel at pressures above the design pressure, strains were also measured at operating pressures of 32 and 33 ksi. Sturm & Krouse observed that the stresses on the frame and vessel were a

  17. Formation of stacked luminescent complex of 8-hydroxyquinoline molecules on hydroxyapatite coating by using cold isostatic pressing.

    Matsuya, Takehiko; Otsuka, Yuichi; Tagaya, Motohiro; Motozuka, Satoshi; Ohnuma, Kiyoshi; Mutoh, Yoshiharu

    2016-01-01

    Cold isostatic pressing successfully formed a chelate complex of 8-hydroxyquinoline (8 Hq) molecules on plasma-sprayed hydroxyapatite (HAp) coating by solid-state reaction. The complex emits a fluorescence peak at approximately 500 nm by UV irradiation. The red shift of the fluorescence was newly observed in the cases of highly compressed complex due to π - π stacking of aromatic ring in the molecular structure of 8 Hq. The immersed complex coating in Simulated Body Fluid (SBF) demonstrated amorphous apatite precipitation and kept its fluorescence property. PMID:26478295

  18. Development of Be/Glidcop joint obtained by hot isostatic pressing diffusion bonding for high in-service temperature

    Saint-Antonin, F.; Bucci, P.; Burlet, H.; Le Marois, G. [CEA Centre d`Etudes de Grenoble, 38 (France); Barberi, D.; Laille, A.

    1998-01-01

    This paper addresses some aspects of the beryllium-Glidcop joining by Hot Isostatic Pressing diffusion Bonding. The quality of a joint is mainly dependent on the interface microstructure. Thus, as Be/copper direct bonding is not recommended, the choice of interlayers is a critical point. The joining process parameters, i.e. temperature, pressure and time, must take into account the in-service requirements, the mechanical and metallurgical properties of each material. The Be/Glidcop joining process developed at CEA/Grenoble is presented here. (author)

  19. Warm isostatic pressing (WIP'ing) of GS44 Si3N4 FDC parts for defect removal

    Fused deposition of ceramics (FDC) is one of the developing solid freeform fabrication (SFF) techniques. The successful production of high performance ceramics by the FDC process requires that no defects exist in the green parts. However, build defects, such as missing roads, poorly bonded layers or sub-perimeter voids can be encountered in improperly built FDC parts. In this study, a method known as WIP'ing (warm isostatic pressing) was evaluated for its ability to eliminate existing defects in GS44 Si3N4 green FDC parts. Analogous to CIP'ing (cold isostatic pressing), the green FDC parts were rubber bagged and loaded into a pressure chamber filled with water soluble oil at different temperatures, ranging from 30 to 90 deg. C, at pressures of up to 35 MPa. X-Ray radiography results indicated that at temperatures above 70 deg. C, WIP'ing was effective in closing the gaps of the intentionally placed void defects in FDC parts. However, WIP'ing above 70 deg. C was not effective in healing the defects completely. The fracture strengths of FDC parts with intentional added defects, WIP'ed above 70 deg. C were substantially lower than control samples

  20. Tensile and fracture characteristics of oxide dispersion strengthened Fe─12Cr produced by hot isostatic pressing

    De Castro, Vanessa; Garces Usan, José María; Leguey, Teresa; Pareja Pareja, Ramiro

    2011-01-01

    The mechanical characteristics of a model oxide dispersion strengthened (ODS) alloy with nominal composition Fe─12 wt%Cr─0.4 wt%Y₂O₃ were investigated by means of microhardness measurements, tensile tests up to fracture in the temperature range of 298─973 K, and fracture surface analyses. A non-ODS Fe─12 wt%Cr alloy was also studied to assess the real capacity of the oxide dispersion for strengthening the alloy. The materials were produced by mechanical alloying followed by hot isostatic pres...

  1. An infrared pyroelectric detector improved by cool isostatic pressing with cup-shaped PZT thick film on silicon substrate

    Peng, Q. X.; Wu, C. G.; Luo, W. B.; Chen, C.; Cai, G. Q.; Sun, X. Y.; Qian, D. P.

    2013-11-01

    In this paper, we presented a new pyroelectric detector with back to back silicon cups and micro-bridge structure. The PZT thick film shaped in the front cup was directly deposited with designed pattern by electrophoresis deposition (EPD). Pt/Ti Metal film, which was fabricated by standard photolithography and lift-off technology, was sputtered to connect the top electrode and the bonding pad. The cold isostatic press (CIP) treatment could be applied to improve the pyroelectric properties of PZT thick film. The infrared (IR) properties the CIP-optimized detector were measured. The voltage responsivity (RV) was 4.5 × 102 V/W at 5.3 Hz, the specific detectivity (D*) was greater than 6.34 × 108 cm Hz1/2 W-1 (frequency > 110 Hz), and the thermal time constant was 51 ms, respectively.

  2. HVOF Spraying of Fe-Based MMC Coatings with In Situ Formation of Hard Particles by Hot Isostatic Pressing

    Röttger, A.; Weber, S. L.; Theisen, W.; Rajasekaran, B.; Vaßen, R.

    2012-03-01

    Thick (2-3 mm) Fe-base coatings with admixed ferrotitanium (Fe30Ti70) were applied to austenitic steel by a high-velocity oxy-fuel process (HVOF). Hot-isostatic pressing (HIP) was carried out to the decrease porosity and to increase the material strength, wear resistance, and adhesive bond strength of the deposited coating to the substrate material. SEM and XRD investigations confirmed the formation of hard titanium carbide (TiC) particles during HIP treatment as a result of strong carbon diffusion out of the metal matrix and into the Fe30Ti70 particles. The mechanical and wear properties of the densified coatings were investigated by means of shear tests, hardness measurements, and abrasive wear tests. A comparison of the coatings in the as-sprayed and the HIPed state showed a large increase in the wear resistance due to in situ TiC formation.

  3. Experimental and Theoretical Investigations of Hot Isostatically Pressed-Produced Stainless Steel/High Alloy Tool Steel Compound Materials

    Lindwall, Greta; Flyg, Jesper; Frisk, Karin; Sandberg, Odd

    2011-05-01

    Consolidation of tool steel powders and simultaneous joining to a stainless 316L steel are performed by hot isostatic pressing (HIP). Two tool steel grades are considered: a high vanadium alloyed carbon tool steel, and a high vanadium and chromium alloyed nitrogen tool steel. The boundary layer arising during diffusion bonding is in focus and, in particular, the diffusion of carbon and nitrogen over the joint. Measurements of the elemental concentration profiles and corrosion tests by the double loop-electrochemical potentiokinetic reactivation (DL-EPR) method are performed. Comparative calculations with the DICTRA software are performed and are found to be in agreement with the experimental results. It is found that the carbon tool steel grade has a more critical influence on the corrosion resistance of the stainless 316L steel in comparison to the nitrogen tool steel grade.

  4. Verification of the effect of surface preparation on Hot Isostatic Pressing diffusion bonding joints of CLAM steel

    Hot Isostatic Pressing (HIP) diffusion bonding with CLAM steel is the primary candidate fabrication technique for the first wall (FW) of DFLL-TBM. Surface state is one of the key factors for the joints quality. The effect of surface state prepared with grinder and miller on HIP diffusion bonding joints of CLAM steel was investigated. HIP diffusion bonding was performed at 140 MPa and 1373 K within 3 h. The mechanical properties of the joints were investigated with instrumented Charpy V-notch impact tests and the microstructures of the joints were analyzed with scanning electron microscopy (SEM). The results showed that the milled samples with fine surface roughness were more suitable for CLAM steel HIP diffusion bonding

  5. Effect of hot isostatic pressing nitrogen on the microstructure and properties of a Ti(C, N)-based cermet

    YAN Xianmei; XIONG Weihao; YANG Yong; ZHENG Liyun

    2006-01-01

    The high-temperature, high-pressure hot isostatic pressing technology was used for depositing hard coatings on Ti(C, N)-based cermets. The microstructure and properties of the sample were investigated using optical microscopy, scanning electron microscopy, X-ray diffraction, electron probe microanalysis, and microhardness tester. The results showed that the rich titanium and nitrogen in surface zone were induced by the heat treatment. The high nitrogen activity of the surface region was the driving force for outward transport of titanium and inward transport of tungsten in the cobalt binder. The toughness and hardness were improved and a hardness gradient was formed. It is the high-temperature, high-pressure N2that enables closure of holes, thereby alleviating defects and prolonging tool life.

  6. Dynamic recrystallization of the hot isostatically pressed P/M superalloy FGH4096 in hot working process

    Research highlights: → Three new nucleation sites were firstly found in PM materials. → As Bulk billet with 4.0 μm in grain size was obtained. → The grain size was obviously refined since repeated DRX occurenced. - Abstract: The dynamic recrystallization (DRX) of the hot isostatically pressed P/M superalloy FGH4096 in isothermal working process was characterized and investigated by using optical microscope (OM) and transmission electron microscope (TEM) techniques. The P/M superalloy was first prepared by hot isostatically pressing. The isothermal compression tests of the P/M superalloy were then conducted in a Gleeble-1500D simulator at the temperature ranging from 1080 to 1140 deg. C and the strain rate from 0.02 to 1.0 s-1. The microstructure observation of the deformed samples showed that the necklace microstructure was obtained under the strain of 0.51 or below. The necklace microstructure is an intermediate microstructure for the complete recrystallized microstructure, which could be finally generated when the strain was about 0.69. In addition, it was found that the complete recrystallized grain quantity was increased with the increase of temperature and the decrease of strain rate. The DRX nucleation sites are classified into three regions, viz., (i) previous particle boundaries (PPBs), (ii) recrystallized grain boundaries, and (iii) twin sources. As the repeated DRX took place, the grain size was eventually refined from 30.0 to 4.0 μm after the multiaxially forging and the homogeneous bulk billet with fine DRX grains was finally obtained.

  7. Dynamic recrystallization of the hot isostatically pressed P/M superalloy FGH4096 in hot working process

    Ning Yongquan, E-mail: ningke521@163.com [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China) and Department of Mechanical Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Yao Zekun [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China); Fu, M.W. [Department of Mechanical Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Guo Hongzhen [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China)

    2010-10-15

    Research highlights: {yields} Three new nucleation sites were firstly found in PM materials. {yields} As Bulk billet with 4.0 {mu}m in grain size was obtained. {yields} The grain size was obviously refined since repeated DRX occurenced. - Abstract: The dynamic recrystallization (DRX) of the hot isostatically pressed P/M superalloy FGH4096 in isothermal working process was characterized and investigated by using optical microscope (OM) and transmission electron microscope (TEM) techniques. The P/M superalloy was first prepared by hot isostatically pressing. The isothermal compression tests of the P/M superalloy were then conducted in a Gleeble-1500D simulator at the temperature ranging from 1080 to 1140 deg. C and the strain rate from 0.02 to 1.0 s{sup -1}. The microstructure observation of the deformed samples showed that the necklace microstructure was obtained under the strain of 0.51 or below. The necklace microstructure is an intermediate microstructure for the complete recrystallized microstructure, which could be finally generated when the strain was about 0.69. In addition, it was found that the complete recrystallized grain quantity was increased with the increase of temperature and the decrease of strain rate. The DRX nucleation sites are classified into three regions, viz., (i) previous particle boundaries (PPBs), (ii) recrystallized grain boundaries, and (iii) twin sources. As the repeated DRX took place, the grain size was eventually refined from 30.0 to 4.0 {mu}m after the multiaxially forging and the homogeneous bulk billet with fine DRX grains was finally obtained.

  8. Hot isostatic pressing of silicon nitride Sisub3n4 containing zircon, or zirconia and silica

    Somiya, S.; Yoshimura, M.; Suzuki, T.; Nishimura, H.

    1980-01-01

    A hydrothermal synthesis apparatus with a 10 KB cylinder was used to obtain a sintered body of silicon nitride. The sintering auxiliary agents used were zircon (ZrSiO4) and a mixture of zirconia (ZrO2) and silica (SiO2). Experiments were conducted with the amounts of ZrSi04 or ArO2 and SiO2 varying over a wide range and the results compared to discover the quantity of additive which produced sintering in silicon nitride by the hot pressing method.

  9. Interior graphitization of furan resin-derived carbon by hot isostatic pressing

    This paper reports the investigation of morphological, textural and structural changes for furan resin-derived glass-like carbons, and the formation of spherical graphite in the carbon by hot isotropic pressing (HIP) at a temperature 2500 deg. C and under pressure 200 MPa even though the changed area took place at interior parts. We characterized the changed area by using Raman spectroscopy and XRD. It was found that the interior changes into graphite after HIP. From the scanning electron microscopy (SEM) images the interior part consisted of spheres, whose dimensions were about 20-150 μm. This graphitization is far from the previously reported ones on hard carbons even though the changed area was limited to interior

  10. Mechanical properties of hot isostatic pressed type 316LN steel after irradiation to 2.5 dpa

    Hot isostatic pressing (HIP) of powder is considered as a tentative manufacturing method for primary wall components of ITER. The mechanical properties of unirradiated specimens and specimens irradiated to a dose of 0.7 dpa at 290 degree sign C from HIPed powder and from wrought, reference, type 316 LN ITER grade steel have been reported earlier. Complementary tensile, low cycle fatigue and fracture toughness tests of the materials were performed after neutron irradiation to a dose of 2.5 dpa at 290 degree sign C. The results of these tests compared to those reported previously indicate that at the lower dose the HIPed steel shows more irradiation hardening and less elongation compared to the wrought material but after 2.5 dpa the properties are almost identical again. No significant difference in fatigue endurance (at a single strain range of 0.8%) was observed at a dose of 0.7 dpa. After 2.5 dpa the HIPed steel has a shorter average life, but the variation in the results was less compared to the wrought reference steel. The wrought steel behaved noticeably tougher than the HIPed after 0.7 and 2.5 dpa (JQ∼3xJQHIP). The two steels fractured in a ductile mode. Valid J1c data could not be obtained owing to specimen size limitations

  11. Thermal Shock and Ablation Behavior of Tungsten Nozzle Produced by Plasma Spray Forming and Hot Isostatic Pressing

    Wang, Y. M.; Xiong, X.; Zhao, Z. W.; Xie, L.; Min, X. B.; Yan, J. H.; Xia, G. M.; Zheng, F.

    2015-08-01

    Tungsten nozzle was produced by plasma spray forming (PSF, relative density of 86 ± 2%) followed by hot isostatic pressing (HIPing, 97 ± 2%) at 2000 °C and 180 MPa for 180 min. Scanning electron microscope, x-ray diffractometer, Archimedes method, Vickers hardness, and tensile tests have been employed to study microstructure, phase composition, density, micro-hardness, and mechanical properties of the parts. Resistance of thermal shock and ablation behavior of W nozzle were investigated by hot-firing test on solid rocket motor (SRM). Comparing with PSF nozzle, less damage was observed for HIPed sample after SRM test. Linear ablation rate of nozzle made by PSF was (0.120 ± 0.048) mm/s, while that after HIPing reduced to (0.0075 ± 0.0025) mm/s. Three types of ablation mechanisms including mechanical erosion, thermophysical erosion, and thermochemical ablation took place during hot-firing test. The order of degree of ablation was nozzle throat > convergence > dilation inside W nozzle.

  12. Microstructure and properties of diffusion bonded Ti-6Al-4V parts using brazing-assisted hot isostatic pressing

    Highlights: → A low cost method of diffusion bonding has been developed for complex-shaped components of Ti6Al4V. → Vacuum brazing has been used to seal the periphery to allow encapsulation-free HIPping. → The tensile properties of the bonds are comparable with those of the bulk material, but the fatigue life was slightly reduced. - Abstract: Ti-6Al-4V couples have been diffusion bonded by hot isostatic pressing (HIPping) after vacuum brazing was used to seal the periphery of the bonding samples so that no encapsulation was required during HIPping. Analytical scanning electron microscopy was used to assess the microstructure of the HIPped interface and tensile and fatigue properties of bonded samples were compared with those of the bulk starting material. The tensile properties of the bonds were shown to be comparable with those of the bulk material, but the fatigue life was slightly downgraded. The fatigue fractures were initiated by inclusions on the bonding interface, caused by contamination before bonding, but the fatigue cracks did not propagate along the bonding interface indicating a strong bond. It is concluded that this technique of vacuum brazing plus HIPping could be used for encapsulation-free HIPping to produce complex-shaped components.

  13. Effect of cold isostatic pressing on the transport current of filamentary MgB2 wire made by the IMD process

    Kováč, P.; Hušek, I.; Pachla, W.; Melišek, T.; Kulich, M.; Rosová, A.; Kopera, L.

    2016-07-01

    This work describes the effect of cold isostatic pressing applied to as-drawn filamentary wires in a GlidCop and/or Cu sheath made by the internal magnesium diffusion process. Critical currents of as-drawn and isostatically pressed wires at high pressures up to 2.0 GPa followed by heat treatment at 640 °C for 40 min were measured. The obtained results show an improvement in boron powder density resulting in an increase of the critical current of MgB2 layers. The engineering current density increases by 4–13 times after the high-pressure treatment, and is influenced by the density of the boron powder and by the mechanical strength of the outer sheath.

  14. Inversion defects in MgAl2O4 elaborated by pressureless sintering, pressureless sintering plus hot isostatic pressing, and spark plasma sintering

    The distribution of inversion defects of Al was investigated in dense magnesium-aluminate spinel elaborated by pressureless sintering, pressureless sintering plus hot isostatic pressing, and spark plasma sintering. This study was conducted by energy electron loss spectroscopy analyses and more particularly by energy loss near edge structure investigations of the Al-L2,3 edge. Several aspects are discussed with the purpose of understanding why charged defects dispersal reveals a special configuration.

  15. Influence of Lubricants and Attrition Milling Parameters on the Quality of Zirconolite Ceramics, Consolidated by Hot Isostatic Pressing, for Immobilization of Plutonium

    Squire, J.; Maddrell, E.R; Hyatt, N. C.; Stennett, M. C.

    2014-01-01

    The effect of attrition milling on the processing of precursor oxides was investigated, with reference to the fabrication of titanate ceramics for the immobilization of plutonium and actinides, consolidated by hot isostatic pressing. Difficulties encountered during the lubricant removal step masked any correlation between the milling conditions and the final product. Four lubricants were investigated zinc stearate, Ceridust™, polyethylene glycol and oleic acid. The precursor blends were added...

  16. Justification and manufacturing quality assurance for the use of hot Isostatically pressed, reactor coolant system components in PWR plant

    This paper presents an overview of the work undertaken by Rolls-Royce to introduce Hot Isostatically Pressed (HIP) components into Pressurised Water Reactor plant. It presents the work from a design justification and manufacturing quality assurance perspective, rather than from a pure metallurgical perspective, although some metallurgical and mechanical property comparisons with the traditional forged material are presented. Although the HIP process is not new, it was new in its application to Rolls-Royce designed nuclear reactor plant. In order to satisfy the regulatory requirement of 'Proven Engineering Practices' with regard to the introduction of new material processes, and to provide a robust manufacturing substantiation leg of a multi-legged safety case, Rolls-Royce has implemented an evolving, staged approach, starting with HIP bonding of solid valve seats into small bore valve pressure boundaries. This was followed by powder HIP consolidation of leak-limited, thin-walled toroids, and has culminated in the powder HIP consolidation of components, such as steam generator headers, large bore valves and pipe sections. The paper provides an overview of each of these stages and the approach taken with respect to justification. The paper describes the benefits that Rolls-Royce has realised so far through the introduction of HIPed components, and improvements planned for the future. Structural integrity benefits are described, such as improved grain structure, mechanical properties, and ultrasonic inspection. Project-based benefits are also described, such as provision of an alternative strategic sourcing route, cost and lead-time reduction. A full description is provided of key quality assurance steps applied to the process to ensure a high quality product is delivered commensurate with a high integrity nuclear application. 2008 Rolls-Royce plc. (authors)

  17. Sintering by hot isostatic pressing (HIP) and spark plasma sintering (SPS) of silicon carbide (SiC) nano-particles synthesized by laser pyrolysis pilot scale

    Pure or with sintering additives (Al2O3 + Y2O3) SiC nano-particles (20 nm) synthesised by laser pyrolysis at pilot scale were first cold pressed under 1 GPa and then sintered by Hot Isostatic Pressing (HIP) and Spark Plasma Sintering (SPS). Pure SiC samples densified by HIP have a higher density (95%) than SPS ones (80%). With help of sintering additives, both HIP and SPS samples are near theoretical density. Smaller grain size were observed for HIP pellets (pure ∼35 nm and with additives ∼100 to 200 nm). Whereas SPS samples grain size were between 100 nm and 1 m. A primary mechanical properties study demonstrates a hardness (28 GPa) and a toughness (6.5 MPa m1/2) optimum when crystallite size is around 200 nm. (authors)

  18. Warm isostatic pressing (WIP'ing) of GS44 Si{sub 3}N{sub 4} FDC parts for defect removal

    Wu Suxing; Rangarajan, Sriram; Dai Cheng; McCuiston, Ryan; Langrana, Noshir A.; Safari, Ahmad; Danforth, Stephen C.; Clancy, Richard B.; Whalen, Philip J

    2003-12-15

    Fused deposition of ceramics (FDC) is one of the developing solid freeform fabrication (SFF) techniques. The successful production of high performance ceramics by the FDC process requires that no defects exist in the green parts. However, build defects, such as missing roads, poorly bonded layers or sub-perimeter voids can be encountered in improperly built FDC parts. In this study, a method known as WIP'ing (warm isostatic pressing) was evaluated for its ability to eliminate existing defects in GS44 Si{sub 3}N{sub 4} green FDC parts. Analogous to CIP'ing (cold isostatic pressing), the green FDC parts were rubber bagged and loaded into a pressure chamber filled with water soluble oil at different temperatures, ranging from 30 to 90 deg. C, at pressures of up to 35 MPa. X-Ray radiography results indicated that at temperatures above 70 deg. C, WIP'ing was effective in closing the gaps of the intentionally placed void defects in FDC parts. However, WIP'ing above 70 deg. C was not effective in healing the defects completely. The fracture strengths of FDC parts with intentional added defects, WIP'ed above 70 deg. C were substantially lower than control samples.

  19. Comparative study: sensitization development in hot-isostatic-pressed cast and wrought structures type 316L(N)-IG stainless steel under isothermal heat treatment

    This work focuses on the relative sensitization resistance of type 316L(N)-IG stainless steel (SS). Cast and wrought structures SS after solid hot-isostatic pressing (solid-HIP) operation are investigated under isothermal heat treatment. Wrought SS/SS solid-HIP joint sensitization is taken also into consideration. These experiments employed the quantitative double-loop electrochemical potentiokinetic reactivation (DL-EPR) and oxalic acid etch screening tests. A copper-copper sulfate-16% sulfuric acid test applied for strongly sensitized cast SS to reinforce the results were received by the methods mentioned above. Results from all employed methods correlate well. Sensitization was detected neither in cast nor in wrought SS in as-HIPed condition excluding wrought SS/SS solid-HIP joints. Significant difference between sensitization development rates was determined in cast and wrought SS structures when annealing at 675 deg. C for a duration up to 50 h

  20. Effect of hot isostatic pressing on the structure and properties of cast polycrystalline gas-turbine blades made of nickel superalloys

    Beresnev, A. G.

    2012-05-01

    A concept of a two-stage hot isostatic pressing (HIP) cycle is developed for castings made of nickel superalloys in order to minimize plastic deformation and the recrystallization ability of their structure. At the first stage of the cycle, diffusion pore dissolution is predominant due to the motion of vacancies toward grain boundaries in a polycrystal; at the second stage, retained coarse pores are filled during plastic deformation. The effect of uniform compression pressure during HIP and microstructure defects on the vacancy diffusion in nickel superalloys is estimated. A two-stage HIP regime is developed for processing of cast gas-turbine engine blades made of a ZhS6U alloy in order to substantially decrease the shrinkage porosity and to increase the high-temperature characteristics, including the creep and fatigue resistance.

  1. Formation of ultra-fine grained TiC-dispersed SUS316L by ball-milling and their consolidation by hot isostatic pressing

    In order to overcome the irradiation embrittlement in austenitic stainless steels, ultra-fine grained SUS316L steels with very fine TiC particles have been developed. The SUS316-TiC nanocomposite powders having 1.0 to 2.0 mass%TiC were prepared by ball-milling SUS316-TiC powder mixtures for 125h in an argon gas atmosphere. The milled powders were consolidated by hot isostatic pressing (HIP) under a pressure of 200 MPa at temperature between 700-1000degC, and the bulk materials with crystallite size ranging between 100-400 nm have been produced. The possibility of using fine-grained TiC particles for pinning grain boundaries and thereby to maintain the ultra-fine grained structures has been discussed. (author)

  2. Compressive behavior of NiAl/(Cr,Mo)Hf alloy prepared by high-pressure die casting and hot isostatic pressing

    DU Xing-hao; GUO Jian-ting; WU Bao-lin

    2006-01-01

    The NiAl-28Cr-5.85Mo-0.15Hf alloy was prepared by high-pressure die casting (HPDC) and subsequent hot isostatic pressing(HIP), and tested for compressible strength and fracture behavior at 300-1 373 K. The results show that the elevated temperature 0.2% compressible yield strength as well as the room-temperature compressible fracture strain of as-HIP alloy are larger than those of the same alloy prepared by directional solidification (DS). It suggests that the fine structures with a homogeneous distribution of fine Cr(Mo)and Hf-rich phase created by high-pressure die casting lead to these improvements.

  3. Understanding the Role of Hot Isostatic Pressing Parameters on the Microstructural Evolution of Ti-6Al-4V and Inconel 718 Fabricated by Electron Beam Melting

    Peter, William H [ORNL; Nandwana, Peeyush [ORNL; Kirka, Michael M [ORNL; Dehoff, Ryan R [ORNL; Sames, William [Texas A& M University; ERDMAN III, DONALD L [ORNL; Eklund, Anders [Avure Technologies, Inc.; Howard, Ron [Avure Technologies, Inc.

    2015-04-01

    In this project, Avure and ORNL evaluated the influence of hot isostatic pressing (HIP) and thermal cycling as standalone post processing techniques on the microstructure of electron beam powder bed deposited Ti-6Al-4V and Inconel 718 alloys. Electron beam powder bed deposition is an effective technology for fabricating complex net shape components that cannot be manufactured with conventional processes. However, material deposited by this technology results in columnar grain growth which is detrimental for many applications. For Ti-6Al-4V, it has been found that thermal cycling alone is not sufficient to breakdown the columnar microstructure that is typical of electron beam powder bed technology. HIP, on the other hand, has the potential to be an effective technique to break down the columnar microstructure of Ti-6Al-4V into a more equiaxed and refined β grain structure, and provide a more homogeneous microstructure compared to the thermally cycled samples. Overall, the project showed that hot isostatic pressing reduced/eliminated porosity in both Ti-6Al-4V and Inconel 718 However, based on the unique thermal cycle and the application of pressure in the HIP vessel, Ti-6Al-4V e-beam deposited microstructures were modified from columnar grain growth to equiaxed microstructures; a significant outcome to this collaboration. Inconel 718, on the other hand, shows no change in the macrostructure as a result of the current HIP cycle based on the thermal history, and would require further investigation. Though the results of HIP cycle were very good at changing the microstructure, further development in optimizing the post heat treatments and HIP cycles is required to improve mechanical properties.

  4. Manufacture and Cytotoxicity of a Lead-free Piezoelectric Ceramic as a Bone Substitute—Consolidation of Porous Lithium Sodium Potassium Niobate by Cold Isostatic Pressing

    Wang, Qi; Yang, Jun; Zhang, Wu; Khoie, Roxanne; Li, Yi-ming; Zhu, Jian-guo; Chen, Zhi-qing

    2009-01-01

    Aim The piezoelectric properties and cytotoxicity of a porous lead-free piezoelectric ceramic for use as a direct bone substitute were investigated. Methodology Cold isostatic pressing (CIP) was applied to fabricate porous lithium sodium potassium niobate (Li0.06Na0.5K0.44) NbO3 specimens using a pore-forming method. The morphologies of the CIP-processed specimens were characterized and compared to those of specimens made by from conventional pressing procedures. The effects of the ceramic on the attachment and proliferation of osteoblasts isolated from the cranium of 1-day-old Sprague-Dawley rats were examined by a scanning electron microscopy (SEM) and methylthiazol tetrazolium (MTT) assay. Results The results showed that CIP enhanced piezoelectricity and biological performance of the niobate specimen, and also promoted an extracellular matrix-like topography of it. In vitro studies showed that the CIP-enhanced material had positive effects on the attachment and proliferation of osteoblasts. Conclusion Niobate ceramic generated by CIP shows a promise for being a piezoelectric composite bone substitute. PMID:20687302

  5. Isostatic hot-pressing mechanism maps for pure and natural sodium chloride - applications to nuclear waste isolation in bedded and domal salt formations

    The Waste Isolation Pilot Plant (WIPP) is a US Department of Energy research and development facility which is intended to demonstrate the safe geologic disposal of transuranic wastes. In this paper, the model for isostatic hot-pressing which was developed by Helle et al. is applied to the problem of compaction of both pure NaCl and natural (WIPP) salt to develop a model capable of predicting densification rates as a function of temperature and applied pressure. Calculations for pure dry NaCl suggest that under conditions in situ, the contribution to densification by diffusional processes is negligible; all compaction will occur by dislocation creep. Assuming then that compaction will occur only by dislocation processes, the model is extended to nominally dry, WIPP rock salt. Model predictions are shown to agree favourably with available test data, and the kinds of laboratory tests that may be done to validate the model are discussed. Hot-pressing mechanism maps for dry WIPP salt under anticipated repository conditions indicate that fractional densities in excess of 0.95 are attained in about 30 yr. At this density, connected porosity , and hence permeability, diminish rapidly, and the recompacted salt can begin to serve as an effective seal material. This prediction underestimates consolidation rates in situ, because moist salt will compact even more rapidly. It will be shown how the model may be extended to include the effects of brine on densification rates. (author)

  6. Hot-isostatic pressing of U-10Zr by grain boundary diffusion and creep cavitation. Part 2: Theory and data analysis

    Uranium-10 wt % zirconium (U-10Zr) is a fuel alloy that has been used in the Experimental Breeder Reactor-II (EBR-II). The high burnup that was desired in this fuel system made high demands on the mechanical compatibility between fuel and cladding both during normal operation and during safety-related transients when rapid differential expansion may cause high stresses. In general, this mechanical stress can be reduced by cladding deformation if the cladding is sufficiently ductile at high burnup, and/or by fuel hot-pressing. Fortunately, the fuel is very porous when it contacts the cladding, but this porosity gradually fills with solid fission products (primarily lanthanides) that may limit the fuel's compressibility. If the porosity remains open, gaseous fission products are released and the porous fuel creeps rather than hot-presses under contact stresses. If the pores are closed by sintering or by solid fission products, the porous fuel will hot-isostatic press (HIP), as represented by the models to be discussed. HIP experiments performed at 700 C on U-10Zr samples with different impurity phase contents (Part 1) are analyzed in terms of several creep cavitation models. The coupled diffusion/creep cavitation model of Chen and Argon shows good quantitative agreement with measured HIP rates for hydride- and metal-derived U-10Zr materials, assuming that pores are uniformly distributed on grain boundaries and are of modal size, and that far-field strain rates are negligible. The analysis predicts, for the first time, an asymmetry between HIP and swelling at identical pressure-induced driving forces due to differences in grain boundary stresses. The differences in compressibility of hydride- and metal-derived U-10Zr can be partially explained by differences in pore size and spacing. The relevance of the experiments to description of in-reactor densification under external pressure or contact stress due to fuel/cladding mechanical interaction is discussed

  7. Afterglow performance enhancement and mechanism studies on Y2O2S:Eu,Mg,Ti prepared via cold isostatic pressing

    Highlights: • The long-afterglow material is process-dependent. • We adopt a modified sulphide-fusion route to synthesise Y2O2S:Eu,Mg,Ti. • The afterglow results from Ti-related defects and Ti also creates harmful defects. • The Mg2+ ions effectively modulate the depth and concentration of the traps. • The codoping of Mg2+–Ti4+ ion pairs reduces the harmful defects. -- Abstract: A Y2O2S:Eu,Mg,Ti material was prepared via a modified sulphide-fusion route. Compared with the traditional solid-state reaction method, the obtained Y2O2S:Eu,Mg,Ti showed smaller, more uniform particles with higher brightness. The afterglow mechanism study indicated that the long-afterglow material is process-dependent and that its performance is determined by recipe, preparation technology and process used. The luminescence centres of Y2O2S:Ti; Y2O2S:Eu,Ti and Y2O2S:Eu,Mg,Ti are Ti4+ ions, Ti4+ + Eu3+ ions and Ti4+ + Eu3+ ions, respectively. The afterglow decay curve cannot be fitted using the exponential equation or first-, second-, third-order exponential decay multiple equations beyond 30 min. The afterglow luminescence of the materials resulted from Ti-related defects that make up two new trap levels. Ti doping created numerous harmful companying defects that decrease luminescence efficiency. Doping of Mg2+ ions facilitated the introduction of Ti4+ ions into the Y2O2S lattice to effectively modulate the depth and concentration of the trap. Doping of Mg2+–Ti4+ ion pairs reduced the number of harmful defects through the formation of a compensation-type hetero-valent substitution solid solution that greatly enhance the afterglow performance. Cold isostatic pressing promoted the entry of Ti ions into the Y2O2S crystal lattice and eliminated defects, such as preferred orientation. In addition, cold isostatic pressing reduced the E2 to 0.9 eV, which is beneficial to the long afterglow of the resulting material at room temperature

  8. Development of ultra high strength nano-Y2O3 dispersed ferritic steel by mechanical alloying and hot isostatic pressing

    Highlights: → Nano-Y2O3 dispersed FeCrTiAl ferritic alloys developed by mechanical alloying. → Over 99% density (7.32-7.38 Mg/m3) achieved by hot isostatic pressing. → Dispersion of nanometric Y2Ti2O7, Y2O3, Fe11TiY or Al9.22Cr2.78Y is uniform. → Extremely high compressive strength, modulus, fracture toughness, hardness achieved. → Compressive strength is 2-3 times higher with lower density than similar ODS steel. - Abstract: The present investigation aims to develop ultra high strength ferritic steels through consolidation of mechanically alloyed powders of 1.0 wt% nano-Y2O3 dispersed 83.0Fe-13.5Cr-2.0Al-0.5Ti (alloy A), 79.0Fe-17.5Cr-2.0Al-0.5Ti (alloy B), 75.0Fe-21.5Cr-2.0Al-0.5Ti (alloy C) and 71.0Fe-25.5Cr-2.0Al-0.5Ti (alloy D) alloys (all in wt%) by hot isostatic pressing (HIP) at 600, 800 and 1000 deg. C using 1.2 GPa pressure for 1 h. Following this mechano-chemical synthesis and consolidation, extensive effort has been undertaken to characterize the microstructural evolution by X-ray diffraction, scanning and transmission electron microscopy and energy dispersive spectroscopy. Mechanical properties including hardness, compressive strength, Young's modulus and fracture toughness were determined using nano-indentation and universal testing machine. The present ferritic alloys record extraordinary levels of compressive strength (2012-3325 MPa), Young's modulus (230-295 GPa), fracture toughness (4.6-21.8 MPa √m) and hardness (15.5-19.7 GPa), and measure up to 2-3 times greater strength with a lower density (∼7.4 Mg/m3) than that of other oxide dispersion strengthened ferritic steels (2O3 (ex situ) or Y2Ti2O7 (in situ) particles in higher volume fraction in high-Cr ferritic matrix.

  9. Combining Aluminum Heat Treat with Hot Isostatic Pressing:A Comparison of Structure, Properties, and Processing Routes for a Cast Al-Si-Mg Alloy

    Stephen J. Mashl

    2004-01-01

    Bodycote researchers have successfully demonstrated that a T6 heat treatment can be integrated with Densal(R), a proprietary, aluminum specific, hot isostatic pressing (HIP) process. In this combined operation, at least a portion of the solution heat treatment is conducted at elevated pressure. During development, two issues, adiabatic cooling during depressurization and a possible variation in the kinetics of homogenization resulting from conducting the solution heat treat at elevated pressure were perceived as factors which could alter the heat treat response fiom that seen in conventional processing.This paper reviews the results of experiments performed to A1-Si-Mg (A356.0) castings subjected to both combined and conventional processing routes. Results indicate that the combined HIP and heat treat process is an efficient means of achieving a microstructure characteristic of a conventionally T6 processed material while eliminating porosity within the casting. Further, the fatigue life of an A356.0 casting processed using the combined cycle can be improved by more than an order of magnitude over the as-cast and T6 treated component.

  10. Development of manufacturing technology of radial plate in superconducting coil for fusion reactor by diffusion bonding by Hot Isostatic Pressing (HIP)

    The radial plates (RPs), which is used in Toroidal field (TF) coil in ITER, are quite large, such as 13 m tall and 9 m wide, but thin, such as 10 cm thick, and are made of stainless steel. Even though they are very large structures, they require very high manufacturing tolerances and high mechanical strength at 4 K. The similar requirements will be required in the next generation fusion reactor. Therefore, the authors intend to develop efficient manufacturing methods in parallel with ITER TF coil RP manufacture. The authors therefore performed trial manufacture of the RP segments using a diffusion bonding method, namely Hot Isostatic Pressing (HIP). As a result of trials, it was clarified that even when HIPping is applied, the mechanical characteristic of base metal is not deteriorated. The machining period can be reduced by about 1/3 compared with the traditional manufacturing method. On the other hand, mechanical strength at 4 K is degraded due to weak bonding, that is no grain growth through joint, by HIPping. However, additional test indicates promising possibility of much better joint by higher temperature and joint surface treated HIPpings. These results justified that RP segment manufacturing is not only possible, but it is a technically valid manufacturing method that satisfies all requirements. (author)

  11. Effect of Oxygen Content Upon the Microstructural and Mechanical Properties of Type 316L Austenitic Stainless Steel Manufactured by Hot Isostatic Pressing

    Cooper, Adam J.; Cooper, Norman I.; Dhers, Jean; Sherry, Andrew H.

    2016-09-01

    Although hot isostatic pressing (HIP) has been shown to demonstrate significant advances over more conventional manufacture routes, it is important to appreciate and quantify the detrimental effects of oxygen involvement during the HIP manufacture process on the microstructural and material properties of the resulting component. This paper quantifies the effects of oxygen content on the microstructure and Charpy impact properties of HIP'd austenitic stainless steel, through combination of detailed metallographic examination and mechanical testing on HIP'd Type 316L steel containing different concentrations (100 to 190 ppm) of oxygen. Micron-scale pores were visible in the microstructure of the HIP'd materials postmetallographic preparation, which result from the removal of nonmetallic oxide inclusions during metallographic preparation. The area fraction of the resulting pores is shown to correlate with the oxygen concentration which influences the Charpy impact toughness over the temperature range of 77 K to 573 K (-196 °C to 300 °C), and demonstrates the influence of oxygen involved during the HIP manufacture process on Charpy toughness. The same test procedures and microstructural analyses were performed on commercially available forged 316L. This showed comparatively fewer inclusions and exhibited higher Charpy impact toughness over the tested temperature range.

  12. Isostatic hot-pressing mechanism maps for pure and natural sodium chloride: Applications to nuclear waste isolation in bedded and domal salt formations

    The mechanical behavior of crushed rock salt is of interest to the WIPP Project because the mined WIPP salt is a candidate material for use as backfill around the waste packages and in the underground openings during and after the operational phase. It is anticipated that in response to the convergence of the mine openings, the crushed salt will compact sufficiently to serve as an effective component in WIPP seal systems. In this report, the model for isostatic hot-pressing is applied to the problem of compaction of both pure sodium chloride and natural (WIPP) salt to develop a model capable of predicting densification rates as a function of temperature and applied pressure. Calculations for pure dry salt suggest that under conditions in situ, the contribution to densification by diffusional processes is negligible; all compaction will occur by dislocation creep. Assuming then that compaction will occur only by dislocation processes, the model is extended to nominally dry, WIPP salt. Model predictions are shown to agree favorably with limited test data, and the kinds of laboratory tests that may be done to validate the model are discussed. 78 refs., 13 figs., 2 tabs

  13. Sintering of ZrC by hot isostatic pressing (HIP) and spark plasma sintering (SPS). Effect of impurities

    Allemand, Alexandre [CEA Saclay, DRT/DTEN/S3ME/LTMEx, 91191 Gif-sur-Yvette (France); Le Flem - Dormeval, Marion [CEA Saclay, DEN/DMN/SRMA/LA2M, 91191 Gif-sur-Yvette (France); Guillard, Francois [CNRS-CEMES-CMI, 29 rue J.Marving, 31000 Toulouse (France)

    2005-07-01

    Carbides are generally used as structural materials for high temperature applications. Particularly, ZrC because of low activation, neutronic transparency, cubic structure (isotropic behaviour) and good thermal conductivity, is one of the candidates under consideration for structural materials in the core of new high temperature nuclear reactors (Generation IV). Just a few studies about densification of monolithic ZrC exist. They mainly involve natural sintering or hot pressing at high temperature (until 2700 deg. C). Unfortunately those processes induce grain growth and do not lead to fully densified ZrC. The aim of this study is to compare the characteristics and the properties of ZrC sintered by HIP and by SPS. Fully dense ZrC can be reached either by HIP or by SPS, grain size being more or less controlled. Microstructural observations and mechanical testing of several ZrC grades shows that powder impurities play an important role in the quality of the grain boundaries and consequently in the mechanical properties. In particular, the porosity falls from 17% to 3 % just by reducing the free carbon content in starting ZrC powder. The densification process of dense monolithic ZrC was improved by combining a HIP at 1600 deg. C (titanium canning) followed by a post-HIP at 1900 deg. C (no canning required). Four-point bending tests are in progress to confirm the improvement of fracture strength. (authors)

  14. Sintering of ZrC by hot isostatic pressing (HIP) and spark plasma sintering (SPS). Effect of impurities

    Carbides are generally used as structural materials for high temperature applications. Particularly, ZrC because of low activation, neutronic transparency, cubic structure (isotropic behaviour) and good thermal conductivity, is one of the candidates under consideration for structural materials in the core of new high temperature nuclear reactors (Generation IV). Just a few studies about densification of monolithic ZrC exist. They mainly involve natural sintering or hot pressing at high temperature (until 2700 deg. C). Unfortunately those processes induce grain growth and do not lead to fully densified ZrC. The aim of this study is to compare the characteristics and the properties of ZrC sintered by HIP and by SPS. Fully dense ZrC can be reached either by HIP or by SPS, grain size being more or less controlled. Microstructural observations and mechanical testing of several ZrC grades shows that powder impurities play an important role in the quality of the grain boundaries and consequently in the mechanical properties. In particular, the porosity falls from 17% to 3 % just by reducing the free carbon content in starting ZrC powder. The densification process of dense monolithic ZrC was improved by combining a HIP at 1600 deg. C (titanium canning) followed by a post-HIP at 1900 deg. C (no canning required). Four-point bending tests are in progress to confirm the improvement of fracture strength. (authors)

  15. Properties of 8-inch photomultiplier tubes for a large volume imaging water Cerenkov detector; Untersuchung der Eigenschaften hemisphaerischer 8-inch Photomultiplier fuer einen grossvolumigen Wasser-Cerenkov-Detektor

    Oehler, C.

    1996-01-01

    In the Institut fuer Kernphysik I conceptional studies for a possible succession project for the KARMEN-{nu}-detector are performed. This design studies propose to build a large volume 1300 t imaging water Cerenkov detector. The main goal of this experiment will be the investigation of {nu}-e{sup -}-scattering in the medium energy range up to 50 MeV. The sensitive surface of this detector will be instrumented with about 3000 8-inch photomultiplier tubes (PMT) providing a coverage of 20%. In the framework of this detector design, studies of the properties of hemispherical 8-inch phototubes have been investigated in this work. The topic was to optimise the quality of the important PMT properties like time- and energy-resolution which are crucial to achieve the required spatial and angular resolutions. A second task of this work was to construct a test facility for the PMT, with the possibility to test large quantities. Monte Carlo calculations show that the required detector resolutions of {sigma}{sub E}/E(E{sub e}{<=}50 MeV)=5.2%+47%/{radical}E, {sigma}{sub t}(E{sub e}{approx}30 MeV)=0.6 ns, {sigma}{sub x}(E{sub e}{approx}30 MeV)=13 cm, {sigma}{sub {Theta}}(E{sub e}{approx}30 MeV)=20 , can be achieved if the phototubes have a transit-time spread less than 1 ns. Up to now, two different 8-inch tubes are available and have been tested, the HAMAMATSU R5912 and the EMI 9353. (orig.)

  16. Growth kinetics and microstructural evolution during hot isostatic pressing of U-10 wt.% Mo monolithic fuel plate in AA6061 cladding with Zr diffusion barrier

    Phase constituents and microstructure changes in RERTR fuel plate assemblies as functions of temperature and duration of hot-isostatic pressing (HIP) during fabrication were examined. The HIP process was carried out as functions of temperature (520, 540, 560 and 580 °C for 90 min) and time (45–345 min at 560 °C) to bond 6061 Al-alloy to the Zr diffusion barrier that had been co-rolled with U-10 wt.% Mo (U10Mo) fuel monolith prior to the HIP process. Scanning and transmission electron microscopies were employed to examine the phase constituents, microstructure and layer thickness of interaction products from interdiffusion. At the interface between the U10Mo and Zr, following the co-rolling, the UZr2 phase was observed to develop adjacent to Zr, and the α-U phase was found between the UZr2 and U10Mo, while the Mo2Zr was found as precipitates mostly within the α-U phase. The phase constituents and thickness of the interaction layer at the U10Mo-Zr interface remained unchanged regardless of HIP processing variation. Observable growth due to HIP was only observed for the (Al,Si)3Zr phase found at the Zr/AA6061 interface, however, with a large activation energy of 457 ± 28 kJ/mole. Thus, HIP can be carried to improve the adhesion quality of fuel plate without concern for the excessive growth of the interaction layer, particularly at the U10Mo-Zr interface with the α-U, Mo2Zr, and UZr2 phases

  17. Manufacturing and mechanical property test of the large-scale oxide dispersion strengthened martensitic mother tube by hot isostatic pressing and hot extrusion process

    Mass production capability of Oxide Dispersion Strengthened (ODS) ferritic steel cladding (9Cr) is evaluated in the Phase II of the Feasibility Studies on Commercialized Fast Reactor Cycle System. The cost for manufacturing mother tube is a dominant factor in the total cost for manufacturing ODS ferritic cladding. In this study, the large-scale 9Cr-ODS martensitic mother tube was produced by overseas supplier with mass production equipments for commercialized ODS steels. The process of manufacturing the ODS mother tube consists of raw material powder production, mechanical alloying by high energy ball mill, hot isostatic pressing(HIP), and hot extrusion. Following results were obtained in this study. (1) Micro structure of the ODS steels is equivalent to that of domestic products, and fine oxides are uniformly distributed. The mechanical alloying by large capacity (1 ton) ball mill can be satisfactorily carried out. (2) A large scale mother tube (65 mm OD x 48 mm ID x 10,000 mm L), which can produce about 60 pieces of 3 m length ODS ferritic claddings by four times cold rolling, have been successfully manufactured through HIP and Hot Extrusion process. (3) Rough surface of the mother tubes produced in this study can be improved by selecting the reasonable hot extrusion condition. (4) Hardness and tensile strength of the manufactured ODS steels are lower than domestic products with same chemical composition. This is owing to the high aluminum content in the product, and those properties could be improved by decreasing the aluminum content in the raw material powder. (author)

  18. Properties of 8-inch photomultiplier tubes for a large volume imaging water Cerenkov detector

    In the Institut fuer Kernphysik I conceptional studies for a possible succession project for the KARMEN-ν-detector are performed. This design studies propose to build a large volume 1300 t imaging water Cerenkov detector. The main goal of this experiment will be the investigation of ν-e--scattering in the medium energy range up to 50 MeV. The sensitive surface of this detector will be instrumented with about 3000 8-inch photomultiplier tubes (PMT) providing a coverage of 20%. In the framework of this detector design, studies of the properties of hemispherical 8-inch phototubes have been investigated in this work. The topic was to optimise the quality of the important PMT properties like time- and energy-resolution which are crucial to achieve the required spatial and angular resolutions. A second task of this work was to construct a test facility for the PMT, with the possibility to test large quantities. Monte Carlo calculations show that the required detector resolutions of σE/E(Ee≤50 MeV)=5.2%+47%/√E, σt(Ee∼30 MeV)=0.6 ns, σx(Ee∼30 MeV)=13 cm, σΘ(Ee∼30 MeV)=20 , can be achieved if the phototubes have a transit-time spread less than 1 ns. Up to now, two different 8-inch tubes are available and have been tested, the HAMAMATSU R5912 and the EMI 9353. (orig.)

  19. First thin AC-coupled silicon strip sensors on 8-inch wafers

    Bergauer, T.; Dragicevic, M.; König, A.; Hacker, J.; Bartl, U.

    2016-09-01

    The Institute of High Energy Physics (HEPHY) in Vienna and the semiconductor manufacturer Infineon Technologies Austria AG developed a production process for planar AC-coupled silicon strip sensors manufactured on 200 μm thick 8-inch p-type wafers. In late 2015, the first wafers were delivered featuring the world's largest AC-coupled silicon strip sensors. Detailed electrical measurements were carried out at HEPHY, where single strip and global parameters were measured. Mechanical studies were conducted and the long-term behavior was investigated using a climate chamber. Furthermore, the electrical properties of various test structures were investigated to validate the quality of the manufacturing process.

  20. Am/Cm TTR testing - 3/8-inch glass beads evaluation in CIM5

    To facilitate the procurement and handling of the glass former for Am/Cm vitrification in the F-Canyon MPPF, 1/4 inch and 3/8 inch diameter glass beads were purchased from Corning for evaluation in the 5 inch Cylindrical Induction Melter (CIM5). Prior to evaluating the beads in the CIM5, tests were conducted in the Drain Tube Test Stand (DTTS) with 1/4 inch beads, 3/8 inch beads, and a 50/50 mixture to identify any process concerns. Results of the DTTS tests are summarized in Attachment 1. A somewhat larger volume expansion was experienced in all three DTTS runs as compared to a standard run using cullet. Further testing of the use of glass beads in the CIM5 was requested by the Design Authority as Task 1.02 of Technical Task Request 99-MNSS/SE-006. Since the Technical Task Plan was not yet approved, the completion of this task was conducted under an authorization request approved by the SRTC Laboratory Director, S. Wood. This request is included as Attachment 2

  1. Characterization of Large Volume 3.5 x 8 inches LaBr3:Ce Detectors

    Giaz, A; Riboldi, S; Camera, F; Blasi, N; Boiano, C; Bracco, A; Brambilla, S; Ceruti, S; Coelli, S; Crespi, F C L; Csatlòs, M; Frega, S; Gulyàs, J; Krasznahorkay, A; Lodetti, S; Million, B; Owens, A; Quarati, F; Stuhl, L; Wieland, O

    2013-01-01

    The properties of large volume cylindrical 3.5 x 8 inches (89 mm x 203 mm) LaBr3:Ce scintillation detectors coupled to the Hamamatsu R10233-100SEL photo-multiplier tube were investigated. These crystals are among the largest ones ever produced and still need to be fully characterized to determine how these detectors can be utilized and in which applications. We tested the detectors using monochromatic gamma-ray sources and in-beam reactions producing gamma rays up to 22.6 MeV; we acquired PMT signal pulses and calculated detector energy resolution and response linearity as a function of gamma-ray energy. Two different voltage dividers were coupled to the Hamamatsu R10233-100SEL PMT: the Hamamatsu E1198-26, based on straightforward resistive network design, and the LABRVD, specifically designed for our large volume LaBr3:Ce scintillation detectors, which also includes active semiconductor devices. Because of the extremely high light yield of LaBr3:Ce crystals we observed that, depending on the choice of PMT, v...

  2. Design evaluation of the 20-cm (8-inch) secondary burner system

    Rode, J.S.

    1977-08-01

    This report describes an evaluation of the design of the existing 20-cm (8-inch) engineering-scale secondary burner system in the HTGR reprocessing cold pilot plant at General Atomic Co. The purpose of this evaluation is to assess the suitability of the existing design as a prototype of the HTGR Recycle Demonstration Facility (HRDF) secondary burner system and to recommend alternatives where the existing design is thought to be unsuitable as a prototype. This evaluation has led to recommendations for the parallel development of two integrated design concepts for a prototype secondary burner system. One concept utilizes the existing burner heating and cooling subsystems in order to minimize development risk, but simplifies a number of other features associated with remote maintenance and burner operation. The other concept, which offers maximum cost reduction, utilizes internal gas cooling of the burner, retains the existing heating subsystem for design compatibility, but requires considerable development to reduce the risk to acceptable limits. These concepts, as well as other design alternatives, are described and evaluated.

  3. Performance of new 8-inch photomultiplier tube used for the Tibet muon-detector array

    Huang, Ying Zhangm Jing; Zhai, Liu-Ming; Chen, Xu; Hu, Xiao-Bin; Lin, Yu-Hui; Zhang, Xue-Yao; Feng, Cun-Feng; Jia, Huan-Yu; Zhou, Xun-Xiu; Dan-Zen, Luo-bu; Chen, Tian-Lu; Laba, Ci-Ren; Mao-Yuan,; Gao, Qi; Zha-xi, Ci-ren

    2016-01-01

    A new hybrid experiment has been constructed to measure the chemical composition of cosmic rays around the "knee" in the wide energy range by the Tibet AS$\\gamma$ collaboration at Tibet, China, since 2014. They consist of a high-energy air-shower-core array (YAC-II), a high-density air-shower array (Tibet-III) and a large underground water-Cherenkov muon-detector array (MD). In order to obtain the primary proton, helium and iron spectra and their "knee" positions in the energy range lower than $10^{16}$ eV, each of PMTs equipped to the MD cell is required to measure the number of photons capable of covering a wide dynamic range of 100 - $10^{6}$ photoelectrons (PEs) according to Monte Carlo simulations. In this paper, we firstly compare the characteristic features between R5912-PMT made by Japan Hamamatsu and CR365-PMT made by Beijing Hamamatsu. This is the first comparison between R5912-PMT and CR365-PMT. If there exists no serious difference, we will then add two 8-inch-in-diameter PMTs to meet our requirem...

  4. Performance of new 8-inch photomultiplier tube used for the Tibet muon-detector array

    Zhang, Y.; Huang, J.; Chen, D.; Zhai, L.-M.; Chen, X.; Hu, X.-B.; Lin, Y.-H.; Jin, H.-B.; Zhang, X.-Y.; Feng, C.-F.; Jia, H.-Y.; Zhou, X.-X.; Danzengluobu; Chen, T.-L.; Labaciren; Liu, M.-Y.; Gao, Q.; Zhaxiciren

    2016-06-01

    Since 2014, a new hybrid experiment consisting of a high-energy air-shower-core array (YAC-II), a high-density air-shower array (Tibet-III) and a large underground water-Cherenkov muon-detector array (MD) has been continued by the Tibet ASγ collaboration to measure the chemical composition of cosmic rays in the wide energy range including the ``knee''. In this experiment, YAC-II is used to select high energy core events induced by cosmic rays in the above energy region, while MD is used to estimate the type of nucleus of primary particles by measuring the number of muons contained in the air showers. However, the dynamic range of each MD cell is only 5 to 2000 photoelectrons (PEs) which is mainly designed for observation of high-energy celestial gamma rays. In order to obtain the primary proton, helium and iron spectra and their ``knee'' positions with energy up to 1016 eV, each of PMTs equipped to the MD cell is required to measure the number of photons capable of covering a wide dynamic range of 100–106 PEs according to Monte Carlo simulations. In this paper, we firstly compare the characteristic features between R5912-PMT made by Japan Hamamatsu and CR365-PMT made by Beijing Hamamatsu. If there exists no serious difference, we will then add two 8-inch-in-diameter PMTs to meet our requirements in each MD cell, which are responsible for the range of 100–10000 PEs and 2000–1000000 PEs, respectively. That is, MD cell is expected to be able to measure the number of muons over 6 orders of magnitudes.

  5. Isostatic compression of buffer blocks. Middle scale

    Manufacturing of buffer components using isostatic compression method has been studied in small scale in 2008 (Laaksonen 2010). These tests included manufacturing of buffer blocks using different bentonite materials and different compression pressures. Isostatic mould technology was also tested, along with different methods to fill the mould, such as vibration and partial vacuum, as well as a stepwise compression of the blocks. The development of manufacturing techniques has continued with small-scale (30 %) blocks (diameter 600 mm) in 2009. This was done in a separate project: Isostatic compression, manufacturing and testing of small scale (D = 600 mm) buffer blocks. The research on the isostatic compression method continued in 2010 in a project aimed to test and examine the isostatic manufacturing process of buffer blocks at 70 % scale (block diameter 1200 to 1300 mm), and the aim was to continue in 2011 with full-scale blocks (diameter 1700 mm). A total of nine bentonite blocks were manufactured at 70 % scale, of which four were ring-shaped and the rest were cylindrical. It is currently not possible to manufacture full-scale blocks, because there is no sufficiently large isostatic press available. However, such a compression unit is expected to be possible to use in the near future. The test results of bentonite blocks, produced with an isostatic pressing method at different presses and at different sizes, suggest that the technical characteristics, for example bulk density and strength values, are somewhat independent of the size of the block, and that the blocks have fairly homogenous characteristics. Water content and compression pressure are the two most important properties determining the characteristics of the compressed blocks. By adjusting these two properties it is fairly easy to produce blocks at a desired density. The commonly used compression pressure in the manufacturing of bentonite blocks is 100 MPa, which compresses bentonite to approximately

  6. Isostatic compression of buffer blocks. Middle scale

    Ritola, J.; Pyy, E. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2012-01-15

    Manufacturing of buffer components using isostatic compression method has been studied in small scale in 2008 (Laaksonen 2010). These tests included manufacturing of buffer blocks using different bentonite materials and different compression pressures. Isostatic mould technology was also tested, along with different methods to fill the mould, such as vibration and partial vacuum, as well as a stepwise compression of the blocks. The development of manufacturing techniques has continued with small-scale (30 %) blocks (diameter 600 mm) in 2009. This was done in a separate project: Isostatic compression, manufacturing and testing of small scale (D = 600 mm) buffer blocks. The research on the isostatic compression method continued in 2010 in a project aimed to test and examine the isostatic manufacturing process of buffer blocks at 70 % scale (block diameter 1200 to 1300 mm), and the aim was to continue in 2011 with full-scale blocks (diameter 1700 mm). A total of nine bentonite blocks were manufactured at 70 % scale, of which four were ring-shaped and the rest were cylindrical. It is currently not possible to manufacture full-scale blocks, because there is no sufficiently large isostatic press available. However, such a compression unit is expected to be possible to use in the near future. The test results of bentonite blocks, produced with an isostatic pressing method at different presses and at different sizes, suggest that the technical characteristics, for example bulk density and strength values, are somewhat independent of the size of the block, and that the blocks have fairly homogenous characteristics. Water content and compression pressure are the two most important properties determining the characteristics of the compressed blocks. By adjusting these two properties it is fairly easy to produce blocks at a desired density. The commonly used compression pressure in the manufacturing of bentonite blocks is 100 MPa, which compresses bentonite to approximately

  7. Effect of Hot Isostatic Pressing on Corrosion-Resistant Property of Aluminum Coating on Uranium Surface%热等静压处理对铀表面铝镀层耐腐蚀性能的影响

    王庆富; 张羽廷; 谢东华; 张鹏程; 刘婷婷

    2011-01-01

    采用热等静压(HIP)技术对铀表面铝镀层进行处理,利用电化学测试技术、扫描电镜(SEM)及X射线能谱(EDS)对样品在50 μL/L Cl的KC1水溶液中的电化学腐蚀行为进行研究.结果表明:200℃,0.5 h,60 MPa HIP处理的铝镀层耐腐蚀性能优于未处理镀层;480℃,1.0 h,60MPa HIP处理镀层的耐腐蚀性能下降较为明显;HIP处理后样品的腐蚀特征为典型的局部腐蚀,在腐蚀过程中会出现镀层的破裂、剥落.%Aluminum coating on the uranium surface was treated with hot isostatic pressing (HIP). Then the electrochemical corrosion behavior of samples in SO Μl/L Cl- K.C1 solution were investigated by electrochemical techniques, scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results indicate that the corrosion-resistant property of the aluminum coating HIPed at 200 °C, 0.S h, 60 Mpa is better than that of the untreated coating, while the corrosion-resistant property is decreased for the coating with HIP at 480 °C, 1.0 h, 60 Mpa. The corrosion characteristics of the HIPed aluminum coating is typical local corrosion, and the coating presents cracking and flaking off during corrosion process.

  8. Additive Manufacturing of Zirconia Parts via Selective Laser Sintering Combined with Cold Isostatic Pressing%氧化锆零件激光选区烧结/冷等静压复合成形技术

    史玉升; 刘凯; 李晨辉; 魏青松; 刘洁; 夏思婕

    2014-01-01

    氧化锆陶瓷材料以其优异的性能在工业生产中具有极大的应用前景,但由于脆性大、硬度高等原因,复杂形状氧化锆零件往往难以成形和加工。为了获得复杂形状氧化锆陶瓷零件,通过溶剂沉淀法将粘接剂尼龙12覆膜至纳米氧化锆粉末的表面,然后对覆膜后的粉体进行激光选区烧结(Selective laser sintering, SLS)成形,并通过传统的冷等静压(Cold isostatic pressing, CIP)技术对SLS零件进行致密化处理,同时满足氧化锆初坯成形时形状复杂度和密度的要求。通过试验得出在激光能量密度为0.415 J/mm2时,获得的SLS陶瓷件密度较大,对不同激光能量密度制备的SLS陶瓷件进行保压压力为200 MPa的冷等静压致密化处理,根据热脱脂机理以及粘接剂的TG曲线,分别制定了SLS/CIP试样的热脱脂工艺,最后对脱脂试样进行高温烧结,在后续处理的各环节,氧化锆零件的密度仍受SLS成形的影响,但该影响逐渐减弱,SLS/CIP/FS成形件最大相对密度和维氏硬度分别达到了97%和1180 HV1,已接近“模压-烧结”的致密氧化锆陶瓷的性能,在试样断口的扫描电子显微镜(SEM)分析基础上,对氧化锆复合成形的微观演变进行了研究。虽然最终烧结件密度和硬度仍有待提高,但是提出了一种极具潜力的氧化锆零件近净成形工艺方法,为制造高性能复杂形状的陶瓷零件奠定了基础。%Zirconia has great application prospect for its excellent properties in the industrial production. But due to high brittleness and hardness, complex shape zirconia parts are often difficult to form and machine. To obtain complex zirconia parts, nano-zirconia powder is coated by the binder nylon 12 by solvent precipitation method. Coated powder is then formed via selective laser sintering (SLS) combined with cold isostatic pressing (CIP). Through the experiment, when laser energy density is 0

  9. 氧化锆零件激光选区烧结/冷等静压复合成形技术%Additive Manufacturing of Zirconia Parts via Selective Laser Sintering Combined with Cold Isostatic Pressing

    史玉升; 刘凯; 李晨辉; 魏青松; 刘洁; 夏思婕

    2014-01-01

    Zirconia has great application prospect for its excellent properties in the industrial production. But due to high brittleness and hardness, complex shape zirconia parts are often difficult to form and machine. To obtain complex zirconia parts, nano-zirconia powder is coated by the binder nylon 12 by solvent precipitation method. Coated powder is then formed via selective laser sintering (SLS) combined with cold isostatic pressing (CIP). Through the experiment, when laser energy density is 0.415 J/mm2, SLS ceramics had the biggest density. The subsequent 200 MPa CIP process is carried out on SLS parts with different laser energy density. According to the thermal debinding mechanism and TG curve of the binder, the reasonable thermal debinding process is formulated respectively. After furnace sintering (FS), with the steps of subsequent processing increased, parts affected by the SLS forming process gradually weakened, the largest relative density and Vickers hardness of SLS/CIP/FS parts are respectively 97%and 1180 HV1, radial and axial shrinkage rate were 58.1% and 67.8% respectively, and fracture of specimens are analysed by scanning electron microscope (SEM). Although the final density and hardness of the ZrO2 are still to be improved, a potential technical method for manufacturing complex zirconia parts with high performance is provided.%氧化锆陶瓷材料以其优异的性能在工业生产中具有极大的应用前景,但由于脆性大、硬度高等原因,复杂形状氧化锆零件往往难以成形和加工。为了获得复杂形状氧化锆陶瓷零件,通过溶剂沉淀法将粘接剂尼龙12覆膜至纳米氧化锆粉末的表面,然后对覆膜后的粉体进行激光选区烧结(Selective laser sintering, SLS)成形,并通过传统的冷等静压(Cold isostatic pressing, CIP)技术对SLS零件进行致密化处理,同时满足氧化锆初坯成形时形状复杂度和密度的要求。通过试验得出在激光能量密度为0.415 J

  10. Sintering and hot isostatic post-densification of silicon carbide

    Silicon carbide has been mixed with additives of boron and/or aluminium with simultaneous addition of carbon, then it has been formed to bending bars by cold isostatic pressing. In point of density, microstructure and strength, the hot densification by pressureless sintering and hot isostatic post-densification showed comparable results as sintering and hot isostatic pressing in the same cycle (Sinter/HIP). For all chosen additives for SiC the obtained sintered density was sufficient for a post-densification. The boron additive caused increased grain growth during sintering and hot isostatic post-densification, which had a negative result on the bending strength. A too high post-densification temperature causes a decrease in strength while considerably coarsening the grain, too. By hot isostatic post-densification with argon as a pressure gas normally the strength level is increased, while the scattering of the data decreases simultaneously. A post-densification in nitrogen as pressure gas shows no advantage; however, surface defects seem to heal by a long-term annealing in N2-gas. If the Sinter/HIP process is controlled, this procedure offers economic advantages compared with sintering and post-densification in separate units. (orig.)

  11. Comparison of various isostatic marine gravity disturbances

    Robert Tenzer; Mohammad Bagherbandi; Lars E Sjöberg

    2015-08-01

    We present and compare four types of the isostatic gravity disturbances compiled at sea level over the world oceans and marginal seas. These isostatic gravity disturbances are computed by applying the Airy–Heiskanen (AH), Pratt–Hayford (PH) and Vening Meinesz–Moritz (VMM) isostatic models. In addition, we compute the complete crust-stripped (CCS) isostatic gravity disturbances which are defined based on a principle of minimizing their spatial correlation with the Moho geometry. We demonstrate that each applied compensation scheme yields a distinctive spatial pattern in the resulting isostatic marine gravity field. The AH isostatic gravity disturbances provide the smoothest gravity field (by means of their standard deviation). The AH and VMM isostatic gravity disturbances have very similar spatial patterns due to the fact that the same isostatic principle is applied in both these definitions expect for assuming a local (in the former) instead of a global (in the latter) compensation mechanism. The PH isostatic gravity disturbances are highly spatially correlated with the ocean-floor relief. The CCS isostatic gravity disturbances reveal a signature of the ocean-floor spreading characterized by an increasing density of the oceanic lithosphere with age.

  12. U.S. Isostatic Residual Gravity Grid

    National Oceanic and Atmospheric Administration, Department of Commerce — isores.bin - standard grid containing isostatic residual gravity map for U.S. Grid interval = 4 km. Projection is Albers (central meridian = 96 degrees West; base...

  13. Isostatic Model and Isostatic Gravity Anomalies of the Arabian Plate and Surroundings

    Kaban, Mikhail K.; El Khrepy, Sami; Al-Arifi, Nassir

    2016-04-01

    The isostatic modeling represents one of the most useful "geological" reduction methods of the gravity field. With the isostatic correction, it is possible to remove a significant part of the effect of deep density heterogeneity, which dominates in the Bouguer gravity anomalies. Although there exist several isostatic compensation schemes, it is usually supposed that a choice of the model is not an important factor to first order, since the total weight of compensating masses remains the same. We compare two alternative models for the Arabian plate and surrounding area. The Airy model gives very significant regional isostatic anomalies, which cannot be explained by the upper crust structure or disturbances of the isostatic equilibrium. Also, the predicted "isostatic" Moho is very different from existing seismic observations. The second isostatic model includes the Moho, which is based on seismic determinations. Additional compensation is provided by density variations within the lithosphere (chiefly in the upper mantle). According to this model, the upper mantle under the Arabian Shield is less dense than under the Platform. In the Arabian platform, the maximum density coincides with the Rub' al Khali, one of the richest oil basin in the world. This finding agrees with previous studies, showing that such basins are often underlain by dense mantle, possibly related to an eclogite layer that has caused their subsidence. The mantle density variations might be also a result of variations of the lithosphere thickness. With the combined isostatic model, it is possible to minimize regional anomalies over the Arabian plate. The residual local anomalies correspond well to tectonic structure of the plate. Still very significant anomalies, showing isostatic disturbances of the lithosphere, are associated with the Zagros fold belt, the collision zone of the Arabian and Eurasian plates.

  14. Idaho Batholith Study Area Isostatic Gravity Grid

    National Oceanic and Atmospheric Administration, Department of Commerce — A 2 kilometer isostatic gravity grid for the Idaho batholith study area. Number of columns is 331 and number of rows is 285. The order of the data is from the lower...

  15. Anchored boundary conditions for locally isostatic networks

    Theran, Louis; Nixon, Anthony; Ross, Elissa; Sadjadi, Mahdi; Servatius, Brigitte; Thorpe, M. F.

    2015-11-01

    Finite pieces of locally isostatic networks have a large number of floppy modes because of missing constraints at the surface. Here we show that by imposing suitable boundary conditions at the surface the network can be rendered effectively isostatic. We refer to these as anchored boundary conditions. An important example is formed by a two-dimensional network of corner sharing triangles, which is the focus of this paper. Another way of rendering such networks isostatic is by adding an external wire along which all unpinned vertices can slide (sliding boundary conditions). This approach also allows for the incorporation of boundaries associated with internal holes and complex sample geometries, which are illustrated with examples. The recent synthesis of bilayers of vitreous silica has provided impetus for this work. Experimental results from the imaging of finite pieces at the atomic level need such boundary conditions, if the observed structure is to be computer refined so that the interior atoms have the perception of being in an infinite isostatic environment.

  16. Uncertainty in Greenland glacial isostatic adjustment

    Milne, G. A.; Lecavalier, B.; Kjeldsen, K. K.; Kjaer, K. H.; Wolstencroft, M.; Wake, L. M.; Ross Simpson, M. J.; Long, A. J.; Woodroffe, S.; Korsgaard, N. J.; Bjork, A. A.; Khan, Shfaqat Abbas

    It is well known that the interpretation of geodetic data in Greenland to constrain recent ice mass changes requires knowledge of isostatic land motion associated with past changes in the ice sheet. In this talk we will consider a variety of factors that limit how well the signal due to past mass...... changes (commonly referred to as glacial isostatic adjustment (GIA)) can be defined. Predictions based on a new model of Greenland GIA will be shown. Using these predictions as a reference, we will consider the influence of plausible variations in some key aspects of both the Earth and ice load components...... periods of the ice history with a focus on the past few thousand years. In particular, we will show predictions of contemporary land motion and gravity changes due to loading changes following the Little Ice Age computed using a new reconstruction of ice thickness changes based largely on empirical data...

  17. 2.5-min Isostatic Gravity Grid for the United States

    National Oceanic and Atmospheric Administration, Department of Commerce — The 2.5-min isostatic gravity data set was produced by regridding the 4-km residual isostatic gravity grid of the U.S. The isostatic residual gravity grid was...

  18. The kinetics of dolomite reaction rim growth under isostatic and non-isostatic pressure conditions

    Helpa, V.; Rybacki, E.; Morales, L. G.; Abart, R.; Dresen, G. H.

    2013-12-01

    During burial and exhumation, rocks are simultaneously exposed to metamorphic reactions and tectonic stresses. Therefore, the reaction rate of newly formed minerals may depend on chemical and mechanical driving forces. Here, we investigate the reaction kinetics of dolomite (CaMg[CO3]2) rim growth by solid-state reactions experiments on oriented calcite (CaCO3) and magnesite (MgCO3) single crystals under isostatic and non-isostatic pressure conditions. Cylindrical samples of 3-5 mm length and 7 mm diameter were drilled and polished perpendicular to the rhombohedral cleavage planes of natural clear crystals. The tests were performed using a Paterson-type deformation apparatus at P = 400 MPa confining pressure, temperatures, T, between 750 and 850°C, and reaction durations, t, of 2 - 146 h to calculate the kinetic parameters of dolomite rim growth under isostatic stress conditions. For non-isostatic reaction experiments we applied in addition differential stresses, σ, up to 40 MPa perpendicular to the contact interface at T = 750°C for 4 - 171 h duration, initiating minor inelastic deformation of calcite. The thickness of the resulting dolomite reaction rims increases linearly with the square root of time, indicating a diffusion-controlled reaction. The rims consist of two different textural domains. Granular dolomite grains (≈ 2 -5 μm grain size) form next to calcite and elongated palisade-shaped grains (1-6 μm diameter) grow perpendicular to the magnesite interface. Texture measurements with the electron backscatter diffraction technique indicate that the orientations of dolomite grains are mainly influenced by the orientation of the calcite educt crystal, in particular in the granular rim. To some extent, the texture of dolomite palisades is also influenced by the orientation of magnesite. The thickness of the two individual layers increases with temperature. At 400 MPa isostatic pressure, T = 750°C and t = 29 hours, a 5 μm thick granular dolomite layer

  19. Glacial isostatic uplift of the European Alps

    Mey, Juergen; Scherler, Dirk; Wickert, Andrew D.; Egholm, David L.; Tesauro, Magdala; Schildgen, Taylor F.; Strecker, Manfred R.

    2016-04-01

    Present-day vertical movements of the Earth's surface are mostly due to tectonic deformation, volcanic processes, and crustal loading/unloading. In tectonically stable regions of North America and Scandinavia, vertical movements are almost entirely attributable to glacial isostatic rebound after the melting of the Laurentide and Fennoscandian ice sheets. In contrast, the Pleistocene Alpine icecap grew on a younger mountain belt that formed by collision of the European and African plates, still subject to shortening. Therefore, measured uplift is potentially a composite signal of tectonic shortening and unloading after deglaciation and concomitant erosion. Deciphering the contributions of tectonics and crustal unloading to present-day uplift rates in formerly-glaciated mountain belts is a prerequisite to using uplift data to estimate the viscosity structure of the Earth's mantle, a key variable in geodynamics. We evaluate the post-LGM glacial-isostatic rebound of the Alps following a 4-tiered procedure. First, we estimated the thickness distribution of sedimentary valley fills to create a bedrock map of the entire mountain belt. Second, this map was used as topographic basis for the reconstruction of the Alpine icecap using a numerical ice-flow model. Third, we estimated the equilibrium deflection of the Alpine lithosphere, using the combined loads of ice and sediments with a variable effective elastic thickness. Finally, we used an exponential decay function to infer the residual deflection and the present-day uplift rate for a range of upper mantle viscosities. Our analysis shows that virtually all of the geodetically measured surface uplift in the Swiss and the Austrian Alps can be attributed to glacial unloading and redistribution of sediments, assuming an upper-mantle viscosity lower than that inferred for an old craton (e.g., Fennoscandia), but higher than that for a region with recent crustal thinning (e.g., Basin and Range province).

  20. Mechanical Properties from PBX 9501 Pressing Study

    Graff Thompson, Darla; Wright, Walter J.

    2004-07-01

    A PBX 9501 pressing study was conducted by researchers in ESA-WMM, LANL, to identify the hydrostatic pressing parameters most important in fabricating high-density parts with uniform density. In this study, 31 charges were pressed using a full permutation of six pressing parameters. Five charges from the set of 31 were selected for an evaluation of their mechanical properties, specifically uniaxial compression and tension. Charges were selected to 1) span the density range of the study, and 2) allow two direct comparisons of pressing parameters independent of bulk density (density has a well-established affect on some material properties). Three PBX 9501 charges pressed isostatically at Pantex Plant in Amarillo, TX were also included in the study. The tensile properties of the 8 charges varied significantly. Careful evaluation of the results suggests that an increase in pressing temperature may correlate with an increase in tensile stress (strength) and a decrease in strain (ductility). Trends in compression exist but are less pronounced. In an effort to explore the relationship between pressing temperature and tensile strength, four sheets of Estane polymer (a component of the PBX 9501 binder) were compression molded at 70, 90, 110 and 130°C. The tensile strength of Estane was observed to increase by a factor of nearly 20 when the molding temperature was increased from 70 to 90°C (strength increase was negligible beyond 90°C). We present an outline of ongoing work that will irrefutably quantify the mechanical property affects of both pressing temperature and dwell time on PBX 9501.(LA-UR 03-4842).

  1. La presse

    Bret, Patrice; Chappey, Jean-Luc; Conforti, Maria; Kury, Lorelai; Laboulais, Isabelle; Lacour, Pierre-Yves; Marcil, Yasmine; Martin, Virginie; Weiss, Clément

    2012-01-01

    Organisée en novembre 2009 par l’Institut d’histoire de la Révolution française (Université de Paris I / Ea 127) en collaboration avec le Centre de recherche en histoire des sciences et des techniques (Centre Alexandre Koyré / CNRS-EHESS-MNHN / UMR 8560) et le département CIM Communication Information Médias / Ea 1484 (Université de Paris III), la rencontre sur les usages de l’encyclopédisme dans la presse savante autour de la Révolution française marque une nouvelle étape dans une réflexion ...

  2. Isostatic residual gravity anomaly data grid for the conterminous US

    U.S. Geological Survey, Department of the Interior — The grid of isostatic residual gravity anomaly data was produced from the grid of Bouguer gravity anomaly data (see Bouguer gravity metadata) by using an...

  3. Numerical simulation of Glacial Isostatic Adjustment

    Miglio, E.

    2015-12-01

    In the Earth's crust, stress can be subdivided into tectonic background stress, overburden pressure, and pore-fluid pressure. The superposition of the first two and the variation of the third part are key factors in controlling movement along faults. Furthermore, stresses due to sedimentation and erosion contribute to the total stress field. In deglaciated regions, an additional stress must be considered: the rebound stress, which is related to rebounding of the crust and mantle after deglaciation. During the growth of a continental ice sheet, the lithosphere under the iceload is deformed and the removal of the ice load during deglaciation initiates a rebound process. The uplift is well known in formerly glaciated areas, e.g.North America and Scandinavia, and in currently deglaciating areas, e.g.Alaska, Antarctica, and Greenland. The whole process of subsiding and uplifting during the growth and melting of an iceload and all related phenomena is known as glacial isostatic adjustment. During the process of glaciation, the surface of the lithosphere is depressed underneath the ice load and compressional flexural stresses are induced in the upper lithosphere, whereas the bottom of the lithosphere experiences extensional flexural stresses; an additional vertical stress due to the ice load is present and it decreases to zero during deglaciation. During rebound, flexural stresses relax slowly. These stresses are able to change the original stress directions and regime.In this work we aim to study the effect of the GIA process in the context of petroleum engineering. The main aspect we will focus on is the mathematical and numerical modeling of the GIA including thermal effects. We plan also to include a preliminary study of the effect of the glacial erosion. All these phenomena are of paramount importance in petroleum engineering: for example some reservoir have been depleted due to tilting caused by both GIA, erosion and thermal effects.

  4. Press Start

    Harteveld, Casper

    This level sets the stage for the design philosophy called “Triadic Game Design” (TGD). This design philosophy can be summarized with the following sentence: it takes two to tango, but it takes three to design a meaningful game or a game with a purpose. Before the philosophy is further explained, this level will first delve into what is meant by a meaningful game or a game with a purpose. Many terms and definitions have seen the light and in this book I will specifically orient at digital games that aim to have an effect beyond the context of the game itself. Subsequently, a historical overview is given of the usage of games with a serious purpose which starts from the moment we human beings started to walk on our feet till our contemporary society. It turns out that we have been using games for all kinds of non-entertainment purposes for already quite a long time. With this introductory material in the back of our minds, I will explain the concept of TGD by means of a puzzle. After that, the protagonist of this book, the game Levee Patroller, is introduced. Based on the development of this game, the idea of TGD, which stresses to balance three different worlds, the worlds of Reality, Meaning, and Play, came into being. Interested? Then I suggest to quickly “press start!”

  5. Micrometer size grains of hot isostatically pressed alumina and its characterization

    A K Mallik; S Gangadharan; S Dutta; D Basu

    2010-08-01

    Alumina samples were prepared from two different particle size powders. Finer particle compacts when heated along with coarser particle compacts at same processing temperatures produce bigger grain microstructures due to higher grain growth. An unconventional method of etching by molten V2O5 was adopted to look at the microstructure for accuracy in reported data. On an average starting with finer particles give microstructure with a grain size of 5.5 m and starting with coarser particles, give microstructure with 2.2 m average grain size. The flexural strength is around 400 MPa for alumina samples prepared from finer powder in comparison with about 550 MPa for alumina samples prepared from coarser powder. The Vickers hardness in 5.5 m grain microstructure is around 20 GPa in comparison to about 18 GPa in microstructure with smaller grains of 2.2 m size.

  6. Kinetics and mechanisms of creep in hot isostatically pressed niobium carbide

    Constant compressive stress creep experiments in the temperature and stress ranges of 1730K - 2100K and 16 MN/m2 - 70 MM/m2 on HIPed NbC0.74 have revealed stress exponents of 2.0 under stress levels of 16-54 MN/m2 at all temperatures investigated and 3.2 under stress levels of 54-70 MN/m2 at 1830K. The activation energy of steady state creep is approximately 230 kJ/mol in the temperature range of 1730K - 1930K under 48-54 MN/m2 and 470 kJ/mol in the temperature range of 1900K - 2100K under 64 MN/m2. TEM of the annealed but uncrept material reveals grown-in dislocation subboundaries. At 1730K and under 34-54 MN/m2, these subboundaries become single dislocations and dipoles. At 1830K and under 54-70 MN/m2 the subboundaries evolve into simple tilt boundaries which are occasionally knitted, indicating more glide activity at higher stresses. At 1930K and under 34-54 MN/m2, hexagonal subboundaries form, but are not as well defined as in the annealed material. At 2100K and under 16-30 MN/m2, the subboundaries are well-defined hexagonal networks which become polygonized under higher stresses on 64 MN/m2. The experimental and TEM results indicate that at low temperatures (below 0.5 Tm = 2073K) and at all stresses, creep occurs by dislocation glide which is accompanied by subgrain and high angle boundary interaction. At high temperature (above 0.5 Tm), strain occurs by glide and subboundary movement; recovery occurs by climb in the subboundary

  7. Structural behaviour of monolithic fuel plates during hot isostatic pressing and annealing

    This article presents thermo-mechanical analysis of the monolithic fuel plates and their structural behavior during fabrication and thermal annealing performed by commercial FE solver COMSOL Multiphysics. The detailed 3D non-linear FEM analysis of the monolithic fuel plates has been useful not only for benchmarking the new model, but also for obtaining an in-depth understanding of fuel-cladding stress/strain characteristics. In particular, the 3D FEM analysis has revealed existence of stress gradients at the fuel/cladding interface region which could lead to structural failure. Large difference in the coefficient of thermal expansions between the U-10Mo foil and AL6061-TO cladding is the main reason for these gradients. During the thermal transient, thermo-mechanical behavior of the plate is driven by the significant mismatch between thermal expansion and basic mechanical properties of the foil and the cladding materials. By using elasto-thermo-perfectly plastic material models, it was shown that cladding material exceeds its yield limit; and therefore, deforms plastically; while the fuel foil remains below its elastic limit. In addition, it was observed that fabrication-induced residual stresses play major role in overall performance of monolithic fuel plates. The simulation results show existence of the critical temperature at which the normal and shear components of stresses change from compressive to tensile on both cladding and fuel. Furthermore, thermo-mechanical analysis of dispersion fuel mini-plates was presented. In order to properly identify three dimensional stress states over the dispersion particles and cladding material, micro-structure based finite element simulation was performed. It was shown that residual stresses in dispersion fuels cannot be neglected and should be included in proceeding simulations. (author)

  8. Professional WordPress

    Stern, Hal; Williams, Brad

    2010-01-01

    An in-depth look at the internals of the WordPress system.As the most popular blogging and content management platform available today, WordPress is a powerful tool. This exciting book goes beyond the basics and delves into the heart of the WordPress system, offering overviews of the functional aspects of WordPress as well as plug-in and theme development. What is covered in this book?: WordPress as a Content Management System; Hosting Options; Installing WordPress Files; Database Configuration; Dashboard Widgets; Customizing the Dashboard; Creating and Managing Content; Categorizing Your Cont

  9. News/Press Releases

    Office of Personnel Management — A press release, news release, media release, press statement is written communication directed at members of the news media for the purpose of announcing programs...

  10. Supersymmetry "protected" topological phases of isostatic lattices and kagome antiferromagnets

    Lawler, Michael J

    2015-01-01

    I generalize the theory of phonon topological band structures of isostatic lattices to frustrated antiferromagnets. I achieve this with a discovery of a many-body supersymmetry (SUSY) in the phonon problem of balls and springs and its connection to local constraints satisfied by ground states. The Witten index of the SUSY model demands the Maxwell-Calladine index of mechanical structures. "Spontaneous supersymmetry breaking" is identified as the need to gap all modes in the bulk to create the...

  11. The complex isostatic equilibration of Australia's deep crust.

    Aitken, Alan; Gross, Lutz; Altinay, Cihan

    2016-04-01

    A recent study, using a new finite-element based gravity inversion method has modelled in high-resolution the density and pressure fields for the Australian continent. Here we analyse the pressure results to consider how Australia's lower-crust and Moho contribute to the isostatic equilibration of topography and crustal masses. We find that the situation is more complex than the commonly applied model of isostatic compensation through crustal thickness variations. Key differences include low pressure-variability at ca. 30-35 km, suggesting that the thickness of the felsic-intermediate crust equilibrates most of the upper-crustal loads; increasing pressure-variability between 30-50 km, suggesting that positively buoyant deep-crustal roots generate disequilibrium. These large roots have previously been inferred to represent mafic underplates. Pressure-variability in the uppermost lithospheric mantle reduces to a minimum at ~125 km depth, suggesting that these loads are compensated by dense mantle at ~100 km depth, rather than by crustal loads or topography. This raises the notion that Australia's lithosphere is isostatically compensated at two levels: Crustal compensation involving topography and the felsic to intermediate crust; and deep-lithosphere compensation involving the mafic lower crust and lithospheric mantle. Rather than its traditional role of compensating for crustal masses, the Moho in this case appears to be a source of isostatic disequilibrium, acting in a separate cell with lithospheric mantle density sources. These results imply that, for cratonised continents like Australia, the notion of crustal isostasy is a poor descriptor of the system.

  12. The Global University Press

    Dougherty, Peter J.

    2012-01-01

    The modern world's understanding of American university press has long been shaped by university-press books. American university-press books are good international advertisements for the universities whose logos grace their spines. The growth of transnational scholarship and the expansion of digital communications networks are converging in ways…

  13. Growth of yttrium orthovanadate by LHPG in isostatic oxygen atmosphere

    Reyes Ardila, D.; de Camargo, A. S. S.; Andreeta, J. P.; Nunes, L. A. O.

    2001-11-01

    The growth of undoped and Nd 3+-doped YVO 4 crystals in isostatic oxygen atmosphere by the laser-heated pedestal growth technique was investigated. Absorption, photoluminescence, X-ray powder diffraction and Raman shift spectra were used to characterize the grown crystals. Differences in Y-V and oxygen stoichiometries were identified and discussed in terms of the starting materials processing, crystal growth dynamics and post-growth thermal treatment. The experimental results indicate that single crystal fibers with general optical and spectroscopic properties close to those of the best respective available bulk single crystals were grown.

  14. Afterpulse measurement for 8-inch candidate PMTs for LHAASO

    Zhao, X.; Tang, Z.; Li, C.; Chen, H.; Zhang, Y.; Li, X.; Shao, M.; Sun, Y.; Zha, W.; Zhou, Y.

    2016-05-01

    An afterpulse occurs within a short time after the main pulse and cannot be directly distinguished from the true physical signals. In cosmic ray experiments, a large number of photomultiplier tubes (PMTs) are used, which means the occurrence of afterpulses leads to a significant background. Therefore, before PMTs are employed, their afterpulse characteristics need to be evaluated to make sure they perform as expected. To evaluate the impact of afterpulses, we investigate the afterpulses for the Hamamatsu PMT R5912 (a candidate of the WCDA and MD for LHAASO) using two different electronic testing systems. First, we measured the characteristics of afterpulses in detail using a frequency-tunable flash analog-to-digital converter (ADC) with a time window of up to 15 μ s after a laser signal. We measured the time delay with respect to the main pulse, the amplitude, and the rate of the afterpulse dependence, on the main signal amplitude and the applied high voltage. Second, we developed a system that uses a multi-hit time-to-digital converter (multi-hit TDC), which allows for much faster measurement of the afterpulse rates, in order to make it possible to test up to 5000 large-sized PMTs.

  15. Isostatic compaction of beaker shaped bentonite blocks on the scale 1:4

    Johannesson, Lars-Erik [Clay Technology AB, Lund (Sweden); Nord, Sven [Ifoe Ceramics AB, Bromoella (Sweden ); Pusch, Roland [Geodevelopment AB, Lund (Sweden); Sjoeblom, Rolf [AaF-Energikonsult AB, Stockholm (Sweden)

    2000-09-01

    The purpose of the present work is to test, on a scale of 1:4, the feasibility of manufacturing bentonite blocks by isostatic compaction for application as a buffer material in a repository for spent nuclear fuel. In order for the tests to be sensitive to any weaknesses of the method, the blocks were shaped as beakers. The scope included the following: 1. Preparation of powder: a. mixing of the bentonite and addition of water in predetermined amounts, b. sieving to remove any lumps generated; 2. Isostatic compaction: a. establishment of a separate laboratory for the handling of bentonite powder (weighing, mixing, filling, sampling and machining), b. development and design of equipment and procedures for compaction of bentonite to beaker-shaped specimens, c. compaction process operation, d. visual inspection; 3. Sampling and characterisation: a. extraction of samples from the blocks made, b. determination of water content, c. determination of density, d. determination of strain at maximum stress by means of bending tests, e. determination of tensile strength by means of bending tests, f. determination of geometries of the blocks prepared; 4. Post-treatment by means of machining: a. machining of blocks made, b. visual inspection; 5. Evaluation. The work went very smoothly. No significant obstacles or unexpected events were encountered. The conclusions are as follows: The conclusions drawn in this report from work on the (linear)scale of one to four are very relevant to the full scale. Mixing of bentonite powder as well as moistening can be carried out on a pilot scale with a good homogeneity and with maintained good quality of the press powder. The compaction of bentonite can be carried out in a similar manner to the present operation at Ifoe Ceramics AB. This implies a very efficient handling as well as a very efficient use of the time in the press which may account for a large proportion of the total cost. The blocks could readily be produced to reproducible

  16. WordPress Bible

    Brazell, Aaron

    2011-01-01

    Get the latest word on the biggest self-hosted blogging tool on the marketWithin a week of the announcement of WordPress 3.0, it had been downloaded over a million times. Now you can get on the bandwagon of this popular open-source blogging tool with WordPress Bible, 2nd Edition. Whether you're a casual blogger or programming pro, this comprehensive guide covers the latest version of WordPress, from the basics through advanced application development. If you want to thoroughly learn WordPress, this is the book you need to succeed.Explores the principles of blogging, marketing, and social media

  17. Design and analysis of isostatic mounts on a spaceborne lightweight primary mirror

    Chan, C. Y.; Chen, Y. C.; Chang, S. T.; Huang, T. M.; Hsu, M. Y.

    2013-09-01

    The paper is aimed at obtaining the optimum isostatic mount configuration for a ZERODUR® primary mirror with a predesigned lightweight configuration on the back for a space Cassegrain telescope. The finite element analysis and Zernike polynomial fitting based on the Taguchi method are applied to the whole optimization process. Under the integrated optomechanical analysis, three isostatic mounts are bonded to the center of gravity of the mirror. Geometrical control factors and levels have been selected to minimize the optical aberrations under self-weight loading. The optimum isostatic mount with the least induced astigmatism value is finally attained under the Taguchi method.

  18. Glacial Isostatic Adjustment - a hot topic in cold regions

    Whitehouse, Pippa

    2016-04-01

    Glacial Isostatic Adjustment (GIA) modelling tackles the classic geodynamical problem of determining the solid Earth response to surface load changes by ice and ocean water whilst at the same time solving for the gravitationally-consistent redistribution of ice sheet meltwater across the global ocean. Understanding this process is important for quantifying both present-day ice mass balance and the response of ice sheets to past and future climatic change. The two fundamental unknowns in this problem are (i) the rheology of the solid Earth, and (ii) the history of global ice sheet change. In this talk I will discuss the myriad of approaches that are used to constrain these two components. In particular, I will focus on Antarctica, where the presence of a continuously-evolving ice sheet, situated on top of one of the most rheologically-diverse regions of the planet, provides us with a challenge that can only be resolved by drawing on knowledge from across the fields of geodynamics, glaciology, geology, geodesy and seismology.

  19. Do crustal deformations observed by GPS in Tierra del Fuego (Argentina) reflect glacial-isostatic adjustment?

    Mendoza, L.; A. Richter; Hormaechea, J. L.; Perdomo, R.; Cogliano, D.; R. Dietrich; Fritsche, M.

    2010-01-01

    Vertical site velocities determined by geodetic GPS observations in the Lago Fagnano area, Tierra del Fuego main island, are interpreted with respect to their potential relation with the glacial-isostatic crustal response to ice mass changes. The spatial pattern of the uplift rates, in combination with the horizontal crustal deformation pattern, point towards a fault-tectonic rather than glacial-isostatic origin of the determined vertical crustal deformations. This implies rather small GIA ef...

  20. Microstructural anomalies in hot-isostatic pressed U—10wt.% Mo fuel plates with Zr diffusion barrier

    Microstructural anomalies in the co-rolled-and-HIP'ed U—10 wt.% Mo (U10Mo) metallic fuel plate with Zr diffusion barrier assembly were examined as a function of HIP temperature (from 520 to 580 °C) and duration (45, 60, 90, 180 and 345 min) by scanning and transmission electron microscopy. The anomalies observed in this study are carbide/oxide inclusions within the U10Mo fuel alloy, and regions of limited interaction between the U10Mo alloy and Zr barrier, frequently associated with carbide/oxide inclusions. In the U10Mo alloy, the cF8, Fm3m (225) UC phase (a=4.955 Å) and cF12, Fm3m (225) UO2 phase (a=5.467 Å) were observed throughout the U10Mo alloy with an approximate volume percent of 0.5 to 1.8. The volume percent of the UC—UO2 inclusions within the U10Mo alloy did not change as functions of HIP temperature and time. These inclusion phases, located near the surface of the U10Mo alloy, were frequently observed to impede the development of interdiffusion and reaction between the U10Mo alloy and Zr diffusion barrier. The regions of limited interaction between the U10Mo and Zr barrier decreased with an increase in HIP temperature, however no noticeable trend was observed with an increase in HIP duration at constant temperature of 560 °C.

  1. La{sub 2}O{sub 3}-reinforced W and W-V alloys produced by hot isostatic pressing

    Munoz, A., E-mail: angel.munoz@uc3m.es [Departamento de Fisica, Universidad Carlos III de Madrid, 28911 Leganes (Spain); Monge, M.A., E-mail: mmonge@fis.uc3m.es [Departamento de Fisica, Universidad Carlos III de Madrid, 28911 Leganes (Spain); Savoini, B., E-mail: bsavoi@fis.uc3m.es [Departamento de Fisica, Universidad Carlos III de Madrid, 28911 Leganes (Spain); Rabanal, M.E., E-mail: eugenia@ing.uc3m.es [Departamento de Ciencia e Ingenieria de Materiales e Ingenieria Quimica, Universidad Carlos III de Madrid, 28911 Leganes (Spain); Garces, G., E-mail: ggarces@cenim.csic.es [Centro Nacional de Investigaciones Melaturgicas, CENIM, 28040 Madrid (Spain); Pareja, R., E-mail: rpp@fis.uc3m.es [Departamento de Fisica, Universidad Carlos III de Madrid, 28911 Leganes (Spain)

    2011-10-01

    W and W-V alloys reinforced with La{sub 2}O{sub 3} particles have been produced by MA and subsequent HIP at 1573 K and 195 MPa. The microstructure of the consolidated alloys has been characterized by scanning electron microscopy, energy dispersive spectroscopy analyses and X-ray diffraction. The mechanical properties were studied by nanoindentation measurements. The results show that practically full dense billets of W-V, W-V-La{sub 2}O{sub 3} and W-La{sub 2}O{sub 3} alloys can be produced. The microstructure analysis has shown that islands of V are present in W-V and W-V-1La{sub 2}O{sub 3} alloys. In W-1La{sub 2}O{sub 3} islands of La{sub 2}O{sub 3} are also present. The nanohardness of the W matrix increases with the addition of V, while decreases with the addition of La{sub 2}O{sub 3}.

  2. Prediction of maximum casting defect size in MAR-M-247 alloy processed by hot isostatic pressing

    Šmíd, Miroslav; Fintová, Stanislava; Kunz, Ludvík; Hutař, Pavel; Hrbáček, K.

    2015-01-01

    Roč. 22, č. 1 (2015), s. 25-32. ISSN 1335-0803 R&D Projects: GA MPO FR-TI4/030; GA MŠk(CZ) EE2.3.20.0214 Institutional support: RVO:68081723 Keywords : MAR-M 247 * Superalloys * Fatigue * Casting defects * Elevated temperatures Subject RIV: JL - Materials Fatigue, Friction Mechanics http://ojs.mateng.sk/index.php/Mateng/article/view/160/249

  3. bbPress complete

    Wynne, Rhys

    2013-01-01

    A concise guide, written in an easy-to-follow format.This book is aimed at ambitious website or blog owners looking to add a forum to their site quickly and easily. Basic experience in WordPress and with managing a website is expected. Knowledge of HTML and PHP will be a bonus, though it isn't necessary.

  4. PREMIER MEETS THE PRESS

    2010-01-01

    On March 14, Premier Wen Jiabao addressed the Chinese and foreign media at a press conference after the closing meeting of the Third Session of the 11th National People’s Congress. Edited highlights on a number of economic and social issues follow:

  5. PREMIER MEETS THE PRESS

    2010-01-01

    @@ March 14.Premier Wen Jiabao addressed the Chinese and foreign media at a press conference after the closing meeting of the Third Session of the 1 lth National People's Congress.Edited highlights on a number of economic and social issues follow:

  6. Press-On Optics

    Thorson, Jon C.

    1972-01-01

    The article discusses the design, application, and clinical uses of press-on optics which are descirbed as 1 millimeter thick, flexible lenses or prisms that may be produced in virtually any desired plus or minus dioptric power as ophthalmic lenses, or in any range of usable prism diopter power. (GW)

  7. Worldwide complete spherical Bouguer and isostatic anomaly maps

    Bonvalot, S.; Balmino, G.; Briais, A.; Peyrefitte, A.; Vales, N.; Biancale, R.; Gabalda, G.; Reinquin, F.

    2011-12-01

    We present here a set of digital maps of the Earth's gravity anomalies (surface "free air", Bouguer and isostatic), computed at Bureau Gravimetric International (BGI) as a contribution to the Global Geodetic Observing Systems (GGOS) and to the global geophysical maps published by the Commission for the Geological Map of the World (CGMW). The free air and Bouguer anomaly concept is extensively used in geophysical interpretation to investigate the density distributions in the Earth's interior. Complete Bouguer anomalies (including terrain effects) are usually computed at regional scales by integrating the gravity attraction of topography elements over and beyond a given area (under planar or spherical approximations). Here, we developed and applied a worldwide spherical approach aimed to provide a set of homogeneous and high resolution gravity anomaly maps and grids computed at the Earth's surface, taking into account a realistic Earth model and reconciling geophysical and geodetic definitions of gravity anomalies. This first version (1.0) has been computed by spherical harmonics analysis / synthesis of the Earth's topography-bathymetry up to degree 10800. The detailed theory of the spherical harmonics approach is given in Balmino et al., (Journal of Geodesy, submitted). The Bouguer and terrain corrections have thus been computed in spherical geometry at 1'x1' resolution using the ETOPO1 topography/bathymetry, ice surface and bedrock models from the NOAA (National Oceanic and Atmospheric Administration) and taking into account precise characteristics (boundaries and densities) of major lakes, inner seas, polar caps and of land areas below sea level. Isostatic corrections have been computed according to the Airy Heiskanen model in spherical geometry for a constant depth of compensation of 30km. The gravity information given here is provided by the Earth Geopotential Model (EGM2008), developed at degree 2160 by the National Geospatial Intelligence Agency (NGA) (Pavlis

  8. A benchmark study for glacial isostatic adjustment codes

    Spada, G.; Barletta, V. R.; Klemann, V.; Riva, R. E. M.; Martinec, Z.; Gasperini, P.; Lund, B.; Wolf, D.; Vermeersen, L. L. A.; King, M. A.

    2011-04-01

    The study of glacial isostatic adjustment (GIA) is gaining an increasingly important role within the geophysical community. Understanding the response of the Earth to loading is crucial in various contexts, ranging from the interpretation of modern satellite geodetic measurements (e.g. GRACE and GOCE) to the projections of future sea level trends in response to climate change. Modern modelling approaches to GIA are based on various techniques that range from purely analytical formulations to fully numerical methods. Despite various teams independently investigating GIA, we do not have a suitably large set of agreed numerical results through which the methods may be validated; a community benchmark data set would clearly be valuable. Following the example of the mantle convection community, here we present, for the first time, the results of a benchmark study of codes designed to model GIA. This has taken place within a collaboration facilitated through European Cooperation in Science and Technology (COST) Action ES0701. The approaches benchmarked are based on significantly different codes and different techniques. The test computations are based on models with spherical symmetry and Maxwell rheology and include inputs from different methods and solution techniques: viscoelastic normal modes, spectral-finite elements and finite elements. The tests involve the loading and tidal Love numbers and their relaxation spectra, the deformation and gravity variations driven by surface loads characterized by simple geometry and time history and the rotational fluctuations in response to glacial unloading. In spite of the significant differences in the numerical methods employed, the test computations show a satisfactory agreement between the results provided by the participants.

  9. ISS Expedition 40 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 40 from 03/2014-11/2014. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  10. ISS Expedition 01 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 01 from 10/2000-03/2001. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  11. ISS Expedition 33 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 33 from 07/2012-11/2012. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  12. ISS Expedition 32 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 32 from 05/2012-09/2012. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  13. ISS Expedition 06 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 06 from 11/2002-05/2003. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  14. ISS Expedition 23 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 23 from 12/2009-09/2010. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  15. ISS Expedition 37 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 37 from 05/2013-11/2013. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  16. ISS Expedition 28 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 28 from 04/2011-11/2011. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  17. ISS Expedition 17 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 17 from 04/2008-10/2008. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  18. ISS Expedition 07 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 07 from 04/2003-10/2003. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  19. ISS Expedition 13 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 13 from 03/2006-09/2006. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  20. ISS Expedition 19 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 19 from 03/2009-05/2009. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  1. ISS Expedition 14 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 14 from 09/2006-04/2007. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  2. ISS Expedition 39 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 39 from 11/2013-05/2014. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  3. ISS Expedition 16 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 16 from 10/2007-04/2008. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  4. ISS Expedition 34 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 34 from 12/2012-03/2013. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  5. ISS Expedition 35 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 35 from 03/2013-09/2013. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  6. ISS Expedition 02 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 02 from 03/2001-08/2001. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  7. ISS Expedition 09 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 09 from 04/2004-10/2004. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  8. ISS Expedition 41 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 41 from 05/2014-11/2014. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  9. ISS Expedition 31 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 31 from 12/2011-07/2012. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  10. ISS Expedition 25 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 25 from 06/2010-03/2011. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  11. ISS Expedition 26 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 26 from 10/2010-05/2011. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  12. ISS Expedition 05 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 05 from 06/2002-12/2002. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  13. ISS Expedition 20 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 20 from 05/2009-10/2009. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  14. ISS Expedition 11 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 11 from 04/2005-10/2005. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  15. ISS Expedition 36 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 36 from 03/2013-09/2013. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  16. ISS Expedition 18 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 18 from 10/2008-04/2009. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  17. ISS Expedition 10 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 10 from 10/2004-04/2005. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  18. ISS Expedition 30 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 30 from 11/2011-07/2012. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  19. ISS Expedition 12 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 12 from 10/2005-04/2006. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  20. ISS Expedition 24 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 24 from 04/2010-11/2010. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  1. ISS Expedition 27 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 27 from 12/2010-09/2011. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  2. ISS Expedition 04 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 04 from 12/2001-06/2002. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  3. ISS Expedition 15 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 15 from 04/2007-10/2007. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  4. ISS Expedition 38 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 38 from 09/2013-03/2014. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  5. ISS Expedition 03 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 03 from 08/2001-12/2001. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  6. ISS Expedition 08 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 08 from 10/2003-04/2004. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  7. ISS Expedition 42 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 42 from 09/2014-03/2015. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  8. ISS Expedition 43 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 43 from 11/2014-06/2015. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  9. The alignment and isostatic mount bonding technique of the aerospace Cassegrain telescope primary mirror

    Lin, Wei Cheng; Chang, Shenq-Tsong; Lin, Yu-Chuan; Hsu, Ming-Ying; Chang, Yu-Ting; Chang, Sheng-Hsiung; Huang, Ting-Ming

    2012-10-01

    In order to meet both optical performance and structural stiffness requirements of the aerospace Cassegrain telescope, iso-static mount is used as the interface between the primary mirror and the main plate. This article describes the alignment and iso-static mount bonding technique of the primary mirror by assistance of CMM. The design and assembly of mechanical ground support equipment (MGSE) which reduces the deformation of primary mirror by the gravity effect is also presented. The primary mirror adjusting MGSE consists of X-Y linear translation stages, rotation stage and kinematic constrain platform which provides the function of decenter, orientation, tilt and height adjustment of the posture sequentially. After CMM measurement, the radius of curvature, conic constant, decenter and tilt, etc. will be calculated. According to these results, the posture of the mirror will be adjusted to reduce the tilt by the designed MGSE within 0.02 degrees and the distance deviation from the best fitted profile of mirror to main plate shall be less than 0.01 mm. After that, EC 2216 adhesive is used to bond mirror and iso-static mount. During iso-static mount bonding process, CMM is selected to monitor the relative position deviation of the iso-static mount until the adhesive completely cured. After that, the wave front sensors and strain gauges are used to monitor the strain variation while the iso-static mount mounted in the main plate with the screws by the torque wrench. This step is to prevent deformation of the mirror caused from force of the iso-static mount during the mounting process. In the end, the interferometer is used for the optical performance test with +1G and -1G to check the alignment and bonding technique is well or not.

  10. WordPress multisite administration

    Longren, Tyler

    2013-01-01

    This is a simple, concise guide with a step-by-step approach, packed with screenshots and examples to set up and manage a network blog using WordPress.WordPress Multisite Administration is ideal for anyone wanting to familiarize themselves with WordPress Multisite. You'll need to know the basics about WordPress, and having at least a broad understanding of HTML, CSS, and PHP will help, but isn't required.

  11. Which Freedom of the Press?

    Rytter, Jens Elo

    2010-01-01

     privileged freedom of the organised press to gather and report on information of public interest. These two conceptions have very different answers to the question of whether the press should enjoy some privilege to be exempt from ordinary legislation when such legislation restricts the access of the press to inform...

  12. WordPress for dummies

    Sabin-Wilson, Lisa

    2014-01-01

    The bestselling WordPress guide, fully updated to cover the 2013 enhancements WordPress has millions of users, and this popular guide has sold more than 105,000 copies in its previous editions. With the newest releases of WordPress, author and WordPress expert Lisa Sabin-Wilson has completely updated the book to help you use and understand all the latest features. You'll learn about both the hosted WordPress.com version and the more flexible WordPress.org, which requires third-party hosting. Whether you're switching to WordPress from another blogging platform or just beginning to blog, you'll

  13. Hot pressing aluminum nitride

    Experiment was performed on the hot pressing of aluminum nitride, using three kinds of powder which are: a) made by electric arc method, b) made by nitrifying aluminum metal powder, and c) made from alumina and carbon in nitrogen atmosphere. The content of oxygen of these powders was analyzed by activation analysis using high energy neutron irradiation. The density of hot pressed samples was classified into two groups. The high density group contained oxygen more than 3 wt. %, and the low density group contained about 0.5 wt %. Typical density vs. temperature curves have a bending point near 1,5500C, and the sample contains iron impurity of 0.5 wt. %. Needle crystals were found to grow near 1,5500C by VLS mechanism, and molten iron acts a main part of mechanism as a liquid phase. According to the above-mentioned curve, the iron impurity in aluminum nitride prevents densification. The iron impurity accelerates crystal growth. Advance of densification may be expected by adding iron impurity, but in real case, the densification is delayed. Densification and crystal growth are greatly accelerated by oxygen impurity. In conclusion, more efforts must be made for the purification of aluminum nitride. In the present stage, the most pure nitride powder contains about 0.1 wt. % of oxygen, as compared with good silicon carbide crystals containing only 10-5 wt. % of nitrogen. (Iwakiri, K.)

  14. Do crustal deformations observed by GPS in Tierra del Fuego (Argentina) reflect glacial-isostatic adjustment?

    Mendoza, L.; Richter, A.; Hormaechea, J. L.; Perdomo, R.; Del Cogliano, D.; Dietrich, R.; Fritsche, M.

    2010-09-01

    Vertical site velocities determined by geodetic GPS observations in the Lago Fagnano area, Tierra del Fuego main island, are interpreted with respect to their potential relation with the glacial-isostatic crustal response to ice mass changes. The spatial pattern of the uplift rates, in combination with the horizontal crustal deformation pattern, point towards a fault-tectonic rather than glacial-isostatic origin of the determined vertical crustal deformations. This implies rather small GIA effects pointing towards relatively small Holocene ice-mass changes in Tierra del Fuego. However, these findings are considered to be preliminary. They should be confirmed by additional observations covering an extended area with GPS sites.

  15. Variations in Crustal Structure, Lithospheric Flexural Strength, and Isostatic Compensation Mechanisms of Mars

    Ding, M.; Lin, J.; Zuber, M. T.

    2014-12-01

    We analyze gravity and topography of Mars to investigate the spatial variations in crustal thickness, lithospheric strength, and mechanisms of support of prominent topographic features on Mars. The latest gravity model JGMRO110c (released in 2012) from the Mars Reconnaissance Orbiter mission has a spatial block size resolution of ~97 km (corresponding to degree-110), enabling us to resolve crustal structures at higher spatial resolution than those determined from previous degree-80 and 85 gravity models [Zuber et al., 2000; McGovern et al., 2002, 2004; Neumann et al., 2004; Belleguic et al., 2005]. Using the latest gravity data, we first inverted for a new version of crustal thickness model of Mars assuming homogeneous crust and mantle densities of 2.9 and 3.5 g/cm3. We calculated "isostatic" topography for the Airy local isostatic compensation mechanism, and "non-isostatic" topography after removing the isostatic part. We find that about 92% of the Martian surface is in relatively isostatic state, indicating either relatively small lithospheric strength and/or small vertical loading. Relatively isostatic regions include the hemispheric dichotomy, Hellas and Argyre Planitia, Noachis and Arabia Terra, and Terra Cimmeria. In contrast, regions with significant amount of non-isostatic topography include the Olympus, Ascraeus, Arsia, Pavonis, Alba, and Elysium Mons, Isidis Planitia and Valles Marineris. Their relatively large "non-isostatc topography" implies relatively strong lithospheric strength and large vertical loading. Spectral analysis of the admittance and correlation relationship between gravity and topography were conducted for the non-isostatic regions using the localized spectra method [Wieczorek and Simons, 2005, 2007] and thin-shell lithospheric flexural approximation [Forsyth, 1985; McGovern et al., 2002, 2004]. The best-fitting models reveal significant variations in the effective lithospheric thickness with the greatest values for the Olympus Mon

  16. Australia's lithospheric density field, and its isostatic equilibration

    Aitken, A. R. A.; Altinay, C.; Gross, L.

    2015-12-01

    subdivisions within each. The lithospheric static pressure field was resolved in 3D from the gravity and density fields. The pressure field model also highlights the fundamental difference between the oceanic and continental domains, with the former possessing lower pressure through most of the model. Overall pressure variability is large in the upper crust (60 MPa) but reduces significantly by -30 km elevation (20-30 MPa). By -50 km elevation, thick lower-crust generates further disequilibria (25-35 MPa) that are not compensated until -125 km elevation (10-20 MPa). Beneath -125 km elevation higher pressure is observed in the continental domain, extending to the base of the model. This indicates a lithosphere that is to a large degree isostatically compensated near the base of the felsic-intermediate continental crust, and again near the theoretical base of mature oceanic lithosphere.

  17. Absolute sea levels and isostatic changes of the eastern North Sea to central Baltic region during the last 900 years

    Hansen, Jens Morten; Aagaard, Troels; Binderup, Merete

    2012-01-01

    confirms that ice-cap growth can be faster than ice-cap melting. By comparison with 29 long-term tide gauge measurements of the region we show that the isostatic implications of the sea-level curve are in nearly perfect agreement with Peltier's global isostatic VM2 model (applied by IPCC and PSMSL) and...

  18. WordPress For Dummies

    Sabin-Wilson, Lisa

    2011-01-01

    The bestselling guide to WordPress, fully updated to help you get your blog going! Millions of bloggers rely on WordPress, the popular, free blogging platform. This guide covers all the features and improvements in the most up-to-date version of WordPress. Whether you are switching to WordPress from another blogging platform or just starting your first blog, you'll find the advice in this friendly guide gets you up to speed on both the free-hosted WordPress.com version and WordPress.org, which requires the purchase of web hosting services, and figure out which version is best for you. You'll b

  19. Separation of dynamic and isostatic components of the Venusian gravity and topography and determination of the crustal thickness of Venus

    Yang, An; Huang, Jinshui; Wei, Daiyun

    2016-09-01

    Assuming that the long-wavelength geoid and topography of Venus are supported by both mantle convection and Airy isostasy, we propose a method to separate the dynamic and isostatic components of the Venusian gravity and topography with the aid of the dynamic admittance from numerical models of mantle convection and the isostatic admittance from an Airy isostatic model. The global crustal thickness is then calculated based on the isostatic component of the gravity and topography. The results show that some highland plateaus such as Ishtar Terra and Ovda Regio have thick crust, which are largely supported by isostatic compensation. Other highland plateaus such as Thetis and Phoebe Regiones appear to have superimposed contributions from crustal thickening and dynamic support. Volcanic rises such as Atla and Beta Regiones have thin crust, which is consistent with the postulation that these volcanic rises are mainly the products of dynamic uplift caused by mantle plumes.

  20. WordPress Top Plugins

    Corbin, Brandon

    2010-01-01

    Time flies when you're having fun. This is the right way to describe this WordPress Top Plugins book by Brandon Corbin. With real world examples and by showing you the perks of having these plugins installed on your websites, the author is all set to captivate your interest from start to end. Regardless of whether this is your first time working with WordPress, or you're a seasoned WordPress coding ninja, WordPress Top Plugins will walk you through finding and installing the best plugins for generating and sharing content, building communities and reader base, and generating real advertising r

  1. Beginning WordPress 3

    Leary, Stephanie

    2009-01-01

    One of the most popular open source blogging and content management systems, WordPress lets you create a website to promote yourself or your business quickly and easilyi' "and better yet, it's free. WordPress is a flexible, user-friendly system, and it can be extended with a variety of themes and plugins. Beginning WordPress 3 is a complete guide for the beginning developer who wants to start using WordPress. You'll learn how to publish and manage online content, add media, create widgets and plugins, and much more. What you'll learn * How to get started with Wordpress, create new content

  2. An empirical model of glacio-isostatic movements and shore-level displacement in Fennoscandia

    Shore-level displacement in Fennoscandia is mainly due to two co-operative vertical movements, glacio-isostatic uplift and global eustatic sea level rise. The course of the glacio-isostatic uplift has been made discernible according to an investigation of the lake-tilting phenomenon. This information made it possible to start an iteration process that has given mathematical expression for factors involved both within the isostatic movements and the eustatic rise. There are two components involved in glacio-isostatic uplift. The main uplift, still in progress, acts slowly and is thus called the slow component. Arctan functions have proved to be suitable tools for describing the slow component. There are two main factors involved in the function used for calculation; As (m), the download factor and Bs (y-1 ), which is an inertia factor. A strong linear correlation between the inertia factor Bs and lithosphere thickness has been found in the model. There was also a fast component involved in the crustal changes at the end of Late Weichselian and early Holocene. This component gave rise to fast subsidence followed by fast uplift during the final part of the deglaciation. Crustal subsidence is assumed to be due to reloading of the crust in the central parts of Fennoscandia during the Younger Dryas stadial. Normal distribution functions are used for calculating this component. Glacio-isostatic uplift and thus a regressive shore-level displacement was extremely rapid around 10,300 years BP. This fast regression was contemporaneous and occurred in a similar way at the West Coasts of Norway and Sweden as well as in the Baltic. The 'drainage' of the Baltic Ice Lake has been interpreted in the model as due to this fast regression. The slow component is most probably due to viscous flow in the asthenosphere and the fast component is assumed to be due to its elasticity

  3. An empirical model of glacio-isostatic movements and shore-level displacement in Fennoscandia

    Paasse, T. [Geological Survey of Sweden, Uppsala (Sweden)

    2001-08-01

    Shore-level displacement in Fennoscandia is mainly due to two co-operative vertical movements, glacio-isostatic uplift and global eustatic sea level rise. The course of the glacio-isostatic uplift has been made discernible according to an investigation of the lake-tilting phenomenon. This information made it possible to start an iteration process that has given mathematical expression for factors involved both within the isostatic movements and the eustatic rise. There are two components involved in glacio-isostatic uplift. The main uplift, still in progress, acts slowly and is thus called the slow component. Arctan functions have proved to be suitable tools for describing the slow component. There are two main factors involved in the function used for calculation; A{sub s} (m), the download factor and B{sub s} (y{sup -1} ), which is an inertia factor. A strong linear correlation between the inertia factor Bs and lithosphere thickness has been found in the model. There was also a fast component involved in the crustal changes at the end of Late Weichselian and early Holocene. This component gave rise to fast subsidence followed by fast uplift during the final part of the deglaciation. Crustal subsidence is assumed to be due to reloading of the crust in the central parts of Fennoscandia during the Younger Dryas stadial. Normal distribution functions are used for calculating this component. Glacio-isostatic uplift and thus a regressive shore-level displacement was extremely rapid around 10,300 years BP. This fast regression was contemporaneous and occurred in a similar way at the West Coasts of Norway and Sweden as well as in the Baltic. The 'drainage' of the Baltic Ice Lake has been interpreted in the model as due to this fast regression. The slow component is most probably due to viscous flow in the asthenosphere and the fast component is assumed to be due to its elasticity.

  4. On Gravity Inversion by No-Topography and Rigorous Isostatic Gravity Anomalies

    Sjöberg, Lars E.; Bagherbandi, Mohammad; Tenzer, Robert

    2015-10-01

    We discuss some theoretical aspects and practical consequences of using traditional versus "new"/rigorous formulations of the Bouguer and isostatic gravity anomalies/disturbances. In principle, the differences between these two concepts are in the definition of the so-called secondary indirect topographic effect (SITE) on the gravity data. Although we follow the tradition to call this effect SITE, we show that it is formally a direct topographic effect (DITE), needed to remove all topographic signal, but in practice not regarded as such. Consequently, there is a need for a no- topography gravity anomaly, which removes all topographic effects, leaving the below-crust Earth transparent for gravity inversion. Similarly, a rigorous isostatic gravity anomaly includes also a compensation effect for the SITE. By using a simple topographic model, we confirm a theoretically found ratio of 2/( n + 1) between the magnitudes of the SITE and DITE by wavelength (spherical harmonic degree n), both for the Bouguer and isostatic gravity anomalies. Finally, global gravity inversions are applied by utilizing the Vening Meinesz-Moritz isostatic model to determine the Moho geometry using the Bouguer gravity disturbances/anomalies and the no-topography gravity anomalies, and the results are compared. The numerical results confirm our theoretical findings that the Bouguer gravity disturbances and the no-topography gravity anomalies provide very similar results. A comparison of these gravimetrically computed Moho depths with the CRUST1.0 seismic model shows rms agreements of 4.3 and 4.5 km, respectively. This is a significant improvement when compared to the Moho result obtained by using the Bouguer gravity anomalies, yielding the rms difference of 7.3 km for the CRUST1.0 model. These results confirm a theoretical deficiency of the classical definition of the Bouguer and isostatic gravity anomalies, which do not take into consideration the SITE effects on the topography and its

  5. BuddyPress theme development

    Lister, Tammie

    2013-01-01

    This book is a hands-on tutorial guide to using BuddyPress.This book is great for designers and developers who are looking to learn how to develop BuddyPress themes. It's assumed that the reader has some understanding of Wordpress and is familiar with CSS and HTML.

  6. Head First WordPress

    Siarto, Jeff

    2010-01-01

    Whether you're promoting your business or writing about your travel adventures, Head First WordPress will teach you not only how to make your blog look unique and attention-grabbing, but also how to dig into the more complex features of WordPress 3.0 to make your website work well, too. You'll learn how to move beyond the standard WordPress look and feel by customizing your blog with your own URL, templates, plugin functionality, and more. As you learn, you'll be working with real WordPress files: The book's website provides pre-fab WordPress themes to download and work with as you follow al

  7. Smashing WordPress Themes Making WordPress Beautiful

    Hedengren, Thord Daniel

    2011-01-01

    The ultimate guide to WordPress Themes - one of the hottest topics on the web today WordPress is so much more than a blogging platform, and Smashing WordPress Themes teaches readers how to make it look any way they like - from a corporate site, to a photography gallery and moreWordPress is one of the hottest tools on the web today and is used by sites including The New York Times, Rolling Stone, flickr, CNN, NASA and of course Smashing MagazineBeautiful full colour throughout - web designers expect nothing lessSmashing Magazine will fully support this book by by promoting it through their webs

  8. The development of processes of pressing of articles from powders on the bases of metals, ceramics and graphite

    In the article we offer technological circuits of dry isostatic pressing at the compression in sealed volume and sequential cyclical loading. We represent original process equipment and appropriate technological processes of pressure handling of materials of different properties and compression nature. The offered technologies are designed for the manufacture of a broad spector of articles: porous permeable, constructional, hea-resistant, tools etc on the bases of metals, ceramics and graphite. There are examples of producing of some powder articles and new compositional materials with given properties in manufactured products. (author)

  9. Hot-pressing steatite bodies

    Requirements for some special nuclear engineering ceramic shapes are: big size, impervious, dimensional accuracy and good mechanical and dielectric properties. Limitations of te conventional methods and advantages of te hot pressing techniques for the manufacturing of these shapes are discussed. Hot pressing characteristics of a certain steatite powder are studied. Occurrence of an optimum densification temperature just above the tale decomposition range is found. Experimental data show that the height/diameter ratio of the specimen has no effect on the sintering conditions. Increasing darkness from the graphite mould is detected above the optimum temperature. The hot-pressed steatite is compared with a fired dry-pressed sample of the same composition. (Author) 13 refs

  10. Study of bonding positions of isostatic mounts on a lightweight primary mirror

    Chan, C. Y.; Chen, Y. C.; Chang, S. T.; Huang, T. M.; Hsu, M. Y.

    2012-10-01

    The bonding positions of three isostatic mounts on the primary mirror of a Cassegrain telescope under self-weight loading have both been studied in the paper. Finite element method and Zernike polynomial fitting are complementarily applied to the ZERODUR® primary mirror with a pre-designed lightweight configuration on the back. Eight bonding positions of isostatic mounts with respect to the center of gravity of the mirror have been chosen to investigate the mirror surface deforms as well as the induced optical aberrations. It is found that astigmatism becomes remarkably higher than other optical aberrations under self-weight loading. The optimum bonding position with the least astigmatism value has also been obtained.

  11. Do crustal deformations observed by GPS in Tierra del Fuego (Argentina reflect glacial-isostatic adjustment?

    L. Mendoza

    2010-09-01

    Full Text Available Vertical site velocities determined by geodetic GPS observations in the Lago Fagnano area, Tierra del Fuego main island, are interpreted with respect to their potential relation with the glacial-isostatic crustal response to ice mass changes. The spatial pattern of the uplift rates, in combination with the horizontal crustal deformation pattern, point towards a fault-tectonic rather than glacial-isostatic origin of the determined vertical crustal deformations. This implies rather small GIA effects pointing towards relatively small Holocene ice-mass changes in Tierra del Fuego. However, these findings are considered to be preliminary. They should be confirmed by additional observations covering an extended area with GPS sites.

  12. Press Coverage and Political Accountability

    Snyder, James; Strömberg, David

    2008-01-01

    In this paper we estimate the impact of press coverage on citizen knowledge, politicians' actions, and policy. We find that a poor fit between newspaper markets and political districts reduces press coverage of politics. We use variation in this fit due to redistricting to identify the effects of reduced coverage. Exploring the links in the causal chain of media effects -- voter information, politicians' actions and policy -- we find statistically significant and substantively important effec...

  13. Finite element concept to derive isostatic residual maps - Application to Gorda Plate and Sierra Nevada regions

    K Mallick; K K Sharma

    2001-03-01

    A new space-domain operator based on the shape function concept of finite element analysis has been developed to derive the residual maps of the Gorda Plate of western United States. The technique does not require explicit assumptions on isostatic models. Besides delineating the Gorda Plate boundary, the residual maps exhibit a close match both in their anomaly patterns and magnitudes with previously computed residual maps based on the theory of isostasy.

  14. Empirical estimation of present-day Antarctic glacial isostatic adjustment and ice mass change

    Gunter, B.C.; Didova, O.; Riva, R. E. M.; Ligtenberg, S. R. M.; J. T. M. Lenaerts; King, M.A.; M. R. van den Broeke; T. Urban

    2014-01-01

    This study explores an approach that simultaneously estimates Antarctic mass balance and glacial isostatic adjustment (GIA) through the combination of satellite gravity and altimetry data sets. The results improve upon previous efforts by incorporating a firn densification model to account for firn compaction and surface processes as well as reprocessed data sets over a slightly longer period of time. A range of different Gravity Recovery and Climate Experiment (GRACE) gravity ...

  15. Optimization of a Pressing Diagram in OSB Pressing

    Jaroslav Hrázský

    2011-03-01

    Full Text Available This paper summarizes the results of a pressing diagram optimization based on changes in pressure, temperature and distance between frames of a continuous press during Oriented Strand Boards (OSB pressing. Tests of selected mechanical properties were carried out on OSB/3 boards with a nominal thickness of 18 mm - a basic type with urea-formaldehyd (UF glue in surface layers and isocyanate glue (PMDI in the central layer and further an ECO type with PMDI glue in all layers produced by a prominent manufacturer of OSB boards in the Czech Republic. OSB/3 boards are intended for structural purposes for use in wet environments. Changes in the pressing diagram were carried out at the stage of “press opening”, which signifi cantly affects mechanical and physical properties of OSB boards. In order to be able to compare the effects of changes in the pressing curve, the same setting of production parameters was used with all tested boards. The results of laboratory tests were compared with the values given in the ČSN EN 300 Standard. Optimization of the pressing process ranks among the most effective measures to increase the quality of particle boards at zero or minimum costs. The control of production processes is increasingly perfect thanks to the development of electronics, control and computer technology. At present, not only in our country but also worldwide, marked development of wooden constructions occurs thanks to the development of new types of wood-based composite materials and to the development of technologies in building industry. OSB boards are an important representative of wood-based composite materials for wooden constructions. As compared to natural material, OSB boards show a homogenous structure not including natural defects typical of solid wood. From the point of view of physical and mechanical properties, OSB boards are of orthotropic character.

  16. On the isostatic gravity anomaly and disturbance and their applications to Vening Meinesz-Moritz gravimetric inverse problem

    Sjöberg, Lars E.

    2013-06-01

    In this study, we show that the traditionally defined Bouguer gravity anomaly needs a correction to become `the no-topography gravity anomaly' and that the isostatic gravity anomaly is better defined by the latter anomaly plus a gravity anomaly compensation effect than by the Bouguer gravity anomaly plus a gravitational compensation effect. This is because only the new isostatic gravity anomaly completely removes and compensates for the topographic effect. F. A. Vening Meinesz' inverse problem in isostasy deals with solving for the Moho depth from the known external gravity field and mean Moho depth (known, e.g. from seismic reflection data) by a regional isostatic compensation using a flat Earth approximation. H. Moritz generalized the problem to that of a global compensation with a spherical mean Earth approximation. The problem can be formulated mathematically as that of solving a non-linear Fredholm integral equation. The solutions to these problems are based on the condition of isostatic balance of the isostatic gravity anomaly, and, theoretically, this assumption cannot be met by the old definition of the isostatic gravity anomaly. We show how the Moho geometry can be solved for the gravity anomaly, gravity disturbance and disturbing potential, etc., and, from a theoretical point of view, all these solutions are the same.

  17. A new approach to determine press stiffness

    Arentoft, Mogens; Wanheim, Tarras

    2004-01-01

    deflections are designed. The press stiffness is presented as a 6 by 6 flexibility matrix. The approach has been tested by measuring the stiffness of a 5000 kN O-frame, ring element, hydraulic press, a 10000 kN O-frame, pillar element, hydraulic press and a 10000 kN O-frame, ring element mechanical press......A new procedure is proposed for measuring press stiffness, including separated horizontal and vertical loading of the press frame. The load can be eccentrically positioned for measuring rotational stiffnesses. Two loading devices and corresponding measuring equipment for registration of press...

  18. Oxide formation and precipitation behaviors on interface of F82H steel joints during HIPing and hot pressing

    Joining technologies for F82H steels are important issues for the development of fusion energy. The hot isostatic pressing (HIP) method is appropriate for consolidating the first wall of the blanket because of the flexibility of the shape of HIPed products. The HIP method is planned for fabricating a complex-shaped first wall component with built-in cooling channels; thus, accumulation of studies of microstructural and mechanical property changes, especially lower toughness of the HIPed joints, is essential. Present research aims to reveal the microstructural evolution of F82H joints fabricated by the HIP method compared with joints fabricated by hot pressing, focusing on the formation of oxides on the interface. F82H joints were characterized using 1/3-scale Charpy V-notch impact test, transmission electron microscope, scanning electron microscope, and electron probe analysis to survey the microstructural characteristics of the interface

  19. WordPress 3 Cookbook

    Shreves, Ric

    2011-01-01

    This is a Packt Cookbook, which means it contains step-by-step instructions to achieve a particular goal or solve a particular problem. There are plenty of screenshots and explained practical tasks to make comprehension quick and easy. This book is not specifically for developers or programmers; rather it can be used by anyone who wants to get more out of their WordPress blog by following step-by-step instructions. A basic knowledge of PHP/XHTML/CSS/WordPress is desirable but not necessary.

  20. Scheme of 3 interfaces with local isostatic compensation on the Argentine continental margin

    Pedraza De Marchi, A. C.; Ghidella, M. E.; Tocho, C.

    2013-05-01

    The segment of Argentine continental margin located between 39°S and the Malvinas platform (~49°S) is of passive type and volcanic characteristics revealed by seaward-dipping seismic reflectors sequences (SDRs). The free air gravity edge-effect associated with passive continental margins is one of the most distinctive characteristics of gravity in marine regions. This effect is in large part due to the transition between continental and oceanic crusts, because of their different thicknesses. In this presentation we investigate the Airy type isostatic compensation scheme by using three interfaces in a forward calculation with different approximations of Parker's expression to obtain the isostatic anomaly. After that we perform the inversion of the anomaly thus obtained in order to find the Moho's deflection necessary to compensate it (or minimize it) by using the same scheme of interfaces and the iterative Parker-Oldenburg method (Oldenburg, D., 1974) with more terms in the inversion. The crust-mantle interface (Moho) thus calculated represents a more realistic surface than the one calculated using one term in the inversion and the surface estimated with topographic data and sediment thickness. Even considering that the experiment constitutes a schematic assumption just to test the numerical methods involved, we find that in the comparison with the only available digitized refraction profile, the inverted Moho interface reproduces fairly well the Moho that the seismic profile yields, for the case of the iterative method. This suggests that the inverse calculation with the iterative method is sensible to the presence of the SDRS, at least for this sole profile. Keywords: isostatic anomaly, Moho, passive continental margins Oldenburg, D., 1974. The inversion and interpretation of gravity anomalíes, Geophysics, vol. 39, no. 4, p. 526-536.

  1. NATIONAL ACADEMY PRESS WEB SITE

    The National Academy Press is the publisher for the National Academy of Sciences, the National Academy of Engineering, the Institute of Medicine, and the National Research Council. Through this web site, you have access to a virtual treasure trove of books, reports and publicatio...

  2. Local and international press digest

    2008-01-01

    The following are the top stories in the Maltese and the international press today. The Times gives prominence to the Prime Minister's flying visit to Geneva yesterday, where he signed a research cooperation agreement with CERN, the European nuclear research organisation.

  3. Recrystallization of pressed technical uranium

    The objective of this task was to study changes originating from heat treatment of uranium by metallographic methods and by measuring the hardness. Correlation of previously determined textures with the present study would improve the knowledge on the recrystallization process of pressed uranium

  4. Density Structure, Isostatic Balance and Tectonic Models of the Central Tien Shan

    M. K. Kaban; T. Reiza Yuanda

    2014-01-01

    A new combined satellite-terrestrial model of the gravity field is used together with seismic data for construction of a density model of the lithosphere of the Central Tien Shan and for estimation of its isostatic balance. The Tien Shan is one of the most active intraplate orogens in the world, located about 1,500 km north of the convergence between Indian and Eurasian plate, and surrounded by stable Kazakh platform to the north and the Tarim block to the south. Although this area was extens...

  5. Effect of isostatic rebound on modelled ice volume variations during the last 200 kyr

    M. Crucifix; Loutre, M. F.; Lambeck, K.; Berger, A.

    2001-01-01

    Deformation of the lithosphere under an ice load can be approximated using the hypothesis of local damped isostasy. This simple formulation has been systematically compared with a three-dimensional model of the crust-mantle system for simple ice-load scenarios with a period in the range 20-100 kyr. The comparison enables us to introduce the concepts of effective upper mantle density and effective relaxation time into the isostatic model for the response of the Earth to the ice sheets. These p...

  6. Teach yourself visually WordPress

    Majure, Janet

    2012-01-01

    Get your blog up and running with the latest version of WordPress WordPress is one of the most popular, easy-to-use blogging platforms and allows you to create a dynamic and engaging blog, even if you have no programming skills or experience. Ideal for the visual learner, Teach Yourself VISUALLY WordPress, Second Edition introduces you to the exciting possibilities of the newest version of WordPress and helps you get started, step by step, with creating and setting up a WordPress site. Author and experienced WordPress user Janet Majure shares advice, insight, and best practices for taking full

  7. Smashing WordPress Beyond the Blog

    Hedengren, Thord Daniel

    2012-01-01

    The ultimate guide to WordPress, from the world's most popular resource for web designers and developers As one of the hottest tools on the web today for creating a blog, WordPress has evolved to be much more that just a blogging platform and has been pushed beyond its original purpose. With this new edition of a perennially popular WordPress resource, Smashing Magazine offers you the information you need so you can maximize the potential and power of WordPress. WordPress expert Thord Daniel Hedengren takes you beyond the basic blog to show you how to leverage the capabilities of WordPress to

  8. Modularity of Pressing Tools for Screw Press Producing Solid Biofuels

    Miloš Matúš; Peter Križan

    2012-01-01

    This paper focuses on the development of the newly-patented structure of a screw briquetting machine for compacting biomass into a solid biofuel. The design of the machine is based on the results of a comprehensive study of the complicated process of biomass compaction. The patented structure meets two main goals: the elimination of axial forces, leading to increased lifetime of the bearings, and the new modular design of a pressing chamber and tools with their geometry based on the applicati...

  9. Theory of supersymmetry ``protected'' topological phases of isostatic lattices and highly frustrated magnets

    Lawler, Michael

    I generalize the theory of phonon topological band structures of isostatic lattices to highly frustrated antiferromagnets. I achieve this with a discovery of a many-body supersymmetry (SUSY) in the phonon problem of balls and springs which also applies to geometrically frustrated magnets. The Witten index of the SUSY model, when restricted to the single body problem (meaningful for linearized phonons), is then shown to be the Calladine-Kane-Lubensky index of mechanical structures that forms the cornerstone of the phonon topological band structure theory. ``Spontaneous supersymmetry breaking'' is then identified as the need to gap all modes in the bulk to create the topological state. The many-body SUSY formulation shows that the topology is not restricted to a band structure problem but extends to systems of coupled bosons and fermions that are in principle also realizable in solid state systems. The analogus supersymmetry of the magnon problem turns out to be particularly useful for highly frustrated magnets with the kagome family of antiferromagnets an analog of topological isostatic lattices. Thus, a solid state realization of the theory of phonon topological band structure may be found in highly frustrated magnets. However, our results show that this topology is protected not

  10. ISS Expedition 21/22 Press Kit

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 21/22 from 10/2009-03/2010. Press kits contain information about each mission overview, crew, mission timeline, benefits, and...

  11. A Conversation with Frank Press

    Goodstein, Judith R.

    Geophysicist Frank Press was director of Caltech's Seismological Laboratory from 1957 to 1965. In this interview, he recalls his work with Maurice Ewing at Columbia's Lamont Geological Observatory; his directorship of Caltech's Seismological Laboratory and colleagues Charles Richter, Beno Gutenberg, and Hugo Benioff; his work on the free oscillations of the earth; and his part in establishing the worldwide network of seismographs for the detection of nuclear weapons testing.

  12. Incremental Pressing Technique in Explosive Charge

    2001-01-01

    A pressing technique has become available that might be useful for compressing granular explosives. If the height-diameter ratio of the charge is unfavorable,the high quality charge can not be obtained with the common single-action pressing. This paper presents incremental pressing technique, which can obtain the charge with higher overall density and more uniform density.

  13. Simultaneous veneers incising and lower pressing temperatures?the effect on the plywood pressing time

    Kurowska, A; Borysiuk, P.; Mamiński, M. Ł.

    2010-01-01

    Abstract It was shown that incising of veneers (60?15 m/m2) prior to plywood bonding allowed reduction of pressing time by 8?9% for a pressing temperature of 90?C when compared to the controls. Nevertheless, with pressing temperatures lower than normal and shortened pressing times the shear strengths of the plywood met the requirements of the respective standards.

  14. Modularity of Pressing Tools for Screw Press Producing Solid Biofuels

    Miloš Matúš

    2012-01-01

    Full Text Available This paper focuses on the development of the newly-patented structure of a screw briquetting machine for compacting biomass into a solid biofuel. The design of the machine is based on the results of a comprehensive study of the complicated process of biomass compaction. The patented structure meets two main goals: the elimination of axial forces, leading to increased lifetime of the bearings, and the new modular design of a pressing chamber and tools with their geometry based on the application of a mathematical model.

  15. RELATIONSHIP BETWEEN COMPACTING PRESSURE AND CONDITIONS IN PRESSING CHAMBER DURING BIOMASS PRESSING

    Peter Križan

    2016-02-01

    Full Text Available In this paper, we will present the impact of the conditions in pressing chambers during the pressing of wooden briquettes. The conditions in pressing chambers can significantly impact the resulting compacting pressure required for the pressing of briquettes. In the introduction, we show which parameters of the pressing chamber during pressing can impact the resulting compacting pressure. The experiment results which are shown in this paper described the detected impact of some important pressing chamber parameters. This experiment aims to detect the pressing chamber length impact and the impact of the way of pressing. By setting the pressing conditions, we will be able to achieve the suitable resulting compacting pressure with respect to the required final briquettes quality.

  16. Professional WordPress design and development

    Williams, Brad; Stern, Hal

    2014-01-01

    The highest rated WordPress development and design book on the market is back with an all new third edition. Professional WordPress is the only WordPress book targeted to developers, with advanced content that exploits the full functionality of the most popular CMS in the world. Fully updated to align with WordPress 4.1, this edition has updated examples with all new screenshots, and full exploration of additional tasks made possible by the latest tools and features. You will gain insight into real projects that currently use WordPress as an application framework, as well as the basic usage a

  17. Dissoluzione Elettrochimica del Can per la Produzione di Manufatti 'Near Net Shape' in Ti6Al4V ottenuti mediante Hot Isostatic Pressing

    Scherillo, Fabio

    2015-01-01

    Il seguente lavoro di tesi si inserisce all'interno del progetto di ricerca "TitaForm", inserito nella costellazione "Titanium", che rappresenta un'iniziativa industriale italiana per le tecnologie del titanio ad uso aeronautico. L'utilizzo sempre crescente della percentuale di composito a matrice polimerica richiede, parimenti, una percentuale di titanio sempre crescente nelle strutture aeronautiche primarie, non solo dei motori ed asservimenti. L'industria aeronautica moderna deve ris...

  18. The influence of high thermal gradient casting, hot isostatic pressing and alternate heat treatment on the structure and properties of a single crystal nickel base superalloy

    Fritzemeier, L. G.

    1988-01-01

    A development program has been conducted to improve the cyclic properties of the PWA 1480 single-crystal superalloy by reducing or entirely eliminating casting porosity at fatigue-initiation sites, through the use of improved casting process parameters and HIPing; potential mechanical property improvements in a high-pressure hydrogen environment were also sought in alternatives to the standard coating and heat-treatment cycle. High thermal gradient casting was found to yield a reduction in overall casting porosity density and pore sizes. The most dramatic mechanical property improvement resulted from HIPing.

  19. Internal stresses and breakup of rigid isostatic aggregates in homogeneous and isotropic turbulence

    De Bona, Jeremias; Vanni, Marco

    2014-01-01

    By characterising the hydrodynamic stresses generated by statistically homogeneous and isotropic turbulence in rigid aggregates, we estimate theoretically the rate of turbulent breakup of colloidal aggregates and the size distribution of the formed fragments. The adopted method combines Direct Numerical Simulation of the turbulent field with a Discrete Element Method based on Stokesian dynamics. In this way, not only the mechanics of the aggregate is modelled in detail, but the internal stresses are evaluated while the aggregate is moving in the turbulent flow. We examine doublets and cluster-cluster isostatic aggregates, where the failure of a single contact leads to the rupture of the aggregate and breakup occurs when the tensile force at a contact exceeds the cohesive strength of the bond. Due to the different role of the internal stresses, the functional relationship between breakup frequency and turbulence dissipation rate is very different in the two cases. In the limit of very small and very large valu...

  20. Incomplete separability of Antarctic plate rotation from glacial isostatic adjustment deformation within geodetic observations

    King, Matt A.; Whitehouse, Pippa L.; van der Wal, Wouter

    2016-01-01

    Geodetic measurements of Antarctic solid Earth deformation include signals from plate rotation and glacial isostatic adjustment (GIA). Through simulation, we investigate the degree to which these signals are separable within horizontal GPS site velocities that commonly define plate rotation estimates and that promise new constraints on models of GIA. Using a suite of GIA model predictions that incorporate both 1-D and 3-D Earth rheologies, we show that, given the present location of GPS sites within East Antarctica, unmodelled or mismodelled GIA signal within GPS velocities produces biased estimates of plate rotation. When biased plate rotation is removed from the GPS velocities, errors as large as 0.8 mm yr-1 are introduced; a value commonly larger than the predicted GIA signal magnitude. In the absence of reliable forward models of plate rotation or GIA then Antarctic geodetic velocities cannot totally and unambiguously constrain either process, especially GIA.

  1. An isostatic study of the Karoo basin and underlying lithosphere in 3-D

    Scheiber-Enslin, Stephanie E.; Ebbing, Jörg; Webb, Susan J.

    2016-08-01

    A 3-D density model of the crust and upper mantle beneath the Karoo basin is presented here. The model is constrained using potential field, borehole and seismic data. Uplift of the basin by the end of the Cretaceous has resulted in an unusually high plateau (>1000 m) covering a large portion of South Africa. Isostatic studies show the topography is largely compensated by changes in Moho depths (˜35 km on-craton and >45 km off-craton) and changes in lithospheric mantle densities between the Kaapvaal Craton and surrounding regions (˜50 kg m-3 increase from on- to off-craton). This density contrast is determined by inverted satellite gravity and gravity gradient data. The highest topography along the edge of the plateau (>1200 m) and a strong Bouguer gravity low over Lesotho, however, can only be explained by a buoyant asthenosphere with a density decrease of around 40 kg m-3.

  2. Towards Constraining Glacial Isostatic Adjustment in Greenland Using ICESat and GPS Observations

    Nielsen, Karina; Sørensen, Louise Sandberg; Khan, Shfaqat Abbas;

    2014-01-01

    . We find, that the temporal behavior of the ICESat-based modeled elastic response agrees well with the GPS observations at the sites KELY, QAQ1, and SCOR. This suggests, that our elastic models are able to resolve the temporal changes in the observed uplift, which indicates that the elastic uplift......Constraining glacial isostatic adjustment (GIA) i.e. the Earth’s viscoelastic response to past ice changes, is an important task, because GIA is a significant correction in gravity-based ice sheet mass balance estimates. Here, we investigate how temporal variations in the observed and modeled...... pattern of elastic crustal displacements shows pronounced variation during the observation period, where an increase in elastic displacement is found at the northwest coast of Greenland, while a decrease is found at the southeast coast. This pattern of temporal changes is supported by the GPS observations...

  3. Insights into the Crustal Structure and Geodynamic Evolution of the Southern Granulite Terrain, India, from Isostatic Considerations

    Kumar, Niraj; Singh, A. P.; Singh, B.

    2011-10-01

    The Southern Granulite Terrain of India, formed through an ancient continental collision and uplift of the earth's surface, was accompanied by thickening of the crust. Once the active tectonism ceased, the buoyancy of these deep crustal roots must have supported the Nilgiri and Palani-Cardamom hills. Here, the gravity field has been utilized to provide new constraints on how the force of buoyancy maintains the state of isostasy in the Southern Granulite Terrain. Isostatic calculations show that the seismically derived crustal thickness of 43-44 km in the Southern Granulite Terrain is on average 7-8 km more than that required to isostatically balance the present-day topography. This difference cannot be solely explained applying a constant shift in the mean sea level crustal thickness of 32 km. The isostatic analysis thus indicates that the current topography of the Southern Granulite Terrain is overcompensated, and about 1.0 km of the topographic load must have been eroded from this region without any isostatic readjustment. The observed gravity anomaly, an order of magnitude lower than that expected (-125 mGal), however, shows that there is no such overcompensation. Thermal perturbations up to Pan-African, present-day high mantle heat flow and low Te together negate the possible resistance of the lithosphere to rebound in response to erosional unloading. To isostatically compensate the crustal root, compatible to seismic Moho, a band of high density (2,930 kg m-3) in the lower crust and low density (3,210 kg m-3) in the lithospheric mantle below the Southern Granulite Terrain is needed. A relatively denser crust due to two distinct episodes of metamorphic phase transitions at 2.5 Ga and 550 Ma and highly mobilized upper mantle during Pan-African thermal perturbation reduced significantly the root buoyancy that kept the crust pulled downward in response to the eroded topography.

  4. Pengaruh Tekanan Pada Screw Press Terhadap Persentase Kehilangan Minyak Kelapa Sawit Yang Terdapat Pada Ampas Press

    Saragih, Nataniel

    2010-01-01

    Percentage loss of palm oil from the pulp press influence the quality of palm oil. Pressing process is influenced by the type of the screw press, screw press working pressure, and water dilution. Percentage loss of palm oil from the pulp press is 3,12 – 2,90 % where the value is taken from the percentage of oil that had not dry the air. Percentage loss of palm oil from the pulp press fit standard factory that is 3,0 – 3,7 %. 072409001

  5. Smashing WordPress Beyond the Blog

    Hedengren, Thord Daniel

    2011-01-01

    Smashing WordPress shows you how to utilize the power of the WordPress platform, and provides a creative spark to help you build WordPress-powered sites that go beyond the obvious. The second edition of Smashing WordPress has been updated for WordPress 3.1+, which includes internal, custom post types, the admin bar, and lots of other useful new features. You will learn the core concepts used to post types, the admin bar, and lots of other useful new features. You will learn the core concepts used to build just about anything in WordPress, resulting in fast deployments and greater design flexib

  6. WordPress 3.7 complete

    Król, Karol

    2013-01-01

    WordPress 3.5 Complete: Third Edition is a comprehensive and step-by-step tutorial packed with screenshots and examples to make it easy and quick to pick it up.This WordPress book is a guide to WordPress for online publishers and web developers. If you are new to blogging and want to create your own blog or website from scratch, then ""WordPress 3.5 Complete: Third Edition"" is for you. No prior knowledge of HTML/CSS or PHP is required.

  7. Activation of Selected Core Muscles during Pressing

    Thomas W. Nesser

    2015-10-01

    Full Text Available Introduction: Unstable surface training is often used to activate core musculature during resistance training. Unfortunately, unstable surface training is risky and leads to detraining. Purpose: The purpose of this study was to determine core muscle activation during stable surface ground-based lifts. Methods: Fourteen recreational trained and former NCAA DI athletes (weight 84.2 ± 13.3 kg; height 176.0 ± 9.5 cm; age 20.9 ± 2.0 years volunteered for participation. Subjects completed two ground-based lifts: overhead press and push-press. Surface EMG was recorded from 4 muscles on the right side of the body (Rectus Abdominus (RA, External Oblique (EO, Transverse Abdominus (TA, and Erector Spinae (ES. Results: Paired sample T-tests identified significant muscle activation differences between the overhead press and the push-press included ES and EO. Average and peak EMG for ES was significantly greater in push-press (P<0.01. Anterior displacement of COP was significantly greater in push-press compared to overhead press during the eccentric phase. Conclusion: The push-press was identified as superior in core muscle activation when compared to the overhead pressing exercise.Keywords: torso, stability, weight lifting, resistance training

  8. Damping test results for straight sections of 3-inch and 8-inch unpressurized pipes

    EG and G Idaho is assisting the Nuclear Regulatory Commission and the Pressure Vessel Research Committee in supporting a final position on revised damping values for structural analyses of nuclear piping systems. As part of this program, a series of vibrational tests on unpressurized 3-in. and 8-in. Schedule 40 carbon steel piping was conducted to determine the changes in structural damping due to various parametric effects. The 33-ft straight sections of piping were supported at the ends. Additionally, intermediate supports comprising spring, rod, and constant-force hangers, as well as a sway brace and snubbers, were used. Excitation was provided by low-force-level hammer impacts, a hydraulic shaker, and a 50-ton overhead crane for snapback testing. Data was recorded using acceleration, strain, and displacement time histories. This report presents test results showing the effect of stress level and type of supports on structural damping in piping

  9. 8-inch Reflange Inlet and Two 6-inch 600# Flange Outlets Relief Valve Description and Specifications

    2005-01-01

    In the past, an Anderson Greenwood (AG) pilot operated relief valve was used to protect the E-1 rocket engine test facility. It was found that the AG valve is destroyed and discharges internal parts at a great velocity on opening. This is a major safety and cost issue. The solution is a relief valve to match present Anderson Greenwood pilot valve A 8z B dimensions. The valve is to use a precise buckling pin obeying Euler s Law to act as the pressure sensor and actuator. The valve must not self destruct on opening.

  10. IDEAL: ACADEMIC PRESS JOURNALS ONLINE

    The Library

    2001-01-01

    All Academic Press journals are available online to CERN users for a test period which will last until the end of July. The service 'IDEALIBRARY' includes 174 scientific journals that cover several domains, ranging from engineering to mathematics, computing and physics. Titles covered are among others 'Atomic Data and Nuclear Data Tables', 'Nuclear Data Sheets', 'Annals of Physics', 'Journal of Parallel and Distributed Computing'. Reference citations present in each article are linked to the corresponding full text, when the latter is published by a member of the CrossRef consortium (members are: Elsevier, APS, AIP and others). Therefore, the navigation between articles and references is uninterrupted. A search engine allows queries by author, title and publication year. See http://www.idealibrary.com. At present the Library is evaluating a site license offer proposed by the publisher.