[en] The authors previously described two human monoclonal antibodies (MAbs) which inactivated factor V. The authors have now purified the predominant antibody (H2) on protein A Sepharose using a pH gradient and typed it as IgG₁,. Immunoprecipitation of ¹²⁵I-human factor Va with H2 demonstrated specificity for the heavy chain (D), Mr = 105,000. The authors compared using ELISA the competitive binding to factor Va, of H2, H1 and two mouse MAbs, B38 (directed to E) and B10 (to activation peptide, Cl). All four antibodies recognized distinct epitopes in factor V with steric overlap in some cases. Factor Xa showed a concentration dependent competition for binding of H1, H2 and B38 but not B10 to factor V/Va in ELISA. All MAbs bound to factor V/Va in the absence of Ca⁺⁺. However, Ca⁺⁺ at 8 mM increased the binding of H1 and H2 to 165% and 360% and did not have any effect on the binding of either mouse MAbs. Prothrombin at a concentration of up to 400 μg/ml did not inhibit binding of any of these antibodies. Thus, both the light (E) and heavy (D) chains of factor Va but not the activation peptide (Cl) interact with factor Xa as defined by the MAbs. In addition, sites on both chains for Ca⁺⁺ are recognized by particular MAbs (H1 and H2). These studies increase their knowledge of the interactions of factor V domains in the formation of prothrombinase complex

[en] The phase mineralogy and leaching characteristics of some Indian coal fly ashes were studied to assess their safe disposal in abandoned coal mines. Since, fly ash contains a number of toxic trace elements, the leaching of fly ash was tested using strong acid/alkali solutions and distilled water under different conditions (solid-liquid ratio, leaching time, pH) in the temperature range of 30-100 degree C. It was found that the concentration of various metals in leachates depends on their chemical nature, association with mineral phases of ash and follows the almost similar concentration profile to that of iron, especially in acidic medium. The distribution of toxic trace elements in fly ash and their leachability were found to depend on the amount of unburnt carbon and iron in fly ash. In alkaline medium, leaching of iron and toxic trace elements (except As) from fly ash was very negligible. Hence, alkali treatment of coal fly ash is desirable for its safe use in refilling of coal mines. 27 refs., 14 figs., 8 tabs

[en] In this work we have analysed the two-phase flow and heat transfer in the porous debris bed form during late-phase invessel severe accident scenario in light water reactors. The heat transfer in debris bed is limited by dryout heat flux. We have carried out calculation of dryout heat flux based on different zero-dimensional two-phase flow models in porous bed. We have suggested improvement over the existing models based numerical optimization for dryout heat flux. We have also studied the behavior of vertical profile of saturation over a wide range of volumetric heat generation rate. The effects of porous media hydrodynamic model parameters have been explored. (author)

[en] The performance of a prototype fast/slow scintillator telescope consisting of a 75μ fast plastic (BC 412) as ΔE and a 4 mm thick slow plastic (BC444) as E detector is reported. The size of the detector is 10mm x10mm. Two different methods have been employed to couple the scintillators. In one case, detectors were coupled using a very thin layer of BC600 optical glue. Alternately it was tried to sandwich them thermally keeping them under controlled temperature for two hours. The temperature was set at 70deg C. The phoswich detector so formed was coupled to Thorn-EMI 9826B PMT with optical cement. The applied bias voltage was -1000V and anode signal was taken for processing. In case of optical gluing, dead layer due to excess glue material affects the light output whereas in thermal gluing, the trapped air layer degrades it

[en] Short communication. 12 refs., 1 fig., 1 tab

[en] This paper presents evidence of the anomalous interaction mean free path of the relativistic alpha particles emitted from the interaction of ¹²C with emulsion nuclei at 4.5 GeVc per nucleon. The tracks were followed systematically through the stack. The detailed measurements show clearly that the interaction mean free path is anomalously shorter for a fewer centimeters after their emission. The results have been compared with other results obtained from both accelerator and cosmic-ray data

[en] Non-equilibrium processing techniques such as mechanical alloying/mechanical milling can be adopted to study the synthesis of ductile intermetallics in the form of nanocomposites and their stability as well as mechanical properties. There are common intermetallics with γ-brass structure in number of Al-based ternary systems. The γ-phase evolving at about 21/13 electrons/atom ratio is commonly considered the structurally most complex Hume-Rothery phases. Technological exploitation of such phases has been a continuous challenge for scientists due to their structural complexity and intricate physical properties. In fact subtle variations of the valence electron concentration can trigger the formation of structurally different phases. In the present investigation we have synthesized nanocrystalline phase by mechanical milling and rapid solidification technique using the as cast γ-phase alloys in Al-Cu-Fe, Al-Cr-Cu and Al-Cr-Fe systems. The characterization of the milled, RSP and as-cast materials were carried out by X-ray diffraction, DTA, DSC, transmission electron microscopy (TEM) and HRTEM in order to study the microstructural evolution and stability of various phases. Results show that the mixture of amorphous phases with nano crystals of γ-phase is present in most of the above systems. Thus, attempts have been made to explore the possibility of formation of nanostructured and amorphous phases by mechanical milling and to explain the evolution of the phases based on Miedema model considering the grain size effects on the free energy in nano scale. (author)

[en] Sm³⁺ singly doped and Sm³⁺ co-doped with varying concentration of ZnS nanoparticles (ZnS NPs) in silica matrix were fabricated via sol-gel route and investigated by various structural, thermo-gravimetric and spectroscopic techniques. Structural characterizations were done by XRD, EDX, TEM and FTIR whereas thermo-gravimetric characterization was performed by TGA/DTG technique. The structural studies reveal the presence of nanosized ZnS particles in the amorphous silica matrix. Spectroscopic studies were performed through absorption, excitation, emission and decay spectra of the fabricated samples. The dependence of Judd-Ofelt and various radiative parameters of Sm³⁺ on the concentration of ZnS NPs in the studied matrix were evaluated. Significantly high value of Ω₂ obtained for the present system reveals effective network modifying nature of the ZnS NPs. The PL behaviour showed strong concentration dependence on ZnS NPs and showed optimum for the ZnS concentration of 0.5 M. The emission transition ⁴G_5/2 → ⁶H_9/2 of Sm³⁺ corresponding to the red colour observed at 642 nm for silica matrix in the present study showed excellent radiative behaviour compared to other popular glass hosts. This indicates ZnS NPs co-doped Sm³⁺ sol-gel silica matrix to be a prospective candidate for laser and other optical device applications.

[en] The Pre-Series Cryoline (PTCL) for ITER is a representative cryoline from the complicated network of all cryolines for the ITER project. It is ∼28 m in length with same cross-section (1:1) including main line (ML) and branch line (BL) as of ITER torus and cryostat cryoline. Geometrically; it has bends at different angles i.e. 90°, 120°, 135° and 160° comprising T-section and Z-section. The PTCL has been fabricated in 5 different elements based on the installation feasibility. The mechanical and instrumentation installation like sensors mounting, displacement sensors, etc. has been completed. The PTCL test has been performed after complete installation of PTCL and integration with the existing test facility at ITER-India cryogenics laboratory in order to verify the thermal performance and mechanical integrity. The primary objectives, which are evaluated during the PTCL test, are (i) Thermal performance of the PTCL (ii) Measurement of temperature profile on thermal shield of PTCL, (iii) Stress measurement at critical locations, (iv) Measurement of Outer Vacuum Jacket (OVJ) temperature during Break of Insulation Vacuum (BIV) test. The paper will summarize the methodology and observed results of PTCL. (paper)

[en] Using a specially designed off-axis faced magnetron sputtering chamber we have performed in situ x-ray diffraction studies of the growth of YBa₂Cu₃O_x films using a synchrotron light source. The orientation and rocking curve width were studied as a function of substrate temperature, O₂/Ar partial pressures, and deposition rate. Growth rate was studied on SrTiO₃, LaAlO₃, and MgO