Replica of Sink Ability Test with Beeker Test

The sink-ability test is to be carried out frequently for the pellets made during winter season, since surface tension of water during low temperature is high. Pellets have to break surface tension to sink into the water. This test will be carried out morning hours at around 6:00 Am at ponds. During every startup of production or during new formulation, this test is mandatory. Normally ponds are away from factory, carrying out of this test is became a big issue to the quality control team to confirm the sink ability. This is to be made easy by making replica of pond test.

Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities: Part 9 — Ultimate Properties of Full-Scale Lead Rubber Bearings Based on Breaking Test

This paper presents a part of “Development of an Evaluation Method for Seismic Isolation Systems of Nuclear Power Facilities”. Ultimate behavior and failure modes of full-scale Lead Rubber Bearings (LRBs) of 1600mm diameter were described herein based on a series of the break tests which conducted on 11 LRBs to obtain a break surface. The shear break tests were monotonically conducted on 3 full-scale LRBs under various axial stresses. Then the monotonic tensile break tests were performed on 5 full-scale LRBs with or without constant offset shear strain. In addition, 3 half-scale LRBs of 800mm diameter were also tested to study the size effect and the ultimate shear behavior in significantly high compression. In the evaluation on the test results, the ultimate strain and stress were firstly summarized to define a break surface for the real-scale LRBs. Then the LRBs broken in the testing were carefully observed to evaluate their failure modes. It was found that the full-scale LRBs exhibited good seismic performance in horizontal ductility capacity and vertical load carrying capacity. It seems that the ultimate properties and the failure modes were basically less affected by the scale of the models.

Hyperthermophilic and salt-dependent formyltransferase from Methanopyrus kandleri

Methanopyrus kandleri is a hyperthermophilic methanogenic archaeon, which grows on H2 and CO2 as its sole energy source. Its growth temperature optimum is 98°C. One of the interesting characteristics of this archaeon is its high intracellular salt content. The organism has been reported to contain the trianionic cDPG (cyclic 2,3-diphosphoglycerate) and K+ at concentrations of 1.1 and 3 M, respectively. Reflecting the high cellular salt concentration, the enzymes in this organism are adapted not only to high temperature but also to high salt concentrations. The formyltransferase from M. kandleri was characterized extensively with respect to thermo- and halophilicity. The crystal structure of the formyltransferase at 1.73 Å shows the enzyme to be composed of four identical subunits of molecular mass 32 kDa. The formyltransferase is thermostable and active only at relatively high concentrations of potassium phosphate (1 M) or other salts with strongly hydrated anions (strong salting-out salts). Potassium phosphate and potassium cDPG were found to be equivalent in activating and stabilizing the enzyme. At low concentrations of these salts, the enzyme is inactive and thermolabile. It was shown by equilibrium sedimentation analysis that the enzyme is in a monomer/dimer/tetramer equilibrium, the equilibrium constant being dependent on the concentration of salts: the higher oligomeric species increase with increasing salt concentrations. Evidence was provided that the monomer is both inactive and thermolabile. Experiments using a mutation which is directed to break surface ion pairs between two dimers indicated that dimerization is required for activity and tetramerization leads to thermostability.

Activation of the Si(100)/Cl2 Etching Reaction at High Cl2 Translational Energies

Exposing a Si(100) surface to a pulsed beam of neutral Cl2 with high translational energy results in etching at a rate faster than that seen with chlorine at thermal energies. The Cl2 beam used in these experiments is produced by laser vaporization of cryogenic films. It has a broad energy distribution which can be varied by changing laser energy and film thickness. Beams with mean energies as low as 0.4 eV result in etching =10 times faster than etching by thermal Cl2. When Cl2 beams are used which have considerable flux above 3 eV, the etching rate increases by a further factor of 3.6 ± 0.6. This rate increase, which occurs at energies just above the Si-Si bond energy, suggests that kinetic energy can be efficiently utilized to break surface bonds.

Coastally trapped waves, baroclinic eddies, internal tides and oceanic fronts at the shelf break: their implications for exchanges between shelf and oceanic waters

The seaward edge of the continental shelf, or shelf break, is the locus of strong physical variability in the overlying waters. Near the shelf-break, surface tides scatter energy into internal modes that propagate both onshore and offshore and produce strong vertical shears. Atmospheric forcing generates subinertial-frequency topographic Rossby waves, which propagate parallel to the coastline and are strongly trapped near the shelf break. Relative to the sloping topography, wind-driven coastal upwelling generates prograde fronts, and river run-off generates retrograde fronts. Located near the shelf break, these fronts are boundaries between oceanic and coastal waters. Oceanic eddies impinge on, and move along, the shelf-break entraining coastal waters. Eddies may also be shed by shelf-break fronts. Submarine capes and canyons contort the shelf break and significantly modify the enumerated processes. Based on observational evidence from a few coastal regimes, the shelf break is a zone where several mesoscale and synoptic-scale processes operate and probably produce significant turbulent transfers.