Magnetic Field Measurement System in Superconducting Combined Function Magnets for the J-PARC Neutrino Beam Line

Magnetic field measurements have been performed for the first full-scale magnet system assembled with the cryostat for the J-PARC proton beam line of neutrino experiment. In the measurement system, the probe position with respect to magnet central axis is measured by a Helium Neon laser and a position sensitive detector, PSD, in order to obtain an exact dipole field strength. Errors associated with the PSD misalignment and influences on the PSD signals by the magnetic field were evaluated. The measured dipole components approached to the design values by compensating those with the probe position. The latest beam simulation indicated that the measured values of magnetic field were good enough for the primary proton beam transport.     

Enhancement of Student Learning in Experimental Design Using a Virtual Laboratory

This paper describes the instructional design, implementation, and assessment of a virtual laboratory based on a numerical simulation of a chemical vapor deposition (CVD) process, the virtual CVD laboratory. The virtual CVD laboratory provides a capstone experience in which students synthesize engineering science and statistics principles and have the opportunity to apply experimental design in the context similar to that of a practicing engineer in industry with a wider design space than is typically seen in the undergraduate laboratory. The simulation of the reactor is based on fundamental principles of mass transfer and chemical reaction, obscured by added ldquonoise.rdquo The software application contains a 3-D student client that simulates a cleanroom environment, an instructor Web interface with integrated assessment tools, and a database server. As opposed to being constructed as a direct one-to-one replacement, this virtual laboratory is intended to complement the physical laboratories in the curriculum so that certain specific elements of student learning can be enhanced. Implementation in four classes is described. Assessment demonstrates students are using an iterative experimental design process reflective of practicing engineers and correlates success in this project to higher order thinking skills. Student surveys indicate that students perceived the virtual CVD laboratory as the most effective learning medium used, even above physical laboratories.     

Desiccation survival of Listeria monocytogenes and other potential foodborne pathogens on stainless steel surfaces is affected by different food soils

Food processing environments are suspected to be the primary source of Listeria monocytogenes contamination of foods. We investigated the survival of L. monocytogenes on stainless steel that was soiled with food components (minced tuna, ground pork, and cabbage) followed by dehydration. Stainless steel coupons were inoculated with 10⁷ CFU/coupon and stored up to 30 days. In comparison with Staphylococcus aureus and Salmonella Typhimurium, L. monocytogenes demonstrated the highest survivability where about 3 log CFU/coupon remained at the end of the experimental period. While survival during the early storage period was markedly affected by both food-component attachment and food type, a long dehydration period diminished the effect of those.     

Grazing exit electron probe microanalysis of submicrometer inclusions in metallic materials

Grazing exit electron probe microanalysis (GE-EPMA) is a new method of EPMA in which characteristic X-rays emitted from only near-surface regions of a specimen are detected at extremely low exit angles near 0 degrees (the grazing exit condition). This technique requires the analytical objects exist on a flat surface. Therefore, the GE-EPMA analysis has been used only for the analysis of particles or a thin film on a flat substrate so that there were only few applications for practical analysis. As a new application, we have carried out GE-EPMA analysis of approximately 0.2-microm inclusions on stainless steel, which appeared to be a projection on the specimen surface with chemical etching. The GE-EPMA quantitative results were in excellent agreement with those of inclusions that were extracted from the stainless steel and analyzed by EPMA with conventional exit condition (30 degrees). This method could be, therefore, applied to the analysis of the submicrometer inclusion in a wide variety of metallic materials if the inclusion appears to be a projection with chemical etching treatment.     

Single-crystal growth and anisotropic electrical properties of (La1?xCax)2CaCu2O6

Large single crystals of (La_1–x Ca _x )₂CaCu₂O₆ were synthesized by the travelling solvent floating zone (TSFZ) technique. The dimension of the grown boules was typically 4 mm×30 mm long with thec-axis perpendicular to the growth direction. After oxygen loading at 1080°C in 400 atm of O₂, they became superconductive with a sharp transition at around 50 K. The resistivity was metallic both along thec-axis and within theab-plane, with an anisotropy ratio of ²( _c/ _ab ) 50 which is almost independent of temperature. Details of the crystal growth, heat treatment procedures, and the results of electrical and magnetic property measurements are presented.     

Preparation of rod-shaped BaTiO3 powder

Rod-shaped BaTiO₃ powder particles have been prepared from rod-shaped TiO₂ ·nH₂O and BaCO₃ in molten chloride. The morphology of BaTiO₃ particles was studied referring to the effects of the chemical species of the starting titanium compound, amount of chloride, particle size of the titanium compound and reaction conditions, and the preparation condition of rod-shaped BaTiO₃ has been determined: i.e., large TiO₂ ·nH₂O particles were heated at 700°C in molten salt with an equal amount of BaTiO₃. This condition was effective in suppressing the formation of BaTiO₃ by a solution-precipitation process as well as the deformation of either TiO₂ ·nH₂O or BaTiO₃, which are responsible for the formation of equiaxed BaTiO₃ particles. The obtained rod-shaped BaTiO₃ particles had a cubic symmetry. Electron diffraction analysis showed that the following topotactic relation is retained; 0 1 0_{potassium tetratitanate} 0 1 0_{hydrated titania} 1 0 0_anatase 1 0 0_{barium titanate}