ELID precision grinding of large special Schmidt plate for fibre multi-object spectrograph for 8.2 m Subaru telescope

To explore various scientific frontiers from nearby substellar objects to large scale structures of the high redshift universe, a Fibre Multi-Object Spectrograph (FMOS) is being developed as the second generation near-infrared measuring instrument for the prime focus of 8.2 m Subaru telescope in Hawaii, which employs a large special Schmidt plate element. The Schmidt plate consists of a large non-axisymmetric aspherical concave plate and a convex plate. This paper introduces its manufacturing process, focusing on its non-axisymmetric aspherical surface machining by utilizing synthetically ELID grinding and arc-enveloped grinding method. A new grinding system capable of fabricating large optical elements was developed with 10 nm resolution. In this ELID arc-enveloped grinding system, a Cast Iron Fibre Bonded (CIFB) diamond wheel was 3D controlled to scan the workpiece to generate required surface. Grinding characteristics such as attainable form accuracy, surface roughness were investigated. Furthermore, some measures to improve form accuracy were discussed and verified.     

Thermal cycle behavior of plasma sprayed La2O3, Y2O3 stabilized ZrO2 coatings

The effects of La₂O₃ addition on thermal conductivity, phase stability and thermal cycle life of Y₂O₃ stabilized ZrO₂ plasma sprayed coatings were investigated. Although low thermal conductivity as well as high resistance to sintering was achieved by La₂O₃ addition, it tended to also result in lower phase stability and thermal cycle life of the coatings. Optimization of the composition and structure of the coatings improved these properties, and the optimized coatings showed prolonged thermal cycle life.     

Biodegradable polymers based on renewable resources VIII. Environmental and enzymatic degradability of copolycarbonates containing 1,4 : 3,6‐dianhydrohexitols

Environmental and enzymatic degradations were investigated on a series of copolycarbonates consisting of equimolar amounts of 1,4 : 3,6‐dianhydrohexitols (1,4 : 3,6‐dianhydro‐D ‐glucitol (1a) and 1,4 : 3,6‐dianhydro‐D ‐mannitol (1b)) and alkylene diols (1,4‐butanediol, 1,6‐hexanediol, 1,8‐octanediol, and 1,10‐decanediol) or oligo(ethylene glycol)s (di‐, tri‐, and tetraethylene glycols). Fourteen different copolycarbonates with number average molecular weights in the range of 1.1–4.2 × 10⁴ were prepared by solution polycondensation as described in our previous article. Biodegradability of the copolycarbonates was assessed by soil burial degradation tests in composted soil at 27 °C and by enzymatic degradation tests in a phosphate buffer solution at 37 °C. In general, biodegradability of the copolycarbonates increased with increasing chain lengths of the methylene groups of alkylene diols or of the oxyethylene groups of the oligo(ethylene glycol)s. SEM observations of the film surfaces of polymers recovered from soil burial indicated that the copolycarbonates were degraded by microorganisms in soil. In enzymatic degradation, the copolycarbonates containing alkylene diol components showed high degradability with Pseudomonas sp. lipase, whereas the copolycarbonates containing oligo(ethylene glycol) components were not degraded at all. The enzymatic degradability of the copolycarbonates is discussed with reference to the geometrical structure around the carbonate linkages and the microstructure and hydrophobicity of the polymer chains. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1679–1687, 2005     

Thermal conductivity and thermal cycle life of La2O3 and HfO2 doped ZrO2-Y2O3 coatings produced by EB-PVD

The effects of La₂O₃ and HfO₂ addition on thermal conductivity and thermal cycle life of EB-PVD YSZ coatings were investigated. La₂O₃ and HfO₂ were selected as additives, because they significantly suppress the sintering of YSZ. The developed coating showed low thermal conductivity as well as high resistance to sintering. Burner rig tests confirmed that the developed coating have a superior thermal insulating effect and have a longer life than that of a coating with conventional composition.     

Noise Characteristics of Centrifugal Blower with Low Solidity Cascade Diffuser （Noise Reduction by means of Small Groove Located at LSD Blade Leading Tip）

This paper deals with the effect of the blade tip-groove of the low solidity cascade diffuser (LSD) on the blower characteristic and the noise generated by the LSD. The small grooves were set up at the root and/or tip near the leading edge of the LSD blade. In order to clarify the mechanism of noise increase due to LSD and also to reduce the noise, the relationships between the noise increase based on the LSD, the LSD performance and the secondary flow formed additionally by the tip-groove were investigated experimentally as well as numerically, especially analyzing flow behaviors in the LSD in view points of flow separation on the suction surface of the LSD blade and the secondary flow on the side walls. By reducing the stagnation region smaller near the root and/or tip of the LSD blade leading edge, the secondary flow behavior changes remarkably around the LSD blade, as a result, the noise level and the blower characteristics vary. It can be concluded that, by means of a small tip-groove located only at the shroud side near the LSD blade leading edge, the noise generated by the LSD can be reduced without deteriorations of the LSD performance and the blower characteristics as well.     

Biodegradable polymers based on renewable resources. V. Synthesis and biodegradation behavior of poly(ester amide)s composed of 1,4:3,6‐dianhydro‐D‐glucitol, α‐amino acid,and aliphatic dicarboxylic acid units

A series of poly(ester amide)s were synthesized by solution polycondensations of various combinations of p‐toluenesulfonic acid salts of O,O′‐bis(α‐aminoacyl)‐1,4:3,6‐dianhydro‐D ‐glucitol and bis(p‐nitrophenyl) esters of aliphatic dicarboxylic acids with the methylene chain lengths of 4–10. The p‐toluenesulfonic acid salts were obtained by the reactions of 1,4:3,6‐dianhydro‐D ‐glucitol with alanine, glycine, and glycylglycine, respectively, in the presence of p‐toluenesulfonic acid. The polycondensations were carried out in N‐methylpyrrolidone at 40°C in the presence of triethylamine, giving poly(ester amide)s having number‐average molecular weights up to 3.8 × 10⁴. Their structures were confirmed by FTIR, ¹H‐NMR, and ¹³C‐NMR spectroscopy. Most of these poly(ester amide)s are amorphous, except those containing sebacic acid and glycine or glycylglycine units, which are semicrystalline. All these poly(ester amide)s are soluble in a variety of polar solvents such as dimethyl sulfoxide, N,N‐dimethylformamide, 2,2,2‐trifluoroethanol, m‐cresol, pyridine, and trifluoroacetic acid. Soil burial degradation tests, BOD measurements in an activated sludge, and enzymatic degradation tests using Porcine pancreas lipase and papain indicated that these poly(ester amide)s are biodegradable, and that their biodegradability markedly depends on the molecular structure. The poly(ester amide)s were, in general, degraded more slowly than the corresponding polyesters having the same aliphatic dicarboxylic acid units, both in composted soil and in an activated sludge. In the enzymatic degradation, some poly(ester amide)s containing dicarboxylic acid components with shorter methylene chain lengths were degraded more readily than the corresponding polyesters with Porcine pancreas lipase, whereas most of the poly(ester amide)s were degraded more rapidly than the corresponding polyesters with papain. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2721–2734, 2001     

Long-term prognostic value of PCNA labeling index in primary operable breast cancer

Cell proliferation was evaluated in 167 tissue specimens obtained from primary breast cancer patients who had undergone radical surgery between 1984 and 1988. Formalin-fixed and paraffin-embedded tissue specimens were used in the immunohistochemical study. The immunohistochemical method was carried out using the avidin-biotin immunoperoxidase technique, and anti-proliferating cell nuclear antigen (PCNA) monoclonal antibody was used for primary antibody. Based upon the PCNA labeling index (LI), the patients were divided into two groups: low PCNA, <25% and high PCNA, >/= 25%. The PCNA LI ranged from 1% to 76% (mean, 23.9%). Patients aged 50 years. There was no relationship between the PCNA LI and tumor size, lymph node involvement and hormone receptors. The survival curves of 146 invasive breast cancer patients showed that the high PCNA group had poor overall survival compared with the low PCNA group. A significant difference in the overall survival between the high and low PCNA groups was observed in lymph node-positive patients, however, no significant difference was found between the two groups in lymph node-negative patients. PCNA LI was identified as an independent predictor in primary breast cancer patients.     

Velocity and Size of Droplets in Dense Region of Diesel Fuel Spray on Transient Needle Opening Condition

In order to investigate the effect of transient needle opening on early stage of spray behavior, simultaneous measurements of velocity and size of droplet were conducted by a newly developed laser 2-focus velocimeter (L2F). The micro-scale probe of the L2F was consisted of two foci with a distance of 36 μm. The tested nozzle had a single hole with a diameter of 0.2 mm. The measurements of injection pressure, needle lift, and crank angle were synchronized with the spray measurement by the L2F at the position 10 mm downstream from the nozzle exit. It has been clearly shown that the velocity and size of droplet increase with needle valve opening and that the probability density distribution of droplet size can be fitted to the Nukiyama-Tanasawa distribution under the transient needle opening condition.     

Fabrication of a Composite Varistor with Electrical Conductive Ni Filler and Electrostriction PNZST Matrix

A composite varistor was fabricated using Ni powder as conductive filler and PNZST antiferroelectric powder as electrostriction matrix. The composite is an electrical insulating material when an electrical field is not applied. When the electrical field was applied to the composite, the PNZST powder matrix was distorted. A conduction path was formed in the composite because of the distortion of the electrostriction matrix and thus the composite became a conductive material when the electrical field was applied. Composites using an Ni filler with 4-μm particle size and a PNZST matrix with 2-μm particle size showed a varistor property with volume fractions 33% and 37%; the nonlinearity coefficients of the composites were 3.85 and 3.82. The composites using an Ni filler with 40-μm particle size and a PNZST matrix with 2-μm particle size also showed varistor properties with volume fractions 50% and 53%, and nonlinearity coefficients of the composites were 3.65 and 3.12.