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.     

Absorber design for a compound parabolic concentrator collector without transmission loss

A new design method for a compound parabolic concentrator heat collector is described. The conventional design of the ideal compound parabolic concentrator collector has a touching point between a light absorber and the reflectors. This structure is not preferable from the standpoint of conductive heat leakage and thermal stress on reflector materials. On the other hand, if the absorber and the reflectors are separated from each other, the gap between them usually causes optical errors such as light transmission loss or an increase in the reflection number. We discuss the fact that ideal heat collection is possible, in spite of the gap, by introducing the idea of an effective heat concentration ratio.     

Homo- and copolymerizations of 3-(N-carbazolyl)-1-propyne and its homologues by Mo and W catalysts

Summary 3-(N-Carbazolyl)-1-propyne polymerized with MoCl₅- and WCl₆-based catalysts to produce a polymer in high yields. The MoCl₅ and MoCl₅-n-Bu₄Sn catalysts were the most effective (the systems solidified immediately after initiation of polymerization with these catalysts). The product polymer was a yellow solid insoluble in any solvent. Copolymerization of the present monomer with tert-butylacetylene by MoCl₅-n-Bu₄Sn produced a copolymer; it had a high molecular weight (M _w 350,000), completely dissolved in toluene, CHCl₃ etc, and formed a free-standing film by solution casting. -N-Carbazolyl-1-hexyne and-1-octyne produced toluene-insoluble polymers with WCl₆-Ph₄Sn.     

Significant reduction of medical costs by differentiation therapy with all-trans retinoic acid during remission induction of newly diagnosed patients with acute promyelocytic leukemia. The Japan Adult Leukemia Study Group

OBJECTIVE: For resuscitation of hemorrhagic hypovolemia, we compared the effectiveness of (1) isotonic lactated Ringer's solution (LRS), (2) 2400 mOsm of 7.5% NaCl:6% dextran 70 (HSD), and (3) 2400 mOsm of 7.9% sodium acetate:1.9% NaCl:6% dextran 70 (HAD). DESIGN: In six randomized, blinded experiments for each solution, conscious instrumented adult sheep were hemorrhaged by removing approximately 1.8 L (42 +/- 3 mL/kg) of blood, while maintaining the mean arterial pressure (MAP) at 50 mm Hg for 2 hours. METHODS: Test solutions were infused as needed to restore the cardiac index to baseline. RESULTS: Volume requirements with HAD (236 +/- 29 mL) and HSD (244 +/- 39 mL) were significantly less (p < 0.05) than LRS (3463 +/- 234 mL). Mean arterial pressure was normalized with HSD and LRS, but not with HAD, which resulted in MAPs of 20 to 25 mm Hg less than baseline resulting from a reduced peripheral resistance. Oxygen delivery, however, was significantly higher with HAD during the resuscitation period. Acid-base balance (pH) and oxygen consumption were normalized within 5 minutes of infusion only with HAD. CONCLUSIONS: Small-volume infusion with HAD resulting in "high-flow-low-pressure" resuscitation may offer unique hemodynamic and metabolic advantages for the initial treatment of hemorrhage from trauma.     

Experimental and clinical study on intraoperative local infusion chemotherapy (ILIC) for advanced gastric carcinoma

An intensive chemotherapy combined with surgery, termed "intraoperative local infusion chemotherapy (ILIC)", was devised. The ILIC procedure is to infuse 50 mg of cisplatin through the feeding artery to the tumor, which has been isolated from blood flow by clamping the stomach and blood vessels, before radical surgery. An experiment in dogs showed considerable free Pt transfer into thoracic lymph after ILIC. Sum total Pt in the thoracic lymph after ILIC (294.5 micrograms/3 h) was 4.3 times that after IV administration (68.3 micrograms/3 h). In ILIC, AUC of free Pt in the thoracic lymph was about 5.8 times that in peripheral blood. ILIC was applied in 24 advanced gastric cancer patients, consisting of 6, 2, 4 and 12 in pTNM stage II, IIIA, IIIB and IV, respectively. Pt concentration of the tissues was high in the tumor (23.22 micrograms/g) and the regional lymph nodes (2.95 micrograms/g) compared to that in the serum (0.45 microgram/ml). The survival rate (Kaplan-Meier) in the ILIC patients was significantly higher than that of control patients (matched pair method) from among patients treated by surgery alone. No fatal complications were encountered in any patient treated by ILIC.     

Threshold for Millimeter-Wave (60 GHz)-Induced Ocular Injury

Journal of Infrared, Millimeter, and Terahertz Waves - Millimeter waves (MMW) absorbed by skin or cornea may induce damage by heat. We have developed a 60&nbsp;GHz MMW exposure-induced eye...     

Single-mode optical waveguides fabricated from fluorinated polyimides

Buried channel optical waveguides were fabricated from fluorinated polyimides. They operated in single mode and showed an optical loss of less than 0.3 and 0.7 dB/cm for TE and TM polarizations, respectively, at a wavelength of 1.3 mum. Moreover, these waveguides had high heat and moisture resistance; the optical loss did not significantly change after heating at 380 degrees C for 1 h or after exposure to 85% relative humidity at 85 degrees C for over 200 h.     

High-temperature oxidation of Al-deposited stainless-steel foils

The oxidation resistance of Al-deposited Fe–Cr–Al foils containing small amounts of La and Ce was assessed by a cyclic oxidation test with temperature varying between room temperature and 1323 K to 1423 K in static air. (1) The Al content of Fe–Cr–Al–La, Ce foils can be increased by depositing an Al layer from the vapor phase. The deposition of a 1-m-thick Al layer on both sides of the 50-m-thick foil is equivalent to a 1.5 mass% increase in the Al content. The deposited Al diffuses into the foil during heat treatment. The uniform distribution of Al is obtained by heating at 1273 K for 18 ks. (2) After the initial transition stage the oxidation follows the parabolic law until breakaway sets in. The scale consists mainly of -Al₂O₃ during the parabolic period. (3) The increase in the Al content by more than 5 mass% by the Al-deposition remarkably improves high-temperature oxidation resistance (smaller parabolic rate constant and longer protection time). (4) The Al-deposited foils have better oxidation resistance than the conventional foils with the same contents of Al and rare-earth elements. This is attributable to the different nature of the initially formed oxide on the Al-deposited foil. (5) The so-called rare-earth element effect was also observed for the Al-deposited foils. Predominant diffusion of oxygen through the Al₂O₃ scale and vacancy-sink mechanism are applicable to the present results.     

Fracture toughness of eutectic Al-Si casting alloy with different microstructural features

The static fracture toughness of a series of eutectic Al-Si casting alloy with different microstructural features has been evaluated. The dominant influence of eutectic silicon in controlling the fracture toughness is thus clarified. The relationship between the fracture toughness and the microstructure was established. Fracture toughness was found to be strongly associated with the size and morphology of silicon particles. The other feature which greatly influences the fracture toughness is the ratio (/DE)_Si, i.e. the silicon particle spacing divided by the equivalent particle diameter, rather than the silicon particle spacing, _Si. Fracture toughness also correlates well with the void growth parameter, VGP (=_y (/DE)_Si), proposed by the authors. The results of the present work can be used to develop an understanding of the variation of fracture toughness with the microstructural features of eutectic Al-Si alloys.     

Anisotropy in the resistive superconducting transition under magnetic fields in single crystal Pb2Sr2Ho0.5Ca0.5Cu3O8

Anisotropie properties of the single crystal Pb₂Sr₂Ho_0.5Ca_0.5Cu₃O₈ have been investigated by measuring the electrical resistivity in theab-planeρ _ab (H, θ,T), which depends on the angleθ between theab-plane and the magnetic-field direction, in various constant fieldsH perpendicular to the current direction. All the angle-dependent values ofρ _ab (H, θ,T) at a constant temperature are scaled to be on one curve as a function of reduced field. The anisotropic parameter γ≡(m _c ^* /m _ab ^* )^1/2 is estimated as 12–13, which is larger than that of YBa₂Cu₃O₇ and much smaller than that of Bi₂Sr₂CaCu₂O₈. It has been concluded that the anisotropy does not always depend on the thickness of the blocking layer but seems to depend on the overlap of the electronic wave functions along thec-axis. Anisotropy in the pinning potential has also been discussed from the resistive tail in the temperature dependence ofρ _ab (H,θ,T).