Thermal stress measurement in steel plate strengthened by CFRP and aluminum alloy plates

In steel members strengthened by carbon-fiber reinforced polymer (CFRP) plates, the thermal stresses are introduced in the steel members, the CFRP plates and the adhesive layers when temperature changes because the linear thermal expansion coefficients of steel and CFRP are mismatched. As so far, the authors proposed a technique to reduce the thermal stress in steel members strengthened by CFRP plates, which involves bonding aluminum alloy plates with CFRP plates. In the proposed method, the thermal stress in steel member can be reduced so that there are negligible levels of stress in steel member when the cross sectional areas of CFRP and aluminum plates are designed to correspond to the coefficient of thermal expansion of steel, even though the thermal stresses are introduced in the CFRP and aluminum plates. In this study, to confirm the maintaining the thermal stress reduction in steel member by proposed method, thermal stress measurement in steel plate strengthened by CFRP and aluminum plates was carried out about 21 months. In this research, the thermal stress introduced in the steel plate strengthened by CFRP plates was also measured. Furthermore, to assume the thermal shear and normal (peel) stresses in adhesive layers, FE analysis with plane stress element was employed. As the result, it was shown the thermal stresses in steel plate with CFRP plate were able to calculate by using composite theory and measured temperature. Furthermore, in steel plate strengthened by CFRP and aluminum plates, the thermal stress introduced in steel plate was negligible-small through the all-season. It was found the thermal stresses in steel plate with CFRP plates as well as CFRP and aluminum plates were also estimated by using composite theory and measured temperature. In the steel plate strengthened by CFRP and aluminum plates, the thermal shear and normal stresses in adhesive layer glued to steel plate become smaller than that in the conventional CFRP bonded specimen. However, the shear stress in adhesive layers between CFRP and aluminum plates in proposed method was higher than the thermal stress in adhesive layers between CFRP plates in conventional method.     

Low-temperature sintering of ZrW2O8–SiO2 by spark plasma sintering

Amorphous ZrW₂O₈ powder and amorphous SiO₂ powder were prepared by a sol–gel process as raw materials, and high-density ZrW₂O₈–SiO₂ were successfully prepared at a much lower temperature of 923 K for a much shorter holding time of 10 min by spark plasma sintering (SPS) method rather than by conventional melt-quenching method. The relative densities of 0.85ZrW₂O₈–0.15SiO₂ and 0.70ZrW₂O₈–0.30SiO₂ were 99.4% and 96.6%, respectively. The combined technique of a sol–gel process and SPS should enable us to prepare the varied types of high-density composites of ZrW₂O₈ without severe thermal cracking caused by melt-quenching. The thermal expansion properties and dielectric properties of ZrW₂O₈–SiO₂ were also investigated.     

Phonon anomalies in YNi2 11B2C

Recently we have discovered a new peak with phonon character which appears only below T_c in an intermetallic superconductor, YNi₂ ¹¹B₂C (Tc14-2K) by neutron inelastic scattering measurements. The peak intensity of the new peak shows the order-parameter-like temperature dependence of the superconductivity. The new peak grows by absorbing the spectral weight from the above-lying soft phonon mode. In the present study we investigate the magnetic field dependence of the new peak. With increasing magnetic field, the new peak is gradually suppressed and disappears by H=H_c2 (4.7T at T=5.5K). Beyond H_c2, the profile of the scattering function recovers that of the non-superconducting state above T_c These results strongly indicate that this new peak is undoubtedly associated with the superconducting state in YNi₂ ¹¹B₂C.     

Wide bandwidth of over 50 GHz travelling-wave electrodeelectroabsorption modulator integrated DFB lasers

A travelling-wave electrode electroabsorption modulator integrated distributed feedback laser to overcome the CR-induced bandwidth limitation is developed. A bandwidth much wider than 50 GHz is achieved. A 40 Gbit/s eye-diagram is observed. The device has a potentiality for future 100 Gbit/s transmission     

1330 V, 67 m/spl Omega//spl middot/cm/sup 2/ 4H-SiC(0001) RESURF MOSFET

Design and fabrication of 4H-SiC(0001) lateral MOSFETs with a two-zone reduced surface field structure have been investigated. The dose dependencies of experimental breakdown voltage show good agreement with simulation. Through the optimization of implant dose, high-temperature (1700/spl deg/C) annealing after ion implantation, and reduction of channel length, a breakdown voltage of 1330 V and a low on-resistance of 67 m/spl Omega//spl middot/cm/sup 2/ have been obtained. The figure-of-merit (V/sub B//sup 2//R/sub on/) of the present device reaches 26 MW/cm/sup 2/, being the best performance among lateral MOSFETs reported. The temperature dependence of static characteristics is also presented.     

Allogeneic peripheral blood stem cell transplantation in 30 patients with hematologic disorders

Thirty patients (median age of 32 years; range, 6-61) with hematologic disorders received unmanipulated peripheral blood stem cell transplants from HLA-matched or one-antigen-mismatched related donors following myeloablative therapy for acute lymphoblastic leukemia (7), acute myelogenous leukemia (6), chronic myelogenous leukemia (8), myelodysplastic syndrome (3), or other disorders (6). Granulocyte colony stimulating factor (G-CSF) mobilized peripheral blood stem cells were collected from donors in 1 to 3 aphereses. The apheresis products contained mean counts of 11.3 x 10(8) (range, 3.8-17.2) nucleated cells/kg and 6.7 x 10(6) (range, 1.3-16.7) CD34+ cells/kg. Graft-versus-host-disease (GVHD) prophylaxis consisted of cyclosporin A plus methotrexate, or FK506 plus methotrexate. All patients received G-CSF following their transplant. Although 1 patient died of pneumonia 6 days after transplantation, the others demonstrated rapid engraftment. Median days to recovery to 500/microliter neutrophils and 20,000/microliter platelets were 13 (range, 8-21) and 14 (range, 1-23) days, respectively. The incidence of acute GVHD grade II-IV was 33%; chronic GVHD developed in 57% of the assessable patients. There were no episodes of graft failure or rejection. Nineteen patients (63%) were alive and in complete remission from 147 to 839 days following their transplant (median follow-up of 560 days). Further follow-up study will be required to assess the incidence of chronic GVHD and graft-versus-leukemia (GVL) effects.     

Evaluation of the PyloriTek test for detection of Helicobacter pylori infection in cases with and without eradication therapy

OBJECTIVE: The accuracy of the PyloriTek test (a 1-h rapid urease test) used after eradication therapy of Helicobacter pylori (H. pylori) has not been well clarified. This study was done to evaluate the accuracy of the PyloriTek test results for cases with and without eradication therapy, using culture and histology as gold standard methods, and to establish the suitable timing of the PyloriTek test after eradication treatment. METHODS: One hundred sixty-three patients undergoing upper endoscopy were randomly selected; 100 patients had not received eradication therapy and 63 had. Three biopsy specimens each were obtained from the gastric antrum and the body for examination by PyloriTek, culture, and histology. The absence of H. pylori was established with negative results from both culture and histology. RESULTS: In cases without eradication therapy, PyloriTek, correctly identified 66 of 67 H. pylori-positive cases and 30 of 33 H. pylori-negative cases, yielding 98.5% sensitivity and 90.9% specificity. In cases with eradication therapy, PyloriTek gave correct diagnoses in 10 of 17 H. pylori-positive cases and in 45 of 46 H. pylori-negative cases, for 58.8% sensitivity and 97.8% specificity. However, when PyloriTek was used more than 4 months after the end of eradication therapy, both the sensitivity and the specificity increased to 100%. CONCLUSION: Considering time and cost, the use of PyloriTek alone may be satisfactory for detecting H. pylori infection in cases without eradication therapy. When patients are examined more than 4 months after intervention, the use of PyloriTek alone may be sufficient for correctly diagnosing H. pylori infections.     

Chronic Beryllium disease after exposure to low-beryllium-content copper

A 24-year-old man was admitted to our hospital because of exertional dyspnea and abnormal shadows on chest X-ray film. He worked in a factory, where he was exposed to 1.8% beryllium-copper alloys. His job was to draw out heated beryllium-copper wire to make it more fine. Chest X-ray film and chest CT scan showed left-sided pneumothorax, diffuse fine reticulonodular shadows, and several cysts. Pulmonary-function tests showed a restrictive disorder and a low diffusing capacity. A specimen obtained by open-lung biopsy showed epithelioid cell granuloma and alveolitis, which were compatible with chronic beryllium disease. The beryllium content of the lung tissue was 0.045 microgram/gram. Beryllium lymphocyte transformation tests on blood and on bronchoalveolar lavage fluid were positive. Based on these findings, chronic beryllium disease was diagnosed. After treatment with 1 mg/kg of prednisolone daily, dyspnea disappeared. Then the dose was tapered slowly. In Japan, chronic beryllium disease is extremely rare, and to our knowledge only 22 other cases have been reported.     

Sulfated glycoconjugates demonstrated in combination with high iron diamine thiocarbohydrazide-silver proteinate and silver acetate physical development.

Sulfated glycoconjugates in epithelial cells and mesenchymal cells were investigated after staining with high iron diamine-thiocarbohydrazide-silver proteinate. One purpose of the experiment was to apply a new physical developed to the staining. Instead of silver nitrate, silver lactate or silver bromide, we used silver acetate as an ion donor. This new method allowed physical development under normal lighting conditions, and resulted in the reduction of background staining even after amplification. As the developer did not contain gum arabic, troublesome treatment was not necessary. The time required for staining was very short and the electron density of the final reaction product was high and easily identifiable under the electron microscope. Fixing was not necessary. Very small amounts of reactive substance were detectable after physical development. This developmental procedure has been applied to both the preembedding staining and postembedding staining of sulfated glycoconjugates. The results obtained using this method are presented.     

Chirping characteristic and frequency response of MQW opticalintensity modulator

The spectral linewidth enhancement factor and frequency responses of electro-absorption-type optical-intensity modulators, especially InGaAs/InAlAs MQW modulators, are described. A method of exactly estimating the value of the α factor is presented under the nonlinearity of extinction-ratio characteristics. For measuring the frequency response of modulators, the sideband strength of the modulated output light with an optical spectrum analyzer, is analytically compared with the microwave power of photodiode direct detection with an electrical spectrum analyzer