The laminate-bending process for long fiber-reinforced plastics

In order to form long fiber-reinforced plastic sheets into angled parts, a new process called the Laminate-Bending Process was recently developed. The process consists of preforming a prepreg into semi-cured stable shapes having various sharp bending radii, followed by laminating the preforms into a fully cured thick angle product having high strength and rigidity. A sharp 90°V-angled product of five lay-ups of preform was test fabricated under various preforming and laminating conditions by using a continuous glass fiber reinforced epoxy resin, and it was confirmed to be excellent in delamination resistance and specific strength. Also, the process is quite practical in productivity, handling, and applicability to other advanced composite materials, and it can expand the use of such brittle materials for wider applications.     

Bainitelike transformations in some oxide ceramics

The authors show two examples of “bainitelike” transformations in some oxide ceramics. A bainitelike transformation means that a shear (martensitic) mechanism is controlled by, or together with, ionic diffusion in the lattice as well as the case of lower bainite in steel. The first example is a tetragonal-to-monoclinic transformation in ZrO₂-Y₂O₃ ceramics, where the bainitelike transformation must be characterized by (1) the increase in concentration of oxygen vacancies caused by the substitution of Zr⁴⁺ ions by Y³⁺ ions, (2) a fairly high mobility of oxygen ions through their vacancies, and (3) the formation of clusters composed of oxygen vacancies and oxygen ions. The second case is an inverse spinel to corundum structural change observed in γ Fe₂O₃ to α Fe₂O₃, in which the bainitelike transformation may be explained by cooperative movements of oxygen and ferric ions, which are sandwiched between oxygen layers. This article is based on a presentation made at the Pacific Rim Conference on the “Roles of Shear and Diffusion in the Formation of Plate-Shaped Transformation Products,” held December 18-22, 1992, in Kona, Hawaii, under the auspices of ASM INTERNATIONAL’S Phase Transformations Committee.     

A tobacco protein kinase, NPK2, has a domain homologous to a domain found in activators of mitogen-activated protein kinases (MAPKKs)

A cDNA (cNPK2) that encodes a protein of 518 amino acids was isolated from a library prepared from poly(A)+ RNAs of tobacco cells in suspension culture. The N-terminal half of the predicted NPK2 protein is similar in amino acid sequence to the catalytic domains of kinases that activate mitogen-activated protein kinases (designated here MAPKKs) from various animals and to those of yeast homologs of MAPKKs. The N-terminal domain of NPK2 was produced as a fusion protein in Escherichia coli, and the purified fusion protein was found to be capable of autophosphorylation of threonine and serine residues. These results indicate that the N-terminal domain of NPK2 has activity of a serine/threonine protein kinase. Southern blot analysis showed that genomic DNAs from various plant species, including Arabidopsis thaliana and sweet potato, hybridized strongly with cNPK2, indicating that these plants also have genes that are closely related to the gene for NPK2. The structural similarity between the catalytic domain of NPK2 and those of MAPKKs and their homologs suggests that tobacco NPK2 corresponds to MAPKKs of other organisms. Given the existence of plant homologs of an MAP kinase and tobacco NPK1, which is structurally and functionally homologous to one of the activator kinases of yeast homologs of MAPKK (MAPKKKs), it seems likely that a signal transduction pathway mediated by a protein kinase cascade that is analogous to the MAP kinase cascades proposed in yeasts and animals, is also conserved in plants.     

Significant risk factors of recurrence in muscularis proprial carcinoma of the stomach

BACKGROUND/AIMS: The aim of this study is to elucidate significant risk factors of recurrence in muscularis proprial gastric cancer (MPGC). METHODOLOGY: Seventy-three patients who underwent curative gastrectomy for MPGC were divided into 14 patients with postoperative recurrence (Group 1) and 59 patients without recurrence (Group 2). A retrospective study of Group 1 compared the clinicopathological features with Group 2. RESULTS: There were no significant differences of age, gender and operative method including frequency of lymph node dissection between Group 1 and Group 2. Although tumor size, gastric location and histological type did not significantly differ between the two groups, the rate of Borrman type in Group 1 (71.4%) was significantly higher than in Group 2 (42.4%). Significant risk factors of recurrence in pathological findings were the presence of secondary lymph node metastasis or more, lymphatic and venous involvement. Median survival in Group 1 (28.8 months) was significantly worse than in Group 2 (59.0 months). The 1-year, 3-year, and 5-year survival rates between Group 1 versus Group 2 were 71.4% versus 98.3% (p<0.01), 28.6% versus 96.7% (p<0.01), and 7. 1% versus 95.0 (p<0.01), respectively. CONCLUSIONS: Prognosis of the postoperative recurrence in MPGC was very poor. More careful prophylactic treatment against recurrence of MPGC should therefore, be prescribed in patients with the aforementioned risk factors of recurrence.     

Special purpose computer system with highly parallel pipelines for flow visualization using holography technology

We have designed a PC cluster system with special purpose computer boards for visualization of fluid flow using digital holographic particle tracking velocimetry (DHPTV). In this board, there is a Field Programmable Gate Array (FPGA) chip in which is installed a pipeline for calculating the intensity of an object from a hologram by fast Fourier transform (FFT). This cluster system can create 1024 reconstructed images from a 1024×1024-grid hologram in 0.77 s. It is expected that this system will contribute to the analysis of fluid flow using DHPTV.     

Pool fires under atmosphere and ventilation in steady-state burning (part II)

Two pool fire tests for solvent burning were made to obtain the burning rate and the mass loss rate from burning pans under atmosphere and ventilation in a cell. From the data, burning parameters for the Spalding's modified model reported in Part I were determined in steady-state pool burning.Part I of this paper was published in the May 1987 issue ofFire Technology. Reference: Gunji Nishio and Satoru Machida, Pool Fires under Atmosphere and Ventilation in Steady-State Burning, Part II,Fire Technology, Vol. 23, No. 3, August 1987, pp. 186–197.