Graphite-epoxy laminates with almost null coefficient of thermal expansion under a wide range of temperature

A lamination tailoring technique is proposed in order to control a coefficient of thermal expansion of graphite-epoxy composites in a principal direction. This technique consists of two concepts of the thermoelastic invariants and the lamination parameters. The expansion free condition yields to a parabola in the feasible region of the lamination parameters. The calculated curves for a wide range of temperatures intersect almost at a point. A laminate with the lay-up construction corresponding to this point will exhibit an approximately null coefficient of thermal expansion in one direction in that temperature range. Some preliminary experimental results indicate that the present procedure is possible and promising. The tailored material will be appropriate for the space station structure.     

Photocatalyzed mineralization of a trimethylated phenol in oxygenated aqueous titania. An alternative to microbial degradation

The most methylated phenolic substrate in coal tar creosote, 2,3,5-trimethylphenol (TMP), was mineralized photocatalytically to CO₂ and water at pH 3 in illuminated air-equilibrated titania dispersions. Trimethylhydroquinone and trimethylbenzoquinone were the two major aromatic intermediates; trace amounts of trimethylcatechol also formed. Complete mineralization was achieved in oxygenated solutions in ～1 h; conversion of TMP was over in less than ～25 min in aerated solutions and in less than 12 min in oxygenated solutions.     

Detection of Listeria monocytogenes in humans, animals and foods

The Listeria monocytogenes-carrying rates were 100% for listeriosis patients and 1.3% for healthy humans. The L. monocytogenes contamination rates for retail sliced beef (34.2%) and pork (36.4%) were significantly higher (p < 0.05) than those for cattle (2.0%) and pigs (0.8%) and for cattle (4.9%) and swine (7.4%) carcasses. The percentages of serotypes 1/2a, 1/2b and 4b which are most dominant in human patients were high in isolates from fresh (90.0%) and processed (100%) fish and shellfish and imported natural cheese (96.7%).     

Primary small cell carcinoma of the larynx

Small cell carcinoma is a rare tumor of the larynx. We present such a case in a 78-year-old female. The histopathological diagnosis at the time of laryngomicroscopic biopsy was squamous cell carcinoma, upon which basis we initially chose surgical treatment. The surgical specimen, however, revealed small cell carcinoma. Despite the administration of radiotherapy and chemotherapy, the patient died 9 months after initial presentation. We believe that this case illustrates the need for a sufficiently large biopsy specimen in order to arrive at the correct histopathological diagnosis when small cell carcinoma of the larynx is present, and that immunohistochemistry and electron microscopy should be performed to aid the diagnosis.     

Genetic algorithms for flowshop scheduling problems

In this paper, we apply a genetic algorithm to flowshop scheduling problems and examine two hybridizations of the genetic algorithm with other search algorithms. First we examine various genetic operators to design a genetic algorithm for the flowshop scheduling problem with an objective of minimizing the makespan. By computer simulations, we show that the two-point crossover and the shift change mutation are effective for this problem. Next we compare the genetic algorithm with other search algorithms such as local search, taboo search and simulated annealing. Computer simulations show that the genetic algorithm is a bit inferior to the others. In order to improve the performance of the genetic algorithm, we examine the hybridization of the genetic algorithms. We show two hybrid genetic algorithms: genetic local search and genetic simulated annealing. Their high performance is demonstrated by computer simulations.     

Statistical analysis of oropharyngeal squamous cell carcinoma--multivariate analysis of prognostic factors and evaluation of therapeutic modalities]

Ninety-one cases of oropharyngeal squamous cell carcinoma initially treated at Keio University Hospital between July 1981 and June 1996 were reviewed retrospectively. There were 83 males and 8 females, aged from 29 to 83 years old, with an average age of 62.7. The primary lesion was located in the lateral wall in 52 patients (57.1%), the superior wall in 23 (25.3%), the anterior wall in 14 (15.4%) and the posterior wall in 2 (2.2%). Double cancer was detected in 21 patients (23.1%). The patients were divided into two groups according to the initial main treatment of the primary lesion without regard to chemotherapy: 72 patients (79.1%) who received curative radiotherapy with or without salvage surgery, and 14 patients (15.4%) who underwent curative surgery with or without preoperative and/or postoperative radiation. The remaining 5 patients were treated by chemotherapy alone. Prior to the above treatments 50 patients (54.9%) received neoadjuvant chemotherapy (NAC). Survival distributions were estimated by the Kaplan-Meier method as univariate analysis, and compared by the generalized Wilcoxon test. The overall five-year cumulative survival rate was 55.6%. The five-year survival rates according to stage (UICC classification, 1987) were as follows: stage I (11 cases), 70.7%; stage II (12 cases), 63. 6%; stage III (30 cases), 52.3%; and stage IV (38 cases), 52.5%. Significant clinicopathological variables that influenced survival were: (1) T stage (p = 0.0075); (2) age (p = 0.0274); and (3) location of primary lesion (p = 0.0400). The results of multivariate analysis by Cox's proportional hazards model identified T stage as a significant independent prognostic factor. Evaluation of the therapeutic modalities led to the following conclusions. (1) Differences in the initial treatments of the primary lesion were not reflected in the outcome. (2) Salvage surgery for residual or recurrent tumor contributed to improving the survival. The superior wall type, in particular, seemed to be a good indication for salvage surgery. (3) Although the limitations of radiotherapy are not defined clearly, we have to determine the indications for radical resection of tumors resistant to radiotherapy with reconstruction. (4) The response rate of NAC reached 85.4%, but there were no significant differences in survival between the group that underwent NAC and the other group in any other subset analyses. (5) Among the patients who underwent NAC, the responder (CR + PR) group showed a better five-year survival rate (61.3%) than the non-responder (NC + PD) group (42.9%), but the difference was not significant.     

Design of an adaptive observer for sensorless vector control of induction machines under regenerating conditions

The objective of this investigation is to stabilize a sensorless vector control system of induction motors by means of an adaptive observer in regenerating mode at very low speed. The adaptive observer gain is designed by means of the Routh–Hurwitz criterion. It is verified by simulation and experiment that the proposed system is stable. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(4): 78–87, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10202     

Lattice Constants and Compositions of Manganese-Bearing Ferrites

When manganese-bearing ferrites (Mn _x Fe_{3- x} O_4-delta, with x = 0.17-1.09) were prepared in the present study via a solid-state reaction, manganese ions were incorporated into the lattice sites of the ferrites in the divalent state. The lattice constant ( a ₀) of those ferrites increased linearly as the manganese composition x increased. A ferrite with x = 1.28 contained manganese ions with a valence state higher than 3+; however, no further increase in a ₀ occurred at valences higher than 2+.     

Fibrous support for immobilization of enzymes. II

A series of adsorption experiments was conducted with varying initial enzyme concentrations. The observed values are compared with the results calculated from the adsorption equations based on Langmuir adsorption mechanism. The values of three parameters, adsorption equilibrium constant K_a, maximum value of adsorbed enzyme per unit mass of SFF, N, and forward adsorption rate constant k_a, were determined from Langmuir adsorption equations and experimental data. In the initial enzyme concentration range below 100 (mg enz./dL), the simulated enzyme concentration vs. time curve agreed well with observed values. However, it was found that the adsorption in the higher concentration range was slow, and the corrected forward adsorption rate constant should be employed.