Barium Titanate Ceramics with High Piezoelectricity Fabricated from Fibrous Particles

Barium titanate ceramics with high degrees of c-axis orientation were fabricated from fibrous particles. The maximum piezoelectric constant, d₃₃, obtained was ≅270 pC/N, which is much higher than values reported previously.     

Kidney transplantation and liaison psychiatry, part I: anxiety before, and the prevalence rate of psychiatric disorders before and after, transplantation

We examined psychiatric problems before and after kidney transplantation in a sample of 36 patients with end-stage renal failure. The prevalence rate of psychiatric disorders was 11.1% (4 of 36 cases) before the transplantation and 36.1% (13 of 36 cases) within 2 months after the transplantation. Except for a patient with schizophrenic disorder, no patients were found to have a psychiatric disorder from 2 to 6 months after the transplantation. In this study, we also examined anxieties and/or conflicts related to the transplantation using the synthetic house-tree-person (HTP) drawing test, a measure of mood states by means of a non-verbal expression method. The upper part of the tree trunk was not drawn in 25% of this sample (5 of 20 cases). In the HTP drawing tests immediately after the transplantation, however, trees missing the upper part of trunk were not drawn. Based on these findings, we discussed psychiatric problems in kidney transplantation.     

Studies on peroxidized lipids. VI. Fluorescent products derived from the reaction of primary amines,malonaldehyde and monofunctional aldehydes

Monofunctional aldehydes such as acetaldehyde,n-propylaldehyde,n-butylaldehyde,n-hexylaldehyde,n-heptylaldehyde and benzaldehyde affected the reaction between primary amines and malonaldehyde. While the reaction of primary amines and malonaldehyde at pH 7 produced fluorescent 4-methyl-1,4-dihydropyridine-3,5-dicarbaldehydesIa-f, the reaction of the primary amines, malonaldehyde and the aldehydes listed above gave fluorescent 4-substituted 1,4-dihydropyridine-3,5-dicarbaldehydesIIa-j. The primary amines used for this reaction included alkylamines, amino acids and alkanolamines. The optimal ratio of the amine, malonaldehyde and the aldehyde was 1:2:1–2, at which compoundsII were produced quantitatively. Peroxidized lipids which may contain malonaldehyde and other aldehydes could react with the primary amines to produce highly fluorescentII. Fluorescence spectra ofII showed excitation maxima at 386–403 nm and emission maxima at 444–465 nm in phosphate similar to those ofI. The spectra of these 1,4-dihydropyridinesI andII were roughly similar to those of lipofuscin pigment, but they exhibited different characteristics in acid and alkaline media from those of lipofuscin pigment. CompoundsII may be useful as model compounds to elucidate the chemical structure of lipofuscin pigment.     

Polymer optical fiber for near infrared use

Using the empirical simulation that we developed to estimate loss spectra of amorphous polymers, we predicted the intrinsic loss spectrum of fluorine-containing polyarylate (FPAr) that should have a small attenuation loss in the near infrared region. Loss of FPAr is smaller than that of poly (methyl methacrylate), which is a typical optical polymer used as a core material in polymer optical fiber (POF), above 720 nm. FPAr was synthesized by phase transfer catalyzed polycondensation of 2,2-bis (4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane with isophthaloyl dichloride. Its glass-transition temperature (T_g) by DSC is 163°C. This indicates that FPAr has higher heat resistance than polycarbonate (PC) by about 10°C. A film of 100μm thick has over 85% transmittance from 330 to 900 nm. Values from a tension test are similar to those of PC. As a result, FPAr is expected to be a good core polymer for POF, because of its high T_g, good transparency, and good flexibility. Next, the POF made of FPAr was fabricated by a melt-flow spinning method. It had larger attenuation loss than predicted. The difference from the simulation was extrinsic loss caused by the fabricating process. Therefore, when a more suitable fabricating process is developed, loss of FPAr-POF can be decreased, so that it will be applicable to optical communications in the near infrared region. © 1993 John Wiley & Sons, Inc.     

Partial trisomy for short arm of chromosome 5

The incidence of sudden death due to undiagnosed primary intracranial tumor is low in forensic autopsy. The cause of death in a 20-year-old male found dead in his dormitory room was glioblastoma multiforme in the left temporal lobe. The direct cause of death was hemorrhage in the tumor. Three nights before the discovery of his body, he had several episodes of vomiting and had been absent from work since that time. On discovery of the body, it was thought that he had been dead for about 2 days. About 4 months before his death, he consulted an eye doctor for "fatigue of the eyes" and 1 month thereafter he visited the neurosurgical department of a hospital complaining headache. A diagnosis of tension headache was made; the possibility of brain tumor appears not to have been considered. A causal relationship between head trauma and hemorrhage in the tumor was excluded based on the circumstantial evidence.     

Quantitative three-dimensional characterization of pearlite spheroidization

We investigated the pearlite spheroidization of a 0.8 mass% C–Fe steel under 700 °C static annealing conditions using a combination of computer-aided three-dimensional (3-D) tomography and electron back-scattered diffraction. The holes present in naturally grown cementite lamellae cause shape instability and induce shape evolution of the lamellar structure during spheroidization. 3-D visualization demonstrated that the intrinsic holes play an important role in the initiation and development of pearlite spheroidization. The hole coalescence and expansion causes the break-up up of large cementite lamellae into several long narrow ribbons. Furthermore, the growth mechanism of inter-hole coalescence is related to the ratio of half the inter-hole distance on a cementite lamella to the thickness of that lamella. The driving force for hole growth is either the difference in surface energy or the curvature between the hole edges and the adjacent flat surface of the lamella. The morphologies of cementite ribbons depend on the hole expansion position on cementite lamella, and can change their shape to cylinders or small spheres by Rayleigh’s perturbation process after prolonged spheroidization.     

Chaotic characteristics of local voidage fluctuation in a circulating fluidized bed

Local voidage fluctuations have been measured by using an optical transmittance probe at various axial and radial positions in a circulating fluidized bed riser with a 0.1 m i. d. and 10 m height. The chaotic time series analysis of the local voidage fluctuations has been adopted to characterize the nonlinear dynamics of the circulating fluidized bed riser. The variations of the correlation dimension and the Kolmogorov entropy of the voidage fluctuation were found to depend on the local time-average voidage. The axial and radial distributions of the correlation dimension and the Kolmogorov entropy were strongly affected by the solids flow structures (e.g. core-annulus flow) in various operating conditions. The correlation dimension of local voidage fluctuations increases along the riser, except the position near the distributor. Both, the correlation dimension and the Kolmogorov entropy of local voidage fluctuations near the wall, were found to be smaller than those at the center of the riser, independent of the solids circulation rate and the axial position.     

A new approach to cutting state monitoring in end-mill machining

A new cutting state monitoring approach is proposed for the real-time predicting of the machining trouble and the surface quality of the machined products. In this approach, the relationships among the mechanical model of cutting process and its corresponding time series model, the surface roughness of the machined workpiece are evaluated through theoretical analysis and experimental investigation. It is therefore revealed that there is the linear relationships among the AR parameter a₁, the stiffness k₃ of cutting model and surface roughness P_z, and consequently the cutting process state can be estimated by only monitoring time series parameter a₁ of vibration signal measured during machining operation. In particular, it was found that the variation in the surface roughness of P_z=3–5 μm can be fully monitored.