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.     

Methanol synthesis from carbon dioxide at atmospheric pressure over Cu/ZnO catalyst. Role of methoxide species formed on ZnO support

Methanol synthesis from CO₂ and H₂ was carried out over a Cu/ZnO catalyst (Cu/Zn = 3/7) at atmospheric pressure, and the surface species formed were analyzed by diffuse reflectance FT-IR spectroscopy and temperature programmed desorption method. Two types of formate species and zinc methoxide were formed in the course of the reaction. Zinc methoxide was readily hydrolyzed to methanol. H₂O formed through the reverse water gas shift reaction was suggested to be involved in the hydrolysis of zinc methoxide.     

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.     

Dietary Lipids Impacts on Healthy Ageing

Healthy ageing is gaining attention in the lipid nutrition field. As in vivo biomarkers of healthy ageing, we have evaluated the survival, learning/memory performance, and physical potencies in rodents fed a diet supplemented with high-linoleic acid (LNA, ω6) safflower oil or high-α-linolenic acid (ALA, ω3) perilla oil for long periods. The results suggested that perilla oil with a low ω6/ω3 ratio is beneficial for healthy ageing. In order to address this issue further, we determined the survival of stroke-prone SHR (SHRSP) rats fed a conventional rodent diet supplemented with 10% fat or oil. Survival was longer with ω3-rich oils compared with ω6-rich oils. However, some kinds of vegetable oils and hydrogenated oils shortened the survival of SHRSP rats to an unusual degree (ca. 40% compared with that of ω6-rich oil) that could not be accounted for by the fatty acid and phytosterol composition of the oils. The observed decrease in platelet counts was associated with pathological changes in the kidney and other organs. Dihydro-vitamin K1 is proposed as a likely candidate as a stroke-stimulating factor in hydrogenated oils. Thus, factors other than fatty acids (ω6/ω3 balance) and phytosterols must be taken into account when fats and oils are evaluated in relation to healthy ageing.     

Over-1000-channel ultradense WDM transmission with supercontinuum multicarrier source

In this paper, ultradense wavelength-division multiplexing (WDM) transmission technologies are discussed, and a field demonstration of over-1000-channel ultradense WDM transmission is reported. The generation of an ultradense WDM signal using a supercontinuum multicarrier source that generates more than 1000 carriers and uniform precise channel spacing of 6.25 GHz is presented. The influence of four-wave-mixing generated in the transmission fiber and the requirements placed on the WDM multiplexer and demultiplexer is described. An over-1000-channel ultradense WDM transmission experiment is reported. A 1046 /spl times/ 2.67-Gbit/s 6.25-GHz-spaced ultradense WDM signal is successfully transmitted over 126 km of field-installed fibers in the test bed of JGN II.     

Resolving the conflict of a simultaneously highly moisturizing and occlusive emulsion film

Two basic functions of emulsion-based cosmetic products are moisturization and occlusion, which are markedly affected by the ratio of hydrophilic to lipophilic parts in the emulsions. However, due to their conflicting requirements, it is difficult to simultaneously improve both functions. Therefore, we developed new emulsion that has simultaneously higher moisturizing and occlusive functions than those of polyoxyethelene-type emulsions, by using polyglycerin-type surfactants, acetyl alcohol, polyglycerin-13-polyoxybutylene-14-stearyl ether and the D-phase emulsification method, because of dispersing a large quantity of water into the lipophilic part of the applied emulsion film and of strengthening the hydrophilic part of the emulsion film. We confirmed through microscopic study with a laser microscope that in polyoxyethelene-type emulsions, droplets disappear quickly after the film is formed and dried, whereas in our experimental emulsions, the droplets' shape is evenly retained. Furthermore, after 1 month of continuous use, stratum corneum removal and corneocyte arrangement also improved significantly.     

A wind-tunnel study on diffusion from urban major roads

We evaluate the performance of reduced-scale wind-tunnel experiments that simulate vehicle-induced pollutant diffusion in urban roadside area. From Japanese urban areas, we selected four sites that cover a wide range of road structures, building density, and roadside features. At each site, four field stations were installed to monitor concentration of air pollutants including nitrogen oxides (NOx). In the wind-tunnel experiments, ethane was emitted from along the major roads, and its concentration was compared with the background-subtracted field values. For annual average of NOx in the year 2006, we found that an appropriately normalized concentration agreed fairly well between wind-tunnel and field measurements. The wind-tunnel concentration distribution measured at a high spatial resolution revealed that roadside features such as tall buildings, noise barriers, and trees have considerable effect on the concentration on the downwind or upwind side of the roads. The high-resolution results are expected to serve as a useful database for evaluating numerical air pollution models.