PVT measurements of liquid ethanol in the temperature range from 310 to 363 k at pressures up to 200 MPa

Density measurements in the compressed liquid phase for ethanol were performed with a metal-bellows variable volumometer for temperatures between 310 and 363 K at pressures from the vapor pressure to 200 MPa. The results cover the high-density region from 737 to 882 kg m_–3. The experimental uncertainties (total errors) of temperature, pressure, and density were estimated to be no greater than 3 mK, 0.1 %, and 0.1 %, respectively. Measurements of saturated liquid density at temperatures of 310, 340, and 360 K are also reported.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado, U.S.A.     

Optical-signal-processing device based on waveguide-type variable delay lines and optical gates

In this paper, an optical-signal-processing device mainly designed for time-slot switching is demonstrated. The device is composed of variable delay-line arrays fabricated by planar lightwave circuit technology and high-speed optical gates. The variable delay-line arrays consist of transversal-form or lattice-form optical circuits. The operating principle is based on serial-to-parallel conversion, adjustment of the delay time between the parallel signals, and the gating of the optical bits or packets in the optical region. The device does not require any interaction between lightwaves through optical nonlinear effects or filter banks for code matching. As an example of its operation, label-processing functions are demonstrated, specifically the label swapping of optical return-to-zero pulses. The merits of the proposed device are described and problems that must be solved are also discussed.     

Experimental study on pullout strength of anchor bolt with an embedment depth of 30 mm in concrete under high temperature

Many anchor bolts are used in nuclear-related facilities in order to fast some equipments and pipes. About these anchor bolts, the possibilities should exist in being exposed to high temperature due to accident. However, little information is available regarding the effects of high temperatures on the behavior of anchor bolts. To obtain basic experimental data and to examine the response of cast-in-place anchor bolts to high temperature exposure, pullout strength of an anchor bolt during heating and after heating was examined. The maximum temperature in this test is 500 °C and two different rate of heating were prepared. Tests results show that pullout strength decreases with increasing surface temperature. Regardless of different rate of heating in this experiment, identical ratio of pullout strength of anchor bolt was obtained when the same temperature of concrete surrounding the bolt head was applied.     

Recombinant human bone morphogenetic protein-2 stimulates osteoblast differentiation and suppresses matrix metalloproteinase-1 production in human bone cells isolated from mandibulae

Bone morphogenetic protein (BMP), a member of the transforming growth factor superfamily, is one of the most potent growth factors that stimulate osteoblast differentiation and bone formation. We investigated the effects of recombinant human BMP-2 (rhBMP-2) on osteoblast differentiation and matrix metalloproteinase-1 (MMP-1) production in human bone cells (HBC) isolated from mandibulae of 3 adult patients. rhBMP-2 at concentrations over 50 ng/ml significantly stimulated alkaline phosphatase activity and parathyroid hormone (PTH)-dependent 3', 5'-cyclic adenosine monophosphate accumulation, which are early markers of osteoblast differentiation, in HBCs. rhBMP-2 (500 ng/ml) also enhanced the level of PTH/PTH related-peptide receptor mRNA expression in HBCs. Although neither HBCs untreated nor treated with rhBMP-2 produced measurable amounts of osteocalcin, which is a marker of more mature osteoblasts, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] induced ostocalcin mRNA expression and its protein synthesis in these cells. rhBMP-2 inhibited 1,25(OH)2D3-induced osteocalcin synthesis in HBCs at both the mRNA and protein level. rhBMP-2 also significantly suppressed MMP-1 production and MMP-1 mRNA expression at concentrations over 500 ng/ml. These results suggest that rhBMP-2 exerts anabolic effects on human osteoblastic cells derived from mandibulae by stimulation of osteoblast differentiation and down-regulation of MMP-1 synthesis.     

Bias of an optical passive ring-resonator gyro caused by themisalignment of the polarization axis in the polarization-maintainingfiber resonator

An analysis is presented of the bias of an optical passive ring-resonator gyro caused by the misalignment of the polarization axis in the resonator formed by the polarization-maintaining fiber. A large bias takes place when the phase difference between the two polarization modes of the fiber is equal to the amount of 2π times an integer. It is clarified that the bias can be suppressed by setting the fiber polarizers at the lead portions of the resonator, which was a method proposed originally to reduce the bias in an ideal resonator without the misalignment     

Human immunodeficiency virus type 2 envelope glycoprotein binds to CD8 as well as to CD4 molecules on human T cells

We report here that human immunodeficiency virus type 2 (HIV-2) envelope glycoprotein (gp105), but not HIV-1 gp120, can bind to CD8 molecules as well as to CD4 molecules on human T cells. This phenomenon may lead to differences in the life cycles of HIV-1 and HIV-2, and it may be related to the differences in disease manifestations of HIV-1 and HIV-2 infection, including longer survival of HIV-2-infected patients.     

Method for adjusting lattice-form optical devices and its use in realising low-loss variable chromatic dispersion compensator

A novel method for tuning the phase shifts of lattice-form devices to realise desired characteristics is proposed. The method effectively utilises incoherent and coherent tunable light, respectively, to measure symmetrical and asymmetrical Mach-Zehnder interferometers. We applied the method to a silica lattice device and achieved a low-loss variable dispersion compensator for 40 Gbit/s transmission.     

All solid-state Cr:LiSAF laser

Many kinds of experiments about all solid-state Cr:LiSAF lasers have been reported. A tunable all solid-state cw laser having tunability over more than 100 nm was developed by using the spectrum selection self-injection locking (SSSIL) method in 1992. The authors realize tunable picosecond radiation from an all solid-state laser with 146-200 ps pulses in an 88 nm range. Also, 70 fs pulse generation was achieved using a Kerr-lens mode-locking pumped with an Ar⁺ laser     

Thermal motion of α-helical molecules in highly crystalline poly(γ-methyl l-glutamate) films

Solid films of poly (γ-methyl l-glutamate) were prepared by casting solutions in chloroform, dichloromethane, and m-cresol. The mode and amplitude of thermal molecular fluctuations in the crystalline phase were studied by X-ray diffraction. All the films contain α-helical molecules and have hexagonal crystal structures, but differ from each other in their crystallinity and crystallite size. The calculated molecular fluctuation amplitudes also differ considerably. Below a threshold temperature in the range 140°–190°C (different for each sample), the segmental molecular motion is composed of translation along the chain axes coupled with rotation about the axes. At higher temperatures, the structure changes thermoreversibly into a modification, in which a screw-type motion along the α-helix axis is predominant.     

HYDRODYNAMICS—DOES IT TRAP OIL?*

In order for the hydrodynamics of meteoric water to be an important trapping mechanism for hydrocarbon accumulations, it must have existed for a long geologic period extending from the time of secondary hydrocarbon migration and its accumulation to the present time. However, in most interior sedimentary basins, the present hydrodynamic patterns are considered to have been developed only a short while ago (geologically speaking), after the significant uplift and the associated erosional events which caused the present topographical relief. Most petroleum accumulations were probably formed a long time before the development of the present hydrodynamic flow patterns, and hence must be explained by different mechanisms that have been effective for a much longer geologic period.
This paper also discusses other possible problems in applying the hydrodynamics concept to understanding the formation of petroleum accumulations, such as the lack of proper water passways and outlets in several basins, the difficulty of moving water through hydrocarbon-saturated sections of a reservoir, and the difficulty of keeping significant salinity gradients in a reservoir where active water flow has taken place.