The leveling of thermosetting waterborne coatings. Part IV: Effects of film thickness

The influence of film thickness on the leveling of a thermosetting waterborne coating (WBC) was examined. The theory of Patton has been revised to give the proper force balance and modified to include the changes in surface tension and viscosity during leveling by the evaporation of volatile components. However, the predicted leveling process by a numerical method did not coincide with the observed results. Thus, the driving force in the theory, the hydrostatic pressure gradient in the film, was considered to be insufficient to describe the leveling process of the WBC. The hydrostatic pressure gradient can be a component of the driving force to promote leveling, but the existence of an additional component is suggested.     

The leveling of thermosetting waterborne coatings. Part III: Leveling under controlled conditions

Experiments on coated films of water borne, coatings (WBC) under controlled conditions (i.e., 25°C, 65% RH) were carried out to study the mechanism of leveling. Data in a companion paper imply that the development of the surface tension gradients plays an important role in promoting leveling. The stress due to surface tension gradients is found to be much greater than the stress introduced by hydrostatic pressure gradients in the film caused by surface tension and the free boundary curvature of the film. This reconfirms that the use of a co-solvent, which evaporates faster than water, greatly accelerates the leveling of a WBC.     

Sleep package model mathematical model for a sleep pattern

In order to design the better sleep-wake schedule for shift workers, the mathematical model for sleep called SLEEP PACKAGE MODEL was developed. When we get three parameters; time to fall asleep (t), the length of sleep period (Ls), and the waking time (Tw) before a sleep are given, the model can predict the sleep pattern, namely NonREM-REM cycle pattern. In order to examine the ability of the model, the sleep patterns for 60 nights of 20 male young adults were recorded under the usual night condition (t=23:00, Ls=8 hrs, and Tw=16 hrs), and the recovery sleep of one university male student was recorded after the 72 hrs sleep deprivation condition (t=09:00,Ls=10 hrs, and Tw=72 hrs). The usual night sleep and the recovery sleep after sleep deprivation were predicted by the model. The estimated sleep patterns by the model were compared with the actual sleep pattern in the experiment, as the results, the estimated sleep patterns by the model is very similar to the acutal sleep patterns. So thatm the result suggests that the application of this model to human engineering field could be expected.     

New developments in ionized-cluster beam and reactive ionized-cluster beam deposition techniques

Ionized-cluster beam (ICB) and reactive ionized-cluster beam (R-ICB) deposition techniques are described from the standpoint of the ion-based technique, as applied to the production of thin film devices. In ICB deposition, clusters (macroparticles consisting of approximately 10³ atoms loosely coupled together) instead of atomic or molecular particles are used after ionization, resulting in a remarkable improvement of epitaxial film growth and of the quality of deposited films with strong adhesion. This paper describes in detail the influences of the ion content and the acceleration voltage on nucleation and film properties. MnBi films as magneto-optical memories and ZnO epitaxial films as optical devices are discussed as practical applications of the ICB and R-ICB deposition techniques.     

A fundamental study on recovery of copper with a cation exchange membrane: Part 1 — Ion exchange equilibria between cupric and hydrogen ions

It is possible to concentrate metal ion against the gradient of its concentration through a cation exchange membrane. The membrane has a high ion exchange capacity and is hydrophilic, therefore a rapid transfer rate of ions is expected. Ion exchange equilibrium data between cupric and hydrogen ions for sulfuric and nitric acid systems are obtained and analyzed quantitatively for concentrations of dissociated cupric and hydrogen ions.     

Oxidation of cholesterol catalyzed by amyloid beta-peptide (Abeta)-Cu complex on lipid membrane

A catalytic reaction of H2O2 production by an amyloid beta-peptide (Abeta)-Cu complex with cholesterol incorporated in a liposome was kinetically analyzed. The Michaelis-Menten model was applied to the H2O2 production reaction using cholesterol as the substrate catalyzed by the Abeta-Cu complex. The Km value for the Abeta-Cu complex catalytic reaction with cholesterol-containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposomes (Km=0.436 microM for Abeta(1-40); Km=0.641 microM for Abeta(1-42)) was found to be smaller than that with cholesterol-containing 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes (Km=0.585 microM for Abeta(1-40), Km=0.890 microM for Abeta(1-42)). The results imply that membrane properties could play an important role in the interactions of the Abeta-Cu complex with cholesterol in these liposomes. Considering the physical states of the cholesterol/POPC (liquid disordered phase) and cholesterol/DPPC (liquid ordered phase) liposomes in the present reaction conditions, the data obtained suggests that the H2O2-generating activity of the Abeta-Cu complex, accompanied by oxidation of membrane-incorporated cholesterol, could be effected by the phase of the liposome membranes.     

Real-time observation for the enzymatic reaction of phospholipid membrane: application of the time-resolved quasi-elastic laser scattering method

An analytical technique to measure reactions in biological membranes was developed and applied to monitoring the hydrolysis reaction of phospholipids (dipalmitoylphosphatidylcholine, DPPC) by phospholipase A(2). The technique uses the time-resolved quasi-elastic laser scattering (TR-QELS) method to measure an oil/phospholipid monolayer/water membrane system by monitoring the change of interfacial tension under a noncontact condition and in real time. When the TR-QELS method is used with the newly developed oil/phospholipid monolayer/water membrane system, measurement of the hydrolysis reaction of phospholipids with long alkyl chains (C >or=16), which are the major components in biological membranes, becomes possible. The reaction progress is monitored by the increase of interfacial tension at the oil/water interface caused by the decrease of surface-active DPPC molecules due to the reaction. The characteristic phases, namely, lag, burst, and equilibrium, are observed. The relationship between the duration of the lag phase (the rate-limiting step of the reaction) and the concentration of calcium ion (an essential cofactor of the reaction) is also investigated. Increase of calcium ion concentration in the subphase is found to shorten the duration of the lag phase. In addition, the real-time measurement simplifies the estimation process for the reaction activation energy.     

Ionized-cluster beam deposition and epitaxy as fabrication techniques for electron devices

It is shown that the ionized-cluster beam deposition and epitaxy techniques are useful for semiconductor device fabrication. The deposited film shows good adhesion, good conduction even in a very thin film and a good crystalline state. These techniques have been applied to interconnections and semiconductor material preparation for devices and integrated circuits. Solar and electroluminescent cell have been fabricated.     

Detection of a heat stress-mediated interaction between protein and phospholipid membrane using dielectric measurement

The dielectric response of lipid bilayer membrane vesicles (liposomes) prepared using either phosphatidylcholine from egg (EPC) or 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) was analyzed at a frequency range of 0.1 to 100 MHz. A marked dielectric dispersion for EPC and POPC liposome suspensions was observed above 1 MHz. An appropriate analysis of the dielectric dispersion curve was performed using the Cole-Cole equation and the Debye equation and was found to provide a method for the determination of dielectric parameters. Among the dielectric parameters, the characteristic frequency of a second dispersion around 50 MHz varied corresponding with changes in the test conditions. Of particular note is that an anomalous change in the characteristic frequency in the presence of protein corresponded to the degree of hydrophobic interaction between proteins and liposomes. The value of the frequency around 50 MHz, as well as the decrease in permittivity over the frequency range tested, are indicators of the interaction between proteins and liposomes.     

ELID precision grinding of large special Schmidt plate for fibre multi-object spectrograph for 8.2 m Subaru telescope

To explore various scientific frontiers from nearby substellar objects to large scale structures of the high redshift universe, a Fibre Multi-Object Spectrograph (FMOS) is being developed as the second generation near-infrared measuring instrument for the prime focus of 8.2 m Subaru telescope in Hawaii, which employs a large special Schmidt plate element. The Schmidt plate consists of a large non-axisymmetric aspherical concave plate and a convex plate. This paper introduces its manufacturing process, focusing on its non-axisymmetric aspherical surface machining by utilizing synthetically ELID grinding and arc-enveloped grinding method. A new grinding system capable of fabricating large optical elements was developed with 10 nm resolution. In this ELID arc-enveloped grinding system, a Cast Iron Fibre Bonded (CIFB) diamond wheel was 3D controlled to scan the workpiece to generate required surface. Grinding characteristics such as attainable form accuracy, surface roughness were investigated. Furthermore, some measures to improve form accuracy were discussed and verified.