Activation of wood surface by corona treatment to improve adhesive bonding

Oxidative activation of resinous wood surfaces by a corona treatment to improve adhesive bonding was studied. It was found that the wettability of the veneers, including hardwoods, softwoods, and tropical woods increased with an increase in the degree of treatment, and the gluability increased rapidly after the initial mild treatment. To elucidate the nature of any chemical change occurring on the wood surface, the dyeing examination of the wood and its components with Schiff's reagent was made, and the results showed a higher dyeing ability for corona-treated samples compared to untreated ones, indicating that aldehyde groups increased by the corona treatment. The treatment affected the alcohol-benzene extractives, and oxidized them to produce aldehyde groups. Especially, the neutral fraction in the extractives was significantly affected. On the other hand, negligible chemical effects of the treatment on the surface modification of the wood's main components were seen. Both the untreated and corona-treated samples adsorbed basic dye to the same extent of coloration. Thus, no measurable carboxyl groups increased on the surface of the samples. It seems that an increase in the wettability of corona-treated wood veneers resulted mainly from the oxidation of the high hydrophobic surface layer of neutral fraction substances in the extractives, and from the reduction in their hydrophobicity. © 1993 John Wiley & Sons, Inc.     

Low-threshold current low-voltage vertical-cavity surface-emittinglasers with low-Al-content p-type mirrors grown by MOCVD

InGaAs quantum-well vertical-cavity surface-emitting lasers with low-Al-content p-type mirrors grown by metalorganic chemical vapor deposition (MOCVD) have have been characterized. Series resistance in p-type Al_xGa_1-xAs/GaAs mirrors decreases drastically as the Al content in Al_xGa_1-xAs decreases from AlAs. Air-post devices with a p-type Al_0.06Ga _0.4As/GaAs top mirror exhibit a room temperature CW threshold current of 1.8 mA at an operating voltage of 2.0 V (with a threshold power consumption at 3.6 mW)     

Analysis of cases allowed to cease erythromycin therapy for diffuse panbronchiolitis--comparative study between patients with cessation of the therapy and patients continuing the therapy

We investigated the effect of erythromycin (EM) in patients with diffuse panbronchiolitis (DPB) who were divided into 2 groups, the short term group with 8 patients who were treated for at least 2 years and the long term group with 7 patients who were treated for more than 3 years. Each mean value of %VC, FEV1.0, FEV1.0% and PaO2 two years after administration to these patients was improved than before administration of EM, with the exception of PaO2 in the long term group. There was no change in %VC, FEV1.0, FEV1.0% or PaO2 in each group between one year after the therapy and thereafter, with the exception of the fact that FEV1.0% in the short term group, except patients restarting EM therapy, 2 years after the therapy was significantly higher than in the long term group. One patient was readministered EM because of recurrence of DPB after cessation of EM therapy, whose %VC, FEV1.0 and PaO2, but not FEV1.0%, one year after the therapy were increased in those before the therapy. The Neutrophil proportion in the bronchoalveolar lavage (BAL) fluid in this patient was still high after the therapy (94.5%), while that in the patients with cessation of the therapy was improved to the level of less than 8%. Neutrophil proportion in BAL fluids in the patients with continuation of the therapy revealed a high or low level after the therapy. These results suggest that the patients, whose %VC, FEB1.0% and PaO2 were improved and whose proportion of neutrophils in BAL fluid reduced to a normal level compared with those before EM therapy, can be allowed to cease therapy after 2 years or more of EM therapy.     

Support system for finite element analysis

This paper describes work aimed at developing an intelligent support system for finite element modeling and a methodology for managing input data model. Analyzing various statement structures of input data, three structural interface models — the hierarchical browser, the spread sheet and the model generator — are proposed for advanced representation and editing. Two knowledge models composed of macro visual data representation (user oriented model) and micro regularized data representation (processor oriented model) are revealed in conformity with the approach of object-orientation. Moreover, an extended relational schema composed of a composite object (assembly of functional elements) and several abstracted scalar indexes has been implemented for case retrieval.     

Thermodynamic evaluation of the phase equilibria and glass-forming ability of the Ti−Be system

The glass-forming ability of Ti−Be alloys is of great interest. Experimental and theoretical evaluations of the glass-forming ability of this binary alloy show that the formation of a metastable TiBe phase with a CsCl-type B2 structure controls the glass-forming ability in this system. However, there is no information on the thermochemical properties of metastable TiBe for the quantitative evaluation of the glass-forming ability using Davies-Uhlmann kinetic formulations. We have carried out a thermodynamic analysis using experimental phase diagram data and the energy of formation of the stoichiometric compounds from ab initio calculations. Furthermore, the Gibbs energy of formation for the body-centered cubic (bcc) phase was evaluated over the entire composition range by applying the cluster expansion method (CEM) to the total energy of some bcc-based ordered structures obtained from ab initio calculations. For the bcc phase, the two-sublattice formalism, (Ti, Be)_0.5(Ti,Be)_0.5, was adopted to describe the A2/B2 transformation. A good agreement between the calculated values and experimental phase equilibria was obtained. Evaluation of the glass-forming ability was also attempted utilizing the thermodynamic quantities obtained from the phase diagram assessment. The calculated glass-forming ability agrees well with the experimental results. This paper was presented at the International Symposium on User Aspects of Phase Diagrams, Materials Solutions Conference and Exposition. Columbus, Ohio, 18–20 October, 2004.     

Application of AC plasma display panels to radiation detectors

Radiation detector proposals that use plasma display panels are rare. In this work, we confirmed a radiation detector that uses plasma display panels that are focused on the breakdown voltage shift in the ramp waveform. We adapted the cell structures, gas contents, and waveforms of plasma display panels (AC‐PDPs) for radiation detectors. Hard X‐rays and gamma rays induce electron emission into the discharge gas, resulting in generating electrons, electron multiplication, and charge accumulation on dielectrics. The radiation dose rate of hard X‐rays and gamma rays (Cs137) is measured as a breakdown voltage shift between anodes and cathodes. For gamma rays, the detection sensitivity in this experiment is not as high as in the case of hard X‐rays, but the detector can locate gamma rays. These results suggest that adapted AC‐PDPs can detect both hard X‐rays and gamma rays and can be used in a large two‐dimensional radiation detector.     

Permeability of a series of alcohols through poly(γ-methyl-d-glutamate)

To elucidate the permeation mechanism in polypeptide membranes, permeation of a series of alcohols through poly(γ-methyl-d-glutamate) is studied. Breaks occur at the second order transition temperature in the Arrhenius plots of the diffusion coefficient and so it is concluded that the diffusion of small molecular substances in polypeptide occurs through the side-chain region between helices. These contain local coarse areas which contribute to the diffusion as effective holes without requiring vigorous molecular motion. The diffusion coefficient decreases systematically with increase of molecular size of penetrant.     

Influence of coal characteristics on CO2 gasification

The rate of CO₂ gasification of a coke is one of the most important qualities of metallurgical coke. Many workers are trying to estimate the rate of CO₂ gasification of coke by studying properties of coal, such as the reflectance of vitrinite and the amounts of inertinite and ash in coal. The specific-gravity separation method is used to prepare coals which possess almost the same reflectance, but contain different amounts of inertinite and ash. The relation between the rate of gasification and the properties of coal is quantitatively explained.     

Wood photography using light irradiation and heat treatment

To apply the coloring method using light irradiation and thermal treatment to print photographs on wood, the effect of the transmittance of negative films was investigated. ΔE* decreased with light irradiation when specimens covered with films with transmittances exceeding 20% were irradiated for 100 h. It was thought that this phenomenon was due to the decrease in Δb*. The color of light‐irradiated wood changed remarkably with thermal treatment; however, the change in the color of exposed specimens covered with films with transmittances exceeding roughly 20% became constant. Clear photographs could be printed on wood using negative films with transmittances less than approximately 20%. Furthermore, the difference between the maximum and minimum values of ΔE* after thermal treatment was about 22. Humans can distinguish four to seven colors that can be created by this method. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 312–316, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20027