Size determination of microscratches on silicon oxide wafer surface using scattered light

Scattered light intensity distributions from microscratches on a silicon oxide wafer surface are simulated and analyzed for the purpose of microscratch sizing using a boundary element method (BEM)-based electromagnetic scattering simulator. At normal incidence, the characteristic scattered light resulting from microscratches appears in two symmetric regions of scattering angles, namely, at high and low angles. The scattered light intensities at high and low angles show characteristic fluctuation according to the depth and width variations of microscratches. It is found that the size of a microscratch can be obtained from the scattered light intensities at these characteristic angles. We propose microscratch sizing map which uses the detected light intensities to size the microscratches. Once the map is created, quick and easy categorization of microscratch size can be realized by collating the detected intensities with the map. The major advantage of using the map is the ability to measure simultaneously not only microscratch width but also depth. Generally, the depth cannot be obtained from an imaging system. Several experiments demonstrate the feasibility of our scheme and their results are in very good agreement with the simulation results.     

Photoresponsive permeability of polyelectrolyte complex capsule membrane containing triphenylmethane leucohydroxide residues

To develop a functional capsule, which can be controlled to release materials entrapped in the inner aqueous space responding to light, partly crosslinked poly(acrylic acid)–poly-ethylenimine complex capsules containing a copolymer of acrylic acid and bis[4-(dimethylamino)phenyl](4-vinylphenyl)methyl leucohydroxide as an additional membrane component with radii of ca. 3 mm have been prepared. The triphenylmethane derivative on the copolymer dissociated into an ion pair under ultraviolet light irradiation in the weak alkaline region. Permeation of p-toluenesulfonate through the capsule membrane was enhanced significantly by the photoirradiation after a several minutes time lag under a weak alkaline condition. The photoinduced increase in permeability of the capsule was pH-dependent. The maximum effect of light on the permeability was observed near pH 8, whereas less enhancement was observed above or below the pH value. When the irradiation of the light was stopped, permeation of the permeant decreased. The photoresponsive permeability change of the capsule membrane can be carried out reversibly. © 1995 John Wiley & Sons, Inc.     

Influence of Joining Interlayer on Impact Damage to Laminated Boron Carbide Ceramics

Impact damage of laminated B₄C ceramic samples was investigated using four types of aluminum sheets — without holes and with 25 4‐, 8‐, and 25‐mm‐diameter holes — at joining ratios of 100, 94, 76, and 45%. Four 1‐mm‐thick B₄C ceramics plates were laminated using three aluminum sheets of the same type and joined at 700°C in vacuum. In impact damage tests using spherical SUJ‐2 projectile with a diameter of 4 mm with a velocity of approximately 300 ms^?1, bulk B₄C showed a large conical crack and significant fractures; the conical crack in the laminated samples was smaller than that of the bulk B₄C. However, the conical cracks of the laminated B₄C with the joining ratio 45 to 96% were of the same size, irrespective of the joining ratios. The total load and induced pressure area on the rear side of laminated samples were smaller than that observed for bulk B₄C, and total load and induced pressure area were similar for laminated samples with high and low joining ratios. The maximum pressure on the rear face of laminated B₄C samples was higher than that observed for bulk B₄C and increased with decreasing joining ratio of laminate interlayer.     

EXTRACTIVE FERMENTATION OF PHENYLALANINE USING UNCHARGED POLYMERIC BEADS

Extractive fermentation was employed for the production of phenylalanine using an agitated and aerated fermenter. Uncharged polystyrene beads (Amberlite XAD-16) were packed in an external column and used to extract the phenylalanine in an intermittent fashion during the fermentation. Even though no cell separator was used and the fermentation broth was fed directly to the column, the overall system performed well without any clogging of the column. It was found that 43% of the phenylalanine could be extracted during the fermentation, and it was thus proved that extractive fermentation is an effective way to prevent the crystallization of phenylalanine. In addition, fermentation performance as also improved due to the relief of self-inhibition by phenylalanine. When 1.2 L of the beads was used and sufficient hydrophobic nutrients were present, the concentration and productivity increased 18% and 55% greater than in the control fermentation, respectively. These results show that extractive fermentation is a very attractive method to enhance production as well as to avoid crystallization. Numerical simulation modeling was also performed in this study for extractive fermentation. The results from the modeling corroborated the experimental data, thus confirming the reliability of the model.     

Preparation of Anti-Sticking Substance for Cooked Noodles by Fungal Hydrolysis of Potato Pulp

Potato pulp containing starch, cellulose, hemicellulose, and pectin is an agricultural by-product in the starch industry. Potato pulp was hydrolyzed by semiaerobic growth of the fungus Amylomyces rouxii, mixed with water, and filtrated to separate water-soluble materials. The obtained extract had the capability to significantly reduce stickiness in the gel made with wheat flour. Similar effects were observed in the extract of potato pulp hydrolyzed by a commercial pectinase. When covered with the extract, the cooked noodles were easily disentangled by shaking after overnight refrigeration. The effective components obtained from the extract by precipitation included pectin predominantly composed of uronic acid and galactose with a molecular weight of 10⁵ to 10⁶. The extract from potato pulp is useful as an anti-sticking substance for cooked noodles sold in retail stores.     

Patterns of scientific collaboration between Japan and France: Inter-sectoral analysis using Probabilistic Partnership Index (PPI)

Summary In this article we present an indicator - Probabilistic Partnership Index (PPI) - for use in measuring scientific linkages. This indicator is based on the Monte-Carlo simulation which provides a standard model to each network established in collaboration between two countries. Any relationship that occurs within a (whole) network can be projected to a standard model respectively and thus PPI is useful in examining individual networks within complex exchanges. We investigate inter-sectoral cooperation between France and Japan for the period of 1981-2004, by classifying every research unit appearing in the data set by its sector. We examine international collaborative patterns, domestic collaborative patterns and multilateral relationships established within the French-Japanese cooperation. We also compare PPI with the classic collaborative linkage indexes - Jaccard Index, Salton-Ochiai Index and Probabilistic Affinity Index - in order to describe the specificity of the new indicator. Our hope is that PPI will prove to be a useful and complementary tool for the analysis of international collaboration.     

Synchrotron Beam Test of a Position-Sensitive Small-Pixel Ir-TES Array

Small-pixel TES is promising for imaging-spectroscopy applications. Researchers demand a high-spatial-resolution energy-resolving detector for many kinds of applications. However the spatial resolution and the energy resolution are quite restricted in the present semiconductor detector, so we are developing a new pixellated array based on the transition edge sensor (TES) technology. In this measurement, we developed an Ir-TES array which consists of 9 small TESs and are voltage biased in parallel. We performed measurements at SPring-8 with 6 keV X-rays and scanned the TES using a collimator by the two-dimensional scanning method. Position dependency on pulse height and risetime has been analyzed in detail.     

Polyol-based phase-change thermal interface materials

Polyol-based phase-change thermal interface materials that exhibit high thermal contact conductance and thermal stability have been developed for microelectronic cooling. By using a diol (polycaprolactone or polyester diol in the form of 2-oxepanone) of molecular weight 1,000–2,000 amu, along with 4 vol.%-hexagonal boron nitride particles, this work attained thermal contact conductance (at 70°C, across copper surfaces) that is higher than that attained by using paraffin wax, polyether glycol, polyethylene glycol, or tetradecanol (in place of the diol) and that attained by commercial phase-change thermal interface materials. The thermal stability of the diol is superior to the other phase change materials mentioned above, although the heat of fusion is lower. Boron nitride is more effective than carbon black (also 4 vol.%) for enhancing the conductance, but carbon black diminishes the heat of fusion less than does boron nitride.     

Developing the geothermal resources map of Iran

Geothermal exploration involves a high degree of uncertainty and financial risk, and requires reliable exploration data to constrain development decisions. The paper describes a geothermal exploration and resource identification method that is based on building a map of potential geothermal resource areas by combining geological, geochemical and geophysical datasets; it is a powerful tool for visualizing new and existing data during decision-making processes. By performing suitability analysis and geothermal area identification, and by establishing criteria to define geothermal resources with development potential, a map of Iran was constructed highlighting 18 promising areas.