Polymers of α-substituted benzyl methacrylates as a new type of electron-beam resist

Summary Polymer of α-substituted benzyl methacrylate was found to be used as a new type of positive electron-beam resist, which forms methacrylic acid units in the polymer chain on the exposure to electron-beam and can be developed using alkaline solution as a developer. The sensitivity was dependent on the bulkiness of the ester group and the number of ?-hydrogen atoms in the ester group. The sensitivity and γ-value of atactic poly(α, α-dimethylbenzyl methacrylate) were improved by a factor of more than three over poly (methyl methacrylate).     

Optimum conditions for second harmonic generation by hot-electron and electron-transfer effects in semiconductors

Optimum conditions for second harmonic generation (SHG) are derived analytically in both semiconductors with a velocity-saturation characteristic due to hot-electron effect and with an N-shaped characteristic due to electron-transfer effect. The d.c. bias fields for a maximum conversion efficiency are approximately the value of the ratio of a saturation velocity to a low-field mobility for a saturated characteristic and the value slightly less than the threshold field for an N-shaped characteristic. For a saturated characteristic, the shape closer to a rectangular gives a higher conversion efficiency. An n-type Ge is most superior to all of p-type Ge, n- and p-types Si. For an N-shaped characteristic, steeper spike shape gives a higher conversion efficiency. An n-type GaInSb is most superior to both of n-types GaAs and InP.     

Solution of linear equations for small computer systems

A solution technique, based on Gauss elimination, is described which can solve symmetric or unsymmetric matrices on computers with small core and disk requirement capabilities. The method is related to frontal techniques in that renumbering of the nodes, such as in a finite element mesh, is not required, and the elimination is performed immediately after the equations for a particular node have been fully summed. Only two rows of the matrix need be on core at any step of the solution, but for more efficiency, the program presented here requires all the equations associated with two nodes to be on core. Minimum disk storage is achieved by storing only nonzero entries of the matrix, a single pointing vector for each node, regardless of the number of degrees-of-freedom, and the use of a single sequential file. Special care is taken of the boundary nodes where only the diagonal and the right-hand-side vector are stored. Assembly and elimination for these nodes are avoided completely. The performance of the program is compared with both symmetric and nonsymmetric frontal routines and is shown to be acceptable. The major merit of the method lies in the fact that it can be implemented on small minicomputers. The reduction of core and disk storage inevitably increases the solution time, but the decrease in the output file size also makes the back-substitution and resolution processes more efficient. In some cases, the total solution time can be shorter than for the frontal method due to this property.     

Gasification reactivities of metallurgical cokes with carbon dioxide,steam and their mixtures

Gasification reactivities of cokes with carbon dioxide, steam and their mixtures at 1200 °C were investigated, using seven single cokes made in a laboratory furnace from single coals of different properties, and also one commercial coke. The reactivity with steam was significantly higher than that with carbon dioxide. The reactivities of the mixture increased proportionally with increasing steam content above 10%; however, the reactivity below 10% steam content was smaller than that with pure carbon dioxide, the minimum reactivity being observed at a steam content of 2–4%. The reactivities of the compounds corresponding to optical texture were determined by analysing the coke microscopically before and after gasification. In general, except for one coke, the inert texture was the most reactive. Increasing size of the optical unit decreased the gasification reactivity, fibrous and leaflet textures were the least reactive. Gasification with steam developed pores within the inner region of the coke, whereas carbon dioxide reacted with the coke at or near the surface, producing a relatively smooth surface. Some proposals are suggested for better coke production.     

Software package for large-scale 0–1 linear programming on Unix system: GUB technique

Recently, a multiple criteria decision making (MCDM) has been well established as a practical approach to seek a satisfactory solution to a decision making problem. Linear programming (LP) is one of the most widely used OR/MS/IE techniques for solving MCDM problems. In the realistic decision making problems, many LP problems are involved a large number of 0–1 decision variables and a special type of system structures. So much kind of the large-scale 0–1 LP problems are simply too large fit into a microcomputer/workstation.

In this paper, we develop a software package micro 0–1LP(GUB) for solving LP problems with a generalized upper bounding (GUB) structure as large-scale 0–1LP problems on UNIX systems. From the views of the computational experience and storage requirement, micro 0–1LP(GUB) using the C programming language is implemented an efficient method in which the GUB structure would be effectively handled.

As a real-world large-scale 0–1LP problem with the GUB structures by the micro 0–1LP (GUB) software package developed here, we demonstrate an optimization problem of system reliability for selecting the allocating the components on an UNIX system, Sanyo/Icon MPS 020.     

Production of docosahexaenoic acid by marine bacteria isolated from deep sea fish

Five bacterial strains isolated from the intestine of deep sea fish were shown to produce docosahexaenoic acid (22∶6n−3; DHA) at a level of 6.4 to 11.6% of total fatty acids when incubated in DHA-free medium. In all of the strains examined, other polyunsaturated fatty acids were barely detectable, except for eicosapentaenoic acid (20∶5n−3). A typical strain, such as T3615, produced DHA at a concentration of about 0.8 mg/L within six days of aerobic incubation at 5°C and under atmospheric pressure. The T3615 strain, belonging to the genusVibrio, is rod-shaped, Gram-negative, motile and facultatively anaerobic.     

Relationship between brightness/luminance ratio and additivity‐law failure

The degree of additivity‐law failure of a mixture color consisting of two component chromatic colors has very complex characteristics depending on the used component colors and their mixing conditions. It is significantly affected by the mixture‐color chromaticity and by the brightness/luminance ratio at the chromaticity. A simple relationship was derived between the following quantities: degree of additivity‐law failure, additivity‐law luminance (luminance of the mixture color derived by postulating additivity law), and brightness/luminance ratio at the chromaticity of the mixture color. This relationship can be applied to any additivity‐law failure experiment and any formula on brightness/luminance ratio. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 185–190, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/col.10045     

A comparison of hand preference in Japan and Canada.

An analysis was performed on 47 items of a hand preference inventory administered to 1275 undergraduate students in Japan and Canada. Factor analysis indicated that items grouped into three factors, representing skilled activities, unskilled activities, and turning movements. Analysis of the factor scores revealed that neither skilled handedness nor unskilled handedness was significantly influenced by cultural group or sex. On the third factor, Japanese students were far more right-handed than were Canadian students. Although mean factor scores for skilled handedness did not differ between groups, the prevalence of left-handedness was significantly lower in Japan than in Canada. Cultural pressures have their primary effect on turning movements, and on specific skilled activities such as writing and eating. Although the data are consistent with the view that a right shift for skilled activities has been superimposed on an undifferentiated handedness, other considerations make such a theory less tenable. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Restoration of peroxisome formation in two conditional peroxisome-deficient mutants of Hansenula polymorpha during growth of cells on specific organic nitrogen sources

Expression of the peroxisome-deficient (Per^?) phenotype by per mutants of Hansenula polymorpha is shown to be dependent on specific environmental conditions. Analysis of our collection of constitutive and conditional per mutants showed that, irrespective of the carbon source used, the mutants invariably lacked functional peroxisomes when ammonium sulphate was used as a nitrogen source. However, in two temperature-sensitive (ts) mutants, per13-6^ts and per14-11^ts, peroxisomes were present at the restrictive temperature when cells were grown on organic nitrogen sources which are known to induce peroxisomes in wild-type cells, namely D -alanine (for both mutants) or methylamine (for per14-11^ts). These organelles displayed normal wild-type properties with respect to morphology, mode of development and protein composition. However, under these conditions not all the peroxisomal matrix proteins synthesized were correctly located inside peroxisomes. Detailed biochemical and (immuno) cytochemical analyses indicated that during growth of cells on methanol in the presence of either D -alanine or methylamine, a minor portion of these proteins (predominantly alcohol oxidase, dihydroxyacetone synthase and catalase) still resided in the cytosol. This residual cytosolic activity may explain the observation that the functional restoration of the two ts mutants is not complete under these conditions, as is reflected by the retarded growth of the cells in batch cultures on methanol.     

Vertebrate retinal ganglion cells are selected from competent progenitors by the action of Notch

The first cells generated during development of the vertebrate retina are the ganglion cells, the projection neurons of the retina. Although they are one of the most intensively studied cell types within the central nervous system, little is known of the mechanisms that determine ganglion cell fate. We demonstrate that ganglion cells are selected from a large group of competent progenitors that comprise the majority of the early embryonic retina and that differentiation within this group is regulated by Notch. Notch activity in vivo was diminished using antisense oligonucleotides or augmented using a retrovirally transduced constitutively active allele of Notch. The number of ganglion cells produced was inversely related to the level of Notch activity. In addition, the Notch ligand Delta inhibited retinal progenitors from differentiating as ganglion cells to the same degree as did activated Notch in an in vitro assay. These results suggest a conserved strategy for neurogenesis in the retina and describe a versatile in vitro and in vivo system with which to examine the action of the Notch pathway in a specific cell fate decision in a vertebrate.