A breakthrough to the plasma deposited dry-developable e-beam resist

This paper presents the preliminary results of efforts to improve dry processed electron beam resist materials using plasma polymerization coating technology. Three approaches investigated were chemical susceptibility modification, the use of multilayer resist structures, and the effect of grafting reactions.     

Separation of Small Particles Suspended in Liquid by Nonuniform Traveling Field

A study of size and charge-dependent separation of small particles in liquid using a traveling-field-type electric curtain device is made. The principle of the separation is to make use of the spatial harmonic components of the rotating traveling field produced by such a device, the first harmonic propagating in one direction, which plays a dominant role in the region distant from the electrodes, and the second harmonic propagating in the opposite direction, which becomes dominant near the electrodes. Small particles brought into this field undergo circular motion and, as a result of field nonuniformity, are repelled from the electrodes and drift in the direction of the dominant harmonics. The lighter or more charged particles are strongly repelled from the electrodes and swept by the first harmonic, while the heavier or less charged particles can approach the electrodes and are transported by the second harmonic in the opposite direction, thus enabling separation by mass and charge. First a theoretical investigation of this method is made to clarify the operation conditions for the separation, then the experimental observations of particle motion are made and scaling laws of transport velocity with the applied voltage and frequency are confirmed. Finally, an example of a cell separator design using this method is presented.     

Metabolism of 12-ketooctadecanoic acid byEscherichia coli K-12 andCandida tropicalis

The mode of degradation of long chain keto acids by two microorganisms was investigated.Escherichia coli K-12 converted 12-ketooctadecanoic acid to 4-ketodecanoic acid, accumulating some amounts of intermediates, 10-ketohexadecanoic, 8-ketotetradecanoic and 6-ketododecanoic acids. In contrast,Candida tropicalis completely metabolized the keto acid with transient accumulation of the metabolites mentioned above. The difference between the metabolism byE. coli of hydroxy acid and keto acid is that 12-hydroxyoctadecanoic acid is degraded as far as 6-hydroxydodecanoic acid, while 12-ketooctadecanoic acid can be degraded as far as 4-ketodecanoic acid.     

Effect of water-Insoluble Powder Addition on Physical Properties of Gelatin Gel

Water-insoluble powder is often dispersed in shells of commercial soft capsules for various reasons, but little reports have been published about the effect of powder addition on the physical properties of the gelatin gel. Glass powder, titanium oxide, calcium carbonate and γ-orizanol were used as model of powder. Changes of Young modulus obtained from the tensile test showed that any powder addition to the gelatin sheet made the gelatin sheet hard not by the surface effect of powder but by the volumetric effect of it. In this test, any powders had no effect on the tensile strength of the gelatin sheet because there was little interaction between each powder and the gelatin gel in the break point. The limiting strain was decreased a little up to the specific amount of each powder and then beyond the specific amount that decreased steeply in the case of glass powder and γ-orizanol. There might be a suitable range of the amount of powder for the gelatin sheet to keep the plastic flow similar to the gelatin sheet containing no powder. In this work, it was shown that the physical properties of the gelatin shell would be regulated by powder addition to the gelatin sheet.     

CREEP-FATIGUE STUDIES UNDER A BIAXIAL STRESS STATE AT ELEVATED TEMPERATURE

In order to study creep-fatigue interactions under multiaxial stress states, both push-pull and reversed torsion low-cycle fatigue tests were carried out using an austenitic stainless steel, SUS 304, at 923 K in air. From the tests, it is concluded that the hold-times introduced at the peak strain reduce low-cycle fatigue lives in the push-pull mode, but in the torsional mode they were not so harmful. This difference in the hold-time effect is discussed from considerations of crack formation and propagation and the stress amplitude applied to the specimen. Both maximum principal strain range, Δε₁, and the von Mises' equivalent strain range, Δε_eq, provide a nearly adequate comparison base for the assessment of biaxial low-cycle fatigue lives in tests without strain hold-time but are inadequate for hold-time tests. An equivalent stress range, Δσ*, which includes the effect of the stress parallel to the fatigue crack and which was previously proposed by the authors for no hold-time tests, is applied to the hold-time tests in the biaxial stress state. It is found that Δσ* is a good parameter for the correlation of biaxial low-cycle fatigue data in both no hold-time and hold-time tests.     

Effect of polymer matrices on magnetic properties of plastic magnets

Plastic magnets were prepared using commercial polyamide (Nylon 12), polystyrene and ethylene-vinylacetate copolymer, and three kinds of ferrite magnetic powders with different concentration levels (20, 35 and 50 vol%). Their magnetic properties and thermal stability are discussed comparing viscoelasticity and thermal properties of the polymers and plastic magnets. Magnetic properties of the anisotropic plastic magnets were largely dependent on the concentration of the magnetic powder and its degree of orientation in the matrix. The degree of the orientation was mainly affected by the interaction between polymer matrix and magnetic powder, and viscoelastic property of the matrix polymer. It was also affected to some extent by the shape of the magnetic particles. The order of the interaction of the polymers to the magnetic powders was as follows: PA > EVA copolymer > PS, and PA-bonded magnets gave the highest magnetic properties among the matrices examined. The decrease in magnetic properties due to the change in the orientation of magnetic powder rarely occurred during thermal treatment.     

New annealing method and CaGe garnet film coercivity origin

A new annealing method which drastically reduces the coercivity of GaGe-garnet films grown by LPE has been developed. The as-grown films of (YSmLuCa)₃(FeGe)₅O₁₂ and (YEuTmCa)₃(FeGe)₅ O₁₂ are sealed with Y₂O₃ and metal Ca in an evacuated tube having three chambers. When heated, the tube is filled with Ca and O₂ gases which are supplied from the metal Ca and Y₂O₃, respectively. Ca and oxygen are believed to be incorporated into the film occupying the dodecahedral cation vacancies and oxygen vacancies, respectively. By this annealing, coercivities higher than 5.0 Oe are drastically reduced to less than 0.5 Oe. At the same time, the 4πMs and lattice constant af are decreased, while the Curie temperature T_c is increased. A point defect structure model containing c-site vacancies, oxygen vacancies and a-site Ge²⁺ ions is proposed. The origin of the coercivity is believed to be the oxygen vacancies.     

Application of rigid polyurethane integral-skin foams to thermal insulating unit cases for car air conditioners

Integral-skin foams of rigid polyurethane are sandwich structures consisting of a core layer of closed cells enclosed in rigid surface layers on both sides. We examined the layer composition of integral-skin foam with the objective of maximum flexural strength, and then studied possibilities of reconciling the strength and thermal insulating properties in housings for evaporators in car air conditioners; i.e., unit cases. This examination showed that the most practical density range (250 ≦ ρ_pall ≦ 500 kg/m³) provides vibratile resistance and thermal insulating properties. In actual car-running tests, a maximum 0.1 MPa stress was generated on unit cases with overall densities of 350 kg/m³, We found this to be 0.4% of the flexural strength of an integral-skin foam and 2% of the fatigue strength. In the forcible vibratile test, a stress of 0.5 to 1.0 MPa was generated at the resonance point of a unit case with 250 to 500 kg/m³ overall density. We found that these values are 2 to 5% of integral-skin foam's flexural strength and 10 to 25% of its fatigue strength. These values are of the same level as the conventional unit case made of polypropylene blended with talc. An integral-skin foam with an overall density of 250 kg/m³, nearly equal to half the weight of polypropylene, has the same level of resistance to vibration.     

Additivity failure of chromatic valence in the opponent-color theory

The additivity of flicker responses produced by two different wavelengths λ₁ and λ₂ was investigated for five adapting levels of 560 nm by the summation-index method. A summation-index value of σ of 0.30 was obtained for all conditions employed, confirming the linear property of the achromatic channel. The additivity of unique chromatic responses, red, yellow, green, and blue, was also investigated with the same method. In this case the wavelengths λ₁ and λ₂ were chosen in a spectral region to produce one of the four unique colors and the summation index was measured for the color with the cancellation method. A summation index of 0.30 was found for the green and blue sensations and also for the red sensation if both stimuli were from the same spectral region. A slight additivity failure of the enhancement type was found for pairs λ₁ and λ₂ λ₁ was in the short-wavelength region while λ₂ was in the long-wavelength region. An additivity failure of the same type was found for the yellow chromatic sensation when λ₂ was 607 nm and λ₁ was 570, 550, or 533 nm, the last combination giving a summation index of as much as 0.64. The results imply the existence of two different cones whose responses do not add linearly to yield the yellow sensation.