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Electron emission properties of Spindt-type platinum field emission cathodes were investigated. The current–voltage characteristics together with the current fluctuation during long term operation were evaluated in ultrahigh vacuum. The changes of the emission properties in hydrogen, oxygen or carbon monoxide gas ambient were also investigated. Significant improvement of the emission properties was found when the cathode was operated in carbon monoxide ambient under a certain condition. It was found that the effect of the improvement lasted at least 200 h, and resistance against the oxygen exposure was also improved. The changes of the electron emission properties during long term operation in ultrahigh vacuum and in gas ambient were analyzed with the Seppen–Katamuki chart, of which ordinate and abscissa are slope and intercept of Fowler–Nordheim plot. The electron emission properties were distributed along a straight line in the Seppen–Katamuki chart, and those of the cathode improved by carbon monoxide exposure were distributed along another line. The deviation of the electron emission property in ultrahigh vacuum was considered to be due to change in the geometry of the emitting surface. The major reason for the modification of electron emission properties in carbon monoxide ambient was considered to be deposition of carbon onto the emitting surface, resulting in reduction of the work function. From the deviation of the Fowler–Nordheim characteristics in the Seppen–Katamuki chart, we presented an empirical equation for field emission. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The inspection of the hardened depth of surface-hardening steel is important in the maintenance of various mechanical parts, and for other purposes as well. There is a difference in the electromagnetic properties in the layers with and without hardening. Therefore, the evaluation of the hardened depth is possible by detecting the difference in the electromagnetic characteristics. In this paper, the electromagnetic method for measuring the depth of a hardened layer using an alternating magnetic field of low frequency is proposed. The flux density in the surface-hardening steel is estimated by a 3-D nonlinear finite-element method taking account of the hysteresis characteristics of the layers with and without hardening. In addition, the experimental verification is also carried out. [ABSTRACT FROM AUTHOR]

Steel tubes are used in the heat exchanger in the petrochemical plant or the steam generator in the fast breeder reactor. Since these steel tubes in the heat exchanger or steam generator are stored as a bundle by the support steel plate (baffle), it is necessary to inspect the existence of defects from the inside of each tube. In these steel tubes, the defects are generated between the steel tube and the baffle at the outer side of steel tube. In this paper, problems in applying the alternating flux leakage testing method for the inspection of the outer side defect on steel tube with the baffle are examined using 3-D nonlinear FEM. Moreover, the differential type search coils that detect the leakage flux from the outer side defect on steel tube are proposed. The optimal dimension of the differential search coils is determined using the Rosenbrock's method or the evolution strategy. [ABSTRACT FROM PUBLISHER]

Steel tubes are used in the heat exchanger in the petrochemical plant. Since these steel tubes in the heat exchanger are stored as a bundle, it is necessary to inspect the defects of these tubes from the inside of tube. In this paper, problems in applying the alternating flux leakage testing method for the inspection of the outer side defect on steel tube are examined using 3-D finite element method. The features of detecting property of outer side defect using an inner coil at low-frequency are investigated by analyzing the flux and current distribution. It is shown that the inspection of the outer side defect on a steel tube with cooling aluminum fin is possible using the proposed method. [ABSTRACT FROM AUTHOR]

Abstract: Erosion and redeposition profiles of carbon tiles used in the W-shaped divertor of JT-60U with all carbon plasma facing wall are studied. The inner divertor is mostly covered by carbon redeposited layers, while the outer divertor mostly eroded. In the dome region, the erosion dominates on the inner dome-wing, while redeposited on the outer dome-wing. The redeposited layers on the outer dome-wing show very clear columnar structures indicating local carbon transport form the outer divertor to the outer dome-wing. The weight gain by the redeposition extrapolated to the whole divertor area is 0.55kg. Since the extrapolated total erosion is about 0.33kg, the remaining 0.22kg must be originated from the main chamber erosion. Significant amount of the redeposition is caused locally by multiple processes of erosion, ionization and prompt redeposition toward inboard direction owing to gyration along magnetic filed line. This inboard transport is one of the reasons for small redeposition on the plasma shadowed area of the W shaped divertor of JT-60U with pumping slots placed at the bottoms side. [Copyright &y& Elsevier]

Abstract: Temperature dependence of atomic modulation in the incommensurate composite crystal structure of (Sr2Cu2O3)0.70CuO2, ‘Sr14Cu24O41’ with two-legged Cu2O3 ladder and edge-shared CuO2 chain has been investigated by single-crystal X-ray diffraction method using centrosymmetric (3+1)-dimensional superspace group. The displacive modulations of all constituent atoms at 150K have been compared with those obtained at room temperature. The hole distribution between the Cu2O3 ladder plane and the one-dimensional CuO2 chain has been considered on the basis of the changes of lattice constants of incommensurate basic structure, the role of the atomic modulation and the interatomic distances between Cu atom in the Cu2O3 and O atom in the CuO2. It is indicated that the small amount of holes doped in the Cu2O3 ladder have been back-transferred to the CuO2 chain and that almost all of the holes in (Sr2Cu2O3)0.70CuO2 are localized in the CuO2 at low temperature. [Copyright &y& Elsevier]

Abstract: Work functions of rf-magnetron sputter-deposited transition metal nitride and carbide thin films, including TiN, HfN, VN, NbN, TaN, HfC, VC, NbC, TaC, , and WC, were measured by Kelvin probe in air. Thin films of the above materials were prepared on (100)-oriented silicon substrate by rf-magnetron sputtering of a compound target. As a result, it was found that the work function of nitride was similar to or slightly lower than that of carbide. For nitride films, those with heavier metal atoms such as Hf and Ta, showed lower work function. The work function depended upon the Period to which the metal atom belongs in the periodic table. [Copyright &y& Elsevier]

Abstract: Thermal properties of the redeposition layer on the inner plate of the W-shaped divertor of JT-60U have been measured with laser flash method so as to estimate transient heat loads onto the divertor. Morphology analysis of the redeposition layer was conducted with a scanning electron microscope. Measurement of a redeposition layer sample of more than 200μm thick, which had been produced near the most frequent striking point, showed following results: (1) the bulk density of the redeposition layer is about half of that of carbon fiber composite material; (2) the specific heat of the layer is roughly equal to that of the isotropic graphite; (3) the thermal conductivity of the redeposition layer is two orders of magnitude smaller than that of the carbon fiber composite. This low thermal conductivity of the redeposition layer is considered to be caused by a low graphitization degree of the redeposition layer. The difference between the divertor heat loads and the loss of the plasma stored energy becomes smaller taking account of thermal properties of the redeposition layer on the inner divertor, whereas estimated heat loads due to the ELMs is still larger than the loss. This is probably caused by the poloidal distribution of the thermal properties. [Copyright &y& Elsevier]

It is known that the detection of cracks on the outer side of steel plate is possible using the dc flux leakage testing. If the examined steel plate is thin, the outer side crack may be detected by alternating flux leakage testing. The merit of the alternating flux leakage testing method is that a cheap coil is used for detecting the leakage flux from the crack. In this paper, the inspection method of outer side crack of the steel plate using the alternating flux leakage testing is proposed. The component [Bx] of the leakage flux parallel to the surface of steel is utilized for detecting the crack. The behavior of leakage flux is examined using a three-dimensional edge-based hexahedral FEM (finite element method). It is shown that the outer side crack can be inspected by detecting the parallel (x-) component of leakage flux. [ABSTRACT FROM AUTHOR]

Abstract: Single-crystal X-ray structure analysis of mutually incommensurate (Ca0.5Y0.5)0.80CuO2, “Ca2Y2Cu5O10” has been performed by the composite approach which leads to average substructures and their relative arrangement. The composite crystal structure of (Ca0.5Y0.5)0.80CuO2 has the CuO2 substructure and the Ca0.5Y0.5 substructure. The CuO2 substructure with a 1 =10.598(2) Å, b =6.189(2) Å, c 1 =2.825(2) Å, β 1 =90.19(4)°, V 1 =185.4(1) Å3, Z =4 and space group F2/m has the plane of edge-shared one-dimensional CuO2 chains along the c-axis. The Ca0.5Y0.5 substructure with a 2 =10.629(2) Å, b =6.189(2) Å, c 2 =3.517(1) Å, β 2 =94.36(3)°, V 2 =230.7(1) Å3, Z =4 and space group F2/m forms the sheet of (Ca, Y) atoms in the ac-plane. By considering (3+1)-dimensional superspace group symmetry, it is concluded that the incommensurate composite crystal structure of (Ca0.5Y0.5)0.80CuO2 should be described by the combination of F2/m for the CuO2 substructure and F2/c for the Ca0.5Y0.5 substructure. The composite approach has made clear that the plane of CuO2 chains and the sheet of (Ca, Y) atoms stack alternately to form a mutually incommensurate composite crystal with layered substructures. [Copyright &y& Elsevier]

Abstract: Role of atomic modulation in the incommensurate composite crystal structure of (Sr2Cu2O3)0.70CuO2, “Sr14Cu24O41” has been investigated by four-dimensional superspace group approach. It has become apparent that the displacive modulations of Sr and O atoms are effective for the stabilization of alternate stacking of the planes of the Cu2O3 ladder and the CuO2 chain. The Cu–O bonds in both of the modulated and unmodulated structures have been investigated to understand the origin of electronic and magnetic properties. In the average structure, it has been clarified that considerable amount of holes are generated in the CuO2 chain. In the course of the modulated structure analysis, the Cu–O bond in the CuO2 chain has become tilt toward the Cu2O3 ladder in order that the O atom in the chain acts as apical oxygen for the ladder plane. By the large modulation of the O atom in the CuO2 chain, the prepared holes are distributed to make the hole-ordered structure in the CuO2 plane. [Copyright &y& Elsevier]

Abstract: We propose use of silicon field emission array as a novel charge neutralization device for ion implanter. Fundamental characteristics of the emitted electrons, i.e. energy distribution and operation in high vacuum were investigated. As a result, energy spread was narrow enough but unexpected energy peak shift was observed. To reduce the energy spread and peak shift, a FEA with less number of tips and with narrower gate diameter is necessary. The FEA could be operated about 100h in high vacuum. [Copyright &y& Elsevier]

Single composite crystals of (BiS)xTS2-type ternary chalcogenides (T=V, Nb and Ta) with layered substructures have been prepared by chemical-vapor transport method with NH4Cl as transport agent. The mutually incommensurate composite crystal structures of (BiS)xTS2 have been successfully characterized by the X-ray diffraction and the convergent beam electron diffraction methods using (3+1)-dimensional superspace group symmetry. Temperature dependences of in-plane electrical resistivity of single composite crystals of (BiS)xTS2 have been measured by a standard d.c. four probe method in the range of 1.7–300 K. It has been suggested that the electronic transport properties of (BiS)xTS2 compounds are metallic below room temperature. [Copyright &y& Elsevier]

The enzyme-linked immunospot (ELISPOT) assay is an efficient technique for the enumeration of single cells secreting antibodies and cytokines. For simultaneous differentiation of individual cells producing interleukin-2 (IL-2) and interleukin-4 (IL-4) at a single cell level in human peripheral blood mononuclear cells (PBMCs), a human dual-color ELISPOT assay has been optimized. In the present system, the red spots corresponding to IL-2-secreting cells (T helper type 1, Th1, cells) were developed with horseradish peroxidase and the amino ethyl carbazole (AEC)/H2O2. The blue spots corresponding to IL-4-secreting cells (T helper type 2, Th2, cells) were developed with an alkaline phosphatase and the Vector blue. The usefulness of the assay method was tested. With this system, we could detect the IL-2- and IL-4-secreting cells simultaneously in human PBMCs of a juvenile rheumatoid arthritis (JRA) patient. This procedure provides useful information on clinical immune disorders. [Copyright &y& Elsevier]

The stability of the electronic perturbations (EPs) on a graphite surface produced by low-energy argon ion bombardment was investigated. The ion bombardment was performed using an ion irradiation system consisting of a compact microwave ion source directed to the observation site for scanning tunneling microscopy. We measured the change in the number of the EPs upon repetitive ion bombardment and found that the numbers saturated with the ion dose. Similar experiments were made for a carbon ion-bombarded sample, but the number increased in proportion to the ion dose. Long-time observations of the surface after ion bombardment revealed that the number of EPs gradually decreased for the case of argon ion-bombarded sample. The experimental results suggest that desorption of argon may contribute to the decrease of the EP. [Copyright &y& Elsevier]

The effect of Bi doping on the modulated composite structure of (Sr2Cu2O3)0.70CuO2 has been extensively investigated on the basis of (3+1)-dimensional superspace group approach. By applying the bond-valence-sum method for the modulated composite structure, it has become apparent that the valence state of the Cu atom in any sites of the Cu2O3 ladder in (Sr2−xBixCu2O3)0.70CuO2 is maintained divalent. The interatomic distance between the Cu atom in the two-legged Cu2O3 ladder and the O atom in the CuO2 chain becomes larger with Bi doping, in spite of the slight shrinkage of lattice dimension along the stacking direction. The hole transfer from the CuO2 chain to the Cu2O3 ladder in (Sr2Cu2O3)0.70CuO2 is depressed by the effect of Bi doping on the atomic modulations. [Copyright &y& Elsevier]

The effect of Bi doping on the modulated composite structure of (Sr2Cu2O3)0.70CuO2 has been extensively investigated on the basis of (3+1)-dimensional superspace group approach. By applying the bond-valence-sum method for the modulated composite structure, it has become apparent that the valence state of the Cu atom in any sites of the Cu2O3 ladder in (Sr2−xBixCu2O3)0.70CuO2 is maintained divalent. The interatomic distance between the Cu atom in the two-legged Cu2O3 ladder and the O atom in the CuO2 chain becomes larger with Bi doping, in spite of the slight shrinkage of lattice dimension along the stacking direction. The hole transfer from the CuO2 chain to the Cu2O3 ladder in (Sr2Cu2O3)0.70CuO2 is depressed by the effect of Bi doping on the atomic modulations. [ABSTRACT FROM AUTHOR]

The relationship between composition and work function of gold–samarium alloy thin films were investigated. The Au–Sm thin films were deposited by rf magnetron sputtering apparatus. The surface composition of the films were evaluated by X-ray photoelectron spectroscopy, and the work function of the films were evaluated by a Kelvin probe. The result showed the non-linear relation between the work function and composition. We considered that the characteristics were due to the segregation of Au in low Au composition and applied to the Yamamoto''s results in the region between 10 and 50 at%. No significant reduction of the work function was observed. Nevertheless, we could control the work function from approximately 3.5–5.3 eV by alloying. [Copyright &y& Elsevier]

In order to explain the atomic arrangement of fcc metals with 1 ML thickness deposited on bcc(1 1 0) surface, such as Mo and W, the calculation of the interfacial energy between the fcc(1 1 1) monolayer and the bcc(1 1 0) surface was carried out using the Morse potential. Interactions of deposited fcc atoms with neighboring fcc atoms on the surface and with Mo atoms of the substrate within a constant distance were considered. First, the interfacial energy of the structure with a rigid fcc(1 1 1) monolayer on the substrate was calculated by varying the relative rotation angle and the atomic diameter ratio of bcc to fcc. The calculations showed that the energy minimum appears at Nishiyama–Wassermann and Kurdjumov–Sachs orientations at specific values of the atomic diameter ratio, which can be used to predict epitaxial orientation for various fcc/bcc combinations. Second, the calculations can interpret surface superstructures such as the 10×4 structure appearing in the Pb monolayer deposited on the Mo(1 1 0) surface with a coincident site lattice structure deformed slightly from the fcc(1 1 1) plane, as observed by RHEED experiment. [Copyright &y& Elsevier]

Background: The regulation of intestinal cell death by luminal factors is poorly understood. The objectives of this study were to determine whether a diurnal rhythm of intestinal apoptosis exists, and to determine the role that feeding and fasting play in this process. Methods: Mucosal apoptotic death was measured in fed and 24-h fasted rats and at various times after feeding by DNA fragmentation and in situ immunohistochemical staining (TUNEL). Results: In 24-h fasted rats, 32% of total mucosal DNA was fragmented as compared to 9% in fed animals. In both jejunal and ileal segments, the fragmented DNA exhibited characteristic apoptotic DNA ladders on agarose gels. Immunohistochemical staining revealed significant location of apoptotic cells at the upper third of the intestinal villus. In the duodenum, DNA fragmentation at 6-12 h post feeding was 20% and decreased to 4% at 24 h. In comparison, DNA fragmentation in the jejunum and ileum was low from 0 to 6 h post feeding (2%-9%) and significantly increased at 12 h (18% versus 12%) and 24 h (30% versus 32%), respectively. These results are consistent with a temporal relationship between percent fragmented DNA and time after feeding with greater cell death at longer fasting period. A postprandial rhythm of DNA fragmentation was evident in the jejunum and ileum, in which fragmentation was at a peak between 0900 h and 1200 h. Conclusion: Collectively, the data show that initiation of apoptosis in apical enterocytes is coincident with cessation of feeding and commencement of fasting, and is consistent with a rhythm of programmed cell death in these cells that parallels the cyclical pattern of feeding and fasting. [ABSTRACT FROM AUTHOR]

Deals with the application of a compact microwave ion source to the low temperature growth of transition metal nitride thin films for the cathode of vacuum microeletronics devices. Ion beam assisted deposition of transition metal nitrides; Film property; Electron binding energy; Endurance against low energy ion bombardment.

The possibility that the peanut agglutinin (PNA) receptor and/or its co-ordinate structures on the surface of leukaemia cells might be recognized by lectin free crude interleukin-2 (IL-2) activated human peripheral blood lymphocytes (LAK) was investigated. Analysis was undertaken of the correlation between the sensitivity to allogeneic LAK lysis and the proportion of PNA receptor on different fresh malignant cells. The results obtained suggested that PNA receptor detected by rhodamine isothiocyanate labeled PNA binding assay appeared to be well expressed on leukaemia cells which were sensitive targets for LAK, PNA receptor and/or its coordinate structures seemed to provide a 'target' structure for LAM. [ABSTRACT FROM AUTHOR]

Reports on the development of a metal ion beam self-sputter deposition system which requires no gas feeding, for film preparation under ultrahigh vacuum. Metal ion beam self-sputter deposition system; Deposition and characterization of the films; Angular distribution of sputtered particles.

To obtain high-flux hydrogen atoms equivalent to the irradiation condition at the surface of the first-wall or divertor plate in a nuclear fusion reactor, a new microwave ion source was constructed and its operation was demonstrated. The source was designed so that H3+ ions are efficiently produced through the ion-molecule reaction between H2+ ions and H2 molecules. Extracted ion beams were mass analyzed and pure H3+ ions were introduced into the ultrahigh-vacuum target chamber. The obtainable irradiation current of H3+ ions was 1.5 mA at 3 keV. The beam diameter at the target was about 1 cm. Maximum flux density of hydrogen atoms at an energy of 1 keV exceeded 4×1016 H/cm2 s, which is high enough for plasma-wall interaction studies. [ABSTRACT FROM AUTHOR]

Two severe combined-immunodeficiency patients successfully transplated with fetal thymus and liver or haploidentical lectin-treated marrow cells lacked NK activity, with a normal number of HNK1+ cell-defined NK cells. The defect was not due to the inhibiting factor in patients' sera. Their NK cells bound to their targets, but did not lyse them in a single-cell agarose assay, and did not respond to α-IFN or IL-2, IL-2 did not stimulated the development of mature NK cells that bear MI antigens from precursors that lack MI antigens. [ABSTRACT FROM AUTHOR]

Demonstrates that a `Xenopus' kinase, closely related to the mitogen-activated mammalian MAP kinase, is phosphorylated and activated during M phase of meiotic and mitotic cell cycles. Methods; Results; Discussion.

There is a need to inspect the thickness of a nickel layer of nickel-coated steel, which is used to prevent rust, in the production process to guarantee the quality. Although an X-ray measurement is generally used, the protection wall of X-ray is necessary in the inspection equipment. Since the equipment of the electromagnetic inspection is cheap and simple compared with an X-ray equipment, the inspection of the thickness using the electromagnetic method is examined. In this paper, the electromagnetic method for measuring the thickness of a nickel layer using an alternating magnetic field is proposed. The detailed phenomenon of the measurement method is examined using the 3-D edge-based hexahedral nonlinear finite-element method (FEM). It is shown that the electromagnetic inspection of the thickness of nickel layer is possible by using the property that the flux density in nickel-coated steel is reduced when the thickness of nickel layer is increased. The FEM analysis is verified by experiment. [ABSTRACT FROM AUTHOR]

A method for deriving the length of carbon nanotube (CNT) in field emission arrays is proposed. Unlike the direct method of observation using a microscope, this method gathers information from functional measurements. Electron emission characteristics of CNT’s printed on glass substrate were measured in a diode configuration. The macroscopic part of the voltage field conversion factor β was obtained from the relationship between the slope and intercept of the Fowler-Nordheim plot, and also from modeling of the electrodes. The length of the CNT was derived comparing the two values for β. The estimated length of the CNT agrees with direct measurements. [ABSTRACT FROM AUTHOR]

Since the cast iron is used for the parts of various heavy machines, the hardness of it should be high. The hardness is rapidly reduced by the appearance of the retained austenite in the cast iron. Therefore, the inspection of volume fraction of retained austenite in the cast iron is important. The B-H curve and the conductivity of the cast iron containing the austenite are different from those of the normal cast iron. Then, the detection of retained austenite is possible by measuring the change of electromagnetic properties using an electromagnetic inspection method. In this paper, the electromagnetic inspection technique of retained austenite in the cast iron is examined using 3-D edge-based hexahedral nonlinear FEM (finite element method). The possibility of detecting the retained austenite using the proposed inspection method is illustrated. In addition, the experimental verification is also carried out. [ABSTRACT FROM AUTHOR]

The inspection of rust region in steel is important in the petrochemical plant, etc. The B-H curve and the conductivity of rust region in steel are different from those of the normal steel. Then, the detection of rust region in steel is possible by detecting the difference of those electromagnetic properties using an inspection method. In this paper, those electromagnetic properties of the rust region in steel are measured utilizing three-dimensional (3-D) axis-symmetric finite-element method (FEM) and experiment. The electromagnetic inspection technique of the rust region is examined using 3-D edge-based hexahedral nonlinear FEM. The possibility of detecting the rust region using the proposed inspection system is illustrated. In addition, the experimental verification is also carried out. [ABSTRACT FROM AUTHOR]

Nanostructured heterogeneous HfN[sub x]O[sub y] films comprising of nanoscale conductive hafnium nitride grains embedded in a matrix of dielectric oxide or oxynitride were deposited on silicon substrate by magnetron sputtering at room temperature. Electron emission with low threshold field 25 V/μm and good current stability were reported. The field emission characteristics depend on the concentration of hafnium nitride phase, revealing the nature of heterogeneous structure. Field enhancement in HfN[sub x]O[sub y] film was explained in terms of the interaction between the conductive grains separated by dielectric layers under external electric field. The experiment is expected to open a group of nanostructured heterogeneous material consisting of stable conductive nitride and insulating oxide for field emitter, and also provide an insight into the emission mechanism of carbon films. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Tantalum nitride thin films were prepared by ion beam assisted deposition technique. Depositions were performed at some different ion-atom arrival rate ratio, and the film properties such as nitrogen composition, crystallinity, and work function were investigated. The relation between ion-atom arrival rate ratio and nitrogen composition was quite similar to that of niobium nitride, which was investigated previously. The structure of the present films was amorphous from X-ray diffraction analysis. The work function slightly decreased with an increase in the nitrogen composition. This result is also similar to that of niobium nitride. The absolute value of the work function was similar to or slightly higher than that of niobium nitride. [Copyright &y& Elsevier]

The energy distribution of the ion beam extracted from the compact microwave ion source for extremely low voltage ion extraction was measured with Ar and CO as a discharge gas. The energy distribution was measured by the retarding field method, and changes with respect to the change in gas pressure were observed. The obtained data were arranged by the peak energy and the energy spread. For both gases, the peak energy and the energy spread decreased with an increase in the gas pressure. The energy spread of approximately 5 eV with the peak energy of 15 eV were obtained for Ar gas at the pressure of 10[sup -2] Pa. For CO gas, the peak energy was higher than Ar and approximately 20 eV. The energy spread was 6 eV at the pressure of 10[sup -2] Pa. These values agreed with the peak energy and energy spread that were estimated previously from the mass spectra analysis. Since the ion source was designed to be used in the researches of low energy ion-solid interaction, these characteristics satisfy the requirements for this purpose. [ABSTRACT FROM AUTHOR]

Focuses on measurement of performance of a compact microwave ion source developed for extremely low energy ion extraction. Characteristics of ion source; Current-voltage characteristics; Estimation of ion energy; Estimation of energy spread.

Proposes a criterion for decrease of electric field at the ionization point of liquid-metal ion sources. Dependence of electric field on source current based on postionization theory; Space-charged limited current with small charge approximation; Dependence of emission current and current density on electric field.

Deals with the performance of a molecular ion implanter equipped with a liquid-metal alloy ion source. Configuration of ion implanter; Evaluation of optics; Separation of molecules; Molecular ion implantation.

Develops a compact microwave ion source for low-energy application. Influence of plasma density on the extraction of ions; Presence of a plasma expansion cup in the ion source; Measurement of the current-voltage characteristics of the ion source.

A new type of impregnated-electrode-type liquid-metal ion source, which eliminated the heating problem in the previous source, has been developed with multiple tip and reservoirs (TAR's). In the present ion source, the TAR's are connected electrically in series by modifying the TAR holding system. In order to achieve uniform heating of the TAR's, the materials of the knife-edged electrodes, which introduce the heating current to the TAR's, were examined. Tantalum electrodes exhibited better results as compared with the conventional Mo electrodes. Both of the two TAR's could be heated up to 700 °C with a heating power of 200 W. The maximum indium ion current of 9.1 mA was obtained from the four-TAR source with 40 emission points. Since the present ion current was limited by the current capacity of the extraction power supply, an ion current of more than 10 mA will be expected with a larger power supply. The results indicated that an ion current approximately proportional to the number of the emission points was obtained. This kind of ion source could be used as a general ion source in materials science. [ABSTRACT FROM AUTHOR]

The interaction of HCl with the D2O-ice surface has been investigated in the temperature range 15–200 K by utilizing time-of-flight secondary ion mass spectroscopy, temperature-programmed desorption, and x-ray photoelectron spectroscopy. The intensities of sputtered H+(D2O) and Cl- ions (the H+ ions) are increased (decreased) markedly above 40 K due to the hydrogen bond formation between the HCl and D2O molecules. The HCl molecules which form ionic hydrates undergo H/D exchange at 110–140 K and a considerable fraction of them dissolves into the bulk above 140 K. The neutral hydrates of HCl should coexist as evidenced by the desorption of HCl above 170 K. They are incorporated completely in the D2O layer up to 140 K. The HCl molecules embedded in the thick D2O layer dissolve into the bulk, and the ionic hydrate tends to segregate to the surface above 150 K. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

For non-destructive inspection of ferromagnetic pipes using magnetic flux leakage (MFL), a sensor consisting of two coils to measure the discrete Fourier sine and cosine coefficients of MFL is developed. The position of a crack in a pipe can be estimated from the squared sum and the ratio of the voltages induced in the two coils. Each coil has sixteen elemental coils with 78 permalloy cores which are placed along a circle with a radius of 6.3mm and connected in series. The number of turns comprising an elemental coil at an angle ϕ is proportional to sin ϕ in one coil and proportional to cos ϕ in the other. It was experimentally shown that a circular crack 4mm in diameter in a ferromagnetic pipe with diameter 21.6mm was localized. The proposed structure is suitable for narrow pipe inspection where the sensitivity of our previous sensor composed of two coaxial crescent-shaped coils decreases [ABSTRACT FROM AUTHOR]

Aims: To evaluate the protective effects of oral administration of milk fermented with a Lactococcus strain against influenza virus (IFV) infection in a mouse model. Methods and Results: Milk fermented with exopolysaccharide-producing Lactococcus lactis subsp. cremoris ( L. cremoris) FC was orally administered to BALB/c mice for 12 days. Mice were intranasally infected with IFV A/New Caledonia/20/99 (H1N1) on day 8, and survival was determined for 14 days after IFV infection. Survival rate and body weight loss after IFV infection in the L. cremoris FC fermented milk-administered group were significantly improved compared with those in the control group. In the unfermented milk-administered group, survival rate was not improved, whereas body weight loss was slightly improved compared with that in the control group. The mean virus titre in the lung of the L. cremoris FC fermented milk-administered group 3 days after infection was significantly decreased compared with that in the control group. Conclusions: These results suggest that oral administration of milk fermented with L. cremoris FC protects mice against IFV infection. Significance and Impact of the Study: These results demonstrate that oral administration of milk fermented with exopolysaccharide-producing Lactococcus strains might protect host animals against IFV infection. [ABSTRACT FROM AUTHOR]

Abstract: Single-crystal X-ray structure analysis of mutually incommensurate (Sr0.36Ca1.64Cu2O3)0.706CuO2, “Sr2.5Ca11.5Cu24O41” has been performed on the basis of superspace group approach. The lattice constants of (Sr0.36Ca1.64Cu2O3)0.706CuO2 are a =1.1298(1), b =1.2582(1), for the CuO2 part and a =1.1298(1), b =1.2582(1), for the (Sr0.36Ca1.64Cu2O3) one. From the average structure analysis, it has been expected that the formation of CuO5 with pyramidal coordination by O atoms occurs in the Cu2O3 ladder. The minimum distance between Cu atom in the Cu2O3 ladder and O atom in the CuO2 chain has clearly shown that O in the CuO2 acts as apical oxygen to form the CuO5 coordination. It has been concluded that (Sr0.36Ca1.64Cu2O3)0.706CuO2 bears a marked structural resemblance to the cuprate High superconductors. [ABSTRACT FROM AUTHOR]

The emission property of a Spindt-type platinum field emitter was greatly improved by operating in carbon monoxide ambient with appropriate operating parameters. After sufficient aging, the emitter was operated in carbon monoxide ambient up to 10[sup -3] Pa, at the emission current of 1 μA. The emission current first decreased in accordance with the gas introduction, but turned to show rapid increase when the gas pressure was increased to 10[sup -3] Pa. The current stability, as well as the operating voltage, was improved by this treatment. The apex of the emitter was examined with the Seppen-Katamuki analysis technique, in which detailed information on the emission area and effective work function can be read from the diagram plotted with the intercept and slope of a Fowler-Nordheim plot. The analysis suggested reduction of the effective work function is a major reason for the improvement of the emission property. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The gray cast iron is used in many machine parts such as pulleys, since it has excellent vibration damping, wear resistance, and castability. Material evaluation of this cast iron is important for quality assurance of machine products. This research proposes a method to identify defective products mixed with good products. Currently, test methods such as Brinell hardness and tensile strength tests are commonly used to check the quality of cast irons. However, these methods are not suitable for inspecting all products in terms of time required. Therefore, it is important to establish an electromagnetic nondestructive test that enables non-contact and fast measurement. It has been found that the use of AC magnetic fields in nondestructive testing methods can be used to measure defective gray cast iron. In this paper, we propose an electromagnetic nondestructive testing method that uses a DC-biased sinusoidal magnetic field, which enables measurements with higher sensitivity than those obtained with AC magnetic fields. The effectiveness of the proposed method is demonstrated through electromagnetic field finite element method (FEM) analysis using the play model method and corroborated by verification experiments. [ABSTRACT FROM AUTHOR]

Spheroidal graphite cast iron is often used for machine parts that require high strength. A shrinkage cavity may be generated inside the cast iron during the manufacturing process. If there is a shrinkage cavity in the cast iron, the strength of the cast iron is significantly reduced. In this article, a non-destructive testing method for detection of shrinkage cavity inside the cast iron by constant frequency vibration measurement using electromagnetic force excitation at low frequency is proposed. In this method, the electromagnetic force vibration is generated inside the cast iron from the static magnetic field by a permanent magnet and the eddy current by an alternating exciting coil. Then, the vibration is measured by an accelerometer that is in contact with the surface of the cast iron material. If there is a shrinkage cavity inside the cast iron, since the vibration intensity is changed, the shrinkage cavity is estimated by the vibration measurement. In this method, the shrinkage cavities inside cast iron can be inspected at high speed with an inexpensive device. In this article, the electromagnetic force vibration is calculated using the 3-D nonlinear electromagnetic finite element method (FEM) analysis. The displacement due to vibration in the cast iron is calculated by the 3-D displacement FEM analysis. The phenomenon of electromagnetic force excitation is clarified using these FEM analysis methods. Then, the effectiveness of the proposed inspection method is investigated by comparing the results of the verification experiment and analysis. [ABSTRACT FROM AUTHOR]

Highlights: [•] The role of chromatin modification in NPC sequential fate switches. [•] The role of chromatin modification in neuronal differentiation. [•] Chromatin structure and DNA/histone modifications change during development. [•] Some modifications not only occur at specific gene loci, but also on a global scale. [ABSTRACT FROM AUTHOR]

The transcription factor E2F1 has pivotal roles in both cell proliferation and cell death, and is an important molecular target in cancer. Under proliferative conditions E2F1 induces the expression of genes that promote cell cycle progression, such as E2F2, whereas under proapoptotic conditions E2F1 induces expression of genes such as p73 that lead to apoptosis. The mechanism by which the apoptotic function of E2F1 is activated remains unclear, however. We now show that members of the E2F family are covalently conjugated with the ubiquitin-like modifier NEDD8. Overexpression of SENP8, a NEDD8-specific cysteine protease, resulted in deNEDDylation of E2F1 and promoted its transactivation activity at the p73 gene but not at the E2F2 gene. Knockdown of SENP8, on the other hand, attenuated p73 expression and apoptosis induced by E2F1 or by DNA damage. SENP8 also promoted the interaction between E2F1 and its cofactor Microcephalin 1, which is required for p73 induction. These results suggest that NEDDylation is a molecular trigger that modifies the target specificity of E2F1, and could have important implications for E2F1 regulation of apoptosis. [ABSTRACT FROM AUTHOR]

Abstract: The properties of water, ethanol and 1-butanol at cryogenic temperatures (10–220K) are discussed by investigating the interaction with the C6F14 molecule. The C6F14 molecules adsorbed on the surface are incorporated in the bulk of the glassy water and alcohol films. The wettability may arise from the formation of improper hydrogen bonding between the OH group and F atom. On the alcohol films, the incorporated C6F14 molecules segregate to the surface at 100K, since the hydrogen-bonded rings and chains of alcohols are formed due to the glass–liquid transition. The C6F14 molecules incorporated in the bulk of amorphous solid water can survive a viscous liquid phase that appears above 136K and desorb abruptly at 167K as a consequence of the liquid–liquid transition. [Copyright &y& Elsevier]