bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancing Virtual Product Representations for Advanced Design Repository Systems
Authors: Bohm Matt R. , Stone Robert B. , Szykman Simon
Published: November 2005

This paper describes the transformation of an existing set of heterogeneous product knowledge into a coherent design repository that supports product design knowledge archival and web-based search, display, and design model and tool generation. Guided by design theory, existing product information was analyzed and compared against desired outputs to ascertain what information management structure was needed to produce design resources pertinent to the design process. Several test products were catalogued to determine what information was essential without being redundant in representation. This set allowed for the creation of a novel single point of entry application for product information and the development of a relational database for design knowledge archival. Web services were then implemented to support design knowledge retrieval through search, browse, and real-time design tool generation. Further explored in this paper are the fundamental enabling technologies of the design repository system. Additionally, repository-generated design tools are scrutinized alongside human-generated design tools for validation. Through this process researchers have been able to improve the way in which artifact data are gathered, archived, distributed and used.
Communication-Free Streaming Mesh Refinement
Authors: Pébay Philippe P. , Thompson David
Published: November 2005

This article presents a technique for the adaptive refinement of tetrahedral meshes. What makes this method new is that no neighbor information is required for the refined mesh to be compatible everywhere. Refinement consists of inserting new vertices at edge midpoints until some tolerance (geometric or otherwise) is met. For a tetrahedron, the six edges present 26=64 possible subdivision combinations. The challenge is to triangulate the new vertices (i.e., the original vertices plus some subset of the edge midpoints) in a way that neighboring tetrahedra always generate the same triangles on their shared boundary. A geometric solution based on edge lengths was developed previously, but did not account for geometric degeneracies (edges of equal length). This article provides a solution that works in all cases, while remaining entirely communication-free.
Efficient Handling of Implicit Entities in Reduced Mesh Representations
Authors: Celes Waldemar , Paulino Glaucio H. , Espinha Rodrigo
Published: November 2005

State-of-the-art numerical analyses require mesh representation with a data structure that provides topological information. Due to the increasing size of the meshes currently used for simulating complex behaviors with finite elements or boundary elements (e.g., adaptive and/or coupled analyses), several researchers have proposed the use of reduced mesh representations. In a reduced representation, only a few types of the defined topological entities are explicitly represented; all the others are implicit and retrieved “on-the-fly,” as required. Despite being very effective in reducing the memory space needed to represent large models, reduced representations face the challenge of ensuring the consistency of all implicit entities when the mesh undergoes modifications. As implicit entities are usually described by references to explicit ones, modifying the mesh may change the way implicit entities (which are not directly modified) are represented, e.g., the referenced explicit entities may no longer exist. We propose a new and effective strategy to treat implicit entities in reduced representations, which is capable of handling transient nonmanifold configurations. Our strategy allows, from the application point of view, explicit and implicit entities to be interchangeably handled in a uniform and transparent way. As a result, the application can list, access, attach properties to, and hold references to implicit entities, and the underlying data structure ensures that all such information remains valid even if the mesh is modified. The validity of the proposed approach is demonstrated by running a set of computational experiments on different models subjected to dynamic remeshing operations.
Food allergy in children
Authors: Baral V R , O’B Hourihane J
Published: November 2005

Food allergy is being increasingly recognised with the highest prevalence being in preschool children. Pathogenesis varies so diagnosis rests on careful history and clinical examination, appropriate use of skin prick and serum-specific IgE testing, food challenge, and supervised elimination diets. A double blind placebo controlled food challenge is the gold standard diagnostic test. Avoidance of the allergenic food is the key towards successful management. IgE mediated food allergy may present as a potentially fatal anaphylactic reaction, and management consists of the appropriate use of adrenaline (epinephrine) and supportive measures. Sensitisation remains a key target for intervention. Disease modifying agents are currently under trial for managing difficult allergies. Management requires a multidisciplinary approach and follow up.
Epidemiology, clinical characteristics, and management of adults referred to a teaching hospital first seizure clinic
Authors: Breen D P , Dunn M J G , Davenport R J , Gray A J
Published: November 2005

Background

There are scarce data describing the epidemiology, clinical characteristics, and management of adults who suffer a suspected first seizure.

Aim

To describe the epidemiology, clinical characteristics, and management of adults with a suspected first seizure who are referred to a teaching hospital first seizure clinic over a one year period.

Design

Prospective descriptive study.

Methods

Data were collected on consecutive adults referred to the Royal Infirmary of Edinburgh between 4 February 2003 and 10 February 2004.

Results

232 patients were referred to the first seizure clinic. Median age was 32 years; 53% of patients were male. Lower socioeconomic groups were more likely to present with a suspected first seizure. Nineteen per cent of patients were admitted to hospital after their suspected seizure episode. Appropriate driving advice was reported in 64% of cases. Seventy two per cent of patients were offered a first seizure clinic appointment within six weeks of referral. Nine per cent of patients had a subsequent seizure while awaiting review. Fifty two per cent of patients were confirmed as having a first seizure at the clinic, of which 56% were provoked by alcohol, recreational drugs, or sleep deprivation. Electroencephalography and computed tomography of the brain were the most common investigations ordered at the first seizure clinic (22% and 22% of patients respectively).

Conclusion

Adults who suffer a suspected first seizure, and who make a full neurological recovery, can be safely managed as an outpatient. Around half of these patients will have a specialist diagnosis of first seizure and alcohol will be a common precipitating factor.
Is antibiotic resistance a problem? A practical guide for hospital clinicians
Authors: Barlow G , Nathwani D
Published: November 2005

Antibiotic resistance is an important concern for patients, physicians, healthcare managers, and policymakers. Inappropriate antimicrobial prescribing fuels the evolution of resistance, while poor basic hygiene facilitates the spread of resistant microbes between patients and healthcare staff. The development of infection with a resistant pathogen may lead to poorer health and economic outcomes. The problem for the frontline clinician, however, is how to balance the responsibility of prudent prescribing with the risk of sub-optimally treating a patient who may be infected with a resistant pathogen. This article discusses how hospital physicians can use severity and risk factor assessment, and knowledge of local microbial epidemiology, to guide empiric antibiotic prescribing. Most patients hospitalised with a community acquired bacterial infection in the UK can still be managed with a traditional first line antibiotic(s). In contrast, regimens that account for resistance are often required in patients with hospital acquired infections, particularly if the patient is critically ill.
Pleural effusion
Authors: Medford A , Maskell N
Published: November 2005

Pleural disease remains a commonly encountered clinical problem for both general physicians and chest specialists. This review focuses on the investigation of undiagnosed pleural effusions and the management of malignant and parapneumonic effusions. New developments in this area are also discussed at the end of the review. It aims to be evidence based together with some practical suggestions for practising clinicians.
SIMULATION FOR COMPETITION OF LANGUAGES WITH AN AGING SEXUAL POPULATION
Authors: SCHWÄMMLE V.
Published: November 2005

Recently, individual-based models originally used for biological purposes revealed interesting insights into processes of the competition of languages. Within this new field of population dynamics a model considering sexual populations with aging is presented. The agents are situated on a lattice and each one speaks one of two languages or both. The stability and quantitative structure of an interface between two regions, initially speaking different languages, is studied. We find that individuals speaking both languages do not prefer any of these regions and have a different age structure than individuals speaking only one language.
A THREE-OPINION SZNAJD MODEL WITH LIMITED PERSUASION AND ITS APPLICATIONS
Authors: HE MINGFENG , LI BEI , XU HAIXUAN , LUO LIDONG
Published: November 2005

We propose a three-opinion Sznajd model with limited persuasion in which two neighbors still can influence others when the two opinions differ by a small amount. The simulation results show that the initial condition plays a crucial role in the final results and the interaction between people's opinion occurs in the common boundaries of the small districts constituted by the people holding the same opinion. We apply the model to describe the interaction on the attitude toward studying between students in a class or school which is similar with the opinion evolution and give a rough explanation about why a class or school mostly consists of ordinary students.
COMPOSITIONAL AND ENVIRONMENTAL DEPENDENCE OF THE STABILITY OF α-HELICES
Authors: CHEN CHANGJUN , FENG JIANHUI , ZHANG LINSEN , XIAO YI
Published: November 2005

The stability of α-helices in proteins depends on both their compositions and environments. To see how these two factors match with each other, we selected three typical α-helices from real proteins each of them has different compositions of hydrophobic and hydrophilic amino acids. We simulated the dynamics of the three helices in vacuum and in water using molecular dynamics. The results show that the stabilities of the three α-helices are different in vacuum and in water, which are consistent with their locations in the proteins. We also found some interesting behaviors of these α-helices.
THE EFFECT OF MIXED VEHICLES ON TRAFFIC FLOW IN TWO LANE CELLULAR AUTOMATA MODEL
Authors: JIA BIN , JIANG RUI , GAO ZI-YOU , ZHAO XIAO-MEI
Published: November 2005

In real traffic, the traffic system is usually composed of different types of vehicles, which have different parameters. How these parameters, especially the lengths of the vehicles, influence the traffic behaviors and transportation capability has seldom been investigated. In this paper, we study the mixed traffic system using the cellular automata traffic flow model. The simulation results show that when the road occupancy rate is large, increasing the fraction of long vehicles can apparently, improve the transportation capability. The influence of slow vehicles fraction on the average velocity of vehicles has been discussed, and it is found that the influences are very different when the difference of vehicle length is considered or not.
HIDING THE EXISTENCE OF A FAMILY SYMMETRY IN THE STANDARD MODEL
Authors: MA ERNEST
Published: November 2005

If a family symmetry exists for the quarks and leptons, the Higgs sector is expected to be enlarged to be able to support the transformation properties of this symmetry. There are, however, three possible generic ways (at tree level) of hiding this symmetry in the context of the Standard Model with just one Higgs doublet. All three mechanisms have their natural realizations in the unification symmetry E6 and one in SO (10). An interesting example based on SO (10)×A4 for the neutrino mass matrix is discussed.
FOLD HELICAL PROTEINS BY ENERGY MINIMIZATION IN DIHEDRAL SPACE AND A DFIRE-BASED STATISTICAL ENERGY FUNCTION
Authors: LI HONGZHI , ZHOU YAOQI
Published: November 2005

Statistical energy functions are discrete (or stepwise) energy functions that lack van der Waals repulsion. As a result, they are often applied directly to a given structure (native or decoy) without further energy minimization being performed to the structure. However, the full benefit (or hidden defect) of an energy function cannot be revealed without energy minimization. This paper tests a recently developed, all-atom statistical energy function by energy minimization with a fixed secondary helical structure in dihedral space. This is accomplished by combining the statistical energy function based on a distance-scaled finite ideal-gas reference (DFIRE) state with a simple repulsive interaction and an improper torsion energy function. The energy function was used to minimize 2000 random initial structures of 41 small and medium-sized helical proteins in a dihedral space with a fixed helical region. Results indicate that near-native structures for most studied proteins can be obtained by minimization alone. The average minimum root-mean-squared distance (rmsd) from the native structure for all 41 proteins is 4.1 Å. The energy function (together with a simple clustering of similar structures) also makes a reasonable selection of near-native structures from minimized structures. The average rmsd value and the average rank for the best structure in the top five is 6.8 Å and 2.4, respectively. The accuracy of the structures sampled and the structure selections can be improved significantly with the removal of flexible terminal regions in rmsd calculations and in minimization and with the increase in the number of minimizations. The minimized structures form an excellent decoy set for testing other energy functions because most structures are well-packed with minimum hard-core overlaps with correct hydrophobic/hydrophilic partitioning. They are available online at .
RANDOMIZED ALGORITHMS FOR MOTIF DETECTION
Authors: WANG LUSHENG , DONG LIANG
Published: November 2005

Motivation: Motif detection for DNA sequences has many important applications in biological studies, e.g. locating binding sites regulatory signals, designing genetic probes etc. In this paper, we propose a randomized algorithm, design an improved EM algorithm and combine them to form a software tool.

Results: (1) We design a randomized algorithm for consensus pattern problem. We can show that with high probability, our randomized algorithm finds a pattern in polynomial time with cost error at most ∊ × l for each string, where l is the length of the motif and ∊ can be any positive number given by the user. (2) We design an improved EM algorithm that outperforms the original EM algorithm. (3) We develop a software tool, MotifDetector, that uses our randomized algorithm to find good seeds and uses the improved EM algorithm to do local search. We compare MotifDetector with Buhler and Tompa's PROJECTION which is considered to be the best known software for motif detection. Simulations show that MotifDetector is slower than PROJECTION when the pattern length is relatively small, and outperforms PROJECTION when the pattern length becomes large.

Availability: It is available for free at , subject to copyright restrictions.
Vibrational Spectra of Ruby and Haematite in the Infrared Region
Authors: Mitsuishi Akiyoshi , Yoshinaga Hiroshi , Fujita Shigeru , Suemoto Yoshiro
Published: November 2005

The reflection and transmission spectra of ruby, pure α–Al2O3 and haematite (α–Fe2O3) were observed in the infrared region from 2 to 200 µ. Six bands were found for each compound in accordance with the conclusion of factor group analysis, which predicts two bands polarized parallel to the c-axis and four bands perpendicular to the c-axis. By examining the reflection spectrum with a polyethylene sheet polarizer, the polarization character of some of the bands beyond 17.5 µ was confirmed; but complete assignment of the six bands was not tried because of the insufficiency of the polarization data under 17.5 µ for ruby, and due to unfavorable orientation of the crystal surface for haematite.
Ammonia Maser on the 3, 2 Line as a Frequency Standard I
Authors: Shimoda Koichi , Kohno Noboru
Published: November 2005

The frequency of a maser on the J=3, K=2 line of N14H3 was compared with the multiplied frequency from a 100 kc standard of one of quartz clocks. The measured fluctuation was much larger than that of the maser itself because of small phase fluctuations in the 100 kc signal.
When the maser was tuned by a magnetic perturbation method, the frequency drift and the error in resetting could be kept within several parts in 1011. The observed frequency shift with the focuser voltage was 7×10-11/kV at a source flux of about 7×1017 molecules per second. The frequency-shift with the increase of source flux by 10 percent was about 1×10-11. The stability and reproducibility are discussed in comparison with the hydrogen maser. It is shown that the ammonia maser will reach an accuracy of 10-13, when an automatically balanced double beam is used.
Oscillation Characteristics of a Pulsed Ruby Maser
Authors: Saito Fujio
Published: November 2005

Pulsed oscillation of a three-level ruby maser of which pumping microwave was modulated by pulse was investigated. The time lag t

d
of the oscillation pulse behind the pumping pulse was determined experimentally as a function of the peak level P of the pumping power, and the period T and the width τ of the pumping pulse. A semi-empirical formula
t

d
=t
0(\frac{P_{c}}{P})
k
exp
[b(\frac{T}{\tau})1-δ\frac{P_{c}}{P}]

was obtained. The minimum pulse width τ
m
required for the oscillation to occur was determined as a function of P and T, which was approximately expressed by

τ
m
=c\frac{T^{m}}{P^{n}}.

The above results were qualitatively interpreted in terms of excess population Δ
n,
On the Resonance Acceleration of a Charged Particle in a Modulated Magnetic Field
Authors: Ogawa Iwao
Published: November 2005

Resonance acceleration of a charged particle in a high-frequency modulated uniform magnetic field is investigated analytically. An approximate expression for the motion of the particle under acceleration is obtained by transforming the equation of motion into a Mathieu-Hill type differential equation and by performing a perturbation calculation for a parametric resonance of an arbitrary order. In the case when the acceleration is limited by collision of the particle with the wall of the vessel as well as with a gas molecule, the maximum attainable velocity of the particle is realized when the order of the resonance takes a certain optimum value. The result is fairly consistent with the experiments on electron cyclotron resonance in a radiofrequency ion source.
Anneal Behavior of Aluminum-Implanted Germanium
Authors: Itoh Tadatsugu , Ohdomari Iwao
Published: November 2005

p-Type single crystal germanium is implanted with 1.5×1015 aluminum ions/cm2 at room temperature at 10 keV. Carrier distributions are determined by means of anodic stripping of thin layer combined with Hall effect and sheet resistivity measurements. Anneal behavior of crystalline states is investigated by the observation of implanted surface using reflection electron-diffraction technique after succesive stripping of surface layer. It is found that some of the incident ions penetrate to about 1400 Å during room temperature implantation beyond the range predicted by LSS theory. The minority of deeply penetrated aluminum occupies the substitutional sites and becomes acceptors, while the majority remains electrically inactive. The lattice reordering takes place at 300–400°C but does not remarkably contribute to the increase in carrier concentration. Carrier concentrations increase remarkably after the anneals at 500–600°C by the transition of aluminum atoms to the substitutional sites from the as-implanted inactive sites. Radiation enhanced diffusion of aluminum as observed in silicon is not observed in germanium.
Development of a New Aqueous Solution Highly Sensitive to Flow Birefringence
Authors: Nakatani Noboru , Yamada Tomoharu , Soezima Yosio
Published: November 2005

An aqueous solution, highly sensitive to flow birefringence and showing Newtonian viscosity is developed from the standpoint of material design to make the flow measurement easier using the flow birefringence method. The highly sensitive solution to flow birefringence is obtained by dissolving Congo Red (CR), which has a large optical anisotropy, into the aqueous solution of polyvinyl alcohol (PVA) of the average degree of polymerization 500 and of the average degree of saponification 98.8%, which can be easily oriented under the action of shear rate. The birefringence and viscosity of PVA–CR aqueous solutions are measured for a range of shear rate from 0 to 2000 s-1. The dispersion of flow birefringence with various wavelengths is also determined. The sensitivity of flow birefringence for shear rate is higher by one or two orders of magnitude than that in aqueous solutions employed by previous investigators. The relation between viscosity and shear rate in the solution is Newtonian.
Double Diffraction in the Fresnel Region
Authors: Kodate Kashiko , Kamiya Takeshi , Kamiyama Masahide
Published: November 2005

Double diffraction pattern of two identical gratings placed in the Fresnel region is sensitive to the relative displacement of the gratings, and this phenomenon can be used as a method of displacement measurement. Experimental studies and computer analyses on the contrast revealed that a very high contrast (over 90% modulation depth) can be obtained for the zeroth order beam when the separation of the gratings satisfy the Fourier image conditions. The contrast is also affected by the finite radius of coherent component of the incident laser beam, which was shown by the simultaneous measurement of the spatial coherence factor of the source.
Optimum Smoothing of Infrared Spectroscopic Data with Numerical Filters
Authors: Yamashita Katsuji , Minami Shigeo
Published: November 2005

Numerical smoothing is one of the useful methods to extract the signal components faithfully from noisy spectroscopic data. However, the setting of the filtering parameters has been empirically done to allow the optimum operation because of its complexity. This article discusses the practical methods for finding the relevant parameters of the numerical filter and the data source by using the numerically analyzed characteristics of the least squares convolution filters. The detail procedures are demonstrated in far infrared spectroscopic applications. A result of the quantitative comparison between the numerical filter and the familiar electric RC filter is also given.
Quantitative Microanalysis by Rotating Inclined Target Method in EPMA
Authors: Gennai Norio
Published: November 2005

In determining the angular distributions of characteristic X-rays by using rotating inclined target method in EPMA, the accuracy is discussed in detail. Thef(χ)-curves obtained from these angular distributions of X-rays are applied to quantitative microanalysis in Cu-Au, Ni-Fe and Fe-Cr alloys. The effect of indirect excitation is calculated by using the depth distribution curves of characteristic X-rays obtained in this experiment. The error of the analysis is within 2% and it is shown that the rotating inclined target method may be applied to quantitative microanalysis with about the same accuracy as the case of normal incidence of electron beam without tedious procedure for absorption correction.
Precise Centre Settling Device for Quadrupole Magnets
Authors: Kobayashi Masaaki , Tanaka Jiro , Baba Hitoshi , Yamashita Sukeaki
Published: November 2005

An apparatus for centering drift tube quadrupole magnets and measuring their harmonic field contents is described together with the search coil and its calibration method. Sensitivity within 0.5 µm and reproducibility within ±2 µm can be obtained for the magnetic centre location
Harmonic field components in four types of model magnets are measured for different pole shapes. The pole shape II gives the smallest field nonlinearity.
Edge Emissions of CdS:Li Single Crystals
Authors: Yoshizawa Michio
Published: November 2005

The author produced CdS:Li single crystals by a sublimation recrystalization method and investigated photoluminescence properties of these crystals. In the green and blue edge emission properties of the CdS:Li single crystals, three differences are experimentally observed in comparison with behavior of the undoped crystals, and these behaviors become remarkable with increasing lithium impurity concentration. These experimental results about optically excited edge emission properties and quantitative considerations are presented in this paper.
Temporal Coherence of Q-Switched Ruby Laser
Authors: Umegaki Shinsuke , Tanaka Shun-ichi
Published: November 2005

Theoretical description of the temporal coherence of a multimode Q-switched laser is presented, where the modified mutual coherence function is used and the shape of pulse duration is assumed to be Gaussian. The experiment using a Michelson type two-beam interferometer is performed on a simple case where the Q-switched ruby laser has only a single axial mode. The experimental result that the degree of coherence is gradually degraded with the path difference of two interfering beams agrees fairly well with the theoretical one.
Automatic Record of Small Amount of Electrical Resistance Change of Metals
Authors: Kabemoto Satoru
Published: November 2005

An apparatus has been designed and made up for detecting small electrical resistance changes and recording them automatically. It is free from the thermoelectromotive force because of the use of the low frequency alternative current. This apparatus is used for measuring the changes of the electrical resistance caused by quenching and subsequently annealing metal wires. The error of the indication of the recorder is ±0.5 per cent of the full span of the recorder. As for the slow changes of the resistance of the specimen, the resistance change is detectable to 1.7×10-4 per cent of the specimen resistance used in this experiment. This corresponds to 5×10-12 ohm-cm in resistivity. As for the rapid changes of the resistance of the specimen which are caused during a few seconds, the resistance change is detectable to 2.5×10-3 per cent of the specimen resistance. This corresponds to 7.5×10-11 ohm-cm in resistivity.
Numerical Calculation of Static Magnetization Configuration in Exchange-Coupled Composite Thin Magnetic Films
Authors: Hayashi Nobuo , Goto Eiichi
Published: November 2005

Static magnetization configurations and critical switching curves of exchange-coupled composite thin films are calculated numerically and compared with the results obtained from a previously developed theory which represents the effect of exchange coupling in sufficiently thin composite films in terms of effective multi-axial anisotropies. By dividing the total film thickness into a sufficient number of layers, the magnetic energy of the film is replaced by summation which is a functoin of the orientation of the magnetization in each layer and the extentatinal field. Analysis has been made by means of searching minima of the magnetic energy according to the variational principle.
Thermodynamical Analysis for Vapor Growth of GaxIn1-xAs Crystals
Authors: Nagai Haruo , Shibata Toshitaka , Okamoto Hiroshi
Published: November 2005

The open tube vapor growth process of GaxIn1-xAs crystal in the Ga-In-Cl-H-As system is analyzed by a chemical equilibrium model, and the relation between growth condition and crystal composition is discussed.
The theoretical analysis explained experimental results qualitatively.
Behaviors and Doping Kinetics of Residual Impurities in Epitaxial n-GaAs Layers
Authors: Nakagawa Masashi , Ikoma Hideaki
Published: November 2005

Electrical properties are measured at 300°K and 77°K of epitaxial n-GaAs layers grown by the Ga/AsCl3/H2 method under various growth conditions. To investigate doping behaviors of main residual impurities, donor and acceptor concentrations N

D
and N

A
are calculated as a function of the growth temperature and substrate orientation ((100), (110), (311) A and (111) B). For each orientation, the compensation ratio K(≡N

A
/N

D
) is found to be nearly constant and K is increased as the arsenic partial pressure is decreased, both suggesting that amphoteric impurities (probably Si) are main donors and acceptors. Reaction kinetics are developed based on a simple model of amphoteric impurity doping and compared with experiment. Deviations of K from the constant value and some other possible effects are also discussed.
Microwave Measurement of the Velocity-Field Characteristics in n-Type Gallium Arsenide
Authors: Inoue Masataka , Shirafuji Junji , Inuishi Yoshio
Published: November 2005

In order to clarify the reasons of large conflict in the velocity-field characteristics of GaAs among many experiments reported so far, the effects of nonuniform conductivity and low-field mobility on the velocity-field characteristics are investigated using a microwave-heating technique. Various degrees of nonuniformity are introduced by serial irradiation of electrons on a localized portion of the sample. The results show that the threshold field, peak velocity and negative differential mobility increased with increasing the nonuniformity. The initial value of the negative differential mobility is typically -1660 cm2/vo1t·sec, but it decreases down to -920 cm2/volt·sec after the local electron typically irradiation. Low-field mobility was changed by a uniform irradiation of the sample. As the low-field mobility is decreased, the threshold field increases while the peak velocity and negative differential mobility decreases, as will be predicted from the theory. Some facts supporting the occurrence of the impact ionization of irradiation-induced defects are obtained.
Production of Ion Stream Composed of Two Components in Velocity Distribution
Authors: Honzawa Tadao
Published: November 2005

A new type of ion source, which produces a beam consisting of two energy components, is reported. A diffusion-type plasma source consisting of two arrays of oxide-coated cathode rods and five sheets of metalic mesh grids is employed. The energy distribution of ion stream is observed with an electrostatic energy analyzer whose resolution is 4%. Ion streams of argon, helium, nitrogen and their mixtures are obtained with energies ranging from 50 to 500 eV. The energies of the two components of ion stream are determined by the bias voltages applied to the two pairs of grids, and their relative intensities can be controlled by adjusting the temperature of the fore array of cathode rods and/or the potential of the intermediate grid.
A Total Reflection Type Čerenkov Counter with High Efficiency
Authors: Fujii Tadao , Iwata Seigi , Homma Saburo , Orito Shuji
Published: November 2005

A threshold-type Čerenkov counter which makes use of total reflection in a Lucite radiator, is constructed and tested using pion beams with various velocities. The detection efficiency of about 100% for relativistic particles (β≈1) is obtained. The detection threshold is found to be β≈0.9, whose value is expected from the calculation assuming the index of refraction of Lucite to be 1.49. The counter is successfully used to separate K
± mesons from pions in the momentum range below 700 MeV.
A Device for Measurement of Time-Resolved Profiles of a Line Spectrum Emitted from a Plasma
Authors: Gotô Seiichi , Ishimura Tsutomu
Published: November 2005

A device is constructed to display successive 8 time-resolved profiles of a spectral line from a pulsed plasma on the screen of an usual oscilloscope. It takes 2 µs to display one profile and the time-interval between two successive profiles is chosen to be 10, 15, 20 or 30 µs. The wavelength band-width of each picture on the screen is chosen to be 15, 10 or 6.3Å. The device is composed of a grating monochromater, a set of 3 light guides of 16 channels and an electronic signal processor. The signals corresponding to the 16 wavelength components are sampled and mixed in the processor so that the resultant signal is fed to the vertical input terminal of the oscilloscope. Simultaneously, the horizontal sweep and the brightness modulation waveforms are produced by the processor and applied to the corresponding terminals.
Preparation and Properties of rf Sputtered Films of ZnO as an Ultrasonic Transducer
Authors: Inaba Ritsuo , Ishiguro Takehiko , Mikoshiba Nobuo
Published: November 2005

Technique for preparation and properties of ZnO films by an r
f sputtering method are described. This technique enables to obtain ultrasonic transducers for high frequencies of 300 MHz∼9 GHz, keeping the temperature of substrates between room temperature and 100°C. The films with the resistivity of 4×104 Ωcm are obtained without annealing. It is found that the films are preferentially oriented with the c-axis normal to the substrate at the thickness of 3000Å, but the grain size along the a-axis is estimated to be about 150Å.
EPR Study of Characteristics of Fe3+Ions with Cubic Symmetry in CaF2Crystals
Authors: Zenbutu Sakae , Nakata Ryohei , Sumita Minoru , Higuchi Eiichi
Published: November 2005

CaF2single crystals containing Fe3+ions with cubic symmetry are prepared by co-doping alkali ions as charge compensators, and they are studied at room temperature with an x-band EPR spectrometer. The spectrum observed is described by a spin Hamiltonian, \mathscrH=gβH·S+(a/6)[Sx4+Sy4+Sz4-(1/5)S(S+1)(3S2+3S-1)], whereS=5/2 andSzis along [001] direction. The spin parameters are determined asg=2.005±0.0005 and |a|=(37.3±0.4)×10-4cm-1. The EPR signals are stable at room temperature, but they decay appreciably rapidly at high temperatures above 550°C. The activation energies for the decay are determined as ranging from 1.1 to 2.9 eV, which are dependent upon the kinds of doped alkali ions and also upon the atmospheres around the crystals during the heat treatments.
Determination of the Distribution Coefficients of Li2O into LiNbO3 by Phase Matching Temperatures
Authors: Tsuya Hideki , Fujino Yoshio
Published: November 2005

The authors derive that the variation in the phase matching temperature for second harmonic generation (SHG) along the pull direction of lithium niobate (LiNbO3) crystal is proportional to the fraction solidified, and propose that the distribution coefficients of Li2O into LiNbO3 could be determined by measuring these relationships for crystals grown from the melts of various compositions without analyzing the composition of a crystal. It is found that the distribution coefficients estimated by this technique are in good agreement with the equilibrium distribution coefficients given in the equilibrium phase diagram by Lerner et al.
Dielectric Properties of the Mixtures of α-Fe2O3, TiO2 and Fe2TiO5
Authors: Iwauchi Kōzō , Yamamoto Shigehisa , Bando Yoshichika , Hanai Tetsuya , Koizumi Naokazu , Takada Toshio , Fukushima Syōji
Published: November 2005

Dielectric properties of various types of mixtures of α-Fe2O3, TiO2, and Fe2TiO5 are investigated. Mixtures of α-Fe2O3 and Fe2TiO5, and of TiO2 and Fe2TiO5 powders respectively show the interfacial polarization. For these types of mixtures there are fairly good agreements between observed values of dielectric constant and calculated ones based on the Maxwell two layers model. On the other hand in the cases of the samples obtained by heating the mixture of α-Fe2O3 and TiO2 at 800°C observed values of dielectric constant are much larger than the calculated ones afforded by the Maxwell model. It seemed that dielectric constant in the interfacial polarization depends not only on the fraction of heterogeneous layers in the Maxwell model but also on their structures in the oxides. The Maxwell-Wagner interfacial polarization due to conductive oxides surrounding the surfaces of particles was found.
Dielectric Properties of Fine Particles of Fe3O4 and Some Ferrites
Authors: Iwauchi Kōō
Published: November 2005

A study is made on the dispersions of resistivity and dielectric constant of α-Fe2O3, γ-Fe2O3, Fe3O4, Zn ferrite, Mn ferrite, and MnZn ferrite fine particles over the frequency range of 10 Hz to 1 MHz in the temperature range from 77°K to 300°K. The Maxwell-Wagner interfacial polarization arising from the heterogeneity of oxidation is observed in the fine particles of the oxides, except α-Fe3O3, which are prepared from aqueous solutions of divalent metal salts as well as in the powders of ferrites containing ferrous ions which are prepared by the calcination at high temperatures. The structures of heterogeneity in the fine particles are explained by the model that there are high resistivity shells with poor ferrous ions on the surfaces of the particles.
Transmitted Phonon Drag in Silicon
Authors: Harada Hiroshi , Inuishi Yoshio
Published: November 2005

The transmitted phonon drag in silicon is investigated in the range from 77°K to 200°K. The phonon mean free path varies with temperature as T
-2·7 above 120°K. The signal intensity decreases with decreasing width of the specimen, and becomes large with increasing electrode distance in the signal detecting layer, approaching to the saturation value. At 77°K, distinct effect of the longitudinal magnetic field on the signal intensity is not observed in the range from 0 to 20 kG.
Theoretical Examination of Quasi-Charge-Neutrality in Surface-Density Helical Waves in Solids and Direct Observation of Wave Structure by Schottky-Probe
Authors: Ueno Isao , Tanimoto Mitsumori , Sekiguchi Tadashi
Published: November 2005

The dynamical charge separation, or the dynamical “quasi-charge-neutrality,” which plays an essential role in most solid-plasma waves, is carefully examined theoretically and quantitatively through the explicit use of the Poisson's equation, particularly on the surface-density helical wave in solid. Next, based upon the theoretical results, somewhat more detailed structure of this wave is shown, putting the primary emphasis on the charge-separation and related induced potential. Finally, theoretically predicted wave structure is confirmed experimentally on germanium rod samples in a straight-forward manner by making the most of the useful properties of the Schottky-probe; namely, by the separate detections of time-dependent variations in the carrier density and the induced potential. In experiments, conventionaln+-probes is also utilized for determining the modes, the wave number and the relative amplitude of oscillations.
Flexible Adiabatic Light Guide of Silicon Rubber
Authors: Fukui Shuji , Ohska Tokio , Ueno Koji , Inagaki Yosuke , Sasaki Atsushi , Iwata Seigi , Kusumegi Asao , Mishina Masanori , Miyachi Takashi , Sato Isamu , Ukai Kumataro
Published: November 2005

A certain type of silicon rubber (KE103RTV) is found to be a useful material as an adiabatic light guide for scintillation counters because of its mechanical flexibility. The refractive index of KE103RTV is measured to be 1.410±0.006. The transmission and the resolution of scintillation light pulses through it are comarable with those through acrylic resin light guides. This RTV has the resistivity against high dose of radiation.
Isotopic Ratio of Lithium in Chondrite Measured by an Ion Probe Mass Spectrometer
Authors: Nishimura Hiroshi , Okano Jun
Published: November 2005

Isotopic abundance ratios of lithium, 7Li/6Li, for four stony meteorites and for a terrestrial granite sample, G-1, are measured by an ion probe mass spectrometer. The measured ratios for the meteorites are about 13 percent lower than the ratio for G-1. The results are inconsistent with those obtained by conventional mass spectrometers with surface ionization ion sources at other laboratories. The mass discrimination effects and the systematic errors, which may lower the measured ratios preferentially for the meteorites, are thoroughly investigated in connection with the characteristics of the ion probe mass spectrometer. The origin of the instrumental bias, however, is not found. Although further experimental work with both types of mass spectrometer should be required to reach the final conclusion, the difference is likely existent from the results.
Determination of Trap Levels in Ge3N4 and Barrier Energies at the Ge3N4-Ge Interface by C-V Characteristics
Authors: Yashiro Takehisa
Published: November 2005

A combination of capacitance-voltage (C–V) measurement and photon radiation is used to determine trap levels in germanium nitride and a barrier energy at the germanium nitride-germanium interface. It is found that shallow and deep electron traps are present in germanium nitride and the deep trap levels lie below 3.1 eV from the conduction band edge. By analysis of spectral dependence of photoemission, it is concluded that the barrier energies for photoemission of electrons from the valence band of germanium to the conduction band of germanium nitride are 1.69, 1.65 and 1.53 eV for Al, Au and Ag electrodes on the same wafer, respectively. The reason for the difference between the barrier energies for various metal electrodes is discussed.
The Relation between the Oscillation and the Perpendicular Diffusion in a Field-Free Magneto-Plasma
Authors: Kando Masashi , Takeda Susumu
Published: November 2005

The perpendicular diffusion coefficientD⊥is calculated from the measured radial density gradient in a weakly ionized helium plasma with no applied electric field at a pressure of 2.0 m Torr. The measuredD⊥is inversely proportional to the square of the magnetic fieldB, when an oscillation in the plasma is small. HoweverD⊥increases withB, when the oscillation rapidly increases. The same phase of the oscillation is observed at any point in the tube.
Thermal Formation Factor of Consolidated Porous Medium: Sandstones
Authors: Agrawal M. P. , Bhandari R. C.
Published: November 2005

An attempt has been made to examine the thermal formation factor as calculated from various thermal conductivity equations and to compare it with the electrical formation factor. It has been found that unlike in soils, the electrical and thermal formation factor in sandstones are alike and related to the geometrical characteristic of the medium.
A Study of Methods Suitable for Automatic Measurement of Hk in Permalloy Thin Films
Authors: Kubo A. M. , Dey S. K.
Published: November 2005

This paper discusses the loop tracer methods of measuring the anisotropy field H

K
in permalloy thin films for selecting the most suitable method for automation. It is assumed that the films have a low dispersion. Practical details and results of investigations are given. Some considerations which differ from accepted views are also pointed out.
AC and DC Photoconductivities of Powdered Layers of CdS
Authors: Miyake Tohru
Published: November 2005

The increase of photocurrent by a superposition of DC voltage, which is remarkable only in powdered CdS, is phenomenologically discussed with an equivalent circuit. The photoconductance in powdered CdS is obtained from the AC photo-admittance at frequencies higher than 30 kHz, and is estimated to be 1.3×10-5 mho/cm2 at a light intensity of 100 µW/cm2. The DC photocurrent is influenced largely by interparticle barriers which show the Schottky effect. The AC photoconductance in the presence of a DC voltage is well explained in terms of an equivalent circuit containing barrier-resistance. Similar frequency characteristics to the case of the superposition of a DC voltage are observed on the application of a large AC voltage. It seems that the apparent increase of the photo-admittance in the above case is due to the decrease of the interparticle barrier-resistance.
Epitaxial Growth of Silicon Films on Sapphire and Spinel by Vacuum Evaporation
Authors: Yasuda Yukio
Published: November 2005

Single-crystal silicon films are formed on (1̄01, 2) and (112̄, 0) sapphire and also on (111), (001) and (113) spinel surfaces by evaporation in a vacuum of 2×10-6 Torr. The growth process of these single-crystal films is studied by reflection electron diffraction. The initial deposits on sapphire contain a few orientations, and further deposition leads to the eventual predominance of one orientation. The initial deposits on spinel consist of only one orientation parallel to the substrate orientation, and no orientation change occurs during film growth. A feature in the growth of silicon on these substrates is found to be the growth of the (110) fibrous structure at lower substrate temperatures.
Liquid Hydrogen Target Utilizing a Small Mechanical Refrigerator
Authors: Doi Yoshikuni , Fujii Tadao , Kitami Toyokichi , Okuno Hideki , Takamatsu Kunio
Published: November 2005

A liquid hydrogen target system utilizing a small mechanical refrigerator (6 W at 20°K) has been developed for high energy physics experiments at the electron synchrotron of Institute for Nuclear Study. The hydrogen gas is liquefied at the cold head of the refrigerator and is maintained as a liquid either in a reservoir or in a target container. A development of the pneumatic-type cold valve has enabled a rapid transfer of hazardous liquid hydrogen between a condenser and a thin target container. The liquid hydrogen target of 500 ml can be made ready for the experiment within 7 h and maintained automatically in a steady state for about 1,000 h without any manual operation.
Study of Silicon-Silicon Dioxide Structure by Electron Spin Resonance I
Authors: Nishi Yoshio
Published: November 2005

Three kinds of paramagnetic centers named PA, PB and PC have been found in a silicon-silicon dioxide structure at liquid nitrogen temperature. PA (g=∼2.000, ΔH=∼4 Oe), and PB having anisotropic g-value (g=∼2.000∼2.010, ΔH=∼6 Oe) are in the exide, while PC which also has anisotropic g-value (g=∼2.06∼2.07, ΔH=∼9 Oe) is in the silicon near the Si-SiO2 interface. Distribution of PB is successfully determined that it has the maximum concentration within about 400Å from the interface.
PA and PB appear when the silicon is oxidized in dry oxidizing ambient or the Si-SiO2 is cooled from elevated temperatures to room temperature with a cooling speed of about 500°C/sec. PC appears when the Si-SiO2 is heated at elevated temperatures followed by rapid cooling to room temperature or is exposed to the ambient containing an appreciable amount of hydrogen at elevated temperatures such as 1000°C, for 10 min.
PB is ascribed to a trivalent silicon \overset\shortmid\underset\shortmid-Si· which has a nonbonding orbital electron in the Si-O network. The mechanisms for the various behaviors of the centers are also discussed in detail.
Measurements of Velocity Distribution in Potassium Molecular Beams by Time-of-Flight Method
Authors: Kodera Kumasaburo , Kusunoki Isao , Horinouchi Kunihiko , Isa Kimio , Yoshihara Masahiro
Published: November 2005

Velocity distribution in potassium molecular beams is measured by time-of-flight (TOF) method using a surface-ionization detector, which has high sensitivity and signal-to-noise ratio. The residence time of potassium on tungsten filament surface has been confirmed before hand to be far less than TOF. To avoid troublesome computation for the dynamic response function of the electronic system a sampling method is employed, and the sampled tons are accumulated into a coulombmeter.
Experimental intensity vs. time curves are compared with those by calculations. The calculations are carried out on the assumption of the Maxwellian velocity distributions in molecular beams with a gate function determined for the experimental system. As was the case in previous works, considerable deficiency of low velocity molecules is observed but general agreement with the theory is considered to be reasonable.