bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimization of underlying layer and the device structure for group‐III‐nitride‐based UV emitters on sapphire
Authors: Iida K. , Watanabe H. , Takeda K. , Mori F. , Tsuzuki H. , Yamashita Y. , Iwaya M. , Kamiyama S. , Amano H. , Akasaki I. , Maruyama H. , Takagi T. , Bandoh A. 
Published: March 2008

AbstractEpitaxial lateral overgrowth (ELO) was applied for the growth of AlGaN on a sapphire substrate by metalorganic vapor phase epitaxy. Among several processes, the ELO of AlGaN on grooved AlGaN showed the best surface morphology and the lowest dark‐spot density of 1×108 cm–2 as measured using cathodoluminescence. The light output power of a UV LED fabricated on ELO‐Al0.25Ga0.75N on grooved Al0.25Ga0.75N was the strongest among several UV LEDs fabricated by different processes. The effect of the Al composition in the electron‐blocking (EB) layer on the performance of UV LEDs was investigated. The UV LED with a low‐Al‐content EB layer showed high output power under a low‐injection condition, while the output power of a UV LED with a high‐Al‐content EB layer did not saturate even under a high‐injection condition. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
AlN MSM and Schottky photodetectors
Authors: Dahal R. , Li J. , Fan Z. Y. , Nakarmi M. L. , Tahtamouni T. M. Al , Lin J. Y. , Jiang H. X. 
Published: March 2008

AbstractDeep ultraviolet (DUV) AlN Metal‐Semiconductor‐Metal (MSM) and Schottky barrier photodetectors have been demonstrated by exploiting the epitaxial growth of high quality AlN epilayer on sapphire and n‐SiC substrates, respectively. The fabricated photodetectors exhibited peak responsivity at 200 nm with very sharp cut‐off wavelength at 207 nm along with extremely low dark current, very high breakdown voltages, high responsivity and high DUV to UV/visible rejection ratio. AlN Schottky barrier detectors show high zero bias responsivity and very high thermal energy limited detectivity at zero bias. These outstanding features are direct attributes of the fundamental material properties and high quality of AlN epilayers. These results demonstrated that AlN could be an excellent candidate as an active material for next generation DUV opto‐electronic device applications. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
GaN thin films on z‐ and x ‐cut LiNbO3 substrates by MOVPE
Authors: Ougazzaden A. , Moudakir T. , Aggerstam T. , Orsal G. , Salvestrini J. P. , Gautier S. , Sirenko A. A. 
Published: March 2008

AbstractWe report epitaxial growth of GaN layers on z ‐ and x ‐cut LiNbO3 substrates using MOVPE. GaN layers with the thickness of 450 nm were characterized using X‐ray diffraction. For both, z‐ and x‐ cut orientations of LiNbO3 substrates, the GaN layers have c‐axis orientation normal to the substrate plane and the in‐plane lattice orientation of GaN layers coincides with the primary axes of LiNbO3 substrates. Although GaN layers exhibit almost complete strain relaxation, the residual compressive strain determined with respect to a free‐standing GaN is of the order of +0.37% and +0.2% for z ‐ and x ‐cut substrates, respectively. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Processing efficiency of elastic emission machining for low‐thermal‐expansion material
Authors: Kanaoka Masahiko , Liu Changling , Nomura Kazushi , Ando Manabu , Takino Hideo , Fukuda Yasuaki , Mori Yuzo , Mimura Hidekazu , Yamauchi Kazuto 
Published: March 2008

AbstractExtreme ultraviolet (EUV) lithography is currently being developed as a next‐generation lithography system. In this system, light at a wavelength of 13.4 nm is used, allowing the patterning of lines with dimensions of less than 40 nm. To focus the light, high‐precision optical mirrors are required with a surface roughness of 0.1 nm. In addition, mirror substrates must be low‐thermal‐expansion materials because EUV light is easily absorbed in matter, accordingly converted to heat. ULE (Corning Inc.) and Zerodur (SCHOTT AG) are well‐known examples of such materials. To achieve these requirements for EUV lithography, a high‐performance machining method is needed. In previous studies, the machining performance of elastic emission machining (EEM) for the above materials was examined from the viewpoint of roughness improvement. As a result, we considered that EEM has sufficient figuring and smoothing capability for the fabrication of EUV optics. We next evaluate the processing efficiency of EEM. In this study, the processing efficiency of EEM for a low‐thermal‐expansion material was examined from the viewpoint of the removal rate. As a result of this investigation, the conditions under which the efficiency of EEM is increased were clarified. We analyzed and discussed these conditions. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of change in number of conduction electrons on the spin configuration in transition metal oxides
Authors: Minamitani Emi , Roleda Robert , Diño Wilson Agerico , Kishi Tomoya , Nakanishi Hiroshi , Kasai Hideaki 
Published: March 2008

AbstractWe study the correlation between the spin configuration and the average number of conduction electrons, based on the Kondo lattice type Hamiltonian. We found that a change in the average number of conduction electrons causes a change in the spin configuration. This results from the competition among the strong Coulomb repulsion, Hund's coupling, and antiferromagnetic interaction. A change in spin configuration from an antiferromagnetic ordering to a spin spiral state can be initiated by slightly doping holes into the half‐filled state. We also found that the spin spiral state exhibits a correspondingly larger conductance than the antiferromagnetic state. On the basis of these results, we suggest that it is possible to alter the conductance (transport property) of transition metal oxides by inducing a change in the spin configuration through the application of an external voltage. Copyright © 2008 John Wiley & Sons, Ltd.
Observing copper chloride during dioxin formation using dispersive XAFS
Authors: Fujimori Takashi , Takaoka Masaki , Kato Kazuo , Oshita Kazuyuki , Takeda Nobuo 
Published: March 2008

AbstractThe incineration of municipal solid waste generates dioxins. To control dioxins, it is necessary to determine the mechanism of their formation. Because copper chloride (CuCl2) is one of the strongest catalysts of dioxin formation in fly ash, it is important to study the chemical changes of this compound. To determine the chemical changes of copper, Cu‐K x‐ray absorption near edge structure (XANES) spectra were examined during the heating of model fly ash using a time‐resolved dispersive x‐ray absorption fine structure (DXAFS) technique. The change in the absorption edge of the Cu‐K XANES spectrum revealed a change in the valence of copper and the temperature dependence of the reduction and oxidation of CuCl2. From room temperature to 270 °C, CuCl2 was reduced, and from > 270 to 300 °C, copper was reoxidized in the presence of 10% oxygen. At a constant temperature of 210 or 300 °C, copper was dynamically reduced and oxidized. In experiments using different gas streams, HCl gas had no effect on the reaction of copper, while oxygen gas was essential for the reoxidation of copper. Our results suggest that dioxin formation in fly ash occurs via the chlorination of carbon with the reduction of CuCl2 and carbon gasification catalyzed by copper oxides. Copyright © 2008 John Wiley & Sons, Ltd.
Mental health of patients from different cultures in Germany
Authors: Wittig U. , Lindert J. , Merbach M. , Brähler E. 
Published: March 2008

AbstractBackgroundEmpirical studies on migration and mental health of migrants are still rare. In Germany they are often characterised by low sample sizes and are limited to certain diseases and geographical areas (old federal states). The comparability of their results is limited. Nonetheless, the assessment of migrants’ health is necessary for adequate medical and psychosocial care for this target group.AimTo provide data on mental health of migrants from Poland and from Vietnam in Germany. Methods: We have assessed a random sample of migrants from Poland (n=140) and from Vietnam (n=88) using the Giessen Subjective Complaints List – 24 (GSCL-24) and the Hospital Anxiety and Depression Scale (HADS). Additionally we asked migrants about their knowledge of health care institutions in case of psychosocial problems, their demands and the existing barriers to health care utilisation.ResultsMigrants from Poland and Vietnam have a higher general score of complaints of physical ill-health and higher anxiety and depression values than Germans. Psychosocial and medical institutions are visited less.ConclusionFurther analytical studies are needed to clarify health differences between these groups. Migrants are a heterogeneous group and only group-specific investigations will clarify associations between countries of origin, health status and use of health care institutions.
Explanatory models of addictive behaviour among native German, Russian-German, and Turkish youth
Authors: Penka S. , Heimann H. , Heinz A. , Schouler-Ocak M. 
Published: March 2008

AbstractIn Germany, the public system of addiction treatment is used less by migrants with addictive disorders than by their non-migrant counterparts. To date, the literature has focused primarily on language, sociocultural factors, and residence status when discussing access barriers to this part of the health care system. However, little attention has been paid to cultural differences in explanatory models of addictive behaviour. This is surprising when we consider the important role played by popular knowledge in a population's perceptions of and responses to illnesses, including their causes, symptoms, and treatment.In the present study, we examined explanatory models of addictive behaviour and of mental disorders in 124 native German und Russian-German youth and compared these models to those observed in an earlier study of 144 German and Turkish youth. We employed the free listing technique German and to compile the terms that participating subjects used to describe addictive behaviour. Subsequently, we examined how a subset of our study population assigned these terms to the respective disorders by means of the pile sort method.Although the explanatory models used by the German and Russian-German youth in our study were surprisingly similar, those employed by Turkish youth did not make any fundamental distinction between illegal and legal drugs (e.g. alcohol and nicotine). German and Russian-German youth regarded eating disorders as “embarrassing” or “disgraceful”, but Turkish youth did not. Unlike our German and Russian-German subjects, the Turkish youth did not classify eating disorders as being addictive in nature. Moreover, medical concepts crucial to a proper understanding of dependence disorders (e.g. the term “physical dependence”) were characterised by almost half of our Turkish subjects as useless in describing addictions.These findings show that it is impossible to translate medical or everyday concepts of disease and treatment properly into a different language without considering the connotations and implications of each term as it relates to the respective culture. Terms that are central to Western medical models of disease may otherwise be misunderstood, misinterpreted, or simply rejected.
Inference Generation During Discourse and Its Relation to Social Competence: An Online Investigation of Abilities of Children With and Without Language Impairment
Authors: Ford Janet A. , Milosky Linda M. 
Published: March 2008

Purpose
This study examined whether young children with typical language development (TL) and children with language impairment (LI) make emotion inferences online during the process of discourse comprehension, identified variables that predict emotion inferencing, and explored the relationship of these variables to social competence.

Method
Preschool children (16 TL and 16 LI) watched narrated videos designed to activate knowledge about a particular emotional state. Following each story, children named a facial expression that either matched or did not match the anticipated emotion. Several experimental tasks examined linguistic and nonlinguistic abilities. Finally, each child’s teacher completed a measure of social competence.

Results
Children with TL named expressions significantly more slowly in the mismatched condition than in the matched condition, whereas children with LI did not differ in response times between the conditions. Language and vocal response time measures were related to emotion inferencing ability, and this ability predicted social competence scores.

Conclusion
The findings suggest that children with TL are inferring emotions during the comprehension process, whereas children with LI often fail to make these inferences. Making emotion inferences is related to discourse comprehension and to social competence in children. The current findings provide evidence that language and vocal response time measures predicted inferencing ability and suggest that additional factors may influence discourse inferencing and social competence.
Cube Texture in Ultrathin Molybdenum Permalloy Tape
Authors: Koh P. K. 
Published: March 2008

With identical annealing heat treatment, the role of the major annealed texture component seems to depend primarily upon the degree of cold reduction. Cube texture was evident when all three thicknesses of tape, 12 mil, 14 mil, and 18 mil, were annealed at 760°C. On raising the annealing temperature to 927°C, there was no trace of cube texture in tape which was cold reduced 96.9% before annealing. But cube texture still remained as the strongest annealing texture component in tapes similarly treated at 927%C but cold reduced only 93.8% and 87.5% respectively, before annealing. The present results agree to some extent, although not entirely,with previous investigators on the transitional nature of cube texture in materials similar to, but not the same as, the present tape.
The switching coefficient Sw increases with increasing cube pole concentration in the order of increasing thickness of tapes annealed at 760° and 927°C. Therefore, 12-mil tape with the highest value of Sw would have the longest switching time in μsec under a constant applied field. The squareness ratio of the hysteresis loop, Br/Bm, at the applied field of 12 oe decreases with the increasing cube pole concentration in the order of increasing thickness of tapes annealed at 760° and 927°C. No correlation could be found between cube pole concentration in annealed tapes and observed coercive force.
Temperature Dependence of the Magnetic Properties of Nickel-Iron Alloys
Authors: Clark J. J. , Fritz J. F. 
Published: March 2008

The effect of temperature on the magnetic properties of six commercially available nickel-iron alloys is reported for the temperature range −60°C to +250°C. The trade names of the alloys are: Hipernik, Deltamax, Hipernik V, Supermalloy, 4-79 Mo-Permalloy, and Hymu 80.
The temperature dependence of both ac and dc magnetic properties was determined experimentally over the temperature range. Dc properties were measured by the standard ballistic testing method. At each test temperature sufficient data was taken to plot a normal magnetization curve. Remanent induction and coercive force were also determined at each temperature, these properties being measured relative to magnetizing forces in excess of 100 oersteds. Ac properties were measured by means of a modified Hay bridge, the tests being conducted at frequencies of 60, 400, and 1000 cps. At each test temperature, and for each frequency, total core loss was measured at various inductions in the range characteristic of the alloy being tested. The data presented are the average of the results of tests on six samples of each alloy.
Precipitation in a Beta-Brass-Fe Alloy
Authors: Berkowitz A. E. , Flanders P. J. 
Published: March 2008

Single crystal samples of beta-brass containing 0.1% iron were annealed at 300°C and 400°C in order to develop the iron precipitate particles. At intervals during the anneals, magnetic data were obtained and analyzed in terms of the size, shape, orientation, and general magnetic behavior of the precipitate particles.
During the earliest annealing stages, superparamagnetic behavior was observed, and particle diameters were calculated from the Langevin relation. On continued annealing the magnetic properties indicated the presence of mixtures of superparamagnetic and single domain particles, and subsequently mixtures of single domain and multidomain particles.
Torque curves showed that the particles were single crystals, with iron-like magnetocrystalline anisotropy, oriented with the same crystal habit as the matrix. Single domain behavior was first observed when the particle diameters were of the order of 200 A. Elongation of the particles in the 〈111〉 directions and rotational hysteresis were noted when single domain behavior appeared. The magnetocrystalline anisotropy coefficients calculated from the torque data were reasonably close to those of iron. Maximum remanence was reached before maximum coercive force due to the much larger initial susceptibility of the superparamagnetic as compared to the multidomain particles. This was confirmed by the shapes of the hysteresis loops for the various cases.
Effect of Composition and Processing on the Activity of Some Magnetostrictive Materials
Authors: Davis C. M. , Ferebee S. F. 
Published: March 2008

The dynamic magnetostrictive properties of a number of magnetic materials were determined as a function of composition and processing. The materials investigated include nickel, 2V-Permendur, a cobalt-nickel alloy, several Ni-Fe and Al-Fe alloys, and a group of ferrites represented by the formula Ni1−x−yCoxFe2+yO4 with 0.00≤x≤0.04 and 0.00≤y≤0.08. The parameters measured were: electromechanical coupling coefficient k, reversible permeability μr, dynamic magnetostrictive constant λ, Young's modulus E, and stress sensitivity λμr.
The stress sensitivity of both the Al-Fe alloys and the cobalt-substituted nickel ferrous-ferrites is sensitive to cooling rate. Ordered Al-Fe samples containing approximately 12.0% aluminum were more stress sensitive by a factor of six than were disordered samples of the same compositions. Disordering was accomplished by quenching from above the ordering temperature (approximately 600°C). When 6% of the nickel in cobalt-substituted nickel ferrite was replaced by divalent iron, the value of λμr increased by approximately 40% for quenched samples but remained relatively constant for slow-cooled samples.
The largest values of λμr observed in the Ni-Fe alloys (in excess of 106 dynes/cm2) occur in the range of 40% to 52.5% nickel. Various processing techniques were employed on the Ni-Fe alloys in this range: slow cooling, quenching, magnetic annealing, and variation in annealing temperature between 900°C and 1220°C. Such variations in processing failed to produce more than a 10% change in the value of λμr.
Magnetic Properties of Some Ferrite Micropowders
Authors: Berkowitz A. E. , Schuele W. J. 
Published: March 2008

Micropowders of stoichiometric copper, nickel, and cobalt ferrites were prepared by low temperature (&lt;800°C) treatment of the coprecipitated metal oxalates. The magnetic properties of each ferrite were determined as functions of particle or crystallite size in the range from 70 to &gt;2000 A. Particle sizes were determined from x-ray line broadening and from electron micrographs.
The micropowders exhibited superparamagnetic, single domain, or multidomain behavior depending on the particle size. The critical size for single domain behavior, depending on composition, was between 300 and 700 A. In this size range, high coercive force and remanence were observed in spite of appreciable sintering of the particles in some cases. The remanence values and the magnitude and temperature dependence of the coercive force indicated that magnetocrystalline anisotropy determined the properties of the single domain particles. The magnetic properties of the very small particle size samples showed the large temperature dependence characteristic of superparamagnetism.
Quenched and slowly cooled copper ferrite micropowders were prepared with similar particle sizes. The remanence and coercive force of the quenched samples were much lower than those of the slowly cooled samples. This indicated different critical sizes in these two types of copper ferrite. This could be due to the difference in either the moments or the magnetocrystalline anisotropy.
Microwave and Low-Frequency Oscillations due to Resonance Instabilities in Ferrites
Authors: Weiss M. T. 
Published: March 2008

Microwave and low frequency oscillations have been observed in single crystal yttrium iron garnet disks placed in a microwave cavity with an applied dc field normal to the disk. These oscillations occur when the microwave power incident on the cavity exceeds a certain critical value in the milliwatt range. The oscillations occur as sidebands above and below the incident frequency and can also be observed as a modulation of the microwave output of the cavity.
The above phenomenon is associated with the ferromagnetic resonance instability due to the fact that the resonant frequency of a disk depends on Mz and thus on the rf magnetic field used to drive it. The combination of the disk and the resonant cavity with high power, provides the conditions necessary for relaxation oscillations to be set up.
Variation in Orientation Texture of Ultrathin Molybdenum Permalloy Tape
Authors: Koh P. K. , Lewis H. A. , Graff H. F. 
Published: March 2008

It is necessary to select certain heats of molybdenum Permalloy in order to manufacture cores of ultrathin tape which have satisfactory properties for use in computer applications. In an effort to aid this selection process, quantitative pole density stereograms of {111} poles of 18 mil tapes from six production heats in both cold-rolled and annealed conditions were developed in order to reveal possible variations in texture and magnetic properties.
Cold rolling the tape developed (110)[3¯35] and (110)[33¯5] end orientations as major texture components together with a previously unnoticed cube-on-edge or (110)[001] orientation as a minor texture component whose intensity varies according to a combination of many possible processing variables.
Annealing the tape at 927°C developed (120)[001]+(210)[001]; (113)[78¯5]+(113)[785¯]; and previously unnoticed (110)[001] cube-on-edge texture components. The intensity of each individual texture component depends on the combined effect of many processing variables.
Switching coefficient, squareness of hysteresis loop (Br/Bm) and coercive force were used as magnetic parameters for evaluation of the tape cores. It was found that among other possible combinations of texture components a strong (110)[001] annealed texture component seems to associate with the highest squareness ratio and lowest coercive force of the tapes studied in the present investigation. No correlation was found between texture and switching coefficient.