bluuebunny/crossref_metadata_2025 huggingface dataset:
The Well‐Being Questionnaire: Testing the structure in groups with rheumatoid arthritis
Authors: Pincus Tamar , Griffiths Jaynne , Isenberg David , Pearce Shirley
Published: June 2011

Objectives. The Well‐Being Questionnaire, originally developed in groups with diabetes, is recommended by the World Health Organization for widespread use. This study investigates the validity of the WBQ in patients with rheumatoid arthritis (RA) using structural equation modelling.

Design. Two case‐control studies, comprising postal questionnaires are described.

Method. Questionnaires completed by RA patients (377) and matched controls (282) were analysed using structural equation modelling.

Results. The findings suggest that the full version of the WBQ is not suitable for use in RA populations. A shorter version, measuring positive and negative well‐being fits the data better. Comparisons with matched controls and against the Hospital Anxiety and Depression Scale scores suggest that anxiety is measured well, but that the depression factor does not perform well. Positive well‐being appears to be measured well.

Conclusion. Further research is necessary before the WBQ can be utilized in groups with RA.
Attitude, subjective norm and perceived behavioural control as predictors of women's intentions to take hormone replacement therapy
Authors: Quine Lyn , Rubin Rona
Published: June 2011

Objectives. To examine women's attitudes towards the use of hormone replacement therapy (HRT) and to predict intention to take it in a sample of 1200 women using the theory of planned behaviour (Ajzen, 1988) and a measure of similar prior behaviour.

Design. The design was cross‐sectional. A postal survey was carried out.

Methods. Questionnaires were sent to a random sample of 1200 women aged between 38 and 58 generated from the Kent Family Health Services Authority records. Questions based on the theory of planned behaviour were used to predict women's intentions to take HRT. Information was also collected about the women's sources of information on the menopause, their experience of the menopause and the time leading up to it, their general health, and their sociodemographic circumstances.

Results. Analysis was carried out on the responses of the 641 women who were not yet taking and had never taken HRT. Hierarchical multiple regression analysis showed that similar prior behaviour made a small independent contribution to the prediction of behavioural intention when entered after the components of the model. Structural equation modelling was carried out to show the paths between the variables. When age was included, similar prior behaviour was shown to influence behaviour through perceived behavioural control and attitude.

Conclusions. In predicting women's intention to take HRT, the beliefs of significant others, the women's personal beliefs, their degree of confidence in their ability to carry out the behaviour and the experience of similar prior behaviour are important considerations.
Chronic fatigue syndrome: Symptoms, appraisal and ways of coping
Authors: Knussen Christina , Lee Deborah
Published: June 2011

Objectives. The aim of the study was to investigate the contributions of measures of appraisal and ways of coping (relative scoring) to two clusters of symptoms of chronic fatigue syndrome (CFS; fatigue and emotional disturbance), using multiple regression analysis.

Design. A cross‐sectional design was employed within a framework provided by the Lazarus & Folkman model of stress.

Methods. Participants (N = 81) were drawn from CFS support groups. Self‐report questionnaires were used, including measures of symptoms (Ray, Weir, Phillips & Cullen, 1992), ways of coping with CFS (Ray, Weir, Stewart, Miller & Hyde, 1993), and appraisal of the illness (Browne et al., 1988).

Results. When symptoms of emotional disturbance were controlled, those experiencing more symptoms of fatigue were more likely to perceive CFS to be stressful, were less likely to feel that they could do anything about the illness, and were relatively more likely to cope through seeking information. Those experiencing more symptoms of emotional disturbance were less likely to have an optimistic outlook and were less likely to attempt to cope by accommodating to the illness, irrespective of symptoms of fatigue.

Conclusions. The results confirmed the utility of the Lazarus & Folkman model of stress within this domain. The use of relative coping scores clarified the potential importance of accommodating to the illness. Overall, the results underlined the need to further develop measures and methodologies in this area.
Exploring ‘means to an end’: The application of Bagozzi's theory to riskier single‐occasion drinking
Authors: Murgraff Vered , White David , Phillips Keith
Published: June 2011

Objectives. This is a preliminary study of the applicability of Bagozzi's goal‐directed theory (1992) to single‐occasion drinking. The hypothesis tested is that intentions to drink at lower limits are enacted when one appraises high levels of self‐efficacy, instrumental beliefs, and affect regarding the instrumental acts needed for goal achievement.

Design. The study was based on a self‐reported questionnaire measured at two time intervals. At Time 1, measures of past single‐occasion drinking were collected along with self‐reactions and judgments about various strategies for refusing a drink and perceived likelihood of moderating drinking. Two weeks later measures of drinking behaviour were taken.

Methods. The study included 158 undergraduate riskier single‐occasion drinkers. They were supplied with information about the health risks associated with moderate single‐occasion drinking. The outcome measure was riskier single‐occasion drinking at follow‐up.

Results. High levels of self‐efficacy, instrumental beliefs and affect coupled with high intentions to drink at safer limits did not predict single‐occasion drinking frequency at follow‐up. Past drinking was the only significant predictor of riskier single‐occasion drinking at follow‐up. However, following the process of appraising different strategies for refusing a drink participants reported lower levels of drinking at follow‐up.

Conclusions. Bagozzi's (1992) hypothesis was not supported in relation to higher risk single‐occasion drinking. However, the beneficial effects of the focus upon means and their appraisal for behaviour change promote the role of planning for goal achievement. The implications of these findings for behavioural change are discussed.
The theory of reasoned action and theory of planned behaviour as a function of job control
Authors: Bunce D. , Birdi K. S.
Published: June 2011

Objectives. The predictive strength of the theory of reasoned action (TRA; Fishbein & Ajzen, 1975) was compared with that of the theory of planned behaviour (TPB; Ajzen, 1991) in relation to doctors' intentions to request hospital autopsies as a function of job control, the amount of workplace autonomy an individual possesses. Past behaviour was also taken into account.

Design. Two groups of doctors took part: lower grade doctors (N = 70, house officers, senior house officers, and registrars) where job control (or work autonomy) is low, and senior doctors (N = 48, senior registrars and consultants) who possess greater job control.

Method. Both groups were mailed a questionnaire measuring past behaviour, attitudes, subjective norms, perceived behavioural control and intentions relating to requesting hospital autopsies.

Results. Among lower grade doctors, perceived behavioural control strongly predicted intentions, whereas among senior doctors this association was weaker. In addition, we found that past behaviour independently predicted intentions among senior doctors.

Conclusions. In circumstances of high behavioural control the TPB collapses to the TRA, and past behaviour is likely to have an independent influence on intentions in situations of high behavioural control where routine behaviour has developed.
Expectations of an exercise prescription scheme: An exploratory study using repertory grids
Authors: Jones Fiona , Harris Peter , Waller Hilary
Published: June 2011

Objectives. The study aimed to investigate in depth the personal constructs relating to exercise of individuals referred by their medical practitioner for a 10‐week gym‐based exercise programme. It further aimed to study the expectations of change on these constructs and the extent to which these predicted adherence. A subsidiary aim was to evaluate the usefulness of repertory grid methodology in the exercise context.

Design. This was a longitudinal study.

Methods. Participants were interviewed at the start of the 10‐week exercise programme. During the interview they completed repertory grids designed to elicit constructs about exercise‐related change. Participants were followed up at three months to check adherence.

Results. Three illustrative individual case studies are presented in detail followed by some aggregated analyses. These suggest that expectations of change were very diverse and often overoptimistic. Those who completed their course of exercise had more modest expectations of change than those who failed to complete. They also showed less gulf between their current view of themselves and their view of themselves as they would like to be.

Conclusions. The study suggests that having realistic aims and understanding of the outcomes that can be expected from a brief exercise programme is an important predictor of success, but one that may currently be overlooked in the enthusiasm to implement exercise prescription schemes.
Using information for emotion‐focused coping: Cancer patients' use of a cancer helpline
Authors: Broadstock Marita , Borland Ron
Published: June 2011

Objectives. This study investigated the role of information in coping through use of a cancer specific telephone helpline by 101 adults with cancer.

Design. Use of the service was measured by interview schedule between 3 and 11 days after participants called the helpline. Selected items were coded to compute scores of emotion‐focused coping and of problem‐focused coping. This permitted investigation of the relationship between mode of coping and other aspects of helpline use and characteristics of the caller.

Methods. An interview schedule was administered over the telephone.

Results. The findings indicate that information received over the telephone was frequently associated with emotion‐focused coping efforts as well as for problem‐focused efforts. Mailed literature was also associated with significant emotion‐focused coping.

Conclusions. Implications for the conceptualization of information use in coping models and measures are discussed and suggestions made for the development of cancer information services.
Social support and health in adolescence: A factor analytical study
Authors: Pikó Bettina
Published: June 2011

Objectives. This study aimed to investigate whether there are age‐specific characteristics and gender differences in which dimensions of social support are important correlates of health in an adolescent population.

Design. Factor analysis was conducted to investigate the types of social support and t tests to investigate gender differences between the means of support factors and health variables of boys and girls; correlation coefficients were calculated to test the relationships between social support and health‐related variables.

Methods. The Inventory of Socially Supportive Behaviors (ISSB) was designed to assess received social support. The following health‐related variables were applied: psychological well‐being, the frequency of common psychosomatic symptoms, self‐perceived health, acute and chronic illness episodes. Data were collected among secondary school students (N = 1039) in Szeged, southern Hungary.

Results. Factor analysis of the received social support items gave five factors: emotional support, informational support, task‐oriented guidance, rational–material support and practical support. Significant but small correlations were detected between the social support factors and health‐related variables. While emotional and informational support were more supportive factors for health among girls, rational–material support proved to be a more influential factor among boys. Moreover, task‐oriented guidance showed a significant non‐supportive relationship with the frequency of psychosomatic symptoms among boys.

Conclusions. There are characteristics specific to adolescence in the factor structure of the ISSB and the support–health interactions. Future research should focus more on the negative effects of some aspects of social support to identify the special characteristics of the support systems in adolescence.
Subjective well‐being and dieting
Authors: Roncolato Wendy G. , Huon Gail F.
Published: June 2011

Objective. To investigate the dysphoric mood and negative feelings of well‐being among dieters, using Brunstein's (1993) goal‐setting model.

Design. Two time‐extended studies were carried out. The first involved 83 girls (M = 16 years, 9 months) who were assessed twice across five weeks. The second study tested 27 consistent, adolescent female dieters at the beginning and end of a three‐month period. Within‐subject analyses also compared weight loss and academic goal setting.

Methods. Participants completed questionnaire‐based measures of subjective well‐being, goal‐setting commitment, perceived attainability and progress.

Results. In the first study, improvement in well‐being occurred in relation to manageable academic goals but not in relation to weight loss. Participants in the second study experienced an increase in negative affect, particularly if they were highly committed to their weight‐loss goal and perceived it to be difficult to attain.

Conclusions. The findings in relation to academic goals emphasize the importance of helping young girls to identify goals that are personally ‘achievable’. In contrast, the results involving dieting suggest that our efforts should be directed towards enhancing young girls' body esteem and discouraging attempts at weight loss, especially given that most of the girls were within a healthy weight range prior to their weight‐loss attempt.
Synthesis and Characterization of Polyurethanic Proton Exchange Membranes
Authors: Bottino A. , Capannelli G. , Comite A. , Costa C.
Published: June 2011

Novel proton exchange membranes have been prepared by in synthesis functionalization of a polyurethane matrix with a sulfonic group containing chain terminals. The synthesis procedure was based on the use of two polyethylene glycols with nominal molecular weight of 300 and 1 k and 4,4′ dicyclohexylmethane diisocyanate in presence of the sodium salt of isethionic acid as a donor of the sulfonic group. Glycerol was added in order to improve by reticulation the stability of the cast films. The membranes were characterized in terms of swelling, morphology, methanol permeability, proton conductivity, and ion exchange capacity. The best H2/air cell performance was achieved at 80 °C with a maximum power density of 16.9 mW/cm2 at a voltage of about 0.35 V. Polyurethane based ionomeric membranes have proved to be interesting candidates for proton exchange membrane fuel cells (PEMFC) applications.
Fluctuation analysis of work function of organic semiconductors
Authors: West Ryan M. , Watts Colby R. , Josowicz Mira , Janata Jiří
Published: June 2011

We demonstrate, for the first time, work function fluctuations of a polyaniline film when used as the gate conductor of an insulated-gate field-effect transistor. The work function fluctuations induce drain current fluctuations, which are in excess of the channel noise of the transistor and the Nyquist noise of the polyaniline film. Using the fluctuation-dissipation theorem, it is determined that the fluctuations have a Lorentzian-like spectrum and are thermally activated with an activated energy of ca. 300 meV. The activation energy, as well as the corner frequency and magnitude of the fluctuations, depend on the applied electric field at the polyaniline–insulator interface. These results, along with coherence measurements, suggest that the fluctuations originate near the interface in the space-charge region of polyaniline. This technique provides kinetic and thermodynamic information about the gate conductor, at equilibrium, which cannot be extracted using other techniques that measure work function. Furthermore, by this technique it is possible to distinguish the fluctuations of the work function from the Nyquist noise. This approach should be generally applicable to any semiconducting material used as the gate conductor of a field-effect transistor.
AN OFF-LINE TEXT-INDEPENDENT PERSIAN WRITER IDENTIFICATION METHOD
Authors: HELLI BEHZAD , MOGHADDAM MOHSEN EBRAHIMI
Published: June 2011

The behavioral-biometrics methods of writer identification and verification have been considered as a research topic for many years. However, many writer identification and verification methods have been designed based on English handwriting properties, but because of many differences between English and Persian handwriting and the challenges facing Persian handwriting analysis, designing such methods has many interests in Persian yet. In this paper, we have presented a fully text-independent and texture based method for identifying writers of Persian handwritten documents. As a result of special properties of Persian handwriting, a modified version of Gabor filter that is called Extended Gabor (XGabor) filter has been used to extract the features. An MLP (Multi Layer Perceptron (Node)) neural network and a K-NN classifier have been employed to classify the extracted features. In the evaluation phase, an exhaustive database of Persian handwritten documents was prepared and the method applied on. The experimental results showed that the accuracy of proposed method is about 97% and it is competitive with others. We believe that the proposed method may be extended to identify writers in other languages by adjusting some parameters.
AN IMMUNE-INSPIRED EVOLUTION STRATEGY FOR CONSTRAINED OPTIMIZATION PROBLEMS
Authors: CHEN JIANYONG , LIN QIUZHEN , SHEN LINLIN
Published: June 2011

Based on clonal selection principle, this paper proposes an immune-inspired evolution strategy (IIES) for constrained optimization problems with two improvements. Firstly, in order to enhance global search capability, more clones are produced by individuals that have far-off nearest neighbors in the less-crowed regions. On the other hand, immune update mechanism is proposed to replace the worst individuals in clone population with the best individuals stored in immune memory in every generation. Therefore, search direction can always focus on the fittest individuals. These proposals are able to avoid being trapped in local optimal regions and remarkably enhance global search capability. In order to examine the optimization performance of IIES, 13 well-known benchmark test functions are used. When comparing with various state-of-the-arts and recently proposed competent algorithms, simulation results show that IIES performs better or comparably in most cases.
ABOUT OPTIMAL CLONING AND ENTANGLEMENT
Authors: DURT THOMAS , DE PUTTE JOHAN VAN
Published: June 2011

The main non-classical feature of quantum key distribution (QKD) is that it is characterized by a trade-off relation that limits the information possibly gained by a spy and the quality of the transmission line between the authorized users. In particular, perfect cloning is impossible, due to this trade-off, while optimal imperfect cloning saturates the trade-off relation. We investigate by numerical methods the deep nature of this trade-off relation, in the case of optimal cloning, and find that it reveals a subtle interplay between fidelity and entanglement.
QUANTUM CHANNELS OF THE QUTRIT STATE TELEPORTATION
Authors: TIAN XIU-LAO , SHI GUO-FANG , ZHAO Yong
Published: June 2011

Qudit quantum system can carry more information than that of qubit, the teleportation of qudit state has significance in quantum information task. We propose a method to teleport a general qutrit state (three-level state) and discuss the necessary and sufficient condition for realizing a successful and perfect teleportation, which is determined by the measurement matrix Tα and the quantum channel parameter matrix (CPM) X. By using this method, we study the channels of two-qutrit state and three-qutrit state teleportation.
DYNAMICS OF INFORMATION IN THE PRESENCE OF DEFORMATION
Authors: METWALLY NASSER
Published: June 2011

The entanglement of atomic system consisting of two atoms interacting with a deformed cavity mode is quantified by the means of Bloch vectors and the cross dyadic of the traveling state inside the cavity. For large value of the deformation, the amplitude of Bloch vectors decrease very fast and consequently, the traveling state turns into mixed state quickly. The generated entangled state is used as quantum channel to implement quantum teleportation protocol. It is shown that both the deformed parameter and the number of photons inside the cavity play a central role in controlling the fidelity of the transmitted information.
MEMORIES OF BRITTON CHANCE AND THE BRITTON CHANCE AWARD
Authors: CICCO GIUSEPPE
Published: June 2011

Britton Chance has been a person of superlative quality, a close friend, a great teacher and researcher, and a well-known and revered scientist in biochemistry.
WORKING WITH AND LEARNING FROM BRIT
Authors: LI LIN Z.
Published: June 2011

I had been closely working with Dr. Britton Chance from 2005–2010 on imaging mitochondrial redox state in cancer and stem cells. I had also learned much from him in daily work and personal life. Here I would like to share some of my memories and experiences including (1) Great science is not necessarily done with top-grade expensive instruments; (2) Brit was genuinely interested in and dedicated to science; (3) Brit's attention to detail and timely action; (4) Brit's open-mindedness; and (5) Brit being modest, appreciative, and caring for others.
Growth of Sc-Doped TiO2 Thin Film by RF Magnetron Sputtering
Authors: Tomiyama Kazuya , Kobayashi Yusuke , Tsuda Mitsuru , Higuchi Tohru
Published: June 2011

Sc-doped TiO2 (Ti1-x
Sc
x
O2-δ) thin film on Al2O3 substrate were prepared by RF magnetron sputtering using ceramics targets. The Ti1-x
Sc
x
O2-δ thin films deposited at room temperature were crystallized by postannealing at 800 °C for 1 h in O2 atmosphere. The thin films exhibited the single phase of rutile at x=0, the single phase of anatase at x=0.01 and mixed phases of rutile and anatase at x=0.03, and 0.05. The postannealed thin films were very smooth surface. In the absorption spectra, the fundamental absorption edge of Ti0.99Sc0.01O2-δ thin film with anatase phase shifts to lower wavelength side than those of x=0, 0.03, and 0.05. The small Sc doping for TiO2 thin film contributes to the changes of band gap, lattice constant and crystal structure. The existence of acceptor-doped TiO2 may realize practical application of a wide gap semiconductor diode in blue-light region or fuel cell, which used oxide material.
Transport Properties of 50Li2O–50B2O3 Glass
Authors: Kim Hyun Chul , Song In Girl
Published: June 2011

The transport properties of 50Li2O–50B2O3 glass have been investigated. Time resolved current spectra (TRCS) showed repetitions of typical charge and discharge processes. The model circuit and equation for TRCS and the equation of the relationship between turning times of polarization (TTP) and configuration energy (CE) have been suggested. The results obtained using the equations were consistent with experimental results, and configuration energy and dipole length were obtained. The kink phenomenon showed that three or more types of charges participated in the polarization. Complex impedance spectra (CIS) consisted of the semi-arc and the spur due to the electrode-specimen polarization. The peak frequencies of complex modulus spectra (CMS) showing the non-Debye-type relaxations shifted to the high-frequency region as temperature increased, and the activation energy of relaxation was obtained. The migration concept (MC) was satisfied at the dispersion and peak regions, but slightly swerved in the tail part. The fractal dimensionality showed a three-dimensional character.
Annealing Effects on Conductivity and Microwave Dielectric Loss of MgTiO3Ceramics
Authors: Zhu Hong , Kuang Xiao-Jun , Wang Chun-Hai , Xia Hai-Ting , Li Lei , Hu Peng , Jing Xi-Ping , Tang Zong-Xi , Zhao Fei , Yue Zhen-Xin
Published: June 2011

MgTiO3ceramics were annealed in various atmospheres of air, O2and N2at a low temperature of 800 °C and the influences of annealing on the conductivity and microwave dielectric loss were investigated. The conductivity variation with the annealing atmosphere is consistent with the defect equilibrium 2OO×↔2VO••+ O2↑+ 2e', indicating n-type conductance for MgTiO3. Annealing in air/O2is favorable for eliminating oxygen vacancies and electron defects and thus decreases the conductivity. The N2-annealing increases the contents of oxygen vacancies and electron defects as well as the conductivity. Annealing in air/O2/N2reduced the microwave dielectric loss irrespective of the contrary effects of air/O2-annealing and N2-annealing on the defects and conductivity, suggesting the frozen defects associated with the oxygen loss during the high-temperature sintering and the low-temperature N2-annealing have negligible effects on microwave dielectric loss. Other factors, such as the release of thermally induced strain, may be responsible for the reduction of microwave dielectric loss due to the low-temperature annealing in air/O2/N2.
Properties of a Rubidium Isotope Ion Beam Extracted from a Laser Ion Source
Authors: Tamura Koji
Published: June 2011

An atomic beam of rubidium was isotope selectively photoionized by irradiating the fundamental output of a Ti:sapphire laser and the third harmonics of a Nd:YAG laser. The resultant rubidium ions were extracted and collimated with electrodes as a laser ion source. Ion images of 85Rb and 87Rb were observed on the phosphor screen of a microchannel plate (MCP). It was possible to optimize the observed beam spot size by varying the potential applied to the electrodes. The ion energy corresponded to the potential of the laser-irradiated position between the electrodes. The ion source has potential use as an isotope-selective tool for material processing.
Results of Beam Extraction Performance for the KSTAR Neutral Beam Injector
Authors: Chang Doo-Hee , Jeong Seung Ho , Kim Tae-Seong , Lee Kwang Won , In Sang Ryul , Jin Jung-Tae , Chang Dae-Sik , Oh Byung-Hoon , Bae Young-Soon , Kim Jong-Su , Cho Wook , Park Hyun-Taek , Park Young-Min , Yang Hyung-Lyeol , Watanabe Kazuhiro , Dairaku Masayuki , Tobari Hiroyuki , Kashiwagi Mieko , Hanada Masaya , Inoue Takashi
Published: June 2011

The first neutral beam injector (NBI-1) has been developed for the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. The first long pulse ion source (LPIS-1) has been installed on the NBI-1 for an auxiliary heating and current drive of KSTAR plasmas. The performance of ion and neutral beam extractions in the LPIS-1 was investigated initially on the KSTAR NBI-1 system, prior to the neutral beam injection into the main plasmas. The ion source consists of a magnetic bucket plasma generator with multipole cusp fields and a set of prototype tetrode accelerators with circular apertures. The inner volume of the plasma generator and accelerator column in the LPIS-1 is approximately 123 L. Design requirements for the ion source were a 120 kV/65 A deuterium beam and a 300 s pulse length. The extraction of ion beams was initiated by the formation of arc plasmas in the LPIS-1, called the arc-beam extraction method. A stable ion beam extraction of the LPIS-1 was achieved up to 85 kV/32 A for a 5 s pulse length and 80 kV/25 A for a 14 s pulse length. An optimum beam perveance of 1.15 µperv was observed at an acceleration voltage of 60 kV. Neutralization efficiency was measured by a water-flow calorimetry (WFC) method using a calorimeter and the operation of a bending magnet. The full-energy species of ion beams were detected by using the diagnostic method of optical multichannel analyzer (OMA). An arc efficiency of the LPIS was 0.6–1.1 A/kW depending on the operating conditions of arc discharge. A neutral beam power of ∼1.0 MW must be sufficiently injected into the KSTAR plasmas from the LPIS-1 at a beam energy of 80 keV.
Novel Thermographic Method for Characterizing Transformation Temperatures of Thin-Film Shape Memory Alloys Aimed at Combinatorial Approach
Authors: Aono Yuko , Sakurai Junpei , Shimokohbe Akira , Hata Seiichi
Published: June 2011

A novel characterization method for the two-way martensitic transformation temperatures of thin-film shape memory alloys (SMAs) is proposed. The method uses thermography to detect the transformation as a change in emissivity. The proposed method was demonstrated for a Ti–Pd–Ni thin-film SMA along with electrical resistivity monitoring. Definite emissivity changes were observed during both heating and cooling. Furthermore, the changes in emissivity corresponded to changes in the electrical resistivity. To confirm the validity of the proposed method, the results were compared with results obtained using conventional differential scanning calorimetry (DSC). The reverse-martensitic transformation temperature was found to agree with the results of the proposed method. However, the martensitic transformation temperature did not agree well. The reason for this disagreement is the differences in the definition of the transformation temperature and stress conditions used. We expect that the proposed method will enable high-throughput characterization of SMAs by a combinatorial approach in the future.
In situ Observation of Supercooled Liquid–Crystal Phase Transition in Glassy Ferroelectric LaBGeO5
Authors: Takahashi Yoshihiro , Yasuoka Tomomichi , Osada Minoru , Ihara Rie , Fujiwara Takumi
Published: June 2011

Inelastic light scattering was observed in situ from glassy ferroelectric LaBGeO5, which crystallizes the stillwellite-type stoichiometric phase, in the glass–supercooled liquid (SCL) and subsequent SCL–crystal phase transition regimes. The dynamics of the planar BO3 unit in the crystal growth period of the crystallization process was clarified through in situ observation.
Low-Frequency Contact Noise of GaN Nanowire Device Detected by Cross-Spectrum Technique
Authors: Li Liang-Chen , Huang Kuo-Hsun , Wei Jia-An , Suen Yuen-Wuu , Liu Ting-Wei , Chen Chia-Chun , Chen Li-Chyong , Chen Kuei-Hsien
Published: June 2011

We report the properties of low-frequency contact noise of multielectrode GaN nanowire (NW) devices. A two-port cross-spectrum technique is used to discriminate the noise of the ohmic contact from that of the NW section. The diameter of the GaN NW is around 100 nm. The Ti/Al electrodes of the NWs are defined by e-beam lithography. The typical resistance of a NW section with a length of 800 nm is about 5.5 kΩ and the two-wire resistance is below 100 kΩ. The results show that the low-frequency excess noise of the GaN NW is much smaller than that of the current-flowing contact, indicating that the contact noise dominates the noise behavior in our GaN NW devices. A careful study of the noise amplitude (A) of the 1/f noise of different types of NW and carbon nanotube devices, both in our work and in the literature, yields an empirical formula for estimating A from the two-wire resistance of the device.
The Impact of Y Addition into TiO2 on Electronic States and Resistive Switching Characteristics
Authors: Ohta Akio , Goto Yuta , Kazalman Mohd Fairuz , Wei Guobin , Murakami Hideki , Higashi Seiichiro , Miyazaki Seiichi
Published: June 2011

We have studied electronic structures and resistive switching characteristics of Y-doped TiO2 films as a function of Y content to improve the performance on resistive switching of TiO2-based ReRAM. TiY
x
O
y
films with different Y contents were deposited on a Pt layer by metal organic chemical vapor deposition (MOCVD) using dipivaloymethanato (DPM) precursors and followed by O2 anneal to densify the films. A fairly good compositional uniformity in each TiY
x
O
y
film was confirmed by X-ray photoelectron spectroscopy (XPS) analysis. The energy bandgap (E
g) of the TiY
x
O
y
films, which was determined by analyzing the absorption coefficient, was gradually increased with the Y content. Since a decrease in valence band offset between TiY
x
O
y
and Pt was almost the same as that in E
g, the conduction band offset was almost constant at ∼1.3 eV. The current–voltage (I–V) characteristics of TiY
x
O
y
films, which were measured by sweeping positive bias to a Au top electrode after forming process, show non-polar type resistive switching and its beneficial change with Y incorporation into the TiO2 matrix. The Y addition is quite effective to improve endurance in resistive switching and to reduce the variations of operation voltages (V
SET and V
RESET).
Multilayered Thin Metal Film Deposition by Sequential Operation of Nanosilicon Electron Emitter in Metal–Salt Solutions
Authors: Ohta Toshiyuki , Gelloz Bernard , Koshida Nobuyoshi
Published: June 2011

The use of a nanocrystalline silicon (nc-Si) ballistic electron emitter in metal–salt solutions induces the deposition of thin metal films. The nc-Si emitter is composed of a thin Au/Ti film, an anodized polycrystalline Si layer, and an n+-Si substrate. When the emitter is driven in NiCl2, CoSO4, and ZnSO4 solutions without using any counter electrodes, thin Ni, Co, and Zn films are deposited on the emission area, respectively, as well as a thin Cu film in CuSO4 solution. According to cyclic voltammogram measurements under a standard three-electrode configuration, the hot electron injection effect into the solution is clearly observed in all cases at potentials within the electrochemical window, in which no electrolytic reactions occur. Energetic electrons injected into the solutions cause the direct reduction of metal ions. As a possible application, the multilayered deposition of different metals is demonstrated by sequential operation in NiCl2 and CuSO4 solutions.
Nanosize Patterning with Nanoimprint Lithography Using Poly(vinyl alcohol) Transfer Layer
Authors: Park In-Sung , Nichols William T. , Ahn Jinho
Published: June 2011

Coupling the imprint mold structure having a self-assembled monolayer (SAM) and a buffer oxide layer (BOL) with a poly(vinyl alcohol) (PVA) resin is investigated for thermal nanoimprint lithography on flexible substrates. The mold structure is SAM/BOL/Cr. Among the buffer oxides tested (SiO2, Al2O3, HfO2), SiO2 results in the most hydrophobic character at the SAM surface of the mold. Water-soluble PVA resin is shown to be an excellent pattern transfer layer due to its clean release from the hydrophobic mold and strong barrier to SF6 etching during subsequent substrate patterning. The combination of SAM/SiO2/Cr mold structure with PVA resin is demonstrated to produce high quality, defect-free nanopatterns on both rigid silicon and flexible poly(ethylene terephthalate) and polyimide substrates.
Electron Transport Properties of Pt Nanoarch Fabricated by Electron-Beam-Induced Deposition
Authors: Wakaya Fujio , Takamoto Kunio , Teraoka Tsuyoshi , Murakami Katsuhisa , Abo Satoshi , Takai Mikio
Published: June 2011

Pt nanoarches were fabricated by electron-beam-induced deposition. The resistances of the nanoarches with oxygen-radical process, annealing in a furnace, and joule heating by current flow through the nanoarch were measured at room temperature and low temperatures to discuss the coherent electron field emission from the material. It is found that the resistance of the nanoarch increases by the oxygen-radical process and decreases by the current passing through the nanoarch due to the temperature rise. The decreased resistance should contribute to the coherent electron emission.
Determination of Exciton Binding Energy of GaInNAs Quantum Well Structures by Piezoelectric Photothermal Spectroscopy Compared with Photoreflectance Measurements
Authors: Kashima Koshiro , Fukuyama Atsuhiko , Sakai Kentaro , Yokoyama Hirosumi , Kondow Masahiko , Ikari Tetsuo
Published: June 2011

The exciton binding energies (E
xb) of a dilute nitride Ga1-y
In
y
N0.012As0.988 layer (y = 0.0 to 4.5%) with the thickness of 100 nm were determined by both piezoelectric photothermal (PPT) and photoreflectance (PR) spectroscopies. Curve-fitting analyses were carried out using a three-dimensional direct allowed-transition model with the Voigt function as a convolution integral for PPT and with Aspnes' formula for PR. The observed estimation error for PR was about two times larger than that of PPT. Therefore, we conclude that PPT is a novel methodology for determining E
xb when it is small and two expected critical energies exist in the narrow energy region.
Electromechanical Displacement Detection With an On-Chip High Electron Mobility Transistor Amplifier
Authors: Oda Yasuhiko , Onomitsu Koji , Kometani Reo , Warisawa Shin-ichi , Ishihara Sunao , Yamaguchi Hiroshi
Published: June 2011

We developed a highly sensitive displacement detection scheme for a GaAs-based electromechanical resonator using an integrated high electron mobility transistor (HEMT). Piezoelectric voltage generated by the vibration of the resonator is applied to the gate of the HEMT, resulting in the on-chip amplification of the signal voltage. This detection scheme achieves a displacement sensitivity of ∼9 pm·Hz-1/2, which is one of the highest among on-chip purely electrical displacement detection schemes at room temperature.
Highly Uniform Fabrication of Diffraction Gratings for Distributed Feedback Laser Diodes by Nanoimprint Lithography
Authors: Tsuji Yukihiro , Yanagisawa Masaki , Yoshinaga Hiroyuki , Inoue Naoko , Nomaguchi Toshio
Published: June 2011

We have used a nanoimprint technique to fabricate diffraction gratings of distributed feedback laser diodes (DFB LDs) used in optical communication. We have aimed to establish the fabrication process featuring the high reproducibility of the period and linewidth of grating corrugations, which leads to an increase in the production yield of DFB LDs. The combination of the reverse tone nanoimprint and optimized etching techniques has contributed to the improvement of the reproducibility. The variation in grating period has been less than 0.2 nm and the variation in linewidth has been less than 10 nm over the six wafers. The results of this study indicate that our fabrication process for the diffraction gratings utilizing the nanoimprint technique has a high potential for the fabrication of DFB LDs.
Study on Change in UV Nanoimprint Pattern by Altering Shrinkage of UV Curable Resin
Authors: Hiroshima Hiroshi , Suzuki Kenta
Published: June 2011

Pattern width shrinkage in UV nanoimprint is a basic characteristic which must be fully understood when working with this technology. However, the characteristics of fine structures in the realm of sub-100 nm features remain to be understood. It has been difficult to determine the pattern shrinkage by a simple comparison between mold groove width and UV nanoimprint pattern width. Hence, instead of such a comparison, we compared UV nanoimprint patterns made of the same material but with different shrinkage ratios by altering the ambient in the imprinting space using air and pentafluoropropane (PFP). UV nanoimprint in air and PFP was carried out using the UV curable resin PAK-01 and the widths of the fabricated patterns were precisely determined from scanning electron microscopy (SEM) images using an edge detection program. The differences between the widths of patterns fabricated in air and PFP were found to be 6.0, 8.4, and 11.1 nm for nominal pattern widths of 45, 65, and 90 nm, respectively. The width shrinkage ratio for UV nanoimprint in PFP was estimated to be 14% regardless of pattern width and the figure reasonably agreed with the 11% shrinkage predicted by simulation.
Optically Transparent and Refractive Index-Tunable ZrO2/Photopolymer Composites Designed for Ultraviolet Nanoimprinting
Authors: Kudo Shimpei , Nagase Koichi , Kubo Shoichi , Sugihara Okihiro , Nakagawa Masaru
Published: June 2011

Epoxy-based, acrylate-based, and urethane-based ultraviolet (UV)-curable resins containing acrylate-modified zirconia nanoparticles (ZrO2-NPs) were prepared. UV-cured composite films fabricated using an acrylate-based resin and an epoxy-based resin exhibited a high transmittance >90% at visible and near-infrared wavelengths until the weight fraction of ZrO2-NPs having an average zirconia core diameter of 4.0 nm reached 0.66. Their refractive indices at 633 nm were widely controllable between 1.515 and 1.659 for the acrylate-based composite films and between 1.589 and 1.679 for the epoxy-based composite films. Thin films of the UV-curable composite resins could be transformed by UV nanoimprinting in pentafluoropropane using a fluorinated silica mold. Among the composite resins, the acrylate-based UV-curable composite resins showed facile workability by UV nanoimprinting. The epoxy-based UV-curable composite resins formed pattern shapes independent of the weight fraction of ZrO2-NPs. These results indicated that the acrylate-based and epoxy-based composite films with optical transparency, refractive index controllability, and workability had potential as optical materials of optical devices and as resist materials for dry etching.
Enhanced Fluorescence by Controlled Surface Roughness of Plastic Biochip
Authors: Kim Dong-Jin , Lee Jung-Hwan , Cho Si-Hyeong , Rizwan Muhammad , Venkatesh R. Prasanna , Chung Bong Guen , Park Jin-Goo
Published: June 2011

Fluoroimmunoassay is one of the protein detection methods in which the most critical parameter is fluorescence intensity as it determines the sensitivity of the analysis. In this study, cyclic olefin copolymer (COC) based plastic biochips of various thicknesses were fabricated from 304 SS (Stainless Steel) molds using imprinting technique. The effect of surface roughness of COC biochip on the enhancement of fluorescence intensity was investigated. The fluorescence intensity reached the maximum value at optimum value of surface roughness without significantly affecting the auto-fluorescence value. The process proposed in this technique is simple, low cost yet highly sensitive for protein detection.
Design and Fabrication of Quartz Micro-Electro-Mechanical System-Based Double-Ended Tuning Fork with Variable Sections
Authors: Liang Jinxing , Li Xuefeng , Li Hongsheng , Ni Yunfang , Li Kunyu , Huang Libin , Ueda Toshitsugu
Published: June 2011

In this paper, we report a novel double-ended tuning fork (DETF) with variable sections. The DETF is fabricated using a quartz micro-electro-mechanical system (MEMS) technique and packaged using the flip chip technique. The central part of the vibration beam is thinned to enhance the force-frequency sensitivity but not decrease the vibration frequency. The mechanical quality factor (Q value) can also be maintained, which determines the mechanical noise performance. Three types of DETF are designed and fabricated with a fixed beam length of 4 mm. The vibration characteristics (vibration frequency, Q value, and equivalent circuit parameters) are evaluated using an impedance analyzer 4294A. The finite element method (FEM) is used to simulate the natural frequency and force-frequency sensitivity. For the natural frequencies, the experimental results agreed well with the simulation results. High Q values are achieved for all the DETFs, which are 9924, 7083, and 6335. By multiplying the force-frequency sensitivity (ΔF) by the measured Q values, the performance of the new DETF structure can be improved by 1.9 times.
Torsion Fatigue Testing of Polycrystalline Silicon Cross-Microbridge Structures
Authors: Hung Jeng-Nan , Hocheng Hong , Sato Kazuo
Published: June 2011

In the rapid advancement of micro/nano-electro-mechanical systems (MEMS/NEMS) technology, however, the reliable applications lie in the characterization of the mechanical fatigue properties of the micro/nano-structures. This paper presents the fatigue life of polycrystalline silicon (poly-Si) cross-microbridge in torsion. The torsion testing specimens are fabricated by surface and bulk micromachining. In addition, the stresses of cross-microbridge structures are investigated at various dimensions. The numerical tool ANSYS is applied to calculate the stress distribution of the testing structure. The experimental fatigue life lies between 7.78×104–1.48×107cycles in use of the MTS Tytron 250 microforce testing system. The collective plot of poly-Si fatigue including the results of torsion will provide the MEMS device designer and researcher a good reference in the future applications.
Resistance Formed in Thermoplastic Resin Substrate by Laser-Assisted Micro Powder Jet Implantation
Authors: Suzuki Katsuhiko , Saito Taku , Sugai Toru , Watanabe Shouta , Kameya Shoutaroh , Miura Kaichi , Kuriyagawa Tsunemoto
Published: June 2011

The C–SnO2 mixed particles and C–Ni mixed perticles have been implanted into a poly(oxymethylene) substrate and a poly(phenylene sulfide) thermoplastic resin substrate by using a laser-assisted powder jet for the formation of the resistances by those particles. These mixed powders were jetted using Ar gas and were implanted into the substrate by irradiating a green laser of CW type with powers of 210, 480, and 700 mW on the substrate kept at a constant moving speed. The laser was condensed at the same or nearly the same spot as the powder jetted on the substrate. It was found that the values of conductance and conductivity changed by the implantation of the powder of the weight fraction of SnO2 or carbon in the substrate in the wide range of 6 orders, and that the logarithm of these conductance and conductivity was proportional to the weight fraction of carbon and SnO2, which showed the percolation phenomenon in the two mixed particles system. The resistance showed similar frequency dependence to the commercial carbon resistance. There was little frequency change of the implanted resistance using the ditch compared with that without the ditch.
Evanescent-Wave-Driven Microrotors Produced by Two-Photon Microfabrication
Authors: Murakami Soichiro , Ikegame Masaki , Okamori Kazuaki , Maruo Shoji
Published: June 2011

In this study, we have developed evanescent-wave-driven microrotors by two-photon microfabrication. The evanescent-wave-driven microrotors are located on the surface of a high-refractive-index substrate attached to a prism. By illuminating a laser beam at an angle greater than the critical angle, evanescent waves are generated under the microrotors. When the laser beam is scattered by the blades of the microrotors, the microrotors are affected by radiation pressure. As a result, the microrotors can be rotated by evanescent waves. We designed an efficient microrotor with grating-like blades by electromagnetic field simulation. In our simulation, the optical torque exerted on the microrotor with grating-like blades is more than 5 times as large as that of a microrotor with rectangular blades. In our experiments, it was also demonstrated that the microrotor with grating-like blades could be rotated faster than the microrotor with rectangular blades. The evanescent-wave-driven microrotors will be applied to optically driven lab-on-a-chip devices.