bluuebunny/crossref_metadata_2025 huggingface dataset:
Stress, hassles and variations in alcohol consumption, food choice and physical exercise: A diary study
Authors: Steptoe Andrew , Lipsey Zara , Wardle Jane
Published: June 2011

Objectives. To assess the impact of daily life‐stress on behaviours (alcohol consumption, food choice and physical exercise) that influence health risk.

Method. Twenty‐three nurses and 21 teachers completed daily assessments of mood, alcohol and food intake, together with weekly measures of hassles, perceived stress, anxiety, depression and exercise behaviour, over an eight‐week period. Comparisons were made between the two highest and two lowest perceived stress weeks.

Results. Work and home‐related hassles were more frequent on high than low stress weeks, and anxiety and depression levels were greater, even after controlling for negative affectivity. Participants who drank alcohol to cope showed increases in consumption between low and high stress weeks. ‘Fast food’ was eaten more frequently during high stress weeks. People who reported that mood control was an important influence on their choice of food showed increases in the amount of cheese they ate, and greater consumption of sweet foods. There were no differences in exercise frequency or duration with changes in perceived stress.

Conclusions. Diary studies allow changes in health behaviour with life‐stress to be assessed naturalistically. The impact of stress depends on the moderating effects of motives and coping expectancies associated with specific behavioural domains. Some responses may be prejudicial to long‐term health risk.
Miscarriage: Is vividness of visual imagery a factor in the grief reaction of the partner?
Authors: Johnson Martin P. , Puddifoot John E.
Published: June 2011

Objectives. In the context of recent findings concerning the unexpressed psychological reactions of men to their partner's miscarriage, this study explores the role of visual imagery in mediating this reaction.

Design. Questionnaire data from 158 male partners of women who had miscarried prior to the start of the 25th week of pregnancy were collected with a view to exploring the relation of vividness of visual imagery within this cohort to their subsequent grief response.

Methods. Volunteers recruited via referrals from general hospitals and general practices in the North East and Midlands regions of England, were administered the Vividness of Visual Imagery Questionnaire, a modified object‐specific form, i.e. the Baby Vividness of Visual Imagery Questionnaire, and the Perinatal Grief Scale.

Results. It was found that men with ‘unvivid’ visual imagery were less likely to have seen an ultrasound scan of their unborn child. When men were compared by the length of gestation at which the miscarriage occurred there was not a significant difference in vividness of visual imagery. Those men exhibiting vivid imagery exhibited significantly higher levels of measured grief when their partner miscarried than those of lower or unvivid imagery.

Conclusions. These findings suggest that vivid visual imagery assisted or oriented men towards a sense of baby (or perceived foetal ontology) early in pregnancy, and in consequence they appeared at greater risk of negative impact following their partner's miscarriage.
The relationship between psychological factors and recurrent genital herpes simplex virus
Authors: Shah D. , Button J. C.
Published: June 2011

Purpose. This paper reviews the relationship between psychological factors and recurrent genital herpes simplex virus (HSV).

Method. Studies for the review were selected via computerized literature searches and were included if they specifically examined the relationship between genital HSV recurrence and psychological factors. Twenty‐nine studies addressing this relationship are evaluated and discussed.

Findings. Factors reported to be associated with recurrences include depression, stress, coping strategies, social support and illness vulnerability. However, findings are inconsistent due to variations in study design.

Conclusions. In general, the literature suggests that exposure to psychological stressors alone is not sufficient to trigger HSV recurrence. Although a correlation between psychological factors and number of recurrences exists, it may be that recurrences cause greater stress and depression, or that a third factor puts people at greater risk of both stress and recurrences. Personality traits, coping mechanisms and interpersonal factors, also determine the extent of the impact of the stressor on the individual. Further studies are needed to address these factors and control for the variations in designs found in the current literature.
Correlates of psychological distress in relation to male infertility
Authors: Band Dawn A. , Edelmann Robert J. , Avery Susan , Brinsden Peter R.
Published: June 2011

Objectives. To investigate, within a stress and coping framework, the existence, extent and predictors of psychological distress in a sample of men with a diagnosis of sole male factor infertility.

Design. A cross‐sectional design was used to investigate correlates of distress.

Method. Questionnaires were sent to 130 men with a diagnosis of sole male factor infertility who were attending a specialist infertility clinic for primary infertility. Fifty‐one men responded, giving a 39 per cent response rate. In addition to completing the Beck Depression Inventory, State‐Trait Anxiety Inventory, Perceived Stress Scale, Ways of Coping Questionnaire and a measure of infertility‐related distress, participants also provided data concerning their age, their partner's age, and the duration and severity of infertility.

Results. There was evidence for elevated depression and state anxiety in some infertile males. Three significant predictors of depression were identified: an anxious disposition, a tendency to appraise situations as stressful and an avoidant coping style. In relation to state anxiety two predictors were identified: trait anxiety and failure to seek social support.

Conclusions. Male infertility is perceived as stressful and can be associated with a greater risk of psychopathology in some cases, particularly for those men with an enduringly anxious disposition, an inability to seek social support and those who engage in avoidance coping strategies. Identification of factors predictive of distress will enable professionals to effectively direct psychological interventions to vulnerable individuals.
When small losses do not loom larger than small gains: Effects of contextual autonomy support and goal contents on behavioural responses to small losses and small gains
Authors: Chatzisarantis Nikos L. D. , Kee Ying Hwa , Thaung Hannah Kyaw , Hagger Martin S.
Published: June 2011

Based on the tenets of self‐determination theory, the present studies examined the moderating effects of interpersonal contexts or goal conditions that afforded satisfaction of psychological needs on loss aversion effects. We hypothesized that behavioural responses to small losses would be stronger relative to behavioural responses to small gains under goal conditions or interpersonal contexts that did not support psychological needs. We also expected the effect to be minimized under goal conditions or interpersonal contexts that supported psychological needs. This prediction was supported in Study 1 that induced satisfaction of psychological needs via manipulations of interpersonal context and in Study 2 that instigated satisfaction of psychological needs via manipulations of goal contents. In addition, Studies 1 and 2 demonstrated that psychological needs reduced the classic loss aversion effect by increasing behavioural and affective responses to gains and not because psychological needs altered affective or behavioural responses to losses. Results of the present studies support the conclusion that contextual autonomy support and the distinction between intrinsic and extrinsic goals proposed by self‐determination theory define a boundary condition of the loss aversion hypothesis.
Group music therapy for patients with persistent post‐traumatic stress disorder – an exploratory randomized controlled trial with mixed methods evaluation
Authors: Carr Catherine , d’Ardenne Patricia , Sloboda Ann , Scott Carleen , Wang Duolao , Priebe Stefan
Published: June 2011

Objectives. Not all patients with post‐traumatic stress disorder (PTSD) respond to cognitive behavioural therapy (CBT). Literature suggests group music therapy might be beneficial in treating PTSD. However, feasibility and effectiveness have not been assessed. The study objectives were to assess whether group music therapy was feasible for patients who did not respond to CBT, and whether it has an effect on PTSD symptoms and depression.

Design. The study employed mixed methods comprising of an exploratory randomized controlled trial, qualitative content analysis of therapy, and patient interviews.

Method. Patients with significant PTSD symptoms (n= 17) following completion of CBT were randomly assigned to treatment (n= 9) or control groups (n= 8). The treatment group received 10 weeks of group music therapy after which exit interviews were conducted. Control group patients were offered the intervention at the end of the study. Symptoms were assessed on the Impact of Events Scale‐Revised and Beck Depression Inventory II at the beginning and end of treatment.

Results. Treatment‐group patients experienced a significant reduction in severity of PTSD symptoms (−20.18; 95% confidence interval [CI]: [−31.23, −9.12]) and a marginally significant reduction in depression (−11.92; 95%CI: [−24.05, 0.21]) at 10 weeks from baseline compared to the control. Patients viewed music therapy as helpful and reported experiences concur with current literature.

Conclusions. Group music therapy appears feasible and effective for PTSD patients who have not sufficiently responded to CBT. Limitations include the small sample size and lack of blinding. Further research should address these limitations, test sustainability, and identify specific factors that address symptoms in treatment.
Economic burden of physical activity–related injuries in Dutch children aged 10–12
Authors: Collard Dorine C M , Verhagen Evert A L M , van Mechelen Willem , Heymans Martijn W , Chinapaw Mai J M
Published: June 2011

Background

Injuries in children occur most often in physical activity–related activities. A lot of these injuries result in direct and indirect costs. A detailed overview of the economic burden of those injuries in children is lacking.

Method

A prospective study was conducted with 996 children in Dutch primary schools to describe the economic burden of injuries that occur during organised sports, leisure time and physical education (PE) class activities. Injuries were continuously monitored by PE teachers during the school year 2006–2007. An injury was recorded if it occurred during PE class, leisure time or organised sports activity and caused the child to at least stop the current activity. If an injury was recorded, parents received a cost diary to report the direct and indirect costs of the child's injury. Costs were collected from a societal perspective.

Results

During one school year, a total of 119 injuries were reported by 104 children. The mean total costs as a result of an injury were €188±317. The mean direct costs as a result of an injury were much higher than the mean indirect costs (€131±213 and €57±159, respectively). The highest costs were found for upper extremity and leisure time injuries.

Conclusion

Physical activity–related injuries are common in children and result in medical costs. Injuries that lead to the highest costs are those that occur during leisure time activities and upper extremity injuries. Intervention programmes for children to prevent upper extremity injuries and leisure time activity injuries may reduce direct (ie, healthcare) and indirect costs.

Trial registration: ISRCTN78846684
A STUDY ON MAGNETIC PROPERTIES OF Cu-DOPED GaN
Authors: SHI LI-BIN , YUAN HONG-KUAN
Published: June 2011

Using the first principle method based on density functional theory (DFT), we have studied the magnetic properties in Cu -doped GaN . The result shows that Cu in GaN exhibits spontaneous spin polarization. The energies of ferromagnetism (FM) and antiferromagnetism (AFM) coupling are calculated for eleven different configurations. It is found that Cu -doped GaN has a FM ground state. It is not found that Cu atoms have a clear clustering tendency. Origin of FM properties is also explained by energy level coupling model. In the paper, we also investigate the effect of nitrogen, gallium vacancies and carbon impurities on magnetic properties. The results show that nitrogen, gallium vacancies and carbon impurities cannot enhance FM coupling of Cu -doped GaN . In addition, exchange coupling coefficient and Curie temperature are also investigated. The Cu -doped GaN is proposed to be weak ferromagnetism according to Curie temperature and magnetic moment. The present study provides some theoretical understanding for the experiments on Cu -doped GaN .
A CORPUS BASED TECHNIQUE FOR REPAIRING ILL-FORMED SENTENCES WITH WORD ORDER ERRORS USING CO-OCCURRENCES OF N-GRAMS
Authors: ATHANASELIS THEOLOGOS , MAMOURAS KONSTANTINOS , BAKAMIDIS STELIOS , DOLOGLOU IOANNIS
Published: June 2011

There are several reasons to expect that recognising word order errors in a text will be a difficult problem, and recognition rates reported in the literature are in fact low. Although grammatical rules constructed by computational linguists improve the performance of a grammar checker in word order diagnosis, the repairing task is still very difficult. This paper describes a method to repair any sentence with wrong word order using a statistical language model (LM). A good indicator of whether a person really knows a language is the ability to use the appropriate words in a sentence in correct word order. The "scrambled" words in a sentence produce a meaningless sentence. Most languages have a fairly fixed word order. This paper introduces a method, which is language independent, for repairing word order errors in sentences using the probabilities of most typical trigrams and bigrams extracted from a large text corpus such as the British National Corpus (BNC).
ASSESSING INSECT GROWTH USING IMAGE ANALYSIS
Authors: PATTEN TOM , LI WENJING , BEBIS GEORGE , HUSSAIN MUHAMMAD
Published: June 2011

Image analysis represents an invaluable tool in processing and analyzing biological data in an expeditious and reliable way. This paper describes the design and implementation of an image analysis system for the automatic assessment of the growth of Heliothis-zea insects from color images. Specifically, the Heliothis zea is a corn earworm eating corn crops. Biotech researchers are interested in developing insecticidal bio-toxins with the best performance to kill or stunt the growth of the pest. Currently, assessing the effectiveness of different bio-toxin solutions is done mostly manually by biotech experts. The goal of this study is to investigate the use of image analysis for automating and improving the efficiency of this process. In this context, we have developed a prototype system for assessing insect growth from color images which contains three main stages: (1) insect segmentation from background, (2) region processing and feature extraction, and (3) categorization of insect growth. A probabilistic model based on mixtures of Gaussians has been adopted to segment the insect images. Also, back-propagation neural networks have been trained to classify the instar stage and life stage. The proposed system has been evaluated on a set of real images.
CLUSTERING AS A PRIOR STEP TO CLASSIFICATION: AN EMPIRICAL STUDY
Authors: KYRIAKOPOULOU ANTONIA , KALAMBOUKIS THEODORE
Published: June 2011

This paper addresses the problem of learning to classify texts by exploiting information derived from clustering both training and testing sets. The incorporation of knowledge resulting from clustering into the feature space representation of the texts is expected to boost the performance of a classifier. We present an empirical study of the proposed algorithm on a variety of datasets. We attempt to answer various questions such as the effect of independence or relevance amongst features, the effect of the size of the training set and the effect of noise. The results are encouraging, revealing that information resulting from clustering can create text classifiers of high-accuracy.
NANOSCIENCE AND NANOTECHNOLOGY FOR MEMORY AND DATA STORAGE
Authors: TAHMASEBI T. , PIRAMANAYAGAM S. N.
Published: June 2011

Data storage is one area of technology where nanotechnology has been used even before the term nanotechnology became very popular. The magnetic recording media — the disk that stores information in hard disk drives — used nanotechnology in the late 1990s, in the form of grains which are 15 nm or less in diameter (the grains in current technology are about 8 nm in diameter). The reading sensors of hard disk also make use of thin nanostructures in several dimensions to read information from the recording media. This paper introduces the technology behind the magnetic random access memory and related topics, which form the core of the symposium L of ICMAT 2011, which is titled "Memory, Nanomagnetics, Materials and Devices".
ENTANGLEMENT SWAPPING OF PAIR CAT STATES
Authors: ZHANG YE-QI , XU JING-BO
Published: June 2011

We investigate the entanglement swapping of the continuous variable states by taking the pair Schrödinger cat states as the input entangled states, in which the two-mode squeezed vacuum and the pair cat states serve as the quantum channel, respectively. The entanglement of the initial states as well as the final states is analyzed by adopting the logarithmic negativity as the measure of entanglement. The quantum teleportation task by exploiting the swapped states as the quantum channel is also considered, where a coherent state serves as the target state and the average fidelity is examined.
SCHEDULING WITH JOB CHECKPOINT IN COMPUTATIONAL GRID ENVIRONMENT
Authors: NANDAGOPAL MALARVIZHI , GAJALAKSHMI S. , UTHARIARAJ V. RHYMEND
Published: June 2011

Computational grids have the potential for solving large-scale scientific applications using heterogeneous and geographically distributed resources. In addition to the challenges of managing and scheduling these applications, reliability challenges arise because of the unreliable nature of grid infrastructure. Two major problems that are critical to the effective utilization of computational resources are efficient scheduling of jobs and providing fault tolerance in a reliable manner. This paper addresses these problems by combining the checkpoint replication based fault tolerance mechanism with minimum total time to release (MTTR) job scheduling algorithm. TTR includes the service time of the job, waiting time in the queue, transfer of input and output data to and from the resource. The MTTR algorithm minimizes the response time by selecting a computational resource based on job requirements, job characteristics, and hardware features of the resources. The fault tolerance mechanism used here sets the job checkpoints based on the resource failure rate. If resource failure occurs, the job is restarted from its last successful state using a checkpoint file from another grid resource. Globus ToolKit is used as the grid middleware to set up a grid environment and evaluate the performance of the proposed approach. The monitoring tools Ganglia and Network Weather Service are used to gather hardware and network details, respectively. The experimental results demonstrate that, the proposed approach effectively schedule the grid jobs with fault-tolerant way thereby reduces TTR of the jobs submitted in the grid. Also, it increases the percentage of jobs completed within specified deadline and making the grid trustworthy.
Thermomechanical Analysis on the Phase Stability of Nitrogen-Doped Amorphous Ge2Sb2Te5 Films
Authors: Park Il-Mok , Cho Ju-Young , Yang Tae-Youl , Park Eun Soo , Joo Young-Chang
Published: June 2011

The phase stability of amorphous Ge2Sb2Te5 (GST) films affects the performance and reliability of phase change memory (PRAM) devices. The viscosity and the glass forming ability of nitrogen (N)-doped amorphous GST films were investigated in terms of thermomechanical behavior using wafer curvature measurements. The viscosity which increased by two orders of magnitude was observed in the N-doped amorphous GST film by measuring the stress relaxation accompanied by bimolecular structural relaxation. The glass forming ability (ΔT
x), difference between the glass transition temperature (T
g) and the crystallization temperature (T
c), of GST increased as the nitrogen contents increased. These increases in the viscosity and ΔT
x indicate the retardation of atomic diffusion in amorphous GST and the stabilization of the amorphous phase.
Liquid Phase Deposition of Carbon Nitride Films for Application as Low-k Insulating Materials
Authors: Higashi Mikiteru , Kiyota Hideo , Kurosu Tateki , Chiba Masafumi
Published: June 2011

CN
x
films are fabricated using liquid phase deposition by applying a DC bias voltage to Si substrates immersed in acrylonitrile. X-ray photoelectron spectra reveal that C, N, and O are major components of the deposited films. From analysis of C 1s and N 1s spectra, the major bonding state in the CN
x
film is attributed to a mixture of C≡N and partially hydrogenated C=N bonds. Metal–insulator–semiconductor capacitors incorporating the CN
x
insulating layers are fabricated to evaluate the electrical properties of the deposited films. The lowest dielectric constant k of the CN
x
film is determined to be 2.6 from the accumulation capacitance and the thickness of the film, suggesting that the CN
x
film formed by liquid phase deposition is a promising low-k material for use in ultralarge-scale integration multilevel interconnections.
Current-Controlled Tunable Fiber Multiwavelength Filter Based on Polarization-Diversity Loop Structure
Authors: Choi Daeho , Lee Yong Wook
Published: June 2011

In this paper we have demonstrated absolute wavelength tuning in an optical fiber multiwavelength filter based on a polarization-diversity loop structure by controlling electrical currents injected into enameled wires wound on polarization-maintaining fibers (PMFs), that is, adjusting Joule heat generated from current-flowing enameled wires. The proposed filter consists of a four-port polarization beam splitter, a half-wave plate, a quarter-wave plate, and PMFs. The wavelength shifts of spectral dips in the transmission spectra of the fabricated filter were investigated with the variation of the injection current. The absolute wavelength of the filter could be controlled in proportion to the square of the injection current with considerably good linearity, and the wavelength tuning sensitivity was evaluated as ∼83.5 nm/A2 with respect to the injection current.
Stability Improvement of a Twisted-Vertical Aligned Nematic Liquid Crystal Cell
Authors: Peng Cheng-Chung , Hsu Kuei-Chu , Huang Shun-Jian , Wu Jin-Jei
Published: June 2011

A patterned twisted-vertical aligned (PTVA) nematic liquid crystal cell with an indium–tin-oxide (ITO) electrode that is patterned with a fine slit and hole is demonstrated to exhibit excellent electro-optical characteristics of high transmittance with stable liquid crystal orientation. The proposed PTVA cell has a similar liquid crystal (LC) director distribution to that of the continuum domain TVA (CDTVA) cell, but with a more stable optical schlieren. The proposed PTVA cell has a maximum transmittance that is about 24% higher than that of a PVA cell.
Effect of Ni Layer Thickness on Cu-Based {100}<001 > Textured Substrate for Coated Conductor
Authors: Kashima Naoji , Kubota Shuichi , Shima Kunihiro , Doi Toshiya , Nagaya Shigeo , Inoue Masayoshi , Kiss Takanobu
Published: June 2011

We prepared substrates with the structure electroplated Ni/textured Cu/stainless steel (SS) and clarified the effect of the electroplated Ni layer thickness on the substrate performance by investigating the dependences of the degree of crystal orientation and the surface roughness on the Ni layer thickness. It was confirmed that the orientation of the Ni layer did not significantly change up to a thickness of 10 µm; however, the surface roughness of the Ni layer decreased when the layer thickness exceeded 3 µm. From these results, in order to achieve a high critical current density (J
c) on a Cu substrate, it is suggested that the preferred maximum thickness of the Ni layer on the textured Cu should be approximately 3 µm. In addition, the possibility of broad availability for the coating process was investigated by estimating the Cu concentration on the surface of a 3-µm-thick Ni layer.
Green/Red Electroluminescence from Metal–Oxide–Semiconductor Devices Fabricated by Spin-Coating of Rare-Earth Organic Compounds on Silicon
Authors: Ohzone Takashi , Matsuda Toshihiro , Hase Souta , Nohara Shingo , Iwata Hideyuki
Published: June 2011

Current–voltage (I
G–V
G) characteristics and green/red electroluminescence (EL) from metal–oxide–semiconductor (MOS) devices with indium–tin oxide (ITO)/[(Tb/Ba–Si–O)/(Tb/Eu–Si–O)] layers/n+-Si substrate are reported. The (Tb/Ba–Si–O) and (Tb/Eu–Si–O) layers were fabricated from the mixtures of organic liquid sources of (Tb+Ba) and (Tb+Eu), respectively, which were spin-coated on the n+-Si substrate and annealed at 850 °C for 30 min in air. I
G currents under EL emission correspond to Fowler–Nordheim (FN) tunnel current. The MOS devices with the (Tb/Ba)–Si–O layer and the (Tb/Eu)–Si–O layer emitted green and red EL, which originated from the intrashell transitions of 5D4–7F
J
(J = 6, 5, 4, and 3) of Tb3+ ions and 5D0–7F
J
(J = 1, 2, 3, and 4) of Eu3+ ions, respectively. EL intensity increased proportionally to I
G to the n-th power, where n was about 1.3, and the EL spectra were independent of the currents. The oxide layers on the Si substrate for the green and the red devices have the total thicknesses of about 40 and 30 nm, which consist of [Tb2O3 and (Tb/Ba–Si–O)] and [Tb2O3/Eu2O3 and (Tb/Eu–Si–O)] mixtures, respectively.
Tunneling Resistances Associated with Classical-to-Quantum Fluctuations in Single Point-Contact Junction
Authors: Joung Chung Dau , Chung Tao Hsiang , Ho I Lin , Chen Chii Dong
Published: June 2011

The studied single point-contact junction, which bridges superconducting (Pb) and ferromagnetic (Co) granular thin films, presents magnetic-field-insensitive nonlinear resistances versus biases at low temperature. This work shows that the disordered granules can cause random charge localizations δq as well as the resulting offset-bias δV=δq/C
j across the junction capacitance C
j, and thereby invalidate the (magnetic-field-dependent) energy-level structures of materials Pb and Co. Simultaneously, the disorder brings in the fundamental influences of the non-equilibrium fluctuations. A simple model by golden approximation is then addressed to demonstrate the basic fluctuation behaviors. The results indicates that quantum and thermal fluctuations mainly drive the behaviors of the differential resistances of this disordered system as the experimental observations.
Crystal Quality of Naphtacene Single Crystals Obtained by Physical Vapor Transport Method
Authors: Jo Sadaharu , Takada Noriko , Takenaga Mitsuru
Published: June 2011

The crystal quality of naphtacene single crystals obtained by the physical vapor transport method using a horizontally arranged furnace has been examined by morphological investigation, the Laue method, and diffractometry. Using the physical vapor transport method, two types of single crystals were obtained: large plateletlike crystals and small three-dimensional (3D) crystals. The experimental results of the morphological investigation and diffractometry suggest that both types of crystal are of possess high quality; however, the result for the Laue method suggests that large platelet-like crystals are of possess excellent quality and that small crystals are of inferior quality. It appears that small crystals cannot grow futher size because they include a large strain.
Growth Behavior of High-Indium-Composition InGaN Quantum Dots Using Growth Interruption Method
Authors: Zhao Wei , Wang Lai , Lv Wenbin , Wang Lei , Wang Jiaxing , Hao Zhibiao , Luo Yi
Published: June 2011

High-indium-composition InGaN quantum dots (QDs) have been grown using a growth interruption method by metal organic vapor phase epitaxy. Effects of V/III ratio and temperature on the density, size, and formation mechanism of InGaN QDs by this method are investigated by atomic force microscopy and photoluminescence measurements. At a V/III ratio of 16600 and a temperature of 650 °C, adatoms can migrate on the surface and combine with each other to form QDs to relax stress when growth is interrupted. A lower V/III ratio of 8300 can increase the migration capability of adatoms, and stress is relaxed by formation of dots when the first nominal InGaN layer is grown, which results in the lower density and higher indium composition of QDs after the second InGaN layer growth. Three-dimensional growth can be enhanced and the density of QDs increases at a temperature of 600 °C.
D Abstraction by H at a Ru(001) Surface Covered with D2O Molecules
Authors: Yamauchi Takashi , Mine Kazuyuki , Namiki Akira
Published: June 2011

The mechanism for the hydrogen abstraction (ABS) reaction at the D2O covered Ru(001) surface was investigated. HD desorption rates were measured at θD2O≤3 ML. The apparent reaction order of HD desorption was approximately 1.7, which is almost equal to the value of 1.6±0.1 measured on clean Ru(001) surfaces. The HD desorption rates were analyzed using the same equation previously proposed for the clean Ru surface, which consists of three rate terms due to the hot atom (HA), hot complex (HC) and Langmuir–Hinshelwood (LH) mechanisms. The surface area enclosed by the hexagonal ring structure of the first water layer is sufficiently large to assure complete energy relaxation of excess H atoms from the hot atom states at which HA-mediated ABS occurs to the supersaturation coverage of thermodynamically unstable adatoms, which results in ABS by the LH mechanism.
Electrical and Photoconductive Properties at 1.8 K of Germanium p+–i Junction Device Fabricated by Surface-Activated Wafer Bonding
Authors: Kaneda Hidehiro , Wada Takehiko , Oyabu Shinki , Kano Ryoko , Kiriyama Yuichi , Hattori Yasuki , Suzuki Toyoaki , Ide Kensuke , Kato Masahiro , Watanabe Kentaroh
Published: June 2011

We have evaluated the electrical and photoconductive properties of a Ge p+–i junction device, fabricated by surface-activated wafer bonding (SAB) technology, at temperatures of 1.8–5 K. The p+–i junction consists of two bonded layers, Ge heavily doped with Ga at a concentration of 1×1016 cm-3 and non-doped intrinsic Ge. The bonded Ge wafer was diced to a 1-mm cubic test element having two layers of thickness 0.5 mm and two facing electrodes. We measured the current–voltage characteristics of the device at 1.8–5 K, and its photoresponses against stepped illumination with far-infrared light at 1.8 K. The device shows the expected cryogenic performance in terms of electrical and photoconductive properties, demonstrating the promising applicability of SAB-processed Ge p+–i junction devices in blocked-impurity-band-type Ge detectors.
Capacitive Imaging of Graphene Flakes on SiO2 Substrate
Authors: Naitou Yuichi , Ogiso Hisato
Published: June 2011

We used scanning capacitance microscopy (SCM) for the local electrical imaging of graphene flakes on a SiO2 substrate. As a result of analyzing the dependence of the SCM measurements on the area of thin graphite nanoislands together with the observed difference in contrast of SCM images related to the graphene layer's thickness, we have concluded that the SCM measurements can selectively image high-conductivity few-layer graphene (FLG) flakes on an insulating substrate without having to fabricate external electrical contacts on the graphene. Our technique is a simple way to explore the conductive properties of low-dimensional systems on an insulating substrate with nanoscale resolution.
Application of Extreme Ultraviolet Lithography to Test Chip Fabrication
Authors: Tawarayama Kazuo , Nakajima Yumi , Kyoh Suigen , Aoyama Hajime , Matsunaga Kentaro , Tanaka Satoshi , Magoshi Shunko
Published: June 2011

Extreme ultraviolet (EUV) lithography is considered to be the most promising technology for meeting the lithographic challenges posed by the next generation semiconductor design rule beyond a half pitch (hp) of 22 nm. A key area of the Selete EUV program is proof of manufacturability, which means verification of module integration for EUV lithography. To accomplish this, many technologies [e.g., mask, exposure tool, resist, optical proximity correction (OPC)] need to be developed and integrated. In this paper, we discuss the current status of each of them. To verify EUV's manufacturability, we applied EUV to test chip fabrication, metal wiring fabrication, and electrical measurement. The yield number of the hp 28 nm pattern is 70% after improving the resist and the etching process. These results show demonstrate that EUV lithography is a practical technology that is now suitable for semiconductor devices for 2x nm area.
Theoretical Study of Photoacid Generators for Extreme Ultraviolet Resist
Authors: Endo Masayuki , Tagawa Seiichi
Published: June 2011

We have investigated the reactivity of photoacid generators for extreme ultraviolet (EUV) exposure. Quantum chemical calculation was performed. As the secondary electron from the polymer in a resist causes the reaction of the photoacid generator, the reactivity of the photoacid generator is determined as its electron affinity. We optimized the molecular structure of the photoacid generator and calculated the electron affinity of the photoacid generator. We found that the incorporation of fluorine atoms enhances the reactivity of photoacid generators. The substituted position of fluorine atoms and population analysis of added electrons were also studied.
Preparation of Ultrahigh-Density Magnetic Nanowire Arrays beyond 1 Terabit/Inch2 on Si Substrate Using Anodic Aluminum Oxide Template
Authors: Shimizu Tomohiro , Aoki Kazumo , Tanaka Yoshinori , Terui Toshifumi , Shingubara Shoso
Published: June 2011

Ultrahigh-density Co nanowire arrays were fabricated by the combined use of the anodic aluminum oxide (AAO) template formed on a Si substrate and pulse DC electrodeposition. The AAO templates were prepared with the anodic voltages from 3 to 40 V, whose diameters were from 15 to 40 nm. Using the AAO template with an anodic voltage less than 3 V, the wire density exceeded 2.88 Tbit/in.2. The magnetic property of the nanowire arrays indicated a strong perpendicular magnetic anisotropy, and we observed the tendency of increase in coercivity with decreasing nanowire diameter.
Highly Conductive Vertically Aligned Carbon Nanotubes Grown on Mg0.3Zn0.7O Thin Film Template Using Thermal Chemical Vapour Deposition Method
Authors: Salina Muhamad , Mamat Mohamad Hafiz , Bakar Suriani Abu , Ahmad Rafidah , Siran Yosri Mohd , Rejab Syahril Anuar M. , Asis Ahmad Jais , Tahiruddin Shaharudin , Rusop Mohamad
Published: June 2011

Novel vertically aligned carbon nanotubes (VACNTs) were successfully grown on Mg0.3Zn0.7O thin film template. Current–voltage (I–V) characteristics of both VACNTs and VACNTs/Mg0.3Zn0.7O were measured where it first demonstrates that highly conductive VACNTs with more than 1 ×105 S cm-1 were achieved using Mg0.3Zn0.7O thin film template, though both samples showing only a small difference in the micro-Raman spectroscopy. This suggested that the used of Mg0.3Zn0.7O thin film template is capable of promoting the growth of VACNTs to have a smaller diameter and blocked the electrons' penetration into silicon that leads to highly conductive sample.
Proposal of Graphene Bandgap Control by Hexagonal Network Formation
Authors: Zou Liumin , Konishi Keita , Yoh Kanji
Published: June 2011

We propose a new approach to open the bandgap of graphene by fabricating a hexagonal nanoribbon network. We have successfully fabricated hexagonal graphene network pattern (GNP) out of exfoliated monolayer graphene by electron beam lithography. Transport characteristics were investigated using a top-gated Hall-bar device. The electron mobility of GNP with 40 nm ribbon width, d, was 452 cm2 V-1 s-1 at 90 K and on/off ratio of top-gated field-effect transistors (FET) exceeded 8.6 at room temperature, which shows significant improvement compared with on/off ratio of 2 in control sample without network pattern.
Fabrication of 10-nm-Order Block Copolymer Self-Assembled Nanodots for High-Density Magnetic Recording
Authors: Huda Miftakhul , Akahane Takashi , Tamura Takuro , Yin You , Hosaka Sumio
Published: June 2011

In this work, we investigated the fabrication of 10-nm-order block copolymer self-assembled nanodots using high-etching-selectivity polystyrene–poly(dimethylsiloxane) (PS–PDMS) block copolymers for high-density storage devices. We adopted PS–PDMS polymers with two different molecular weights of 13,500–4,000 and 11,700–2,900. With decreasing molecular weight, the nanodot size decreased from 12 to 10 nm, and the pitch correspondingly decreased from 22 to 20 nm. The PS–PDMS film thickness is the critical-factor to determine whether nanodot arrays can form on a large area or not. It was demonstrated that the thicknesses of 36 and 33 nm were optimal for the PS–PDMS polymers of 13,500–4,000 and 11,700–2,900, respectively. The limitation in the selection of PS–PDMS to form a smaller size of self-assembled nanodots is also predicted. This work promises to open way toward 1.6 Tbit/in.2 storage device with cheap cost production.
A Colloidal Route to Detection of Organic Molecules Based on Surface-Enhanced Raman Spectroscopy Using Nanostructured Substrate Derived from Aerosols
Authors: Gen Masao , Kakuta Hideo , Kamimoto Yoshihito , Lenggoro I. Wuled
Published: June 2011

A detection method based on the surface-enhanced Raman spectroscopy (SERS)-active substrate derived from aerosol nanoparticles and a colloidal suspension for detecting organic molecules of a model analyte (a pesticide) is proposed. This approach can detect the molecules of the derived from its solution with the concentration levels of ppb. For substrate fabrication, a gas-phase method is used to directly deposit Ag nanoparticles on to a silicon substrate having pyramidal structures. By mixing the target analyte with a suspension of Ag colloids purchased in advance, clotianidin analyte on Ag colloid can exist in junctions of co-aggregated Ag colloids. Using (i) a nanostructured substrate made from aerosol nanoparticles and (ii) colloidal suspension can increase the number of activity spots.
Paramagnetic Properties of Size-Controlled Squid Ink Particles Dispersed in Water
Authors: Matsuura Toshihiko , Shimoyama Yuhei , Kobayashi Takanori , Taya Yoshihiro , Ueno Takashi
Published: June 2011

The paramagnetic properties of size-controlled ink particles isolated from the ink sacs of squid were studied by electron spin resonance (ESR). ESR spectra of the large and small ink particles dispersed in water were successfully observed at room temperature. Both the ink particles in aqueous suspensions seemingly indicated similar ESR spectra consisting of a singlet with a slightly asymmetrical signal. The linewidth below saturation was almost the same in both the ink particles, but the linewidth of the small ink particle was obviously broadened with an increase in microwave power. On the other hand, the progressive microwave power saturation revealed a clear difference between the paramagnetic behaviors of the ink particles in aqueous suspensions and in solid states. In comparison with dehydrated samples, the ESR signals of the ink particles dispersed in water showed the inhomogeneous broadening and faster spin–lattice relaxation processes. The fundamental characteristics of size-controlled ink particles would serve as basic information for various applications.
Adsorption and Diffusion of Li and Ni on Graphene with Boron Substitution for Hydrogen Storage: Ab-initio Method
Authors: Park Hong-Lae , Yoo Dong Su , Chung Yong-Chae
Published: June 2011

Based on first-principles plane wave calculations, it has been shown that boron-substituted graphene with Li metal atom adsorption can be used as a high-capacity hydrogen storage material. Boron substitution in graphene increases Li and Ni metal adsorption energy, which is much larger than that in pure graphene. The diffusion characteristics of metal atoms were also investigated. The diffusion energy barrier of Ni metal is stronger than that of Li metal, but the cohesive energy of Ni bulk is much larger. Then, the large-scale metal adsorption behavior on boron-substituted graphene was calculated by the molecular dynamics (MD) method. Moreover, hydrogen adsorption behavior on Li metal atoms is investigated. It is found that Li and Ni adatoms dispersed on the double side of graphene can absorb up to eight hydrogen molecules corresponding to 13.2 and 7.9% hydrogen storage capacities, respectively.
Fabrication of Multi-Functional Optical Films by Using a Ultraviolet Curing Roll-to-Roll System
Authors: Chuang Cheng-Hsin , Tsai Sung-Wen , Lin Jeng-Feng , Chen Chang-Pen
Published: June 2011

This paper presents a roll-to-roll process (R2R), combined with UV-curable molding technology, for the production of multi-functional optical films in large area without seams. Firstly, the spherical microlens array is analyzed by using optical analysis software (ASAP). Then, a seamless roller mold with a concave microlens array is utilized for pattern transfer onto a PET film coated with UV resin. Imprinting tests for the PET substrates are carried out under different web tensions (0.29–1.45 kg/cm) and rolling speeds (0.28–0.84 m/min). According to the experimental results, a multi-functional film without any defects and its replication almost duplicate the microstructures on the roller mold if the rolling speed is low and the web tension is sufficiently high. In addition, the optical performance of the multi-functional films is measured by using a luminance inspection system and haze meter. The measurement results show a luminance gain of approximately 1.19 and a haze of 79–86%. Consequently, the present study can provide a guideline for fabrication at a low-cost and for large-area multi-functional optical films by using a UV-curing R2R process.
Resist Pattern Inspection Using Fluorescent Dye-Doped Polystyrene Thin Films in Reactive-Monolayer-Assisted Thermal Nanoimprint Lithography
Authors: Kubo Shoichi , Sato Yuko , Hirai Yoshihiko , Nakagawa Masaru
Published: June 2011

Fluorescent dye-doped polystyrene (PS) thin films were studied for defect inspection of PS resist patterns by fluorescence microscopy in reactive-monolayer-assisted thermal nanoimprint lithography using a photoreactive monolayer. A fluorescent dye of N,N '-bis(2,6-dimethylphenyl-perylene-3,4,9,10-tetracarboxylic diimide doped in a PS resist thin film maintained an almost identical fluorescence intensity after annealing at a temperature necessary for thermal nanoimprinting. To avoid degradation of a dye doped in a resist film owing to exposure to ultraviolet light for preparing a PS graft layer on the photoreactive monolayer, a double coating method for preparing a dye-doped PS resist layer on the PS graft layer was adopted. It was demonstrated by the fluorescent microscopic defect inspection that resist pattern defects due to unleveled residual layers after thermal nanoimprinting were significantly decreased by adding low-molecular-weight PS (5,100 g mol-1) to high-molecular-weight PS (360,000 g mol-1). The rheological study revealed that the low-molecular-weight PS obviously functioned as a plasticizer, which flattened residual layers and decreased their thickness.
Application of Organosilane Monolayer Template to Quantitative Evaluation of Cancer Cell Adhesive Ability
Authors: Tanii Takashi , Sasaki Kosuke , Ichisawa Kota , Demura Takanori , Beppu Yuichi , Vu Hoan Anh , Chi Hoan Thanh , Yamamoto Hideaki , Sato Yuko
Published: June 2011

The adhesive ability of two human pancreatic cancer cell lines was evaluated using organosilane monolayer templates (OMTs). Using the OMT, the spreading area of adhered cells can be limited, and this enables us to focus on the initial attachment process of adhesion. Moreover, it becomes possible to arrange the cells in an array and to quantitatively evaluate the number of attached cells. The adhesive ability of the cancer cells cultured on the OMT was controlled by adding (-)-epigallocatechin-3-gallate (EGCG), which blocks a receptor that mediates cell adhesion and is overexpressed in cancer cells. Measurement of the relative ability of the cancer cells to attach to the OMT revealed that the ability for attachment decreased with increasing EGCG concentration. The results agreed well with the western blot analysis, indicating that the OMT can potentially be employed to evaluate the adhesive ability of various cancer cells.
Extended-Gate Metal Oxide Semiconductor Field Effect Transistor-Based Biosensor for Detection of Deoxynivalenol
Authors: Kwon Insu , Lee Hee-Ho , Choi Jinhyeon , Shin Jang-Kyoo , Seo Sang-Ho , Choi Sung-Wook , Chun Hyang Sook
Published: June 2011

In this work, we present an extended-gate metal oxide semiconductor field effect transistor (MOSFET)-based biosensor for the detection of deoxynivalenol using a null-balancing circuit. An extended-gate MOSFET-based biosensor was fabricated by a standard complementary metal oxide semiconductor (CMOS) process and its characteristics were measured. A null-balancing circuit was used to measure the output voltage of the sensor directly, instead of measuring the drain current of the sensor. Au was used as the gate metal, which has a chemical affinity with thiol, which leads to the immobilization of a self-assembled monolayer (SAM) of mercaptohexadecanoic acid (MHDA). The SAM was used to immobilize the anti-deoxynivalenol antibody. The carboxyl group of the SAM was bound to the anti-deoxynivalenol antibody. The anti-deoxynivalenol antibody and deoxynivalenol were bound by their antigen-antibody reaction. The measurements were performed in phosphate buffered saline (PBS; pH 7.4) solution. A standard Ag/AgCl electrode was employed as a reference electrode. The bindings of a SAM, anti-deoxynivalenol antibody, and deoxynivalenol caused a variation in the output voltage of the extended-gate MOSFET-based biosensor. Surface plasmon resonance (SPR) measurement was performed to verify the interaction among the SAM, deoxynivalenol-antibody, and deoxynivalenol.
Demonstration of Three-Dimensional DNA Trapping Using Electric Force and Hydrodrag Force
Authors: Ukita Yoshiaki , Mouez Lassoued , Tomizawa Yuichi , Takamura Yuzuru
Published: June 2011

This paper describes the first demonstration of DNA trapping in a stacked three-dimensional (3D) microchannel. To carry out the 3D trapping of DNA by using electric force and hydrodrag force, a 3D microchip with a stacked structure is fabricated by the conventional rapid prototyping process and SU-8 peel-off process. Experimental results show that DNA trapping is observed on the application of electric potential with continuous pumping of DNA, but it is not observed in the absence of an electric potential. Further, the results suggest that the trapping throughput of DNA clearly depends on the capillary diameter but not on the flow rate. Thus, we conclude that, for a constant trapping area, reduction in the size of capillary structures with a high density results in an increase in the efficiency of DNA trapping.