• Title/Summary/Keyword: order-disorder

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Study of order-disorder transition in Pt-Ni bimetallic alloys

  • Seo, Ok-Gyun;Hwang, Jae-Seong;O, Pil-Geon;Gang, Hyeon-Cheol;Jeong, Hui-Su;Kim, -Chan;Kim, Dae-Gyun;Kim, Yun-Hui;Lee, Su-Ung;Kim, Gi-Ho;Jeong, Geon-Yeong;No, Do-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.403-403
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    • 2010
  • The Pt-Ni alloy is an electro-catalyst of interest in the low temperature direct methanol fuel cells(DMFCs). It has been already reported that the Pt-Ni alloy catalysts may even have enhanced activity compared to pure platinum catalyst, depending on how the surfaces are prepared. The order-disorder transition in bimetallic alloy such as $\beta$-CuZn, Cu3Au, and CuAu have been investigated greatly by x-ray diffraction. After annealing the bimetallic alloy, the crystal structure changes as observed in the order-disorder transition of Cu3Au which changes from the face centered cubic to a simple cubic structure. Pt-Ni bimetallic alloy has been already reported to have the face centered cubic structure. However, in nano-scale Pt-Ni bimetallic alloy crystals the crystal structures changes to a simple cubic structure. In this experiment, we have studied the order-disorder transition in Pt-Ni bimetallic nanocrystals. Pt/Ni thin films were deposited on sapphire(0001) substrates by e-beam evaporator and then Pt-Ni alloy were formed by RTA at 500, 600, and $700^{\circ}C$ in a vacuum environment and Pt-Ni nano particles were formed by RTA at $1059^{\circ}C$ in a vacuum environment. We measured the structure of Pt-Ni bimetallic alloy films using synchrotron x-ray diffraction and SEM.

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Order-disorder structural tailoring and its effects on the chemical stability of (Gd, Nd)2(Zr, Ce)2O7 pyrochlore ceramic for nuclear waste forms

  • Wang, Yan;Wang, Jin;Zhang, Xue;Li, Nan;Wang, Junxia;Liang, Xiaofeng
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2427-2434
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    • 2022
  • Series of unequal quantity Nd/Ce co-doped ceramic nuclear waste forms, (Gd, Nd)2(Zr, Ce)2O7, were prepared to tailor its ordered pyrochlore or disordered fluorite structure. The phase transition, microtopography, and elemental composition of the ceramic samples were systematically investigated, especially the effect of order-disorder structure on the chemical stability. It was confirmed that unequal quantity of Nd/Ce could synchronously replace the Gd/Zr-sites of Gd2Zr2O7. And the phase transition of order-disorder structure could be successfully tailored by regulating the average cationic radius ratio of (Gd, Nd)2(Zr, Ce)2O7 series. The elements of Gd, Nd, Zr, and Ce are uniformly distributed in the ordered or disordered structures. The MCC-1 leaching results showed that (Gd, Nd)2(Zr, Ce)2O7 pyrochlore ceramic nuclear waste forms had excellent chemical stability, whose elements' normalized leaching rates were as low as 10-4-10-7 g·m-2·d-1 after 7 days. In particular, the chemical stability of disordered structure was superior to that of ordered structure. It was proposed that the force constant and the closest packing were changed with the structure transformation resulting the chemical stability difference.

Factors Influencing Suicidal Ideation in People with Mental Disorder (정신장애인의 자살사고에 미치는 영향요인)

  • Seo, Seong Yee;Kim, Hee Sook;Kim, Yang Tae
    • Research in Community and Public Health Nursing
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    • v.24 no.2
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    • pp.245-254
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    • 2013
  • Purpose: This study was conducted to investigate factors influencing suicidal ideation in people with mental disorder. Methods: The subjects were 176 people with mental disorder from community mental health centers, social rehabilitation facilities, and university hospital psychiatric outpatient departments. The instruments used included a suicidal ideation questionnaire, a self-esteem scale, a spiritual well-being scale, a family support scale, and a professional support scale. Data were analyzed with t-test, one-way ANOVA, Pearson's correlation coefficient, and hierarchical regression analysis. Results: Suicidal ideation was influenced by age, history of suicidal attempts, and existential spiritual well-being. This study shows that suicidal ideation has negative correlation with existential spiritual well-being, self-esteem, family support, and age. Existential spiritual well-being, history of suicidal attempts, and age accounted for 30% regarding suicidal ideation in people with mental disorder. Conclusion: The lower existential spiritual well-being and age, the higher suicidal ideation. And also suicidal ideation was higher in people who had attempted suicide than in those who had not. Based on the outcomes of this study, it is necessary to design an intervention program that emphasizes existential spiritual well-being in order to decrease suicidal ideation in young people with mental disorder.

The Moderating Effect of Community Cohesion on the Relationship between Neighborhood Disorder and Community Integration among Persons with Mental Illnesses (동네무질서와 정신장애인의 지역사회통합과의 관계 - 지역사회응집력의 조절효과 분석 -)

  • Min, So Young
    • Korean Journal of Social Welfare
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    • v.67 no.3
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    • pp.57-82
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    • 2015
  • This study examines the extent to which community cohesion moderates the effects of neighborhood disorder on community integration among persons with mental illnesses(MI) who are living in the community. Stress process model, social disorganization theory, and neighborhood disorder model were considered with regard to the moderating effect of community cohesion. 692 persons with MI who utilized Community Mental Health Enhancement Centers were surveyed and analyzed, employing moderated regression model. Major findings showed that neighborhood disorder increased social integration. Community cohesion moderated the relationships of neighborhood disorder to three dimensions of community integration: physical, social and psychological integration. Implications for community intervention beyond the individual and service-level interventions were addressed in order to accomplish community integration for persons with MI.

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Concept, Diagnostic Criteria and a Future Prospective of Obsessive-Compulsive Disorder (강박장애의 개념과 진단기준의 변천과 향후 방향)

  • Roh, Dae-Young;Kim, Ji-Min;Kim, Chan-Hyung
    • Anxiety and mood
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    • v.6 no.2
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    • pp.93-101
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    • 2010
  • Research on obsessive-compulsive disorder (OCD) has advanced substantially since the DSM-IV was published in 1994. It is time to reexamine the nosology of this disorder, reviewing conflicting views regarding the classification as well as subtypes and specifiers of OCD. Although there is ongoing debate, OCD experts have suggested that OCD be retained in the section related to anxiety disorders and also that along with OCD, this section include obsessive-compulsive spectrum disorders (OCSD), a group of disorders closely related to OCD. A combined 'anxiety and obsessive-compulsive spectrum chapter' has also been proposed to include OCSDs. A growing body of scientific data has provided empirical support for the inclusion of a 'tic-related' subtype of OCD in the DSM-V. However, it remains controversial as to whether to introduce OCD symptom dimensions as specifiers as well as items in the diagnostic criteria. With regard to compulsive hoarding, there has been sufficient evidence to recommend that it be classified in the DSM-V as a separate disorder. Much work remains in order to ensure that the DSM-V is as evidence based as possible. It is necessary to strive toward integrating the biological and psychological data related to OCD and OCSD based on their endophenotypic features.

A Study for the Relationships between the Psychological Soundness, the Eating Attitude and the Eating Disorder among Female college students in Wonju Province (원주지역 여대생들의 이상식이습관과 식행동 및 정신건강의 관계에 관한 연구)

  • Won, Hyang-Rye
    • Journal of the Korean Society of Food Culture
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    • v.10 no.4
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    • pp.339-343
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    • 1995
  • This study was made in order to find out the relationship between the psychological soundness and the eating attitude influenced by eating disorder, and the summary of the results are as follows; 1. Almost all of the surveyed girls were in the criteria of standard weight, however they regard themselves more obese than what their actual body shape normally shows. It shows that they want a further slimmer body shape than the standard one (p=0.0000). 2. Tangable relationship was observed between such variables as her own acknowledged body type, eating attitude influenced by eating disorder and the psychological soundness. The more the girls think themselves slim the higher the score of eating attitude becomes (p=0.0000) and the lower the anxiety score becomes (p=0.0044). 3. Significant relationships was found between the obesity and the eating attitude influenced by eating disorder (p=0.0001). For the underweighted girls the high score of eating attitude influenced by eating disorder was observed, and it shows the increasing degree of eating disorder risk for them.

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The Effect of Paroxetine on Symptom Improvement and Change of Heart Rate Variability of the Patients with Panic Disorder (Paroxetine이 공황장애 환자의 증상 개선과 HRV 양상 변화에 미치는 영향)

  • Ahn, Joo-Yeun;Yu, Bum-Hee
    • Anxiety and mood
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    • v.2 no.2
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    • pp.101-107
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    • 2006
  • Object : Since autonomic nerve system dysfunction was known as the mechanism of panic disorder, many researchers used heart rate variability (HRV) as means of measuring autonomic nerve function of patients with panic disorder. We aimed to examine the effect of paroxetine medication for 3 months on symptom improvement and change of heart rate variability of the patients with panic disorder. Methods : The subjects were patients with panic disorder who visited the psychiatric outpatient clinic of Samsung Medical Center in Seoul. We included panic disorder patients who were aged from 20 to 50 and in normal BMI range (from 18 to 30) to minimize the effect of age and weight on HRV data. We excluded the patients with EKG abnormalities, hypertension or other major psychiatric disorders. They took 20-40 mg paroxetine medication a day for 3 months. Alprazolam was used only during the first month to control the acute panic symptoms and was tapered off after that. We measured the acute panic inventory (API), Hamilton rating scale for anxiety and depression (HAM-A & HAM-D), Spielberger state-trait anxiety inventory (STAIS, STAIT), and Beck depression inventory (BDI) in order to assess clinical improvement of the patients. And we measured time and frequency domain HRV in the resting, standing and cognitive stress states to assess the change of HRV. All measurements were done before and after paroxetine treatment. Result : After paroxetine medication, patients showed significant improvement in all psychiatric scales. In time domain of HRV, standard deviations of all R-R intervals (SDNN) were significantly increased in all states. In frequency domain of HRV, the ratio of high frequency to total power (HF/TP) in the standing state was significantly increased. Conclusion : After 3 months paroxetine medication, panic disorder patients showed significant clinical improvement and change in HRV data such as SDNN in all states and HF/TP ratio in the standing state. This result suggests that paroxetine medication is effective for the improvement of autonomic nerve system dysfunction in panic disorder patients.

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A Study on Relations between Deterioration of Physical Functions due to Aging and Bathroom Design Guidelines for the Elderly (노화로 인한 신체적 기능 쇠퇴와 고령자를 위한 욕실 디자인 가이드라인 관계 연구)

  • Lee, Yeun-Sook;Lim, Hyun-Jin;Lee, Ji-Hye;Ahn, Chang-Houn
    • Korean Institute of Interior Design Journal
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    • v.22 no.5
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    • pp.188-198
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    • 2013
  • Advancement toward aging society has presented the importance of house planning in consideration of the elderly, increasing the necessity of such planning. Therefore the importance of indoor design guideline for elderly houses has been stressed and the understanding of the aging in regard to this trend will create more mature spaces. In line with this trend the purpose of this study is to study the medical factors related with bathroom interior design guidelines of the existing elderly houses from the viewpoint of deteriorating physical functions due to aging process. In order to research the deterioration of physical functions due to aging literatures of medical and exercise physiology were used and concerning the existing bathroom design guidelines for the aged people, the guideline items of behavior facilitation, physiological maintenance and perceptual maintenance aspects out of Murtha & Lee's user benefit criteria(1976) related with physical functions were selected to research in relation with the knowledge about the deterioration phenomena of physical functions. Physical aging and deterioration aspects were classified from the viewpoint of musculoskeletal disorder, cardiovascular disorder, respiratory disorder, gastronomy disorder, urology disorder, somatosensory disorder, endocrine disorder, immune disorder, nervous disorder and skin diseases and these were utilized in interpreting total 100 items of bathroom design guideline. Because bathroom is the space where many physical movements are done, it had the closest relationship with the deterioration of musculoskeletal health in general and as bathroom is the space where people use water and feel the difference in temperature and moisture more than other spaces, deterioration of skin and somatosensory health had the next closest relationship. The result of this study revealed that regarding the deterioration of physical functions of the elderly people in aspect of their perceptibility as designers will design creatively and sincerely based on its relationship with nervous system in future, the result of this study will be used to develop better spatial designs efficiently to meet for the aging society.

Evolution of the Vortex Melting Line with Irradiation Induced Defects

  • Kwok, Wai-Kwong;L. M. Paulius;Christophe Marcenat;R. J. Olsson;G. Karapetrov
    • Progress in Superconductivity
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    • v.3 no.1
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    • pp.5-12
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    • 2001
  • Our experimental research focuses on manipulating pinning deflects to alter the phase diagram of vortex matter, creating new vortex phases. Vortex matter offers a unique opportunity for creating and studying these novel phase transitions through precise control of thermal, pinning and elastic energies. The vortex melting transition in untwinned YB $a_2$C $u_3$ $O_{7-}$ $\delta$/ crystals is investigated in the presence of disorder induced by particle irradiation. We focus on the low disorder regime, where a glassy state and a lattice state can be realized in the same phase diagram. We follow the evolution of the first order vortex melting transition line into a continuous transition line as disorder is increased by irradiation. The transformation is marked by an upward shift in the lower critical point on the melting line. With columnar deflects induced by heavy ion irradiation, we find a second order Bose glass transition line separating the vortex liquid from a Bose glass below the lower critical point. Furthermore, we find an upper threshold of columnar defect concentration beyond which the lower critical point and the first order melting line disappear together. With point deflect clusters induced by proton irradiation, we find evidence for a continuous thermodynamic transition below the lower critical point..

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Microbiological studies on endometritis in cattle and dairy cows (소 자궁내막염에 대한 미생물학적 분포)

  • 강신석;최필규;한성태;이용희;유정희
    • Korean Journal of Veterinary Service
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    • v.21 no.1
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    • pp.21-27
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    • 1998
  • In order to investigate reproductive disorder in dairy cows, 312 uterine from abattroirs and 56 cows from dairy farms were examined. The ovary and uterine were collected from abattroirs and rectal palpation was carried out in the case of reproductive disorder at dairy farm. Microbiological examination was also carried out from the collected samples. 1. Out of 312 ovaria from slaughter-house, cystic ovary and endometritis were classified as 51(16%) and 134(43%), respectively. And of 56 dairy cow from farms, 43(77%) were identifies as endometritis. 2. The main cause of reproductive disorder was classified as hormonal imbalances, endometritis and cystic ovary, singly or in combination. 3. The main causative agents of endometritis was encountered as E coli, Staphylococcus aureus, Bacillus sp and Corynebacterium sp. 4. The highest susceptible antibiotics to the isolates was cephalosporin.

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