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Influence of Manufacturing Conditions for the Life Time of the Boron-Doped Diamond Electrode in Wastewater Treatment (폐수처리용 붕소 도핑 다이아몬드 전극의 수명에 미치는 제조공정 변수의 영향)

  • Choi, Yong-Sun;Lee, Young-Ki;Kim, Jung-Yuel;Kim, Kyeong-Min;Lee, You-Kee
    • Korean Journal of Materials Research
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    • v.27 no.3
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    • pp.137-143
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    • 2017
  • Boron-doped diamond (BDD) electrode has an extremely wide potential window in aqueous and non-aqueous electrolytes, very low and stable background current and high resistance to surface fouling due to weak adsorption. These features endow the BDD electrode with potentially wide electrochemical applications, in such areas as wastewater treatment, electrosynthesis and electrochemical sensors. In this study, the characteristics of the BDD electrode were examined by scanning electron microscopy (SEM) and evaluated by accelerated life test. The effects of manufacturing conditions on the BDD electrode were determined and remedies for negative effects were noted in order to improve the electrode lifetime in wastewater treatment. The lifetime of the BDD electrode was influenced by manufacturing conditions, such as surface roughness, seeding method and rate of introduction of gases into the reaction chamber. The results of this study showed that BDD electrodes manufactured using sanding media of different sizes resulted in the most effective electrode lifetime when the particle size of alumina used was from $75{\sim}106{\mu}m$ (#150). Ultrasonic treatment was found to be more effective than polishing treatment in the test of seeding processes. In addition to this, BDD electrodes manufactured by introducing gases at different rates resulted in the most effective electrode lifetime when the introduced gas had a composition of hydrogen gas 94.5 vol.% carbon source gas 1.6 vol.% and boron source gas 3.9 vol.%.

Neuroprotective Effects of Ginkgo biloba extract, GBB, in the Transient Ischemic Rat Model

  • Oh, Jin-Kyung;Jung, Ji-Wook;Oh, Hye-Rim;Han, Yong-Nam;Ryu, Jong-Hoon
    • Biomolecules & Therapeutics
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    • v.15 no.3
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    • pp.169-174
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    • 2007
  • In the present study, we investigated the neuroprotective effects of standardized Ginkgo biloba extract (GBB) (total terpene trilactones, 13 ${\pm}$ 3%; biflavone, 4.5 ${\pm}$ 1.5%; flavonol glycoside, < 8%; proanthocyanidine, under detection limit) on ischemia-reperfusion-induced brain injury in the rats. Ischemia was induced by the intraluminal occlusion of the right middle cerebral artery for 2 h and reperfusion was continued for 22 h. GBB was orally administered, promptly prior to reperfusion and 2 h after. Total infarction volume in the ipsilateral hemispheres of ischemia-reperfusion rats were significantly reduced by treatment with GBB in a dose-dependent manner (P<0.05). The therapeutic time window of GBB was 3 h in this ischemia-reperfusion rat model. Furthermore, GBB also significantly inhibited increased neutrophil infiltration of ischemic brain tissue, as estimated by myeloperoxidase activity. These findings suggest that GBB plays a crucial protective role in ischemia-induced brain injury, in part, via inhibition of neutrophil infiltration, and suggest that this GBB could serve as a neuroprotective agent following transient focal ischemic brain injury.

Effects of Isothermal Stabilization Process and Ultrasonic Cleaning on the Characteristics of Rayon Fabrics (레이온직물의 특성에 미치는 등온 안정화공정 및 초음파세척의 영향)

  • Cho, Chaewook;Cho, Donghwan;Park, Jong Kyoo;Lee, Jae Yeol
    • Journal of Adhesion and Interface
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    • v.14 no.1
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    • pp.21-27
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    • 2013
  • Cellulose-based rayon fibers or fabrics can be thermally decomposed very fast within a narrow temperature window during stabilization process. Therefore the stabilization stage is critically important for producing rayon-based carbon fibers. Consequently, in the present study the effects of isothermal stabilization and ultrasonic cleaning on the weight loss, chemical composition, microstructure, and fabric texture of cellulose-based rayon fabrics were explored. The temperature of the isothermal stabilization process performed in the range of $200{\sim}240^{\circ}C$ influenced the processing time, carbon and oxygen contents, cellulose structural change, and fabric texture. The ultrasonic cleaning, which was conducted prior to the stabilization process, played a role in shortening the stabilization time, increasing the carbon contents, decreasing the oxygen contents, and changing the XRD pattern. Also, it was considered that the ultrasonic cleaning contributed to retarding the weight loss, to reducing the thermal shrinkage, and further to reducing the fast physical change of rayon fabrics.

Comparison of Wage Treatment, Employment Environment, and Job Stability before and after Conversion to Indefinite Contract Status for School Foodservice Employees in Gangwon Province (강원도 학교급식 조리종사원의 무기계약직 전환 정책에 따른 임금처우, 고용환경, 직무안정성 비교분석)

  • An, Yong-Sun;Choi, Hang-Sok;Lee, Hae-Young
    • Journal of the Korean Dietetic Association
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    • v.24 no.3
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    • pp.261-274
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    • 2018
  • The purpose of this study was to compare wage treatment and the employment environment of school foodservice employees before and after conversion to indefinite contract status since September 2012 when the Ordinance on the Appointment of Education Officials (indefinite contract) under the Gangwon Provincial Superintendent of Education was applied as well as to examine the effects of wage treatment and the employment environment on job stability. The questionnaire survey was conducted from March 31 to April 10, 2017 for school foodservice employees working at 97 schools in Gangwon province. A total of 477 questionnaires were distributed and 470 questionnaires were used for the analysis. Statistical analysis was conducted using SPSS Window Ver.18.0. The detailed results of this study were as follows. First, wage treatment (2.29 vs. 3.16), employment environment (3.45 vs. 4.22) and job stability (1.88 vs. 2.35) revealed significantly positive perceptions after conversion to indefinite contract status compared to before conversion. Second, after analyzing leading factors influencing job stability, it was revealed that wage treatment (before: ${\beta}{\hat{a}}=0.516$, P<0.05; after: ${\beta}{\hat{a}}=0.465$, P<0.05) had a positive (+) effect on job stability, whereas employment environment did not affect job stability. In conclusion, in the context that most school foodservice employees are contract employees, this study is significant in that the changes in the employment policies of the national government and education office were confirmed to have effects on school foodservice employees.

Analysis on Intake of Energy Drinks of High School Students in Gyeoungbuk Region (경북 지역 고등학생의 에너지 음료 섭취 실태 분석)

  • Lee, Su-Jin;Kim, Hyochung;Kim, Meera
    • Journal of the East Asian Society of Dietary Life
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    • v.24 no.6
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    • pp.924-932
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    • 2014
  • This study investigated intake of energy drinks, side effects and willingness to stop intake of 255 high school students in Gyeoungbuk region. The data were collected by the self-administered questionnaire. Frequency, t test, one-way ANOVA, Duncan's multiple range test, and ${\chi}^2$ test were conducted by SPSS Window V.21.0. About 78% of the respondents had experience of intake of energy drinks. The respondents were aware of energy drinks from 'advertisements on mass media (44.3%)', 'friends (32.2%)', and 'looking in stores (16.9%)'. The mean of the amount of energy drink intake per day was 30.62 mg. Forty-four percent of the respondents had energy drinks during an examination period, and 37% took it at home. The main reasons for intake of energy drinks were 'to fight off sleepiness', 'to recover from fatigue', and 'good taste' in order. Many respondents answered that energy drinks did not much help to increase concentration or learning ability. About 72% of the respondents experienced 'not feel sleepy' after having energy drinks. Half of the respondents experienced side effects such as palpitation, insomnia, and increase of urination. Most respondents had willingness to stop having energy drinks if it had bad effect on health.

Effects of the Atmosphere on the Comparative Solderability of Lead-Tin and Lead-Free Solders

  • Bin, Jeong-Uk;S.M.Adams;P.F.Stratton
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2001.04a
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    • pp.45-47
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    • 2001
  • Due to pressure from threatened legislation in Europe, consumer and governmental pressure in Japan, and glob머 market considerations in the US, there is a rapidly growing interest in lead-free solderinger, Although the move to lead free soldering seems inevitable, many problems will arise in production assembly. It is generally acknowledged that the lead-free solders available offer a much s smaller process window than lead/tin, related mainly to the higher soldering temperatures which naturally result from increases of liquidus temperatures of at least 300 C. However, raising reflow temperatures from the current 220-2300 C to 250 2600 C will lead to problems with the boards and components as well as i increasing oxidation effects. There is a need to keep reflow temperatures low without reducing solderablity. Some results on benefits of inert atmospheres are discussed in this paper. For example, testing in a nitrogen atmosphere, with 300 ppm oxygen, by the N National Physical Laboratory (NPU has revealed clear benefits for ine$\pi$mg lead-free alloys, by restoring the solderability to lead/tin levels, by enabling lower soldering temperatures. However, there has been little testing over a range of oxygen levels in nitrogen and this is an important issue in determining n nitrogen supply and oven costs. Some results are reported here from work by NPL conducted for BOC in w which solderability was evaluated for tin기ead and tin/silver/copper eutectic a alloys in a wetting balance over a range of oxygen levels form 10 ppm to 21% ( (air). The studies confirm that acceptable wetting times occur in inert atmospheres a at soldering temperatures 20 to 300 C lower than are possible in air.

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Effects on Improvement of Activities of Daily Living Through Short-Term Home Visiting Physical Therapy (단기 가정방문물리치료 시행이 일상생활동작의 개선에 미치는 효과)

  • An, Duk-Hyun
    • Physical Therapy Korea
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    • v.14 no.2
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    • pp.53-60
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    • 2007
  • The objective of this study was to discover the effects of the short-term home visiting physical therapy program involving patients with some chronic brain disorders at Gimhae City, Kyongnam. Recovery of activities of daily living (ADL) is a very important factor of rehabilitative procedures, and Functional Independence Measure (FIM) is a useful standard of evaluation for it. The FIM is widely used in brain disorder research because it measures real functional activities of daily living. We applied the physical therapy exercise program twice per week (10~15 times repeatedly); a warm-up and cool down exercise performed every ten minutes by active & active-assistive ROM and stretching exercises. Main exercises were composed of getting up & laying down in bed, standing training, walking exercise in the room, and window or wall sliding exercise using affected upper limbs for a total duration of 30 minutes. We collected the data from 20 patients with chronic brain disorders at his/her home and analyzed by means of SPSS/PC+ program (Ver. 10.0). After the six week long physical therapy exercise program, the average was $56.10{\pm}22.59$ point compared with initial $50.55{\pm}19.12$ point by FIM, improved functional ADL ability about 5.55 point, and these changed scores were statistically significant (p=.000). We also studied another factor regarding patient's satisfaction. The majority of subjects (10 people) rated the program with the maximum score of ten points (50.0%), and three people rated it a seven point program (15.0%), the other two subjects gave a rating of nine and eight points (10.0%). Because the program was effective at improving the physical ADL ability and satisfaction of each subject, we suggest continual development and implementation of a home visiting physical therapy program. Further study should involve a longer period of observation with a larger population that is involved in an individually designed home physical therapy program.

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Effects of Telephone Intervention as Supportive Nursing on Self-Care Practices and Qualify of Life for Gynecological Cancer Patients under Chemotherapy (전화를 이용한 지지간호가 항암화학요법을 받는 여성 암 환자의 자가간호수행과 삶의 질에 미치는 효과)

  • Kim, Ae-Sook;Lee, Eun-Sook;Kim, Sung-Hyo
    • Journal of Korean Academy of Nursing
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    • v.37 no.5
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    • pp.744-753
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    • 2007
  • Purpose: The effects of telephone intervention on self-care practices and quality of life for gynecological cancer patients under chemotherapy was investigated. Methods: A non-equivalent control group pre-test post-test quasi-experimental design was used. The subjects were women cancer patients who had received less than two chemotherapy sessions at C university hospital of Chonnam province(26 in the experimental group: 25 in the control group). The patient's self-care practices(Na & Lee, 1999; Jang, 2004) and quality of life(Lee & Jo, 1997) were measured three times. using a questionnaire. The data was analyzed by Repeated Measures ANOVA, the Friedman test, and the Mann-Whitney test using the SPSS window version 12.0 program. Results: This study showed that the score of self-care practices and quality of life for the experimental group under telephone counseling were higher than those of the control group. Conclusion: This study revealed that a telephone intervention as supportive nursing care for women cancer patients under going chemotherapy was effective for self-care practices and qualify of life during the recovery period. Futhermore, this study also suggests that telephone counseling can serve as a continuing nursing supportive intervention for women cancer patients for the upcoming stages of further chemotherapy.

The Effects of Satisfaction in their Departments of Health College Students and the Types for Career Decision on Career Preparatory Behavior (보건계열 대학생의 학과만족도, 진로의사결정유형이 진로준비행동에 미치는 영향)

  • Park, Daesung
    • Journal of Digital Convergence
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    • v.12 no.10
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    • pp.415-423
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    • 2014
  • This study aims to understand the difference in department satisfaction, career decision types and career preparatory behavior of health college students, and the relationship between variables and their effects on career preparatory behavior, and presents basic data for development of career guidance programs. The subjects of this study were 450 college students studying emergency rescue, physical therapy, public health administration and dental hygiene at three-year colleges located in B and G cities. They were selected through convenience sampling. The period of the study was from November 12 to 15, 2013. of 450 copies of the questionnaire distributed, a total of 418 copies were used in the final analysis. For data analysis, SPSS 14.0 for Windows was used. As a result, there were correlations between variables, the largest effect department satisfaction had on career preparatory behavior was found in aptitude learning followed by personal relationships and career job. The reasonable type of career decision types had a positive effect on career preparatory behavior while dependent and instinctive types had a negative effect on career preparatory behavior.

The Selective Oxidation of CO in Hydrogen Rich Stream over Alumina Supported Cu-Ce Catalyst (알루미나에 담지된 Cu-Ce 촉매상에서의 개질수소가스에 포함된 CO의 선택적 산화 반응에 관한 연구)

  • Park, J.W.;Jeong, J.H.;Yoon, W.R.;Lee, Y.W.
    • Journal of Hydrogen and New Energy
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    • v.14 no.2
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    • pp.155-170
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    • 2003
  • $Cu-Ce/{\gamma}-Al_2O_3$ based catalysts were prepared and tested for selective oxidation of CO in a $H_2$-rich stream(1% CO, 1% $O_2$, 60% $H_2$, $N_2$ as balance). The effects of Cu loading and weight ratio(=Cu/(Cu+Ce)) upon both activity and selectivity were investigated upon the change in temperatures, It was also examined how the activity and selectivity of catalysts were varied with the presence of $CO_2$ and $H_2O$ in the reactant feed. Among the various Cu-Ce catalysts with different catalytic metal composition, Cu-Ce(4 : 16 wf%) /${\gamma}-Al_2O_3$ catalyst showed the highest activity(>$T_{99}$) and selectivities(50-80%) under wide range of temperatures($175-220^{\circ}C$). However, in the Cu-Ce(4 : 16 wt%)/ ${\gamma}-Al_2O_3$, the presence of $CO_2$ and $H_2O$ in the reactant feed decreased the activity and the maximum activity(>$T_{99}$) in terms of reaction temperature moved by about $25^{\circ}C$ toward higher temperature, the $T_{>99}$ window was seen between $210-230^{\circ}C$ (selectivity 50-75%). From $CO_2-/H_2O-TPD$, it can be concluded that the main cause for the decrease in catalytic activity may be attributed to the blockage of the active sites by competitive adsorption of water vapor and $CO_2$ with the reactant at low temperatures.