• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 추계학술발표대회
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• pp.31.1-31.1
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• 2009

In an approach to acclimate ourselves torecent ecological consciousness trend, a lead-free piezoelectric material, bismuth sodium titanate (abbreviated as BNT) based bismuth sodium barium titanate (abbreviated as BNT-BT), was considered as an environment-friendly alternative for a lead based piezoelectric system. Ceramic specimens of0.94[(BixNa0.5)TiO3]-0.06[BaTiO3] (x = 0.500~0.515) compositions were prepared by a modified mixed oxide method. To increase the chemical homogeneity andre action activity, high energy mechanical milling machine and pre-milled nanosized powder has been used. In this method (BixNa0.5)TiO3 (x=0.500~0.515) andBaTiO3 were prepared separately from pre-milled constituent materials at low calcination temperature and then separately prepared BNTX (X=1, 2, 3 and 4) and BT were mixed by high energy mechanical milling machine. Without further calcination step the mixed powders were pressed into disk shape and sintered at $1110^{\circ}C$. Microstructures, phase structures and electrical properties of the ceramic specimens were systematically investigated. Highly dense ceramic specimens with homogenous grains were prepared in spite of relatively low sintering temperature. Phase structures were not significantly influenced by the excess amount Bi. Large variation on the piezoelectric and dielectric properties was detected at relative high excess Bi amounts. When $x{\leq}0.505$, the specimens exhibit insignificant variation in piezoelectric and dielectric constant though depolarization temperature is found to be decreased. Considerable amount of decrease in piezoelectric and dielectric properties are observed with higher excess of Bi amounts ($x{\geq}0.505$). This research indicates the advantages of high energy mechanical milling and importance of proper maintenance of Bi stoichiometry.

• 한국초지조사료학회지
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• 제37권1호
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• pp.50-55
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• 2017

In attempt to avoid crop damage through wild bird's picking, this study was designed with aim to evaluate several pre-sowing soybean seed coatings for optimum yield in corn-soybean mixed forage. It was investigated under four cropping treatments, viz. 1) corn sole, 2) corn mixed with soybean without any coating, 3) corn with iron coated soybean and 4) corn with thiram coated soybean. Each treatment had three replicates and corn sole was control treatment. Pioneer (P1184) and crossbred ($PI483463{\times}Hutcheson$) seeds were used for corn and soybean, respectively. The trial was conducted under randomized block design from $5^{th}$ June to $23^{rd}$ September, 2015. Data were an alyzed through ANOVA technique using SAS9.1.3 software. Results depicted that survivability of soybean against wild birds damage was found better (p<0.05) in thiram coating which was higher than iron coating and control treatment but later on thiram coating had adverse effects on subsequent growth of soybean plants. Corn stalk height was decreased (p<0.05) in thiram coating, whereas corn ear height was reduced in iron coating treatment. Iron coating enhanced (p<0.05) height of soybean plant (p<0.05) better than that of thiram coating. Soybean seed coatings didn't influence dry matter yield and nutritive value in terms of total digestible nutrients yield in corn soybean mixed forage. Conclusively, although presowing thiram coating enhanced survivability of soybean plants against wild bird damage but had adverse effects on its subsequent growth. However, soybean seed coatings didn't influence yield and nutritive value of corn soybean intercropping forage.

• 한국가스학회지
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• 제17권4호
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• pp.51-57
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• 2013

천연가스 액화 공정은 상온의 천연가스를 상압 $-160^{\circ}C$ 이하로 냉각해서 액화시키는 공정으로, 안정된 LNG 생산을 위해서는 최적의 제어 전략이 필요하다. 제어 전략을 수립할 때 가장 중요한 작업 중 하나가 공정의 분석인데, 조절 변수의 변화에 따른 제어 변수의 변화를 파악하는 것이다. 본 논문에서는 C3MR(Propane Pre-cooled Mixed Refrigerant) 공정으로 BSU(Bench Scale Unit)를 제작하여 천연가스 액화 공정을 실험하였다. 각 조절변수의 조작에 따른 유량의 변화가 공정에 미치는 영향을 알아보기 위해서 냉매의 유량변화에 따른 냉매 온도 변화 및 천연가스의 온도 변화를 분석하였고, 천연가스 자체의 유량 변화에 따른 냉매의 온도 변화를 분석함으로써 3개의 조절 변수와 공정의 제어변수들과의 관계를 알아보았다. 각 제어변수들은 독립적인 요소들이 아닌 서로 연관되어 유기적인 움직임을 보였으나, 특정 조절 변수의 변화에 따라 큰 반응을 보이는 제어 변수를 확인 할 수 있었다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.519-519
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• 2023

Estuarine dams are a recent and global phenomenon. While estuarine dams can provide the benefit of improved freshwater resources, they can also alter estuarine processes. Due to the wide range of estuarine types and estuarine dam configurations, the effect of estuarine dams on estuaries is not well understood in general. To develop a systematic understanding of the effect of estuarine dam location and freshwater discharge interval on a range of estuarine types (strongly stratified, partially mixed, periodically stratified, and well-mixed), this study used a coupled hydrodynamic-sediment dynamic numerical model (COAWST) and compared flow, sediment transport, and morphological conditions in the pre- and post-dam estuaries. For each estuarine type, scenarios with dam locations at 20, 55 and 90 km from the mouth and discharge intervals of a discharge every 0.5, 3, and 7 days were investigated. The results were analyzed in terms of change in tide, river discharge, estuarine classification, and sediment flux mechanism. The estuarine dam location primarily affected the tide-dominated estuaries, and the resonance length was an important length scale affecting the tidal currents and Stokes return flow. When the location was less than the resonance length, the tidal currents and Stokes return flow were most reduced due to the loss of tidal prism, the dead-end channel, and the shift from mixed to standing tides. The discharge interval primarily affected the river-dominated estuaries, and the tidal cycle period was an important time scale. When the interval was greater than the tidal cycle period, notable seaward discharge pulses and freshwater fronts occurred. Dams located near the mouth with large discharge interval differed the most from their pre-dam condition based on the estuarine classification. Greater discharge intervals, associated with large discharge magnitudes, resulted in scour and seaward sediment flux in the river-dominated estuaries, and the dam located near the resonance length resulted in the greatest landward tidal pumping sediment flux and deposition in the tide-dominated estuaries.

• 한국콘텐츠학회논문지
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• 제20권4호
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• pp.49-61
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• 2020

최근 공연예술에서 장르 융합형 콜라보레이션과 기술 융합형 콜라보레이션의 물리적인 융합(convergence)은 서로 다른 목표와 이질적인 속성을 전략적으로 융합시킴으로서 대중의 기대수요에 부응하며 새로운 가치의 융합 콘텐츠를 이끌어내는 실험적인 형태로 발전하고 있다. 융합시도 중 발생되는 문제점을 보완하며 공연의 완성도를 높이기 위해서는 각 매체분야 전문가들의 효율적인 협업과정이 연구되고 개선되어야 한다. 본 논문에서는 다매체 융합공연 프로토타입(Prototype) 제작을 통해 시대의 요구에 상응하는 융합공연의 효율적인 협업제작방안을 연구하고자 한다. 공연제작과정을 프리프로덕션(Pre-Production), 프로덕션(Production)으로 분류하여 라이브 연극과 사전제작 영상 애니메이션, 두 매체를 활용한 융합공연의 효율적인 협업제작과정을 작품선정 및 연출방향 설정, 인적구성, 제작일정 계획수립, 시각화과정, 공연연습 및 리허설 등의 과정으로 연구하고자 한다. 융합공연 콘텐츠 기획, 제작방식의 변화, 융합 콘텐츠 간 특수성의 이해를 바탕으로 지속적인 다매체 융합공연을 위한 효율적인 협업제작과정 연구가 진행되어야 융합 콘텐츠 산업 발전 체계화 및 활성화가 가능할 것이다.

• 펄프종이기술
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• 제43권5호
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• pp.17-26
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• 2011

Drying behavior and physical properties of HwBKP, SwBKP, and OCC handsheets depending on kneading, refining and wet pressing were analyzed. The maximum drying shrinkage velocity was newly adopted to verify the effect of mechanical treatment of pulps by evaluating drying behavior according to varying the kneading, refining and wet pressing treatments. Those various treatments were changed to evaluate the relationship between the maximum drying shrinkage velocity and handsheets properties. When the drying shrinkage and the maximum drying velocity increased by refining and wet-pressing, handsheets strength was increased. The maximum drying shrinkage velocity showed higher correlation with physical properties of paper than WRV at different refining loads at SwBKP and mixed pulp. At high wet-web dryness, drying shrinkage, the maximum drying shrinkage velocity and strength properties of handsheet were increased. It meant that drying shrinkage behavior was highly affected by not only fibers' shrinkage but also fiber bonding. Kneading pre-treatment for KOCC and SwBKP effectively modified fiber properties and increasing paper strength and drying shrinkage. The effect of kneading pre-treatment was also confirmed by the maximum drying shrinkage velocity. Strength properties of mixed pulp handsheets were not increased by the kneading pre-treatment, although the maximum drying shrinkage velocity and WRV was increased. It meant that fibers network bonding of HwBKP was limited because of ves sels and ray cells' interference for bonding. Therefore in order to improve paper strengths containing HwBKP by mechanical treatments, interference of vessels and ray cells for fiber bondings should be carefully controlled.

• Perspectives in Nursing Science
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• 제17권2호
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• pp.61-71
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• 2020

Purpose: This mixed method study aimed to investigate patients' level of anxiety and their experience of this before undergoing esophagogastroduodenoscopy (EGD). Methods: A total of 125 patients answered a questionnaire assessing their pre-EGD level of anxiety, and a total of 17 patients participated in individual interviews regarding their experience of EGD-related anxiety. The SPSS Software program was used for survey data analysis and content analysis was used for qualitative data. Results: The mean anxiety score was 40.00±9.86 and the factors related to anxiety levels were being female (p<.001) and being a relatively young age (20-30 years old, p=.004). There were no significant differences shown in level of anxiety according to the purpose EGD was performed for: screening, diagnosis, or disease follow-up. In the qualitative analysis, however, patients who underwent a follow-up procedure as a result of stomach cancer exhibited more complicated feelings of anxiety and helplessness than others. For those who underwent EGD for diagnostic reasons, they worried about the test results and were concerned about possible life changes after diagnosis. Those for whom EGD was performed for screening purposes expressed concern only in the event of EGD complications. Conclusion: This study explored the nature of pre-EGD anxiety according to the purpose of the procedure. Nurses and doctors should be aware that patients undergoing EGD may have different levels and experiences of pre-procedure anxiety.

• Journal of Dental Anesthesia and Pain Medicine
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• 제23권6호
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• pp.293-302
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• 2023

This review paper delves into the comparative study of epinephrine and phenylephrine as vasoconstrictors in dental anesthesia, exploring their histories, pharmacological properties, and clinical applications. The study involved a comprehensive literature search, focusing on articles that directly compared the two agents in terms of efficacy, safety, and prevalence in dental anesthesia. Epinephrine, with its broad receptor profile, has been a predominant choice, slightly outperforming in the context of prolonging dental anesthesia and providing superior hemostasis, which is crucial for various dental procedures. However, the stimulation of beta-adrenergic receptors caused by epinephrine poses risks, especially to patients with cardiovascular conditions. Phenylephrine, a selective alpha-1 adrenergic agonist, emerges as a safer alternative for such patients, avoiding the cardiovascular risks associated with epinephrine. Moreover, its vasoconstrictive effect may not be as deleterious as that of epinephrine, due to its selective action. This review reveals that despite the potential benefits of phenylephrine, epinephrine continues to dominate in clinical settings, due to its historical familiarity, availability, and cost-effectiveness. The lack of commercially available pre-made phenylephrine dental carpules in most countries, except Brazil, and a knowledge gap within dental academia regarding phenylephrine, contribute to its limited use. This review concludes that while both agents are effective, the choice between them should be based on individual patient conditions, availability, and the practitioner's knowledge and familiarity with the agents. The underuse of other vasoconstrictors like levonordefrin and the unavailability of phenylephrine in pre-mixed dental cartridges in many countries highlights the need for further exploration and research in this field. Furthermore, we also delve into the role of levonordefrin and examine the rationale behind the exclusion of phenylephrine from commercially available pre-mixed local anesthetic carpules, suggesting a need for a responsive approach from pharmaceutical manufacturers to the distinct needs of the dental community.

• 문화기술의 융합
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• 제9권5호
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• pp.481-486
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• 2023

본 연구에서는 간호 대학생이 가상현실을 적용하여 여성건강간호학 실습 교육과정을 적용한 후 메타인지와 비판적 사고에 미치는 교육효과를 질적, 양적으로 혼합연구 방법으로 분석하였다. 본 연구의 설계는 단일군 사전사후 검증을 사용한 양적 연구와 개별 심층 면담을 활용하여 내용 분석한 질적 연구를 활용한 수렴적 혼합연구이다. 양적 연구 결과 메타인지는 가상현실 프로그램 적용 후에 사후 104.16±12.98, 사전 98.59±18.09 (t=1.85, p=.030)로 사후 점수가 사전 점수에 비해 통계적으로 유의하게 높았다. 비판적 사고능력은 프로그램 적용 후에 사후 101.66±7.18, 사전 99.18±15.13 (t=1.00, p=.108)로 통계적으로 유의한 차이가 없었다. 그러므로 가상현실을 활용한 여성건강간호학 실습 교육은 간호대학생의 메타인지를 증진하는 데 도움을 줄 수 있어 간호학 실습 교육으로 활용할 가치가 있다.

• 한국미생물·생명공학회지
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• 제28권6호
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• pp.361-366
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• 2000

Genera and number of protozoa were investigated in the conventional activated sludge pilot plant used for the treatment of municipal sewage and pre-treated night soil-containing sewage. In both case, the predominant protozoa was ciliates and among them Vorticella was the most common. In the pilot plant where pre-treated night soil was mixed with municipal sewage, genera of free-swimming ciliates, flagellates and amoeba was higher than in those withour night soil. Correlation analysis on the quality of effluent and protozoa indicates that municipal sewage has positive correlation with protozoa. However in the pilot plan 샐 sewage contatinin pre-treated night coil soil more samples show negative correlation. Followed equations were derived by the regression analysis of BOD in both the pilot plants. In case of pilot plant A of municipal sewage, the analysis B of munici-pal and pre-treated night soil-containing sewage, the analysis of BOD was $6.731$\times$10_{-2}$ $\times$Bodo+0.306(Adjusted $R^2$=0.864). At low temperature, number of protozoa was decreased to 35% and among therm, Aspidisca was the most common genus. Therefore, protozoa can be used as indicator of quality of the effluent in sewage treatment plants.