• 제목/요약/키워드: reaction factors

검색결과 1,619건 처리시간 0.026초

Optimizing and Modeling Brightness Development in Peroxide Bleaching of Thermomechanical Pulp

  • Yoon, Byung-Ho;Wang, Li-Jun;Park, Soo-Kyoung;Kim, Dong-Yoon
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 1999년도 추계학술발표논문집
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    • pp.180-186
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    • 1999
  • Alkaline peroxide bleaching of (chemi) mechanical pulp is a very complicated system where various process factors affect the bleaching performance and pulp properties. Traditional on-factor-at a time method is ineffective and costly in finding the optimal bleaching conditions. In this study statistical experimental methods which include three steps. I. e. screening, response surface modeling and optimization, were used to find the conditions for maximal brightness development during one stage alkaline peroxide bleaching of TMP which had an initial brightness of 54.5% Elerpho. The TMP was pretreated with EDTA(0.5% on O. D. pulp. consistency, $30^{\circ}C$ for 60 minutes) and bleached in a 2L Mark V Quantum Reactor at 750rpm, 7.5% of bleaching consistency and with 0.05% magnesium sulfate addition. The ranges of other factors studied were 1~5% hydrogen peroxide on O. D plup, 1~4% sodium hydroxide on O. D pulp and 1~4% sodium silicate on O. D pulp, reaction temperature 50~$90^{\circ}C$ and reaction time 40~180minutes. A models with good predictability was established and the maximal brightness after one stage bleaching was found to be 70% Elerpho at $50^{\circ}C$, 50 minutes 5% hydrogen peroxide on O. D. pulp 3.2~3.4% sodium hydroxide on O. D. pulp 3.2~3.4% sodium hydroxide on O. D pulp and 4% silicate on O. D pulp. However further studies on other pulp properties such as strength and brightness stability shall be carried out in order to find out the optimal bleaching conditions.

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결핵 환자의 가족 지지와 환자 역할 행위에 관한 연구 (A Study on Support by Families of Patients with pulmonary Tuberculosis and Compliance with Sick Role Behavior)

  • 서숭미
    • 대한간호학회지
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    • 제23권4호
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    • pp.555-568
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    • 1993
  • The purposed of this study was to identify compliance with sick role behavoir and support by families of patients with pulmonary tuberculosis and to identify factors affecting these variables md factors that increase compiance with sick role behavoior This study was a survey design done in K. general hospital from 1992. 7 1 to 1992. 7. 20. The data were collected through personal interviews with 70 subjects who had pulmonary tuberculosis. A questionnaire was used to collect the data. 1. Demographic characteristics of the subjects The factor causing the tuberculosis for 28.6% of the subjects was that they lived with another family member who had pulmonary tuberculosis, 11.4% of the subjects had a family member who died of tuberculosis, 24.3% of the subjects had experienced an adverse reaction to medication. Gastroenteric disorders(28.6%) had the highest rate for this kind of adverse reaction to medication. 2. Support by families for patients with pulmonary tuberculosis The items which showed high support for compliance were taking medicine regularly(80.0% ) eat-ing a balanced diet(80.0%), loving them(84.3%), taking care of them(82.8%), getting the support from people for being sick(81.1%) The items which showed low support for compliance were meeting relatives or clergymen(20%), talking with the people suffering from pulmenary tuberculosis to relieve frustrated because they were not recovering. 3. General characteristics and family support The degree of family support showed that 75 was highest score and 30, the lowest score with 55.5(74. 1%)the average score. The degree of family support appeared similar in cases where the person was married and where the person did not have a family member with pulmonary tuberculosis(P〈.01) 4. The degree of compliance with sick role behavior by patients with pulmonary tuberculosis The degree of compliance with sick role behavior showed that 100 was the highest scoure47, the low-est score and 76.4, the average score out of a Possible score of 100. 5. Correlation between compliance with sick role behavior and family support The compliance with sick role behavior and family support showed a positive correlation(r=.2094 p〈.5) So for patients with pulmonary tuberculosis. compliance with sick role behavior is related to the sup-port given by their families.

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웹 기반 문제중심학습에 대한 학습자의 인식, 성찰수준, 학습활동에 관한 연구 - 간호학 대학원 학생을 중심으로 - (A Study on a Student's General Recognition of Web-Based PBL and Learning Activity of Students by Their Reflective Thinking Level)

  • 이선옥;박영숙
    • 한국간호교육학회지
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    • 제15권2호
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    • pp.194-204
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    • 2009
  • Purpose: Level of reflective thinking of students are important factors in the area of nursing studies on web-based PBL. These factors were used as a component of learning strategies. One was to understand general recognition to web-based PBL and reaction to the use of reflective journal. The other was to investigate the level of reflective thinking was related to learning activity. Method: PBL was adopted for an online course titled 'Nursing Assessment and Intervention'. Twenty graduate students were evaluated from questionnaire, reflective journals, and individual assignments. Result: Web-based PBL was strong for self-directed learning, team activity, creative thinking, diversity of thinking, and diverse process of learning while hard time, lack of cooperation, uncertainty of outcome, and lack of time were considered as weakness. Reflective journal gave moderate help to learning activities. The learners' learning activities was the lowest in the middle level of reflective thinking. Conclusion: Generally, graduate students in college of nursing showed slightly positive attitude to PBL experience and slightly positive reaction to the learning effect of reflective journal. PBL was estimated to be valuable and meaningful. There was no relationship between the level of reflective thinking and learning activities.

비행안전 프로그램으로서의 생체 활성도 활용방안 연구 (A Study on the Practical Use of Human Alertness for Flight Safety Program)

  • 이달호;최승호
    • 대한인간공학회지
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    • 제17권3호
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    • pp.13-22
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    • 1998
  • Aircraft and the three-dimensional environment in which they operate are not user-friendly for human beings. As a result, maintaining the proficiencies necessary to safely and efficiently fly an airplane are difficult, and costly. The physiological and emotional status of the human element remains crucial in maintaining safe performance by all crew members. In the study of Hagiwara et al.(1993). they called the physiological and emotional status of the human element into the human alertness or physiological activity and stress, fatigue, circadian rhythm, alcohol. smoking, and self-medication are known the major factors that deteriorate the human alertness. Accordingly. this paper deals with the quantitative and objective performance test based on tracking error and reaction time by means of the new computer test program into which the perception-motion system of human beings is applied. Throughout this experiment using performance test, the results suggest that performance capability in state of sleep deprivation 2 hours and alcoholic 0.05~0.06% in blood were more impaired than one in a normal state, and they further showed statistically significant differences between them, which were influenced by impairment factors of body regulation and pilot's grade. We also obtained the prediction value and the 95% confidence interval of tracking error and reaction time at the normal state for the purpose of distinguishing performance capability between the normal state and the abnormal state. And it is expected that the evaluation of human alertness using performance test will be applied to the quantitative assessment of an each pilot's realistic consciousness/attention, and will lead a flight commander to the accurate decision of mission approval prior to a flight.

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Hypersensitivity Reactions to Oxaliplatin: Clinical Features and Risk Factors in Koreans

  • Kim, Mi-Yeong;Kang, Sung-Yoon;Lee, Suh-Young;Yang, Min-Suk;Kim, Min-Hye;Song, Woo-Jung;Kim, Sae-Hoon;Kim, Yo-Jung;Lee, Keun-Wook;Cho, Sang-Heon;Min, Kyung-Up;Lee, Jong-Seok;Kim, Jee-Hyun;Chang, Yoon-Seok
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권4호
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    • pp.1209-1215
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    • 2012
  • Background and Aim: Oxaliplatin hypersensitivity is a well-known adverse reaction but the prevalence varies and data for frequency and clinical features have not been reported for Korea. Here we evaluates the prevalence and risk factors for hypersensitivity reactions to oxaliplatin after chemotherapy. Methods: Clinical information on all patients treated with oxaliplatin was retrospectively reviewed in electronic medical records between August 2009 and July 2010 in Seoul National University Bundang Hospital. Patients who experienced hypersensitivity reactions to oxaliplatin were compared with those who did not. Results: A total of 393 patients received oxaliplatin, with 42 (10.7%) experiencing hypersensitivity reactions including three cases of anaphylaxis. Median cycle of the first hypersensitivity reaction was 8. Reactions correlated with lower dexamethasone doses. Other variables were not significant. Conclusions: The prevalence of hypersensitivity reactions was 10.7%, symptoms being mostly mild and cutaneous. Lower dexamethasone doses could be a predictor for hypersensitivity reactions to oxaliplatin.

21세기 디지털 패션에 나타난 인터랙션 - 발광형 디지털 패션디자인을 중심으로 - (The Interaction Expressed in 21st Century's Digital Fashion - Focused on the Luminescence digital fashion designs -)

  • 허승연;이연희
    • 복식
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    • 제63권4호
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    • pp.17-29
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    • 2013
  • The purpose of this study is to analyze the factors of action and reaction through the examples of luminescence digital fashion design, which is a part of the interactive digital paradigm in 21st century, and to classify types of interaction expressed in luminescence digital fashion design. The significance of this study is to provide an effective database for researches on new ideas and expression methods of fashion design using luminescence digital device. The contents are as follows. First, identifying the concepts of interaction, digital fashion, and luminescence digital device. Second, analyzing the factors that put the luminescence digital device into effect through materials such as the collected photos and the stimulus behind the materials. Third, analyzing and classifying types of reaction according to the types of stimulus in luminescence digital fashion design. Detailed use of luminescence digital devices in Fashion designs did not start until after 2000 so the scope of this study starts from 2000 and on. The methods of this study are as follows. The theoretical frameworks of digital fashion and interaction were setup by using information from various related books, papers, and internet sites. In addition, the empirical analysis was performed using collected photos and explanations through related Internet sites of digital fashion. Through the study, the interaction types in 21st century's luminescence digital fashion design can be expressed variously according to the current input type, biometric recognition type, environment recognition type.

Chitosan으로부터 균일 산 촉매를 이용한 Ethyl Levulinate의 합성 (Synthesis of Ethyl levulinate from Chitosan Using Homogeneous Acid Catalyst)

  • 정귀택;김성구
    • Korean Chemical Engineering Research
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    • 제58권2호
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    • pp.266-272
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    • 2020
  • 본 연구에서는 갑각류의 껍질로부터 추출한 chitosan으로부터 황산을 촉매로 사용하여 가수분해 및 에스테르화 반응과 반응표면분석 실험계획법을 적용하여 화학 원료 및 연료로 사용 가능한 ethyl levulinate의 생산 가능성을 조사하였다. 반응물 중 수분함량의 영향을 조사한 결과, chitosan의 가수분해와 동시에 탈수반응과 ethyl levulinate로의 에스테르화와 반응은 5% 수분함량에서 가장 높았다. 반응표면분석 실험계획법을 이용하여 반응인자를 최적화한 결과, 200 ℃, 3.19% chitosan, 0.49M 황산 촉매, 5% 수분함량(95% 에탄올 용매), 그리고 58분의 반응조건에서 30.1%의 ethyl levulinate의 생성 수율을 얻었다. 또한, ethyl levulinate의 생성 수율은 반응의 가혹도가 증가할수록 증가하는 경향을 나타내었다. 이러한 결과는 chitosan이 화학 원료 및 연료의 생산에 사용될 수 있는 바이오매스로서의 잠재력이 있다고 판단된다.

침전법으로 TiCl4 수용액의 산농도 조절을 통한 나노크기의 순수한 브루카이트상 이산화티타늄 분말 제조 (Synthesis of Pure Brookite-type TiO2 Nanoparticles from Aqueous TiCl4 Solution with controlled Acidity by Precipitation Method)

  • 이정훈;양영석
    • 공업화학
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    • 제18권6호
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    • pp.545-551
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    • 2007
  • $TiCl_4$ 수용액의 침전반응으로 $TiO_2$를 제조할 때 침전용액의 염산농도와 반응온도 및 $Ti^{4+}$농도는 $TiO_2$ 침전물의 결정구조를 결정하는 중요한 인자이며, 이들의 조절을 통하여 브루카이트상의 부피분율 제어가 가능하다. 순수한 브루카이트상 이산화티타늄을 제조하기 위해서는 $Ti^{4+}$농도를 1.0 M 이하로 유지하고, 침전용액의 염산농도를 2.53~6.41 M이 되도록 조절한후 $70^{\circ}C$ 이하에서 20 h 침전반응 시켜야 한다. 한편, 순수한 브루카이트상 분말을 열처리한 결과 브루카이트상은 열처리 온도의 증가에 따라 아나타제상으로 상전이 된 후 최종적으로 루틸상으로 상변화가 진행되었다.

티타늄 가공에서 절삭력 분석을 위한 ADL 밀링 가공특성 (ADL Milling Characteristics for the Analysis of Cutting Force of Titanium Machining)

  • 한정식;정종윤
    • 산업경영시스템학회지
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    • 제45권3호
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    • pp.104-114
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    • 2022
  • The purpose of using coolant in machining is both to increase a tool life and also to prevent product deformation and thus, stabilize the surface quality by lubricating and cooling the tool and the machining surface. However, a very small amount of cutting mist should be used because chlorine-based extreme pressure additives are used to generate environmental pollutants in the production process and cause occupational diseases of workers. In this study, medical titanium alloy (Ti-6Al-7Nb) was subjected to a processing experiment by selecting factors and levels affecting cutting power in the processing of the Aerosol Dry Lubrication (ADL) method using vegetable oil. The machining shape was a slot to sufficiently reflect the effect of the cutting depth. As for the measurement of cutting force, the trend of cutting characteristics was identified through complete factor analysis. The factors affecting the cutting force of ADL slot processing were identified using the reaction surface analysis method, and the characteristics of the cutting force according to the change in factor level were analyzed. As the cutting speed increased, the cutting force decreased and then increased again. The cutting force continued to increase as the feed speed increased. The increase in the cutting depth increased the cutting force more significantly than the increase in the cutting speed and the feed speed. Through the reaction surface analysis method, the regression equation for predicting cutting force was identified, and the optimal processing conditions were proposed. The cutting force was predicted from the secondary regression equation and compared with the experimental value.

여자 배구 선수들의 스파이크 도약 시 무릎보호대가 전방십자인대 부상위험 요인에 미치는 영향 (Effects of Knee Brace on the Anterior Cruciate Ligament Injury Risk Factors during Spike Take Off in Female Volleyball Players)

  • 양창수;임비오
    • 한국운동역학회지
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    • 제24권1호
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    • pp.27-33
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    • 2014
  • In volleyball, the most common injuries are anterior cruciate ligament (ACL) tears. For this reason, volleyball players frequently use knee brace as prophylactic and rehabilitation measures. The purpose of the study was to investigate the effects of knee brace on anterior cruciate ligament injuries risk factors during spike take off in female volleyball players. Fifteen female volleyball players were recruited and performed randomly spike take off with and without knee brace. Kinematics and ground reaction data were collected to estimate the anterior cruciate ligament injuries risk factors. The ACL risk factors are knee maximum flexion angle, thigh maximum adduction angle, thigh maximum internal rotation angle, shank maximum abduction angle, shank maximum external rotation angle, knee maximum extension moment and knee maximum abduction moment. Data were analyzed with paired samples t-test with Bonfferoni collection. Female volleyball players with knee brace had no significant results in knee maximum flexion angle, thigh maximum adduction angle, thigh maximum internal rotation angle, shank maximum abduction angle and shank maximum external rotation angle compare to without knee brace. Female volleyball players, however, with knee brace showed more reduced knee maximum extension moment and knee maximal abduction moment than without knee brace. In conclusion, Female volleyball players with knee brace reduced anterior cruciate ligament stress.