확장된 계획행동이론을 통한 무주 태권도공원 방문객의 방문의도 분석

박용수(Yong Soo Park),한진욱(Jin Wook Han),김민수(Min Soo Kim) 한국사회체육학회 2012 한국사회체육학회지 Vol.0 No.48

The purpose of this study was to predict travelers` behavioral intention to visit the Muju Taekwondo Park, based on extended Theory of Planned Behavior(TPB). Tourists` motivation was newly included in determining their behavioral intention to visit the park along with existing three components of traditional Theory of Planned Behavior(attitudes, subjective norms, and perceived behavioral control). To this end, a total of 241 Taekwondo masters was selected using a conveniently sampling method and responded to a survey questionnaire. The 206 usable questionnaires were utilized to the final data analyses. Statistical Package of PASW 15.0 was used for data analyses including descriptive analysis, exploratory factor analysis, reliability analysis, correlation analysis, and multiple regression analysis. The results of this study were as follows. Firstly, attitudes toward visiting the park had a significant impact on visiting the park Secondly, subjective norms had a significant influence on visiting the park. Thirdly, perceived behavioral control significantly affected behavioral intention to visit the park. Lastly, motivation was a significant predictor of subjects` visiting the park. Additionally, practical implications of the findings and suggestions were discussed.

대량의 각혈로 사망한 장티푸스 1예

한상우,유진홍,권순석,김성훈,박지찬,홍은정,최경성,박용완,장준희,안지원,박유경,강지영,박상미,신완식 대한감염학회 2004 감염과 화학요법 Vol.36 No.5

We experienced a 25 year-old male patient with typhoid fever complicated with massive hemoptysis. Pulmonary complication in typhoid fever is very rare and to our knowledge, there has been no report of hemoptysis as a main cause of death with this disease. We herein report a rare case of typhoid fever.

만성중이염의 골도청력변화

박선홍,노용훈,이도용,나한조,김용기,최봉남,도남용 朝鮮大學校 附設 醫學硏究所 1996 The Medical Journal of Chosun University Vol.21 No.1

We have usually experienced bone conduction impairment in chronic otitis media, but it is unclear that raised bone conduction threshold is due to the reflection of cochlear dam- age and / or Carhart effect ( an artificial elevation of bone conduction threshold due to conductive defect ) or both. The purpose of this study is to verify the influence of the artificial elevation of the bone conduction threshold in chronic otitis media and to estimate Carhart effect. A total of 336 cases of tympanoplasty with unilateral chronic otitis media without any other causes of sensorineural hearing loss was studied. The average threshold levels of the bone conduction in diseased ears ranged from 18.5dB at 4kHz to 12.1dB at 250Hz The longer duration of the disease, the larger perforation size, the more severe damage of the middle ear structure and the presence of the cholesteatoma made bone conduction threshold increased. The postoperative thresholds of bone conduction were Improved in 36 cases (40.4%) of the 89 cases that underwent operation with type I tympanoplasty technique without electrie drilling. The degree of the maximal improvement was 14.3dB at 2000Hz and the minimum was 8.8dB at 250Hz. but these result did differ from a statistically significant degree. The result suggest that the bone conduction threshold in chronic otitis media is elevated artificially by conductive defect and improved by successful reconstructive surgery.

항정신병약물 사용 중인 정신분열병 환자에서 올란자판으로의 교체 방법에 관한 연구(II) : Comparison of Safety 안전성 비교

안용민,권용실,권준수,민성호,박두병,양문정,소형석,송종호,신윤식,우행원,유범희,이홍석,정한용,한창환,김용식 大韓神經精神醫學會 2002 신경정신의학 Vol.41 No.5

연구목적: 이 다기관 공동임상연구는 사용 중인 항정신병약물을 ’직접 교체 방법’또는 ’시작-감량 교체 방법’중 한 가지 방법으로 올란자핀으로 교체한 후, 안정성 측면에서 두 교체 방법 간의 비교와 교체후의 변화를 관찰하기 위한 것이다. 방법: 국내 13개 병원의 입원 및 외래에 내원한 환자들 중 ICD-10 지단기준으로 정신분열병에 해당되며, 임상적으로 항정신병약물 교체가 필요한 환자를 대상으로 하였다. 두 가지 교체 방법 중 한 가지를 무작위로 피험자에 적용하였으며, ’직접 교체 방법’에 배정된 경우에는 사용중인 항정신병약물을 일시에 중단하고 10㎎의 올란자핀을 바로 투여하였고, ’시작-감량 교체 방법’에 배정된 경우는 10㎎의 올란자핀 투여하고 2주에 걸쳐서 기존 약물을 감량하여 중단하였다. 올란자핀 사용기간은 총 6주이며, 용량은 5∼20㎎ 범위로 제한하였다. 한정성 평가를 위해서 체중, 생명징후, 자발적인 이상반응 복, 실험실 검사 그리고 Simpson-Angus Scale(SAS), Barnes akathisia rating scale(BARS), Abnormal involuntary movement scale(AIMS). Liverpool University neuroleptic side effect rating scale(LUNSERS)등을 이용하였다. 결과: 총 103명의 정신분열병 환자를 대상으로 하였다. 사용한 올란자핀의 용량, 벤조디아제핀의 병용률, 탈락률과 탈락 사유, 자발적인 이상반응 보고, 생명징후, 실험실 검사 그리고 대부분의 부작용 척도 상에서 임상적으로 의미 있는 차이를 두 교체 방법간에 발견하지 못하였다. 다만 AIMS의 감소는 ’직접 교체 방법’군에서 보다 적었고, 항콜린제의 병용률은 ’시작-감량 교체 방법’군에서 보다 많았다. 기저 상태에서 전체 피험자의 SAS와 BARS 점수는 각각 3.5점과 1.8점이었으며 70% 이상의 피험자가 고프로락틴 혈증을 보였다. 올란자핀으로 교체한 후, SAS, BARS, AIMS 점수의 유의한 감소가 있었으며 고프로락틴 혈증을 보인 피험자 분율도 약 30%이하로 감소하였다. 그러나 교체 방법과 상관없이 올란자핀 교체 후 유의한 체중 증가가 있었다. 결론: 이 연구를 통해 교체 방법에 관계없이 비교적 안전하고 용이하게 올란자핀으로 교체 할 수 있음을 알 수 있었다. 그리고 기존 항정신병약물을 올란자핀으로 교체함으로써 일부 부작용들을 줄일 수 있음을 간접적으로 관찰할 수 있었다. 하지만 이 연구는 여러 제한점과 문제점을 지니고 있기 때문에 보다 체계적인 연구를 통해 검정이 필요하리라 생각된다. Objectives: This multicenter clinical trial involving 13 hospital sites compared the safely of switching to olanzapine between ’direct switching method’ and ’start-tapering switching method’. Method: This study included both inpatients and outpatients who fulfilled the criteria for schizophrenia as defined in the ICD-10, and were in need to be appropriate for switching antipsychotics. Subjects were randomly assigned to one of the two switching methods. For ’direct switching method’group, previous antipsychotics were abruptly discontinued and 10㎎ of olanzapine was administered, and previous antipsychotics was gradually tapered for 2 weeks. Olanzapine was used for 6 weeks and the dose was adjusted within the range of 5-20㎎. The safety of switching to olanzapine was measured with vital sings including body weight, adverse events reported spontaneously, laboratory tests, and various scales such as Simpson-Angus Scale(SAS), Barnes Akathisia Rating Scale(BARS). Abnormal Involuntary Movement Scale(AIMS), and Liverpool University Neuroleptic Side Effect Rating Scale(LUNSERS). Results: 103 patients were switched to olanzapine in this study. The comparison between two switching methods did not show any significant difference in the dosage of olanzapine used, the concomitant use of benzodiazepine, the rate and reasons of drop-out, the adverse events, vital signs, laboratory tests, and most scales for measuring side-effects. However, the decrease in AIMS scores was significantly lower in ’direct switching method’ group, and the concomitant use of anticholinergics was comparatively greater in ’start-tapering switching method’ group. At baseline, SAS and BARS scores were 3.5 and 1.8 points respectively, and more than 70% of the subjects showed hyperprolactinemia. After switching to olanzapine, SAS, BARS, and AIMS scores were significantly decreased and the proportion of the patients with hyperprolactinemia was also decreased to less than 30%. However significant weight gain after the treatment of olanzapine was observed regardless of switching method. Conclusion: This study may suggest that switching to olanzapine can be done with relatively high safety regardless of switching methods and olanzapine can significantly decrease some side-effects induced by other antipsychotics.

고관절 반 치환술의 대퇴 골절 예방을 위한 강선 고정의 효과

유정한 ( Jeong Han Yoo ),박용욱 ( Yong Wook Park ),박진수 ( Jin Soo Park ),노규철 ( Kyu Cheol Rowe ),정국진 ( Kuk Jin Chung ),김홍균 ( Hong Kyun Kim ),김형년 ( Hyong Nyun Kim ),임희준 ( Hee Joon Lim ),이철 ( Cheol Lee ),황지효 ( 대한고관절학회 2009 Hip and Pelvis Vol.21 No.2

목적: 무시멘트형 양극성 반 인공 관절 치환술에 있어서 수술 도중 발생하는 대퇴 골절 예방을 위한 예방적 강선 고정술의 효과를 분석하고자 한다. 대상 및 방법: 2004년 1월부터 2008년 8월까지 무시멘트형 양극 인공 관절 치환술을 받은 65세 이상의 환자 48명(1군)을 대상으로 하여 강선을 사용하지 않은 48명의 환자(2군)와 비교하였다. 평균 나이는 75.4세(1), 73.6세(2)이었고 평균 추시 기간은 19.1개월(1), 18.3개월(2)이었다. 수술 도중 골절 발생율 외에 수술 시간, 수술 도중 예상 출혈량, 입원 기간, 방사선학적 안정성을 측정하였고 임상적 평가를 위한 대퇴 통증과 Jensen의 기능 점수와 Parker와 Palmer의 활동 점수를 비교하였다. 결과: 1군에서는 수술 도중 골절이 발생하지 않았으며 2군에서 4예(8.3%)가 발생하였다(p=0.041). 수술 시간은 각각 172분(1), 162분(2) 예상 출혈량은 866 cc(1), 855 cc(2), 입원기간 36일(1), 35일(2)이었다. 방사선학적으로 침강은 1.59 mm(1), 1.67 mm(2)이었으며 임상적으로 대퇴 통증이 1예(1), 2예(2) 관찰되었다. 임상적으로 Jensen의 기능 점수는 평균 2점(1) 2.2점(2), Parke와 Palmer의 활동 점수는 평균 5.2점(1), 5.3점 (2)이었다. 결론: 무시멘트형 인공 관절 치환술에 있어서 예방적 강선 고정술은 골절률을 의의있게 감소시켰다. Purpose: The purpose of this study was to assess the effect of a prophylactic cable fixation for prevention of femoral fractures in cementless bipolar hemiarthoplasties. Materials and Methods: Forty-eight cementless bipolar hemiarthroplasties with prophylactic cable fixations on the femur were performed in patients>65 years of age between January 2004 and August 2008 (group 1). The control group which did not undergo prophylactic cable fixation included 48 cases (group 2). The mean age was 75.4 years (group 1) and 73.6 years (group 2). The patients were followed up for an average of 19.1 (group 1) and 18.3 months (group 2). The intra-operative fracture rates were compared. Additionally, operative time, estimated blood loss (EBL), and length of hospital stay were compared. Radiologic assessment for stem stability was performed. Clinical assessment was evaluated by the thigh pain and Jensen`s functional score, and Parker & Palmer`s mobility score. Results: There was no fractures in the cabled group (1), and 4 fractures (8.3%) in the control group (2; p=0.041). The mean operative time was 172 minutes (1) and 162 minutes (2), the EBL was 866 cc (1) and 855 cc (2), and the duration of admission was 36 (1) and 35 days (2), respectively. Radiologically, subsidence was 1.59 mm (1) and 1.67 mm (2). Clinically, one (1) and two (2) thigh pains were recorded and the functional score of Jensen was 2 (1) and 2.2 points (2), and the mobility score of Parker and Palmer was 5.2 (1) and 5.3 points (2), respectively. Conclusion: Prophylactic cable fixation is effective for reducing intra-operative femoral fractures.

경주지역 여고생의 초경과 체성장간의 관계

김준섭,권오구,박진석,오종수,박정현,박제식,안세한,이용환,서정호,신태섭,최영배,김덕수,이관,박수경 東國大學校醫學硏究所 2002 東國醫學 Vol.9 No.1

본 연구는 경주지역 1개 고등학교 3학년 여고생을 대상으로 초경 시작 전인 초등학교 4학년부터 고등학교 2학년까지의 키, 몸무게, 가슴둘레 수치와 초경 연령을 파악하여 여성의 초경이 빠를수록 체성장 속도의 변화가 있을 것이라는 가설을 기초로 두 요인간의 관련성을 파악하고자 시행되었다. 경주시 1개 여자고등학교 3학년생 총 317명에 대해 ㅊ경 나이, 초경시 심리 상태, 초경이 시작되었을 때의 상담 여부와 상담하였던 사람, 부모 신장과 초경전후의 식사 규칙성, 다이어트 경험, 수면시간, 스트레스, 음주/흡연 여부, 질병력 등에 대한 설문 조사를 시행하였고, 초등학교 4학년부터 고등학교 2학년까지의 키, 몸무게, 가슴둘레에 대한 정보는 건강기록부에서 확보하였다. 상기 대상자 중 건강기록부가 분실된 39명, 초경나이에 대해 응답하지 않았던 29명 및 결석 등으로 조사를 하지 못하였던 42명을 제외한 조사 대상자는 206명으로 선정하였다. 대상자들의 초경연령 평균값(Mean±SD)은 13.0±1.11이었고, 초등학교 4학년부터 고등학교 2학년까지의 초경 이후 신장 성장률은 감소하였으며, 초경연령이 빠른 군이 초등학교 때는 신장에 있어서 우위를 차지하나 고등학교에 오면서 신장은 비슷한 수준이 되었다. 초경후 1-2년 사이에 체중과 흉위의 증가율은 감소하였고, 초경연령이 빠른 군이 초등학교와 고등학교 사이에 체중과 흉위에서 모두 우위를 차지하였다. 본 연구의 결과는, 흔히 이차 성징의 시작 시점 혹은 사춘기의 시작 시점으로 보고있는 초경 연령이 청소년기의 성장과 밀접한 관련성이 있고, 특히 체중과 흉위의 성장 속도와 밀접한 관련성이 있음을 시사한다. To understand the onset of menarche in relation to changes in physical growth that take place during female adolescence, especially the changes in height and weight velocity. The 207 senior in one women high school of Kyongju were investigated in April 3 to 8, 2001. We collected the information, relation in the age at menarche, height & weight of parents, regularity of eating, and obesity diet, duration of sleeping, sickness & stress near age at menarche, by self-recording. The status of height, weight & chest circumference between the 4th grade of primary school and the junior of high school was collected by individual Health Record. The results were followed; The average age at menarche was 12.95±1.11 years old and the most frequent age of menarche is 13 years. After menarche, the velocity of height, weight and chest circumference were decreased. The most rapid group of menarche hold dominant position in height during elementary school. As time passed, they dont hold dominant position in height. The most rapid group of menarche get an advantage in the weight and the girth of chest after elementary school. The height of subjects is directly proportional to the height of their parents. These results suggest that the starting age at menestuation can be closely associated with physical growth and development.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

류마티스 관절염에 대한 한약의 면역학적 연구동향

최도영,이재동,백용현,이송실,유명철,한정수,양형인,박상도,유미현,박은경,박동석,Choi, Do-young,Lee, Jae-dong,Back, Yong-hyeon,Lee, Song-shil,Yoo, Myung-chul,Han, Chung-soo,Yang, Hyung-in,Park, Sang-do,Ryu, Mi-hyun,Park, Eun-kyung,Park, 대한침구의학회 2004 대한침구의학회지 Vol.21 No.4

Objective : Rheumatoid arthritis is an autoimmune disease that pathogenesis is not fully understood and one of the most intractable musculoskeletal diseases. The concern in the immunopathogenesis of rheumatoid arthritis has been increased since 1980's and many immunotherapeutic agents including disease-modifying antirheumatic drugs (DMARDs) were developed and became the mainstay of treatment of rheumatoid arthritis. However, the cure of the disease has hardly been achieved. In oriental medicine, rheumatoid arthritis is related to Bi-Zheng(痺證), that presents pain, swelling, andlor loss of joint function as major clinical manifestations, and also known to be deeply involved in suppression of immune function related to weakness of Jung-Ki(正氣). The herbal medicine, empirically used, could be a potential resource of development of new immunotherapeutic agents for rheumatoid arthritis. Methods : We developed a search strategy using terms to include "rheumatoid arthritis and herbal medicine" combined with "Chinese medicine" and/or "Oriental medicine". The search was focused on experimental studies of herbal medicine (January 1999 to May 2004), which is known to have effects on immune function of patients with rheumatoid arthritis. Computerized search used Internet databases including KISS and RISS4U (Korea), CNKI (China), MOMJ (Main Oriental Medicine Journal, Japan), and PubMed. The articles were selected from journals of universities or major research institutes. Results : The literature search for experimental studies on effects of herbal medicine on immunity of rheumatoid arthritis retrieved a total of 21 articles (Korea; 8, China ; 12, Japan ; 1). Of 21 articles, 10 were related to single-drug formula, 2 to drug interaction, and 9 to multi-drug formula. Single-drug formula was mainly used for aqua-acupuncture and researches on active components. Studies of drug interaction emphasized harmony of Ki-Hyul(氣血) and balance of Han-Yeul(寒熱). Multi-drug regimen was mainly found among formulas for Bo-Ki-Hyul(補氣血) and Bo-Sin(補腎). Conclusion : Studies on rheumatoid arthritis were performed both in vitro and in vivo in vitro study, LPS-stimulated splenocytes and synoviocytes were treated with herbal medicine, resulting in proliferation and activation of immune cells and suppression of cytokine activities in vivo study CIA animal model demonstrated that herbal medicine decreased antibody production and improved function of immune cells. In cellular and molecular study herbal medicine showed profound effects on the level of mRNA expression of certain cytokines related to immune function. This study revealed that herbal medicine has significant immune modulatory action and could be used for recovery of immune dysfunction of rheumatoid arthritis patients.

光 强度別 아주까리의 光合成速度와 氣孔傳導度의 變化 및 相互聯關性

韓英熙,崔仁洙,朴賢哲,金成萬,金容澈,李忠烈 밀양대학교 농업기술개발연구소 2000 農業技術開發硏究所報 Vol.4 No.1

The Ricinus communis L. was planted 70cm x 70cm in field to investigate on the changes of photosynthesis followed by the investigation on the light intensity. The photosynthetic rate and stomatal conductance were increased as the PAR was increased to 2000μ mol/m2/s in leaves of all. A linear equation were obtained between net photosynthetic and transpiration rate. The quadratic equations were obtained between net photosynthetic rate and stomatal conductance, and a linear equation was obtained between transpiration rate and stomatal conductance. It was also confimed that intercellular CO2 concentration was significantly correlated with net-photosynthetic rate and stomatal conductance under low light intensity.

DAF에서 압력에 따른 미세기포의 크기특성

한무영,박용효,이준,심재수 대한상하수도학회 2002 상하수도학회지 Vol.16 No.2

Although DAF (Dissolved Air Rotation) has been successfully accepted for water and wastewater treatment, the fundamental characteristics of the process have not been fully investigated. According to recent theoretical work on DAF, bubble size is one of the most important factors that affect the DAF efficiency. It is well known that the size of bubbles in DAF is mostly affected by applied pressure. In this study, a newly developed Particle Counter Method (PCM) is introduced and compared with image analysis and verified. Using this PCM, the size of bubbles in DAF is measured under various pressure conditions from 2-6atm. Through a set of experiments, it was found that bubble size decreases as the pressure increases up to 3.5atm. This is a critical pressure after which bubble size does not decrease. According to the experimental results, it is not only costly but also unnecessary to maintain pressure more than 3.5atm if the goal is only to generate smaller bubbles for better removal efficiency in DAF operational practice.