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Recent Progress in Air Conditioning and Refrigeration Research - A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2004 and 2005 - (공기조화, 냉동 분야의 최근 연구 동향 -2004년 및 2005년 학회지 논문에 대한 종합적 고찰-)

  • Choi, Yong-Don;Kang, Yong-Tae;Kim, Nae-Hyun;Kim, Man-Hoe;Park, Kyoung-Kuhn;Park, Byung-Yoon;Park, Jin-Chul;Hong, Hi-Ki
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.19 no.1
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    • pp.94-131
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    • 2007
  • A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2004 and 2005 has been done. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD and flow visualization(PIV, PTV and LDV methods) technologies were widely applied for developing facilities and their systems. (2) The research trends of the previous two yews are surveyed as groups of natural convection, forced convection, electronic cooling, heat transfer enhancement, frosting and defrosting, thermal properties, etc. New research topics introduced include natural convection heat transfer enhancement using nanofluid, supercritical cooling performance or oil miscibility of $CO_2$, enthalpy heat exchanger for heat recovery, heat transfer enhancement in a plate heat exchanger using fluid resonance. (3) The literature for the last two years($2004{\sim}2005$) is reviewed in the areas of heat pump, ice and water storage, cycle analysis and reused energy including geothermal, solar and unused energy). The research on cycle analysis and experiments for $CO_2$ was extensively carried out to replace the Ozone depleting and global warming refrigerants such as HFC and HCFC refrigerants. From the year of 2005, the Gas Engine Heat Pump(GHP) has been paid attention from the viewpoint of the gas cooling application. The heat pipe was focused on the performance improvement by the parametric analysis and the heat recovery applications. The storage systems were studied on the performance enhancement of the storage tank and cost analysis for heating and cooling applications. In the area of unused energy, the hybrid systems were extensively introduced and the life cycle cost analysis(LCCA) for the unused energy systems was also intensively carried out. (4) Recent studies of various refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and of alternative refrigerants including carbon dioxide. Efficiency of various compressors and expansion devices are also dealt with for better modeling and, in particular, performance improvement. Thermoelectric module and cooling systems are analyzed theoretically and experimentally. (5) According to the review of recent studies on ventilation systems, an appropriate ventilation systems including machenical and natural are required to satisfied the level of IAQ. Also, an recent studies on air-conditioning and absorption refrigeration systems, it has mainly focused on distribution and dehumidification of indoor air to improve the performance were carried out. (6) Based on a review of recent studies on indoor environment and building service systems, it is noticed that research issues have mainly focused on optimal thermal comfort, improvement of indoor air Quality and many innovative systems such as air-barrier type perimeter-less system with UFAC, radiant floor heating and cooling system and etc. New approaches are highlighted for improving indoor environmental condition as well as minimizing energy consumption, various activities of building control and operation strategy and energy performance analysis for economic evaluation.

The City Rhinoreaction Research of the Corn Feed for the Heavy Metal Removal of the Pig Ordure Sludge Using the Citric Acid and Stability Evaluation (구연산을 이용한 돈분슬러지의 중금속 제거 및 안정성평가를 위한 사료용 옥수수의 시비반응 연구)

  • Oh, Tae-Seok;Kim, Chang-Ho;Choi, Bong-Su
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.31 no.4
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    • pp.395-408
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    • 2011
  • The study which it sees exclusions the copper and the zinc which contain in pig sludge, It study pig sludge resources fertilizer production which are rational, pig sludge resources fertilizers after seeding, silage corn it investigates growth characteristics and forage value, the result which investigates pig sludge resources fertilizers effectiveness with afterwards is same. With fertilizer ingredients in pig sludge chemical qualities, the content of the nitrogen and the phosphoric acid comes 4.4% to be 6.29%, pH 7.02 and content of the copper and the zinc which is a heavy metal which contains in pig sludge with 805 mg/kg and 1,704 mg/kg, it is a restrictive standard of the fertilizer, 300 mg/kg and 900 mg/kg it sees to be high, it manufactures citric acid 1 hydrate with the organic acid solution, heavy metals of pig sludge where it is a mixture ratio of the organic acid solution, it divides to 25%, 50%, 75% and 100% 4 kind levels, the result which measures the heavy metal exclusion ratio of the copper and the zinc, the mixture ratio of the organic acid solution to be many exclusion ratio of the copper and the zinc is showing a just interrelation, from organic acid solution 100% level content of pig sludge remains copper and zinc 330.03 mg/kg and 41.28 mg/kg, it shows the exclusion ratio of copper 59% zinc 97%. 'Cheonganok' growth characteristics with citric acid 1 hydrate, Treatment 2 and control growth characteristics etc, it exclusion the copper and the zinc it doesn't appear on significant difference statistically but, treatment 3 after only pig sludge in resources disposal where it seeding, growth characteristics of leaf area etc. is badness, it compares in control and treatment 2 the growth characteristics badness, it is appearing, it is caused by with disease and insects occurrence of $Ostrinia$ $furnacalis$ and brown spot, the damage was many. From forage value, Treatment 2 where it exclusion the heavy metal with the citric acid 1 hydrate with control it compares and there are not significant difference from crude protein and ADF and NDF contents etc., seeding only Pig Sludge in resources disposal treatment 3, it is caused by with $Ostrinia$ $furnacalis$ etc., trunk and aging of the leaf to be high ADF content is low. but from crude protein, the nitrogen ingredient which pig sludge has and interrelation it seemed and high numerical value were confirmed.

A Study on Improving Perception of Subject-Special Librarian and Subject-Special Services: Focusing on Survey Targeting Students Who Take 'Medical Terms and MeSH' and 'Health & Medical Information Sources' (주제전문사서와 주제전문서비스에 대한 인식제고를 위한 연구 - '의학용어와 MeSH', '보건의학정보원' 수강생 대상 설문조사를 중심으로 -)

  • Oh, Eui-Kyung
    • Journal of the Korean Society for Library and Information Science
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    • v.50 no.1
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    • pp.437-456
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    • 2016
  • This study, based on the need for department of LIS education program that targets training of subject-special librarian, focuses on proving that such education can improve perception of subject-special librarian and strengthen career decision-making. This study is composed of two parts. First, this study investigates case studies about subject-special librarian cultivation. Second, this study includes a survey about subject-special librarian, improving understanding about subject-special librarian, and improving career decision-making which was carried out targeting students who take 'Medical Terms and MeSH', and 'Health & Medical Information Sources' courses. Results are as follows. First, most of the respondents felt the need for medical librarian and medical information services (88.7%), understood the role of medical librarian (92.5%), got to know more about the types and functions of medical information services (100%), and came to be more aware of the self-esteem a medical librarian feels as a professional. Second, relatively, the percentage of respondents who demonstrated the willingness to work at a medical library (45.3%) or work in the field of medical information services (26.4%) was noticeably low. Third, there were no statistical difference in whether the students took related courses or not, number of courses they took and difference in their school year, and in regard of the level of understanding of medical librarian and medical information services, those who took courses demonstrated higher understanding than did those who did not take those courses. Also, those who took the courses showed stronger willingness to work as a medical librarian. Fourthly, the curriculum carried out by the department of library and information service was effective in understanding medical librarian and medical information services, but makes students more cautious about deciding whether or not to start their career at a medical library. Lastly, it was recommended that there is a need to have the curriculum updated in order to help students overcome the difficulty and unfamiliarity they feel about medical subject.

Histological studies on in vitro Propagation of Pulsatilla koreana Nakai (할미꽃 기내증식(器內增殖)에 관(關)한 조직학적(組織學的) 연구(硏究))

  • Lee, Man-Sang;Oh, Ki-Hong
    • Korean Journal of Medicinal Crop Science
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    • v.1 no.2
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    • pp.137-157
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    • 1993
  • This study was carried out to investigate the optimal condition for multiple propagation through leaf tissue culture and to apply anther culture techniques to Pulsatilla koreana Nakai breeding. Leaf and anther of Pulsatilla koreana Nakai were cultured on MS, MT, LS and $B_5$ media supplemented with several growth regulators and nitrogen sources under various conditions. For callus induction and differentiation from the Pulsatilla koreana leaf segments were more effective in the combination of zeatin and auxin than auxin alone. The color of the callus was green when treated with IBA alone. Shoot differentiation was more effective when treated with zeatin than auxin alone, especially the best hormoal combination for shoot differentiation was zeatin 1.0mg/l +NAA 0.1mg/l, while 2,4-D inhibited shoot differentiation. The appeared rate of S pollen was 35% in vivo, while that of S pollen by low temperature$(4^{\circ}C)$ pretreatment for 4 days was increased by 53% and the optimum culture time for callus induction from anther was uni-nucleate stage. $B_5$ basal medium supplemented with NAA 0.5mg/l and zeatin 1 mg/l was the most effective on callus formation and the best results of plant regeneration were obtained from combination of NAA 0.5mg/l and zeatin 0.5mg/l in anther culture. $NH_{4}NO_3$ as more effectives as the nitrogen source than $KNO_3$ and the combination with zeatin 2.0mg /L was the best effective. The best combination for plant regeneration in callus induced from anther was $NH_{4}NO_3$ 1650mg/l + $KNO_3$ 3800mg/l + zeatin 2.0mg/l. Ploidy level of anther-derived plants appeared 28% haploid, 47% diploid and the others were triploid, tetraploid and mixploid. In compare with E.S.T, M.D.H and P.X banding patterns were distinguished among callus, haploid and diploid plants in electrophoresis.

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Production of Pyruvate Dehydrogenase Complex-E2 Specific Human Monoclonal Antibody in Fed-batch Culture Systems with High Cell Density Recombinant Escherichia coli (고농도 재조합 대장균의 Fed-batch 배양 시스템을 이용한 Pyruvate Dehydrogenase Complex-E2 특이성 인간 모노클론 항체의 생산)

  • 이미숙;전주미;차상훈;정연호
    • KSBB Journal
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    • v.15 no.5
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    • pp.489-496
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    • 2000
  • Several culture systems including batch, two-stage CSTR, semi-fed batch, and two-stage cyclic fed-batch were investigated for the efficient production of the Fab fraction of PDC-E2 specific human monoclonal antibody using high cell density recombinant E. coli. A two-phase batch system and a two-stage continuous system were examined to overcome plasmid instability problems, by separating the growth and the production stages. The cell density and productivity of the two-stage continuous culture was better than that of the two-phase batch fermentation. In the two-stage continuous culture system with DO-stat, the cell growth and the productivity were superior to those of the system without the DO control. Also, almost total plasmid stability was maintained in the two-stage continuous culture system. Modified M9 medium was selected as an optimum feeding medium for the fed-batch process, and the optimum C/N ratio determined to be 2:3. The optimum feeding rate was $0.6g/\ell/hr$ for a constant feeding strategy in semi-fed batch system. When the feeding medium was fed by pulsing, it was observed that more frequent pulsing resulted in improved cell growth. The linear feeding method was the most efficient of the various feeding methods tested. Finally, high cell density culture using a two-stage cyclic fed batch system with pH-stat was tried because the linear feeding method showed limitations in terms of obtaining high cell densities, and a cell density of $54 g/\ell$ was achieved. It was concluded that the two-stage cyclic fed batch system was the most efficient system for high cell density culture of the systems tested. However, productivity improvements were lower than expected due to the extremely high accumulations of acetate, although the low levels of residual glucose were maintained.

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Effect of Calcium and Boron Intakes on Calcium Balance Status in Ovariectomized Rats (난소절제 흰쥐에 있어 칼슘과 보론 섭취수준이 칼슘 평형상태에 미치는 영향)

  • Choi, Mi-Kyeong;Kim, Mi-Hyun;Kang, Myung-Hwa
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.1
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    • pp.48-54
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    • 2006
  • This study was conducted to investigate the effect of calcium and boron intakes on calcium utilization in ovariectomized (OVX) rats. Rats were divided into 9 groups and fed diets containing various levels of calcium $(0.1\%,\;0.5\%,\;1.5\%)$ and boron (0.5 ppm, 50 ppm, 100 ppm) for 4 weeks. The half of rats in each group were ovariectomized and the others were sham-operated. Rats were fed same diets for 8 weeks after operation. Feed intake and weight gain were significantly increased as the dietary calcium was increased and those of OVX group were higher than in sham-operated group. Feed efficiency ratio was significantly higher in OVX group than that in sham-operated one. With boron supplementation, serum calcium level was significantly increased in low-calcium group, but decreased in adequate/high-calcium group. In calcium balance, calcium intake was significantly increased with increasing levels of calcium and boron and higher in OVX group than that in sham-operated one. With increasing calcium intake, fecal and urinary calcium excretions were significantly increased. Urinary calcium excretion was significantly decreased with increment of boron intake. Apparent calcium absorption of adequate-calcium OVX group was the highest among the groups. Daily calcium retention was significantly increased as the dietary calcium was increased and that of high-calcium OVX group was higher than high-calcium sham-operated group. According to these results, the boron supplementation increased the calcium intake and decreased the urinary calcium excretion. Therefore, it could be suggested that the boron supplementation may be complementary to calcium nutrition and useful for bone health.

Prevalence of Metabolic Syndrome and Related Risk Factors of Elderly Residents in Andong Rural Area 2. Based on the Biochemical Measurements and Nutrient Intakes (안동 농촌지역 중년 및 노인 주민의 대사증후군 유병율과 관련 위험요인 분석 2. 생화학 측정결과와 영양소 섭취를 중심으로)

  • Lee, Hye-Sang;Kwon, Chong-Suk
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.10
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    • pp.1459-1466
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    • 2010
  • This study was performed to identify the association between the metabolic syndrome and the biochemical measurements and nutrient intakes. A total of 1,431 people (533 males, 898 females) aged over 45 years living in Andong rural area participated in this study in 2003. Plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), $\gamma$-glutamyl transferase ($\gamma$-GT) and thiobarbituric acid reactive substances (TBARS) levels in metabolic syndrome were significantly higher than those in normal group. In multiple logistic regression, those biochemical measurements were found to be positively associated with the metabolic syndrome as the adjusted odds ratios (OR) 1.839 (p<0.001) by AST, 2.302 (p<0.01) by ALT, 2.143 (p<0.001) by $\gamma$-GT, and 1.874 (p<0.001) by TBARS. We also found that the increased level of those measurements tended to be strongly associated with high triglyceride among the metabolic syndrome components. However, the nutrient intakes between the metabolic syndrome and the normal group were not significantly different. Also, we could not find any nutrient intakes significantly associated with the metabolic syndrome, except high carbohydrate intake (>70% of kcal) compared to normal intake (55~70% of kcal) showed OR 0.781 (p<0.05). In analyzing the association of nutrient intakes with metabolic syndrome components, we found that the calorie intake was negatively associated with abdominal obesity (OR 0.696, p<0.05) and high fat intake (>25% of kcal) was positively associated with low HDL-cholesterol (OR 1.864, p<0.05). This study revealed that the biochemical measurements, such as plasma AST, ALT, $\gamma$-GT, and TBARS, are associated with metabolic syndrome, but considering the nutrient intakes, we suggest that further studies are needed to identify the associations.

An Analysis of Middle school Technology Teachers' Stage of Concerns about Maker Education By Concerns-Based Adoption Model (관심기반수용모형(CBAM)에 의한 중학교 기술교사의 메이커 교육 관심도 분석)

  • Kang, Sang-Hyun;Kim, Jinsoo
    • 대한공업교육학회지
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    • v.44 no.2
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    • pp.104-122
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    • 2019
  • In the era of the fourth industrial revolution, maker education is drawing attention as a method of student-led education. At a time when interest in maker education is also growing in technology education, figuring out what stage of concern(SoC) a middle school technology teacher is critical to effective implementation. This study analyzed SoC in maker education by layer sampling among 400 middle school technology teachers using Concerns-based adoption model. SoC was then obtained by measuring the origin using the SoCQ and then presenting it as a SOCQ profile. Gender, training experience with two lower variables were analyzed using t verification, working cities, teaching experience with more than three lower variables were analyzed using one-way ANOVA. Studies showed that SoC in maker education of middle school technology teachers showed the most similar characteristics to that of non-users. The difference in concern depending on gender was that male teachers were more concerned in maker education than female teachers. The difference in concern depending on the working city was that teachers working in the township were more concerned in the maker education than teachers working in the large city, and the difference in concern depending on the teaching career was higher among teachers with middle experience than those with low and high experience. There was also a higher stage of concern in maker education than in teachers without training experience. Therefore, it is necessary to provide middle school technology teachers with an introduction to the maker education and various information, teaching, learning and evaluation data to enhance overall concern and to support the use and evaluation of the maker education in the classroom by providing various teacher training and consulting on the maker education in the future. Further, through further study, we should conduct study that analyzes both Stage of Concern, Level of Use and Innovation Configuration, to put in the effort for effective settlement of maker education.

The knowledge and human resources distribution system for university-industry cooperation (대학에서 창출하는 지적/인적자원에 대한 기업연계 플랫폼: 인문사회계열을 중심으로)

  • Park, Yoon-Joo
    • Journal of Intelligence and Information Systems
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    • v.20 no.3
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    • pp.133-149
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    • 2014
  • One of the main purposes of universities is to create new intellectual resources that will increase social values. These intellectual resources include academic research papers, lecture notes, patents, and creative ideas produced by both professors and students. However, intellectual resources in universities are often not distributed to the actual users or companies; and moreover, they are not even systematically being managed inside of the universities. Therefore, it is almost impossible for companies to access the knowledge created by university students and professors to utilize them. Thus, the current level of knowledge sharing between universities and industries are very low. This causes a great extravagant with high-quality intellectual and human resources, and it leads to quite an amount of social loss in the modern society. In the 21st century, the creative ideas are the key growth powers for many industries. Many of the globally leading companies such as Fedex, Dell, and Facebook have established their business models based on the innovative ideas created by university students in undergraduate courses. This indicates that the unconventional ideas from young generations can create new growth power for companies and immensely increase social values. Therefore, this paper suggests of a new platform for intellectual properties distribution with university-industry cooperation. The suggested platform distributes intellectual resources of universities to industries. This platform has following characteristics. First, it distributes not only the intellectual resources, but also the human resources associated with the knowledge. Second, it diversifies the types of compensation for utilizing the intellectual properties, which are beneficial for both the university students and companies. For example, it extends the conventional monetary rewards to non-monetary rewards such as influencing on the participating internship programs or job interviews. Third, it suggests of a new knowledge map based on the relationships between key words, so that the various types of intellectual properties can be searched efficiently. In order to design the system platform, we surveyed 120 potential users to obtain the system requirements. First, 50 university students and 30 professors in humanities and social sciences departments were surveyed. We sent queries on what types of intellectual resources they produce per year, how many intellectual resources they produce, if they are willing to distribute their intellectual properties to the industries, and what types of compensations they expect in returns. Secondly, 40 entrepreneurs were surveyed, who are potential consumers of the intellectual properties of universities. We sent queries on what types of intellectual resources they want, what types of compensations they are willing to provide in returns, and what are the main factors they considered to be important when searching for the intellectual properties. The implications of this survey are as follows. First, entrepreneurs are willing to utilize intellectual properties created by both professors and students. They are more interested in creative ideas in universities rather than the academic papers or educational class materials. Second, non-monetary rewards, such as participating internship program or job interview, can be the appropriate types of compensations to replace monetary rewards. The results of the survey showed that majority of the university students were willing to provide their intellectual properties without any monetary rewards to earn the industrial networks with companies. Also, the entrepreneurs were willing to provide non-monetary compensation and hoped to have networks with university students for recruiting. Thus, the non-monetary rewards are mutually beneficial for both sides. Thirdly, classifying intellectual resources of universities based on the academic areas are inappropriate for efficient searching. Also, the various types of intellectual resources cannot be categorized into one standard. This paper suggests of a new platform for the distribution of intellectual materials and human resources, with university-industry cooperation based on these survey results. The suggested platform contains the four major components such as knowledge schema, knowledge map, system interface, and GUI (Graphic User Interface), and it presents the overall system architecture.

Changes in Circulatory and Respiratory Activities Observed on Men in an Engine Room of a Navy Ship (함정 기관실내 활동의 순환 및 호흡 기능에 대한 영향)

  • Hyun, Kwang-Chul;Nam, Kee-Yong
    • The Korean Journal of Physiology
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    • v.1 no.2
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    • pp.199-213
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    • 1967
  • Circulatory and respiratory activities were observed in men exposed to the environment of engine room of a cruising Republic of Korea Navy ship and compared to the control values obtained in an ordinary laboratory room on land. The environment of an engine room of cruising navy ship was presumed to be a multiple stress acting on men. The environment of the engine room included high temperature $(35-42^{\circ}C)$, low relative humidity (20-38% saturation), vibration (about 7 cycles per second), rolling and pitching of ship and noises. Sixteen men were divided into two groups consisted of each 8 subjects. Subjects of sea duty group had experience of continuous on board duty averaging 3.5 years. Men of land duty group had no experience of on board activity. On land observations were made on one day prior to the boarding and leaving the port and four days after landing. In between observations in the engine room were made on the first, 5 th, 9 th, 12 th, and 14 th day of on board activity. The whole experimental period lasted for 20 days. Measurements on circulatory and respiratory parameters were at standing resting state (after 30 minutes standing in the case of on land study and 15 minutes in engine room study) and within one minute after cessation of on the spot running of which rhythm was 30/min. and lasted for 5 minutes. Oxygen consumption and pulmonary function test were done in the period of two minutes from the 3rd to 5th minutes of running. The following results were obtained. 1. Body temperature showed no change regardless of group difference or on land or on board measurements. 2. Pulse rate increased markedly after boarding the ship id both groups. Pulse rate increased from the first day on board at rest and after exercise as compared to the on land control value. This increase in pulse rate was more marked after exercise. Sea duty group showed less increase in pulse rate at rest than the land duty group. Standing and resting pulse rate of sea duty group on lam was 81 and increased to 87 at the 5th day on board and remained smaller than the land duty group throughout the period on board. Control standing and resting pulse rate of land duty group on land was 76 and reached 89 at the 9th day on board and thereafter decreased a little. Pulse rate of land duty group at rest on board remained greater than that of sea duty group throughout the period on board. 3. Systolic blood pressure of sea duty group increased after boarding the ship and remained higher than the control value on land. In the land duty group, however, systolic blood pressure decreased during the period on board the ship. Diastolic blood pressure decreased in both groups. 4. Resting breathing rate of land duty group increased and remained higher than the control value on land. In sea duty group, however, resting breathing rate showed a transient increase on the 1st day on board and decreased thereafter to the control value on land and kept the same level throughout the period of cruise. Absolute value of breathing rate in the sea duty group was greater than the land duty group both at rest and after exercise. 5. There was a lowering of breathing efficiency in both groups. Thus, increases in tidal volume and minute ventilation volume and decreases in maximum breathing capacity, vital capacity, capacity ratio and air velocity Index were observed after boarding the ship. An increase in ventilation equivalent was also observed in both groups. The lowering of breathing efficiency was more marked in the land duty group than the sea duty group. 6. Energy expediture increased in both groups during their stay on the ship and was more marked in the sea duty group. 7, Lactate concentration in venous blood at rest and after exercise increased after boarding the ship and no group difference was observed.

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