• Title/Summary/Keyword: Total Resistance

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A Study on the Effectiveness of Bulbous Bow Streamline to the Ship Resistance for Large Full Form Ship (비대선에서 구상선수 주위 유선의 방향이 선박 저항에 미치는 영향에 관한 연구)

  • S.W. Hong;K.J. Lee
    • Journal of the Society of Naval Architects of Korea
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    • v.31 no.1
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    • pp.50-62
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    • 1994
  • This paper presents the results of a comparative analysis of the model test results to investigate the effect of bulbous bow installed on a large full form ship to the ship resistance performance. Seven parameters related to the shape of bulbous bow were selected and varied systematically to inquire their effects experimentally. A total number of twenty-three ship models with different bulbous bow were manufactured, and resistance tests. flow visualization test, and wave profile measurement were carried out for each model. For the comparative analysis between the various bulb forms and their model test results, bulbous bow forms are classified into nine groups according to their form characteristics. From the analysis of the trend of the resistance components, it was verified that form resistance has dominant effect on the total resistance of a slow full form ship. The model test and its statistical analysis showed that the direction of streamlines around bulbous bow has close relationship with resistance components. especially with form resistance

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Antimicrobial Resistance Characteristics of Gram-Negative Bacteria Isolated from Inland Pollution Sources in the Drainage Basin of Iwon-myeon (Taean-gun), South Korea (태안군 이원면 육상오염원 배출수에서 분리한 그람음성균의 항생제 내성 특성)

  • Park, Bo Mi;Kim, Min Ju;Jeong, Yeon Gyeom;Park, Jin Il;Yu, Hong Sik;Oh, Eun Gyoung
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.4
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    • pp.377-387
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    • 2021
  • Fecal contamination levels of discharge water from inland pollution sources were investigated in Iwon-myeon (Taean-gun), South Korea. Gram-negative bacteria were isolated during the investigation and the antimicrobial resistance patterns of the isolates were examined to estimate their impact on the coastal environment. The ranges of total coliform and fecal coliform of 12 samples from four major inland pollution sources were 79-490,000 MPN/100 mL and 2.0-490,000 MPN/100 mL, respectively, with the highest level of fecal contamination at Station No. 3. A total of 137 strains (14 genus) were isolated, of which 86 strains (62.8%) were Enterobacteriaceae. The identified isolates were as follows: Pseudomonas spp. (35 strains), Klebsiella spp. (20 strains), Serratia spp. (20 strains), and Escherichia spp. (19 strains). The isolated Gram-negative bacteria showed the highest antimicrobial resistance to ampicillin (81.8%), followed by amoxicillin/clavulanic acid (64.2%), ceftiofur (61.3%), and cefoxitin (59.1%). Antimicrobials in which less than 10% of isolates showed antimicrobial resistance were ciprofloxacin (3.6%) and gentamicin (2.2%). Resistance to one or more antimicrobials was observed in 121 strains (88.3%) and 84 strains (61.3%) showed a tendency for multiple antimicrobial resistance.

Modelling of the Resistance Model for Anode and Cathode for Molten Carbonate Fuel Cells (용융탄산염 연료전지용 공기극과 연료극의 저항 모델링)

  • LEE, CHANG-WHAN;JUNG, JUNG-YUL
    • Transactions of the Korean hydrogen and new energy society
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    • v.29 no.3
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    • pp.267-273
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    • 2018
  • From the experiments of various temperature and gas compositions, total resistance which is composed of ohmic resistance, anode resistance, cathode resistance and Nernst loss was calculated wit simple assumption. In this work, the anode and the cathode resistance was modelled with new equation which can account for the correlation between the operating temperature and the gas composition. The proposed model can predict the resistance with maximum error of 2.57% and employed in the simulation of molten carbonate fuel cells.

Impacts of sludge retention time on membrane fouling in thermophilic MBR

  • Ince, Mahir;Topaloglu, Alikemal
    • Membrane and Water Treatment
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    • v.9 no.4
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    • pp.245-253
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    • 2018
  • The aim of this study is to investigate the membrane fouling in a thermophilic membrane bioreactor (TMBR) operated different sludge retention times (SRTs). For this purpose, TMBR was operated at four different SRTs (10, 30, 60 and 100 days). Specific cake resistance (${\alpha}$), cake resistance, gel resistance, total resistance, MFI (modified fouling index) and FDR (flux decrease ratio) were calculated for all SRTs. It was observed that flux in the membrane increases with rising SRT although the sludge concentrations in the TMBR increased. The steady state flux was found to be 31.78; 34.70; 39.60 and 43.70 LMH ($Liter/m^2/h$) for the SRTs of 10, 30, 60 and 100 days respectively. The concentrations of extracellular polymeric substance (EPS) and soluble microbial product (SMP) decreased with increasing SRT. The membrane fouling rate was higher at shorter SRT and the highest fouling rate appeared at an SRT of 10 d. Both the sludge cake layer and gel layer had contribution to the fouling resistance, but the gel layer resistance value was dominant in all SRTs.

Changes in Total Work, Blood Viscosity and Hematocrit during Maximum Strength Type and Endurance Type Resistance Exercise (최대근력 저항운동과 근지구력 저항운동시 총운동량, 혈액점도 및 적혈구용적률의 변화)

  • Jeong, Hwan-Jong;Jang, Tae-Su;Kim, Ki-Hong
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.1
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    • pp.271-279
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    • 2021
  • The purpose of this study was to investigate the effects of maximum and endurance resistance exercises on total work, blood viscosity, and erythrocyte volume ratio. The study subjects were selected as 15 men in their twenties with 12 months or more of resistance exercise experience, and the bench press 1RM was measured before the experiment, and the experiment for each condition was cross-allocated at intervals of one week, and the maximum repetition was performed in 6 sets. As a result, the total amount of exercise showed that the muscular endurance strength was higher than that of the maximum muscular strength (p<.001), and the blood viscosity and erythrocyte volume ratio were higher after exercise than before (p<.01) regardless of the total exercise amount. In summary, it was found that blood viscosity was not affected by exercise intensity and amount of exercise, and increased with one-time resistance exercise. This is clinically significant in constructing a resistance exercise program, and it is considered to be a reference material in creating an exercise program for clinical patients related to vascular disease.

A Study on Factors causing the employer's Resistance (정보시스템 사용에 대한 종업원들의 저항에 관한 연구)

  • Lee, Jae-Jin;Park, Jong-Hyuk
    • Management & Information Systems Review
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    • v.23
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    • pp.233-260
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    • 2007
  • Now a day, Information and its related system has been more important in our competitive environment. In this situation, there is also an important thing that we must take into consideration, that's the employer's resistance. Until now we have little material concerning the issue, user's resistance. Owing to that, it's a little hard to study the user's resistance against the IS. Dealing with the resistance effectively helps companies save a great deal of cost and build the information system successfully. This paper takes the Markus's theories about user's resistance. According to the theories, there are three keys theories affecting resistance. To sum this, people-oriented theory, system-oriented theory and Interaction theory. To complement the theories, this paper includes another theories related with resistance and takes total seven factors causing user's resistance. Among these seven factors, four factors have a meaningful effect on the user's resistance, that is, Self-efficacy, System Complexity, Threat of the one's status and politics and System Staff's service quality. Managers and system-related company should keep it in mind very carefully, and I hope they make the best use of the result of this study.

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Effect of Gardenia Jasminoides on Insulin Resistance Induced by Non-alcoholic Fatty Liver Disease (치자 추출물의 지방대사조절을 통한 비알콜성 지방간 유도 인슐린저항성 개선 효과)

  • Seo, Il-bok;Ahn, Sang Hyun;Jeong, Han Sol;Kim, Ki Bong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.33 no.5
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    • pp.288-294
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    • 2019
  • Gardenia jasminoides is an herbal medicine that treats obesity and dampness-phlegm. This study aimed to investigate the efficacy of Gardenia jasminoides on insulin resistance induced by Non-alcoholic fatty liver disease (NAFLD). 8-week-old C57BL/6 male mice were divided into three groups: control group (Ctrl), high-fat diet group (HFF), and high fat diet with Gardenia jasminoides extract administration group (GJT). Each 10 mice was allocated to each group (a total of 30 mice). All mice were allowed to eat fat-rich diet freely throughout the experiment. To examine the effect of Gardenia jasminoides, we observed weight changes, lipid blot distributions, PPAR-${\gamma}$, p-IkB, p-JNK in liver tissue, total cholesterol, and glucose levels in serum. Comparing of body weight measurements between 3 groups, in the GJT group, weight gain was significantly suppressed compared to the HFF group. The distribution of lipid blots and positive reaction of PPAR-${\gamma}$ were significantly lower in GJT group. The expression levels of p-$I{\kappa}B$ and p-JNK that plays critical roles in the development of insulin resistance were significantly decreased by GJ treatment. Total cholesterol and glucose levels in serum were also significantly lower in GJT group. Gardenia jasminoides has the effect of improving non - alcoholic fatty liver induced insulin resistance through the regulation of lipid metabolism.

Identification of Toxin Gene and Antibiotic Resistance of Staphylococcus Aureus Isolated from Agricultural Product Cultivation Environments (농산물 생산 환경에서 분리된 Staphylococcus aureus의 항생제 내성 및 독소 유전자 확인)

  • Park, Su-Hee;Kim, Jeong-Sook;Kim, Kyeong-Yeol;Chung, Duck-Hwa;Shim, Won-Bo
    • Journal of Environmental Health Sciences
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    • v.39 no.5
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    • pp.465-473
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    • 2013
  • Objectives: This study was undertaken to analyze Staphylococcus aureus from cultivation environments for agricultural products and to confirm antibiotic resistance and enterotoxin genes for the isolated S. aureus. Methods: A total of 648 samples were collected from apple, peach, ginseng and balloon flower farms. S. aureus was isolated from soil, agricultural water, personal hygiene elements (hands, gloves and clothes) and work utensils (boxes). Results: S. aureus was detected in a total of 25 samples and 72 strains were isolated. The resistance rate of the isolated S. aureus strains was confirmed at 33.3%, with 24 resistant strains among the total of 72. Fourteen different patterns types were found, and three pattern types (NV, OX, VA) were confirmed most frequently. As result of the detection of enterotoxin gene type, four gene types (sea: 1, sed: 4, seg: all isolated S. aureus, sei: all isolated S. aureus) were analyzed among a total of nine types. Conclusions: This study demonstrates that personal hygiene techniques should be properly managed, such as washing and sterilization before or after work, because agricultural contamination by S. aureus frequently developed through improper management.

Comparison of the Effects of Sling Exercise and Total Body Resistance Exercise on Physical Functional Performance and Postural Balance : A preliminary study

  • Han-Kyu Park;Byoung-Ha Hwang
    • Journal of The Korean Society of Integrative Medicine
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    • v.12 no.2
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    • pp.11-23
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    • 2024
  • Purpose : The purpose of this study was to investigate the effect of exercise using a suspension device (sling and total body resistance exercise; TRX) on physical functional performance and postural balance. Methods : An experimental study comparing 2 different suspension exercise was conducted on 16 healthy college students. 16 subjects were assigned to two groups. They were classified into 8 sling group and 8 TRX group. Miniplus was used to evaluate physical functional performance. In this study, isokinetic resistance mode was used to compare and analyze seven movement patterns. Biorescue was used to evaluate postural balance. The intervention exercises in this study are as follows. Standing lean forward (SLF) using a sling and TRX was performed 3 times a week for 3 weeks. The SLF was held for 10 seconds and then rested for 15 seconds, repeated a total of 10 times for 3 sets. Results : In the TRX group, significant increases were observed in physical functional performance (p<.05). Among the differences between groups, significant differences were confirmed on the front of the right arm, the back of the left arm, and the back of the right arm. In the sling group, significant increases were observed in left, right, front, and overall dynamic balance (p<.05). A significant increase in posterior dynamic balance was confirmed in the TRX group (p<.05). There was no significant difference between groups. Conclusion : Based on the results of this study, TRX was effective in improving physical functional performance, while the sling was effective in enhancing postural balance. However, confirming the effectiveness of slings and TRX in the relationship between physical functional performance and postural balance proved inadequate. Therefore, additional research should be conducted to verify the effects of suspension.

A Study on Balanced -type Oseillating Mole-Drainer(III)-Model Test for Draft Force, Torque, Power and Moment (평행식 진동탄환 암거 천공기의 연구(III)-견인력, 토크, 동력 및 모멘크에 관한 모형시험-)

  • 김용환
    • Journal of Biosystems Engineering
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    • v.1 no.1
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    • pp.1-6
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    • 1976
  • This paper is the third one of the study on balanced type oscillating mole-drainer, the first one was presented in No 9. Gyeongsang College Report and the second one in Vol. 17, No.4 of the KSAE. In the first part of this study, the characteristics of traction forces between the nonoscillating earth working equipments and oscillating ones was compared. A model of the balanced type oscillating mole-drainer, which composed of a mechanism that may reduce the machine vibration, was designed following the dimensional analysis and similitude technique. The model test was carried out to clarify the balancing mechanism of the oscillating parts and other parts of the machine. In the light of the results from the model tests, a prototype machine was made for experimental purpose. Results from the field test by a reported in the near future. In the second report, the model tests were carried out under the same soil conditions, i.e, . oscillating frequency, running velocity, and oscillating amplitude, etc. It was clear that use of balanced type oscillating model could substantially reduce the vibration of the whole system of the machine, when compared with the nonoscillating type model. In this paper(the third report), results of investigation on the traction force, power requirement, and moment. etc, is presented. Analysis of variance technique was used for analyzing the effect of the frequency, amplitude, and running velocity on the draft force, torque, power requirements, and moments. The results obtained from the model tests are as follows, 1) By practicing a balanced-type oscillating mole-drainer, it was possible to reduce the traction resistance by 55.1-61. 2 percent of traction resistance, however, was 1.75 - 1.95 times greater than the value of resistance which was induced by use of a mole-drainer with single bullet. The resistance of rear shank against soil was considered as a main causing factor of the above results. 2) As the oscillation frequency was increased, the traction resistance was decreased. Considering on the effect of oscillation the greater the amplitude, and the slower the running velocity was, the greater the reduction ratio of traction resistance was. 3) The ratio of the traction resistance of oscillating mole-drainer to that of non-oscillating one could be represented as a function of dimensionless variable (V/$Af$). The results from the tests were well agreed with the reported results from the experim ents on oscillation plow or hoe. 4) By taking a lower value of (V/$Af$), reducing the traction resistance was possible. This fact meant, however, that the efficiency of mole drain practice would be lower. 5) It was experimentally confirmed under the same condition of soil that the variable (R/$rD1^3$) could be represented as a function of a variable($V^2/gD$) when a non\ulcornerocillating mole-drainer was used. 6) When a oscillating mole-drainer was used, the variable(R/$rD_1^{3}$) could be represented as a function of two variables ($v^2/gD_1$) and (V^2/gD_1$). 7) The torque was not affected by a change of frequency. However, a relation of proportionality existed between torque and amplitude, running velocity, and ratio of bullet diameter. When a balanced type oscillating mole-drainer with two bullets was used, torque was increased by 52.8-78. 4 percent and total power requirement was also increased. 8) Total power requirement was increased linearly in accordance with the increasing frequency, 41.96 percent of total power was used for oscillating action. The magnitude of total power requirement was 1. 8-9. 4 times greater than that of a non-oscillating mechanism. In the view point of power requirement, it was not advisable to increase the frequency, amplitude, running velocity, and ratio of bullet diameter at the same time. 9) Only the positive moment occured in the rear shank. Change of the diameter of a rear bullet, could not affect the balancing against the soil resistance. It was necessary for rear bullet to have a large resistance against soil only when the rear bullet was in backward motion. 10) Within an extent of the experimental base, optimum limits for several design factors were A=0.5cm, $f$=22.5Hz, V=O. 05m/sec, and $\lambda$=1.0 By adapting these values traction resistance was reduced by 40 percent and vibration acceleration wa s reduced by 60 percent. Even though the total , power requirements for operating a balanced type oscillation mechanism was greater ~than that of non-oscillating one, using a oscillating mechanism would be more effective. Because a balanced type oscillating mechanism is used, tractive resistance will be reduced and then the lighter . tractive equipment could be used.

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