• Title/Summary/Keyword: Physical tests

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Freeze-thaw Resistance Estimation of Concrete using Surface Roughness and Image Analysis (콘크리트의 동결융해 저항성 추정을 위한 표면 거칠기 및 이미지 분석의 적용성)

  • Lee, Binna;Lee, Jong Suk
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.3
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    • pp.1-7
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    • 2018
  • As part of a research dedicated to the field evaluation of the durability of concrete subjected to freezing-thawing, this study analyzes the relationship between the surface roughness and the relative dynamic elastic modulus through image analysis. Four mix compositions with water-to-binder ratios (W/B) of 40%, 50%, 60% and 70% and without AE agent were considered to provoke early freezing. The basic physical properties of the mixes including the relative dynamic elastic modulus and the compressive strength were first evaluated experimentally according to W/B. Then, tests were performed to measure the surface roughness followed by photographs and SEM image analysis. The measured surface roughness tended to increase with larger number of freezing-thawing cycles regardless of W/B. The relative dynamic elastic modulus appeared to increase gradually with the number of cycles for the relatively denser mixes with W/B of 40% and 50%. Besides, the surface roughness increased only at rupture for the mixes with W/B of 60% and 70%. Moreover, the analysis of the photographs of the surface of the mixes with W/B of 40% and 50% revealed that the degradation progressed gradually from the surface with the freezing-thawing cycles. However, for the mixes with W/B of 60% and 70%, apparent change of the surface remained very insignificant until rupture at which damage like cracking could be observed. Consequently, the analysis of surface photograph or the measurement of the surface roughness presented some limitation in assessing the degree of freezing-thawing-induced degradation in case of relatively porous specimens. On the other hand, the photograph and surface roughness appeared to be sufficient for assessing such degradation for the mixes with W/B of 40% and 50%. Accordingly, the image of the surface and the surface roughness are potentially applicable on site for the assessment of freezing-thawing damages in relatively dense mixes.

Changes of Heart Rate During Marathon Running (장거리 (마라톤)선수에서의 전 경기중 심박동수의 변화)

  • Kim, In-Kyo;Lee, Jung-Woo;Hah, Jong-Sik;Ryu, Yun-Hee;Choi, Jung-Ok;Kim, Ki-Ho
    • The Korean Journal of Physiology
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    • v.13 no.1_2
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    • pp.1-12
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    • 1979
  • To evaluate the present status of physical fittness of Korean long distance runners, body fat, pulmonary functions, maximal oxygen intake and oxygen debt were measured in 5 elite marathoners (A group), 6 college student runners (B group) and 3 middle school student runners (C group). After laboratory tests, full course marathon running was performed in 2 elite marathoners during which their heart rates were monitored continuously. The results are summerized as follows: 1) Total body fat in all three groups are in the range of 13-15% of their body weight. 2) In all three groups, average values of various pulmonary functions were within the normal limits, but those of tidal volume were higher and respiratory rate were lower in comparison to normal values. These phenomena may represent respiratory adaptations against training. The average resting oxygen consumptions in A,B and C were $322{\pm}23$, $278{\pm}14$ and $287{\pm}16$m1/min, respectively. 3) In all three groups, resting blood pressures were in the normal range, but the resting heart rate was slightly lower in groups A $(56{\pm}3\;beats/min)$ and B $(64{\pm}2\;beats/min)$ and higher in group C $(82{\pm}9\;beats/min)$ in comparison to normal values. These changes in cardiovascular functions in marathoners may also represent adaptive phenomena. 4) During treadmill running the minute ventilation and oxygen consumption of the runners increased lineally with work load in all three groups. When the oxygen consumption was related to heart rate, it appeared to be a exponential function of the heart rate in all three groups. 5) The average maximal heart rates during maximal work were $196{\pm}3$, $191{\pm}3$ and $196{\pm}5\;beats/min$ for groups A,B and C, respectively. Maximal oxygen intakes were $84.2{\pm}3.3\;ml/min/kg$ in group A, $65.2{\pm}1.1\;ml/min/kg$ in group B and $58.7{\pm}0.4\;ml/min/kg$ in group C. 6) In all three groups, oxygen debts and the rates of recovery of heart rate after treadmill running were lower than those of long ditsance runners reported previously. 7) The 40 km running time in 2 elite marathoners was recorded to be $2^{\circ}42'25'$, and their mean speed was 243 m/min (ranged 218 to 274 m/min). The heart rate appeared to increase lineally with running speed, and the total energy expenditure during 40 km running was approximately 1360.2 Calories. From these it can be speculated that if their heart rates were maintained at 166 beats/min during the full course of marathon running, their records would be arround $2^{\circ}15'$. Based on these results, we may suspect that a successful long distance running is, in part, dependent on the economical utilization of one's aerobic capacity.

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Effect of Air Contents, Deicing Salts, and Exposure Conditions on the Freeze-Thaw Durability of the Concrete (콘크리트의 동결융해 내구성에 공기량, 제설제, 노출조건이 미치는 영향에 관한 연구)

  • Lee, Byung-Duk
    • International Journal of Highway Engineering
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    • v.12 no.2
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    • pp.107-113
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    • 2010
  • In this study, the relative effects of low-chloride deicier(LCD) and two other deicing agents on the scaling of concrete were conducted in a series of tests at laboratory accordance with the ASTM C 672. The solutions concentration of deicers tested included 1, 4, 10%. Tap water was used as control. The amount of scaling was evaluated gravimetrically. As test result of deicer solution types, when applied to 4% solutions, surface scaling of concrete after 56 freeze-thaw cycles was produced significantly as about 9 times on LCD solution, as about 18 times on $CaCl_2$ solution, and as about 33 times on NaCl solution comparing with tap water. As test result of deicer solution concentrations, relatively low concentrations (of the 4% by weight) of deicer were produced more surface scaling than higher concentrations (of the 10% by weight) or lower concentrations (of the 1% by weight) of deicer. It show that the damaging concentration is of the order of 3~4% for previous research result. It appears that the mechanism of surface scaling is primarily physical rather than chemical. Also, the effect of chloride deicier types, freeze-thaw cycling, and air contents on the performance of concrete was experimentally investigated. The results show that the concrete specimens subjected to freeze-thaw cycling scaled more severely in exposure to deicing salt than those in non-exposure to deicing salt, weight losses of the specimens tested in exposure to deicing salt were twice as much as those tested in non-exposure to deicing salt. Relative dynamic modulus of elasticity of concrete specimens decreased more quickly in exposure to deicing salt than in non-exposure to deicing salt. Also, relative dynamic modulus of elasticity of concrete specimens in exposure to sodium chloride deicing salt was decreased more quickly comparing with exposure to LCD salt. It is also shown that the chloride contents according to concrete specimen depths was more largely in exposure to LCD salt. When concrete specimen is exposed to chloride deicing salts and freeze-thaw cycling, performance degradation in the entrained air concrete(AE concrete) retarded more considerably comparing with non-entrained air concrete(Non-AE concrete).

Evaluation of Continuing Education Program to Enhance Competency for Hospice Volunteers: An Exploratory Mixed-Methods Design (호스피스 자원봉사자 역량강화를 위한 지속교육의 효과: 혼합연구방법의 적용)

  • Seo, Minjeong;Cho, Han-A;Han, Sang Mi;Ko, Youngshim;Gil, Cho-Rong
    • Journal of Hospice and Palliative Care
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    • v.22 no.4
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    • pp.185-197
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    • 2019
  • Purpose: Hospice volunteers are serving an invisible yet pivotal role in the hospice and palliative care team. This study investigated how effectively a continuing education program could enhance hospice volunteers' competency. Methods: A total of 20 hours (four hours per week) of training was provided to 30 hospice volunteers who participated in the continuing education for hospice volunteers. Efficiency of the education was analyzed with an exploratory mixed-methods design. For quantitative analysis, the volunteers were asked, before and after the training, about their attitudes towards hospice care, what makes a meaningful life, self-efficacy and satisfaction with their volunteer service. Descriptive statistics, paired t-tests, and Wilcoxon signed-rank test were performed using SPSS Window 20.0. For qualitative research, participants were placed in three groups for a focus group interview, and data were analyzed by content analysis. Results: A quantitative study result shows that this training can significantly affect hospice volunteers' attitudes and improve their self-efficacy. A qualitative study result shows that participants wanted to receive continuous education from the physical/psychosocial/spiritual aspects to better serve end-of-life patients and their family members even though they have to spare significant time for the volunteer service. They wanted to know how to take good care of patients without getting themselves injured and how to provide spiritual care. Conclusion: The continuing education program reflecting volunteers' requests is strongly needed to improve their competency. An effective continuing education requires continuous training and support in areas where hospice volunteers are interested in. A good alternative is to combine web-based and hands-on training, thereby allowing hospice volunteers freely take training that suits their interest.

Current Wheat Quality Criteria and Inspection Systems of Major Wheat Producing Countries (밀 품질평가 현황과 검사제도)

  • 이춘기;남중현;강문석;구본철;김재철;박광근;박문웅;김용호
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47
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    • pp.63-94
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    • 2002
  • On the purpose to suggest an advanced scheme in assessing the domestic wheat quality, this paper reviewed the inspection systems of wheat in major wheat producing countries as well as the quality criteria which are being used in wheat grading and classification. Most wheat producing countries are adopting both classifications of class and grade to provide an objective evaluation and an official certification to their wheat. There are two main purposes in the wheat classification. The first objectives of classification is to match the wheat with market requirements to maximize market opportunities and returns to growers. The second is to ensure that payments to glowers aye made on the basis of the quality and condition of the grain delivered. Wheat classes has been assigned based on the combination of cultivation area, seed-coat color, kernel and varietal characteristics that are distinctive. Most reputable wheat marketers also employ a similar approach, whereby varieties of a particular type are grouped together, designed by seed coat colour, grain hardness, physical dough properties, and sometimes more precise specification such as starch quality, all of which are genetically inherited characteristics. This classification in simplistic terms is the categorization of a wheat variety into a commercial type or style of wheat that is recognizable for its end use capabilities. All varieties registered in a class are required to have a similar end-use performance that the shipment be consistent in processing quality, cargo to cargo and year to year, Grain inspectors have historically determined wheat classes according to visual kernel characteristics associated with traditional wheat varieties. As well, any new wheat variety must not conflict with the visual distinguishability rule that is used to separate wheats of different classes. Some varieties may possess characteristics of two or more classes. Therefore, knowledge of distinct varietal characteristics is necessary in making class determinations. The grading system sets maximum tolerance levels for a range of characteristics that ensure functionality and freedom from deleterious factors. Tests for the grading of wheat include such factors as plumpness, soundness, cleanliness, purity of type and general condition. Plumpness is measured by test weight. Soundness is indicated by the absence or presence of musty, sour or commercially objectionable foreign odors and by the percentage of damaged kernels that ave present in the wheat. Cleanliness is measured by determining the presence of foreign material after dockage has been removed. Purity of class is measured by classification of wheats in the test sample and by limitation for admixtures of different classes of wheat. Moisture does not influence the numerical grade. However, it is determined on all shipments and reported on the official certificate. U.S. wheat is divided into eight classes based on color, kernel Hardness and varietal characteristics. The classes are Durum, Hard Red Spring, Hard Red Winter, Soft Red Winter, Hard White, soft White, Unclassed and Mixed. Among them, Hard Red Spring wheat, Durum wheat, and Soft White wheat are further divided into three subclasses, respectively. Each class or subclass is divided into five U.S. numerical grades and U.S. Sample grade. Special grades are provided to emphasize special qualities or conditions affecting the value of wheat and are added to and made a part of the grade designation. Canadian wheat is also divided into fourteen classes based on cultivation area, color, kernel hardness and varietal characteristics. The classes have 2-5 numerical grades, a feed grade and sample grades depending on class and grading tolerance. The Canadian grading system is based mainly on visual evaluation, and it works based on the kernel visual distinguishability concept. The Australian wheat is classified based on geographical and quality differentiation. The wheat grown in Australia is predominantly white grained. There are commonly up to 20 different segregations of wheat in a given season. Each variety grown is assigned a category and a growing areas. The state governments in Australia, in cooperation with the Australian Wheat Board(AWB), issue receival standards and dockage schedules annually that list grade specifications and tolerances for Australian wheat. AWB is managing "Golden Rewards" which is designed to provide pricing accuracy and market signals for Australia's grain growers. Continuous payment scales for protein content from 6 to 16% and screenings levels from 0 to 10% based on varietal classification are presented by the Golden Rewards, and the active payment scales and prices can change with market movements.movements.

The Effects of Feeding Feed Additives Containing Microorganisms on Characteristics of Excreta in Growing Pigs (육성돈에 미생물제제 급여시 분뇨 특성에 미치는 효과 연구)

  • Kwag, J.H.;Choi, D.Y.;Park, Ch.H.;Kim, J.H.;Jeong, K.H.;Yang, Ch.B.;Yoo, Y.H.;La, C.S.
    • Journal of Animal Environmental Science
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    • v.13 no.1
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    • pp.35-44
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    • 2007
  • The effects of microbial feedstuff additives on feed conversion rate and physical and chemical characteristics of excreta in growing pigs were investigated. Three different products (A, B and C) were compared. Microbial population tests showed B contained higher numbers of total bacteria, Lactobacillus spp. and yeasts. The amylase activity of B was also higher than that of A and C. The daily feed intake rates fer control, A, B and C were 2.06, 2.13, 2.17 and 2.34 kg, respectively. Pigs feed product C had the highest liveweight gain(2.89 kg). However, the results of feed conversion rate were not significantly different between treatments. Amount of faces excreted for control, A, B and C was 1.18, 1,19, 1.23 and 1.32 kg, respectively. Urine volume for control, A, B, and C was 1.91, 1.80, 2.19 and 2.31 kg respectively. Moisture content, T-N, $P_2O_5$ and $K_2O$ in pig manure were not significantly different between treatments. The range of BOD values was 63,453 to $73,758mg/\ell$ for faeces, and 5,678 to $7,428mg/\ell$, for urine. SS values of solid and liquid excreta ranged from 142,200 to 176,000 and from 710 to $1,025mg/\ell$, respectively.

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Effect of Noise in Human Body (소음이 인체에 미치는 영향)

  • 이영노
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1972.03a
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    • pp.7-8
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    • 1972
  • The effects of noise exposure are of two types: Nonauditory effects and auditory effects. Nonauditory effects of noise exposure are interference with communication by speech, sleeping and emotional behavior. The noise will cause the high blood pressure and rapid pulse, also that decrease the salivation and gastric juice. in experimentaly showed that the Corticoid hormon: Gonatotropic hormone were decrease and Thyrotropic hormoone is increase. Auditory effect of noise exposure. when the normal ear is exposed to noise at noise at hamful intensities (above 90㏈) for sufficiently long periods of time, a temoral depression of hearing results, disappearing after minutes or hours of rest. When the exposure longer or intesity greater is reached the Permanent threshold shift called noise-induced hearing loss. Hearing loss resulting from noise exposure presents legal as well as medical problems. The otologist who examines and evaluates the industrial hearing loss cases must be properly informed, not only concerning the otologic but also about the physical and legal aspects of the problems. The measurement of hearing ability is the most important part of a hearing conservation, both preplacement and periodic follow-up tests of hearing. The ideal hearing conservation program would be able to reduce or eliminate the hazardous noise at its source or by acoustic isolation of noisy working area and two ear protections (plugs and muff type) were developed for personal protection.

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Caregivers' adherence factors affecting maintenance treatment in children with well-controlled asthma : A qualitative analysis through in-depth interview (천식 조절 상태 환아의 유지 치료에 대한 보호자 순응 요인: 심층 면담을 통한 질적 분석)

  • Choi, Ic Sun;Cho, Saeng Koo;La, Kyong Suk;Byeon, Jung Hye;Song, Dae Jin;Yoo, Young;Choung, Ji Tae
    • Clinical and Experimental Pediatrics
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    • v.53 no.3
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    • pp.364-372
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    • 2010
  • Purpose : Good adherence of caregivers is essential for successful health outcomes in the treatment of childhood asthma. The purpose of this study was to identify the factors contributing to good adherence of maintenance treatment in children with well-controlled asthma. Methods : Children with well-controlled asthma being treated with a daily controller for at least 3 months in Korea University Anam Hospital were selected. Their caregivers who had good adherence to maintenance treatment were recruited. Qualitative study through in-depth interviews was conducted with 18 caregivers who agreed to the study. Results : The 18 caregivers (mean age, 40.0 years) consisted of 15 mothers, 2 grandmothers, and 1 father. The resulting consensus were identified and grouped into 2 domains: the caregiver/patient aspect with 8 theme factors and the treatment aspect with 4 theme factors. The main theme factors in the caregiver/patient aspect were enabling participation in physical activities and exercise (77.8%), perceptions regarding asthma and the need for long-term treatment (50.0%), and perceived value of the medications outweighing the risk of side effects (38.9%). The main theme factors in the treatment aspect were trust in the physician (77.8%), general satisfaction with the manner and attitude of the physician (77.8%) and verification of the necessity of further treatment by performing tests (38.9%). Conclusion : Efforts to improve caregivers' adherence to the treatment of childhood asthma must include a range of factors related to both caregiver/patient aspects and treatment aspects. Among all of these factors, it may be most important to establish a physician-caregiver partnership.

The Effects of Weighted Vest During Task-Oriented Training on Gross Motor Performance and Balance Abilities of Children With Spastic Diplegia : A Randomized Clinical Trial Study (경직형 양마비 아동의 과제지향훈련 시 무게조끼 적용이 대동작 수행력과 균형 능력에 미치는 영향: 무작위배정 위약비교 연구)

  • Kwon, Hae-Yeon
    • The Journal of Korean Academy of Sensory Integration
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    • v.15 no.2
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    • pp.46-65
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    • 2017
  • Objective : The purpose of this research is to find clinical effects of application of weighted vest during task-oriented training focused on gross motor performance and balance abilities of children with spastic diplegia. Methods : 34 subjects were divided by simple random sampling into two groups; experimental group (male : 9, female : 8, average age : 8.12) and placebo group (male : 9, female : 9, average age : 7.53). Both two groups underwent to 40 minute intervention, twice a week for 12 weeks. The intervention was task-oriented training focused on facilitating closed kinematic chain and multi-joint functional movement pattern. During the training, the experimental group received loaded-resistance weighted vest and placebo group also received weighted vest but without loaded-resistance. Participants in both groups underwent 8 to 10 reps of the task-oriented training and there were 3 minutes break time between tasks. There were pre-test of gross motor performance and balance abilities, and two times of post-tests were performed upon 6 weeks and 12 weeks after the intervention completed. And in final, an additional follow-up test was performed 12 weeks after the evaluation was finished in order to find any difference between the two groups over time. Results : There was significant difference in Gross Motor Performance Measure (GMPM) between two groups. It is found that average score of the experimental group increased more than the placebo group after 6 weeks and 12 weeks intervention (p<.05). There was significant difference in Pediatric Berg's Balance Scale (PBS) between two groups. It is found that average score of the experimental group increased more than the placebo group after 6 weeks and 12 weeks intervention (p<.05). Conclusion : Based on the results in this study, it is proposed that application of weighted vest into task-oriented training to facilitating closed kinematic chain and multi-joint movement can improve gross motor performance and balance abilities of children with cerebral palsy.

Effects of Total Sleep Deprivation on Fine Motor Performance (전수면박탈이 정상인의 미세운동수행 능력에 미치는 영향)

  • Lee, Heon-Jeong;Song, Hyung-Seok;Ham, Byung-Joo;Suh, Kwang-Yoon;Kim, Leen
    • Sleep Medicine and Psychophysiology
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    • v.8 no.2
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    • pp.129-137
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    • 2001
  • Objectives: The purpose of this study is to investigate the effects of 38-hour sleep deprivation on fine motor performance. The Motor Performance Series (MPS) in the Vienna Test System (computerized neurocognitive function tests) was used in this study. Methods: Twenty four subjects participated in this study. Subjects had no past history of psychiatric disorders and physical illness. Subjects had normal sleep-waking cycle without current sleep disturbances and were all right-handed (Annett's Hand Preference Questionnaire: above +9 points). To minimize the learning effects, familiarization with the Vienna Test System was performed one day before the study. Subjects were to get up at 6:00 in the morning after getting enough sleep according to his or her usual sleep-wake cycle. After awakening, subjects remained awake for 38 hours under continuous surveillance. During two consecutive study days, the subjects tested MPS at 7 AM and 7 PM each day, which means the MPS was done four times in total. During the experiment, anything that could affect the subjects' sleep such as coffee, tea, alcohol, a nap, tiring sports, and all medications were prohibited. Results: In MPS, the fine motor functions of both hands decreased after 38 hours of sleep deprivation. The decrement in motor performance was prominent in the dominant right hand. In the right hand, the total number of tapping was reduced (p<.005), and the number of misses (p<.05) and the length of misses (p<.05) of line tracking, the total length of inserting a short pin (p<.01), the total length of inserting a long pin (p<.05), and the number of misses in aiming (p<.05) increased. Such performance decrement was distinct in the morning sessions. Conclusions: These results suggest that fine motor performance decrement during sleep deprivation is predominant in the right hand, which exerts maximal motor function. The finding of decrement in motor function in tapping during sleep deprivation also suggested that the time required for exhaustion of muscles is shortened during sleep deprivation. More deterioration of motor performance was shown in the morning, which could be explained as circadian rhythm effects.

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