• 제목/요약/키워드: Heart rate strain

검색결과 26건 처리시간 0.024초

여름철 포도 수확 작업 농민의 작업 환경 및 노동 부담 평가 (Evaluation of Farmer's Workload and Thermal Environment During Harvesting Grape in Summer)

  • 최정화;김명주;이주영
    • 대한가정학회지
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    • 제40권11호
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    • pp.193-205
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    • 2002
  • To evaluate farmers' workload during harvesting grapes in summer, this study investigated farmers' physiological, psychological responses, work postures and thermal environment around in the field. This field study was conducted in the Anseong County of Kyonggi Province at the end of August. Five career farmers (1 male, 4 females) volunteered as subjects. Three of them were over their sixties. During harvesting grapes in the field, physiological responses were monitored continuously. 1. Air temperature (T/sub a/), air humidity(H/sub a/), black globe temperature(T/sub g/), air velocity and WBGT around the grape field were 26.9℃, 77.7%RH, 32.8℃, 0.08㎧ and 26.3℃, respectively. Because farmers started the harvesting task in early morning, thermal environments weren't conditions to give farmers severe heat strain. 2. The percentage of the work postures was larger in order of standing, walking, and bending one's back posture. Particularly, the percentage of standing posture with raising both arms above shoulder of two farmers was up to 29% and 61% of the total work duration. 3. Rectal temperature (T/sub re/), mean skin temperature (T/sub sk/), clothing microclimate temperature (T/sub cl/) on the chest and the back, heart rate (HR) and energy expenditure (EE) were 37.2℃, 33.1℃, 32.0℃, 32.4℃, 88bpm and 1.3 Kca1/㎡/min respectively. In the point of these physiological results, we evaluated that the harvesting task was a moderate work. 4. All farmers expressed‘hard, hot, humid and slightly uncomfortable’ at the end of works for each subjective questionnaire. The grape harvesting tasks were not evaluated as a very hard work in the point of physiological work standards. But we considered 1) inappropriate work posture (standing posture with raising both arms above shoulder) and 2) farmers' age as burden factors. These findings suggest that adding adequate protective clothing/equipments for farmers may contribute to maintain their body temperature within the normal range, stabilize HR and decrease psychological strain.

Effects of Clothing Material Dyed with Astringent Persimmon Extract upon Exercise-Induced Thermal Strain and Sensory Responses in a Warm Environment

  • Park, Shin-Jung;Shin, Hye-Sun;Chung, Hee-Chung
    • International Journal of Human Ecology
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    • 제16권2호
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    • pp.1-9
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    • 2015
  • This study investigated the effects of persimmon-dyed clothing materials upon thermophysiological responses and subjective comfort sensations during exercise and rest in a warm environment. Six healthy, untrained women participated in two separate testing sessions, with cotton materials dyed with astringent persimmon extract (DC) and undyed cotton materials (UDC). The physical characteristics associated with heat and moisture transfer were improved in DC; also, stiffness, anti-drapery stiffness and crispness in the primary hand values were higher in DC. The experimental protocol consisted of a 10-min rest, 15-min exercise on a treadmill (at ${7km{\cdot}h^{-1}}$) and 25-min recovery at $28{\pm}0.2^{\circ}C$ and $50{\pm}3%\;RH$. The results were as follows: When wearing DC rather than UDC, mean body temperature, heart rate, heat storage and body mass loss were significantly lower during the whole experimental period. Clothing microclimate temperature showed different profiles between the two clothing materials, being lower with DC than UDC during the first half of exercise and the second half of recovery. Clothing microclimate humidity was significantly lower with DC than UDC during the whole experimental period. When wearing UDC, subjects felt significantly warmer and less comfortable during exercise, and sensed greater humidity during exercise and recovery. These results suggest that eco-friendly clothing materials dyed with astringent persimmon extract can reduce exercise-induced heat load and improve subjective sensations when exercising and resting in a warm environment, due to greater heat dissipation from the body to the outside environment compared with undyed clothing materials.

사지부의 냉각효율성에 관한 연구 (Local Cooling of the Limbs in $37^{\circ}C$ Ambient Temperature)

  • 황경숙;최정화;이경숙
    • 한국지역사회생활과학회지
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    • 제18권1호
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    • pp.87-95
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    • 2007
  • This study was to determine the effect of cooling parts of the limbs without harm to health. The results provide basic data for the development of clothing which could increase work efficiency and reduce body strain in hot environments. Five male adults took part in the study, conducted in a climate chamber with an ambient temperature of $37^{\circ}C$ and a relative humidity of 50%. The limbs were divided into six areas to be cooled: upper arm, forearm, thigh, calf, hand, and foot. According to preceding studies, permissible cooling safety limits of skin temperature for each part of the body for one-hour were $20^{\circ}C$ on the upper arm, forearm, thigh, and calf, and $23^{\circ}C$ on the hand and foot. For this reason, cooling the skin of each region was carried out at the above mentioned temperatures. In conclusion, cooling the hand and foot reduced perspiration, rectal temperature and heart rate. Therefore, the heat stress of workers exposed to hot environments would be reduced by decreased subjective sensations of heat and increased comfort. The effectiveness of cooling was better on the arm than on the leg.

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Evaluation of the Wet Bulb Globe Temperature (WBGT) Index for Digital Fashion Application in Outdoor Environments

  • Kwon, JuYoun;Parsons, Ken
    • 대한인간공학회지
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    • 제36권1호
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    • pp.23-36
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    • 2017
  • Objective: This paper presents a study to evaluate the WBGT index for assessing the effects of a wide range of outdoor weather conditions on human responses. Background: The Wet Bulb Globe Temperature (WBGT) index was firstly developed for the assessment of hot outdoor conditions. It is a recognised index that is used world-wide. It may be useful over a range of outdoor conditions and not just for hot climates. Method: Four group experiments, involving people performing a light stepping activity, were conducted to determine human responses to outside conditions in the U.K. They were conducted in September 2007 (autumn), December 2007 (winter), March 2008 (spring) and June 2008 (summer). Environmental measurements included WBGT, air temperature, radiant temperature (including solar load), humidity and wind speed all measured at 1.2m above the ground, as well as weather data measured by a standard weather station at 3m to 4m above the ground. Participants' physiological and subjective responses were measured. When the overall results of the four seasons are considered, WBGT provided a strong prediction of physiological responses as well as subjective responses if aural temperature, heart rate and sweat production were measured. Results: WBGT is appropriate to predict thermal strain on a large group of ordinary people in moderate conditions. Consideration should be given to include the WBGT index in warning systems for a wide range of weather conditions. However, the WBGT overestimated physiological responses of subjects. In addition, tenfold Borg's RPE was significantly different with heart rate measured for the four conditions except autumn (p<0.05). Physiological and subjective responses over 60 minutes consistently showed a similar tendency in the relationships with the $WBGT_{head}$ and $WBGT_{abdomen}$. Conclusion: It was found that either $WBGT_{head}$ or $WBGT_{abdomen}$ could be measured if a measurement should be conducted at only one height. The relationship between the WBGT values and weather station data was also investigated. There was a significant relationship between WBGT values at the position of a person and weather station data. For UK daytime weather conditions ranging from an average air temperature of $6^{\circ}C$ to $21^{\circ}C$ with mean radiant temperatures of up to $57^{\circ}C$, the WBGT index could be used as a simple thermal index to indicate the effects of weather on people. Application: The result of evaluation of WBGT might help to develop the smart clothing for workers in industrial sites and improve the work environment in terms of considering workers' wellness.

고온환경 하에서 착용하는 인체냉각 보조도구로서의 Cooling Vest 연구(1) -Local Cooling에 따른 인체의 온열생리학적 특성- (Efficacy of Cooling Vest for Auxiliary Body Cooling in Hot Environments (1) -Thermophysiological Response of Human Body in Local Cooling-)

  • 권오경;김진아;김태규
    • 한국의류산업학회지
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    • 제2권3호
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    • pp.265-271
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    • 2000
  • Heat stress results in fatigue, a decline in strength, alertness., and mental capacity. The problem is compounded when high humidity exists. To help relieve worker heat stress, many types of cooling units are marketed. While workers may experience some cooling, critical body core temperatures often continue to elevate. This study was designed to find the effects of three kinds of cooling vest with portable frozen gel strips on thermophysiological parameters and on temperature and humidity within clothing. The heart rate, rectal, and skin temperature as well as sweat rate and clothing microclimate were measured during 80 min in 5 healthy males. Inquiries were also made into the subjective rating thermal, humidity comfort, and fatigue sensations. The main findings in our experiments are as follows: (a) Physiological parameters such as rectal temperature was the lowest in garb A1, intermediate in garb A, and the highest in garb A2 throughout the experiment. And mean skin temperature was the lowest in garb A, intermediate in garb A1, and the highest in garb A2; (b) Temperature and humidity within clothing (back) were garb in Al, intermediate in garb A, and the highest in garb A2. But the temperature and humidity within clothing (chest) were garb in A, intermediate in garb A1, and the highest in garb A2; (c) Most participants (4 out of 5 persons) answered that they felt more comfortable and fatigueless in garb A1 than in garb A and A2. It is concluded that local cooling in garb A1 of the upper torso could physiological reduce the thermal strain in participants wearing cooling vest.

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Characterization and comparison of the pathogenicity of viscerotropic velogenic Newcastle disease virus isolates in Korea

  • Kim, Jae-Hong;Sung, Haan-Woo;Kim, Il-Hwan;Lee, Eun-Kyoung;Choi, Kang-Seuk;King, Daniel Jack
    • 대한수의학회지
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    • 제52권4호
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    • pp.213-221
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    • 2012
  • A total of 18 Newcastle disease virus (NDV) isolates that were recovered from 1949 through 1997 were characterized and pathotyped. All viruses were highly virulent as determined by intracerebral pathogenicity indices ${\geq}1.81$ in day-old. These pathotypes are typical for viscerotropic velogenic NDV (VVNDV) pathotype viruses. Some differences were observed for the chicken red blood cell elution rate and thermostability of the hemagglutinin at $56^{\circ}C$. Three antigenic groups were identified by a hemagglutination-inhibition assay using NDV monoclonal antibodies. And the predominant gross lesions were as follows: discharge from the nasal cavity, tracheal mucus, petechial hemorrhage in the heart fat, kidney urates and hemorrhage with or without necrosis in the gastrointestinal tract. Severe hemorrhagic or necrotic lesions were also noted in the lymphoid organs and were localized primarily in the spleen and cecal tonsil. However, differences in the occurrence and frequency of the gross lesions were observed between the virus strains. Among them, NDV strains that induced neurological symptoms belonged only to genotype VI. This strain had spread throughout Korea during the late 1980s to the 1990s, which suggests that specific VVNDVs genotypes might result in neurological symptoms.

상한론 증상에 근거한 진료기록부 작성에 대한 제언 (Suggestions for writing the medical records based on the symptoms in Sanghanron("傷寒論"))

  • 김상운;이홍규;정현종
    • 대한한의진단학회지
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    • 제18권2호
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    • pp.85-110
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    • 2014
  • Objectives This study intends to present the writing of standardized medical records based on Korean medicine on the basis of the Sanghanron symptoms. Methods 1. Excluding the sentences unrelated to the Sanghanron symptoms, the symptoms in the rest of sentences were extracted. 2. Classifying the extracted symptoms as per the review of system, the similar symptoms were integrated. 3. Calculating the frequencies of each symptom, each strain rate was calculated. Results & Conclusion: 1. Resulting from the analysis on 378 sentences in Sanghanron, a total of 1566 different symptoms were extracted. 2. As results out of total, the symptom related to the temperature sensation accounted for 17.9%, that related to sweat did 6.5%, that related to pulse did 12.4%, that related to eye and nose and mouth and tongue and throat as well as thirst did 7.7%, that related to stool did 11.6%, that related to urination and urinary organs did 4.9%, that related to language and mind and sleep and agitation as well as heart did 10.0%, and that related to vomiting and abdomen as well as digestive organs did 15.4%. 3. There were found many symptoms were described in accordance with the severity of basic expressions. For examples, in case of fever, there were mild fever and high fever, and in case of sweat, there were profuse sweating and slightly sweating. 4. To create the medical records for cold damage disease, it may necessary to consider the factors to be recorded as per each symptom and write the detail of each symptom.

농약 방제 작업자의 작업 환경 및 노동 부담 평가 (Evaluation of the thermal environments and the workload of farmers during the spraying pesticide in the rice field)

  • 최정화;이주영
    • 한국의류학회지
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    • 제26권11호
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    • pp.1672-1681
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    • 2002
  • To evaluate the thermal environments and the workload of farmers in the rice field in summer, this study investigated rice farmers' physiological, psychological responses, work postures, work clothes, air temperature and air humidity during the spraying pesticide in the rice field. Five career farmers (3 males, 2 females) volunteered as the subjects. During the spraying pesticide in the rice field, physiological responses were monitored continuously. The results were as follows. l. Farmers wore only raincoats not pesticide-proof clothing. 2. The value of WBGT, rectal temperature($T_{re}$), mean skin temperature(${\={T}}_{sk}$) were $24.9∼28.9^{\circ}C,\;37.8({\pm}0.3)^{\circ}C\;and\;33.6({\pm}0.6)^{\circ}C$, respectively. Clothing microclimate temperature($T_{cl}$) on the chest and back were $32.5({\pm}2.6)^{\circ}C\;and\;33.6({\pm}2.6)^{\circ}C$, respectively(p<0.00l). Humidity inside of the clothing ($H_{cl}$) was over 80%RH and heart rate(HR) was 112(${\pm}27$)bpm. We evaluated that the spraying pesticide was 'heavy work' by the Tre and HR. To four subjective questionnaires, all farmers expressed 'hard, hot, humid and uncomfortable' without individual difference at the end of works. We suggested that 1) the spraying pesticide in the rice field was a heavy work, 2) because the workload of farmers in the raincoat/pesticide-proof clothing can't be evaluated by only WBGT, assessors should measure physiological, psychological responses as well as thermal environments, 3) to alleviate farmers' heat strain, clothing manufacturers must consider not only the improvement of textile materials and clothing weight but also the designing of personal cooling equipment.

거미의 감각기관을 모사한 초민감 균열기반 진동압력센서 (Ultrasensitive Crack-based Mechanosensor Inspired by Spider's Sensory Organ)

  • 오수연;김태일
    • 마이크로전자및패키징학회지
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    • 제31권1호
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    • pp.1-6
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    • 2024
  • 거미는 진동감각기관을 통하여 미세한 진동까지도 감지해낸다. 뛰어난 진동 감지 능력을 활용해 먹이나 포식자가 발생시키는 진동을 감지하여 공격을 계획하거나 위협을 파악하며 생존에 활용한다. 본 논문은 거미의 진동감각기관을 모사하여 개발된 초민감 진동압력센서에 대해 기술한다. 거미가 진동을 감지하는데 사용하는 감각기관에 위치한 작은 틈에 착안하여 센서에 균열을 생성하였고, 균열의 깊이를 제어하여 외부로부터 오는 압력이나 진동을 매우 민감하게 감지할 수 있는 센서를 개발하였다. 이 센서는 10 N의 인장응력을 적용하여 2%의 변형률에서 게이지 계수가 16000에 도달한다. 이는 높은 신호대잡음비를 가져 정확하게 원하는 진동을 인식할 수 있는 소자로서 외력(압력, 진동)과 생체 신호측정 등 다양한 평가를 통해 센서의 높은 민감도를 증명하였다. 이를 통하여 생체모사 기술을 활용한 새로운 센서의 개발 및 다양한 산업 분야로의 응용 가능성을 제시한다.

Optimal Conditions for the Production of Gamma-aminobutyric Acid by Enterococcus casseliflavus PL05 Isolated from Oenanthe javanica

  • Choi, Se Mi;Kim, Jeong A;Kim, Geun Su;Kwon, Do Young;Kim, Sang Gu;Lee, Sang yun;Lee, Kang Wook
    • 한국식품위생안전성학회지
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    • 제37권1호
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    • pp.21-28
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    • 2022
  • 본 연구에서는 국내산 돌미나리에서 GABA생성능이 있는 신규 유산균을 분리, 동정한 결과, Enteroccoccus casseliflavus로 확인되었다. 최근까지 Lactobacillus속과 같은 GABA 생성 유산균에 대한 보고는 많이 되고 있고, 일부 Enterococcs속 유산균도 보고되고 있으나 E. casseliflavus종에 대한 보고는 없었다. 따라서 본 연구에서는 E. casseliflavus PL05 균주에 대한 GABA 생성 최적 조건을 찾기 위하여 배지의 유형, 생육 온도, 초기 pH 조건, 배양 시간, MGS 농도 및 탄소원을 포함한 다양한 조건을 테스트하였다. PL05 균주는 MRS 혹은 TSB 배지보다 BHI 배지에서 생육이 잘 되었으며, 배지의 초기 pH는 7-9 조건에서 가장 생육이 왕성하였고, GABA 생성 조건 역시 유사한 결과로 확인되었다. GABA의 기질에 해당하는 MSG의 농도별 GABA 생성량을 조사한 결과, 7%에서 가장 높은 생성량을 나타내었으나 5%에서도 유사한 수준으로 확인되어 효율적인 측면에서 5%가 적합할 것으로 판단된다. 탄소원에 따른 생육 및 GABA 생성량은 말토오스를 사용하였을 때 가장 높은 것으로 확인되었고, 이러한 최적의 조건들로 최종 테스트를 진행한 결과, 24시간째 140.06±0.71 mM의 GABA가 생성되었고, 전환율은 78.95%로 확인되었다. 또한 반코마이신을 포함한 10개의 항생제에 대한 감수성을 조사한 결과 내성이 없는 것을 확인하였다.