• Title/Summary/Keyword: Cold Weather

Search Result 520, Processing Time 0.031 seconds

The Treatment of Volatile Organic Compounds Using a Pilot-Scale Biofilter (Pilot 규모의 바이오필터를 이용한 휘발성유기화합물질 제거)

  • Son, Hyun-Keun
    • Journal of Environmental Health Sciences
    • /
    • v.30 no.3
    • /
    • pp.245-252
    • /
    • 2004
  • Two biofilter tests were conducted under different operating conditions. Test # 1 was performed to treat VOCs generated from a paint booth. The second test was performed to treat VOCs generated from chemical manufacturing processes. The volume of biofilter media was 4.3 $m^3$. For the test # 1, the biofilter was operated for 30 days with 99.9% reduction ratio. Range of temperature of each stage of the biofilter media was measured between $34^{\circ}C$ and $73^{\circ}C$. All the temperatures of stages reduced gradually after the initial dramatic increase. For the test # 2, the biofilter experiment was conducted for 14 days. In this case, the biofilter was installed outdoor and the experiment was performed during wintertime. Therefore, temperature management for the biofilter was needed. Seven-centimeter thick fiberglass insulation and $150^{\circ}C$ steam heating were used to overcome the outside freezing cold weather during test # 2. Temperature of stage # 5 was measured the highest and that of stage # 1 was the lowest. More acclimation time and test period was needed to determine the maximum loading rate.

Evaluations on the Compaction Energy Effects on the Soil Compaction at Sub-Zero Temperature (영하에서의 다짐에너지에 따른 다짐 효과 평가)

  • Lee, Jeonghyeop;Hwang, Bumsik;Chae, Deokho;Cho, Wanjei
    • Journal of the Korean GEO-environmental Society
    • /
    • v.16 no.8
    • /
    • pp.13-20
    • /
    • 2015
  • Due to the population growth and exhaustion of resource, the development on the harsh environment such as cold weather is emerging as an alternative for new resource development. The permafrost area covers about 14 percent of the world's land area and the global construction market for such area is rapidly expanded. Whereas the developed countries have already recognition of the need for research of coldest place and invested heavily in technology development, the domestic technology for the coldest place development is less developed and related research has rarely been performed. There is not a detailed national specification standard for the strength and deformation properties of the earthworks at sub-zero temperature but simple field directions. Therefore, the D compaction tests were conducted on the sand with fine contents of 0%, 5%, 10% and 15% at room temperature ($18^{\circ}C$), $-3^{\circ}C$ and $-8^{\circ}C$ to investigate the effect of the compaction energy on the compacted soils at sub-zero temperatures. Based on the test results, the larger compaction energy, the larger maximum dry unit weight under sub-zero temperature and D type compaction at $-3^{\circ}C$ show similar max. dry unit weights as those obtained from the compaction at the room temperature. However, compaction at $-8^{\circ}C$ showed significant performance degradation regardless of the compaction energy.

The Frost Heaving Susceptibility Evaluation of Subgrade Soils Using Laboratory Freezing System (실내 동상시스템을 이용한 노상토의 동상민감성 평가)

  • Shin, Eun Chul;Ryu, Byung Hyun;Park, Jeong Jun
    • Journal of the Korean Geosynthetics Society
    • /
    • v.12 no.2
    • /
    • pp.13-23
    • /
    • 2013
  • The Korean Peninsula is considered as a seasonal frozen area that is thawed in the spring and frozen in the winter. The influence of fines of the frost susceptibility of subgrade soils were established by laboratory freezing tests simulating closely the thermal conditions in the field. During the winter season, the climate is heavily influenced by the cold and dry continental high pressure. Because of siberian air mass, the temperature of January is $-6{\sim}-7^{\circ}C$ on average. This chilly weather generate the frost heaving by freezing the moisture of soil and damage potential of the geotechnical structure. In the freezing soil, the ice lenses increase the freeze portion of soil by absorbing the ground water with capillary action. However, the capillary characteristics differ from the sort of soil on the state of freezing condition. In this study, ten soil samples are prepared. The basic physical property tests were performed by following the Korean Industrial Standard and the soil specimens were classified by the Unified Soil Classification System (USCS). These classified soils are used to perform the laboratory opened systems freezing test in order to determine the frost heaving characteristics of soils such as unfrozen water content, heaving amount, and freezing depth.

Comparative Study on the Stress Response of Nurses Working on Pscychiatric Wards to that of Nurses Working on General Wards (정신과 병동 간호사와 일반병동 간호사의 스트레스 반응양상에 대한 비교연구)

  • 김영자
    • Journal of Korean Academy of Nursing
    • /
    • v.25 no.3
    • /
    • pp.399-418
    • /
    • 1995
  • The purpose of this study was to investigate the stress response of nurses working on psychiatric wards (psychiatric nurses) compared with that of nurses working on general wards (general nurses) in order to provide assessment data for intervention of the stress response. The Symptoms of Stress Inventory was used to measure the stress response. Data were collected by a direct survey method using a questionnaire and were collected from March first to March 30, 1995. A sample of 200 nurses working in three psychiatric hospitals and psychiatric wards in four university hospitals in Seoul and Kangwon province were selected and 200 nurses working on general wards from two general hospitals in Seoul were also selected for a total sample of 400 nurses. Nurses who had experienced more than one of the major life events in the last two years were excluded from the total number in the samples, so the final sample was 161 psychiatric nurses, and 169 general nurses. The Scores for the total stress response, scores of the SOS subscales, stress response by sociodemographic characteristics of the nurses working on the psychiatric wards were compared with those of nurses working on the general ward. The results of this investigation are as follows 1. The mean total SOS score for the psychiatric nurse was 0.81 (SD=0.48) and that of the general nurses was 0.90(SD=0.53). 2. The Mean score for peripheral manifestation, con tral-neurological symptoms, gastrointestinal symptoms, muscle tension, habitual patterns, de-pression, anxiety, anger and cognitive disorganization for the general nurses showed a tendency to be higher than those of the psychiatric nurses. Mean score for cardiopulmonary symptoms for the general nurses was significantly higher than that of the psychiatric nurses. 3. The mean scores for the sixteen SOS items for the general nurses was significantly higher than for the psychiatric nurses. The 16 items were flushing of the face, sweating excessively even in cold weather, thumping of the heart, rapid breathing, dry mouth, a choking lump in the throat, hoarseness, muscle tension in hands or arm, muscle tension in leg, working tiring one out completely, severe aches a핀 Pain make it diffi-cult to do the work, severe nervous exhaustion, worrying about health, feeling weak and faint, so upset that one wants to hit something, unable to keep thoughts from running through one's mind. The mean score of only 505 item were significantly higher for the psychiatric nurses. 4. Stress responses between psychiatric nurses and general nurses were significantly different according to the following demographic characteristics : marriage, duration of work, position, accommodation, planning to move into another working site, working ward, education in psychiatric nursing.

  • PDF

Development of Field Scale Model for Estimating Garlic Growth Based on UAV NDVI and Meteorological Factors

  • Na, Sang-Il;Min, Byoung-keol;Park, Chan-Won;So, Kyu-Ho;Park, Jae-Moon;Lee, Kyung-Do
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.50 no.5
    • /
    • pp.422-433
    • /
    • 2017
  • Unmanned Aerial Vehicle (UAV) has several advantages over conventional remote sensing techniques. They can acquire high-resolution images quickly and repeatedly. And with a comparatively lower flight altitude, they can obtain good quality images even in cloudy weather. In this paper, we developed for estimating garlic growth at field scale model in major cultivation regions. We used the $NDVI_{UAV}$ that reflects the crop conditions, and seven meteorological elements for 3 major cultivation regions from 2015 to 2017. For this study, UAV imagery was taken at Taean, Changnyeong, and Hapcheon regions nine times from early February to late June during the garlic growing season. Four plant growth parameters, plant height (P.H.), leaf number (L.N.), plant diameter (P.D.), and fresh weight (F.W.) were measured for twenty plants per plot for each field campaign. The multiple linear regression models were suggested by using backward elimination and stepwise selection in the extraction of independent variables. As a result, model of cold type explain 82.1%, 65.9%, 64.5%, and 61.7% of the P.H., F.W., L.N., P.D. with a root mean square error (RMSE) of 7.98 cm, 5.91 g, 1.05, and 3.43 cm. Especially, model of warm type explain 92.9%, 88.6%, 62.8%, 54.6% of the P.H., P.D., L.N., F.W. with a root mean square error (RMSE) of 16.41 cm, 9.08 cm, 1.12, 19.51 g. The spatial distribution map of garlic growth was in strong agreement with the field measurements in terms of field variation and relative numerical values when $NDVI_{UAV}$ was applied to multiple linear regression models. These results will also be useful for determining the UAV multi-spectral imagery necessary to estimate growth parameters of garlic.

A Study on the Origin and the Developing Process of Vest for Men (남성 Vest의 기원과 변천과정에 관한 연구)

  • 김서영;이순홍
    • The Research Journal of the Costume Culture
    • /
    • v.6 no.3
    • /
    • pp.56-72
    • /
    • 1998
  • Vest is a general term for a sleeveless upper garment and it derives from a kolobus of a sleeveless tunic style that was started to be worn as a substitution of a chiton by the peasantry in Greek period. The kolobus started to be called a colobium or a tunica from Roman period and the former was named for a vest style tunica which was worn by the people of the lower classes in early Roman period. Similarly, a German colobium of North Europe which was worn during the same period was the same kind of clothe as the Roman colobium. The colobium came to be worn over a dalmatica as an outer garment by early Christians when it was the Middle Ages, who succeeded the tradition of colobium as they went through ancient Rome, Creek and Byzantine days. North Germans also succeeded the colobium tradition of ancient Germans as it was and so continued to wear it in tight style. The simple vest style of colobium was getting vanished from the mid of the Middle Agnes and a new style of vest named jupon was started to be worn by soldiers. The jupon was to protect soldiers' bodies from either were cold weather or enemies wearing under armors as it was made with double cotton pad by quilt. From 14th century, the jupon began to be worn by not only soldiers but also the humble of lower classes. All the jupon which were made in quilting and padding of that time began to be named a pourpoint by the humble. When Renaissance in 16th century came, the pourpoint began to be developed to an exaggerating body-line style. The neckline of pourpoint was getting highly influenced by Spain and a peacecod-belly of it emphasized the exaggerated masculine beauty of Renaissance by padding in round. The sleeves were puffed out and the whole purpoint was made to expose an inner chemise by slashing vertically or obliquely. But in 17th century, the pourpoint has been changed into more simple style without padding, puffing out and slashing influenced by the citizens' clothes of Netherlands. The pourpoint came to be more comfortable bulky style with short sleeves or sleeveless and straight side lines. The pourpoint in mid 17th century turned to be a bolero jacket style by gradually being tightened. It had been then changed into a vest style with sleeves and worn under an overcoat with the name of vest in the end of 17th century. The early vest was 2∼3 inches les in length than the overcoat and had long sleeves and many ornamental buttons on front. It was also made as a home wear to be worn it alone at home. In 18th century, the length of the vest became shorter compared with that of 17th century and the most important decorative item in clothes. It again came to have complete sleeveless vest style and had very short length reaching waist in the end of 18th century. When it was in 19th century, the vest had developed into more various style and colors and style had been applied to be worn by individuals with their tastes. Around the end of 19th century, the increasing tendency to be casual by industrialization influenced on clothes in all aspects of life and so the male vest has been gradually changed into more casual style. Nowadays, it has been developing into various uses in modern male clothes to show their characters.

  • PDF

An Experimental Study on the Effect of Reduced Slag and Gypsum on Concrete at Low Temperature(-5℃) (저온(-5℃)에서의 환원슬래그 및 석고가 콘크리트에 미치는 영향에 관한 실험적 연구)

  • Kim, Hyeong-Cheol;Choi, Hyun-Kuk;Min, Tae-Beom;An, Dong-Hee;Choi, Si-Hyun;Lee, Han-Seung
    • Journal of the Korea Institute of Building Construction
    • /
    • v.17 no.3
    • /
    • pp.279-285
    • /
    • 2017
  • In this study, the development of concrete preventing initial frost damage and durability about that were evaluated by using anti-aging agent and admixture(reduced slag). As a result of experiment, initial hydration heat was increased by $C_{12}A_7$ of reduced slag components but it was not effective to development of strength. Also fluidity decreased with increasing replacement of reduced slag. This suggested that fluidity was low by rapid setting due to absent of gypsum in reduced slag components. In case of CR2G specimen that added 4% gypsum, the flow ability was higher than plain. It is considered that concrete developed using reduced slag should use $SO_3$. Result of durability experiments, the durability decreased with increasing replacement amount of reduced slag.

Development of Concrete Quality Inspection and Document Management System Using Mobile and Web Technologies (모바일 기술 및 웹을 활용한 콘크리트 품질시험 및 문서관리 시스템 개발)

  • Kim, Young-Suk;Lee, Jae-Kwon;Jung, Un-Suk
    • Korean Journal of Construction Engineering and Management
    • /
    • v.9 no.4
    • /
    • pp.193-205
    • /
    • 2008
  • Quality is an important keyword representing the corporate competitiveness and image in today' s construction industry. Especially in concrete construction, any problems or defects in fresh concrete can significantly degrade the entire quality and performance of the facility built. Thus, adequate quality inspection and testing must be exercised over the fresh concrete, if concrete with the required strength, durability and appearance is to be obtained. The testing of concrete delivered to the construction job site involves testing of fresh concrete and performing strength tests on hardened concrete. The principal tests conducted on fresh concrete include the slump test and tests for air and salt content. The temperature of fresh concrete should be checked out hot or cold weather concreting. The 7-day and 28-day strength of hardened concrete are also determined by compression tests on usually cylinder samples. However, it is very complex and time-consuming process requiring a lot of efforts to document those on-site concrete testing results and to accumulate their historical data. The primary objective of this study is to suggest a unique PDA and web-based system which enables an on-site quality manager to effectively conduct the concrete inspection and testing, automatically document and accumulate the collected historical data, and promptly obtain the approval from supervisors. Finally, it is anticipated that the effective use of the proposed PDA and web-based system would be able to improve reliability of the concrete quality inspection and testing data as well as significantly reduce the approval process.

Physical and Chemical Properties of Chlorine Bypass System-Dust from Cement Manufacturing (시멘트 생산 시 발생하는 Chlorine Bypass System-dust의 물리 및 화학적 특성)

  • Han, Min-Cheol;Lee, Dong-Joo
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.7 no.4
    • /
    • pp.310-315
    • /
    • 2019
  • This study conducted a series of studies to find alternative ways to use Chlorine Bypass System-dust(CBS-dust) in cement production. The results of engineering characteristics of CBS-dust are summarized as follows. First of all, the density of CBS-dust is 2.40, lighter than cement and the pH was 12.50 which was strong alkaline. In terms of particle size, it was 11.70 ㎛ which was finer than cement. With chemical properties, calcium oxide(CaO) was the highest as 35.10%, potassium oxide(K2O) was 32.43%, potassium chloride(KCl) was 19.46%, sulfur oxide(SO3) was 6.81%, and the remaining chemical components are SiO2, Fe2O3, Al2O3, MgO, and the like. Therefore, if CBS-dust is used as early-strength chemical admixtures in the concrete secondary products that use a large amount of mineral admixtures without rebar, it can be an effective method for increasing the strength of concrete as an alkali activator and preventing early-frost damage of Cold Weather Concrete.

Research on the Actual Conditions of the Outpatients who Visited the Pediatrics Department in $\bigcirc\;\bigcirc$ University Oriental Medicine Hospital between 2005 and 2006 (2005${\sim}$2006년 모 대학 부속한방병원 학생건강클리닉에 내원한 외래 환자 실태조사)

  • Yoon, Kyung-Hee;Koh, Duck-Jae;Kim, Deog-Gon
    • The Journal of Pediatrics of Korean Medicine
    • /
    • v.21 no.3
    • /
    • pp.125-143
    • /
    • 2007
  • Objective The purpose of this study was to investigate health and life style of pediatric outpatients who visited the oriental hospital. Methods The study was composed of 363 students from elementary school, middle school and high school who visited the pediatrics department in $\bigcirc\;\bigcirc$ university oriental medicine hospital between 2005 and 2006. Results 1. The group wasconsisted with 56% of male and 44% of female student and for the age distribution, 7.4% were elementary school students, 55.6% were middle school students, and 36.9% were high school students. 2. Usually the eldest child tends to visit hosipital more than the younger ones. 3. More than a half of those students' parent had University education or beyond that. 4. There were more students who had below the level of the height-weight curve than in the higher level. 5. The average study hours of the students were 3.67 hours. An average sleep hours was 6.18 hours. An average exercise hour was 1.16 hours and an average time for watching TV was 1.71 hours. 6. Many students had hard time to concentrate on the studying for a long time. 7. For the question about the reason why they got the poor grade, they answered because of the lower concentration, and they didn't put much effort on the studying. The most they concern about was their grade. 8. Most of the students who visited the clinic said they did not feel refreshed when they woke up in the morning, and, many of them said that they don't feel okay. 9. More than an half of the students wear glasses. 10. More than an half of the students answered that they often catch a cold when the weather changes a lot. 11. A lot of them had some digestive problems. 12. As they getting older, they said they often feel back pain and shoulder pain. 13. Many students felt irritated and got mad easily. Many of them felt bored about their study and stressed out because of their tests and the university entrance exams. 14. Most of the female students answered that they have irregular period or cramps. 15. 21% of them usually skip breakfast. 16. Many students enjoyed snacks. Most of them enjoyed snacks after school. As they go into higher grade, they would like to eat at night especially cookies, bread and fruits. Conclusions Further studies with larger sample size of students will be neededfor accurate results, and it would be better if we can compare the conditions of the students before treatments and after those.

  • PDF