• Title/Summary/Keyword: Adverse conditions

Search Result 537, Processing Time 0.021 seconds

무 유식물에서의 니켈내성과 히스티딘의 작용 (Nickel Tolerance and the Complexing Role of Histidine in Raphanus sativus)

  • 김태윤;홍정희
    • 한국환경과학회지
    • /
    • 제13권8호
    • /
    • pp.711-719
    • /
    • 2004
  • The effect of nickel (Ni) on growth and some tolerance strategies with regard to heavy metal tolerance mechanism was investigated in radish (Raphanus sativus) seedlings. The protective effect of histidine on nickel stress conditions was also monitored. The seedling growth decreased with an increase in metal concentrations. The inhibitory effect was more pronounced in the root elongation than in the shoot elongation. Increasing Ni supply showed a progressive increase of Ni concentrations in the roots and shoots. Ni content was higher in the shoots than in the roots. In the presence of nickel, radish exhibited an antioxidative defense mechanism, as evidenced by the elevated malondialdehyde(MDA), showing that nickel is an efficient inducer of lipid peroxidation. Exposure of radish to elevated concentrations of nickel was accompanied by an increase in the proline content. Supplemental histidine in the presence of Ni ameliorated metal-induced growth inhibition and lipid peroxidation. Combinations of Ni and histidine resulted in a significant decline in proline content compared with Ni stress alone, indicating that histidine may provide protection against the adverse effect of Ni stress. From the results it is suggested that histidine is an efficient chelator by complexing metal ion within the plant and may playa role in nickel tolerance implicated in metal detoxification.

Glycerol 후처리에 의한 Free-formaldehyde 발생 억제 효과 (The Effects of Glycerol Aftertreatment for Low-Formaldehyde Finishing)

  • 최석철;김호정
    • 한국의류학회지
    • /
    • 제10권2호
    • /
    • pp.59-67
    • /
    • 1986
  • To control the amounts of formaldehyde released from the cotton fabric finished with N-methylol compounds, glycerol was used as a formaldehyde-scavenging agent. It was observed the effects of catalysts and curing conditions when aftertreated with glycerol on melamine resin finished fabric. The effects of Different processes of glycerol treatment, and different resins, urea resin and melamine resin, were compared. The conclusions obtained from the results are as follows: 1) It was shown hatt the aftertreatment with glycerol (treated without catalyst) was more effective than treated with catalysts in controlling free formaldehyde. 2) The optimum curing temperature and curing time for the glycerol aftertreatment without adversely affecting the other properties of fabric was about $160^{\circ}C$, 3 min. 3) According to the increase of glycerol concentration in both aftertreatment and simultaneous treatment the amounts of free formaldehyde was reduced. The rate of decrease was manifest within the limits of $6\%$ in the case of simultaneous treatment with glycerol ana resins, and $3\%$ in the case of glycerol aftertreatment on resin finished fabrics. 4) Dry wrinkle recovery angle was decreased the increase of glycerol concentration. Melamine resin had a little adverse effect than urea resin, particulary glycerol aftertreatment. 5) The breaking strength was increased with the increase of glycerol concentration.

  • PDF

Critical setback distance for a footing resting on slopes under seismic loading

  • Shukla, Rajesh Prasad;Jakka, Ravi S.
    • Geomechanics and Engineering
    • /
    • 제15권6호
    • /
    • pp.1193-1205
    • /
    • 2018
  • A footing located on slopes possess relatively lower bearing capacity as compared to the footing located on the level ground. The bearing capacity further reduces under seismic loading. The adverse effect of slope inclination and seismic loading on bearing capacity can be minimized by proving sufficient setback distance. Though few earlier studies considered setback distance in their analysis, the range of considered setback distance was very narrow. No study has explored the critical setback distance. An attempt has been made in the present study to comprehensively investigate the effect of setback distance on footing under seismic loading conditions. The pseudo-static method has been incorporated to study the influence of seismic loading. The rate of decrease in seismic bearing capacity with slope inclination become more evident with the increase in embedment depth of footing and angle of shearing resistance of soil. The increase in bearing capacity with setback distance relative to level ground reduces with slope inclination, soil density, embedment depth of footing and seismic acceleration. The critical value of setback distance is found to increase with slope inclination, embedment depth of footing and density of soil. The critical setback distance in seismic case is found to be more than those observed in the static case. The failure mechanisms of footing under seismic loading is presented in detail. The statistical analysis was also performed to develop three equations to predict the critical setback distance, seismic bearing capacity factor ($N_{{\gamma}qs}$) and change in seismic bearing capacity (BCR) with slope geometry, footing depth and seismic loading.

정신 신체의학에서 최신 치료 약물 (Drug Treatment in Psychosomatic Disease)

  • 송지영
    • 정신신체의학
    • /
    • 제9권2호
    • /
    • pp.133-142
    • /
    • 2001
  • 정신 신체 장애 환자를 치료하는데 있어서는 우선 광범위한 정신선체 장애에서 이용되는 향정신 약물 뿐만이 아니라 관련 내과 치료 약물에 대한 기본적인 지식과 활용책이 요망(要望)된다. 그리고 다양한 종류의 치료 약물과 치료 방법은 환자의 질병관, 질병행동에 의거하여 변형될 수 있어야 한다. 최근에 소위 대체치료에서 활용되는 한약제, 생약제제, 향기 치료 등에 대해서, 적어도 이것이 결정적인 부작용이 없다면 의사가 적극적으로 활용(活用)하는 자세가 바람직하다. 그리고 약물 작용 등의 과학적인 기전과 효험도는 의사의 주도(主導) 하에 연구해 나가야 할 것이다.

  • PDF

거대 점 오염원의 플룸에 의한 시정 장애 효과 연구 (A Study on Visibility Impairment Impact of the Plume from a Vast Point Source)

  • 배주현;김유근
    • 한국대기환경학회지
    • /
    • 제15권5호
    • /
    • pp.599-611
    • /
    • 1999
  • Now that the plume of point source was suspected to have strong impact on visibility impairment in Pusan, we evaluated visibility impairment impact of the pulme from Pusan Thermo Electric Power Plant in Pusan. Level-1 and-2 analyses were carried out using VISCREEN(Visual Impact Screen model). The emission rates for this Pusan Thermo Electric Power Plant was projected to be 116g/s of nitrogen oxides(as $NO_2$). The source fails the level-1 test with a Plume perceptibility(ΔE) of 30, nearly 15 times the screeing threshold. To characterize worstcase meteorological conditions for level-2 screening, we obtained meteorological data from Mar., 1996 to Feb., 1997 of Pusan Thermo Electric Power Plant. The source fails the level-2 test with a ΔE of 17, nearly 8.5 times the screening threshold. These analyses indicated that adverse visibility impairment could not be ruled out. Therefore a Level-3 analysis was performed using PLUVUE II(Plume Visibility model). As a result, maximum reduction of visual range for 0900LST in winter was 0.9%. Visual impact of the plume from vast point source was judged to be considerable in terms of background visibility of urban area.

  • PDF

상향 링크 셀룰러 환경에서 반복 수신 기법을 적용한 부호화된 주파수 도약 OFDMA 시스템의 성능 (Performance of a Coded Frequency Hopping OFDMA System with an Iterative Receiver in Uplink Cellular Environments)

  • 김윤희;강성교
    • 한국통신학회논문지
    • /
    • 제30권11C호
    • /
    • pp.1108-1115
    • /
    • 2005
  • 패킷 기반 셀룰러 시스템의 상향 링크에서 동기 복조를 위해 LDPC 부호화된 주파수 도약 OFDMA 시스템에 알맞은 실제적인 반복 채널 추정 및 복호 기법을 제안한다. 제안한 기법은 파일롯 심볼과 LDPC 복호 결과를 함께 이용하여 반복적으로 채별 이득과 비균일 간섭 잡음을 추정함으로써 LDPC 복호 입력의 신뢰성을 향상시키고, 추정된 채별 상관 계수에 따라 채널 추정 필터를 선택함으로써 채널 변화를 잘 추적한다. 제안한 수신 기법의 성능을 다양한 채널 환경 및 수신 조건 아래 모의 실험한 결과 파일럿 심볼의 전력 증가 없이 채널 추정 성능을 향상시키고 비균일 셀간 간섭의 영향을 줄이는 것을 볼 수 있다.

Cold facade형 BIPV시스템의 발전성능 분석 (Analysis of Performance of Building Integrated PV System of Cold Facade type)

  • 김현일;강기환;박경은;유권종;서승직
    • 한국태양에너지학회:학술대회논문집
    • /
    • 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
    • /
    • pp.275-280
    • /
    • 2008
  • Photovoltaic(PV) permit the on-site production of electricity without concern for fuel supply or environmental adverse effects. The electrical power is produced without noise and little depletion of resources. So BIPV(Building-Integrated Photovoltaic) system have been increased around the world. Hereby the relative installation costs of the system will be relatively low compared to traditional installations of PV in high-rise buildings. This paper examined possibility of BIPV system of cold facade type and analyzed of performance of BIPV system of cold facade type. The system is influenced by conditions such as irradiation, module temperature, shade and architectural component etc. If this BIPV system of 1.1kW is possible the natural ventilation in the summer case, the temperature of PV module decrease and then the efficiency of PV system increase generally. By the results, the annual averaged PR of BIPV system of cold facade type is about 73.1%.

  • PDF

손동작에 따른 손체표 길이 변화를 적용한 장갑 설계 평가 (Evaluation of Glove Designs Applying Change in Hand Length Dimensions by Hand Motion)

  • 권오채;선미선;정기효;이민정;연수민;유희천;김희은
    • 대한인간공학회지
    • /
    • 제24권4호
    • /
    • pp.15-21
    • /
    • 2005
  • Use of a glove made of materials with a low elasticity decreases the performance of the hand such as agility, dexterity, range of motion, and grip strength. The present study examined if the adverse effects of a low-elastic glove can be reduced by a design which accommodates the changes of hand surface lengths by hand motion. Two glove designs which provide patches of elastic cloth and pleats at the finger joints and knuckle were developed by considering the hand surface length changes, and then compared with two conditions(bare hand and conventional glove design that does not consider the dynamic characteristics of the hand dimensions) in terms of completion time in peg board insertion task, maximum grip strength, discomfort in hand motion, discomfort in force exertion, and overall discomfort by 24 right-handed participants. The test results confirmed that wearing of a glove significantly reduced the agility and grip strength capability of the hand and indicated that the novel designs were effective to lessen the performance decreases compared to the conventional design. Also, of the glove designs, the pleat glove design was found most preferred for both better hand performance and less subjective discomfort.

In vitro maturation of human oocytes: Its role in infertility treatment and new possibilities

  • Chang, Eun Mi;Song, Hang Seok;Lee, Dong Ryul;Lee, Woo Sik;Yoon, Tae Ki
    • Clinical and Experimental Reproductive Medicine
    • /
    • 제41권2호
    • /
    • pp.41-46
    • /
    • 2014
  • IVM refers to the maturation of immature oocytes in culture after their recovery from small antral follicles at the stage prior to selection and dominance. IVM requires little or no FSH in vivo and has been proposed as an alternative to conventional IVF, since it reduces the primary adverse effects caused by controlled ovarian stimulation, including the ovarian hyperstimulation syndrome. Moreover, IVM is a promising option for cases for which no standard protocol is suitable, such as FSH resistance, contraindications for ovarian stimulatory drugs, and the need for urgent fertility preservation. Recently, IVM has been used in women with regular cycles and normal ovaries. However, the pregnancy rate following IVM is suboptimal compared with that of conventional IVF, indicating that further studies to optimize the protocol and the culture conditions are warranted.

극한지 모듈러 건축물의 설계, 시공 및 거주환경에 대한 연구 (A Study of Modular Architecture's Design to Dwelling Environment in Antarctica)

  • 이원학;송영학;임석호
    • 한국주거학회논문집
    • /
    • 제25권2호
    • /
    • pp.11-18
    • /
    • 2014
  • This study looked at designing, building and operating temporary camp, the first structures that South Korea built in the Antarctica. While there may be differences in accordance with the topography, ground surfaces in the Antarctica are covered broken stones, glaciers and snow. Hence, such topographical characteristics should be taken into account when conducting any construction work. To ensure successful assembly construction in the Antarctica using modules, prior trial assembly work should be done in Korea to identify any possible trouble in the actual construction process. Assuming that the workers will have to spend at least one winter in the temporary camp, the work will be more severely affected by adverse weather conditions and snow drift, resulting in the need to clear snow. This can be by designing roofs with curved surfaces. Also, quantitative effects will need to be verified through simulation and actual measurement. It will also be necessary to assess the camp's thermal environment and examine its air-conditioning methods. To identify the temporary camp's thermal system, the temperatures and humidities were measured, and the heating system was designed not to offer automatic control or desired value selection functions.