• 제목/요약/키워드: dry-out

검색결과 2,692건 처리시간 0.027초

다양한 방법으로 가공한 건식공정 바텀애시를 사용한 콘크리트의 굳지 않은 상태에서의 특성 (Properties of Fresh Concrete with Dry Bottom Ash Processed by Various Method)

  • 선정수;최홍범;이명진;유재성;김진만
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2014년도 춘계 학술논문 발표대회
    • /
    • pp.92-93
    • /
    • 2014
  • This study was carried out to process the shape of dry bottom ash using the impact crusher and gravity crusher, which are identified as most effective in improving grain shape through the preceding research, and a comparison was made between concrete that utilized the processed dry bottom ash as aggregate and concrete containing dry bottom ash before processing to understand properties of the new concrete.

  • PDF

저온 냉풍시스템을 이용한 환경친화적 가공시스템의 성능평가 (Performance Evaluation of Environmentally Conscious Machining System Using Low Temperature Air System)

  • 배정철;김경중;김경중;강명창;김정석
    • 한국공작기계학회논문집
    • /
    • 제13권2호
    • /
    • pp.127-132
    • /
    • 2004
  • In industrially advanced countries, environmentally conscious machining was eagerly studied because of ecological and economical reasons. As the environmental regulations become stricter, the new machining technologies which take environmental aspects into consideration are being developed. Recently the research institutions have established application method for dry, semi-dry, oil-mist and compressed cold air machining. In this paper the performance of new compressed cold air system for environmentally conscious machining is investigated and machinability of dry and new compressed cold air machining is evaluated. A series of tests are carried out by using measuring equipments in condition of dry and compressed cold air machining.

근로자의 직무스트레스가 구강 건조감, 턱관절 증상 및 구강증상에 미치는 영향 (The Influence of occupational stress on dry mouth, temporomandibular disorder and oral symptoms on workers)

  • 홍민희
    • 한국치위생학회지
    • /
    • 제13권1호
    • /
    • pp.136-145
    • /
    • 2013
  • Objectives : The goal of this study is to investigate how occupational stress affects temporomandibular disorders (TMD), dry mouth and oral symptoms. Methods : For this study, workers from 5 areas were selected and the survey was carried out from June 1st to 30th, 2012. A total of 410 questionnaires were analyzed. Results : The analysis of the structural model shows that occupational stress has no significant influence on temporomandibular disorder and dry mouth symptoms, but does affect other oral symptoms. The results also reveal that dry mouth symptom and temporomandibular disorder both have a significant effect on oral symptoms. Conclusions : Oral symptoms and job stress appeared to directly and indirectly influence the psychological and social factors of job stress. A systemic investigation on the improvement of oral health in workers is urgently required.

Numerical modeling of seawater flow through the flooding system of dry ocks

  • Najafi-Jilani, A.;Naghavi, A.
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • 제1권2호
    • /
    • pp.57-63
    • /
    • 2009
  • Numerical simulations have been carried out on the flooding system of a dry located at the south coasts of Iran. The main goals of seawater flow haracteristics in the intake channels conditions of the flooding system are imposed in the modeling. The upstream boundary condition is the tidal fluctuations of sea water level. At the downstream, the gradually rising water surface elevation in the dry described in a transient boundary condition. The numerical results are compared with available laboratory a good agreement is obtained. The seawater discharge through the flooding system and the required time to filling up the dry dock is determined at the worst case. The water current velocity and pressure on the rigid boundaries are discussed.

ENHANCED BIOAVAILABILITY OF NIFEDIPINE USING COATED DRY ELIXIR

  • Park, Jae-Yoon;Kim, Chong-Kook
    • 한국응용약물학회:학술대회논문집
    • /
    • 한국응용약물학회 1996년도 춘계학술대회
    • /
    • pp.282-282
    • /
    • 1996
  • The purpose of this study was to prepare the nifedipine dry elixir (NDE) and coated nifedipine dry elixir (CNDE) containing nifedipine ethanol solution for improving the dissolution rate and bioavailability of nifedipine. NDE containing nifedipine and ethanol in wall materials of dextrin was prepared using a spray-dryer and then NDE was coated with eudragit acrylic resin to make CNDE. Shape and size of the NDE and CNDE were monitored by scanning electron micrograph and laser particle size analyzer In vitro dissolution tests were performed in simulated gastric and intestinal fluid. Bioavailability of NDE and CNDE were compared with drug powder suspension and commercial soft capsule after oral administration of the preparations to rats. NDE and CNDE are spherical in shape. Cross-sectional view of dry elixirs indicates the large inter cavity containing ethanolic drug solution in shell. Geometric mean diameter of NDE and CNDE is about 6.64 and 8.70 $\mu\textrm{m}$, respectively. Drug dissolution rate within first 5 min from NDE increased dramatically irrespective of dissolution medium. However, CNDE showed a particularly retarded dissolution rate in pH 1.2 simulated gastric fluid compared with NDE. The bioavailability of nifedipine in the NDE was increased dramatically compared with drug powder suspension. CNDE reduced initial burst-out plasma peak compared with NDE. CNDE as a sustained release delivery system could reduce the initial burst-out plasma peak due to controlling the release rate of nifedipine from NDE and maintain the effective plasma level over a longer period within therapeutic window with enhanced bioavailability of nifedipine.

  • PDF

Synthesis of $Li_xNi_(0.85)Co_(0.15)O_2$ by the PVA-procursor Method and the Effect of Air Flow During the Pyrolysis

  • 권호진;김근배;김수주;송미영;박선희;권혜영;박동곤
    • Bulletin of the Korean Chemical Society
    • /
    • 제20권5호
    • /
    • pp.508-516
    • /
    • 1999
  • Polycrystalline powder of LixNi0.85Co0.15O2 was synthesized by pyrolyzing a powder precursor obtained by the PVA-precursor method. Coin cells of lithium-ion rechargeable battery were assembled, whose the cathodes were fabricated from the crystalline powders of LixNi0.85Co0.15O2 synthesized by the method. The effect of synthetic variation on the property of the cell was tested by carrying out 100 consecutive cycles of charge-dis-charge on the cells. The property of the cell was largely influenced by the pyrolysis conditions applied for the synthesis of the LixNi0.85Co0.15O2. Depending on whether the pyrolysis was carried out in standing air or in the flow of dry air, the discharge capacity and cycle-reversibility of the cell varied in large extent. When the powder precursor was pyrolyzed in standing air, a minor phase of lithium carbonate was remained in the LixNi0.85Co0.15O2. The carbon containing powder precursor had to be pyrolyzed in the flow of dry air to eliminate the minor phase. In the flow of dry air, the lithium carbonate in the precursor was eliminated over 500-700。C without any prominent heat event. By controlling the flow of air over the precursor during its pyrolysis, particle size could also be altered. The effect of flowing dry air, during first step pyrolysis or during second step heat treatment, on the property of the cell was discussed.

밀폐형 2상 열사이폰의 열전달 특성에 관한 실험적 연구 (An Experimental Study on the Heat Transfer Characteristics of Two-phase closed Thermosyphon)

  • 조기현;백이;정형길
    • 한국산업융합학회 논문집
    • /
    • 제5권3호
    • /
    • pp.165-171
    • /
    • 2002
  • The thermosyphon has been used as a heat transmission device in the heat recovery of low level energy and cooling for heat generating equipments. Many studies on the working fluids and wicks have been reported to improve the heat transfer efficiency of the thermosyphon. A low temperature heat pipe with acetone is chosen in the present study to compare the heat transfer characteristics due to pouring amount of working fluid, magnitude of power supplied and tilt angles. The thermosyphon made ⵁ$15.88{\times}0.8t{\times}600mm$ of copper, evaporation section 200mm, insulation section 25mm, condensation 375mm. Heat transfer rate of the thermosyphon increase as magnitude of power supplied increase and observe dry out phenomenon at 5~10% of pouring amount of working fluid. So thermosyphon at the 150kJ/s judged to need 12% or more. Heat transfer rate of the thermosyphon have nothing to do with tilt angles. Dry out phenomenon of the thermo syphon makes it possible that a low temperature thermosyphon may be used to control temperature and heat transfer of a system when the critical quantity of a working fluid is supplied in the thermosyphon.

  • PDF

에탄올베이스 드라이샴푸의 항균력과 피부안전성 (Antimicrobial Activity and Skin Safety of Ethanol-Based Dry Shampoo)

  • 유철;정노희
    • 한국응용과학기술학회지
    • /
    • 제31권1호
    • /
    • pp.14-22
    • /
    • 2014
  • 본 연구에서는 거동이 불편한 환자와 바쁜 현대인들을 위하여 헹굼이 필요없는 에탄올베이스 드라이샴푸를 제조했다. 물로 헹구지 않는 드라이샴푸에는 저자극 세정원료의 적용이 필요하다. 이 실험에서 세정원료는 저자극 세정원료를 첨가하고 세정원료의 세포독성실험과 드라이샴푸의 피부자극, 항균효과를 확인하였다. 본 연구에서 펜틸렌글리콜을 적용하여 제조한 에탄올베이스 드라이샴푸가 항균력을 갖고 피부에 가장 안전함을 확인 하였다. 또한 미용목적뿐만 아니라 위생적인 모발관리를 가능하게 하여 젖은 샴푸를 할 수 없는 상황에서도 청결과 위생, 안전성을 동시에 만족할 수 있을 것으로 기대된다.

Dry Season Evaporation From Pine Forest Stand In The Middle Mountains Of Nepal

  • Gnawali, Kapil;Jun, KyungSoo
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2016년도 학술발표회
    • /
    • pp.330-330
    • /
    • 2016
  • The quantification of dry season evaporation in regions, where the magnitude of dry season flows is key to the regional water supply, is essential for good water management. Also, tree transpiration has a significant role in the water balance of a catchment whenever it is tree populated, especially in water limited environments. Such is the case in the Middle Mountains of Nepal where dry season flows play a significant role in downstream water provisioning and their proper functioning is key to the welfare of millions of people. This research seeks to study the transpiration of a pine forest stand in the Jikhu Khola Watershed in the Middle Mountains of Nepal. To the author's knowledge, no single study has been made so far to estimate the dry season evaporation from the planted forest stand in the Middle Mountains of Nepal. The study was carried out in planted pine forest embedded within the Jikhu Khola Catchment. Field campaigns of sap flow measurements were carried out from September, 2010 to February, 2011 in the selected plot of 15*15m dimension, to characterize dry season evaporation. This was done by measuring sap fluxes and sapwood areas over the six trees of different Diameter at Breast Height (DBH) classes. The sap flux was assessed using Granier's thermal dissipation probe (TDP) technique while sapwood area was determined using several incremental core(s) taken with a Pressler borer and immediately dyeing with methyl orange for estimating the actual depth of sapwood area. Transpiration of the plot was estimated by considering the contribution of each tree class. For this purpose, sap flux density, sapwood area and the proportion of total canopy area were determined for each tree class of the selected plot. From these data, hourly and diurnal transpiration rates for the plot were calculated for experimental period. Finally, Cienciala model was parameterized using the data recorded by the ADAS and other terrain data collected in the field. The calibrated model allowed the extrapolation of Sap flux density (v) over a six month period, from September 2010 to February 2011. The model given sap flux density was validated with the measured sap flux density from Grainier method.

  • PDF

2차원 유한요소해석을 위한 마름/젖음 알고리듬의 민감도 분석 (Sensitivity Analysis of Dry/Wet Algorithm for 2-Dimensional Finite Element Analysis)

  • 한건연;김상호;최승용;황재홍
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2009년도 학술발표회 초록집
    • /
    • pp.827-831
    • /
    • 2009
  • Recently, frequency occurring flood and drought has increased the necessity of an effective water resources control and management of river flows. Therefore, the simulation of the flow distribution in natural rivers is great importance to the solution of a wide variety of practical flow problems in water resources engineering. However The serious problem facing two-dimensional hydraulic model is the treatment of wet and dry areas. The objective of this study is to investigate the wet and dry parameters that have direct relevance to model performance in situations where inundation of initially dry areas occurs. Several numerical simulations were carried out, which examined the performance of the marsh porosity method for the purpose of sensitivity analysis. Experimental channel and a variety of channel were performed for model tests. The results were compared with those of the observation data and simulation data of existing model. The RMA-2 model displayed reasonable flow distribution compare to the observation data and simulation data of existing model in dry area for application of natural river flow. As a result of this study, effectively applied marsh porosity method provide a reliable results for flow distribution of wet and dry area, it could be further developed to basis for extending to water quality and sediment transport analysis.

  • PDF