• Title/Summary/Keyword: Pump system

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Sampling and Analysis of Soil Pore Water for Predicting the Diffusion and Behavior of Soil Pollutant Using Soil Lysimeter (토양라이시미터를 이용한 토양오염확산.거동 예측을 위한 토양공극수 채취와 분석)

  • Ko, Il-Won;Lee, Se-Yong;Kim, Kyoung-Woong;Lee, Jin-Soo
    • Economic and Environmental Geology
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    • v.40 no.5
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    • pp.551-561
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    • 2007
  • This case study is about the sampling and interpretation of soil pore water in order to understand and to predict the diffusion and behavior of soil pollution. For the measurement of polycyclic aromatic hydrocarbons(PAHs) in two representative hydrocarbon-contaminated sites, the extraction system of the soil pore water was set up with respect to soil depths and the behavior of contaminants was interpreted. The soil solution extraction system consisted of peristaltic pump, and extraction and sampling compartment, and can measure simultaneously the soil water pressure. The concentration of PAHs with respect to extraction pressure and time decreased due to dilution through soil pore water. Particularly, the concentration of PAHs was more reduced under the unsaturated oxic condition than saturated anoxic condition. Therefore, the soil solution extraction with respect to soil water pressure can interpret the extent of equilibrium between porewater and soil surface.

An Analysis of the Application Technology of Heat Recovery System from Dyeing Wastewater (염색폐수 열회시스템 적용기술 분석)

  • 장기창;박성룡;이상남;라호상;박준택;함성원;박영태
    • Journal of Energy Engineering
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    • v.10 no.3
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    • pp.195-205
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    • 2001
  • A great deal of energy is necessary with emission of lots of wastewater in dyeing and finishing process, but heat recovery from wastewater is not introduced since is technology is not developed yet. In order to obtain the method utilizing hot water produced by heat source, that is, dyeing wastewater it was investigated the characteristics of dyeing and finishing process and energy basic unit. Energy basic unit of polyester/cotton (T/C), polyester/rayon (T/R) and polyester dyeing process are higher than that of the other process. The average quantity of wastewater for each dyeing company is 20,470 ton/month, the average temperature of wastewater is about 41$^{\circ}C$. Because the SS solution of wastewater in polyester dyeing process is lower than that of the other process, the effect of corrosion in heat recovery system is low. Since the energy price for 1000 kcal produced by vapor compression heat pump is presumed to be 22.50 won, it is found to be very economic heat recovery system, and its payback is 2.09 years for the factory with LNG boiler.

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Kilohertz Gain-Switched Ti:sapphire Laser Operation and Femtosecond Chirped-Pulse Regenerative Amplification (KHz 반복률에서의 Ti:sapphire 이득 스위칭 레이저 발진과 펨토초 처프펄스 재생 증폭)

  • Lee, Yong-In;Ahn, Yeong-Hwan;Lee, Sang-Min;Seo, Min-Ah;Kim, Dai-Sik;Rotermund, Fabian
    • Korean Journal of Optics and Photonics
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    • v.17 no.6
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    • pp.556-563
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    • 2006
  • We present a comprehensive study of a chirped pulse Ti:sapphire regenerative amplifier system operating at 1 kHz. Main constituents of the system are described in detail. The amplifier stage was first converted to a repetition rate-tunable kHz gain-switched nanosecond Ti:sapphire laser. Operation characteristics at different repetition rates such as build-up times of laser pulses, pump power-dependent output powers and pulse durations, damage thresholds, and tunability ranges were studied. Based on the results achieved, the switching time of the Pocket's cell used and the round trip numbers in the regenerative amplifier were optimized at 1 kHz. The output pulses with a pulse width of 50fs from a home-made Ken lens mode-locked Ti:sapphire oscillator were used as seed pulses. The pulses were expanded to 120ps in a grating stretcher prior to coupling into the 3-mirror amplifier cavity. After amplification and recompression, a stable 1kHz Ti:sapphire regenerative amplifier system, which delivers 85-fs, $320-{\mu}J$ pulses, was fully constructed.

Research Background and Plan of Enhanced Geothermal System Project for MW Power Generation in Korea (MW급 EGS 지열발전 상용화 기술개발사업의 추진 배경 및 계획)

  • Yoon, Woon-Sang;Song, Yoon-Ho;Lee, Tae-Jong;Kim, Kwang-Yeom;Min, Ki-Bok;Cho, Yong-Hee;Jeon, Jong-Ug
    • Tunnel and Underground Space
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    • v.21 no.1
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    • pp.11-19
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    • 2011
  • Geothermal energy is believed to be an important source among the renewable energy sources to provide the base load electricity. Although there has been a drastic increase in the use of geothermal heat pump in Korea, there is no geothermal power plant in operation in Korea. Fortunately, the first EGS (Enhanced Geothermal System) Project in Korea has started in Dec 2010. This five year project is divided into two stages; two years for exploration and drilling of 3 km depth to confirm the minimum target temperature of 100 degrees, and another three years composed drilling 5 km doublet, hydraulic stimulation of geothermal reservoir with expected temperature of 180 degrees (40 kg/s) and construction of MW geothermal power plant in the surface. This EGS project would be a landmark effort that invited a consortium of industry, research institutes and university with expertises in the fields of geology, hydrogeology, geophysics, geomechanics and plant engineering.

A Study on the Optimal Operation and Policy of the Boryeong Dam Diverion Pipe Line Using the SWAT Model (SWAT 모형을 이용한 보령댐 도수로 운영 방안 및 정책 연구)

  • Park, Bumsoo;Yoon, Hyo Jik;Hong, Yong Seok;Kim, Sung Pyo
    • Journal of Korean Society on Water Environment
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    • v.36 no.6
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    • pp.546-558
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    • 2020
  • While industrialization has provided in abundance, the pollution it creates has caused untold damage to the environment, increasing the frequency and severity of natural disasters through changes in global climate patterns. The World Risk Forum's (WEF) World Risk Report presented the results of a survey of experts from around the world detailing the most influential risk factors over the next decade. Notably, the failure to respond to climate change ranked first and the global water crisis third. The extreme drought in the western Chungnam province was unexpected in 2016. At the time, the water level of Boryeong Dam was drastically decreased due to receiving less than half the average recorded rainfall in the region that year. The Boryeong Dam diversion pipeline has the capacity to solve the water shortage problem between these two regions by providing water from Geumgang to the western part of Chungnam, including Boryeong City. Current weather trends suggest drought is likely to continue in western Chungnam, which uses the Boryeong Dam as an intake source. This makes it necessary to operate Boryeong Dam diversion pipeline in an efficient and effective manner. SWAT is a watershed scale model developed to predict the impact of land management practices on water. The SWAT model was used in this study to evaluate the adequacy of the Boryeong Dam diversion pipeline operational plan by comparing it to present Boryeong Dam diversion pipeline operation. By investigating the number of days required to reach each reservoir stage, we determined that the number of days required to reach the boundary stage was less than that of the current operation. This determination accounts for the caveats that the Boryeong Dam waterway was not operated and only one pump will be operated from October to May of next year. As our results suggest, the most stable operation scenario is to operate two pumps at all times. This can be accomplished by operating two pumps from the caution stage to increase the number of pumps whenever the stage is raised. In addition to the stable operation of the Boryeong Dam pipeline, policy considerations are required with regard to imposing a water use charge on users of the Boryeong Dam region.

Research to Predict the Thermal Characteristics of Electro Hydrostatic Actuator for Aircraft (항공기용 전기-정유압식 작동기(Dual Redundant Asymmetric Tandem EHA)의 열특성 예측을 위한 연구)

  • Kim, Sang Seok;Park, Hyung Jun;Kim, Daeyeon;Kim, Dae Hyun;Kim, Sang Beom;Lee, Junwon;Choi, Jong Yoon
    • Journal of Aerospace System Engineering
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    • v.16 no.3
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    • pp.84-92
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    • 2022
  • The electro-hydrostatic actuator (EHA) recently has been used in flight control fields for aircraft because of its benefits of minimizing oil leakage and weight, improving safety, and etc. while independently operating the hydraulic power source and eliminating complex hydraulic piping. The aircraft of which EHA is installed inside, has the thermal management issue of EHA, because of its limited cooling source as compared with the aircraft which installs the traditional central hydraulic system. So, the thermal analysis model which predicts the thermal characteristics of EHA, is required to resolve this thermal management issue. In this study, an oil circulation circuit inside the hydraulic power module comprised of hydraulic pump and electrical motor for EHA was applied. This is for the purpose of developing the internal rotary group of hydraulic power module, which operates under the conditions of high rotation speed and hydraulic pressure. After formulating an appropriate thermal analysis model, the thermal analysis results with oil cooled or no oil cooled hydraulic control module were compared and reviewed, for the purpose of predicting the thermal characteristics of EHA.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2016 (설비공학 분야의 최근 연구 동향 : 2016년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.6
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    • pp.327-340
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    • 2017
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

The Scattering Beam Measurement of the RBC and the Fabrication of the Micro Cell Biochip (적혈구의 산란빔 측정과 마이크로 세포 분석 바이오칩 제작)

  • Byun, In Soo;Kwon, Ki Jin;Lee, Joon Ha
    • Progress in Medical Physics
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    • v.25 no.2
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    • pp.116-121
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    • 2014
  • Next future, The bio technology will be a rapidly developing. This paper is the scattering beam measurement of the red blood cell (RBC) and the fabrication of the micro cell biochip using the bio micro electro mechanical system (Bio-MEMS) process technology. The Major process method of Bio-MEMS technology was used the buffered oxide etchant (BOE), electro chemical discharge (ECD) and ultraviolet sensitive adhesives (UVSA). All experiments were the 10 times according to the process conditions. The experiment and research are required the ultraviolet expose, the micro fluid current, the cell control and the measurement of the output voltage Vpp (peak to peak) waveform by scattering angles. The transmitting and receiving of the laser beam was used the single mode optical fiber. The principles of the optical properties are as follows. The red blood cells were injected into the micro channel. The single mode optical fiber was inserting in the guide channel. The He-Ne laser beam was focusing in the single mode optical fiber. The transmission He-Ne laser beam is irradiating to the red blood cells. The manufactured guide channel consists of the four inputs and the four outputs. The red blood cell was allowed with the cylinder pump. The output voltage Vpp waveform of the scattering beam was measured with a photo detector. The receiving angle of the output optical fiber is $0^{\circ}$, $5^{\circ}$, $10^{\circ}$, $15^{\circ}$. The magnitude of the output voltage Vpp waveform was measured in the decrease according to increase of the reception angles. The difference of the output voltage Vpp waveform is due differences of the light transmittance of the red blood cells.

Study on Applicability of Simultaneous Multiple Compaction Grouting Method in Soft Clay Ground (점성토 연약지반에서의 다중 동시주입 컴팩션 그라우팅 공법 적용성 연구)

  • Lee, Hyobum;Jung, Hyun-Seok;Jung, Eui-Youp;Choi, Hangseok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.6
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    • pp.779-788
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    • 2019
  • The compaction grouting method is one of the conventional ground improvement methods, which consolidates and compacts the surrounding ground through the injection of grout materials with low mobility. Injecting the grout into the ground can improve the soil properties, as well as form a composite of soil-grout columns. However, the conventional grout pumping is not applicable to handle multiple injection holes at the same time, which may diminish its constructability when the construction time is not enough. This paper proposes a simultaneous multiple compaction-grouting method using a new pump system developed to cover up simultaneously three injection holes at a time. Field injection tests with a single injection hole and with triangular arrangement of injection holes were conducted to evaluate the applicability of the proposed method to soft clay ground. In addition, a series of standard penetration tests (SPTs) were performed to assess the efficiency of each arrangement in improving the soft ground. It is noted from the in-situ test results that the interval distances between injection holes and the elapse time for ground stabilization are the crucial factors governing the applicability of the simultaneous multiple compaction-grouting method to improve the soft clay ground.

Quantitative Analysis of Ergosterol as a Biomarker of Mold-contaminated Foods Using the Enzyme Biosensor (효소 바이오센서를 이용한 식품의 곰팡이 오염 지표물질인 Ergosterol 정량분석)

  • Kim, Mi-Kyeong;Kim, Jong-Won;Kim, Mee-Ra
    • Korean journal of food and cookery science
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    • v.25 no.2
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    • pp.252-259
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    • 2009
  • Ergosterol is the significant component of the cell wall of fungi. Its presence is regarded as evidence of fungi contamination in grain and other foods. Many studies on ergosterol detection have been carried out using chemical methods, but those methods required complicated pre-treatments and long analysis times. In this study, an amperometric biosensor was developed for fast and precise ergosterol detection. The biosensor system used the electron transfer of hydrogen peroxide produced from the reaction of ergosterol with cholesterol oxidase. The biosensor system consisted of a peristaltic pump, a syringe loading sample injector, an enzyme reactor, a fabricated flow-through cell containing a working electrode, a reference electrode and a counter electrode, and a potentiostat/recorder. The working electrode was prepared by coating modified multi-wall carbon nanotube (MWNT) on glassy carbon electrode. The $MWNT-NH_2$ coated glassy carbon electrode linearly responded to hydrogen peroxide in the range of $1{\times}10^{-5}{\sim}8{\times}10^{-5}$ M with a detection limit of $10^{-7}$ M in the basic performance test. The currents produced from the ergosterol biosensor showed the linearity in a range from $1.0{\times}10^{-6}$ M to $1.0{\times}10^{-5}$ M ergosterol.