• Title/Summary/Keyword: water pressure sensor

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Ultrasonic Sensor Controlled Sprayer for Variable Rate Liner Applications (초음파센서를 이용한 변량제어 스프레이어)

  • Jeon, Hong-Young;Zhu, Heping
    • Journal of Biosystems Engineering
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    • v.36 no.1
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    • pp.15-22
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    • 2011
  • An experimental variable rate nursery sprayer was developed to adjust application rates for canopy volume in real time. The sprayer consisted of two vertical booms integrated with ultrasonic sensors, and variable rate nozzles coupled with pulse width modulation (PMW) based solenoid valves. A custom-designed microcontroller instructed the sensors to detect canopy size and occurrence and then controlled nozzles to achieve variable application rates. A spray delivery system, which consisted of diaphragm pump, pressure regulator and 4-cycle gasoline engine, offered the spray discharge function. Spray delay time, time adjustment in spray trigger for the leading distance of the sensor, was measured with a high-speed camera, and it was from 50 to 140 ms earlier than the desired time (398 ms) at 3.2 km/h under indoor conditions. Consequently, the sprayer triggered 4.5 to 12.5 cm prior to detected targets. Duty cycles of the sprayer were from 20 to 34 ms for senor-to-canopy (STC) distance from 0.30 to 0.76 m. Outdoor test confirmed that the nozzles were triggered from 290 to 380 ms after detecting tree canopy at 3.2 km/h. The spray rate of the new sprayer was 58.4 to 85.2% of the constant application rate (935 L/ha). Spray coverage was collected at four areas of evergreen canopy by water sensitive papers (WSP), and ranged from 1.9 to 41.1% and 1.8 to 34.7% for variable and constant rate applications, respectively. One WSP area had significant (P < 0.05) difference in mean spray coverage between two application conditions.

Evaluation of Optimum Moisture Content for Composting of Beef Manure and Bedding Material Mixtures Using Oxygen Uptake Measurement

  • Kim, Eunjong;Lee, Dong-Hyun;Won, Seunggun;Ahn, Heekwon
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.5
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    • pp.753-758
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    • 2016
  • Moisture content influences physiological characteristics of microbes and physical structure of solid matrices during composting of animal manure. If moisture content is maintained at a proper level, aerobic microorganisms show more active oxygen consumption during composting due to increased microbial activity. In this study, optimum moisture levels for composting of two bedding materials (sawdust, rice hull) and two different mixtures of bedding and beef manure (BS, Beef cattle manure+sawdust; BR, Beef cattle manure+rice hull) were determined based on oxygen uptake rate measured by a pressure sensor method. A broad range of oxygen uptake rates (0.3 to 33.3 mg $O_2/g$ VS d) were monitored as a function of moisture level and composting feedstock type. The maximum oxygen consumption of each material was observed near the saturated condition, which ranged from 75% to 98% of water holding capacity. The optimum moisture content of BS and BR were 70% and 57% on a wet basis, respectively. Although BS's optimum moisture content was near saturated state, its free air space kept a favorable level (above 30%) for aerobic composting due to the sawdust's coarse particle size and bulking effect.

Thermosalinograph Measurements in the Western Pacific Ocean in May and June, 2001 (2001년 5월과 6월 서태평양에서의 Thermosalinograph 관측)

  • Lee, Jae-Hak;Chung, Byoung-Chul;Hwang, Keun-Choon;Jeon, Dong-Chull;Hwang, Sang-Chul;Lee, Ha-Woong
    • Ocean and Polar Research
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    • v.24 no.3
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    • pp.207-213
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    • 2002
  • We have analyzed sea surface temperature and salinity data collected in the western Pacific Ocean by using an automated Thermosalinograph (TSG) installed on the RV Onnuri during May - June of 2001. The TSG data exhibit characteristics of water masses distributed in the near surface layer of the cruise area very well. Especially, they reveal the diurnal surface temperature cycle and the effect of rainfall on temperature and salinity in the equatorial region, showing the effectiveness of the use of TSG. Problems to be improved for the better TSG operation are the method of water sampling and calibration of TSG sensors. Installation of a pressure gauge in the TSG system and periodical sensor calibration are strongly recommended to ensure reliability of data.

An Ultrasonic Application with High Frequency for the Efficiency Elevation of the Hydrogen Fuel Production (On the Pole Interval and the Temperature) (수소연료 생산의 효율향상을 위한 고주파수 초음파 응용 (극간격과 온도 중심으로))

  • Song, Min-Geun;Son, Seung-Woo;Ju, Eun-Sun
    • Journal of Hydrogen and New Energy
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    • v.13 no.2
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    • pp.127-134
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    • 2002
  • A Study on the application of ultrasonic with high frequency is carried out as a plan to rise the efficiency of the hydrogen fuel production in an electrolysis of water. KOH is selected as an electrolyte and concentrations are 0 %, 10 %, 20 %, and 30%. The solvent is city water. A measurable device of buoyancy by an electronic balance and a measurable device of voltage with a sensor of pressure are planned newly as a measuring device to measure the quantity of hydrogen production. An ultrasonic transducer with high frequency of 2 MHz is selected to give them the ultrasonic forcing. In results, it is clarified that ultrasonic influences the decrease of overpotential in the electrolytic solution. And basic data according to the pole interval and the temperature are obtained.

An experimental study on the liquid rocket engine combustion gas cooling (액체로켓 엔진 연소가스 냉각에 관한 실험적 연구)

  • 김현중;유석진;임하영;우유철
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2003.05a
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    • pp.266-269
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    • 2003
  • During liquid rocket engine combustion, the resulting combustion gas has flow characteristics of high temperature and high velocity. An experimental study was performed to obtain basic data for a flame deflector design that is endurable under such flow characteristics. While the injected-water cools down the combustion plume, temperature and pressure of the plume was measured. As the experiment is being performed, gas temperature was measured using infrared cameras, and the gas temperature data was compared with the temperature data from the sensor in the plume. With the results of this experiment, we were able to obtain applicable temperature data for flame deflector design and predict the performance and structural strength required for installation of water injector.

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The development for flooding prevention apparatus of electrical equipment using air pressure (공기압을 이용한 전기설비 침수 방지 장치 개발에 관한 연구)

  • Kim, Gi-Hyun;Jean, Hyun-Jae;Lee, Sang-Ick;Bae, Suk-Myong;Lee, Jae-Yong
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.05a
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    • pp.281-284
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    • 2008
  • Inundation of substation and ground power equipment breaks out every summer season in low-lying downtown and low-lying shore by localized heavy rain, typhoon and tidal wave. In case inundation excluding the exchanging cost of equipment, it occurs a great economic and social loss owing to recovery time and events of electric shock occur by inundation electrical equipment(Pad-mounted Transformer and Switch). In case of installing the power equipment at flood danger territory, we are necessary to the product development, the product is that water does not come in the inside the power equipment. Product of pressure maintaining are established on the basic frame and sensor operates at the flooding occurrence and is maintained a shutting tightly structure and it is a method. The product which is produced the reliability of the product it confirmed a flooding yes or no from the condition which puts in the water tank and it verified. We estimate that loss cost which is caused by with flooding and the power failure will be diminished if it is addition to advances the reliability evaluation and a security of the flood protection product.

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A Study on the Priority Order Evaluation of the Water Supply Monitoring Technology Development for the Intelligent Underground Facility Management (지능형 지하시설물관리를 위한 상수도 모니터링 기술개발의 우선순위 평가에 관한 연구)

  • Kim, Jung-Hoon;Yi, Mi-Sook;Han, Jay-Il
    • Spatial Information Research
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    • v.16 no.2
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    • pp.263-278
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    • 2008
  • Nowaday, local governments have planned to manage intelligent underground facilities through the u-City project. But, the intelligent underground facilities are in need of the progressive approach because of the required huge financial resources. Therefore, the objectives of this research are (1) to prioritize the monitoring items of sensing technology developments, (2) to study technological feasibilities, and (3) to discover the killer application which expands ripple effects on economy. To achieve these objectives, final monitoring items were derived from the business analysis of the water supply, the local government survey, the hearing expert opinions and so on. The priority order of final monitoring items were technology developments of (1) the flowmeter flux, (2) the water leakage/crack, (3) the pressure of water supply pipes, and (4) the flux of filtration plants. The research significance is obtained from the derivation and the evaluation of the priority order and the actual demand for the water supply facility management. And, the research results will contribute to the strategic planning for the underground facility intelligence.

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Development of the Filterable Water Sampler System for eDNA Filtering and Performance Evaluation of the System through eDNA Monitoring at Catchment Conduit Intake-Reservoir (eDNA 포집용 채수 필터시스템 개발과 집수매거 취수지 내에서의 성능평가)

  • Kwak, Tae-Soo;Kim, Won-Seok;Lee, Sun Ho;Kwak, Ihn-Sil
    • Korean Journal of Ecology and Environment
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    • v.54 no.4
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    • pp.272-279
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    • 2021
  • A pump-type eDNA filtering system that can control voltage and hydraulic pressure respectively has been developed, and applied a filter case that can filter out without damaging the filter. The filtering performance of the developed system was evaluated by comparing the eDNA concentration with the conventional vacuum-pressured filtering method at the catchment conduit intake reservoir. The developed system was divided into a voltage control (manual pump system) method and a pressure control (automatic pump system) method, and the pressure was measured during filtering and the pressure change of each system was compared. The voltage control method started with 65 [KPa] at the beginning of the filtering, and as the filtering time elapsed, the amount of filtrate accumulated in the filter increased, so the pressure gradually increased. As a result of controlling the pressure control method to maintain a constant pressure according to the designed algorithm, there was a difference in the width of the hydraulic pressure fluctuation during the filtering process according to the feedback time of the hydraulic pressure sensor, and it was confirmed that the pressure was converged to the target pressure. The filtering performance of the developed system was confirmed by measuring the eDNA concentration and comparing the voltage control method and the hydraulic control method with the control group. The voltage control method obtained similar results to the control group, but the hydraulic control method showed lower results than the control group. It is considered that the low eDNA concentration in the hydraulic control method is due to the large pressure deviation during filtering and maintaining a constant pressure during the filtering process. Therefore, rather than maintaining a constant pressure during filtering, it was confirmed that a voltage control method in which the pressure is gradually increased as the filtrate increases with the lapse of filtering time is suitable for collecting eDNA. As a result of comparing the average concentration of eDNA in lentic zone and lotic zone as a control group, it was found to be 96.2 [ng µL-1] and 88.4 [ng µL-1l], respectively. The result of comparing the average concentration of eDNA by the pump method was also high in the lentic zone sample as 90.7 [ng µL-1] and 74.8 [ng µL-1] in the lentic zone and the lotic zone, respectively. The high eDNA concentration in the lentic zone is thought to be due to the influence of microorganisms including the remaining eDNA.

Experiment on Settling Velocity of Suspended Mineral Particles (부유된 광물성 입자의 침강 속도에 관한 실험)

  • Kim, Jong-Woo
    • Journal of Korea Water Resources Association
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    • v.40 no.9
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    • pp.723-734
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    • 2007
  • This study was to investigate the settling velocity which is an important factor for the prediction of cohesive deposition under the various densities of particle and dissolved ion addition$(Na^+,\;Cl^-,\;OH^-,\;H^+)$ in rivers, ports, reservoirs and lakes. Settling velocity of suspended fine particles in still water was measured with a pressure sensor (maximum 10 mbar). At the initial concentration of 20g/l of alumina and quartz the average settling velocities were high due to the aggregation behaviour of particles. At this point it was 0.185 mm/s (alumina) and 0.022 mm/s (quartz). Above this initial concentration it was on the decrease owing to the hindered settling. The higher the salinity is, the faster the settling velocity of alumina and quartz is. Furthermore, in an acid condition the average settling velocity of alumina was on the decrease. In an alkaline water, which causes strong flocculation, the average settling velocity of alumina it was observed on the increase. However, in an alkaline medium the low average settling velocity of quartz powder was measured.

Determination of Water Content in Compacted Bentonite Using a Hygrometer and Its Application (습도계를 이용한 압축벤토나이트 내 함수율 결정 및 적용)

  • Lee, Jae-Owan;Cho, Won-Jin
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.7 no.2
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    • pp.101-107
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    • 2009
  • Investigation of resaturation and thermal-hydro-mechanical behavior for the buffer of a repository requires measuring the water content of compacted bentonite. This study investigated the relative humidity of compacted bentonites using a humidity sensor (Vaisala HMT 334) applicable under high temperature and pressure, and then conducted a multi-regression analysis based on the measured results to determine relationships among the water content, relative humidity, and temperature. The relationships for the compacted bentonites with the dry densities of 1,500 $kg/m^3$ and 1,600 $kg/m^3$ were expressed as ${\omega}=0.196RH-0.029T+1.391({r^2=0.96)}$ and ${\omega}=0.199RH-0.029T+2.596({r^2=0.98)}$, respectively. These were then used to interpret the resaturation of bentonite blocks in the KENTEX test.

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