• 제목/요약/키워드: discharge volume

검색결과 546건 처리시간 0.025초

Synthesis of Ultrafine Zr Based Alloy Powder by Plasma Arc Discharge Process

  • Lee, Gil-Geun;Park, Je-Shin;Kim, Won-Baek
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.420-421
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    • 2006
  • In the present study, ultrafined Zr-V-Fe based alloy powder prepared by a plasma arc discharge process with changing process parameters. The chemical composition of synthesized powder was strongly influenced by the process parameters, especially the hydrogen volume fraction in the powder synthesis atmosphere. The synthesized powder had an average particle size of 50 nm. The synthesized Zr-V-Fe based particles had a shell-core structure composed of metal in the core and oxidse in the shell.

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중환자실 입원환자의 눈 간호 프로토콜 적용 효과: 무작위 대조군 전후 실험연구 (Effectiveness of the Eye Care Protocol in the Intensive Care Unit Patients: A Randomized Controlled Trial)

  • 임규원;하신영;강인순
    • 대한간호학회지
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    • 제54권3호
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    • pp.432-445
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    • 2024
  • Purpose: This study investigated the effects of an eye care protocol (ECP) on patients in the intensive care unit (ICU). Methods: This study utilized a randomized controlled design. Participants were patients who met the inclusion criteria and were admitted to the ICU (36 in the experimental group and 38 in the control group). The experimental group received an ECP, while the control group received standard eye care, starting the day after admission, for a duration of 10 days. The ECP classifies the degree of eyelid obstruction into three stages based on the degree of exposure to the lower eyelid conjunctiva and cornea. The protocol included cleansing with normal saline gauze, administering eye drops, applying silicone and polyurethane films, and recommending consultation with an ophthalmologist if necessary. The effectiveness of ECP was assessed by analyzing tear volume, hyperemia, chemosis, and eye discharge. Data analysis was conducted using SPSS 27.0, employing the Mann-Whitney U-test and generalized estimating equations. Results: On day 5, the experimental group demonstrated a significant increase in tear volume in both eyes compared with the control group. However, no statistically significant differences were observed in the incidence of hyperemia, chemosis, and eye discharge on days 5 and 10 of the intervention. Conclusion: The application of the ECP in this study increased tear volume in ICU patients, thereby reducing discomfort caused by dry eyes. It has the potential to prevent complications such as damage to the surface of the eyeball resulting from decreased tear volume.

스프링클러 헤드의 방수상수에 따른 물방울 크기에 관한 실험적 연구 (An Experimental Study on Droplet Size according to Discharge Coefficient of Sprinkler Head)

  • 허민녕;신창섭
    • 한국안전학회지
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    • 제32권4호
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    • pp.16-21
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    • 2017
  • The sprinkler system is a basic fire extinguishing system that uses water as an extinguishing agent. In order to evaluate the fire extinguishing performance of the sprinkler system, information such as the discharge angle, discharge speed, discharge pressure, flow rate, and water droplet size of the installed head are required. However, there is a lack of research on droplets size compared to other requirements. In this study, to evaluate the extinguishing characteristics of sprinkler system, the droplet size distribution was measured for various types of sprinkler heads actually used. The size of the droplet was measured using laser diffraction method. The 50% cumulative volume distribution ($D_{v50}$) according to discharge coefficient(K factor) was $540{\mu}m{\sim}695{\mu}m$ for K50, $542{\mu}m{\sim}1,192{\mu}m$ for K80, $980{\mu}m{\sim}1,223{\mu}m$ for K115 and $1,188{\mu}m{\sim}1,234{\mu}m$ for K202. Based on the measured results, the vaeiance of the droplet particle distribution and the distribution ($D_{v50}$) according to discharge coefficient(K factor) was $540{\mu}m{\sim}695{\mu}m$ for K50, $542{\mu}m{\sim}1,192{\mu}m$ for K80, $980{\mu}m{\sim}1,223{\mu}m$ for K115 and $1,188{\mu}m{\sim}1,234{\mu}m$ for K202. Based on the measured results, the vaeiance of the droplet particle distribution and the Rosin-Rammler index value are presented. As a result of the fire simulation with FDS, it was confirmed that the performance difference occurs according to the water droplet size distribution even when the same amount of water is used. Therefore, the extinguishing performance of the sprinkler system should be evaluated considering the droplet size distribution according to the sprinkler head type.

경사지 밭에서 발생하는 토양유실 저감을 위한 피복재 적용 (Surface Cover Application for Reduction of Runoff and Sediment Discharge from Sloping Fields)

  • 신민환;원철희;박운지;최용훈;신재영;임경재;최중대
    • 한국농공학회논문집
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    • 제53권6호
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    • pp.129-136
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    • 2011
  • To measure effects of surface cover on runoff and sediment discharge reduction using rainfall simulator, four(5 m${\times}$30 m scale) plot experiments were conducted in this study. Surface covers made with straw mat, Polyacrylamide (PAM), chaff, and sawdust were simulated 4 times under 31.1~44.4 mm/hr rainfall intensities. Compared with results from control plot, the time of runoff generation is delayed and outflow volume decreased with surface cover. Effects on runoff reduction of straw mat, PAM, sawdust and chaff ranged 4.7~81.5 % and runoff rate reduced by 6.5~76.1 % respectively, when compared with those from control plot. The percentage of decrease in sediment discharge were 99.7~99.8 % from straw mat+sawdust+PAM plots, 85.9~95.6 % from straw mat+PAM plots, and 98.5~99.4 % from straw mat+chaff+PAM plots. The runoff, sediment discharge, and SS concentration reduction efficiencies of the cover materials were outstanding when compared to control plot. It was analyzed that reduction of runoff and sediment discharge were mainly contributed by decrease in rainfall energy impact and flow velocity and increase of infiltration due to the surface cover materials. The results could be used as a base for the development of best management practices (BMPs) to reduce runoff, sediment discharge from sloping field.

전기방전소결에 의해 제조된 다공성 및 다공성 표면을 갖는 Ti-6Al-4V 임플란트 : (1) 제조방법 및 기본적 특성 (Fully Porous and Porous Surfaced Ti-6Al-4V Implants Fabricated by Electro-Discharge-Sintering: (1) Fabrication Method and Fundamental Characteristics)

  • 현창용;허재근;이원희
    • 한국분말재료학회지
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    • 제12권5호
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    • pp.325-331
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    • 2005
  • Implant prototypes with various porosities were fabricated by electro-discharge-sintering of atomized spherical Ti-6Al-4V powders. Single pulse of 0.75 to 2.0 kJ/0.7 g-powder, using 150, 300, and $450{\mu}F$ capacitors was applied to produce a fully porous and porous surfaced implant compact. The solid core formed in the center of the compact after discharge was composed of acicular ${\alpha}+{\beta}$ grains and porous layer consisted of particles connected in three dimensions by necks. The solid core and neck sizes increased with an increase in input energy and capacitance. On the other hand, pore volume decreased with increased capacitance and input energy due to the formation of solid core. Capacitance and input energy are the only controllable discharge parameters even though the heat generated during a discharge is the unique parameter that determines the porosity of compact. It is known that electro-discharge-sintering of spherical Ti-6Al-4V powders can efficiently produce fully-porous and porous surfaced Ti-6Al-4V implants with various porosities in a short time less then 400 isec by manipulating the discharging condition such as input energy and capacitance including powder size.

휴반 살포용 노즐의 분무특성에 관한 연구 (A Study on the Characteristics of the Spraying Nozzle on Paddy Levee)

  • 최규홍;손낙율
    • 한국농공학회지
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    • 제17권2호
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    • pp.3758-3762
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    • 1975
  • In order to find out the optimum size of nozzle of the power sprayer in the paddy field, four different sized hole of nozzles were tested on its discharge volume per unit time and its effective covering distance. 1. The discharge rate of each nozzle is proportional to square root of the transmitted internal pressure of liquid, and the discharge coefficient ranges from 0.82 to 0.86 at the pressure of 20 to 30 kg/$\textrm{cm}^2$. 2. The effective covering distance is increased as the size of the hole is larded and also the pressure is increased under under the limited pressure. Generally, the effective covering distance is not greatly increased at the pressure of above 25kg/$\textrm{cm}^2$. The distance from the nozzle to the spot where the largest amount of droplets are dropped is about 14.5m for 3.05mm nozzle and 16m for 4.05mm nozzle in the pressure range from 20 to 25kg/$\textrm{cm}^2$. 3. From the above results it is concluded that the 3mm nozzle with the power sprayers, which are now being supplied to the farmers, can be used for disease and insect control on the paddy field of which block size is 30m${\times}$100m, and operators need not to enter the field for spraying. For the 40m${\times}$100m block, 4mm nozzle should be used with large size of pump which discharge capacity is 60l/min or more.

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한.중.미 중재인의 선정 및 기피에 관한 비교연구 (A Comparative Study on the Selection and Discharge of Arbitrator(s) among Korea, China and America)

  • 신군재
    • 한국중재학회지:중재연구
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    • 제21권1호
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    • pp.183-213
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    • 2011
  • China and North America have been South Korea's biggest trading partner long time. As the volume of trade has been increasing, the disputes between Korean companies and Chinese Companies and between Korean companies and North American Companies have been increasing. If these disputes are settled by Arbitration, the parties appoint arbitrators who are empowered to proceed the arbitration procedure and have a power to render an arbitral award. Accordingly, it is very important for the parties to select who is an arbitrators in Arbitration. But if the parties doubt their arbitrator(s)'s fairness and independency, they can discharge them in accordance to law and arbitration institute's rules. In comparison with arbitrator system for way of selection and discharge among Korea, China and North America, some differences are found. First, if parties fail to appoint co-arbitrators or the presiding arbitrator by a mutual agreement, the court has the right to appoint them or him in Korea and North America whereas the Chairman of CIETAC choose him in China. Second, the authority to decide whether arbitrator is discharged owing to his fairness and independency, depends on arbitration institute and court in Korea and North American whereas it depends on the Chairman of CIETAC only.

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압연이 Ni-MH 2차전지용 금속수소화물 전극의 충·방전 특성에 미치는 영향 (The Effect of Rolling on the Charge-Discharge Characteristic of Metal Hydride Electrode for Ni-MH Secondary Battery)

  • 박원;장상민;최승준;노학;최전;박충년
    • 한국수소및신에너지학회논문집
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    • 제7권2호
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    • pp.165-171
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    • 1996
  • The effect of rolling on the charge-discharge property was studied for metal hydride negative electrode. $(LM)Ni_{3.6}Al_{0.4}Co_{0.7}Mn_{0.3}$(pleateau pressure : below 1 atm at room temperature, volume expansion : 9%, entalpy : $8.7kcal/molH_2$) alloy was prepared by arc melting, and then it was coated with various copper weight percent. The copper coated alloys were then rolled with the different reduction ratio. From the results, it was found that the maximum discharge capacity increased with increasing reduction ratio, and 15wt% copper coated sample shows the highest discharge capacity, 324mAh/g, after rolling with 30% reduction ratio. In view of cycle life for the negative electrode, the 15wt% copper coated electrode which was rolled with 13% reduction ratio showed the longest cycle life compared with other electrodes.

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