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  • Title/Summary/Keyword: High-pressure experiment

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Growth Characteristics of Lettuce under Low Pressure (저압조건에서 상추의 생육 특성)

  • Park, Jong-Hyun;Kim, Yong-Hyeon
    • Journal of Bio-Environment Control
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    • v.18 no.4
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    • pp.303-308
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    • 2009
  • This study was conducted to analyze the feasibility of plant growth under low pressure and to investigate the effect of pressure on plant growth. Three levels of pressures (25, 50, and 101.3 kPa (control)) were provided to analyze the growth of Lettuce (Lactuca sativa L.) as affected by low pressure. Photoperiod, air temperature, and photosynthetic photon flux were set at 16/8 h, 26/18C, and 240μmolm2s1, respectively. Growth characteristics of lettuce were measured on 7 days and 14 days after experiment. Leaf length, leaf width, leaf area, and root dry weight of lettuce measured on 7 days under 25 and 50 kPa were significant as compared to the control. Leaf length, top dry matter and root dry matter of lettuce measured on 14 days were significantly different under 25 and 50 kPa. From these results, we confirmed that lettuce could be grown under low pressure. However high relative humidity by evapotranspiration from leaves and growing beds under low pressure caused the condensation on the inner surface of the chamber. Therefore in a low pressure chamber, humidity control is required to maintain the relative humidity at a proper level.

Features Extraction for Classifying Parkinson's Disease Based on Gait Analysis (걸음걸이 분석 기반의 파킨슨병 분류를 위한 특징 추출)

  • Lee, Sang-Hong;Lim, Joon-S.;Shin, Dong-Kun
    • Journal of Internet Computing and Services
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    • v.11 no.6
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    • pp.13-20
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    • 2010
  • This paper presents a measure to classify healthy persons and Parkinson disease patients from the foot pressure of healthy persons and that of Parkinson disease patients using gait analysis based characteristics extraction and Neural Network with Weighted Fuzzy Membership Functions (NEWFM). To extract the inputs to be used in NEWFM, in the first step, the foot pressure data provided by the PhysioBank and changes in foot pressure over time were used to extract four characteristics respectively. In the second step, wavelet coefficients were extracted from the eight characteristics extracted from the previous stage using the wavelet transform (WT). In the final step, 40 inputs were extracted from the extracted wavelet coefficients using statistical methods including the frequency distribution of signals and the amount of variability in the frequency distribution. NEWFM showed high accuracy in the case of the characteristics obtained using differences between the left foot pressure and the right food pressure and in the case of the characteristics obtained using differences in changes in foot pressure over time when healthy persons and Parkinson disease patients were classified by extracting eight characteristics from foot pressure data. Based on these results, the fact that differences between the left and right foot pressures of Parkinson disease patients who show a characteristic of dragging their feet in gaits were relatively smaller than those of healthy persons could be identified through this experiment.

An Experimental Study on the Effect of Capillary Pressure on the Void Formation in Resin Transfer Molding Process (수지이동 성형공정에서 기공형성에 미치는 모세관압의 영향에 관한 실험적 연구)

  • 이종훈;김세훈;김성우;이기준
    • The Korean Journal of Rheology
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    • v.10 no.4
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    • pp.185-194
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    • 1998
  • Flow-induced voids during resin impregnation and poor fiber wetting give serious effects on the mechanical properties of composites in resin transfer molding process. In order to better understand the characteristics of resin flow and to investigate the mechanism of void formation, flow visualization experiment for the resin impregnation was carried out on plain weaving glass fiber mats using silicon oils with various viscosity values. The permeability and the capillary pressure for the fiber mats of different porosities were obtained by measuring the penetration length of the resin with time and with various injection pressure. At low porosity and low operating pressure, the capillary pressure played a significant role in impregnation process. Video-assisted microscopy was used in taking the magnified photograph of the flow front of the resin to investigate the effect of the capillary pressure on the void formation. The results showed that the voids were formed easily when the capillary pressure was relatively high. No voids were detected above the critical capillary number of 2.75×$10^{-3}, and below the critical number the void content increased exponentially with decrease of the capillary number. The content of void formed was independent of the viscosity of the resin. For a given capillary number, the void content reduced with the lower porosity of the fiber mat.

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Effect of High Pressure on Polarographic Parameters of 1-(2-Pyridylazo)-2-naphthol and 4-(2-Pyridylazo)-resorcinol in Methanol-Water Mixed Solution (메탄올-물 混合溶媒中에서 1-(2-Pyridylazo)-2-naphthol과 4-(2-Pyridylazo)-resorcinol의 폴라로그래프법적 파라미터에 미치는 壓力의 影響)

  • Heung Lark Lee;Zun Ung Bae;Jong Hoon Yun
    • Journal of the Korean Chemical Society
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    • v.29 no.3
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    • pp.197-204
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    • 1985
  • The dependence of polarographic parameters on pressure and temperature for the reduction of 2.0 ×104M 1-(2-pyridylazo)-2-naphthol (PAN) and 5.0 ×104M 4-(2-pyridylazo)-resorcinol(PAR) in buffered methanol-water mixed solution at the dropping mercury electrode, has been discussed. In this experiment the temperature is varied from 25C to 35C and the pressure is ranging from 1 atmosphere to 1,800 atmospheres. The reduction half-wave potentials are shifted to the more positive potentials with increase in pressure. The diffusion currents of two depolarizers become considerably larger with increase in pressure from 1 atmosphere to about 1,000 atmospheres but are getting smaller above 1,000 atmospheres. The slopes of log plot become much larger with increase in pressure, which indicates the more irreversible reduction. The reduction currents of two depolarizers are found to be diffusion controlled over all pressure ranges. The linear relationships between diffusion current and the concentration of two depolarizers are good agreement over all pressure ranges (1 atm∼1,800atm.).

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Eleutheroside E Content in Eleutherococcus spp. (오갈피속(屬) 식물(植物)의 Eleutheroside E 함양(含量))

  • Kim, Young-Jin;Park, Moon-Soo;Park, Ho-Ki;Kim, Sun;Sung, Chung-Ki
    • Korean Journal of Medicinal Crop Science
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    • v.4 no.4
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    • pp.333-339
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    • 1996
  • The root and stem bark of Eleutherococcus spp. is used for the treatment of paralysis, rheumatism, arthritis, diabetes, stamina failure, high blood pressure, etc. This study was con­ducted to identify botanical origins and to select standard variety of Eleutherococcus spp. with analyzing eleutheroside E content(%) of root bark and that of Eleutherococcus senticosus at different collected area, time, part and grown area. The content of eleutheroside E in the root bark was determined by HPLC, and it was 0.1925% in Eleutherococcus senticosus, 0.1103% in E. chiisanensis, 0.0348% in E. koreanum and 0.0236% in E. sieboldianum. In seasonal change of eleutheroside E content, it was higher in autumn product than summer product in Eleutherococcus senticosus. It also was higher in root bark than stem bark in different part. To investigate eleutheroside E content of root bark among different collected local area in E. sen­ticosus, it was high order to Mt. Deokyu, Hokkaido and Mt. Seolak as a 0.1625%. 0.0493% and 0.027 %, respectively. The growth of Eleutherococcus senticosus was good at grown Unbong (altitude 10m), but eleu­theroside E content was high at grown Nogodan (altitude 1, 450m).

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Implementation of PTT Change Monitoring System According to Exercise Intensity (PTT기반 운동 강도 모니터링 시스템 구현)

  • Lee, Ji-Su;Kim, Dong-Chan;Lee, Gyeong-Tack;Kim, Gyeong-Seop;Noh, Yun-Hong;Jeong, Do-Un
    • Journal of the Institute of Convergence Signal Processing
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    • v.21 no.1
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    • pp.49-54
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    • 2020
  • Cardiovascular disease is the leading cause of death worldwide and is caused by a variety of causes. The highest risk factor for cardiovascular disease is high blood pressure, which has no obvious symptoms, but if left untreated, it causes several complications. In order to treat hypertension, medication and regular exercise are required. In people with high blood pressure, excessive physical activity can put a great strain on the heart and lead to cardiovascular disease. Therefore, there is a need for an exercise intensity monitoring system through PTT measurement that can perform exercise at an appropriate intensity. In this study, we implemented a PTT change monitoring system according to exercise intensity by calculating PTT through ECG and PPG measurement. The implemented system differentiates the R-peak of the ECG and P-peak of the PPG, and calculates the PTT using the time difference between R-peak and P-peak. A running experiment was conducted to monitoring PTT change according to exercise intensity. As a result of the experiment, low intensity PTT is 0.313s, moderate is 0.220s, high is 0.188s, it was confirmed that the PTT decreased as the exercise increase increased.

Effect of Evaluation Conditions on Electrochemical Accelerated Degradation of PEMFC Polymer Membrane (PEMFC 고분자 막의 전기화학적 가속 열화에 미치는 평가조건들의 영향)

  • Sohyeong Oh;Donggeun Yoo;Suk Joo Bae;Sun Geu Chae;Kwonpil Park
    • Korean Chemical Engineering Research
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    • v.61 no.3
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    • pp.356-361
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    • 2023
  • In order to improve the durability of the proton exchange membrane fuel cell (PEMFC), it is important to accurately evaluate the durability of the polymer membrane in a short time. The test conditions for chemically accelerated durability evaluation of membranes are high voltage, high temperature, low humidity, and high gas pressure. It can be said that the protocol is developed by changing these conditions. However, the relative influence of each test condition on the degradation of the membrane has not been studied. In chemical accelerated degradation experiment of the membrane, the influence of 4 factors (conditions) was examined through the factor experiment method. The degree of degradation of the membrane after accelerated degradation was determined by measuring the hydrogen permeability and effluent fluoride ion concentration, and it was possible to determine the degradation order of the polymer membrane under 8 conditions by the difference in fluoride ion concentration. It was shown that the influence of the membrane degradation factor was in the order of voltage > temperature > oxygen pressure > humidity. It was confirmed that the degradation of the electrode catalyst had an effect on the chemical degradation of the membrane.

Effect of Supplemental Lighting of Sub-Compensation Intensities on Growth of Rosa hybrida L. 'Vital' (광보상점 이하의 보광이 절화장미 'Vital'의 생육에 미치는 영향)

  • Choi, Young-Hah;Kwon, Joon-Kook;Choi, Gyeong-Lee;Kang, Nam-Jun;Chun, Hee;Cho, Myeong-Whan;Seo, Tae-Cheol;Roh, Mi-Young;Lee, Seong-Chun;Lee, Jae-Han
    • Journal of Bio-Environment Control
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    • v.17 no.2
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    • pp.132-137
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    • 2008
  • This experiment was conducted to investigate the effect of supplemental lighting of low light intensities on growth and yield of rose 'Vital' in a forcing culture. Metal halide lamp (MH), High pressure sodium lamp (HSP), and MH+HSP were used as the light sources, and they were set up at a 310cm×450cm interval and at 120cm above the culture beds. Light intensity at 1m point distance from supplemental lighting sources was 3234μmolm2s1. Days to the 1st and 2nd harvests decreased by 58 and 35days, respectively in supplemental lighting treatment as compared to the control. Days to harvesting was the shortest in MH+HPS treatment, followed by BPS and MH, although there was no significant difference between HPS and MH treatments. The growth was better and incidence of blind shooting decreased by 57 in supplemental lighting treatments than the control, increasing marketable cut flowers. The incidence of blind shoot was the lowest in MH+BPS treatment, and there were no significant difference between MH and BPS treatments. In conclusion, supplemental lighting of low light intensities was effective in reducing days to flowering and reduced occurrence of blind shoots.

High Pressure Extraction Process of Low Quality Fresh Ginseng for Enhancing Anticancer Activities (파삼의 항암활성 증진이 가능한 고압 추출 공정)

  • Ha, Ji-Hye;Kim, Young;Jeong, Seung-Seop;Jeong, Myoung-Hoon;Jeong, Heon-Sang;Jeong, Jae-Hyun;Yu, Kwang-Wan;Lee, Hyeon-Yong
    • Korean Journal of Medicinal Crop Science
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    • v.17 no.6
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    • pp.397-406
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    • 2009
  • The low quality fresh ginseng was extracted by water at 80C and 240 bar for 20 min (HPE, High pressure extraction process). The cytotoxicity on human normal kidney cell (HEK293) and human normal lung cell (HEL299) of the extracts from HPE showed 28.43% and 21.78% lower than that from conventional water extraction at 100C in adding the maximum concentration of 1.0mg/m. The human breast carcinoma cell and lung adenocarcinoma cell growth were inhibited up to about 86%, in adding 1.0mg/m of extracts from HPE. This values were 9-12% higher than those from conventional water extraction. On in vivo experiment using ICR mice, the variation of body weight of mice group treated fresh ginseng extracts from HPE of 100 mg/kg/day concentration was very lower than control and other group. The extracts from HPE was showed longer survival times as 35.65% than that of the control group, and showed the highest tumor inhibition activities compared with other group, which were 70.64% on Sarcoma-180 solid tumor cells. On the high performance liquid chromatogram (HPLC), amount of ginsenoside-Rg2, Rg3, Rh1 and Rh2 on fresh ginseng were increased up to 43-183% by HPE, compared with conventional water extracts. These data indicate that HPE definitely plays an important role in effectively extracting ginsenoside, which could result in improving anticancer activities. It can be concluded that low quality fresh ginseng associated with this process has more biologically compound and better anticancer activities than that from normal extraction process.

A Study on Combustion Characteristics of Gasoline and Diesel Fuels in a Compression Ignition Engine (압축착화 엔진에서 가솔린과 디젤연료의 연소 특성에 관한 연구)

  • Kim, Kihyun
    • Journal of Power System Engineering
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    • v.21 no.1
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    • pp.63-69
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    • 2017
  • The combustion characteristics of gasoline and diesel were tested in a compression ignition engine. Both fuels were used with same common rail injection system. Combustion experiment showed that low load condition of 0.45 MPa IMEP (indicated mean effective pressure) was tested in metal and optical engines. The gasoline combustion showed higher hydrocarbon and carbon monoxide emissions but lower soot emission compared with diesel combustion. NOx emissions were very high at late injection timing but significantly decreased at early injection timing due to the lean combustion resulted from vigorous mixing process. Direct combustion visualization showed that the diesel combustion was dominated by diffusion combustion exhibiting soot incandescence and the gasoline combustion was mostly consisted of premixed combustion showing blue chemiluminescence.