• Title/Summary/Keyword: PA66

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Effect of Irrigation Starting Point of Soil on Chlorophyll Fluorescence, Stem Sap Flux Relative Rate and Leaf Temperature of Cucumber in Greenhouse (시설 토양 오이재배에서 관수개시점 처리가 광합성 형광반응, 줄기수액흐름 및 엽온에 미치는 영향)

  • An, Jin Hee;Jeon, Sang Ho;Choi, Eun Yong;Kang, Ho Min;Na, Jong Kuk;Choi, Ki Young
    • Journal of Bio-Environment Control
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    • v.30 no.1
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    • pp.46-55
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    • 2021
  • This experiment was conducted to investigate the effect on chlorophyll fluorescence, stem sap flux relative rate (SFRR) and leaf temperature of cucumber when irrigation is controlled using a soil moisture tensiometer. Cucumber (Cucumis sativus L.) 'Chungchun' was irrigated of 10-10-20 kPa and 20-10-10 kPa by soil starting point of irrigation at each growth stage. At the 66 days after treatment (DAT) of 736 to 854 W·m-2 and above 32℃, chlorophyll fluorescence variables (Fo, Fm, Fv/Fm) values showed significantly different between treatments. The Fo and Fv/Fm value in the daytime (10:30 am to 6:00 pm) at 66 DAT was higher in 20-10-10 kPa treatment than in 10-10-20 kPa treatment. The Fv/Fm value decreased when the leaf temperature was increased. There was no difference in leaf growth (length, width and area) at 28 and 66 DAT, but the chlorophyll content (SPAD value) was significantly higher in 20-10-10kPa treatment. SFRR and leaf temperature increased with light intensity and temperature increased. In both treatments, the SFRR started to increase sharply between 8 am and 9 am when the solar radiation is 170 W·m-2 or higher. The soil temperature of the treatments decreased after irrigation, that showed 31.0℃ at 10-10-20kPa and 28.5℃ at 20-10-10kPa on July 5 (820W·m-2 at 1 pm). However, there was no difference in SFRR, leaf temperature, temperature difference (leaf temperature - air temperature) and VPD between treatments. SFRR was significantly positive correlate with the leaf temperature (p < 0.01, r = 0.770). The SFRR and leaf temperature showed positive significant correlation with solar radiation, temperature, soil temperature, soil moisture content and VPD. There was a negative significant correlation with relative humidity and temperature difference.

The Study of Pressure Vacuum Measurement Techniques Using Ultrasonic Acoustic Impedance Transducers (초음파 음향임피던스 변환기를 이용한 저압 저진공 측정기술 연구)

  • Hong, S.S.;Shin, Y.H.;Cho, S.H.;Ahn, B.Y.;Lim, J.Y.;Choi, I.M.
    • Journal of the Korean Vacuum Society
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    • v.19 no.5
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    • pp.319-325
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    • 2010
  • Pressure vacuum measurement technique using acoustic impedance change of ultrasonic transducers was studied. The sensor has been setup using two air-coupled ultrasonic transducers, one as a transmitter and the other as a receiver, and put it into vacuum chamber and measured pressure versus ultrasonic amplitude. The result confirms that the standard deviations of four repeat measurements were from 0.0093 to 0.3325 at pressure 6.66 kPa to 202.65 kPa(about two atmosphere), and the relative percents were 0.018% and 0.164% at pressure 133.32 kPa and 202.65 kPa, respectively.

Pnatothenic Acid Satus in Pups and Dams Fed Pantothenic Acid Deficient Diet during Gestation (임신기간동안의 Pantothenic Acid 결핍식이가 어미쥐 및 새끼쥐의 Pantothenic Acid 대사에 미치는 영향)

  • 송요숙
    • Journal of Nutrition and Health
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    • v.29 no.2
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    • pp.206-212
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    • 1996
  • This study was to see if pregnant rats fed a pantothenic acid(PA) deficient diet for whole 3 weeks gestation would produce pups comparable to the normal controls, at the cost of maternal tissue PA concentration ([PA]) or coenzyme A content ([Co A]). Compared to the controls, dams fed a PA deficient diet tended to decrease weight gain, and produced pups with lower body, liver and brain weight (p<0.05). Postpartum dam's blood [PA] decreased more in PA deficient group than control (p<0.05, PA deficient : 2.52$\pm$0.66 to 0.77$\pm$0.23uM, control : 2.58$\pm$0.52 to 1.45$\pm$0.68uM), although Hb concentration did not differ between two groups. Pup's blood [PA] at birth was lower in PA deficient group than control group(1.75$\pm$0.27uM vs. 3.90$\pm$0.76uM, respectively, p<0.05) and 2-3 times that of postpartum dams in both two groups. [Co A] and [PA] in pup's tissues were 23-68% of dams in both groups, in spite of the higher [PA] in pups. These data suggest that Co A metabolism differs between pups and dams ; the pups were more adversely affected than dams by the dietary PA deficiency of dams during gestation.

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Study on the Assessment of the Criteria on a Door Closer for the Optimum Design of the Access Door of a Smoke Control Zone (제연구역 출입문의 최적 설계를 위한 도어클로저의 기준 산정에 관한 연구)

  • Lee, Jae-Ou;Choi, Chung-Seog
    • Fire Science and Engineering
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    • v.27 no.3
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    • pp.66-71
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    • 2013
  • The purpose of this study is to assess the criteria on a floor hinge and door closer for the optimum design of the access door of a smoke control room. The door opening force due to differential pressure is 60.75 N, 40.5 N, 32.91 N and 12.66 N when the differential pressure is 60 Pa, 40 Pa, 32.5 Pa and 12.5 Pa, respectively. The door opening force of the floor hinge and door closer to which the criteria of KS F 2806 are applied is 27.5 N, 40 N, 75 N, 100 N and 125 N for the Nos. 1, 2, 3, 4 and 5 class floor hinges and door closers, respectively. This study compared the differential pressure and opening force limits of floor hinges and door closers with the values specified in NFSC 501A and found that they exceeded the criteria specified in NFSC 501A. Therefore, it is necessary to reflect the differential pressure and smoke control wind speeds as well as the opening forces specified in NFSC 501A on the design of floor hinges and door closers. The installation conditions of floor hinges and door closers of access doors differ depending on the type and name of a smoke control damper. This study found that Nos. 1, 2 and 3 floor hinges and door closers could be installed for access doors with low differential pressure and that Nos. 1 and 2 floor hinges and door closers could be installed for access doors with normal differential pressure.

A Study for Quality of Stabilization of Ball-Seat - I (볼시트 품질 안정화에 관한 연구 - I)

  • 김인관;최준영;김대식;정영득;김영수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.350-353
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    • 2001
  • Due to the widen demand of plastic part in automobiles, more accurate numerical simulation works are needed to find optimum molding process like filling fiber orientation pressure control. Therefore, C-mold software was applied for the simulation of injection molding process and cooling process in this research. The purpose of this study is developing a ball seat which made by injection process with PA66 resin and it is applied to the automobile suspension system. It must secure low friction, wear resistance and dimensional accuracy. Specially this study aims to get the quality stabilization of injection molded bass-seat parts.

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Development of a cavity pressure measuring device and estimation of viscosity functions of various polymer composites (사출성형 금형 캐비티 내압 측정장치 개발 및 이를 이용한 새로운 복합재료의 점도 측정)

  • Kim, Yong-Hyeon;Kim, Dong-Hak
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.1
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    • pp.877-887
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    • 2015
  • We have proposed a new method for estimating the viscosity of the composite. In this paper, we have developed a device for measuring the injection mold cavity pressure. This makes it possible to verify the accuracy of the viscosity in CAE D/B in real time by measuring the melt pressure in the mold, and comparing this with the simulated pressure from the CAE analysis. Materials used in this study is a PP(Polypropylene), PP/LGF30%(Polypropylene/long glass fiber 50% composite) and PA66/LGF50%(Polyamide 6,6/long glass fiber 50% composite). The viscosity data for PP and PP long fiber composite have already been built, but the one for PA66 long-fiber composite does not exist because it is a newly developed material. Thus we obtained the viscosity curve of PA66/LGF50% by this system. Then, the viscosity curves from conventional viscometer were also compared with the viscosity obtained by the our method. And, we proved the accuracy of the CAE data of PP. In case of PP/LGF50% which is highly viscous and complex material, we improved the existing CAE data.because there was a difference between the measuring data and the CAE data.

Multimode fiber-optic pressure sensor based on dielectric diaphragm (유전체 다이아프램을 이용한 다모드 광섬유 압력센서)

  • 김명규;권대혁;김진섭;박재희;이정희;손병기
    • Journal of the Korean Vacuum Society
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    • v.6 no.3
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    • pp.220-226
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    • 1997
  • An optical intensity-type pressure sensor has been fabricated by coupling multimode optical fiber with 100 nm-Au/30 nm-NiCr/150 nm-$Si_3N_4/300 nm-SiO_2/150 nm-Si_3N_4$ optical reflection layer supported by micromachined frame-shape silicon substrate, and its characteristics was investigated. For the application of $Si_3N_4/SiO_2/Si_3N_4$ diaphragm to the optical reflection layer of the sensor, NiCr and Au films were deposited on the backside of the diaphragm by thermal evaporation , respectively, and thus optical low caused by transmission in the reflection layer could be decreased to a few percents. Dielectric diaphragms with uniform thickness were able to be also reproduced because top- and bottom-$Si_3N_4$ layer of the diaphragm could automatically stop silicon anisotropic etching. The respective pressure ranges in which the sensor showed linear optical output power-pressure characteristics were 0~126.64 kPa, 0~79. 98 kPa, and 0~46.66 kPa, and the respective pressure sensitivities of the sensor were about 20.69 nW/kPa, 26.70 nW/kPa, and 39.33 nW/kPa, for the diaphragm sizes of 3$\times$3 $\textrm{mm}^2$, 4$\times$4 $\textrm{mm}^2$, and 5$\times$5 $\textrm{mm}^2$, indicating that the sensitivity increases as diaphragm size increases.

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A CFD Analysis on DPF for the Removal of PM from the Emission of Diesel Vehicle (디젤차량 배기가스의 PM 제거에 관한 매연여과장치 전산해석)

  • Yeom, Gyuin;Han, Danbee;Nam, Seungha;Baek, Youngsoon
    • Clean Technology
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    • v.24 no.4
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    • pp.301-306
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    • 2018
  • Recently, due to the increase in the fine dust, regulations on PM generated from diesel cars are strengthened. There is a growing interest in diesel particulate filters (DPFs), a post-treatment device that removes exhaust gases from diesel vehicles. Therefore, one of the enhancements of the DPF efficiency is to reduce the pressure drop in the DPF, thereby increasing the efficiency of the filter and regeneration. In this study, the effect of cell density, channel shape, wall thickness, and inlet channel ratio of 5.66" SiC and Cordierite DPF on the pressure drop in DPF was investigated using ANSYS FLUENT simulator. As a result of the experiment, the pressure drop was smaller at 300 CPSI than 200 CPSI, and the anisotropy and O / S cell showed less than Isotropy by pressure drop of about 1,000 Pa. As the porosity increased by 10% the pressure drop was reduced by about 300 Pa and as the wall thickness increased by 0.05 mm, the pressure drop was increased by about 500 Pa.

Effects of Lumbar Central Posteroanterior Mobilization on Isometric Knee Extension and Patellar Tendon Reflex Amplitude: A Pilot Study

  • Kim, Bo Kyung;An, Ho Jung;Heo, Seo Yoon;Kim, Byeong Jo;Choi, Wan Suk
    • Journal of International Academy of Physical Therapy Research
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    • v.9 no.1
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    • pp.1435-1441
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    • 2018
  • The main focus of this study was to investigate effects of lumbar central posteroanterior (PA) mobilization on isometric knee extension (IKE) ability and patellar tendon reflex amplitude (PTRA) in healthy university students. University students aged 19-26 (male; 10, female; 10) without any neurological disorders participated voluntarily and excluded the subjects with abnormal reflexes. The participation had an average body mass of $64.25{\pm}13.52kg$, an average height of $1.66{\pm}0.08m$, and an average Body Mass Index (BMI) of $23.07{\pm}3.21$. Every student was randomly assigned to be received squatting exercise and PA mobilization sequentially with 5 days of wash out period. IKE and PTRA were not significantly different between the two groups after the intervention. All the outcome measures were arranged into two data groups; PA mobilization and squatting exercise data group. In the PA mobilization data group, IKE and PTRA significantly increased after the intervention, however, these aspects were decreased in the squatting exercise group. These findings suggest that IKE and PTRA increase immediately after PA mobilization, therefore PA mobilization could be a valuable topic for controlled clinical trials.