칡(Pueraria thunbergiana) 조직수분관계의 일변화 특성

박용목,최창렬 한국생태학회 1998 Journal of Ecology and Environment Vol.21 No.1

The diurnal changes of the stomatal conductance, transpiration and leaf water potential were measured in order to assess the water relations characteristics of Pueraria thunbergiana in August of 1995 and 1996. The results showed two different responses depending on the duration of rainless days. The microclimatic conditions were highly stressful on 2 August. Daily maximum temperature reached to $39.0{\circ}C$ and vapor pressure deficit was 3.55 KPa. During this time the leaf water potential decreased to -1.02 MPa and a marked reduction of stomatal conductance was shown. However, on 15 August the stomatal conductance increased with increment of photon flux density, and transpiration was highly maintained during the day time. Minimum leaf water potential was only -0.47 MPa in spite of high transpiration rate. Furthermore, on 15 August reduced leaf water potential during the day time was recovered rapidly with decrease of photon flux density, whereas recovery of leaf water potential on 2 August was delayed. However, reduced leaf water potential on 2 August was recovered untile the next dawn. Osmotic potential at turgor loss point of Pueraria thunbergiana on 2, 3 and 15 August was -1.79, -1.70 and -1.60 MPa, respectively. The vapor pressure deficit is more contributive to the regulation of stomatal conductance than leaf water potential.

토양수분퍼텐셜이 복분자 습해와 토양특성에 미치는 영향

안병구(Byung-Koo Ahn),김갑철(Kab-Cheol Kim),김대향(Dae-Hyanf Kim),이진호(Jin-Ho Lee) 한국토양비료학회 2011 한국토양비료학회지 Vol.44 No.2

토양수분포텐셜이 복분자 생육에 미치는 영향을 조사하기 위하여 복분자 시설하우스에서 -5 ~-40 kPa 수준으로 토양수분을 처리하였다. 시설하우스내의 토양유효수분은 5.6%이었고, 수분포텐셜에 따라 토양수분함량이 높아지면 토양 pH와 치환성 Ca은 증가하였고, 치환성 K와 전질소 함량은 감소하였으며, 유기물함량은 수분처리 9일 이후부터 감소하였다. 수분포텐셜과 토양수분함량 간에는 y = 96.534 - 20.28In(x)의 지수함수 근사식이 성립되었다. 수분포텐셜이 -20 kPa (토양 수분 27.5%) 이상이면 복분자 잎의 엽록소 함량이 감소하였고 질소흡수가 억제되며, P 함량은 수분공급 시간에 따라 증가하였다. 수분포텐셜 -20 kPa 이상의 수준으로 7일 이상이 경과하면 뿌리활력이 급격히 감소되어 생육이 위축되었다. 지상부에 대한 뿌리비율 (T/R률)은 수분공급 9일까지 급격히 감소하였다. 휴면기의 복분자 줄기와 뿌리의 탄수화물 함량은 -5 kPa과 -10 kPa 처리구에서 가장 낮아 동해 위험도가 가장 높았다. This study was conducted to examine the impacts of different soil water potentials on environmental soil properties related to the moisture injury of Korean raspberry (Rubus coreanus Miq.). Soil water potential in the plastic film house plots was differentiated from -5 to -40 kPa. Soils in the plots contained 5.6% of plant available water. Increasing soil water contents based on the changes in water potential increased soil pH and exchangeable Ca<SUP>2+</SUP> content and decreased exchangeable K<SUP>+</SUP> and total N contents. It also declined soil organic matter content at 9 days after water treatments. Relationship between water potential and soil water content was given as an exponential equation, y = 96.534 - 20.28In(x). In particular, when the water potential was higher than -20 kPa (27.5% of soil moisture content), it decreased chlorophyll content in the raspberry leaves, inhibited N uptake by the plant, and increased phosphorus content with increasing days after water treatment. Also, as the 7 days after water treatment at higher than -20 kPa of water potential, the root activity of the plant was significantly decreased, and trunk (top)/root (T/R) ratio of the plant markedly declined until 9 days after water supply. Carbohydrate contents in the raspberry plant leaves and roots at dormant stage were the lowest at -5 and -10 kPa of water potential plots, and it may cause winter injury to the plant.

Hydrothermal energy potential near the three major metropolitan cities in Korea

Sehyeon Ham,Mungi An,Hyunjun Jung,Chang Yong Park,윤린 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.2

The potential for hydrothermal energy of the river, raw water, and reservoir water, which were located near the three major metropolitan cities in Korea, was predicted. The natural energy potential was defined by the flow rate of each water source, utilizing the temperature difference of 5 °C. Exceptionally, the amount of flow for the reservoir water was assumed to be 1 % of the dam’s storage amount for month. The technical potential for the hydrothermal energy for each water source was calculated by simulation of the whole water-source heat pump system through TRNSYS. The hydrothermal energy potential of the Han River in Seoul, Nakdong River in Busan, and Gapcheon in Daejeon are (227678, 247360, and 14600) TJ/year, respectively. In estimating the technical potential for the Han river, the average COP for the river-water heat pump system is 4.40 for cooling and 3.11 for heating, with a monthly maximum COP of 5.79, and a minimum COP of 3.01. One of the raw water pipelines in Seoul is connected in the form of the Gangbuk water purification plant-Gangbuk water intake plant. The technical hydrothermal energy potential is 5682 TJ/year. For Paldang Dam, the average COP for the reservoir water heat pump system is 3.28 for heating, and 4.26 for cooling, while the technical potential is 595 TJ/year.

국내 시판 중인 일부 탄산수의 치아 침식 가능성 평가

김상겸 ( Sang Kyeom Kim ),박석우 ( Seok Woo Park ),강시묵 ( Si Mook Kang ),권호근 ( Ho Keun Kwon ),김백일 ( Baek Il Kim ) 대한예방치과·구강보건학회 2015 大韓口腔保健學會誌 Vol.39 No.4

Objectives: The aims of this study were to determine the erosive potential of several carbonated waters and to confirm the availability of a simple ISO protocol for screening the erosive potential of drinks. Methods: A total of six carbonated waters were tested. Three products (Lemon-Sparkling water, Seagram, and Trevi) were domestic, and the other three (Perrier, San Pellegrino, and Rosbacher) were imported. Two kinds of carbonated drinks (Coca-Cola and Sprite) were used as controls. The erosive potential of each drink was assessed by measuring the initial pH (pHI), the final pH after degassing of carbon dioxide (pHF), and the titratable acidity to pH 5.5 (TA5.5) and 7.0 (TA7.0). The pH changes (ΔpH) caused by the addition of drinks to screening solutions were calculated according to the ISO protocol for evaluating the erosive potential of oral rinses. Results: The overall erosive potential of the carbonated waters was lower than that of the control drinks. The pHI and pHF of the carbonated waters ranged from 3.94 to 5.84 and from 5.07 to 7.88, respectively. The Lemon-Sparkling water showed the highest erosive potential among the carbonated waters, having the lowest pH (3.94) and the highest TA5.5 (1.67 ml). The ΔpH of all tested drinks ranged from ―1.00 to 0.23. Also, the tendency of erosive potential measured by ΔpH was similar to that measured by TA5.5. Conclusions: The carbonated waters tested in this study had a lower erosive potential than did the carbonated drinks. However, the erosive potential of domestic products was higher than that of imported products. The results of the ISO screening test could reflect the influence of the acid content as well as the pH of drinks. Therefore, this protocol could also be conveniently applied to evaluate the erosive potential of various drinks.

수목(樹木)의 수분특성(水分特性)에 관한 생리(生理)·생태학적(生態學的) 해석(解析(III) - 몇 종(種)의 침엽수(針葉樹)에 있어서 Shoot Water Potential의 일변화(日變化) 및 Xylem Conductivity의 특성(特性) -

한상섭,전두식,Han, Sang Sup,Jeon, Doo Sik 한국산림과학회 1984 한국산림과학회지 Vol.63 No.1

본(本) 연구(硏究)는 몇 종(種)의 침엽수(針葉樹)에 대하여 Shoot water potential의 일변화(日變化) 및 지(枝)의 Xylem conductivity의 특성(特性)을 측정고찰(測定考察)한 것으로 다음과 같은 결과를 얻었다. 1) Shoot water potential은 광도(光度)의 크기에 따라 변화(變化)하며, 광도(光度)의 감소(減少)가 시작된지 2시간(時間) 늦게 Shoot water potential의 증가(增加)가 시작되었다. 2) 지엽(枝葉)의 일중(日中) 최대수분(最大水分) 결차(缺差)는 12시(時)부터 14시(時) 사이에 일어나며, 그 값의 크기는 일본잎갈나무 -22 bar, 잣나무 -18 bar, 소나무 -15 bar, 젓나무 -14 bar, 리기다소나무 -10 bar 정도였다. 3) 수고(樹高) 1 m 당(當) 지엽(枝葉)의 수분결차(水分缺差)의 크기를 경사도(傾斜度)(${\varphi}_L/m$)로 나타내면 잣나무 -1.7 bar/m, 일본잎갈나무 -2.1 bar/m였다. 4) 지(枝)의 Relative Xylem conductivity (K, $cm^2/hr{\cdot}atm$)의 평균치(平均値)는 일본잎갈나무 2878, 리기다소나무 2763, 소나무 2652, 잣나무 2113 이었다. This study was to investigate the diurnal changes of shoot water potentials and the characteristics of xylem conductivity of branch in several conifers. The results obtained are as follows: 1) The diurnal shoot water potentials fluctuated with the sunlight intensities, and increase in shoot water potential lagged behind two hours as compared with the time of sunlight decrease in tree crown. 2) The shoot water potential reached the daily maximum ai twelve to fourteen o'clock in the afternoon, and the maximum shoot water potentials were -22 bar in Larix leptolepis, -18 bar in Pinus koraiensis, -15 bar in Pinus densiflora, -14 bar in Abies holophylla, and -10 in Pinus rigida. 3) The average gradient of shoot water potential per one meter height (${\varphi}_L/m$) in tree crown was -1.7 bar/m in Pinus koraiensis while that of Larix leptolepis was -2.1 bar/m. 4) The average of relative xylem conductivities (K, $cm^2/hr{\cdot}atm$) in branches was 2878 in Larix leptolepis, 2763 in Pinus rigida, 2652 in Pinus densiflora, and 2113 in Pinus koraiensis.

북한의 수력발전가능량 산정 및 평가에 대한 연구

박미리,안재현 대한토목학회 2018 대한토목학회논문집 Vol.38 No.1

This study is to analyze and evaluate water resource development potential in North Korea. The study was conducted to analyzeselected potential hydropower as an indicator to evaluate water resource development potential. Potential hydropower meanstheoretical value about the potential capacity of river. It is used to evaluate the amount of development through the hydropowergeneration. For calculating potential hydropower, monthly average and annual average of rainfall for each river basin were calculated by using the data of 27 rainfall stations in North Korea. As a result of the calculation of theoretical potential hydropower by rainfall in the seven major basins in North Korea, the Aprok River basin was analyzed to be the largest with 7,562.2×103kW. The efficiency and utilization rate of theoretical potential hydraulic power in South Korea and North Korea was 42.3% and 36.2%, respectively. The Daedong River basin's potential hydropower utilization rate is 12.3%, which is the lowest in North Korea. In the case of Daedong Riverbasin, more than 40% of the total population is inhabited, so demand for water and electricity is expected to be the largest. Therefore, the Daedong River basin is considered as a priority area for water resource development. The results of this study are expected to be used as basic data for future water resource development projects and research activities in North Korea. 본 연구에서는 북한의 수자원 개발 가능량을 분석 및 평가하였다. 이를 위해 포장수력을 수자원 개발 가능량을 평가하는 지표로 선정해서 분석하였다. 포장수력이란 하천이 보유한 잠재적인 발전 능력에 대한 이론값을 의미하며 수력발전을 통해 개발이 가능한 양을 평가하는 데 활용된다. 포장수력을 계산하기 위해, 북한의 27개 강우 관측소의 강우 데이터를 활용하여 유역별 월평균 및 연평균 강우량을 산정하였다. 이를 활용하여 북한 내 주요 7개 유역에 대해 강우에 의한 이론 포장수력을 산정한 결과, 압록강 유역이 7,562.2천kW로 가장 큰 값을 가지는 것으로 분석되었다. 남한과 북한의 이론 포장수력의 효율 및 이용률의 경우 북한의 최대 효율이 42.3%, 이용률은 36.2%로 남한보다 큰 것으로 나타났다. 북한의포장수력 이용률은 대동강 유역이 12.3%로 가장 낮았는데, 이곳은 전체인구의 40%이상이 거주하는 지역으로 장래 용수와 전력에 대한 수요가 가장 클 것으로 기대된다. 따라서 대동강유역이 수자원개발사업의 우선순위가 높은 지역일 것으로 추정되었다. 본 연구의 성과는 추후 북한 수자원 개발사업의 추진 및 관련된 연구수행에 있어 기초자료로 활용될 수 있을 것으로 기대된다.

알칼리 환원수 필터의 산화환원전위 안정화 평가

남상엽(Sangyep Nam),권윤중(Yunjung Kwon) 대한전자공학회 2016 전자공학회논문지 Vol.53 No.8

본 연구는 알칼리 환원수기에 3가지 필터(활성카본, 중공사막, 카본블럭)를 이용해서 원수를 통과시켜 통수 양에 따른 산화환원전위(Oxidation Reduction Potential) ORP값이 안정화되는 것을 평가한 것이다. 알칼리 환원수기는 환원의 기능을 가지고 있는 물을 만드는 시스템으로 인체에 유익한 미네랄과 ORP값이 일반 물에 비해 매우 낮은 값을 가지고 있는 기능수이다. 필터를 통과한 물을 전기 분해하면 물속에 있는 음이온과 양이온은 격막을 통해서 –전극 쪽에는 칼슘(Ca⁺), 칼륨(K⁺), 마그네슘(Mg⁺), 나트륨(Na⁺)을 포함한 물로 인체에 유익한 미네랄이 포함된 알칼리 환원수를 얻고 +극에는 염소(Cl),인(P),유황(S)등 -이온을 띄고 있는 유기물이 만들어 진다. 실험에서 알칼리 환원수(Alkaline Reduced Water)에서 전기분해의 전압의 크기를 조절하여 1단(pH8), 2단(pH8.5), 3단(pH9), 4단(pH9.5)으로 알칼리 환원수에 사용되고 –1단(pH6.0), -2단(pH5.0)의 산성산화수로 사용하고 있다. 이러한 시스템으로 3가지 필터에 통수하면서 ORP값이 어떻게 변화하고 어느 정도에서 안정화되는지를 평가하였고 대략 100L는 통수되어야 ORP값이 안정화하는 것을 측정하고 평가하였다. This study is about ionic water generator filter Recently, a lot of people feel deep interest in health and drinking water. Evaluation of the stability of oxidation-reduced potential (ORP) using the filter of the alkaline water. This study utilizes the three filter of activated carbon, UF, carbon block in alkaline reduced water equipment. Passing the water to the filter is evaluated that the OPR values are stability in accordance with the change of the volume in the bucket. Alkaline reduced water equipment is a system that has the function of making the water reduction. This system is the values of the human body beneficial minerals and ORP are made in the functional water has a very low value than general water. Which has passed through the filter the water in the water negative ions and positive ions through the electrolytic. After electrolysis, the cathode side by water, including Ca⁺, K⁺, Mg⁺, Na⁺ water gets Alkaline Reduced Water containing the minerals beneficial to the human body. A positive electrode side is made of the organic materials that have an anion such as chlorine (Cl), phosphorus (P), sulfur(S). This experiment uses the Alkaline Reduced Water to adjust the magnitude of the voltage of the electrolysis in the Alkaline Reduced Water. That is 1st step(pH8) 2nd step (pH8.5) 3th step (pH9), 4th step (pH9.5) in the Alkaline Reduced Water and -1st step (pH6.0), -2nd step (pH5.0) used as the acidic oxidation water. When the water passes through the three filter in this system was evaluated whether the ORP values are changed and stabilized. When about 100 liters of water passing through the filter was confirmed that the ORP values are stability and evaluation.

Estimation of Water Retention Characteristics Depending on the Particle Sizes of Perlite Using van Genuchten Equation with Retention Curve Program

Chul Soon Lim,Kyo Suk Lee,Dong Sung Lee,Hyun Gyu Jung,Beong Deuk Hong,Yoon Jeong Kim,Doug Young Chung 한국토양비료학회 2021 한국토양비료학회지 Vol.54 No.3

The estimation of water retention for perlite particles, which are used as growth media need to set up for proper water management strategy due to uncertain available water proportion during growth period of vegetable crops in a greenhouse. The water retention curves (WRC) expressed as volumetric water content (θv) were constructed with five different sizes of the expanded perlite after fully saturating and packing the perlite in open-ended metal cubes at 11 levels of matric potentials from 0 to -1,500 kPa. The best fitted four parameter values (θs, θr, n, α) of the van Genuchten model (vG model) for the substrate samples were obtained using the Retention Curve Program (RETC) based on the values measured water content at the corresponding matric potentials. The particle size corresponding to 36.8 percentage by mass of particles was 0.80065 mm. The calculated uniformity coefficient and the coefficient of gradation for the perlite were 1.962 and 2.51 mm, respectively. Measured water contents at each matric potential increased with decreasing particle size of perlite while the difference of water content between saturation (θs) and residual state (θr) increased with increasing particle size. The mean R² for all sizes of the perlite particle was suitable to predict θv because the measured data points did not vary around the estimated regression line. Therefore, PTF performance based on van Genuchten (vG) equation using data set including perlite particle size can be applicable to estimate water retention in perlite particles.

원심법에 의한 침엽수 심재부 유효수분이동경로의 반경분포 : 조재와 만재의 비교 The Difference between Earlywood and Latewood

박종수,전수경 한국목재공학회 2003 목재공학 Vol.31 No.1

원심법을 이용하여 침엽수 생재 심재부의 조재와 만재에 대한 수분이동경로의 크기를 평가하였다. 또한, 원심 처리 이후의 포수율 분포와 수분포텐셜의 관계로부터 액체투과성을 측정하였다. 삼나무의 경우, 조재는 0.70μm. 만재는 0.50μm의 반경에서 뚜렷한 피크가 관찰되었다. 솔송나무는 조재와 만재 모두 0.50μm의 반경에서 피크를 나타냈다. 일본전나무와 일본잎갈나무는 조재 0.70μm, 만재 0.30μm의 반경범위에서 피크 값이 관찰되었다. 반면에 미송과 시트카스푸르수는 뚜렷한 피크 값을 보이지 않았다. 액체투과성은 미송을 제외한 모든 수종에서 조재가 만재보다 좋게 평가되었다. The size distribution of the free water paths between earlywood and latewood for six species in the heartwood of softwoods was estimated from the amount of dehydrated free water under various centrifugal fields, such as 2,200, 3,300, 4,800 and 6,900 rpm. The centrifugal method is based on the concept that water movement occurs by the balance of centrifugal force and water potential by meniscus. Water stops where the pressure differential is zero. In the centrifugal field, only two factors affect water movement in wood, that is, centrifugal force and water potential. Also, the water permeability was evaluated from the relationship between the water saturation ratio after the centrifugal treatment and the measure of water potential in specimen. The results showed that Cryptpmeria Japonica had clear peaks at 0.70 μm in earlywood and at 0.50 μm in latewood. Tsuga sieboldii and Larix kaemferi had peaks at 0.50 and 0.30 μm in latewood. The water permeability of earlywood was higer than that of latewood for all softwoods except Pseudotsuga menziesii.

광, 온도, 수분 변화에 따른 음나무 엽의 생리반응(VII) - 기공증산, 수분이용효율, 그리고 엽육세포간극 CO₂ 농도의 일변화 -

한상섭,전두식,심주석,전성렬,Han, Sang-Sup,Jeon, Doo-Sik,Sim, Joo-Suk,Jeon, Seong-Ryeol 강원대학교 산림과학연구소 2007 Journal of Forest Science Vol.23 No.1

이 연구는 음나무의 생장에 대한 생리 생태적 특성을 측정하여 조림목의 적지환경을 구명하고자 하는 일련의 연구이다. 본 측정에서는 잎의 기공증산속도의 일변화, 수분이용효율의 일변화, 수분포텐셜의 일변화, 그리고 세포간극의 $CO_2$ 농도 일변화 등을 측정, 고찰하였다. 그 결과를 요약하면 다음과 같다. 1) 기공증산속도의 일변화는 오전 10시경이 가장 높았으며, 16시를 기점으로 기공증산속도는 빠르게 감소하였다. 2) 수분이용효율의 일변화는 오전 8시경에 최대치를 보였고, 그 후 수분포텐셜의 감소와 함께 정오까지 빠르게 감소하였다가 회복한 후 17시 이후부터는 급격한 감소를 보였다. 3) 세포간극의 $CO_2$ 농도($C_i/C_a$ 비율)의 일변화는 오전 9시까지 빠르게 감소하였고, 그 후 16시까지는 큰 변화 없이 안정한 값을 유지하였으며, 16시 이후부터는 다시 빠르게 증가하였다. $C_i/C_a$ 비율의 일변화는 수분포텐셜의 일변화와 거의 유사한 경향을 보였다. 결과적으로 산지에 식재된 음나무 잎의 기공증산, 수분이용효율, 수분포텐셜이 높은 오전에 가장 증가하고, 오후부터 급격한 감소를 나타냈다. This study was purposed to elucidate the best optimum sites by ecophysiological response measurements of Kalopanax pictus samplings of plantation. The diurnal changes of the stomatal transpiration, water use efficiency, water potential, and intercellullar $CO_2$ concentration of leaves were measured by the portable IR $CO_2$ analyzer. The results obtained are summarized as follows. 1) The daily stomatal transpiration rate was highest at 10:00 a.m. After 16:00, the stomatal transpiration rate rapidly decreased. 2) The daily water use efficiency was maximum at 8:00 a.m., and then rapidly decreased until midday with decreasing water potential. 3) The daily $C_i/C_a$ ratio rapidly decreased until 9:00 a.m., and then showed a stable value until 16:00, and then rapidly increased. The daily intercellullar $CO_2$ concentration ($C_i/C_a$ ratio) showed the same tendency as water potential changes. Consequently, stomatal transpiration and water use efficiency was increased with high water potential of leaves at am, and then remarkably decreased with low water potential at pm.