• Title/Summary/Keyword: saline water

Search Result 751, Processing Time 0.026 seconds

Growth and Yield of Rice as Affected by Saline Water Treatment at Different Growth Stages (벼 생육시기별 염수처리 농도와 기간에 따른 생육 및 수량)

  • 이충근;윤영환;신진철;이변우;김정곤
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.47 no.6
    • /
    • pp.402-408
    • /
    • 2002
  • Rice cultivar 'Janganbyeo' was cultivated by irrigating the saline waters of high salinity (3.0%) and medium saliniy (1.5%) for 4 days, and low salinity (0.5%) for 30 days at tillering, early meiosis and heading stage. Leaf injury due to salinity was most severe at tillering stage in 1999, but at heading stage in 2000. Heading date was delayed by 1 to 5 days by treatment of saline waters only at tillering stage. Culm length and panicle length were most severely shortened by treatment at early meiosis stage. Yield and yield components except for panicle number were decreased most by high salinity treatment regardless of growth stages. In particular, ripening ratio and grain weight among the yield components were decreased most conspicuously by the saline water treatment regardless of salinity and growth stage. Regarding grain weight grain-filling rate and duration, there is no remarked difference among the concentrations and treatment durations of saline water at tillering stage. However, their reductions were very different among the concentrations and treatment durations of saline water at early meiosis stage, being greatest when treated with high salinity for 4 days and followed by low salinity for 30 days. Also their reductions were very severe only when treated with high salinity for 4 days at heading stage.

Development of Time Domain Reflectometry Probe for Evaluation of Copper Concentration in Saline Environment (염수환경에서의 구리 농도 평가를 위한 Time Domain Reflectometry 프로브 개발)

  • Lee, Dongsoo;Lee, Jong-Sub;Hong, Won-Taek;Yu, Jung-Doung
    • Journal of the Korean GEO-environmental Society
    • /
    • v.19 no.3
    • /
    • pp.15-24
    • /
    • 2018
  • As electromagnetic waves are affected by electrical conductivity or permittivity, they are widely used to evaluate geotechnical characteristics. In this study, a probe for measuring electromagnetic waves using a time domain reflectometry is manufactured to evaluate heavy metal concentration in saline water. In the experiments, a copper is used as a heavy metal, and a probe is demonstrated with the concentration of copper. Solutions were set for 8 different copper concentration (0, 0.01, 0.05, 0.1, 0.5, 1, 5, 10 mg/L) in saline water with 3% salinity. The probe is coated by electrical insulating materials such as epoxy, top-coat, varnish, acrylic paint, heat-shrinkage tube to measure electromagnetic waves in saline water. The measured signals are compared according to coating material. As results, for probes coated with acrylic paint and heat-shrinkage tube, signal variation is not detected. For epoxy, top-coat, and varnish coated probes, the voltage decreases with an increase of copper concentration. Probes coated by epoxy at once and top coat can estimate under 5 mg/L of copper concentration and the probe coated by epoxy twice can estimate over 5 mg/L of copper concentration. This study shows that the probe using the time domain reflectometry can be used to evaluate the concentration of heavy metal in saline water by coating the probe with insulating material.

Effect of Blood Contamination on Vickers Microhardness and Surface Morphology of Mineral Trioxide Aggregate

  • Jaehyun Seung;Seong-Jin Shin;Byounghwa Kim;Ji-Myung Bae;Jiyoung Ra
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.51 no.2
    • /
    • pp.165-175
    • /
    • 2024
  • This study aimed to investigate the effects of blood contamination on the Vickers hardness and the surface morphology of premixed MTA and compare them with the effects on conventional MTA. The Vickers microhardness of Endocem MTA Premixed Regular (EP) and ProRoot MTA (PM) was assessed after immersion in fetal bovine serum (FBS) and saline. Stem cells from human exfoliated deciduous teeth (SHED) were seeded on MTA after immersion in FBS, saline, and deionized water (DW). Cell adhesion patterns and surface morphology were visualized via scanning electron microscopy (SEM). The surface microhardness of EP and PM in FBS was lower than in saline. However, short-term exposure of PM to FBS did not reduce the microhardness compared to saline. Angular crystals formed in water, while rounded crystals with more air voids appeared in FBS. Favorable SHED attachment occurred in all groups. Overall, the surface hardness of EP and PM decreased after FBS exposure, although PM was less influenced. We suggest minimizing the amount of bleeding when using MTA clinically; nevertheless, PM remains an option with more expected blood contamination than EP. In summary, exposure to FBS decreased mechanical performance but allowed cell adhesion for both MTAs, with PM being more resistant to these changes.

Sulfonated poly(arylene ether copolymer)-g-sulfonated Polystyrene Membrane Prepared Via E-beam Irradiation and Their Saline Water Electrolysis Application (전자빔조사를 이용한 술폰화 폴리아릴렌 에테르 술폰-g-술폰화 폴리스틸렌 분리막 제조 및 염수전기분해 특성평가)

  • Cha, Woo Ju;Lee, Chang Hyun
    • Membrane Journal
    • /
    • v.26 no.6
    • /
    • pp.458-462
    • /
    • 2016
  • Saline water electrolysis, known as chlor-alkali (CA) membrane process, is an electrochemical process to generate valued chemicals such as chlorine, hydrogen and sodium hydroxide with high purities higher than 99%, using an electrolytic cell composed of cation exchange membrane, anode and cathode. It is necessary to reduce energy consumption per a unit chemical production. This issue can be solved by decreasing intrinsic resistance of the membrane and the electrodes and/or by reducing their interfacial resistance. In this study, the electron radiation grafting of a $Na^+$ ion-selective polymer was conducted onto a hydrocarbon sulfonated ionomer membrane with high chemical resistance. This approach was effective in improving electrochemical efficiency via the synergistic effect of relatively fast $Na^+$ ion conduction and reduced interfacial resistance.

Geophysical and Geochemical Studies for the Saline Water Intrusion under the Paddy Field in Kyoung-gi area, Korea (경기 지역 농경지 하부로의 해수 침투에 관한 지구물리 및 지구화학적 연구)

  • Lee Sang-Ho;Kim Kyoung-Woong;Lee Sang-Kyu
    • Geophysics and Geophysical Exploration
    • /
    • v.2 no.2
    • /
    • pp.96-103
    • /
    • 1999
  • Most of saline water inousions have been diagnosed by geophysical or geochemical approach independently. The objective of this study is to provide the effective method to detect the saline water intrusion on the ground water in the vicinity of seashore using these two methods. Schulumberger sounding, frequency domain electromagnetic sounding and geochemical analysis of ground water were carried out to explore saline water intrusion. Schulumberger sounding was implemented in dry surface condition before irrigation water was introduced into the field, while electromagnetic sounding was carried out in wet ground condition after the irrigation. The purpose of duplicated measurements on the equivalent spot at different times was to investigate the variation of anomaly zone depending on the amount of ground water. It was possible to discriminate the anomalous zone due to high water saturation from the low electric resistivity zone by high salt concentrations through this way. For the verification of the geophysical result, the ground water samples in the study area were collected and analysed at the 23 points near the measuring spots. The groundwater at the spot nearest to the sea water intrusion identified by geophysical method indicates higher salinity than the standard limit concentration for agricultural irrigation water (250 mg/1). Isotope analysis of $D({^2}H)$ vs. is ${^18}O$ and PCA analysis were used to discriminate the anthropogenic pollution from those of high salinity from sea water intrusion.

  • PDF

A Study on the Characteristics of Saline Groundwater and Its Well Development in the Western Coastal Area of Jeju Island (제주 서부 해안 지역 염지하수 특성 및 관정 개발에 관한 연구)

  • Cho, Eun-Il;Ko, Tak-Kyun;Lee, Min-Gyu;Kam, Sang-Kyu
    • Journal of Environmental Science International
    • /
    • v.27 no.8
    • /
    • pp.677-688
    • /
    • 2018
  • The purpose of this study was to minimize salt water intrusion into freshwater aquifers and limit the development of freshwater aquifers, by selecting an appropriate excavation depth of in the western coastal area of Jeju Island. The study site was mostly basaltic lava, which was mainly composed of trachy basalt. A vertical logging test was conducted to investigate the vertical distribution of the groundwater and saline groundwater interface in the study well. It was found that freshwater groundwater, saline groundwater, and freshwater groundwater are distributed from the surface to approximately 16 m, 16~50 m, and 50~60 m, below the ground, respectively. In order obtain saline groundwater and minimize the inflow of freshwater into this well, the drilling depth should be limited in the range of 16~50 m from the surface. Thus, saline groundwater well development should be carried out with reference to the measurement results, which depend on the drilling depth and EC (electrical conductivity) obtained with drilling apparatus for geology and ground handling.

Can Exogenous Betaine Be an Effective Osmolyte in Broiler Chicks under Water Salinity Stress?

  • Honarbakhsh, Shirin;Zaghari, Mojtaba;Shivazad, Mahmood
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.20 no.11
    • /
    • pp.1729-1737
    • /
    • 2007
  • A CRD experiment was conducted to evaluate the effects of different exogenous betaine levels (0.000, 0.075, 0.150 and 0.225 percent) on 576 one-day-old male broiler chicks (Ross) under water salinity stress. Different levels of water salinity were made by adding 3 levels of NaCl (0, 1,000 and 2,000 mg/L) to drinking water. Feed and water were available ad libitum. Betaine increased body weight, improved feed conversion ratio, and decreased packed cell volume (p<0.05). Water salinity promoted body weight over the whole period, increased feed intake (11 to 21 and 29 to 42-d) and also improved feed conversion ratio in grower and finisher periods (p<0.01). Breast weight, water consumption (28-d and 42-d) and excreta moisture (28-d) were increased by elevating the level of water salinity (p<0.01). Interaction between dietary betaine and water salinity was significant on plasma osmolarity as well as epithelial osmolarity of the duodenum at 28-d. Epithelial osmolarity was decreased from duodenum to ileum. The data imply that betaine is involved in the protection of intestinal epithelia against osmotic disturbance which can be caused by saline water, but further research is needed to investigate the effects of betaine with higher levels of water salinity.

Interfacial and Mechanical Properties of Glass Fiber Reinforced Epoxy Composites with Different Crosslinking Density after Saline Water Aging (기지재의 가교밀도에 따른 유리섬유 복합재료의 염수노화 후 계면 및 기계적 물성)

  • Shin, Pyeong-Su;Kim, Jong-Hyun;Baek, Yeong-Min;Park, Ha-Seung;Kwon, Dong-Jun;Park, Joung-Man
    • Composites Research
    • /
    • v.31 no.5
    • /
    • pp.186-191
    • /
    • 2018
  • Condition and properties of composites with different chemical structure of epoxy matrix were observed after saline solution treatment. Epoxy was used as matrix and the flexibility was controlled by using 2 typed-epoxies and 3 types hardeners (amine, acid anhydride and amide). Saline water treatment was conducted with 6 wt% NaCl solution at $60^{\circ}C$ for 0, 15, and 30 days. Cross section was observed and interfacial and mechanical and properties was evaluated. Amine type exhibited the highest crosslinking density and mechanical and interfacial properties whereas water absorbance was lowest. It is because that the water molecules can be hardly penetrate into the epoxy matrix or the interface between epoxy and glass fiber and it leads to saline water resistance of composites.

Low temperature and Salt Tolerances of Native Zoysiagrass (Zoysia spp.) Collected in South Korea (국내 자생 한국잔디류의 내한성 및 내염성 조사)

  • Choi, Joon-Soo;Yang, Geun-Mo
    • Asian Journal of Turfgrass Science
    • /
    • v.25 no.2
    • /
    • pp.138-146
    • /
    • 2011
  • This study was carried out to select salt tolerant zoysiagrass breeding lines. Eighty two native zoysiagrasses collected from S. Korea were used in this study. Saline water were prepared by mixing sea water and tap water. ECw levels of saline water treated ranged from 2 to $3dS{\cdot}m^{-1}$. Zoysiagrass planted in pot by sprigging were soaked into the plastic box containing saline water. Winter injury was investigated under the pot condition. Most of Z. japonica types did not show winter injury. But Z. tenuifolia type, Z. matrella type, and Z. sinica type showed winter injury under the pot condition at Cheonan area. NaCl level in soil was increased from 0% to 0.51% by treatment of saline water. Soil ECe measurement showed upto $170dS{\cdot}m^{-1}$. Z. tenuifolia type (Z5034), Z. matrella type ('Konhee', Z4109, 'Semill'), Z. japonica type (Z1055, Z1040, Z1008, 'Zenith', 'Millock') and medium leaf type zoysiagrass (Z6096, Z6118, Z6021, Z6074) resulted in below 30% leaf firing under the saline condition. This approach might be useful for selecting salt tolerant breeding lines.