• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.1-11
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• 1998

The generally accepted idea for carbohydrate translocation in plants is an osmotic pressure flow hypothesis. According to the hypothesis, a high concentration of carbohydrate in the phloem of carbohydrate synthesis regions (source) causes a water influx into the phloem. The generated osmotic potential in the phloem is responsible for long distance carbohydrate transport through the positive hydrostatic pressure. In regions of carbohydrate utilization and storage (sink), translocated carbohydrates are continuously metabolized and compartmentalized, generating a concentration gradient between source and sinks. In this system, carbohydrates load into the phloem (phloem loading) and unload out of the phloem (phloem unloading). Phloem-mobile herbicides that are applied to plants are also translocated from the source to sinks. However, some experimental results reveal that the patterns of phloem translocation between carbohydrates and herbicides are different. The differences are due, in part, to the physico-chemical properties of herbicides and to the absence/presence of specific carrier(s) in the phloem.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.311-312
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• 2023

In this study, porous concrete with improved functionality was developed by using superabsorbent polymer (SAP) to provide rooting space for plants. The depth of settlement and mass change according to the substitution and addition rate of SAP were determined by investigating the functional performance of SAP and the volume change upon saturation. Test results indicated the depth of penetration settlement increased as the substitution rate of SAP increased, but the mass change could not be confirmed as the addition rate of SAP increased. The instability of the specimens due to the excessive volume change of SAP, as well as the osmotic pressure phenomenon according to the pH concentration, were identified as the cause. Therefore, future studies are needed to investigate the appropriate substitution and addition rate of SAP, as well as to reduce the osmotic pressure phenomenon according to the pH concentration, which would contribute to the improvement of the functional performance of vegetation concrete.

• Korean Journal of Organic Agriculture
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• v.24 no.2
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• pp.273-287
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• 2016

Accumulation of excessive salt in Reclaimed coastal tidelands can reduce crop yields, reduce the effectiveness of irrigation, degradation of soil structure, and affect other soil properties. These salts has shown to cause specific ions in the plant over a period of time leads to ion toxicity or ion imbalance and a continuous osmotic phase that prevents water uptake by plants due to osmotic pressure of saline soil solution. This review focuses on the characteristics of salt-affected soils, mechanisms of salt-tolerance plants, desalinization technology, and soil management to maintain sustainable agro-ecosystem in salt-affected soils.

• Mycobiology
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• v.47 no.4
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• pp.483-493
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• 2019

Antrodia cinnamomea is a unique medicinal fungus in Taiwan. It has been found rich in some pharmacologically active compounds for anti-cancer, hangover, and immune regulation etc. With the in-depth study of these components, it would be interesting and important to establish a molecular system for basic studies of A. cinnamomea. Thus, we would like to set up a foundation for this purpose by studying the A. cinnamomea protoplast preparation and regeneration. Firstly, we studied the optimization method of protoplast preparation of A. cinnamomea, and found various factors that may affect the yield during protoplast preparation, such as mycelial ages, pH values, and osmotic stabilizers. Secondly, in the regeneration of protoplasts, we explored the effects of various conditions on the regeneration of protoplasts, including different media and osmotic pressure. In addition, we found that citrate buffer with pH value around 3 dramatically increased the regeneration of protoplasts of A. cinnamomea, and provided a set of regeneration methodology for A. cinnamomea.

• Journal of Forest and Environmental Science
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• v.27 no.1
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• pp.33-37
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• 2011

This study was carried out to establish a proper cultivation site and diagnose the drought-tolerance of Allium ochotense leaves and Allium microdictyon leaves by using pressure - volume curve method. The Allium microdictyon leaves had more lower osmotic water potential ${\psi}osat$, and osmotic water potential at turgor loss point ${\psi}otlp$ than Allium ochotense leaves. Then, the Allium microdictyon leaves was slightly higher drought-tolerance than Allium ochotense leaves. Therefore, We suggest that growth of the two Allium species was appropriate for relative moisture forest.

• Geomechanics and Engineering
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• v.17 no.1
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• pp.69-79
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• 2019

This work presents an experimental study of the hydromechanical behavior of a natural swelling soil taken from Boumagueur region east of Algeria. Several pathological cases due to the soil shrinkage / swelling phenomenon were detected in this area. In a first part, the hydric behavior on drying-wetting paths was made, using the osmotic technics and saturated salts solutions to control suction. In The second part, using a new osmotic oedometer, the coupled behavior as a function of applied stresses and suction was investigated. It was shown that soil compressibility parameters was influenced by suction variations that an increase in suction is followed by a decrease in the virgin compression slope. On the other hand, the unloading slope of the oedometric curves was not obviously affected by the imposed suction. The decrease in suction strongly influences the apparent preconsolidation pressure, ie during swelling of the samples after wetting.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.11
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• pp.791-802
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• 2014

Energy shortage is being exacerbated due to the increase of energy consumption and depletion of fossil fuels. In order to release the energy crisis, new types of energy resources such as small hydropower, solar power, wind power and biomass have been already developed or actively researched. Recently, osmotic power, which harvests energy from salinity gradient between seawater and fresh water, is considered as a feasible candidate. Among the osmotic power processes, pressure retarded osmosis (PRO) is widely gaining attention because of no emission of carbon dioxide and less sensitivity to the external environmental conditions. However, PRO process is facing difficulties such as the lack of specialized PRO membrane and optimization technologies. Therefore, PRO was reviewed in this paper in terms of theoretical background, membrane development, process development and fouling mechanism to provide insights and suggest the future direction of PRO research.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.4
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• pp.285-292
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• 2021

Osmotic power is to produce electric power by using the chemical potential of two flows with the difference of salinity. Water permeates through a semipermeable membrane from a low concentration feed solution to a high concentration draw solution due to osmotic pressure. In a pressure retarded osmosis (PRO) process, river water and wastewater are commonly used as low salinity feed solution, whereas seawater and brine from the SWRO plant are employed as draw solution. During the PRO process using wastewater effluent as feed solution, PRO membrane fouling is usually caused by the convective or diffusive transport of PRO which is the most critical step of PRO membrane in order to prevent membrane fouling. The main objective of this study is to assess the PRO membrane fouling reduction by pretreatment to remove organic matter using coagulation-UF membrane process. The experimental results obtained from the pretreatment test showed that the optimum ferric chloride and PAC dosage for removal of organic matter applied for the coagulation and adsorption process was 50 mg/L as FeCl₃ (optimum pH 5.5). Coagulation-UF pretreatment process was higher removal efficiency of organic matter, as also resulting in the substantial improvement of water flux of PRO membrane.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.4
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• pp.379-383
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• 2011

Electro-osmotic pumps were fabricated by using two types of porous glass frits. The performance of these pumps was characterized in terms of maximum flow rate, current, and pressure using deionized water and 1 mM sodium tertraborate decahydrate buffer. Maximum flow rate and current when ROBU porous glass frits were used were higher than those when DURAN porous glass frits were used because of the high porosity of the ROBU glass frits. However, the maximum pressure when ROBU glass frits were used was similar to that when DURAN glass frits were used. The therrmodynamic efficiency of a pump with ROBU porous glass frits is approximately twice that of a pump with DURAN porous glass frits. Further, the maximum flow rate at maximum current in the case of ROBU porous glass frits is high. However, it is lower than the maximum pressure at maximum current in the case of DURAN porous glass frits. Further, in this study, we also verified the effectiveness of ROBU glass frits when high flow rate is required and of DURAN glass frits when a high pressure is required.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.506-515
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• 2003

Six barley varieties that showed different degree of drought tolerance were grown with and without drought stress treatment (control), and investigated for the temporal changes in growth and several physiological traits after drought treatment. Soil water potential was -0.05 ㎫ at the initial stage of drought treatment and dropped to -0.29 ㎫ at 19 days after withholding irrigation. Soil water potential (SWP) maintained at -0.05 ㎫ in the control. The dry weight (DW) under the drought treatment were reduced compared to the control as follows: Dicktoo-S (short awn), 69% ; Dicktoo-L (long awn), 70%; Dicktoo-T (tetra), 86%; Dongbori-1, 69%; Suwonssalbori-365, 55% and Tapgolbori, ,37%. Dicktoo lines and Dongbori-1 were more tolerant than Suwonssalbori-365 and Tapgolbori. Leaf relative water contents (RWC) and leaf water potential (LWP) decreased obviously under the drought condition, the decrease being greater especially in the less drought-tolerant barley genotypes. Dongbori-1 and Dicktoo-L in drought treatment showed net photosynthesis of 38% and 17% compared to the control, respectively, and the other four genotypes much lower photosynthesis of 1.1% to 7.0%. Stomatal conductance, mesophyll conductance, and the photochemical efficiency (Fv/Fm) of PS II were reduced by drought treatment, the reduction being greater in drought-sensitive genotypes. The drought-tolerant genotypes had greater osmotic adjustment (OA) capacity under water stress. Thus, the decrease of RWC and LWP was lower and the turgor pressure conservation capacity was higher under water stress in drought-tolerant genotypes. Drought-tolerant genotypes showed less decrease of photosynthesis because stomatal conductance, mesophyll conductance and the ratio (Fv/Fm) of the variable to maximal fluorescence of drought-resistant genotype was decreased less in the drought stress condition. In conclusion, the drought-tolerant genotypes had better water conservation capacity through efficient OA, and this led to the lower decrease of photosynthesis and growth in water stress condition.