• 아시안잔디학회지
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• 제10권1호
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• pp.61-69
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• 1996

The distribution of salt plant communities is conditioned by the gradient of salt concentration in the tidal land. The quantitative analyses of the salt vegetation were made to investigate the continuum in different stands of the tidal land in Namdong, Incheon City. The order in which the leading dominances are arranged is decided by the gradient of salt concentration. Wading dominant species, from the high level to the low level of the salt gradient, were Salicornia herbatacea, Sueda maritma, Limonium tetragonum, Aster tripolium, Atriplex tatarica, Catystegia soldonella, and Lathylus japonica These species form a continuum on the tidal land depending upon salt concentration. Key words: Continuum distribution, Salt gradient, Wading dominance.

• The Korean Journal of Ecology
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• 제21권4호
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• pp.321-328
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• 1998

To describe the major environmental factors operating in coastal wetland and to characterize the distribution of the plant species over the wetland in relation to the major environmental gradients, 12 soil physical and chemical properties were determined. The gradient of water and osmotic potential of soil, electrical conductivity, sodium and chloride content and soil texture alsong the three habitat types of salt marshes, salt swamp and sand dune were occurred. The 24 coastal plant communities from principal component analysis (PCA) on the 12 variables were at designated as a gradient for soil texture and water potential related with salinity by Axis I and as a gradient for soil moisture and total nitrogen gradient by Axis II On Axis I were divided into 3 groups (1) 9 salt marsh communities including Salicornia herbacea communities (2) 5 salt swamp communities including Scirpus fluviatilis communities and (3) 10 sand dune communities including Jmperata cylindrica communities on Axis II were divided into 2 groups (1) salt marsh and sand dune communities, and (2) 3 salt swamp communities. The results could account for the zonation of plant communities on coastal wetland observed alsong envionmental gradients.

• 태양에너지
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• 제6권2호
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• pp.15-21
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• 1986

In this study, an experimental double diffusive thermohaline system heated from below was constructed and the phenomena of each layer developed in the system were observed. The experiment was performed with the initial salt concentration gradient of $-436.2kg/m^4$ and the net heat flux of approximately $176w/m^2$. An electroconductivity-temperature probe was made and used for the measurements of salt concentration. As the result of this study, it was found that the salt concentration decreased in the bottom mixed layer and increased in the top mixed layer during the experiment while the salt concentration gradient in the diffusive layer unchanged. It was also found that the interfacial boundary layers were due largely to variations in salt concentration rather than temperature.

• Korean Journal of Chemical Engineering
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• 제35권12호
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• pp.2355-2364
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• 2018

We evaluated the effect of particle size and associated dynamics on a hydrocyclone separation process in order to understand the movement of the particle trajectories inside the hydrocyclone via numerical analysis, with particles of acid hydrolysis residues discharged in $TiO_2$ production via the sulfate method as a case study. The values obtained from the numerical simulation were successfully compared with those from experimental tests in the literature, allowing a description of the dynamics of the particles, their acting forces, and their relevant properties together with separation efficiency. The results showed that particle motion is jointly controlled by the drag force, the pressure gradient force and the centrifugal force. With increasing particle size, the influence of the drag force is weakened, whereas that of the centrifugal force and pressure gradient is strengthened. Factors including particle density, slurry viscosity, and inlet slurry flow rate also contribute to a clear and useful understanding of particle motion behavior in the hydrocyclone as a method for improving the separation efficiency.

• Membrane and Water Treatment
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• 제6권2호
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• pp.113-126
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• 2015

Salinity gradient power (SGP) systems have strong potential to generate sustainable clean electricity for 24 hours. Here, we introduce a solid-salt pressure-retarded osmosis (PRO) system using crystal salt powders rather than seawater. Solid salts have advantages such as a small storage volume, controllable solubility, high Gibbs dissolution energy, and a single type of water intake, low pretreatment costs. The power densities with 3 M draw solutions were $11W/m^2$ with exothermic energy and $8.9W/m^2$ without at 35 bar using a HTI FO membrane (water permeability $A=0.375L\;m^{-2}h^{-1}bar^{-1}$). These empirical power densities are ~13% of the theoretical value.

• 생태와환경
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• 제48권1호
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• pp.32-37
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• 2015

여러 가지 경로를 통해 유입된 귀화식물은 전국적으로 분포하며, 사구생태계에도 침입하여 자생종의 생태적 지위를 위협하고 있다. 본 연구는 해안사구에 분포하는 귀화식물의 효율적 관리 방안을 마련하기 위해 비생물적 요인인 염분스트레스가 달맞이꽃의 생장에 미치는 영향에 대한 실험을 실시하였다. 염분농도구배에 의한 발아 실험 결과 농도가 높을수록 발아율이 감소하였으며, 염분에 대한 내성범위는 160 mM까지 나타났다. 유묘기에 실시한 염분농도구배 실험에서 200 mM까지는 90% 고사하였으며, 300 mM 이상에서는 100% 고사하였다. 최초 고사일은 실험 시작 후 100 mM에서는 18.5일, 800 mM에서는 6일이었으며, 최종 고사일은 100 mM에서는 29.5일, 800 mM에서는 6일이었다. 따라서 해안사구에 분포하는 달맞이꽃의 관리 방안은 2단계 과정을 제안한다. 1단계는 발아시기 이전에 170 mM 이상의 염분을 분사하여 발아를 억제하는 방안이고 2단계는 유묘기인 6월에 달맞이꽃 잎에 600 mM 이상의 염분을 분사하여 단기간에 고사시키는 방안을 적용한다면 해안사구에 분포하는 귀화식물 관리에 효과적일 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제25권12호
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• pp.2049-2057
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• 2015

Various salt concentrations (1.0%, 1.3%, 1.6%, 1.9%, and 2.1% labeled as sample A, B, C, D, and E, respectively) were investigated for microbial diversity, identification of Lactic Acid Bacteria (LAB) in salted kimchi cabbage, prepared under laboratory conditions. These samples were stored at 4°C for 5 weeks in proper aluminum-metalized pouch packaging with calcium hydroxide gas absorber. A culture-independent method known as polymerase chain reaction - denaturing gradient gel electrophoresis was carried out to identify LAB distributions among various salt concentration samples that had identified 2 Weissella (W. confusa and W. soli), 1 Lactobacillus (Lb. sakei), and 3 Leuconostoc (Lc. mesenteroides, Lc. lactis, and Lc. gelidum) in the overall kimchi samples. The pH, titratable acidity, viable cell counts, and coliform counts were not affected by salt variations. In order to assess sensory acceptance, the conducted sensory evaluation using a 9-point hedonic scale had revealed that samples with 1.3% salt concentration (lower than the manufacturer's regular salt concentration) was more preferred, indicating that the use of 1.3% salt concentration was acceptable in normal kimchi fermentation for its quality and safety. Despite similarities in pH, titratable acidity, viable cell counts, coliform counts, and LAB distributions among the various salt concentrations of kimchi samples, the sample with 1.3% salt concentration was shown to be the most preferred, indicating that this salt concentration was suitable in kimchi production in order to reduce salt intake through kimchi consumptions.

• KSBB Journal
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• 제16권5호
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• pp.523-525
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• 2001

커들란은 용액의 pH 7.0에서 salt 상태로 존재하기 때문에 커들란만이 액상에 녹아 있는 경우에는 분리공정은 원심분리를 함으로써 분리가 가능하다. 그러나, 세포외 다당류로 생산된 커들란읜 세포, 염 의 무기물이 섞여 있기 때문에 이러한 물질을 제거하는 것이 커들란 분리의 중요한 변수가 되었다. 커들란의 생산을 위한 분리에 관한 보고는 원심분리 방법을 이용한 것으로 알려져 있음 세포 및 불순물 등을 제거하여 순수한 커들란을 분리하기 위해 pH swing separation (pH가 높은 경우 커들란이 용액에 녹는 성질을 이용)을 이용하였으나 원심분리를 수 차례 반복해야 되기 때문에 소요되는 동력이 많이 필요하여 에너지 절감형 및 오염절감형의 새로운 공정의 개발이 필요하게 되었다. 온 연구에서는 pH swing separation 에서 동력비가 많은 드는 단점을 감소시키기위하여 커들란의 물리 화학적인 특성을 고려한 분리공정을 개발하였다. 향후 공정 개선을 위한 지속적인 연구가 필요하며 완성시 경제적이 공정을 개발하는 것이 가능할 것이다.

• 전자공학회논문지CI
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• 제40권6호
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• pp.95-105
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• 2003

본 논문에서는 지문인증 시스템에서 인증 성능을 향상시키기 위한 기준점 검출 알고리즘과 특징 추출에 있어서 새로운 filterbank방법을 제안한다. 제안한 기준점 검출 알고리즘 GPM(Gradient Probabilistic Method)은 4개의 방향성분을 추출하여 방향성분을 가장 균일하게 가지는 지점을 검출하는 방법이며, 기존의 Poincare index방법과 달리 수학적 통계적 방법을 사용하기 때문에 지문의 융선에 대한 세부적이고 세밀한 전처리 과정이 불필요하며, arch형태 지문의 기준점 검출에 대한 단점을 해결한다. 또한, 제안한 filterbank방법은 기존filterbank방법에서 특징의 불균일한 분포로 생기는 단점을 균일한 분포로 만들어 추출함으로써 해결한다. 제안한 GPM의 실험결과 기존의 Poincare index방법에 비해서, 일반환경뿐 아니라 잡음환경에서의 특징 추출 시간과 인증률에서 우수함을 보여준다. 특히, 제안한 GPM은 Poincare index방법에 비해서, arch type의 지문에 대한 FAR은 일반 환경에서 49%, 밝기 잡음환경에서 39.2%, salt and pepper 잡음환경에서 15.7%의 향상을 보여준다. 또한, 기준점 검출시간에 있어서, 제안한 GPM방법은 기존의 Poincare index방법보다 0.07초의 감소를 보여주며, 특징추출 시간에 있어서도 제안한 filterbank 알고리즘은 기존의 filterbank 방법에 비해서 0.06sec의 감소를 보여준다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권7호
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• pp.364-369
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• 2004

In this Paper, a flashover prediction method using the leakage current in the contaminated EPDM distribution polymer insulator is proposed. The leakage currents on the insulator were measured simultaneously with the different salt fog application such as 25g, 50g, and 75g per liter of deionized water. Then, the measured leakage currents were enveloped and transformed as the CDFS using the Hilbert transform and the level crossing rate, respectively. The obtained CDFS having different gradients(angles) were used as a important factor for the flashover prediction of the contaminated polymer insulator. Thus, the average angle change with an identical salt fog concentration was within a range of 20 degrees, and the average angle change among the different salt fog concentrations was 5 degrees. However, it is hard to be distinguished each other because the gradient differences among the CDFS were very small. So, the new weighting value was defined and used to solve this problem. Through simulation, it Is verified that the proposed method has the capability of the flashover prediction.