• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.111-120
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• 2006

Opening size of 3 types of geotextile were tested using dry and wet sieving methods to evaluate characteristics of test methods and to compare the test results. Judging from test results, dry sieving method is a poor test, having many problems causing many errors but a simple-quick test. Wet sieving method is a very specific test avoiding many of the problems of dry sieving such as electrostatic charges, trapping in the geotextiles and so on. However, one of wet sieving tests, KSK ISO12956, takes long time to complete a test and is too strict to handle loss of granular material. Generally, opening size of a geotextile by wet sieving test is smaller than that of dry sieving test. Especially, opening size by KSF 2126 which is one of wet sieving test but disused at present anymore is similar or smaller than that by KSK ISO12956 method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.103-104
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• 2023

In this study, the correlation between the rheolog y parameter of fresh concrete and the rheology parameter of wet sieving mortar was analyzed for analyzing to possibility predicting the rheology parameter of fresh concrete. Through the experiment, the dynamic yield stress and plastic viscosity of concrete and wet sieving mortar show a direct proportional relationship, and the two data had a correlation. Therefore, it is thought that it is possible to predict the rheology parameter of fresh concrete through the rheology parameter of wet sieving mortar. However, in order to more accurately predict the rheology parameter of fresh concrete, it is need additional relationship analysis by collecting more rheology parameter data of fresh concrete and wet sieving mortar.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.10C
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• pp.614-620
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• 2011

RSA, the most commonly used public-key cryptosystem, is based on the difficulty of factoring very large integers. The fastest known factoring algorithm is the Number Field Sieve(NFS). NFS first chooses two polynomials having common root modulo N and consists of the following four major steps; 1. Polynomial Selection 2. Sieving 3. Matrix 4. Square Root, of which the most time consuming step is the Sieving step. However, in recent years, the importance of the Polynomial Selection step has been studied widely, because one can save a lot of time and memory in sieving and matrix step if one chooses optimal polynomial for NFS. One of the ideal ways of choosing sieving polynomial is to choose two polynomials with same degree. Montgomery proposed the method of selecting two (nonlinear) quadratic sieving polynomials. We proposed two cubic polynomials using 5-term geometric progression.

• Journal of the Korean GEO-environmental Society
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• v.11 no.5
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• pp.15-23
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• 2010

Dry sieving, wet sieving and photoscattering analyzer were tested as particle size analyzing methods for sediments from rivers and lakes of Han river, Nakdong river, Youngsan river, and Kumgang river area. Dry sieving showed a big error due to coagulating effect over drying process and this phenomena was severe for lake sediment. Wet sieving and PSA showed an accurate results though wet sieving needs more labor and complicate processes. Freeze-dry or freeze-dry after oxidation of organics with hydrogen peroxide showed improved results but gave lower portion of fine particles in comparing with wet sieving. Heavy metal contents and extractable metal contents were investigated for the sediments and high heavy metal content and extractable amount were obtained from fine particles as expected. Using of proper particle size analyzing method is important and the sediment management should be focused on the fine particles.

• Membrane Journal
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• v.7 no.1
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• pp.15-21
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• 1997

Carbon molecular sieve (CMS) membranes were synthesized by the pyrolysis of polymeric precursors. The CMS materials had oxygen-nitrogen selectivities much higher than those observed for the polymeric precursors. Typically molecular sieving materials have diffusion selectivities much higher than polymeric materials. This has been identified as a result of higher entropic selectivity of the molecular sieving materials. A study of the development of molecular sieving properties as the polymeric precursor is pyrolyzed into a CMS material will offer us an insight into polymeric molecular structures needed for enhanced entropic selectivity membrane materials.

• Journal of fish pathology
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• v.23 no.3
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• pp.303-311
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• 2010

Our previous finding summarizing that larval sieving process is inevitable but triggers the outbreak of scutica-like ciliates (SLCs) in the seed production of Patinopecten yessoensis urged further study to determine best suggestable sieving interval in an agreeable range of water quality. In the mass seed production of the scallop, SLC outbreak was closely related to the larval sieving in which larvae were drained on the basis of every 3-day (5T), 5-day (3T), 7-day (2T), or 9-day (1T) from culture tanks onto a mesh screen and placed back into new water in cleaned tanks. The larval performance of growth and survival was clearly dependent on the sieving intervals. It was in order of 3T, 5T, 2T, and 1T for both of growth and survival and in reverse order for SLC infection frequency, confirming that larval sieving is necessary but damageable if it overwhelms the larval resistance. Interestingly, the larval damages by the sieving persisted to their ensuing spat life in terms of nursery growth, survival, and abnormality.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.12
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• pp.1965-1974
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• 2020

Objective: This study consisted of two stages; the first was to determine the effect of extrusion and sieving treatments on the chemical properties of palm kernel cake (PKC), and accordingly, a follow-up experiment (second stage) was conducted to determine and compare the apparent metabolizable energy (AME), and protein and amino acid digestibility of extruded and sieved PKC. Methods: Two physical treatments, namely extrusion (using temperature profiles of 90℃/100℃/100℃, 90℃/100℃/110℃, and 90℃/100℃/120℃) and sieving (to 8 particles sizes ranging from >8.00 to 0.15 mm) were carried out to determine their effects on chemical properties, primarily crude protein (CP) and fiber contents of PKC. Based on the results from the above study, PKC that extruded with temperature profile 90/100/110℃ and of sieved size between 1.5 to 0.15 mm (which made up of near 60% of total samples) were used to determine treatments effect on AME and CP and amino acid digestibility. The second stage experiment was conducted using 64 male Cobb 500 chickens randomly assigned to 16 cages (4 cages [or replicates] per treatment) to the following four dietary groups: i) basal (control) diet, ii) basal diet containing 20% untreated PKC, iii) basal diet containing 20% extruded PKC (EPKC), and iv) basal diet containing 20% sieved PKC (SPKC). Results: Extrusion and sieving had no effect on CP and ash contents of PKC, however, both treatments reduced (p<0.05) crude fiber by 21% and 19%, respectively. Overall, extrusion and sieving reduced content of most of the amino acids except for aspartate, glutamate, alanine and lysine which increased, while serine, cysteine and tryptophan remained unchanged. Extrusion resulted in 6% increase (p<0.05) in AME and enhanced CP digestibility (p<0.05) by 32%, as compared to the untreated PKC while sieving had no effect on AME but improved CP digestibility by 39% which was not significantly different from that by extrusion. Conclusion: Extrusion is more effective than sieving and serves as a practical method to enhance AME and digestibility of CP and several amino acids in broiler chickens.

• Carbon letters
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• v.8 no.1
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• pp.12-16
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• 2007

Molecular sieving carbon (MSC) for separating $O_2-N_2$ and $CO_2-CH_4$ has been prepared through chemical vapor deposition (CVD) of methane and benzene on activated carbon spheres (ACS) derived from polystyrene sulfonate beads. The validity of the material for assessment of molecular sieving behavior for $O_2-N_2$ and $CO_2-CH_4$ pair of gases was assessed by the kinetic adsorption of the corresponding gases at $25^{\circ}C$. It was observed that methane cracking on ACS lead to deposition of carbon mostly in whole length of pores rather than in pore entrance, resulting in a reduction in adsorption capacity. MSC showing good selectivity for $CO_2-CH_4$ and $O_2-N_2$ separation was obtained through benzene cracking on ACS with benzene entrantment of $0.40{\times}10^{-4}\;g/ml$ at cracking temperature of $725^{\circ}C$ for a period of 90 minutes resulting in a selectivity of 3.31:1.00 for $O_2-N_2$ and 8.00:1.00 for $CO_2-CH_4$ pair of gases respectively.

• Korean Journal of Materials Research
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• v.31 no.8
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• pp.465-470
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• 2021

Deuterium is a crucial clean energy source required for nuclear fusion and is a future resource needed in various industries and scientific fields. However, it is not easy to enrich deuterium because the proportion of deuterium in the hydrogen mixture is scarce, at approximately 0.016 %. Furthermore, the physical and chemical properties of the hydrogen mixture and deuterium are very similar. Therefore, the efficient separation of deuterium from hydrogen mixtures is often a significant challenge when using modern separation technologies. Recently, to effectively separate deuterium, studies utilizing the 'Kinetic Quantum Sieving Effect (KQS)' of porous materials are increasing. Therefore, in this review, two different strategies have been discussed for improving KQS efficiency for hydrogen isotope separation performance using nanoporous materials. One is the gating effect, which precisely controls the aperture locally by adjusting the temperature and pressure. The second is the breathing phenomenon, utilizing the volume change of the structure from closed system to open system. It has been reported that efficient hydrogen isotope separation is possible using these two methods, and each of these effects is described in detail in this review. In addition, a specific-isotope responsive system (e.g., 2nd breathing effect in MIL-53) has recently been discovered and is described here as well.

• Bulletin of the Korean Chemical Society
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• v.30 no.2
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• pp.297-301
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• 2009

We have developed the yttrium oxide (YNP) or ytterbium oxide (YbNP) nanoparticle/polymer matrices for the size-dependent separation of DNA ranging from 100 bp to 9,000 bp. High separation efficiency (> $10^6$ plates/m) and the baseline resolution for various DNA standards (100 bp, 500 bp, and 1 kbp DNA ladder) were obtained in 10 min with these matrices. The effects of concentrations of both polyethylene oxide (PEO) and nanoparticles were investigated and the highest performance was obtained at 0.02% PEO with 0.02% YNP or YbNP. Similar sieving power for both YNP and YbNP matrices was observed probably due to the similar sizes of nanoparticles, resulting in the formation of comparable sieving networks for DNA separation. For the reduction of electrosmotic flow, either dynamic or permanent coating of the capillary inner wall was compared and it turned out that PEO was superior to polyvinylpyrrolidone (PVP) or polyacrylamide (PAA) for better separation efficiency.