• Journal of Korean Society on Water Environment
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• v.21 no.6
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• pp.637-642
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• 2005

The focus of this study was to examine the phosphorus removal characteristic by zirconium mesoporous structured material synthesized on various conditions. The zirconium sulfate-surfactant mesoporous structured material(ZS) was synthesized by hydro-thermal synthesis. The material has regular hexagonal array of surfactant micelles and sulfate ion ($HSO_4{^-}$). We confirmed that sulfate ion in zirconium mesoporous structured material can be ion-exchanged with phosphate ion ($H_2PO_4{^-}$) in phosphoric acid solution. On the X-ray diffraction (XRD) pattern of ZS, three peaks which shows the important characteristics of hexagonal crystal lattice were observed at (100), (110) and (200). The transmission electron micrograph (TEM) show high crystallization with pore size about $47{\AA}$. The maximum adsorption capacity of ZS was as great as 3.2 mmol-P/g-ZS. From the adsorption isotherm, correlation coefficients were higher for the Langmuir isotherm than the Freundlich isotherm. With the respect of chain length of surfactant, the adsorption capacity for phosphate synthesized with C12 was higher than C16 and C18. The highest amount of adsorbed phosphate on ZS was observed at the surfactant-to-zirconium molar ratio of 0.5 to 1.

• Journal of Technologic Dentistry
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• v.38 no.3
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• pp.193-199
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• 2016

Purpose: The purpose of this study was to know of photopolymerization effect of self-etch dual-cured resin cement on different transmittance and thickness of zirconia disks. Methods: The two types of transparent and opaque zirconia speciments were prepared. The five speciments of each groups were seperated with 0.5mm and 1.0mm thickness. Degree of conversion(DC) were studied by FT-IR spectroscopy using ATR method before and after irradidaion for 40 sec. Results: The relative DC was showed the higher results of ZS5 as compared with ZS10 (p < 0.05). And OP5 and OP10 were lower results than ZS10 (p < 0.05). Conclusion: The photopolymerization effect of dual-cured resin cement were affected by the transmittance and thickness of zirconia.

• Advances in concrete construction
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• v.9 no.5
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• pp.449-457
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• 2020

The influence of subsequent curing on the performance of fly ash contained mortar under steam curing was studied. Mortar samples incorporated with different content (0%, 20%, 50% and 70%) of Class F fly ash under five typical subsequent curing conditions, including standard curing (ZS), water curing(ZW) under 25℃, oven-dry curing (ZD) under 60℃, frozen curing (ZF) under -10℃, and nature curing (ZN) exposed to outdoor environment were implemented. The unsteady chloride diffusion coefficient was measured by rapid chloride migration test (RCM) to analyze the influence of subsequent curing condition on the resistance to chloride penetration of fly ash contained mortar under steam curing. The compressive strength was measured to analyze the mechanical properties. Furthermore, the open porosity, mercury intrusion porosimetry (MIP), x-ray diffraction (XRD) and thermogravimetric analysis (TGA) were examined to investigate the pore characteristics and phase composition of mortar. The results indicate that the resistance to chloride ingress and compressive strength of steam-cured mortar decline with the increase of fly ash incorporated, regardless of the subsequent curing condition. Compared to ZS, ZD and ZF lead to poor resistance to chloride penetration, while ZW and ZN show better performance. Interestingly, under different fly ash contents, the declining order of compressive strength remains ZS>ZW>ZN>ZD>ZF. When the fly ash content is blow 50%, the open porosity grows with increase of fly ash, regardless of the curing conditions are diverse. However, if the replacement amount of fly ash exceeds a certain high proportion (70%), the value of open porosity tends to decrease. Moreover, the main phase composition of the mortar hydration products is similar under different curing conditions, but the declining order of the C-S-H gels and ettringite content is ZS>ZD>ZF. The addition of fly ash could increase the amount of harmless pores at early age.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.3
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• pp.267-273
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• 2016

This study evaluated the mechanical properties and crack-healing abilities of zirconia composite ceramics. The six kinds of specimens used were: partially stabilized zirconia (Z) and five zirconia composite (ZS, ZST1, ZST2, ZST3, and ZST5) with SiC and $TiO_2$. There was not a large difference between the Vickers hardness of the six types of zirconia ceramics. The bending strength of the ZS specimen degraded rapidly, but the zirconia specimens with $TiO_2$ (ZST1, ZST2, ZST3, and ZST5) showed improved strength. Therefore, it was determined that the bending strength is affected by the crystallization, which is due to the addition of SiC and $TiO_2$. From the crack-healing conditions having the highest bending strength, monolithic zirconia retained its cracks, while the specimens of four types with SiC healed their cracks.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1753-1759
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• 2009

The present study was conducted to investigate the effects of components obtained from Zanthoxylum schinifolium and Zanthoxylum piperitum on rancidity and quality of Kwamegi (semi-dried Pacific saury, Coloabis saira). Ethanol extract (ZS) of Zanthoxylum schinifolium leaves or the essential oil (ZP) obtained from pericarp of Zanthoxylum piperitum in 1 or 20% ethanol solution was sprayed to the Pacific saury before Kwamegi preparation at its final concentrations of 0.125~2 ppm in the Kwamegi. The prepared Kwamegi was vacuum packed with multi-layered film (polyethylene/polyamide/EVOH/polyethylene, thickness 80 μm) and kept at -20${^{\circ}C}$ until use. After opening the package Kwamegi was stored at 4${^{\circ}C}$ for 1, 3 and 7 days during which rancidity tests and sensory evaluation were carried out. Acid, peroxide, and thiobarbituric acid (TBA) values increased with storage time but reduced significantly by the addition of ZS at the concentrations of ≥G0.125 ppm and ZP≥F0.25 ppm. The effects of ZS and ZP were dose-dependent and more pronounced as storage time prolonged. The ZS and ZP also reduced dimethyamine and trimethyamine (TMA) contents which were increased with time, while they prevented the decrease of trimethyamine oxide. The ZS at the concentration of ≥G0.25 ppm and the ZP at >0.5 ppm were needed to maintain TMA less than 4.5 mg/100 g for 3 day storage at 4${^{\circ}C}$. Sensory evaluation of the Kwamegi exhibited a slightly higher preference with the ZS and ZP treated ones at the level of 0.25~0.5 ppm. It is concluded that very low amounts of ZS and ZP are effective in suppression of rancidity of Kwamegi and could be utilized for its quality management.

• Clinical and Experimental Pediatrics
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• v.51 no.8
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• pp.842-847
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• 2008

Purpose : Measurement of forced expiratory volume in 1 second ($FEV_1$) is usually difficult to obtain in children under six years of age because it requires active cooperation. This study evaluates the sensitivity of impulse oscillometry system (IOS) parameters for detecting airway obstruction in comparison with $FEV_1$. Methods : We studied 174 children who performed the lung function and methacholine challenge tests to diagnose asthma by IOS and spirometry. Children were divided into two subgroups according to their $PC_{20}$, which is a parameter for bronchial sensitivity. We compared IOS parameters with $FEV_1$ at the baseline, post-methacholine challenge, and evaluated their correlation. Results : At the baseline, reactance at 5 Hz (X5) and resistance at 5 Hz (R5) significantly differed between the $PC_{20}$ positive ($PC_{20}{\leq}16mg/mL$) group and $PC_{20}$ negative ($PC_{20}$ >16 mg/mL) group; however, $FEV_1$, $FEV_1$ % predicted, $FEV_1_-Zs$ (Z score) did not differ. $FEV_1$ is correlated with X5 (r=0.45, P<0.01) and R5 (r=-0.69, P<0.01). $FEV_1_-Zs$ is also correlated with X5_Zs (r=-0.26, P<0.01) and R5_Zs (r=-0.31, P<0.01). After the methacholine challenge test, dose-response slopes in $FEV_1$ and X5 significantly differed between the two subgroups (P<0.05). Conclusion : IOS parameters were more discriminative than $FEV_1$ for detecting decreased baseline lung function between two subgroups and have a good correlation with $FEV_1$.

• The Plant Pathology Journal
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• v.25 no.3
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• pp.286-290
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• 2009

The stability of three different kinds of pUC-derived plasmids, pDsRed, pZsYellow, and pGFPuv, was investigated in Pectobacterium strains to utilize those plasmids as tracers. All three plasmids pDsRed, pZsYellow and pGFPuv showed their specific colors in Pectobacterium strains. Especially, the plasmid pDsRed conferred bright pink colonies on the Pectobacterium strains. When the bacteria lost the plasmid pDsRed, the colonies turned white, suggesting that the plasmid could be a good marker system for Pectobacterium strains on different environmental conditions. The effect of the antibiotic pressure on the stability of the plasmid was different depending on the host bacteria. P. carotovorum subsp. betavasculorum was more sensitive to the antibiotic pressure than P. carotovorum subsp. carotovorum Pcc21. However, temperature change significantly affected plasmid stability on both Pectobacterium strains. Almost all strains lost the plasmids with the shift in temperature from $28^{\circ}C$ to $37^{\circ}C$. Presence of the plasmids did not affect bacterial pathogenicity on their own host plants. Among three plasmids, pZsYellow was not useful as a marker because the yellow fluorescent proteins from pZs Yellow were interfered with the yellow natural fluorescence of the plant tissues induced by the defense system. Since the red color of DsRed can be seen with naked eyes, plasmid pDsRed was applicable as a marker. However, the color change was slow so that additional manipulation to increase the expression speed was necessary. Plasmid pGFPuv could serve as a perfect marker without any problem, tracing the reproduction and spread of the plant pathogens perfectly.

• Korean Journal of Medicinal Crop Science
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• v.19 no.1
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• pp.1-8
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• 2011

Biological characteristics of 5 Zanthoxylum schinifolium (Zs) fruits such as Z1 (early August), Z2 (middle August), Z3 (middle September), Z4 (early October) and Z5 (middle October) according to harvesting time were evaluated. As fruits ripened, average weight of Zs increased from 4.8mg (Z1) to 50.7mg (Z5), while moisture contents decreased from 74.6% (Z1) to 55.2% (Z5). Crude fat contents of the fruits during ripening increased from 1% (Z1) to 10.6% (Z5). The major fatty acids in Zs were palmitic (C16:0), palmitoleic (C16:1), oleic (C18:1), and linoleic (C18:2) acids. Linoleic acid (C18:2) was a main fatty acid in Z1 and Z2, whereas oleic acid (C18:1) was found as a main one in the other Zs. The ratio of unsaturated fatty acid to total fatty acids increased from 60% (Z1) to 80% (Z3~Z5) during ripening. Among ripening stages, Z4 had the highest contents of total fatty acids ($3,355{\mu}g/g$) and total unsaturated fatty acids ($2,753{\mu}g/g$). Forty six volatile compounds in Zs were also identified. The major volatile compounds were ${\alpha}-pinene$, ${\beta}-myrcene$, ${\beta}-ocimene$, 2-nonanone, estragole, 2-undecanone, and ${\beta}-caryophyllene$. Major volatile components of Z1 were ${\beta}-ocimene$ (20.8 peak area %) and ${\alpha}-pinene$ (9.7 peak area %). In Z2, estragole (30.1 peak area %) was a main volatile compound, but the contents of ${\alpha}-pinene$ (0.4 peak area %), ${\beta}-myrcene$ (0.3 peak area %), and ${\beta}-ocimene$ (0.6 peak area %) were lower than those in Z1. Especially, estragole used as perfumes and as a food additive for flavor was drastically increased to 91.2 (Z3) and 92% (Z4) as fruits ripened.

• Journal of Forest and Environmental Science
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• v.39 no.1
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• pp.20-26
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• 2023

Cow pea (Vigna unguiculata) was intercropped with Ziziphus spina-christi as summer forage in two consecutive seasons of 2017 and 2018. The aims to find out suitable agroforestry practice for saline soils of Khartoum State. And to investigate effect of tree spacing on forage biomass yield under semi -irrigated systems. Completely randomized block design with 3 replicates was conducted for this trial. Thus Z.spina-christi that fixed at 4×4 m was intercropped with cowpea at 1 m and 1.5 m spacing from trees trunk. Tree growth parameters were measured in terms of tree height, tree collar diameter, tree crown diameter and fruit yield per tree. While crop were parameters were determined in terms of plant height, number of plant, forage biomass yield per ha and land equivalent ratio. Soil profile of 1×1 m and 1.5 m depth was excavated and its features were described beside its chemical and physical properties were analyzed for 0-10 cm, 0-30 cm, and 30-60 cm and 60-100 cm layers. The results revealed that soil pH, CaCO₃, SAR, ESP, and EC ds/m were increased by increasing soil depths. Meanwhile tree growth in terms of tree height was significant in the first season 2017 when compared with tree collar diameter and tree crown diameter. Also significant differences were recorded for tree growth when compared with sole trees in the second season in 2018. Tree fruit showed marked variations between the two seasons, but it was higher under intercropping particularly at ZS2. Crop plant height was highly significant under sole cropping than intercropping in first season in 2017. In contrast forage biomass yield was significant under intercropping in ZS1 and ZS2 treatments. Land equivalent ratio was advantageous under this agroforestry system particularly under ZS2. Thus it recorded 5 and 9 for ZS2 in the two consecutive seasons respectively. Therefore, it is feasible to introduce this agroforestry system under such arid lands to provide summer forage yield of highly nutritive value and low cost for animals feed as well as to increase farmers' income and to halt desertification and to sequester carbon.

• Carbon letters
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• v.10 no.2
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• pp.109-113
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• 2009

Various silanes, amino silane, vinyl silane, TESPD, and ZS (TESPD/zinc soap complex), are added into chlorinated isobutylene-isoprene copolymer (CIIR)/soft clay/carbon black (CB). The vulcanization characteristics, the processability, and the mechanical properties are measured. In soft clay/CB filled CIIR system, there are no significant changes in Mooney viscosity among compounds. Vinyl silane added compound shows a low extrusion torque. All the silane added compounds shows an increased modulus. The mechanical properties are significantly increased when the S2 is added into CIIR/soft clay/CB compounds.