• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.4
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• pp.267-273
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• 1977

Rainbow trout were reared in a small indoor aquarium which was equipped with a simple recirculating biofilter combined with a small amount of inflowing water for 199 days from April 25 to November 10, 1977 in Busan where very hot summer air temperature is encountered, and results obtained were promissing as following; 1. The aquarium has dimensions of $1m\;\times\;1m\;\times\;67cm(depth)$, and a bottom center sedimentation chamber of conical type through which out-flowing water is pushing fecal matter and other detritus outward. The conical sedimentation chamber measures 20 cm depth and 20 cm diameter at its upper mouth and tapers to the bottom end which is connected to 4 cm diameter draining pipe. The draining pipe goes through under the tank and then is elevated on the side. The water depth was maintained at about 40 cm depth by adjusting the heigh of draining pipe. The filter bed contained 16 l of $3\~5\;mm$ zeolite gravels, and water circulation rate was about 1030 l/hr. 2. Continuous inflowing water resulted in a good elimination of waste materials through its outflowing water thus reducing waste loading in the filter. 3. Mean temperature of water in the rearing aquarium containing about 400 l water volume was maintained at around 20 to $22^{\circ}C$ by 0.59 l/min of the inflowing well water which usually maintained the temperature of $17^{\circ}C$ during the hot summer season from the first of July to the first of October when the 10-days-mean air temperature ranged from $20^{\circ}\;to\;27.3^{\circ}C$ $(total\;mean\;24.6^{\circ}C) $ and under this condition the fish continued normal growth. 4. The production per 1 l/min of inflowing water with this simple biofilteration reached 30 hg. 5. The total cost including all feed and power during this experimental rearing period fell well within the economic establishment and if the feed and filteration system are improved the benefit-cost ratio will be much increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1381-1384
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• 2004

In order to help the preservation of the cherry tomatoes, antimicrobial paper incorporating grapefruit seed extract and zeolite was applied to packaging fruits. The fruits were packed with a paper bag of 15.5${\times}$24 cm and then stored at 1$0^{\circ}C$. During the storage, weight loss, pH, total acidity, soluble solid content, microbial load and decay were measured as quality indices. Steady weight loss due to the transpiration was observed to slightly increase the solid content during the storage with little difference between the packaging treatments. There were little change in pH and acidity of the stored fruits. The microbial loads of total aerobic bacteria, and yeast/mold counts were significantly suppressed during 10 day storage by the antimicrobial paper packaging, which also contributed to reducing the decayed fruits observed after 15 days.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.3
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• pp.227-234
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• 2006

Two candidate glasses, AG8W1 and DG-2, have been developed for vitrifying the mixture of low activity resin, zeolite and Dry Active Waste(DAW), and DAW solely, respectively. In order to evaluate the chemical durability of the glasses, two different leaching tests, Product Consistency Test(PCT) and Vapor Hydration Test(VHT), have been performed. As the results of PCT performed from 7 to 120 days, the leach rates of B, Na, Si and Li in the glasses were much lower than those of the benchmark glass(SRL-EA). As the result of VHT peformed for 7 days, the leach rates were 2 and $10g/m^2/day$ for AG8W1 and DG-2, respectively, The results of VHT met the regulatory guideline( $<50g/m^2/day$) for the low activity glasses of Hanford in the USA. Consequently, two candidate glasses to be used at a commercial operation in the future showed that their chemical durability is satisfactory according to the results of two leaching tests.

• Food Science and Preservation
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• v.13 no.3
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• pp.273-278
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• 2006

In order to help the preservation of the cherry tomato and unshiu orange, antimicrobial paper incorporating grapefruit seed extract and zeolite was applied to the package. Cherry tomato and unshiu orange were packed in a box (38x25x20 cm) attached with antimicrobial paper and then stored respectively at $5^{\circ}C$. During the storage, weight loss, pH total acidity, soluble solid content microbial load and decay ratio were measured as quality indices. pH increase in cherry tomato was observed until 20 days, and decreased with litle difference between the packaging treatments thereafter pH and total acidity decrease in unshiu orange were shown till 30 days, and abrupt change was revealed by 40 days. This was due to physiological disorders. The microbial loads of total aerobic bacteria, and yeast/mold count were suppressed during storage by the box packaging incorporated with antimicrobial agents, which also contributed to reducing the decayed cherry tomato and unshiu orange. Antimicrobial paper was useful fur the reduction of microbial load in cherry tomato and unshiu orange pear without other quality deterioration.

• Journal of the Mineralogical Society of Korea
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• v.23 no.4
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• pp.377-393
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• 2010

Pumiceous tuffs occurring in the Beomgockri Group are examined applied-mineralogical characteristics and their controling factors to evaluate their potentials as the adsorption-functional mineral resources. The pumiceous tuffs are diagenetically altered to low-grade zeolitcs and bentonites in the Janggi area. Compositional specialty due to the presence of pumice fragments induces the altered tuffs to exhibit the characteristic adsorption property combined with cation exchange capacity, specific surface area, and acidic pH. Unusual lower pH in the adsorption-functional mineral substances is turned out to be originated from the presence of H-smectite having $H^+$ in the interlayer site of the sheet structure. On account of disordered crystallinity resulting from the exchanged $H^+$ in the interlayer site, the smectite commonly forms crenulated edges in the planar crystal form and exhibits characteristic X-ray diffraction patterns showing comparatively lower intensities of basal spacings including (001) peak than conventional Ca-smectite. Based on the interpretation of paragenetic relations and precursor of the H-smectite, a genetic model of the peculiar clay mineral was proposed. The smectite formation may be facilitated resulting from the precipitation of opal-CT at decreasing pH condition caused by the release of H+ during diagenetic alteration of pumice fragments. Because of the acidic smectite, the low-grade mineral resources from the Beomgockri Group may be applicable to the adsorption industry as the raw materials of acid clays and bed-soil.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.265-271
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• 2004

A feeding trial was conducted to investigate the influence of feeding Lactobacillus reuteri culture (LR) on productive performance, intestinal microflora and availability in laying hens. Four hundred and eighty, Isa-Brown layers, 49 weeks of age, were fed diets supplemented with LR at the level of 0 (control), 0.1, 0.2, and $0.4\%$ of the diets for eight weeks. Egg production and egg weight were measured daily. Feed intake was weighed every two weeks. Egg quality was measured three times at the start, mid-term, and end of the experiment. Intestinal microflora were examined for Lactobacillus spp., E. coli and Salmonella at the end of the experiment. Overall egg production was the highest in $0.2\%$ LR (P<0.05), but that of $0.1\%$ or $0.4\%$ LR treatments did not significantly differ from that of control. Egg weight was significantly higher in LR feeding group than the control (P<0.05). Daily egg mass was significantly higher in $0.2\%$ and $0.4\%$ LR treatments compared to the control and $0.1\%$ LR (P<0.05). The number of jumbo and extra large eggs were increased in LR supplemented groups, especially in $0.1\%$ LR. Feed intake of layers fed LR supplemented diets tended to be lower than the control. However, feed conversion ratio significantly improved in LR supplemented groups (P<0.05). Availability of dry matter and crude protein improved significantly in $0.4\%$ LR treatment (P<0.05). But, those of ether extract and crude ash were not significantly different among treatments. Eggshell breaking strength and eggshell thickness were not significantly influenced by LR supplementation, and Haugh unit and yolk index were also similar to the control. Total number of Lactobacillus spp. in ileum and cecum fed LR supplemented diets were significantly higher than those of the control (P<0.05). There were no significant differences in intestinal E. coli and Salmonella in all treatments. Therefore, it is concluded that dietary supplementation of Lactobacillus reuteri culture can improve the laying performance, feed efficiency and intestinal Lactobacillus.

• Journal of the Korean Chemical Society
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• v.40 no.6
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• pp.427-435
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• 1996

The structures of fully dehydrated $Ca^{2+}$- and $Cs^+$-exchanged zeolite X, $Ca_{35}Cs_{22}Si_{100}Al_{92}O_{384}$($Ca_{35}Cs_{22}$-X; a=25.071(1) $\AA)$ and $Ca_{29}Cs_{34}Si_{100}Al_{92}O_{384}$($Ca_{29}Cs_{34}$-X; a=24.949(1) $\AA)$, have been determined by single-crystal X-ray diffraction methods in the cubic space group Fd3 at $21(1)^{\circ}C.$ Their structures were refined to the final error indices $R_1$=0.051 and $R_2$=0.044 with 322 reflections for $Ca_{35}Cs_{22}$-X, and $R_1$=0.058 and $R_2$=0.055 with 260 reflections for $Ca_{29}Cs_{34}$-X; $I>3\sigma(I).$ In both structures, $Ca^{2+}$ and $Cs^+$ ions are located at five different crystallographic sites. In dehydrated $Ca_{35}Cs_{22}$-X, sixteen $Ca^{2+}$ ions fill site I, at the centers of the double 6-rings(Ca-O=2.41(1) $\AA$ and $O-Ca-O=93.4(3)^{\circ}).$ Another nineteen $Ca^{2+}$ ions occupy site II (Ca-O=2.29(1) $\AA$, O-Ca-O=118.7(4)') and ten $Cs^+$ ions occupy site II opposite single six-rings in the supercage; each is $1.95\AA$ from the plane of three oxygens (Cs-O=2.99(1) and $O-Cs-O=82.3(3)^{\circ}).$ About three $Cs^+$ ions are found at site II', 2.27 $\AA$ into sodalite cavity from their three-oxygen plane (Cs-O=3.23(1) $\AA$ and $O-Cs-O=75.2(3)^{\circ}).$ The remaining nine $Cs^+$ ions are statistically distributed over site Ⅲ, a 48-fold equipoint in the supercages on twofold axes (Cs-O=3.25(1) $\AA$ and Cs-O=3.49(1) $\AA).$ In dehydrated $Ca_{29}Cs_{34}$-X, sixteen $Ca^{2+}$ ions fill site I(Ca-O=2.38(1) $\AA$ and $O-Ca-O=94.1(4)^{\circ})$ and thirteen $Ca^{2+}$ ions occupy site II (Ca-O=2.32(2) $\AA$, $O-Ca-O=119.7(6)^{\circ}).$ Another twelve $Cs^+$ ions occupy site II; each is $1.93\AA$ from the plane of three oxygens (Cs-O=3.02(1) and $O-Cs-O=83.1(4)^{\circ})$ and seven $Cs^+$ ions occupy site II'; each is $2.22\AA$ into sodalite cavity from their three-oxygen plane (Cs-O=3.21(2) and $O-Cs-O=77.2(4)^{\circ}).$ The remaining sixteen $Cs^+$ ions are found at III site in the supercage (Cs-O=3.11(1) $\AA$ and Cs-O=3.46(2) $\AA).$ It appears that $Ca^{2+}$ ions prefer sites I and II in that order, and that $Cs^+$ ions occupy the remaining sites, except that they are too large to be stable at site I.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.367-376
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• 2022

This study is a preliminary step to understand the reaction between various liquids and zeolite in the subduction zone environment. Stilbite, NaCa₄(Al₉Si₂₇)O₇₂·28(H₂O), was selected and high pressure study was conducted on compressional behavior by the pressure-transmitting medium (PTM). Water and NaHCO₃ solution that can exist in the subduction zone was used as PTM, and samples were pressurized from ambient to a maximum of 2.5 GPa. Below 1.0 GPa, both experiments show a low linear compressibility in the range of 0.001 to 0.004 GPa^-1 and a high bulk modulus of 220(1) GPa. This is presumably because the structure of the stilbite becomes very dense due to insertion of water molecules or cations into the channel. On the other hand, at 1.0 GPa or higher, the trends of the two experiments are different. In the water run, the linear compressibility of the c-axis is increased to 0.006(1) GPa^-1. In the NaHCO₃ run, the linear compressibility of the b- and c-axis is increased to 0.006(1) GPa^-1. The bulk modulus after 1.0 GPa shows values of 40(1) and 52(7) GPa in water and NaHCO₃ run, respectively, confirming that stilbite becomes more compressible than that before 1.0 GPa. It is caused by the migration of cations and water molecules inside the channel, as the water molecules in the PTM start to freeze and stop to insert toward the channel at 1.0 GPa or more. In the NaHCO₃ run, it is assumed that the distribution of extra-framework species inside the structure is changed by substitution of the Na⁺ cation. It can be expected from tendency of the relative intensity ratio of the (001) and (020) peaks which show a different from that of the water run.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1079-1085
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• 2003

Modified atmosphere packaging was applied to oyster mushrooms (Pleurotus ostreatus) to study the effect of storage temperatures and packaging materialso. Whole mushrooms (200g) were package with polyethylene film $(PE,\;60{\mu}m\;thickness)$, ethylene vinyl acetate (EVA), or ceramic film (containing 5% zeolite) and stored at 0, 5, 10 and $20^{\circ}C$. Weight loss, color, firmness, gas composition $(O_2,\;CO_2)$ inside the film package and ethanol content in the tissue of MA packaged mushrooms were examined. Mushroom that were packed unwrapped in a conventional hardboard box (2 kg) lost marketability at a very early stage of storage due to weight loss, shrinkage, browning, and spore formation. During storage, film packaging prevented or retarded the deterioration of the mushrooms in the aspects of appearance, texture, and discoloration. Firmness slightly decreased with storage time. Total color difference was much higher in the control than in the film-packaged mushroom and rapidly increased at the early of storage. Correlation analysis showed a high correlation between total color difference and b values. These results were characterized by the reduced respiration rate resulting from elevated carbon dioxide and reduced oxygen levels in the package. At all storage temperatures, ethanol content in the tissue increased slightly at the early part of storage and rose considerably towards the end of the storage period. Ethanol content in the oyster mushrooms was higher in the stipe than in pileus tissues. The shelf life of the oyster mushrooms was about $8{\sim}11$ days at $0^{\circ}C$, about $4{\sim}6$ day at $5^{\circ}C$, about $2{\sim}3$ days at $10^{\circ}C$, and about $1{\sim}2$ days at $20^{\circ}C$.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.342-347
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• 2004

A bacterial strain YC4963 with antifungal activity against Colletotrichum orbiculare, a causal organism of cucumber anthracnose was isolated from the rhizosphere soil of Siegesbeckia pubescens Makino in Korea. Based on physiological and biochemical characteristics and 16S ribosomal DNA sequence analysis, the bac­terial strain was identified as Pseudomonas aurantiaca. The bacteria also inhibited mycelial growth of several plant fungal pathogens such as Botrytis cinerea, Fusarium oxysporum and Rhizoctonia solani on PDA and 0.1 TSA media. The antifungal activity was found from the culture filtrate of this isolate and the active compound was quantitatively bound to XAD adsorption resin. The antibiotic compound was purified and identified as phenazine-l-carboxylic acid on the basis of combined spectral and chemical analyses data. This is the first report on the production of phenazine-l-carboxylic acid by Pseudomonas aurantiaca.