• Clean Technology
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• v.22 no.2
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• pp.82-88
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• 2016

The loss of activity by coke is an important cause of catalyst deactivation during industrial operation. In this study, hydrogen ratio of reaction condition, which has influenced on coke formation over Pt-Sn catalyst, and regeneration of catalysts activity by coke burning, Pt sintering of coke burning as coke contents, effects of coke formation and deactivation with different Sn contents were confirmed. Pt-Sn-K catalyst supported on θ-alumina and γ-alumina was prepared progressively. Activity of regenerated catalyst for propane dehydrogenation was compared with fresh catalyst by coke burning, after propane dehydrogenation was carried out with different hydrogen ratio at 620 ℃ on fresh catalyst. Regenerated catalyst’s physical characterization such as BET, coke analysis and XRD was investigated. Through catalytic activity test and characterization, Sn contents of catalyst and hydrogen ratio in feed stream could affect coke formation on catalyst surface. Excessive coke makes loss of activity and Pt sintering during air regeneration process.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.199-204
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• 2010

Much of the coal ash by thermal power plant has gradually been increased, however researches on the recycling of bottom ash has not been investigated enough so far. In this research, the lysimeter test was conducted to find out the possibilities of bottom ash as soil amendment to improve the physiochemical properties of sandy topsoil of turfgrass in golf course. The turfgrass growth test and leaching test were conducted on the lysimeter. The lysimeter columns were manufactured with various topsoil mixing ratios of 0, 10, 20, 30, and 50% of bottom ash with sand. As a result of leachate analysis through the lysimeter column, the higher ratios of bottom ash mixed affect significantly on water holding capacity of topsoil sand media with decreasing of the percolation rate. The results of leachate analysis in every three days interval, the pH of leachate increased with the bottom ash ratios, but the volume of $NO_3$-N, $NH_4$-N and K decreased significantly. However, the level of EC of leachate had constantly maintained. These results indicate that the application of bottom ash may improve turfgrass growth with water holding capability and fertility of sandy topsoil. However, the negative effects of the bottom ash also evaluated by reducing water permeability and solubility of $PO_4$-P by adsorption into soil particles. The results indicates that the reasonable mixing ratio of the bottom ash as soil amendment should be less than 20% (v/v) with sand which has a low water-holding and fertility in golf course topsoil layers.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.4
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• pp.257-266
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• 2006

Studies were carried out to evaluate the effect of liquid pig manure on the production of Japanese millet, the chemical characteristics of pasture soil and leaching water. The study was undertaken from June to September 2005. Randomized complete block design was used to allot four treatments: T1 (no fertilizer), T2 (N : 200 kg/ha, p : 150 kg/ha, K : 150 kg/ha), T3 (liquid pig manure containing 1.7% DM 200 kg N/ha) and T4 (liquid pig manure containing 7.0% DM 200 kg N/ha). Leaching water was sampled at 21 August (1st time), 9 September (2nd time) and 26 September (3rd time), 2005, respectively. No significant differences in the dry matter yield of Japanese millet was found among the four treatments, whereas the plant lengths of Japanese millet were higher in the T2, T3 and T4 than in T1 (p<0.05). Nitrogen, P and K uptake of J. millet tended to be influenced by application of chemical fertilizer or 7.0% DM liquid pig manure compared with T1 or 1.8% DM liquid pig manure. The organic matter (OM) content of soil was higher in T2, T3 and T4 than in T1. Na content was highest in T3 among the four treatments. $NO_{3^-}N\;or\;NH_{4^-}N$ content in leaching was not different among the four treatments. $SO_4$ content in leaching water sampled in 1st time was high in T4, but in T3 from 3rd time (p<0.05). Cl, Mg and Na contents were high in leaching water sampled in the 1st time from T4, whereas high in those from T3 in 2nd or 3rd time. Results show that the application of a high DM liquid pig manure is not better for producing Japanese millet and improving the properties of pasture soil than a low DM liquid pig manure. However, the contents of $SO_4$, Cl, Mg and Na in leaching water sampled in 1st time were high in a high DM liquid pig manure.

• Product Safety
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• s.87
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• pp.50-59
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• 2001

기술표준원은 전기용품안전관리법의 개정시행으로 2000. 7. 1부터 전기용품형식제도가 안전인증제도로 변경되면서 전기용품기술기준을 연차적으로 국제기준(IEC)체제의 안전기준으로 전환됨에 따라 새로이 적용되는 국제기준 체제에 부합하는 전기용품안전기준의 조기정착과 전기용품의 안전성 확보를 지원하기 위하여 안전기준에 대한 토론회를 개최하고 있다.

• Korean Journal of Crystallography
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• v.1 no.2
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• pp.76-83
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• 1990

The structures of dehydrated fully Ca2+ _exchanged zeolite A (a: 12.2a3(2) A and of its iodine sorption complex (a=12.258(2) A) have been determined by single-crystal X-ray diffraction methods in the cubic space group. Pm3m at 21(1)℃.the structures were refined to final R(weighted) indices of 0.081 with 206 reflections and 0.084 with 173 reflections, respectively for which I>3 w (I). In each structure. six divalent cations are located on three different theefold axes associated with 6-ring oxygens. Dehydrated Ca2+_A sorbs ca. 6.0 diiodine molecules per unit cell at 80℃(vapor pressure of I: is ca. 14.3 Torr). Each iodine molecule makes a close approach. along its ahs to framework oxygen atom with I-I distance of 2.71(2) A, I-O distance of 3.32(3) k. and I-I-0=180℃. The result indicates that diiodine molecule forms charge transfer complex with framework oxygen.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.84-85
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• 2000

1996년도 우리나라 굴 총생산량은 약 20만여톤으로 일반 패류 생산량의 절반 이상을 차지하고 있으며, 대부분이 양식에 의존하고 있다(Korean Fisheries Associati 1997). 양식산 굴은 대략 11월부터 출하하기 시작하여 3월까지는 주로 생식용으로 내수 또는 수출되고 있고, 산란기로 접어드는 4월부터 6월까지는 통조림용으로 대부분이 이용되고 있다. 굴 통조림의 제조를 위한 원료 굴은 뻘 등의 제거를 위한 수세, 레토르트에서 자숙 및 탈각한 후 탈각 이물질, 껍질 조각 등을 제거하기 위하여 탈각굴에 대하여 수세 및 탈수와 같은 전처리 공정을 반드시 거친다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.103-104
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• 2001

1997년도 우리나라 굴 총생산량은 약 20만여톤으로 일반 패류 생산량의 절반 이상을 차지하고 있으며, 대부분이 양식에 의존하고 있다. 양식산굴은 대략11월부터 출하하기 시작하여 3월까지는 주로 생식용으로, 산란기로 접어드는 4월부터 6월까지는 주로 통조림용으로 이용되고 있다. 통조림의 제조를 위한 원료 굴은 델 등의 제거를 목적으로 수세하고, 레토르트에서 자숙 및 탈각한 후 이물질 등을 제거하기 위하여 탈각 굴에 대하여 수세 및 탈수와 같은 전처리 공정을 거치게 된다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.124-125
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• 2001

1997년도 우리나라 굴 총생산량은 약 20만여톤으로 일반 패류 생산량의 절반 이상을 차지하고 있으며, 대부분이 양식에 의존하고 있다(Korean Fisheries Association, 1998). 양식산 굴은 대략 11월부터 출하하기 시작하여 3월까지는 주로 생식용으로, 산란기로 접어드는 4월부터 6월까지는 주로 통조림용으로 이용되고 있다. 통조림의 제조를 위한 원료 굴은 뻘 등의 제거를 목적으로 수세하고, 레토르트에서 자숙 및 탈각한 후 이물질 등을 제거하기 위하여 탈각 굴에 대하여 수세 및 탈수와 같은 전처리 공정을 거치고, 이 때 부산물로 자숙수와 세척수가 발생한다. (중략)

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.189-194
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• 2013

A sulfonated activated carbon (AC-$SO_3H$) was used as a solid acid catalyst for dehydration of sorbitol to isosorbide and its catalytic performance was compared with the commercial solid acid such as acidic ion exchange resin, Amberlyst-36, and sulfated copper oxide. The catalytic performance with 100% sorbitol conversion and 52% isosorbide selectivity was obtained over AC-$SO_3H$ at 423.15 K. Although AC-$SO_3H$ possessed only 0.5 mmol/g of sulfur content, it showed the similar dehydration activity of sorbitol to isosorbide with Amberlyst-36 (5.4 mmol/g) at 423.15 K. Based on the high thermal and chemical stability of AC-$SO_3H$, one-step reactive distillation, where isosorbide separation can be carried out simultaneously with sorbitol dehydration, was tried to increase the recovery yield of isosobide from sorbitol. The reactive distillation process using AC-$SO_3H$, the turnover number of AC-$SO_3H$ was 4 times higher than the conventional two-step process using sulfuric acid.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.1
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• pp.21-26
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• 1994

Lysimeter experiments were carried out to study the vertical distribution of inorganic nitrogen, the changes in pHs of soil and leachate and the fate of applied nitrogen with or without grass. The concentration of $NO_3-N$ of surface soil(0~20cm) at the rates of 0, 7, 14 and 21kg N/10a ranged from 4 to 13mg/kg, while those of subsurface soi1(20-40cm) were below 10mg/kg at 0, 7 and 14kg N/10a and subsequently increased to 83.8mg/kg at 35kg N/10a. The concentration of $NH_4{^+}-N$ was positively correlated with that of $NO_3-N$ for surface soil(>0.05). However, the concentration of $NH_4{^+}-N$ was negatively correlated with that of $NO_3-N$ for subsurface soil. A positive correlation was observed between $NO_3-N$ and extractable cations of soils. The pH of subsurface soil decreased with the $NO_3-N$ concentration and the N application rate, while that of leachate inereased with the N application rate. The pH differences between subsurface soil and leachate were 2.5 for bare soil and 3.1 for 35kg N/10a. Higher N application rate caused more soil N accumulation and the gas loss and resulted in a larger difference between N uptake by grass and the applied N.