• Journal of the Korean Chemical Society
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• v.62 no.5
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• pp.364-371
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• 2018

Inhibition effects of alanine (Ala), histidine (His), methionine (Met) on the corrosion of aluminum were investigated in deaerated 0.5 M HCl and NaCl solution. In HCl solution the inhibition efficiency for the aluminum corrosion depended on the cathodic inhibition, and the inhibition efficiency was increased in the order of Met$10^{-4\;}M$ the adsorption process can be explained by Langmuir isotherm, however, in the case of higher concentration by Temkin logarithmic isotherm due to the interaction between the adsorbed molecules.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.244.2-244.2
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• 2010

Biological conversion of biomass into fuels and chemicals requires hydrolysis of the polysaccharide into monomeric sugars. In this study, dilute sulfuric acid used as a catalyst for the pretreatment of rapeseed straw. Hydrolysis can be performed enzymatically, and with dilute or concentrate mineral acids. Dilute-acid hydrolysis of rapeseed straw was optimized through the utilization of combined severity. Evaluation criteria for optimization of the pretreatment conditions were based on high xylose recovery and low inhibitor contents in the hydrolyzates. In addition, this paper reports the compositional analysis of hydrolyzate liquors and solid residues, xylose and glucose mass balance closures, and digestibility results of the acid pretreated rapeseed straw.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.318-321
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• 2003

This study explored the feasibility of applying Electrokinetic-Fenton process(EK-Fenton process) to remediation of contaminant sorbed on the soil possessed low-permeability. The addition of 0.01 N H$_2$SO$_4$ in the anode reservoir for the $H_2O$$_2$stabilization improved the stabilization of $H_2O$$_2$and the treatment effect of phenanthrene across the entire soil specimen. The use of $H_2O$$_2$and dilute acid as anode purging solution is a promising method treating of HOCs in low-permeability subsurface environments.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.1
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• pp.1-8
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• 2022

With the spread of COVID-19 worldwide, non-face-to-face services have grown rapidly, but at the same time, the problem of plastic waste is getting worse. Accordingly, eco-friendly policies such as carbon neutrality and sustainable circular economy are being promoted worldwide. Due to the high demand for eco-friendly products, the packaging industry is trying to develop eco-friendly packaging materials using PLA and PBAT and create new business models. On the other hand, Ulva australis occurs in large quantities in the southern seas of Korea and off the coast of Jeju Island, causing marine environmental problems. In this study, lactic acid was produced through dilute acid pretreatment, enzymatic saccharification, and fermentation processes to utilize Ulva australis as a new alternative energy raw material. In general, seaweeds vary in carbohydrate content and sugar composition depending on the species, harvest location, and time. Seaweed is mainly composed of polysaccharides such as cellulose, alginate, mannan, and xylan, but does not contain lignin. It is difficult to expect high extraction yield of the complex polysaccharide constituting Ulva australis with only one process. However, the fusion process of dilute acid and enzymatic saccharification presented in this study can extract most of the sugars contained in Ulva australis. Therefore, the fusion process is considered to be able to expect high lactic acid production yield when a commercial-scale production process is established.

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.14 no.1
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• pp.59-77
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• 2003

This study was carried out to find a cholesterol removal rate, flavor development, and bitter amino acid productions in Cheddar cheese treated with -cyclodextrin ($\beta$-CD): l) Control (no homogenization, no $\beta$-CD), and 2) Milk treatment (1000 psi milk homogenization, 1 % $\beta$-CD). The cholesterol removal of the cheese were 79.3%. The production of short-chain free fatty acids (FF A) increased with a ripening time in both control and milk treated cheese. The releasing quantity of short-chain FFA was higher din milk treated cheese than control at 5 and 7 mo ripening. Not much difference was found in neutral volatile compounds production between samples. In bitter-tasted amino acids, milk treatment group produced much higher than control. In sensory analysis, texture score of control Cheddar cheese significantly increased, however, that in cholesterol-reduced cheese decreased dramatically with ripening time.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.10
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• pp.901-909
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• 2012

This paper describes characteristics of solid-state $NaBH_4$ hydrogen generation and supply system for fuel cell UAV. Flow rate and pressure of the generated hydrogen were dramatically changed during $NaBH_4$ decomposition using acid. Hydrogen supply was stabilized by a self-pressurized reactor, and hydrogen stabilization method was introduced. For hydrogen generation in below zero-temperature, hydrochloric acid was diluted by propylene glycol-water mixtures. Solid-state $NaBH_4$hydrogen generation and supply system was designed. Basic operation experiments was performed to reveal the characteristics of this hydrogen generation system.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.9-13
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• 1986

An experiment on strawberry (Fragaria Grandflora EHRH) was conducted in order to compare the effect of two compound fertilizers made for this crop, by Kyonggi Chemical Crop. LTD. with that of muriate of potash, sulfate of potash and ammonium nitrate in a farmer's vinylhouse during the winter period of 1984 to 1985. Results obtained are as follows; 1. The effect of compound fertilizers on the growth, number of inflorescences and yield of strawberry showed no significant difference from the effect of muriate of potash, sulfate of potash and ammonium nitrate. But the former increased the content of reduced, and total sugars soluble in diluted acid in the juice of strawberry. 2. As a whole, sulfate of potash increased sugar content in strawberry juice more than muriate of potash, which became the reason to increase the sugar content in the strawberry juice harvested from the compound fertilizer plots.

• Journal of the Korean Chemical Society
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• v.46 no.2
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• pp.99-116
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• 2002

The thiazolylazo compounds and their Co(II), Ni(II) and Cu(II) complexes of barbituric acid, uracil, thiouracil, citrazinic acid, chromotropic acid, gallic acid, pyrogallol and salicylic acid were pre-pared and characterized by $^1H$ NMR , IR and the effect of pH on the electronic absorption spectra . The mode of ionization, the electronic transitions and the dissociation constants were discussed. The stoichiometries of the complexes were of 1:1, 2:1 and 3:2 (M:L). The copper complexes are of isotropic ESR spectra (except that of gallic acid which showed a complicated one) and are of magnetically diluted behaviour with orbital con-tribution. Detailed DTA data were obtained and discussed.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2001.11a
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• pp.22-22
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• 2001

전통적으로 초경합금은 무라까미 용액에서 에칭하거나 묽은 염산에 넣고 끓이는 방법에 의해 그 밋구조를 관찰하였다. 그러나 carbide 입자가 suvmicron 크기인 초경합금에서는 전통적인 에칭 방법으 에칭 후에도 입자/기지상, 입자/입자 입계를 동시에 구분시킬 수 있는 SEM 사진을 얻을 수 없다. 본 연구에서는 submicron 크기 초경합금의 고배율 SEM 사진을 얻을 수있는 90H2O2 - 10HNO3 (vol%)의 새로운 에칭 용액을 개발하였다. 경명의 submicron 크기 WC-Co 시편을 샐운 에칭 용액인 90H2O2 - 10HNO3 (vol%)에 넣고 약 6$0^{\circ}C$에서 약 12분 동안 에칭하였다. 에칭에 의해 Co 기지상은 빠르게 제기(dissolution)되었고, 동시에 표면의 WC 입자들은 각각의 결정학적 방향에 따라 천천히(slowly) 다른 속도로 부식(sissolution)되었다. 고배율 SEM을 관찰한 결과 WC/기지상 계면과 WC/WC 입계가 명화갛게 관찰되었다. WC 입자의 성장을 억제시키는입자성장 억제제(Cr3C2, TaC,VC)가 첨가된 WC Co 초경합금을 새로운 에칭 용액인 90H2O2 - 10HNO3 (vol%)에 넣고 약 6$0^{\circ}C$에서 약 12분동안 에칭하였다. 매우 작은 입자를 갖는 미세구조임에도 불구하고 고배율 SEM에서 WC/기지상 계면과 WC/WC 입계가 명확하게 관찰되었다. 90H2O2 - 10HNO3 (vol%)에서 Co 기지상이 빠르게 제거되는 것은 산 (acid)인 HNO3)에서 금속인 Co가 쉽게 녹기 때문이다. 동시에 WC 입자들이 각각 다른 속도로 에칭 된 것은 강력한 산화제인 H2O2가 각각의 WC입자 표면에 얇은 텅스텐 산화물 층을 형성시켰고 이들이 산인 HNO3에서 녹았기 때문이다. 본 연구에서 개발된 새로운 에칭 용액인 90H2O2 - 10HNO3 (vol%)의 에칭 원리가 똑같이 적용 가능한 다른 종류의 초경 합금에서도 사용이 가능할 것으로 판단된다.로 판단된다.

• Journal of the Korean Applied Science and Technology
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• v.16 no.2
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• pp.147-153
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• 1999

As main components of antifoamers, we were used fatty alcohols, fatty acid and fatty acid esters. Then the antifoaming properties on the particle size distribution, temperature and concentration for antifoamers was measured by Air Injection Method of ASTM under 1L/min air flow rate condition, and was measured surface tensions and emulsifying power of antifoamers. The antifoaming properties on the particle size distribution of antifoamers showed excellent antifoaming properties in the range of emulsion particle size from 5.5 to 6.8${\mu}m$. Surface tensions on the $10^{-2}$wt% aqueous solution of antifoamers was $33{\sim}34$ mN/m. And emulsifying power of fatty alcohol antifoamers showed good.