• Bulletin of the Korean Chemical Society
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• 제11권5호
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• pp.403-406
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• 1990

Two types of new silica catalysts modified with benzenesulfonic acid derivatives were prepared by esterification or phenylation followed by sulfonation. Both catalysts thus prepared were tested as acid catalysts for 2-propanol dehydration and cumene dealkylation reactions. B catalyst () were more active than A catalyst (). Highter catalytic activity for B catalyst may be accounted for by higher resistance to water, higher acid strength, more acidity, and better thermal stability as compared with A catalyst.

• 대한화학회지
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• 제36권5호
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• pp.784-787
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• 1992

• 대한화학회지
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• 제39권6호
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• pp.485-488
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• 1995

• 대한화학회지
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• 제40권6호
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• pp.453-456
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• 1996

• Bulletin of the Korean Chemical Society
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• 제15권11호
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• pp.919-922
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• 1994

• Computers and Concrete
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• 제25권1호
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• pp.59-65
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• 2020

The premise for the study reflected in this article is the need to dispose of industrial waste, which is increasingly being used in the construction materials industry. Also, dynamically developing building industry demands attention of scientists and a direction of their works on improvement of the technology of carrying out construction works. Thus, the article is devoted to studying the influence of various chemical additives and fine fillers (industrial wastes) available in Kazakhstan on self-compacting concrete (SCC) mixtures and its rheological, physical, and technical properties. According to the studies, revealed the most efficient type of fine-dispersed filler and the most optimal type of chemical additive to enable obtaining a high-quality SCC mixture based on local raw materials. As a result, the use of microsilica in comparison with other industrial wastes resulted in a conglomerate with high compressive strength of SCC at early terms of curing. In terms of economic efficiency and quality improvement, the results of study are of practical value for the manufacturers of ready-mixed concrete operating in Kazakhstan.

• 대한화학회지
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• 제33권4호
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• pp.439-441
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• 1989

• Bulletin of the Korean Chemical Society
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• 제12권6호
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• pp.649-652
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• 1991

The reaction of primary aromatic amines with 1,7-heptanediol in the presence of a catalytic amount of ruthenium complex in dioxane at $180^{\circ}C$ for 24 hours gave the corresponding 1-substituted perhydroazocines in moderate yield.

• Korean Chemical Engineering Research
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• 제56권5호
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• pp.773-778
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• 2018

In-situ transesterification of microalgae lipids using microwave irradiation has potential to simplify and accelerate biodiesel production, as it minimizes production cost and reaction time by direct transesterification of microalgae into biodiesel with microwave as a heating source. This study was conducted to research the effect of microwave irradiation with in-situ transesterification of microalgae under base catalyst condition. The process variables (reaction time, solvent ratio, microwave power) were studied using 2% of catalyst concentration. The maximum yield of FAME was obtained at about 32.18% at the reaction time of 30 min with biomass-methanol ratio 1:12 (w/v) and microwave power of 450 W. The GC MS analysis obtained that the main component of FAME from microalgal oils (or lipids) was palmitic acid, stearic acid and oleic acid. The results show that microwaves can be used as a heating source to synthesize biodiesel from microalgae in terms of major components resulting.

• 한국표면공학회지
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• 제49권4호
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• pp.363-367
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• 2016

For the industrial application of electropolishing process, we investigated electropolishing characteristics of stainless steel through increasing the specimen size or electrode gap. In this study, we performed a set of experiment with the specimen size of $10cm{\times}10cm$ and the electrode gap of 1 cm or more. In the view of the electropolishing process, the electrolyte temperature and the polishing time were most important factors compared with the current density and the electrode gap. Especially, the electrolyte temperature most importantly affected surface roughness and current efficiency on electropolishing characteristics. For the industrial application of electropolishing process, it should be considered for important factors such as electrolyte temperature, polishing time, current density and electrode gap, etc.