• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.131-132
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• 2011

This study analyzes the yearly-best delivered size range of truck mixer based on the specified mix, Water to Binder Ratio, aggregate proportion and unit amount with statistical method targeting on Kyeongi and Kyeongsang province and compares with the similar materials of Japan to propose as a basic standard for the quality control of mixer truck. As a result, in case of the Water to Binder Ratio of these areas, it is higher than Japan's due to the excessive safety rate reflecting the changes of differential value impact and unit amount, and the unit amount's standard deviation is very large by reflecting the changes of the amount used and chemical admixture susceptibility. In case of aggregate proportion, the frequency rate is about 50%, which is very similar value with Japan's one.

• Journal of the Korean Applied Science and Technology
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• v.25 no.4
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• pp.495-502
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• 2008

To investigate the synergy effect on the pyrolysis of mixture of polyethylene(PE) and polystyrene(PS), the pyrolysis of PE, PS and the mixture of PE-PS was carried out in a batch reactor at the atmospheric pressure and $450^{\circ}C$. The pyrolysis time was from 20 to 80 mins. The liquid products formed during pyrolysis were classified into gas, gasoline, kerosene, gas oil and heavy oil according to the distillation temperatures based on the petroleum product quality standard of Korea Institute of Petroleum Quality. The analysis of the product oils by GC/MS showed that the new components produced by mixing were not detected. The synergy effect according to mixing of PE and PS did not also appear. The conversion and yield of mixtures were in proportion to the mixing ratio of sample.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.972-977
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• 2017

The propellant tile and crack which account for the greatest proportion of solid rockets are profoundly affected by viscosity and mechanical properties of solid propellant. In this paper solid propellant with nitrate ester polyester(NEPE) system has been researched for the viscosity, mechanical properties and burning properties with size and mixing ratio of RDX. the viscosity of propellant was changed significantly depending on the size of RDX and mixing ratio, and mechanical properties of NEPE system propellant were also varied. Considering both lower viscosity and stable mechanical properties, the optimum size and mixing ratio of RDX can be identified as the main factors to the NEPE system propellant.

• Journal of the Korean Society of Safety
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• v.20 no.4 s.72
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• pp.46-53
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• 2005

Existing study far fire-resistant concrete has been done already. but it is not found out how the waste tyre mixing concrete will be acted against fire. This waste tyre concrete molds under the condition of $0^{\circ}C,\;200^{\circ}C,\;400^{\circ}C,\;600^{\circ}C$ were heated in gas oven. It was worried about that they might be fractured down at about $800^{\circ}C$ so that they can not be tested. compressive strength for the test molds are made with commercially used $180kg/cm^2,\;210kg/cm^2,\;240kg/cm^2,\;270kg/cm^2$ mixing saw dust with proportion such as 0.05%, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0% compressive strength at $200^{\circ}C$ was approximately 20% from the original, while approximately 30% deoreased at $400^{\circ}C$. their results are not quite different from the normal concrete condition even though they contains saw dust in it. The higher strength the concrete has, the less strength was decreased. There are almost no difference in strength under the condition of less than $400^{\circ}C$, but damage of concrete structure could be considerable large with more than $400^{\circ}C$.

• Advances in concrete construction
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• v.10 no.3
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• pp.221-236
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• 2020

To reduce the CO₂ emissions associated with the manufacture of portland cement (PC), an efficient alternative like an alkali-activated binder (AAB) is the requirement of the industry. To promote the use of AAB in construction activities, a practically implementable mix proportion is required. Owing to the several raw ingredients of AAB concrete and their associated uncertainties, partial replacement of PC by AAB may be adopted instead of complete replacement as per industrial requirements. Hence, the present study aims to determine an optimal proportion for partial replacement of PC with AAB and recommend a technique for it based on site conditions. Three modes of partial replacement are followed: combining all the dry ingredients for AAB and PC followed by the addition of the requisite liquids (PAM); combining the PC and the AAB concrete in two horizontal layers (PAH); and two vertical layers (PAV). 28-day old specimens are exposed to 10% v/v solutions of HCl, H₂SO₄, and HNO₃ to evaluate changes in mechanical, physical, and microstructural characteristics through compressive strength, corrosion depth, and microscopy. Based on deterioration in strength and integrity, PAH or PAV can be adopted in absence of acid attack, whereas PAM is recommended in presence of acid attack.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.5
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• pp.63-68
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• 2009

This study describes to analyze foam mixing characteristics in steady state to enhance the performance of proportioner for foam system designed to accurately proportion a foam liquid concentrate into a water stream up to constant concentration. The proportioner developed is experimentally evaluated in performance evaluation system consisted of a pump, tanks, pressure gauges, flow meters, a nozzle. As a result, the foam mixing performance of the line proportioner is found to increase with increased the water flow rate due to the venturi effect and with increased the cross-sectional area of the orifice and is analysed with 3 % in the error rate of $\pm4%$. For the pressure proportioner, the foam mixing performance is analyzed to increase with increased the water flow rate and with increased the inlet pressure and is analysed with 3% in the error rate of $\pm2%$.

• Journal of Technologic Dentistry
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• v.2 no.1
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• pp.11-15
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• 1980

This study was aimed at obtaining an ideal gold alloy for dental prothetic. The experiment was on physical characteristics of gold alloy and mixing proportion for proper appliance to living tissues. The most frequently used material in the past for dental prothetic was gold, but recently used are mictures or precious metals and non-precious, which are proved to affect on oral tissues. The experiment was to examine gold alloy over its physical and chemical qualities and to make an ideal type of gold alloy by means of statistic and laboratory research.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.5
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• pp.201-206
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• 2018

This study investigated the changes in pore water quality of polluted sediment by mixing ratio of granulated coal ash. The mesocosm experiments were carried out with 0%, 10%, 30% and 50%, respectively, of the material mixture ratio relative to the sediments. According to the results of the experiments, pH increased depending on the mixing ratio. Phosphate and ammonia concentrations were significantly decreased in the mixing ratio of 30% and 50% compared to the control (p < 0.05). The concentration of hydrogen sulfide was reduced by 72% at the mixing ratio of 10%, and it was not detected at the mixing ratio of 30% and 50%. This study was confirmed that granulated coal ash can change the pore water quality of polluted sediments in proportion to the amount of material. However, the effect of the mixing ratio between 30% and 50% was not significantly different, thus it is concluded that mixing of 30% of the volume of the sediment is economically feasible.

• Culinary science and hospitality research
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• v.23 no.2
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• pp.181-188
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• 2017

Aronia is a superberry that contains antioxidants. Due to its nutritional value, it has received much attention and has been widely researched. In this study, the proportion of aronia powder applied to spelt wheat flour was measured with the pH ratio of the additive and respondents' preference was examined for the preferred addition to the additive population. As a result of the acidity measurement, the pH value tended to decrease as the amount of aronia powder was increased. As for the fermentation expansion rate, the volume of the dough added with aronia powder was measured to be slightly smaller than that without addition of aronia powder. Preference of breads with aronia powder added showed higher preference when 6% was added compared to when 3% of aronia powder was added. As a result of preference survey of breads containing aronia powder, the most preference was given to taste when 3% of aronia powder was added. Color, fragrance, and overall acceptance were the most preferred when 6% of aronia powder was added. Based on these results, the optimal mixing ratio of aronia powder to spelt flour bread was selected to be 6% of aronia powder.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.557-560
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• 2008

This was done by analyzing the sandwich panels that are now widely used in construction work. Sandwich panels are used for diverse purposes in construction work worldwide. In Korea, polystyrene panels that have organic materials as their core material are used. These panels are thus very vulnerable to fire, with risks of core melting, sheet deformation, and hazardous gases. Accordingly, sandwich panels' fire-resistant or non-flammable properties must be secured. To solve these problems, the optimal mixing proportion of lightweight foamed concrete for the sandwich panel core was determined. A new method of doing this was introduced that is completely different from the existing method, wherein a foaming agent is added to realize lightweight concrete. For lightweight concrete, the foaming mechanisms via diverse chemical reactions were identified, H$_2$O$_2$ was added for heating in the reaction, and the concrete foaming was maximized. Through diverse experiments to determine the optimal mixing proportion of lightweight foamed concrete and to examine the filling characteristic of lightweight foamed concrete for sandwich panel cores using waste materials, the physical and mechanical properties of lightweight foamed concrete were examined.