• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2014.05a
• /
• pp.280-281
• /
• 2014

Recently, it is certain that the increase of heating and cooling energy consumption by radical change in climate condition has caused serious problems related to environmental and energy concerns associated with increase of fossil fuel usage and carbon dioxide production as well as global warming. Therefore, various actions to reduce greenhouse gas and energy consumption have been prepared by world developed countries. The energy consumption by buildings approximately reaches 25% of total korea energy consumption. The greatest part in the buildings of the energy consumption is building facade. But a few research projects on concrete comprising more than 70% of outsider of buildings has been tried. This research is structural insulation concrete what improved insulation performance using micro form admixture and calcined diatomite powder and lightweight aggregate.

• Journal of the Korean Ceramic Society
• /
• v.42 no.4
• /
• pp.260-268
• /
• 2005

A heat-resisting diatomite protection tube, using diatomite as a main component, was manufactured through an extrusion molding of ceramic slurry in different component ratios. And its mechanical strength, carbon analysis and microstructural non-homogeneity were investigated. After fixing $60wt\%$ of porous diatomite whose particle size was $50\~100\;{\mu}m$, the optimum mixture ratio with composition variables by changing $1\;wt\%$ of each component that was silica sol$(4.3\~7.3\;wt\%)$ as an inorganic binder, CMC (Sodium CarboxyMethyl Cellulose $(6\~9\;wt\%)$) as an organic binder and paper powder$(4.7\~7.7\;wt\%)$ was obtained. As a result of the investigation on a composition containing $60\;wt\%$ diatomite, $5.3\;wt\%$ silica sol, and $7\;wt\%$ CMC, a heat-resisting protection tube that could be used as a molten steel probe for measuring the temperature and components of molten steel was developed. The bending strength, compressive strength, and elastic modulus of the protection tube developed, that contained $\le2.3\;wt\%$ carbon, were 7.1 MPa, 7.5 MPa, and 1090 MPa, respectively.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.19 no.3
• /
• pp.22-29
• /
• 2015

In this study, we tested to develop and apply structural insulation performance improvement concrete to field, which had compressive strength in 24 MPa and thermal conductivity twice as much as normal concrete. After experiment about slump and air contents, combination product of Plain and calcined diatomite powder showed reduction of slump and air contents and combination product with micro foam cell admixture, we cannot find result of slump and air contents reduction. Unit weight of combination product with insulation performance improvement materials decreased more than that of Plain. In the test of compressive strength, compressive strength of insulation performance improvement concrete decreased more than that of Plain but was content with 24 MPa. thermal conductivity of insulation performance improvement concrete tended to decrease. Freezing and thawing resistance of insulation performance improvement concrete was similar to that of Plain. In carbonation resistance test, combination product with calcined diatomite powder showed the result which was similar to that of Plain. In carbonation resistance test, combination product with micro foam cell admixture showed a increase compared to that of Plain and length variation of combination product generally increased.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.29 no.3
• /
• pp.271-277
• /
• 2019

Objectives: A 46-year-old woman who had worked on cleaning stainless steel containers with Initially unknown powders died from acute silicosis. To determine whether the acute silicosis was related to his work environment, we conducted exposure assessment the level of exposure to respirable crystalline silica(RCS) during cleaning stainless steel containers with unknown powders. Methods: The exposure assessment of RCS were undertaken according to the National Institute for Occupational Safety and Health(NIOSH) method 7500. The components of the unknown powder were analyzed using X-ray Diffraction. Results: The unknown powder was found to be natural diatomaceous earth, which contained 12% and 9% quartz and cristobalite, respectively, crystalline silica. In the case of cleaning stainless steel containers with diatomaceous earth powder, the primary measurement resulted in 1.3 times higher occupational exposure limit of MOEL(in sum of quartz and cristobalite concentration) and 3.9 times higher in secondary measurement. The workbench was equipped with a local exhaust system, but because there was no hood at the end of the duct, the wind speed at the opening of the duct was 12 m/sec, whereas the controlled wind speed at the working position was only 0.3 m/sec below the legal standard. Conclusions: There is an urgent need to install the hood, conduct safety and health education for employers and workers, and periodically monitoring and manage the working environment.

• Magazine of the Korea Concrete Institute
• /
• v.9 no.1
• /
• pp.143-151
• /
• 1997

Chemical resistance of the cement mortar containing the Thermally Activated Diaomite(TAD) and H.M.(Heavy Metals) has been studied. The H.M.. extracted from EAF(Electrica1 Arc Furnace) Dust. were saturated with diatomite. The diatomite was then thermally activated at $750{\circ}C$ for 30minutes and powdeled. The powder was mixed with a portland cement on a weight basis from 0%. 2.5%. 5.0%. 10%. 20%. The optimum mixture. after those mixtures were subjected to compressive strength(7 and 28days) and leaching bchaviour of H.M.. was tested for its experiment on Wet/Dry cycles and chemical resistance(e.q. imrncrsion in 5%(Conc.) of H2S04, CaC12 and hlgSO4. It was shown that the cement, mortar containing 10% of' P.D. gave a rise to the remarkable increase in compressive strength. The compressive strength was generally decrease beyond the addition of 10% of P.D. The maximum $496kgf/cm^2$ of 28days compressive strength was acheiveti when 10% of P.D. was added to the cement mortar.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.11a
• /
• pp.40-41
• /
• 2013

The energy consumption by buildings approximately reaches 25% of total korea energy consumption. The greatest part in the buildings of the energy consumption is building facade. but a few research projects on concrete compising more than 70% of outsider of buildings has been tried. This research is structural insulation concrete what improved insulation performance using micro form admixture and calcined diatomite powedr and lightweight aggregate.

• Journal of Life Science
• /
• v.17 no.12
• /
• pp.1605-1609
• /
• 2007

The created microbial pesticide was used to examine its effects using the inside-pot test method. The selected microbial pesticide KBC3017 particle pesticide manufactured by using Monacrosporium thaumasium was used in the farm-house outdoor test to find the optimum consistency and its effects. The more amount used, the better effect it showed. However, the optimum consistency was 2% and the KBC3017 particle pesticide for which the diatomite and raw jade powder were used as an increaser, when used 2% level of the total amount of soil, showed 71% effect on nematode prevention. The root and the stem of crops were better compared to those without any pesticide used.

• Journal of Adhesion and Interface
• /
• v.22 no.1
• /
• pp.22-28
• /
• 2021

Products using diatomaceous earth, which are used in various fields, are optimized for moisture absorption, but have problems such as high hardness, powder flying, and rough surface feel. To improve this, an olefin-based foam having low hardness and high elasticity was prepared by adding an excessive amount of inorganic material using EVA (Ethylene vinyl acetate) having low hardness and excellent elasticity. Diatomaceous earth was added to impart moisture absorption characteristics of the foam, and the moisture absorption/drying characteristics showed a moisture absorption rate of about 10 to 15% and a moisture drying rate of 10 to 70% depending on the content of the diatomaceous earth. Through this study, it was possible to manufacture a water-absorbing olefin-based foam with diatomaceous earth added, and it was confirmed that the diatomaceous earth added to the foam had a great influence on water absorption and dissipation due to its microstructure and characteristics.

• Journal of the Korean GEO-environmental Society
• /
• v.12 no.2
• /
• pp.55-61
• /
• 2011

NDMA(N-Nitrosodimethylamine) has been considered as a carcinogenic pollutant even at extremely low-concentration (10ng/L). However, previous researches on NDMA have focused on mainly high concentration due to a difficulty of analysis. In this study, removal efficiencies were evaluated for individual or combined methods with PAC(Powder Activated Carbon), GS(Granular Sludge), MF(Microfiltration), UF(Ultrafiltration) and Silica gel(MCM-41, Diatomite, Spherical silica gel) at both aerobic and anaerobic conditions. Combined method of GS, PAC and UF membrane at anaerobic condition showed the highest removal efficiency of 65% while Silica gel showed the lowest removal efficiency of 6%. The outcomes of this study could be used further study of extremely low-concentration NDMA removal.

• Journal of the Korean Ceramic Society
• /
• v.34 no.8
• /
• pp.797-802
• /
• 1997

The use of carbon materials in mechanical components such as bearings, seals, and bushings that do not require lubricants is increasing rapidly. This paper reports on establishing the optimal condition for resin-bonded carbon materials. We fixed the content ratio of materials, which include graphite powder and diatomite as a lubricant modifier and a friction modifier, respectably, with resin used as a bonding material. We then produced bushings using hot-pressing within the temperature range of resin curing. The properties of bushing, the friction coefficient, wear rate and the mechanical strengths are discussed in relation to the content of respective materials, with correlation of friction coefficient and sliding distance. Finally, we examined the friction coefficient changes according to the applied load on bushing and the friction coefficient changes according to contact speed of bushing.