• Journal of Pharmaceutical Investigation
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• v.32 no.4
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• pp.305-311
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• 2002

In order to evaluate the effect of poloxamer 407 content on the dissolution profiles of pellets, diltiazem HCl (DTL) core pellets were prepared with poloxamer 407 (50-90% w/w, with lactose as filler) using an extruder and a spheronizer. Any possible interaction between the drug and excipients was evaluated using DSC, IR and TLC. Dissolution tests were performed using USP basket method. In addition, scanning electron micrograph was performed to examine the surface roughness and cross sections. The release of DTL from the core pellets was decreased with increasing poloxamer 407 content. Cracks appeared on the surface of the core pellets with increasing the poloxamer 407 content, which may play a role on the retardation of the release of DTL from core pellets. There was no any significant interaction between the drug and excipients employed to prepare the core pellets.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.2
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• pp.9-16
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• 2015

High loading of base paper is regarded as one of reasons to aggravate fold cracking of coated paper. But the relationship between the ash content of base paper and fold cracking of coated paper has not been shown yet. We investigated the effect of ash content in base paper on the fold cracking of coated paper. Handsheets with three different ash contents (19.5-23.5%) were prepared, and double layered coating were applied on the top side of the handsheets. A gravimetric water retention meter (AA-GWR) was employed to fold the paper with a uniform pressure after solid printing on the coated surface. The fold cracking was digitized by calculating the cracked area by means of an image analysis technique. Results suggested that high ash content in the base paper increased the fold cracking of the outer surface of coated papers. In the case of inner surface greater fold crack areas were obtained, and the number of cracks decreased because long and wide cracks were formed. Reduction in tensile strength and thickness appeared to give greater fold cracking for highly loaded papers.

• Macromolecular Research
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• v.12 no.1
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• pp.53-62
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• 2004

We have prepared polymer composites of low-density polyethylene (LDPE) and ionomers (Surlyn 8940) containing polar segments and metal ions by melt blending with carbon black (CB) as a conductive filler. The resistivity and positive temperature coefficient (PTC) of the ionomer/LDPE/CB composites were investigated with respect to the CB content. The ionomer content has an effect on the resistivity and percolation threshold of the polymer composites; the percolation curve exhibits a plateau at low CB content. The PTC intensity of the crosslinked ionomer/LDPE/CB composite decreased slightly at low ionomer content, and increased significantly above a critical concentration of the ionomer. Irradiation-induced crosslinking could increase the PTC intensity and decrease the NTC effect of the polymer composites. The minimum switching current (Ι$\sub$trip/) of the polymer composites decreased with temperature; the ratio of Ι$\sub$trip/ for the ionomer/LDPE/CB composite decreased to a greater extent than that of the LDPE/CB composite. The average temperature coefficient of resistance (${\alpha}$$\sub$T/) for the polymer composites increased in the low-temperature region.

• Journal of the Korea Concrete Institute
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• v.18 no.2 s.92
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• pp.219-226
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• 2006

The effects of binder content and PA content on the flexural, compressive and impact strengths, water absorption and frezzing and thawing of polymer concrete using mixed waste plastics are examined. As a result the flexural, compressive and impact strengths of the polymer concretes using mixed waste plastics tend to increase with increasing binder content and filler content, regardless of the PA content. The flexural, compressive and impact strengths of the polymer concretes using mixed waste plastics decrease with increasing PA content. The water absorption of the polymer concretes using mixed waste Plastics tend to decreased with increasing binder content, regardless of the PA content. The durability factor of the polymer concretes using mixed waste plastics tend to increased with increasing binder content. However, the durability factor of the polymer concretes using mixed waste plastics tend to decreased with increasing PA content.

• New & Renewable Energy
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• v.3 no.4
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• pp.38-46
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• 2007

In order to characterize the thermal conductivity and viscosity of grout materials used for backfilling ground heat exchangers, nine bentonite grouts and cement grouts being adapted in the United State have been considered in this study. The bentonite grouts indicate that the thermal conductivity and viscosity increase with the content of bentonite or filler (silica sand). In addition, material segregation can be observed when the viscosity of grout is relatively low. The saturated cement grouts appear to possess much higher thermal conductivity than the saturated bentonite grouts, and the reduction of thermal conductivity in the cement grouts after drying specimens is less than the case of the bentonite grouts. Maintaining the moisture content of grouts is a crucial factor in enhancing the efficiency of ground heat exchangers.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1463-1470
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• 2018

In this study, 20 types of samples were prepared by mixing different kinds of inorganic materials to develop insulation materials for epoxy - based GIS substation equipment used under high voltage environmentally friendly insulation gas. One of the electrical characteristics, AC insulation breakdown experiment was performed. As mixing ratio of mixed heterogeneous inorganic materials, the dielectric breakdown strength was increased with increasing filler ratio of micro silica, micro silica : micro Alumina, 1:9, 3:7, 5:5, 7:3, 9:1, and decreased as the filling amount of micro alumina increased. The AC insulation breakdown characteristics were the best when the composition ratio was 9:1. The higher the content of silica, the better the interfacial properties, and the larger the alumina content ratio, the worse the interfacial properties.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.529-532
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• 2007

In order to characterize the thermal conductivity and viscosity of grout materials used for backfilling ground heat exchangers, nine bentonite grouts and cement grouts being adapted in the United State have been considered in this study. The bentonite grouts indicate that the thermal conductivity and viscosity increase with the content of bentonite or filler (silica sand). In addition, material segregation can be observed when the viscosity of grout is relatively low. The saturated cement grouts appear to possess much higher thermal conductivity than the saturated bentonite grouts, and the reduction of thermal conductivity in the cement grouts after drying specimens is less than in case of the bentonite grouts. Maintaining the moisture content of grouts is a crucial factor in enhancing the efficiency of ground heat exchangers.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.597-600
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• 2014

In this work, the electromagnetic interference shielding effectiveness (EMI-SE) of carbon nanotube/carbon fiber-reinforced HDPE matrix composites are investigated with various preparation conditions, such as the carbon fiber and carbon nanotube content, the presence of metal additives, as well as mixing speed and time. It was found that the EMI-SE of the composites increased with filler contents and metal additives. These results indicate that the content and length of carbonaceous fillers determine the electric networks in the composites, resulting in the control of the EMI-SE of the composites.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.5
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• pp.615-627
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• 2024

This study presents fundamental research data on the application and utility of biochar in Engineered Cementitious Composites (ECC) for carbon sequestration. The study experimentally measures and compares the compressive strength, tensile strength, and flexural strength of high-toughness biochar-incorporated ECC (BE) and biochar-incorporated mortar (BM) with varying levels of biochar replacement. This study aims to compare BM and BE. BM shows an increase in mechanical properties at a biochar content of 1 %. BE shows an increase in mechanical properties at a biochar content of 2 %. The reason for the increase is that biochar particles fill the voids between the binder materials, acting as a filler. This helps form a denser structure. These findings suggest that incorporating biochar into mortar and ECC can enhance their mechanical properties at optimal biochar contents.

• Journal of the Korea Concrete Institute
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• v.18 no.1 s.91
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• pp.117-124
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• 2006

The effects of binder content and recycling mixed waste plastics(PA) content on the workability, work life and hardening shrinkage of fresh polymer concrete using mixed waste plastics are examined. As a result, the workability of the polymer concretes using mixed waste plastics tend to improve with increasing binder content, PA content and filler content. The work life of the polymer concretes using mixed waste plastics is shortened with an increase in the initiator content and curing temperature. The length change of the polymer concretes using mixed waste plastics tend to increased with Increasing binder content and PA content. The result of the present research is expected to make a contribution to the recycling of final mixed waste plastics and the continuing efforts for the development of use of the recycled products are thought to expand the horizon for the recycling of the final mixed waste plastics.