• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.11a
• /
• pp.77-78
• /
• 2018

Form-work is a must for construction work. In order to secure the best condition of the form surface and to increase the number of times, the form releasing agent is applied during the process of the form-work. The base oil of the form release agent which has been used already uses the oil which directly or indirectly affects the natural environment and the concrete. In this study, the basic study on the form release agent for concrete was carried out only for the effect of adhesion. The adhesive force of the tile is measured by the mortar to determine the change of the releasing agent and the adhesive strength.

• Journal of Adhesion and Interface
• /
• v.12 no.4
• /
• pp.144-150
• /
• 2011

The effect of low profile agent and release agent on the surface and mechanical properties of bulk mold compound were investigated. Atomic content and contact angle of surface were characterized using X-ray photoelectron spectroscopy and contact anglemeter. Surface morphology and surface roughness were obtained using field emission scanning electron microscope and atomic force microscope, respectively. As increasing the low profile agent from 0 to 9.2 wt%, the volume shrinkage and surface roughness decreased from 0.35% to 0.05%, and from $0.27{\mu}m$ to $0.12{\mu}m$, respectively. The increase of release agent from 1.8 wt% to 3.6 wt% resulted in the migration of release agent to sample surface and it increased the surface roughness. The flexural strength and impact strength were decreased approximately 30% as the low profile agent increasing from 5.0 wt% to 9.0 wt%.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.11
• /
• pp.610-616
• /
• 2020

Recently, the application of a photocatalyst to road structures is being attempted to solve environmental problems caused by fine particulate matter and automobile exhaust. The purpose of this study was to develop a release agent with GST (low-cost, high-performance photocatalyst produced from wastewater sludge). For this, the method of mixing and dispersing GST with the release agent was used first, and the removal performance of nitrogen oxide (NOx) was then checked. The best performance without a precipitation reaction was achieved using a stabilizing agent at 20 % in an outdoor exposure test for four weeks. The NO and NOx removal rate of the specimen demolded by applying the GST release agent developed in this study showed excellent effects of 200 to 400 % compared to the Plain material. To increase the performance of the GST release agent, it is necessary to improve the dispersibility of GST in the release agent and increase the amount of the nano-sized photocatalyst. In addition, the use of GST release agent in road structures and exposed concrete is expected to increase the NOx removal efficiency.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.787-788
• /
• 2012

• Journal of the Korean Chemical Society
• /
• v.65 no.5
• /
• pp.320-326
• /
• 2021

This study investigated the effect of the structure of the crosslinking agent used in contact lens polymerization on the physical properties and drug dissolution of contact lenses.es Contact lenses were manufactured using 0.3% and 3% of 4 types of crosslinking agents, respectively, and ofloxacin was used as the drug. Contact lenses using hydrophilic crosslinking agents improved water contents and wettability, and the more hydrophilic functional groups, the greater the effect. Contact lenses with a high concentration of crosslinking agent had a low concentration of eluted drug and a longer release time. The cross-linking agent structure of contact lenses had an effect on improving the performance of contact lenses and controlling drug release.

• Archives of Pharmacal Research
• /
• v.9 no.1
• /
• pp.39-43
• /
• 1986

Bovine serum albumin microspheres containing cytarabine were prepared using cross-linking agent, formaldehyde. The shape and the size distribution of them were observed. The shape of them was spherical and the susrface was compact and smooth. The size distribution of them was affected by dispersion forces during emulsfication. The release of cytarabine from albumin microspheres was dependent upon cross-linking time, amount of cross-linking agent and drug/albumin ratio. However, the difference of drug release by the dispersion forces was not great. After release test, the shape of albumin microspheres was nonspherical and the albumin matrix seemed to be a little relaxed. The degradation tests of albumin microspheres by the proteolytic enzyme showed that albumin microspheres were progressively digested according to the cross-linking degree.

• Journal of Pharmaceutical Investigation
• /
• v.41 no.4
• /
• pp.217-225
• /
• 2011

The aim of this work was to prepare porous osmotic pump tablets for controlled delivery of Aceclofenac. Aceclofenac solid dispersion was prepared to improve the solubility by using the drug - carrier (Mannitol) ratio of 1:1. The osmotic pump tablets were prepared using the solid dispersed product of Aceclofenac. The formulation contains potassium chloride as osmotic agent, cellulose acetate as semipermeable membrane, poly ethylene glycol (PEG 4000) as pore former and sodium lauryl sulphate (SLS) as solubility enhancer. The formulations were designed by the general factors such as osmotic agent and pore former. All formulations were evaluated for various physical parameters and, the in vitro release studies were conducted as per USP. The drug release kinetic studies such as zero order, first order, and Higuchi and Korsmeyer peppas were determined and compared. All the formulations gave more controlled release compared to the marketed tablet studied. Numerical optimization techniques were applied to found out the best formulation by considering the parameter of in vitro drug release kinetics and dissolution profile standards. It was concluded that the porous osmotic pump tablets (F7) composed of Aceclofenac solid dispersion/Potassium chloride/Lactose/Sodium lauryl sulphate/Magnesium Stearate (400/40/95/10/5, mg/tab) and coating composition with Cellulose acetate/ PEG 4000 (60/40 %w/w) is the most satisfactory formulation. The porous osmotic pump tablets provide prolonged, controlled, and gastrointestinal environment-independent drug release.

• Journal of Pharmaceutical Investigation
• /
• v.23 no.4
• /
• pp.207-211
• /
• 1993

Reservoir type devices were designed for long-term implantable drug delivery system. The reservoir type device was prepared with the polymethacrylic acid gel coated with polyurethane membrane. Release controlling agent (RCA) were employed to control drug release from devices via generation of micropores in the membranes. The polyurethane membrane functioned as a rate controlling barrier. The drug release pattern of hydrogel demonstrated zero order kinetics. The release rate of drugs could be regulated by varying hydrophobicity/hydrophilicity and content of the RCA, as well as the thickness of the polyurethane membrane. The release of drugs from this system was governed by pore mechanism via simple diffusion and osmotic pressure.

• Journal of Pharmaceutical Investigation
• /
• v.26 no.4
• /
• pp.273-280
• /
• 1996

Chondroitin sulfate/gelatin microspheres containing dexamethasone 21-acetate were prepared by complex coacervation method and their release patterns were examined in vitro. Microspheres prepared with a small amount of crosslinking agent had smooth surface and few pores, but those with a large amount of crosslinking agent were more porous and less spherical. In vitro release patterns were varied by changing polymer/drug weight ratio and amount of crosslinking agent. The release rate of dexamethasone 21-acetate in the presence of collagenase was faster than that in the absence of collagenase. Anti-inflammatory effect of dexamethasone 21-acetate microspheres was more efficient than that of dexamethasone 21-acetate solution in carrageenan-induced arthritis in the rat. On the basis of the above results, we might expect the degradation and drug release rate of these microspheres to be regulated by the degree of crosslinking and the level of enzymes. In patients with severe rheumatoid arthritis who have high concentration of collagenase, more drug would be released from the microspheres. An intra-articular injection therapy of rheumatoid arthritis with desired release kinetics could be developed to enhance patient compliance and therapeutic index.

• International Journal of Highway Engineering
• /
• v.9 no.2 s.32
• /
• pp.13-25
• /
• 2007

Viscosity, adhesion and cohesion of asphalt binder are very important characteristics in asphalt pavement. However, these characteristics can cause some problems such as inaccurate amount of asphalt mixture, reduction of asphalt content and loss of workability during asphalt pavement construction. Asphalt release agent has been used to solve these problems. Diesel oil and vegetable oil are generally used as an asphalt release agent in Korea. However, these agents have been criticized from environmental and binder integrity reasons. Therefore, this study evaluated the characteristics of asphalt release agents including diesel oil, vegetable oil and two emulsion type oils. From the study, it was found that the diesel oil resolved the binder within ten minutes and vegetable oil stripped the binder from mixture within one hour after contacting with asphalt mixture. And also, from the test for estimating the application cycle of asphalt release agent, it appears that diesel oil and vegetable oil should be applied to construction equipments every time in their uses. However, diesel oil and vegetable oil showed a good performance as a lubricant for detaching the asphalt mixtures from the truck bed.