• Journal of Korea Foundry Society
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• v.28 no.5
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• pp.237-241
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• 2008

This study has been carried out to investigate the wear and heat resistant properties of durable moldwash agent for Al gravity casting according to mold washing process conditions. The wear properties of coated specimen were performed by sliding wear testing machine and heat resistance were evaluated by measuring the loss of coated moldwash agent during emerging of coated specimen in Al melts. During testing, experimental variables were mold surface temperature, moldwash agent/distilled wear, and additive concentrations. The lower additive concentration and mold temperature caused the smooth surface roughness of coated specimen, It was found that the specimen coated with moldwash/water ratio 1:3, additive concentration 9wt% and mold temperature higher than $200^{\circ}C$ showed superior wear and heat treatment. Also, these results were supported by fluidity test.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.7
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• pp.942-946
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• 2004

This study aimed to examine the fermentation quality of a tropical Elephant grass (Pennisetum purpuereum) and temperate Italian ryegrass (Lolium multiflorum) forages ensiled additive of fermented juice of epiphytic lactic acid bacteria (LAB) and to determine what factor affects the fermentation characteristics of the crops. In both species cell walls neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents in silages were consistently decreased (p<0.05) with the addition of FJLB at ensiling more then Control treatment. The FJLB additive increased number of LAB (cfu) and lactate concentration in the silages in both species. The Control treatment without additive underwent a clostridial type of fermentation with traces of propionic, iso-butyric, n-butyric acids contents with higher (p<0.01) levels of volatile basic nitrogen (VBN %TN) and had appreciable decreased of nutrient in silages. FJLB treatment improved silage nutritive value with little contents of VBN %TN, ethanol and very small amount of dry matter (DM) and hemicellulose losses (p<0.05) between 2 to 5% and 7 to 3% respectively, in Elephant grass and Italian ryegrass species. The results in this study indicates that while among the factors affecting silage fermentation butyric type of fermentation was more pronounced in tropical elephant grass compared to the temperate Italian ryegrass, FJLB additive revealed a better silage fermentation products in both species.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1361-1363
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• 1997

Zinc oxide-based MOV was fabricated with $SiO_2$ additive ranging from 0.5 to 4.0 mol%, and the microstructure and electrical characteristics were investigated. $Zn_2SiO_4$ phase formed by $SiO_2$ additive was distributed at ZnO grains, grain boundaries, and multiple grain junctions. As the content of $SiO_2$ additive increases, average grain size decreased from 40.6 to $26.9{\mu}m$ due to the Pinning effect by $Zn_2SiO_4$ at grain boundaries Breakdown voltage and nonlinear exponent increased, and leakage current decreased in the range of $11.2{\sim}6.14{\mu}A$ with an increasing $SiO_2$. Donor concentration and interface state density decreased, and barrier height increased in the range of $0.71{\sim}1.04eV$ with an increasing $SiO_2$. While, as the content of $SiO_2$ additive, apparent dielectric constant decreased, peak frequency of dissipation factor decreased in the range of $6.45{\times}10^5{\sim}3.00{\times}10^5Hz$, and dissipation peak was $0.31{\sim}0.22$ at Peak frequency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.357-360
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• 1995

Since the streaming electrification phenomena of transformer were made clear on 1970s, many researches have been continued on the improvement of the transformer. This paper describes the effect of additive (BTA, DBPC) and temperature on the streaming electrification of the various materials. The streaming current in the various materials decreases in proportion to the concentration of BTA, results in the inverse electrification. We believe that these results will contribute to the optimal design of HV large-capacity transformer.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.927-930
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• 2013

We developed an electroplating process of cobalt nanowires of which line-widths were between 70 and 200 nm. The plating electrolyte was made of $CoSO_4$ and an organic additive, dimethyldithiocarbamic acid ester sodium salt (DAESA). DAESA in plating electrolytes had an accelerating effect and reduced the surface roughness of plated cobalt thin films. We obtained void-free cobalt nanowires when the plating current density was 6.25 mA/$cm^2$ and DAESA concentration was 1 mL/L.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.11a
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• pp.106-109
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• 2003

With the variation of Ag concentration in bath, current density, additive and agitation for electroplating of Sn-Ag solder, the compositions and the morphologies of solder were studied. It was possible to control Ag content in Sn-Ag solder by varying Ag concentration in bath and current density The microstructure size of Sn-Ag solder decreased with increasing current density. Duty cycle of pulse electroplating and quantity of additive affected on Ag content of deposit and surface roughness. In this work eutectic Sn-Ag solder bumps with fine pitch of 30m and height of 15m was formed successfully. The Ag content of electrodeposited solder was confirmed by EDS and WDS analyses and the surface morphologies was analyzed by SEM and 3D surface analyzer.

• 한국연소학회:학술대회논문집
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• 2003.12a
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• pp.209-214
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• 2003

Numerical simulations are performed at atmospheric pressure in order to understand the effect of additives on flame speed, flame temperature, the radical concentration, the NOx formation in freely propagating $CH_4/O_2/N_2$ flames. The additives used are carbon dioxide and hydrogen chloride which have a combination of physical and chemical behavior on hydrocarbon flame. In the flame established with the same mole of methane and additive, $CO_2$ addition significantly contributes toward the reduction of flame speed and flame temperature by the physical effect, whereas addition of HCl mainly does by the chemical effect. The impact of HCl addition on the decrease of the radical concentration is about 1.6-1.8 times as large as $CO_2$ addition. Hydrogen chloride addition is higher on the reduction of EINO than $CO_2$ addition because of the chemical effect of HCl.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.105-111
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• 2005

An experimental study is performed for extinguishing of n-heptane pool fire by water mist containing potassium acetate as a fire suppression additive. Water mist was generated by a single pressure nozzle in a small-scale chamber. The drop size distribution of water mist was measured using laser diffraction(Malvern particle sizer). The flame temperature, oxygen concentration and carbon monoxide concentration were measured. In case of using additives, the fire extinguishing time was shorter than that of pure water at a given discharge pressure and it was because the momentum of a water droplet containing additives was increased. And also dissociated metal atoms, potassium, were reacted as a scavenger of the major radical species OH, H which were generated for combustion process. Moreover, at a high pressure of 4MPa, the fire was extinguished through blowing effect as well as primary extinguishing mechanisms.

• Journal of the Korean Society of Safety
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• v.19 no.2
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• pp.61-68
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• 2004

The evaporation phenomena of waterr droplet which has sodium acetate trihydrate($CH_3COONa{\cdot}3H_2O$) as a fire suppression additive were studied. Solutions of sodium salt up to 50% and heated stainless-steel surface were used in the experiment. The evaporation process was recorded using a charge-coupled-device camera at 120 frames per second. The average evaporation rate of the sodium acetate trihydrate soluation was lower than that of pure water at a given surface temperature and decreased with the concentration increase due to the precipitation of salt in the liquid film and change of surface tension. The variation of liquied film diameter was measured by time and it was increased by the hot surface temperature increase.

• Journal of Pharmaceutical Investigation
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• v.35 no.2
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• pp.81-87
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• 2005

We have prepared karaya gum patches containing ketoprofen and investigated the effect of short-time current pretreatment of skin on the permeability. Hairless mouse skin was treated with current before the patch was mounted on the skin. The effect of current density and current duration on the flux of ketoprofen was studied. The possibility of additive effect with penetration enhancer (PGML) was also investigated. Iontophoretic pretreatment of skin increased the passive flux up to 3 folds at 0.4 $mA/cm^2$ current density, when the matrix contained no PGML. As the duration of current-pretreatment and current density increased, flux increased. PGML increased the average passive flux markedly, about 6 to 12 folds, depending on the concentration in the patch. Current pretreatment further increased the flux from this PGML containing patch, exhibiting additive effect. These results indicate that short-duration current pretreatment of skin can be an useful method for the enhancement of ketoprofen permeability through skin.