In order to make high-purity ferro-manganese from Mn3O4 waste dust, the application of aluminothermite process to the reduction of the waste dust was investigated. The mixture from Mn3O4 dust as metallic source and Al metal powder as the reductant ignited, and reduced with an extremely intense exothermic reaction. The rapid propagation of the aluminothermite reaction occurred spontaneously and stably by ignition of the mixture. The Manganese having some alloy elements emerged as liquids due to the high temperatures reached up to about 2,500℃ and separated from the liquid by their differences of specific gravity. The result of thermite reaction showed the fact that can be obtained high purity ferro-manganese which have over about 90% of manganese content and lower impurities such as C, P, S than those of KS D3712 specification. The recovery of manganese from Mn3O4 dust was lower level of about 65% than about 75% from manganese ore by electric furnace process, that is due to spatter loss because of its extremely intense thermite reaction. But it will be improved by the process designed to provide CaO as the cooler or to use the Al metal powder having larger particle size distribution.
Cationic gemini-surfactant, namely 1,4-butane-bis(N-alkanoyloxyethyl-N,Ndimethyl)-diammonium bromide was synthesized and their inhibition effect on corrosion of mild steel in 1 M HCl solution was tested by weight loss method. The synthesized product was confirmed by FT-IR and 1H-NMR spectroscopy. Surface tensions were measured by surface tensiometer Sigma 70. Their c.m.c. values evaluated by surface tension method was 4.1×10-5~5.4×10-5 mol/L. The Krafft point of the these surfactants were 〈0~10.7℃. The emulsifying properties of synthesized cationic gemini surfactants and sodium dodecyl sulfate (SDS), tetradecyl trimethyl ammonium bromide (TTAB) was investigated. Of these, 1,4-butane-bis(N-lauroyloxyethyl-N,N-dimethyl)- diammonium bromide, CGL 14-4-14 has been confirmed as a good emulsifier. The inhibition efficiency increases by increasing cationic gemini surfactant concentration. As a result, these surfactants are expected to be applied as corrosion inhibitors.
In this study, by using oleic acid and polypropylene glycol, good natured antifoaming agent for suitable electronics process under the alkaline conditions were synthesized. For the synthesized mono and diesters, acid value, hydroxyl value was measured, and identified by FT-IR and 1H-NMR spectroscopy. Surface properties such as surface tension, critical micelle concentration(cmc) for diluted aqueous solution was measured, and tested the antifoaming properties according to the difference of alkyl chain length, various concentration, temperature and pH. The surface tension of synthesized antifoaming agent, PPMO(Polypropylene glycol monooleate) was 24.3 dyne/cm, PPDO(Polypropylene glycol dioleate) was 23.7 dyne/cm. By increasing of the alkyl chain length, surface tension was decreased slightly, and showed good antifoaming properties at 0.06 wt% concentration and 50℃, pH 11. These synthesized compounds are expected to apply as a suitable antifoaming agents in the semiconductor and the PCB(Printed Circuit Board) manufacturing process.
The author previously reported that the addition of inuloprebiotics to broiler diets produces growth performance that is superior to antibiotic supplementation. The present study furthered this work by evaluating the quality with thiobarbituric acid reactive substances (TBARS) of the meat from chickens fed inuloprebiotics produced using Korean Jerusalem artichoke. Male Ross 308 broilers (n=240) were randomly allotted to a 35 day regimen of dietary control (no supplementation), dietary antibiotics supplementation (8 mg avilamycin/kg diet), or dietary inuloprebiotic supplementation (450 mg inuloprebiotics/kg diet). The pH, water holding capacity, L*value (lightness), and b*value (yellowness) of the chicken meat weres ignificantly higher in the inuloprebiotic group. The TBARS value of chicken meat stored at low temperature tended to increase according to the length of storage, and was significantly lower in the inuloprebiotics group. The sensory scores of the cooked chicken meat were significantly higher in the inuloprebiotics group. The results indicate that the addition of inuloprebiotics as anantimicrobial agent to broiler diets can greatly improve the quality and self-life with reducing TBARS of chicken meat.
To develope new natural substances for whitening agent, Baeckji(Angelica dahuria;BK), Seasin(Asarum sieboldii;SS). Baecjgangjam(Bombycis corpus;BGJ) and Mynkanbang(MKB) were selected and extracted by hot water and 70% EtOH, respectively. Hydrothermal and ethanolic extracts of BK, SS, BGJ and MKB were evaluated for anti-oxidative effect, tyrosinase activity, melanogenesis of B16 melanoma cells and changes in level of tyrosinase expression by using Western blotting. All hydrothermal and ethanolic extracts showed scavenging activities of free radicals against 1,1-diphenyl-2-picrylhydrazyl(DPPH) but no inhibitory effect on tyrosinase activity. Ethanolic extracts of BK, SS, and BGJ and especially highly, those of MKB inhibited production of melanin in B16 melanoma cells and were able to reduce the level of tyrosinase expression in B16 melanoma cells. These results suggest that ethanolic extracts of BK, SS, BGJ and MKB can be an effective whitening agent from natural plant.
Transdermal drug delivery(TDS) offers many important advantages. For instance, it is easy and painless, it protects the active compound from gastric enzymes, and it avoids the hepatic first-pass effect. Also, it is simple to terminate the therapy if any adverse or undesired effect occurs. But skin is a natural barrier, and only a few drugs can penetrate the skin easily and in sufficient quantities to be effective. Therefore, in recent years, numerous studies have been conducted in the area of penetration enhancement. The most commonly used transdermal system is the skin patch using various types of technologies. Compared with other method of dosage, it is possible to use for a long term. It is also possible to stop the drug dosage are stopped if the drug dosage lead to side effect. Polysaccharide, such as xanthan gum and algin were selected as base materials of TDS. Also, these polymers were characterized in terms of enhancers and drug contents. Among these polysaccharide, the permeation rate of Paroxetine such as lipophilic drug was the fastest in xanthan gum matrix in vitro. We used glycerin, PEG400 and PEG800 as enhancers. Since dermis has more water content(hydration) than the stratum corneum, skin permeation rate at steady state was highly influenced when PEG400 was more effective for lipophilic drug. Proper selection of the polymeric materials which resemble and enhance properties of the delivering drug was found to be important in controlling the skin permeation rate.
The analysis of reaction kinetics provided that the reaction order was the 1st of triglyceride and the rate constant was 0.067 min-1. The transesterification of camelina oil using 0.6 wt% mixed catalyst which consists of 40 v/v% of potassium hydroxide (1 wt%) and 60 v/v% of tetra methyl ammonium hydroxide (0.8 wt%), was carried out at 65℃ on the tubular reactor packed with static mixer. The conversion was shown to be 95.5% at the 6:1 molar ratio of methanol to oil, flow rate of feed of 3.0 mL/min and 24 of element of static mixer. The volume of washing water emitted by 0.6 wt% mixed catalyst was the half of the volume emitted by 1 wt% potassium hydroxide.
Carbon nanotube(CNT) plays an essential role in various fields of nano based science and technology. Recently, silica coated CNT composites are interested because they are useful for the optical, magnetical, and catalytic applications. In this report, carboxyl groups were introduced on the MWCNT using nitric acid. In order to maximize the silica encapsulation efficiency, carboxyl groups of MWCNT reacted with a silane coupling agent were used to prepare silica coated MWCNT. Due to their strong interaction between modified MWCNT and TEOS. Silica layer with a controllable thickness was achieved. Silica coated MWCNT were further utilized as the template for the synthesis of hollow silica nanotubes after 800℃ calcination.
Coumarin derivatives were shown to possess valuable pharmacological properties such as anticancer/anti carcinogenic, anti-inflammatory, anti helicobacter, anti genotoxic, neuroprotective and dietary effect. In this study, novel coumarin derivatives structurally related to 7-geranyloxycoumarin were effectively synthesised in good yields by Cs2CO3/acetonitrile in mild condition. The synthesis of geranyloxycoumarin derivatives in weak base(Na2CO3, K2CO3, Cs2CO3 etc)/CH3CN at room temperature obtained in good yield. On the other hand, the reaction of geranyloxycoumarin formation in strong base(NaOH, KOH, CsOH etc)/CH3CN at reflux condition obtained in low yield.
In this study we experimented that how chain extension influences to waterborne urethane-acrylic hybrid resin for leather garment coatings. We knew that polyurethane-acrylic hybrid resins had 5 grades of solvent resistance. Tensile strength measured in the polyurethane-acrylic resin(EDA 5.37 g, 1.928 kgf/mm2) had the most strong strength. Also polyurethane-acylic hybrid resin(EDA 5.37 g. 30.2 mg. loss) had better result than other hybrid resins. EDA contents higher, we obtained low elongation and low flexibility. In this result, chain extension of waterborne polyurethane-acrylic hybrid resin showed the effect in leather coating with ratio of EDA.
Displacement current measuring technique has been applied on the study of polyamic acid monolayer containing p-nitroazobenzene. The displacement current was generated from monolayer on the water surface by monolayer compression and expansion. Maxwell displacement current(MDC) was generated when the area per molecule was about 200a2 and 70a2. Maxwell displacement currents were investigated in connection with monolayer compression cycles. It was found that the maximum of MDC appeared at the molecular area just before the initial rise of surface pressure in compression cycles. The monolayer surface morphology of the LB film have been measured by Atomic Force Microscope(AFM). As a result, we confirmed that the microscopic properties of LB film by AFM showed the good orientation of monolayer molecules and the thickness of monolayer was 3.5-4.1nm.
In this study, we evaluated the anti-oxidative, whitening and anti-wrinkle effect of Tetrapanax papyriferum extract. Tetrapanax papyriferum was extracted by two different solvents which were n-Hexane, ethyl acetate. The anti-oxidant activity was measured by free radical scavenging activity using DPPH (1,1-diphenyl-2-picrylhydrazyl radical). And the inhibitory activities of tyrosinase for whitening effect and collagenase, elastase for anti-wrinkle were investigated. For anti-oxidant activity, ethyl acetate fraction of Tetrapanax papyriferum extract showed more significant activity than n-Hexane fraction of Tetrapanax papyriferum extract. For whitening activity, n-Hexane fraction of Tetrapanax papyriferum extract exhibited strong inhibition effects compared with reference. Therefore, Tetrapanax papyriferum extract may be useful as a new antioxidant and whitening agent.
The electrochemical characteristics of electric double layer capacitor(EDLC) were investigated using various carbon materials. The physical properties such as specific surface area and mean pore size of activated carbon were analyzed by BET. The results of the activated carbon used for electrode material showed that the specific surface areas varied from 600 to 1500 m2/g and mean pore sizes from 1.74 to 2.88 nm. A maximum specific capacitance of 0.30 F/cm2 was obtained for the activated carbon with the highest specific surface area and ionic conductivity. Also, it was found that the electrochemical results of the cyclic charge-discharge tests were stable.
Fabric fibrous filter has been used in various industrial applications owing to the low cost and wide generality. However, the basic properties of fabric materials often limit the practical utilization including hot gas cleaning. This study attempts to find new coatings of porous fibrous filter media in order to overcome its insufficient thermal resistance and durability. Teflon was one of the plausible chemicals to supplement the vulnerability against frequent external thermal impacts. A foaming agent composed of Teflon and some organic additives was tentatively coated on the glass fiber mat. The present test Teflon foam coated filter was fount to be useful for hot gas cleaning, up to 250℃-300℃. Close examination using XPS(X-ray Photoelectron Spectroscopy) and Contact angle proved the binding interactions between carbon and fluorine, which implies coating stability. The PTFE/Glass foam coated filter consisted of more than 95% (C-F)n bond, and showed super-hydrophobic with good-oleophobic characteristics. The contact angle of liquid droplets on the filter surface enabled to find the filter wet-ability against liquid water or oil.
UV-Curable hybrid coatings were synthesized to improve the surface properties of plastic film. Organic-inorganic coating solutions were prepared by the sol-gel method using urethane-acrylate oligomer, acrylate monomer, photo initiator and tetraethoxysilane (TEOS). Methacryloyloxypropyltrimethoxysilane(MPTMS) was used as a silane coupling agent to improve chemical interaction between inorganic phases and UV curable acrylate. In this study, the surface hardness and adhesive properties were improved with the use of inorganic component. The experimental results showed that UV-Curable hybrid films containing aliphatic urethane oligomer, hexanedioldiacrylate, trimethylolpropanetriacrylate, hydroxy dimethyl acetophenone exhibited good surface properties. Also, the optimum curing conditions were investigated.
The excess volumes of mixing of benzyl alcohol and halothane in vesicle and in suspensions of several lipids have been determined at 25℃ it using a excess volume dilatometer. The potency of general anesthetics has long been known to correlate with lipid solubility. Denaturations of the vesicle, which is a sole membrane protein in the purple membrane of Halobacteriun Halobium, were studied by absorption changes at 280 nm and fluorescence changes at 330 nm and excess volume dilatometer. The particle size analysis of viscous polymer solutions by diffusional interchange is the key step by measurement. The excess volume of mixing in chitosan was found to be negative, whereas them of purple membrane, Halobacteriun Halobium and red membrane were positive in benzyl alcohol and halothane. This result was confirmed as Miller's supposition.
The processes for the preparation of ZnO powder by using EAF(electric arc furnace)dust was studied by wetting method which are divided to two steps, carried out of the elution processes by various concentrations of sulfuric acid is reacted with EAF dust as the former, and the latter were performed by a number of specified processes, which are leaching process depends on various pH, cementation, ozone and heat treatment processes etc. Experimental results showed that the appropriate pH range is pH7.5~8.0 and the resulting zinc content is range of 37~38%, the residual quantities of the heavy metals are less than 3ppm individually by cementation process except Mn, even though the Mn metal could not be removed by cementation process but was removed up to 0.2ppm by the ozone process from 70ppm initially. Finally, 80.2% of ZnO was obtained by the heat treatment at 500℃.