• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.3
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• pp.203-211
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• 2007

This study was conducted in cut rose cultivation field in Goyang to evaluate pesticide exposure of farmers and the relationship between the exposure and work environment/method for cut rose farmers. Dermal exposure was assessed with patch (thin chromatography layer paper), cotton glove by body parts during mixing and spraying works in which pyrethroid, organophosphate, carbamate pesticide were used in 4 cut rose greenhouses located in Goyang province, checking characteristics of environment/working method at the same time. Body parts assessed were as follows ; glove : hand, patch : head, neck(front/back), chest, back, shoulder(right/left), upperarm(right/left), forearm(right/left), thigh(right/left), shin(right/left). Pesticides were analyzed using gas chromatography(NPD/FID) after extracting with ethyl acetate. Exposure amount differed according to pesticide type. But after standardizing with total net weight of pesticide sprayed, there were no significant difference among pesticides. There were significant difference in exposure amount among body parts(especially exposure amount of thigh, shin were more than the others), which means exposure happen not by pesticide dispersion in air but by contact with cut rose(leaf, branch) indirectly. Walking forward during spraying made farmers more exposed than waling backward, these results means contacts with leaves/branches made exposure happen in cut rose greenhouse also. As a result, pesticide exposure in cut rose greenhouse was related with contact of leaf/branch which pesticide remained in, which made exposure pattern (especially exposure amount) differ by body parts

• Journal of the Microelectronics and Packaging Society
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• v.13 no.3 s.40
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• pp.33-38
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• 2006

Aerosol slurry composed of dielectric materials, distilled water, and deflocculants was sprayed on the substrates, through a high-pressure spray gun as an aerosol. The coated layers were cofired together with $Al_{2}O_{3}$ substrates and green sheets on which the inner connectors were printed. Although the coating rate of coated layers strongly depended on slurry viscosity, spray shape, and the pressure of the spray gun, the coated density was not changed. Buried conductors were maintained as printed by high pressure spray coating method, because the pressing process was not used. At the optimum condition of air controller step 3-4 and slurry viscosity c.p 2000-4000, dense and uniform layers could be achieved. Comparing with conventional lamination process using green sheets, spray coating method enabled thin dielectric layers of $20{\sim}50{\mu}m$.

• Journal of the Korean Ceramic Society
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• v.13 no.1
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• pp.25-29
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• 1976

The properties vary with quality of ferric-oxide that is major material of ferrites. In this point of view, a manufacturing method of pure and homogeneous fine ferric oxide is very important. The characters of this study are as follows: 1) Ferric oxide was made from waste pickling liquor of steel. 2) The crude ferric-oxide that is made by roasting the pickling liquor was dissolved in 20% HCI solution and then produced ferric chloride is purified by ethyl ether extraction. 3) The methanol solution of purified ferric chloride was sprayed into the refractory tube with compressed air and propane gas and then ignited leading to the ferric-oxide powder. 4) The produced oxide powder was introduced to the scrubber type vessel throught cooling system in order to collect the powder. 5) Crystalline phase of the powder was identified by X-ray diffraction and particle size, crystalline shape of the powder were investigated by settling method and electron microscope and the effects of concentration of ferric chloride in methanol on grain size were discussed. Results were obtained as fellows: 1) Total impurity in the ferric oxide produced from waste pickling liquor was 3.7%. 2) The solubilityof crude ferric oxide that was made from waste pickling liquor in HCI solution increased with the HCI concentration and reached to saturation range at 15% HCI concentration. 3) Extraction of FeCl3 increased with HCI concentration which is solvent. 4) Alpha ferric oxide obtained was very fine crystalline particles, the mean crystalline grain increased with the concentration of ferric chloride, and mean grain size distributed from 3.5$\mu$(at 0.5mole/l) to 0.5$\mu$(at 0.05mole/l).

• KSBB Journal
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• v.22 no.3
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• pp.151-156
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• 2007

Increasing public concerns over odors and air regulations necessitates the remediation of a wide range of odorous compounds for industrial purpose. Currently, wet scrubbing technique by neutralization using essential oils is utilized to treat methyl mercaptan odor. The chemical analysis is performed to analyze the composition of an essential oil by GC-MS. The objective of this study is to clarify the possibility of the neutralization of odors sprayed in the fixed bed and determine the removal efficiencies in the misty aerosol by different input odor concentration. It is found that methyl mercaptan is significantly removed in the wet scrubber, and their removal efficiency of methyl mercaptan is obtained by 98%.

• Journal of the Korean Society of Clothing and Textiles
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• v.17 no.1
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• pp.151-161
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• 1993

The purpose of this study was to investigate the effect of hydrophilic finish for polyester (PET) fabric and hydrophobic finish for cotton fabric on the water transport and comfort properties. Polyester fabric was treated with 10% sodium hydroxide solution to impart hydrophilicity. Cotton fabric was sprayed with Scotch-gard$^{(R)}$ water and oil repellent finish to impart hydrophobicity. Porosity, air permeability, contact angle, wickability and water vapor transport rate (WVTR) were measured to determine the water transport properties of fabrics. To compare the comfort properties of treated and untreated fabrics, wear test was performed by putting fabric patches on the upper back: stratum corneum water content (SCWC), subjective wettedness and comfort rating were determined. The results were as follows: (1) The contact angle of water on treated polyester fabric was decreased and that of treated cotton fabric was increased. Also, the wickability of treated polyester fabric was increased and the wickability of cotton fabric was decreased. (2) Although each finish did not change porosity, the water vapor transport rate of treated polyester fabric was increased and that of treated cotton fabric was decreased slightly. (3) The results of stratum corneum water content measurements showed good agreement with the results of the contact angle and the wickability, i.e., the better the liquid water transport properties are, the less the stratum corneum water contents were resulted. (4) The realtionship of subjective wettedness or comfort and stratum corneum water content was independent. Therefore, it was concluded that human perception on the subjective wettedness or the comfort is affected by the skin contact of wet fabric rather than by the stratum corneum water content.

• Applied Chemistry for Engineering
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• v.25 no.4
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• pp.386-391
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• 2014

Atmospheric-pressure nonthermal corona discharge plasma was applied to the sterilization of biologically contaminated scoria powder. Escherichia coli (E. coli) culture solution was uniformly sprayed throughout the scoria powder for artificial inoculation, which was well mixed to ensure uniformity of the batch. The effect of the key parameters such as discharge power, treatment time, type of gas and electrode distance on the sterilization efficiency was examined and discussed. The experimental results revealed that the plasma treatment was very effective for the sterilization of scoria powder; 5-min treatment at 15 W could sterilize more than 99.9% of E. coli inoculated into the scoria powder. Increasing the discharge power, treatment time or applied voltage led to an improvement in the sterilization efficiency. The effect of type of gas on the sterilization efficiency was in order of oxygen, synthetic air (20% oxygen) and nitrogen from high to low. The inactivation of E. coli under the influence of corona discharge plasma can be explained by cell membrane erosion or etching resulting from UV and reactive oxidizing species (oxygen radical, OH radical, ozone, etc.), and the destruction of E. coli cell membrane by the physical action of numerous corona streamers.

• Journal of the Korean institute of surface engineering
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• v.30 no.4
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• pp.272-280
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• 1997

The Thermal Barrier Coation(TBC) to improve the that barrier and wear resistant propenrty in high temperature ofthe aircraftength between the accumlation of the aircraft engine and the automobile engine has usually the two layer structure. One is a creamic top layer for heat insulation and the other is a metal bond layer to facilitate the bond strength between the top ceramic layer and the substrate. But, the coated layers should be peeled off because of the accumulation of the thermal stress by the differance of the thermal expantion coefficient between metal and ceramics in a hrat cyclic environment. In this study, the intermediate layer by plasm spray process was introduced to reduce the thermal stress. The powders of plasm spray coating were the Yttria Stabilized Zirconia (YSZ), the Magnesia Stabillized Zirconia(MSZ) and NiCrAlY. the intermediate layer was sprayed with the powders of the bond cast for the purpose of test were executed. The high temperature wear resistance tends to decreasnceee wear and thermal shock test were exeucuted. The high temperature were resistance of the YSZ TBC is better that of the MSZ TBC. The wearrsistance tends to decrease accoring to incresing the temperature between $400^{\circ}C$to $600^{\circ}C$. The thermal shock life of the 3 layer TBC with YSZ top casting was the most outstanding thermal shock rsisstasnce. This means that the intermediate layer should play an importnat roll to alleviate the diffrerence of the thermal expansion coef frcients between metallic layer and cermics layer.

• Journal of the Korean Ceramic Society
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• v.30 no.4
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• pp.325-331
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• 1993

Aqueous solutions of metallic salts, ZrO(NO3)2.2H2O and Y(NO3)3.5H2O were used as raw materials to synthesize crystalline submicron spherical powders of Zr0.94Y0.06O1.97 with tetragonal crystal phase. Each aqueous solution was mixed on the magnetic stirrer to homogenize for 12 hours. The concentration of the mixed solutionwas changed from 0.01mol/$\ell$ to 0.1mol/$\ell$ calculated as the concentration of Zr0.94Y0.06O1.97. Ultrafine droplets of starting mixed solution were sprayed by the ultrasonic vibrator and carried into the furnace kept at 55$0^{\circ}C$, $650^{\circ}C$, 75$0^{\circ}C$ and 85$0^{\circ}C$ using carrier gas of air (10$\ell$/min) and pyrolysed to form Y-TZP fine powders. The results of this exeriment were as follows. 1) Synthesized powders were nonagglomerated and spherical type. 2) Particle size distribution was narrow between 0.1${\mu}{\textrm}{m}$ and 1${\mu}{\textrm}{m}$. 3) Forming reaction Y-TZP was finished above synthetic temperature 75$0^{\circ}C$. 4) As the synthetic temperature rised from 55$0^{\circ}C$ to 85$0^{\circ}C$, the mean particle size decreased from 0.35${\mu}{\textrm}{m}$ to 0.22${\mu}{\textrm}{m}$ in the concentration of starting solution with 0.02mol/$\ell$. 5) At 75$0^{\circ}C$ of synthetic temperature, the concentration changes of starting solution from 0.01mol/$\ell$ to 0.1mol/$\ell$ increased the mean particle size from 0.24${\mu}{\textrm}{m}$ to 0.38${\mu}{\textrm}{m}$. 6) Chemical compositions of each synthesized particle were homogeneous nearly.

• Asian Journal of Turfgrass Science
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• v.10 no.3
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• pp.263-270
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• 1996

This experiment was conducted to investigate the loss of various herbicides by means of vola-tility from the turfgrass field and the hare ground with the different soil moisture contents and temperatures. Different herbicides were applied at the rates of 375 g a.i. /l0a of pendimethalin,250 g a.i. /l0a of napropamide, and 96.4 g a.i. /l0a of dicamba with 200 \ulcorner/10a of spray volume in the turfgrass(Zoysia japonica cut off 5cm) grown in pots(265.8 $cm^2$) and bared soil. The pots were placed in the growth chamber with 10,000 lux of light intensity(12h per day) at 25 and 35˚C for 7days. Amberlite XAD polymeric resin(20/50 mesh) was used as sampling media for herbicide airborne residues. Air flow was maintained at 10 \ulcorner /min by vacuum pump regulated with a factory calibrated flow meter. Herbicide airborne residues were extracted from the XAD resin with 300 ml of 1:1 acetone and hexane. The extracts were concentrated by rotary evaporation at 35˚C and dissolved in 1 ml MeCN for HPLC analysis. The airborne losses of the herbicide applied in the turfgrass and bare soil increased as the temperature and soil moisture contents were increased, regardless of the kinds of herbicide. Higher airborne residues was observed in the turfgrass pots than the bare soil pots. Pendimethalin and dicamba with higher vapor pressure gave rise to the increased loss of airborne herbicides, showing that 6.26 and 6.4% of average airborne loss in pendimethalin and dicamba, respectively, compared to 0.56% in napropamide. The amount of airborne losses in turfgrass was highest at one day after application and then a declined trend was observed as the time was prolonged. Key words. Herbicides, Turfgrass field, Bare ground, Volatility.

• International Journal of Advanced Culture Technology
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• v.3 no.2
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• pp.15-24
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• 2015

Currently, abundant wastes from the palm oil refining process have been generated which are hard to handle. Spent Bleaching Earth (SBE) is the solid waste from this process and leads the cost of elimination to the company. This study aims to utilize the SBE as the alternative material in the non-fired wall tiles. The main raw materials used in non-fired wall tiles consist of laterite soil, fluvial sand, and Portland cement. The experimental formulas have been conducted and divided into 3 groups by varying the percentage of the SBE in main raw materials. The specimens of material mixture have been produced by uniaxial pressing at 100 bars, dimensions in $50{\times}100{\times}8mm$. These specimens are sprayed with water and cured in the air for 7 days. After that, bending strength and water absorption test of these specimens has been performed. It can be concluded that the best formula with the percentage of laterite soil, fluvial sand, Portland cement, and SBE are 60.94%, 13.125%, 22.5%, and 3.435%, respectively. Its bending strength and %water absorption are 0.68 MPa and 5.64%. Material costs of specimen are approximately $0.00276 USD/100g. Furthermore, the comparison of curing period between 7 days and 30 days has been performed. The 30 days of curing period can improve the bending strength of the specimen, but there is no effect on water absorption.