• 한국조리학회지
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• 제23권8호
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• pp.98-105
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• 2017

The purpose of this study was to investigate changes in physicochemical properties of apples pre-treated differently with salt and sugar for apple Jangachi. When salt was used, moisture content was decreased by 28.41% to 57.67% at 24 hours and maintained an average 56.92% after 24 hours. However, when sugar was used, moisture content decreased steadily to 41.14% (60h). The pH of the apple pre-treated with salt decreased from pH 4.42 to pH 3.63 at 12 hours. However, in the case of apples pre-treated with sugar, pH decreased from pH 4.52 to pH 4.19 after 48 hours, but was not statistically significant. Conversely, total acidity of apple pre-treated with salt increased from 11.46% to 0.35% during 72 hours. But total acidity of apple pre-treated with sugar decreased to 0.11% at 24 hours and maintained. Sugar content of apple pre-treated with salt increased to 33.1% at 12 hours and maintained. Conversely, in case of sugar pre-treatment, sugar content of apple pre-treated with sugar increased steadily to 45.12% at 72 hours. Salinity of apple pre-treated with salt increased sharply to 15.74% during 24 hours. Lightness ($L^*$) of apple pre-treated sugar was not different from the control group. But apple pre-treated salt decreased slightly. Yellowness ($b^*$) was higher than the control group regardless of pre-treatment group. Sensory evaluation revealed that sugar pre-treatment apples were highly evaluated for flavor, taste, chewiness and overall acceptance.

• 한국지역사회생활과학회지
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• 제16권1호
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• pp.65-72
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• 2005

To increase dyeability of cotton fabric to the chestnut shell dyeing, we had several dyeing experiments with the experimental fabrics which was pre-treated by soybean, NaOH, KOH. Three kinds of experimental cotton fabrics were used and chestnut shell dyebath was made for the experiment. Munsell's color HV/C and color differences ΔE of dyeing fabrics were compared between pre-treatment and none pre-treatment dyeing fabrics. The main results were as follows ; Color differences of dyeing fabrics pre-treated with soybean, NaOH, KOH were higher than those of none pre-treated dyeing fabrics. In case of pre-treatment with soybean, the concentration of the soybean bath affected the color differences but not affected in case of pre-treatment with NaOH & KOH. Munsell's color of pre-treatment fabrics with soybean, NaOH, KOH were same with the none pre-treatment fabrics. Colorfastness of the pre-treated fabrics were same degree, but only in case of soybean pre-treated fabrics were low in fastness of washing(change) & perspiration(acidic change).

• 한국환경과학회지
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• 제12권4호
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• pp.469-476
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• 2003

In order to examine the pre-treatment effect of crab shell en Pb$^{2+}$ removal by crab shell in aqueous solution, acid and alkali pre-treated crab shell were used. Electron microscopy techniques such as TEM (transmission electron microscopy) and SEM (scanning electron microscopy), and EDX (energy dispersive X-ray) and FTIR (Fourier transform infrared) spectrometry techniques were used to investigate the process of Pb$^{2+}$ removal by acid and alkali pre-treated crab shell. The Pb$^{2+}$ removal by acid pre-treated crab shell was much lower than that by untreated crab shell because of the decrease of CaCO$_3$ from the crab shell. However, the Pb$^{2+}$removal by alkali pre-treated crab shell increased compared to that by untreated crab shell. The results were confirmed by TEM, SEM, EDX and FTIR.nd FTIR.

• 한국안전학회지
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• 제29권4호
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• pp.61-72
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• 2014

The aim of this study is to define the condition of optimal pre-treatment for preferable activated carbon fibers (ACFs), which are based on rayon fibers. This paper shows the ideal path of ACFs preparation process; implies that rayon fibers are pre-treated by various solvents with different times before the heating process. The pre-treated rayon fibers finally turned into desirable rayon fiber-based ACFs through optimal pre-treatment condition by heating processes. The thermal analysis method of pre-treated rayon fibers by thermo-gravimetry analyser (TGA) is an idealized tool, which analyzes the best thermal condition of pre-treatment process. Surface morphologies of resulting rayon fibers based ACFs were examined by scanning electron microscope(SEM). The results of TGA and SEM analyses show that the optimal pre-treatment condition for preparing ACFs was clearly defined, in terms of thermal stability and surface morphology.

• Environmental Engineering Research
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• 제12권1호
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• pp.1-7
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• 2007

Most of the herb residue producing from oriental medical clinics(OMC) and hospitals(OMH) is wasted in Korea. To develop of adsorbent for removing heavy metal from wastewater, the various pre-treatment methods of the herb residue were evaluated by potentiometric titration, Freundlich isotherm adsorption test and the kinetic adsorption test. The herb residue was pre-treated for increasing the adsorption capacity by cleaning with distilled water, 0.1 N HCl and 0.1 N NaOH and by heating at $370^{\circ}C$ for 30 min. It showed a typical weak acid-weak base titration curve and a short pH break like commercial activated carbon during photentiometric titration of pre-treated herb residue. The log-log plots in the Freundlich isotherm test were linear on the herb residue pre-treated with NaOH or HCl like commercial activated carbon. The adsorption capacity(qe) in the Freundlich isotherm test for $Cr^{6+}$ was 1.5 times higher in the pre-treated herb residue with HCl than in activated carbon. On the other hand the herb residue pre-treated with NaOH showed the good adsorption capacities for $Pb^{2+}$, $Cu^{2+}$ and $Cd^{2+}$ even though those adsorption capacities were lower than that of activated carbon. In kinetic test, most of heavy metals removed within the first 10 min of contact and then approached to equilibrium with increasing contact time. The removal rate of heavy metals increased with an increase of the amount of adsorbent. Likewise, the removal rates of heavy metals were higher in the herb residue pre-treated with NaOH than in that pre-treated with HCl. The adsorption preference of herb residues pre-treated with NaOH or HCl was $Pb^{2+}>Cu^{2+}$ or $Cd^{2+}>Cr^{6+}$ in the order. Conclusively, the herb residue can be used as an alternative adsorbent for the removal of heavy metals depending on pr-treatment methods.

• 한국식품저장유통학회지
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• 제6권1호
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• pp.1-6
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• 1999

Fresh gingers, harvested in Seosan, Choongcheongnam-do, were pre-treated by a washing-pasteurizing-drying process, a curing process, and non-treated, respectively. Then they were stored in a lab-scale storage room(12$^{\circ}C$, >92%RH) to investigate the effect of pre-treatment methods on the quality changes during long-term storage. Weight loss of ginger during storage showed ranges in 0.7∼4.3%, and the weight of gingers pre-treated by washing-drying process showed a tendency to change less than those treated by curing. After storage of 130 days, spoilage rates were about 20% in non-treated, 11% in curing treated, and 12% in washing-drying treated ginger,, showing the effect of pre-treatment. The final rate of sprouting was 13∼15% regardless of treatment methods. The firmness of gingers showed a tendency to decrease in stored ginger for the longer period; however, the values were ranged from 1,200 to 1,400 g/$\textrm{cm}^2$, that is hard enough to show a marketable quality. The contents of reducing sugar showed a tendency to increase with the lapse of storage time.

• Journal of the Korean Wood Science and Technology
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• 제25권4호
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• pp.92-98
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• 1997

To make good use of chitosan forming complex with heavy metals in wood preservative treatment, woods impregnated with chitosan and copper sulfate were prepared. Amounts of leached copper, decay resistance, anti-mold efficacy, iron corrosion rates, moisture regain rates and degradation pattern in chitosan pre-treated and untreated wood were compared. After leaching test, amounts of leached copper from chitosan pre-treated wood had a much smaller than chitosan untreated wood, and good decay resistance was retained even after leaching test. From these results, it was proved that chitosan-copper complex formed in wood played and important role for decay durability. In chitosan pre-treated wood, damage values by test molds became remarkably smaller, but the growth of test molds was not perfectly inhibited. Distinct differences in iron corrosion rates between chitosan pre-treated and untreated woods was not recognized but chitosan pre-treated wood showed the lower moisture regain rates than chitosan untreated wood because of water insoluble chitosan membrane formed in wood. After leaching test, the tracheid walls in the wood treated with 2.0% copper sulfate only were eroded by the fungal attacks, but those in the wood pre-treated with chitosan remained almost intact.

• 한국염색가공학회지
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• 제31권2호
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• pp.88-97
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• 2019

In this study, when printed on a nylon material, the color strength and fastness are lower than that of a polyester material, and the nylon material shrinks due to heat and pressure, resulting in poor design and poor compatibility. To overcome this problem, we investigated the possibility of transfer DTP by adding pre-treatment process to nylon transfer DTP process. For the basic study of pre-treatment preparation, we used pure nylon material which is not compounded and dispersion ink and transfer paper applied to existing PET transfer DTP. Pre-treatment preparations were classified into three types of acryl-base polymer and pre-treated with nylon and then applied to transfer DTP to confirm their color strength and fastness. The color strength of the pre-treated nylon material increased and poly-methyl-acrylate amulsion pre-treatment showed the best color at $210^{\circ}C$, 1.5m/min and 0.3MPa. The nylon material pre-treated with washing, friction, and light fastness was judged to be more excellent and stable.

• 한국염색가공학회지
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• 제18권1호
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• pp.1-9
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• 2006

Treatment of PET fabrics with alkali, chitosan and Al-mordanting has been carried out and the role of the chitosan coating in the dyeing process was clarified. The pre-treatment was effectively evaluated differences in dyeing behavior between its treated and untreated PET fabrics using wood of Caesalpinia sappan. The pre-treated on PET fabrics has been examined by SEM and evidence for the presence of chitosan sought using a air permeability test. Similar colour fastness by computer color matching(CCM) obtained on both untreated and pre-treated PET fabrics. The pre-treated PET was found to be of a deeper hue to that of its dyed untreated PET and, despite of its better colour depth, the wash fastness of the pre-treated dyeing was comparable to that of its dyed untreated PR. The application of chitosan or mordanting reveled that pre-treatment imparted to the PET additional functional groups that were available for coordination with the Brazilin.

• 한국자동차공학회논문집
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• 제24권5호
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• pp.588-595
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• 2016

This paper is a study on head bolts that are used in A/C compressors to reduce production cost and solve leak problems on the head bolt seat area that causes massive intermittent malfunctioning during production. In this study, the pre-heat treated steel, which was used as a material in the head bolt, eliminated the heat treatment process after forging. The pre-heat treated steel head bolts, which have 10 % lower tensile strength than the conventional SCM 435 head bolts, were selected after considering the results of creeping rupture properties, axial force, and stress concentration per tensile strength variation. Then, the performance test and the durability test with the A/C compressor that was assembled with the pre-heat treated steel head bolts were performed and verified. Based on the results, the pre-heat treated steel head bolts developed in this study saved 7.3 % in production cost by eliminating the heat treatment process and the logistics process. Furthermore, the leak problem on the head bolt seat area in the A/C compressor was addressed significantly on the mass production assembly line.