• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.25 no.1
• /
• pp.58-61
• /
• 2012

In our report a relatively simple process for fast nano-texturing of p-type(100) CZ- silicon surface using silver catalyzed wet chemical etching in aqueous hydrofluoric acid (HF) and hydrogen peroxide solution($H_2O_2$) at room temperature. The wafers were saw-damaged by NaOH(6 wt%) at $60^{\circ}C$ for 150s. To obtain a nano-structured black surface, a thin layer of silver with thickness of 1 - 10 nm was deposited on the surfaces by evaporation system. After this process the samples were etched in HF : $H_2O_2$ : $H_2O$ = 1:5:10 at room temperature for 80s - 220s. Due to the local catalytic of the Ag clusters, this treatment results in the nano-scale texturing on the surface. This resulted in average reflectance values less than 9% after the silver on the surface of the wafers were removed.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.11
• /
• pp.3444-3450
• /
• 2013

Three phase hollow fiber-liquid phase microextraction (HF-LPME), which is faster, simpler and uses a more environmentally friendly sample-preparation technique, was developed for the analysis of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) in human urine. For the effective simultaneous extraction/concentration of NSAIDs by three phase HF-LPME, parameters (such as extraction organic solvent, pH of donor/acceptor phase, stirring speed, salting-out effect, sample temperature, and extraction time) which influence the extraction efficiency were optimized. NSAIDs were extracted and concentrated from 4 mL of aqueous solution at pH 3 (donor phase) into dihexyl ether immobilized in the wall pores of a porous hollow fiber, and then extracted into the acceptor phase at pH 13 located in the lumen of the hollow fiber. After the extraction, 5 ${\mu}L$ of the acceptor phase was directly injected into the HPLC/UV system. Simultaneous chromatographic separation of seven NSAIDs was achieved on an Eclipse XDB-C18 (4.6 mm i.d. ${\times}$ 150 mm length, 5 ${\mu}m$ particle size) column using isocratic elution with 0.1% formic acid and methanol (30:70) at a HPLC-UV/Vis system. Under optimized conditions (extraction solvent, dihexyl ether; $pH_{donor}$, 3; $pH_{acceptor}$, 13; stirring speed, 1500 rpm; NaCl salt, 10%; sample temperature, $60^{\circ}C$; and extraction time, 45 min), enrichment factors (EF) were between 59 and 260. The limit of detection (LOD) and limit of quantitation (LOQ) in the spiked urine matrix were in the concentration range of 5-15 ng/mL and 15-45 ng/mL, respectively. The relative recovery and precision obtained were between 58 and 136% and below 15.7% RSD, respectively. The calibration curve was linear within the range of 0.015-0.96 ng/mL with the square of the correlation coefficient being more than 0.997. The established method can be used to analyse of NSAIDs of low concentration (ng/mL) in urine.

• Journal of the Korean Ceramic Society
• /
• v.20 no.3
• /
• pp.227-235
• /
• 1983

The dielectric and piezoelectic properties in which $(Zr_{0.52} Ti_{0.48})^{+4}$ ions of $Pb(Zr_{0.52} Ti_{0.48})O_3$ are partially substituted for $W^{+6}$ ions were studied. $ZrTiO_4$ was made by coprecipitation. The specimens of disc shape were sintered respectively at 1180$^{\circ}$to 130$0^{\circ}C$ at an intervals of 2$0^{\circ}C$ for 1 hour. The optimum sintering temperature were found to be between 126$0^{\circ}C$ and 128$0^{\circ}C$. PZT solid solutions sintered had the tetragonal structure with c/a=1.025$\pm$0.005 and theoretical densities incre-ased from 8.02 to 8.17g/cm3 with increasing the amount of the partial substitution of $(Zr_{0.52} Ti_{0.48})^{+4}$ ion for $W^{+6}$ ion The grain size and curie temperature decreased with increasing the amount of $WO_3$ while the dielectric constant increased. When $(Zr_{0.52} Ti_{0.48})^{+4}$ ion was substituted for 1 mole% of $W{+6 ]$ion the planar coupling coefficient$(K_P)$ was as high as 0.58 But as the amount of $WO_3$ increased the mechanical quality factor(Qm) decreased considerably.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.58 no.2
• /
• pp.83-90
• /
• 2016

This study was performed to evaluate the effective analysis of flexural performance for polypropylene fiber (PF) reinforced EVA concrete that can be used in marine bridge, tunnel and agricultural structures under flexural load. The control design was applied in ready mixed concrete using 10 % fly ash of total binder weight used in batch plant. On the basis of the control mix design, there was designed mix types that contained PF ranged from 0 % to 0.5 % by volume ratio into two mix types of using 0 % and 5.0 % EVA contents of total binder weight. Before evaluating the flexural performance, we tested compressive strength and flexural strength to evaluate whether polypropylene fiber reinforced concrete could be used or not in site. The method of flexural performance evaluation was applied by ASTM C 1609. These results showed the maximum compressive strength and flexural strength was measured at each E5P1 and E5P2. Concrete reinforced with PF exhibited deflection-softening behavior. In the concrete reinforced with 0.4 % PF contents and containing 5.0 % EVA, the flexural performance was the best.

• Food Science of Animal Resources
• /
• v.33 no.1
• /
• pp.58-66
• /
• 2013

In this study, the effect of packaging methods [aerobic packaging (AP), vacuum packaging (VP) and modified atmosphere packaging (MAP: 75% $N_2$, 25% $CO_2$)] on colour, lipid quality and microbial growth of beef patties enhanced with flaxseed flour was investigated during storage at $2{\pm}1^{\circ}C$ for 10 d. L and a values of beef patties packaged in MAP and VP were higher (p<0.05) than that of the samples packaged in AP. Packaging in MAP and VP retarded the lipid oxidation (TBA value) and inhibited the bacterial growth of beef patties enhanced with flaxseed flour. Furthermore, TBA values in beef patties were correlated with a values (r = -0.340; p<0.05). Packaging in MAP was more effective than packaging in VP for inhibiting microbial growth. The samples packaged in VP lost their shape due to the compression by external atmosphere. Packaging treatment had no significant effect on saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) levels in beef patties. The a and b, TBA and MUFA values changed during storage time. TBA values for beef patties increased during storage time, but did not reach to the limit value (1 mg/kg) until the end of the storage time. The results suggest that the shelf life of beef patties enhanced with flaxseed flour can be extended by packaging in MAP.

• Korean Journal of Microbiology
• /
• v.9 no.3
• /
• pp.95-102
• /
• 1971

The growth characteristics of Candida tropicalis KIST 351 on gas oil substrate under different culture conditions were investigated and the preliminary animal feeding experiments using this yeast as a partial substitute of fish meal was also conducted. The yeast assimilates effectively n-paraffins in gas oil ranging from $C_{16}$ to $C_{16}$ with its maximum cell growth at $33^{\circ}C$ and pH 5.5 with aeration of 3 vvn and agitation of 900 rpm. The optimal concentrations of nitrogen sources, $HK_2PO_4$ and $Na_2HPO$ were 4, 2 and 0.5g/1, respectively. Ferrous sulfate, manganese sulfate and zinc sulfate showed positive effect to cell growth with the optimal range of 5-10 ppm. In the feeding experiment with 3 and 5% incorporation of the gas oil grown yeast, neither adverse effects on growth of chicks nor toxic effect were observed. Protein content of the dried cell was 58.8% and its amino acid composition compared well with other single-cell protein products and FAO reference protein.

• Korean Journal of Food Science and Technology
• /
• v.38 no.3
• /
• pp.342-347
• /
• 2006

Korean pear juice heat-treated at various temperatures (110, 120, 130, 140, and $150^{\circ}C$) and times (1, 2, 3, 4, and 5 hr) was analyzed to determine total polyphenol, total flavonoid, free sugar, and 5-HMF contents, and DPPH free radical-scavenging activity. Total polyphenol, total flavonoid, and 5-HMF contents, and antioxidant activities increased, whereas fructose content decreased with increasing heat treatment temperature and time ($p\;{\pm}\;0.007\;mg/g$ with treatment at $150^{\circ}C$ for 1 hr (unheated pear juice: $0.233\;{\pm}\;0.024\;mg/g$). Highest total flavonoid content was $561.49\;{\pm}\;16.93\;{\mu}g/g$ with treatment at $150^{\circ}C$ for 4 hr (unheated pear juice: $1.50\;{\pm}\;0.20\;{\mu}g/g$). $IC_{50}$ value was highest, $1.93\;{\pm}\;0.01\;mg/g$, at $150^{\circ}C$ for 2 hr, whereas that of unheated pear juice was $64.58\;{\pm}\;0.99\;mg/g$. Glucose content was not affected by treatment conditions, whereas fructose content decreased with treatment at $140^{\circ}C$ for 3 hr. Highest 5-HMF content was $5,594.93\;{\pm}\;6.43\;ppm$ at $150^{\circ}C$ for 5 hr (unheated pear juice: $2.04\;{\pm}\;0.21\;ppm$). Correlation coefficients were observed among total phenolic, total flavonoid, and antioxidant activities, and between fructose and 5-HMF at significance level (p<0.001).

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.3
• /
• pp.957-962
• /
• 2012

Objective: Rapidly increasing colorectal cancer (CRC) incidence in Malaysia and the introduction of cutting edge new treatments, which prolong survival, mean that treatment outcome measures meed to be evaluated, including consideration of patient's quality of life (QoL) assessment. There are limited data on QoL in CRC patients, especially in Malaysia. Therefore, this study was performed focusing on cancer stages and age groups. Methods: The cross sectional study was conducted from June to September 2011 at three public tertiary hospitals with the EORTC QLQ C-30 questionnaire in addition to face to face interview and review of medical records of 100 respondents. Results: The mean age was 57.3 (SD 11.9) years with 56.0% are males and 44.0% females, 62% of Malay ethnicity, 30% Chinese, 7% Indian and 1% Sikh. Majority were educated up to secondary level (42%) and 90% respondents had CRC stages III and IV. Mean global health status (GHS) score was 79.1 (SD 21.4). Mean scores for functional status (physical, emotional, role, cognitive, social) rangeds between 79.5 (SD 26.6) to 92.2 (SD 13.7). Mean symptom scores (fatigue, pain, nausea/vomiting, constipation, diarrhea, insomnia, dyspnoea, loss of appetite) ranged between 4.00 (SD 8.58) to 20.7 (SD 30.6). Respondents role function significantly deteriorates with increasing stage of the disease (p=0.044). Females had worse symptoms of pain (p=0.022), fatigue (p=0.031) and dyspnoea (p=0.031). Mean insomnia (p=0.006) and diarrhea (p=0.024) demonstrated significant differences between age groups. Conclusion: QOL in CRC patients in this study was comparable to that in other studies done in developed countries. Pain, fatigue and dyspnoea are worse among female CRC patients. Given that functions deteriorates with advanced stage of the disease at diagnosis, a systematic screening programme to detect cases as early as possible is essential nationwide.

• Korean Journal of Environmental Agriculture
• /
• v.15 no.2
• /
• pp.179-187
• /
• 1996

This study was conducted to investigate the possibility of composting of household garbage. The composter with the double layer walls was operated for 60 days in each season. The following results were obtained at the end of the experiment, if the time was not specified. 1) The maximum temperature was $31^{\circ}C$ in spring, $36^{\circ}C$ in summer and $50^{\circ}C$ in winter. 2) The mass was reduced to an average of 58.5%. 3) pH values of the compost were 8.21 in spring, 8.29 in summer and 7.94 in winter. 4) The ash contents were 55.8% in spring, 57% in summer and 73.8% in winter. 5) The nitrogen contents were in the range of $0.2{\sim}5.8%$. Its values were the highest in winter and the lowest in summer. 6) Inorganic contents of the compost were in the range of : $P_2O_5$ ; $1.5{\sim}4.41%$, $K_2O$ ; $0.02{\sim}1.31%$, CaO $0.13{\sim}1.68%$ and MgO $0.05{\sim}1.22%$. 7) Heavy metal contents of the compost were in the range of : Zn ; $13{\sim}89mg/kg$, Cu ; $4{\sim}62mg/kg$, Cd ; $1{\sim}21mg/kg$, Pb ; $N.D.{\sim}97mg/kg$, Cr ; $N.D.{\sim}37$ and Hg ; $N.D.{\sim}1.38mg/kg$.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.3
• /
• pp.1089-1092
• /
• 2016

Breast cancer is the most commonly occurring and leading cause of cancer deaths among women globally. Hereditary cases account 5-10% of all the cases and CHEK2 is considered as a moderate penetrance breast cancer risk gene. CHEK2 plays a crucial role in response to DNA damage to promote cell cycle arrest and repair DNA damage or induce apoptosis. Our objective in the current study was to analyze mutations in the CHEK2 gene related to breast cancer in Balochistan. A total of 271 individuals including breast cancer patients and normal subjects were enrolled. All 14 exons of CHEK2 were amplified and sequenced. The majority of the patients (>95%) had invasive ductal carcinomas (IDCs), 52.1% were diagnosed with tumor grade III and 56.1% and 27.5% were diagnosed with advance stages III and IV. Two novel nonsense variants i.e. c.58C>T (P.Q20X) and c.256G>T (p.E85X) at exon 1 and 2 in two breast cancer patients were identified in the current study. Both the variants identified were novel and have not been reported elsewhere.