• Journal of the Korean Chemical Society
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• v.56 no.5
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• pp.583-590
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• 2012

The HF (Hollow fiber) extraction method was optimized to analysis seven species of pesticides in aqueous sample and analyzing samples by GC/MS. Hollow fiber extraction showed good efficiency when it was conducted under these conditions: organic solvent was toluene and agitation speed was 1200 rpm. The 15% concentration of NaCl was optimized when it was experimented between 5% and 25%. The equilibrium time was determined at 15 minutes. The pH 5 showed the best effect on the extraction efficiency. The linearities of calibration curves of seven species were good with correlation of regression ($r^2$) over 0.995 when they were experimented over a concentration range of $5{\mu}g/L$ to $50{\mu}g/L$. The analytical data exhibited the detection of limits (LODs) range of $0.37{\mu}g/L$ to $1.23{\mu}g/L$ and the limit of quantification (LOQs) range of $1.19{\mu}g/L$ to $3.91{\mu}g/L$. The optimized HF-LPME extraction method provides a simple and effective preparation and requires small amount of organic solvents and samples compared to conventional pre-treatment methods.

• Journal of the Korea Concrete Institute
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• v.25 no.5
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• pp.497-508
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• 2013

This paper introduces a numerical model which can evaluate the fire-resistant capacity of reinforced concrete members. On the basis of the transient heat transfer considering the heat conduction, convection and radiation, time-dependent temperature distribution across a section is determined. A layered fiber section method is adopted to consider non-linear material properties depending on the temperature and varying with the position of a fiber. Furthermore, effects of non-mechanical strains of each fiber like thermal expansion, transient strain and creep strain are reflected on the non-linear structural analysis to take into account the extreme temperature variation induced by the fire. Analysis results by the numerical model are compared with experimental data from the standard fire tests to validate an exactness of the introduced numerical model. Also, time-dependent changes in the resisting capacities of reinforced concrete members exposed to fire are investigated through the analyses and, the resisting capacities evaluated are compared with those determined by the design code.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.3
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• pp.386-393
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• 2011

Three trials were conducted to determine the available energy of different wheat screening varieties collected from different locations of Khorasan in Iran. In experiment 1, chemical composition and the nitrogen corrected true metabolisable energy (TMEn) were evaluated. A precision-fed rooster assay was used, in which, each wheat screening sample was tube fed to adult roosters, and the excreta were collected for 48-h. In Exp. 2 and 3, five and two wheat screening verities-based diets with or without xylanase and phytase were fed to 16-day old battery reared chicks respectively, and total feed consumption and excreta were measured during next three days. The variable nature of wheat screening varieties led to significant differences in mean TMEn values (p<0.01). The TMEn values of samples determined with adult roosters varied by ${\pm}5.03%$ of the mean value ($3,097.65{\pm}49.32\;kcal/kg$) and ranged from 2,734.90 to 3,245.12 kcal/kg. There was a significant correlation (p<0.05) between crude fiber (CF), neutral detergent fiber (NDF), and acid detergent fiber (ADF) with TMEn, and the greatest correlation coefficient was observed between NDF and TMEn (r = -0.947; p<0.001). The optimal equation in terms of $R^2$ from using a single chemical analysis was obtained with NDF: TMEn = 4,152.09-27.80 NDF ($R^2$ = 0.90, p<0.0001), and the TME prediction equation was improved by the addition of the crude protein (CP) and ASH content to sequential analysis: TMEn = 3,656.97-28.65 NDF+32.54 CP+38.70 ASH ($R^2$ = 0.98, p<0.0001). The average AMEn values of 5 and 2 wheat screening varieties determined with young broiler chickens were $2,968.41{\pm}25.70\;kcal/kg$ and $2,976.38{\pm}8.34\;kcal/kg$ in Exp. 2 and Exp. 3, respectively. Addition of xylanase and phytase to wheat screenings resulted in significant (p<0.01) improvement in AMEn by 4.21 and 2.92%, respectively.

• Membrane Journal
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• v.24 no.3
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• pp.223-230
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• 2014

A numerical analysis was performed for concentration of methane from the biogas using a polysulfone hollow fiber membrane permeator. Governing equations were derived for the countercurrent flow and numerically solved by using the Compaq Visual Fortran 6.6 software. When the methane mole fraction of feed was 0.5, the mole fraction of retentate increased from 0.5 to 0.8; the normalized retentate flow rate to the feed flow rate decreased from 1.0 to 0.57 at the given typical operating condition as the feed gas flowed from the inlet to the outlet of the membrane. As the methane mole fraction of feed was changed to 0.9, the methane mole fraction of retentate became 0.93 and the normalized retentate flow rate was changed to 0.91. When the pressure ratio of the permeate to the feed was varied from 0.33 to 0.17, there was a little difference in the methane mole fraction of retentate for the low stage cut of 0.1, whereas there was an significant increment for the high stage cut of 0.3. The retentate methane mole fraction remained relatively high despite the change of a stage cut as the area of the membrane increased from $1.14m^2$ to $2.57m^2$.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.3
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• pp.919-930
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• 2014

In this study, the load capacities and behaviors of a shotcrete member with steel supports, as composite member, are investigated numerically by using a fiber section element. The cross section of a shotcrete lining with steel support is divided into a bundle of fibers, which are allocated nonlinear stress-strain relations and used for determining internal forces. To verify the used approach of the finite element method for shotcrete with steel supports, the load-displacement relations of shotcrete lining obtained by numerical analysis are compared with existing experimental results and are analyzed with the stress distribution of the shotcrete and steel support obtained numerically. As a result, it is shown that the proposed approach can predict the load capacities of each material and the overall nonlinear behavior of shotcrete lining with steel supports. The change of location of the neutral axis and the flexural resistance ratio of each material are also derived from the stress distribution of the cross section of the shotcrete lining with steel supports. From the results, it is concluded that the flexural resistance performance of steel support should be considered in shotcrete lining design.

• The Korean Journal of Food And Nutrition
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• v.29 no.5
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• pp.663-669
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• 2016

This study was conducted to analyze the nutrient compositions of stem and fruit of Opuntia ficus-indica var. saboten (OF) and Opuntia humifusa (OH). The results of the two-way analysis of variance test indicated that the parts, varieties and parts*varieties had influence on nutrient content except crude protein, soluble dietary fiber, Fe, Se, I, vitamin E, niacin and vitamin C. Moisture and crude ash content was higher in stem than in fruit, while crude lipid and insoluble dietary content was higher in fruit than in stem. Mineral content revealed that K (1,313.67 mg% in OF, 1,351.38 mg% in OH) was the highest in fruit and Ca (5,146.29 mg% in OF, 1,388.19 mg% in OH) was the highest in stem. Vitamin C was the most abundant vitamin in the fruit of OF (199.98 mg%) and OH (187.12 mg%). Polyunsaturated fatty acid was the highest among fatty acids (66.9~70.1%), with higher content in the stem (753.89 mg%) than fruit (578.01 mg%) in OF, while higher in the fruit (1,093.63 mg%) than stem (475.07 mg%) in OH. Moisture, crude protein, Mg, Se and riboflavin was higher in OF than OH; whereas, crude lipid, insoluble dietary fiber, total dietary fiber and monounsaturated fatty acid were higher in OH than OF. These results indicated that OF and OH could be a good food source for Ca, K and Vitamin C. Also, different nutrient content by parts and varieties, can be helpful in choice of parts or varieties for consumer purposes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.339-346
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• 2008

The contents of starch, moisture, crude protein, crude fat, crude fiber, and ash of different varieties of various crops such as brown rice, barley, corn, sweet potato were analyzed. The average starch contents of brown rice, barley, corn, and sweet potato were $70.1{\pm}0.4\;{\sim}\;72.2{\pm}2.1$, $68.7{\pm}0.2\;{\sim}\;71.4{\pm}1.2$, $67.6{\pm}0.8\;{\sim}\;69.4{\pm}1.8$, and $21.7{\pm}0.9\;{\sim}\;28.3{\pm}0.5%$, respectively. The ground powder of each starchy substrate was suspended in distilled water, and then liquefied, saccharified, and fermented by dried active yeast at 32 for 4 days. By statistical analysis, the effectiveness of the contents of the different components such as starch, moisture, crude protein, crude fat, crude fiber, and ash of the crops on the ethanol production were examined. The results showed that the starch content positively affected the ethanol production in all the tested cereals and sweet potato. In brown rice, ash content affected negatively the ethanol production. In barley, protein content affected negatively the ethanol production, while fiber content affected positively the ethanol production. The sweet potato containing higher content of moisture produced less amount of ethanol.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.517-523
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• 2016

Purpose: This study examined the food composition of four raw and boiled domestic potato cultivars: Superior, Dejima, Bora Valley and Rose. Methods: Proximate composition (moisture, protein, ash, dietary fiber and fat), minerals (calcium, phosphorus, iron, potassium, sodium and magnesium) and vitamins (thiamine, riboflavin and niacin) were analyzed in the study. Results: In this study, it was observed that the moisture contents of raw and boiled Bora Valley potato were 83.74 g/100 g and 81.57 g/100 g, respectively, which was highest among the studied cultivars. The protein content of the raw and boiled Rose potato (12.23 g/100 g and 11.02 g/100 g) was higher than that of the other cultivars. Protein contents of boiled Bora Valley and Rose potatoes were significantly lower than those of their respective raw samples. The potassium, phosphorus and sodium contents of Bora Valley potato were 2,397.69 mg/100 g, 389.13 mg/100 g and 14.12 mg/100 g, respectively. In case of raw potato, the calcium, iron and magnesium contents of Dejima potato were 51.52 mg/100 g, 3.21 mg/100 g and 137.62 mg/100 g, respectively, which were the highest values among the tested potato cultivars. Total dietary fiber content of Dejima potato was 14.78 g/100 g, which was the highest level. The dietary fiber contents of four cultivars of potatoes were lower after boiling. Thiamine content was highest in the Bora Valley potato (0.43 mg/100 g). Riboflavin contents of the Rose potato was 0.35 mg/100 g, which was higher than that of the others. Conclusion: Overall, four cultivars of raw and boiled potatoes had enhanced food composition. Therefore, these potato cultivars are expected to be highly valuable food items for the development and application of functional foods.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.869-875
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• 1997

The chemical components of Korean pollens and pollen extracts were analysed to provide fundamental data for pollen processing and products development. The contents of crude protein, crude lipid, crude ash, crude fiber and carbohydrate of pollens were $14.0{\sim}22.3%,\;3.0{\sim}8.8%,\;2.2{\sim}3.3%,\;0{\sim}37.5%,\;and\;31.9{\sim}64.4%$ respectively, showing the specially high crude fiber content (37.5%) in Pine pollen. Almost all the carbohydrate, lipid, protein and ash components except fiber were extracted by water and n-hexane. Free sugars identified in water extracts $(10\;^{\circ}Bx)$ of pollens were fructose and glucose as major component and maltose as minor component. The proportions of three free sugars to total soluble solid content of Mixed, Acorn, and Pine water extracts were 73.6%, 85.4% and 47.7% respectively. Potassium and phosphorus content in pollens and pollen water extracts were high, but Ca, Na, Mg, Fe and Zn were not major mineral components. The essential amino acids such as leucine, phenylalanine, methionine, lysine, valine, isoleucine and threonine were contained richly in pollens and those were almost completely extracted by water. Vitamin $B_1$ and C were not detected, but only small amount of vitamin $B_2$ was detected in the pollens and pollen extracts tested. The essential fatty acids such as linoleic acid and linolenic acid were contained richly in pollens. The proportion of unsaturated fatty acids to total fatty acid content in Mixed, Acorn and Darae pollen except Pine was higher than 50%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1405-1411
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• 2006

The presence and content of residual hexane in the olive oils were studied. Total 41 olive oils of imported and domestic brands, which were labeled as extra virgin and refined (mixed), were collected from the market. For analysis, electronic nose and headspace SPME-GC/MS were used. Electronic nose equipped with 12 metal oxide sensors was used for the discrimination of odor pattern of olive oils against the different concentrations of hexane. From the results, it is assumed that the contents of residual hexane in the collected olive oils were below 5 ppm. For Qualitative and quantitative analysis of hexane, polydimethylsiloxane (PDMS) fiber was employed for SPME-GC/MS. In the results, the peak of residual hexane was detected in 8 samples from 41 olive oils. But the detected level was no more than 1 ppm that is under the regulation limit (5 ppm) by Korea Food Additive Code.