• Computers and Concrete
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• v.14 no.5
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• pp.599-612
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• 2014

This paper presents the effects of the construction stages using time dependent material properties on the structural behaviour of concrete arch dams. For this purpose, a double curvature Type-5 arch dam suggested in "Arch Dams" symposium in England in 1968 is selected as a numerical example. Finite element models of Type-5 arch dam are modelled using SAP2000 program. Geometric nonlinearity is taken into consideration in the construction stage analysis using P-Delta plus large displacement criterion. In addition, the time dependent material strength variations and geometric variations are included in the analysis. Elasticity modulus, creep and shrinkage are computed for different stages of the construction process. In the construction stage analyses, a total of 64 construction stages are included. Each stage has generally $6000m^3$ concrete volume. Total duration is taken into account as 1280 days. Maximum total step and maximum iteration for each step are selected as 200 and 50, respectively. The structural behaviour of the arch dam at different construction stages has been examined. Two different finite element analyses cases are performed. In the first case, construction stages using time dependent material properties are considered. In the second case, only linear static analysis (not considered construction stages) is taken into account. Variation of the displacements and stresses are obtained from the both analyses. It is highlighted that construction stage analysis using time dependent material strength variations and geometric variations has an important effect on the structural behaviour of arch dams. The maximum longitudinal, transverse and vertical displacements obtained from construction stages and static analyses are 1.35 mm and 0 mm; -8.44 and 6.68 mm; -4.00 and -9.90 mm, respectively. In addition, vertical displacements increase from the base to crest of the dam for both analyses. The maximum S11, S22 and S33 stresses are obtained as 1.60MPa and 2.84MPa; 1.39MPa and 2.43MPa; 0.60MPa and 0.50MPa, respectively. The differences between maximum longitudinal, transverse, and vertical stresses obtained from construction stage and static analyses are 78%, 75%, and %17, respectively. On the other hand, there is averagely 12% difference between minimum stresses for all three directions.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.546-551
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• 1993

Rice flour obtained by four different milling methods, Pin mill. Colloid mill, Micro mill, and Jet mill, were used to investigate physico-chemical properties and product. Crude fat, ash, and protein contents of rice flours between different milling methods were similar. Blue value, amylose content, and damaged starch which related to properties of rice flour were reduced in the order that of Jet mill, Micro mill, Colloid mill, and Pin mill. Water absorption index, water solubility index, and water retention capacity increased as damaged starch increased. Hardness of gel(15%) is the highest value for Pin mill. The finer granules (Jet mill) had lower gelatinization onset(To) and peak(Tp) than any other rice flours. Those result are simillar with amylogram properties. Enthalpy of gelatinization increased as damaged starch increased. Jet mill had the highest score (p<0.05) of overall test in sensory evaluation and good paste properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.569-576
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• 2016

This study researched the effects of cooking methods on phytochemical-enriched thin rice porridge (RP) of three colors (red, yellow, and green). Each of the RPs was prepared by three cooking methods and retorted through two-steps (step 1, at $80^{\circ}C$ for 15 min; step 2, at $82^{\circ}C$ for 25 min) for pasteurization. Cooking method (CM) 1 involved heating a mixture of all ingredients while CM 2 involved addition of apple/beet (AB, red), sweet-pumpkin/cabbage (PC, yellow) or vitamin/pear (green) while heating rice flour and glutinous rice flour. CM 3 involved mixing pre-cooked fruits and vegetables with cooked thin RP. The viscosity of RP prepared by CM 1 was lower than those of other RPs (P<0.05). The result of colorimetric a value show that red and green color of AB and VP prepared by CM 2 and CM 3 were most vivid. Contents of phytochemicals and antioxidants were higher when RP was prepared by CM 2 and CM 3 compared to CM 1. ${\Delta}E$ values of PC showed no significant difference before and after pasteurization, whereas AB and VP were significantly different (P<0.05). Antioxidant activity after retorting was not significantly different from those of un-retorted RPs. The results of color, phytochemical content, and antioxidant activity show that CM 2 or CM 3 were considerably better than CM 1, whereas cooking method had no effect after two-step retorting. Therefore, uncomplicated cooking method such as CM 1 or CM 2 are suited for commercial production of RPs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.4
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• pp.557-566
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• 2005

In preparation of steamed foam-cakes, effects of whipping time, amount of wheat flour, and amounts of emulsifier on physical properties of the steamed foam cakes were investigated using RSM (response surface methodology). The three independent variables selected for the RSM experiment were whipping time $(X_1)$, amount of wheat flour $(X_2)$, and amounts of wheat flour $(X_2)$, and concentration of emulsifier $(X_3)$ were set for single-stage mixing, respectively. A rotatable central composite design was used for treatment arrangement. The responses from the product for loaf volume, color values and textural properties were analysed. In the analysis of variance for the foam cakes prepared by single-stage method, significant interactions were observed between independent variables (experimental factors) and physical property like loaf volume (p<0.05); textural properties like hardness, gumminess, and chewiness (p<0.05). Among independent variables, concentration of emulsifier had the most effects on physical properties while whipping time. The ordinary points in surface response showed maximal points with physical property like colorimetric b value while other properties revealed saddle points. The 3-dimensional response surface graphs of the predicted regression models displayed decreasing loaf volumes with increasing whipping times and emulsifier concentrations beyond optimum levels. The optimum conditions for best loaf volume and textural property (hardness, gummimess and chewiness) of the products selected by extracting intersectional areas of the contour maps that commonly overlapped all characteristics were; $11\~13$ min whipping time, $470\~486\;g$ amount of wheat flour, and $19\~20\;g$ emulsifier concentration, in case of single-stage method. The median values extracted from the RSM experimental results for optimum manufacturing conditions for single-stage method, i.e., 12 min whipping time, 478 g amount of wheat flour, and 20 g emulsifier concentration were empirically proven to fit the predicted levels of physical properties from the final foam cakes.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1048-1056
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• 2002

Quality of fresh ginger deteriorates rapidly during low temperature storage, and its storage life is short due to sprouting and microbial spoilage. The objectives of this research were to develop, using additives, a minced ginger product, which could maintain acceptable quality for over 30 days, and to investigate its quality changes during the cold storage. Storage stability of minced ginger product was investigated from the standpoint of the inhibition of brown discoloration, gas formation and liquid-solid separation. Fresh ginger was peeled and ground to produce minced ginger (control). Sodium bisulfite, L-cysteine, NaCl, sodium benzoate, modified starch, and/or xanthan gum were added to the control to minimize quality loss during storage, and to develop an optimum formula (A) of minced ginger. Samples were packed in Nylon/PE films, stored at $5^{\circ}C$, sampled at a 30-day interval, and subjected to quality evaluations. Changes in pH, surface color, gas formation, liquid-solid separation, contents of free amino acids, free sugars, organic acids, and fatty acids were determined. Gas formation was effectively inhibited in samples with sodium benzoate and/or NaCl. Samples with xanthan gum did not result in liquid-solid separation. L-Cysteine and sodium bisulfite were effective in controlling discoloration. pH decreased during storage in all samples, except sample A. Organic acid contents of all samples increased during storage, with lactic acid content showing the highest increase. Free amino acid content decreased with increasing storage time. Free sugar content of all samples decreased during storage. Sensory results showed sample A maintained acceptable quality until 90 days of storage. These results suggest that quality of minced ginger could be successfully maintained with the additions of selected additives for up to 90 days.

• Korean journal of food and cookery science
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• v.21 no.3 s.87
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• pp.301-310
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• 2005

The effects of defatted soy flour on the physicochemical characteristics of dough and bread making properties were studied. Defatted soy flour is added to wheat flour for bread-making in order to maximize the use of isoflavones in the soybean. Different particle sizes of both defatted soy flour and wheat flour were prepared by grinding and sievingwith meshes. In the mixograph test, the addition of defatted soy flour to wheat flour increased the requirement for water and decreased the dough development time. Water absorption rates were also investigated to determine the optimum quantity of water for good dough. As the level of defatted soy flour mixed with wheat flour increased, the sedimentation and P.K. values decreased. In comparison with control, the bread made with defatted soy flour especially had a lower specific loaf volume. Specific loaf volume of wheat flour-defatted soy flour bread prepared (Ed- this is an incomplete sentence, it's only a subject clause, and I don't how what you intend to state). In terms of the staling rate and hardness of the wheat flour-defatted soy flour bread, the increased defatted soy flour had a faster staling rate during storage at 5? than at 25? for 5days. From the result of sensory evaluation, wheat flour-defatted soy flour breads containing up to $4\%$ defatted soy flour were rated as being of high quality.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.1
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• pp.20-27
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• 1983

A series of laboratory experiment was conducted to find out the chemical composition, characterization of humic substances by physical and chemical methods and reaction of Na-pyrophosphate, $Ca(OH)_2$ and rice straw with albumin on the degradation of soil organic matter in the volcanic ask soils of the Jeju Island. Results obtained were summarized as follows: 1. The contents of organic matter, available silicon, active iron and aluminum concentration in volcanic ash the soils were remarkably higher but available phosphorous was comparatively lower than the mineral soils. In volcanic ash soil, the contents of potassium, calcium and magnessium were higher in upland soil than that of forest soil. The ratios of active $Al^{{+}{+}{+}}/Fe^{{+}{+}}$, C/P and $K/Ca^+$ Mg were apparently high in volcanic ash soils while that of $SiO_2$/O.M. was high in mineral soil. 2. The carbon/nitrogen ratio in humin, humic acid content in organic matter, and carbon contents of humin in total carbon of soil organic matter were apparently higher in the volcanic ash soils than in the mineral soils, The total nitrogen and fractions of acid or alkali soluble nitrogen were remarkably high in volcanic ash soils while mineralizable nitrogen ($NH_4$-N and $NO_3$) contents were high in mineral soils. 3. The values of K600, RF and log K were also higher in volcanic ash soils than those in mineral soils, and the absorbance in the visible range were high and color was dark in the soil of which humification was progressed Extracted humic acid from volcanic ash soil was less reactive to the oxidizing chemical reagent and was persistance to the acid or alkali hydrolysises. 4. The major oxygen-containing functional groups in humic substances of volcanic ash soils were phenolic-OH alcoholic-OH and carboxyl groups while those in mineral soil were methoxyl and carbonyl groups. 5. Absorption spectra of alkaline solution of humic acid ranged from 200 nm to maxima 500 nm. Visible spectra peaks of from humic substances in the visible region were recognized at 350, 420, 450 and 480 nm. Only one single absorbance peak was observed in the visible region at 362 nm for Heugag series and two absorbance Peak were also at 360 nm and 390 nm for Yeungrag series. 6. Evolution of carbon as $Co_2$ was increased with addition of Na-pyrophosphate in Namweon and Heugag series, and "priming effects" took place on the soil organic matter decomposition by addition of rice straw with albumin in Ido series.