• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.2
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• pp.78-83
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• 2012

The structural change and the electrical conductivity with Sr content in $La_{1-x}Sr_xMn_{0.8}Cu_{0.2}O_3$ (LSMCu) were studied. $La_{0.8}Sr_{0.2}MnO_3$ (LSM) and $La_{1-x}Sr_xMn_{0.8}Cu_{0.2}O_3$ ($0.1{\leq}x{\leq}0.4$) were synthesized by EDTA citric complexing process (ECCP). A decrease in the lattice parameters and lattice volumes was observed with increase of Sr content, and these results were attributed to the increasing $Mn^{4+}$ ions and $Cu^{3+}$ ions in B-site. The electrical conductivity measured from $500^{\circ}C$ to $1000^{\circ}C$ was increased with increase of Sr content in the $0.1{\leq}x{\leq}0.3$ composition range, and it was 172.6 S/cm (at $750^{\circ}C$) and 177.7 S/cm (at $950^{\circ}C$, the maximum value) in x = 0.3. The electrical conductivity was decreased in x = 0.4 because of the presence of the second phase in the grain boundaries. The lattice volume was contracted by increase of $Mn^{4+}$ ions and $Cu^{3+}$ ions in B-site according to increase of Sr content and the electrical conductivity was increased with increase of charge carriers which were involved in the hopping mechanism.

• Journal of agricultural medicine and community health
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• v.8 no.1
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• pp.44-65
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• 1983

As a part of the epidemiological studies of clonorchiasis, this study was conducted to evaluate the current endemicity and the natural transition of the Clonorchis infection in Gimhae Gun and delta area a high endemic area in Korea in recent years, prior to the introduction of praziquantel which will eventually influence the status of the prevalence. The data obtained in this study in 1983 were evaluated for natural transition of the infection in comparison with those obtained 16 years ago in 1967 by the author(Kim, 1974). The areas of investigation, villages and schools surveyed, methods and techniques used in this study were the same as in 1967, except for the contents of the questionnaire for raw freshwater fish consumption by the local inhabitants. 1) The prevalence rate of clonorchiasis in the general population of the villages was 48.1% on the average out of a total of 484 persons examined. The average of those of the riverside-delta area was 65.2% and 43.0% in the inland area. Among the schoolchildren, the prevalence rate was 8.2% on the average out of a total of 1,423 examined. By area, the prevalence rate was 10.8% in the riverside delta area and 2.8% in the inland area. By sex, difference in the prevalence was seen only in the inhabitants of the inland area showing 52.4% in the male and 33.5% in the female. 2) In the natural transition of the infection, the prevalence rate among the inhabitants has decreased from 68.8% in 1967 to 48.1% in 1983, and in the schoolchildren from 56.4% in 1967 to 8.2% in 1983. The reduction rate was higher in the riverside-delta area than in the inland area. 3) In the prevalence rate by age, 11.9% was first seen in the 5-9 age group and the rate gradually increased up to 75.0% in the 50-59 age group. By sex, the rate was higher in the male than in the female in the 20-29 age group and over. 4) In the natural transition of the prevalence rate by age, the reduction rate of the infection during the past 16 years was greater in the younger age groups up to the 40-49 age group and reached the same level in the age group 50-59. Reduction was seen again in the age group over 60s. By sex, the reduction rate was greater in the female than in the male in the 20-29 age group and over. By area, the reduction rate was greater in the riverside delta area than in the inland area, particularly in the young age groups. 5) In the intensity of the infection among the cases, the mean egg out-put per mg feces per infected cases(EPmg) in the inhabitants was 6.3. EPmg of those of the river-side-delta area was 15.4 and that of the in-land was 2.8. On the other hand, in the schoolchildren, EPmg was 3.2, and no difference was seen between the two areas, the river-side-delta area and the inland area. 6) In the transition of the intensity of the infection by area, EPmg among the inhabitants inexplically increased from 7.8 in 1967 to 15.4 in 1983. This was probably caused by uneven specimen collection in the process of sampling the population. EPmg of the inhabitants in the inland area and those of the schoolchildren of both riverside delta and inland areas showed a similar decrease in the past 16 years. 7) The intensity of the infection by age showed a relatively low level in the 20-29 age group and below, and EPmg 5.1-9.5 was seen in the 30-39 age group and over. Sex, Epmg was 5.8 in the male and 4.7 the female. By in 8) In the transition of the intensity of the infection, EPmg decreased from 6.2 in 1967 to 5.4 in 1983. By age, in contrast to the figures of 1967 in which EPmg gradually increased with some fluctuation from 1.1 in the 0-4 age group to peak 10.5 in the 50-59 age group, in 1983 lower intensity of the infection was seen in the age group from 10-14 to 20-29 with the EPmg range of 0.6-2.7. 9) In the distribution of the clonorchiasis cases by the range of EPmg value, 43.2% of the cases were in 0.1 0.9 and 34.6% in 1.0-4.9. As a whole by cumulative percent, 44.6% of them were under 0.9 as light infection and 86.1% of them under 9.9 up to moderate infection. By sex, no difference was seen in Epmg. 10) In the transition of the distribution by the range of Epmg, the cases were distributed up to the range 80.0-99.9 in 1967 and to 60.0-79.9 in 1983. By cumulative percent, in the range of 0.1-0.9 and less, light infection, 34.3% of them were distributed in 1967 and 44.6% in 1983 with about 10% increase. In the range of 5.0-9.9 and less, up to moderate infection, 83.2% in 1967 and 86.1% in 1983 of the cases were seen, respectively. 11) The practice of raw freshwater fish consumption among the inhabitants seems to have decreased in recent years. Those who admitted to raw freshwater fish consumption in the last two years among the infected inhabitants were 59.3%, although 86.8% of them professed to have experience with raw freshwater fish consumption. 31.7% of those who have had experience of the raw freshwater fish consumption denied any further consumption in recent years. From an interview of 543 school-children, 24.1% of them admitted to an experience of raw freshwater fish consumption. However, those who have practised in the past two years comprized 17.9%. Those who denied raw freshwater fish consumption in recent years among those who had such experience were 26.0% out of 131 interviewed. The rate of raw freshwater fish consumption in both inhabitants and schoolchildren were higher in the male than in the female. On the contrary, the rate of those who did not practise in recent years among those who had experience of raw freshwater fish consumption was higher in the female than in the male. 12) The major reason for the reduction of raw freshwater fish consumption among the local inhabitants was the risk of the fluke infection. However, it has become apparent that such change of taste has resulted from water pollution impact which has affected throughout the areas of the freshwater systems in this locality since last several years. 13) In animal survey, Clonorchis infection was seen in 14.8% of 88 dogs examined and 3.7% of 27 house rats examined. It was noted that populations of dogs and cats have increased in the villages surveyed. Although the prevalence rate was lower in the present survey than those of 1967, the significance of the animals as the reservoir host has not changed. 14) Prevalence rate of Clonorchis infection by cercariae in the first intermediate host, Parafossarulus manchouricus, was 0.6% out of 517 snails examined. The infection rate was lower in comparison with 2.3% out of 2,124 examined in 1967. Moreover, sharp decreases in number and distribution of the intermediate host snails in many watershed areas of the huge freshwater systems in this locality seemed to reduce transmission of Clonorchis in connection with the intermediate host stage of its life cycle. 15) Clonorchis infection in the second intermediate fish hosts was relatively low. The mean number of Clonorchis metacercaria per fish in Pseudorasbora parva was 517 in 1983, whereas it was 1943 in 1968 through 1969. Environmental water pollution has also caused the decreased fish population density in these areas, and this has also apparently affected to the practice of raw freshwater fish consumption among the local inhabitants. 16) In conclusion, endemicity of Clonorchis infection in Gimhae Gum and delta area of the Nagdong River has sharply decreased during the past 16 years. The major cause of the regressive transition of the infection was the water pollution of the land water systems of this locality. The pollution has upset the ecosystems comprizing of the intermediate hosts of Clonorchis in many areas, and also affected to a significant extent to the discontinuance of the local inhabitants for raw freshwater fish consumption.

• The Korean Journal of Food And Nutrition
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• v.30 no.2
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• pp.236-242
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• 2017

Chia (Salvia hispanica L.) seed, originated from Central America, is a nutritious food especially rich in dietary fiber and protein. In this study, we investigated the quality and sensory characteristics of Yanggang with chia seed powder (CSP). Red bean paste was replaced with CSP at 0% (Control), 1% (CSP1), 2% (CSP2), 3% (CSP3) and 4% (CSP4). The pH values of chia seed Yanggang tended to decrease from Control (6.84) to CSP4 (6.67); whereas, the moisture contents of Yanggang samples tended to increase. The soluble solid contents of CSP4 were the highest ($3.33^{\circ}Bx$), as compared to the Control which showed the lowest values ($2.77^{\circ}Bx$). In the CSP-added groups, the L-value (lightness), a-value (redness) and b-value (yellowness) were increased, while the ${\Delta}E$ (total color difference) was decreased, as compared to the control group. Hardness and springiness were both increased from control ($49.77g/cm^2$ and 464.80%, respectively) to CSP4 ($72.21g/cm^2$ and 532.43%, respectively). However, cohesiveness decreased from control (47.41%) to CSP4 (37.34%). Chewiness and adhesiveness showed no significant group-wise difference (p<0.05). Total polyphenol content ranged from 7.23 to 10.73 mg GAE/100 g, with a lower ABTS $IC_{50}$ of the CSP-added groups than that of the control group. Samples from the CSP-added as well as Control groups showed no significant differences among all items on the sensory evaluation test, except flavor. The results indicated that CSP had significant effects on the soluble solid contents and texture of Yanggang. Thus, the addition of 2% of CSP is desirable for making Yanggang.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.526-533
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• 2006

This study was carried out to investigate the efficacy of strong acidic electrolyzed acid water (SAEW; Strong acidic electrolyzed water, pH 2.76, ORP 1,128 mV, HClO 105.0 ppm) and low alkaline electrolyzed water (LAEW; Low alkaline electrolyzed water, pH 8.56, ORP 660 mV, HClO 73.8 ppm) as storing liquid for peeled lotus root. During storage at $5^{\circ}C$, it was showed that SAEW and LAEW inhibit growth of microorganisms until at least 5 days of storage. Total phenolic contents, polyphenol oxidase (PPO) activity, and color differences value $({\Delta}E)$ of peeled lotus roots stored in SAEW and LAEW were lower than that of one stored in TW (tap water). The hardness decrement of lotus roots stored in SAEW and LAEW were lower than that of lotus root stored in TW too. Contents of moisture crude protein crude fat, crude ash, crude fiber, and total sugars were gradually decreased during storage. Whereas vitamin C content of lotus root stored in 0.6% acetic acid was most rapidly decreased to 25% as compared with one of initial days of storage that of lotus roots stored in SAEW and LAEW was not decreased significantly as compared with one stored in TW. Sensory characteristic during storage was preferable on lotus root stored in SAEW to the other treatments.

• Journal of the Korean Chemical Society
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• v.36 no.4
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• pp.511-516
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• 1992

The x-values of the nonstoichiometric compound YbO$_x$ have been measured in a temperature range of 600 to 1150$^{\circ}C$ under oxygen partial pressure of 1.00 ${\times}$ 10$^{-2}$ atm∼atmospheric air pressure. The values are varied between 1.55453 and 1.60794 in the conditions. The enthalpy of the formation for x' in YbO$_{1.5＋x'}$(${\Delta}$H$_f$) was 1.55, 1.18, and 1.05 kJ/mol under the above conditions, respectively. The electrical conductivities of the oxides or ${\sigma}$ have been measured in the temperature range from 600 to 1100$^{\circ}C$ under oxygen partial pressure of 1.00 ${\times}$ 10$^{-5}$ ∼ 2.00 ${\times}$ 10$^{-1}$ atm. They varied from 10$^{-9}$ to 10$^{-5}$ ohm$^{-1}$ cm$^{-1}$ within the semiconductor range. The Arrhenius plots of the electrical conductivities show a linearity and the activation energy for the conduction was about 1.7eV. The oxygen partial pressure dependence of the conductivity or 1/n value increases with the pressure. The nonstoichiometric conduction mechanism of the oxide was discussed in terms of the x values, ${\sigma}$ values, and the thermodynamic data.

• Food Engineering Progress
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• v.15 no.4
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• pp.382-387
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• 2011

Physicohemical properties of dual-modified rice starches, cross-linked (with $POCl_{3}$) and hydroxypropylated (with propylene oxide) rice starches, were studied. Rice starch was cross-linked using $POCl_{3}$ (0.005%, 0.02% (v/w)) at 45$^{\circ}C$ for 2 hr and then hydroxypropylated using propylene oxide (2%, 6%, 12% (v/w)) at 45$^{\circ}C$ for 24 hr, respectively. Swelling power, solubility, thermal properties (DSC) and pasting properties (RVA) of cross-linked and hydroxypropylated (CLHP) rice starches were determined. Swelling power of CLHP rice starch increased at relatively lower temperature than native rice starch. Solubility of CLHP rice starch was lower than that of native rice starch. Peak viscosity of CLHP rice starch was lower than that of native starch while holding strength and final viscosity were increased with modification. Breakdown value was lower and setback value was higher than native rice starch. DSC thermal transitions of CLHP rice starch shifted toward lower temperature. Amylopectin-melting enthalpy of CLHP rice starch decreased, whereas it was not affected by the amount of $POCl_{3}$.

• Journal of the Korean Mathematical Society
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• v.47 no.6
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• pp.1147-1165
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• 2010

In this paper we compare a torsion free sheaf F on $P^N$ and the free vector bundle $\oplus^n_{i=1}O_{P^N}(b_i)$ having same rank and splitting type. We show that the first one has always "less" global sections, while it has a higher second Chern class. In both cases bounds for the difference are found in terms of the maximal free subsheaves of F. As a consequence we obtain a direct, easy and more general proof of the "Horrocks' splitting criterion", also holding for torsion free sheaves, and lower bounds for the Chern classes $c_i$(F(t)) of twists of F, only depending on some numerical invariants of F. Especially, we prove for rank n torsion free sheaves on $P^N$, whose splitting type has no gap (i.e., $b_i{\geq}b_{i+1}{\geq}b_i-1$ 1 for every i = 1,$\ldots$,n-1), the following formula for the discriminant: $$\Delta(F):=2_{nc_2}-(n-1)c^2_1\geq-\frac{1}{12}n^2(n^2-1)$$. Finally in the case of rank n reflexive sheaves we obtain polynomial upper bounds for the absolute value of the higher Chern classes $c_3$(F(t)),$\ldots$,$c_n$(F(t)) for the dimension of the cohomology modules $H^iF(t)$ and for the Castelnuovo-Mumford regularity of F; these polynomial bounds only depend only on $c_1(F)$, $c_2(F)$, the splitting type of F and t.

• Korean journal of food and cookery science
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• v.11 no.2
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• pp.126-132
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• 1995

This study was undertaken to determine effect of parboiling on physical and cooking characteristic properties of milled rice. Equilibrium moisture content(EMC) of parboiled rice soaked at room tempe-rature(25$^{\circ}C$) and high temperature(75$^{\circ}C$) increased 1.8∼2.7 times & 1.4∼l.6 times as compare to raw rice, and time to reach EMC of parboiled rice became longer 4 times and 1.7 times than raw rice respectively. Equilibrium volume(EV), time to reach EV and volume increase rate constants(ku) were similar to EMC, time to reach EMC, and k. kv of parboiled rice brought about in decrease at room temperature and increase at high temperature. The geletinization temperature, time and peak viscosity of parboiled rice were higher than those of raw rice. Parboiling brought about in decrease in L/W of cooked parboiled rice kernels and L/W increased according to presoaking time was prolo-nged. Solid content of cooking water of raw rice were higher than those of parboiled rice. Hardness of uncooked PL20 & PL40 soaked for 30 min was higher than that of raw rice but that of uncookef parboiled rice soaked for 90 min was lower than that of raw rice. Springness of cooked parboile rice for initial 10 min decresed with that of cooked raw rice and then increased sharply, cooked f, r 15 min then increased slowly, cooked parboiled rice for 40 min increased more than cooked raw rice. Color differences($\Delta$I) of PT2O samples was the lowest L value of all the samples increased but a and b value decreased according to milling degree was high.

• Food Science and Preservation
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• v.13 no.1
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• pp.1-7
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• 2006

The effects of packaging material and method on quality of fresh-cut mushrooms (Agaricus bisporus Sing.) were investigated in terms of weight loss, surface color, phenolics, vitamin C and sensory characteristics during storage at $5^{\circ}C$. The fresh-cut mushrooms were subjected to passive, gas exchange and vacuum packaging conditions at st. Polyethylene film (PE), polypropylene film (PP), anti-fogging film (AP) and pen orated film (PF) were used for the passive packaging. The mixed gas of $5\% CO_2/\;2\%O_2$ (MA1) and $10\%CO_2/\;2\%O_2$(MA2) were applied for the gas exchange packaging. The respiration rate of sliced mushroom was 1.27 times higher than intact mushroom at $5^{\circ}C$. Gas concentrations in the passive packaging were $1-2\%\;O^2\;and\;5-16\%m$ during storage of sliced mushrooms for 14 days at $5^{\circ}C$, and levels of the gases were different by the films used The mushroom in perforated film (PF) showed the highest weight loss of $4.56\%$. Anti-fogging film (AF) was somewhat effective for prevention of the weight loss compared with other films after 14 days storage. The mushrooms in MA1 and MA2 packages showed lower delta L value than in other films. PE packaging mitigated decrease of free and bound phenolics during storage. The mushrooms in MA2 kept better quality in sensory aspect, and then in MA1, PE and PP in order during storage at $5^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.29 no.1
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• pp.65-72
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• 2016

Black tomato (Lycopersicum esculentum) is known to have more ${\beta}-carotene$, lycopene, and vitamin C than general red-colored tomatoes. In this study, we evaluated the quality properties, antioxidant activities and sensory characteristics of black tomato cookies. Cookies were prepared by replacing 0, 1, 3, 5, and 7% of flour with black tomato powder. Density of black tomato cookies tended to be decreased between control (1.20) and 3% added groups (1.12). pH value was decreased from control (6.66) to 7% added group (5.16). Spread factor and loss rate were increased with increasing amounts of black tomato powder. Hardness was gradually increased from $107.77g/cm^2$ in control to $170.50g/cm^2$ in 7% added group. Color measurement indicated that L-value (brightness) was highest in control (70.46) and lowest in 7% added group (45.23); whereas, a-value (redness) increased while b-value (yellowness) tended to decrease with increasing amounts of black tomato powder. Total polyphenol contents and DPPH radical scavenging activities were directly proportional to the amount of black tomato powder. Consumer preference scores in color and flavor of black tomato powder added group were higher than those of control. Characteristic strength test was not significantly different among the groups. Overall, the results indicated that adding 5% black tomato powder is desirable for making black tomato cookies.