• Journal of Nutrition and Health
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• v.41 no.8
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• pp.718-732
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• 2008

The purpose of this study was to investigate nutrients or food factors related to cognitive function of elderly having Alzheimer's disease. In this study 38 subjects who were over 65 years old have participated in dementia clinic at A medical center. After they were diagnosed to Alzheimer's Disease (AD) through blood analysis, neuropsychological test, brain image and interview by medical specialist, we examined for their general information, anthropometry, blood pressure and dietary intakes. Dietary intakes were investigated using the 24-hour recall record. Energy intake was adequate and the energy composition of carbohydrate, protein and fat was 60.8 : 16.2 : 23.0, but dietary intakes of calcium, vitamin A and folate were less than 75% of the recommended intake levels for Koreans. The multiple regression analysis adjusted with age, sex and educational level showed that cognitive function was positively related to intakes of zinc, fishes and shellfishes, beans & nuts, sugars and fats, and negatively related to intakes of plant calcium and eggs. These results indicate that intakes of specific nutrients or food groups are associated with the specific domains of cognitive function in elderly with AD.

• Economic and Environmental Geology
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• v.35 no.2
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• pp.97-102
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• 2002

Ce-pyrochlore (CaCe $Ti_2 $O_7)was synthesized to study its properties and phase relations in CaO-Ce $O_2$-Ti $O_2$ system because Ce-pyrochlore was known as a promising material for the immobilization of radioactive actinide. The samples were prepared from the high purity starling materials under the pressure of 200~400 kg/$\textrm{cm}^2$ at room temperature, and annealed at 1000~ 150$0^{\circ}C$. The Synthesized samples were analysed and indentified with XRD and SEM/EDS methods. The optimal formation condition of Ce-pyrochlore was at 130$0^{\circ}C$ under $O_2$ atmosphere and the chemical composition of it wasCa$Ca_{1-x}Ti_{2-y}O_{7-x-2y}$(x=0.03-0.05, y=0.02~0.04) At temperature between 130$0^{\circ}C$ 140$0^{\circ}C$, Ce-pyrochlore underwent rapidly the incongruent decomposition to perovskite. Ce-perovskite, a partial solid solution between perovskite and loparite (C $e_{0.66}$Ti $O_3$), was observed as a major phase above 140$0^{\circ}C$.>.

• Journal of the Korean Chemical Society
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• v.17 no.5
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• pp.337-345
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• 1973

The nonstoichiometry of the iron oxide system has been studied by analyzing the weight loss of a sample, measured by using a quartz microbalance, in a temperature range from $0^{\circ}C$ to $1200^{\circ}C$ under oxygen pressures from $10^{2}mmHg$ to $10^{-4}mmHg$. The Y values of the formula, $FeO_{1+\gamma}$, that have been obtained by this means for various conditions of temperature and pressure in this range are considered to be more accurate than values obtained by methods requiring thste quenching of the sample before measurements are made. The plots of log Y vs $log PO_2$ (or $log Y =_n log PO_2$) show linearity and n calculated from the slope of the plot is about 1/10 at $1000^{\circ}C$, indicating a difference between the nonstoichiometric and oxidation mechanisms. The condition for the formation of stoichiometric FeO was determined to be $1200^{\circ}C$ under $10^{-3}mmHg$ of $O_2$ and the composition of the oxide under standard conditions was $FeO_{1.11185}$. As in general more oxygen dissolves into the oxide system at lower temperatures and higher oxygen pressures, the deviation from stoichiometric FeO is greater under those conditions. A comparison of the change in conductivity of the sample indicates that full phase transition does not take place with conductivity transition.

• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.5-6
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• 2002

The new spectrometer for X-ray Induced Electron Emission Spectroscopy (XIEES) .has been recently developed in KRISS in collaboration with PTI (Russia). The spectrometer allows to perform research using the XAFS, SXAFS, XANES techniques (D.C.Koningsberger and R.Prins, 1988) as well as the number of techniques from XIEES field(L.A.Bakaleinikov et all, 1992). The experiments may be carried out with registration of transmitted through the sample x-rays (to investigate bulk samples) or/and total electron yield (TEY) from the sample surface that gives the high (down to several atomic mono-layers in soft x-ray region) near surface sensitivity. The combination of these methods together give the possibility to obtain a quantitative information on elemental composition, chemical state, atomic structure for powder samples and solids, including non-crystalline materials (the long range order is not required). The optical design of spectrometer is made according to Johannesson true focusing schematics and presented on the Fig.1. Five stepping motors are used to maintain the focusing condition during the photon energy scan (crystal angle, crystal position along rail, sample goniometer rail angle, sample goniometer position along rail and sample goniometer angle relatively of rail). All movements can be done independently and simultaneously that speeds up the setting of photon energy and allows the using of crystals with different Rowland radil. At present six curved crystals with different d-values and one flat synthetic multilayer are installed on revolver-type monochromator. This arrangement allows the wide range of x-rays from 100 eV up to 25 keV to be obtained. Another 4 stepping motors set exit slit width, sample angle, channeltron position and x-ray detector position. The differential pumping allows to unite vacuum chambers of spectrometer and x-ray generator avoiding the absorption of soft x-rays on Be foil of a window and in atmosphere. Another feature of vacuum system is separation of walls of vacuum chamber (which are deformed by the atmospheric pressure) from optical elements of spectrometer. This warrantees that the optical elements are precisely positioned. The detecting system of the spectrometer consists of two proportional counters, one scintillating detector and one channeltron detector. First proportional counter can be used as I/sub 0/-detector in transmission mode or by measuring the fluorescence from exit slit edge. The last installation can be used to measure the reference data (that is necessary in XANES measurements), in this case the reference sample is installed on slit knife edge. The second proportional counter measures the intensity of x-rays transmitted through the sample. The scintillating detector is used in the same way but on the air for the hard x-rays and for alignment purposes. Total electron yield from the sample is measured by channeltron. The spectrometer is fully controlled by special software that gives the high flexibility and reliability in carrying out of the experiments. Fig.2 and fig.3 present the typical XAFS spectra measured with spectrometer.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.339-350
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• 2009

This study was carried out to investigate distributional condition of rare plants and useful plant resources, and to verify distributional patterns of understory vegetation associated with the upper layer's vegetation structure. Total 59 families, 160 genera, 218 kinds of vascular plants were identified at the study site including 6 rare plants designated by Korea Forest Service (Lloydia triflora Bak., Trillium kamtschaticum Pall., Lilium distichum Nakai, Anemone koraiensis Nakai, Iris odaesanensis Y.N. Lee, Viola diamantica Nakai). Twenty three species of useful plant resources were also identified at the site; 8 of them showed clustered distributions and the others were prone to scatter. Actual vegetation of this study area consisted of one natural community dominated by Quercus mongolica Fisch. and three disturbed communities of Larix kaempferi (Lamb.) Carriere, Abies holophylla Max. and/or a herbaceous vegetation resulting from forest removal and strong wind of mountain top. This classification was strongly supported by cluster analysis based on the surveyed plot data. Distributional patterns of understory vegetation within forest stand were somewhat related to overstory vegetation structure, but showed a different tendency according to site condition, species composition, and competitive pressure among understory vegetation. Therefore, in order to protect the important understory components as forest genetic resources, forest treatments such as density control of overstory should be implanted based on understanding of impact on understory's dynamics and growing condition.

• Journal of the Korean Chemical Society
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• v.43 no.4
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• pp.438-446
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• 1999

The optimum analytical method of aldehydes, ozone by-products, was established by reverse phase liquid chromatography. Six aldehydes including formaldehyde, acetaldehyde, acrolein, propionaldehyde, butylaldehyde and benzaldehyde, and one ketone including acetone were selected as aldehyde test samples through preliminary experiments. Such analytical conditions as the pH of citrate buffer solution, reaction temperature, reaction time, and concentration of DNPH, the component and composition of desorption solvent were optimized. As the result, pH 3.0 of citrate buffer solution, 40$^{\circ}C$ of reaction temperature, 15 minutes of reaction time, and 0.012% of DNPH concentration were chosen as optimum conditions. Aldehydes-DNPH derivatives in water were concentrated on $C_18$ Sep-Pak cartridge and followed by elution of their derivatives fraction with THF/ACN(70/30) mixture, and showed recoveries of the range from 87 to 107%. Separation condition on Nova-Pak $C_18$ column with low pressure gradient elution from ACN/MeOH/water(30/10/60) of an initial condition to 80% ACN of a final condition was found to give a good resolution within 20 minutes of run time. 86% to 103% of recovery for aldehydes using this method was similar to that for aldehyde using EPA Method 554 which is ranged from 84% to 103%.

• Journal of the Korean Chemical Society
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• v.40 no.5
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• pp.295-301
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• 1996

A series of solid solutions of the $CaGa_1-xFexO_3-y$ system with the compositions of x=0.25, 0.50, 0.75, and 1.00 has been prepared at $1150^{\circ}C$ under an atmospheric air pressure. The structure, nonstoichiometric chemical formula, and the distribution of cations for the solid solutions are determined by X-ray diffraction analysis, Mohr salt titration, Mossbauer spectroscopic analysis. Their physical properties are discussed with electrical conductivity and magnetic measurements. The crystal system of all the compositions is a brownmillerite orthorhombic system from the X-ray diffraction analysis and the reduced lattice volume increases linearly with x value except that of the composition of x=0.25. All the solid solutions do not contain $Fe^{4+}$ ion and the mole number of oxygen vacancies or y value is 0.50 from Mohr salt analysis. The oxidation state of Fe ion, the coordination state, the structure change in the Brownmillerite-type structure, and the distribution of $Ga^{3+}$ and $Fe^{3+}$ ions are discussed with Mossbauer spectroscopic analysis. The electrical conductivity increases and activation energy decreases, as x value increases. The traditional semiconducting property of this system is described in terms of band theory. The compositions of x=0.50∼1.00 show a thermal magnetic hysteresis in the magnetic measurement with the cooling conditions, which is discussed in terms of the space group and Dzyaloshinsky-Moriya interaction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.259-262
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• 1984

In order to examine the effect of oil extraction methods on the charateristics of sesame oil, the fractionation pattern and fatty acid compositions of the each fraction of the oil were compared in the oil extracted by the three different extraction methods, that is, pressure extraction of roasted seed (RTP), acetone extraction of roasted seed (RTE) and acetone extraction of raw seed (RWE). The amount of triglyceride in RWE oil was slightly higher as 77.2% of the total lipid than that in RTP and RTE oil of 73.4%. The content of oleic and linoleic acid in glycolipld and fatty acid fractions, linoleic acid in triglyceride, and palmitic and stearic acid in phospholipid fractions from RTP and RTE oil were higher than those from RWE oil, but the oleic acid in triglyceride. Palmitic and stearic acid in free fatty acid, and oleic and linoleic acid in phospholipid from RTP and RTE oil were lower than those from RWE oil. The ratio of $C_{18}$ to $C_{16}$ fatty acids and unsaturated to saturated fatty acids in glycolipid and phospholipid fractions from RTP and RTE oil were higher than those from RWE oil, but the ratios in triglyceride and free fatty acid fractions from RTP and RTE oil were lower than those from RWE oil.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.1
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• pp.19-27
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• 2014

Mg hydride has a high hydrogen capacity (7.6%), at high temperature, and is a lightweight and low cost material, thus it a promising hydrogen storage material. However, its high operation temperature and very slow reaction kinetics are obstacles to practical application. In order to overcome these disadvantages of Mg hydride, graphene powder was added to it. The addition of graphene has been shown to reduce the operating temperature of dehydrogenation. Moreover, in this report the environmental aspects of $MgH_x$-Graphene composites are investigated by means of the environmental life cycle assessment (LCA) method. $MgH_x$-Graphene mixture was prepared by hydrogen induced mechanical alloy (HIMA). The synthesized powder was characterized by XRD(X-ray Diffraction). The hydrogenation behaviors were evaluated by using a Sievert's type automatic PCT apparatus. Such evaluation of Materials also conducted in the LCA. From the result of P-C-T(Pressure-Composition-Temperature) curves, the $MgH_x$-3wt.% graphene composite was evaluated as having a 5.86wt.% maximum hydrogen storage capacity, at 523K. From absorption kinetic testing, the $MgH_x$-7wt.% graphene composite was evaluated as having a maximum 6.94wt.%/ms hydrogen absorption rate, at 573K. Environment evaluation results for the $MgH_x$-graphene composites and other materials indicated environmental impact from the electric power used and from the materials themselves.

• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.236-242
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• 2005

Membrane fouling by protein mixtures during microfiltration has been investigated for binary mixtures of bovine serum albumin (BSA), casein, lysozyme, pepsin, and ovalbumin. Filtration experiments were carried out using $0.2{\mu}m$ polycarbonate track-etched (PCTE) membrane in a stirred cell under constant transmembrane pressure (14 kPa) and concentration of hydrogen ion (pH=11) to study the effect of mixture composition on filtrate flux decline. Flux decline data were analyzed using a pore blockage-cake formation model developed recently. It was found that the model is in a good agreement with the experimental data. Fouling parameters such as the rate of pore blockage(${\alpha}$), the initial resistance of the protein deposit ($R_{po}$) and the increasing rate of the protein layer resistance(${\beta}$) were used to evaluate the rate of filtrate flow by membrane fouling in the binary mixture system. Generally, the trend of ${\alpha}$ is comparable with that of filtrate flux decline. It was also found that fast flux decreasing was observed over the binary mixture containing casein. The result is due to high value of the initial resistance of the protein deposit ($R_{po}$) over casein.