• Journal of Hydrogen and New Energy
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• v.17 no.1
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• pp.31-38
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• 2006

There are two types of metal hydride electrodes as a negative electrode in a Ni-MH battery, $AB_2$ Zr-based Laves phases and $AB_5$ LM(La-rich mischmetal)-based alloys. The $AB_5$ alloy electrodes have characteristic properties such as a large discharge capacity per volume, easiness in activation, long cycle life and a low cost of alloy. However they have a relatively small discharge capacity per weight. The $AB_2$alloy electrodes have a much higher discharge capacity per weight than $AB_5$ alloy electrodes, however they have some disadvantages of poor activation behavior and cycle life. Therefore, in order to improve the discharge capacity of the $AB_5$ alloy electrode the Zr, Ti and V which are the alloying elements of the $AB_2$ alloys were added to the $LaNi_{3.6}Ai_{0.4}Co_{0.7}Mn_{0.3}$ alloy which was chosen as a $AB_5$ alloy with a high capacity. The addition of Zr, Ti and V to $LaNi_{3.6}Ai_{0.4}Co_{0.7}Mn_{0.3}$ alloy improved the activation to be completed in two cycles. The discharge capacities of Zr 0.02, Ti 0.02 and V 0.1 alloys in $LaNi_{3.6}Ai_{0.4}Co_{0.7}Mn_{0.3}M_y$ (M = Zr, Ti, V) were respectively 346, 348 and 366 mAh/g alloy. The alloy electrodes, Zr 0.02, Ti 0.05 and V 0.1 in $LaNi_{3.6}Ai_{0.4}Co_{0.7}Mn_{0.3}M_y$ (M = Zr, Ti, V), have shown good cycle property after 200 cycles. The rate capability of the $LaNi_{3.6}Ai_{0.4}Co_{0.7}Mn_{0.3}M_y$ (M = Zr, Ti, V) alloy electrodes were very good until 0.6 C rate and the alloys, Zr 0.02, Ti 0.05 and V 0.1, have shown the best result as 92 % at 2.4 C rate. The charge retention property of the $LaNi_{3.6}Ai_{0.4}Co_{0.7}Mn_{0.3}M_y$ (M = Zr, Ti, V) alloys was not good and the alloys with M content from 0.02 to 0.05 showed better charge retention properties.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.4
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• pp.214-223
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• 2006

For better management of micronutrients in crop cultivation, the availability of micronutrients in the soils must be updated and evaluated as a first step. This study was conducted to investigate the distribution of micronutrients in soils of plastic film houses. Total 396 soil samples were collected from the plastic film houses of various crops in Yeongnam province (strawberry, 96; red pepper, 66; tomato, 74; oriental melon, 97; cucumber, 63). Total and available contents of B, Cu, Zn, Fe, and Mn in the soils were determined. Available B was extracted with hot water and available Cu, Zn, Fe, and Mn were extracted with 0.1 N HCl. Mean values of total contents of B, Cu, Zn, Fe, and Mn in the plastic film house soils were 25, 32, 74, 21,316, and $420mg\;kg^{-1}$, respectively. Total contents of micronutrients in the plastic film house soils were similar to those found in the open fields nearby, while they were different among the locations investigated. Mean contents extractable B, Cu, and Zn in the plastic film house soils were 2.1, 7.5, and $35mg\;kg^{-1}$, respectively. The contents of extractable B, Cu, and Zn in the plastic film house soils were higher than those found in the open fields nearby with exceptions of B in soils of strawberry and Cu in soils of red pepper and oriental melon. However, mean contents of extractable Fe and Mn in the plastic film house soils were 156 and $146mg\;kg^{-1}$, respectively, and the mean content of extractable Fe was much lower than that found in open fields nearby. The contents of extractable Zn, Fe, and Mn were higher than the sufficient levels for the crop requirements in most of the plastic film house soils investigated. Contents of extractable Cu in most soils of strawberry, tomato and cucumber cultivations were higher than the sufficient level. However, extractable Cu contents were below the sufficient level in about 30% of investigated soils of red pepper and oriental melon cultivation. Soils containing higher contents of extractable B than the sufficient level were relatively fewer in comparison to the other micronutrients.

• YAKHAK HOEJI
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• v.4 no.1
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• pp.12-13
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• 1959

The contents of trace elements of the 44 Korean women's hair samples are studied quantitatively by means of th ecircular paper chromatography method in this paper. The elements studied are Fe, Co, Cu, Ni, Mn, Mg, Ca, and Zn. The age distribution of subjectes and the results are shown in table 1 and 2.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.12
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• pp.601-605
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• 2004

In this paper, we investigated ionic impurities and physical properties by change of carbon black content, which is asemiconductive material for underground power transmission. Specimens were made into sheet form with three existing resins and nine specimens for measurement. The ionic impurities of the specimens were measured using anICP-AES (Inductively Coupled Plasma Atomic Emission Spectrometer), and the density of specimens was measured by a density meter. Specific heat (Cp) was then measured using aDSC (Differential Scanning Calorimetry). The ranges of measurement temperature were from 0[$^{\circ}C$] to 200[$^{\circ}C$], and heating temperature was 4[$^{\circ}C$/min]. Ionic impurities were measured to be high according to increases in the content of carbon black from this experimental result and density was also increased according to these properties. In particular, the impurity content values of A1 and A2, and existing resins, were measured at more than 4000[ppm]. Specific heat from the DSC results was lowered according to augmentation in the content of carbon black. The ionic impurities of carbon black containing Fe, Co, Mn, Al and Zn are forms of rapidly passed kinetic energy that increase the number of times breaking occurs during unit time with the near particles according to an increase in the vibration of particles by the applied heat energy.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.2
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• pp.138-144
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• 1996

This experiment was conducted to obtain the basic information on the morphological and physiological changes in tobacco leaf during the growth period by measuring the changes of chlorophyll, sugar, lipid and mineral contents in tobacco plant. Leaf length and width have been fully developed at 25 days after leaf emergence. Dry weight was rapidly increased between 10 and 15 days after leaf emergence and reached the highest at 30 days. Crude lipid content, palmitic acid, and the major saturated fatty acid were increased with progressing senescence, while unsaturated fatty acid including linolenic acid was decreased as the senescence was advanced. The total nitrogen content showed the highest value at IS days after leaf emergence. On the other hand, the total sugar content showed the highest value at 45 days after leaf emergence and glucose, fructose and sucrose were decreased with leaf development and increased at the end of senescence. The content of chlorophyll showed the highest value at 15 days after leaf emergence and began to decrease at 30 days after leaf emergence. The contents of p, Cu, Zn, and Fe in tobacco leaves were decreased by the end of senescence after leaf emergence but those of Ca, Mg, and Mn in leaves were increased. Key words : Nicotiana tabacum chlorophyll, fatty acid, senescence.

• Journal of Korea Foundry Society
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• v.35 no.1
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• pp.8-14
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• 2015

Variations of nickel contents and microstructures in molten magnesium alloys on the addition of aluminum, zirconium, and manganese have been investigated. Specimens were prepared by melting under $SF_6$ and $CO_2$ atmosphere and casting into a disc of 29 mm diameter with 7~10 mm thickness from the melt acquired at the top of crucible. Before casting, the molten metal was stirred for 3 minutes after each addition of alloying elements and maintained for 30 minutes for settling down. Results showed that zirconium did not significantly affect the content of nickel while aluminum remarkably reduced it by forming $Al_3Ni_2$ phase. When manganese are added to Mg-1wt%Ni alloy along with aluminum, both elements remarkably reduced the content of nickel. The addition of 1.5 wt% manganese to Mg-1wt%Ni alloy containing aluminum further reduced the content of nickel by more than 30%, during which an additional intermetallic phase $Al_{10}Mn_3Ni$ was precipitated in the molten magnesium.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.162-162
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• 2022

This study was carried out to investigate the effects of nitrogen, phosphorus, potassium (three main macro elements of fertilizer) on growth, yield and mineral contents of Platycodon grandiflorum for. duplux and to obtain the basic data of the proper fertilizer application for increasing the yield of P. grandiflorum for. duplux. Plant height showed significantly good results in all fertilization treatments compared to non fertilizer group (the control, T0), and in particular, the highest was 85.7 cm in the complete group (T4). Chlorophyll content showed a high amount in the range of 20.7 to 23.8 against all fertilization treatment groups, except for non fertilizer (T0) and non nitrogen (T1). The fresh weight of roots were higher quantity than other fertilization treatments in the complete group 55.8 g (T4). The mineral nutrient content ofNa, Mg, Cu and Al of the roots of P. grandiflorum for. duplux from T1 group showed the lowest amount compared to other groups. In addition, P from T2 group, Mn from T3 group and Ca, Fe, Zn from T4 group also exhibited the lowest mineral content compared to other groups respectively.

• 한국해양학회지
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• v.18 no.1
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• pp.29-42
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• 1983

This stidy was intended to investigate the heavy metal contents in the bottom sediments of the continental shelt around the Jeju Island and ot the southern coastal area of the Korean Peninsula. For this study 39 bottom sedinent samples were taken from the study area using Phleger gramity corer and Snapper. The average contents of heavy metals were 59.1 ppm Zn, 362.6 ppm Mn, 63.8 ppm Cr, 15.7 ppm Pb, 10.0 ppm Co, 28.9 ppm Ni, 10.5 ppm Cu, and 2.7% Fe in the surficial sediments around the Jejr Island; and 79.ppm Zn, 384 ppm Mn, 8.6 ppm Pb, 17.8 ppm Ni, 23.2 ppm Cu, and 1.59 % fe in those of nearsgore of the southern coastal area respectively. The heavy metal contents were higher in the northwestern part around the Jeju Island compared to those in other region. However, these tendencies were not the result of pollution, but of the differences of grain size of the sedimenrs. In the nearshore of the southern coast, the heavy metal contents did not show any geographical tendency. However, those of Masan and Jinhae Bays wew higher than those of the other region. These seemed to be caused by waste disposal from the industrial compsex located at the adjacent land. Nevertheless these values of heavy metal content except for Zn and Cu in Masan Bay and inner bay of Jinhae are lower than the average values of the each world-wide data of the nearshore sedimentl. The pair correlations of the cach heavy metal elements were calculated by regressino analysis using VAX 780 computer. the following pair elements, such as Zn-Cu, Ni-Cu, Fe-cu, Cr-Cu, Co-Zn, Ni-Zn, Cr-Zn, Ni-Co, Fe-Co, Cr-Co, Fe-Ni, Cr-Ni and Cr-Fe show closely posetive linear correlations in the sediments around the Jeju Island. In general, the heavy metal content increases in proportion to the increase of the mean values of the grain size of the sediments around the Jeju Island. In the southern coastal area, in gineral, thepair correlations of each heavy metal elements did not southern coastal area, in general, the pair correlatttttions of rach heavy metal elements did not show any positive correlation except for the positive linear correlations of Cu-Zn, Cu-ni and Ni-Mn. It is interpreted as a result of the differences of the physecochemical environment of the sampling sites and also of the influences of the ondustrial wastes from the manufacturing factores located at the coastal zone of the study area.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.4
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• pp.289-294
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• 2001

Yields of shells, appearance of the shellfishes, mineral contents of the shells and their hot water extracts were determined in six shellfishes such as corb shell(CS). short neck clam(SNC). taste clam(TC), ark shell(AS). top shell(TS) and oyster(OY) from the western coast of Korea. Yields of shells in shellfishes were 70.I~80.5% but yields of TC was the lowest as 40.7%. The highest among weight of the shell the shellfishes was the TS(26.2g) and the lowest weight was TC(5.6g) Colors of CS, SNC, TC. AS. TS and OY were yellowish brown, brown, black. greenish brown and gray. respectively. Ca content of the shell of shellfishes was 36.23~38.78% and the content of K and Na were 0.23~4.54% and 1.48~l.59%, respectively. Contents of Na, Mg, Fe. Mn, Zn, Cu. P and S were in the range of 0.01~0.21%. It also contained heavy metals, such as Pb(1.90~7.75 ppm), Cd(0.5~4.50 ppm), As (1.40~4.30 ppm), Se (0.2~l.50 ppm). Cr(1.00~8.30 ppm) and Hg(0.002~8.2 ppm), Ca content in hot water extracts of shell of shellfish was the highest in TC(2,448 mg/100 g), and the lowest in SNC(115 mg/100 g). K content in TC extracts was the highest with the levels of 952 mg/100 g. P content of TC and SNC were 201 and 0.36 mg/100 g, respectively. The contents of Pb, As, Se and Cr were the highest in the extracts of TC and were 110. 40. 90, 20 $\mu$g/100 g, respectively. But Cd was not detected in the extracts of SNC.

• Journal of the Korean Ceramic Society
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• v.29 no.7
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• pp.577-585
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• 1992

TiB2 and TiC were prepared from the mixture of metal titanium, boron and graphite powders in Argon atmosphere by Self-propagating High-temperature Synthesis method. The sintered properties of TiB2-TiC composite as a function of TiC content and sintering temperature were investigated in TiB2 matrix. The sintered properties were the most excellent at 10 wt% TiC content in TiB2-TiC composite. The relative density, M.O.R strength, hardness and fracture toughness of TiB2-10 wt% TiC composite sintered at 190$0^{\circ}C$ for 90 min by hot-pressing under the pressure of 30 MPa were 98.6%, 634 MPa, 2128.1 kg/$\textrm{mm}^2$ and 4.09 MN/m3/2, respectively.