• Journal of Ecology and Environment
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• v.34 no.3
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• pp.279-286
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• 2011

The effect of allelochemicals on growth, root nodule nitrogen fixation activity, and ion patterns of soybeans were investigated. We prepared 50 g/L (T50), 100 g/L (T100), and 200 g/L (T200) extract concentrations by soaking fresh red pine needles in a nutrient solution. Adding needles to the nutrient solution increased the content of total phenolic acids, osmolality, and total ions. The total phenolic content in the T50, T100, and T200 extracts were $206{\pm}12.61$, $335{\pm}24.16$, and $603{\pm}12.30$ mg gallic acid equivalents, respectively. The $K^+$, $Mg^{2+}$, $Ca^{2+}$, and $PO_4^{3-}$ content increased by adding needles to the nutrient solutions, whereas $SO_4^{2-}$ content decreased. The growth inhibition of soybeans was proportional to the needle extract concentrations, and the T100 and T200 concentrations resulted in remarkable growth inhibition. On day 20 after treatment, dry weight and nitrogen fixation activity of the root nodules were reduced by the T100 and T200 treatments, whereas the T50 treatment was not difference from the control. After day 10, total ion content in all treatment groups was not different in comparison with the control. However, total ionic content in all treatment groups decreased significantly compared with that in the control after day 20. The lowest total ion value was found for the T200 concentration. The T200 treatment also resulted in significantly reduced $SO_4^{2-}$ content. The amounts of $Mg^{2+}$, $Ca^{2+}$, and $Mn^{2+}$ were higher than those of the control for the T50 treatment on day 10 and for T100 on day 20 after treatment. A significant increase in osmolality was observed in the T200 treatment on day 10 and in the T100 treatment on day 20. These results suggest that under severe allelochemical stress conditions, a remarkable reduction in nodule formation, nitrogen fixation activity, and ion uptake eventually resulted in a decrease in leaf production. Furthermore, increased $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Mn^{2+}$, and osmolality in soybeans exposed to lower concentrations of allelochemicals than the critical stress level helped overcome the stress.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.162-170
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• 1998

The dose response effects of different levels of wheat barn (WB) supplementation to a rice straw based diet has been studied in growing native (Bos indicus) bulls of Bangladesh. Twelve bulls of $266{\pm}29.6kg$ live weight and $32{\pm}9.5$ months old were given either of three diets of ad libitum untreated rice straw alone (T1) or straw supplemented with 2 (T2) or 3 (T3) kg WB. Besides, the experimental animals also received a mineral mixture. In 4 weeks, data were recorded on the intake, digestibility, microbial N (MN) yield, N balance (NB) and growth rate (GR). In the three diets, WB was 0 (T1), 29.6 (T2) and 42 (T3) percent of the total DM intake. With the increasing levels of WB supplementation, the total DM and OM intake increased, but the straw intake decreased linearly. WB supplementation increased the digestibilities of DM, OM and N but had no effect on ADF digestibility. The urinary purine derivative excretion and hence the MN yield increased with WB supplementation. The total MN yield were 7.26 and 35 g/d respectively for 0.2 and 3 kg WB supplementation. However, the efficiency of MN yield was highest (13 g/kg DOMR) at 2 kg WB level. Despite the increase DOM intake, the dietary ME content remain below 6 MJ/kg DM even at 3 kg WB supplementation. The NB were -84,467 and 1,620 mg/kg $W^{0.75}/d$ which were reflected on the GR of -186,346 and 554 g/d for 0, 2 and 3 kg WB supplementation respectively. Depending on the cost effectiveness, on an untreated rice straw diet, WB may be supplemented by up to 3 kg/d (42% of the diet) or more. However, if the maximum utilization of roughage is the main concern, the optimum WB level would probably be around 2 kg (30% of the diet) daily.

• Korean Journal of Materials Research
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• v.22 no.9
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• pp.470-475
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• 2012

$La_{1-x}Sr_xMnO_3$(LSM,$0{\leq}x{\leq}0.5$) powders as the air electrode for solid oxide fuel cell were synthesized by a glycine-nitrate combustion process. The powders were then examined by X-ray diffraction(XRD) and scanning electron microscopy (SEM). The as-formed powders were composed of very fine ash particles linked together in chains. X-ray maps of the LSM powders milled for 1.5 h showed that the metallic elements are homogeneously distributed inside each grain and in the different grains. The powder XRD patterns of the LSM with x < 0.3 showed a rhombohedral phase; the phase changes to the cubic phase at higher compositions($x{\geq}0.3$) calcined in air at $1200^{\circ}C$ for 4 h. Also, the SEM micrographs showed that the average grain size decreases as Sr content increases. Composite air electrodes made of 50/50 vol% of the resulting LSM powders and yttria stabilized zirconia(YSZ) powders were prepared by colloidal deposition technique. The electrodes were studied by ac impedance spectroscopy in order to improve the performance of a solid oxide fuel cell(SOFC). Reproducible impedance spectra were confirmed using the improved cell, which consisted of LSM-YSZ/YSZ. The composite electrode of LSM and YSZ was found to yield a lower cathodic resistivity than that of the non-composite one. Also, the addition of YSZ to the $La_{1-x}Sr_xMnO_3$ ($0.1{\leq}x{\leq}0.2$) electrode led to a pronounced, large decrease in the cathodic resistivity of the LSM-YSZ composite electrodes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.2
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• pp.77-84
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• 1988

The effect of chronic ethanol consumption on the concentration of minerals in tissues and serum was studied in growing broiler chicks. Four different groups of the chicks were fed mixtures of 0(control), 1,2 and 3% ethanol and water respectively for 7 weeks. Body weight gain in 1% ethanol group and liver weight in 3% ethanol group were significantly higher than those of control. Mg, K, Mn, and Zn concentrations in liver were higher in ethanol groups than those in control. In ethanol groups, femoral muscle Mg level was increased while its Na concentration was decreased. The concentrations of Ca, Mg and Na in serum were higher in 3% ethanol group than those in control, 1 or 2% ethanol groups. In femur, Zn and Fe levels in 1% ethanol group and Mn concentration in 2 or 3% ethanol groups were increased. But its weight, length, and ash content were not affected by ethanol intake.

• Applied Microscopy
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• v.4 no.1
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• pp.5-10
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• 1974

In this work the effect of pre-rolling on the homogenization and on the mechanical properties of 4.6% Mg-0.5% Mn-0.18% Cr-Al alloy has been studied. At room temperature tensile strength and elongation have been found to increase in the pre- rolled homogenized sample compared to those of the as cast sample. At $400^{\circ}C$ this pre-rolled homogenized sample has shown a little lower tensile strength and a remarkably higher elongation than the samples as casted or homogenized without pre-rolling. Metallurgical microstructure of the pre-rolled homogenized sample has shown conspicuously less secondary phase such as ${\beta}$-phase at the grain boundaries than the other samples. The difference of magnesium content between grain boundaries and within the grains has been also checked by EPMA. The test results show enhanced homogenizing effect by the pre-rolling before homogenizing heat treatment.

• Journal of the Korean Applied Science and Technology
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• v.23 no.1
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• pp.63-69
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• 2006

Methanol and formaldehyde were produced directly by the partial oxidation of methane. The catalysts used were mixed oxides of late-transition metals, such as Mn, Fe, Co, Ni and Cu. The reaction was carried out at $450^{\circ}C$, 50 bar in a fixed-bed differential reactor. The prepared catalysts were characterized by XRD, TPD and BET apparatus. Of the catalysts, A-Mn0.2-6, which contains 0.2 mole of Mn and calcined at $600^{\circ}C$, showed the best catalytic activity: 3.7% methane conversion, and 30 and 28% methanol and formaldehyde selectivities, respectively. The catalytic activity was changed with the content of Mn and the calcination temperature. Catalytic activity increased with the specific surface areas of the catalysts. With XRD, it was found that the structure of the catalysts are changed with calcination temperature. Through $O_2-TPD$ experiment, it was found that the catalysts showing good catalytic activity showed $O_2$ desorption peak around $800^{\circ}C$.

• The Journal of Natural Sciences
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• v.9 no.1
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• pp.39-44
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• 1997

This study was aimed to observe the effects of municipal sewage sludge as nutrients on the growth of Lettuce. The effects of heavy metal components of the sludge were also observed. Municipal sewage sludge from Taejon City were treated to the soil of PaiChai University Farm in order to make gradient of nitrogen concentration in soil among 6 experimental groups. Results are as follows ;The longest leaves and roots were produced in control pot, in which urea was supplied as nitrogen source to the soil. Any other sludge-treated groups produced shorter leaves and roots than control group, but the more sewage sludge treated the longer leaves and heavier vegetables were observed. No differences were observed among from 6 experimental groups in the view of N, K, Ca and Mg contents. But P contents in leaves from 6 groups varied. Zn content of Lettuce when was 65.8 mg/kg when it grew with sludge 200%. The groups treated with sludge 200% produced the vegetables of highest Zn contents. Accumulation of Zn, Mn and Cd was more heavier in Lettuce than in Altari radish. Accumulation of Zn, Mn, Cu and Cd in lettuce was not heavier than natural contents of those in market vegetables.

• Korean Journal of Materials Research
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• v.11 no.1
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• pp.44-47
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• 2001

Effects of $Er_2O_3$ addition on the dielectric properties of non-reducible $BaTi_3$-based X7R dielectrics with Ni electrode have been studied in reducing atmosphere. X7R with moderate temperature-dependence was developed after addition of $Er_2O_3$ with $MnO_2-MgO$; room-temperature dielectric constant and dissipation factor were >2900 and < 1.0%, respectively. The addition of $Er_2O_3$ greater than 3.0 mol% improved the temperature dependence of dielectric properties, but a significant decrease of the dielectric constant at room-temperature was observed. The TCC curves rebated clockwise with increasing MnO$_2$ content at a given additive system, 1.5 mol% $Er_2O_3$ and 2.0 mol% MgO.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.12
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• pp.25-29
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• 1972

This experiment was carried out to investigate the role of Silicon accumlated in rice plant under different conditions of light and humidity, using radioisotopes Ca-45, Mn-54, and P-32. This results obtained in are as follows; 1. Light effect is more severe in phosphate uptake by rice plant than is calcium. Amounts of phosphate uptake in light condition is six times more than in dark conditions, while that of calcium is double. 2. Change of relative humidity affects calcium absorption and transport from root to shoot. It seems not to be influenced in phosphate and manganese uptake by relative humidity. 3. More uptake of each element Ca-45, P-32, or Mn-54 was found in the rice plant applied with silicic acid. It is considered that there must be some relationship between silicon content and ion uptake in rice plant. 4. The transport ratio of nutrient from root to shoot shows a specific pattern that calcium is approximately 1.0 manganese 0.5 and phosphate 0.2 respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.184-189
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• 2008

To assess the relationship between Cd fraction in paddy soils and Cd in polished rice, soils and rice were analyzed at the 3 Cd contaminated paddy fields near closed mines. Major Cd fractions of A field were organically bound (62.6%) and Fe-Mn oxide bound (25.3%) forms. In case of B field, major Cd fractions of B1 field were carbonate bound (46.3%) and Fe-Mn oxide bound (31.6%) form whereas B2 field were residual (54.3%) and carbonate bound (21.8%) form, respectively. It showed a huge difference of Cd fraction each other. 0.1M HCl extractable Cd in soil was positively correlated with Cd in rice. Specially, the ratios of 0.1M HCl extractable Cd against total Cd content in soils were 13.7%, 2.6%, and 0.45% in A, B1, and B2 fields, respectively. These ratio were largely affected with Cd uptake to rice grain. Also, exchangable, Fe-Mn oxide bound, and carbonate bound form, which are partially bioavailable Cd fraction to the plant, were positively correlated with Cd in rice while organically bound and residual form was not correlated. Multiple regression equation was developed with Rice Cd = -0.02861 + 0.07456 FR 1(exchangeable) + 0.00252 FR 2(carbonate bound) + 0.001075 FR 3(Fe Mn oxide bound) - 0.00095 FR 4(organically bound) - 0.00348 FR 5(residual) ($R^2=0.7893^{***}$) considering Cd fraction in soils.