• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.7 no.2
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• pp.181-195
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• 1997

The purpose of this study was to investigate factors affecting the composition and concentrations of fumes generated from various types of welding processes. The results are as follows. 1. Iron(Fe), zinc(Zn) and manganese(Mn) were predominant in Welding fumes. The Fe content in total fumes was 25.5% in coated electrode and 28.2% in $CO_2$ are welding, and the Zn content was 4.5% and 9.1%, respectively, and the Mn was 3.6% and 7.8%, respectively. 2. It was found that the important factors determining composition and concentration of fumes were type of industries, type of welding processes, type and composition of electrodes, composition of base metals, confinement of workplaces or condition of ventilation, work intensity, coated metals such as lead and Zn in paint. 3. The Mn content in airborne fumes was highly correlated with that of electrode(r=0.77, p<0.01) and was about 4 times higher than that in electrodes or base metals. The results lindicate that Mn is well evaporated into air during welding. The higher vapor pressure of Mn may explain this phenomenon. 4. the airborne total fume concentrations were significantly different among types of industries(p<0.001). The airborne total fume concentration was higher in order of sleel-structure manufacturing($GM=15.1mg/m^3$), shipbuilding($GM=13.2mg/m^3$), automobile-component manufacturing ($GM=7.8mg/m^3$) and automobile assembling industry($GM=3.0mg/m^3$) 5. The airbone total fume concentration was 6 times higher in $CO_2$ welding than in coated electrode welding, and approximately 3 times higher in confined area than in open area, in steel-structure manufacturing industry. 6. The concentration of welding fume outside welding helmet was about 2 times higher than that inside it. It is recommened that air sampling be done inside helmet to evaulate worker's exposure accurately, for it has an outstanding effect on reducing worker exposure to fumes and other contaminants.

• Journal of Sericultural and Entomological Science
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• v.29 no.1
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• pp.1-6
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• 1987

Changes in water content, dry weight, total nitrogen (T-N), P, K, Ca, Mg, B, Fe, Cu, Zn and Mn and death rate were studied in winter buds of mulberry trees. Winter buds of the early season varieties, Hongolbbong and Chongolbbong, (Morus Lhou Koioz) and midseason varieties, Kaeryangbbong and Chongilbbong, (Morus alba L.) were sampled every 7 days from February 28 to April 28, 1986. The result were as follow : 1. Water content was increased by 20% over the level of 45% in late February. The water content in Chongolbbing was the highest, whereas that in the rest of the varieties was nearly equal. 2. Dry weights of winter buds of the early varieties were always greater than those of midseason varieties. The dry weight of buds of early season varieties began to increase in late February and increased rapidly after April 18. There was no weight gain until April 12 in buds of midseason varieties, followed by a slow increase thereafter. 3. T-N and P, K, B, Fe, Cu and Zn concentration increased with time, Mn decreased, and Ca and Mg levels were constant. 4. T-N and Mn levels were higher and P, Ca, Fe and Cu lower in Hongolbbong than in the other varieties. T-N, Mg and Cu levels were lower in Chongolbbong. 5. The death rate of winter buds increased with the approach of the budding season. The rate was highest in Chongolbbong and lowest in Hongolbbong.

• Korean Journal of Materials Research
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• v.26 no.9
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• pp.504-511
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• 2016

To prepare $Mn^{4+}$-activated $K_2TiF_6$ phosphor, a precipitation method without using hydrofluoric acid (HF) was designed. In the synthetic reaction, to prevent the decomposition of $K_2MnF_6$, which is used as a source of $Mn^{4+}$ activator, $NH_5F_2$ solution was adopted in place of the HF solution. Single phase $K_2TiF_6$:$Mn^{4+}$ phosphors were successfully synthesized through the designed reaction at room temperature. To acquire high luminance of the phosphor, the reaction conditions such as the type and concentration of the reactants were optimized. Also, the optimum content of $Mn^{4+}$ activator was evaluator based on the emission intensity. Photoluminescence properties such as excitation and emission spectrum, decay curve, and temperature dependence of PL intensity were investigated. In order to examine the applicability of this material to a white LED, the electroluminescence property of a pc-WLED fabricated by combining the $K_2TiF_6$:$Mn^{4+}$ phosphor with a 450 nm blue-LED chip was measured.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1804-1808
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• 2003

A layer experiment was conducted to determine the effects of supplementary methionine chelates (Cu, Zn and Mn), individual or in combination, on laying performance, eggshell quality, gizzard erosion, and IgG level of serum for 8 weeks. Five hundred 96-wk-old force molted ISA Brown layers were assigned to five dietary treatments. Basal diet was formulated to meet or exceed the nutrients requirements listed in NRC (1994). Five experimental diets were control, Zn-methionine chelate (Zn-Met) supplemented, Cumethionine chelate (Cu-Met) supplemented, Zn-Mn-methionine chelate (Zn-Mn-Met) supplemented and Zn-Mn-Cu-Met supplemented diet. Each treated diet was supplemented with respective mineral(s) at the level of 100 ppm in the form of methionine chelate. Egg production was increased by Cu-Met supplementation but decreased by Zn-Met supplementation. Egg weight was significantly (p<0.05) lower in Cu-Met treatment than those of the control and Zn-Met treatment. Specific gravity of eggs and eggshell strength were highest and soft egg production was lowest in Cu-Met treatment. Gizzard erosion index was significantly increased by supplementation of Cu-Met, Zn-Mn-Met or Zn-Mn-Cu-Met. Zinc content in liver significantly increased by Zn-Met, but not by Zn-Mn-Cu-Met treatment. In conclusion, 100 ppm Cu in Cu-Met chelate improved laying performance and eggshell quality but also increased gizzard erosion index. Supplementation of Zn-Met or its combination with other mineral chelates had no beneficial effects on laying performance and eggshell quality.

• Journal of the Korean Ceramic Society
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• v.40 no.7
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• pp.637-643
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• 2003

In order to improve the photoluminescent properties and crystallinity, Zn$_2$SiO$_4$:Mn, M(M=Cr, Ti) phosphors were synthesized by the sol-gel method. The willemite single phase was obtained at 110$0^{\circ}C$, which is lower temperature than that of the conventional solid-state reaction (130$0^{\circ}C$). The characteristics of fired samples were obtained by a 147 nm excitation source under VUV (Vacuum Ultraviolet). To investigation the effect of co-dopant, the content of Mn and the ratio of $H_2O$ to TEOS was fixed as 2 ㏖% and 36. 1, respectively. The highest emission intensity was obtained when the concentration of Cr and Ti was 0.1 ㏖% relative to Zn$_2$SiO$_4$:Mn. While the emission intensity decrease continuously the decay time improved as increased the Cr concentration. In the case of Ti added samples, however, the emission intensity increase up to 2 ㏖％ concentration.

• Korean Journal of Materials Research
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• v.13 no.12
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• pp.839-845
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• 2003

The abrasion and impact wear resistance were investigated on the hardfacing weld dispersed with the recycled hard metal(HM). The HM was composed of the tungsten carbide(WC) reinforced metal matrix composite. The cored wire filled with the 25-35wt.% HM and 2-8wt.% of the alloying element, Fe-75Mn- 7C(FeMnC), was used for the gas metal arc(GMA) welding. By using the cored wire of the 25wt.% HM and FeMnC addition, the weld showed mostly constant wear loss for the abrasion as a function of the FeMnC content. This was due to the insufficient amount of the tungsten carbide formed during the GMA welding. The FeMnC addition to the 35wt.% HM did not improve the abrasion wear property since the amount of the tungsten carbide formed was decreased with respect to the FeMnC amount. The 6wt.% FeMnC addition to the 35wt.% HM exhibited the better impact wear resistance than the hardfacing weld by 40wt.% HM.

• Analytical Science and Technology
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• v.5 no.3
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• pp.327-332
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• 1992

Mn-Zn ferrite single crystals show some fluctuations in composition along the direction of growth by the conventional Bridgman method. The single crystal with a uniform composition was obtained by maintaining the liquid composition content. For example, two batches of powder were prepared : one is consisted of 52 mol% of $Fe_2O_3$, 30 mol% of MnO, and 18 mol% Zn(Composition A), and the other 53 mol% of $Fe_2O_3$, 28.5 mol% of MnO, and 18.5 mol% ZnO(Composition B). Crack-free single crystals with the uniform composition B were grown in a size of 60mm diameter, 300mm long by melting the pellets of composition A and followed by supplying the composition B as tablets. Initial permeabilities were obtained above 600 at 5 MHz in the region of 30~270 mm along the direction of growth.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.1
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• pp.125-129
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• 1994

A field survey was carried out in Korea to assess the mineral composition of rice straw since it is a cheap and available cattle feedstuff. Forage and soil samples were collected in 4 localities in the Kyongbuk province. Soil analysis were also carried out in order to establish the relationships between soil composition and mineral content in the rice straw. Based on NRC tables, the rice straw samples provided adequate amounts of Mg, Ca, K, S, Mo, Mn and Zn. Percentages of samples deficient in P, Na, Cu and Se were 83, 50, 67 and 83 respectively. Soil samples, whose mean pH was 5.8 and mean organic matter content was 3.99%, were comparatively acidic and had high organic matter content. They also had high amounts of extractable Fe and Mn. Correlation coefficients between mineral content in soil and rice straw were low, i.e., 0.42 for Me (p < 0.05), and 0.37 for Mo (p < 0.05). The low or nonexistent correlation between soil and forage composition indicates the difficulty of establishing appropriate methods of mineral availability to the plants.

• The Korean Journal of Food And Nutrition
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• v.31 no.2
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• pp.313-317
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• 2018

This study investigated the nutritional composition of green pepper (Capsicum annuum L. cv. DangZo). Specifically vitamin C, minerals and amino acids content in green peppe were measured. The crude ash, crude protein, and crude fat contents of green pepper were found to be 0.64, 2.10 and 1.20 g/100 g, respectively. The ascorbic acid content in green pepper was 99.34 mg/100 g. The K content was found to be the highest with regard to mineral. This was followed by P, Mg, Na, Ca, Zn, Cu, Mn which means green pepper is an alkali material. The K, P, Mg, Na, Ca, Zn, Cu, Mn contents of green pepper found to be 980, 68.33, 60, 34.14, 30.88, 5.87, 5.25 and 3.07 mg/100 g respectively. The total amino acid content ranged from 7.0 to 1,625.3 mg/100 g, respectively. With regard to amino acid contents, arginine and citrulline were found to be abundant. From the results, green pepper could be suggested as beneficial for food processing.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.976-982
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• 2007

This study investigated whether supplemental Cu, Fe, Zn, and Mn are needed in a practical diet for pullets. Four hundred and twenty females of an egg-laying strain (1-d-old, Lohmann Brown Layer) were randomly distributed into 4 groups, consisting of 7 replicates of 15 birds each. During the 18-week experimental period, chicks were given three basal diets in sequence, each with single or multiple Mn, Zn and Cu supplementation to improve the mineral balance gradually. In the Control, no Mn, Zn, and Cu were added; in the single Mn supplemented group (sMn) Mn was added to 120, 60, and 60 mg/kg for 1-6, 7-12, and 13-18 weeks of age, respectively; in the multiple Mn and Zn supplemented group (mMnZn), Mn was added to 180, 90, and 90 mg/kg and Zn was added to 120, 105, and 105 mg/kg for 1-6, 7-12, and 13-18 weeks of age, respectively; in the multiple Mn, Zn, Cu supplemented group (mMnZnCu), Mn, Zn, and Cu were added to the same multiple of basal Fe concentration relative to NRC (1994) recommendations. Energy and protein metabolizability were determined by subtracting energy/protein intake by energy/protein excretion (from both feces and urine) and dividing by energy/protein intake. There were no statistically significant differences between groups in terms of feed intake, final body weight or tibia length throughout the experiment. Optimal growth performance was observed in the Control, while adding trace minerals to basal diets tended to result in decreased productive performance. Protein metabolizability was increased by mMnZn and mMnZnCu treatments, but energy metabolizability was not affected. Concentrations of Mn, Zn, Cu in excreta varied greatly related to dietary content, and the retentions of Cu, Fe, Zn and Mn were all increased due to the improvement of mineral balance. Based on these results, it is suggested that the concentrations of Cu, Fe, Zn and Mn in typical basal diets used in this study were adequate for normal growth for pullets from 1 to 18 weeks of age.