• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.1
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• pp.6-11
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• 2023

Objective: This study was conducted to identify the cause of suffocation accident. Methods: We analyzed the components of zinc concentrates by ICP-OES (inductively coupled plasma optical emission spectroscopy) and tested the oxygen consumption by zinc concentrates in a 13.2-liter closed chamber. Results: Zinc, sulfur and iron were the main components of the four types of zinc concentrates, and accounted for 76~89% by weight. Zinc concentrates (0.5 or 0.927 kg) depleted the oxygen concentration from 20.9% to 7.4~18.9% during seven days. The rate of oxygen consumption was in the range of 3.0~11.0 mM/day·kg-sample at 21~24℃ and around 95% of free air space within the closed chamber. Conclusion: Since zinc concentrate consumes oxygen in a confined space, measures should be taken to prevent suffocation accident (such as ventilation and monitoring of oxygen concentration).

• Journal of Nutrition and Health
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• v.28 no.5
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• pp.387-396
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• 1995

This study was undertaken to investigate the effect of increase in the ratio of zinc to copper and alcohol consumption on serum lipid content in Sprague-Dawley male rats during five weeks. Sixty rats were divided into six groups, CZ < zinc 30ppm diet >, CZA < zinc 30 ppm diet plus alcohol 5% solution >, HZ < zinc 300ppm diet >, HZA < zinc 300ppm diet plus alcohol 5% solution >, SHZ < zinc 600ppm diet >, SHZA < zinc 600 ppm diet plus alcohol 5% solution >. High ratio of zinc to copper groups < HZ, SHZ > were significantly decreased in high-density lipoprotein (p<0.01) and increased in total cholesterol, triglyceride, total lipid in serum(p<0.001, p<0.001, p<0.01). Triglyceride levels of serum in alcohol groups < CZA, HZA, SHZA > were significantly higher (p<0.001) than non-alcohol group < CCZ, HZ, SHZ >. Copper levels of serum were reduced in group high ratio of zinc to copper. These results present that high ratio of zinc to copper increase cholesterol(p<0.001) and alcohol consumption increase triglyceride(p<0.001) in serum. This close association to lipid metabolism in rats draw attention to the potential significance of zinc and alcohol nutriture in relation to cardiovascular disease.

• Journal of the Korean institute of surface engineering
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• v.36 no.1
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• pp.42-47
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• 2003

Hot-dip galvanizing process is used widely in industry to achieve corrosion resistant coatings. Poor drainage during this process often leads to problems such as icicle formation and bridging In this work, mild steel specimens were hot-dip galvanized. Influence of the addition of bismuth, aluminum and both (bismuth and aluminum) to the zinc bath on the zinc drainage were determined. Bismuth additions improved the drainage significantly. Zinc bath containing 0.1 wt.% Bi and 0.025∼0.05 wt.% Al showed uniformity of coatings. Industrial trials with this bath composition showed reduction in zinc consumption, reduction of ash and dross, and good luster of workpiece.

• Asian-Australasian Journal of Animal Sciences
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• v.3 no.1
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• pp.53-59
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• 1990

A study was conducted to investigate the release pattern of zinc form the zinc containing boluses and to see whether the released zinc can cure a zinc deficiency in sheep. Three sheep were used in this experiment and were fed a low zinc semi-synthetic diet throughout the experimental period. Each sheep was given a single pre-weighed zinc containing bolus when blood variables showed continuous zinc deficiency. The zinc containing boluses when placed within the reticulo-rumen of zinc deficient sheep, release zinc at the rate of 106.6 mg zinc/day for 39 days. At the end of depletion period there was a reduced feed consumption, plasma zinc concentration, plasma alkaline phosphatase activity and increased plasma zinc binding capacity which were 409 g, 0.18 mg/l, 87 U/l and 88.7% respectively and 521 g, 0.18 mg/l, 142 U/l, and 89.5% respectively before first and second blousing. After the administration of the first and second boluses, the feed consumption, plasma zinc levels and plasma alkaline phosphatase activities rose rapidly and far exceeded the starting values. The zinc binding capacity was reduced to 21.9% due to the administration of the first and second boluses. It is concluded that zinc boluses can be used for curing a zinc deficiency in sheep.

• Corrosion Science and Technology
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• v.10 no.2
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• pp.43-46
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• 2011

Zinc consumption in a continuous galvanizing line is one of the highest operating cost items in the facility and minimizing zinc waste is a key economic objective for any operation. One of the primary sources of excessive loss of zinc is through the formation of top dross and skimmings in the coating pot. It has been reported that the top skimmings, manually removed from the bath, typically consist of more than 80% metallic zinc with the remainder being entrained dross particles ($Fe_2Al_5$) along with some oxides. Depending on the drossing practices and bath management, the composition of the removed top skimmings may contain up to 2 wt% aluminum and 1 wt% iron. On-going research efforts have been aimed at in-house recovery of the metallic zinc from the discarded top skimmings prior to selling to zinc recycling brokers. However, attempting to recover the zinc entrapped in the skimmings is difficult due to the complex nature of the intermetallic dross particles and the quality and volume of the recycled zinc is highly susceptible to fluctuations in processing parameters. As such, an efficient method to extract metallic zinc from top skimmings has been optimized through the use of a specialized thermo-mechanical process enabling a continuous galvanizing facility to conserve zinc usage on-site. Also, through this work, it has been identified that filtration of discrete dross particles has been proven effective at maintaining the cleanliness of the zinc. Future efforts may progress towards expanded utilization of filters in continuous galvanizing.

• Journal of Plant Biology
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• v.20 no.3
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• pp.119-126
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• 1977

The maximum relative growth rate of algae treated with Zinc was shown as follows: 15, 8, 6, 3 and -5% per day for the rather sensitive Chlorella sp. populations, or 14, 7, 5 and 4% per day for the Pleurococcus sp. populations, and 22, 20, 13, 9 and 7% per day for the more resistant Scenedesmus spinosus populations, respectively for the culture medium with 0, 1, 5, 10 and 20 ppm of Zinc treatment. With mixed cultures of Chlorella sp. and Scenedesmus spinosus populations, the growth of the Chlorella sp. population overcame that of the S. spinomsus population from the cultures treated with relatively low concentration of Zinc. On the contrary, the population growth of the latter resistant species overcame that of the former sensitive species when the concentration of Zinc was above 5 ppm Zn of the medium. This paper describes the results of further investigations of the effects evaluated by direct cell counts method, optical density comparisons, oxygen production and consumption determinations and the measurements of the fate of Zinc treated in the solutions.

• Journal of Nutrition and Health
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• v.22 no.6
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• pp.539-546
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• 1989

This study was carried out to investigate the effect of addition of cellulose in the diet on the metabolism in rat fed high and low level of zinc. The experimental animals were consisted of 24 male weaning rats of Sprague-Dawley strain(mean weight 72.3g), and they were devided into 4 groups of 6 rats and fed experimental diets for four weeks. Dietary zinc levels used were 10 ppm, and 300ppm and cellulose levels were 2.5% and 10% of diet by weight. Throughout the experimental period, feed consumption and body weight gain were measured and feed efficiency ratio was calculated. The weight of live, kidney and spleen were measured, and the contents of zinc in feces, urine, liver, kidney, spleen and serum were determined. The results obtained are summarized as following ; 1. Body weight gain in high zinc-adequate cellulose group was significantly higher than the other groups. Feed consumptions were significantly higher in high zinc groups and no significant difference was found with dietary cellulose levels. 2. Fecal zinc excretions of four groups were not different at the first week, but at the end of fourth week, high zinc groups experince significantly more zinc excretion than low zinc groups, and also high cellulose groups had higher zinc contents in the feces than the adequate ones within the same zinc levels(p<0.05). There was no significant difference in the urinary zinc excretion. 3. The weights of liver, kidney and spleen were heavier in the high zinc groups than the lower ones, and higher in the high cellulose groups(p<0.05). The liver zinc contents were significantly lower in the low zinc and high cellulose groups. However zinc contents in the kidney and serum were not influenced by dietary zinc level but by cellulouse level. High cellulose diet lowered serum and kidney zinc concentrations(p<0.05).

• Preventive Nutrition and Food Science
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• v.9 no.1
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• pp.79-84
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• 2004

Zinc intake and status of South Koreans from rural, urban and metropolitan areas were investigated. The dietary habits of 760 healthy male and female adult subjects with a mean age of 54 were assessed using a food frequency questionnaire and were verified using 24 h dietary recall. Daily Zn intakes for men and women were 7.4$\pm$5.4 mg and 7.0$\pm$5.4 mg, respectively, which were 62% and 70% of the Korean RDA. The phytate : zinc and phytate ${\times}$ calcium : zinc molar ratios were 38 and 398, respectively. Both the low intake of zinc and the high extremely phytate and phytate ${\times}$ calcium ratios with Zinc suggest that South Koreans may be at risk of zinc deficiency. Plasma zinc (86$\pm$61 $\mu\textrm{g}$/dL), urinary zinc (33$\pm$27 $\mu\textrm{g}$/dL) and plasma alkaline phosphatase (102$\pm$52 mU/mL) levels within the normal range did not however suggest marked Zinc deficiency in these subjects. However, conventional zinc biomarkers aye known to be unreliable for assessment of marginal zinc deficiency. Based on zinc intake alone, it is likely that at least a proportion of these subjects were marginally zinc deficient and the wider consumption of zinc rich, phytate deficient foods, particularly in rural areas, would be beneficial.

• The Korean Journal of Community Living Science
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• v.16 no.4
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• pp.25-38
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• 2005

In order to investigate the effect of dietary zinc and phytic acid levels on enzyme activity and lipid metabolism in rats, male Sprague-Dawley rats, weighing approximately 60-74g, were fed different diets which contained 0, 0.35 or $1.05\%$ phytic acid each at 3 levels of zinc (0, 30 and 1500ppm zinc) for 28 days. Body weight gain, food consumption, and food efficiency ratio were lower in the rats fed a zinc deficient diet (0ppm zinc) than those consuming 30 or 1500ppm dietary zinc. The activities of GOT, GPT and alkaline phosphatase were lower in the rats consuming 30ppm zinc than those fed 0 or 1500ppm zinc diet. The activity of GOT was increased in rats consuming $0.35\%$ phytic acid, whereas that of alkaline phosphatase was decreased in the rats fed phytic acid-containing diet. The concentration of phospholipid in serum was higher in rats fed $0.35\%$ dietary phytic acid, whereas that of liver phospholipid was higher in zinc deficient groups, and increased by addition of dietary phytic acid. The concentration of triglyceride in serum from rats fed 30ppm zinc was lower than those fed 0 or 1500ppm zinc On the other hand, liver triglyceride was higher in both the rats fed 30ppm zinc and $0.35\%$ phytic acid. The concentration of serum total cholesterol was lower in the rats fed 30ppm zinc diet, and it was increased by addition of dietary phytic acid. But liver total cholesterol was higher in 30ppm zinc group. HDL-cholesterol in serum was the highest in both rats consuming 30ppm zinc and $0.35\%$ dietary phytic acid, and the ratio of HDL-cholesterol to total cholesterol was higher in rats consuming 30ppm zinc diet. In conclusion, we suggest that coronary heart disease or liver disease can be prevented with phytic acid in rats which are fed the high zinc diet.

• Economic and Environmental Geology
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• v.3 no.3
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• pp.141-161
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• 1970

The outline of general trend on production, consumption and price of non-ferrous metals during 1969 is summerized in the paper. The production of every non-ferrous metals has increased compare to that of last year, and their consumption except silver has also increased. Specially the rate of growth of production is that; The rate of growth of consumption is such; The prices of gold and silver have decreased since last November due to the stability of international currency and the creation of S.D.R. at I.M.F., but those of other metals have increased, marking the price at the end of 1969 as follows: Cupper price of Foreign Refinery showed ¢72.471/lb(increased 39% per year), lead and Zinc jumped up to the highest price since the Korean War (1951-1953), showing the lead price ¢16.50/lb (increased 27% per year) and the zinc price ¢15.50/lb (increased 15% per year). Price of tungsten was higher than the agreed price that was made between Korea and U.S.A. during 1951 through 1954, showing $63.4/S.T.U. (increased 13% per year). The price of molybdenum was slightly increased from $1.62 to $1.72 (increased 6% per year). In summing up, the year of 1969 was the golden age for the nonferrous metals. It is, hawever, expected that in the next few years, the consumption rate and the prices of non-ferrous metals will be declined compared to those of 1969.