• Applied Chemistry for Engineering
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• v.27 no.4
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• pp.427-432
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• 2016

The purpose of the research was to examine the utilization of waste bittern from salt farm as a source for producing magnesium (Mg). In this work, a precipitation process for recovering Mg, where Mg is precipitated as $Mg(OH)_2$ by the addition of NaOH solution, was investigated. At the NaOH/Mg molar ratios of 2.70 : 1 to 2.75 : 1 and pH 9.5-10, > 99% of Mg could be precipitated from the bittern. The molar concentration of NaOH solution added as an alkaline reagent had no significant influence on the recovery efficiency of Mg precipitate. The particle size of Mg precipitate was strongly affected by the flow rate of caustic addition. The faster the flow rate of caustic addition, the smaller particles were formed. The Mg precipitate recovered was 100-120 g per 1 L of bittern and contained 94% $Mg(OH)_2$ after washing with water. Our results showed that the bittern can be used as a potential resource for Mg production.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.303-308
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• 1992

Three female sheep were daily administered a pyrophosphate analogue, disodium 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) at the level of 4 mg/kg body weight. HEBP largely suppressed bone resorption, which was indicated by the reduction in plasma free hydroxyproline concentration and in calcium mobilization rate during the intravenous infusion of disodium ethylenediaminetetraacetate (EDTA). Contrary to the suppression of bone resorption, plasma total-calcium, magnesium and phosphorus concentrations were not changed by HEBP administration. These results suggest that bone mineral crystals play a meaningless role on calcium, magnesium and phosphorus homeostasis in ruminants if they are fed adequate amounts of these minerals. Plasma magnesium and phosphorus concentrations were not significantly changed after feeding. However, plasma total-calcium was decreased after feeding in both periods and the reduction seemed to be remarkable in the HEBP-treated period. Infusion of EDTA more remarkably reduced plasma ionized calcium concentration in the HEBP-treated that in the untreated period and the recovery of ionized calcium was retarded by HEBP administration. These results suggest that calcium release from bone is necessary for maintenance of plasma calcium when animals rapidly lose calcium.

• Journal of Korea Foundry Society
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• v.9 no.5
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• pp.389-395
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• 1989

The effects of phosphorus and boron additions and isothermal holding time on the residual magnesium and sulfur content, and on the resultant graphite structure of cast irons were investigated. The effective recovery ratio of magnesium showed that adding phosphorus to the melt retarded the fading rate of magnesium but adding boron accelerated it. However, the residual sulfur content was found to be decreased with isothermal holding time at the begining, and then to be increased again with holding time by resulfurization. The Mg-Equivalent for producing compacted vermicular graphite structure was found to be increased with the addition of phosphorus, whereas to be decreased with the addition of boron.

• Journal of Chest Surgery
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• v.30 no.1
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• pp.11-16
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• 1997

The Increasing use of coronary perfusates for the protection of the human heart during ischemic cardiac arrest has placed great emphasis on the need for a rational and safe formulation. For the purpose of this study isolated rat hearts were connected to retrograde nonworking perfusion system proposed by Langendorff, and then perfused for 20 minutes by coronary infusates of magnesium concentration of 1.66 m Mol per liter(group A, n: 10) or 15mMo1 per liter(group B, n: 10). After 20 minutes perfusion, cold cardioplegic solution (modified St. Thomas'Hospital solution) was infused for 2 minutes, and prepared within 4$^{\circ}C$ Krebs-Henseleit solution. Finally, 20 minutes of cononay reprsfuslon was reestablished after I hour of cold ischemic cardiac arrest. Hemodynamic parameters (heart rate, left ventricular pressure, $\pm$ dp/dt max. and coronany flow) and enzymes assay (creatine phosphokinase, lactic dehydrogenase and flutamic oxaloacetic transaminase) were performed each other at whic rat heart was perfused for 20 minutes and reperfused for 20 minutes thereafter. There were significant differences in the recovery rate of heart rate, systolic left ventricular pressure, + dp/dt max, and coronary flow and reperfusion-perfusion ratio of creatine phosphokinase(P < 0.05). But, there were no signicant differences in the recovery rate of dp/dt max, and reperfunion-perfusion ratio of lactic dehydrogenase and glutamic oxaloacetic acid (P > 0.05).

• Journal of Nutrition and Health
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• v.14 no.4
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• pp.151-161
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• 1981

The objective of this study was to compare the electrolytes contents in skeletal muscles of two different groups of rats, one for control fed 20% casein diet, and the other experimental group recovered from 7% casein diet as protein restriction feeding for two weeks at the beginning of this experiment. Two different comparison criteria were used in this study, one for comparison between animals at the same age groups and the other between groups weighing same body weight as the control groups. Food consumption of animals for experimental and control groups were ad libitum. Following measurement and samples were collected: body weight, five different muscles-anterior tibialis (A.T.) extensor digitorium longus (E.D.L.) soleus, plantaris, gastrocnemius-for electrolytes and protein analysis. The experimental groups showed lower body weight than that of control group. Same trend was showen in protein content in five different muscles. Magnesium and potassium content in four muscles except gastrocnemius showed lower and sodium higher in experimental groups than those in control group at fourteenth day, after recovery from protein restriction, electrolytes content change showed differently in four muscles. Magnesium and potassium contents were increased as protein content in diet. Sodium content decreased as one week intake of recovery diet started, thereafter it was rather slowly increased. Phosphorus content in gastrocnemius at the second week in experimental group was slightly lower than that of control group, and it recovered rapider while at the same body weight group it was higher in experimental group.

• Animal Bioscience
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• v.34 no.4
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• pp.539-545
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• 2021

Objective: Endometritis is a major disease, that causes infertility in cattle, and is usually categorized as clinical or subclinical endometritis (SCE). The nutritional condition during the dry period is important for recovery after the last stage of the lactation period, and for postpartum production and reproduction. This study aimed to clarify the relationship between nutritional and metabolic characteristics in the dry period, and the risk of postpartum SCE. Methods: Multiparous Holstein dairy cows (n = 25, raised in a tied stall) were used. Endometrial cytological analysis was performed around 30 days post-partum, with 5% to 14% polymorphonuclear (PMN) as a cut-off point to define SCE. Serum levels of glucose, non-esterified fatty acids, β-hydroxybutyric acid (BHBA), blood urea nitrogen, total cholesterol, aspartate aminotransferase, γ-glutamyl transpeptidase, calcium, phosphorus, and magnesium were measured in the cows at the dry period to evaluate energy status, protein metabolism, and mineral metabolism. Results: The incidence of SCE in the cows was 60.0% (n = 15/25) and the mean PMN% in postpartum cows diagnosed as SCE was 8.05%±2.6%. Overall, 17 and 8 samples were collected from the cows in the far-off and close-up periods, respectively. The serum concentration of BHBA in the far-off period and serum glucose concentration in the closeup period were correlated with postpartum PMN% (r = 0.62, p<0.01; r = -0.74, p<0.05, respectively). Serum levels of calcium and magnesium in the dry period were associated with the incidence of postpartum SCE (healthy vs SCE cows, p<0.05). Conclusion: Blood levels of glucose, BHBA, calcium, and magnesium in dry periods could be useful parameters for predicting the risk of postpartum SCE. The present study also suggests that management in the close-up period is essential for promoting recovery from calving fatigue.

• Resources Recycling
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• v.25 no.3
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• pp.63-73
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• 2016

With the purpose of concentrating the magnesium from seawater, in this study, we have conducted experiments to precipitate the magnesium using three precipitants (NaOH, cement kiln dust, and paper sludge ash), and then extract it using sulfuric acid. Results show that the precipitation and extraction performance does not depend so significantly on the kind of precipitant: for all the precipitants used, the precipitation efficiency is measured almost 100% and the extraction efficiency is in the short range of 77 - 89%. The magnesium concentration in the extract is measured 4975 - 5775 mg/L, implying that the magnesium in seawater should be 3.8 - 4.4 times concentrated through the precipitation and extraction reactions. The reaction efficiency of the industrial by-product used as a precipitant in this study is almost 100% similar to those of the other existing expensive precipitants.

• Transactions of Materials Processing
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• v.27 no.3
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• pp.177-183
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• 2018

The influence of electric current on the springback characteristics of AZX311 magnesium alloy and martensitic steel after V-bending test is investigated. Various pulsed electric currents are applied into the specimens followed by a V-bending test, and the changes in the springback angle are measured. In order to evaluate not only the thermal effect but also the athermal effect of electric current on the springback angle, the temperature rises resulting from the applied electric current are measured for all test conditions. As a result, it was found that the springback is significantly decreased as the current density increases. As for the martensitic steel, since the dislocation recovery immoderately occurs at a high electric current density condition of $80A/mm^2$, the optimal current density condition should be required.

• Resources Recycling
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• v.23 no.3
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• pp.21-29
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• 2014

This study was conducted to obtain the basic data for designing the lithium recovery process from the "salar de Uyuni" in Bolivia. For this study, the mock brine which has the similar chemical composition with the brine of "salar de Uyuni" was prepared, and the effects of reaction factors such as temperature, time, pH and so forth on the precitation reaction of magnesium hydroxide were investigated.

• Bulletin of the Korean Chemical Society
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• v.13 no.5
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• pp.517-520
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• 1992

Solvent exchange rates of selected protons were measured by NMR saturation recovery method for yeast $tRNA^{Phe}$, at temperature from 25 to $40^{\circ}C$, in the presence of 0.1 M NaCl and various low levels of added magnesium ion. The exchange rates in zero $Mg^{2+}$ concentration indicate early melting of acceptor stem, D stem, and tertiary structure. Addition of magnesium ion stabilizes the entire D stem more effectively than any other secondary or tertiary interactions.