• Journal of Hydrogen and New Energy
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• v.10 no.1
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• pp.9-17
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• 1999

The hydriding and dehydriding kinetics were studied for a Mg-25wt.%Ni mixture which has the most excellent hydrogen-storage characteristics among many mechanically-alloyed mixtures. The hydriding and dehydriding rates were measured and the rate-controlling steps were determined by comparing the hydriding and dehydriding rates with the theoretical rate equations. The rate-controlling step in the hydriding reaction is the Knudsen flow and the ordinary gaseous diffusion of hydrogen molecules through interparticle channels, cracks, etc. in the various ranges of weight percentage of absorbed hydrogen $H_a$ below $H_a$=4.0. In the $H_a$ range 4.0 < $H_a{\leq}4.25$, the diffusion of hydrogen atoms through the growing hydride layer is considered the rate-controlling step. The rate-controlling step in the dehydriding reaction is the Knudsen flow and the ordinary gaseous diffusion of hydrogen molecules for all the ranges of weight percentage of desorbed hydrogen $H_d$.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.1
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• pp.33-39
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• 2022

Batch experiments were conducted to find out the effects of various types of magnesium compounds on phosphorus recovery by magnesium ammonium phosphate (MAP) crystallization. The phosphorus recovery from the centrate of anaerobic digested sludge was performed using magnesium chloride, magnesium hydroxide and magnesium oxide under different pH (7.5, 8.0 and 8.5) and Mg/P molar ratio (1.0, 1.5, 2.0, 2.5) conditions. The phosphorus recovery rate increased with increasing pH and Mg/P molar ratio in all magnesium compounds. At pH 7.5, magnesium oxide showed the highest phosphorus recovery rate, followed by magnesium hydroxide and magnesium chloride. However, at pH 8.5, more than 90% of phosphorus recovery rate was obtained in all Mg/p molar ratios. Thus, it is expected that magnesium hydroxide and magnesium oxide are able to replace magnesium chloride as a magnesium source in terms of phosphorus recovery efficiency and cost.

• Journal of the Korean Ceramic Society
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• v.50 no.3
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• pp.201-205
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• 2013

Magnesium hydroxide sulfate hydrate ($5Mg(OH)_2.MgSO_4{\cdot}3H_2O$, abbreviated 513 MHSH) whiskers were synthesized using MgO and $MgSO_4.7H_2O$ as reactants without addition of basic solution. Previously, MHSH whiskers were prepared by hydrothermal method using $MgSO_4$ in aqueous ammonia. In this work, for the first time, we synthesized a high purity MHSH via ambient pressure. In addition, a high molar ratio of $MgSO_4$ : MgO is an important key to the formation of high purity MHSH. Also, it was possible to prepare whiskers with high aspect ratio using an increasing reaction time in the reaction between the remaining $SO_4^{2-}$ ions and the ${Mg(OH)_6}^{4-}$ fragment, finally producing one-dimensional whiskers.

• Journal of Hydrogen and New Energy
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• v.6 no.2
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• pp.91-100
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• 1995

To investigate the surface state of $Mg_2Ni$ which was exposed to the air, a chemical treatment was undertaken with $H_2SO_4$ solution. During chemical treatment, the change of pH was measured continuously and the chemically treated specimen was hydrided to study the effect of chemical treatment on the hydrogenation. The pH changing behavior with the various $H_2SO_4$ concentration appeared very diffemrently. Especially in the solution including 3CC $H_2SO_4$, the behavior of pH change can be divided 3 steps. It is also shown that the $Mg_2Ni$ chemically treated with $H_2SO_4$ can be hydrided even under room temperature. By the SEM observation the was reasion that after chemical treatment the surface of a particle was covered with Ni layer.

• Microbiology and Biotechnology Letters
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• v.18 no.1
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• pp.61-65
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• 1990

Lectin related inducer can enhance IgG$_1$ production rate from murine hybridoma cells by employing step-feeding of serum free media with producing about 40 mg/$\ell$ of monoclonal antibodies. This step-feeding perfusion process also proves to be able to cutivate animal cells when serum free media can not support the growth of these cells in perfusion process, as well as to improve production rate. This process yields about 28 x 10$^{-10}$ mg of MAb/cells/h compared to 11.1 x 10$^{-10}$ and 4.0 x 10$^{-11}$ mg/cells/h for perfusion process and batch cultivation with 10% serum containing media, respectively.

• Korean Journal of Plant Tissue Culture
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• v.21 no.4
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• pp.227-231
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• 1994

The experiments were conducted to obtain culture conditions on optimal cultural conditions for propagation of a topical orchid, Haemaria discolor, through shoot tip cultrue in vitro. Survival percentage of shoot tip explant, in initial culture media was higher in H$_3$P$_4$ medium than in Murashige and Skoog's medium. Explants, cultured in H$_3$P$_4$ medium containing 1.0 mg/L kinetin, showed more shoot elongation when compared with those on other media. When the distal part of stem (pseudobulb) was longitudinally sectioned into half and cultured in H3P4 medium containing 0.1 mg/L 2ip, 0.1, or 1.0 mg/L kinetin, shoots from axillary bud were much more elongated under light condition.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.11 no.1
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• pp.27-32
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• 2001

The 0.9PMN-0.1PT powders was prepared by the sol-gel process, and the effect amounts of ${Mg(OC_{2}H_{5})}_2$ and ${Pb(CH_{3}COO)}_2.3H_{2}O$ as starting materials was studied. As a result the percent of perovskite phase of the calcined powders increased with increased calcination temperatures. Maximum of perovskite phase was at $850^{\circ}C$ for 4 hrs. 0.9PMN-0.1PT powder by addition of 5 wt% excess ${Mg(OC_{2}H_{5})}_2$ crystallized to perovskite phase with a ${\fallingdotseq}100%$ yield.

• Journal of the Korean Ceramic Society
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• v.33 no.3
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• pp.307-312
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• 1996

In following addition of 0.3, -0.6, 0.8, 1.0 and 5 weight percent MgSiF66H2O studies have been made of the setting and hardening characteristics of ordinary portland cement. MgSiF66H2O retarded the setting time of ordinary portland cement and extended the induction pariod of the hydration. In ordinary portland cement the setting characteristics were drastically altered especially at high MgSiF66H2O contents. Evidence was also obtained by the formation of a KSiF6 which was very fine particle. The results wee as follows. 1. Slump was slightly decreased when MgSiF66H2O added. 2. Setting time was retarded depending on the amount of retarding agent 2 to 8 hours 3. Compressive strength was almost same or some increased in comparision with opc. 4. When MgSiF66H2O was added to cement paste K2SiF6 were formed It was fine-sized distributed uniformly in cement grain and caused retardation of cement setting.

• Journal of the Korean Society of Tobacco Science
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• v.2 no.2
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• pp.20-37
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• 1980

Among the 34 strains of Nicotinophiles selected in the previous experiments, strain NCT27 identified with Pseudomonas putida and strain NCT30 identified with Arthrobacter oxydans biotype nan thus were Investigated for optimization of growth conditions for nicotine degradation and other cultural characteristics. The compositions of optimized medium were to be following: $KH_2PO_4$ 2.Ogr, KCI 5.Ogr, $MgSO_4$.$7H_2O$ 20mg, $MnSO_4$.$6H_2O$ 0.2mg, $FeSO_4$.$7H_2O$ 1.Omg, Col$^{++}$ (Cobalt Acetate),2.O$\gamma$, N1$^{++}$ (NiSO4,6H2O) 0.5$\gamma$, and yeast extract 80mg per liter. The optimum initial concentrations of nicotine for growth were 0.4% for Pseudomonas and 0.1% for Arthrobacter, respectively. The optimum temperature and pH were 3$0^{\circ}C$ and 7.0 for both of strains. The pH of culture medium of Pseudomonas was changed from acidic condition to basic one in going from the logarithmic growth phase to the stationary growth phase. In contrast with Pseudomonas, it remained constant in case of Arthrobacter. The growth of Arthrobacter was completely inhibited in the nicotine concentration of 0.7&. However, Pseudomonas could grow even in the nicotine concentration of 1.0%. Moreover, it could grow successfully in the tobacco extract media as well as media containing carbon and nitrogen sources other than nicotine. The maximum rates of nicotine degradation were to be 1.22 gr./hr./liter for Pseudomonas and 0.186 gr./hr./liter for Arthrobacter, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.996-1002
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• 2014

An experiment was conducted to evaluate the effects of dietary alpha-lipoic acid (LA) and acetyl-L-carnitine (ALC) on growth performance, carcass characteristics and meat quality in Arbor Acres broilers. A total of 486 1-d-old male Arbor Acres broilers were randomly allocated to 9 dietary treatments, 9 treatments were group A (0 mg/kg LA and 0 mg/kg ALC), group B (50 mg/kg LA and 0 mg/kg ALC), group C (100 mg/kg LA and 0 mg/kg ALC), group D (0 mg/kg LA and 50 mg/kg ALC), group E (50 mg/kg LA and 50 mg/kg ALC), group F (100 mg/kg LA and 50 mg/kg ALC), group G (0 mg/kg LA and 100 mg/kg ALC), group H (50 mg/kg LA and 100 mg/kg ALC), group I (100 mg/kg LA and 100 mg/kg ALC). Birds were slaughtered at 42 days old. Average daily gain (ADG), average feed intake (AFI), feed conversion rate (FCR), eviscerated rate, breast muscle percentage, thigh muscle percentage, abdominal fat percentage, liver weight, muscle color ($L^*$ value, $a^*$ value, $b^*$ value), pH values at 45 min and 24 h postmortem were measured. Results showed that there existed an interaction between LA and ALC in growth performance of broilers, carcass traits and meat quality. The overall result is that high level of LA and ALC led to lower AFI, ADG (p<0.01), lower abdominal fat percentage, liver weight (p<0.01), lower $L^*$ value, $a^*$ value, and $b^*$ value of breast muscle, $L^*$ value of thigh muscle (p<0.05), and higher FCR (p<0.01), eviscerated rate (p<0.01), breast muscle percentage, thigh muscle percentage (p<0.05), $a^*$ value, pH 45 min and pH 24 h of thigh muscle (p<0.01). These results suggested that dietary LA and ALC contributed to the improvement of meat quality in broilers.