• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 INTERNATIONAL SYMPOSIUM ON SOIL & GROUNDWATER ENVIRONMENT
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• pp.185-186
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• 2005

• Asian-Australasian Journal of Animal Sciences
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• 제19권10호
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• pp.1450-1454
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• 2006

Three hundred and seventy-five steers (approximately 7 mo of age and $239.0{\pm}10.4kg$) were utilized to determine the effects of trace mineral (TM) supplementation and source on performance during the on-farm backgrounding and feedlot receiving phases of beef cattle production. At their respective ranches, steers were stratified by body weight into six groups. Groups were then assigned to one of six pens and pens were randomly assigned to treatments. Treatments consisted of: 1) control (no supplemental Cu, Zn, Mn, and Co), 2) inorganic trace mineral ($CuSO_4$, $ZnSO_4$, $MnSO_4$, and $CoCO_3$), and 3) organic trace mineral (iso-amounts of organic Cu, Zn, Mn, and Co). Mineral treatments were fed in alfalfa pellets formulated to supply 360 mg of Zn, 200 mg of Mn, 125 mg of Cu, and 12.5 mg of Co per head per day from either organic or inorganic trace mineral sources. Control steers received alfalfa pellets with no additional Cu, Zn, Mn, or Co. Steers were allowed free access to harvested alfalfa-grass hay throughout the 30-d on-farm backgrounding phase. On day 30 post-weaning, steers were weighed and transported to the feedlot. Steers were blocked by treatment within ranch, stratified by initial body weight, and randomly assigned to one of 36 pens (9-12 head per pen; 12 pens per treatment). Steers remained on the same on-farm backgrounding trace mineral treatments, however, trace mineral treatments were included in the total mixed growing ration. Steers were fed a corn silage-based growing diet throughout the 28 d feedlot receiving period. There was no effect of TM supplementation on performance of steers during the on-farm backgrounding phase. By the end of the 28-d feedlot receiving phase, ADG was similar between control and trace mineral supplemented steers. Steers supplemented with organic TM had greater (p<0.05) ADG than steers supplemented with inorganic TM by the end of the 28-d feedlot receiving phase. Morbidity and mortality rates were similar across treatments.

• Asian-Australasian Journal of Animal Sciences
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• 제31권2호
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• pp.252-262
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• 2018

Objective: An experiment was conducted to evaluate dietary supplemental trace mineral source and deletion on mineral content in tissues. Methods: Weanling crossbred pigs (n = 144; 72 barrows and 72 gilts; body weight [BW] = $7.4{\pm}1.05kg$) were used. A basal diet was prepared, and trace mineral premix containing either inorganic (ITM) or organic (OTM) trace minerals (Cu, Fe, Mn, and Zn) was added to the basal diet. Pigs were blocked by sex and BW and randomly allotted to 24 pens for a total of 6 pigs per pen, and fed a diet containing either ITM or OTM supplemented at the 1998 NRC requirement estimates for each of 5 BW phases (Phase I to V) from 7 to 120 kg. The trace mineral supplementation was deleted for 6, 4, 2, and 0 wk of Phase V; regarding nutrient adequacy during this phase, the indigenous dietary Fe and Mn was sufficient, Cu was marginal and Zn was deficient. Results: At the end of Phase IV, Mn content (mg/kg on the dry matter basis) was greater (p<0.05) in heart (0.77 vs 0.68), kidney (6.32 vs 5.87), liver (9.46 vs 8.30), and longissimus dorsi (LD; 0.30 vs 0.23) of pigs fed OTM. The pigs fed OTM were greater (p<0.05) in LD Cu (2.12 vs 1.89) and Fe (21.75 vs 19.40) and metacarpal bone Zn (141.86 vs 130.05). At the end of Phase V, increased length of deletion period (from 0 to 6 wk) resulted in a decrease (linear, p<0.01) in liver Zn (196.5 to 121.8), metacarpal bone Zn (146.6 to 86.2) and an increase (linear, p<0.01) in heart Mn (0.70 to 1.08), liver Mn (7.74 to 12.96), and kidney Mn (5.58 to 7.56). The only mineral source by deletion period interaction (p<0.05) was observed in LD Zn. Conclusion: The results demonstrated differential effects of mineral deletion on tissue mineral content depending on both mineral assessed and source of the mineral.

• 자원리싸이클링
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• 제14권6호
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• pp.10-15
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• 2005

본 연구는 Karr column을 이용한 희토류원소의 분리에 대한 연구로서, 유량, 수상의 초기 pH, 유기상인 PC88A비누화도, 교반속도 등의 변수에 따른 Sm/ND이성분계의 분리특성을 조사하였다. 수상과 유기상의 유량이 16.5ml/min(체류시간 10분)에서 수상의 초기 pH가 높아짐에 따라 Sm/Nd의 추출율 및 분리계수가 증가하였으며, 비누화의 영향으로 반응 후 수상의 평형 pH가 약 1.5정도로 유지되었다 또한 PC88A 비누화도가 증가함에 따라 추출율 및 분리계수가 증가하였으며 적정 비누화도는 $40\%$였다. 그리고 교반 모터의 회전수 증가에 의해 추출율 및 분리계수가 크게 증가하는 결과를 보였다. 체류시간 10분, 초기 pH 1, PC88A비누화도 $40\%$,교반속도 120rpm에서 Nd $19.6\%$, Sm $72.5\%$가 추출되었다.

• 자원리싸이클링
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• 제18권6호
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• pp.3-9
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• 2009

본 총설은 용매추출(또는 액-액 추출)에 대한 일반적인 원리와 추출제별 용매추출 공정의 기초 원리를 소개하고 있다. 용매추출은 서로 섞이지 않는 두 상(phase)간에 화합물이 한 상(phase)에서 다른 상으로 이동하는 현상을 이용하는 공정이다. 초기에는 분석화학 분야에서 용매추출의 간편성, 신속성 및 넓은 적용성 때문에 많이 사용되었으며, 분액깔데기와 같은 간단한 도구로 수분내에 추출실험을 완료할 수 있다는 장점이 있다.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2003년도 International Symposium on Clean Environment
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• pp.135-138
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• 2003

Based on solid phase extraction, gas chromatography and mass spectrometry procedure for determining phenol and its derivatives in natural water was presented. In solid phase extraction, three types of techniques using solid phase adsorption material were treated with acid and salt, and converted second portion of acetyl derivatives. Under the these condition, extraction efficiency and detection ability dependent on extraction methods were discussed. Obtained results using optimized solid phase extraction techniques showed more convenience, simplifier and lower cost than the conventional analytical methods with holding wide dynamic range and lower detection limits.

• Ocean and Polar Research
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• 제26권4호
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• pp.647-653
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• 2004

Experimental studies with 4.3m and enlarged 30m in height have been conducted to investigate the flow characteristics of solid-liquid mixture in a lifting pipe and to acquire the design data for sea tests that will be performed in the future. From the results, it was observed that the more the discharged volume fraction and the solid diameter increase, the more the hydraulic gradient increases. Also, the more the diameter of the lifting pipe increases, the smaller the friction loss, and consequently, the less pressure drop and hydraulic gradient. From the enlarged hydraulic pumping experiments, it was shown that the results of the experiments were matched with those of the numerical model previously developed. On the bases of these studies, we plan to conduct further experiments and validate the hydraulic pumping model.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.618-623
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• 2003

Solvent extraction experiments for separation of impurities from Ni-rich solution were carried out for manufacturing of high purity Ni compounds from acid leaching solution of spent Ni-Cd secondary battery. Artificial and leaching solutions were used as aqueous phases and PC88A saponified by sodium in kerosene were used as organic phase. The extraction order is Zn>Mn>Co>Ni and extraction percentage of metal ions was increased with increase of the concentration of extractant, initial pH of aqueous phase and ratio of O/A. The separation of cobalt, zinc and manganese from nickel was effectively accomplished at the condition of extraction stage=l, O/A=1 and initial pH 5.0 with 1.0 $mol/dm^3$ PC88A saponified to $50\%$ with NaOH.

• 한국재료학회지
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• 제15권5호
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• pp.306-312
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• 2005

The hydrogen sorption properties of $Ti_{0.3}Zr_{0.2}V_{0.5}$ NEC(non-evaporable getter) alloy and its hydrides were evaluated at room temperature. The alloy and hydride powders were prepared by the Hydride-DeHydride(HDH) method. The hydrogen sorption speed of $Ti_{0.3}Zr_{0.2}V_{0.5}$ alloy was measured to increase with the amounts of hydride phase in the getter. The hydrogen sorption speeds of $Ti_{0.3}Zr_{0.2}V_{0.5},\;(Ti_{0.3}Zr_{0.2}V_{0.5})H_{1.52},\;and\;(Ti_{0.3}Zr_{0.2}V_{0.5})H_{1.94}$ were 2.22, 3.14 and 5.08 liter/sec, respectively. The unexpected enhancement of hydrogen sorption speed with the presence of the hydride phase is considered to be due to the pre-saturation of hydrogen trap sites which can retard the diffusion of hydrogen in the alloy.

• Asian-Australasian Journal of Animal Sciences
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• 제22권9호
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• pp.1279-1287
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• 2009

Concentrated livestock production has led to soil nutrient accumulation concerns. To reduce the environmental impact, it is necessary to understand current recommended livestock feeding practices. Two experiments were conducted to compare the effects of trace mineral supplementation on performance, carcass composition, and fecal mineral excretion of phase-fed, grow-finish pigs. Crossbred pigs (Experiment 1 (Exp. 1), (n = 528); Experiment 2 (Exp. 2), (n = 560)) were housed in totally-slatted, confinement barns, blocked by weight, penned by sex, and randomly assigned to pens at approximately 18 kg BW. Treatments were allocated in a randomized complete block design (12 replicate pens per treatment) with 9 to 12 pigs per pen throughout the grow-finish period. In Exp. 1, the control diet (Io100) contained Cu as $CuSO_{4}$, Fe as $FeSO_{4}$, and Zn (of which 25% was ZnO and 75% was $ZnO_{4}$) at concentrations of 63 and 378 mg/kg, respectively. Treatment 2 (O100) contained supplemental Cu, Fe, and Zn from organic sources (Bioplex, Alltech Inc., Nicholasville, KY) at concentrations of 19, 131, and 91 mg/kg, respectively, which are the commercially recommended dietary inclusion levels for these organic trace minerals. Organic Cu, Fe, and Zn concentrations from O100 were reduced by 25% and 50% to form treatments 3 (O75) and 4 (O50-1), respectively. In Exp. 2, treatment 5 (Io25) contained 25% of the Cu, Fe, and Zn (inorganic sources) concentrations found in Io100. Treatment 6 (O50-2) was identical to the O50-1 diet from Exp. 1. Treatment 7 (O25) contained the experimental microminerals reduced by 75% from concentrations found in O100. Treatment 8 (O0) contained no trace mineral supplementation and served as a negative control for Exp. 2. In Exp. 1, tenth-rib backfat, loin muscle area and ADG did not differ (p>0.05) between treatments. Pigs fed the control diet (Io100) consumed less feed (p<0.01) compared to pigs fed diets containing organic trace minerals, thus, G:F was greater (p = 0.03). In Exp. 2, there were no differences among treatment means for loin muscle area, but pigs fed the reduced organic trace mineral diets consumed less (p<0.05) feed and tended (p = 0.10) to have less tenth-rib backfat compared to pigs fed the reduced inorganic trace mineral diet. Considering that performance and feed intake of pigs was not affected by lower dietary trace mineral inclusion, mineral excretion could be reduced during the grow-finish phase by reducing dietary trace mineral concentration.