• Asian-Australasian Journal of Animal Sciences
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• 제31권5호
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• pp.677-685
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• 2018

Objective: The objective of the present study was to determine ammonium chloride tolerance of lactating dairy cows, by examining effects of negative dietary cation anion difference (DCAD) induced by ruminal ammonium chloride infusion on performance, serum and urine minerals, serum metabolites and enzymes of lactating dairy cows. Methods: Four primiparous lactating Chinese Holstein cows fitted with ruminal cannulas were infused with increasing amounts (0, 150, 300, or 450 g/d) of ammonium chloride in a crossover design. The DCAD of the base diet was 279 mEq/kg dry matter (DM) using the DCAD formula (Na + K - Cl - S)/kg of DM. Ammonium chloride infusion added the equivalent of 0, 128, 330, and 536 mEq/kg DM of Cl in treatments. According to the different dry matter intakes (DMI), the resulting actual DCAD of the four treatments was 279, 151, -51, and -257 mEq/kg DM, respectively. Results: DMI decreased linearly as DCAD decreased. Yields of milk, 4% fat-corrected milk, energy-corrected milk, milk fat, and milk protein decreased linearly as DCAD decreased. Concentrations of milk protein and milk urea nitrogen increased linearly with decreasing DCAD. Concentration of Cl- in serum increased linearly and concentration of PO43- in serum increased quadratically as DCAD decreased. Urine pH decreased linearly and calculated urine volume increased linearly with decreasing DCAD. Linear increases in daily urinary excretion of $Cl^-$, $Ca^{2+}$, $PO_4{^{3-}}$, urea N, and ammonium were observed as DCAD decreased. Activities of alanine aminotransferase, aspartate aminotransferase, and ${\gamma}-glutamyl$ transferase in serum and urea N concentration in serum increased linearly as DCAD decreased. Conclusion: In conclusion, negative DCAD induced by ruminal ammonium chloride infusion resulted in a metabolic acidosis, had a negative influence on performance, and increased serum enzymes indicating potential liver and kidney damage in lactating dairy cows. Daily ammonium chloride intake by lactating dairy cows should not exceed 300 g, and 150 g/d per cow may be better.

• 분석과학
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• 제13권4호
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• pp.446-452
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• 2000

질산에 잘 녹지 않는 백금족 원소를 포함하고 있는 모의 사용후핵연료(SIMfUEL)를 고압산분해 방법으로 녹였다. 핵분열생성물 원소들은 우라늄과 분리한 다음 유도결합플라스마 원자방출분광법 (ICP-AES)으로 분석하였다. 핵분열생성물 원소들의 피크가 우라늄 스펙트럼으로부터 분광학적 간섭을 받으므로 Mo, Pd, Rh 및 Ru은 양이온교환수지로 Ba, Ce, La, Nd, Rh, Sr, Y 및 Zr는 음이온교환수지로 우라늄과 원소들을 군분리하였다. 사용후핵연료의 조성과 비슷한 모의 핵연료용액을 만들어 양이온 교환수지로 분리한 다음 측정한 회수율은 99-103%이고, 음이온교환수지로 분리하고 측정한 회수율은 이트륨을 제외하고 96.5-107%이었다. 이 방법을 금속원소의 농도가 수백에서 수천 ppm 존재하는 SIMFUEL에 적용하여 측정한 상대표준편차는 1.3-6.7%이었다.

• 대한수의학회지
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• 제52권1호
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• pp.57-59
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• 2012

In this study, we investigate the status of calcium (Ca) homeostasis at parturition in three dairy farms (I, II, and III), Heilongjiang, China. Twenty multiparous Holstein cows from each farm were randomly assigned to this experiment. The dietary cation-anion difference (DCAD) was 91 mEq/kg of DM for farm I, 152 mEq/kg of DM for farm II, and 85 mEq/kg of DM for farm III. Incidence of hypocalcemia was above 75% and urine pH was above 7.25 at calving in each farm. Compared to other farms, cows in farm II that fed the greatest positive DCAD had the lowest concentration of serum Ca, the highest concentration of serum PTH, and the greatest urine pH at calving (p < 0.05). However, there was not significant difference in serum 1,25-dihydroxy-vitamin D and hydroxyproline concentration of the cows among three farms. This is the first study to confirm that hypocalcemia is very prevalent at calving in Chinese dairy farms, and the high positive DCAD is a major risk factor that results in hypocalcemia at calving, which may reduce ability of the cow to maintain Ca homeostasis.

• 분석과학
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• 제26권1호
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• pp.11-18
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• 2013

과염소산 음이온은 암모니움 과염소산 염 형태로서 로켓의 추진체, 폭발물의 재료로 사용되는 물질이다. 고농도의 암모니움 과염소산은 비군사화과정을 통해 폐로켓으로부터 회수된다. 음용수나 음식을 통해 사람이 섭취하게 되면, 갑상선 호르몬을 합성하는데 필요한 물질인 요오드의 흡수를 방해하게 된다. 소량이라도 장기 노출 시 신장 및 갑상선 기능장애, 생식기능 장애 그리고 암을 유발할 수 있다. 따라서 수질에서의 과염소산이온을 효과적으로 제거할 수 있는 방법이 필요하다. 경제적인 관점을 고려하여, 본 연구에서는 이온교환수지에 흡착된 과염소산 이온을 효과적으로 탈착(재생)시킬 수 있는 조건을 최적화하는 것이 목적이다. pH, 탈착용액의 이온형태, 농도에 따라서 탈착량을 파악하였으며, 이온교환수지와 활성탄을 혼합한 혼합수지를 이용하여 탈착효율이 증가하는 시너지효과를 보았다.

• 한국의류산업학회지
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• 제12권2호
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• pp.240-245
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• 2010

The effects of monazite and fixing agents on cotton fabric dyed with Perilla frutescens var. acuta extract were investigated. The proper monazite treatment concentration, temperature and time were 10%(o.w.b.), $50^{\circ}C$ and 60minutes. By various fixing agent treatment, $FeSO_4$ showed a relatively high K/S value and the order of K/S value decreased as follows, cation surface active agents, soybean and NaCl. And the monazite and $FeSO_4$ fixing agent showed higher anion emissity than those of untreated cotton and other fixing agents. The cotton fabrics showed improved color fastness by monazite and fixing agents treatments with the exception of light fastness. And the cotton fabrics fixed with fixing agents were showed effective bacterial reduction with the exception of NaCl.

• 한국토양비료학회지
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• 제48권6호
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• pp.666-670
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• 2015

Competition among anion species in solution for same sorption sites and soil surface can be of major significance in determining the effective mobility of any potentially adsorbing species. Major soil anion species include $OH^-$, $F^-$, $Cl^-$, $HCO_3{^-}$, $CO_3{^-}$, $NO_3{^-}$, $SO_4{^{2-}}$, and $PO_4{^{3-}}$. And some micro nutrients such as boron and molybdenum exist as $H_2BO_3{^-}$ and $MoO_4{^{2-}}$, as do some heavy metals such as chrome and arsenic as $CrO_4{^{2-}}$ and $HAsO_4{^{2-}}$. Pesticides such as 2,4,5-T and 2,4-D also exist as anions. Many anion species are retained by more complex mechanisms than the simple electrostatic attractions involved in most cation adsorption reactions. In binary system composed of two anions, the adsorption of one anion is influenced by the other anion due to the competition for the available and limited binding sites in soil constituents. The specifically adsorbed anions may compete more effectively for sorption sites than that of nonspecifically adsorbed anion. In this study, we aim to evaluate the mathematical models to determine the magnitude of concentration variations in adsorption due to competitive interactions between anions introduced to a system in binary mixtures.

• The Korean Journal of Physiology and Pharmacology
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• 제21권4호
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• pp.371-376
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• 2017

The caudal subnucleus of the spinal trigeminal nucleus (medullary dorsal horn; MDH) receives direct inputs from small diameter primary afferent fibers that predominantly transmit nociceptive information in the orofacial region. Recent studies indicate that reactive oxygen species (ROS) is involved in persistent pain, primarily through spinal mechanisms. In this study, we aimed to investigate the role of xanthine/xanthine oxidase (X/XO) system, a known generator of superoxide anion ($O_2{^-}$), on membrane excitability in the rat MDH neurons. For this, we used patch clamp recording and confocal imaging. An application of X/XO ($300{\mu}M/30mU$) induced membrane depolarization and inward currents. When slices were pretreated with ROS scavengers, such as phenyl N-tert-butylnitrone (PBN), superoxide dismutase (SOD), and catalase, X/XO-induced responses decreased. Fluorescence intensity in the DCF-DA and DHE-loaded MDH cells increased on the application of X/XO. An anion channel blocker, 4,4-diisothiocyanatostilbene-2,2-disulfonic acid (DIDS), significantly decreased X/XO-induced depolarization. X/XO elicited an inward current associated with a linear current-voltage relationship that reversed near -40 mV. X/XO-induced depolarization reduced in the presence of $La^{3+}$, a nonselective cation channel (NSCC) blocker, and by lowering the external sodium concentration, indicating that membrane depolarization and inward current are induced by influx of $Na^+$ ions. In conclusion, X/XO-induced ROS modulate the membrane excitability of MDH neurons, which was related to the activation of NSCC.

• 전기화학회지
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• 제2권4호
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• pp.183-189
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• 1999

원자력 시설의 가동 및 유지보수 중에 중$\cdot$저준위 방사성폐기물로 다량 생성되는 폐 유기이온교환수지를 상온의 수용 상 내에서 분해 처리하는 공정을 개발할 목적으로, 전기화학적으로 생성되는 Ag(II)를 매개산화제로 사용하여 양이온 및 음이온교환수지의 분해 연구를 수행하였다. Ag(II) 매개산화 공정에서 제어 가능한 인자인 전류, 온도 및 전해질 농도가 이온교환수지의 분해거동에 미치는 영향을 고찰하였다. 양이온교환수지는 거의 대부분 $CO_2$로 분해되었으며, 전류밀도가 감소할수록 전류효율이 증가됨을 보인 반면에 양극전해질로 사용된 질산의 농도 및 온도가 증가하더라도 분해거동에는 영향을 미치지 않았다. 양이온교환수지와는 달리 음이온교환수지의 분해시에는 온도와 무관하게 약 $10\%$ 정도가 CO로 분해되었고, $CO_2$로의 분해효율은 온도에 의존하는 경향을 보였으며, $60^{\circ}C$ 이상에서 효과적으로 분해가 가능하였다.

• Corrosion Science and Technology
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• 제7권1호
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• pp.40-44
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• 2008

Passive metal forms an interfacial diffuse layer on the surface of passive film by its reaction with $H^+$ or $OH^-$ ions in solution depending on solution pH. There is a critical pH, called pH point of iso-selectivity ($pH_{pis}$) at which the nature of the diffuse layer is changed from the anion-permeable at pH<$pH_{pis}$ to the cation-permeable at pH>$pH_{pis}$. The $pH_{pis}$ for a passivated Fe was determined by examining the effects of pH on the thickness of passive film and on the dissolution reaction occurring on the passive film under a gavanostatic reduction in borate-phosphate buffer solutions at various pH of 7~11. The steady-state thickness of passive film formed on Fe showed the maximum at pH 8.5~9, and further the nature of film dissolution reaction was changed from a reaction producing $Fe^{3+}$ ion at $pH\leq8.5$ to that producing $FeO_2{^-}$ at $pH\geq9$, suggesting that the $pH_{pis}$ of Fe is about pH 8.5~9. In addition, the passive film formed at pH 8.5~9, $pH_{pis}$, was found to be the most protective with the lowest defect density as confirmed by the Mott-Schottky analysis. Pitting potential was decreased with increasing $Cl^-$ concentration at $pH\leq8.5$ due probably to the formation of anion permeable diffuse layer, but it was almost constant at $pH\geq9$ irrespective of $Cl^-$ concentration due primarily to the formation of cation permeable diffuse layer on the film, confirming again that $pH_{pis}$ of Fe is 8.5~9.

• 한국응용과학기술학회지
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• 제23권1호
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• pp.45-53
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• 2006

In this study, we prepared porous cation exchange membrane using polystyrene such as, EPS (expanded polystyrene), SAN (styrene acrylonitrile copolymer) and HIPS (high impactive polystyrene). These polystyrenes were sulfonated by acetyl sulfate to make porous cation exchange membrane such as, SEPS, SSAN, SHIPS. SEM was employed to confirm porous structure of membrane, and IR spectroscopy was used to confirm sulfonation rate of ion exchange membrane. Water and methanol content were also increased with amount of sulfuric acid in reactants. SSAN-20 showed the highest value in water and methanol content. Fixed ion concentration and conductivity was also increased with an amount of sulfuric acid in reactants. Methanol permeability for SEPS-20, SSAN-20, SHIPS-20 was found to be $1.326\;{\times}\;10^{-5}\;cm^2/s$, $1.527\;{\times}\;10^{-5}\;cm^2/s$ and $1.096\;{\times}\;10^{-5}\;cm^2/s$ respectively. From the result of electrodialysis experiment in 0.03 M $Pb(NO_3)_2$ aqueous solution, anion exclusion and cation selection effects were confirmed.