• Asian-Australasian Journal of Animal Sciences
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• 제8권3호
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• pp.249-254
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• 1995

The effects of bentonite (B) on rumen protozoal population and rumen fluid characteristics of sheep fed palm kernel cake (PKC) were studied for a period of 21 days. Two groups, each comprising two sheep were fed either PKC or PKC + B ad libitum A third group was left at pasture. Rumen fluid was sampled through a rumen cannula three times daily from all animals. Palm kernel cake contained 16% crude protein, 1 % crude fat and high amounts of copper, zinc, iron and manganese. Protozoal population in the rumen fluid decreased significantly (p < 0.05) after the onset of feeding PKC or PKC + B. However, sheep given bentonite supplementation at 2% of the dietary dry matter, maintained higher protozoal densities ($15{\times}10^4/ml$) when compared to animals fed only PKC ($8{\times}10^4/ml$). With both diets, the protozoa were mainly of the small entodinia species. Animals at pasture had higher protozoal population ($47{\times}10^4/ml$) with varying species of entodiniomorphids and holotrichs. Rumen fluid pH and ammonia concentration was significantly (p < 0.05) higher in animals at pasture compared to animals fed PKC or PKC + B. Volatile fatty acid concentration was significantly (p < 0.05) lower in animals fed PKC when compared to animals at pasture. There was a shift in fermentation pattern in animals fed PKC or PKC + B towards a lower acetate; and higher propionate, isovalerate and valerate. Studies in vitro also showed the positive effect of bentonite on protozoal numbers.

• 분석과학
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• 제12권6호
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• pp.498-503
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• 1999

2-hydroxy-1-naphthaldehyde와 aromatic amine으로부터 $N_2O_2$형의 네자리 schiff base 리간드인 Bis(2-hydroxy-1-naphtyllidine)-o-toluene-diimine;[$NOTDH_2$]를 합성하였다. 이 리간드와 cobalt(II), nickel(II) 및 copper(II) Acetate들과 반응시켜 schiff base 전이금속(II) 착물들을 합성하였으며 원소분석, IR, UV-vis, NMR 분광법 및 TGA로부터 착물들의 구조를 확인하였다. 중심 금속인 전이금속(II) 이온은 $N_2O_2$형의 주개원자를 갖는 네자리 리간드의 페놀에 있는 산소와는 이온결합을, aromatic amine의 질소와는 배위결합을 형성하여 비이온성의 착물을 형성하였다. $N_2O_2$형의 네자리 Schiff Base 전이금속(II) 착물에서 리간드와 금속이온들은 전이금속(II) 이온과 1:1로 결합하며 Cu(II)착물들은 4배위 구조임을 알았으며, Co(II) Ni(II)착물들은 2분자의 수화물이 배위된 6배위 착물 구조임을 알았다.

• 분석과학
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• 제6권5호
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• pp.435-442
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• 1993

루빈산이 결합된 카르복시메틸화된 폴리아민-폴리우레아(RCCPPI) 수지가 클로로카르복시메틸화된 폴리아민-폴리우레아(CCPPI) 수지와 루빈산으로부터 1단계 반응에 의하여 합성되었다. 이 수지의 구조는 적외선 분광광도법, 원소분석 및 시차열분석법으로 확인되었다. 이 수지에 대한 중금속 흡착특성은 용액의 pH를 변화시키면서 뱃치법에 의하여 분포계수($K_d$)를 측정하고, 프론탈크로마토그래피법으로 관류점을 측정하여 조사하였다. 중금속 이온용액을 이 수지로 충진된 관에 통과시킴에 의하여 고농도의 나트륨, 칼슘 및 아세트산염 용액 중에 존재하는 미량 중금속 이온을 최적 pH에서 농축 및 회수 정량할 수 있었다. 농축 인자는 25 이상이었고 흡착된 중금속들은 0.025M EDTA 용액(pH 9.0)으로 회수 정량하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권8호
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• pp.1130-1134
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• 2005

An experiment was performed using 20 calves of about one-month old to investigate the effect of chelation therapy with calcium disodium ethylenediaminetetraacetate ($CaNa_2$EDTA) alone or along with antioxidant $\alpha$-tocopherol in lead loaded calves on blood trace minerals, erythrocytic sulfahydryl groups and some haematobiochemical parameters. Fifteen calves were given lead orally at a daily dose of 7.5 mg of 99% pure lead acetate/kg body weight for 28 days. Then the lead was withdrawn on day 28 and the calves were randomly divided into three groups. Each group of five animals was either treated with $CaNa_2$EDTA alone at the dose rate of 110 mg/kg body weight in two divided doses for 4 days or along with $\alpha$-tocopherol at the dose rate of 100 mg/kg body weight orally daily for 7 days, keeping the remaining five calves as lead-exposed untreated controls. Blood samples were collected at the end of the lead exposure (day 0) and thereafter on day 2, 4, 7 and 10 from the start of the chelation treatment. The treatment with EDTA alone led to slow but non-significant improvement in blood copper level, but incorporation of antioxidant $\alpha$-tocopherol in chelation therapy resulted in its significant decline, as recorded on day 7-post treatment. Withdrawal of lead or treatment with $CaNa_2$EDTA alone or along with $\alpha$-tocopherol enhanced the erythrocytic thiol contents and the levels of T-SH and P-SH became statistically (p<0.05) comparable to those of lead-exposed controls by day 7 and 4, respectively. There was no significant (p>0.05) change in serum urea, creatinine, total protein and albumin levels between the treatment groups. It is concluded from the present investigation that treatment with $CaNa_2$EDTA at the present dose rate is safe to be used for chelation in lead loaded calves.

• Journal of the Korean Wood Science and Technology
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• 제37권4호
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• pp.406-413
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• 2009

전통 오방색 중 흑색 재현을 위하여 오배자, 신나무 잎, 감즙, 밤껍질, 묵즙 등을 이용하여 한지에 천연염색을 실시하였다. 흑색 염색을 위해 염료별 단독염색 및 복합염색을 행하였고, 매염제 및 염색순서를 달리하여 색상의 발현 특성을 조사하였다. 아울러 염료의 농도(o.w.f) 변화에 따른 염색 특성을 조사하여 흑색 발현을 위한 최적 염색조건을 구명하였다. 한지의 흑색 천연염색 발현에 있어 오배자가 가장 중요한 염료 물질로 나타났으며, 복합염색의 경우 오배자 염색 $\rightarrow$ 초산구리 매염 $\rightarrow$ 신나무 잎 염색 $\rightarrow$ 철 매염의 순서가 가장 우수한 흑색염색 특성을 나타냈다.

• 대한방사성의약품학회지
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• 제4권2호
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• pp.80-84
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• 2018

$[^{13}N]$Ammonia or $[^{13}N]NH_3$ is one of the most widely used PET tracer for the measurement of MBF. To produce $[^{13}N]NH_3$, devarda's alloy which contains aluminum, copper and zinc is used for the purpose of reduction from $^{13}N$-nitrate/nitrite to $[^{13}N]NH_3$. Since aluminum has neurotoxicity and renal toxicity, the amount of it should be carefully limited for the administration to the human body. Although USP and EP provide a way to identify the aluminum ion concentration, there are some difficulties to perform. Therefore, we tried to develop the modified method for verifying aluminum concentration of test solution. We compared color between test and standard solutions using chrome azurol S in pH 4.6 acetate buffer. We also tested color change of test and standard solutions according to pH, amounts and the order of reagent and time difference These results demonstrated that the color change of the solution can reflect quantitatively measure aluminum ion concentration. We hope the method is to be used effectively and practically in many sites where $[^{13}N]NH_3$ is produced.

• 대한화학회지
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• 제61권1호
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• pp.29-33
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• 2017

Formation of Au particles in nonstoichiometric $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$) oxide from aniline + hydrochloric acid mixtures and chloroauric acid in the ratios 30 : 1; 60 : 1; 90 : 1 (S1-S3) by volume and 0.01 mol of copper acetate, $Cu(OCOCH_3)_2.H_2O$, in each case is performed by sol-gel growth. Powder x-ray diffraction (XRD) results show Au particles are dispersed in tetragonal nonstoichiometric dicopper (I) dicopper (II) oxides, $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$). Average crystallite sizes of Au particles determined using Scherrer equation are found to be in the approximate ranges ${\sim}85-140{\AA}$, ${\sim}85-150{\AA}$ and ${\sim}80-150{\AA}$ in S1-S3, respectively which indicate the formation of Au nano-micro size particles in $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$) oxides. Hysteresis behaviour at 300 K having low loop areas and magnetic susceptibility values ${\sim}5.835{\times}10^{-6}-9.889{\times}10^{-6}emu/gG$ in S1-S3 show weakly ferromagnetic nature of the samples. Broad and isotropic electron paramagnetic resonance (EPR) lineshapes of S1-S4 at 300, 77 and 8 K having $g_{iso}$-values ${\sim}2.053{\pm}0.008-2.304{\pm}0.008$ show rapid spin-lattice relaxation process in magnetic $Cu^{2+}$ ($3d^9$) sites as well as delocalized electrons in Au ($6s^1$) nano-micro size particles in the $Cu_{2-x}{^I}Cu{_2}^{II}O_{3-{\delta}}$ ($x{\approx}0.20$; ${\delta}{\approx}0.10$) oxides. Broad and weak UV-Vis diffuse reflectance optical absorption band ~725 nm is assigned to $^2B_{1g}{\rightarrow}^2A_{1g}$ transitions, and the weak band ~470 nm is due to $^2B_{1g}{\rightarrow}^2E_g$ transitions from the ground state $^2B_{1g}$(${\mid}d_{x^2-y^2}$>) of $Cu^{2+}$ ($3d^9$) ions in octahedral coordination having tetragonal distortion.

• 분석과학
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• 제28권3호
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• pp.182-186
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• 2015

본 연구는 상온에서 과망간산칼륨 (KMnO₄)과 망간아세테이트 (Mn(CH₃COO)₂·4H₂O) 수용액을 반응시켜 초산구리 (Cu(CH₃COO)₂·H₂O) 수용액을 공침한 다공성 CuO/MnO₂ 촉매에 대한 물리화학적 특성에 대해 분석하였다. 합성방법은 KMnO₄과 Mn(CH₃COO)₂·4H₂O의 반응 몰비율을 0.3:1, 0.6:1, 1:1로 반응시켜 초산구리 수용액을 망간아세테이트 투입량 대비 10~75 wt%로 공침시켜 구리이온을 담지시켰다. 제조된 촉매는 TGA/DTA, XRD, SEM 및 BET를 통해 촉매에 대한 물리화학적 특성을 분석하였고, 그 결과 반응 몰비율 변화에 따라 γ-MnO₂, α-MnO₂로 상변이가 이루어 졌으며, 반응 몰비율이 0.6:1 일 때 비표면적이 253 m²/g을 갖는 다공성 CuO/γ-MnO₂ 촉매가 제조되었다.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 1998년도 가을 학술발표회 프로그램
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• pp.2-4
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• 1998

Proliferation of Nocardia amarae cells in activated sludge has often been associated with the generation of nuisance foams. Despite intense research activities in recent years to examine the causes and control of Nocardia foaming in activated sludge, the foaming continued to persist throughout the activated sludge treatment plants in United States. In addition to causing various operational problems to treatment processes, the presence of Nocardia may have secondary effects on the fate of heavy metals that are not well known. For example, for treatment plants facing more stringent metal removal requirements, potential metal removal by Nocardia cells in foaming activated sludge would be a welcome secondary effect. In contrast, with new viosolid disposal regulations in place (Code o( Federal Regulation No. 503), higher concentration of metals in biosolids from foaming activated sludge could create management problems. The goal of this research was to investigate the metal sorption property of Nocardia amarae cells grown in batch reactors and in chemostat reactors. Specific surface area and metal sorption characteristics of N. amarae cells harvested at various growth stages were compared. Three metals examined in this study were copper, cadmium and nickel. Nocardia amarae strain (SRWTP isolate) used in this study was obtained from the University of California at Berkeley. The pure culture was grown in 4L batch reactor containing mineral salt medium with sodium acetate as the sole carbon source. In order to quantify the sorption of heavy metal ions to N amarae cell surfaces, cells from the batch reactor were harvested, washed, and suspended in 30mL centrifuge tubes. Metal sorption studies were conducted at pH 7.0 and ionlc strength of 10-2M. The sorption Isotherm showed that the cells harvested from the stationary and endogenous growth phase exhibited significantly higher metal sorption capacity than the cells from the exponential phase. The sequence of preferential uptake of metals by N. amarae cells was Cu>Cd>Ni. The specific surFace area of Nocardia cells was determined by a dye adsorption method. N.amarae cells growing at ewponential phase had significantly less specific surface area than that of stationary phase, indicating that the lower metal sorption capacity of Nocardia cells growing at exponential phase may be due to the lower specific surface area. The growth conditions of Nocardia cells in continuous culture affect their cell surface properties, thereby governing the adsorption capacity of heavy metal. The comparison of dye sorption isotherms for Nocardia cells growing at various growth rates revealed that the cell surface area increased with increasing sludge age, indicating that the cell surface area is highly dependent on the steady-state growth rate. The highest specific surface area of 199m21g was obtained from N.amarae cell harvested at 0.33 day-1 of growth rate. This result suggests that growth condition not only alters the structure of Nocardia cell wall but also affects the surface area, thus yielding more binding sites of metal removal. After reaching the steady-state condition at dilution rate, metal adsorption isotherms were used to determine the equilibrium distributions of metals between aqueous and Nocardia cell surfaces. The metal sorption capacity of Nocardia biomass harvested from 0.33 day-1 of growth rate was significantly higher than that of cells harvested from 0.5- and 1-day-1 operation, indicatng that N.amarae cells with a lower growth rate have higher sorpion capacity. This result was in close agreement with the trend observed from the batch study. To evaluate the effect of Nocardia cells on the metal binding capacity of activated sludge, specific surface area and metal sorption capacity of the mixture of Nocardia pure cultures and activated sludge biomass were determined by a series of batch experiments. The higher levels of Nocardia cells in the Nocardia-activated sludge samples resulted in the higher specific surface area, explaining the higher metal sorption sites by the mixed luquor samples containing greater amounts on Nocardia cells. The effect of Nocardia cells on the metal sorption capacity of activated sludge was evaluated by spiking an activated sludge sample with various amounts of pre culture Nocardia cells. The results of the Langmuir isotherm model fitted to the metal sorption by various mixtures of Nocardia and activated sludge indicated that the mixture containing higher Nocardia levels had higher metal adsorption capacity than the mixture containing lower Nocardia levels. At Nocardia levels above 100mg/g VSS, the metal sorption capacity of activate sludge increased proportionally with the amount of Noeardia cells present in the mixed liquor, indicating that the presence of Nocardia may increase the viosorption capacity of activated sludge.