• Title/Summary/Keyword: Manganese Oxide

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Effects of Graded Levels of Montmorillonite on Performance, Hematological Parameters and Bone Mineralization in Weaned Pigs

  • Duan, Q.W.;Li, J.T.;Gong, L.M.;Wu, H.;Zhang, L.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.11
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    • pp.1614-1621
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    • 2013
  • The aim of this study was to investigate the effects of graded levels of montmorillonite, a constituent of clay, on performance, hematological parameters and bone mineralization in weaned pigs. One hundred and twenty, 35-d-old crossbred pigs (Duroc${\times}$Large White${\times}$Landrace, $10.50{\pm}1.20$ kg) were used in a 28-d experiment and fed either an unsupplemented corn-soybean meal basal diet or similar diets supplemented with 0.5, 1.0, 2.5 or 5.0% montmorillonite added at the expense of wheat bran. Each treatment was replicated six times with four pigs (two barrows and two gilts) per replicate. Feed intake declined (linear and quadratic effect, p<0.01) with increasing level of montmorillonite while feed conversion was improved (linear and quadratic effect, p<0.01). Daily gain was unaffected by dietary treatment. Plasma myeloperoxidase declined linearly (p = 0.03) with increasing dietary level of montmorillonite. Plasma malondialdehyde and nitric oxide levels were quadratically affected (p<0.01) by montmorillonite with increases observed for pigs fed the 0.5 and 1.0% levels which then declined for pigs fed the 2.5 and 5.0% treatments. In bone, the content of potassium, sodium, copper, iron, manganese and magnesium were decreased (linear and quadratic effect, p<0.01) in response to an increase of dietary montmorillonite. These results suggest that dietary inclusion of montmorillonite at levels as high as 5.0% does not result in overt toxicity but could induce potential oxidative damage and reduce bone mineralization in pigs.

A Case of Metal Fume Fever Associated with Copper Fume in a Welder (용접공에서 발생한 구리흄에 의한 금속열 1례)

  • Lim, Hyun-Sul;Cheong, Hae-Kwan
    • Journal of Preventive Medicine and Public Health
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    • v.31 no.3 s.62
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    • pp.414-423
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    • 1998
  • Metal fume fever has been known as an occupational disease is induced by intense inhalation of fresh metal fume with a particle size smaller than $0.5{\mu}m\;to\;1{\mu}m$. The fumes originate from heating metals beyond their boiling point, as happens, for example, in welding operations. Oxidation usually accompanies this process. In most cases, this syndrome is due to exposure to zinc oxide fumes; however, other metals like copper, magnesium, cadmium, manganese, and antimony are also reported to produce such reactions. Authors report a case of metal fume fever suspected to be associated with copper fume inhalation. The patient was a 42-year-old male and was a smoker. He conducted inert gas tungsten arc welding on copper-coated materials without safety precautions such as a protective mask and adequate ventilation. Immediately after work, he felt metallic taste in his mouth. A few hours after welding, he developed headache, chilling sensation, and chest discomfort. He also complained of myalgia, arthralgia, feverish sensation, thirst, and general weakness. Symptoms worsened after repeated copper welding on the next day and subsided gradually following two weeks. Laboratory examination showed a transient increase of neutrophil count, eosinophilia, elevated erythrocyte sedimentation rate, and positive C-reactive proteinemia. Blood and urine copper level was also increased compared to his wife. Before this episode, he experienced above complaints several times after welding with copper materials but welding of other metals did not produce any symptoms. It was suggested that copper fume would have induced metal fume fever in this case. Further investigations are needed to clarify their pathogenic mechanisms.

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Trend on the Recycling Technologies for Spent Batteries by the Patent and Paper Analysis (특허(特許)와 논문(論文)으로 본 폐전지 재활용(再活用) 기술(技術) 동향(動向))

  • Shin, Shun-Myung;Joo, Sung-Ho;Kim, Soo-Kyung;Cho, Young-Ju;Cho, Bong-Gyoo
    • Resources Recycling
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    • v.21 no.4
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    • pp.16-25
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    • 2012
  • There are several kinds of batteries such as zinc-air battery, lithium battery, Manganese dry battery, silver oxide battery, sodium-sulphur battery, lead acid battery, metal hydride secondary battery, nickel-cadmium battery, lithium ion battery, alkaline battery, etc. These days it has been widely studied for the recycling technologies of the used battery from view points of economy and efficiency. In this paper, patents and published papers on the recycling technologies of the used battery were analyzed. The range of search was limited in the open patents of USA (US), European Union (EU), Japan (JP), Korea (KR) and SCI journal articles from 1972 to 2011. Patents and journal articles were collected using key-words searching and filtered by filtering criteria. The trends of the patents and journal articles were analyzed by the years, countries, companies, and technologies.

The Characteristics of Desulfurization using Metal Oxides in a Fluidized Bed Reactor (금속산화물을 이용한 유동층반응기에서 배연탈황특성)

  • Park, Tae Sung;Hong, Sung Chang
    • Applied Chemistry for Engineering
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    • v.9 no.2
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    • pp.278-285
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    • 1998
  • In a fixed bed reactor, adsorption capacity of $SO_2$ in simulated flue gases was investigated with NMO(natural manganese ore), composed of various metal oxides, iron ore and $CuO/{\gamma}-Al_2O_3$ as adsorbents. The experiment carried out in a fluidized bed reactor with variables such as gas velocity, temperature and particle size. Iron ore was excluded in the fluidized bed reactor experiment for the lower adsorption capacity. The adsorption of $SO_2$ in metal oxide is a typical chemisorption because the adsorption capacity of all adsorbents increased with temperature. The effect of particle size on the adsorption capacity was varied with the ratio, $U_o/U_{mf}$ and the difference of $U_o-U_{mf}$. $U_o$ is the gas velocity, $U_{mf}$ is the minimum fluidization gas velocity. $U_o/U_{mf}$ and $U_o-U_{mf}$ explain the behavior of the gas and solids in the fluidized bed reactor. From the performance equation of the fluidized bed reactor, kinetic reaction rate constants were obtained by the non-linear least square method. The adsorption capacity of NMO proved the potential use of $SO_2$ adsorbents.

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Study on 1,200 N-class bipropellant rocket engine using decomposed $H_2O_2$ and kerosene (분해된 과산화수소와 케로신을 이용한 1,200 N 급 이원추진제 로켓 엔진의 연구)

  • Jo, Sung-Kwon;An, Sung-Yong;Kim, Jong-Hak;Yoon, Ho-Sung;Kwon, Se-Jin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.14 no.6
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    • pp.69-78
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    • 2010
  • As part of preliminary study for development of 1,200 N-class bipropellant rocket engine with the concentrated hydrogen peroxide, bipropellant engine elements were designed and experimentally tested. The catalysts of $MnO_2$ and $MnO_2$ added Pb as an additive were compared to achieve high decomposition performance and the catalytic reactor with $MnO_2$ added Pb was designed and its decomposition efficiency of 97.2% was achieved. The autoignition tests of kerosene by decomposed hydrogen peroxide were carried out under various equivalence ratios to ignite without additional ignition sources. Autoignition were achieved in all experimental conditions and $C^*$ efficiencies at each condition were at or above 90%. From the measured thrust results, the highest value was 830 N which is in corresponds with 1,035 N at vacuum level assuming $C^*$ efficiency equals $I_{sp}$ efficiency.

Electrochemical Behavior Depending on Designed-Anode and Cathodes of Hybrid Supercapacitors (하이브리드 슈퍼커패시터의 음극 및 양극 설계에 따른 전기화학적 거동)

  • Shin, Seung-Il;Lee, Byung-Gwan;Ha, Min-Woo;An, Geon-Hyoung
    • Korean Journal of Materials Research
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    • v.29 no.12
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    • pp.774-780
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    • 2019
  • The performance of Li-ion hybrid supercapacitors (asymmetric-type) depends on many factors such as the capacity ratio, material properties, cell designs and operating conditions. Among these, in consideration of balanced electrochemical reactions, the capacity ratio of the negative (anode) to positive (cathode) electrode is one of the most important factors to design the Li-ion hybrid supercapacitors for high energy storing performance. We assemble Li-ion hybrid supercapacitors using activated carbon (AC) as anode material, lithium manganese oxide as cathode material, and organic electrolyte (1 mol L-1 LiPF6 in acetonitrile). At this point, the thickness of the anode electrode is controlled at 160, 200, and 240 ㎛. Also, thickness of cathode electrode is fixed at 60 ㎛. Then, the effect of negative and positive electrode ratio on the electrochemical performance of AC/LiMn2O4 Li-ion hybrid supercapacitors is investigated, especially in the terms of capacity and cyclability at high current density. In this study, we demonstrate the relationship of capacity ratio between anode and cathode electrode, and the excellent electrochemical performance of AC/LiMn2O4 Li-ion hybrid supercapacitors. The remarkable capability of these materials proves that manipulation of the capacity ratio is a promising technology for high-performance Li-ion hybrid supercapacitors.

Preparation of a Novel PU-LMO Adsorbent by Immobilization of LMO on Polyurethane Foam for Recovery of Lithium Ions (폴리우레탄 폼에 LMO를 고정화하여 리튬이온 회수를 위한 새로운 PU-LMO 흡착제의 제조)

  • You, Hae-Na;Lee, Min-Gyu
    • Clean Technology
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    • v.20 no.3
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    • pp.277-282
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    • 2014
  • In this study, PU-LMO was made by immobilization of LMO on urethane foam (PU) with using an EVA as a binder. PU-LMO was characterized by using X-Ray Diffractometer (XRD) and Scanning Electron Microscopy (SEM). The optimal ratio of EVA/LMO for preparation of PU-LMO was 0.26 gEVA/gLMO. The adsorption of lithium ions by PU-LMO was found to follow the pseudo-second-order kinetic model. The equilibrium data fitted well with Langmuir isotherm model and the maximum removal capacity of lithium ions was 17.09 mg/g. The PU-LMO was found to have a remarkably high selectivity of lithium ions and high adsorption capacity because the distribution coefficient ($K_d$) of lithium ion was higher than those of other metal ions.

Utilization of Mineral Oxides to Attenuate Mn-EDTA and Fluoride (산화광물을 이용한 수중의 망간-EDTA, 불소 제거)

  • 현재혁;남인영
    • Journal of Korea Soil Environment Society
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    • v.1 no.2
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    • pp.51-60
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    • 1996
  • Removal of Mn-EDTA complex and fluoride by use of hematite and ferrite, which are the by-product to be disposed of as industrial wastes, was investigated. For the comparison of removal rate, Na-bentonite known as excellent absorbent of inorganic contaminants was included in the experiments. As the results of batch mode experiments, for manganese, ferrite-A revealed 48∼65% of removal capacity, ferrite-B 46∼57%, hematite 17∼26%, while Na-bentonite showed 10∼23% of removal, depending on the initial concentration. Meanwhile, in case of fluoride : hematite revealed 53 ∼63% of removal : ferrite-A 54∼63 %, while ferrite-B did 20∼38 %. From the results, it can be postulated that the capacity of hematite and ferrite to attenuate inorganic pollutants, especially when they form complex ions, is superior to that of Na-bentonite. Consequently, the mixing of such oxide minerals with Na-bentonite will reinforce the function of Na-bentonite, especially in the undergroud liner aspect.

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Bone-like Apatite Morphology on Si-Zn-Mn-hydroxyapatite Coating on Ti-6Al-4V Alloy by Plasma Electrolytic Oxidation

  • Park, Min-Gyu;Choe, Han-Cheol
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2017.05a
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    • pp.158-158
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    • 2017
  • Titanium and its alloys have been used in the field dental and orthopedic implants because of their excellent mechanical properties and biocompatibility. Despite these attractive properties, their passive films were somewhat bioinert in nature so that sufficient adhesion of bone cells to implant surface was delayed after surgical treatment. Recently, plasma electrolyte oxidation (PEO) of titanium metal has attracted a great deal of attention is a comparatively convenient and effective technique and good adhesion to substrates and it enhances wear and corrosion resistances and produces thick, hard, and strong oxide coatings. Silicon(Si), Zinc(Zn), and Manganese(Mn) have a beneficial effect on bone. Si in particular has been found to be essential for normal bone and cartilage growth and development. And, Zn has been shown to be responsible for variations in body weight, bone length and bone biomechanical properties. Also, Mn influences regulation of bone remodeling because its low content in body is connected with the rise of the concentration of calcium, phosphates and phosphatase out of cells. The objective of this work was research on bone-like apatite morphology on Si-Zn-Mn-hydroxyapatite coating on Ti-6Al-4V alloy by plasma electrolytic oxidation. Anodized alloys were prepared at 280V voltage in the solution containing Si, Zn, and Mn ions. The surface characteristics of PEO treated Ti-6Al-4V alloy were investigated using XRD, FE-SEM, and EDS.

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Photochemical Oxidants Damage in Rice Plants (Photochemical Oxidants에 의한 수도피해(水稻被害) 해석(解析))

  • Jeong, Young-Ho
    • Korean Journal of Environmental Agriculture
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    • v.2 no.2
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    • pp.103-107
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    • 1983
  • The effect of photochemical oxidants on rice plants was measured by growing the rice plants Nihonbare in pot in charcoal-manganese oxide filtered atmosphere and non-filtered air. Visible injury on the leaf blades of rice plants were observed in plants grown under the unfiltered air chamber, but plants under filtered air chamber were free from any injury. Fresh weight of stem and root at maximum tillering stage in unfiltered chamber were 16.8 and 46.4% less than filtered air chamber, respectively. Grain yield in unfiltered air chamber was also reduced by 14.7% compared to that of filtered air chamber. And the reduced yield paralleled increase in concentration of oxidants in the atmosphere at the experimental site. ABA content in rice plants cultivated in unfiltered air chamber was higher than in filtered air chamber, but the root activity of rice plants in unfiltered air chamber was remarkably decreased.

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