• Title/Summary/Keyword: Boron functional group

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Separation Reaction Characteristics of Boron Ion by Ion Exchange Method (이온교환법을 이용한 해수 중 붕소이온 분리 반응 특성)

  • Jung Boo-Young;Kang Suk-Hwan;Lee Jae-Chun;Hwang Taek-Sung
    • Polymer(Korea)
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    • v.30 no.1
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    • pp.45-49
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    • 2006
  • In this study, it was investigated on the boron separation ken synthetically prepared seawater. ion exchange resin used in the experiments was Amberlite IRA 743, containing glucamine functional group. The experiments were carried out as a function of the conditions of the pH, boron initial concentration and temperature of seawater in a batch reactor. As a result, optimum conditions for boron adsorption were at pH 8.5 and 313 K, respectively. The adsorption rate was increased very fast with increasing the temperature, but decreased with increasing the initial concentration of boron. Also, the kinetics for boron adsorption applied the pseudo-second order model, as follows: $$\frac{X}{1-X}=780[C_0]^{-1.65}t^{1.48}\;exp\;({-\frac{17883}{RT}}\)\;;\;pH8.5$$

Development of Boron Doped Carbon Using CO2 Reduction with NaBH4 for Vanadium Redox Flow Battery (수소화 붕소 나트륨 (NaBH4) 과 이산화탄소의 환원을 이용한 바나듐 레독스 흐름전지용 탄소 촉매 개발)

  • Han, Manho;Kim, Hansung
    • Journal of the Korean Electrochemical Society
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    • v.21 no.1
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    • pp.1-5
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    • 2018
  • In this study, boron - doped carbon was prepared by reducing carbon dioxide ($CO_2$) at high temperature by using sodium borohydride ($NaBH_4$). The boron - doped carbon was coated on carbon felt and applied as an electrode for a vanadium redox battery cell. As a result of electrochemical performance evaluation, reversibility of carbon felt coated with boron doped carbon compared to pure carbon felt was improved by about 20% and charge transfer resistance was reduced by 60%. In the charge / discharge results, energy density and energy efficiency were improved by 21% and 12.4%, respectively. These results show that carbon produced by reduction of $CO_2$ can be used as electrode material for redox flow battery.

A DFT Study on CO2 Interaction with a BN Nano-Cage

  • Baei, Mohammad T.;Peyghan, Ali Ahmadi;Bagheri, Zargham
    • Bulletin of the Korean Chemical Society
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    • v.33 no.10
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    • pp.3338-3342
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    • 2012
  • Covalent functionalization of a $B_{12}N_{12}$ nano-cage with $CO_2$ molecule has been investigated using density functional theory in terms of energetic, geometric, and electronic property analyses. Results show that besides two physisorption configurations, $CO_2$ preferably tends to perform [2+2] addition on B-N bonds of the cluster which are shared between six-membered and four-membered rings, releasing energy of 14.99 kcal/mol for adsorption of the first $CO_2$ and of 15.45 kcal/mol for the second one (per each molecule). On the basis of calculated density of states, we have found that the electronic properties of the physisorbed $B_{12}N_{12}$ by $CO_2$ have not changed, while slight changes have been predicted in the functionalized cases. Present results might be helpful to provide an effective way to modify the $B_{12}N_{12}$ properties for further purifications and applications.

FUNCTIONAL PROPERTIES OF NATURAL CALCIUM FROM SEAWEEDS

  • Lawlor Susan
    • Proceedings of the Korean Society of Food Science and Nutrition Conference
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    • 2001.12a
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    • pp.126-133
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    • 2001
  • As dietary intakes levels of Calcium decrease below those recommended by health authorities the incidence of Osteoporosis is set to continue to rise. To address this issue it is becoming necessary to fortify regularly consumed foods such as cereals, biscuits etc. with ingredients such as AquaCal. AquaCal is a natural, organic source of calcium that is produced from calcified seaweed, Phymatolithon and Lithothamnion and can be utilised for Calcium and magnesium supplementation in a broad range of foods and beverages. AquaCal presents a great potential over other calcium sources because of its porous structure and it composition associating key minerals as calcium, magnesium and boron in addition to being neutral in taste in applications. Once consumed the efficacy of AquaCal must then be verified therefore a bioavailability a comparative feeding study to assess effects of AquaCal on bone density was carried out. There was no significant difference in bioavailability based on calcium absorption between AquaCal and Limestone however the weights of the femurs of the animals fed AquaCal did significantly increase over the group fed Limestone. As a natural and organic mineral AquaCal has many different fields of application.

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