• Title/Summary/Keyword: boron

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Effect of Boron Levels on Two Desert Plant Species (두 사막식물(沙漠植物)에 미치는 Boron 의 영향)

  • Cha, Jong Whan
    • Korean Journal of Soil Science and Fertilizer
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    • v.6 no.2
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    • pp.137-140
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    • 1973
  • Two desert plant species were grown in solution culture with varying levels of boron. Both appeared to be very resistant to accumulation of large amounts of boron but F. dumosa accumulated moderately high amounts of it at levels of 10 or more ppm in the nutrient solution. Growth reduction was indicated for this species at 50 and 100 ppm boron in the nutrient solution. The high levels of boron resulted in decreased potassium levels in roots for this species. Growth seemed to increase for A. hymenelytra up to level of 20 ppm boron in the nutrient solution but boron content in leaves at this level was only 156ppm of dry weight. Higher levels did not further increase boron contents of leaves. The distribution of both of these species in the desert is probably related to their ability to accumulate small amounts of boron in the presence of large amounts of boron in the soil.

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Removal of boron in seawater by activated carbon adsoprtion (활성탄 흡착에 의한 해수중의 보론 제거)

  • Kim, Han-Seung;Kang, Joon-Seok;Kim, Byung-Ro
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.6
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    • pp.917-922
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    • 2011
  • Adsorption characteristics of boron on activated carbon was investigated in order to evaluate the use of activated carbon for the removal of boron in desalination processes using SWRO. Boron was removed ranging from 54~60% when the concentration of activated carbon was 1,000 mg/L in 6 hours under the initial boron concentration of 5 mg/L. The removal of boron increased by 20~22% with the increase of pH from 5 to 9. Organic matter had adverse effect on the adsorption of boron on activated carbon. Boron removal decreased by 10-12% when EDTA was added at 1 mg/L under 5 mg/L of boron and 200mg/L of activated carbon. In this results, activated carbon would be a good candidate for a pretreatment of desalination processes by SWRO from the view of mitigating the feed boron concentration to RO and meeting the effluent boron concentration without post-treatment after RO.

THE IMPLEMENTATION OF BORON TRANSPORT EQUATION INTO A REACTOR COMPONENT ANLAYSIS CODE (원자로 기기 열수력 해석 코드에서 붕소 수송 방정식의 구현)

  • Park, Ik Kyu;Lee, Seung Wook;Yoon, Han Young
    • Journal of computational fluids engineering
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    • v.18 no.4
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    • pp.53-60
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    • 2013
  • The boron transport model has been implemented into the CUPID code to simulate the boron transport phenomena of the PWR. The boron concentration conservation was confirmed through a simulation of a conceptual boron transport problem in which water with a constant inlet boron concentration injected into an inlet of the 2-dimensional vertical flow tube. The step wise boron transport problem showed that the numerical diffusion of the boron concentration can be reduced by the second order convection scheme. In order to assess the adaptability of the developed boron transport model to the realistic situation, the ROCOM test was simulated by using the CUPID implemented with the boron transportation.

Inhibition of Adventitious Root Growth in Boron-Deficient or Aluminum-Stressed Sunflower Cuttings

  • Hong, Jung-Hee;Go, Eun-Jung;Kim, Tae-Yun
    • Journal of Environmental Science International
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    • v.12 no.11
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    • pp.1189-1196
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    • 2003
  • The effect of boron and aluminum on the development of adventitious roots was studied in sunflower cuttings. Three-day-old seedlings were de-rooted and grown in nutrient solutions with or without boron and supplemented with different concentrations (from 50 to 700 ${\mu}$M) of aluminum. The number and length of the adventitious roots and proline content in adventitious roots in response to insufficient boron and aluminum stress were determined periodically. The micronutrient boron caused the development of numerous roots in the lower parts of the hypocotyl. A dose-response of boron-induced rooting yielded an optimum concentration of 0.1 mM boron. In the absence of boron, in the majority of the adventitious roots, a significant inhibition was observed with or without aluminum, indicating that the most apparent symptom of boron deficiency is the cessation of root growth. Increasing concentrations of aluminum caused progressive inhibition of growth and rooting of the hypocotyls, and a parallel increase in proline levels of adventitious roots. Supplemental boron ameliorated the inhibitory effect of aluminum, suggesting that aluminum could inhibit root growth by inducing boron deficiency. Ascorbate added to medium in the absence of boron improved root growth and induced a significant decrease in proline levels. These findings suggest that adventitious root growth inhibition resulting from either boron deficiency or aluminum toxicity may be a result of impaired ascorbate metabolism.

Improving the dielectric reliability using boron doping on solution-processed aluminum oxide

  • Kim, Hyunwoo;Lee, Nayoung;Choi, Byoungdeog
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.411.1-411.1
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    • 2016
  • In this study, we examined the effects of boron doping on the dielectric reliability of solution processed aluminum oxide ($Al_2O_3$). When boron is doped in aluminum oxide, the hysteresis reliability is improved from 0.5 to 0.4 V in comparison with the undoped aluminum oxide. And the accumulation capacitance is increased when boron was doped, which implying the reduction of the thickness of dielectric film. The improved dielectric reliability of boron-doped aluminum oxide is originated from the small ionic radius of boron ion and the stronger bonding strength between boron and oxygen ions than that of between aluminum and oxygen ions. Strong boron-oxygen ion bonding in aluminum oxide results dielectric film denser and thinner. The leakage current of aluminum oxide also reduced when boron was doped in aluminum oxide.

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A STUDY ON THE BEHAVIOR OF BORON DISTRIBUTION IN LOW CARBON STEEL BY PARTICLE TRACKING AUTORADIOGRAPHY

  • Mun, Dong-Jun;Shin, Eun-Joo;Koo, Yang-Mo
    • Nuclear Engineering and Technology
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    • v.43 no.1
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    • pp.1-6
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    • 2011
  • The behavior of the non-equilibrium grain boundary segregation of boron in low carbon steel was studied through a particle tracking autoradiography. The behavior of the non-equilibrium grain boundary segregation of boron during continuous cooling was compared with the isothermal kinetics of the non-equilibrium grain boundary segregation of boron at the holding temperature using an effective time method. On the basis of the experiments, the cooling rate dependence of the non-equilibrium segregation of boron was explained using the time dependence of the non-equilibrium segregation of boron in low carbon steel. The experimental observations for the cooling rate dependence of the grain boundary segregation of boron are in good agreement with the time dependence of the grain boundary segregation of boron. The mechanisms of the non-equilibrium segregation of boron during cooling in low carbon steel are also discussed.

Preliminary research on the development of boron neutron capture therapy drugs

  • Soyeon Kim;Ji-ung Yang;Kyo Chul Lee;Jung Young Kim;Yong Jin Lee;Ji-Ae Park
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.7 no.1
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    • pp.3-10
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    • 2021
  • For successful boron neutron caputre therapy, it is essential to develop a boron drug with a selective accumulation capacity for tumors. In particular, in order to apply boron neutron caputre therapy to brain tumors, drugs with good blood-brain barrier penetration are required. In this study, two low-molecular-weight boron compounds were introduced as brain tumor boron neutron caputre therapy drugs, and their physical and biological efficacy were evaluated. Among them, B2 showed good blood-brain barrier permeability and a high brain/blood ratio. From these results, it is expected that B2 can be used as a useful boron drug for boron neutron caputre therapy in brain tumors.

Effects of Boron Supplementation to Diets Deficient in Calcium and Phosphorus on Performance with Some Serum, Bone and Fecal Characteristics of Broiler Chickens

  • Bozkurt, Mehmet;Kucukyilmaz, Kamil;Catli, Abdullah Ugur;Cinar, Mustafa;Cabuk, Metin;Bintas, Erol
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.2
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    • pp.248-255
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    • 2012
  • Three levels of boron (0, 30, 60 ppm) were supplemented in practical corn-soybean based starter and grower diets, containing either adequate or inadequate Ca or P. A total of 1,800, 1-day-old sexed broiler chicks were assigned to six dietary treatments and fed with the experimental diets for 42 days. Boron improved the overall feed conversion ratio, but increased body weight only at 21 days of age (p<0.01). Boron decreased feed intake in the case of feeding on a diet deficient in Ca and P, and tended to increase feed intake when birds received a diet adequate in Ca and P, signifying significant boron by Ca-P interaction (p<0.01). Mortality was not influenced by boron (p>0.05). Dietary Ca and P deprivation reduced body weight and feed consumption significantly, but did not influence the feed conversion ratio and mortality (p>0.05). Serum Ca level, ALP and ALT activities were not influenced either by dietary Ca and P deficiency or boron supplementation. Serum P content increased with respect to boron at 30 ppm. Bone breakage strength was not affected by dietary variables. Tibia ash, Ca and P were increased in response to the supplementation diet with 30 ppm boron, whereas 60 ppm showed no effect in most cases. Accordingly, the dietary boron supplementation of 30 ppm significantly decreased fecal Ca and P excretion, while there was a numerical decline in the 60 ppm boron as compared to the 0 ppm boron group. Data presented herein indicated that boron, either at the 30 ppm or 60 ppm supplementation level, was effective in conversion of feed to body weight, whereas only boron at 30 ppm contributed to the mineralization of bone thereby augmenting more Ca and P while excreting less through faeces.

Boron Analysis in High Carbon Graphitized Steel using Neutron Autoradiography (Neutron Radiography를 이용한 고탄소흑연강에서 붕소 분석)

  • U, Gi-Do;Yang, Chang-Ho;Park, Hui-Chan;Lee, Chang-Hui;Sim, Cheol-Mu;Jang, Jin-Seong;Kim, Hyeon-Gyeong
    • Korean Journal of Materials Research
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    • v.11 no.12
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    • pp.1074-1079
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    • 2001
  • To study the distribution of boron and the boron effect for nucleation of graphite in high carbon steel, neutron induced autoradiography method is used. High carbon steel is easy to make the graphitization by addition of boron. It is easy to analysis of boron distribution using neutron radiography with neutron fluence of $1.9$\times${\times}10^{13}/cm^2$in the boron added high carbon steel. By the neutron induced autoradiography technique, it was found that the distribution of boron depended on boron content, graphitiging temperature and time. And by the analysis of secondary ion mass spectroscopy (SIMS) and electron probe micro analysis (EPMA), boron or boride were acted at nucleation site of graphite in high carbon steel.

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Influence of B Content on Properties of Ni-B Electrodeposit (전기도금법에 의해 생성된 Ni-B 합금도금층의 물성에 미치는 B 함량의 영향)

  • 이규환;장도일;권식철
    • Journal of the Korean institute of surface engineering
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    • v.37 no.4
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    • pp.208-214
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    • 2004
  • The influence of the boron content on the various properties of Ni-B alloy films produced by electrodeposition was investigated. The considerable reduction in grain size was observed with increasing boron content. The internal stress was tensile and increased linearly with increasing boron content. Hardness increased up to $750H_{v}$ at 2 at% boron and then kept the value to 11 at% boron for as-plated Ni-B coatings. The hardness of Ni-B films increased up to $1,250H_{v}$ due to the intermetallic$ Ni_3$B precipitation by the heat treatment, and maximum hardness of each coating increases with boron content. Wear resistance decreased with increasing the boron content because of high friction coefficient and brittle fracture of film which has higher content of boron.