• 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.

• Journal of Korea Foundry Society
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• v.9 no.5
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• pp.389-395
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• 1989

The effects of phosphorus and boron additions and isothermal holding time on the residual magnesium and sulfur content, and on the resultant graphite structure of cast irons were investigated. The effective recovery ratio of magnesium showed that adding phosphorus to the melt retarded the fading rate of magnesium but adding boron accelerated it. However, the residual sulfur content was found to be decreased with isothermal holding time at the begining, and then to be increased again with holding time by resulfurization. The Mg-Equivalent for producing compacted vermicular graphite structure was found to be increased with the addition of phosphorus, whereas to be decreased with the addition of boron.

• Journal of the Korean Ceramic Society
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• v.40 no.9
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• pp.832-836
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• 2003

Multi-layer ceramic composites were prepared by tape casting followed by hot pressing using silicon nitride layer with silicon nitride whiskers, silicon nitride layer with silicon carbide particles and boron nitride-alumina layer. The whiskers were aligned during the casting. As the whisker content of the silicon nitride layer was increased up to 10 wt％, the flexural strength of the multi-layer composite was increased. However, further increase of the whisker content in the layer resulted in a rapid decrease of the strength of the composite. The results suggest that the strength of multi-layer ceramic composite showing non-catastrophic failure behavior can be significantly improved by incorporating the aligned whiskers in the layers.

• Analytical Science and Technology
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• v.5 no.1
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• pp.127-134
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• 1992

Effects of boron addition on microstructure and phases of plasma are melted tungsten have been investigated by optical microscopy, scanning electron microscopy, Auger electron spectroscopy, X-ray diffractometer, measurements of grain size and hardness. The change in the microstructure upon boron addition was studied by optical microscopy. It was observed that the grain refinement was induced upon content within the limit of solubility. When the boron content was above the solubility limit, two phases of primary tungsten and eutectic structure were observed and confirmed by AES and XRD analysis. It was also shown that recrystallization temperature was increased and recrystallized grain size was reduced as boron content increased.

• Journal of Nutrition and Health
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• v.31 no.6
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• pp.1039-1048
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• 1998

It has been reported that boron may be beneficial for optimal calcium metabolism and, thus, optimal bone metabolism. Therefore, we designed a study to determine the effect of boron supplementation on Ca and bone metabolism in rats. The rats of 80-l40g body weight were given a control(0ug), 5$\mu\textrm{g}$, 10$\mu\textrm{g}$, 20$\mu\textrm{g}$, 40$\mu\textrm{g}$, or 80$\mu\textrm{g}$ boron supplement per Is diet for 4-weeks. The results are summarized as follows. There were no differences in total food intake and weight gain among the experimental groups. fecal Ca excretion, urinary Ca excretion, apparent Ca absorption, Ca retention, serum alkaline phosphatase activity, and urinary hydroxyproline were not affected by boron supplementation. There was no difference in serum creatinine. Whereas, urinary creatinine excretion was increased with increasing boron supplementation, and conse-quently creatinine clearance was increased with boron supplementation. No differences were found in length, weight, density, Ca content of femur and scapular. The findings suggest that boron supplementation was not effective in Ca and bone metabolism in growing rats fed normal Ca diet. (Korean J Nutrition 31(6) : 1039-1048, 1998)

• Membrane and Water Treatment
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• v.7 no.3
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• pp.193-207
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• 2016

Boron is one of the most problematic inorganic pollutants and is difficult to remove in water. Strict standards have been imposed for boron content in water because of their high toxicity at high concentrations. Technologies using membrane processes such as reverse osmosis (RO) and nanofiltration (NF) have increasingly been employed in many industrial sectors. In this work, removal of boron from model water solutions was investigated using polyamide reverse osmosis and nanofiltration membranes. RO-AG, RO-SG, NF-90 and NF-HL membranes were used to reduce the boron from model water at different operational conditions. To understand the boron separation properties a characterization of the four membranes was performed by determining the pure water permeability, surface charge and molecular weight cut-off. Thereafter, the effect of feed pressure, concentration, ionic strength, nature of ions in solution and pH on the rejection of boron were studied. The rejection of boron can reach up to 90% for the three membranes AG, SG and NF-90 at pH = 11. The Spiegler-Kedem model was applied to experimental results to determine the reflection coefficient of the membrane ${\sigma}$ and the solute permeability $P_s$.

• 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.

• Korean journal of applied entomology
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• v.21 no.2 s.51
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• pp.73-77
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• 1982

This experiment was carried out to study the effect of boron application on the physiological response and the outbreak of Granville wilt flue-cured tobacco. NC2326 and Coker 86(flue-cured tobacco) were transplante dand investigated in all field culture plots for this experiment. Elongation of shoots were retarded, and stem heights were shortened in all boron applied plots and the more boron applied, the greater these tendency was. The ratio of root branching and root discoloration, and contraction by Granville wilt were docreased markedly in boron plots. Amount of harvested loaves (yield) was increased greatly in 2 and 4kg plots of borax and boric acid per 10a, and the increasing tendency was greater in NC2326 variety than Coker 86. Phenol compounds content in harvested leaves were higher in boron applied plots than non-applied, and was higher in Coker 86, Granville wilt resistant variety, than NC2326. The more boron applied, the higher nicotine content in the harvested leaves was.

• Journal of Sericultural and Entomological Science
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• v.14 no.1
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• pp.1-7
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• 1972

Recently, young mulberry trees grown in the reclaimed hill land are frequently attacted by the die-bark and the buds of the trees developed poorly. In order to learn the cause of the injury mentioned above available boron content in the soils and the bark of young shoots have been analyzed. The results are as follow; Available boron content in the soil of the damaged mulberry fold was 0.3-0.20 ppm, against 0.39-49 ppm in that of healthy mulberry field, and boron in the bark of the damaged trees was 10.63-12.99 ppm, and 18.42-21.02 ppm in that of the healthy trees. The organic matter content and available boron content in soils showed a highly significant possitive correlation. The moisture content in percent in the soil of the damaged mulberry held was 11.16 and 14.22 in that of healthy mulberry field.

• Journal of Powder Materials
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• v.14 no.4
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• pp.272-276
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• 2007

P-type thermoelectric material $Si_{0.8}Ge_{0.2}$ was sintered by Hot Press process (HP) and the effect of boron ($0.25{\sim}2$ at%) addition on the thermoelectric properties were reported. To enhance the thermoelectric performances, the $Si_{0.8}Ge_{0.2}$, alloys were fabricated by mechanical alloying (MA) and HP. The carrier of p-type SiGe alloy was controlled by B-doping. The effect of sintering condition and thermoelectric properties were investigated. B-doped SiGe alloys exhibited positive seebeck coefficient. The electrical conductivity and thermal conductivity were increased at the small amount of boron content ($0.25{\sim}0.5$ at%). However, they were decreased over 0.5 at% boron content. As a result, the small addition of boron improved the Z value. The Z value of 0.5 at% B doped $Si_{0.8}Ge_{0.2}$ B alloy was $0.9{\times}10{-4}/K$, the highest value among the prepared alloys.