The role of di-boron diffusion in evolution of B diffusion profiles has been investigated. We find that boron pair (Bs – Bi) diffusion can become as important as boron-interstitial pair (Bs – Sii) diffusion when both boron concentration and annealing temperature are very high, leading to concentration-dependent B diffusion. Our simulated B diffusion profiles with dramatic shouldering are in exc...

Boron exhibits anomalous diffusion during the initial phases of ion implant annealing. Boron transient enhanced diffusion is characterized by enhanced tail diffusion coupled with an electrically inactive immobile peak. The immobile peak is due to clustering of boron in the presence of excess interstitials which also enhance boron diffusion in the tail region. We present a simple model for the f...

The effect of boron on heterocystous and nonheterocystous dinitrogen fixing Cyanobacteria was examined. The absence of boron in culture media inhibited growth and nitrogenase activity in Nodularia sp., Chlorogloeopsis sp., and Nostoc sp. cultures. Examinations of boron-deficient cultures showed changes in heterocyst morphology. However, cultures of nonheterocystous Cyanobacteria, Gloeothece sp....

Liquids condensing on solids can form a pattern known as ‘‘breath figures.’’ Here we report similar patterns for liquid boron oxide droplets formed by high temperature oxidation reaction of boron nitride. Boron oxide does not wet boron nitride, so the liquid B2O3 oxide forms small droplets. As oxidation proceeds at 12001C, the oxide created by reaction on the surface migrates to existing drople...

The effect of boron on nitrogenase activity has been studied. When cells were dependent on N(2) fixation, the lack of boron inhibited nitrogenase activity. However, under anaerobic conditions or in the presence of Na-dithionite this effect was not observed. Nitrogenase synthesis was not affected by boron deficiency. Similarly, the heterocyst number was not altered. Examination of boron-deficien...

Elemental boron was isolated in 1808. It typically occurs in nature as borates hydrated with varying amounts of water. Important compounds are boric acid and borax. Boron compounds are also used in the production of metals, enamels, and glasses. In trace amounts, boron is essential for the growth of many plants, and is found in animal and human tissues at low concentrations. Poisoning in humans...

Boron heteroatom distributions are shown to be significantly different in two closely related layered borosilicates synthesized with subtly different alkylammonium surfactant species. The complicated order and disorder near framework boron sites in both borosilicates were characterized at the molecular level by using a combination of multi-dimensional solid-state nuclear magnetic resonance (NMR...

plants uptake boron (b) from the soil solution, in which boron concentration is controlled by adsorption and desorption reactions on soil organic and inorganic colloids. considering the importance of aluminosilicate minerals in ion adsorption and desorption reactions in soil, in this research, b adsorption behavior on kaolinite was studied as a function of equilibrium concentration, ph, kaolini...

background: boron and gadolinium are among the nuclides that hold a unique property of being a neutron capture therapy agent. neutron beams have often a considerable portion of gamma rays with fast neutrons. gamma rays, as beam contaminants, can cause considerable damage to normal tissues even if such tissues do contain high boron concentrations. materials and methods: the modification of radio...

Female and male rats weighing about 170 g and 200 g, respectively, were fed diets (approximately 70 microg boron/kg) in a factorial arrangement with supplemental boron at 0 (deficient) and 3 (adequate) mg/kg and canola oil or palm oil at 75 g/kg of diet as variables. After 5 weeks, six females in each treatment were bred. Dams and pups continued on their respective dietary treatments through ge...