Amount Of Boron Research Articles

Glycidol-functionalized macroporous polymer for boron removal from aqueous solution

This study describes two boron sorbents: P(GMA-co-TRIM)-EN-PG and P(GMA-co-TRIM)-TETA-PG. These absorbents were prepared by grafting glycidol onto P(GMA-co-TRIM) with different amounts of amino and imino groups. The structure was characterized using FT-IR, SEM and the water contact angle (WCA). The two adsorbents contain a large number of hydroxyl groups and are defined as nanomaterials. The adsorption of boron by the two adsorbents was investigated by determining the effects of pH, the initial boron concentration, adsorption time, ion competition and cycle life. Isothermal adsorption data were combined with the Langmuir adsorption isotherm model, and the adsorption kinetics were well fitted to the second-order kinetic model. The adsorption equilibrium was achieved within 60 min, and the maximum amounts of boron adsorbed were 29.22 mg/g and 23.25 mg/g, respectively. The presence of Na+, Mg2+, Ca2+, K+, Cl−, SO42− and NO3− ions had little effect on boron adsorption. After five consecutive adsorption-desorption cycles, the two adsorbents showed good reuse performance. These two promising adsorbents are useful for removing boron from aqueous solutions.

English

The aim of the experiment was to assess the effect of bio-stimulants of different composition (Asahi SL - based on three nitrophenol compounds, naturally occurring in plants, as active ingredients; Optisil – mineral growth stimulant containing 24 g L-1 of Fe and 200 g L-1 of SiO2; Kelpak SL – manufactured from Ecklonia maxima and containing auxins and cytokinins) on the content of macronutrients and micronutrients in cucumber fruits (Cucumis sativus L.) and on the fruit yield of the Akord F1 variety. With three replications, the field experiment was conducted in a completely randomised design on a private farm in Wolka LeA›na in Poland (N 52°11’59”, E 22°24’30”). The experiment was carried out in three growing seasons between 2015 and 2017. Three types of growth regulators and a cucumber variety were used as experimental factors. During the experiment, it was found that in response to bio-stimulants, fruit protein content and the yield significantly increased relative to control. The highest yield was noted after application of the bio-stimulant containing Fe and SiO2. Additionally, the above products applied to cucumber plants significantly increased magnesium content in the fruits but decreased the amount of sodium. Similarly, higher amounts of iron, manganese, and boron in relation to control were recorded, and in the case of Optysil the content of Zn and Co also increased. Key words: Cucumis sativus L., growth stimulators, macronutrients, micronutrients, protein.

Lithium and Boron in Calcified Tissues of Vicuna and Their Relation to Chronic Exposure by Water Ingestion in The Andean Lithium Triangle.

Vicuna is a wild, endangered species of Andean camelid living in the hyperarid Andean plateau. In the central part of the plateau, the Lithium Triangle defines a zone with lithium-rich salt pans. Brine pools naturally form within the salt pans, and the adaptation strategy of vicuna consists of drinking from brine pools. Together with reporting the first chemical data on vicuna bones and teeth, we analyzed lithium, boron, and arsenic in water and brines, with the aim of assessing their relation to chronic exposure by water ingestion. We collected and analyzed bones of vicuna specimens lying in an Andean salt pan, together with brine and water samples. Brine and water samples are highly saline and contain large amounts of lithium, boron, and arsenic. Lithium (13.50-40 mg kg-1 ) and boron (40-46.80 mg kg-1 ), but not arsenic, were found in the vicuna bones and teeth. Based on our results and on previously reported data on human tissues in the Andes, we conducted statistical assessments of the relationships between lithium and boron in body tissues and water samples, and discuss their environmental significance in the context of the Lithium Triangle. Environ Toxicol Chem 2019;39:200-209. © 2019 SETAC.

Femtosecond Pulsed Laser Deposition of Chromium Diboride-Rich Thin Films

Chromium borides are promising candidates for several structural applications including protective coatings for materials exposed to corrosive and abrasive environments. In this paper the pulsed laser deposition of chromium diboride-rich thin films has been carried out in vacuum by using a frequency doubled Nd:glass laser with a pulse duration of 250 fs. The films have been deposited at different substrate temperatures and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. Lastly, the film’s hardness has been studied by Vickers indentation technique. The results indicate that only the films deposited at a substrate temperature of 500 °C are crystalline and formed by chromium diboride, together with a certain amount of boron and chromium, which suggests that, as main mechanism, a process taking place on the surface from atoms and ions from the gas phase. This hypothesis has been confirmed by the study of the plasma produced by the ablation process.

Effects of rosin-aluminum sulfate treatment on the leachability, color stability, and decay resistance of wood treated with a boron-based preservative

This study evaluated the combined effects of rosin and aluminum sulfate (alum) on the leachability of boron, the color stability, and the decay resistance of poplar (Populus ussuriensis) wood treated with boron compounds. After leaching, the boron content in the leachates was analyzed via the azomethine-H method. Results showed the amount of boron released from the rosin-alum-boron solution treated samples was reduced by approximately 30% when compared to the samples treated with boric acid alone. All samples treated with rosin-alum-boron formulations exhibited greater color stability than that of the untreated controls after being exposed to natural weathering. The decay resistance of the treated wood blocks was measured via a soil-block culture. The results revealed that after being treated with the rosin-alum-boron formulations, the decay resistance of the leached wood was markedly improved. The average weight loss of the samples degraded by both fungi tested was less than 20%. Notably, scanning electron microscopy equipped with an energy dispersive X-ray analysis showed that the B element was still in the cell lumens of the leached and decayed wood blocks. This signified that the use of rosin combined with aluminum sulfate as a fixative agent may reduce boron leachability and could increase the usage of wood treated with boron preservatives.

Wear performance of selective laser melted Ti-6Al-4V alloy in situ modified with oxygen and boron

Titanium alloys have poor wear performance, with severe adhesive wear and three-body abrasion being dominant mechanisms. To extend the use of titanium to applications demanding better wear properties, modifications can be made to the alloys. This can include the addition of hard particulates or interstitial strengthening, by increasing the oxygen or nitrogen content. The metal additive manufacturing process of selective laser melting (SLM) has been shown to enable manufacture of these modified titanium alloys in situ. In this study, small amounts of boron and titanium dioxide powders were added to Ti-6Al-4V (Ti64) and processed using SLM. To compare wear performance of these modified materials, reciprocating pin on plate tests in brine solution were performed. Increased oxygen content increased the hardness of the material, which reduced wear. The presence of boron increased wear in the short term but reduced the long-term wear rate. Incorporating of oxygen and boron has been shown to improve the saline solution wear properties of Ti64 against silicon nitride.

An experimental study on the investigation of nuclear radiation shielding characteristics in iron-boron alloys

This study focused on the investigation of nuclear radiation shielding parameters of iron-boron alloys, which occupy an important place in powder metallurgy. Fe (100-x)B(x) alloys (where x: 1, 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20) were irradiated with Am-241, Ba-133 and Eu-152 radioactive sources which are emitted 0.0532, 0.0595, 0.0796, 0.0810, 0.1218, 0.2764, 0.3029, 0.3560, 0.3443, 0.3839, 0.7789 MeV photon energies. The photon intensities were measured by using an Ultra Ge detector. The mass attenuation coefficients (μρ) were acquired experimentally and then half value layers (HVL), the mean free paths (MFP), effective atomic numbers (Zeff) and effective electron densities (Nel) values were calculated by utilizing the μρ values. The outcomes also compared to theoretical values by employing WinXCOM. In addition, the Exposure (EBF) and Energy Absorption (EABF) Buildup Factors were computed at 0.015–15 MeV photon energies up to 40 mfp for Fe99B1 and Fe80B20. The results present that the Fe–B alloy including 20% boron own the highest HVL, MFP values than the others. It is demonstrated that the addition of boron to Fe doesn’t affect positively the photon shielding ability of the Fe–B alloys. However, when compared to the previously reported shield materials, they appear to be quite successful in the sense of gamma attenuation in the selected energy range. Besides, neutron dose transmission experiments were performed and the ΣR values were calculated. In contrast to gamma shielding properties, as the amount of boron increased in Fe–B alloys, their neutron reduction capacity increased.

Hexagonal boron nitride grown using high atomic boron emission during microwave plasma chemical vapor deposition

Boron nitride (BN) is a member of Group III nitrides and continues to spark interest among the scientific community for its mechanical properties, chemical inertness, thermal conductivity, and electrical insulating properties. In this study, microwave plasma chemical vapor deposition is used to synthesize BN on silicon substrates. Feed gas mixtures of H2, NH3, and B2H6 are used for a range of systematically varied power, pressure, and flow rate conditions. Plasma optical emission from atomic boron is shown to increase nonlinearly by nearly a factor of five with decreasing chamber pressure in the range from 100 to 10 Torr. Copious amounts of atomic boron in the plasma may be beneficial under some growth conditions for producing high hardness boron-rich nitrides, such as B13N2, B50N2, or B6N, which, to date, have only been synthesized under high pressure/high temperature conditions. Despite the higher atomic boron emission in the plasma at low pressure, BN coatings grown at 15 Torr result in hexagonal BN (B/N ratio of 1), regardless of the B2H6 flow rate used in the range of 0.6–3.0 sccm.

Boron in Heat‐Treatable Steels: A Review

The science and technology of boron addition to heat‐treatable steels are explained. The aim is to address the following: How to add boron to steel (i.e., the manufacturing aspects of boron addition to steel)? What precautions are necessary when alloying boron to steel, in terms of composition (mainly nitrogen, aluminum, and titanium contents), processing and heat treatment (i.e., material and process robustness and reproducibility for a consistent steel quality)? Where does boron go in steel (i.e., the state of boron, interstitial or substitutional solute, precipitate or a complex with other alloying elements; as well as the location of boron, i.e., dissolved as a solute in the grain or segregated at the grain boundary)? Which characterization methods are suitable for the detection of the very small amounts of boron (<30 wt ppm) in heat‐treatable steels? What does boron do in steel (i.e., its effect on hardenability and mechanical properties, specifically impact toughness)? How does it do and what it does (i.e., the physical mechanism by which it influences the properties)? How much boron is really required to achieve the desired properties in heat‐treatable steels (i.e., recommendations for the optimum boron content)?

Pulse Plating of Ni-W-B Coating and Study of Its Corrosion and Wear Resistance

The aim of the current study is to optimize some of the principal parameters to achieve smooth Ni-W-B alloys with high corrosion resistance and wear properties. The pulse plating method was used for preparing Ni-W-B coatings, and the effects of the pulse duty cycle and applied current density on the electrochemical and mechanical properties of the coatings were evaluated. Field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and the Vickers microhardness (HV) tester were applied to investigate the morphology, roughness and hardness of the prepared coatings. The composition and phases of coatings were analyzed by energy dispersive spectroscopy (EDS), an inductively coupled plasma-optical emission spectrometer (ICP-OES) and X-ray diffraction (XRD). For exploring the corrosion behavior of the coatings, the open circuit potential (OCP), potentiodynamic polarization (Tafel) and electrochemical impedance spectroscopy (EIS) were used. Wear behavior of coatings was studied with the pin-on-disk method. The coating grain size was increased from 17 up to 29 nm by raising the average current density from 10 to 70 mA/cm2 because of the decreasing boron content. At the pulse duty cycle of 20 pct, the high hardness of 905 HV was displayed at the current density of 10 mA/cm2, which contains the maximum amount of boron (12.9 at. pct). In addition, raising the current density (from 10 to 70 mA/cm2) and reducing the duty cycle from 80 down to 20 pct gave rise to the reduction of surface roughness and the addition of tungsten content from 29.3 to 40.4 wt pct in the matrix. These effects improve corrosion resistances of coatings so that at the pulse duty cycle of 20 pct, by increasing the average current density from 10 to 70 mA/cm2, the corrosion current density declines from 9.8 to 2.1 µA/cm2 and the charge transfer raises from 3.1 to 20.4 KΩ cm2. Improvement of wear resistance observed by raising the plating current density could be related to the smoother surface and less brittle nature of coatings. The coating wear resistance improves with increasing plating current density up to 70 mA/cm2, seen in the reduction of the wear weight loss (from 1.1 to 0.41 mg/cm2) and friction coefficient (from 0.71 to 0.42).

Enlargement of a Modular System-Synthesis and Characterization of an s-Triazine-Based Carboxylic Acid Ester Bearing a Galactopyranosyl Moiety and an Enormous Boron Load.

The amount of boron accumulated in tumor tissue plays an important role regarding the success of the boron neutron capture therapy (BNCT). In this article, we report a modular system, combining readily available starting materials, like glycine, 1,3,5-triazine and the well-known 9-mercapto-1,7-dicarba-closo-dodecaborane(12), as well as α-d-galactopyranose for increased hydrophilicity, with a novel boron-rich tris-meta-carboranyl thiol.

Effects of boron addition on microstructures and mechanical properties of Ti-6Al-4V manufactured by direct laser deposition

Large columnar grains with strong texture in direct laser deposited (DLDed) Ti-6Al-4V (Ti-64) is widely reported to cause issues like strong mechanical property anisotropy and poor tensile strength, which make this material unsuitable for many uses in the aerospace industry. In this study, a microstructure refinement investigation was carried out by adding various amounts of boron from 0.05 wt% to 1.0 wt%. The effects of boron additions, even with 0.05 wt%, are very strong on the microstructure refinement. The presence of large columnar grains was eliminated along with the α lath refinement, the grain boundary α elimination and the texture weakening. β reconstruction results showed that boron is very effective in the β grain refinement and the β texture weakening, which contributes to the transformed α lath refinement and the α texture weakening, respectively. Furthermore, the tensile strength of DLDed Ti-64 with different boron additions is improved. A good balance of the tensile strength and ductility, with considerably reduced anisotropy, was achieved by adding 0.05 wt% boron. A comprehensive understanding between the boron additions, microstructure refinement and tensile performance improvement was fully established, which could enable greater usage of DLDed Ti-64 in the aerospace industry.

BNCT induced immunomodulatory effects contribute to mammary tumor inhibition.

In the United States, breast cancer is one of the most common and the second leading cause of cancer-related death in women. Treatment modalities for mammary tumor are surgical removal of the tumor tissue followed by either chemotherapy or radiotherapy or both. Radiation therapy is a whole body irradiation regimen that suppresses the immune system leaving hosts susceptible to infection or secondary tumors. Boron neutron capture therapy (BNCT) in that regard is more selective, the cells that are mostly affected are those that are loaded with 109 or more 10B atoms. Previously, we have described that liposomal encapsulation of boron-rich compounds such as TAC and MAC deliver a high payload to the tumor tissue when injected intravenously. Here we report that liposome-mediated boron delivery to the tumor is inversely proportional to the size of the murine mammary (EMT-6) tumors. The plausible reason for the inverse ratio of boron and EMT-6 tumor size is the necrosis in these tumors, which is more prominent in the large tumors. The large tumors also have receding blood vessels contributing further to poor boron delivery to these tumors. We next report that the presence of boron in blood is essential for the effects of BNCT on EMT-6 tumor inhibition as direct injection of boron-rich liposomes did not provide any added advantage in inhibition of EMT-6 tumor in BALB/c mice following irradiation despite having a significantly higher amount of boron in the tumor tissue. BNCT reaction in PBMCs resulted in the modification of these cells to anti-tumor phenotype. In this study, we report the immunomodulatory effects of BNCT when boron-rich compounds are delivered systemically.

SrAl2O4: Eu+2, Dy+3 Nanoliflerin Faz Kararlılığı Üzerine Bor Katkısının Etkisi

In this study, three varied groups as pristine, europium and dysprosium doped SrAl2O4 and boron doped SrAl2O4:Eu2+, Dy3+ phosphorus materials were prepared. To see the effect of boron additive on phase stability of nanofibers, different ratios of boron were added. In the experimental studies, as process variables during the electrospinning method; the effect of the applied voltage, the distance between the syringe needle and collector plate were examined. The characterization of phosphorescence samples was carried out with DSC/TG, XRD and SEM. As a result of XRD analysis of the synthesized powders the structure was observed to be in monoclinic SrAl2O4 form in the pristine and Eu-Dy doped samples and turn into orthorhombic crystal-structured Sr4Al14O25 structure. Through examining the SEM photos of nanofibers, its observed that boron additive has a significant effect on nanofiber structure and with the increase in the boron amount, much order and much small-diameter nanofibers occur. Consequently, it is determined that boron additive has a significant effect on thermal, mineralogical and morphological properties of SrAl2O4: Eu, Dy structure.

On the origin of multilayered structure of W-B-C coatings prepared by non-reactive magnetron sputtering from a single segmented target

Multilayered coatings are routinely obtained in non-reactive processes employing multiple sources or in processes with a reactive gas. W-B-C coatings were sputter deposited in an industrial sputtering system in a non-reactive atmosphere onto substrates performing one- and two-axis rotations around a central cylindrical target composed of boron-carbide, tungsten and graphite ring-shaped segments. This study describes the unexpected multilayered structure of W-B-C coatings deposited by even the non-reactive sputtering of a single target. This multilayered structure exhibits a modulation of the chemical composition. While the tungsten content in a layer decreases, the amount of boron and carbon rises. The modulation period corresponds with the calculated thickness increment per one sample revolution around the central cathode. Experiments proved that the chemical composition of a coating and its deposition rate are very sensitive to the substrate position in the chamber. This was attributed to the different transport pathways of heavy (W) and light (C and B) atoms sputtered from the same target, but differently scattered by the working argon gas.

A novel Ni-based bulk metallic glass containing high amount of tungsten and boron

Glass forming ability (GFA) and thermal stability of (Ni51W31.6B17.4)100-xCox (x = 0–35) alloy system have been investigated. It is found that as the cobalt content is increased critical casting thicknesses improve significantly. Critical casting thickness of 20, 25 and 30 at. % cobalt alloys are determined as 0.5, 1, and 1 mm, respectively. However, further increase of cobalt content degrades the GFA. The Ni-based bulk metallic glasses discovered in this study are the first ones ever developed which contain more than 10 at. % boron. It is also determined that after annealing the fully amorphous samples above their first and second crystallization temperatures, nickel solid solution and CoWB phase precipitate. This is the first study where precipitation of ultra-hard CoWB phase in a bulk metallic glass is reported.

Effect of pH on Dimethylamine Borane Reduced Electroless Nickel Deposits on AISI/SAE 1045 Steel Surface

Electroless Ni–B coatings using DMAB-reduced plating baths at different pH conditions were formed on AISI/SAE 1045 carbon steel. Substrates were grit-blasted with alumina, generating a rough surface suitable for anchorage and nucleation of the coating. The surface of the substrates were examined at selected times of electroless treatment using scanning electron microscopy. The structure of the coating was studied by means of X-ray diffraction. A low-cost boron determination procedure was implemented in order to determine the amount of boron incorporated into the electroless coatings. Coatings nucleate faster at acid and neutral pH conditions; however, at the end of the plating process all coatings were adherent, with the typical morphology of Ni–B electroless coatings. Substrates slightly corroded inside the plating bath at acid pH condition. The amount of boron into the coatings was approximately 2.15, 2.14 and 1.10% (wt%) for the acid, neutral and alkaline pH plating baths, respectively.

Production of the Al–B Master Alloy by Aluminothermal Reduction of KBF4 and B2O3 in a Medium of the Molten Salt Flux

The process of obtaining the Al–B master alloy by the aluminothermal reduction of KBF4 and B2O3 using fluoride fluxes KF–AlF3 and KF–NaF–AlF3 at 983 and 1123 К, respectively, and chloride-fluoride fluxes KCl–NaCl–KF at Т = 1173–1223 К have been studied. All experiments were carried out under the same conditions: the stirring rate of molten mixture was 400 rpm, the duration of synthesis was 30 min. The maximum amount of boron (1.5%) in the Al–B alloy was obtained using KBF4 (3% per B) as a boron-containing raw material in the KF–AlF3 medium with a molar (cryolite) ratio (CR) of KF/AlF3, equal to 1.3, at Т = 983 К, while the boron extraction degree does not exceed 75%. The comparable results were obtained in the experiments with the KF–NaF–AlF3 flux (CR = 1.5) at T = 1123 K. However, with an increase in the concentration of the loaded boron, the degree of its extraction significantly decreased, which is associated with the decomposition at a higher temperature not only KBF4, but also NaBF4, which is less thermally stable; the latter is formed as a result of an exchange reaction in the melt. Therefore, the use of sodium salts as a component of the flux is not recommended. The Al–B master alloys obtained by reducing the KBF4 in the fluoride fluxes were solid solutions of B in Al containing the intermetallic compound AlB2. The lowest amount of boron in aluminum with the minimum extraction degree was obtained in experiments with B2O3 in the molten KF–AlF3 with CR = 1.5. Nevertheless, the results of scanning electron microscopy indicate a uniform distribution of B along the Al matrix and the absence of intermetallic compounds; however, a large amount of Al2O3 was found, which is the product of B2O3 reactions with both the liquid Al and the flux (KF–AlF3).

Role of Titanium, Carbon, Boron, and Zirconium in Carbide and Porosity Formation during Equiaxed Solidification of Nickel-Based Superalloys

This work analyses the effect of Ti in the MC carbide formation and also in the γ/γ´ eutectic promotion in two nickel-based alloys melted under vacuum conditions and solidified into ceramic molds. The role of boron, carbon and zirconium on the porosity level after solidification of both alloys was also investigated; since the alloys were vacuum melted, it is assumed that the observed porosity is due to micro-shrinkage. The chemical compositions for two alloys were: 20.2Cr-13.7Co-4.78Mo-1.19Al-0.69Ti-0.08C-2.34Fe for Alloy 1, and 20.5Cr-15.6Co5.03Mo-1.57Al-3.42Ti-0.15C-1.64Fe-0.076Zr-0.01%B for Alloy 2. Results showed a higher volume fraction of MC carbides and the γ/γ´ eutectic for the Alloy 2 with higher titanium content since this element is a carbide and γ/γ´ eutectic promoter. The porosity level in the Alloy 2, with higher amounts of carbon, boron and zirconium was considerably lower than that for the Alloy 1. These results are discussed in terms of different phenomena caused by the segregating effects of boron, carbon and zirconium towards the interdendritic regions and the formation of zirconium carbides that produce an expansion in volume when they are formed at the end of the solidification process.

Fabrication and phase evolution of Pr2Fe14C-based magnetic nanoparticles prepared by mechanochemical method

Abstract A facile mechanochemical method for fabricating Pr2Fe14C-based magnetic nanoparticles was reported. H and C were introduced by the decomposition of heptane during the high-energy ball milling process and reacted simultaneously with Pr3Fe14Bx (X = 0–0.2) alloy to form Fe7C3, PrH2+δ and α-Fe phases. Subsequently, the H2 released from the PrH2+δ and Pr2Fe14C-based magnetic materials were obtained during a fast vacuum annealing process. Compared with the traditional heat-treatment which involved time-consuming annealing and multi-steps cooling process, the zero holding time annealing with a fast heating rate will effectively reduce the energy consumption. Addition of small amounts of boron is demonstrated to promote the formation of Pr2Fe14C and reduce the quantity of magnetically soft Pr2Fe17 and α-Fe phases. The optimal magnetic properties of Mr = 5.9 kG, iHc = 19.8 kOe and (BH)max = 8.0 MGOe were obtained in Pr3Fe14B0.1 sample after ball-milling for 7 h and subsequently annealing. Microstructure morphology analysis of the as-annealed Pr3Fe14B0.1 powder reveals that the particles are almost rectangular shapes with an average size of about 117 nm. This bottom-up approach for fabrication of Pr2Fe14C nanoparticles may provide new thoughts for the preparation of high-performance magnetic materials.