Role Of Boron Research Articles

Effect of Boron on the Solidification Characteristics and Constitutive Equation of S31254 Superaustenitic Stainless Steel

Solidification structure and segregation behavior of S31254 superaustenitic stainless steel ingot containing 0 wt% B and 0.005 wt% B are investigated. The results show that serious element segregation and massive eutectics are present in the center of the ingot. By contrast, the addition of boron reduces the secondary dendrite spacing, the degree of elemental segregation, and the σ phase. Further, the effect of boron on the solidification process is studied by using the high‐temperature confocal laser scanning microscope and combined with Thermo‐Calc thermodynamic simulation results. The results show that boron can widen the solidification temperature range and greatly retard the matrix solidification. The role of boron in refining dendrite structure and inhibiting precipitation is further confirmed. The effect of boron on the constitutive equation of S31254 superaustenitic stainless steel has also been researched through isothermal compression testing in the temperature range of 950–1200 °C and strain rate range of 0.01–10 s−1. The activation energy of the boron‐free and boron‐containing S31254 superaustenitic stainless steels based on the constitutive equation are 427.77 and 495.80 kJ mol−1, respectively. Processing maps indicate that the instability domain is significantly reduced and the hot ductility is improved after the addition of B.

Understanding the role of boron in plant adaptation to soil salinity.

Soil salinity is a major environmental constraint affecting the sustainability and profitability of agricultural production systems. Salinity stress tolerance has been present in wild crop relatives but then lost, or significantly weakened, during their domestication. Given the genetic and physiological complexity of salinity tolerance traits, agronomical solutions may be a suitable alternative to crop breeding for improved salinity stress tolerance. One of them is optimizing fertilization practices to assist plants in dealing with elevated salt levels in the soil. In this review, we analyse the causal relationship between the availability of boron (an essential metalloid micronutrient) and plant's adaptive responses to salinity stress at the whole-plant, cellular, and molecular levels, and a possibility of using boron for salt stress mitigation. The topics covered include the impact of salinity and the role of boron in cell wall remodelling, plasma membrane integrity, hormonal signalling, and operation of various membrane transporters mediating plant ionic and water homeostasis. Of specific interest is the role of boron in the regulation of H+-ATPase activity whose operation is essential for the control of a broad range of voltage-gated ion channels. The complex relationship between boron availability and expression patterns and the operation of aquaporins is also discussed.

Role of boron and its interaction with other elements in plants.

Boron (B) is an essential microelement for plants, and its deficiency can lead to impaired development and function. Around 50% of arable land in the world is acidic, and low pH in the soil solution decreases availability of several essential mineral elements, including B, magnesium (Mg), calcium (Ca), and potassium (K). Plants take up soil B in the form of boric acid (H3BO3) in acidic soil or tetrahydroxy borate [B(OH)4]- at neutral or alkaline pH. Boron can participate directly or indirectly in plant metabolism, including in the synthesis of the cell wall and plasma membrane, in carbohydrate and protein metabolism, and in the formation of ribonucleic acid (RNA). In addition, B interacts with other nutrients such as Ca, nitrogen (N), phosphorus (P), K, and zinc (Zn). In this review, we discuss the mechanisms of B uptake, absorption, and accumulation and its interactions with other elements, and how it contributes to the adaptation of plants to different environmental conditions. We also discuss potential B-mediated networks at the physiological and molecular levels involved in plant growth and development.

Effect of ZrB2 on promoting the phase transformation mechanism of Si3N4-based ceramics at low temperature

In this study, the mechanism of the effect of ZrB2 on phase transformation of Si3N4 at a low temperature and the influence of its content on Si3N4-based ceramics were investigated. Previous study has shown that oxide impurities, i.e., B2O3 and ZrO2 on ZrB2 particles, alone cannot contribute to phase transformation of Si3N4 at a low temperature. But, the introduction of 0.5 vol% ZrB2 into Si3N4 ceramics can promote the α-β phase transformation of Si3N4, which is confirmed to be the role of boron by comparison of the experimental results obtained from the addition of 0.5 vol% Zr and 0.5 vol% B. Increasing the ZrB2 content from 0 vol% to 2.5 vol% intensifies the α-β phase transformation while decreasing the α phase content of Si3N4-based ceramics, accompanied by a slight grain growth, leading to a decrease in hardness. At the same time, aspect ratio and the quantities of elongated grains per square micron increase, and thus the fracture toughness increases significantly. However, when the content of ZrB2 increases to 5 vol%, the Si3N4-based ceramics not only have a substantial decrease in hardness, but also the fracture toughness fails to be effectively improved due to high porosity and the decrease in aspect ratio and the quantity of elongated grains per square micron. The current study demonstrates that the dense Si3N4-based ceramics with high hardness and toughness (hardness ∼19.9 ± 0.2 GPa, toughness ∼6.27 ± 0.19 MPa m1/2) can be prepared successfully at 1600 °C by introducing 0.5 vol% ZrB2.

Role of boron and its detoxification system in trifoliate seedlings (Poncirus trifoliate (L) Raf.) response to H+-toxicity: Antioxidant responses, stress physiological indexes, and essential element contents

Boron (B) deficiency and H+toxicity are two prominent factors that severly restrict trifoliate seedlings growth in acid soil. Exogenous B can support to mitigate the harm of H+toxicity, however, research on the protective mechanism and the impact of physiological processes in citrus is limited. To fill the above gaps, the current study was performed on trifoliate rootstock using two pH levels (pH 4 and pH 6) and various B treatments (B0, B1, B2, B3, B4) to identify how B confers tolerance to H+ toxicity in trifoliate rootstock. Our results illustrate that H+toxicity suppressed plant growth, specifically the root elongation (27.22%). Boron capitalized the positive effect on plant growth as soon as it is applied to culture medium. The supply of B increased the activity of antioxidant enzymes and the content of antioxidant substances in root of trifoliate seedlings under H+ toxicity to scavenging the massively accumulated reactive oxygen species (ROS), reducing the malondialdehyde (MDA) content (12.07%-53.45%) and promoting root development. Meanwhile, the higher levels of osmolytes after B supply in root were better for maintaining water in cell and resisting H+ toxicity. Furthermore, B supplementation improved nutrients content including macro and microelements in root, especially the elements constituting superoxide dismutase (SOD), which in turn activated the antioxidant enzymes system. In conclusion, the ameliorative effects of B to H+toxicity in trifoliate seedlings was based on B homeostasis, improved antioxidant defense system, and then nutrient content. These findings provide a new insight into the regulation of H+toxicity tolerance of citrus by B fertilizer application in acid soils.

The Role of Boron in Low Copper Spheroidal Graphite Irons

The effects of boron at concentrations ranging from 5 to 525 ppm in low copper spheroidal graphite iron (SGI) has been studied. At 130 to 140 ppm, no particular effect of boron was observed on the size distributions, number densities, or morphologies of the microparticle populations in the material. Neither was there observed any effects on the size distributions or number densities of graphite nodules. However, boron was observed to lead to a rough surface morphology of the graphite nodules at concentrations as small as 24 ppm. Intercellular carbides were found to form in alloys containing more than 70 ppm boron. Additionally, the graphite shape began to degenerate in alloys with more than 300 ppm of boron. Mass spectrometry analyses revealed these carbides contain relatively high amounts of boron. In an alloy containing 74 ppm boron, it was inferred by using electron backscatter diffraction that these were of the type {{hbox {M}}_{23}({hbox {C}},{hbox {B}})_{6}} borocarbides, where M = Fe, Mn, V, or a combination of them. Mass spectrometry analyses also revealed elevated concentrations of boron in the surface layers of the graphite nodules.

Boron boosted Fe3O4 activated peracetic acid for removing sulfamethazine: Role of boron and mechanism

BackgroundNowadays, antibiotic pollution is increasingly serious and posing a huge threat to ecology and human health. Therefore, it is vital to find effective approaches to remove antibiotics. MethodsIn this study, boron (B) was adopted to accelerate the surface and solution Fe2+ recycle in Fe3O4/peracetic acid (PAA) system, which showed excellent performance for antibiotics removal. Significant findingsAccording the XPS analysis and experiments detection, both recycle of surface and solution Fe2+ could be enhanced in the presence of boron in Fe3O4/PAA system. 74.0% sulfamethazine (SMT) could be removed within 60 min in Fe3O4/PAA system while 93.4% could be removed within only 20 min in B/Fe3O4/PAA system and the value of k in B/Fe3O4/PAA system (0.136 min−1) was also much higher than that in Fe3O4/PAA system (0.028 min−1). The effect of boron, Fe3O4, PAA dosage and initial pH on removing SMT in Fe3O4/PAA system were also conducted. Quenching experiments and EPR experiments demonstrated that ·OH, organic radicals (R-O·) and Fe(IV) exhibited 63.1%, 17.3%, and 16.2% role in removing SMT, respectively. Possible SMT degradation pathway and the toxicity of transformation products were analyzed. B/Fe3O4/PAA exhibited superior resistance to inorganic ions and nature organic matters, good recycle ability, excellent adaptability to various pollutants, and efficient performance for antibiotics removal in natural fresh water.

Role of Boron in Assisting the Super-Enhancement of Emissions from Carbon-Implanted Silicon.

The super enhancement of silicon band edge luminescence when co-implanted with boron and carbon is reported. The role of boron in the band edge emissions in silicon was investigated by deliberately introducing defects into the lattice structures. We aimed to increase the light emission intensity from silicon by boron implantation, leading to the formation of dislocation loops between the lattice structures. The silicon samples were doped with a high concentration of carbon before boron implantation and then annealed at a high temperature to activate the dopants into substitutional lattice sites. Photoluminescence (PL) measurements were performed to observe the emissions at the near-infrared region. The temperatures were varied from 10 K to 100 K to study the effect of temperature on the peak luminescence intensity. Two main peaks could be seen at ~1112 and 1170 nm by observing the PL spectra. The intensities shown by both peaks in the samples incorporated with boron are significantly higher than those in pristine silicon samples, and the highest intensity in the former was 600 times greater than that in the latter. Transmission electron microscopy (TEM) was used to study the structure of post-implant and post-anneal silicon sample. The dislocation loops were observed in the sample. Through a technique compatible with mature silicon processing technology, the results of this study will greatly contribute to the development of all Si-based photonic systems and quantum technologies.

Boron migration during amorphous to crystalline transformation in CoFeB/MgO multilayers: A reflectivity study

Migration of boron in CoFeB/MgO multilayer during amorphous to crystalline transformation in CoFeB has been studied using Polarized Neutron Reflectivity (PNR) and anomalous Soft X-ray Reflectivity (SXR). PNR gives information about the possible redistribution of B in the multilayer during thermal annealing, as well as about the variation in the average magnetic moment. Sensitivity of the soft X-ray reflectivity to the movement of boron is enhanced by doing a series of measurements with X-ray energy spanning across the K absorption edge of B. Both the PNR and anomalous SXR results clearly suggest that upon thermal annealing, boron prefers to move away from the MgO/CoFeB interfaces, and forms a layer of boride in the middle of the magnetic layer. These results are important in view of the existing ambiguity regarding the role of boron in CoFeB/MgO based magnetic tunnel junctions.

Boron promoted Fe3+/peracetic acid process for sulfamethazine degradation: Efficiency, role of boron, and identification of the reactive species

In this work, boron (B) was used to promote Fe3+/peracetic acid (Fe3+/PAA) for the degradation of sulfamethazine (SMT). An SMT degradation efficiency of 9.1% was observed in the Fe3+/PAA system over 60 min, which was significantly increased to 99.3% in the B/Fe3+/PAA system over 10 min. The B/Fe3+/PAA process also exhibited superior resistance to natural substances, excellent adaptability to different harmful substances, and good removal of antibiotics in natural fresh water samples. The mechanism of action of boron for Fe3+ reduction was determined using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, density functional theory (DFT) calculations, and electrochemical tests. The dominant role of •OH was confirmed using quenching experiments, electron spin resonance (EPR) spectroscopy, and quantitative tests. Organic radicals (R-O•) and Fe(IV) also significantly contribute to the removal of SMT. DFT calculations on the reaction between Fe2+ and the PAA were conducted to further determine the contribution from •OH, R-O•, and Fe(IV) from the perspective of thermodynamics and the reaction pathways. Different boron dosages, Fe3+ dosages, and initial pH values were also investigated in the B/Fe3+/PAA system to study their effect of SMT removal and the production of the reactive species. Fe(IV) production determined the kR-O•+Fe(IV) value suggesting that Fe(IV) may play a more important role than R-O•. A comparison of the results with other processes has also proved that the procedure described in this study (B/Fe3+/PAA) is an effective method for the degradation of antibiotics.

Elucidating the impact of boron fertilization on soil physico-chemical and biological entities under cauliflower-cowpea-okra cropping system in an Eastern Himalayan acidic Inceptisol.

Information on the role of boron (B) on soil physico-chemical and biological entities is scarce, and the precise mechanism in soil is still obscure. Present field investigation aimed to assessing the implication of direct and residual effect of graded levels of applied-B on soil biological entities and its concomitant impact on crop productivity. The treatments comprised of five graded levels of B with four replications. To assess the direct effect of B-fertilization, cauliflower was grown as a test crop wherein, B-fertilization was done every year. For assessment of succeeding residual effects of B-fertilization, cowpea and okra were grown as test crops and, B-fertilization was phased out in both crops. The 100% recommended dose of NPK (RDF) along with FYM was uniformly applied to all crops under CCOCS. Results indicated that the direct effect of B had the edge over residual effect of B in affecting soil physico-chemical and biological entities under CCOCS. Amongst the graded levels of B, application of the highest B level (2 kg ha-1) was most prominent in augmenting microbiological pools in soil at different crop growth stages. The order of B treatments in respect of MBC, MBN, and soil respiration at different crop growth stages was 2.0 kg B ha-1 > 1.5 kg B ha-1 > 1.0 kg B ha-1 > 0.5 kg B ha-1 > 0 kg B ha-1, respectively. Moreover, maximum recoveries of potentially mineralizable-C (PMC) and potentially mineralizable-N (PMN) were noticed under 2 kg B ha-1. Analogous trend was recorded in soil microbial populations at different crop growth stages. Similarly, escalating B levels up to 2 kg B ha-1 exhibited significantly greater soil enzymatic activities viz., arylsulphatase (AS), dehydrogenase (DH), fluorescein diacetate (FDA) and phosphomonoesterase (PMA), except urease enzyme (UE) which showed an antagonistic effect of applied-B in soil. Greater geometric mean enzyme activity (GMEA) and soil functional diversity index were recorded under 2 kg B ha-1 in CCOCS, at all crop growth stages over control. The inclusive results indicated that different soil physico-chemical and biological properties CCOCS can be invariably improved by the application of graded levels of B up to 2 kg B ha-1 in an acid Inceptisol.

Fe3+/Fe2+ cycle promoted peroxymonosulfate activation with addition of boron for sulfamethazine degradation: Efficiency and the role of boron

Boron was used as an environmentally friendly and efficient reductant to accelerate the recycle of Fe2+ enhancing peroxymonosulfate (PMS) activation for sulfamethazine (SMT) degradation. The SMT removal was only 28.1% within 30 min in Fe2+/PMS system while SMT removal could reach to 98.9% within only 3 min in Boron/Fe2+/PMS (B/Fe2+/PMS). Electron paramagnetic resonance spectroscopy (EPR) tests, quantitative detection and radical quenching experiments illustrated that OH and SO4− played important role and Fe(IV), 1O2 and O2− also participated in SMT removal. The addition of boron could enhance the role of OH and SO4− in SMT removal in Fe2+/PMS system. X-ray photoelectron spectroscopy (XPS), electrochemical tests and density functional theory (DFT) calculation were conducted to confirm the mechanism of boron for accelerating the recycle of Fe2+. Possible SMT degradation pathway was proposed. B/Fe2+/PMS process could efficiently remove SMT at low Fe2+ dosage and neutral pH. B/Fe2+/PMS system also exhibited a superior resistance to inorganic ions and nature organic matters. Moreover, B/Fe2+/PMS system had good applicability to different pollutants, excellent reusability for antibiotics removal, and efficient performance for removing antibiotics in nature fresh water. The results compared with others’ works also demonstrated the present study process was a promising strategy for antibiotics removal.

Boron segregation and creep in ultra-fine grained tempered martensite ferritic steels

Abstract The creep strength of ultra-fine grained tempered martensite ferritic steels with 9 to 12 wt.% chromium is significantly increased when small amounts of boron (in the 100 wt-ppm regime) are added. In the present note, experimental evidence from the literature is reviewed and previous explanations for the role of boron are summarized. The explanation for the effect of boron on creep strength must leave space for the simultaneous effect of boron on ductility. A scenario is suggested where boron segregates to micrograin boundaries which often have subgrain-boundary character. Boron can decrease the subgrain-boundary energy, decrease the velocity of subgrain-boundary migration, hinder knitting reactions between free dislocations and subgrain-boundaries and thus contribute to creep strength. This decrease of intensity of interface plasticity contributes to a decrease in ductility. Boron may moreover decrease the strength of the interface and thus promote brittleness. Further work is required to fully account for the role of boron on the mechanical properties of tempered martensite ferritic steels.

Effects of boron addition on the microstructure and creep properties of a Ni-Fe-based superalloy weld metal alloy

The role of boron in the creep properties and grain boundary characteristics in a new Ni-Fe-based weld metal suitable for advanced ultra-supercritical (A-USC) coal-fired power plant applications has been investigated. Ni-Fe-based filler wires without boron and boron-doped (50 ppm wt% boron) were prepared for this study. Boron-doped weld metals exhibited longer rupture lives and lower steady creep rates during the creep rupture tests at 750 °C / 380 MPa and 750 °C / 210 MPa. This study explains the improvement mechanism of boron on creep resistance from the perspective of the effect of boron on M23C6. Boron increased the nucleation rate of M23C6 and participated in the formation of M23(C, B)6 type boron-carbides. After creep deformation, boron still existed stably in the M23(C, B)6. The higher density of discrete M23C6 particles due to boron addition could restrain grain boundary crack propagation and grain boundary sliding, and thereby improve the creep fracture resistance of the GH984G weld metal at 750 °C / (380/ 210 MPa).

Micronutrients and plant growth regulators affecting the yield and quality of fruit crops: A review

The application of micronutrients and plant growth regulators has a greater impact on enhancing plant productive efficiency by altering various aspects of horticultural attributes like a biometric response, fruiting potential, and qualitative parameters. All metabolic and cellular processes of fruit crops are influenced by micronutrients. The role of boron and zinc are well-known for nitrogen metabolism, cell division, and hormonal regulation which ultimately end with proliferation in flowering and fruiting by increasing fruit set and reducing fruit drop. The role of plant growth regulators (PGR) in plants in changing or normalizing the physiological cycle to create better plant health is well known. Hence, the combination of both these growth-promoting substances (micronutrients and PGR) in an optimum amount can positively and significantly influence the physiological activities of the plant. However, the literature regarding the combined effect of micronutrients and PGR on fruit crops is very limited. So this review paper focuses on the combined effect of these plant bio-stimulants, showcasing their remarkable role in fruit production.

The role of boron in prevention of osteoarticular diseases and its distribution in the Republic of Moldova

Introduction. Boron is a trace mineral that is supposed to be essential for human health. Organic plant based boron compounds are highly bioavailable for humans and can positively influence minerals such as calcium, phosphorus, magnesium and act in synergy with vitamin D, which are beneficial for osteoarticular health. Material and methods. We made an analysis of 126 bibliographic sources and mapped the Republic of Moldova to the content of boron in deep water and to the adults’ prevalence of rheumatoid arthritis and inflammatory polyarthropathy. Results. Boron is important for osteogenesis and its deficiency can lead to impaired growth and abnormal bones development. It supports bone health in postmenopausal women by reducing urinary loss of the minerals such as calcium, magnesium and phosphorus, which are essential for bone building. In countries where soil was depleted of boron and daily intake of this mineral was 1 mg or lower, the incidence of arthritis was between 20 and 70%. In Moldova, in the regions where boron concentration in deep drinking water were low (0.28 mg/L in well water and 0.51 mg/L in artesian well water) in Soroca in 2019, the prevalence with the rheumatoid arthritis and inflammatory polyarthropathy were high (51.6 per 10000 inhabitants) with one exception, UTA Gagauzia (35.1 per 10000 inhabitants), where we found a high boron concentration in deep drinking water (2.05 mg/L in well water and 2.2 mg/L in artesian well water) in 2015. Conclusions. Boron can affect bone metabolism. In regions where boron concentration in deep drinking water is low, the osteoarticular morbidity can be higher with the exception of UTA Gagauzia, where we suppose that dietary pattern can be a cause of these results. In the future we will study eating habits in this region and a clearer conclusion will be made.

Boron Isotope Analysis Reveals Borate Selectivity in Seaweeds.

The role of boron in terrestrial plant physiology is diverse and increasingly well understood, but its role in marine aquatic eukaryotes is less clear. Our research reveals a distinctive and large offset in boron isotopes from seawater, irrespective of seaweed type or season. We show that the offset is consistent with the incorporation of borate from seawater. Boron is a known micronutrient in plants but very few studies have used boron isotopes to investigate boron's role in plant physiology. Seaweed, as the most primitive multicellular plant, has an important role in investigating wider plant adaptations that use boron to meet functional needs. Furthermore, seaweed and other plants are a key base nutrient provider in food webs, supplying boron to consumers and playing a critical role in boron environmental cycling.

On the role of boron, carbon and zirconium on hot cracking and creep resistance of an additively manufactured polycrystalline superalloy

We investigate the hot cracking susceptibility and creep resistance of a nickel-based superalloy with three different contents of boron, carbon and zirconium fabricated by laser powder bed fusion. Crack-free and creep resistant components are achieved for the alloy version with boron, carbon and no zirconium. We then rationalize this result by evaluating how boron, carbon and zirconium are distributed at grain boundaries in the as-built and heat-treated microstructures of an alloy containing all these elements. Observations are conducted by scanning and transmission electron microscopy, and atom probe tomography. In the as-built microstructure, boron, carbon and zirconium segregate at high-angle grain boundaries as a result of solute partitioning to the liquid and limited solid-state diffusion during solidification and cooling. After heat-treatment, the amount of boron and carbon segregating at grain boundaries increases significantly. In contrast, zirconium is not found at grain boundaries but it partitions at the γ' precipitates formed during the heat treatment. The presence of zirconium at grain boundaries in the as-built condition is known to be susceptible to enhance hot cracking, while its absence in the heat-treated microstructure strongly suggests that this element has no major effect on the creep resistance. Based on our observations, we propose alloy design guidelines to at the same time avoid hot cracking during fabrication and achieve the required creep performance after heat-treatment.

English

Soybean is a grain legume has the ability to fix atmospheric nitrogen in the soil in association with Brady rhizobium rhizobia. Soybean crop fixes 61-337 Kg Nha-1. Many of scientist reported that as macronutrient needs are met, it becomes possible that micronutrient requirements of the soybean plant could be limiting optimum production and although boron is termed a micronutrient, its role within the plant is widespread. The role of boron within the plant includes cell wall synthesis, sugar transport, cell division, differentiation, membrane functioning, root elongation, and regulation of plant hormone levels. The application of lime and boron were given in the plots as per their treatments prior to sowing. The significant increase in the soybean yield was mainly due to increasing does of lime and boron as well. However, the interaction of lime and boron were not fund significant. The maximum seed yield was increased by the application of lime @ 5 t/ha. However on the other hand, increase in the yield by the application of boron 1 kg/ha. When compared with absolute control. It showed that application of lime and boron separately give the positive effect on soybean grain yield whereas in combination with lime and boron could not play significant increase in crop yield.

Enhanced Photocatalytic Activity of Boron Doped Silicon Carbide Nanofibers and Its Composite with Polyvinyl Borate

ABSTRACT Boron doped silicon carbide (B-SiC) and its composite with polyvinyl borate (PVB) were studied due to the role of boron acting as an electron-acceptor, which can reduce the recombination rate of the photoinduced electron–hole pair on SiC upon UV light irradiation. The structure and morphology of SiC and B-SiC, and their PVB composites were characterized by FTIR, X-ray diffraction spectroscopy and field emission scanning electron microscopy. The optical property and the band gap energy of the as prepared samples were evaluated from UV-Vis absorption spectroscopy. When compared to SiC and PVB/SiC, boron doped SiC and its PVB composite exhibited enhanced photocatalytic activity toward the model dye (methylene blue) degradation owing to the effective separation of the photoinduced electron-hole pair on the photocatalyst nanofibers.