Organic Boron Research Articles

Effect of Animal Organic Fertilizers and Boron spray in Growth of local Mungbean (Vigna radiate L.)

A field experiment was carried out during the autumn season (2020) in one of the agricultural fields of a farmer in the Sufiyah area of Ramadi district in Anbar province using sandy loam textured soil. The aim of this study is to find out the effect of animal manure and boron spraying in the growth of the local mung bean crop (Vigna radiata L.). The experiment was applied to the factorial experiment system according to the design of the Randomized Completely Block Design (R.C.B.D) with three replications, which included four levels of animal manure (0, 6, 12 and 18) tons. ha-1 and three boron concentrations (0, 50 and 100) mg B. L-1. The following results are shown. The levels of animal manure have affected significantly in most of the studied properties, where the level 12 tons. ha-1 gives the highest average for both plant height (78.50 cm). While the level of 18 tons.ha-1 gives the highest average for each of the branches in the plant (6.71) branches. Plant-1 and leaf area (2038.00) cm2.Plant1. As for spraying boron, it was significantly superior in some of the studied traits. The concentration was recorded at 50 mg B. L1- The highest average plant height is (67.80) cm. The effect of the interaction between the levels of compost and boron concentrations is significantly effects on the height of the plant, the number of branches in the plant, the leaf area.

Using liquid organic boron foliar sprays for increasing tomato growth and yield in a hydroponic system

Using liquid organic boron foliar sprays for increasing tomato growth and yield in a hydroponic system

Expanding the boron peroxide chemistry on BODIPY scaffold

Novel stable BODIPY boron mono- and diperoxides were prepared in good yields by TMSOTf activation of mono- and dialkoxy-BODIPY derivatives, followed by ligand exchange with organic hydroperoxides. The reactions of the methoxy derivative of BODIPY with hydroperoxides led to the formation of a novel group of peroxides with the structural element B(F)OOR. The reaction of the dimethoxy derivative of BODIPY with tBuOOH provided the first organic boron diperoxide. Using gem-dihydroperoxide, a cyclic analogue with tetraoxaborinane ring was prepared. Both, mono- and diperoxo boron compounds are stable under ambient conditions, which allowed full characterization of compounds. A mechanistic study provided further insight into their formation and elucidated some of the possible intermediates, namely the borenium cations.

APPRAISAL OF SOIL PROPERTIES OF SOLANUM MELONGENA L. TO DIFFERENT GROWTH CONDITIONS

The response of brinjal plants to organic fertilizers and inorganic fertilizers under pot experiment investigated. This invivo experiment did in the Genetics and Plant Breeding Division of the Department of Botany, University of Calicut. Brinjal plants treated with three sources of organic fertilizers (vermicompost, groundnut cake and bonemeal), three sources of inorganic fertilizers (NPK 16:16:16, NPK 10:5:20 and urea) compared with control. The experimental design followed was a Randomized Complete Block Design (RCBD) with twenty-ve replicates. Soil properties were analyzed by collecting the soil from nine representative samples from each treatment. The soil parameters such as the pH, electrical conductivity (mhos/cm), total organic carbon (%), total organic matter, total nitrogen, phosphorus (kg/ha), potassium (g/ha), manganese, sulphur, iron, zinc, copper and boron were analyzed. The results showed that the macro and micronutrient availability increased in organic fertilizer treatments. Vermicompost increased soil properties signicantly. The percentage of organic carbon increased in organic fertilizer treatments. The same result showed in the case of total organic matter. Groundnut cake treatment gave the highest organic matter (4.75). Total nitrogen was highest in bonemeal (0.95) and potassium was highest in vermicompost (330kg/ha). Phosphorous (48.33kg/ha) and sulphur (43.1mg kg-1) were recorded highest in bonemeal. The highest values of trace elements (25 mg kg-1for Fe in groundnut cake; 0.96mg kg-1Cu, 14mg kg-1 Mn, 5.1mg kg-1 Zn and 0.98 mg kg-1 B in vermicompost observed. Therefore, 38% of the increase in iron, 17.0% off copper,14.75% increase in manganese, 2.82% increase in zinc and 20.99% increase seen in boron.

Synthesis and properties of organoboron functionalized nanocellulose for crosslinking low polymer fracturing fluid system.

The traditional organoboron crosslinker used in the guar gum fracturing fluid has the disadvantages of a larger amount of guar gum and crosslinker and higher susceptibility to pH. Nanoparticles have special properties such as large specific surface area and many active groups, so the organic boron crosslinker and nanoparticles are combined to obtain nano crosslinkers. In this paper, rod-shaped nano-cellulose particles were prepared by acid hydrolysis, and a nanocellulose crosslinker was synthesized by combining with organic boron and KH550. Nanocellulose cross-linker has good temperature and salt resistance. It can meet the requirements of cross-linking guar gum fracturing fluid with a mass fraction of 0.3 wt% under neutral conditions. The residual viscosity is higher than 50 mPa s under shear at 170 s−1 and 110 °C for 60 minutes when the pH increases from 7 to 13, and NBC crosslinking can withstand a temperature of 160 °C under pH = 10. The crosslinking mechanism of the widely accepted nano-crosslinker is that the organoboron on the surface of the nanoparticle combines with the homeopathic ortho hydroxyl of the guar gum molecule to form a hydrogen bond and thereby form a complex network structure. This research shows that the hydrogen bonding between the nano-cellulose crosslinker and HPG molecules, and the resulting gel has a more complex network structure because of the formation of inter-chain cross-links.

Study of Crystallization and Composition on Silicon Oxycarbide (SiOC) and Silicon Boron Oxycarbide (SiBOC) Ceramics Obtained from Alkoxysilanes Precursors

This work deals on the preparation of silicon oxycarbide (SiOC) and silicon boron oxycarbide (SiBOC) ceramics from pyrolysis involving alkoxysilanes with different organic groups. Boron content, organic substituent and annealing time were evaluated on crystallization and composition of resulting ceramics. B-free precursors composed of methyltriethoxysilane (MTES), phenyltriethoxysilane (PTES) and vinyltrimethoxysilane (VTMS) were obtained by the sol-gel method, whilst B-containing precursors were prepared by adding to each alkoxysilane a proper amount of boric acid resulting in B/Si atomic ratios of 0.1 and 0.5. Precursors were pyrolyzed at 1500 °C for 1 and 3 h to produce respective SiOC and SiBOC ceramics. X-ray diffraction (XRD) patterns revealed enhanced SiC phase crystallization for PTES-derived ceramics, followed by those containing vinyl and methyl groups, which was also confirmed by X-ray photoelectron spectroscopy (XPS) from percentages of Si-C and Si-O bonds. Csp2 and Csp3 amounts varied among ceramics, indicating direct influence of organic substituent on conductive carbon phase development. Boron addition induced the growth of SiC crystallites, having more evident effect in matrices with higher proportions of amorphous fraction and lower residual carbon amounts. Organic group nature, boron content and annealing time played an important role for production and evolution of SiC and C phases into ceramics.

(o-Phenylenediamino)borylstannanes: Efficient Reagents for Borylation of Various Alkyl Radical Precursors.

(o-Phenylenediamino)borylstannanes were newly synthesized to achieve radical boryl substitutions of a variety of alkyl radical precursors. Dehalogenative, deaminative, decharcogenative, and decarboxylative borylations proceeded in the presence of a radical initiator to give the corresponding organic boron compounds. Radical clock experiments and computational studies have provided insights into the mechanism of the homolytic substitution (SH 2) of the borylstannanes with alkyl radical intermediates. DFT calculation disclosed that the phenylenediamino structure lowered the LUMO level including the vacant p-orbital on the boron atom to enhance the reactivity to alkyl radicals in SH 2. Moreover, C(sp3 )-H borylation of THF was accomplished using the triplet state of xanthone.

Nanosized ammonia borane for solid-state hydrogen storage: Outcomes, limitations, challenges and opportunities

Ammonia borane NH3BH3 (AB), a material for solid-state hydrogen storage, can be nanosized by confinement into the porosity of a scaffold like mesoporous silica, carbon cryogel, graphene oxide, ZIF-8 as a metal organic framework, poly (methyl acrylate), boron nitride and manganese oxide. In doing so, nanosized AB is destabilized and shows better dehydrogenation properties than bulk AB in terms of temperature, activation energy, enthalpy and kinetics. Such improvements are due to the confinement-driven nanosizing effect, but not only. A catalytic effect may also have a contribution and, in some cases, it even overpasses the nanosizing effect. These effects are explained in detail herein. The present review aims at reporting the outcomes of the AB confinement strategy to help understand the advantages and to identify the limitations which are still not adequately defined. Based on this analysis, the challenges ahead are listed and discussed, and it appears that there are new opportunities to explore. Though nanosized AB is not mature enough for implementation, it has the potential to be developed further. Avenues worth exploring are given.

Effect of combined use of tillage and nutrient management practices on soil quality indicators and indices under maize (Zea mays) based cropping system in rainfed inceptisols

An experiment was conducted in the rainfed Inceptisols of Rakhdhiansar in Kandi areas of Western Himalayas of South Kashmir and Kumaon, India for four years to assess the influence of combined use of tillage and nutrient management treatments on soil quality under maize based cropping system. The experiment was initiated in a split plot design with three main and three sub-treatments using maize (Kanchan-510) as the test crop. The main experimental treatments were: T1: Conventional Tillage (CT) +Two Intercultures (Two IC), T2: Low Tillage (LT) +Two Intercultures (Two IC) and T3: Low Tillage (LT) + Weedicide + One Interculture (One IC). The three sub treatments were, T1: 100% N through organic sources (compost), T2: 50% N through organic sources + 50% N through inorganic sources and T3: 100% N through inorganic sources. The results of the present study clearly revealed that the tillage treatments did not significantly influence most of the soil quality parameters except available S, microbial biomass carbon (MBC) and Mean weight Diameter of Soil Aggregates (MWD). When averaged over nutrient levels, among the tillage practices, conventional tillage + Two IC recorded the highest available S of 20.87 kg ha-1. However, sub-sub treatments viz nutrient management significantly influenced the organic carbon (OC), available N, P S and boron, dehyrogenase assay (DHA), labile carbon (LC), bulk density (BD) and MWD. When averaged over tillage levels, the application of nutrients through inorganic sources recorded significantly highest available N (160.50 kg ha-1), P (30.67 kg ha-1) and K (207.87 kg ha-1 in soil. Finally, in terms of Relative Soil Quality Indices (RSQI), Low tillage + Two IC (0.87) and Low tillage + Weedicide + One IC (0.89) proved superior compared to Conventional Tillage + 2 IC (0.82). Similarly, when averaged over tillage levels, the order of performance of nutrient management treatments was:100% N through organic sources (0.93) > 50% N through organic sources + 50 % N through inorganic sources (0.84) > 100% N through inorganic sources (0.82). Though the interactions between tillage levels and nutrient management were not significant, but the combination of Low tillage practices with 100 % organic Source of nutrients was quite superior in maintaining relatively higher RSQI. Thus, the results of the present study and methodology used will be highly useful to different stake holders associated withland and soil quality management

Study of the preparation and extinguishment characteristic of the novel high-water-retaining foam for controlling spontaneous combustion of coal

For enhancing the wetting effect of foam on residual coal in goaf to control spontaneous combustion of coal efficiently, this study proposed the novel high-water-retaining foam with excellent water retention and extinguishment performance. Polymer composite (PC) as thickening agent and organic boron complex (OBC) as crosslinking agent were introduced into foam system to form gel structure by borate/cis-hydroxy bonds in foam film to hold water. Preparation experiments indicated that high-water-retaining foam with the component range of 3.4 ~ 4.8 g/L PC and 2.0 ~ 3.4 g/L OBC showed the crosslinking time more than 30 min, which was conducive for foam to spread fully to cover and wet the residual coal in goaf. Considering the foam foamability and stability, this study revealed that the optimal component proportion of high-water-retaining foam was 4.0 g/L PC and 3.0 g/L OBC, exhibiting the largest foam comprehensive value of 529.82 and best foam performance. Water retention capacity of foam tests indicated that high-water-retaining foam could hold the water in foam system above 60% after placing 120 h, while traditional aqueous foam had lost 98% water. And coal-fire extinguishing tests indicated better extinguishment characteristic of high-water-retaining foam than that of traditional aqueous foam as evidenced by faster cooling and extinguishment rate to burning coal for the novel foam. Moreover, high-water-retaining foam would cover the coal fully for a long term to prevent oxygen from feeding the fire, finally controlling spontaneous combustion of coal efficiently.

Cyclic oxonium derivatives of cobalt and iron bis(dicarbollides) and their use in organic synthesis

The rapid progress in the chemistry of carboranes and other polyhedral boron compounds makes the development of methods for the synthesis of their various functional derivatives a high priority. The formation of cyclic oxonium derivatives followed by the ring opening is one of the most efficient methods for the preparation of these compounds. This review addresses the data on the use of the nucleophilic ring opening of cyclic oxonium derivatives based on cobalt and iron bis(dicarbollides), which have been extensively studied in recent years. Reactions involving O-, N-, S-, P- and C-nucleophiles are considered as a route to the targeted synthesis of a wide range of organic boron derivatives, in particular various boron-containing biologically active compounds. Possible applications of the reaction products are discussed.The bibliography includes 197 references.

Importance of trimethyl borate temperature used during gas boriding for microstructure, nanomechanical properties and residual stresses distribution on the cross-section of the produced layer

The aim of this work was to indicate the possibility of applying organic compounds as a boron source for gas boriding. In the present work the trimethyl borate was used as an organic boron source for gas boriding process. The process was carried out at 950 °C for 2 h in gaseous atmosphere composed of N2–H2–B(CH3O)3. The temperature of trimethyl borate influenced on its concentration in gas atmosphere. As a result, depending on B(CH3O)3 temperature of 20 °C or 50 °C, it was possible to arranging the two types of process: boriding and borocarburizing, respectively. In the case of gas boriding the single-phase Fe2B layer was produced. The high temperature of B(CH3O)3 caused release of free atoms of carbon, therefore there existed favorable conditions for carburizing. The produced borocarburized layer consisted of two zones: an outer Fe2B borided layer and an inner carburized zone. The thickness of boride layer was higher after boriding process than simultaneous borocarburizing process, 10.8 μm and 7.8 μm, respectively. Whereas, the depth of zone of carbon diffusion was equal ca. 400 μm. For nanomechanical properties, as well as, the residual stress distribution the nanoindentation tester Anton Paar NHT3 equipped with the Berkovich diamond tip under a maximum load of 10 mN was used. In both layers, the highest hardness HIT (7.8–17.9 GPa) and highest Young's modulus (222–368 GPa) were measured in Fe2B layer. However, the presence of thick zone of carbon diffusion was the reason for gradually decrease in hardness in the cross section of borocarburized layer. Moreover, the presence of carburized zone advantageous influenced on residual stresses distribution across the layer. The gradually changes of residual stresses from compressive to tensile were observed in the case of simultaneous gas borocarburized layer. Such a situation was more advantage than those obtained for gas borided layer.

Приоритетные факторы риска питьевой воды систем централизованного питьевого водоснабжения, формирующие негативные тенденции в состоянии здоровья населения

Our research object was long-term dynamics of parameters describing drinking water from centralized water supply systems and additional cases of health disorders among population in Russia directly caused by low-quality drinking water. Our research goal was to perform hygienic assessment of priority risk factors related to drinking water and potential health disorders that could be caused by them. Our research technique was hygienic analysis of drinking water parameters as per data taken from the federal statistical form No. 18 entitled «Data on sanitary situation in a RF region» over 2000–2019, the federal information fund of social and hygienic monitoring over 2012–2019, and calculation of associated health disorders as per MG 5.1.0095–14. Specific weight of centralized water supply sources that didn’t conform to sanitary-epidemiologic requirements decreased by 4.7 % over 2000–2019 and amounted to 14.9 %. Over the last 20 years there has been a descending trend in specific weight of water samples taken from centralized water supply sources that don’t conform to sanitary requirements as per sanitary-chemical parameters (by 2.7 %) and microbiological parameters (by 4.8%). Over 2000–2019, specific weight of water distribution networks not conforming to sanitary-epidemiologic requirements decreased by 10.7 % and amounted to 15.9 % in 2019. Over the last 20 years there has been an increase in quality of drinking water taken from centralized distribution networks. Specific weight of water samples from centralized distribution networks not conforming to sanitary requirements as per microbiological and sanitary-chemical parameters fell by 6.7 % and 7.9 % respectively. In 2012–2019 in the RF hygienic parameters of drinking water quality were the most violated as per contents of bromine, silicon, chlorine, iron, sodium, lithium, magnesium, manganese, chloroform, boron, strontium, sulfides, and hydrogen sulphide. Overall, in the RF in 2019 more than 1.66 million cases of digestive diseases, cardiovascular diseases, diseases of skin and subcutaneous tissue, and other health disorders were directly related to drinking water being contaminated with chemicals and microbiological agents; it was by 13.3 % lower than in 2012 regarding morbidity associated with drinking water quality. Priority risk factors were chlorine, chlorine organic compounds (COC), ammonia, iron, manganese, arsenic, nickel, copper, boron, magnesium, and other compounds.

Priority risk factors related to drinking water from centralized water supply system that create negative trends in population health

Our research object was long-term dynamics of parameters describing drinking water from centralized water supply systems and additional cases of health disorders among population in Russia directly caused by low-quality drinking water. Our research goal was to perform hygienic assessment of priority risk factors related to drinking water and potential health disorders that could be caused by them. Our research technique was hygienic analysis of drinking water parameters as per data taken from the federal statistical form No. 18 entitled «Data on sanitary situation in a RF region» over 2000–2019, the federal information fund of social and hygienic monitoring over 2012–2019, and calculation of associated health disorders as per MG 5.1.0095–14. Specific weight of centralized water supply sources that didn’t conform to sanitary-epidemiologic requirements decreased by 4.7 % over 2000–2019 and amounted to 14.9 %. Over the last 20 years there has been a descending trend in specific weight of water samples taken from centralized water supply sources that don’t conform to sanitary requirements as per sanitary-chemical parameters (by 2.7 %) and microbiological parameters (by 4.8%). Over 2000–2019, specific weight of water distribution networks not conforming to sanitary-epidemiologic requirements decreased by 10.7 % and amounted to 15.9 % in 2019. Over the last 20 years there has been an increase in quality of drinking water taken from centralized distribution networks. Specific weight of water samples from centralized distribution networks not conforming to sanitary requirements as per microbiological and sanitary-chemical parameters fell by 6.7 % and 7.9 % respectively. In 2012–2019 in the RF hygienic parameters of drinking water quality were the most violated as per contents of bromine, silicon, chlorine, iron, sodium, lithium, magnesium, manganese, chloroform, boron, strontium, sulfides, and hydrogen sulphide. Overall, in the RF in 2019 more than 1.66 million cases of digestive diseases, cardiovascular diseases, diseases of skin and subcutaneous tissue, and other health disorders were directly related to drinking water being contaminated with chemicals and microbiological agents; it was by 13.3 % lower than in 2012 regarding morbidity associated with drinking water quality. Priority risk factors were chlorine, chlorine organic compounds (COC), ammonia, iron, manganese, arsenic, nickel, copper, boron, magnesium, and other compounds.

Tuning the structure of borane-nitrogen derivatives towards high-performance carbon nanotubes-based n-type thermoelectric materials

Recently, single-walled carbon nanotubes (SWCNTs)-based thermoelectric (TE) materials have received much interest owing to their advantages, such as high electrical conductivity and flexibility, as well as their ability to be easily tuned to exhibit p-type or n-type characteristics by the addition of redox reagents. Compared with the numerous p-type composites, less n-type agents have been reported. Borane-nitrogen derivatives (BNs) have been widely used as reducing agents; however, little attention has been paid on their TE performance. As the reducing ability of BNs can be tuned by the basicity and steric hindrance of the nitrogen containing derivatives, herein, pyridineborane (PYB), morpholineborane (MPB) and N,N-diethylanilineborane (DEANB) were investigated as n-type dopants of SWCNTs by simply dispersing each of them with SWCNTs in various solvents. The results suggested the structures of the borane complexes and their reducing ability affect the TE properties greatly. Among them, SWCNT/PYB displayed the best performance at all the investigated temperatures, with power factors ranging from 193.6 μW m−1 K−2 to 223.8 μW m−1 K−2, which are the highest PF values reported to date based on boron containing SWCNT composites. In addition, the TE devices containing five p-n junctions were also combined. SWCNT/PYB exhibited a higher open-circuit voltage (28.8 mV) and output power (1.15 μW) than SWCNT/NaBH4 (23.7 mV, 0.79 μW) at the same conditions. Our results suggest that organic boron compounds can be developed as good agents for boosting the performance of n-type TE materials.

Comparative Assessment of Changes in the Blood Coagulation System in Rats When Exposed to Organic Boron Compounds of Various Chemical Structures

Background. Despite the available information on the clinical manifestations of acute and chronic intoxication with boron compounds, no clear evidence was found among studies to research the effect of boron compounds with different chemical structures on key factors of the blood coagulation system. The data are presented in full for the first time. Aim of the study. Identification of possible signs of the effect of boron compounds on selected indicators of hemostasis in laboratory animals and their characteristics depending on the chemical structure of the compounds. Methods. Modern methods of studying hemostasis are used. Nonlinear rats were chosen as the experimental biological model. Once through the mouth, in the maximum tolerated dose, the following drugs were administered: isopropylmethacarborane, 1,2-di(oxymethyl)orthocarborane, 1,7-di(oxymethyl)methacarborane, polyethylammonium triethylammonium salt, boric acid. Research conducted against a background of dynamic control. Results. Materials were obtained that testify to the effect of boron compounds under the conditions of this experiment on factors of the blood coagulation system. The differences in this effect are established in connection with the chemical structure of the compounds, which are especially pronounced after the introduction of methacarboranes. The effect of orthocarborane and the polyethylammonium triethylammonium salt on factors was less significant. An important fact is that boric acid per se, by its effect on the blood coagulation system, turned out to be less effective than other compared compounds. Conclusion. The polytropy of the toxic effect of boron compounds of different chemical structures was confirmed, including with the involvement of the blood coagulation system, but with the essential features of each of them under conditions of a single exposure to laboratory animals in the maximum tolerated dose.

Hyperspectral Spectroscopic Study of Soil Properties- A Review

Soil analysis is required for efficient use of inputs viz. seeds, fertilizers, irrigation water and other agricultural planning. However, there are several disadvantages of soil analysis such as they are time consuming, expensive and labour intensive. Many approaches are developed to overcome these difficulties. Hyperspectral spectroscopy is emerging as a promising tool for studying soil, water and vegetation. Therefore, an attempt has been made to review the scope of using hyperspectral reflectance spectroscopy for estimation of soil properties as an alternative to traditional laboratory soil analysis methods.
 Spectral signature of soil can be used for fast and non destructive estimation of soil properties. Diffuse reflectance in 350-2500 nm range of electromagnetic spectra forms the basis of hyperspectral spectroscopy. An object is characterized by the characteristic absorptions and peaks in the electromagnetic spectra. A number of calibration techniques are applied for establishing relationship between reflectance spectra and soil properties. Multiple Linear Regression (MLR), Principal Component Regression (PCR) and Partial Least Square Regression (PLSR) are most commonly used techniques.
 MLR, PCR and PLSR are also used for prediction of several soil properties such as pH, soil organic carbon content, nitrogen, phosphorus, potassium, calcium, magnesium, sodium, iron, manganese, zinc, copper, boron, molybdenum, sand silt, clay and soil moisture. Some commonly used spectral indices are also applied for prediction of soil properties. Some of the soil physical properties viz. sand, silt and clay as well as chemical properties viz. pH and organic carbon could be estimated with good to very good prediction using pure spectra of soil. However, contrasting results of prediction of soil properties using multivariate analysis techniques have also been reported. The content of this review article will be helpful for researchers who are working on alternate methods of estimation of soil properties.

Gas Technique of Simultaneous Borocarburizing of Armco Iron Using Trimethyl Borate

The gas boriding process is an appropriate technique used for increasing the hardness and wear resistance of iron and steels. However, the boron halides (e.g., BCl3, BF3) are rarely used as a boron source during gas boriding in industry due to the toxic character of these reagents. The possibility of the use of organic compounds as a boron source in plasma assisted processes was the instigation to determine the possibility of applying these agents for gas boriding. In the present work trimethyl borate was used as an organic boron source. The use of a N2–H2–B(CH3O)3 atmosphere ensured the appropriate conditions for the simultaneous gas borocarburizing of Armco iron. The process was carried out at 1223 K (950 °C) for 2 h. The produced layer consisted of two zones: an outer zone containing a diffusion of boron atoms and an inner zone containing a diffusion of carbon atoms, under the outer zone. Due to the reduction of trimethyl borate with hydrogen, free atoms of carbon were released for the gas atmosphere. Therefore, there existed favorable conditions for carburizing. Unfortunately, the formation of a carburized layer was the reason for the difficult diffusion of boron atoms. As a consequence, the boron diffusion front was hindered, and the outer boride layer was relatively thin (ca. 7.8 µm). The boride layer contained only Fe2B phase, which was characterized by high hardness in the range from 1103 HV0.01 to 1546 HV0.01. The presence of iron borides in the outer layer was also the reason for increased wear resistance in comparison with untreated Armco iron.

Impact of bonfires on soil properties in an urban park in Vilnius (Lithuania)

Lighting bonfires in urban parks is a widespread practice. However, few studies have examined their impact on soil properties. The aim of this study was to analyze the impact of bonfires on the soil properties of an urban park in Vilnius, Lithuania. The properties studied were soil water repellency (SWR), aggregate stability (AS), soil organic matter (SOM) content, total nitrogen (TN), inorganic carbon (IC), pH, electrical conductivity (EC), extractable calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), aluminum (Al), manganese (Mn), iron (Fe), zinc (Zn), copper (Cu), boron (B), chromium (Cr), available phosphorus (P), silicon (Si) and sulfur (S). Soil ratios calculated were carbon/nitrogen ratio (C/N), Ca + Mg/(Na + K)1/2 (SPAR), Ca:Al and Ca:Mg. Three areas were studied: Site 1) Pinus sylvestris L. and Quercus robur L.; Site 2) Aesculus glabra Wild.; and Site 3) Pinus sylvestris L. and Acer plantanoides L. At each site, 20 samples were collected (10 within the bonfire area, 10 from a control area). The results showed significantly higher values of SOM, IC, pH, EC, Ca, Mg, Na, K, P, Al, Zn, Cu, Cr, S, C/N ratio, Ca:Al ratio and Ca:Mg ratio in bonfire soils than in control unburned soils. In bonfire soils, significantly lower values were recorded of SWR, AS, TN, SOM, Al, Mn, Fe, Cr, S and SPAR comparing to control soils. Most affected area by the bonfire was Site 1, which presented a marked increase in heavy metal content comparing to the control. The impact of soil heating was evident in AS, IC, pH, extractable Ca, Mg, Na, K, P, Al, Zn, Cu, Cr, S, and in its ratios. Protective measures are needed to limit bonfires and prohibit the burning of hazardous materials.

Boron content of large soil groups of Siverek (Şanlıurfa) region

In the study, it was aimed to determine the boron content of the large soil groups in Siverek county of Şanlıurfa province and to determine relations with some properties of the soil. For this purpose, a total of 76 soil samples were taken from two different depths (0-20 and 20-40 cm) and 38 points, representing the large soil groups of Siverek county of Şanlıurfa. Texture, pH, salt, lime, organic matter and available boron contents of the soils were determined in the samples. The results of the research show that the pH contents of soils is between 6.91-7.98; salt content is between 0.02-0.13%; clay content is between 24.32-67.76%; sand content is between 2.40-62.96%; silt content is between 6.00-68.72%; lime content is between 0.38-14.55%; organic matter content is between 1.11-3.35% and boron content of them is between 0.01-1.99 ppm. The obtainable boron content of the large soil groups of Siverek county of Şanlıurfa province was found to be 65.38% too little , 26.32% little, 7.90% adequate at the depth of 0-20 cm, whereas it was found to be 81.58% too little, 15.79% little and 2.63% sufficient at 20-40 cm depth. It was determined that there is a positive significant relationship between the obtainable boron content of soil and pH and lime contents. In addition, significant positive relationships between pH content and silt and lime were determined. Not only a negative significant relation between clay content and silt content of soils was determined, but negatively significant relations between sand content and silt and organic matter were determined, as well. At the same time, positive correlations were determined between the lime content of the soils and the organic matter.00