Boric Research Articles

Where do the Fluorine Atoms Go in Inorganic-Oxide Fluorinations? A Fluorooxoborate Illustration under Terahertz Light.

The substitution of fluorine atoms for oxygen atoms/hydroxyl groups has emerged as a promising strategy to enhance the physical and chemical properties of oxides/hydroxides in fluorine chemistry. However, distinguishing fluorine from oxygen/hydroxyl in the reaction products poses a significant challenge in existing characterization methods. In this study, we illustrate that terahertz (THz) spectroscopy provides a powerful tool for addressing this challenge. To this end, we investigated two fluorination reactions of boric acid, utilizing MHF2 (M=Na, C(NH2)3) as fluorine reagents. Through an interplay between THz spectroscopy and solid-state density functional theory, we have conclusively demonstrated that fluorine atoms exclusively bind with the sp3-boron but not with the sp2-boron in the reaction products of Na[B(OH)3][B3O3F2(OH)2] (NaBOFH) and [C(NH2)3]2B3O3F4OH (GBF2). Based on this evidence, we have proposed a reaction pathway for the fluorinations under investigation, a process previously hindered due to structural ambiguity. This work represents a step forward in gaining a deeper understanding of the precise structures and reaction mechanisms involved in the fluorination of oxides/hydroxides, illuminated by the insights provided by THz spectroscopy.

High temperature synthesis, surface characterization, and photoluminescence property of boron carbon nitride

The present study demonstrates the synthesis of boron carbon nitride (BCN) by molten salt method which utilizes melamine (source of carbon and nitrogen), boric acid (source of boron) and potassium chloride as the salt. The synthesis is performed at 915 °C for 4 h under N2-atmosphere. The synthesized material is further acid-treated. The physicochemical characterization data for as-synthesized and acid-treated materials confirm successful synthesis of BCN. SEM and AFM data display that synthesized BCN pre and post acid-treatment exhibit sheet-type morphology. Thermogravimetric analysis data confirm that the acid-treated material is thermally stable up to 800 °C, with only 2 % mass-loss is observed till 800 °C. Water contact angle measurement study demonstrates that acid-treatment significantly improves the surface hydrophilicity. Additionally, the low photoluminescence peak intensity of the acid-treated material indicates low electron-hole pair recombination rate. The synthesized material may be useful for the photocatalytic degradation of potentially toxic chemicals from water.

High-pressure batch reverse osmosis (RO) for zero liquid discharge (ZLD) in a Cr(III) electroplating process

A batch RO system was designed and built for high-pressure (120 bar) operation. The system was developed for a ZLD application involving treatment of metal plating wastewater from a Cr(III) electroplating process at a major industrial plant. Hybrid semi-batch/batch operation enabled a compact design to be achieved. To maximize water recovery without exceeding a set peak pressure, a method for controlling the switch point between semi-batch and batch phases was developed. The system was tested with feed representative of rinse water from the electroplating process. A range of feed concentrations (at 10–20× dilution of the plating bath), feed flows (0.21–0.46 m3/h), water fluxes (6–14 LMH) and water recoveries (87–95.7 %) were investigated. The system successfully recovered Cr(III) and restored its concentration to that of the electrolyte bath, thus meeting the requirements for reuse in the electroplating process. Rejection of most species was >99.8 %, sufficient for reuse of the permeate as rinse. However, rejection of boric acid was only 69–80 % such that a second RO pass may be needed to remove boric acid. Specific Energy Consumption was <2.25 kWh per m3 of treated rinse water, representing a 50-fold saving compared to the current method of treatment and disposal at the industrial plant.

Minute-level synthesis of tunable carbon dots-based phosphorescence materials for information encryption and light-emitting diodes

The emergence of carbon dots has broadened the design and application of new room-temperature phosphorescence materials, but the mass production of long-lived color-tunable carbon dots-based phosphorescence materials (CDPMs) is still hindered by solvent dependence and time-consuming. In this work, a minute-level solid-phase synthesis strategy was proposed for the preparation of a series of CDPMs through pyrolyzing the mixture of boric acid and pimelic acid. By tuning the mass ratio of boric acid and pimelic acid, CDPMs with different room-temperature phosphorescence characterises can be obtained within 7 min. Preferably, the CDPMs-60 synthesized from the mass ratio of boric acid and pimelic acid of 60:1 exhibits a long afterglow length up to 10 s and has obvious phosphorescence chromatic aberrations following excitation at 254 and 365 nm, and phosphorescence lifetimes of CDPMs-60 in the blue and green band can reach 1030 ms and 555 ms, respectively. The CDPMs were further successfully applied for the information encryption and fabricating light emitting diodes based on their simple synthesis process, exceptional optical properties and low-toxicity. This study may provide a valuable reference for the facile synthesis and suitable commercial application of room temperature phosphorescence materials.

Calcium silicate solid-state matrices from boric acid production waste for 60Co removal and immobilization by spark plasma sintering

A mesoporous adsorbent based on calcium silicate CaSiO3 for the removal and immobilization of cobalt 60Co radionuclides in durable ceramic CaCoSi2O6 matrices was synthesized by hydrothermal conversion of boric acid production waste. The obtained material had a high Co2+ ions adsorption capacity of 220.8 mg/g. Cobalt adsorption was carried out mainly by ion exchange, which led to the formation of CaCoSi2O6 precursor ceramic matrices. The use of spark plasma sintering (SPS) technology at an optimal temperature of 1000 °C allowed the safe immobilization of Co2+ ions in CaCoSi2O6 ceramic matrices characterized by density (3.33 g/cm3), compressive strength (481 MPa) and microhardness (∼9.81 GPa). Sintered CaCoSi2O6 ceramic samples were characterized by high hydrolytic stability (cobalt leaching rate RCo ∼10−7 g/(cm2 × day)) and complied with the requirements for cured highly active waste GOST R 50926 96/ANSI/ANS 16.1.

Heat-induced morphology-dependent corrosion of solid boric acid on carbon steel

The corrosion of solid boric acid (s-BA) has so far remained unnoticed, which could pose a potential hazard to the safety of boron-containing equipment. In this work, a morphology-dependent corrosion behavior of s-BA was found on Q235 carbon steel encompassing temperatures from 160 °C to 240 °C. Concurrent with the corrosion process, s-BA underwent a heat-induced morphology-transition from block-like into sheet-like/flake-like under the delayed decomposition condition, which emerged as a key contributor to the heightened corrosion rates after reducing the volume of the corrosion system. Through integration with the ex-situ pretreatment experiment, our analysis concludes that this morphology-transition accelerated corrosion by facilitating the generation of more Fe5O5[B6O10(OH)3] ·nH2O and filamentous amorphous corrosion products than FeB12O19·5H2O. The crucial relationship between s-BA with distinct morphologies and different types of borate products was also further expounded.

Properties of laminated board from Belangke bamboo (Gigantochloa pruriens) modified with citric acid, boric acid, and polystyrene

ABSTRACT The development of bamboo as a raw material for construction materials has drawbacks, including low physical properties. Therefore, this work aimed to determine the physical and mechanical properties of laminated boards modified with citric acid, boric acid, and polystyrene. In addition, the study analysed the optimum immersion time and the phenomenon of the modifications provided. Two-step conditions were designed for the immersion of bamboo lamina. The first steps were prepared at different variation times (6, 12, and 24 h). The effect of variation time was evaluated to obtain the optimum duration treatment of bamboo lamina. Then, another step of bamboo lamina was immersion for different solutions (citric acid, boric acid, and polystyrene) at an immersion time of 6 h. The bamboo lamina was assembled into laminated boards (3 layers) measuring 30 cm × 15 cm × 1.5 cm (length × width × thickness) using isocyanate adhesive with adhesive spread level of 280 g/m2 using the double adhesive spread technique. The physical and mechanical properties of the laminated board were tested according to the JAS 234:2003 standard. The laminated board modified with polystyrene has higher density, lower delamination, higher shear strength, and higher modulus of elasticity (MOE) and modulus of rupture (MOR) than that modified with citric acid and boric acid. In addition, the bamboo laminated with 6 h and polystyrene immersion has density, moisture content, delamination, MOE, and MOR that meet the JAS 234:2003 standard. These phenomena are due to changes in the functional group and crystallinity of bamboo laminated after immersion.

Double cross-linked graphene oxide hydrogel for promoting healing of diabetic ulcers.

This study explores the synthesis and characterization of a novel double cross-linked hydrogel composed of polyvinyl alcohol (PVA), sodium alginate (SA), graphene oxide (GO), and glutathione (GSH), henceforth referred to as PVA/SA/GO/GSH. This innovative hydrogel system incorporates two distinct types of cross-linking networks and is meticulously engineered to exhibit sensitivity to high glucose and/or reactive oxygen species (ROS) environments. A sequential approach was adopted in the hydrogel formation. The initial phase involved the absorption of GSH onto GO, which was subsequently functionalized with boric acid and polyethylene glycol derivatives via a bio-orthogonal click reaction. This stage constituted the formation of the first chemically cross-linked network. Subsequently, freeze-thaw cycles were utilized to induce a secondary cross-linking process involving PVA and SA, thereby forming the second physically cross-linked network. The resultant PVA/SA/GO/GSH hydrogel retained the advantageous hydrogel properties such as superior water retention capacity and elasticity, and additionally exhibited the ability to responsively release GSH under changes in glucose concentration and/or ROS levels. This feature finds particular relevance in the therapeutic management of diabetic ulcers. Preliminary in vitro evaluation affirmed the hydrogel's biocompatibility and its potential to promote cell migration, inhibit apoptosis, and exhibit antibacterial properties. Further in vivo studies demonstrated that the PVA/SA/GO/GSH hydrogel could facilitate the healing of diabetic ulcer sites by mitigating oxidative stress and regulating glucose levels. Thus, the developed PVA/SA/GO/GSH hydrogel emerges as a promising candidate for diabetic ulcer treatment, owing to its specific bio-responsive traits and therapeutic efficacy.

Cooperative Photoredox and N-Heterocyclic Carbene Catalysis Suzuki-Miyaura-Type Reaction: Radical Coupling of Aroyl Fluorides and Alkyl Boronic Acids.

An intermolecular Suzuki-Miyaura-type reaction of benzoyl fluorides with alkyl boronic acids to synthetic ketone was revealed by cooperative N-heterocyclic carbene (NHC) and photoredox catalysis. Various alkyl boric acids can be converted into alkyl radicals without external oxidants or activators. Moreover, the catalytic system was feasible for the difunctionalization of styrenes via a radical relay process. Mechanistic experiments suggested that the benzoate anion intermediate might play a unique role in this reaction system.

Studies on pollen micro-morphology, pollen storage methods, and cross-compatibility among grape (Vitis spp.) genotypes.

The knowledge of pollen morphology, suitable storage condition, and species compatibility is vital for a successful grapevine improvement programme. Ten grape genotypes from three different species, viz., Vitis vinifera L., Vitis parviflora Roxb., and Vitis champini Planc., were studied for their pollen structure and pollen storage with the objective of determining their utilization in grape rootstock improvement programs. Pollen morphology was examined through the use of a scanning electron microscope (SEM). The viability of the pollen was assessed using 2,3,5-triphenyltetrazolium chloride (TTC). In vitro pollen germination was investigated using the semi-solid medium with 10 % sucrose, 100 mg/L boric acid, and 300 mg/L calcium nitrate. The results revealed variations in pollen micro-morphology in 10 genotypes, with distinct pollen dimensions, shapes, and exine ornamentation. However, species-wise, no clear difference was found for these parameters. Pollen of V. parviflora Roxb. and Dogridge was acolporated and did not germinate. The remaining eight genotypes exhibited tricolporated pollen and showed satisfactory in vitro pollen germination. Storage temperature and duration interactions showed that, at room temperature, pollen of most of the grape genotypes can be stored for up to 1 day only with an acceptable pollen germination rate (>30 %). However, storage for up to 7 days was successfully achieved at 4 °C, except for 'Pearl of Csaba'. The most effective storage conditions were found to be at -20 °C and -196 °C (in liquid N2), enabling pollen storage for a period of up to 30 days, and can be used for pollination to overcome the challenge of asynchronous flowering. Four interspecific combinations were studied for their compatibility, among which V. parviflora Roxb. × V. vinifera L. (Pusa Navrang) and V. parviflora Roxb. × V. champini Planc. (Salt Creek) showed high cross-compatibility, offering their potential use for grape rootstock breeding. However, V. parviflora Roxb. × V. vinifera L. (Male Hybrid) recorded the lowest compatibility index among studied crosses. In the case of self-pollinated flowers from V. parviflora Roxb. and V. parviflora Roxb. × V. champini Planc. (Dogridge), pollen failed to germinate on the stigma due to male sterility caused by acolporated pollen. As a result, the flowers of these genotypes functioned as females, which means they are ideal female parents for grape breeding without the need for the tedious process of emasculation.

The investigation of synthesis and textured properties of in situ formed hBN with spark plasma sintering

Hexagonal boron nitride (hBN) exhibits high thermal conductivity within the in-plane direction and significantly lower thermal conductivity in the cross-plane direction because of its anisotropic nature. When the texture properties of bulk hBN are strong, it is a potentially promising application area for the insulating heat spreaders and heat sinks. In this study, hBN was synthesized in situ with the spark plasma sintering (SPS) technique and the effects of sintering temperature on the orientation of hBN grains were investigated. The precursor was prepared by chemically reacting urea and boric acid in heat treatment at 850 °C. The hBN was produced using the previous precursor in a SPS at 1500, 1700, and 1900 °C. The samples were characterized using XRD, FTIR, SEM and Raman spectroscopy. The properties of the samples were further determined through measurements of density, DSC and thermal diffusivity. The hBN samples obtained through the SPS process have nano and micron-size grains. The hBN was highly crystalline and homogeneous, as determined by the XRD pattern, Raman spectra and Raman maps. The orientation of hBN grains has been revealed in the c-axis of hBN crystallites and was preferably arranged within a plane parallel to the SPS pressing direction. The hBN orientation preference index (IOP) value of −19925.5 at 1700 °C indicates the highest quality texture orientation. Increasing the temperature to 1900 °C decreased the orientation in the direction parallel to the pressing direction. The highest thermal conductivity calculated according to the thermal diffusivity perpendicular to the sintering pressure direction was 8.86 W m−1K−1 at 1900 °C.

Evaluation of effect of boric acid on thermoplastic starch: Morphological, mechanical, barrier, and optical properties

AbstractIn this study, starch was modified with different amounts of boric acid, and the degree of substitution of the synthesized compounds at different temperatures and times was determined by Fourier transform infrared (FTIR) and titration methods. The degrees of substitution in both methods showed similar tendency. Optimum conditions were determined, and thermoplastic starch (TPS) and boric acid (B) films were prepared by casting method using glycerol as plasticizer. The morphological properties of the films were studied by scanning electron microscope‐energy dispersive spectrometry (SEM‐EDS). According to the FTIR results, it was observed that the BO and BOC stretching vibrations increased when the amount of boric acid increased. The tensile strength, water barrier (swelling capacity, solubility, and water vapor permeability), and optical properties of samples were investigated. The swelling capacity, solubility, and water vapor permeability of the films decreased with the addition of 0.5% boric acid to the starch, but the highest tensile strength was achieved. The tensile strength for TPSB0.5% increased compared to control group TPS. In addition, the film showed the highest transparency. Thermoplastic film containing 0.5% boric acid can be used as a packaging material due to its improved mechanical and water barrier.Highlights The thermoplastic starch and boric acid composite were successfully produced. The presence of boric acid was confirmed by energy dispersive spectrometry (EDS). The degree of substitution was determined by two different methods. Transparency increased with the addition of boric acid. Tensile strength improved with boric acid content.

Systematic development of immunohistochemistry protocol for large cryosections-specific to non-perfused fetal brain

BackgroundImmunohistochemistry (IHC) is an important technique in understanding the expression of neurochemical molecules in the developing human brain. Despite its routine application in the research and clinical setup, the IHC protocol specific for soft fragile fetal brains that are fixed using the non-perfusion method is still limited in studying the whole brain. New methodThis study shows that the IHC protocols, using a chromogenic detection system, used in animals and adult humans are not optimal in the fetal brains. We have optimized key steps from Antigen retrieval (AR) to chromogen visualization for formalin-fixed whole-brain cryosections (20 µm) mounted on glass slides. ResultsWe show the results from six validated, commonly used antibodies to study the fetal brain. We achieved optimal antigen retrieval with 0.1 M Boric Acid, pH 9.0 at 70°C for 20 minutes. We also present the optimal incubation duration and temperature for protein blocking and the primary antibody that results in specific antigen labeling with minimal tissue damage. Comparison with existing methodsThe IHC protocol commonly used for adult human and animal brains results in significant tissue damage in the fetal brains with little or suboptimal antigen expression. Our new method with important modifications including the temperature, duration, and choice of the alkaline buffer for AR addresses these pitfalls and provides high-quality results. ConclusionThe optimized IHC protocol for the developing human brain (13–22 GW) provides a high-quality, repeatable, and reliable method for studying chemoarchitecture in neurotypical and pathological conditions across different gestational ages.

The Synthesis of Three-Dimensional Hexagonal Boron Nitride as the Reinforcing Phase of Polymer-Based Electrolyte for All-Solid-State Li Metal Batteries.

Powdery hexagonal boron nitride (h-BN), as an important material for electrochemical energy storage, has been typically synthesized in bulk and one/two-dimensional (1/2D) nanostructured morphologies. However, until now, no method has been developed to synthesize powdery three-dimensional (3D) h-BN. This work introduces a novel NaCl-glucose-assisted strategy to synthesize micron-sized 3D h-BN with a honeycomb-like structure and its proposed formation mechanism. We propose that NaCl acts as the template of 3D structure and promotes the nitridation reaction by adsorbing NH3 . Glucose facilitates the homogeneous coating of boric acid onto the NaCl surface via functionalizing the NaCl surface. During the nitridation reaction, boron oxides (BO4 and BO3 ) form from a dehydration reaction of boric acid, which is then reduced to O2 -B-N and O-B-N2 intermediates before finally being reduced to BN3 by NH3 . When incorporated into polyethylene oxide-based electrolytes for Li metal batteries, 5 wt % of 3D h-BN significantly enhances ionic conductivity and mechanical strength. Consequently, this composite electrolyte demonstrates superior electrochemical stability. It delivers 300 h of stable cycles in the Li//Li cell at 0.1 mA cm-2 and retains 89 % of discharge capacity (138.9 mAh g-1 ) after 100 cycles at 1 C in the LFP//Li full cell.

Synthesis of the magnetic composite of Ni-MOF-I in aqueous medium and its application in magnetic dispersive micro solid phase extraction of plasticizers from pharmaceutical samples

For the first time, this research presents the synthesis procedure and analytical application of Ni-MOF-I magnetic composite. The synthesis method was green and done in an aqueous medium. The composite was employed as an adsorbent in a magnetic dispersive solid phase extraction process followed by dispersive liquid–liquid microextraction for the extraction and preconcentration of some plasticizers from pharmaceutical samples stored in plastic containers. The Ni-MOF-I magnetic composite was characterized by applying Fourier transform infrared spectrophotometry, vibrating sample magnetometry, scanning electron microscopy, energy-dispersive X-ray, X-ray diffraction, and nitrogen adsorption/desorption analyses. For operating the extraction procedure, initially, the plasticizers were adsorbed onto the adsorbent particles by vortexing. Then, the plasticizers were desorbed from the adsorbent surface using a mL volume of 2-proponal. Subsequently, the obtained eluate phase was mixed with a mixture of 1,2-dibromoethane and 1,1,2-trichloroethane and then injected into deionized water using a glass syringe. Afterward, centrifugation was done to isolate the extractant from the aqueous phase. Eventually, one microliter of the sedimented phase was injected into gas chromatography-flame ionization detection. Acceptable analytical results such as high enrichment factors (355–415) and extraction recoveries (71–83 %), low limits of quantification (0.76–1.08 μg L−1) and detection (0.23–0.33 μg L−1), wide linear ranges (1.08–300 μg L−1), and satisfactory relative standard deviation values of 4.0–6.3 % (intra-day precision, n = 5) and 4.9–7.4 % (inter-day precision, n = 5) were achieved. The suggested procedure was used as a productive analytical method based on the Ni-MOF-I magnetic composite for the extraction and determination of some plasticizers from different pharmaceutical samples filled in plastic containers. Elimination of centrifugation, using 2-propanol as a green desorption/disperser solvent, detection of di-(2-ethylhexyl) phthalate in boric acid alcohol drop, and applying µL-level of the extraction solvent are the advantages of this proposed method.

Mold Fungal Resistance of Loose-Fill Thermal Insulation Materials Based on Processed Wheat Straw, Corn Stalk and Reed.

The present study evaluates the mold fungal resistance of newly developed loose-fill thermal insulation materials made of wheat straw, corn stalk and water reed. Three distinct techniques for the processing of raw materials were used: mechanical crushing (Raw, ≤20 mm), thermo-mechanical pulping (TMP) with 4% NaOH and steam explosion pulping (SEP). An admixture of boric acid (8%) and tetraborate (7%) was applied to all processed substrates due to their anti-fungal properties. The fourth sample group was prepared from SEP substrates without added fungicide (SEP*) as control. Samples from all treatments were separately inoculated by five different fungal species and incubated in darkness for 28 days at 28 °C and RH > 90%. The highest resistance to the colonization of mold fungi was achieved by TMP and SEP processing, coupled with the addition of boric acid and tetraborate, where molds infested only around 35% to 40% of the inoculated sample area. The lowest mold fungi resistance was detected for the Raw and SEP* samples, each ~75%; they were affected by rich amount of accessible nutrients, suggesting that boric acid and tetraborate additives alone did not prevent mold fungal growth as effectively as in combination with TMP and SEP treatments. Together, the achieved fungal colonization scores after combined fungicide and pulping treatments are very promising for the application of tested renewable materials in the future development of thermal insulation products.

Monitoring of Medical Wastewater by Sensitive, Convenient, and Low-Cost Determination of Small Extracellular Vesicles Using a Glycosyl-Imprinted Sensor.

The monitoring of small extracellular vesicles (sEVs) in medical waste is of great significance for the prevention of the spread of infectious diseases and the treatment of environmental pollutants in medical waste. Highly sensitive and selective detection methods are urgently needed due to the low content of sEVs in waste samples and the complex sample composition. Herein, a glycosyl-imprinted electrochemical sensor was constructed and a novel strategy for rapid, sensitive, and selective sEVs detection was proposed. The characteristic trisaccharide at the end of the glycosyl chain of the glycoprotein carried on the surface of the sEVs was used as the template molecule. The glycosyl-imprinted polymer films was then prepared by electropolymerization with o-phenylenediamine (o-PD) and 3-aminophenylboronic acid (m-APBA) as functional monomers. sEVs were captured by the imprinted cavities through the recognition and adsorption of glycosyl chains of glycoproteins on sEVs. The m-APBA molecule also acted as a signal probe and was then attached on the immobilized glycoprotein on the surface of sEVs by boric acid affinity. The electrochemical signal of m-APBA was amplificated due to the abundant glycoproteins on the surface of sEVs. The detection range of the sensor was 2.1 × 104 to 8.7 × 107 particles/mL, and the limit of detection was 1.7 × 104 particles/mL. The sensor was then applied to the determination of sEVs in medical wastewater and urine, which showed good selectivity, low detection cost, and good sensitivity.

Boric Acid Affects the Expression of DNA Double-Strand Break Repair Factors in A549 Cells and A549 Cancer Stem Cells: An In Vitro Study.

DNA double-strand break (DSB) repair genes interact with tumor stemness- and resistance-associated processes in cancer stem cells (CSCs). Therefore, targeting DNA DSB genes in cancer treatment is important for the CSC phenotype. Although the anti-cancer effect of boric acid (BA) has been studied, its effect on DNA DSB is unclear. Moreover, no studies investigate BA's effects on DNA DSB of lung cancer stem cells (LC-SCs). To fill the gap, we aimed to assess the effects of BA on A549 cancer stem cells. CSCs were isolated from human non-small cell lung cancer cells (A549) and characterized by flow cytometry. Different concentrations of BA (at doses ranging from 1 to 100mM) were applied to cancer stem cells. Cytotoxic activities were determined using the cell viability assay (MTT assay) at 24 and 48h. Expression levels ofDNA DSB genes that BRCA1, BRCA2, RAD51, KU70/80, ATM, and XRCC4 were evaluated by RT-qPCR. Additionally, immunofluorescence staining analysis was exploited forcaspase-3 and E-cadherin. ATM expression increased significantly (p < 0.001). No significant change was observed in the expression of other genes. Moreover, BA up-regulated caspase-3 and E-cadherin expression. Consequently, we can say thatBA affects DNA DSB and the apoptotic abilities of LC-SCs.

Ammonia Capturing Capacity of Biochar and Kaolinite

Emission of ammonia from poultry litter has numerous negative impacts on poultry, poultry house workers and the environment. When applied as a litter amendment, acidified biochar (ABC) and Kaolinite are reported to lower the emission of ammonia. Apart from reducing ammonia formation, both amendments have a capacity to capture ammonia before being released into the environment. However, capacity of those materials to capture ammonia has not been estimated. The objective of this study was to determine the ammonia capturing capacity of ABC, kaolinite and three different mixtures of them; 75% Kaolinite and 25% ABC, 50% kaolinite and 50% ABC and 25% kaolinite, 75% ABC. Each of the five amendment mixture was tested in five separate completely randomized design experiments. Poultry litter samples were incubated in ten sealed-conical flasks; each fitted with flexible tubes through which emitting ammonia was conveyed to another sealed-flask containing either a known weight of amendment (five replicate flasks) or Styrofoam; control (five replicate flasks). The weight of the amendment or Styrofoam was adjusted to have same volume of material in flasks. A flexible tube originating from the second flask was connected to another sealed-flask containing a boric acid solution so that ammonia that has not been captured by the amendment or Styrofoam in the second flask is captured. A set of tubes originating from each of the ten boric acid flasks were fitted to a vacuum pump.N content, pH, dry matter percentage of the litter before and after the incubation and the amount of N captured by the boric acid were determined. The difference between N released and that captured by the boric acid solution was considered to be captured by the material added to the second flask. Though assumed to have no capacity to capture ammonia, in all five experiments, Styrofoam reported significantly higher ammonia capturing capacity compared to respective amendments. Ammonia capturing capacity of Styrofoam was as high as 1.24g/100g/hr while that of ABC and Kaolinite were 0.40g/100g/hr and 0.14g/100g/hr), respectively. In all five experiments, the percentages of ammonia captured (of the total released during incubation) were not significantly different between tested amendments and the Styrofoam. Percentage capture of ammonia by ABC, Kaolinite and Styrofoam were 91%, 83% and 84%, respectively. The study concludes that acidified biochar, Kaolinite and Styrofoam have capacity to capture ammonia releasing from poultry litter. Further studies are needed to understand the nature of capturing. &#x0D; Keywords: Ammonia, Biochar, Kaolinite, Litter, Poultry

Knock-Out Mutatıon of Cat2 Drastıcally Reduced The Melatonın-Medıated Resıstance to Boron Toxıcıty in Arabıdopsıs thalıana

The role of catalase in resistance to boron toxicity after melatonin application (MEL) was investigated in Arabidopsis thaliana plants. Col-0 and cat2-2 plants were exposed to 50 μM MEL followed by boron toxicity (BT) in a medium containing 10 mM H 3BO 3. Pigment loss and accordingly chlorosis were reduced by melatonin under BT conditions, while they were more prominent in cat2-2 mutants. Moreover, TBARS and H 2O 2 contents, which increased due to BT, decreased as a result of melatonin application and the levels of these parameters in cat2-2 mutants were higher than the values in Col-0. Antioxidant enzyme activity of SOD and SOD1 gen transcript were induced by MEL under BT. Conversely, APX4, PER10 and CAT1 transcripts were down-regulated by MEL under BT. In addition, antioxidant enzyme activities and their transcript levels were lower than those of Col-0. Thus, we suggested that MEL scavenged ROS directly under BT. Melatonin also reduced the accumulation of boric acid in leaf tissues of Col-0, but not cat2-2. Finally, even though melatonin application provided a degree of endurance, the cat2 mutation resulted in increased sensitivity to BT.