Papers by Keyword: Boric Acid

Abstract: Dross formation during the melting of twitch aluminium scrap using boric acid washing method, was investigated employing a Taguchi-based approach. The study aimed to analyse the impact of different treatment durations with a 1M concentration of boric acid on dross formation characteristics. Experimental trials involved treating twitch aluminium scrap samples with boric acid solutions for 15 to 60 minutes. Subsequently, dross formation characteristics were analysed using statistical techniques based on Taguchi analysis. Results unveiled significant variations in dross formation among treatment durations, indicating that longer treatment times led to decreased dross formation, particularly notable beyond the 30-minute mark. Taguchi's analysis confirmed the significance of treatment duration on dross formation, underscoring the effectiveness of the boric acid washing method in reducing dross formation during twitch aluminium scrap melting. This study offers valuable insights into optimising the boric acid washing method to diminish dross formation during twitch aluminium scrap melting, thereby enhancing efficiency and quality in aluminium recycling processes. Notably, the aim of the research systematically investigate the influence of treatment duration with a 1M concentration of boric acid on dross formation characteristics, providing practical guidance for implementing the boric acid washing method in industrial settings. Keywords: Dross, twitch aluminium scrap, boric acid, Taguchi analysis, recycling, waste management.

Abstract: This paper aimed at studying the influence of additive material boric acid in eco-friendly fired clay tiles. It is used as additive material by mixing with rice husk ash (RHA), brown glass cullet (BGC), local clay (LC), and sediment soil (SS). Effects of boric acid on the physical properties of ceramic bodies were investigated. The texture of specimen by utilizing waste materials was also studied. Mixture formulations consisted of 60% BGC, 10% RHA, 0-30% LC, and 0-30% SS with varying boric acid addition of 0-2%. Specimens were formed by uniaxial pressing with 100 bars, fired at 850 and 900°C, heating rate 100°C/h, and soaked for 1 h. The results showed that adding boric acid up to 2% had increased the flexural strength and decreased the water absorption of these specimens when fired at 850°C. On the contrary, the effects of adding boric acid fired at 900°C had decreased flexural strength and increased water absorption that showed the phenomenon of expanding specimens. However, the optimal formula of these clay tiles both fired at 850 and 900°C have passed the Thai Industrial Standards (TIS 2508-2555); Type BIII. Scanning electron microscope should they that microstructure characterization was in the glassy crystalline phase was found in high flexural strength specimens. In summary, exploiting boric acid can improve the physical properties of specimens with a low firing temperature, and fired clay wall tiles can be developed in this study. They can be identified as an environmentally eco-friendly building product.

Abstract: We tested stability of 43 selective sorbents, covering the widest range of functional groups, efficiency of sorption, method of production, and which are theoretically useful for sorption of cesium, strontium, cobalt, arsenic and actinoids. We present 3 of them: A = TiO₂, B = Al₂O₃ and C = MxH(TiO)₄(SiO4)₃ . z H₂O. In first testing, sorbents were exposed to the model solution of boric acid for 168 hours, in which they were mixed in a closed container with a rotator. After the exposure, sorbent solutions were filtered and analysed by spectroscopic techniques (Infrared Spectroscopy (IR), Raman Spectroscopy (RS) and newly by Scanning Electron Microscopy (SEM), combined with Energy Dispersive Spectroscopy (EDS)). Exposed spectra were compared with spectra of new, non-exposed sorbents. In second testing, sorbents were exposed to gamma radiation for 12 days with total dose 666 ± 43 kGy, produced by cobalt bomb and analysed by same techniques. The aim of our testing was to find out how sorbents behave in model boric acid solution and what effect has the gamma radiation on sorbent spectra and to analyse sorbents by SEM with EDX.

Abstract: This paper evaluates the tribological behavior of borided AISI 316L steel after being exposed to a secondary process to form a thin film of a solid lubricant. The process known as Short Annealing Process (SAP), allows creating a thin film of boric acid (H₃BO₃) on the surface of metallic materials previously exposed to boriding. The H₃BO₃ film acts like solid lubricant due to its lamellar crystalline structure. First samples of AISI 316L were exposed to boriding to temperatures of 875, 925 and 975 °C during 2, 4 and 6 h each temperature. Then, samples were heated to 750 °C during 5 min and cooled to room temperature at 60 % of Relative Humidity. The tribological behavior of the treated samples was evaluated by pin-on-disk test equipped with friction coefficient measurement system. Samples were characterized by Scanning Electron Microscopy, X-Ray Diffraction and Vickers microhardness test. The results showed an evident influence of the experimental parameters on the thickness of the boride layers and their mechanical properties. The layer ́s thickness was ranged from 10.51±0.71 to 51.57±5.12 μm. The hardness of the coatings was increased from 264 to 1685 HV. Finally, the Coefficient of Friction was diminished from values of 0.7 for the as-received material to 0.29 for the borided samples and to 0.06 for those after SAP, which indicates that the post-treatment SAP enhances the tribological properties of the biomedical steel.

Abstract: Turning is a mostly used metal removal process in the engineering industry that involves generation of high temperature and cutting forces. Lubrication becomes critical to minimize the effects of this temperature and forces on cutting tool and workpiece. Development of lubricants that are environmental is acquiring importance. For this, a specific study on the application of Minimum Quantity Lubricants as lubricating oil in turning operation is working on. In the present work a specific study on the application of nanosolid boric acid with titanium dioxide (μm) suspended in lubricating oil in turning of EN24steel with carbide tool. SAE-40 is taken as base lubricants and boric acid solid lubricant of (50, 60 80, 538nm) particles size and titanium dioxide (100μm) with different weight percentages taken as suspensions. Variations in cutting forces, tool temperatures, and surface roughness are studied. For this Boric acid nanoparticle were prepared by using High Energy Ball Milling. Ball milling which was carried out for the total duration of 15 hours. The sample was taken out after every 5 hours of milling for characterizing. The nanostructured boric acid particle size measurement was done by X-Ray Diffractometer which was supported by the XRD Scherer’s formula. It was found that the particle size got reduced from 538nm to 63nm for the period of 15 hrs. In present work, the obtained results were predicted by using Regression analysis method for the prediction of output parameters of the lathe machining process is modelled using two input variable parameters such as particle size of boric acid (nm) and the weight percentage of titanium dioxide (μm). Then the model predictions are compared with a set of reliable experimental data available, and it is found So that proposed Regulation analysis gives the results which are well in agreement with experimental results. Keywords: Turn machining, SAE-40 oil, Boric acid, Titanium dioxide, Minimum Quantity Lubrication (MQL), Regression analysis

Abstract: The results of hand calculation of boric acid accumulation in the core in a new generation WWER-TOI reactor in case of LOCA are presented. Variants of reducing the H₃BO₃ concentration in the HA-3 system down to 1, 2, 4 and 8 g/kg are considered. The mass of boric acid deposits on the core internals depending on the value of boric acid concentration in the HA-3 system is determined. The obtained results allow concluding that the accumulation and crystallization of boric acid in the core is possible.

Abstract: The hydrophobicity of starch/PVA blend was improved by crosslinking with boric acid. It was found that the swelling ratio of the boric acid modified starch/PVA matrix decreased as function of boric acid concentration. FTIR spectra and SEM images demonstrated that the urea had been encapsulated in polymer matrix successfully. The urea release characteristic was explained with respect to the swelling ratio and crosslinking density of polymer matrix. In addition, the matrix displayed a good barrier for controlling the release rate of urea from pellet.

Abstract: Due to rapid growing of nanotechnology, it is currently being used in many areas including biotechnology, electronics, drug delivery systems, cosmetics, material science and biosensors. Oxidative stress is considered as main cause behind the toxicity of nanoparticles (NPs). Recent reports indicate that boron is effective in protecting cells or organisms against oxidative damages by enhancing antioxidant defense mechanisms. However, protective role of boron compounds in nanotoxicity is not investigated yet. Therefore we assessed the potential protective role of boric acid (BA) and borax (BX) against the toxic responses of nano-Fe₃O₄ particles (IO NPs) in cultured human whole blood cells. Our results showed that IO NPs induced genotoxicity in human lymphocytes demonstrated by sister chromatid exchange (SCE) and 8-hydroxy-2′-deoxyguanosine (8-OH-dG) assays. Again, IO NPs caused decreases of total antioxidant capacity (TAC) and decreases of total oxidative stress (TOS) levels in vitro. Co-application of boric acid and borax (2.5 to 10 ppm) into the cell cultures significantly ameliorated genotoxicity and oxidative stress caused by IO NPs. In a conclusion, this study is the first report revealing that BA and BX significantly protected human blood cells from the toxicity of IO NPs, which is mediated through the generation of oxidative stress and depletion of antioxidant capacity.

Abstract: Ammonia borane (NH3BH3, AB) is an excellent source of hydrogen(19.6 wt %) for fuel cell applications. In this paper, pure ammonia borane is successfully prepared by using amino complex for ammonia complex Ag(NH3)2Cl as new ammonia source, and sodium borohydride (NaBH4) as boron source. The composition and constitution of the products are measured by XRD and FT-IR. The thermolysis of ammonia borane is significant for its practical application. Boric acid plays a role in improving ammonia borane hydrogen performance. The effects of different mass ratio of boric acid and ammonia borane on dehydrogenation are tested by XRD, TG/DTA and TPD-MS. The results show that boric acid can decrease the first level dehydrogenation temperature of ammonia borane decrease to about 85°C (working temperature of PEMFC). What’s more, the onset temperature of AB’s thermolysis can decrease to about 60°C when the mass ratio of ammonia borane and boric acid is equal to 3:1. This makes ammonia borane be more suitable for the application in on-board hydrogen storage system.

Abstract: With boron trifluoride methanol complex as raw material, the hydrolysis reaction of boron trifluoride was used to prepare the boric acid. The addition of calcium carbonate is aim to remove the hydrogen fluoride generated in the reaction process, The ultimate objective is making the material being the product of boric acid maximum. Reaction time (T), the ratio of raw materials (molar ratio) and the amount of water were investigated in the influence of the purity and yield of boric acid. The conductivity of mixed solution was determined by conductivity meter, the results determines the end point of the reaction for 20 hours, the optimum solid-liquid ratio is three to one, the amount of water for each mole of boron trifluoride is corresponding 2L distilled water. Product of boric acid yield was 96.26%, the purity was 95.34%.