Barium Hydroxide Research Articles

Well-Established Biodegradation Tests Used Biogenously Evolved Carbon Dioxide as an Analytical Parameter to Determine the Ultimate Biodegradability of Metalworking Fluids Measured by the Change of Absorption Solution Conductivity

Nowadays, there exist a few standardized tests in poor soluble substances ready biodegradability measurement. There are possibilities in evaluate the degradation by the O2 consumption or by CO2 releasing. Tests for O2 consumption are very stringent in keep the constant temperature because of the pressure which is the main parameter in O2 consumption calculating. On the other hand CO2 releasing test are complicated and discontinue because of the measuring by the titration methods. In present there is a possibility to measure CO2 produced by microbial activity during the substance degradation by the gaseous sensors. We were realized preliminary studies in continual measuring of evolved CO2 in biodegradability test of metalworking fluid Syntilo 81 BF by the conductivity measurement of absorption solution of barium hydroxide as it was described in [3,5].

Synthesis and evaluation of new chalcones, derived pyrazoline and cyclohexenone derivatives as potent antimicrobial, antitubercular and antileishmanial agents

A series of chalcones (1–8) were prepared by Claisen–Schmidt condensation of 3-nitroacetophenone with various aldehydes. These chalcones on cyclization with hydrazine hydrate in the presence of glacial acetic acid, hydrazine hydrate in absolute ethanol and ethyl acetoacetate in the presence of barium hydroxide gave corresponding N-acetyl pyrazolines (9–16), N-unsubstituted pyrazolines (17–19) and cyclohexenone derivatives (20–22). All the synthesized compounds were evaluated for their in vitro antibacterial and antifungal activity by using broth microdilution method, and many compounds showed promising activity against various tested bacteria and fungi. Among various tested compounds, 16 and 19 exhibited strongest activities against Streptococcus pyogenes and Pseudomonas aeruginosa; both have MIC value of 25 μg/mL, which is fourfold greater than the standard drug. Many compounds showed good activity against Candida albican. Analogs 11, 12, 15–17 and 19 displayed two- to fivefold greater activity against C. albican as compared to the standard drug. Results of antitubercular evaluation revealed that compounds 4 and 19 displayed strong antimycobacterial activity against H37Rv having MIC of 25 and 62.5 μg/mL, respectively. All analogs were found to be inactive against Leishmania braziliensis except analogs 4 and 5 which exhibited strong leishmanicidal activity against Leishmania promastigotes with IC50 values of 9.3 and 8.9 μg/mL, respectively.

Synthesis of Tetragonal BaTiO<sub>3</sub> Powders via Alkoxide Method Assisted by Diethanolamine

The BaTiO3 precursor was prepared by alkoxide method, in which barium hydroxide octahydrate and butyl titanate were chosen as the Ba and Ti sources, and diethanolamine (DEA) as the polymerizing agent respectively. In order to determine the synthesis parameters of the target product, the phase transition process of the precursor with temperature increasing was investigated by TG-DTA. The effect of calcination temperature, the dosage of DEA and calcination time on the phase compositions and crystal structure of the synthesized samples were investigated by XRD. The results indicate that DEA can promote the formation of tetragonal BaTiO3 effectively, and the high-purity tetragonal BaTiO3 was obtained by heat treatment of the precursor at 1100°C for 3h with 1mL DEA dosage.

Draw solute recovery by metathesis precipitation in forward osmosis desalination

ABSTRACT Forward osmosis (FO) is a natural osmosis process that is under investigation as a potential means of desalination, wastewater treatment, and energy production. This article presents forward osmosis desalination study on a commercial cellulose acetate membrane. The membrane was tested for high feed concentrations ranging from typical brackish water concentration to seawater concentration. For energy-efficient recovery of product water, a 240,000 ppm of MgSO4 draw solution was used. The membrane achieved an average water flux of 4.06 and 0.60 L/m2 h in case of brackish and seawater, respectively. Pure product water with a salt content of 350 ppm was recovered from the diluted MgSO4 draw solution by reaction with stoichiometric amount of barium hydroxide to remove the soluble draw solute as magnesium hydroxide and barium sulfate precipitates.

Arabinoxylan from finger millet (Eleusine coracana, v. Indaf 15) bran: Purification and characterization

Water unextractable portion from finger millet bran was sequentially extracted with saturated barium hydroxide (BE) and 1M potassium hydroxide (KE) solutions. They consisted preponderantly of arabinose and xylose in different ratios. Ferulic, caffeic, coumaric and vanillic acids were identified as major bound phenolic acids. BE and KE were purified on DEAE-cellulose column by eluting successively with different eluants. The major fractions (0.1M ammonium carbonate) were resolved into one (BE) and two subfractions (KE1 and KE2) respectively on Sephacryl S-400 gel filtration chromatography and their homogeneity was ascertained by gel filtration, cellulose acetate membrane electrophoresis and capillary electrophoresis. The average molecular weight of BE, KE1 and KE2 were found to be 430, 1028 and 40kDa respectively. The structural elucidation of the purified polysaccharides by 1H and 13C NMR analysis indicated the backbone to be 1,4-β-d-linked xylan with substitution mainly at O-2 or O-3 and/or both by α-l-arabinose residues.

Preparation of BaZrO<sub>3</sub> Nanocrystals at Low Temperature

Barium zirconate (BaZrO3) was prepared by the composite-hydroxide-mediated (CHM) approach at low temperature. The CHM method is based on chemical reactions of materials in the eutectic hydroxide melt. In this method, the eutectic point at an sodium hydroxide (NaOH) : potassium hydroxide (KOH) molar ratio of 51.5 : 48.5 is about 165°C. In the present work, the low-temperature preparation and morphology of BaZrO3 nanocrystals were investigated. Zirconium tetra-n-butoxide ((CH3CH2CH2CH2O)4Zr) and/or zirconium dioxide (ZrO2) were used as a zirconium source. X-ray diffraction measurements confirmed that the BaZrO3 had a perovskite structure. Barium hydroxide (Ba (OH)2) was used as a barium source. BaZrO3 nanoparticles were obtained when (CH3CH2CH2CH2O)4Zr was used as a raw material. On the other hand, BaZrO3 nanocubes were formed when ZrO2 was used as a raw material. Scanning electron microscopy and transmission electron microscopy observations indicated that BaZrO3 nanocrystals were formed.

Phosphopeptide enrichment by covalent chromatography after derivatization of protein digests immobilized on reversed-phase supports.

A rugged sample-preparation method for comprehensive affinity enrichment of phosphopeptides from protein digests has been developed. The method uses a series of chemical reactions to incorporate efficiently and specifically a thiol-functionalized affinity tag into the analyte by barium hydroxide catalyzed β-elimination with Michael addition using 2-aminoethanethiol as nucleophile and subsequent thiolation of the resulting amino group with sulfosuccinimidyl-2-(biotinamido) ethyl-1,3-dithiopropionate. Gentle oxidation of cysteine residues, followed by acetylation of α- and ε-amino groups before these reactions, ensured selectivity of reversible capture of the modified phosphopeptides by covalent chromatography on activated thiol sepharose. The use of C18 reversed-phase supports as a miniaturized reaction bed facilitated optimization of the individual modification steps for throughput and completeness of derivatization. Reagents were exchanged directly on the supports, eliminating sample transfer between the reaction steps and thus, allowing the immobilized analyte to be carried through the multistep reaction scheme with minimal sample loss. The use of this sample-preparation method for phosphopeptide enrichment was demonstrated with low-level amounts of in-gel-digested protein. As applied to tryptic digests of α-S1- and β-casein, the method enabled the enrichment and detection of the phosphorylated peptides contained in the mixture, including the tetraphosphorylated species of β-casein, which has escaped chemical procedures reported previously. The isolates proved highly suitable for mapping the sites of phosphorylation by collisionally induced dissociation. β-Elimination, with consecutive Michael addition, expanded the use of the solid-phase-based enrichment strategy to phosphothreonyl peptides and to phosphoseryl/phosphothreonyl peptides derived from proline-directed kinase substrates and to their O-sulfono- and O-linked β-N-acetylglucosamine (O-GlcNAc)-modified counterparts. Solid-phase enzymatic dephosphorylation proved to be a viable tool to condition O-GlcNAcylated peptide in mixtures with phosphopeptides for selective affinity purification. Acetylation, as an integral step of the sample-preparation method, precluded reduction in recovery of the thiolation substrate caused by intrapeptide lysine-dehydroalanine cross-link formation. The solid-phase analytical platform provides robustness and simplicity of operation using equipment readily available in most biological laboratories and is expected to accommodate additional chemistries to expand the scope of solid-phase serial derivatization for protein structural characterization.

Investigation of dielectric properties of newly prepared β-phase polyvinylidene fluoride–barium titanate nanocomposite films

In the present investigation nanocomposite films were prepared by solution casting method with β-phase Polyvinylidene fluoride (PVDF) as a polymer matrix and barium titanate as a filler which was prepared using Ti(IV) triethanolaminato isopropoxide and hydrated barium hydroxide as precursors and tetra methyl ammonium hydroxide (TMAH) as a base. The XRD, FTIR, SEM shows that the fillers in nanocomposites were homogeneous and well dispersed. The dielectric constant and dissipation factors studied in the experimental range of nanocomposites were found to be around 7 and 0.03 respectively which may be very good material to be explored for novel capacitors.

Sulphate removal from sodium sulphate-rich brine and recovery of barium as a barium salt mixture

Sulphate removal from sodium sulphate-rich brine using barium hydroxide and recovery of the barium salts has been investigated. The sodium sulphate-rich brine treated with different dosages of barium hydroxide to precipitate barium sulphate showed sulphate removal from 13.5 g/L to less than 400 mg/L over 60 min using a barium to sulphate molar ratio of 1.1. The thermal conversion of precipitated barium sulphate to barium sulphide achieved a conversion yield of 85% using coal as both a reducing agent and an energy source. The recovery of a pure mixture of barium salts from barium sulphide, which involved dissolution of barium sulphide and reaction with ammonium hydroxide resulted in recovery of a mixture of barium carbonate (62%) and barium hydroxide (38%), which is a critical input raw material for barium salts based acid mine drainage (AMD) desalination technologies. Under alkaline conditions of this barium salt mixture recovery process, ammonia gas is given off, while hydrogen sulfide is retained in solution as bisulfide species, and this provides basis for ammonium hydroxide separation and recovery for reuse, with hydrogen sulfide also recoverable for further industrial applications such as sulfur production by subsequent stripping.

A new low dielectric constant barium titanate - poly (methyl methacrylate) nanocomposite films

In the present investigation, nanocomposite films with poly(methyl methacrylate) (PMMA) as a polymer matrix and barium titanate as a filler were prepared by solution casting method. Barium titanate nano particles were prepared using Ti(IV) triethanolaminato isopropoxide and hydrated barium hydroxide as precursors and tetra methyl ammonium hydroxide (TMAH) as a base. The nanocomposite films were characterized using XRD, FTIR, SEM and dielectric spectroscopy techniques. Dielectric measurements were performed in the frequency range 100 Hz-10 MHz. Dielectric constant of nanocomposites were found to depend on the frequency, the temperature and the filler fraction. Dissipation factors were also influenced by the frequency and the temperature but not much influenced by the filler fractions. The 10 wt% of BT-PMMA nanocomposite had the lowest dielectric constant of 3.58 and dielectric loss tangent of 0.024 at 1MHz and <TEX>$25^{\circ}C$</TEX>. The dielectric mixing model of Modified Lichtenecker showed the close fit to the experimental data.

Miniaturized and green method for determination of chemical oxygen demand using UV-induced oxidation with hydrogen peroxide and single drop microextraction

We report on a green method for the determination of low levels of chemical oxygen demand. It is based on the combination of (a) UV-induced oxidation with hydrogen peroxide, (b) headspace single-drop microextraction with in-drop precipitation, and (c) micro-turbidimetry. The generation of CO2 after photolytic oxidation followed by its sequestration onto a microdrop of barium hydroxide gives rise to a precipitate of barium carbonate which is quantified by turbidimetry. UV-light induced oxidation was studied in the absence and presence of H2O2, ultrasound, and ferrous ion. Determinations of chemical oxygen demand were performed using potassium hydrogen phthalate as a model compound. The optimized method gives a calibration curve that is linear between 3.4 and 20 mg L−1 oxygen. The detection limit was 1.2 mg L−1 of oxygen, and the repeatability (as relative standard deviation) was around 5 %. The method was successfully applied to the determination of chemical oxygen demand in different natural waters and a synthetic wastewater.

Copper sulfate as draw solute in forward osmosis desalination

Copper sulfate is presented as a viable draw solute in forward osmosis (FO) for brackish water desalination. In this study, the osmotic pressure of copper sulfate was calculated as a function of concentration. An investigation into the osmotic pressure revealed that copper sulfate draw solution cannot generate enough osmotic pressure to extract water from seawater feed. A laboratory-scale FO unit utilizing a commercial flat-sheet cellulose acetate membrane was used to desalinate brackish water using 200,000ppm copper sulfate draw solution. An average water flux of 3.57L/m2h was observed. Product water with a salt content of 100ppm was recovered from the diluted copper draw solution without using any energy. The product water was recovered by metathesis precipitation reaction of copper sulfate with barium hydroxide to remove the soluble chemicals as insoluble copper hydroxide and barium sulfate. At the end, copper sulfate draw solution was recovered by the reaction of copper hydroxide with sulfuric acid.

New method for visualization of C-heterochromatin in synaptonemal complex spreads

DAPI staining of the metaphase chromosomes pretreated with barium hydroxide generates a C-like banding pattern. In this work a protocol for visualizing similar pattern at the synaptonemal complex (SC) spreads after immunostaining is suggested. This method was used to visualize centromeric and sex heterochromatin at the SC spreads of guppy fish (Poecilia reticulata Peters, 1859). The efficiency of this method was further confirmed at SC spreads of the northern red-backed vole (Myodes rutilus (Pallas, 1779)), the guinea pig (Cavia porcellus (Linnaeus, 1758)), and the pigmy shrew (Sorex minutus Linnaeus, 1766).

An efficient and eco-friendly synthesis of quinolinyl chalcones under solvent-free conditions at room temperature

A simple, rapid and eco-friendly procedure for the synthesis of quinolinyl chalcones involving grinding of quinoline-3-carbaldehydes and acetophenones with anhydrous barium hydroxide (C-200) at room temperature under solvent-free conditions has been described. The protocol is much more efficient as the reactions are carried out at room temperature, and yields are also quite high, and the use of hazardous chemicals and organic solvents at any stage of the reaction is also avoided.

Acidity Removal and Cesium Catalyst Recovery from Polyol Synthesis Process

In this work, a suitable method for removing the final acidity of the polyol and for recovering cesium hydroxide from polyols synthesis has been developed. Different treatments were performed in order to remove the final acidity of the polyol: adsorption with two different adsorbents (Ambrosol and basic alumina) and ion-exchange with resin Amberlite IRA. Only when the anionic ion-exchange resin was used, was the acidity value decreased until a final value of 0.93 mg KOH/g. In order to recover the cesium, a chemical treatment of the cesium sulfate salt (obtained after the acid neutralization) with barium hydroxide was chosen. Barium hydroxide was added to precipitate the sulfate ion in barium sulfate, and a solution of cesium hydroxide remained. The dissolution of cesium sulfate salt and the amount of precipitating agent were optimized. The technical and economic feasibility of the catalyst recovery process was established.

An arabino(glucurono)xylan isolated from immunomodulatory active hemicellulose fraction of Salvia officinalis L.

From the aerial parts of sage (Salvia officinalis L.) an arabino-(4-O-methyl-glucurono)-xylan (AGX) was isolated by alkaline extraction followed by precipitation with barium hydroxide solution. Polymer was isolated from sage as a light brown polysaccharide material of molecular mass (Mp) 84,000. Compositional analyses of sage AGX revealed xylose (81%), arabinose (10%), glucuronic acid (8%) and small amounts of hexoses (1%). Linkage sugar analyses showed the (1→4)-linked xylopyranosyl backbone with low degree of substitution (9–10%) at O-2 and O-3. Arabinofuranose residues were found as the terminal, 1,3-, 1,5- and 1,3,5-linked. NMR structural analyses of acidic oligomers, generated by partial acidic hydrolysis of AGX, confirmed a substitution of xylose residues by glucuronic acid and its 4-O-methyl derivate at O-2 at an average on every fourteenth xylose residue. NMR and FT-IR measurements, as well as a high negative optical rotation confirmed the β configuration of glycosidic linkages in AGX backbone.

DETERMINATION OF TRACE ANIONS IN HEAVY MATRICES WITH NON-SUPPRESSED ION CHROMATOGRAPHY AFTER MATRIX ELIMINATION

Determination of traces of anions in real samples having thousands fold excess matrix ions of nitrate, sulphate, and lead in samples is described. For the elimination of these matrix ions, simple and conventional procedures are applied. The nitrate matrix was eliminated by simple evaporation by heating of HNO3 sample; sulphate ion of cupracid sample was removed by precipitation with barium hydroxide solution and matrix of lead in lead peroxide sample was removed by loading of lead on commercially available AG 50WX 16 cation exchange resin. The anions of interest were separated by Hamilton PRP × 100 anion column and detected by single-column conductivity detection using high performance liquid chromatography (HPLC). Recovery experiments were employed to verify the accuracy of the proposed methods using standard solution of matrix components for spiking of analyte anions. Application of these methods to determine trace levels of common anions using ion chromatography is demonstrated in real samples.

Universal fractionation of lignin–carbohydrate complexes (LCCs) from lignocellulosic biomass: an example using spruce wood

It is of both theoretical and practical importance to develop a universally applicable approach for the fractionation and sensitive lignin characterization of lignin-carbohydrate complexes (LCCs) from all types of lignocellulosic biomass, both natively and after various types of processing. In the present study, a previously reported fractionation approach that is applicable for eucalyptus (hardwood) and flax (non-wood) was further improved by introducing an additional step of barium hydroxide precipitation to isolate the mannan-enriched LCC (glucomannan-lignin, GML), in order to suit softwood species as well. Spruce wood was used as the softwood sample. As indicated by the recovery yield and composition analysis, all of the lignin was recovered in three LCC fractions: a glucan-enriched fraction (glucan-lignin, GL), a mannan-enriched fraction (GML) and a xylan-enriched fraction (xylan-lignin, XL). All of the LCCs had high molecular masses and were insoluble or barely soluble in a dioxane/water solution. Carbohydrate and lignin signals were observed in (1) H NMR, (13) C CP-MAS NMR and normal- or high-sensitivity 2D HSQC NMR analyses. The carbohydrate and lignin constituents in each LCC fraction are therefore believed to be chemically bonded rather than physically mixed with one another. The three LCC fractions were found to be distinctly different from each other in terms of their lignin structures, as revealed by highly sensitive analyses by thioacidolysis-GC, thioacidolysis-SEC and pyrolysis-GC.

수산화바륨을 이용한 이산화탄소 확산측정법의 개발 및 평가

This study was aimed at developing and evaluating a diffusive sampling method using a barium hydroxide solution as an absorbent for measuring carbon dioxide () in ambient air. The collected concentration was calculated by the change of conductivity resulted in the reaction of and in aqueous solution. The sampling rate for the diffusive sampler was determined 0.218 mL/min, as obtained from the slope of the linear correlation between the mass collected by the diffusive sampler and the time-weighted concentration with the active sampling method. The unexposed blank sampler sealed in aluminium foil-polyethylene laminated packets has remained stable during at least one-month storage period. A good correlation was observed between the diffusive sampler and active sampler with a coefficient of determination of 0.956. This diffusive sampler would be suitable for the indoor concentration monitoring.

Effect of different drying techniques on flowability characteristics and chemical properties of natural carbohydrate-protein Gum from durian fruit seed

BackgroundA natural carbohydrate biopolymer was extracted from the agricultural biomass waste (durian seed). Subsequently, the crude biopolymer was purified by using the saturated barium hydroxide to minimize the impurities. Finally, the effect of different drying techniques on the flow characteristics and functional properties of the purified biopolymer was investigated. The present study elucidated the main functional characteristics such as flow characteristics, water- and oil-holding capacity, solubility, and foaming capacity.ResultsIn most cases except for oven drying, the bulk density decreased, thus increasing the porosity. This might be attributed to the increase in the inter-particle voids of smaller sized particles with larger contact surface areas per unit volume. The current study revealed that oven-dried gum and freeze-dried gum had the highest and lowest compressibility index, thus indicating the weakest and strongest flowability among all samples. In the present work, the freeze-dried gum showed the lowest angle of repose, bulk, tapped and true density. This indicates the highest porosity degree of freeze dried gum among dried seed gums. It also exhibited the highest solubility, and foaming capacity thus providing the most desirable functional properties and flow characteristics among all drying techniques.ConclusionThe present study revealed that freeze drying among all drying techniques provided the most desirable functional properties and flow characteristics for durian seed gum.