Influence of the Pyrotechnic Igniter Composition Aging on Explosion Parameters of Dispersed Dusts

A commercially available pyrotechnic igniter was used according to the EN 14034 and ASTM E1226a Standards to study the explosiveness of dispersed dusts. Its pyrotechnic composition consists of 1.2 g of zirconium (40% wt.), barium peroxide (30% wt.) and barium nitrate (30% wt.). The energy released during the combustion of that amount of composition is 5 kJ. The article investigates the influence of aging of the pyrotechnic composition in the igniter on its initiation parameters. In the study, igniters of different years from date of manufacture were used: Igniter 1, manufactured in 2021 (less than 1 year from date of manufacture), and Igniter 2 (more than 2 years from date of manufacture). The study was performed in the KV 150M2 explosion chamber with a volume of 365 L and the 20 L sphere chamber with a volume of 20 L. A standard sample of Lycopodium clavatum was used in the KV 150M2 explosion chamber. Magnesium and benzoic acid were used as the samples in the 20 L sphere explosion chamber. The experiment showed that the explosion pressure Pmax of the igniter with more than 2 years from date of manufacture decreased by up to 10%, while the value of the explosion constant Kst decreased by up to 40%. The attained results proved that aging of igniters affects their explosion parameters and measurement accuracy.

Raman random lasing in Ba(NO3)2 powder

Random lasing in Raman active material – barium nitrate powder – has been registered in two temporal regimes: nanosecond and picosecond. Stimulated Raman scattering (SRS) in Ba(NO3)2 for picosecond excitation has been shown to have much lower threshold and spectrum containing more components than for nanosecond excitation opposite to the case of a bulk medium. In picosecond regime SRS intensity increased with temperature decreasing and redistributed in favor of the higher order components. SRS pulse duration in picosecond regime was estimated to be in the range 16.5-22 ps. High conversion efficiency of SRS in barium nitrate powder in picosecond regime and its larger stability under laser impact than for bulk samples gives possibility to use it as an active material in Raman converters.

EFFECT OF NUTRIENTS ON CELLULOLYTIC AND PECTOLYTIC ENZYME PRODUCTION OF ALTERNARIA ALTERNATA A LEAF SPOT PATHOGEN OF TEAK (TECTONA GRANDIS L.F.)

Alternaria alternata is a potential pathogen of Tectona grandis L.f., was isolated from diseased Tectona grandis L.f. leaves from Nashik and used for the present study. Pathogen was grown on the Czapek-Dox liquid medium substituting or adding different carbon, nitrogen to study cellulolytic and pectolytic enzyme production and total phenol production. The activity of enzyme was observed on the 8th day of incubation period. A great extent of growth variation was observed on different carbon, nitrogen. Among the carbon source) the maximum loss in percentage viscosity maximum in lactose and fructose. While minimum in glucose and dextrose as compared to other nitrogen source. From nitrogen source the cellulolytic enzyme activity was maximum in control and cobalt nitrate followed by similar activity in potassium nitrate and nickel nitrate. While minimum cellulolytic enzyme activity was seen in barium nitrate.. Variation was also observe in pectolytic enzyme activity. the cellulolytic enzyme activity was maximum in glucose while minimum in dextrose as compared to lactose, control and fructose.. From nitrogen source the cellulose activity was maximum in potasium nitrate and minimum in cobalt nitrate as compared to nickel nitrate, barium nitrate and control.

Effect of Nutrients on Biomass Production of Helminthosporium Tetramera A Leaf Spot Pathogen of Sugarcane (Saccharum Officinarum)

: Helminthosporium tetramera was a pathogen of Saccharum Officinarum, was isolated from diseased Saccharum Officinarum, leaves from Nashik district and used for the present study. Pathogen was grown on the Czapek-Dox liquid medium substituting or adding different carbon, nitrogen to study biomass production. The growth as dry mycelial biomass was observed on the 8th day of incubation period. A grate extent of growth variation was observed on different carbon, nitrogen. Among the carbon source, fructose shows maximum biomass while glucose with minimum biomass. From nitrogen source cobalt nitrate and barium nitrate shows maximum and control condition with minimum biomass was recorded.

Solar Light-Driven Photocatalysis Using BaFe2O4/rGO for Chlorhexidine Digluconate Contaminated Water: Comparison With Artificial UV and Visible Light-Mediated Photocatalysis

Synthesis and characterization of dual functioning material is an effective approach for promotion of organic pollutant degradation through adsorption as well as photocatalysis. Herein, graphene oxide modified by addition of barium nitrate and iron to construct smooth sheet-like structure (BaFe2O4/rGO) for removal of Chlorhexidine Digluconate (CHD). Compare with GO (75.69% -UV-light ;88.17%-visible-light), BaFe2O4/rGO showed significant adsorption-photocatalysis effect under visible-light (93.95%) than UV-light (78.17%). The introduction of barium nitrate and iron into graphene oxide led to smooth porous structure with increased surface area (93.66 m2 g-1), which resulted in large number of adsorption active site and great photocatalytic activity with efficient charge separation. Although, catalysts did not mineralize CHD completely, but the parent compound mineralized to some extent, which was confirmed by the TOC measurement and UV254 absorbance variation. In addition, toxicity of degraded products was analyzed by bacterial susceptibility test on Bacillus cereus DPAML065 suggested that nontoxic byproducts of CHD formed, which led to their safe disposal. Based on the identified transformed products, the possible degradation pathway was proposed. Batch studies demonstrated that BaFe2O4/rGO is highly photoactive based on reaction rate constant (R2=0.984), where the kinetics data was well-fitted using the pseudo-first order. Moreover, efficiency of catalysts was examined under solar light to achieve the sustainability.

ELECTROCHEMICAL SYNTHESIS OF DISPERSED BARIUM FERRITE USING ANODIC DISSOLUTION OF METAL

The process of anodic dissolution of iron (purity not less than 99%) in aqueous solutions of barium chloride, barium nitrate and binary electrolytes under galvanostatic conditions and by registration of potentiodynamic polarization curves was investigated. The influence of solution composition and concentration and the value of applied direct current on the intensity of anodic oxidation of iron was shown. It was revealed that the oxidation rate of metal in binary electrolytes containing barium chloride and barium nitrate is comparable with the intensity of anodic dissolution in a solution based on barium chloride. It was found that anodic polarization curve in solutions containing BaCl2 and Ba(NO3)2 has a complex form typical of passivated metals. There is a clear maximum of anodic oxidation current on this curve, as well as in barium nitrate solution, however the peak height is much higher (50-150 times). A method for the synthesis of dispersed barium ferrite, based on the anodic oxidation of iron in aqueous barium chloride and barium nitrate solutions with subsequent thermal treatment of the product of electrochemical dissolution was suggested. The phase and elemental composition and structural characteristics of obtained precursor and ferrite samples were examined using X-ray phase analysis. The influence of the heat treatment mode on the phase composition of the synthesized samples is shown. It is found that electrolysis with a soluble iron electrode using direct anode current in 0.05M BaCl2 + 0.5M Ba(NO3)2 solution and subsequent thermal treatment of the dissolution product at 1200 ° C provide the formation of dispersed system, whose phase composition is predominantly Ba0.87Fe11.08O17.15 (74%) and BaFe2O4 (17%).

From BaCl2 to Ba(NO3)Cl: Birefringence Enhanced Significantly Deriving from the π-conjugated [NO3]

The first chlorine barium nitrate, Ba(NO3)Cl, has been synthesized via mild hydrothermal method. Its structure features ABW-type topology (BaCl-ABW) framework which can be considered as the stacking of honeycomb-like sheets....

Structure and properties of nanocrystalline tetragonal BaTiO3 prepared by combustion solid state synthesis

Barium titanate (BaTiO3) attracts high scientific and technological attention due to good dielectric and electromechanical properties. Although BaTiO3 is one of the most frequently investigated ferroelectric materials, the need for finding new and/or improved synthesis methods of this material still exists. In this paper, a novel, mild synthesis route for producing tetragonal BaTiO3 from barium nitrate and Ti-oxalate precursor is presented. Morphology of the prepared and subsequently sintered BaTiO3 was determined by SEM. Particle size distribution of the as prepared powder was monitored by the laser diffraction. The phase composition, structure and lattice dynamics were investigated by XRD and Raman spectroscopy. Finally, dielectric parameters were determined in the temperature range from 30 to 180?C, and within a variety of frequencies. Curie temperature was detected at 130?C.