Effect Of Initial Temperature Research Articles

The Effect of Mixture Variation and Initial Temperature On the NH2* Thickness of Spherically Propagating Laminar Ammonia Flames

Abstract Interest in ammonia (NH3) in combustion has increased recently as a carbon-free fuel alternative. Understanding its combustion characteristics is crucial. One way to increase knowledge of ammonia combustion is by investigating the flame zone of a laminar flame. Using a high-spatial-resolution flame zone measurement technique developed by the current research group, the flame zone of different NH3-containing mixtures was measured experimentally. These measurements were achieved by investigating spherically propagating flames using a chemiluminescence imaging diagnostic with a focus on NH2* profiles. The effect of the fuel mixture on the profile shape was examined by investigating two different mixtures: an oxy-ammonia mixture consisting of NH3 + oxygen-enriched oxidizer with varying O2 concentrations from 25% to 40%, and a blend of NH3-H2 with NH3 concentrations (XNH3) varied from 0.5 to 0.8. Additionally, the effect of the initial temperature was investigated by varying it from 293 to 373 K. In all investigated mixtures, the initial pressure was fixed at 1 atm and the equivalence ratio at 1.0. The study revealed that increasing the O2 concentration in the oxy-ammonia mixture produced thinner flames, while increasing XNH3 in the NH3-H2 blend produced slightly thicker flames. Varying the initial temperature had different effects: it thinned the flame in the oxy-ammonia mixture and NH3-H2 blend, but slightly thickened the flame in the H2-NH3-N2 blend. The predicted NH2* profile thicknesses from chemical kinetics agreed with measurements, except for the H2-NH3-N2 blend.

The effect of initial temperature on the mechanical strength of tricalcium phosphate/Chitosan/Silica aerogels nanocomposites using molecular dynamics simulation

BackgroundChitosan is an organic polymer derived from chitin, showcasing commendable biocompatibility and biodegradability, while tricalcium phosphate emerges as an active ceramic with proven biocompatibility and superior compatibility with bone tissue. This composite material, endowed with a unique amalgamation of attributes including biocompatibility, porosity, and mechanical strength, proves highly applicable in diverse fields such as tissue engineering, drug delivery systems, wound repair, and as scaffolds for cell proliferation in regenerative medicine. MethodsThe focal point of this study is an exploration of the nuanced interplay between the mechanical properties of silica aerogel/chitosan tricalcium phosphate nanocomposites with increasing initial temperature. Employing molecular dynamics (MD) simulation, the research aims to unveil the temperature-induced variations in the critical properties. Significant FindingsThe results reveal that the ultimate strength and Young's modulus values are determined to converge to 772.28 MPa and 62.291 GPa, at 297 K. As the initial temperature escalates from 300 to 350 K, the US decreases from 72.28 to 714.47 MPa. The decrease in US could be due to higher temperatures, the increased thermal energy can lead to greater atomic vibrations within the material, which can promote easier dislocation movement and result in reduced resistance to deformation. The results reveal that as temperature increases to 320 K, YM increases to 67.134, and with further increase in temperature, YM decreases to 62.865 GPa

Factors influencing demulsification of refinery oily sludge via ultrasonic treatment

Ultrasonic demulsification treatment is essential to dehydrate refinery sludge with complex composition, high water content, and demulsification difficulty. Herein, the influencing factors and the demulsification mechanism are studied in oily sludge treatment. The effects of initial temperature, ultrasonic amplitude, and time, as well as a diversity of additives on the ultrasonic dehydration rate of oily sludge demulsification, are investigated. The optimal demulsification conditions are confirmed (temperature: 20 °C, ultrasonic amplitude: 100 %, and ultrasonic time: 5 min), based on the effectiveness and economy of dehydration. The combined ultrasonication and pyrolysis of the solid residue of sludge shows a dehydration rate of 60.49 %, beneficial for the green transformation and utilization of subsequent demulsification products. Moreover, the mechanism of ultrasonic emulsification is proposed, as well. This work provides an important reference for the subsequent resource utilization of oily sludge in the industry.

Expression of Concern: Effect of Initial Temperature and Pressure on Thermal Behavior of Ethanol/Oxygen Fuel Mixture with Shock Wave by Molecular Dynamics Simulation

Expression of Concern: Effect of Initial Temperature and Pressure on Thermal Behavior of Ethanol/Oxygen Fuel Mixture with Shock Wave by Molecular Dynamics Simulation

Design and performance optimization of solar pyrolysis reactor for organic impurities in waste salt

The efficient removal of organic impurities in waste salt is significant for its recycling and environmental protection. In present paper, a solar pyrolysis reactor is proposed by integrating the parabolic trough concentrator (PTC) and solar reactor (SR). The results demonstrate that organic impurities react completely in 1290.7 s, and the thermal efficiency is up to 89.90 % at the initial temperature of 293.15 K and the reactor radius of 32 mm. However, the temperature difference (ΔT) in reactor is over 110 K. Based on this, the effects of initial temperature and reactor radius on pyrolysis results are explored. To improve the uniformity of temperature distribution and pyrolysis performance, a new pitchfork-shaped fin has been designed. Compared with no fins, the ΔT and reaction time are reduced by 54.99 % and 24.36 %, and the thermal efficiency is improved by 6.47 %. In comparison to traditional star-shaped fins, the ΔT is reduced by 13.1 %. Then, to further enhance the comprehensive performance of pitchfork-shaped fins, optimization on fin structure parameters is performed and validated. After optimization, the ΔT and reaction time are further reduced by 10.27 % and 2.3 %. The present work demonstrates that the PTC-SR is feasible for the efficient removal of organic impurities in waste salts, which is significant for the recycling and utilization of waste salt.

Future Global River Ice in CMIP6 Models under Climate Change

Abstract River ice changes due to climate change significantly impact river hydrology, economies, and societies. This study employed the CMIP6 data and a river ice model to predict global river ice changes in response to climate change. Results indicate significant declines in global river ice due to global warming. With each 1°C increase in surface air temperature (SAT) in the future, river ice extent of ice-affected rivers decrease by 2.11 percentage points, and ice duration shorten by 8.4 days. Under the SSP2-4.5 scenario, the long-term mean SAT is 1.2°C to 2.5°C higher than in the near-term. This leads to a 1.9 percentage points to 4.4 percentage points decrease in global river ice extent, a 6.8 to 15.1-day decrease in river ice duration, and ice-free rivers increasing by up to 4.02%. The SSP5-8.5 scenario predicts a warmer long-term mean SAT, leading to greater reductions in river ice. Geographically, river ice loss is most notable in North America, Europe, Siberia, and the Tibetan Plateau (TIB), particularly in peninsular, coastal, and mountainous regions due to the combined effects of initial temperatures and temperature increases. Overall, the E.Europe (EEU) shows the greatest loss of river ice on average. Monthly analyses show the most substantial decreases from October to June, indicating pronounced seasonal variability. This study provides valuable insights for addressing challenges related to river ice changes in high-latitude and high-elevation regions.

Effects of equivalent ratio and initial temperature on the explosion characteristics of ethanol, acetone, and ethyl acetate

In this paper, the effects of equivalence ratio (0.8–2.0) and temperature (30°C–120°C) on ethanol, acetone, and, ethyl acetate vapors explosion characteristics through experimental and numerical studies were investigated. The explosion overpressure and flame propagation velocity were recorded through the pressure transducer and high-speed camera. The results showed that the flame propagation velocity, peak explosion overpressure, and peak growth rate of explosion overpressure increased first and then decreased with the increase of equivalence ratio. The cracks on the flame surface enhanced with the increase of the equivalence ratio. As the initial temperature increased, peak explosion overpressure, the flame propagation velocity, and peak growth rate of explosion overpressure gradually increased. The sensitivity analysis of laminar burning velocity indicated that with the change of equivalence ratio and initial temperature, the shared elementary reactions that increased the reactivity were H + O2 <=> O + OH, HCO + M <=> H + CO + M, and CO + OH <=> CO2 + H, and the shared elementary reaction that reduced the reactivity was H + OH + M <=> H2O + M. The main factor affecting laminar burning velocity was the mole fraction of H and OH radicals.

Green adsorption of quinoline as basic N-compounds from liquid fuel using mesoporous and Fe-functionalized walnut shell-activated carbon

Removing nitrogenous compounds from liquid fuels is essential, and adsorption de-nitrogenation is a new process for this goal. This work has the purpose of investigating quinoline adsorption using Iron functionalized Activated carbon (IFAC) mesoporous nanocomposite. The mesoporous nanocomposite was synthesized in a one-step process by chemical activation of the walnut shell using Iron chloride as the activation and modification agent. The IFAC mesoporous nanocomposite was utilized to remove quinoline from isooctane as the liquid fuel via a discontinuous (batch) process by examining the effect of initial concentration, contact time, and temperature. The effect of contact time on the adsorption ability of IFAC for quinoline was well described by the pseudo-second-order model. The Langmuir model described the equilibrium manner of the process well, and the adsorbent could retain 344.82 mg/g of quinoline (37.37 mg N/g). The thermodynamic parameters show the endothermic (ΔH°= +30.070 kJ/mol) and spontaneity of the adsorption process. The regeneration experiments indicated that functionalized AC’s adsorption ability for quinoline adsorption decreased by 23% after five cycles. The obtained data indicate that the functionalization of activated carbon surface with iron particles leads to improving its adsorption ability toward N-containing compounds from liquid fuels.

Adsorption and estimation of As (III) from wastewater using cross linked Chitosan-STPP nanoparticles with voltammetric analysis computrace, isotherms, and kinetic study

Chitosan (CS) is a naturally occurring polycationic linear amino polysaccharide produced commonly through the deacetylation of chitin. This study describes the synthesis of Chitosan (CS) modified with sodium tripolyphosphate (STPP) using an efficient coated Cross-linked method. The study investigated the efficacy of chitosan-tripolyphosphate (CS-STPP) nanoparticles for the efficient adsorption of As (III) ions from a wastewater solution. The effect of initial Arsenic (III) ion concentration, solution pH, and temperature on adsorption efficiency was thoroughly investigated. The highest adsorption capacity of CS-STPP nano adsorbents for As (III) was found to be 39.8 mg/g and 39.6 mg/g, respectively, at pH 5.5, and a temperature of 30 °C. The FESEM, SEM, HRTEM, XRD, FTIR, DLS, and TGA results indicated that the adsorption process of As (III) was chemically dominating. As (III) Determine with the anodic linear sweep voltammetry 797 VA Computrace (Metrohm). The Langmuir parameters of 40.9 mg/g and 1000 L/mg were found for maximum adsorption capacity, which indicated monolayer adsorption on a homogeneous site, Freundlich isotherm is applicable for multilayer adsorption onto heterogeneous sites. The thermodynamic study showed that the adsorption of As (III) by CS-STPP was spontaneous, feasible, and exothermic at temperatures ranging from 30 °C to 50 °C. The kinetic model indicated that the adsorption processes persist well to the pseudo-second-order kinetics model. The reaction is suitable for a pseudo-second-order model, it indicates an inclination for chemisorption. Adsorption-desorption processes are determined efficiency of bio adsorbent by several physicochemical cycles. All results indicate that the prepared CS-STPP nanoparticles might be considered a cost-effective adsorbent for removing As (III) from wastewater.

Numerical simulation study of the effect of different factors on supercritical CO2 BLEVE

Abstract Global warming is harmful to the environment and CO2 is one of the major greenhouse gases. CCS-EOR technology can increase oil production and sequester CO2. During the storage and transportation of high-pressure CO2, BLEVE may occur. In this study, the dynamic pressure parameters in the supercritical CO2 BLEVE process were numerically simulated by using numerical simulation, and the effects of initial temperature and initial charge on the dynamic pressure parameters in the supercritical CO2 BLEVE process were mainly discussed. By thoroughly investigating the dynamic pressure of BLEVE of supercritical CO2, we can better understand and predict the conditions under which such accidents occur, and further improve the safety of industrial processes.

Biotransformation of Chlorpyrifos Shewanella oneidensis MR-1 in the Presence of Goethite: Experimental Optimization and Degradation Products.

In this study, the degradation system of Shewanella oneidensis MR-1 and goethite was constructed with chlorpyrifos as the target contaminant. The effects of initial pH, contaminant concentration, and temperature on the removal rate of chlorpyrifos during the degradation process were investigated. The experimental conditions were optimized by response surface methodology with a Box-Behnken design (BBD). The results show that the removal rate of chlorpyrifos is 75.71% at pH = 6.86, an initial concentration of 19.18 mg·L-1, and a temperature of 30.71 °C. LC-MS/MS analyses showed that the degradation products were C4H11O3PS, C7H7Cl3NO4P, C9H11Cl2NO3PS, C7H7Cl3NO3PS, C9H11Cl3NO4P, C4H11O2PS, and C5H2Cl3NO. Presumably, the degradation pathways involved are: enzymatic degradation, hydrolysis, dealkylation, desulfur hydrolysis, and dechlorination. The findings of this study demonstrate the efficacy of the goethite/S. oneidensis MR-1 complex system in the removal of chlorpyrifos from water. Consequently, this research contributes to the establishment of a theoretical framework for the microbial remediation of organophosphorus pesticides in aqueous environments.

Enhancing Cr (VI) Adsorption of Chestnut Shell Biochar through H3PO4 Activation and Nickel Doping.

A high-efficiency nickel-doped porous biochar (PCNi3) has been successfully synthesized from chestnut shell waste via a two-step chemical activation treatment with H3PO4. The influences of microstructure, surface morphology, elemental composition, surface functional groups, specific surface area, porosity, pore-size distribution, and chemical properties of the surface state on the removal of Cr (VI) from water were thoroughly investigated by using XRD, FESEM, FTIR, Raman, BET, and XPS testing methods, N2 adsorption, and XPS testing techniques respectively. The results indicate that the treatment of H3PO4 activation and nickel doping can effectively improve microstructure characteristics, thus promoting Cr (VI) adsorption capacity. The effects of initial solution pH, solution concentration, time, and temperature on remediation are revealed. The Cr (VI) uptake experiments imply that the adsorption curves of PCNi3 fit well with the Freundlich model, the pseudo-second-order kinetic model, and the Elovich model. The adsorption process of PCNi3 can be regarded as a spontaneous endothermic reaction limited by diffusion among particles and porosity. The adsorption mechanisms of PCNi3 are ion exchange, complexation, electrostatic adsorption, and coprecipitation with the assistance of surface active sites, porosity, Ni0 particles, and Ni7P3. With these advantages, PCNi3 reveals an extraordinary Cr (VI) removal capacity and a strong ability to reduce Cr (VI) to Cr (III).

Effect of temperature on the mechanical properties of aluminum polycrystal using molecular dynamics simulation

The initial temperature has a considerable effect on aluminum polycrystals' physical stability and mechanical performance, with the possibility to optimize their mechanical properties for practical applications. Thus, using a molecular dynamics technique, the effect of temperature on the mechanical properties of aluminum polycrystals is studied. Stress-strain curves, ultimate strength, and Young's modulus were all measured at temperatures of 300, 350, 400, and 450 K. The findings from MD simulations show that the initial temperature significantly affects the physical stability and mechanical performance of designed aluminum polycrystals. The aluminum polycrystal experiences a numerical increase in ultimate strength and Young's modulus from 6640 to 74.072 to 7.055 and 79.226 GPa, respectively, when subjected to the optimal initial conditions of 350 K. With further increasing temperature to 450 K, ultimate strength and Young's modulus decrease to 6.461 and 74.413 GPa, respectively. The observed decrease in ultimate strength and Young's modulus of the aluminum polycrystal as the temperature increased from the optimal condition of 350 K–450 K can be attributed to the weakening of interatomic attraction forces at higher temperatures. This reduction in interatomic bonding strength resulted in decreased material stiffness and resistance to deformation, leading to lower ultimate strength and Young's modulus values. This study's novelty lies in its comprehensive assessment of the initial temperature's effects on the mechanical performance of aluminum polycrystals, providing valuable insights for practical applications and advancing beyond previous efforts in the literature.

BIO-ADSORPTION OF HEAVY METAL ION FROM WATER USING ACTIVATED CARBON

The discharge of effluent polluted with heavy metals have become a growing concern for researchers around the world. This study evaluated the removal efficiency of commercial activated carbon and rice husk activated carbon as adsorbents for the removal of copper ion in water. A nominal size of 1 mm was obtained after sieving the Rice Husk, washed with distilled water, dried in an oven t at 80 ℃ for 12 hours, and pyrolyzed in a furnace at 550 ℃ for 30 minutes. The chars produced were later air-dried and then activated with lemon juice. The Rice Husk Activated Carbon (RHAC) and Commercial Activated Carbon (CAC) purchased from the market were both subjected to the following analyses: bulk density, X-ray Fluorescence (XRF), Brunauer–Emmett–Teller (BET), Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX) in order to characterise the adsorbents and to understand their suitability for the removal of copper ion in water. One of the properties of an adsorbent is large pores which is exhibited by the activated carbons as revealed by the SEM analysis. Likewise, the XRF and EDX analyses confirmed that the adsorbents had larger proportion of Silica (50.1 – 50.25%), Carbon (60.06 – 84.87 wt .%) and Oxygen (15.13 – 21.60 wt. %) which is a property of a good adsorbent. BET analysis showed that the surface areas of the rice husk activated carbon and the commercial activated carbon were 998.35 and 1208.25 m2/g, respectively. The bulk densities of the rice husk activated carbon and the commercial activated carbon were 0.3325 and 0.2812 g/cm3, respectively. The maximum removal efficiency using RHAC was observed at 60 ℃ and 120 minutes at 83.96 and 89.21 %, respectively while for CAC the maximum removal efficiency was observed at 60 ℃ at 84.61 % and 30 minutes at 83.3 %. Initial concentration of 20 mg/l was observed to have the highest removal efficiency for the two activated carbon specimens. The modelled effect of initial concentration, temperature and contact time on removal efficiency yielded R2 values of 1, 0.918; 1,1 and 1,1 respectively for the CAC and RHAC.

KMnO4 modified magnetic hydrochar for efficient adsorption of malachite green and methylene blue from the aquatic environment

This study exploited magnetic citrus peel hydrochar (MHC) modified by KMnO4 (MHC/Mn) for the removal of methylene blue (MB) and malachite green (MG). Effects of initial concentration, pH, dosage, temperature, and ion strength on MHC/Mn adsorption properties were investigated. The adsorption kinetics, isotherm, and mechanism were further explored. The results indicated that Fe3O4 was successfully embedded and MnO2 was coated on MHC after modification. The experiment data were well fitted to the pseudo-second-order kinetic model and Langmuir isotherm model. Thermodynamic parameters showed that the adsorption of MHC/Mn to MB is spontaneous and endothermic, and the adsorption of MG is spontaneous and exothermic. The mechanism of MB and MG interaction with MHC/Mn includes electrostatic interaction, hydrogen bond, surface complexation, and π-π interaction. The maximum adsorption capacity of MB and MG calculated were 175.63 mg/g and 1402.17 mg/g. After four adsorption–desorption cycles, the removal rate of MB and MG were 85.11 % and 69.29 %. MHC/Mn is an economical and environmentally favorable adsorbent for the removal of MB and MG in wastewater.

Study on the variation regularities of minimum explosion concentration of moist magnesium dust/derived hydrogen hybrids under multiple working conditions

Magnesium is widely used but often accompanied by frequent magnesium powder explosion accidents. If the variation regularity and mechanism of the minimum explosion concentration (cm) of magnesium powder under the multi-factor coupling effect can be understood, the occurrence of magnesium powder explosion accidents can be fundamentally avoided, and intrinsic safety can be achieved. In this paper, experiments were conducted using a self-made 20 L explosion device to explore the effects of particle size, initial temperature, and equilibrium relative humidity (ERH) coupling on the cm of magnesium powder. The study found that an increase in ERH of moist magnesium powder would lead to easier agglomeration of the dust, making it less prone to activation. Additionally, excessive moisture also absorbed more heat, reducing the ignition sensitivity of the dust cloud and resulting in a continuous increase in cm. However, increasing the initial temperature and decreasing the dust particle size both decreased the cm of moist magnesium powder, weakening the effect of ERH on cm. Furthermore, using the analysis methods of orthogonal experimental range and AHP model, it was determined that the influence weights of the factors coupling effects on the cm of magnesium powder, from highest to lowest weight, were: particle size > ERH > initial temperature.Furthermore, in order to deeper understand the mechanism of the action process that affect the cm of moist magnesium powder, additional experiments were conducted to further confirm that the addition of hydrogen derived from the erosion reaction of moist magnesium powder to the explosion system can reduce the cm of magnesium dust clouds. Moreover, a quantitative mathematical model for predicting the cm of magnesium powder/hydrogen two-phase system was also established.

The mechanism of granite breaking by electric pulse under high temperature and high pressure environment

AbstractHigh‐voltage electric pulse drilling technology has the advantages of high rock‐breaking efficiency, and low rock‐breaking energy consumption, which is one of the most promising rock‐breaking methods in geothermal drilling. However, there is insufficient understanding of the mechanism of high‐voltage electric pulse breaking of HDR under high‐temperature and high‐pressure environments (HTHP). In this paper, a numerical simulation model of electric breakdown under HTHP is constructed, and the whole process of high voltage electric pulse rock‐breaking and plasma channel generation is realized from the seven‐field coupling of circuit field, current field, magnetic field, breakdown field, heat transfer field, solid mechanics field and flow field. The temperature changes in the rock during the electric pulse rock‐breaking process were comprehensively analyzed, and the effects of different initial rock temperatures (200°C, 300°C, 400°C) and surrounding pressure conditions (30, 60, 90 MPa) on the high‐voltage electric pulse rock breaking law were considered. It is found that the thermal conductivity of the rock shows an increasing and then decreasing trend as the initial temperature of the rock increases, and that the thermal conductivity has a tendency to guide the development of plasma channels, and the radius of the plasma channels increases with the increase of the initial temperature of the rock. The heat transfer generated by high‐voltage electric pulse rock breaking is mainly in conduction, and the distribution shape of conduction heat is similar to the shape of the breakdown channel. The research in this paper can provide theoretical and technical guidance for developing electric pulse rock‐breaking technology.

Heat and mass transfer characteristics of non-equilibrium flash at start stage

Our experiments showed that a V shape pressure drop appeared at start stage of non-equilibrium flash. V shape pressure drop firstly denoted the generating of superheat degree, which should be the starting force driving the non-equilibrium flash. Then evaporated vapor made up the pressure drop. Finally, a dynamic equilibrium was reached between the flash rate and the outflow rate, and the pressure behaved decreasing gradually. However, few published references focus on this start stage of the non-equilibrium flash. In this paper, experiments of the flash were conducted to investigate the heat and mass characteristics during V shape start stage. Dimensionless flash conversion coefficient (FCC) was proposed to normalize the flash with different initial liquid mass at start stage. The effects of initial temperature and the valve opening degree on the heat and mass characteristics of flash during the V drop start stage were studied. The results showed that the pressure of the working fluid changed dramatically during the V drop start stage. The peak of instant liquid superheat was proportional to the opening degree of the valve, which controlled the outflow rate. The flash rate increased with increasing initial temperature and valve opening degree, which had an approximately linear relationship with the flash time. FCC increased with valve opening degree. It could be deduced that flash intensity or flash rate would be higher for an expander with larger outlet area or higher working temperature.

Nutritional and Molecular Studies of Alkaliphilic Tolerant Potential Amylase Producing Lactic Acid Bacteria Isolated from Indigenous Foods and Dumpsites

Alkaliphilic organisms are important in industries but most of these organisms are obtained from Bacillus species and the like that require special scrutiny before use in fermentation of food related products. Lactic acid bacteria are generally regarded as safe (GRAS) and are therefore readily applied in industrial fermentation with confidence. Due to high demand for the products of alkaliphilic organisms and industrial acceptability of lactic acid bacteria, there is a need to source for GRAS microorganisms that can withstand pH ranges. The aim of this study was to isolate alkaliphilic tolerant lactic acid bacteria from fermented cassava mash, `ogi` and dump site samples with a view to determining their nutritional requirement as well as molecular identity. Lactic acid bacteria were isolated from the samples using standard methods. The isolates were subsequently characterized morphologically, biochemically and molecularly. Effects of different carbon, nitrogen sources, initial temperature and pH as well as metal ions (Na+, Ca2+, Mg2+, Zn2+ and Cu2+) on the growth of the isolates were examined. Data obtained were analyzed using one-way analysis of variance (ANOVA). Results obtained indicate that extracted DNA sequence of A3, A7, A8 and A10 were related to those of Lactobacillus brevis FJ476121.1, Pediococcus acidilactici CP096031.1, Pediococcus pentasaceus AB362605.1 and Pediococcus acidilactici CP053421.1 respectively with the sequences within the GenBank. 1% fructose elicited growth for all the bacteria detected except Lactobacillus brevis and ammonium nitrate was most preferred by all the bacteria detected apart from Pediococcus pentasaceus strain. Lactobacillus brevis FJ476121.1 and Pediococcus acidilactici CP053421.1 were the most alkaliphilic tolerant bacteria detected with OD of 0.285±0.04 and 0.198±0.04 respectively. Different metal ions significantly influenced the growth of isolates in this study. The results in this study indicate potential applicability of the detected bacteria for industrial processes.

Studies on properties of laminar premixed oxygen-enriched NH3/H2/O2/N2 flames at elevated temperature and pressure

In this work, the effects of oxygen enrichment coefficient (Ω = 0.21 − 0.42) and initial temperature (Tu = 298 − 448 K) on the laminar burning properties of NH3/H2/O2/N2 flames are systematically investigated by using the spherical flame propagation method at equivalence ratios (Φ = 0.8 − 1.4) and initial pressure (Pu = 3 atm). LBV is analyzed by obtaining experimental data. In order to analyze flame instability, thermal diffusion and hydrodynamic instability are separated by linear stability theory. The thermal and chemical effects of oxygen enrichment on LBV and its effect on heat release rate are analyzed by numerical simulation. The results show that the laminar burning velocity (LBV) exhibits a positive correlation with both the oxygen enrichment coefficient and the initial temperature. The temperature index (α) exhibits a non-monotonic variation in response to the initial temperature of the NH3/H2/O2/N2 flame. Leeff is insensitive to temperature and positively correlated with the oxygen enrichment coefficient. The NH3/H2/O2/N2 flame is mainly affected by hydrodynamic instability when the oxygen enrichment coefficient is large. The peak NHRR scales positively with the oxygen enrichment coefficient. Oxygen enrichment helps to contribute to the overall net reaction rate.