Characterization of soybean biodiesel: Influence of alcohol type and molar ratio on speed of sound

Influence of SiO2 /Na2O molar ratio on mechanical properties and durability of metakaolin-fly ash blend alkali-activated sustainable mortar incorporating manufactured sand

Molecular dynamics (MD) simulation was conducted to research the effect of molar ratios for α/β-HMX, γ/β-HMX, and δ/β-HMX(octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) mixture systems on thermal stability, sensitivity, and mechanical properties of explosives, and the computing models were established by Materials Studio (MS). The binding energies, the maximum trigger bond length (LN-NO2), cohesive energy density as well as mechanical properties of the mixture systems and the pure β-HMX crystal were obtained and contrasted. The results demonstrate that the molar ratios have great influence on the binding capacity of molecules between α, γ, δ-HMX, and β-HMX in the mixture systems. The binding energies decrease with the increase of molecular molar ratio and have the maximum values at the 1:1M ratio. The maximum trigger bond length does not change apparently after mixing, while the cohesive energy density (CED) increases as the molar ratio increases but are all smaller than the pure β-HMX crystal, demonstrating that the sensitivity of the mixture systems increases. The mechanical properties decrease after mixture, which illustrates that the mechanical properties of the pure crystal are superior to the mixture systems.

Influence of molar ratio on Pd–Pt catalysts for methane combustion

The paper gives a review of more modern results of the 29Si n.m.r., chromatographic methods, molybdate and dye adsorption methods regarding the structure and characterization of technically important sodium water glass‐(sodium silicate‐solutions) with molar ratio SiO2/Na2O = 3–3,5. There are described the influence of molar ratio, SiO2 concentration, condensation degree, impurities and thermal treatment on the structure and properties respectively of sodium water glass (NaWG) solutions. The results show that the complicate structure of NaWG solutions and their influenceability by temperature, impurities, molar ratio and SiO2 concentration and furthermore the lack of suitable methods are reasons for the present insufficient characterization of NaWG solutions. It is shown that a more complete characterization especially regarding the thermal history of NaWG solutions is possible by combination of the molybdate method with the dye adsorption method. There is a hint of the existence of a thermal equilibrium state, which is influenced not only by the silicate anion distribution but the association equilibrium exused by concentration and state of distribution of impurities.

This study prepared the in situ formed iron hydroxide (in situ FeOxHy) by the interactions between Fe3+ and OH- at different molar ratios of 1:0, 1:1, 1:2 and 1:3. The influences of molar ratios and pH on the removal of phosphate were investigated and the surface of in situ FeOxHy before and after adsorption was analyzed. The phosphate removal rate with mass unit iron hydroxide is greater at the molar ratios of 1:3 between Fe3+ and OH-. The phosphate removal rate is maximum at the pH 6~7. The compatibility of iron hydroxide towards raw water pH value is better when the proportion of hydroxyl ion is greater. The disposal effect is good at the pH 4~9. The iron hydroxide formed at different molar ratios is not definitive shape and it can remove phosphate by the chemical action of adsorption and sedimentation.

Theoretical investigation into the influence of molar ratio on binding energy, mechanical property and detonation performance of 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclo octane (HMX)/1-methyl-4,5-dinitroimidazole (MDNI) cocrystal explosive

Aldol condensation between furans and levulinates shows a selective route for the polymers production. In this work, the influences of mole ratio between furans and levulinates as well as substrate species on the formation of polymers structure were investigated. The characterization of gel permeation chromatography and 13C nuclear magnetic resonance to the synthesized polymers suggested that the mole ratio between furans and levulinates, and substrate species exhibited a great effect on the structure of polymers. Higher mole ratios between furans and levulinates resulted in the aggravated polymerization. EMF-EL polymers showed larger molecular weight distribution compared with FFA-EL/LA polymers. This investigation further provides other key factors to the decision of polymer structure.

When mixing acetic anhydride and oleic acid, two consecutive reactions take place. The first one yields acetic‐oleic anhydride (AOA) and acetic acid. In the second one, oleic acid reacts with AOA to form oleic anhydride at 5% in a mixture when the initial molar ratio is 1:1. Therefore, at equilibrium, the global reaction yields a mixture of AOA, acetic anhydride, oleic acid, acetic acid and oleic anhydride. Based on a new HPLC protocol, all the species of the reaction medium could be separated and quantified. This permitted for the first time to study the kinetics and thermodynamics of the reaction. In the 30–70 °C range, reactions were of order 2 with partial orders of 1 for each reactant. Equilibrium constants were determined for both reactions. Enthalpy, entropy and activation energies were calculated for the main reaction. The influence of molar ratio on the composition at equilibrium was also investigated. The synthesis of AOA could thus be understood and new data were obtained for this singular molecule scarcely cited in the CAS database.

The synthesis of 2-actylfuran using from furan using acetic anhydride as an acylating agent via vapor phase catalysis has been reported. The influence of molar ratio, temperature and weight hour space velocity (WHSV) on yield of 2-actylfuran are investigated. The yield and selectivity of 2-actylfuran were observed to be 89.07% and 99.71%, respectively at temperature 573 K, WHSV 0.3 h−1 and molar ratio 1: 4 on Co2+/Ni2+/Cr+2 ionic distribution in the spinel lattice effects the acidic-basic properties. It was also observed that catalytic activity of ferrites was influenced by the acidity of catalyst.

Nickel mesoporous materials with different Si/Ni ratios = 85, 55, 15 have been synthesized by intercalating kanemite using cetyltrimethylammonium bromide (CTMABr) as the intercalating agent and nickel nitrate as the nickel source. The resulting samples were characterized by means of inductively coupled plasma (ICP) technique, XRD, BET and a temperature-programmed-desorption (TPD) of pyridine. The effect of the Si/Ni molar ratio on the textural properties of Ni-FSM-16 was investigated. The results reveal that the Ni-FSM-16 samples were successfully synthesized. The catalytic performance was examined in the vapor phase tert-butylation of anisole with tert-butanol at the temperatures between 423 and 523 K under atmospheric pressure. The results indicate that the sample Ni-FSM-16 (15) was more active than other catalysts of this series. The major products of alkylation were 4-tert-butyl anisole (4-TBA), 2-tert-butyl anisole (2-TBA), and 2,4 di-tert-butyl-anisole (2,4-DTBA). The maximum conversion of anisole is observed at 473 K and it decreased further with increasing temperature. The influence of molar ratio, temperature, weight hourly space velocity (WHSV) and time on stream on the selectivity of products was investigated and the results are discussed.

Zr-incorporated Folded Sheet Mesoporous material (FSM-16) with different Si/Zr ratios = 90, 60, 10 have been synthesized by intercalating kanemite using cetyltrimethylammonium bromide (CTMABr) as the intercalating agent and zirconium sulphate precursors as the zirconium source. The resulting samples were characterized by means of inductively coupled plasma (ICP) technique, XRD, BET, TEM, FT-IR, UV–Vis and a temperature–programmed–desorption (TPD) of pyridine. The effect of the Si/Zr molar ratio on the textural properties of Zr-FSM-16 was investigated. The results reveal that the Zr-FSM-16 was successfully synthesized. The catalytic performance was examined in the vapor phase tert-butylation of anisole with tert-butanol at the temperatures between 423 and 523 K under atmospheric pressure. The results indicate that Zr-FSM-16 (10) was found to be more active than its relatives.The major products are found to be 4-tert-butyl anisole (4-TBA), 2-tert-butyl anisole (2-TBA) and 2,4 di-tert-butyl-anisole (2,4-DTBA). Maximum conversion of anisole is observed at 473 K and decreased after that with increasing temperature. The influence of molar ratio, influence of temperature, weight hourly space velocity (WHSV) and time on stream on the selectivity of products was investigated and the results are discussed.

Modified (Ba,Sr)(Sn,Ti)O3 via hydrothermal synthesis for electrocaloric application

The experiment on phosphorus recovery in PTMEG wastewater by crystallization was studied. The influences of molar ratio, precipitation time, stirring speed on the amount of crystals and structure characterization have been studied. The results indicated that under molar ratio 1.5:1, stirring speed about 200r/min and precipitation time 2h, PO43- removal ratio above 85%, the morphology of obtained crystals was related to the stirring speed and the X-ray diffraction pattern showed that the crystals had a high purity.

Olivine LiFePO 4 , as a cathode material for lithium ion batteries, was prepared by a novel optimized hydrothermal method; afterwards, the product mixed with glucose was two‐step (350°C and 700°C) calcinated under high‐purity N 2 atmosphere to obtain the LiFePO 4 /C composite. The study on the hydrothermal preparation method, which focused on the influences of molar ratios, initial pH value, reaction temperature, and duration, was made to promote the resultant performances and to investigate the relations between the performances and the reaction conditions. The resultant samples were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical tests, which include charge‐discharge, electrochemical impedance spectroscopy, and cyclic voltammetry. The result shows that the optimal hydrothermal condition is to set the Li:Fe:P molar ratio at 3:1:1 and the reaction temperature at 180°C for 5 h duration with an initial pH value of 7. The optimized sample, with an average particle size of 100 to 300 nm and a discharge capacity of 118.2 mAh·g −1 at 0.1C, exhibits a stable and narrow‐gapped charge‐discharge platform and small capacity losses after cycles.

Characterization and therapeutic efficacy evaluation of glimepiride and L-arginine co-amorphous formulation prepared by supercritical antisolvent process: Influence of molar ratio and preparation methods.