This work evaluates the influence of binder:aggregate ratio on the mineralogical and mechanical properties of air lime–metakaolin mortars.
Mineralogical analysis showed that binder:aggregate ratio ...affects the extent of carbonation and pozzolanic reactions with curing. The pozzolanic reaction occurs mostly at lower curing times (28days), while, at higher curing ages, carbonation reaction is mostly dominant. The exceptions are mortars with 1:1 (air:lime) volumetric ratio with 30% and 50% MK in which the pozzolanic reaction is still dominant.
The reduction in the mechanical resistance of some compositions observed from 28 to 90days is related to the calcium aluminate hydrate instability in the presence of free lime. This instability is expected to disappear after the total consumption of free lime, either by pozzolanic or carbonation reaction.
The mechanical and thermal characteristics composites reinforced with E-glass fibre were examined in the current study. The mechanical stirring technique followed by the hand layup method was used to ...make composites loaded with different weight percentages of nanographene and a layer of e-glass. Nano-composite is made up of three different compositions by adjusting the weight percentages of each nanomaterial by 1%, 2%, and 3%. The generated nanocomposites' mechanical characteristics, including flexural strength, tensile strength, TGA, DTA, DSC, and hardness, were investigated and compared on a varying of nanofillers. The results showed that, when compared to neatly stacked composites, the introduction of nanographene (NG) composites can be a successful strategy in terms of mechanical qualities. Results are presented after examination of the experimental values of 1, 2, and 3 wt% of nanographene in the E-glass fabric reinforced composite. Additionally, it was found that adding nanomaterials the mechanical and thermal properties of nanographene to decrease after reaching their optimum weight percentage.
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•2-Methoxycinnamylidenepyruvate as a novel ligand for the synthesis of complexes.•Complexes with well-defined structural arrangements.•Thermal decomposition dependent on the nature of ...the metal ion.•Study by TG/FT-IR and TG/MS of the gaseous products released.•Potential technological application.
Compounds of 2-methoxycinnamylidenepyruvate with trivalent lanthanide ions (Tb, Ho, Er, Tm, Yb and Lu) were obtained in solid state and studied mainly in terms of their thermal and spectroscopic properties. The analyses of the characterization were performed by thermogravimetric system coupled to a mass and infrared spectrometer (TG–DTA/MS and TG–DTA/FT-IR), X-ray powder diffractometry, differential scanning calorimetry (DSC), infrared (FT-IR), preliminary study of fluorescence as well as classical technique of titration with EDTA. From these results, it was possible to establish the stoichiometry, thermal behavior, hydration water content, and the gaseous products released in the thermal decomposition steps, and suggest the type of metal-ligand coordination.
•The thermal characteristics of DNZTO were studied by TG–DTA and ARC.•TG–DTA tests at six different heating rates below 10°Cmin−1 were employed.•The thermal decomposition products of DNZTO were ...studied by FTIR–TGA–MS.
Thermogravimetric–differential thermal analysis (TG–DTA) and accelerating rate calorimetry (ARC) were performed to understand thermal characteristics and kinetics of energetic N,N′-dinitro-4,4′-azo-Bis(1,2,4-triazolone) (DNZTO). A single sharp and narrow exothermic decomposition occurred at 143.3, 150.3, 156.4, 157.4, 159.8 and 160.3°C at different heating rates (0.5, 1, 2, 3, 4, and 5°Cmin−1) suggesting that DNZTO composition was vulnerable to thermal hazard. The FTIR–TGA–MS results revealed that the decomposition product was made up of H2O, NO2, NO, CO2, CO, HCN, and N2O. ARC studies depicted onset temperature at 116.6°C with temperature step of 5°C and phi factor of 41.46, and a sharp rise in exothermic reaction at 127.69°C within the time span of 49.04min with the maximum heat release rate of 0.47°Cmin−1. The exothermic activity resulted in adiabatic pressure rise of the sample up to 300kPa by the sample pyrolysis into gas. In addition, the kinetic parameters of DNZTO were estimated for the thermal process by TG–DTA and ARC.
A bactéria Salmonella spp. é um dos principais agentes etiológicos de DTA (doenças transmitidas por alimentos) no Brasil e no mundo, nas quais os ovos e os produtos à base de ovos estão envolvidos em ...diversos surtos. A contaminação dos ovos pode ocorrer em diversas etapas ao longo da cadeia produtiva, desde a obtenção dos pintinhos até o processamento. Portanto, as medidas para minimizar a contaminação destes produtos de origem animal, com a prevenção e o controle da presença de salmonella em ovos é de suma importância para saúde única.
•The structure and the thermal properties of hydroxylpropyl-β-cyclodextrins were evaluated.•The DS value increased according to the quantity of propylene oxide and the substitution pattern depends on ...the alkali conditions.•The thermal decomposition temperature of HPCDs was enhanced linearly as the molecular DS increased.
The structure and thermal properties of hydroxylpropyl-β-cyclodextrins (HPCDs) with different degrees of substitution (DS) and different substitution sites were evaluated via GC–MS, FTIR, and TG–DTA combined thermoanalytical techniques. The results of GC–MS provided the DS and substitution pattern of the HPCD samples. The IR spectra of HPCDs showed all characteristic peaks corresponding to cyclodextrin. Furthermore, the characteristic peaks for methyl in the hydroxypropyl group at 2960 and 1375cm−1 were observed. The thermal decomposition temperature of HPCDs was about 300°C to 400°C and enhanced linearly as the molecular DS increased. The rate of DS rise of HPCDs prepared at a strong alkaline condition was higher than that prepared in a weak alkaline solution.
A novel bioactive Cu (II), Co (II) and Ni (II) complexes of the azo dye ligand (L) derived from sulfamethoxazole were synthesized. The structures of the newly synthesized compounds were characterized ...by elemental analysis, molar conductance, magnetic susceptibility, FTIR, UV–visible, 1H NMR, mass, thermal and powder XRD spectral techniques. Molar conductivity measurements in DMSO solution confirmed the non-electrolytic nature of the complexes. All the synthesized metal complexes were found to be monomeric and showed square planar geometry except the Co (II) complex which has six coordinate, octahedral environment. The metal complexes have exhibited potential growth inhibitory effect against tested bacterial strains as compared to the free ligand. The ligand and complexes have also shown significant antioxidant and Calf Thymus DNA cleavage activities. Further, the in silico molecular docking studies were performed to predict the possible binding sites of the ligand (L) and its metal complexes with target receptor Glu-6P.
•Synthesis and characterization of novel metal complexes derived from sulfamethoxazole based azo dye.•The analytical data confirmed the metal to ligand ratio is 1:2 stoichiometry of the type M (L)2.•All the synthesized compounds showed significant antimicrobial activity.•The ligand and its metal chelates have promising cleavage ability against CT DNA.
Homogenous and transparent 50ZnO:40B2O3:10WO3:xEu3+, x = 0, 0.1, 0.5, 1, 2, 5 and 10 mol% glasses were obtained by melt quenching method. Their crystallization behavior was studied by Differential ...Thermal Analysis (DTA) and X-ray Diffraction Analysis (XRD) measurements. It was established the formation of ZnWO4 as a single crystalline phase after thermal treatment of the glasses containing from 0 to 2 mol% Eu2O3. Several crystalline phases: ZnWO4, ZnB4O7 and H3BO3 were detected in the XRD patterns of glass crystalline samples containing 5 and 10 mol% Eu2O3. The PL emission spectra at room temperature of the prepared materials were measured.
The application of nanomaterials for water treatment has gained impetus in recent years. Nano-adsorbents offer significant decontamination potential due to their unique characteristics. Present study ...deals with synthesis and application of alumina nanoparticles for removal of an anionic dye, Orange G (OG) from aqueous solutions. The properties of synthesized nanoparticles were investigated by FTIR, TG/DTA, XRD, TEM, SEM, EDX and N2 adsorption-desorption techniques. The effect of various important parameters on dye removal was examined and adsorption was found to be highly pH dependent and maximum removal of 98.4% was observed at pH 2.5. The presence of interfering anions such as SO42−, PO43−, and C2O42− was found to be limiting factor of the adsorption process. The kinetic results demonstrated that the sorption process was described by pseudo-second-order model. Mechanism of adsorption process was also interpreted with the help of diffusion models and the results exhibited that external diffusion governed the overall sorption process. The Langmuir model yielded a good fit for the experimental data with high adsorption capacity (93.3mg/g at 303K). The evaluated thermodynamic parameters ΔG°, ΔH° and ΔS°, proposed that adsorption of OG was spontaneous, feasible, and exothermic under investigated conditions. Desorption experiments confirmed that the exhausted adsorbent can be successfully regenerated and can be effectively reused up to four successive cycles with almost the same sorption capacity resulting in reducing cost of treatment. The adsorption performance of alumina nanoparticles was also tested by using real wastewater and results indicated that nano alumina is proficient for the treatment of multi-solute system also.
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