Explore the vast range of titles available.

Collagenous biomaterials that are clinically applied in dentistry have dermis-type and membrane-type, both of which are materials for promoting bone and soft tissue formation. The properties of materials supplied with different types could affect their biodegradation periods. The purpose of this study was to characterize five of these products by four different methods: scanning electron microscopy (SEM) observation, thermogravimetry-differential thermal analysis (TG-DTA), 0.01 wt% collagenase dissolution test, and subcutaneous implantation test in vivo. SEM micrographs revealed that both dermis and membranous materials were fibrous and porous. The membranous materials had higher specific derivative thermal gravimetry (DTG) peak temperatures in TG-DTA at around 320 °C, longer collagenase dissolution time ranging from about 300 to 500 min, and more longevity in mice exceeding 9 weeks than the dermis materials. There existed a correlation between the peak temperature in TG-DTA and the collagenase dissolution time. It was considered that higher cross-link degree among collagen fibrils of the membrane-type collagenous materials might account for these phenomena. The experimental protocol and numerical results obtained could be helpful for selection and future development of fibrous collagenous biomaterials in clinical use.

In this paper, the effect on thermal behavior and compounds mineralogy of replacing different percentages of fly ash with compact particles was studied. A total of 30% of fly ash was replaced with mass powder glass (PG), 70% with mass natural aggregates (S), and 85% with mass PG and S. According to this study, the obtained fly ash based geopolymer exhibits a 20% mass loss in the 25–300 °C temperature range due to the free or physically bound water removal. However, the mass loss is closely related to the particle percentage. Multiple endothermic peaks exhibit the dihydroxylation of β-FeOOH (goethite) at close to 320 °C, the Ca(OH)2 (Portlandite) transformation to CaCO3 (calcite) occurs at close to 490 °C, and Al(OH)3 decomposition occurs at close to 570 °C. Moreover, above 600 °C, the curves show only very small peaks which may correspond to Ti or Mg hydroxides decomposition. Also, the X-ray diffraction (XRD) pattern confirms the presence of sodalite after fly ash alkaline activation, whose content highly depends on the compact particles percentage. These results highlight the thermal stability of geopolymers in the 25–1000 °C temperature range through the use of thermogravimetric analysis, differential thermal analysis, and XRD.

Biomass is one of the renewable energy and material sources. Agricultural biomass wastes are in top list in terms of quantity and uniformity. The stalks, leafs, and peels of them have taken considerable attention for various purposes. The biomass and wastes in recycling of matter and recuperation of chemicals with thermochemical conversion techniques are an efficient way in environmental perspective. The alliaceous plant reaches huge amount and its peels take attention in terms of difficulty of recycling with potential valuable compounds like its pulp. Here the pyrolysis of this garlic peel wastes was accomplished to obtain various valuable solid and liquid products that were analyzed with miscellaneous methods (thermogravimetric analysis/differential thermal analysis, gas chromatography/mass spectrometry, and scanning electron microscope). Three basic zones were appeared in thermal analysis for pyrolysis process. The valorization of these wastes to obtain precious chemicals and combustible compounds equivalent to petroleum products was illustrated by this way. Also carbonaceous compounds have been sequestered in solid and liquid forms by this way. The main fuel additives, methanol was obtained in remarkable amount (22.5%) from the liquid products. Also, porous material was produced from the solid products.

Coal ash-based geopolymers with mine tailings addition activated with phosphate acid were synthesized for the first time at room temperature. In addition, three types of aluminosilicate sources were used as single raw materials or in a 1/1 wt. ratio to obtain five types of geopolymers activated with H3PO4. The thermal behaviour of the obtained geopolymers was studied between room temperature and 600 °C by Thermogravimetry-Differential Thermal Analysis (TG-DTA) and the phase composition after 28 days of curing at room temperature was analysed by X-ray diffraction (XRD). During heating, the acid-activated geopolymers exhibited similar behaviour to alkali-activated geopolymers. All of the samples showed endothermic peaks up to 300 °C due to water evaporation, while the samples with mine tailings showed two significant exothermic peaks above 400 °C due to oxidation reactions. The phase analysis confirmed the dissolution of the aluminosilicate sources in the presence of H3PO4 by significant changes in the XRD patterns of the raw materials and by the broadening of the peaks because of typically amorphous silicophosphate (Si–P), aluminophosphate (Al–P) or silico-alumino-phosphate (Si–Al–P) formation. The phases resulted from geopolymerisation are berlinite (AlPO4), brushite (CaHPO4∙2H2O), anhydrite (CaSO4) or ettringite as AFt and AFm phases.

The Al-rich part of the Fe-Al phase diagram between 50 and 80 at.% Al including the complex intermetallic phases Fe 5 Al 8 (ε), FeAl 2 , Fe 2 Al 5 , and Fe 4 Al 13 was re-investigated in detail. A series of 19 alloys was produced and heat-treated at temperatures in the range from 600 to 1100 °C for up to 5000 h. The obtained data were further complemented by results from a number of diffusion couples, which helped to determine the homogeneity ranges of the phases FeAl 2 , Fe 2 Al 5 , and Fe 4 Al 13 . All microstructures were inspected by scanning electron microscopy (SEM), and chemical compositions of the equilibrium phases as well as of the alloys were obtained by electron probe microanalysis (EPMA). Crystal structures and the variation of the lattice parameters were studied by x-ray diffraction (XRD) and differential thermal analysis (DTA) was applied to measure all types of transition temperatures. From these results, a revised version of the Al-rich part of the phase diagram was constructed.

ABSTRACT Purpose The advent of cocrystals has demonstrated a growing need for efficient and comprehensive coformer screening in search of better development forms, including salt forms. Here, we investigated a coformer screening system for salts and cocrystals based on binary phase diagrams using thermal analysis and examined the effectiveness of the method. Methods Indomethacin and tenoxicam were used as models of active pharmaceutical ingredients (APIs). Physical mixtures of an API and 42 kinds of coformers were analyzed using Differential Scanning Calorimetry (DSC) and X-ray DSC. We also conducted coformer screening using a conventional slurry method and compared these results with those from the thermal analysis method and previous studies. Results Compared with the slurry method, the thermal analysis method was a high-performance screening system, particularly for APIs with low solubility and/or propensity to form solvates. However, this method faced hurdles for screening coformers combined with an API in the presence of kinetic hindrance for salt or cocrystal formation during heating or if there is degradation near the metastable eutectic temperature. Conclusions The thermal analysis and slurry methods are considered complementary to each other for coformer screening. Feasibility of the thermal analysis method in drug discovery practice is ensured given its small scale and high throughput.

Cellulose powder and cellulose pellets obtained by pressing the microcrystalline powder were studied using differential scanning calorimetry (DSC), differential thermal analysis (DTA), and thermal gravimetry (TG). The TG method enabled the assessment of water content in the investigated samples. The glass phase transition in cellulose was studied using the DSC method, both in heating and cooling runs, in a wide temperature range from -100 to 180 °C. It is shown that the DSC cooling runs are more suitable for the glass phase transition visualisation than the heating runs. The discrepancy between glass phase transition temperature T g found using DSC and predictions by Kaelbe's approach are observed for “dry” (7 and 5.3% water content) cellulose. This could be explained by strong interactions between cellulose chains appearing when the water concentration decreases. The T g measurements vs. moisture content may be used for cellulose crystallinity index determination.

Thermal measurements of high-pressure transitions in metals can provide thermodynamic insight into the properties of the high-pressure high-temperature phases and their transitions. However, these measurements have been essentially limited to a few large high-pressure facilities. An innovative pressure cell, designed for sensitive differential thermal analysis (DTA) measurements at elevated temperatures (300–1000 K) and high pressures (0–6 GPa) implemented in a ‘Paris–Edinburgh’ tabletop press, is presented. Differential measurements enable capture of small thermal signals, e.g., typical solid–solid transitions. The new cell’s capability is demonstrated via thermal measurements of transitions across the phase diagrams of indium, tin, and antimony. The melting transitions of these metals were identified based on the DTA measurements, together with the subtler transitions in the solid phases. The enthalpy of transition between solid phases was found to be significantly smaller than upon melting. Hence, the sensitivity of the experimental design is demonstrated. By consolidating the transitions obtained from the DTA curves during isobaric measurements, the high-pressure phase diagrams of the elements were reconstructed. For comparison, the high-pressure phase diagrams of In and Sb were determined by electrical resistance measurements. The phase diagrams obtained by high-pressure DTA measurements were found to agree very well with these and with previous experimental determinations using thermal and other methods.

Two methods were used to investigate the Y 2 O 3 -Ta 2 O 5 system: the equilibration method, which covered temperatures from 1573 to 1973 K, and the DTA method, which reached up to 2473 K. Phase identification was carried out using x-ray diffraction and scanning electron microscopy with energy-dispersive x-ray spectroscopy (SEM/EDX). The temperature of the eutectic reaction, L → YTa 3 O 9  (P) + Ta 2 O 5 , was determined to be 2019 K, with the corresponding eutectic composition being 78 mol.% Ta 2 O 5 . The study presents evidence that contradicts the existence of the eutectic reaction L → YTaO 4  (T) + YTa 3 O 9  (P). Instead, it identifies a peritectic reaction L + YTaO 4  (T) → YTa 3 O 9  (P), which was observed at a temperature of around 2075 K. Additionally, the heat capacity of the YTa 3 O 9 (P) phase was measured using differential scanning calorimetry (DSC) over the temperature range from 240 to 1300 K. The results of this experimental investigation will lead to the development of a thermodynamic database for the Y 2 O 3 -Ta 2 O 5 system.

Single crystals of tetramethylammonium cadmium chloride were grown by slow evaporation technique. The single-crystal X-ray diffraction revealed that the crystal belongs to hexagonal crystal system with P6 3 /m space group. The crystalline nature of the grown crystal was measured by power X-ray diffraction. The presence of functional groups was identified using Fourier transform infrared and Fourier transform Raman studies. The optical absorption studies showed that the grown crystal transmit most of the incident radiation in the range of 200–800 nm. The diamagnetic property of the grown crystal has been analyzed by vibrating sample magnetometer. The mechanical stability of crystal is analyzed by Vickers microhardness study. Dielectric measurements were taken to analyze the dielectric constant and dielectric loss at different frequencies and temperatures. The thermal stability of grown crystals was confirmed by thermogravimetry/differential thermal analysis. Thermal stability of the compound was entered up to 208 °C.