Thermochimica Acta最新文献

{"title":"Probing precipitation in aluminium alloys during linear cooling via in-situ differential scanning calorimetry and electrical resistivity measurement","authors":"Zi Yang ,&nbsp;Sina Mallow ,&nbsp;John Banhart ,&nbsp;Olaf Kessler","doi":"10.1016/j.tca.2024.179815","DOIUrl":"10.1016/j.tca.2024.179815","url":null,"abstract":"<div><p>Investigating precipitation processes in aluminium alloys during cooling from the solutionising temperature is important because the level of solute supersaturation and the presence of pre-precipitated solutes determine the response to the subsequent age hardening step. Differential scanning calorimetry has been developed to a suitable method to follow precipitation over a wide range of cooling rates. We develop a device that allows us to measure electrical resistivity <em>in-situ</em> during the quenching of alloy samples from the solutionising temperature. A procedure is formulated that allows us to separate the signal related to precipitation from the large background caused by the temperature dependence of electrical resistivity. Application to an aluminium alloy 6014 reveals a two-stage precipitation reaction during cooling at rates between 1 and 20 K min^-1, the first related to precipitation of the stable β phase, the second due to the formation of various metastable phases. Comparison between resistivity and DSC signals measured at the same cooling rate shows very close correspondence between the two. Thus, in the future, both methods could be used in a complementary way.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179815"},"PeriodicalIF":3.1,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0040603124001540/pdfft?md5=421e33d75fc8c81140d70cf8ad78db4d&pid=1-s2.0-S0040603124001540-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141689309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Unified Extrapolation thermodynamic model for multicomponent solutions based on binary data","authors":"Tianhua Ju ,&nbsp;Zhenlin Huang ,&nbsp;Xueyong Ding ,&nbsp;Xinlin Yan ,&nbsp;Changzong Liao","doi":"10.1016/j.tca.2024.179824","DOIUrl":"10.1016/j.tca.2024.179824","url":null,"abstract":"<div><p>Predicting the thermodynamic properties of multicomponent solution based on binary data is highly desirable. However, traditional methods face many challenges in practical applications due to the unclear mechanisms for obtaining the molar composition of sub-binary terms. In this article, a new extrapolation model is suggested, which derived from the assumption of the Kohler model. It determines the molar composition points of each sub-binary system through a clear mechanism by introducing the contribution coefficient, defined by the property differences between two components. Moreover, the new model can mathematically obtain all potential molar composition points of sub-binary systems. Additionally, a simple and effective method for calculating the property difference between two components is recommended. The performance of this new extrapolation model is demonstrated in several multicomponent alloy systems with different properties.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"740 ","pages":"Article 179824"},"PeriodicalIF":3.1,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141689554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revisiting biomass compositions determination using thermogravimetric analysis and independent parallel reaction model","authors":"Nanta Sophonrat,&nbsp;Margaret Wooldridge","doi":"10.1016/j.tca.2024.179814","DOIUrl":"10.1016/j.tca.2024.179814","url":null,"abstract":"<div><p>The determination of biomass composition via thermogravimetric analysis (TGA) has been a subject of considerable interest for many years. The current work proposes a revised workflow for determining the amounts of cellulose, hemicellulose, and lignin in biomass by combining TGA under an inert atmosphere with analyses of extractives and ash. An independent parallel reaction (IPR) model used for the deconvolution of the derivative thermogravimetry data was improved by constraining model parameters, i.e., thermal decomposition kinetic parameters and char fractions of cellulose, hemicellulose, and lignin, with values compiled from the literature using statistical analysis. The workflow is developed and demonstrated using cellulose and starch mixtures and then applied to biomass with varying levels of ash, including pine, birch, and oak wood, switchgrass, and pine bark. Using extractive-free biomass in the new TGA-IPR workflow improved the composition results compared with untreated biomass. The compositions determined by this method agreed well with values reported in the literature (within approx. 8 wt%) for the tested samples. The results demonstrate improved biomass composition accuracy using an accessible and rapid TGA-based approach.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179814"},"PeriodicalIF":3.1,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141623764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and kinetic study of PET pyrolysis under fast and slow heating rates using a visualized Macro TGA","authors":"Sanjun Wu,&nbsp;Jiaye Li,&nbsp;Qi Sun,&nbsp;Zhenshan Li","doi":"10.1016/j.tca.2024.179812","DOIUrl":"10.1016/j.tca.2024.179812","url":null,"abstract":"<div><p>A visualized macro thermogravimetric analyzer was utilized to gather data on sample weight, temperature, and image signals of centimeter-scale PET. The PET was subjected to both fast (above 300 K/min) and slow (below 25 K/min) heating rates. The experimental findings revealed that weight loss mainly occurred at different temperature ranges under fast (above 610 °C) and slow (400–520 °C) heating rates. The isoconversional method (ICM) and the distributed activation energy model (DAEM), both assuming single-step reactions, were employed separately to predict the conversion and rate of PET pyrolysis. However, the prediction error was considerable. To address this issue, a discrete distributed activation energy model (DDAEM) was developed, incorporating both single-step and double-step parallel reactions. The DDAEM yielded a prediction error within 10 %, which is better than ICM and DDAEM. Furthermore, all three models (ICM, DAEM, and DDAEM) indicated significant discrepancies in activation energies between fast and slow heating rates.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179812"},"PeriodicalIF":3.1,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141623767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pyrolysis of folic acid: Identification of gaseous/volatile products and structural evolution of N-doped graphitic carbon","authors":"Vagner R. Magri ,&nbsp;Caroline S. de Matos ,&nbsp;Michele A. Rocha ,&nbsp;Christine Taviot-Gueho ,&nbsp;Vera R.L. Constantino","doi":"10.1016/j.tca.2024.179813","DOIUrl":"10.1016/j.tca.2024.179813","url":null,"abstract":"<div><p>Folic acid (FA) is a low-cost and suitable source for producing different N-doped carbon materials by pyrolysis. However, the pyrolytic steps of FA are not entirely understood, particularly above 350 °C, which hampers the intelligent design of tailor-made carbon materials by a one-pot route. In this work, the pyrolytic decomposition steps of FA were investigated by simultaneous thermogravimetric analysis (TGA) and differential scanning calorimetry (TGA-DSC). The released gaseous/volatile products were probed by coupling TGA to infrared spectroscopy and mass spectrometry (TGA-FTIR-MS). Considering the thermal analysis data, FA was pyrolysed in a furnace at 350, 430, 570, 800, and 1000 °C, and the products were analysed by X-ray diffractometry (XRD), vibrational spectroscopy, and X-ray photoelectron spectroscopy. <em>In situ</em> high-temperature X-ray diffractometry (HT-XRD) experiments were also conducted under the nitrogen atmosphere. According to the data set, insights about FA decomposition steps could be proposed, including gaseous/volatile products released during the process and the structural evolution of N-doped graphitic carbon. The formation of carbonaceous material initiated between 200 and 350 °C through polymerisation/condensation reactions, and this step was marked by the release of 2-pyrrolidone and aniline. The graphitisation was enhanced above 350 °C, increasing graphitic nitrogen while the amide groups vanished. The process was accompanied by deoxygenation (i.e., CO and CO₂ release) and denitrogenation (e.g., NH₃, HNCO, and HCN) reactions. In the 570–800 °C range, the N-enrichment of carbon material (N-pyridine, N-pyrrole/Csp²-N in 5,7-membered rings, and nitrile) could occur by the reaction of released NH₃ over the char surface. Graphitic-like structures containing mainly N-graphite and N-pyridine were obtained above 800 °C. The original data about the thermal decomposition steps of FA allow for optimising the synthesis of N-doped carbon materials suitable for applications in adsorption, sensing, catalysis, and energy storage.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179813"},"PeriodicalIF":3.1,"publicationDate":"2024-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141694548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the thermal decomposition kinetics of ammonium carbamate for low-grade heat utilization","authors":"Suzhou Dai ,&nbsp;Yonggao Yin ,&nbsp;Yikai Wang ,&nbsp;Bowen Cao ,&nbsp;Maurizio Peruzzini ,&nbsp;Francesco Barzagli","doi":"10.1016/j.tca.2024.179809","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179809","url":null,"abstract":"<div><p>The thermochemical reaction of ammonium carbamate (AC) holds significant potential for low-grade heat utilization. However, the insufficient understanding of reaction kinetics limits its further applications. Therefore, a detailed study on the kinetic mechanism of AC decomposition was conducted using both the model-free and model-fitting thermal analysis methods with kinetic data from multiple heating program experiments. The results obtained from various methods are consistent, supporting the concept that AC decomposition is a single-step controlled multi-step reaction. The activation energy <em>E</em>, preexponential factor <em>A</em>, and most probable reaction model were determined to be 56.38 kJ∙mol⁻¹, 2.75 × 10⁶ s⁻¹, <em>f</em>(<em>α</em>)=(1-<em>α</em>)^0.7811, respectively. The reaction mechanism can be hypothesized as involving the rapid generation of numerous nucleation sites on the surface of solid AC, where surface reactions occur, with the movement of reaction interface governing the reaction rate. Consequently, a kinetic equation accounting for the AC decomposition was developed and evaluated, and the heat absorption specific power under different temperature conditions was predicted.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179809"},"PeriodicalIF":3.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Valorization of a high-sulfur petroleum coke for energy and fuels through its co-processing with a forest waste, using concrete wastes for sulphur and carbon dioxide capture under mild conditions","authors":"D. Vamvuka,&nbsp;K. Zacheila","doi":"10.1016/j.tca.2024.179811","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179811","url":null,"abstract":"<div><p>Current work provided a comprehensive assessment on the pyrolysis, combustion and gasification of a high-sulfur pet coke (PEC) and its blends with a forest waste (FOP). The potential of waste concrete fractions to capture SO₂ and CO₂ emissions was explored. The experiments were conducted in a fixed bed system and a thermogravimetric-mass spectrometric unit. Thermal behavior, reactivity, conversion, synergy, structural and chemical characteristics of solid materials, quantitative analysis of products and heating value, chemical, mineralogical and fusibility analysis of ashes were studied as a function of temperature, blending ratio and sorbent/fuel ratio. Addition of sorbent at a ratio Ca/<em>S</em> = 2 resulted in a desulfurization extent of 76–81 % during combustion. Quarry dust sorbent captured up to 95.4 % of CO₂ emitted below 700 °C. At 1000 °C H₂ content was 64.8–72.9 % mol and syngas yield 1.1–1.8 m³/kg. The gasification performance of PEC was improved upon blending with FOP.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179811"},"PeriodicalIF":3.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Supertoughened biodegradable poly(L-lactic acid) by multiphase blends system: Crystallization, rheological and mechanical properties","authors":"Yujie Jin ,&nbsp;Jing Guo ,&nbsp;Hongda Cheng ,&nbsp;Yi Li ,&nbsp;Changyu Han","doi":"10.1016/j.tca.2024.179810","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179810","url":null,"abstract":"<div><p>To toughen brittle poly(L-lactic acid) (PLA), poly(3-hydroxybutyrate-<em>co</em>-3-hydroxyhexanoate) (PHBH) and poly(vinyl acetate) (PVAc) were introduced into PLA matrix to prepared PLA/PHBH/PVAc ternary blends. PVAc was electively located in PLA matrix and refined phase morphology owing to better miscibility of PVAc with PLA than with PHBH. Increase in PVAc content decreased the crystallization rate and the crystallinity of PLA due to the dilution effect. More importantly, prominent enhancement of flexibility and toughness of PLA was obtained by the addition of PHBH and PVAc. Elongation at the break and impact strength of ternary blend with 10 wt% PVAc were 277 % and 326 % higher than that of neat PLA. Melt viscoelasticity of PLA was improved by incorporation of PHBH and PVAc. The combination of increased toughness and high melt viscoelasticity established in PLA biodegradable blends represent properties required in a wider range of applications.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179810"},"PeriodicalIF":3.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Addressing co-occurring conditions in behavioural therapy for tic disorders: a review and guideline.","authors":"Charlotte Sanderson, Cara Verdellen, Nanette Debes, Zsanett Tárnok, Jolande van de Griendt, Sharon Zimmerman-Brenner, Tara Murphy","doi":"10.1007/s00787-022-02097-1","DOIUrl":"10.1007/s00787-022-02097-1","url":null,"abstract":"<p><p>Co-occurring psychiatric conditions are very common in tic disorders and Tourette syndrome. These additional symptoms are often detrimental to quality of life and may impact upon the implementation and efficacy of evidence-based behavioural therapies (BT) for tics. Combining a review of the available literature, relevant theory, and expert clinical practice, we present a guideline for implementing behavioural and psychosocial interventions when common comorbidities are present. These include attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), anxiety, disruptive behaviour, autism spectrum disorder (ASD) and depression. Practical recommendations are provided for assessment, formulation and management of specific and multiple comorbidities in BT for both children and adults. Despite comorbidities being common in tic disorders, few studies have comprehensively addressed how they may influence the efficacy or implementation of existing therapies or how such treatments may need to be modified or sequenced. We outline recommendations for future research, including randomised control trials of BT for those with specific or multiple comorbidities, as well as adequately powered sub-group analyses within larger scale trials or naturalistic study designs. Transdiagnostic models of psychiatric disorders and treatment, including modular cross-diagnostic therapies, which recognise the dimensionality of psychiatric disorders are also highlighted as an important focus in treatment development in tic disorders.</p>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"501 1","pages":"2111-2127"},"PeriodicalIF":6.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77057459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photopyroelectric Techniques for Thermal Diffusivity and Optical Absorption Coefficient Measurements of SiO2 Colloids","authors":"C. Proa-Coronado,&nbsp;J.A. Balderas-López,&nbsp;Y. Sánchez-Fuentes,&nbsp;L.A. Linares-Duarte,&nbsp;E. Hernández-Sánchez","doi":"10.1016/j.tca.2024.179806","DOIUrl":"https://doi.org/10.1016/j.tca.2024.179806","url":null,"abstract":"<div><p>In this work Photopyroelectric Techniques for thermal and optical characterization are introduced for measuring thermal diffusivity and optical absorption coefficient of colloidal suspensions of SiO₂. Thermal diffusivity and Optical absorption coefficients at 904 nm, 940 nm, 980 nm and 1550 nm were measured for spherical SiO₂ colloidal suspensions of 61 and 673 nm average size, in a range of 1 mg/mL to 26 mg/mL. It was found a linear increment of this optical property with SiO₂ nano-spheres concentration, which was not possible to obtain by means of absorbance measurements with conventional UV-Vis spectroscopy; in relation with thermal diffusivity it was found a slightly increment of this thermal property with increasing concentration, however this increment was not as large as the one reported for similar samples but using experimental techniques involving the optical properties of the samples. The direct measurement of optical absorption coefficients of colloidal suspensions allowed the knowledge of their absorptivity at the selected wavelengths. The presented methodology could be useful for measuring this optical property for colloidal suspensions in general at other wavelengths and as a function of other variables of interest, such as size particle.</p></div>","PeriodicalId":23058,"journal":{"name":"Thermochimica Acta","volume":"739 ","pages":"Article 179806"},"PeriodicalIF":3.1,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141596897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}