Temperature effect in physicochemical and bioactive behavior of biogenic hydroxyapatite obtained from porcine bones

AbstractBiogenic hydroxyapatite (BHAp) is a widely used material in the biomedical area due to its similarities with the bone tissue mineral phase. Several works have been spotlighted on the thermal behavior of bone. However, little research has focused on determining the influence of calcination temperature in the physicochemical and bioactive properties of BHAp. In this work, a study of the physicochemical properties’ changes and bioactive response of BHAp produced from porcine femur bones using calcination temperatures between 900 to 1200 °C was conducted. The samples’ structural, morphological, and compositional changes were determined using XRD, SEM, and FTIR techniques. XRD results identified three temperature ranges, in which there are structural changes in BHAp samples and the presence of additional phases. Moreover, FTIR results corroborated that B-type substitution is promoted by increasing the heat treatment temperature. Likewise, samples were immersed in a simulated biological fluid (SBF), following the methodology described by Kokubo and using ISO 23317:2014 standard, for 3 and 7 days. FTIR and SEM results determined that the highest reaction velocity was reached for samples above 1000 °C, due to intensity increasing of phosphate and carbonate bands and bone-like apatite morphologies, compared to other temperatures evaluated.

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Benthic estuarine communities' contribution to bioturbation under the experimental effect of marine heatwaves

Scientific Reports ◽

10.1038/s41598-021-90720-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

M. Dolbeth ◽

O. Babe ◽

D. A. Costa ◽

A. P. Mucha ◽

P. G. Cardoso ◽

...

Keyword(s):

Community Composition ◽

Ecosystem Functioning ◽

Structural Changes ◽

Nutrient Release ◽

Biological Communities ◽

Thermal Change ◽

Composition And Structure ◽

Temperature Ranges ◽

Negative Impacts ◽

Heat Extremes

AbstractMarine heatwaves are increasing worldwide, with several negative impacts on biological communities and ecosystems. This 24-day study tested heatwaves' effect with distinct duration and recovery periods on benthic estuarine communities' diversity and contribution to ecosystem functioning experimentally. The communities were obtained from a temperate estuary, usually subjected to high daily thermal amplitudes. Our goal was to understand the communities' response to the thermal change, including the community descriptors and behavioural changes expected during heat extremes. We measured community composition and structural changes and the bioturbation process and nutrient release as ecosystem functioning measurements. Overall, our findings highlight the potential tolerance of studied estuarine species to the temperature ranges tested in the study, as community composition and structure were similar, independently of the warming effect. We detected a slight trend for bioturbation and nutrient release increase in the communities under warming, yet these responses were not consistent with the heatwaves exposure duration. Overall, we conclude on the complexity of estuarine communities’ contribution to functioning under warming, and the importance of scalable experiments with benthic organisms' responses to climate variability, accommodating longer time scales and replication. Such an approach would set more efficient expectations towards climate change mitigation or adaptation in temperate estuarine ecosystems.

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Effects of Supercritical CO2 Treatment Temperature on Functional Groups and Pore Structure of Coals

Sustainability ◽

10.3390/su11247180 ◽

2019 ◽

Vol 11 (24) ◽

pp. 7180

Author(s):

Zhaolong Ge ◽

Mengru Zeng ◽

Yugang Cheng ◽

Haoming Wang ◽

Xianfeng Liu

Keyword(s):

Pore Structure ◽

Functional Groups ◽

Coalbed Methane ◽

Co2 Sequestration ◽

Structural Changes ◽

Fractal Theory ◽

Treatment Temperature ◽

Attenuated Total Reflection ◽

Enhancement Effect ◽

Methane Recovery

The buried depth of a coal seam determines the temperature at which CO2 and coal interact. To better understand CO2 sequestration, the pore structure and organic functional groups of coal treated with different ScCO2 temperatures were studied. In this study, three different rank coals were treated with ScCO2 at different temperatures under 8 MPa for 96 h in a geochemical reactor. The changes in pore structure and chemical structure of coal after ScCO2 treatment were analyzed using mercury intrusion porosimetry, attenuated total reflection Fourier transform infra-red spectroscopy, fractal theory, and curve fitting. The results show that the enhancement effect of ScCO2 on pore structure of coal becomes less significant as the increase of buried depth. In most of the treated coal samples, the variation proportion of mesopores decreased and the variation proportion of macropores increased. In the relatively higher rank coals, the degree of condensation (DOC) of aromatic rings decreased after treatment with ScCO2. The DOC values showed a U-shape relationship with temperature, and the aromaticity showed a downward trend with increasing temperature. The chemical structural changes in the relatively lower rank coal sample were complex. These findings will provide an understanding of mechanisms relevant to CO2 sequestration with enhanced coalbed methane recovery under different geothermal gradients and for different ranks of coal.

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Comparative Thermodynamic Analysis of the Behavior of C60 and C28 Fullerenes when Heated in an Inert Medium

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.854.151 ◽

2020 ◽

Vol 854 ◽

pp. 151-157 ◽

Cited By ~ 1

Author(s):

Nikolay M. Barbin ◽

Vasiliy P. Dan ◽

Dmitriy I. Terentyev ◽

Sergey G. Alexeev

Keyword(s):

Gas Phase ◽

Structural Changes ◽

Molar Mass ◽

Total Enthalpy ◽

Thermophysical Parameters ◽

Temperature Ranges ◽

Volume Entropy ◽

Energy Equilibrium ◽

Scale Experiment ◽

Increasing Temperature

The structural changes of condensed fullerenes C60 and C28 at a temperature increase from 200 K to 2000 K have been studied by computational methods using the TERRA software for carbon-argon systems. The processes of destruction of fullerenes C60 and C28 molecules are presented, and the temperature ranges of their thermal stability are determined: up to 1000 K and up to 400 K, respectively. The following thermophysical parameters of the C60-Ar and C28-Ar systems are considered: specific volume, entropy, total enthalpy, total internal energy, equilibrium specific heat, molar mass of the gas phase, gas constant, and mass fraction of the condensed phase. A comparative analysis of their changes with increasing temperature is carried out. The results obtained in the course of thermodynamic modeling are similar to the results of a full-scale experiment conducted under similar conditions. In the future, the obtained data can be used to determine the explosive and fire-hazardous properties of fullerenes as a dispersed solid.

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Effects of aluminum sulfate soaking pretreatment on dimensional stability and thermostability of heat-treated wood

European Journal of Wood and Wood Products ◽

10.1007/s00107-020-01616-8 ◽

2020 ◽

Author(s):

Lijie Qu ◽

Zhenyu Wang ◽

Jing Qian ◽

Zhengbin He ◽

Songlin Yi

Keyword(s):

Heat Treatment ◽

Thermal Stability ◽

Thermal Degradation ◽

Structural Changes ◽

Aluminum Sulfate ◽

Treated Wood ◽

Treatment Temperature ◽

Chinese Fir ◽

Heat Treated ◽

Thermal Stability Of

Abstract Acidic aluminum sulfate hydrolysis solutions can be used to catalyze the thermal degradation of wood in a mild temperature environment, and thus reduce the temperature required for heat treatment process. To improve the dimensional and thermal stability of Chinese fir during heat treatment at 120 °C, 140 °C and 160 °C, this study investigated the effects of soaking pretreatment with 5%, 10% and 15% aluminum sulfate on the chemical and structural changes of the heat-treated Chinese fir. The results indicated that the samples treated at 15% aluminum sulfate concentration and 160 °C heat treatment achieved the best dimensional and thermal stability. Chemical analyses by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) indicated that the catalysis of aluminum sulfate resulted in degradation of hemicelluloses during the heat treatment, and an increase in the soaking concentration and heat treatment temperature also affected the thermal degradation of celluloses. The scanning electron microscope (SEM) and mass changes test results proved that the hydrolyzed aluminum flocs mainly adhered to the inner wall of the wood tracheid as spherical precipitates, and when the soaking concentration reached 10% and 15%, a uniform soaking effect could be achieved. The thermogravimetric (TG) analysis revealed the soaking pretreatment effectively improved the thermal stability of the heat-treated wood by physically wrapping and promoting the formation of a carbon layer on the wood surface during heat treatment. Thus, aluminum sulfate soaking pretreatment exerted a great effect on the dimensional and thermal stability of wood, allowing heat treatment to be performed at a lower temperature.

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Determination of the effect of exposure conducted in KOH solutions at different temperatures on the properties of electrochromic Ni(OH)2-PVA films

Eastern-European Journal of Enterprise Technologies ◽

10.15587/1729-4061.2021.239151 ◽

2021 ◽

Vol 4 (6(112)) ◽

pp. 60-66

Author(s):

Valerii Kotok ◽

Vadym Kovalenko ◽

Rovil Nafeev ◽

Volodymyr Verbitskiy ◽

Elena Lominoga ◽

...

Keyword(s):

Treatment Temperature ◽

Electrochemical Activity ◽

Operating Conditions ◽

Electrochromic Device ◽

Electrochemical Characteristics ◽

Composite Electrodes ◽

Hot Climate ◽

Different Temperatures ◽

Temperature Ranges ◽

Electrochemical Cycling

To determine the effect of exposure of film composite electrodes based on Ni(OH)2-polyvinyl alcohol to an alkaline solution at high temperatures on the electrochromic and electrochemical characteristics, a series of films was obtained. The films were obtained on a glass substrate coated with fluorine-doped tin oxide. The coating of the substrates was carried out by the cathodic template method under the same conditions. The resulting precipitates were treated by keeping them in an alkali solution at different temperatures: 30, 40, 50, 60, and 70 °C for 8 hours, thereby simulating the operating conditions of an electrochromic device in a hot climate. It was found that the exposure temperature directly affected the electrochemical and electrochromic properties of the treated films. In this case, the cyclic volt-ampere curves showed a decrease in the peak values of the current densities and a lower rate of establishment of characteristics with an increase in the treatment temperature. At a maximum treatment temperature of 70 °C, the properties of the film significantly changed towards deterioration. According to the results of the experiments, three temperature ranges of treatment were identified. The first one was in the range up to 40 °C, in which the films showed significant electrochromic and electrochemical activity after treatment. The second interval was between 40 and 60 °C, in which the coatings showed a reversible deterioration in electrochromic and electrochemical activity. After treatment in the second interval, the films gradually restored their performance during electrochemical cycling. The third interval was from 70 °C and above. The films treated in this temperature range irreversibly lost their electrochemical and electrochromic activity. The study also proposed mechanisms to explain changes in the characteristics of electrodes during treatment, as well as possible ways to combat temperature degradation.

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EELS of laser-irradiated kapton polymide

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100150356 ◽

1993 ◽

Vol 51 ◽

pp. 904-905

Author(s):

J. Bentley ◽

H.M. Phillips ◽

D.L. Callahan ◽

R. Sauerbrey

Keyword(s):

Electron Microscopy ◽

Structural Changes ◽

Analytical Electron Microscopy ◽

Formation Mechanisms ◽

Electrically Conducting ◽

Transmission Electron ◽

Electron Energy Loss Spectrometry ◽

Direct Laser ◽

Compositional Changes ◽

Beam Damage

It has recently been demonstrated that the electrical resistivity of a high temperature polymer, polyimide, can be changed permanently from 1017 Ωcm to 10-1 Ωcm by KrF (248 nm) excimer laser irradiation. Further, using a holographic technique, an array of 500-nm-wide electrically conducting wires has been produced on polyimide by direct laser ablation. There is obvious interest in exploiting this phenomenon to create integrated microelectronic devices with conventional polymers as both dielectrics and conductors. The imaging of such patterned nanostructures by scanning and transmission electron microscopy (SEM and TEM) is reported elsewhere. Knowledge of compositional changes that accompany the structural changes is necessary for understanding formation mechanisms, but analytical electron microscopy (AEM) of polymers is usually severely limited by electron beam damage effects, especially when high spatial resolution microanalysis is attempted with focussed probes. However, parallel-detection electron energy-loss spectrometry (PEELS) has been successfully used to investigate laser-induced compositional changes in polyimide (Kapton™, E.I. Dupont) with no apparent signs of beam damage.

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Effects of Thermal Treatment on Natural Clinoptilolite-Rich Zeolite Behavior in Simulated Biological Fluids

Molecules ◽

10.3390/molecules25112570 ◽

2020 ◽

Vol 25 (11) ◽

pp. 2570

Author(s):

Oana Cadar ◽

Marin Senila ◽

Maria-Alexandra Hoaghia ◽

Daniela Scurtu ◽

Ion Miu ◽

...

Keyword(s):

Thermal Treatment ◽

Crystalline Structure ◽

Structural Changes ◽

Biological Fluids ◽

Treatment Temperature ◽

Simulated Gastric Fluid ◽

Gravimetric Analysis ◽

X Ray ◽

Ft Ir ◽

Thermally Treated

This study presents the effect of thermal treatment (450, 500, 600, 750, and 800 °C) on a Romanian clinoptilolite-rich natural zeolite, along with the interaction of raw and thermally treated zeolites with simulated gastric fluid (SGF, pH = 1.20) at different zeolite to SGF ratios and exposure times. The zeolites were characterized using gravimetric analysis, X-ray fluorescence, powder X-ray diffraction (pXRD), and Fourier transform infrared (FT-IR) spectroscopy. The chemical composition of the zeolite subjected to thermal treatment did not change significantly with the increase of temperature. Structural changes were not detectable by pXRD and FT-IR analyses in the zeolites thermally treated up to 500 °C, while above 600 °C a gradual structural breakdown of zeolite was noticed. At high temperatures, the broad, low-intensity peaks in pXRD patterns indicated the partial amorphization of the crystalline structure. The pXRD and FT-IR analyses showed that the crystalline structure of zeolites remains unaffected after their exposure to SGF. The results revealed that the amounts of Fe, Na, Mg, K, Ca, Al, and Si released depends mainly on the zeolite to SGF ratio, and to a lower extent on the thermal treatment temperature, while the exposure time of 1 to 7 days does not have a significant impact on the elements released in SGF.

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Anatomical changes to the wood of Croton sonderianus (Euphorbiaceae) when charred at different temperatures

IAWA Journal ◽

10.1163/22941932-20170161 ◽

2017 ◽

Vol 38 (1) ◽

pp. 117-123 ◽

Cited By ~ 6

Author(s):

Peter Gasson ◽

Caroline Cartwright ◽

Claudia Luizon Dias Leme

Keyword(s):

Moisture Content ◽

Ambient Temperature ◽

Cell Walls ◽

Structural Changes ◽

Middle Lamella ◽

Treatment Temperature ◽

Anatomical Characteristics ◽

Anatomical Changes ◽

Different Temperatures ◽

Two Temperatures

Wood retains most of its anatomical characteristics when charred, but charring temperature determines the appearance of the resulting charcoal and this depends largely on the proportions and distribution of the constituent vessels, fibres and parenchyma, as well as moisture content. This study describes the structural changes in the charcoal of the wood of Croton sonderianus Muell. Arg. at two temperatures, 400 °C or 600 °C. This species is an important source of charcoal in the caatinga of the northeast part of Brazil. The samples were heated for ten minutes to reach treatment temperature, charred for two hours at either 400 °C or 600 °C and then left to cool to ambient temperature for 30 to 60 minutes. Our observations showed that most of the changes occurred when charcoal was produced at 600 °C, but the qualitative features necessary for identification were retained. At this temperature, cells lost their circular shape, became angular and occasionally amorphous, the middle lamella disappeared and the walls of adjacent cells coalesced, cell walls became thinner, and the prismatic crystals developed cracks and became porous. Our findings are compared with those for two previously studied Mimosa species which have an entirely different anatomy.

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Heat Treatment of AlZn10Si7MgCu Alloy and its Effect on Change of Mechanical Properties

Archives of Foundry Engineering ◽

10.2478/v10266-012-0051-8 ◽

2012 ◽

Vol 12 (2) ◽

pp. 135-138 ◽

Cited By ~ 5

Author(s):

J. Pezda

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Treatment Temperature ◽

Optimal Parameters ◽

Electric Resistance ◽

Resistance Furnace ◽

Electric Resistance Furnace ◽

Temperature Ranges ◽

Testing Work

Heat Treatment of AlZn10Si7MgCu Alloy and its Effect on Change of Mechanical Properties The most important parameters which predetermine mechanical properties of a material in aspects of suitability for castings to machinery components are: tensile strength (Rm), elongation (A5, hardness (HB) and impact strength (KCV). Heat treatment of aluminum alloys is performed to increase mechanical properties of the alloys mainly. The paper comprises a testing work concerning effect of heat treatment process consisting of solution heat treatment and natural ageing on mechanical properties and structure of AlZn10Si7MgCu alloy moulded in metal moulds. Investigated alloy was melted in an electric resistance furnace. Run of crystallization was presented with use of thermal-derivative method (ATD). This method was also implemented to determination of heat treatment temperature ranges of the alloy. Performed investigations have enabled determination of heat treatment parameters' range, which conditions suitable mechanical properties of the investigated alloy. Further investigations will be connected with determination of optimal parameters of T6 heat treatment of the investigated alloy and their effect on change of structure and mechanical/technological properties of the investigated alloy.

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Biomarkers of Joint Damage in Osteoarthritis: Current Status and Future Directions

Mediators of Inflammation ◽

10.1155/2021/5574582 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Rajkamal Kumavat ◽

Vijay Kumar ◽

Rajesh Malhotra ◽

Hemant Pandit ◽

Elena Jones ◽

...

Keyword(s):

Disease Progression ◽

Structural Changes ◽

Early Stage ◽

Biological Fluid ◽

Joint Damage ◽

New Drugs ◽

Current Status ◽

Low Grade ◽

Loss Of Function ◽

Short Period

Osteoarthritis (OA) is a disease of the whole joint organ, characterized by the loss of cartilage, and structural changes in bone including the formation of osteophytes, causing disability and loss of function. It is also associated with systemic mediators and low-grade inflammation. Currently, there is negligible/no availability of specific biomarkers that can be used to facilitate the diagnosis and treatment of OA. The most unmet clinical need is, however, related to the monitoring of disease progression over a short period that can be used in clinical trials. In this review, the value of biomarkers identified over the past decade has been highlighted. These biomarkers are associated with the synthesis and breakdown of cartilage, including collagenous and noncollagenous biomarkers, inflammatory and anti-inflammatory biomarkers, expressed in the biological fluid such as serum, synovial fluid, and urine. Broad validation of novel and clinically applicable biomarkers and their involvement in the pathways are particularly needed for early-stage diagnosis, monitoring disease progression, and severity and examining new drugs to mitigate the effects of this highly prevalent and debilitating condition.

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