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This study aimed to explore the relationship between the Sirtuin 3 (SIRT3) gene and endothelial cell dysfunction, contributing to the progression of coronary atherosclerosis driven by hyperglycemia.We measured serum SIRT3 levels using enzyme-linked immunosorbent assay in 95 patients with type 2 diabetes mellitus (T2DM) who underwent diagnostic coronary angiography. The patients were divided into two groups according to the presence (n = 45) or absence (n = 50) of coronary artery disease (CAD). Human aortic endothelial cells (HAECs) grown in vitro in a medium with various concentrations of glucose (5.5, 11, 16.5, 22, 27.5, 33, and 38.5 mM) for 24 h were assessed for protein expression of SIRT3, peroxisome proliferator-activated receptor alpha (PPAR-α), endothelial nitric oxide (NO) synthase (eNOS), and inducible NO synthase (iNOS) using Western blot analysis. HAECs were subjected to SIRT3 overexpression or inhibition through SIRT3 adenovirus and siRNA transfection.Serum SIRT3 levels were significantly lower in T2DM patients with CAD than in those without CAD (p = 0.048). The in vitro results showed that HG significantly increased SIRT3, PPAR-α, and eNOS protein expression in a concentration-dependent manner. Moreover, iNOS expression was decreased in HAECs in response to HG. Reduced PPAR-α and eNOS levels and increased iNOS levels were observed in SIRT3 silenced HAECs cells. In contrast, SIRT3 overexpression significantly improved PPAR-α and eNOS expression and suppressed iNOS expression.SIRT3 was associated with the progression of atherosclerosis in T2DM patients through upregulation of PPAR-α and eNOS and downregulation of iNOS, which are involved in endothelial dysfunction under hyperglycemic conditions.

A series of Sm3+-doped La3Si6N11 phosphor materials were synthesized by a high temperature solid-state reaction method. The crystal structure, microstructure, photoluminescence properties, decay curves as well as thermal quenching properties of the as-prepared phosphors were investigated systematically. The excitation spectra contain a wide asymmetric band below 350 nm originating from the host absorption, several sharp excitation peaks in the range of 300–550 nm corresponding to f-f transition of Sm3+. Under the excitation of 369 and 414 nm light, the phosphors exhibit strong narrow-band orange-red emission peaked at 605 nm. The average decay time of La2.99Si6N11:0.01Sm3+ sample is fitted to be 0.38 ms and the CIE coordinates were calculated to be (0.6105, 0.3833). For water resistance, La3Si6N11:Sm3+ is better than K2SiF6:Mn4+ phosphor. After soaking in deionized water for 300 min, the La3Si6N11:Sm3+ sample retains approximately 80% of its initial relative emission intensity. When the temperature rises to 423 K (150 °C), the emission intensity of La2.99Si6N11:0.01Sm3+ sample remains 85% in comparison to that of room temperature. The activation energy was calculated to be 0.63253 eV, which is higher than those of Sm3+-activated oxide phosphors, indicating that the phosphor has relatively good thermal stability.

To facilitate the reuse and recycling of polyvinyl chloride (PVC) to achieve sustainable development and new industrialization, the composition and mechanism of formation of volatiles during the flash pyrolysis of PVC were studied by thermogravimetry-Fourier transform infrared (TG-FTIR) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). TG and derivative thermogravimetry (DTG) analyses indicated two main degradation stages during flash pyrolysis of PVC, namely dehydrochlorination of PVC and decomposition of dechlorinated-PVC. Simultaneously, the FTIR results revealed that the main functional groups in the pyrolysis process were H–Cl, -C-Cl, C–H, C H, and aromatic groups. The relative content of main volatiles was determined by Py-GC/MS, and decreased in the following order: aromatics > alkenes > hydrogen chloride (HCl) > chlorinated hydrocarbons. Specifically, the relative content of aromatics was as high as 76.790–81.809%, while that of HCl was in the range of 3.016–3.096%. The carbon number distribution and the relative content of main products obtained from the flash pyrolysis of PVC at different final temperatures were also analysed. According to the experimental results, the mechanism of formation of the main volatiles based on free-radical reactions was deduced in detail. Therefore, this study provides further details for deepening the understanding of the PVC pyrolysis process.

Eu2+-activated BaSi2O2N2 oxonitridosilicate phosphor is an efficient cyan compensator to improve the color rendering index of WLEDs for full-spectrum lighting. However, the low luminescent efficiency and poor thermal stability of this type of phosphor severely restrict its practical industry applications. Herein, SiC was proposed into the preparation process of BaSi2O2N2 to enhance the luminescence and thermal stability. Due to the very small amount of SiC addition, the samples of BaSi2O2N2-4x/3Cx:Eu2+ maintain the orthorhombic crystal structure of BaSi2O2N2:Eu2+, but the unit cell volumes and particle sizes become larger. The luminescent intensity reaches the maximum when x = 0.075 and the absorption efficiency and internal quantum efficiency are 67.59% and 58.26%, which are increased by 5.34% and 14.66% relative to the SiC-free sample, respectively. The bandgap and lifetime of Ba0.97Si2O2N1.9C0.075:0.03Eu2+ are calculated to be 2.06 eV and 407.91 ns, respectively. The sample of Ba0.97Si2O2N1.9C0.075:0.03Eu2+ possesses a higher activation energy of 0.383 eV and exhibits a little loss of 13.3% of luminescence intensity at 423 K, which is improved by 11.4% relative to the SiC-free sample. Higher structural stiffness derived from the partially replacement of Si−N bonds by Si-C is supposed as the main reason of the higher thermal stability. The luminescence of Ba0.97Si2O2N1.9C0.075:0.03Eu2+ degrades only by 4.64% in five thermal cycles, which mainly thanks to the improved antioxidant of Eu2+. The Ba0.97Si2O2N1.9C0.075:0.03Eu2+ sample demonstrates an excellent color stability with a tiny chromaticity shift of ~28.19 × 10-3 ranging from 298 to 423 K. A WLED with the cyan-emitting Ba0.97Si2O2N1.9C0.075:0.03Eu2+ exhibits a full spectrum with CRI of 95.1.

Ambient fine particulate matter (PM2.5) poses great risk to human health worldwide. Pulmonary oxidative stress is considered to be a vital step in PM2.5 triggered adverse health effects. Many in vitro studies have demonstrated that PM2.5 could induce oxidative stress in lung epithelia or macrophages but few studies have explored the difference between these two types of cells when estimating PM2.5 caused pulmonary oxidative stress. In this study, we compared the oxidative stress intensity between lung epithelial cells (A549) and monocyte-macrophage cells (Raw264.7) after PM2.5 treatments and explored the major generation mechanism of ROS in both cell lines. We found that Raw264.7 was more sensitive to PM2.5-induced cytotoxicity than A549; however, PM2.5 caused much greater oxidative stress in A549 compared with in Raw264.7. Moreover, we found that production of ROS via xanthine oxidase and nitric oxide synthase was involved in oxidative stress in A549 cells, while NADPH oxidase and nitric oxide synthase were the major sources of ROS generation in Raw264.7 cells. These observations suggested that lung epithelial cell is a more sensitive cell when estimating PM2.5-induced pulmonary oxidative stress in vitro.

Electrochemical N2 reduction reactions (NRR) and the N2 oxidation reaction (NOR), using H2 O and N2 , are a sustainable approach to N2 fixation. To date, owing to the chemical inertness of nitrogen, emerging electrocatalysts for the electrochemical NRR and NOR at room temperature and atmospheric pressure remain largely underexplored. Herein, a new-type Fe-SnO2 was designed as a Janus electrocatalyst for achieving highly efficient NRR and NOR catalysis. A high NH3 yield of 82.7 μg h-1 mgcat. -1 and a Faraday efficiency (FE) of 20.4 % were obtained for NRR. This catalyst can also serve as an excellent NOR electrocatalyst with a NO3 - yields of 42.9 μg h-1 mgcat. -1 and a FE of 0.84 %. By means of experiments and DFT calculations, it is revealed that the oxygen vacancy-anchored single-atom Fe can effectively adsorb and activate chemical inert N2 molecules, lowering the energy barrier for the vital breakage of N≡N and resulting in the enhanced N2 fixation performance.

There is a recognized need for cleaning the disposal of food scraps to maximize waste-to-energy conversion. The principal objective of this investigation was to carry out an in-depth analysis of th...

Electrochemical N

Background Our previous study has shown that Da0324, a curcumin analog, has significantly improved stability and antitumor activity. However, the molecular mechanisms of action of Da0324 remains poorly understood. Long non-coding RNA (lncRNA) has been certifed to play a key role in tumor progression. Here, we aim to investigate the molecular mechanisms underlying the anti-cancer activities of Da0324 through regulation of lncRNA HOTAIRM1. Methods Gastric cancer cell lines were treated with Da0324 and/or transfected with lentiviral vector expressing HOTAIRM1 shRNA, and/or miR-29b-1-5p mimics and/or small interference RNA (siRNA) against PHLPP1, or HOTAIRM1 siRNA or lentiviral vector expressing HOTAIRM1, as required. The expression of HOTAIRM1, miR-29b-1-5p and PHLPP1 in GC cells were determined by Real-Time PCR. Cell growth was examined by CCK-8 assay and colony formation assay in vitro. The targeted relationship between HOTAIRM1 and miR-29b-1-5p was verifed by luciferase reporter gene assay. Western blot was utilized to investigate PHLPP1 protein expression levels. Results Da0324 increased the expression of HOTAIRM1 in GC cells. HOTAIRM1 expression was significantly down-regulated in GC tissues, and the low expression of HOTAIRM1 was associated with the shorter survival rate of GC patients based on TCGA database. Knockdown of HOTAIRM1 promoted GC cell proliferation whereas overexpression of HOTAIRM1 inhibited GC cell proliferation as detected by CCK-8 and colony formation assays. Moreover, knockdown of HOTAIRM1 reversed the Da0324-mediated growth inhibition of GC cells. Furthermore, HOTAIRM1 acted as a sponge for miR-29b-1-5p and PHLPP1 is regulated by the HOTAIRM1/miR-29b-1-5p axis in GC cells. Overexpression of miR-29b-1-5p or knockdown of PHLPP1 reversed the ability of Da0324 to inhibit the growth of GC cells. Conclusions Our data suggest that Da0324 exerts antitumor activity by regulating HOTAIRM1/miR-29b-1-5p/PHLPP1 axis in GC cell, and provide new insights into the anti-cancer mechanism of Da0324.

Sulfate formation mechanisms have been discussed extensively but are still disputed. In this work, a year-long particulate matter (PM2.5) sampling campaign was conducted together with measurements of gaseous pollutant concentrations and meteorological parameters in Beijing, China, from March 2012 to February 2013. The sulfur oxidation ratio (SOR), an indicator of secondary sulfate formation, displayed a clear summer peak and winter valley, even though no obvious seasonal variations in sulfate mass concentration were observed. A rapid rise in the SOR was found at a relative humidity (RH) threshold of ∼45 % or an O3 concentration threshold of ∼35 ppb, allowing us to first introduce the idea that RH and O3 concentrations are two prerequisites for rapid sulfate formation via multiphase reactions. In the case of the RH threshold, this is consistent with current understanding of the multiphase formation of sulfate, since it relates to the semisolid-to-liquid phase transition of atmospheric aerosols. Correlation analysis between SOR and aerosol water content (AWC) further backed this up. In the case of the O3 concentration threshold, this is consistent with the consumption of liquid oxidants in multiphase sulfate formation. The thresholds introduced here lead us to a better understanding of the sulfate formation mechanisms and sulfate formation variations. H2O2 might be the major oxidant of sulfate formation, since another liquid-phase oxidant, O3, has previously been shown to be unimportant. The seasonal variations in sulfate formation could be accounted for by variations in the RH and O3 prerequisites. For example, over the year-long study, the fastest SO2-to-sulfate conversion occurred in summer, which was associated with the highest values of O3 (and also H2O2) concentration and RH. The SOR also displayed variations with pollution levels; i.e. the SOR increased with PM2.5 in all seasons. Such variations were primarily associated with a transition from the slow gas-phase formation of sulfate to rapid multiphase reactions, since RH increased higher than its prerequisite value of around 45 % as pollution evolved. In addition, the self-catalytic nature of sulfate formation (i.e. the formation of hydrophilic sulfate aerosols under high RH conditions results in an increase in aerosol water content, which results in greater particle volume for further multiphase sulfate formation) also contributed to variations among the pollution scenarios.

Nowadays, knowledge regarding component-specific inflammatory effect of fine particulate matter (PM2.5) is limited. In this study, an omics approach based on time-of-flight mass spectrometry was established to identify the key hydrophobic components of PM2.5 associated with pro-inflammatory cytokines released by macrophages after in vitro exposure. Of 764 compounds, 62 components were robustly screened with firmly identified 37 specific chemicals. In addition to polycyclic aromatic hydrocarbons (PAHs) and their methylated congeners, novel oxygen- and nitrogen-containing PAHs and, especially, oxygenated PAHs (Oxy-PAHs) were identified. Interleukin (IL)-6 was associated with Oxy-PAHs of 1,8-naphthalic anhydride, xanthone, and benzo[h]quinolone, especially, whereas IL-1β and tumor necrosis factor (TNF)-α were associated with most species. Most species were related to IL-1β, which was significantly higher in the heating season, with a monotonic dose-response pattern mainly for Oxy-PAHs and a U-shaped dose-response pattern for primary species. On the basis of the identified components, four sources of pollution (coal combustion, traffic emissions, biomass burning, and secondary formation, traced by Oxy-PAHs such as 1,8-naphthalic anhydride and quinones) were resolved by the positive matrix factorization model. TNF-α was associated with primary sources, whereas IL-1β and IL-6 were associated with both primary and secondary sources, suggesting different inflammatory effects between primary and secondary sources when assessing the toxicity-driven disparities of known and unknown PM2.5 components.

Nrf2 is an important transcription factor implicated in the oxidative stress response, which has been reported to play an important role in the way by which air pollution particulate matter (PM2.5) induces adverse health effects. This study investigates the mechanism by which Nrf2 exerts its protective effect in PM2.5 induced toxicity in lung cells. Lung cells silenced for Nrf2 (shNrf2) demonstrated diverse susceptibility to various PM extracts; water extracts containing high levels of dissolved metals exhibited higher capacity to generate mitochondrial reactive oxygen species (ROS) and hence increased oxidative stress levels. Organic extracts containing high levels of polycyclic aromatic hydrocarbons (PAHs) increased mortality and reduced ROS production in the silenced cells. shNrf2 cells exhibited a higher basal mitochondrial respiration rate compared to the control cells. Following exposure to water extracts, the mitochondrial respiration increased, which was not observed with the organic extracts. shNrf2 cells exposed to the organic extracts showed lower mitochondrial membrane potential and lower mtDNA copy number. Nrf2 may act as a signaling mediator for the mitochondria function following PM2.5 exposure.

The aim of this work was to study the pyrolysis behavior of castor oil, corn starch, soy protein, lignin, xylan, and cellulose. The pyrolysis behavior, gaseous product evolution, kinetics and thermodynamics of these model compounds were investigated via TG-FTIR under high heating rates. The TG/DTG curves showed that castor oil had the widest pyrolysis temperature zone and lignin had the highest residual rate. The apparent activation energy of these model compounds was calculated by Kissinger-Akahira-Sunose method. The kinetic results revealed that the average bond energy of chemical compositions was in the order of lipid > lignin > starch > cellulose > protein > hemicellulose. The pre-exponential factor analysis showed that there were a large number of surface reactions for soy protein and xylan during pyrolysis, however other model compounds were not surface controlled. The thermodynamic parameters including G, ΔS, ΔH for six model compounds were also calculated.

In this work, the effects of heating rate on fast pyrolysis behavior and product distribution of Jerusalem artichoke stalk (JAS) were investigated fist by TG-FTIR (heating rates: 20, 30, 50, 100, 300, 500 °C/min) and then via Py-GC/MS (heating rates: 100, 1000, 5000 10000 °C/s). The results showed that with the heating rate increased, TG and DTG curves obviously shifted toward the high-temperature range, and the number of peaks in DTG curves reduced from three to two. The model-free method indicated that the apparent activation energy of JAS pyrolysis was 286 kJ/mol at the low heating rate and increased to 351 kJ/mol at the high heating rate. The distributed activation energy model showed that the value of pre-exponential factor increased with the heating rate increased and the kinetic compensation effect was obvious during the conversion from 0.3 to 0.7. Total 44 compounds were identified by GC/MS. Acid, phenol and carbonyl compounds were the major products groups. With the heating rate increased, the relative contents of acid increased whereas the relative contents of phenolic substance decreased. The yield of carbonyl compounds was maximum at the heating rate of 5000 °C/s.

Effective catalysts with sufficient activity and selectivity are essential for the nitrogen reduction reaction (NRR). Many fruitful NRR electrocatalysts have been investigated with regard to NH3 production under ambient conditions in recent years. However, well-defined and modifiable molecular catalysts have rarely been reported for the NRR to date. Here, molecular FePc was grafted on an O-MWCNT surface as a NRR electrocatalyst to improve its recyclability. This catalyst displayed high electrocatalytic ability and selectivity, giving a large NH3 yield of 36 μg h−1 mg−1 cat., a FE of 9.73% and a turnover number (TON) of 12.56 after 2 h of electrocatalytic reaction in an acidic electrolyte, superior to most of the reported materials. DFT calculations indicated that the NRR preferentially proceeded along the alternate pathway, the activation of N2 to produce N2H* is the rate-limiting step with a ΔG value of 1.79 eV. Conclusively, we report FePc/O-MWCNT as a low-cost, high-efficiency NRR catalyst that also offers a valuable reference for molecular electrocatalyst research in electrochemical nitrogen reduction.

The chemical properties, pyrolysis behaviors and pyrolysis product distributions of Shenmu (SM) coal were investigated by proximate and ultimate analysis, thermogravimetric analyzer coupled with Fourier transform infrared spectroscopy (TG-FTIR) and Pyrolyzer coupled with gas chromatography/mass spectrometry (Py-GC/MS). The results of the proximate and ultimate analysis indicated that SM coal had less saturated aliphatic structures and more polar components. The coke yield for SM coal during pyrolysis process at 100 °C/min, 300 °C/min, and 500 °C/min was 65.60%, 64.19%, and 63.15%, respectively, which indicating that the increment in heating rates could promote the production of volatile substances. Moreover, there was a lateral shift to high temperature of TG/DTG curves when the heating rates increasing. The main volatile species detected from FTIR in the pyrolysis of SM coal were CO2, CO, CH4, C2H4, C2+ aliphatics, light arenes, C O bond containing species and C O bond containing species. Since the difference in the temperature intervals of those volatile species released, the sources of cleavage or chain scission during pyrolysis process were not the same. According to the fast pyrolysis by Py GC/MS, the volatile species could be divided into eleven species including alkenes, cycloalkenes, alkanes, cycloalkanes, aromatics, phenols, ethers, ketones, alcohols, N-containing species, and other species. The relative contents of alkenes and alkanes were dominant regardless of the variegation of heating rate, residence time and pyrolysis final temperature. Furthermore, the trend of each species under different influence factor conditions achieved different tunes rendered with equal skill.

There is a lack of detailed research on the production of isoprene and D-limonene by solid base-catalysed thermal depolymerization of waste tires (WTs). This work aimed to investigate the thermal decomposition characteristics, reaction kinetics, high value-added products production and potential mechanisms during WT pyrolysis in the presence of calcium oxide (CaO) via Thermogravimetry-Fourier Transform Infrared spectrometer (TG-FTIR) and Pyrolyzer-Gas Chromatography/Mass spectrometry (Py-GC/MS). The results obtained from TG indicated that CaO accelerated depolymerization in terms of reducing the reaction temperature, which is also reflected in the kinetic parameters. It can be found that the content of D-limonene increased by 13.76% and that of isoprene increased by 37.57%, which were attributed to differences in the depolymerization mechanisms in the presence of CaO. Furthermore, CaO had a profound impact on desulfurization by reducing benzothiazole, sulfoacid, and thiophene. The potential catalytic mechanisms of isoprene and D-limonene production and desulfurization were also proposed. This work deepens the understanding of the catalytic pyrolysis of WT under CaO and unambiguously demonstrates the great potential of CaO in enhancing isoprene and D-limonene production, providing new insight for the cleaner production of high value-added products from WT.

The development of non-noble metal catalysts for hydrogen revolution in alkaline media is highly desirable, but remains a great challenge. Herein, synergetic ultrathin NiO/MoS2 catalysts were prepared to improve the sluggish water dissociation step for HER in alkaline conditions. With traditional electrode assembly methods, MoS2:NiO-3:1 exhibited the best catalytic performance; an overpotential of 158 mV was required to achieve a current density of 10 mA/cm2. Further, a synergetic ultrathin NiO/MoS2/nickel foam (NF) electrode was assembled by electrophoretic deposition (EPD) and post-processing reactions. The electrode displayed higher electrocatalytic ability and stability, and an overpotential of only 121 mV was needed to achieve a current density of 10 mA/cm2. The improvement was ascribed to the better catalytic environment, rather than a larger active surface area, a higher density of exposed active sites or other factors. DFT calculations indicated that the hybrid NiO/MoS2 heterostuctured interface is advantageous for the enhanced water dissociation step and the corresponding lower kinetic energy barrier—from 1.53 to 0.81 eV.

Curcumin is a safe, cost-effective natural agent with multiple targets that displays therapeutic potential in cancer. Recently, we reported a novel curcumin analog, Da0324, which exhibited significantly improved stability and anti-cancer activity. However, the molecular mechanism underlying the anti-cancer activity of Da0324 remains largely unknown. Long non-coding RNAs have been shown to play important roles in cancer development and progression and may be potential targets for cancer therapy. Here, we showed that Da0324 treatment down-regulated the expression of LINC01021 in gastric cancer cells. Da0324 treatment or knockdown of LINC01021 by antisense oligos significantly inhibited gastric cancer cell growth, and also up-regulated P53 expression and down-regulated Bcl-2 expression in vitro and in vivo. Furthermore, Da0324 treatment or knockdown of LINC01021 in gastric cancer cells suppressed cell migration, invasion and epithelial-mesenchymal transition (EMT), as well as induced apoptosis and autophagy. In addition, overexpression of LINC01021 promoted growth and EMT, inhibited P53 expression and increased Bcl-2 expression in gastric cancer cells. Finally, overexpression of LINC01021 reversed the anti-cancer effect of Da0324. Our findings indicate a novel anti-cancer mechanism for Da0324, and that LINC01021 might be a potential therapeutic target for the treatment of gastric cancer.

A novel Sr2MgB2O6 (SMBO) green-emitting phosphor co-doped with Ce3+–Tb3+ was synthesized at 950 °C via solid-state reactions, and the ultra-narrow-band green emission of Tb3+ was significantly enhanced almost 20 times via energy transfer from Ce3+ to Tb3+. It was found to have a broad excitation band (250 to 400 nm), and the full width at half-maximum (FWHM) of the dominant green emission band around 544 nm was only about 10 nm. The electronic band gap of the SMBO matrix was calculated by density functional theory (DFT) to be 4.60 eV, and this was well verified by the diffuse reflection spectra results. Furthermore, the composition-optimized phosphor SMBO:0.05Ce3+,0.05Tb3+ exhibits excellent thermal quenching resistance (75.3% intensity at 423 K) and relatively high external quantum efficiency (EQE = 48.92%). Finally, two white light-emitting diode (WLED) packages were fabricated via combining a 365 nm n-UV chip, the optimal sample and commercial blue and red phosphors to assess the application potential of the phosphors. The test results indicate that the obtained WLEDs-1 fabricated with K2SiF6:Mn4+ has an outstanding color rendering index (Ra = 85.7) and Commission Internationale de L'Eclairage (CIE) coordinates (0.3242, 0.3334). Meanwhile, the color gamut can reach 87% of the National Television Standards Committee (NTSC) CIE 1931 color gamut. WLEDs-2 fabricated with red emitting CaAlSiN3:Eu2+ produced warm white light with color coordinates of (0.3792, 0.3810), a high color rendering index of 82.3, and a low correlated color temperature of 4065 K. These results reveal the broad prospects of this phosphor for LED-based applications.

Pyrolysis of waste tire is attracting widespread interest recently because of the great potential in waste valorization treatment. In this study, the thermal decomposition behavior, pyrolysis mechanism and products distribution of waste bicycle tire were investigated by means of TG-FTIR and Py-GC/MS. According to the TG results, two main pyrolysis stages of waste bicycle tire were observed, which were considered as the decomposition of rubber (285–531 °C) and further pyrolysis of pyrolytic products (663–847 °C), respectively. The volatiles release characteristics and FTIR spectrum at different temperatures exhibited good consistency with pyrolysis behavior. A detail information of pyrolysis products was analyzed by Py-GC/MS, which mainly include gaseous, alkenes and aromatics. The pyrolysis mechanism of waste bicycle tire was belong to free radical reaction, and the possible further pyrolysis pathway of D-limonene and styrene was also presented. Moreover, the products distribution under different pyrolysis final temperatures and heating rates conditions were summarized. Thus, this study could enhance our understanding on more specific details for the pyrolysis process of waste tire to some extent.

Municipal solid waste treatment has been and will continue to be a major issue facing countries worldwide, and gasification has recently gained more attention as an efficient and clean technology. The steam gasification characteristics and kinetics of five different municipal solid waste chars had been investigated by the method of isothermal thermogravimetric analysis. The results showed that the gasification reactivity increased with gasification temperature. Effect of H/C and O/C ratios, ash composition and particle pore structure of chars on gasification reactivity were studied, which illustrated that the H/C and O/C ratios and ash composition had great influence on gasification reactivity and the pore structure cannot explain well in this study. A homogeneous model, unreacted shrinking core model and random pore model were employed to describe the kinetic behavior of different chars, and the kinetic parameters were also obtained. Finally, through the evaluation of the three kinetic models by comparing the experimental data with the fitted results, the random pore model was determined to perform best. This study should, therefore, be of some value to solid waste gasification industrialization.

Recently, the renewed interest in the pyrolysis of municipal solid waste has been aroused. In this investigation, the pyrolysis behaviors and kinetics of typical municipal solid waste components an...

Pyrolysis of plastics has gained more attention recently due to the advantages of environmental protection and energy conversion. In this study, low-density polyethylene (LDPE), polypropylene (PP) and polyvinyl chloride (PVC) were studied under high heating rate conditions to investigate pyrolysis behaviors and find the most suitable kinetic reaction mechanisms. The TG and DTG curves for LDPE were similar to those for PP, but different from those for PVC. It was found that high heating rate led to the shifting of initial, end and peak temperatures to higher values. The FTIR results showed the main products of LDPE and PP were alkanes and alkenes, and the major products of PVC were HCl, alkenes and a small number of aromatic compounds. A comparative study of model-free methods like Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS) and Friedman method were discussed to calculate activation energy. Kinetic reaction mechanisms were predicted by using model-fitting methods including Coats-Redfern and Criado method. The pyrolysis reaction mechanism of LDPE was summarized as contracting sphere model, PP was summarized as contracting cylinder model, whereas that of PVC was concluded that two-dimension nucleation for the first stage and three-dimension diffusion (Jander) for the second stage.