Pyrolysis characteristics of waste tire particles in fixed-bed reactor with internals

This study investigated the characteristics of pyrolysis for waste tire particles in the newly developed fixed-bed reactor with internals that are a central gas collection channel mounted inside reactor. And a few metallic plates vertically welded on the internal wall of the reactors and extending to the region closing their central gas collection pipe walls. Experiments were conducted in two laboratory fixed bed reactors with or without the internals. The results shown that employing internals produced more light oil at externally heating temperatures above 700 °C due to the inhibited secondary reactions in the reactor. The oil from the reactor with internals contained more aliphatic hydrocarbons and fewer aromatic hydrocarbons, leading to its higher H/C atomic ratios as for crude petroleum oil. The char yield was relatively stable for two beds and showed the higher heating values (HHVs) of about 23 MJ/kg. The gaseous product of pyrolysis mainly consisted of H2 and CH4, but the use of internals led to less pyrolysis gas through its promotion of oil production. Keywords: Pyrolysis, Waste tire, Fixed bed, Internals, Secondary reaction

Assessment of char property on tar catalytic reforming in a fluidized bed reactor for adopting a two-stage gasification process

To well understand the effect of char property on tar catalytic reforming and support the development of two stage gasification technology for the clean fuel gas production, the roles of pore structure and metal oxide in tar removal behavior were examined and compared on a fluidized bed two-stage reactor. The results show that although both of micro pore and meso pore had a remarkable influence on tar removal efficiency, fuel gas component and distilling fractions in tar, perhaps micro pore played a much more important role. Moreover, the tar removal efficiency did not have a good proportional relationship with the specific surface area of char. For the spent char, the activation treatment in steam was very beneficial to renew the catalytic reforming on tar by increasing the surface area of micro pore and maintain its high gasification activity. Compared to the demineralized char, the char samples that loaded metal oxide by impregnation approach largely promoted the tar removal efficiency, following the rank of Na2O > Fe2O3 > CaO > MgO. For Na2O, it not only had the best catalytic activity on tar, but also greatly promoted the generations of light tar and effective fuel gas, such as H-2 and CO. Finally, considering the different effect of pore structure and metal oxide on tar catalytic reforming, a brief mechanism of tar catalytic reforming by char was proposed

Correlating micro/meso pore evolution and chemical structure variation in a mild thermal treatment of a subbituminite

This work investigates the evolution of micro/meso pores during a mild thermal treatment of subbituminous coal based on the observation of coal structure changes with the gradual detachment of organic matter from the coal. Pores in coal can be described as super-micropores (d < 1 nm), micropores (1 nm < d < 2 nm) and mesopores (2 nm < d < 50 nm). The decomposition of the carboxyl group at 200 degrees C decreases the super-micropore volume. A mild and sustained reaction takes place at 300 degrees C to gradually change the aromaticity and CH2/CH3 ratio of the treated coal. The amount of micropore structure sharply decreases in the early stages of heating, while the amount of mesopore structure continuously decreases during the whole process. A dramatic reaction takes place at 400 degrees C to sharply change the aromaticity and CH2/CH3 ratio of the treated coal, while the detachment of volatile compounds from the coal matrix caused an evident variation in the mesopore structure of the coal. The aromaticity and CH2/CH3 ratio of coal organics are found to correlate with the volumes of super-micropores and mesopores, respectively. The super-micropores are identified as comprising the inter-layer distance between stacks of aromatic rings, and mesopores are the spaces between macromolecular aromatic rings which are inter-connected via aliphatic chains

Optimal combination of potassium coupled with water and nitrogen for strawberry quality based on consumer-orientation

The quality of strawberry fruits is a key factor in consumer choice. This study investigated the effect of potassium coupled with water and nitrogen on multiple strawberry fruits quality categories over two growing seasons (from August 2021 to April 2022 and August 2022 to April 2023) in China, to aid in the determination of water and fertilizer decisions based on consumer-orientation. In particular, a composite quadratic orthogonal rotation design with three factors and five levels was adopted to characterize volume water content (W), nitrogen (N) and potassium (K). Twelve quality indicators at three harvest stages were measured respectively. The indicators related to commodity quality, flavor quality and nutritional quality of strawberry fruits were assigned weights based on consumer orientation using analytic hierarchy process. Total soluble solid was regarded as the most important quality indicator with the weight value of 0.1387, followed by single fruit weight (0.1183). All the quality indicators of strawberry fruits were systematically evaluated based on grey relational analysis, and the response model of the comprehensive quality to the combined application of W, N and K was established for each harvest stages. The response trends of consumer-oriented quality were shown as negative parabolas basically to W, N and K in all the three harvests, except a negative linear trend to W in the third harvest and an increased linear to K in the second harvest. Notably, the low level of K supply limited the quality of strawberries, regardless of the input amount of W and N. And the coded values of the optimal combinations for W, N and K were (−0.728, 0, 0.512), (−0.440, 0, 1.682) and (−1.682, 0, 0.834) for the three harvest stages, respectively. By weighting the comprehensive quality based on the corresponding yield of strawberry for the three harvest stages over the two study seasons, the optimal application interval of W, N and K for the entire growth period was determined as: 55.05–76.45%, 3.32 – 4.49 g N/plant and 4.06 – 5.47 g K2O/plant, respectively. The results of this experiment provide a theoretical basis for water and fertilizer management, as well as the in-depth research of strawberry

Three Dimensional Volumetric Analysis of Solid Pulmonary Nodules on Chest CT: Cancer Risk Assessment

Background and objective The management of pulmonary nodules relies on cancer risk assessment, in which the only widely accepted criterion is diameter. The development of volumetric computed tomography (CT) and three-dimensional (3D) software enhances the clarity in displaying the nodules’ characteristics. This study evaluated the values of the nodules’ volume and 3D morphological characteristics (edge, shape and location) in cancer risk assessment. Methods The CT data of 200 pulmonary nodules were retrospectively evaluated using 3D volumetric software. The malignancy or benignity of all the nodules was confirmed by pathology, histology or follow up (>2 years). Logistic regression analysis was performed to calculate the odds ratios (ORs) of the 3D margin (smooth, lobulated or spiculated/irregular), shape (spherical or non-spherical), location (purely intraparenchymal, juxtavascular or pleural-attached), and nodule volume in cancer risk assessment for total and sub-centimeter nodules. The receiver operating characteristic (ROC) curve was employed to determine the optimal threshold for the nodule volume. Results Out of 200 pulmonary nodules, 78 were malignant, whereas 122 were benign. The Logistic regression analysis showed that the volume (OR=3.3; P0.05). ROC analysis showed that the optimal threshold for malignancy was 666 mm³. For sub-centimeter nodules, the 3D margin was the only valuable predictive factor of malignancy (OR=60.5, 75.0; P=0.003, 0.007). Conclusion The volume and 3D margin are important factors considered to assess the cancer risk of pulmonary nodules. Volumes larger than 666 mm³ can be determined as high risk for pulmonary nodules; by contrast, nodules with lobulated, spiculated, or irregular margin present a high malignancy probability

Analysis of Growth Curve Type in Pulmonary Nodules with Different Characteristics

Background and objective Background and objective Follow up by computed tomography (CT) and growth evaluation are routine methods for the differential diagnosis of indeterminate pulmonary nodules in clinical practice. Pulmonary nodules with diverse biological behaviors may show different growth patterns and velocities. The aim of this study is to identify the volume growth curve of both benign and malignant pulmonary nodules. This work also intends to determine these nodules’ growth patterns and provide evidence for the establishment of a follow-up strategy. Methods The CT data of 111 pulmonary nodules (54 solid, 57 subsolid) were retrospectively evaluated using 3D volumetric software. All of these nodules have been followed up at least twice. Of these nodules, 35 were confirmed as lung cancers, whereas 5 were confirmed as benign by pathology or histology. Moreover, 71 nodules showed no growth in more than 2 years. Stable nodules were defined as low-risk nodules, as confirmed by reevaluation from experts. On the basis of their densities and diameters, the nodules were classified into four types: benign/low-risk solid nodules, malignant solid nodules (diameter ≤1 cm and >1 cm), benign/low-risk subsolid nodules, and malignant subsolid nodules (diameter ≤1 cm and >1 cm). The follow-up interval time (d) were plotted on the x-axis, and the nodules’ volume (mm3) and logarithmic volume were plotted on the y-axis. Two radiologists subjectively determined the type of growth curve. Chi-square test was performed to compare the growth curves of benign/low-risk and malignant nodules. Results Of 18 solid cancers, 12 cases (66%) were found with steep ascendant growth curves. Those of 3 cases (16.7%) were flat ascendant, 2 cases (11.1%) slowly ascendant, and 1 (5.56%) case flat. Of 17 subsolid cancers, 8 cases (47.1%) manifested steep ascendant growth curves. Those of 4 cases (23.5%) were slowly ascendant, 3 (17.6%) flat, and 2 (11.8%) descendant–ascendant. Of 36 benign/low-risk solid nodules, 5 cases (13.9%) manifested descendant growth curves, 17 cases (47.2%) flat, 8 cases (21.6%) slowly ascendant, and 6 cases (16.7%) undulate. Of 40 benign/low-risk subsolid nodules, 4 cases (10%) manifested descendant growth curves, 21 cases (52.5%) flat, 9 cases (22.5%) slowly ascendant, and 6 cases (15%) undulate. The distribution of growth curve types significantly differed between benign/low-risk and malignant nodules (χ2=42.4, P<0.01). Conclusion The growth curves of lung cancers are heterogeneous. A steep ascendant curve is the main type for lung cancer, with the exception of flat, slowly ascendant, or even descendant curve. A slowly ascendant curve cannot exclude the diagnosis of lung cancer, especially for subsolid nodules

Quick pyrolysis of a massive coal sample via rapid infrared heating

There are few studies about pyrolysis with the a massive sample at high heating rates to obtain liquid and gas products. This study adopted a newly designed small fixed bed reactor mounted with infrared heating to minimize secondary reactions to volatiles and further to investigate the pyrolysis of Xinjiang Naomaohu coal in terms of pyrolysis products characterization at different temperatures and heating rates. Infrared heating has good penetrability to heat the inner layer of the sample at a quick rate of up to 1723 degrees C/min in the particle bed. For the tested reactor at 700 degrees C, raising the heating rate decreased the yields of gas and char and increased the yield of tar. The realized tar yield was higher than that in Gray-King (G-K) assay at heating rates above 18 degrees C/min. For the heating rate of 667 degrees C/min at the pyrolysis temperature of 700 degrees C, the obtained maximum yield of tar was 134% of the G-K assay oil yield. Overall, increasing the heating rate decreased char yield and increased the production of total volatiles. At higher heating rates, the tar became heavier, while at higher pyrolysis temperatures, it produced more light tar. The extraction rate of hydrogen from coal was found to be subject to a linear relationship with pyrolysis gas yield

PHYTOCHROME-INTERACTING FACTORS Interact with the ABA Receptors PYL8 and PYL9 to Orchestrate ABA Signaling in Darkness

PHYTOCHROME-INTERACTING FACTORS (PIFs) are a group of basic helix-loop-helix transcription factors that can physically interact with photoreceptors, including phytochromes and cryptochromes. It was previously demonstrated that PIFs accumulated in darkness and repressed seedling photomorphogenesis, and that PIFs linked different photosensory and hormonal pathways to control plant growth and development. In this study, we show that PIFs positively regulate the ABA signaling pathway during the seedling stage specifically in darkness. We found that PIFs positively regulate ABI5 transcript and protein levels in darkness in response to exogenous ABA treatment by binding directly to the G-box motifs in the ABI5 promoter. Consistently, PIFs and the G-box motifs in theABI5 promoter determineABI5 expression in darkness, and overexpression of ABI5 could rescue the ABA-insensitive phenotypes of pifq mutants in the dark. Moreover, we discovered that PIFs can physically interact with the ABA receptors PYL8 and PYL9, and that this interaction is not regulated by ABA. Further analyses showed that PYL8 and PYL9 promote PIF4 protein accumulation in the dark and enhance PIF4 binding to the ABI5 promoter, but negatively regulate PIF4-mediated ABI5 activation. Taken together, our data demonstrate that PIFs interact with ABA receptors to orchestrate ABA signaling in darkness by controlling ABI5 expression, providing new insights into the pivotal roles of PIFs as signal integrators in regulating plant growth and development