Co-pyrolysis of sewage sludge and waste tobacco stem: Gas products analysis, pyrolysis kinetics, artificial neural network modeling, and synergistic effects.

This research comprehensively investigates the co-pyrolysis of sewage sludge (SS) and waste tobacco stem (WTS). Various SS and WTS ratios (1:0, 0.75:0.25, 0.50:0.50, 0.25:0.75, and 0:1) were tested over a range of heating rates (30 °C to 800 °C). Apparent activation energies were calculated using model-free methods, and the co-pyrolysis mechanism was described with the master plot method. Results suggest that SS and WTS co-pyrolysis follows power-law models (P3, P4). Among blends, S75W25 exhibited optimal synergy, with the lowest activation energy required for the pyrolysis reactions and inhibits CO2 emissions. S75W25's pyrolysis gas primarily contained acids (e.g., ethylxanthogenacetic acid, acetic acid), hydrocarbons (e.g., supraene, cyclopropyl carbinol), and other compounds (e.g., CO2, pyrazine, pyridine, indole). ANN was utilized to forecast the temperature-mass loss relationships in co-pyrolysis, with the optimal model being ANN21, yielding a high correlation coefficient (R2 = 0.99999). This study offers guidance for the efficient utilization of waste SS and WTS.

Spatial heterogeneity analysis of matching degree between endangered plant diversity and ecosystem services in Xishuangbanna.

Biodiversity and ecosystem services (ESs) are closely linked. Human activities have caused critical damage to the habitat and ecosystem function of organisms, leading to decline in global biodiversity and ecosystem services. To ensure sustainable development of local ecological environments, it is critical to analyze the spatial matching degree of biodiversity and ESs and identify ecologically vulnerable areas. Taking Xishuangbanna, southern China, as an example, we constructed a pixel-scale matching degree index to analyze the spatial matching degree of endangered plant diversity (EPD) and four ESs and classified the matching degree into low-low, low-high, high-low, and high-high four types. The results revealed a mismatch relationship of EPD and ESs in more than 70% of areas. Under the influence of altitude and land use/land cover (LULC) type, the matching degree of EPD and ESs showed obvious spatial heterogeneity. In low-altitude areas in the south of Xishuangbanna, EPD and ESs mainly showed mismatch, while high-altitude areas in the west had a better match. Natural forest was the main land cover in which EPD and ESs showed high-high match and its areal proportion was much larger than that of rubber plantation, tea plantation, and cropland. Our findings also stress the need to concentrate conservation efforts on areas exhibiting a low-low match relationship, indicative of potential ecological vulnerability. The pixel-scale spatial matching degree analysis framework developed in this study for EPD and ESs provides high-resolution maps with 30 m × 30 m pixel size, which can support the implementation of ecological protection measures and policy formulation, and has a wide range of applicability. This study provides valuable insights for the sustainable management of biodiversity and ESs, contributing to the strengthening of local ecological environment protection.

Towards sustainable management of agricultural resources: A framework to assess the relationship between water, soil, economic factors, and grain production.

As the requirements for environmental protection and high-efficiency economies increase, grain production (GP) across the globe faces more stringent ecological constraints and economic pressure. Understanding the relationships between natural resources and economic and agricultural factors in grain-producing regions is paramount for ensuring global food security. This paper proposes a methodological framework to explore the relationships between water and soil resources (WSRs), economic input factors (EIFs), and GP. We employed the northeast region of China as a case study to advance our understanding of the factors driving the development of grain-producing capacity. We first constructed and calculated the region's water and soil comprehensive index (WSCI) to describe water-soil properties. We then used hotspot analysis to explore the spatial agglomeration characteristics of WSRs, EIFs, and GP. Finally, we used threshold regression analysis to understand the effects of EIFs and GP with the WSCI as the threshold variable. With the improvement of the WSCI, the positive impact of fertilizer and irrigation on GP shows a U-shaped curve in elasticity coefficients. The positive effect of agricultural machinery on GP decreases significantly, and the impact of labor input on GP is insignificant. These results provide new insights into the relationship between WSRs, EIFs, and GP and a reference for improving GP efficiency globally. This work thus contributes to advancing our capabilities to enable food security while considering aspects of sustainable agriculture in important grain-producing regions across the globe.

Impacts of environment and human activity on grid-scale land cropping suitability and optimization of planting structure, measured based on the MaxEnt model.

Making full use of agricultural resource endowment, determining the planting suitability of areas for different crops according to the environment and human activities, and optimizing planting structure are important ways to ensure stable increases in crop yield and improve food production capacity. Taking Songhua River Basin (SRB) as an example, this study used geographic distribution information on different crops and the Maximum Entropy (MaxEnt) model to determine the degree of suitability of land in SRB for cropping, and to optimize the layout of crop planting structure. The results showed that the main factors affecting land suitability for different crops, with a combined contribution >80%, were population density, Distance from road to cultivated land, normalized difference vegetation index, and total phosphorus. Under the joint influence of the environment and human activity, the total unsuitable area of the four crops became much more extensive, with the unsuitable area of soybean being the largest (173 thousand km2) and the smallest for wheat (128 thousand km2). The highly suitable area was largest for wheat (2 thousand km2), while the other three crops were less than 2 thousand km2. Suitable distribution areas for all four crops were mainly located in the center of the basin (Songnen Plain) and in a wedge in the northeast corner (Sanjiang Plain). The relationships between different crops and environment and human activities revealed that crop suitability distribution is mainly determined by human activities, rather than the environment. These results provide a scientific basis for optimizing crop layout and improving the planting system, ensuring the security of food production.

Impacts of land use/land cover changes on ecosystem services in ecologically fragile regions.

High-density human activities have rapidly changed the pattern of urban land use/land cover (LULC), affecting the supply of urban ecosystem services (ESs). This poses a challenge to the balance of urban development and ecological protection, which may be more serious in ecologically fragile regions. This study identified key LULC change (LULCC) impacts on ESs in Ordos, an ecologically fragile region in Northwest China. The urbanization process of Ordos will continue in 2030 under the business-as-usual scenario due to its strategic positioning in the National Energy Base of China. The future LULC simulation results showed that developed land in eastern Ordos will continue to expand in 2030, and more forest and grassland will appear in western Ordos as a result of ecological restoration. The results of the InVEST model in calculating four important ESs showed that the ES supply in the densely populated areas (eastern Ordos) has declined, and more attention must be given to natural vegetation protection in the urbanization process. Although carbon storage in the western region has increased due to afforestation, this also reduces the water yield supply, which may exacerbate the water shortage in Ordos. Supported by this framework, more sustainable urban land use management can be undertaken to balance the conflict between ecological protection and urbanization. This will contribute to regional ecological health and sustainable urban development.

Impact and trade off analysis of land use change on spatial pattern of ecosystem services in Chishui River Basin.

The motivation of this fundamental research is to reveal the response of ecosystem services to land use change and to support the sustainable development of ecology, economy, and society. Considering the fragile eco-environment, intensive man-land relationship and the world-famous production base of Moutai liquor in China, we select Chishui River Basin (CRB) as the research region. In this study, the InVEST model is used to evaluate the impact of land use change on the spatial pattern of four ecosystem services including water yield, soil retention, carbon storage, and nitrogen export. Meanwhile, the spatial differentiation characteristics, service level, and trade-off using Pearson correlation analysis of each ecosystem service from 2000 to 2020 are explored. The results show the following: (1) The forest increased, while the grassland and cultivated decreased. Especially, the developed has increased greatly from [Formula: see text] to [Formula: see text]. (2) Each ecosystem service has spatio-temporal heterogeneity. The water yield and nitrogen export decreased, while soil retention and carbon storage showed an upward trend. (3) There are great differences in the level of ecosystem services among different land use types. The soil retention and carbon storage of forest are the highest, and the water yield of developed is the highest. (4) There are trade-offs and synergies among ecosystem services, such as the trade-off between water yield and soil retention is increasing, the synergetic relationship between water yield and nitrogen export is decreased. This is important evidence that the forest plays a major role in providing ecosystem services, and the improvement of watershed ecological services generally benefits from the implementation of ecological governance projects in recent years. However, it is worth noting that the frequent changes in land use and the intensification of urbanization have also brought potential risks to the local ecology. Therefore, all our preliminary results throw light on the nature of the impact of land use change on ecology and the trade-off relationship of ecosystem services, which is conducive to scientific protection of watershed ecological environment and the formulation of reasonable land use planning policies.

Investigation of non-isothermal pyrolysis kinetics of waste industrial hemp stem by three-parallel-reaction model.

The evaluation of pyrolysis kinetics for waste industrial hemp stem (IHS) is essential to achieve the high-value utilization of agricultural waste. In present study, firstly, non-isothermal pyrolysis experiments of IHS were performed at different heating rates using a thermogravimetric analyzer. Then, the kinetic triplets (apparent activation energy, pre-exponential factor, and reaction mechanism) of the three pseudo components for IHS (hemicellulose, cellulose, and lignin) were determined by a three-parallel-reaction model. Moreover, the pyrolysis products were also characterized via FTIR and SEM. The results showed that the apparent activation energies of hemicellulose, cellulose and lignin were 86.523, 113.257 and 197.961 kJ/mol, respectively; the pre-exponential factors were 6.887 × 107, 8.179 × 109 and 1.801 × 1015 s-1, respectively; and the reaction mechanism functions were f(α) = α1.35629(1-α)0.34832[-ln(1-α)]-1.20128, f(α) = α3.42900(1-α)0.01288[-ln(1-α)]-2.84445, f(α) = α0.68738(1-α)3.09313[-ln(1-α)]-1.58522, respectively. The release temperature for volatile products of IHS pyrolysis was mainly between 440 and 840 K. IHS as an agricultural waste is a suitable feedstock to produce renewable energy.

Mental health is correlated with lipoprotein(a) levels in male patients with premature coronary heart disease.

BACKGROUND: High levels of lipoprotein(a) (Lp(a)) is an independent risk factor for premature coronary heart disease (PCHD). It is also considered a residual risk for controlled low density lipoprotein cholesterol (LDL-C). Dietary control, exercise, and drugs have limited effects on the levels of Lp(a). Recently, mental health was found to be associated with lipid levels and increased risk of PCHD. However, the relationship between mental health and Lp(a) is still unknown. This study explored the association between mental health and Lp(a) levels in men with PCHD. METHODS: A retrospective, observational study was conducted. A total of 226 male patients with PCHD, aged 49.65±3.68 years, was included in this study. The control group consisted of 230 age-matched healthy male volunteers. Serum Lp(a) levels ≥30 mg/dL, as measured by the immunoturbidimetry method, were considered high. All participants received health related quality of life (HRQoL) scores using the self-assessed 36-Item Short Form Health Survey (SF-36). The HRQoL includes both a physical component summary (PCS) and a mental component summary (MCS). RESULTS: Patients with PCHD were found to have higher levels of Lp(a) (51.61±33.39 vs. 26.42±21.93, P<0.001), and lower MCS (35.83±4.21 vs. 39.85±4.12) and PCS scores (38.02±3.73 vs. 39.63±3.21) compared to healthy volunteers. The MCS score was negatively correlated with Lp(a) levels in the PCHD group (R=-0.295, P<0.001), but no correlation was detected in the control group. There was no relationship between the PCS score and Lp(a) levels in neither the PCHD group nor the healthy control group. Multivariate logistic regression analysis indicated that the MCS and PCS scores were negatively correlated with the risk of PCHD. CONCLUSIONS: These findings suggested that poor mental health may be associated with high levels of Lp(a) and increased risk of PCHD in men. Therefore, improving the mental state in men with PCHD may be crucial.

Shape Effect of the Riser Cross Section on the Full-Loop Hydrodynamics of a Three-Dimensional Circulating Fluidized Bed.

In this work, numerical simulation is carried out in a three-dimensional full-loop pilot-scale circulating fluidized bed to explore the shape effect of the riser cross section on the typical flow characteristics of the bed via the multiphase particle-in-cell (MP-PIC) method. The gas and solid phases are modeled with the large eddy simulation and Newton's law of motion in the Eulerian and Lagrangian frameworks, respectively. The proposed model has been well validated with experimental data, followed by evaluating the typical core-annulus structure and the nonuniformity of the solid phase distributed along the radial and axial directions of the riser. Then, the particle-scale information of the solid phase distributed in different parts of the system is explored. The results demonstrate that (i) the square riser gives rise to a higher solid inventory in the standpipe owing to the stronger circulation intensity; (ii) the thickness of the solid back-mixing layer reduces along the riser height; the solid back-mixing tends to concentrate in the four corners, while it is not obvious near the sidewalls of the square riser; and (iii) nonuniform distribution of the particle-scale information of the solid phase (e.g., mass, flux, drag force, and slip velocity) can be observed. The square riser gives rise to comparatively more uniform axial mass distribution, a larger rising solid flux, larger horizontal transportation velocity between the core and annulus regions, and a larger horizontal dispersion coefficient in the riser, as compared with the corresponding ones in the circular riser.

Consistent second-order boundary implementations for convection-diffusion lattice Boltzmann method.

In this study, an alternative second-order boundary scheme is proposed under the framework of the convection-diffusion lattice Boltzmann (LB) method for both straight and curved geometries. With the proposed scheme, boundary implementations are developed for the Dirichlet, Neumann and linear Robin conditions in a consistent way. The Chapman-Enskog analysis and the Hermite polynomial expansion technique are first applied to derive the explicit expression for the general distribution function with second-order accuracy. Then, the macroscopic variables involved in the expression for the distribution function is determined by the prescribed macroscopic constraints and the known distribution functions after streaming [see the paragraph after Eq. (29) for the discussions of the "streaming step" in LB method]. After that, the unknown distribution functions are obtained from the derived macroscopic information at the boundary nodes. For straight boundaries, boundary nodes are directly placed at the physical boundary surface, and the present scheme is applied directly. When extending the present scheme to curved geometries, a local curvilinear coordinate system and first-order Taylor expansion are introduced to relate the macroscopic variables at the boundary nodes to the physical constraints at the curved boundary surface. In essence, the unknown distribution functions at the boundary node are derived from the known distribution functions at the same node in accordance with the macroscopic boundary conditions at the surface. Therefore, the advantages of the present boundary implementations are (i) the locality, i.e., no information from neighboring fluid nodes is required; (ii) the consistency, i.e., the physical boundary constraints are directly applied when determining the macroscopic variables at the boundary nodes, thus the three kinds of conditions are realized in a consistent way. It should be noted that the present focus is on two-dimensional cases, and theoretical derivations as well as the numerical validations are performed in the framework of the two-dimensional five-velocity lattice model.

Forcing scheme analysis for the axisymmetric lattice Boltzmann method under incompressible limit.

Because the standard lattice Boltzmann (LB) method is proposed for Cartesian Navier-Stokes (NS) equations, additional source terms are necessary in the axisymmetric LB method for representing the axisymmetric effects. Therefore, the accuracy and applicability of the axisymmetric LB models depend on the forcing schemes adopted for discretization of the source terms. In this study, three forcing schemes, namely, the trapezium rule based scheme, the direct forcing scheme, and the semi-implicit centered scheme, are analyzed theoretically by investigating their derived macroscopic equations in the diffusive scale. Particularly, the finite difference interpretation of the standard LB method is extended to the LB equations with source terms, and then the accuracy of different forcing schemes is evaluated for the axisymmetric LB method. Theoretical analysis indicates that the discrete lattice effects arising from the direct forcing scheme are part of the truncation error terms and thus would not affect the overall accuracy of the standard LB method with general force term (i.e., only the source terms in the momentum equation are considered), but lead to incorrect macroscopic equations for the axisymmetric LB models. On the other hand, the trapezium rule based scheme and the semi-implicit centered scheme both have the advantage of avoiding the discrete lattice effects and recovering the correct macroscopic equations. Numerical tests applied for validating the theoretical analysis show that both the numerical stability and the accuracy of the axisymmetric LB simulations are affected by the direct forcing scheme, which indicate that forcing schemes free of the discrete lattice effects are necessary for the axisymmetric LB method.

Alternative extrapolation-based symmetry boundary implementations for the axisymmetric lattice Boltzmann method.

In this study, alternative symmetry boundary implementations for the axisymmetric lattice Boltzmann (LB) method are proposed based on the nonequilibrium extrapolation and the direct extrapolation schemes. The proposed boundary schemes are directly implemented on the symmetry axis, and the postcollision distribution function and the macroscopic variables at the boundary nodes are extrapolated from the inner fluid nodes; thereby, the singularities arising at the symmetry axis (r=0) during the collision and the macroscopic variable calculations are completely avoided. The accuracy of the present schemes is consistent with the well-established axisymmetric LB model. Moreover, in comparison with previous symmetry boundary schemes, the present implementations are slightly more accurate than the symmetry scheme by Guo et al. [Phys. Rev. E 79, 046708 (2009)10.1103/PhysRevE.79.046708] and numerically more stable than the specular reflection-based schemes.

Consistent lattice Boltzmann methods for incompressible axisymmetric flows.

In this work, consistent lattice Boltzmann (LB) methods for incompressible axisymmetric flows are developed based on two efficient axisymmetric LB models available in the literature. In accord with their respective original models, the proposed axisymmetric models evolve within the framework of the standard LB method and the source terms contain no gradient calculations. Moreover, the incompressibility conditions are realized with the Hermite expansion, thus the compressibility errors arising in the existing models are expected to be reduced by the proposed incompressible models. In addition, an extra relaxation parameter is added to the Bhatnagar-Gross-Krook collision operator to suppress the effect of the ghost variable and thus the numerical stability of the present models is significantly improved. Theoretical analyses, based on the Chapman-Enskog expansion and the equivalent moment system, are performed to derive the macroscopic equations from the LB models and the resulting truncation terms (i.e., the compressibility errors) are investigated. In addition, numerical validations are carried out based on four well-acknowledged benchmark tests and the accuracy and applicability of the proposed incompressible axisymmetric LB models are verified.

Clopidogrel and Aspirin versus Aspirin Alone for Stroke Prevention: A Meta-Analysis.

BACKGROUND AND PURPOSE: Antiplatelet therapy is widely used for the primary or secondary prevention of stroke. Drugs like clopidogrel have emerged as alternatives for traditional antiplatelet therapy, and dual therapy with clopidogrel and aspirin is of particular interest. We conducted this meta-analysis to systematically review studies about dual therapy comparing monotherapy with aspirin alone. METHODS: Randomized controlled trials were searched in PubMed (1966-May, 2015), EMBASE (1947-May, 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (1948-May, 2015), WHO International Clinical Trial (ICTRP) (2004-May, 2015), China Biology Medicine disc (CBM disc) (1978-May, 2015) and were included into the final analysis according to the definite inclusion criteria mentioned in the study selection section. Risk ratio (RR) was pooled with 95% confidence interval (CI) for dichotomous data. The heterogeneity was considered significant if the χ2 test was significant (P value < 0.10) or the I2 > 50.00%. Subgroup analyses were carried out on the long and short time periods, the race and region. RESULTS: We included 5 studies involving 24,084 patients. A pooled analysis showed that dual therapy with clopidogrel and aspirin had a lower stroke incidence than monotherapy in both the short term and long term (RR = 0.69, 95% CI: 0.59-0.82, P <0.05; RR = 0.84, 95% CI: 0.72-0.98, P = 0.03, respectively). With regard to safety, dual therapy had a higher risk of bleeding than monotherapy for both periods (RR = 1.51, 95% CI: 1.03-2.23, P = 0.04; RR = 1.54, 95% CI: 1.32-1.79, P<0.05, respectively). CONCLUSIONS: Dual therapy with clopidogrel and aspirin could be a preferable choice to prevent stroke in patients who have had a previous stroke or transient ischemic attack, as well as those who are at high risk for stroke. And the effect of dual therapy seems to be more obvious for short-term. However, it is associated with a higher risk of bleeding.

WITHDRAWN: Effects of atorvastatin treatment and withdrawal on blood brain barrier in focal cerebral ischemia-reperfusion injury.

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