Hasil untuk "Chemical engineering"

Menampilkan 20 dari ~14799058 hasil · dari DOAJ, Semantic Scholar, CrossRef

JSON API
DOAJ Open Access 2026
Innovative pathways for detonation power generation technology in deep coal fluidization development

Shirong GE, Jing GUO

Deep coal resources with abundant reserves and considerable thermal potential are receiving increased attention in mining engineering, given the accelerating transformation of the global energy structure and the growing demand for clean energy. To address extraction challenges and environmental pressures while ensuring economic feasibility and sustainable development, efforts are made to enable carbon reduction and green transformation under high-efficiency utilization of deep coal resources. A systematic review of “deep coal resource fluidized mining”, “coal chemical mining”, and “coal-based power” informs the introduction of a detonation-generation mining approach and its technical framework. The approach places coal-powder detonation combustion technology at its core and integrates advanced detonation combustion-mechanical/magnetohydrodynamic power generation, forming a detonation-turbine/MHD hybrid power system that supports efficient conversion and clean utilization of coal resources. Four fundamental theories are presented, including the Coal-powder Detonation Energy Release mechanism, the Coupled Coal-powder Detonation-generation Power Scheme, a Full Life Cycle Detonation-power Generation Dynamic Management Mechanism, and the Blasting-electric Power Deep coal mining theory and method. Discussion centers on four key technologies: Stable coal/gas two-phase detonation, detonation model construction and dynamic process optimization, detonation-based power generation efficiency assessment, and comprehensive design for detonation-based coal mining, demonstrating their role in upgrading deep coal mining practices. On this foundation, a systematic engineering strategy is proposed to clarify the synergy between mining processes and the detonation-based power generation mode, highlight safety management and process optimization priorities at each critical stage, and refine the overall detonation-generation pathway for deep coal resource development. This pathway offers valuable insights for establishing a coal-based power system and promoting the clean and efficient utilization of deep coal resources in China.

Geology, Mining engineering. Metallurgy
DOAJ Open Access 2025
Machine Learning–Based Prediction of Organic Solar Cell Performance Using Molecular Descriptors

Mohammed Saleh Alshaikh

The performance of Organic Solar Cells (OSCs) is intrinsically linked to the molecular, electronic, and structural properties of donor and acceptor materials. This study employs various machine learning techniques, namely the Generalized Regression Neural Network (GRNN), Support Vector Machine (SVM), and Tree Boost, to predict key performance metrics of OSCs, including power conversion efficiency (PCE), short-circuit current density (JSC), open-circuit voltage (VOC), and fill factor (FF). The models are trained and evaluated using an experimentally reported dataset compiled by Sahu et al. Correlation analysis demonstrates that material characteristics such as polarizability, bandgap, dipole moment, and charge transfer are statistically associated with OSC performance. The predictive performance of the GRNN model is compared with that of the SVM and Tree Boost models, showing consistently lower prediction errors within the considered dataset. In addition, sensitivity analysis is performed to assess the relative importance of the predictor variables and to examine the influence of kernel functions on GRNN performance. The results indicate that machine learning models, particularly GRNN, can serve as effective data-driven tools for predicting the performance of organic solar cells and for supporting computational screening studies.

Transportation engineering, Systems engineering
DOAJ Open Access 2025
Ghrelin increases cis-platinum resistance and promotes aggressiveness of osteosarcoma by activating AKT and Wnt/β-catenin pathways

Menglin Cong, Shufeng Li, Yu Fu et al.

Abstract Osteosarcoma (OS) is the most common primary bone malignancy because of its extra high tendency of metastasis. In-depth research is needed to uncover the pathogenesis of patients with OS cells. We collected 74 tissue samples from patients with OS cells and measured the expression levels of ghrelin by immunohistochemistry. Ghrelin was added into OS cell lines in CCK8 assays, JC-1 staining and Western blot analysis were performed to explore its effect on the aggressiveness of OS cells and drug resistance. To determine its function, ghrelin was overexpressed or knocked down in OS cells and then detect cell proliferation in the xenograft mouse model and orthotopic model. Western blot analysis was performed to explore ghrelin-regulated signal pathways. In this work, we identified the relation between the level of ghrelin expression and poor prognosis of OS patients. As well as promoting proliferation, migration, and invation, ghrelin promotes the survival of OS in vitro as well as in vivo, and reduces the apoptosis of OS cells. What’s more, ghrelin increases the resistance of cis-platinum by changing mitochondrial function and decreases the expression of MDR-1. Above all, these results demonstrated ghrelin exerts tumorigenic and metastatic effects and may be a potential therapeutic target.

Orthopedic surgery, Diseases of the musculoskeletal system
DOAJ Open Access 2025
Thermal conductivity enhancement for multi-functional phase change materials: From random fillers to oriented networks in viscous systems

Wanwan Li, Tong Yang, Jiaxin Shi et al.

Summary: Enhancing thermal conductivity in viscous multifunctional phase change materials (MPCMs) remains a critical challenge. Conventional filler dispersion or pre-built conductive networks often fail due to poor impregnation, resulting in discontinuous pathways. Here, we present a sequential assembly strategy to reconfigure the microstructure of a high-viscosity olefin block copolymer (OBC) system, constructing a hierarchical (PA@CA)/OBC composite. This design overcomes interfacial issues, enabling complete, oriented thermal-conductive networks. The optimized composite achieves an in-plane thermal conductivity of >10 W m−1 K−1 and enhanced vertical conduction. As an anisotropic phase change thermal manager for lithium-ion batteries, it reduces the peak temperature by 16.3°C during 3C-rate discharge, while the radial conductivity increases from 5.36 to 12.64 W m−1 K−1. This work resolves the long-standing challenge of viscosity-limited thermal enhancement and provides a generalizable strategy for constructing oriented networks in high-viscosity energy materials, advancing targeted thermal management or energy storage applications.

DOAJ Open Access 2025
Y Zeolite-Based Catalyst for Palm Oil Cracking to Produce Gasoline

Arif Algifari, I. G. B. N. Makertihartha, Subagjo Subagjo et al.

The increasing demand for oil fuel and the decline of crude oil reserves highlight the need for alternative energy sources. Palm oil, as a renewable resource, has potential for biofuel production through catalytic cracking. This study aims to develop and evaluate modified zeolite-based catalysts, particularly ZSM-5/HY, to produce palm oil-derived gasoline that meets European fuel standards. The research involved catalyst preparation, modification with ZSM-5 and phosphorus, and activity testing in a fixed-bed reactor. Gasoline yield and catalyst performance were analyzed using gas chromatography. The results showed nearly 100% conversion of palm oil under optimal conditions, with gasoline yield meeting European standard. The addition of ZSM-5 improved conversion and RON, while phosphorus modification reduced catalyst acidity, affecting yield and coke formation. This study concludes that modifying zeolite catalysts with ZSM-5 and phosphorus enables efficient palm oil-derived gasoline production with high RON and reduced aromatic content, contributing to sustainable energy solutions. Copyright © 2025 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Chemical engineering
DOAJ Open Access 2025
Ligand-channel-induced ion liberation in crowded zwitterionic hydrogel electrolyte for efficient zinc metal batteries

Cheng Wang, Zhe Gong, Jodie A. Yuwono et al.

Abstract Developing efficient electrolytes is vital for realizing the vision of aqueous rechargeable zinc-metal batteries as a safe and sustainable energy storage technology. Emerging electrolyte engineering approaches including concentrated and molecular crowding electrolytes restrict water reactivity but usually incur limited bulk ionic conductivity and sluggish interfacial kinetics as well. Here we show that this dilemma can be addressed by deploying hydrogel electrolytes that incorporate typical molecular crowding electrolytes with a zwitterionic polymer matrix. This crowded zwitterionic hydrogel electrolyte counterintuitively entails Zn2+ liberation for higher ionic conductivity and prompt interfacial desolvation kinetics while maintaining essential advantages of molecular crowding electrolytes, thereby fundamentally overcoming the critical issues associated with such electrolytes. Such electrolytes enable the assembled zinc-metal batteries and zinc-ion hybrid capacitors to work effectively and stably at high rates (up to 5 A g−1) and frozen temperatures (down to −60°C). The applicability of this crowding-induced ion liberation strategy was also extended to other aqueous metal-ion (Mg2+ and Na+) batteries. This work has the potential to provide a general solution to efficient electrolytes for safer, energy-dense, and cost-effective aqueous energy storage technologies.

DOAJ Open Access 2024
Investigation of mechanical morphological structural and electrochemical properties of PVD TiAlN coating: A detail experimental and its correlation with an analytical approach using the least square method

Soham Das, Soumya Kanti Biswas, Abhishek Kundu et al.

In this experimental investigation, a Physical Vapor Deposition (PVD) process was employed to deposit TiAlN coating onto a Si substrate. The nitrogen flow rate, bias voltage, and substrate-to-target distance were selected as input parameters, each with three different levels. The design of these input parameters was structured according to Taguchi's L9 Orthogonal Array (OA). Following deposition, the mechanical, microstructural, structural, and electrochemical properties of the TiAlN coating were meticulously characterized and analyzed to discern the influence of the selected parameters on its various properties. Microstructural analysis revealed a homogeneous structure throughout the film. Additionally, the mechanical properties of the film exhibited notable performance under the specified parameters. However, it was observed that no consistent trend could be identified across different properties concerning the applied parameters. To elucidate the complex relationships among these variables, the Least Squares Method (LSM) regression analysis technique was employed. This analytical approach facilitated the establishment of correlations among the diverse parameters, enhancing the understanding of their collective impact on the TiAlN coating properties. The understanding of analytical results will be useful for predicting the values between the two extremities to measure the performance parameters where the experimental results are not available.

Materials of engineering and construction. Mechanics of materials, Industrial electrochemistry
DOAJ Open Access 2024
Alkali-impregnated blast furnace slag heterogeneous catalyst for biodiesel production

J.S. Ali, H.L. Rutto, T. Seodigeng et al.

Blast furnace slag (BFS), a waste product from the blast furnace during iron extraction, has severe environmental impacts but is also rich in compounds that, if adequately extracted or recycled, could contribute to economic growth and reduce the demand for virgin raw materials. This research, therefore, seeks to investigate the effectiveness of the BFS composition before and after impregnation with potassium hydroxide (KOH) at different concentrations (10, 30, 60, and 90 %) in catalyzing the transesterification of waste cooking oil (WCO) to biodiesel. The transesterification process was optimized using a central composite design (CCD) for response surface modeling (RSM). The catalyst amount (3–11 wt%), reaction time (2–6 h), and methanol: oil ratio (10–30:1 mol/mol) were varied while keeping the reaction temperature (60 °C) and stirring speed (750 rpm) constant. The CCD generated a quadratic model that correlated with the experimental data with an R2 of 0.9545. The maximum yield obtained after model validation was 93.15 % at a methanol: oil ratio of 15:1, a reaction time of 3 h, and a catalyst amount of 5 wt% using the 30 % KOH/BFS catalyst. The biodiesel produced met the ASTM D6751 standards for fatty acid content, kinematic viscosity, density, and cloud point. The catalyst was able to sustain activity for a maximum of three cycles.

DOAJ Open Access 2024
DNA-Based Molecular Machines: Controlling Mechanisms and Biosensing Applications

Chunran Ma, Shiquan Li, Yuqi Zeng et al.

The rise of DNA nanotechnology has driven the development of DNA-based molecular machines, which are capable of performing specific operations and tasks at the nanoscale. Benefitting from the programmability of DNA molecules and the predictability of DNA hybridization and strand displacement, DNA-based molecular machines can be designed with various structures and dynamic behaviors and have been implemented for wide applications in the field of biosensing due to their unique advantages. This review summarizes the reported controlling mechanisms of DNA-based molecular machines and introduces biosensing applications of DNA-based molecular machines in amplified detection, multiplex detection, real-time monitoring, spatial recognition detection, and single-molecule detection of biomarkers. The challenges and future directions of DNA-based molecular machines in biosensing are also discussed.

DOAJ Open Access 2024
Control of Hybrid Wind Turbine and Diesel Generators using PLC

Abbas Hasan Wadah, Alhakeem Zaineb M.

This paper shows path of controlling hybrid system with wind and diesel generators via a programmable logic controller, these systems produce the required electrical power from different sources. This system can be used in different areas that have wind speeds between (10-180) km/h. When the winds are within this range, then the wind turbine generator is starting and suppling the electrical power to the load, if there is any fault is occurred or the wind is not within the working range then the wind turbine generator ceases and the diesel generator will start and supply the electrical power to the load.

Microbiology, Physiology
DOAJ Open Access 2022
Construction of Benzenesulfonamide Derivatives via Copper and Visible Light-induced Azides and S(O)<sub>2</sub>–H Coupling

Zhipeng Liang, Ya-Nan Wu, Yang Wang

We here have developed an S(O)<sub>2</sub>–N coupling between phenylsulfinic acid derivatives and aryl azides by dual copper and visible light catalysis. In this efficient and mild pathway, the reaction produces sulfonamide compounds under redox-neutral condition, which is mechanistically different from the nitrogen nucleophilic substitution reactions. Significantly, this transformation intends to utilize the property of visible light-induced azides to generate triplet nitrene and followed coupling with sulfonyl radicals in situ to achieve structurally diverse benzenesulfinamides in good yields.

Organic chemistry
DOAJ Open Access 2022
Simultaneous Determination of Amino Acids and Biogenic Amines by Liquid Chromatography Coupled to Mass Spectrometry for Assessing Wine Quality

Ainhoa Navarro-Abril, Javier Saurina, Sònia Sentellas

Biogenic amines (BAs) and free amino acids (AAs) are low-molecular nitrogenous compounds occurring in a wide range of foodstuffs, found in increased amount in different fermented foods, seafood, and wines. This study deals with the development of an analytical method based on liquid chromatography with tandem mass spectrometry with precolumn derivatization with dansyl chloride for the determination of BAs and AAs in musts, wines, and sparkling wines. The resulting compositional profiles have been exploited as potential descriptors of quality and other oenological issues using chemometric methods including principal component analysis (PCA) and partial analysis of least squares-discriminants (PLS-DA). Proline is the most abundant compound, and other remarkable species are lysine, ethanolamine, tyramine, histamine, and putrescine. Fermented samples (wines and sparkling wines) are much richer in both BAs and free AAs than the initial musts. Significant differences have also been noticed in the quality, as the best products display, in general, lower levels. The dissimilarities in the content of the analytes between the two grape varieties studied (pinot noir and xarel·lo) and those dealing with quality aspects have made it possible to establish a tree to classify the samples based on these two features with excellent classification rates.

Nutrition. Foods and food supply, Nutritional diseases. Deficiency diseases
DOAJ Open Access 2022
siRNA Functionalized Lipid Nanoparticles (LNPs) in Management of Diseases

Tutu Kalita, Saba Abbasi Dezfouli, Lalit M. Pandey et al.

RNAi (RNA interference)-based technology is emerging as a versatile tool which has been widely utilized in the treatment of various diseases. siRNA can alter gene expression by binding to the target mRNA and thereby inhibiting its translation. This remarkable potential of siRNA makes it a useful candidate, and it has been successively used in the treatment of diseases, including cancer. However, certain properties of siRNA such as its large size and susceptibility to degradation by RNases are major drawbacks of using this technology at the broader scale. To overcome these challenges, there is a requirement for versatile tools for safe and efficient delivery of siRNA to its target site. Lipid nanoparticles (LNPs) have been extensively explored to this end, and this paper reviews different types of LNPs, namely liposomes, solid lipid NPs, nanostructured lipid carriers, and nanoemulsions, to highlight this delivery mode. The materials and methods of preparation of the LNPs have been described here, and pertinent physicochemical properties such as particle size, surface charge, surface modifications, and PEGylation in enhancing the delivery performance (stability and specificity) have been summarized. We have discussed in detail various challenges facing LNPs and various strategies to overcome biological barriers to undertake the safe delivery of siRNA to a target site. We additionally highlighted representative therapeutic applications of LNP formulations with siRNA that may offer unique therapeutic benefits in such wide areas as acute myeloid leukaemia, breast cancer, liver disease, hepatitis B and COVID-19 as recent examples.

Pharmacy and materia medica
DOAJ Open Access 2022
Carbon-Nitride-Based Materials for Advanced Lithium–Sulfur Batteries

Wenhao Sun, Zihao Song, Zhenxing Feng et al.

Abstract Lithium–sulfur (Li–S) batteries are promising candidates for next-generation energy storage systems owing to their high energy density and low cost. However, critical challenges including severe shuttling of lithium polysulfides (LiPSs) and sluggish redox kinetics limit the practical application of Li–S batteries. Carbon nitrides (C x N y ), represented by graphitic carbon nitride (g-C3N4), provide new opportunities for overcoming these challenges. With a graphene-like structure and high pyridinic-N content, g-C3N4 can effectively immobilize LiPSs and enhance the redox kinetics of S species. In addition, its structure and properties including electronic conductivity and catalytic activity can be regulated by simple methods that facilitate its application in Li–S batteries. Here, the recent progress of applying CxNy-based materials including the optimized g-C3N4, g-C3N4-based composites, and other novel C x N y materials is systematically reviewed in Li–S batteries, with a focus on the structure–activity relationship. The limitations of existing C x N y -based materials are identified, and the perspectives on the rational design of advanced C x N y -based materials are provided for high-performance Li–S batteries.

DOAJ Open Access 2022
Numerical Analysis of Flow Characteristics of Upper Swirling Liquid Film Based on the Eulerian Wall Film Model

Ti Yue, Ti Yue, Jianyi Chen et al.

The Upper Swirling Liquid Film (USLF) phenomenon that occurs in the upper cylinder of the Gas–Liquid Cylindrical Cyclone (GLCC) separator is the direct cause of the low separation efficiency of the liquid phase. In this study, first, the USLF formation and development were simulated by an improved Eulerian-EWF coupled simulated method. By introducing a profile-defined inlet boundary and considering entrainment droplet size distributions, the Eulerian-EWF method got reasonable results which agreed well with the experimental. Then, the flow characteristics and changing laws of the USLF including film thickness, film axial velocity, and film tangential velocity were analyzed by this method under different gas–liquid flow rates. It suggested that the liquid film thickness often reaches a maximum at the aspect ratio (z-z0)/D=(1.2–3.9) above the tangential inlet, and the film thickness appears to be more sensitive to the gas flow than to the liquid flow. For the film axial velocity, the direction of film velocity on the front and back sides seems to be generally opposite. Finally, typical distributions of the aforementioned USLF variables were presented and corresponded accordingly, and two obvious rules were found. One is that the position where the thickest liquid film is located always corresponds to the position where the axial film velocity turns from positive to negative for the first time. The other is that the tangential film velocity has a strong synchronous relationship with the film thickness. This research might provide somewhat valid information for the future LCO-prevented measurement in GLCC separators.

Technology, Chemical technology
DOAJ Open Access 2022
Cloud adjustments from large-scale smoke–circulation interactions strongly modulate the southeastern Atlantic stratocumulus-to-cumulus transition

M. S. Diamond, M. S. Diamond, P. E. Saide et al.

<p>Smoke from southern Africa blankets the southeastern Atlantic Ocean from June to October, producing strong and competing aerosol radiative effects. Smoke effects on the transition between overcast stratocumulus and scattered cumulus clouds are investigated along a Lagrangian (air-mass-following) trajectory in regional climate and large eddy simulation models. Results are compared with observations from three recent field campaigns that took place in August 2017: ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES), CLouds and Aerosol Radiative Impacts and Forcing: Year 2017 (CLARIFY), and Layered Atlantic Smoke Interactions with Clouds (LASIC). The case study is set up around the joint ORACLES–CLARIFY flight that took place near Ascension Island on 18 August 2017. Smoke sampled upstream on an ORACLES flight on 15 August 2017 likely entrained into the marine boundary layer later sampled during the joint flight.</p> <p>The case is first simulated with the WRF-CAM5 regional climate model in three distinct setups: (1) FireOn, in which smoke emissions and any resulting smoke–cloud–radiation interactions are included; (2) FireOff, in which no smoke emissions are included; (3) RadOff, in which smoke emissions and their microphysical effects are included but aerosol does not interact directly with radiation. Over the course of the Lagrangian trajectory, differences in free tropospheric thermodynamic properties between FireOn and FireOff are nearly identical to those between FireOn and RadOff, showing that aerosol–radiation interactions are primarily responsible for the free tropospheric effects. These effects are non-intuitive: in addition to the expected heating within the core of the smoke plume, there is also a “banding” effect of cooler temperature (<span class="inline-formula">∼1</span>–2 K) and greatly enhanced moisture (<span class="inline-formula">&gt;2</span> g kg<span class="inline-formula"><sup>−1</sup></span>) at the plume top. This banding effect is caused by a vertical displacement of the former continental boundary layer in the free troposphere in the FireOn simulation resulting from anomalous diabatic heating due to smoke absorption of sunlight that manifests primarily as a few hundred meters per day reduction in large-scale subsidence over the ocean.</p> <p>A large eddy simulation (LES) is then forced with free tropospheric fields taken from the outputs for the WRF-CAM5 FireOn and FireOff runs. Cases are run by selectively perturbing one variable (e.g., aerosol number concentration, temperature, moisture, vertical velocity) at a time to better understand the contributions from different indirect (microphysical), “large-scale” semi-direct (above-cloud thermodynamic and subsidence changes), and “local” semi-direct (below-cloud smoke absorption) effects. Despite a more than 5-fold increase in cloud droplet number concentration when including smoke aerosol concentrations, minimal differences in cloud fraction evolution are simulated by the LES when comparing the base case with a perturbed aerosol case with identical thermodynamic and dynamic forcings. A factor of 2 decrease in background free tropospheric aerosol concentrations from the FireOff simulation shifts the cloud evolution from a classical entrainment-driven “deepening–warming” transition to trade cumulus to a precipitation-driven “drizzle-depletion” transition to open cells, however. The thermodynamic and dynamic changes caused by the WRF-simulated large-scale adjustments to smoke diabatic heating strongly influence cloud evolution in terms of both the rate of deepening (especially for changes in the inversion temperature jump and in subsidence) and in cloud fraction on the final day of the simulation (especially for the moisture “banding” effect). Such large-scale semi-direct effects would not have been possible to simulate using a small-domain LES model alone.</p>

Physics, Chemistry
DOAJ Open Access 2021
Matured Theobroma Cocoa Pod Extracts as Green Inhibitor for Acid Corrosion of Aluminium

P. Shwethambika, J. Ishwara Bhat

Matured Cocoa Pod Extract (MCPE) is prepared using Soxhlet extraction and is then characterized using Fourier Transform-Infra Red Spectroscopy (FT-IR), Gas Chromatography-Mass Spectroscopy (GC-MS). The thermal decomposition characteristics are studied using Thermo Gravimetric Analysis- Differential Thermal Analysis (TGA-DTA) method. FT-IR study confirmed the presence of hetero atoms like O, N, and GC-MS showed the presence of 15 chemical constituents of which 1,2-bis (trimethylsilyl) benzene is the major constituent present. TGA-DTA studies showed the thermal decomposition of chemical constituents which was supported by GC-MS data. The inhibition efficiency of MCPE is tested in 0.5M HCl medium taking aluminum as the target metal by Weight loss method (303K-308K). The anticorrosive property of MCPE was also tested using Electrochemical Impedance Spectroscopy and Potentiodynamic Polarization methods (303K). In all the methods, the inhibition efficiency of MCPE was found to increase with an increase in % volume of the MCPE exhibiting good agreement with each other. Also, inhibition efficiency decreased with an increase in temperature, showing adsorption of inhibitor is by physisorption and thermodynamic parameters are measured. Tafel plots showed MCPE could retard both anodic and cathodic reactions, predominantly acting as an anodic type of inhibitor. Surface morphological changes of the metal were studied using Scanning Electron Microscopy which confirmed that MCPE acted as an inhibitor by adsorption mechanism.

Chemical engineering, Chemistry
DOAJ Open Access 2021
A prioritization metric and modelling framework for fragmented saltmarsh patches restoration

Dongdong Shao, Kang Liu, Hannah L. Mossman et al.

Saltmarsh is a coastal ecosystem providing crucial ecosystem services, and its continued degradation and fragmentation has drawn increasing attention. However, how to effectively restore the connectivity between fragmented saltmarsh patches remains an open challenge. In this study, we developed a metric and modelling framework that prioritised saltmarsh patches for restoration. To demonstrate our approach, we simulated spatially explicit restoration schedules for Suaeda salsa patches at the Yellow River Delta National Nature Reserve, China, using three strategies: increasing-patch-area, increasing-number-of-patches and a benchmark unrestrictive prioritization strategy. We prioritised patches for restoration based on a number of widely used graph-theoretic landscape connectivity and metapopulation capacity metrics. Our simulation results suggested the rank connectivity-importance of extant patches was correlated within the group of graph-theoretic connectivity metrics or metapopulation capacity metrics, but unrelated across group. The unrestrictive prioritization strategy clearly outperformed the strategies of increasing-patch-area and increasing-number-of-patches which returned comparable connectivity restoration outcomes. For the more effective unrestrictive prioritization strategy, there were substantial differences in the simulated priority patches between metrics that considered stepping stone effects and those did not. While the former resulted in corridor-building priority patches that led to a more connected landscape throughout the region, the latter led to local clustering. We recommend use of the total probability of connectivity (PC) among the metrics we tested due to similarity of results to other metrics and its simulation efficiency. The proposed framework is readily applicable to prioritise areas for connectivity conservation and restoration in any monospecific ecosystem at the regional scale.

DOAJ Open Access 2017
Synthesis, Characterization of Zinc Complexes with Neutral α-Diimine Ligands and Application in Ring-opening Polymerization of ε-Caprolactone

Xiaodan Wang, Xuehong Liu, Ju Huang

A series of neutral α-diimine ligands with diacetyl and acenaphthenequinone skeletons were prepared by the reaction between diacetyl and the corresponding aromatic amine. These ligands reacted with ZnCl₂ to generate symmetric α-diimine zinc complexes C1–C10. Experimental results indicated that the α-diimine zinc complexes with a diacetyl skeleton (C1–C4) were active in ring-opening polymerization (ROP) of ε-caprolactone (ε-CL). The complexes with an acenaphthenequinone skeleton showed a small steric effect (C5, C8 and C9) but the complex substituted with an electron-withdrawing group (C10) showed high activity in the monomer conversion rate during ROP of ε-CL. The ROP catalysts of ?-CL demonstrated the mechanism of monomer activation in the presence of benzyl alcohol.

Halaman 16 dari 739953