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Showing records 3045 to 3069 of 43292. [First] Page: 1 119 120 121 122 123 124 125 126 127 Last
In Vitro Cytotoxicity Assessment of Abutilon pannosum Chloroform Fraction and Its Phytoconstituents Analysis
Mohammed Al-zharani, Fahd A. Nasr, Ibrahim O. Barnawi, Omar M. Noman, Rashed N. Herqash, Sami A. Alsufyani, Ashraf Ahmed Qurtam, Hassan A. Rudayni, Mohammed S. Aleissa, Ali S. Alqahtani.
June 13, 2023 (v1)
Subject: Biosystems
Keywords: Abutilon pannosum, apoptosis, cell cycle, MCF-7.
Plants continue to play a critical role in the discovery of effective compounds, especially anticancer drugs. Abutilon pannosum has been historically used as a therapeutic plant in the medicinal system. In this study, an ethanolic crude extract was prepared from the dried powder of A. pannosum and subsequently fractionated to produce chloroform, butanol, and water fractions. The crude extract and fractions were tested for their cytotoxic action against various cancer cells using the MTT assay. Additionally, the effect of the most promising fraction on the cell cycle arrest and apoptosis induction was studied using flow cytometry and RT-PCR. Western blotting was employed to confirm the expression of apoptosis-related proteins. The chemical constituents of the most promising fraction were further analyzed by GC-MS. Among all the tested extracts, the A. pannosum chloroform fraction (APCF) exhibited the most potent activity against MCF-7 breast cancer cells, with an IC50 value of 50 µg/mL.... [more]
Comparative Analysis of Three WEEE Management Scenarios Based on LCA Methodology: Case Study in the Municipality of Iasi, Romania
Simona Cecilia Ghiga, Isabela Maria Simion, Cătălina Filote, Mihaela Roșca, Raluca Maria Hlihor, Maria Gavrilescu.
June 13, 2023 (v1)
Subject: Environment
Keywords: e-waste, Energy, environmental impact, Life Cycle Assessment, recovery, waste management.
The increasing consumption of electrical and electronic equipment (EEE), correlated with the fast innovation pace in this field, generates a large amount of annual waste. The current established management practices cannot keep up with it, and the results are of increased significance given the negative effects on the environment and human health. Thus, the current study aimed to analyze the environmental impact of three different scenarios of waste electrical and electronic equipment (WEEE) management, following population awareness campaigns regarding its collection in the Municipality of Iasi, Romania. Data processing was carried out considering Life Cycle Assessment (LCA) methodology with the established functional unit for each scenario according to the collected amount. The results were quantified using the CML2001 and ReCiPe methods and showed that the highest environmental impact was obtained for scenario II (S2) (1.59 × 10−7 pers. equiv. using the CML2001 method and 32.7 pers.... [more]
The Upper Triassic Braided River Thin-Bedded Tight Sandstone in the Yanchang Formation, Ordos Basin: Sedimentary Characteristics, Seismic Forecasting Method, and Implication
Tongyang Lou, Congjun Feng, Mengsi Sun, Zhiqiang Chen.
June 13, 2023 (v1)
Keywords: braided river, sandbody architecture, seismic facies, tight sandstone.
In the Ordos Basin, Chang 81, a Member of the Yanchang Formation, features the development of braided river thin-bedded tight sandstones. These sandstones constitute one of the main production layers of tight oil and gas in the Yanchang Formation within the basin. This study integrates data from core samples, drilling, and seismic information to identify braided river thin-bedded sandstones in the Chang 81 Member at Daijiaping, Ordos Basin, using a method of constrained correlation between seismic waveform and seismic facies. This approach aids in determining the sedimentary microfacies types and reservoir characteristics of thin-bedded tight sandstones. We establish a quantitative fitting formula for the width-to-thickness ratio of braided channel sand bodies to finely characterize sand body stacking patterns and spatial distribution of thin-bedded tight sandstones in braided channels. Braided delta plain deposits in the Chang 81 Member at Daijiaping mainly comprise four types of sedi... [more]
Continuous Reactor Temperature Control with Optimized PID Parameters Based on Improved Sparrow Algorithm
Mingsan Ouyang, Yipeng Wang, Fan Wu, Yi Lin.
June 13, 2023 (v1)
Keywords: CSTR, Gauss Cauchy mutation, golden sine, improved sparrow search algorithm (ISSA), temperature control.
To address the problems of strong coupling and large hysteresis in the temperature control of a continuously stirred tank reactor (CSTR) process, an improved sparrow search algorithm (ISSA) is proposed to optimize the PID parameters. The improvement aims to solve the problems of population diversity reduction and easy-to-fall-into local optimal solutions when the traditional sparrow algorithm is close to the global optimum. This differs from other improved algorithms by adding a new Gauss Cauchy mutation strategy at the end of each iteration without increasing the time complexity of the algorithm. By introducing tent mapping in the sparrow algorithm to initialize the population, the population diversity and global search ability are improved; the golden partition coefficient is introduced in the explorer position update process to expand the search space and balance the relationship between search and exploitation; the Gauss Cauchy mutation strategy is used to enhance the ability of lo... [more]
Risk Assessment Model of Chemical Process Based on Interval Type-2 Fuzzy Petri Nets
Zhe Kan, Yaxuan Liang, Taoyan Zhao, Xiaolei Wang.
June 13, 2023 (v1)
Keywords: cyclohexane, fuzzy Petri nets, interval type-2 fuzzy sets, process system, risk assessment.
An interval type-2 fuzzy set and fuzzy Petri net combined risk assessment model for chemical production was proposed to solve the problems of disorganized hierarchy and poorly targeted measures, as well as the requirement for complex equipment associated with chemical production risk assessment. First, four different types of risk databases were established according to the production process of cyclohexane. Considering the intrinsic relationship between the risk factors in the fault database, the interval type-2 fuzzy set was used to improve the semantic transformation accuracy and calculate the confidence in the risk factors. The fuzzy Petri net model was used to simulate the dynamic development of accidents, and the parallel relationship between risk factors was intuitively described. Thereafter, the external relationship between risk factors was analyzed, and the net structure of each layer was divided to build a multilevel model. Finally, the catalyst activation process during cyc... [more]
Bifurcation Analysis of a Rotor-Casing Coupling System with Bolted Flange Connection under the Effect of Rotor-Casing Rubbing Fault
Zhimin Zhu, Chuanmei Wen, Tianliang Long, Long Jin, Yuqi Li.
June 13, 2023 (v1)
Keywords: bifurcation analysis, bolted flange connection, Dynamic Modelling, rotor-casing coupling system, rubbing fault.
This study mainly investigated the nonlinear vibration performance of a rotor-casing coupling system containing a bolted flange connection. The dynamic equations of the coupling system were developed while considering the radial stiffness of the bolted flange structure, which contained a spigot, squirrel cage with ball bearing, and rotor-casing coupling vibration. To study the influence of the disk casing fixed-point rubbing fault on the coupling system’s nonlinear dynamic performance, an analytical model of the nonlinear impact forces was established, which considered the contact and vibration responses of the rotor and casing. The frictional force was obtained based on the Coulomb friction law. The iterative analysis of motion equations was performed utilizing the Newmark method. Then, the nonlinear dynamic behaviors of the coupled systems were examined using data, including a bifurcation diagram, spectrum plot, greatest Lyapunov exponents, etc. The effects of rubbing fault on the dy... [more]
Antidiabetic Plants for the Treatment of Type 2 Diabetes Mellitus and Associated Bacterial Infections
Mario Adrián Tienda-Vázquez, Elda M. Melchor-Martínez, Joel H. Elizondo-Luévano, Roberto Parra-Saldívar, Javier Santiago Lara-Ortiz, Brenda Luna-Sosa, Christian Quintus Scheckhuber.
June 13, 2023 (v1)
Subject: Biosystems
Keywords: antibacterial plants, antidiabetic plants, bacterial infection, hyperglycemia, type 2 diabetes mellitus.
Type 2 diabetes mellitus (T2DM) is the metabolic disease with the highest morbidity rates worldwide. The condition is characterized by hyperglycemia, insulin resistance, hyperlipidemia, and chronic inflammation, among other detrimental conditions. These decrease the efficiency of the immune system, leading to an increase in the susceptibility to bacterial infections. Maintaining an optimal blood glucose level is crucial in relation to the treatment of T2DM, because if the level of this carbohydrate is lowered, the risk of infections can be reduced. Currently, this is achieved using synthetic drug treatments that seek to moderately inhibit digestive enzymes (e.g., α-amylase and α-glucosidase), such as acarbose, voglibose, miglitol, etc. However, the use of these compounds also generates unwanted side effects such as nausea, diarrhea, stomach aches and a loss of appetite. Therefore, there is an increasing demand to find effective and safe alternatives for treating T2DM, such as herbal tr... [more]
A Pilot-Scale Nanofiltration−Ultrafiltration Integrated System for Advanced Drinking Water Treatment: Process Performance and Economic Analysis
Fengxia Chen, Lifang Zhu, Jianzhong Tang, Dongfeng Li, Fang Yu, Fuqing Bai, Zhou Ye, Lu Cao, Nan Geng.
June 13, 2023 (v1)
Keywords: advanced treatment, drinking water, nanofiltration, ultrafiltration.
In this pilot study, the performance of an “ultrafiltration (UF) + nanofiltration (NF)” advanced treatment process in improving drinking water quality was investigated. The membrane performance and effluent qualities of three commercial NF membranes (Dow Filmtec NF270-400, VONTRON TAPU-LS, and GE Osmonics-HL8040F 400) were evaluated, and the reasons for the difference in effluent quality of these three NF membranes were analyzed. The results showed that UF as a pretreatment process could provide NF with stable and qualified influent. After passing through the UF unit, the turbidity of raw water decreased by 88.6%, and the SDI value was less than 3. Due to the small pore size of NF membranes, organics and polyvalent ions in raw water were further removed. With a water recovery of 90%, the conductivity, chemical oxygen demand (CODMn), and hardness of NF effluent are significantly improved. The three commercial NF membranes showed different performance advantages. Among them, Dow Filmtec... [more]
Research on the Control Strategy of Urban Integrated Energy Systems Containing the Fuel Cell
Yuelong Wang, Weiqing Wang.
June 9, 2023 (v1)
Keywords: control strategy, fuel cell, fuzzy logic control, urban integrated energy system.
As a new type of energy with the advantages of high efficiency, clean and pollution-free, fuel cells have attracted the attention of many experts and scholars. The efficient utilization of fuel cells will certainly become the mainstay of energy transformation and environmental protection. However, fuel cells have low power density, soft electrical output characteristics, and significantly delayed response to sudden load changes. When fuel cells are used as power supply energy alone, the output voltage fluctuates greatly, and the power supply reliability could be higher. To increase the fuel cell’s service life in real world applications, a DC converter and an appropriate auxiliary energy storage power supply are combined to form a fuel cell hybrid power supply system that makes efficient use of the auxiliary energy storage system’s availability, enhances the power supply system’s adaptability through dynamic reconfiguration, and provides better flexibility overall. This work proposes a... [more]
A Hybrid Model to Assess the Remaining Useful Life of Proton Exchange Membrane Fuel Cells
Qing Du, Zhigang Zhan, Xiaofei Wen, Heng Zhang, Yaowen Tan, Shang Li, Mu Pan.
June 9, 2023 (v1)
Keywords: hybrid model, prognostic, proton exchange membrane fuel cells (PEMFCs), remaining useful life (RUL).
Durability and remaining useful life (RUL) prediction techniques are ones of the key issues for proton exchange membrane fuel cell (FC) commercialization. Herein, the performance degradation of an FC is analyzed based on the whole lifetime experimental data (up to 6500 h). The voltage model with different patterns is developed based on the voltage data, which can be easily measured. The mechanism model is developed based on the evolution of degradation indices reflecting the degradation state. However, the former is sensitive to the local and periodic changes in the voltage curve, leading to a large prediction error, and the latter requires aging data from complex and high-cost characterization, limiting the practical applications. Therefore, a hybrid prediction model combining the voltage and mechanism model is proposed where the respective weight of each model is dynamically determined based on their local prediction errors. The results reveal that the maximum errors in RUL predictio... [more]
An Ultra Compact Microstrip Branch Line Coupler with Wide Stopband Using LCL Filter and Meandered Stubs for Microwave Applications
Muhammad Akmal Chaudhary, Saeed Roshani, Sobhan Roshani.
June 9, 2023 (v1)
Keywords: communication systems, harmonic suppression, lumped component, microstrip coupler.
A branch line coupler (BLC) with ultra-compact size and harmonic suppression ability using an LCL filter and meandered stubs is proposed in this paper. There are some important factors in microstrip coupler design, including size reduction, harmonic suppression, and low insertion loss. Thus, improving each of these factors will contribute to a more efficient design. In the proposed circuit, for the first time, LCL filters, including four T-shaped circuits and four meandered line open-ended stubs, were used together to reduce the circuit size and suppress unwanted harmonics. The proposed LCL filters, incorporated in the BLC branches, resulted in superior size reduction and harmonic suppression for the presented BLC. The proposed BLC correctly worked at 900 MHz with 300 MHz operating bandwidth, which showed 33% fractional bandwidth (FBW). Additionally, a wide suppression band from 1.4 GHz to 8.8 GHz, with more than 20 dB attenuation level was obtained, which suppressed the second to nint... [more]
Dietary Fiber from Plant-Based Food Wastes: A Comprehensive Approach to Cereal, Fruit, and Vegetable Waste Valorization
Sofia Plakantonaki, Ioannis Roussis, Dimitrios Bilalis, Georgios Priniotakis.
June 9, 2023 (v1)
Keywords: agri-food waste, agro-polymers, cellulose, circular economy, food products, insoluble dietary fibers (IDF), textiles.
The agri-food industry generates significant quantities of plant-based food waste from processing, which offers a valuable research opportunity aimed at minimizing and managing these wastes efficiently in support of zero waste and/or circular economies. In order to achieve food security, all of these wastes can be valorized using downstream processes in an integrated manner, which results in the conversion of waste into secondary raw materials. Specifically, plant-based food wastes and/or byproducts are recognized sources of bioactive chemicals, including dietary fibers that are beneficial as food additives or functional food ingredients that can meet the technological and functional requirements of health-promoting value-added products. Additionally, cellulosic ingredients can be utilized directly within nonfood industries, such as textiles, resulting in a reduction in the environmental impact of secondary raw materials, as well as an increase in market acceptance compared to those cu... [more]
Making a Soft Elastic Pulsation Pump (SEPP)
Hao Gu, Yun Xia, Yu Zhang, Xiao Dong Chen.
June 9, 2023 (v1)
Subject: Materials
Keywords: 3D printing, mock circulation, silicone-based device, soft-elastic pulsation pump.
In this work, a soft-elastic pulsation pump (SEPP) has been made and investigated. Here, 3D printing was used to make casting molds and a melt-removal method using wax was employed. The SEPP was made of silicone rubber and driven by an external squeezing mechanism. A silicone one-way valve was also made which prevented backflow after the fluid was squeezed out of the pump chamber. The material characteristics of the SEPP including durability were examined. The pump operating parameters were confirmed to differential pressure of 100 mm Hg in a close flow loop. The average flow rate was 2 L/min, while yielding a peak flow of 8 L/min, and a stroke volume of 70 mL. A preliminary trial using fresh animal blood had shown that the SEPP has good protection on the blood. Therefore, within the resources available, an interesting idea for an effective SEPP has been proposed and realized in the laboratory. The technical details of the SEPP described, and the experimental results reported here form... [more]
Comparative Analysis of the Hydrodynamic Performance of Arc and Linear Flapping Hydrofoils
Ertian Hua, Wenchao Zhu, Rongsheng Xie, Zhongxin Su, Haitao Luo, Linfeng Qiu.
June 9, 2023 (v1)
Keywords: flapping hydrofoil, flapping mode, numerical simulation, pumping performance, ultra-low head.
In order to improve the hydrodynamic performance of flapping hydrofoils and solve the problem of insufficient hydrodynamic force in plain river network areas, in this study, we consider the more realistic swing of fish tails and propose an arc flapping method, the coupled motion of which has three degrees of freedom: heave, pitch, and lateral displacement. Two flapping methods, positive arcs and negative arcs, were derived on the basis of the lateral displacement direction. By using the finite volume method (FVM) and overlapping grid technology, a numerical simulation was conducted to compare and analyze the pumping performance of three types of flapping hydrofoil, namely, linear, positive arcs, and negative arcs, in order to further provide guidance for the structural optimization of bionic pumping devices. The results showed that the wake vortex structures of the three flapping modes all had anti-Kármán vortex streets, but the wake vortex of linear flapping deflected upward, and the... [more]
Development and Numerical Optimization of a System of Integrated Agents for Serial Production Lines
Hisham Alkhalefah, Usama Umer, Mustufa Haider Abidi, Ahmed Elkaseer.
June 9, 2023 (v1)
Keywords: AI, buffer size, decision support system, Optimization, SIGN, SPL.
In modern high-volume industries, the serial production line (SPL) is of growing importance due to the inexorable increase in the complexity of manufacturing systems and the associated production costs. Optimal decisions regarding buffer size and the selection of components when designing and implementing an SPL can be difficult, often requiring complex analytical models, which can be difficult to conceive and construct. Here, we propose a model to evaluate and optimize the design of an SPL, integrating numerical simulation with artificial intelligence (AI). Numerous studies relating to the design of SPL systems have been published, but few have considered the simultaneous consideration of a number of decision variables. Indeed, the authors have been unable to locate in the published literature even one work that integrated the selection of components with the optimization of buffer sizes into a single framework. In this research, a System of Integrated Agents Numerical Optimization (S... [more]
Composite Fault Diagnosis of Aviation Generator Based on EnFWA-DBN
Zhangang Yang, Xingwang Bao, Qingyu Zhou, Juan Yang.
June 9, 2023 (v1)
Keywords: composite fault, deep belief network, enhanced fireworks algorithm, extreme learning machine.
Because of the existence of composite faults, which consist of both short-out and eccentricity faults, the characteristics of the output voltage and internal magnetic field of aviation generators are less different than those of single short-out faults; this causes the eccentricity fault to be difficult to identify. In order to solve this problem, this paper proposes a fault diagnosis method using an enhanced fireworks algorithm (EnFWA) to optimize a deep belief network (DBN). The aviation generator model is built according to the finite element method (FEM), whereas the output of different combinations of composite faults are obtained using simulations. The EnFWA algorithm is used to train and optimize the DBN network to obtain the best structure. Meanwhile, an extreme learning machine (ELM) classifier performs fault diagnosis and classification on the test data. The diagnosis results show that a pinpoint accuracy can be achieved using the proposed method in the diagnosis of composite... [more]
Modification of Meso-Micromixing Interaction Reaction Model in Continuous Reactors
Junan Jiang, Ning Yang, Hanyang Liu, Jianxin Tang, Chenfeng Wang, Rijie Wang, Xiaoxia Yang.
June 9, 2023 (v1)
Subject: Optimization
Keywords: continuous reactors, mesomixing, micromixing, Optimization.
The yields of chemical reactions are highly dependent on the mixing pattern between reactants. Herein, we report the modification of a meso-micromixing interaction reaction model which is applied in batch reactors by leveraging the flow characteristics in the continuous reactors. Both experimental and model-predicted yields were compared using the classical Villermaux−Dushman method in a self-designed split and recombination reactor. This modified model significantly reduced the error in predicted product yields from approximately 15% to within 3%, compared to a model containing the micromixing term only. The effects of flow rates and reactor structure parameters on mixing performance were analyzed. We found that increasing flow rates and the degree of twist in the mixing element’s grooves, as well as decreasing the cross-sectional area of grooves, improved mixing performance. The optimization of reactor flow rates and structural parameters was achieved by combining Gaussian process re... [more]
Prediction and Application of Surface Settlement of Shallow Buried Tunnels Taking into Account Strata Slip Cracks
Zhonggang Ma, Xiaofei Xie, He Jia, Junwei Zhao, Sunwen He, Xiaohua Wang.
June 9, 2023 (v1)
Subject: Other
Keywords: Peck formula, settlement prediction, shallow tunnel, strata slip crack.
The empirical formula is one of the traditional methods used for predicting ground deformation settlement caused by tunnel excavation. Due to its rationality and simplicity, the Peck formula is widely used for predicting surface subsidence. However, due to its limitations, it is necessary to modify it when predicting surface settlement caused by tunnel excavation in different strata. In this paper, a correction formula for the width coefficient of a tunnel surface settlement slot is derived from the Peck formula by taking into account the theory of strata slip cracks. Values are calculated using the correction formula and compared with measured data to verify the effectiveness of the correction formula. The main conclusions are: (1) The position corresponding to the width of the settlement in the Peck curve is the point where the formation is most prone to slip cracking. (2) In the general shallow buried case, the settlement groove width coefficient K and the internal friction angle φ... [more]
An Experimental Study on the Elbow Pressure Drop and Conveying Stability of Pneumatic Conveying for Stiff Shotcrete Based on Response Surface Methodology
Zhenjiao Sun, Lianjun Chen, Guanguo Ma, Hui Ma, Kang Gao.
June 9, 2023 (v1)
Keywords: conveying stability, elbow pressure drop, pneumatic conveying, response surface method, stiff shotcrete.
The pressure drop and conveying stability caused by the bend significantly affect the pneumatic conveying process of stiff shotcrete, which is the key to solving the problem of long-distance transportation. In this paper, the effects of different air velocities (32 m/s, 36 m/s, 40 m/s), water-cement ratios (0.1, 0.2, and 0.3), and bending-diameter ratios (4, 12, and 20) on the pressure drop of the elbow R1 and conveying stability R2 are studied using the response surface method. The conveying stability is characterized by the pressure variation coefficient (C.V). The response surface graph aids in the intuitive analysis of the effects of these variables. The results show that the impact of air velocity on R1 and R2 is exceptionally significant, and the interaction of each factor on the response value is analyzed. The response value and the quadratic polynomial regression equation between the various factors are obtained in addition to the flow characteristics of stiff shotcrete under d... [more]
Special Issue on “Composting in the Framework of a Circular Economy”
Antoni Sánchez.
June 9, 2023 (v1)
Subject: Environment
Composting has been recognized as a sustainable technology to treat and manage organic waste [...]
Generalized Distribution Feeder Switching with Fuzzy Indexing for Energy Saving
Whei-Min Lin, Wen-Chang Tsai.
June 9, 2023 (v1)
Keywords: fuzzy algorithm, load balance, membership functions, network reconfiguration.
The objective of this study is to analyze feeder loss minimization and load balance under given constrains. Effective methods are required for feeder switching/reconfiguration. Feeder switching is a mixed-integer large-scale combinatorial problem for optimization, not easily solvable with classical optimization techniques, especially involving a great number of switches. This paper proposes a fuzzy indexing algorithm for feeder switching, with membership functions defined for switches such as thermometers or indices. The optimal switches can be determined through fuzzy index operations. With membership functions defined, the developed method used numerical operations for indices instead of the “set” operation or the min-max operations of traditional fuzzy algorithms. The optimization problem becomes a simple numeric calculation instead of a large-scale sorting problem and is much faster than most algorithms. It greatly reduces the computation time and enhances efficiency, which is suit... [more]
Interfacial Adsorption Mechanism of Diethyldithiocarbamate in High-Sulfur Residue Flotation
Hong Liu, Jing He, Tao Luo, Jie Dai, Shuqiong Cao, Shenghai Yang, Chaobo Tang, Changhong Wang, Yongming Chen.
June 9, 2023 (v1)
Subject: Materials
Keywords: coadsorption model, DFT, diethyldithiocarbamate, flotation, high-sulfur residue.
Diethyldithiocarbamate (DDTC) is employed in the sulfide ore flotation process due to its excellent collection performance. Herein, we investigated the interfacial adsorption behavior of DDTC on the four main mineral phases of high-sulfur residue: sulfur, pyrite, sphalerite, and lead sulfate. The adsorption behavior of DDTC and H2O, namely, the adsorption structure and the energy and electron localization function cross section, were explored using density function theory calculation. The results were helpful in constructing a coadsorption model of DDTC and H2O, which was validated by pure mineral flotation and characterization of Fourier transform infrared spectra. The coadsorption model indicated that the adsorption of DDTC on sulfur, sphalerite, and lead sulfate was weak with physical bonding, while its adsorption on pyrite was strong with chemical bonding. Practical bench-scale high-sulfur residue flotation was performed, and the result was different from that obtained from pure mi... [more]
Construction of a Green-Comprehensive Evaluation System for Flotation Collectors
Hongxiang Xu, Jiahua Cui, Yijun Cao, Lin Ma, Guixia Fan, Gen Huang, Kejia Ning, Jingzheng Wang, Yuntao Kang, Xin Sun, Jiushuai Deng, Shan Li.
June 9, 2023 (v1)
Keywords: analytic hierarchy process, collector, comprehensive evaluation, fuzzy comprehensive evaluation, green evaluation.
The evaluation of flotation reagents performs an important role in the selection and green application of reagents. The green indexes and effect indexes of flotation collectors were selected by data literature method, system analysis method, mathematical model method, and qualitative and quantitative analysis method, and the green evaluation system of flotation collectors, flotation effect evaluation system, and comprehensive evaluation system of flotation collectors were established. The normalization method and expert evaluation methods were adopted to obtain the grade classification of quantitative and qualitative indicators, respectively. The analytic hierarchy process (AHP) was used to determine the weight of secondary indicators and tertiary indicators of the evaluation system and the weight of indicators at a lower level. Applying the fuzzy comprehensive evaluation (FCE), the trapezoidal function is selected to determine the index affiliation, the index system score is calculate... [more]
Effects of Lead Pollution on Photosynthetic Characteristics and Chlorophyll Fluorescence Parameters of Different Populations of Miscanthus floridulus
Jianqiao Qin, Xueding Jiang, Jianhua Qin, Huarong Zhao, Min Dai, Hao Liu, Xi Chen.
June 9, 2023 (v1)
Subject: Environment
Keywords: chlorophyll fluorescence, gas exchange parameter, lead pollution, Miscanthus floridulus.
This study was conducted in order to study the effect of different concentrations of lead pollution on the photosynthetic characteristics and growth of Miscanthus floridulus, and to reveal its photosynthetic adaptability to lead stress. The differences of gas exchange parameters, chlorophyll fluorescence characteristics and photosynthetic pigment of two Miscanthus floridulus populations, one population from Boluo an uncontaminated site, and another population from Dabaoshan, a mine site, were compared and studied through nutrient solution culture experiments treated with heavy metal lead (Pb) in green house. The results showed that (1) under Pb stress, the net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), intercellular carbon dioxide concentration (Ci), and chlorophyll content (Chl) of the leaves of the two populations decreased in different amplitude. Under moderate and severe Pb stress (80 mg·L−1, 120 mg·L−1, 240 mg·L−1), the plant biomass of non-minin... [more]
Research on Landslide Displacement Prediction Based on DES-CGSSA-BP Model
Lu Fang, Jianping Yue, Yin Xing.
June 9, 2023 (v1)
Keywords: BP neural network model, chaotic Gaussian mutation sparrow search algorithm (CGSSA), double exponential smoothing (DES), landslide displacement, prediction accuracy.
A landslide is a type of natural disaster that has the highest frequency, the widest distribution and the heaviest losses worldwide; landslides seriously threaten human life and property and major engineering facilities. Therefore, it is important to improve landslide displacement prediction technology to avoid and mitigate landslide disasters. A landslide displacement prediction method based on a chaotic Gaussian mutation sparrow search algorithm-optimised BP neural network (CG-SSA-BP) is proposed to address the problems of the traditional sparrow search algorithm (SSA)-optimised BP (SSA-BP) neural network; it tends to fall into local optima, and it has slow convergence and a low prediction accuracy for landslide displacement prediction. This paper takes the Baishui River landslide in the Three Gorges reservoir area as the research object, and the double exponential smoothing (DES) method is used to decompose the landslide displacement into a trend term and a periodic term to solve th... [more]
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