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Records with Subject: Environment
Showing records 3226 to 3250 of 3265. [First] Page: 126 127 128 129 130 131 Last
How Does Public Sentiment Affect the Socially Responsible Behavior of Construction Enterprises?
Xiaoxu Dang, Shihui Wang, Xiaopeng Deng, Ziming Zhang, Na Zhang, Hongtao Mao
February 21, 2023 (v1)
Subject: Environment
Keywords: corporate social responsibility, environmental corporate social responsibility, evolutionary game, rank-dependent expected utility (RDEU) theory
The negative environmental impact of the construction sector has garnered global attention, and as the “primary force” in achieving the “double carbon” target, green development is urgent, and social responsibility practices cannot be postponed. An evolutionary game model was constructed by combining the rank-dependent expected utility (RDEU) theory and the evolutionary game theory to understand the interaction mechanism between participants’ emotions and decisions, taking into account the characteristics of construction enterprises and the public regarding irrational decisions under heterogeneous emotional combinations. The study demonstrates that: (1) there is probability in the choice of rational strategies, and emotion is an irrational factor that can affect strategy choice. (2) The evolutionary trend of the strategy choice of the game subjects is altered by emotional intensity and emotional propensity. The optimism of construction enterprises inhibits their socially responsible pr... [more]
Tool Wear in Nickel-Based Superalloy Machining: An Overview
Rui Wang, Dayong Yang, Wei Wang, Furui Wei, Yuwei Lu, Yuqi Li
February 21, 2023 (v1)
Subject: Environment
Keywords: extended tool life, failure mechanism, nickel-based superalloys, optimization of cutting environment, tool wear
Nickel-based superalloys have been widely used in the aerospace, petrochemical, and marine fields and others because of their good oxidation resistance, corrosion resistance, stability, and reliability at various temperatures. However, as a nickel-based superalloy is a kind of processed material, in the cutting process a large amount of cutting heat is generated due to the interaction between the tool and the workpiece. At the same time, the low thermal conductivity of the workpiece causes a large amount of cutting heat to accumulate at the contact point, resulting in serious tool wear, reduced tool life, frequent tool changes, and other problems, which increase the production cost of the enterprise. This paper introduces the tool wear mechanisms (abrasive wear, adhesive wear, plastic deformation, chemical wear, etc.) in the machining process of nickel-based superalloys and summarizes the research status of failure mechanisms, tool wear optimization, etc. Based on a review of the exist... [more]
Valorization of Bayer Red Mud in a Circular Economy Process: Valuable Metals Recovery and Further Brick Manufacture
Carlos Leiva, Fátima Arroyo-Torralvo, Yolanda Luna-Galiano, Rosario Villegas, Luis Francisco Vilches, Constantino Fernández Pereira
February 21, 2023 (v1)
Subject: Environment
Keywords: circular economy, fired brick, heavy metals, hydrometallurgy, natural radionuclides, red mud
In this work, the recovery of valuable metals from Bayer red mud using hydrometallurgical techniques and the subsequent use of the solid remaining after leaching as the principal component of the fired bricks were analyzed. Water, sulfuric acid, and sodium hydroxide were used as leaching agents. Different L/S ratios and contact times were also tested. According to technical, economic, and environmental considerations, the optimal conditions to recover valuable elements from red mud were 2 M H2SO4, in contact for 24 h, with an L/S ratio = 5. Under these conditions, high leaching yields of valuable elements such as La (47.6%) or V (11%) were achieved. After the leaching process, the remaining solid was mixed with clay and water to produce bricks. Two doses of red mud (50 and 80% w) and two different sintering temperatures (900 and 1100 °C) were tested. When the proportion of treated RM in the mix was increased, the compressive strength of the bricks was reduced, but it was increased as t... [more]
Microbial-Mediated Emissions of Greenhouse Gas from Farmland Soils: A Review
Han Wang, Rui Zhao, Dan Zhao, Shejiang Liu, Jianfeng Fu, Yuxin Zhang, Nan Dai, Dan Song, Hui Ding
February 21, 2023 (v1)
Subject: Environment
Keywords: farmland soil, greenhouse gas emission, microalgae biofertilizer, microorganism
The greenhouse effect is one of the concerning environmental problems. Farmland soil is an important source of greenhouse gases (GHG), which is characterized by the wide range of ways to produce GHG, multiple influencing factors and complex regulatory measures. Therefore, reducing GHG emissions from farmland soil is a hot topic for relevant researchers. This review systematically expounds on the main pathways of soil CO2, CH4 and N2O; analyzes the effects of soil temperature, moisture, organic matter and pH on various GHG emissions from soil; and focuses on the microbial mechanisms of soil GHG emissions under soil remediation modes, such as biochar addition, organic fertilizer addition, straw return and microalgal biofertilizer application. Finally, the problems and environmental benefits of various soil remediation modes are discussed. This paper points out the important role of microalgae biofertilizer in the GHG emissions reduction in farmland soil, which provides theoretical suppor... [more]
A Hybrid OPA and Fuzzy MARCOS Methodology for Sustainable Supplier Selection with Technology 4.0 Evaluation
Chia-Nan Wang, Thi Thanh Tam Nguyen, Thanh-Tuan Dang, Ngoc-Ai-Thy Nguyen
February 21, 2023 (v1)
Subject: Environment
Keywords: fuzzy MARCOS, Industry 4.0, MCDM, OPA, sustainable evaluation
The concern of sustainable supplier selection has been raised recently in organizations’ decision making to enhance their competitiveness. Many tools have been developed to support supplier evaluation, yet the factors of Industry 4.0 (I4.0) have been ignored despite their impact on sustainable performance. Hence, this paper aims to include the technology of I4.0 as the criteria to evaluate the competence of suppliers in sustainability. Multiple-criteria decision making (MCDM) has been used to build decision-making systems; thus, this study employed two advanced methods of MCDM, the ordinal priority approach (OPA) and measurement of alternatives and ranking according to compromise solution (MARCOS) in a fuzzy environment. To test the feasibility of the proposal, five manufacturers of Vietnam’s leather and footwear industry were hypothetically assigned. Firstly, the evaluation criteria were weighted by OPA. Then, the ranking of alternatives was determined by fuzzy MARCOS. The results sho... [more]
Numerical Study of Leakage and Diffusion of Underwater Oil Spill by Using Volume-of-Fluid (VOF) Technique and Remediation Strategies for Clean-Up
Rengguang Liu, Shidong Ding, Guoshuai Ju
February 21, 2023 (v1)
Subject: Environment
Keywords: drilling platform, leakage and diffusion, polluted water, remediation strategies, underwater oil spill, VOF
An oil spill accident will cause serious harm to marine ecology and the environment. Rapid response and effective prevention methods are required to minimize the damage of oil spill accidents. The critical problems that marine emergency rescue teams face are when the spilled oil reaches the sea surface, the extent of the spilled oil, and how far they are from the drilling platform. However, there is no reliable model to predict the diffusion distance of spilled oil. Accurately predicting the diffusion characteristics of underwater spilled oil can provide timely and accurate information for the treatment of oil spill accidents and guide the correct implementation of emergency treatment. In this paper, the computational fluid dynamics (CFD) method was used to establish a two-phase flow model for the diffusion of a submarine oil spill. The volume-of-fluid (VOF) technique was implemented to track the interface between oil−water phases. The effects of different parameters on leakage and dif... [more]
Toward Net-Zero: The Barrier Analysis of Electric Vehicle Adoption and Transition Using ANP and DEMATEL
Tsai-Chi Kuo, Yung-Shuen Shen, Napasorn Sriwattana, Ruey-Huei Yeh
February 21, 2023 (v1)
Subject: Environment
Keywords: ANP, DEMATEL, electrical vehicle transition, multi-criteria decision making, SDG 12
Global greenhouse gas emissions must be reduced to achieve net-zero carbon emissions. One of the solutions for the reduction of greenhouse gas emissions is the adoption and transition from conventional vehicles to electrical vehicles (EVs). Previously, most research on EVs have been from a consumer adoption perspective, few of them are from industry transition and consumer adoption perspectives simultaneously. This also highlights the importance of SDG 12 (responsible for consumption and production). Additionally, the analyses were mostly obtained using one methodology and demonstrated only by weighting without relationships among factors. To consider the problem of adoption and transition, a systematic method should be developed. Therefore, this study intends to identify, prioritize, and display the relationship between EV adoption barriers from an automotive industry perspective using an analytic network process (ANP) and the decision-making trial and evaluation laboratory (DEMATEL)... [more]
Differential Evolution with Adaptive Grid-Based Mutation Strategy for Multi-Objective Optimization
Samira Ghorbanpour, Yuwei Jin, Sekyung Han
February 21, 2023 (v1)
Subject: Environment
Keywords: adaptive grid environment, binomial crossover, Differential Evolution (DE), multi-objective optimization, mutation
Differential Evolution (DE) has been extensively adopted for multi-objective optimization due to its efficient and straightforward framework. In DE, the mutation operator influences the evolution of the population. In this paper, an adaptive Grid-based Multi-Objective Differential Evolution is proposed to address multi-objective optimization (ad-GrMODE). In ad-GrMODE, an adaptive grid environment is employed to perform a mutation strategy in conjunction with performance indicators. The grid reflects the convergence and diversity performance together but is associated with the user-specified parameter “div”. To solve this problem, we adaptively tune the parameter “div”. Among the DE mutation strategies, “DE/current-to-best/1” is applied extensively in single-objective optimization. This paper extends the application of “DE/current-to-best/1” to multi-objective optimization. In addition, a two-stage environmental selection is adopted in ad-GrMODE, where in the first stage, one-to-one sel... [more]
Analysis of Hydrothermal Solid Fuel Characteristics Using Waste Wood and Verification of Scalability through a Pilot Plant
Tae-Sung Shin, Hun-Bong Lim, Jae-Chul Lee, Hyun-Ik Yang
February 21, 2023 (v1)
Subject: Environment
Keywords: biosolid fuel, hydrothermal carbonization, laboratory-scale, pilot-scale, solid fuel, waste wood
Increases in energy demand and waste are a major cause of natural resource depletion and environmental pollution, and technology capable of processing waste to convert it into energy is required to mitigate this issue. Hydrothermal carbonization (HTC) is an example of this technology that can convert waste into energy, and various studies have been conducted using it for fuel conversion. This study focused on the production of a solid fuel equivalent to coal for power generation through HTC processes using waste wood. Unlike previous work, which consists only of laboratory-scale HTC experiments, we confirmed scalability through pilot-scale HTC experiments. Overall, it was possible to convert waste wood into HTC solid fuel with a calorific value of over 27,000 kJ/kg through the pilot plant HTC process. Additionally, heavy metal and hazardous substance analyses proved that it can be used as a biosolid fuel.
Temporal and Spatial Evolution Law of the Freezing Temperature Field of Water-Rich Sandy Soil under Groundwater Seepage: A Case Study
Wei Long, Chuanxin Rong, Hao Shi, Shiqing Huang, Bin Wang, Yin Duan, Zhi Wang, Xin Shi, Haochen Ma
February 21, 2023 (v1)
Subject: Environment
Keywords: freezing temperature field, groundwater seepage, hydrothermal coupling, numerical calculation, temporal and spatial evolution, water-rich sandy soil
We aimed to assess the temporal and spatial evolution law of the freezing temperature field of water-rich sandy soil in underground freezing engineering, taking the newly built west ventilating shaft freezing engineering in the Yuandian No. 2 Mine of Huaibei Coalfield as the engineering background. The influence of groundwater seepage on the freezing temperature field was qualitatively analyzed using field measured data. Based on the mixture medium theory, a hydrothermal coupling numerical calculation model of the freezing temperature field was established. The temporal and spatial evolution law of the freezing temperature field of water-rich sandy soil was obtained via the analysis of field measured data and numerical calculation results. It was found that the proportion of water that froze into ice in the soil mass within the freezing pipe circle is more than that outside of the freezing pipe circle; thus, the phase change in the soil mass within the freezing pipe circle is highly ob... [more]
The Effect of Medical Device Regulations on Deploying a Lean Six Sigma Project
Vincent McGrane, Olivia McDermott, Anna Trubetskaya, Angelo Rosa, Michael Sony
February 21, 2023 (v1)
Subject: Environment
Keywords: 21CFR 820, continuous improvement, ISO 13485, Lean Six Sigma, medical device, MedTech, validation
This paper investigates the differences in timelines involved in Lean Six Sigma (LSS) project deployment in a regulated industry versus in an unregulated one. Two case studies utilising Lean Six Sigma methods—in order to compare the transfer of manual manufacturing lines within a medical device and electronics manufacturing site—are discussed and utilised. This research aims to show the effects of regulatory procedures on LSS project implementation and timelines. This study particularly highlights how a regulatory environment can be a barrier, or bottleneck, to project management, continuous improvement, and engineering changes in the MedTech or medical device manufacturing industry. The results of this study represent an important first step towards a full understanding of the influence of regulations on operations in medical devices and, by extension, on pharmaceutical manufacturing industries on a global scale. The research limitations are that the data collected were from two speci... [more]
Tertiary Wastewater Treatment Technologies: A Review of Technical, Economic, and Life Cycle Aspects
Dimitris P. Zagklis, Georgios Bampos
February 21, 2023 (v1)
Subject: Environment
Keywords: chlorination, constructed wetlands, life cycle assessment, microalgae, ozonation, technoeconomic, tertiary wastewater treatment
The activated sludge process is the most widespread sewage treatment method. It typically consists of a pretreatment step, followed by a primary settling tank, an aerobic degradation process, and, finally, a secondary settling tank. The secondary effluent is then usually chlorinated and discharged to a water body. Tertiary treatment aims at improving the characteristics of the secondary effluent to facilitate its reuse. In this work, through a literature review of the most prominent tertiary treatment methods, a benchmarking of their technical efficiency, economic feasibility, and environmental impact was carried out. The photo-Fenton method proved to be the most technically efficient process, significantly reducing the microbial load and pharmaceutical content (by 4.9 log and 84%, respectively) of the secondary effluent. Chlorination and UV irradiation exhibited the lowest treatment costs (0.004 EUR/m−3) and the lowest global warming potential (0.04 and 0.09 kg CO2eq. m−3, respectivel... [more]
Life Cycle Energy Consumption and Greenhouse Gas Emissions Analysis of Primary and Recycled Aluminum in China
Tianduo Peng, Lei Ren, Ershun Du, Xunmin Ou, Xiaoyu Yan
February 21, 2023 (v1)
Subject: Environment
Keywords: energy consumption, greenhouse gas emissions, Life Cycle Analysis, primary and recycled aluminum
Aluminum production is a major energy consumer and important source of greenhouse gas (GHG) emissions globally. Estimation of the energy consumption and GHG emissions caused by aluminum production in China has attracted widespread attention because China produces more than half of the global aluminum. This paper conducted life cycle (LC) energy consumption and GHG emissions analysis of primary and recycled aluminum in China for the year 2020, considering the provincial differences on both the scale of self-generated electricity consumed in primary aluminum production and the generation source of grid electricity. Potentials for energy saving and GHG emissions reductions were also investigated. The results indicate that there are 157,207 MJ of primary fossil energy (PE) consumption and 15,947 kg CO2-eq of GHG emissions per ton of primary aluminum ingot production in China, with the LC GHG emissions as high as 1.5−3.5 times that of developed economies. The LC PE consumption and GHG emiss... [more]
Decision-Making Model of Mechanical Components in a Lean−Green Manufacturing System Based on Carbon Benefit and Its Application
Xiaoyong Zhu, Yongmao Xiao, Gongwei Xiao
February 21, 2023 (v1)
Subject: Environment
Keywords: carbon benefit, carbon efficiency, carbon emission, lean–green, process decision-making
The key to achieving low-carbon manufacturing is to effectively reduce the carbon emissions of production systems and improve carbon benefits. The use of lean and green tools aids in measuring the added value of products, and increases the efficiency and sustainability of production systems. To address this problem and verify that the synergetic relationship between lean and green innovation increases the efficiency and sustainability in production systems, a new low-carbon manufacturing evaluation indicator—carbon benefit—in lean manufacturing systems was discussed. A low-carbon decision-making model of multiple processes aiming at carbon benefit maximization, as well as the dynamic characteristics of carbon benefit and sustainable process improvements in a lean production system, was established. A case study of a certain satellite dish parts manufacturing line was introduced to analyze and verify the feasibility of the proposed model. After improvement, the processing time of unit p... [more]
Challenges and Construction Applications of Solid Waste Management in Middle East Arab Countries
Osama Ibrahim, Ghassan Al-Kindi, Mohsin Usman Qureshi, Salma Al Maghawry
February 21, 2023 (v1)
Subject: Environment
Keywords: Arab countries, construction applications, construction solid waste, health hazards, MENA, municipal solid waste management, Renewable and Sustainable Energy
Over the past few decades, solid waste production, specifically construction waste, in Middle Eastern Arab countries has dramatically increased. This is characterized by several factors, including rapid urbanization, common food wasting habits, diverse culture, lack of proper planning of solid waste processes, insufficient equipment, as well as lack of proper funding. The exponential growth in solid waste generation rates has led to hazards to health and the environment, causing issues related to air and water pollution under the already increasing pressure of climate change. In this review, we analyze the current solid waste challenges in 13 Arab countries, common diseases, and actual projects applied. The selection of Arab countries was mainly based on the countries with the highest population as well as the availability of data in the field of study. This review also highlights the efforts of the Arab governments that implemented several pilot projects that are not sustainable or ef... [more]
Basic Conceptual Structure for the Assessment of the Natural Services Provided by Hydroelectricity Projects
Enrique Rosales-Asensio, Iker de Loma-Osorio, Noemí González-Cobos, Antonio Pulido-Alonso, David Borge-Diez
February 21, 2023 (v1)
Subject: Environment
Keywords: conceptual structure, ecosystem valuation, hydroelectricity projects, natural services
This paper presents and defines a method for standardizing ecosystem services in the context of hydropower projects and demonstrates its applicability through the Folsom hydropower plant in California. In particular, this paper uses the Final Ecosystem Goods and Services Classification System (FEGS-CS) to provide a structured framework for identifying ecosystems, the potential services they provide, and their beneficiaries. In this paper, the benefit transfer technique is used for estimating non-market values for new policy contexts. The total value of this case study is about USD 169 million per year for the Folsom hydropower plant in California. The advantage of the proposed framework lies in its ability to be imported and applied to any other hydropower facility, and it can be extensively used both for new and existing power plants.
Biodegradation of Alachlor by a Newly Isolated Bacterium: Degradation Pathway and Product Analysis
Hyosun Lee, Dong-Uk Kim
February 21, 2023 (v1)
Subject: Environment
Keywords: Acinetobacter sp. GC-A6, alachlor, biodegradation, N-(2,6-diethylphenyl) formamide
Alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl]acetamide] is a chloroacetanilide herbicide and has been widely used as a selective pre-emergent and post-emergent herbicide to control weeds and grass. Due to its wide usage, direct application on the ground, high solubility in water, and moderate persistence, alachlor and its metabolites have been detected in various environments. Therefore, there is an increasing concern about the environmental fate of alachlor and its metabolites. Microbial biodegradation is a main method of removal of alachlor in the natural environment. In this study, we isolated new alachlor degrading bacterium and proposed a novel alachlor-degrading pathway. The alachlor-degrading bacterial strain, GC-A6, was identified as Acinetobacter sp. using 16S rRNA gene sequence analysis. Acinetobacter sp. GC-A6 utilized alachlor as its sole carbon source and degraded 100 mg L−1 of alachlor within 48 h, which was the highest alachlor degradation efficiency. The de... [more]
Using Artificial Neural Network Application in Modeling the Mechanical Properties of Loading Position and Storage Duration of Pear Fruit
Elçin Yeşiloğlu Cevher, Demet Yıldırım
February 21, 2023 (v1)
Subject: Environment
Keywords: Artificial Intelligence, environmental condition, rupture energy, soft computing technique
In the study, rupture energy values of Deveci and Abate Fetel pear fruits were predicted using artificial neural network (ANN). This research aimed to develop a simple, accurate, rapid, and economic model for harvest/post-harvest loss of efficiently predicting rupture energy values of Deveci and Abate Fetel pear fruits. The breaking energy of the pears was examined in terms of storage time and loading position. The experiments were carried out in two stages, with samples kept in cold storage immediately after harvest and 30 days later. Rupture energy values were estimated using four different single and multi-layer ANN models. Four different model results obtained using Levenberg−Marquardt, Scaled Conjugate Gradient, and resilient backpropagation training algorithms were compared with the calculated values. Statistical parameters such as R2, RMSE, MAE, and MSE were used to evaluate the performance of the methods. The best-performing model was obtained in network structure 5-1 that used... [more]
Synthesis of Integrated Flower Waste Biorefinery: Multi-Objective Optimisation with Economic and Environmental Consideration
Emily Hau Yan Chong, Viknesh Andiappan, Lik Yin Ng, Parimala Shivaprasad, Denny K. S. Ng
February 21, 2023 (v1)
Subject: Environment
Keywords: flower waste, integrated biorefinery, mathematical optimisation, value-added product, waste valorisation
The improper disposal of flower waste from cultural activities is one of the main challenges in certain countries such as India. If the flower waste is not managed properly, it causes a number of environmental issues. Therefore, various technologies have been developed to transform flower waste into value-added products. To integrate multiple technologies holistically to maximise the energy and material recovery, an integrated flower-waste biorefinery is required. Since there are a wide range of technologies available that can convert the waste into multiple products, there is a need to develop a systematic approach to evaluate all the technologies. This research proposes a systematic approach to synthesise an integrated flower-waste biorefinery based on different optimisation objectives, e.g., maximum economic performance and minimum environmental impact. Due to the conflicting nature between the two objectives, a fuzzy optimisation approach has been adapted to synthesise a sustainabl... [more]
Thermal Swing Reduction-Oxidation of Me(Ba, Ca, or Mg)SrCoCu Perovskites for Oxygen Separation from Air
Julius Motuzas, Shaomin Liu, João C. Diniz da Costa
February 21, 2023 (v1)
Subject: Environment
Keywords: Carbon Capture, oxyfuel, oxygen, perovskite
The climate change impact associated with greenhouse gas emissions is a major global concern. This work investigates perovskite compounds for oxygen separation from air to supply oxygen to oxyfuel energy systems to abate these significant environmental impacts. The perovskites studied were Me0.5Sr0.5Co0.8Cu0.2O3−δ (MeSCC) where the A-site substitution was carried out by four different cations (Me = Ca, Mg, Sr, or Ba). SEM analysis showed the formation of small particle (<1 µm) aggregates with varying morphological features. XRD analysis confirmed that all compounds were perovskites with a hexagonal phase. Under reduction and oxidation reactions (redox), Ba and Ca substitutions resulted in the highest and lowest oxygen release, respectively. In terms of real application for oxygen separation from air, Ba substitution as BaSCC proved to be preferable due to short temperature cycles for the uptake and release of oxygen of 134 °C, contrary to Ca substitution with long and undesirable te... [more]
Data-Driven Evaluation of the Synergetic Development of Regional Carbon Emissions in the Yangtze River Delta
Yuxia Guo, Fagang Hu, Jun Xie, Conghu Liu, Yaliu Yang, Heping Ding, Xue Wu
February 21, 2023 (v1)
Subject: Environment
Keywords: carbon emissions, coordination degree, data-driven, sustainable development
Evaluating the degree of coordination among regional carbon emission systems is key to achieving an earlier carbon peak and carbon neutrality. However, quantifying the co-evolution of carbon emissions among regions is challenging. Therefore, we propose a data-driven method for evaluating the synergetic development of the regional carbon emission composite system. First, the proposed method employs relevant data to calculate the carbon emissions and carbon emission intensity of each subsystem within the region to describe the temporal trends. The inverse entropy weight method is then used to assign weight to each order parameter of the subsystem for data processing. Then, we perform synergetic development assessment of the composite system to measure the order degree of each subsystem, the degree of synergy among subsystems, and the overall synergetic degree of the temporal evolution of carbon emissions between regions. Finally, the evaluation results can be used to suggest measures for... [more]
Plant Extraction in Water: Towards Highly Efficient Industrial Applications
Lorenzo Gallina, Christian Cravotto, Giorgio Capaldi, Giorgio Grillo, Giancarlo Cravotto
February 21, 2023 (v1)
Subject: Environment
Keywords: enabling technologies, extraction in water, hydrodynamic cavitation, microwaves, subcritical water, ultrasound
Since the beginning of this century, the world has experienced a growing need for enabling techniques and more environmentally friendly protocols that can facilitate more rational industrial production. Scientists are faced with the major challenges of global warming and safeguarding water and food quality. Organic solvents are still widely used and seem to be hard to replace, despite their enormous environmental and toxicological impact. The development of water-based strategies for the extraction of primary and secondary metabolites from plants on a laboratory scale is well documented, with several intensified processes being able to maximize the extraction power of water. Technologies, such as ultrasound, hydrodynamic cavitation, microwaves and pressurized reactors that achieve subcritical water conditions can dramatically increase extraction rates and yields. In addition, significant synergistic effects have been observed when using combined techniques. Due to the limited penetrati... [more]
A Systematic Investigation on the Damage Characteristics of Fish in Axial Flow Pumps
Lufeng Zhu, Fan Zhang, Xiaotao Shi, Kofi Asamoah Adu-Poku, Jinfeng Zhang, Shouqi Yuan
February 21, 2023 (v1)
Subject: Environment
Keywords: axial flow pump, damage, fish, internal flow
An axial flow pump is a kind of high-specific revolution vane pump that has the characteristics of large flow, low head, and high efficiency. Due to its unique properties, it is widely used in large water diversion projects, such as the South-to-North Water Diversion Project. However, during the operation of the pump, some fish enter the axial flow pump together with the water flow through the screen before the entrance of the pump station. Consequently, some fish are inevitably damaged or even die in the process of traversing through the pump. Meanwhile, the decay of dead fish directly affects the quality of water, hence, posing serious ecological pollution and destabilizing the ecological balance. Therefore, understanding the dynamics of axial flow pumps in relation to fish species in water bodies for biodiversity and ecosystem services remain vital for nature conservation. In this paper, the impact of damage of the model pump on fish is exhaustively investigated according to the the... [more]
Investigation of Flow-Induced Noise Characteristics in the Oblique Flow Pump
Zhengxuan Xu, Feifei Zhao, Jia Liu, Fan Zhang, Jinfeng Zhang, Mengbin Song
February 21, 2023 (v1)
Subject: Environment
Keywords: flow separation, flow-induced noise, oblique flow pump, vortex
An oblique flow pump is widely used in farmland irrigation and drainage, water transfer projects, thermal power generation, and other fields. However, unstable flow factors in the oblique flow pump easily lead to pump vibration and noise. To improve the stability of pump operation and optimize the operating environment, it is necessary to study the flow-induced noise characteristics of oblique flow pumps. In this paper, CFD and noise simulation software are used to calculate the flow field and sound field of the oblique flow pump. The internal flow characteristics and flow-induced noise characteristics of the oblique flow pump were studied. The results show that when the flow rate of the oblique flow pump deviates from the optimal operating point, especially in the small flow rate, due to the phenomena of backflow and flow separation, more high-energy vortices are produced in the flow channel, and the vortices are distributed in a wide area, which will cause greater flow-induced noise.... [more]
The Difference of Lead Accumulation and Transport in Different Ecotypes of Miscanthus floridulus
Jianqiao Qin, Huarong Zhao, Hao Liu, Min Dai, Peng Zhao, Xi Chen, Xiange Wu
February 21, 2023 (v1)
Subject: Environment
Keywords: accumulation and translocation, ecotype, lead, miscanthus floridulus
is a plant with a high biomass and heavy metal tolerance, which is a good candidate for phytoremediation. Pot experiments were conducted to compare the growth response, Pb enrichment ability, and the effect on Pb speciation of two ecotypes of M. floridulus from the Dabaoshan Mining Area and the non-mining area of Boluo County, Huizhou, in soils with different Pb contents. The results showed that two ecotypes of M. floridulus had different growth responses to Pb concentrations in soil. Under a low concentration of Pb (100 mg·kg−1) treatment, the aboveground biomass of the non-mining area plant ecotype was significantly affected, while the plants with the mining area ecotype were not significantly affected. When the concentration of Pb increased, the aboveground biomass of the non-mining ecotype was 30.2−41.1% of the control, while that of the mining ecotype was 57.8−65.0% of the control. The root biomass of the non-mining ecotype decreased with the increase of treatment concentration, a... [more]
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