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Records with Subject: Environment
Showing records 3232 to 3256 of 3422. [First] Page: 1 127 128 129 130 131 132 133 134 135 Last
Assessing the Environmental and Economic Sustainability of Functional Food Ingredient Production Process
Anushree Priyadarshini, Brijesh K. Tiwari, Gaurav Rajauria
February 21, 2023 (v1)
Subject: Environment
Keywords: bioactive, cost of manufacturing, emerging technology, food processing, nutraceutical, production process, TDABC, ultrasound-assisted extraction
Development and application of novel technologies in food processing is vital for ensuring the availability of adequate, safe, and convenient food with the desired quality and functional properties. Environmental and economic sustainability of technologies is essential prior to their application in the food processing sector. The objective of this research is to determine the environmental and economic feasibility of ultrasound-assisted extraction (UAE) for recovering functional food ingredients from seaweed. Experimental data is used to conduct a life cycle assessment (LCA) to investigate the environmental performance with a functional unit (FU) of obtaining 1 g of extracted polyphenols, measured as gallic acid equivalents (mg GAE)/g seaweed. A life cycle impact assessment is performed with ReCiPe 2016 at midpoint. The cost of manufacturing (COM) of phenolic-rich extracts (as functional ingredient, bioactive, or nutraceutical) is estimated using time-driven activity-based costing (TDA... [more]
Health Effect of N-Nitroso Diethylamine in Treated Water on Gut Microbiota Using a Simulated Human Intestinal Microbiota System
Dedong Wang, Yanting Jiang, Di Wu, Shuxue Li, Zhendong Wu, Yi Zhong, Lin Zhang, Chongshan Guo, Xiaotong Li, Lili Sun, Qin Li, Jinhua Zhou, Weiyun He
February 21, 2023 (v1)
Subject: Environment
Keywords: chlorination disinfection by-products, gut microbiota, health effect, N-nitroso diethylamine, treated water
Chlorination disinfection byproducts (CDBPs) can exert adverse human health effects. Many toxicology-based studies confirmed the health hazards of CDBPs, but little research has been done on gut microbiome. We explored the effect of CDBPs on intestinal microbiota in the Simulator of the Human Intestinal Microbial Ecosystem (SHIME). The results showed that CDBPs slightly inhibited the production of short-chain fatty acids, and the abundance of Actinobacteria decreased in the transverse colon and descending colon. The abundance of Proteobacteria increased in the ascending colon and descending colon, while it decreased in the transverse colon. The abundance of Firmicutes decreased in both the ascending colon and descending colon. In particular, the abundance of Lachnospiraceae members, Bilophila, Oscillospira, Parabacteroides, Desulfovibrio, and Roseburia increased in the ascending colon, while the abundance of Sutterella, Bacteroides, Escherichia, Phascolarctobacterium, Clostridium, Citr... [more]
Evaluating the Energy Efficiency and Environmental Impact of COVID-19 Vaccines Coolers through New Optimization Indexes: Comparison between Refrigeration Systems Using HFC or Natural Refrigerants
Alexandre F. Santos, Pedro D. Gaspar, Heraldo J. L. de Souza
February 21, 2023 (v1)
Subject: Environment
Keywords: COVID-19, energy consumption, environmental impact, EUED, HFC, propane, SARS CoV-2, TEWI, vaccines
COVID-19 vaccines are used worldwide to promote immunity and, in that sense, vaccination is a step forward toward ending the pandemic. Nevertheless, current vaccines must be ultra-cold or cold-stored. Vaccine coolers’ energy demand and greenhouse gas emissions lead to a significant environmental impact. This article predicts the environmental and energy impacts of some COVID-19 vaccines: Moderna, Janssen, CoronaVac, Pfizer, AstraZeneca−Oxford−Covishield, and Sputnik V, in terms of carbon dioxide emissions using a new approach for the TEWI (Total Equivalent Warming Impact) methodology, with several options of refrigerants from halogenated to natural fluids such as propane, which is natural gas with low GWP (global warming potential). Through the application of new optimization indexes, it is concluded that the evaporation temperature of the refrigerant gas has a great influence on the sizing of the coolers. For example, for the same number of vaccines, the thermal load of Pfizer is more... [more]
Environmental Benefits of Air Emission Reduction in the Waste Tire Management Practice
Jasmina Ćetković, Slobodan Lakić, Miloš Žarković, Radoje Vujadinović, Miloš Knežević, Angelina Živković, Jelena Cvijović
February 21, 2023 (v1)
Subject: Environment
Keywords: air emission, cost–benefit analysis, savings in the cost of environmental pollution, socio-economic benefits, waste tire management
Montenegro faces serious challenges in terms of waste tire management. The main goal of our paper is to consider the financial and economic justification of the implementation of the first phase of the project of collection, takeover and transport, sorting, and storage of waste tires from the three municipalities in Montenegro. The financial feasibility analysis pointed out the need to organize the second phase of the project and the production of commercially usable and energy efficient products. That phase would lead to the desired commercial effects and will probably ensure the financial sustainability of the project. The economic feasibility analysis of the project included an assessment of the socio-economic benefits from the emission reduction of the first group of pollutants (PM, SOX, NOX, VOC, CO) as a consequence of the waste tires’ destruction, predominantly by combusting them. Unit values of pollution costs by types of gases, adjusted for Montenegro, were defined in the inte... [more]
Investigating the Enhancement in Biogas Production by Hydrothermal Carbonization of Organic Solid Waste and Digestate in an Inter-Stage Treatment Configuration
Roberta Ferrentino, Michela Langone, Davide Mattioli, Luca Fiori, Gianni Andreottola
February 21, 2023 (v1)
Subject: Environment
Keywords: anaerobic digestion, biogas production, dewaterability, digestate, hydrothermal carbonization, organic fraction of municipal solid waste, sludge reduction
In recent years, sewage sludge (SS) and bio-waste management have attracted increasing environmental attention. In this study, hydrothermal carbonization (HTC) technology is investigated in the framework of a co-treatment of sewage sludge digestate (SSD) and an organic fraction of municipal solid waste (OW). The proposed configuration integrates HTC with anaerobic digestion (AD) in an inter-stage configuration (AD1 + HTC + AD2). The effects of different percentages of OW added to SSD in the HTC treatment are evaluated in terms of characteristics and methane yield of the produced HTC liquor (HTCL) and HTC slurry (i.e., the mixture hydrochar-HTCL), as well as dewaterability of the HTC slurry. Results show that, with the increase in the percentage of OW in the OW-SSD mixture fed to the HTC process, production of biogas and biomethane of both HTC slurry and HTCL increases. The highest biogas production is achieved when a mixture consisting of half SSD and half OW is used, reaching 160 ± 10... [more]
Hydrometallurgical Recovery of Iron, Nickel, and Chromium from Stainless Steel Sludge with Emphasis on Solvent Extraction and Chemical Precipitation
Wei-Sheng Chen, Yu-Chi Chen, Cheng-Han Lee
February 21, 2023 (v1)
Subject: Environment
Keywords: chemical precipitation, D2EHPA, hydrometallurgy, solvent extraction, stainless steel sludge
Stainless steel has a variety of applications nowadays because of its mechanical strength and corrosion resistance. The large-scale machinery made up of stainless steel has an outstanding performance and endurance for manufacturing industries. However, stainless steel scraps accumulate with a lubricant to form sludge during the operation. To reduce the environmental hazards caused by sludge, this research attempts to construct a hydrometallurgical process to recover iron, nickel, and chromium from the sludge. The experiments could be divided into four parts. First, calcination was adopted to remove the oil and water content. The factors that have impacts on the leaching efficiency, such as the type of acid and the calcination temperature, were investigated in the second part. It was optimal that the sludge was calcined at 300 ℃ for 8 h and leached by 4 mol/L HCl. The results revealed that the leaching percentages of iron, nickel, and chromium were 97.6%, 98.1%, and 95.7%, respectively.... [more]
Thermodynamic Optimization of Aircraft Environmental Control System Using Modified Genetic Algorithm
Qihang Liu, Laihe Zhuang, Jie Wen, Bensi Dong, Zhiwei Liu
February 21, 2023 (v1)
Subject: Environment
Keywords: aircraft, energy conservation, environmental control system, fuel energy consumption rate, Genetic Algorithm, thermo-economics optimization
This paper presents an optimization method for the civil aircraft environmental control system (ECS) mainly involving two airstreams: the ram airstream for cooling and the bleed airstream for supplying the cabin. The minimum total fuel energy consumption rate (FECR), defined as the weighted sum of the shaft power extraction and propulsive power loss, is obtained under the precondition of the constant outputs in the cooling capacity and outlet pressure. A modified genetic algorithm (GA) is proposed to acquire the optimal values of the heat transfer areas, temperature ratio of bleed air, mass flow rate of ram air, and pressure ratios of the turbine, compressor, and fan. The statistical results show that the multipoint crossover and continuity improvement implemented in the modified GA improve convergence and distribution performance. The probability of reaching a satisfactory result using modified GA is 62.4% higher than standard GA. Due to the decrease of inlet parameters of bleed air a... [more]
Transfer of Potentially Toxic Elements in the Soil-Plant System in Magnesite Mining and Processing Areas
Lenka Štofejová, Juraj Fazekaš, Danica Fazekašová
February 21, 2023 (v1)
Subject: Environment
Keywords: contamination, environmental indices, phytoremediation
Mining activities, ore concentrations, and transport processes generate large amounts of pollutants, including hazardous elements, which are released into the environment. This work presents the results of experimental research aimed at evaluating the environmental risks of soil and plant contamination in two magnesite mining and processing areas in the Slovak Republic, and assesses the phytoremediation potential of dominant plant species. Eleven potentially toxic elements in the soil were investigated using X-ray fluorescence spectrometry (Cd, Pb, Cr, Zn, Cu, As, Ni, Mn, Mg, Fe) and atomic absorption spectrometry (Hg). In plants, potentially toxic elements were investigated using inductively coupled plasma mass spectrometry (Cu, As, Cd, Pb) and inductively coupled plasma atomic emission spectrometry (Cr, Zn, Mn, Mg). Selected soil parameters (pH, redox potential, and soil organic matter) were also investigated. Soil contamination was evaluated using environmental indices (geoaccumulat... [more]
Environmental Aspects of the Combined Cooling, Heating, and Power (CCHP) Systems: A Review
Mohsen Salimi, Morteza Hosseinpour, Shabnam Mansouri, Tohid N.Borhani
February 21, 2023 (v1)
Subject: Environment
Keywords: carbon footprint, CCHP, LCA, renewables, water footprint
Expanding cities means increasing the need for energy in the residential sector. The supply of this energy must be in environmentally friendly ways; one method of meeting demand in the residential sector is the use of combined cooling, heating, and power (CCHP) systems. The current review paper shows that due to the high cost of gas and electricity, CCHP can be used in various sectors, such as hospitals and airports, to reduce energy consumption with lower environmental impacts by using renewable energy systems as the main driver. While CCHP systems are not feasible in tropical regions with high cooling demand, a solar hybrid system is a superior candidate for regions with sufficient radiation. CCHP can also be used in sectors such as wastewater treatment units, desalination systems, and hydrogen production units to improve performance and increase productivity. The carbon and water footprints of CCHP systems are discussed in detail. The main drivers for reducing carbon and water footp... [more]
Synthetic Biology: A New Era in Hydrocarbon Bioremediation
Valentina Jiménez-Díaz, Aura Marina Pedroza-Rodríguez, Oswaldo Ramos-Monroy, Laura C. Castillo-Carvajal
February 21, 2023 (v1)
Subject: Environment
Keywords: bioremediation, biosensors, consortium, genetically engineered microorganisms, hydrocarbons, synthetic biology
Crude oil is a viscous dark liquid resource composed by a mix of hydrocarbons which, after refining, is used for the elaboration of distinct products. A major concern is that many petroleum components are highly toxic due to their teratogenic, hemotoxic, and carcinogenic effects, becoming an environmental concern on a global scale, which must be solved through innovative, efficient, and sustainable techniques. One of the most widely used procedures to totally degrade contaminants are biological methods such as bioremediation. Synthetic biology is a scientific field based on biology and engineering principles, with the purpose of redesigning and restructuring microorganisms to optimize or create new biological systems with enhanced features. The use of this discipline offers improvement of bioremediation processes. This article will review some of the techniques that use synthetic biology as a platform to be used in the area of hydrocarbon bioremediation.
Culturing Important Plants for Sweet Secondary Products under Consideration of Environmentally Friendly Aspects
Matthias Preusche, Andreas Ulbrich, Margot Schulz
February 21, 2023 (v1)
Subject: Environment
Keywords: culture systems, Glycyrrhiza glabra, glycyrrhizin, Hydrangea macrophylla, mogrol, phyllodulcin, Rubus suavissimus, Siraitia grosvenorii, Stevia rebaudiana, steviol
Some sweet tasting plant secondary metabolites are non-caloric or low nutritive compounds that have traditional use in food formulations. This mini-review focuses on conventional and advanced cultivation regimes of plants that accumulate sweet tasting or sweet taste modulating secondary metabolites of potential economic importance, in particular mogrosides (Siraitia grosvenorii), phyllodulcin (Hydrangea macrophylla), glycyrrhizin (Glycyrrhiza glabra), steviol glycosides (Stevia grosvenorii), and rubusoside (Rubus suavissimus). Consequential obstacles during the cultivation of Hydrangea macrophylla cultivars outside their natural habitat in a protected cultivation environment are addressed. Culturing at non-habitat locations facilitates short transportation routes of plant material for processing, which can be a key to an economically and environmentally compatible usage. The biosynthetic pathways, as far as known, are shortly mentioned. The proved or hypothetical degradation pathways o... [more]
Valuation of Climate Performance of a Low-Tech Greenhouse in Costa Rica
Adriana Rojas-Rishor, Jorge Flores-Velazquez, Edwin Villagran, Cruz Ernesto Aguilar-Rodríguez
February 21, 2023 (v1)
Subject: Environment
Keywords: landsloping greenhouse, relative humidity, thermal difference, tomato and pepper crop
The expansion of protected agriculture has technological, climatic, and topographic limitations. The agricultural regions of Costa Rica use the greenhouse concept and adapt it to its conditions. The objective of this work was to describe the variation in temperature and humidity in a greenhouse ventilated passively and on land with a more than 45% slope. To evaluate the environment inside the greenhouse, temperature and humidity variations were measured with a weather station installed outside of the greenhouse to measure the external environment. Inside the greenhouse, 17 sensors were placed to measure the temperature (T) and relative humidity (RH). During data recording inside the greenhouse, tomato crops were in the fruit formation stage, and pepper was less than one week old. Six scenarios were tested to determine the air temperature and humidity dynamic under different climatic conditions. An evaluation of the greenhouse environment was carried out employing an analysis of varianc... [more]
Bearing Fault Feature Extraction Based on Adaptive OMP and Improved K-SVD
Lijun Wang, Xiangyang Li, Da Xu, Shijuan Ai, Chaoge Wang, Changxin Chen
February 21, 2023 (v1)
Subject: Environment
Keywords: feature extraction, K-SVD algorithm, OMP algorithm, the fault feature
The condition of the bearing is closely related to the condition and remaining life of the rotating machine. Targeting the problem of the large number of harmonic signals and noise signals during the operation of rolling bearings, and given that it is difficult to identify the fault in time, an adaptive orthogonal matching pursuit algorithm (OMP) and an improved K-singular value decomposition (K-SVD) for bearing fault feature extraction are proposed. An adaptive OMP algorithm is applied, which uses the Fourier dictionary to improve the solution method of the OMP algorithm so that it can separate the harmonic components in the signal faster and more accurately. At the same time, the stopping criterion of the adaptive sparsity is improved in dictionary learning. There is no need to manually set the sparsity in the algorithm initialization process, which avoids the problem of algorithm performance degradation due to improper sparsity settings, and improves the efficiency of the K-SVD algo... [more]
The Effect of Spray Parameters on the Survival of Bacteriophages
Kirsten Wessels, Diane Rip, Pieter Gouws
February 21, 2023 (v1)
Subject: Environment
Keywords: bacteriophage, nozzle, pressure, Salmonella, spray, survival
There have been numerous studies highlighting the efficacy of various bacteriophages (phages) and phage cocktails in the reduction of pathogens in food. Despite approval from legislative bodies permitting phage use in food processing environments, applied via spray or dip, there is still no information on which spray parameters should be used for successful implementation. The study here investigates phage survival diluted to 1% in distilled water (dH2O) and prepared bottled water (PBW), followed by a subsequent spray application through a fixed nozzle (530 μm) and strainer size (74 × 74 μm), with pressures of 3, 5, and 6 Bar. The survival of the phage was determined through sampling the outputs of the spray system and performing double agar overlay plaque assays. PBW decreased the phage concentration (p = 0.18) more than the dH2O (p = 0.73) prior to spray application. It was found that the PBW phage solution was less affected by the various spray parameters (p = 0.045) than the dH2O (... [more]
Biocontrol Methods in Avoidance and Downsizing of Mycotoxin Contamination of Food Crops
Manuela Zadravec, Ksenija Markov, Tina Lešić, Jadranka Frece, Danijela Petrović, Jelka Pleadin
February 21, 2023 (v1)
Subject: Environment
Keywords: biocontrol, cereals, environmentally friendly, molds, mycotoxins, seeds
By increasing the resistance of seeds against abiotic and biotic stress, the possibility of cereal mold contamination and hence the occurrence of secondary mold metabolites mycotoxins decreases. The use of biological methods of seed treatment represents a complementary strategy, which can be implemented as an environmental-friendlier approach to increase the agricultural sustainability. Whereas the use of resistant cultivars helps to reduce mold growth and mycotoxin contamination at the very beginning of the production chain, biological detoxification of cereals provides additional weapons against fungal pathogens in the later stage. Most efficient techniques can be selected and combined on an industrial scale to reduce losses and boost crop yields and agriculture sustainability, increasing at the same time food and feed safety. This paper strives to emphasize the possibility of implementation of biocontrol methods in the production of resistant seeds and the prevention and reduction i... [more]
Emerging Pollutants in Wastewater, Advanced Oxidation Processes as an Alternative Treatment and Perspectives
Alexis Rubén Bracamontes-Ruelas, Luis Alberto Ordaz-Díaz, Ana María Bailón-Salas, Julio César Ríos-Saucedo, Yolanda Reyes-Vidal, Liliana Reynoso-Cuevas
February 21, 2023 (v1)
Subject: Environment
Keywords: advanced oxidation processes (AOPs), biological processes, emerging pollutants or contaminants, mineralization, SARS-CoV-2
Emerging pollutants are present in wastewaters treated by conventional processes. Due to water cycle interactions, these contaminants have been reported in groundwater, surface water, and drinking waters. Since conventional processes cannot guarantee their removal or biotransformation, it is necessary to study processes that comply with complete elimination. The current literature review was conducted to describe and provide an overview of the available information about the most significant groups of emerging pollutants that could potentially be found in the wastewater and the environment. In addition, it describes the main entry and distribution pathways of emerging contaminants into the environment through the water and wastewater cycle, as well as some of the potential effects they may cause to flora, fauna, and humans. Relevant information on the SARS-CoV-2 virus and its potential spread through wastewater is included. Furthermore, it also outlines some of the Advanced Oxidation P... [more]
Molecular Analysis of Soil Bacterial Community Structures for Environmental Risk Assessment with Varieties of Genetically Modified Soybean and Hot Pepper
Hyosun Lee, Jeongpyo Yoon, Dong-Uk Kim
February 21, 2023 (v1)
Subject: Environment
Keywords: genetically modified soybean and hot pepper, NGS, persistence of transgenes, real-time PCR-DGGE, soil microbial community structures
With the advance in gene technology, genetically modified (GM) crops have increased in recent years. GM crops offer us various benefits. However, there are potential risks of GM crops for the environment. In this study, the impacts of transgenic plants on soil microbial community structures were assessed. Two varieties of soybean (Glycine max L.) and hot pepper (Capsicum annuum L.), which introduced the herbicide-resistant gene, bar, were used in this study. The effects of GM crops on soil microbial community structures were investigated using a cultural method, the denaturing gradient gel electrophoresis (DGGE) procedure, and 16S rRNA gene sequencing on the Illumina platform. Additionally, the persistence of transgenes was monitored using a quantitative real-time PCR procedure. The cultural method, DGGE analysis, and the amplicon-based community profile indicated that soil microbial communities were not significantly different between GM and non-GM lines. The level of the bar gene in... [more]
Nitric Oxide Generation in N2-Diluted H2−N2O Flames: A Computational Study
Domnina Razus, Venera Giurcan, Codina Movileanu, Maria Mitu
February 21, 2023 (v1)
Subject: Environment
Keywords: combustion, dilution, flames, Hydrogen, nitric oxide, nitrous oxide
A computational study was conducted on the addition of nitrogen (0−60 vol%) to stoichiometric hydrogen−nitrous oxide flames at various initial pressures (1−10 bar) and temperatures (300−500 K), with a special emphasis on NO, which is a major pollutant that is generated by these flames. The detailed kinetic modeling of H2−N2O−N2 flames, which was performed using the GRI 3.0 mechanism, produced the structure of the H2−N2O−N2 flames for the temperature and mass fraction profiles of 53 species, which participated in 325 elementary reactions. The NO profiles that were computed by the detailed kinetic modeling followed the trend of experimental NO profiles that have been reported in the literature for laminar premixed flames at sub-atmospheric pressures. For the examined H2−N2O−N2 flames, an increase in initial pressure resulted in a significant reduction in the NO mass fraction of the burned gas. The increase in initial temperature was also accompanied by an increase in the mass fractions o... [more]
Depositional Environment Changes during the Cenozoic in the Northeastern Margin of the Qinghai−Tibet Plateau
Yetong Wang, Guoqiang Sun, Shuncun Zhang, Irene Cantarero, David Cruset, Vinyet Baqués, Hui Guo, Shangshang Bo, Anna Travé
February 21, 2023 (v1)
Subject: Environment
Keywords: Cenozoic climate, isotope analysis, Qaidam Basin, Qinghai–Tibet Plateau, trace elements
The uplift of the Tibetan Plateau (TP) during the late Cenozoic is thought to be one of the crucial factors controlling the Asian climate. However, the complex interaction between tectonics and climate change remains unclear. The carbon and oxygen isotopes and elementary geochemistry of rocks from the early Eocene Lulehe Formation to the Miocene Youshashan Formation in the northern margin of Qaidam Basin, shows important variations in the Rb/Sr, MgO/CaO, Sr/Cu, and V/Cr ratios, together with CMI and CIA, which are interpreted as reflecting relevant regional climate and environmental changes. Combining the above mentioned parameters, we reconstructed the evolution of the sedimentary environment in the Qaidam Basin. The climate is roughly divided into four stages: (1) warm and humid; (2) cold and dry; (3) alternations of cold and dry with warm and humid; and (4) cold and arid. At the same time, there are also minor short-term changes of dry, wet, cold, and warm in each stage. The early E... [more]
Exploring Key Decisive Factors in Manufacturing Strategies in the Adoption of Industry 4.0 by Using the Fuzzy DEMATEL Method
Fawaz M. Abdullah, Abdulrahman M. Al-Ahmari, Saqib Anwar
February 21, 2023 (v1)
Subject: Environment
Keywords: competitive capabilities, fuzzy DEMATEL method, industry 4.0 technologies, manufacturing strategies, smart manufacturing
Globalization has created a highly competitive and diverse market, an uncertain and risky business environment, and changing customer expectations. An effective manufacturing strategy reduces complexity and provides organizations with a well-organized manufacturing structure. However, existing research on manufacturing strategies appears scattered, lacking systematic understanding and finding no causal relationship between manufacturing strategies’ outputs (MSOs) and their importance. Therefore, this study is a pioneer in identifying the influential factors of MSOs in the adoption of Industry 4.0 (I4.0) technologies utilizing the decision-making trial and evaluation laboratory (DEMATEL) approach. This method is considered an effective method for identifying the cause-effect relationship of complex problems. It evaluates interdependent relationships among MSO factors from the perspective of academic and industry experts. Identifying cause and effect factors leads to increasing the marke... [more]
Special Issue on “Soil and Sustainable Development: Challenges and Solutions”
David Fernández-Calviño, Manuel Arias-Estévez, Ruth Pereira, Joana Lourenço
February 21, 2023 (v1)
Subject: Environment
Food production is increasing year by year, with modern agriculture occupying high-fertility soils [...]
Estimation Parameters of Soil Solute Transport Processes by Using the Electric Resistivity Method
Debao Lu, Yinfeng Xia, Nan Geng, Hui Wang, Jinlin Qian, Cundong Xu
February 21, 2023 (v1)
Subject: Environment
Keywords: breakthrough curves, ERT, MIM, preferential solute transport
Preferential solute transport is a common phenomenon in soil, and it is of great significance to accurately describe the mechanism of pollutant transport and water and soil environmental governance. However, the description of preferential solutes still relies on applying solute breakthrough curves for model parameters fitting. At present, most of the solute breakthrough curves are obtained indoors, and with some limitations. Therefore, this study established a method for securing solute breakthrough curves based on the electrical resistivity method. The research results show that the change in soil concentration during the tracer infiltration process can be captured by establishing the fitting relationship between soil resistivity and solute concentration. Then the solute breakthrough curve can be found. Through a time moment analysis, the difference between the breakthrough curve parameters obtained by the traditional method and the resistivity method is slight; the average error is... [more]
Research and Application of Fast-Strengthening Environment-Friendly Sulfoaluminate Cement Slurry on Taguchi Method
Yue Wu, Huini Liu, Chao Tang, Yinge Zhu, Xiaoli Zhang
February 21, 2023 (v1)
Subject: Environment
Keywords: feasibility verification, strengthened by rapid grouting, sulfoaluminate cement, Taguchi grey relational analysis, waste recycling
Most of the existing research on cement slurry materials are not environmentally friendly and environmental pollution is significant. Most researchers only test its performance, but do not conduct engineering feasibility verification. In this study, the materials extracted from various wastes were used to replace part of the sulfoaluminate cement, and orthogonal experiments were designed to analyze the reaction mechanism between different materials. Finally, the optimal mixing ratio was obtained. Then, through the regression equation analysis method, digital photograph restoration technology, the finite element method and various practical engineering conditions, the feasibility of the slurry under different applicable engineering conditions was compared and analyzed. The comparison between the experimental and numerical simulation results shows that the cement slurry obtained in this study has good reliability and feasibility. It can carry out rapid grouting reinforcement. The results... [more]
Quasi-Static Flexural Behavior of Epoxy-Matrix-Reinforced Crump Rubber Composites
Kiran Shahapurkar, Khalid Alblalaihid, Venkatesh Chenrayan, Abdulaziz H. Alghtani, Vineet Tirth, Ali Algahtani, Ibrahim M. Alarifi, M. C. Kiran
February 21, 2023 (v1)
Subject: Environment
Keywords: crump rubber, epoxy, flexural testing, polymer composites, quasi-static
Waste tires have emerged as a severe environmental threat worldwide as they create a number of disposal and landfill burden issues. In the present study, environmental pollutant crump rubber derived from waste discarded tires was reinforced with epoxy resin and prepared by means of an open-mold casting method to assess its mechanical properties. The impact of crump rubber content (0, 10, 20 and 30 vol.%) on the mechanical behavior of the composites was assessed using three-point bending tests at a constant strain rate of 0.1 and 0.01 mm/s. The stress−strain profiles of the 0.01 mm/s specimens revealed higher strains to failure compared with the 0.1 mm/s tested specimens and all the specimens showed brittle failure. Irrespective of the strain rates, tests revealed a marginal increase in the strength values of the composites and a significant increase in the modulus of all the composites compared with neat epoxy specimens. The results suggest that crump rubber can be effectively used in... [more]
Transient Pressure Behavior of Volume Fracturing Horizontal Wells in Fractured Stress-Sensitive Tight Oil Reservoirs
Zhong Li, Xinjiang Yan, Min Wen, Gang Bi, Nan Ma, Zongxiao Ren
February 21, 2023 (v1)
Subject: Environment
Keywords: interfracture interference, seepage model, stress sensitive, tight oil reservoir, volume fracturing horizontal well
Tight oil reservoirs tend to contain more natural fractures, and the presence of natural fractures leads to a greater stress sensitivity in tight oil reservoirs. It is a very challenging task to model the seepage in the volume fracturing horizontal wells considering the stress-sensitive effects. Based on the Laplace transform, Perturbation transform and Stefest numerical inversion, this paper establishes a horizontal well seepage model for volume fracturing in fractured stress-sensitive tight oil reservoirs. This model allows us to analyze and study the effect of stress sensitivity, fracture interference, dual media and complex fracture network on seepage flow in tight oil reservoirs. We apply the model to delineate the seepage stages of volume fracturing horizontal wells, it can be divided into seven seepage stages I wellbore storage flow, II surface flow stage, III transition flow, IV natural fracture system proposed radial flow, V interporosity flow, VI system proposed radial flow a... [more]
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