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Can subsea shuttles be a cost-competitive solution for CO2 transport?
Simon Roussanaly, Sigmund Holm, Avinash Subramanian
February 1, 2024 (v1)
Subject: Environment
Keywords: Carbon Capture and Storage, CO2 transport, Offshore storage, subsea shuttle, Technoeconomic Analysis
Considering the role that offshore CO2 storage is expected to play in deploying carbon capture and storage, enabling cost-efficient and flexible solutions for transporting CO2 to relevant storage locations. While several pipeline and ship-based approaches have been proposed to do so, subsea shuttles are a new concept that has also been proposed in the past couple of years. The present study seeks to understand if this new approach could be cost-efficient compared to current and upcoming ship-based transport concepts.
The result shows that the shuttle concept could be cost-competitive to currently mature 15 barg-based shipping, especially if the subsea shuttle connects to a CO2 pipeline infrastructure rather than to the reservoir directly, although cost-competitiveness is achieved only for a limited range of volumes and distances. However, it is unlikely that this concept would be cost-attractive compared to the upcoming 7 barg-based shipping, and sensitivity analyses highlight that th... [more]
Hierarchical Optimization Based on Deep Reinforcement Learning for Connected Fuel Cell Hybrid Vehicles through Signalized Intersections
Hongquan Dong, Lingying Zhao, Hao Zhou, Haolin Li
January 12, 2024 (v1)
Subject: Other
Keywords: fuel economy, hierarchical joint optimization, hydrogen fuel cell hybrid vehicle, traveling efficiency, urban roads driving scenario
With the advantages of non-pollution and energy-saving, hydrogen fuel cell hybrid vehicles (HFCHVs) are regarded as one of the potential traveling ways in the future. The energy management of FCHVs has a huge energy-efficient potential which is combined with the Internet of Things (IOT) and auto-driving technologies. In this paper, a hierarchical joint optimization method that combines deep deterministic policy gradient and dynamic planning (DDPG-DP) for speed planning and energy management of the HFCHV is proposed for urban road driving scenarios. The results demonstrate that when the HFCHV is operating in driving scenario 1, the traveling efficiency of the DDPG-DP algorithm is 17.8% higher than that of the IDM-DP algorithm, and the hydrogen fuel consumption is reduced by 2.7%. In contrast, the difference in the traveling efficiency and fuel economy is small among the three algorithms in driving scenario 2, the number of idling/stop situations of the DDPG-DP algorithm is reduced compa... [more]
Response Surface Methodology (RSM) Optimization of Pulsed Electric Field (PEF) Pasteurization Process of Milk-Date Beverage
Mahmoud Younis, Khaled A. Ahmed, Isam A. Mohamed Ahmed, Hany M. Yehia, Diaeldin O. Abdelkarim, Abdulla Alhamdan, Ahmed Elfeky, Mansour N. Ibrahim
January 12, 2024 (v1)
Keywords: date powder, pulsed electric field, response surface methodology, total viable count
Milk beverage with added natural sweetener is well appreciated by consumers as a nutritious and healthy product with unique sensorial quality attributes. However, this product requires a suitable pasteurization method without significant impact on the sensorial and physicochemical quality characteristics of the product. This study optimizes the pulsed electric filed (PEF) conditions for the pasteurization of a milk-date beverage with conserved physicochemical quality properties. The effect of process variables, such as pulse off time (20, 30, and 40 μs), number of pulses (20, 50, and 80), powder ratio (10, 15, 20, and 25% w/w), storage time (2, 4, and 6 days), and storage temperature (5, 15, and 25 °C) on the responses of total viable count (TVC), color difference (∆E), pH, and total soluble solids (TSS) was evaluated using the RSM central composite design (CCD). Pulse off time, number of pulses, date powder/milk ratio (w/w), storage time, and storage temperature greatly impacted the m... [more]
Structural Optimization of Annular Thermoelectric Module Applied to Liquefied Natural Gas Cold Energy Recovery
Yulong Zhao, Hongmei Diao, Wenjie Li, Zhiwei Xuan, Qi Zhang, Yulin Wang, Minghui Ge
January 12, 2024 (v1)
Keywords: annular, cold energy, liquefied natural gas, structural optimization, thermoelectric
The gasification of liquefied natural gas (LNG) is characterized by a substantial release of cold energy, which can be utilized for power generation via thermoelectric generator (TEG). Employing a gasifier integrated with a thermoelectric generator for LNG gasification allows for the recovery of cold energy and its conversion to useful power, a process that holds significant potential for widespread application. In the study, a thermoelectric model has been developed for an annular thermoelectric module, which formed a new category of gasifier tube. The influence of the module’s structure as well as the heat transfer parameters on the thermoelectric performance was examined. The results revealed that an optimum height of the thermoelectric leg, specifically 2 mm, maximized the output power while allowing the thermoelectric conversion efficiency to reach a peak of 3.25%. Another noteworthy finding is that an increase in the central angle of the thermoelectric leg leads to a concomitant... [more]
Using Adsorption Energy Distribution for Parameter Estimation of Competitive Cofactor Coupled Enzyme Reaction
Thomas Waluga, Mirko Skiborowski
January 12, 2024 (v1)
Keywords: adsorption energy distribution, alcohol dehydrogenase, kinetic modeling
The chemical and biotechnology industries are facing new challenges in the use of renewable resources. The complex nature of these materials requires the use of advanced techniques to understand the kinetics of reactions in this context. This study presents an interdisciplinary approach to analyze cofactor coupled enzymatic two-substrate kinetics and competitive two-substrate kinetics in a fast and efficient manner. By studying the adsorption energy distribution (AED), it is possible to determine the individual parameters of the reaction kinetics. In the case of a single alcohol reaction, the AED is able to identify parameters in agreement with the literature with few experimental data points compared to classical methods. In the case of a competitive reaction, AED analysis can automatically determine the number of competing substrates, whereas traditional nonlinear regression requires prior knowledge of this information for parameter identification.
Integration of Renewable-Energy-Based Green Hydrogen into the Energy Future
Ismail Marouani, Tawfik Guesmi, Badr M. Alshammari, Khalid Alqunun, Ahmed Alzamil, Mansoor Alturki, Hsan Hadj Abdallah
January 12, 2024 (v1)
Keywords: efficiency improvement, electrolysis, green hydrogen production, leading countries in this field, net-zero gas emissions, optimization techniques, Renewable and Sustainable Energy, Renewable and Sustainable Energy, technologies used
There is a growing interest in green hydrogen, with researchers, institutions, and countries focusing on its development, efficiency improvement, and cost reduction. This paper explores the concept of green hydrogen and its production process using renewable energy sources in several leading countries, including Australia, the European Union, India, Canada, China, Russia, the United States, South Korea, South Africa, Japan, and other nations in North Africa. These regions possess significant potential for “green” hydrogen production, supporting the transition from fossil fuels to clean energy and promoting environmental sustainability through the electrolysis process, a common method of production. The paper also examines the benefits of green hydrogen as a future alternative to fossil fuels, highlighting its superior environmental properties with zero net greenhouse gas emissions. Moreover, it explores the potential advantages of green hydrogen utilization across various industrial, c... [more]
Optimal Pathways for Nitric Acid Synthesis Using P-Graph Attainable Region Technique (PART)
Yiann Sitoh, Viggy Wee Gee Tan, John Frederick D. Tapia, Raymond R. Tan, Dominic C. Y. Foo
January 12, 2024 (v1)
Subject: Materials
Keywords: attainable region, chemical reaction network, nitric acid synthesis, P-graph, process network synthesis
Developing a chemical reaction network is considered the first and most crucial step of process synthesis. Many methods have been employed for process synthesis, such as the attainable region (AR) theory. AR states that a region of all possible configurations can be defined with all the potential products and reactants. The second method is process network synthesis (PNS), a technique used to optimise a flowsheet based on the feasible materials and energy flow. P-graph is an algorithmic framework for PNS problems. P-graph attainable region technique (PART) is introduced here as an integration of both AR and P-graph to generate optimal reaction pathways for a given process. A descriptive AR plot is also developed to represent all the possible solution structures or reaction pathways. A case study of a conventional nitric acid synthesis process was used to demonstrate this technique.
New Resources for Sustainable Thermal Insulation Using Textile and Agricultural Waste in a New Circular Economy Approach: An Overview
Saloua Biyada, Mohammed Merzouki, Jaunius Urbonavičius
January 12, 2024 (v1)
Keywords: agriculture waste, end-of-life cycle, green thermal insulation, renewable resources, textile waste
Energy conservation has emerged as a strategic target worldwide, which will enable the protection of the environment and the preservation of natural resources. Energy consumption in buildings for heating and cooling is considered one of the main sources of energy consumption in several countries. For this reason, there is an ongoing search for appropriate alternatives to preserve energy and reduce energy losses. To overcome this challenge, thermal insulation is becoming increasingly essential to save energy. Although a large number of insulation materials are used commercially, this sector still faces various challenges such as cost, thermal and mechanical properties, the end-of-life cycle, as well as health issues, etc. Furthermore, the harmful impact of buildings on the environment and health issues should be considered not only in relation to the energy expended whilst using them but also in relation to the energy performance materials they are constructed from. The insulation mater... [more]
Detection of Cotton Seed Damage Based on Improved YOLOv5
Zhicheng Liu, Long Wang, Zhiyuan Liu, Xufeng Wang, Can Hu, Jianfei Xing
January 12, 2024 (v1)
Keywords: algorithm, appearance inspection, crop seed sorting, deep learning, machine vision
The quality of cotton seed is of great significance to the production of cotton in the cotton industry. In order to reduce the workload of the manual sorting of cotton seeds and improve the quality of cotton seed sorting, this paper proposed an image-detection method of cotton seed damage based on an improved YOLOv5 algorithm. Images of cotton seeds with different degrees of damage were collected in the same environment. Cotton seeds of three different damage degrees, namely, undamaged, slightly damaged, and seriously damaged, were selected as the research objects. Labeling software was used to mark the images of these cotton seeds and the marked images were input into the improved YOLOv5s detection algorithm for appearance-based damage identification. The algorithm added the lightweight upsampling operator CARAFE to the original YOLOv5s detection algorithm and also improved the loss function. The experimental results showed that the mAP_0.5 value of the improved algorithm reached 99.5... [more]
Fe3O4@Granite: A Novel Magnetic Adsorbent for Dye Adsorption
Gamze Topal Canbaz
January 12, 2024 (v1)
Subject: Materials
Keywords: Adsorption, chemical co-precipitation, Fe3O4, magnetic granite, Reactive Black 5
Magnetic granite (MG), a new and low-cost adsorbent, was prepared by the chemical co-precipitation of Fe2+ and Fe3+ using granite (G), which is a magmatic rock type. The adsorption of the Reactive Black 5 (RB5) dye from aqueous solutions on Fe3O4-modified granite was examined in a batch system. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), X-ray fluorescence spectrometry (XRF), X-ray diffractometry (XRD), N2 adsorption−desorption, vibrating-sample magnetometry (VSM), and point-of-zero charge (pHpzc) analysis were used to characterize the prepared MG. Magnetic granite displayed significant magnetization and could be easily separated using external magnets. The maximum adsorption capacity was 29.85 mg/g at 298 K. According to kinetic and isothermal examinations, the pseudo-second-order model and Langmuir isothermal adsorption were the best fit for adsorption. It was found that the enthalpy change ΔH (kJ/mol) was −31.76,... [more]
Fractal Characterization of Particle Size and Coordinate Distribution of Dispersed Phase in the Steelmaking Process of Combined Blowing Conversion
Shiyi Chen, Xiaolei Zhou, Zhihao Zheng, Ren Chen, Shan Yu, Chunyang Shi
January 12, 2024 (v1)
Subject: Materials
Keywords: combined blowing converter, coordinate distribution, dispersed phase, fractal characterization, particle size distribution, water model
A two-dimensional water model was used to simulate the process of combined blowing. The effect of boundary conditions on the size and coordinate distribution of the dispersed phase was investigated. The results showed that the frequency of the dispersed phase at a certain size level is proportional to its size; the coordinates of the dispersed phase can be expressed in a dimensionless form that shows its uniformity of distribution. An empirical equation for the influence of the boundary conditions on the size and coordinate distribution of the dispersed phase in combined blowing process is also presented.
The Hydration Mechanisms of Co-Stabilization Saline Soils by Using Multiple Solid Wastes
Bolan Lei, Pingfeng Fu, Xiaoli Wang, Wen Ni, Siqi Zhang, Xiancong Wang, Jinjin Shi, Miao Xu
January 12, 2024 (v1)
Keywords: curing mechanism, industrial solid waste, saline soil, soil stabilizer
In this paper, an approach was employed to fabricate a curing agent using multiple solid wastes. To determine the optimal mixing ratio, orthogonal and compaction tests were initially conducted, followed by a comparative analysis of the excitation effects elicited by sodium silicate and NaOH. Remarkably, sodium silicate demonstrated superior suitability as an activator. The final composition was established as follows: 4% sodium silicate, 26% carbide slag, 25% granulated blast furnace (GBF) slag, 35% coal fly ash, and 10% flue gas desulphurization (FGD) gypsum. Under controlled conditions of 20% of curing agent content, the unconfined compressive strength of the solidified soil at 7 d attained 1.54 MPa, thereby satisfying the rigorous construction requirements for highways across all levels. XRD and SEM-EDS analyses revealed that the principal hydration products in the system consisted of ettringite, Friedel’s salt, and C-S-H gel. These products enveloped the soil particles, with ettrin... [more]
Classification and Evaluation of Tight Sandstone Reservoirs Based on MK-SVM
Xuefei Lu, Xin Xing, Kelai Hu, Bin Zhou
January 12, 2024 (v1)
Keywords: high-pressure mercury compression, lasso dimensionality reduction, MK-SVM model, reservoir classification, tight sandstone reservoirs
It is difficult to determine the main microscopic factors controlling reservoir quality due to the strong microscopic heterogeneity of tight sandstone reservoirs, which also makes it difficult to distinguish dominant reservoirs. At the same time, there are fewer experimental samples available, and data collected from relevant research are thus worth paying attention to. In this study, based on the experimental results of high-pressure mercury injection of 25 rock samples from Chang 6 reservoir in the Wuqi area, Lasso dimensionality reduction was used to reduce the dimensionality of 14 characteristic parameters to 6, which characterize the microscopic pore structure, while a combination of different kernel functions was used to construct the multi-kernel function of the multi-kernel model to be determined. A multi-kernel support vector machine (MK-SVM) model was established for unsupervised learning of microscopic pore structure characteristic parameters that affect reservoir quality. B... [more]
Active Steering Controller for Driven Independently Rotating Wheelset Vehicles Based on Deep Reinforcement Learning
Zhenggang Lu, Juyao Wei, Zehan Wang
January 12, 2024 (v1)
Keywords: active steering, Ape-X DDPG algorithm, deep reinforcement learning, independently rotating wheelsets
This paper proposes an active steering controller for Driven Independently Rotating Wheelset (DIRW) vehicles based on deep reinforcement learning (DRL). For the two-axle railway vehicles equipped with Independently Rotating Wheelsets (IRWs), each wheel connected to a wheel-side motor, the Ape-X DDPG controller, an enhanced version of the Deep Deterministic Policy Gradient (DDPG) algorithm, is adopted. Incorporating Distributed Prioritized Experience Replay (DPER), Ape-X DDPG trains neural network function approximators to obtain a data-driven DIRW active steering controller. This controller is utilized to control the input torque of each wheel, aiming to improve the steering capability of IRWs. Simulation results indicate that compared to the existing model-based H∞ control algorithm and data-driven DDPG control algorithm, the Ape-X DDPG active steering controller demonstrates better curving steering performance and centering ability in straight tracks across different running conditio... [more]
Evaluation of the Effect of Betulin and Its Alkynyl Derivatives on the Profile of Changes in Gene Expression of the Inflammatory Process of Colorectal Adenocarcinoma Cells (HT-29 Cell Line)
Agnieszka Lubczyńska, Ewa Bębenek, Agnieszka Garncarczyk, Dominika Wcisło-Dziadecka
January 12, 2024 (v1)
Subject: Biosystems
Keywords: betulin, colorectal cancer, inflammation
Betulin is a lupane-type pentacyclic triterpene. It is characterized by a range of biological properties, including anti-cancer and anti-inflammatory activities. It is also an origin compound for obtaining derivatives with higher biological activity and better bioavailability. Chronic inflammation stimulates the formation of a pro-cancer microenvironment, promoting tumor growth, cell migration, and neoangiogenesis. Many factors, immune system cells, and cytokines and chemokines released by them are involved in this process. Therefore, it has been suggested that the optimal target for anti-cancer drugs in this disease could be substances showing anti-inflammatory activity. The aim of the study was to indicate the direction of changes in the expression of genes related to the inflammatory state in colorectal cancer cells promoted by betulin and its selected alkynyl derivatives. Cytotoxicity assessment was carried out using a sulforhodamine B (SRB) test, whereas lipophilicity was determin... [more]
Evaluation of Hydrogen Addition on Combustion and Emission Characteristics of Dual-Fuel Diesel Engines with Different Compression Ratios
Su Wang, Youchang Li, Junshuai Lv, Zhonghang Liu, Sheng Gao, Jingyi Hu, Jian Zhang, Weihuang Zhong, Ziheng Zhao
January 12, 2024 (v1)
Keywords: combustion characteristics, compression ratio, dual-fuel engine, emission characteristics, hydrogen energy share
In this paper, a computational fluid dynamics (CFD) model was established and verified on the basis of experimental results, and then the effect of hydrogenation addition on combustion and emission characteristics of a diesel−hydrogen dual-fuel engine fueled with hydrogenation addition (0%, 5%, and 10%) under different hydrogenation energy shares (HESs) and compression ratios (CRs) were investigated using CONVERGE3.0 software. And, this work assumed that the hydrogen and air were premixed uniformly. The correctness of the simulation model was verified by experimental data. The values of HES are in the range of 0%, 5%, 10%, and 15%. And, the values of CR are in the range of 14, 16, 18, and 20. The results of this study showed that the addition of hydrogen to diesel fuel has a significant effect on the combustion characteristics and the emission characteristics of diesel engines. When the HES was 15%, the in-cylinder pressure increased by 10.54%. The in-cylinder temperature increased by... [more]
Rice Water—More a Source of Nutrition Elements or Toxic Arsenic? Multi-Element Analysis of Home-Made (Natural) Rice Water and Commercialized Rice-Based Products Using (HG)-ICP OES
Maja Welna, Anna Szymczycha-Madeja, Pawel Pohl
January 12, 2024 (v1)
Keywords: arsenic, multi-element analysis, nutritional value, rice water, rice-based cosmetics
Although rice is a well-known source of nutrients, it unfortunately accumulates As the most compared to other cereal plants. Due to the growing interest in rice-based cosmetics, the aim of the work was the multi-element analysis of various home-made (natural) rice waters and commercialized ready-to-use rice-based cosmetics for skin/hair. The total concentrations of Al, As Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn in raw rice and rice products were determined using inductively coupled optical emission spectrometry (ICP OES) after wet sample decomposition in the presence of concentrated HNO3. In the case of As, the hydride generation (HG) technique was used as a sample introduction system to the ICP OES instrument. Five different procedures, including washing/rinsing, soaking, boiling, and fermentation steps, and three rice types, i.e., white, brow, and jasmine, were used for this purpose. The effects of the water temperature, the contact time of rice grains with water, and the type of... [more]
Transdermal Patches Containing Opioids in the Treatment of Patients with Chronic Pain
Iolanda De Marco
January 12, 2024 (v1)
Subject: Biosystems
Keywords: buprenorphine, fentanyl, reservoir and matrix systems, transdermal patches
Transdermal delivery is a non-invasive route, used as an alternative to the oral route, to administer drugs through the skin surface. One of the fields in which they are particularly used is that of pain therapy. In this treatment, transdermal patches, particularly those containing opioids, are used to complement or replace orally administered drugs. First-generation patches are constituted by reservoir systems, where the drug is dissolved in a solvent and gelled with a polymer. In contrast, the active principle is incorporated into the polymer adhesive in more recent matrix patches. In this review, the main papers related to the production and employment of transdermal patches containing the two most used opioids, i.e., fentanyl and buprenorphine, have been critically analyzed. From the analysis of the literature, it is possible to deduce that the type of drug and the amount of drug present in the patch must be chosen not according to the origin of the pain but to the age of the patie... [more]
A Perspective on the Prospect of Pickering Emulsion in Reservoir Conformance Control with Insight into the Influential Parameters and Characterization Techniques
Muhammad Mohsin Yousufi, Iskandar bin Dzulkarnain, Mysara Eissa Mohyaldinn Elhaj, Shehzad Ahmed
January 12, 2024 (v1)
Subject: Materials
Keywords: conformance control, emulsion, Pickering emulsion
In reservoir conformance control, polymer gels and foams are majorly used; however, they have drawbacks such as inducing formation damage, having weaker shear resistance, requiring a higher pumping rate, and limited penetration depth. Emulsions are a potential alternative that can address these issues, but they are not widely used. Current surfactant-based emulsions require high emulsifier concentrations for stability and often rely on multiple additives to address various factors, which makes the surfactant synthesis and utilization of emulsions quite challenging. However, Pickering emulsions, which utilize solid particles for emulsion stabilization, have emerged as a promising solution for reservoir conformance control. Compared to conventional polymer gels and foams, Pickering emulsions offer superior shear resistance, deeper penetration, and reduced formation damage. This review provides an overview of recent developments in the utilization of Pickering emulsions for conformance co... [more]
Comparative Study of Rhodamine B Treatment: Assessing of Efficiency Processes and Ecotoxicity of By-Products
Thomas Chadelaud, Hicham Zeghioud, Alonso Reynoso de la Garza, Omar Fuerte, Adriana Benítez-Rico, Messika Revel, Tomás E. Chávez-Miyauchi, Hayet Djelal
January 12, 2024 (v1)
Subject: Materials
Keywords: eco-toxicity assessment, photocatalysis, Rhodamine B degradation, Saccharomyces cerevisiae, TiO2-Ce
In this work, a comparative study between two processes was performed—biodegradation and photocatalysis, as an advanced oxidation process—to discover which one is more efficient to degrade Rhodamine B, a synthetic dye widely used in the textile and food industries. The advantage of this study is that it correlates treatment efficiency with the ecotoxicity of the by-products resulting from the treatments. Since the COVID-19 pandemic, it has been difficult to use activated sludge because of the risk factor of COVID-19 infection. Therefore, biodegradation tests were conducted with the yeast Saccharomyces cerevisiae in this study. For the photocatalysis assays, TiO2 doped with 5 per cent Cerium was used as a catalyst under UV light irradiation. S. cerevisiae cannot reduce RhB by biodegradation. However, a 13 per cent biosorption was observed with an uptake capacity of 4.2 mg g−1 dry matter of S. cerevisiae cultivated in the presence of 5 mg L−1 of RhB after 150 min. At a 5 mg L−1 of RhB co... [more]
Research on Downhole Throttling Characteristics of Gas Wells Based on Multi-Field and Multi-Phase
Jie Zheng, Jiahui Li, Yihua Dou, Zhihao Hu, Xu Yang, Yarong Zhang
January 12, 2024 (v1)
Keywords: downhole throttling characteristics, multi-field and multi-phase coupling, temperature and pressure field model
The formation of natural gas hydrates seriously affects the production efficiency of gas wells. Obtaining the correct temperature and pressure profile along the wellbore of gas wells is a prerequisite for accurately predicting the location of hydrate formation and using downhole throttling technology. According to the numerical iterative transfer law of wellbore microelement state parameters, a multi-field and multi-phase coupling method is proposed. Based on the analysis of typical temperature and pressure models, considering the gas well velocity field and density field, a gas well multi-phase correction coefficient is introduced. Based on the judgment method of multi-phase flow pattern, the friction gradient equation of multi-phase flow is obtained, and the respective theoretical prediction equations are created for the temperature field, pressure field, density field, and velocity field. Thereby, a wellbore temperature and pressure field model with multi-field and multi-phase coupl... [more]
Design and Analysis of a Novel Air Bubble Curtain for Mixing and Aeration in Process Vessels
Omar Chaalal, Chandra Mouli R. Madhuranthakam, Husain Al Hashimi, Marouane Chaalal, Weam S. K. Abudaqqa
January 12, 2024 (v1)
Keywords: bubble curtain, Mixing, pilot-scale studies, process vessels, residence time distribution
This article focuses on designing and analyzing a new method for mixing in process vessels. We propose using an air bubble curtain to accomplish the desired mixing. The air bubble curtain used in this study is made of an empty pipe with several holes through which air is pumped, which in turn produces a swarm of bubbles that causes pseudo-turbulent mixing in the tank filled with a liquid solution. A uniform distribution of bubbles within the tank was assured by maintaining a see-saw movement of the air bubble curtain. Mixing inside the tank was quantified by measuring the salt concentration in a laboratory model tank (30 cm × 30 cm × 30 cm) and a pilot-scale tank (200 cm × 100 cm × 100 cm). The optimal flow rates of air and the mixing time in both tanks that can achieve complete mixing were obtained from the experimental results. The proposed air bubble curtain can be of potential use in wastewater treatment, biotechnology, and aquaculture where turbulent mixing is required with minimu... [more]
Multi-Scale Fractal Characteristics of the Pore System in Low-Permeability Conglomerates from the Junggar Basin
Jiayu Zheng, Weichao Tian, Yang Gao, Zhigang Wen, Yunpeng Fan, Heting Gao, Shuangfang Lu, Xiaoyin Zheng
January 12, 2024 (v1)
Subject: Materials
Keywords: fractal characteristics, Junggar Basin, low-permeability conglomerates, NMR, pore system
The pore structure and its complexity play a critical role in fluid migration and recovery efficiency. Multiple pore types, broad pore size distribution (PSD), and extremely irregular pore morphology hinder the comprehensive investigation of pore systems and their complexity in low-permeability conglomerates. In this study, the multi-scale pore system and fractal characteristics of the Permian Lower Wuerhe Formation and Triassic Baikouquan Formation conglomerates from the Junggar Basin were investigated, combining physical property analysis, casting thin sections, scanning electron microscopy, and Nuclear magnetic resonance (NMR). The results show that the pore system of conglomerates consists of residual intergranular pores (RIPs), dissolution pores (DPs), clay-related pores (CRPs), and microfractures. Three types of PSD were identified according to the shape of the T2 spectrum. Based on the fractal characteristics derived from NMR data, pore systems in conglomerates were divided into... [more]
Recovering Polyphenols in Aqueous Solutions from Olive Mill Wastewater and Olive Leaf for Biological Applications
Adrián Hernández-Fernández, Yolanda Garrido, Eduardo Iniesta-López, Antonia Pérez de los Ríos, Joaquín Quesada-Medina, Francisco José Hernández-Fernández
January 12, 2024 (v1)
Keywords: circular economy, hydroxytyrosol, oleuropein, olive leaf, olive mill wastewater, polyphenols
Olive leaf and olive mill wastewater are wastes which are produced in olive industry and can be used to obtain value-added products such as polyphenols. In this work, extracts of polyphenols from olive mill wastewater and olive leaf in an aqueous medium are obtained and their composition in polyphenols were determined and compared with those obtained using the conventional extract agent (methanol−water). The antioxidant capacity of the aqueous extracts of olive mill wastewater and olive leaf were also analysed. It was observed that the olive mill wastewater extracted in water provides a similar content of phenolic compounds in the final extract compared to extraction with methanol−water, with the main polyphenols being hydrotyrosol and tyrosol (20.1 and 6.61 mg gdw−1). In the case of leaf extraction, the methanol-free extract (recovery in water after extraction with methanol−water) had a lower total phenol content compared to the methanolic extract, with the main polyphenol being oleur... [more]
Fast Prediction of the Temperature Field Surrounding a Hot Oil Pipe Using the POD-BP Model
Feng Yan, Kaituo Jiao, Chaofei Nie, Dongxu Han, Qifu Li, Yujie Chen
January 12, 2024 (v1)
Keywords: BP neural network, hot oil pipe, POD prediction, temperature field
The heat transfer assessment of a buried hot oil pipe is essential for the economical and safe transportation of the pipeline, where the basis is to determine the temperature field surrounding the pipe quickly. This work proposes a novel method to efficiently predict the temperature field surrounding a hot oil pipe, which combines the proper orthogonal decomposition (POD) method and the backpropagation (BP) neural network, named the POD-BP model. Specifically, the BP neural network is used to establish the mapping relationship between spectrum coefficients and the preset parameters of the sample. Compared with the classical POD reduced-order model, the POD-BP model avoids solving the system of reduced-order governing equations with spectrum coefficients as variables, thus improving the prediction speed. Another advantage is that it is easy to implement and does not require tremendous mathematical derivation of reduced-order governing equations. The POD-BP model is then used to predict... [more]
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