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Showing records 2826 to 2850 of 43675. [First] Page: 110 111 112 113 114 115 116 117 118 Last
Analysis of Greenhouse Gas Emissions Characteristics and Emissions Reduction Measures of Animal Husbandry in Inner Mongolia
Yingnan Cao, Xiaoxia Yang, Fang Yang, Ying Sun, Qianqian Wang, Futian Ren, Lei Nie, Aodemu, Weiying Feng
September 20, 2023 (v1)
Subject: Environment
Keywords: animal husbandry, emissions reduction, greenhouse gases
Global warming has had a profound impact on human life, with animal husbandry being a significant contributor to greenhouse gas emissions and playing a crucial role in the global greenhouse gas budget. Inner Mongolia is a major contributor to these emissions, making it vital to study the link between greenhouse gas emissions and animal husbandry in this region for the purpose of reducing emissions. In this study, the emissions of greenhouse gases (CH4, N2O, and CO2) from livestock and poultry breeding from 2010 to 2020 and the emissions of each city from 2020 were estimated, the emissions characteristics were analysed, and the low carbon emissions reduction technical measures were proposed. The results show that (1) the overall greenhouse gas emissions from 2010 to 2020 in Inner Mongolia showed a fluctuating trend; the main emissions sources were gastrointestinal fermentation and faecal management. The annual average CH4 emissions were 994,400 ta−1, and the annual average N2O emissions... [more]
Research on the Optimization of the Operating Parameters of Methane Carbon Dioxide Reforming Using the Response Surface Methodology
Xing Huang, Zhengguo Lv, Xin Yao, Yang Liu, Yuhe Wang, Sijia Zhu
September 20, 2023 (v1)
Keywords: BBD, chemkin simulation, methane carbon dioxide reforming, parameter optimization, response surface methodology
In order to reduce the production cost of the methane carbon dioxide reforming reaction, and improve its actual production efficiency, in this paper, the optimal working parameters of the methane carbon dioxide reforming reaction are studied. The influence of different factors on methane conversion is studied via a single-factor numerical simulation analysis and the response surface methodology. Firstly, a numerical model of the methane carbon dioxide reforming reaction is established using Ansys Chemkin Pro software to analyze the influence of single factors (reactor temperature, reaction pressure, gas velocity) on methane conversion rate; secondly, the response surface model with the methane conversion rate as the response value is established using the BBD (Box−Behnken design) method; and finally, the order of influence of each variable on methane conversion and the optimal reaction conditions are determined using the response surface method. The factors are listed in order of their... [more]
The Influence of a Key Indicator kv on the Diffusion Range of Underwater Oil Spill
Hong Ji, Yaxin Wang, Ting Wang, Ke Yang, Zhixiang Xing
September 20, 2023 (v1)
Subject: Environment
Keywords: a key indicator kv, fitting curve, oil spill, physical model experiment, submarine pipeline
As oil spills cause harm to the survival and environment of the ocean, the objective of the present paper is to study the oil migration range using the key indicator kv, which is defined as the ratio of oil spill speed to ocean current speed. The correctness of diffusion models created and estimated for subsea oil spills can be verified by experiments. We also considered the effect of key indicators on the horizontal and vertical dispersion ranges of oil spills. The study’s findings show that, under various kv settings, the horizontal and vertical spreading heights of oil spills both increase as kv rises. When kv is equal, the leakage velocity and water flow velocity increase synchronously, and over time, the horizontal distance and vertical diffusion height of the oil spill gradually increase. In the early stages of an oil spill, when kv = 50, 100, or 150, the vertical spreading velocity will rapidly decrease. The vertical spreading speed of spilled oil increases as kv rises when the... [more]
Remaining Useful Life Prediction for Lithium-Ion Batteries Based on a Hybrid Deep Learning Model
Chao Chen, Jie Wei, Zhenhua Li
September 20, 2023 (v1)
Keywords: channel attention mechanism, lithium-ion batteries, long short-term memory, remaining useful life
Lithium-ion batteries are widely utilized in various fields, including aerospace, new energy vehicles, energy storage systems, medical equipment, and security equipment, due to their high energy density, extended lifespan, and lightweight design. Precisely predicting the remaining useful life (RUL) of lithium batteries is crucial for ensuring the safe use of a device. In order to solve the problems of unstable prediction accuracy and difficultly modeling lithium-ion battery RUL with previous methods, this paper combines a channel attention (CA) mechanism and long short-term memory networks (LSTM) to propose a new hybrid CA-LSTM lithium-ion battery RUL prediction model. By incorporating a CA mechanism, the utilization of local features in situations where data are limited can be improved. Additionally, the CA mechanism can effectively mitigate the impact of battery capacity rebound on the model during lithium-ion battery charging and discharging cycles. In order to ensure the full valid... [more]
Coal Pillar Size Determination and Surrounding Rock Control for Gob-Side Entry Driving in Deep Soft Coal Seams
Zaisheng Jiang, Wenke Guo, Shengrong Xie
September 20, 2023 (v1)
Subject: Materials
Keywords: deep mine, gob-side entry driving, joint control, small coal pillar, soft coal seam
In response to the large-scale instability failure problem of designing coal pillars and support systems for gob-side entry driving (GSED) in high-stress soft coal seams in deep mines, the main difficulties in the surrounding rock control of GSED were analyzed. The relationship between the position of the main roof breaking line, together with the width of the limit equilibrium zone and a reasonable size for the coal pillar, were quantified through theoretical calculations. The theoretical calculations showed that the maximum and minimum widths of the coal pillar are 8.40 m and 5.47 m, respectively. A numerical simulation was used to study the distribution characteristics and evolution laws of deviatoric stress and plastic failure fields in the GSED surrounding rock under different coal pillar sizes. Theoretical analysis, numerical simulation, and engineering practice were comprehensively applied to determine a reasonable size for narrow coal pillars for GSED in deep soft coal seams, w... [more]
Antibacterial Effect of Polyvinyl Alcohol/Biochar−Nano Silver/Sodium Alginate Gel Beads
Licheng Xie, Zhichao Zhang, Yucai He
September 20, 2023 (v1)
Subject: Biosystems
Keywords: antibacterial ability, fish-scale biochar, nanosilver antibacterial composite
To date, biochar bacteriostatic material has attracted much attention from researchers. The compact porous structure of fish-scale biochar provides good application prospects. In this study, silver-carrying biochar−polyvinyl alcohol−alginate gel beads (C/PVA/SA) were designed for suppressing bacteria. The biochar was loaded with nano silver particles as the filler, alginate as the substrate, and polyvinyl alcohol (PVA) as the additive to enhance the mechanical properties. The composite gel beads were characterized using Fourier-transform infrared spectrometry (FT-IR). The results indicated that adjusting the PVA concentration could retain the bacteriostatic performance of the gel beads in different pH value solutions. It was found that C/PVA/SA gel beads had a strong inhibitory effect on Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. After ten consecutive antibacterial tests, the antibacterial rate remained high (above 99%) for 15 days. The adhesive effect of SA a... [more]
Distributed Fixed-Time Secondary Control for MTDC Systems Using Event-Triggered Communication Scheme
Xiaoyue Zhang, Xinghua Liu, Peng Wang
September 20, 2023 (v1)
Keywords: distributed fixed-time control, event-triggered communication scheme, MTDC system
Multi-terminal DC transmission (MTDC) systems have attracted much attention due to their significant advantages in long-distance and high-capacity transmission. To improve their reliability and operation performance, a distributed fixed-time secondary control of frequency restoration and active power sharing is proposed under event-triggered communication, which only depends on the states of each AC grid and its neighbors. By utilizing Lyapunov theory, we prove that the MTDC system with the fixed-time secondary control can be stable in a settling time, and the conditions of the settling time are established for fixed-time algorithms. In addition, we simulate a five-terminal MTDC system in Matlab/Simulink. Several cases of MTDC systems are exhibited to showcase how well the suggested controller works when dealing with load changes and attacks. The comparison of the number of event-triggered instants shows that the proposed control method can effectively reduce communication resources.
The Physical, Sensory, and Microbial Qualities of Broth Gels Enclosing Food Cubes and Their Changes during Cold Storage
Yang-Ju Son, Ji-Yu Choi
September 20, 2023 (v1)
Keywords: chicken stock, gel food, gelatin, jelly, sensory evaluation, κ-carrageenan
Due to their unusual textural properties and semblance, gel foods have been welcomed by consumers. In this study, we designed a novel gel food, that is, broth jellies that enclosed particular food dices (shrimp, chicken, and potatoes). Briefly, various ratios of gelling molecules (gelatin and κ-carrageenan) were added to chicken broth, the food dices were placed in the center of the gels, and their characteristics and stabilities were verified during cold storage (4 °C) for 14 days. As a result, the mix of κ-carrageenan and gelatin led to the formation of firm cross-junctions with an elevated hardness compared to gelatin singular gel. In contrast, the gelatin sole gel showed different sensory attributes, such as a high chewiness and meltiness. The thick gel barriers of the products fairly increased the stability of the inner food ingredients. By blocking the loss of moisture, the texture and sensory traits were well preserved; moreover, the gelling molecules greatly impeded microbial d... [more]
Prediction of Refractive Index of Petroleum Fluids by Empirical Correlations and ANN
Georgi Nikolov Palichev, Dicho Stratiev, Sotir Sotirov, Evdokia Sotirova, Svetoslav Nenov, Ivelina Shishkova, Rosen Dinkov, Krassimir Atanassov, Simeon Ribagin, Danail Dichev Stratiev, Dimitar Pilev, Dobromir Yordanov
September 20, 2023 (v1)
Keywords: ANN, empirical correlation, intercriteria analysis, Petroleum, refractive index
The refractive index is an important physical property that is used to estimate the structural characteristics, thermodynamic, and transport properties of petroleum fluids, and to determine the onset of asphaltene flocculation. Unfortunately, the refractive index of opaque petroleum fluids cannot be measured unless special experimental techniques or dilution is used. For that reason, empirical correlations, and metaheuristic models were developed to predict the refractive index of petroleum fluids based on density, boiling point, and SARA fraction composition. The capability of these methods to accurately predict refractive index is discussed in this research with the aim of contrasting the empirical correlations with the artificial neural network modelling approach. Three data sets consisting of specific gravity and boiling point of 254 petroleum fractions, individual hydrocarbons, and hetero-compounds (Set 1); specific gravity and molecular weight of 136 crude oils (Set 2); and speci... [more]
A Novel Thermal Lattice Boltzmann Method for Numerical Simulation of Natural Convection of Non-Newtonian Fluids
Xiaofei Ren, Feifei Liu, Zheng Xin
September 20, 2023 (v1)
Keywords: heat transfer, lattice Boltzmann method, natural convection, non-Newtonian fluids, power–law model
A modified thermal Bhatnagar−Gross−Krook Lattice Boltzmann (BGK-LB) model was developed to study the convection phenomenon of non-Newtonian fluids (NNFs). This model integrates the local shear rate into the equilibrium distribution function (EDF) of the flow field and keeps the relaxation time from varying with fluid viscosity by introducing an additional parameter. In addition, a modified temperature EDF was constructed for the evolution equation of the temperature field to ensure the precise recovery of the convection−diffusion equation. To validate the accuracy and effectiveness of the proposed model, numerical simulations of benchmark problems were performed. Subsequently, we investigated the natural convection of power−law (PL) fluids and examined the impact of the PL index (n = 0.7−1.3) and Rayleigh number (Ra = 103−5 × 105) on the flow and temperature fields while holding the Prandtl number (Pr = 7) constant. The obtained results indicate that, for a given value of n, the convec... [more]
Identifying the Saturated Line Based on the Number of Idle Places: Achieving Precise Maximal Permissiveness without Deadlocks Using Control Transitions or Control Places
Ter-Chan Row, Shih-Chih Lee, Yen-Liang Pan
September 20, 2023 (v1)
Keywords: deadlock prevention, deadlock recovery, flexible manufacturing systems, Petri nets
In the flexible manufacturing system deadlock prevention domain, researchers’ almost final target is to seek the maximally permissive controllers for solving the deadlock problems of flexible manufacturing systems. However, it seems a challenging work. Whatever you adopt, what kinds of methods, policies, and strategies, it seems complicated to obtain optimal controllers for deadlock prevention even if they claim their algorithms are optimal until the deadlock recovery is developed. Therefore, many experts, including us, have decided to design all kinds of actual maximally permissive recovery policies based on control transitions. It is a pity that these policies usually solve some particular flexible manufacturing systems’ deadlock problems. The controllers failed to recover the deadlock situation of flexible manufacturing systems once the idle or resource places were changed. In other words, these policies could never know or identify the real number of maximally permissive controller... [more]
Critical Analysis of Risk Factors and Machine-Learning-Based Gastric Cancer Risk Prediction Models: A Systematic Review
Zeyu Fan, Ziju He, Wenjun Miao, Rongrong Huang
September 20, 2023 (v1)
Subject: Biosystems
Keywords: classification algorithm, gastric cancer, Machine Learning, predictive factors, risk prediction model
The gastric cancer risk prediction model used for large-scale gastric cancer screening and individual risk stratification is an artificial intelligence tool that combines clinical diagnostic data with a classification algorithm. The ability to automatically make a quantitative assessment of complex clinical data contributes to increased accuracy for diagnosis with higher efficiency, significantly reducing the incidence of advanced gastric cancer. Previous studies have explored the predictive performance of gastric cancer risk prediction models, as well as the predictive factors and algorithms between each model, but have reached controversial conclusions. Thus, the performance of current machine-learning-based gastric cancer risk prediction models alongside the clinical relevance of different predictive factors needs to be evaluated to help build more efficient and feasible models in the future. In this systematic review, we summarize the current research progress related to the gastri... [more]
Fault Diagnosis Based on Fusion of Residuals and Data for Chillers
Zhanwei Wang, Boyang Liang, Jingjing Guo, Lin Wang, Yingying Tan, Xiuzhen Li, Sai Zhou
September 20, 2023 (v1)
Keywords: chillers, data, fault diagnosis, fusion, residual
Feature data refer to direct measurements of specific features, while feature residuals represent the deviations between these measurements and their corresponding benchmark values. Both types of information offer unique insights into the system’s behavior. However, conventional diagnostic systems often struggle to effectively integrate and utilize both types of information concurrently. To address this limitation and improve diagnostic performance, a hybrid method based on the Bayesian network (BN) is proposed. This method enables the parallel fusion of feature residuals and feature data within a unified diagnostic model, and a comprehensive framework for developing this hybrid method is also given. In the hybrid BN, the symptom layer consists of residual nodes representing feature residuals and data nodes representing measured feature data. By applying the proposed method to two chillers and comparing it with state-of-the-art existing methods, we demonstrate its effectiveness and sup... [more]
An Overview of Flashing Phenomena in Pressure Hydrometallurgy
Junda Liu, Bin Liu, Ping Zhou, Di Wu, Caigui Wu
September 20, 2023 (v1)
Keywords: flash tank, flashing process, gas–liquid–solid flow, numerical simulation, pressure hydrometallurgy
Pressure hydrometallurgy has attracted much attention for its characteristics, such as the high adaptability of raw materials and environmental friendliness. Flashing (flash boiling or flash evaporation) refers to the phase change phenomenon from liquid to gas triggered by depressurization, which is an important connection between high-pressure processes and atmospheric ones in pressure hydrometallurgy. This paper takes the flashing process in zinc leaching and alumina Bayer processes as examples, describes the flashing process in pressure hydrometallurgy in detail for the first time, and shows the importance of the flashing process in energy recovery, solution concentration, and liquid balance, as well as increasing equipment life. According to solid holdup (the volume percentage of solid), this paper proposes to divide the flashing process into solution flashing (low solid holdup) and slurry flashing (high solid holdup). A further focus is put on reviewing the state of the art of rel... [more]
The Process of Developing Model Research for the Technology of Obtaining Energy Resources
Dawid Szurgacz, Beata Borska, Lukáš Pospíšil, Dagmar Dlouhá, Jiří Pokorný, Sergey Zhironkin
September 20, 2023 (v1)
Keywords: hydraulic prop, longwall mining, mathematical model of the prop, numerical simulation, powered roof support
The current problems associated with the maintenance of hard coal longwall mining depend on the application or use of extraction technologies. In order to make the best use of these technologies, a new approach based on simulation studies is necessary. This paper aims to develop a mathematical model for the powered roof support’s operation. The three groups of professionals involved in the testing of the roof support were involved in the work on changing the hydraulic system of the powered roof support stand. These professionals were powered roof support’s designers, researchers and users. The research subject was the development of a mathematical model as a starting point for conducting simulations. The model is based on d’Alembert’s principle and the equation of the balance of flow rates. Based on the developed model, it is possible to determine the pressure in the space under the piston of the hydraulic prop. The results obtained in the simulations are the basic assumptions for the... [more]
Study on Mechanical Behavior and Mechanism of Sandstone under the Coupling Effect of Water Content and Dynamic Load
Yang Chen, Ting Kang, Chao Wu
September 20, 2023 (v1)
Keywords: crushing characteristics, Energy Conversion, impact load, saturation degree, weakening of strength
In the process of underground engineering construction, rock mass often faces the dual influence of dynamic load disturbance and groundwater, it is therefore essential to investigate the mechanical response of the rock mass under the coupling effect of dynamic load disturbance and water content. In this paper, dynamic load impact tests were carried out on sandstone with bullet velocities of 5 m/s, 10 m/s, and 15 m/s and water content of 0, 0.3, 0.6, and 0.9, and the mechanical behavior and mechanism response of water content to sandstone were investigated. The research findings indicate that this study has made significant contributions in quantifying the along grain and trans-grain fractures of microcracks. It has explored the influence of water content and dynamic loading on the strength mechanism of sandstone. It was discovered that the dynamic loading and water content significantly affect the ratio of along grain and trans-grain fractures, thereby influencing the dynamic behavior... [more]
Mineralogical Characteristics and Arsenic Release of High Arsenic Coals from Southwestern Guizhou, China during Pyrolysis Process
Bengen Gong, Chong Tian, Xiang Wang, Xiaoxiang Chen, Junying Zhang
September 20, 2023 (v1)
Keywords: arsenic release, low temperature ashing, mineral transformation, pyrolysis
Coal is the primary energy source in China, and coal pyrolysis is considered an essential and efficient method for clean coal utilization. Three high arsenic coals collected from the southwestern Guizhou province of China were chosen in this study. Low-temperature ashing plus X-ray diffraction analysis (XRD) was used to identify the minerals in coals. The three coals were pyrolyzed in a tube furnace in an N2 atmosphere at 950 °C, 1200 °C, and 1400 °C, respectively. Environment scanning electron microscope (ESEM), XRD, X-ray fluorescence analysis (XRF), and inductively coupled plasma-mass spectrometry (ICP-MS) were adopted to determine the morphology, mineral compositions, and element compositions and arsenic contents of the coal pyrolysis ashes, respectively. It can be found that minerals in coal are mainly composed of quartz, pyrite, muscovite, and rutile. The minerals in the ashes generated from coal pyrolysis mainly contain quartz, dehydroxylated muscovite, iron oxide minerals, mull... [more]
Strain Field Evolution Analysis of Brittle Shale with Initial Fractures Based on DIC
Weihang Liu, Zhan Qu
September 20, 2023 (v1)
Subject: Other
Keywords: brittle shale, crack propagation, DIC, rock damage
Wellbore instability mainly occurs in shale formations, and it is of great significance to deeply analyze the characteristics of shale-failure behavior to evaluate the stability of the shale surrounding the well wall during drilling. Through a uniaxial compression experiment and DIC technology, the whole strain field of shale specimens with prefabricated holes and cracks under uniaxial compression is measured. The experimental data of load, displacement and strain field are analyzed comprehensively. The results show that the fracture location and expansion path of shale are closely related to the evolution of the strain field. The evolution of the strain field directly affects the failure behavior of the rock. Under the action of load, local high strain will first appear around the initial shale defects (pores and fractures), and stress concentration will occur. With the increase of load, cracks and failures will first appear in the local high-strain zone, and the failure will spread a... [more]
Nonlinear Adaptive Generalized Predictive Control for PH Model of Nutrient Solution in Plant Factory Based on ANFIS
Yonggang Wang, Ning Zhang, Chunling Chen, Yingchun Jiang, Tan Liu
September 20, 2023 (v1)
Keywords: adaptive neuro-fuzzy inference system (ANFIS), generalized predictive control (GPC), nonlinear adaptive control, nutrient solution, pH control, plant factory
A plant factory is typically considered to be an exceedingly advanced product management system characterized by higher crop yields and better quality control. The pH value of the nutrient solution is crucial for determining the health and productivity of crops. However, the nutrient solution process exhibits inherent complexity, such as parameters uncertainty, multi-disturbances, and strong nonlinearity. Therefore, the traditional control method cannot meet the necessary requirements. The main objective of this paper is to address the issues of parameter uncertainty, strong nonlinearity, and multiple disturbances in the regulation process of the nutrient solution while achieving accurate control of the nutrient solution pH in a plant factory. This is performed so that a dynamic model of a nutrient solution for pH is developed and a nonlinear adaptive controller is presented, which comprises a linear adaptive generalized predictive controller, a nonlinear adaptive generalized predictiv... [more]
The Enhanced Oil Recovery Effect of Nitrogen-Assisted Gravity Drainage in Karst Reservoirs with Different Genesis: A Case Study of the Tahe Oilfield
Hong Cheng
September 20, 2023 (v1)
Keywords: carbonate reservoir, enhanced oil recovery, fracture vuggy, karst reservoirs with different genesis, nitrogen-assisted gravity drainage
For the Tahe Oilfield, there are multiple sets of karst reservoirs with different genesis developed in carbonate fracture-vuggy reservoirs and the varying karst reservoir type has a considerable influence on the distribution of residual oil. The complex characteristics of different karst reservoirs and the difficulty in producing the remaining oil in the middle and lower part of the reservoir greatly restrict the recovery effects. This work managed to comprehensively investigate the action mechanism of nitrogen-assisted gravity drainage (NAGD) on remaining oil in reservoirs with different karst genesis through modeling and experiments. Based on geological characteristics and modeling results, a reservoir-profile model considering reservoir type, fracture distribution, and the fracture−cave combination was established, the displacement experiments of main reservoirs such as the epikarst zone, underground river, and fault karst were carried out, and the oil−gas−water multiphase flow was... [more]
Design and Implementation of a Three-Dimensional CAD Graphics Support Platform for Pumps Based on Open CASCADE
Houlin Liu, Zhicai Wu, Shuolei Yuan, Yong Wang, Liang Dong
September 20, 2023 (v1)
Keywords: centrifugal pump parameterized modeling, geometric kernel, rendering engine, three-dimensional computer-aided design, three-dimensional visualization
In the pump industry, designers commonly utilize mainstream three-dimensional computer-aided design (CAD) software (Unigraphics NX 12.0 and SolidWorks 2023). However, these CAD packages are generic and not optimized for the specific requirements of the pump industry. This leads to a lack of flexibility and increased complexity in their usage, as well as higher computational demands, resulting in elevated learning and operational costs. Additionally, there are concerns about potential information leaks and software restrictions. In this paper, we studied the organization architecture of commercial three-dimensional CAD software, and compared and analyzed the geometric kernels and rendering engines of mainstream three-dimensional software. Using the Open CASCADE geometric kernel and OpenSceneGraph rendering engine, together with the Visual Studio 2021 development environment and Qt interface library, we developed an autonomous copyright three-dimensional CAD graphics support platform for... [more]
Pore Structure Change in the Continental Shale Oil Reservoir and Its Main Influencing Factors: A Case Study of the Chang 7 Member in the Ordos Basin
Xin He, Shijia Chen, Cong Hu, Haifeng Zhang, Feisheng Mou, Linfeng Dai, Yifan Lu, Xiaoyan Fu, Meimei Han
September 20, 2023 (v1)
Subject: Materials
Keywords: Chang 7 member, influencing factors, oil content, Ordos Basin, reservoir, shale oil
Shale oil in the Chang 7 member is the main target for further exploration in the Ordos Basin. However, the lack of research on the characteristics of the Chang 7 member’s mudstone and shale reservoir has seriously affected the next stage of exploration for shale oil in the Chang 7 member. This study analyzed in detail the changes in the pore structure of different types of reservoirs and their influencing factors in detail through experiments such as gas adsorption, nuclear magnetic resonance, and high-pressure mercury intrusion. The results showed that black shale is mainly composed of micropores, with a micropore ratio of up to 79.88%. Dark mudstone and silty mudstone are mainly composed of mesopores, with a mesopore ratio greater than 30%. Argillaceous sandstone is mainly composed of large pores, accounting for 78.57%. From black shale to muddy sandstone, the proportion of micropores decreases, while the proportion of macropores increases. The micropore volume is mainly controlled... [more]
High Dimensional Model Representation Approach for Prediction and Optimization of the Supercritical Water Gasification System Coupled with Photothermal Energy Storage
Haoxing Li, Jianhong Lei, Ming Jia, Hongpeng Xu, Shaohua Wu
September 20, 2023 (v1)
Keywords: high dimensional model representation (HDMR), multi-objective optimization, photothermal energy storage, supercritical water gasification
Supercritical water gasification (SCWG) coupled with solar energy systems is a new biomass gasification technology developed in recent decades. However, conventional solar-powered biomass gasification technology has intermittent operation issues and involves multi-variable characteristics, strong coupling, and nonlinearity. To solve the above problems, firstly, a solar-driven biomass supercritical water gasification technology combined with a molten salt energy storage system is proposed in this paper. This system effectively overcomes the intermittent problem of solar energy and provides a new method for the carbon-neutral process of hydrogen production. Secondly, the high dimensional model representation (HDMR) approach, as a surrogate model, was used to predict the production and lower heating value of syngas developed in Aspen Plus, which were validated using experimental data obtained from the literature. The ultimate analysis of biomass, temperature, pressure, and biomass-to-wate... [more]
Techno-Economic Considerations on Nanocellulose’s Future Progress: A Short Review
Giannis Penloglou, Aikaterini Basna, Alexandros Pavlou, Costas Kiparissides
September 20, 2023 (v1)
Keywords: bacterial nanocellulose (BNC), lignocellulosic biomass, nanocellulose, nanocrystalline cellulose (NCC), nanofibrillated cellulose (NFC), production cost, Technoeconomic Analysis
Nanocellulose (NC) is an emerging natural material that offers great potential for various applications due to its unique properties and renewable character. Nowadays, as NC production technologies are advancing, it is essential to evaluate their economic feasibility, technological maturity and commercialization potential using systematic techno-economic analysis (TEA). The present study considers both technical and economic aspects of NC production and analyzes them in two ways: first, by developing a new concept based on the production of different types of NC through the conversion of lignocellulosic biomass by chemical and mechanical technologies, and second, by a comparative review of existing TEA studies in the open literature. Three specific scenarios and two case studies are evaluated by comparing specific key performance indicators (KPIs), such as the production cost (PC) and minimum product selling price (MPSP) of NC. As a result, a short though comprehensive overview of the... [more]
Study on Mechanism of MSWI Fly Ash Solidified by Multiple Solid Waste-Based Cementitious Material Using the Rietveld Method
Xiaoli Wang, Pingfeng Fu, Wei Deng, JinJin Shi, Miao Xu
September 20, 2023 (v1)
Subject: Materials
Keywords: cementitious material, heavy metals, MSWI fly ash, multiple solid waste, Rietveld method, solidification, X-ray diffraction
A novel multiple solid waste-based cementitious material (MSWCM) was developed to immobilize municipal solid waste incineration (MSWI) fly ash. The compressive strength of MSWCM with different ratios of MSWI fly ash reached the standard requirements after curing for 28 days. X-ray powder diffraction (XRD) in combination with the Rietveld method was employed to investigate the content and phase transformation of hydration products. The main hydration products of pure MSWCM paste were C-S-H, hydroxyapatite, ettringite and C-A-S-H. With increases in curing time, the content of ettringite and C-A-S-H increased significantly. The main hydration products of MSWCM paste with MSWI fly ash were C-S-H and Friedel’s salt. The contents increased markedly with increased curing time from 21.8% to 28.0% and from 8.53% to 16.7%, respectively. Additionally, a small amount of PbHPO4 (0.51−0.96%) and lead phosphate Pb3(PO4)2 (0.14−0.51%) were detected, indicating that phosphate had an effective curing ef... [more]
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