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Showing records 34054 to 34078 of 43292. [First] Page: 1 1360 1361 1362 1363 1364 1365 1366 1367 1368 Last
34054. LAPSE:2023.5079
Analysis of the Effects of Process Parameters on Start-Up Operation in Continuous Wet Granulation
February 23, 2023 (v1)
Subject: Process Design
Keywords: continuous manufacturing, design of experiments, economic assessment, first-order system, granule size distribution, kernel PCA, pharmaceutical tablet, regulations, torque
Toward further implementation of continuous tablet manufacturing, one key issue is the time needed for start-up operation because it could lead to lower product yield and reduced economic performance. The behavior of the start-up operation is not well understood; moreover, the definition of the start-up time is still unclear. This work investigates the effects of process parameters on the start-up operation in continuous wet granulation, which is a critical unit operation in solid drug manufacturing. The profiles of torque and granule size distribution were monitored and measured for the first hour of operation, including the start-up phase. We analyzed the impact of process parameters based on design of experiments and performed an economic assessment to see the effects of the start-up operation. The torque profiles indicated that liquid-to-solid ratio and screw speed would affect the start-up operation, whereas different start-up behavior resulted in different granule size. Depending... [more]
34055. LAPSE:2023.5078
Possibilities of Using Organic Waste after Biological and Physical Processing—An Overview
February 23, 2023 (v1)
Subject: Materials
Keywords: combustion, composting, digestate, fertiliser, organic waste, pyrolysis
With a rapidly increasing amount of waste, waste management is an extremely important issue. Utilising processes such as combustion and biological processing significantly decreases the accumulation and volume of waste. Despite this, huge volumes of resulting waste that still need to be managed remain. This paper identifies various methods of processing organic waste, discussing both thermal and biological techniques for waste management. Additionally, this paper demonstrates that the end products remaining after processing waste are oftentimes functional for agricultural use. These materials are excellent byproducts used to produce various organic, mineral and organomineral fertilisers. For instance, it appears that the production of fertilisers is the most promising method of utilising fly ash that results from the combustion of waste. In order to minimise the environmental risk of polluting soil with heavy metals, waste, as well as ashes resulting from combustion, must meet the crit... [more]
34056. LAPSE:2023.5077
Technological Advancements for the Detection of Antibiotics in Food Products
February 23, 2023 (v1)
Subject: Materials
Keywords: antibiotics, biosensors, capillary electrophoresis, chromatography, solid-phase extraction, surface-enhanced Raman scattering
Antibiotics, nowadays, are not only used for the treatment of human diseases but also used in animal and poultry farming to increase production. Overuse of antibiotics leads to their circulation in the food chain due to unmanaged discharge. These circulating antibiotics and their residues are a major cause of antimicrobial resistance (AMR), so comprehensive and multifaceted measures aligning with the One Health approach are crucial to curb the emergence and dissemination of antibiotic resistance through the food chain. Different chromatographic techniques and capillary electrophoresis (CE) are being widely used for the separation and detection of antibiotics and their residues from food samples. However, the matrix present in food samples interferes with the proper detection of the antibiotics, which are present in trace concentrations. This review is focused on the scientific literature published in the last decade devoted to the detection of antibiotics in food products. Various extr... [more]
34057. LAPSE:2023.5076
Influence of Modification of the Geometry of the Wave-Plate Mist Eliminators on the Droplet Removal Efficiency—CFD Modelling
February 23, 2023 (v1)
Subject: Modelling and Simulations
Keywords: Computational Fluid Dynamics, droplet removal efficiency, wave-plate mist eliminator
This study is concerned with droplet separation using wave-plate mist separators. The influence of continuous phase velocity, droplet size, and geometry on droplet removal efficiency has been investigated. The following modifications were analysed: drainage channel presence, length, angle, and modification to the streamlined shape. Furthermore, the influence of the physical parameters of the separated substances on separator efficiency was investigated. Calculations were conducted using computational fluid dynamics (CFD). The results were compared with the experimental data from the literature. Based on the results obtained, a new shape of drainage channels was proposed, which is characterised by high droplet removal efficiency with relatively low pressure drop.
34058. LAPSE:2023.5075
Novel One-Step Process for the Production of Bioplastic from Rapeseed Press Cake
February 23, 2023 (v1)
Subject: Biosystems
Keywords: graphene oxide composite, plasticizer-free process, protein-based bioplastic, rapeseed cake, valorization
Crude rapeseed cake was employed as the starting material for the preparation of protein-based bioplastic films through a wet process. A simple exposure of the agricultural waste to formic acid realized at 40 °C for 15 min could afford a slurry ready for producing robust bioplastic films by casting without another plasticizer addition. After determining the optimal process conditions, all films and membranes were successively characterized by DSC and FT-IR spectroscopy. They were also tested for their water absorption capacity, tensile strength, and elongation at break performance. The respective surface morphology and elementary composition of the products were determined by FE-SEM/EDX. Some attempts to improve their intrinsic properties were performed by loading graphene oxide inside the biopolymer three-dimensional matrix.
34059. LAPSE:2023.5074
Regulation of Eukaryote Metabolism: An Abstract Model Explaining the Warburg/Crabtree Effect
February 23, 2023 (v1)
Subject: Modelling and Simulations
Keywords: biological regulation networks, central carbon metabolism, Crabtree effect, discrete modeling, Fermentation, formal methods, regulation of cell metabolism, respiration, system dynamics, systems biology, Warburg effect
Adaptation of metabolism is a response of many eukaryotic cells to nutrient heterogeneity in the cell microenvironment. One of these adaptations is the shift from respiratory to fermentative metabolism, also called the Warburg/Crabtree effect. It is a response to a very high nutrient increase in the cell microenvironment, even in the presence of oxygen. Understanding whether this metabolic transition can result from basic regulation signals between components of the central carbon metabolism are the the core question of this work. We use an extension of the René Thomas modeling framework for representing the regulations between the main catabolic and anabolic pathways of eukaryotic cells, and formal methods for confronting models with known biological properties in different microenvironments. The formal model of the regulation of eukaryote metabolism defined and validated here reveals the conditions under which this metabolic phenotype switch occurs. It clearly proves that currently k... [more]
34060. LAPSE:2023.5073
Optimization Study on Increasing Yield and Capacity of Fluid Catalytic Cracking (FCC) Units
February 23, 2023 (v1)
Subject: Modelling and Simulations
Keywords: fluidized catalytic cracking, mechanism modeling, operation optimization
The fluidized catalytic cracking (FCC) unit is the primary production unit for gasoline and olefins in refineries. Improving product yield and processing capacity is closely related to the economic benefits of refineries. In this paper, we use the Aspen HYSYS software to model the mechanism of an 800 kt/a FCC unit in China. The simulation of the FCC unit based on the 21-lump models and the simulation results are in good agreement with the actual factory production data. Then we find out the optimization method to improve the product yield and processing capacity through the model research. The results of the study indicate the following optimization plans: when keeping the riser outlet temperature (ROT) in the range of 535~545 °C, it can increase the yield of gasoline and liquefied petroleum gas (LPG) by up to 5%; when keeping the riser outlet temperature (ROT) in the range of 510~520 °C, it can increase the yield of gasoline and diesel by up to 0.5%; the optimal ROT of control tempera... [more]
34061. LAPSE:2023.5072
A 3D Food Printing Process for the New Normal Era: A Review
February 23, 2023 (v1)
Subject: Food & Agricultural Processes
Keywords: 3D food printing, color jet printing, extrusion-based 3D printing, fused deposition modeling, selective laser sintering
Owing to COVID-19, the world has advanced faster in the era of the Fourth Industrial Revolution, along with the 3D printing technology that has achieved innovation in personalized manufacturing. Three-dimensional printing technology has been utilized across various fields such as environmental fields, medical systems, and military materials. Recently, the 3D food printer global market has shown a high annual growth rate and is a huge industry of approximately one billion dollars. Three-dimensional food printing technology can be applied to various food ranges based on the advantages of designing existing food to suit one’s taste and purpose. Currently, many countries worldwide produce various 3D food printers, developing special foods such as combat food, space food, restaurants, floating food, and elderly food. Many people are unaware of the utilization of the 3D food printing technology industry as it is in its early stages. There are various cases using 3D food printing technology i... [more]
34062. LAPSE:2023.5071
RSM-Based Preparation and Photoelectrocatalytic Performance Study of RGO/TiO2 NTs Photoelectrode
February 23, 2023 (v1)
Subject: Materials
Keywords: methylene blue, photoelectrocatalysis, response surface method, RGO/TiO2 NTs
In this paper, reduced graphene oxide (RGO) was prepared by a modified Hummers method and chemical reduction method, and an RGO/TiO2 NTs (RGO/TiO2 nanotubes) photoelectrode was prepared by the electrochemical deposition method. The as-prepared RGO/TiO2 NTs were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and their photocatalytic activities were investigated by measuring the degradation of methylene blue (MB) under simulated solar light irradiation. The SEM and XRD results indicated that the original tubular structure of TiO2-NTs was not changed after RGO modification. The surface of the TiO2 NTs photoelectrode was covered with a non-uniform, flake-shaped reduced graphene oxide film. The thickness of the RGO/TiO2 NTs was increased to about 22.60 nm. The impedance of the RGO/TiO2 NTs was smaller than that of the TiO2 NT photoelectrode. The optimal preparation conditions of RGO/TiO2 NT photoelectrodes were investigated by using a single factor method and re... [more]
34063. LAPSE:2023.5070
Simple Gain-Scheduled Control System for Dissolved Oxygen Control in Bioreactors
February 23, 2023 (v1)
Subject: Planning & Scheduling
Keywords: biotechnological cultivation process, dissolved oxygen concentration, gain-scheduling, mathematical model, PID (PI) control
An adaptive control system for the set-point control and disturbance rejection of biotechnological-process parameters is presented. The gain scheduling of PID (PI) controller parameters is based on only controller input/output signals and does not require additional measurement of process variables for controller-parameter adaptation. Realization of the proposed system does not depend on the instrumentation-level of the bioreactor and is, therefore, attractive for practical application. A simple gain-scheduling algorithm is developed, using tendency models of the controlled process. Dissolved oxygen concentration was controlled using the developed control system. The biotechnological process was simulated in fed-batch operating mode, under extreme operating conditions (the oxygen uptake-rate’s rapidly and widely varying, feeding and aeration rate disturbances). In the simulation experiments, the gain-scheduled controller demonstrated robust behavior and outperformed the compared conven... [more]
34064. LAPSE:2023.5069
Study of Biocrudes Obtained via Hydrothermal Liquefaction (HTL) of Wild Alga Consortium under Different Conditions
February 23, 2023 (v1)
Subject: Materials
Keywords: biocrude, biofuel, characterization, HTL, microalgae
Microalga-based fuels are promising solutions for replacing fossil fuels. This feedstock presents several advantages such as fast growth in a harsh environment and an ability to trap gases emitted from industries, thus reducing global warming effects. An efficient way to convert harvested microalgae into biofuels is hydrothermal liquefaction (HTL), which yields an intermediate product called biocrude. In this study, the elemental and molecular compositions of 15 different HTL biocrudes were determined by means of different techniques. Wild algae were cultivated in an industrial environment with plant emissions as a carbon source in fresh or seawater. It was notably observed that the culture medium had an influence on the biochemical composition and mineral matter content of algae. Thus, seawater algae were characterized by larger amounts of carbohydrates and mineral matter than freshwater ones, which also affected the oil yields and the light and heavy fractions of biocrudes.
34065. LAPSE:2023.5068
Combustion Efficiency in a Fluidized-Bed Combustor with a Modified Perforated Plate for Air Distribution
February 23, 2023 (v1)
Subject: Energy Systems
Keywords: combustion efficiency, fluidized-bed combustor, heat transfer, perforated plate, thermal efficiency
Combustion efficiency is one of the most important parameters especially in the fluidized-bed combustor. Investigations into the efficiency of combustion in fluidized-bed combustor fuels using solid biomass waste fuels in recent years are increasingly in demand by researchers around the world. Specifically, this study aims to calculate the combustion efficiency in the fluidized-bed combustor. Combustion efficiency is calculated based on combustion results from the modification of hollow plates in the fluidized-bed combustor. The modified hollow plate aims to control combustion so that the fuel incorporated can burn out and not saturate. The combustion experiments were tested using palm oil biomass solid waste fuels such as palm kernel shell, oil palm midrib, and empty fruit bunches. The results of the measurements showed that the maximum combustion temperature for the palm kernel shell fuel reached 863 °C for M1 and 887 °C for M2. The maximum combustion temperature measurements for M1... [more]
34066. LAPSE:2023.5067
Mono-, Bi-, and Tri-Metallic DES Are Prepared from Nb, Zr, and Mo for n-Butane Selective Oxidation via VPO Catalyst
February 23, 2023 (v1)
Subject: Materials
Keywords: deep eutectic solvent, electronic promoter, n-butane selective oxidation, structure directing agent, vanadium phosphorus oxide
In recent work, deep eutectic solvents (DESs) as ionic liquid analogues have been abundantly used in catalysis. Herein, vanadium phosphorus oxide (VPO) catalysts were synthesized from mono-, bi-, and tri- metallic DES of Nb, Zr, and Mo metal dopants as structure-directing agents and electronic promoters for n-butane selective oxidation towards maleic anhydride. Higher MA selectivity and larger n-butane conversion was successfully obtained using the newly developed catalysts, while oxidation by-product COx (CO, CO2) was minimized. Characterization techniques including FTIR, DSC, XRD, TEM, SEM, EDS, Raman spectroscopy, TGA, XPS, and NH3-TPD were employed to fully characterize the DESs, precursors and catalysts. This work led to an increase of 7.8% in MA mass yield with 16% more n-butane conversion as compared to an unpromoted VPO catalyst. Moreover, the utilization of a low-carbon alkane brought in a green impact on the chemical plant as well as the environment.
34067. LAPSE:2023.5066
Optimal Design of IPMSM for EV Using Subdivided Kriging Multi-Objective Optimization
February 23, 2023 (v1)
Subject: Optimization
Keywords: electric vehicle, fill blank, interior permanent magnet synchronous motor, kriging, multi-objective optimization
In this paper, subdivided kriging multi-objective optimization (SKMOO) is proposed for the optimal design of interior permanent magnet synchronous motor (IPMSM). The SKMOO with surrogate kriging model can obtain a uniform and accurate pareto front set with a reduced computation cost compared to conventional algorithms which directly adds the solution in the objective function area. In other words, the proposed algorithm uses a kriging surrogate model, so it is possible to know which design variables have the value of the objective function on the blank space. Therefore, the solution can be added directly in the objective function area. In the SKMOO algorithm, a non-dominated sorting method is used to find the pareto front set and the fill blank method is applied to prevent premature convergence. In addition, the subdivided kriging grid is proposed to make a well-distributed and more precise pareto front set. Superior performance of the SKMOO is confirmed by compared conventional multi... [more]
34068. LAPSE:2023.5065
Experimentally Calculated Study of the Effectiveness on the Process of Non-Catalytic Synthesis of Biodiesel in Reactors of Various Type
February 23, 2023 (v1)
Subject: Materials
Keywords: biodiesel, green chemistry, Modelling, rapeseed oil, renewable raw materials, subcritical methanol, transesterification
It was experimentally established that the dependence of the partial pressure of methanol on the molar fraction of methanol in oil shows a pronounced negative deviation from Raoul’s law, which significantly changes the idea of the influence of a large excess of methanol during non-catalytic synthesis of biodiesel. The efficiency of use of a molar excess of methanol is reduced as it grows, and with a more than 10-fold molar excess of the amount of reacted methanol, is practically constant. The comparison of biodiesel production processes in the range 220−235 °C showed that a slight change in the process temperature more effectively affects the biodiesel yield than an increase in the molar excess of methanol. A mathematical model of the process of transesterification of rapeseed oil in reactors of various types (batch and tubular reactors) is developed. A satisfactory correlation between the experimental and calculated data was observed. The calculation showed that the rate constants of... [more]
34069. LAPSE:2023.5064
Analysis of the Status and Improvement of Microalgal Phosphorus Removal from Municipal Wastewater
February 23, 2023 (v1)
Subject: Environment
Keywords: immobilization and recycle technology, microalgae, municipal wastewater, phosphorus removal
Phosphorus, as one of the main pollutants in municipal sewage, has received increasing attention recently. Phosphorus recovery also increases the sustainable development of municipal wastewater. Since algae have the ability to effectively redirect nutrients, including phosphorus, from municipal sewage to algae biomass, municipal sewage treatments involving microalgae have piqued the interest of many researchers. The phosphorus removal depends on the potential of the microalgae to absorb, preserve, or degrade phosphorus in municipal wastewater. It is, therefore, of great interest to study the mechanisms underlying the absorption, storage, and degradation of phosphorus by microalgae to ensure the viability of this phosphorus removal process in wastewater. The objectives of this review were to summarize phosphorus metabolism in microalgae, examine key external and internal factors impacting phosphorous removal by microalgae from wastewater, and examine the status of phosphorous-metabolism... [more]
34070. LAPSE:2023.5063
Machining of Inserts with PCD Cutting-Edge Technology and Determination of Optimum Machining Conditions Based on Roundness Deviation and Chip-Cross Section of AW 5083 AL-Alloy Verified with Grey Relation Analysis
February 23, 2023 (v1)
Subject: Materials
Keywords: AW 5083, cutting edge, EDM, grey relation analysis, grinding, laser, PCD, roundness deviation, turning
This paper describes the important significance of cutting-edge technology in the machining of polycrystalline diamond (PCD) cutting inserts by comparing the evaluation criteria. The LASER technology of cutting-edge machining is compared with grinding and electrical discharge machining (EDM) technologies. To evaluate the data from the experiments, the Grey Relational Analysis (GRA) method was used to optimize the input factors of turning to achieve the required output parameters, namely the deviation of roundness and chip cross-section. The input factors of cutting speed, feed rate, depth of cut and corner radius were applied in the experiment for three different levels (minimum, medium and maximum). The optimal input factors for turning of aluminum alloy (AW 5083) were determined for the factorial plan according to Grey Relational Grade based on the GRA method for the multi-criteria of the output parameters. The results were confirmed by a verification test according to the GRA method... [more]
34071. LAPSE:2023.5062
End-to-End Control Chart Pattern Classification Using a 1D Convolutional Neural Network and Transfer Learning
February 23, 2023 (v1)
Subject: Numerical Methods and Statistics
Keywords: 1D convolutional neural network, data augmentation, non-random pattern, SPC, transfer learning
Control charts are an important tool in statistical process control (SPC). They have been commonly used for monitoring process variation in many industries. Recognition of non-random patterns is an important task in SPC. The presence of non-random patterns implies that a process is affected by certain assignable causes, and some corrective actions should be taken. In recent years, a great deal of research has been devoted to the application of machine learning (ML) based approaches to control chart pattern recognition (CCPR). However, there are some gaps that hinder the application of the CCPR methods in practice. In this study, we applied a control chart pattern recognition method based on an end-to-end one-dimensional convolutional neural network (1D CNN) model. We proposed some methods to generate datasets with high intra-class diversity aiming to create a robust classification model. To address the data scarcity issue, some data augmentation operations suitable for CCPR were propos... [more]
34072. LAPSE:2023.5061
Numerical Simulation Prediction of Erosion Characteristics in a Double-Suction Centrifugal Pump
February 23, 2023 (v1)
Subject: Modelling and Simulations
Keywords: centrifugal pump, erosion, flow rate, impeller, particle concentration, particle track
The double-suction centrifugal pumps installed along the Yellow River in China face serious sediment erosion due to the high sediment content which causes the poor operation efficiency of the pump units. The particle motion characteristics and erosion characteristics in a pump under different flow rates and different particle concentrations were numerically simulated based on the particle track model of solid-liquid two-phase flow. The results show that the flow rate has a significant effect on the particle tracks and the erosion caused by the particles in the impeller. The total erosion rate is positively correlated with the flow rate, and increases with the increase in flow rate. The vortex and secondary flow in the impeller have obvious influence on the particle trajectory, which increases the particle concentration at the trailing edge of the pressure surface and intensifies the impact erosion in this area. The particles carried by the vortex intensifies the local erosion. The part... [more]
34073. LAPSE:2023.5060
Improving the Treatment Efficiency and Lowering the Operating Costs of Electrochemical Advanced Oxidation Processes
February 23, 2023 (v1)
Subject: Environment
Keywords: boron-doped diamond, EAOP®, electrochemical cell, gas diffusion electrode, hydrogen peroxide, ozonation, peroxone, wastewater treatment
Electrochemical advanced oxidation processes (EAOP®) are promising technologies for the decentralized treatment of water and will be important elements in achieving a circular economy. To overcome the drawback of the high operational expenses of EAOP® systems, two novel reactors based on a next-generation boron-doped diamond (BDD) anode and a stainless steel cathode or a hydrogen-peroxide-generating gas diffusion electrode (GDE) are presented. This reactor design ensures the long-term stability of BDD anodes. The application potential of the novel reactors is evaluated with artificial wastewater containing phenol (COD of 2000 mg L−1); the reactors are compared to each other and to ozone and peroxone systems. The investigations show that the BDD anode can be optimized for a service life of up to 18 years, reducing the costs for EAOP® significantly. The process comparison shows a degradation efficiency for the BDD−GDE system of up to 135% in comparison to the BDD−stainless steel electrod... [more]
34074. LAPSE:2023.5059
Effect of Tip Clearance Size on Tubular Turbine Leakage Characteristics
February 23, 2023 (v1)
Subject: Energy Systems
Keywords: clearance discipline, numerical calculation, tip leakage flow, tubular turbine
To study the effect of tip clearance on unsteady flow in a tubular turbine, a full-channel numerical calculation was carried out based on the SST k−ω turbulence model using a power-plant prototype as the research object. Tip leakage flow characteristics of three clearance δ schemes were compared. The results show that the clearance value is directly proportional to the axial velocity, momentum, and flow sum of the leakage flow but inversely proportional to turbulent kinetic energy. At approximately 35−50% of the flow direction, velocity and turbulent kinetic energy of the leakage flow show the trough and peak variation law, respectively. The leakage vortex includes a primary tip leakage vortex (PTLV) and a secondary tip leakage vortex (STLV). Increasing clearance increases the vortex strength of both parts, as the STLV vortex core overlaps Core A of PTLV, and Core B of PTLV becomes the main part of the tip leakage vortex. A “right angle effect” causes flow separation on the pressure si... [more]
34075. LAPSE:2023.5058
Multi-Level Optimization Process for Rationalizing the Distribution Logistics Process of Companies Selling Dietary Supplements
February 23, 2023 (v1)
Subject: Planning & Scheduling
Keywords: distribution logistics, inventory planning, multi-level optimization, transportation planning
The commission sales form is a very significant channel of sales today, which is especially true in the field of dietary supplements. In parallel, the prevailing digitalization trends have opened up further new opportunities for this form of distribution. The multi-level optimization process presented in the publication makes it possible to optimize the distribution logistics processes of companies producing food supplements at a high level by exploiting these new possibilities. The operation of the procedure is also illustrated through a practical example.
34076. LAPSE:2023.5057
Surface Roughness Prediction and Optimization in the Orthogonal Cutting of Graphite/Polymer Composites Based on Artificial Neural Network
February 23, 2023 (v1)
Subject: Materials
Keywords: brittle materials, graphite/polymer composites, machined surface quality, orthogonal cutting, roughness prediction and optimization
Graphite/polymer composites are brittle materials that are prone to producing cracks and concavities on machined surfaces, and their surface quality shows greater randomness. This work aims to overcome the large fluctuations in the machined surface quality of graphite/polymer composites, realize the prediction of machined surface roughness under different machining conditions and optimize the process parameters. A graphite/polymer composite material was cut orthogonally using different machining parameters, and the machined surface roughness of the cut samples was measured by a noncontact surface profiler to obtain training samples for Artificial Neural Network (ANN). In this study, a trained radial basis function neural network was used to predict the machined surface roughness, and the prediction accuracy was more than 93%. A Genetic Algorithm (GA) was used to optimize the established ANN, and then grey relational analysis was used to compare the accuracy of the GA optimization resul... [more]
34077. LAPSE:2023.5056
Interfacial Microstructure Analysis of AZ31 Magnesium Alloy during Plastic Deformation Bonding
February 23, 2023 (v1)
Subject: Materials
Keywords: AZ31 magnesium alloy, bonding, grain boundary, interfacial microstructure, plastic deformation
In this study, a plastic deformation process consisting of hot compression at 350 °C and heat treatment at 400 °C was performed to bond AZ31 magnesium alloy. Microstructural evolution around the bonding interface was systematically characterized to investigate the bonding process and clarify the bonding mechanism. When the plastic deformation strain reached 0.6, the bonding zone was full of fine dynamic recrystallized grains and the initial interface was eliminated. The post-heating treatments were conducted to achieve a sound interface bonding. The tensile tests and the corresponding fracture morphologies analysis indicated that the optimum holding time of heat treatment was 8 h. The interfacial bonding strength of the specimens holding for 8 h reached 164.7 MPa, an enhancement of about 9% compared with that of the specimens holding for 1 h. The microstructure analysis indicated that the bonding quality was affected by migration of the interfacial grain boundary (GB), the development... [more]
34078. LAPSE:2023.5055
Modified Dimension Reduction-Based Polynomial Chaos Expansion for Nonstandard Uncertainty Propagation and Its Application in Reliability Analysis
February 23, 2023 (v1)
Subject: Numerical Methods and Statistics
Keywords: dimension reduction, nonstandard distribution, polynomial chaos expansion, statistical moments, uncertainty analysis
This paper presents an algorithm for efficient uncertainty quantification (UQ) in the presence of many uncertainties that follow a nonstandard distribution (e.g., lognormal). Using the polynomial chaos expansion (PCE), the algorithm builds surrogate models of uncertainty as functions of a standard distribution (e.g., Gaussian variables). The key to build these surrogate models is to calculate PCE coefficients of model outputs, which is computationally challenging, especially when dealing with models defined by complex functions (e.g., nonpolynomial terms) under many uncertainties. To address this issue, an algorithm that integrates the PCE with the generalized dimension reduction method (gDRM) is utilized to convert the high-dimensional integrals, required to calculate the PCE coefficients of model predictions, into several lower-dimensional ones that can be rapidly solved with quadrature rules. The accuracy of the algorithm is validated with four examples in structural reliability ana... [more]
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