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Showing records 1379 to 1403 of 43292. [First] Page: 1 53 54 55 56 57 58 59 60 61 Last
Defect Detection Algorithm for Battery Cell Casings Based on Dual-Coordinate Attention and Small Object Loss Feedback
Tianjian Li, Jiale Ren, Qingping Yang, Long Chen, Xizhi Sun
June 7, 2024 (v1)
Keywords: defect detection of battery cell casings, dual coordinate attention, low space ratio feature, small object feature, small object loss feedback
To address the issue of low accuracy in detecting defects of battery cell casings with low space ratio and small object characteristics, the low space ratio feature and small object feature are studied, and an object detection algorithm based on dual-coordinate attention and small object loss feedback is proposed. Firstly, the EfficientNet-B1 backbone network is employed for feature extraction. Secondly, a dual-coordinate attention module is introduced to preserve more positional information through dual branches and embed the positional information into channel attention for precise localization of the low space ratio features. Finally, a small object loss feedback module is incorporated after the bidirectional feature pyramid network (BiFPN) for feature fusion, balancing the contribution of small object loss to the overall loss. Experimental comparisons on a battery cell casing dataset demonstrate that the proposed algorithm outperforms the EfficientDet-D1 object detection algorithm,... [more]
Comparing Quality and Functional Properties of Protein Isolates from Soybean Cakes: Effect of De-Oiling Technologies
Giulia Cestonaro, Rodrigo Gonzalez-Ortega, Antonella L. Grosso, Ksenia Morozova, Giovanna Ferrentino, Matteo Scampicchio, Enrico Costanzo
June 7, 2024 (v1)
Subject: Biosystems
Keywords: alternative protein sources, functional properties, green extraction, oilseed co-products, solvent extraction
Driven by growing concerns about food supply and the environment, research on alternative protein sources has become increasingly important. In this context, de-oiled seed cakes, particularly soybean cakes, have emerged as a promising option. However, the conventional methods, such as organic solvent extraction, from which these cakes are obtained present several limitations. This study aims to evaluate the efficiency of supercritical fluid extraction (SFE) as an alternative method for de-oiling soybean seeds and obtaining related protein isolates. By using SFE for de-oiling, it was possible to achieve 19% more protein isolates from soybean cakes than the conventional de-oiling method using hexane. Moreover, protein isolates from the SFE de-oiled cake reported significantly improved (p < 0.05) emulsifying abilities and water absorption capacity. Gel electrophoresis and differential scanning calorimetry indicated the presence of a higher concentration of proteins in their native stat... [more]
Performance Evaluation of a Double-Helical-Type-Channel Reinforced Heat Sink Based on Energy and Entropy-Generation Analysis
Liyi He, Xue Hu, Lixin Zhang, Feng Chen, Xinwang Zhang
June 7, 2024 (v1)
Keywords: entropy generation, heat sinks, heat transfer enhancement, performance evaluation, ribs
Heat-transfer enhancement and entropy generation were investigated for a double-helical-type-channel heat sink with different rib structures set on the upper wall. Based on available experimental data, a series of simulations with various turbulence models were conducted to find the best numerical model. Five different rib structures were considered, which were diamond (FC-DR), rectangular (FC-RR), drop-shaped (FC-DSR), elliptic (FC-ER) and frustum (FC-FR). The research was carried out under turbulent flow circumstances with a Reynolds number range of 10,000−60,000 and a constant heat-flow density. The numerical results show that the thermal performance of the flow channel set with a rib structure is better than that of the smooth channel. FC-ER offers the lowest average temperature and the highest temperature uniformity, with a Nusselt number improvement percentage ranging from 15.80% to 30.77%. Overall, FC-ER shows the most excellent performance evaluation criteria and lowest augment... [more]
Fluent Integration of Laboratory Data into Biocatalytic Process Simulation Using EnzymeML, DWSIM, and Ontologies
Alexander S. Behr, Julia Surkamp, Elnaz Abbaspour, Max Häußler, Stephan Lütz, Jürgen Pleiss, Norbert Kockmann, Katrin Rosenthal
June 7, 2024 (v1)
Subject: Materials
Keywords: biocatalysis, data integration, electronic laboratory notebook, ontology, process simulation
The importance of biocatalysis for ecologically sustainable syntheses in the chemical industry and for applications in everyday life is increasing. To design efficient applications, it is important to know the related enzyme kinetics; however, the measurement is laborious and error-prone. Flow reactors are suitable for rapid reaction parameter screening; here, a novel workflow is proposed including digital image processing (DIP) for the quantification of product concentrations, and the use of structured data acquisition with EnzymeML spreadsheets combined with ontology-based semantic information, leading to rapid and smooth data integration into a simulation tool for kinetics evaluation. One of the major findings is that a flexibly adaptive ontology is essential for FAIR (findability, accessibility, interoperability, reusability) data handling. Further, Python interfaces enable consistent data transfer.
Point Source Capture of Methane Using Ionic Liquids in Packed Bed Absorbers/Strippers: Experimental and Modelling
Hamid Reza Rahimpour, Jafar Zanganeh, Behdad Moghtaderi
June 7, 2024 (v1)
Keywords: Absorption, equation of estate, henry’s law, ionic liquid, methane, ventilation air methane
Fugitive methane emissions from the mining industry, particularly so-called ventilation air methane (VAM) emissions, are considered among the largest sources of greenhouse gas (GHG) emissions. VAM emissions not only contribute to the global warming but also pose a significant hazard to mining safety due to the risk of accidental fires and explosions. This research presents a novel approach that investigates the capture of CH4 in a controlled environment using 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide [BMIM][TF2N] ionic liquid (IL), which is an environmentally friendly solvent. The experimental and modelling results confirm that CH4 absorption in [BMIM][TF2N], in a packed column, can be a promising technique for capturing CH4 from point sources, particularly the outlet streams of ventilation shafts in underground coal mines, which typically accounts for <1% v/v of the flow. This study assessed the effectiveness of CH4 removal in a packed bed column by testing va... [more]
Post-Production Finishing Processes Utilized in 3D Printing Technologies
Antreas Kantaros, Theodore Ganetsos, Florian Ion Tiberiu Petrescu, Liviu Marian Ungureanu, Iulian Sorin Munteanu
June 7, 2024 (v1)
Subject: Materials
Keywords: 3D printing, additive manufacturing, automation, industry applications, materials innovation, post-processing techniques, quality assurance, robotics in post-processing, surface finishing
Additive manufacturing (AM) has revolutionized production across industries, yet challenges persist in achieving optimal part quality. This paper studies the enhancement of post-processing techniques to elevate the overall quality of AM-produced components. This study focuses on optimizing various post-processing methodologies to address prevalent issues such as surface roughness, dimensional accuracy, and material properties. Through an extensive review, this article identifies and evaluates a spectrum of post-processing methods, encompassing thermal, chemical, and mechanical treatments. Special attention is given to their effects on different types of additive manufacturing technologies, including selective laser sintering (SLS), fused deposition modeling (FDM), and stereolithography (SLA) and their dedicated raw materials. The findings highlight the significance of tailored post-processing approaches in mitigating inherent defects, optimizing surface finish, and enhancing mechanical... [more]
Study on the Simplified Chemical Kinetic Combustion Mechanism of Mixed Methanol/PODE Fuel for Marine Diesel Engines
Changxiong Li, Yihuai Hu, Hao Guo
June 7, 2024 (v1)
Keywords: chemical kinetic combustion mechanism, clean alternative fuel, energy conservation and emission reduction, marine diesel engine, mixed methanol–PODE fuel
As a clean alternative fuel oil for marine engines, methanol has received increasing attention, but its low cetane number requires diesel ignition, which increases the difficulty of retrofitting existing engine fuel injection systems. Polymethoxy dimethyl ether (PODEn) is an ether fuel mixture whose chemical structural formula can be expressed as CH3O(CH2O)nCH3 (n≥2). PODE3 is the predominant component in the blend, and its properties are representative of the blend. PODE is a low-carbon fuel with a high cetane number and is easy to compression ignite, and, as such, can be used to ignite methanol in a marine diesel engine. This article explores the combustion mechanism of mixed methanol−PODE fuel using the characteristics of PODE that can be easily mixed with methanol for combustion. Taking methanol and PODE3 as representative fuels, the detailed combustion mechanism of PODE3 and the detailed combustion mechanism of methanol are simplified using a DRGEPSA (direct relationship graph wit... [more]
Automated Symbolic Processes for Dynamic Modeling of Redundant Manipulator Robots
Claudio Urrea, Daniel Saa, John Kern
June 7, 2024 (v1)
Keywords: dynamic symbolic models, mathematical programming, MATLAB/Simulink, MPC, redundant manipulator robots
In this study, groundbreaking software has been developed to automate the generation of equations of motion for manipulator robots with varying configurations and degrees of freedom (DoF). The implementation of three algorithms rooted in the Lagrange−Euler (L-E) formulation is achieved through the utilization of .m files in MATLAB R2020a software.This results in the derivation of a symbolic dynamic model for industrial manipulator robots. To comprehend the unique features and advantages of the developed software, dynamic simulations are conducted for two 6- and 9-DoF redundant manipulator robots as well as for a 3-DoF non-redundant manipulator robot equipped with prismatic and rotational joints, which is used to simplify the dynamic equations of the redundant prototypes. Notably, for the 6-DoF manipulator robot, model predictive control (MPC) is employed using insights gained from the dynamic model. This enables optimal control by predicting the future evolution of state variables: spe... [more]
Simulation of Ni2+ Chelating Peptides Separation in IMAC: Prediction of Langmuir Isotherm Parameters from SPR Affinity Data
Rachel Irankunda, Pauline Jambon, Alexandra Marc, Jairo Andrés Camaño Echavarría, Laurence Muhr, Laetitia Canabady-Rochelle
June 7, 2024 (v1)
Subject: Biosystems
Keywords: chromatography modeling, IMAC, metal chelating peptides, Simulation, sorption isotherm, SPR, transport dispersive model
Chromatography modeling for simulation is a tool that can help to predict the separation of molecules inside the column. Knowledge of sorption isotherms in chromatography modeling is a crucial step and methods such as frontal analysis or batch are used to obtain sorption isotherm parameters, but they require a significant quantity of samples. This study aims to predict Langmuir isotherm parameters from Surface Plasmon Resonance (SPR) affinity data (requiring less quantity of sample) to simulate metal chelating peptides (MCPs) separation in Immobilized Metal ion Affinity Chromatography (IMAC), thanks to the analogy between both techniques. The validity of simulation was evaluated by comparing the peptide’s simulated retention time with its experimental retention time obtained by IMAC. Results showed that the peptide affinity constant (KA) can be conserved between SPR and IMAC. However, the maximal capacity (qmax) must be adjusted by a correction factor to overcome the geometry differenc... [more]
Development of Thin-Layer Chromatography−Densitometric Procedure for Qualitative and Quantitative Analyses and Stability Studies of Cefazolin
Joanna Żandarek, Małgorzata Starek, Monika Dąbrowska
June 7, 2024 (v1)
Subject: Materials
Keywords: cefazolin, stability testing, TLC–densitometry, validation method
Cefazolin is a first-generation cephalosporin used to treat severe infections of the respiratory tract, urinary tract, skin, and soft tissues. This study presents the optimal conditions for the determination of cefazolin by thin-layer chromatography with densitometric detection. A chloroform−methanol−glacial acetic acid mixture (6:4:0.5, v/v/v) was selected as the mobile phase, while TLC silica gel 60F254 plates were used as the stationary phase. Next, the developed procedure was validated in accordance with ICH guidelines. The obtained results showed that the method is selective, precise, and accurate in a linearity range of 0.04−1.00 µg/spot (r > 0.99). Subsequently, qualitative and quantitative analyses of formulations containing cefazolin were performed. It was found that the amount of antibiotic is highly consistent with the content declared by manufacturers. The suitability of the developed method for stability testing under varying environmental conditions was also verified. It... [more]
Generation and Transmission Expansion Planning: Nexus of Resilience, Sustainability, and Equity
Dahlia Byles, Patrick Kuretich, Salman Mohagheghi
June 7, 2024 (v1)
Keywords: capacity expansion planning, energy equity, energy justice, generation and transmission expansion planning, generation expansion planning, resilience, social vulnerability, sustainable power grids, transmission expansion planning
The problem of power grid capacity expansion focuses on adding or modernizing generation and transmission resources to respond to the rise in demand over a long-term planning period. Traditionally, the problem has been mainly viewed from technical and financial perspectives. However, with the rise in the frequency and severity of natural disasters and their dire impacts on society, it is paramount to consider the problem from a nexus of resilience, sustainability, and equity. This paper presents a novel multi-objective optimization framework to perform power grid capacity planning, while balancing the cost of operation and expansion with the life cycle impacts of various technologies. Further, to ensure equity in grid resilience, a social vulnerability metric is used to weigh the energy not served based on the capabilities (or lack thereof) of communities affected by long-duration power outages. A case study is developed for part of the bulk power system in the state of Colorado. The f... [more]
Design, Construction, and Characterization of a Solar Photovoltaic Hybrid Heat Exchanger Prototype
Sandro Guadalupe Perez Grajales, Angel Horacio Hernández, David Juárez-Romero, Guadalupe Lopez Lopez, Gustavo Urquiza-Beltran
June 7, 2024 (v1)
Subject: Materials
Keywords: heat exchanger, PH/T, photovoltaic cell, thermal efficiency
In this experimental work, a prototype of a hybrid solar−thermal−photovoltaic (HE-PV/T) heat exchanger has been designed, built, and characterized, with rectangular geometry and 12 fins inside, to obtain better heat flow and higher performance in order to achieve a better heat transfer coefficient, reducing and optimizing the working area. The heat exchanger contains 12 photovoltaic cells connected in series, with an angle of inclination of approximately 18° towards the south and a surface area of 0.22 m2, smaller than those available on the market, which individually capture 147.05 W/m2 as a photovoltaic panel and 240 W/m2 as a solar collector. Mathematical models found in the literature from previous work were used for the electrical and thermal evaluations. The temperature of the PV cells was reduced to 13.2 °C and the thermal level of the water was raised to a temperature above 70 °C, with a photovoltaic−thermal coupling power of 307.11 W and a heat transfer coefficient of 5790 W/m... [more]
Challenges and Perspectives of the Conversion of Lignin Waste to High-Value Chemicals by Pyrolysis
Zhouqing Tan, Yuanyuan Li, Feifei Chen, Jiashu Liu, Jianxiong Zhong, Li Guo, Ran Zhang, Rong Chen
June 7, 2024 (v1)
Keywords: bio-oil, Biomass, catalyst, lignin, pyrolysis, tobacco stem waste
The pyrolysis process is a thermochemical conversion reaction that encompasses an intricate array of simultaneous and competitive reactions occurring in oxygen-depleted conditions. The final products of biomass pyrolysis are bio-oil, biochar, and some gases, with their proportions determined by the pyrolysis reaction conditions and technological pathways. Typically, low-temperature slow pyrolysis (reaction temperature below 500 °C) primarily yields biochar, while high-temperature fast pyrolysis (reaction temperature 700−1100 °C) mainly produces combustible gases. In the case of medium-temperature rapid pyrolysis (reaction temperature around 500−650 °C), conducted at very high heating rates and short vapor residence times (usually less than 1 s), the maximum liquid yield can reach up to 85 wt% (on a wet basis) or achieve 70 wt% (on a dry basis), with bio-oil being the predominant product. By employing the pyrolysis technique, valuable utilization of tobacco stem waste enriched with lign... [more]
A Novel Ensemble Machine Learning Model for Oil Production Prediction with Two-Stage Data Preprocessing
Zhe Fan, Xiusen Liu, Zuoqian Wang, Pengcheng Liu, Yanwei Wang
June 7, 2024 (v1)
Keywords: CEEMDAN algorithm, Machine Learning, oil production prediction, random forest algorithm, TCN-GRU-MA model
Petroleum production forecasting involves the anticipation of fluid production from wells based on historical data. Compared to traditional empirical, statistical, or reservoir simulation-based models, machine learning techniques leverage inherent relationships among historical dynamic data to predict future production. These methods are characterized by readily available parameters, fast computational speeds, high precision, and time−cost advantages, making them widely applicable in oilfield production. In this study, time series forecast models utilizing robust and efficient machine learning techniques are formulated for the prediction of production. We have fused the two-stage data preprocessing methods and the attention mechanism into the temporal convolutional network-gated recurrent unit (TCN-GRU) model. Firstly, the random forest (RF) algorithm is employed to extract key dynamic production features that influence output, serving to reduce data dimensionality and mitigate overfit... [more]
Constructing an Efficient Health Assessment Model for Drainage Network to Evaluate the Drainage Network in Zone A of Zhenjiang City
He Li, Yizhuo Wang, Yujie Luo, Chang Jiang, Ziheng Yang
June 7, 2024 (v1)
Keywords: external water, quality and efficiency improvement, sewage collection system, water quality and quantity
Aiming at the problem of low pollutant concentration in the sewage treatment plant due to external water intrusion into the sewage collection system, which in turn leads to low pollutant reduction efficiency. A sewage system in Zhenjiang City is taken as an example. Analyze the situation of external water intrusion in the sewage pipe network and determine the external water intrusion proportion based on the water quality and quantity method. First, the dry season flow rate of the sewage pipe is obtained according to the monitoring data of the flowmeter. Then, the key research areas are screened out based on the changes in the concentration of water quality characteristic factors. Furthermore, chemical oxygen demand and electrical conductivity are used as water quality characteristic indicators to characterize shallow groundwater and river water. In addition, the proportions of groundwater and river water intrusion in the sewage pipe network are quantitatively analyzed based on the chem... [more]
Study on Hydrogen Direct Injection in RNG Combustion under Various Ignition Timings for Power Generation in a Retrofitted Gas Engine
Meiqi Yu, Hongliang Luo, Beini Zhou, Yang Liu, Chang Zhai, Keiya Nishida, Jun-Cong Ge
June 7, 2024 (v1)
Keywords: combustion performance, gas engine, hydrogen direct injection, renewable natural gas
Renewable natural gas (RNG) is attractive for energy policy goals in the world. Therefore, a regional system is designed to explore RNG combustion for power generation in localities. This study investigates a direct injection (DI) engine fueled with hydrogen (H2) blended into the simulated renewable natural gas, which consists of 50% methane (CH4) and 50% carbon dioxide (CO2) in volume. In order to obtain higher efficiency, comparisons between DI and port fuel injection (PFI) of H2 addition were made. Then, the volume percentage of H2 was changed from 20% to 100% by keeping the volume ratio of CH4 and CO2 at 1:1. Finally, results of power output, brake mean effective pressure (BMEP), brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) were discussed. Results showed that in contrast to PFI, H2 DI injection could increase efficiency by 4%. Additionally, H2 DI could retard the MBT ignition timing at 5 °CA. Compared with CH4/CH4 + CO2 combustion, under stoichiometric... [more]
Adaptation of Symbolic Discrete Control Synthesis for Energy-Efficient Multi-Pocket Milling
Serkan Çaşka, Mete Özbaltan
June 7, 2024 (v1)
Keywords: computer numerical control machine, Energy Efficiency, multi-pocket milling, optimization algorithms, symbolic discrete controller synthesis
In engineering, cost minimization, especially in Computer Numerical Control (CNC) machining like pocket milling, is crucial. Existing tool path definition software often lacks optimization, particularly at critical starting and ending points. This study optimizes CNC machine tool paths for energy-efficient multi-pocket milling, utilizing the Symbolic Discrete Control Synthesis (SDCS) method for formal correctness. In our work, the tool path generation is formulated as a traveling salesman problem. We introduce a modeling framework to adapt SDCS to multi-pocket-milling processes, aiming to enhance precision and efficiency for potential cost savings, including energy and time, in engineering applications. This study reports experimental and comparative results, where comparative evaluations were made using metaheuristic algorithms. Our proposed approach improves CNC machining processes for multi-pocket milling. We experimentally evaluate our control algorithms and demonstrate and validat... [more]
Ongoing Multivariate Chemometric Approaches in Bioactive Compounds and Functional Properties of Foods—A Systematic Review
Milica Karadžić Banjac, Strahinja Kovačević, Sanja Podunavac-Kuzmanović
June 7, 2024 (v1)
Keywords: chemometrics, classification, food, non-parametric methods, regression
In this review, papers published in the chemometrics field were selected in order to gather information and conduct a systematic review regarding food science and technology; more precisely, regarding the domain of bioactive compounds and the functional properties of foods. More than 50 papers covering different food samples, experimental techniques and chemometric techniques were selected and presented, focusing on the chemometric methods used and their outcomes. This study is one way to approach an overview of the current publications related to this subject matter. The application of the multivariate chemometrics approach to the study of bioactive compounds and the functional properties of foods can open up even more in coming years, since it is fast-growing and highly competitive research area.
Seeking Optimal Extraction Method for Augmenting Hibiscus sabdariffa Bioactive Compounds and Antioxidant Activity
Athanasia Kourelatou, Theodoros Chatzimitakos, Vassilis Athanasiadis, Konstantina Kotsou, Ioannis Makrygiannis, Eleni Bozinou, Stavros I. Lalas
June 7, 2024 (v1)
Keywords: anthocyanins, antioxidants, Extraction, hibiscus, partial least squares analysis, polyphenols, principal component analysis, pulsed electric field, response surface methodology, ultrasonication
The dried flowers of Hibiscus sabdariffa (HS), available worldwide, have various applications in both non-medicinal and medicinal fields. The growing global interest in the health benefits of HS is linked to its potential prevention or management of non-communicable diseases. The aim of this research was to find the optimal extraction method that ensures the maximum yield of multiple beneficial bioactive components, such as polyphenols, anthocyanins, vitamin C, β-carotene, antioxidant activity, free radical scavenging activity DPPH and ferric reducing antioxidant power (FRAP). To this end, stirring, pulsed electric field, and ultrasound-assisted extraction were evaluated, either alone or in combination. Under optimized extraction conditions, the obtained extract exhibited an elevated total polyphenol content (37.82 mg of gallic acid equivalents/g dry weight (dw)), total anthocyanin content (610.42 μg of cyanidin equivalents/g dw), total carotenoids content (921.84 μg of β-carotene equi... [more]
The Application of Pipette-Tip and Magnetic Dummy-Template Molecularly Imprinted Solid-Phase Extraction Coupled with High-Performance Liquid Chromatography with Diode Array and Spectrofluorimetric Detection for the Determination of Coumarins in Cosmetic S
Andrea Špačková, Katarína Hroboňová, Michal Jablonský
June 7, 2024 (v1)
Subject: Materials
Keywords: coumarins, HPLC, molecularly imprinted polymers, personal care products, safety testing, solid-phase extraction
In this study, adsorbents based on molecularly imprinted polymers (MIPs) in two solid-phase extraction application forms, pipette tip and magnetic extraction, were used for the selective extraction of coumarins. The pipette-tip solid-phase extraction reduced solvent volumes; the magnetic MIP extraction was simple and effective for phase separation. Parameters affecting extraction, such as the amount of adsorbent, type of washing solvent, volume of the elution solvent, and extraction times for magnetic extraction, were optimized. The MIP-based adsorbents displayed high selectivity and extraction efficiency, resulting in recoveries ranging from 70.3 to 102.0% (RSD % less than 5.5%) for five coumarins under study, 6,7-dihydroxycoumarin-6-β-D-glucoside, coumarin, 7-methoxycoumarin, 6-methylcoumarin, and dicoumarol. The extracts were analyzed by high-performance liquid chromatography with diode array (DAD) and fluorescence (FLD) detectors, reaching limits of quantification of 0.5 and 0.9 µg... [more]
Life Cycle Assessment of Aviation Fuel Production from Steel-Industry Off-Gas
Lin Guo, Xiao Wang, Weili Yang, Jing Lv
June 7, 2024 (v1)
Subject: Environment
Keywords: ethanol to jet fuel, Fischer–Tropsch, greenhouse gas, life cycle assessment, process simulation, steel industry
The steel industry in China, the world’s largest, contributes to about 15% of the nation’s total carbon emissions. Instead of direct combustion, the technology of converting off-gas from the steel industry into liquid fuels not only enhances the added value of this byproduct but also helps alleviate carbon emissions. This study, for the first time, integrates the specific circumstances of China to evaluate the carbon emissions of Ethanol to Jet (ETJ) and Fischer−Tropsch to Jet (FTJ) fuel technologies utilizing Basic Oxygen Furnace Gas (BOFG) and Coke Oven Gas (COG) as feedstocks. Six cases were examined using Aspen Plus (V11) for mass and energy balance: Case 1: BOFG/ETJ, Case 2: BOFG/FTJ, Case 3: COG/ETJ, Case 4: COG/FTJ, Case 5: (COG + BOFG)/ETJ, and Case 6: (COG + BOFG)/FTJ. The analysis underscores that the FTJ pathway exhibits superior carbon reduction efficiency relative to ETJ. Compared to traditional petroleum-based aviation fuels (86.65 g CO2eq/MJ), the FTJ pathways utilizing... [more]
Strategies for Software and Hardware Compatibility Testing in Industrial Controllers
Marcus Rothhaupt, Lucas Vogt, Leon Urbas
June 7, 2024 (v1)
Keywords: compatibility, industrial controller, PLC, test automation
Mass customization, small batch sizes, high variability of product types and a changing product portfolio during the life cycle of an industrial plant are current trends in the industry. Due to an increasing decoupling of the development of software and hardware components in an industrial context, compatibility problems within industrial control systems arise more and more frequently. In this publication, a strategy concept for compatibility testing is derived and discussed by means of a literature review and applied research. This four-phase strategy concept identifies incompatibilities between software and hardware components in the industrial control environment and enables test engineers to detect problems at an early stage. By automating the compatibility test on an external I-PC, the test can be run both when new software is installed on the industrial controller and when the controller is restarted. Thus, changes to the components are constantly detected and incompatibilities a... [more]
Risk Analysis of Wellbore Instability of “Felt Layer” in Qiudong Sag Based on Monte Carlo Method
Ruixue Jia, Liang Zhu, Xiaoping Song, Jian Chen
June 7, 2024 (v1)
Subject: Other
Keywords: collapse pressure, Monte Carlo, reliability, stable borehole, uncertainty
Both domestic and international scholars have conducted in-depth research on wellbore stability issues. They have established various empirical models, analytical models, and numerical simulation methods. However, there is relatively little research on the impact of the uncertainty of input parameters on wellbore stability, and the understanding of this aspect remains unclear. To address this, this paper introduces a probability distribution method. It is based on a wellbore stability mechanical analytical model and, using reliability theory, establishes a method for evaluating wellbore instability risks. By employing the Monte Carlo random simulation method, this study investigates the sensitivity of input parameters to wellbore stability, clarifying that ground stress is the main controlling factor affecting wellbore stability. Combining the analysis of the “felt layer” ground stress profile, this study utilizes two-dimensional simulation experiments to validate the accurate determin... [more]
Physico-Chemical Characterization of Encapsulated Fennel Essential Oil under the Influence of Spray-Drying Conditions
Maja Repajić, Ivona Elez Garofulić, Nina Marčac Duraković, Marta Balun, Karla Cegledi, Ena Cegledi, Erika Dobroslavić, Verica Dragović-Uzelac
June 7, 2024 (v1)
Subject: Materials
Keywords: encapsulation, essential oil, Foeniculum vulgare Mill., gum arabic, maltodextrin, oil retention, powder, wall material, β-cyclodextrin
In this study, fennel essential oil (EO) was spray-dried, varying the wall material type (two-component blends of maltodextrin (MD), β-cyclodextrin (β-CD) and gum arabic (GA)), the wall material ratio (1:1, 1:3 and 3:1) and the drying temperature (120, 160 and 200 °C). A total of 27 powders were analyzed for their moisture content, solubility, hygroscopicity, bulk density and particle size, while powder recovery and oil retention were determined in terms of encapsulation efficiency. The morphology and chemical composition of the powder obtained under optimal conditions were additionally analyzed by scanning electron microscopy and gas chromatography-mass spectrometry. The results showed that all of the powders had generally good properties, exhibiting a low moisture content, high powder recovery and high oil retention. A 1:3 MD:GA mixture and a drying temperature of 200 °C were found to be optimal for the spray-drying of fennel EO, producing a powder with a low moisture content (3.25%)... [more]
Influence of the Rotation Speed on the Internal Flow Characteristics of an Aircraft Fuel Gear Pump
Boliang Xu, Qi Liu, Zuchao Zhu, Yongcao Gao, Chuancang Li, Yuanding Zhang
June 7, 2024 (v1)
Keywords: cavitation area, cavitation evolution, gear engagement, gear pump, rotation speed
A gear pump is a key rotary-displacement pump for aircraft fuel transportation in the aerospace industry. Due to the great ratio of power-to-weight condition demanded for gear pumps in aircraft fuel transportation systems, the parameter of the rotation speed is a matter of extreme concern affecting internal flow characteristics that determines the adverse effects of cavitation, fuel trapping, and vibration. However, the flow characteristics of an aircraft fuel gear pump influenced by the rotation speed have not been elaborated upon on yet. In this research, the flow characteristics of an aircraft fuel gear pump were studied by considering the influence of the rotation speed. An experiment for testing the external performance of an aircraft fuel gear pump was performed, and a corresponding numerical simulation of a gas−liquid two-phase flow was employed. Distributions of the velocity and pressure at the central cross-sections and their monitored transient developments were comparatively... [more]
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