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Showing records 1043 to 1067 of 1817. [First] Page: 1 39 40 41 42 43 44 45 46 47 Last
An Integrated Design Method for Used Product Remanufacturing Process Based on Multi-Objective Optimization Model
Chao Ke, Yanxiang Chen, Muyang Gan, Yang Liu, Qunjing Ji
June 7, 2024 (v1)
Keywords: carbon emission, multi-objective optimization, remanufacturing process, turbine blade
The design for the remanufacturing process (DFRP) is a key part of remanufacturing, which directly affects the cost, performance, and carbon emission of used product remanufacturing. However, used parts have various failure forms and defects, which make it hard to rapidly generate the remanufacturing process scheme for simultaneously satisfying remanufacturing requirements regarding cost, performance, and carbon emissions. This causes remanufactured products to lose their energy-saving and emission-reduction benefits. To this end, this paper proposes an integrated design method for the used product remanufacturing process based on the multi-objective optimization model. Firstly, an integrated DFRP framework is constructed, including design information acquisition, the virtual model construction of DFRP solutions, and the multi-objective optimization of the remanufacturing process scheme. Then, the design matrix, sensitivity analysis, and least squares are applied to construct the mappi... [more]
Thermosonication Processing of Purple Onion Juice (Allium cepa L.): Anticancer, Antibacterial, Antihypertensive, and Antidiabetic Effects
Seydi Yıkmış, Berna Erdal, Caglar Doguer, Okan Levent, Melikenur Türkol, Nazan Tokatlı Demirok
June 7, 2024 (v1)
Subject: Biosystems
Keywords: antibacterial, anticancer, artificial neural network, purple onion, thermosonication
Onion (Allium cepa L.) juice is an important product used in gastronomy and food formulations. The first objective of this study was to optimize the content of bioactive compounds in purple onion juice (POJ) after the thermosonication process using response surface methodology (RSM) and artificial neural network (ANN) application models. Second, the anticancer, antibacterial, antihypertensive, and antidiabetic effects of POJ obtained after thermal pasteurization (P-POJ) or thermosonication (TS-POJ) were investigated after obtaining the ANN and RSM analysis reports. The optimization process for TS-POJ was carried out at 44 °C, for 13 min, with a 68% amplitude. The findings demonstrated that the angiotensin-converting enzyme (ACE) inhibition level was greater in TS-POJ samples than in the untreated control (C-POJ) sample (p > 0.05). C-POJ, TS-POJ, and P-POJ exhibited the inhibition of cell proliferation in vitro in a dose-dependent manner in lung (A549), cervical (HeLa), and colon cancer... [more]
Data-Based Modeling, Multi-Objective Optimization and Multi-Criteria Decision Making of a Catalytic Ozonation Process for Degradation of a Colored Effluent
Seyed Reza Nabavi, Saheleh Ghahri, Gade Pandu Rangaiah
June 7, 2024 (v1)
Keywords: acid red 88, Fe3O4 nano catalyst, multilayer perceptron, neural network, water treatment
In the catalytic ozonation process (COP), the reactions are complex, and it is very difficult to determine the effect of different operating parameters on the degradation rate of pollutants. Data-based modeling tools, such as the multilayer perceptron (MLP) neural network, can be useful in establishing the complex relationship of degradation efficiency with the operating variables. In this work, the COP of acid red 88 (AR88) with Fe3O4 nano catalyst was investigated in a semi-batch reactor and a MLP model was developed to predict the degradation efficiency () of AR88 in the range of 25 to 96%. The MLP model was trained using 78 experimental data having five input variables, namely, AR88 initial concentration, catalyst concentration, pH, inlet air flow rate and batch time (in the ranges of 150−400 mg L−1, 0.04−0.4 g L−1, 4.5−8.5, 0.5−1.90 mg min−1 and 5−30 min, respectively). Its optimal topology was obtained by changing the number of neurons in the hidden layer, the momentum and the le... [more]
Experimental Study on Pressure Oscillations of Direct-Contact Condensation between Saturated Steam and Droplets at Sub-Atmospheric Pressure
Yuanlin Jing, Chenhao Wang, Qunwu Huang, Yiping Wang, Yangyang Yu
June 7, 2024 (v1)
Subject: Environment
Keywords: direct-contact condensation, droplets, pressure oscillation, saturated steam, the auto power spectrum
In this paper, under the background of low-temperature steam waste heat recovery technology, the pressure oscillation characteristics of direct-contact condensation between continuously falling droplets and saturated steam at sub-atmosphere pressure were studied. An experimental device of pressure oscillation based on an acceleration oscillation sensor was established to investigate the influence of vapor pressure and fluid velocity on the oscillation characteristics of direct-contact condensation. The results showed that as the absolute pressure increases, the peak value of oscillation decreases gradually and the time-domain periodic waveform becomes fluctuating. When the liquid flow rate is low, the condensation oscillation shows a single-peak waveform and the dominant frequency moves towards a higher frequency. When the liquid velocity increases gradually, the RMS (root mean square) of pressure oscillation remains unchanged at first and then decreases obviously. The dominant frequen... [more]
The Reversible Transformation of a Vesicular Aggregate in Response to a pH Oscillation
Moeka Shimada, Risa Someya, Yasunao Okamoto, Daigo Yamamoto, Akihisa Shioi
June 7, 2024 (v1)
Keywords: pH oscillation, reversible deformation, vesicular aggregate
The transformation of amphiphilic molecular assemblies in response to chemical oscillations is fundamental in biological systems. The reversible transformation of a vesicular aggregate (VA) in response to a pH oscillation is presented in this study. A VA composed of the cationic surfactant didodecyldimethylammonium bromide is transformed using a pH oscillation ranging between 3 and 7. When the VA attains a stable structure at extreme pH values, the transformation reaches the irreversible stage. However, the addition of a phosphate buffer to the VA suspension changes the pH oscillation pattern from being rectangular to triangular and decreases the oscillation amplitude, successfully achieving the reversible transformation of the VA. Maintaining the non-equilibrium (transient) structures throughout the transformation and not falling into the equilibrium state with a varying pH are essential for the reversible transformation. This may be common and essential for dynamics in biological cel... [more]
Attention-Based Two-Dimensional Dynamic-Scale Graph Autoencoder for Batch Process Monitoring
Jinlin Zhu, Xingke Gao, Zheng Zhang
June 7, 2024 (v1)
Keywords: Batch Process, deep reconstruction-based contribution, dynamic characteristic, fault detection and diagnosis, graph attention network, two-dimensional modeling
Traditional two-dimensional dynamic fault detection methods describe nonlinear dynamics by constructing a two-dimensional sliding window in the batch and time directions. However, determining the shape of a two-dimensional sliding window for different phases can be challenging. Samples in the two-dimensional sliding windows are assigned equal importance before being utilized for feature engineering and statistical control. This will inevitably lead to redundancy in the input, complicating fault detection. This paper proposes a novel method named attention-based two-dimensional dynamic-scale graph autoencoder (2D-ADSGAE). Firstly, a new approach is introduced to construct a graph based on a predefined sliding window, taking into account the differences in importance and redundancy. Secondly, to address the training difficulties and adapt to the inherent heterogeneity typically present in the dynamics of a batch across both its time and batch directions, we devise a method to determine t... [more]
Polyelectrolyte Platforms with Copper Nanoparticles as a Multifunctional System Aimed at Healing Process Support
Agata Lipko, Anna Grzeczkowicz, Magdalena Antosiak-Iwańska, Marcin Strawski, Monika Drabik, Angelika Kwiatkowska, Ewa Godlewska, Ludomira H. Granicka
June 7, 2024 (v1)
Subject: Materials
Keywords: copper nanoparticles, human lung A549 cell line, polyelectrolyte layer coating
(1) Purpose: The aim of the study was to develop a nanocomposite with copper nanoparticles constituting a bacteriostatic surface to maintain human lung cell function. (2) Methods: A polyelectrolyte layer coating that incorporated copper nanoparticles was designed. As a bacteriostatic factor, copper nanoparticles were applied as a colloidal solution of copper nanoparticles (ColloidCuNPs) and a solution of copper nanoparticles (CuNPs). The influence of the polyelectrolytes on selected Gram (+) and Gram (−) strains was examined. The function and morphology of the human adenocarcinoma A549 cell line, comprising human epithelial lung cells cultured in the presence of nanocomposite layer coatings, were evaluated. We applied fluorescence and scanning electron microscopies, as well as flow cytometry, for these studies. Furthermore, the layer coating material was characterized by atomic force microscopy (AFM) and energy dispersive X-ray analysis (EDX). (3) Results: It was observed that the poly... [more]
Sugarcane Rapadura: Characteristics of the Oldest Historical Energy Food and Its Native Production Method
Ricardo Santos, Renata Assis, Raquel Freitas, Isabele Barbosa, Vânia Ceccatto
June 7, 2024 (v1)
Keywords: energy value, rapadura, sugarcane
is a well-recognized sugar-cane-derived product with a sweet, characteristic flavor and hard texture. This product is a cultural Brazilian landmark, particularly in Ceará, Brazil, where it is usually produced by small family businesses and consumed locally. This feature contributes to the difficulties of rapadura production standardization, a requirement for the global market. Against this backdrop, this study focuses on analyzing the centesimal composition and mineral content of rapadura. Six samples from different cities in Ceará were analyzed for moisture, ash, lipids, proteins, carbohydrates, energy value, and minerals. The results ranged from 6.42−11.74% for moisture, 0.23−1.12% for ash, 0.49−0.92% for protein, 85.18−89.12% for lipids, and 352.00−391.19 Kcal for energy value. Significant variations were observed between the samples, showing a lack of standardization in the production process. The analysis of micronutrients revealed low levels, with copper and iron standing out in... [more]
Exergy-Based Improvements of Sustainable Aviation Fuels: Comparing Biorefinery Pathways
Pablo Silva Ortiz, Silvio de Oliveira Jr, Adriano Pinto Mariano, Agnes Jocher, John Posada
June 7, 2024 (v1)
Subject: Environment
Keywords: biojet fuel production, biorefinery performance measurement, exergy and environmental assessment
The aeronautical sector faces challenges in meeting its net-zero ambition by 2050. To achieve this target, much effort has been devoted to exploring sustainable aviation fuels (SAF). Accordingly, we evaluated the technical performance of potential SAF production in an integrated first- and second-generation sugarcane biorefinery focusing on Brazil. The CO2 equivalent and the renewability exergy indexes were used to assess environmental performance and impact throughout the supply chain. In addition, exergy efficiency (ηB) and average unitary exergy costs (AUEC) were used as complementary metrics to carry out a multi-criteria approach to determine the overall performance of the biorefinery pathways. The production capacity assumed for this analysis covers 10% of the fuel demand in 2020 at the international Brazilian airports of São Paulo and Rio de Janeiro, leading to a base capacity of 210 kt jet fuel/y. The process design includes sugarcane bagasse and straw as the feedstock of the bi... [more]
Inhibition Localized Corrosion of N80 Petroleum Pipeline Steel in NaCl-Na2S Solution Using an Imidazoline Quaternary Ammonium Salt
Shanjian Li, Te Du, Guotao Cui, Haoxuan He, Panfeng Wu, Yongfei Li
June 7, 2024 (v1)
Subject: Materials
Keywords: corrosion inhibitor, imidazoline, N80 steel, occluded cell
In this paper, the local corrosion inhibition effect of imidazoline on N80 oil pipeline steel in a NaCl-Na2S solution was studied by the simulated blocking tank cell method, and the corrosion processes of the cathode and anode in the blocking zone were simulated. The blocking corrosion behavior of the pipeline tubing steel N80 in simulated corrosion solutions without and with different concentrations of an imidazoline corrosion inhibitor was studied by chemical analysis and electrochemical analysis. The results show that in the three solution systems, after the anode polarization of the occluded cell, the solution in the occluded region is acidified, the pH value decreases sharply, the migration of Cl− and S2− increases, and the concentration is increased in the blocked area. After adding the imidazoline corrosion inhibitor, the imidazoline inhibitor can reduce the migration of small-radius anions (Cl− and S2−) to the occluded area, inhibit the acidification of the solution in the occl... [more]
An Injection-Mold Based Method with a Nested Device for Microdroplet Generation by Centrifugation
Jichen Li, Wen Li, Bizhu Wu, Wenting Bu, Miaomiao Li, Jinyan Ou, Yuxiang Xiong, Shangtao Wu, Yanyi Huang, Yong Fan, Yongfan Men
June 7, 2024 (v1)
Subject: Other
Keywords: centrifuge-based, fluorescent hydrogel microspheres, injection molding, microdroplet generation
Microdroplets have been widely used in different fields due to their unique properties, such as compartmentalization, single-molecule sensitivity, chemical and biological compatibility, and high throughput. Compared to intricate and labor-intensive microfluidic techniques, the centrifuge-based method is more convenient and cost-effective for generating droplets. In this study, we developed a handy injection molding based method to readily produce monodisperse droplets by centrifugation. Briefly, we used two three-dimensional (3D) printed master molds with internal cavities to forge two coupled sub-molds by injecting polydimethylsiloxane (PDMS) and casted these two PDMS sub-molds into a nested structure that clamps the micro-channel array (MiCA) by injecting polyurethane resin. This method enables the generation of various sizes of monodispersed microdroplets by centrifugation with proper parameters within 10 min. To assess the performance of this method, homogeneous fluorescent hydroge... [more]
Hydrocarbon Gas Generation from Direct and Indirect Hydrogenation of Organic Matter: Implications from Hydrothermal Experiments
Kun He, Xiaomei Wang, Chunlong Yang, Shuichang Zhang
June 7, 2024 (v1)
Keywords: equilibrium isotope effect, hydrocarbon gases, hydrogenation, hydrothermal experiments, isotope fractionation
It is generally accepted that organic−inorganic interactions involving H-rich fluids (i.e., H2O and H2) contribute significantly to hydrocarbon (HC) generation in sedimentary basins. However, the effects of two hydrogenation processes involving H2O and H2 on the generation and C/H isotope fractionation of HC gases from organic matter (OM) remain unclear. In this study, two groups of hydrothermal experiments involving low-mature kerogen without (Group 1) and with FeS (Group 2) at 330−420 °C and 50 MPa were conducted to simulate the hydrogenation of OM by H2O and H2, respectively. The experimental results show that the redox reactions between H2O and FeS lead to the generation of considerable amounts of H2 in the Group 2 experiments. HC gas yield in the Group 2 experiments reaches 1.8−3.6 times that in the Group 1 experiments at Easy%Ro of 1.05−2.50%. In addition, indirect hydrogenation via H2O-derived H2 generates HC gases with smaller 13C fractionation and more negative δ2H compared wi... [more]
Correction: Ismaeil et al. Ameliorative Effect of Heat-Killed Lactobacillus plantarum L.137 and/or Aloe vera against Colitis in Mice. Processes 2020, 8, 225
Heba Ismaeil, Walied Abdo, Said Amer, Amin Tahoun, Diaa Massoud, Eatemad Zanaty, May Bin-Jumah, Ayman M. Mahmoud
June 7, 2024 (v1)
Subject: Biosystems
In the original publication [...]
Coke Substitution with Anthracite in Sintering Production
Pavlina Pustejovska, Michal Sikora, Simona Jursova, Kristyna Pustejovska, Edyta Kardas
June 7, 2024 (v1)
Subject: Materials
Keywords: anthracite, coke breeze, sintering
This article summarises the possibility of replacing the coke breeze sintering fuel with an economically and ecologically more suitable fuel, anthracite. The main focus is on the possibility of replacing coke breeze with anthracite, during which, the replacement process is accelerated and the other properties are also affected. The analyses performed showed that the replacement of coke breeze with different amounts of anthracite does not have a negative effect if the initial permeability of the sintering bed is the same.
Performance Evaluation on Open-Graded Friction Course Reinforced by Double-Adding Fibers Technology
Cihe Chen, Chimou Li, Saibang Zhang, Wenchang Liu, Hongwei Lin, Hongchao Zhang
June 7, 2024 (v1)
Subject: Materials
Keywords: asphalt mixture, fiber modification, glass fiber, lignin fiber, OGFC
The use of an open-graded friction course (OGFC) as a road surface demonstrates significant advantages in reducing driving noise and improving road drainage and safety. This study aims to enhance the overall performance of OGFC-13 by incorporating double-adding fiber technology. Laboratory tests were conducted on six OGFC-13 mixes modified with varying fiber ratios of lignin fibers (LFs) and glass fibers (GFs). Both GF and LF significantly improved high-temperature performance, with dynamic stability values increasing proportionally to GF content. The LF:GF = 0.15:0.15 ratio achieved peak shearing strength, demonstrating better improvement over single-fiber modification. Furthermore, both fibers effectively enhanced resistance to cracking, with GF-reinforced specimens excelling in bending stress and LF-reinforced specimens demonstrating the highest flexural strain. Water stability evaluations highlighted the substantial positive impact of LF and GF, with simultaneous addition resulting... [more]
Convective Hot Air Drying of Red Cabbage (Brassica oleracea var. Capitata Rubra): Mathematical Modeling, Energy Consumption and Microstructure
Antonio Vega-Galvez, Luis S. Gomez-Perez, Kong Shun Ah-Hen, Francisca Zepeda, Purificación García-Segovia, Cristina Bilbao-Sainz, Nicol Mejías, Alexis Pasten
June 6, 2024 (v1)
Subject: Materials
Keywords: convective drying, energy consumption, microstructure, Modelling, rehydration
This study examined the convective drying of red cabbage at temperatures ranging from 50 to 90 °C. Mathematical modeling was used to describe isotherms, drying kinetics and rehydration process. The effects of drying conditions on energy consumption and microstructure were also evaluated. The Halsey model had the best fit to the isotherm data and the equilibrium moisture was determined to be 0.0672, 0.0490, 0 0.0379, 0.0324 and 0.0279 g water/g d.m. at 50, 60, 70, 80 and 90 °C, respectively. Drying kinetics were described most accurately by the Midilli and Kuçuk model. Also, the diffusion coefficient values increased with drying temperature. Lower energy consumption was found for drying at 90 °C and the rehydration process was best described by the Weibull model. Samples dehydrated at 90 °C showed high water holding capacity and better maintenance of microstructure. These results could be used to foster a sustainable drying process for red cabbage.
Influence of the Trailing Edge Shape of Impeller Blades on Centrifugal Pumps with Unsteady Characteristics
Zhengkai Song, Yuxuan Chen, Tao Yu, Xi Wang, Haifeng Cao, Zhiqiang Li, Xiaopeng Lang, Simeng Xu, Shiyi Lu, Chenxing Jiang
June 6, 2024 (v1)
Keywords: centrifugal pump, dynamic mode decomposition, entropy generation rate analysis, pressure fluctuation, trailing edge
The flow field structure and pressure pulsation characteristics in two series of trailing edges of a centrifugal pump are investigated using the SST k-w turbulence model. Series 1 involves varying the impeller exit angle, and Series 2 involves varying the impeller exit shape. The entropy generation rate analysis method is used to evaluate the numerical simulation results. Vortex cores within the flow field are identified by applying the Ω criterion. The influence of different trailing edge configurations on the energy loss characteristics of the pumps is explored. The dynamic mode decomposition (DMD) method is used to analyze pressure pulsations at the volute considering unsteady flows in centrifugal pumps with different trailing edge shapes. The findings suggest that different trailing edge shapes can be used to adjust the energy loss proportions in various components of the pump. In Series 1, the efficiency remains nearly constant with changes in the outlet angle on both sides of the... [more]
A Transformerless Converter with Common-Mode Decoupling in Low-Voltage Hybrid Grids
Lei Wang, Xinfang Zhang, Xiaoqing Han, Yu Ren, Baifu Zhang, Peng Wang
June 6, 2024 (v1)
Keywords: common-ground-type, common-mode voltage, leakage current, low-voltage hybrid grids, transformerless converter
Compared with isolated converters, transformerless converters are a preferred choice in low-voltage grids due to their efficiency and lower cost. However, leakage current and common mode (CM) voltage appear through the converter and ground in hybrid grids, which consist of AC and DC subgrids. The leakage current and CM voltage seriously influence operation and power quality in low-voltage distribution systems. This paper proposes a common-ground-type (CGT) converter equipped with a CM decoupling control strategy to eliminate the leakage current and CM voltage. A CM model is derived, and the leakage current and CM voltage are analyzed in detail. A CGT four-leg converter is constructed to eliminate the high frequency CM voltage. A dual DQ current control loop is developed to suppress the DC double-frequency ripple. Additionally, an active damping method is proposed, based on the neutral current feed-forward plus inductor current feedback, to attenuate the low frequency CM voltage. The pr... [more]
Elimination of Shrinkage in Ductile Iron Castings Using Computer Simulation of Casting and Solidification
Peter Futas, Alena Pribulova, Vladimir Sabik, Jozef Petrik, Peter Blasko, Marcin Brzeziński
June 6, 2024 (v1)
Keywords: casting, computer simulation, feeder, foundry defects, gating system, shrinkage
The production of high-quality castings without foundry defects at minimal production costs is a constant priority for foundries. Innovation and optimization of production processes are key to achieving this goal. Computer simulation of foundry processes offers a modern alternative to expensive and time-consuming experiments in real foundries and provides a reliable representation and analysis of casting and solidification processes. A detailed analysis of the casting and solidification simulation results allows the prediction of various risks that can cause defects in cast castings, thereby reducing their quality and, last but not least, the cost of their production. This paper deals with the analysis of a computer simulation of the casting of a brake disc in a Slovak foundry. This brake disc has had shrinkages and micro shrinkages that reduce the internal quality of the casting. These defects occurred in the ribs in the upper part of the casting under the feeders. A computer simulati... [more]
A Novel Numerical Simulation Study of Air Leakage in Rotary Air Preheaters Based on Rotor Thermal Deformation
Yangfan Li, Hongqi Wei, Chenghao Fan, Weiwei Shi
June 6, 2024 (v1)
Keywords: air leakage gap, numerical simulation, radial air leakage, rotary air preheater, thermal deformation
Thermal deformation of the rotor is a critical factor leading to radial air leakage in rotary air preheaters. However, previous studies have not comprehensively established the correlation between rotor thermal deformation during thermal operation and radial air leakage. This study addresses this gap by introducing a novel model for calculating radial air leakage, incorporating the thermal deformation of the rotor. To achieve this, we selected a three-section rotary air preheater from a 330 MW coal-fired unit boiler for investigation. This research begins by constructing a heat transfer−structure coupled numerical simulation model using Fluent and ANSYS Workbench. This model is employed to analyze the thermal deformation of the rotor under varying unit power generation loads. This paper meticulously examines the thermal deformation patterns of the rotor in diverse circumstances, explores their impact on air leakages, and provides a comprehensive analysis of air leakage fluctuations in... [more]
Design and Sensitivity Analysis of Mechanically Actuated Digital Radial Piston Pumps
Keith Pate, James R. Marschand, Farid Breidi, Tawfiq Salem, John Lumkes
June 6, 2024 (v1)
Keywords: digital hydraulics, fluid power, pump design, variable displacement
One major challenge in fluid power is the improvement and optimization of the efficiency of mobile hydraulic systems. Conventional fluid power systems often exhibit relatively low overall efficiencies caused by inefficiencies in the various components, such as a prime mover, variable displacement pump, valves, fittings, hoses, and actuators. While each component contributes to the losses in the overall system, the pump converts the mechanical shaft energy from the prime mover to energy transmitted hydraulically and is one of the most crucial components impacting overall system efficiency. Using on/off technologies, new pump architectures have enabled the opportunity to increase the efficiency over conventional designs using positive sealing valves in place of conventional port plate designs. This work proposes, investigates, and assesses the development and optimization of a digital variable displacement pump using a novel cam actuation technique on radial piston pumps. The novelty of... [more]
Investigation on the Extent of Retrograde Condensation of Qianshao Gas Condensate Reservoir Using PVT Experiments and Compositional Reservoir Simulation
Hailong Liu, Bin Xie, Xiaozhi Xin, Haining Zhao, Yantian Liu
June 6, 2024 (v1)
Keywords: compositional reservoir simulation, equation of state, gas condensate reservoir, phase behavior, the extent of retrograde condensation
In the development of the Qianshao (QS) gas condensate reservoir, it is crucial to consider the phenomenon of retrograde condensation. Understanding the condensate saturation distribution with respect to time and space within the reservoir is essential for planning and implementing effective strategies for the future development of the QS gas condensate reservoir. In this paper, various PVT experiments (including reservoir oil recombination, flash separation, constant composition expansion, and constant volume depletion) were conducted to study the PVT properties and phase behavior of QS gas condensate fluid. Based on experimental data, our in-house PVT computation package was used to determine the appropriate EOS model parameters for the QS gas condensate. A four-step reservoir fluid characterization procedure and workflow for gas condensate reservoirs was developed. Furthermore, by analyzing the pressure-temperature phase envelope, the maximum possible condensate saturation in the QS... [more]
Corrosion Behavior and Mechanical Performance of Drill Pipe Steel in a CO2/H2S-Drilling-Fluid Environment
Yushan Zheng, Yuhan Zhang, Bingcai Sun, Bo Zhang, Sixi Zhang, Shuli Jin, Zhongling Xiao, Shengli Chu, Yinghua Jing, Zhi Zhang
June 6, 2024 (v1)
Subject: Materials
Keywords: CO2+H2 S, constant-load-stress corrosion, damage evaluation, drill pipe material, mechanical performance
Objectives: This article investigates the corrosion behavior and mechanical-property changes of S135, G105, and V150 drill pipe materials in a high-temperature-resistant, potassium amino poly-sulfonate drilling fluid, which has good lubrication performance and contains CO2/H2S, by applying an 80% yield-limit-load simulation. The results show that the CO2-corrosion behavior of G105, S135, and V150 drill pipes are obvious under the simulated constant-load-stress-corrosion environments at the wellhead, well-middle, and bottomhole positions. Compared to uncorroded drill pipes, S135 and V150 drill pipes have increased strength and yield ratios, decreased fracture elongation, and increased sensitivity to hydrogen embrittlement under H2S action, and V150 has a greater risk of stress-hydrogen embrittlement. The strength and yield ratios of G105-material drill pipes decrease, while the fracture elongation increases; the intensity-change amplitude levels are ranked V150 > G105 > S135, and the fr... [more]
Performance and Exhaust Emissions from Diesel Engines with Different Blending Ratios of Biofuels
Chengfang Mao, Jiewen Wei, Xuan Wu, Ananchai Ukaew
June 6, 2024 (v1)
Keywords: biodiesel, combustion, diesel engine, emissions, n-butanol, performance
Fossil fuel extraction and utilization are associated with several environmental issues. This study examined how altering the blending proportions of mixed diesel/biodiesel/n-butanol fuels impacts combustion. Additionally, it delved into the functioning of diesel engines when utilizing these blended fuels as well as conventional diesel. A three-dimensional fluid dynamics simulation was constructed and corroborated against test outcomes obtained at 25%, 50%, 75%, and 100% loads. The findings indicated that the n-butanol addition enhanced the indicated thermal efficiency. At a 100% load, D70B30 (70% diesel + 30% biodiesel), D70B25BU5 (70% diesel + 25% biodiesel + 5%N-butanol), D70B20BU10, and D70B10BU20 exhibited 4.76%, 5.75%, 6.79%, and 8.71% higher indicated thermal efficiency values than D100 (100% diesel), respectively. The introduction of butanol enhanced the combustion environment within the combustion chamber. Compared with pure diesel, all blended fuels reduced hydrocarbon and ca... [more]
Enzymatic Pretreatment of Slaughterhouse Wastewater: Application of Whole Lipolytic Cells of Rhizopus oryzae Produced from Residual Vegetable Oil
Willian S. M. Reis, Heitor B. S. Bento, Ana K. F. Carvalho, Ernandes B. Pereira
June 6, 2024 (v1)
Subject: Environment
Keywords: hydrolysis, lipase, whole cell
This study assessed the application of whole lipolytic cells in the pretreatment of slaughterhouse wastewater to reduce its lipid content. The fungal biomass of Rhizopus oryzae was evaluated in the hydrolysis of slaughterhouse wastewater containing high lipid concentrations, focusing on the biomass’s concentration and the effect of using an emulsifier and surfactant. The use of the whole-cells lipase of Rhizopus oryzae grown in a residual vegetable oil medium proved effective in the hydrolysis of slaughterhouse wastewater, generating concentrations of free fatty acids (FFA) ranging from 40.36 to 90.14 mM. The action of lipase in the hydrolysis of slaughterhouse residues indicated its effectiveness in pretreating lipid-rich liquid residues, potentially boosting the microbiota of this anaerobic treatment. The results showed that lipase activity without surfactant exhibited a similar performance to that of Triton X-100 in the hydrolysis of liquid residues. However, the combination of lipa... [more]
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