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Records Added in February 2023
Records added in February 2023
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12376. LAPSE:2023.0845
An Optimization Method for Distributing Emergency Materials Which Balances Multiple Decision Criteria
February 21, 2023 (v1)
Subject: Materials
Keywords: 4E decision criteria, COVID-19 pandemic, emergency material distribution, multi-criteria decision
In emergency rescue operations, it is very important for emergency management to arrange emergency materials scientifically and reasonably according to emergency needs. However, the decision criteria for emergency material distribution are often diverse, coupled with the lack of information acquisition due to the suddenness and development complexity of disasters, which makes the scientific decisions about emergency material distribution face great challenges. This paper proposes a multi-criteria decision optimization model of emergency material distribution under uncertainty that combines the 4E criteria of performance evaluation (economic criterion, efficiency criterion, effectiveness criterion and equity criterion). Then, the solution method of the multiple decision criteria model is designed. Finally, a case study of emergency medical material distribution during COVID-19 in China was conducted for model verification. The results show that different decision criteria have an import... [more]
12377. LAPSE:2023.0844
Analysis of Hydrothermal Solid Fuel Characteristics Using Waste Wood and Verification of Scalability through a Pilot Plant
February 21, 2023 (v1)
Subject: Environment
Keywords: biosolid fuel, hydrothermal carbonization, laboratory-scale, pilot-scale, solid fuel, waste wood
Increases in energy demand and waste are a major cause of natural resource depletion and environmental pollution, and technology capable of processing waste to convert it into energy is required to mitigate this issue. Hydrothermal carbonization (HTC) is an example of this technology that can convert waste into energy, and various studies have been conducted using it for fuel conversion. This study focused on the production of a solid fuel equivalent to coal for power generation through HTC processes using waste wood. Unlike previous work, which consists only of laboratory-scale HTC experiments, we confirmed scalability through pilot-scale HTC experiments. Overall, it was possible to convert waste wood into HTC solid fuel with a calorific value of over 27,000 kJ/kg through the pilot plant HTC process. Additionally, heavy metal and hazardous substance analyses proved that it can be used as a biosolid fuel.
12378. LAPSE:2023.0843
Numerical Investigation of the Flow Regime in the Vanes and the Torsional Self-Excited Vibration of Guide Vane in the Pump Mode of a Reversible Pump-Turbine
February 21, 2023 (v1)
Subject: Energy Systems
Keywords: guide vane, inter-vane flow, numerical simulation, pump-turbine, torsional self-excited vibration
Guide vanes (GVs) are installed between the runner and the stay vanes for flow guidance and discharge regulation in reversible pump-turbines. The unstable torsional self-excited vibration of the guide vane (GV) may occur when running at small guide vane opening angles during the transient operations involving pump flow. In addition, the double-stage radial vanes may induce complex flow in the vanes and influence the stability of torsional self-excited vibration of the guide vane. In this study, numerical simulations were conducted at small guide vane opening angles in pump mode for two different guide vanes based on the three-dimensional computational fluid dynamics (CFD) method. The flow regime with a deflection was formed on the trailing edge with a circle in the vaneless region that rotated reversely against the runner rotation when operating at smaller guide vane opening angles for both of the two guide vanes. Based on this, the coupling simulations based on the CFD method with a s... [more]
12379. LAPSE:2023.0842
Effects of Hydration during Drilling on Fracability of Shale Oil Formations: A Case Study of Da’anzhai Section Reservoir in Sichuan Basin, China
February 21, 2023 (v1)
Subject: Materials
Keywords: brittleness index, Da’anzhai shale, fracability index, fracture initiation pressure, hydration, shale oil reservoir
Accurate evaluation of shale oil reservoir fracability helps avoid blind fracturing and ensures efficient fracturing. However, the current evaluation of the fracability index rarely considers the impact of hydration caused by drilling fluid invasion during drilling. The results of a rock triaxial mechanical test conducted to evaluate the mechanical properties of shale oil reservoirs are reported in this paper. Based on the results, we developed a comprehensive evaluation method of shale oil reservoir fracability that considers hydration; the effects of the brittleness index, horizontal difference stress, and fracture toughness; and the law of water phase intrusion into shale oil reservoirs. The research results show that the average compressive strength decreased by 37.99%, the average elastic modulus decreased by 53.36%, and the average Poisson’s ratio increased by 68.75% after being soaked for 48.00 h at 80 °C and 30.00 MPa. The water saturation rate at the borehole wall was the high... [more]
12380. LAPSE:2023.0841
Application of Beetle Colony Optimization Based on Improvement of Rebellious Growth Characteristics in PM2.5 Concentration Prediction
February 21, 2023 (v1)
Subject: Optimization
Keywords: beetle swarm optimization, character decision, growth character, local optimum, rebellious character, test function
Aiming at the shortcomings of the beetle swarm algorithm, namely its low accuracy, easy fall into local optima, and slow convergence speed, a rebellious growth personality−beetle swarm optimization (RGP−BSO) model based on rebellious growth personality is proposed. Firstly, the growth and rebellious characters were added to the beetle swarm optimization algorithm to dynamically adjust the beetle’s judgment of the optimal position. Secondly, the adaptive iterative selection strategy is introduced to balance the beetles’ global search and local search capabilities, preventing the algorithm from falling into a locally optimal solution. Finally, two dynamic factors are introduced to promote the maturity of the character and further improve the algorithm’s optimization ability and convergence accuracy. The twelve standard test function simulation experiments show that RGP−BSO has a faster convergence speed and higher accuracy than other optimization algorithms. In the practical problem of P... [more]
12381. LAPSE:2023.0840
Where Reinforcement Learning Meets Process Control: Review and Guidelines
February 21, 2023 (v1)
Subject: Optimization
Keywords: imitation learning, Markov decision process, process optimization, transfer learning
This paper presents a literature review of reinforcement learning (RL) and its applications to process control and optimization. These applications were evaluated from a new perspective on simulation-based offline training and process demonstrations, policy deployment with transfer learning (TL) and the challenges of integrating it by proposing a feasible approach to online process control. The study elucidates how learning from demonstrations can be accomplished through imitation learning (IL) and reinforcement learning, and presents a hyperparameter-optimization framework to obtain a feasible algorithm and deep neural network (DNN). The study details a batch process control experiment using the deep-deterministic-policy-gradient (DDPG) algorithm modified with adversarial imitation learning.
12382. LAPSE:2023.0839
Comparison of the Preparation Process of Rare Earth Oxides from the Water Leaching Solution of Waste Nd-Fe-B Magnets’ Sulfate Roasting Products
February 21, 2023 (v1)
Subject: Materials
Keywords: double sulfates precipitation, Nd-Fe-B magnets, oxalic acid precipitation, rare earth, sodium carbonate precipitation
The new process developed here consisting of sulfurization roasting transformation and water immersion can effectively realize the separation of rare earth elements (REEs) and impurities from spent Nd-Fe-B magnets. For the industrial application of the new process, it is critical to determine how to economically and efficiently prepare rare earth oxide (RExOy) products with higher purity from the obtained water leaching solution. Therefore, according to rare earth sulfate (RE2(SO4)3) solution characteristics, the oxalic acid precipitation−calcination method, sodium carbonate precipitation−calcination method, and double sulfates precipitation−alkali conversion−calcination method were optimized and compared. The results show that the recovery efficiency of REE recovery via the oxalic acid precipitation−calcination method is 99.44%, and the purity of RExOy is 99.83% under optimal technological conditions. However, the cost of oxalic acid precipitation is higher. The process consisting of... [more]
12383. LAPSE:2023.0838
Multicomponent Comminution within a Stirred Media Mill and Its Application for Processing a Lithium-Ion Battery Slurry
February 21, 2023 (v1)
Subject: Energy Systems
Keywords: battery slurry, multicomponent comminution, silicon anode, stirred media mill
This study presents an approach for targeted comminution of component mixtures within a wet-operated stirred media mill. In the first step, a general understanding of the interactions between individual components on the grinding result with mixtures could be gained with basic experiments and following our former research work. In particular, a protective effect of the coarser particles on the fines could be elucidated. These findings were used to develop a process for the production of a battery slurry containing fine ground silicon particles as well as dispersed carbon black and graphite particles. By a tailored sample preparation applying a combination of particle dissolution and separation, the particle size distributions of carbon black and graphite particles were analyzed separately within the produced battery slurries. Based on the selective particle size analysis, the slurry preparation could be transferred from a complex multistage batch process using a dissolver to a stirred... [more]
12384. LAPSE:2023.0837
The Influence of Reservoir Clay Composition on Heavy Oil In Situ Combustion
February 21, 2023 (v1)
Subject: Energy Systems
Keywords: clays, combustion tube, heavy oil, in situ combustion, permeability, steam injection, thermal analysis
Thermally enhanced oil recovery methods, such as in situ combustion and steam injection, are generating considerable interest in terms of improving oil reserve exploitation and satisfying oil demand and economic growth. However, the early breakthrough of the in situ combustion front and the significant amount of heat loss associated with steam injection for deeper reservoir applications are the main challenges that require urgent solutions. Further data collection related to the effects of a reservoir’s physical and chemical properties, temperature, and pressure on in situ combustion front propagation and steam injection heat transfer inefficiency would be needed to achieve better reservoir oil recovery. Most studies have focused on the application of catalytic systems and the investigation of minerals’ effects on combustion front stabilization; however, the effect of clay interlayers’ minerals on the performance of in situ combustion is still poorly understood. This paper takes a new... [more]
12385. LAPSE:2023.0836
Temporal and Spatial Evolution Law of the Freezing Temperature Field of Water-Rich Sandy Soil under Groundwater Seepage: A Case Study
February 21, 2023 (v1)
Subject: Environment
Keywords: freezing temperature field, groundwater seepage, hydrothermal coupling, numerical calculation, temporal and spatial evolution, water-rich sandy soil
We aimed to assess the temporal and spatial evolution law of the freezing temperature field of water-rich sandy soil in underground freezing engineering, taking the newly built west ventilating shaft freezing engineering in the Yuandian No. 2 Mine of Huaibei Coalfield as the engineering background. The influence of groundwater seepage on the freezing temperature field was qualitatively analyzed using field measured data. Based on the mixture medium theory, a hydrothermal coupling numerical calculation model of the freezing temperature field was established. The temporal and spatial evolution law of the freezing temperature field of water-rich sandy soil was obtained via the analysis of field measured data and numerical calculation results. It was found that the proportion of water that froze into ice in the soil mass within the freezing pipe circle is more than that outside of the freezing pipe circle; thus, the phase change in the soil mass within the freezing pipe circle is highly ob... [more]
12386. LAPSE:2023.0835
A Review on Parallel Development of Flux Design and Thermodynamics Subject to Submerged Arc Welding
February 21, 2023 (v1)
Subject: Materials
Keywords: calphad, design model, material design, physicochemical properties
Submerged arc welding is a complex metallurgical process with a temperature of nearly 2000 ∘C (a temperature much higher than that in traditional steelmaking) and different phases, including flux (slag), metal, and plasma. Flux serves vital functions in order to produce the weld metal with desired qualities. It is well known that understandings of the thermodynamic properties regarding flux and slag are essential to aid in flux design and optimization. Actually, the developments of flux design and thermodynamics have been promoting each other. Within this review, the flux design stages have been documented and reviewed in detail from the perspective of thermodynamics. The thermodynamic design principles for fluxes have been evaluated systematically, the limitations of each flux have been elucidated, and the thermodynamic significance of the designed fluxes upon the development of welding thermodynamics has been analyzed. Based on the hypothesis that thermodynamic equilibrium is attaine... [more]
12387. LAPSE:2023.0834
Utilization of Carbon Dioxide via Catalytic Hydrogenation Processes during Steam-Based Enhanced Oil Recovery
February 21, 2023 (v1)
Subject: Energy Systems
Keywords: carbon dioxide hydrogenation, catalyst, CO2 utilization, heavy oil, in situ conversion of CO2, nickel tallate, upgrading
The concentration of carbon dioxide in the atmosphere has been increasing since immediately after the boom of industrialization. Novel technologies are required for carbon dioxide (CO2) capture, storage, and its chemical conversion into value-added products. In this study, we present a novel in situ CO2 utilization method via a hydrogenation process in the presence of nickel tallates during steam-based enhanced oil recovery. The light n-alkanes are the preferred products of in situ catalytic hydrogenation of CO2 due to their effective solubility, viscosity-reducing capacity, and hydrogen-donating capacity. A nickel tallate was evaluated for its carbon dioxide hydrogenation and oil-upgrading performance at 300 °C. The results showed that the content of saturated and aromatic fractions increased, while the content of heavier fragments decreased. Moreover, the relative content of normal C10−C20 alkanes doubled after the catalytic hydrogenation of CO2. Despite the noncatalytic hydrogenatio... [more]
12388. LAPSE:2023.0833
The Effect of Medical Device Regulations on Deploying a Lean Six Sigma Project
February 21, 2023 (v1)
Subject: Environment
Keywords: 21CFR 820, continuous improvement, ISO 13485, Lean Six Sigma, medical device, MedTech, validation
This paper investigates the differences in timelines involved in Lean Six Sigma (LSS) project deployment in a regulated industry versus in an unregulated one. Two case studies utilising Lean Six Sigma methods—in order to compare the transfer of manual manufacturing lines within a medical device and electronics manufacturing site—are discussed and utilised. This research aims to show the effects of regulatory procedures on LSS project implementation and timelines. This study particularly highlights how a regulatory environment can be a barrier, or bottleneck, to project management, continuous improvement, and engineering changes in the MedTech or medical device manufacturing industry. The results of this study represent an important first step towards a full understanding of the influence of regulations on operations in medical devices and, by extension, on pharmaceutical manufacturing industries on a global scale. The research limitations are that the data collected were from two speci... [more]
12389. LAPSE:2023.0832
Tertiary Wastewater Treatment Technologies: A Review of Technical, Economic, and Life Cycle Aspects
February 21, 2023 (v1)
Subject: Environment
Keywords: chlorination, constructed wetlands, life cycle assessment, microalgae, ozonation, technoeconomic, tertiary wastewater treatment
The activated sludge process is the most widespread sewage treatment method. It typically consists of a pretreatment step, followed by a primary settling tank, an aerobic degradation process, and, finally, a secondary settling tank. The secondary effluent is then usually chlorinated and discharged to a water body. Tertiary treatment aims at improving the characteristics of the secondary effluent to facilitate its reuse. In this work, through a literature review of the most prominent tertiary treatment methods, a benchmarking of their technical efficiency, economic feasibility, and environmental impact was carried out. The photo-Fenton method proved to be the most technically efficient process, significantly reducing the microbial load and pharmaceutical content (by 4.9 log and 84%, respectively) of the secondary effluent. Chlorination and UV irradiation exhibited the lowest treatment costs (0.004 EUR/m−3) and the lowest global warming potential (0.04 and 0.09 kg CO2eq. m−3, respectivel... [more]
12390. LAPSE:2023.0830
Research on Parameter Matching of the Asymmetric Pump Potential Energy Recovery System Based on Multi-Core Parallel Optimization Method
February 21, 2023 (v1)
Subject: Optimization
Keywords: energy recovery, multi-core CPU, multi-process parallel, serialization products, VAPP
Aiming at the parameters of the different displacements and related components of the variable-displacement asymmetric axial piston pump (VAPP) required by the energy-recovery system of excavator booms of different tonnages, a rapid multi-process parallel optimization method of complex hydraulic products based on a multi-core CPU was proposed for parameter matching. The parameter matching was used to reasonably select relevant parameters so that the excavator’s boom energy-recovery and utilization system can improve operational efficiency and energy-saving efficiency under the premise of satisfying the normal working conditions of the working mechanism, and achieving the purpose of serializing VAPP products. A multi-objective optimization model was put forward according to energy-saving efficiency and operational efficiency. First, the accuracy of the acceleration method of the CVODE, a solver for stiff and non-stiff ordinary differential equation (ODE) systems, was verified by a physi... [more]
12391. LAPSE:2023.0789
Waste Derived Biocomposite for Simultaneous Biosorption of Organic Matter and Nutrients from Green Straw Biorefinery Effluent in Continuous Mode Activated Sludge Systems
February 21, 2023 (v1)
Subject: Materials
Keywords: alum sludge, biochar, biocomposite, chemical oxygen demand, green straw biorefinery effluent, mesocarp fiber
The conventional disposal of green straws through burning can be eliminated in a biorefinery that converts them into a range of sustainable commercial products. However, this leads to the generation of green straw biorefinery effluent (GSBE). Green straw biorefineries discharge wastewater into the ecosystem that contains high concentrations of COD and NH4+−N. It is one of the most notable sources of visual pollution and disruption of aquatic life as well as public health that requires treatment prior to discharge. To improve the GSBE quality for environmental sustainability, the attainment of sustainable development goals 6, 9, and 14, “clean water and sanitation”, “inorganic and organic waste utilization for added values from material”, and “life below water” is very important. Therefore, the effectiveness of the continuous mode activated sludge (CMAS) system and the biocomposite-based−continuous mode activated sludge (SB-CMAS) system in the treatment of GSBE was investigated in this... [more]
12392. LAPSE:2023.0743
Deep Learning with Spatial Attention-Based CONV-LSTM for SOC Estimation of Lithium-Ion Batteries
February 21, 2023 (v1)
Subject: Modelling and Simulations
Keywords: deep learning, IOV, lithium-ion battery, SOC
Accurate estimation of the state of charge (SOC) is an indispensable part of a vehicle management system. The accurate estimation of SOC can ensure the safe and reliable operation of the vehicle management system. With the development of intelligent transportation systems (ITS), vehicles can not only obtain the dynamic changes inside the battery through sensors, but also obtain the traffic information around the vehicle through vehicle−road collaboration. In addition, the development of onboard graphic processing units (GPUs) and Internet of Vehicles (IOV) technology make the computing power of vehicles no longer limited by hardware, which makes neural networks applied to the intelligent control of vehicles. Aiming at the problem that the traditional network cannot effectively obtain the complex spatial information of sample attributes, we developed an attention-based CONV-LSTM module for SOC prediction based on a convolutional neural network (CNN) and a long short-term memory (LSTM) n... [more]
12393. LAPSE:2023.0762
Study of Solidifying Surplus Sludge as Building Material Using Ordinary Portland Cement
February 21, 2023 (v1)
Subject: Materials
Keywords: ordinary Portland cement, solidification, surplus sludge, unconfined compression strength
In an attempt to effectively utilize a multitude of surplus sludge from sewage treatment plants, ordinary Portland cement was used to solidify the dry surplus sludge as a building material. The dry surplus sludge and cement were mixed at different proportions with a certain dosage of water and then cured for 3−60 days at room temperature. The unconfined compression strength (RC) of solidified blocks was investigated with respect to the effects of the ratio of liquid to solid (Rl/S), surplus sludge dosage (DS), the dosage of sodium silicate (DNa2SiO3), and the proportion of fly ash (WF). The fabricated solidified blocks were characterized by scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), and X-ray Diffraction Analysis (XRD). The results demonstrated that RC at 60 days reduced obviously with the increase in Rl/s when Ds was given, whereas RC reduced with DS increased to 15.0 wt% from 5.0 wt% for solidified blocks. When DS was 5.0 wt%, RC of 28 days w... [more]
12394. LAPSE:2023.0742
A High-Throughput Screening Procedure (Py-Fe3+) for Enhancing Ethanol Production by Saccharomyces cerevisiae Using ARTP Random Mutagenesis
February 21, 2023 (v1)
Subject: Energy Systems
Keywords: Ethanol, ferric nitrate, pyruvate, Saccharomyces cerevisiae, tolerance engineering
is an important microbial organization involved in ethanol synthesis. Mutant strains that can withstand multiple pressures during this process are critical to the industrial development of biofuels. In this study, a dual high-throughput screening method of Triphenyl-2H-tetrazoliumchloride (TTC)-based macroscopic observation and the reaction of ferric nitrate with pyruvate (or pyruvate radical ion) in fermentation broth was used. Using this, an S. cerevisiae mutant library that could tolerate 381 g/L sucrose was established by ARTP random mutation and adaptive evolution to select the best strain; its ethanol yield was increased by an additional 20.48%; and the sucrose utilization rate was 81.64%. This method is specific to the selection of strains with increased ethanol production.
12395. LAPSE:2023.0737
Development of a ZrO2-Coating Technique by a Sol−Gel Process Assisted with Pre-Silica-Coating
February 20, 2023 (v1)
Subject: Materials
Keywords: coating, film, silica, sol–gel, zirconia
The development of techniques for coating thermistors with materials possessing excellent chemical resistance and electrical insulation characteristics is necessary to ensure their protection. The present work proposes a coating technique using zirconia (ZrO2), which has excellent chemical resistance and electrical insulation properties, based on initiating a sol−gel reaction of zirconium alkoxide in the presence of a ceramic substrate consisting of the common components of thermistors. The ZrO2 films on substrates were not damaged, even after annealing at 600 °C in air. Several ZrO2 particles were also deposited on the substrate. Pre-silica (SiO2)-coating the substrate, which was performed through a tetraethoxysilane (TEOS) sol−gel reaction, decreased the amount of ZrO2 particles and promoted the formation of thick ZrO2 films, as the reaction between the Zr butoxide and the alkoxyl groups of incompletely hydrolyzed TEOS on the substrate increased the affinity between the ZrO2 layer an... [more]
12396. LAPSE:2023.0828
Dual Input Fuzzy Logic Controllers for Closed Loop Hemorrhagic Shock Resuscitation
February 21, 2023 (v1)
Subject: Process Control
Keywords: closed-loop, control systems, fluid resuscitation, fluid resuscitation, fuzzy logic, hardware-in-loop, hemorrhagic shock
Hemorrhage remains a leading cause of preventable death in emergency situations, including combat casualty care. This is partially due to the high cognitive burden that constantly adjusting fluid resuscitation rates can require, especially in austere or mass casualty situations. Closed-loop control systems have the potential to simplify hemorrhagic shock resuscitation if properly tuned for the application. We have previously compared 4 different controller types using a hardware-in-loop test platform that simulates hemorrhagic shock conditions, and we found that a dual input—(1) error from target and (2) rate of error change—fuzzy logic (DFL) controller performed best. Here, we highlight a range of DFL designs to showcase the tunability the controller can have for different hemorrhage scenarios. Five different controller setups were configured with different membership function logic to create more and less aggressive controller designs. Overall, the results for the different controlle... [more]
12397. LAPSE:2023.0827
Life Cycle Energy Consumption and Greenhouse Gas Emissions Analysis of Primary and Recycled Aluminum in China
February 21, 2023 (v1)
Subject: Environment
Keywords: energy consumption, greenhouse gas emissions, Life Cycle Analysis, primary and recycled aluminum
Aluminum production is a major energy consumer and important source of greenhouse gas (GHG) emissions globally. Estimation of the energy consumption and GHG emissions caused by aluminum production in China has attracted widespread attention because China produces more than half of the global aluminum. This paper conducted life cycle (LC) energy consumption and GHG emissions analysis of primary and recycled aluminum in China for the year 2020, considering the provincial differences on both the scale of self-generated electricity consumed in primary aluminum production and the generation source of grid electricity. Potentials for energy saving and GHG emissions reductions were also investigated. The results indicate that there are 157,207 MJ of primary fossil energy (PE) consumption and 15,947 kg CO2-eq of GHG emissions per ton of primary aluminum ingot production in China, with the LC GHG emissions as high as 1.5−3.5 times that of developed economies. The LC PE consumption and GHG emiss... [more]
12398. LAPSE:2023.0826
Removal of Hydrophobic Organic Pollutants and Copper by Alginate-Based and Polycaprolactone Materials
February 21, 2023 (v1)
Subject: Materials
Keywords: Adsorption, alginate, anthracene, benzo[a]pyrene, chlorpyrifos, copper, organic matter, organic pollutants, polycaprolactone
Organic pollutants (OPs) and heavy metals are environmental toxicants associated with great concerns. Decontamination processes are urgent for both, and the possibility to achieve their simultaneous removal from polluted waters is highly interesting. Additionally, in many cases, the effect of organic matter in the removal process is overlooked and must be considered. This work aimed to study the potential of alginate-based and polycaprolactone (PCL) materials to remove OPs and copper ions in the absence and presence of organic matter. The OPs investigated were the polycyclic aromatic hydrocarbons anthracene and benzo[a]pyrene, and the pesticide chlorpyrifos, both hydrophobic compounds. Copper (II) ions were used as a model of heavy metals. Alginate-based spheres were prepared by gelation, and PCL microparticles were obtained by oil/water emulsion solvent evaporation. The materials with the highest efficiencies for OP removal from aqueous solutions were those with activated carbon and P... [more]
12399. LAPSE:2023.0825
Decision-Making Model of Mechanical Components in a Lean−Green Manufacturing System Based on Carbon Benefit and Its Application
February 21, 2023 (v1)
Subject: Environment
Keywords: carbon benefit, carbon efficiency, carbon emission, lean–green, process decision-making
The key to achieving low-carbon manufacturing is to effectively reduce the carbon emissions of production systems and improve carbon benefits. The use of lean and green tools aids in measuring the added value of products, and increases the efficiency and sustainability of production systems. To address this problem and verify that the synergetic relationship between lean and green innovation increases the efficiency and sustainability in production systems, a new low-carbon manufacturing evaluation indicator—carbon benefit—in lean manufacturing systems was discussed. A low-carbon decision-making model of multiple processes aiming at carbon benefit maximization, as well as the dynamic characteristics of carbon benefit and sustainable process improvements in a lean production system, was established. A case study of a certain satellite dish parts manufacturing line was introduced to analyze and verify the feasibility of the proposed model. After improvement, the processing time of unit p... [more]
12400. LAPSE:2023.0824
Gas Generation and Its Carbon Isotopic Composition during Pyrite-Catalyzed Pyrolysis of Shale with Different Maturities
February 21, 2023 (v1)
Subject: Materials
Keywords: carbon isotope, pyrite catalysis, shale pyrolysis, thermal maturity
In this study, two shale samples with different maturities, from Geniai, Lithuania (Ro = 0.7%), and Wenjiaba, China (Ro = 2.7%), were selected for open-system pyrolysis experiments at 400 °C and 500 °C, respectively. The generation of isotopic gases from the shales with different maturities was investigated, and the effects of pyrite catalysis on the carbon isotopic compositions were also studied. It was found that CO2, CH4 and their isotopic gases were the main gaseous products of the pyrolysis of both shales, and more hydrocarbon gases were generated from the low-maturity Geniai shale. The δ13C1 values fluctuated from −40‱ to −38‱, and δ13C2 showed higher values (−38‱~−34‱) for the Geniai shale. In addition, its δ13CCO2 values ranged from −28‱ to −26‱. Compared with the Geniai shale, lower δ13C1 values (−43‱~−42‱) and higher δ13CCO2 values (−19‱~−14‱) were detected for the Wenjiaba shale. As temperature increased, CH4 became isotopically lighter and C2H6 became isotopically heavier,... [more]

