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Records with Type: Published Article
2972. LAPSE:2023.36165
Application of Composite Biomaterials from Chinese Herbal Medicine in the Field of Bone Tissue Engineering
July 4, 2023 (v1)
Subject: Materials
Keywords: biomaterials, bone tissue engineering, Chinese herbal medicine, modernization of Chinese herbal medicine.
Research into bone tissue engineering is increasing with advances in biomaterials. Natural products of plant origin have exciting therapeutic effects through multiple targets. The purpose of this article is to review the outstanding performance of herbal-derived natural products in bone tissue engineering. We have categorized herbal-derived natural products that exert different effects in bone tissue engineering into osteogenic, vascular, chondrogenic, anti-inflammatory and antibacterial. Natural products of plant origin are readily available and can be combined with biomaterials as bioactive molecules to complement each other and provide additional opportunities for bone tissue engineering. Finally, we discuss the challenges and opportunities for the development of plant composite biomaterials for bone tissue engineering and highlight emerging strategies in this field.
2973. LAPSE:2023.36164
Mixing Transport Mechanism of Three-Phase Particle Flow Based on CFD-DEM Coupling
July 4, 2023 (v1)
Subject: Modelling and Simulations
Keywords: CFD-DEM coupling, lithium electric homogenate mixing, mixing transport, three-phase particle flow.
The mixing transport courses of three-phase particle flows exist in some industrial applications, such as metallurgy material extraction, lithium electric slurry dispersion, and material mixing in the high-end chemical industry. Its mixing transport mechanism is a fluid−structure coupling dynamic issues with intensive shear and nonlinear characteristics, making the real-time prediction of the flow field face challenges. To address the above problem, a bidirectional fluid−structure coupling three-phase particle flow dynamic model is built based on the coupled computational fluid dynamics and discrete element model (CFD-DEM) to explore the mixing transport mechanism. An interphase coupling solution method is utilized to solve the interaction effects of the fluid and particle. Research results illustrate that the proposed method modeling can well reveal the mixing transport mechanism of the three-phase particle flows. Due to the additive effects of stirring speed, stirring blade size, and... [more]
2974. LAPSE:2023.36163
Multi-Objective Optimization Design and Experimental Investigation for a Prismatic Lithium-Ion Battery Integrated with a Multi-Stage Tesla Valve-Based Cold Plate
July 4, 2023 (v1)
Subject: Energy Systems
Keywords: high current rate, liquid cold plate, multi-objective optimization design, multi-stage Tesla valve, NCGA algorithm.
High current rate charging causes inevitable severe heat generation, thermal inconsistency, and even thermal runaway of lithium-ion batteries. Concerning this, a liquid cooling plate comprising a multi-stage Tesla valve (MSTV) configuration with high recognition in microfluidic applications was proposed to provide a safer temperature range for a prismatic-type lithium-ion battery. Meanwhile, a surrogate model with the objectives of the cooling performance and energy cost was constructed, and the impact of some influential design parameters was explored through the robustness analysis of the model. On this basis, the multi-objective optimization design of the neighborhood cultivation genetic algorithm (NCGA) was carried out. The obtained results demonstrated that if the MSTV channel was four channels, the valve-to-valve distance was 14.79 mm, and the thickness was 0.94 mm, the cold plate had the most effective cooling performance and a lower pumping power consumption. Finally, the optim... [more]
2975. LAPSE:2023.36162
Designing a Turning Guide Vane Using CFD for an Economizer of a Non-Furnace Boiler
July 4, 2023 (v1)
Subject: Modelling and Simulations
Keywords: economizer, non-furnace boiler, pressure drop, temperature uniformity, turning guide vane.
Non-furnace boilers can improve the efficiency of industrial once-through boilers. However, temperature non-uniformity occurs in the economizer connected vertically to the boiler. Heat transfer performance is degraded by temperature non-uniformity. To solve this problem, a corbel was installed on the side wall of the economizer, and a baffle was installed on the transition duct. Consequently, although the thermal efficiency of the boiler was improved, significant temperature non-uniformity was still observed in the area upstream of the economizer. To address this issue, this study designed a turning guide vane (TGV) at the economizer inlet using computational fluid dynamics (CFD). First, CFD was performed for a case without a guide vane and a case with an existing baffle installed. By analyzing the streamlines obtained using CFD, two TGV designs were proposed. In the first design, guide vanes were installed along the desired streamline, and the concept of the existing TGV was followed.... [more]
2976. LAPSE:2023.36161
N-Substituted (Hexahydro)-1H-isoindole-1,3(2H)-dione Derivatives: New Insights into Synthesis and Characterization
July 4, 2023 (v1)
Subject: Materials
Keywords: anti-oxidant activity, hexahydrophthalimides, molecular docking, pharmacokinetics and pharmacodynamic profiles, phthalimides.
Novel phthalimide derivatives, namely N-(1,3-dioxoisoindolin-2-yl)-2-(2-methyl-4-oxoquinazolin-3(4H)-yl)acetamide (1a) and N-(1,3-dioxoisoindolin-2-yl)thiophene-2-carboxamide (1b), and hexahydrophthalimide derivative N-(1,3-dioxohexahydro-1H-isoindol-2(3H)-yl)-2-(2-methyl-4-oxoquinazolin-3(4H)-yl)acetamide (2), have been synthesized. The phthalimide derivatives were synthesized from phthalic anhydride and 2-(2-methyl-4-oxoquinazolin-3(4H)-yl)acetohydrazide or thiophene-2-carbohydrazide, and the hexahydrophthalimide derivative has been synthesized from hexahydrophthalic anhydride and 2-(2-methyl-4-oxoquinazolin-3(4H)-yl)acetohydrazide. The chemical structures of the compounds are elucidated by Nuclear Magnetic Resonance (NMR) and Infrared (IR) spectra. The new in vitro antioxidant activities of the obtained substances were evaluated using the DPPH method. All tested compounds showed antioxidative activity, the most active compound being 1b. Bioinformatics tools were used for the predict... [more]
2977. LAPSE:2023.36160
The Combustion of Forest Humus Blended with Low-Rank Coal: Effects of Oxygen Ratio and Blending Ratio
July 4, 2023 (v1)
Subject: Energy Systems
Keywords: co-combustion, Coal, humus, kinetics, synergistic effect.
In this study, the combustion characteristics of pine needles, pine needle humus, and the co-combustion of these two types of biomass with coal were compared. In addition, the optimization of the combustion performance of coal/humus was assisted through the following studies: (i) the combustion performance of coal/pine needle humus was studied under four different oxygen concentrations (N2, 10%O2/90%N2, 20%O2/80%N2, and 40%O2/60%N2); (ii) the synergistic effect between the humus and coal during combustion was also investigated by adjusting the blending ratio and oxygen content; (iii) the mechanisms of the optimized combustion processes were expounded by kinetics and thermodynamics discussion. The results demonstrated that the combustion characteristics of the coal/humus blends were found to be higher than those of the coal/pine needle blends. The coupling interactions of the oxygen content and blending ratio contributed to the significant synergistic effect between the two fuels, and t... [more]
2978. LAPSE:2023.36159
Gas/Liquid Operations in the Taylor-Couette Disc Contactor: Continuous Chemisorption of CO2
July 4, 2023 (v1)
Subject: Process Operations
Keywords: chemisorption, continuous process, gas/liquid, multiphase, Taylor-Couette flow.
Gas/liquid contactors are widely used in chemical and biotechnological applications. The selection and design of bubble-column-type gas/liquid contactors requires knowledge about the gas distributor design to provide appropriate gas flow patterns. This study presents the continuous chemisorption of CO2 in 0.1 molar sodium hydroxide solution in a counter currently operated gas/liquid Taylor-Couette disc contactor (TCDC). This vertical-column-type contactor is a multi-stage agitated gas/liquid contactor. The performance of a lab-size TCDC contactor in gas/liquid mass transfer operations was investigated. The apparatus design was adjusted for gas/liquid operations by installing perforated rotor discs to provide a rotational-speed-dependent dispersed gas phase holdup in the column. The parameters of dispersed gas phase holdup, volumetric mass transfer coefficient and residence time distribution were measured. In the first step, hydraulic characterization was performed. Then, the efficiency... [more]
2979. LAPSE:2023.36158
Control for a Class of Unstable High-Order Systems with Time Delay Based on Observer−Predictor Approach
July 4, 2023 (v1)
Subject: Process Control
Keywords: linear delay systems, observers, PID controller, stabilization.
This work considers the stabilization of a high-order system with time delay; an observer−predictor scheme is designed to estimate an internal signal of the system that is not available for measurement: this internal signal is the output before being delayed. By using the estimated signal, it is possible to design a controller for the delay-free system. The key point to carrying out this estimation strategy is to obtain conditions assuring that the estimated signal converges to the internal variable of the system. A necessary and sufficient condition to achieve an appropriate convergence in the proposed observer−predictor scheme is given. In addition, an analysis of the disturbance rejection and robustness with respect to the delay term is provided. The correct functioning of this scheme is verified through an example.
2980. LAPSE:2023.36157
Preserving the Internal Quality of Quail Eggs Using a Corn Starch-Based Coating Combined with Basil Essential Oil
July 4, 2023 (v1)
Subject: Food & Agricultural Processes
Keywords: consumer acceptability, food safety, microbiological quality.
The objective of the study is to evaluate a new proposal for a coating based on corn starch (CS) enriched with basil essential oil (BEO) to overcome the rapid deterioration of quail eggs under nonrefrigerated conditions. One hundred and seventy-one quail eggs were divided into treatments of uncoated eggs (control), eggs coated with CS, and eggs coated with CS/BEO, and analyzed over four weeks at room temperature. The CS/BEO coating reduced the growth of total aerobic mesophilic bacteria, Enterobacteriaceae, molds, and yeasts on the surface of eggshells to <2 log10 CFU/mL compared to the control treatment at week four storage. The average Haugh unit (HU) of the four weeks of storage of the CS/BEO treatment was notably higher compared to the control. There was no significant difference between the sensory parameter scores of coated eggs and control treatment. Based on the findings, the CS/BEO coating can be used to mitigate the contamination of quail eggs and preserve their internal q... [more]
2981. LAPSE:2023.36156
A Green Approach of Utilising Banana Peel (Musa paradisiaca) as Adsorbent Precursor for an Anionic Dye Removal: Kinetic, Isotherm and Thermodynamics Analysis
July 4, 2023 (v1)
Subject: Biosystems
Keywords: biosorption, Evans blue dye, non-linear regression, thermodynamics.
Methods for removing pollutants include membrane isolation, ion exchange, precipitation, transformation, and biosorption. Adsorption is a cost-effective method of treating industrial wastewater and a common commercial method for concentrating valuable molecules or eliminating contaminants. Banana peel is one of the largest underutilized agricultural wastes in Malaysia. A novel method of using a low-cost biosorbent made from banana peel and Evans blue (EB) dye as a target is the target of this study. The optimal conditions for EB dye adsorption occurred at a dye concentration of 200 mg/L, adsorbent dosages between 10 and 20 g/L, temperature of 25 °C, incubation time of 180 min, and agitation speeds of 100 rpm. Statistical discriminatory analysis showed that the pseudo-second-order kinetic model and the Redlich−Petersen isotherm model were the best models. The maximum adsorption capacity based on Langmuir’s isotherm prediction was 58.51 mg g−1. A non−linear regression of the thermodynami... [more]
2982. LAPSE:2023.36155
A Review on Process-Based Groundwater Vulnerability Assessment Methods
July 4, 2023 (v1)
Subject: Modelling and Simulations
Keywords: groundwater vulnerability assessment, pollution transport, transport simulation, unsaturated zone.
The unreasonable development and pollution of groundwater have caused damage to the groundwater system and environmental problems. To prevent this, the concept of “groundwater vulnerability” was proposed, and various evaluation methods were developed for groundwater protection. However, with changing climatic conditions and human activities, groundwater vulnerability is now emphasizing physical processes. This study aims to review and analyze the principles and applications of process-based groundwater vulnerability methods to achieve the source protection of groundwater resources. It introduces the assessment method and elaborates on pollutant migration processes and numerical simulation technology. Relevant articles from the past 30 years are reviewed to show the evolution of process-based groundwater vulnerability assessment. The study also discusses current research trends and proposes future development paths. It concludes that process-based groundwater vulnerability assessment wi... [more]
2983. LAPSE:2023.36154
Enhancement of Electrochemical−Anaerobic Digested Palm Oil Mill Effluent Waste Activated Sludge in Solids Minimization and Biogas Production: Bench−Scale Verification
July 4, 2023 (v1)
Subject: Process Design
Keywords: anaerobic digestion, biogas, electrochemical, palm oil mill effluent, solids minimization, specific energy, waste activated sludge.
The development of the palm oil industry has induced the generation of palm oil mill effluent (POME) together with its waste activated sludge (WAS) in recent years. This study aims to discover new opportunities in treating POME WAS that has high organic content with low degradability but having potential in converting waste into energy. The optimized electrochemical oxidation (EO) of pre-treated WAS was applied prior to anaerobic digestion (AD) to improve the POME WAS digestibility (by assessing its solids minimization and biogas production) under mesophilic conditions at 30 ± 0.5 °C and solids retention time of 15 days. The enhancement in sludge minimization was verified, with 1.6-fold over the control at steady-state. Promising results were obtained with a total chemical oxygen demand (COD) removal of 68.8% with 11.47 mL CH4/g CODadded in pre-treat digester, compared with 37.1% and 3.9 mL CH4/g CODadded in control digester. It is also worth noting that the specific energy (SE) obtain... [more]
2984. LAPSE:2023.36153
Abnormal Situation Management in Chemical Processes: Recent Research Progress and Future Prospects
July 4, 2023 (v1)
Subject: Modelling and Simulations
Keywords: abnormal situation management, chemical process, digital twin system, dynamic risk assessment, early prediction and warning, fault detection and diagnosis, industrial application, intelligence, root cause analysis.
In the chemical process, abnormal situations are precursor events of incidents and accidents. Abnormal situation management (ASM) can effectively identify abnormalities and prevent them from evolving into incidents or accidents, ensuring the safe and smooth operation of chemical plants. In recent years, ASM has attracted extensive attention from the process industry and from academia, and a lot of research work has been conducted. However, the intelligence level of ASM in actual chemical plants is still relatively low, and industrial applications still face many difficulties and challenges. This review first summarizes the concepts and involved in the contents of ASM. Then, the latest research progress in various aspects of ASM is systematically reviewed. Finally, the challenges and future research directions of ASM are analyzed based on the perspective of industrial application. This review aims to provide the most cutting-edge reference for follow-up research on ASM, and to promote t... [more]
2985. LAPSE:2023.36152
Study on Adsorption and Photocatalytic Properties of Zinc Ferrite
July 4, 2023 (v1)
Subject: Materials
Keywords: Adsorption, amido black 10B, methyl orange, methylene blue, photocatalysis, zinc ferrite.
In this study, methyl orange, methylene blue, and amido black 10B were removed as target dyes using purified, synthetic, and purchased zinc ferrite as adsorbents and photocatalysts. The highest removal rates of amido black 10B by these adsorbents ranged from 81.62% to 88.33%. The removal rate of methyl orange was approximately 1%, and the removal rate of methylene blue was approximately 2%. Hence, an investigation was conducted to elucidate the factors that influence the removal efficacy of purified zinc ferrite on amido black 10B. Titanium dioxide prepared at different calcination temperatures was unsuccessful in removing amido black 10B, but the physical mixing of titanium dioxide prepared at suitable calcination temperatures with purified zinc ferrite had a positive effect on amido black 10B removal. Since zinc ferrite could not be used as an adsorbent to remove methyl orange and methylene blue, the photocatalytic degradation properties of zinc ferrite and its influencing factors we... [more]
2986. LAPSE:2023.36151
Optimal Scheduling for Hybrid Battery Swapping System of Electric Vehicles
July 4, 2023 (v1)
Subject: Planning & Scheduling
Keywords: electric vehicle, mobile battery swapping, range anxiety, Sigmoid function.
Range anxiety seriously restricts the development of electric vehicles (EVs). To address the above issue, a hybrid battery swapping system (HBSS) is developed in this paper. In the system, EVs can swap their battery at battery swapping stations or by the roadside via battery swapping vans. The proposed scheduling strategy aims to achieve the best service quality for the HBSS by controlling the mobile swapping service fee. In the model, the uncertainty of EV selection is managed by leveraging the Sigmoid function. Based on proving the uniqueness of the solution, the particle swarm optimization algorithm is used to solve the problem. Simulations validate the effectiveness of the proposed strategy in alleviating range anxiety. Moreover, the impacts of maximum service capacity and the operating rule have been analyzed.
2987. LAPSE:2023.36150
Radial Basis Function Based Meta-Heuristic Algorithms for Parameter Extraction of Photovoltaic Cell
July 4, 2023 (v1)
Subject: System Identification
Keywords: artificial neural network, meta-heuristic algorithm, parameter identification/extraction, PV cell, PV cell model, RBF.
Accurate parameter estimation of photovoltaic (PV) cells is crucial for establishing a reliable cell model. Based on this, a series of studies on PV cells can be conducted more effectively to improve power output; an accurate model is also crucial for the operation and control of PV systems. However, due to the high nonlinearity of the cell and insufficient measured current and voltage data, traditional PV parameter identification methods are difficult to solve this problem. This article proposes a parameter identification method for PV cell models based on the radial basis function (RBF). Firstly, RBF is used to de-noise and predict the data to solve the current problems in the parameter identification field of noise data and insufficient data. Then, eight prominent meta-heuristic algorithms (MhAs) are used to identify the single-diode model (SDM), double-diode model (DDM), and three-diode model (TDM) parameters of PV cells. By comparing the identification accuracy of the three models... [more]
2988. LAPSE:2023.36149
Application of Copper Oxide Nanofluid and Phase Change Material on the Performance of Hybrid Photovoltaic−Thermal (PVT) System
July 4, 2023 (v1)
Subject: Materials
Keywords: electrical efficiency, Exergy Efficiency, nanofluid, phase change material, stability, thermal conductivity.
The objective of the study is to investigate the thermal, electrical, and exergetic performance of a hybrid photovoltaic−thermal (PVT) system under the influence of copper oxide (CuO) nanofluid and phase change material (Vaseline (petroleum jelly)) as a heat storage medium. A mathematical model was developed with the help of various energy-balance equations over the layers of the hybrid system. The performance evaluation of the PVT system was performed using pure water, CuO-water nanofluid (0.2 and 0.4% weight fractions), and CuO-water nanofluid 0.4% weight fraction with Vaseline as a phase change material. The results of the overall analysis show that the performance of the PVT system is better using CuO-water nanofluid (0.4% wt. fraction) with PCM as compared to the water-cooled PVT system and CuO-water nanofluid. The results obtained from the study show indicate that the cell temperature of PVT was reduced by 4.45% using nanofluid cooling with PCM compared to a water-cooled PVT syst... [more]
2989. LAPSE:2023.36148
Optimization of the Performances of Palm Oil Mill Effluent (POME)-Based Biogas Plants Using Comparative Analysis and Response Surface Methodology
July 4, 2023 (v1)
Subject: Numerical Methods and Statistics
Keywords: biogas, organic loading rate (OLR), palm oil mill effluent, response surface methodology (RSM).
The rapid increase in demand for renewable energy has led to a need for more efficient and effective ways to produce biogas from palm oil mill effluent (POME), which is rich in biological and chemical oxygen demand (BOD and COD). Despite its potential as a source of biogas, POME is not always effectively utilized in biogas production due to a lack of optimization of the treatment process. This study aims to address this issue by identifying the critical parameters affecting biogas production from POME and optimizing the process for maximum biogas yield and COD removal. This study employed comparative analysis and response surface methodology to optimize the performance of palm oil mill effluent (POME)-based biogas plants in Malaysia. Historical data from three commercial POME-based biogas plants in Malaysia were analyzed to identify the most critical parameters for biogas yield and COD removal. Response surface methodology, using Box−Behnken design and Design-Expert software, was then... [more]
2990. LAPSE:2023.36147
Phenolic Content, Antioxidant Capacity, and Browning Impact of Apple Slices during Microwave Drying: A Chemometric Approach
July 4, 2023 (v1)
Subject: Food & Agricultural Processes
Keywords: antioxidant capacity, browning, chemometrics, drying, Malus domestica, microwave, phenolic compounds.
Apples represent a category of products frequently consumed by people, owing both to their beneficial effects on human health and to their antioxidant effects. Microwave (MW) treatment is a simple and fast method that can be used successfully in the food industry to obtain dry apple slices, rich in bioactive compounds and with a pleasant aspect. This study presents the effect of applying microwave treating to apple slices from two cultivars (Golden Delicious and Idared), for three, four, and five minutes, respectively, at a power of 450 W, in order to reduce the browning effect. For this purpose, the browning index (BI), chromatic parameters (CIE L*a*b*), total phenolic content (Folin-Ciocâlteu method), and antioxidant capacity (by Ferric Reducing Antioxidant Power (FRAP assay) were evaluated in the case of apple slices before and after MW treatment. Based on the results obtained, it can be argued that the microwave treatment results in a significant increase in the total phenolic cont... [more]
2991. LAPSE:2023.36146
Mechanism and Application of Prestressed Yielding Support for Large-Span Roadway in Multistress Concentration Areas
July 4, 2023 (v1)
Subject: Materials
Keywords: large-span, multistress concentration areas, open-off cut roadway, prestressed yielding support.
Close-distance multilayer coal mining is common. Under the condition of extremely close-distance coal seams, it is extremely difficult to control the surrounding rock of large-span open-off cut roadways in multistress concentration areas. Based on the engineering background of the 23616 open-off cut roadway in Chaili Coal Mine, this paper investigated the influence of upper close seam mining on the stress and deformation of the lower large-span roadway in detail. The control effect of a high-strength prestressed yielding bolt and cable was analyzed systematically. The support system stress was coordinated by the yielding member to avoid excessive stress on the local support structure and reduce the stress concentration of the surrounding rock. Before and after the upper coal mining, the stress changed mainly on the left and right sides, and the displacement changed mainly on the right side and roof. The maximum deformation of the roof and the right side and the left side at two enginee... [more]
2992. LAPSE:2023.36145
Electrochemical Reduction of Pd-Nd2O3-CeO2 Mixtures in the LiCl-Li2O Melt
July 4, 2023 (v1)
Subject: Energy Systems
Keywords: intermetallic compounds, metallization, rare earth metal oxide, reduction, spent nuclear fuel.
The electrochemical reduction of pelleted heterophase powder Pd-Nd2O3-CeO2 mixtures was studied in molten LiCl-Li2O (1−1.5 wt%) at 650 °C. The influence of the composition of the mixture, as well as electrochemical factors—i.e., the amount of electricity passed and the cathode potential during electrolysis—were considered. It was found that in the presence of metallic palladium, neodymium and cerium oxides are reduced by lithium released at the cathode and form intermetallic compounds of different compositions. At potentials more positive than the formation of a phase based on liquid lithium at 0.5−0.8 V, CePd3 and NdPd3 intermetallic compounds are present in the reduced product. At potentials close to the formation of liquid lithium, a whole spectrum of intermetallic compounds is synthesized: CePd, NdPd, Ce3Pd4, and Nd3Pd4. The mechanisms of formation of palladium alloys with neodymium and cerium are proposed and considered. The degree of the reduction of lanthanide oxides was calcula... [more]
2993. LAPSE:2023.36144
Study on the Hydraulic Characteristics of an Eccentric Tapering Outlet Pressure Box Culvert in a Pumping Station
July 4, 2023 (v1)
Subject: Modelling and Simulations
Keywords: average angle of the axial velocity, eccentric tapering outlet pressure box culvert, model test, numerical simulation, optimization scheme.
The outlet pressure box culvert is often used as the drainage building of a pumping station. Because of its compact structure, it produces transverse flow velocity and then forms poor flow patterns, such as bias flow, reflux, and flow separation, which affect the discharge efficiency of the pumping station. Based on the combination of a physical model test and numerical simulation, the hydraulic characteristics of an eccentric tapering outlet pressure box culvert were analyzed. Focusing on the poor flow pattern in the box culvert, different optimization schemes were proposed to adjust the flow pattern. The flow pattern, transverse velocity distribution ratio (which represents the proportion of transverse velocity in velocity), average angle of the axial velocity, axial velocity uniformity, and pressure distribution of each scheme were compared to obtain the best scheme. The results show that the combination scheme of “diversion pier position and angle with deflecting flow baseplate” ha... [more]
2994. LAPSE:2023.36143
Development of Geopolymer Mortars Using Air-Cooled Blast Furnace Slag and Biomass Bottom Ashes as Fine Aggregates
July 4, 2023 (v1)
Subject: Materials
Keywords: acid attack resistance, air-cooled blast furnace slag, geopolymer mortar, leaching, mechanical properties, olive pomace bottom ash, porosity.
The aim of this study is to compare the mechanical and physical properties of different geopolymer mortars made with granulated blast furnace slag as a geopolymer source material, NaOH (8 M) as the activating solution, and three different types of fine aggregates (air-cooled blast furnace slag, biomass bottom ashes, and silica sand). The samples were made with an aggregate/geopolymer ratio of 3/1, and physical (density and mercury intrusion porosimetry), mechanical (compressive and flexural strength), and acid attack resistance were determined. When air-cooled blast furnace slag is used, the mechanical and acid attack properties are improved compared with silica sand and biomass bottom ashes because of the existence of amorphous phases in this slag, which increase the geopolymer reaction rate despite the particle size being higher than other aggregates. It can be highlighted that the use of ACBFS as a fine aggregate in geopolymer mortars produces better properties than in cement Portla... [more]
2995. LAPSE:2023.36142
Drying Kinetics and Quality Analysis of Coriander Leaves Dried in an Indirect, Stand-Alone Solar Dryer
July 4, 2023 (v1)
Subject: Food & Agricultural Processes
Keywords: color retention, coriander leaves, drying kinetics, indirect solar drying, moisture diffusivity, physicochemical properties.
In this study, coriander leaves were subjected to three different drying techniques; direct sun, shade, and using an indirect solar dryer. In the developed dryer, hot air obtained from a black-body solar collector was pushed by a blower powered by a solar panel, and sent to the drying chamber with multiple trays for thin-layer drying. Experiments were conducted for summer and winter seasons, and temperature and relative humidity variations in the drying chamber were measured using a data acquisition system. Indirect solar dryer performance was evaluated and compared with sun drying and shade drying for drying kinetics, moisture diffusivity, and product quality. The drying rate curves show a linear falling rate throughout the drying process. The drying kinetic models are well-fitted with the Midilli and Kucuk thin-layer drying model. The effective moisture diffusivity of the dried coriander shows a decreasing trend, sun drying (2.63 × 10−10 m2/s and 1.05 × 10−10 m2/s) followed by solar... [more]
2996. LAPSE:2023.36141
Efficient Approaches for Layout Problems of Large Chemical Plants Based on MILP Model
July 4, 2023 (v1)
Subject: Energy Systems
Keywords: engineering experience, iterative framework, MILP, plant layout, solution efficiency.
This paper presents two novel solution approaches for addressing large-scale multi-floor process plant layout problems. Based on the mixed integer linear programming (MILP) model, the first solution approach employs a multi-directional search strategy while the second improves solution efficiency by reducing model size through an iterative framework. Both approaches determine the spatial arrangement of the plant equipment considering equipment-floor allocation, non-overlapping constraints, tall equipment penetrating multiple floors, etc. The computational results indicate that the proposed approaches achieved potential cost savings for four illustrative examples when compared to the previous studies. Finally, engineering experience constraints were included to represent a more complex industrial situation, and their applicability was tested with the last example.
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