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Records Added in March 2023
Records added in March 2023
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1226. LAPSE:2023.24970
Computational Fluid Dynamic Analysis of the Pharyngeal Airway after Bimaxillary Orthognathic Surgery in Patients with Mandibular Prognathism
March 28, 2023 (v1)
Subject: Modelling and Simulations
Keywords: adjusted pressure coefficient, Computational Fluid Dynamics, orthognathic surgery, pharyngeal airway, pressure drop, upper airway volume
This study aimed to analyze pharyngeal airflow characteristics and their relationship with the skeletal movement of the maxilla and mandible after bimaxillary orthognathic surgery in patients with skeletal class III (mandibular prognathism) malocclusion. Cone-beam computed tomography (CBCT) was conducted before surgery (T0), immediately after surgery (T1), and at least six months after surgery (T2). Digital imaging and communications in medicine files were transferred to InVivo (Anatomage) software to measure the skeletal changes after surgery. The changes in the maxillary and mandibular position, tongue position, and hyoid bone position were analyzed. Patient-specific models were reconstructed using 3D-Doctor software. The models after converting to the stereolithography (STL) file for Ansys integrated computer engineering and manufacturing code for computational fluid dynamics (ICEM CFD), commercial software were used for calculating the geometry, pressure drop and adjusted pressure... [more]
1227. LAPSE:2023.24969
Multiscale Modeling and Recurrent Neural Network Based Optimization of a Plasma Etch Process
March 28, 2023 (v1)
Subject: Numerical Methods and Statistics
Keywords: multiscale model, Optimization, plasma etch, recurrent neural network
In this article, we focus on the development of a multiscale modeling and recurrent neural network (RNN) based optimization framework of a plasma etch process on a three-dimensional substrate with uniform thickness using the inductive coupled plasma (ICP). Specifically, the gas flow and chemical reactions of plasma are simulated by a macroscopic fluid model. In addition, the etch process on the substrate is simulated by a kinetic Monte Carlo (kMC) model. While long time horizon optimization cannot be completed due to the computational complexity of the simulation models, RNN models are applied to approximate the fluid model and kMC model. The training data of RNN models are generated by open-loop simulations of the fluid model and the kMC model. Additionally, the stochastic characteristic of the kMC model is presented by a probability function. The well-trained RNN models and the probability function are then implemented in computing an open-loop optimization problem, in which a moving... [more]
1228. LAPSE:2023.24968
Phosphate and Ammonium Removal from Water through Electrochemical and Chemical Precipitation of Struvite
March 28, 2023 (v1)
Subject: Environment
Keywords: ammonium, chemical precipitation, electrocoagulation, phosphate, struvite, Wastewater
Batch electrocoagulation (BEC), continuous electrocoagulation (CEC), and chemical precipitation (CP) were compared in struvite (MgNH4PO4·6H2O) precipitation from synthetic and authentic water. In synthetic water treatment (SWT), struvite yield was in BEC 1.72, CEC 0.61, and CP 1.54 kg/m3. Corresponding values in authentic water treatment (AWT) were 2.55, 3.04, and 2.47 kg/m3. In SWT, 1 kg struvite costs in BEC, CEC, and CP were 0.55, 0.55, and 0.11 €, respectively, for AWT 0.35, 0.22 and 0.07 €. Phosphate removal in SWT was 93.6, 74.5, and 71.6% in BEC, CEC, and CP, respectively, the corresponding rates in AWT were 89.7, 77.8, and 74.4%. Ammonium removal for SWT in BEC, CEC, and CP were 79.4, 51.5, and 62.5%, respectively, rates in AWT 56.1, 64.1, and 60.9%. Efficiency in CEC and BEC are equal in nutrient recovery in SWT, although energy efficiency was better in CEC. CP is cheaper than BEC and CEC.
1229. LAPSE:2023.24967
Surface Functionalization of Biochar from Oil Palm Empty Fruit Bunch through Hydrothermal Process
March 28, 2023 (v1)
Subject: Environment
Keywords: biochar, Biomass, hydrothermal functionalization, oil palm, wastewater treatment
The use of biochar as an adsorbent for wastewater treatment purposes has been hindered due to its lower surface area compared to activated carbon. Current research on increasing surface functional groups on biochar surfaces to improve its adsorption performance suggests using high chemical concentration and long period of modification. This study solves these problems by focusing on improving surface functionalities of biochar via the hydrothermal functionalization process. Oil palm empty fruit bunch biochar was functionalized using autoclave with nitric acid as the functionalization agent. Functionalized biochar properties such as Brunauer−Emmett−Teller (BET) surface area and surface functional groups were analyzed and compared with untreated biochar. Fourier Transform Infrared (FTIR) spectroscopic analysis shows a significant increase in absorption by oxygen functional groups and is corroborated with energy dispersive X-ray (EDX) analysis. The process does not result in any major cha... [more]
1230. LAPSE:2023.24966
Process Design and Sustainable Development—A European Perspective
March 28, 2023 (v1)
Subject: Process Design
Keywords: chemical industry, design tools, megatrends, process design, process industry, sustainable development
This paper describes the state of the art and future opportunities for process design and sustainable development. In the Introduction, the main global megatrends and the European Union’s response to two of them, the European Green Deal, are presented. The organization of professionals in the field, their conferences, and their publications support the two topics. A brief analysis of the published documents in the two most popular databases shows that the environmental dimension predominates, followed by the economic one, while the social pillar of sustainable development is undervalued. The main design tools for sustainability are described. As an important practical case, the European chemical and process industries are analyzed, and their achievements in sustainable development are highlighted; in particular, their strategies are presented in more detail. The conclusions cover the most urgent future development areas of (i) process industries and carbon capture with utilization or s... [more]
1231. LAPSE:2023.24965
The Mathematical Modeling and Simulation of a New Mitigation System Including a Remote Impoundment
March 28, 2023 (v1)
Subject: Modelling and Simulations
Keywords: consequence analysis, mitigation system modelling, remote impoundment
After the occurrence of a hydrogen fluoride leakage accident that triggered massive losses in Gumi, South Korea in 2012, the government and companies have been interested in installing mitigation systems to minimize the loss of a leakage accident. What lacks in previous researches studying mitigation systems is an evaluation of how much a mitigation system can reduce the impact of accidents. Therefore, modeling-based simulations of mitigation systems should be urgently developed to analysis of the performance of a mitigation system. This study aims to design a mitigation system to reduce the amount of materials leaked to the outside when a leakage accident of a storage tank occurs and determine its design specifications through the use of modeling. The basic concept is that when leakage occurs, leakage material in a dike is drained to a remote impoundment installed under the ground, while the material in the storage vessel is transferred to a reserve tank by a pump at the same time. To... [more]
1232. LAPSE:2023.24964
Waste Wood Fly Ash Treatment in Switzerland: Effects of Co-Processing with Fly Ash from Municipal Solid Waste on Cr(VI) Reduction and Heavy Metal Recovery
March 28, 2023 (v1)
Subject: Materials
Keywords: acid leaching, chromate reduction, heavy metal recovery, hot alkaline extraction, MSWI fly ash, wood ash treatment
In Switzerland, waste wood fly ash (WWFA) must be treated before deposition on landfills due to its high pollutant load (Cr(VI) and heavy metals). Acid fly ash leaching, the process used for heavy metal recovery from municipal solid waste incineration fly ash (MSWIFA), represents a possible treatment for heavy metal depletion and Cr(VI) reduction in WWFA. The co-processing of WWFA with MSWIFA during acid fly ash leaching was investigated in laboratory- and industrial-scale experiments with different setups. Of interest were the effects on heavy metal recovery efficiency, the successful outcome of Cr(VI) reduction and consumption of neutralizing chemicals (HCl, H2O2). Detailed chemical and mineralogical characterization of two WWFA types and MSWIFA showed that MSWIFA has higher concentrations in potentially harmful elements than WWFA. However, both WWFA types showed high concentrations in Pb and Cr(VI), and therefore need treatment prior to deposition. Depending on the waste wood propor... [more]
1233. LAPSE:2023.24963
In Vitro Anti-Wrinkle and Skin-Moisturizing Effects of Evening Primrose (Oenothera biennis) Sprout and Identification of Its Active Components
March 28, 2023 (v1)
Subject: System Identification
Keywords: antioxidant, Oenothera biennis, physiologically active ingredient, skin-improvement activity, tandem mass spectrometry
The present study aimed to investigate the effect of Oenothera biennis sprout extract (OBS-E) on skin-function improvement in an in vitro system and to identify its pharmaceutically active components. OBS-E showed antioxidant ability in radical scavenging and reducing power assays, significantly inhibited matrix metalloproteinases-1 and -2, and increased the production of type I collagen, indicating its anti-wrinkle activity. Furthermore, OBS-E significantly increased the level of hyaluronic acid (HA) and the expression of moisturizing genes, such as hyaluronic acid synthase 2 (HAS2) and aquaporin 3 (AQP3), indicating it is effective in enhancing skin hydration. High-performance liquid chromatography (HPLC) and mass spectrometry (MS) analyses showed that OBS-E contained high levels of polyphenolic acids, such as gallic acid and ellagic acid, in addition to flavonoid glycosides, such as luteolin 7-glucuronide and quercetin 3-glucuronide. Our results suggest that these major phytochemica... [more]
1234. LAPSE:2023.24962
Topical Biocompatible Fluconazole-Loaded Microemulsions Based on Essential Oils and Sucrose Esters: Formulation Design Based on Pseudo-Ternary Phase Diagrams and Physicochemical Characterization
March 28, 2023 (v1)
Subject: Materials
Keywords: biocompatible sucrose ester, essential oil, fluconazole, microemulsion, pseudo-ternary phase diagram
To initiate our research into the development of biocompatiîle gelled-microemulsions based on essential oils (EOs) and sucrose esters (SEs) for the topical delivery of fluconazole, this formulation study investigated the usefulness of two relatively harmless natural non-ionic surfactants from the group of SEs (sucrose laurate and stearate) to form, in the presence of antifungal EOs, stable, isotropic microemulsions effective on fluconazole solubilization. Fluconazole’s solubility in EO significantly depended on their chemical composition, showing higher values for cinnamon, oregano and clove essential oils, further selected as oil phase components for microemulsion formulations. The phase behavior of several EO−isopropyl miristate/SE−isopropanol/water systems was assessed through pseudo-ternary phase diagrams constructed by microplate dilution technique. The hydrocarbon chain length of the SE and EO type strongly influenced the size of the microemulsion region in the pseudo-ternary pha... [more]
1235. LAPSE:2023.24961
An Expedient Catalytic Process to Obtain Solketal from Biobased Glycerol
March 28, 2023 (v1)
Subject: Energy Systems
Keywords: acetalization, biodiesel, glycerol, silica sulfuric acid, solketal
Developing simple and effective chemistry able to convert industrial waste streams into valuable chemicals is a primary contributor to sustainable development. Working in the context of biodiesel production, we found that plain bisulfate on silica (SSANa, 3.0 mmol/g) proved to be an optimal catalyst to convert glycerol into solketal. With the assistance of a proper anhydrification technique, isolated yields of 96% were achieved working in mild conditions, on 100 g scale.
1236. LAPSE:2023.24960
Investigation of Coalescence-Induced Droplet Jumping on Mixed-Wettability Superhydrophobic Surfaces
March 28, 2023 (v1)
Subject: Modelling and Simulations
Keywords: jumping velocity, mixed-wettability, molecular dynamics simulations, superhydrophobic surfaces
Coalescence-induced droplet jumping has received more attention recently, because of its potential applications in condensation heat transfer enhancement, anti-icing and self-cleaning, etc. In this paper, the molecular dynamics simulation method is applied to study the coalescence-induced jumping of two nanodroplets with equal size on the surfaces of periodic strip-like wettability patterns. The results show that the strip width, contact angle and relative position of the center of two droplets are all related to the jumping velocity, and the jumping velocity on the mixed-wettability superhydrophobic surfaces can exceed the one on the perfect surface with a 180° contact angle on appropriately designed surfaces. Moreover, the larger both the strip width and the difference of wettability are, the higher the jumping velocity is, and when the width of the hydrophilic strip is fixed, the jumping velocity becomes larger with the increase of the width of the hydrophobic strip, which is contra... [more]
1237. LAPSE:2023.24959
Iterative Method for Tuning Multiloop PID Controllers Based on Single Loop Robustness Specifications in the Frequency Domain
March 28, 2023 (v1)
Subject: Process Control
Keywords: frequency domain specifications, multivariable control, PID control, process control
Multiloop proportional-integral-derivative (PID) controllers are widely used for controlling multivariable processes due to their understandability, simplicity and other practical advantages. The main difficulty of the methodologies using this approach is the fact that the controllers of different loops interact each other. Thus, the knowledge of the controllers in the other loops is necessary for the evaluation of one loop. This work proposes an iterative design methodology of multiloop PID controllers for stable multivariable systems. The controllers in each step are tuned using single-input single-output (SISO) methods for the corresponding effective open loop process (EOP), which considers the interaction of the other loops closed with the controllers of the previous step. The methodology uses a frequency response matrix representation of the system to avoid process approximations in the case of elements with time delays or complicated EOPs. Consequently, different robustness margi... [more]
1238. LAPSE:2023.24958
Model Parameterization with Quantitative Proteomics: Case Study with Trehalose Metabolism in Saccharomyces cerevisiae
March 28, 2023 (v1)
Subject: Energy Systems
Keywords: Genetic Algorithm, heat stress, kinetic model, metabolic engineering, metabolic modelling, trehalose metabolism
When Saccharomyces cerevisiae undergoes heat stress it stimulates several changes that are necessary for its survival, notably in carbon metabolism. Notable changes include increase in trehalose production and glycolytic flux. The increase in glycolytic flux has been postulated to be due to the regulatory effects in upper glycolysis, but this has not been confirmed. Additionally, trehalose is a useful industrial compound for its protective properties. A model of trehalose metabolism in S. cerevisiae was constructed using Convenient Modeller, a software that uses a combination of convenience kinetics and a genetic algorithm. The model was parameterized with quantitative omics under standard conditions and validated using data collected under heat stress conditions. The completed model was used to show that feedforward activation of pyruvate kinase by fructose 1,6-bisphosphate during heat stress contributes to the increase in metabolic flux. We were also able to demonstrate in silico tha... [more]
1239. LAPSE:2023.24957
Noncatalytic Biodiesel Synthesis under Supercritical Conditions
March 28, 2023 (v1)
Subject: Energy Systems
Keywords: biodiesel, noncatalytic supercritical process, transesterification
The constant increase in greenhouse gases in the environment is forcing people to look for different ways to reduce such pollution. One of these ways is the use of biodiesel for road transport. Conventional biodiesel production involves the catalytic triglyceride transesterification process. When using homogeneous two-stage catalysis, it is difficult to purify the resulting product from the by-products formed, and the catalysts cannot be reused. In the case of heterogeneous catalysis, the process costs are increased due to separation and regeneration of the catalysts. To solve these problems of catalytic synthesis, a noncatalytic process has been recently studied that which takes place under supercritical conditions for an alcohol or other acyl receptor. In such biodiesel production, fatty feedstocks and alcohols are used as raw materials, with the synthesis taking place at supercritical conditions for alcohol, i.e., high temperature and pressure, thus making the process quite simple.... [more]
1240. LAPSE:2023.24956
A Critical Review on the Synthesis of Natural Sodium Alginate Based Composite Materials: An Innovative Biological Polymer for Biomedical Delivery Applications
March 28, 2023 (v1)
Subject: Materials
Keywords: biomedical application, biomedical delivery, gene delivery, natural polymer, sodium alginate
Sodium alginate (Na-Alg) is water-soluble, neutral, and linear polysaccharide. It is the derivative of alginic acid which comprises 1,4-β-d-mannuronic (M) and α-l-guluronic (G) acids and has the chemical formula (NaC6H7O6). It shows water-soluble, non-toxic, biocompatible, biodegradable, and non-immunogenic properties. It had been used for various biomedical applications, among which the most promising are drug delivery, gene delivery, wound dressing, and wound healing. For different biomedical applications, it is used in different forms with the help of new techniques. That is the reason it had been blended with different polymers. In this review article, we present a comprehensive overview of the combinations of sodium alginate with natural and synthetic polymers and their biomedical applications involving delivery systems. All the scientific/technical issues have been addressed, and we have highlighted the recent advancements.
1241. LAPSE:2023.24955
Polymeric Films Containing Tenoxicam as Prospective Transdermal Drug Delivery Systems: Design and Characterization
March 28, 2023 (v1)
Subject: Materials
Keywords: DSC, FT-IR, kinetic analysis, polymeric film, tenoxicam
The administration of drugs via transdermal therapeutic systems has become an attractive form of therapeutic approach, considering its advantages and the high patient compliance achieved, making them a viable alternative, especially in the treatment of chronic diseases. The purpose of our study was the development of polymer-based films containing tenoxicam (TX) and the analysis of dissolution kinetics. Auxiliary substances represent an important part of pharmaceutical forms, so during the first stage, TX and excipient compatibility were verified. Fourier Transform Infrared Spectroscopy (FT-IR) and Differential Scanning Calorimetry (DSC) analyses were performed on TX and on physical mixtures of TX-HPMCE5 and TX-HPMC15kcP. Three polymeric films of TX (TX1, TX2, and TX3) were prepared using a solvent evaporation technique. Release studies were done at 32 °C ± 1 °C with a Franz diffusion cell. The results of the DSC and FT-IR analyses demonstrated the compatibility of the active substance... [more]
1242. LAPSE:2023.24954
High Yield Super-Hydrophobic Carbon Nanomaterials Using Cobalt/Iron Co-Catalyst Impregnated on Powder Activated Carbon
March 28, 2023 (v1)
Subject: Materials
Keywords: bimetallic catalyst, carbon nanotubes, chemical vapor deposition, powder activated carbon, super-hydrophobic
Synthesis of super-hydrophobic carbonaceous materials is gaining a broader interest by the research community due to its versatile application in separation processes, special coating technologies, and membrane distillation. Carbon nanomaterials (CNMs) may exhibit stable super-hydrophobic character due to their unique physio-chemical features which can be further controlled based on customer requirements by optimizing the process variables. This study deals with the application of a bimetallic catalyst composed of iron (Fe) and cobalt (Co) to synthesize CNMs from powder activated carbon as a precursor. The process parameters were optimized to ensure super-hydrophobic surfaces. Chemical vapor deposition was utilized for the growth of carbon nanomaterials. The impact of input variables on the desired output of yield and contact angle was analyzed. The chemical vapor deposition process was optimized using the response surface methodology based on Box-Behnken design. The proportion of the... [more]
1243. LAPSE:2023.24953
Biodegradation Kinetic Studies of Phenol and p-Cresol in a Batch and Continuous Stirred-Tank Bioreactor with Pseudomonas putida ATCC 17484 Cells
March 28, 2023 (v1)
Subject: Biosystems
Keywords: batch reactor, biodegradation, continuous stirred-tank bioreactor, immobilized cells, p-cresol, phenol
The biodegradation of phenol, p-cresol, and phenol plus p-cresol mixtures was evaluated using Pseudomonas putida ATCC 17484 in aerobic batch reactors. Shake-flask experiments were performed separately using growth medium with initial nominal concentrations of phenol (50−600 mg L−1) and p-cresol (50−600 mg L−1) as well as phenol (50−600 mg L−1) plus p-cresol (50−600 mg L−1). The complete degradation of phenol and p-cresol was achieved within 48 h and 48−56 h, respectively, for all initial concentrations of phenol and p-cresol. The maximum cell growth rate using phenol (μmax,P = 0.45 h−1) was much faster than that using p-cresol (μmax,C = 0.185−1 h). The larger Ki value for phenol (310.5 mg L−1) revealed that the P. putida cells had a higher resistance to phenol inhibition compared with p-cresol (243.56 mg L−1). A mixture of phenol and p-cresol in batch experiments resulted in the complete removal of phenol within 52−56 h for initial phenol concentrations of 50−500 mg L−1. The time neede... [more]
1244. LAPSE:2023.24952
Effect of Selected Drying Methods and Emerging Drying Intensification Technologies on the Quality of Dried Fruit: A Review
March 28, 2023 (v1)
Subject: Environment
Keywords: drying, emerging technologies, fruits, pretreatments, processing, quality
Drying is one of the oldest methods for food preservation that removes the water from fruit and makes it available for consumption throughout the year. Dried fruits can be produced by small- and large-scale processors, which makes them a very popular food among consumers and food manufacturers. The most frequent uses of drying technology include osmotic dehydration, vacuum drying, freeze-drying and different combinations of other drying technologies. However, drying may provoke undesirable changes with respect to physiochemical, sensory, nutritional and microbiological quality. Drying process energy efficiency and the quality of dried fruits are crucial factors in fruit drying. Recently, innovative technologies such as ultrasound, pulsed electric field and high pressure may be used as a pretreatment or in combination with traditional drying technologies for process intensification. This could result in quality improvements of dried fruits and enhanced efficiency and capacity of the pro... [more]
1245. LAPSE:2023.24951
Effect of Grape Seed Flour on the Antioxidant Profile, Textural and Sensory Properties of Waffles
March 28, 2023 (v1)
Subject: Food & Agricultural Processes
Keywords: antioxidant activity, polyphenols, sensory evaluation, waffles
The study aimed to enrich waffle products with grape seed flour, but without affecting their sensory properties. The grape seed flour was obtained from grape pomace, and as an ingredient rich in bioactive compounds such as fiber, polyphenols and minerals, it was used to fortify waffles in concentrations of 1, 3, 5 and 10%. The results for the total polyphenolic content, ferric ion reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picryl-hydrazyl (DPPH) inhibition, showed the highest effect with 10% grape seed flour fortification, including 1.25 mg of gallic acid equivalent/g, 5.62 µmol Trolox/g and 26.65% DPPH inhibition, respectively. Texture analysis revealed an increase in hardness of the waffles along with the increase of grape seed flour percentage, while there was no evident change in moisture in any of the tested samples. Sensory evaluation showed no significant differences regarding overall impression or the estimated price value for all samples, even though evident changes... [more]
1246. LAPSE:2023.24950
Analyzing the Renewable Energy and CO2 Emission Levels Nexus at an EU Level: A Panel Data Regression Approach
March 28, 2023 (v1)
Subject: Energy Systems
Keywords: bioenergy, Biofuels, CO2 emissions, panel data, Renewable and Sustainable Energy
In the past decades, carbon dioxide (CO2) emissions have become an important issue for many researchers and policy makers. The focus of scientists and experts in the area is mainly on lowering the CO2 emission levels. In this article, panel data is analyzed with an econometric model, to estimate the impact of renewable energy, biofuels, bioenergy efficiency, population, and urbanization level on CO2 emissions in European Union (EU) countries. Our results underline the fact that urbanization level has a negative impact on increasing CO2 emissions, while biofuels, bioenergy production, and renewable energy consumption have positive and direct impacts on reducing CO2 emissions. Moreover, population growth and urbanization level are negatively correlated with CO2 emission levels. The authors’ findings suggest that the public policies at the national level must encourage the consumption of renewable energy and biofuels in the EU, while population and urbanization level should come along wit... [more]
1247. LAPSE:2023.24949
Numerical Analyses of Heterogeneous CLC Reaction and Transport Processes in Large Oxygen Carrier Particles
March 28, 2023 (v1)
Subject: Modelling and Simulations
Keywords: chemical looping combustion, Computational Fluid Dynamics, heterogeneous, intraparticle diffusion, oxygen carrier, packed bed
Heterogeneous chemical looping combustion (CLC) reactions and conjugate transports in large oxygen carrier particles were numerically investigated with computational fluid dynamics (CFD) approaches, in which a simplified noncatalytic reaction model was implemented for reducing intraparticle modelling computation. Volumic gas-solid reactions were treated as surface reactions based on the equivalent internal surface in the particle model. In large porous particles such as fixed bed CLC reactors, the heterogeneous reactions are often limited by intraparticle diffusion. Comprehensive analyses were conducted on transports across the particle surface and their influences on reactions inside the single particles. A threshold Reynolds number of external convections was found for the enhancement of intraparticle reactions. The heterogeneous reactions, intraparticle diffusions and interstitial transports in a fixed bed CLC reactor randomly packed with 597 spheres were thoroughly analysed with th... [more]
1248. LAPSE:2023.24948
Analysis of Bubble Flow Mechanism and Characteristics in Gas−Liquid Cyclone Separator
March 28, 2023 (v1)
Subject: Modelling and Simulations
Keywords: bubble flow, experimental research, gas–liquid cyclone, numerical simulation
The separation of bubbles in a gas−liquid cyclone is complicated. A combination of numerical simulation and visual experimentation was considered apt to reveal the microscopic mechanisms of bubble flow. First of all, cyclones with different structures were numerically simulated. The calculation results show that the larger the diameter of the exhaust port, the better the bubble flow effect. When the exhaust port diameter was 24 mm, the gas discharge efficiency was 8% higher than that with an exhaust port diameter of 16 mm. The sequence of the bubble flow effect of a four-structure cyclone was obtained, and the gas discharge efficiency of the cyclone with a rectangular inlet was 7% higher than that of the trapezoidal inlet. Finally, a visual experimental platform was built to compare the rectangular inlet cyclone and spiral inlet cyclone with the best bubble flow effect. In accordance with the simulation numerical calculations, the bubble flow effect of the rectangular inlet cyclone was... [more]
1249. LAPSE:2023.24947
Controlling Nanoparticle Formulation: A Low-Budget Prototype for the Automation of a Microfluidic Platform
March 28, 2023 (v1)
Subject: Process Control
Keywords: lipoplex, microfluidics, nanoparticle, polyplex, python, raspberry pi, siRNA
Active pharmaceutical ingredients (API) with suboptimal pharmacokinetic properties may require formulation into nanoparticles. In addition to the quality of the excipients, production parameters are crucial for producing nanoparticles which reliably deliver APIs to their target. Microfluidic platforms promise increased control over the formulation process due to the decreased degrees of freedom at the micro- and nanoscale. Publications about these platforms usually provide only limited information about the soft- and hardware required to integrate the microfluidic chip seamlessly into an experimental set-up. We describe a modular, low-budget prototype for microfluidic mixing in detail. The prototype consists of four modules. The control module is a raspberry pi executing customizable python scripts to control the syringe pumps and the fraction collector. The feeding module consists of up to three commercially available, programable syringe pumps. The formulation module can be any macro... [more]
1250. LAPSE:2023.24946
In-Situ Heavy Oil Aquathermolysis in the Presence of Nanodispersed Catalysts Based on Transition Metals
March 28, 2023 (v1)
Subject: Energy Systems
Keywords: aquathermolysis, catalyst, heavy oil, in-situ upgrading, transition metals
The aquathermolysis process is widely considered to be one of the most promising approaches of in-situ upgrading of heavy oil. It is well known that introduction of metal ions speeds up the aquathermolysis reactions. There are several types of catalysts such as dispersed (heterogeneous), water-soluble and oil soluble catalysts, among which oil-soluble catalysts are attracting considerable interest in terms of efficiency and industrial scale implementation. However, the rock minerals of reservoir rocks behave like catalysts; their influence is small in contrast to the introduced metal ions. It is believed that catalytic aquathermolysis process initiates with the destruction of C-S bonds, which are very heat-sensitive and behave like a trigger for the following reactions such as ring opening, hydrogenation, reforming, water−gas shift and desulfurization reactions. Hence, the asphaltenes are hydrocracked and the viscosity of heavy oil is reduced significantly. Application of different hyd... [more]
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