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Records Added in March 2023
Records added in March 2023
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1476. LAPSE:2023.24720
Application of the HPLC Method in Parenteral Nutrition Assessment: Stability Studies of Ondansetron
March 28, 2023 (v1)
Subject: Biosystems
Keywords: drug determination, HPLC, ondansetron, parenteral nutrition, stability study
Ondansetron (OND) is a serotonin type 3 receptor antagonist that exhibits antiemetic activity. From the clinical point of view, vomiting and nausea prevention is an important task. Anticancer treatment and recovery impact the patient’s overall state by affecting appetite, well-being, and physical activity, and consequently, nutrition quality. Depending on the patient’s indication and condition, parenteral nutrition is administered to meet full nutritional requirements. In addition, antiemetic drugs can be added to the parenteral nutrition (PN) admixture to treat chemo- or radio-therapy-induced nausea and vomiting. However, adding any medication to the PN admixture can result in the instability of the composition in the overall admixture. This study aimed to develop the HPLC method of determination of OND in Lipoflex special, one of the most popular, ready-to-use PN admixtures. The proposed HPLC method and the sample preparation procedure were suitable for analyzing OND in PN admixture... [more]
1477. LAPSE:2023.24719
Microstructure Evolution and Hot Deformation Behavior of a CuNiSn Alloy
March 28, 2023 (v1)
Subject: Materials
Keywords: CuNiSn alloy, hot deformation behavior, microstructure evolution
The hot deformation behavior of Cu-20.0Ni-5.0Sn-0.25Zn-0.22Mn was investigated using a Gleeble-3500 thermal simulator with a temperature range from 720 °C to 880 °C and a strain rate range from 0.001 s−1 to 1 s−1. The results show that the flow stress increased with the increase of the strain rate and the decrease of the temperature. The constitutive equation of the alloy was established based on the peak flow stress. Figures of the power dissipation efficiency and flow instability with the variable of the true strain from 0.2 to 0.8 displayed the dynamic change of power dissipation efficiency and the instability area. The domain of 730−770 °C and 0.001−0.01 s−1 possessed a power dissipation efficiency over 40% throughout the whole deformation. The flow instability always appeared at a high strain rate from 0.1 s−1 to 1 s−1 during the whole deformation process. The nucleation site of the dynamic recrystallization generally appeared along the grain boundaries, indicating the discontinuo... [more]
1478. LAPSE:2023.24718
The Development of a Liquid Chromatography High-Resolution Mass Spectrometric Method for Apixaban Quantification in Dried Plasma Spots in Parallel Reaction Monitoring Mode
March 28, 2023 (v1)
Subject: Materials
Keywords: apixaban, DPS, dried blood spot, dried plasma spot, high-resolution mass spectrometry, LC–HRMS, parallel reaction monitoring
This work aimed at developing and validating a rapid, sensitive, and robust method of liquid chromatography with high-resolution mass spectrometry (LC−HRMS) in parallel reaction monitoring (PRM) mode for apixaban quantification in dried plasma spots (DPSs) with a simple extraction procedure. A 25 µL sample of human plasma was placed onto Whatman 903 Protein Saver Cards and allowed to dry; 3.2 mm diameter disks were cut out from DPSs using a puncher, and 100 µL of a working internal standard solution was added to each sample. After this, they were vortexed on a shaker for 15 min at 800 rpm and 40 °C and quick centrifugation (10,000× g, 10 s), and then the extracts were transferred into a 300 µL vial for LC−HRMS. Data were acquired in PRM mode via detection of all target product ions with 10 ppm tolerance. Total analysis time was 5 min. The LC−HRMS method was validated for the 10−400 ng/mL range with R2 > 0.99. Within this range, intra- and interday variability of precision and accuracy... [more]
1479. LAPSE:2023.24717
Continuous Ultrasound-Assisted Esterification and Transesterification of Palm Fatty Acid Distillate for Ethyl Ester Production
March 28, 2023 (v1)
Subject: Energy Systems
Keywords: ethyl ester, palm fatty acid distillate, palm fatty acid distillate, ultrasound clamp
Ethyl ester production from palm fatty acid distillate (PFAD) with ethanol in the presence of sulfuric acid and potassium hydroxide was performed in a continuous three-step process using the ultrasound clamps and an ultrasonic probe. The ultimate goal was to produce biodiesel from the PFAD. In the first and second esterification steps, 16 units of a 400 W ultrasound clamp (20 kHz) were attached 100-m apart along each tubular reactor. In the third transesterification step, a 1000-W ultrasonic homogenizer (18 kHz) was used in a 100-mL continuous reactor. A composite central design of experiments and the response surface methodology (RSM) were used to develop predictive models and identify the optimal conditions of each step based on the purities of ethyl ester. The optimal conditions in the first step were 46.1 vol.% ethanol, 1.4 vol.% sulfuric acid, and purity 66.68 wt.% ethyl ester. In the second step, the optimized conditions were 57 vol.% ethanol, and 2.1 vol.% sulfuric acid, purity... [more]
1480. LAPSE:2023.24716
Digital Twins for Tissue Culture Techniques—Concepts, Expectations, and State of the Art
March 28, 2023 (v1)
Subject: Modelling and Simulations
Keywords: 3D culture, digital twin, mathematical model, organ-on-a-chip, tissue engineering
Techniques to provide in vitro tissue culture have undergone significant changes during the last decades, and current applications involve interactions of cells and organoids, three-dimensional cell co-cultures, and organ/body-on-chip tools. Efficient computer-aided and mathematical model-based methods are required for efficient and knowledge-driven characterization, optimization, and routine manufacturing of tissue culture systems. As an alternative to purely experimental-driven research, the usage of comprehensive mathematical models as a virtual in silico representation of the tissue culture, namely a digital twin, can be advantageous. Digital twins include the mechanistic of the biological system in the form of diverse mathematical models, which describe the interaction between tissue culture techniques and cell growth, metabolism, and the quality of the tissue. In this review, current concepts, expectations, and the state of the art of digital twins for tissue culture concepts wil... [more]
1481. LAPSE:2023.24715
Fractionation of Tilapia By-Product Protein Hydrolysate Using Multilayer Configuration of Ultrafiltration Membrane
March 28, 2023 (v1)
Subject: Biosystems
Keywords: dead-end ultrafiltration, multilayer membrane, peptide transmission, permeate flux, tilapia by-product protein hydrolysate
Production of small-sized peptides is significant because of their health benefits. Ultrafiltration (UF) membrane provides an effective fractionation of small-sized peptides on a large scale. Thus, the present study was aimed to evaluate the performance of multilayer UF membrane in fractionating tilapia fish by-product (TB) protein hydrolysate by observing the permeate flux, peptide transmission, and peptide distribution under different stirring speed, pH of feed solution, and salt concentration (NaCl). The fractionation process was carried out using a dead-end UF membrane system that consists of a stack of two membrane sheets with different (10/5 kDa) and similar (5/5 kDa) pore sizes in one device. The highest permeate flux (10/5 kDa−39.5 to 47.3 L/m2.h; 5/5 kDa− 15.8 to 20.3 L/m2.h) and peptide transmission (10/5 kDa−51.8 to 61.0%; 5/5 kDa−18.3 to 23.3%) for both multilayer membrane configurations were obtained at 3.0 bar, 600 rpm, pH 8, and without the addition of salt. It was also... [more]
1482. LAPSE:2023.24714
Research on Local Heating Regeneration Method for Air-Conditioning Systems
March 28, 2023 (v1)
Subject: Environment
Keywords: Absorption, air-conditioning, heat localization, performance, solar steam
Absorption air-conditioning systems have a great advantage in terms of energy conservation and environmental protection. However, the large amount of energy waste in the thermal regeneration process leads to lower efficiency and impedes its development. To reduce energy loss and improve performance, a local heating regeneration method is proposed in this paper. The main principle is reducing the volume of the liquid participating regeneration. Including the solar steam mode, two modes are introduced and configured. Theoretical and experimental research has been made on the new methods. Models have been developed for comparison analysis. Experiments have been conducted on water and absorbent solution with different modes. Performance has been evaluated based on the experimental data. The results expose the influence of different parameters, like liquid volume and solution concentration, on the regeneration process. The local heating method improved the regeneration efficiency by 40% in... [more]
1483. LAPSE:2023.24713
Chitosan-Coating Effect on the Characteristics of Liposomes: A Focus on Bioactive Compounds and Essential Oils: A Review
March 28, 2023 (v1)
Subject: Energy Systems
Keywords: chitosan, coating, essential oils, liposomes, mechanism, polyelectrolyte
In recent years, liposomes have gained increasing attention for their potential applications as drug delivery systems in the pharmaceutic, cosmetic and food industries. However, they have a tendency to aggregate and are sensitive to degradation caused by several factors, which may limit their effectiveness. A promising approach to improve liposomal stability is to modify liposomal surfaces by forming polymeric layers. Among natural polymers, chitosan has received great interest due to its biocompatibility and biodegradability. This review discussed the characteristics of this combined system, called chitosomes, in comparison to those of conventional liposomes. The coating of liposomes with chitosan or its derivatives improved liposome stability, provided sustained drug release and increased drug penetration across mucus layers. The mechanisms behind these results are highlighted in this paper. Alternative assembly of polyelectrolytes using alginate, sodium hyaluronate, or pectin with c... [more]
1484. LAPSE:2023.24712
A Hybrid Genetic Programming−Gray Wolf Optimizer Approach for Process Optimization of Biodiesel Production
March 28, 2023 (v1)
Subject: Energy Systems
Keywords: biodiesel, evolutionary algorithms, genetic programming, gray wolf optimizer, metamodel, Optimization, parameter optimization, regression
Biodiesel is one the most sought after alternate fuels in the current global need for sustainable and renewable energy sources due to their lower emissions and no major modification requirement to existing engines. However, the performance and productivity of the biodiesel production process are significantly dependent on the process parameters. In this regard, a novel hybrid genetic programming-gray wolf optimizer approach for the process optimization of biodiesel production is proposed in this paper. For an illustration of the proposed approach, kinematic viscosity is expressed as a symbolic regression metamodel to account for the influence of catalyst concentration, reaction temperature, alcohol-to-oil molar ratio, and reaction time. Then, the genetic programming-based symbolic regression metamodel is used as an objective function by the gray wolf optimizer to optimize the process parameters. The obtained results show that the proposed approach is simple, accurate, and robust.
1485. LAPSE:2023.24711
Sustainable Development in EU Countries in the Framework of the Europe 2020 Strategy
March 28, 2023 (v1)
Subject: Environment
Keywords: Europe 2020, resource efficiency, sustainable development, sustainable growth
The Europe 2020 Strategy was proposed with a long-term vision to ensure prosperity, development, and competitiveness for the member countries. This strategy is divided into three main areas named “growth”. One of these is sustainable growth. This is an area of sustainability, where the partial targets are referred to as the “20-20-20 approach”, and includes a reduction of greenhouse gas emissions, an increase in energy efficiency, and the sharing of renewable energy sources. However, questions arise, including: How do member states meet these targets? Which countries are leaders in this area? According to these stated questions, the aim of this article is to assess how EU countries are meeting the set targets for sustainable growth resulting from the Europe 2020 strategy and to identify the countries with the best results in this area. We looked for answers to these questions in the analysis of sustainable indicators, which were transformed into a synthetic measure for comparability of... [more]
1486. LAPSE:2023.24710
Dynamic and Statistical Operability of an Experimental Batch Process
March 28, 2023 (v1)
Subject: Modelling and Simulations
Keywords: automated experimentation, batch reactor, digital twin, dynamic design space, dynamic operability, statistics
The operability approach has been traditionally applied to measure the ability of a continuous process to achieve desired specifications, given physical or design restrictions and considering expected disturbances at steady state. This paper introduces a novel dynamic operability analysis for batch processes based on classical operability concepts. In this analysis, all sets and statistical region delimitations are quantified using mathematical operations involving polytopes at every time step. A statistical operability analysis centered on multivariate correlations is employed for the first time to evaluate desired output sets during transition that serve as references to be followed to achieve the final process specifications. A dynamic design space for a batch process is, thus, generated through this analysis process and can be used in practice to guide process operation. A probabilistic expected disturbance set is also introduced, whereby the disturbances are described by pseudoran... [more]
1487. LAPSE:2023.24709
Combustion Enhancement of Pulverized Coal with Targeted Oxygen-Enrichment in an Ironmaking Blast Furnace
March 28, 2023 (v1)
Subject: Energy Systems
Keywords: coal burnout, coal particles temperature, ironmaking blast furnace, targeted oxygen-enrichment
In this study, a targeted oxygen-enrichment technology was proposed to enhance coal combustion in an ironmaking blast furnace. The coal flow and combustion characteristics under targeted oxygen-enrichment were investigated using the computational fluid dynamics (CFD) method. The results showed that oxygen utilization and coal burnout were significantly increased under targeted oxygen-enrichment. The coal burnout at 24% O2 concentration was 86.29%, which was the maximum and indicated an increase of 13.13%. However, the cooling effect of room-temperature oxygen had some adverse effects on coal combustion. Given this, the effect of coal particle temperature on coal combustion was investigated based on targeted oxygen-enrichment. The coal combustion process was further enhanced. The coal burnout at a 600 K particle temperature and 25% oxygen concentration was 91.12% and had an increase of 17.96%, which was the maximum.
1488. LAPSE:2023.24708
Noises Cutting and Natural Neighbors Spectral Clustering Based on Coupling P System
March 28, 2023 (v1)
Subject: System Identification
Keywords: natural neighbors, noises, P system, spectral clustering
Clustering analysis, a key step for many data mining problems, can be applied to various fields. However, no matter what kind of clustering method, noise points have always been an important factor affecting the clustering effect. In addition, in spectral clustering, the construction of affinity matrix affects the formation of new samples, which in turn affects the final clustering results. Therefore, this study proposes a noise cutting and natural neighbors spectral clustering method based on coupling P system (NCNNSC-CP) to solve the above problems. The whole algorithm process is carried out in the coupled P system. We propose a natural neighbors searching method without parameters, which can quickly determine the natural neighbors and natural characteristic value of data points. Then, based on it, the critical density and reverse density are obtained, and noise identification and cutting are performed. The affinity matrix constructed using core natural neighbors greatly improve the... [more]
1489. LAPSE:2023.24707
Transient Thermal Performance of Power Cable Ascertained Using Finite Element Analysis
March 28, 2023 (v1)
Subject: Environment
Keywords: ampacity, COMSOL, finite element method, transient thermal performance of cable
This paper presents the computation of the cable ampacity and the temperature distribution through long duration based on the equivalent thermal circuit based on IEC 60287 standard and the Finite element method using COMSOL (Multiphysics environment, version 5.5). This study investigated the cable ampacity and the temperature rise of the cable core and sheath at steady state and emergency conditions. The cable ampacity was investigated at different conditions such as the variation of cable depth, soil properties, and soil temperature. The results confirmed the adaptation between the thermal circuit results and the COMSOL results as well as the effectiveness of using the numerical method to compute the cable ampacity. Using the COMSOL-based thermal properties evaluations, the transient performance of the cable is ascertained. The transient study is performed for different cable loading currents and dry zone sizes.
1490. LAPSE:2023.24706
Pervaporation of Aqueous Ethanol Solutions through Rigid Composite Polyvinyl-Alcohol/Bacterial Cellulose Membranes
March 28, 2023 (v1)
Subject: Food & Agricultural Processes
Keywords: FTIR analysis, membrane selectivity, permeate flow rate, pervaporation, PVA-bacterial cellulose membrane
The paper focuses on synthesis, characterization and testing in ethanol-water separation by pervaporation of new membrane types based on polyvinyl alcohol (PVA) and bacterial cellulose (BC). A technology for obtaining these membranes deposited on a ceramic support is presented in the experimental section. Three PVA-BC composite membranes with different BC content were obtained and characterized by FTIR, SEM and optic microscopy. The effects of operating temperature (40−60 °C), permeate pressure (18.7−37.3 kPa) and feed ethanol concentration (24−72%wt) on total permeate flow rate (0.09−0.23 kg/m2/h) and water/ethanol selectivity (5−23) were studied based on an appropriate experimental plan for each PVA-BC membrane. Statistical models linking the process factors to pervaporation performances were obtained by processing the experimental data. Ethanol concentration of the processed mixture had the highest influence on permeate flow rate, an increase in ethanol concentration leading to a de... [more]
1491. LAPSE:2023.24705
Techno-Economic Analysis of a Process for the Aqueous Conversion of Corn Stover into Lactic and Levulinic Acid through Sn-Beta Catalysis
March 28, 2023 (v1)
Subject: Materials
Keywords: lactic acid, levulinic acid, renewable chemicals, renewable fuels, Technoeconomic Analysis
A readily available source for renewable fuels and chemicals is corn stover, which consists of the leftover stalks, leaves, husks, and cobs from the corn plant and makes up nearly half of the yield of a corn crop. Common practice is to pretreat it with sulfuric acid to break down the hemicellulose, releasing xylose, followed by enzymatic hydrolysis to convert the cellulose into glucose. Using a Sn-Beta catalyst, it is possible to convert these monomeric sugars into lactic, levulinic, formic, and acetic acids. This paper presents the results of a techno-economic analysis (TEA) of the commercial feasibility of producing these acids from corn stover. Two preliminary process designs were evaluated which represent two separate reaction yields: a balanced yield of both lactic and levulinic acids and the yields from a co-catalysis with CaSO4 to produce primarily lactic acid. Both process designs are scaled to process 230,000 MT/year of corn stover. An AACS Class 4 factored broad capital cost... [more]
1492. LAPSE:2023.24704
Effect of Air-Frying on the Bioactive Properties of Eggplant (Solanum melongena L.)
March 28, 2023 (v1)
Subject: Biosystems
Keywords: air-fry, cooking method, eggplant, phenolic compounds
The eggplant is an important vegetable that is used all over the world and it contains valuable bioactive properties. Cooking methods affect the nutritional value as well as the functional characteristics of vegetables. This study investigated the effect of air-frying at different temperatures and the extraction solvents on the bioactive properties of eggplant. The eggplant air-fried for 25 min and extracted with 50% ethanol exhibited the highest total flavonoid content (35.10 mg catechin equivalent per gram dry weight), while its total polyphenol content was found as 87.81 mg gallic acid equivalent per gram dry weight. The uncooked sample exhibited the lowest DPPH scavenging (IC50: 422.12 mg/mL reducing power: 0.914), while the highest DPPH scavenging activity (IC50: 2.87 mg/mL; reducing power: 0.936) was recorded for the sample air-fried for 25 min and extracted with 50% ethanol. The highest amount of tannic acid was found in medium-cooked eggplant, while chlorogenic acid was the hig... [more]
1493. LAPSE:2023.24703
Co-Treatment with Cefotaxime and High-Fructose Diet Inducing Nonalcoholic Fatty Liver Disease and Gut Microbial Dysbiosis in Mice
March 28, 2023 (v1)
Subject: Biosystems
Keywords: cefotaxime, gut microbial, high-fructose diet, nonalcoholic fatty liver disease
High fructose diet causes metabolic syndrome and induces host gut microbial dysbiosis and related obesity and nonalcoholic fatty liver disease (NAFLD). Several antibiotic treatments could prevent fatty liver. However, there are studies that have demonstrated that a high-fructose diet could influence the gut microbial dysbiosis and induce fatty liver. The purpose of this study was performed to partially modify the gut bacterial composition with a single cefotaxime treatment, which might affect the fructose-induced NAFLD severity. The C57BL/6JNarl male mice were divided into four groups including vehicle/chow diet (VE-CD), vehicle/high-fructose diet (VE-FD), antibiotic (cefotaxime (CF))/CD, and CF/FD. The results showed that body weight gain, moderate hepatic steatosis severity, epididymal white adipose tissue hypertrophy, and insulin resistance occurrence with NAFLD-related symptoms were observed only in the CF-FD group. The raised protein expression of hepatic lipogenesis was observed... [more]
1494. LAPSE:2023.24702
Hydroxy-tyrosol as a Free Radical Scavenging Molecule in Polymeric Hydrogels Subjected to Gamma-Ray Irradiation
March 28, 2023 (v1)
Subject: Materials
Keywords: citrate buffer hydrogel, hydrogel, hydroxy-tyrosol, irradiation-induced cross-linking, phosphate buffer hydrogel, polyethylene oxide-based hydrogel
Biomedical engineering is employing hydrogels with increasingly exciting possibilities for the treatment and regeneration of pathologically altered, degenerated, or traumatized tissues. Still, the sterilization processes may undesirably change the chemical and physical properties of hydrogels through cross-linking reactions. This work aims to characterize a new method of producing polyethylene oxide (PEO) hydrogels exploiting hydroxy-tyrosol (HT), an anti-oxidant molecule derived from olive leaf and olive oil, as a free radical scavenger to either prevent or limit gamma-ray-induced cross-linking. For this purpose, we produced hydrogels with PEO with two different buffer solutions (phosphate and citrate), varying HT concentration. We analyzed hydrogel preparations before and after gamma-ray irradiation, assessing the viscosity through rheological analysis and the chemical changes through IR analysis. We performed high-performance liquid chromatography (HPLC) analysis to measure residual... [more]
1495. LAPSE:2023.24701
Mechanism of the Absent Air Column in Three Products Hydrocyclone Screen (TPHS): Experiment and Simulation
March 28, 2023 (v1)
Subject: Modelling and Simulations
Keywords: air column, Computational Fluid Dynamics, high definition camera experiment, reynolds stress model, three products hydrocyclone screen
Three products hyrdrocyclone screen (TPHS) has been proposed for particle separation based on size. In TPHS, a cylindrical screen was embedded in a conventional hydrocyclone (CH) to combine the centrifugal classification and screening to particle separation based on size. The industrial application of TPHS indicates its better device performance than CH. Although, the earlier studies reveal some common understanding for TPHS, the information of the absent air column remains unknown. Hence, the combination of physical experiment and numerical simulation was considered involving a 75 mm TPHS for this knowledge gap. First, both the computational fluid dynamics (CFD) simulation with Reynolds stress mode and the physical experiment with a high-definition camera illustrate the development process details of a flow field in TPHS. That is, the water was imported along the tangential inlet into TPHS; then under the effects of the feed chamber wall and gravity, the liquid phase spiraled downward... [more]
1496. LAPSE:2023.24700
Preparation and Characterization of Two Different Liposomal Formulations with Bioactive Natural Extract for Multiple Applications
March 28, 2023 (v1)
Subject: Materials
Keywords: encapsulation efficiency, film hydration method, liposomes, phospholipids, Stellaria media (L.) Vill., Zeta potential
Liposomes continue to attract great interest due to their increased bioavailability in the body and because the substances encapsulated are protected while maintaining their effectiveness. The aim of this study is to obtain “giant” liposomes by lipid film hydration using a preparation formula with two different phospholipids, phosphatidylcholine (PC) and phosphatidylserine (PS). Firstly, the macro- and microscopic characterization, total phenols content and antioxidant capacity of the plant Stellaria media (L.) Vill. were assessed. Then, Stellaria media (L.) Vill. extract was encapsulated in both formulations (PCE and PSE) and the liposomes were characterized according to their morphology, size distribution and Zeta potential using optical microscopy and dynamic light scattering. The encapsulation efficiency (EE%) was determined using the Folin−Ciocalteu method and the values of both formulations were compared. PC and PCE liposomes with a diameter between 712 and 1000 nm and PS and PSE... [more]
1497. LAPSE:2023.24699
Improvement of a Specific Culture Medium Based on Industrial Glucose for Carotenoid Production by Xanthophyllomyces dendrorhous
March 28, 2023 (v1)
Subject: Biosystems
Keywords: carotenoids, chemical defined medium, glutamate, industrial glucose, vitamins, X. dendrorhous
In this study, a low-cost chemically defined (CD) culture medium was proposed and evaluated with the aim of replacing culture media such as yeast mold (YM) and yeast peptone dextrose (YPD), commonly used for growth and carotenoid production by Xanthophyllomyces dendrorhous. Initially, the CD culture medium was compared to the YM and YPD. The growth in optical density (OD) and carotenoid production (mg/L) of the cultures reached 4.88, 6.76, 5.79, and 0.67, 0.92, and 0.69, respectively. The CD culture served as the basis of an improved specific culture medium containing industrial glucose. Additionally, in this new formulation, vitamins, glutamate, and other compounds were evaluated. Industrial glucose more than doubled carotenoid production; however, the addition of vitamins was not essential for X. dendrorhous cultivation. Moreover, glutamate and Na2HPO4 proved to be highly significant factors (p-value < 0.05), increasing carotenoid biosynthesis from 0.67 to 1.33 mg/L. The specific... [more]
1498. LAPSE:2023.24698
A Study on Lap Joint Welding of Thin Plate ASTM F1684 Using Fiber Laser Welding
March 28, 2023 (v1)
Subject: Materials
Keywords: ASTM F1684, fiber laser welding, lap joint welding, tensile strength
The International Maritime Organization (IMO) has developed stricter regulations on emission standards for sulfur oxides, etc., and the demand for Liquefied Natural Gas (LNG) is increasing as an alternative to satisfy these standards. This study relates to fiber laser welding, an approach which offers high-speed welding and low welding deformation for ASTM F1684, which has a low coefficient of thermal expansion (CTE) even in a cryogenic environment. In this study, through three preliminary experiments using 0.25 mm thick Invar, the conditions required to secure sufficient penetration depth and back bead were identified. Through the cross-sectional observation analysis, the welding conditions without defects were identified and the trend of penetration shape according to increasing welding speed was identified. Following a lap joint laser welding experiment under the secured conditions, the mechanical properties were evaluated through the shear strength test and the heat influence range... [more]
1499. LAPSE:2023.24697
Determination of Transformers’ Insulating Paper State Based on Classification Techniques
March 28, 2023 (v1)
Subject: Process Operations
Keywords: classification techniques, degradation, degree of polymerization, furfuraldehyde, insulating paper, power transformer
The continuity of transformer operation is very necessary for utilities to maintain a continuity of power flow in networks and achieve a desired revenue. Most failures in a transformer are due to the degradation of the insulating system, which consists of insulating oil and paper. The degree of polymerization (DP) is a key detector of insulating paper state. Most research in the literature has computed the DP as a function of furan compounds, especially 2-furfuraldehyde (2-FAL). In this research, a prediction model was constructed based on some of most periodical tests that were conducted on transformer insulating oil, which were used as predictors of the insulating paper state. The tests evaluated carbon monoxide (CO), carbon dioxide (CO2), breakdown voltage (VBD), interfacial tension (IF), acidity (ACY), moisture (M), oil color (OC), and 2-furfuraldehyde (2-FAL). The DP, which was used as the key indicator for the paper state, was categorized into five classes labeled 1, 2, 3, 4, and... [more]
1500. LAPSE:2023.24696
Flavonoids Induce Migration Arrest and Apoptosis in Detroit 562 Oropharynx Squamous Cell Carcinoma Cells
March 28, 2023 (v1)
Subject: Biosystems
Keywords: apoptosis, cell migration, cell viability, flavonoids, head and neck cancer, squamous cell carcinoma
Despite advances in the treatment of head and neck squamous cell carcinoma (HNSCC), the morbidity remains at a high level due to the resistance of SCC cells to chemotherapeutics. This study aimed to determine and compare the magnitude of the flavonoids’ effectiveness in activating apoptosis and migration arrest in HNSCC cells in vitro. Methods: Head and neck SCC cells of the Detroit 562 line were exposed to a range of concentrations (5−100 μM) of quercetin (Que), hesperidin (Hes) and rutin (Rut) for 24 and 48 h. The SCC cell viability and migration rate were investigated using cytotoxicity and migration inhibition assays. Muse Cell Analyzer flow cytometry was utilized to quantitatively assess the apoptosis rate of Detroit 562 cells exposed to Que, Hes and Rut. The morphology of the SCC cells was evaluated via hematoxylin-eosin staining. Results: The viability diminishment of the Detroit 562-line cells treated with Que, Hes and Rut for 48 h revealed a significant dose-dependent trend, r... [more]
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