Browse
Records Added in July 2021
Records added in July 2021
Change month: January | February | March | April | May | June | July | August | September | October | November | December
51. LAPSE:2021.0645
Sorption of Organic Pollutants onto Soils: Surface Diffusion Mechanism of Congo Red Azo Dye
July 28, 2021 (v1)
Subject: Food & Agricultural Processes
Keywords: Congo red, diffusion, rate limiting step, soil, sorption mechanism
For the protection of human and ecological receptors from the effects of soil pollution with chemical compounds, we need to know the behavior and transport of pollutants in soil. This work investigated the Congo red (CR) acid dye sorption on three natural soils collected from central and northeastern regions of Romania, symbolized as IS-65, IS-T, and MH-13. To define the mechanism of sorption and identify the rate governing step, various diffusion models such as Weber−Morris intraparticle diffusion, Boyd, film and pores diffusion, and mass transfer analysis have been verified. The intraparticle diffusion analysis of Congo red sorption onto soils has been described by a multi-linear plots, showing that the sorption process takes place by surface sorption and intraparticle diffusion in macro, meso, and micropores. The values of intraparticle diffusion coefficient kid increased with any rise of the initial concentration of pollutant. The results show that the values of pore diffusion coef... [more]
52. LAPSE:2021.0644
Chemoenzymatic Synthesis of New Aromatic Esters of Mono- and Oligosaccharides
July 28, 2021 (v1)
Subject: Reaction Engineering
Keywords: aromatic oligosaccharides, lipases, sugar ester
An efficient and convenient chemoenzymatic route for the synthesis of novel phenolic mono-, di- and oligosaccharide esters is described. Acetal derivatives of glucose, sucrose, lactose and inulin were obtained by chemical synthesis. The fully characterized pure sugar acetals were subjected to enzymatic esterification with 3-(4-hydroxyphenyl) propionic acid (HPPA) in the presence of Novozyme 435 lipase as a biocatalyst. The aromatic esters of alkyl glycosides and glucose acetal were obtained with good esterification yields, characterized by mass spectrometry (MALDI-TOF MS), infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (1H NMR, 13C NMR). The synthesis of aromatic esters of disaccharide acetals was successful only for the enzymatic esterification of sucrose acetal. The new chemoenzymatic route allowed the synthesis of novel aromatic esters of inulin as the inulin monoacetal monoester and diester and the inulin diacetal monoester with a polymerization degree of... [more]
53. LAPSE:2021.0643
A Comparative Study of Ethanol Concentration in Costal Cartilage in Relation to Blood and Urine
July 28, 2021 (v1)
Subject: Biosystems
Keywords: alternative material, costal cartilage, Ethanol, gas chromatography with flame ionization detector (GC-FID), post mortem analysis
Blood is not always available in forensic autopsies, therefore, the search for alternative sampling materials is needed. This study aimed at examining if ethanol can be detected in costal cartilage and to investigate if different forms of costal cartilage can give accurate information about ethanol concentration in the blood or urine of human cadavers (n = 50). Ethanol concentration in samples of unground costal cartilage (UCC), ground costal cartilage (GCC), femoral venous blood, and urine was analyzed using a gas chromatography-flame ionization detector (GC-FID). Due to Polish law, we used two different cut-off points: the blood alcohol concentration >0.2 mg/mL defined as the ‘after use’ condition, and the blood alcohol concentration >0.5 mg/mL defined as the ‘state of insobriety’. Based on the constructed receiver operating characteristics (ROC) curves, the optimal cut-off point for ethanol content as the ‘after use’ condition was 0.273 mg/g for the UCC method and 0.069 mg/g for the... [more]
54. LAPSE:2021.0642
Graphene Oxide as a Nanocarrier for Biochemical Molecules: Current Understanding and Trends
July 28, 2021 (v1)
Subject: Biosystems
Keywords: cancer drug, drug delivery, gene delivery, graphene, graphene oxide, nanocarrier, nanomaterials
The development of an advanced and efficient drug delivery system with significant improvement in its efficacy and enhanced therapeutic value is one of the critical challenges in modern medicinal biology. The integration of nanomaterial science with molecular and cellular biology has helped in the advancement and development of novel drug delivery nanocarrier systems with precision and decreased side effects. The design and synthesis of nanocarriers using graphene oxide (GO) have been rapidly growing over the past few years. Due to its remarkable physicochemical properties, GO has been extensively used in efforts to construct nanocarriers with high specificity, selectivity, and biocompatibility, and low cytotoxicity. The focus of this review is to summarize and address recent uses of GO-based nanocarriers and the improvements as efficient drug delivery systems. We briefly describe the concepts and challenges associated with nanocarrier systems followed by providing critical examples of... [more]
55. LAPSE:2021.0641
Hybrid Modification of Unsaturated Polyester Resins to Obtain Hydro- and Icephobic Properties
July 26, 2021 (v1)
Subject: Materials
Keywords: hydrophobicity, ice adhesion, icephobicity, multi-functionalized silicone compounds (MFSC), nanosilica, unsaturated polyester resin
Ice accumulation is a key and unsolved problem for many composite structures with polymer matrices, e.g., wind turbines and airplanes. One of the solutions to avoid icing is to use anti-icing coatings. In recent years, the influence of hydrophobicity of a surface on its icephobic properties has been studied. This solution is based on the idea that a material with poor wettability maximally reduces the contact time between a cooled drop of water and the surface, consequently prevents the formation of ice, and decreases its adhesion to the surface. In this work, a hybrid modification of a gelcoat based on unsaturated polyester resin with nanosilica and chemical modifiers from the group of triple functionalized polyhedral oligomeric silsesquioxanes (POSS) and double organofunctionalized polysiloxanes (generally called multi-functionalized organosilicon compounds (MFSC)) was applied. The work describes how the change of modifier concentration and its structural structure finally influences... [more]
56. LAPSE:2021.0640
CFD Modeling and Experimental Validation of an Alkaline Water Electrolysis Cell for Hydrogen Production
July 26, 2021 (v1)
Subject: Modelling and Simulations
Keywords: alkaline water electrolysis, CFD analysis, Energy Storage, green hydrogen, numerical simulation, polarization curve, Renewable and Sustainable Energy, void fraction
Although alkaline water electrolysis (AWE) is the most widespread technology for hydrogen production by electrolysis, its electrochemical and fluid dynamic optimization has rarely been addressed simultaneously using Computational Fluid Dynamics (CFD) simulation. In this regard, a two-dimensional (2D) CFD model of an AWE cell has been developed using COMSOL® software and then experimentally validated. The model involves transport equations for both liquid and gas phases as well as equations for the electric current conservation. This multiphysics approach allows the model to simultaneously analyze the fluid dynamic and electrochemical phenomena involved in an electrolysis cell. The electrical response was evaluated in terms of polarization curve (voltage vs. current density) at different operating conditions: temperature, electrolyte conductivity, and electrode-diaphragm distance. For all cases, the model fits very well with the experimental data with an error of less than 1% for the po... [more]
57. LAPSE:2021.0639
Recombinant Technologies to Improve Ruminant Production Systems: The Past, Present and Future
July 26, 2021 (v1)
Subject: Food & Agricultural Processes
Keywords: hormone, recombinant proteins, ruminants, vaccine
The use of recombinant technologies has been proposed as an alternative to improve livestock production systems for more than 25 years. However, its effects on animal health and performance have not been described. Thus, understanding the use of recombinant technology could help to improve public acceptance. The objective of this review is to describe the effects of recombinant technologies and proteins on the performance, health status, and rumen fermentation of meat and milk ruminants. The heterologous expression and purification of proteins mainly include eukaryotic and prokaryotic systems like Escherichia coli and Pichia pastoris. Recombinant hormones have been commercially available since 1992, their effects remarkably improving both the reproductive and productive performance of animals. More recently the use of recombinant antigens and immune cells have proven to be effective in increasing meat and milk production in ruminant production systems. Likewise, the use of recombinant... [more]
58. LAPSE:2021.0638
Effect of Titanium Dioxide Nanocomposite Material and Antimicrobial Agents on Mushrooms Shelf-Life Preservation
July 26, 2021 (v1)
Subject: Food & Agricultural Processes
Keywords: antimicrobial agents, mushrooms, nanocomposite material, shelf-life
Mushrooms have limited shelf-life and it can be prolonged if suitable conditions and treatments are effectively applied. In this study, nanocomposite material and antimicrobial agents with a combination of chitosan were used as novel packaging material for mushroom preservation. The microbiological analysis, physicochemical properties, headspace gas analysis, and polyphenol oxidase activity (PPO) during cold storage were investigated. As compared with control, coated mushrooms with chitosan (CHS), and nano-titanium dioxide CHSTiO2 thymol + tween-80 CHSTiO2/TT80 coating treatment showed significantly (p ≤ 0.05) lower respiration rate, microbial contaminations (4.27 log CFU/g), and (5.93 log CFU/g) for total yeast/mold and aerobic plate counts, respectively. The weight loss ratio was the lowest for CHSTiO2/TT80 (10.88% loss) followed by CHSTiO2 (11.76% loss). CHSTiO2/TT80 recorded a higher electrolyte leakage rate (25.84%) and acidity. While the lowest PPO activity was established for CH... [more]
59. LAPSE:2021.0637
Establishment of the Predicting Models of the Dyeing Effect in Supercritical Carbon Dioxide Based on the Generalized Regression Neural Network and Back Propagation Neural Network
July 26, 2021 (v1)
Subject: Intelligent Systems
Keywords: back propagation neural network, generalized regression neural network, prediction model, supercritical carbon dioxide, the dyeing effect
With the growing demand of supercritical carbon dioxide (SC-CO2) dyeing, it is important to precisely predict the dyeing effect of supercritical carbon dioxide. In this work, Generalized Regression Neural Network (GRNN) and Back Propagation Neural Network (BPNN) models have been employed to predict the dyeing effect of SC-CO2. These two models have been constructed based on published experimental data and calculated values. A total of 386 experimental data sets were used in the present work. In GRNN and BPNN models, two input parameters, such as temperature, pressure, dye stuff types, carrier types and dyeing time, were selected for the input layer and one variable, K/S value or dye-uptake, was used in the output layer. It was found that the values of mean-relative-error (MRE) for BPNN model and for GRNN model are 3.27−6.54% and 1.68−3.32%, respectively. The results demonstrate that both BPNN and GPNN models can accurately predict the effect of supercritical dyeing but the former is be... [more]
60. LAPSE:2021.0636
In Situ Deposition of Green Silver Nanoparticles on Urinary Catheters under Photo-Irradiation for Antibacterial Properties
July 26, 2021 (v1)
Subject: Materials
Keywords: antimicrobial urinary catheter, catheter-associated urinary tract infection, durian rind, green synthesis, silver nanoparticle
Urinary tract infections, especially catheter-associated urinary tract infections (CAUTIs), are the most common type of nosocomial infections. Patients with chronic indwelling urinary catheters have a higher risk of infection due to biofilm formation on the urinary catheter surface. Therefore, in this work, a novel, cost-effective antimicrobial urinary catheter was developed using green technology. Silver nanoparticles (AgNPs) synthesized from Mon Thong durian rind waste were used as an antimicrobial agent for the prevention of infection. Flavonoids, phenolic compounds, and glucose extracted from durian rind were used as a reducing agent to reduce the Ag+ dissolved in AgNO3 solution to form non-aggregated AgNPs under light irradiation. The AgNPs were simultaneously synthesized and coated on the inner and outer surfaces of silicone indwelling urinary catheters using the dip coating method. The results showed that the antimicrobial urinary catheter fabricated using a 0.3 mM AgNO3 concent... [more]
61. LAPSE:2021.0635
Effect of Temperature and Concentration of Zeolite Catalysts from Geothermal Solid Waste in Biodiesel Production from Used Cooking Oil by Esterification−Transesterification Process
July 26, 2021 (v1)
Subject: Reaction Engineering
Keywords: analcime zeolite catalyst, biodiesel, geothermal solid waste, used cooking oil, yield of biodiesel
The production of biodiesel using zeolite catalysts from geothermal solid waste has been studied. This study aims to make zeolite catalysts as catalysts in biodiesel production, assessing the effect of catalyst concentration, and temperature in the esterification−transesterification process on the biodiesel yield produced. The results showed that the synthesized zeolite catalyst was an analcime zeolite catalyst (Al1.9Na1.86O12Si4). The biodiesel yield of 98.299% with 100% fatty acid alkyl ester (FAAE) content was achieved at a catalyst concentration of 5%wt and a reaction temperature of 300 °C for one-hour reaction time. The yield of biodiesel decreased with repeated catalysts, which experienced morphological changes before and after three usage times. Consequently, in this case, the catalyst cannot be regenerated.
62. LAPSE:2021.0634
Biochemical Composition and Phycoerythrin Extraction from Red Microalgae: A Comparative Study Using Green Extraction Technologies
July 26, 2021 (v1)
Subject: Process Design
Keywords: fatty acids, macronutrients, microwave, phycoerythrin, Porphyridium sp., ultrasound
Porphyridium spp. is a debated family that produces phycoerythrin (PE) for use in multiple industrial applications. We compared the differences in the biochemical composition and phycoerythrin yield of P. cruentum and P. purpureum by conventional and green extraction technologies. The protein content in P. cruentum was 42.90 ±1.84% w/w. The omega-3 fatty acid (FA) was highlighted by eicosapentaenoic acid (EPA, C20:5, ω-3, ~9.74 ± 0.27% FA) and arachidonic acid (ARA, C20:4, ω-6, ~18.02 ± 0.81% FA) represented the major omega-6 fatty acid. Conversely, P. purpureum demonstrated a higher lipid content (17.34 ± 1.35% w/w) and an FA profile more saturated in palmitic (C16:0, 29.01 ± 0.94% FA) and stearic acids (C18:0, 50.02 ± 1.72% FA). Maceration and freeze/thaw were the conventional methods, whereas microwave (MW) and ultrasound (US) served as green procedures for PE extraction under the factorial-design methodology. Aqueous solvents, extraction-time and power were the main factors in the... [more]
63. LAPSE:2021.0633
Antimicrobial Resistance of Lactobacillus johnsonii and Lactobacillus zeae in Raw Milk
July 26, 2021 (v1)
Subject: Food & Agricultural Processes
Keywords: antimicrobial resistance, Lactobacillus johnsonii, Lactobacillus zeae, MALDI-TOF-MS, milk, PCR
Lactobacillus johnsonii and Lactobacillus zeae are among the lactobacilli with probiotic properties, which occur in sour milk products, cheeses, and to a lesser extent in raw milk. Recently, resistant strains have been detected in various species of lactobacilli. The aim of the study was to determine the incidence of resistant Lactobacillus johnsonii and Lactobacillus zeae strains in various types of raw milk. A total of 245 isolates were identified by matrix-assisted laser desorption/ionization mass spectrometry and polymerase chain reaction methods as Lactobacillus sp., of which 23 isolates of Lactobacillus johnsonii and 18 isolates of Lactobacillus zeae were confirmed. Determination of susceptibility to selected antibiotics was performed using the E-test and broth dilution method, where 7.3% of lactobacilli strains were evaluated as ampicillin-resistant, 14.7% of isolates as erythromycin-resistant, and 4.9% of isolates as clindamycin-resistant. The genus Lactobacillus johnsonii had... [more]
64. LAPSE:2021.0632
Is Steam Explosion a Promising Pretreatment for Acid Hydrolysis of Lignocellulosic Biomass?
July 26, 2021 (v1)
Subject: Food & Agricultural Processes
Keywords: 2nd generation sugars, bioeconomy, biorefinery, furfural, glucose, hydrolyzate, hydroxymethylfurfural, lignocellulose, xylose
For the production of sugars and biobased platform chemicals from lignocellulosic biomass, the hydrolysis of cellulose and hemicelluloses to water-soluble sugars is a crucial step. As the complex structure of lignocellulosic biomass hinders an efficient hydrolysis via acid hydrolysis, a suitable pretreatment strategy is of special importance. The pretreatment steam explosion was intended to increase the accessibility of the cellulose fibers so that the subsequent acid hydrolysis of the cellulose to glucose would take place in a shorter time. Steam explosion pretreatment was performed with beech wood chips at varying severities with different reaction times (25−34 min) and maximum temperatures (186−223 °C). However, the subsequent acid hydrolysis step of steam-exploded residue was performed at constant settings at 180 °C with diluted sulfuric acid. The concentration profiles of the main water-soluble hydrolysis products were recorded. We showed in this study that the defibration of the... [more]
65. LAPSE:2021.0630
Numerical Simulation Analysis of Main Structural Parameters of Hydrocyclones on Oil-Gas Separation Effect
July 19, 2021 (v1)
Subject: Modelling and Simulations
Keywords: computational fluid dynamics (CFD), hydrocyclone, oil-gas separation, separation performance, structural parameters
Gas pollution in marine lubricating oil systems is harmful to the normal operation of a ship, and is one of the main reasons for the decline of the performance of lubricating oil. In this research, a classic 75 mm hydrocyclone was selected as the oil−gas separation device. A hydrocyclone is a device that uses the density difference of the two-phase flow to separate the dispersed phase in the centrifugal force field. Compared with ordinary active oil−gas separators, hydrocyclones do not require additional power devices. After establishing the physical model of the hydrocyclone, the distribution characteristics of the flow field and oil−gas two-phase flow separation performance of the hydrocyclone were studied using computational fluid dynamics (CFD) technology. The influence of vortex finder diameter, vortex finder length, spigot diameter, cylindrical-part length, and cone angle on the oil−gas separation performance of the hydrocyclone were investigated. It was found that the vortex fin... [more]
66. LAPSE:2021.0629
Stability of Optimal Closed-Loop Cleaning Scheduling and Control with Application to Heat Exchanger Networks under Fouling
July 19, 2021 (v1)
Subject: Planning & Scheduling
Keywords: closed-loop scheduling, fouling, heat exchanger networks, optimal control and scheduling, scheduling stability
Heat exchanger networks subject to fouling are an important example of dynamic systems where performance deteriorates over time. To mitigate fouling and recover performance, cleanings of the exchangers are scheduled and control actions applied. Because of inaccuracy in the models, as well as uncertainty and variability in the operations, both schedule and controls often have to be revised to improve operations or just to ensure feasibility. A closed-loop nonlinear model predictive control (NMPC) approach had been previously developed to simultaneously optimize the cleaning schedule and the flow distribution for refinery preheat trains under fouling, considering their variability. However, the closed-loop scheduling stability of the scheme has not been analyzed. For practical closed-loop (online) scheduling applications, a balance is usually desired between reactivity (ensuring a rapid response to changes in conditions) and stability (avoiding too many large or frequent schedule changes... [more]
67. LAPSE:2021.0628
Shear-Thinning Effect of the Spinning Disc Mixer on Starch Nanoparticle Precipitation
July 19, 2021 (v1)
Subject: Materials
Keywords: Process Intensification, shear rate, solvent–antisolvent precipitation, spinning disc, starch nanoparticles, thin films
Spinning disc technology is capable of achieving intensified micromixing within thin liquid films created through large shear rates, typically of the order of 103 s−1, generated by means of fast disc surface rotation. In this study the effect of the high shear on solvent−antisolvent mixing and starch nanoparticle precipitation is reported. Rheological studies of starch solutions at 2% w/v and 4% w/v have demonstrated their shear-thinning behaviour at the large shear rates experienced on the spinning disc surface. The effect of such high shear rate on starch nanoparticle precipitation is investigated alongside solute concentration and several other operating parameters such as flow rate, disc rotational speed, and solvent/antisolvent ratio. A reduction in nanoparticle size has been observed with an increase in starch concentration, although agglomeration was found to be more prevalent amongst these smaller particles particularly at larger flow rates and disc rotational speeds. Micromixi... [more]
68. LAPSE:2021.0627
Eulerian Multiphase Simulation of the Particle Dynamics in a Fluidized Bed Opposed Gas Jet Mill
July 19, 2021 (v1)
Subject: Modelling and Simulations
Keywords: comminution, compressible flow, granular temperature, OpenFOAM, particle velocity, turbulent flow
The compressible and turbulent gas−solid multiphase flow inside a fluidized bed opposed jet mill was systematically investigated through numerical simulations using the Euler−Euler approach along with the kinetic theory of granular flow and frictional models. The solid holdup and nozzle inlet air velocity effects on the gas−solid dynamics were assessed through a detailed analysis of the time-averaged volume fraction, the time-averaged velocity, the time-averaged streamlines, and the time-averaged vector field distributions of both phases. The simulated results were compared with the experimental observations available in the literature. The numerical simulations contributed to a better understanding of the particle−flow dynamics in a fluidized bed opposed gas jet mill which are of fundamental importance for the milling process performance.
69. LAPSE:2021.0626
Numerical Simulation on the Brake Effect of FAC-EMBr and EMBrRuler in the Continuous Casting Mold
July 19, 2021 (v1)
Subject: Modelling and Simulations
Keywords: continuous casting, electromagnetic brake, mold
The brake effect of the freestanding adjustable combination electromagnetic brake (FAC-EMBr) and EMBr ruler on the behavior of molten steel flow and the level fluctuation were investigated with the numerical method. The effects of the horizontal magnetic pole position (EMBr ruler), magnetic induction intensity, and casting speed on two types of electromagnetic brakes were studied. The numerical simulation results show that the magnetic field caused by the EMBr ruler is mainly distributed under the submerged entry nozzle (SEN), and it is very weak nearby the meniscus area. After the FAC-EMBr is applied, the magnetic field is mainly distributed in the area below the submerged entry nozzle, the upper roll region, and in the meniscus region. The application of the electromagnetic brake can effectively suppress the impact of the jet and decrease the molten steel velocity in the meniscus area. The brake effect of the EMBr ruler on the behavior of the molten steel flow and the level fluctuati... [more]
70. LAPSE:2021.0625
Improved Statistical Pattern Analysis Monitoring for Complex Multivariate Processes Using Empirical Likelihood
July 19, 2021 (v1)
Subject: Numerical Methods and Statistics
Keywords: empirical likelihood, higher-order statistics, moving window, statistical pattern analysis
This article developed an improved statistical pattern analysis (SPA) monitoring strategy for fault detection of complex multivariate processes using empirical likelihood. The technique based on statistical pattern analysis performs fault detection by inspecting change in the statistics of process variables (e.g., mean value, correlation coefficient, variance, kurtosis, etc.). It is capable of monitoring non-Gaussian or even nonlinear processes. However, the original SPA framework explicitly computes all the high-order statistics, which significantly increases the scale and dimensionality of the problem, especially in the case of complex multivariate processes. To alleviate this difficulty, we propose monitoring changes in the statistics with the same order using empirical likelihood, which is a widely used estimation method to construct confidence limits or regions for parameters with similar properties. As a result, changes in statistics of the same order can be translated into a sin... [more]
71. LAPSE:2021.0624
Numerical Simulation of Performance of an Air−Water Separator with Corrugated Plates for Marine Diesel Engines
July 19, 2021 (v1)
Subject: Modelling and Simulations
Keywords: air–water separator, corrugated plate, discrete phase model, pressure drop, separation efficiency
For low speed diesel engines under severe ocean conditions, high efficiency air−water separators must be equipped to separate excess moisture contained in the air and reduce the corrosion. Optimal design of air−water separator is an indispensable part in the development of marine main engines. In view of the complex gas−liquid two-phase turbulent motion within an air−water separator with corrugated plates, a mathematical model is established and numerical simulations of flow field, droplet trajectory and secondary transport are realized. The separation efficiency and pressure drop of the air−water separator under different structure parameters and different working conditions are studied. The results show that reducing the spacing of corrugated plate is helpful to improve the separation efficiency. The bending and hydrophobic hooks of the corrugated channel are important to improve the separation efficiency. The separation of droplet is mainly concentrated on the first two stages of th... [more]
72. LAPSE:2021.0623
Multi-Aspect Comparison of Ethyl Acetate Production Pathways: Reactive Distillation Process Integration and Intensification via Mechanical and Chemical Approach
July 19, 2021 (v1)
Subject: Process Design
Keywords: auxiliary reaction, energy-economy-safety aspects, ethyl acetate, ethylene oxide, process integration and intensification, Reactive Distillation
This paper provides a multi-aspect comparison of selected methods of ethyl acetate production and shows the possibility of further reactive distillation process integration and sophisticated intensification including process stream regeneration. The production pathways were selected with respect to their practical applicability and sufficient experimental and feasibility studies already published. A total of four case studies were designed and compared: conventional process set-up (ethyl acetate is produced in a chemical reactor) is designed as a base case study; reactive distillation with a separation unit is derived from the conventional process set-up. The mechanical and chemical approach to reactive distillation process intensification and integration were assumed: reactive distillation column with a stripper and reactive distillation column with an auxiliary chemical reaction (ethylene oxide hydration). Process models were compiled in the Aspen Plus software. Complex process flows... [more]
73. LAPSE:2021.0622
Modeling and Design of the Automatic Pressure Regulating Valve in the Foam Firefighting System
July 19, 2021 (v1)
Subject: Modelling and Simulations
Keywords: automatic pressure balancing valve, foam firefighting system, in-line balanced pressure (ILBP) proportioner, mathematical model, Simulation
This paper presents a novel design of the automatic pressure balancing valve, used in the in-line balanced pressure (ILBP) proportioner for the foam firefighting system, at a required percentage of solution. Featured in a four-chamber configuration with a double-acting diaphragm actuator, it can automatically maintain the foam concentrate pressure with the pressure in the supply water pipeline, within a precision level of 0.02 MPa (or 1.3%), under the design operating condition. The static characteristics at the equilibrium state have been discussed in terms of poppet displacement with reference to the geometrical dimensions and operating pressures of the valve. The dynamic response of the valve during the startup has been examined through building the mathematical model of the forces on the valve and solving it numerically using MATLAB. The results show that the response time of the valve is always less than 0.01 s, which fully satisfies the stability and hysteresis requirement. The p... [more]
74. LAPSE:2021.0621
Sulfatide-Rich Liposome Uptake by a Human-Derived Neuroblastoma Cell Line
July 19, 2021 (v1)
Subject: Biosystems
Keywords: drug delivery system, LDL receptor, liposomes, neuroblastoma, sulfoglycosphingolipids
Liposomes are bilayer membrane vesicles that can serve as vehicles for drug delivery. They are a good alternative to free drug administration that provides cell-targeted delivery into tumors, limiting the systemic toxicity of chemotherapeutic agents. Previous results from our group showed that an astrocytoma cell line exhibits selective uptake of sulfatide-rich (SCB) liposomes, mediated by the low-density lipoprotein receptor (LDL-R). The goal of this study was to assess the uptake of liposomes in a neuroblastoma cell line. For this purpose, we used two types of liposomes, one representing a regular cell membrane (DOPC) and another rich in myelin components (SCB). An astrocytoma cell line was used as a control. Characterization of liposome uptake and distribution was conducted by flow cytometry and fluorescence microscopy. Similar levels of LDL-R expression were found in both cell lines. The uptake of SCB liposomes was higher than that of DOPC liposomes. No alterations in cell viabilit... [more]
75. LAPSE:2021.0620
Rapid Two Stage Anaerobic Digestion of Nejayote through Microaeration and Direct Interspecies Electron Transfer
July 19, 2021 (v1)
Subject: Food & Agricultural Processes
Keywords: anaerobic digestion, direct interspecies electron transfer, granular activated carbon, microaeration, nejayote, Peptoclostridium
Corn is one of the main food products in Mexico. The elaboration of corn-derived products generates wastewater with a high organic load (nejayote). Anaerobic digestion is an indicated treatment for wastewater with high organic loads. The results of this study show that the application of microaeration in the hydrolysis-fermentative reactor increased the percentage of volatile fatty acids (VFA) available in the medium by 62%. The addition of a conductive material, such as granulated activated carbon (GAC), promotes DIET (Direct interspecies electrons transfer) in the methanogenic UASB reactor increasing the methane yield by 55%. Likewise, a great diversity of exoelectrogenic bacteria, with the ability to donate electrons DIET mechanisms, were developed in the GAC biofilm, though interestingly, Peptoclostridium and Clostridium (17.3% and 12.75%, respectively) were detected with a great abundance in the GAC biofilm. Peptoclostridium has not been previously reported as a participant in DIE... [more]