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Records added in 2022
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51. LAPSE:2022.0112
Commercial Thermal Technologies for Desalination of Water from Renewable Energies: A State of the Art Review
October 30, 2022 (v1)
Subject: Other
Keywords: desalination, multi effect distillation, multi stage flash, renewable energies, vapor compression distillation
Thermal desalination is yet a reliable technology in the treatment of brackish water and seawater; however, its demanding high energy requirements have lagged it compared to other non-thermal technologies such as reverse osmosis. This review provides an outline of the development and trends of the three most commercially used thermal or phase change technologies worldwide: Multi Effect Distillation (MED), Multi Stage Flash (MSF), and Vapor Compression Distillation (VCD). First, state of water stress suffered by regions with little fresh water availability and existing desalination technologies that could become an alternative solution are shown. The most recent studies published for each commercial thermal technology are presented, focusing on optimizing the desalination process, improving efficiencies, and reducing energy demands. Then, an overview of the use of renewable energy and its potential for integration into both commercial and non-commercial desalination systems is shown. Fi... [more]
52. LAPSE:2022.0111
Low-Viscosity Ether-Functionalized Ionic Liquids as Solvents for the Enhancement of Lignocellulosic Biomass Dissolution
October 30, 2022 (v1)
Subject: Materials
Keywords: Biomass, dissolution, ionic liquids, Optimization, RSM, ultrasonic
Due to the substantial usage of fossil fuels, the utilization of lignocellulosic biomass as renewable sources for fuels and chemical production has been widely explored. The dissolution of lignocellulosic biomass in proper solvents is vital prior to the extraction of its important constituents, and ionic liquids (ILs) have been found to be efficient solvents for biomass dissolution. However, the high viscosity of ILs limits the dissolution process. Therefore, with the aim to enhance the dissolution of lignocellulosic biomass, a series of new ether-functionalized ILs with low viscosity values were synthesized and characterized. Their properties, such as density, viscosity and thermal stability, were analyzed and discussed in comparison with a common commercial IL, namely 1-butyl-3-methylimidazolium chloride (BMIMCl). The presence of the ether group in the new ILs reduces the viscosity of the ILs to some appreciable extent in comparison to BMIMCl. 1-2(methoxyethyl)-3-methylimidazolium ch... [more]
53. LAPSE:2022.0110
Matching Optimization of a Mixed Flow Pump Impeller and Diffuser Based on the Inverse Design Method
October 30, 2022 (v1)
Subject: Optimization
Keywords: diffuser, flow field, impeller, inverse design method, matching optimization
When considering the interaction between the impeller and diffuser, it is necessary to provide logical and systematic guidance for their matching optimization. In this study, the goal was to develop a comprehensive matching optimization strategy to optimize the impeller and diffuser of a mixed flow pump. Some useful tools and methods, such as the inverse design method, computational fluid dynamics (CFD), design of experiment, surrogate model, and optimization algorithm, were used. The matching optimization process was divided into two steps. In the first step, only the impeller was optimized. Thereafter, CFD analysis was performed on the optimized impeller to get the circulation and flow field distribution at the outlet of the impeller. In the second step of optimization, the flow field and circulation distribution at the inlet of the diffuser were set to be the same as the optimized impeller outlet. The results show that the matching optimization strategy proposed in this study is eff... [more]
54. LAPSE:2022.0109
Fault Detection of Diesel Engine Air and after-Treatment Systems with High-Dimensional Data: A Novel Fault-Relevant Feature Selection Method
October 30, 2022 (v1)
Subject: System Identification
Keywords: canonical correlation analysis, data-driven, diesel engine, Fault Detection, variable selection
In order to reduce pollutants of the emission from diesel vehicles, complex after-treatment technologies have been proposed, which make the fault detection of diesel engines become increasingly difficult. Thus, this paper proposes a canonical correlation analysis detection method based on fault-relevant variables selected by an elitist genetic algorithm to realize high-dimensional data-driven faults detection of diesel engines. The method proposed establishes a fault detection model by the actual operation data to overcome the limitations of the traditional methods, merely based on benchmark. Moreover, the canonical correlation analysis is used to extract the strong correlation between variables, which constructs the residual vector to realize the fault detection of the diesel engine air and after-treatment system. In particular, the elitist genetic algorithm is used to optimize the fault-relevant variables to reduce detection redundancy, eliminate additional noise interference, and im... [more]
55. LAPSE:2022.0108
Forecasting Quantitative Risk Indicators of Investors in Projects of Biohydrogen Production from Agricultural Raw Materials
October 30, 2022 (v1)
Subject: Optimization
Keywords: biohydrogen, decarbonization, Hydrogen, market value
Hydrogen is increasingly considered as an environmentally friendly energy source as it stores a large amount of chemical energy per unit mass (142 MJ·kg−1) that can be released without the emission of combustion by-products. The presented research is based on simulation modeling of biohydrogen production projects from agricultural waste. Based on the probability theory and mathematical statistics, the models of the variable market value of biohydrogen and natural gas are substantiated. The results of the research indicate that in 2019, projects regarding the production of biohydrogen from agricultural raw materials were mostly unprofitable for the investors. However, starting in 2030, the forecasted return on investment in biohydrogen production projects from agricultural raw materials indicates that such projects will be profitable for investors, and the number and scale of such projects will significantly increase worldwide.
56. LAPSE:2022.0107
Energy Management in Smart Building by a Multi-Objective Optimization Model and Pascoletti-Serafini Scalarization Approach
October 30, 2022 (v1)
Subject: Energy Management
Keywords: energy management, mixed binary linear programming, multi-objective optimization problem, Pareto front, Pascoletti-Serafini approach, smart building
Generally, energy management in smart buildings is formulated by mixed-integer linear programming, with different optimization goals. The most targeted goals are the minimization of the electricity consumption cost, the electricity consumption value from external power grid, and peak load smoothing. All of these objectives are desirable in a smart building, however, in most of the related works, just one of these mentioned goals is considered and investigated. In this work, authors aim to consider two goals via a multi-objective framework. In this regard, a multi-objective mixed-binary linear programming is presented to minimize the total energy consumption cost and peak load in collective residential buildings, considering the scheduling of the charging/discharging process for electric vehicles and battery energy storage system. Then, the Pascoletti-Serafini scalarization approach is used to obtain the Pareto front solutions of the presented multi-objective model. In the final, the pe... [more]
57. LAPSE:2022.0105
Analysis of the Heat Balance of a Metal Hydride Separator Used for the Separation of Hydrogen from Syngas
October 30, 2022 (v1)
Subject: Modelling and Simulations
Keywords: Energy, heat exchanger, modelling and simulation
The present article discusses the potential for hydrogen separation using a metal hydride separator, which facilitates the generation of hydrogen contained in syngas following the thermal recovery of wastes. The article provides a detailed description of the separator heat balance using analytical calculations and optimised calculations, and by applying numerical methods. The proposed concept of a separator intended for hydrogen separation from syngas offers a solution to a problem associated with the use of metal hydride alloy powders; in particular, their low thermal conductivity. In order to eliminate big temperature differences in the alloy, a heat transfer intensifier was implemented in the metal hydride alloy volume; the intensifier was made of metal and exhibited high thermal conductivity. For the purpose of comparing the thermal fields, the first stage comprised the creation of a numerical simulation of hydrogen absorption without the use of an intensifier. Subsequently, three... [more]
58. LAPSE:2022.0104
Influence of Metal Oxides and Their Precursors on the Composition of Final Products of Aquathermolysis of Raw Ashalchin Oil
October 25, 2022 (v1)
Subject: Materials
Keywords: aquathermolysis, carbonate, hydrothermal conversion of heavy oil, kaolin, metal oxides, mineral compounds, precursors
Experiments were conducted simulating hydrothermal conversion of heavy oil in the presence of carbonate, kaolin, Al2O3, Ni2+ and Cu2+, NiO mixed with poly-α-olefins, C6H8O7, C2H4O2 at 290−375 °C and 10−135 bar. Al2O3, carbonate at 375 °C and 135 bar, accelerated the resin degradation. Experiments with carbonate at 350 °C and 10 bar showed no significant composition changes. NiSO4, CuSO4, kaolin mineral, at 350 °C and 78 bar, accelerated decomposition of resins (from 35.6% to 32.5%). Al2O3 and carbonate at 290 °C and 14 bar led to the destruction of asphaltenes (from 6.5% to 4.7% by weight), which were adsorbed on the surface of carbonate. Al2O3, NiO, poly-α-olefins at 350 °C and 78 bar accelerated C−C bond cracking of high-boiling asphaltenes. C6H8O7, rock-forming carbonate, at 360 °C and 14 bar, contributed to the polymerization and polycondensation of hydrocarbons with the formation of additional resins. C2H4O2 and kaolin at 360 °C and 12 bar affected the reduction in the resin conte... [more]
59. LAPSE:2022.0103
Integration of Gasification and Solid Oxide Fuel Cells (SOFCs) for Combined Heat and Power (CHP)
October 25, 2022 (v1)
Subject: Process Design
Keywords: gasification, solid oxide fuel cells (SOFC), syngas conditioning
This paper reviews the most recent information about the main operations to produce energy from carbonaceous materials, namely biomass and wastes through the integration of gasification, syngas cleaning and solid oxide fuel cells (SOFCs), which have shown to be a good option for combined heat and power (CHP) production, due to high efficiency and low environmental impact. However, some challenges still need to be overcome, mainly when mixed feedstocks with high contents of hazardous contaminants are used, thus syngas cleaning and conditioning is of major importance. Another drawback is SOFC operation, hence new materials especially for the anode has been proposed and tested. An overall process to produce CHP by gasification integration with SOFC is proposed.
60. LAPSE:2022.0102
Integrating Machine Learning, Radio Frequency Identification, and Consignment Policy for Reducing Unreliability in Smart Supply Chain Management
October 25, 2022 (v1)
Subject: Other
Keywords: environment, Machine Learning, radio frequency identification, smart supply chain management, unreliability
Adopting smart technologies for supply chain management leads to higher profits. The manufacturer and retailer are two supply chain players, where the retailer is unreliable and may not send accurate demand information to the manufacturer. As an advanced smart technology, Radio Frequency Identification (RFID) is implemented to track and trace each product’s movement on a real-time basis in the inventory. It takes this supply chain to a smart supply chain management. This research proposes a Machine Learning (ML) approach for on-demand forecasting under smart supply chain management. Using Long-Short-Term Memory (LSTM), the demand is forecasted to obtain the exact demand information to reduce the overstock or understock situation. A measurement for the environmental effect is also incorporated with the model. A consignment policy is applied where the manufacturer controls the inventory, and the retailer gets a fixed fee along with a commission for selling each product. The manufacturer... [more]
61. LAPSE:2022.0101
Carbonaceous Adsorbents Derived from Agricultural Sources for the Removal of Pramipexole Pharmaceutical Model Compound from Synthetic Aqueous Solutions
October 25, 2022 (v1)
Subject: Materials
Keywords: activated carbons, Adsorption, kiwi peels, orange peels, pharmaceuticals, sucrose, tea waste
The aim of the present study was to synthesize various samples of activated carbon (AC) from different agricultural sources as precursors, like orange peels, tea stalks, and kiwi peels, as well as sucrose. The synthesis of AC was achieved with chemical activation using H3PO4 and KOH. The produced AC samples were tested as adsorbents for the removal of a pharmaceutical model compound, pramipexole dihydrochloride (PRM), from synthetic aqueous synthetic solutions. The produced-from-sucrose AC presented the higher yield of synthesis (~58%). The physicochemical features of the materials were analyzed by FTIR spectroscopy, N2 physisorption, and SEM imaging. More specifically, the AC sample derived from sucrose (SG-AC) had the highest specific surface area (1977 m2/g) with the total pores volume, mesopores volume, and external surface area being 1.382 cm3/g, 0.819 cm3/g, and 751 m2/g, respectively. The effect of the initial pH and PRM concentration were studied, while the equilibrium results... [more]
62. LAPSE:2022.0100
The Air and Sewage Pollutants from Biological Waste Treatment
October 25, 2022 (v1)
Subject: Other
Keywords: biological treatment, chemical oxygen demand, odorant concentration, odour concentration, olfactometry, technological sewage
The mechanical-biological waste treatment plants (MBTP), which include the municipal waste biogas plants, have an important role in sustainable urban development. Some plants are equipped with a sewage pre-treatment plant, which is then directed to the sewerage system and the treatment plant. Others, on the other hand, have only a non-drainage tank. The parameters of technological sewage (TS) or processing technology could reduce sewage contamination rates. In addition to the quality of sewage from waste treatment plants, the emission of odours is also an important problem, as evidenced by the results obtained over the sewage pumping station tank. The conducted statistical analysis shows a significant positive correlation between odour concentration (cod) and volatile organic compounds (VOCs). Analysing the individual compounds, a high positive correlation was also found—the strongest being between H2S, NH3 and VOCs. In the case of sewage compounds, the insignificant correlation betwee... [more]
63. LAPSE:2022.0099
Effect of Storage Conditions and Time on the Polyphenol Content of Wheat Flours
October 25, 2022 (v1)
Subject: Food & Agricultural Processes
Keywords: antioxidant activity, phenolic extracts, storage conditions, storage time, whole wheat flour
Whole wheat flour possesses many nutritional properties because of its abundant bioactive components which are affected by cultivar, but little attention is paid to its relationship with storage conditions. In this study, phenolic extracts of whole wheat flour from four cultivars stored under different conditions (aerated and under vacuum) and different times (0, 2, 4, 8 weeks) were obtained. The total polyphenol (TPC) and flavonoid (TFC) contents, composition of phenolic acids, and antioxidant activities (AA) of phenolic extracts were evaluated. The results showed that Verna exhibited the highest levels of TPC, TFC, and AA for both storage conditions among the four cultivars. Moisture content, TFC, and AA fluctuated during storage. After 8 weeks, the TPC, TFC, and AA decreased with respect to Week 0 in all the cultivars. The TPC losses ranged between 16.39% and 20.88% and TFC losses from 14.08% to 31.18%. The AA losses were approximately 30% from the DPPH assay, but no significant los... [more]
64. LAPSE:2022.0098
Tiny Cold Atmospheric Plasma Jet for Biomedical Applications
October 25, 2022 (v1)
Subject: Other
Keywords: biomedical applications, cold atmospheric plasma, tiny plasma jet
Conventional plasma jets for biomedical applications tend to have several drawbacks, such as high voltages, high gas delivery, large plasma probe volume, and the formation of discharge within the organ. Therefore, it is challenging to employ these jets inside a living organism’s body. Thus, we developed a single-electrode tiny plasma jet and evaluated its use for clinical biomedical applications. We investigated the effect of voltage input and flow rate on the jet length and studied the physical parameters of the plasma jet, including discharge voltage, average gas and subject temperature, and optical emissions via spectroscopy (OES). The interactions between the tiny plasma jet and five subjects (de-ionized (DI) water, metal, cardboard, pork belly, and pork muscle) were studied at distances of 10 mm and 15 mm from the jet nozzle. The results showed that the tiny plasma jet caused no damage or burning of tissues, and the ROS/RNS (reactive oxygen/nitrogen species) intensity increased wh... [more]
65. LAPSE:2022.0097
Enhanced Anti-Fouling Behavior and Performance of PES Membrane by UV Treatment
October 25, 2022 (v1)
Subject: Other
Keywords: anti-fouling membranes, green solvent, hydrophilicity, membrane-surface modification, polarclean, UV-treatment, water treatment
An easy method to prepare hydrophilic PES membranes with anti-fouling properties was developed by UV-polymerization of poly vinyl pirrolidone (PVP) on membrane surfaces. The modified membrane surfaces were analyzed by ATR-FTIR, and the new hydrophilic nature of the membranes was determined by contact angle measurements. The novel membranes were prepared using Rhodiasolv® Polarclean as a green solvent and compared with a control PES membrane, without the exposure at the hydrophilization procedure. The influences of the UV lamp distance (15 and 30 cm) and the exposure time (0 cm to 60 cm) were evaluated. All membranes were characterized in terms of surface morphology, porosity, pore size, and pure water permeability (PWP). The treated membranes resulted in an increase in hydrophilicity and in improved performances in terms of PWP and foulant rejection. In particular, an anti-fouling test was performed using a solution of 100 mg/L of humic acid (HA) as a model foulant. The UV-treated memb... [more]
66. LAPSE:2022.0096
Improved Glucose Recovery from Sicyos angulatus by NaOH Pretreatment and Application to Bioethanol Production
October 25, 2022 (v1)
Subject: Other
Keywords: bioethanol, pretreatment, Sicyos angulatus, sodium hydroxide
As greenhouse gases and environmental pollution become serious, the demand for alternative energy such as bioethanol has rapidly increased, and a large supply of biomass is required for bioenergy production. Lignocellulosic biomass is the most abundant on the planet and a large part of it, the second-generation biomass, has the advantage of not being a food resource. In this study, Sicyos angulatus, known as an invasive plant (harmful) species, was used as a raw material for bioethanol production. In order to improve enzymatic hydrolysis, S. angulatus was pretreated with different NaOH concentration at 121 °C for 10 min. The optimal NaOH concentration for the pretreatment was determined to be 2% (w/w), and the glucan content (GC) and enzymatic digestibility (ED) were 46.7% and 55.3%, respectively. Through NaOH pretreatment, the GC and ED of S. angulatus were improved by 2.4-fold and 2.5-fold, respectively, compared to the control (untreated S. angulatus). The hydrolysates from S. angul... [more]
67. LAPSE:2022.0092
Prediction of Different Crude Oil Properties from FTIR Data with Statistical Methods, Deep and Shallow Neural Networks
October 21, 2022 (v2)
Subject: Numerical Methods and Statistics
Keywords: Chemometric Methods, Crude Oil Properties, Deep Neural Network, FTIR, Shallow Neural Network, Statistical Methods
In recent years, Fourier Transform InfraRed (FTIR) spectrometry has been widely used to estimate different characteristics and contents of materials in many fields. Even though numerous works have been published in this area, it has still been difficult to suggest a global method that can predict the properties of crude oils from different resources based solely on FTIR data. In this study, we compare the application of several methods in order to predict particular important properties (i.e., viscosity, density, total sulfur content, total acid number, etc.) of crude oil samples from seven different Canadian oil fields. We employed chemometric methods such as Partial Least Squares regression (PLS) and principal component regression (PCR) and compared the results to the performance of neural networks (NN) with a different number of layers. These methods were evaluated by calculating the coefficient of determination (R2) and prediction root mean squared errors (RMSE). Although less comp... [more]
68. LAPSE:2022.0091
Prediction of Amines Thermal Degradation in CO2 Capture Process Using Intelligent Techniques
October 19, 2022 (v1)
Subject: Modelling and Simulations
Keywords: Amines, Carbon Dioxide Capture, intelligent model, statistical analysis, thermal degradation
Mitigation of carbon emissions is an important step to achieve the climate change goals. Amine-based post-combustion CO2 capture (PCC) process is a promising technology, and many commercial projects have been developed based on different capture mechanisms governing in various carbon capture and storage (CCS) processes. The thermally regenerative amine-based PCC is a traditional technology, which consists of an absorber to capture CO2 from the flue gas and a desorber to strip CO2 from the CO2-rich. Although there have been substantial improvements in the industrial applications of amines technology, further developments are still required owing to significant energy requirement, high capital cost, and amine degradation. One of the most critical issues in the amine-based PCC process is the degradation of solvent, which occurs by the transformation of amines into other chemical components by thermal degradation and oxidative degradation. In the thermal degradation, the amines react with... [more]
69. LAPSE:2022.0090
High-Resolution Non-Contact Microwave Sensor for Water-Cut Measurements
October 19, 2022 (v1)
Subject: Other
Keywords: non-contact sensing, planar microwave sensor, production monitoring, water cut measurement
A novel, real-time, non-contact, non-invasive and high-sensitivity planar microwave sensor is developed for water cut measurements of crude oil samples. This sensor demonstrates the capability of measuring water cut of bitumen in real-time, which is of low-cost and eliminates the hurdles of current measurement techniques, prevents loss of production, and paves the way for oil field automation. The platform of the proposed sensor is based on a passive split ring resonator-based sensor with a defected ground gap coupled transmission line as the reader. The performance of the microwave sensor has been verified with varying water concentration in oil samples. The non-contact nature and high-resolution of the proposed structure enables monitoring of water cut in the full range.
70. LAPSE:2022.0089
Deep Chemometrics using One Dimensional Convolutional Neural Networks for Predicting Crude Oil Properties from FTIR Spectral Data
October 19, 2022 (v1)
Subject: Other
Keywords: Crude Oil Properties, FTIR, Neural Network architectures, One Dimensional Convolutional Neural Network
The determination of physicochemical properties of crude oils is a very important and time-intensive process that needs elaborate laboratory procedures. Over the last few decades, several correlations have been developed to estimate these properties, but they have been very limited in their scope and range. In recent years, methods based on spectral data analysis have been shown to be very promising in characterising petroleum crude. In this work, the physicochemical properties of crude oils using FTIR spectrums are predicted. A total of 107 samples of FTIR spectral data consisting of 6840 wavenumbers is used. One Dimensional convolutional neural networks (CNNs) were used with FTIR spectral data as the one-dimensional input and Keras and TensorFlow were used for model building. The Root Mean Square Error decreased from 160 to around 60 for viscosity when compared to previous machine learning methods like PLS, PCR, and PLS-GA on the same data. The important hyper-parameters of the CNN w... [more]
71. LAPSE:2022.0088
Interactions between process design and process control: Passive cooling in a micro refinery process
October 31, 2022 (v2)
Subject: Process Control
Keywords: micro refinery, passive cooling, process control
A micro refinery unit at Polytechnique Montreal converts natural gas to diesel range fuel as the main product in two high pressure and high temperature reacting units. First, it transforms methane to syngas by catalytic partial oxidation (CPOX) at 20 bar and 800⁰C. Then, it produces the medium-chain hydro-carbons from syngas by Fischer-Tropsch (FT) reaction at 20 bar and 300⁰C.
The aim of this study is to evaluate the impact of passive intercooling on the performance and robustness of a pre-set control configuration for this sequence of interconnected chemical reactors. We simulate the whole process in Aspen Plus v8.4 and first design a PI temperature controller for the Fischer-Tropsch re-actor in Aspen Plus Dynamics. As the FT process is highly exothermic, the controller is essential to properly remove the heat generated in the reactor. Despite being feasible in simulations, the closed-loop results suffer from many shortcomings, notably with respect to process constraints.
The i... [more]
The aim of this study is to evaluate the impact of passive intercooling on the performance and robustness of a pre-set control configuration for this sequence of interconnected chemical reactors. We simulate the whole process in Aspen Plus v8.4 and first design a PI temperature controller for the Fischer-Tropsch re-actor in Aspen Plus Dynamics. As the FT process is highly exothermic, the controller is essential to properly remove the heat generated in the reactor. Despite being feasible in simulations, the closed-loop results suffer from many shortcomings, notably with respect to process constraints.
The i... [more]
72. LAPSE:2022.0081
Combined Heat and Power System with Zero Carbon Emission by Integrating Catalytic Methane Pyrolysis and Carbon Conversion
October 14, 2022 (v1)
Subject: Other
Keywords: Carbon capture and In-Situ Conversion, Combined Heat and Power System, Methane Pyrolysis
Many industrial plants require electricity and high temperature thermal energy which are typically generated by burning hydrocarbon fuels. This study proposes an energy system that produces electricity and thermal energy by burning hydrocarbons without emitting CO2 through integration of catalytic methane pyrolysis (CMP), carbon capture and in-situ conversion (CCISC), methanol synthesis as well as combined heat and power (CHP) system. The system can eliminate CO2 emissions by industrial plants and residential areas and produce methanol and carbon black as chemical by-products, in addition to producing electricity and thermal energy. Result shows that the maximum net electricity efficiency can reach 52%.
73. LAPSE:2022.0087
On the Effectiveness of Heat-Exchanger Bypass Control
October 18, 2022 (v1)
Subject: Process Control
Keywords: bypass control, heat exchangers, heat-transfer control, process control, process design, process dynamics, temperature control
In heat exchangers with bypassing, a fraction of the flowrate of one fluid (typically the one whose temperature needs to be controlled tightly) bypasses the exchanger and mixes right after the exchanger outlet with the fraction flowing through the exchanger. The advantages of this configuration are long known. Among them, the most significant is that it can improve heat-transfer control because the temperature dynamics is significantly faster than in a standard heat-exchanger configuration. Additionally, it can increase the rangeability of the process wherein the heat exchanger operates. Existing rules of thumb do not provide univocal indications for assigning the design bypass flowrate. In this study, using a simple graphical representation of steady-state heat and mass balances originally proposed for conventional heat-exchanger design, we clarify why and under which design conditions bypass control can be effective. Increased rangeability results from the fact that the heat-exchange... [more]
74. LAPSE:2022.0086
The Effect of a Peptide Substrate Containing an Unnatural Branched Amino Acid on Chymotrypsin Activity
October 18, 2022 (v1)
Subject: Materials
Keywords: 7-amino-4-methylcoumarin, chymotrypsin, fluorescent probe, peptide, specificity, unnatural amino acid
7-Amino-4-methylcoumarin (AMC) is a low molecular weight fluorescent probe that can be attached to a peptide to enable the detection of specific proteases, such as chymotrypsin, expressed in certain diseases. Because this detection depends on the specificity of the protease toward the peptidyl AMC, the development of specific substrates is required. To investigate the specificity of chymotrypsin, peptidyl AMC compounds incorporating four different amino acid residues were prepared by liquid-phase synthesis. Two unnatural amino acids, 2-amino-4-ethylhexanoic acid (AEH) and cyclohexylalanine (Cha), were used to investigate the substrate specificity as these amino acids have structures different from natural amino acids. AEH was synthesized using diethyl acetamidemalonate as a starting material. The substrate containing Cha had high hydrophobicity and showed a high reaction velocity with chymotrypsin. Although the AEH substrate with a branched side chain had high hydrophobicity, it showed... [more]
75. LAPSE:2022.0085
A Mini Review on Antiwetting Studies in Membrane Distillation for Textile Wastewater Treatment
October 18, 2022 (v1)
Subject: Other
Keywords: membrane antifouling, membrane distillation, polymeric membranes, textile wastewater
The textile industry is an important contributor to the growth of the global economy. However, a huge quantity of wastewater is generated as a by-product during textile manufacturing, which hinders the ongoing development of textile industry in terms of environmental sustainability. Membrane distillation (MD), which is driven by thermal-induced vapor pressure difference, is being considered as an emerging economically viable technology to treat the textile wastewater for water reuse. So far, massive efforts have been put into new membrane material developments and modifications of the membrane surface. However, membrane wetting, direct feed solution transport through membrane pores leading to the failure of separation, remains as one of the main challenges for the success and potential commercialization of this separation process as textile wastewater contains membrane wetting inducing surfactants. Herein, this review presents current progress on the MD process for textile wastewater t... [more]