Records Added in October 2022
Records added in October 2022
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Showing records 26 to 50 of 95. [First] Page: 1 2 3 4 Last
Tiny Cold Atmospheric Plasma Jet for Biomedical Applications
Zhitong Chen, Richard Obenchain, Richard E. Wirz
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]
Enhanced Anti-Fouling Behavior and Performance of PES Membrane by UV Treatment
Francesca Russo, Maria Bulzomì, Emanuele Di Nicolò, Claudia Ursino, Alberto Figoli
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]
Improved Glucose Recovery from Sicyos angulatus by NaOH Pretreatment and Application to Bioethanol Production
Hyung-Eun An, Kang Hyun Lee, Ye Won Jang, Chang-Bae Kim, Hah Young Yoo
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]
Prediction of Different Crude Oil Properties from FTIR Data with Statistical Methods, Deep and Shallow Neural Networks
Shahla Alizadeh, Souvik Ta, Ajay. K. Ray, Lakshminarayanan Samavedham
October 21, 2022 (v2)
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]
Prediction of Amines Thermal Degradation in CO2 Capture Process Using Intelligent Techniques
Abbas Azarpour, Sohrab Zendehboudi
October 19, 2022 (v1)
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]
High-Resolution Non-Contact Microwave Sensor for Water-Cut Measurements
Bushra Kamal, Zahra Abbasi, Hassan Hassanzadeh
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.
Deep Chemometrics using One Dimensional Convolutional Neural Networks for Predicting Crude Oil Properties from FTIR Spectral Data
Souvik Ta, Shahla Alizadeh, Lakshminarayanan Samavedham, Ajay K. Ray
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]
Interactions between process design and process control: Passive cooling in a micro refinery process
Mahdi Sharifian, Nicolas Hudon, Gregory S. Patience
October 31, 2022 (v2)
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]
Combined Heat and Power System with Zero Carbon Emission by Integrating Catalytic Methane Pyrolysis and Carbon Conversion
Tianyue Li, Jian Long, Wenli Du, Feng Qian, Vladimir Mahalec
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%.
On the Effectiveness of Heat-Exchanger Bypass Control
Nicolò Soave, Massimiliano Barolo
October 18, 2022 (v1)
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]
The Effect of a Peptide Substrate Containing an Unnatural Branched Amino Acid on Chymotrypsin Activity
Yuuki Yamawaki, Tomoki Yufu, Tamaki Kato
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]
A Mini Review on Antiwetting Studies in Membrane Distillation for Textile Wastewater Treatment
Guang Yang, Jianhua Zhang, Mingguo Peng, Erdeng Du, Yong Wang, Guocheng Shan, Ling Ling, Hui Ding, Stephen Gray, Zongli Xie
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]
Techno-Economic Analysis of a Hyaluronic Acid Production Process Utilizing Streptococcal Fermentation
Rafael G. Ferreira, Adriano R. Azzoni, Maria Helena Andrade Santana, Demetri Petrides
October 18, 2022 (v1)
Keywords: Fermentation, hyaluronic acid, process simulation, Streptococcus, Technoeconomic Analysis
Hyaluronic acid (HA) is a polysaccharide of alternating d-glucuronic acid and N-acetyl-d-glucosamine residues present in the extracellular matrix of connective, epithelial, and nervous tissues. Due to its singular hydrating, rheological and adhesive properties, HA has found numerous cosmetic and medical applications. However, techno-economic analyses of high value-added bioproducts such as HA are scarce in the literature. Here, we present a techno-economic analysis of a process for producing HA using Streptococcus zooepidemicus, simulated in SuperPro Designer. In the baseline scenario, HA is produced by batch fermentation, reaching 2.5 g/L after 24 h. It is then centrifuged, diafiltered, treated with activated carbon and precipitated with isopropanol. The product is suitable for topical formulations and its production cost was estimated as 1115 $/kg. A similar scenario, based on fed-batch culture and assuming a titer of 5.0 g/L, led to a lower cost of 946 $/kg. Moreover, in two additio... [more]
Techno-Economic Analysis of Automated iPSC Production
Bastian Nießing, Raphael Kiesel, Laura Herbst, Robert H. Schmitt
October 18, 2022 (v1)
Subject: Other
Keywords: automation, digitalization, economic analysis, induced pluripotent stem cells (iPSC), StemCellFactory
Induced pluripotent stem cells (iPSC) open up the unique perspective of manufacturing cell products for drug development and regenerative medicine in tissue-, disease- and patient-specific forms. iPSC can be multiplied almost without restriction and differentiated into cell types of all organs. The basis for clinical use of iPSC is a high number of cells (approximately 7 × 107 cells per treatment), which must be produced cost-effectively while maintaining reproducible and high quality. Compared to manual cell production, the automation of cell production offers a unique chance of reliable reproducibility of cells in addition to cost reduction and increased throughput. StemCellFactory is a prototype for a fully automated production of iPSC. However, in addition to the already tested functionality of the system, it must be shown that this automation brings necessary economic advantages. This paper presents that fully automated stem cell production offers economic advantages in addition t... [more]
Insights into the Supercritical CO2 Extraction of Perilla Oil and Its Theoretical Solubility
Ming-Chi Wei, Chia-Sui Wang, Da-Hsiang Wei, Yu-Chiao Yang
October 18, 2022 (v1)
Subject: Other
Keywords: density-based models, essential oils, hydrodistillation, Perilla frutescens, perillaldehyde, supercritical carbon dioxide extraction
In the current research, the supercritical carbon dioxide (SCCO2) procedure was used to extract volatile oils from perilla leaves. The yields of the volatile oils and the four main constituents, limonene, perillaldehyde, β-caryophyllene, and (Z,E)-α-farnesene obtained by the SCCO2 procedure were 1.31-, 1.12-, 1.04-, 1.05-, and 1.07-fold higher than those obtained by the hydrodistillation technique, respectively. Furthermore, the duration and temperature of extraction were 40 min and 45 °C lower, respectively, in the former procedure compared to the latter technique. These advantages reveal that SCCO2 not only obtains high-quality extracts, but also meets the requirements of green environmental protection. The theoretical solubilities of the volatile oils acquired by the SCCO2 dynamic extraction at various temperatures and pressures were 1.385 × 10−3−8.971 × 10−3 (g oil/g CO2). Moreover, the three density-based models were well correlated with these theoretical solubility data, with a h... [more]
Liquid-Phase Removal of Methylene Blue as Organic Pollutant by Mesoporous Activated Carbon Prepared from Water Caltrop Husk Using Carbon Dioxide Activation
Yu-Quan Lin, Wen-Tien Tsai
October 13, 2022 (v1)
Subject: Materials
Keywords: adsorptive removal, CO2 activation, kinetic modeling, mesoporous activated carbon, methylene blue, water caltrop husk
In this work, a mesoporous activated carbon (AC) was prepared from a unique lignocellulosic biomass (water caltrop husk) in triplicate using a single-step physical activation process at lower temperature (i.e., 750 °C) and longer holding time (i.e., 90 min). Based on the pore properties and adsorption properties for removal of methylene blue (MB) as organic pollutant, the results proved that the resulting AC possesses a mesoporous feature with the Brunauer−Emmett−Teller (BET) surface area of 810.5 m2/g and mesopore volume of about 0.13 cm3/g. Due to its fast adsorption rate and maximal adsorption capacity fitted (126.6 mg/g), the mesoporous carbon material could be used as an excellent adsorbent for liquid-phase removal of MB. In addition, the pseudo-second-order model is well suited for describing the adsorption system between the cationic adsorbate and the resulting AC with oxygen surface groups.
Position Deviation Control of Drilling Machine Using a Nonlinear Adaptive Backstepping Controller Based on a Disturbance Observer
Huifu Ji, Songyong Liu
October 13, 2022 (v1)
Keywords: deviation control, drilling machine, nonlinear adaptive backstepping controller disturbance observer, parameter uncertainties
Thin coal seam mining is a development direction to solve the problem of energy supply at this stage, which cannot be realized by small working space, low automation, and drilling deviation. In this paper, a nonlinear adaptive backstepping controller based on a disturbance observer is proposed and used on a coal auger for position tracking control to achieve directional drilling. Firstly, a nonlinear dynamic model for the deflection control mechanism is built with the consideration of parameter uncertainties and external disturbances. Then, the parameter uncertainty and external disturbance are regarded as a system compound disturbance. Furthermore, a disturbance observer is designed to estimate the system compound disturbance and a nonlinear adaptive backstepping controller was proposed to compensate the system compound disturbance. The upper bound of the compound disturbance, which can effectively reduce the chattering in the directional control process, cannot be obtained easily. A... [more]
Technologies and Extraction Methods of Polyphenolic Compounds Derived from Pomegranate (Punica granatum) Peels. A Mini Review
Dimitrios Lampakis, Prodromos Skenderidis, Stefanos Leontopoulos
October 13, 2022 (v1)
Keywords: bioactivity, extraction technologies, functional foods, pomegranate peels
The interest in using plant by-product extracts as functional ingredients is continuously rising due to environmental and financial prospects. The development of new technologies has led to the achievement of aqueous extracts with high bioactivity that is preferable due to organic solvents nonuse. Recently, widely applied and emerging technologies, such as Simple Stirring, Pressure-Applied Extraction, Enzymatic Extraction, Ultrasound-Assisted Extraction, Pulsed Electric Fields, High Hydrostatic Pressure, Ohmic Heating, Microwave Assistant Extraction and the use of “green” solvents such as the deep eutectic solvents, have been investigated in order to contribute to the minimization of disadvantages on the extraction of bioactive compounds. This review is focused on bioactive compounds derived from pomegranate (Punica granatum) peels and highlighted the most attractive extraction methods. It is believed that these findings could be a useful tool for the pomegranate juices industry to app... [more]
A Review on Temperature Control of Proton Exchange Membrane Fuel Cells
Qinghe Li, Zhiqiang Liu, Yi Sun, Sheng Yang, Chengwei Deng
October 13, 2022 (v1)
Subject: Other
Keywords: cold start, cooling system, proton exchange membrane fuel cell, temperature control, temperature distribution
This paper provides a comprehensive review of the temperature control in proton exchange membrane fuel cells. Proton exchange membrane (PEM) fuel cells inevitably emit a certain amount of heat while generating electricity, and the fuel cell can only exert its best performance in the appropriate temperature range. At the same time, the heat generated cannot spontaneously keep its temperature uniform and stable, and temperature control is required. This part of thermal energy can be classified into two groups. On the one hand, the reaction heat is affected by the reaction process; on the other hand, due to the impedance of the battery itself to the current, the ohmic polarization loss is caused to the battery. The thermal effect of current generates Joule heat, which is manifested by an increase in temperature and a decrease in battery performance. Therefore, it is necessary to design and optimize the battery material structure to improve battery performance and adopt a suitable cooling... [more]
Design, Modelling, and Experimental Validation of a Scalable Continuous-Flow Hydrothermal Liquefaction Pilot Plant
Ib Johannsen, Björn Kilsgaard, Viktor Milkevych, Dale Moore
October 13, 2022 (v1)
Keywords: biofuel, chemical process engineering, heat transfer, Hydrothermal Liquefaction, non-isothermal fluid flow, pilot plant, plug flow reactor, process modelling, sustainable fuel
In this study, the design and practical implementation of a novel, scalable plug-flow pilot plant for hydrothermal liquefaction of organic feedstock is presented. The overall discussion comprises the system’s design, process modelling, and simulation, as well as results for an experimental validation of the proposed design with a focus on fluid dynamics and heat transfer. The design criteria take into account the scalability of the plug-flow processing system, optimized non-isothermal flow conditions of highly viscous liquids in a tubular system at harsh process conditions, specifically high pressure and medium temperatures, and overall maintenance suitability. A novel forced flow oscillation system as well as unique heat exchange design to reduce the energy consumption during system operation, maximize local flow mixing, and minimize plugging are proposed and experimentally tested. To achieve a better understanding and optimization of Hydrothermal Liquefaction (HTL) (and other) proces... [more]
Conceptual Design of a Negative Emissions Polygeneration Plant for Multiperiod Operations Using P-Graph
Jean Pimentel, Ákos Orosz, Kathleen B. Aviso, Raymond R. Tan, Ferenc Friedler
October 13, 2022 (v1)
Keywords: carbon dioxide removal, multiperiod optimization, negative emissions technologies, power-to-x, process network synthesis
Reduction of CO2 emissions from industrial facilities is of utmost importance for sustainable development. Novel process systems with the capability to remove CO2 will be useful for carbon management in the future. It is well-known that major determinants of performance in process systems are established during the design stage. Thus, it is important to employ a systematic tool for process synthesis. This work approaches the design of polygeneration plants with negative emission technologies (NETs) by means of the graph-theoretic approach known as the P-graph framework. As a case study, a polygeneration plant is synthesized for multiperiod operations. Optimal and alternative near-optimal designs in terms of profit are identified, and the influence of network structure on CO2 emissions is assessed for five scenarios. The integration of NETs is considered during synthesis to further reduce carbon footprint. For the scenario without constraint on CO2 emissions, 200 structures with profit... [more]
Biocatalytic Approach for Novel Functional Oligoesters of ε-Caprolactone and Malic Acid
Diana Maria Dreavă, Ioana Cristina Benea, Ioan Bîtcan, Anamaria Todea, Eugen Șișu, Maria Puiu, Francisc Peter
October 13, 2022 (v1)
Subject: Materials
Keywords: biobased monomers, enzymatic polymerization, green polymers, lipase, malic acid, oligoesters, ε-caprolactone
Biocatalysis has developed in the last decades as a major tool for green polymer synthesis. The particular ability of lipases to catalyze the synthesis of novel polymeric materials has been demonstrated for a large range of substrates. In this work, novel functional oligoesters were synthesized from ε-caprolactone and D,L/L-malic acid by a green and sustainable route, using two commercially available immobilized lipases as catalysts. The reactions were carried out at different molar ratios of the comonomers in organic solvents, but the best results were obtained in solvent-free systems. Linear and cyclic oligomeric products with average molecular weights of about 1500 Da were synthesized, and the formed oligoesters were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis. The oligoester synthesis was not enantioselective in the studied reaction conditions. The operational stability of both biocatalysts (Novozyme 435 and GF-... [more]
Study on Nonlinear Stochastic Process of Deck Slamming on Floating Offshore Platform
Hyun-Seung Nam, Yonghwan Kim
October 13, 2022 (v1)
Subject: Other
Keywords: deck slamming, Hermite-moment method, joint probability distribution, nonlinear stochastic process, slamming occurrence
In this paper, a semi-analytic method is introduced to predict the deck-slamming probability and corresponding loads. This method is based on a nonlinear statistical approach that takes into account the linear and second-order components of the relative wave elevation up to the second order. The linear and second-order wave elevation is assumed to be a two-term Volterra series. The joint probability density function of the relative wave elevation and velocity are formulated using the Hermite-moment method, and the probability distributions of the wave crest and relative wave velocity are calculated. These probability distributions are verified using the data sampled from the linear and second-order relative wave elevation. Based on this formulation, the probabilities of deck slamming and slamming-induced loads are estimated. This method is applied to a tension leg platform (TLP) model, and the effects of the second-order component of the relative wave elevation on the deck slamming are... [more]
Bimetallic Pt-Co Nanoparticle Deposited on Alumina for Simultaneous CO and Toluene Oxidation in the Presence of Moisture
Peng Peng, Jun Li, Shengpeng Mo, Qi Zhang, Taiming Shen, Qinglin Xie
October 13, 2022 (v1)
Subject: Materials
Keywords: bimetallic alloy, catalytic oxidation, moisture, Pt-based catalysts, Toluene
Carbon monoxide (CO) and hydrocarbons (HCs) generally have competitive adsorption on the active site of noble-metal nano-catalysts, thus developing an effective way to reduce the passivation of competitive reaction with each other is an urgent problem. In this study, we successfully synthesized transition metal-noble metal (Pt-M) alloys via introducing inexpensive metal elements (M = Ni, Co and Cu) into Pt particles and then deposited on alumina support to form Pt-based catalysts. Subsequently, we choose CO and toluene as polluting gases to evaluate the catalytic activities of Pt-M/Al2O3 catalysts. Introducing inexpensive metal elements (M = Ni, Co, and Cu) significantly changed the physicochemical properties and catalytic activities of these Pt-based catalysts. It can be found that the Pt-Co/Al2O3 catalyst exhibited outstanding catalytic activity for CO and toluene oxidation under mixed gas atmosphere, compared with other Pt-based catalysts, which is due to the higher dispersity, more... [more]
Biotransformation of Citrus Waste-I: Production of Biofuel and Valuable Compounds by Fermentation
Neelima Mahato, Kavita Sharma, Mukty Sinha, Archana Dhyani, Brajesh Pathak, Hyeji Jang, Seorin Park, Srinath Pashikanti, Sunghun Cho
October 13, 2022 (v1)
Subject: Other
Keywords: bio-waste, bioethanol, biofuel, biogas, biotransformation, citrus waste, Fermentation
Citrus is the largest grown fruit crop on the globe with an annual production of ~110−124 million tons. Approximately, 45−55% of the whole fruit post-processing is generally discarded as waste by the food processing industries. The waste is a huge problem to the environment in terms of land and water pollution along with displeasure from aesthetic viewpoint and spread of diseases owing to its huge content of fermentable sugars. The waste can be utilized as a raw material feedstock for producing a number of valuable chemicals and products, such as bioethanol, biogas, bio-oil, organic acids, enzymes, and so on. The production of these chemicals from waste biomass gives an inexpensive alternative to the harsh chemicals used during industrial synthesis processes as well as the possibility of controlling pollution from the waste discarded to the environment. The derived chemicals can be further utilized in the production of industrially important chemicals, as solvents and building blocks o... [more]
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