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Records Added in September 2019
Records added in September 2019
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Showing records 26 to 50 of 102. [First] Page: 1 2 3 4 5 Last
Choline-Based Ionic Liquids as Media for the Growth of Saccharomyces cerevisiae
Magaret Sivapragasam, Cecilia Devi Wilfred, Joshua Raj Jaganathan, Sooridarsan Krishnan, Wan Azlina Wan Ab Wan Karim Ghani
September 23, 2019 (v1)
Subject: Biosystems
Keywords: biotoxicity, choline, ionic liquids, Saccharomyces cerevisiae
Ionic liquids (ILs) have garnered great attention as alternative solvents in many biological reactions and applications. However, its unknown toxicity is in line with the challenges to use it for biological applications. In this study, three choline based Ionic Liquids—choline saccharinate (CS), choline dihydrogen phosphate (CDHP), and choline tryptophanate (CT) were assessed for their suitability on the growth of Saccharomyces cerevisiae. The ILs were incorporated into the growth media of S. cerevisiae (defined as synthetic media) to access its potential as a substitute to conventional media. The compatibility of the synthetic media was evaluated based on the toxicity (EC50), growth curve, and glucose profile. The results showed that the incorporation of CDHP and CS did promote the growth of S. cerevisiae with a rapid glucose consumption rate. The growth of S. cerevisiae with the media composition of yeast extract, peptone, and CS showed improvement of 13%. We believe that these obser... [more]
An Overview of Recent Advances in State-of-the-Art Techniques in the Demulsification of Crude Oil Emulsions
M. A. Saad, Mohammed Kamil, N. H. Abdurahman, Rosli Mohd Yunus, Omar I. Awad
September 23, 2019 (v1)
Subject: Materials
Keywords: crude oil, demulsification, emulsion, mechanism, stability
The processing of crude oil often requires the extraction of a large amount of water. Frequently, crude oil is mixed with water to form water-in-crude oil emulsions as the result of factors such as high shear at the production wellhead and surface-active substances that are naturally present in crude oil. These emulsions are undesirable and require demulsification to remove the dispersed water and associated inorganic salts in order to meet production and transportation specifications. Additionally, the demulsification of these crude oil emulsions mitigates corrosion and catalyst poisoning and invariably maximizes the overall profitability of crude oil production. Recently, there has been growing research interest in developing workable solutions to the difficulties associated with transporting and refining crude oil emulsions and the restrictions on produced water discharge. Therefore, this paper reviews the recent research efforts on state-of-the-art demulsification techniques. First... [more]
Sustainable Green Procedure for Extraction of Hesperidin from Selected Croatian Mandarin Peels
Stela Jokić, Silvija Šafranko, Martina Jakovljević, Ana-Marija Cikoš, Nikolina Kajić, Filip Kolarević, Jurislav Babić, Maja Molnar
September 23, 2019 (v1)
Subject: Biosystems
Keywords: by-product, deep eutectic solvents, hesperidin, mandarin peel, Optimization
The peels of Citrus reticulata Blanco mandarin cultivars of different Croatian varieties (Zorica rana, Chahara, Okitsu, Kuno) were extracted using 15 different choline chloride-based deep eutectic solvents (DESs) at 50 °C for 30 min and with 20% water addition. The extracts were analyzed by high performance liquid chromatography with diode array detection (HPLC-DAD) to determine the most suitable DES for the extraction of hesperidin in the samples. The screening results indicated that choline chloride: acetamide (1:2) provided the most efficient hesperidin extraction (112.14 mg/g of plant), while choline chloride:citric acid (1:1) solvent showed the lowest hesperidin yield (1.44 mg/g of plant). The Box−Behnken design was employed to optimize extraction parameters for each variety of mandarin peel, including extraction time, temperature and water content on hesperidin extraction. The results indicated that hesperidin content in mandarin peels was completely variety-dependent. Being a no... [more]
Optimization of Total Anthocyanin Content, Stability and Antioxidant Evaluation of the Anthocyanin Extract from Vietnamese Carissa Carandas L. Fruits
Xuan Tien Le, Minh Thuan Huynh, Tri Nhut Pham, Van Thai Than, Tran Quoc Toan, Long Giang Bach, Nguyen Quang Trung
September 23, 2019 (v1)
Subject: Biosystems
Keywords: anthocyanin, antioxidant properties, Carissa carandas L., extract conditions, stability
In this study, the extraction of anthocyanin colorant from karanda fruit (Carissa carandas L.) was carried out and optimized with multiple single factor assays. Selected conditions for yield maximization consisted of ripen fruits with black-purple color, material size of thin slices (1.0−1.5 mm), solvent of EtOH 50%, material/ solvent ratio of 1:3, temperature of 50 °C, extraction time of 45 min, and two extraction cycles. The anthocyanin content in the extract was 277.2 mg/L, which is equivalent to 9.33 mg anthocyanin per gram of dry material. Aqueous solutions of the extract and dried extracts from Carissa carandas fruit were evaluated for stability at two temperature conditions, namely room temperature (30 ± 2 °C) and 45 °C. The temperature exerted great impact on color change, anthocyanin content and the degree of polymerization of anthocyanin. Aqueous solutions of extract with citric acid (3.0−5.0 g/L) were generally more color stable and less anthocyanin degradable than those wit... [more]
Air-Conditioning Resource Management and Control Method based on Cloud Platform for Wind Power Consumption
Kaixin Liang, Jinying Yu, Xin Wu
September 23, 2019 (v1)
Keywords: air-conditioning grouping collaborative control, air-conditioning management, cloud control, wind power tracking
Air-conditionings have energy storage functions. Through reasonable aggregation control, the output tracking can be implemented for wind power with stronger fluctuation to enhance its utilization rate. Cloud technology and intelligent appliances enable the appliance vendor to implement information interaction with the air-conditioning through cloud platforms to realize flexible regulation. In this paper, a management and control method of air-conditioning based on cloud platform is established. Based on this structure, the air-conditionings are divided into several aggregation groups according to the similarity of parameters, and each group completes the consumption task collaboratively. The consumption evaluation model of the air-conditioning group is established. On this basis, the allocation problem on consumption task for the aggregated group is constructed to implement the optimal solution under the condition of guaranteeing the degree of completion and user comfort. Each group im... [more]
Spectroscopic Examination and Chemometric Analysis of Essential Oils Obtained from Peppermint Herb (Mentha piperita L.) and Caraway Fruit (Carum carvi L.) Subjected to Pulsed Electric Fields
Urszula Sadowska, Arkadiusz Matwijczuk, Agnieszka Niemczynowicz, Tomasz Dróżdż, Andrzej Żabiński
September 23, 2019 (v1)
Subject: Materials
Keywords: caraway fruit, chemometric analysis and spectroscopic studies, essential oils, peppermint herb, pulsed electric field, spectroscopic studies
In the food industry, the pulsed electric field (PEF) technique is used to support the process of extraction of various substances. The aim of this study was to analyze the effect of a number of PEF pulses applied to peppermint and caraway on both the content of essential oils (EO) and their spectroscopic properties. The examined herb species were placed in a special vessel in the working chamber of the device between two electrodes providing high voltage electric pulses. The pulses were delivered 0, 150, 250, and 350 times per a studied sample of each herb. Essential oils were then obtained by way of hydrodistillation. The infrared spectra for all samples were measured using an FTIR spectrometer in the spectral range of 3700−730 cm−1. The applied electric field of a predetermined number of pulses had no significant effect on the amount of distilled essential oil from caraway fruit, while in the case of peppermint, it caused a slight decrease in relation to the raw material not subject... [more]
Lipase Production by Solid-State Cultivation of Thermomyces Lanuginosus on By-Products from Cold-Pressing Oil Production
Marina Tišma, Toma Tadić, Sandra Budžaki, Marta Ostojčić, Anita Šalić, Bruno Zelić, Nghiep Nam Tran, Yung Ngothai, Volker Hessel
September 23, 2019 (v1)
Subject: Biosystems
Keywords: flax oil cake, hemp oil cake, hull-less pumpkin oil cake, lipase, solid-state fermentation, Thermomyces lanuginosus
This study shows that by-products obtained after cold-pressing oil production (flex oil cake, hemp oil cake, hull-less pumpkin oil cake) could be used as substrates for the sustainable and cost-effective production of lipase when cultivating Thermomyces lanuginosus under solid-state conditions (T = 45 °C, t = 9 days). Lipase showed optimum activity at T = 40 °C. The produced lipase extract was purified 17.03-folds with a recovery of 1% after gel chromatography. Three different batch experiments were performed in order to test the possibility of using the lipase in biodiesel production. Experiments were performed with a commercial, unpurified enzyme, and partially purified lipase with sunflower oil and methanol as substrates in a batch reactor at 40 °C. During the experiments, the operational stability of the enzyme was studied. The obtained results clearly showed that produced crude and purified lipase can be used for biodiesel production, but the process needs some additional optimiza... [more]
Online Operation Risk Assessment of the Wind Power System of the Convolution Neural Network (CNN) Considering Multiple Random Factors
Qingwu Gong, Si Tan, Yubo Wang, Dong Liu, Hui Qiao, Liuchuang Wu
September 23, 2019 (v1)
Keywords: CNN, equipment failure rate, load fluctuations, online operation risk assessment, operation pattern, uncertain wind power output
In order to solve the problem of the inaccuracy of the traditional online operation risk assessment model based on a physical mechanism and the inability to adapt to the actual operation of massive online operation monitoring data, this paper proposes an online operation risk assessment of the wind power system of the convolution neural network (CNN) considering multiple random factors. This paper analyzes multiple random factors of the wind power system, including uncertain wind power output, load fluctuations, frequent changes in operation patterns, and the electrical equipment failure rate, and generates the sample data based on multi-random factors. It uses the CNN algorithm network, offline training to obtain the risk assessment model, and online application to obtain the real-time online operation risk state of the wind power system. Finally, the online operation risk assessment model is verified by simulation using the standard network of 39 nodes of 10 machines New England syst... [more]
Separation of Protein-Binding Anthraquinones from Semen Cassiae Using Two-Stage Foam Fractionation
Linlin Ding, Yanyan Wang, Chuanjun Yue, Zeying Wu, Ye Sun, Min Wang, Rui Li
September 23, 2019 (v1)
Subject: Biosystems
Keywords: anthraquinones, foam fractionation, interaction, proteins, Semen Cassiae
Anthraquinones are compounds of high medicinal value in many plants. Based on their good protein binding affinity, foam fractionation was attempted to separate them using proteins in the aqueous extract of Semen Cassiae as collectors. Firstly, the interaction between anthraquinones and Semen Cassiae proteins has been analyzed by the Stem−Volmer equation with physcion as a standard. The results show that physcion had good interaction with the proteins via hydrophobic forces. More importantly, the proteins effectively assisted the foam fractionation of several anthraquinones including aurantio-obtusifolin, aloe-emodin, rhein, emodin, chrysophanol, and physcion. On this basis, a two-stage foam fractionation technology was developed for process intensification using a foam fractionation with vertical sieve trays (VSTs). VSTs, initial feed concentration of total anthraquinones, temperature, volumetric air flow rate and pore diameter of gas distributor had significant effects on enrichment r... [more]
Topological Characterization of Nanosheet Covered by C3 and C6
Sumiya Nasir, Fozia Bashir Farooq, Nazeran Idrees, Muhammad Jawwad Saif, Fatima Saeed
September 23, 2019 (v1)
Subject: Materials
Keywords: M-polynomial, nanosheet, Randic index, topological index, Zagreb index
A topological index of a graph is a single numeric quantity which relates the chemical structure with its underlying physical and chemical properties. Topological indices of a nanosheet can help us to understand the properties of the material better. This study deals with computation of degree-dependent topological indices like the Randic index, first Zagreb index, second Zagreb index, geometric arithmetic index, atom bond connectivity index, sum connectivity index and hyper Zagreb index of nanosheet covered by C3 and C6. Furthermore, M-polynomial of the nanosheet is also computed, which provides an alternate way to express the topological indices.
Towards the Grand Unification of Process Design, Scheduling, and Control—Utopia or Reality?
Baris Burnak, Nikolaos A. Diangelakis, Efstratios N. Pistikopoulos
September 23, 2019 (v1)
Keywords: integration, process control, process design, Scheduling
As a founder of the Process Systems Engineering (PSE) discipline, Professor Roger W.H. Sargent had set ambitious goals for a systematic new generation of a process design paradigm based on optimization techniques with the consideration of future uncertainties and operational decisions. In this paper, we present a historical perspective on the milestones in model-based design optimization techniques and the developed tools to solve the resulting complex problems. We examine the progress spanning more than five decades, from the early flexibility analysis and optimal process design under uncertainty to more recent developments on the simultaneous consideration of process design, scheduling, and control. This formidable target towards the grand unification poses unique challenges due to multiple time scales and conflicting objectives. Here, we review the recent progress and propose future research directions.
Workflow for Data Analysis in Experimental and Computational Systems Biology: Using Python as ‘Glue’
Melinda Badenhorst, Christopher J. Barry, Christiaan J. Swanepoel, Charles Theo van Staden, Julian Wissing, Johann M. Rohwer
September 23, 2019 (v1)
Keywords: enzyme kinetics, Jupyter notebook, kinetic modelling, Matplotlib, NMR spectroscopy, optimisation, parametrisation, PySCeS, SciPy, validation
Bottom-up systems biology entails the construction of kinetic models of cellular pathways by collecting kinetic information on the pathway components (e.g., enzymes) and collating this into a kinetic model, based for example on ordinary differential equations. This requires integration and data transfer between a variety of tools, ranging from data acquisition in kinetics experiments, to fitting and parameter estimation, to model construction, evaluation and validation. Here, we present a workflow that uses the Python programming language, specifically the modules from the SciPy stack, to facilitate this task. Starting from raw kinetics data, acquired either from spectrophotometric assays with microtitre plates or from Nuclear Magnetic Resonance (NMR) spectroscopy time-courses, we demonstrate the fitting and construction of a kinetic model using scientific Python tools. The analysis takes place in a Jupyter notebook, which keeps all information related to a particular experiment togeth... [more]
Adsorptive Removal of Pyridine in Simulation Wastewater Using Coke Powder
Qieyuan Gao, Lei Wang, Zhipeng Li, Yaqi Xie, Qiongqiong He, Yongtian Wang
September 23, 2019 (v1)
Keywords: adsorbent, adsorption thermodynamics, coke powder, pyridine
Pyridine is a toxic component in industrial wastewater, which is difficult to remove using conventional methods. In this study, the cost-effective coke powder was used to remove pyridine from a pyridine simulation wastewater. The removal efficiency and adsorption capacity of pyridine reached up to 67.32% and 0.4488 mg/g, respectively, at a coke powder concentration of 60 mg/L and an adsorption time of 30 min. The pyridine removal efficiency and adsorption capacity of coke powder reached saturation when the initial concentration was 40 mg/L. The pH of 2−12 in the solution was found to have little effect on the pyridine adsorption process of coke powder, while the coke powder with lower ash content was of better adsorbability for pyridine. The coke powder was regenerated by heat treatment, and reused for pyridine adsorption. It was found that the pyridine removal efficiency slightly decreased after nine times of reuse, in addition to a small cumulative weight loss rate of coke powder. Ad... [more]
Overview of Alternative Ethanol Removal Techniques for Enhancing Bioethanol Recovery from Fermentation Broth
Hamid Zentou, Zurina Zainal Abidin, Robiah Yunus, Dayang Radiah Awang Biak, Danil Korelskiy
September 23, 2019 (v1)
Keywords: Adsorption, bioethanol, Extraction, pervaporation, separation, stripping, unconventional, vacuum
This study aims at reviewing the alternative techniques for bioethanol recovery, highlighting its advantages and disadvantages, and to investigate the technical challenges facing these alternatives to be widely used. The findings showed that the integration of these techniques with the fermentation process did not meet a large acceptance in the industrial sector. The majority of conducted studies were mainly focusing on ethanol recovery from aqueous standard solution rather than the investigation of these techniques performance in fermentation-separation coupled system. In this context, pervaporation has received more attention as a promising alternative to distillation. However, some challenges are facing the integration of these techniques in the industrial scale as the fouling problem in pervaporation, the toxicity of solvent in liquid extraction, energy consumption in vacuum fermentation. It was also found that there is a lack of the technical economic analysis for these techniques... [more]
Ear Detection and Localization with Convolutional Neural Networks in Natural Images and Videos
William Raveane, Pedro Luis Galdámez, María Angélica González Arrieta
September 23, 2019 (v1)
Keywords: computer vision, convolutional neural network, ear detection, image recognition, video analysis
The difficulty in precisely detecting and locating an ear within an image is the first step to tackle in an ear-based biometric recognition system, a challenge which increases in difficulty when working with variable photographic conditions. This is in part due to the irregular shapes of human ears, but also because of variable lighting conditions and the ever changing profile shape of an ear’s projection when photographed. An ear detection system involving multiple convolutional neural networks and a detection grouping algorithm is proposed to identify the presence and location of an ear in a given input image. The proposed method matches the performance of other methods when analyzed against clean and purpose-shot photographs, reaching an accuracy of upwards of 98%, but clearly outperforms them with a rate of over 86% when the system is subjected to non-cooperative natural images where the subject appears in challenging orientations and photographic conditions.
Extraction Process, Identification of Fatty Acids, Tocopherols, Sterols and Phenolic Constituents, and Antioxidant Evaluation of Seed Oils from Five Fabaceae Species
Lan Phuong Doan, Thi Thuy Nguyen, Minh Quan Pham, Quoc Toan Tran, Quoc Long Pham, Dinh Quang Tran, Van Thai Than, Long Giang Bach
September 23, 2019 (v1)
Subject: Biosystems
Keywords: antioxidant activity, Fabaceae seed oils, fatty acids, phenolic, sterols, tocopherols
The present study aimed to extract seed oils and characterize the chemical composition, including fatty acid profiles, tocopherols, sterols, and total phenolics of oils and extracts from five Fabaceae seeds: Glycine soja, Vigna angularis, Phaseolus lunatus, Phaseolus vulgarisand, and Phaseolus coccineus. The composition and content of all substance layers in total lipids of the extracted seed oils from five Fabaceae species contain: polar lipid (PL), sterol (ST), diacylglycerol (DG), triacylglycerol (TG), free fatty acid (FFA), and hydrocarbon and wax (HC + W). Antioxidant activity determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method was also estimated. Among these examined samples, Phaseolus vulgarisand and Phaseolus coccineus seed oils showed high content of α-linolenic acid (59.39% and 49.38%, respectively). Linoleic acid was abundantly found in Vigna angularis (49.01%). Ferunic and caffeic acid, γ-tocopherol, and β-sistosterol were the main ingredients present in the speci... [more]
Effect of Dissolved Organic Matter on Agglomeration and Removal of CuO Nanoparticles by Coagulation
Rizwan Khan, Muhammad Ali Inam, Muhammad Akram, Ahmed Uddin, Sarfaraz Khan, Ick Tae Yeom
September 23, 2019 (v1)
Subject: Materials
Keywords: agglomeration, coagulation, copper oxide nanoparticles, dissolved organic matter, polyaluminum chloride
Engineered nanomaterials (ENMs), such as copper oxide nanoparticles (CuO NPs), are emerging as pollutants extensively used in many commercial and industrial applications, thus raising environmental concerns due to their release into water bodies. It is, therefore, essential to remove these pollutants from water bodies in order to minimize the potential threat to the aquatic environment and human health. The objective of this study was to investigate the removal of CuO NPs from waters by the coagulation process. This study also explored the efficiency of coagulation to remove hydrophobic/hydrophilic dissolved organic matter (DOM) and turbidity with varying polyaluminum chloride (PACl) doses. According to the results, a high concentration of DOM affects both the CuO NPs zeta potential and hydrodynamic diameter, thereby decreasing the agglomeration behavior. At effective coagulation zone (ECR), high removal of CuO NPs (>95%) was observed for all studied waters (hydrophobic and hydrophilic... [more]
Development of a Numerical Model for a Compact Intensified Heat-Exchanger/Reactor
Menglin He, Zetao Li, Xue Han, Michel Cabassud, Boutaib Dahhou
September 23, 2019 (v1)
Keywords: exothermal reaction, heat transfer, heat-exchanger/reactor, Modelling
A heat-exchanger/reactor (HEX reactor) is a kind of plug-flow chemical reactor which combines high heat transfer ability and chemical performance. It is a compact reactor designed under the popular trend of process intensification in chemical engineering. Previous studies have investigated its characteristics experimentally. This paper aimed to develop a general numerical model of the HEX reactor for further control and diagnostic use. To achieve this, physical structure and hydrodynamic and thermal performance were studied. A typical exothermic reaction, which was used in experiments, is modeled in detail. Some of the experimental data without reaction were used for estimating the heat transfer coefficient by genetic algorithm. Finally, a non-linear numerical model of 255 calculating modules was developed on the Matlab/Simulink platform. Simulations of this model were done under conditions with and without chemical reactions. Results were compared with reserved experimental data to sh... [more]
A Numerical Approach to Solve Volume-Based Batch Crystallization Model with Fines Dissolution Unit
Safyan Mukhtar, Muhammad Sohaib, Ishfaq Ahmad
September 23, 2019 (v1)
Keywords: orthogonal polynomials, quadrature method of moments, volume-based population balance model with fines dissolution
In this article, a numerical study of a one-dimensional, volume-based batch crystallization model (PBM) is presented that is used in numerous industries and chemical engineering sciences. A numerical approximation of the underlying model is discussed by using an alternative Quadrature Method of Moments (QMOM). Fines dissolution term is also incorporated in the governing equation for improvement of product quality and removal of undesirable particles. The moment-generating function is introduced in order to apply the QMOM. To find the quadrature abscissas, an orthogonal polynomial of degree three is derived. To verify the efficiency and accuracy of the proposed technique, two test problems are discussed. The numerical results obtained by the proposed scheme are plotted versus the analytical solutions. Thus, these findings line up well with the analytical findings.
Mathematical Modelling Forecast on the Idling Transient Characteristic of Reactor Coolant Pump
Xiuli Wang, Yajie Xie, Yonggang Lu, Rongsheng Zhu, Qiang Fu, Zheng Cai, Ce An
September 23, 2019 (v1)
Keywords: costing stopping, idling test, mathematical model, reactor coolant pump, vane
The idling behavior of the reactor coolant pump is referred to as an important indicator of the safe operation of the nuclear power system, while the idling transition process under the power failure accident condition is developed as a transient flow process. In this process, the parameters such as the flow rate, speed, and head of the reactor coolant pump are all nonlinear changes. In order to ensure the optimal idling behavior of the reactor coolant pump under the power cutoff accident condition, this manuscript takes the guide vanes of the AP1000 reactor coolant pump as the subject of this study. In this paper, the mathematical model of idling speed and flow characteristic curve of reactor coolant pump under the power failure condition were proposed, while the hydraulic modeling database of different vane structure parameters was modeled based on the orthogonal optimization schemes. Furthermore, based on the mathematical modeling framework of multiple linear regressions, the mathem... [more]
Discrete-Time Kalman Filter Design for Linear Infinite-Dimensional Systems
Junyao Xie, Stevan Dubljevic
September 23, 2019 (v1)
Keywords: boundary control, discretization, infinite-dimensional system, Kalman filter design, water hammer equation, wave equation
As the optimal linear filter and estimator, the Kalman filter has been extensively utilized for state estimation and prediction in the realm of lumped parameter systems. However, the dynamics of complex industrial systems often vary in both spatial and temporal domains, which take the forms of partial differential equations (PDEs) and/or delay equations. State estimation for these systems is quite challenging due to the mathematical complexity. This work addresses discrete-time Kalman filter design and realization for linear distributed parameter systems. In particular, the structural- and energy-preserving Crank−Nicolson framework is applied for model time discretization without spatial approximation or model order reduction. In order to ensure the time instance consistency in Kalman filter design, a new discrete model configuration is derived. To verify the feasibility of the proposed design, two widely-used PDEs models are considered, i.e., a pipeline hydraulic model and a 1D bounda... [more]
Do Bioreactor Designs with More Efficient Oxygen Supply to Ovarian Cortical Tissue Fragments Enhance Follicle Viability and Growth In Vitro?
Gerardo Catapano, Gionata Fragomeni, Giuseppe Falvo D’Urso Labate, Luigi De Napoli, Vincenza Barbato, Maddalena Di Nardo, Valentina Costanzo, Teresa Capriglione, Roberto Gualtieri, Riccardo Talevi
September 23, 2019 (v1)
Subject: Biosystems
Keywords: bioreactor, design, in vitro culture, ovarian tissue, oxygen, transport
Background: Autotransplantation of cryopreserved ovarian tissue is currently the main option to preserve fertility for cancer patients. To avoid cancer cell reintroduction at transplantation, a multi-step culture system has been proposed to obtain fully competent oocytes for in vitro fertilization. Current in vitro systems are limited by the low number and health of secondary follicles produced during the first step culture of ovarian tissue fragments. To overcome such limitations, bioreactor designs have been proposed to enhance oxygen supply to the tissue, with inconsistent results. This retrospective study investigates, on theoretical grounds, whether the lack of a rational design of the proposed bioreactors prevented the full exploitation of follicle growth potential. Methods: Models describing oxygen transport in bioreactors and tissue were developed and used to predict oxygen availability inside ovarian tissue in the pertinent literature. Results: The proposed theoretical analysi... [more]
Lanthanum Effect on Ni/Al2O3 as a Catalyst Applied in Steam Reforming of Glycerol for Hydrogen Production
Nuria Sánchez, José María Encinar, Sergio Nogales, Juan Félix González
September 23, 2019 (v1)
Keywords: biodiesel, Hydrogen, non-noble transition metals, Syngas, X-ray photoelectron spectroscopy
Nowadays, the massive production of biodiesel leads to a surplus of glycerol. Thus, new applications of this by-product are being developed. In this study, glycerol steam reforming was carried out with Ni catalysts supported on Al2O3 rings and La-modified Al2O3. The catalysts were characterized by N2 physical adsorption, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and thermogravimetry. Both catalysts were effective in glycerol steam reforming. However, Ni/Al2O3 activity decreased over reaction time. Ni/La2O3/Al2O3 showed the best stability during the reaction. In addition, the activity of the modified support, La2O3/Al2O3, was evaluated. The modification of the support lent catalytic properties to the solid. Some conditions such as catalyst arrangement (catalyst in the first or second reactor), space velocity, and reaction temperature were studied. The highest hydrogen production was obtained when half the amount of the catalyst was located in bot... [more]
Online Decision-Support Tool “TECHoice” for the Equipment Technology Choice in Sterile Filling Processes of Biopharmaceuticals
Haruku Shirahata, Sara Badr, Yuki Shinno, Shuta Hagimori, Hirokazu Sugiyama
September 23, 2019 (v1)
Keywords: MATLAB Production Server, multi-objective decision-making, parenteral manufacturing, process design, single-use technology, software development
In biopharmaceutical manufacturing, a new single-use technology using disposable equipment is available for reducing the work of change-over operations compared to conventional multi-use technology that use stainless steel equipment. The choice of equipment technologies has been researched and evaluation models have been developed, however, software that can extend model exposure to reach industrial users is yet to be developed. In this work, we develop and demonstrate a prototype of an online decision-support tool for the multi-objective evaluation of equipment technologies in sterile filling of biopharmaceutical manufacturing processes. Multi-objective evaluation models of equipment technologies and equipment technology alternative generation algorithms are implemented in the tool to support users in choosing their preferred technology according to their input of specific production scenarios. The use of the tool for analysis and decision-support was demonstrated using four productio... [more]
Preparation and Performance Analysis of Graphite Additive/Paraffin Composite Phase Change Materials
Wei Li, Yan Dong, Xu Zhang, Xueling Liu
September 23, 2019 (v1)
Subject: Materials
Keywords: composite phase change material, graphite additives, nanomaterials, thermal conductivity, thermal management
In the thermal energy storage system, the thermal properties of phase change materials (PCM) have a great influence on the system performance. In this paper, paraffin-based composite phase change material with different graphite additive (expanded graphite, EG; graphene, GR; and graphene oxide, GO) and different concentrations (0.5 to 2.0%) are manufactured by a two-step method combining mechanical agitation and ultrasonic vibration. The characteristics of charge/discharge processes are studied, and the thermophysical properties are measured by T-history method. The experimental results show that the thermal conductivity and heat charge rate of the composite PCM are effectively improved by adding the graphite additive to the PCM, and the addition of additives can improve the melting point of the material. When the same graphite additive is added, the higher the concentration, the higher the thermal conductivity of the composite PCM, and the latent heat decreases with the increase of co... [more]
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