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Showing records 964 to 988 of 1263. [First] Page: 1 36 37 38 39 40 41 42 43 44 Last
A Soft Curtailment of Wide-Area Central Air Conditioning Load
Leehter Yao, Lei Yao, Wei Hong Lim
March 12, 2020 (v1)
Keywords: air condition, chillers, demand response, direct load control, fuzzy linear programming, scheduling optimization
An innovative solution to provide a demand response for power system is proposed in this paper by considering the feasibility of two-way direct load control (TWDLC) of central air conditioning chiller system for wide-area in real-time manner. Particularly, the proposed TWDLC scheme is designed to tackle the load shedding ratio optimization problem for all under-controlled customers, aiming to satisfy the target load curtailment defined in each scheduling step. Another notable contribution of this work is the utilization of constraint loosening concept on actual load, curtailed to overcome the uncertainties of load reduction during TWDLC. Given the presence of fuzzy constraints, the proposed load shedding ratio optimization problem can be tackled using fuzzy linear programming. A delicate strategy is then formulated to transform the proposed fuzzy linear programming problem into a regular linear programming problem. A selection scheme used to obtain the feasible candidates set for load... [more]
Nonlinear Thermal Radiation and Chemical Reaction Effects on a (Cu−CuO)/NaAlg Hybrid Nanofluid Flow Past a Stretching Curved Surface
Naveed Ahmed, Fitnat Saba, Umar Khan, Syed Tauseef Mohyud-Din, El-Sayed M. Sherif, Ilyas Khan
March 12, 2020 (v1)
Keywords: (Cu−CuO)/NaAlg hybrid nanofluid, boundary layer, chemical reaction, curved stretching surface, heat and mass transfer, nonlinear thermal radiation, numerical results
The boundary layer flow of sodium alginate ( NaAlg ) based ( Cu − CuO ) hybrid nanofluid, over a curved expanding surface, has been investigated. Heat and mass transport phenomena have also been analyzed. Moreover, the impacts of chemical reaction, magnetic field and nonlinear thermal radiation are also a part of this study. This arrangement has great practical relevance, especially in the polymer and chemical industries. We have extended the Bruggeman model to make it capable of capturing the thermal conductivity of ( Cu − CuO ) / NaAlg hybrid nanofluid. We have employed some suitable transformations to obtain the governing system of nonlinear ODEs. Runge − Kutta − Fehlberg algorithm, accompanied by a shooting technique, has been employed to solve the governing system numerically. The changes in the flow and heat transfer distribution, due to various parameters, have been captured and portrayed in the form of graphs. It has been found that t... [more]
Detection of Drivers’ Anxiety Invoked by Driving Situations Using Multimodal Biosignals
Seungji Lee, Taejun Lee, Taeyang Yang, Changrak Yoon, Sung-Phil Kim
March 12, 2020 (v1)
Keywords: driver anxiety, emotion detection, multimodal biosignals
It has become increasingly important to monitor drivers’ negative emotions during driving to prevent accidents. Despite drivers’ anxiety being critical for safe driving, there is a lack of systematic approaches to detect anxiety in driving situations. This study employed multimodal biosignals, including electroencephalography (EEG), photoplethysmography (PPG), electrodermal activity (EDA) and pupil size to estimate anxiety under various driving situations. Thirty-one drivers, with at least one year of driving experience, watched a set of thirty black box videos including anxiety-invoking events, and another set of thirty videos without them, while their biosignals were measured. Then, they self-reported anxiety-invoked time points in each video, from which features of each biosignal were extracted. The logistic regression (LR) method classified single biosignals to detect anxiety. Furthermore, in the order of PPG, EDA, pupil, and EEG (easiest to hardest accessibility), LR classified ac... [more]
Possibility to Save Water and Energy by Application of Fresh Vegetables to Produce Supplemented Potato-Based Snack Pellets
Katarzyna Lisiecka, Agnieszka Wójtowicz
March 12, 2020 (v1)
Keywords: extrusion-cooking, process efficiency, snack pellets, specific mechanical energy, vegetables, water consumption
The aim of the study was to examine the effect of fresh vegetable addition on processing efficiency, and to ascertain the energy and water consumption during production of potato-based snack pellets. The extrusion-cooking process with a modified single screw extruder was applied at variable screw speeds and amounts of vegetable additives. A mixture of potato flakes, potato grits and starch was used as a basic recipe. The potato composition was supplemented with fresh pulp of onion, leek, kale and carrot in amounts of 2.5−30.0% as replacement of a related amount of potato starch. The water consumption, as well as processing indicators: the production efficiency, the specific mechanical energy (SME), and the total SME requirements during snack pellets processing at the laboratory scale were evaluated. As a result of this work, we found that the amount of applied vegetable additives had little impact on both processing efficiency and SME depending on the screw speeds applied. Moreover, we... [more]
Correction: Vachaparambil, K.J. Comparison of Surface Tension Models for the Volume of Fluid Method. Processes 2019, 7, 542
Kurian J. Vachaparambil, Kristian Etienne Einarsrud
March 12, 2020 (v1)
In Equations (2) and (3) [...]
Investigation of the Most Suitable Conditions for Dehydration of Tuckeroo (Cupaniopsis anacardioides) Fruits
Ngoc Minh Quynh Pham, Quan V. Vuong, Anh V. Le, Michael C. Bowyer, Christopher J. Scarlett
March 12, 2020 (v1)
Keywords: antioxidant, dehydration, drying, fruit, phytochemical, Tuckeroo
Tuckeroo (Cupaniopsis anacardioides) is an Australian native tree, possessing high level bioactivity and antioxidant activity. To prevent deterioration of active constituents, appropriate drying practices must be determined. This study comparatively evaluates the impact of a range of drying methods including freeze-, microwave-, vacuum-, hot air- and sun-drying on the physical, phytochemical and antioxidant characteristics of Tuckeroo fruit. Experimental results showed that the five drying methods had significant impact on the physicochemical properties and antioxidant activity of the fruits. Of the drying methods assessed, freeze drying best preserved Tuckeroo activity, recording higher total phenolic content (TPC) (81.88 mg gallic acid equivalent (GAE)/g), total flavonoids (TFC) (107.71 mg catechin equivalent (CAE)/g), proanthocyanidins (TPro) (83.86 mg CAE/g) and exhibited the strongest antioxidant capacity. However, vacuum drying at 65 kPa, 100 °C for 5 h is recommended for drying... [more]
3-D Modeling of Dehydration Kinetics and Shrinkage of Ellipsoidal Fermented Amazonian Cocoa Beans
Alessandra Adrover, Antonio Brasiello
March 12, 2020 (v1)
Keywords: 3-d modeling, cocoa beans, diffusion coefficient, drying kinetics, moving-boundary model
A recently proposed moving-boundary model for food isothermal dehydration was applied to analyze the dehydration kinetics of ellipsoidal cocoa beans, characterized by a moderate shrinkage and a non-uniform initial distribution of water content between the core and the shell of the bean. The aim is to predict the influence of air velocity and non-uniformity of the initial water distribution on the dehydration rates, as well as the temporal evolution of the water content in the core and in the shell and of the characteristic lengths of the ellipsoidal bean. The model proved capable of accurately describing the two-phases dehydration process: an initial fast dehydration of the shell, characterized by higher dehydration rates, followed by a slower dehydration of the core, characterized by a linear relationship j d = δ ( T ) X r between the dehydration rate j d and the moisture ratio X r . A shortcut method to estimate the effective water diffusivity D is also p... [more]
Liquid Biphasic System: A Recent Bioseparation Technology
Kuan Shiong Khoo, Hui Yi Leong, Kit Wayne Chew, Jun-Wei Lim, Tau Chuan Ling, Pau Loke Show, Hong-Wei Yen
March 12, 2020 (v1)
Keywords: aqueous biphasic system, aqueous two-phase system, biomolecules, liquid biphasic system, purification, recovery, separation
A well-known bioseparation technique namely liquid biphasic system (LBS) has attracted many researchers’ interest for being an alternative bioseparation technology for various kinds of biomolecules. The present review begins with an in-depth discussion on the fundamental principle of LBS and this is followed by the discussion on further development of various phase-forming components in LBS. Additionally, the implementation of various advance technologies to the LBS that is beneficial towards the efficiency of LBS for the extraction, separation, and purification of biomolecules was discussed. The key parameters affecting the LBS were presented and evaluated. Moreover, future prospect and challenges were highlighted to be a useful guide for future development of LBS. The efforts presented in this review will provide an insight for future researches in liquid-liquid separation techniques.
Modification of the Bacterial Cell Wall—Is the Bioavailability Important in Creosote Biodegradation?
Wojciech Smułek, Amanda Pacholak, Ewa Kaczorek
March 12, 2020 (v1)
Subject: Biosystems
Keywords: bacteria, bioavailability, biodegradation, creosote, PAHs
Creosote oil, widely used as a wood preservative, is a complex mixture of different polycyclic aromatic compounds. The soil contamination result in the presence of a specific microcosm. The presented study focuses on the most active strains involved in bioremediation of long-term creosote-contaminated soil. In three soil samples from different boreholes, two Sphingomonas maltophilia (S. maltophilia) and one Paenibacillus ulginis (P. ulginis) strain were isolated. The conducted experiments showed the differences and similarities between the bacteria strains capable of degrading creosote from the same contaminated area. Both S. maltophilia strains exhibit higher biodegradation efficiency (over 50% after 28 days) and greater increase in glutathione S-transferase activity than P. ulginis ODW 5.9. However, S. maltophilia ODW 3.7 and P. ulginis ODW 5.9 were different from the third of the tested strains. The growth of the former two on creosote resulted in an increase in cell adhesion to Con... [more]
CFD Simulation of Forced Recirculating Fired Heated Reboilers
Alon Davidy
March 12, 2020 (v1)
Keywords: Computational Fluid Dynamics, convective heat transfer, crude oil, fire heater, nucleate boiling, process simulation, radiative heat transfer, reboiler, thermo-physical properties, two phase flow
An advanced algorithm has been developed in order to analyze the performance of re-boiling process of crude oil flowing inside reboilers tubes. The proposed model is composed from Heptane fire heater and a tube array. The heat flux produced from burner is transferred to the crude oil flowing inside the tube. The computational model is composed of two phases—Simulation of fire by using Fire Dynamics Simulator software (FDS) version 5.0 and then a nucleate boiling computation of the crude oil. FDS code is formulated based on CFD (Computational Fluid Dynamics) of fire heater. The thermo-physical properties (such as: thermal conductivity, heat capacity, surface tension, viscosity) of the crude oil were estimated by using empirical correlations. The thermal heat transfer to evaporating two-phase crude oil mixture occur by bubble generation at the wall (nucleate boiling) has been calculated by using Chen correlation. It has been assumed that the overall convective heat transfer coefficient i... [more]
Enhancing the Pore Properties and Adsorption Performance of Cocoa Pod Husk (CPH)-Derived Biochars via Post-Acid Treatment
Wen-Tien Tsai, Chien-Hung Hsu, Yu-Quan Lin, Chi-Hung Tsai, Wen-Shing Chen, Yao-Tsung Chang
March 12, 2020 (v1)
Subject: Materials
Keywords: adsorption performance, biochar, cocoa pod husk, energy dispersive X-ray spectroscopy, Fourier Transform infrared spectroscopy, pore property
In this work, the cocoa pod husk (CPH) was converted into biochar products at higher carbonization temperatures (i.e., 400−800 °C). The pore and chemical properties of the resulting biochars and its post-leaching biochars by acid washing, including specific surface area, total pore volume, pore size distribution, true density, and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and Fourier Transform infrared spectroscopy (FTIR) were studied. Based on the pore properties, pyrolysis temperature at around 800 °C seemed to have the most profound impact on the pore development for producing biochar, where its Brunauer−Emmet−Teller (BET) surface area is 101 m2/g. More noticeably, more pores in the CPH-based biochar could be significantly created during the acid-washing, resulting in an increase of BET surface area from 101 to 342 m2/g. According to the data on the EDS and FTIR, the resulting biochars seemed to have oxygen-containing functional groups on the surfac... [more]
A Numerical Study on the Flow Mechanism of Performance Improvement of a Wide-Angle Diffuser by Inserting a Short Splitter Vane
Xu Meng, Zhigang Zuo, Michihiro Nishi, Shuhong Liu
March 12, 2020 (v1)
Keywords: flow mechanism, flow simulation, loss analysis, splitter vane, wide-angle diffuser
Usage of a wide-angle diffuser may result in unfavorable separated flow and a significant diffuser loss. To improve the performance of the diffusers, inserting short splitter vanes is known as a useful method that has been demonstrated experimentally. Regarding the role of the vane in the diffuser flow, Senoo & Nishi (1977) qualitatively explained that the lift force acting on the vane should be a key factor. However, its quantitative verification remains since then. To challenge this issue, numerical simulations of incompressible flow in a wide angle of 28° two-dimensional diffuser with and without a short splitter vane were conducted in the present study. An improvement of pressure-recovery by the vane and oscillatory flows in the diffuser are reasonably reproduced from comparison with the experimental results made by Cochran & Kline (1958). It is also found that the lift force acting on the vane varies periodically in an opposite phase with the detachment point moved back and forth... [more]
Anaerobic Digestate Treatment Selection Model for Biogas Plant Costs and Emissions Reduction
Dinko Đurđević, Ivona Hulenić
March 12, 2020 (v1)
Keywords: biogas, decision support system model, economic sustainability, GHG mitigation, waste management
Agriculture is one of the leading sectors on the global level contributing to greenhouse gas (GHG) emissions increase. With the utilization of biogas production technology within the agriculture sector, ecological benefits could be achieved, with immediate economic profit. Therefore, to retain economic profit and environmental sustainability, implementation of bioeconomy principles is of key importance. This paper examines four options of digestate treatment, which is identified as one of the highest operational cost for the biogas plant. A simple and robust model in Excel Solver was developed to determine the best solution for minimising GHG emissions and maximise profit for the biogas plant operator, through an upgrade of the plant with digestate treatment technologies. The model was implemented on a case of a Croatian biogas plant and the best solution in terms of GHG reduction and profit increase proved to be fertilizer production (Option 1), through a crystallization process of st... [more]
Acknowledgement to Reviewers of Processes in 2019
Processes Editorial Office
March 12, 2020 (v1)
Subject: Other
The editorial team greatly appreciates the reviewers who have dedicated their considerable timeand expertise to the journal’s rigorous editorial process over the past 12 months, regardless ofwhether the papers are finally published or not [...]
Multi-Criteria Decision Making (MCDM) Model for Supplier Evaluation and Selection for Oil Production Projects in Vietnam
Chia-Nan Wang, Hsiung-Tien Tsai, Thanh-Phong Ho, Van-Thanh Nguyen, Ying-Fang Huang
March 12, 2020 (v1)
Keywords: AHP, DEA, MCDM, oil industry, SCOR, supplier selection
The following research utilizes Multi-Criteria Decision Making (MCDM) in order to build a business strategy to reduce product costs, improve competitiveness, focus on production planning based on actual operating capacity and flexible adjustment according to the market, maximize the labor productivity of technology workshops, reduce costs and inventory, and focus on producing many petrochemical products and products of high economic value. Selecting the right materials supplier is of paramount importance to the success of the organization as a whole. Supplier evaluation and the selection of a suitable supplier is a complex problem in which the decision maker must consider both qualitative and quantitative factors. Multi-Criteria Decision Making Models are an effective tool used to solve complex selection issues including multiple criteria and options, especially for qualitative variables. Thus, the author proposes an MCDM model including the Supply Chain Operation Reference (SCOR) mode... [more]
Removal of Agrochemicals from Waters by Adsorption: A Critical Comparison among Humic-Like Substances, Zeolites, Porous Oxides, and Magnetic Nanocomposites
Antonello Marocco, Gianfranco Dell’Agli, Filomena Sannino, Serena Esposito, Barbara Bonelli, Paolo Allia, Paola Tiberto, Gabriele Barrera, Michele Pansini
March 12, 2020 (v1)
Subject: Materials
Keywords: Adsorption, agrochemicals, humic-like substances, magnetic nanocomposites, porous oxides, zeolites
The use of humic-like substances, zeolites, various porous oxides (i.e., Al, Fe, or Si oxides), and magnetic nanocomposites in the adsorption of agrochemicals from water was critically reviewed. Firstly, the adsorbents were characterized from the structural, textural, and physico-chemical points of view. Secondly, the fundamental aspects of the adsorption of various agrochemicals on the solids (dependence on pH, kinetics, and isotherm of adsorption) were studied and interpreted on the basis of the adsorbent features. Thirdly, iterative processes of agrochemical removal from water by adsorption on the reported solids were described. In particular, in some cases the residual concentration of agrochemicals in water was lower than the maximum concentration of agrochemicals that the Italian regulations allow to be released in wastewater, surface waters, or sink water.
Layout Optimization Process to Minimize the Cost of Energy of an Offshore Floating Hybrid Wind−Wave Farm
Jorge Izquierdo-Pérez, Bruno M. Brentan, Joaquín Izquierdo, Niels-Erik Clausen, Antonio Pegalajar-Jurado, Nis Ebsen
March 12, 2020 (v1)
Keywords: farm layout, floating offshore energy generation, hybrid wind-wave platform, LCOE, Optimization, Particle Swarm Optimization, PSO, sustainable energy generation
Offshore floating hybrid wind and wave energy is a young technology yet to be scaled up. A way to reduce the total costs of the energy production process in order to ensure competitiveness in the sustainable energy market is to maximize the farm’s efficiency. To do so, an energy generation and costs calculation model was developed with the objective of minimizing the technology’s Levelized Cost of Energy (LCOE) of the P80 hybrid wind-wave concept, designed by the company Floating Power Plant A/S. A Particle Swarm Optimization (PSO) algorithm was then implemented on top of other technical and decision-making processes, taking as decision variables the layout, the offshore substation position, and the export cable choice. The process was applied off the west coast of Ireland in a site of interest for the company, and after a quantitative and qualitative optimization process, a minimized LCOE was obtained. It was then found that lower costs of ~73% can be reached in the short-term, and th... [more]
Antiproliferative, Antimicrobial, and Antifungal Activities of Polyphenol Extracts from Ferocactus Species
Hosam O. Elansary, Agnieszka Szopa, Marta Klimek-Szczykutowicz, Halina Ekiert, Ahmed A. Barakat, Fahed A. Al-Mana
March 12, 2020 (v1)
Subject: Biosystems
Keywords: antibacterial, anticancer, antifungal, cytotoxicity, Ferocactus, polyphenols, stem extract
Polyphenols, obtained from natural resources, may possess important pharmacological effects. The polyphenolic profiles of the stem extracts of six Ferocactus species (sp.): F. gracilis, F. pottsii, F. herrerae, F. horridus, F. glaucescens, and F. emoryi, were measured using high-performance liquid chromatography (HPLC) with diode-array detection (DAD). Additionally, anticancer, antibacterial, and antifungal activities were examined. Results showed the presence of high to moderate amounts of polyphenols in the extracts (phenolic acids: Protocatechuic acid, 3,4-dihydroxyphenylacetic acid, caffeic acid, and vanillic acid; flavonoids: Rutoside and quercitrin). The highest amounts of 3,4-dihydroxyphenylacetic acid were found in F. glaucescens ((132.09 mg 100 g−1 dry weight (DW)), F. pottsii (75.71 mg 100 g−1 DW), and F. emoryi (69.14 mg 100 g−1 DW) while rutoside content was highest in F. glaucescens (107.66 mg 100 g−1 DW). Maximum antiproliferative activities were observed against HeLa and... [more]
Self-Synchronized Oscillatory Metabolism of Clostridium pasteurianum in Continuous Culture
Erin E Johnson, Lars Rehmann
March 12, 2020 (v1)
Subject: Biosystems
Keywords: Butanol, Clostridium, CSTR, glycerol, metabolism, oscillatory, pasteurianum, redox, synchronized
By monitoring the real-time gas production (CO2 and H2) and redox potential at high sampling frequency in continuous culture of Clostridium pasteurianum on glycerol as sole carbohydrate, the self-synchronized oscillatory metabolism was revealed and studied. The oscillations in CO2 and H2 production were in sync with each other and with both redox potential and glycerol in the continuous stirred tank reactor (CSTR). There is strong evidence that the mechanism for this is in the regulation of the oxidative pathway of glycerol metabolism, including glycolysis, and points toward complex, concerted cycles of enzyme inhibition and activation by pathway intermediates and/or redox equivalents. The importance of understanding such an “oscillatory metabolism” is for developing a stable and highly productive industrial fermentation process for butanol production, as unstable oscillations are unproductive. It is shown that the oscillatory metabolism can be eradicated and reinstated and that the pe... [more]
CFD-Based Study of Nozzle Section Geometry Effects on the Performance of an Annular Multi-Nozzle Jet Pump
Kai Xu, Gang Wang, Liquan Wang, Feihong Yun, Wenhao Sun, Xiangyu Wang, Xi Chen
March 12, 2020 (v1)
Keywords: annular multi-nozzle jet pump, numerical calculation, spanwise vortex, streamwise vortex
CFD simulation and analysis of the internal flow field of the annular multi-nozzle jet pump are carried out to study the effects of nozzle section geometries on performance of the pump based on the finite volume method and realizable k-ε model. The results show that the square nozzle peak efficiency is 3% higher than that of the circular nozzle and 4.1% higher than that of the triangular nozzle. According to the simulation results, the mixing mechanism of the working fluid and second fluid is analyzed on the basis of the vortex dynamics. The results show the following: the recirculation area and the friction loss of the non-circular nozzle are reduced, and the mixing effect is improved; the streamwise vortex plays a major role in the mixing process and decays to an extremely small value at the end of the throat after attenuating rapidly in the suction chamber; compared with the streamwise vortex, the strength of the spanwise vortex is relatively stronger; the spanwise vortex still fluc... [more]
The Impact of Local Hydrodynamics on High-Rate Activated Sludge Flocculation in Laboratory and Full-Scale Reactors
Sophie Balemans, Siegfried E. Vlaeminck, Elena Torfs, Leonie Hartog, Laura Zaharova, Usman Rehman, Ingmar Nopens
March 12, 2020 (v1)
Keywords: Computational Fluid Dynamics, flocculation state, jar test, sludge settling, water resource recovery facility
High rate activated sludge (HRAS) processes have a high potential for carbon and energy recovery from sewage, yet they suffer frequently from poor settleability due to flocculation issues. The process of flocculation is generally optimized using jar tests. However, detailed jar hydrodynamics are often unknown, and average quantities are used, which can significantly differ from the local conditions. The presented work combined experimental and numerical data to investigate the impact of local hydrodynamics on HRAS flocculation for two different jar test configurations (i.e., radial vs. axial impellers at different impeller velocities) and compared the hydrodynamics in these jar tests to those in a representative section of a full scale reactor using computational fluid dynamics (CFD). The analysis showed that the flocculation performance was highly influenced by the impeller type and its speed. The axial impeller appeared to be more appropriate for floc formation over a range of impell... [more]
Prickly Pear Seed Oil by Shelf-Grown Cactus Fruits: Waste or Maste?
Vassilios K. Karabagias, Ioannis K. Karabagias, Ilias Gatzias, Anastasia V. Badeka
March 12, 2020 (v1)
Subject: Materials
Keywords: antioxidant activity, FAs, phenolics, PPSO, volatiles
The chemical composition and properties of seed oils have attracted researchers nowadays. By this meaning, the physicochemical and bioactivity profile of prickly pear seed oil (PPSO) (a product of prickly pear fruits waste) were investigated. Seeds of shelf-grown cactus fruits (Opuntia ficus indica L.) were subjected to analysis. Moisture content (gravimetric analysis), seed content (gravimetric analysis), oil yield (Soxhlet extraction/gravimetric analysis), volatile compounds (HS-SPME/GC-MS), fatty acids profile (GC-FID), in vitro antioxidant activity (DPPH assay), and total phenolic content (Folin-Cioacalteu assay) were determined. Results showed that prickly pear seeds had a moisture content of 6.0 ± 0.1 g/100 g, whereas the oil yield ranged between 5.4 ± 0.5 g/100 g. Furthermore, the PPSO had a rich aroma because of acids, alcohols, aldehydes, esters, hydrocarbons, ketones, and other compounds, with the major volatiles being 2-propenal, acetic acid, pentanal, 1-pentanol, hexanal, 2... [more]
H2S Removal with Sorbent Obtained from Sewage Sludges
Davide Papurello, Andrea Lanzini, Maurizio Bressan, Massimo Santarelli
March 12, 2020 (v1)
Keywords: biogas, H2S removal, sewage sludge, solid sorbent production
Biochar obtained from sewage sludges are adopted for biogas cleaning. Sewage sludges are treated considering temperature, dwell time, activating agent, heating, and flow rate. The best performances achieved are registered considering the char produced at 400 °C using CO2 as an activating agent with a dwell time of 2 h. The adsorption capacity for the biogas cleaning CH4/CO2/H2S (20 ppm(v)) increased from 1.3 mg/g to 5.9 mg/g with the bed height. Future research with chemical activation processes will be made to improve the adsorption capacity achieved to produce cheaper sorbents than commercial ones.
Curcumin Prevents Cyclophosphamide-Induced Lung Injury in Rats by Suppressing Oxidative Stress and Apoptosis
Sultan A. M. Saghir, Sulaiman A. Alharbi, Maged A. Al-Garadi, Naif Al-Gabri, Hagar Y. Rady, Nouran K. Olama, Mahfoudh A. M. Abdulghani, Amir M. Al Hroob, Amer A. Almaiman, May Bin-Jumah, Ayman M. Mahmoud, Medhat Taha
March 12, 2020 (v1)
Subject: Biosystems
Keywords: antioxidant, apoptosis, curcumin, cyclophosphamide, protein carbonyl, pulmonary injury
Curcumin (CUR) has been used since ancient times to treat several ailments as it possesses many pharmacological activities. This study intended to explore the mechanism underlying the protective effects of CUR in remodeling oxidative stress and apoptotic signals in cyclophosphamide (CP)-induced pulmonary injury in albino rats. CUR was administered at a dose of 300 mg/kg/day for 7 days and on the seventh day a single dose of CP (200 mg/kg) was given. Histopathological and ultrastructural examinations of CP-intoxicated rats showed complete alveolar obstruction, thickened inter-alveolar septa, enlarged blood vessels, severe inflammatory edema with pyknotic nuclei, and disappearance of cytoplasmic organelles. Significant increases in caspase-3, malondialdehyde (MDA), and protein carbonyl (PCO) and significant decreases in superoxide dismutase (SOD) and glutathione peroxidase (GPx) were observed. In contrast, rats that received CUR showed clear and empty lumina with single row of pneumocyte... [more]
Community-Based Link-Addition Strategies for Mitigating Cascading Failures in Modern Power Systems
Po Hu, Lily Lee
March 12, 2020 (v1)
Keywords: cascading failures, complex network theory, Fast–Newman algorithm, link-addition strategy, power systems
The propagation of cascading failures of modern power systems is mainly constrained by the network topology and system parameter. In order to alleviate the cascading failure impacts, it is necessary to adjust the original network topology considering the geographical factors, construction costs and requirements of engineering practice. Based on the complex network theory, the power system is modeled as a directed graph. The graph is divided into communities based on the Fast−Newman algorithm, where each community contains at least one generator node. Combined with the islanding characteristics and the node vulnerability, three low-degree-node-based link-addition strategies are proposed to optimize the original topology. A new evaluation index combining with the attack difficulty and the island ratio is proposed to measure the impacts on the network under sequential attacks. From the analysis of the experimental results of three attack scenarios, this study adopts the proposed strategie... [more]
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