Records Added in 2019
Records added in 2019
Change year: 2018 | 2019
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Showing records 1 to 25 of 528. [First] Page: 1 2 3 4 5 Last
Pilot Plant Data Assessment in Anaerobic Digestion of Organic Fraction of Municipal Waste Solids
Massimo Migliori, Enrico Catizzone, Girolamo Giordano, Adolfo Le Pera, Miriam Sellaro, Alessandro Lista, Giuseppe Zanardi, Luciano Zoia
April 15, 2019 (v1)
Subject: Biosystems
Keywords: biogas, dry anaerobic digestion, municipal waste, wet anaerobic digestion
In this paper, a preliminary study of anaerobic digestion of organic fraction of municipal solid wastes (OFMSW) in presented with the aim to compare the performances of both wet- and dry-type reactors. The treatment of OFMSW via anaerobic digestion (AD) producing biogas is a process that is receiving a growing interest because two different needs can be coupled: the request of sustainable municipal waste treatments and increasing demand renewable energy. This paper aims to offer experimental results comparing batch test and continuous experimental reactors under different conditions of humidity and solid content. Results show that both the investigated configurations may be used for converting OFMSW into a high quality biogas and that the increase of dry matter in the continuous process still allows to achieve significant biogas production rates. A slight reduction of the methane content was observed (less than 5% relative) that can be also related to the change in the level of volatil... [more]
Analysis of Influencing Factors of Occupational Safety and Health in Coal Chemical Enterprises Based on the Analytic Network Process and System Dynamics
Kai Yu, Lujie Zhou, Chen Hu, Linlin Wang, Weiqiang Jin
April 15, 2019 (v1)
Subject: Energy Policy
Keywords: analytic network process, management and control measures, occupational safety and health, Simulation, system dynamics
In the production process of coal chemical enterprises, there are factors such as dust, poisons, as well as toxic and harmful gases, which seriously restrict the safety and health of employees. It is urgent to strengthen research on occupational safety and health (OSH) of coal chemical enterprises. Research on the influencing factors is very important to improve the level of OSH in coal chemical enterprises. Therefore, this paper analyzed the factors affecting OSH of coal chemical enterprises from four aspects: “human⁻machine⁻environment⁻management„. Then, an influencing factor indicator system was constructed. The weights of the indicator were analyzed using the Analytic Network Process (ANP). On this basis, the primary and secondary indicators of the influencing factors were ranked. Subsequently, the weights of ANP were taken as the influence coefficient between variables, and the System Dynamics (SD) model of OSH control measures was established and analyzed. According to the weight... [more]
Component Characterization in a Growth-Dependent Physiological Context: Optimal Experimental Design
Nathan Braniff, Matthew Scott, Brian Ingalls
April 15, 2019 (v1)
Keywords: cell physiology, characterization, host-context effects, model fitting, optimal control, optimal experimental design, synthetic biology
Synthetic biology design challenges have driven the use of mathematical models to characterize genetic components and to explore complex design spaces. Traditional approaches to characterization have largely ignored the effect of strain and growth conditions on the dynamics of synthetic genetic circuits, and have thus confounded intrinsic features of the circuit components with cell-level context effects. We present a model that distinguishes an activated gene’s intrinsic kinetics from its physiological context. We then demonstrate an optimal experimental design approach to identify dynamic induction experiments for efficient estimation of the component’s intrinsic parameters. Maximally informative experiments are chosen by formulating the design as an optimal control problem; direct multiple-shooting is used to identify the optimum. Our numerical results suggest that the intrinsic parameters of a genetic component can be more accurately estimated using optimal experimental designs, an... [more]
Approaches to Suppress CO₂-Induced Plasticization of Polyimide Membranes in Gas Separation Applications
Moli Zhang, Liming Deng, Dongxiao Xiang, Bing Cao, Seyed Saeid Hosseini, Pei Li
April 15, 2019 (v1)
Keywords: Carbon Dioxide, gas separation, membrane, plasticization, polyimide
Polyimides with excellent physicochemical properties have aroused a great deal of interest as gas separation membranes; however, the severe performance decay due to CO₂-induced plasticization remains a challenge. Fortunately, in recent years, advanced plasticization-resistant membranes of great commercial and environmental relevance have been developed. In this review, we investigate the mechanism of plasticization due to CO₂ permeation, introduce effective methods to suppress CO₂-induced plasticization, propose evaluation criteria to assess the reduced plasticization performance, and clarify typical methods used for designing anti-plasticization membranes.
Model-Based Cost Optimization of Double-Effect Water-Lithium Bromide Absorption Refrigeration Systems
Sergio F. Mussati, Seyed Soheil Mansouri, Krist V. Gernaey, Tatiana Morosuk, Miguel C. Mussati
April 15, 2019 (v1)
Keywords: absorption refrigeration, cost optimization, double-effect system, H2O-LiBr working pair, nonlinear mathematical programming
This work presents optimization results obtained for a double-effect H₂O-LiBr absorption refrigeration system considering the total cost as minimization criterion, for a wide range of cooling capacity values. As a model result, the sizes of the process units and the corresponding operating conditions are obtained simultaneously. In this paper, the effectiveness factor of each proposed heat exchanger is considered as a model optimization variable which allows (if beneficial, according to the objective function to be minimized) its deletion from the optimal solution, therefore, helping us to determine the optimal configuration. Several optimization cases considering different target levels of cooling capacity are solved. Among the major results, it was observed that the total cost is considerably reduced when the solution heat exchanger operating at low temperature is deleted compared to the configuration that includes it. Also, it was found that the effect of removing this heat exchange... [more]
Processes of Cracking and Crushing in Hybrid Fibre Reinforced High-Performance Concrete Slabs
Piotr Smarzewski
April 15, 2019 (v1)
Subject: Materials
Keywords: high-performance concrete, non-contact deformation measurements, polypropylene fibres, reinforcement, slab, steel fibres
This paper presents the experimental results obtained with the non-contact three-dimensional deformation measuring system⁻ARAMIS and finite element analysis performed using ANSYS of three slabs made of high-performance concrete (HPC) and hybrid (steel/ST and polypropylene/PP) fibre reinforced high-performance concrete (FRHPC). The research was performed on reinforced concrete (RC) slabs with a web mesh of ϕ8 mm bars. All the slabs had an identical amount of steel bars and differed by the fibre volume content. The main objective of the research was to determine the impact of adding polypropylene and steel fibres on the carrying capacity and ductility of HPC slabs. Analysis of the results was conducted based on load⁻deflection curves, crack distribution, vertical displacements and strains. The research findings indicate that fibres may improve peak strength. The presence of PP and ST hybrid fibres in HPC restricted the propagation of cracks. The energy absorption capacity as well as the... [more]
Employment of Emergency Advanced Nurses of Turkey: A Discrete-Event Simulation Application
Abdulkadir Atalan, Cem Cagri Donmez
April 15, 2019 (v1)
Keywords: advanced nurses, discrete event simulation, emergency service resources, emergency services
In the present study, problems in emergency services (ESs) were dealt with by analyzing the working system of ESs in Turkey. The purpose of this study was to reduce the waiting times spent in hospitals by employing advanced nurses (ANs) to treat patients who are not urgent, or who may be treated as outpatients in ESs. By applying discrete-event simulation on a 1/24 (daily) and 7/24 (weekly) basis, and by employing ANs, it was determined that the number of patients that were treated increased by 26.71% on a 1/24 basis, and by 15.13% on a 7/24 basis. The waiting time that was spent from the admission to the ES until the treatment time decreased by 38.67% on a 1/24 basis and 53.66% on a 24/7 basis. Similarly, the length of stay was reduced from 82.46 min to 53.97 min in the ES. Among the findings, it was observed that the efficiency rate of the resources was balanced by the employment of ANs, although it was not possible to obtain sufficient efficiency from the resources used in the ESs p... [more]
Study on the Preparation and Hydration Properties of a New Cementitious Material for Tailings Discharge
Yunbing Hou, Pengchu Ding, Dong Han, Xing Zhang, Shuxiong Cao
April 15, 2019 (v1)
Subject: Materials
Keywords: cement-based paste discharge, mechanical behaviors, MIP, new cementitious material, SEM, TG/DTG, XRD
Blast furnace slag (BFS) is often used as a cement-based raw material for underground filling and surface cemented paste discharge of tailings during mining processes. This paper studied a new cement-based material (NCM) with BFS to replace ordinary Portland cement (OPC). A uniaxial compressive strength (UCS) experiment was used to test the mechanical strength of samples; X-ray diffraction and thermal gravity experiments were used to test the crystalline phases and amount of hydration products by samples; a scanning electron microscope experiment was used to observe the influence of the hydration products morphology by samples; mercury intrusion porosimetry experiment was used to analyze the pore size distribution of samples. The samples with NCM had an optimum UCS; the crystalline phases of the hydration products were similar in OPC and NCM. However, the amount of product formed in OPC was less than that in NCM at the same curing time; more ettringite and calcium silicate hydrate were... [more]
Simulating the Filtration Effects of Cement-Grout in Fractured Porous Media with the 3D Unified Pipe-Network Method
Zizheng Sun, Xiao Yan, Weiqi Han, Guowei Ma, Yiming Zhang
April 15, 2019 (v1)
Subject: Other
Keywords: filtration effects, fractured porous medium, grout penetration, two-phase flow, unified pipe-network method
In grouting process, filtration is the retention and adsorption of cement-grout particles in a porous/fractured medium. Filtration partly/even completely blocks the transportation channels in the medium, greatly decreasing its permeability. Taking into account filtration effects is essential for accurately estimating the grout penetration region. In this paper, the 3D unified pipe-network method (UPM) is adopted for simulating 3D grout penetration process in a fractured porous medium, considering filtration effects. The grout is assumed to exhibit two-phase flow, and the filtration effects depend on not only the concentration and rheology of the grout but also the porosity and permeability of the fractured porous medium. By comparing the model with the experimental results, we firstly verify the proposed numerical model. Then sensitivity analysis is conducted, showing the influences of grout injection pressures, the water⁻cement ratios of grout (W/C) and the grout injection rates on fi... [more]
Characterization, Expression Profiling, and Functional Analyses of a 4CL-Like Gene of Populus trichocarpa
Hui Wei, Chen Xu, Ali Movahedi, Weibo Sun, Qiang Zhuge
April 15, 2019 (v1)
Subject: Biosystems
Keywords: 4CL-like, ACS, box I domain, box II domain, CL, Populus trichocarpa, PTS
Adenosine 5′-monophosphate (AMP) (adenylate)-forming acetyl-CoA synthetase (ACS) catalyzes the formation of acetyl-coenzyme A (CoA), and the ACS family is closely related to the 4-coumarate CoA ligase (4CL) family. In this study, a 4CL-like gene was cloned from Populus trichocarpa and named Pt4CL-like. Characterization of Pt4CL-like, using bioinformatics, showed that it contained box I and box II domains at the end of the C-terminal sequence, and there is a characteristic sequence of ACS, namely, peroxisome-targeting sequence (PTS). Real-time PCR results showed that the 4CL-like gene was expressed in all tissues tested, and was highly expressed in the stems. A denaturation and renaturation process was conducted, and the recombinant Pt4CL-like protein was purified through HisTrapTM high performance affinity chromatography. It showed Pt4CL-like protein did not catalyze substrates of 4CL, but could significantly catalyzed sodium acetate. These results indicate that Pt4CL-like protein belo... [more]
Adsorption of Organic Constituents from Reverse Osmosis Concentrate in Coal Chemical Industry by Coking Coal
Hongxiang Xu, Qizheng Qin, Changfeng Zhang, Kejia Ning, Rong Zhao, Penghui Wang, Jiushuai Deng, Gen Huang
April 15, 2019 (v1)
Keywords: Adsorption, adsorption mechanism, aromatic structure, kinetics
To solve the unwieldy problem of coal chemical wastewater reverse osmosis concentrate (ROC), a novel treatment method in which coking coal was used to adsorb the organic from ROC and the adsorption mechanism involved was investigated. The results showed that the organic components in the ROC of coal chemical industry can be effectively absorbed by the coking coal and the total organic carbon, UV254 and chromaticity of treated ROC reduced by 70.18%, 70.15% and 59.55%, respectively, at the coking coal dosage of 80 g/L. The isothermal adsorption data were fitted to the Langmuir model well. The kinetics were expressed well by the quasi-second-order kinetic model. The intragranular diffusion model and the BET (Acronym for three scientists: Brunauer⁻Emmett⁻Teller) test showed that the adsorption occurred mainly on the surface of the coking coal and its macropores and mesopores. When the pollutants further diffused to the mesopores and micropores, the adsorption rate decreased. The result of... [more]
Application of Supergravity Technology in a TEG Dehydration Process for Offshore Platforms
Hongfang Lu, Guoguang Ma, Mohammadamin Azimi, Lingdi Fu
April 15, 2019 (v1)
Keywords: Higee, natural gas dehydration, supergravity technology, TEG
In the dehydration process of offshore natural gas production, due to the site limitation of the platform, if the conventional triethylene glycol (TEG) dehydration process is employed, the size of the absorption tower is usually small. However, in the case of fluctuations in raw material gas and large gas production, it is easy to cause a large loss of TEG and a flooding event, resulting in the water dew point of natural gas not meeting the requirements. Therefore, combined with the dehydration process of TEG and supergravity technology, a new dehydration process of natural gas suitable for offshore platforms is proposed in this paper. The principle and process of the TEG dehydration process based on supergravity technology are discussed by establishing a mass transfer model. The laboratory experiment of the new process is carried out, and the effects of TEG flow rate, super-gravity packed bed rotation speed, and gas flow rate on the air dew point are obtained. By studying the dewateri... [more]
Optimization of the Melting Performance of a Thermal Energy Storage Unit with Fractal Net Fins
Jiayi Zheng, Cheng Yu, Taotao Chen, Yanshun Yu, Fang Wang
April 15, 2019 (v1)
Keywords: fin, fractal, melting, net, phase change
In this study, fractal net fins were introduced to improve the melting performance of a thermal energy storage unit. A transient model for melting heat transfer for phase change material (PCM) was presented and numerically analyzed, to study the melting performance in a thermal energy storage unit using fractal net fins. The melting phase change process was modelled using the apparent heat capacity method. The evolutions of temperature and the liquid fraction in the thermal energy storage unit were investigated and discussed. The effects of the length and width ratios of the fractal net on melting performance were analyzed to obtain the optimal fin configuration. The results indicated that the fractal net fins significantly enhanced the melting heat transfer performance of the PCM in a thermal energy storage unit. The fractal net fins configuration was optimal when the length and width ratios of the fractal net were 0.5. The temperature response at the corner points of the fractal net... [more]
Efficient Removal of Hexavalent Chromium from Wastewater with Electro-Reduction
Hao Peng, Yumeng Leng, Qinzhe Cheng, Qian Shang, Jiancheng Shu, Jing Guo
April 15, 2019 (v1)
Keywords: acidic medium, chromium, electro-reduction
Removal of hexavalent chromium had attracted much attention as it is a hazardous contaminant. An electrocoagulation-like technology electro-reduction was applied. The chromium (VI) in the wastewater was reduced to chromium (III) by the electron supplied by electricity power and Fe2+, formed from corrosion of steel electrodes in acidic conditions. The mechanism and parameters affecting the reaction were investigated. The results optimized by response surface methodology indicated that the influence of single factor on the reduction efficiency followed the order: A: dosage of H₂SO₄ > C: reaction time > D: reaction temperature > B: current intensity. The reduction efficiency was hardly affected by current intensity, while it was increased with the increasing of reaction time and acid concentration. The reducing agent, Fe2+ an and extra free electron, acted as a reducing agent and could easily reduce hexavalent chromium to trivalent chromium at high temperatures in an acidic medium.
Effective Dye Degradation by Graphene Oxide Supported Manganese Oxide
Hayarpi Saroyan, George Z. Kyzas, Eleni A. Deliyanni
April 15, 2019 (v1)
Keywords: characterization, degradation, dyes, graphene oxide, manganese oxide, reuse
Graphene oxide (GO) was used as a support for manganese oxide (MnO₂) for the preparation of a nanocomposite catalyst for the degradation of an azo dye, Reactive Black 5 (RB5). The nanocomposite was characterized for the structure by XRD, for the morphology with SEM, and for the surface chemistry with FTIR and potentiometric titration measurements. The GO-MnO₂ nanocomposite presented a high catalytic activity for the degradation/oxidation of RB5 at ambient conditions, which was higher than that of the pure MnO₂ and could be attributed to the beneficial contribution of the manganese oxide and the graphene oxide.
Catastrophic Health Expenditures and Its Inequality in Households with Cancer Patients: A Panel Study
Munjae Lee, Kichan Yoon
April 15, 2019 (v1)
Subject: Biosystems
Keywords: cancer patient households, catastrophic health expenditure, healthcare spending, Korea Health Panel, panel logit analysis
This study aims to examine the determinants of catastrophic health expenditure in households with cancer patients by conducting a panel analysis of three-year data. Data are adopted from surveys administered by Korea Health Panel for 2012⁻2014. We conducted correspondence and conditional transition probability analyses to examine households that incurred catastrophic health expenditure, followed by a panel logit analysis. The analyses reveal three notable results. First, the occurrence of catastrophic health expenditure differs by age group, that is, the probability of incurring catastrophic health expenditure increases with age. Second, this probability is higher in households with National Health Insurance than those receiving medical care benefits. Finally, households without private health insurance report a higher occurrence rate. The findings suggest that elderly people with cancer have greater medical coverage and healthcare needs. Private health insurance contributes toward pro... [more]
Model-Based Stochastic Fault Detection and Diagnosis of Lithium-Ion Batteries
Jeongeun Son, Yuncheng Du
April 15, 2019 (v1)
Keywords: fault detection and classification, lithium-ion battery, Optimization, polynomial chaos expansion, thermal management, uncertainty analysis
The Lithium-ion battery (Li-ion) has become the dominant energy storage solution in many applications, such as hybrid electric and electric vehicles, due to its higher energy density and longer life cycle. For these applications, the battery should perform reliably and pose no safety threats. However, the performance of Li-ion batteries can be affected by abnormal thermal behaviors, defined as faults. It is essential to develop a reliable thermal management system to accurately predict and monitor thermal behavior of a Li-ion battery. Using the first-principle models of batteries, this work presents a stochastic fault detection and diagnosis (FDD) algorithm to identify two particular faults in Li-ion battery cells, using easily measured quantities such as temperatures. In addition, models used for FDD are typically derived from the underlying physical phenomena. To make a model tractable and useful, it is common to make simplifications during the development of the model, which may con... [more]
Multiscale Agent-Based and Hybrid Modeling of the Tumor Immune Microenvironment
Kerri-Ann Norton, Chang Gong, Samira Jamalian, Aleksander S. Popel
April 15, 2019 (v1)
Subject: Biosystems
Keywords: computational biology, immune checkpoint inhibitor, immuno-oncology, immunotherapy, mathematical modeling, multiscale systems biology, quantitative systems pharmacology (QSP)
Multiscale systems biology and systems pharmacology are powerful methodologies that are playing increasingly important roles in understanding the fundamental mechanisms of biological phenomena and in clinical applications. In this review, we summarize the state of the art in the applications of agent-based models (ABM) and hybrid modeling to the tumor immune microenvironment and cancer immune response, including immunotherapy. Heterogeneity is a hallmark of cancer; tumor heterogeneity at the molecular, cellular, and tissue scales is a major determinant of metastasis, drug resistance, and low response rate to molecular targeted therapies and immunotherapies. Agent-based modeling is an effective methodology to obtain and understand quantitative characteristics of these processes and to propose clinical solutions aimed at overcoming the current obstacles in cancer treatment. We review models focusing on intra-tumor heterogeneity, particularly on interactions between cancer cells and strom... [more]
Revolution 4.0: Industry vs. Agriculture in a Future Development for SMEs
Ilaria Zambon, Massimo Cecchini, Gianluca Egidi, Maria Grazia Saporito, Andrea Colantoni
April 15, 2019 (v1)
Subject: Energy Policy
Keywords: agriculture 4.0, application research, Industry 4.0, open source, SMEs, Supply Chain
The present review retraces the steps of the industrial and agriculture revolution that have taken place up to the present day, giving ideas and considerations for the future. This paper analyses the specific challenges facing agriculture along the farming supply chain to permit the operative implementation of Industry 4.0 guidelines. The subsequent scientific value is an investigation of how Industry 4.0 approaches can be improved and be pertinent to the agricultural sector. However, industry is progressing at a much faster rate than agriculture. In fact, already today experts talk about Industry 5.0. On the other hand, the 4.0 revolution in agriculture is still limited to a few innovative firms. For this reason, this work deals with how technological development affects different sectors (industry and agriculture) in different ways. In this innovative background, despite the advantages of industry or agriculture 4.0 for large enterprises, small- and medium-sized enterprises (SMEs) of... [more]
The Effect of the Presence of Very Cohesive Geldart C Ultra-Fine Particles on the Fluidization of Geldart A Fine Particle Beds
Abbas Kamranian Marnani, Andreas Bück, Sergiy Antonyuk, Berend van Wachem, Dominique Thévenin, Jürgen Tomas
April 15, 2019 (v1)
Subject: Materials
Keywords: agglomeration, binary mixtures, cohesion, fine particle, fluidization, ultra-fine powders
The effect of the presence of ultra-fines (d < 10 μm) on the fluidization of a bed containing fine particles (d < 100 μm), is the subject of this paper. Practically, it can happen due to breakage or surface abrasion of the fine particles in some processes which totally changes the size distribution and also fluidization behaviour. The materials used in this study are both ground calcium carbonate (GCC); fine is CALCIT MVT 100 (Geldart’s group A) and ultra-fine is CALCIT MX 10 (group C). The experimental results for different binary mixtures of these materials (ultra-fines have 30%, 50%, or 68% of the total mixture weight) show that the physical properties of the mixtures are close to those of pure ultra-fine powders. Using mean values of the bed pressure drop calculated from several independent repetitions, the fluidization behaviour of different mixtures are compared and discussed. The fluidization behaviour of the mixtures is non-reproducible and includes cracking, channelling... [more]
Textile Wastewater Treatment for Water Reuse: A Case Study
Hua Yin, Peiwen Qiu, Yuange Qian, Zhuwen Kong, Xiaolong Zheng, Zhihua Tang, Huafang Guo
April 15, 2019 (v1)
Keywords: ozonation, reverse osmosis, textile wastewater, ultrafiltration, water recovery rate, water reuse
The reduced natural waters and the large amount of wastewater produced by textile industry necessitate an effective water reuse treatment. In this study, a combined two-stage water reuse treatment was established to enhance the quality and recovery rate of reused water. The primary treatment incorporated a flocculation and sedimentation system, two sand filtration units, an ozonation unit, an ultrafiltration (UF) system, and a reverse osmosis (RO) system. The second treatment included an ozonation unit, a sand filtration unit, and UF and RO systems. The color removal rate increased with the increasing ozone dosage, and the relational expression between the ozone dosage and color removal rate was fitted. Ozonation greatly reduced the color by 92.59 and 97.27 times during the primary and second ozonation stages, respectively. RO had the highest removal rate. The combined processes showed good performance in water reuse treatment. The treated, reused water satisfied the reuse standard and... [more]
Mixing Efficiency Analysis on Droplet Formation Process in Microchannels by Numerical Methods
Jin-yuan Qian, Xiao-juan Li, Zhi-xin Gao, Zhi-jiang Jin
April 15, 2019 (v1)
Keywords: disperse phase fraction, junction configuration, mixing efficiency, VOF method
Liquid⁻liquid two-phase flow in microchannels has attracted much attention, due to the superiority of mass transfer enhancement. One of the biggest unresolved challenges is the low mixing efficiency at the microscale. Suitable mixing efficiency is important to promote the mass transfer of two-phase flow in microchannels. In this paper, the mixing efficiency in three junction configurations, including a cross-shaped junction, a cross-shaped T-junction, and a T-junction, is investigated by the volume of fluid (VOF) method coupled with user-defined scalar (UDS) model. All three junction configurations are designed with the same hydraulic diameter of 100 μm. Mixing components are distributed in the front and back parts of the droplet. The mixing efficiency in the droplet forming stage and the droplet moving stage are compared quantitatively. Results show that different junction configurations create very different mixing efficiencies, and the cross-shaped T-junction performs best, with rel... [more]
Acknowledgement to Reviewers of Processes in 2018
Processes Editorial Office
April 15, 2019 (v1)
Subject: Other
Rigorous peer-review is the corner-stone of high-quality academic publishing [...]
Multi-Tubular Reactor for Hydrogen Production: CFD Thermal Design and Experimental Testing
Elvira Tapia, Aurelio González-Pardo, Alfredo Iranzo, Manuel Romero, José González-Aguilar, Alfonso Vidal, Mariana Martín-Betancourt, Felipe Rosa
April 15, 2019 (v1)
Keywords: Computational Fluid Dynamics, Computational Fluid Dynamics, hydrogen production, model, solar reactor, solar receiver, thermal energy
This study presents the Computational Fluid Dynamics (CFD) thermal design and experimental tests results for a multi-tubular solar reactor for hydrogen production based on the ferrite thermochemical cycle in a pilot plant in the Plataforma Solar de Almería (PSA). The methodology followed for the solar reactor design is described, as well as the experimental tests carried out during the testing campaign and characterization of the reactor. The CFD model developed for the thermal design of the solar reactor has been validated against the experimental measurements, with a temperature error ranging from 1% to around 10% depending on the location within the reactor. The thermal balance in the reactor (cavity and tubes) has been also solved by the CFD model, showing a 7.9% thermal efficiency of the reactor. CFD results also show the percentage of reacting media inside the tubes which achieve the required temperature for the endothermic reaction process, with 90% of the ferrite pellets inside... [more]
Ultrasonic-Assisted Extraction and Swarm Intelligence for Calculating Optimum Values of Obtaining Boric Acid from Tincal Mineral
Bahdisen Gezer, Utku Kose
April 15, 2019 (v1)
Keywords: Artificial Intelligence, boric acid, central composite design, Optimization, swarm intelligence, tincal, ultrasound assisted extraction
The objective of this study is to focus on boric acid extraction from the mineral tincal, in order to determine the optimum conditions thanks to the ultrasonic-assisted extraction (UAE) technique (with the response surface methodology (RSM) for the first time), and artificial intelligence based swarm intelligence. Characterization of the tincal were done by using thermo-gravimetric assay (TG-DTA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analyses. In detail, a central composite design (CCD) was used for determining the effects of different solvent/solid ratios, pH, extraction time, and extraction temperature on the yield, which was determined by the conductometric method. The optimum values regarding the best extraction process was calculated by using five different swarm intelligence techniques: Particle swarm optimization (PSO), cuckoo search (CS), genetic algorithms (GA), Differential evolution (DE), and the vortex optimization algorithm (VOA). In... [more]
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