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Showing records 776 to 800 of 1263. [First] Page: 28 29 30 31 32 33 34 35 36 Last
Multi-Objective Optimal Configuration of the CCHP System
Liukang Zheng, Xiaoli Wang, Baochen Jiang
May 22, 2020 (v1)
Keywords: combined cooling, environmental benefits, heating and power (CCHP) system, microgrid, Optimization, particle swarm optimization (PSO), reliability
The combined cooling, heating and power (CCHP) system not only has high energy efficiency but also has different load structures. Traditional separate production (SP) system and power supply system do not consider the land cost in terms of the environmental benefits, and in the aspect of the power supply reliability, the grid-connected inverter cost is also ignored. Considering the deficiency of the traditional energy supply system, this paper builds the CCHP system construction cost model. The particle swarm optimization (PSO) is adopted to find out the minimum value of the construction cost, and the optimal system construction scheme is constructed from three aspects which are system reliability, economic benefits and environmental benefits. In this paper, the typical daily data, as well as the meteorological data and the load data, in the last four years are taken as experimental dataset. The experimental results show that compared with the traditional SP system and power supply sys... [more]
Techno-Economic Analysis of CO2 Capture Technologies in Offshore Natural Gas Field: Implications to Carbon Capture and Storage in Malaysia
Norhasyima Rahmad Sukor, Abd Halim Shamsuddin, Teuku Meurah Indra Mahlia, Md Faudzi Mat Isa
May 22, 2020 (v1)
Keywords: carbon capture and storage (CCS), Carbon Dioxide Capture, offshore gas field, Technoeconomic Analysis
Growing concern on global warming directly related to CO2 emissions is steering the implementation of carbon capture and storage (CCS). With Malaysia having an estimated 37 Tscfd (Trillion standard cubic feet) of natural gas remains undeveloped in CO2 containing natural gas fields, there is a need to assess the viability of CCS implementation. This study performs a techno-economic analysis for CCS at an offshore natural gas field in Malaysia. The framework includes a gas field model, revenue model, and cost model. A techno-economic spreadsheet consisting of Net Present Value (NPV), Payback Period (PBP), and Internal Rate of Return (IRR) is developed over the gas field’s production life of 15 years for four distinctive CO2 capture technologies, which are membrane, chemical absorption, physical absorption, and cryogenics. Results predict that physical absorption solvent (Selexol) as CO2 capture technology is most feasible with IRR of 15% and PBP of 7.94 years. The output from the techno-... [more]
Data-Driven Modelling of the Complex Interaction between Flocculant Properties and Floc Size and Structure
Anita Lourenço, Marco S. Reis, Julien Arnold, Maria Graca Rasteiro
May 22, 2020 (v1)
Keywords: flocculation, laser diffraction spectroscopy, polyelectrolytes, statistical modelling, wastewater treatment
Polymeric flocculants are widely used due to their ability to efficiently promote flocculation at low dosages. However, fundamental background knowledge about how they act and interact with the substrates is often scarce, or insufficient to infer the best chemical configuration for treating a specific effluent. Inductive, data-driven approaches offer a viable solution, enabling the development of effective solutions for each type of effluent, overcoming the knowledge gap. In this work, we present such an inductive workflow that combines the statistical design of experiments and predictive modelling, and demonstrates its effectiveness in the development of anionic polymeric flocculants for the treatment of a real effluent from the potato crisps manufacturing industry. Based on the results presented, it is possible to conclude that the hydrodynamic diameter, charged fraction and concentration are the parameters with a stronger influence on the characteristics of flocs obtained when using... [more]
The Profile of the Foreign Investor in the Romanian Chemical Industry
Iulia Iuga, Aniela Danciu, Imola Drigă
May 22, 2020 (v1)
Keywords: chemical industry, factor analysis, foreign direct investments (FDI), the investor profile
The main aim of this study is to build the investor’s profile in the Romanian chemical industry and to highlight the factors that influenced the decision of investing in Romania rather than other Central Eastern European countries. The data collection was performed in June 2019 and the list of the 150 foreign companies from the chemical industry was obtained from The National Trade Register Office. Data used in this research were collected using a questionnaire. Dependent variable represents the probability of investing in Romania, with the option of the other Central and Eastern European countries as reference group. The main part of our analysis focus on this question: “Which were the reasons that made you decide invest in Romania?” For analysis, a number of six main classes are used: Infrastructure, labor force, Agglomeration factors, Knowledge, Market Size and Cost factors (as independent variables). Main results consist in the presence of three factors with a positive impact. The... [more]
Analysis of the Sieve Unit Inclination Angle in the Cleaning Process of Oat Grain in a Rotary Cleaning Device
Zbigniew Krzysiak, Waldemar Samociuk, Janusz Zarajczyk, Zdzisław Kaliniewicz, Daniel Pieniak, Marcin Bogucki
May 22, 2020 (v1)
Keywords: conical sieve, grain separation, oat grain, rotary cleaning device
The article presents some of the research on the wider work related to testing and improving a new rotary cleaning device. The new cereal grain cleaning and separation device can support the development of sustainable agriculture in terms of seed purity and quality. This device is especially useful for small and medium-sized farms. This device has the characteristics of a multi-stage screen aided by an air stream (i.e., by pneumoseparation). The prototype was constructed at the University of Life Sciences in Lublin. The research was conducted at a test stand, which allowed changes in the operating parameters of the cleaner and their measurement. The scope of the tests included determining the influence of the inclination angle of the sieve unit (α) on the effectiveness and efficiency of oat grain cleaning. The experiment was carried out using two rotational spindle speeds: 5 and 75 rpm. The quality of the separation and cleaning of oat grains was evaluated using six cleaning process pa... [more]
Inverse Tangent Functional Nonlinear Feedback Control and Its Application to Water Tank Level Control
Jian Zhao, Xianku Zhang
May 22, 2020 (v1)
Keywords: inverse tangent function, nonlinear feedback, robust control, water level control
This paper explores the significance and feasibility of addressing a notion that the system error of a nonlinear feedback control can be decorated by an inverse tangent function in order to attain a sound energy-efficient performance. The related mathematical model and relevant evaluation of this concept are further illustrated by demonstrating a case study about the control performance of water tank level. The rationale of robust control and theoretical algorithm of Lyapunov stability theorem are outlined to evaluate the effectiveness of nonlinear feedback with inverse tangent function in terms of improving robustness of PID (Proportional−Integral−Derivative) controller and energy-saving capability. By demonstrating five simulations of different scenarios, it ultimately proves that the modified robust PID controller by inverse tangent function meets the requirement of energy-saving capacity. Comparing with the routine PID control, the mean control input of controlling water tank level... [more]
Optimization Strategies for Dockless Bike Sharing Systems via two Algorithms of Closed Queuing Networks
Rui-Na Fan, Fan-Qi Ma, Quan-Lin Li
May 22, 2020 (v1)
Keywords: closed queuing network, dockless bike sharing system, flow equivalent server algorithm, mean value analysis, optimization strategy, sustainable transportation
The dockless bike sharing system (DBSS) has been globally adopted as a sustainable transportation system. Due to the robustness and tractability of the closed queuing network (CQN), it is a well-behaved method to model DBSSs. In this paper, we view DBSSs as CQNs and use the mean value analysis (MVA) algorithm to calculate a small size DBSS and the flow equivalent server (FES) algorithm to calculate the larger size DBSS. This is the first time that the FES algorithm is used to study the DBSS, by which the CQN can be divided into different subnetworks. A parking region and its downlink roads are viewed as a subnetwork, so the computation of CQN is reduced greatly. Based on the computation results of the two algorithms, we propose two optimization functions for determining the optimal fleet size and repositioning flow, respectively. At last, we provide numerical experiments to verify the two algorithms and illustrate the optimal fleet size and repositioning flow. This computation framewor... [more]
Facile Synthesis of Bio-Template Tubular MCo2O4 (M = Cr, Mn, Ni) Microstructure and Its Electrochemical Performance in Aqueous Electrolyte
Deepa Guragain, Camila Zequine, Ram K Gupta, Sanjay R Mishra
May 22, 2020 (v1)
Subject: Materials
Keywords: bio-template, cyclic voltammetry, electrochemical, MCo2O4 (M = Cr, Mn, Ni), specific capacitance
In this project, we present a comparative study of the electrochemical performance for tubular MCo2O4 (M = Cr, Mn, Ni) microstructures prepared using cotton fiber as a bio-template. Crystal structure, surface properties, morphology, and electrochemical properties of MCo2O4 are characterized using X-ray diffraction (XRD), gas adsorption, scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), cyclic voltammetry (CV), and galvanostatic charge-discharge cycling (GCD). The electrochemical performance of the electrode made up of tubular MCo2O4 structures was evaluated in aqueous 3M KOH electrolytes. The as-obtained templated MCo2O4 microstructures inherit the tubular morphology. The large-surface-area of tubular microstructures leads to a noticeable pseudocapacitive property with the excellent electrochemical performance of NiCo2O4 with specific capacitance value exceeding 407.2 F/g at 2 mV/s scan rate. In addition, a Coulombic efficiency ~100%, and excellent cy... [more]
Effect of Nitrate and Perchlorate on Selenate Reduction in a Sequencing Batch Reactor
Hyun-Woo Kim, Seong Hwan Hong, Hyeoksun Choi
May 22, 2020 (v1)
Keywords: biological selenate reduction, electron donor competition, nitrate, perchlorate, sequencing batch
Selenate removal from a water body is being vigorously debated owing to severe health impact, but inhibitions of coexisting anions have been reported. To suggest a viable treatment option, this study investigates the effect of nitrate and perchlorate on selenate reduction in a laboratory-scale sequencing batch reactor. The experimental design tests how competing electron acceptors (NO3− and ClO4−) and electron donor (acetate) limitations affect selenate reduction in the reactor. Results show that the reactor achieves almost complete selenate reduction within the initial concentration ranges of 0.1−1 mM by enriching selenate-reducing bacteria with appropriate temperature (30 °C) and acclimation period (50 days). We monitored simultaneous selenate and nitrate reduction in the reactor without specific inhibition due to a difference in microbial growth strategy related to electron donor status. Lack of perchlorate-reducing bacteria makes perchlorate addition (0.2 mM) not to be closely asso... [more]
Increased Energy Efficiency of a Backward-Feed Multiple-Effect Evaporator Compared with a Forward-Feed Multiple-Effect Evaporator in the Cogeneration System of a Sugar Factory
Somchart Chantasiriwan
May 22, 2020 (v1)
Keywords: counter-current, Energy Efficiency, heat exchanger, mathematical model
The cogeneration system of a sugar factory consists of boiler, steam turbine, and sugar juice evaporation process. The multiple-effect evaporator used for the conventional sugar juice evaporation process is the forward-feed multiple-effect evaporator, in which steam and sugar juice flow in the same direction. The main objective of this paper is to investigate the energy efficiency of the backward-feed multiple-effect evaporator, in which steam and sugar juice flow in opposite directions, compared with that of the forward-feed multiple-effect evaporator. Mathematical models are developed for both multiple-effect evaporators, and used to compare the performances of two cogeneration systems that use the forward-feed and backward-feed multiple-effect evaporators. The forward-feed multiple-effect evaporator requires extracted steam from a turbine at one pressure, whereas the backward-feed multiple-effect evaporator requires steam extraction at two pressures. Both evaporators have the same t... [more]
Optimizing the Extraction of Polysaccharides from Bletilla ochracea Schltr. Using Response Surface Methodology (RSM) and Evaluating their Antioxidant Activity
Bulei Wang, Yan Xu, Lijun Chen, Guangming Zhao, Zeyuan Mi, Dinghao Lv, Junfeng Niu
May 22, 2020 (v1)
Keywords: antioxidant activities, Bletilla ochracea Schltr. polysaccharide, response surface methodology (RSM)
Bletilla ochracea Schltr. polysaccharides (BOP) have a similar structure to Bletilla striata (Thunb.) Reichb.f. (Orchidaceae) polysaccharides (BSP). Therefore, BOP can be considered as a substitute for BSP in the food, pharmaceuticals and cosmetics fields. To the best of our knowledge, little information is available regarding the optimization of extraction and antioxidant activity of BOP. In this study, response surface methodology (RSM) was firstly used for optimizing the extraction parameters of BOP. The results suggested that the optimal conditions included a temperature of 82 °C, a duration of 85 min and a liquid/material ratio of 30 mL/g. In these conditions, we received 26.45% ± 0.18% as the experimental yield. In addition, BOP exhibited strong concentration-dependent antioxidant abilities in vitro. The half-maximal effective concentration (EC50) values of BOP against 1,1-diphenyl-2-picrylhydrazyl (DPPH·), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonate) (ABTS+·), hydroxyl (... [more]
Influence of Blanching Time on Moisture, Sugars, Protein, and Processing Recovery of Sweet Corn Kernels
Mariusz Szymanek, Agata Dziwulska-Hunek, Wojciech Tanaś
May 22, 2020 (v1)
Keywords: blanching, moisture, processing recovery, protein, sugars, sweetcorn
The objective of this work is to determine the influence of blanching time on moisture content, sugars, protein, and processing recovery (degree of cut corn) of sweet corn kernels. Sweetcorn cobs of the Jubilee variety were blanched in the water at the temperature 85 °C during the period of 2, 4, 6, and 8 min. Non-blanched cobs were used as control samples. Blanched cobs were made subject to a mechanical process of cutting-off the kernels. It was stated that the blanching time has significant statistical influence on the content of moisture, sugars, and protein in kernel as well as on the quantity of the cut-off kernel mass.
Effect of Hydraulic Retention Time on Anaerobic Baffled Reactor Operation: Enhanced Biohydrogen Production and Enrichment of Hydrogen-producing Acetogens
Fan Jiang, Zhiying Peng, Huaibo Li, Ji Li, Shuo Wang
May 22, 2020 (v1)
Keywords: anaerobic baffled reactor (ABR), biohydrogen production, biohydrogen-producing acetogens (HPA), hydraulic retention time (HRT), normal molasses wastewater
Biohydrogen production by fermentation has become a promising technology developed in the world. In this study, diluted normal molasses wastewater is used as the raw material, and biohydrogen production efficiency and operation characteristics of an anaerobic baffled reactor (ABR) are studied. The effect of hydraulic retention time (HRT) on biohydrogen production efficiency and operating characteristics of ABR is extensively discussed. Experimental results showed that methanogen residuals were still observed in the last three compartments under HRT of 24 h and COD(Chemical oxygen demand) concentration of 8000 mg/L. Meanwhile, the first three compartments presented an ethanol fermentation type. The characteristics of butyric acid fermentation in Compartment IV were also enhanced. The average removal efficiency of COD was reduced to 15.4%. The average rates of biohydrogen production and specific biohydrogen production were 12.85 and 360.22 L/kg COD, respectively. The extension of HRT was... [more]
A Proposal for Public Health Information System-Based Health Promotion Services
Kichan Yoon, Sewon Park, Solji Choi, Munjae Lee
May 22, 2020 (v1)
Keywords: health promotion project, health promotion services, Korea, primary care, public health information system
This study aims to examine the current status and utilization of 22 health promotion projects that use the health care information system. We investigate the health promotion examination results for a counseling project held at health centers, which use information connected with the Health Insurance Corporation. First, we review the status of 22 health promotion projects, including 13 integrated health promotion projects and 9 other health promotion projects. Next, we examine the linkages between the 22 projects and other health promotion systems. Consequently, despite accumulating vast amounts of data, only 10 places could be linked to health promotion data in the health and medical information system; the Social Security Information Service was the only exception to this trend. The Public Health Information System (PHIS) had the lowest data utilization rate in the project. The study results show that it is necessary to utilize data from local health and medical institutions in order... [more]
In-Situ Yeast Fermentation Medium in Fortifying Protein and Lipid Accumulations in the Harvested Larval Biomass of Black Soldier Fly
Chung Yiin Wong, Yeek Chia Ho, Jun Wei Lim, Pau Loke Show, Siewhui Chong, Yi Jing Chan, Chii Dong Ho, Mardawani Mohamad, Ta Yeong Wu, Man Kee Lam, Guan Ting Pan
May 22, 2020 (v1)
Subject: Biosystems
Keywords: black soldier fly, coconut endosperm waste, Fermentation, larvae, organic waste, protein, yeast
Recently, worldwide researchers have been focusing on exploiting of black soldier fly larval (BSFL) biomass to serve as the feed mediums for farmed animals, including aquaculture farming, in order to assuage the rising demands for protein sources. In this study, yeast was introduced into coconut endosperm waste (CEW) whilst serving as the feeding medium to rear BSFL in simultaneously performed in situ fermentation. It was found that at a 2.5 wt% yeast concentration, the total biomass gained, growth rate and rearing time were improved to 1.145 g, 0.085 g/day and 13.5 days, respectively. In terms of solid waste reduction, the inoculation of yeast over 0.5 wt% in CEW was able to achieve more than 50% overall degradation, with the waste reduction indexes (WRIs) ranging from 0.038 to 0.040 g/day. Disregarding the concentration of yeast introduced, the protein productivity from 20 BSFL was enhanced from only 0.018 g/day (the control) to 0.025 g/day with the presence of yeast at arbitrary con... [more]
Secondary Metabolites Profiling, Biological Activities and Computational Studies of Abutilon figarianum Webb (Malvaceae)
Hammad Saleem, Muhammad Sarfraz, Hafiz Muhammad Ahsan, Umair Khurshid, Syed Asif Jahanzeb Kazmi, Gokhan Zengin, Marcello Locatelli, Irshad Ahmad, Hassan H. Abdallah, Mohamad Fawzi Mahomoodally, Kannan RR Rengasamy, Nafees Ahemad
May 22, 2020 (v1)
Subject: Biosystems
Keywords: antioxidant, bioactive molecules, docking, enzyme inhibition, phytochemical
This research endeavors to inspect the chemical and biological profiling of methanol and dichloromethane (DCM) extracts prepared from Abutilon figarianum Webb. Total bioactive constituents and secondary metabolites were assessed via ultra-high performance liquid chromatography (UHPLC-MS). Biological effects were evaluated via antioxidant and enzymes inhibitory assays. The methanol extract was able to give the highest phenolic (51.92 mg GAE/g extract) and flavonoid (72.59 mg QE/g extract) contents and was found to contain 11 bioactive metabolites, including flavonoid, alkaloid, phenolic and fatty acid derivatives, as accessed by UHPLC-MS analysis. Similarly, the phytochemical profiling of the DCM extract tentatively identified the 12 different secondary metabolites, most of these were fatty acid derivatives. The methanol extract was most active in the radical scavenging, reducing power and total antioxidant power assays, while dichloromethane extract showed the highest metal chelating a... [more]
New Hybrid Bioactive Composites for Bone Substitution
Anna Ślósarczyk, Joanna Czechowska, Ewelina Cichoń, Aneta Zima
May 22, 2020 (v1)
Subject: Materials
Keywords: chitosan, hybrid materials, hydroxyapatite
Recently, intensive efforts have been undertaken to find new, superior biomaterial solutions in the field of hybrid inorganic−organic materials. In our studies, biomicroconcretes containing hydroxyapatite (HAp)−chitosan (CTS) granules dispersed in an α tricalcium phospahate (αTCP) matrix were investigated. The influence of CTS content and the size of granules on the physicochemical properties of final bone implant materials (setting time, porosity, mechanical strength, and phase composition) were evaluated. The obtained materials were found to be promising bone substitutes for use in non-load bearing applications.
Wastewater Treatment Processes: Part I
George Z. Kyzas, Kostas A. Matis
May 22, 2020 (v1)
Cheap and plentiful, water was for centuries a manufacturing tool that industry took for granted [...]
Model-Free Adaptive Direct Torque Control for the Speed Regulation of Asynchronous Motors
Ziwei Zhang, Shangtai Jin, Genfeng Liu, Zhongsheng Hou, Jianmin Zheng
May 22, 2020 (v1)
Keywords: asynchronous motor, model-free adaptive control, nonlinear system, speed regulation
In this paper, a model-free adaptive direct torque control (MFADTC) method for the speed regulation of asynchronous motors is proposed to solve the problems of modeling difficulties and poor anti-disturbance ability of the asynchronous motor. The designed model-free adaptive direct torque control (MFADTC) method depends merely on the input and the output data of the asynchronous motor. Numerical simulations are provided to show that this method has significantly improved the system’s anti-disturbance ability.
Dual Solutions and Stability Analysis of Magnetized Hybrid Nanofluid with Joule Heating and Multiple Slip Conditions
Liang Yan, Sumera Dero, Ilyas Khan, Irshad Ali Mari, Dumitru Baleanu, Kottakkaran Sooppy Nisar, El-Sayed M. Sherif, Hany S. Abdo
May 22, 2020 (v1)
Keywords: dual solution, hybrid nanofluid, Joule heating, slip conditions, stability analysis
This paper investigates the steady, two dimensional, and magnetohydrodynamic flow of copper and alumina/water hybrid nanofluid on a permeable exponentially shrinking surface in the presence of Joule heating, velocity slip, and thermal slip parameters. Adopting the model of Tiwari and Das, the mathematical formulation of governing partial differential equations was constructed, which was then transformed into the equivalent system of non-linear ordinary differential equations by employing exponential similarity transformation variables. The resultant system was solved numerically using the BVP4C solver in the MATLAB software. For validation purposes, the obtained numerical results were compared graphically with those in previous studies, and found to be in good agreement, as the critical points are the same up to three decimal points. Based on the numerical results, it was revealed that dual solutions exist within specific ranges of the suction and magnetic parameters. Stability analysi... [more]
Integration of Time-Series Transcriptomic Data with Genome-Scale CHO Metabolic Models for mAb Engineering
Zhuangrong Huang, Seongkyu Yoon
May 22, 2020 (v1)
Subject: Biosystems
Keywords: CHO cell, genome-scale metabolic model, omics data integration, time-series transcriptomics
Chinese hamster ovary (CHO) cells are the most commonly used cell lines in biopharmaceutical manufacturing. Genome-scale metabolic models have become a valuable tool to study cellular metabolism. Despite the presence of reference global genome-scale CHO model, context-specific metabolic models may still be required for specific cell lines (for example, CHO-K1, CHO-S, and CHO-DG44), and for specific process conditions. Many integration algorithms have been available to reconstruct specific genome-scale models. These methods are mainly based on integrating omics data (i.e., transcriptomics, proteomics, and metabolomics) into reference genome-scale models. In the present study, we aimed to investigate the impact of time points of transcriptomics integration on the genome-scale CHO model by assessing the prediction of growth rates with each reconstructed model. We also evaluated the feasibility of applying extracted models to different cell lines (generated from the same parental cell line... [more]
Phytochemical Compounds of Branches from P. halepensis Oily Liquid Extract and S. terebinthifolius Essential Oil and Their Potential Antifungal Activity
Abeer A. Mohamed, Said I. Behiry, Hayssam M. Ali, Mervat EL-Hefny, Mohamed Z.M. Salem, Nader A. Ashmawy
May 22, 2020 (v1)
Subject: Biosystems
Keywords: essential oil, fungi, oily liquid extract, P. halepensis, S. terebinthifolius, wood bio-fungicide
In the present study, the antifungal activity of wood treated with Pinus halepensis branch n-hexane oily liquid extract (OLE) and Schinus terebinthifolius branch essential oil (EO) was evaluated against the growth of four phytopathogenic fungi—Bipolaris oryzae, Fusarium oxysporum, Fusarium solani, and Rhizoctonia solani. Air-dried wood samples of Pinus roxburghii were autoclaved, and each wood received 100 µL of the concentrated oils from P. halepensis and S. terebinthifolius. The main compounds identified in S. terebinthifolius branch EO were terpinen-4-ol (18.25%), cis-β-terpineol (15.60%), γ-terpinene (12.46%), sabinene (9.83%), α-terpinene (8.56%), and 4-thujanol (6.71%), while the main compounds in P. halepensis branch HeO were 2-undecenal (22.25%), 4-hydroxy-10-methyl-3,4,7,8,9,10-hexahydro-2H-oxecin-2-one (8.43%), (Z)-2-decenal (6.88%), nonanal (5.85%), (2E)-2-decenal (4.65%), (E,E)-2,4-decadienal (4.41%), arachidonic acid methyl ester (4.36%), and 2-(7-heptadecynyloxy)tetrahydr... [more]
Ecofriendly Preparation and Characterization of a Cassava Starch/Polybutylene Adipate Terephthalate Film
Tan Yi, Minghui Qi, Qi Mo, Lijie Huang, Hanyu Zhao, Di Liu, Hao Xu, Chongxing Huang, Shuangfei Wang, Yang Liu
May 22, 2020 (v1)
Subject: Materials
Keywords: mechanical properties, nano-zinc oxide, PBAT, plasticization, TPS
Composite films of polybutylene adipate terephthalate (PBAT) were prepared by adding thermoplastic starch (TPS) (TPS/PBAT) and nano-zinc oxide (nano-ZnO) (TPS/PBAT/nano-ZnO). The changes of surface morphology, thermal properties, crystal types and functional groups of starch during plasticization were analyzed by scanning electron microscopy, synchronous thermal analysis, X-ray diffraction, infrared spectrometry, mechanical property tests, and contact Angle and transmittance tests. The relationship between the addition of TPS and the tensile strength, transmittance, contact angle, water absorption, and water vapor barrier of the composite film, and the influence of nano-ZnO on the mechanical properties and contact angle of the 10% TPS/PBAT composite film. Experimental results show that, after plasticizing, the crystalline form of starch changed from A-type to V-type, the functional group changed and the lipophilicity increased; the increase of TPS content, the light transmittance and m... [more]
Study of Activation Energy on the Movement of Gyrotactic Microorganism in a Magnetized Nanofluids Past a Porous Plate
Muhammad Mubashir Bhatti, Anwar Shahid, Tehseen Abbas, Sultan Z Alamri, Rahmat Ellahi
May 22, 2020 (v1)
Keywords: bio-convection, electro-conductive polymer processing, gyrotactic microorganisms, porous media
The present study deals with the swimming of gyrotactic microorganisms in a nanofluid past a stretched surface. The combined effects of magnetohydrodynamics and porosity are taken into account. The mathematical modeling is based on momentum, energy, nanoparticle concentration, and microorganisms’ equation. A new computational technique, namely successive local linearization method (SLLM), is used to solve nonlinear coupled differential equations. The SLLM algorithm is smooth to establish and employ because this method is based on a simple univariate linearization of nonlinear functions. The numerical efficiency of SLLM is much powerful as it develops a series of equations which can be subsequently solved by reutilizing the data from the solution of one equation in the next one. The convergence was improved through relaxation parameters in the study. The accuracy of SLLM was assured through known methods and convergence analysis. A comparison of the proposed method with the existing lit... [more]
Thermal Behavior of a Rod during Hot Shape Rolling and Its Comparison with a Plate during Flat Rolling
Joong-Ki Hwang
May 22, 2020 (v1)
Keywords: flat rolling, shape rolling, temperature distribution, wire rod
The thermal behavior of a rod during the hot shape rolling process was investigated using the off-line hot rolling simulator and numerical simulation. Additionally, it was compared with a plate during the flat rolling process to understand the thermal behavior of the rod during the hot rolling process in more detail. The temperature of the rod and plate during the hot rolling process was measured at several points with thermocouples using the rolling simulator, and then the measured temperature of each region of a workpiece was analyzed with numerical simulation. During hot rolling process, the temperature distribution of the rod was very different from the plate. The temperature deviation of the rod with area was much higher than that of the plate. The variation in effective stress of the rod along the circumferential direction can induce the temperature difference with area of the rod, whereas the plate had a relatively lower temperature deviation with area due to the uniform effecti... [more]
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