Search results for: enhanced steam reforming
2218 The Synthesis of AgInS₂/SnS₂/RGO Heterojunctions with Enhanced Photocatalytic Degradation of Norfloxacin
Authors: Mingmei Zhang, Xinyong Li
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Novel AgInS2/SnS2/RGO (AISR) heterojunctions photocatalysts were synthesized by simple hydrothermal method. The morphology and composition of the fabricated AISR nanocomposites were investigated by field-emission scanning electron microscopy (SEM), X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). Moreover, the as-prepared AISR photocatalysts exhibited excellent photocatalytic activities for the degradation of Norfloxacin (NOR), mainly due to its high optical absorption and separation efficiency of photogenerated electron-hole pairs, as evidenced by UV–vis diffusion reflection spectra (DRS) and Surface photovoltage (SPV) spectra. Furthermore, laser flash photolysis technique was conducted to test the lifetime of charge carriers of the fabricated nanocomposites. The interfacial charges transfer mechanism was also discussed.Keywords: AISR heterojunctions, electron-hole pairs, SPV spectra, charges transfer mechanism
Procedia PDF Downloads 1812217 Heat Transfer Studies on CNT Nanofluids in a Turbulent Flow Heat Exchanger
Authors: W. Rashmi, M. Khalid, O. Seiksan, R. Saidur, A. F. Ismail
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Nanofluids have received much more attention since its discovery. They are believed to be promising coolants in heat transfer applications due to their enhanced thermal conductivity and heat transfer characteristics. In this study, the enhancement in heat transfer of CNT-nanofluids under turbulent flow conditions is investigated experimentally. Carbon nanotube (CNTs) concentration was varied between 0.051-0.085 wt%. The nanofluid suspension was stabilized by gum arabic (GA) through a process of homogenisation and sonication. The flow rates of cold fluid (water) is varied from 1.7-3 L/min and flow rates of the hot fluid is varied between 2-3.5 L/min. Thermal conductivity, density and viscosity of the nanofluids were also measured as a function of temperature and CNT concentration. The experimental results are validated with theoretical correlations for turbulent flow available in the literature. Results showed an enhancement in heat transfer range between 9-67% as a function of temperature and CNT concentration.Keywords: nanofluids, carbon nanotubes (CNT), heat transfer enhancement, heat transfer
Procedia PDF Downloads 5002216 Inhibition of Influenza Replication through the Restrictive Factors Modulation by CCR5 and CXCR4 Receptor Ligands
Authors: Thauane Silva, Gabrielle do Vale, Andre Ferreira, Marilda Siqueira, Thiago Moreno L. Souza, Milene D. Miranda
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The exposure of A(H1N1)pdm09-infected epithelial cells (HeLa) to HIV-1 viral particles, or its gp120, enhanced interferon-induced transmembrane protein (IFITM3) content, a viral restriction factor (RF), resulting in a decrease in influenza replication. The gp120 binds to CCR5 (R5) or CXCR4 (X4) cell receptors during HIV-1 infection. Then, it is possible that the endogenous ligands of these receptors also modulate the expression of IFITM3 and other cellular factors that restrict influenza virus replication. Thus, the aim of this study is to analyze the role of cellular receptors R5 and X4 in modulating RFs in order to inhibit the replication of the influenza virus. A549 cells were treated with 2x effective dose (ED50) of endogenous R5 or X4 receptor agonists, CCL3 (20 ng/ml), CCL4 (10 ng/ml), CCL5 (10 ng/ml) and CXCL12 (100 ng/mL) or exogenous agonists, gp120 Bal-R5, gp120 IIIB-X4 and its mutants (5 µg/mL). The interferon α (10 ng/mL) and oseltamivir (60 nM) were used as a control. After 24 h post agonists exposure, the cells were infected with virus influenza A(H3N2) at 2 MOI (multiplicity of infection) for 1 h. Then, 24 h post infection, the supernatant was harvested and, the viral titre was evaluated by qRT-PCR. To evaluate IFITM3 and SAM and HD domain containing deoxynucleoside triphosphate triphosphohydrolase 1 (SAMHD1) protein levels, A549 were exposed to agonists for 24 h, and the monolayer was lysed with Laemmli buffer for western blot (WB) assay or fixed for indirect immunofluorescence (IFI) assay. In addition to this, we analyzed other RFs modulation in A549, after 24 h post agonists exposure by customized RT² Profiler Polymerase Chain Reaction Array. We also performed a functional assay in which SAMHD1-knocked-down, by single-stranded RNA (siRNA), A549 cells were infected with A(H3N2). In addition, the cells were treated with guanosine to assess the regulatory role of dNTPs by SAMHD1. We found that R5 and X4 agonists inhibited influenza replication in 54 ± 9%. We observed a four-fold increase in SAMHD1 transcripts by RFs mRNA quantification panel. After 24 h post agonists exposure, we did not observe an increase in IFITM3 protein levels through WB or IFI assays, but we observed an upregulation up to three-fold in the protein content of SAMHD1, in A549 exposed to agonists. Besides this, influenza replication enhanced in 20% in cell cultures that SAMDH1 was knockdown. Guanosine treatment in cells exposed to R5 ligands further inhibited influenza virus replication, suggesting that the inhibitory mechanism may involve the activation of the SAMHD1 deoxynucleotide triphosphohydrolase activity. Thus, our data show for the first time a direct relationship of SAMHD1 and inhibition of influenza replication, and provides perspectives for new studies on the signaling modulation, through cellular receptors, to induce proteins of great importance in the control of relevant infections for public health.Keywords: chemokine receptors, gp120, influenza, virus restriction factors
Procedia PDF Downloads 1412215 Chemical Bath Deposition Technique of CdS Used in Closed Space Sublimation of CdTe Solar Cell
Authors: Z. Mahmood, F. U. Babar, S. Naz, H. U. Rehman
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Cadmium Sulphide (CdS) was deposited on a Tec 15 glass substrate with the help of CBD (chemical bath deposition process) and then cadmium telluride CdTe was deposited on CdS with the help of CSS (closed spaced sublimation technique) for the construction of a solar cell. The thicknesses of all the deposited materials were measured with the help of Ellipsometry. The IV graphs were drawn in order to observe the current voltage output. The efficiency of the cell was graphed with the fill factor as well (graphs not given here). The efficiency came out to be approximately 16.5 % and the CIGS (copper-indium–gallium-selenide) maximum efficiency is 20 %. The efficiency of a solar cell can further be enhanced by adapting quality materials, good experimental devices and proper procedures. The grain size was analyzed with the help of scanning electron microscope using RBS (Rutherford backscattering spectroscopy).Keywords: Chemical Bath Deposition Technique (CBD), cadmium sulphide (CdS), CdTe, CSS (Closed Space Sublimation)
Procedia PDF Downloads 3642214 Use of Technology to Improve Students’ Attitude in Learning Mathematics of Non- Mathematics Undergraduate Students
Authors: Asia Majeed
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The learning of mathematics in science, engineering and social science programs can be enhanced through practical problem-solving techniques. The instructors can design their lessons with some strategies to improve students’ educational needs and accomplishments in mathematics classrooms. The use of technology in class problem solving and application sessions can enhance deep understanding of mathematics among students. As mathematician, we believe in subject specific and content-driven teaching methods. Through technology the relationship between the physical problems and the mathematical models can be analyzed. This paper is about selective use of technology in mathematics classrooms and helpful to others mathematics instructors who wishes to improve their traditional teaching techniques to improve students’ attitude in learning mathematics. These techniques corpus can be used in teaching large mathematics classes in science, technology, engineering, and social science.Keywords: attitude in learning mathematics, mathematics, non-mathematics undergraduate students, technology
Procedia PDF Downloads 2222213 Effects of Alkaline Pretreatment Parameters on the Corrosion Resistance and Wettability of Magnesium Implant
Authors: Mahtab Assadian, Mohd Hasbullah Idris, Mostafa Rezazadeh Shirdar, Mohammad Mahdi Taheri, S. Izman
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Corrosion behaviour and surface roughness of magnesium substrate were investigated after NaOH pretreatment in different concentrations (1, 5, and 10 molar) and duration of (10 min, 30 min, 1 h, 3 h, 6 h and 24 h). Creation of Mg(OH)2 barrier layer after pretreatment enhanced corrostion resistance as well as wettability of substrate surface. Characterization including Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) was conducted to detect the existence of this barrier layer. Surface roughness and wettability of substrate was evaluated using atomic force microscopy (AFM) and contact angle measurement respectively. It is found that magnesium treated by 1M NaOH for 30 min reveals higher corrosion resistance and lower water contact angle of substrate surface. In addition, this investigation indicates that pH value of SBF solution is strongly influenced by different time and concentration of alkaline pretreatment.Keywords: magnesium, NaOH pretreatment, corrosion resistance, wettability
Procedia PDF Downloads 9612212 Detection of Abnormal Process Behavior in Copper Solvent Extraction by Principal Component Analysis
Authors: Kirill Filianin, Satu-Pia Reinikainen, Tuomo Sainio
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Frequent measurements of product steam quality create a data overload that becomes more and more difficult to handle. In the current study, plant history data with multiple variables was successfully treated by principal component analysis to detect abnormal process behavior, particularly, in copper solvent extraction. The multivariate model is based on the concentration levels of main process metals recorded by the industrial on-stream x-ray fluorescence analyzer. After mean-centering and normalization of concentration data set, two-dimensional multivariate model under principal component analysis algorithm was constructed. Normal operating conditions were defined through control limits that were assigned to squared score values on x-axis and to residual values on y-axis. 80 percent of the data set were taken as the training set and the multivariate model was tested with the remaining 20 percent of data. Model testing showed successful application of control limits to detect abnormal behavior of copper solvent extraction process as early warnings. Compared to the conventional techniques of analyzing one variable at a time, the proposed model allows to detect on-line a process failure using information from all process variables simultaneously. Complex industrial equipment combined with advanced mathematical tools may be used for on-line monitoring both of process streams’ composition and final product quality. Defining normal operating conditions of the process supports reliable decision making in a process control room. Thus, industrial x-ray fluorescence analyzers equipped with integrated data processing toolbox allows more flexibility in copper plant operation. The additional multivariate process control and monitoring procedures are recommended to apply separately for the major components and for the impurities. Principal component analysis may be utilized not only in control of major elements’ content in process streams, but also for continuous monitoring of plant feed. The proposed approach has a potential in on-line instrumentation providing fast, robust and cheap application with automation abilities.Keywords: abnormal process behavior, failure detection, principal component analysis, solvent extraction
Procedia PDF Downloads 3092211 Thermodynamics of the Local Hadley Circulation Over Central Africa
Authors: Landry Tchambou Tchouongsi, Appolinaire Derbetini Vondou
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This study describes the local Hadley circulation (HC) during the December-February (DJF) and June-August (JJA) seasons, respectively, in Central Africa (CA) from the divergent component of the mean meridional wind and also from a new method called the variation of the ψ vector. Historical data from the ERA5 reanalysis for the period 1983 to 2013 were used. The results show that the maximum of the upward branch of the local Hadley circulation in the DJF and JJA seasons is located under the Congo Basin (CB). However, seasonal and horizontal variations in the mean temperature gradient and thermodynamic properties are largely associated with the distribution of convection and large-scale upward motion. Thus, temperatures beneath the CB show a slight variation between the DJF and JJA seasons. Moreover, energy transport of the moist static energy (MSE) adequately captures the mean flow component of the HC over the tropics. By the way, the divergence under the CB is enhanced by the presence of the low pressure of western Cameroon and the contribution of the warm and dry air currents coming from the Sahara.Keywords: Circulation, reanalysis, thermodynamic, local Hadley.
Procedia PDF Downloads 892210 Public Health Informatics: Potential and Challenges for Better Life in Rural Communities
Authors: Shishir Kumar, Chhaya Gangwal, Seema Raj
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Public health informatics (PHI) which has seen successful implementation in the developed world, become the buzzword in the developing countries in providing improved healthcare with enhanced access. In rural areas especially, where a huge gap exists between demand and supply of healthcare facilities, PHI is being seen as a major solution. There are factors such as growing network infrastructure and the technological adoption by the health fraternity which provide support to these claims. Public health informatics has opportunities in healthcare by providing opportunities to diagnose patients, provide intra-operative assistance and consultation from a remote site. It also has certain barriers in the awareness, adaptation, network infrastructure, funding and policy related areas. There are certain medico-legal aspects involving all the stakeholders which need to be standardized to enable a working system. This paper aims to analyze the potential and challenges of public health informatics services in rural communities.Keywords: PHI, e-health, public health, health informatics
Procedia PDF Downloads 3762209 Viable Use of Natural Extract Solutions from Tuberous and Cereals to Enhance the Synthesis of Activated Carbon-Graphene Composite
Authors: Pamphile Ndagijimana, Xuejiao Liu, Zhiwei Li, Yin Wang
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Enhancing the properties of activated carbon is very imperative for various applications. Indeed, the activated carbon has promising physicochemical properties desired for a considerable number of applications. In this regard, we are proposing an enhanced and green technology for increasing the efficiency and performance of the activated carbon to various applications. The technique poses on the use of natural extracts from tuberous and cereals based-solutions. These solutions showed high potentiality to be used in the synthesis of activated carbon-graphene composite with only 3 mL. The extracted liquid from tuberous sourcing was enough to induce precipitation within a fraction of a minute in contrast to that from cereal sourced. Using these extracts, a synthesis of activated carbon-graphene composite was successful. Different characterization techniques such as XRD, SEM, FTIR, BET, and Raman spectroscopy were performed to investigate the composite materials. The results confirmed a conjugation between activated carbon and graphene material.Keywords: activated carbon, cereals, extract solution, graphene, tuberous
Procedia PDF Downloads 1462208 Laryngeal Tuberculosis in a 7-Year-Old Child: A Case Report and Literature Review
Authors: Mohd Jaish Siddiqui
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Laryngeal TB is extremely rare in the pediatric population, accounting for 1% of all cases. Here, we present a case of laryngeal TB with miliary tuberculosis and tuberculous encephalitis, presented with sore throat, hoarseness, severe cough and, acute obstruction the larynx, sputum for AFB was negative, T-SPOT was positive and X-pert was positive, bronchoscopy revealed multiple nodules and edema around the larynx, epiglottis, bilateral arytenopharyngeal folds and vocal cord. Enhanced MRI revealed multiple small nodules in bilateral cerebral hemispheres and right thalamus, however CSF was negative. We reviewed the LTB cases that were published up to 2021. A total of twenty fine cases were identified in English literature. The most common manifestation was hoarseness of voice with 80% followed by stridor 40% of cases. Pulmonary involvement was found in 36% of cases, whereas, 45% of cases had no underlying TB. We did not find any case who developed tuberculous encephalitis in the literature.Keywords: laryngeal tb, treatment, tuberculous encephalitis, children
Procedia PDF Downloads 462207 Comparison of Cu Nanoparticle Formation and Properties with and without Surrounding Dielectric
Authors: P. Dubcek, B. Pivac, J. Dasovic, V. Janicki, S. Bernstorff
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When grown only to nanometric sizes, metallic particles (e.g. Ag, Au and Cu) exhibit specific optical properties caused by the presence of plasmon band. The plasmon band represents collective oscillation of the conduction electrons, and causes a narrow band absorption of light in the visible range. When the nanoparticles are embedded in a dielectric, they also cause modifications of dielectrics optical properties. This can be fine-tuned by tuning the particle size. We investigated Cu nanoparticle growth with and without surrounding dielectric (SiO2 capping layer). The morphology and crystallinity were investigated by GISAXS and GIWAXS, respectively. Samples were produced by high vacuum thermal evaporation of Cu onto monocrystalline silicon substrate held at room temperature, 100°C or 180°C. One series was in situ capped by 10nm SiO2 layer. Additionally, samples were annealed at different temperatures up to 550°C, also in high vacuum. The room temperature deposited samples annealed at lower temperatures exhibit continuous film structure: strong oscillations in the GISAXS intensity are present especially in the capped samples. At higher temperatures enhanced surface dewetting and Cu nanoparticles (nanoislands) formation partially destroy the flatness of the interface. Therefore the particle type of scattering is enhanced, while the film fringes are depleted. However, capping layer hinders particle formation, and continuous film structure is preserved up to higher annealing temperatures (visible as strong and persistent fringes in GISAXS), compared to the non- capped samples. According to GISAXS, lateral particle sizes are reduced at higher temperatures, while particle height is increasing. This is ascribed to close packing of the formed particles at lower temperatures, and GISAXS deduced sizes are partially the result of the particle agglomerate dimensions. Lateral maxima in GISAXS are an indication of good positional correlation, and the particle to particle distance is increased as the particles grow with temperature elevation. This coordination is much stronger in the capped and lower temperature deposited samples. The dewetting is much more vigorous in the non-capped sample, and since nanoparticles are formed in a range of sizes, correlation is receding both with deposition and annealing temperature. Surface topology was checked by atomic force microscopy (AFM). Capped sample's surfaces were smoother and lateral size of the surface features were larger compared to the non-capped samples. Altogether, AFM results suggest somewhat larger particles and wider size distribution, and this can be attributed to the difference in probe size. Finally, the plasmonic effect was monitored by UV-Vis reflectance spectroscopy, and relative weak plasmonic effect could be explained by uncomplete dewetting or partial interconnection of the formed particles.Keywords: coper, GISAXS, nanoparticles, plasmonics
Procedia PDF Downloads 1232206 Visible-Light Induced Photocatalytic Degradation of Dye Molecules over ZnWO4-Bi2WO6 Composite
Authors: Sudarat Issarapanacheewin, Katcharin Wetchakun, Sukon Phanichphant, Wiyong Kangwansupamonkon, Natda Wetchakun
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The photocatalytic degradation of Methylene blue (MB) and Rhodamine B (RhB) in the presence of ZnWO4-Bi2WO6 composite under visible light irradiation (λ ≥ 400 nm) were studied in this research. The structural and photophysical properties of ZnWO4-Bi2WO6 composite on the photocatalytic degradation process were investigated. The as-prepared ZnWO4-Bi2WO6 composite photocatalyst exhibits wide absorption in the visible-light region and display superior visible-light-driven photocatalytic activities in degradation of MB and RhB. The enhanced photocatalytic activity was attributed to electron-hole separation with the appropriate band potential and the physicochemical properties of ZnWO4 and Bi2WO6. The main active species for the degradation of organic dyes were investigated to explain the enhancement of photocatalytic performance of ZnWO4-Bi2WO6 composite. The possible photocatalytic degradation pathway of aqueous MB and RhB dyes and charge transfer of ZnWO4-Bi2WO6 composite was proposed.Keywords: composite, dyes, photocatalytic activity, ZnWO4-Bi2WO6
Procedia PDF Downloads 3022205 Nest-Building Using Place Cells for Spatial Navigation in an Artificial Neural Network
Authors: Thomas E. Portegys
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An animal behavior problem is presented in the form of a nest-building task that involves two cooperating virtual birds, a male and female. The female builds a nest into which she lays an egg. The male's job is to forage in a forest for food for both himself and the female. In addition, the male must fetch stones from a nearby desert for the female to use as nesting material. The task is completed when the nest is built, and an egg is laid in it. A goal-seeking neural network and a recurrent neural network were trained and tested with little success. The goal-seeking network was then enhanced with “place cells”, allowing the birds to spatially navigate the world, building the nest while keeping themselves fed. Place cells are neurons in the hippocampus that map space.Keywords: artificial animal intelligence, artificial life, goal-seeking neural network, nest-building, place cells, spatial navigation
Procedia PDF Downloads 592204 Exploring Distinct Materials for Hydrogen Storage: A Density Functional Theory Approach
Authors: Abdalla Ahmad Obeidat
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Developing efficient hydrogen storage materials is critical to advancing clean energy technologies, particularly for applications in fuel cells and renewable energy systems. This study explores materials for hydrogen storage through Density Functional Theory (DFT) calculations, addressing one of the most significant challenges in sustainable energy: the safe and efficient storage and release of hydrogen. Our research provides an in-depth analysis of various candidate compounds' structural and electronic properties, aiming to identify materials with enhanced hydrogen storage capacities. By investigating adsorption mechanisms and optimizing key material properties, we aim to contribute to developing high-performance hydrogen storage solutions. The findings from this work have the potential to impact the field of hydrogen fuel technology significantly, offering insights and advancements that support the transition to sustainable energy systems.Keywords: hydrogen storage, density functional theory, electronic, thermal stability
Procedia PDF Downloads 112203 Impediments to Female Sports Management and Participation: The Experience in the Selected Nigeria South West Colleges of Education
Authors: Saseyi Olaitan Olaoluwa, Osifeko Olalekan Remigious
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The study was meant to identify the impediments to female sports management and participation in the selected colleges. Seven colleges of education in the south west parts of the country were selected for the study. A total of one hundred and five subjects were sampled to supply data. Only one hundred adequately completed and returned, copies of the questionnaire were used for data analysis. The collected data were analysed descriptively. The result of the study showed that inadequate fund, personnel, facilities equipment, supplies, management of sports, supervision and coaching were some of the impediments to female sports management and participation. Athletes were not encouraged to participate. Based on the findings, it was recommended that the government should come to the aid of the colleges by providing fund and other needs that will make sports attractive for enhanced participation.Keywords: female sports, impediments, management, Nigeria, south west, colleges
Procedia PDF Downloads 4092202 Geometric Optimisation of Piezoelectric Fan Arrays for Low Energy Cooling
Authors: Alastair Hales, Xi Jiang
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Numerical methods are used to evaluate the operation of confined face-to-face piezoelectric fan arrays as pitch, P, between the blades is varied. Both in-phase and counter-phase oscillation are considered. A piezoelectric fan consists of a fan blade, which is clamped at one end, and an extremely low powered actuator. This drives the blade tip’s oscillation at its first natural frequency. Sufficient blade tip speed, created by the high oscillation frequency and amplitude, is required to induce vortices and downstream volume flow in the surrounding air. A single piezoelectric fan may provide the ideal solution for low powered hot spot cooling in an electronic device, but is unable to induce sufficient downstream airflow to replace a conventional air mover, such as a convection fan, in power electronics. Piezoelectric fan arrays, which are assemblies including multiple fan blades usually in face-to-face orientation, must be developed to widen the field of feasible applications for the technology. The potential energy saving is significant, with a 50% power demand reduction compared to convection fans even in an unoptimised state. A numerical model of a typical piezoelectric fan blade is derived and validated against experimental data. Numerical error is found to be 5.4% and 9.8% using two data comparison methods. The model is used to explore the variation of pitch as a function of amplitude, A, for a confined two-blade piezoelectric fan array in face-to-face orientation, with the blades oscillating both in-phase and counter-phase. It has been reported that in-phase oscillation is optimal for generating maximum downstream velocity and flow rate in unconfined conditions, due at least in part to the beneficial coupling between the adjacent blades that leads to an increased oscillation amplitude. The present model demonstrates that confinement has a significant detrimental effect on in-phase oscillation. Even at low pitch, counter-phase oscillation produces enhanced downstream air velocities and flow rates. Downstream air velocity from counter-phase oscillation can be maximally enhanced, relative to that generated from a single blade, by 17.7% at P = 8A. Flow rate enhancement at the same pitch is found to be 18.6%. By comparison, in-phase oscillation at the same pitch outputs 23.9% and 24.8% reductions in peak downstream air velocity and flow rate, relative to that generated from a single blade. This optimal pitch, equivalent to those reported in the literature, suggests that counter-phase oscillation is less affected by confinement. The optimal pitch for generating bulk airflow from counter-phase oscillation is large, P > 16A, due to the small but significant downstream velocity across the span between adjacent blades. However, by considering design in a confined space, counterphase pitch should be minimised to maximise the bulk airflow generated from a certain cross-sectional area within a channel flow application. Quantitative values are found to deviate to a small degree as other geometric and operational parameters are varied, but the established relationships are maintained.Keywords: piezoelectric fans, low energy cooling, power electronics, computational fluid dynamics
Procedia PDF Downloads 2212201 Magnetic Field Effects on Parabolic Graphene Quantum Dots with Topological Defects
Authors: Defne Akay, Bekir S. Kandemir
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In this paper, we investigate the low-lying energy levels of the two-dimensional parabolic graphene quantum dots (GQDs) in the presence of topological defects with long range Coulomb impurity and subjected to an external uniform magnetic field. The low-lying energy levels of the system are obtained within the framework of the perturbation theory. We theoretically demonstrate that a valley splitting can be controlled by geometrical parameters of the graphene quantum dots and/or by tuning a uniform magnetic field, as well as topological defects. It is found that, for parabolic graphene dots, the valley splitting occurs due to the introduction of spatial confinement. The corresponding splitting is enhanced by the introduction of a uniform magnetic field and it increases by increasing the angle of the cone in subcritical regime.Keywords: coulomb impurity, graphene cones, graphene quantum dots, topological defects
Procedia PDF Downloads 2952200 The Effect of Immobilization Conditions on Hydrogen Production from Palm Oil Mill Effluent
Authors: A. W. Zularisam, Lakhveer Singh, Mimi Sakinah Abdul Munaim
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In this study, the optimization of hydrogen production using polyethylene glycol (PEG) immobilized sludge was investigated in batch tests. Palm oil mill effluent (POME) is used as a substrate that can act as a carbon source. Experiment focus on the effect of some important affecting factors on fermentative hydrogen production. Results showed that immobilized sludge demonstrated the maximum hydrogen production rate of 340 mL/L-POME/h under follow optimal condition: amount of biomass 10 mg VSS/ g bead, PEG concentration 10%, and cell age 24 h or 40 h. More importantly, immobilized sludge not only enhanced hydrogen production but can also tolerate the harsh environment and produce hydrogen at the wide ranges of pH. The present results indicate the potential of PEG-immobilized sludge for large-scale operations as well; these factors play an important role in stable and continuous hydrogen production.Keywords: bioydrogen, immobilization, polyethylene glycol, palm oil mill effluent, dark fermentation
Procedia PDF Downloads 3432199 Effects of Artificial Sweeteners on the Quality Parameters of Yogurt during Storage
Authors: Hafiz Arbab Sakandar, Sabahat Yaqub, Ayesha Sameen, Muhammad Imran, Sarfraz Ahmad
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Yoghurt is one of the famous nutritious fermented milk products which have myriad of positive health effects on human beings and curable against different intestinal diseases. This research was conducted to observe effects of different artificial sweeteners on the quality parameters of yoghurt with relation to storage. Some people are allergic to natural sweeteners so artificial sweetener will be helpful for them. Physical-chemical, Microbiology and various sensory evaluation tests were carried out with the interval of 7, 14, 21, and 28 days. It was outcome from this study that addition of artificial sweeteners in yoghurt has shown much harmful effects on the yoghurt microorganisms and other physicochemical parameters from quality point of view. Best results for acceptance were obtained when aspartame was added in yoghurt at level of 0.022 percent. In addition, growth of beneficial microorganisms in yoghurt was also improved as well as other sensory attributes were enhanced by the addition of aspartame.Keywords: yoghurt, artificial sweetener, storage, quality parameters
Procedia PDF Downloads 4762198 Trigonelline: A Promising Compound for The Treatment of Alzheimer's Disease
Authors: Mai M. Farid, Ximeng Yang, Tomoharu Kuboyama, Chihiro Tohda
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Trigonelline is a major alkaloid component derived from Trigonella foenum-graecum L. (fenugreek) and has been reported before as a potential neuroprotective agent, especially in Alzheimer’s disease (AD). However, the previous data were unclear and used model mice were not well established. In the present study, the effect of trigonelline on memory function was investigated in Alzheimer’s disease transgenic model mouse, 5XFAD which overexpresses the mutated APP and PS1 genes. Oral administration of trigonelline for 14 days significantly enhanced object recognition and object location memories. Plasma and cerebral cortex were isolated at 30 min, 1h, 3h, and 6 h after oral administration of trigonelline. LC-MS/MS analysis indicated that trigonelline was detected in both plasma and cortex from 30 min after, suggesting good penetration of trigonelline into the brain. In addition, trigonelline significantly ameliorated axonal and dendrite atrophy in Amyloid β-treated cortical neurons. These results suggest that trigonelline could be a promising therapeutic candidate for AD.Keywords: alzheimer’s disease, cortical neurons, LC-MS/MS analysis, trigonelline
Procedia PDF Downloads 1472197 Performance of HVOF Sprayed Ni-20CR and Cr3C2-NiCr Coatings on Fe-Based Superalloy in an Actual Industrial Environment of a Coal Fired Boiler
Authors: Tejinder Singh Sidhu
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Hot corrosion has been recognized as a severe problem in steam-powered electricity generation plants and industrial waste incinerators as it consumes the material at an unpredictably rapid rate. Consequently, the load-carrying ability of the components reduces quickly, eventually leading to catastrophic failure. The inability to either totally prevent hot corrosion or at least detect it at an early stage has resulted in several accidents, leading to loss of life and/or destruction of infrastructures. A number of countermeasures are currently in use or under investigation to combat hot corrosion, such as using inhibitors, controlling the process parameters, designing a suitable industrial alloy, and depositing protective coatings. However, the protection system to be selected for a particular application must be practical, reliable, and economically viable. Due to the continuously rising cost of the materials as well as increased material requirements, the coating techniques have been given much more importance in recent times. Coatings can add value to products up to 10 times the cost of the coating. Among the different coating techniques, thermal spraying has grown into a well-accepted industrial technology for applying overlay coatings onto the surfaces of engineering components to allow them to function under extreme conditions of wear, erosion-corrosion, high-temperature oxidation, and hot corrosion. In this study, the hot corrosion performances of Ni-20Cr and Cr₃C₂-NiCr coatings developed by High Velocity Oxy-Fuel (HVOF) process have been studied. The coatings were developed on a Fe-based superalloy, and experiments were performed in an actual industrial environment of a coal-fired boiler. The cyclic study was carried out around the platen superheater zone where the temperature was around 1000°C. The study was conducted for 10 cycles, and one cycle was consisting of 100 hours of heating followed by 1 hour of cooling at ambient temperature. Both the coatings deposited on Fe-based superalloy imparted better hot corrosion resistance than the uncoated one. The Ni-20Cr coated superalloy performed better than the Cr₃C₂-NiCr coated in the actual working conditions of the coal fired boiler. It is found that the formation of chromium oxide at the boundaries of Ni-rich splats of the coating blocks the inward permeation of oxygen and other corrosive species to the substrate.Keywords: hot corrosion, coating, HVOF, oxidation
Procedia PDF Downloads 832196 Electrochemical Performance of Al-Mn2O3 Based Electrode Materials
Authors: Noor Ul Ain Bhatti, M. Junaid Khan, Javed Ahmad, Murtaza Saleem, Shahid M. Ramay, Saadat A. Siddiqi
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Manganese oxide is being recently used as electrode material for rechargeable batteries. In this study, Al incorporated Mn2O3 compositions were synthesized to study the effect of Al doping on electrochemical performance of host material. Structural studies were carried out using X-ray diffraction analysis to confirm the phase stability and explore the lattice parameters, crystallite size, lattice strain, density and cell volume. Morphology and composition were analyzed using field emission scanning electron microscope and energy dispersive X-ray spectroscopy, respectively. Dynamic light scattering analysis was performed to observe the average particle size of the compositions. FTIR measurements exhibit the O-Al-O and O-Mn-O and Al-O bonding and with increasing the concentration of Al, the vibrational peaks of Mn-O become sharper. An enhanced electrochemical performance was observed in compositions with higher Al content.Keywords: Mn2O3, electrode materials, energy storage and conversion, electrochemical performance
Procedia PDF Downloads 3672195 Energy Efficient Routing Protocol with Ad Hoc On-Demand Distance Vector for MANET
Authors: K. Thamizhmaran, Akshaya Devi Arivazhagan, M. Anitha
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On the case of most important systematic issue that must need to be solved in means of implementing a data transmission algorithm on the source of Mobile adhoc networks (MANETs). That is, how to save mobile nodes energy on meeting the requirements of applications or users as the mobile nodes are with battery limited. On while satisfying the energy saving requirement, hence it is also necessary of need to achieve the quality of service. In case of emergency work, it is necessary to deliver the data on mean time. Achieving quality of service in MANETs is also important on while. In order to achieve this requirement, Hence, we further implement the Energy-Aware routing protocol for system of Mobile adhoc networks were it being proposed, that on which saves the energy as on every node by means of efficiently selecting the mode of energy efficient path in the routing process by means of Enhanced AODV routing protocol.Keywords: Ad-Hoc networks, MANET, routing, AODV, EAODV
Procedia PDF Downloads 3702194 Eco-Infrastructures: A Multidimensional System Approach for Urban Ecology
Authors: T. A. Mona M. Salem, Ali F. Bakr
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Given the potential devastation associated with future climate change related disasters, it is vital to change the way we build and manage our cities, through new strategies to reconfigure them and their infrastructures in ways that help secure their reproduction. This leads to a kaleidoscopic view of the city that recognizes the interrelationships of energy, water, transportation, and solid waste. These interrelationships apply across sectors and with respect to the built form of the city. The paper aims at a long-term climate resilience of cities and their critical infrastructures, and sets out an argument for including an eco-infrastructure-based approach in strategies to address climate change. As these ecosystems have a critical role to play in building resilience and reducing vulnerabilities in cities, communities and economies at risk, the enhanced protection and management of ecosystems, biological resources and habitats can mitigate impacts and contribute to solutions as nations and cities strive to adapt to climate change.Keywords: ecology, ecosystem, infrastructure, climate change, urban
Procedia PDF Downloads 3082193 Corrosion Monitoring of Weathering Steel in a Simulated Coastal-Industrial Environment
Authors: Thee Chowwanonthapunya, Junhua Dong, Wei Ke
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The atmospheres in many cities along the coastal lines in the world have been rapidly changed to coastal-industrial atmosphere. Hence, it is vital to investigate the corrosion behavior of steel exposed to this kind of environment. In this present study, Electrochemical Impedance Spectrography (EIS) and film thickness measurements were applied to monitor the corrosion behavior of weathering steel covered with a thin layer of the electrolyte in a wet-dry cyclic condition, simulating a coastal-industrial environment at 25 oC and 60 % RH. The results indicate that in all cycles, the corrosion rate increases during the drying process due to an increase in anion concentration and an acceleration of oxygen diffusion enhanced by the effect of the thinning out of the electrolyte. During the wet-dry cyclic corrosion test, the long-term corrosion behavior of this steel depends on the periods of exposure. Corrosion process is first accelerated and then decelerated. The decelerating corrosion process is contributed to the formation of the protective rust, favored by the wet-dry cycle and the acid regeneration process during the rusting process.Keywords: atmospheric corrosion, EIS, low alloy, rust
Procedia PDF Downloads 4492192 Investigations on Microstructural and Raman Scattering Properties of B2O3 Doped Ba(Ti1-xZrx)O3 Nanoceramics
Authors: Keri̇m Emre Öksüz, Şaduman Şen, Uğur Şen
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0.5 wt. % B2O3–doped Ba (Ti1-xZrx) O3, (x=0-0.4) lead-free nanoceramics were synthesized using the solid-state reaction method by adopting the ball milling technique. The influence of the substitution content on crystallographic structure, phase transition, microstructure and sintering behaviour of BT and BZT ceramics were investigated. XRD analysis at room temperature revealed a structural transformation from tetragonal to rhombohedral with enhancement of ZrO2 content in the barium titanate matrix. The scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to investigate microstructure and surface morphology of the sintered samples. The evolution of the Raman spectra was studied for various compositions, and the spectroscopic signature of the corresponding phase was determined. Scanning Electron Microscope (SEM) observations revealed enhanced microstructural uniformity and retarded grain growth with increasing Zr content.Keywords: BaTiO3, barium-titanate-zirconate, nanoceramics, raman spectroscopy
Procedia PDF Downloads 3422191 Performance Evaluation of Routing Protocols for Video Conference over MPLS VPN Network
Authors: Abdullah Al Mamun, Tarek R. Sheltami
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Video conferencing is a highly demanding facility now a days in order to its real time characteristics, but faster communication is the prior requirement of this technology. Multi Protocol Label Switching (MPLS) IP Virtual Private Network (VPN) address this problem and it is able to make a communication faster than others techniques. However, this paper studies the performance comparison of video traffic between two routing protocols namely the Enhanced Interior Gateway Protocol(EIGRP) and Open Shortest Path First (OSPF). The combination of traditional routing and MPLS improve the forwarding mechanism, scalability and overall network performance. We will use GNS3 and OPNET Modeler 14.5 to simulate many different scenarios and metrics such as delay, jitter and mean opinion score (MOS) value are measured. The simulation result will show that OSPF and BGP-MPLS VPN offers best performance for video conferencing application.Keywords: OSPF, BGP, EIGRP, MPLS, Video conference, Provider router, edge router, layer3 VPN
Procedia PDF Downloads 3312190 Solid-State Sodium Conductor for Solid-State Battery
Authors: Yumei Wang, Xiaoyu Xu, Li Lu
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Solid-state battery adopts solid-state electrolyte such as oxide- and composite-based solid electrolytes. With the adaption of nonflammable or less flammable solid electrolytes, the safety of solid-state batteries can be largely increased. NASICON (Na₃Zr₂Si₂PO₁₂, NZSP) is one of the sodium ion conductors that possess relatively high ionic conductivity, wide electrochemical stable range and good chemical stability. Therefore, it has received increased attention. We report the development of high-density NZSP through liquid phase sintering and its organic-inorganic composite electrolyte. Through reactive liquid phase sintering, the grain boundary conductivity can be largely enhanced while using an organic-inorganic composite electrolyte, interfacial wetting and impedance can be largely reduced hence being possible to fabricate scalable solid-state batteries.Keywords: solid-state electrolyte, composite electrolyte, electrochemical performance, conductivity
Procedia PDF Downloads 1232189 Deposit Guarantee Fund: One Perspective
Authors: Rute Abreu, Fátima David, Liliane Cristina Segura
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The Deposit Guarantee Fund (DGF) and its communication with the Society, in general, and with the deposit client of Financial Institutions, in particular, is discussed through the challenges of the accounting and financial report. The Bank of Portugal promotes the Portuguese Deposit Guarantee Fund (PDGF) as a financial institution that enhanced the market confidence and stability on the deposit-insurance system. Due to the nature of their functions, it must be subject to regulation and supervision that provides a first line of defense against adversely affect confidence on the Portuguese financial market. First, this research provides evidence of the effectiveness of the protection mechanisms on the deposit insurance system, which provides high and equal protection to all stakeholders. Second, it emphasizes the need of requirements of rigorous accounting process and effective financial report to reduce the moral hazard implications. Third, this research focuses on the need of total disclosure of the financial information which gives higher transparency and protection to deposit client of financial institutions.Keywords: deposit guarantee fund, Portugal, accounting, financial report
Procedia PDF Downloads 436