Search results for: accelerated failure time model
17441 Molecular Simulation of NO, NH3 Adsorption in MFI and H-ZSM5
Authors: Z. Jamalzadeh, A. Niaei, H. Erfannia, S. G. Hosseini, A. S. Razmgir
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Due to developing the industries, the emission of pollutants such as NOx, SOx, and CO2 are rapidly increased. Generally, NOx is attributed to the mono nitrogen oxides of NO and NO2 that is one of the most important atmospheric contaminants. Hence, controlling the emission of nitrogen oxides is urgent environmentally. Selective Catalytic Reduction of NOx is one of the most common techniques for NOx removal in which Zeolites have wide application due to their high performance. In zeolitic processes, the catalytic reaction occurs mostly in the pores. Therefore, investigation the adsorption phenomena of the molecules in order to gain an insight and understand the catalytic cycle is of important. Hence, in current study, molecular simulations is applied for studying the adsorption phenomena in nanocatalysts applied for SCR of NOx process. The effect of cation addition to the support in the catalysts’ behavior through adsorption step was explored by Mont Carlo (MC). Simulation time of 1 Ns accompanying 1 fs time step, COMPASS27 Force Field and the cut off radios of 12.5 Ȧ was applied for performed runs. It was observed that the adsorption capacity increases in the presence of cations. The sorption isotherms demonstrated the behavior of type I isotherm categories and sorption capacity diminished with increase in temperature whereas an increase was observed at high pressures. Besides, NO sorption showed higher sorption capacity than NH3 in H–ZSM5. In this respect, the Energy distributions signified that the molecules could adsorb in just one sorption site at the catalyst and the sorption energy of NO was stronger than the NH3 in H-ZSM5. Furthermore, the isosteric heat of sorption data showed nearly same values for the molecules; however, it indicated stronger interactions of NO molecules with H-ZSM5 Zeolite compared to the isosteric heat of NH3 which was low in value.Keywords: Monte Carlo simulation, adsorption, NOx, ZSM5
Procedia PDF Downloads 36217440 Effect of Active Compounds Extracted From Tagetes Erecta Against Plant-Parasitic Nematodes
Authors: Deepika, Kashika Kapoor, Nistha Khanna, Lakshmi, Archna Kumar
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Plant-parasitic nematodes cause major loss in global food production and destroying at least 21.3% of food annually. About 4100 species of plant-parasitic nematodes are reported, out of this, Meloidogyne species is prominent and worldwide in distribution. Observing the harmful effects of chemical based nematicides, there is a great need for an eco-friendly, highly efficient, sustainable control measure for Meloidogyne. Therefore, In vitro study was carried out to observe the impact of volatile cues obtained from the Tagetes erecta leaves on plant parasitic nematodes. Volatile cues were collected from marigold leaves. For chemical characterization, GCMS (Gas Chromatography Mass Spectrometry) profiling was conducted. VOCs (Volatile Organic Compounds) profile of marigold indicated the presence of several types of alkanes, alkenes varying in number and quantity. Status of nematodes population by counting the live and dead individuals after applying a definite volume (100µl) of extract was recorded at different concentrations (100%, 50%, 25%) with contrast of control (hexane) during different time durations i.e.,24hr, 48hr and 72hr. Result indicated that mortality increases with increasing time (72hr) and concentration (100%) i.e., 50%. Thus, application of prominent compound present in Marigold in pure form may be tested individually or in combination to find out the most efficient active compound/s, which may be highly useful in eco-friendly management of targeted plant parasitic nematode.Keywords: plant-parasitic nematode, meloidogyne, tagetes erecta, volatile organic compounds
Procedia PDF Downloads 15717439 Removal of Xylenol Orange and Eriochrome Black T Dyes from Aqueous Solution Using Chemically Activated Cocos nucifera and Mango Seed
Authors: Padmesh Tirunelveli Narayanapillai, Joel Sharwinkumar, Gaitri Saravanan
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The biosorption of Xylenol Orange (XO) and Eriochrome Black T (EBT) from aqueous solutions by chemically activated Cocos nucifera and mango seed as a low-cost, natural, and eco-friendly biosorbents was investigated. The study for biosorption of XO and EBT was optimized by different experimental parameters, initial pH 2–7, temperature 30–60 °C, biosorbent dosage 0.1 – 0.5 g, and XO: EBT dye proportions 0 – 100 by weight %. Physicochemical characteristic studies were conducted by Fourier Transform Infrared (FTIR). The equilibrium uptake was increased with an increase in the initial dye concentrations in the solution. Biosorption kinetic data were properly fitted with the pseudo-second-order kinetic model. The experimental isotherms data were analyzed using Langmuir, Freundlich, Redlich-Peterson, and Toth isotherm equations. Thermodynamic parameters ∆Go, ∆Ho, and ∆So were calculated indicating that the biosorption of Xo and EBT dye is a spontaneous and endothermic process. The Langmuir model gave the best fit by higher correlation coefficient (R2 =0.9971) for both biosorbents at optimum circumstances as pH 3, temperature 30°C, dosage 0.5 g for chemically activated Cocos nucifera and 0.4 g for chemically activated mango seeds it assumes as monolayer adsorption. The maximum dye removal efficiency was determined as 79.75% with chemically activated mango seeds compared to chemically activated Cocos nucifera. In summary, this research work showed that chemically modified activated mango seed can be effectively used as a promising low-cost biosorbent for the removal of different XO and EBT mixed dye combinations from aqueous solutions.Keywords: mixed dye proportions, xylenol orange and eriochrome black t, chemically activated cocos nucifera and mango seed, kinetic, isotherm and thermodynamic studies, FTIR
Procedia PDF Downloads 6117438 A Surrealist Play of Associations: Neoliberalism, Critical Pedagogy and Surrealism in Secondary English Language Arts
Authors: Stephanie Ho
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This project utilizes principles derived from the Surrealist movement to prioritize creative and critical thinking in secondary English Language Arts (ELA). The implementation of Surrealist-style pedagogies within an ELA classroom will be rooted in critical, radical pedagogy, which addresses the injustices caused by economic-oriented educational systems. The use of critical pedagogy will enable the subversive artistic and political aims of Surrealism to be transmitted to a classroom context. Through aesthetic reading strategies, appreciative questioning and dialogue, students will actively critique the power dynamics which structure (and often restrict) their lives. Within the ELA domain, cost-effective approaches often replace the actual “arts” of ELA. This research will therefore explore how Surrealist-oriented pedagogies could restore imaginative freedom and deconstruct conceptual barriers (normative standards, curricular constraints, and status quo power relations) in secondary ELA. This research will also examine how Surrealism can be used as a political and pedagogical model to treat societal problems mirrored in ELA classrooms. The stakeholders are teachers, as they experience constant pressure within their practices. Similarly, students encounter rigorous, results-based pressures. These dynamics contribute to feelings of powerlessness, thus reinforcing a formulaic model of ELA. The ELA curriculum has potential to create laboratories for critical discussion and active movement towards social change. This proposed research strategy of Surrealist-oriented pedagogies could enable students to experiment with social issues and develop senses of agency and voice that reflect awareness of contemporary society while simultaneously building their ELA skills.Keywords: arts-informed pedagogies, language arts, literature, surrealism
Procedia PDF Downloads 12617437 Pathfinders Career Guidance and Skill Development Program
Authors: Vinodd Nayak
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10th & 12th are the most crucial period in a student’s life. It is the time when he or she has to make vital career choices and get the relevant professional education. Unfortunately most students are not aware of the multitudes of career options available to them. This leads to affect our social fabric of the society with issues like unemployment, stress etc. We have planned a guidance program for the youth in Maharashtra state which has 4 components; creating awareness about different career options, proper guidance and motivation, counseling for parents, and information on financial aid for unemployed youth we are conducting skill development programs. Currently we are conducting programs under 4 categories Uneducated Youth: Skill Development programs for unemployed youth in construction field (Carpentry/Masoning/Wlder/Electrician/Tiling etc..) in association with L&T Construction Training Institute Educated Youth: Il&FS: Training and Job Placement in the field of Finance and Customer Service NIS Sparta: Training and Job Placement in the field of Sales and Marketing Apeejay Inst. of Hotel Management: Training and Job Placement in the field of hospitality industry Skill India: Training and Job Placement in the field of IT Results: The results were really overwhelming. We were able to cater to approx. 10,000 students a year and the list is growing. Earlier we were only catering to schools and colleges, now we have started receiving invitations from other community organizations to conduct such programs for their communities Implications for Social Work and Social Development practice: It is a high time that Social work organisations need to get into such work as this will enhance people to improve their financial condition. We always believed that it is better to teach a man to fish than feed him.Keywords: youth education, career guidance, skill development, parental guidance
Procedia PDF Downloads 33217436 Dispersion Rate of Spilled Oil in Water Column under Non-Breaking Water Waves
Authors: Hanifeh Imanian, Morteza Kolahdoozan
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The purpose of this study is to present a mathematical phrase for calculating the dispersion rate of spilled oil in water column under non-breaking waves. In this regard, a multiphase numerical model is applied for which waves and oil phase were computed concurrently, and accuracy of its hydraulic calculations have been proven. More than 200 various scenarios of oil spilling in wave waters were simulated using the multiphase numerical model and its outcome were collected in a database. The recorded results were investigated to identify the major parameters affected vertical oil dispersion and finally 6 parameters were identified as main independent factors. Furthermore, some statistical tests were conducted to identify any relationship between the dependent variable (dispersed oil mass in the water column) and independent variables (water wave specifications containing height, length and wave period and spilled oil characteristics including density, viscosity and spilled oil mass). Finally, a mathematical-statistical relationship is proposed to predict dispersed oil in marine waters. To verify the proposed relationship, a laboratory example available in the literature was selected. Oil mass rate penetrated in water body computed by statistical regression was in accordance with experimental data was predicted. On this occasion, it was necessary to verify the proposed mathematical phrase. In a selected laboratory case available in the literature, mass oil rate penetrated in water body computed by suggested regression. Results showed good agreement with experimental data. The validated mathematical-statistical phrase is a useful tool for oil dispersion prediction in oil spill events in marine areas.Keywords: dispersion, marine environment, mathematical-statistical relationship, oil spill
Procedia PDF Downloads 22817435 Isolation and Characterization of Bio-surfactant Producing Alcaligenes sp YLA1 and Its Diesel Degradation Potentials
Authors: Abdulrahman Abdulhamid Arabo, Raji Arabi Bamanga, Mujiburrahman Fadilu, Musa Abubakar, Fatima Abdullahi Shehu, Hafeez Muhammad Yakasai, Nasiru Abdullahi
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The aim of this study was to isolate and identify biosurfactant-producing and diesel alkanes degrading bacteria. For this reason, bacteria isolated from the diesel-contaminated site were screened for their potential to produce biosurfactants and degrade diesel alkanes. Primary selection of diesel degraders was carried out by using the conventional enrichment culture technique, where 12 bacterial strains were isolated based on their ability to grow on minimal media supplemented with diesel as the sole carbon source, which was followed by qualitative screening methods for potential biosurfactant production. Isolate B11 was the only candidate that showed positive signs for drop collapse, foaming, hemolytic test, oil displacement of more than 22 ± 0.05 mm, and emulsification (E24) of 14 ± 0.30%. The effect of various culture parameters (incubation time, diesel concentration, nitrogen source, pH and temperature) on the biodegradation of diesel was evaluated. The optimum incubation time was confirmed to be 120 days for isolate B11, and the optimum PH was confirmed as 8.0 for the isolate; similarly, the optimum temperature was confirmed as 35oC. In addition, diesel oil was used as the sole carbon source for the isolates. The favorable diesel concentration was 12.5 % (v/v) for the isolate. The isolate has shown degradative ability towards Tridecane (C13), dodecane, 2, 6, 10-trimethyl- (C15), Tetradecane (C14), 2,6,10-Trimethyltridecane (C16), Pentadecane (C15). It degraded between 0.27% - 9.65% of individual diesel oil alkanes. The strain has exhibited the potential of degrading diesel oil n-alkanes and was identified as Alcaligenes species strain B11 (MZ027604) using the 16S rRNA. Sequencing.Keywords: diesel oil, biosurfactant, Alcaligenes sp, biodegradation
Procedia PDF Downloads 9817434 Single Fly Over as a Solution to Congestion of Intersection Junction: Case Study of Jalan Jatingaleh Semarang
Authors: Rachmat Mudiyono, Siti Sumiati
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In the next few years, traffic will happen most of the time. This was triggered by the growing rate of vehicles againts the road capacity which is not balance. All the time the congestion in the city of Semarang has been occured at peak hours. Congestion also occured in between Teuku Umar and Setia Budi road Jatingaleh because of a plot intersection (Kesatrian intersection, PLN intersection and Jatingaleh intersection) with the Toll Road. Jatingaleh is located in the southern city of Semarang which is a central meeting point between the upper and lower Semarang where the vehicle flows in through a combination of local current and regional traffic, and the flow of vehicles coming in and out from highway. The main cause of the problems that occurred in the area of Jatingaleh is due to the numbers of vehicles movement that occurs at the intersections. With the above issues, it is necessary to analyse the existing conditions and look into some solutions. Before carrying out an analysis of field surveys at peak hours for example morning (06:00 to 08:00 am) and for the afternoon (04:00 to 06:00 pm)should be conducted, then the number of vehicles is counted manually with “short-breakcounting” according to types of vehicles. From the analysis we found that the degree of saturation (DS) is 1.61 between Teuku Umar and Setia Budi road during the morning peak hours and 1.56 during the afternoon peak hours. This means that the capacity of the existing road is no longer able to accommodate the traffic flow. One of the solutions for the congestion that occurs at the intersection of Jatingaleh is to apply the efficiency of the intersection that is not in a plot with a Fly over, Underpass and the combination of Fly Over-Underpass. Base on the flow reduction calculation with 3 comparative modeling it shows that the Fly Over is the most technically efficient to be applied in this research.Keywords: single fly over, congestion, intersection, interchange
Procedia PDF Downloads 38517433 Influence of Geologic and Geotechnical Dataset Resolution on Regional Liquefaction Assessment of the Lower Wairau Plains
Authors: Omer Altaf, Liam Wotherspoon, Rolando Orense
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The Wairau Plains are located in the northeast of the South Island of New Zealand, with alluvial deposits of fine-grained silts and sands combined with low-lying topography suggesting the presence of liquefiable deposits over significant portions of the region. Liquefaction manifestations were observed in past earthquakes, including the 1848 Marlborough and 1855 Wairarapa earthquakes, and more recently during the 2013 Lake Grassmere and 2016 Kaikōura earthquakes. Therefore, a good understanding of the deposits that may be susceptible to liquefaction is important for land use planning in the region and to allow developers and asset owners to appropriately address their risk. For this purpose, multiple approaches have been employed to develop regional-scale maps showing the liquefaction vulnerability categories for the region. After applying semi-qualitative criteria linked to geologic age and deposit type, the higher resolution surface mapping of geomorphologic characteristics encompassing the Wairau River and the Opaoa River was used for screening. A detailed basin geologic model developed for groundwater modelling was analysed to provide a higher level of resolution than the surface-geology based classification. This is used to identify the thickness of near-surface gravel deposits, providing an improved understanding of the presence or lack of potentially non-liquefiable crust deposits. This paper describes the methodology adopted for this project and focuses on the influence of geomorphic characteristics and analysis of the detailed geologic basin model on the liquefaction classification of the Lower Wairau Plains.Keywords: liquefaction, earthquake, cone penetration test, mapping, liquefaction-induced damage
Procedia PDF Downloads 16917432 Reversible Information Hitting in Encrypted JPEG Bitstream by LSB Based on Inherent Algorithm
Authors: Vaibhav Barve
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Reversible information hiding has drawn a lot of interest as of late. Being reversible, we can restore unique computerized data totally. It is a plan where mystery data is put away in digital media like image, video, audio to maintain a strategic distance from unapproved access and security reason. By and large JPEG bit stream is utilized to store this key data, first JPEG bit stream is encrypted into all around sorted out structure and then this secret information or key data is implanted into this encrypted region by marginally changing the JPEG bit stream. Valuable pixels suitable for information implanting are computed and as indicated by this key subtle elements are implanted. In our proposed framework we are utilizing RC4 algorithm for encrypting JPEG bit stream. Encryption key is acknowledged by framework user which, likewise, will be used at the time of decryption. We are executing enhanced least significant bit supplanting steganography by utilizing genetic algorithm. At first, the quantity of bits that must be installed in a guaranteed coefficient is versatile. By utilizing proper parameters, we can get high capacity while ensuring high security. We are utilizing logistic map for shuffling of bits and utilization GA (Genetic Algorithm) to find right parameters for the logistic map. Information embedding key is utilized at the time of information embedding. By utilizing precise picture encryption and information embedding key, the beneficiary can, without much of a stretch, concentrate the incorporated secure data and totally recoup the first picture and also the original secret information. At the point when the embedding key is truant, the first picture can be recouped pretty nearly with sufficient quality without getting the embedding key of interest.Keywords: data embedding, decryption, encryption, reversible data hiding, steganography
Procedia PDF Downloads 28317431 Improving Fault Tolerance and Load Balancing in Heterogeneous Grid Computing Using Fractal Transform
Authors: Saad M. Darwish, Adel A. El-Zoghabi, Moustafa F. Ashry
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The popularity of the Internet and the availability of powerful computers and high-speed networks as low-cost commodity components are changing the way we use computers today. These technical opportunities have led to the possibility of using geographically distributed and multi-owner resources to solve large-scale problems in science, engineering, and commerce. Recent research on these topics has led to the emergence of a new paradigm known as Grid computing. To achieve the promising potentials of tremendous distributed resources, effective and efficient load balancing algorithms are fundamentally important. Unfortunately, load balancing algorithms in traditional parallel and distributed systems, which usually run on homogeneous and dedicated resources, cannot work well in the new circumstances. In this paper, the concept of a fast fractal transform in heterogeneous grid computing based on R-tree and the domain-range entropy is proposed to improve fault tolerance and load balancing algorithm by improve connectivity, communication delay, network bandwidth, resource availability, and resource unpredictability. A novel two-dimension figure of merit is suggested to describe the network effects on load balance and fault tolerance estimation. Fault tolerance is enhanced by adaptively decrease replication time and message cost while load balance is enhanced by adaptively decrease mean job response time. Experimental results show that the proposed method yields superior performance over other methods.Keywords: Grid computing, load balancing, fault tolerance, R-tree, heterogeneous systems
Procedia PDF Downloads 48117430 The Study of Internship Performances: Comparison of Information Technology Interns towards Students’ Types and Background Profiles
Authors: Shutchapol Chopvitayakun
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Internship program is a compulsory course of many undergraduate programs in Thailand. It gives opportunities to a lot of senior students as interns to practice their working skills in the real organizations and also gives chances for interns to face real-world working problems. Interns also learn how to solve those problems by direct and indirect experiences. This program in many schools is a well-structured course with a contract or agreement made with real business organizations. Moreover, this program also offers opportunities for interns to get jobs after completing it from where the internship program takes place. Interns also learn how to work as a team and how to associate with other colleagues, trainers, and superiors of each organization in term of social hierarchy, self-responsibility, and self-disciplinary. This research focuses on senior students of Suan Sunandha Rajabhat University, Thailand whose studying major is information technology program. They practiced their working skills or took internship programs in the real business sector or real operating organizations in 2015-2016. Interns are categorized in to two types: normal program and special program. For special program, students study in weekday evening from Monday to Friday or Weekend and most of them work full-time or part-time job. For normal program, students study in weekday working hours and most of them do not work. The differences of these characters and the outcomes of internship performance were studied and analyzed in this research. This work applied some statistical analytics to find out whether the internship performance of each intern type has different performances statistically or not.Keywords: internship, intern, senior student, information technology program
Procedia PDF Downloads 25717429 Exploring Influence Range of Tainan City Using Electronic Toll Collection Big Data
Authors: Chen Chou, Feng-Tyan Lin
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Big Data has been attracted a lot of attentions in many fields for analyzing research issues based on a large number of maternal data. Electronic Toll Collection (ETC) is one of Intelligent Transportation System (ITS) applications in Taiwan, used to record starting point, end point, distance and travel time of vehicle on the national freeway. This study, taking advantage of ETC big data, combined with urban planning theory, attempts to explore various phenomena of inter-city transportation activities. ETC, one of government's open data, is numerous, complete and quick-update. One may recall that living area has been delimited with location, population, area and subjective consciousness. However, these factors cannot appropriately reflect what people’s movement path is in daily life. In this study, the concept of "Living Area" is replaced by "Influence Range" to show dynamic and variation with time and purposes of activities. This study uses data mining with Python and Excel, and visualizes the number of trips with GIS to explore influence range of Tainan city and the purpose of trips, and discuss living area delimited in current. It dialogues between the concepts of "Central Place Theory" and "Living Area", presents the new point of view, integrates the application of big data, urban planning and transportation. The finding will be valuable for resource allocation and land apportionment of spatial planning.Keywords: Big Data, ITS, influence range, living area, central place theory, visualization
Procedia PDF Downloads 27217428 A Combined CFD Simulation of Plateau Borders including Films and Transitional Areas of Liquid Foams
Authors: Abdolhamid Anazadehsayed, Jamal Naser
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An integrated computational fluid dynamics model is developed for a combined simulation of Plateau borders, films, and transitional areas between the film and the Plateau borders to reduce the simplifications and shortcomings of available models for foam drainage in micro-scale. Additionally, the counter-flow related to the Marangoni effect in the transitional area is investigated. The results of this combined model show the contribution of the films, the exterior Plateau borders, and Marangoni flow in the drainage process more accurately since the inter-influence of foam's elements is included in this study. The exterior Plateau borders flow rate can be four times larger than the interior ones. The exterior bubbles can be more prominent in the drainage process in cases where the number of the exterior Plateau borders increases due to the geometry of container. The ratio of the Marangoni counter-flow to the Plateau border flow increases drastically with an increase in the mobility of air-liquid interface. However, the exterior bubbles follow the same trend with much less intensity since typically, the flow is less dependent on the interface of air-liquid in the exterior bubbles. Moreover, the Marangoni counter-flow in a near-wall transition area is less important than an internal one. The influence of air-liquid interface mobility on the average velocity of interior foams is attained with more accuracy with more realistic boundary condition. Then it has been compared with other numerical and analytical results. The contribution of films in the drainage is significant for the mobile foams as the velocity of flow in the film has the same order of magnitude as the velocity in the Plateau border. Nevertheless, for foams with rigid interfaces, film's contribution in foam drainage is insignificant, particularly for the films near the wall of the container.Keywords: foam, plateau border, film, Marangoni, CFD, bubble
Procedia PDF Downloads 33917427 Molecular Dynamics Simulations on Richtmyer-Meshkov Instability of Li-H2 Interface at Ultra High-Speed Shock Loads
Authors: Weirong Wang, Shenghong Huang, Xisheng Luo, Zhenyu Li
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Material mixing process and related dynamic issues at extreme compressing conditions have gained more and more concerns in last ten years because of the engineering appealings in inertial confinement fusion (ICF) and hypervelocity aircraft developments. However, there lacks models and methods that can handle fully coupled turbulent material mixing and complex fluid evolution under conditions of high energy density regime up to now. In aspects of macro hydrodynamics, three numerical methods such as direct numerical simulation (DNS), large eddy simulation (LES) and Reynolds-averaged Navier–Stokes equations (RANS) has obtained relative acceptable consensus under the conditions of low energy density regime. However, under the conditions of high energy density regime, they can not be applied directly due to occurrence of dissociation, ionization, dramatic change of equation of state, thermodynamic properties etc., which may make the governing equations invalid in some coupled situations. However, in view of micro/meso scale regime, the methods based on Molecular Dynamics (MD) as well as Monte Carlo (MC) model are proved to be promising and effective ways to investigate such issues. In this study, both classical MD and first-principle based electron force field MD (eFF-MD) methods are applied to investigate Richtmyer-Meshkov Instability of metal Lithium and gas Hydrogen (Li-H2) interface mixing at different shock loading speed ranging from 3 km/s to 30 km/s. It is found that: 1) Classical MD method based on predefined potential functions has some limits in application to extreme conditions, since it cannot simulate the ionization process and its potential functions are not suitable to all conditions, while the eFF-MD method can correctly simulate the ionization process due to its ‘ab initio’ feature; 2) Due to computational cost, the eFF-MD results are also influenced by simulation domain dimensions, boundary conditions and relaxation time choices, etc., in computations. Series of tests have been conducted to determine the optimized parameters. 3) Ionization induced by strong shock compression has important effects on Li-H2 interface evolutions of RMI, indicating a new micromechanism of RMI under conditions of high energy density regime.Keywords: first-principle, ionization, molecular dynamics, material mixture, Richtmyer-Meshkov instability
Procedia PDF Downloads 22317426 Metacognitive Processing in Early Readers: The Role of Metacognition in Monitoring Linguistic and Non-Linguistic Performance and Regulating Students' Learning
Authors: Ioanna Taouki, Marie Lallier, David Soto
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Metacognition refers to the capacity to reflect upon our own cognitive processes. Although there is an ongoing discussion in the literature on the role of metacognition in learning and academic achievement, little is known about its neurodevelopmental trajectories in early childhood, when children begin to receive formal education in reading. Here, we evaluate the metacognitive ability, estimated under a recently developed Signal Detection Theory model, of a cohort of children aged between 6 and 7 (N=60), who performed three two-alternative-forced-choice tasks (two linguistic: lexical decision task, visual attention span task, and one non-linguistic: emotion recognition task) including trial-by-trial confidence judgements. Our study has three aims. First, we investigated how metacognitive ability (i.e., how confidence ratings track accuracy in the task) relates to performance in general standardized tasks related to students' reading and general cognitive abilities using Spearman's and Bayesian correlation analysis. Second, we assessed whether or not young children recruit common mechanisms supporting metacognition across the different task domains or whether there is evidence for domain-specific metacognition at this early stage of development. This was done by examining correlations in metacognitive measures across different task domains and evaluating cross-task covariance by applying a hierarchical Bayesian model. Third, using robust linear regression and Bayesian regression models, we assessed whether metacognitive ability in this early stage is related to the longitudinal learning of children in a linguistic and a non-linguistic task. Notably, we did not observe any association between students’ reading skills and metacognitive processing in this early stage of reading acquisition. Some evidence consistent with domain-general metacognition was found, with significant positive correlations between metacognitive efficiency between lexical and emotion recognition tasks and substantial covariance indicated by the Bayesian model. However, no reliable correlations were found between metacognitive performance in the visual attention span and the remaining tasks. Remarkably, metacognitive ability significantly predicted children's learning in linguistic and non-linguistic domains a year later. These results suggest that metacognitive skill may be dissociated to some extent from general (i.e., language and attention) abilities and further stress the importance of creating educational programs that foster students’ metacognitive ability as a tool for long term learning. More research is crucial to understand whether these programs can enhance metacognitive ability as a transferable skill across distinct domains or whether unique domains should be targeted separately.Keywords: confidence ratings, development, metacognitive efficiency, reading acquisition
Procedia PDF Downloads 14417425 Morphological and Molecular Evaluation of Dengue Virus Serotype 3 Infection in BALB/c Mice Lungs
Authors: Gabriela C. Caldas, Fernanda C. Jacome, Arthur da C. Rasinhas, Ortrud M. Barth, Flavia B. dos Santos, Priscila C. G. Nunes, Yuli R. M. de Souza, Pedro Paulo de A. Manso, Marcelo P. Machado, Debora F. Barreto-Vieira
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The establishment of animal models for studies of DENV infections has been challenging, since circulating epidemic viruses do not naturally infect nonhuman species. Such studies are of great relevance to the various areas of dengue research, including immunopathogenesis, drug development and vaccines. In this scenario, the main objective of this study is to verify possible morphological changes, as well as the presence of antigens and viral RNA in lung samples from BALB/c mice experimentally infected with an epidemic and non-neuroadapted DENV-3 strain. Male BALB/c mice, 2 months old, were inoculated with DENV-3 by intravenous route. After 72 hours of infection, the animals were euthanized and the lungs were collected. Part of the samples was processed by standard technique for analysis by light and transmission electronic microscopies and another part was processed for real-time PCR analysis. Morphological analyzes of lungs from uninfected mice showed preserved tissue areas. In mice infected with DENV-3, the analyzes revealed interalveolar septum thickening with presence of inflammatory infiltrate, foci of alveolar atelectasis and hyperventilation, bleeding foci in the interalveolar septum and bronchioles, peripheral capillary congestion, accumulation of fluid in the blood capillary, signs of interstitial cell necrosis presence of platelets and mononuclear inflammatory cells circulating in the capillaries and/or adhered to the endothelium. In addition, activation of endothelial cells, platelets, mononuclear inflammatory cell and neutrophil-type polymorphonuclear inflammatory cell evidenced by the emission of cytoplasmic membrane prolongation was observed. DEN-like particles were seen in the cytoplasm of endothelial cells. The viral genome was recovered from 3 in 12 lung samples. These results demonstrate that the BALB / c mouse represents a suitable model for the study of the histopathological changes induced by DENV infection in the lung, with tissue alterations similar to those observed in human cases of DEN.Keywords: BALB/c mice, dengue, histopathology, lung, ultrastructure
Procedia PDF Downloads 24917424 High Cycle Fatigue Analysis of a Lower Hopper Knuckle Connection of a Large Bulk Carrier under Dynamic Loading
Authors: Vaso K. Kapnopoulou, Piero Caridis
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The fatigue of ship structural details is of major concern in the maritime industry as it can generate fracture issues that may compromise structural integrity. In the present study, a fatigue analysis of the lower hopper knuckle connection of a bulk carrier was conducted using the Finite Element Method by means of ABAQUS/CAE software. The fatigue life was calculated using Miner’s Rule and the long-term distribution of stress range by the use of the two-parameter Weibull distribution. The cumulative damage ratio was estimated using the fatigue damage resulting from the stress range occurring at each load condition. For this purpose, a cargo hold model was first generated, which extends over the length of two holds (the mid-hold and half of each of the adjacent holds) and transversely over the full breadth of the hull girder. Following that, a submodel of the area of interest was extracted in order to calculate the hot spot stress of the connection and to estimate the fatigue life of the structural detail. Two hot spot locations were identified; one at the top layer of the inner bottom plate and one at the top layer of the hopper plate. The IACS Common Structural Rules (CSR) require that specific dynamic load cases for each loading condition are assessed. Following this, the dynamic load case that causes the highest stress range at each loading condition should be used in the fatigue analysis for the calculation of the cumulative fatigue damage ratio. Each load case has a different effect on ship hull response. Of main concern, when assessing the fatigue strength of the lower hopper knuckle connection, was the determination of the maximum, i.e. the critical value of the stress range, which acts in a direction normal to the weld toe line. This acts in the transverse direction, that is, perpendicularly to the ship's centerline axis. The load cases were explored both theoretically and numerically in order to establish the one that causes the highest damage to the location examined. The most severe one was identified to be the load case induced by beam sea condition where the encountered wave comes from the starboard. At the level of the cargo hold model, the model was assumed to be simply supported at its ends. A coarse mesh was generated in order to represent the overall stiffness of the structure. The elements employed were quadrilateral shell elements, each having four integration points. A linear elastic analysis was performed because linear elastic material behavior can be presumed, since only localized yielding is allowed by most design codes. At the submodel level, the displacements of the analysis of the cargo hold model to the outer region nodes of the submodel acted as boundary conditions and applied loading for the submodel. In order to calculate the hot spot stress at the hot spot locations, a very fine mesh zone was generated and used. The fatigue life of the detail was found to be 16.4 years which is lower than the design fatigue life of the structure (25 years), making this location vulnerable to fatigue fracture issues. Moreover, the loading conditions that induce the most damage to the location were found to be the various ballasting conditions.Keywords: dynamic load cases, finite element method, high cycle fatigue, lower hopper knuckle
Procedia PDF Downloads 41317423 The Role of Physical Education and Fitness for Active Ageing
Authors: A. Lakshya
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The main aim of this paper is to interpret physical education for children from 5 to 18 years. Schools have the ability to promote positive mental health by developing physical education, which helps to build individual growth, goal setting, decision making, helps in muscular development, self-discipline, stresses relief, leadership qualities that can arise with new skills, prosocial behavior and problem-solving skills. But mostly the children at these early ages ought to hold the disorders as heart attack, diabetes and obesity disorders may increase in large number. The data of P.E has got a very least place, where children are with feeble minds and they acquired a state of inactiveness. Globally, 81% of adolescents aged 11-18 years were insufficiently physically active in the year 2016. Adolescent girls were less active than boys, with the percentage of 85% vs. 78% as well. A recent study of California schools found that students are sedentary most of the time during PE classes, with just four minutes of every half-hour spent in vigorous physical activity. Additionally, active PE time decreases with larger class sizes. Students in classes with more than forty-five students are half as active as students in smaller class sizes. The children in adolescence age they acquire more creative ideas hence they create new hairstyles, cooking styles and dressing styles. Instead, all the children are engaging themselves to TV (television) and video games. The development of physical quality not only improves students ’ physical fitness but is also conducive to the psychological development of the students. Physical education teaching should pay more attention to the training of physical quality in the future.Keywords: physical education, prosocial behavior, leadership, goal setting
Procedia PDF Downloads 13217422 Comprehensive Approach to Control Virus Infection and Energy Consumption in An Occupant Classroom
Authors: SeyedKeivan Nateghi, Jan Kaczmarczyk
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People nowadays spend most of their time in buildings. Accordingly, maintaining a good quality of indoor air is very important. New universal matters related to the prevalence of Covid-19 also highlight the importance of indoor air conditioning in reducing the risk of virus infection. Cooling and Heating of a house will provide a suitable zone of air temperature for residents. One of the significant factors in energy demand is energy consumption in the building. In general, building divisions compose more than 30% of the world's fundamental energy requirement. As energy demand increased, greenhouse effects emerged that caused global warming. Regardless of the environmental damage to the ecosystem, it can spread infectious diseases such as malaria, cholera, or dengue to many other parts of the world. With the advent of the Covid-19 phenomenon, the previous instructions to reduce energy consumption are no longer responsive because they increase the risk of virus infection among people in the room. Two problems of high energy consumption and coronavirus infection are opposite. A classroom with 30 students and one teacher in Katowice, Poland, considered controlling two objectives simultaneal. The probability of transmission of the disease is calculated from the carbon dioxide concentration of people. Also, in a certain period, the amount of energy consumption is estimated by EnergyPlus. The effect of three parameters of number, angle, and time or schedule of opening windows on the probability of infection transmission and energy consumption of the class were investigated. Parameters were examined widely to determine the best possible condition for simultaneous control of infection spread and energy consumption. The number of opening windows is discrete (0,3), and two other parameters are continuous (0,180) and (8 AM, 2 PM). Preliminary results show that changes in the number, angle, and timing of window openings significantly impact the likelihood of virus transmission and class energy consumption. The greater the number, tilt, and timing of window openings, the less likely the student will transmit the virus. But energy consumption is increasing. When all the windows were closed at all hours of the class, the energy consumption for the first day of January was only 0.2 megajoules. In comparison, the probability of transmitting the virus per person in the classroom is more than 45%. But when all windows were open at maximum angles during class, the chance of transmitting the infection was reduced to 0.35%. But the energy consumption will be 36 megajoules. Therefore, school classrooms need an optimal schedule to control both functions. In this article, we will present a suitable plan for the classroom with natural ventilation through windows to control energy consumption and the possibility of infection transmission at the same time.Keywords: Covid-19, energy consumption, building, carbon dioxide, energyplus
Procedia PDF Downloads 9317421 Increases in Serum Erythropoietin Hormone in Recreational Breath-Hold Divers Following a Series of Repeated Apnoeas: Apnoea beyond Freediving
Authors: Antonis Elia, Theo Loizou, Gladys Onambele-Pearson, Matthew Barlow, Georgina Stebbings
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Hypoxic conditions have been reported to enhance red blood cell production in both acclimatised low-landers and altitude adapted populations. This process is mediated by the erythropoietin hormone, which is released predominantly by the hypoxic kidney. A higher haemoglobin concentration was previously reported in elite breath-hold divers when compared to elite-skiers and untrained individuals. Therefore, the present study aimed to investigate whether apnoea induced hypoxia could induce a significant increase in serum erythropoietin concentration in recreational breath-hold divers which would provide an explanation to the higher haemoglobin levels observed in elite breath-hold divers. Identifying whether apnoea induced hypoxia induces a significant increase in serum erythropoietin might suggest that apnoea can be used as an alternative acclimatisation method to high altitude exposure. Seven healthy, recreational male breath-hold divers performed two sets of five 180 second breath-holds with a ten-minute supine rest between each set and a two-minute seated rest between each apnoea. During each breath-hold, participant’s heart rate and peripheral oxygen saturation levels were recorded every subsequent 10 seconds until the end of the 180 second breath-hold. After each 180 second breath-hold a capillary blood sample was collected from the finger to identify circulating haemoglobin levels. Following completion of the apnoeic protocol, three blood samples were collected at 30, 90 and 180 minutes to measure circulating erythropoietin levels. A significant interaction between erythropoietin and time was observed (F(3,18)= 4.72, p < 0.001), with significant increases in erythropoietin evident at 30 (t(6)= -5.035, p < 0.0590 (t(6)= -6.162, p < 0.05) and 180 (t(6)= - 7.232, p < 0.001) minutes post the last apnoea when compared to baseline. Corresponding average increases when compared to baseline were 16% at 30, 23% at 90 and 40% at 180 minutes post the last apnoea. A significant interaction between haemoglobin and time was observed (F(78,84)= 20.814, p < 0.001), with significant increases in haemoglobin evident at the fifth (t(29)= -1.124, p < 0.001), ninth (t(29)= -1.357, p < 0.001) and tenth (t(29)= -1.211, p < 0.05) apnoeas when compared to baseline. A significant interaction between peripheral oxygen saturation and time was observed (F(10,60)= 408.23, p < 0.001). The present study demonstrates that a series of ten 180 second breath-holds is sufficient to induce a significant increase in the circulating erythropoietin concentration of recreational breath hold divers. These observations may suggest that apnoea induced hypoxia may be used as an alternative acclimatisation method to high altitude exposure.Keywords: apnoea, breath-holding, diving reflex, erythropoietin, haemoglobin
Procedia PDF Downloads 17617420 A Case Study on the Seismic Performance Assessment of the High-Rise Setback Tower Under Multiple Support Excitations on the Basis of TBI Guidelines
Authors: Kamyar Kildashti, Rasoul Mirghaderi
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This paper describes the three-dimensional seismic performance assessment of a high-rise steel moment-frame setback tower, designed and detailed per the 2010 ASCE7, under multiple support excitations. The vulnerability analyses are conducted based on nonlinear history analyses under a set of multi-directional strong ground motion records which are scaled to design-based site-specific spectrum in accordance with ASCE41-13. Spatial variation of input motions between far distant supports of each part of the tower is considered by defining time lag. Plastic hinge monotonic and cyclic behavior for prequalified steel connections, panel zones, as well as steel columns is obtained from predefined values presented in TBI Guidelines, PEER/ATC72 and FEMA P440A to include stiffness and strength degradation. Inter-story drift ratios, residual drift ratios, as well as plastic hinge rotation demands under multiple support excitations, are compared to those obtained from uniform support excitations. Performance objectives based on acceptance criteria declared by TBI Guidelines are compared between uniform and multiple support excitations. The results demonstrate that input motion discrepancy results in detrimental effects on the local and global response of the tower.Keywords: high-rise building, nonlinear time history analysis, multiple support excitation, performance-based design
Procedia PDF Downloads 28117419 Boiler Ash as a Reducer of Formaldehyde Emission in Medium-Density Fiberboard
Authors: Alexsandro Bayestorff da Cunha, Dpebora Caline de Mello, Camila Alves Corrêa
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In the production of fiberboards, an adhesive based on urea-formaldehyde resin is used, which has the advantages of low cost, homogeneity of distribution, solubility in water, high reactivity in an acid medium, and high adhesion to wood. On the other hand, as a disadvantage, there is low resistance to humidity and the release of formaldehyde. The objective of the study was to determine the viability of adding industrial boiler ash to the urea formaldehyde-based adhesive for the production of medium-density fiberboard. The raw material used was composed of Pinus spp fibers, urea-formaldehyde resin, paraffin emulsion, ammonium sulfate, and boiler ash. The experimental plan, consisting of 8 treatments, was completely randomized with a factorial arrangement, with 0%, 1%, 3%, and 5% ash added to the adhesive, with and without the application of a catalyst. In each treatment, 4 panels were produced with density of 750 kg.m⁻³, dimensions of 40 x 40 x 1,5 cm, 12% urea formaldehyde resin, 1% paraffin emulsion and hot pressing at a temperature of 180ºC, the pressure of 40 kgf/cm⁻² for a time of 10 minutes. The different compositions of the adhesive were characterized in terms of viscosity, pH, gel time and solids, and the panels by physical and mechanical properties, in addition to evaluation using the IMAL DPX300 X-ray densitometer and formaldehyde emission by the perforator method. The results showed a significant reduction of all adhesive properties with the use of the catalyst, regardless of the treatment; while the percentage increase of ashes provided an increase in the average values of viscosity, gel time, and solids and a reduction in pH for the panels with a catalyst; for panels without catalyst, the behavior was the opposite, with the exception of solids. For the physical properties, the results of the variables of density, compaction ratio, and thickness were equivalent and in accordance with the standard, while the moisture content was significantly reduced with the use of the catalyst but without the influence of the percentage of ash. The density profile for all treatments was characteristic of medium-density fiberboard, with more compacted and dense surfaces when compared to the central layer. For thickness, the swelling was not influenced by the catalyst and the use of ash, presenting average values within the normalized parameters. For mechanical properties, the influence of ashes on the adhesive was negatively observed in the modulus of rupture from 1% and in the traction test from 3%; however, only this last property, in the percentages of 3% and 5%, were below the minimum limit of the norm. The use of catalyst and ashes with percentages of 3% and 5% reduced the formaldehyde emission of the panels; however, only the panels that used adhesive with catalyst presented emissions below 8mg of formaldehyde / 100g of the panel. In this way, it can be said that boiler ash can be added to the adhesive with a catalyst without impairing the technological properties by up to 1%.Keywords: reconstituted wood panels, formaldehyde emission, technological properties of panels, perforator
Procedia PDF Downloads 6217418 Designing a Pre-Assessment Tool to Support the Achievement of Green Building Certifications
Authors: Jisun Mo, Paola Boarin
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The impact of common buildings on climate and environment has prompted people to get involved in the green building standards aimed at implementing rating tools or certifications. Thus, green building rating systems were introduced to the construction industry, and the demand for certified green buildings has increased gradually and succeeded considerably in enhancing people’s environmental awareness. However, the existing certification process has been unsatisfactory in attracting stakeholders and/or professionals who are actively engaged in adopting a rating system. It is because they have faced recurring barriers regarding limited information in understanding the rating process, time-consuming procedures and higher costs, which have a direct influence on pursuing green building rating systems. To promote the achievement of green building certifications within the building industry more successfully, this paper aims at designing a Pre-Assessment Tool (PAT) framework that can help stakeholders and/or professionals engaged in the construction industry to clarify their basic knowledge, timeframe and extra costs needed to activate a green building certification. First, taking the first steps towards the rating tool seems to be complicated because of upfront commitment to understanding the overall rating procedure is required. This conceptual PAT framework can increase basic knowledge of the rating tool and the certification process, mainly in terms of all resources or information of each credit requirements. Second, the assessment process of rating tools is generally known as a “lengthy and time-consuming system”, contributing to unenthusiastic reactions concerning green building projects. The proposed framework can predict the timeframe needed to identify how long it will take for a green project to process each credit requirement and the documentation required from the beginning of the certification process to final approval. Finally, most people often have the initial perception that pursuing green building certification costs more than constructing a non-green building, which makes it more difficult to execute rating tools. To overcome this issue, this PAT will help users to estimate the extra expenses such as certification fees and third-party contributions based on the track of the amount of time it takes to implement the rating tool throughout all the related stages. Also, it can prevent unexpected or hidden costs occurring in the process of assessment. Therefore, this proposed PAT framework can be recommended as an effective method to support the decision-making of inexperienced users and play an important role in promoting green building certification.Keywords: green building rating tools, Pre-Occupancy Evaluation (PrOE), client’s decision-making, certification
Procedia PDF Downloads 24117417 Implementation of Lean Tools (Value Stream Mapping and ECRS) in an Oil Refinery
Authors: Ronita Singh, Yaman Pattanaik, Soham Lalwala
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In today’s highly competitive business environment, every organization is striving towards lean manufacturing systems to achieve lower Production Lead Times, lower costs, less inventory and overall improvement in supply chains efficiency. Based on the similar idea, this paper presents the practical application of Value Stream Mapping (VSM) tool and ECRS (Eliminate, Combine, Reduce, and Simplify) technique in the receipt section of the material management center of an oil refinery. A value stream is an assortment of all actions (value added as well as non-value added) that are required to bring a product through the essential flows, starting with raw material and ending with the customer. For drawing current state value stream mapping, all relevant data of the receipt cycle has been collected and analyzed. Then analysis of current state map has been done for determining the type and quantum of waste at every stage which helped in ascertaining as to how far the warehouse is from the concept of lean manufacturing. From the results achieved by current VSM, it was observed that the two processes- Preparation of GRN (Goods Receipt Number) and Preparation of UD (Usage Decision) are both bottle neck operations and have higher cycle time. This root cause analysis of various types of waste helped in designing a strategy for step-wise implementation of lean tools. The future state thus created a lean flow of materials at the warehouse center, reducing the lead time of the receipt cycle from 11 days to 7 days and increasing overall efficiency by 27.27%.Keywords: current VSM, ECRS, future VSM, receipt cycle, supply chain, VSM
Procedia PDF Downloads 30117416 Understanding and Explaining Urban Resilience and Vulnerability: A Framework for Analyzing the Complex Adaptive Nature of Cities
Authors: Richard Wolfel, Amy Richmond
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Urban resilience and vulnerability are critical concepts in the modern city due to the increased sociocultural, political, economic, demographic, and environmental stressors that influence current urban dynamics. Urban scholars need help explaining urban resilience and vulnerability. First, cities are dominated by people, which is challenging to model, both from an explanatory and a predictive perspective. Second, urban regions are highly recursive in nature, meaning they not only influence human action, but the structures of cities are constantly changing due to human actions. As a result, explanatory frameworks must continuously evolve as humans influence and are influenced by the urban environment in which they operate. Finally, modern cities have populations, sociocultural characteristics, economic flows, and environmental impacts on order of magnitude well beyond the cities of the past. As a result, the frameworks that seek to explain the various functions of a city that influence urban resilience and vulnerability must address the complex adaptive nature of cities and the interaction of many distinct factors that influence resilience and vulnerability in the city. This project develops a taxonomy and framework for organizing and explaining urban vulnerability. The framework is built on a well-established political development model that includes six critical classes of urban dynamics: political presence, political legitimacy, political participation, identity, production, and allocation. In addition, the framework explores how environmental security and technology influence and are influenced by the six elements of political development. The framework aims to identify key tipping points in society that act as influential agents of urban vulnerability in a region. This will help analysts and scholars predict and explain the influence of both physical and human geographical stressors in a dense urban area.Keywords: urban resilience, vulnerability, sociocultural stressors, political stressors
Procedia PDF Downloads 10817415 Influence of Instructional Supervision on Teachers Performance in Secondary Schools in Otukpo LGA of Benue State
Authors: A. Aloga, A. S. Aloga
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The study examined the influence of instructional supervision on teachers’ performance in secondary schools in Otukpo LGA of Benue State. The study was guided by four research questions and four hypotheses. The study employed a descriptive research design. The population of the study comprised of 579 teachers in 26 public secondary schools out of which 236 respondents were sampled and used as the studied population. The instrument used for data collection was a structured questionnaire, titled ‘Instructional Supervision and Teachers Performance Questionnaire (ISTPQ)’ The data was analyzed using descriptive statistics of mean and standard deviation to answer the research questions. And Chi-Square Statistics was used to test the hypotheses at 0.05 level of significance. The study found that instructional supervision has a significant influence on teachers’ lesson planning, effective teaching, teachers’ class attendance and teachers’ classroom management. The study concluded that instructional supervision influences teachers’ performance. It was recommended that; instructional supervisors should always give useful suggestions as regards the best instructional practices needed by teachers in enhancing lesson planning. The government should recruit more trained and qualified instructional supervisors to be able to meet the intending demands of instructional supervision. This will relieve the existing few qualified instructional supervisors from work overload which may result to ineffectiveness and poor performance of their duties. Conferences and seminars should be organized for instructional supervisors from time to time to cater for the professional assistance needed by teachers. The state government should always provide adequate funding for these conferences and seminars since it provides an avenue for acquiring new knowledge in educational development by teachers among others.Keywords: influence, instructional supervision, teachers’ performance, secondary schools
Procedia PDF Downloads 13417414 Secure Optimized Ingress Filtering in Future Internet Communication
Authors: Bander Alzahrani, Mohammed Alreshoodi
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Information-centric networking (ICN) using architectures such as the Publish-Subscribe Internet Technology (PURSUIT) has been proposed as a new networking model that aims at replacing the current used end-centric networking model of the Internet. This emerged model focuses on what is being exchanged rather than which network entities are exchanging information, which gives the control plane functions such as routing and host location the ability to be specified according to the content items. The forwarding plane of the PURSUIT ICN architecture uses a simple and light mechanism based on Bloom filter technologies to forward the packets. Although this forwarding scheme solve many problems of the today’s Internet such as the growth of the routing table and the scalability issues, it is vulnerable to brute force attacks which are starting point to distributed- denial-of-service (DDoS) attacks. In this work, we design and analyze a novel source-routing and information delivery technique that keeps the simplicity of using Bloom filter-based forwarding while being able to deter different attacks such as denial of service attacks at the ingress of the network. To achieve this, special forwarding nodes called Edge-FW are directly attached to end user nodes and used to perform a security test for malicious injected random packets at the ingress of the path to prevent any possible attack brute force attacks at early stage. In this technique, a core entity of the PURSUIT ICN architecture called topology manager, that is responsible for finding shortest path and creating a forwarding identifiers (FId), uses a cryptographically secure hash function to create a 64-bit hash, h, over the formed FId for authentication purpose to be included in the packet. Our proposal restricts the attacker from injecting packets carrying random FIds with a high amount of filling factor ρ, by optimizing and reducing the maximum allowed filling factor ρm in the network. We optimize the FId to the minimum possible filling factor where ρ ≤ ρm, while it supports longer delivery trees, so the network scalability is not affected by the chosen ρm. With this scheme, the filling factor of any legitimate FId never exceeds the ρm while the filling factor of illegitimate FIds cannot exceed the chosen small value of ρm. Therefore, injecting a packet containing an FId with a large value of filling factor, to achieve higher attack probability, is not possible anymore. The preliminary analysis of this proposal indicates that with the designed scheme, the forwarding function can detect and prevent malicious activities such DDoS attacks at early stage and with very high probability.Keywords: forwarding identifier, filling factor, information centric network, topology manager
Procedia PDF Downloads 14417413 First Formaldehyde Retrieval Using the Raw Data Obtained from Pandora in Seoul: Investigation of the Temporal Characteristics and Comparison with Ozone Monitoring Instrument Measurement
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In this present study, for the first time, we retrieved the Formaldehyde (HCHO) Vertical Column Density (HCHOVCD) using Pandora instruments in Seoul, a megacity in northeast Asia, for the period between 2012 and 2014 and investigated the temporal characteristics of HCHOVCD. HCHO Slant Column Density (HCHOSCD) was obtained using the Differential Optical Absorption Spectroscopy (DOAS) method. HCHOSCD was converted to HCHOVCD using geometric Air Mass Factor (AMFG) as Pandora is the direct-sun measurement. The HCHOVCDs is low at 12:00 Local Time (LT) and is high in the morning (10:00 LT) and late afternoon (16:00 LT) except for winter. The maximum (minimum) values of Pandora HCHOVCD are 2.68×1016 (1.63×10¹⁶), 3.19×10¹⁶ (2.23×10¹⁶), 2.00×10¹⁶ (1.26×10¹⁶), and 1.63×10¹⁶ (0.82×10¹⁶) molecules cm⁻² in spring, summer, autumn, and winter, respectively. In terms of seasonal variations, HCHOVCD was high in summer and low in winter which implies that photo-oxidation plays an important role in HCHO production in Seoul. In comparison with the Ozone Monitoring Instrument (OMI) measurements, the HCHOVCDs from the OMI are lower than those from Pandora. The correlation coefficient (R) between monthly HCHOVCDs values from Pandora and OMI is 0.61, with slop of 0.35. Furthermore, to understand HCHO mixing ratio within Planetary Boundary Layer (PBL) in Seoul, we converted Pandora HCHOVCDs to HCHO mixing ratio in the PBL using several meteorological input data from the Atmospheric InfraRed Sounder (AIRS). Seasonal HCHO mixing ratio in PBL converted from Pandora (OMI) HCHOVCDs are estimated to be 6.57 (5.17), 7.08 (6.68), 7.60 (4.70), and 5.00 (4.76) ppbv in spring, summer, autumn, and winter, respectively.Keywords: formaldehyde, OMI, Pandora, remote sensing
Procedia PDF Downloads 14717412 Anti-Neuroinflammatory and Anti-Apoptotic Efficacy of Equol, against Lipopolysaccharide Activated Microglia and Its Neurotoxicity
Authors: Lalita Subedi, Jae Kyoung Chae, Yong Un Park, Cho Kyo Hee, Lee Jae Hyuk, Kang Min Cheol, Sun Yeou Kim
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Neuroinflammation may mediate the relationship between low levels of estrogens and neurodegenerative disease. Estrogens are neuroprotective and anti-inflammatory in neurodegenerative disease models. Due to the long term side effects of estrogens, researches have been focused on finding an effective phytoestrogens for biological activities. Daidzein present in soybeans and its active metabolite equol (7-hydroxy-3-(4'-hydroxyphenyl)-chroman) bears strong antioxidant and anticancer showed more potent anti-inflammatory and neuroprotective role in neuroinflammatory model confirmed its in vitro activity with molecular mechanism through NF-κB pathway. Three major CNS cells Microglia (BV-2), Astrocyte (C6), Neuron (N2a) were used to find the effect of equol in inducible nitric oxide synthase (iNOS), cyclooxygenase (COX-2), MAPKs signaling proteins, apoptosis related proteins by western blot analysis. Nitric oxide (NO) and prostaglandin E2 (PGE2) was measured by the Gries method and ELISA, respectively. Cytokines like tumor necrosis factor-α (TNF-α) and IL-6 were also measured in the conditioned medium of LPS activated cells with or without equol. Equol inhibited the NO production, PGE-2 production and expression of COX-2 and iNOS in LPS-stimulated microglial cells at a dose dependent without any cellular toxicity. At the same time Equol also showed promising effect in modulation of MAPK’s and nuclear factor kappa B (NF-κB) expression with significant inhibition of the production of proinflammatory cytokine like interleukin -6 (IL-6), and tumor necrosis factor -α (TNF-α). Additionally, it inhibited the LPS activated microglia-induced neuronal cell death by downregulating the apoptotic phenomenon in neuronal cells. Furthermore, equol increases the production of neurotrophins like NGF and increase the neurite outgrowth as well. In conclusion the natural daidzein metabolite equol are more active than daidzein, which showed a promising effectiveness as an anti-neuroinflammatory and neuroprotective agent via downregulating the LPS stimulated microglial activation and neuronal apoptosis. This work was supported by Brain Korea 21 Plus project and High Value-added Food Technology Development Program 114006-4, Ministry of Agriculture, Food and Rural Affairs.Keywords: apoptosis, equol, neuroinflammation, phytoestrogen
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