Search results for: manning’s equation for open channel flow
2576 Frequency Analysis Using Multiple Parameter Probability Distributions for Rainfall to Determine Suitable Probability Distribution in Pakistan
Authors: Tasir Khan, Yejuan Wang
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The study of extreme rainfall events is very important for flood management in river basins and the design of water conservancy infrastructure. Evaluation of quantiles of annual maximum rainfall (AMRF) is required in different environmental fields, agriculture operations, renewable energy sources, climatology, and the design of different structures. Therefore, the annual maximum rainfall (AMRF) was performed at different stations in Pakistan. Multiple probability distributions, log normal (LN), generalized extreme value (GEV), Gumbel (max), and Pearson type3 (P3) were used to find out the most appropriate distributions in different stations. The L moments method was used to evaluate the distribution parameters. Anderson darling test, Kolmogorov- Smirnov test, and chi-square test showed that two distributions, namely GUM (max) and LN, were the best appropriate distributions. The quantile estimate of a multi-parameter PD offers extreme rainfall through a specific location and is therefore important for decision-makers and planners who design and construct different structures. This result provides an indication of these multi-parameter distribution consequences for the study of sites and peak flow prediction and the design of hydrological maps. Therefore, this discovery can support hydraulic structure and flood management.Keywords: RAMSE, multiple frequency analysis, annual maximum rainfall, L-moments
Procedia PDF Downloads 852575 Aerodynamic Prediction and Performance Analysis for Mars Science Laboratory Entry Vehicle
Authors: Tang Wei, Yang Xiaofeng, Gui Yewei, Du Yanxia
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Complex lifting entry was selected for precise landing performance during the Mars Science Laboratory entry. This study aims to develop the three-dimensional numerical method for precise computation and the surface panel method for rapid engineering prediction. Detailed flow field analysis for Mars exploration mission was performed by carrying on a series of fully three-dimensional Navier-Stokes computations. The static aerodynamic performance was then discussed, including the surface pressure, lift and drag coefficient, lift-to-drag ratio with the numerical and engineering method. Computation results shown that the shock layer is thin because of lower effective specific heat ratio, and that calculated results from both methods agree well with each other, and is consistent with the reference data. Aerodynamic performance analysis shows that CG location determines trim characteristics and pitch stability, and certain radially and axially shift of the CG location can alter the capsule lifting entry performance, which is of vital significance for the aerodynamic configuration des0ign and inner instrument layout of the Mars entry capsule.Keywords: Mars entry capsule, static aerodynamics, computational fluid dynamics, hypersonic
Procedia PDF Downloads 3002574 Views of South African Academic Instructors to the Scholarship of Teaching and Learning in Anatomy Education
Authors: Lelika Lazarus, Reshma Sookrajh, Kapil S. Satyapal
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Reflecting on teaching is commonly cited as a fundamental practice for personal and professional development. Educational research into the scholarship of teaching and learning anatomy includes engaging in discipline specific literature on teaching, reflecting on individual teaching methods and communicating these findings to peers. The aim of this paper is to formally assess the opinions of senior anatomy instructors regarding the state of anatomical knowledge at their respective institutions. The context of the paper derives from ongoing debates about the perceived decline in standards of anatomical knowledge of medical students and postgraduate learners. An open ended questionnaire was devised consisting of eight direct questions seeking opinions on anatomy teaching, knowledge, and potential educational developments and general thoughts on the teaching of anatomy to medical students. These were distributed to senior anatomy Faculty (identified by the author by their affiliation with the Anatomical Society of Southern Africa) based at the eight national medical schools within the country. A number of key themes emerged. Most senior faculty felt that the standard of medical education at their respective institutions was ‘good.’. However, emphasis was also placed on the ‘quality of teaching’ incorporating clinical scenarios. There were also indications that staff are split into those that are keen to do research and those that are happy to provide teaching to medical students as their primary function. Several challenges were also highlighted such as time constraints within the medical curriculum, the lack of cadavers to reinforce knowledge and gain depth perception and lack of appropriately qualified staff. Recommendations included fostering partnerships with both clinicians and medical scientists into the anatomy curriculum thus improving teaching and research.Keywords: anatomy, education, reflection, teaching
Procedia PDF Downloads 3012573 Effect of Installation of Long Cylindrical External Store on Performance, Stability, Control and Handling Qualities of Light Transport Aircraft
Authors: Ambuj Srivastava, Narender Singh
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This paper presents the effect of installation of cylindrical external store on the performance, stability, control and handling qualities of light transport category aircraft. A pair of long cylindrical store was installed symmetrically on either side of the fuselage (port and starboard) ahead of the wing and below the fuselage bottom surface running below pilot and co-pilot window. The cylindrical store was installed as hanging from aircraft surface through specially designed brackets. The adjoining structure was sufficiently reinforced for bearing aerodynamic loads. The length to diameter ratio of long cylindrical store was ~20. Based on academic studies and flow simulation analysis, a considerable detrimental effect on single engine second segment climb performance was found which was later validated through extensive flight testing exercise. The methodology of progressive flight envelope opening was adopted. The certification was sought from Regional airworthiness authorities and for according approval.Keywords: second segment climb, maximum operating speed, cruise performance (single engine and twin engine), minimum control speed, and additional trim required
Procedia PDF Downloads 2362572 Geography Undergraduates 360⁰ Academic Peer Learning And Mentoring 2021 – 2023: A Pilot Study
Authors: N. Ayob, N. C. Nkosi, R. P. Burger, S. J. Piketh, F. Letlaila, O. Maphosa
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South African higher tertiary institution have been faced with high dropout rates. About 50 to 60% of first years drop out to due to various reasons one being inadequate academic support. Geography 111 (GEOG 111) module is historically known for having below 50% pass rate, high dropout rate and identified as a first year risk module. For the first time GEOG 111 (2021) on the Mahikeng Campus admitted 150 students pursuing more than 6 different qualifications (BA and BSc) from the Humanities Faculty and FNAS. First year students had difficulties transitioning from secondary to tertiary institutions as we shifted to remote learning while we navigate through the Covid-19 pandemic. The traditional method of teaching does not encourage students to help each other. With remote learning we do not have control over what the students share and perhaps this can be a learning opportunity to embrace peer learning and change the manner in which we assess the students. The purpose of this pilot study was to assist GEOG111 students with academic challenges whilst improving their University experience. This was a qualitative study open to all GEOG111, repeaters, students who are not confident in their Geographical knowledge and never did Geography at high school level. The selected 9 Golden Key International Honour Society Geography mentors attended an academic mentor training program with module lecturers. About 17.6% of the mentees did not have a geography background however, 94% of the mentees passed, 1 mentee had a mark of 38%. 11 of the participants had a mark >60% with one student that excelled 70%. It is evident that mentorship helped students reach their academic potential. Peer learning and mentoring are associated with improved academic performance and allows the students to take charge of their learning and academic experience. Thus an important element as we transform pedagogies at higher learning institutions.Keywords: geography, risk module, peer mentoring, peer learning
Procedia PDF Downloads 1592571 Design and Optimization of an Electromagnetic Vibration Energy Converter
Authors: Slim Naifar, Sonia Bradai, Christian Viehweger, Olfa Kanoun
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Vibration provides an interesting source of energy since it is available in many indoor and outdoor applications. Nevertheless, in order to have an efficient design of the harvesting system, vibration converters have to satisfy some criterion in terms of robustness, compactness and energy outcome. In this work, an electromagnetic converter based on mechanical spring principle is proposed. The designed harvester is formed by a coil oscillating around ten ring magnets using a mechanical spring. The proposed design overcomes one of the main limitation of the moving coil by avoiding the contact between the coil wires with the mechanical spring which leads to a better robustness for the converter. In addition, the whole system can be implemented in a cavity of a screw. Different parameters in the harvester were investigated by finite element method including the magnet size, the coil winding number and diameter and the excitation frequency and amplitude. A prototype was realized and tested. Experiments were performed for 0.5 g to 1 g acceleration. The used experimental setup consists of an electrodynamic shaker as an external artificial vibration source controlled by a laser sensor to measure the applied displacement and frequency excitation. Together with the laser sensor, a controller unit, and an amplifier, the shaker is operated in a closed loop which allows controlling the vibration amplitude. The resonance frequency of the proposed designs is in the range of 24 Hz. Results indicate that the harvester can generate 612 mV and 1150 mV maximum open circuit peak to peak voltage at resonance for 0.5 g and 1 g acceleration respectively which correspond to 4.75 mW and 1.34 mW output power. Tuning the frequency to other values is also possible due to the possibility to add mass to the moving part of the or by changing the mechanical spring stiffness.Keywords: energy harvesting, electromagnetic principle, vibration converter, moving coil
Procedia PDF Downloads 2992570 Thermophoresis Particle Precipitate on Heated Surfaces
Authors: Rebhi A. Damseh, H. M. Duwairi, Benbella A. Shannak
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This work deals with heat and mass transfer by steady laminar boundary layer flow of a Newtonian, viscous fluid over a vertical flat plate with variable surface heat flux embedded in a fluid saturated porous medium in the presence of thermophoresis particle deposition effect. The governing partial differential equations are transformed into no-similar form by using special transformation and solved numerically by using an implicit finite difference method. Many results are obtained and a representative set is displaced graphically to illustrate the influence of the various physical parameters on the wall thermophoresis deposition velocity and concentration profiles. It is found that the increasing of thermophoresis constant or temperature differences enhances heat transfer rates from vertical surfaces and increase wall thermophoresis velocities; this is due to favourable temperature gradients or buoyancy forces. It is also found that the effect of thermophoresis phenomena is more pronounced near pure natural convection heat transfer limit; because this phenomenon is directly a temperature gradient or buoyancy forces dependent. Comparisons with previously published work in the limits are performed and the results are found to be in excellent agreement.Keywords: thermophoresis, porous medium, variable surface heat flux, heat transfer
Procedia PDF Downloads 2042569 Acceleration Techniques of DEM Simulation for Dynamics of Particle Damping
Authors: Masato Saeki
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Presented herein is a novel algorithms for calculating the damping performance of particle dampers. The particle damper is a passive vibration control technique and has many practical applications due to simple design. It consists of granular materials constrained to move between two ends in the cavity of a primary vibrating system. The damping effect results from the exchange of momentum during the impact of granular materials against the wall of the cavity. This damping has the advantage of being independent of the environment. Therefore, particle damping can be applied in extreme temperature environments, where most conventional dampers would fail. It was shown experimentally in many papers that the efficiency of the particle dampers is high in the case of resonant vibration. In order to use the particle dampers effectively, it is necessary to solve the equations of motion for each particle, considering the granularity. The discrete element method (DEM) has been found to be effective for revealing the dynamics of particle damping. In this method, individual particles are assumed as rigid body and interparticle collisions are modeled by mechanical elements as springs and dashpots. However, the computational cost is significant since the equation of motion for each particle must be solved at each time step. In order to improve the computational efficiency of the DEM, the new algorithms are needed. In this study, new algorithms are proposed for implementing the high performance DEM. On the assumption that behaviors of the granular particles in the each divided area of the damper container are the same, the contact force of the primary system with all particles can be considered to be equal to the product of the divided number of the damper area and the contact force of the primary system with granular materials per divided area. This convenience makes it possible to considerably reduce the calculation time. The validity of this calculation method was investigated and the calculated results were compared with the experimental ones. This paper also presents the results of experimental studies of the performance of particle dampers. It is shown that the particle radius affect the noise level. It is also shown that the particle size and the particle material influence the damper performance.Keywords: particle damping, discrete element method (DEM), granular materials, numerical analysis, equivalent noise level
Procedia PDF Downloads 4582568 Nanoenergetic Materials as Effective Heat Energy Sources for Enhanced Gas Generators
Authors: Sang Beom Kim, Kyung Ju Kim, Myung Hoon Cho, Ji Hoon Kim, Soo Hyung Kim
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In this study, we systematically investigated the effect of nanoscale energetic materials in formulations of aluminum nanoparticles (Al NPs; heat source)/copper oxide nanoparticles (CuO NPs; oxidizer) on the combustion and gas-generating properties of sodium azide microparticles (NaN3 MPs; gas-generating agent) for potential applications in gas generators. The burn rate of the NaN3 MP/CuO NP composite powder was only ~0.3 m/s. However, the addition of Al NPs to the NaN3 MP/CuO NP matrix caused the rates to reach ~5.3 m/s, respectively. In addition, the N2 gas volume flow rate generated by the ignition of the NaN3 MP/CuO NP composite powder was only ~0.6 L/s, which was significantly increased to ~3.9 L/s by adding Al NPs to the NaN3 MP/CuO NP composite powder. This suggested that the highly reactive NPs, with the assistance of CuO NPs, were effective heat-generating sources enabling the complete thermal decomposition of NaN3 MPs upon ignition. Al NPs were highly effective in the gas generators because of the increased reactivity induced by the reduced particle size. Finally, we successfully demonstrated that a homemade airbag with a specific volume of ~140 mL could be rapidly and fully inflated by the thermal activation of nanoscale energetic material-added gas-generating agents (i.e., NaN3 MP/Al NP/CuO NP composites) within the standard time of ~50 ms for airbag inflation.Keywords: nanoenergetic materials, aluminum nanoparticles, copper oxide nanoparticles, gas generators
Procedia PDF Downloads 3692567 “A Watched Pot Never Boils.” Exploring the Impact of Job Autonomy on Organizational Commitment among New Employees: A Comprehensive Study of How Empowerment and Independence Influence Workplace Loyalty and Engagement in Early Career Stages
Authors: Atnafu Ashenef Wondim
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In today’s highly competitive business environment, employees are considered a source of competitive advantage. Researchers have looked into job autonomy's effect on organizational commitment and declared superior organizational performance strongly depends on the effort and commitment of employees. The purpose of this study was to explore the relationship between job autonomy and organizational commitment from newcomer’s point of view. The mediation role of employee engagement (physical, emotional, and cognitive) was also examined in the case of Ethiopian Commercial Banks. An exploratory survey research design with mixed-method approach that included partial least squares structural equation modeling and Fuzzy-Set Qualitative Comparative Analysis technique were using to address the sample size of 348 new employees. In-depth interviews with purposive and convenientsampling techniques are conducted with new employees (n=43). The results confirmed that job autonomy had positive, significant direct effects on physical engagement, emotional engagement, and cognitive engagement (path coeffs. = 0.874, 0.931, and 0.893).The results showed thatthe employee engagement driver, physical engagement, had a positive significant influence on affective commitment (path coeff. = 0.187) and normative commitment (path coeff. = 0.512) but no significant effect on continuance commitment. Employee engagement partially mediates the relationship between job autonomy and organizational commitment, which means supporting the indirect effects of job autonomy on affective, continuance, and normative commitment through physical engagement. The findings of this study add new perspectives by positioning it within a complex organizational African setting and by expanding the job autonomy and organizational commitment literature, which will benefit future research. Much of the literature on job autonomy and organizational commitment has been conducted within a well-established organizational business context in Western developed countries.The findings lead to fresh information on job autonomy and organizational commitment implementation enablers that can assist in the formulation of a better policy/strategy to efficiently adopt job autonomy and organizational commitment.Keywords: employee engagement, job autonomy, organizational commitment, social exchange theory
Procedia PDF Downloads 372566 Thermal Performance of Dual Flame Impinging Normally on to a Flat Surface
Authors: Satpal Singh, Subhash Chander
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An experimental study has been conducted to evaluate the thermal performance of the CNG/air dual flame impinging normally on to a flat surface. The stability limits for the dual flame under both impinging and free conditions have been evaluated to select experimental operating range. Dual flame shape and structure have been explained with direct flame image and schematic diagram indicating modification in recirculation zone in presence of inner flame. Effects of various operating parameters like H/Dh, Re(o), Φ(o), and θ(o) on heat transfer characteristics have been discussed. Inner non-swirling flame Reynolds number (Re(i)) and equivalence ratio (Φ(i)) were kept constant. Heating patterns in the impingement region around the stagnation point have been altered significantly with change in the values of H/Dh, Re(o), Φ(o), and θ(o). The axial flow of inner flame has been notably effected with increase in Re(o). Heating was most favorable near stoichiometeric conditions of the outer swirling flame. However, the effect of change in swirl intensity (expressed in terms of θ(o)) on overall heat transfer efficiency was not as significant as in the case of other parameters. It has been inferred that best performance (higher uniformity and efficiency) of the dual flame impinging on a flat surface can be achieved at moderate value of separation distance (H/Dh of 2-3) and outer swirling flame Reynolds number (Re(o) of 7000-9000) under stoichiometeric conditions.Keywords: dual flame, heat transfer, impingement, swirling insert, transmission efficiency
Procedia PDF Downloads 3002565 A Validated UPLC-MS/MS Assay Using Negative Ionization Mode for High-Throughput Determination of Pomalidomide in Rat Plasma
Authors: Muzaffar Iqbal, Essam Ezzeldin, Khalid A. Al-Rashood
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Pomalidomide is a second generation oral immunomodulatory agent, being used for the treatment of multiple myeloma in patients with disease refractory to lenalidomide and bortezomib. In this study, a sensitive UPLC-MS/MS assay was developed and validated for high-throughput determination of pomalidomide in rat plasma using celecoxib as an internal standard (IS). Liquid liquid extraction using dichloromethane as extracting agent was employed to extract pomalidomide and IS from 200 µL of plasma. Chromatographic separation was carried on Acquity BEHTM C18 column (50 × 2.1 mm, 1.7 µm) using an isocratic mobile phase of acetonitrile:10 mM ammonium acetate (80:20, v/v), at a flow rate of 0.250 mL/min. Both pomalidomide and IS were eluted at 0.66 ± 0.03 and 0.80 ± 0.03 min, respectively with a total run time of 1.5 min only. Detection was performed on a triple quadrupole tandem mass spectrometer using electrospray ionization in negative mode. The precursor to product ion transitions of m/z 272.01 → 160.89 for pomalidomide and m/z 380.08 → 316.01 for IS were used to quantify them respectively, using multiple reaction monitoring mode. The developed method was validated according to regulatory guideline for bioanalytical method validation. The linearity in plasma sample was achieved in the concentration range of 0.47–400 ng/mL (r2 ≥ 0.997). The intra and inter-day precision values were ≤ 11.1% (RSD, %) whereas accuracy values ranged from - 6.8 – 8.5% (RE, %). In addition, other validation results were within the acceptance criteria and the method was successfully applied in a pharmacokinetic study of pomalidomide in rats.Keywords: pomalidomide, pharmacokinetics, LC-MS/MS, celecoxib
Procedia PDF Downloads 3922564 Clinical Utility of Salivary Cytokines for Children with Attention Deficit Hyperactivity Disorder
Authors: Masaki Yamaguchi, Daimei Sasayama, Shinsuke Washizuka
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The goal of this study was to examine the possibility of salivary cytokines for the screening of attention deficit hyperactivity disorder (ADHD) in children. We carried out a case-control study, including 19 children with ADHD and 17 healthy children (controls). A multiplex bead array immunoassay was used to conduct a multi-analysis of 27 different salivary cytokines. Six salivary cytokines (interleukin (IL)-1β, IL-8, IL12p70, granulocyte colony-stimulating factor (G-CSF), interferon gamma (IFN-γ), and vascular endothelial growth factor (VEGF)) were significantly associated with the presence of ADHD (p < 0.05). An informative salivary cytokine panel was developed using VEGF by logistic regression analysis (odds ratio: 0.251). Receiver operating characteristic analysis revealed that assessment of a panel using VEGF showed “good” capability for discriminating between ADHD patients and controls (area under the curve: 0.778). ADHD has been hypothesized to be associated with reduced cerebral blood flow in the frontal cortex, due to reduced VEGF levels. Our study highlights the possibility of utilizing differential salivary cytokine levels for point-of-care testing (POCT) of biomarkers in children with ADHD.Keywords: cytokine, saliva, attention deficit hyperactivity disorder, child
Procedia PDF Downloads 1462563 Private Universities and Socio-Economic Development of Host Communities: The Case of Fountain University, Nigeria
Authors: Ganiyu Rasaq Omokeji
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The growing recognition of the pivotal role of universities in promoting socio-economic development has led to a focus upon the expansion of the sector around the world. As the economy and society become more ‘knowledge intensive’, the role of universities in development is more onerous than just teaching, research, and service. It is to help create the open society upon which the progress of ideas depends on. Driven to fulfill this role, universities are likely to become even more important in building regional networks of their host communities. Currently, there are about 129 universities in Nigeria, with a total number of 37 federal, 36 state, and 56 privately owned universities. Fountain University is among the private universities in Nigeria located in Osogbo, Osun State. The university is committed to the total development of men and women in an enabling environment, through appropriate teaching, research, and service to humanity, influenced by Islamic ethics and culture. The university focuses on educational development and growth that are relevant to the nation’s manpower needs and global competitiveness through a gradual but steady process. This paper examines the role of Private University in the socio-economic development of host community using Fountain University as a case study. The research methodology design for this paper has a total of 200 respondents. The research instrument of data collection was a questionnaire and in-depth interview (IDI). The finding reveals that Fountain University plays an important role in socio-economic and cultural development through their Islamic culture. The paper recommend that universities must bridge the gaps between creative individual with innovative ideas and the application of technology for economic progress and social betterment of their host communities. University also must serve as a bridge that carries the traffic of social and economic development.Keywords: private university, socio-economic development, host communities, role of universities and community development
Procedia PDF Downloads 2862562 Studies on Mechanical Properties of Concrete and Mortar Containing Waste Glass Aggregate
Authors: Nadjoua Bourmatte, Hacène Houari
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Glass has been indispensable to men’s life due to its properties, including pliability to take any shape with ease, bright surface, resistance to abrasion, reasonable safety and durability. Waste glass creates serious environmental problems, mainly due to the inconsistency of waste glass streams. With increasing environmental pressure to reduce solid waste and to recycle as much as possible, the concrete industry has adopted a number of methods to achieve this goal. The object of this research work is to study the effect of using recycled glass waste, as a partial replacement of fine aggregate, on the fresh and hardened properties of concrete. Recycled glass was used to replace fine aggregate in proportions of 0%, 25% and 50%. We could observe that the Glass waste aggregates are lighter than natural aggregates and they show a very low water absorption. The experimental results showed that the slump flow increased with the increase of recycled glass content. On the other hand, the compressive strength and tensile strength of recycled glass mixtures decreased with the increase in the recycled glass content. The results showed that recycled glass aggregate can successfully be used with limited level for producing concrete. The standard sand was substituted with aggregates based on glass waste for manufacturing mortars, Mortar based on glass shows a compressive strength and low bending with a 1/2 ratio with control mortar strength.Keywords: concrete, environment, glass waste, recycling
Procedia PDF Downloads 2352561 Developing an Automated Protocol for the Wristband Extraction Process Using Opentrons
Authors: Tei Kim, Brooklynn McNeil, Kathryn Dunn, Douglas I. Walker
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To better characterize the relationship between complex chemical exposures and disease, our laboratory uses an approach that combines low-cost, polydimethylsiloxane (silicone) wristband samplers that absorb many of the chemicals we are exposed to with untargeted high-resolution mass spectrometry (HRMS) to characterize 1000’s of chemicals at a time. In studies with human populations, these wristbands can provide an important measure of our environment: however, there is a need to use this approach in large cohorts to study exposures associated with the disease. To facilitate the use of silicone samplers in large scale population studies, the goal of this research project was to establish automated sample preparation methods that improve throughput, robustness, and scalability of analytical methods for silicone wristbands. Using the Opentron OT2 automated liquid platform, which provides a low-cost and opensource framework for automated pipetting, we created two separate workflows that translate the manual wristband preparation method to a fully automated protocol that requires minor intervention by the operator. These protocols include a sequence generation step, which defines the location of all plates and labware according to user-specified settings, and a transfer protocol that includes all necessary instrument parameters and instructions for automated solvent extraction of wristband samplers. These protocols were written in Python and uploaded to GitHub for use by others in the research community. Results from this project show it is possible to establish automated and open source methods for the preparation of silicone wristband samplers to support profiling of many environmental exposures. Ongoing studies include deployment in longitudinal cohort studies to investigate the relationship between personal chemical exposure and disease.Keywords: bioinformatics, automation, opentrons, research
Procedia PDF Downloads 1192560 Flame Retardancy of Organophosphorus Compound on Cellulose - an Eco Friendly Concern
Authors: M. A. Hannan, N. Matthias Neisius
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Organophosphorus compound diethyloxymethyl-9-oxa-10-phosphaphenanthrene-10-oxide (DOPAC) was applied on cotton cellulose to impart eco-friendly flame retardant property to it. Here acetal linkage was introduced rather than conventionally used ester linkage to rescue from the undurability problem of flame retardant compound. Some acidic catalysts, sodium dihydrogen phosphate (NaH2PO4), ammonium dihydrogen phosphate (NH4H2PO4) and phosphoric acid (H3PO4) were successfully used to form acetal linkage between the base material and flame retardant compound. Inspiring limiting oxygen index (LOI) value of 22.4 was found after exclusive washing treatment. A good outcome of total heat of combustion (THC) 6.05 KJ/g was found possible during pyrolysis combustion flow calorimetry (PCFC) test of the treated sample. Low temperature dehydration with sufficient amount of char residue (14.89%) was experienced in case of treated sample. In addition, the temperature of peak heat release rate (TPHRR) 343.061°C supported the expected low temperature pyrolysis in condensed phase mechanism. With the consequence of pyrolysis effects, thermogravimetric analysis (TGA) also reported inspiring weight retention% of the treated samples.Keywords: acetal linkage, char residue, cotton cellulose, flame retardant, loi, low temperature pyrolysis, organophosphorus, THC, THRR
Procedia PDF Downloads 3052559 Mapping Stress in Submerged Aquatic Vegetation Using Multispectral Imagery and Structure from Motion Photogrammetry
Authors: Amritha Nair, Fleur Visser, Ian Maddock, Jonas Schoelynck
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Inland waters such as streams sustain a rich variety of species and are essentially hotspots for biodiversity. Submerged aquatic vegetation, also known as SAV, forms an important part of ecologically healthy river systems. Direct and indirect human influences, such as climate change are putting stress on aquatic plant communities, ranging from the invasion of non-native species and grazing, to changes in the river flow conditions and temperature. There is a need to monitor SAV, because they are in a state of deterioration and their disappearance will greatly impact river ecosystems. Like terrestrial plants, SAV can show visible signs of stress. However, the techniques used to map terrestrial vegetation from its spectral reflectance, are not easily transferable to a submerged environment. Optical remote sensing techniques are employed to detect the stress from remotely sensed images through multispectral imagery and Structure from Motion photogrammetry. The effect of the overlying water column in the form of refraction, attenuation of visible and near infrared bands in water, as well as highly moving targets, are NIR) key challenges that arise when remotely mapping SAV. This study looks into the possibility of mapping the changes in spectral signatures from SAV and their response to certain stresses.Keywords: submerged aquatic vegetation, structure from motion, photogrammetry, multispectral, spectroscopy
Procedia PDF Downloads 1042558 Pistachio Supplementation Ameliorates the Motor and Cognitive Deficits in Rotenone-Induced Rat Model of Parkinson’s Disease
Authors: Saida Haider, Syeda Madiha
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Parkinson’s disease (PD) is a common neurological disorder characterized by motor deficits and loss of dopaminergic neurons. Oxidative stress is said to play a pivotal role in the pathophysiology of the disease. In the present study, PD was induced by injection of rotenone (1.5 mg/kg/day, s.c.) for eight days. Pistachio (800 mg/kg/day, p.o.) was given for two weeks. At the end of treatment brains were dissected out and striatum was isolated for biochemical and neurochemical analysis. Morris water maze (MWM) test and novel object recognition (NOR) task was used to test the memory function while motor behavior was determined by open field test (OFT), Kondziela inverted screen test (KIST), pole test (PT), beam walking test (BWT), inclined plane test (IPT) and footprint (FP) test. Several dietary components have been evaluated as potential therapeutic compounds in many neurodegenerative diseases. Increasing evidence shows that nuts have protective effects against various diseases by improving the oxidative status and reducing lipid peroxidation. Pistachio is the only nut that contains anthocyanin, a potent antioxidant having neuroprotective properties. Results showed that pistachio supplementation significantly restored the rotenone-induced motor deficits and improved the memory performance. Moreover, rats treated with pistachio also exhibited enhanced oxidative status and increased dopamine (DA) and 5-hydroxytryptamine (5-HT) concentration in striatum. In conclusion, to our best knowledge, we have for the first time shown that pistachio nut possesses neuroprotective effects against rotenone-induced motor and cognitive deficits. These beneficial effects of pistachio may be attributed to its high content of natural antioxidant and phenolic compounds. Hence, consumption of pistachio regularly as part of a daily diet can be beneficial in the prevention and treatment of PD.Keywords: rotenone, pistachio, oxidative stress, Parkinson’s disease
Procedia PDF Downloads 1112557 Comparative Study in Treatment of Distal Humerus Fracture with Lateral Column Plate Percutaneous Medial Screw and Intercondylar Screw
Authors: Sameer Gupta, Prant Gupta
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Context: Fractures in the distal humerus are complex and challenging injuries for orthopaedic surgeons that can be effectively treated with open reduction and internal fixation. Aims: The study analyses clinical outcomes in patients with intra-articular distal humerus fractures (AO type 13 C3 excluded) treated using a different method of fixation ( LCPMS). Subject and Methods: A study was performed, and the author's personal experiences were reported. Thirty patients were treated using an intercondylar screw with lateral column plating and percutaneous medial column screw fixation. Detailed analysis was done for functional outcomes (average arc of motion, union rate, and complications). Statistical Analysis Used: SPSS software version 22.0 was used for statistical analysis. Results: In our study, at the end of 6 months, Overall good to excellent results were achieved in 28 patients out of 30 after analysis on the basis of MEP score. The majority of patients regained full arc of motion, achieved fracture union without any major complications, and were able to perform almost all activities of daily living (which required good elbow joint movements and functions). Conclusion: We concluded that this novel method provides adequate stability and anatomical reconstruction with an early union rate observed at the end of 6 months. Excellent functional outcome was observed in almost all the patients because of less operating time and initiation of early physiotherapy, as most of the patients experienced mild nature of pain post-surgery.Keywords: intra arricular distal humerus fracture, percutaneous medial screw, lateral column plate, arc of motion
Procedia PDF Downloads 632556 Microwave Freeze Drying of Fruit Foams for the Production of Healthy Snacks
Authors: Sabine Ambros, Mine Oezcelik, Evelyn Dachmann, Ulrich Kulozik
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Nutritional quality and taste of dried fruit products is still often unsatisfactory and does not meet anymore the current consumer trends. Dried foams from fruit puree could be an attractive alternative. Due to their open-porous structure, a new sensory perception with a sudden and very intense aroma release could be generated. To make such high quality fruit snacks affordable for the consumer, a gentle but at the same time fast drying process has to be applied. Therefore, microwave-assisted freeze drying of raspberry foams was investigated in this work and compared with the conventional freeze drying technique in terms of nutritional parameters such as antioxidative capacity, anthocyanin content and vitamin C and the physical parameters colour and wettability. The following process settings were applied: 0.01 kPa chamber pressure and a maximum temperature of 30 °C for both freeze and microwave freeze drying. The influence of microwave power levels on the dried foams was investigated between 1 and 5 W/g. Intermediate microwave power settings led to the highest nutritional values, a colour appearance comparable to the undried foam and a proper wettability. A proper process stability could also be guaranteed for these power levels. By the volumetric energy input of the microwaves drying time could be reduced from 24 h in conventional freeze drying to about 6 h. The short drying times further resulted in an equally high maintenance of the above mentioned parameters in both drying techniques. Hence, microwave assisted freeze drying could lead to a process acceleration in comparison to freeze drying and be therefore an interesting alternative drying technique which on industrial scale enables higher efficiency and higher product throughput.Keywords: foam drying, freeze drying, fruit puree, microwave freeze drying, raspberry
Procedia PDF Downloads 3462555 Identitarian Speech in Exile by Representatives of Central Europe
Authors: Georgiana Ciobotaru
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The experience of exile is a defining one for the mittleeuropean writers, which is also the generator of an identity discourse manifested in the plan of fiction. In exile, the authors often build their marginality in opposition to that deserted mundi center. The Polish Gombrowicz carried out his existence, for more than twenty-three years, in a geographical exile, distancing himself from his country, and, from a cultural point of view, the writing meant a possibility of escape, of plunge into a literary exile that often constituted a way of conditioning the practice of writers. He opted for one of the attitudes that a writer in exile may have, namely he preferred to continue speaking Polish, although he was far from his homeland, turning to the public in his homeland, his entire literary creation in exile being promoted through Kulturia, the Paris-based immigration magazine. The problem of exile must be constantly related to three essential aspects, namely: territory, identity and language. The exile, both the writer and his characters, displays a characteristic attitude towards the abandoned land, but also towards the adoptive, towards the mother tongue, but also towards the idiom encountered, thus proving an original manner in terms of how it asserts, de-builds or re-builds its identity. In these texts written after leaving Poland, a series of open works by Trans-Atlantic, Gombrowicz assumes and internalizes the inadequacy between his self and the reality outside to make it the principle of his perception of the world. The expression of marginality that characterized the texts developed when the writer was still in Poland seems to acquire a certain coherence against the background of a logic imposed on the new experience, namely that of exile. Texts created during his exile in Argentina appear in a different context, in other words, in a situation of inadequacy towards the world: ignorance of the language, poverty, isolation that characterizes especially the first years spent there. This study aims to highlight how the Polish author de-builds and reconstructs his Mittel-European identity profile through language.Keywords: discourse, exile, identity, immigration
Procedia PDF Downloads 1412554 Causal-Explanatory Model of Academic Performance in Social Anxious Adolescents
Authors: Beatriz Delgado
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Although social anxiety is one of the most prevalent disorders in adolescents and causes considerable difficulties and social distress in those with the disorder, to date very few studies have explored the impact of social anxiety on academic adjustment in student populations. The aim of this study was analyze the effect of social anxiety on school functioning in Secondary Education. Specifically, we examined the relationship between social anxiety and self-concept, academic goals, causal attributions, intellectual aptitudes, and learning strategies, personality traits, and academic performance, with the purpose of creating a causal-explanatory model of academic performance. The sample consisted of 2,022 students in the seven to ten grades of Compulsory Secondary Education in Spain (M = 13.18; SD = 1.35; 51.1% boys). We found that: (a) social anxiety has a direct positive effect on internal attributional style, and a direct negative effect on self-concept. Social anxiety also has an indirect negative effect on internal causal attributions; (b) prior performance (first academic trimester) exerts a direct positive effect on intelligence, achievement goals, academic self-concept, and final academic performance (third academic trimester), and a direct negative effect on internal causal attributions. It also has an indirect positive effect on causal attributions (internal and external), learning goals, achievement goals, and study strategies; (c) intelligence has a direct positive effect on learning goals and academic performance (third academic trimester); (d) academic self-concept has a direct positive effect on internal and external attributional style. Also, has an indirect effect on learning goals, achievement goals, and learning strategies; (e) internal attributional style has a direct positive effect on learning strategies and learning goals. Has a positive but indirect effect on achievement goals and learning strategies; (f) external attributional style has a direct negative effect on learning strategies and learning goals and a direct positive effect on internal causal attributions; (g) learning goals have direct positive effect on learning strategies and achievement goals. The structural equation model fit the data well (CFI = .91; RMSEA = .04), explaining 93.8% of the variance in academic performance. Finally, we emphasize that the new causal-explanatory model proposed in the present study represents a significant contribution in that it includes social anxiety as an explanatory variable of cognitive-motivational constructs.Keywords: academic performance, adolescence, cognitive-motivational variables, social anxiety
Procedia PDF Downloads 3352553 Process Integration of Natural Gas Hydrate Production by CH₄-CO₂/H₂ Replacement Coupling Steam Methane Reforming
Authors: Mengying Wang, Xiaohui Wang, Chun Deng, Bei Liu, Changyu Sun, Guangjin Chen, Mahmoud El-Halwagi
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Significant amounts of natural gas hydrates (NGHs) are considered potential new sustainable energy resources in the future. However, common used methods for methane gas recovery from hydrate sediments require high investment but with low gas production efficiency, and may cause potential environment and security problems. Therefore, there is a need for effective gas production from hydrates. The natural gas hydrate production method by CO₂/H₂ replacement coupling steam methane reforming can improve the replacement effect and reduce the cost of gas separation. This paper develops a simulation model of the gas production process integrated with steam reforming and membrane separation. The process parameters (i.e., reactor temperature, pressure, H₂O/CH₄ ratio) and the composition of CO₂ and H₂ in the feed gas are analyzed. Energy analysis is also conducted. Two design scenarios with different composition of CO₂ and H₂ in the feed gas are proposed and evaluated to assess the energy efficiency of the novel system. Results show that when the composition of CO₂ in the feed gas is between 43 % and 72 %, there is a certain composition that can meet the requirement that the flow rate of recycled gas is equal to that of feed gas, so as to ensure that the subsequent production process does not need to add feed gas or discharge recycled gas. The energy efficiency of the CO₂ in feed gas at 43 % and 72 % is greater than 1, and the energy efficiency is relatively higher when the CO₂ mole fraction in feed gas is 72 %.Keywords: Gas production, hydrate, process integration, steam reforming
Procedia PDF Downloads 1852552 Generalized Synchronization in Systems with a Complex Topology of Attractor
Authors: Olga I. Moskalenko, Vladislav A. Khanadeev, Anastasya D. Koloskova, Alexey A. Koronovskii, Anatoly A. Pivovarov
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Generalized synchronization is one of the most intricate phenomena in nonlinear science. It can be observed both in systems with a unidirectional and mutual type of coupling including the complex networks. Such a phenomenon has a number of practical applications, for example, for the secure information transmission through the communication channel with a high level of noise. Known methods for the secure information transmission needs in the increase of the privacy of data transmission that arises a question about the observation of such phenomenon in systems with a complex topology of chaotic attractor possessing two or more positive Lyapunov exponents. The present report is devoted to the study of such phenomenon in two unidirectionally and mutually coupled dynamical systems being in chaotic (with one positive Lyapunov exponent) and hyperchaotic (with two or more positive Lyapunov exponents) regimes, respectively. As the systems under study, we have used two mutually coupled modified Lorenz oscillators and two unidirectionally coupled time-delayed generators. We have shown that in both cases the generalized synchronization regime can be detected by means of the calculation of Lyapunov exponents and phase tube approach whereas due to the complex topology of attractor the nearest neighbor method is misleading. Moreover, the auxiliary system approaches being the standard method for the synchronous regime observation, for the mutual type of coupling results in incorrect results. To calculate the Lyapunov exponents in time-delayed systems we have proposed an approach based on the modification of Gram-Schmidt orthogonalization procedure in the context of the time-delayed system. We have studied in detail the mechanisms resulting in the generalized synchronization regime onset paying a great attention to the field where one positive Lyapunov exponent has already been become negative whereas the second one is a positive yet. We have found the intermittency here and studied its characteristics. To detect the laminar phase lengths the method based on a calculation of local Lyapunov exponents has been proposed. The efficiency of the method has been verified using the example of two unidirectionally coupled Rössler systems being in the band chaos regime. We have revealed the main characteristics of intermittency, i.e. the distribution of the laminar phase lengths and dependence of the mean length of the laminar phases on the criticality parameter, for all systems studied in the report. This work has been supported by the Russian President's Council grant for the state support of young Russian scientists (project MK-531.2018.2).Keywords: complex topology of attractor, generalized synchronization, hyperchaos, Lyapunov exponents
Procedia PDF Downloads 2782551 Adaptable Regulatory Oversight and Safety Awareness Regime: An Experience-Based Contribution Towards Sustainability in a Changing Railway Environment
Authors: Peaceman Sopazi, Mabila Mathebula, John Smallwood
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Recent health and safety (H&S) concerns and their resultant impact on railway operations, namely, the severe acute respiratory syndrome (SARS) or collectively known as SARS-CoV-2 (Covid-19) pandemic and the Fourth Industrial Revolution (4IR), which have dominated public discourse, brought into question as to whether, or not, some aspects of how we have so far managed safety oversight as railway regulatory bodies and operators will remain relevant in a changing railway environment. Railway practitioners have generally found themselves between a proverbial rock and a hard place by being confronted by emerging challenges which have brought along great opportunities for sustainability. As witnesses and participants to the progressively introduced railway safety management, and transformation regimes, this paper attempts to share gathered field experience on adaptable regulatory oversight and safety awareness. The discourse is approached from a South African context but also with an informed perspective of what seems to work and what usually does not. The authors share their own multi and transdisciplinary experience coupled with insights they have gained as researchers of global trends in general safety management and specific aspects of railway safety management, for sustainability. In addition to sharing a largely experience-based methodology for survival, suggestions are offered for consideration as a way of keeping the railway safety management discourse alive as practitioners navigate a new path which is shrouded in a cloud of untold uncertainty. The authors further believe that the right timing for the implementation of the proposed suggestions in this paper will produce beneficial outcomes. Finally, the paper will identify areas that are still open for further investigation for and by researchers and practitioners alike.Keywords: health & safety management, safety awareness, railway safety management, railway systems sustainability
Procedia PDF Downloads 1742550 Differential Infection of Primary Human B-Cells and EBV Positive B-Lymphoma Cell Lines by Recombinant AAV Serotypes
Authors: Elham Ahmadi, Mehrdad Ravanshad, Joyce Fingeroth, Mazyar Ziyaeyan, Rajesh Panigrahi, Jun Xie, Gao Guangping
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B-cell proliferative disorders often occur among persons that are T-cell compromised. These disorders are primarily EBV+ and can first present with a focal lesion. Direct introduction of oncolytic viruses into localized tumors provides theoretical advantages over chemotherapy and immunotherapy by reducing systemic toxicity, to which the immunocompromised host is most vulnerable. Widely studied as a vehicle for gene therapy, AAV has only rarely been applied to treat cancer. As a prelude to development of a therapeutic vehicle, we assessed the ability of 15 distinct recombinant AAV serotypes (rAAV1, rAAV2, rAAV3b, rAAV4, rAAV5, rAAV6, rAAV6.2, rAAV6TM, rAAV7, rAAV8, rAAVrh8, rAAV9, rAAVrh10, rAAV39, rAAV43) bearing eGFP to infect human B-cell tumor lines compared with primary B-cells in vitro. Enhanced infection of tumor lines by AAV 6.2 was demonstrated by flow cytometry. EBV superinfection of EBV negative B-cell tumor lines increased susceptibility to AAV6.2 infection. As proof of concept, AAV6.2 bearing HSV-1 thymidine kinase in place of eGFP eliminated tumor cells upon exposure to ganciclovir.Keywords: AAV, gene therapy, lymphoma, malignancy, tropism
Procedia PDF Downloads 1222549 Effect of the Food Distribution on Household Food Security Status in Iran
Authors: Delaram Ghodsi, Nasrin Omidvar, Hassan Eini-Zinab, Arash Rashidian, Hossein Raghfar
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Food supplementary programs are policy approaches that aim to reduce financial barriers to healthy diets and tackle food insecurity. This study aimed to evaluate the effect of the supportive section of Multidisciplinary Supplementary Program for Improvement of Nutritional Status of Children (MuPINSC) on households’ food security status and nutritional status of mothers. MuPINSC is a national integrative program in Iran that distributes supplementary food basket to malnourished or growth retarded children living in low-income families in addition to providing health services, including sanitation, growth monitoring, and empowerment of families. This longitudinal study is part of a comprehensive evaluation of the program. The study participants included 359 mothers of children aged 6 to 72 month under coverage of the supportive section of the program in two provinces of Iran (Semnan and Qazvin). Demographic and economic characteristics of families were assessed by a questionnaire. Data on food security of family was collected by locally adapted Household Food Insecurity Access Scale (HFIAS) at the baseline of the study and six month thereafter. Weight and height of mothers were measured at the baseline and end of the study and mother’s BMI was calculated. Data were analysed, using paired t-test, GEE (Generalized Estimating Equation), and Chi-square tests. Based on the findings, at the baseline, only 4.7% of families were food-secure, while 13.1%, 38.7% and, 43.5% were categorized as mild, moderate and severe food insecure. After six months follow up, the distribution of different levels of food security changed significantly (P<0.001) to 7.9%, 11.6%, 42.6%, and 38%, respectively. At the end of the study, the chance of food insecurity was significantly 20% lower than the beginning (OR=0.796; 0.653-0.971). No significant difference was observed in maternal BMI based on food security (P>0.05). The findings show that the food supplementary program for children improved household food security status in the studied households. Further research is needed to assess other factors that affect the effectiveness of this large scale program on nutritional status and household’s food security.Keywords: food security, food supplementary program, household, malnourished children
Procedia PDF Downloads 4032548 A Multimodal Dialogue Management System for Achieving Natural Interaction with Embodied Conversational Agents
Authors: Ozge Nilay Yalcin
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Dialogue has been proposed to be the natural basis for the human-computer interaction, which is behaviorally rich and includes different modalities such as gestures, posture changes, gaze, para-linguistic parameters and linguistic context. However, equipping the system with these capabilities might have consequences on the usability of the system. One issue is to be able to find a good balance between rich behavior and fluent behavior, as planning and generating these behaviors is computationally expensive. In this work, we propose a multi-modal dialogue management system that automates the conversational flow from text-based dialogue examples and uses synchronized verbal and non-verbal conversational cues to achieve a fluent interaction. Our system is integrated with Smartbody behavior realizer to provide real-time interaction with embodied agent. The nonverbal behaviors are used according to turn-taking behavior, emotions, and personality of the user and linguistic analysis of the dialogue. The verbal behaviors are responsive to the emotional value of the utterance and the feedback from the user. Our system is aimed for online planning of these affective multi-modal components, in order to achieve enhanced user experience with richer and more natural interaction.Keywords: affect, embodied conversational agents, human-agent interaction, multimodal interaction, natural interfaces
Procedia PDF Downloads 1792547 Probing Multiple Relaxation Process in Zr-Cu Base Alloy Using Mechanical Spectroscopy
Authors: A. P. Srivastava, D. Srivastava, D. J. Browne
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Relaxation dynamics of Zr44Cu40Al8Ag8 bulk metallic glass (BMG) has been probed using dynamic mechanical analyzer. The BMG sample was casted in the form of a plate of dimension 55 mm x 40 mm x 3 mm using tilt casting technique. X-ray diffraction and transmission electron microscope have been used for the microstructural characterization of as-cast BMG. For the mechanical spectroscopy study, samples in the form of a bar of size 55 mm X 2 mm X 3 mm were machined from the BMG plate. The mechanical spectroscopy was performed on dynamic mechanical analyzer (DMA) by 50 mm 3-point bending method in a nitrogen atmosphere. It was observed that two glass transition process were competing in supercooled liquid region around temperature 390°C and 430°C. The supercooled liquid state was completely characterized using DMA and differential scanning calorimeter (DSC). In addition to the main α-relaxation process, presence of β relaxation process around temperature 360°C; below the glass transition temperature was also observed. The β relaxation process could be described by Arrhenius law with the activation energy of 160 kJ/mole. The volume of the flow unit associated with this relaxation process has been estimated. The results from DMA study has been used to characterize the shear transformation zone in terms of activation volume and size. High fragility parameter value of 34 and higher activation volume indicates that this alloy could show good plasticity in supercooled liquid region. The possible mechanism for the relaxation processes has been discussed.Keywords: DMA, glass transition, metallic glass, thermoplastic forming
Procedia PDF Downloads 297