Search results for: mutual correlation matrix
4036 A High-Resolution Refractive Index Sensor Based on a Magnetic Photonic Crystal
Authors: Ti-An Tsai, Chun-Chih Wang, Hung-Wen Wang, I-Ling Chang, Lien-Wen Chen
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In this study, we demonstrate a high-resolution refractive index sensor based on a magnetic photonic crystal (MPC) composed of a triangular lattice array of air holes embedded in Si matrix. A microcavity is created by changing the radius of an air hole in the middle of the photonic crystal. The cavity filled with gyrotropic materials can serve as a refractive index sensor. The shift of the resonant frequency of the sensor is obtained numerically using finite difference time domain method under different ambient conditions having refractive index from n = 1.0 to n = 1.1. The numerical results show that a tiny change in refractive index of Δn = 0.0001 is distinguishable. In addition, the spectral response of the MPC sensor is studied while an external magnetic field is present. The results show that the MPC sensor exhibits a dramatic improvement in resolution.Keywords: magnetic photonic crystal, refractive index sensor, sensitivity, high-resolution
Procedia PDF Downloads 5934035 Cement Matrix Obtained with Recycled Aggregates and Micro/Nanosilica Admixtures
Authors: C. Mazilu, D. P. Georgescu, A. Apostu, R. Deju
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Cement mortars and concretes are some of the most used construction materials in the world, global cement production being expected to grow to approx. 5 billion tons, until 2030. But, cement is an energy intensive material, the cement industry being responsible for cca. 7% of the world's CO2 emissions. Also, natural aggregates represent non-renewable resources, exhaustible, which must be used efficiently. A way to reduce the negative impact on the environment is the use of additional hydraulically active materials, as a partial substitute for cement in mortars and concretes and/or the use of recycled concrete aggregates (RCA) for the recovery of construction waste, according to EU Directive 2018/851. One of the most effective active hydraulic admixtures is microsilica and more recently, with the technological development on a nanometric scale, nanosilica. Studies carried out in recent years have shown that the introduction of SiO2 nanoparticles into cement matrix improves the properties, even compared to microsilica. This is due to the very small size of the nanosilica particles (<100nm) and the very large specific surface, which helps to accelerate cement hydration and acts as a nucleating agent to generate even more calcium hydrosilicate which densifies and compacts the structure. The cementitious compositions containing recycled concrete aggregates (RCA) present, in generally, inferior properties compared to those obtained with natural aggregates. Depending on the degree of replacement of natural aggregate, decreases the workability of mortars and concretes with RAC, decrease mechanical resistances and increase drying shrinkage; all being determined, in particular, by the presence to the old mortar attached to the original aggregate from the RAC, which makes its porosity high and the mixture of components to require more water for preparation. The present study aims to use micro and nanosilica for increase the performance of some mortars and concretes obtained with RCA. The research focused on two types of cementitious systems: a special mortar composition used for encapsulating Low Level radioactive Waste (LLW); a composition of structural concrete, class C30/37, with the combination of exposure classes XC4+XF1 and settlement class S4. The mortar was made with 100% recycled aggregate, 0-5 mm sort and in the case of concrete, 30% recycled aggregate was used for 4-8 and 8-16 sorts, according to EN 206, Annex E. The recycled aggregate was obtained from a specially made concrete for this study, which after 28 days was crushed with the help of a Retsch jaw crusher and further separated by sieving on granulometric sorters. The partial replacement of cement was done progressively, in the case of the mortar composition, with microsilica (3, 6, 9, 12, 15% wt.), nanosilica (0.75, 1.5, 2.25% wt.), respectively mixtures of micro and nanosilica. The optimal combination of silica, from the point of view of mechanical resistance, was later used also in the case of the concrete composition. For the chosen cementitious compositions, the influence of micro and/or nanosilica on the properties in the fresh state (workability, rheological characteristics) and hardened state (mechanical resistance, water absorption, freeze-thaw resistance, etc.) is highlighted.Keywords: cement, recycled concrete aggregates, micro/nanosilica, durability
Procedia PDF Downloads 694034 Numerical Simulation of Aeroelastic Influence Exerted by Kinematic and Geometrical Parameters on Oscillations' Frequencies and Phase Shift Angles in a Simulated Compressor of Gas Transmittal Unit
Authors: Liliia N. Butymova, Vladimir Y. Modorsky, Nikolai A. Shevelev
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Prediction of vibration processes in gas transmittal units (GTU) is an urgent problem. Despite numerous scientific publications on the problem of vibrations in general, there are not enough works concerning FSI-modeling interaction processes between several deformable blades in gas-dynamic flow. Since it is very difficult to solve the problem in full scope, with all factors considered, a unidirectional dynamic coupled 1FSI model is suggested for use at the first stage, which would include, from symmetry considerations, two blades, which might be considered as the first stage of solving more general bidirectional problem. ANSYS CFX programmed multi-processor was chosen as a numerical computation tool. The problem was solved on PNRPU high-capacity computer complex. At the first stage of the study, blades were believed oscillating with the same frequency, although oscillation phases could be equal and could be different. At that non-stationary gas-dynamic forces distribution over the blades surfaces is calculated in run of simulation experiment. Oscillations in the “gas — structure” dynamic system are assumed to increase if the resultant of these gas-dynamic forces is in-phase with blade oscillation, and phase shift (φ=0). Provided these oscillation occur with phase shift, then oscillations might increase or decrease, depending on the phase shift value. The most important results are as follows: the angle of phase shift in inter-blade oscillation and the gas-dynamic force depends on the flow velocity, the specific inter-blade gap, and the shaft rotation speed; a phase shift in oscillation of adjacent blades does not always correspond to phase shift of gas-dynamic forces affecting the blades. Thus, it was discovered, that asynchronous oscillation of blades might cause either attenuation or intensification of oscillation. It was revealed that clocking effect might depend not only on the mutual circumferential displacement of blade rows and the gap between the blades, but also on the blade dynamic deformation nature.Keywords: aeroelasticity, ANSYS CFX, oscillation, phase shift, clocking effect, vibrations
Procedia PDF Downloads 2704033 Mechanical Properties of the Palm Fibers Reinforced HDPE Composites
Authors: Daniella R. Mulinari, Araujo J. F. Marina, Gabriella S. Lopes
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Natural fibers are used in polymer composites to improve mechanical properties, substituting inorganic reinforcing agents produced by non-renewable resources. The present study investigates the tensile, flexural and impact behaviors of palm fibers-high density polyethylene (HDPE) composite as a function of volume fraction. The surface of the fibers was modified by mercerization treatments to improve the wetting behavior of the apolar HDPE. The treatment characterization was obtained by scanning electron microscopy, X-Ray diffraction and infrared spectroscopy. Results evidence that a good adhesion interfacial between fibers-matrix causing an increase strength and modulus flexural as well as impact strength in the modified fibers/HDPE composites when compared to the pure HDPE and unmodified fibers reinforced composites.Keywords: palm fibers, polymer composites, mechanical properties, high density polyethylene (HDPE)
Procedia PDF Downloads 3984032 Shoulder Range of Motion Measurements using Computer Vision Compared to Hand-Held Goniometric Measurements
Authors: Lakshmi Sujeesh, Aaron Ramzeen, Ricky Ziming Guo, Abhishek Agrawal
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Introduction: Range of motion (ROM) is often measured by physiotherapists using hand-held goniometer as part of mobility assessment for diagnosis. Due to the nature of hand-held goniometer measurement procedure, readings often tend to have some variations depending on the physical therapist taking the measurements (Riddle et al.). This study aims to validate computer vision software readings against goniometric measurements for quick and consistent ROM measurements to be taken by clinicians. The use of this computer vision software hopes to improve the future of musculoskeletal space with more efficient diagnosis from recording of patient’s ROM with minimal human error across different physical therapists. Methods: Using the hand-held long arm goniometer measurements as the “gold-standard”, healthy study participants (n = 20) were made to perform 4 exercises: Front elevation, Abduction, Internal Rotation, and External Rotation, using both arms. Assessment of active ROM using computer vision software at different angles set by goniometer for each exercise was done. Interclass Correlation Coefficient (ICC) using 2-way random effects model, Box-Whisker plots, and Root Mean Square error (RMSE) were used to find the degree of correlation and absolute error measured between set and recorded angles across the repeated trials by the same rater. Results: ICC (2,1) values for all 4 exercises are above 0.9, indicating excellent reliability. Lowest overall RMSE was for external rotation (5.67°) and highest for front elevation (8.00°). Box-whisker plots showed have showed that there is a potential zero error in the measurements done by the computer vision software for abduction, where absolute error for measurements taken at 0 degree are shifted away from the ideal 0 line, with its lowest recorded error being 8°. Conclusion: Our results indicate that the use of computer vision software is valid and reliable to use in clinical settings by physiotherapists for measuring shoulder ROM. Overall, computer vision helps improve accessibility to quality care provided for individual patients, with the ability to assess ROM for their condition at home throughout a full cycle of musculoskeletal care (American Academy of Orthopaedic Surgeons) without the need for a trained therapist.Keywords: physiotherapy, frozen shoulder, joint range of motion, computer vision
Procedia PDF Downloads 1104031 Study of Rheological, Physic-Mechanical and Morphological Properties of Nitrile Butadiene Rubber Loaded with Organo-Bentonite
Authors: Doaa S. Mahmoud, Nivin M. Ahmed, Salwa H. El-Sabbagh
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The rheometric characteristics and physicomechanical properties of bentonite / acrylonitrile-butadiene rubber (NBR) were investigated. The influences of adding bentonite (Bt) and / or modified bentonite (organo-Bt) to the rubber were observed. Scanning electron microscopy (SEM) showed that the rubber chains may be confined within the interparticle space and the Bt particles presented a physical dispersion in NBR matrix. Bentonite (Bt) was modified with tetra butyl phosphonium bromide (TBP) in order to produce organo-Bt. The modification was carried out at 0.5, 1 and 2 cation exchange capacity (CEC) of bentonite. Results showed that the maximum torque of organo-Bt / NBR composite increases at high bentonite loading. The scorch time (tS2) and cure time (tC90) of the organo-Bt / NBR composites decreased simultaneously relative to those of the neat NBR. The prepared composite exhibited significant improvement in mechanical compared with that of neat NBR.Keywords: acrylonitrile-butadiene rubber, bentonite, composites, physico-mechanical properties
Procedia PDF Downloads 2674030 Diversity and Ecological Analysis of Vascular Epiphytes in Gera Wild Coffee Forest, Jimma Zone of Oromia Regional State, Ethiopia
Authors: Bedilu Tafesse
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The diversity and ecological analysis of vascular epiphytes was studied in Gera Forest in southwestern Ethiopia at altitudes between 1600 and 2400 m.a.s.l. A total area of 4.5 ha was surveyed in coffee and non-coffee forest vegetation. Fifty sampling plots, each 30 m x 30 m (900 m2), were used for the purpose of data collection. A total of 59 species of vascular epiphytes were recorded, of which 34 (59%) were holo epiphytes, two (4%) were hemi epiphytes and 22 (37%) species were accidental vascular epiphytes. To study the altitudinal distribution of vascular epiphytes, altitudes were classified into higher >2000, middle 1800-2000 and lower 1600-1800 m.a.s.l. According to Shannon-Wiener Index (H/= 3.411) of alpha diversity the epiphyte community in the study area is medium. There was a statistically significant difference between host bark type and epiphyte richness as determined by one-way ANOVA p = 0.001 < 0.05. The post-hoc test shows that there is significant difference of vascular epiphytes richness between smooth bark with rough, flack and corky bark (P =0.001< 0.05), as well as rough and cork bark (p =0.43 <0.05). However, between rough and flack bark (p = 0.753 > 0.05) and between flack and corky bark (p = 0.854 > 0.05) no significant difference of epiphyte abundance was observed. Rough bark had 38%, corky 26%, flack 25%, and only 11% vascular epiphytes abundance occurred on smooth bark. The regression correlation test, (R2 = 0.773, p = 0.0001 < 0.05), showed that the number of species of vascular epiphytes and host DBH size are positively correlated. The regression correlation test (R2 = 0.28, p = 0.0001 < 0.05), showed that the number of species and host tree height positively correlated. The host tree preference of vascular epiphytes was recorded for only Vittaria volkensii species hosted on Syzygium guineense trees. The result of similarity analysis indicated that Gera Forest showed the highest vascular epiphytic similarity (0.35) with Yayu Forest and shared the least vascular epiphytic similarity (0.295) with Harenna Forest. It was concluded that horizontal stems and branches, large and rough, flack and corky bark type trees are more suitable for vascular epiphytes seedling attachments and growth. Conservation and protection of these phorophytes are important for the survival of vascular epiphytes and increase their ecological importance.Keywords: accidental epiphytes, hemiepiphyte, holoepiphyte, phorophyte
Procedia PDF Downloads 3374029 Personal Perception of the Acoustic Properties of Three Different Rooms for Music Lessons
Authors: Natalia Ivanova, Konstantin Adamov
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The importance of acoustics in music classes made us analyse three music rooms in a Bulgarian school. The same music piece was performed in every one of the classrooms. The recording was played to 2 groups of students. A survey was then taken among those students in order to determine their personal preferences and impressions of the acoustic. The results show differences in the preferences of older students compared to younger ones. Results of the survey show a correlation between older students’ preferences and the standard requirements. However, we discover that younger students’ classrooms should be further analysed and adapted to their needs and preferences.Keywords: acousic, building acoustic, sound quality, scool acoustic
Procedia PDF Downloads 1054028 Ologen Collagen Matrix Implant in Uveitis Induced Glaucoma with Temporal Trabeculectomy
Authors: Ritesh Verma, Manisha Rathi, Chand Singh Dhull, Sumit Sachdeva, Jitender Phogat
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Temporal trabeculectomy with the Ologen implant was done in a 66-year-old lady with uveitic glaucoma. Serial IOP measurement was done to assess the efficacy of ologen implant in uveitic glaucoma. The patient had an IOP of 4mmhg day 1 postoperatively and Ologen implant was in place with a well-formed bleb. On follow up patient had an IOP of 14mmhg and unaided visual acuity of 6/12 on day 10 postoperatively. After 12 weeks of Trabeculectomy with Ologen implant, the IOP of the patient was 14 mmHg, the vision was 6/6 with -1.25 DS and -1.25 DC at 90 degrees. Trabeculectomy performed in patients with uveitic glaucoma has a higher chance of failure due to increased inflammation and fibrosis. Trabeculectomy with ologen implant done in a patient of uveitic glaucoma provides excellent postoperative results and the patient has a well-controlled IOP even after 56 weeks of surgery and a best corrected visual acuity of 6/6. Trabeculectomy with the ologen implant is superior to other surgeries in cases of secondary glaucoma with increased inflammation.Keywords: glaucoma surgery, ologen implant, temporal trabeculectomy, uveitic glaucoma
Procedia PDF Downloads 2114027 Diagnosis on Environmental Impacts of Tourism at Caju Beach in Palmas, Tocantins, Brazil
Authors: Mary L. G. S. Senna, Veruska, C. Dutra, Jr., Keity L. F. Oliveira, Patrícia A. Santos, Alana C. M. Santana
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Environmental impacts are the changes in the physical, chemical or biological properties of natural areas that are most often caused by human actions on the environment and which have consequences for human health, society and the elements of nature. The identification of the environmental impacts is important so that they are mitigated, and above all that the mitigating measures are applied in the area. This work aims to identify the environmental impacts generated in the Praia do Caju area in the city of Palmas/Brazil and show that the lack of structure on the beach intensifies the environmental impacts. The present work was carried out having as parameter, the typologies of exploratory and descriptive and quantitative research through a matrix of environmental impacts through direct observation and registration. The study took place during the holidays from August to December 2016 and photographic record of impacts. From the collected data it was possible to verify that Caju beach suffers constant degradation due to irregular deposition.Keywords: leisure, tourism, environmental impacts, Brazil
Procedia PDF Downloads 3384026 Generous Edge – Inviting the Spontaneous
Authors: Ofri Earon
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This article is about a growing focus in the city of Copenhagen – the edge zone between the private space inside the residential building and the public space out at the residential street. A slow transition between the private living room and the public urban space creates a mutual benefit. The urban space benefits from an insertion of a homey atmosphere by the extended performance of living rooms to the exterior. The dwelling benefits from belonging to a liveable neighborliness, which means an extension of the private home to a collective home (= the neighborhood). Grounded by this reciprocal value of the edge zone, through the article, it is argued that a wide generosity of the edge zones is of interest among both planners and residents. The article introduces the idea of the edge zone and its possible implications in the development of the liveable residential city. Three examples of ongoing projects at Arkitema Architects are bought to illustrate the challenges and potentials of a generous edge zone. Every example represents a specific dwelling typology in a particular urban context: (1) multi-family residential building in a previous industrial area in the city (2) new courtyard building in the city’s outskirt (3) low and dense residential area out in the suburbia. Throughout these examples, the article seeks to discuss the significance of the edge zone in forthcoming residential areas in Denmark. The analysis of the Danish examples raises the question of why a social behavior that happens spontaneously in the south of Europe has to be carefully implemented in the architecture of north of Europe. In this light, the article ends with a discussion on how to create edge zones that are not designed for a particular usage, but rather as an architectural invitation for varied social behaviors that spontaneously occur in different moments of time by different people. Finally, the article ends with a list of recommendations for the development of the generous edge zone as an open invitation for diverse usage over time.Keywords: dwelling, edge zone, generosity, livability, urban space
Procedia PDF Downloads 3584025 Investigation and Perfection of Centrifugal Compressor Stages by CFD Methods
Authors: Y. Galerkin, L. Marenina
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Stator elements «Vane diffuser + crossover + return channel» of stages with different specific speed were investigated by CFD calculations. The regime parameter was introduced to present efficiency and loss coefficient performance of all elements together. Flow structure demonstrated advantages and disadvantages of design. Flow separation in crossovers was eliminated by its shape modification. Efficiency increased visibly. Calculated CFD performances are in acceptable correlation with predicted ones by engineering design method. The information obtained is useful for design method better calibration.Keywords: vane diffuser, return channel, crossover, efficiency, loss coefficient, inlet flow angle
Procedia PDF Downloads 4314024 Singular Value Decomposition Based Optimisation of Design Parameters of a Gearbox
Authors: Mehmet Bozca
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Singular value decomposition based optimisation of geometric design parameters of a 5-speed gearbox is studied. During the optimisation, a four-degree-of freedom torsional vibration model of the pinion gear-wheel gear system is obtained and the minimum singular value of the transfer matrix is considered as the objective functions. The computational cost of the associated singular value problems is quite low for the objective function, because it is only necessary to compute the largest and smallest singular values (µmax and µmin) that can be achieved by using selective eigenvalue solvers; the other singular values are not needed. The design parameters are optimised under several constraints that include bending stress, contact stress and constant distance between gear centres. Thus, by optimising the geometric parameters of the gearbox such as, the module, number of teeth and face width it is possible to obtain a light-weight-gearbox structure. It is concluded that the all optimised geometric design parameters also satisfy all constraints.Keywords: Singular value, optimisation, gearbox, torsional vibration
Procedia PDF Downloads 3614023 Modeling and Simulation of Flow Shop Scheduling Problem through Petri Net Tools
Authors: Joselito Medina Marin, Norberto Hernández Romero, Juan Carlos Seck Tuoh Mora, Erick S. Martinez Gomez
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The Flow Shop Scheduling Problem (FSSP) is a typical problem that is faced by production planning managers in Flexible Manufacturing Systems (FMS). This problem consists in finding the optimal scheduling to carry out a set of jobs, which are processed in a set of machines or shared resources. Moreover, all the jobs are processed in the same machine sequence. As in all the scheduling problems, the makespan can be obtained by drawing the Gantt chart according to the operations order, among other alternatives. On this way, an FMS presenting the FSSP can be modeled by Petri nets (PNs), which are a powerful tool that has been used to model and analyze discrete event systems. Then, the makespan can be obtained by simulating the PN through the token game animation and incidence matrix. In this work, we present an adaptive PN to obtain the makespan of FSSP by applying PN analytical tools.Keywords: flow-shop scheduling problem, makespan, Petri nets, state equation
Procedia PDF Downloads 3004022 The Effect of Gender on the Three Types of Aggression among Kuwaiti Children
Authors: Hend Almaseb
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Child aggression is a serious social problem that affects children’s lives. This study examines the relationship between three types of aggressive behaviors–physical, verbal, and indirect aggression–from sociocultural and social work perspectives. Also, it investigates the effect of gender on the three types of aggressive behaviors and the most frequently used aggressive behaviors among a sample of 329 Kuwaiti children. The results show that there is a positive correlation between the three types of aggression and gender.Keywords: child aggression, indirect aggression, physical aggression, verbal aggression
Procedia PDF Downloads 3724021 The Interaction between Hydrogen and Surface Stress in Stainless Steel
Authors: Osamu Takakuwa, Yuta Mano, Hitoshi Soyama
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This paper reveals the interaction between hydrogen and surface stress in austenitic stainless steel by X-ray diffraction stress measurement and thermal desorption analysis before and after being charged with hydrogen. The surface residual stress was varied by surface finishing using several disc polishing agents. The obtained results show that the residual stress near surface had a significant effect on hydrogen absorption behavior, that is, tensile residual stress promoted the hydrogen absorption and compressive one did opposite. Also, hydrogen induced equi-biaxial stress and this stress has a linear correlation with hydrogen content.Keywords: hydrogen embrittlement, residual stress, surface finishing, stainless steel
Procedia PDF Downloads 3824020 Looking Elsewhere for Job: Relationship between Procedural Justice and Survivors’ Turnover Intent in Consolidated Nigeria Banks
Authors: Fasanmi Samuel Sunday
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The study examines the relationship between procedural justice and turnover intent among survivors in a consolidated Nigeria bank. Opinions of eight hundred and eighty five staff of First City Monumental Bank and Finbank who survived the consolidated process were conveniently sampled using battery of tests. Two hypotheses were tested for this study. Results revealed that procedural justice and demographic variables (sex, age, previous banking job experience, and year of work experience) were significantly, independently and jointly influence turnover intent among survivors in consolidated banks in Nigeria. Also, there was a significant relationship between procedural justice and turnover intent among survivors in a consolidated bank in Nigeria. It was recommended that if the workers perceived the process of downsizing to be fair, they tend to reason with their management and coast along with the process rather than increasing in their turnover intent which will eventually drastically reduce the profitability matrix which the banks desired so desperately.Keywords: bankers, procedural justice, sex, turnover intent
Procedia PDF Downloads 5154019 Evaluation of Methodologies for Measuring Harmonics and Inter-Harmonics in Photovoltaic Facilities
Authors: Anésio de Leles Ferreira Filho, Wesley Rodrigues de Oliveira, Jéssica Santoro Gonçalves, Jorge Andrés Cormane Angarita
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The increase in electric power demand in face of environmental issues has intensified the participation of renewable energy sources such as photovoltaics, in the energy matrix of various countries. Due to their operational characteristics, they can generate time-varying harmonic and inter-harmonic distortions. For this reason, the application of methods of measurement based on traditional Fourier analysis, as proposed by IEC 61000-4-7, can provide inaccurate results. Considering the aspects mentioned herein, came the idea of the development of this work which aims to present the results of a comparative evaluation between a methodology arising from the combination of the Prony method with the Kalman filter and another method based on the IEC 61000-4-30 and IEC 61000-4-7 standards. Employed in this study were synthetic signals and data acquired through measurements in a 50kWp photovoltaic installation.Keywords: harmonics, inter-harmonics, iec61000-4-7, parametric estimators, photovoltaic generation
Procedia PDF Downloads 4884018 Surface Modified Electrospun Expanded Polystyrene Fibre with Superhydrophobic/Superoleophillic Properties as Potential Oil Membrane
Authors: S. Oluwagbemiga Alayande, E. Olugbenga Dare, Titus A. M. Msagati, A. Kehinde Akinlabi , P. O. Aiyedun
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This paper presents a cheap route procedure for the preparation of a potential oil membrane with superhydrophobic /superoleophillic properties for selective removal of crude oil from water. In these study, expanded polystyrene (EPS) was electrospun to produce beaded fibers in which zeolite was introduced to the polymer matrix in order to impart rough surface to non-beaded fiber. Films of the EPS and EPS/Zeolite solutions were also made for comparative study. The electrospun fibers EPS, EPS/Zeolite and resultant films were characterized using SEM, BET, FTIR and optical contact angle. The fibers exhibited superhydrophic and superoleophillic wetting properties with water and crude oil. The selective removal of crude oil presents new opportunity for the re-use of EPS as adsorbent in petroleum/petrochemical industry.Keywords: expanded polystyrene, superhydrophobic, superoleophillic, oil-membrane
Procedia PDF Downloads 4734017 Numerical Simulation for Self-Loosening Phenomenon Analysis of Bolt Joint under Vibration
Authors: Long Kim Vu, Ban Dang Nguyen
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In this paper, the finite element method (FEM) is utilized to simulate the comprehensive process including tightening, releasing and self-loosening of a bolt joint under transverse vibration. Following to the accurate geometry of helical threads, an absolutely hexahedral meshing is implemented. The accuracy of simulation process is verified and validated by comparison with the experimental results on clamping force-vibration relationship, which shows the sufficient correlation. Further analysis with different amplitude and frequency of transverse vibration is done to determine the dominant factor inducing the failure.Keywords: bolt self-loosening, contact state, finite element method, FEM, helical thread modeling
Procedia PDF Downloads 2034016 Relationship of Sexually Abusive Behavior of Male Coach and Motivation of Female Athletes at Public Sector Universities, Sindh, Pakistan
Authors: Shireen Bhatti, M. Asif Shaikh, Atif Khan
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Sexually abusive behavior is seen as a social phenomenon across different societies and different territories. An institution of sport has its own uniqueness. It is different from other workplaces and academia. The challenges in sports raised are different, which require a call to action for specific sexual harassment policies and practices. Many sportswomen who are members of team games or individual games experience sexually abusive behavior from their male counterparts, including trainers, coaches, and lower staff. The power of the coach over the athlete is massive due to the coach’s position. The power can be disguised for possible abuse, whether physical or emotional. Female athletes are victims in most offensive situations that occur in collegiate settings by male coaches. The objective of the study is to identify the relationship between the sexually abusive behavior of male coaches and the motivation of female athletes at public sector universities in Sindh, Pakistan. The descriptive approach was used, whereas The cross-sectional survey design was used to support the study. Intercollegiate, intervarsity, provincial, and national level female athletes of public sector universities of Sindh province were the subject of this study. The tool of research was a self-developed scale that encompassed the relationship between the sexually abusive behaviors of coaches and the motivation of female athletes. Frequency, percentage, and mean and Pearson Correlation, chi square, and ANOVA were used. The results indicate that there is a strong negative relationship between the sexually abusive behavior of male coaches and female athletes’ sports motivation. The Pearson correlation shows that there is a strong negative relation between the sexually abusive behavior of male athletes and female athletes’ sports motivation. The significant level is (r = -.741); however, The findings confirmed that the coach’s power, authority, decision-making position, the threat of rejection on the refusal of sexual cooperation, the ready availability of inexperienced female athletes, and lack of implication of policies regarding sexual misconducts in public sector universities decline motivation of female athletes witnessed. Based on the findings, the study recommended that the family background, career history, and participation record of coaches should be investigated to ensure that they have ever been involved in any criminal activity or sexual misconduct during their career or participation.Keywords: abusive, athlete, coach, motivation
Procedia PDF Downloads 3374015 Evaluation of Systemic Immune-Inflammation Index in Obese Children
Authors: Mustafa M. Donma, Orkide Donma
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A growing list of cancers might be influenced by obesity. Obesity is associated with an increased risk for the occurrence and development of some cancers. Inflammation can lead to cancer. It is one of the characteristic features of cancer and plays a critical role in cancer development. C-reactive protein (CRP) is under evaluation related to the new and simple prognostic factors in patients with metastatic renal cell cancer. Obesity can predict and promote systemic inflammation in healthy adults. BMI is correlated with hs-CRP. In this study, SII index and CRP values were evaluated in children with normal BMI and those within the range of different obesity grades to detect the tendency towards cancer in pediatric obesity. A total of one hundred and ninety-four children; thirty-five children with normal BMI, twenty overweight (OW), forty-seven obese (OB) and ninety-two morbid obese (MO) participated in the study. Age- and sex-matched groups were constituted using BMI-for age percentiles. Informed consent was obtained. Ethical Committee approval was taken. Weight, height, waist circumference (C), hip C, head C and neck C of the children were measured. The complete blood count test was performed. C-reactive protein analysis was performed. Statistical analyses were performed using SPSS. The degree for statistical significance was p≤0.05. SII index values were progressively increasing starting from normal weight (NW) to MO children. There is a statistically significant difference between NW and OB as well as MO children. No significant difference was observed between NW and OW children, however, a correlation was observed between NW and OW children. MO constitutes the only group, which exhibited a statistically significant correlation between SII index and CRP. Obesity-related bladder, kidney, cervical, liver, colorectal, endometrial cancers are still being investigated. Obesity, characterized as a chronic low-grade inflammation, is a crucial risk factor for colon cancer. Elevated childhood BMI values may be indicative of processes leading to cancer, initiated early in life. Prevention of childhood adiposity may decrease the cancer incidence in adults. To authors’ best knowledge, this study is the first to introduce SII index values during obesity of varying degrees of severity. It is suggested that this index seems to affect all stages of obesity with an increasing tendency and may point out the concomitant status of obesity and cancer starting from very early periods of life.Keywords: children, C-reactive protein, systemic immune-inflammation index, obesity
Procedia PDF Downloads 1804014 Sol-Gel Synthesis and Photoluminescent Properties of YPO4: Pr3+ Nanophosphors
Authors: Badis Kahouadji, Lakhdar Guerbous, Lyes Lamiri
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For many years, the luminescent materials were investigated principally in the infrared and visible areas, because the ultraviolet (UV) and especially in vacuum Ultraviolet (VUV) are technically more difficult to explore, especially absence of applications requiring of materials suitable to short wavelengths.Recent necessary, related to the development of certain technologies, encouraged research in these spectra domains. It is in this context that the 4Fn-4Fn-1 5d transitions of rare earth in insulating materials, lying in the UV and VUV, are the aim of large number of studies. These studies relate in particular to search for new scintillator materials used for spectroscopy and X-ray, ɤ, as well as medical imaging. The 4Fn- 4Fn-15d transitions of the rare earth dependent to the host-matrix, several matrices ions were used to study these transitions, in this work we are suggeting to study on a very specific class of inorganic scintillators that are orthophosphate doped with rare earth ions, this study focused on the Pr3+ concentration on the structural and optical properties of Pr3+ doped YPO4 (yttriumorthophosphate) with powder form prepared by the Sol Gel method.Keywords: rare earth, scintillator, YPO4:Pr3+ nanophosphors, sol gel, 4Fn-4Fn-15d transitions
Procedia PDF Downloads 6044013 Morphological Features Fusion for Identifying INBREAST-Database Masses Using Neural Networks and Support Vector Machines
Authors: Nadia el Atlas, Mohammed el Aroussi, Mohammed Wahbi
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In this paper a novel technique of mass characterization based on robust features-fusion is presented. The proposed method consists of mainly four stages: (a) the first phase involves segmenting the masses using edge information’s. (b) The second phase is to calculate and fuse the most relevant morphological features. (c) The last phase is the classification step which allows us to classify the images into benign and malignant masses. In this step we have implemented Support Vectors Machines (SVM) and Artificial Neural Networks (ANN), which were evaluated with the following performance criteria: confusion matrix, accuracy, sensitivity, specificity, receiver operating characteristic ROC, and error histogram. The effectiveness of this new approach was evaluated by a recently developed database: INBREAST database. The fusion of the most appropriate morphological features provided very good results. The SVM gives accuracy to within 64.3%. Whereas the ANN classifier gives better results with an accuracy of 97.5%.Keywords: breast cancer, mammography, CAD system, features, fusion
Procedia PDF Downloads 6014012 Circle Work as a Relational Praxis to Facilitate Collaborative Learning within Higher Education: A Decolonial Pedagogical Framework for Teaching and Learning in the Virtual Classroom
Authors: Jennifer Nutton, Gayle Ployer, Ky Scott, Jenny Morgan
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Working in a circle within higher education creates a decolonial space of mutual respect, responsibility, and reciprocity that facilitates collaborative learning and deep connections among learners and instructors. This approach is beyond simply facilitating a group in a circle but opens the door to creating a sacred space connecting each member to the land, to the Indigenous peoples who have taken care of the lands since time immemorial, to one another, and to one’s own positionality. These deep connections not only center human knowledges and relationships but also acknowledges responsibilities to land. Working in a circle as a relational pedagogical praxis also disrupts institutional power dynamics by creating a space of collaborative learning and deep connections in the classroom. Inherent within circle work is to facilitate connections not just academically but emotionally, physically, culturally, and spiritually. Recent literature supports the use of online talking circles, finding that it can offer a more relational and experiential learning environment, which is often absent in the virtual world and has been made more evident and necessary since the pandemic. These deeper experiences of learning and connection, rooted in both knowledge and the land, can then be shared with openness and vulnerability with one another, facilitating growth and change. This process of beginning with the land is critical to ensure we have the grounding to obstruct the ongoing realities of colonialism. The authors, who identify as both Indigenous and non-Indigenous, as both educators and learners, reflect on their teaching and learning experiences in circle. They share a relational pedagogical praxis framework that has been successful in educating future social workers, environmental activists, and leaders in social and human services, health, legal and political fields.Keywords: circle work, relational pedagogies, decolonization, distance education
Procedia PDF Downloads 764011 Direct Blind Separation Methods for Convolutive Images Mixtures
Authors: Ahmed Hammed, Wady Naanaa
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In this paper, we propose a general approach to deal with the problem of a convolutive mixture of images. We use a direct blind source separation method by adding only one non-statistical justified constraint describing the relationships between different mixing matrix at the aim to make its resolution easy. This method can be applied, provided that this constraint is known, to degraded document affected by the overlapping of text-patterns and images. This is due to chemical and physical reactions of the materials (paper, inks,...) occurring during the documents aging, and other unpredictable causes such as humidity, microorganism infestation, human handling, etc. We will demonstrate that this problem corresponds to a convolutive mixture of images. Subsequently, we will show how the validation of our method through numerical examples. We can so obtain clear images from unreadable ones which can be caused by pages superposition, a phenomenon similar to that we find every often in archival documents.Keywords: blind source separation, convoluted mixture, degraded documents, text-patterns overlapping
Procedia PDF Downloads 3234010 The Combined Effect of Different Levels of Fe(III) in Diet and Cr(III) Supplementation on the Ca Status in Wistar
Authors: Staniek Halina
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The inappropriate trace elements supply such as iron(III) and chromium(III) may be risk factors of many metabolic disorders (e.g., anemia, diabetes, as well cause toxic effect). However, little is known about their mutual interactions and their impact on these disturbances. The effects of Cr(III) supplementation with a deficit or excess supply of Fe(III) in vivo conditions are not known yet. The objective of the study was to investigate the combined effect of different Fe(III) levels in the diet and simultaneous Cr(III) supplementation on the Ca distribution in organs in healthy rats. The assessment was based on a two-factor (2x3) experiment carried out on 54 female Wistar rats (Rattus norvegicus). The animals were randomly divided into 9 groups and for 6 weeks, they were fed semi-purified diets AIN-93 with three different Fe(III) levels in the diet as a factor A [control (C) 45 mg/kg (100% Recommended Daily Allowance for rodents), deficient (D) 5 mg/kg (10% RDA), and oversupply (H) 180 mg/kg (400% RDA)]. The second factor (B) was the simultaneous dietary supplementation with Cr(III) at doses of 1, 50 and 500 mg/kg of the diet. Iron(III) citrate was the source of Fe(III). The complex of Cr(III) with propionic acid, also called Cr₃ or chromium(III) propionate (CrProp), was used as a source of Cr(III) in the diet. The Ca content of analysed samples (liver, kidneys, spleen, heart, and femur) was determined with the Atomic Absorption Spectrometry (AAS) method. It was found that different dietary Fe(III) supply as well as Cr(III) supplementation independently and in combination influenced Ca metabolism in healthy rats. Regardless of the supplementation of Cr(III), the oversupply of Fe(III) (180 mg/kg) decreased the Ca content in the liver and kidneys, while it increased the Ca saturation of bone tissue. High Cr(III) doses lowered the hepatic Ca content. Moreover, it tended to decrease the Ca content in the kidneys and heart, but this effect was not statistically significant. The combined effect of the experimental factors on the Ca content in the liver and the femur was observed. With the increase in the Fe(III) content in the diet, there was a decrease in the Ca level in the liver and an increase in bone saturation, and the additional Cr(III) supplementation intensified those effects. The study proved that the different Fe(III) content in the diet, independently and in combination with Cr(III) supplementation, affected the Ca distribution in organisms of healthy rats.Keywords: calcium, chromium(III), iron(III), rats, supplementation
Procedia PDF Downloads 1994009 Corruption, Institutional Quality and Economic Growth in Nigeria
Authors: Ogunlana Olarewaju Fatai, Kelani Fatai Adeshina
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The interplay of corruption and institutional quality determines how effective and efficient an economy progresses. An efficient institutional quality is a key requirement for economic stability. Institutional quality in most cases has been used interchangeably with Governance and these have given room for proxies that legitimized Governance as measures for institutional quality. A poorly-tailored institutional quality has a penalizing effect on corruption and economic growth, while defective institutional quality breeds corruption. Corruption is a hydra-headed phenomenon as it manifests in different forms. The most celebrated definition of corruption is given as “the use or abuse of public office for private benefits or gains”. It also denotes an arrangement between two mutual parties in the determination and allocation of state resources for pecuniary benefits to circumvent state efficiency. This study employed Barro (1990) type augmented model to analyze the nexus among corruption, institutional quality and economic growth in Nigeria using annual time series data, which spanned the period 1996-2019. Within the analytical framework of Johansen Cointegration technique, Error Correction Mechanism (ECM) and Granger Causality tests, findings revealed a long-run relationship between economic growth, corruption and selected measures of institutional quality. The long run results suggested that all the measures of institutional quality except voice & accountability and regulatory quality are positively disposed to economic growth. Moreover, the short-run estimation indicated a reconciliation of the divergent views on corruption which pointed at “sand the wheel” and “grease the wheel” of growth. In addition, regulatory quality and the rule of law indicated a negative influence on economic growth in Nigeria. Government effectiveness and voice & accountability, however, indicated a positive influence on economic growth. The Granger causality test results suggested a one-way causality between GDP and Corruption and also between corruption and institutional quality. Policy implications from this study pointed at checking corruption and streamlining institutional quality framework for better and sustained economic development.Keywords: institutional quality, corruption, economic growth, public policy
Procedia PDF Downloads 1724008 Investigations on Microstructural and Raman Scattering Properties of B2O3 Doped Ba(Ti1-xZrx)O3 Nanoceramics
Authors: Keri̇m Emre Öksüz, Şaduman Şen, Uğur Şen
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0.5 wt. % B2O3–doped Ba (Ti1-xZrx) O3, (x=0-0.4) lead-free nanoceramics were synthesized using the solid-state reaction method by adopting the ball milling technique. The influence of the substitution content on crystallographic structure, phase transition, microstructure and sintering behaviour of BT and BZT ceramics were investigated. XRD analysis at room temperature revealed a structural transformation from tetragonal to rhombohedral with enhancement of ZrO2 content in the barium titanate matrix. The scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to investigate microstructure and surface morphology of the sintered samples. The evolution of the Raman spectra was studied for various compositions, and the spectroscopic signature of the corresponding phase was determined. Scanning Electron Microscope (SEM) observations revealed enhanced microstructural uniformity and retarded grain growth with increasing Zr content.Keywords: BaTiO3, barium-titanate-zirconate, nanoceramics, raman spectroscopy
Procedia PDF Downloads 3444007 Counting People Utilizing Space-Time Imagery
Authors: Ahmed Elmarhomy, K. Terada
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An automated method for counting passerby has been proposed using virtual-vertical measurement lines. Space-time image is representing the human regions which are treated using the segmentation process. Different color space has been used to perform the template matching. A proper template matching has been achieved to determine direction and speed of passing people. Distinguish one or two passersby has been investigated using a correlation between passerby speed and the human-pixel area. Finally, the effectiveness of the presented method has been experimentally verified.Keywords: counting people, measurement line, space-time image, segmentation, template matching
Procedia PDF Downloads 454