Search results for: toxicity characteristic leaching procedure
359 Quantifying the Aspect of ‘Imagining’ in the Map of Dialogical inquiry
Authors: Chua Si Wen Alicia, Marcus Goh Tian Xi, Eunice Gan Ghee Wu, Helen Bound, Lee Liang Ying, Albert Lee
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In a world full of rapid changes, people often need a set of skills to help them navigate an ever-changing workscape. These skills, often known as “future-oriented skills,” include learning to learn, critical thinking, understanding multiple perspectives, and knowledge creation. Future-oriented skills are typically assumed to be domain-general, applicable to multiple domains, and can be cultivated through a learning approach called Dialogical Inquiry. Dialogical Inquiry is known for its benefits of making sense of multiple perspectives, encouraging critical thinking, and developing learner’s capability to learn. However, it currently exists as a quantitative tool, which makes it hard to track and compare learning processes over time. With these concerns, the present research aimed to develop and validate a quantitative tool for the Map of Dialogical Inquiry, focusing Imagining aspect of learning. The Imagining aspect four dimensions: 1) speculative/ look for alternatives, 2) risk taking/ break rules, 3) create/ design, and 4) vision/ imagine. To do so, an exploratory literature review was conducted to better understand the dimensions of Imagining. This included deep-diving into the history of the creation of the Map of Dialogical Inquiry and a review on how “Imagining” has been conceptually defined in the field of social psychology, education, and beyond. Then, we synthesised and validated scales. These scales measured the dimension of Imagination and related concepts like creativity, divergent thinking regulatory focus, and instrumental risk. Thereafter, items were adapted from the aforementioned procured scales to form items that would contribute to the preliminary version of the Imagining Scale. For scale validation, 250 participants were recruited. A Confirmatory Factor Analysis (CFA) sought to establish dimensionality of the Imagining Scale with an iterative procedure in item removal. Reliability and validity of the scale’s dimensions were sought through measurements of Cronbach’s alpha, convergent validity, and discriminant validity. While CFA found that the distinction of Imagining’s four dimensions could not be validated, the scale was able to establish high reliability with a Cronbach alpha of .96. In addition, the convergent validity of the Imagining scale was established. A lack of strong discriminant validity may point to overlaps with other components of the Dialogical Map as a measure of learning. Thus, a holistic approach to forming the tool – encompassing all eight different components may be preferable.Keywords: learning, education, imagining, pedagogy, dialogical teaching
Procedia PDF Downloads 92358 Evaluation of Occupational Doses in Interventional Radiology
Authors: Fernando Antonio Bacchim Neto, Allan Felipe Fattori Alves, Maria Eugênia Dela Rosa, Regina Moura, Diana Rodrigues De Pina
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Interventional Radiology is the radiology modality that provides the highest dose values to medical staff. Recent researches show that personal dosimeters may underestimate dose values in interventional physicians, especially in extremities (hands and feet) and eye lens. The aim of this work was to study radiation exposure levels of medical staff in different interventional radiology procedures and estimate the annual maximum numbers of procedures (AMN) that each physician could perform without exceed the annual limits of dose established by normative. For this purpose LiF:Mg,Ti (TLD-100) dosimeters were positioned in different body regions of the interventional physician (eye lens, thyroid, chest, gonads, hand and foot) above the radiological protection vests as lead apron and thyroid shield. Attenuation values for lead protection vests were based on international guidelines. Based on these data were chosen as 90% attenuation of the lead vests and 60% attenuation of the protective glasses. 25 procedures were evaluated: 10 diagnostics, 10 angioplasty, and 5-aneurysm treatment. The AMN of diagnostic procedures was 641 for the primary interventional radiologist and 930 for the assisting interventional radiologist. For the angioplasty procedures, the AMN for primary interventional radiologist was 445 and for assisting interventional radiologist was 1202. As for the procedures of aneurism treatment, the AMN for the primary interventional radiologist was 113 and for the assisting interventional radiologist were 215. All AMN were limited by the eye lens doses already considering the use of protective glasses. In all categories evaluated, the higher dose values are found in gonads and in the lower regions of professionals, both for the primary interventionist and for the assisting, but the eyes lens dose limits are smaller than these regions. Additional protections as mobile barriers, which can be positioned between the interventionist and the patient, can decrease the exposures in the eye lens, providing a greater protection for the medical staff. The alternation of professionals to perform each type of procedure can reduce the dose values received by them over a period. The analysis of dose profiles proposed in this work showed that personal dosimeters positioned in chest might underestimate dose values in other body parts of the interventional physician, especially in extremities and eye lens. As each body region of the interventionist is subject to different levels of exposure, dose distribution in each region provides a better approach to what actions are necessary to ensure the radiological protection of medical staff.Keywords: interventional radiology, radiation protection, occupationally exposed individual, hemodynamic
Procedia PDF Downloads 393357 One Pot Synthesis of Cu–Ni–S/Ni Foam for the Simultaneous Removal and Detection of Norfloxacin
Authors: Xincheng Jiang, Yanyan An, Yaoyao Huang, Wei Ding, Manli Sun, Hong Li, Huaili Zheng
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The residual antibiotics in the environment will pose a threat to the environment and human health. Thus, efficient removal and rapid detection of norfloxacin (NOR) in wastewater is very important. The main sources of NOR pollution are the agricultural, pharmaceutical industry and hospital wastewater. The total consumption of NOR in China can reach 5440 tons per year. It is found that neither animals nor humans can totally absorb and metabolize NOR, resulting in the excretion of NOR into the environment. Therefore, residual NOR has been detected in water bodies. The hazards of NOR in wastewater lie in three aspects: (1) the removal capacity of the wastewater treatment plant for NOR is limited (it is reported that the average removal efficiency of NOR in the wastewater treatment plant is only 68%); (2) NOR entering the environment will lead to the emergence of drug-resistant strains; (3) NOR is toxic to many aquatic species. At present, the removal and detection technologies of NOR are applied separately, which leads to a cumbersome operation process. The development of simultaneous adsorption-flocculation removal and FTIR detection of pollutants has three advantages: (1) Adsorption-flocculation technology promotes the detection technology (the enrichment effect on the material surface improves the detection ability); (2) The integration of adsorption-flocculation technology and detection technology reduces the material cost and makes the operation easier; (3) FTIR detection technology endows the water treatment agent with the ability of molecular recognition and semi-quantitative detection for pollutants. Thus, it is of great significance to develop a smart water treatment material with high removal capacity and detection ability for pollutants. This study explored the feasibility of combining NOR removal method with the semi-quantitative detection method. A magnetic Cu-Ni-S/Ni foam was synthesized by in-situ loading Cu-Ni-S nanostructures on the surface of Ni foam. The novelty of this material is the combination of adsorption-flocculation technology and semi-quantitative detection technology. Batch experiments showed that Cu-Ni-S/Ni foam has a high removal rate of NOR (96.92%), wide pH adaptability (pH=4.0-10.0) and strong ion interference resistance (0.1-100 mmol/L). According to the Langmuir fitting model, the removal capacity can reach 417.4 mg/g at 25 °C, which is much higher than that of other water treatment agents reported in most studies. Characterization analysis indicated that the main removal mechanisms are surface complexation, cation bridging, electrostatic attraction, precipitation and flocculation. Transmission FTIR detection experiments showed that NOR on Cu-Ni-S/Ni foam has easily recognizable FTIR fingerprints; the intensity of characteristic peaks roughly reflects the concentration information to some extent. This semi-quantitative detection method has a wide linear range (5-100 mg/L) and a low limit of detection (4.6 mg/L). These results show that Cu-Ni-S/Ni foam has excellent removal performance and semi-quantitative detection ability of NOR molecules. This paper provides a new idea for designing and preparing multi-functional water treatment materials to achieve simultaneous removal and semi-quantitative detection of organic pollutants in water.Keywords: adsorption-flocculation, antibiotics detection, Cu-Ni-S/Ni foam, norfloxacin
Procedia PDF Downloads 76356 Islam, Gender and Education in Contemporary Georgia: The Example of Kvemo Kartli
Authors: N. Gelovani, D. Ismailov, S. Bochorishvili
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Religious minorities of Georgia include Muslims. Their composition is sufficiently miscellaneous, enclosing both ethnical viewpoint and belonging to the inner Islamic denomination. A majority of Muslims represent Azerbaijanis, who chiefly live in Kvemo Kartli (Bolnisi, Gardabani, Dmanisi, Tetri Tskaro, Marneuli and Tsalka). The catalyst for researchers of Islamic History is the geopolitical interests of Georgia, centuries-old contacts with the Islamic world, the not entirely trivial portion of Islam confessor population, the increasing influence of the Islamic factor in current religious-political processes in the world, the elevating procedure of Muslim religious self-consciousness in the Post-Soviet states, significant challenges of international terrorism, and perspectives of rapid globalization. The rise in the level of religious identity of Muslim citizens of Georgia (first of all of those who are not ethnic Georgians) is noticeable. New mosques have been constructed and, sometimes, even young people are being sent to the religious educational institutions of Muslim countries to gain a higher Islamic education. At a time when gender studies are substantive, the goal of which is to eliminate gender-based discrimination and violence in societies, it is essential in Georgia to conduct researches around the concrete problem – Islamic tradition, woman and education in Georgia. A woman’s right to education is an important indicator of women’s general status in a society. The appropriate resources, innovative analysis of Georgian ethnological materials, and surveying of the population (quantitative and qualitative research reports, working papers), condition the success of these researches. In the presented work, interrelation matters of Islam, gender and education in contemporary Georgia by the example of the Azerbaijani population in Kvemo Kartli during period 1992-2016 are studied. We researched the history of Muslim religious education centers in Tbilisi and Kvemo Kartli (Bolnisi, Gardabani, Dmanisi, Tetri Tskaro, Marneuli and Tsalka) in 1992-2016, on the one hand, and the results of sociological interrogation, on the other. As a result of our investigation, we found that Azeri women in the Kvemo Kartli (Georgia) region mostly receive their education in Georgia and Azerbaijan. Educational and Cultural Institutions are inaccessible for most Azeri women. The main reasons are the absence of educational and religious institutions at their places of residence and state policies towards Georgia’s Muslims.Keywords: Islam, gender, Georgia, education
Procedia PDF Downloads 227355 Stress Corrosion Crackings Test of Candidate Materials in Support of the Development of the European Small Modular Supercritical Water Cooled Rector Concept
Authors: Radek Novotny, Michal Novak, Daniela Marusakova, Monika Sipova, Hugo Fuentes, Peter Borst
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This research has been conducted within the European HORIZON 2020 project ECC-SMART. The main objective is to assess whether it is feasible to design and develop a small modular reactor (SMR) that would be cooled by supercritical water (SCW). One of the main objectives for material research concerns the corrosion of the candidate cladding materials. The experimental part has been conducted in support of the qualification procedure of the future SCW-SMR constructional materials. The last objective was to identify the gaps in current norms and guidelines. Apart from corrosion, resistance testing of candidate materials stresses corrosion cracking susceptibility tests have been performed in supercritical water. This paper describes part of these tests, in particular, those slow strain rate tensile loading applied for tangential ring shape specimens of two candidate materials, Alloy 800H and 310S stainless steel. These ring tensile tests are one the methods used for tensile testing of nuclear cladding. Here full circular heads with dimensions roughly equal to the inner diameter of the sample and the gage sections are placed in the parallel direction to the applied load. Slow strain rate tensile tests have been conducted in 380 or 500oC supercritical water applying two different elongation rates, 1x10-6 and 1x10-7 s-1. The effect of temperature and dissolved oxygen content on the SCC susceptibility of Alloy 800H and 310S stainless steel was investigated when two different temperatures and concentrations of dissolved oxygen were applied in supercritical water. The post-fracture analysis includes fractographic analysis of the fracture surfaces using SEM as well as cross-sectional analysis on the occurrence of secondary cracks. Assessment of the effect of environment and dissolved oxygen content was by comparing to the results of the reference tests performed in air and N2 gas overpressure. The effect of high temperature on creep and its role in the initiation of SCC was assessed as well. It has been concluded that the applied test method could be very useful for the investigation of stress corrosion cracking susceptibility of candidate cladding materials in supercritical water.Keywords: stress corrosion cracking, ring tensile tests, super-critical water, alloy 800H, 310S stainless steel
Procedia PDF Downloads 87354 Multi-Objective Optimization of the Thermal-Hydraulic Behavior for a Sodium Fast Reactor with a Gas Power Conversion System and a Loss of off-Site Power Simulation
Authors: Avent Grange, Frederic Bertrand, Jean-Baptiste Droin, Amandine Marrel, Jean-Henry Ferrasse, Olivier Boutin
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CEA and its industrial partners are designing a gas Power Conversion System (PCS) based on a Brayton cycle for the ASTRID Sodium-cooled Fast Reactor. Investigations of control and regulation requirements to operate this PCS during operating, incidental and accidental transients are necessary to adapt core heat removal. To this aim, we developed a methodology to optimize the thermal-hydraulic behavior of the reactor during normal operations, incidents and accidents. This methodology consists of a multi-objective optimization for a specific sequence, whose aim is to increase component lifetime by reducing simultaneously several thermal stresses and to bring the reactor into a stable state. Furthermore, the multi-objective optimization complies with safety and operating constraints. Operating, incidental and accidental sequences use specific regulations to control the thermal-hydraulic reactor behavior, each of them is defined by a setpoint, a controller and an actuator. In the multi-objective problem, the parameters used to solve the optimization are the setpoints and the settings of the controllers associated with the regulations included in the sequence. In this way, the methodology allows designers to define an optimized and specific control strategy of the plant for the studied sequence and hence to adapt PCS piloting at its best. The multi-objective optimization is performed by evolutionary algorithms coupled to surrogate models built on variables computed by the thermal-hydraulic system code, CATHARE2. The methodology is applied to a loss of off-site power sequence. Three variables are controlled: the sodium outlet temperature of the sodium-gas heat exchanger, turbomachine rotational speed and water flow through the heat sink. These regulations are chosen in order to minimize thermal stresses on the gas-gas heat exchanger, on the sodium-gas heat exchanger and on the vessel. The main results of this work are optimal setpoints for the three regulations. Moreover, Proportional-Integral-Derivative (PID) control setting is considered and efficient actuators used in controls are chosen through sensitivity analysis results. Finally, the optimized regulation system and the reactor control procedure, provided by the optimization process, are verified through a direct CATHARE2 calculation.Keywords: gas power conversion system, loss of off-site power, multi-objective optimization, regulation, sodium fast reactor, surrogate model
Procedia PDF Downloads 308353 The Study of Adsorption of RuP onto TiO₂ (110) Surface Using Photoemission Deposited by Electrospray
Authors: Tahani Mashikhi
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Countries worldwide rely on electric power as a critical economic growth and progress factor. Renewable energy sources, often referred to as alternative energy sources, such as wind, solar energy, geothermal energy, biomass, and hydropower, have garnered significant interest in response to the rising consumption of fossil fuels. Dye-sensitized solar cells (DSSCs) are a highly promising alternative for energy production as they possess numerous advantages compared to traditional silicon solar cells and thin-film solar cells. These include their low cost, high flexibility, straightforward preparation methodology, ease of production, low toxicity, different colors, semi-transparent quality, and high power conversion efficiency. A solar cell, also known as a photovoltaic cell, is a device that converts the energy of light from the sun into electrical energy through the photovoltaic effect. The Gratzel cell is the initial dye-sensitized solar cell made from colloidal titanium dioxide. The operational mechanism of DSSCs relies on various key elements, such as a layer composed of wide band gap semiconducting oxide materials (e.g. titanium dioxide [TiO₂]), as well as a photosensitizer or dye that absorbs sunlight to inject electrons into the conduction band, the electrolyte utilizes the triiodide/iodide redox pair (I− /I₃−) to regenerate dye molecules and a counter electrode made of carbon or platinum facilitates the movement of electrons across the circuit. Electrospray deposition permits the deposition of fragile, non-volatile molecules in a vacuum environment, including dye sensitizers, complex molecules, nanoparticles, and biomolecules. Surface science techniques, particularly X-ray photoelectron spectroscopy, are employed to examine dye-sensitized solar cells. This study investigates the possible application of electrospray deposition to build high-quality layers in situ in a vacuum. Two distinct categories of dyes can be employed as sensitizers in DSSCs: organometallic semiconductor sensitizers and purely organic dyes. Most organometallic dyes, including Ru533, RuC, and RuP, contain a ruthenium atom, which is a rare element. This ruthenium atom enhances the efficiency of dye-sensitized solar cells (DSSCs). These dyes are characterized by their high cost and typically appear as dark purple powders. On the other hand, organic dyes, such as SQ2, RK1, D5, SC4, and R6, exhibit reduced efficacy due to the lack of a ruthenium atom. These dyes appear in green, red, orange, and blue powder-colored. This study will specifically concentrate on metal-organic dyes. The adsorption of dye molecules onto the rutile TiO₂ (110) surface has been deposited in situ under ultra-high vacuum conditions by combining an electrospray deposition method with X-ray photoelectron spectroscopy. The X-ray photoelectron spectroscopy (XPS) technique examines chemical bonds and interactions between molecules and TiO₂ surfaces. The dyes were deposited at varying times, from 5 minutes to 40 minutes, to achieve distinct layers of coverage categorized as sub-monolayer, monolayer, few layers, or multilayer. Based on the O 1s photoelectron spectra data, it can be observed that the monolayer establishes a strong chemical bond with the Ti atoms of the oxide substrate by deprotonating the carboxylic acid groups through 2M-bidentate bridging anchors. The C 1s and N 1s photoelectron spectra indicate that the molecule remains intact at the surface. This can be due to the existence of all functional groups and a ruthenium atom, where the binding energy of Ru 3d is consistent with Ru2+.Keywords: deposit, dye, electrospray, TiO₂, XPS
Procedia PDF Downloads 45352 Comparison between Photogrammetric and Structure from Motion Techniques in Processing Unmanned Aerial Vehicles Imageries
Authors: Ahmed Elaksher
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Over the last few years, significant progresses have been made and new approaches have been proposed for efficient collection of 3D spatial data from Unmanned aerial vehicles (UAVs) with reduced costs compared to imagery from satellite or manned aircraft. In these systems, a low-cost GPS unit provides the position, velocity of the vehicle, a low-quality inertial measurement unit (IMU) determines its orientation, and off-the-shelf cameras capture the images. Structure from Motion (SfM) and photogrammetry are the main tools for 3D surface reconstruction from images collected by these systems. Unlike traditional techniques, SfM allows the computation of calibration parameters using point correspondences across images without performing a rigorous laboratory or field calibration process and it is more flexible in that it does not require consistent image overlap or same rotation angles between successive photos. These benefits make SfM ideal for UAVs aerial mapping. In this paper, a direct comparison between SfM Digital Elevation Models (DEM) and those generated through traditional photogrammetric techniques was performed. Data was collected by a 3DR IRIS+ Quadcopter with a Canon PowerShot S100 digital camera. Twenty ground control points were randomly distributed on the ground and surveyed with a total station in a local coordinate system. Images were collected from an altitude of 30 meters with a ground resolution of nine mm/pixel. Data was processed with PhotoScan, VisualSFM, Imagine Photogrammetry, and a photogrammetric algorithm developed by the author. The algorithm starts with performing a laboratory camera calibration then the acquired imagery undergoes an orientation procedure to determine the cameras’ positions and orientations. After the orientation is attained, correlation based image matching is conducted to automatically generate three-dimensional surface models followed by a refining step using sub-pixel image information for high matching accuracy. Tests with different number and configurations of the control points were conducted. Camera calibration parameters estimated from commercial software and those obtained with laboratory procedures were comparable. Exposure station positions were within less than few centimeters and insignificant differences, within less than three seconds, among orientation angles were found. DEM differencing was performed between generated DEMs and few centimeters vertical shifts were found.Keywords: UAV, photogrammetry, SfM, DEM
Procedia PDF Downloads 294351 The Impact of Undisturbed Flow Speed on the Correlation of Aerodynamic Coefficients as a Function of the Angle of Attack for the Gyroplane Body
Authors: Zbigniew Czyz, Krzysztof Skiba, Miroslaw Wendeker
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This paper discusses the results of aerodynamic investigation of the Tajfun gyroplane body designed by a Polish company, Aviation Artur Trendak. This gyroplane has been studied as a 1:8 scale model. Scaling objects for aerodynamic investigation is an inherent procedure in any kind of designing. If scaling, the criteria of similarity need to be satisfied. The basic criteria of similarity are geometric, kinematic and dynamic. Despite the results of aerodynamic research are often reduced to aerodynamic coefficients, one should pay attention to how values of coefficients behave if certain criteria are to be satisfied. To satisfy the dynamic criterion, for example, the Reynolds number should be focused on. This is the correlation of inertial to viscous forces. With the multiplied flow speed by the specific dimension as a numerator (with a constant kinematic viscosity coefficient), flow speed in a wind tunnel research should be increased as many times as an object is decreased. The aerodynamic coefficients specified in this research depend on the real forces that act on an object, its specific dimension, medium speed and variations in its density. Rapid prototyping with a 3D printer was applied to create the research object. The research was performed with a T-1 low-speed wind tunnel (its diameter of the measurement volume is 1.5 m) and a six-element aerodynamic internal scales, WDP1, at the Institute of Aviation in Warsaw. This T-1 wind tunnel is low-speed continuous operation with open space measurement. The research covered a number of the selected speeds of undisturbed flow, i.e. V = 20, 30 and 40 m/s, corresponding to the Reynolds numbers (as referred to 1 m) Re = 1.31∙106, 1.96∙106, 2.62∙106 for the angles of attack ranging -15° ≤ α ≤ 20°. Our research resulted in basic aerodynamic characteristics and observing the impact of undisturbed flow speed on the correlation of aerodynamic coefficients as a function of the angle of attack of the gyroplane body. If the speed of undisturbed flow in the wind tunnel changes, the aerodynamic coefficients are significantly impacted. At speed from 20 m/s to 30 m/s, drag coefficient, Cx, changes by 2.4% up to 9.9%, whereas lift coefficient, Cz, changes by -25.5% up to 15.7% if the angle of attack of 0° excluded or by -25.5% up to 236.9% if the angle of attack of 0° included. Within the same speed range, the coefficient of a pitching moment, Cmy, changes by -21.1% up to 7.3% if the angles of attack -15° and -10° excluded or by -142.8% up to 618.4% if the angle of attack -15° and -10° included. These discrepancies in the coefficients of aerodynamic forces definitely need to consider while designing the aircraft. For example, if load of certain aircraft surfaces is calculated, additional correction factors definitely need to be applied. This study allows us to estimate the discrepancies in the aerodynamic forces while scaling the aircraft. This work has been financed by the Polish Ministry of Science and Higher Education.Keywords: aerodynamics, criteria of similarity, gyroplane, research tunnel
Procedia PDF Downloads 393350 Concept of a Pseudo-Lower Bound Solution for Reinforced Concrete Slabs
Authors: M. De Filippo, J. S. Kuang
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In construction industry, reinforced concrete (RC) slabs represent fundamental elements of buildings and bridges. Different methods are available for analysing the structural behaviour of slabs. In the early ages of last century, the yield-line method has been proposed to attempt to solve such problem. Simple geometry problems could easily be solved by using traditional hand analyses which include plasticity theories. Nowadays, advanced finite element (FE) analyses have mainly found their way into applications of many engineering fields due to the wide range of geometries to which they can be applied. In such cases, the application of an elastic or a plastic constitutive model would completely change the approach of the analysis itself. Elastic methods are popular due to their easy applicability to automated computations. However, elastic analyses are limited since they do not consider any aspect of the material behaviour beyond its yield limit, which turns to be an essential aspect of RC structural performance. Furthermore, their applicability to non-linear analysis for modeling plastic behaviour gives very reliable results. Per contra, this type of analysis is computationally quite expensive, i.e. not well suited for solving daily engineering problems. In the past years, many researchers have worked on filling this gap between easy-to-implement elastic methods and computationally complex plastic analyses. This paper aims at proposing a numerical procedure, through which a pseudo-lower bound solution, not violating the yield criterion, is achieved. The advantages of moment distribution are taken into account, hence the increase in strength provided by plastic behaviour is considered. The lower bound solution is improved by detecting over-yielded moments, which are used to artificially rule the moment distribution among the rest of the non-yielded elements. The proposed technique obeys Nielsen’s yield criterion. The outcome of this analysis provides a simple, yet accurate, and non-time-consuming tool of predicting the lower-bound solution of the collapse load of RC slabs. By using this method, structural engineers can find the fracture patterns and ultimate load bearing capacity. The collapse triggering mechanism is found by detecting yield-lines. An application to the simple case of a square clamped slab is shown, and a good match was found with the exact values of collapse load.Keywords: computational mechanics, lower bound method, reinforced concrete slabs, yield-line
Procedia PDF Downloads 178349 Influence of Urban Design on Pain and Disability in Women with Chronic Low Back Pain in Urban Cairo
Authors: Maha E. Ibrahim, Mona Abdel Aziz
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Background: Chronic low back pain (CLBP) in urban communities represents a challenge to healthcare systems worldwide. The traditional biomedical approach to back pain has been particularly inadequate. Failure of the biomedical model to explain the poor correlation between pain and disability on the one hand, and biological and physical factors that explain those symptoms on the other has led to the adoption of the biopsychosocial model, to recognize the reciprocal influence of physical, social and psychological factors implicated in CLBP, a condition that shows higher prevalence among women residing in urban areas. Urban design of the built community has been shown to exert a significant influence on physical and psychological health. However, little research has investigated the relationship between elements of the built environment, and the level of pain and disability of women with CLBP. As Egypt embarks on building a new capital city, and new settlements proliferate, better understanding of this relationship could greatly reduce the economic and human costs of this widespread medical problem for women. Methods: This study was designed as an exploratory mixed qualitative and quantitative study. Twenty-Six women with CLBP living in two neighborhoods in Cairo, different in their urban structure, but adjacent in their locations (Old Maadi and New Maadi) were interviewed using semi-structured interviews (8 from Old Maadi and 18 from New Maadi). Located in the South of Cairo, New Maadi is a neighborhood with the characteristic modern urban style (narrow streets and tall, adjacent buildings), while Old Maadi is known for being greener, quieter and more relaxed than the usual urban districts of Cairo. The interviews examined their perceptions of the built environment, including building shapes and colors and street light, as well as their sense of safety and comfort, and how it affects their physical and psychological health in general, and their back condition in particular. In addition, they were asked to rate their level of pain and to fill the Oswestry Disability Index (ODI), and the General Health Questionnaire (GHQ-12) to rate their level of disability and psychological status, respectively. Results: Women in both districts had moderate to severe pain and moderate disability with no significant differences between the two districts. However, those living in New Maadi had significantly worse scores on the GHQ-12 than those living in Old Maadi. Most women did not feel that specific elements of the built environment affected their back pain, however, they expressed distress of the elements that were ugly, distorted or damaged, especially where there were no ways of avoiding or fixing them. Furthermore, most women affirmed that the unsightly and uncomfortable elements of their neighborhoods affected their mood states and were a constant source of stress. Conclusion: This exploratory study concludes that elements of the urban built environment do not exert a direct effect on CLBP. However, the perception of women regarding these elements does affect their mood states, and their levels of stress, making them a possible indirect cause of increased suffering in these women.Keywords: built environment, chronic back pain, disability, urban Cairo
Procedia PDF Downloads 146348 NK Cells Expansion Model from PBMC Led to a Decrease of CD4+ and an Increase of CD8+ and CD25+CD127- T-Reg Lymphocytes in Patients with Ovarian Neoplasia
Authors: Rodrigo Fernandes da Silva, Daniela Maira Cardozo, Paulo Cesar Martins Alves, Sophie Françoise Derchain, Fernando Guimarães
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T-reg lymphocytes are important for the control of peripheral tolerance. They control the adaptive immune system and prevent autoimmunity through its suppressive action on CD4+ and CD8+ lymphocytes. The suppressive action also includes B lymphocytes, dendritic cells, monocytes/macrophages and recently, studies have shown that T-reg are also able to inhibit NK cells, therefore they exert their control of the immune response from innate to adaptive response. Most tumors express self-ligands, therefore it is believed that T-reg cells induce tolerance of the immune system, hindering the development of successful immunotherapies. T-reg cells have been linked to the suppression mechanisms of the immune response against tumors, including ovarian cancer. The goal of this study was to disclose the sub-population of the expanded CD3+ lymphocytes reported by previous studies, using the long-term culture model designed by Carlens et al 2001, to generate effector cell suspensions enriched with cytotoxic CD3-CD56+ NK cells, from PBMC of ovarian neoplasia patients. Methods and Results: Blood was collected from 12 patients with ovarian neoplasia after signed consent: 7 benign (Bng) and 5 malignant (Mlg). Mononuclear cells were separated by Ficoll-Paque gradient. Long-term culture was conducted by a 21 day culturing process with SCGM CellGro medium supplemented with anti-CD3 (10ng/ml, first 5 days), IL-2 (1000UI/ml) and FBS (10%). After 21 days of expansion, there was an increase in the population of CD3+ lymphocytes in the benign and malignant group. Within CD3+ population, there was a significant decrease in the population of CD4+ lymphocytes in the benign (median Bgn D-0=73.68%, D-21=21.05%) (p<0.05) and malignant (median Mlg D-0=64.00%, D-21=11.97%) (p < 0.01) group. Inversely, after 21 days of expansion, there was an increase in the population of CD8+ lymphocytes within the CD3+ population in the benign (median Bgn D-0=16.80%, D-21=38.56%) and malignant (median Mlg D-0=27.12%, D-21=72.58%) group. However, this increase was only significant on the malignant group (p<0.01). Within the CD3+CD4+ population, there was a significant increase (p < 0.05) in the population of T-reg lymphocytes in the benign (median Bgn D-0=9.84%, D-21=39.47%) and malignant (median Mlg D-0=3.56%, D-21=16.18%) group. Statistical analysis inter groups was performed by Kruskal-Wallis test and intra groups by Mann Whitney test. Conclusion: The CD4+ and CD8+ sub-population of CD3+ lymphocytes shifts with the culturing process. This might be due to the process of the immune system to produce a cytotoxic response. At the same time, T-reg lymphocytes increased within the CD4+ population, suggesting a modulation of the immune response towards cells of the immune system. The expansion of the T-reg population can hinder an immune response against cancer. Therefore, an immunotherapy using this expansion procedure should aim to halt the expansion of T-reg or its immunosuppresion capability.Keywords: regulatory T cells, CD8+ T cells, CD4+ T cells, NK cell expansion
Procedia PDF Downloads 451347 Comparative Hematological Analysis of Blood Profile in Experimentally Infected with Trichinella spiralis, Trichinella britovi and Trichinella pseudospiralis Mice
Authors: Valeria T. Dilcheva, Svetlozara L. Petkova, Ivelin Vladov
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Trichinellosis is a food-borne parasitic disease caused by nematodes of the genus Trichinella which are zoonotic parasites with cosmopolitan distribution and major socio-economic importance. Human infection is acquired through consumption of undercooked meat from domestic or wild animal. Penetration of Trichinella larvae into striated skeletal muscle cells results in ultrastructural and metabolic changes. Migration of larvae causes the typical symptoms and signs of the disease. The severity of the symptoms depends on the number of ingested Trichinella larvae and the immune response of the host. Eosinophilia is present, with few exceptions, in most cases of human trichinellosis, inasmuch as it is the earliest and most important host response. Even in human asymptomatic cases, increases in eosinophilia of up to 15% have been observed. Eosinophilia appears at an early stage of infection between the second and fifth weeks of infection. By 2005 it was considered that only two species of Trichinella genus were found in the country. After routine trichinelloscopy procedure disseminated single muscle larvae in samples of wild boars and badger were PCR-identified as T. pseudospiralis. The study aimed to observed hematological changes occurring during experimentally induced infection with Trichinella spiralis, T. britovi and T. pseudospiralis in mice. We performed hematological blood profile, tracking 15 blood indicators. In statistical analysis made by Two-way ANOVA, there were significant differences of HGB, MCHC, PLT, Lymph%, Gran% in all three types of trichinellosis compared to control animals. Capsule-forming T. spiralis showed statistically significant differences in HGB, MCHC, Lymph% and PLT compared to the other two species. Non capsule-forming T. pseudospiralis showed statistically significant differences in Lymph%, Gran% relative to the control and in Gran% relative to T. spiralis. It appears rather substantial the process of capsule formation for prolonged immune response and retention of high content of percentage of lymphocytes(Lymph%) and low of granulocyte(Gran%) in T. pseudospiralis, which is contrary to studies for T. spiralis and eosinophilia. Studies and analyzes of some specific blood profile parameters can provide additional data in favor of early diagnosis and adequate treatment as well as provide a better understanding of acute and chronic trichinosis.Keywords: hematological test, T. britovi, T. spiralis, T. pseudospiralis
Procedia PDF Downloads 173346 Towards a Mandatory Frame of ADR in Divorce Cases: Key Elements from a Comparative Perspective for Belgium
Authors: Celine Jaspers
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The Belgian legal system is slowly evolving to mandatory mediation to promote ADR. One of the reasons for this evolution is the lack of use of alternative methods in relation to their possible benefits. Especially in divorce cases, ADR can play a beneficial role in resolving disputes, since the emotional component is very much present. When children are involved, a solution provided by the parent may be more adapted to the child’s best interest than a court order. In the first part, the lack of use of voluntary ADR and the evolution toward mandatory ADR in Belgium will be indicated by sources of legislation, jurisprudence and social-scientific sources, with special attention to divorce cases. One of the reasons is lack of knowledge on ADR, despite the continuing efforts of the Belgian legislator to promote ADR. One of the last acts of ADR-promotion, was the implementation of an Act in 2018 which gives the judge the possibility to refer parties to mediation if at least one party wants to during the judicial procedure. This referral is subject to some conditions. The parties will be sent to a private mediator, recognized by the Federal Mediation Commission, to try to resolve their conflict. This means that at least one party can be mandated to try mediation (indicated as “semi-mandatory mediation”). The main goal is to establish the factors and elements that Belgium has to take into account in their further development of mandatory ADR, with consideration of the human rights perspective and the EU perspective. Furthermore it is also essential to detect some dangerous pitfalls other systems have encountered with their process design. Therefore, the second part, the comparative component, will discuss the existing framework in California, USA to establish the necessary elements, possible pitfalls and considerations the Belgian legislator can take into account when further developing the framework of mandatory ADR. The contrasting and functional method will be used to create key elements and possible pitfalls, to help Belgium improve its existing framework. The existing mandatory system in California has been in place since 1981 and is still up and running, and can thus provide valuable lessons and considerations for the Belgian system. Thirdly, the key elements from a human rights perspective and from a European Union perspective (e.g. the right to access to a judge, the right to privacy) will be discussed too, since the basic human rights and European legislation and jurisprudence play a significant part in Belgian legislation as well. The main sources for this part will be the international and European treaties, legislation, jurisprudence and soft law. In the last and concluding part, the paper will list the most important elements of a mandatory ADR-system design with special attention to the dangers of these elements (e.g. to include or exclude domestic violence cases in the mandatory ADR-framework and the consequences thereof), and with special attention for the necessary the international and European rights, prohibitions and guidelines.Keywords: Belgium, divorce, framework, mandatory ADR
Procedia PDF Downloads 155345 Evaluation of a Driver Training Intervention for People on the Autism Spectrum: A Multi-Site Randomized Control Trial
Authors: P. Vindin, R. Cordier, N. J. Wilson, H. Lee
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Engagement in community-based activities such as education, employment, and social relationships can improve the quality of life for individuals with Autism Spectrum Disorder (ASD). Community mobility is vital to attaining independence for individuals with ASD. Learning to drive and gaining a driver’s license is a critical link to community mobility; however, for individuals with ASD acquiring safe driving skills can be a challenging process. Issues related to anxiety, executive function, and social communication may affect driving behaviours. Driving training and education aimed at addressing barriers faced by learner drivers with ASD can help them improve their driving performance. A multi-site randomized controlled trial (RCT) was conducted to evaluate the effectiveness of an autism-specific driving training intervention for improving the on-road driving performance of learner drivers with ASD. The intervention was delivered via a training manual and interactive website consisting of five modules covering varying driving environments starting with a focus on off-road preparations and progressing through basic to complex driving skill mastery. Seventy-two learner drivers with ASD aged 16 to 35 were randomized using a blinded group allocation procedure into either the intervention or control group. The intervention group received 10 driving lessons with the instructors trained in the use of an autism-specific driving training protocol, whereas the control group received 10 driving lessons as usual. Learner drivers completed a pre- and post-observation drive using a standardized driving route to measure driving performance using the Driving Performance Checklist (DPC). They also completed anxiety, executive function, and social responsiveness measures. The findings showed that there were significant improvements in driving performance for both the intervention (d = 1.02) and the control group (d = 1.15). However, the differences were not significant between groups (p = 0.614) or study sites (p = 0.842). None of the potential moderator variables (anxiety, cognition, social responsiveness, and driving instructor experience) influenced driving performance. This study is an important step toward improving community mobility for individuals with ASD showing that an autism-specific driving training intervention can improve the driving performance of leaner drivers with ASD. It also highlighted the complexity of conducting a multi-site design even when sites were matched according to geography and traffic conditions. Driving instructors also need more and clearer information on how to communicate with learner drivers with restricted verbal expression.Keywords: autism spectrum disorder, community mobility, driving training, transportation
Procedia PDF Downloads 132344 [Keynote Talk]: Bioactive Cyclic Dipeptides of Microbial Origin in Discovery of Cytokine Inhibitors
Authors: Sajeli A. Begum, Ameer Basha, Kirti Hira, Rukaiyya Khan
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Cyclic dipeptides are simple diketopiperazine derivatives being investigated by several scientists for their biological effects which include anticancer, antimicrobial, haematological, anticonvulsant, immunomodulatory effect, etc. They are potentially active microbial metabolites having been synthesized too, for developing into drug candidates. Cultures of Pseudomonas species have earlier been reported to produce cyclic dipeptides, helping in quorum sensing signals and bacterial–host colonization phenomena during infections, causing cell anti-proliferation and immunosuppression. Fluorescing Pseudomonas species have been identified to secrete lipid derivatives, peptides, pyrroles, phenazines, indoles, aminoacids, pterines, pseudomonic acids and some antibiotics. In the present work, results of investigation on the cyclic dipeptide metabolites secreted by the culture broth of Pseudomonas species as potent pro-inflammatory cytokine inhibitors are discussed. The bacterial strain was isolated from the rhizospheric soil of groundnut crop and identified as Pseudomonas aeruginosa by 16S rDNA sequence (GenBank Accession No. KT625586). Culture broth of this strain was prepared by inoculating into King’s B broth and incubating at 30 ºC for 7 days. The ethyl acetate extract of culture broth was prepared and lyophilized to get a dry residue (EEPA). Lipopolysaccharide (LPS)-induced ELISA assay proved the inhibition of tumor necrosis factor-alpha (TNF-α) secretion in culture supernatant of RAW 264.7 cells by EEPA (IC50 38.8 μg/mL). The effect of oral administration of EEPA on plasma TNF-α level in rats was tested by ELISA kit. The LPS mediated plasma TNF-α level was reduced to 45% with 125 mg/kg dose of EEPA. Isolation of the chemical constituents of EEPA through column chromatography yielded ten cyclic dipeptides, which were characterized using nuclear magnetic resonance and mass spectroscopic techniques. These cyclic dipeptides are biosynthesized in microorganisms by multifunctional assembly of non-ribosomal peptide synthases and cyclic dipeptide synthase. Cyclo (Gly-L-Pro) was found to be more potentially (IC50 value 4.5 μg/mL) inhibiting TNF-α production followed by cyclo (trans-4-hydroxy-L-Pro-L-Phe) (IC50 value 14.2 μg/mL) and the effect was equal to that of standard immunosuppressant drug, prednisolone. Further, the effect was analyzed by determining mRNA expression of TNF-α in LPS-stimulated RAW 264.7 macrophages using quantitative real-time reverse transcription polymerase chain reaction. EEPA and isolated cyclic dipeptides demonstrated diminution of TNF-α mRNA expression levels in a dose-dependent manner under the tested conditions. Also, they were found to control the expression of other pro-inflammatory cytokines like IL-1β and IL-6, when tested through their mRNA expression levels in LPS-stimulated RAW 264.7 macrophages under LPS-stimulated conditions. In addition, significant inhibition effect was found on Nitric oxide production. Further all the compounds exhibited weak toxicity to LPS-induced RAW 264.7 cells. Thus the outcome of the study disclosed the effectiveness of EEPA and the isolated cyclic dipeptides in down-regulating key cytokines involved in pathophysiology of autoimmune diseases.In another study led by the investigators, microbial cyclic dipeptides were found to exhibit excellent antimicrobial effect against Fusarium moniliforme which is an important causative agent of Sorghum grain mold disease. Thus, cyclic dipeptides are emerging small molecular drug candidates for various autoimmune diseases.Keywords: cyclic dipeptides, cytokines, Fusarium moniliforme, Pseudomonas, TNF-alpha
Procedia PDF Downloads 211343 Thyroid Cancer Treatment in Yemen Under Blockade Conditions and Absence of Radioactive Iodine
Authors: Anis Al-Yakhiri
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Introduction: The World Health Organization (WHO) classifies malignant epithelial thyroid tumors into four major groups (papillary, follicular, medullar and undifferentiated) . Papillary thyroid carcinoma (PTC) is the most common type, for about eight out of ten thyroid cancers belong to this histological type. Radioactive iodine (RAI) is considered effective for patients with total or nearly total thyroidectomy, but the beneficial effects of RAI are still controversial. War conditions forced us to study alternative methods of using radioactive iodine in the treatment of patients with PTC. Material and methods: Between January 2014 and June 2021, in Al-Yakhiri hospital, 57 Total Thyroidectomy with Radical BilateralNeckDissection (RBND) were performed, 50 for malignant disease,7 for false positive cytology.RBND involves surgical clearance of Levels II-VI. Mean age was 40.7 years old and 92% of the patients were female. 7(14%) patients had hypothyroidism which required preoperative thyroid hormone treatment. The Thyroid Stimulating Hormone- Suppression Therapy (TSH-ST) immediately started after RBND for mostpatients on the first day. It consisted in reducing the level of TSH< 0.1 mIU/L. Results: The Apron flap was used on most operations (40)80% and with lateral extensions had 10(20%). RBND involves surgical clearance of Levels II-VI performed in all operated patients, besides that, 4(8%) of them had resection of sternocleidomastoid muscle (SCM) and accessory nerve (XIn) and internal jugular vein (IJV) withclearance of Levels IB. The PTC was the most common 80.9% (38 patients from 47)by histopathological report. and 4(8%) patients of 50 had resection of sternocleidomastoid muscle (SCM) and accessory nerve (XIn) and internal jugular vein (IJV). The postoperative mortality rate not observed (0%). The postoperative morbidity rate was 22.8% (n =13).Seroma(8.7%),Hypocalcimia(7%), Wound infection(5.3%), Bleeding(1.8%). To suppress TSH and growth of any residual thyroid theTSH-ST (levothyroxine150 – 600mcg)was performed in all patients 57(100%) on the first day afterRBND. We tracked the results of treatment for two years in 30 patients with PTC, only 3 of them received radioactive iodine abroad. Biennial Recurrence rate for PTC appeared in one woman (2%), who had RAI postoperatively in the form of neck lymph nodes metastasis. Conclusion: For patients with PTC, thyroidectomy plus prophylacticRBND is a safe and efficient procedure and it results in lower recurrence rate. Postoperative treatment with exogenous thyroid hormone in doses sufficient to suppress TSH (not less than 150mcg), decreases incidence of recurrence. Total Thyroidectomy with RBND followed by TSH-ST, in our opinion, applicable optimal treatment scheme care for this patient population.Keywords: thyroid cancer, Yemen war, absence of radioactive iodine, neck dissection, surgery results
Procedia PDF Downloads 81342 Bioincision of Gmelina Arborea Roxb. Heartwood with Inonotus Dryophilus (Berk.) Murr. for Improved Chemical Uptake and Penetration
Authors: A. O. Adenaiya, S. F. Curling, O. Y. Ogunsanwo, G . A. Ormondroyd
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Treatment of wood with chemicals in order to prolong its service life may prove difficult in some refractory wood species. This impermeability in wood is usually due to biochemical changes which occur during heartwood formation. Bioincision, which is a short-term, controlled microbial decomposition of wood, is one of the promising approaches capable of improving the amenability of refractory wood to chemical treatments. Gmelina Arborea, a mainstay timber species in Nigeria, has impermeable heartwood due to the excessive tyloses which occlude its vessels. Therefore, the chemical uptake and penetration in Gmelina arborea heartwood bioincised with Inonotus dryophilus fungus was investigated. Five mature Gmelina Arborea trees were harvested at the Departmental plantation in Ajibode, Ibadan, Nigeria and a bolt of 300 cm was obtained from the basal portion of each tree. The heartwood portion of the bolts was extracted and converted into dimensions 20 mm x 20 mm x 60 mm and subsequently conditioned (200C at 65% Relative Humidity). Twenty wood samples each were bioincised with the white-rot fungus Inonotus dryophilus (ID, 999) for 3, 5, 7 and 9 weeks using standard procedure, while a set of sterile control samples were prepared. Ten of each bioincised and control sample were pressure-treated with 5% tanalith preservative, while the other ten of each bioincised and control samples were pressure-treated with a liquid dye for easy traceability of the chemical in the wood, both using a full cell treatment process. The bioincised and control samples were evaluated for their Weight Loss before chemical treatment (WL, %), Preservative Absorption (PA, Kg/m3), Preservative Retention (PR, Kg/m3), Axial Absorption (AA, Kg/m3), Lateral Absorption (LA, Kg/m3), Axial Penetration Depth (APD, mm), Radial Penetration Depth (RPD, mm), and Tangential Penetration Depth (TPD, mm). The data obtained were analyzed using ANOVA at α0.05. Results show that the weight loss was least in the samples bioincised for three weeks (0.09%) and highest after 7 weeks of bioincision (0.48%). The samples bioincised for 3 weeks had the least PA (106.72 Kg/m3) and PR (5.87 Kg/m3), while the highest PA (134.9 Kg/m3) and PR were observed after 7 weeks of bioincision (7.42 Kg/m3). The AA ranged from 27.28 Kg/m3 (3 weeks) to 67.05 Kg/m3 (5 weeks), while the LA was least after 5 weeks of incubation (28.1 Kg/m3) and highest after 9 weeks (71.74 Kg/m3). Significantly lower APD was observed in control samples (6.97 mm) than in the samples bioincised after 9weeks (19.22 mm). The RPD increased from 0.08 mm (control samples) to 3.48 mm (5 weeks), while TPD ranged from 0.38 mm (control samples) to 0.63 mm (9 weeks), implying that liquid flow in the wood was predominantly through the axial pathway. Bioincising G. arborea heartwood with I. dryophilus fungus for 9 weeks is capable of enhancing chemical uptake and deeper penetration of chemicals in the wood through the degradation of the occluding vessel tyloses, which is accompanied by a minimal degradation of the polymeric wood constituents.Keywords: Bioincision, chemical uptake, penetration depth, refractory wood, tyloses
Procedia PDF Downloads 106341 Gender Bias and the Role It Plays in Student Evaluation of Instructors
Authors: B. Garfolo, L. Kelpsh, R. Roak, R. Kuck
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Often, student ratings of instructors play a significant role in the career path of an instructor in higher education. So then, how does a student view the effectiveness of instructor teaching? This question has been address by literally thousands of studies found in the literature. Yet, why does this question still persist? A literature review reveals that while it is true that student evaluations of instructors can be biased, there is still a considerable amount of work that needs to be done in understanding why. As student evaluations of instructors can be used in a variety of settings (formative or summative) it is critical to understand the nature of the bias. The authors believe that not only is some bias possible in student evaluations, it should be expected for the simple reason that a student evaluation is a human activity and as such, relies upon perception and interpersonal judgment. As such, student ratings are affected by the same factors that can potentially affect any rater’s judgment, such as stereotypes based on gender, culture, race, etc. Previous study findings suggest that student evaluations of teacher effectiveness differ between male and female raters. However, even though studies have shown that instructor gender does play an important role in influencing student ratings, the exact nature and extent of that role remains the subject of debate. Researchers, in their attempt to define good teaching, have looked for differences in student evaluations based on a variety of characteristics such as course type, class size, ability level of the student and grading practices in addition to instructor and student characteristics (gender, age, etc.) with inconsistent results. If a student evaluation represents more than an instructor’s teaching ability, for example, a physical characteristic such as gender, then this information must be taken into account if the evaluation is to have meaning with respect to instructor assessment. While the authors concede that it is difficult or nearly impossible to separate gender from student perception of teaching practices in person, it is, however, possible to shield an instructor’s gender identity with respect to an online teaching experience. The online teaching modality presents itself as a unique opportunity to experiment directly with gender identity. The analysis of the differences of online behavior of individuals when they perceive that they are interacting with a male or female could provide a wealth of data on how gender influences student perceptions of teaching effectiveness. Given the importance of the role student ratings play in hiring, retention, promotion, tenure, and salary deliberations in academic careers, this question warrants further attention as it is important to be aware of possible bias in student evaluations if they are to be used at all with respect to any academic considerations. For experimental purposes, the author’s constructed and online class where each instructors operate under two different gender identities. In this study, each instructor taught multiple sections of the same class using both a male identity and a female identity. The study examined student evaluations of teaching based on certain student and instructor characteristics in order to determine if and where male and female students might differ in their ratings of instructors based on instructor gender. Additionally, the authors examined if there are differences between undergraduate and graduate students' ratings with respect to the experimental criteria.Keywords: gender bias, ethics, student evaluations, student perceptions, online instruction
Procedia PDF Downloads 266340 Digital Survey to Detect Factors That Determine Successful Implementation of Cooperative Learning in Physical Education
Authors: Carolin Schulze
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Characterized by a positive interdependence of learners, cooperative learning (CL) is one possibility of successfully dealing with the increasing heterogeneity of students. Various positive effects of CL on the mental, physical and social health of students have already been documented. However, this structure is still rarely used in physical education (PE). Moreover, there is a lack of information about factors that determine the successful implementation of CL in PE. Therefore, the objective of the current study was to find out factors that determine the successful implementation of CL in PE using a digital questionnaire that was conducted from November to December 2022. In addition to socio-demographic data (age, gender, teaching experience, and education level), frequency of using CL, implementation strategies (theory-led, student-centred), and positive and negative effects of CL were measured. Furthermore, teachers were asked to rate the success of implementation on a 6-point rating scale (1-very successful to 6-not successful at all). For statistical analysis, multiple linear regression was performed, setting the success of implementation as the dependent variable. A total of 224 teachers (mean age=44.81±10.60 years; 58% male) took part in the current study. Overall, 39% of participants stated that they never use CL in their PE classes. Main reasons against the implementations of CL in PE were no time for preparation (74%) or for implementation (61%) and high heterogeneity of students (55%). When using CL, most of the reported difficulties are related to uncertainties about the correct procedure (54%) and the heterogeneous performance of students (54%). The most frequently mentioned positive effect was increased motivation of students (42%) followed by an improvement of psychological abilities (e.g. self-esteem, self-concept; 36%) and improved class cohesion (31%). Reported negative effects were unpredictability (29%), restlessness (24%), confusion (24%), and conflicts between students (17%). The successful use of CL is related to a theory-based preparation (e.g., heterogeneous formation of groups, use of rules and rituals) and a flexible implementation tailored to the needs and conditions of students (e.g., the possibility of individual work, omission of CL phases). Compared to teachers who solely implemented CL theory-led or student-adapted, teachers who switched from theory-led preparation to student-centred implementation of CL reported more successful implementation (t=5.312; p<.001). Neither frequency of using CL in PE nor the gender, age, the teaching experience, or the education level of the teacher showed a significant connection with the successful use of CL. Corresponding to the results of the current study, it is advisable that teachers gather enough knowledge about CL during their education and to point out the need to adapt the learning structure according to the diversity of their students. In order to analyse implementation strategies of teachers more deeply, qualitative methods and guided interviews with teachers are needed.Keywords: diversity, educational technology, physical education, teaching styles
Procedia PDF Downloads 81339 Comparisons of Depressive Symptoms and Cognitive Appraisals in Different Age Groups under Abusive Leadership
Authors: Shao-Ying Wang, Shin-I Shih, Chi-Cheng Wu
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Background: By following to the maturity theory about age, the manifestation of depression in different age groups under occupational stressors still remains unclear. Therefore, the aim of this study was to examine the depression within four main symptoms clusters: cognition, affect, physical complaints and interpersonal difficulty among the different age groups. Additionally, this study also used the stress appraisal theory, through the examination of challenge and hindrance appraisals, the effects of cognitive factors were expected to give therapeutic indication for the future treatment of depression under abusive leadership. Methods (Participants and Procedure): The data were collected in two waves from employees of local companies in Taiwan. The participants (58 males and 167 females) were native Chinese speakers, ranging in age from 20 to 59 years (M= 36.51). Up to 80% educational level of participants were above senior high. The married population was approximately at 43%. Measures; 1. Abusive Leadership: To measure abusive leadership, we used 15-item scale of abusive supervision which anchored on a 7-point Likert-type scale. (α= .96) 2. Depression: We used Taiwanese Depression Scale to measure the 4 clusters (cognition, affect, physical complaints and interpersonal difficulty) of symptoms. Participants responded for depression anchored on a 7-point Likert-type scale (α= .96). 3. Stress Appraisal Scale: To measure challenge and hindrance types of appraisal, participants responded to 33-item measure anchored on a 7-point Likert-type scale. (Challenge appraisal; α= .90; hindrance appraisal α= .87). Results: The results of correlation showed that there was a significant and negative correlation between abusive leadership and age (r = - .21, p < .01). Abusive leadership was positive correlated significantly with hindrance appraisal (r = .52, p < .01) and depression (r = .20, p < .01). The results also showed that hindrance appraisal was correlated to depression positively (r = .36, p < .01). A one-way ANOVA was conducted to compare the effect of lower/middle/order age groups on each cluster of depressive symptoms. The results showed that the effect of age groups on cognition was significant F (2, 157) =3.66, P < .05. Older age group (M=13.43 SD=6.84) reported less cognitive symptoms of depression than the middle (M=16.77 SD=7.49) and lower age (M=16.91 SD=6.97) groups. Besides, the effect of age groups on affect was also significant F (2,157)= 4.09 P < .05. Older age group (M=18.68 SD=8.98) reported less affective symptoms of depression than the middle (M=22.01 SD=7.96) and lower age (M=23.56 SD=7.67) groups. Moreover, the main effect of hindrance appraisal was found F (2, 157) =3.81, P < .05. Older age group (M=9.44 SD=2.89) reported fewer score on hindrance appraisals than the middle (M=11.06 SD=4.02) and lower age (M=9.62 SD=3.17) groups. To conclude, the severity of depression symptoms varies across different age groups. Maturity seems to be the protective factor to depression, accompanying with lower hindrance appraisals.Keywords: abusive leadership, affective commitment, depression symptoms, psychological well-being
Procedia PDF Downloads 203338 Safety of Mesenchymal Stem Cells Therapy: Potential Risk of Spontaneous Transformations
Authors: Katarzyna Drela, Miroslaw Wielgos, Mikolaj Wrobel, Barbara Lukomska
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Mesenchymal stem cells (MSCs) have a great potential in regenerative medicine. Since the initial number of isolated MSCs is limited, in vitro propagation is often required to reach sufficient numbers of cells for therapeutic applications. During long-term culture MSCs may undergo genetic or epigenetic alterations that subsequently increase the probability of spontaneous malignant transformation. Thus, factors that influence genomic stability of MSCs following long-term expansions need to be clarified before cultured MSCs are employed for clinical application. The aim of our study was to investigate the potential for spontaneous transformation of human neonatal cord blood (HUCB-MSCs) and adult bone marrow (BM-MSCs) derived MSCs. Materials and Methods: HUCB-MSCs and BM-MSCs were isolated by standard Ficoll gradient centrifugations method. Isolated cells were initially plated in high density 106 cells per cm2. After 48 h medium were changed and non-adherent cells were removed. The malignant transformation of MSCs in vitro was evaluated by morphological changes, proliferation rate, ability to enter cell senescence, the telomerase expression and chromosomal abnormality. Proliferation of MSCs was analyzed with WST-1 reduction method and population doubling time (PDT) was calculated at different culture stages. Then the expression pattern of genes characteristic for mesenchymal or epithelial cells, as well as transcriptions factors were examined by RT-PCR. Concomitantly, immunocytochemical analysis of gene-related proteins was employed. Results: Our studies showed that MSCs from all bone marrow isolations ultimately entered senescence and did not undergo spontaneous malignant transformation. However, HUCB-MSCs from one of the 15 donors displayed an increased proliferation rate, failed to enter senescence, and exhibited an altered cell morphology. In this sample we observed two different cell phenotypes: one mesenchymal-like exhibited spindle shaped morphology and express specific mesenchymal surface markers (CD73, CD90, CD105, CD166) with low proliferation rate, and the second one with round, densely package epithelial-like cells with significantly increased proliferation rate. The PDT of epithelial-like populations was around 1day and 100% of cells were positive for proliferation marker Ki-67. Moreover, HUCB-MSCs showed a positive expression of human telomerase reverse transcriptase (hTERT), cMYC and exhibit increased number of CFU during the long-term culture in vitro. Furthermore, karyotype analysis revealed chromosomal abnormalities including duplications. Conclusions: Our studies demonstrate that HUCB-MSCs are susceptible to spontaneous malignant transformation during long-term culture. Spontaneous malignant transformation process following in vitro culture has enormous effect on the biosafety issues of future cell-based therapies and regenerative medicine regimens.Keywords: mesenchymal stem cells, spontaneous, transformation, long-term culture
Procedia PDF Downloads 267337 Axillary Evaluation with Targeted Axillary Dissection Using Ultrasound-Visible Clips after Neoadjuvant Chemotherapy for Patients with Node-Positive Breast Cancer
Authors: Naomi Sakamoto, Eisuke Fukuma, Mika Nashimoto, Yoshitomo Koshida
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Background: Selective localization of the metastatic lymph node with clip and removal of clipped nodes with sentinel lymph node (SLN), known as targeted axillary dissection (TAD), reduced false-negative rates (FNR) of SLN biopsy (SLNB) after neoadjuvant chemotherapy (NAC). For the patients who achieved nodal pathologic complete response (pCR), accurate staging of axilla by TAD lead to omit axillary lymph node dissection (ALND), decreasing postoperative arm morbidity without a negative effect on overall survival. This study aimed to investigate the ultrasound (US) identification rate and success removal rate of two kinds of ultrasound-visible clips placed in metastatic lymph nodes during TAD procedure. Methods: This prospective study was conducted using patients with clinically T1-3, N1, 2, M0 breast cancer undergoing NAC followed by surgery. A US-visible clip was placed in the suspicious lymph node under US guidance before neoadjuvant chemotherapy. Before surgery, US examination was performed to evaluate the detection rate of clipped node. During the surgery, the clipped node was removed using several localization techniques, including hook-wire localization, dye-injection, or fluorescence technique, followed by a dual-technique SLNB and resection of palpable nodes if present. For the fluorescence technique, after injection of 0.1-0.2 mL of indocyanine green dye (ICG) into the clipped node, ICG fluorescent imaging was performed using the Photodynamic Eye infrared camera (Hamamatsu Photonics k. k., Shizuoka, Japan). For the dye injection method, 0.1-0.2 mL of pyoktanin blue dye was injected into the clipped node. Results: A total of 29 patients were enrolled. Hydromark™ breast biopsy site markers (Hydromark, T3 shape; Devicor Medical Japan, Tokyo, Japan) was used in 15patients, whereas a UltraCor™ Twirl™ breast marker (Twirl; C.R. Bard, Inc, NJ, USA) was placed in 14 patients. US identified the clipped node marked with the UltraCore Twirl in 100% (14/14) and with the Hydromark in 93.3% (14/15, p = ns). Success removal of clipped node marked with the UltraCore Twirl was achieved in 100% (14/14), whereas the node marked with the Hydromark was removed in 80% (12/15) (p = ns). Conclusions: The ultrasound identification rate differed between the two types of ultrasound-visible clips, which also affected the success removal rate of clipped nodes. Labelling the positive node with a US-highly-visible clip allowed successful TAD.Keywords: breast cancer, neoadjuvant chemotherapy, targeted axillary dissection, breast tissue marker, clip
Procedia PDF Downloads 66336 Characterization and Evaluation of the Dissolution Increase of Molecular Solid Dispersions of Efavirenz
Authors: Leslie Raphael de M. Ferraz, Salvana Priscylla M. Costa, Tarcyla de A. Gomes, Giovanna Christinne R. M. Schver, Cristóvão R. da Silva, Magaly Andreza M. de Lyra, Danilo Augusto F. Fontes, Larissa A. Rolim, Amanda Carla Q. M. Vieira, Miracy M. de Albuquerque, Pedro J. Rolim-Neto
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Efavirenz (EFV) is a drug used as first-line treatment of AIDS. However, it has poor aqueous solubility and wettability, presenting problems in the gastrointestinal tract absorption and bioavailability. One of the most promising strategies to improve the solubility is the use of solid dispersions (SD). Therefore, this study aimed to characterize SD EFZ with the polymers: PVP-K30, PVPVA 64 and SOLUPLUS in order to find an optimal formulation to compose a future pharmaceutical product for AIDS therapy. Initially, Physical Mixtures (PM) and SD with the polymers were obtained containing 10, 20, 50 and 80% of drug (w/w) by the solvent method. The best formulation obtained between the SD was selected by in vitro dissolution test. Finally, the drug-carrier system chosen, in all ratios obtained, were analyzed by the following techniques: Differential Scanning Calorimetry (DSC), polarization microscopy, Scanning Electron Microscopy (SEM) and spectrophotometry of absorption in the region of infrared (IR). From the dissolution profiles of EFV, PM and SD, the values of area Under The Curve (AUC) were calculated. The data showed that the AUC of all PM is greater than the isolated EFV, this result is derived from the hydrophilic properties of the polymers thus favoring a decrease in surface tension between the drug and the dissolution medium. In adittion, this ensures an increasing of wettability of the drug. In parallel, it was found that SD whom had higher AUC values, were those who have the greatest amount of polymer (with only 10% drug). As the amount of drug increases, it was noticed that these results either decrease or are statistically similar. The AUC values of the SD using the three different polymers, followed this decreasing order: SD PVPVA 64-EFV 10% > SD PVP-K30-EFV 10% > SD Soluplus®-EFV 10%. The DSC curves of SD’s did not show the characteristic endothermic event of drug melt process, suggesting that the EFV was converted to its amorphous state. The analysis of polarized light microscopy showed significant birefringence of the PM’s, but this was not observed in films of SD’s, thus suggesting the conversion of the drug from the crystalline to the amorphous state. In electron micrographs of all PM, independently of the percentage of the drug, the crystal structure of EFV was clearly detectable. Moreover, electron micrographs of the SD with the two polymers in different ratios investigated, we observed the presence of particles with irregular size and morphology, also occurring an extensive change in the appearance of the polymer, not being possible to differentiate the two components. IR spectra of PM corresponds to the overlapping of polymer and EFV bands indicating thereby that there is no interaction between them, unlike the spectra of all SD that showed complete disappearance of the band related to the axial deformation of the NH group of EFV. Therefore, this study was able to obtain a suitable formulation to overcome the solubility limitations of the EFV, since SD PVPVA 64-EFZ 10% was chosen as the best system in delay crystallization of the prototype, reaching higher levels of super saturation.Keywords: characterization, dissolution, Efavirenz, solid dispersions
Procedia PDF Downloads 631335 Method for Selecting and Prioritising Smart Services in Manufacturing Companies
Authors: Till Gramberg, Max Kellner, Erwin Gross
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This paper presents a comprehensive investigation into the topic of smart services and IIoT-Platforms, focusing on their selection and prioritization in manufacturing organizations. First, a literature review is conducted to provide a basic understanding of the current state of research in the area of smart services. Based on discussed and established definitions, a definition approach for this paper is developed. In addition, value propositions for smart services are identified based on the literature and expert interviews. Furthermore, the general requirements for the provision of smart services are presented. Subsequently, existing approaches for the selection and development of smart services are identified and described. In order to determine the requirements for the selection of smart services, expert opinions from successful companies that have already implemented smart services are collected through semi-structured interviews. Based on the results, criteria for the evaluation of existing methods are derived. The existing methods are then evaluated according to the identified criteria. Furthermore, a novel method for the selection of smart services in manufacturing companies is developed, taking into account the identified criteria and the existing approaches. The developed concept for the method is verified in expert interviews. The method includes a collection of relevant smart services identified in the literature. The actual relevance of the use cases in the industrial environment was validated in an online survey. The required data and sensors are assigned to the smart service use cases. The value proposition of the use cases is evaluated in an expert workshop using different indicators. Based on this, a comparison is made between the identified value proposition and the required data, leading to a prioritization process. The prioritization process follows an established procedure for evaluating technical decision-making processes. In addition to the technical requirements, the prioritization process includes other evaluation criteria such as the economic benefit, the conformity of the new service offering with the company strategy, or the customer retention enabled by the smart service. Finally, the method is applied and validated in an industrial environment. The results of these experiments are critically reflected upon and an outlook on future developments in the area of smart services is given. This research contributes to a deeper understanding of the selection and prioritization process as well as the technical considerations associated with smart service implementation in manufacturing organizations. The proposed method serves as a valuable guide for decision makers, helping them to effectively select the most appropriate smart services for their specific organizational needs.Keywords: smart services, IIoT, industrie 4.0, IIoT-platform, big data
Procedia PDF Downloads 88334 Microbial Biogeography of Greek Olive Varieties Assessed by Amplicon-Based Metagenomics Analysis
Authors: Lena Payati, Maria Kazou, Effie Tsakalidou
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Table olives are one of the most popular fermented vegetables worldwide, which along with olive oil, have a crucial role in the world economy. They are highly appreciated by the consumers for their characteristic taste and pleasant aromas, while several health and nutritional benefits have been reported as well. Until recently, microbial biogeography, i.e., the study of microbial diversity over time and space, has been mainly associated with wine. However, nowadays, the term 'terroir' has been extended to other crops and food products so as to link the geographical origin and environmental conditions to quality aspects of fermented foods. Taking the above into consideration, the present study focuses on the microbial fingerprinting of the most important olive varieties of Greece with the state-of-the-art amplicon-based metagenomics analysis. Towards this, in 2019, 61 samples from 38 different olive varieties were collected at the final stage of ripening from 13 well spread geographical regions in Greece. For the metagenomics analysis, total DNA was extracted from the olive samples, and the 16S rRNA gene and ITS DNA region were sequenced and analyzed using bioinformatics tools for the identification of bacterial and yeasts/fungal diversity, respectively. Furthermore, principal component analysis (PCA) was also performed for data clustering based on the average microbial composition of all samples from each region of origin. According to the composition, results obtained, when samples were analyzed separately, the majority of both bacteria (such as Pantoea, Enterobacter, Roserbergiella, and Pseudomonas) and yeasts/fungi (such as Aureobasidium, Debaromyces, Candida, and Cladosporium) genera identified were found in all 61 samples. Even though interesting differences were observed at the relative abundance level of the identified genera, the bacterial genus Pantoea and the yeast/fungi genus Aureobasidium were the dominant ones in 35 and 40 samples, respectively. Of note, olive samples collected from the same region had similar fingerprint (genera identified and relative abundance level) regardless of the variety, indicating a potential association between the relative abundance of certain taxa and the geographical region. When samples were grouped by region of origin, distinct bacterial profiles per region were observed, which was also evident from the PCA analysis. This was not the case for the yeast/fungi profiles since 10 out of the 13 regions were grouped together mainly due to the dominance of the genus Aureobasidium. A second cluster was formed for the islands Crete and Rhodes, both of which are located in the Southeast Aegean Sea. These two regions clustered together mainly due to the identification of the genus Toxicocladosporium in relatively high abundances. Finally, the Agrinio region was separated from the others as it showed a completely different microbial fingerprinting. However, due to the limited number of olive samples from some regions, a subsequent PCA analysis with more samples from these regions is expected to yield in a more clear clustering. The present study is part of a bigger project, the first of its kind in Greece, with the ultimate goal to analyze a larger set of olive samples of different varieties and from different regions in Greece in order to have a reliable olives’ microbial biogeography.Keywords: amplicon-based metagenomics analysis, bacteria, microbial biogeography, olive microbiota, yeasts/fungi
Procedia PDF Downloads 114333 Synthesis of MIPs towards Precursors and Intermediates of Illicit Drugs and Their following Application in Sensing Unit
Authors: K. Graniczkowska, N. Beloglazova, S. De Saeger
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The threat of synthetic drugs is one of the most significant current drug problems worldwide. The use of drugs of abuse has increased dramatically during the past three decades. Among others, Amphetamine-Type Stimulants (ATS) are globally the second most widely used drugs after cannabis, exceeding the use of cocaine and heroin. ATS are potent central nervous system (CNS) stimulants, capable of inducing euphoric static similar to cocaine. Recreational use of ATS is widespread, even though warnings of irreversible damage of the CNS were reported. ATS pose a big problem and their production contributes to the pollution of the environment by discharging big volumes of liquid waste to sewage system. Therefore, there is a demand to develop robust and sensitive sensors that can detect ATS and their intermediates in environmental water samples. A rapid and simple test is required. Analysis of environmental water samples (which sometimes can be a harsh environment) using antibody-based tests cannot be applied. Therefore, molecular imprinted polymers (MIPs), which are known as synthetic antibodies, have been chosen for that approach. MIPs are characterized with a high mechanical and thermal stability, show chemical resistance in a broad pH range and various organic or aqueous solvents. These properties make them the preferred type of receptors for application in the harsh conditions imposed by environmental samples. To the best of our knowledge, there are no existing MIPs-based sensors toward amphetamine and its intermediates. Also not many commercial MIPs for this application are available. Therefore, the aim of this study was to compare different techniques to obtain MIPs with high specificity towards ATS and characterize them for following use in a sensing unit. MIPs against amphetamine and its intermediates were synthesized using a few different techniques, such as electro-, thermo- and UV-initiated polymerization. Different monomers, cross linkers and initiators, in various ratios, were tested to obtain the best sensitivity and polymers properties. Subsequently, specificity and selectivity were compared with commercially available MIPs against amphetamine. Different linkers, such as lipoic acid, 3-mercaptopioponic acid and tyramine were examined, in combination with several immobilization techniques, to select the best procedure for attaching particles on sensor surface. Performed experiments allowed choosing an optimal method for the intended sensor application. Stability of MIPs in extreme conditions, such as highly acidic or basic was determined. Obtained results led to the conclusion about MIPs based sensor applicability in sewage system testing.Keywords: amphetamine type stimulants, environment, molecular imprinted polymers, MIPs, sensor
Procedia PDF Downloads 250332 Study of Interplanetary Transfer Trajectories via Vicinity of Libration Points
Authors: Zhe Xu, Jian Li, Lvping Li, Zezheng Dong
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This work is to study an optimized transfer strategy of connecting Earth and Mars via the vicinity of libration points, which have been playing an increasingly important role in trajectory designing on a deep space mission, and can be used as an effective alternative solution for Earth-Mars direct transfer mission in some unusual cases. The use of vicinity of libration points of the sun-planet body system is becoming potential gateways for future interplanetary transfer missions. By adding fuel to cargo spaceships located in spaceports, the interplanetary round-trip exploration shuttle mission of such a system facility can also be a reusable transportation system. In addition, in some cases, when the S/C cruising through invariant manifolds, it can also save a large amount of fuel. Therefore, it is necessary to make an effort on looking for efficient transfer strategies using variant manifold about libration points. It was found that Earth L1/L2 Halo/Lyapunov orbits and Mars L2/L1 Halo/Lyapunov orbits could be connected with reasonable fuel consumption and flight duration with appropriate design. In the paper, the halo hopping method and coplanar circular method are briefly introduced. The former used differential corrections to systematically generate low ΔV transfer trajectories between interplanetary manifolds, while the latter discussed escape and capture trajectories to and from Halo orbits by using impulsive maneuvers at periapsis of the manifolds about libration points. In the following, designs of transfer strategies of the two methods are shown here. A comparative performance analysis of interplanetary transfer strategies of the two methods is carried out accordingly. Comparison of strategies is based on two main criteria: the total fuel consumption required to perform the transfer and the time of flight, as mentioned above. The numeric results showed that the coplanar circular method procedure has certain advantages in cost or duration. Finally, optimized transfer strategy with engineering constraints is searched out and examined to be an effective alternative solution for a given direct transfer mission. This paper investigated main methods and gave out an optimized solution in interplanetary transfer via the vicinity of libration points. Although most of Earth-Mars mission planners prefer to build up a direct transfer strategy for the mission due to its advantage in relatively short time of flight, the strategies given in the paper could still be regard as effective alternative solutions since the advantages mentioned above and longer departure window than direct transfer.Keywords: circular restricted three-body problem, halo/Lyapunov orbit, invariant manifolds, libration points
Procedia PDF Downloads 244331 Seismic Response Control of Multi-Span Bridge Using Magnetorheological Dampers
Authors: B. Neethu, Diptesh Das
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The present study investigates the performance of a semi-active controller using magneto-rheological dampers (MR) for seismic response reduction of a multi-span bridge. The application of structural control to the structures during earthquake excitation involves numerous challenges such as proper formulation and selection of the control strategy, mathematical modeling of the system, uncertainty in system parameters and noisy measurements. These problems, however, need to be tackled in order to design and develop controllers which will efficiently perform in such complex systems. A control algorithm, which can accommodate un-certainty and imprecision compared to all the other algorithms mentioned so far, due to its inherent robustness and ability to cope with the parameter uncertainties and imprecisions, is the sliding mode algorithm. A sliding mode control algorithm is adopted in the present study due to its inherent stability and distinguished robustness to system parameter variation and external disturbances. In general a semi-active control scheme using an MR damper requires two nested controllers: (i) an overall system controller, which derives the control force required to be applied to the structure and (ii) an MR damper voltage controller which determines the voltage required to be supplied to the damper in order to generate the desired control force. In the present study a sliding mode algorithm is used to determine the desired optimal force. The function of the voltage controller is to command the damper to produce the desired force. The clipped optimal algorithm is used to find the command voltage supplied to the MR damper which is regulated by a semi active control law based on sliding mode algorithm. The main objective of the study is to propose a robust semi active control which can effectively control the responses of the bridge under real earthquake ground motions. Lumped mass model of the bridge is developed and time history analysis is carried out by solving the governing equations of motion in the state space form. The effectiveness of MR dampers is studied by analytical simulations by subjecting the bridge to real earthquake records. In this regard, it may also be noted that the performance of controllers depends, to a great extent, on the characteristics of the input ground motions. Therefore, in order to study the robustness of the controller in the present study, the performance of the controllers have been investigated for fourteen different earthquake ground motion records. The earthquakes are chosen in such a way that all possible characteristic variations can be accommodated. Out of these fourteen earthquakes, seven are near-field and seven are far-field. Also, these earthquakes are divided into different frequency contents, viz, low-frequency, medium-frequency, and high-frequency earthquakes. The responses of the controlled bridge are compared with the responses of the corresponding uncontrolled bridge (i.e., the bridge without any control devices). The results of the numerical study show that the sliding mode based semi-active control strategy can substantially reduce the seismic responses of the bridge showing a stable and robust performance for all the earthquakes.Keywords: bridge, semi active control, sliding mode control, MR damper
Procedia PDF Downloads 124330 Effect of Ease of Doing Business to Economic Growth among Selected Countries in Asia
Authors: Teodorica G. Ani
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Economic activity requires an encouraging regulatory environment and effective rules that are transparent and accessible to all. The World Bank has been publishing the annual Doing Business reports since 2004 to investigate the scope and manner of regulations that enhance business activity and those that constrain it. A streamlined business environment supporting the development of competitive small and medium enterprises (SMEs) may expand employment opportunities and improve the living conditions of low income households. Asia has emerged as one of the most attractive markets in the world. Economies in East Asia and the Pacific were among the most active in making it easier for local firms to do business. The study aimed to describe the ease of doing business and its effect to economic growth among selected economies in Asia for the year 2014. The study covered 29 economies in East Asia, Southeast Asia, South Asia and Middle Asia. Ease of doing business is measured by the Doing Business indicators (DBI) of the World Bank. The indicators cover ten aspects of the ease of doing business such as starting a business, dealing with construction permits, getting electricity, registering property, getting credit, protecting investors, paying taxes, trading across borders, enforcing contracts and resolving insolvency. In the study, Gross Domestic Product (GDP) was used as the proxy variable for economic growth. Descriptive research was the research design used. Graphical analysis was used to describe the income and doing business among selected economies. In addition, multiple regression was used to determine the effect of doing business to economic growth. The study presented the income among selected economies. The graph showed China has the highest income while Maldives produces the lowest and that observation were supported by gathered literatures. The study also presented the status of the ten indicators of doing business among selected economies. The graphs showed varying trends on how easy to start a business, deal with construction permits and to register property. Starting a business is easiest in Singapore followed by Hong Kong. The study found out that the variations in ease of doing business is explained by starting a business, dealing with construction permits and registering property. Moreover, an explanation of the regression result implies that a day increase in the average number of days it takes to complete a procedure will decrease the value of GDP in general. The research proposed inputs to policy which may increase the awareness of local government units of different economies on the simplification of the policies of the different components used in measuring doing business.Keywords: doing business, economic growth, gross domestic product, Asia
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